Experimental Biology and Medicine

Pentobarbital inhibits the incorporation of ³²P and sodium formate-¹⁴C into RNA of Ehrlich ascites tumor cells in vivo and in vitro. In addition, the RNA specific activity of Ehrlich ascites cells prelabeled with uridine-³H, remains constant in untreated cells and in cells treated with pentobarbital, but decreases in cells treated with actinomycin D or with actinomycin D plus pentobarbital.

A conjugate subjected to diethyl-aminoethyl-cellulose chromatography and gradient elution to eliminate both underconjugated and overconjugated antibody molecules has been used to localize specifically Chikungunya, Mayaro, and Semliki Forest viruses in HeLa cells. Immunofluorescence was present in the cytoplasm only and was diffuse in nature; nonspecific staining was negligible. The three viruses, closely related members of arbovirus group A, were readily distinguishable by the indirect fluorescent antibody (FA) technique. The FA titers of homologous systems were reproducible and uniformly higher than the FA titers obtained in heterologous systems.

Rhesus monkey pituitaries were grown in tissue culture; and growth hormone and prolactin secretion were measured by radioimmunoassay and bioassay, respectively. As culture time progressed the secretion of growth hormone and prolactin declined but the ratio of prolactin to growth hormone increased. These results support the concept that simian growth hormone and prolactin are separate hormones.

The translocation and fate of both ³²P-labeled and unlabeled Salmonella enteritidis in mice fed, by gavage, 1 ml containing 10⁸ cells of either an 18-hr or 36-hr-old culture was determined. Onset and duration of infection and the presence of viable cells of test culture in organs were confirmed by bacterial and radioisotope analyses. Mice fed 10^{8 32}P-18-hr culture had low specific activity on 2nd hr PF (liver, 72; spleen, 61; and cecum, 1480 counts min^-1 mg^-1 of tissue) increasing to 147, 103, and 2110, respectively, on 6th hr. Mice infected with ³²P-36-hr culture showed high specific activity (counts min^-1 mg^-1 of tissue) on 2nd hr postfeeding; liver, 328; spleen, 227; and cecum, 11,170 followed by a rapid decrease to 234, 216, and 4820 counts min^-1 mg^-1 of tissue on 6th hr, respectively. This radioisotope study indicated that the 18-hr-old culture was more invasive than the 36-hr culture. Ultrathin sections of duodenum, obtained from infected mice, and stained with fluorescent antibodies revealed the presence of high fluorescent bacterial cells having a retention time of 3 min similar to that of pure S. enteritidis cells. Histopathologically these sections showed regressive changes in surface epithelium of intestinal mucosa of mice fed 18-hr culture and coagulation necrosis was common at tip of the villi. The pathological data showed that 18-hr culture produced a more severe enteritis compared to 36-hr-old culture.

Acetyl CoA carboxylase activity was negligible in embryonic chicken liver, but increased markedly after hatching to adult levels in 2 weeks. Very high pyruvate carboxylase activity observed in embryonic livers progressively decreased, reached minimum values 10–14 days posthatching, and thereafter increased to adult levels. Propionyl CoA carboxylase, on the other hand, showed no such adaptive changes throughout the period studied.

Listeria infection has been shown to increase resistance of mice to pneumococcal challenge. This protection does not appear to be related to presence of circulating antibody. Enhancement of macrophage function is proposed as an explanation for the observed phenomenon.

The adjuvant arthritis test was used as a model to measure the effect of Aldactone on the ulcerogenic and antiinflammatory activities of Indocin. It was demonstrated that Aldactone can abolish the ulcerogenic activity of Indocin while causing only a limited depression of the anti-inflammatory activity. Aldactone, therefore, may be useful in the clinic in reducing the gastrointestinal irritation caused by Indocin treatment.

Gastric lipase has been demonstrated in uncontaminated gastric juice (3, 4, 6) and within the gastric mucosa (1, 7) of man and various laboratory animals. In the present study, the effect of stimulation with histamine and Urecholine on secretion of lipase by canine Heidenhain pouches was determined.

Materials and Methods. Collection of gastric juice. Two trained female mongrel dogs, weighing 19 and 21 kg, respectively, were equipped with chronic Heidenhain pouches. The pouches remained free of infection or exudation along the metal cannula. After collection of unstimulated gastric juice for 2 hr, saline with histamine (124 μg/kg/hr) or Urecholine (88 μg/kg/hr) was infused intravenously for 3 hr at a constant rate of 11.5 ml/hr. With each drug, three experiments per dog were performed. In two experiments, stimulated juice was pooled and collected at 30-min intervals (see experiments with 30-min samples). In one experiment, all collections of the second and third hour of stimulation were pooled (see experiments with pooled gastric juice). Gastric juice was collected in cooled containers, refrigerated immediately after collection, and incubated for determination of enzyme activity within 4 hr after collection.

Determination of lipolysis. The rate of hydrolysis of trioctanoin in vitro was used as an estimate of the concentration of lipase in gastric juice. Octanoic acid was measured after incubation of 1 ml of gastric juice with 20 μl of trioctanoin.

The pH of gastric juice was adjusted with 0.2 M citrate buffer (pH 2, 3, 4, or 5), phosphate buffer (pH 5, 6, 7, or 8), tris buffer (pH 8 or 9), or by titration with 0.2 M NaOH or HCl. To this mixture, trioctanoin was added (20 μ1/1 ml of gastric juice). Incubations were performed for 60 min in a shaking waterbath at a temperature of 37°. Due to the rapid shaking (150 shakes/min) the fat was kept in milky suspension.

Reserpine pretreatment (1 mg/kg) given either 4 or 24 hr prior to the experiment did not affect the transmembrane exchange of Na and K in cat papillary muscles. In addition, changes occurring in Na, K, and H₂O content of the muscle were not influenced by reserpine. Since it is known that quinidine causes changes in Na and K exchange and in the total Na and K content of cardiac muscle, it is unlikely that the action of reserpine to antagonize digitalis-induced ventricular arrhythmias is related to a quinidine-like effect on cardiac muscle.

The overall rate of incorporation of tritiated uridine into RNA in NB cells rapidly decreased after H-1 virus infection. This decrease in rate of RNA synthesis was apparently due to a decrease in number of cells synthesizing RNA. The 28S ribosomal RNA was selectively inhibited while the low molecular weight 4S RNA was selectively stimulated.

