Experimental Biology and Medicine

The effect of 9 environmental temperatures between 10° and 40° on survival time and on body temperature of rats in traumatic shock was studied. The results indicate: 1. that the optimum temperature is 20°. Survival time at this temperature is significantly better than at 17.5° or 25°; lower or higher temperatures are increasingly harmful. 2. Animals in shock appear to be poikilothermic, their body temperatures tending to approach the environmental temperature.

Viruses that produce similar cytopathic changes in vitro characterized by presence of intranuclear inclusions have been isolated from 3 infants during life. The first derived from a liver biopsy from a 3-months-old child (Davis) with microcephaly, persistent jaundice, and hepatosplenomegaly; cytomegalic cells were demonstrated in the liver specimen. From a second child, virus was isolated from a liver biopsy, and on three occasions between the 14th and 91st day of life from the urine. This infant had jaundice and hepatosplenomegaly. More recently, an agent was recovered from the urine of a third infant, who evidenced hepatosplenomegaly, cerebral calcification and chorioretinitis. The Davis strain has been propagated in human fibroblasts for 20 passages during an elapsed period of 494 days. Neutralization tests with the Davis agent have indicated that neutralizing antibodies occur frequently in children with cytomegalic disease but also are not uncommon in normal adults. The agents are apparently related to those recovered in other laboratories from a human salivary gland, from a fatal case of cytomegalic disease, and from spontaneously degenerating tissue cultures of human pharyngeal tonsillar tissue.

Two amides, l-glutamine and l-asparagine, were tested for anti-convulsant activity in mice after acute administration by a battery of 6 anticonvulsant assay procedures and after chronic administration by 3 tests. In addition, both agents were tested in mice for ability to prevent methionine sulfoximine-induced seizures and in rats for ability to elevate the minimal electroshock seizure threshold lowered by food restriction. The results indicate that both these agents are virtually devoid of anticonvulsant activity as measured by a number of diverse laboratory screening procedures.

1. The average time to equilibrium following intravenous injection of D₂O in 16 normal adult mongrel dogs was 129.4 minutes. Equilibrium was established in thermally injured dog in 148.1 minutes. There were no statistically significant differences between animals before and after thermal injury. 2. Equilibrium should not be assumed to be complete at 2 hours in either normal or pathologic states. Consecutive blood samples should be taken over a longer period of time, preferably up to 5 hours. A point of equilibrium should be selected when variation is within 5% of final volume of distribution at 5 hours. 3. Because of wide variation in time to equilibrium in both normal and pathologic states, any conclusions regarding changes in “efficiency of total circulation” should be studied carefully and interpreted cautiously.

In failing cardiac muscle, postextrasystolic potentiation decreases at a slower rate than response in a series at a regular frequency. Postextrasystolic contraction is not improved by ouabain. The latent period of ouabain action is related to elapsed time, not the total number of contractions.

Stable cell suspensions were prepared from Limulus blood using 0.05-0.10% formaldehyde. Washed cells could be agglutinated by as little as 0.01 volume of fresh homologous plasma. The initial stages of this reaction showed moderate concentration dependence and very strong temperature dependence.

Among 28 subjects with and without hypertension, the group with high blood pressure had significantly greater (p<.01) sodium intakes (as measured by urinary outputs) than did the group of non-hypertensives. This finding was in agreement with a hypothesis previously proposed, namely, that the level of sodium intake was of primary etiologic importance in the development of essential hypertension.

1. The observation that AZS affects the rat fetus in utero is confirmed and greatly extended. 2. AZS acts on the fetus directly—and not on the ovary, placenta or pituitary. 3. AZS efficiently destroys the entire litter of rats in doses of: (a) 5 mg/kg at the time following implantation (7th and 8th days of gestation); (b) 10 mg/kg at midterm (11th and 12th days of gestation); without affecting the mothers adversely. 4. This drug effect is sharply limited in time. 5. Combination of 6MP and AZS was effective in litter destruction in smaller doses than either compound alone. 6. Neither progesterone nor adenine protected the litter against AZS. 7. AZS given before mating did not delay it, nor did it affect the subsequent litter. 8. Rats aborted 4 and 5 consecutive times with AZS showed no accumulative toxicity nor impairment of their fertility. 9. Litters raised from rats aborted 4 or 5 times were normal in all respects and produced normal litters.

