Experimental Biology and Medicine

Data have been presented on the survival of the albino rat receiving radiation from internally administered P³² and colloidal Au¹⁹⁸. These isotopes have been administered singly and in combination. The data clearly indicate that P³² and colloidal Au¹⁹⁸ when administered in combination act synergistically in their killing effect. This appears to be related to the simultaneous injury of the reticuloendothelial system and the blood-forming tissues.

The Mo agglutinin (a human agglutinin for mouse erythrocytes) was found to be present in 400 human sera tested. The failure of previous attempts to demonstrate the agglutinin in all sera was probably due to the fact that the method used was not sufficiently sensitive. Merthiolate has little or no inactivating effect on the Mo agglutinin. The significance of the variation in amount of Mo antibody in human sera has not been determined.

MM virus multiplied extensively in 9 serial passages in mouse testicular tissue in vitro and in 4 serial passages in human testicular tissue in vitro. Fluid from the last tissue of each series represented a 10-13 dilution of original inoculum. These experiments do not exclude the possibility that the virus may have multiplied in the very minute amounts of muscle tissue present in the cultures. The virus multiplied more slowly and persisted longer in human tissue than in mouse tissue.

1. A modification of Minibeck's method was found to be satisfactory for the determination of cholic acid and glycocholic acid added to serum. 2. In healthy dogs when bromsulphthalein and sodium cholate were injected together, the concentration of bromsulphthalein in the serum was greatly elevated five and fifteen minutes after administration. The cholate concentration, however, was normal. 3. In early central necrosis of the liver produced by carbon tetrachloride, the bromsulphthalein excretion was definitely delayed while the cholate excretion was only slightly changed. The bromsulphthalein test appeared to be more sensitive in detecting early hepatic damage. During the first thirty minutes the bromsulphthalein retention in the combined test paralleled roughly the retention when bromsulphthalein was given alone, but was 35-60% higher.

The iron content of intestinal lymph of rats maintained on a normal diet is relatively constant over periods as long as seven days. At lymph outputs of one ml per hour, there is an hourly output of 0.5 γ of iron. With a 3- to 4-fold increase of lymph volume, iron concentration falls off and total output remains less than 1.0 γ per hour. The iron present in lymph is non-dialyzable at pH 7.0 to 4.7, but is dialyzable at pH 1.5. Added iron, up to concentrations of 48 γ per 100 ml in 2 specimens of pooled lymph, was non-dialyzable at pH 7, but all added iron in excess of this concentration was dialyzable.

Nine patients who received aureomycin, 9 patients who received chloramphenicol, 7 patients who received streptomycin and 6 patients who received terramycin failed to show any influence of p-(di-n-propylsulfamyl)-benzoic acid, ‘Benemid’, administered orally every 6 hours in a dose of 0.5 g on the plasma concentrations of the respective antibiotic agents. The failure of ‘Benemid’ to increase the plasma concentrations of streptomycin indicates that ‘Benemid’ may be administered safely to patients who are receiving streptomycin in conjunction with PAS.

1. The direct eosinophile counts of the majority of a group of 17 psychotic patients rose sharply during the course of massive combined testosterone-estrogen therapy. 2. There was an apparent positive correlation between improvement in the patients' clinical status and the degree of eosinophilia attained. 3. An anti-adreno-cortical effect at least in relation to blood eosinophile levels of sex steroids is suggested.

The calcium specific activities of the femoral epiphyses, femoral diaphyses, humeri, lumbar vertebrae and the remainder of the skeleton of large rats differ soon after the administration of radiocalcium but decrease to a common value after 52 days, following which the specific activities decline at equal but much reduced rates. The fraction of the injected dose of radiocalcium retained in the animals declines to 42-45% on the 52nd day, after which only small quantities of radiocalcium are excreted. The results indicate the existence in large rats of two kinds of skeletal calcium which differ markedly in their rate of turnover and in the lenght of time over which they fix radiocalcium. The apparent reduction in skeletal calcium specific activity occurring in large rats after the 52nd day following the injection of radiocalcium is due to accretion of calcium to the skeleton. Part of the decline in skeletal specific activities which takes place in rats before radiocalcium excretion ceases is also due to skeletal growth.

Data as to the changes of calcium specific activity of the urine and the teeth following the injection of labelled calcium are presented and discussed.

The plasma levels for nonprotein nitrogen and amino nitrogen after administration of glycine were higher in vit. B₁₂-deficient chicks than in B₁₂-injected chicks. One gram of glycine, when force fed in gelatin capsules, was toxic to starved, B₁₂-deficient chicks and less toxic to B12-deficient chicks which had not been starved. Chicks which had been injected with vit. B₁₂ were able to withstand the glycine whether or not they had been without food.

1. Lecithin and cephalin are capable of neutralizing the inhibiting properties of lupulone. 2. Evidence is presented indicating that the antagonistic effect of serum on the bacteriostatic action of lupulone is due, at least in part, to its phosphatide content. 3. The inhibition of respiration by lupulone may be reversed by the subsequent addition of plasma.

The authors wish to thank Elizabeth A. McComb of this laboratory for the determinations of phosphorus.

