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21.
The recent epidemiological trends of human leptospirosis in Italy were investigated using data collected for the years 1981–1985. A total of 626 hospitalized patients with clinical diagnoses of suspected leptospirosis were reported by hospital centers from several Italian regions. Epidemiological, clinical and seroimmunological data were collected in 517 of these cases and examined by the National Center for Leptospirosis.Serological findings in 33.5% of these subjects met the criteria for confirmation of the disease. In 21.8% of the subjects, low titer antibodies were detected, which possibly reflected previous leptospiral infections. An early antibiotic treatment of the current infection may also have lowered the seroimmunological response in some of these patients.In 59.3% of the confirmed cases, modes of transmission were allotted equally between accidental events and recreational or occupational activities. Drinking water from an open air fountain emerged as an uncommon mode of transmission; it was responsible for an outbreak of 33 cases of leptospirosis. In another 37.07% of the subjects, it was impossible to establish the mode of transmission.Respiratory or influenza-like symptoms were the only clinical signs of illness in 21.2% of the patients with confirmed leptospirosis.In comparison to the sixties and seventies, the prevalence of infecting serovars showed increasing incidence of infections due to serovars of the Javanica (11.0%) and Australis (11.0%) serogroups and an important decrease in the Bataviae serogroup infections (from 58.8% in rice-field workers in the forties to 0.6% in the years 1981–1985). Sejroe serogroup infections accounted for 4.5 per cent of confirmed cases of leptospirosis.In 49.7% of subjects with confirmed leptospirosis, cross-agglutination at the same titre with two or more serovars of different sero-groups occurred, thus preventing the identification of the serogroup of the infecting strain.  相似文献   
22.
乌鲁木齐市家蝇抗药性现状及发展趋势分析   总被引:2,自引:0,他引:2  
目的 分析乌鲁木齐市家蝇对化学杀虫剂的抗药性现状及发展趋势,探讨防制对策。方法 常规微量点滴法。结果 对溴氰菊酯的抗性系数在24.00-253.67;对敌敌畏的抗性系数在11.44-53.24;对二氯苯醚菊酯抗性系数在9.29-36.10,对氯氰菊酯的抗性系数在2.32-9.62。结论:8年来家蝇对4种杀虫剂的抗药性在不断上升,仍保持较高水平,但迅速上升的趋势开始减缓。  相似文献   
23.
论中医病因、致病因素、邪气、邪之关系   总被引:2,自引:0,他引:2  
邪是一切不正常、不正当的因素,邪气是邪的一部分,主要指六气异常以及疫疠之气等外感因素。两者可以独立于人体而存在,也可以进入人体,成为可能导致疾病的因素,即致病因素,邪(邪气)进入人体是致病因素,未进入人体不是致病因素。未导致疾痛的致病因素不是病因,已经引起疾病的致病因素是病因。  相似文献   
24.
This retrospective analysis reviews the clinical experience of a major urban referral hospital with diffuse malignant pleural mesothelioma during the 14-year period from 1973 through 1986. Seventy-five cases of definite or equivocal mesothelioma were identified. There were four cases of primary malignant peritoneal mesothelioma, seven cases of benign fibrous mesothelioma, and 64 cases of diffuse malignant pleural mesothelioma. In 43 cases (67%) of diffuse malignant pleural mesothelioma, there was historic evidence of asbestos exposure. In 21 cases (33%), there was no known history of asbestos exposure. An increase in annual incidence of diffuse malignant pleural mesothelioma was observed over the study period, from three cases in 1973 to ten cases in 1986. Despite greater awareness of this disease, the diagnosis remains a difficult one to establish given the nonspecific symptoms, signs and radiographic appearance, variable histologic appearance, and poor diagnostic sensitivity and specificity of thoracentesis and closed pleural biopsy. Thoracotomy, thoracoscopy, and CT-guided needle biopsies gave higher yields and are the diagnostic measures of choice when diffuse malignant pleural mesothelioma is suspected.  相似文献   
25.
To investigate whether the secular trend for growth in Dutch children still exists, the Oosterwolde I study of 1980 was repeated in 1989. A persisting secular trend was visible for height while the z scores of body proportions show no change during the past 10 years, which suggests that there is no change in the timing of puberty.  相似文献   
26.
白城市52年间法定报告传染病流行趋势分析   总被引:1,自引:0,他引:1  
目的:了解掌握法定报告传染病流行情况及变化。方法:采用描述流行病学方法,分析报告传染病的消长分布。结果:传染病的发病率,死亡率,病死率都呈显著下降趋势,病种间消长有明显变化。结论:血源及性传播疾病为新时期的主要传染病病种。  相似文献   
27.
Kening Lu  Daoyi Xu  Zhichun Yang   《Neural networks》2006,19(10):1538-1549
We consider a class of Cohen–Grossberg neural networks with delays. We prove the existence and global asymptotic stability of an equilibrium point and estimate the region of existence. Furthermore, we show that the trajectories of the neural networks with positive initial data will stay in the positive region if the amplification function satisfies a divergent condition. We also establish the existence of a globally attracting compact set for more general networks. We estimate this compact set explicitly in terms of the network parameters from physiological and biological models. Our results can be applied to neural networks with a wide range of activation functions which are neither bounded nor globally Lipschitz continuous such as the Lotka–Volterra model. We also give some examples and simulations.  相似文献   
28.
29.
Fenfluramine, an amphetamine derivative used in the treatment of obesity, has been evaluated in vivo in the bone marrow cells of Swiss albino mice using two cytogenetic endpoints for assessing its genotoxic and clastogenic potentials. Concentrations of 0.75, 1.5, 3.0, and 5.0 mg/kg b.w. were administered orally for the study of sister chromatid exchange frequencies and chromosome aberrations (CA). SCE frequencies showed a positive dose response; 1.5 mg/kg being the minimum effective concentration. Fen caused a prolongation of cell cycle at all concentrations. Except for the minimum therapeutic dose (0.75 mg), all other doses (1.5, 3.0, and 5.0 mg) showed a significant increase in the percentage of damaged cells over that of the vehicle control. The degree of clastogenicity was directly proportional to the dosage used and inversely related with the duration of treatment. A gradual reduction of the clastogenic potential was observed after 12 and 24 hr of exposure, indicating that the maximum effect occurs at the middle or late synthetic phase of the cell cycle. This study, probably the first detailed screening of the drug for its genotoxicity, shows that Fen is moderately clastogenic and a DNA damaging agent in vivo.  相似文献   
30.
A longitudinal model based on the simplex model is presented to analyze simultaneously means and covariance structure using univariate longitudinal twin data. The objective of the model is to decompose the mean trend into components which can be attributed to those genetic and environmental factors which give rise to phenotypic individual differences and a component of unknown constitution which does not involve individual differences. Illustrations are given using simulated data and repeatedly measured weight obtained in a sample of 82 female twin pairs on six occasions.  相似文献   
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