Sex differences in the play fighting activity of golden hamster infants.

Play fighting of homosexual and heterosexual dyads in golden hamsters was studied. The behaviors of male-male (MM), female-female (FF), and female-male (FM) dyads were recorded from the 25th to the 31st day of age. Play fighting activity of heterosexual dyads was depressed since MF and FM dyads exhibited a significantly high physical contact time and engaged in less play fighting, with a significantly lower time spent on such activity.

Normal intraocular pressure in children.

The age-related trend values and the normal intraocular pressure (IOP) increase curve from birth through the 16th year of life were studied in 460 subjects with a noncontact tonometer (Keeler Pulsair, Keeler, Ltd, Windsor, Berks, UK). Much lower values than in adults were recorded in subjects up to the age of 3 or 4 years. This finding leads us to believe that in the treatment of infantile glaucoma IOP should be kept within the age physiologic levels, in an attempt to prevent visual field loss and optic atrophy.

Epikeratophakia: histopathological and cultural study.

Three epikeratoplasty buttons (one aphakic and two myopic) prepared by the freeze technique were removed two to nineteen months after surgery. A complete morphological and immunohistochemical study was performed on these buttons in order to gain insight into the reasons for epikeratophakia failure. Histopathological studies with light microscopy and scanning and transmission electron microscopy were performed.

Voluntary intake of "Tiquira", an alcoholic beverage prepared from fermented manioc, decreases immunoglobulin production and increases self-reactivity in mice.

Unlabelled: We studied the effects of chronic voluntary ingestion of "Tiquira" (50%)--an alcoholic beverage prepared from fermented manioc, widely consumed in Maranhão,--on the natural immunological activity of young adult (2-3 months old) C57B1/6J mice (16-17 g) by evaluating the number of plaque-forming cells (PFCs) in the spleen and by titrating serum antibodies by ELISA. Voluntary ingestion of "Tiquira" for 30 days decreased immunoglobulin secretion in serum (

Control: 1600 +/- 30 vs

Experimental: 193 +/- 20), caused an impressive reduction in the total number of PFCs in the spleen (

Control: 482 +/- 22 vs

Experimental: 58 +/- 3) and increased the proportion of self-reacting antibody molecules in serum (

Control: 119 +/- 16 vs

Experimental: 800 +/- 20) and self-reactive PFCs to mouse red blood cells (MRBC) in the spleen (

Control: 183 +/- 14 vs

Experimental: 272 +/- 16; N = 10 animals per group). These preliminary results suggest that the voluntary ingestion of "Tiquira" for 30 days may interfere with immunological relations by decreasing the total number of immunoglobulin secreting cells and increasing the anti-self antibody production.

Nitric oxide generation from nitroprusside by vascular tissue. Evidence that reduction of the nitroprusside anion and cyanide loss are required.

Nitric oxide (NO) was produced from sodium nitroprusside in the presence of vascular tissue but was not released spontaneously from the nitroprusside anion. In the absence of tissue in the dark nitroprusside did not release NO. When solutions of nitroprusside alone were irradiated with visible light, nitric oxide was released at rates linearly proportional to nitroprusside concentration and light intensity.

Testicular function in active ankylosing spondylitis. Therapeutic response to human chorionic gonadotrophin.

Testicular function was studied in 22 patients with ankylosing spondylitis (AS) with serum measurements of hormone levels, seminal fluid analysis and testicular reserve test. Results were correlated with disease activity. The abnormal findings were elevated luteinizing hormone (LH), inversion of estradiol/testosterone ratio (E2:T) and diminished testicular reserve for testosterone (T) and slightly increased for estradiol (E2).

Role of the endothelium in modulation of the acetylcholine vasoconstrictor response in porcine coronary microvessels.

Study Objective: The aim was to investigate the role of the endothelium in modulating the acetylcholine response in porcine coronary microvessels and compare the results with simultaneously studied large coronary arteries.

Design: Coronary microvessels [104 (SEM 3.3) microns; range 38-150] were removed from fresh porcine hearts and studied in vitro during no flow constant pressure conditions.

Specific antibodies in mouse milk after ovalbumin ingestion.

