Differential Stimulation of Noradrenaline Release by Reversal of the Na+/Ca2+ Exchanger and Depolarization in Chromaffin Cells

We compared the effectiveness of Ca²⁺ entering by Na⁺/Ca²⁺ exchange with that of Ca²⁺ entering by channels produced by membrane depolarization with K⁺ in inducing catecholamine release from bovine adrenal chromaffin cells. The Ca²⁺ influx through the Na⁺/Ca²⁺ exchanger was promoted by reversing the normal inward gradient of Na⁺ by preincubating the cells with ouabain to increase the intracellular Na⁺ and then removing Na⁺ from the external medium. In this way we were able to increase the cytosolic free Ca²⁺ concentration ([Ca²⁺]_c) by Na⁺/Ca²⁺ exchange to 325 ± 14 nM, which was similar to the rise in [Ca²⁺]_c observed upon depolarization with 35 mM K⁺ of cells not treated with ouabain. After incubating the cells with ouabain, K⁺ depolarization raised the [Ca²⁺]_c to 398 ± 31 nM, and the recovery of [Ca²⁺]_c to resting levels was significantly slower. Reversal of the Na⁺ gradient caused an −6-fold increase in the release of noradrenaline or adrenaline, whereas K⁺ depolarization induced a 12-fold increase in noradrenaline release but only a 9-fold increase in adrenaline release. The ratio of noradrenaline to adrenaline release was 1.24 ± 0.23 upon reversal of the Na⁺/Ca²⁺ exchange, whereas it was 1.83 ± 0.19 for K⁺ depolarization. Reversal of the Na⁺/Ca²⁺ exchange appeared to be as efficient as membrane depolarization in inducing adrenaline release, in that the relation of [Ca²⁺]_c to adrenaline release was the same in both cases. In contrast, we found that for the same average [Ca²⁺]_c, the Ca²⁺ influx through voltage-gated channels was much more efficient than the Ca²⁺ entering through the Na⁺/Ca²⁺ exchanger in inducing noradrenaline release from chromaffin ceils. This greater effectiveness of membrane depolarization in stimulating noradrenaline release suggests that there is a pool of noradrenaline vesicles which is more accessible to Ca²⁺ entering through voltage-gated Ca²⁺ channels than to Ca²⁺ entering through the Na⁺/Ca²⁺ exchanger, whereas the adrenaline vesicles do not distinguish between the source of Ca²⁺.     

Chronic occupational exposure to organic solvents

Summary Twenty-two persons (20 men and 2 women) were examined for their external and internal exposure to the glycol ether 1-methoxypropan-2-ol (PGME) during the production, leak testing and mounting of brake-hoses. For the measurement of external exposure, personal air monitoring was the method of choice. Average concentrations of PGME of 82.2 mg/m³ (22.3 ppm), 68.6 mg/m³ (18.6 ppm) and 11.3 mg/m³ (3.1 ppm) were found in the air of the brakehose production, leak test and mounting areas, respectively. For the estimation of internal exposure to PGME, this glycol ether was measured in both urine and blood. The biological samples were taken post-shift. The highest internal exposure levels were found in the brakehose production section and in the leak test area. The average post-shift concentrations for PGME in workers in the brakehose production section were 4.6 mg/l in urine and 13.5 mg/l in blood; the corresponding figures for workers in the leak test area were 4.2 mg/l in urine and 11.0 mg/l in blood. In blood and urine samples of workers engaged in the mounting area, PGME levels were below the detection limits. The elimination kinetics of PGME were also studied in three highly exposed persons, and mean excretion half-lives of PGME of approximately 4.4 h were found. On the basis of our results we made a rough calculation of a future biological tolerance value: we would except that concentrations of 38-109 mg per litre of blood and 10–31 mg per litre of urine would correspond to the German MAK value for PGME (375 mg/m³).     

