Experimental Biology and Medicine

The clinical and serological testing of a group Y meningococcal polysac-charide vaccine is described. Only minor local reactions at the injection site were observed. High levels of bactericidal antibody were observed in 93% of the individuals 3 weeks after receiving the vaccine.

Viridin B, a bacteriocin of Streptococcus mitis (S. mitior), had no bactericidal effect on indicator strains grown on blood agar, whereas activity was readily demonstrable on the same agar devoid of blood. Addition of viridin B to human, ovine, bovine, or rabbit erythrocytes caused immediate lysis of the cells and total inacti-vation of the bacteriocin. Inactivation was effected also by erythrocyte lysates. Activity in the lysates was heat resistant, nondialyza-ble, and insensitive to proteolytic enzymes. Chromatography on a Bio-Rad P-100 column indicated that the inhibitory activity resided exclusively in hemoglobin. Fraction-ation of hemoglobin showed that heme and not globin was totally responsible for this inactivation. The effect of heme appeared to be directly on viridin B rather than on blockage of indicator cell receptors. Cyto-chrome c, bilirubin, and ferrous and ferric ions had no effect on the bacteriocin. Among various other ions tested, only Ca²⁺ inhibited viridin B. Urea was also inhibitory but only in high concentrations.

Geldanamycin, an ansamycin antibiotic having anti-oncornavirus properties, was shown to completely inhibit the induction of measurable endogenous rat leukemia virus by 5-iodo-2′-deoxyuridine in a cell line of Fischer rat embryo cells and to protect the same cells from transformation by the polycyclic hydrocarbon 3-methyl-cholanthrene. Protection was induced at a dosage that was not only non-toxic but slightly stimulatory to cell growth.

The authors wish to thank R. J. Huebner, A. E. Freeman, and E. A. Gregory for their assistance in the preparation of this manuscript.

Activity of N⁵-methyltetrahy-drofolate-homocysteine cobalamin methyl-transferase was determined in sonicates of bone marrow obtained from five patients with chronic erythremic myelosis (Di-Guglielmo syndrome), three patients with severe untreated pernicious anemia, and eight normal persons. In four of the five patients with chronic erythremic myelosis, enzymatic activity was higher than in normals, and addition of methylcobalamin did not affect enzymatic activity, suggesting that the enzyme exists as the holomethyltransfer-ase. Increasing essential substrates such as S-adenosylmethionine, homocysteine, and methyltetrahydrofolate to fourfold the level used in the standard assay did not affect enzymatic activity significantly. Increased activity of this enzyme in chronic erythremic myelosis may relate to the high proliferative capacity reflected by increased cell turnover and intramedullary cell death.

Anti-renin and hypotensive effects of synthetic PEs were examined.

(i) Eighteen PEs including optical isomers were newly synthesized. Arachidonic acid, linolenic acid, and stearic acid were substituted at the positions of β, γ, or both. Natural PE was extracted from porcine kidney, and the lyso form was prepared by treatment of phospholipase A.

(ii) Anti-renin activity of these compounds was determined using high-renin plasma obtained from the dog. The inhibition of renin activity was expressed as a percentage of the reduction in the production rate of angiotensin I as measured by radioimmunoassay.

(iii) The inhibitory effects of PE(β-C₁₈ ⁼³, γ-C₁₈) series, d- and DL-PE(β-C₂₀ ⁼⁴, γ-C₁₈), and dl- and l-PE(β-C₁₈, γ-C₂₀ ⁼⁴) were greater than that of the natural PE, but did not exceed the effect of lyso-PE.

(iv) Hypotensive effect was evaluated in conscious normotensive, spontaneously hypertensive, and renal hypertensive rats by daily im injection of the test compounds.

