Evaluation of computerized analysis of the propagation of human duodenojejunal contractions

Abstract Detection of peristalsis in the human small intestine has been limited in the past by both the available measurement techniques and the complexity of this activity. Recent developments in ambulant recording have provided a means of monitoring the occurrence of intestinal contractions at multiple sites in the small bowel, but the problem of complexity remains. Using digital data recorded from an intra-luminal strain-gauge transducer in the proximal gut, an algorithm was implemented to identify and classify contractile events within the small bowel. By modelling propagated activity the effect of varying transducer spacing and the number of transducers used was assessed. The question of variability of apparent velocity of peristaltic contractions was examined using successive cross-correlation calculations to extract underlying phase differences between samples of 512 minutes of manometric recording over 150 mm of human small bowel. The effective velocity was found to have a median value of 14 mm sec^-1 and an inter quartile range of 12–18 mm see^-1). It is proposed that, in dynamically tracking variations in phase difference between adjacent recording sites, cross-correlation techniques should be used to control the parameters used for the recognition of propagated contractile events and thereby improve the specificity of this process.     

Numerical comparisons of two formulations of the logistic regressive models with the mixed model in segregation analysis of discrete traits.

Segregation analysis of discrete traits can be conducted by the classical mixed model and the recently introduced regressive models. The mixed model assumes an underlying liability to the disease, to which a major gene, a multifactorial component, and random environment contribute independently. Affected persons have a liability exceeding a threshold. The regressive logistic models assume that the logarithm of the odds of being affected is a linear function of major genotype effects, the phenotypes of older relatives, and other covariates. A formulation of the regressive models, based on an underlying liability model, has been recently proposed. The regression coefficients on antecedents are expressed in terms of the relevant familial correlations and a one-to-one correspondence with the parameters of the mixed model can thus be established. Computer simulations are conducted to evaluate the fit of the two formulations of the regressive models to the mixed model on nuclear families. The two forms of the class D regressive model provide a good fit to a generated mixed model, in terms of both hypothesis testing and parameter estimation. The simpler class A regressive model, which assumes that the outcomes of children depend solely on the outcomes of parents, is not robust against a sib-sib correlation exceeding that specified by the model, emphasizing testing class A against class D. The studies reported here show that if the true state of nature is that described by the mixed model, then a regressive model will do just as well. Moreover, the regressive models, allowing for more patterns of family dependence, provide a flexible framework to understand gene-environment interactions in complex diseases.     

乙肝病毒X基因对肝癌细胞表达RhoC的影响

目的：探讨X基因对肝癌细胞表达RhoC基因的影响。方法：用定向克隆的方法构建X基因的真核表达载体pcDNA3.1-X，脂质体转染HEPG2细胞;潮霉素选择培养稳定表达X基因的HEPG2-X细胞;免疫组化鉴定HEPG2-X细胞RhoC蛋白表达。结果：构建的真核表达载体pcDNA3.1-X在HEPG2细胞中有稳定表达，HEPG2-X细胞表达RhoC蛋白增强。结论：体外条件下，X基因可促进肝癌HEPG2细胞RhoC表达增强。这可能与肝癌的侵袭、转移有关。     

颅底胆脂瘤的MRI特征

目的探讨颅底胆脂瘤MRI分型的意义及其MRI诊断特征。方法观察15例颅底胆脂瘤的CT、MRI与病理学资料，根据肿瘤T1WI信号的不同，将颅底胆脂瘤分为Ⅰ型和Ⅱ型，分析两型胆脂瘤在CT、MRI征象和颅底骨质侵犯等方面的差异。结果15例颅底胆脂瘤T2WI显著高信号，肿瘤实质无强化。15例中，Ⅰ型，6例，肿瘤位于桥前池和桥小脑角区，CT均匀低密度，T1WI均匀低信号，包膜不强化，颅底骨质改变轻微，肿瘤实质为胆固醇结晶；Ⅱ型，9例，肿瘤位于一侧中、后颅窝底，CT呈混杂密度，T1WI呈混杂信号，其中4例为低信号中夹杂少量高信号，另5例以高信号为主，包膜强化，颅底骨质呈显著外压性改变，肿瘤实质为角化上皮和蛋白。结论颅底胆脂瘤分为Ⅰ型和Ⅱ型是合理的，体现了两型颅底胆脂瘤组织病理和生物学行为的差异，对指导MRI诊断有积极意义。T1WI信号多样性、T1WI显著高信号、肿瘤实质不强化以及与MRI分型相关的颅底骨质侵犯是颅底胆脂瘤的MRI诊断特征。     

试尖对根管充填质量影响的研究

目的：了解试尖对侧向加压法根管充填质量的影响因素。方法：随机提取我院1998年10月至2004年12月所完成的根管充填病例的X线片1000例，按试尖与未试尖，分别对前牙、前磨牙和磨牙根管充填质量进行分析。结果：在482例未试尖根管充填病例中，前牙、前磨牙和磨牙的适充比例分别为46％、37％和23％，欠充为20％、29％和47％。超充为34％、33％和29％：在518例试尖病例中，前牙、前磨牙和磨牙的适充比例分别为68％、62％和51％，欠充为6％、12％和13％，超充为25％、24％和36％。结论：在侧向加压法根管充填中，试尖可明显改善充填质量。     

Virtual real-time digital processing of hemodynamic data

At present, the majority of cardiac catheterization laboratories acquire and store hemo-dynamic data in analog form. To examine the possibility of performing complex analysis of digital data during the catheterization procedure, we examined whether virtual realtime digital (fast Fourier) analysis improves the accuracy of clinical data. We compared digital filtering of fluid manometry during right heart catheterization with 10-Hz and 250-Hz analog filters. Using the simultaneously acquired micromanometry as the “gold standard,” we found that analog filtering is associated with a greater error and time delay than digital filtering. This study demonstrates that digital hemodynamic data analysis performed during cardiac catheterization can improve the quality of data obtained during right heart catheterization, with the results available within seconds. More extensive use of computers in the cardiac catheterization laboratory may be useful for both clinical and research purposes. © 1992 Wiley-Liss, Inc.     

The usefulness of detailed information to patients with contact allergy

To find out if patients with contact allergy are helped by computerized information lists, a retrospective study was carried out on 58 patients with contact allergy to lanolin, traced through our local database DALUK. All were sent a questionnaire about their usage of the information list, clearance of their eczema, their education and other details. Clearance of the patient's eczema was found to correlate with use of the information list. It was also found that the effectiveness of the information depended on factors such as education, family circumstances, ethnic background and, most of all, how and where the information list was used.     

人眼调制传递函数自动测试装置

本文介绍一个用单片机控制的人眼视网膜－大脑系统调制传递函数测量装置，与传统方法不同，该装置调制对比度是利用电光晶体控制激光束强度的来达到的。该装置不但可以测量空间调制传递的函数，还可测量时－空调制传递函数，并以数据和曲线的形式打印输出。