Experimental Biology and Medicine

In the mouse and rat an interstitial myocarditis, of which the cellular infiltration is in part eosinophilic, results from the intraperitoneal injection of neoprontosil and certain other drugs of the sulfonamide group. This myocarditis is histologically similar to that observed in the hearts of humans dying after the administration of these drugs.

Biotin-deficiency is brought about in the chick reared on a heated ration of low biotin content (O.1γ/g). This deficiency is produced in the absence of dietary egg white which is essential for the development of the avitaminosis in the rat. Deficiency symptoms are completely cured by administration of crystalline biotin methyl ester. The chick can be used in a quantitative biological assay of biotin.

1. A case history illustrating generalized muscular weakness as a toxic effect of digitalis is presented. 2. Four dogs given daily injections of a cardiac glycoside developed generalized muscular weakness. Four days after discontinuance of the drug, the animals were able to exercise without fatigue. 3. With the present trend towards increased digitalis dosage, it is possible that this syndrome may be encountered by other investigators.

Less than 10%, if any, of galacturonic acid, introduced as an isosmotic and isotonic solution, is absorbed from the canine small and large intestine and the human small intestine. Isosmotic galacturonic acid stimulates the secretion of fluid by the small intestine of unanesthetized human and canine subjects.

Eight women with regular menstrual periods and normal cyclic estrogen and progesterone production, as evidenced by the finding of typical secretory endometria premenstrually, were treated with androgens (methyl testosterone by mouth, testosterone propionate by injection, and testosterone and testosterone propionate by implantation) in order to determine the effect of the androgens upon excretion of SPG. The results indicate that doses of androgens which have been found, in previous studies, to be suppressive (i. e., to cause suppression of pituitary gonadotropic hormone excretion; inhibition of ovulation and menstruation), when administered early in the cycle, result in failure of SPG to appear in the urine during the current cycle and lead to suppression of the next expected menstrual period. In one patient (Case No. 6), 1175 mg of testosterone propionate, administered after the 9th day of the cycle, did not appear to appreciably affect the excretion of the pregnandiol complex during the current cycle.

These results are interpreted as indicating that if sufficient androgens are administered early in the cycle, before the pituitary gonadotropin has been secreted or had time to exert its effect on the ovary, progesterone production is suppressed, resulting in absence of pregnandiol from the urine during the current cycle. That absence of SPG from the urine is due to failure of progesterone formation and not to interference with the conversion of progesterone to the pregnandiol complex is proven by the absence of corpora lutea from the ovaries in the patients with no pregnandiol excretion.

A method for the preparation of a casein hydrolysate suitable for parenteral administration is described. Data are presented showing greater utilization and deaminization following the parenteral administration into fasting rabbits of an acid hydrolysate of casein to which 1-tryptophane and 1-cystine had been added, than following the administration of either glycine or partially racemized amino acids of an acid-base hydrolysate of casein.

The author is indebted to Arthur Nixon and Andrew Pangrace for valuable assistance.

Nicotinic acid enhances the growth of leptospira when added to Noguchi semi-solid medium in a final concentration of 0.01%. Cysteine hydrochloride in the same concentration has a similar effect, though not as marked as nicotinic acid. Glycine seems to have a reverse effect, and may even act to suppress the growth of the organisms.

1. The ability of rat liver slices to conjugate borneol with glucuronic acid in vitro is not impaired, even when marked cirrhosis and malignant degeneration of the liver are produced, by the feeding of dimethylaminoazobenzene. 2. The glucuronide excretion of rats fed dimethylaminoazobenzene is initially somewhat higher than in the control animals. However, after 100 days of dimethylaminoazobenzene feeding, the rate is less than 25 Jo of that seen initially.

From the foregoing results it seems clear that in the dog, removal of both kidneys does not prevent the immediate appearance of a pressor response to moderator nerve section. The reflex response to such a procedure is at least equal to that seen in normal dogs and if anything, seems to be heightened. Chloralose and ether were each used as anesthetic agents in both groups of experiments. It so happened that one of the most marked pressor responses occurred after the use of each kind of anesthetic agent in both the normal and nephrectomized group of dogs. In view of the slightly different initial blood pressure levels in the two groups, as well as the difficulty in ascertaining the exact depth of anesthesia in each experiment, close quantitative comparison of the pressor responses in the two groups is not justified. It would seem, however. that circulating pressor substances arising from the kidney (e. g., angiotonin) are not demonstrably important in the production of acute neurogenic hypertension.

Sulfadiazine increases the bactericidal action of normal blood when added in vitro or when exhibited orally. Comparative tests show that sulfathiazole is somewhat superior to sulfadiazine in its effect on Staphylococcus aureus.

It has been stated that estrogens are metabolized by the liver of the rat and completely inactivated. The best evidence for this is the excellent work of Heller 1 on tissue slices incubated with various estrogens. Methods of indirect attack in vivo have consisted in attempting to study effects of endogenous or exogenous estrogens in animals in whom the liver had been poisoned. 2 , 3 There have also been attempts to recover estrogens by hashing the whole animal after injection. 4 These have also led to the belief that estrogens are completely inactivated by the liver.

The present study of which this is a preliminary report was undertaken with the view of direct attack on this problem.

The estrogen in question was injected directly into the spleen in 0.05 cc of oil solution. The spleen was exposed through a mid-ventral incision and delivered to the outside; the site of entrance of the needle into the spleen was tied with an encircling silk ligature to prevent leakage of the oil. The injections were made into castrate females primed 14 days previously with 50 γ of estrone. Vaginal smears were taken with a moist, cotton tipped toothpick at 48, 60, and 72 hours after injection, and a fully cornified smear in any one or more of the three periods was considered as positive. These procedures were followed throughout except for a group of 10 animals on 100 γ of estrone, where it was necessary to use 0.1 cc of oil owing to the relative insolubility of the material.

The intrasplenic unit is defined as that amount of estrogen required to produce positive smears in 50% of at least 10 rats treated as described.

It is concluded that, contrary to the claims of other investigators, 1 oral administration of vitamin B₁ (thiamin hydrochloride) supplemented by force feeding is ineffective in preventing or in curing the paralysis in suckling rats attributable to an insufficiency of vitamin E.

No sodium pregnanediol glucuronidate was found in urine obtained from the bladders of slaughtered bulls and steers by the method of Venning. 3 The volumes of urine were judged sufficient for demonstration of this substance if it were present in the amount suggested by Marker's results for pregnanediol 3a, 20a from hydrolyzed bull's urine.

The administration of urinary estrogens increased the bactericidal property of the blood serum of adult male rabbits against E. typhi. This increase was greater shortly after the beginning of treatment. With prolonged treatment, the increase was less apparent but still significant up to the end of the experiment, that is to say, after 300 days of treatment. Whether this was a direct response to the estrogen administered or secondary to other changes in the body induced by hormonal action needs further investigation.

The purpose of the present investigation is to determine the effect in vitro of sulfanilamide, sulfapyridine and sulfathiazole on C. diphtheriae. Observations are also made as to how long it takes for effective action, and on the effect of sulfanilamide, sulfa-pyridine and sulfathiazole on various serological types of Mitis organisms. Nitti, Phillips and Bovet reported that sulfanilamide retards the development of diphtheria bacilli in culture. 1 In the same year, Rosa treated diphtheria carriers by applying the drug locally but failed in this attempt. 2

Methods and Materials. One to 1,000 dilutions of sulfanilamide and sulfapyridine were prepared from a 1% sulfanilamide solution and Soludagenan (1 g/3 cc) respectively, and standardized by means of the Klett-Summerson photo-electric colorimeter.∗ One to 1,000 dilution of sulfathiazole was prepared by heating aqueous solution containing a definite weight of the chemical. Final dilutions of 1:10,000 or 10 mg % were prepared by adding 0.2 cc of stock solution to 1.8 cc of liver digest broth, pH 7.6, containing 5% horse serum. All strains of C. diphtheriae were local strains isolated from the throats or noses of patients or carriers and were virulent to Chinese hamsters. One-tenth cc of 1:1,000 dilution of a 24-hour broth culture was used as the inoculum of the first 2 experiments, and a loopful of undiluted 24-hour cultures used in the third one. Survival of organisms was determined by growth on blood agar plates.

Experiment 1. The results of the experiment are summarized in Table I. It represents one of the 3 identical experiments. Under similar conditions, sulfathiazole seems to have exerted a very definite bactericidal action on representative strains of all the 3 cultural types of C. diphtheriae, while the other 2 were less effective on one Mitis strain than on strains of the other cultural types.

Testes of adult rabbits subjected to a series of exposures to X-rays aggregating 2,268 r (4.4 E.S.D.) over a period of 15 days showed complete atrophy of the germinal epithelium. The secretory function of the testes, as judged by the maintenance of the normal size of the penis and scrotal sacs, and by the normal psycho-sexual behavior of the animals, was not affected as long as 6 months following irradiation.

While the problem of immunity in relapsing fever of man and of laboratory animals has been extensively investigated, no definite conclusion has been reached owing to the contradictory findings. However, it is generally agreed that immunity following an attack of relapsing fever is of short duration but occasionally a long-lasting immunity may occur which has usually been attributed to the persistence of residual infection, notably in the brain. 1 , 2 , 3 , 4 In connection with our studies on the course and chemotherapy of experimental relapsing-fever infection by a California strain in Chinese hamsters, 6 opportunity arose for a careful examination of certain phases of immunity in this infection with special attention to its relation to residual brain-infection and to the influence of treatment in the development of immunity.

Twenty hamsters, both treated and untreated, which survived 20 to 43 days after spirochetes had disappeared from the peripheral blood, were used. These animals, 4 of which were treated with neo-arsphenamine,∗ 6 with trisodarsen,† and 4 untreated, were reinoculated with blood from one infected hamster, the amount inoculated being double that used in the original inoculation. The remaining 6 animals served as controls and were not reinfected. Following inoculation, blood smears were made daily on all animals during the period of observation.

Results. Among the neoarsphenamine-treated group, 2 showed complete and the other 2 partial resistance. In the latter cases spirochetes were found for only 1 or 2 days after a prolonged incubationary period of 5 to 8 days. Of the 6 treated with trisodarsen, 5 were completely protected, while the other showed partial immunity. Of the untreated animals, one showed partial immunity while the rest were completely resistant.

1. Progestin is not necessary for complete mammary development in cattle. 2. Estrogens will induce mammary development and copious milk secretion in cattle without injection of prolactin. 3. The turgidity of the udder may be used as an indicator of the secretory activity of the non-lactating gland. 4. The titer of estrogen determines its effect on the mammary gland. A low titer induces proliferation of the parenchyma and secretion of milk; a high titer suppresses lactation and brings on involution of the mammary gland.

Carbonic anhydrase is present in significant concentrations in the cortex of cat, dog and rat kidneys.

A method has been described to demonstrate that serum of patients convalescing from rheumatic fever and scarlet fever will protect mice against hemolytic streptococci.

A method is described for the assay of sodium-retaining substances in which desoxycorticosterone is employed as a standard. The sodium retention produced by the unknown is compared with that of desoxycorticosterone in a normal dog on a constant diet, over a 6-hour period.

Studies on gastric secretion in dogs provided with Heidenhain pouches definitely indicated that 929F, given subcutaneously, did not induce gastric secretion. However, following an injection of histamine in animals thus treated, the gastric secretion was markedly increased in volume and acidity over that which was obtained during control periods when only the histamine stimulus was employed.

These findings indicate that 929F, in the doses employed, neither destroys histamine nor antagonizes the action of histamine as a gastric secretory stimulant.

Since it is a generally accepted fact that salicyl therapy lowers the temperature and the leucocyte count of patients with acute rheumatic fever, it is our policy to rely on the sedimentation rate of erythrocytes as the best index of disease activity. Only when this returns to normal is the rheumatic infection considered quiescent. Prior to 1940, salicyl therapy was often continued for several weeks after the sedimentation rate became normal, but recently the drug has been discontinued as soon as a normal rate was obtained, assuming that rheumatic activity had then ceased. To our surprise the sedimentation rate in several cases became appreciably elevated during the first week after stopping medication. This was occasionally associated with an elevation of temperature, the return of symptoms, or both. In a few of the cases receiving second or third courses of the drug, the same phenomenon was observed.

The hospital course of 7 patients showing this type of reaction is presented in condensed form in Table I. Each child had acute rheumatic fever, and all except J.S. showed definite cardiac involvement. The rates were determined at approximately weekly intervals using the Rourke-Ernstene 1 technic. This method has been used for several years and has always given apparently consistent and reliable results in the rheumatic patients. Salicyl was administered by mouth in the form of acetyl salicylic acid combined with sodium bicarbonate. The celerity with which the “rise” occurred after discontinuing the drug suggests that this salicyl compound may have the ability to lower the sedimentation rate as well as the temperature and the leucocyte count in this disease.

