Cytoprotective effect of epidermal growth factor on acid- and pepsininduced damage to rat gastric epithelial cells: Roles of Na+/H+ exchangers

We have previously established a cell damage model, with damage induced by either acid or pepsin treatment for 30 min, involving a rat gastric epithelial cell line (RGM1). In the present study, pretreatment of cells with epidermal growth factor (EGF; 0.1–10ng/mL) or sucralfate (0.1–3 mg/mL) for 4 h prevented such cell damage in a concentration-dependent manner. Protection of cells by these drugs was not affected by pretreatment with indomethacin (10⁻⁵ mol/L) for 4 h. Removal of Na⁻, but not Ca²⁺, from the acidified medium totally abolished the inhibitory effect of EGF, but not that of sucralfate. Genistein (a tyrosine kinase inhibitor) apparently reduced the inhibitory effect of EGF. DNA synthesis by RGM1 cells did not increase when cells were incubated with EGF for 4 h. We conclude that both EGF and sucralfate protect RGM1 cells from acid- and pepsin-induced damage and that the mechanism of protection by EGF against acid-induced damage seems to be via activation of Na⁺/H⁺ exchangers.     

Anti-inflammatory effect of β2-agonists: Inhibition of TNF-α release from human mast cells

β₂-Agonists inhibit the release of preformed mediators such as histamine and newly synthesized mediators such as prostaglandin D₂ from mast cells. However, although mast cells have been identified as an important source of several cytokines including tumor necrosis factor-α (TNF-α), there is no information about their regulation by β₂-agonists. Thus given the importance of TNF-α in inflammation and the widespread use of β₂-agonists, we investigated the effect of long-acting (salmeterol) and short-acting (salbutamol) β₂-agonists on the secretion of TNF-α from human skin mast cells. Treatment of mast cells with salmeterol or salbutamol (100 nmol/L) inhibited the IgE-dependent release of TNF-α (82% and 74%, respectively). Moreover, 2-hour treatment with salmeterol, isoproterenol, or salbutamol inhibited mast cell cytotoxicity against a TNF-α–sensitive cell line, WEHI-164, with an IC₅₀ of 71, 50, and 29 nmol/L, respectively. Specificity for β-adrenergic receptors was shown with propranolol. The inhibitory effect of β₂-agonists was observed after only 20 minutes of treatment but was lost by 24 hours after removal of salbutamol and isoproterenol (7% and 11% inhibition remaining, respectively). In contrast, the inhibition of TNF-α release was increased 1 hour after removal of salmeterol and remained significant 24 hours later. Furthermore, β₂-agonists did not show tachyphylaxis for the inhibition of TNF-α release. Thus selective β₂-agonists demonstrate anti-inflammatory activity by inhibiting the release of TNF-α from mast cells stimulated through their IgE receptor or by a tumor target cell. This inhibitory effect of β-agonists may be important in their mode of action in the treatment of allergic diseases. (J Allergy Clin Immunol 1997;100:825-31.)     

大白鼠肾上腺的血管构筑

本实验采用血管铸型扫描电镜,注射明胶卡红组织切片显微镜下观察和注射铅丹乳胶追踪血管来源三种方法对14只健康大白鼠肾上腺血管构筑进行了研究。大白鼠肾上腺动脉发自腹主动脉和肾动脉。它们在行程中发出分支至腺体表面,再次分支穿入囊内,逐级分支至毛细血管。皮质动脉发自囊内血管,它们在皮质中分支分布。球状带的毛细血管与囊的毛细血管相连,毛细血管在球状带围绕细胞团形成网眼状;在束状带呈放射状排列;在网状带吻合增多形成网状。髓质动脉亦发自囊的血管,它们在皮质中不发分支直抵髓质,在髓质分成毛细血管。网状带的毛细血管越向髓质口径越粗,它们在皮髓交界处互相吻合形成更粗的静脉,这些静脉逐级吻合,最后形成一主干——中央静脉,它穿出皮质出现于肾上腺门处。左侧的中央静脉注入在肾静脉,右侧的注入下腔静脉。     

Influence of peripheral afferents on cortical and spinal motoneuron excitability.

