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991.
To investigate further the possible role of mutant hepatitis B viruses in the pathogenesis of fulminant hepatitis B, the genomic sequence of hepatitis B virus isolates from 9 South African blacks with this disease, including 5 entire genomes, was analysed. Seven of the isolates were genotype A. The mutation most often reported in patients with fulminant hepatitis B, the G1896A precore stop-codon substitution, was, as expected, not present in the genotype A isolates with the exception of one in which it was accompanied by a compensatory C1858T substitution. G1896A was, however, present in the one genotype D isolate. No other precore-defective mutants were detected. The other mutation commonly found in patients with fulminant hepatitis B, the paired A1762T, G1764A substitution in the basic core promoter, was present in only one patient and G1764A in one other. The pre-surface initiation-codon mutation documented in a number of patients with fulminant hepatitis B was not found in our isolates. An 18-amino acid deletion present in the pre-surface region of one isolate has not previously been described in fulminant hepatitis B. Variations within the surface region were mainly genotype specific and not previously described. A relatively large number of mutations were present in the middle region of the core gene in those isolates without G1896A or A1762T, G1764A mutations, although the pattern was not consistent with those in published studies. Thus, as in other published series in which the entire genome of hepatitis B virus responsible for fulminant hepatitis was sequenced, we detected many mutations in different genes, but none was common to all the reported isolates.  相似文献   
992.
一起学校流感暴发的调查和分析   总被引:1,自引:0,他引:1  
目的调查此次疫情暴发的原因和特点,防止类似疫情再次发生。方法按2005年广东省卫生厅《广东省流感样病例暴发疫情报告及调查处理工作指引(试行)》进行。结果全校学生902人,发病74例,罹患率为8.20%。整个疫情流行过程为17日,7—9岁年龄组发病较多,男女发病无显著差别。一、二年级学生和在校午休学生罹患率较高,具明显的班级和宿舍聚集性;病毒分离培养为B型流感病毒。结论此次为一起由B型流感病毒引起的流感暴发疫情,暴发原因为未及时隔离治疗病人、疫情报告迟缓、室内通风换气不够和学校未开展流感疫苗接种等。  相似文献   
993.
To determine hepatitis B virus genotype and subtype distribution among HBV infected individuals with different clinical manifestations in western India, serum samples from 19 asymptomatic hepatitis B surface antigen carriers, 30 chronic hepatitis B patients, 8 acute hepatitis B patients, 5 fulminant hepatitis B patients, and with circulating HBV DNA were genotyped and subtyped on the basis of the nucleotide sequence analysis of S region of the HBV genome. Genotype D was the predominant genotype circulating in western India (57/62; 91.93%). All 19 asymptomatic hepatitis B surface antigen carriers, 8 acute hepatitis B patients, 5 fulminant hepatic failure patients and 25/30 chronic hepatitis B patients were circulating genotype D and ayw3/ayw2 subtypes. HBV genotype A was prevalent in 8% (5/62) of the total number of patients and all belonged to chronic hepatitis B category. Subtyping analysis showed that all genotype A isolates were of subtype adw2. As most of the patients from different clinical categories were infected with HBV genotype D, it is concluded that this genotype did not influence the outcome of HBV infection.  相似文献   
994.
995.
996.
Electrogastrogram is a surface measurement of gastric myoelectrical activity, and electrogastrography has been an attractive method for physiological and pathophysiological studies of the stomach due to its nonivasive nature. Motion artifacts, however, ruin the electrogastrogram (EGG), and make the analysis very difficult and sometimes even impossible. They must be eliminated from EGG signals before analysis. Up to now, this can only be done by visual inspection, which is not only time-consuming but also subjective. In this study, a method using feature analysis and neural networks has been developed to realize automatic detection and elimination of the motion artifacts in EGG recordings by computer. Experiments were conducted to investigate the characteristics of different motion artifacts. Useful features were extracted, and different combinations of the features used as the input of the neural network were compared to obtain the optimal performance for the detection of motion artifacts using the artificial neural network.  相似文献   
997.
