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61.
Intermediate filaments derived from different cell types are antigenically distinct. Monoclonal antibodies to human intermediate filament proteins can, therefore, be used as tissue-specific reagents capable of distinguishing cell type in poorly differentiated neoplasms. We report a case demonstrating the specificity of antiintermediate filament protein antibodies in establishing a difficult orbital diagnosis of esthesioneuroblastoma.  相似文献   
62.
We evaluated the influence of individually estimated portion sizes on the estimate of nutrient related risk of colorectal cancer, using data from a Portuguese hospital based case-control study on diet and colorectal cancer. A total of 100 patients with colorectal adenocarcinoma (aged 15-92 years) and 211 controls (aged 36-89 years) were included. Two data sets were created for nutrient analysis, the first one allowed estimates of food intake using data on portion size as collected with visual aids during the interview. The second estimate substituted respondents' estimate with a standard portion size, as used in the semi-quantitative (SQ) food frequency approach. The two analytic approaches yielded similar energy and nutrient intakes in cases and controls. The percent range of concordance is acceptable, in the same quartile varying from 44 to 82% (mean: 56%) and very good in the same or adjacent (+/-1) quartile (mean: 91%, range: 85-97%). The two estimates lead to a similar pattern of multivariate odd's ratio, however the SQ estimates resulted in more significant findings. We conclude that little extra information is gained by including individual portion size information when assessing diet-related risk of colorectal cancer.  相似文献   
63.
Ultrastructural and immunohistochemical studies of clinically intact skin obtained from three severe neonatal cases of epidermolysis bullosa herpetiformis (Dowling-Meara type) demonstrated disorders in the assembly of keratin intermediate filaments and desmosomes of the keratinocytes. During mitosis, K5- and K14-positive and K1- and K10-negative tonofilaments were disrupted and formed spherical bodies associated with intracytoplasmic desmosomes by invagination of the desmosomes and the adjacent plasma membrane. During the invagination process, destructive changes in the internalized membrane were noted. These were accompanied by gradual loss of reactivity with a monoclonal antibody ZK31, which detected plasma membrane adjacent to the attachment plaques of desmosomes. However, the reactivity of the attachment plaques of the internalized desmosomes for desmoplakins and desmoglein did not decline during the process of internalization. In the suprabasal layers of the epidermis, filamentous substructures and K1 and K10 appeared at the periphery of the spherical bodies. Simultaneously, the desmosomes that were sparsely located in the lower epidermis, increased in number as cell differentiation progressed. Thus, the keratinocytes attained an almost normal appearance with respect to tonofilaments and desmosomes by the time they reached the upper layer of the epidermis. These findings may be relevant to the mechanism responsible for the clinical appearance of the herpetiform blisters in epidermolysis bullosa herpetiformis, which are also characterized by spontaneous involution during childhood or when exposed to high ambient temperatures.Part of this work was presented at the annual meeting of the Japanese Society for Ultrastructural Cutaneous Biology, 12 May 1990, Tokushima, Japan, at the joint meeting of the Society for Cutaneous Ultrastructure Research and the Japanese Society for Ultrastructural Cutaneous Biology, 23–25 May 1991, Vienna, Austria, and at the sixth Conference on Disorders of Keratinization, 6 July 1991, Tokyo, Japan  相似文献   
64.
The aim of the present study was to investigate whether ultrastructural features can be used as a guide to identify alpha- and gamma-motoneurons among the intermediate-size neurons of the peroneal motor nuclei. The peroneus brevis and peroneus tertius muscles of adult cats were injected with horseradish peroxidase, and motoneurons labeled by retrograde axonal transport were examined by electron microscopy. In both nuclei, the distributions of cell-body diameters, measured in the light microscope, were bimodal covering the range of 28-84 microns, with a trough around 50 microns. The sample of 25 motoneurons selected for the ultrastructural study included not only large (presumed alpha) and small (presumed gamma) neurons but also intermediate-size cell bodies with diameters in the 40-60 microns range. For each motoneuron, 2-5 profiles were reconstructed from ultrathin sections taken at 6-8 microns intervals. Synaptic boutons were counted and their lengths of apposition were measured. On the basis of three criteria, namely: (1) bouton types present on the membrane, (2) percentage of membrane length covered by synapses, and (3) the aspect of the nucleolus, all the examined motoneurons, including those with intermediate sizes, fell into one of two categories. Fourteen motoneurons, with cell-body diameters in a range of 55-84 microns, were contacted by all types of boutons (mainly S-type with spherical vesicles, F-type with flattened vesicles, and C-type with subsynaptic cistern); the synaptic covering of the somatic membrane was over 40% and the nucleus contained a vacuolated nucleolus. These were considered alpha-motoneurons. Eleven motoneurons, with only S and F boutons, a synaptic covering under 30%, a compact nucleolus and a cell-body diameter ranging between 28 and 50 microns, were considered gamma-motoneurons. No other combination of the three criteria was observed. These results show that unequivocal distinction of alpha- and gamma-motoneurons is possible in the peroneal nuclei, on the basis of morphological differences independent of cell-body size.  相似文献   
65.
