pH Sensitivity of non-synaptic field bursts in the dentate gyrus

Under conditions of low [Ca(2+)](o) and high [K(+)](o), the rat dentate granule cell layer in vitro develops recurrent spontaneous prolonged field bursts that resemble an in vivo phenomenon called maximal dentate activation. To understand how pH changes in vivo might affect this phenomenon, the slices were exposed to different extracellular pH environments in vitro. The field bursts were highly sensitive to extracellular pH over the range 7.0-7.6 and were suppressed at low pH and enhanced at high pH. Granule cell resting membrane potential, action potentials, and postsynaptic potentials were not significantly altered by pH changes within the range that suppressed the bursts. The pH sensitivity of the bursts was not altered by pharmacologic blockade of N-methyl-D-aspartate (NMDA), non-NMDA, and GABA(A) receptors at concentrations of these agents sufficient to eliminate both spontaneous and evoked synaptic potentials. Gap junction patency is known to be sensitive to pH, and agents that block gap junctions, including octanol, oleamide, and carbenoxolone, blocked the prolonged field bursts in a manner similar to low pH. Perfusion with gap junction blockers or acidic pH suppressed field bursts but did not block spontaneous firing of single and multiple units, including burst firing. These data suggest that the pH sensitivity of seizures and epileptiform phenomena in vivo may be mediated in large part through mechanisms other than suppression of NMDA-mediated or other excitatory synaptic transmission. Alterations in electrotonic coupling via gap junctions, affecting field synchronization, may be one such process.     

大鼠下丘脑一氧化氮合酶（NOS）阳性神经元的分布

观察大鼠下丘脑各核团NOS阳性神经元的分布。采用还原型尼克酰胺腺嘌呤二核苷酸脱氢酶（NADPH－d）法，结果显示，大量NOS阳性神经元见于下丘脑外侧区、视上核（SO）和室旁核（Pa）；出现较多NOS阳性神经元的部位是视前大细胞核，见到少量NOS阳性神经元的部位是室周核、视前内侧区、视前外侧区和下丘脑前区。结论：NOS阳性神经元分布于下丘脑的许多核团。     

抗轮状病毒卵黄免疫球蛋白的蛋白酶水解及被动免…

用婴幼儿轮状病毒抗原免疫产卵母鸡，制备出抗婴幼儿轮状病毒鸡卵黄免疫球蛋白（抗－ＨＲＶＩｇＹ）同时研究抗－ＨＲＶＩｇＹ的抗人类胃酸屏障能力，抗消化道蛋白酶的酶解以及临床使用的安全性和效果，研究结果表明：抗－ＨＲＶＩｇＹ具有一定的抗胃酸屏障能力和抗消化道蛋白酶酶解作用，抗－ＨＲＶＩｇＹ安全无毒，对婴幼儿轮状病毒感染具有被动免疫保护作用。     

中枢性疲劳症候群临床与血清色氨酸的研究

目的：对珠海市中学生中枢性疲劳症候群的临床,患病率及与血清色氨酸的关系进行研究。方法：采用单纯随机抽样和整群一级抽样方法,对4年中学1594人进行问卷调查作为初筛,筛出有症状的部分人在医院进行以排除其它疾病为 的精查,并做血清色氨酸含量的测量,结果：临床表现自主神经症状,睡眠障碍,精神症状,推测珠海市中学生中患病率为11％,血清色氨酸含量较正常对照组低,两组有显著差异（P＜0．01）,结论：中枢性疲劳症候群是珠海地区中学生中的常见病,应积极于以防治;血中色氨酸含量的测定对诊断该疾病有一定的价值。     

端粒酶及nm23的表达与胃腺癌预后的关系探讨

目的 :探讨端粒酶和nm2 3癌基因蛋白表达与胃癌根治术后复发及预后的关系。方法 :采用端粒酶原位分子杂交技术及免疫组化S P法分别对 4 5例原发性胃腺癌组织中端粒酶的活性及nm2 3进行检测 ,并结合内镜及随访资料进行分析。结果 :胃腺癌端粒酶阳性表达率及nm2 3低表达率在有淋巴结转移组显著高于无淋巴结转移组 ;在术后 5年内复发者中显著高于无复发者。虽然随着胃腺癌分化程度的降低及浸润深度的增加 ,端粒酶活性及nm2 3低表达呈增强趋势 ,但其差异无统计学意义。结论 :胃腺癌组织中端粒酶的活性表达及nm2 3的低表达与淋巴结转移及术后复发显著相关 ,两者的表达变化对判断胃癌术后复发及预后判断有重要临床意义     

