Acidic ATP activates lymphocyte outwardly rectifying chloride channels via a novel pathway

Using whole-cell patch-clamp techniques we found that ATP activated an outwardly rectifying current in Daudi human B lymphoma cells under acidic conditions. The substitution of Cl^– for gluconate^– shifted the reversal potential, while Cl^– channel blockers, 4,4-diisothiocyanostibene-2,2-disulfonic acid (DIDS) and 9-anthracene carboxylic acid (9-AC), blocked the current, indicating that ATP induces this current by activating the outwardly rectifying chloride channel (ORCC). The effect of ATP on ORCC was mimicked by ADP, but not by other P2 receptor agonists such as ATPS (a poorly hydrolyzable analog of ATP), 2,3-O-benzoyl-4-benzoyl-ATP (BzATP), and UTP. The ATP-induced ORCC current was completely blocked by 100 M suramin (a P2 receptor antagonist), and was partially blocked by 100 M pyridoxal-phosphate-6-azophenyl-2,4-disulfonic acid tetrasodium (PPADS), which is another P2 receptor antagonist. Neither inactivation of G proteins nor elimination of extracellular Ca²⁺ affected the ATP-induced current, indicating that G protein-coupled P2Y receptors and Ca²⁺-permeable P2X receptors are not involved. Based on the pharmacological profile and the fact that acidic conditions are required for ATP to activate the ORCC, we suggest that acidic ATP activates the lymphocyte ORCC via a novel pathway, which is not associated with any previously described purinergic receptors.     

Identification and characterization of neurons with tremor-frequency activity in human globus pallidus

 Many previous studies have demonstrated the existence of neurons with tremor-frequency activity (”tremor cells”) in the thalamus of Parkinson’s disease (PD) patients and these neurons are presumed to play a role in the pathogenesis of tremor. Since a major input to motor thalamus (Voa and Vop) is from the internal segment of the globus pallidus (GPi), neurons with tremor-frequency activity in motor thalamus may receive input from neurons in GPi. The aim of this study was to quantify the characteristics of tremor cells in human globus pallidus. In three PD patients with tremor undergoing microelectrode exploration of the globus pallidus prior to pallidotomy, 228 neurons were sampled, and 28 (12.3%) were identified to fire at the same frequency as the tremor. These ”tremor cells” were located in the ventral portion of GPi. Autocorrelogram analysis of the sampled spike trains of these 28 tremor cells was carried out over sequential 10-s time segments, and autocorrelograms showing maximal oscillatory activity were graded from 0 to 10. Average tremor cell oscillation grades ranged from 6.8 to 7.8, similar to those reported in the MPTP-induced primate model of parkinsonism. The average tremor cell oscillation grade varied between patients, as did the clinical measures of tremor severity. Tremor cells had oscillations in spike discharges at the same average frequency (4.2–5.2 Hz) as the patient’s tremor determined from the electromyogram and accelerometry records of one or more limbs (4.0–5.4 Hz), and the individual values were correlated (r ²=0.73) over the total range (3.7–5.6 Hz). The results of this study demonstrate the presence of neurons with 4–6 Hz tremor-frequency activity in GPi, supporting a role of the globus pallidus in the production of rest tremor in PD patients. Received: 27 February 1996 / Accepted: 18 October 1996     

Elevation of CD8+ CD11b+ Leu-8− T cells is associated with the humoral immunodeficiency in myeloma patients

Recurrent bacterial infections due to humoral immunodeficiency are an important cause of death in myeloma patients. Recent data indicate that CD8⁺ T lymphocytes and a reduction of T helper type 1 cells with disease progression may be involved in the regulation of polyclonal immunoglobulin secretion. In mixed lymphocyte cultures derived from peripheral blood mononuclear cells (PBMC) of 24 myeloma patients with reduced immunoglobulin serum levels we investigated the association of CD4⁺ and CD8⁺ T cell subsets and immunoglobulin-secreting B cells (ISC) upon mitogenic stimulation with pokeweed mitogen (PWM) and concanavalin A (Con A). In supernatants of cultured PBMC of myeloma patients the spontaneous secretion of the type 1 cytokine interferon-gamma was reduced. After PWM stimulation reduced numbers of polyclonal ISC were found in 79% of patients, and monoclonal ISC were observed in 12% of patients. After Con A stimulation, again formation of polyclonal ISC was reduced, but monoclonal ISC were found in 41% of patients. Elevation of monoclonal and reduction of polyclonal ISC after stimulation with Con A were associated with an increase of CD8⁺ CD11b⁺ Leu-8⁻ T cells (P < 0.05). We conclude that the elevated numbers of CD8⁺ CD11b⁺ Leu-8⁻ T cells play a role in the stimulation of monoclonal and suppression of polyclonal immunoglobulin secretion in myeloma patients.     