Spontaneous ischemia of the kidney has been reported in dogs subsequent to anesthesia and/or surgical trauma. This phenomenon can be characterized as having a differential effect on intrarenal aerobic metabolism. Washed homogenates of cortical and medullary tissue were prepared from nonischemic and ischemic kidneys. The rates of O₂ consumption, α-KG utilization, and P ₁ disappearance were the same in cortical homogenates of ischemic and nonischemic kidneys. Each of these rates was significantly lower in medullary homogenates of ischemic kidneys than in nonischemic kidneys. Cortical homogenates that were stressed secondarily by acute aging had rates of O₂ consumption, α-KG utilization, and P ₁ disappearance that were below that of fresh homogenates. The changes in metabolism cannot be explained by changes that were observed in the activities of MDH and ICDH.

Concentrated hemagglutinin of psittacosis agent was reactive in gel diffusion with sera collected from cases of human chlamydial infections and animal immune serum. The reactions obtained with human sera appeared to be associated with chlamydial group antigen. A second antigen was detected in the hemagglutinin preparations when they were diffused against rabbit antipsittacosis serum.

Histologically normal isolated, short-circuited rabbit ileum absorbed both sodium and chloride ions. Structurally damaged mucosa did not absorb either ion. Glucose mediated short-circuit current effect was present in normal but was much reduced in abnormal tissues. These findings in tissue with altered structure were compared to tissue exposed to cholera toxin, where no net sodium absorption occurs yet net chloride movement from serosal-to-mucosal surfaces occur. In contrast to the pathological tissues the absent net sodium absorption in cholera is reversible with the addition of glucose to the mucosal medium.

The effects of atropine were evaluated on ionic movement across fundic and antral mucosa. 0.16 N HCl solutions were instilled into vagally denervated fundic and antral pouches. Atropine (0.05 mg/kg) increased the mean net loss of H⁺ ions in both pouches, but to a slightly greater extent in the fundus (86%) than in the antrum (66%). Although the mechanism of action is speculative, it is suggested that the diminished acid output in gastric secretion following atropine may be due to secretory inhibition, and to a lesser extent, a transmucosal loss of hydrogen ions.

The permeability of proximal convolutions and loops of Henle to ¹⁴C-urea has been studied using the microperfusion technique in the intact rat kidney. The permeability coefficient of both structures is about the same, 12.5 × 10^-4 and 10.4 × 10^-4 mm/sec, respectively, and these values are very close to those obtained previously by other authors.

In rats adapted first to hypoxia simulating 7000-m altitude, further exposures to low oxygen tensions stimulated collagen synthesis only in the granuloma tissue and had no effect on the degradation of collagen. The polymerization of soluble forms into less soluble collagen was decreased. In the liver and lung, collagen synthesis did not change. In the heart and small intestine, collagen synthesis was significantly decreased. The formation of noncollagenous proteins was significantly inhibited in all tissues studied. No effect of hypoxia on hydroxylations of collagenous proline was observed.

Young Sprague-Dawley rats force-fed a tryptophan-devoid diet for 1 day show enhanced hepatic protein synthesis and decreased gastrocnemius muscle protein synthesis in comparison with animals force-fed a complete diet. These changes are similar to those observed previously in rats force-fed diets devoid of other single essential amino acids for 1 to 7 days.

It has been found that the addition of leucogenenol to a medium in which lymphoblastoid or leukemic cells of mice are growing increases the respiratory quotient and the rate of replication of the cells. It would appear therefore that leucogenenol's known activity in the animal is due to a direct action of leucogenenol on the blood cells.

The fact that leucogenenol is normally present in liver tissue suggests that leucogenenol plays a role in the normal growth and regulation of blood cells in the body.

Our data demonstrate that the administration of borane is followed by extensive changes in tissue amino acid levels. These changes are probably due to the extensive inhibition of aminotransferase and other pyridoxal-dependent enzymes. One possible mechanism for such an effect is the chemical reduction, and consequent inactivation, of the active holoenzyme by borane.

Adrenergic activity of the hypothalamus prior to and subsequent to ovulation was evaluated in rats. Turnover of hypothalamic norepinephrine was measured by following the decline of endogenous NE levels after synthesis blockade with α-methyl-p-tyrosine methylester. Proestrous rats showed both a greater concentration and depletion of NE than estrous rats. Coincidentally, in proestrous rats an increased synthesis of hypothalamic NE as measured from the conversion of ³H-tyrosine to ³H-NE was observed. These results suggest that an increased NE activity takes place in the rat hypothalamus before ovulation.

Rat liver chromatin was fractionated by differential centrifugation of nuclear sonicates in a 0.25–2.5 M linear sucrose gradient. Diffuse, transitional, and dense chromatin fractions were resolved which contained 22 ± 4, 10 ± 4, and 68 ± 5% of the total DNA, respectively. The diffuse chromatin incorporated RNA precursors in vivo 10–15 times more actively, and contained 2–3 times more RNA, phospholipid and nonhistone protein per unit DNA than dense chromatin. Mg²⁺ and Ca²⁺ (0.001-0.003 M) caused the diffuse chromatin to sediment with the dense chromatin apparently due to aggregation. Na⁺ and K⁺ (0.05 M) rendered the dense inactive chromatin more buoyant, possibly by dispersing it. During liver regeneration (12-hr posthepatectomy), the diffuse chromatin content increased 50% and incorporation of ¹⁴C-orotate into its RNA trebled. Actinomycin D (a single dose of 1 mg/kg administered 16 hr before sacrifice) reduced the size of the diffuse chromatin fraction by 65% and the specific activity of its RNA by 70%.

The number and content of dilated splenic hilar lymph vessels were examined in patients with and without congestion of the spleen. Sections from 10 patients without congestion showed no dilated lymph vessels. Sections from 7 patients with congestion all showed an increased number of dilated lymph vessels many of which contained red blood cells. One other patient who died after portal decompression demonstrated normal lymph vessels.

The results indicate that splenic hilar lymphatics enlarge as a result of splenic congestion and reflect an increase in splenic lymph formation. Absence of red blood cells in splenic lymph vessels under normal circumstances and their appearance in congested states supports the view that the intermediate circulation of the spleen is normally closed and that in congested states may be open.

Serum prolactin and LH values were relatively low on the morning of proestrus, but increased remarkably on the late afternoon of proestrus. Peak values for both hormones were reached between 5:30-7:30 p.m., although prolactin began to rise earlier and declined later than LH. Placement of rats under ether anesthesia for about 0.5 min prior to withdrawing blood for radioimmunoassay did not change normal serum prolactin and LH trends, and prolactin values were the same as in unanesthetized rats killed by guillotine. Prolonged pentobarbital anesthesia completely blocked the late afternoon rise in serum prolactin and LH, but prolactin values showed a significant increase 10-30 min after injecting the drug.