Establishment of in vitro cellular model predicting histocompatibity in allograft

Histocompatibility is crucial in effecting survivalof allografts.Due to differences in histocompatibilitybetween donor and recipient,rejection would happento some extent after transplantation. Therefore,theevaluation of differences in histocompatibility betweendonor and recipient would be contributive to selectionof donor and judgement on prognosis oftransplantation. HLA typing and mixed lymphocyticreaction (MLR) are the classical methods to evaluatethe histocompatibility between donor and r…     

鼻腔、鼻窦部砂粒性骨化纤维瘤6例临床分析

为探讨临床上比较罕见的砂粒性骨化纤维瘤（psammomatoid ossifying fibroma,POF）的临床特征、诊断与治疗方法,分析了6例POF的临床资料并综合文献,提出POF是一种以青少年为主、具有局部侵袭性的良性肿瘤,有明确的组织形态特征,临床症状特别是CT扫描是临床诊断的基础,治疗原则是在彻底清除病灶的基础上,兼顾面容与功能的保护。     

血管紧张素Ⅱ上调BaX表达诱导人内皮细胞凋亡

为了研究血管紧张素Ⅱ(AngⅡ)诱导凋亡的机制,将人脐静脉内皮细胞培养至第3代,用不同浓度Ang Ⅱ培养不同时间,用TUNEL检测细胞凋亡.Bax和Bcl-2蛋白表达用Western Blot和图像分析法测定.结果发现Ang Ⅱ组的凋亡阳性率极显著高于对照组;Bax的表达极显著地升高且具有时间和剂量依赖性,Bcl-2无显著变化,Bax/Bcl-2比值极显著地增加.提示AngⅡ通过诱导Bax的高表达,致Bax/Bcl-2比值极显著地增加而诱发凋亡.     

激光照射对小鼠骨髓细胞微核率的影响

目的　研究激光照射的生物效应。方法　采用低能量He Ne激光照射小鼠 ,每天 1次 ,每次 10min ,照射 7天后 ,处死小鼠。测定小鼠骨髓嗜多染红细胞微核的出现率。结果　经低能量He Ne激光照射的小鼠的细胞微核率与对照组比较无差异 (P >0 .0 5 )。结论　受低能量He Ne激光照射后小鼠骨髓嗜多染红细胞微核率无显著增加 ,治疗用低能量的He Ne激光不会致突变     

Secretions released from mesenchymal stem cells improve spermatogenesis restoration of cytotoxic treatment with busulfan in azoospermia mice

This study aimed at the efficacy of sequential treatment of bone marrow-derived mesenchymal stem cell secretion for busulfan-treated azoospermia in mice. The conditioned media (CM) was obtained from bone marrow mesenchymal stem cells (MSCs) or 293 cells. Chemically induced azoospermia mice received 200 μl MSC-CM or 293-CM twice a week intravenously for three consecutive weeks. The histological assessment of spermatogenic recovery quantifying the expression of meiosis-associated genes, and Sertoli cell barrier functional factors were assessed. The characteristics of TM4 cells (Sertoli cell line) after pre-incubation of MSC-CM in vitro were also obtained. The MSC-CM group had the most spermatogenic colonies among the three groups (p < .05), but no spermatids were seen. Expressions of the meiosis-associated genes Dazl, Vasa, Miwi, Stra8, CyclinA1, Pgk2 and Scp3 in MSC-CM testis were remarkably higher compared with 293-CM and busulfan groups respectively (p < .05). The levels of Sertoli cell barrier functional factors, for example ICAM-1 and N-cadherin, were significantly increased during MSC-CM treatment (p < .05). Moreover, pre-incubation of MSC-CM particularly accelerated the CD54 (ICAM-1) and CD44 expressions of TM4 cells and promoted cell inherent adhesion. MSC-CM treatment can significantly improve the short-term restoration of spermatogonial structures of chemically induced azoospermia related to facilitating Sertoli cell adhesion integrity.