目的:探讨乳腺导管声学造影对乳头溢液性病变的诊断价值。方法:34例乳头溢液患者术前均行高频超声及声学造影检查,所有检查结果均与手术病理结果比较。结果:乳头溢液疾病高频超声及声学造影检查结果与手术病理结果比较诊断符合率分别为61.7%及79.4%,二者比较差异无统计学意义(P>0.05)。导管内乳头状瘤高频超声与声学造影诊断符合率分别为40%及73.3%,二者比较差异有统计学意义(P<0.05)。结论:乳腺导管声学造影可提高导管内小病变的检出率,显示详细的病变部位及扩张的导管,为手术提供重要的参考依据。尤其是导管内乳头状瘤声学造影检查明显优于高频超声检查。此种检查简单、方便、准确性较高,可作为乳头溢液性疾病的首选检查方法。  相似文献   
66.
Referenceless, or self-reference, thermometry is a technique for mapping temperature differences in the region of interest (ROI) using the baseline phase estimated by extrapolating the field in the surrounding region for estimation (RFE) and subtracting the estimated baseline from the measured field. In the present work a self-reference technique based on complex field estimation using 2D polynomials comprising complex-valued coefficients was proposed and optimized. Numerical simulations with a Gaussian-profiled phase distribution demonstrated that the ROI radius had to be 2.3-2.5 times the standard deviation (SD) of the Gaussian function in order to keep the error below 8% of the peak phase change. The area ratio between the ROI and the RFE had to be larger than 2.0 to maintain the error level. Based on the simulations, and phantom and volunteer experiments, the complex-based method with independently optimized polynomial orders for the two spatial dimensions was compared with the phase-based method using the similar-order optimization strategy. The complex-based method appeared to be useful when phase unwrapping was not removed. Otherwise, the phase-based method yielded equivalent results with less polynomial orders.  相似文献   
67.
Previous research has shown that separation discrimination thresholds are independent of the internal spatial scale (local spatial frequency) of the targets whose separation is being judged. The experiments reported here tested the generality of this conclusion for separation discrimination of targets that were embedded in an array of identical objects, where crowding could enhance the importance of the scale at which the individual target locations are encoded. No effect of the local spatial scale of the targets was found under these conditions.  相似文献   
68.
以高频喷射通气结合胸壁挤压(HFJV+CWC)为通气模式,观察其对组胺致肺损伤犬呼吸循环功能的影响,并与单纯高频喷射通气(HFJV)进行比较。结果表明:与HFJV相比,HFJV+CWC时的功能残气量(FRC)、PaCO_2和PCO_2均显著降低(P<0.01),肺泡通气量(V_A)和二氧化碳排出量(CO_2)均显著增高(P<0.01),每分呼出气量(V_E)、PaO_2、PCO_2、吸气峰压(PIP)、平均气道压(Paw)、呼气末压(EEP)、HR、平均动脉压(MAP)、肺动脉压(PAP)和肺毛细血管楔压(PCWP)均无显著变化(P>0.05)。提示:HFJV+CWC除保留单纯HFJV时气道开放、气道低压、良好的血液氧合、不影响循环功能等特点外,还具有增加呼气动力,改善肺泡通气,显著促进CO_2排除等优点。  相似文献   
69.
Large dendritic cells were cultured from facial angiofibromas of six patients with tuberous sclerosis. The cells were examined immunocytochemically for expression of selected cytoskeletal and non-structural proteins and the results compared with the staining profiles obtained with normal skin fibroblasts and normal glial cells. In similarity to normal glia, the angiofibroma stroma cells expressed glial fibrillary acidic protein (GFAP). Conversely, by analogy to fibroblasts, the abnormal stroma cells produced fibronectin and did not react with the antibody to S-100 protein. By immunogold labelling it was established that GFAP and vimentin were co-localized in intermediate filaments of the angiofibroma cells.  相似文献   
70.
高频喷射通气时麻醉犬动脉血二氧化碳分压的估计   总被引:2,自引:0,他引:2  
孙喜庆  吴兴裕 《医学争鸣》1994,15(3):211-213
作用测定5-8次常频呼吸后呼气末二氧化碳分压的方法,探讨了高频喷射通气时麻醉犬动脉脉血二氧化碳分压与Petco2的关系,结果表明,在通气频率分别为60,100及200次/min时,Petco2和Paco2均无显性差异,Petco2呈显相关(r=0.83,P<0.01)。结果提示,测定5-8次常频呼吸后的Petco2可较准确地评估HFJV时麻醉犬的Paco2。  相似文献   
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