Experimental Biology and Medicine

The acid hydrolysis method of measuring urea has been revised so that it will furnish accurate and reliable results when applied to either whole or cell-free blood.

1. A striking change is noted in the electrophoretic pattern of the serum in nephrotic patients soon after diuresis induced by ACTH, or ACTH plus urea. The pattern which is characteristic of nephrotic serum (low albumin and large, unresolved α_2. and β_3. globulin peaks) reverts toward the normal after diuresis. The serum albumin rises sharply and the α_2. and β_3. globulin region shows clear resolution. 2. Possible explanations of these abrupt changes in the electrophoretic patterns and concentrations of serum proteins are discussed.

1. The daily injection of 50 mg/kg of sodium acetoacetate into normal rabbits in increasing doses markedly increased the blood lactate level to an average of 36.7 mg/100 cc (control = 7.9 mg/100 cc) after 90 days. 2. In a second group of animals receiving about half the dosage, the plasma ascorbic acid decreased from 2.50 to 0.83 mg/100 cc after 60 days. 3. Simultaneous injection of amellin prevented the accumulation of blood lactate. In animals which had received sodium acetoacetate for 90 days, amellin restored the blood lactate level to normal within 40 days, in spite of the continued injection of increasing amounts of the acetoacetate. 4. In an experiment otherwise identical, insulin was not as effective as amellin; when it was injected, the blood lactate diminished initially but later increased. 5. The amellin treated animals were healthier than the insulin treated ones.

Some of the variables involved in the production of high titer phage stocks by the agar layer method have been investigated using coli phage T4r as an example. The significant factors have been shown to be the number of virus particles and the number of bacteria inoculated per plate, the length of incubation, the volume of soft agar in the agar layer and the volume of broth used for extraction of the virus from the agar. By an appropriate adjustment of these variable factors it is possible to obtain stocks of the various coli phages of the T series ranging from 10¹¹ to 10¹² infectious particles/ml.

(1) Chronic folic acid deficiency was induced in rats with a highly purified diet containing 1% streptomycin. (2) Xanthopterin causes a small increase in the number of erythrocytes but does not alter the color index or leukopenia. (3) P-aminobenzoylglutamic acid has no effect on the hematological picture resulting from a chronic deficiency of folic acid in the rat. (4) The simultaneous parenteral administration of amounts of xanthopterin and p-amino-benzoylglutamic acid in the same molecular ratio existing in folic acid, has a complete and specific therapeutic activity almost as rapid as that of folic acid. (5) This indicates that rats can synthesize folic acid from simultaneously administered xanthopterin and p-aminobenzoylglutamic acid.

(1) An accurate procedure is presented for the determination of chloride in small samples of cerebral tissue. (2) Cerebral edema did not occur in rats subjected tobilateral nephrectomy, nor was there any increase in brain chloride concentration. (3) After nephrectomy, the serum chloride of rats falls markedly.

d-Biotinol does not replace d-biotin in the nutrition of L. arabinosus, L. casei, or S. cerevisiae but is fully as effectiveas d-ibiotin in curing egg white-induced bio tin deficiency in the rat. Comparison of urinary excretions of biotin after oral or intramuscular administration of biotin and biotinol shows the latter to be converted to biotin efficiently by both rat and human.

A systematic evaluation of cutaneous, dental and visceral pain before and during the administration of either cortisone or ACTH demonstrated that these agents had no analgesic effect at therapeutic dose levels. The marked alteration in the host reaction to inflammation during treatment with cortisone or ACTH probably is the principal factor responsible for the alleviation of pain.

Immature rats were fed a purified ration containing all the known B vitamins in synthetic form and a similar diet with pyridoxine omitted. Tests were conducted in which rats fed the above diets were exposed to cold (2 ± 1.5°C) from the first day of feeding or after an experimental period of 80 days. 68.8% of the pyridoxine-deficient rats in the latter group succumbed during a 20 day period of cold exposure in contrast to a 0% mortality for animals fed a similar diet supplemented with pyridoxine hydrochloride. In the group exposed to cold from the first day of feeding mortality was 25.0% and 18.7% respectively for rats fed the pyridoxine-deficient and control ration for a period of 100 days.

Specific complement-fixing antigens were prepared from cotton rat tissues infected with Lansing poliomyelitis, rabies, and St. Louis encephalitis viruses. The antigens were prepared by concentration of the viruses through high speed centrifugation. Lansing antigens prepared from lyophilized tissues were of little value as CF antigens.

A relatively rapid rise and fall in poliomyelitis complement-fixing antibody levels in cotton rats is described. The Lansing antigen fixed complement with serum from Lansing-immune monkeys, but not with serum frommonkeys similarly immunized against Brun-hilde and Leon viruses.

Prior administration of beef adrenal extract increased the resistance of mice, particularly male mice, to semi-lethal doses of arsenite, oxophenarsine and clorarsen. Male mice were protected against arsenite by cortisone and ACTH, but not by desoxycorti-costerone. Prior administration of cortisone did not increase the resistance of mice to semi-lethal doses of p-chloromercuribenzoate, iodo-acetamide, alphapeltatin, or 9-phenyl-9-chlor-10-methyl-3-dimethyl amino acridan. The minimum dose of arsenite required to induce marked hemorrhagic necrosis in mouse Sarcoma 37 was somewhat greater for adrenal extract or cortisone injected mice than for control mice.

Protamine zinc insulin administered to 51 pregnant albino rats throughout pregnancy in doses 7 and 8 units daily (nearly the maximum dose tolerated) had significant effects on fetal development. Compared with fetuses of untreated normal control rats, the average weight of the fetuses of the insulin-treated rats was lower, and the number in each litter was less owing to fetal deaths and resorption. Mild skeletal abnormalities were found, many of the fetuses showing a decreased number or complete absence of ossification centers in the sternum, a few showing some irregularities in shape and staining of the ribs and long bones.

1. Plasma volumes can be accurately determined by the radioactive (1-131) iodinated plasma protein method in nutritional hypoproteinemia. 2. The rate of disappearance of radioactive protein from the blood stream is the same in undernourished states as in normal and therefore cannot be utilized to determine the state of the protein reserves of the body. (3). In patients who are losing abnormal amounts of protein in the urine or into abscess cavities, the rate of disappearance appears to be increased. The use of radioactive serum albumin may offer a diagnostic aid in the detection of unexplained protein losses.

(1) S-phenylamino-9-dialkyl-aminobenzo[a]phenoxazine dyes stained fat in vivo when administered to mice in their food. (2) The fat staining properties of the dyes were not materially altered by substituents on the phenyl nucleus other than those of highly acidic nature, or by substitutions of the naphthyl group and certain nitrogen heterocyclic rings for the phenyl group. The 5-phenylamino-9-morpholinyl derivatives also stained fat in vivo. (3) S-benzylamino-9-di-methylamino- and diethylaminobenzo[a]phenoxazine dyes did not stain fat in vivo, al-though they did stain tumor tissue. The corresponding dyes in which the alkyl group on the 9-nitrogen contained more than 2 carbon atoms stained fat in vivo. These dyes also stained tumor tissue in vivo.