In seeking an explanation of this reaction, the studies of Bendien, Newberg and Snapper 2 appeared to be pertinent.

Black pigment of the human lung, from the time of its earliest observation, was considered to be a collection of coal particles. Pearson in England first applied the term anthracosis in 1813. In Germany, on the contrary, this view was combatted and as late as 1855 Barthelmess discussed the condition as “pulmonary melanosis” and thought it was the result of hemorrhage and inflammation. By 1867 there was general agreement that the pigment was inhaled coal or soot. Klotz 1 has reviewed the subject. No modification of that view appeared until 1940. Then Woodruff 2 and Moerke 3 reverted to the old opinion that the pigment is endogenous. Their pigment was isolated by dissolving the tissue in concentrated hydrochloric acid at room temperature—a procedure known to produce abundant humin in the hydrolysis of protein at the boiling point.

In the present experiments, both clean (calf) and anthracotic lungs (human) were examined for pigment by solution of the tissue in the above solvent as well as in alkaline hypochlorite and by a combination of papain digestion followed by hypochlorite. Only these latter methods sufficed to reduce the clean lung tissue to a negligible residue.

Destruction of uncontaminated lung in concentrated hydrochloric acid left a residue which was soluble in neither organic solvents nor dilute alkali. It was dark red-brown in color, contained 8-10% N in different preparations and 1-1.2% ash. The material of Moerke contained 4-5% N and presumably was a mixture of the above product with anthracotic pigment. As there was no black pigment to be seen in the microscopic examination of the calf lung, the residue is obviously an artefact resulting from the process of digestion of the tissue, and the hydrochloric acid method is not satisfactory for the isolation of the pigment of anthracosis.

Although mannitol hexanitrate † has been used for many years for the treatment of essential hypertension and as a prophylactic against anginal attacks, few pharmacological studies are available in the literature. This paper is the first of a series designed to test this drug clinically and experimentally.

Table I shows that the 24-hour toxicity is very low when tested on 20 g mice. In another experiment, a solution of the material in triethylene glycol was given by stomach tube to 6 male rats weighing about 100 g. None of them developed any symptoms although the dosage was 1.25 g per kilogram.

In a study of chronic toxicity, 12 female rats weighing 60 g were given orally 11 mg per day of mannitol hexanitrate mixed in their diet of Purina fox chow. In addition, 6 male rats weighing 110 g received 8.5 mg in a corn oil solution daily from a medicine dropper. Nine stock animals served as controls. After 24 weeks there was no apparent effect of the drug on the rate of growth, general appearance of the rats or food intake. At autopsy they showed no gross pathological changes. Microscopic sections were made of the following tissues from 12 experimental and 5 control rats: liver, heart, spleen, kidney, and brain. These all appeared normal when stained by the H. and E. method except for moderate splenic congestion. Sections of testis and lung from four experimental rats showed no abnormalities.

Clinically it has been observed that the depressant effect of mannitol hexanitrate is more prolonged than that of other nitrate esters, e. g., glyceryl trinitrate and erythrol tetranitrate. 1 Yet the action of these compounds when injected intravenously into anesthetized cats was shown to be evanescent and similar in the blood pressure lowering, confirming the work of Herrman, et al. 2 The prolonged action of mannitol hexanitrate may depend on slowness of absorption.

The action of radiant energy in inducing gene mutations and various types of chromosomal alterations has been known for several years. 1 , 2 The alterations produced have involved changes in parts of chromosomes, whole chromosomes and apparently in the composition of individual genes. In Muller's classic report 1 on the artificial production by X-rays of alterations in the hereditary material of Drosophila melanogaster, evidence was presented, through breeding experiments, of the occurrence of dominant lethals. These are lethals whose presence in single dose can cause the death at various stages of development of the zygotes which contain them and thus are never transmitted to succeeding generations. Such dominant lethal genetic changes may be induced by X-rays in germ cells and then contributed to the zygote by one of the gametic nuclei. As yet, however, little is known of how the inviable nuclear alterations act to modify development. It is the purpose of this report to deal with certain aspects of this question.

The random effects of the radiations on the chromosomes of Drosophila have been reported elsewhere. 3 It was observed that the meiotic and mitotic divisions can become drastically disordered following treatment of the germ cells with X-rays. The achromatic figures as well as the chromosomes proper are frequently aberrant. In the zygotic mitoses chromosome fragmentation and elimination, asymmetrical divisions, multipolar divisions of the tri-polar and quadripolar types and pycnotic, clumped chromosomal complexes with occasional chromatic bridges were noted and described. These induced abnormalities were considered to be directly responsible for the greatly increased percentage of mortality among the offspring, since the frequency of organisms showing such mitotic abnormalities was found to be about equal to the frequency of zygotic lethals.

Sheep antigonadotropic rabbit serum, aspecific in nature, although effective in inhibiting the gonadotropic action of extracts of mammalian tissues and fluids did not prevent the typical effect of gonadotropic extracts made from chicken hypophyses. Chicken antigonadotropic rabbit serum, while inhibiting the gonadotropic action of chicken pituitary glands, was ineffective against gonadotropic extracts of sheep pituitary glands. The possible relationship of these experiments are discussed in regard to the nature of the antihormone mechanism.

Eighteen doses of 0.25, 1.0, 4.0 and 8.0 I.U. of crystalline progesterone were given, simultaneously with 120 I.U. of estrone, to immature male rabbits during a period of 4 weeks. Of these 4 levels of progesterone, the 1.0 I.U. dose synergized best although the prolactational proliferation induced was not maximal. The 4.0 and 8.0 I.U. doses of progesterone were apparently inhibiting as shown by the relatively poor mammary growth obtained.

Six groups of immature male rabbits were injected 5 days weekly for 5 weeks with 30, 60, 120, 240, 480, and 960 LU. of estrone respectively. The best mammary duct growth occurred in the animals receiving 120 LU. The 30 and 60 LU. animals showed slightly less extensive duct systems, and the higher levels caused cystic changes in the main ducts.

The same 6 levels of estrone were injected into 6 other groups of male rabbits along with 1 I.U. of progesterone dairy for a similar period. In every case, lobular growth of the mammary glands occurred and no tendency toward cyst formation was noticed even in the animals receiving the highest level of estrone. The mammary glands of the animals receiving the 2 lowest levels of estrone, plus progesterone had not developed as extensively as the others, but showed good lobule formation on a relatively shorter duct system. The best prolactational proliferation was observed in the groups receiving 1 I.U. of progesterone plus 240 and 960 I.U. of estrone respectively. Only the presence of incomplete lobules at the periphery of these glands made possible their differentiation from glands taken from rabbits in their second to third week of pregnancy—a period when prolactational proliferation is usually maximal.

Trypanosoma equiperdum can be cultivated in the developing chick egg by inoculation of the infected material into the yolk sac of the egg. An inoculum of 2 million trypanosomes per egg gave satisfactory results. In 93% of infected eggs microscopically visible infection occurred, or infection could be demonstrated by mouse passage. When trypanosomes could not be found microscopically in the egg, mice inoculated with the egg specimen usually became infected. Sometimes it took 14 to 35 days to have such mice die with T. equiperdum infection. Trypanosomes which did not infect the embryos seemed to have been destroyed or retained in the yolk sac. Death of infected embryos was accompanied with hemorrhages in the brain, liver, and heart. Inocula of 500,000 and one million trypanosomes caused infection in the egg. With inocula of 150,000 or less organisms satisfactory results were not obtained. Repeated passages in the egg do not change the virulence of T. equiperdum. To maintain strains in eggs it is necessary to inoculate a sufficient dose, i. e., 2 million organisms, to use several eggs, and to transfer once a week. The advantages of the above method are: 1. The injection into the yolk sac is a simpler method than injection on the chorio-allantoic membrane. 2. By injection into the allantoic cavity the embryo is killed in (some) 5 days and frequent transfers are necessary. The injection into the yolk sac retards the process of infection in the embryo.

To sum up, the Shwartzman phenomenon of local tissue reactivity was successfully produced in the heart and blood vessels by the use of “agar washings” filtrates of meningococcus. The hemorrhagic and necrotizing feature of the reaction together with altered vascular response at the sites of preparation were consistent findings.

Koinaroff 1 reported that carnosine, B-alanyl-1-histidine, produced a marked increase in the tonus of isolated rabbit intestine. McClintock and Hines 2 confirmed this observation and also noted that carnosine caused a similar increase in tonus and rhythmical contractions of the isolated guinea pig uterus. Contrary to this view is the work of McClosky, et al., 3 who were unable to substantiate the reported oxytocic effect of carnosine on uterine strips.

In the light of the somewhat conflicting work on uterine strips, we thought it would be worthwhile to reinvestigate the smooth muscle action of carnosine.∗ In the present work, isolated monkey† intestine was used. Oxygenated Tyrode's solution served as a physiological bath for these experiments. The temperature was kept at 37.5°C. Forty-eight experiments using various doses of carnosine were performed. Fig. 1 illustrates the typical effect as noted with 1.5 mg of this drug in a 100 cc bath.

For a long time we have been interested in the fact that morphine causes a relaxation of the isolated intestine in various animals, but markedly stimulates the tone of the intact intestine. While many workers, Dreyer, 4 Gruber, et al., 5 and others have reported a stimulating effect of morphine on isolated intestine, we have never consistently obtained such results. Rather, it has been our belief that in isolated tissue some necessary substance was lacking which prevented morphine from giving a typical response such as is seen in the intact animal. To test this hypothesis, 25 experiments were done on the isolated monkey intestine using morphine alone. Fig. 2 exemplifies the usual response; i. e., relaxation. When carnosine was given previously, however, a large dose of morphine did not cause relaxation (Fig. 3).

The absorption of calcium occurs chiefly from the upper part of the small intestine, the reaction of whose contents has been shown 1 normally to be acid. Irving and Ferguson 2 found the absorption of calcium to be facilitated when solutions of calcium chloride, deposited directly in the intestine of dogs, were buffered so as to maintain an acid reaction. There is a direct relationship between pH of the intestinal contents and gastric free acidity 3 and with advancing age there is a reduction in gastric acidity of both sexes. 4 Clinical experience 5 indicates that periclasia, one feature of which is alveolar bone resorption, is a condition which rarely occurs before age 20 but increases markedly in incidence after age 30. The coincidence of approximately equal age distributions of cases of physiological hypochlorhydria, periclasia and senile osteoporosis suggests that some cases of alveolar bone resorption are due to deficient calcium absorption consequent upon the secretion of an amount of hydrochloric acid by the stomach insufficient to maintain the normal acidity of the intestinal contents.

Seventy-nine individuals were subjected to gastric analyses, using 50 cc of 7% alcohol as the test meal. The method of Bloomfield and Keefer 6 was used for the gastric analyses, according to which, the entire stomach contents were aspirated and all of the contents returned to the stomach except for a 10 cc sample. This procedure was repeated each 10 minutes for one hour or until the stomach was empty. The samples were separately titrated and the results calculated so as to express the average contents of free and total acidity in terms of milliequivalents of hydrochloric acid per liter.

Anolis lizards which normally exhibit a different color response to day (brown) and night (green) were subjected to continuous light or darkness over a period from 6 to 18 days. Under the former condition a weak, but under the latter a very marked and precise diurnal color rhythm was exhibited for as long as 18 days. Hypophysectomized animals remained permanently green.

On the medium described above we have been able to cultivate Sp. gallinarum without difficulty. The cultures grow best at 37°C, but growth occurs also at 30°C and at 39°C; at 30°C growth is slower but the viability better than at 37°C, at 39°C the reverse is the case. The cultures reach optimum growth density in 4 to 5 days according to the size of the inoculum. If transferred to the ice box at this point they remain active for 10 days to 2 weeks. Transplants have been made as late as the 15th day of culture. One strain has been carried through 19 generations during a period of 150 days. The 18th subculture of this strain was still fully virulent for chickens and caused fatal infections.

(1) Sulfanilamide in high concentration (1000 mg %) exerts bacteriostatic activity toward small numbers of M. lysodeikticus. (2) Sulfanilamide in concentrations up to 1000 mg % and sulfapyridine and sulfathiazol in concentrations up to 100 mg °/c do not interfere with the lytic activity of lysozyme (egg white). (3) The combined use of lysozyme (egg white) and sulfamido compounds (sulfanilamide and sulfapyridine) exerts somewhat greater bactericidal effects upon M. lysodeikticus than either agent alone.

The method here presented appears satisfactory for -chemotherapeutic investigation. The beneficial therapeutic effect of both sulfanilamide and sulfapyridine on hemolytic streptococcal infection in white mice and hamsters is presented. Sulfapyridine is definitely superior to sulfanilamide in that it is less toxic. A very large dose of sulfapyridine can be given at one time to sterilize the infection without producing any toxic symptoms. These experiments also indicated the prompt penetration of the drug into the brain tissue.

