Experimental Biology and Medicine

The diuretic action of thyroid synergistic with anterior lobe is probably not due to its effect in elevating metabolic rate, as is indicated by the finding that a dosage of DNC producing a similar elevation of BMR has no diuretic effect.

The presence of the hypophysis is necessary to adrenal hypertrophy in animals hearing Walker So. 256 tumor. This finding suggests that the pituitary may be essential to any adrenal cortex hypertrophy. Either certain toxins or metabolic processes sensitize the adrenal tissues to the pituitary adrenotropic hormone or they act directly on the hypophysis itself to cause an increased output of this substance. Work is now in progress to determine which process is involved.

Moon 1 noted atrophy of the thymus in rats following administration of the adrenotropic principle of the anterior lobe of the pituitary glands. His observations have been confirmed by Lyons and Simpson of the same laboratory. 2

This investigation deals with the effect on the thymus of administering massive amounts of cortin to normal rats and to rats which had been hypophysectomized. Forty male rats, each having an initial body weight of 180 g, were used. Ten normal animals were untreated and 10 normal animals each received 10 cc of cortin daily in their drinking water (each cubic centimeter of cortin represented 75 g of adrenal glands). Twenty hypophysectomized rats each received an amount of adrenotropic hormone daily which previous assay had proved adequate to maintain the adrenal cortex in hypophysectomized rats. This adrenotropic hormone was prepared and furnished through the courtesy of Dr. H. D. Moon. Ten of the hypophysectomized animals were given 10 cc of cortin daily in their drinking water; the remaining 10 did not receive cortin. In this experiment the intake of food of the 2 groups of hypophysectomized rats was regulated in order to equate the loss of weight. It was necessary to restrict the intake of food in the case of the rats which did not receive cortin to a definitely smaller amount than was consumed by those which did receive cortin. At the end of 7 days all of the animals were killed for necropsy by exsanguination.

The administration of large amounts of cortin causes marked involution of the thymus in the intact rat. The loss of weight which occurred in these animals cannot he satisfactorily accounted for by the small reduction in the intake of food.

Measurements of the apparent oxidation-reduction potentials established in a synthetic medium by the growth of Escherichia coli showed that many irregularities were encountered which were not present when determinations were made in peptone nutrient broth cultures of the same organism. It is the object of this paper to present a study of the factors involved in these irregularities. The elimination of such would make it possible to obtain consistent data from which valuable conclusions might be deduced.

A vacuum tube null-point instrument drawing a maximum current of 10^-11 ampere was utilized in making the physical measurements. No polarization phenomena were observed and the apparatus gave calculated values for easily polarizable half cells. Bright platinum electrodes were used. A liquid medium made by weighing the requisite C.P. or analytical reagents and adding to redistilled water allowed the test organism, Escherichia coli, to grow vigorously. This basic solution, a slight modification of that of Koser and Saunders, 1 was composed of Na₂HPO₄ 1.4 g, KH₂PO₄ 1.0 g. NaCl 2.0 g. MgSO₄ (anhy.) 0.1 g, 1-asparagine 3.0 g, 1-tryptophane 0.2 g. d-glucose 2.0 g, and redistilled water 1 liter. Sterilization was accomplished by filtration. The final pH was 6.9. A nutrient broth medium used for comparison was composed of beef extract (Swift) 3.0 g, peptone (Difco) 10.0 g, NaCl 5.0 g, and redistilled water 500 ml. This was adjusted to a pH of 6.9, sterilized in the autoclave, and to it was added 500 ml of sterile phosphate buffer (pH 6.9 at 37.5 C). The buffer was present in a final concentration of M/30.

Culture vessels consisted of 180 nil electrolytic beakers stoppered with rubber stoppers containing appropriate holes for the electrodes, for a stirring apparatus, for the agar-KCl bridge and to allow for gas exchange. The medium, previously inoculated with E. coli, Was pipetted into the electrode containing vessels after the latter had been sterilized in the autoclave.

Precipitins for blood proteins disappeared from the circulating blood of rabbits immunized with renal and hepatic tissue as soon as these antigens are exhausted from the injected-tissue depots. The exhaustion of the tissue-proteins usually takes a much longer time. This provides a method for the preparation of tissue antisera. Extracts of fresh liver and kidney do not give precipitative reactions with the antisera, but the autolyzed products of these organs do, Liver-autolysate seems to have an antigenic factor in common with the autolysate of kidney, pancreas, spleen, adrenals, and thyroids. Kidney-autolysate has an antigenic factor in common with liver but not with any of the other above-mentioned organ-autolysates.

1. In the experimental animals, the feeding of inorganic phosphorus in doses large enough to cause transverse metaphyseal lines, has no demonstrable effect on the roentgenographic or microscopic appearance or the healing of fractures. 2. Transverse bands of increased density which may be produced at the juxta-epiphyseal region of growing children or animals by the feeding of phosphorus are probably “growth arrest lines” similar in their etiology to those produced by acute diseases such as scarlet fever

Results given previously 1 have shown that bovine serum displayed a greater bactericidal activity against Brucella abortus than did a comparable amount of whole blood. Trials have accordingly been made to determine whether an increase in the titer of the serum bactericidins was to be found in individuals which had recovered from an infection with this organism.

The technic employed was essentially the same as that previously described. 1 2 The serum was taken from, (a) cows which had previously been artificially infected with Br. abortus, and from whose blood practically all agglutinins for the organisms had disappeared (i.e., “recovered”) and (b) from other animals which, insofar as was known, had had no contact with the organism (i.e., “normal”).

A uniform quantity (0.3 cc) of serum, or of dilutions of serum, from an individual was added to each of a series of small tubes into which had been placed 0.05 cc of decimal dilutions of a 36- or 48-hour culture of a standardized saline suspension of Br. abortus. To each of the tubes containing diluted serum was then added 0.2 cc of complement of beef serum. (The complement was obtained by absorbing beef serum, with heat-killed cells of Br. abortus, at 0 °C for 20-30 minutes.) Following incubation for 22-24 hours, the contents of each tube were poured into a petri dish with fluid pork-infusion agar, and incubated 5 or 6 days. For the bacterial control, 0.05 cc of each of the different dilutions was mixed with the fluid medium and poured into petri dishes. In these tests the number of organisms in the final dilution (-7) was generally between 10 and 50. Heated serum (0.3 cc). complement (0.3 cc), and the combination of heated serum (0.3 cc) and complement (0.2 cc), respectively, were treated in the same manner as the serum and diluted serum above.

In the English sparrow, prolonged injection of sheep thyrotropic hormone does not lead to the development of refractoriness. The thyroids remain enlarged and hyperplastic, and the elevation in metabolic rate is maintained over periods up to 5 months.

1. The combined testis and epididymis weight in rats is reduced about half after 50 or more one hour exposures to illuminating gas. The number of spermatozoa is greatly decreased and motility in the few viable sperm is impaired. 2. The hypophyses of gassed male rats become highly basophilic and many vacuolated castrate cells appear. 3. The gonadotropic hormone content of the hypophyses of gassed rats is increased.

In the course of conditioned motor reflex experiments on goats, we had the opportunity of observing so-called “stiff-legged” goats. Four such animals were furnished us through the kindness of Mr. D. E. Motlow, of Lynchburg, Tennessee.

It has been noted for years that animals of this strain, when startled, stiffen and fall over, remaining immobile for some seconds in what at first appears to be a general tonic spasm. Accordingly, they have commonly been labelled “nervous,” “stiff-legged” or “epileptoid” goats.

Our investigations show, however, that this seizure is not a general tonic spasm produced by a special type of stimulus, but is caused by the failure of individual muscles to relax normally when strongly stimulated after a period of rest.

Stimulation of the motor points of the thigh with an adequate faradic current produces, not a simple twitch, but a tetanic contraction of the individual muscle or muscle group, with relaxation in from 5 to 30 seconds. On successive stimulation, the period of relaxation is progressively shortened until it approaches the normal twitch. Percussion of the muscle elicits a myotonic contraction of a few fibers, with characteristic slow relaxation.

Since the demonstration that sulfanilamide is an effective therapeutic agent in the treatment of infections caused by the coccal group of bacteria, many tests have been made of its possible value in the treatment of other diseases of varied etiology, particularly those for which no specific drug is known. So far, sulfanilamide has not been found of value in infections caused by bacilli, filterable viruses, 1 or animal parasites. 2 In view of the belief that the drug may act to increase host-resistance and to neutralize toxins, it was thought worthwhile to test its value in the treatment of trichiniasis, a disease in which the symptoms are mainly the result of toxemia, and for which there is no known effective drug treatment.