These investigations imply that emotional disorders are accompanied by changes in protein metabolism and adrenal activity. The protein metabolic disturbances are generally in the direction of increased catabolism. being well correlated with emotional response when the disorder is essentially an anxiety reaction to acute stress, less well correlated in schizophrenic psychosis, but sometimes still pronounced and, finally, lacking in correlation in the presence of conversion hysteria. Furthermore, a comparison of schizophrenic psychotics with normal controls reveals that the former exhibit a generally higher and more variable state of adrenal activity. It is hoped that these ostensibly unrelated sets of data may eventually become integrated with a coherent concept of individual reactions to stress.

This method offers a simple quick technic for separate expired air samples. Both CO₂ and O₂ analysis may be completed within 5 minutes as compared to 15-20 minutes by Haldane. Ninety-five per cent of the duplicate CO₂ analyses as determined with the Beckman C model (110-160 mm Hg range) will agree within 0.10% with duplicate Haldane data. A Beckman instrument of a narrower range and/or greater sensitivity would improve this accuracy. In our experience the Beckman C model (110-160 mm Hg range) allows better results than does the more elaborate and expensive E-2 model.

Suspensions of mitochondria of various transplanted mouse tumors are able to oxidize pyruvic acid if the system, containing Mg ions, ATP, cytochrome C, and priming concentrations of fumarate, is fortified with diphosphopyridine nucleotide. The concentration of the nucleotide required for maximal activation is 0.002M. When mitochondria of tumors were compared with those of normal tissues it was found that on a per mg nitrogen basis pyruvate oxidation was similar in magnitude in both types of mitochondria.

Evidence is presented to show the metabolism of OPG to glucose by the phloriznized starved dog.

(1) A spectrophotometric method has been developed for the determination of nicotinaldehyde thiosemicarbazone in blood. (2) Following single oral doses of 200 mg/kg in dogs, the maximum blood concentration achieved by nicotinaldehyde thiosemicarbazone was ten to forty times greater than that of p-acetylaminobenzaldehyde thiosemicarbazone. (3) Following the chronic daily oral ingestion of 0.05% of these drugs in the diet of rats? the average blood concentration attained by nicotinaldehyde thiosemicarbazone was approximately 10 times that attained by p-acetylaminobenzaldehyde thiosemicarbazone.

Analyses of plasma and tissue water and electrolytes content were made in intact and adrenalectomized groups of rats untreated and 60 minutes after epinephrine injection. Evidence was presented that the plasma potassium concentration was significantly decreased in intact and adrenalectomized rats after epinephrine compared to their respective controls. The potassium content of muscle tissue was significantly decreased in the epinephrine treated intact and adrenalectomized groups. There was no change in the water, sodium or chloride concentration of plasma after epinephrine in either intact or adrenalectomized groups. However, there was a significant decrease in intracellular water content and increase in extracellular water content which was briefly discussed as linked to the change in potassium content. None of these changes were determined in liver tissue of the intact or adrenalectomized groups 60 minutes subsequent to epinephrine injection. In view of the above results and the evidence that the sodium and chloride content of muscle of the intact group was significantly increased after epinephrine but not so in the adrenalectomized group, the results were briefly discussed as evidence of an effect of epinephrine on the potassium “balance” in the compartments of the organism.

In cats curarized with dihydro-beta erythroidin hydrobromide and under artificial respiration, changing from air to mixtures of 3 to 10% CO₂ in oxygen caused no significant change in the percentages of fast, intermediate and slow waves in the electroencephalographic spectrum. It is concluded that artificial respiration as used in experiments with curarizing drugs does not distort the frequency spectrum.

Cataract was produced experimentally in weanling littermate rats by (1) alloxan treatment, (2) galactose feeding, and (3) xylose feeding. All groups showed greatly elevated blood sugar levels as compared with untreated controls receiving glucose. Cataract was exhibited by all of the xylose- and galac-tose-fed rats, and by nearly all of the alloxan-treated rats. However, the development of cataract was much slower in the alloxan-treated than in the other groups. It is concluded that not only the level of blood sugar, but also the specific configuration of the sugar concerned is a factor in its cataractogenic action.

The compounds, 3–chloromer–curi–2–methoxypropylurea (1347Ex), 3–car–boxymethylmercaptomercuri − 2 – methoxypro–pylurea (1353 Ex), and. 3 – (α–carboxye thylmer–captomercuri) − 2 –methoxypropylurea (1431–Ex), had 3 or 4 times the diuretic potency of meralluride in the dog. Twenty–four and 48 hour mercury excretion rates were comparable to that of meralluride at the same dosage level. Chronic toxicity studies indicated no essential difference between meralluride and the other compounds, if the greater diuretic potency of the new compounds was considered and the dosage adjusted accordingly. Large amounts of 1353Ex and 1431 Ex were infused intravenously without disturbing cardiac function, but the acute cardiac toxicity of 1347Ex, although greater than the other 2 compounds, appeared to be less than meralluride.

(1) Fertilized eggs of the leopard frog, Rana pipiens, were exposed to solutions of radiophosphorus of different activities (65, 300 and 550 microcuries). (2) Auto-radiographs and microphotographs were prepared from whole and sectioned embryos in 7 different stages of development. (3) Auto-radiographs show that the uptake of phosphorus³² is greatest in embryos exposed to the most active solutions and also that the process is a cumulative one, increasing with the age of the embryo. (4) The most active areas of the embryo in each of the stages studied are those areas where cell division is high and the population of cells is largest. (5) With the appearance and differentiation of organ primordia, the rate of phosphorus turnover increases, thus indicating that phosphorus is probably being utilized more rapidly in those areas in the synthesis of nucleoproteins.

3,4-dihydroxyanthranilic acid was not converted to quinolinic acid or nicotinic acid by rat or hog liver preparations. Spectrophotometric evidence indicates that this compound is not the transient intermediate formed in the conversion of 3-hydroxyanthranilic to quinolinic acid by liver enzymes. It was not utilized by Xantho-monas pruni for growth, or by the rat for growth or formation of urinary nicotinic acid or quinolinic acid.

The observation that exposure to X irradiation causes partial dissolution of cell spindles and that chromosomes in the destroyed area become pycnotic led to this study of the living spindle. Photographs of grasshopper testis, living cells that have been immersed in Belar solution show spindle fibers and the attachment of some of these fibers from the centrosome to the chromosome. The reality of the spindle in fixed tissue, as revealed by phase contrast microscopy, is emphasized as a result of these studies. Prior to this experiment, Schmitt and Belar were also able to show the birefringence of spindle fibers.

Intracellular organisms resembling Histoplasma capsulatum have been observed in apparently normal amnio-allantoic membrane and adult horse spleen maintained in tissue culture.