Porphyrin incrustations on nose and fur, the most conspicuous symptom of pantothenic acid deficiency in albino rats, has been induced by partial dehydration of normal rats. This indicates that pantothenic acid may be involved in the regulation of water metabolism.

Recent work by one of the authors (Morgan) 1 , 2 demonstrated: that an experimental leucopenia could be produced in rabbits by the intravenous injection of a protein-free antigen derived from Eberthella typhosa. Because of this property of the antigen it was desired to determine whether the material would exert a positive or negative chemotaxis towards polymorphonuclear leucocytes.

The technic employed in these experiments was that of Chambers, and Grand. 3 It utilizes a small capillary tube filled with the material to be tested and one end of this tube is sealed with beeswax. This capillary is embedded in a drop of normal guinea pig plasma with its open end near a small fragment of normal adult guinea pig spleen. (The plasma was prepared with 1:1000 solution of heparin.)

After a few hours' incubation at 37°C the leucocytes begin to migrate from the fragment of spleen, and then, depending upon the properties of the material in the capillary tube which lies at right angles to their path, they either turn into the tube or avoid its open end.

The substances tested were (1) cells of Staphylococcus albus to serve as a control and (2) E. typhosa. Each of these was washed 3 times and suspended in Ringer's solution. The third was an antigenic extract of E. typhosa cultured in a synthetic medium and prepared as described by Morgan. 1 , 2

Twelve or more satisfactory preparations were made with each material and observed at intervals after 3 to 24 hours' incubation. The results of these tests, in brief, were as follows:

(a) With Staph. albus, which served as a control, the migration of the leucocytes from the splenic fragment was very pronounced, especially to the area about the point of the capillary tube.

In 9 of 10 human individuals, natural infection with virus of influenza, Type A, was followed by the development of, or a sharp increase in, the capacity of their nasal secretions to inactivate the virus. Although not numerically parallel, increases in neutralizing antibodies of the blood were also observed. These results add further support to the earlier conclusion that virus-inactivating substance in nasal secretions possesses the characteristics of antibody.

Para-aminobenzoic acid has anti-gray-hair activity in the nutritional achromotrichia of the mouse. It is a dietary factor necessary for the demonstration of the anti-alopecia effect of inositol.

When the hair is removed from the backs of underfed rats it does not grow externally for long periods. Upon adrenalectomy of such underfed rats, the hair grows on their backs in 8 or 9 days. Histological sections show no increased activity of the thyroid in such adrenalectomized animals. When underfed individuals are thyroidectomized one to 21 days previous to adrenalectomy, the hair, likewise, grows in 8 or 9 days after removal of the adrenals. There is, therefore, no evidence that the thyroid is responsible in any way for the rapid growth of hair in the rat following adrenalectomy.

Growth rates of E. coli were measured in the presence of sulfanilamide and p-amino benzoic acid. Mathematical analyses of the data indicate that the sulfanilamide inhibition is of the competitive type.

The pathogenesis of erythroblastosis fetalis has been ascribed to the isoimmunization of the mother by the Rh, or, more rarely, by other factors in the blood of the fetus. 1 , 2 According to this concept maternal agglutinins produced in response to this stimulus after passing the placenta, act on the susceptible blood of the fetus, and thus produce the various syndromes known as erythroblastosis fetalis. This theory does not differ in principle from the older concept of “heterospecific pregnancy” 3 based on the 4 blood groups. Thus, if the property A or B in the fetus is not present in the mother, the maternal agglutinin by its action on the fetal blood was thought to induce icturus gravis, (one of the manifestations of erythroblastosis fetalis). 4 Recently it was shown by Jonsson, 5 and confirmed by Levine, 6 that in the example cited the mother's normal agglutinins may be specifically increased in titer as a result of isoimmunization.

Nevertheless, the theory of heterospecific pregnancy was abandoned because of lack of evidence. 7 Furthermore, the demonstration that the factors A and B are present, also, in tissue cells and body fluids indicate that maternal isoantibodies are specifically inactivated after passing the placenta. However, this wide distribution of the A and B blood factors applies only to about 80% of individuals (secretors) and in the remainder (non-secretors) the A and B substances are presumably limited to red blood cells. 8 , 9 , 10

These facts suggested experiments to determine whether the Rh factor is also present in tissue cells or in body fluids. The tests were carried out with saliva because of its high concentration of the A and B substances.

Much interest has been aroused during the past year over the prospect of developing therapeutic agents that have antibacterial activity in the bowel. 1 , 2 , 3 A study covering 20 sulfonamides has unearthed a compound of considerable promise.

Succinyl sulfathiazole.∗ COOH . CH₂ . CH₂. CO . NH . C₆H₄ .-SO₂. NH . C₃H₂NS, has been shown to have little toxicity when administered to dogs orally at 4-hour intervals day and night. A dosage of one gram per kilo daily given in 6 equal doses results in a fecal drug content of from 5 to 10%. Under this regimen approximately 5% of the ingested drug is excreted in the urine, and the concentration of the drug in the blood will average 1.5 mg % of sulfathiazole and 2.0 mg % of succinyl sulfathiazole. The sulfathiazole is formed by the hydrolysis of a small portion of the conjugated compound by the animal tissues and by the bacteria in the bowel. Crystals of the drug do not appear in the urine.

The antibacterial action of succinyl sulfathiazole in the bowel as measured by the effect on the coliform organisms is presented graphically. The drug given in therapeutic doses profoundly alters the feces. They become semifluid and practically odorless.

No toxic manifestations have been observed. The animals gain weight and show no gross or microscopic evidence of tissue damage after receiving one gram per kilo of the compound daily in 6 doses for 5 weeks. During this entire period the number of B. coli per gram of wet stool averaged less than 100 organisms as compared to an average normal flora of 10,000,000.

Succinyl sulfathiazole has been administered to 40 human beings with various organic lesions and acute intestinal infections without the production of toxic reactions.

Studies of the tortoise heart in situ were made with a view to determining the extent to which ventricular filling is due to auricular systole. From observation it was obvious that such an effect existed, although it was difficult to show by means of a kymograph and lever system.

The cinematographic method, originally employed by Takeuchi 1 and Strughold 2 and lately Gray and Steggerda, 3 was used to record size changes and resulted in a clear picture, free from artifacts of inertia and overthrow common to mechanical systems. Pictures were taken at 8 per second and various diameters of the ventricle and auricle in each picture were measured under a binocular so that any change in diameter could be plotted graphically and used for further study.

In a typical curve from a slowly beating heart there is shown a definite increase in ventricular size just prior to systole. In all cases this coincides with the contraction of the auricles as indicated by the curve of auricular diameter. To examine the possibility that this auricular effect might be exaggerated by the absence of the restraining influence of the pericardium, experiments were done in which the beating heart was photographed through the pericardium. The measurements showed no difference between these hearts and those in which the pericardium had previously been removed. To further test the validity of this auricular effect on ventricular filling, the auricles were ligated in such a manner as to allow a clear passage for the blood from the sinus venosus to the ventricle, but at the same time preventing blood from entering the fundus of the auricles. By this operation, the mechanical effect of the auricular systole was abolished without impeding the path of either the blood or the excitation wave.

1. Monkey's milk tends toward that of the human in composition and differs from cow's milk in having a lower percentage of protein and ash and a higher percentage of milk sugar. 2. A modification of cow's milk for infant monkey (M. mulatta) feeding is described.

Aycock 1 has reported that castrated immature female monkeys given estrogenic hormone intramuscularly showed a higher level of resistance to intranasal inoculation with poliomyelitis virus than untreated castrates. His studies apparently were prompted in part by endocrinological observations showing that nasal mucosal changes are associated with the changes induced in the vaginal epithelium by estrogenic hormone under experimental conditions. Prominent among the observed genital responses is a thinning of the vaginal epithelium following castration and its restoration to normal with the administration of estrogenic hormone. However, so far as we are aware the nasal changes reported deal only with vascular responses in the region of the inferior and middle turbinates. 2 Possible changes in the olfactory portion of the nasal mucosa apparently have thus far not been considered.

Inasmuch as it has been established that in monkeys inoculated with poliomyelitis virus by the intranasal route the portal of entry is through the olfactory portion of the nasal mucosa, the results obtained by Aycock suggested the desirability of an experiment in which estrogen would be brought into direct contact with the olfactory mucosa for a number of days, immediately following which some of the animals would be tested for resistance to virus by the intranasal route and the olfactory mucosae of others would be examined histologically for possible anatomic responses.

Fifteen uncastrated female Macacus rhesus monkeys were given theelin in oil (10,000 International Units per cc solution†) by intranasal instillation, daily, as indicated in Table I. The instillations were made while the animals were under deep ether anesthesia and held in the fully inverted position in a special animal holder. They were made with a Luer syringe, to which was attached a 1-inch needle with a blunt point.

1. Sulfanilamide by oral administration in dosage of 0.1 g per kilo of weight, twice daily for 10 to 14 doses, had no appreciable effect upon the evolution and clinical course of experimental vaccinia of rabbits. 2. Under the circumstances it is unlikely that sulfanilamide has any effect upon the virus of smallpox, although its administration may be helpful in the treatment of smallpox and generalized vaccinia by reducing secondary staphylococcus or streptococcus infections of the vesicles.

During a period of 30 days' continuous cultivation of the Melbourne strain of influenza A virus in roller tubes, the respective titers of virus in the chick embryo tissue and fluid components after initial increases remained almost constant, provided the fluid contained serum and embryonic extract. When Tyrode solution or physiological saline was substituted, the amount of virus declined gradually after one week. The virus grew well in cultures of various organs from 14-day chick embryos except in the case of brain, heart and skeletal muscle.

Virus was not recovered after hatching from chicks infected as embryos with the Melbourne strain of influenza A virus. This virus survived and increased in cultures of 18- or 20-day embryo lung and lung tissue from 2-day-old chicks at 37° C, but not in cultures of embryo or chick lung at 41°C. Virus was not recovered from embryos inoculated by the chorio-allantoic route and kept at 41°C. Virus was demonstrated in the lungs of 1-day-old chicks at 19 but not at 48 hours after inoculation in the nares. No neutralizing antibodies for the virus were detected in sera of chicks following such inoculation nor in the sera of normal chicks or adult chickens.

Tyrothricin in small amounts is bactericidal against L. acidophilus in vitro. Tyrothricin has no effect on the same organism when it is administered by mouth to animals harboring this bacillus even when 160 times the in vitro killing dose is given. In the amounts used in these experiments tyrothricin was not found to produce lesions in the gastro-intestinal tract.

Investigations on the effect of X-rays on cells cultivated in vitro have been limited with few exceptions to an analysis of irradiation effects on the outgrowth and mitotic activity of cell colonies. 1 Our knowledge of the radiosensitivity of other aspects of cell activity is slight. We considered it justified, therefore, to undertake comparative studies in cell cultures on the sensitivity to irradiation of a variety of cell functions. The following is an account of experiments on the effect of X-rays on muscular contraction and ciliary movement.

Few attempts have been made to influence the kinetic activity of cells and tissues in vitro by means of X-rays. (Prime, 2 Gassul, 3 Haberlandt and Sanders, 4 Heeren, 5 Heine, 6 Scott. 7 ) In all these experiments no definite inhibiting effect was obtained owing to the small doses employed.

In our experiments we used an X-ray tube which was operated at a tension of ca 35 KV and a current of 30mA with a copper anti-cathode. The window was aluminium foil 30μ in thickness. Absorption analysis showed that the rays which penetrated through the window and the 0.03 mm thick mica coverglass of the culture were mainly copper-K-rays. The X-ray intensity was about 95,000 r/min at the distance of the irradiated subject.

The following experiments were carried out:

1. Effect of X-rays on the contraction of heart muscle. Fragments of myocardium of 7-day-old embryos in hanging drop cultures were used. Irradiation was carried out 2-4 hours after ex-plantation and its effect was observed about 10 minutes after completion of irradiation. A total of 92 heart muscle cultures were irradiated.

To obtain complete and immediate cessation of heart muscle contraction in culture it is necessary to use doses of 500-700,000 r.

The disappearance of radioactive phosphorus (P³²) from the heart blood of the horseshoe crab Limulus polyphemus, has been followed in 10 individuals, weighing from 94 to 245 g.

From 0.1 to 0.2 ml of 0.001 molar Na₂HPO₄ solution was injected into the heart at the thoracic-abdominal junction. The amounts of radioactive phosphorus in the solutions and in the samples of blood withdrawn from the heart at frequent intervals following injection were measured with a Geiger-Müller counter, and were expressed as counts per minute per milliliter of solution or per milligram of dried blood. All counts were corrected for background and for decay. The amounts injected were calculated to give equal doses of radioactive phosphorus per gram of body weight, the average dose bearing 3.5 × 10⁵ counts per minute.

