Hepatitis E virus infection in buffaloes in South China / [Hepatite E infecção viral em búfalos no Sul da China]

Hepatitis E virus (HEV) infection is an important global public health issue. HEV infections are recognized as a zoonotic disease. Swine are believed to be the main reservoir of HEV. Recently, yaks, cows, and yellow cattle have been reported as new reservoirs of HEV. However, whether other species of cattle and buffaloes are sensitive to HEV infection is unknown. To investigate the prevalence of HEV infection in buffaloes, enzyme-linked immunosorbent assay (ELISA) and reverse transcription-nested polymerase chain reaction (RT-nPCR) were performed. Only one buffalo was positive to anti-HEV IgM antibody (1/106, 0.94%), and none were positive for anti-HEV IgG antibody. To our surprise, five serum (5/106, 4.72%) and three milk samples (3/40, 7.50%) from buffaloes were positive to HEV RNA. All strains of HEV isolated from buffaloes belong to genotype 4. Results indicate that buffaloes may be a new reservoir of HEV.(AU)

Infecção com o vírus Hepatite E (HEV) é uma importante questão de saúde pública global. Infecções HEV são reconhecidas como doença zoológica. Acredita-se que suínos são o principal reservatório de HEV. Recentemente iaques, vacas, e gado amarelo foram reportados como novos reservatórios do HEV. Porém, não se sabe se outras espécies de gado e búfalo são sensíveis a infecção HEV. Para investigar a prevalência de infecção HEV em búfalos, foram realizados prova de imunoabsorção enzimática e polimerização em cadeia inversa ancorada em transcrição. Apenas um búfalo foi positivo para o anticorpo anti-HEV IgM (1/106, 0,94%), e nenhum foi positivo para o anticorpo anti-HEV IgG. Para nossa surpresa cinco (5/106, 4,72%) e três amostras de leite (3/40, 7,50%) de búfalos foram positivos para HEV RNA. Todas as estirpes de HEV isoladas de búfalos pertencem ao genótipo 4. Resultados indicam que búfalos podem ser um reservatório de HEV.(AU)

The role of nitric oxide in reproduction

Nitric oxide (NO) plays a crucial role in reproduction at every level in the organism. In the brain, it activates the release of luteinizing hormone-releasing hormone (LHRH). The axons of the LHRH neurons project to the mating centers in the brain stem and by afferent pathways evoke the lordosis reflex in female rats. In males, there is activation of NOergic terminals that release NO in the corpora cavernosa penis to induce erection by generation of cyclic guanosine monophosphate (cGMP). NO also activates the release of LHRH which reaches the pituitary and activates the release of gonadotropins by activating neural NO synthase (nNOS) in the pituitary gland. In the gonad, NO plays an important role in inducing ovulation and in causing luteolysis, whereas in the reproductive tract, it relaxes uterine muscle via cGMP and constricts it via prostaglandins (PG).