孕晚期妇女维生素B_1、B_2、C及能量需要量的研究

以武汉市纺织系统值车工孕晚期妇女43名为研究对象,采用饱和试验法对其维生素B_1,B_2和C需要量进行了初步研究,并对其能量消耗量和摄入量进行了调查。结果表明,维生素B_1最低需要量为1.65mg/d、适宜需要量为1.90mg/d,维生素B_2的最低需要量为1.45mg/d,适宜需要量为1.70mg/d;维生素C的最低需要量为46mg/d,适宜需要量为146mg/d。孕晚期值车工一日能量总消耗为9.5144MJ(2274kcal),一日能量摄入量为10.6566MJ(2547kcaI),能量摄入高于能量消耗1.1422MJ(273kcal)。再次表明,孕晚期妇女能量供给在未孕基础上增加0.8MJ(200kcal/d)是适宜的。     

血清可溶性白细胞介素2受体和T细胞亚群在单纯性肾病综合征患儿发病中作用的探讨

本文对26例儿童单纯性肾病综合征患者血清可溶性白细胞介素2受体（SIL-2R）及T细胞亚群进行研究。结果表明肾病活动期SIL-2R值升高（均值为895±245U／ml），CD_4~+／CD_8~+比值降低（P＜0.01），而肾病缓解期SIL-2R（均值为494±127U／ml）及CD_4~+／CD_8~+比值恢复正常，将SIL-2R值与CD_4~+／CD_8~+比值进行相关分析，发现两者呈负相关（r=-0.61，P＜0.05）。提示SIL-2R水平的升高及T细胞亚群的紊乱在儿童单纯性肾病发病机制中起到重要的作用。     

Modulation of human T cell functions by surface sulphydryl groups: differential effects on IL-2 production and responsiveness.

An impermeable thiol blocker has been used to investigate the role of sulphydryl (SH) groups in the production of and responsiveness to IL-2 by normal human T lymphocytes. Surface SH blockade of mononuclear cells prior to incubation with mitogen (phytohaemagglutinin, concanavalin A, CD3 MoAb) had no effect on production of IL-2 but markedly impaired cellular responsiveness to exogenous IL-2. Studies using MoAbs indicated that this effect was accompanied by decreased expression of both the CD25 and p75 subunits of the IL-2 receptor. Blocking surface SH groups did not affect binding of IL-2 to p75 on unstimulated mononuclear cells, but inhibited binding to high-affinity receptors on a T lymphoma cell line. The data are consistent with the hypothesis that sulphydryl groups on the IL-2 receptor are required for its function and may be involved in the interaction of the CD25 and p75 subunits leading to generation of the high-affinity binding site. The surface thiol identified on the IL-2 receptor may be a candidate for oxidation on cells from patients with chronic inflammatory diseases such as rheumatoid arthritis and thus contribute to the aberrant function of T cells in these patients.     

NMDA Receptor Activation Triggers Voltage Oscillations, Plateau Potentials and Burstinq in Neonatal Rat Lumbar Motoneurons ln Vitro

Whole-cell recordings of lumbar motoneurons in the intact neonatal rat spinal cord in vitro were undertaken to examine the effects of Kmethyl-D-aspartate (NMDA) receptor activation on membrane behaviour. Bath application of NMDA induced rhythmic voltage oscillations of 5.9 ± 2.1 mV (SD) at a frequency of 4.4 ± 1.5 Hz. Amplitude, but not frequency, of the voltage oscillations was membrane potential-dependent. Voltage oscillations could recruit action potentials and/or plateau potentials with or without superimposed bursting. Blockade of synaptic transmission with tetrodotoxin (TTX) sometimes resulted in a loss of oscillatory activity which could then be restored by increasing the NMDA concentration. After application of TTX, the trajectory of NMDA-induced oscillations was similar to the trajectory induced in the presence of intact synaptic networks, although the mean oscillation duration was longer and the oscillation frequency was slower (1.8 ± 1.1 Hz). Current ramps delivered after bath application of NMDA demonstrated bistable membrane properties which may underlie the plateau potentials. Injection of intracellular current pulses could initiate, entrain and terminate individual plateau potentials. The results suggest that membrane depolarization produced by oscillations may activate other intrinsic conductances which generate plateau potentials, thereby providing the neuron with enhanced voltage sensitivity, compared to that produced by NMDA receptor activation alone. These oscillatory events may have a role in the regulation of motor output in a variety of rhythmic behaviours including locomotion.     

