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1.
The Charcot-Marie-Tooth disease type 1A (CMT1A) phenotype is most often associated with a 1.5 megabase (mb), tandem duplication of chromosome 17 band p12 (17p12). The prevailing hypothesis is that the demyelinating neuropathy results from a dosage effect of the peripheral myelin protein gene PMP22 which is included within this duplication. We present a patient with clinical and electrophysiological features of CMT1A in whom an extra PMP22 gene resulted from a rare unbalanced translocation of 17p to the X chromosome. This finding further supports the hypothesis of gene dosage as the basis for CMT1A. Moreover, this case highlights the importance of fluorescence in situ hybridization (FISH) as an alternative molecular technique in the diagnosis of CMT1A.  相似文献   

2.
A cross-over, single-blind clinical study was performed to compare a powered and a manual toothbrush for their ability to remove plaque from the teeth of pre-school children. Seventy-three randomly selected 4- to 6-year-old children from two kindergarten classes in Erfurt, Germany participated in the study. A new powered children's toothbrush (Rowenta) and a currently marketed manual children's toothbrush (Elmex) were used for an assessment period of two weeks each. Then the groups were crossed over to use the alternate toothbrush for another two weeks. Whole mouth, gingival margin and interproximal plaque area levels were determined using the Rustogi et al. plaque index. Statistical analysis of the data showed significantly effective (p < 0.05) plaque removal with both toothbrushes, immediately after toothbrushing and at one and two weeks, compared to the respective baseline scores. The statistical analysis also demonstrated that the powered toothbrush was significantly (p < 0.05) better on percent plaque reduction on all tooth areas compared to the manual toothbrush, except at two weeks with the interproximal assessment.  相似文献   

3.
OBJECTIVES: To determine persistence of bacteremia, pathogenicity, and immunoglobulin kinetics after blood transmission of Bartonella henselae in cats. ANIMALS: 18 specific-pathogen-free (SPF) cats (16 weeks old) received blood or urine from 4 adult cats (2 SPF, 2 naturally infected with B henselae). PROCEDURE: SPF cats were inoculated with blood IV (n = 4), blood IM (n = 4), or urine sediment IM (n = 4) from 2 bacteremic cats (donors A and B). Control cats (2/route) received inoculum from culture-negative, seronegative SPF cats (donors C and D). RESULTS: 6 cats (5 blood, 1 urine) were transiently febrile during the 213-day observation period. Two bacteremic cats developed CNS abnormalities. Transient anemia was the only hematologic abnormality. Bacteremia was induced in 7 of 8 blood recipients by postinoculation day (PID) 11. Urine recipients (n = 6) did not become bacteremic or seroconvert by PID 108, but when challenge exposed IV with blood, 4 of 6 became infected. All infected cats developed relapsing bacteremia. Initially, colony counts for donor-A recipients were 10(3) greater than those for donor-B recipients; however, during relapses, counts were similar. Polymerase chain reaction-restriction fragment length polymorphism analysis of 16S rRNA gene and the intergenic spacer region revealed no differences among isolates derived from recipient cats. Bartonella henselae-specific antibodies were detected between PID 15 and 18 in donor-A, compared with PID 46 and 181 in donor-B recipients. The peak geometric mean titer of donor-A recipients was 1,448, versus 406 for donor-B recipients. CONCLUSIONS AND CLINICAL RELEVANCE: Blood transmission of B henselae induced subtle clinical abnormalities; the biological behavior of the 2 donor strains differed; and relapsing bacteremia can persist in conjunction with variably high antibody titers.  相似文献   