1. The anti-hyaluronidase titre of the normal human serum has been determined by the means of the viscosimetric method.

2. The anti-hyaluronidase titre is the same for both sexes between the ages of 21 and 30 years (32.0%). Between the ages of 31 and 60 years the titre in the serum from the normal female (38.0%), is significantly higher than that of the male (28.2%).

The bull testicular hyaluronidase was furnished through the kindness of Dr. Irwin C. Winters, Director of Research, G. D. Searle and Co.

(1) The anti-hyaluronidase titre of the blood of patients with lymphosarcoma, Hodgkin's Disease, and leukemia has been determined by means of the viscosi-metric method. (2) The anti-hyaluronidase titre is elevated in all 3 conditions and varies with the clinical condition of the patient. (3) Cortisone causes an exacerbation of the disease in myelocytic leukemia with a corresponding increase in the anti-hyaluronidase titre. (4) In lymphocytic leukemia and Hodgkin's disease, cortisone, ACTH and other forms of therapy cause a decrease in the anti-hyaluronidase titre corresponding with clinical improvement. (5) There is no apparent relationship between the degree of invasion of the blood stream and the bone mar-row picture and the changes in anti-hyaluronidase titre appears to be related to the quantity of tumor tissue rather than to its invasiveness.

Heinz bodies have been demonstrated in the blood of monkeys following the oral administration of phenylhydrazine hydrochloride. These bodies disappear from the circulating blood in normal monkeys more rapidly than they do from the blood of splenectomized animals. A quantitative method for determining the number of Heinz bodies has been described. This method is based upon the observation that Heinz bodies are not hemolysed in distilled water. A comparative study is made of the number of Heinz bodies free in the plasma in blood smears stained with a combination of Wright's and Giemsa's stains with those remaining after treatment with distilled water. The latter technic is both simple and rapid.

A procedure has been described for the isolation of adenosine triphosphate from barium-nitric acid insoluble residues prepared from whelk foot muscle and rabbit striated muscle. The ATP so isolated is in-distinguishable physiologically from ATP prepared according to the standard procedure of Needham but is only slightly soluble in strong acid. It is present in the smooth muscle of the whelk in much larger amounts than in striated rabbit muscle. Treatment of a similar residue from beef heart yielded a compound which chemically and physiologically resembled ADP.

The intravenous administration of 1.2 mg of digitoxin to 5 male subjects with no cardiovascular disorder was found to cause a significant decrease in the serum protein concentration and an increase in the total circulating protein content within 8 hours. The results were interpreted as indicating an increase in the water and protein content of the vascular compartment.

A study of the xanthine oxidases in selected tissue homogenates from different species showed that the enzymes present in bird tissues was a dehydrogenase rather than an oxidase, since the aerobic activity of the enzyme was negligible in comparison with its activity in the presence of methylene blue. The enzyme present in mammalian tissues was an oxidase whose aerobic activity could generally be increased from 1.5 to 2.5 times by the addition of methylene blue to the aerobic test system. In all cases the aerobic activity of the xanthine oxidase was inhibited from 40 to 100% by antabuse. and this inhibition was completely overcome by the addition of methylene blue. Heating the tissue homogenate at 56° for 30 minutes gave decreased aerobic xanthine oxidase activities with rat and mouse liver but no change with most mammalian tissues; the antabuse inhibition was eliminated to varying degrees with different tissues. The dehydrogenase enzyme or the dehydrogenase portion of the mammalian xanthine oxidase complex was unaffected by antabuse or by the heating procedure, since the activity in the presence of methylene blue remained constant irrespective of what happened to the aerobic activity.

Albino rats give a demonstrable reactin of redness, swelling of loose tissue, pruritis and stupor, when injected with doses of Dextran comparable to recommended doses for humans. Three different lots of Dextran gave the same reactions. Fractions of varying mean molecular weight all vave prompt reactions when administered intravenously. The delay in reaction following intraperitoneal injection may be related to the time required for the Dextran to enter the general circulation in sufficient quantity. The larger molecules pass more slowly into the circulating blood. Dextran reactions in rats following injections on subsequent days are diminished.

The influence of prolonged light surgical anesthesia with sodium pentobarbital on the renal tubular sodium reabsorptive ability was investigated in dogs initially given 50 cc per kg of isotonic saline by stomach tube. During time intervals averaging 5 hours, the tubules continued to reabsorb an average of 98.75% of the filtered load. The conclusion is reached that this anesthetic agent has a negligible effect on sodium reabsorption.

The yolk sac of the developing chick embryo has proved to be highly suitable for the propagation of the following pathogenic fungi: Actinomyces bovis, Nocar-dia asteroides, Nocardia intracellulars, Sporotrichum Schenkii, Histoplasma capsulatum, Cryptococcus neojormans and Coccidioides immitis. This method promises to be of great value for the experimental study of these mycotic infectins. It is quite likely that many other of the pathogenic as well as non-pathogenic fungi may be studied with profit by infection of the yolk sac of chick embryos.