In every one of the 10 experiments, the logarithm of the concentration of radioactive phosphorus left in the blood was inversely proportional to time, the slope of the plot relating the two from zero time to 1 hour varying from −0.91 to −3.06. At the beginning of the experiment the average number of counts per milligram of dried blood was 83, and at the end of 1 hour 97.6% of the radioactive phosphorus had disappeared from the blood. A few experiments with the lobster, Homarus americanus, gave essentially the same results except that the rate of disappearance was much slower.

These preliminary tests indicate that radioactive phosphorus will be useful in studying various problems in the physiology and biochemistry of the blood and tissues of Limulus and other invertebrates, just as it has been in the vertebrates. Several such problems are now being studied.

The intravenous injection of trypsin in doses of 1 to 2 mg per kilo in dogs, or 3 to 7 mg per kilo in rabbits produces a varying degree of incoagulability of the blood. As the addition of similar concentrations of trypsin to blood in vitro does not produce this incoagulability, the latter appears to be an indirect effect. The addition of suitable amounts of protamine restores the coagulability to normal, indicating that the coagulation defect is due to heparin, presumably liberated in vivo from various tissues such as the liver.

1. Radiophosphorus lowers the absolute numbers of red cells, lymphocytes, and granulocytes in monkeys. 2. The degree of effect is about the same in lymphocytes and granulocytes, red cells being less affected. 3. Monkeys tolerated dosages of .76 and .71 millicuries of radiophosphorus per pound of body weight, 1.04 millicuries per pound being fatal. 4. The tolerance levels of radiophosphorus are about 10 times that usually used therapeutically.

1. Deafferentation of a cat's forelimb does not lower the skin temperature of the footpad which may remain similar to the contralateral normally innervated one or may be warmer. 2. Deafferentation of a hindlimb may not affect the pad temperature, or it may be lowered or raised. 3. Any differences present in the fore-limbs or in the hindlimbs disappear after bilateral sympathectomy. 4. Section of the L₆-L₇ and S₁-S₂ ventral roots of a cat may not significantly affect the pad temperatures.

Preparations of mixtures of TMV and TNV were obtained from plants having both diseases. These viruses were then separated by removal of TMV by isoelectric precipitation and by means of absorption with rabbit antiserum to TMV. The separation was followed by means of the analytical ultracentrifuge, the Tiselius electrophoresis apparatus and the biological activities of the preparations.

Because hemophilia occurs only in males and is transmitted directly only by females, an assay of the urinary estrogenic hormone was undertaken.

The technic used was identical with that of Dr. Petersen of this institution in order that we might compare the results of our normal control group with his.

White female rats 2 months of age were used. Vaginal smears were made every 12 hours for 3 weeks to ascertain that estrous cycles were normal. Then a laparotomy was performed on each rat under ether anesthesia, the ovaries, broad ligaments and upper part of the cornua of the uterus being removed. The rats were then allowed 10 days to recover from the operation, following which vaginal smears were made at 12-hour intervals for 3 weeks to determine whether the estrous cycles had ceased.

One liter of urine from untreated hemophilic patients was used in each series of experiments. The urine, rendered acid to congo red, was extracted 3 times with benzene in a reflux condenser and evaporated to a syrup. Corn oil was then added and the remainder of the benzene evaporated. This leaves the hormone in the corn oil.

The rats were then divided into groups of 4. Three injections of urine extract of 1/6 cc each were made at 4-hour intervals into each of the 4 rats. Vaginal smears were made at 6-hour intervals for at least 48 hours or until activity ceased. If estrus was induced in 3 out of 4 rats, the test was considered positive.

The number of estrous cycles and the total hours of estrus were determined for the normal and hemophilic groups.

The urine of the first 5 hemophiliacs induced no estrual cycles. These results were recorded in a preliminary report in the J. Am. Med. Assn., Vol. 97, page 244.

1. The RBC and hemoglobin content of normal rats show higher values than those of normal females. 2. Following castration, the RBC and hemoglobin contents of the males drop, while those in the females rise. 3. Injections of estradiol into castrated females, and testosterone into castrated males produce, respectively, a drop and rise in RBC and hemoglobin. 4. Bone marrow studies indicate that androgens stimulate and estrogens inhibit erythro-cytopoiesis. 5. Additional support is thus given to the sex hormone explanation of the normal sex difference in RBC reported for many species of animals.

A new strain of the virus of influenza B was isolated from the throat washing of a case of influenza during an epidemic in California in January, 1940. The difficulties of isolating this virus by the usual methods of passage in ferrets and mice are noted. The new strain was not identical in antigenic composition with the Lee strain isolated by Francis, but was closely related to it.

The difficulty of isolating certain strains of influenza virus, especially influenza B, by ferret inoculation has led to a search for more susceptible animals. This paper will report the results of preliminary experiments with 2 species of kangaroo rat (Dipodomys deserti deserti and Dipodomys merriami simiolus) which were trapped in Southern California and Arizona. Most of the results to be reported were obtained with Dipodomys merriami simiolus which appeared to be slightly more susceptible than the other species.

Results with Influenza A Virus. Eight kangaroo rats were inoculated intranasally under ether anesthesia with 10% lung suspension-of the 352nd mouse passage of the strain PR8. Two died in 3 and 4 days respectively with massive consolidation of the lungs, 2 survived with consolidation of a considerable part of the lungs, and 4 showed no definite macroscopic lung lesions. Kangaroo rats inoculated with material from the consolidated lungs of the first passage developed only small lung lesions. Virus was demonstrated in the normal appearing lungs of 2 animals by subinoculation of mice and neutralizing antibodies for the strain PR8 were found in the serum of recovered animals. Of 4 kangaroo rats inoculated with the 97th direct ferret passage of strain PR8 none showed definite lung lesions. Two human throat washings demonstrated to contain the virus of influenza A by inoculation of ferrets were instilled into the noses of kangaroo rats and passage of material from the lungs and turbinates was carried out at intervals of 4 to 5 days. Neither lung lesions nor neutralizing antibodies to PR8 were demonstrated in any of the animals. The results indicate that mouse passage strains of influenza A are more virulent for Dipodomys than are strains from ferrets or human beings.

In preliminary work it was found that age was an important factor in the resistance of ordinary white mice to the influenza virus. Animals 4 to 6 weeks of age died regularly between 3 to 6 days after 0.05 cc of a 5% influenza filtrate was instilled into their nostrils. Older animals survived the same treatment for longer periods, in some cases as long as 17 days. Studies were outlined in an attempt to learn the effect of heat, cold, fatigue, and alcohol upon the resistance of mice to the virus. However, in early experiments it was found that old animals did not tolerate heat, cold and fatigue; therefore, 4- to 6-weeks-old mice were regularly employed.

The inoculum consisted of 0.05 cc of a 1:100,000 dilution of mouse lung tissue infected with the PR8 strain of influenza virus. It was prepared by grinding a 5% tissue suspension in broth of pH 7.2, centrifugating at 1600 rpm for 10 minutes and then passing the supernatant fluid through a Berkefeld N filter at a negative pressure of 50 cm of mercury. Many experiments were carried out, but only the following will be given since the findings were constant in; each instance.

Heat. A group of 9 mice was “hot-room” treated as follows: 6 were inoculated with the virus; the remaining 3 were used as controls. One-half hour after the inoculation, all the animals were placed in the hot room at 37°C and a relative humidity of 100%, for 24 hours. They were transferred to room temperature, 18°C, for 20 hours and then returned to the hot room for 10 hours. This completed the “hot-room” treatment. The animals were sacrificed' and autopsied at the end of the fifth day.

The intracranial inoculation of rabbits with the MV strain of poliomyelitis virus during insulin hypoglycemia did not produce neurological or pathological signs of anterior horn damage. These findings lend no confirmation to the theory of Sandler that hypoglycemia decreases the cellular oxidation of the central nervous system tissues, thus lowering their susceptibility to neuronal damage by the poliomyelitis virus.

1. The human influenza virus, PR8 strain, is resistant to treatment with 10% ether for at least 90 hours. 2. Influenza virus was present in the feces of mice 3 days after the intranasal inoculation of the virus. This was identified by neutralization tests. 3. In reporting these studies the source of the virus found in the feces has not been considered. There are several possibilities, the most important of which are: (a) The swallowing and survival of part of the material introduced into the nose at the time of the original inoculation, (b) Following multiplication of the virus in the lungs of the animals infected sputa was swallowed. In addition the multiplication of the virus in the digestive tract has been postulated and is being investigated. 4. No attempts have been made to isolate the virus from the feces of human patients with typical epidemic influenza.

The maxillary sinus may be the site of several types of benign cysts; this report deals only with the non-secreting type. These cysts form in the connective tissue of the antrum mucosa and are lined by loose connective tissue which contains many capillaries, along with numbers of leucocytes and reticulo-endothelial cells. These cysts vary considerably in size and require a period of weeks or months to develop to the point where they fill the antrum. They contain a clear fluid which coagulates rapidly after removal and has a yellow or amber tinge.

Little is known about the formation of these cysts or why they produce such definite symptoms in a patient. It was thought, therefore, that chemical analyses of the fluid obtained from these cysts might contribute some useful knowledge.

Experimental. The presence of the non-secreting cyst was determined by X-ray films of the sinus, which showed a large, rounded, soft-tissue mass lying in the maxillary sinus. To obtain the fluid from the cyst and to reach the anterior part of the sinus the antrum is punctured with a curved trocar and cannula. Because the cyst may lie anteriorly, the method of puncture must permit exploration of the anterior and inferior region of the sinus as well as posteriorly. The cyst may regress after puncture and lavage. Recurrent or large cysts require surgical removal.

The volume of fluid obtained varied from 2 to 10 cc, depending upon the size of the cyst and the efficiency of the puncture. The specimens were always clear with a yellow tinge and always clotted. The fibrin was removed by twirling on a glass rod and the clear filtrate was used for all analyses. The fluids used for pH and CO₂ determinations were collected under oil.

It has been shown that mixed phospholipid from blood plasma or egg yolk is rendered quantitatively insoluble in petroleum ether by the use of digitonin. Lecithin and cephalin obtained from egg yolk behave in a similar manner.

There was no evidence of fetal injury in cats following administration of large doses of scopolamine to the maternal animal.

The occurrence of respiratory depression and failure at birth following the administration of morphine for relief of pain during labor has prompted numerous clinical investigations. Two chief questions arise regarding the mechanism by which administration of morphine to the mother may result in injury of the fetus. There is involved firstly, the effect of morphine upon the fetus directly; and secondly, the effect of morphine upon the labor mechanism. Evaluation of these factors in clinical studies has been difficult because of the complications present at the time of delivery which may result in injury to the child such as anesthesia, anoxemia and∗ mechanical trauma. Accordingly, the present experiments have been undertaken in an attempt to control conditions of observation so that it could be determined whether or not the effect of morphine upon the fetus is of greater consequence than the effect of the narcotic upon the course of labor.

The effect of morphine on the fetus was first studied by direct observation of full-term rabbit fetuses within the unopened uterus according to a method previously described. 1 The change in rate of fetal respiratory movements afforded a sensitive indicator of the depressant effect of the narcotics. Results showed that rhythmical breathing of the fetuses persisted despite administration to the mother of more than 15 times the analgesic dose of morphine. 2

Additional evidence regarding the state of narcosis of the fetus at various intervals following injection of morphine was obtained in a second series of animals in which the rabbits were not prepared for observation of intrauterine respiration. A dosage of 13 mg per kg of morphine was given by a single intravenous injection in rabbits about the time of the onset of labor, i. e., at 31 or 32 days.

In the past 3 years many papers have appeared on the subject of audiogenic seizures. In continuation of previous work 1 it was felt that better insight into the phenomenon would be obtained if a method of recording the physiological factors involved could be devised. This paper describes such a method.

The heart rate was recorded by a Davis electroencephalograph. The 3 electrode leads were soldered to the tops of 3 bicycle valve caps; these caps were held on the animal by suction∗ applied through tubes leading to each of the caps. The electrodes were applied behind the right and left shoulders and on the midline ventrally. The hair on these areas was trimmed and Cambridge electrode jelly was applied. From these electrodes the heart rate of the animal was recorded (Fig. 1). Respiration (Fig. 1) was recorded by means of a Phipps and Bird accordion type pneumograph, on the tape of the electroencephalograph.

To obtain maximum quiescence during recording, advantage was taken of the rat's fear of height. The animal was placed about 5 feet from the ground with its forefeet and hindfeet on separate perches. These perches were one quarter inch wide and projected 2 inches from the middle of a vertical board. The distance between them could be adjusted to the size of the animal. With this procedure the rat remained almost motionless, and it was possible to adjust the pneumograph around the animal so that it was in contact with the animal only and did not touch any part of the apparatus. The weight of the pneumograph was counterbalanced by a weight on a pulley over the vertical board. This method also facilitated the placing of the ventral electrode.