The significance of this finding and comparison with another fungus Cryptococcus jarciminosus is discussed.

Experiments are reported showing that the cooking of whole wheat as in the preparation of shredded wheat results in a significant improvement in the nutritional value of the whole wheat. This improvement is not lost when the material is fan-dried or oven-dried in the preparation of shredded wheat.

A study of factors influencing citrate synthesis was conducted using the fluoroacetate technique of Potter(2) to determine the cause of the marked sex difference (1) in citrate accumulation in the liver following administration of fluoroacetate to rats. Castration of female rats did not decrease citrate synthesis in the liver but castrated and adrenalectomized male rats acquired the ability to accumulate citric acid in the liver after fluoroacetate treatment. Administration of testosterone to female rats for several days decreased citrate synthesis in the liver and testosterone inhibited citrate synthesis by rat liver homogenates in vitro. The results of these experiments indicated that androgens suppress citrate formation in the liver.

(1) The fecal excretion of orally administered Ca⁴⁵ is a sensitive indication of the calcium status of the rat; (2) placing normal rats on a low calcium diet for as little as 2 days greatly increased their ability to absorb Ca⁴⁵ from the tract; (3) the specific activity of labeled calcium at the site of absorption had little effect upon its absorption; (4) in general, younger rats absorbed more Ca⁴⁵ than did older ones although there was no significant difference between 6 1/2 and 16-month-old animals; (5) for meaningful studies of this type, interpretations must include consideration of exchange reactions, and care must be given to initial selection of diets and animals, preparation of animals for the experiment, and dietary management during the experimental period.

(1) The data presented demonstrate that Benemid in doses of 2 g per day per adult produced approximately 50% diminution in urinary 17-keto-steroids. This diminution was not exaggerated by increasing the dose of Benemid to 4 g per day. (2) Spectrophotometric studies showed that Benemid did not change the androsterone-dehydroisoandrosterone ratio of urinary 17-ketosteroids. (3) Urinary estrogens were diminished in one subject. In another subject this diminution was questionable. (4) Urinary 11-oxycorticosteroids (neutral reducing lipids) did not appear to be affected by Benemid.

(1) Maltose or takadiastase digested starch has been found to be one of the many growth stimulants for L. fermenti 36 in assay of thiamine. It is also stimulatory to L. arabinosus 17-5 and Strep, jaecalis R. in assays of pantothenic acid and pyridoxine. (2) Evidence has been obtained to prove that a precaution should be made on thiamine assay of starchy substances using L. fermenti 36 as test organism. Addition of enzyme digested starch or maltose to the assay medium is recommended.

(1) Attempts to demonstrate an agent in beta hemolytic streptococci which would accelerate the normal rate of capsular disintegration were unsuccessful. (2) Of various chemical agents tested, the following ions were ineffective in inhibiting this disintegration: Lead, cadmium, barium, manganese, lithium, silver, mercury, arsenite, iodide, bromide, periodate, cyanide and oxalate. (3) The following agents were found to retard decapsulation: Fluoride, azide, arsenate, citrate, and formaldehyde. The effect of fluoride was lost upon the addition of magnesium or calcium ions. (4) Fluoride did not inhibit the decapsulating action of streptococcal hyaluronidase. (5) The effect of temperature was found to be compatible with the assumption of a hypothetical enzyme system causing decapsulation.

Cobra venom, cardiotoxin, saponin and drugs of the digitalis series bring about the stoppage of the movements of the excised heart. The cardiac arrest caused by cobra venom, unlike that by saponin and digitalis, is irreversible, i.e., cannot be washed out. Unlike living muscle fibres, glycerinated muscle fibres and actomyosin threads show no contraction under the influence of cobra venom or cardiac drugs. These drugs have no effect on myosin and actin either.

Serum creatinine can be determined specifically on tungstate filtrates by using either the Miller-Dubos creatinine-splitting enzyme, or by adsorption on Lloyd's reagent and subsequent elution by alkaline picrate.

Cortisone was much more effective than 11-deoxycorticosterone in restoring the depleted arginase levels of the liver, mammary gland, kidney and intestine in the lactating rat adrenalectomized on the 4th day of lactation.

A survey of various tissues of the rat; and of beef and pork liver and kidney was made for the presence of the enzyme system that converts 3-hydroxyanthranilic acid to quinolinic acid. It was found that rat and pork liver homogenates quantitatively convert 3-hydroxyanthranilic acid to quinolinic acid. Beef liver also contains this enzyme system, but not all of the substrate metabolized could be accounted for as quinolinic acid. Rat, pork and beef kidney likewise contain the enzyme system but again not all of the 3-hydroxyanthranilic acid metabolized was found by the quinolinic acid assay. Spleen, muscle, brain, pancreas and testis of rats either do not contain the enzyme system or contain it in very small quantities. No evidence was obtained to indicate that the intermediate compound previously described had accumulated to account for the lower production of quinolinic acid by these preparations.

In 5 dogs subjected to evisceration and bilateral nephrectomy the rate of disappearance of sugar from the blood immediately after operation was nearly double the rate observed in 5 dogs similarly eviscerated but not nephrectomized, indicating that in hepatectomized dogs the kidneys may be an important source of sugar supplied to the blood stream.

(1) Fifty to 100 microcuries of radioactive iodine in the form of Nal were injected into the peritoneal cavity of the gestating hamster on the 8th to the 15th day after copulation. (2) Observations made on embryos of from 8 to 15 days of development by means of autoradiographic study and tests with the Geiger-Muller counter show that radioactive iodine begins to accumulate in the thyroid on the 13th day of development. (3) The accumulation of radioactive iodine is coincident with the appearance of discrete follicles, which first appear between the 12 th and 13th day of development. (4) The quantity of iodine-containing colloid increases with the number of follicles present and the age of the embryo.

Intracerebral inoculation of epidemic keratoconjunctivitis virus caused a fatal encephalitis in rabbits and guinea pigs, whereas inoculation of St. Louis encephalitis virus caused a non-fatal pyrexia in guinea pigs and elicited no response in rabbits. Mice were equally susceptible to both viruses while rats were refractory. Guinea pigs recovered from EK infection were also immune to SLE and those animals recovered from SLE were immune to EK. Rabbits convalescent from SLE were immune to EK, but the reverse experiment could not be done. Although EK immune mice resisted SLE, the reverse was not completely true.

Morphine sulfate, injected intramuscularly into ZBC male mice 30 minutes before exposure to total-body X-radiation, raises (the LD₅₀ of the radiation from 609 r to 830 r. Possible mechanisms of this effect are discussed.

Terramycin has been shown to be effective in reducing the mortality in rats when administered for a period of only 48 hours prior to 660 r of whole body x-radiation.

Antigens similar to those found in a strain of S. fecalis were found in all but one of the sulfathiazole, aureomycin, penicillin, and streptomycin-trained resistant strains of viridans streptococci. The antigens were not present in 5 of the parent strains with low sulfathiazole resistance but were present in 2 with higher resistance.