Following duodenal dosing, ⁶⁵Zn was rapidly accumulated by several calf tissues, with a considerable amount in the liver and other tissues within 1 hr. With adequate dietary zinc, liver contained a substantial quantity of labile zinc which was greatly depleted in calves fed a zinc-deficient diet for 2 weeks. Other soft tissues had a very limited amount of labile zinc. Zinc turnover rate was much slower in muscle than in the softer tissues, and was not greatly affected by dietary zinc level. Transfer of zinc from the intestinal mucosa to the blood appeared to be the rate-limiting step in zinc absorption. This step was accelerated by feeding a zinc-deficient diet for 2 weeks. However, ⁶⁵Zn uptake by the mucosa from the intestinal contents was vastly increased by the zinc-deficient diet.

The unlimited serial propagation of a human colonic tumor, GW-77, in unconditioned, adult golden hamsters raises the question of its still possessing “human” properties. Both the direct fluorescent antibody test and its LDH isoenzyme-mobility pattern reveal the human species-specific character of GW-77. The retainment of its original species-identity is consistent with its relatively less malignant, only locally expansive, growth-behavior in various sites of the hamster.

Two lambda proteins, one a γM and the other a γG3, were isolated from the same human myeloma serum and were shown to share individual antigenic (idiotypic) specificity when tested with several antisera prepared against the intact proteins and pepsin digested fragments. These shared determinants were localized to the heavy chains and the combinational structure of the heavy plus light chains. Shared individual determinants of the light chains were also demonstrated utilizing antisera prepared against the isolated light chains. These results indicate that the light chains and the variable regions of the heavy chains of the two proteins are extremely similar. The peptide map and mobility differences in the light chains indicate that they are not identical.

The small intestines of control and bile fistula rats were perfused for 4 hr with a micellar solution of bile salt, glyceryl monooleate, and ¹⁴C-labeled oleic acid followed by rapid washout and steady perfusion with saline for an additional 4 hr. Measurements on hourly lymph collections from the thoracic duct for 8 hr, pooled ileal effluents and intestinal wall showed that (i) in both groups endogenous lymph lipid increased in proportion to the total lipid, (ii) in the control group lymph lipid increased after 3–6 hr to peak concentrations of from 15.1 to 38.8 mg/ml or 2.7-7.0 times that of the micellar solution, (iii) in both groups similar amounts of the micellar lipid were absorbed but the bile fistula group retained a significantly higher proportion in the wall after 8 hr and transported a significantly lower proportion in the lymph. The results support the micellar concept of lipid absorption by showing the production of chylomicrons from micelles in control animals but indicate that chylomicron production or transport is abnormal in bile fistula animals despite the presence of bile salts in the lumen above the critical micellar concentration.

Single pituitary grafts from donors of the same sex maintained some growth and led to slight maintenance of testes in male and uteri in female hypophysectomized rats. There was slight maintenance of adrenal weight in both sexes. Injection of crude sheep stalk-median eminence (SME) extracts resulted in a further significant increase in testes and ventral prostate weights in hypophysectomized, grafted males and in uterine and ovarian weights in grafted females on comparison to the weights of these organs in grafted animals injected with cerebral cortical extract. Adrenal weight was increased in rats of both sexes by SME extract. The results provide evidence that chronic injection of hypothalamic extract can increase the weight of pituitary target organs in both male and female rats presumably via stimulation of both release and synthesis of pituitary hormones.

Histones from calf thymus and liver were found to precipitate ¹³¹I-SFMC and to neutralize anticlotting activity of heparin nearly as efficiently as protamine. Lysozyme showed both activities but had to be used in tenfold higher concentrations to induce similar effects. Cytochrome C neutralized heparin but did not precipitate SFMC. Heparin, chrondroitin sulfate, and bovine aorta extracts inhibited precipitation of SFMC induced by protamine and histones.

Comparisons were made of increases in brain, body, and other organ weights and of organ/body ratios of 18 infant rhesus monkeys assigned to a high (25%), standard (12.5%), or low (3.5%) isocaloric protein diet from 3 to 9 months of age. Significantly lower increases in body, brain, liver, pancreas, and adrenal weights were observed in the low protein monkeys. Pituitary weights did not differ among infants in the 3 diets. Significantly higher brain/body and pituitary/body ratios of low protein infants indicated that the brain and pituitary were significantly less affected by the low protein diet than the body, pancreas, liver, and adrenals. The higher brain and pituitary/body ratios of low protein infants may be interpreted as a “sparing” of these organs similar to that of adults, or that the organs had passed their most rapid growth when the infants were exposed to the 3 protein diets from 3 to 9 months of age.

Sulfate, cycloleucine, and 3-O-methyl-glucose were introduced into the brain by three different routes: (a) brain perfusion, (b) blood injection, and (c) blood injection and blood perfusion simultaneously.

The value attained in the nervous tissue with sulfate, which is considered an extracellular marker, when administered by the two combined routes, was equal to the addition of data obtained by each route separately. Using the combined procedure (c) for cycloleucine, a higher value than that calculated from the sum of procedures (a) plus (b) was reached. The data of the combined introduction for methyl-glucose were in the range of those obtained by blood injection alone.

The significance of different routes of administration on the uptake of substances into the brain is discussed.

When aqueous solutions of ammonium hexachloroiridate(IV) are irradiated with visible light in an ammonia atmosphere, a photochemical reaction occurs in which the complex (IrCl₆)^2- ion is converted through a less negatively charged intermediate to an apparently neutral species. Solutions so irradiated lose rather rapidly the absorption peaks at 416, 433, and 487 mμ and display a new peak at 325 mμ. Nonirradiated solutions are quite inhibitory to the growth of Escherichia coli, but irradiated solutions are much less so. Solutions irradiated for 5–7 hr markedly retard cytokinesis of the bacterial cells. It was tentatively proposed that the product responsible for this inhibition of cell division in the presence of continued cell elongation may be cis-tetrachlorodiammine-iridium.

A new method for the assay of chick interferon (IF) was devised. Serial dilutions of IF were inoculated into wells made in the agar overlay covering chick embryo cells, and after 1 day's incubation at 37° the wells received a constant dose of the u mutant of Sindbis virus. Three days later a large plaque whose size was almost independent of the challenge virus dose appeared around the control well. This plaque formation was inhibited by the IF pretreatment. Thus, one monolayer dish, 90 mm in diameter, sufficed to titrate each IF sample. The highest IF dilution which reduced the normalized plaque diameter (the plaque diameter minus the cup diameter) to less than half that of control was comparable to the end point determined by the ordinary 50% plaque reduction test. The standard deviation of end points was approximately ±2-fold. A 1000-fold fluctuation in the challenge virus dose did not influence the IF titer determined. When a small-plaque clone of Sindbis virus was used and DEAE-dextran incorporated in the agar overlay, the same result was obtained.