(v) Following repeated administration of natural PE, d-PE(β-C₁₈, γ-C₂₀ ⁼⁴), and d-PE(β-C₁₈, γ-C₁₈ ⁼³) to renal hypertensive rats, blood pressure decreased by more than 30 mm Hg. d- and DL-PE(β-C₁₈ ⁼³, γ-C₁₈ ⁼⁴), dl-PE (β-C₁₈, γ-C₁₈ ⁼), and dl-PE(β-C₁₈, γ-C₁₈ ⁼⁴) lowered pressure more than 40 mm Hg. dl-PE(β-C₁₈, γ-C₁₈ ⁼⁴) showed hypotensive effects both in renal hypertensive and spontaneously hypertensive rats, but not in normotensive rats.

The phospholipid compounds were synthesized and donated by Dainippon Pharmaceutical Co., Ltd. Thanks are also due to M. Ohara for preparing the manuscript.

Chlorpromazine (CPZ) and several of its metabolites were tested for in vitro cytotoxicity, as measured by the efflux of aspartate aminotransferase to the surrounding medium, toward isolated rat hepa-tocytes. Exposure of liver cells to CPZ, at a concentration of 9 × 10^-5 M, led to enzyme leakage. The demethylated metabolites, mono- and didesmethyl-CPZ, were three and six times, respectively, more potent than CPZ. Hydroxylation of the tricyclic ring at the 7 or 8 position gives rise to compounds that were slightly less active than the parent compound, while oxidation of the sulfur atom resulted in inactive analogs. The presence of calcium in the medium had no apparent effect on the response of the hepatocytes to CPZ.

Circulating levels of LH, FSH, estradiol and progesterone were measured by radioimmunoassays in daily serum samples throughout the menstrual cycle of seven adult cynomolgus monkeys. The composite pattern of these hormones in cynomolgus monkeys strongly resembles that reported for rhesus monkeys, and is similar to that in the menstrual cycle of women. Thus, in the face of diminishing supplies and higher costs of rhesus monkeys, the cynomolgus monkey can also serve effectively as a model for studies in primate reproduction.

The expert technical assistance and animal care by D. L. Barber, C. K. Turner, and J. Lewis, Jr., are gratefully acknowledged.

Essential fatty acid-deficient rats were subjected to fasting-refeeding or partial hepatectomy to stimulate liver phos-pholipid and membrane formation under conditions of limited essential fatty acid (EFA) supply. Refeeding after fasting decreased the proportion of arachidonate in liver phospholipid fatty acids only slightly, i.e., from 6.8% in nonfasted rats to 5.3% after 3 or 7 days of refeeding, whereas ei-cosatrienoate decreased from 19.8% in nonfasted rats to 13.0% after 3 days of refeeding, with a return to nonfasted levels after 7 days. Activities of liver glucose-6-phosphate dehydrogenase and fatty acid synthetase in fasted-refed EFA-deficient rats did not differ significantly from values in deficient rats fed ad libitum. Considerable increase in liver weight (ca. 3-8 g or at least 50% of the estimated preoperative weight) occurred after partial hepatectomy of EFA-deficient rats. The proportion of arachidon-ate in phospholipid fatty acids was slightly lower after hepatectomy than before.

These results indicate that: (a) little of the arachidonate in EFA-depleted liver is used for lipoprotein formation and transport after fasting-refeeding, whereas eicosatri-enoate is available; (b) fasting-refeeding of EFA-deficient rats does not increase activities of liver glucose-6-phosphate dehydrogenase and fatty acid synthetase above the already elevated levels in EFA-deficient rats fed ad libitum; (c) considerable new liver tissue can be formed after partial hepatectomy even when EFA levels in phospholip-ids are very low.

Supported in part by USPHS Grant No. AM 12024.

Formation of cellular aggregates by rat, mouse, hamster, and human transformed cells was compared to aggregate formation by untransformed control cells. Viability and proliferation of cells in the aggregate form were found to correlate well with tumorigenic potential regardless of the method of transformation (spontaneous, chemical, or virus-induced). This assay has the potential for a fast and accurate means of evaluating in vitro transformation.