DON affects adversely the fetus when given from time of implantation to mid-term, and two doses of .5 mg/kg during this time will result in complete litter destruction. The action of DON appears to be directly on the fetus and not on placenta, ovary or pituitary. Progesterone given prior to DON administration did not protect the litters. Large doses of adenine sulfate given prior to DON administration protected the litters to a large degree. Repeated complete litter destruction in the same animals gave no evidence of cumulative toxicity, nor did DON adversely affect the fertility of the mother rats, or subsequent offspring.

1. The effect of TR, TEM and TEPA on rat fetus and litter in utero was studied with 2 doses of the 5 LD₅₀ on 4th and 5th, or 7th and 8th, or 11th and 12th days of gestation. 2. TR had no effect on the rat litter and can be regarded as a control series to TEM. 3. TEM had its maximum effect at the time of implantation, but failed to destroy the entire litters. An increase in dosage from .3 mg/kg to .5 mg/kg given at the time of implantation led to 100% litter destruction. 4. Progesterone administration protected 40% of the fetuses against otherwise lethal doses of TEM. 5. Rats treated with TEM displayed uniformly smaller placentas than normal. 6. TEM in combination with AZS given on the 15th and 16th days of gestation led to much stunting of the fetuses, to 32% of fetal death, but in no instance to complete litter destruction. 7. Freshly prepared TEPA destroyed all litters when given on the 7th and 8th, or 11th and 12th days of gestation. 8. The malformations observed with TEM and TEPA consisted of cranial defects and abnormalities of facial structures. 9. TEM and TEPA in doses used affected adversely the bone marrow and lymphoid system of the mother animals.

1. 2-6-DP, CIP and ThG were given to groups of pregnant rats in 2 doses of 5 LD₅₀, not toxic to the mother animals. The compounds were given on the 4th and 5th, or on the 7th and 8th, or on the 11th and 12th days of gestation. 2. 2-6-DP showed a peak of action on the fetuses and litters when given before implantation, destroying 75% of all the fetuses, but only 57% of all the litters. 3. CIP showed a peak of action on the 7th and 8 th days, destroying all fetuses and litters. Treatment on days 4 and 5 of gestation destroyed 69% of the fetuses, but only 32% of all litters. At midterm, no litter was completely destroyed, and only 10% of all the fetuses were resorbed. However 50% of all survivors were stunted and malformed. 4. ThG was the most toxic compound to the fetuses. At the time of implantation it destroyed all fetuses. On days 4 and 5 of gestation, it led to resorption of 75% of the fetuses, but only to 10% complete litter destruction. At midterm it still destroyed 61% of all fetuses, and 43% of all litters, while stunting 37% of all survivors. 5. The lethal action of CIP and ThG on the rat litter at implantation time could not be prevented by progesterone administration.

1. In a deficiency of vit. B₁₂ and folic acid in rats, there is a significant reduction in total serum proteins and in serum albumin, α₁-globulin and γ-globulin. An increase in the proportion of β-globulin is probably indicative of higher serum level of free vit. B₁₂ in the deficient state. 2. Dietary protein level influences serum concentrations of albumin, α₁-globulin and, to a lesser extent, γ-globulin.

This investigation gives experimental evidence that at autoclaving temperature (121°C) a type of browning occurs which involves reaction of dextrose with lecithins as well as with amino-groups of cephalins. Therefore, use of pure lecithin as an emulsifier in an oil emulsion containing dextrose in the water phase would not eliminate formation of the brown material. The complex browning reaction is responsible for formation of a colloidal material found in phosphatide-containing fat emulsions prepared for intravenous alimentation, and might be a possible explanation of certain adverse physiological results occasionally experienced with the use of these emulsions.

Synovial tissue has been shown to be capable of in vitro production of a mucopolysaccharide believed to be hyaluronic acid. Cultures from donors ranging from a fetus to an elderly male shared this capacity for periods of 6 weeks to 6 months. This process is supported by a nutrient medium that is 80% defined and excludes embryo extract. Culture behavior and cellular morphology are described.

It has been shown that glucagon has a marked enhancing effect on renal excretion of I¹³¹, Na⁺, K⁺, Cl^- and PO₄—in both the anesthetized and conscious dog. This action of glucagon, which is independent of its hyperglycemic effect, appears to be due to a direct action on the kidney tubules. The physiologic significance of these effects remains to be clarified.

Studies are presented on the influence of temperature and of a number of chemical substances upon coagulation of proteins of the seminal vesicle secretion by the prostatic enzyme vesiculase. Experiments involving delayed addition of metal chelating agents and of heavy metal ions have shown that the coagulation process can be separated into two distinct stages.