(1) Positive Prausnitz-Küstner reactions were consistently demonstrated in volunteers passively sensitized with sera from 2 hypersensitive donors treated with cortisone. (2) Positive Prausnitz-Küstner reactions were similarly demonstrated in cortisone treated volunteers passively sensitized with sera of the cortisone treated donors. (3) There was no significant difference in the Prausnitz-Küstner reactions of those volunteers tested before and during treatment with cortisone. (4) It may be concluded that under the conditions of the experiments described, cortisone does not influence passively induced skin hypersensitivity in man.

The amount of vit. B₁₂ in the liver, spleen and heart of 28-day-old rats was approximately doubled when a source of vit. B₁₂ was added to the diet of the mothers. The diet of the mother had no important effect on the vit. B₁₂ content of the kidney. In general the kidney and spleen contained slightly more vit. B₁₂ than liver. The heart contained a relatively small amount of vit. B₁₂ in comparison to other tissues.

1. A method for recording of infra red spectra from frozen tissue section of 25-50 μ thickness and from areas as small as 3 × 3 mm is described. 2. The infra red spectra of tissues show a fingerprint region which is so characteristic of the individual organ that it was frequently possible to identify the tissue from its infra red spectrum. 3. The assignment of tissue spectra to chemical structures as nucleic acid derivatives has been discussed. 4. A method for quantitative infra red spectroscopy in brain tissue has been described. 5. Significant spectroscopic changes in brain tissue of animals in insulin shock have been demonstrated.

When unfixed skin collagen, which ordinarily is only lightly orthochromatic, is treated with pepsin it becomes metachromatic. Trypsin does not have this effect. Collagen denatured by alcohol or formalin fixation is rendered metachromatic by both pepsin and trypsin.

1. Both ACTH and Cortisone therapy depress the gamma globulin and fibrinogen levels in the blood of patients with active rheumatoid arthritis and scleroderma.

2. Changes in these 2 blood proteins are responsible for the observed changes in the sedimentation rate.

3. At the present state of our knowledge, the sedimentation rate cannot be used as an index of the effectiveness of hormone therapy on the active disease process.

Excision of the pancreatic duct together with a duodenal flap surrounding its papilla is followed in the majority of dogs by extensive intraperitoneal and marked intrathoracic fat necrosis, and usually leads to the death of the dog on the 3rd or 4th postoperative day. This appears to be the most reliable procedure for producing fat necrosis in the dog.

1. The distribution and excretion of radioactive hafniurri¹⁸¹ sodium mandelate after its intravenous administration was studied in 17 rats sacrificed at intervals of 1, 2,3,4,8, and 16 days. 2. Seventy to 90% of the total activity was retained in the liver, spleen, the skeletal, muscular, and integumentary (pelt) systems. 3. Specific activities showed the spleen to be highest, followed by the liver, bone, and kidneys. 4. The adrenals, thyroid, pancreas, salivary glands, and testes showed a slight, but appreciable retention. 5. Hafnium in the blood was found chiefly (95 %) in the plasma and remained in appreciable amounts to 4 days. 6. Seven per cent of the total dose was excreted in 16 days with more being eliminated in the urine than in the feces, the urine/feces ratio being 2.4.

1. A flavonoid (vit. “P”) compound is of no value in the treatment of radiation injury in the LD₆₀ to LD₁₀₀ range in mice.

The effect of feeding crystalline aureomycin hydrochloride on digestion and nitrogen retention was determined in balance trials with six steers. Feeding 0.2 g aureomycin daily caused a marked reduction in the digestibility of crude fiber. It also reduced the digestibility of dry matter and of nitrogen free extract. When 0.6 g of aureomycin was fed daily to steers, it produced a marked anorexia and a fetid diarrhea within 48 to 72 hours. This condition persisted for several days after the aureomycin feeding was discontinued. Continued feeding of 0.2 g aureomycin daily, produced somewhat milder digestive disturbances.

1. Treatment with cortisone overcame the beneficial effect of vaccination in mice infected with a highly virulent strain of M. tuberculosis, human type, but did not significantly enhance the lethality in non-vaccinated mice. 2. Treatment with cortisone increased the susceptibility of mice to infection with M. tuberculosis of reduced virulence.

A chromatographic examination was made of the free amino acids of tissues of normal and cortisone-injected chick embryos. The content of free hydroxyproline was increased markedly in the tissues of the cortisone-treated embryos. The results were confirmed by a colorimetric procedure. With the exception of glycine, in which increases were noted in some instances, the other amino acids showed no consistent changes as a result of the injection of cortisone. The injection of Δ 1 -17 α-hydroxy progesterone produced slight decreases in free hydroxyproline content.

A study has been made of the absorption and excretion of viomycin following intramuscular administration in humans. Maximum serum concentrations of 82 to 125 μg per ml were attained within 2 hours after a single dose of 25 to 50 mg per kilo. Reasonably high concentrations were achieved in the serum of patients receiving daily maintenance doses of the drug. Small concentrations of viomycin, 10 to 12.5 μg per ml, were detected in the cerebrospinal fluid in the presence of high serum concentrations of the drug, 100 to 125 |mUg per ml. Viomycin was excreted in the urine in high concentrations, and from 65 to 100% of the administered dose was recovered in the urine within 24 hours.