C57B1/6J mice received ovalbumin (Ova) orally, 20 mg/day, from day of parturition for 3, 5, 7, 10 or 15 days. Anti-Ova antibodies were titrated in plasma and milk by passive hemagglutination, and Ova-specific plaque-forming cells (PFC) were counted in the spleen and mesenteric lymph nodes. Anti-Ova antibodies in milk and antibody-secreting cells in mesenteric lymph nodes and spleen were detected on day 3, increased on day 5 and peaked on day 10.

Diet-induced atherosclerosis increases the release of nitrogen oxides from rabbit aorta.

We examined the hypothesis that impaired endothelium-dependent vasodilation in atherosclerosis is associated with decreased synthesis of nitrogen oxides by the vascular endothelium. The descending thoracic aortae of rabbits fed either normal diet, a high cholesterol diet for 2-5 wk (hypercholesterolemic, HC), or a high cholesterol diet for 6 mo (atherosclerotic, AS) were perfused in a bioassay organ chamber with physiologic buffer containing indomethacin. Despite a dramatic impairment in the vasodilator activity of endothelium-dependent relaxing factor (EDRF) released from both HC and AS aortae (assessed by bioassay), the release of nitrogen oxides (measured by chemiluminescence) from these vessels was not reduced, but markedly increased compared to NL.

Comparative analysis of the neck region in spermatids and spermatozoa of some orthopteran insects.

The ultrastructure of the neck region and the participation of noncovalent and disulphide bonds in the head-tail attachment were analyzed in spermatids and spermatozoa of some orthopteran species from the families Tettigoniidae and Acrididae. This study combined conventional electron microscopy with cytochemical procedures to detect acidic proteins and lysine-rich basic proteins, and with treatments using the disruptive agents sodium dodecyl sulfate (SDS) and dithiothreitol (DTT). The organization of the neck region differs in spermatozoa among species in the families analyzed.

Vasorelaxant properties of the endothelium-derived relaxing factor more closely resemble S-nitrosocysteine than nitric oxide.

Studies of cultured bovine aortic endothelial cells using quantitative chemiluminescence techniques have shown that the amount of nitric oxide released under basal conditions, or in response to either bradykinin or the calcium ionophore A23187 is insufficient to account for the vasorelaxant activities of the endothelium-derived relaxing factor (EDRF) derived from the same source. This observation contradicts previous suggestions that nitric oxide and EDRF are the same compound, but may be explained if EDRF is a compound that contains nitric oxide within its structure but is a much more potent vasodilator than nitric oxide. Such a molecule could be one of several nitrosothiols which may yield nitric oxide after a one-electron reduction.

Increased resistance against oxidative stress is observed during a short period of renal reperfusion after a temporal ischaemia.

Reperfusion of rat kidney submitted to temporal ischaemia induces a decrease in glutathione content. Lipid peroxidation is not detected in kidney homogenates but microsomes obtained after periods of reperfusion longer than 60 minutes show increased malondialdehyde values correlated with high oxygen consumption and superoxide free radical generation. Microsomes obtained from kidneys submitted to 15 or 60 minutes of reperfusion are resistant to NADPH-induced lipid peroxidation but after 120 minutes of reperfusion an increased lipid peroxidative response is observed.

Isolation and characterization of the gene encoding phosphoenolpyruvate carboxykinase from Saccharomyces cerevisiae.

The yeast PCK1 gene coding for phosphoenolpyruvate carboxykinase (PEPCK) was isolated by functional complementation of pck1 strains from S. cerevisiae. Only one copy of the gene was found per haploid yeast genome.

Effects of blindness on play fighting in golden hamster infants.

The effects of bilateral optic enucleation on play fighting in golden hamster infants were studied. The behaviors of blind-blind (BB), blind-intact (BI) and intact-intact (II) dyads were recorded from the 30th to the 36th day of age. It has been noted that the differences in physical contact, play fighting and grooming time, as well as in the percentage of time spent in play fighting, the amount of locomotion and other activities of BB, BI and II were small and statistically insignificant.

Selectivity of silymarin on the increase of the glutathione content in different tissues of the rat.

Silymarin, a flavonoid extracted from the seeds of the milk thistle, Silybum marianum, increases the redox state and the total glutathione content of the liver, intestine, and stomach of the rat. The same treatment does not affect the levels of the tripeptides in the kidney, lung, and spleen. This selective effect of the flavonoid on the digestive organs is ascribed to its pharmacokinetics on the digestive track, where the biliary concentration of silymarin is increased and maintained via the entero-hepatic circulation.