大鼠生后发育期间胃肠道IAPP免疫反应细胞的分布

用免疫组织化学ＰＡＰ法显示正常Ｗｉｓｔａｒ大鼠生后发育期间胃肠道ＩＡＰＰ免疫反应细胞，观察其形态和分布。结果表明，ＩＡＰＰ－ＩＲ细胞随生后发育而发生变化。生后１ｄ，ＩＡＰＰ－ＩＲ细胞即可见于胃肠道各段。１８ｄ时在胃体部较多，４５ｄ及成年时小肠各段较多，ＩＡＰＰ－ＩＲ细胞位于上皮细胞间及固有膜结缔组织中。本实验结果提示，大鼠胃肠道各段ＩＡＰＰ－ＩＲ细胞在个体生后继续发生变化。本文对上述结果可能的生物     

VEGF、ANG-1、ANG-2、TSP-1的表达与胆管细胞性肝癌血管生成和侵润转移的关系

目的：研究血管内皮生长因子（VEGF）、血管生成素-1（ANG-1）、血管生成素-2（ANG-2）、血小板反应蛋白-1（TSP-1）的表达与胆管细胞性肝癌(CCC)血管生成和侵润转移的关系。方法： 对33例手术切除的CCC标本进行CD34、VEGF、 ANG-1、 ANG-2 和TSP-1的免疫组化染色，研究VEGF、ANG-1、ANG-2、TSP-1的表达与胆管细胞性肝癌血管生成和肿瘤门静脉侵犯、肝内转移、淋巴结转移以及肿瘤分化水平之间的关系。 结果： 本组CCC的微血管密度（MVD）为(87.2±52.6)/mm2，VEGF、ANG-1、ANG-2 和TSP-1的阳性率分别为75.6%、36.0%、57.6%和45.5%。VEGF和ANG-2的阳性表达与高MVD相关，TSP-1则与MVD负相关（P<0.01,P<0.05,P<0.01）。阳性TSP-1与肝内转移正相关（46.7% vs 5.6%，P<0.05）。结论： CCC瘤内的血管新生活跃，VEGF和ANG-2的阳性表达与CCC血管生成正相关，TSP-1则与其负相关，TSP-1的阳性表达还与肝内转移相关，VEGF、ANG-1、ANG-2的表达与肿瘤的侵润转移未见显著相关。     

不同分子量尿毒血清组分对人肾小管上皮细胞CTGF基因和蛋白表达的影响

目的：探讨不同分子量尿毒血清组分对人肾小管上皮细胞结缔组织生长因子（CTGF）基因和蛋白表达的影响。方法:无菌条件下收集40份尿毒症病人血清和20例正常人血清，应用Centricon Plus 20 Centrifugal Filter Devices将尿毒血清分离成分子量 >10 000 D，5 000-10 000 D，<5 000 D 3个组分。应用Western blotting方法检测CTGF的蛋白表达，RT-PCR方法检测CTGF mRNA表达。结果:2.5%-20%浓度尿毒血清组CTGF基因表达均明显高于正常对照组，以10%尿毒血清组最高；分子量 <5 000 D尿毒血清组CTGF基因表达与正常对照组差异无显著，而分子量 5 000-10 000 D和 >10 000 D尿毒血清组CTGF基因表达均高于正常对照组，以分子量 >10 000 D尿毒血清组最高。不同浓度尿毒血清组CTGF蛋白表达均高于正常对照组，且有随着尿毒血清浓度的升高而增高，在不同分子量尿毒血清组中，以分子量 >10 000 D组增高最为显著。结论：尿毒症毒素通过影响人肾小管上皮细胞致纤维化细胞因子CTGF基因和蛋白表达从而在人肾小管-间质纤维化中起重要作用，而以分子量大于 10 000 D的尿毒症毒素在其中起主要作用。     

CD8+T-bet+ cells as a predominant biomarker for inclusion body myositis

Background

Myositis is a heterogeneous group of muscular auto-immune diseases with clinical and pathological criteria that allow the classification of patients into different sub-groups. Inclusion body myositis is the most frequent myositis above fifty years of age. Diagnosing inclusion body myositis requires expertise and is challenging. Little is known concerning the pathogenic mechanisms of this disease in which conventional suppressive-immune therapies are inefficacious.

肝再生过程中肝和脑垂体纤维粘连蛋白表达的变化

目的；探讨大鼠肝大部分切除再生过程中肝和垂体内纤维粘连蛋白变化变化，方法：用免疫组织化学法观察鼠肝大部切除术０．５天，１天，１．５天，２天，３天，７天时，肝内和垂体远侧部滤泡状细胞细胞纤维粘连蛋白的变化，并用图像分析仪进行定量测定，结果：肝大部切除术后１．５天，肝内纤维粘连蛋白阳性染色增强，基平均光密度高于对照组（Ｐ〈０．０５）；术后２～３天，镜下可见纤维粘连蛋白染色呈强阳性，尤其在肝组织增生部位