Experimental Biology and Medicine

24-hour uropepsin excretion levels were found to show a low positive correlation with 24-hour 17-ketosteroid excretion levels in healthy young men. To an even greater degree this is true of the day to night excretion ratios of these two biochemical measures. Since 17-ketosteroid excretion is believed to reflect adrenal cortical activity, the findings point to the possibility that adrenal cortical activity may exert a controlling effect on uropepsin excretion in young men. Older men were found to show a negative correlation in the 24-hour excretion levels of these two measures with a trend toward a similar relationship between the day to night ratios.

Using the granuloma-pouch as an indicator, it has been shown that trypsin, given simultaneously with croton oil, causes particularly intense and widespread tissue-damage in the rat. On the other hand, if trypsin is introduced into the inflamed area 5 days after the croton oil, the granulomatous lining, formed under the influence of this chemical irritant, protects the adjacent tissues against otherwise toxic concentrations of this enzyme. The importance of the time-factor, in determining the effect of trypsin upon inflamed tissue, is emphasized.

Dietary iodinated casein led in chicks given dietary vit. B₁₂ to higher cecal contents of vit. B₁₂ and in chicks not given dietary vit. B₁₂ to lower liver contents of vit. B₁₂ than those found in respective controls. It is suggested that the ability of iodinated casein to increase the sensitivity of chicks to dietary vit. B₁₂ is due in part to an interference with intestinal absorption of the vitamin.

One hundred and four fecal and oropharyngeal specimens obtained directly from human sources were studied in 3 types of tissue cultures. The virus recovery rates among fecal samples were of the same order regardless of the type of tissue culture used. Under the conditions of the study, monkey kidney epithelial cell cultures were superior to HeLa or testicular cultures in the primary isolation of poliomyelitis virus from oropharyngeal specimens, A comparison of tests with fecal samples in monkeys and in tissue culture indicated that the latter was as good as, if not better than, monkeys in detecting poliomyelitis virus.

1. The dietary effect of antibiotics, aureomycin and sulfasuxidine, on phospholipide and nucleoprotein synthesis was studied in rat livers. 2. The addition of aureomycin (25 mg/rat/day for 4 and 8 weeks) to a low protein-low fat diet caused a marked stimulation of growth and food consumption in the rat. However, there were no significant changes in the.liver lipides or the synthesis of phospholipides or nucleoproteins. 3. Addition of 5% sulfasuxidine to a low protein-low fat diet produced a significant lipotropic effect. There was a significant decrease in total lipides and an increase in lipide phosphorylation.

Under conditions favoring the excretion of bicarbonate, the rate of excretion of bicarbonate decreased, while the rates of excretion of other electrolytes increased, during an osmotic (glucose) diuresis. Possible explanations for this observation are discussed in relation to present concepts of osmotic diuresis and of the excretion of bicarbonate.

The innominate bones in virgin mice of the Brown-belt strain were tied together at the pubic symphysis with silk thread. This was done to prevent innominate bone separation and concomitant enlargement of the birth canal during pregnancy. The females were then mated. Each pregnant mouse gave birth to normal living young at the usual time even though its birth canal was not enlarged during pregnancy by innominate bone separation at the symphysis. All of the pelvic joints became flexible, including the symphysis. Although the tied innominate bones remained closely approximated at the symphysis the pre-pregnancy symphysial cartilage was replaced by ligamentous tissue.

1. In dba mice diethylstilbestrol and estradiol benzoate reduce the acute radiation mortality. The androgens, testosterone propionate and depotestosterone cyclopentyl-propionate, afford no protection against acute lethal radiation dose. 2. The estrogens afford protection when given for 7 days before or after the irradiation. 3. No toxic effects due to estrogens or androgens were seen in the administration of the hormones for 7 days after irradiation.

The survival time of mice in 6 atmospheres of oxygen was about 40 minutes. The average survival times were prolonged 12, 22, 34, and 146 minutes, respectively, when the mice were irradiated (8800 r) 30, 48, 72 and 84 hours previously. Anorexia may have contributed to the observed protection.