Effects induced by metabolized radioactive hydrogen (tritium or T) and presumed to be genetic in nature have been measured in Paramecium aurelia. Organisms were allowed to divide 6 to 8 times during 2 days in culture fluid containing T in concentrations varying from 1 to 100 mc per ml. With increasing radioactivity of the medium, increasing death after autogamy was observed, but no preautogamous effects were noted. The response observed after exposure to T appears to be slightly lower than that induced by emitters of more energetic /3 particles at similar dosage levels. The conclusions are that no part of the effect can be ascribed to transmutation of T, the emitted electrons alone apparently inducing the biological changes; and that the difference in efficiency between T and Sr89′90Y90 in inducing the effects observed is consistent with the observations of others concerning the dependence of the mutation constant upon rate of energy loss by densely ionizing particles.

(1) NDV from short-tailed shrews infected by intracerebral inoculation and intranasal instillation was 100% pathogenic for embryonated eggs in the first embryo passage. Shrews infected by these two methods of exposure showed typical Newcastle disease symptoms. The virus in the allantoic fluid of eggs inoculated with the shrew brain material from both intracerebral and intranasal series was neutralized by positive Newcastle disease serum but was not affected by normal chicken serum. (2) Electron micrographs of Newcastle disease virus preparations from chick embryos following infection by the virus propagated in the short-tailed shrew showed a predominance of tailed forms. (3) Intracerebral and intranasal serial passages of NDV in the short-tailed shrew are being continued at the present time and will be reported in a later paper.

(1) The development of resistance in a transplantable acute lymphocytic leukemia of the mouse to a guanine analog, 8-azaguanine, is reported. (2) Optimal growth of the resistant cells is attained in mice receiving near maximum tolerable doses of 8-azaguanine, indicating partial dependence of the variant line on the analog used in developing resistance. (3) The sensitive (control) line of leukemia has shown nearly complete inhibition of tumor growth at comparable transfer generations. (4) A-methopterin and TEM inhibit growth of the resistant line. (5) The biologic behavior of resistant leukemic cells, grown in mice receiving 8-aza-guanine, strikingly resembles sensitive cells grown in antagonist-free mice: A florid leukemia develops with leukocytosis and escape of lymphoblasts into the blood, severe infiltration into lymph nodes, spleen and liver, resulting in death at approximately the same time as controls.

The dorsal half of the amphibian gastrula was shown to have a significantly greater incorporation of methionine into protein than the ventral half.

The kidney of the rabbit was not found to excrete significant amounts of administered digitoxin. The dog appeared to excrete approximately 1-2% of an administered dose of digitoxin. The probability of the renal destruction of digitoxin in these species was discussed.

The treatment of mice with ACTH did not influence their susceptibility to PVM infection but slightly enhanced virus multiplication. Cortisone treatment enhanced both the virus infection and the multiplication of virus to a greater degree. Adrenalectomy rendered mice slightly less susceptible to infection and retarded virus growth.

The nutritional requirements of a strain of Polytomella agilis were investigated. Ethanol, butanol, acetate, propionate or butyrate were utilized as carbon sources. Glutamine was adequate as a sole source of nitrogen. Thiamine and vit. B₁₂ were stimulatory. A simplified medium, adequate for continuous subculture of this organism, is presented.

Adrenalectomy resulted in an increase in total count and increased absolute numbers of mononuclear and eosinophilic cells in the circulating blood of adrenalectomized mice. The increases were progressively greater with increases in the length of the interval after adrenalectomy from 4-5 days to 17-30 days. There was no consistent effect on neu-trophiles. Reticulocyte percentages increased in the circulating blood. The number of mitotic figures in the bone marrow was reduced, while the ratio of myeloid to erythroid elements was increased. All the differences noted were found to be significant. The results suggest a decreased rate of activity and of maturation of cells in the bone marrow and an increase in the length of period of maturation and longevity in the circulating blood.

The feeding to rats of diets containing as high as 0.1% of subtilin for 220 days was not detrimental as judged by growth, activity, organ weights and macroscopic and microscopic appearance of the tissues. The previously reported evidence for precipitation of parenterally-administered subtilin has been substantiated by microscopic examination.

(1) The hemagglutination technic of Middlebrook and Dubos has been applied to the study of streptococcal infections and rheumatic fever. Two of 4 streptococcal extracts gave excellent sensitization of sheep erythrocytes. These were the formamide extract, containing the group specific carbohydrate, and a concentrated solution of streptolysin O, which is a protein. Surprisingly, hemagglutination titers were identical with a variety of human sera when these two preparations were used as sensitizing antigens. (2) Hemagglutination was shown by many sera in titers ranging from 1:4 to 1:128, but there was no correlation between the magnitude of antistreptolysin and hemagglutination titers. Patients with non-strepto-coccal respiratory infections, streptococcal pharyngitis, and acute rheumatic fever could not be differentiated on the basis of the hemagglutination test. (3) The one consistent observation was that, for any one patient, hemagglutination titers tended to remain constant with both acute and convalescent sera. This suggests that a cross reaction of some type was responsible for the agglutination of red cells sensitized with streptococcal products. Further study is necessary to clarify the nature of this phenomenon.

In contrast with the expected extensive depletion of ascorbic acid, the biotin, folic acid, niacin and riboflavin content of the rat adrenal gland was observed not to be materially altered by exposure to cold.

1. Male rabbits were starved in order to study the effect of a decrease in food intake on potassium metabolism. 2. Serial determinations of the exchangeable potassium content and urinary potassium and creatinine excretion were made in one group of animals. The mean decrease in exchangeable potassiumcontent was 29.8 and 54.6% of the baseline value after one and two weeks respectively. The corresponding mean decrease was 15.6 and 31.7% in body weight. No significant changes in urinary creatinine excretion occurred. 3. In a separate group of rabbits, tissue analyses for radiopotassium and water concentration after one week of starvation revealed no significant changes when compared with control animals, continued on a constant diet. 4. The decrease in total body potassium content, as measured by the exchange of isotopic potassium, as well as the loss in the urine during starvation could be accounted for on the basis of tissue catabolism without postulating an intracellular deficiency of this cation in the remaining tissues. A functional abnormality in potassium metabolism may be detectable by the radioisotope method prior to its manifestation by the external balance method.

Experimental hypercholesteremia was produced by intravenous injection of sodium cholate into normal fasting rats. The implications of this finding were discussed.