An in vitro culturing technic was used in comparing metabolism of calcium-45 and strontium-89 in bone. The results of a large number of determinations indicated: a) that at 2 hrs bone contained 1.08 times as much strontium-89 as calcium-45; b) when exposed to constant levels of Sr⁸⁹ and Ca⁴⁵, the Observed Ratio_bone-medium equilibrated at 0.83 within 7 days; c) strontium-89 was released from bone at a ratio of about 1.2 times that of calcium-45; d) addition of carrier strontium markedly inhibited the long term deposition of calcium in bone but the discriminatory mechanisms were unaltered.

(1) Beta aminopropionitrile hydrochloride was toxic to turkey poults at levels as low as 0.01% of diet. (2) Paralysis. degeneration of anterior motor neurons and growth depression were the chief abnormalities observed at 0.25% and 0.125% while pericardial and pulmonary hemorrhage, ruptured aortas, leg and toe deformities, and growth depression were the primary symptoms at lower levels. (3) Preliminary attempts to alter severity of symptoms by reducing the methionine level or by adding vit. B₁₂ or a high level of all B vitamins were not very successful, but further investigation of the B vitamins appears to be justified.

Lipid partition and phospholipid metabolism of the aortic arch and descending limb of aorta, plasma and liver were determined in groups of rabbits on a normal diet and 40 and 70 days on a cholesterol-supplemented diet. In all groups, the descending limb of aorta had significantly lower total lipid, primarily due to decreased neutral fat concentration, compared with the aortic arch. In normal rabbits the specific activity of phospholipid in the descending aorta was significantly greater than that of the aortic arch. However, this distinction in phospholipid synthesis between the two areas of aorta was not found in the groups of rabbits on the high-cholesterol diet. The radioactivity data indicated this was due to an increased rate of formation of phospholipid in the aortic arch of rabbits fed the cholesterol-supplemented diet, particularly those rabbits on the diet for 70 days, and probably was related to the development of atheromatous lesions in the arch only of these rabbits. The results were discussed in relation to the general problem of local factors in the arterial wall influencing the localization and subsequent development of atherosclerotic lesions.

Sublethal quantities of homologous and heterologous influenza virus, mumps virus, and Newcastle disease virus injected intravenously in mice produced a state of resistance to the toxic effects of large quantities of intravenously injected PR-8 influenza A virus. Virus heated sufficiently to destroy infectivity was less effective in inducing resistance than was fully active virus; destruction of hemagglutinin caused complete loss of resistance inducing activity. Injection of sublethal doses of virus was followed by a lag period, which varied with the virus injected, before resistance became demonstrable, and resistance waned after 3-4 days. No increase in resistance to influenza toxicity was demonstrable after pre-challenge injection of feline pneumonitis virus, R. prowazeki, or typhoid vaccine. A preparation of receptor destroying enzyme (RDE) was effective in inducing increased resistance but its effect could not be attributed to its capacity for destruction of mucoprotein receptors since heat destruction of this activity did not completely destroy its resistance inducing effect.

The results of typical experiments in host-parasite relationships at cellular level, using Brucella abortus-mononuclear phagocyte systems, have been presented. The intracellular multiplication of Br. abortus in normal guinea pig mononuclear phagocytes was observed. In Brucella abortus-immune mononuclear phagocyte systems the multiplication of the organisms was significantly restricted.

Experiments were carried out 4 to 6 days after inoculation of approximately 2 × 10⁷ Ehrlich ascites tumor cells in mice. When the 2-hour incorporation of P³² into DNA was measured at various times after irradiation (800 r total body x-irradiation), no significant depression in DNA specific activity was observed until 1 day. Measurements of mean cell volume, mean DNA content per cell, and mean total nucleic acid content per cell at 13 and 20 hours revealed that all 3 quantities increased at approximately the same rate, closely matching the growth rate of the unirradiated tumor and rate of DNA formation estimated from the incorporation data. The increased DNA content per nucleus after radiation was confirmed by Feulgen microspectrophotometry. At 48 hours after irradiation cell volume and total nucleic acid per cell had risen even higher while DNA per cell showed little further increase. The data suggest that the irradiated cells continue to synthesize DNA until they reach the premitotic DNA content (octoploid in Ehrlich cells) and are arrested there because they are unable to go through mitosis.

Pregnant mice kept for 2 hours during the 10th day of gestation in a gas chamber containing 6% oxygen in nitrogen at normal atmospheric pressure produced progeny having malformed ribs and vertebrae.