4.
BACKGROUND: The study was carried out to evaluate the correlation between blood-retinal barrier (BRB) permeability and the progression of diabetic retinopathy (DR), defined by development of "need for photocoagulation", over a 7-year period by means of vitreous fluorometry (VF). METHODS: Forty type 2 diabetic patients with minimal or no retinopathy, aged 40-65 years (mean 53.9 + 7.3 years), were followed up prospectively for 7 years. Investigations including standard ophthalmological examination, fundus photography, fluorescein angiography and VF were performed at entry and 1, 4, 5 and 7 years later. Only one eye per patient was included in the study. Need for photocoagulation was based on Early Treatment Diabetic Retinopathy Study protocols and decided by the attending ophthalmologist. RESULTS: After 7 years of follow-up a total of 22 of the 40 eyes had received photocoagulation. The eyes that needed photocoagulation were those that had higher VF values at the entry of the study and showed higher rates of deterioration (initial values 5.1 + 1.9 vs 2.8 + 1.5 x 10(-6) min-1, P < 0.001; annual increase in leakage for the first year, 1.5 + 0.8 vs 0.5 + 1.0 x 10(-6) min-1, P < 0.001,). The eyes that did not need photocoagulation during the 7 years of follow-up showed stable VF readings (-0.1 + 1.2 x 10(-6) min-1, difference between initial values and 7 years later). CONCLUSIONS: Abnormally high VF values and their rapid increase over time are good indicators of progression and worsening of the retinopathy in diabetes type 2.  相似文献   

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6.
Modern leukocyte removal filters have been developed after years of refinement in design. Current filters are composite filters in which synthetic microfiber material is prepared as a nonwoven web. The filter material may be surface modified to alter surface tension or charge to improve performance. The housing design promotes effective contact of blood with the filter material and decreases shear forces. The exact mechanisms by which these filters remove leukocytes from blood components are uncertain, but likely represent a combination of both physical and biological processes whose contributions to leukocyte removal are interdependent. Small-pore microfiber webs result in barrier phenomena that permit retention of individual cells and increase the total adsorptive area of the filter. Modifications in surface charge can increase or decrease cell attraction to the fibers. Optimum interfacial surface tensions between blood cells, plasma, and filter fibers not only permit effective blood flow through small fiber pores, but also facilitate cell contact with the material. Barrier retention is a common mechanism for all modern leukocyte-removal filters and applies to all leukocyte subtypes. Because barrier retention does not depend on cell viability, it is operative for cells of any age and will retain any nondeformable cell, including whole nuclei from lymphocytes or monocytes. Barrier retention is supplemented by retention by adhesion. RBCs, lymphocytes, monocytes, granulocytes, and platelets differ in their relative adhesiveness to filter fibers. Different adhesive mechanisms are used in filters designed for RBCs compared with filters designed for platelets. Although lymphocytes, monocytes, and granulocytes can adhere directly to filter fibers, the biological mechanisms underlying cell adhesion may differ for these cell types. These differences may depend on expression of cell adhesion molecules. In the case of filtration of fresh RBCs, platelet-leukocyte interaction seems to supplement other mechanisms of leukocyte retention. The interactions of cells with biomaterials is an area of important research for implantable medical devices, artificial organs, and orthopedic, vascular, and dental prosthetics. Research in these areas is likely to contribute to improved biomaterials for blood filters. Improved techniques for the preparation of hybrid polymers and new techniques for surface modification of existing polymers will increase the technical opportunities for the development of synthetic surfaces ideally designed for leukocyte removal. It is therefore likely that the performance of leukocyte-removal filters will continue to improve. The development of cost-effective leukocyte removal filters specifically designed for use during component preparation would permit leukocyte depletion of all cellular blood components.  相似文献   

7.
Morphological changes in the neurons of the gerbil hippocampus following 5 min of forebrain ischemia were examined using light and electron microscopy. Although non-pyramidal neurons in the CA1 region of the hippocampus survived through the full length of the observation period, up to six weeks after ischemia, they consistently demonstrated degenerative changes distinct from those of the well-known "delayed neuronal death" of CA1 pyramidal cells. When examined with the light microscope, CA1 non-pyramidal neurons were found to be shrunken and their nuclei and cytoplasm were hyperchromatic between seven days and six weeks after ischemia. When examined with the electron microscope, postischemic non-pyramidal neurons were found to have markedly electron-dense profiles; their cytoplasm contained numerous free ribosomes and heterogeneous smaller granular substances, the latter also filling the nuclei. However, there was no loss of ribosomes from the rough endoplasmic reticulum, and mitochondrial cristae were preserved, suggesting that these neurons were viable. CA1 non-pyramidal neurons were studied immunohistochemically using three types of monoclonal antibodies, one each against parvalbumin, a nonphosphorylated epitope on the 168,000 mol. wt and 200,000 mol. wt subunits of neurofilament proteins, and microtubule-associated protein 2. CA1 non-pyramidal neurons lost immunoreactivity to these neuron-specific substances six weeks after ischemia, suggesting that these degenerating cells lacked certain types of normal neuronal activity. We conclude that non-pyramidal neurons in the hippocampal CA1 region survive transient ischemia but undergo degenerative changes following complete loss of CA1 pyramidal cells. These changes may be due to depletion of presumptive target-derived trophic factors within the non-pyramidal neurons.  相似文献   