1. A linear relationship was observed between the urinary osmotic load (mOsm/min.) and the rate of urinary flow (ml/min.) in 7 patients suffering from renal disease. This suggests that osmotic diuresis is the major physiological mechanism regulating the rate of urinary flow in these patients with renal disease. 2. In these patients with renal disease there appears to be a “critical” level of the glomerular filtration I rate, approximately 10 ml/min., at which: a) C_K/C_Cr exceeds 100%; b) V/C_Cr exceeds 15%; c) the antidiuretic response to single intravenous injections of pitressin in physiological dosage (0.57 mU/Kg) is markedly diminished; d) there is an alteration in the relationship between V/C_Cr and the urinary concentrations of sodium, potassium and total solute.

Rabbit pituitaries from animals exposed to 750 and 1100 r of total body Cobalt-60 gamma irradiation showed an early suppression of gonadotropin principles as measured by the chick gonad response. The 750 r group showed the depression on the 8th day after irradiation while in the 1100 r group the suppression was evident by day one and was sustained through day 7. After this time the gonadotropin activity in both groups returned to the normal level.

1. Four hundred and fourteen sera from 4 turkey flocks have been tested by means of hemagglutination inhibition test utilizing a PPLO antigen. 2. This test gives reproducible results and gives promise of being useful in screening breeder flocks. 3. PPLO isolated from chickens and turkeys are apparently antigenically homogeneous with respect to this HI test as based upon 4 strains isolated from widely separated sources.

Treatment of albino rats four times with 100 μg of aminopterin during a 68-hour period resulted in a severely lowered white blood cell count. The treated animals showed a reduced uptake of C¹⁴ formate in intestinal ribonucleic acid while their liver ribonucleic acid showed a markedly increased specific activity as compared with controls.

Metrazol and electrically induced seizure activity in the cortex of kittens at various stages of maturation reveals a relation of form and frequency of discharges to age. Focal and non-focal “spike and wave” discharges of frequencies seen in the EEG of the epileptic human infant and child may be reproduced in young animals. With increasing age spikes of faster frequencies replace this slower “spike and waves”. The findings indicate the importance of electro-ontogenetic studies in investigations of the electrical patterns of epileptic seizures.

1. The ionic strength-electrophoretic mobility relationship of human serum albumin was studied at pH 4.0 in acetate-NaCl buffer over a wide range of ionic strength values. 2. A 5% albumin solution which gave a single boundary at pH 8.6 in barbiturate buffer, 0.1 ionic strength, showed separation into a number of ascending boundaries at an ionic strength of 0.005. 3. Similarly at pH 4.0 in acetate-NaCl buffer, the number of ascending boundaries increases from 2 to 5 as the ionic strength is decreased from 0.2 to 0.02. Under these conditions, the area under the fastest moving peak increases continuously at the expense of the slower-moving peak adjacent to it. 4. Using an ionic strength of 0.03 (pH 4.0) as a standard condition, since it gives 4 clearly resolved boundaries, various other factors which may influence the electrophoretic pattern were studied, e.g., protein concentration, method of preparation of albumin fraction, time of run, and technic of dialysis used. 5. Reproducible values for the areas under each of the 4 peaks were obtained at protein concentrations between 1 to 5% and with mechanical dialysis for 5 hours or longer at 25° against the acetate-NaCl buffer, 0.03 ionic strength. 6. Preliminary work would indicate that the electrophoretic sub-fractionation of other proteins or protein fractions, e.g., gamma globulin, is also possible and that this behavior may be part of a more generalized phenomena. 7. The possible explanation of these phenomena await quantitative analysis of the components present under each observed peak. However, evidence is presented that boundaries probably represent protein components and not artefacts.

The tissues of chick embryos dead or dying following infection with the virus of Japanese encephalitis are significantly lower than normal in pentose concentration but no significant differences in desoxyribonucleic acid concentration were demonstrated. The factors responsible for the decrease in pentose have not been elucidated.