In the course of some studies with vit. E-deficient rats, unusual abnormalities of the eye were observed in the young of mothers deficient in this vitamin. Such lesions had not been encountered before in this laboratory, and have not been mentioned by other investigators to our knowledge.

Although the data are limited, it seems of importance to report them, in view of the recently published studies of Owens and Owens(1) indicating that vitamin E may play an important role in the prophylaxis of retrolental fibroplasia, a disorder which appears frequently during the early months of life in small, prematurely born infants. This condition has been recognized for many years, and has been ascribed to a variety of etio logical factors; however, Owens and Owens (2) are the first investigators to follow the progress of the disease from the initial stages of dilatation of the retinal arteries and formation of fibrous bands extending into the vitreous to the final fusing of these bands with folds of the swollen retina to form the characteristic membrane behind the lens. The membrane may be complete, causing total blindness or it may be partial, allowing some vision to be retained. Symptoms accompanying this condition noted by these and other workers (3) were eyeballs smaller than normal and hemorrhages behind the lens. Once the changes occur, they are irreversible, but Owens and Owens have been successful in preventing their appearance almost entirely in a series of premature infants by the administration of dl alpha tocopheryl acetate, starting soon after birth.

In our experiments, female rats that had had access to a vit. E-deficient diet∗ from either 7 or 14 days of age, and had been weaned at 21 days to the same deficient diet, were mated with normal males as soon as the vagina was patent and regular oestrus cycles had been established.

An action of dilantin and mesantoin on the nerve fiber is described. The addition of these compounds to a perfusion of artificial sea water does not affect the electrical activity of isolated giant axons. In the presence of reduced calcium and magnesium spontaneous firing of the fiber occurs. This may be reversed by returning the nerve to sea water with normal concentrations of calcium and magnesium. A decrease in hyperirritability may also be obtained by adding dilantin or mesantoin to water deficient in calcium and magnesium. Continued exposure to the latter solution reversibly abolishes signs of electrical activity. Dilantin labelled with N¹⁵ was found to penetrate into the interior of the giant axon of squid. The concentration in the axoplasm of the fiber was close to equilibrium within one hour.

The effects of histamine and a large number of antihistaminic drugs upon the coagulation of normal and heparinized rabbit plasma have been investigated. It has been established that the amount of each compound required for an antiheparin effect is critical. At concentrations below the critical level the drugs have little or no effect upon the coagulation system studied. At concentrations above this level several of the antihistaminics as well as histamine produced a progressively increased incoagulability of the system. This anticoagulant effect is related to concentration and the action is on some substance other than heparin. Thenfadil, methapyrilene and thonzylamine had no effect upon normal or heparinized plasma. Of all the compounds tested, 194-B, methaphenilene, pyranisamine, 204, phenazoline, tripelennamine, diphenhydramine, pyrathiazine, P.D. AH-853 and p-Fluorobenzyl D.P.E. gave the best results in that, upon reaching the critical concentration for heparin inactivation, they did not become anticoagulants themselves. It has been postulated that the antiheparin activity of these compounds is due to their direct combination with heparin.

The effects of early transection and mechanical obstruction of the optic nerve in the chick embryo were studied. The deflected fibers follow abnormal courses determined by the surrounding connective tissue matrix without evidence of neurotropic attraction by the brain.

Simultaneous sera glucuronidase, and esterase determinations have been carried out on the blood samples of 37 post-age 50 healthy control subjects (17 males and 20 females), 11 patients with advanced breast cancer and not on hormone therapy, and on 12 patients with advanced breast cancer receiving estrogen therapy. It was found that the control male subjects had both a higher serum glucuronidase and serum esterase than did the control female subjects. An inverse relationship was found for the changes in sera activity levels of glucuronidase and esterase in the patients with breast cancer subjected to variations in estrogen therapy.

(a) A mold, a species of Tilachlidium, was found to produce a water soluble antibiotic, synnematin, which was partially purified, (b) Crude preparations inhibit in vitro certain species of Brucella, Corynebacterium, Micrococcus, Streptococcus, all species of Salmonella tested and some species of Shigella. Synnematin is inactive against the tested strains of Aerobacter, Escherichia, Mycobacterium, filamentous molds and most species of Shigella, (c) In vivo activity is demonstrated by the ability of synnematin to protect mice against infection with D. pneumoniae and to protect egg embryos against infection with S. pullorum. (d) Its low toxicity and other properties are reported.

Comparison of 204 consecutive weekly lots of BCG vaccine prepared under standardized conditions were found to be satisfactorily uniform in the number of viable organisms and clumps of organisms they contained. The survival rate of BCG vaccine stored at 2-4°C has been determined.

(1) Newborn mice may be infected by oral administration of at least 5 different strains, representing 4 immunologically distinct Coxsackie, or C, viruses. Adult mice were resistant. (2) Newborn mice surviving oral administration may produce neutralizing antibodies. (3) Adult female mice fed C virus did not transmit neutralizing antibodies to their offspring, in contrast to females inoculated parenterally. (4) In a comparison of routes of inoculation of newborn mice it was found that higher titers may be reached by subcutaneous than by oral administration. The subcutaneous route proved to be about 10,000 times more sensitive than the oral route. (5) Direct contact between inoculated and uninoculated mice did not result in the transmission of infection.