The chronological changes in the gene expression for three species of cytosolic fatty acid-binding proteins (FABPs) in the rat brain were examined by Northern and in situ hybridization analyses. The expression for heart(H)-FABP became evident after birth, with a gradual increase and confined to the gray matter, suggesting that the expression of H-FABP mRNA is neuron-specific in postnatal brain. The expression for brain(B)-FABP was very intense in the ventricular germinal zone, without expression in the cerebellar external granule cell layer, suggesting the dominant expression in the cells of glial lineage. B-FABP mRNA was transiently expressed in perinatal gray as well as white matter and the expression in glial cells persists only in the olfactory nerve fiber layer at the adult stage. On the other hand, the expression for skin type(S)-FABP was evident in the both ventricular germinal zone and cerebellar external granule cell layer, suggesting the expression in cells of neuronal lineage. The expression for S-FABP was evident in the prenatal gray matter and S-FABP mRNA was expressed in glial cells at early postnatal stage, whereafter the expression decreased to, but remained at weak levels in the adult brain. Discrete functions of the three FABPs were suggested in neurons and glia differentially at various developmental stages.  相似文献   
998.
The long arm of chromosome 11 is one of the most interesting regions in the search for major genes involved in the etiology of manic-depressive illness. Several candidate genes have been identified, including the gene encoding the dopamine D2 receptor, the M1 muscarinic receptor, and porfobillinogen deaminase. Furthermore, different families with co-segregation of psychiatric illness and structural chromosome abnormalities involving regions 11q21, 11q22.3, and 11q25 have been reported. Using narrow as well as broad phenotypic models, conservative genetic parameters, models with dominant or recessive modes of inheritance, and various methods to reduce misclassification, the present study did not find evidence for a major gene causing manic-depressive illness on the long arm of chromosome 11. In the broader phenotypic models multi-point analyses excluded at least 11q14 to 11q23.3, approximately 60 cM, even in one large family. Assuming homogeneity close linkage to DRD2 was excluded for all dominant models, and also in the affecteds-only analyses in the large family alone. © 1995 Wiley-Liss, Inc.  相似文献   
999.
All-night sleep EEG and auditory evoked responses (AERs) were recorded in 8 children whose ages ranged from 27 to 60 months. EEG intensity was measured by means of a Drohocki-type integrator. Two measures of evoked response amplitude were calculated: the peak-to-peak amplitude of the P2N2 component, and a multiple-component amplitude measure of the first 500 msec of the response. Both amplitude measurements were found to correlate well with each other. Changes in EEG intensity between subjects were not correlated with changes in AER amplitude, but a number of correlations between AER amplitude and EEG intensity were found within individual subjects. Further analysis suggested the latter finding might be a result of the presence of “unaveraged’EEG in individual AER plots. It is concluded that little correlation exists between AER amplitude and EEG intensity in children during sleep.  相似文献   
1000.
A negative relationship between platelet monoamine oxidase (MAO) activity and Sensation Seeking (SS) has been reported in several studies. This study evaluates the possible contribution of autonomic nervous system (ANS) activity to this relationship. Additionally, confirmatory factor analysis was used to create models of ANS concepts from a larger number of psychophysiological variables. Skin conductance (SC) and heart rate (HR) were recorded from 46 men and 49 women during a two-session protocol that included rest periods, a balloon stress, a series of tones, and two tasks: two-flash threshold and tachistoscopic recognition. Results showed that the best-fitting models for both rest and task periods included concepts of SC base levels (“arousal”), SC lability, and HR, and were quite similar for men and women. MAO activity correlated positively with SC concepts, most strongly for women. Women showed negative relationships between sensation seeking and both SC arousal and HR concepts. In contrast, men showed evidence of positive relationships between SC concepts and an active life style. The sex differences and response specificity in these relationships make it unlikely that ANS activity mediates the negative MAO-SS relationship.  相似文献   
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