RESUMO
Programmes for the eradication and control of infections with bovine viral diarrhea virus (BVDV) concentrate on the identification and elimination of persistently infected (PI) animals. The identification of these animals is mainly based on the detection of viral antigen using ELISA techniques. Protocols detecting viral nucleic acid using RT-PCR have been described recently. Due to high costs the German model recommends screening of animals of 9 up to 36 months of age. Screening of bulk milk samples using RT-PCR technology would allow a system independent of age. The aim of the present study was to test whether bulk milk samples (1433 including max. 50 animals each) collected in four counties of Lower Saxony are suitable for a complementary identification of PI animals via RT-PCR. Thirty-one bulk milk samples derived from 27 dairy herds were BVDV positive, corresponding to 2.3 % of the herds analysed in this study. Two samples first scored doubtful. Follow up tests revealed lactating PI animals in most cases (18). In other cases the epidemiological status of the herd, i.e. high sero-prevalence and/or presence of PI animals among non-lactating cattle, suggested a transient infection detected in the first bulk milk sample. These results demonstrate that monitoring of lactating cattle of any age using RT-PCR is a very sensitive, economically effective additional method for the identification of PI animals.
Assuntos
Doença das Mucosas por Vírus da Diarreia Viral Bovina/diagnóstico , Vírus da Diarreia Viral Bovina/isolamento & purificação , Leite/virologia , RNA Viral/análise , Reação em Cadeia da Polimerase Via Transcriptase Reversa/veterinária , Animais , Doença das Mucosas por Vírus da Diarreia Viral Bovina/epidemiologia , Bovinos , Vírus da Diarreia Viral Bovina/genética , Feminino , Alemanha/epidemiologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Sensibilidade e EspecificidadeRESUMO
The LC5 isolate of Little cherry virus (LChV-LC5) is one of at least two distinct viruses contributing to a severe disease of cherry (Little cherry disease [LChD]) in British Columbia. A near-complete nucleotide sequence of LChV-LC5 is available as well as polyclonal antibodies against LChV-LC5 coat protein produced in bacterial cells. A survey for LChV-LC5-infected trees in the Okanagan Valley and Kootenay region of British Columbia was carried out using enzyme-linked immunosorbent assays (ELISA) and LChV-LC5 antibodies. Reverse transcriptase polymerase chain reaction (RT-PCR) and sequence analysis of four different regions of the genomes of 31 of these isolates have been conducted. A high level of sequence variability was found: nucleotide sequence divergence between LChV-LC5 and the other sequenced isolates ranged from 0 to 19.7%, and amino acid sequence divergence ranged from 0 to 9.1%. Further examination of RT-PCR and sequence data identified six discrete groups of isolates, including a group identical to LChV-LC5. The high level of divergence in LChV-LC5 isolates occurring in British Columbia suggests that caution should be used in the selection of methods used for diagnosis during surveys for this virus.
RESUMO
The long-term efficacy of combined insulin-glibenclamide treatment was investigated in 79 secondary drug failure patients by means of a double-blind, randomized placebo-controlled study. During a one-year follow-up period the patients on insulin plus glibenclamide required significantly lower exogenous insulin doses. Coincidentally, C-peptide concentrations were significantly raised in the verum versus the placebo group. Additionally, the administration of glibenclamide resulted in a decreased level of hyperglycaemia during the first six months of the observation period. Glibenclamide withdrawal after six and again after twelve months of the combined therapy provoked a deterioration of glycaemic control, as well as a lowering of the C-peptide concentrations. The findings demonstrate a prolonged beneficial effect of the combined treatment, in contrast to the solely short-term effects predicted by numerous studies. The metabolic improvement must be ascribed in part to the beta-cytotropic effect of glibenclamide. Extrapancreatic pathways via receptor/postreceptor mechanisms cannot be excluded.