Recent studies (1-5) of brain stem mechanisms and their influences upon the electrical activity of the cortex have suggested the desirability of recording cortical and diencephalic electrical activity in normal, unanesthetized cats during states of sleep and wakefulness. In order to record from or stimulate deep structures of the brain, a method of permanently implanting electrodes has been developed along the lines begun by Harris(6) and Hunter and Jasper(7). The possibility of wider application of this technic leads to detailed description here.

A permanently implanted electrode system for this purpose must meet three major requirements. It must be capable of precise placement or localization in order to explore systematically the matrix of small nuclei in the subcortical regions of the brain. It must be sufficiently durable to maintain electrical insulation in the presence of tissue fluids. It should not produce undue tissue reactions and irritability. A simple extension of the principles of stereotaxy permits accuracy of placement and satisfies the first criterion. Durability and non-irritability have been achieved by the proper selection of materials. Previous methods of implanting electrodes have used the Horsley-Clarke instrument for orienting the electrodes which are fixed into position by cementing them to sockets screwed into the calvarium. In the present method a new horizontal reference plane is established by attaching a flat base plate to the cranium parallel to the original Horsley-Clarke H (horizontal) reference plane. A second plate carrying the electrodes at predetermined H and L-R (left-right) positions is brought into place with the Horsley-Clarke instrument and cemented permanently to the base plate. In this manner several electrodes may be placed accurately to varying depths over a wide area.

Materials and procedures. The following sections describe in detail the construction of the various parts and sub-assemblies in this order.

In a group of Swiss albino mice injected with cortisone acetate it was found that 8 hours post injection the spleens contained a significant increase in the number of eosinophilic leucocytes. It is postulated that this may be the locale of the eosinophilic leucocytes during their disappearance from the circulating blood following adrenal cortical stimulation. The number of eosinophilic leucocytes found in the spleen could account for the number that disappeared from the circulating blood following a single injection of cortisone acetate.

The progressive depletion of ascorbic acid previously reported to occur in the adrenals of female mice carrying a transplantable sarcoma has not been confirmed in the case of male mice of another strain bearing a transplantable lymphosarcoma. A pronounced sex difference exists in the adrenal ascorbic acid response of CBA mice to histamine and ACTH, although relatively constant total quantities of ascorbic acid may disappear from the glands of each sex following similar stimuli.

1. As compared to pair fed controls, guinea pigs on a vit. C free diet showed no obvious differences in blood pressure or in ability to respond in pressure manner to intravenous or intra-arterial injections of epinephrine at the doses employed. 2. The animals were bled by a standard procedure of hemorrhage. Avitaminosis C was accompanied by a significant reduction in the survival time, in resistance to anesthesia, and in the ability to withstand comparable amounts of blood loss. In addition, all deficient animals, with one exception, were unable to elaborate renal VEM as determined by rat assays of the plasma. 3. The significance of these observations is discussed. The suggestion is offered, in relation to earlier findings, that the larger arterioles with undiminished constrictor responses to epinephrine in avitaminosis C may function primarily in maintaining normotension and in producing the vasoconstrictor component of acute pressor reactions. The smaller, terminal arterioles, with greatly diminished epinephrine reactivity during vitamin C deficiency, may act chiefly in the pressor mechanism to supplement the larger vessels in acute stress states and during prolonged attempts at blood pressure elevation.

Two methods for the preparation of a stable non-infective soluble influenza A antigen have been developed. One is based on treatment with 2% hydrogen peroxide, the other on treatment with 0.1% formaldehyde followed by its neutralization prior to storage or lyophilization.

The in vitro cultivation of the parasitic phase of C. immitis is reported and the composition of the medium detailed. Sporangia were formed by all strains studied though in varying numbers and after varying periods of incubation. Mature culture-grown sporangia were indistinguishable from mature tissue sporangia.

Experiments on dogs have revealed the existence of a chemoreceptor trigger zone for emesis which is quite distinct from the vomiting center. This zone is a bilateral structure situated at the surface of the medulla oblongata in the dorsal region of the ala cinerea. Destruction of the emetic chemoreceptor zone results in animals which are permanently refractory to apomorphine given by vein, but it does not impair the vomiting response to orally administered copper sulfate. Eight out of 9 such dogs failed to vomit when tested intravenously with known emetic doses of the cardiac glycosides, lanatoside C, scillaren A and ouabain. Only one vomiting response was elicited; in this case, the latent period was greatly prolonged, a fact which suggests the existence of another site of emetic action of digitalis glycosides. The significance of a central chemoreceptor trigger zone for the emetic action of digitalis is discussed.

Bilateral renal decapsulation, performed one week after an acute episode of ‘hemorrhagic kidneys’ in choline deficient rats, prevents the development of hypertension in such animals and restores blood pressure to normal when the operation is performed in rats in which such hypertension is already established. Administration of ACTH to such renal decapsulated rats restores their hypertension but is essentially without effect on the pressures of normal rats, hypertensive rats, or renal decapsulated rats which never were choline deficient.