1. The excretion and distribution of S³⁵-sucaryl in the tissues of the rat, dog, and rabbit were studied. 2. By means of cold isotope dilution and paperchromato-graphic methods, it was shown that in the rat at least 95% of the material was excreted unchanged. 3. Single doses up to 3.2 g/kg intra-peritoneally were rapidly excreted by the rat in 24 hours. A dose of 1.4 g/kg was excreted with equal rapidity by normal and a unilaterally nephrectomized rat. 4. With repeated oral dosing in rats about two-thirds of the drug was excreted in the feces and one-third in the urine. No significant amounts of S³⁵ sucaryl were found to be stored in the body. 5. In the dog only 0.5% of the injected S^35-sucaryl was found in the bile 5 hours after an intravenous injection of 9.7 mg/kg. 6. With the exception of the kidney and perhaps the liver, there was no significant concentration of the drug in the various organs of the rat, rabbit, and the dog. Sucaryl penetrated into the brain with difficulty, but was found in the fetus of the rat.

A study of the tributyrinase activity of the serum of normotensive, hypertensive, and arteriosclerotic male and female adults is presented. There was a decrease in the tributyrinase of the serum of hypertensive and arteriosclerotic males as compared with the normal, while the serum of the females shows no difference from the normal.

L-lyxoflavin stimulates growth of chicks under these conditions. Its mode of action remains obscure. Since it has no riboflavin activity, and its growth-promoting action occurs on a ration rich in riboflavin, it is quite possible that it acts as a true vitaminlike entity. The possibility that it acts in the same manner as the known antibiotics is unlikely, since the ration contained aureomycin.

Solutions of dextran, both in the unhydrolyzed or native form and in the partially hydrolyzed or clinical form, gave precipitation reactions with antiserums of rabbits immunized with S. typhi, including vaccines prepared for human typhoid prophylaxis. Reactions also occurred with antiserums of some other Salmonella, particularly S. oranienburg. Among 5 samples of clinical dextran that had previously been used in studies on humans, 4 that had given fairly frequent untoward reactions had greater capacities to fix complement with S. typhi antiserums than did the one that had given no untoward reactions.

In 6 experiments, minced fragments of normal adult human epithelium implanted subcutaneously in previously x-irradiated heterologous hosts (rats and hamsters) became vascularized, proliferated and increased for approximately 15 days. After this period they died suddenly. In un-irradiated control animals the epithelial material survived in poor condition for 3-7 days but did not become vascularized. When transferred every 10 days to new groups of x-irradiated animals, human epithelium remained viable and in active mitosis for the duration of the experiment (3 generations or 31 days).

The P³² labeled red blood cell method has proven satisfactory for the determination of blood volumes in swine. Values obtained ranged in regular fashion from 7.4 to 4.6 ml/100 g body weight for 10 to 344 lb animals^ respectively.

(1) Pressure-volume curves of the chest and lungs may be portrayed directly on the cathode ray oscilloscope to show the elastic and viscous properties described by previous authors (1,2). Alterations of muscle tone of the thorax affect the pressure-volume curve in such a way as to aid or resist artificial respiration and are immediately detectable by this method. (2) Pressure-flow curves may be recorded in a similar manner. This method permits the easy evaluation of the constants: involved in the equation P = KV + K'V² which are determined by the physical characteristics of the lung tree. (3) Inertia of the thorax causes a small lag between pressure around the chest and flow at the mouth. This time lag is of the order of one-sixtieth of a second.

Extraction of acetone-dried hog anterior pituitary glands with glacial acetic acid at 70 °C and removal of corticotropin with oxycellulose provides a method for the preparation of corticotropin and growth hormone in a single procedure.

Rats deficient in essential fatty acids exhibited a marked reduction in prostate and seminal vesicle weight. Administration of either methyl linoleate or chorionic gonadotropin restored these organs to normal weight.

(1) Aureomycin and terramycin are excreted in saliva when administered by mouth in capsule form. (2) The salivary glands do not concentrate the material excreted from plasma. (3) On an average, salivary excretion lasts for 24 hours after capsule medication has been discontinued. (4) A3 g dose reduces bacterial counts in saliva, and the inhibitory effect seems to last for 24 hours. (5) One 15 mg troche decreases bacterial counts significantly for at least one hour. (6) A second troche administered one hour after the first adds considerably to the antibacterial effect.

The storage of vit. B₁₂ in rat liver was investigated after feeding rats graded levels of crystalline vit. B₁₂ or of crude supplements. The vit. B_12M potency was determined with L. leichmannii after short-term auto-claving of the liver homogenates at pH 7.0. The vit. B₁₂ potency was shown to increase as the level fed was increased. The values were only 1/10 to 1/20 those for beef liver, however, and the vit. B₁₂ potency of rat liver was not reduced appreciably by alkali treatment. Studies on the desoxyribonucleic acid levels in rat livers and studies with Euglena gracilis assays for vit. B₁₂ indicated that the vit. B₁₂ activity remaining, as determined with L. leichmannii after alkali treatment, may be due to the presence of alkali stable forms of vit. B₁₂ as well as to desoxyribosides. The liver weight was shown to be greater per unit of body weight for the rats fed the vit. B₁₂-deficient diet as compared to the optimum diet.

A method is described for recording in vitro pressure responses from perfused segments of small blood vessels. The method permits accurate evaluation of the relationships between dose and response. For arterial biopsy specimens from the dog's mesentery, maximal pressure responses of 200 to 300 mm Hg are obtained with test doses of epinephrine at an intravascular concentration of about 1.0 γ/ml. The threshold for response is about 0.04 γ/ml. The latent period for chemical stimulation of these specimens is approximately 3 to 4 seconds.

Exposure of citrovorum factor (leucovorin) solutions to pH 2 for 24 hours at 25 °C resulted in inactivation of L. citrovorum activity but produced no alteration in the activity for S. faecalis. The acid-treated leucovorin was about one-tenth as active as leucovorin in reversing Aminopterin toxicity in mice. When administered to patients with pernicious anemia in relapse the acid-treated leucovorin was less active than leucovorin.

(1) A pulsatile perfusion system is described in which temperature, blood flow and mean pressure are controlled, and in which red blood cell solutions may be satisfactorily perfused through isolated limbs and organs. (2) In hind limbs perfused with blood of low colloidal content, 5.5 to 9.4 vol. % oxygen content were adequate in maintaining capillary function since a minimal rate of edema formation was observed which did not vary appreciably with flow. (3) Hind limbs perfused with 0.88 to 2.60 vol. % oxygen exhibited augmented edema formation which increased with increased flow. The critical hypoxemia level affecting capillary permeability is believed to lie between 2.6 and 5.5 vol. °/o oxygen content for the experimental conditions described.

The utilization of inorganic nitrogen in addition to organic nitrogen by the Toronto Strain of Park-Williams no. 8 Coryne-bacterium diphtheriae has been investigated. Ammonium nitrogen in the form of a simple ammonium salt (ammonium sulfate) is shown to be utilized by the organism. For optimum growth and toxin production on chemically defined medium, suitable concentrations of sodium glutamate and ammonium Sulfate, or ammonium glutamate are required.