Two experiments were performed in which full-grown rats were infected by stomach tube with known numbers of Trichinella spiralis larvae, obtained free from infected rat muscle by artificial digestion. 3 In each experiment, one group of rats were given treatment with sulfanilamide (para-amino-benzene-sulfonamide), while another group were kept as controls. The dosage of sulfanilamide was the same as that employed by Gross and Cooper 4 for the treatment of pneumococcal infections in rats, namely, 125 mg per day. The drug was ground to a fine powder, suspended in a 10% solution of gum acacia, and given to the animals by stomach tube. Details of administration are presented in Table I. Usually, treatment was begun on the day after infection, at a time when the adult worms were developing in the intestine, and was continued during the period that the young larvae were developing in the muscles.

Human ascitic fluid, when administered to group compatible recipients, is capable of raising and maintaining the blood pressure in secondary shock.

The increasing number of studies on the metabolism of ketone bodies has made a method for the preparation of pure l-beta-hydroxybutyric acid desirable. The easiest way to accomplish this is to synthesize it in the animal body. Although it may be obtained from the urine of fasting human subjects, it may also be readily produced in large amounts from the urine of fasted rats fed sodium butyrate according to the earlier procedures from this laboratory (0.237 g of butyric acid daily per 100 g rat in solution by stomach tube in divided doses morning and evening). When 85 female rats weighing 125-150 g were used, 58 g of l-beta-hydroxybutyric acid were excreted in a 4-day period of which 34 g were recovered as the pure Ca-Zn double salt. Although a similar procedure might tie employed with a smaller number of clogs, our experience has been that rats are particularly well adapted because they can not regurgitate. The following method was employed in separating the acid in pure form.

To the pooled urines is added sufficient solid copper sulfate to obtain a concentration of 20%. To the resulting solution is added 0.5 g calcium hydroxide (in 10% aqueous suspension) for each gram of copper sulfate present. This amount of the base usually suffices to bring the pH slightly alkaline to litmus. If the pH is not alkaline to litmus after standing 1/2 hour more calcium hydroxide should be added. The mixture is then filtered by suction, working the precipitate with a spatula to a dry, hard cake, to express as much of the liquid as possible.

The filtrate is evaporated under reduced pressure to a syrup. At this point the precipitated salts may be filtered off.

In certain models employed to imitate living cells the behavior of water appears to be the opposite of what is expected. If it acts similarly in vivo it is not hard to understand why the living cell often fails to behave as a perfect osmometer.

In these models water moves through liquid layers against a gradient, passing from a region where its activity is low to one where its activity is high. This depends upon the fact that certain substances traversing these layers appear to carry water with them.

The simplest form of model is made as follows: In a U-tube (Fig. 1) we place guaiacol∗ (B) to imitate the action of the protoplasm. 1 Resting on the guaiacol (which forms a separate phase in contact with water) at the left is an aqueous solution (A) representing the external solution, and at the right an aqueous solution (C) representing the cell sap.

We may begin by putting in B some guaiacol which has been shaken with distilled water until equilibrium has been attained: in A and C we place equal amounts of the water which has been shaken with guaiacol. The system is therefore in equilibrium throughout and no movement of water occurs.

When we lower the activity of the water in A by adding trichloroacetic acid we might expect water to move from C to A, but just the opposite occurs. Acid and water move from A to B and from B to C. The higher the concentration of acid in A the greater the movement of water into C.

In addition to “alkaline” phosphatase, blood serum contains minute amounts of one or more “acid” phosphatases of the type classified by Folley and Kay as phosphomonoesterase A₂

Methods are described for producing high-titered group-specific antisera for classifying hemolytic streptococci into groups. A description is also given of a reliable micro-precipitin technic which can be used with very small amounts of bacterial extract and antiserum. Attention is called to the occurrence of some non-hemolytic members of Groups B, C, D, and G.

Since this communication was submitted for publication, Fuller has reported a method of extracting streptococci with formamide. 5

The extraordinary cyanosis shown by patients during sulphanilamide therapy has received no explanation.

Marshall, 1 King, 2 and others have demonstrated that the respiratory function of the hemoglobin is unaltered. Methemoglobin and sulphemoglobin have been found in some cases but in amounts far too small to explain the intense cyanosis. The plasma of cyanotic patients appears normal. Whole blood, whether arterial or venous, has a chocolate brownish tinge. Though such blood when aerated gains oxygen in normal amounts it does not become bright red but remains dark. This led us to seek for a colored derivative of sulphanilamide in the erythrocytes.

After various unsuccessful attempts we were led by the known helio-sensitivity of sulphanilamide-treated patients to try the effect of ultraviolet light. This enabled us to reproduce the phenomenon in vitro and to offer an explanation for the cyanosis.

We found that dilute solutions of sulphanilamide on very brief exposure to ultraviolet light develop a strong violet color. The nature of the chemical change is so far unknown.

When red cells are added to such solutions they at once adsorb the violet substance from the supernatant fluid and assume the color shown by the red cells of patients under sulphanilamide therapy. Plasma added to the violet solutions causes the color to disappear.

The violet substance is only the first of several colors produced by irradiation of sulphanilamide. It is developed only by irradiation of short duration, one half to one or at most 3 minutes. When irradiation is continued for longer periods the color rapidly changes to yellow, then brownish.

The present investigation was undertaken to determine whether estrogenic hormone can be absorbed through the human skin. Absorption was estimated on the basis of the application to the human female of the Allen-Doisy test. Papanicolaou and Shorr 1 have demonstrated that the human vaginal secretions after the menopause or castration exhibit certain striking cytological features, characterized chiefly by the presence of small, round or oval epithelial cells (“deep cells”) with rather large, well-staining nuclei and associated with a varying number of leucocytes. These investigators have shown that following administration of adequate amounts of estrogenic hormone the leucocytes and “deep cells” disappear and are supplanted by large, squamous epithelial cells, characteristic of the follicular phase of normally menstruating women. In the present study an attempt was made to determine whether similar vaginal smear changes could be produced in human females by means of skin inunctions with an estrogenic hormone.

A group of women were chosen who were considered, on clinica grounds, to have either marked ovarian deficiency (post-menopause or X-ray castration) or no ovarian function at all (bilateral oöphorectomy). Of these, 14 were selected whose vaginal smears during a period of observation of 2 weeks were found to be constantly “negative” (Reaction I or 0), 2 indicating absence of estrogenic activity. The vaginal mucous membrane changes of this group of women, as revealed in the smears, constitute sensitive test objects for estrogenic substances.

Sarcoma of mice can be transmitted with approximately 50 cells.

Two theories have been offered to account for the presence of syphilitic reagin in the spinal fluid of patients with neurosyphilis: (1) that the reagin is derived from the blood by filtration due to impairment of the normal physiologic barrier, 1 (2) that the reagin is largely formed locally. 2

It is generally accepted by immunologists that the syphilitic reagin is a true antibody, this belief being supported by the parallel behavior of syphilitic reagin and other antibodies both in the test-tube and in the body. 3 As an example of the latter, and in relation to the present problem, may be cited the conditions under which syphilitic reagin and other antibodies occur in umbilical cord blood. Thus, it has been shown that the isoagglutinins are not developed in newborn infants, and any present in such serum were derived from the mother by filtration through the placenta. In the course of a few weeks or months these “borrowed” isoagglutinins disappear and then the child forms its own. 4 The behavior of the syphilitic reagin is exactly parallel; a positive Wassermann or flocculative reaction on umbilical cord blood or the blood of newborn infants being diagnostic of syphilis in the mother and not necessarily in the child. 5

Accordingly, one method of attacking the problem whether or not syphilitic reagin present in the spinal fluid was derived from the blood by passive transfer is the comparison of the behavior of the reagin with that of the isoagglutinins.

