Experimental Biology and Medicine

A technique for studying the pharmacology of vascular smooth muscle has been described. This technique utilizes pulsed tension rather than the static tension customarily employed and has permitted the following observations: Contraction responses to the catecholamines have shown accelerated onset and recovery with increased uniformity of response. A differential sensitivity to norepinephrine has been shown to exist in segments taken from different parts of the same aorta. A progressive reduction in sensitivity to norepinephrine was observed from the arch to the origin of the superior mesenteric artery.

The possible storage of estrogenic substances in brains of rats treated with ethynylestradiol (EE) or its 3-cyclopentyl ether (EECPE) was investigated. Twenty-four or 72 hours after a single oral administration of 2 mg of the test steroids, brains were removed and extracted with methylene chloride. The extracts were bio-assayed for uterotrophic potency or subjected to thin layer chromatography. Uterotrophic activity, corresponding to 2.3 and 0.5 μg of the standard, was detected 24 and 72 hours after administration of EECPE. This material corresponded to authentic EECPE in two TLC systems. Similar chromatographic analyses showed that the estrogenic substance, previously detected biologically in body fat of rats treated with EECPE(1), likewise corresponded to the unaltered ether. Neither bioassay nor TLC detected any estrogenic substances in brains or fat of rats treated with EE. The evidence supports the view that EECPE, but not EE, is stored unaltered in brain and body fat and that such storage may account for the enhanced anti-gonadotrophic and uterotrophic potency of the etherified form of the steroid.

Evidence has been presented through the use of doubly-labeled β-carotene and singly-labeled retinol that β-carotene is converted to product(s) other than retinol.

Adult guinea pigs immunized with the live Tacaribe virus are able to resist challenge with a large dose of Junin virus to which they are normally susceptible. Sera from the Tacaribe virus-immunized guinea pigs contain abundant homologous antibody demonstrable by both complement-fixation and plaque neutralization tests. The complement-fixing antibody titers of these sera with the heterologous Junin antigen are moderately high. However, the amount of antibody determined by the plaque neutralization test with Junin virus is negligible.

Studies indicate that PAH accumulation by thin slices of rabbit renal cortex shows a sharp pH optimum at 8.1 to 8.3. At the pH optimum, acetate does not show stimulation of PAH uptake that is characteristic of its effect at physiological pH. The displacement of previously accumulated PAH does not show a sharp pH dependence.

Actinomycind inhibits cell proliferation in control cultures of embryonic bone and prevents the stimulation of bone resorption by parathyroid hormone (pth) or vit. a. with a dose of 0.004 μg/ml of actinomycin d, pth effects are only partially inhibited and this inhibition can be overcome by increasing the dose of pth. these findings suggest that these agents act competitively.

Evidence is presented which further indicates that under specific conditions chondroitin sulfate A will act as a growth stimulating agent. Effective in tissue cultures in concentrations as low as those ascertained for several hormones, production of RNA, DNA and phospholipid is increased simultaneously within a few hours after application (the total extractable phospholipid is reduced indicating an increased rate of turnover), but the stimulating effect is gone by 24–48 hours. The demonstrated action of small amounts of chondroitin sulfate A in several types of cells, together with the finding that this material is normally present in human plasma in such amounts suggests that it may be a metabolic agent in the regulation of cell processes.

Estimates of the different forms of hydroxyproline in blood serum were made by methods which now account for all of the hydroxyproline. In micrograms per milliliter of serum they are: total, 10.1; as protein, 7.1; dialyzable, 3.0; free, 2.3; peptide, 0.7; prolylhydroxyproline, 0.12. The latter represents only 1% of the total hydroxyproline of serum whereas it is about 50% of the total in urine.

Despite numerous investigations [see (1) for review] little information is available on the role of blood ceruloplasmin in body function in general or its relationship to copper distribution and metabolism. It has been known since the discovery of Wilson's disease that the central nervous system is particularly sensitive to a disturbance in copper metabolism, although the significance of low ceruloplasmin to the condition is unknown. With the important finding that a copper deficiency state could be produced in animals maintained on a diet containing high molybdate and sulfate, an experimental technique became available for studying the relationship of copper to neurological function. Ewes maintained on a similar diet gave birth to lambs with sway back disease, a demyelinating condition presumably similar to Wilson's disease(2). It was the objective of the present study to determine the effects of a high molybdate and sulfate diet on blood ceruloplasmin in an effort to help elucidate the role of this copper protein.

Materials and methods. Twenty-four white albino rabbits, 14–15 weeks old, were maintained on an intake of 0.05% molybdenum, as sodium molybdate (Na₂MoO₄ · 2H₂O) and 1.8% sulfate, as sodium sulfate (Na₂SO₄) mixed with a Purina rabbit dry ration containing 2 mg % copper. Deionized distilled drinking water was provided, ad libitum.

The weight of the animals, the level of total copper in blood, serum oxidase activity, hemoglobin levels, and alkaline phosphatase levels were examined weekly. Tissue copper determinations were performed after 10 weeks on one-third of the animals, while the rest of the determinations were made after death.

The copper content of the blood and tissue was estimated by a slight modification of the method of Eden and Green(3) with extreme care being taken to avoid contamination by heavy metal.

Histochemical assay of aminopeptidase (LNA and ANA) of granulation tissue in healing wounds of scorbutic and control guinea pigs did not show any significant difference of aminopeptidase activity in fibroblasts in both conditions. This would indicate that the enzymes involved in the histochemical reaction would be related to processes of cell growth and proliferation rather than to the characteristic secretory activities of these cells (collagen precursors and mucopolysaccharides of the ground substance).

Diploid human cell cultures of embryonic lung origin were stained for acid phosphatase after infection with type 1 polio-viruses in presence and absence of cortisone. Focal distribution of enzyme in untreated cells was changed to diffuse pattern with virus infection, and the incidence of such stained cells was depressed by cortisone treatment, as was viral cytopathic effect. Extent and distribution of cytopathic effects and arrangements of cells exhibiting normal and altered acid phosphatase staining was correlated under varied conditions of distribution of viral infection.

The renal hemodynamic effects of mannitol were studied in dogs by infusing one kidney in situ with a controlled sinusoidal flow pump, observing changes in pressure, and calculating changes in renal vascular resistance. Intravenous infusions of hypertonic mannitol consistently resulted in diminished renal vascular resistance, both before and after blockade of renal nerves and autonomic ganglia. Decreased renal vascular resistance was also addition of mannitol, dextran, and after addition of mannitol, dextran, or saline into the renal perfusion circuit. When hind limb vascular resistance was measured, it too was decreased by intravenous mannitol. These decreases in vascular resistance correlated with diminished hematocrits of the perfusion fluids. In cross circulation experiments in which whole blood from a donor dog which had received mannitol or dextran intravenously was used as the renal perfusion fluid in the recipient dog, decreased renal vascular resistance was observed. However, when whole blood was infused intravenously to intact preparations, renal resistance was not lowered.