Epinephrine causes a biphasic contraction of rabbit aorta, consisting of (i) a fast component, F, ascribed to release of intracellular calcium, and (ii) a slow component, S, ascribed to calcium movement into the muscle cell. Angiotensin produces a single-phase contraction of uncertain calcium source. Insight into the latter might be gained if angiotensin contractions consistently resembled the F or S epinephrine response. Contractions of rabbit aorta strips produced by both drugs were therefore compared during five interventions which had dissociated effects on F or S epinephrine responses. These interventions consistently altered the angiotensin responses in the same way as they affected epinephrine F responses, and differently from their effects on epinephrine S responses. These results are compatible with the view that the likely major source of activator calcium for angi-otensin-induced contractions of rabbit aorta is intracellular, although a small extracellular calcium contribution could not be excluded.

Cholesteryl ester synthesis by the microsomal fraction from rat hepatoma cells was stimulated by preincubation of the microsomal fraction with lipoproteins obtained from hyperlipemic rabbit sera. Lipoproteins from normolipemic sera had no stimulatory effect. Growth of cells in hyperlipemic rabbit sera also increased microsomal cholesteryl ester synthesis. Increased cholesteryl ester synthesis is accompanied by an increased microsomal-free cholesterol content.

We studied the effect of soma-tostatin on various metabolic parameters in the fasted intact rat and in the eviscerated rat with a functional liver. In the fasted intact animal, high doses of somatostatin produced an elevation of blood glucose and ketone bodies together with a decrease in plasma FFA, total and esterified cholesterol, and urea nitrogen. We have postulated, therefore, that high levels of somatostatin (100 μg) may cause a functional endocrine pancreatectomy in normal rats. The metabolic consequences are due more to the insulin deficit than the lowered glucagon levels. Somatostatin had no effect on any of the parameters measured in eviscerated rats. We concluded that somatostatin has no extrapancreatic metabolic effects in this model.

We gratefully acknolwedge the constructive advice of Dr. John Gerich as well as his kind gift of somatostatin.

This study was supported in part by USPHS Grant No. AM 16342-02.

Using dissociated Rathke's pouch epithelial cells from 11- to 13-day-old fetal rats as starting material, we have successfully established 11 NRR (normal rat Rathke) cell lines. It was necessary to supplement the growth medium with a rat fetal brain extract in order to induce cell growth and differentiation. These NRR cell lines produced no detectable anterior pituitary hormones unless adult rat median eminence (MEE) extract was added to the culture medium. Following the addition of MEE to the culture medium the NRR cell lines continued to produce from one to six anterior pituitary hormones. The NRR cell lines all show a normal diploid karyotype and have exhibited good growth characteristics through 18 cell passages. From one of the NRR cell lines (NRR-5) 65 clones of normal diploid anterior pituitary cells have been established. Fifty-six of these clones have been examined for hormone production, and each clone examined has been shown to produce one, two, or three hormones.

The effects of EDTA, divalent metal ions, and nucleotides on serum and liver glycoprotein sialyltransferase were studied. EDTA, at concentrations up to 16 mM, increased the transfer of [¹⁴C]NANA from CMP-[¹⁴C]NANA to desialyzed fe-tuin, by serum enzyme, while Mg²⁺ and Mn²⁺ at concentrations of 5-20 mM strongly inhibited the transfer. Nucleotides showed marked inhibitory effects on the transfer reaction. The extent of inhibition increased with the number of phosphate groups in the molecule. The enzyme in liver, on the other hand, required divalent metal ions for optimal activity. Also, UDP and UTP stimulated the enzyme in the liver.

This investigation was supported by NIH Grants Nos. HD-01823 and NS-11670. The authors wish to acknowledge the able technical assistance of Lora Nunes.

GH-RIH and its two analogs, D-Trp 8 -somatostatin and D-Cys 14 -somatosta-tin have been tested for their effects on gastric and pancreatic secretion in chronic gastric and pancreatic fistula dogs. All three peptides caused similar competitive inhibition of pentagastrin-induced gastric acid and secretin-induced pancreatic bicarbonate secretions. This study indicates that GH-RIH analogs, which were shown to have a dissociated action on pituitary and endocrine pancreatic secretion, are essentially as equi-potent as GH-RIH itself on gastric and pancreatic secretions.