1) In the forearm the maximum transcapillary loss of S³⁵-labeled 1-methionine averaged 47.6 ± 7.3%. Methionine exhibited a pattern of transcapillary net exchange which is consistent with intracellular binding. A high rate of net loss was observed for a much longer period than with thiocyanate ion and the equilibrium time was delayed considerably. Net return to the circulation was small compared to thiocyanate during the period of observation. 2) On the basis of these and other observations it is suggested that 3 distinct classes of substances have characteristic patterns of trans-capillary net exchange which may be distinguished with the present technic. These substances are (a) primarily extracellular ions, (b) primarily intracellular diffusible substances, and (c) highly diffusible molecules which are distributed throughout both compartments (body water).

Solutions of estrogenic steroids were administered intravenously to dogs. There was a sharp rise in the plasma Acglobulin and prothrombin concentration. These changes began within the first 15 minutes, reached a peak in about 1 and 1/2 hours. In about 3 or 4 hours normal concentrations were again found. A small decrease in antithrombin activity of plasma was found. Theoretically all these changes tend to enhance coagulability of the blood.

The acute toxicity of isoniazid (INH) in DBA mice by gavage, LD₅₀ = 5 mg/20 g mouse, may be reduced by simultaneous administration of the antibiotic cycloserine (CS). Each of 22 mice survived a single dose of 8 mg INH with 75 mg CS (0.4 g and 3.75 g/kg respectively), or of 10 mg INH with 100 mg CS (0.5 g and 5.0 g/kg respectively). On repeated semi-weekly administration for 10 weeks, 19 of 26 mice, 73%, survived the latter mixture. Significant amounts of INH were detected in the blood plasma 72 hours after the 20th dose. In in vitro bacteriostatic tests with 4 strains of Mycobacterium tuberculosis, CS did not interfere with the activity of the INH.

Since submission of this manuscript for publication, a statement in a technical bulletin indicated that in clinical use “toxicity (of CS) is decreased and its efficacy increased” when administered with INH. (Phys. Bull., 1956, v21, 227).

1. Using the method of Wroblewski and LaDue the LDH activity in serum has been localized to 3 electrophoretic regions. In 6 control subjects approximately 48% of the LDH activity in serum was present in the α₂-globulin, 33% between the α₁-globulin and albumin and 19% in the β-globulin. 2. Three peaks corresponding approximately to those found in serum were observed in the hemolysate from human red cells. In the 2 cases of myocardial infarction in which the total LDH activity was increased the α₁ activity peak was differentially raised while in 3 cases of leukemia, although the total activity was increased in only one instance, the percentage of the total LDH activity in the α₂ peak was uniformly increased. 3. The results obtained suggest that an examination of the LDH activity in the different serum fractions may provide a more sensitive index of alterations of LDH activity than examination of the total serum concentration of the enzyme. 4. The distinguishing chemical and physical properties of the enzymes in the three peaks, in addition to the observed electrophoretic difference, remain to be studied.

1. Rats fed on diet containing butter fat required a higher level of choline to reduce the level of liver fat to within the normal range, than did rats fed the same level of corn oil. This “requirement” for choline, as measured by liver fat, was not greater than 0.12% of choline chloride with diet containing 30% of corn oil and about 0.15% of choline chloride with diet containing 30% of butter fat. These values were not affected by supplements of cystine, or methionine and tryptophan or all 3 amino acids. 2. When no choline was fed, rats receiving butter fat grew at a more rapid rate than those receiving corn oil. It is suggested that the reduced rate of growth of rats fed corn oil was caused by kidney damage.

A method is described by which .04-0.4 ml of blood may be cross-transfused in 9-18-day-old chick embryos with almost no increase in mortality over untreated control eggs. Of the 567 eggs tested, 82% hatched, as compared to 87% of the control eggs.

1. Following intraperitoneal injection, fructose formed liver glycogen more rapidly, and to a greater extent, than glucose in depancreatized rats. 2. When injected intraperitoneally, glucose formed liver glycogen as rapidly in depancreatized rats as in normal rats. 3. Absence of the pancreas from the otherwise intact rat showed no apparent effect upon activity of any of the enzymes involved in formation of glycogen from fructose or glucose in the liver. 4. The data obtained suggest that the metabolic processes in the liver involved in formation of glycogen from fructose or glucose are not directly influenced by insulin.

Pregnant rats were treated with single doses of x-ray irradiation. The heart and great vessels in thorax of offspring were investigated when the rats had reached at least 10 days of age. The method of dissection is described. In 46 young rats that survived 10 days no cardiac abnormalities were found. Examination of young rats that died before 10 days was not carried out.

