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41.
Summary;To investigate the distribution of possible novel mutations from parkin gene in variant sub-set of patients with Parkinson’s disease(PD)in China and explore whether parkin gene plays an im-portant role in the pathogenesis of PD,70 patients were divided into early-onset group and late-onsetgroup; 70 healthy subjects were included as controls.Genomic DNA from 70 normal controls andfrom those of PD patients were extracted from peripheral blood leukocytes by using standard proce-dures.Mutations of parkin gene(exon 1—12)in all the subjects were screened by PCR-single strandconformation polymorphism(SSCP),and further sequencing was performed in tue samples with ab-normal SSCP results,in order to confirm the mutation and its location.A new missense mutationGly284Arg in a patient and 3 abnormal bands in SSCP electrophoresis from samples of another 3 pa-tients were found.All the DNA variants were sourced from the samples of the patients with early-on-set PD.It was concluded that Parkin point mutation a  相似文献   
42.
The HACCP (hazard analysis critical control point) concept is now widely applied in the food industry and provides a structured and critical approach to the identification and control of hazards that may affect food safety. It has shifted the emphasis for control from retrospective end-product testing to the effective control of raw materials and key processing operations.
This paper discusses how the HACCP approach can be applied to enteral feeding. This involves each unit assembling a multidisciplinary team of personnel involved in enteral feeding. This team will then carry out a detailed analysis of the process from selection of ingredients and feeding systems through to consumption of the feed by the patient by constructing a flow chart that relates specifically to each unit. They can then identify and assess the hazards associated with the handling of the product at each stage in the process. This will enable them to identify the points where control over an identified hazard can be achieved (critical control points, CCP) such as quality of ingredients, design of administration systems, preparation and distribution of the feeds and the procedures involved in the assembly and manipulation of the systems. Control and monitoring procedures can then be specified and implemented at relevant stages in the process. The major strengths of the HACCP procedure are that it entails a team effort from key personnel involved in the full range of activities associated with the product and each detailed analysis is specific to each unit's practices and resources and can be continually reviewed and modified in response to changing circumstances.  相似文献   
43.
本文通过对228例各种类型胃粘膜上皮异型增生的病理切片的复查,发现并详细地描述了不同类型异型增生腺管和上皮细胞癌变的初发点(Start point)。其形态有的是从再生腺管的腺颈部或底部以“发芽”形式,向质内浸润并分枝生长;有的是从再生腺管基底膜向侧方的间质浸润。从再生的胃上皮型异型腺管所出现的癌变多为低分化型腺癌;从肠上皮型异型腺管所发生的癌变则为高分化型腺癌。强调了胃粘膜再生性异型增生有些具有癌前性质。  相似文献   
44.
应用聚合酶链反应(PCR)方法扩增苯丙氨酸羟化酶(PAH)基因的每个外显子及其侧翼的内含子,并克隆到M 13载体中进行序列分析。发现中国人苯丙酮尿症(Phenylketonuria,PKU)患者的PAH基因外显子3中有1个Arg~(111)→Ter~(111)的点突变,此突变与东方人最常见的突变单体型4呈连锁不平衡。此突变占中国人PAH等位基因的10%左右,但不存在于高加索人群中,表明在种族分化过程中PAH基因位点发生了互不相关的突变事件。  相似文献   
45.
A parallel-plate dissolution cell is introduced as a method to study the effect of pores on the dissolution rate of a tablet surface.By measuring the dissolution rate of a smooth surface under various flow conditions it is confirmed that the experimental behaviour of the cell complies with hydrodynamic theory. The value of the diffusion coefficient calculated from these results is equal to the one found in a previous rotating disk study.The critical pore diameter that is obtained from dissolution experiments with porous surfaces in the cell is in full agreement with the value predicted on basis of the results with the rotating disk technique and the theoretically calculated friction velocity at the surfaces of the parallel-plate dissolution cell.  相似文献   
46.