In a study of the various resuscitation procedures in advanced asphyxia, over a hundred experiments were carried out in 43 dogs. During this work, it was observed that in the third phase of asphyxia (cessation of respiration and rapidly falling blood pressure), complete resuscitation of the heart and respiration can be quite regularly produced by rhythmic alternating insufflation and suction with an inert gas (nitrogen, helium), which had just been used to produce the asphyxia. Asphyxial resuscitation was administered at a rate of 15-20 complete strokes per minute, using a positive phase of + 14 mm Hg and a negative phase of −9 mm Hg. This resuscitation was continued until the first spontaneous respiration occurred and was then immediately discontinued and the animal allowed to breathe atmospheric air. (Fig. 1.)

The animals were anesthetized by intraperitoneal injection of nembutal (1 cc per 5 pounds). They were then asphyxiated by (1) obstructive (strangulation) asphyxia, or (2) nitrogen, helium, or nitrous oxide inhalation. Either a specially-fitting face mask and pharyngeal airway were used or else a special intratracheal catheter with inflation cuff to prevent leakage.

If asphyxia be allowed to reach the third phase (cessation of respiration, rapidly falling blood pressure), the animal ordinarily dies; but if asphyxial resuscitation be applied in this third phase at periods from one-half to 2 3/4 minutes after cessation of respiration, permanent resuscitation of the heart and respiration can be accomplished quite regularly.

Asphyxial resuscitation, using inert gas, was produced by manual artificial respiration in 15% of the animals, produced by rhythmic positive insufflation in 17%, and produced by rhythmic suction in 20% of the animals. This phenomenon, however, was produced in 85% of the experiments where the combination of rhythmic insufflation and suction was used. (Table I.)

Two technical problems which have presented considerable difficulty in experimentation on human vision are (1) providing a satisfactory “artificial pupil” through which a beam of light may enter the eye unmodified by the contraction and dilation of the real pupil of the eye, and (2) providing a stable electrical connection with the cornea for the purpose of making continuous records of polarity and action potentials of the retina.

The first of the above problems is met in the present experiments by coating the central portion of a contact lens† with black enamel, leaving an opening of the desired aperture in the exact center of the lens (Fig. 1). This arrangement has the advantage that a diffuse field of light may be used for stimulating the eye. The subject merely sits at a convenient distance from the stimulus field and fixates normally upon a fixation point, without the discomfort of maintaining a rigid posture of the head. Since the artificial pupil moves with the eyeball, small head and eye movements will not interfere with the transmission of the stimulating light to the retina.

The second problem mentioned above, that of maintaining an electrical contact with the cornea, is met by the use of a corneal electrode mounted upon a contact lens as shown in Fig. 1. The electrode consists of a silver disc cemented into a hole in the contact lens. The surface of the disc is flush with the inside surface of the lens. A fine, flexible wire, supported by beeswax, is employed as a lead from the electrode. When the lens is inserted into the eye, the silver makes contact with the physiological saline solution between it and the cornea.

In 4 of 5 cases of coronary occlusion the cardiac output fell rapidly, reaching its lowest level between the second and third day. The output began to rise soon after the third day and maintained a relatively constant level after the tenth day. In the 2 hypertensive patients (Cases 1 and 2) the cardiac output rose in spite of the fact that the blood pressure remained low.

Tyrothricin is markedly hemolytic for human and rabbit's erythrocytes. The hemolytic activity seems to reside primarily in the tyrocidine fraction, although gramicidin also exhibits a definite hemolytic effect. The addition of glucose to saline solution causes only slight inhibition of the hemolytic action.

Inhalation of a mixture of 10% oxygen and 90% nitrogen produced a moderate increase in blood flow through the leg and forearm and a decrease through the hand. These changes in peripheral blood flow were associated with a significant augmentation in pulse rate, a slight increase in the amplitude or number of respirations and no definite change in blood pressure.

During the last few years a number of swine in the Missouri Agricultural Experiment Station† herd have died from hemorrhage, either spontaneous or as a result of minor wounds. All of the affected animals are closely related. It is evident that the blood-clotting mechanism is seriously defective, and a study was initiated in an attempt to classify the abnormality.

Bleeding Time. If determined by Duke's method 1 the bleeding time is within the normal range. As shown in Table I though, if an incision of any extent is made the bleeding time is prolonged indefinitely.

Coagulation Time. The procedure followed is essentially the same as the Lee-White 2 modification of Howell's method. The blood sample is taken from an ear vein, collected in cold paraffin coated tubes, and placed in an ice bath. The results reported in Table I show that the coagulation time was 5 times that of normal blood. The blood clots slowly, but after it forms it retracts in normal time.

According to the prevailing theory at least 4 components of the blood are intimately concerned with blood coagulation: (1) calcium; (2) prothrombin; (3) fibrinogen; (4) thromboplastin, which presumably is released from the platelets and other formed elements. Each one has been subjected to preliminary investigation.

Calcium Time. According to our observations the calcium time 3 is not less than the coagulation time, and the serum calcium was shown by analysis to be well within the normal range. Our data on calcium are omitted from the tabulations.

Fibrinogen Content. Oxalated plasma was diluted with isotonic saline and recalcified. The resulting fibrin was removed and determined quantitatively. The data shown in Table II indicate that the blood of defective animals contains slightly less fibrinogen than does that of normal controls, but the quantity is more than enough to form a normal clot.

Methylcholanthrene will deplete rat livers of vitamin A in 3 to 6 weeks; phenanthrene or lard injections will not. Some strains of white rats are not readily susceptible to tumor production by intraperitoneal injections of the drug and regain their ability, after discontinuance of injections, to store vitamin A in the liver.

Theoretical considerations predicted and the experiment here recorded have proved that in the rhesus monkey the ovaries are not necessary from the twenty-fifth day of pregnancy on for normal gestation, parturition at term, postpartum involution of the uterus and lactation. Surprisingly, the bright red color of the sex skin was maintained, in the absence of the ovaries, not only during gestation but also during lactation.

With one exception (as discussed) no significant difference was found in the absorption of sulfathiazole as judged from studies of blood concentration, after oral, intrapleural, and intraperitoneal administration to dogs. Although these experiments are not directly comparable to the clinical use of sulfathiazole, they may well serve as a guide in the matter of dosage in the local application of the drug to the pleural and peritoneal cavities.

In view of the successful production of tumors by crude coal tar 14 and its derivatives with known chemical composition, 1 , 2 , 3 , 4 interest has been directed to the question whether tars prepared from substances which we eat or smoke are also carcinogenic. Fukida and Kinosita 5 found that tar from rice bran is carcinogenic to the skin of mice. Kenneway 6 produced cancers and papillomas by human skin tar and yeast tar. Shibata 11 reported on the carcinogenic action of the tar from sugar. Roffo 8 found tumor growths in the stomach, liver, and cecum of rats fed on bread and milk to which was added animal fat or olive oil that had been heated to 350° C for half an hour. Widmark 13 succeeded in obtaining adenocarcinomas of breast with alcohol or petroleum-ether extract of roasted horse muscle, coffee and brown butter. LÜ, 7 Taki, 12 and Sugiura, 10 etc., produced tumors on mice by tobacco tar. Roffo 9 was able to identify the presence of 1-2 benzpyrene, a carcinogenic hydrocarbon, in tobacco tar.

The following experiment was carried out to find whether tars from certain common food articles also have carcinogenic properties.

Material and Method. The material consisted of polished rice, pea flour, soybean, casein, wheat gluten, whole wheat, corn, cabbage, pepper, beef, and pork. Each of these, in dry form, was placed in an iron retort to about one-half of its full capacity and was then heated on a strong gas flame for destructive distillation. The distillate was collected in a water-cooled receiver. To remove the small amount of water present, the distillate was shaken with an equal part of chloroform.

Lillie, Daft and Sebrell, 1 among others in the past few years, have reported liver cirrhosis in animals given special diets. György and Goldblatt 2 reported liver injury as a regular complication in rats on a diet containing 10% casein and 22% fat. Necrosis or cirrhosis or both was observed from the 100th to 150th experimental days. They state “Addition of from 10 to 20 mg of choline daily reduced the incidence and severity of the liver injury but not to a great extent.” In a later paper György, Poling, and Goldblatt 3 refer to this work and state “These changes can be prevented to a large extent by the addition of casein to the diet, but this is accomplished more effectively by the combined oral administration of cystine and choline.” Blumberg and McCollum 4 reported that liver cirrhosis in rats on a diet containing 10% casein and 55 or 70% fat, occurring in 125 to 150 days on the lower fat intake and in 100 to 140 days on the higher, could be prevented by including 10 mg per gram of choline in the diet and could be slowed but not prevented by methionine at 25 mg per rat per day. Earle and Victor 5 reported liver cirrhosis in 14 to 27 days in rats given a diet containing 10% cystine. They also reported cirrhosis in one of a number of rats given a diet containing 5% cystine.

We wish to report at this time the consistent and fairly rapid production of liver cirrhosis in rats on a low protein, low fat diet with added cystine and the apparent prevention of the cirrhosis by choline, methionine and casein, singly or in combination.

In connection with studies on the effect of intravenous injection of rats with hemolytic streptococcus extract toxin 1 ∗ (toxic serum extracts of hemolytic streptococci), we discovered that under certain conditions large cytoplasmic bodies appear within the liver cells. On further study, we found that other proteins also caused the development of similar bodies. This preliminary paper deals with the methods used for the production of this lesion and its description and is based on a study of 850 rats.

In Table I are presented: first, the substances that cause the lesion when injected intravenously; second, the percentage of body weight of the substance injected; third, the time elapsing between injection and autopsy. In Table II are presented the substances studied that, under the conditions of these experiments, have not produced inclusions.

The important factors in the production of the lesion are as follows:

Age of Animal. In order to obtain lesions regularly, rats should be at least 7 weeks old. When younger rats are used, the results are often negative.

Amount of Substances Injected. In general, the number and size of the inclusions obtained appear to be directly proportionate to the percentage of body weight of inoculum. To produce numerous and large inclusions, 1 to 3% of the body weight of the substance should be injected.

Earliest Time After Injection of Appearance of the Inclusions. The time of the appearance of the inclusion after injection varies with the material injected. Thus, when streptococcus toxin was injected, the inclusions first appeared at 2 hours after injection but were absent in 30 minutes. (No rats were killed sooner after injection than this.)† With sheep serum (2% of body weight) numerous “early” inclusions were found in 9 of 10 rats within 10 minutes after injection and even in one rat killed immediately.

A substance which acted destructively upon the myelin sheaths of rat spinal cord could be demonstrated in the urines of patients suffering from disseminated sclerosis. It was more frequently observed during periods of exacerbations than during periods of remissions. Similar myelolytic substances were also observed in cases of post-encephalitic Parkinsonism, but they were absent in syphilis and in other diseases of the central nervous system. This myelolytic substance could be isolated from the concentrated urines by extraction with dioxane.

The average blood lactic acid in 7 cases of preeclampsia was 12.9 mg % (8.0-18.6) as compared with 11.0 mg % (9.1-12.3) in 8 cases of normal pregnancy. The average blood acetone bodies in the pre-eclamptic cases was 0.8 mg % (<0.1-2.6) as compared with 1.3 mg % (<0.1-2.7) for normal pregnancy. The average blood uric acid for the pre-eclamptic group was 4.5 mg % and for normal pregnancy was 3.0 mg %. The rise in blood lactic acid in eclampsia occurs mainly after convulsions. The hyperuricemia of pre-eclampsia and eclampsia can not be primarily attributed to an elevation of blood lactic acid or acetone bodies.

A new Salmonella type, S. illinois, is described. It has been found in hogs, partridges and turkeys. The antigenic formula of the bacillus is (III) (XV) XXXIV:z₁₀—1, 5 ….

Of the 4 serological types of Vi-phage propagated on Ty2 strain of V form B. typhosus, only the Type I Vi-phage failed to show noticeable protective action under the specified experimental conditions. The Type II, III and IV were found to be equally effective in their protective action.

Intravenous administration of 0.1 g or more per kg of SSS produces death in normal dogs. 0.03 g per kg was found to be compatible with life. Injection of this quantity produced marked alteration in the usual course of the disease. Although serum-leukocyte mixtures did not always show complete abolition of blood pneu-mococcidal power, the presence of this substance in the blood and tissues resulted in overwhelming bacteremia, inability of the dog to localize infection and impaired phagocytosis in the pulmonary lesion.

It had previously been noticed that certain serums from healthy domestic fowl in California 1 showed neutralizing antibodies against the Br strain of western equine encephalomyelitic virus. Serums from areas where this disease is endemic appeared to yield more positive results than those from supposedly non-endemic regions. A correlation had also been observed with human serums between the presence of antibodies for both the western equine virus and that of the St. Louis encephalitic type. About 26% of 69 serums of encephalitic patients in the Central Valley areas of California were positive to both viruses. 2

To determine if a similar relationship existed with animals, neutralization tests were performed on serums of domestic fowl and horses collected from endemic and presumably non-endemic areas of California.† The same technic and the same strains of virus (Br and St. Louis) were used as previously described, 1 the serums being considered positive or weakly positive according to the number of virus dilutions neutralized.