A microbiological method for the quantitative determination of biotin is described. Allescheria boydii 1699 is used as test organism. The reliability of the method is indicated by the reproducibility of assays and good recoveries of the biotin added to various samples. The method is sensitive, the assay range being 1 to 100 m/μg of biotin.

Uremia was produced in dogs by intravenous administration of varying doses of sodium tetrathionate. The findings of Gilman et al.(l) cited above were confirmed. In addition, it was shown tthat renal lesions resulting from tetrathionate administration, heretofore not described in detail, involve the distal convoluted and collecting, as well as the previously mentioned (1) proximal renal tubules. The resulting uremia may be rapidly fatal or continue 20 or more days, and is accompanied by non-hyperglycemic urinary reducing substances and lowered CO₂CP and SpG of the urine.

The ability of neopyrithiamine to inhibit growth of Microsporum audouini in vitro in very low concentrations suggests its use in cases of tinea capitis caused by this fungus. The application of neopyrithiamine alone or in combination with other agents or vitamin antagonists now being studied may prove helpful in combating these infections.

After female rats, on a diet that contained soybean oil meal as a source of protein, became depleted of the factor that prevents hydrocephalus, the incidence of the abnormality among the offspring was 28%. The addition of a vit. B₁₂ concentrate to the diet or the injection of crystalline vit. B₁₂ in the dams during the early stages of gestation prevented the abnormality in the young animals and increased their viability. Hydrocephalus was not prevented by folic acid alone, but it has not been determined whether vit. B₁₂ alone is effective or whether both folic acid and vit. B₁₂ are required.

Administration of ACTH caused chromatolysis in the cells of the paraventricular hypothalamic nucleus. Cortisone affected this nucleus but induced more widespread chromatolysis and vacuolation of thalamic and hypothalamic nerve cells.

A relatively simple technic for the intraspinal inoculation of mice which lends itself to routine laboratory use has been described. For Lansing poliomyelitis virus, it seems to be a more sensitive method of detecting virus than the intracerebral technic. The quantitation of virus titers by this method is consistent between two different technicians and on repeated tests by one technician from any one set of virus dilutions. It can be applied to the routine testing of serums for Lansing antibodies. The chief advantage of the technic is the marked shortening of the incubation period of Lansing infection in mice as com-1 pared to that following intracerebral inoculation.

The excised crayfish ventral nerve cord exposed to ultrasound (35 watts/ cm2, frequency 1 mc) exhibited a reduction of spontaneous activity after several seconds exposure and recovered its original activity about one minute after the ultrasound was turned off. Frogs positioned so that ultrasound was incident on the dorsal surface over the lumbar enlargement of the spinal cord exhibited paralysis of the hind legs after 4.3 sec. exposure (at room temperature) and exhibited paralysis after 7.3 sec. exposure (at 1°-2°C). Histological examination of the sciatic nerves showed extensive degeneration of nerves and examination of the spinal cord indicated destruction of the lower motor neurones. It was concluded that the effect of ultrasound on the systems studied is produced by physical factors other than temperature.

1. Citrovorum factor, in amounts of 5 to 10 million units daily intramuscularly, has been shown to produce adequate hematologic and clinical response in 4 of 6 patients with Addisonian pernicious anemia, and a submaximal response in another. A 6th patient failed to respond altogether. 2. Local marrow instillation of citrovorum factor failed to produce enhanced maturation of megaloblasts in situ. 3. Citrovorum factor has been found to be more effective than pteroylglutamic acid in reversing aminopterin inhibition in patients with pernicious anemia.

Since the development by Cannon and his associates ( 1 , 2 ), of the use of the hypoproteinemic rat in studies on the dietary utilization of proteins and of amino acids, the general technic has been employed in many laboratories for assaying the plasma protein-regenerating ability of proteins and of amino acid mixtures. However, the method has the disadvantage that a relatively long time, usually about 3 months, is required for the preparation of the animals for purposes of assay. In view of the accelerating effects of thyroid hormone on protein metabolism, which have been well described by various investigators( 3 ), the feeding of one of the thyroactive substances, such as an iodinated protein, would appear to be a useful means of speeding up the depletion process in the preparation of test rats. Data presented here were obtained from some preliminary and exploratory trials made to test this possibility and indicate that the use of iodinated casein for this purpose is practical.

Observations were made on the changes in plasma proteins in rats fed for different periods of time on a basal low-protein diet and in rats fed the same basal diet supplemented with 0.1% and 0.15% of iodinated casein.∗ Further observations were made after a period of repletion, on one of the groups of animals which had been depleted with iodinated casein. Male albino rats of approximately 200 g weight were used in all groups. The animals were housed individually and fed the diets ad libitum. The diets used are indicated in Table I. The iodinated casein added to diets 2 and 3 was mixed directly with the other ingredients. Blood samples of 0.3 to 0.4 ml amounts were obtained from the rats by heart puncture and mixed with a small amount of purified heparin.

