Prenatal hypoxia, habituation memory and oxidative stress.

Hypoxia-ischemia (HI) is characterized by a reduced supply of oxygen during pregnancy, which leads to both central nervous system and peripheral injuries in the foetus, resulting in impairment in its development. The purpose of this study was to investigate behavioural changes and systemic oxidative stress in adult animals that have been affected by HI during pregnancy. HI was induced by the occlusion of the maternal uterine artery with aneurysm clamps for a period of 45 min on the 18th gestational day. Animals from the sham group were submitted to same surgical procedure as the HI animals, without occlusion of the maternal uterine artery. The control group consisted of non-manipulated healthy animals. At postnatal day 90, the pups were submitted to behavioural tests followed by blood collection. HI adult animals presented an increase in anxiety behaviour and a lack of habituation compared to both sham and control groups. Oxidative damage, assessed by protein and lipid oxidation in serum, did not differ between HI and sham-operated animals. However, HI animals presented reduced activity of the glutathione peroxidase enzyme and increased formation of nitrite, indicating alterations in the systemic antioxidant repair system. Our results suggest an association among HI, systemic oxidative stress and behavioural alterations.

How REM sleep deprivation and amantadine affects male rat sexual behavior.

There are conflicting findings about the sexual effects of REM sleep deprivation (REMd). Otherwise, several studies show a dopaminergic hypersensitivity after REMd. The effect of REMd and amantadine (AMA) was studied for standard measures and temporal patterning in the first experiment, in four groups: normal with vehicle, normal with AMA (5.0 and 10 mg/kg), REMd with vehicle and REMd with AMA (5.0 and 10.0 mg/kg). REMd reduced mount latency (ML), intromission latency (IL) and mount number (MN) and increased copulatory efficiency (CE) and hit rate factor. REMd also reduced the mount bout number (MBN) and increased the sexual interaction (mount bout time, MBT) among male and female during copula. AMA stimulates initiation and hit rate factors and accelerates the temporal patterning of sexual behavior, evoking fewer and quicker mount bouts. In the experiments with combination of REMd and AMA administration, AMA did not increase behavior effects evoked by REM deprivation, probably due to a top or a bottom effect, depending on the measures considered. A second experiment studied the effects of AMA (1.25 to 5.0 mg/kg) and REMd on the sexual reflexes of nonimmobilized male rats. REMd enhanced the AMA effects upon the seminal emission reflex, but inhibited the penile erection reflex elicited by 1.25 mg/kg of AMA. Curiously, our results showed that REMd, like AMA, a dopaminergic agonist, causes similar effects of sexual behavior in the male rat, particularly those related to arousal mechanism and hit rate factor. The results are discussed and the effects of REMd probably involve dopaminergic hypersensitivity and increased sexual motivational response.

Rotavirus excretion in naturally infected pigs with and without diarrhoea.

Seven hundred and fifty faecal samples from piglets ranging from 1 to 60 days old were studied for the presence of group A rotavirus by polyacrylamide gel electrophoresis (PAGE) and by enzyme immunoassay (EIA). From 451 diarrhoeic pigs, 117 (25.94%) were positive for rotavirus and only 45 (15.05%) of 299 pigs without diarrhoea excreted the virus (P < 0.005). When these animals were separated into four age groups with regard to the presence or absence of diarrhoea, it was observed that the excretion of rotavirus was associated with diarrhoea in piglets, both before and after weaning.

Teste de coaglutinaçäo para detecçäo de rotavirus / Coagglutination assay for detection of rotaviruses

Resumo: O teste de coaglutinaçäo foi utilizado para a detecçäo de rotavírus em fezes de origem humana e de suínos. Suspensäo de Staphylococcus aureos, produtor de proteina A, foi sensibilizada com uma diluiçäo seriada de antissoro anti-rotavirus do grupo A mostrando que quando foi utilizada a diluiçäo a 1:20, o teste foi capaz de detectar tanto antígeno SA11 como também o extrato fecal, ambos diluídos. Um total de 89 amostras de fezes absorvidas com S. aureus foram testadas por coaglutinaçäo e por um ensaio imunoenzimático. A análise estatística dos resultados obtidos mostrou uma concordância de 0,91 entre os dois testes o que levou-nos a conluir que a coaglutinaçäo é um método simples, rápido, sensível e pouco dispendioso para a detecçäo de rotavírus diretamente do material fecal. Além da utilizaçäo do soro diluído para a sensibilizaçäo de s> aureus ficou demonstrado também que, esta mistura, quando estocada a 4 graus C pode ser utilizada por até 6 meses após o seu preparo, sem implicar em resultados falso-positivos (au)

Viruses with bisegmented double-stranded RNA in pig faeces.

Viruses similar to the bisegmented double-stranded (ds) RNA picobirnaviruses described in human faeces and the intestinal contents of Oryzomys nigripes rats and guinea pigs were isolated from the faeces of pigs taken from several areas in the state of Sao Paulo, Brazil. Samples were collected from 912 pigs of several breeds, aged nine to 61 days, and assayed by polyacrylamide gel electrophoresis with silver staining and a combined enzyme immunoassay for rotavirus and adenovirus, using the simian rotavirus SA11 as control. Electrophoretic profiles resembling the bisegmented dsRNA viruses were detected in 106 pigs with 15.3 per cent occurring in animals with diarrhoea compared to 9.6 per cent in animals without diarrhoea.

Presence of group A and non-A rotaviruses in neonatal piglets in Campinas, SP, Brazil.

Rotaviruses were detected by polyacrylamide gel electrophoresis (PAGE) in 11 (84.6%) of 13 faecal specimens from neonatal piglets with acute diarrhoea in a piggery near the city of Campinas, State of São Paulo, Brazil. An immunoenzimatic assay for group A rotavirus (IEA-A) was positive in ten of the samples, all of which showed a PAGE profile typical of that group. Another sample was showed a group B profile in PAGE. An immunoenzimatic assay specific for group B (IEA-B) for this faecal sample was positive, confirming the PAGE results.