The experiments described indicate conspicuous differences in susceptibility to X-rays among different neoplastic cells of mice. They support the opinion that X-rays so injure cells that multiplication can proceed only for a few cell generations, after which they degenerate and die. Viruses producing neoplasms are far more resistant to X-rays and it seems probable that exposure in vitro to approximately 15, 000 r units of X-rays distinguishes between virus-containing and virus-free neoplasms, the latter losing the ability to transmit the disease when exposed to 15,000 r units of X-rays in vitro. Viruses are unaffected by the amount of irradiation used in these studies. Irradiated sarcoma cells multiply for several days and then die. Hence, failure to produce the disease with irradiated neoplastic cells is the best evidence available thus far that the neoplasms of mice studied are not transmitted by viruses.

The purpose of this investigation was to study the relationship between the calcium of the cord blood and that of the peripheral blood during the first 10 days of life. If a low cord blood calcium regularly were associated with a low calcium during the first 10 days of life, then hypocalcemic tetany of the newborn could be predicted and prevented. In the 47 cases thus far examined there is a rather constant relationship between the cord and the postnatal blood though not of the nature mentioned above. There is a tendency for the serum calcium to assume values lower than the cord blood during the first 4 days of life and then to rise toward the prenatal level during the next 5 days.

The average calcium of the serum of cord blood was 11.60.

The average deviation of peripheral blood from cord blood of the same individual was

—1.04 for the 1st to 2nd days (11 cases)

—1.21 for the 3rd to 4th days (16 cases)

—0.36 for the 5th to 6th days (8 cases)

+0.55 for the 7th to 9th days (12 cases)

While this work was in progress Bakwin 1 reported similar findings, based on data obtained from different sources. Our figures were obtained from the cord and postnatal blood of the same babies, whereas Bakwin compared the results of 67 examinations made during the first 10 days of life with calcium determinations on 300 cord bloods performed some years previously.

Serum inorganic phosphorus tests were done on a few cases but are not sufficiently numerous to warrant reporting.

Studies of other factors, inorganic phosphorus, total protein, blood cell concentration, feeding, etc., are being continued to determine what circumstances may influence the calcium level variations.

The theory that hypertension may be due to the accumulation of a humoral pressor substance or substances of renal origin has been supported by the finding of increased concentrations of pressor material in kidneys from patients with various hypertensive diseases 1 and from dogs with experimental renal hypertension, 1 2 3 Against this hypothesis is the failure to find increased pressor properties in the blood of subjects with hypertension. 4 Recent chemical studies 5 indicated that the pressor principle in rabbits'kidneys is related to the globulins. This work suggested the possibility of concentrating the hypothetical pressor substance in blood by similar chemical procedures. The present report is concerned with the vasomotor properties of extracts of human and of dog's blood containing protein fractions prepared in the following way.

Approximately 100 cc of freshly drawn blood was defibrinated and centrifuged. The serum was drawn off and half saturated with ammonium sulfate, and the resulting precipitate dialyzed against tap water until free of sulphate. The dialysate was then dried in a Florsdorf-Mudd apparatus 6 and taken up in a small volume of saline. The final solution was tested by intravenous injection into small unanesthetized dogs with Van Leersum (carotid) loops, and the effect on the blood pressure noted.

Observations were made on the blood of 5 patients with persistent hypertension, and 3 dogs with hypertension due to renal ischemia. 7 In no instance was a well-defined pressor response noted.

The failure to find the renal pressor material in the blood stream may be due to a number of possible causes, such as inefficient extraction, insufficient amount of the pressor substance in the blood stream, or differences between the chemical properties of renal pressor substance in man and rabbits. It is also possible that ultimately the pressor substance may prove to have no relation to hypertension.

A method for measuring the inhibitory activity of heparin on the clotting of blood has been worked out by Fischer and Schmitz. 1 Instead of using as Howell 2 does an arbitrary effect as a unit for the inhibitory activity, this method gives a curve of the action of varying concentrations of the anticoagulant, and from the equation for this curve the activity of the substance is denned. From the activity (k) obtained in this way a unit for inhibitory substance has been defined by Astrup and Behrnts Jensen 3 as the quantity of active substance contained in one gram of a material which gives the value 1 for k under the given experimental conditions.

This method has been modified by Chargaff, Bancroft and Stanley-Brown 4 and used in their recent work on blood coagulation. By this modification, curves for the inhibitory action of various concentrations cannot be determined as by the original method of Fischer and Schmitz (l.c.) and the necessity of determining such curves is here pointed out.

As the measurement of the clotting time of a blood plasma is far from being an ideal method, it is obvious that the accuracy is greatly increased with the estimation of an inhibition curve. For 5 different concentrations of an inhibitory dye, Chlorazol fast pink (Boot's Pure Drug), the activity was determined only from the differences between the clotting time of these solutions and the solutions containing one-half the original concentrations (Fischer and Schmitz 1 ). The following values for k were obtained: 0.184, 0.247, 0.232, 0.140, 0.304. The average value was 0.221 in good agreement with the value 0.215 obtained from the slope of the straight line established when the logarithm of the clotting time was plotted against the concentration of the inhibitory substance.

Following the intracisternal injection of colloidal kaolin, the rat will develop arterial hypertension associated with increased intracranial pressure. 1 2 For the sake of brevity, we shall refer to such an animal as a kaolin-hypertensive rat. The elevation of blood pressure was interpreted as being the result of hyperactivity of the vasoconstrictor center in consequence of the increased intracranial pressure.

Because ergotamine is known to paralyze peripheral parts of the sympathetic nervous system, it seemed possible that this substance might influence arterial hypertension so produced. Hogler 3 has reported no lowering of the blood pressure by ergotamine tartrate when given in the dose of one mg to dogs made hypertensive by kaolin. However, Hogler's first blood pressure readings were taken one hour after the injection of ergotamine tartrate so that a transitory effect might have been overlooked.

In addition to producing prolonged hypertension associated with increased intracranial pressure, we also elicited an acute type by introducing physiologic saline into the cisterna magna at a measured pressure. This afforded a second type of test animal for investigating the effect of ergotamine.

Normal and kaolin-hypertensive albino rats were used. Light, uniform ether anesthesia was employed for all procedures. Blood pressure determinations were made by an indirect method previously described. 4 Ergotamine tartrate† was given intraperitoneally in the dose of 0.05 mg per 100 gm body weight.

Ten normal rats were injected with ergotamine tartrate, the blood pressure being followed for approximately 10 minutes before and for at least 30 minutes after the injection. No effect on blood pressure was noted.

Thirteen kaolin-hypertensive rats were similarly treated. In every instance there was a marked but transitory fall in the blood pressure (35-160 mm Hg).

Previous reports 1 2 reveal that ligation of the lumbo-adrenal veins results in an amelioration of experimental diabetes as evidenced by diminished glycosuria and ketonuria and a basal R.Q. elevated above the diabetic level. The present experiments were conducted in order to determine the ability of renal cortex to utilize carbohydrate. Renal tissue from diabetic animals is incapable of utilizing added glucose and the respiratory quotient remains close to 0.7. The results obtained on the ligated depancreatized animals are presented in Table I. It will be noted that the basal R.Q.'s on the tissues of dogs 3 and 4 were definitely above 0.7. In all the experiments, glucose produces a questionable rise in oxygen consumption and R.Q., while lactate causes a significant increase in both oxygen uptake and respiratory quotient. The level of the blood sugar at the time the kidney was excised did not influence the character of the result. Previous work on hypophysectomized depancreatized animals failed to reveal an elevated basal R.Q. 3 and the addition of glucose failed to stimulate metabolism but lactic acid was oxidized. Further experiments are now in progress to determine whether a larger series of kidneys excised from hypophysectomized depancreatized animals would yield results similar to those obtained from the depancreatized preparation with lumbo-adrenal veins ligated.

Cats treated for 3 hours at an oxygen tension of 53 mm Hg show a 40% decrease in the adrenin content of their adrenals, as determined by an adaptation of the Moodey colorimetric-technic.

The isolation of pregnandiol from the urine of pregnant mares has been reported by Marker, et al. 1 A method for the isolation of pregnandiol from the urine of pregnant mares based on a method for the quantitative determination of pregnandiol in human pregnancy urine 2 is herewith described because of its relative simplicity and possible application in the study of the function of the corpus luteum of other animals.