1) Recent application of the atomic pile to the neutron-capture therapy of human brain tumors has focussed attention on the biological behavior of boron compounds. 2) Studies reported in mice and man indicate that borax and boric acid are rapidly absorbed and distributed throughout the body. Uptake by the various organs and tumor describes a family of similar curves such that the faster the rise in concentration, the higher and earlier is the peak. All tissues studied, except brain, reach a peak by 30 minutes. Borate is rapidly excreted by the kidneys as a “low-threshold substance” in a class with urea and sulphate, and clearance from the blood in mice proceeds with an exponential half-time of approximately 65 minutes. 3) Concentrations of borate in the tissues of normal mice are directly proportional to dosage for at least 2 hours after injection over a range of 18 to 700 μg/g body weight. 4) At equilibrium distribution, studied in nephrectomized mice, borate is uniformly distributed throughout the body water, with a 10 to 20% excess bound in the intracellular compartment. This excess is bound more tenaciously in brain than in other tissues and appears to be responsible for the toxicity of these compounds. 5) Study of the factors determining the concentration ratio between neoplasm and surrounding normal tissues indicates that boron-neutron treatment offers little promise for malignant tumors other than those of the brain.

1. In a medium consisting of chicken plasma and amniotic fluid, growth inhibition by soluble F ale. in concentrations from 200 μg/ml can be demonstrated consistently. 2. When EE is added to the culture medium, growth inhibition occurs only in a higher concentration of soluble F ale. The suggestion that EE contains a principle antagonistic to the inhibitory action of F ale. is discussed. 3. Growth of epithelium from stomach and intestine is not affected by F alc., while growth of fibroblasts is suppressed. 4. Reversibility of the effect of F ale. after its removal from the medium, and its selective inhibitory action on fibroblasts indicate that its inhibitory action in vitro is related to its known action in vivo, in particular to the retardation of regeneration in wounds experimentally produced in animals. 5. Aqueous soluble DOC in similar concentrations has an effect similar to soluble F ale. and cholesterol in suspension has a minimal inhibitory effect on cell growth. This observation differs from the in vivo findings and warrants further investigation.

The ACh content of human red cells is less than 0.08 γ/ml and no increase in synthesis can be observed in cells equilibrated with cholinesterase inhibitors. A synthetic rate higher than 6.3 γ/g/hr by acetone powders of red cells was not observed. There is some doubt that the activity observed was the result of enzymatic synthesis of ACh. Calculations show this rate to be less than 1/50 that required to provide the free energy essential for the accumulation of K against a concentration gradient. The metabolism of red cell Ach as a mechanism by which the cells accumulate K is of doubtful importance.

Heat or storage at −18°C is attended by a significant reduction of the susceptibility to clearing of saline washed chylo-micra from plasma. Thoracic duct chyle is affected much less by the same treatments.

Egg-white administration to rats results in loss of plasma from circulating blood. In adrenalectomized rats egg-white injection causes a greater loss of plasma than in intact animals. In animals pretreated with cortisone the loss of plasma is significantly smaller than in unprotected animals. The observations suggest that cortisone may act by preserving capillary function and maintaining plasma volume above the critical level.

1. Intracellular granular metachromasia, appearing in a sequence of two colors, i.e., pink and purple, is a general phenomenon found in a variety of living cells in tissue culture. 2. In tissue culture cells, the appearance of intracellular granular meta-chromasia is evidence of cell viability and intracellular orthochromasia, one more criterion of cell death. 3. Mast cells, or “precursors” of mast cells cannot be specifically identified by supravital metachromasia. 4. Dye condensation effected by an active process in the cell, as one possible factor in producing vital metachromasia, is discussed.

Mixed infection with the viruses of influenza A and Newcastle disease virus was found to result in the formation of some particles which had antigenically mixed surfaces, i.e., which contained components from both parent types. The phenotypic change was transitory and did not appear in the progeny of such a particle. It is suggested that this phenomenon is due to phenotypic mixing.

1. Erythrocyte coproporphyrin and protoporphyrin levels have been determined in normal newborn infants and older children. 2. There is a significant elevation of EP in children as compared with normal adults. This increase probably reflects the general iron deficient state in children. 3. There is a significant elevation of ECP in newborn infants as compared with normal adults. This increase probably reflects increased erythropoiesis in utero and rapidly disappears by the fourth and fifth day of life. 4. The EP and ECP should be regarded as abnormal if they exceed twice the standard deviation above the mean.