The cardiac activity of bufalin, cinobufotalin, telocinobufagin and cinobufagin has been compared. They all have a digitalis-like action. In etherized cats the order of activity from high to low is telecinobufagin > bufalin > cinobufotalin = cinobufagin.

1. Eight dogs were subjected to total transthoracic gastrectomy and following this were given daily intramuscular injections of a histamine-beeswax mixture for periods varying from 21 to 40 days. 2. In no instance did any ulcers of the esophagus, small intestine or large intestine develop. 3. This supports the hypothesis that histamine-induced ulcers of the gastro-intestinal tract of the intact dog are due to the excessive production of gastric juice.

Excised gills of goldfish cannot maintain a respiratory rate as high in 1 mM sodium chloride as gills in 125 mM sodium chloride at 37 °C even though the intact fish can live indefinitely in these solutions. Studies on the oxygen consumption of gill tissue supplemented with histological observations, indicate that the gill is protected not only by increasing the sodium chloride concentration to 125 millimolar, but by reducing the temperature to 30°C. However, the tissue is not significantly benefitted by the addition of either calcium or rutin to 1 mM sodium chloride.

Both placental and plasma gamma globulins contain Lansing antibody. The 50% neutralizing titer of these products is approximately 10^-3.5, as determined in mice. It would seem that a more potent gamma globulin could be obtained if prospective donors were first tested for serum Lansing antibody level. Then only those with high levels would be used to furnish plasma for the pools to be fractionated. Placental and plasma gamma globulins have a significant sparing effect when inoculated in mice 24 hours before a cerebral challenge of Lansing virus.

1. The administration of citrovorum factor 15 minutes prior to seven to thirty times as large a dose of A-methopterin, prevented the toxicity of the antimetabolite at levels ranging from 2 to 100 times the chronic LD₅₀. 2. No significant protective effect was noted when similar dosages of citrovorum factor were given four or more hours after the administration of A-methopterin. 3. A-methopterin appears to be a true antagonist of citrovorum factor rather than of pteroylglutamic acid.

1. “Folic acid” deficiencies induced by aminopterin and by sulfa drugs in rats have been compared. 2. Aureomycin can counteract the toxic effects of 50, 75 and 100 μg of aminopterin/100 g of diet. The antibiotic is equally effective whether fed in the diet or given intraperitoneally. 3. Aureomycin is without effect on growth in rats made “folic acid deficient” on a sulfa diet. 4. Citrovorum factor concentrates are able to completely overcome the deficiency produced on either type of diet.

These studies indicate that rats on a diet containing what is considered to be an optimum vit. B complex content have the ability to produce circulating complement fixing antibodies when immunized with relatively large amounts of the rickettsiae of murine typhus fever. Likewise, rats maintained on a diet containing only one-tenth of the presumed optimum also have the ability to produce these same antibodies to approximately the same titers. Pantothenic acid and thiamin deficiencies influenced the antibody response when a relatively small amount of immunizing material was injected. The influence is not as apparent when relatively large amounts of the antigenic material was employed.

The action of potassium chloride flooding on the cardiac, renal and adrenal effects of DCA-overdosage was investigated. The data indicate that there is a mutual antagonism between the actions of DCA and KCl on the heart and the adrenal. The role of the kidney in this antagonism is not known.

Recent reports by Chow and associates ( 1 , 3 ) have demonstrated that when vit. B₁₂ is administered orally to rats or humans, no microbiologic activity appears in the urine. They concluded from these observations that oral administration results either in the conjugation of vit. B₁₂ to a form unavailable for the microorganism, in poor absorption in the intestinal tract, or in conversion to a form incapable of being excreted by the kidneys. Later they observed (unpublished work) that stool samples from rats receiving vit. B₁₂ by mouth contained considerably more of this vitamin than stools excreted before administration. Although these data might be taken to indicate poor utilization of vit. B₁₂, this interpretation is complicated by the presence of some vit. B₁₂ in the feces of untreated, normal rats and by the unreliability of the microbiologic assay for this vitamin in stool.

The availability of radioactive vit. B₁₂ containing cobalt⁶⁰ reported by Chaiet, Rosenblum and Woodbury( 2 ) simplifies the analytical problem and permits a differentiation between the administered vitamin from that originally present, granting that the radioactivity due to cobalt⁶⁰ found in the animal represents administered vit. B_12. It is therefore of interest to ascertain the distribution of vit. B₁₂ as manifested by the presence of t radioactive cobalt⁶⁰ reported by Chaiet, Rosenblum and Woodbury( 2 ) simplifies the analytical problem and permits a differentiation between the administered vitamin from that originally present, granting that the radioactivity due to cobalt⁶⁰ found in the animal represents administered vit. B_12. It is therefore of interest to ascertain the distribution of vit. B₁₂ as manifested by the presence of t radioactive cobalt⁶⁰ in urine and stool, as well as in certain organs of rats following oral administration. The results of such a study are reported below.