These results are considered consistent with the hypothesis that the decrease in renal vascular resistance produced by hypertonic mannitol is not mediated via the autonomic nervous system and is probably due to a combination of decreased blood viscosity and renal vasodilation. The former results from decreased hematocrit, and the latter may be due to decreased transmural vascular pressure associated with diuresis or the presence of a circulating renal vasodilating substance.

ATEe esterase activity can be precipitated from fresh human serum by dilution of the serum with distilled water and adjustment of pH between 6.8 and 7.4. The activity of this fraction of serum is not enhanced by addition of streptokinase. Its properties are closely similar to those of C’1 esterase activity of serum. Human serum also contains an inhibitor, which is precipitated from diluted serum by adjusting the pH to 5.2. The inhibitor combines reversibly with ATEe esterase. Preliminary studies show striking depletion of the activity of ATEe esterase in parenchymal liver disease and in long standing diabetes mellitus.

The vascular removal and organ uptake of incompatible sheep red cells labeled with Cr⁵¹ was studied in mice with either normal, hyper functional or hypofunctional phagocytic states in an effort to ascertain the mechanism of their altered immune responses. RE hyperfunction, induced by glucan, was associated with an enhanced vascular removal of the foreign red cells due exclusively to an increased liver uptake. Conversely, RE depression, induced by methyl palmitate administration, was associated with decreased vascular clearance due to a failure in phagocytosis by both liver and spleen. The present studies not only indicate that the previously observed alterations in hemolysin formation in mice with altered RE activity is associated with both a change in vascular clearance and organ distribution of the foreign red cell, but also demonstrate the ability to control the fate of colloids and particulate antigens by purified chemicals which influence the behavior of macrophages.

The ability of heparin to inhibit both kallikrein and Pf/dil was demonstrated. Since about 6 times as much heparin was required to inhibit kallikrein as Pf/dil, it was possible to determine the amount of each in an unknown solution from the per cent inhibition produced by a given amount of heparin. Using this method, the nature of the permeability activity of diluted serum was investigated and found to be caused solely by Pf/dil.

The localization of soluble and insoluble collagen fractions during the development of normal chick embryo tendon and granulation tissue in injured adult chick tendon was studied by the immunohistochemical technique. Antisoluble collagen antibody reacted only with the cytoplasm of young fibroblasts and with extracellular young collagen fibers. Reticulin fibers which precede the collagen and interfibrillar mucopolysaccharides did not react nor did other tissue structures. Antiinsoluble collagen antibody did not react with fibroblasts and reticulin fibers but did react with collagen bundles.

Intracisternal injection in rabbits of endogenous (leucocytic) pyrogen prepared from rabbit leucocytes in vitro causes a high and sustained elevation of body (rectal) temperature, accompanied by prolonged depression of heat-loss mechanisms (panting and ear blood flow). In paired experiments, the same dose of endogenous pyrogen always caused a much greater increase of body temperature when given intracisternally than when given intravenously. The evidence strongly supports an hypothesis that endogenous pyrogen has a primary site of action in the central nervous system.

The normal urinary protein of rats of 3 inbred strains and one non-inbred stock was examined by gel filtration and ultracentrifugation. A considerable portion of the total urinary protein was found to be of low molecular weight, especially in the males. In the case of male rats of the Buffalo strain, the major urinary protein fraction isolated by gel filtration and two subfractions of it prepared by ion exchange chromatography had molecular weights of the order of 15,000.

Dogs and pigs were injected intravenously with crystalline hog amylase. Clearance of the amylase from the serum was associated with a rise in the level of the blood glucose. Simultaneously, the amylase activity of the liver rose and its glycogen content fell. The results in both species of animals were almost identical.

Free radioiodinated amino acids are released into the medium during a 3- to 6-hour period of incubation with ¹³¹I of intact thyroid lobes from severely iodine-deficient rats or of isolated beef thyroid follicular cells. MIT and DIT are found in the medium primarily in peptide-bound form, but T₄ and T₃ are apparently found only as free amino acids. T₄ enters the medium more readily than T₃.

1) A group of 8 rabbits was shown to have significantly higher rates of phagocytosis when young and small than when fully matured. However, after the animals achieved a weight of 3.5 kg, further gains in weight did not significantly decrease phagocytic activity. 2) Two groups of 8 and 6 rabbits respectively were given casein injections as used previously to induce amyloidosis. Both groups showed a pattern of accelerating and then decelerating phagocytic activity over many weeks. One group was sacrificed while phagocytic indices were still quite high. The animals in this group showed no evidence of amyloidosis. The second group of animals, sacrificed only after phagocytic indices had returned to control levels, showed definite amyloid deposition. 3) The possible relationships between amyloidosis and the R.E.S. were discussed.

Adjuvant arthritis is suppressed in sham-operated rats sensitized with adjuvant mixtures containing BSA. In neonatally thymectomized rats, in whom sensitization to BSA fails to occur, there is a moderate reduction in the intensity of the arthritis observed. In similar animals given lymph node cells at or just after the time of sensitization, the response to BSA is normal; yet the arthritis response is like that in animals not receiving cells.

Alligators cooled for 24 hours (3–4°C) show a significant drop in red cell volume and in venous and circulatory hematocrits when compared with animals held at room temperature (24–25°C). These parameters are lower than those observed in animals cooled acutely (in 30 minutes) to the same temperature. The principal organ taking up red cells is the spleen although other organs, liver, lungs, stomach, and intestines also take up extra cells. Shifts in plasma are small and for the most part not significant. In spite of these changes, the final distribution of cells and plasma in the circulation is not affected by prolonged cooling.

A continuation of previous studies on the protective effects of various substances against acute hydrazine toxicity in mice has revealed several interesting structural features which are consistent with the provisional interpretation that the protective actions of L-arginine and L-ornithine can be attributable, at most, only in part to their roles in ammonia detoxication via urea biosynthesis in liver. That the protection against lethality which they afford also must have another basis is suggested by the finding that citrulline exerted no protective action, while α,γ-diaminobutyric and α,γ-diaminopropionic acids and several diamines did. Likewise, α,γ-diaminobutyric, which was more effective against hydrazine than arginine or ornithine, gave no protection against ammonia poisoning under the same condition under which the latter substances showed their typical effects. The experiments indicate that for an aliphatic amine to have a protective action it must have at least 2 amino groups, and that for a diamino-monocarboxylic acid to be protective the amino groups must be separated at the most by 4-carbon atoms.

The present study compared the dose-mortality curves of sensitized rats kept under conditions standardized for periodicity analysis and challenged with an antigen at 4-hour intervals during a 24-hour period. There were no differences in susceptibility to lethal anaphylaxis in relation to time of challenge. The findings are discussed in terms of circadian variations in pituitary-adrenocortical function.