Miconazole and econazole, two fungicide imidazole derivatives, completely inhibited growth of Trypanosoma cruzi (Tulahuen strain) at concentrations of about 20 muM. Culturing of T. cruzi in the presence of lower doses of imidazole derivatives produced: decrease of 5,7-diene sterol content in epimastigotes (including ergosterol); disappearance of the nuclear chromatin, vacuolization and decrease in the electron density of the cytoplasm; selective surface alterations as revealed by an increased response to wheat-germ- and phytohemagglutinin. At variance with the effect of miconazole on Candida (De Nollin et al. (1977) Antimicrobial. Agents Chemother. 11, 500-513), miconazole and econazole, under the experimental conditions used, did not increase the rate of hydrogen peroxide generation by T. cruzi.  相似文献   
47.
Summary To investigate the distribution of possible novel mutations from parkin gene in variant subset of patients with Parkinson’s disease (PD) in China and explore whether parkin gene plays an important role in the pathogenesis of PD, 70 patients were divided into early-onset group and late-onset group; 70 healthy subjects were included as controls. Genomic DNA from 70 normal controls and from those of PD patients were extracted from peripheral blood leukocytes by using standard procedures. Mutations of parkin gene (exon 1–12) in all the subjects were screened by PCR-single strand conformation polymorphism (SSCP), and further sequencing was performed in the samples with abnormal SSCP results, in order to confirm the mutation and its location. A new missense mutation Gly284Arg in a patient and 3 abnormal bands in SSCP electrophoresis from samples of another 3 patients were found. All the DNA variants were sourced from the samples of the patients with early-onset PD. It was concluded that Parkin point mutation also partially contributes to the development of early-onset Parkinson’s disease in Chinese. WANG Tao, male, born in 1961, Associate Professor This work was supported by grants from the key program of the special scientific project of Scientific & Technologic Agency of Hubei Province (Serial No. 2001AA308B01) and the Hygienic Research Project of Hygienic Agency of Hubei province (Serial No. WJ 01529).  相似文献   
48.
The reduction of the quinone moiety, which is found in many anti-cancer agents, is still a poorly understood process. It is commonly assumed that the reduction of a quinone by the uptake of two electrons and two protons leads to the active hydroquinone form. For a better understanding of these reactions electrochemical data, obtained for a series of substituted benzoquinones, were analyzed. In addition quantum chemical calculations on the STO-3G level were performed to obtain data for the one- and two-electron reduction.From the electrochemical experiments, thermodynamic data can be obtained which show that the unfavourable free energy of electron uptake is overcome by the favourable binding of protons. Both reactions are influenced by the electronic properties of the substituents, as demonstrated by Hammett-type relationships between the free energy of these reactions and the sigma-para character of these substituents. In these relationships the reaction constant of the electron uptake process has an absolute value which is five times higher than that of the proton uptake.Quantum chemical calculations yielded energy values for the one-electron uptake, as expressed by U(LUMO), and for the total reduction process. Most of the results from these calculations are in accord with the thermodynamic study. The calculations also revealed a conformational change to take place upon reduction of NH2 and N(CH2)2 substituted benzoquinones, which might be important for chemical and biological activity.  相似文献   
49.
应用视觉近点测定评价纺织厂不同作业工人的视疲劳。检查了32名修布工人和38名验布工人。同一工厂的33名保育员作对照组。结果表明:视觉近点的测定指标比调查受试者主诉的眼视觉症状更为敏感。修布和验布组在工作后,作业者的视觉近点比上班前明显变远,但时照蛆工作前后无明显变化。三组视觉近点比较,发现修布和验布组视觉近点的变化。提示由修布和验布作业引起的视觉疲劳,可以通过测定视觉近点来进行评价。  相似文献   
50.
应用X衍射方法测定雷公藤两个化合物的晶体结构,并对影响固体熔点的结构因素进行分析。晶型(或空间对称群)、结晶溶剂、分子间作用力及分子构象的精细变化均可导致晶态物质的熔点变化。  相似文献   
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