A mathematical model of thrombin production in blood coagulation,Part I: The sparsely covered membrane case

This paper presents the first attempt to model the blood coagulation reactions in flowing blood. The model focuses on the common pathway and includes activation of factor X and prothrombin, including feedback activation of cofactors VIII and V by thrombin, and plasma inhibition of factor Xa and thrombin. In this paper, the first of two, the sparsely covered membrane (SCM) case is presented. This considers the limiting situation where platelet membrane binding sites are in excess, such that no membrane saturation or binding competition occurs. Under these conditions, the model predicts that the two positive feedback loops lead to multiple steady-state behavior in the range of intermediate mass transfer rates. It will be shown that this results in three parameter regions exhibiting very different thrombin production patterns. The model predicts the effect of flow on steady-state and dynamic thrombin production and attempts to explain the difference between venous and arterial thrombi. The reliance of thrombin production on precursor procoagulant protein concentrations is also assessed.     

The effect of flow and mass transport in thrombogenesis

The paper presents a mathematical analysis of the contributions of flow and mass transport to a single reactive event at a blood vessel wall. The intent is to prepare the ground for a comprehensive study of the intertwining of these contributions with the reaction network of the coagulation cascade. We show that in all vessels with local mural activity, or in “large” vessels (d>0.1 mm) with global reactivity, events at the tubular wall can be rigorously described by algebraic equations under steady conditions, or by ordinary differential forms (ODEs) during transient conditions. this opens up important ways for analyzing the combined roles of flow, transport, and coagulation reactions in thrombosis, a task hitherto considered to be completely intractable. We report extensively on the dependence of transport coefficient k_L and mural coagulant concentration C_w on flow, vessel geometry, and reaction kinetics. It is shown that for protein transport, k_L varies only weakly with shear rate in large vessels, and not at all in the smaller tubes (d<10⁻² mm). For a typical protein, k_L∼10⁻³ cm s⁻¹ within a factor of 3 in most geometries, irrespective of the mural reaction kinetics. Significant reductions in k_L (1/10–1/1,000) leading to high-coagulant accumulation are seen mainly in stagnant zones vicinal to abrupt expansions and in small elliptical tubules. This is in accord with known physical observations. More unexpected are the dramatic increases in accumulation which can come about through the intervention of an autocatalytic reaction step, with C_w rising sharply toward infinity as the ratio of reaction to transport coefficient approaches unity. Such self-catalyzed reactions have the ability to act as powerful amplifiers of an otherwise modest influence of flow and transport on coagulant concentration. The paper considers as well the effect on mass transport of transient conditions occasioned by coagulation initiation or pulsatile flow. During initiation, instantaneous flux varies with diffusivity and bulk concentration, favouring the early adsorption/consumption of proteins with the highest abundance and mobility. This is akin to the ‘Vroman effect’ seen in narrow, stagnant spaces. The effect of flow pulsatility on k_L has the potential, after prolonged cycling, of bringing about segregation or accumulation of proteins, with consequences for the coagulation process.     

Neurocognitive outcome in patients with hypertyrosinemia type I after long-term treatment with NTBC

Objective  

The implementation of NTBC into treatment of hypertyrosinemia type I (HT I) greatly improved survival by prevention of acute liver failure and hepatocellular carcinoma. However, there are first reports of cognitive impairment in patients with elevated plasma tyrosine concentrations.     

2364名高中学生焦虑抑郁情绪的调查

目的：了解高中学生抑郁、焦虑状态的发生率及相关因素。方法：对2 364名高中学生采用Zung焦虑状态自评量表（SAS）和抑郁状态自评量表（SDS）进行评定。结果：抑郁状态的发生率为14.29%,焦虑状态的发生率为5.10%。抑郁和焦虑状态的发生率与性别、年级及是否独生子女无关;父亲文化程度及母亲文化程度与SDS评分显著正相关。结论：高中学生的情绪问题不容忽视。     

Intrarenal pheochromocytoma and renal artery stenosis

A rare case of intrarenal pheochromocytoma associated with a renal artery stenosis is reported. The association between phenochromocytoma and renal artery stenosis is discussed.     

苗族,布依族和汉族躁狂症的跨文化研究

对符合ＣＣＭＤ－２－Ｒ躁狂发作诊断标准的苗族，布依族１１２例和汉族２２０例躁狂症患者的临床变量进行变化研究，两组患者在平均起病年龄，平均入院年龄，就诊早晚，求助巫医，妄想内容等方面存在显著性差异，提示与民族社会文化背景，宗教信仰和生活习俗等因素有关。     

Primary osteoma of the sphenoid sinus

Osteomas of the nose and paranasal sinuses are rather common benign tumors arising in the head and neck area. The sphenoid sinus is involved in various inflammatory and neoplastic conditions; however, an osteoma arising from the sphenoid sinus proper has not been reported in the available literature. This paper reviews, in detail, osteomas of the paranasal sinuses and their incidence, and a case of a sphenoid sinus osteoma is presented with radiological and pathological findings.     

贵州省部分地区酒依赖流行病学调查

目的：了解21世纪初贵州部分地区酒依赖患病率与1986年比较的变动情况。方法：按照《调查手册》的调查流程及各种筛选和诊查工具调查解贵州部分地区的9864人。结果：在所调查的≥15岁的7970人中，酒依赖（含酒精中毒性精神障碍）时点患病率、终生患病率均为3．89‰，与1986年比较，有明显上升。结论：酒依赖患病率明显上升，应列为物质滥用的防治和研究的重点之中。