The acetylcholinesterase defect in paroxysmal nocturnal hemoglobinuria: evidence that the enzyme is absent from the cell membrane

Paroxysmal nocturnal hemoglobinuria (PNH) is a myelodysplastic disease characterized by erythrocytes that show abnormally increased sensitivity to complement-mediated lysis. Complement-sensitive PNH erythrocyte membranes have previously been shown to lack acetylcholinesterase (AchE) activity, but the molecular basis of this deficiency has been unclear. We have used monoclonal antibodies to four different epitopes on the AchE molecule to show that abnormal PNH erythrocytes failed to bind these antibodies. Moreover, abnormal PNH erythrocytes contained no protein immunoprecipitable by these antibodies, while normal complement-insensitive erythrocytes from PNH patients showed normal amounts of immunoprecipitable AchE which had normal electrophoretic mobility. These data suggest that abnormal PNH erythrocytes lack AchE enzyme activity due to the absence of the AchE molecule from the cell membrane.     

美式脊椎矫正学为脊椎疾病康复干预注入新的内容与活力

目的:阐述美式脊椎矫正学(Chiropractic)的发展史与现状,从人体健康的平衡观、整体观及脊椎、脊柱的力学结构方面介绍脊椎矫正学的理论体系。方法:查阅关于美式脊椎矫正学的国外3部著作,同时检索2002-10/2006-01中国期刊全文网关于美式脊椎矫正学的相关文献,检索词为“美式脊椎矫正”。结果:脊椎矫正学的主要目标是针对人体脊椎功能异常和/或与神经系统的关系,找出并恢复位移异常的脊椎,去除对神经系统的影响,使身体回到健康自然的状态。其主要治疗特点是针对性强,无创伤,无痛苦,疗效显著,安全系数高,是绿色疗法、纯自然疗法。结论:脊椎矫正学从人体健康的平衡观、整体观出发,对脊椎、脊柱的力学结构进一步重新认识,从而对脊椎、脊柱常见病、多发病已经形成了自己独到的理论体系,以及相应的诊疗方法,这些理论和方法过去和现在已经被越来越多的临床实践所证实。     

Distinction of hepatic cavernous hemangioma from hepatic metastases with MR imaging

Twenty-four hepatic cavernous hemangiomas and 91 metastases from a variety of hypovascular and hypervascular primary neoplasms were prospectively studied with magnetic resonance (MR) imaging. In addition to qualitative analysis, quantitative analysis of signal intensity ratios of lesion to normal liver was performed with images obtained with 500/28-30 (repetition time msec/echo time msec) and 2,000/28-150 sequences. Quantitative data did not improve the ability to distinguish hemangiomas from metastases in our series compared with qualitative analysis. Hypovascular metastases, such as colon carcinoma, could be differentiated from hemangioma more frequently (97.5%) than hypervascular endocrine metastases, such as islet cell tumor, carcinoid, and pheochromocytoma (61%). These findings indicate that the utility of MR imaging in differentiating hemangiomas from metastases is dependent on the histologic type of the primary neoplasm.     

Mach bands in mammography

The radiologic appearance of tissue surrounding a tumor often influences the characterization of a cancerous lesion. An example is the radiolucent halo that is sometimes seen around breast cancers. Mammograms of 108 malignant tumors (74 scirrhous tumors, 17 partially scirrhous nodular tumors, and 17 nodular tumors) and eight benign tumors that showed peritumoral fat were retrospectively evaluated. All the scirrhous and partially scirrhous nodular cancers were more or less surrounded by a 5-10-mm-wide hyperlucent halo; this corona sign was also found in 14 nodular cancers. The halo sign, a hyperleucent 1-mm band, was observed around all benign lesions and immediately adjacent to sharply delineated cancers. These radiologic findings are an optical illusion (Mach band, background contrast effect). Densitometric measures and isoluminous analysis did not demonstrate the presence of a true hyperlucent zone.     

US of the upper abdomen: factors influencing image quality

A controlled blind study of 226 patients was performed to determine the advantages of fasting prior to upper abdominal ultrasonography (US) as well as the influence of other factors on image quality. The ratio of weight to height (a reflection of body build) was found to most often correlate negatively with image quality for all organs, followed by age for the biliary tract, pancreas, and kidneys and sex (in males) for the pancreas. Only the biliary tract was shown slightly better as the result of fasting. Images obtained during the afternoon tended to be somewhat better. The authors conclude that upper abdominal US can be performed at any time in patients who have not fasted, as it is primarily other factors that determine image quality. Only if evaluation of the biliary tract is inconclusive need the patient be reexamined after fasting.     

激光在前列腺外科的应用

0引言 前列腺增生症（benign prostatic hyperplasia,BPH）是50岁以上男性最普遍的疾病．随着社会人口老龄化趋势的加快,男性人群遭受BPH痛苦的人数迅速上升．经尿道前列腺电切术（transurethral resectionof the prostate,TURP）是公认的治疗BPH的“金标准”．但是,目前激光技术凭借其微创、并发症少等优点对BPH治疗的“金标准”产生挑战．在此我们综述了近年激光在前列腺外科的应用现状．     

Focal and diffuse liver disease studied by quantitative microstructural sonography

Quantitative microstructural sonography differs from conventional sonography in several ways. The frequency as well as the amplitude of echoes is recorded and assessed using spectral analysis techniques. The effects of diffraction of the ultrasound beam are calibrated, as are the transfer characteristics of the system. Studies of patients with alcoholic liver disease revealed significantly increased attenuation, heterogeneity of scatterers, and local scattering strength in those with severe disease; in contrast, patients with mild cirrhosis exhibited decreased local scattering strength compared to normal individuals. Using retrospective three-parameter discriminant analysis, 23 out of 24 patients were successfully categorized, suggesting that the parameters used were capable of measuring microstructural changes associated with these disease states. Parameters varied widely among 6 types of hepatic tumors, suggesting that this method may offer promise in distinguishing tumors from normal cases and alcoholic liver disease as well as from each other. Further applications and evaluation of this method appear justified.