The Coxsackie B1 virus used in this experiment was unusually virulent for adult “Swiss albino” mice; approximately 15% of the infected animals died and the survivors were severely ill. However, following gonadectomy the death rate fell significantly. This protective effect of castration was not sex-linked and was no longer present 30 days after surgery. Possible hormonal mechanisms responsible for this altered susceptibility are discussed.

The calcium and phosphorus contents of the ash of femora, mandibles and teeth were determined in 230 fetuses, aged 5–9 months, in areas supplied by drinking water containing about 0.1 ppm F (low), 0.5–0.6 ppm F (medium) and about 1 ppm F (high). Significant differences in the mean calcium content of bone and tooth ash, depending upon fluoride intake of the mother during pregnancy from the drinking water, without any change in the mean phosphorus content, were demonstrated. In the low-fluoride area the mean calcium content of the bone and tooth ash of the younger fetuses was lower than was found in the older fetuses, whereas in medium- and high-fluoride areas no such difference was found. The observed differences in Ca/P ratios of the hard tissues of the fetus may possibly be due to the different constitution of the precipitated apatitic calcium phosphates.

The ingestion of soluble ferritin-antiferritin complexes was studied by parallel immunofluorescent, electron microscopic and isotope trace labeled antigen methods. The complexes were ingested by guinea pig spleen cells or mouse peritoneal macrophages. The degree of cellular activity demonstrated by these techniques was dependent on the degree of antigen excess used in preparation of the complexes, the source of antisera and the particular methodology applied.

The number of hemolysin-forming cells, assayed by Jerne's technique in spleens removed from AKR mice, 48 hours after immunization with heterologous red cells, is significantly higher when antigen is administered in conjunction with an enzymatic digest of calf thymus DNA. This stimulation by oligodeoxyribonucleotides is not matched by comparable effects of oligoribonucleotides; mixtures of monodeoxyribonucleotides or -sides are inactive. The stimulation appears to involve a stimulated multiplication of early appearing, or early activated, antibody-forming clones, and is more difficult to discern as the interval between immunization and assay of spleen cell populations increases. Oligodeoxyribonucleotides do not stimulate early immune responses unless specific antigen is administered concurrently; possible reasons for this requirement of antigen, in contrast to a lack of such requirement in comparable stimulations produced by bacterial endotoxins, are considered. The influence of dosage and route of administration of DNA digest have been analyzed and an effect on secondary as well as primary responses has been demonstrated. Kinetin riboside abolishes the stimulatory effects of oligodeoxyribonucleotides without influencing the basic, non-stimulated immune response, whereas Actinomycin D interferes with the immune response in the absence and presence of oligodeoxyribonucleotides. Possible relationships to problems of natural and adjuvant-elicited stimulations of antibody production have been discussed.

Three groups of male Sprague-Dawley rats, control, partially hepatectomized and chronically poisoned with CCl₄, were injected with 1 mg/kg epinephrine in oil. Plasma FFA and blood glucose were measured over a 4-hour post-injection period. Control animals showed the usual hyperglycemic and hyperlipemic response to epinephrine within the first hour after injection. Blood glucose and FFA were back to pre-injection levels at 4 hours. After partial hepatectomy, pre-injection blood levels of glucose were normal but FFA concentration was elevated. The hyperglycemic response to epinephrine was normal but the FFA response was markedly altered. A further elevation in plasma FFA was observed after 1/2 hour and these high levels persisted during the entire 4-hour post-injection period. Chronic CCl₄ induced liver damage elicited a different kind of epinephrine response. There was an abnormally sustained hyperglycemia during the 4-hour post-injection period but the plasma FFA never showed any elevation above pre-injection levels. The data suggest that CCl₄ damages most liver cells in such a way as to lead to abnormal storage of lipids with a consequent increase in utilization of plasma FFA. Partial hepatectomy, however, reflects a diminution below a critical mass of relatively normal cells and total triglyceride synthesis is not sufficient to utilize the plethora of plasma FFA elicited by epinephrine treatment. It is possible that the two types of liver damage may be distinguished in this way.

A viremia and subsequently HA-I and neutralizing antibodies were found in each of 2 human subjects injected with H-1 virus, indicating that the human is susceptible to, and can support, the proliferation of this agent. Studies of blood samples from one of the 2 individuals indicated that the viremia had a cyclic pattern.

Subcutaneous injection of H-1 virus in adult hamsters produced a cyclic-type viremia and the appearance of titratable HA-I and neutralizing antibodies while viremia was still present.

Using the vinyl acetate corrosion technique, enlargement of the coronary arteries in white rats subjected to hypoxia was demonstrated before changes in hematocrit or heart size.

In 9 healthy men doses of Arginine-8-Vasopressin and Lysine-8-Vasopressin from 5.5 to 20 mM which produced decreases in free water clearance (ch₂o) of 4 to 112% had no significant effect on calcium or sodium excretion.

Conjunctival scrapings from volunteers experimentally infected with TRIC agents and from patients with spontaneous eye disease were examined by immunofluorescence. Brightly fluorescing inclusions were demonstrated with hyperimmune TRIC anti-sera. The findings were compared with those obtained by Giemsa stain, iodine stain or isolation of the infectious agent in embryonated eggs. Immunofluorescence appears to offer an improved method for laboratory diagnosis of TRIC infections.

The results presented above show that the selective counting of one or the other of 2 cell types, differing with respect to volume present in the same suspension, is possible with the aid of an electronic counter. This is accomplished by electronically screening out smaller or larger cells from the desired counting interval. From knowledge of the proportion of cells expected to be present within the limits of that counting interval, the total number of cells of a particular type present can be computed. The applicability of this discriminative counting procedure depends in large part on sufficient volume differences among the cell populations present. In the event the cell volumes closely overlap when present as mixtures the counter would be unable to resolve them into distinct populations. In the present studies, a tissue culture line of Lewis rat tumor cells having a size distribution of 12.5–24 μ in diameter could be selectively counted when present in suspensions containing a high (100:1) multiplicity of lymphoid cells having a diameter of 6–15 μ. The same was true of L cells present (diameter = 14.0–24 μ) in mixtures with mouse lymph node cells (diameter = 6–15 μ).

The continuous ingestion of combinations of nystatin with either chlorotetracycline or zinc-bacitracin significantly (P< 0.01) reduced white cell counts. Hemoglobin and packed cell volume were consistently higher in all groups receiving antibiotics, but the differences were not statistically significant (P<0.05). When the antibiotics were fed singly, white cell counts, hemoglobin levels and the packed cell volume were affected, but to a lesser extent. The combinations of nystatin with chlorotetracycline or zinc-bacitracin, and zinc-bacitracin alone increased body weight gains significantly (P<0.05) in relation to the control or nystatin alone.

Angiotensin 11 given by intravenous infusion in a moderately large dose does not elevate either venous or arterial blood glucose levels within one hour in the conscious dog, nor does it produce glycosuria. This suggests that secondary release of catecholamines does not play a significant role in the physiological responses to angiotensin 11. The absence of glycosuria indicates that the renal tubular reabsorption of glucose was not affected by angiotensin 11 at this level of filtered load of glucose.