Diuresis following gastric gavage of water was examined in germfree and conventional rats. Germfree rats began to excrete urine 1 hr later than the conventional group and the volume of urine excreted by the germfree animals was less than excreted by the conventional group. Saline excretion patterns were the same for the two groups of animals. When 4% glucose was administered subcutaneously, excretion patterns were similar to that obtained following gastric gavage of water except that the onset of excretion was delayed 2 hr in the germfree as compared with the conventional group.

Procedures for the preparation of highly purified concentrates of formalin-inactivated Coxiella burneti were developed. These procedures include the use of centrifugation, fluorocarbon, and brushite treatments. The final product was free of detectable host (egg) antigen and had only phase 1 complement-fixing activity. The relationship between concentration and optical density was confirmed for the concentrated material.

In rats starved for 2 days and then refed a 65% glucose diet for 2 days the activities of liver glucose-6-phosphate dehydrogenase and malic enzyme reached approximately twice normal levels. This overshoot of normal activity was totally prevented if 8-azaguanine was administered 24 hr or sooner after refeeding. If the antibiotic was administered 30 hr after refeeding, the overshoot was still inhibited, although to a lesser extent, while if 8-azaguanine was administered 36 hr after refeeding, no noticeable reduction in the overshoot was noted. The results indicate that the overshoot in the starved-refed experiment requires de novo RNA synthesis and that this de novo RNA synthesis seems to occur between 24 and 36 hr after refeeding. To further check this hypothesis, the effect of 8-azaguanine was studied on the 4-day overshoot in glucose-6-phosphate dehydrogenase and malic enzyme activities. It was found that the overshoot was totally prevented by injecting the antibiotic 30 hr or sooner after refeeding. If the antibiotic was injected 48 hr after refeeding, the activities of glucose-6-phosphate dehydrogenase and malic enzyme reached about 75% of the levels in untreated rats refed for 4 days. Since, the administration of 8-azaguanine for 2 days to ad libitum-fed rats caused about an equal reduction in glucose-6-phosphate dehydrogenase activity, but not in malic enzyme activity, the results could be interpreted in one of two ways: (i) that the de novo RNA synthesis necessary for the overshoot is not entirely completed by 48 hr after refeeding, or (ii) that the above mentioned RNA synthesis is completed within 48 hr after refeeding, but that 8-azaguanine reduces the level of functional RNA by interfering with the normal turnover of RNA.

Canine tracheal secretions obtained from a new system for studying respiratory tract mucous were examined by Ouchterlony double gel diffusion, immunoelectrophoresis, and gel filtration chromatography. Immunoglobulins of three classes, IgA, IgM, and IgG, were identified. The main immunoglobulin of canine tracheal secretions appears to be IgA. The tracheal pouch provides a useful model in which to study the secretory immune system of the dog.

Baboons inoculated intranasally with influenza virus A2/Phila. 101/68, a Hong Kong strain, excreted virus for as long as 25 days. Infection was associated with seroconversion and transmission to uninoculated control animals. The control animals also excreted virus and showed seroconversion. Treatment of inoculated baboons with poly I.C. delays or suppresses antibody formation and prevents it in uninoculated contact animals. In neither case is virus excretion consistently prevented.

Using a newly constructed, transparent isolation chamber preventing diffusion of India ink to adjacent tissues of the hamster mouth and neck, egression of dye to the regional, ipsilateral, submental lymph nodes takes place, but in a reduced fashion. It is suggested that the so-called “immunologically privileged” character of the hamster cheek pouch is related to a delayed and reduced lymphatic drainage from this site.

Adult Syrian hamster lung cells were exposed to six clonal lines of PARA (defective SV40) as well as to parental SV40. All the exposed cultures transformed. SV40 T and S antigens were synthesized in all the cells transformed by PARA, but could not be detected in the culture which transformed following exposure to SV40.

Replicating and nonreplicating DNA were isolated in an isopycnic density gradient from cultured fetal mouse skin cells after incubation with 5-bromodeoxyuridine for 20 hr. Benz[a]anthracene, when incubated in the cultures simultaneously with bromodeoxyuridine, binds to both replicating and nonreplicating DNA. The binding of benz[a]anthracene to mouse DNA is considerably less than that previously reported for 7,12-dimethylbenz[a]anthracene.

Hearts of animals subjected to a moderate thiamine deficiency were resistant to the necrogenic effect of isoproterenol which at the dose level used (80 mg/kg of body wt) produced massive infarcts in animals fed a normal control diet. The reason for the apparent protective effect is unclear. It is postulated that cardiac tissue from rats in early thiamine deficiency may have an increased capacity for anaerobic glycolysis, as part of the metabolic response to a decrease in the activity of enzymes essential for oxidative phosphorylation. This capability is not shared by cardiac tissue from control animals.

Studies were designed, using rabbit aortic strips, to investigate the possible role calcium (Ca²⁺) ions play in the recovery of depressed, drug-induced contractions of excised, isolated blood vessels. The present experiments demonstrated that: (i) excision of aorta from intact rabbits and the subsequent surgical preparation and incubation of helical strips, at physiologic temperature in vitro, severely impairs the development of full sensitivity, of these aortic smooth muscle cells, to a variety of vasoactive substances for a period of 3 hr. (ii) A close relationship was found to exist between the ability or inability of different vasoactive drugs (e.g., epinephrine, histamine, potassium, and barium) to induce a maximal contractile response and the total Ca²⁺ content (as quantitatively determined by atomic absorption spectrophotometry). And (iii) mechanical (surgical) injury may alter the in vivo Ca²⁺ content of arterial smooth muscle.

If the assumptions be valid that the lag phase of bacterial multiplication is constant when M. leprae are repeatedly harvested from untreated mice and passed to other mice of the same inbred strain, and that those M. leprae capable of multiplying in the mouse foot pad do so always at the same rate, then the results of these experiments may be interpreted to show that once the peak of bacterial multiplication has been reached, death of M. leprae ensues. Death of M. leprae appears to have occurred in mice during DDS treatment at the same rate as in the untreated mice, but the lag phase of bacterial growth was uniformly prolonged as a result of treatment.

Spleen and lymph node cells from rabbits hyperimmunized with coliphage MS-2 synthesized neutralizing antibodies when cultured in vitro. Antibodies synthesized in cell cultures in the absence of streptomycin neutralized phage MS-2 to a high titer whereas antibodies synthesized in the presence of 200 μg/ml of the drug had reduced neutralizing capacities. The difference in neutralizing activity was due to the fact that antibody preparations synthesized in the presence of the drug had either lower avidity and/or affinity for phage MS-2 than did antibody preparations synthesized in the absence of the drug.