The blood hydrolysate Sanguinin was tested in vivo in 268 albino mice accompanied by 221 untreated controls for its effectiveness against the beta-hemolytic Streptococcus zooepidemicus. Sanguinin solution (20 mg/ml) was inoculated subcutaneously (0.25 to 1.0 mg/mouse daily, usually for 4-6 days) either prior or after infection. Suppressive effect on the course of the infection was noted in all series of treated mice. A significant increase in survival time was noted in the pretreated series with an average survival percentage of 38.9 compared with 6.0 of the total of untreated controls. It does not appear that a direct correlation can be established between the survival rates and the intake of Sanguinin or the length of its administration, however, pretreatment seems to be of decisive value.

(1) A new chemical compound has been found which has high oral and parenteral parasympathetic blocking activity. This compound, N,N dimethyl 4-piperidyli-dene 1,1 diphenylmethane methyl sulfate (Prantal), is unique in its specificity of action within the parasympathetic system, i.e., it primarily inhibits gastric motility and gastric secretion. The intravenous sympathetic ganglion blocking dose is 50 to 100 times that required for intravenous parasympathetic blockade. (2) In dogs, roentgenologic observations of the movement of barium sulfate from the stomach indicate that orally administered Prantal delays gastric emptying time more effectively, and is longer acting than methantheline bromide. Additional dog experiments showed the ability of Prantal to reduce the volume and titratable total acid of gastric secretions. (3) After oral medication in dogs, Prantal produced no mydriasis at doses which inhibit gastric motility for several hours, whereas methantheline bromide caused mydriasis which persisted for one to 3 hours. In rabbit (tests by topical application to the eye, mydriasis occurred with a 0.1% concentration of methantheline bromide, whereas 1.0% of Prantal was not mydriatic; mydriasis occurred at the 2.0% concentration of Prantal. By intravenous injection in rabbits methantheline bromide caused mydriasis at 1.0 and 2.0 mg/kg doses; no mydriasis occurred at 2.0, 4.0 or 8.0 mg/kg doses of Prantal.

When man breathes ambient air at high altitudes an hypoxic stimulus causes a rapid increase in pulmonary ventilation. The full effect of this hypoxic stimulus is counteracted, however, by concomitant hypo-capnia. With the addition of carbon dioxide to inspired air a more effective response to the hypoxic stimulus is manifested. It is concluded that hypoxia and hypercapnia are separate stimulating factors and additive in their effects and that regulation of respiration at altitude depends upon the manner of their interaction.

The normal variation of rectal temperature in the hooded rat has been shown to be decreased during periods of electroconvulsive shocks. It is suggested that electroconvulsive shocks may affect the temperature regulation mechanism of the hypothalamus.

(1) The motility of Proteus vulgaris × 19 has been studied in a special chamber which permits prolonged and undisturbed observation of a group of bacteria under the influence of different chemical agents. (2) Strongest inhibition was observed with thiol inhibitors of the mercaptide-forming type, particularly with p-chloromer-curibenzoate. The oxidizing agent iodosoben-zoate and particularly the alkylating-SH drugs, iodoacetamide and iodoacetate, had aless marked inhibitory action. The specificity of the action of thiol inhibitors was confirmed in all cases by reversal of the inhibition with the thiol-reducing agents: glutathione and cysteine. Potassium cyanide, sodium azide, sodium fluoride and malonate had no action on the motility of Proteus vulgaris. (3) Substances having a narcotic effect, such as chloral hydrate, barbital, phenobarbital and chloroform, inhibited motility only at high concentrations. In these cases recovery of motility could be obtained by simply washing in buffer or saline. (4) Adenosintriphosphate had a definite stimulating effect on the motility of Proteus vulgaris. It was found that in bacteria inhibited with chloral hydrate vibration and translatory movements started within periods of time which were 110 and 74% shorter with ATP than with saline or other organic or inorganic phosphates. The possible role of -SH groups and of ATP in bacterial locomotion is discussed.

Kekwick has recently presented data on the size and shape of an A-substance preparation from pseudomucinous ovarian cyst fluid 1 . He obtained a molecular weight of 260000 and an axial ratio of 60/1 from ultracentrifuge and diffusion measurements. For comparison it seems worthwhile to present briefly data obtained on other preparations of A-substance 2 .

Materials. The closely related preparations R18-F10, R19-F1A, and R19-F2A of A-substance from hog gastric mucin were used ( 3 , 4 ).‡ This material is known to be chemically and immunologically inhomogeneous ( 3 , 4 ). The solvent used in all experiments was 0.02 M phosphate buffer at pH 7.1 with sufficient sodium chloride to give an ionic strength of 0.15.

Light scattering. Measurements were made at concentrations between 1.0 and 0.1%. Values of the reciprocal of specific turbidity were plotted against concentration and extrapolated to zero concentration. The molecular weights of R19-F1A and R19-F2A calculated from the values of (C/τ) c=o were 900,000 and 1,100,000 respectively. All samples were centrifuged for 30 minutes at 25,000 times gravity to remove optical haze. The refractive index increment for 5461 Å was 0.14 (concentration expressed as weight fraction).

Diffusion. Free diffusion measurements at 2 concentrations of R18-F10 were made at 1.3 °C in a Neurath cell using a Longsworth scanning optical system. By the height-area method

and by the method of successive analysis

for 5 determinations. Pycnometric measurements gave an apparent specific volume of 0.66 ml/g.

Viscosity. The values of specific viscosity, γ_tsp, divided by volume fraction of solute, θ, at different rates of shear are given in Table I. Measurements were made in an Ostwald-Fenske viscometer at 25°C.

Osmotic Pressure. Four measurements at one and 2% concentration gave the molecular weight of R18-F10 as 220,000 ± 30,000, uncorrected for deviations from ideal behavior.

Sprague-Dawley rats were exposed in a low pressure chamber 4 hours daily 0 to 30 days to a simulated altitude of 25,000 feet (bar. p. 282 mm Hg). During the following 12 days, they were given 8 intravenous injections of 5. mitis. Bacterial endocarditis was found in 87% of the rats acclimatized 30 days, but in only 44% if the exposures to altitude were discontinued after the first injection. It was found in 17% of rats never exposed to altitude, and in 45% of those beginning exposures to altitude immediately before their first injection. Endocarditis was found in 11 of 15 altitude rats given a single injection of S. jaecalis. The susceptibility to endocarditis in this study varied with the mean hematocrit value. Since the hematocrit value approaches a maximum in about 30 days, there seems to be little indication for increasing the preliminary exposures to altitude beyond 30 days. It is suggested that such altitude rats be used for screening of methods for the treatment of bacterial endocarditis in man.

1. Intact embryos of the grasshopper, Melanoplus differentialis, show similar rates of endogenous O₂ uptake when suspended in isotonic, Ringer or sucrose solution. 2. Homogenates of embryos suspended in Ringer solution show much higher O₂ uptake than those suspended in isotonic sucrose solution. 3. Isolated intact nuclei suspended in Ringer solution show much higher G2 uptake than those suspended in isotonic sucrose solution. 4. Isotonic sugar solution affects the endogenous O₂ uptake of only nuclei and no other parts of the embryonic cell. 5. Supernatants (cytoplasm minus nuclei) suspended in isotonic sucrose show greater stimulation of O₂ uptake by addition of succinate than when suspended in Ringer solution.