8.
Plaque removing efficacy was compared between a new toothbrushing method named the Toothpick method and the Bass method. 20 male university dental students participated in the study, which consisted of 2 experiments. Prior to each experiment, all subjects were asked to abstain from all oral hygiene procedures for 48 h. In Exp. I, plaque-removing efficacy was assessed after each participant's mouth had been professionally brushed by a dentist. In this experiment, 2 quadrants were brushed professionally using the Toothpick method, and the remaining 2 quadrants were brushed using the Bass method. The brushing time amounted to a total of 2 min per mouth. In Exp. II, the subjects brushed their own teeth after receiving toothbrushing instruction. A blind examiner assessed dental plaque using a modification of the Quigley and Hein index at 6 sites around each tooth. Toothbrushing using the Toothpick method was found to remove significantly more plaque from proximal tooth surfaces than brushing using the Bass method.  相似文献   

9.
Examined links between 2nd language acquisition and acculturation and cultural identity in 102 Chinese students attending a Canadian university. Ss completed a questionnaire assessing attitudes and aspects of proficiency in English (PIE) and were assessed for oral PIE. A factor analysis of the relationships among these variables yielded 5 factors: linguistic identification, identification with another community, fear of assimilation, maintenance of the Chinese culture, and desire to learn English. Attitudinal variables and indices of ethnic identification related to aspects of PIE. While PIE was closely linked with a sense of identity, identification with the 2nd language community (and PIE) did not necessarily imply assimilation. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

10.
"On the basis of an analysis of 47 studies involving measures of the job proficiency of 2,462 workers employed in 39 different occupations, the average correlation between seniority and job proficiency is .17 with a standard error of correlation of .02. The type of measure of job success influences the relation between seniority and job success… [and]… the influence of seniority increases with the skill level of the occupations sampled… with skilled occupation the influence appears to be large relative to the magnitude of validity coefficients commonly obtained and should be taken into account and controlled whenever possible." (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

11.
用能力验证(包括测量审核和比对实验)进行检测项目的技术能力评估是实验室质量控制一种手段;国内外有许多标准和规范涉及能力验证结果的分析和评定,其中采用En数进行结果判断是一种基础方法。由于实际对象的复杂性,在采用En数进行结果判断时,一些情况往往被忽视,判断的合理性也需要关注;相关问题与测量测量不确定度的应用是联系在一起的。本文结合冶金检测的实例,说明采用En数进行结果判断应注意的问题,同时对实际检测中测量不确定度的应用的问题作一些分析和介绍,以期提供有益的思路。  相似文献   

12.
何芳 《包钢科技》2000,26(2):75-78
除尘设备的选型,采用宽极距、强电场来设计电除尘器,并对其内部组成进行优化。  相似文献   

13.
The prophylactic effect of intravenous immunoglobulin (GB-0998) on the recurrent acute otitis media, bronchitis and bronchopneumonia in IgG 2 deficient infants was investigated in a multicenter trial. GB-0998 was administered 6 times every 4 weeks. The doses were 300 mg/kg wt. during the first treatment, followed by 5 doses of 200 mg/kg wt. The results indicated that GB-0998 was effective in the prophylaxis of the recurrent infection of acute otitis media, bronchitis and bronchopneumonia in infancy with IgG 2 deficiency and/or IgG 2 antibody deficiency specific for Streptococcus pneumoniae.  相似文献   

