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The southwestern corn borer, Diatraea grandiosella Dyar, is a major pest of corn, Zea mays L., in the southern United States. To search for plant allelochemicals, chemically defined insect diets are commonly used, but southwestern corn borer larvae did not grow and develop unless a subnutritional amount of wheat germ was incorporated in the amino acid diet. Fractionation led to identification of hemicellulose as the active component which was then characterized. The hemicellulose permitted insect growth on a protein-free amino acid diet. Microfloral involvement was ruled out because larvae grew and developed free of intestinal microbes. Therefore, this insect has an absolute requirement for hemicellulose that has evidently not been demonstrated with other invertebrates or vertebrates. This finding is of general interest because hitherto, the contributions of hemicellulose to nutrition have generally been considered to be associated chiefly with microfloral conversion to assimilable carbohydrates. Investigations should be conducted to determine whether hemicelluloses are also important or essential for growth of vertebrates including mammals by mechanisms that may not have been considered.  相似文献   
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Decreased serum cholesterol has been associated with impulsive aggressive behaviors. This study was designed to explore the relationship between serum cholesterol levels and measures of impulsive aggression in personality disordered patients. Forty-two personality disordered patients (14 borderline personality disorder, 28 other personality disorders) were included. Fasting serum cholesterol was measured by standard enzymatic assay. An ANOVA was performed with factors of gender and diagnosis, looking at two-way interactions between the factors and serum cholesterol. Patients with borderline personality disorder were found to have significantly lower serum cholesterol than non-borderline personality disorders. A significant interaction effect was also seen between gender and diagnosis with the male patients having lower cholesterol levels. This study suggests there may be a relationship between borderline personality disorder and low serum cholesterol.  相似文献   
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Two domains of anosognosia in Alzheimer''s disease.   总被引:5,自引:1,他引:4       下载免费PDF全文
OBJECTIVE: To examine the presence of different dimensions of unawareness in patients with probable Alzheimer's disease. METHODS: A consecutive series of 170 patients with probable Alzheimer's disease were assessed with the anosognosia questionnaire-dementia (AQ-D) which includes items related to cognitive deficits and behavioural problems. RESULTS: A factor analysis of the AQ-D produced two factors: a "cognitive unawareness" factor, which loaded on items of memory, spatial and temporal orientation, calculation, abstract reasoning, and praxis, and a "behavioural unawareness" factor which loaded on items of irritability, selfishness, inappropriate emotional display, and instinctive disinhibition. A stepwise forward regression analysis showed significant correlations between the cognitive unawareness factor and more severe cognitive deficits, delusions, and apathy, but less depression. On the other hand, the behavioural unawareness factor correlated significantly with higher mania and pathological laughing scores. Whereas the cognitive unawareness factor showed a significant correlation with cognitive tests assessing verbal comprehension and long term memory, and was significantly associated with a longer duration of illness, no significant correlations were found between the behavioural unawareness factor and the neuropsychological tasks. CONCLUSION: Unawareness of cognitive deficits and unawareness of behavioural problems may constitute independent phenomena in Alzheimer's disease. Whereas unawareness of cognitive deficits is related to the severity of intellectual impairment and the presence of delusional apathetic mood, unawareness of behavioural problems may be part of a disinhibition syndrome.  相似文献   
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The authors report a study in which 109 cerebrospinal fluid (CSF) specimens from patients with varying neurological disorders were incubated in tissue culture medium for 1, 3, and sometimes 7 days. Strict criteria for malignancy were applied to cells found at these intervals. In 35 patients with verified central nervous system neoplasms, eight cases had malignant cells and 11 others had "doubtful" cells by tissue-culture analysis. Thirty-three of these cases were also examined with standard millipore cytological techniques: six had malignant cells and four had "doubtful" cells. Of 50 cases with inflammatory or other non-neoplastic conditions, cells were cultured in 13. None was considered malignant by our criteria. Tissue culture of CSF has several potential benefits. Even with stringent criteria, it is possible to demonstrate the presence of unequivocally malignant cells in CSF by tissue culture. The systemic application of such criteria may eventually increase the positive identification of malignancies. Further, since these cells are growing, the degree of malignancy may be more accurately determined by a study of growth in culture. Such a study could not be done by conventional methods. Finally, tissue culture can help to guide therapy in certain instances in which a surgical biopsy cannot be obtained.  相似文献   
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