It was interesting to find that antibodies against the St. Louis virus were present in the blood of many horses and domestic fowl and that, with but a few exceptions, they were in association with the neutralizing substance against the western equine virus. Of 43 unvaccinated normal horses and 2 recovered animals from the endemic regions of Kern, Fresno and Yolo Counties, all (95.3%) except 2 showed neutralizing antibodies against the western equine virus. With the exception of 10, the serums were positive to the St. Louis virus as well, but none was positive to the latter alone. Serums were tested from 19 horses vaccinated against the equine strain in a Northern California area. All were positive to the homologous virus but were negative to that of the St. Louis. Of 3 unvaccinated animals 2 were negative to both strains and one weakly positive to the equine.

1. The comparative effect of X-rays and neutrons on the survival of 3 mouse tumors was studied. 2. Both X-ray and neutron irradiation in vitro resulted in delaying the appearance of the tumors—mammary carcinoma being the most affected. 3. Some cases of regressions in the growth of lymphoma were noted after neutron and X-ray irradiation. 4. When the doses at the 50% survival point were compared, the X-ray/neutron ratios of the 3 tumors, lymphoma, mammary carcinoma, and lymphosarcoma, were found to be 5.8, 6.1, and 7.5 respectively. These ratios do not seem to indicate a significant difference in the sensitivity of the tumors to the radiations, but do show that per unit of ionization neutrons are more biologically destructive than X-rays.

Several years ago 1 we reported the observation that a diet, adequate with respect to vitamin D and phosphorus but deficient in calcium, will produce a skeletal structure which is hard but light and fragile, in young growing animals. The thin-walled bones, showing no evidence of rickets, do not bend easily, have a nearly normal bone ash, and are not enlarged at the ends. Spontaneous fractures are common and are located at the point of greatest stress which varies with different species. In calves and dogs the fractures usually occur in the femur. In rabbits we find the vertebrae are the common site of fracture. Boelter and Greenberg 2 recently reported that rats on a low calcium diet frequently have spontaneous fractures of the long bones. According to our interpretation of their observations the vertebrae of rats are also susceptible to fracture.

During our study of this problem we carried out an experiment, using 5 litters of rabbits. Four of the litters were divided at weaning (3-5 weeks of age) each into 2 groups. Half of each litter was placed on a basal diet composed of whole oats 60%, alfalfa 18%, molasses 2%, whole wheat 10%, cracked yellow corn 8.5%, NaCl 0.5%, Na₂HPO₄ 1%, plus irradiated yeast to supply 6.5 U.S.P. units of vitamin D per gram of ration. The other half of each litter received this basal diet plus 1% CaCO₃. The basal ration contained 0.199% Ca and 0.513% P. The fifth litter was treated in the same manner, except that these animals were 8 weeks old when they were removed from their mother's pen where they had access to a commercial rabbit feed. This interval on a normal feed evidently carried the young past a critical period, since the animals of this litter placed on the basal ration remained healthy and their growth was equal to that of their litter mates fed the basal ration plus 1% CaCO₃.

1. The thiamin and pyrimidine excretion in the urine of older subjects, after different levels of thiamin intake, was measured by the fermentation method of Schultz, Atkin and Frey. 2. There appears to be a sex difference in the excretion of thiamin which is not apparent in the excretion of pyrimidine. 3. The response of people in this age group to increased thiamin intake is similar to that of younger people so far as excretion is concerned. 4. “Retention” calculated as thiamin intake minus thiamin plus pyrimidine excreted, was more nearly proportional to intake than was the amount excreted. 5. Six out of the 8 subjects reported some type of subjective reaction to the increased thiamin intake. Physical examinations before and after the experimental period revealed no significant changes.

Recent work by Krichesky, et al., has demonstrated the effect of testosterone propionate on prostatic implants in the eye of the male rabbit, and has confirmed earlier reports that maintenance of the transplanted accessory tissue is dependent on the normal functioning of the testes, since castration results in atrophy of the transplanted tissue. 1 In undertaking a similar experiment in which 2 different gonadotropic agents were administered, a consistent response was observed which, to the writers' knowledge, has heretofore been unreported.

Fifteen male rabbits from 4 to 6 months of age were completely prostatectomized and bits of the excised tissue implanted into the anterior chamber of the eyes following the technic described by Benjamin, et al. 2 Of the 60 transplants (4 per animal) 36 remained observable and in an apparently normal physiologic condition. A photographic method was employed in recording the day by day area of the transplants. The areas of individual transplants were calculated by means of a planimeter and the average value over a 2-week period was taken as 100% for that implant. An increase in area was then expressed as greater than 100% and a decrease as less. than 100%.

All animals were injected subcutaneously 6 days per week for a 2-week period with either chorionic gonadotropin (APL) or hypophyseal gonadotropin (Anterior Hypophyseal Gonadotropic Factor).‡ In 5 cases, after the animals had undergone such a series of injections with one hormone, they were allowed to rest for approximately one month and were then subjected to a second series. of injections with the other gonadotropic agent. The results were in no way distorted by this procedure since the character and magnitude of the responses were not different from those animals given only one series of injections.

Macxy 1 predicted that rat and mouse may be the reservoirs and tick, mite, or flea may be the transmitters of typhus fever in the southern parts of the United States. This prediction had been satisfactorily fulfilled except for the possibility of mites as vectors. 1 , 2 , 3 , 4 , 5 While Shelmire and Dove 6 , 7 and Kodama and Kano 8 have experimentally transmitted typhus Rickettsia in laboratory animals by rat mite, no special attention was attached to this vector as an important carrier of typhus Rickettsia. In this communication, we wish to present a first instance of isolation of typhus Rickettsia from mites naturally infected and to discuss briefly its possible epidemiological significance.

A rat trapped in July, 1940, at the end of a typhus epidemic which has occurred in an orphanage was found to harbor 3 mites identified as Liponyssus bacoti. From them, a strain of typhus Rickettsia was established in guinea pig and white rat according to the following criteria: Fever in guinea pig and albino rat, positive Weil-Felix reaction in most of the inoculated rats, in some cases as high a titer as 1:320, recovery of Rickettsiæ on direct examination and cultivation of the tunica vaginalis of infected guinea pig, and finally, positive cross-immunity with a known strain of murine typhus. A second group of rat mites from the same orphanage 4 months after the epidemic showed suggestive findings on inoculation into albino rats but was not further studied. Material from the rat which harbored the first group of mites produced a suggestive typhus infection on inoculation into albino rats.

Comment. The prediction of Macxy that the mite may be a vector of typhus fever has been further supported by the isolation of a strain of typhus Rickettsia from naturally infected mites during an epidemic.

1. Intravenous injections of emulsions of lecithins extracted from soy bean, corn, vegetable, cod testicle and erythrocytes of man and cephalin of soy bean produce a marked miosis in the completely denervated iris of the cat but not in that of the monkey, dog or rabbit. 2. Synthetic lecithin in much smaller concentrations yields identical results. 3. None of the phospholipid miotic effects is blocked by atropine or potentiated by eserine.

The preventive action of tablets of different hormones against uterine and extragenital peritoneal fibroids elicited by estradiol in the guinea pig has been compared. Desoxycorticosterone acetate is quantitatively more efficient than testosterone propionate. Desoxycorticosterone is also more efficient than testosterone in antagonizing other effects of estradiol such as opening of the vagina and increase of the uterine weight.

It has long been known that among the cells of the mammalian liver, there are some which have more than one nucleus. Most of such multinucleated cells contain two nuclei and are thus called binucleated hepatic cells. During fetal life only small numbers of binucleated cells are found, but after birth the number gradually increases until adolescence, after which time, under normal conditions, the number of cells remains constant. Each animal species has a definite percentage of binucleated cells which is equal in the various lobes of the liver and is more or less characteristic of the species. 1 Several investigators have shown that there are more binucleated cells at the periphery of the lobules than at the center. 2 , 3 Although there is no conclusive evidence to support the idea, these cells are supposed to result either from hyperactivity and incomplete karyokinesis or from fusion accompanying degeneration. 4

Szittay 3 reported that the daily administration of 3 cc of Vigantol over a period of 8 days to young rabbits led to an increase in the number of binucleated cells in the periphery of the lobule, although no changes were found in the central zone. The number of cells with 3 and 4 nuclei was slightly increased in the same region, but there was no increase in the number of mitoses. Szittay thought that his findings indicated increased activity in the peripheral zone of the lobule rather than a toxic action of vitamin D upon the liver. These observations are of interest because clinical and experimental studies suggest that the liver plays an important role in the action of vitamin D. 5 , 6 , 7 Since Szittay's experiments seemed to constitute anatomical evidence of the action of vitamin D on the liver it was decided to repeat them.

1. Administration of vitamin K in the dietary of chicks definitely decreased the mortality in chicks parasitized by E. tenella, a hemorrhage-producing protozoan, since all autopsies performed show the vitamin K-protected birds had a fibrinated core in the caeca, which was in the process of being reabsorbed. 2. Vitamin K-protected birds showed a mortality of only 10% in comparison to 70% mortality in the unprotected group.

1. The volume of nitrogen excreted from the body by way of the lungs, when a subject breathes pure oxygen for short periods, is found to vary with the size of the individual. 2. The nitrogen excretion during 7 minutes of oxygen breathing has been determined in 30 normal individuals of various ages and sizes. The values obtained have been correlated with body weight and with surface area. Coefficients of correlation and regression equations are given.

Man, in contrast to lower mammals, 1 can retime the action phase of a transposed muscle in accordance with its new function. Just how this occurs, is largely unknown. A systematic investigation of “recoordination,” therefore, offers points of great theoretical and practical interest. A first report of our results is herewith presented.

Technic. The muscular action potentials were amplified in an ordinary vacuum tube amplifier set and recorded by an electromagnetically driven stylus writing on “Teledeltos” paper. Before entering the recorder, the amplified action currents passed through rectifying and integrating sets, partially summating and integrating individual spikes so as to give an estimate of the intensity of the contraction. Three identical channels were in operation, admitting independent simultaneous recording from three muscles. Provisions were made for the synchronization of these records with motion pictures. The electrodes consisted of copper mesh embedded in moist agar pads and strapped to the skin, cca 1 inch apart. Needle electrodes inserted through the skin did not prove significantly superior to surface leads. Elaborate precautions and checks were devised to guard against leakage of current from other than immediately subjacent muscles.

Tests. For the sake of standardization, the tests were restricted to a single type of operation, namely, transposition of the tendon of the M. biceps femoris to the extensor side of the knee joint to substitute for the weakened or lost action of a paralyzed M. quadriceps. The action of the transplant was to be compared with its preoperative flexor and extensor relations. The muscles chosen to represent the knee extensor and flexor group were the residual M. rectus femoris and the inner hamstrings, respectively. The action phases of these muscles during a number of standardized test performances (simple voluntary movements on command, resisted and unresisted; from prone, supine, seated, standing position; stretch reflexes; walking; bicycling; stooping, etc) were determined in both normal and polio-myelitic (unoperated) individuals.

This report is based on 19 completed experiments designed to reëvaluate the usefulness of human convalescent serum.

From these experiments it would appear that it is possible to protect a significant number of 3-week, 10 g mice against intracerebral inoculation of poliomyelitis virus (Armstrong strain) by the intraperitoneal administration of from 0.03 to 0.5 cc of potent human convalescent serum—protection being somewhat more evident in those mice receiving larger doses of serum. Evidence of protection is furthermore obtained when the serum is administered up to 24 but not 48 hours after intracerebral infection.

Under the experimental conditions there appears to be no evidence that convalescent serum had any therapeutic effect, even when this was administered continuously from 24 hours prior to infection to 9-15 days following infection. Animals that succumbed to the disease did so within the usual incubation period and died, as did the controls, from one to five days after the onset of paralysis.

No attempt is or can be made at this time to translate the results of these experiments in terms appropriate for human application. They are reported, however, because we believe they represent the first definite evidence of significant protection with human convalescent serum under the experimental conditions.

The electrical resistance of an ordinary conductor is independent of the magnitude or direction of a current sent through it, and a current may pass with equal ease in either direction. There have been suggestions, however, that in a nerve fiber membrane, current may pass more easily in one direction than in the other, or that the nerve fiber membrane behaves as a rectifier rather than a simple resistance.

Recently, Cole and Baker, 1 and Cole and Curtis 2 demonstrated rectification in the squid axon, using alternating current bridge methods and the needle electrode technic. Another paper, Cole, 3 shows that the previous failure of Cole and Hodgkin 4 to observe rectification in this axon was due to the fact that only small currents had been used and to the fact that the effect under the anode was approximately equal and opposite to the effect under the cathode, thus neutralizing it.