Soluble CD14 but not interleukin-6 is a new marker for clinical activity in atopic dermatitis

Summary Levels of soluble IL-2 receptors, IL-6, soluble CD23, soluble CD14 and ECP (eosinophilic cationic protein) were measured as markers of T-cell, B-cell, monocyte and eosinophilic leucocyte activation in 26 patients with atopic dermatitis (AD) on admission to (A) and at discharge from (D) the Department of Dermatology in Zurich. The serum levels of sIL-2R, IL-6, sCD23, sCD14 and ECP were significantly elevated in AD patients in comparison with the normal values of healthy donors. A significant decrease in sIL-2R (p=0.0093) and in sCD14 (p=0.0134) levels was demonstrated between A and D, correlating with the improvement in the skin intensity score (SIS). In addition, a significant correlation of the sCD14 levels and the SIS at A was demonstrated (p=0.0415). These results also incriminate monocytes in the pathogenesis of AD, indicating that, besides sIL-2R and ECP, SCD14 could also be a possible marker for the disease activity.     

糖尿病肾脏胶原非酶糖化与氨基胍阿斯匹林的治疗作用

本实验系统观察了ＳＴＺ所致糖尿病鼠在１、３、６个月后肾脏组织胶原发生非酶糖化的情况，及氨基胍、阿斯匹林对肾脏胶原非酶糖化的阻断作用。结果表明：各病程糖尿病动物肾组织的胶原含量和非酶糖化早期产物（５－ＨＭＦ）及胶原相联荧光值均明显高于正常对照。氨基胍能够减弱糖尿病动物肾组织胶原含量的增加和荧光产物的生成，但对５－ＨＭＦ含量无影响。阿斯匹林未显示出对胶原非酶糖化的影响。     

Elevated serum levels of the apoptosis related molecules TNF-α, Fas/Apo-1 and Bcl-2 in oral lichen planus

BACKGROUND: The serum circulatory levels of apoptosis related molecules measured in patients with oral lichen planus (OLP) and healthy individuals in order to investigate possible alterations associated with the clinical forms of OLP. METHODS: Serum levels of tumor necrosis factor (TNF)-alpha, soluble Fas (sFas) and Bcl-2 studied by enzyme-linked immunosorbent assay in whole blood samples in 13 OLP reticular, 13 OLP atrophic-erosive form patients and 26 healthy subjects. RESULTS: Significantly elevated levels of TNF-alpha and sFas detected in OLP patients as compared with controls. Serum concentrations of Bcl-2 although increased in 17/26 patients, they were not statistically significant. Reticular OLP exhibited slightly elevated TNF-alpha and significantly elevated Bcl-2 serum levels, compared with erosive OLP. CONCLUSIONS: These data suggest that a putative dysfunction in the Fas/FasL mediated apoptosis might be involved in the OLP pathogenesis. A downregulation of Bcl-2 serum levels in the atrophic-erosive OLP may be associated with promotion of the disease activity.     

运用组织芯片技术检测COX-2在结直肠癌中的表达及其临床意义

目的 探讨结直肠癌组织中COX-2的表达及其与各临床病理因素的关系，评价COX-2在结直肠癌预后判断中的价值。方法 应用组织芯片技术结合免疫组织化学SABC法，检测126例早中期结直肠癌组织中COX-2的表达情况，回顾性分析COX-2与各临床病理因素及预后之间的关系。结果 根据免疫组化染色强度，所有病例被分为COX-2高表达组和低表达组，其中高表达组有32例（25．4％），低表达组有94例（74．6％）。COX-2在结直肠癌中表达情况与年龄、性别、肿瘤大小、肿瘤部位、组织学类型、浸润深度、淋巴是否转移、Dukes分期均无相关。然而，高表达的COX-2与肿瘤复发、特别是血行转移显著相关（P〈0．05）。两组之间生存率具有显著差异（P=0．0067），COX-2高表达组术后五年生存率显著低于低表达组。多因素回归模型分析结果显示．在潜在的预后因素中（年龄、性别、肿瘤大小、肿瘤部位、组织学类型、淋巴是否转移、Dukes分期、COX-2表达），COX-2表达和Dukes分期可作为是结直肠癌根治术后独立预后因素，COX-2的检测可作为结直肠癌患者预后判断的一个有价值的指标。结论 高表达的COX-2与肿瘤复发、特别是血行转移显著相关，COX-2的检测町作为结直肠癌患者琐后判断的一个有价值的指标：应用组织芯片高效检测临床组织样本具有快速、方便、经济、准确的优点。