The gas pocket method of estimating O₂ tension of subcutaneous tissue was utilized to see if the protection afforded by CoCl₂ and adrenalectomy in high oxygen pressure could be due to a generalized depression of tissue pO₂. (a) Mice previously treated with cobalt and control animals previously treated with saline were studied in O₂ at one atmosphere and in room air. (b) Pockets were observed in an experimental group during a period of cobalt injections and in control animals which received saline injections. (c) Gas pockets in a group of adrenalectomized mice were compared with those in intact, untreated controls. The cobalt injections produced an increase in pO₂ of the gas pocket which appeared the first day after beginning treatment. The adrenalectomized mice showed no difference from their controls in gas pocket pO₂. Since decreased pO₂ was not observed, it was concluded that the protection of the two treatments against oxygen toxicity must be due to other factors.

Hypophysectomy, with or without adrenalectomy, abolishes the anticortisol effects (upon catabolism inflammation, thymolysis and splenolysis) of desoxycorticosterone acetate, seen in the adrenalectomized rat. Apparently, the anticortisol actions of mineralocorticoids are indirect, and depend upon some hypophyseal conditioning factor.

Measurements of sodium, potassium, pH, total solids and pigment in human gallbladder bile indicate wide variations. Potassium is present in higher concentrations than in extracellular fluids. The resorptive power as measured by pigment failed to correlate with the increase in potassium concentration and total solids.

Pregnant female rats were fed diets containing different amounts of chlortetracycline. When the prenatal diet contained 2 g/kg the antibiotic was present in the fetal tissues. At levels of 0.5 and 2.0 g/kg of diet, detectable amounts of the antibiotic were present in the mammary glands of the females and in tissues of the suckled young. The higher level of antibiotic (2 g/kg) improved the conception rate but did not affect the size of the fetuses or the number of young per litter.

1. The uptake of sulphone by leprosy patients was investigated, employing S-35 tagged diamino - diphenyl - sulphone (DDS). After oral administration: (i) total amount of drug in blood increased rapidly during initial hours reaching a maximum of about 8% of dose at 6 hours and then gradually decreased at an average rate of 62% per day to a negligible level in about 5 days; (ii) on an average 78% of the drug was excreted through the kidneys within about a week; the average rate of excretion being 42% per day; (iii) level of drug in bone-marrow and healthy skin was almost parallel to that in blood; (iv) the drug was preferentially localized in diseased skin tissues, where concentration was about 10 times greater than that in healthy tissues. 2. Subcutaneous injection also revealed similar preferential localization in affected regions. The significance of these findings is discussed.

A method is described which employs a combination of paper chromatographic and radioactive isotope technics. It is applicable to a wide number of hydroxylated steroids and is specific and sensitive to less than 0.1 μg quantities of steroids. The sensitivity is dependent upon the number of hydroxyl groups and specific activity of the radioactive acetic anhydride which is used to label the steroid. It has been applied successfully to the analysis of steroids in blood, urine, and a variety of tissues.

1. X-irradiation caused a release of potassium from the isolated rabbit heart, the rate of release reaching a peak after a dose of about 2,500 r delivered at 500 r/minute. The greatest average increase of potassium in the perfusate was 12% over the control level. 2. Potassium is liberated from the isolated rabbit heart in small amounts following exposure to as little as 500 r of X-ray. 3. Isolated rabbit hearts exposed to 1000 r released into their perfusate more than 4 times as much potassium in 1 hr as did non-irradiated hearts. 4. The X-irradiated in situ dog heart also released potassium into the coronary circulation. The magnitude of the effect and the radiation dose producing it were approximately the same as in the isolated rabbit heart.

Experiments in rats indicate that somatotrophic hormone (STH) can greatly aggravate skeletal manifestations of experimental lathyrism that are produced with aminoacetonitrile (AAN). This is so even under conditions whereby STH fails to stimulate growth in length.

1. An improved microbiological procedure, specific for the L- form of glutamic acid, was developed and shown to yield reproducible and accurate values for this amino acid in protein hydrolysates. 2. A sample treatment resulting in complete racemization of glutamic acid was developed to permit estimation of total (L- plus D-) glutamic acids from the L-glutamic acid content of treated materials. 3. L-Glutamic acid and total glutamic acids were determined in casein, 3 lactic acid bacteria, and 4 mycobacteria. D-Glutamic acid was negligible in casein hydrolysate but appeared to constitute 10% to 15% of the total glutamic acid in hydrolysates of mycobacteria and 20% to 44% in hydrolysates of lactic acid bacteria.