When treated with uv radiation at dosages that abolished infectivity and prevented synthesis of detectable viral DNA or antigens, SFV remained able to modify the cultural behavior of DRK₃ cells and to make them susceptible to unrelated VSV. These cellular modifications were not induced, however, when the input SFV was excessively irradiated. The results suggest that a functional SFV genome is required to alter the DRK₃ cells and that early gene functions of SFV, before synthesis of viral DNA or major antigens, are involved in the modification process.

The antilymphoma activity and blood clearance behavior of the glutamin-ase-free L-asparaginase from Vibrio succino-genes was tested in C3H mice with transplanted 6C3HED lymphosarcoma. Seven animals in which tumors had been implanted 12 days earlier each received two ip injections of 0.33 IU of homogeneous enzyme per day over a 4-day period. All animals appeared to be in complete regression 3 days after the injections were terminated and showed regression profiles that were at least comparable to those obtained with a second group of 6C3HED mice injected with equivalent levels of EC-2 L-asparaginase. The tumors did not return within 30 days in the enzyme-treated groups, whereas all animals injected with buffer or heat-inactivated V. succinogenes enzyme died during this period. Half-lives of 17-42 hr were observed for the V. succinogenes L-asparaginase in the blood stream of eight tumor-bearing mice. These results demonstrate that the L-asparaginase from V. succinogenes is an effective antilymphoma agent.

We thank David Lester and David E. Mallon for assistance with the statistical analyses and K. Sieglinde Neuhauser for aid with the tumor measurements.

The in vivo effects of a phos-phodiesterase (PDE) stimulator, imidazole, and a PDE inhibitor, aminophylline, were studied in rats. Imidazole caused an impairment of OGTT but not IVGTT. Aminophylline caused a rise in cAMP levels of liver, muscle, and adipose tissue, whereas imidazole did not alter the cAMP levels in these tissues. It is concluded that the in vitro effect of imidazole is not manifest in vivo and the differing effects of the drug observed during the two routes of glucose administration can be explained better by interference with absorption of glucose through the GI tract rather than alteration of tissue cAMP levels.

This study was supported in part by USPHS Grant No. AM16341. The authors are grateful to M. Ezekiel and S. Wilkins for their expert technical assistance.

A lag period of 12-24 hr has frequently been observed to elapse between charcoal hemoperfusion therapy and arousal of patients in stage IV coma due to fulminant hepatic failure. This delay suggests that recovery of consciousness depends on depletion of an extravascular pool of a hypothetical toxin which requires 12-24 hr to equilibrate with plasma. No further definitive information about the nature of the toxin is available. Unconjugated biliru-bin is known to have an extrahepatic, extra-vascular pool which also equilibrates with plasma over a 12- to 24-hr period. Accordingly, a model of unconjugated bilirubin kinetics has been used to investigate the rate of depletion of slowly equilibrating extra-vascular metabolic compartments by hemoperfusion, employing computer simulation techniques. The results indicate that the rate of depletion of slowly equilibrating extravascular pools is critically dependent not merely on the intrinsic efficiency of the hemoperfusion device, but also on the schedule with which it is employed. The conventionally employed regimen of 4-hr of treatment per day is relatively inefficient in achieving depletion of such compartments. These data imply, by analogy, that alternative hemoperfusion regimens, employing longer initial perfusion or perfusions at intervals of approximately 12 hr, would be more effective than current schedules in awakening patients with acute hepatic coma.

The author is indebted to Ms. P. Cromwell for assistance with this study and for preparation of the manuscript.

In an attempt to induce nonfa-tal rabies infection, five cats and five skunks were inoculated intraperitoneally with low-passage rabies virus. Three of the skunks died of acute fulminant rabies. Only one of the cats showed any evidence of illness. The affected cat developed hind limb paresis, coarse tremors, and irritability 11 days after inoculation of the virus and survived the apparent infection with nondisabling sequelae. High rabies virus neutralizing antibody (RVNA) titers were found in the serum and cerebrospinal fluid several weeks after the onset of illness and declined subsequently, as is common in abortive rabies encephalitis. However, after the 16th week, RVNA titers in both fluids again rose, and in the ensuing year and a half very high levels of antibodies were achieved. At about 120 weeks, the clinical condition worsened, and 6 weeks later the cat was sacrificed. At necropsy, lesions found in the central nervous system were not those of classical acute rabies, but consisted of an extensive chronic destructive encephalitis. Virus could not be isolated, probably because of the coexisting high antibody level. The observations are interpreted as consistent with a chronic re-crudescent form of rabies encephalitis.