The fresh urine∗ without the addition of preservative is incubated at 37°C for 96 hours. It is filtered with suction and the precipitate is collected and heated with 100 cc of 95% ethyl alcohol. The alcoholic mixture is filtered with suction. This filtrate is evaporated to dryness and the residue taken up in 10 cc of acetone and 10 cc of a 0.1 N solution of NaOH. When complete solution is effected with moderate heating, the volume is brought to 50 cc by the addition of 30 cc of 0.1 N NaOH. The solution is placed in the cold and pregnandiol completely precipitates when the solution is thoroughly chilled. The pregnandiol is collected by filtration with suction and the precipitate is washed with warm water. The precipitate is dissolved in a minimum amount of hot acetone and 2 volumes of 0.1 N NaOH added. This is put in the cold to effect precipitation. A third precipitation using a minimum amount of ethyl alcohol and two volumes of water usually give a pure product.

The essential points in the procedure are: (1) The liberation of the free form of pregnandiol from its conjugation form by enzyme action during incubation; (2) the insolubility of pregnandiol in aqueous solutions such as urine : (3) the purification of pregnandiol by precipitation from alkaline acetone.

Neither of the 2 isomers of nicotinic acid was able to replace nicotinic acid itself in the nutrition of S. aureus. when tested in concentrations up to 20 gamma per 10 cc of medium. Reduction in the activity of nicotinic amide was brought about by introduction of an ethyl group. Complete loss of activity was evident by introduction of 2 ethyl groups into nicotinic amide. Pyridine 2-3:dicarboxylic acid was inactive as a factor in the growth of S. aureus.

Horwood and Webster 1 recently asked the question: “Is Escherichia coli a derivative of Aërobacter aërogenes in the human intestine?” The question was prompted by their study of Gram-negative lactose-fermenting bacteria from the ileostomy and fecal discharges of a patient. They found that 87.5% of the cultures from the ileostomy discharges were Aërobacter aërogenes, while those from the rectal discharges were all Escherichia coli.

The possibility that all members of the coliform group 2 of bacteria may be variants of only a few species of the group had been suggested to the writer by his experience with a group of 259 strains of coliform bacteria isolated differently from specimens of water, fish fillets, and feces. These strains had been carefully purified by approved methods. They were carried for 3 years on nutrient-agar slants, being transferred once each month to fresh media. Once each 6 months differential tests were made, the tests employed being the Voges-Proskauer, methyl-red, sodium-citrate, uric-acid, indol, and sodium-malonate. It was noted that many of the strains classified as Escherichia coli and as Aërobacter aërogenes remained constant in their reactions; but there was a pronounced tendency on the part of many strains, especially the intermediates, to vary in their reactions over the 3-year period.

The experience of Horwood and Webster, following as it did upon the author's experience, prompted the study reported here. The study was based upon the following assumption: If the intestinal environment is capable of inducing marked alterations in the biochemical behavior of Aërobacter aërogenes, it seemed that bile and its constituents would be likely factors in inducing these alterations. Therefore, it was the purpose of this study to determine the influence of prolonged propagation of Aërobacter aërogenes in media containing bile and bile salts, on the biochemical reactions of the organism.

The known facts of thyroid physiology indicate that iodine is selectively taken up by the thyroid gland, and that in some measure that gland's function is regulated by its iodine content. Artificial radioactivity may be induced in a variety of elements by means of neutron bombardment. It seemed that the possibility of using “tagged” (radioactive) iodine as a physiologic indicator was one which demanded investigation.

Ethyl iodide (600-1000 cc) was irradiated in a paraffin-surrounded bottle by immersing in it a neutron source consisting of 110 mg of radium mixed with beryllium in a sealed tube. The radioactive iodine thus obtained was concentrated by a method which has been described elsewhere. 1 This method gave a precipitate of radioactive silver iodide, which was dissolved in a solution of 0.5-1.0 g of sodium thiosulphate, and then diluted to 10-15 cc for intravenous injection. In a series of 48 rabbits, no toxic effects from the acute administration of such quantities were experienced. Aliquot portions of the solution of radioactive iodine used for injection were withheld for measurement of radioactivity.

A Geiger-Müller counter connected to a suitable vacuum tube amplifier and register to record the individual disintegrations of the radioactive atoms was used for detection of the radioactive iodine in various tissues. This apparatus is standardized and has been fully described elsewhere. 2 3 4 Since no gamma rays could be observed from radioactive iodine,¹ determinations had to be made from the beta radiations. The half-period of radioactive iodine is 26 minutes, so that accurate measurements could not be extended beyond about 40 minutes after injection, with the activities available to date.

The existence of the pyloric chemical phase of gastric secretion has been sufficiently proved experimentally, but its hormonal mechanism, postulated by Edkins, 1 has been doubted. The many attempts made to establish the chemical identity of the hypothetical “gastrin” did not produce conclusive results (for literature, see Babkin 2 and Ivy 3 ). Recently Sacks, Ivy, Burgess and Vandolah 4 isolated histamine from the pyloric mucosa, and concluded that “histamine is the gastric hormone, or if not, there is no gastric hormone, or the gastric hormone has never been extracted from pyloric mucosa.” This view was reiterated recently by Schnedorf and Ivy. 5

The experiments reported below demonstrate clearly that a protein-like substance, having a specific secretagogue effect on the fundic glands can be extracted in a histamine-free form from the pyloric mucosa, and in lesser quantity from the duodenum. Twenty-one experiments were carried out on cats under chloralose-urethane anesthesia, in which the gastric and pancreatic secretion, the bile flow, and occasionally also the blood pressure, following intravenous administration of various extracts prepared from different parts of the dog's stomach and intestines, were studied. The chemical procedure that was adopted for the preparation of crude extracts is as follows: The mucous membrane from different parts of the stomach of freshly killed, fasting dogs is removed with the aid of a knife and minced; intestinal mucosa is removed by scraping and ground with sand. The tissues are boiled with 10 volumes of n/10 HCl, partially neutralized with n/l NaOH to the point where it remains only slightly acid to Congo. After cooling, the extract is centrifuged. The supernatant fluid is filtered through cotton and precipitated with 10% crystalline trichloroacetic acid. The precipitate is centrifuged and washed 3 times with 40 to 50 volumes of 10% solution of trichloroacetic acid in saline, twice with 50 volumes of acetone, once with benzene, and twice with ether, and dried in vacuo.

The injection of adequate amounts of either adrenal cortical extract or the crystalline compound B of Kendall will not only prevent the depletion of the carbohydrate stores of fasted hypophysectomized rats, but will also restore them after they have been depleted by fasting.

It is now well established that the intercellular substances in general, and the collagen of all fibrous tissue structures in particular require ascorbic acid for their production and maintenance. Aschoff and Koch 1 made thorough postmortem studies of World War soldiers who had died of scurvy, and demonstrated constant pathological changes in the supporting tissues of the body. Höjer 2 found a general atrophy of the connective tissue in scorbutic guinea pigs, and pointed out for the first time a general deficiency in the formation of collagen. In a series of more recent communications Wolbach 3 4 5 and his collaborators confirmed the observations of Höjer, and conclusively showed that ascorbic acid is intimately concerned with the synthesis and maintenance of intercellular supporting materials. Jeney and Törö, 6 when they added ascorbic acid to the nutrient medium of a culture of fibroblasts in vitro, found a marked increase in the number of collagen fibrils that were produced.

Since the repair and tensile strength of soft tissue wounds are direct functions of fibroblastic proliferation and collagen formation, it is at once apparent that Vitamin C may play a prominent rôle in the phenomenon of wound healing. Saitta 7 reported a delayed healing of exposed surface wounds in guinea pigs that had been kept on a Vitamin C deficient diet for more than 15 days. On the other hand, when a Vitamin C containing extract was applied directly to the wound, the healing time was appreciably diminished, regardless of whether the animals were maintained on a normal or a scorbutic dietary regime. He determined the rate of healing by actual daily measurements of the length and breadth of the wound.

By using suitable adaptations of the methods developed by Langmuir, Schaefer and Blodgett 1 2 films of salmine, insulin, thymus histone, thymus nucleic acid, trypsin, and casein have been built up on chrome plated iron or on stainless steel plates. These plates were first covered with a suitable number of layers of barium stearate by the method of Blodgett. 2 They were then immersed in a 10^-3 M solution of uranyl acetate at pH 6.0 to condition the barium stearate surface, thus rendering it hydrophilic. Each conditioned plate with an adhering layer of water was then immersed in a 0.1% solution of the substance to be adsorbed and shaken in this solution for the period of time cited. The plate was then removed, washed, and dried in air. The insulin and other surface films described below were thus formed by adsorption of molecules or molecular aggregates directly from solution and not by transfer of films previously formed on the surface of a solution. The thickness of such films has been studied as a function of a number of factors of physiological interest, such as the nature of the adsorbing surface, the time of exposure of the plates to the solutions, and the concentration, salt content, and pH of the solutions to which the plates were exposed.