These findings provide evidence that immunity factors were active in the skin in the immunologic defense of rhesus monkeys experimentally infected by the intradermal route with scrub typhus rickettsiae, 6 days after exposure to the rickettsiae and several days before circulating antibodies had reached levels high enough to rid the blood of organisms. In 3 groups of monkeys, development of specific dermal lesions was completely suppressed at sites of the second, third, and fourth injections of scrub typhus rickettsiae when an interval of 6 days separated the first from subsequent injections, while in a single group of monkeys (Group 1) given 3 injections at a 3-day interval, lesions occurred at 2 injection sites. Although the role of circulating antibodies in the state of resistance to superinfection in the skin is unknown, the fact that presence of the immune state in the skin of a single monkey was established at the time this animal was circulating rickettsiae in the blood favors the suggestion that other immunity factors besides circulating antibody were at work in the dermal resistance of monkeys inoculated by the technique employed.

A relatively large number of compounds is known to cause activation or inhibition of myosin A-ATPase depending upon their respective concentrations in the incubation mixture. Some of these modifiers, such as ethylene diamine tetraacetic acid (EDTA), p-mercuribenzoate (PCMB), 2,4-dinitrophenol (DNP), are believed to interact with certain “specific groups” in or close to the active center of the enzyme. The mechanism of action of some other compounds such as urea, ethylene glycol and dioxane was explained mainly on the basis of their respective effects on the secondary or tertiary structure of the protein molecule. It was, therefore, thought that a study of the effects of some “specific” modifiers in the presence and absence of the specified solvents may throw more light on the importance of hydrogen and hydrophobic bonds in the enzymatic reactions of the myosin A.

Myosin A was prepared by standard methods(1). All ATP and ITP splitting experiments were carried out at 37°C in a 0.05 M tris buffer. The tecnique for ATPase determination has been published(2).

It may be seen from Fig. 1 that urea concentrations between 6 and 12% doubled the EDTA-activated ATPase activity of myosin A while that of Ca⁺⁺-ATPase was accelerated to a much smaller extent. Six per cent urea completely abolished the PCMB activation but diminished the DNP effect by only 20%. These results showed clearly that even small amounts of urea caused alterations of the active center of myosin A, so as to produce enzymatic effects which were decidedly different in the presence of various modifiers. The fact that urea enhanced only the EDTA-activated-ATPase would suggest that hydrogen bonding, as it existed on the enzyme, did not provide the best fit for ATP to be split in the presence of EDTA.

After 2 weeks of daily subcutaneous medication with chloroquine the order of increasing tissue concentrations in the English guinea pig was generally: plasma, muscle, heart, liver, spleen, eye, lung, and kidney. The level of ascorbic acid intake did not significantly affect the ocular concentration of the drug, nor did it significantly alter the tissue to plasma concentration ratios, except in the muscle. The apparent overall effect of ascorbic acid in significantly decreasing the tissue retention of this drug might prove to be a valuable property.

Pregnant Swiss mice were injected i.p. with 500 or 350 γ of 7,12-dimethylbenz(a)anthracene (DMBA) in tri-n-caprylin. Delivery occurred between 12 hours and 7 days after the injection. Five females, descendants from 2 pregnant mice injected with 350 γ of DMBA, were mated with their brothers. In both F1 and F2 untreated descendants a high incidence of tumors occurring at various sites was recorded. The most frequently occurring tumors were mammary carcinomas, granulosa cell tumors of the ovary and lung adenomas in the females, and lung adenomas, adenomas and carcinomas of the paraurethral gland in males. Many of the tumor-bearing animals bore more than one tumor. The transmission of the carcinogen via the mother's milk probably occurs in the mice of the F1 generation. The enhancement of an inherited low susceptibility to certain tumors seems to be the cause for the high incidence of tumors in the mice of the F2 generation.

Gel filtration proved to be a simple, effective method for separation of fluorescein-labeled antiglobulin for E. coli into 7S and 19S fractions. Both fractions were found to contribute considerable nonspecific staining, while specific staining was associated predominantly with the 7S globulin. The ratio of specific staining titer to nonspecific staining activity was 3-fold greater with a pool of fractions in which only 7S globulin was detected than with the unfractionated conjugate when the 2 preparations were tested at the same protein concentration.

1) Normal bovine adrenal medulla can effect the following reactions in vitro: a) Transformation of a straight-chain precursor (acetate) into steroid tetracyclic structures; b) Double bond shifting from Δ⁵ to Δ⁴ with concomitant oxidation at C₃; c) Introduction of -OH groups at specific sites of the pregnane nucleus and d) Conversion of C₂₁ to C₁₉ steroids. 2) It has consistently failed to metabolize cholesterol to corticosteroids. 3) It has shown in several steroid biosynthetic reactions a greater responsiveness to diphospho- and triphospho-pyridine nucleotides than the cortex.

Levine(4) has suggested that rats stimulated during infancy may be more reactive to, but also recover more rapidly from, stress as adults than non-stimulated rats. These rats have a higher output of corticosterone and steroid production is greater in the 15-minute period following stress. Similarly, Bell, Reisner, and Linn(1) reported that recovery from electroconvulsive shock (ECS) is more rapid in rats handled the first 5 days of life, as compared with rats that were either handled or unhandled at later periods. They defined recovery from ECS by blood glucose levels taken 24 hours after ECS and immediately following ether anesthesia. Blood glucose levels did not differ for subjects handled the first five postnatal days that did or did not receive ECS. Furthermore, differences were found for subjects not so handled. Since ether anesthesia is a stressor in and of itself, however, 2 alternative conclusions could be drawn. Recovery from ECS may have been complete in all subjects 24 hours after ECS. Consequently, the difference between the rats handled the first 5 days of life and the other groups showed these rats less reactive to the immediate stress of ether anesthesia. Or, conversely, possibly none of the rats subjected to ECS had recovered within 24 hours. The rats handled the first 5 days of life may have been more reactive to the etherization.

To test Levine's hypothesis, but unconfounded with ether anesthesia, the following experiment was conducted. One hundred and ninety-one Sprague-Dawley rats, 99 females and 92 males, were either handled or unhandled from days 2 through 5 of life, and either stressed or not stressed in adulthood. The handling procedure was removal of the litter from the mother. Each pup was then placed in a small glass dish for 3 minutes before being returned to the mother.

Isolated mitochondria from 2 tumor types indigenous to DBA/212 inbred strain (an epithelial cell, slower growing, and a spindle cell, faster growing) have relatively low initial O.D. (520 mμ) per mg protein and a very low rate of mitochondrial swelling. On the other hand, mitochondria from liver from the same strain of mice exhibit a higher initial O.D. per mg protein and have a high rate of swelling in vitro. “Aged” liver mitochondria have a much lower initial specific O.D. and also swell at a very low rate. Thus, it is proposed that the initial O.D. of isolated mitochondria and its rate of swelling under similar conditions of isolation, resuspension, and incubation is indicative of the inherent quality and integrity of the mitochondrial fraction. Certain conditions of pre-treatment and some specific additives increased mitochondrial swelling of both tumor types, indicating that the mitochondrial integrity of the tumors is at some intermediate state with respect to that of liver mitochondria.