Lipid composition and histology of brain samples from crinkled and non-crinkled mice fed a normal diet were studied. Sulfatides in young and cerebrosides in adults were found to be increased in brains from crinkled mice when compared to their noncrinkled controls. Cholesterol esters, not present at all in the controls, were found in all crinkled brains analyzed. Histological examination of brain showed abnormalities in myelin structures of varying degrees of severity in all brains from crinkled mice. The observation of cholesterol esters in the brains of crinkled mutants supports the view that the myelin disruption found in these mice is secondary to axonal degeneration.

This work was supported in part by Grant No. HD-02355 from the National Institute of Child Health and Human Development.

p-(Dipropylsulfamyl)benzoic acid (probenecid) has been utilized in clinical practice and in experimental studies to decrease the tubular reabsorption of uric acid ( 1 ). Probenecid is also known to inhibit the secretion of organic acids in the kidney ( 2 ). Despite the extensive use of this agent, its separate effects on the urate reabsorptive and secretory processes have not been examined by direct techniques. The current investigations, therefore, were designed to examine the effects of probenecid on net urate transport, urate reabsorption, and urate secretion using clearance, microinjection, and precession techniques in the rat.

Methods. Male Sprague-Dawley rats anesthetized with Inactin (Promonta, Hamburg, Germany), 100 mg/kg body wt intra-peritoneally, were used for all studies. Probenecid was dissolved in a solution of dilute NaOH to a final concentration of 10-20 mg/ml and was administered in a dose of 100 mg/kg body wt/hr intravenously. In control animals and in control periods of the clearance experiments, diluent alone was infused.

Clearance studies. After a tracheotomy, cannulae were placed in two jugular veins, in a femoral artery, and in the urinary bladder. Body temperature was maintained at 37°. Five percent mannitol in isotonic saline was infused at a rate of 12 ml/hr to match the protocol of the microinjection studies. Through the other venous line, normal saline containing [methoxy-³H]inulin (25 μCi/ ml) was infused at a rate of 1.2 ml/hr. After 60-90 min of equilibration, two control urine samples, 20 min each, were collected. One milliliter of blood was obtained from the femoral artery at the midpoint of each period and was replaced with the same volume of blood from a donor rat. Following collection of control samples, probenecid (100 mg/kg body wt/hr) was infused.

Guinea pigs made resistant to porcine relaxin by repeated injections were able to complete gestation and give birth to pups weighing the same as control animals. The progression of pelvic relaxation as gestation proceeded was retarded in the resistant animals although the optimum degree of relaxation was achieved just prior to parturition. Estrogen-primed, resistant animals responded to progesterone to the same extent as did controls, suggesting that the delay in pelvic relaxation during gestation is unlikely to be due to a reduction in secretion of relaxin or to a loss of tissue sensitivity to relaxin but rather to neutralization of pla-cental relaxin by circulating antibodies.

Note added in proof. Dr. B. G. Steinetz, of Ciba-Geigy Corporation, Ardsley, N.Y., has demonstrated the existence of anti-porcine relaxin antibodies in the sera of the relaxin-resistant animals used in these experiments. The antibody content was measured by the ability of the serum specifically to bind ¹²⁵I-poly-tyrosyl relaxin. Of the labeled relaxin added, 14 and 12%, respectively, was bound by 25 μl of serum from animals in groups II and III (Table I); the fraction bound by the same quantity of serum from control animals averaged less than 2%.