The skin of the squid functions as an organ of excretion. This is proven by feeding squids neutral red solution. The neutral red is eliminated by the skin in the form of dark red droplets, heavier than sea water and not soluble in it.

The effect of X radiation with 25,000 r can be kept latent in Melanoplus differentialis embryos for 6 months by maintaining them at submetabolic temperatures. In the resting grasshopper nucleus chromatin, in Belar's saline solution, is visible with the aid of phase contrast microscopy. When the eggs are irradiated and placed immediately at 0°C and kept at this temperature for 6 months no immediate morphological or physiological changes are observed upon returning them to 25°C. However, pyknosis occurs by 8 days at 25 °C depending on the irradiation and on the metabolic activity of the cell. Pyknosis in the living cell as observed by phase contrast microscopy resembles fixed material morphologically. Physiologically there is a difference in the physical state of the nuclei when observed in the living condition. Most nuclei show a drop in viscosity at the time of pyknosis as judged by the increase in Brownian movement. Vital staining with Janus green indicates that the mitochondria usually clump as a separate body whereas, the chromatin material becomes pyknotic containing lipoid impregnated bodies.

(1) A simple disc technic has been devised for determining concentrations of amethopterin in blood and urine. (2) This test has an accuracy which compares favorably with similar assay methods for antibiotics. (3) Amethopterin appeared in the blood and urine in detectable amounts 15 to 30 minutes after the ingestion of a 5 mg dose on a fasting stomach by 2 normal individuals, and 30 to 60 minutes after ingestion at the same dose by 4 normal non-fasting individuals. In some of the 6 it was still detectable at 6 hours, but in none after 24 hours. (4) Six normal adults excreted 40 to 57% of the ingested dose in the urine within 24 hours. (5) In one patient little difference in serum levels or total excretion could be demonstrated whether the drug was given by the oral or intramuscular route. (6) In a patient with impaired renal function, higher initial serum levels were obtained and detectable amounts were present in the blood serum 48 hours after ingestion of amethopterin.

The present study concerns itself with a titration of the encephalitogenic activity of mouse brain which induced acute disseminated encephalomyelitis in mice. In this regard the active agent revealed a potency higher than that hitherto described for the guinea pig receiving homologous tissue. The encephalitogenic factor was found not in the supernate but in the sediment after centrifugation at 8000 G; nor was it detected in a dialysate of mouse-brain tissue. Mouse brain was encephalitogenic in a heterologous species of animal and heterologous tissues were similarly encephalitogenic in the mouse; the disorder thus brought about by either was indistinguishable from that induced in mice by means of mouse brain.

(1) The injection of neoprene into the renal vessels in vivo causes vasoconstriction which interferes with the complete filling of the vascular system of the kidney. This vasoconstriction can be prevented by the production of ischemic vasodilatation prior to the use of the injection mass. Satisfactory neoprene casts of the renal vascular bed were obtained by the use of this technic, but the casts do not provide reliable information regarding the intrarenal distribution of the circulating blood. (2) The only consistently existing vessels which directly communicate between the renal artery and vein without an intervening glomerulus are situated in the hilum of the kidney. These vessels are not true arteriovenous shunts but probably are part of the vascular bed of the hilar and pelvic tissues of the kidney.

Testololactone has been demonstrated to have protein-anabolic activity, having passed both the levator ani screening test and a confirmatory nitrogen balance study. This compound showed a rapid effect, remarkably evanescent, which after quickly wearing off was followed by the rebound of nitrogen excretion in the urine to the basal level when testololactone treatment was continued. Testololactone is completely non-androgenic at the very high dose of 10 mg per day.

Myofilaments have been found in the smooth muscle of the gut of the turtleand chicken. They resemble closely the corresponding filaments of skeletal and cardiac muscle, revealing a repeating period of about 400 Å, and ranging in diameter from 150 Å to 230 Å. Internlamentary material is also observed in smooth muscle; but is fairly evenly distributed, and not disposed in repeating bands, as in striated muscle.

Pepsin-treated ACTH materials at approximately 10 times standard were fractionated in a chromatopile using the system butanol-acetic acid-water. The activity was found to be associated with a slow-moving ninhydrin-positive area from which fractions having potencies of about 50 times standard were recovered. No further chromatographic resolution of these fractions was obtained in the solvent systems ordinarily used for amino acids and peptides. In all cases, the activity was associated with ninhydrin-positive areas of the chromatograms.

(1) The weight of the adrenal glands of guinea pigs on graded levels of intake of ascorbic acid varied inversely with daily intake of this vitamin. (2) A progressive decrease in the number of circulating eosinophiles occurred in guinea pigs maintained on a scorbutigenie diet. (3) There was a delay in onset of severe symptoms of scurvy and an increase of the mean survival period in scorbutic animals treated with ACTH. (4) The administration of a large close of ACTH to guinea pigs with severe scurvy was promptly followed by a decline of more than 50% in the level of circulating eosinophiles. (5) These observations are interpreted as indicating that ascorbic acid deficiency functions as a non-specific stress and that this vitamin is not directly involved in mechanisms of elaboration of adrenal cortical hormones with an oxygen atom at the C-ll position.

1. Normal strains of types b and d H. influenzae have been directly transformed to new types of H. influenzae; type b was changed to types a, c and d, and type d into types a, b and c. 2. The rate of occurrence in type d populations of cells susceptible of transformation has been shown to be not significantly different from that found earlier in R cell populations derived from type d. Comparisons in the presence of more potent anti d antibody have been made subsequently between populations of Rd and type d for frequency of cells susceptible (initially or during growth for 24 hours) to transformation to type c. No real differences could be demonstrated when this more efficient selective agent was used.

(1) In all 16 patients in this study there was a lowering of the erythrocyte count, hemoglobin and hematocrit during the 4 to 10 days that estrogen was administered.

On cessation of estrogen therapy there was a subsequent return to the initial blood constituent levels within a period of 5 to 8 days. (2) Evans Blue dye studies made in 3 of the 16 women demonstrated that the blood volume increased sufficiently to account for the lowering of the red cell count, hemoglobin and hematocrit. (3) During short periods of estrogen therapy there may be a significant hemodilution. Further studies are necessary to determine whether this effect is transitory or whether it may be maintained indefinitely.

Studies by electron microscope of brains and spinal cords of mice infected with West Nile virus, B 956 strain, show the virus to be cube-shaped with a diameter of 38-40 m/x. These bodies could not be demonstrated in concentrated normal mice brains and spinal cords subjected to the same procedure of concentration and examination. The bodies from the West Nile preparations resemble the rabbit papilloma virus described by Sharp et al. 3 The virus in the concentrated material was infectious for unvaccinated mice but had no effect on mice previously immunized against the West Nile virus.