The purpose of the present paper is to point out, in a preliminary way, the great influence of pH in determining the thickness of certain of these films, using typical experiments with salmine, insulin, and casein as examples. The present experiments were made at room temperature, 25°-30° C, with the salt content of the solutions kept at the minimum level.

From the above results it may be concluded that the monolayer film method provides a valuable means for the study of antigen-antibody systems as regards molecular dimensions, combining properties, and other aspects of their behavior.

Cyclopropane causes an increase of both intestinal contractions and tone in the first 2 planes of third stage anesthesia; in the lower planes of third stage contractions are inhibited but tone is maintained. Ether, on the other hand, causes an abolition of the contractions in all planes of surgical anesthesia.

Following a single electric stimulus applied to the optic nerve, electrical potentials of 3 types are recorded from the optic cortex (Fig. 1). The first is a series of 4 or more spikes, each of 1 m.s. duration, comparable to the spikes of peripheral axons. The second is a series of waves, each of 5 to 10 m.s. duration, and the third, a series of waves of much longer duration (Fig. 2), comparable to the alpha waves. These slower potentials do not behave like after-potentials of the spikes. The first spike may follow a stimulus within 1.8 m.s. The following spikes occur at about 1.5 m.s. intervals, and are not simple repetitions of the first, but can be differentiated from it by differences in polarity at different depths in the cortex, by effects of anesthetics, etc. The spikes appear to represent activation of successive groups of elements rather than repetitive activation of one group. These spikes had not previously been recognized in the rabbit cortex, but with improved recording technic can now be seen to be present there also, of relatively lower amplitude. The short waves, 2 or 3 in number, correspond to those identified in the rabbit as the specific visual response. The long waves, often repetitive at 1/5 to 1/8 second intervals, correspond to the response in the rabbit of the alpha mechanism. These 2 series of slower potentials are differentiated characteristically by anesthesia and strychnine, as in the rabbit (Bartley, O'Leary, and Bishop 1 ).

We have investigated the responses of these elements to repetitive stimulation in the cat under different degrees of anesthesia. Magnesium sulphate, 0.25 g/kg or less, with ether as necessary during the preliminary operative procedures

Rapidly repeated flashes are seen as steady light, equivalent in sensory brightness to the same amount of light uniformly distributed in time. This is Talbot's law, and the outcome is what would be expected from a simple train of events copying the output of the photoreceptors.

But as soon as flash rate is reduced below the fusion point for steady sensation, the flashes begin to produce an average impression which is greater than that expected from photochemical considerations. As the rate is reduced more and more, the flashes produce an effect more and more nearly equivalent to steady light of the same physical intensity, and finally surpass it, reaching a maximum when the rate is reduced to the neighborhood of 8 or 10 per second. With still slower rates, the flashes approximate equivalence to steady light, with the recognized exception that single isolated flashes always appear brighter than steady stimulation of the same intensity.

The phenomenon of enhancement was first observed in 1864 by Brücke with rotating black and white sectored discs, but was not plotted for various rates of intermittency. The phenomenon shall be called the Brücke effect, though we used flashes instead of the revolving discs.

The significance of the Brücke effect is that a series of momentary stimuli is more effective for sensation than steady stimulation of the same strength. In order to account for this, the responding system must act very different from what would be expected of photoreception in the sense cells. Since the nervous system is capable of rhythmicity and periodic facilitation, we might look immediately to it. And since the maximum Brücke effect occurs at flash rates of 8 to 10 per second, such a periodicity should be sought to account for it.

The observation of spirochetes in the gastric glands of Macacus rhesus by Cowdry and Scott 1 prompted the study of the incidence of these organisms and reaction associated with or caused by their presence in the sections of the gastro-intestinal tract of the animals used in their study. Sections of human stomach taken at necropsy in the Department of Pathology of Washington University School of Medicine were made available by Dr. H. A. McCordock.

As early as 1884 Escherich 2 observed and reported spirochetes in the stools of patients with cholera. Spirochetes were described by Bizzozero 3 in the gastric glands and parietal cells of dogs in 1893.

In spite of the many reports of spirochetes in the stools of normal humans as well as in cases of so-called “spirochetal dysentery” which had been cured in many cases by treatment with arsenicals, a review of the literature fails to reveal observations or studies of these organisms in the human stomach. Mühlens 4 and Luger and Neuberger 5 have reported spirochetes in ulcerating carcinomas of the stomach but reports of spirochetes in the gastric glands or parietal cells of humans were not found.

Kasai and Kobayashi 6 experimented with lower animals which showed a definite tendency of these spirochetes of cats to become pathogenic to rabbits. Hemorrhagic erosion and ulceration of the mucosa about masses of spirochetes was described.

Edkins 7 described what he considered a granular phase of these spirochetes in cats when the cats were not fed for several hours.

In all the observations reactions to these organisms are not reported.

In Macacus rhesus the spirochetes were observed in the gastric glands and parietal cells (hematoxylin and eosin stained sections) in 100% of 24 control animals and 19 test animals. The marked tendency for these organisms to invade the parietal cells was noted. In most cases a few spirochetes were also seen in the neck chief cells.

Previous work indicates that the administration of male hormone substance produces behavioral as well as organic changes. In baby chicks, aggressiveness, strutting and crowing have been induced. 1 In man, greater capacity for penile erection 2 and increased aggressiveness, energy and self-assurance have been noted. 3 This paper reports additional data on mental and behavioral changes during treatment with testosterone propionate∗ of 2 adult castrates, 2 cases of hypogonadism and 2 cases of apparently psychic impotence. Testosterone propionate was administered subcutaneously from 3 times weekly to once daily in doses of 20 mg dissolved in 1 cc of peanut oil. As controls, of which the patients were not informed, injections of oil without hormone were given for periods before and during treatment.

Before treatment all patients were definitely lacking in any conscious goading sex drive, in the capacity for penile erection and even in the ability to enjoy sexual sensations from acts such as kissing and embracing. While the 4 patients who had once been normal could occasionally muster enough penile erection to effect vaginal entrance, these were too brief and weak to bring satisfaction to either their wives or themselves. With complete absence of either penile sensitivity or general emotional responsiveness, they reported that intercourse had become mere “arduous work.”†

All patients were disturbed, anxious and broken in spirit. They ranged from moderate to severe states of mental depression. The 4 definitely organic cases displayed additional symptoms. These patients suffered from vasomotor disturbances (hot flashes), such as women may experience at the menopause, and manifested very definite emotional instability characterized by sudden uncontrollable shifts in mood, by tendencies to break down into tears, by periods of extreme irritability and, sometimes, by sullen anger.

Since there is evidence that there is an in vivo hemolytic process involved in pernicious anemia, 1 we have carried out measurements of the resistance, to saponin and other lysins, of red cells from cases of pernicious anemia in relapse and in remission.

The methods used were those described by Ponder. 2 Suspensions of red cells from normal oxalated blood and from the oxalated blood of cases of pernicious anemia are made by suspending the thrice-washed cells in sufficient 1% NaCl (or buffered Ringer at pH 7.0) to give 2.5 (10⁸) cells/cc. A series of dilutions of saponin, or of another lysin, is then prepared in 1% NaCl, and time-dilution curves for complete hemolysis are plotted at 25°C up to times as long as 300 minutes, and in some cases 600 minutes. Under these circumstances, the resistance of the cells from the blood of cases of pernicious anemia, relative to the resistance of the normal cells, is simply and properly expressed by a constant R∞, obtained by dividing the asymptotic concentration of lysin for the cell suspension whose resistance is sought, by the asymptotic concentration for the cell suspension from the normal control (R∞ = 1.0). The resistance of suspensions of normal red cells varies remarkably little. 3

In 6 cases of clinically ascertained pernicious anemia in relapse, we have found the red cell resistance to saponin to be greatly decreased, so that the time-dilution curve for the abnormal blood rises to an asymptote much higher than that for the normal blood. Frequently the 2 curves cross each other, as shown in Fig. 1, curves A and C, the times for complete lysis in high lysin concentrations being longer for the abnormal blood than for the normal, but the times in higher dilutions of lysin being very much shorter for the abnormal cells.