This study was undertaken to help determine whether or not the reaction of interferon with cells which leads to the rapid induction of the antiviral state (a) is initiated by the first binding of interferon to cells and (b) continues to occur after removal of the interferon. Experiments measuring the binding of interferon to cells over 15 min at 0 and 37° and the development of resistance showed that there was no significant difference between the amount of interferon bound to the cells at the two temperatures, but the rate of development of resistance was slowed if the initial binding occurred at 0°. This indicated that cell-bound interferon alone could not account for the rapidly developing resistance since equal amounts of interferon were bound at 0° and 37° but the rates of development of resistance were different. Experiments employing different volumes of medium for elution of interferon bound to cells at 0 or 37° showed that the eluting volume influenced the development of resistance in cells initially exposed to interferon at 0° but not in cells initially exposed at 37°. This indicated that the eluting interferon did not play a role in the rapid development after initial reaction at 37° as it does after initial reaction at 0°. The failure of antibody to inter-feron to prevent the development of resistance after brief reaction of interferon with cells at 37° indicates that the continued presence of cell membrane-bound interferon is not required for development of this resistance. The present findings when taken together with previous findings indicate that a brief temperature-dependent interaction between interferon and human cells initiates one or more cellular processes which no longer requires the presence of interferon and leads 30 min later to the derepression of the cistron which controls the development of the antiviral state.

In order to study the time relationship and role of dopamine (DA) in feedback inhibition of prolactin (PRL) by PRL, (a), ovine PRL (oPRL) (4 mg/kg) was given to male rats 1,4, and 12 hr before restraint stress; and (b) oPRL was given together with pimozide (2 mg/kg), a specific dopami-nergic receptor blocker. Four hours after injection of oPRL, basal levels of serum rat PRL were significantly reduced. Restraint stress elevated serum PRL levels about tenfold; pretreatment with ovine PRL prevented about 50% of this rise when given 4 hr but not 1 or 12 hr prior to stress. Blockade of dopamine receptors by administration of pimozide produced a six-fold rise in serum prolactin levels by 2 and 4 hr after injection. o-PRL given in combination with pimozide blocked only 25% (p ⋍ 0.05) of the increase of endogenous PRL by pimozide at 2 and 4 h. These observations suggest that (a) the “short-loop” inhibitory feedback on PRL release requires more than 1 but less than 4 hr to become active, and (b) a dopaminergic mechanism is mainly responsible for inhibition of PRL release by PRL.

We are grateful to Dr. Allen Tucker, Department of Dairy Science, Michigan State University, for performing the ovine PRL radioimmunoassays.

Cell-mediated cytotoxic activity in circulating mononuclear cells from patients with recurrent herpes simplex virus (HSV) infections with types 1 and 2 was examined employing target cells acutely infected with HSV in a ⁵¹Cr-release assay. Cytotoxicity was determined both when lesions were present and when lesions were absent in otherwise normal patients and was compared to levels of cytotoxicity in sero-positive individuals without histories of recurrences. When lesions were present, patients with recurrences had significantly higher levels of cytotoxicity than when lesions were absent. In the absence of lesions, cytotoxicity in patients with recurrences was not significantly different from levels in sero-positive individuals without recurrences. These patterns of cytotoxicity were observed in patients with both HSV-1 and HSV-2 infections. These studies indicate that patients with recurrent HSV infections have intact cell-mediated immune responses, as measured by this assay; and that although the levels of response vary with activity of the underlying infection, the responses are equal to or greater than those observed in sero-positive individuals without recurrences.

Little information on the pathophysiology of rhinovirus infection of the respiratory tract is available. The mechanisms by which the symptoms associated with rhinoviral colds are produced and the events which initiate recovery from colds are not known. Since human rhinoviruses do not grow in subprimates, a practical animal model for studying rhinoviral disease is unavailable. Organ culture, an alternative system, has been tried using human fetal tissue 1 2 3 4 but this material is in short supply. The behavior of bovine rhinoviruses has been studied in bovine tracheal organ cultures by Reed and Boyde 5 .

This report describes the development of an organ culture system for growing rhinoviruses in human nasal polyps which are readily available from elective polypectomies. The technique provides a means for studying rhinovirus pathogenesis in human tissue.