The data presented indicate that glutamine remained stable when prepared in citrate or aqueous solution, stored at 4°C for at least 8 weeks or at room temperature for 3 to 4 weeks. Analyses of deproteinized plasma indicate that the glutamic acid concentrations were constant and stable for approximately 4 weeks. Plasma glutamine determinations were also quantitatively reproducible with time. These results would also suggest that with deproteinization of blood, the values obtained for glutamic acid are not due to glutamine breakdown but are true glutamic acid values.

Addendum: Since submitting this manuscript, it has been demonstrated that there is no significant increase in ammonia concentration in samples analyzed for one week from a plasma filtrate.

Thiazolidine-4-carboxylic acid (TZCA) was used to inhibit the incorporation of proline into rat liver ribosomes in a cell-free system. It was found that TZCA was incorporated into ribosomes via a pathway similar to that of proline. The coding polynucleotide for this incorporation was a homo-polymer of cytidine. t-RNA-TZCA-S³⁵ was also isolated, and this presented further evidence that TZCA-S³⁵ was incorporated into ribosomes following the formation of t-RNA-TZCA-S³⁵. Hence, these experiments show that TZCA may be used as a competitive inhibitor to the incorporation of proline into ribosomes in a cell-free system.

None of the fractions obtained from porcine spermatozoa resembled the classical histones or protamines in amino acid content when two different isolation procedures were utilized. A physical attack on the keratin by glass beads appeared to give inadequate penetration to release the other proteins of this cell. A chemical attack with per formic acid appeared quite adequate. Much of the protein in this cell is a basic keratin. The properties of such a protein would allow it to protect the DNA during its journey to the ovum.

Actinomycin D causes a fall in blood pressure of normotensive and renal hypertensive rats; the reduction of pressure is proportional to the dosage. Giving prednisolone did not restore the pressure but hormonal activity is not blocked since prednisolone protects against a lethal dose of actinomycin D given to adrenalectomized rats. Vigorous arterial pressor response to norepinephrine and methoxamine limits any peripheral arterial effect to tonic rather than phasic contraction.

The presence of lipoprotein lipase activity (LLA) in the adipose tissue of rats, rabbits and chickens is well established (1,2,3) but its presence in significant quantities in human adipose tissue has been questioned (4,5).

Angervall(4) found that lipoprotein lipase activity was considerably greater in chicken than in hen adipose tissue. Using a modification of the method described by Cherkes and Gordon(6), Chlouverakis(7) found that LLA in the adipose tissue of rats 4–5 weeks old was significantly greater than that of rats more than 5 months old. In interpreting this finding, however, it must be borne in mind that the protein/lipid ratio of young and old rat adipose tissue may differ(8).

This possibility was investigated by measuring the LLA in the adipose tissue of 2 groups of rats, one consisting of animals 4 to 6 weeks old and the other of much older animals (5 to 8 months), and expressing the results as LLA per unit of tissue wet weight and per unit of tissue protein. Other possible explanations for the apparent enzyme change associated with the ageing process, namely, a redistribution of the enzyme and its relationship to growth hormone, were also investigated.

Finally, in view of the conflicting reports regarding the enzyme activity in human adipose tissue, the LLA of subcutaneous fat was determined in material taken at biopsy.

Material and methods. Tissues. Male Wistar rats fed on a standard diet (Pillsbury's Thompson Diet Rat Cube, Birmingham, England), were used in all the experiments. “Young” rats were 4–6 weeks old and “old” rats were aged 5–8 months. Animals were killed by decapitation, adipose tissue was obtained from the epididymal fat body, muscle tissue from the diaphragm and the whole aorta down to its division to the iliac arteries.

Lysosomal DNase, RNase, β-glucuronidase and β-galactosidase activities in experimentally inflicted poultry breast bruises increased by the second day post contusion, reached a maximum between the third and fifth day and then declined toward normal as the bruises showed gross morphological healing. The magnitude of enzymatic response as a result of bruising was not the same for each enzyme, but all enzymes showed the same trends in activity. Activities were elevated to a greater extent in the center of the bruise than at the edge. Normal muscle from bruised chickens had activities similar to tissues excised from unbruised chickens. The effects of increasing the severity of muscular injury were to increase the maximum activity response and, also, the time required to reach it. Free, bound and total DNase, RNase and β-glucuronidase activities were determined as a function of age of bruise. All forms of the enzymes were found to increase during the healing process.

Experimentally inflicted poultry bruises were examined for ATPase, glycogen and lactic acid. ATPase activity decreased as a result of trauma and was dependent on age of bruise, severity of trauma and previous bruise history. Glycogen concentrations decreased within 12 hours of injury whereas lactic acid increased immediately following contusion. By 24 hours post trauma, both lactic acid and glycogen levels were considerably below normal levels and continued to be low throughout the healing process.

Mice that did not convulse after an initial exposure to oxygen at 3 or 4 atmospheres of pressure (absolute), convulsed in significant numbers after a second exposure. This residual effect of “hyperbaric oxygen” lasted as long as 6 days.

The mechanism of recovery from infection with the PR8 strain of influenza virus in nonimmune mice and in mice partially immunized with formalin-inactivated PR8 vaccine, was investigated. The results demonstrated that in the lungs of immunized mice limitation of virus growth is mediated primarily by specific serum NT antibody. ITF was not detected in the lungs of the immunized group challenged with a sublethal dose of virus but was demonstrated in the lungs of control mice from day 3 through day 5. It was not detected on day 7 when NT antibody appeared in the serum. Pulmonary virus growth, as indicated by tests for infectious, lethal and HA virus, was maximal from day 2 to day 5 at which time ITF content reached a peak. Thereafter, virus titers remained at a high level though declining when ITF was no longer demonstrated. The time of maximum lung consolidation was subsequent to these events. Partially immunized mice survived a lethal challenge of 10⁶ EID₅₀ and ITF was detected in the lung on day 5, whereas in the lungs of infected controls, higher ITF titers were present over a longer period but the mice did not survive. The implication of these findings is discussed.

The biochemistry of connective tissue in autologous skin grafts and intact skin of rats was studied. During the early period after surgery an increase in water and hexosamine content was observed in the grafts, together with a simultaneous decrease in concentration of hexuronic acid and hydroxyproline. The next period was characterized by a considerable increase in the content of acid mucopolysaccharides, and 54 and 103 days after grafting, the condition approached that of control skin. The alterations are considered part of the connective tissue response to injury.