1. The effect of ovariectomy, adrenalectomy, and hypophysectomy upon growth of spontaneous tumors in mice has been studied. 2. Bilateral adrenalectomy alone or combined with ovariectomy produced a complete regression of the tumor in 3.3% and 3.7% of the mice respectively. Hypophysectomy was followed by regression in 11.5%. of mice. 3. All groups in which either adrenalectomy or hypophysectomy was performed, showed a shorter survival time than unoperated controls, even in those mice showing a complete regression of their tumors.

1. Sera of 7 patients with coronary occlusion and myocardial infarction and of one patient with coronary insufficiency and myocardial necrosis were positive for CRP. 2. Sera of 6 patients with coronary insufficiency but without myocardial necrosis were negative for CRP. 3. These preliminary observations suggest that the CRP test may be a sensitive indicator of myocardial necrosis and inflammation.

1. A rapid method for determination of lipide-C¹⁴ in experiments in which liver slices are incubated with C¹⁴-labeled compounds is described. 2. Data on the reliability of the procedure, and a comparison of values obtained by this simplified procedure with those obtained by the previous laborious methods are presented.

Canine distemper inclusion bodies in urinary bladder epithelium were specifically stained with fluorescein-anti-body conjugate. On the basis of this finding it is concluded that these inclusion bodies contain viral antigen.

1. A method is described for the determination of the respiratory rates of tissues in contact with oxygen by supporting them in the gas phase on fiber-glass mats in a modified wide-mouthed Warburg flask. 2. Investigated in this way the tissues maintained a satisfactory physiologic state as evidenced by slow decline in respiratory rate and negligible changes in pH. 3. For 8 rat tissues studied the respiratory rates on mats were considerably higher than those in Krebs-Ringer-Phosphate; and higher than those in Krebs Medium III in the case of muscle, brain, kidney, and heart, lower only for spleen, and not significantly different for liver, intestine, and testis. 4. Application of the respiratory rates to summated tissue calculations yielded the following values relative to BMR: on mats, 101.8%; in Krebs-Ringer-Phosphate, 78.7%; and in Krebs Medium III, 90.7%. 5. The utility of the technic using mats as a means of avoiding the variables due to different liquid media is discussed.

1. Eighteen 24-hour urine samples collected from one woman during nulligravid, gravid and lactating periods, were analyzed for the free indispensable amino acids—leucine, isoleucine, valine, histidine, lysine, methionine, phenylalanine, arginine, threonine and tryptophan. The excretion level for each amino acid increased from the nulligravid to the gravid state, evident as early as the second month of gestation. Excretion of threonine continued to increase during gestation while methionine fluctuated slightly from the non-pregnant value. The other 8 amino acids showed a decreased excretory level during the fourth and fifth months of gestation. From the sixth to the ninth months, excretion levels of most of the amino acids increased slightly or remained fairly constant. 2. During lactation, the excretion level for each amino acid is less than that for pregnancy or non-pregnancy. 3. Threonine, histidine, lysine and tryptophan showed the greatest changes from one phase of the reproductive cycle to another. 4. While trends of amino acid excretion were similar from one pregnancy to another, the quantities excreted in relation to duration of gestation were different.

These studies show that the soluble substances produced by P. pestis when grown at 37°C in a completely defined medium are capable of producing a high degree of protection when injected into mice. Further studies to determine the optimal conditions for growth and antigen production are necessary and are in progress.

In previous studies, it has been shown that in many instances the normal resistance of mice of an inbred strain to homo-grafts of a tumor can be abrogated by injecting the host with an extract of tumor tissue. It is here shown that such an injection must be given prior to tumor inoculation, or at most one day after inoculation, to obtain loss of resistance. The effects of such a procedure persist for long periods, as shown by progressive growth of tumor homografts in 80-100% of mice grafted approximately 5 months after receiving injections of tumor extract, and in at least 50% of the mice grafted up to 10 months after treatment with extract.

Vit. B₁₂ activity of whole blood and plasma from the human, dog, calf, rabbit, chicken and alligator was studied before and after alkaline hydrolysis. The data show a wide variation of blood and plasma vit. B₁₂ content between the different species. In mammals, the vitamin is almost equally distributed between the erythrocytes and plasma. In chicken and alligator, the major portion of the vitamin activity is associated with the nucleated erythrocyte.

