Controversial significance of early S100B levels after cardiac surgery

BACKGROUND: The brain-derived protein S100B has been shown to be a useful marker of brain injury of different etiologies. Cognitive dysfunction after cardiac surgery using cardiopulmonary bypass has been reported to occur in up to 70% of patients. In this study we tried to evaluate S100B as a marker for cognitive dysfunction after coronary bypass surgery with cardiopulmonary bypass in a model where the inflow of S100B from shed mediastinal blood was corrected for. METHODS: 56 patients scheduled for coronary artery bypass grafting underwent prospective neuropsychological testing. The test scores were standardized and an impairment index was constructed. S100B was sampled at the end of surgery, hourly for the first 6 hours, and then 8, 10, 15, 24 and 48 hours after surgery. None of the patients received autotransfusion. RESULTS: In simple linear analysis, no significant relation was found between S100B levels and neuropsychological outcome. In a backwards stepwise regression analysis the three variables, S100B levels at the end of cardiopulmonary bypass, S100B levels 1 hour later and the age of the patients were found to explain part of the neuropsychological deterioration (r = 0.49, p < 0.005). CONCLUSIONS: In this study we found that S100B levels 1 hour after surgery seem to be the most informative. Our attempt to control the increased levels of S100B caused by contamination from the surgical field did not yield different results. We conclude that the clinical value of S100B as a predictive measurement of postoperative cognitive dysfunction after cardiac surgery is limited

The role of apolipoprotein E in cognitive decline and delirium after bypass heart operations

Cognitive decline and delirium are common complications after heart bypass surgery. Based on the reported role of the APOE-epsilon 4 allele in neurodegenerative diseases, we studied its association with these complications. A neuropsychological test battery consisting of the Mini Mental State Examination, the Wechsler's Memory Scale Revised, the Brief Psychiatric Rating Scale, and the Delirium Rating Scale was applied to 137 APOE-genotyped patients on admission and 1 month after bypass surgery. We correlated the APOE (apolipoprotein E) polymorphism with the postoperative test outcome by taking into account all factors known to influence cognitive capacity after heart surgery. There was a significant decline in all test results 1 month after surgery and a high frequency of postoperative delirium. Neither this decline nor the frequency of delirium was associated with the APOE-epsilon 4 allele. This study confirms the high incidence of cognitive decline and delirium after coronary surgery, but it does not support the role of the APOE-epsilon 4 allele in the occurrence of these complications

Efeito da inclusão de polpa cítrica peletizada na confecção de silagem de capim-elefante (Pennisetum purpureum, Schum.) Effect of pelleted citrus pulp inclusion on elephantgrass (Pennisetum purpureum, Schum.) ensiling

Objetivou-se com esta pesquisa avaliar os efeitos da idade de corte do capim-elefante cv. Napier (Pennisetum purpureum Schum.) e da inclusão da polpa sobre a qualidade fermentativa e a estabilidade aeróbia da silagem, além de elaborar um índice de recomendação da inclusão de polpa cítrica, em função do teor de umidade do capim, para reduzir os custos com esta tecnologia. Foram confeccionados silos de laboratório (capacidade de 6 litros) e testados 20 tratamentos (quatro repetições), correspondentes a cinco idades de crescimento do capim (40, 60, 80, 100 ou 120 dias após corte de nivelamento) e quatro níveis de inclusão de polpa cítrica peletizada (0, 3, 6 ou 9%, com base na matéria natural do capim), em arranjo fatorial 5 x 4. Houve efeito da interação idade de corte &times; nível de polpa sobre as concentrações de ácidos acético, propiônico, butírico e lático, a relação lático/acético, o pH, o nitrogênio amoniacal e a temperatura máxima, mas não para a concentração de álcool, a digestibilidade in vitro da MS, o tempo para atingir a temperatura máxima, a taxa para elevação da temperatura e o tempo para elevação da temperatura em 2ºC. A inclusão de polpa melhorou o perfil fermentativo das silagens, com efeito mais pronunciado em silagens produzidas com capins mais novos. Com base no teor de ácido acético e em derivações da equação de superfície gerada, foi possível obter a recomendação de inclusão de 0,7% de polpa cítrica (com base na matéria natural do capim) para cada unidade percentual de MS que o capim possuir abaixo de 32. Portanto, o nível ótimo de inclusão de polpa que otimiza a qualidade da silagem é igual a (32 - MS) x 0,7.<br>The objectives of this trial were to evaluate the effects of regrowth age of elephantgrass (Pennisetum purpureum Schum. cv. Napier), and citrus pulp addition on the fermentation pattern and aerobic stability of their silage. In addition to that, this research also aimed to create a recommendation index of citrus pulp addition taking into account the moisture concentration of the grass, in order to decrease costs of technology adoption. Laboratory silos (6 L-capacity each) were used and 20 treatments were tested, corresponding to 5 different grass regrowth ages (40, 60, 80, 100, or 120 days after harvesting) and four levels of citrus pulp pellets (0, 3, 6, or 9%, based on grass fresh matter) in a factorial arrangement 5 x 4, with four replicates. Regrowth age and citrus pulp addition level interacted for acetic, propionic, butyric, and lactic acid concentrations, lactic/acetic acid ratio, pH, ammoniacal nitrogen, and maximum temperature, but did not for alcohol concentration, in vitro DM digestibility, time to achieve the maximum temperature, rate for increasing temperature, and time for increasing temperature in 2ºC. In general, the addition of citrus pulp improved fermentation pattern of silages, with greater effect when silages were produced with high moisture grasses. Based on acetic acid concentration and using derivations from the surface equation, it was possible to recommend the addition of 0.7% of citrus pulp (based on grass fresh matter) for each percentage unit of grass DM lower than 32%. Therefore, the optimum addition level of citrus pulp which optimizes silage quality is equal to (32 - DM) x 0.7