Cytotoxicity of human pI 7 interleukin-1 for pancreatic islets of Langerhans

Activated mononuclear cells appear to be important effector cells in autoimmune beta cell destruction leading to insulin-dependent (type 1) diabetes mellitus. Conditioned medium from activated mononuclear cells (from human blood) is cytotoxic to isolated rat and human islets of Langerhans. This cytotoxic activity was eliminated from crude cytokine preparations by adsorption with immobilized, purified antibody to interleukin-1 (IL-1). The islet-inhibitory activity and the IL-1 activity (determined by its comitogenic effect on thymocytes) were recovered by acid wash. Purified natural IL-1 and recombinant IL-1 derived from the predominant pI 7 form of human IL-1, consistently inhibited the insulin response. The pI 6 and pI 5 forms of natural IL-1 were ineffective. Natural and recombinant IL-1 exhibited similar dose responses in their islet-inhibitory effect and their thymocyte-stimulatory activity. Concentrations of IL-1 that inhibited islet activity were in the picomolar range. Hence, monocyte-derived pI 7 IL-1 may contribute to islet cell damage and therefore to the development of insulin-dependent diabetes mellitus.     

Virus persists in beta cells of islets of Langerhans and is associated with chemical manifestations of diabetes

Molecular hybridization, monoclonal antibody, and electron microscopic analyses showed lymphocytic choriomeningitis virus (strains Armstrong and WE) persistently infecting cells of the islets of Langerhans in BALB/WEHI mice. When monoclonal or monospecific antibody conjugated with two different fluorochrome dyes was used to mark insulin-containing beta cells or viral antigens, viral nucleoprotein was identified predominantly in beta cells. Electron microscopy confirmed these findings by showing virions budding from the beta cells. Persistent infection was associated with chemical evidence of diabetes (hyperglycemia, abnormal glucose tolerance, and normal or low-normal concentrations of insulin). Concentrations of cortisol and insulin-like growth factor in blood were normal, as was the level of growth hormone in the pituitary gland. The virus-infected islet cells showed normal anatomy and cytomorphology. Neither cell lysis nor inflammatory infiltrates were routinely seen. Thus a virus may persistently infect islet cells and provide a biochemical and morphological picture comparable to that of early adult-onset diabetes mellitus in humans.     

Two types of somatostatin receptors differentiated by cyclic somatostatin analogs

Somatostatin receptors in rat brain, pituitary, and pancreas were labeled with two radioiodinated analogs of somatostatins 14 and 28. Two cyclic analogs of somatostatin, SMS201-995 and cyclo(Ala-Cys-Phe-D-Trp-Lys-Thr-Cys), showed biphasic displacement of binding to somatostatin receptors by these radioligands. In contrast, all other somatostatin analogs, including somatostatin-14, competed for the receptor sites with monophasic displacement of radioligand receptor binding. Thus two types of somatostatin receptors were identified. It was found that the pituitary and pancreas have predominantly one type of somatostatin receptor whereas the brain has both, and that different regions of the brain have various proportions of the two types. These findings suggest methods to characterize other types of somatostatin receptors subserving somatostatin's diverse physiological functions, including a potential role in cognitive function and extrapyramidal motor system control.     

小型太阳能热风油菜籽循环干燥设备研究

为进一步满足油菜籽干燥过程中低能耗高效率的要求,设计研制了一种小型太阳能热风油菜籽循环干燥设备。设备依靠太阳能集热器提供热风,干燥室内设有一对转向相反的筛网叶轮,转动的叶片延长油菜籽滞空时间,斗式提升机实现物料循环干燥。以油菜籽为干燥对象进行试验,研究干燥室进口热风风速、筛网叶轮转速、物料循环速率对含水率变化的影响,结合试验结果获得设备最优运行工况。试验结果表明：当使用波纹型太阳能集热器,进口风速为5 m/s,物料循环速率为800 kg/h,筛网叶片转速50 r/min时,油菜籽干燥速率最高,可满足日干燥量250 kg的干燥需求。     

对职权不作为司法审查的完善

1　一起重大伤亡事故引发的反思据《法制日报》2 0 0 0年 12月 3日报道 :2 0 0 0年12月 1日广东东莞市厚街镇赤岭村发生了一起令人震惊的塌楼事故 ,造成 8入死亡 ,2 8人受伤的惨剧。据悉 ,这起塌楼事件是由于业主擅自在一栋存在了 7年之久的非法建筑上加盖两层而引起的。同时 ,     