The objective of this study was to establish to what extent muscle, cutaneous, and joint afferents alter the excitability of spinal and cortical motor neurons. This question was examined by studying the impact of electrical stimulation of the second and third digits, the median nerve at the wrist, and the recurrent thenar motor branch on the F/H and magneto-electrical cortical motor responses (MEPs) of the thenar muscles. The firing frequencies of single F/H motor unit action potentials were unaltered by the foregoing conditioning peripheral stimuli. MEPs conditioned by motor threshold stimulation of the median nerve at the wrist or the recurrent motor branch were significantly increased in size at conditioning to test intervals of 50 to 80 milliseconds. No significant change in MEP size resulted from conditioning stimulation of the digital nerves. We conclude that muscle afferents were primarily responsible for the increase in MEP size. Conditioning stimuli may allow examiners to assess central motor conduction where it would otherwise be impossible.     

踝/肱指数对下肢动脉硬化性闭塞症缺血程度的评价

目的：利用检测下肢动脉硬化性闭塞症患的踝/肱指数对其下肢缺血程度进行评估。方法：采用以色列Flo-link 500T血管多普勒诊断仪对我院50例确诊为下肢动脉硬化性闭塞症患进行了分组踝/肱指数的检测。结果：踝/肱指数在0．5—0．9之间，常提示下肢动脉或近端有单水平阻塞；踝/肱指数在0．45以下常提示患下肢缺血程度严重，为坏疽前期静息痛表现；踝/肱指数在0．30以下多伴有缺血性溃癌或坏死。结论：踝/肱指数的检测可以反映下肢缺血程度，指导临床选择治疗方法，判断愈后及疗效，其无创性、可重复性、价格低康，更易被患接受。     

输卵管绝育术后并发异位妊娠病因及其防治的探讨

本文总结我院２０年中输卵管绝育术后并发异位妊娠的有关临床资料，主要以陈旧性宫外孕为其临床特征，仍以停经、腹痛、阴道出血为主要症状，对绝育术致宫外孕的有关因素及其预防进行了分析探讨。     

HIV/AIDS病人预防和治疗结核病双重感染的研究

目的调查HIV/AIDS病人结核菌素(PPD)试验反应状况及与免疫系统受损程度的联系,并探讨其预防和治疗结核病的意义。方法采用前瞻性病例对照研究方法,对40例HIV(+)者和202例HIV(-)者做结核菌素试验,并对HIV(十)者做CD4、CD8细胞计数测定,对HIV(+)分组服药,观察胸部病变情况。结果HIV(+)与HIV(-)者PPD阳性率分别为12.5%、28.2%(P<0.05)。当CD4细胞计数下降时,PPD反应减弱。CD4<200个/mm3时PPD均无反应(0×0).病例服药组经化学药物预防治疗后其肺部病变异常率小于病例对照组。结论HIV(+)者中PPD阳性率显著低于HIV(-)者。CD4细胞数下降可能是艾滋病并发结核的主要原因.对HIV/AIDS患者使用化学药物预防和治疗结核是有效的。     

脉冲式电磁辐射对大鼠血脑屏障影响的量效关系

目的 研究脉冲式电磁辐射(EMR)对大鼠血脑屏障(BBB)影响的量效关系。方法 采用伊思蓝静脉注射，荧光显微镜下观察不同脉冲次数的EMR辐照对大鼠BBB开放的影响。结果 伊思蓝在EMR诱发的大鼠BBB开放局部呈现荧光斑；随着EMR脉冲次数(0～200次)的增加，荧光斑数量增加、面积增大；荧光斑在EMR组全脑的分布，以皮质、丘脑、下丘脑、小脑、尾壳核和延髓较多。结论 不同脉冲次数EMR诱发大鼠BBB开放程度不同，随脉冲次数增加，血管通透性增强，200次时达开放高峰，皮质区BBB开放最明显。     

人精液中ABH血型物质分泌强度的研究

本文采用中和试验、沉降反应和解离试验对１３５例已知血型人精液中ＡＢＨ血型物质的分泌强度进行了检验，并将其分为强、中、弱三型。这对区别个人血型物质含量及性犯罪的法医学鉴定均有重要意义。并证明了ＡＢ型人精液中Ａ、Ｂ血型物质含量不均等现象，并且绝大多数人Ｂ型物质高于Ａ型物质。