The inhibition of the tryptic hydrolysis of benzoyl-dl-arginine-β-naphthylamide by homogenates of human and bovine cerebrum, cerebrum gray matter, cerebrum white matter, cerebellum, corpus callosum, medulla, thalamus, midbrain, and pons is reported. There is no significant difference between inhibitory levels of primarily gray areas and primarily white areas of brain. Dialyzed, lyophilized myelin does not inhibit tryptic activity. The reaction of brain homogenates with trypsin is rapid.

PGE₁ caused venodilatation in the isolated perfused canine gracilis muscle but not in the perfused hindpaw. Venoconstrictor responses to nerve stimulation, norepinephrine, and angiotensin were inhibited significantly and uniformly in the paw but not in the muscle. The results indicate that inhibition of venoconstrictor responsiveness by PGE₁ is not associated with nor dependent upon a direct dilator action of the prostaglandin.

In summary, we have shown that two topically useful antipsoriatic agents, anthralin and anthralin triacetate, both exert potent anti-inflammatory effects on oral administration. Anthralin further shows antiarthritic activity, inhibiting the cellular mediated immune processes as evidenced by suppression of both secondary lesions and skin wheal in the rat model. These data are preliminary in nature and further studies are in progress to elaborate on the biological profile of these two agents.

The effects of diet restriction, thyroidectomy, adrenalectomy, and ambient temperature (28 and 34°) on protein turnover rate (K) were studied in young (47–49 days) and old (572–605 days) male rats. The data indicate that thyroidectomy decreased K under all treatments. Adrenalectomized rats supplemented with salt and 300 μg corticosterone every second day had a similar K and growth rate as the control rats. Exposure to heat and restriction of diet decreased K significantly only in the young rats. The effect of heat is suggested to be associated with the voluntary reduced feed intake as a result of hyperthermia and depressed appetite.

A “generalized” aminoaciduria occurs in lead-intoxicated rats characterized by a 1- to 3-fold elevation in renal clearances of most amino acids. The increase in histidine clearance is exceptionally large, whereas, changes in glycine and valine clearances are slight. Tyrosine clearance is actually decreased.

Plasma glycine is greatly increased; lesser increases in plasma threonine and lysine were found. Plasma levels of other amino acids were the same or less than those of control rats.

The increase in renal clearances of amino acids is thought to result from impaired renal tubular reabsorption secondary to an effect of lead on the metabolism of proximal renal tubular lining cells. Hyperglycinemia may be prerenal reflecting the defect in prophyrin synthesis known to occur in lead poisoning. It is also suggested that the formation of metal-amino acid complexes may contribute to the excessive aminoaciduria.

An immunofluorescent focus assay for GLV is described. GLV was demonstrated in tissues and fluids of AKR mice, as well as in tumor cells from a spontaneous lymphoma of AKR mice.

A sensitive 50% focus reduction assay for neutralizing antibody to GLV is described.

Daily injections of hydrocortisone and dexamethasone significantly increased the serum sialic acid in dogs. Dexamethasone, a steroid with 30 times more glucocorticoid activity than hydrocortisone, produced a significant response at a much lower dosage than hydrocortisone.

1. Two protein polysaccharide fractions. PPL-2 and PPL-3, were isolated from the costal cartilage of rat, 6 months, 1 and 2 years old.

2. The PPL-3 sedimented as a single component in the samples prepared from 2-year-old rats. In contrast, the PPL-2 from 2-year-old rats and PPL-2 and PPL-3 from 6-months- and 1-year-old rats were heterogeneous.

3. The chemical compositions (g/g of dried wt) protein: uronic acid: hexose: hexosamine are 0.324: 0.221 :0.054:0.248 and 0.121:0.270:0.061:0.272 for PPL-2 and PPL-3, respectively. Ninety-five % of the hexosamine was galactosamine in both preparations.

4. The amino acid composition of rat costal cartilage is compared with that of human costal cartilage and bovine nasal cartilage.

The intake of simple sugars of 6 moderately hypertriglyceridemic, hypercholesterolemic subjects was reduced for 60 days. This restriction led to a moderate weight loss, a normalization of their previously elevated pre-beta lipoprotein levels and a moderate decrease in their pre- and postprandial hypertriglyceridemia. The elevated serum cholesterol and pre- and postprandial serum insulin levels were not normalized by the dietary change.

C. kistolyticum collagenase has been shown to be inhibited by acetylsalicylic acid, flufenamic acid, and indomethacin. Effects with phenylbutazone were variably manifested as inhibition or activation depending upon the concentration of drug used. Cortisone acetate induced activation of collagenase while slight inhibition was found with dexamethasone. Crystalline pancreatic elastase (porcine) was shown to be inhibited by phenylbutazone but cortisone acetate and dexamethasone had no effect. Flufenamic acid, acetylsalicylic acid, indomethacin, and some structurally related compounds caused activation of the enzyme.

Trypsin in the absence of calcium is activated as much as 575% by nonsteroidal anti-inflammatory compounds when assayed with azocoll as substrate. Using a small synthetic compound, N-benzoyl-dl-arginine p-nitroanilide, as substrate much less activation was noted. Chymotrypsin was variably affected by less than 18% while no effect of the drugs was found on thrombin. Subtilisin was found to be inhibited slightly (less than 30%).

The plasma of a patient with acute monomyelogenous leukemia when used as an antigen in Ouchterlony tests reacted with hamster serum containing anti-avian leukosis group-specific antibodies. Of the two immunoprecipitin bands seen, one merged in a reaction of identity with a band formed by AMV and the antibody-containing hamster serum. Since the leukemic plasma did not react with normal hamster serum, normal chicken plasma or anti-normal chicken serum in immunodiffusion tests, the results of this study represent a true cross reaction between antigens from a human leukemic source and antibodies directed against the avian leukosis group-specific antigens. Electron microscope studies on the human plasma revealed viruslike particles in a concentration greater than 5 × 10⁷ particles/ml based upon direct counts. As yet the data do not allow for any correlations to be made between the immunologic findings and the presence of virus-like particles in the plasma.

The relationship between H and K output from vagally denervated fundic pouches under steady-state histamine stimulation was determined when secretion was either inhibited by two pharmacologic agents—atropine and cyproheptadine—or the dose of histamine was lowered. The correlation between H and K decline exceeded 0.9 with all three techniques. There was poor correlation between the change in H output and Na output. These findings suggest that gastric H and K secretion are coupled. The relevance of this coupling to a proposed electrogenic mechanism for gastric H secretion is noted. Inhibition of histamine-stimulated gastric secretion with the agents employed altered the pattern of gastric electrolyte secretion in a manner different from that of acetazolamide inhibition.