普通高校独立学院办学模式的探索

本文对普通高等本科学校主办独立学院的历史背景、运行机制进行了分析,并就目前独立学院发展中必须面对的几个实际问题进行了的探讨。     

Bile Acid secreted by male sea lamprey that acts as a sex pheromone

We show that reproductively mature male sea lampreys release a bile acid that acts as a potent sex pheromone, inducing preference and searching behavior in ovulated female lampreys. The secreted bile acid 7alpha,12alpha,24-trihydroxy-5alpha-cholan-3-one 24-sulfate was released in much higher amounts relative to known vertebrate steroid pheromones and may be secreted through the gills. Hence, the male of this fish species signals both its reproductive status and location to females by secreting a pheromone that can act over long distances.     

污泥土地利用途径分析

污泥中含有丰富的氮、磷和有机质等肥力成分,土地利用是污泥处置的主要途径。污泥和污泥堆肥的土地施用可以促进植物的生长、提高作物的产量以及明显改善土壤的物理和生物学性质,然而污泥中的重金属元素是限制其大规模农田利用的重要因素。污泥和施污土壤中重金属形态的研究可以用来评价土壤中重金属的生物有效性以及它们在土壤中的移动性。文章概述了提取土壤中重金属元素的主要方法及污泥土地利用的方式。     

“样式雷”建筑文化传承的途径研究

在推动民族文化职业教育特色发展的背景下,就高职教育中的古建筑工程技术专业如 何融入“样式雷”建筑文化进行了的分析,并从人才培养目标的制定、课程体系的构建、校园文化 的建设和数字技术的结合几方面对传承的途径给予了阐述。     

青藏铁路当雄至羊八井段路基边坡植被护坡研究

为了恢复青藏铁路对当地生态环境造成的破坏,减少铁路与自然景观的反差,保护铁路路基的长期稳定,在羊八井模拟的铁路路基边坡进行了种植试验,通过对5种耐寒、耐旱的草本植物筛选,选出了适合在当地用作铁路护坡的垂穗披碱草和鲁梅克斯。为青藏铁路植被护坡提供了理论依据。     

Chemoattractant-regulated mobilization of a novel intracellular compartment in human neutrophils

A novel mobilizable intracellular compartment was identified in human neutrophils by latent alkaline phosphatase activity. This compartment is mobilized to the plasma membrane much more readily than any identified granule subset and has kinetics of up-regulation in the membrane similar to those reported for a variety of receptor proteins. Triton X-100 permeabilization of both intact human neutrophils and subcellular fractions obtained by density-gradient centrifugation revealed that 70 percent of the alkaline phosphatase is located in an intracellular compartment distinct from primary, secondary, and gelatinase granules and from the plasma membrane. This compartment fully translocates to the plasma membrane after stimulation with nanomolar concentrations of the chemotactic peptide N-formylmethionylleucylphenylalanine.     

Behavioral acts elicited by stimulation of single, identifiable brain cells

By stimulation of and recording from all of the nerve trunks and from over 50 of the large nerve cell bodies in the isolated brain of the nudibranch Tritonia gilberti a map of the axonal paths and synaptic connections has been constructed. The nervous correlates of sensory and motor activities can be monitored in single cells of the intact animal. Similarly, discrete responses in local muscles of the body wall and complex behavioral sequences such as turning and swimming are triggered by stimulation of single identifiable units.     

基于组件GIS的造林小班地形分析的研究--以造林小班坡向为例

该文针对造林规划设计过程中需要用到的地形因子,基于组件式GIS二次开发的原理,运用ESRI公司的嵌入式组件开发工具MapObjects,讨论了规则数字网格高程模型与规则数字网点高程模型的建立过程,在此基础上对造林决策支持系统中立地类型划分、林种规划等所依赖的地形信息进行自动提取,并以小班坡向为例进行分析,提出了造林小班地形特征信息提取的最佳方法——基于统计分布理论的最大特征值法,从而有效地实现了地形信息的自动提取,为造林规划设计服务.      

应用食物交换份法编制食谱

本文阐述了一种新的编制食谱方法。这种方法科学、简便、易学 ,稍有一点营养学知识的人就能掌握。     

Fluid transport: concentration of the intercellular compartment

Intercellular spaces of Periplaneta rectal pads are visible at a magnification of x 100 and distend during fluid uptake. Samples (0.025 to 0.1 nanoliter) obtained by micropuncture from the spaces were consistently more concentrated than the fluid in the rectal lumen. This observation supports the hypothesis of "local" osmosis in epithelial fluid transport.