Experimental. Four normal rats weighing between 250 and 300 g were put into metabolism cages and fed a soy bean diet( 3 ). Collections of urine and stool were made for 2 5 consecutive days. On the third day, 0.89 mg of radioactive B₁₂,∗ with a specific activity 1 of = 0.2 microcurie per milligram, was administered orally to each rat. Daily collections of urine and fecal matter were again made for 3 to 4 consecutive days.

1. By the criteria used there is no significant difference in the destructive effects of irradiation on normal mice or mice treated with large doses of glutathione before irradiation. 2. A striking difference is seen in the rate of regeneration of the hemopoietic tissues.

Electrometric titration of dialyzed visible gastric mucus recovered directly from the stomach of a man with a large gastric fistula and an occluded esophagus revealed an acid binding capacity, if calculated per gram of the dry substance, far smaller than that reported for undialyzed human or animal mucus; the acid binding capacity for mucoproteose and mucoprotein dissolved in gastric juice was even smaller than that for visible mucus. This suggests that dialyzable materials including mineral bases are chiefly responsible for the alkalinity of gastric mucus and the buffering of the HCl of the stomach. The total buffering capacity of mucous substances dissolved in gastric juice ranges from 10.3 ± 3.5 to 1.2 ± 0.4% of the free acid present depending upon the rate of acid and mucin secretion prevailing at the time. It is emphasized that this study has concerned dialyzed and refined mucous substances in the gastric juice. These experiments do not bear upon the ability of the visible gastric mucus which invests the lining of the mucous membrane of the stomach to protect the underlying columnar epithelial cells by physical means (9).

The various mercurials studied show both quantitative and qualitative differences in their cardiac action. In the case of the mercurial diuretics the aminophylline containing compounds produce an increase in the sinus rate as well as ventricular tachycardia while the free mercurials produce only a ventricular tachycardia (Fig. 2). The evidence presented makes it probable that the differences in response of the heart rate are due to the theophylline content of these preparations.

The ST and T wave changes described occurred somewhat prior to the QRS changes. ST and T wave changes are probably related to alterations in the process of repolarization of cardiac muscle while the QRS changes probably indicate mainly changes in intraventricular conduction. The mercurials studied are powerful inhibitors of enzymes containing essential SH groups( 4 , 5 ). Thus the biochemical processes responsible for repolarization of cardiac muscle seem to be more sensitive to these SH inhibitors than the processes involved in intraventricular conduction.

The action of p-chloromercuribenzoate is of interest. It affects only the ST and T wave and thus probably interferes mainly with repolarization of the muscle but has no effect on intraventricular conduction processes. However; it does interfere with atrioventricular conduction and thus, with this enzyme poison it seems possible to inhibit selectively atrioventricular conduction. Differences in the histology and staining qualities of the atrioventricular and intraventricular conductile system have been described by Robb et al.( 6 ) and pharmacological differences are thus not surprising.

1. Testosterone cyclopentylpropionate shows the greatest anabolic and androgenic efficacy of the agents studied. Its increased efficacy cannot be explained on the basis of delayed absorption, suggesting a delayed inactivation of this ester. 2. Aluminum phosphate delays the onset and decline of the anabolic and androgenic actions of testosterone in aqueous suspensions, but produces no such effect upon the actions of methylandrostenediol.

In a previous study ( 1 ) evidence was presented that the infra-red absorption spectrum of the antistiffness factor obtained from sugar cane resembled the spectrum of stigmasterol more closely than any other spectrum of a large series of steroid compounds investigated. Purification and characterization of the natural antistiffness factor in the earlier work was accomplished by solvent partition and spectrophotometric analysis. The present paper is a continuation of this work.

Counter-current distribution was performed in a 24-plate Craig apparatus ( 2 ), a methanol-isooctane two-phase system being utilized( 3 ). Solvent partition was applied to a purified concentrate† from sugar cane, the migration of the material being followed by dry weight determinations and ultra-violet absorption characteristics. On the basis of both the latter analytical technics, the concentrate was divided into 3 fractions, A, B, and C. Infrared analysis of each fraction ascertained the relative purity and aided in characterization of each fraction.

The infra-red absorption data indicated that fractions A and C were free of each other and that fraction A probably was a sterol. The sterol nature of fraction A was further demonstrated by a positive Liebermann-Burchard reaction. Since fraction A gave also a mild, positive Rosenheim color reaction, the presence of some diene impurity was suggested and this was supported by the ultra-violet absorption spectrum of fraction A, which at high concentrations was nearly identical to those of ergosterol, 7-dehydrocholes-terol and other Δ^5,7-diene steroids( 4 ). It was not concluded by Ross, van Wagtendonk and Wulzen( 5 ), despite low extinction coefficients which they obtained, that the similar absorption spectrum of their antistiffness factor was due to a diene impurity.

The infra-red absorption spectrum of fraction A was utilized in screening a large series of steroid compounds, efforts being concentrated on stigmasterol and ergosterol derivatives of the dihydroergosterol type because of spectral similarities.

1. Succinylsulfathiazole was administered orally to 5 normal adults and resulted in a marked decrease in the number of bacteria present in their feces. 2. There were no significant changes in the rectal temperatures of the subjects concomitant with the fall in their fecal bacterial content.