Materials and methods. Cultures of nasal polyp fragments. Nasal polyps from patients undergoing elective polypectomy were placed in Hanks' balanced salt solution (HBSS) containing penicillin (100 units/ ml), streptomycin (100 μg/ml), and myco-statin (50 μg/ml) for transport to the laboratory. Within 24 hr of removal, polyps were rinsed with two changes of HBSS, and the mucosa was cut into small pieces approximately 2 mm on a side. Three to five fragments were placed in a screw-capped tube containing 1.0 ml of Leibowitz (L-15) medium [Grand Island Biological Company, Grand Island, New York] with 10% fetal calf serum, 100 units of penicillin, 100 μg of streptomycin, and 50 μg of mycostatin/ml. Tubes were incubated at 34° in a roller drum turning at 10 revolutions/hr. Medium was changed every 3 days until the fragments were infected or used in an experiment as a control.

Fragments which were floating in the medium were examined microscopically at 48 hr for evidence of ciliary motion on the surface.

The effects of five human body fluids on human fibroblast interferon (MSF-IC) and human leukocyte interferon (WBC-NDV) are reported. After 24 hr at body temperature, WBC-NDV is significantly more stable than MSF-IC in cerebrospinal fluid, saliva, and serum. After 4 hr at 37°, leukocyte interferon is significantly more stable in urine and appears more stable in bile. These findings may be useful in the choice of an exogenous human interferon for clinical studies.

This work was supported in part by Grant No. 05-041-012 from the National Aeronautics and Space Administration and by Public Health Service Grant No. TO1 AI00466 from the National Institute of Allergy and Infectious Diseases.

Suspensions of PMN isolated from milk and S. aureus were incubated together at different ratios and with different types and concentrations of mammary fluids. Results showed that greater numbers of S. aureus were left unphagocytosed and alive within PMN at the higher S. au-reus: PMN ratios (2:1) than at the lower ratios. This effect was more noticeable in whole milk than in skimmed milk. Phagocytosis and destruction of S. aureus by PMN (ratio 1:10) were reduced (p < 0.01) to a greater extent in whole milk or in skimmed milk containing 10% cream than in either skimmed milk or whey. There was no difference between skimmed milk or whey. Increasing the concentration of either whole milk or skimmed milk in the incubation mixture from 10 to 40% resulted in fewer (p < 0.01) S. aureus phagocytosed but had no affect on intracellular kill. The data show that the milk fat globule is a major deterrent to the phagocytosis and destruction of S. aureus by PMN. Casein inhibited phagocytosis, but only when the concentration of skimmed milk in the incubation medium was increased to 40%. Casein did not affect intracellular kill.

We thank Jane Hawes for technical assistance.

The possible stimulatory, inhibitory, or absent effect of antral perfusion with ethanol on gastric acid secretion and transmucosal potential difference was studied using an in vivo chambered fundic segment and isolated antral pouch preparation with intact blood supply. The preparation was proven responsive to exogenous gastrin with pentagastrin iv infusion (6 μg/kg-hr) and to endogenous gastrin with acetylcho-line chloride (0.5%) and glycine (1 M) perfusion of the antral pouch. Peripheral venous serum gastrin concentration increased in response to antral perfusion with glycine with a slight increase in fundic acid secretion. A small increase in peripheral serum gastrin without a corresponding increase in acid output occurred during antral perfusion with 20% ethanol. No significant differences were found in either potential difference or acid output between saline and ethanol groups, or between histamine and histamine-plus-ethanol groups. These data suggest that ethanol-stimulated antral gastrin release is insufficient to stimulate or potentiate gastric acid secretion during acute conditions in the anesthetized dog.

We are greatly indebted to Dr. L. R. Johnson for his advice and for the measurements of serum gastrin. The technical assistance of Ms. Merle Stone, Mr. Thomas Ma, and Ms. Yuh-Jyh Kuo is appreciated.

These investigations were supported by NIH Grant No. 2 R01 AA-00194-05. Dr. Shanbour is the recipient of Research Scientist Development Award 5 K02-AA-70463-04.

