Differential binding kinetics of cholera toxin to intestinal microvillus membrane during development

A complete randomized block design was used to compare the binding kinetics of cholera toxin to developing rat enterocyte microvillus membranes prepared from newborn, 2-week-old, 4-week-old, and adult animals. Saturation-binding isotherms were generated on 16 independent samples (four blocks) under steady-state and reversible conditions. Scatchard analyses suggested positive cooperative binding to a single class of receptors, and the isotherms were analyzed by both the Hill-Waud and Michaelis-Menten functions. Receptor density varied significantly with age (P = 0.013). An abrupt rise in receptor density occurred after the neonatal period and normalized in the adult animal. The half-dissociation constant also varied significantly with age (P = 0.019). Microvillus membranes from suckling animals had a slightly higher apparent affinity than those from weaned animals. Neither receptor concentration nor membrane purity confounded these observations. Whereas age-related changes in apparent affinity correlated with cellular responses, changes in receptor density did not. This study suggests that developmental changes in membrane structure which influence binding affinity but not receptor density may, in part, contribute to the increased sensitivity of suckling rats to cholera toxin exposure.     

Post-synthetic modification in vivo of the major hemoglobin beta chain in the rat

Rat hemoglobins are unusually heterogeneous among mammals. This heterogeneity provides multiple opportunities for asynchronies in synthesis and degradation. We have examined rat hemoglobin turnover after an intravenous injection of 2-14C-glycine. After analyzing incorporation into the seven nonallelic globin chains of adult rats, we found the percentage of the major beta chain decreases over the red cell lifespan while the percentage of one of the minor beta chains increases. This suggests that a post-synthetic modification event converts a portion of the latter into the former.     

Single photon emission computed tomography using 99mTc-HM-PAO in the routine evaluation of Alzheimer's disease

Regional cerebral blood flow was studied in 7 patients with clinically suspected Alzheimer's disease and 10 normal controls by single photon computed emission tomography (SPECT) using HM-PAO. All patients with Alzheimer's disease and no controls had parietal lobe hypoperfusion which was usually bilateral. In patients with more severe dementia hypoperfusion extended into the frontal lobes. Parietal lobe hypoperfusion corresponds to parietal lobe degeneration which is the one of the first neocortical regions to show the typical degenerative changes of Alzheimer's disease. SPECT with HM-PAO is a non-invasive investigation available in most nuclear medicine departments and complements existing tests in the routine evaluation of patients presenting with dementia.     

Limb-length discrepancy measured with computerized axial tomographic equipment

A simple, rapid, and accurate method for measuring limb-length discrepancies with computerized axial tomographic equipment is described. With this method less irradiation is delivered and some of the errors of computation are eliminated, compared with conventional methods. The costs of the technique are comparable with those of scanograms. The method is particularly applicable in the patient who has contracture of a joint.     

Comparison of hand-sewn and stapled esophagogastric anastomosis after esophageal resection for cancer: a prospective randomized controlled trial.

OBJECTIVE: The objective of this study was to compare the hand-sewn and stapled methods in esophagogastric anastomosis. SUMMARY BACKGROUND DATA: After esophageal resection for cancer, the relative merits of the hand-sewn and the stapled methods of esophagogastric anastomosis, especially regarding leakage and stricture rates, have not adequately been studied. METHODS: A prospective randomized controlled trial was undertaken in 122 patients with squamous cell cancer of the thoracic esophagus who underwent a Lewis-Tanner esophagectomy. Patients were stratified according to esophageal size, based on the diameter of the divided esophagus (< or > or = 30 mm) and then were randomized to have either a hand-sewn or a stapled anastomosis. RESULTS: The mean total operating times (standard error of the mean) when the hand-sewn and the stapled methods were used were 214 (4) minutes and 217 (3.4) minutes, respectively (p = not significant [NS]). The respective in vivo proximal resection margins (standard error of the mean) were 8 (0.4) cm and 7.6 (0.4) cm (p = NS). Leakage rates were 1.6% and 4.9% (p = NS). Excluding hospital deaths, patients with leakage or anastomotic recurrence, and those who received radiation therapy to histologically infiltrated resection margin, anastomotic stricture was found in 5 (9.1%) of 55 patients in the hand-sewn group and 20 (40%) of 50 in the stapler group (p = 0.0003). The difference in stricture rates was significant in small as well as large esophagi. Anastomotic recurrence developed in only one patient in each group. CONCLUSIONS: The authors conclude that both methods were safe, but the stapled technique resulted in more stricture formation.     

显微外科治疗颅内肿瘤65例临床分析

目的：介绍65例颅内肿瘤显微外科手术治疗经验；方法：本组患者65例，根据肿瘤部位、大小、性质，选择合适的手术入路，采用显微手术切除肿瘤；结果：全切53例，部分切除12例，无手术死亡；术后并发视神经麻痹1例，面神经并动眼神经麻痹1例，三叉神经麻痹1例，舌咽神经麻痹1例，偏瘫5例，无其他手术并发症；结论：正确的手术思路、合适的手术入路是手术成功的基础；采用显微外科手术技术是提高全切率、减少并发症的关键。     

动态血压监测的临床评定

无创性动态血压（ＡＢＰＭ）能较客观地反映血压水平及其昼夜变化规律，对高血压病的诊断、指导用药、药物疗效的评定以及预后评估等均有较大价值。本文对ＡＢＰＭ的发展及临床应用等问题进行综述。     

MRI在膝关节损伤诊断中的应用价值

目的:通过膝关节损伤MRI影像的分析,确定其诊断价值及意义。材料和方法:本文收集了自1992年以来我院所检查的42例膝关节损伤患者,52个膝关节成像。其中男性34人;女性8人,各年龄组以30～40岁组最多。损伤以前交叉韧带和外侧半月板损伤者多见,分别占总损伤数的20％及30％。损伤又以左膝多见,占总数的61％。结果:MRI能较明确地显示膝关节的半月板、关节软骨、韧带、滑膜及骨质的改变,明显地比CT所能看到的层次多,对软组织的损伤显示清晰。结论:只要正确地应用不同序列及切层方向、厚度等技术,可清晰地显示其信号特征,从而能确定其损伤部位、程度。