The mechanism of dopamine-induced inhibition of hemoglobin synthesis in chick blastoderm in vitro was investigated. Dopamine did not reduce the incorporation of ¹⁴C-leucine or ¹⁴C-aminolevulinic acid (ALA) into protein. The total protein per blastoderm was similar in both the dopamine-treated and control blastoderms. Addition of exogenous ALA to the dopamine-treated medium did not reverse the effect of dopamine on hemoglobin synthesis.

Ethanol (50 ml) inhibits the formation of hippurate from benzoate but has no effect on the maximum rate of formation of salicylurate from salicylate in healthy human subjects. This is consistent with other evidence showing that the conjugation of benzoate and salicylate with glycine in man involves different rate-limiting steps.

Studies were made on (a) human papillary muscles derived during open heart surgery in various degrees of failure, and (b) experimentally produced failing guinea pig hearts. There was a significant decrease in norepinephrine from 1.22 to 0.34 μg/g in the experimental guinea pig hearts as compared to normal. There was also a significant decrease in norepinephrine from 0.37 to 0.16 μg/g in human papillary muscle as the degree of failure increased. Glucose-6-phosphate decreased significantly from 0.30 to 0.09 μmoles/g in the human papillary muscles with increasing degree of failure. Similarly there was a significant rise in glycogen from 3.42 to 6.56 mg/g in the guinea pig hearts and from 5.69 to 8.89 mg/g in the papillary muscles. The differences in glycolysis and citric acid cycle intermediates were not significant. The ATP/ADP ratio decreased from 3.84 in grade II failure to 2.47 in grade IV failure. This ratio is a reflection of the degree of aerobiosis in mitochondria metabolism and indicates in failure a shift to more aerobiosis. The values on guinea pig heart adenyl cyclase activity were not statistically different, being 16.9 and 18.7 μmoles/100 g of tissue/15 min.

The accelerator response to sympathetic nerve stimulation in perfused rabbit hearts was significantly greater during than before angiotensin infusions. A similar effect of angiotensin at other adrenergic neuroeffector sites has been reported previously, and mechanisms of action that have been suggested for this influence include sensitization of the receptor site to the action of norepinephrine, prevention of the re-uptake or facilitated release of norepinephrine. Evidence is presented in the experiments reported here that at cardiac neuroeffector sites angiotensin does not sensitize the receptor sites nor prevent the uptake of norepinephrine, since the accelerator responses to norepinephrine were similar before and during angiotensin infusions. It appears most likely, therefore, that the mechanism by which angiotensin causes an increased accelerator response to sympathetic nerve stimulation in these preparations is to potentiate the release of norepinephrine from the active adrenergic nerve endings.

The key role of the macrophage as the afferent component of the immune reflex arc is well documented (6–8, 10, 11, 19, 22, 31). Furthermore, Frei et al. (9) demonstrated that phagocytosis is an essential step in the development of the primary immune response while others have shown that the transplantation of macrophages into newborn mice (1) and rabbits (19) will promote the early development of immunocompetence. In view of these findings, it would be expected that the administration of chemotherapeutic agents which alter the normal phagocytic function of the reticuloendothelial system (RES) would induce a corresponding alteration in the immune response. Indeed, Wooles and Di Luzio (31) initially demonstrated that RES depression was associated with a decreased immune response while RES stimulation resulted in an increased antibody titer.

Previous studies from this laboratory (25) have shown that a single injection of antilymphocytic serum (ALS) impairs phagocytic activity of the reticuloendothelial system (RES), as reflected by a depressed intravascular clearance rate of gelatinized RE test lipid emulsion. The ALS-induced depression in phagocytosis was associated with a selective decrease in Kupffer cell phagocytosis. In vitro studies which employed both serum and liver slices derived from either normal or ALS-treated animals also indicated the ability of ALS to induce phagocytic impairment. These in vitro studies (25) suggested that the depression of RES activity by ALS could be attributed to an exclusive defect in the cellular compartment of the RES since no alteration in circulating phagocytic-promoting activity was found in ALS-treated animals. Furthermore, a direct injurious effect of ALS on Kupffer cells was demonstrated, not only by ALS-induced impairment of Kupffer cell phagocytic activity, but also by the cytotoxic action of ALS on these macrophages (25).

Ultrastructural and biochemical studies were performed on the brain and liver of a 21-week-old embryo obtained by a therapeutic abortion from a woman who had previously a child with Tay-Sachs disease. Similar studies were carried out on brain and liver of a 14-week-old infant afflicted with this disease. In both cases there was absence of hexosaminidase A activity in liver and brain, and increased amounts of G_M2 ganglioside were found in cerebral tissue. Electron microscopically, it was possible to trace the evolution of the membranous cytoplasmic bodies from prenatal ill-defined finely granular cytoplasmic bodies to the membranous cytoplasmic bodies seen in the early postnatal stage of the disease. The study, furthermore, indicates that the in utero diagnosis of Tay-Sachs disease can be confirmed by morphological and biochemical studies on the fetus.

Dialytic removal of alpha-methyldopa (Aldomet) has been investigated in chronic uremic patients undergoing either hemodialysis or peritoneal dialysis, using ¹⁴C tracer techniques. A mean of 60% of the estimated absorbed radioactivity was recovered in the dialysate of 3 patients undergoing 4 hemodialyses; the mean relative dialysance of radioactivity from alpha-methyldopa and its products was 0.34. A similar amount of radioactivity was recovered in the dialysate of 2 patients undergoing peritoneal dialysis.

The antihypertensive action of administered alpha-methyldopa and its major metabolite (a mono-O-sulfate conjugate) may be diminished by hemodialysis. This effect could contribute to the reemergence of hypertension occasionally observed in the postdialysis period in patients receiving alpha-methyldopa therapy.

Norepinephrine levels were measured in seven different regions of canine hearts from four groups of animals: controls, animals subjected to section of the ventrolateral cervical cardiac nerve (Group I), animals in which the tissues surrounding the base of the pulmonary artery were dissected (Group II), and a fourth group in which both surgical procedures were done (Group III). Results of this study suggest the following conclusions: (i) The major sympathetic innervation of the ventricles is supplied by fibers which traverse the pulmonary artery and VLCCN; (ii) The major sympathetic innervation of the atria is via some pathway other than the pulmonary artery and VLCCN, although fibers coursing through the peripulmonary region supply a large number of fibers to the atrial myocardium; (iii) The interventricular septum and base of the right ventricle receive their major sympathetic innervation via fibers which pass through the peripulmonary region; (iv) The left ventricle and right ventricular apex are supplied about equally with sympathetic fibers arriving via both pathways studied.