Cod liver oil has been used from time immemorial by fisher folk for the treatment of external wounds, and it has long been recommended for the treatment of tuberculosis. Löhr, 1 studying the wound healing properties of cod liver oil in various types of wounds, reported that this oil would aid in the healing of lupus. Our interest in the influence of cod liver oil on tuberculous lesions was especially aroused by the report of its successful use in the treatment of 3 cases of lupus by Banyai. 2

Our purpose was (1) to confirm, if possible, the clinical observations on man by studying the effect of cod liver oil on tuberculous skin ulcers in guinea pigs, and if the results should prove favorable, (2) to isolate the chemical fraction in the oil responsible for the healing action, (3) to study its effect on other types of experimental tuberculosis, and (4) if these experiments should be satisfactory, then to determine the effect of the “pure substance” in human tuberculosis.

Tuberculous skin ulcers were produced by the intracutaneous injection of 0.2 mg of virulent tubercle bacilli (H37) and treated topically twice daily with a few drops of cod liver oil. Our first experiment, using 24 animals, verified the clinical observations in that the lesions in the treated animals healed more rapidly than those in the controls. Each animal received 3 cc of the bacterial suspension standardized by the method of Breed and Breed as given by Baldwin. 3 At 2 weeks induration was noted; ulcers approximately 1 cm in diameter were present at 3-4 weeks. Treatment was started on the 28th day of infection and lasted until the lesions were closed or until the experiment was terminated 30-40 days later.

Although Bohn and Hahn found pressor substances in hypertension and Bain found this material only in the normal, the results of these experiments indicated that no significant differences in the amount of pressor substances, other than possible normal variations, existed between the urine of normal individuals and the urine of the 2 essential hypertensive individuals that were tested. Furthermore, the normal dog was found to excrete pressor substances in variable quantities.

Van Slyke and Hiller 1 reported evidence that the phosphotungstate precipitate obtained from hydrolyzed gelatin contained amino acid material other than the hexone bases usually found in this precipitate. Other problems prevented continuance of work on the isolation of the material. It was taken up by Van Slyke and Robson 2 but after preparation of a copper salt, since found to be contaminated with proline, the work was again discontinued by Robson's return to England.

The unidentified base has now been isolated and recrystallized, both as the picrate and as the hydrochloride, and has the composition of a hydroxylysine. After removal of arginine and histidine as silver salts the residual “lysine fraction” is freed of adherent mono-amino acids by repeated precipitation in very dilute solution as phosphotungstate. The greater part of the lysine is removed by addition of enough picric acid to the hot aqueous solution to combine with 3/4 of the amino nitrogen present. To the mother liquors enough more picric acid is then added to combine with the rest of the amino nitrogen. A picrate of the composition C₆H₁₄N₂O₃. C₆H₃N₃O₇ is crystallized, from a dilution of about 1 to 10, and is purified by recrystallization. It is more soluble than the picrate of lysine, and when heated at the rate of a degree every 3 seconds shows a melting point at 225°. Both the nitrogens of the amino acid react completely with nitrous acid in 10 minutes. There is a marked difference from lysine in speed of reaction; in 3 minutes at 25 under the conditions of the manometric analysis 3 lysine evolves only 83% of its total nitrogen, while the new base in the same time evolves 95%.

Spontaneous contractions of the postpartum dog uterus or the diestrous uterus of the guinea pig may be augmented by the administration of calcium or depressed or completely inhibited by diminishing the available calcium. In the latter instance the uterus is usually not only quiescent, but is also relatively refractory to pitocin.

Since the first report of ovulation induced during the non-breeding season in Rana pipiens by homoplastic anterior pituitary transplants, 1 this species has been used repeatedly for demonstrating and studying this reaction. 2 This form will also ovulate after treatment with pituitaries of other species of Rana, e.g., R. sphenocephala, etc., 3 and of fish, Lepidosteus, 4 and with beef pituitary extract (phyone). 5 There is, however, the report that “mammalian pituitary extract, whole sheep pituitary, and the Antuitrin-S from pregnant human female urine have proven to be entirely ineffectual in respect to ovulation in Rana pipiens” (p. 29 6 ) and more recently negative results followed the use of pregnant mare's serum, Antuitrin-S, beef anterior lobe extract, Antuitrin, live implants and macerated injections of whole glands from fishes (Perca flavescens, Cristovomer nanaycush, Stizostedion vitreum) and from Necturus even when very large doses were used. 7

Because of this apparent refractoriness of Rana pipiens to hetero-plastic anterior pituitary treatment, tests were made in which whole pituitaries of Triturus viridescens were injected into the body cavities of females while others received equivalent amounts of homoplastic pars anterior. In a preliminary test made in December, 1937, in which 4 anterior pituitaries from male Rana Pipiens and 8 whole pituitaries of Triturus viridescens, respectively, were implanted into 2 animals, no ovulation occurred, so larger doses were employed in the succeeding experiments.

In the normal animal lymphoid tissues have been found to be more susceptible than other tissues to the action of colchicine. 1 2 Waves of mitoses and pyknoses are found in the thymus, spleen, lymph nodes and Peyer's patches following its administration in proper doses (Dustin's “caryoclasic shock”). The action of colchicine and certain other nuclear poisons is similar to that of X and gamma radiations, which led Dustin to refer to their effect as “radio-mimetic”. It thus seemed quite logical to test the action of this drug on a lymphoid tumor since (1) normal lymphoid tissue is so extremely sensitive to caryoclasic phenomena and (2) since other investigators were able to obtain regression of other types of tumors using this alkaloid. 3 4 5 6 7

Mice of the C3H strain were used in this investigation. After a line of leukemia had been carried for 3 transplant generations experiments with colchicine were begun.§ When a piece of lcukemic lymphoid tissue was implanted in the right axilla a large local growth formed previous to the appearance of systemic leukemia. The systemic disease did not appear until after 23 days'growth of the transplanted tumor. By 14 days the growth was the size of a kidney bean. If, at this time, 1/40 mg of colchicine in distilled water was administered subcutaneously every third day at a site far removed from the tumor the local growth practically disappeared. Average survival time of controls after transplantation was 31.5 days as compared with 50.5 days survival in treated animals (see Table I—14 test animals and 13 controls).∗∗ Life was significantly prolonged in 7 of the 14 treated mice (6 out of 8 where the drug was administered in 0.1 cc rather than 0.5 cc distilled water-see table).

We extract the porphyrins from urine, bile and feces by prolonged extraction with acetic acid-ether (Fink and Hoerburger, 1 Fikentscher, 2 Van den Bergh and others, 3 Brugsch 4 ). Uroporphyrin is lost but, according to Fischer and Zerweck, 5 this may be neglected except in extremely rare cases. The porphyrins are taken up by 5% HCl from the crude ether extract. Purification involves repetition of the transfer to ether and back to HCl. Phylloerythrin requires 10% HCl. Total porphyrin is estimated in 5% HCl by the intensity of the red fluorescence excited by ultraviolet light. Pure copro- or hematoporphyrin solution is used for standardization. Recovery of known amounts of pure porphyrins in 12 series of determinations averaged: coproporphyrin, 100%; hemato-porphyrin, 104%; mesoporphyrin, 97%; protoporphyrin, 103%.

Quantitative fractionation of the porphyrins is done by successive extractions of the purified ethereal solution with 1 volume 0.25% HCl to 3 volumes ether. Three such extractions remove all the coproporphyrin (and hemato-porphyrin which, however, does not occur naturally), 62% of the mesoporphyrin, 10% of the protoporphyrin, and about 49% of the deuteroporphyrin.

These results on pure porphyrins apply also to mixtures. Quantitative estimates of copro- and protoporphyrin in known mixtures are precise within ±3% of the total; similar mixtures of copro- or proto- with mesoporphyrin were separated with an error no greater than ±6%.