TSH was determined by ra-dioimmunoassay in serum and milk of euthyroid, hyperthyroid, and thyroidecto-mized lactating rats. In the normal euthy-roid rats, the average serum TSH concentration was 219 ± 39.8 ng/ml, while the average concentration in milk was 156 ± 9.8 ng/ ml. Five to seven days after thyroidectomy both values were significantly increased to 892 ± 109 and 230 ± 6.5 ng/ml, respectively. In animals treated with a very large dose of T₃ for 4 days, serum and milk TSH concentrations were conspicuously decreased to 72 ± 7.1 and 63 ± 6.7 ng/ml, respectively.

Antibody synthesis was decreased in mice fed 1, 5, or 10 ppm methyl-mercury for 10 weeks. The primary immune response was significantly suppressed, while the secondary response was impaired but not significantly. These results indicate that methylmercury affects the B-cell or plasma-cell synthesis of IgM antibody.

Intra-arterial infusion of hista-mine results in dose-related increases in RBF, while GFR remains constant, resulting in progressive decrease in FF. Renal extraction of PAH (E _pah) decreased reciprocally with RBF, possibly a result of enhanced plasma flow rates. MABP remained quite stable. Increase in minute urine volume (V _u), and fractional clearance (fC) of Na⁺, K⁺, Ca²⁺, and osmality appeared to be related to the increments in blood flow, while simultaneous decrements in fT ^c _h20 and U/P_Osm occurred. The physical factors hypothesis could account for the observed changes in urine volume and electrolyte clearance, but other factors must also be considered, such as loss of nephron-concen-trating ability because of washout of the gradient of osmolality, a possible direct effect of histamine on the collecting duct H₂O permeability, or inhibition of ADH action.

This investigation was supported by National Science Foundation Grant PCM 76-04368. We are indebted to Dr. Myron H. Weinberger, Specialized Center of Research in Hypertension (Grant HL-14159), Indiana University School of Medicine, for assistance.

Studies were initiated in mice to develop a model of cell-mediated immunity to murine cytomegalovirus (MCMV). Immune interferon was produced in response to MCMV antigens in cultures of splenic lymphocytes from mice infected 7, 10, and 14 days previously. However, there was no lymphocyte transformation as measured by antigen-specific enhancement of [ 3 H]thymidine uptake. Lymphocyte transformation in response to phytohemaggluti-nin (PHA) was transiently suppressed in lymphocytes of MCMV-infected mice.

This study was conducted during the senior author's (MWR) sabbatical at the Laboratory of Oral Medicine, NIDR, NIH, Bethesda, Maryland. He wishes to thank Dr. Abner L. Notkins, Chief of the Laboratory of Oral Medicine, for his help with the study and his constructive criticism of the manuscript.

This study was carried out using 30 adult female rhesus monkeys in order to determine the effects of daily administration of ketamine HC1 (8-10 mg/kg) upon menstrual cycle length, incidence of ovula-tory menstrual cycles, and blood estrogen and progesterone levels throughout the cycle. In physically restrained control monkeys (25 cycles subjected to daily blood sampling) there were 14 of 25 or 56% ovu-latory cycles, and in ketamine-treated monkeys (32 menstrual cycles subjected to daily blood sampling) there were 28 of 32 or 88% ovulatory cycles. The length of the menstrual cycle was the same in both groups. The levels and time course of peripheral serum estrogen and progesterone levels were the same in the ovulatory cycles of both groups. In some of the control cycles (30%) and in some of the ketamine-treated cycles (25%) there were luteal phases in which the preovulatory estrogen levels were normal and in which the luteal-phase progesterone levels were low and variable 6-8 days after the preovulatory surge. It can be concluded that the daily use of ketamine HC1 does not significantly alter menstrual cycle length, or serum estrogen or progesterone levels throughout the menstrual cycle. It reduced the incidence of anovulatory cycles and premature menstrual induction probably by reducing the stress of restraining the monkey for the purpose of taking a blood sample.

This research was supported by Research Grants HD-03315 and HD-08834 from the National Institute of Child Health and Human Development, USPHS, and by a contract from the World Health Organization.