Silybin dihemisuccinate protects against glutathione depletion and lipid peroxidation induced by acetaminophen on rat liver.

Acetaminophen hepatotoxicity is characterized by glutathione depletion, cellular necrosis, and, in some instances, by the induction of lipid peroxidation. Silybin dihemisuccinate, a soluble form of the flavonoid silymarin, protects rats against liver glutathione depletion and lipid peroxidation induced by acute acetaminophen intoxication. Other biochemical parameters such as serum transaminases did not show the drastic increase observed under acetaminophen intoxication when animals were treated with the flavonoid.

Ingestion of high doses of fish oil increases the susceptibility of cellular membranes to the induction of oxidative stress.

Feeding rats with 4 g/kg body weight of sardine oil during 7 or 14 days increases the content of eicosapentaenoic acid and docosahexaenoic acid in the erythrocyte and hepatic microsomal membranes by 2 to 6%. These membranes show increased susceptibility to the induction of oxidative stress, expressed as lipid peroxidation, when they are exposed to Fe2+-ascorbate and to NADPH-FE3+-ADP, respectively. The results indicate that in order to prevent the increased susceptibility to lipid peroxidation, supplementation with larger amounts of antioxidants may be needed than those required to stabilize the oil.

Characteristics of canine coronary resistance arteries: importance of endothelium.

Canine coronary resistance vessels were studied in vitro to examine the role of the endothelium in modulating responses to acetylcholine, vasopressin, and thrombin and to compare these responses to those found in large epicardial vessels. Acetylcholine had no effect on passively distended microvessels; however, after preconstriction with the thromboxane analogue, U 46619 caused dose-dependent vasodilation [50% effective concentration (EC50), 0.05 microM; maximum response, 97.

[Infections by anaerobes in children: frequency of isolation and antimicrobial resistance].

We studied the frequency of isolation and antimicrobial susceptibility of strict anaerobic bacteria isolated in a paediatric hospital. A total of 1,753 samples from purulent material and hemocultures were processed. One hundred and thirty strains were isolated from 95 children: 44 from 48 cases of peritonitis (91.

Effect of silybin dihemisuccinate on the ethanol metabolizing systems of the rat liver.

Silybin dihemisuccinate produces a decrease in the ethanol metabolic rate of rats. This effect is ascribed to an inhibition of the microsomal ethanol oxidizing system (MEOS). Alcohol dehydrogenase activity, catalase activity and NADPH cytochrome c reductase activity are not affected by the flavonoid.

Release of NO and EDRF from cultured bovine aortic endothelial cells.

The endothelium-derived relaxing factor (EDRF) has recently been reported to be nitric oxide. This study was performed to determine whether the vasorelaxant activity of EDRF could be accounted for by nitric oxide released from cultured endothelial cells. Nitric oxide released from cultured bovine aortic endothelial cells was monitored using a chemiluminescence technique with and without reflux processing of the effluent with a strong reducing environment (1% sodium iodide in glacial acetic acid).

Mechanisms of abnormal endothelium-dependent vascular relaxation in atherosclerosis: implications for altered autocrine and paracrine functions of EDRF.

The present studies were performed to determine if abnormal endothelium-dependent vascular relaxation in atherosclerosis is due to decreased production or release of endothelium-derived relaxing factor (EDRF) by atherosclerotic rabbit vessels or if atherosclerotic vessels are less sensitive to the relaxing effects of EDRF. EDRF release was quantified using two approaches, by the response of bioassay detector vessels and also by the activation of guanylate cyclase within cultured endothelial cells. Using these assays, atherosclerotic vessels were found to release significantly less EDRF than normal vessels in response to both receptor- and nonreceptor-mediated stimuli.

Regulation of yeast fructose-1,6-bisphosphatase in strains containing multicopy plasmids coding for this enzyme.

The structural gene for yeast fructose-1,6-bisphosphatase (FbPase) has been cloned by complementation of a strain carrying the fbp1-1 mutation and lacking FbPase activity. By Northern analysis it could be shown that the fbp1-1 mutation does not interfere with the transcription of the gene although no normal active enzyme is produced. Strains transformed with the cloned gene on a multicopy plasmid overproduce FbPase but are still subject to strong catabolite repression.