1. The pharmacological properties of a new alkaloid, rescinnamine, recently isolated from Rauwiloid®, have been described. Rescinnamine produced typical pharmacological effects of Rauwolfia serpentina: bradycardia, hypotension, and sedation, as well as characteristic alterations in cardiovascular responses, 2. Rescinnamine caused augmentation of pressor response to epinephrine, reversal of pressor response to .hypoxia, diminution of pressor response to bilateral carotid occlusion, and blockade or reversal of primary blood pressure rise elicited by faradization of afferent vagus. 3. The sedative effects of rescinnamine were demonstrated by gross observation in dogs, rats and mice and by prolongation of pentobarbital-induced sleeping time in mice. 4. Rescinnamine produced marked eyelid ptosis in mice and a copious nasal discharge in rats. 5. On a weight basis, rescinnamine appeared to be several times as potent as Rauwiloid® and similar to reserpine. 6. Rescinnamine is the second highly potent alkaloid derived from Rauwolfia serpentina.

1. Growth of adult human uterus and human embryonic skin and muscle tissues in roller tube cultures is supported by media containing 90% of either bovine allantoic or bovine amniotic fluids. 2. Amniotic fluid medium produces a profuse outgrowth of clear cells, and does not affect the plasma clot; whereas allantoic fluid medium tends to produce wrinkling and darkening of the clot, and induces granularity in a less profuse outgrowth of cells. 3. Either fluid, used alone as the medium, permits the cultivation of Type 2 poliomyelitis virus.

Plasma, serum, and embryonic extract contaminated with gram negative and non-sporeforming gram positive bacteria have been shown to be sterilized by a dosage of 2 × 10⁵ rep of gamma radiation from Cobalt-60. Such treatment failed to alter the properties of these materials as related to their use in tissue culture work. These studies are being extended to cover dosages necessary to kill bacterial spores and efforts are being made to put the work on a more quantitative basis by utilizing established strains of tissue culture cells for assay procedures.

1. Preliminary treatment by mouth with a large dose (50 mg) of streptomycin increased the susceptibility of mice to infection following oral inoculation with a streptomycin-resistant strain of Salmonella enteritidis. In mice treated with streptomycin 24 hours before inoculation, <3 Salmonella sufficed to initiate infection in 50% as compared with approximately 10⁵ in untreated controls. 2. This effect of streptomycin decreased as the interval between treatment and inoculation was lengthened but was still detectable on the 5 th day. Smaller doses of streptomycin (5-10 mg) resulted in smaller increases in susceptibility. 1 mg was ineffective. 3. Representative numbers of mice killed for culture showed the spleen to be infected in 90% and heart's blood in 72% of those with positive fecal cultures at the time of autopsy. 4. It is believed that this increase in susceptibility following streptomycin treatment resulted from a disturbance of the normal intestinal microflora caused by the antibacterial action of the drug. 5. It is suggested that this method may be applicable to the experimental study of other enteric infections.

1. Chromatographically pure I¹³¹ labelled 1-thyroxin was added to surviving kidney slices which were incubated in a modified Krebs-Ringer phosphate solution. 2. Following incubation, the slices were homogenized, extracted with butanol and the thyroxin and triiodothyronine separated and identified by paper chromatography. 3. The triiodothyronine was found to be radioactive. This was taken as evidence of deiodination of thyroxin to triiodothyronine. 4. Conversion of thyroxin to triiodothyronine was reduced by excess iodide and abolished by boiling the tissue or by the addition of potassium cyanide to the media.

A method of assay for a growth factor required by L. bifidus of avian origin has been developed. The factor is found in low amounts in isolated proteins and animal products, in higher amounts in plant materials, and in highest amounts in fermentation products, yeasts and bacterial cultures. The growth factor was not found in concentrates of liver, whey and fish solubles which were potent sources of unidentified chick growth factors. Chemical and physical properties of the L. bifidus factor are described.

The effect of the administration of β, β-diethylalanine (DEA) upon the composition of rat livers has been studied. Feeding DEA to male rats resulted, at the higher of 2 levels, in lower liver lipide and higher liver water and protein content than in controls. Injections of massive doses of DEA were without significant effect. The implications of these results with respect to similar studies with ethionine are discussed.