Tritium-labeled diphenhydramine given iv to rhesus monkeys produced a rapid drop in plasma levels of unchanged drug, but the total tritium activity rose slowly over a 4-hr period to levels severalfold greater than those observed 1 min after dosing. This was attributed to rapid removal of drug by the tissues, followed by a slow return of metabolites to the plasma. The major metabolite, strongly bound to plasma protein, was identified as diphenylmethoxyacetic acid. Similar observations were made in the dog, rabbit, guinea pig, and mouse; but not in the rat, which did not form diphenylmethoxyacetic acid. Species differences were noted in the conjugation of this metabolite with glutamine in the monkey, and with glycine in the dog.

Plasma 11-OHCS were measured in 12 subjects during 7 hr of general anesthesia with endotracheal nitrous oxide (N₂O) and halothane, and halothane alone. The 5 subjects who received the N₂O-halothane anesthesia showed an early rise in plasma 11-OHCS, which corresponded to the duration of the excitation phase. After the short rise, the plasma 11-OHCS fell to hypoadrenal levels. The subjects who received halothane only (rapid induction of anesthesia) showed no rise in plasma 11-OHCS, but the 11-OHCS fell to hypoadrenal levels after induction. After 2 to 4.5 hr of general anesthesia, the plasma 11-OHCS rose spontaneously and remained elevated until the end of anesthesia. The sudden rise was not due to changes in feedback threshold and did not correlate with changes in concentration of the anesthetic. The urinary catecholamine secretion was not significantly altered during the anesthesia compared to a control period.

β-2-Thienylalanine, cycloleucine, and parachlorophenylalanine have been shown to acutely reduce intestinal absorption of an oral phenylalanine load. Combined with phenylalanine, they reduce plasma tryptophan levels more than phenylalanine alone.

Whether their oral administration will be of benefit in allowing a more liberal diet in phenylketonuric children requires more investigation.

The indigogenic technique, a simple, specific, and reproducible method for demonstrating hydrolytic enzymes, has been adapted for electron microscopy, β-d-Galacto-sidase has been demonstrated in rabbit alveolar macrophages and other cell types with the same halogenated indoxyl substrate used in light microscopy. The reaction product is substantive and is readily identified in the electron microscope. The method is applicable to other hydrolytic enzymes.

Studies were made of the changes in blood flow in rabbits after localized depletion of femoral marrow or nutrient vessel ligation. Our findings confirm that the nutrient artery is the principal source of flow to medullary tissue in the diaphysis of long bones. They indicate further that (i) there is a highly effective collateral circulation to the medullary cavity, (ii) marrow regeneration is associated with an increased blood flow, and (iii) normal blood flow is restored at a time when the regenerated marrow after a localized depletion is indistinguishable from normal marrow.

Extirpation of thymus within 24 hr after birth increased the sensitivity of rats to steroid hormones injected at the age of 5 days. In 56-day-old males the atrophy of testis and of accessory sex tissues produced by a single injection of estradiol benzoate was more severe in thymectomized animals than in sham-operated controls. In female rats the atrophy produced by injecting the same steroid resulted in greater atrophy of the uterus in thymectomized animals than in controls.

The studies reported present evidence that a free or intact sulfhydryl group is involved in platelet adhesion to connective tissue. Exposure of platelets to the readily penetrating sulfhydryl inhibitors NEM or PHMB immediately blocks their ability to adhere to connective tissue. PHMBS, which penetrates platelet membrane very slowly, produces an inhibitory effect only after prolonged incubation. These observations suggest that an SH-containing substrate affecting the adhesion reaction is probably located beneath the plasma membrane of the platelet.

On a per weight basis, normal mature male and female rats retained the same amount of ⁸⁵Sr at 45-days postinjection, whereas hyperphagic castrate females retained less. However, no difference in ⁸⁵Sr retention was observed between castrate rats on an ad libitum diet and those on a restricted diet. When daily injections of a physiological dose (5μg) of estradiol were administered, retention was (i) significantly greater (12–15%) in estrogen-treated castrate and normal rats on an ad libitum intake compared to untreated rats; (ii) significantly greater (24%) in estrogen-treated castrate rats on a restricted intake compared to untreated castrate rats on an ad libitum intake; and (iii) generally significantly greater in the femurs of estrogen-treated rats compared to untreated rats. Possible mechanisms by which retention was enhanced by the action of estrogen are discussed.

Leptospirosis is a zoonotic disease which affects many species of animals as well as man. In ruminants, Leptospira pomona is frequently the etiologic agent. The clinical signs of infection in sheep include fever, icterus, and a hemolytic anemia. Several investigations have failed to elucidate conclusively the mechanism of this anemia (1–4). The detection of a transiently occurring cold-hemagglutinin (CHAn) associated with the hemolytic crisis in the plasma of experimentally infected anemic sheep, has recently been reported (5). Some characteristics of this CHAn are reported here.

Materials and Methods. A total of 15 sheep free of lepotospiral agglutinins was used in three separate experiments. All sheep were housed in isolation units, provided with hay and a complete pelleted ration and water ad libitum. One noninfected control was maintained in contact with the infected sheep in each experiment. The sheep were infected with Leptospira pomona by subcutaneous inoculation with 2.5 ml of a 10% emulsion, in 0.85% NaCl solution, of liver and spleen obtained from leptospiremic, moribund hamsters.

The microscopic agglutination test employing live L. pomona as antigen, using 7- to 10-day cultures in Stuarts' fluid medium (Difco Laboratories, Detroit, Mich.) with 10% rabbit serum, was used for the detection of leptospiral agglutinins (6) in the serum of the experimental sheep. Rectal temperatures and packed RBC volumes and hemoglobin values were determined daily to define the development of the infection and the anemia which has been described in detail elsewhere (5).

For the isolation of CHAn, large volumes of blood were obtained from normal control sheep or experimentally infected sheep during the hemolytic crisis in either Alsever's (7), ACD (8) or citrate (1 vol of 0.5 M na citrate for 5 vol of blood) anticoagulant solution. Plasma was separated at 25° and its globulin fraction concentrated by precipitation at 40% saturation with ammonium sulfate.

A successful routine method of developing cell lines from diploid hamster cells has been established. Bovine serum albumin fraction V was essential for serial long-term culture. Stimulation of growth was optimal at albumin concentrations between 0.5 and 1%. In the presence of albumin, hamster embryonic and neonatal lung cells and whole hamster embryonic cells developed into established lines.

Tissues obtained from adult cats were destroyed, when cultured, by a slow-growing syncytia-forming virus which was transmitted to cultured cells of several species, including human. Ninety percent of the cats obtained were infected. The agent is myxovirus-like, but does not induce interferon production.