1. The excretion of phenylpyruvic acid by patients with phenylketonuria is roughly proportional to their fasting serum phenylalanine levels. Phenylpyruvic acid is not detectable in urine of patients with serum levels below 15 mg% phenylalanine. 2. Children less than 3 years old frequently show much higher serum levels of phenylalanine than older patients. 3. The incidence of known phenylketonuria in Utah during the past 10 years has been 1 in 20,400 births.

A procedure for direct complement fixation with unheated turkey and chicken serum or citrated plasma is outlined. Three viral systems, ornithosis, Newcastle disease and infectious bronchitis have been tested. Results are compared with other serological methods.

Gastric retention of a lipid may lead to erroneous conclusions when rates of fat absorption are measured by the generally accepted methods. Separate recoveries of the remaining lipids from the stomach and intestines after an absorptive period permits a correction for the lipid unavailable for absorption in relative rate calculations.

Most of the radiosulfate in S³⁵-labeled rat blood platelets was recovered in an alkali extract. The extracted material stained with Alcian blue for mucopolysaccharides and was found to behave similarly to chondroitin sulfate when subjected to paper electrophoresis and paper chromatography.

2-methyl-9a-fluorohydrocortisone will revive adrenalectomized dogs from severe insufficiency and restore them to normal health within 48-60 hours even though they are deprived of food and water during recovery. The steroid fully corrects the distorted fluid and electrolyte equilibria of the blood. The lowered arterial pressure, serum Na and Cl increase to normal levels, the elevated serum K and blood urea nitrogen fall, while accompanying these changes, hemodilution occurs along with a diuresis and further loss of fluid, Na and Cl. When adrenal hormones are lacking, water and salt are not only lost in urine and other excretions but perhaps equally important, are immobilized in cells and tissues. Following administration of potent steroid ample fluid and salt are redistributed to the extracellular and intravascular compartment with complete disappearance of symptoms and return of activity and vigor.

Comparisons are presented on relative potencies of Δ¹-F and a new analogue, 6-methyl-Δ¹-F, on 3 different assays for corticoid activity: anti-inflammatory (granuloma pouch technic), liver glycogen deposition, and sodium retention. 6-Methyl-Δ¹-F is 2 times as potent as Δ¹-F on the anti-inflammatory test and about 3 times Δ¹-F on the glycogen deposition assay. 6-Methyl-Δ¹-F, like Δ¹-F, does not induce sodium and water retention on the assay for electrolyte activity, but in contrast to Δ¹-F, this steroid acts as a diuretic and natriuretic agent.

Serial sections of infected tissue cultures revealed a granuloma due to the proliferation of the vascular sinus endothelium. This reaction was similar to that reported by German authors in describing lesions of granulomatosis infantiseptica, a disease caused by L. monocytogenes. Infected tissue cultures incubated 48 hours or longer required refrigeration for at least 7 days in order to demonstrate the presence of L. monocytogenes.

1) Mitotic activity occurs in adult mast cells of the mesentery of rats after moderate intraperitoneal doses of the histamine liberator, compound 48/80. After larger doses, which cause disintegration of mesenteric mast cells, mitoses are found in mast cells of the subcutaneous tissue. 2) Replacement of cells after disintegration appears to be by heteroplastic differentiation of lymphocytes or undifferentiated mesenchymal cells or both.

A method is presented for estimating binding capacity of serum for radioactive vit. B₁₂. This capacity was found to increase as the concentration of the vitamin was raised. “Bound” vit. B₁₂ measured in this way is not synonymous with that considered bound because it is unavailable to certain microorganisms.

Oxygen consumption was reduced to hypothyroid levels in reserpine-treated euthyroid and hyperthyroid guinea pigs, but no significant changes were noted in the reserpine-treated hypothyroid animals. The evidence presented and discussed suggests that reserpine antagonizes the effect of thyroid hormone on oxygen consumption.

1. Susceptibility of white Swiss mice to infection with H. capsulatum by inhalation of dust aerosol was determined by direct exposure of animals to known positive soil samples. 2. Disseminated histoplasmosis occurred in a large percentage of mice. 3. Naturally contaminated soil samples held 5 and 10 months at room temperature remained highly infectious. 4. Artificially seeded soil cultures were 100% infective to the white mouse at exposures of 1, 2, 4, and 7 days.