The minimum daily dose of aldosterone when administered in 10% alcohol to adrenalectomized dogs is approximately 10 μg/dog/day; the dose of the free alcohol of desoxycorticosterone required is 250-125 μg/ day. Thus, aldosterone is about 25 times more active than DOC. The new steroid in low dosage is less efficient in regulating the serum K level than it is in maintaining a normal level of serum Na. Hyperpotassemia and symptoms of adrenal failure may be present in dogs presenting normal levels of serum Na. A larger dose of this mineralocorticoid is required to maintain a normal level of arterial pressure than is necessary to maintain a normal serum electrolyte pattern. Aldosterone appears to possess certain physiological properties which distinguish it from desoxycorticosterone compounds.

In 41 patients with rheumatoid arthritis, who were studied before and during the administration of cortisone, serum muco-protein and the protein-bound carbohydrate concentrations were studied and compared. 1. The correlation coefficient of the 2 tests was found to be moderately high, r = 0.62. 2. It was found that when the total protein sugar concentration was very high, mucoprotein concentration was always above normal values. 3. When the total protein sugar concentration was normal, the serum mucoprotein index was often above normal. 4. From these findings and from the comparative study of the variation of total protein sugar and mucoprotein concentrations during the treatment of 6 patients with cortisone, it is suggested that a common factor regulates the formation of serum mucoproteins and other plasma proteins which are rich in carbohydrate.

Exposure of rats to equal volume dose of x-radiation (200 kg roentgens) through grids having various diameter hole sizes but a constant open area to closed area ratio resulted in increasingly greater survival as the grid hole sizes were decreased. Significantly greater survival was obtained in rats exposed through grids than in rats exposed to total body x-irradiation. It is suggested that these results may be explained by a beneficial local effect of partial shielding whereby normal tissue adjacent to irradiated tissue initiates repair in the irradiated areas. Degree of survival appeared to be directly related to the area of interface between normal and radiated tissue.

1. Normal goldfish, Carassius auratus accumulate a peak of 3% of an injected tracer dose of I¹³¹ intrathyroidally. This small amount of radioiodine remains in the thyroid at the same level for more than a week. Thyroids of thyrotropic hormone-injected goldfish accumulate 9% or more of the tracer I¹³¹, but lose at least 40% of it within a week, indicating a greater turnover rate. 2. Radioiodine in normal goldfish thyroids is mostly in the form of monoiodotyro-sine and diiodotyrosine, with little, if any, thyroxine formed even after one week. The thyrotropic hormone stimulated goldfish thyroid forms a small proportion of radiothyrox-ine as early at 24 hours after injected I¹³¹ and as much as 8% of the I¹³¹ is in the form of thyroxine by 7 days after injection of I¹³¹. 3. Keeping the goldfish in water low in iodine had an effect on¹³¹ metabolism similar to thyrotropic hormone treatment.

1. Rats irradiated in a hypoxic atmosphere show a slightly higher cellularity and much greater rate of DNA synthesis in the bone marrow and spleen after 96 hours than rats irradiated at ground level. 2. Thirty hours of intermittent hypoxia preceding irradiation at low oxygen tensions does not give additional protection. 3. A striking parallelism exists in the cellular reactions in the bone marrow and spleen following irradiation, both at normal atmospheric pressures and at low oxygen pressure. 4. Irradiation of animals at low oxygen pressures appears to reduce the biological effectiveness of 800 r on the bone marrow to 600 r.

A significant protection against the injurious effects of P³² was observed by the administration of pantothenic acid to mice on a deficient diet. Pantoyltaurine was almost as effective in this respect as the natural vitamin.ω-methyl pantothenate was totally ineffective.

Mice acclimatized to one altitude (350 mm Hg) showed an increase in performance when exposed to a higher altitude (247 mm Hg) as compared with ground level controls. When acclimatized mice are bled they showed a decrease in their performance level. This decrease in performance is not in proportion to the blood withdrawn indicating that an increase in hemoglobin concentration is probably not the sole criterion for an increase in performance at altitude.

Diethylstilbestrol, progesterone and DOCA induced in vitro hemolysis of human “O” erythrocytes. The hemolytic activity of stilbestrol was modified by temperature, pH, human serum, or the addition of non-hemolytic corticosteroids. Prolytic loss of potassium from stilbestrol-treated cells was demonstrated.