Three new rhinoviruses isolated from young adults have been shown to be serologically distinct from each other and from 33 previously described rhinoviruses, 62 enteroviruses, and reovirus type 1. These new viruses are small RNA viruses (18-23 mμ) that are ether stable and acid labile, thereby fulfilling the criteria necessary for classification as belonging to the rhinovirus subgroup of the picornaviruses(1,2). They are nonpathogenic for mice. Rhinoviruses Baylor 1 and 2 appear to be group “H” rhinoviruses since all strains of these serotypes grow only in tissue culture cells of human origin (A-39 and WI-38) while Baylor 3 seems to be a group “M” rhinovirus since strains of this serotype could be passed in tissue culture cells of monkey kidney. Several passages of Baylor 3 strains in A-39 and WI-38 were necessary, however, before successful passage in monkey kidney could be made. Eight of 9 strains were isolated in A-39 cells, which have proved to be very useful in working with the rhinoviruses. Most previously described rhinoviruses have been found to be stable when heated in the presence of M MgCl₂, a property described for the enteroviruses(21). Baylor 2 and 3 serotypes are stabilized by M MgCl₂ or MgSO₄ but Baylor 1 is only partially stabilized by these salts.

Erythropoietic decompensation in renal failure has been attributed to diminished production of erythropoietin(1,2) or decreased marrow sensitivity(3,4) to this substance. The relative significance of diminished stimulation or marrow inhibition remains unknown. In the present experiments erythropoiesis and responsiveness to erythropoietic stimulation were assessed in rats made acutely uremic by bilateral nephrectomy. In addition, the effect of uremic plasma on in vitro reticulocyte iron incorporation was studied. The results suggest that red cell production diminished in part because sensitivity to erythropoietin was decreased. In vitro incorporation of radioiron by reticulocytes was not depressed by the uremic milieu.

Materials and methods. Female Sprague-Dawley rats weighing 200–300 g were maintained on a regular laboratory animal diet† and provided water ad libitum. Erythropoiesis was assessed in normal rats and in nephrectomized rats 48 or 72 hours following removal of the kidneys. Similar assessments were undertaken in normal rats and nephrectomized rats stimulated by injection of exogenous erythropoietin.

The stimulated nephrectomized rats were given injections of active extract of anemic rabbit plasma(5) one, 18, and 24 hours following nephrectomy. Non-operated controls were stimulated in an identical manner and measurements of erythropoiesis were made in both groups at 72 hours. Erythropoiesis was assessed by: determination of microhematocrits, enumeration of reticulocytes(6) and measurement of erythrocyte incorporation of radioiron 24 hours after intravenous injection of 1 μc Fe⁵⁹/1 μg Fe⁵⁶ citrate(5). Radioiron partition in the spleen, liver and bone marrow(7) was also determined. Urea nitrogen content was determined on pooled plasma samples from each group(8).

Additional experiments tested the effect of uremic plasma on in vitro iron incorporation by reticulocytes. Reticulocytosis was produced by serial bleedings each approximating 20% of the rats’ blood volume. One week following the initial bleeding, the rats were exsanguinated.

Bovine thrombokinase, incompletely purified, was subjected to gel filtration on Sephadex G-200. Almost all of the protein emerged from the column in the position corresponding to the third wave of serum proteins. The thrombokinase subfractions had the capacity to activate prothrombin in the presence of oxalate, to cause prothrombin activation in a system containing calcium, phospholipid and accelerator (factor V), and to activate chymotrypsinogen. No separation of these activities was evident. This makes it desirable to enquire further whether these activities, as well as the TAMe esterase and the power to correct the Stuart defect, are all properties of the thrombokinase molecule. Accumulating evidence continues to favor the view that thrombokinase can, under proper circumstances, activate prothrombin without the help of presently known forms of accelerator (factor V).

The pathway of NAD biosynthesis in Mycobacteria was studied with cell-free extracts of M. tuberculosis var. bovis strain BCG Tice. The organism converted niacin to NAD with NaMN and NaAD as intermediates. PRPP, ATP, and MgCl₂ were shown to be requisite for NaMN formation while glutamine or asparagine were shown to be necessary for conversion of NaAD to NAD. The pathway was further elucidated by the demonstration that NaMN was itself utilized directly for coenzyme synthesis without prior decomposition to niacin.

After receiving interscapular injections of 2,4-dinitrophenol, 10 mg/kg daily for 4 days, rabbits were killed on the fifth day. The balance data revealed no significant changes except an increase in body weight. The relative specific activity of Mg²⁸, determined 4 hours after intravenous injection of Mg²⁸, was significantly increased in the kidney, heart, stomach, liver, lung, bone marrow, skin, brain, and bone cortex. The increased turnover of magnesium in these tissues is attributed to the increased rate of oxidation caused by 2,4-dinitrophenol.

The use of the highly sensitive bactericidal assay has allowed the detection of natural antibody in human parotid fluid to Salmonella typhosa and Shigella dysenteriae. This antibody activity parallels closely the bactericidal activity found in serum. Bactericidal activity in parotid fluid was localized by sucrose density gradient in fractions within the sedimentation range of 7–11S. Other antibody-like activities in parotid fluid were demonstrated by evaluating its protective effect on dextran-enhanced Salmonella infection in mice and phagocytic-promoting ability as measured by the clearance of C¹⁴-labeled bacteria. The nature and possible role of such antibody in parotid fluid is discussed.

It was demonstrated that parenteral administration of L-Triiodothyronine (L-T3) initially increased and then decreased utilization of glucose by the RBC of rabbits(1). Because of this fact, we became interested in studying the effects of clinically large doses of this compound on utilization of glucose by the human erythrocytes. Certainly, if a peripheral cellular effect could be demonstrated, then there would be a possibility of establishing a clinically useful tool for reflecting total body metabolism and perhaps evaluating thyroid function. The present investigation was therefore designed to study in humans: 1) normal fluctuations in rate of glucose utilization by RBC, and 2) effect of L-T3 on this rate.

Methods and material. Fasting venous blood was obtained from healthy volunteer men and women to insure satisfactory range in age and sex distribution. These individuals were clinically free of any disease and not taking medication. The laboratory procedure followed has been described(1). Blood samples were collected with siliconized equipment, and heparin was used as the anticoagulant. In vitro tests were conducted by centrifuging the samples for 20 minutes at approximately 2700 RPM (1000 g's) in an International Clinical centrifuge. The buffy coats and upper red cell layers were carefully aspirated and discarded and the RBC were then resuspended in the subject's own plasma. The final hematocrit was adjusted to approximately 50%. Preparation of RBC suspensions were conducted at room temperature. White blood counts were done on the original sample of blood and on the final suspension of RBC to estimate efficiency of removal of WBC, because of their relatively high rate of glucose metabolism(2,3,4). Glucose determinations were made in duplicate using the Somogyi-Nelson procedure(5). Within one hour after venipuncture, samples in glass-stoppered centrifuge tubes were incubated at 36–37°C in a water bath and equilibrated in air atmosphere since previous experiments did not reveal a significant difference in glucose metabolism under aerobic and anaerobic conditions.