1. Tissue cultures of human amnion cells were found to be susceptible to all adenoviruses tested, certain Coxsackie viruses, and herpes simplex virus. 2. Amnion cell cultures were employed in large scale routine testing for viral agents with recovery of 40 strains of adenoviruses types 1, 2, 3, and 5, one type 1 poliovirus, and 6 strains of herpes simplex virus.

1. The enzyme system, choline oxidase, is present in the liver and kidneys of the guinea pig. Activity is low but measurable, as shown using standard manometric technics. 2. Optimum substrate concentration, pH, and assay conditions are presented. 3. The enzyme response versus enzyme concentration was found to be linear over the range tested. 4. The enzyme system in both liver and kidney of the guinea pig is insoluble as shown by centrifugal separation of the soluble and insoluble components of the homogenates in isotonic sucrose. 5. In kidney betaine was found to be an oxidation product by the action of the enzyme on choline.

Injection of 2 billion H. pertussis cells into T. F. female mice increases susceptibility of these mice to cold stress. 2. Susceptibility to cold of pertussis-treated mice is greater than that of adrenalectomized mice. 3. Adrenalectomy of pertussis-treated mice increases susceptibility to cold stress to a greater extent than either treatment alone. 4. Sham-operated animals whether normal or pertussis-treated are neither more resistant nor more sensitive to cold stress than similarly treated but unoperated animals. 5. Cortisone and hydrocortisone protect pertussis-treated mice from cold stress but to a lesser degree than they protect adrenalectomized mice. 6. Increasing the amount of hydrocortisone from 2 to 6 mg has little effect on increasing the protective effect of this drug. 7. Hydrocortisone given to normal mice increases their resistance to cold. 8. It is suggested that while pertussis possibly affects adrenal function, it must in addition affect other functions in the mouse which are also concerned with protection against stress.

Mephenesin and its carbamic acid ester were orally administered to 4 normal males, the plasma levels of the respective drugs were determined at various intervals in each subject for 4 hours following administration of the drugs. Significantly higher and more persistent plasma levels were attained by mephenesin carbamate, as compared to those of mephenesin. No free mephenesin was found in the plasma of those subjects receiving mephenesin carbamate.

Glutamic-dehydrogenase activity of liver and kidney of the mouse and rat was greater when the tissues were homogenized in water than in .05 M phosphate buffer, or NaCl and KCl of equivalent ionic strength. The decrease in activity could be varied by variations in ionic strength of the medium.

With the use of hexokinase, it has been possible to show that the adenylpyrophosphatase from potato does not contain adenylate kinase. The lack of competitive inhibition of ATP splitting by ADP suggests two sites of enzymic activity, one acting on ATP, the other on ADP.

Adenine deaminase activity and adenosine deaminase activity of rat mammary gland homogenates were studied through pregnancy, lactation and involution. Adenine deaminase activity was not apparent in the mammary gland. Adenosine deaminase activity was present throughout pregnancy and lactation, showing maximum activity in the latter stages of lactation.

1. An attempt was made to determine a normal level of enzyme activity in human plasma as measured by the lysine ethyl ester and tosyl arginine methyl ester assays. There was not only a variation in activity from one individual to another, but also variation in one individual from day to day and within one day. 2. When normal blood and blood with marked fibrinolytic activity were compared, no difference in enzyme activity was noted. Therefore, these methods are not suitable clinically for the demonstration of fibrinolytic activity.

Aberrant thyroid follicles have been found in the thymi of female Sprague-Dawley rats. The accumulation of I¹³¹ by such follicles, shown autoradiographically, indicated their functional nature.

Rape oil caused a marked increase in adrenal cholesterol when fed to rats or mice but had little or no effect in rabbits, guinea pigs, chickens and dogs. This contrasts with results obtained by feeding cholesterol since dietary cholesterol tends to be deposited more readily in the latter four species. The differences in response to rape oil do not appear to be due to species differences in digestibility of rape oil.

The changes that occur in the serum protein fractions of the tissue culture medium during growth of 2 rat and one human tumorous cell strains maintained in continuous tissue culture were studied. Electrophoretic studies on the culture fluids by the moving boundary, and as well the paper electrophoresis technics, revealed a significant decrease of the levels of alpha and beta globulins of the serum nutrient during specific periods of growth. These findings are supported by microanalytical data.

Electrocardiograms were made weekly from birth through 5 weeks of age on 35 baby pigs receiving various subminimal and adequate levels of thiamine in the diet. Typical ECG patterns of normal and thiamine-deficient baby pigs are presented and described. Statistically significant increases in PR time, QT time and cycle length occurred in deficient animals. Thiamine-deficient pigs consistently exhibited sinus arrhythmia. First and second degree auriculoventricular block were manifested. Evidence of cardiac hypertrophy occurred in deficient animals.