By killing one end of the nerve fiber, neutralization of rectification under one electrode by that under the other can be avoided, and it should be possible to observe rectification directly by means of a much simpler technic involving a direct current Wheatstone bridge.

The giant nerve fiber of the hindmost stellar nerve of the squid, Loligo pealii, was used throughout the experiments. It was carefully dissected away from the smaller nerve fibers under sea water with the aid of a binocular microscope. Immediately after dissection the axon was threaded through a glass U tube filled with oil. Then the U tube was suspended by means of a glass rod cemented to it in such a way that one end of the fiber dipped into sea water, where it remained in good condition for many hours, and the other end into KC1 isosmotic with sea water (0.52 M), which injured that end.

Successful infection of animals with a virus recovered from influenza patients 1 laid the foundation for experimental study of the mode of transmission of this important respiratory disease. Intranasal instillation of influenza virus recovered from artificially infected air 2 proved air conveyance of the virus to be possible, and destruction of the air-suspended virus by ultraviolet irradiation raised hopes of environmental control of epidemic influenza by sanitary ventilation. Demonstration of air-borne influenzal infection of ferrets 3 and introduction of quantitative inhalation technics of inoculation 4 provided experimental means for study of air-borne influenza and air-borne superinfections which frequently complicate the pathologic and epidemiologic patterns.

The experiments to be presented have been conducted during the fall and winter of 1939-40 when other duties delayed the continuation of this study until a preliminary report seems desirable. Of the 25 experiments performed, employing some 1500 mice, protocols have been chosen to illustrate our interpretation of the observed phenomena. These results have been found reproducible in repeated tests, but the exploratory nature of the protocols did not adapt them to statistical summary.

Experimental. I. Air-borne Transmission of Influenza A Virus. Exposure of white mice to air which had been infected by droplet nuclei derived from a suspension of the virus of influenza A produces typical signs of the disease in these animals and causes death with sufficiently high concentration of the virus. All mice exposed 45 minutes to air infected by atomizing 1 g of a 10% suspension of mouse lung (infected with PR-8 5 or WS 1 strain) in 50 cubic feet of air died within 6 to 9 days. (Table I.) If one-tenth of this amount was used for the spray, 30% of the mice succumbed and the remaining animals harbored severe lung lesions when autopsied on the tenth day.

Under the stress of increased metabolic rate, due to dinitrophenol injection, liver phospholipid and cholesterol are decreased. These changes are consistent with the belief that at least part of the phospholipid and cholesterol of the liver are important in fat metabolism.

The authors wish to express their thanks to Dr. W. R. Bloor for his advice on this problem.

(1) As earlier workers have shown, acid dyes do not localize in tumor cells but in the stroma surrounding the tumor. (2) Further localization takes place within the tumor at each interface of viable and necrotic tissue. (3) The initial localization consists of a diffuse staining of the peripheral stroma and the seminecrotic cells within the tumor between viable and necrotic zones. (4) This diffuse dye is progressively phagocytized, and after 24-48 hours, appears in numerous macrophages at the tumor edge. (5) The dye is so located that if it were replaced by a radioactive substance, theoretically effective radiation of the tumor edge should result. (6) After a single large dose of dye the reticulo-endothelial cells of liver and spleen are rapidly filled with dye droplets. These disappear or diminish substantially after several days. (7) In addition to tumor and reticulo-endothelial systems of liver and spleen, the kidneys take up considerable quantities of dye, as this is the chief channel of excretion. Accumulation in the kidney might prove to be a complicating factor in the use of radioactive materials, but in the case of induced activity, as with lithium by slow neutrons, appropriate shielding during irradiation should overcome this difficulty. (8) Small repeated doses of dye do not localize in greater quantities than does the same amount given at a single injection. Furthermore, the reticulo-endothelial system is blocked by small repeated doses. (9) X-ray treatment does not appreciably alter the amount of dye localizing in tumors, as determined by histological examination. (10) There is a marked difference in behavior, as regards tumor localization, between the colloidal dyes used and colloidal carbon. (11) Brief preliminary report is made on the localizing properties of some heretofore untested dyes.

Humoral antibodies against the virus of St. Louis encephalitis can be demonstrated in the sera of hamsters inoculated by subcutaneous, intracerebral, intranasal and oral routes provided the animals survive the infection 7 days or more.

After subcutaneous inoculation, antibodies may appear in the serum within 48 hours after inoculation. They persist at high titer for many weeks. When inoculated intranasally or intracerebrally, some animals fail to develop antibodies prior to death and others which develop a high protective titer still succumb to the infection. Animals dying as long as 6 days after intracerebral or intranasal inoculation may fail to show neutralizing antibodies. No animal inoculated subcutaneously has failed to show humoral antibodies after the second day. The presence of humoral antibodies does not insure immunity against the disease.

Although the presence of androgenic substances in the placenta is mentioned by several authors, these fail to make any specific citation to the original work, and an examination of the more common indices is no more encouraging.

Siebka 1 examined 2 placentae following operative abortion and failed to find any androgens in the 4-5-month-old organs. If there is any positive evidence of the occurrence of androgens in the placenta, it has not found its way into the current literature.

The purpose of this study was to determine whether or not the presence of androgens in the placenta could be demonstrated.

Three male and 3 female full term placentae were secured, washed as free of blood as possible and extracted according to the Gallagher and Koch method. The extracts were assayed both on capons and by the colorimetric methods.

The colorimetric assay∗ indicated the presence of one international unit in 60.7 g of male placenta, and one I.U. in 69.4 g of female placenta. The capon test showed for the male placentae one I. U. per 226.9 g of tissue; the female one I. U. per 371.5 g. Only two birds were used for each test and the difference in response was in one case about 100%, in the other about 50%. Lack of material prohibited the use of more birds.

While the experiments give positive evidence of androgens in the placenta, they may not be taken as quantitative. The wide variation between the colorimetric test and the capon assay is confusing, but may be related to the relative amounts of androgens or 17 ketosteroids. No effort was made to determine which of the 17 ketosteroids were present.

It is rather interesting, although it may not be significant, that the male placenta contains considerably more hormone, by both tests, than the female.

Fourteen rats, hypophysectomized 1 to 5 days after mating, were injected with lactogenic hormone (1 or 3 mg daily). In 4 animals implantation failed to occur. Of the remaining 10 animals 2 carried to term or beyond, while pregnancy was interrupted after 6-17 days in 8 rats. It would seem that lactogenic hormone was capable of stimulating corpus luteum function sufficiently to induce implantation and to maintain pregnancy for periods ranging from 6 days to term or beyond.

It was recognized early that in lymphogranuloma venereum, unlike most other virus diseases, some success attended treatment of infected mice or guinea pigs with drugs of the sulfonamide group. The earlier work has been summarized by Findlay. 1 In a previous communication from this laboratory 2 it was indicated that, in preliminary experiments, sulfapyridine and sulfathiazole given orally in the form of the free acid twice daily after infection were equally effective in preventing death of mice infected intracerebrally. In these experiments mouse brain was used as inoculum, and even with a 1 in 10 suspension only 63% of the control mice died. In subsequent papers Findlay 1 , 3 repeated his earlier results with sulfanilamide, showing a reduction of mortality from 84% in the controls to 49% in those fed sulfanilamide in gum acacia daily. 3 He further attempted to assess the relative value of sulfanilamide, sulfapyridine, sulfathiazole, sulfamethylthiazole and disodium 4:4 bis-o-carboxybenzoylaminodiphenylsulfone. 1 The mice received 10 mg per 20 g of body weight in 2 equal daily doses orally by stomach tube for the first 4 compounds and subcutaneously for the last. One hundred mice were treated with each compound, together with 100 controls, and the ratio of treated survivors to control survivors was used as a method of comparing one experiment with another. On the basis of his results, Findlay maintained that the order of activity ran: sulfamethylthiazole > sulfapyridine > sulfathiazole > sulfanilamide > lutazol. Smaller experiments with compounds inoculated intramuscularly in olive oil indicated slight activity for ammonium 4-nitrobenzene-sulfonate and 4:4-dinitrodiphenylsulfone.

All of the previous work had been carried out with virus material of low titer derived from infected mouse or monkey brain.

Luminescence intensity is inhibited at once on addition of sulfanilamide either to broth cultures, or washed cell suspensions of luminous bacteria in phosphate buffered NaCl solutions containing glucose as oxidizable substrate. At the respective optimum temperatures of marine species, Achromobacter Fischeri (25 to 28°C), Photobacterium phosphoreum (15 to 17°C), and a fresh-water species, Vibrio phosphorescens (28 to 30° C), a concentration of 100 mg % sulfanilamide greatly reduces the intensity of luminescence, with little or no effect on the rate of respiration (Fig. 1). Except at high concentrations of the drug the inhibition of luminescence is largely or completely reversible (Table I) by centrifuging and resuspending the cells in a drug-free solution. In all these respects the effects of sulfanilamide resemble those of typical narcotics, such as the urethanes 1 , 2 and barbital. 3 By analogy, it would be predicted that sulfanilamide will inhibit the luminescent oxidation of purified Cypridina luciferin and luciferase in vitro. 4

Growth of luminous bacteria in nutrient broth is prevented by high concentrations of sulfanilamide (500 mg %), while lower concentrations retard growth and sometimes allow the development of cultures which do not luminesce. In sub-cultures of the latter, luminescence reappears, showing that no permanent change in the characteristics of the organism has taken place.

Concentrations of sulfanilamide which reduce luminescence intensity to as little as 10% cause neither an appreciable bactericidal effect, nor a reduction in number of luminous colonies in the plate count (Table II).

Para-aminobenzoic acid 5 at high concentrations (50 mg %) inhibits growth and luminescence, but exerts anti-sulfanilamide effects on broth cultures at much lower concentrations. Para-aminobenzoic acid does not, however, have any appreciable effect on the sulfanilamide inhibition of luminescence in mature cultures or washed cell suspensions, over a range of 0.001 to less than 0.0000001 M.

Sensitization to intravenous injections of acetylcholine by sympathetic denervation of the hind limbs of cats is demonstrated plethysmographically. It is emphasized that care must be taken to remove completely the sympathetic supply to the limb in question in order to observe sensitization.

Specially treated bone was used to close the intestinal loop previously described. 1 Experience has shown that it is difficult to obtain uniform preparations of bone which will not eventually disintegrate after an exposure of some months to the action of intestinal juices. This difficulty has been overcome by substituting stainless steel wire mesh for bone. A 3/4 inch width of 30 mesh stainless steel wire mesh∗ is wound around the rubber tubing until the desired thickness of “bone” is obtained. The rough ends are closed by vulcanizing rubber onto them, which thus fastens the wire to the tubing. A porous matrix through which the serosa can grow is thus established. Loops closed in this manner are intact after 6 months of use, and show no sign of leakage or disintegration. Vitalium wire mesh was also satisfactory but costs several times as much as stainless steel.

One other troublesome factor, that of the inserted end of the rubber tubing puncturing the walls of the loop, has been eliminated. A roll of rubber was vulcanized around the end of the tubing which was inserted into the loop at the time of operation, thus eliminating sharp edges of hard rubber. No punctures have occurred since this practice was begun.

It is desired to report the development of a transparent, reproducible medium, containing no heat-labile material such as serum, which is sufficiently stable to withstand autoclave sterilization and storage, and which will support satisfactory primary growth of either meningococci or gonococci. The latter were used as the test organisms during the experimental work, since a constant source of primary cultures of the meningococcus is ordinarily not available. The similarity between the two organisms, and the reputedly greater difficulty expected in the cultivation of the gonococcus, indicated that a medium suitable for this organism should prove equally satisfactory for the meningococcus.

As a basis for comparison, the Difco “Proteose No. 3 Chocolate Agar” has been used. This medium has been adopted as a standard in certain laboratories for the diagnosis of gonorrhoea 1 and one of us (J.H.) was thoroughly familiar with its use.

The plan as formulated in beginning the experiments was essentially that followed with considerable success with other organisms, namely, to select the most suitable empirical medium available and attempt to break it down to its essential component parts. The experience of the senior author in 1918 with the Gordon and Hine 2 pea meal extract agar for meningococcus carrier detection had shown that this medium, when carefully prepared, was eminently satisfactory. It proved, upon trial, to be equally so for primary cultivation of the gonococcus, and it was therefore chosen as the starting point in the investigation. It consists essentially of a tryptic digest of meat, agar, and a 5% NaCl extract of pea flour, the latter presumably supplying some essential protein material.

The fractionation of the pea extract proved surprisingly simple, since it could be accomplished by mechanical means.