Thymectomy at 3 days of age in several inbred strains of mice and in an F₁ hybrid resulted in a strikingly increased frequency of neoplasms following infection with polyoma virus. Age susceptibility was extended to at least 30 days of age in highly resistant C57BL mice. The usual stigmata associated with thymectomy at birth were not found in the 3-day thymectomized mice. Nonetheless the methods used to restore immunologically deficient thymectomized neonates were also effective in restoring the capacity to resist polyoma virus tumor induction: adult syngeneic spleen cells, thymus tissue in Millipore diffusion chambers and syngeneic thymus grafts. Growth curves of polyoma virus in kidney, salivary glands and liver were quite similar in thymectomized and intact litter mates. Hemagglutination-inhibition antibodies determined periodically up to 30 days after infection were also similar in both groups. These results are discussed in terms of a concept involving virus-specific “tumor” antigens and the immunologic status of the animal.

Small doses of nicotinic acid were injected i.v. into alloxan diabetic dogs, causing an initial, rapid, significant decrease of plasma FFA followed by a rebound increase over control values. Blood sugar and total cholesterol were not affected.

Significant positive associations were found between urinary taurine excretion and 2 measures of adaptive behavior, cottage placement and I.Q. scores. The correlation ratio between cottage placement and taurine excretion was E_yx = .41. I.Q. score regressed on taurine excretion yielded a coefficient of .32. Both associations are significant at the 5% level.

Erythrocytes of 20 dogs were studied before and after in vivo exposure to oxygen under high pressure (OHP). No evidence of in vivo hemolysis was noted but erythrocytes from dogs exposed to OHP demonstrated increased osmotic fragility and decreased acetylcholinesterase activity. Additional evidence indicated the in vivo formation of lipid peroxides in erythrocytes. No change in glucose-6-phosphate dehydrogenase activity, reduced glutathione content, or met-hemoglobin content occurred, and no Heinz bodies were formed during OHP. Thus, inadequacy of the pentose-phosphate shunt was probably not responsible for cell damage. It is suggested that altered permeability of erythrocytes resulted directly from peroxidation of lipids or indirectly from inhibition of erythrocyte acetylcholinesterase or a combination of both effects.

Previous studies from this laboratory(1) showed that intratracheal inoculation of rhesus monkeys with the PR8 strain of influenza virus resulted in mild illness in 2 of 4 monkeys; after intranasal inoculation, no clinical signs of illness were observed. Results of studies by others (2–5) have varied with the influenza virus strain and monkey species employed. In all, virus was administered intratracheally or intranasally, and in general, clinical evidence of disease was minimal or absent.

The development of quantitative procedures for exposure of experimental animals to aerosols of infective organisms(6) suggested reinvestigation of the response of monkeys following challenge with influenza virus by these methods. The present report describes the clinical, hematologic and serologic response of rhesus and cynomolgus monkeys after aerosol exposure to the PR8 strain of influenza virus.

Materials and methods. Challenge of young adult monkeys, Macaca mulatta and M. irus, was conducted in a Model 3 Henderson apparatus(6) by previously described methods (7,8). The aerosol generator was charged with mouse lung nitrate containing about 1.0 × 10⁸ mouse intranasal LD50 per ml of the PR8 strain of influenza A virus. Monkey doses were calculated from studies of concurrently exposed 14–16 g white mice. Intratracheal inoculation of allantoic fluids(9) containing strains A/PR8/34, Swine/1976/31, A2/Japan/305/57, and B/Great Lakes/1739/54 was performed as described previously(1).

Physical examinations, hematologic and serologic studies were carried out for 2 weeks prior to challenge. After challenge, monkeys were examined twice daily. Femoral vein blood was used for blood counts and C-reactive protein (CRP) tests daily or every other day, and weekly for serologic studies.

Cell lines derived from human aorta have proved useful for the isolation and propagation of rhinoviruses. In the A-39 cell line, which has been used most often, viruses reach infectivity titers of up to 10^5.5 TCD₅₀ per ml and produce readily discernible cytopathic effects. The cell line is easily grown and may be maintained for long periods. It proved to be more sensitive to the rhinovirus serotypes prevalent during the 1963–64 winter than the presently employed WI-38 or human embryonic kidney cells. During the fall of 1964, the prevalent rhinoviruses were selectively isolated on human kidney cells, but during the current winter season aorta and WI-38 cell lines were again more sensitive to the new rhinoviruses in the community.

A series of mice was injected subcutaneously with lysolecithin and the tissues examined at measured intervals. Within 10 minutes after injection, striking edema with necrosis of fat tissue was evident at the injection site. Subsequent changes included infiltration with neutrophil leukocytes and histiocytes and hyalinization and necrosis of muscle cells. Despite the marked edema and contrary to previous reports, vascular damage was not demonstrated by light microscopy. The production of lysolecithin could account for much of the local necrosis resulting from snakebite.

Both cerebrosides and soy sterols were very effective in reducing serum cholesterol levels, and thoracic aorta and coronary atherosclerosis in chicks fed an atherogenic diet. This effect of cerebrosides was directly proportional to the dose administered. Soy sterols were without effect on endogenously induced hypercholesterolemia produced by estrogens.

Immune anti-B antibody was detected by absorption of sera with certain rabbit red cells (B^R), and agglutination and hemolysis of the absorbed serum with human group B red cells. The antibody (anti-B_i) activity was found only in IgG fraction. The method might be useful for detection of immune anti-B antibody in human sera especially in cases of hemolytic disease of the newborn due to group B incompatibility.

An anti-inflammatory granuloma assay in the adrenalectomized rat has been employed to evaluate the relative potency of various nonsteroidal compounds. Statistically significant responses have been observed, but dose-related responses were not obtained. Graphic estimations of the range of relative potencies using cortisol acetate as the standard with an assigned potency of 100 follows: chloropheniramine maleate, 28–55; dipyrone, 3–8; phenylbutazone, 2–16; aminopyrine, 2–14; cinchophen, 2–18; and antipyrine, 1–5.

A procedure is described for the isolation and characterization of the fatty acids of lecithin (plus lysolecithin) and sphingomyelin from blood serum. This procedure was employed for analysis of these fatty acids in 10 normal adult humans. The results indicate that serum lecithin is comprised of an approximately equal proportion of saturated and unsaturated fatty acids while sphingomyelin contains a series of saturated and monounsaturated fatty acids ranging from 14 to 25 carbon atoms. The major fatty acids of lecithin were 16:0, 18:0, 18:1 and 18:2 while the major sphingomyelin acids were 16:0, 18:0, 22:0, 24:1 and 24:0. There were no apparent age-dependent changes in the fatty acid composition of these lipids (16–56 years). The fatty acids of sphingomyelin appeared to vary in composition from subject to subject more than those of lecithin.