Evidence is presented that while whole cell preparations of antibiotic resistant staphylococci did not oxidize pyruvate, lysed cell preparations did. Magnesium ions and Mg⁺⁺ plus cocarboxylase, but not cocarboxylase alone, stimulated pyruvate oxidation by lysed cells, but had no effect on the activity of whole cells. Activity of isolated cell free extracts, cell surface components, and chelating ability of tetracycline are being studied.

A factor in the γ globulin fraction of human plasma has been shown to prevent death in mice from Ps. aeruginosa infections, when injected subsequent to the inoculation. Protection was demonstrated in normal mice, and in mice rendered more susceptible to this infection by pretreatment with cortisone, or by subjecting them to thermal trauma. Human serum albumin was without activity.

Tissue heparin contents and mast cell counts were determined on liver, lung, intestine, kidney, spleen and thymus of male rats and rabbits. In most instances, distribution of heparin and mast cells did not follow the same pattern. Rat organs showed higher heparin values, but lower mast cell numbers than the corresponding rabbit tissues.

No evidence has been found that the “Insulinase”-“Insulinase inhibitor” system responds in vivo (rat and frog) to the absence of circulating insulin.

1. In experiments with gastrectomized rats: (a) The probable species specificity of rat intrinsic factor was demonstrated by the failure of a highly purified preparation of hog intrinsic factor to increase the absorption of Co⁶⁰-B₁₂. (b) In consonance with previous observations in pernicious anemia, acidification (pH 1.85) of a mixture of Co⁶⁰-B₁₂ and homogenized rat stomach inhibited the absorption of Co⁶⁰-B₁₂. (c) In contrast to previous observations in pernicious anemia, separate serial administration of Co⁶⁰-B₁₂ and rat gastric juice failed to show that rat intrinsic factor was more effective in promoting the absorption of Co⁶⁰-B₁₂ when it preceded than when it followed the Co⁶⁰-B₁₂. Indeed, no certain effect of rat intrinsic factor was detected whether it preceded or followed the Co⁶⁰-B₁₂ by as short an interval as 30 minutes. 2. In experiments with paired isolated loops of small bowel with intact blood supply created in previously gastrectomized rats: (a) The radioactivity of the wall of the loop perfused with Co⁶⁰-B₁₂ and rat gastric juice was greater than that of the paired loop perfused with Co⁶⁰-B₁₂ and rat gastric juice previously heated to destroy its intrinsic factor activity. No consistent difference was observed with heated or unheated human gastric juice. (b) The absorption of Co⁶⁰-B₁₂ was greater when labelled rather than unlabelled vit. B₁₂ in equal amounts had saturated the binding capacity of rat gastric juice before admixture with an equal amount of the other form of vit. B₁₂ just before the intestinal perfusion. 3. In conclusion, binding of vit. B₁₂ is an important, perhaps indispensable, aspect of the function of intrinsic factor.

1) The hemolysis of normal human erythrocytes exposed to appropriate dilutions of tannic acid by human serum, requires the properdin system, which consists of properdin, complement, and magnesium. 2) Similarities and differences are pointed out between the properties and mechanism of hemolysis of tannic-acid-treated cells and erythrocytes from patients with paroxysmal nocturnal hemoglobinuria. 3) While the hemolysis of TA cells is suitable for the assay of purified properdin it is not reliable for the quantitative measurement of properdin in serum.

Chemical fractionation of a currently available, partially purified streptokinase-streptodornase concentrate yielded a 4-5 fold purification of the streptokinase. The addition of a starch zone electrophoresis to the methods increased the purification to 6-7 fold. Biophysical examination suggested that the protein was largely homogenous, but immunochemical analysis revealed the presence of extraneous antigenic components. Ultracentrifuge examination suggested that streptokinase has a molecular weight of approximately 50,000.

1. We studied the erythropoietic response to anemic plasma of a variety of experimental conditions in the rat. Rats subjected to hypophysectomy, an atmosphere of high O₂, starvation, and transfusion-induced polycythemia have a decreased rate of erythropoiesis and an exaggerated response to the administration of anemic plasma. 2. Treatment with dinitrophenol increases the rate of erythropoiesis and decreases the response to anemic plasma. 3. These findings are in agreement with the hypothesis that the rate of erythropoiesis is determined by the amount of erythropoietin, the production of which is regulated by the relationship between O₂ supply and demand, not by either factor alone.