These studies substantiate previous reports that a relatively large proportion of injected labeled protein is found in the mitochondrial fraction of homogenized liver(8). Failure to demonstrate in this fraction the azoprotein which was added to the whole liver homogenate indicates that an in vivo process is involved and that simple adsorption of the azoprotein by mitochondria does not occur. Results of microscopic study of wafers, made by centrifuging mitochondrial fractions, indicate that the intracytoplasmic granules of azoprotein seen in sections from injected animals(1-3,5) are found predominantly in such mitochondrial fractions. However, the facts that injected India ink particles occur in a similar proportion in such fractions, that the azoprotein granules do not take various mitochondrial stains, and that other impurities can be demonstrated in such preparations, indicate that such mitochondrial fractions do not consist only of mitochondria. This conclusion has also been expressed by previous workers, and such fractions have been subfractionated(16). The differences in re-suits with the various mitochondrial stains not only emphasize the inhomogeneity of these preparations, but indicate that such stains do not provide adequate characterization of mitochondria. It is apparent that much more work must be done on the composition of mitochondrial fractions prepared in this way, and on the significance of the results of mitochondrial stains, before cytological and biochemical data on such preparations can be equated with assurance. Since intraeytoplasmic azo-protein granules apparently differ in some respects, both physically and histochemically, from other granules in these preparations which fulfill more of the criteria for mitochondria, the occurrence of labeled proteins in mitochondrial fractions does not as yet seem to justify the conclusion that these proteins are attached to mitochondria, or that mitochondria are the site of antibody formation.

The results of colorimetric and microscopic studies on cell fractions prepared after intravenous administration of variousapoproteins to mice are presented. The azoprotein granules seen intracellularly in the tissues of such animals are present predominantly in the mitochondrial fraction. Evidence that such granules are not labeled mitochondria is presented, and the significance of the variation an the results of different staining technics on mitochondrial fractions is discussed with regard to the homogeneity of these preparations.

(1) A detailed procedure for preparing a “phosphorus-free” protein hydro-lysate capable of supporting excellent growth of group A hemolytic streptococci in combination with other chemically defined constituents has been described. (2) This medium has been used successfully for tagging group A hemolytic streptococci with radiophosphorus.

Intravenous administration of 0.075 unit of crystalline insulin per k body weight to normal individuals evoked the expected changes in the blood sugar level and was accompanied by a significant lymphocytosis. Intravenous injection of the same amount of insulin followed 30 minutes later by oral administration of 0.8 g of glucose per k body weight produced an initial decline of the blood sugar level followed by a rise above the fasting level of from 26 to 79 mg %. This was accompanied by a rise of the absolute lymphocyte count to a maximum at 30 or 45 minutes and a secondary decline to a minimum at 150 minutes. The magnitude of the difference in the lymphocyte responses to the Insulin Tolerance Test and to the Insulin Glucose Tolerance Test approaches that of the decline of the absolute lymphocyte count observed when glucose is administered alone. The change of the absolute lymphocyte count therefore does not support the thesis that glucose after insulin magnifies the homeostatic response to hypoglycemia but suggests rather that there is a summation of effects.

Exogenous cholesterol after its intestinal absorption was found to be conveyed into the systemic circulation by the lymph of the thoracic duct. Little or no transport occurred via the portal venous system.

Primaquine showed a strong suppressive action during the early stages of experimental T. cruzi infection in mice. Most treated animals survived infection with a virulent strain and all showed a disappearance or marked decrease in the number of parasites present in the blood. The activity of the drug seems to be stronger than other drugs so far known to be effective against T. cruzi infections.

Rats show a substantial loss of potassium from a majority of radiosensitive tissues beginning within 24 to 48 hours after irradiation. There is a comparable loss of radiopotassium from bone. Radiopotassium excretion is increased in the urine of irradiated rats, and there is a rise in fecal levels with the onset of diarrhea. It is evident that rats that have been irradiated at over an LD50 level develop an absolute potassium deficiency.

Radiosensitive tissues show a variety of alterations in radiosodium concentration after total body irradiation above an LD50. In several tissues there is a decrease followed by a sharp increase; the decrease occurs at the same time as a decrease in radiopotassium concentration. An increase in percentage water content may occur when there is a fall in radiosodium concentration. Percent loss of dry weight per day is in general most pronounced in radiosensitive tissues. Urinary excretion of radiosodium after total body irradiation at levels approximating an LD50 shows a complementary homeostatic decrease in response to the excessive loss of radiosodium through the gastrointestinal tract.

(1) The solubility of bovine fibrinogen in ethanol-water mixtures has been studied. The behavior was qualitatively similar to that of the human protein, but the influence of pH was much smaller. (2) A procedure for refractionating bovine Fraction I to give a 90% clottable product is described.

(1) Hyperimmune, WEE antiserum, prepared in rabbits by a series of 5 fairly closely spaced inoculations, yielded a 50% serum dilution titer of 1:1,800 against 40 LD₅₀ of virus in the routine intracerebral neutralization test. When the intra-abdominal neutralization test was used, the amount of virus neutralized by various dilutions of the serum was always greater, but the limiting effective dilution of the serum was about the same as in the intracerebral assay against 40 LD₅₀ of virus. (2) After intravenous injection of this antiserum in mice, the mouse serum acquired a neutralizing activity which indicated that the antibody underwent a dilution roughly in proportion to the size of the animal. (3) Prophylactic effectiveness was tested by injecting intravenously various dilutions of antiserum into 2-week-old mice, and 4 hours later inoculating these mice intra-abdominally with varying dilutions of the virus. Passive transfer of just enough antibody to impart to the undiluted serum an intracerebral neutralization index of approximately 50, protected against 400-4,000 intraabdominal encephalitogenic doses of virus; the actual amount of virus contained in this dose was 2 million (mouse) intracerebral LD_50. The amount of antibody required for passive protection varied with the size of the infecting dose, so that 0.02 ml, 0.2 ml and 2 ml of the antiserum per kilo of body weight yielded protective indexes of 400, 16,000 and 100,000 respectively. The significance of these data for the problem of the prophylactic use in human beings of concentrated antisera against the arthropod-borne encephalitis viruses is discussed.

Two strains of bovine encephalitis virus have been adapted to mice, cotton rats, and rhesus monkeys causing meningo-encephalomyelitis. Evidence was presented to show that the Lansing strain of poliomyelitis virus and the bovine encephalitis virus are related serologically.

A method is described for the quantitative extraction and purification of small amounts of lipid with a minimum of manipulation. The acid-soluble material is removed from the tissue with cold 10% trichloracetic acid containing 0.4 M MgCl_2. The lipid is removed from the residue using ethanol-ether. This extract is taken to near-dryness, re-extracted with petroleum ether-chloroform, and the latter solution washed with water and dried. The lipid thus prepared has been found to compare favorably in several respects with lipid purified according to McKibbin and Taylor(3).