Experiments have been undertaken to extend the observation of Rieser and Rieser that chymotrypsin and trypsin have insulin-like activity in vitro(1) and that insulin has some protease properties(2). Concentrations of trypsin and chymotrypsin equal to molar concentrations of insulin which cause a marked hypoglycemia in vivo were administered to rats and dogs. Neither trypsin nor chymotrypsin had any insulin-like activity in vivo. These enzymes were also tested on the in vitro glucose uptake of rat hemidiaphragms and epididymal fat pads. Only trypsin had a marginal effect on glucose uptake, an effect that was much less than the effect of an equimolar concentration of insulin.

Six-week-old C3H mice injected neonatally with Gross passage A leukemia virus were found to be unable to reject skin grafts across a weak histocompatibility barrier. The similarity of the defects in the immune mechanisms of these mice to those of the neonatally thymectomized mice suggests that the establishment of the oncogenic agent in the neonatal thymus results in marked functional impairment long before histologic changes are apparent.

Inulin and PAH concentrations and osmolalities were determined in samples of tubular fluid collected from surface convolutions of rat kidneys during urea diuresis. F/P inulin ratios averaged 1.6 for the proximal tubule, 2.9 for the distal convolution and 21.7 for the ureteral urine, all significantly lower than in nondiuretic rats. Net PAH secretion appeared to be confined to the proximal tubule and could not be demonstrated in other parts of the nephron.

Currently accepted theories on the control of bleeding in oozing blood postulate two main but quite distinct mechanisms: formation of blood clots and agglutination of platelets to form a plug in this region. In both instances a mechanical stopper is visualized and hemostasis is interpreted as a phenomenon entirely dependent on blood components, particularly the disintegrative processes concerned with these.

Several observations have been presented (1,2,3,4) which were extremely difficult to resolve in terms of the classical theories noted above. It was then suggested that hemostasis is a function of active metabolic events and that the local area of injury, rather than blood itself, plays the most important role in the control of bleeding.

Methods. The results presented here were carried out by a method developed in our laboratory. A small area of keratinized epidermis in a rat tail is removed with a razor blade and the ensuing bleeding stops in 1 to 2 minutes. When mechanical trauma (such as strong scouring with gauze) is subsequently inflicted on such scarified skin and the tail immersed, in a vertical position, in different fluids at 37°C, the bleeding in each vessel (arteriole or venule) can be observed through a dissecting microscope (30 to 50 × magnification) until hemorrhage completely ceases. Table I shows that this method is quite consistent, the range of bleeding time (B.T.) varying between 40 to 90 seconds (Table I).

Results. Direct visual observation. Bleeding from arterioles never stopped abruptly. There was always a progressive decrease in the diameter of the falling column of blood until a very thin stream was observed just before the end of bleeding.

Repeated mechanical stimulation. When mechanical trauma was applied at about 10-minute intervals, B.T. remained fairly constant for a period of about 2 hours (average for 12 determinations — 56″ with a range of 20″–93″). When, however, the trauma was applied as soon as the bleeding stopped, then, after from 5–10 such stimulations, the scarified skin failed to bleed even though subjected to the most violent mechanical stimulus.

It appears that the conflicting reports in the literature regarding the effects of adrenalectomy on the concentration of water and electrolytes in the kidney may be due to different levels of circulating ADH in the animal at the time of experiment, or to differences in the protocols of the several sets of experiments.

Catecholamine levels were determined in tissues obtained from dogs subjected to prolonged oligemic hypotension. The lung and liver were found to have retained their normal complement of catecholamines while the cerebral hemisphere, spleen and heart were depleted. In the brain the depletion appeared to be a terminal phenomenon, possibly associated with the respiratory difficulties experienced by the animal at that time. In the spleen the depletion seemed to take place progressively throughout the experimental period. An attempt is made to reconcile these data with known metabolic and functional parameters of the organs studied.

Infusion of Ach into one renal artery of the dog induced unilateral increase in calcium and phosphate excretion and increased GFR, ERPF and excretion of sodium, potassium, chloride and water. Products of Ach hydrolysis, choline and acetate, were inactive. Atropine blocked the renal responses to Ach but exerted no renal actions in the absence of exogenous Ach. Several anticholinesterases failed to alter renal hemodynamic or excretory functions. The excretory changes produced by Ach were not explicable on the basis of changes in GFR alone and indicate that Ach exerted a direct renal tubular action. The data constitute further evidence that cholinergic mechanisms may be regulators of cellular cation transport systems.

A comparative study has been made of 4 methods, namely, disc, well, plate and turbidimetric methods for testing polymyxin-sensitivity of the choleragenic vibrios. The plate method using 15 μg/ml of polymyxin B in agar medium is recommended as the method of choice for routine screening tests for differentiating V. cholerae and V. el tor strains. By this method all the 502 strains of classical cholera vibrios tested were found sensitive and 99.5% of the 544 strains of El Tor vibrios completely or partially resistant to polymyxin B. With the turbidimetric method, resting cells of both V. cholerae and V. el tor showed evidence of progressive lysis in the presence of polymyxin. But when vibrios were tested in their growing phase V. cholerae strains appeared sensitive to polymyxin while the V. el tor cultures proved resistant. El Tor strains, however, showed an initial phase of growth inhibition before their normal growth pattern was restored.

Hamster cells transformed by papovavirus SV40 in vitro and in vivo possess new surface antigens that can be detected by the indirect immunofluorescent technic. Antibody against the surface antigens of the SV40-transformed cells fail to react with normal cells from various species including the hamster, with the “spontaneously” oncogenic hamster BHK21 cells, or with hamster cells transformed by adenovirus type 12. Inoculation of hamsters with cells not transformed by SV40 did not elicit synthesis of an antibody capable of reacting with the surface antigens of the cells transformed by the papovavirus.

A single subcutaneous injection of CdCl₂ (0.03 mmole/kg) to mature male C. D. mice consistently produced vascular damage to the testis characterized by marked edema, capillary hemorrhage and thrombosis with resulting interstitial tissue and tubular necrosis. Previous treatment with testosterone propionate did not alter this response. A treatment period with estradiol benzoate, which resulted in tubular regression, protected the testis against vascular injury from cadmium. This protection was reversible since following cessation of estradiol benzoate treatment and disappearance of tubular atrophy, the testes were again susceptible to cadmium induced vascular damage. The induction of tubular regression was not essential for this vascular protection by estrogen since stilbestrol, which did not produce tubular regression in the doses used, also protected the testis against vascular injury caused by cadmium.

Attempts were made to demonstrate the presence of thyronine within thyroid tissue slices as well as its formation using as accepted precursor UL-C¹⁴-tyrosine. Not only was thyronine not isolated but no evidence was found for the incorporation of tyrosine into any of the thyronine iodinated analogs.

The data presented here indicate clearly that the previously reported antigenic relationship between ECHO types 29 and 32 was the result of working with a mixture of the viruses in question. No antigenic relationship between these types was detected by tube neutralization, plaque-reduction, or hemagglutination-inhibition tests when “purified” reagents were employed.