This work grew out of previous studies showing that ischemia of the functioning heart leads to a marked rise in the potassium content of the coronary venous blood. 1 This report is concerned primarily with the effects produced in anesthetized dogs on clamping off the tracheal cannula for periods of from 2 to 4 minutes. Twelve dogs anesthetized with nembutal were used. In half the dogs only one asphyxial period was produced, in the others 2 or more were obtained. Blood was drawn from the external jugular vein in 10 of the dogs. In 2 dogs the chest was opened and artificial respiration administered, the blood being obtained from the superior cava in one and from the right auricle in the other. The method of Breh and Gaebler 2 was used in the potassium determinations, the analysis being completed by the diazotization procedure of Briggs. 3 The condition of the blood samples was unknown to the analyst, since they were given blind numbers when they were drawn.

The results are given in Table I. They show that during asphyxia the plasma potassium increases 22% and the whole blood potassium 16% over the normal control values. There is an increase of 43% for the plasma and 14% for the whole blood potassium during a second asphyxial period, as compared to its control taken immediately before. The second asphyxial period was produced from 10 to 20 minutes after the first one.

These figures show the increase in blood potassium during asphyxia. Data on the effects of over-ventilation are as yet inconclusive. Fenn has shown that muscular activity causes a decrease in muscle potassium. 4 Presumably this would be accompanied by an increase in blood potassium. Producing in the anesthetized dog by reducing the cerebrospinal fluid calcium ions or increasing the potassium ions in the cerebrospinal fluid, 5 has caused a rise in blood potassium in some experiments we have recently performed.

The principle of the photoelectric plethysmograph 1 has been applied to the comparison of the richness of the blood supply in several skin areas. Vertical illumination of the skin is provided by an ophthalmoscope bulb. Enough light is scattered through the subcutaneum to provide a sufficiently satisfactory transillumination to permit the detection of changes in the circulation in the skin by a photoelectric cell placed over the transilluminated area. The variations in the photoelectric current with changes in the blood content of the skin are recorded on the electrocardiograph after amplification.

The volume pulse of the skin so recorded probably is an index of the arterial inflow with each heart beat and so can be used as an index of the blood supply of that skin area. (Special hemodynamic conditions will, of course, limit the specific application of the statement). Arterial constriction in the skin decreases the volume pulse; vasodilatation increases it. The amplitude and form of the recorded wave will also vary with the size and number of arterial vessels in the transilluminated area.

Quantitation of the recorded wave in terms of arbitrary units is effected by comparing the size of the wave with the deflection obtained from inserting a glass filter (a thin glass sheet) between the photoelectric cell and the transilluminated skin area. Although the question as to what is the actual blood equivalent of the filter in terms of cc of blood per 100 cc of skin tissue is an involved one, 1 a tentative approach to the problem is provided in the data of Turner, et al. 2 Their average volume pulse in the finger tip at heart level is 2.8 mm³ or .06% of the soft tissue volume.

A fall in blood sugar in dogs has been demonstrated following cathode iontophoresis with insulin.

The effects on blood pressure and respiration produced in cats and dogs under morphine-urethane, nembutal and chloralose anesthesias, by intravenous injections of thio-acetyl choline chloride, thio-acetyl-gamma-homo-choline chloride and thio-acetyl-beta-methyl choline chloride have been observed and recorded.∗ Eighteen animals (10 cats and 8 dogs) have been used in these experiments. Records were taken of the results of over 200 injections, of which approximately one-third was of each of the 3 compounds. The results of the administration of each compound were constant.

Thio-acetyl-choline chloride and thio-acetyl-gamma-homo choline chloride are almost identical in their effects. Immediately following injection the blood pressure falls slightly, then rises rapidly to 60 to 90 mm Hg above the normal level. During this rapid rise the heart rate increases but upon reaching the peak pressure the rate slows and large vagal beats appear. The duration of this bradycardia varies from one to 5 minutes depending upon the amount of the compound injected. During this period the blood pressure gradually falls to normal, which level is reached in 2 to 10 minutes. Hyperpnea of short duration immediately follows injection. This hyperpnea is followed by depression with gradual return to normal.

Thio-acetyl-beta-methyl choline chloride produces a moderate depressor action but has no effect upon the respiration. B.P. falls 30-50 mm Hg and is not accompanied by changes in heart rate.

The minimum effective dose is of the order of .016 mg/kg. When larger dosages are used (.5-1 mg/kg) the animals rapidly pass into a fatal apnea.

Atropine sulphate abolishes neither the pressor response nor the hyperpnea caused by thio-acetyl choline chloride and thio-acetyl-gamma-homo choline chloride, but eliminates the bradycardia. The depressor action of thio-acetyl-beta-methyl choline chloride is abolished by atropine. Physostigmine does not augment the action of any of these compounds

The writer has previously demonstrated that crystalline insulin 1 can be attenuated by interfacial adsorption. In the same communication reference was made to the fact that bacterial toxins can also be attenuated by a similar procedure. It has been found by additional experimentation that ricin, tetanus toxin, staphylococcus toxin and snake venom may be completely detoxified by this method and still retain antigenic properties adequate for purposes of immunization, as demonstrated with rabbits and mice. The following data are representative of the results which have been obtained.

“C.P. ricin” which will produce a pronounced erythema, induration and necrosis when 0.2 cc of a solution of 1 part of ricin in 25,000,000 parts of saline are injected intradermally into rabbits will produce only a faint erythema when equal volumes of the same ricin in dilutions of 1 part of ricin in 1,000 parts of saline are injected after 2 treatments of 48 hours each with chloroform. When triple injections of untreated ricin in dilutions of 1 part ricin in 1,000,000 parts of saline were injected intradermally into rabbits which had been immunized with completely detoxified ricin, only a faint erythema was produced at the site of each injection.

When the serum of each immunized rabbit was mixed with an equal volume of a solution of ricin containing 1 part of ricin in 200,000 parts of saline, and the mixture (0.2 cc) injected intradermally into normal rabbits, no symptoms of any kind were produced.

Tetanus toxin† containing 70,000 (guinea pig) M.L.D.'s per cc was completely detoxified when treated twice for 48 hours by interfacial adsorption. Five cc of the detoxified toxin produced no symptoms of any kind when injected subcutaneously into guinea pigs. Groups of mice (50 each) treated with the detoxified toxin all survived this treatment and smaller groups of these subsequently survived injections of 1 and 2 M.L.D.'s of untreated toxin without symptoms of tetany.

Although it has been shown recently that the air of hospital wards contains beta hemolytic streptococci of the same serological types as those infecting patients in the same wards 5 , 6 it should be emphasized that the strains reported on here came from air breathed by the city population at large. Though our findings indicate that group A streptococci are relatively rare in normal air sampled at random, it is of great interest that, by the tests applied, they are indistinguishable from similar organisms isolated directly from disease processes. Furthermore, it should be noted that 88% of the strains in this small series were of the human pathogenic group A.

It has been estimated by several investigators 7 , 8 , 9 that group A hemolytic streptococci are present in from 3 to 7% of normal throats. None have reported as high a percentage of group A cultures among the hemolytic streptococci of the throat as was found in this series of air streptococci. It is possible that the percentage of group A cultures of air was augmented by the coughing of individuals with group A infections of the throat.

The presence of group A streptococci does not necessarily indicate that they were suspended in droplets in air, for, as shown by studies of hospital air 5 , 6 and as has been demonstrated experimentally by Wells and in this laboratory, bacteria sprayed in air may float for many hours after all droplets have evaporated. In conclusion we agree with Brown and Allison who, after studying the streptococci in the air of scarlet-fever wards, stated, ". . . . and while contact, direct or indirect, is probably of considerable importance in the transmission of infection the possibility of infection via the air other than that due to droplets cannot be dismissed."

Thanks are due to Dr. Beatrice C. Seegal for her interest and assistance as well as to Dr. Rebecca C. Lancefield for a generous contribution of group serums.

Silver compounds are employed for their antiseptic and germicidal action on bacteria. The effectiveness of such preparations is due largely to the free silver ions. The higher the concentration of free ions the greater will be the germicidal effect. New and Nonofficial Remedies (1937) states, “The antiseptic action of silver nitrate is complicated by irritation, pain, astringency, and corrosion. These may be desirable for the destruction of tissue or the stimulation of indolent wounds; but when they are not necessary for such purposes, they are distinctly undesirable. They may be avoided by the use of colloidal silver preparations.”

The colloidal preparations differ from the silver compounds in that the silver does not exist to any great extent in the form of free ions. The silver does not, therefore, precipitate chlorides or proteins and is noncorrosive and relatively nonastringent and nonirritating. The germicidal action is not proportional to the silver content of the preparations but is due to the liberation of very low concentrations of silver ions. The degree of ionization or liberation of silver ions varies with different preparations.