14.
To characterize the long-term service performance and predict the lifetime of heat-resistant steel applications,more than 300 test pieces can be loaded simultaneously at Baosteel to determine the relationship between stress and rupture duration at specific temperatures. In addition,versatile testing methods have been established that evaluate creep-rupture,stress-relaxation,and creep-fatigue,as well as state-of-the-art tensile testing at hyper-high temperatures exceeding 2 100 ℃. Based on the Larson-M iller method,according to API 530,the accumulation of large volumes of data with respect to stress,temperature,and rupture time of actually tested steels ensures the reliability of predicting the allowable working stress over 100 000 h at any given temperature. For examples,the stress tendencies against rupture time of T/P91 and T/P92 steel tubes,as obtained by Baosteel,are consistent with those from NIMS and ECCC. As an accredited provider of the Proficiency Testing schemes in ISO/IEC 17025 and ISO/IEC 17043,Baosteel has periodically organized national proficiency testing with respect to creep and rupture,thereby providing an efficient way for all parties to assess their technical competence when performing uniaxial creep testing by the methods in ISO 204 and ASTM E139.  相似文献   

15.
为分析能力验证对实验室检测能力提升的促进方式,定量能力验证对实验室检测能力的提升效能,分析了305家实验室2010-2015年间参加柴油检测能力验证的3 133个评价结果和能力评价统计量|Z|值的变动趋势。研究表明,随参加能力验证次数增加,实验室检测能力显著提高,但单次能力验证不能有效保证持续检测能力。通过3轮能力验证,实验室能够基本消除检测过程中的关键错误。对于不同检测项目间能力验证的相互作用研究表明,通过参加某一项目的能力验证,实验室提高了其他项目的技术水平,表明能力验证能够促进实验室整体能力提升,而非局限于单一的检测项目。能力验证对实验室检测能力的作用方式可分为2种,一种通过消除检测技术的关键错误,直接提升能力验证参加项目的技术水平;另一种通过提升实验室整体管理能力,间接提升其他检测项目的技术水平。  相似文献   

16.
The effects of matte finish and modularity on loosening of tapered stems using the same cementing technique were studied prospectively. In 80 patients, 82 cemented Exeter primary stems were implanted at total hip revision by one surgeon using the same surgical and cementing technique throughout the series. The polished stems behaved differently than the matte surfaced stems behaved. Polished stems subsided in the cement mantle an average of 1 mm at 2 years after implantation, but without subsequent loosening of stems at as long as 12 years after implantation. Matte surfaced stems with metal centralizers had a higher loosening rate, and loss of fixation at the prosthesis to cement interface was identified as an early sign of loosening of these stems. At a mean 6-year followup, there were no revisions nor was there radiographic evidence of loosening of the polished modular stems. It is concluded that matte finish results in increased loosening of tapered stems but the introduction of modularity did not.  相似文献   

17.
A factor analysis of 46 tests (manipulative, printed, and physical performance) yielded fifteen motor performance factors. "The results indicate that the abilities contributing to performance on gross physical tasks are quite independent of those contributing to fine manipulative skill." (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

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19.
Airways epithelial cells may be involved in the pathogenesis of asthma, but their role remains to be determined. Epithelial cells can release large amounts of 15-hydroxy-eicosatetranoic acid (15-HETE) and smaller amounts of prostaglandin E2 (PGE2) as well as fibronectin, a mediator involved in epithelial repair after injury. Epithelial cells obtained after bronchial brushing of 16 asthmatic (age 38 +/- 5 yr) and 11 normal subjects (age 36 +/- 5 yr) were studied. The percentage of epithelial cells was assessed by immunocytochemistry using an anti-cytokeratin antibody. The viability of the cells was assessed by trypan blue exclusion. The release of 15-HETE PGE2 and fibronectin was studied in resting cells and after A23187 calcium ionophore stimulation. Epithelial cells always comprised more than 86% of cells recovered, and the viability of epithelial cells was significantly (p < 0.001, Mann-Whitney U test) greater in normal subjects (54 +/- 5%) compared with asthmatic subjects (13 +/- 1%). The release of 15-HETE and fibronectin by resting epithelial cells was significantly greater in asthmatics (p < 0.05, Mann-Whitney U test) than in normal subjects. A23187 significantly (p < 0.05, Wilcoxon W test) increased the release of 15-HETE and fibronectin. There was no significant difference in the release of PGE2 by resting cells from either asthmatics or normal subjects, but challenge with A23187 induced a significant (p < 0.03, Wilcoxon W test) increase in PGE2 from cells of asthmatics but not from cells of normal subjects. This study shows that epithelial cells are activated and less viable in asthma and suggests a role for these cells in asthma.  相似文献   

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