The finding of an increase in pancreatic insulin produced by prolonged estrinization of normal rats has been confirmed. It appeared possible that this effect might be mediated by the pituitary which in such estrinized rats is greatly enlarged. A stimulation of production and secretion by the pituitary of greater than usual amounts of a'pancreatrophic hormone' might account for the observed facts. The pancreatropic potency of the pituitaries of such estrinized rats was therefore tested, in comparison with that of untreated animals. No pancreatrophic action was evident upon implantation of 9 pituitaries of control rats. ∥ The same number of pituitaries of treated rats caused a slight increase in pancreatic insulin content, which by itself, cannot be regarded as sufficient evidence for the increased pancreatrophic potency of the glands. The hypothesis that the effect of the estrogen is mediated by the pituitary is, however, supported by the outcome of the second experiment, i. e., the failure to produce pancreatrophic effects in hypophysectomized rats with the same estrogen treatment which had marked effect in normal rats. That this failure was not due to the pronounced toxic action of the estrogen in such rats was demonstrated by its lack of effect also in rats receiving pituitary substitution therapy besides the implanted estrogen.

It is also noteworthy that estrinization does not lead to increases in liver weights or liver glycogen storage in hypophysectomized rats, as reported for normal rats. 4 It would thus appear very probable that the effect of estrogens on pancreatic insulin content as well as on liver weight and glycogen is mediated by the pituitary gland. Evidence will be discussed elsewhere 8 which indicates that the lactogenic hormone exerts a pancreatic insulin increasing action in normal and hypophysectomized rats. The recent finding 5 , 6 that the lactogenic hormone content of and excretion by the pituitary appears to be increased in estrinized rats stands thus in good agreement with the reported observations of an increased'pancreatrophic' function of the pituitaries of estrinized rats.

Summary. Two types of evidence favor the assumption that the activity of estrogens in elevating the pancreatic insulin content is mediated by the pituitary. (1) The pituitaries of estrinized rats when implanted elevate the pancreatic insulin content of the host animals while the pituitaries of untreated rats do not show this activity. (2) Estrogen which raises pancreatic insulin content in normal rats does not produce this effect in hypophysectomized rats.

Twenty-two samples of human sera were tested and 6 were positive. They gave agglutination with their own and all homologous strains used. Crossed agglutinations were seen with none, but the element of time in the method employed should be reiterated. The agglutinations were read immediately and by 30 seconds the slides were discarded. The 6 positive sera were from 3 patients with purulent otitis media, 2 of these scarlatinal, 2 patients with empyema, and one patient with paronychia and axillary adenitis.

Conclusions. In 6 of 22 samples of convalescent human sera slide agglutination with the homologous hemolytic streptococci was detectable.

The lability of the Vi antigen of the typhoid bacillus has been emphasized as its most marked characteristic. Felix and Pitt 1 , 2 found that Vi antigen was destroyed in 90 minutes at 58°C and in an hour at 100°C and disappeared when treated with alcohol, chloroform or toluol. Exposure to ether resulted in a partial loss of the substance. Kauffmann 3 suggested the use of formalized suspensions for agglutination tests. Felix and Bhatnagar 4 reported that formalized suspensions retained their agglutinability by Vi antiserum and their agglutinogenic properties. Serums prepared with formalized suspensions were, however, inferior in protective antibodies to serums prepared with living organisms. They also found that phenolized suspensions progressively lost their agglutinability by Vi antiserum and serums produced with such suspensions contained no Vi agglutinins and were devoid of protective antibodies. Felix and Pitt 5 found that alcohol-treated suspensions retained their agglutinogenic and agglutinin-binding properties but that their agglutinability by Vi serums was “almost annulled or at least very much reduced.” Felix and Petrie 6 also stated that alcohol treatment almost annulled the Vi agglutinability. All the workers cited above observed that as the agglutinability of the bacilli by Vi antiserums disappeared they progressively became more agglutinate by O antiserums.

Since the observations of the writer were not in full accord with the descriptions of the characteristics of Vi antigen, particularly as regards its susceptibility to heat and alcohol, a systematic study of influence of temperature and certain chemicals on the substance was undertaken. The Watson strain of S. typhi was used because of the constancy of its content of Vi antigen. Additional experiments with other strains of S. typhi gave comparable results.

In the course of experiments on the functional deplantation of brain fragments into the dorsal fin of urodele amphibian larvae described in earlier communications, 1 a striking local pigmentation effect was observed, whenever thalamic grafts were used.

Donors and hosts were larvae of Amblystoma tigrinum, between 3 and 4 cm in length. The brain part which produced positive effects is shown as shaded area in Fig. 1. One-half of this portion, either with or without an adjacent slice of midbrain, was inserted into the gelatinous connective tissue of the fin. The grafts were positively free of hypophyseal and adjoining infundibular tissue.

Within a few weeks after the implantation, the vicinity of the grafts turned deep black (Fig. 2), indicating the deposition of vast amounts of newly formed melanin. The host chromatophores were not appreciably affected. Microscopically, the new pigment appears in two forms: (a) as granules inside of richly arborized cells, which give the appearance of hypertrophied chromatophores and which are found both in the interior and along the surface of the grafts; (b) as large compact clumps interspersed among the epidermis cells of the overlying skin (Fig. 4).

Whether the melanotic cells are all of metaplastic thalamic origin, or whether some surrounding host cells have likewise been induced to form pigment, has not yet been determined. However, the fact that deplants into animals which had been deprived of their hypophysis in the embryonic stage and were consequently very lightly pigmented, gave rise to local pigment clusters, points to the graft as the main source of the melanotic cells. Whether the large intercellular pigment clumps of the host epidermis arise as diffuse interstitial pigment deposits, or represent residues of degenerated chromatophores with excessive pigment content, remains to be seen.

A method for obtaining an accurate mixed sample of the total inspired air is described. Provision is made for control of the size of the sample and the rate of sampling so that they conform to the inspired air of the subject.

The CO₂ percentage of the inspired air in a mask is more reliably obtained through this method than through alveolar CO₂ samples, since the volume of ventilation tends to keep the CO₂ tension constant. Alveolar samples taken at low barometric pressures, such as 140 mm Hg, are compressed to such a small volume at sea level that analysis may be difficult. Such difficulty is not experienced when taking large inspired air samples for analysis.

The spectacle eye syndrome in rats has been produced very consistently by the inclusion of egg white in a synthetic diet which allows good growth in the absence of egg white. Pantothenic acid at levels up to 100 γ per day does not prevent the onset of this condition. Corn oil and pyridoxine or the combination of the two are without effect. Inositol has neither a preventative nor a curative action under these conditions. A biotin concentrate at a level of 2γ of biotin per day is specific for the prevention and cure of this syndrome. The cure is first noticeable after 5 days and complete restoration of the hair results after 2-3 weeks of treatment. A definite weight gain is noted with rats receiving the biotin concentrates.

The Sullivan colorimetric method can be applied satisfactorily to hydrolysates of tobacco mosaic virus if humin formation is inhibited by hydrolyzing with hydrochloric acid-titanous chloride, or better with hydriodic acid.

It has been reported 1 on the basis of a single test that nicotinuric acid has a curative action in canine blacktongue, and reference has been made to the “antipellagra value” of nicotinuric acid in a recent review. 2

We have tested the curative activity of a specimen of nicotinuric acid prepared from glycine ethyl ester and nicotinoyl-chloride by the procedure of Meyer and Graf 3 ; melting point 240-41° (Meyer and Graf found 237-8°), neutral equivalent 184 (theoretical 182.7).

The arrangement of the test and basal diet were as previously described. 4 Four dogs were used. With the first 2 dogs curative tests were made by our standard procedure, with daily subcutaneous doses of 6 mg and 8 mg respectively per kg body weight for 5 days. The results were negative. In a third dog given 6 mg per kg a partial cure was obtained, and subsequently a preventive dose of 1 mg per kg daily was given, and the dog declined and died during this treatment. The fourth dog was given 3 mg per kg daily and was completely cured except that its normal weight was not fully restored. The dosing was continued for 60 days, during which time the dog remained healthy. Ten days after the last dose it began to decline rapidly and after 7 days more it died of severe blacktongue. These effects may be contrasted with those due to nicotinic acid itself. In our curative method a daily dose of 1 mg per kg for 5 days produces optimum response; and on basal diets of this type the daily dose needed for prevention of blacktongue is about 0.1 mg per kg. 5

Our studies indicate that it is difficult to secure cerebral infection when the virus of St. Louis encephalitis is introduced into the intestinal tract. Nevertheless one definite infection did occur after intraintestinal inoculation. We feel the experimental procedure ruled out the nasal route of infection. Some degree of humoral immunity was produced in mice both by intragastric and intraintestinal inoculation. Only two animals survived the subsequent intracerebral injection of 100 lethal doses of virus, showing that only rarely is adequate protection against infection provided by intragastric or intraintestinal virus inoculations.

Three races of bacteriophages have been isolated. which attack the H antigens of 2 strains of Salmonella poona. Two races of phage have been isolated which are able to attack the H antigen of E. typhi. This finding is another example of the selective activity of bacteriophages which is directed particularly against the non-somatic portions of the bacterial cell.

During the last few years we have been interested in the mechanism whereby the subcutaneous injection of various substances such as xanthine, sodium ricinoleate, etc., increases a rat's resistance to the poisonous action of carbon tetrachloride or chloroform. During the course of this investigation, we were led to try the possible effect of oral administration of sulfanilamide on the animal's resistance to carbon tetrachloride. To our considerable surprise, it was found to reduce the mortality rate very markedly. Later experiments confirmed this finding and showed that orally administered sulfanilamide exerted a definite protective action against liver necrosis from acute carbon tetrachloride poisoning.

Experimental. Male and female rats, weighing from 200 to 300 g were used. In the individual experiments animals of the same sex and of approximately the same weight were used for control and treated animals. In the experiments recorded in Table I, the sulfonamide drugs were given by stomach tube in doses of 30 mg per 100 g of body weight. Two doses, one 20 hours, the other 3 hours before the time of acute poisoning, were administered. A few preliminary experiments were carried out with sulfanilamide in doses of 10 and 15 mg per 100 g of body weight. The degree of protection was apparently less than that with the higher doses, consequently the other drugs were not studied at the lower levels. The method of anesthesia was the same as described in a previous article. 1 In the experiments recorded in Table I, mortality alone has been considered as the evidence of protection. Similar experiments, however, have been carried out, involving 18 controls and 22 sulfanilamide-treated animals, in which the duration of anesthesia was reduced so that most of the control animals survived.

Chronic ulcerative cecitis, as it developed spontaneously in a rat colony, presented itself as an ideal experimental disease in which to study the effect of chemotherapy. At the time of the present observations the majority of the animals in our colony developed lesions of “cecitis” by the time they had reached 300+ g in weight. The addition of 0.5% of sulfaguanidine to the diet produced no deleterious clinical effect nor any visible gross lesions. On the contrary rats on sulfaguanidine gained weight rapidly. The drug even in the small doses used had a striking prophylactic effect against the development of cecitis; not only was the incidence very much lower than in the control group but, even more impressive, such lesions as occurred were minimal in contrast to the advanced disease found in most of the untreated rats. The protective effect of sulfaguanidine is demonstrated further by the failure of the treated animals to lose weight as did the controls with progressive lesions.

The concentration of the drug in the stools was not measured but the relatively low blood levels suggest, as pointed out by Marshall 4 that sulfaguanidine is less readily absorbed than some of the other sulfonamides.

In clinical work on ulcerative colitis, dysentery and other bowel infections in man we have not always been impressed with the therapeutic effects of sulfaguanidine. It is possible, however, that the drug may be of greater value as a prophylactic, and the present experiments suggest that such is the case. Trials in man under proper conditions would seem worth while in connection with military establishments.

Malarial infection (P. lophurae) of the young Peking duck usually progresses with rapid multiplication of the parasites in the blood and death after 5-16 days 10 (7-10 days in our series). If sulfonamides are administered by incorporation in the food, the multiplication of parasites is checked after a few days and the birds survive at least several weeks with relatively few or, occasionally, no parasites in the blood (sulfathiazole or sulfadiazine). Sulfanilamide appears to be less effective.

(1) Angiotonin is inactivated following incubation with renal extracts. This destruction does not occur by oxidative deaminization since (a) oxygen is not necessary for the reaction, (b) a fraction of kidney extract can be prepared which destroys angiotonin but fails to inactivate hydroxytyramine, and (c) angiotonin is destroyed in the presence of octyl alcohol. (2) Evidence is presented for the existence of an aerobic polyphenolase in kidney extracts, capable of destroying specific pressor amines.

Previous observations that a dietary deficiency disease, produced in foxes by feeding raw fish, is fundamentally a B₁ avitaminosis, have been confirmed in the chick. The additional observation has been made that this condition can be reproduced in foxes which have recovered from a previous attack. Evidence obtained from experimentation in vitro confirms the observation previously made in vivo that the inactivation of vitamin B₁ by raw carp occurs within the feed mixture itself. The level of inactivation depends upon the length of time that the fish is in contact with the feed mixture. Studies to standardize the conditions of the reaction are now in progress. Present evidence indicates that the reaction may be enzymatic in nature.