The effect of insulin on the creatine content of blood and urine was studied in rats which were made creatinuric by the ip injection of creatine. The results indicate that 0.5–2.0 units of NPH insulin administered sc 2 hr prior to the injection of 5 mg of creatine prevented creatinuria induced by creatine loading. When rats were injected with 5 mg of creatine, the blood creatine concentration rose to 190% of the preinjection control value after 60 min and then fell to 180% of the control after 2 hr. The blood creatine concentration in rats treated with 2 units of insulin increased to 114% of the control value 1 hr after creatine loading and then decreased slightly after 2 hr. These results show that the hyper-creatinemia which occurs in rats shortly after creatine loading can also be suppressed by insulin, suggesting that the action of the hormone in preventing load-induced creatinuria is related to its effect on the blood creatine concentration, rather than to an effect on the kidneys per se.

Preparations of high molecular weight rI_n:rC_n were exposed to sonic radiation. A decrease in the average molecular weight of the polynucleotide complexes after treatment was accompanied by an exponential decrease in viscosity of the preparation, an increase in the sensitivity of the polynucleotide complex to degradation by pancreatic ribonuclease, a decrease in the thermal transition midpoint, and a decrease in the hyperchromicity observed during thermal transition.

The lower molecular weight rI_n:rC_n complexes were tested for their capacity to induce interferon in rabbits and resistance against VSV infection in cell culture and PVM infection in mice. Sonic-treated preparations of rI_n:rC_n reduced to an average molecular weight of approximately 4.6 × 10⁵ were markedly reduced in capacity to protect mice against PVM infection, compared with untreated rI_n:rC_n preparations containing complexes having an average molecular weight of approximately 7.8 × 10⁶. The capacity of sonic-treated rI_n:rC_n to induce production of rabbit interferon and resistance to virus infection in cell culture was more resistant to molecular weight reduction. Significant decrease in activity was observed in rI_n:rC_n fractions with approximate molecular weights less than 1.2 × 10⁵.

Reduction in the size of rC_n by sonic radiation caused a decrease in viscosity when complexed with rI_n of high molecular weight but did not bring about a decrease in protective activity of the rI_n:rC_n against PVM or VSV viruses. Greater reduction in size of rC_n by treatment with RNase resulted in progressive loss of capacity to complex with rI_n and to protect against viral infections. The capacity of rI_n:rC_n to induce resistance to VSV virus in vitro and to PVM virus in vivo was more dependent upon maintaining a high molecular weight of rI_n than of rC_n. Activity was markedly diminished when the average molecular weight of rI_n was below 1.9 × 10⁵ and of rC_n below 2.3 × 10⁴.

Treatment of L cells with a detergent-based lysing solution caused the formation of a precipitate which contained DNA and protein. Increasing doses of X-rays decreased the amount of DNA which precipitated; at the same time, the amount of DNA which remained in solution increased. Inclusion of EDTA in the lysing solution prevented the formation of the precipitate.

The addition of all the nonessential amino acids in general, and aspartic acid in particular, of ATP, and of small amounts of “amino acid activating enzymes” to liver homogenates produced a definite increase in the rate of protein degradation. The activating effect of the amino acids was shown to be dependent on the presence of ATP and the activating effect of the “amino acid activating enzymes” was shown to be dependent upon the presence of aspartic acid. It was concluded that the activating species may be the aspartyl adenylate which would provide an intermediary between protein synthesis and protein degradation.

The isolated rat kidney was perfused at constant flow rate with physiological salt solution (PSS). Addition of rat plasma or a vasoactive fraction of hog plasma caused an increase in renal vascular resistance. The time course of the responses caused by these two agents was the same, but differed from that of the pressor responses caused by epinephrine, angiotensin, KCl, serotonin, or vasopressin. The ability of the vessels to respond to plasma factor was lost during perfusion with “Ca-free” PSS, whereas the ability to respond to epinephrine was not; the constrictor response produced by the plasma factor was greater during perfusion with “high-Ca” PSS, that produced by epinephrine was not.

Resting levels of bioassayable (BA) and radioimmunoassayable (RIA) pituitary growth hormone (GH), radioimmunoassayable plasma GH, and hypothalamic GH-releasing (GRF) activity were determined at intervals during a controlled 24-hr light-dark cycle in intact prepubertal female rats. A gradual parallel increase in BA and RIA pituitary GH was found from late morning through afternoon, with peak levels at 1800–2100 hr. Reattainment of values close to the morning levels took place during the night.

Radioimmunoassayable plasma GH exhibited wide fluctuations with peak concentration at 1800 and 0300 hr. Measurements of hypothalamic GRF activity were unable to evidence daily excursions in phase with the clear pituitary rhythm.

By means of a high fidelity fiberoptic manometer system, right and left ventricular pressures and their first derivatives have been measured at thoracotomy in 9 anesthetized and artificially ventilated golden Syrian hamsters, and are reported along with normal values for pH, pCO₂, and pO₂.

Nineteen Syrian hamsters of the BIO 14.6 strain, with hereditary cardiomyopathy and clinical signs of congestive heart failure were studied in similar manner. At mean arterial pH of 7.45, significant hypoxemia was demonstrated, associated with hemodynamic evidence of depressed left and right ventricular function. Biventricular heart failure was characterized by significant bradycardia, elevation of left and right ventricular filling pressures, decrease in left ventricular systolic and maintenance of right ventricular systolic pressure.

The degree of cross immunity was investigated among 10 strains of Chlamydia psittaci isolated from various mammalian and avian hosts. Mice were immunized intraperitoneally with nonviable tissue-culture vaccines prepared from each strain and tested for their resistance to homologous and heterologous challenge. Although most strains provided some degree of cross protection, the strains appeared to fall into two antigenic groups. At least a bivalent vaccine will apparently be required to give protection against a broad spectrum of strains.

Glomeruli with viable cells were isolated from rats, dogs, and humans in large numbers by a modification of the Karkower-Greenspon method. Cellular outgrowths having the characteristics of epithelial cells were observed. A second cell type was identified within glomerular loops and remained intact as long as glomeruli were recognizable. A third cell type which resembled smooth muscle cells was seen occasionally in the outgrowth.

A study was made of the loss of hemagglutinin by vaccinia virus under the influence of an hemagglutinin inhibitor originating from a mouse ascites tumor. It was found that the inhibitor reacted with the hemagglutinin by forming a dissociable complex. In examining the possible mechanisms by which stable, hemagglutinin-negative virus is formed, it was noted that the inhibitor exhibited no neutralizing action against hemagglutinin-positive virus, that hemagglutinin negative virus could not be found in cloned populations of hemagglutinin-positive virus, and that there was no obvious growth advantage shown by the hemagglutinin-negative virus in the presence of inhibitor. For these and other reasons the hypothesis is presented that the inhibitor facilitates the emergence of stable, hemagglutinin-negative virus by complexing with and gradually eliminating the hemagglutinin, which might be necesary as a template for the formation of more hemagglutinin.