In an earlier paper 1 a new method was proposed for the evaluation of germicidal substances. The compounds were tested for their effect on the growth of living embryonic chick tissue as well as for their ability to kill bacteria. A number known as the toxicity-index was determined which is defined as the ratio of the highest dilution of disinfectant showing no growth of embryonic tissue in 10 minutes to the highest dilution required to kill the test organism in the same period of time. The tests were run at a temperature of 37°C in the presence of a standard amount of organic matter.

Under the conditions of our experiments, Prontylin exerted no beneficial effect in experimental tuberculosis.

Resistance to tuberculosis, as measured by survival-time of guinea pigs after intracerebral inoculation, varies with age. Young animals are the more resistant, and susceptibility increases progressively with age.

Some of the difficulties encountered in treating diabetes could be attributed to rapidly fluctuating blood sugar levels. The slow acceptance of protamine zinc insulin by the clinician was, in part, due to the occurrence of hypoglycemia episodes. They can be differentiated into two groups, the nocturnal, and the post-prandial. The former are obviously due to the unopposed prolonged action of Prozinsulin during the long fast from the evening meal to breakfast. An explanation for the latter type is given below.

Fifty-two diabetic patients using protamine zinc insulin exclusively for routine control were selected at random for the experiment. This consisted in the administration of 210 g to 420 g of orange juice, (25 to 50 g of glucose) 24 hours after the last insulin injection. Blood sugar estimations were made by the Somogyi (1936) modification of the Shaffer-Hartmann method in the fasting state, and at 0.5-hour intervals for 4 hours. The results shown in Table I with the controls, represent illustrative types of blood sugar variations seen in this series of experiments.

It is evident that the peak rise in the first 0.5 to 1.0 hr and the subsequent fall to fasting, or below fasting levels by the 3.0 hr resembles the normal glucose tolerance curve. In fact, many of the curves cannot be distinguished both in absolute change and contour from non-diabetic ones. Another point to be noted is that the rapidity of the rise has a direct bearing on the rate of fall, independent of the original blood sugar level. That is, the sharpest peak rise in blood sugar level is followed by the most precipitous drop. During the test period, patients with such curves manifested hypoglycemic symptoms. It will be noted that in the control curves where no food was given to the patient, the blood sugar level remained essentially unchanged for the 4-hr- period. It must be assumed that the amount of exogenous insulin present was the same both in the test period after orange juice, and in the control period.

1. There was no apparent relation between arterio-venous blood sugar differences and the following: period of time following milking, arterial blood sugar level and level of milk production. 2. Both glucose and lactic acid are absorbed by the lactating mammary gland in considerable quantities. While the glucose arterio-venous loss is not sufficient to account for all of the milk sugar, the combined loss of the two substances to the lactating mammary gland can account for all of the milk lactose.

Stimulation of the reproductive tracts of infantile female mice has been brought about by the administration of large amounts of fresh anterior pituitary from Rana Pipiens. It is believed that this is the first time precocious sexual maturity has been caused in the mammal by anuran pars anterior.

Under normal resting states the concentration of lactic acid in venous blood of normal human beings varies from 10 to 20 mg per 100 cc of blood where the Friedman Contonio and Shaffer method is used. (Peters and Van Slyke). 1 When normal individuals are submitted to mild exercise∗ a slight rise of the lactic acid concentration above the resting level occurs. (Table I.) The average concentration of the lactic acid values was 13.9 mg per 100 cc at rest while after mild exercise it rose to 16.3 mg per 100 cc of blood, an average increase of slightly more than 2 mg per 100 cc. In no instance did the lactic acid concentration exceed 21 mg %. In these 11 cases the hemoglobin concentration and red blood counts were in the normal range.

In Table II we have recorded the resting and post exercise values of the blood lactic acid in 5 normal individuals with high hemoglobin and red counts including one diabetic with a high hemoglobin and red blood count. Excluding the latter the average resting value as well as the average values following exercise are higher than those in the normal range. As in normals a slight but definite rise in the lactic acid concentration takes place, going from an average resting value of 15 mg% to 17.3 mg%, an average increase of slightly over 2 mg%. From this it is evident that normal individuals with high hemoglobin contents and high red blood counts show essentially the same lactic acid response to exercise as normal individuals.

A considerable degree of pulmonary collapse can be maintained in man with very little alteration of respiratory function other than an abnormal amount of hyperventilation on exertion. Latent physiological abnormalities usually become manifest clinically only under stress. The response to exercise is too dependent upon physical fitness to be a reliable guide to the capacity of an individual to compensate for a reduction of lung volume. Since oxygen lack constitutes the greatest danger to patients who have disorders of respiration, the oxygen saturation of the arterial blood while breathing a mixture of gases containing less oxygen than the atmosphere would seem to furnish a simple and quantitative test of one phase of respiratory efficiency while the subject remains at rest.

The procedure consists in the analysis of the alveolar air and arterial blood while the subject breathes room air and again while he breathes from a Douglas bag containing about 16% oxygen in nitrogen. By this means it is possible to ascertain the degree of arterial saturation produced by the observed alveolar oxygen tension. Alveolar air was withdrawn in 1 or 2 cc portions from the axial stream in the center of the mouthpiece of a set of respiration valves at the end of successive expirations until 40 cc or more were obtained. This is essentially a modification of the method of Krogh and Lindhard 1 which was shown by Debenham and Poulton 2 to give results which agree with Haldane-Priestley samples. Air analyses were done in the Haldane-Henderson apparatus.

Arterial puncture is often painful and frequently causes patients to hold their breath or hyperventilate, and full reliance cannot always be placed upon the analysis of blood obtained by this means. 3 Since 2 samples of blood are taken within a few minutes of each other in this procedure, the method of Goldschmidt and Light 3 was used.

Eastern equine encephalomyelitic (E.E.E.) virus, injected into the leg muscles of 15- to 21-day-old mice, invades the central nervous system (CNS) along the local peripheral nerves in only about 5% of the animals, while in most of the others it appears to be eliminated from the blood onto the olfactory mucosa, invading the CNS by the olfactory pathway, and when that pathway is blocked by preliminary chemical treatment of the nasal mucosa most, but not all, of the animals escape CNS involvement. 1 Further study by the method of partial serial sections of the entire CNS 2 revealed that when mice, given the virus intranasally, succumb in spite of the chemical treatment, the lesions are still distributed along the olfactory pathways and connections, showing that the treatment did not provide a complete barrier. When, however, mice receiving the virus intramuscularly succumb in spite of chemical blockade of the olfactory pathway, the localization of lesions indicates that the CNS was invaded by other pathways, the following types having been encountered: (a) lesions limited to the spinal cord and medulla, indicative of spread via the nerves supplying the inoculated muscle; (b) lesions involving chiefly the cochlear ganglion of one side and the inferior colliculus and medial geniculate body of the opposite side (i.e., a unilateral involvement of the auditory pathway and its central connections); and (c) lesions limited to a focus in the vicinity of the medullary nucleus of the 7th nerve. Hence, these and other pathways may occasionally be utilized by virus injected into the leg muscles (and also intraäbdominally) of normal mice as well as of those with chemical blockade of the olfactory pathway. In one normal young mouse injected intraäbdominally with E.E.E. virus both the auditory and vestibular pathways appeared to be involved. It is remarkable, however, that in these mice the localization of lesions practically always corresponded to some definite pathway, suggesting that the virus was set free in one focus from which it spread along the nervous pathways connected with it (excepting the olfactory pathway, there is as yet no evidence to indicate whether that focus is within or outside the CNS) rather than liberated indiscriminately throughout the CNS.

Studies of the conditions which permit or prevent the viruses of vesicular stomatitis and equine encephalomyelitis to invade the CNS of mice and guinea pigs have thus far disclosed that depending upon the age or species of the host there may be changes or variations in localized sites, e.g., in terminal, specialized nerve endings, in special areas of the CNS, blood vessels, etc., which can prevent the virus from invading or progressing in the CNS—changes in different tissues functioning as barriers for different viruses depending upon the mode of CNS invasion utilized by the virus.

Testosterone propionate inhibits the skeletal changes (pubic resorption and hypercalcification of the skeleton) which occur when estrogens are injected over extended periods.