In 3 experiments adult golden hamsters fed a fortified bread ration containing 5% polyoxyethylene sorbitan monolaurate (Tween 20) for from 8-20 weeks showed a consistent increase in gastrointestinal absorption of a test dose of radioactive iron (Fe⁵⁹) during the subsequent 3 days. Increases in the isotope were noted especially in the cecum and large intestine, the blood, bone marrow, and liver. Concomitantly less radioactive iron appeared in the excreta of the Tween fed animals than in the excreta of control animals. This evidence of increased iron absorption in the hamsters was accompanied by the presence of iron pigment in the cecal mucosa, mesenteric lymph nodes and liver and by an increase in chemically demonstrable iron in the cecum and liver.

An intradermal test for detecting resistance to infectious canine hepatitis is described. Sixteen of 17 animals showing negative tests were susceptible to the disease. Fourteen of 16 positive reactions were resistant to experimental challenge. The test apparently has a much greater sensitivity than the complement-fixation test.

1. Bunyamwera virus was grown in roller-slide tissue cultures of human lymph nodes (fibroblastic type cells). Propagation of virus was demonstrated by increases in virus titers in short-term virus growth studies, by long persistence of virus in tissue cultures as contrasted with rapid disappearance in cell-free preparations, and by persistence of virus after serial passages had diluted the original virus inoculum far beyond its minimal infective dilution. 2. Similar but less extensive studies demonstrated the propagation in human fibroblast tissue cultures of West Nile, Egypt 101, Ilheus, and Br I viruses. 3. Bunyamwera virus showed changes interpreted as an adaptation phenomenon during serial passages in tissue cultures. These changes were reversed by serial intracerebral passage in mice. 4. None of these viruses caused appreciable cytopathol-ogy under these experimental conditions, even after prolonged growth in tissue culture. 5. Bunyamwera, Egypt 101, and Ilheus viruses were also grown in tissue cultures from various human cancers. It was not possible to determine whether virus was propagating in the cancer cells, or in nonneoplastic stromal cells. 6. Egypt 101 virus propagated in cells from an immune patient, but not in the presence of immune serum.

When mice were inoculated with 3 carcinogenic compounds, they developed a transient antineoplastic (AN) response which was demonstrable by tissue culture technic. This AN phenomenon appeared to be chemically and genetically specific. The duration of the AN response to the 3 agents may represent the latent period of carcinogenesis, since the AN phenomenon disappeared when the tumor emerged. The interpretation of the AN phenomenon on an immunological basis is discussed.

1. Topical protection against hyperergic inflammation by a preceding local inflammation, and topical protection against thermal injury by a preceding local thermal irritation can be demonstrated even in rats adrenalectomized before pre-irritation. 2. Acquired topical protection, therefore, is not likely to depend upon the topical extravasation of antiphlogistic corticosteroids into preinflamed areas.

Criss-cross passages between mice and tissue cultures resulted in the adaptation of Type 1 (Mahoney) poliomyelitis virus to the intracerebral route in mice.

Antibiotic JM-57h a wide spectrum agent, has been used to combat post-irradiation infection without significantly increasing the total number of survivors. In the group medicated daily an increase in the ST₅₀ day was noted. The results obtained indicate that medication must be started during the first post-irradiation week before massive bacteremia occurs, otherwise such therapy will not be beneficial. At a dose of 0.1 of its LD₅₀, antibiotic JM-57h was well tolerated and produced no fatalities or untoward reactions in CF-1 strain mice.

1. Myochrysin interfered with the therapeutic activity of subtilin in the experimental β hemolytic streptococcus infection of mice. 2. The myochrysin dose required for interference increased with the amount of subtilin used (it varied between 12.5-40 mg/kg). 3. In the Borrelia duttoni infection of mice, subtherapeutic doses of one drug interfered with the therapeutic action of the other, while therapeutic doses of both drugs acted synergistically. 4. Analogously, in the Borrelia obermeieri infection, both interference and synergism were noted. 5. The effect of the combined treatment in the spirochetal infection may vary at different time intervals following treatment.

When adhesions are created between the heart and a lung the pulmonary artery of which has been ligated, abundant large connections develop between the coronary arteries and vastly expanded bronchial arteries. The efficiency of these connecting vessels as collateral blood supply to the heart is under investigation.