Effect of gradual rise in plasma calcium concentration on the impairment of atrioventricular nodal conduction due to verapamil

The possible reversal by calcium of the inhibitory action of verapamil on the atrioventricular (AV) node was investigated in anesthetized, atropinized dogs, with cardiac pacing. The His bundle potentials were recorded by endocavitory electrode and the AV node effective refractory period measured by the extrastimulus method. Calcium infusion was effective against the impairment of AV nodal conduction induced by verapamil, provided it remained moderate: the gradual rise in the plasma calcium concentration counteracted the effects of an infusion of verapamil on conduction time and effective refractory period in the AV node, as long as it did not exceed 5 mmol/L. However, beyond this level, calcium appeared less and less capable of reversing the effects of verapamil. Thus, the protective action of calcium had a bell-shaped dose-response curve, with the optimum at 5 mmol/L. This biphasic influence is consistent with the opposite opinions previously given concerning the antagonism between calcium and calcium blockers, depending on whether hypercalcemia brought into play was mild or major. In any case, the prominent role played by calcium in the slow inward current in the AV node accounts for the antagonism, observed in vivo, between calcium and verapamil. The pacemaker activity of the sinoatrial (SA) node was less influenced by both calcium blocker and calcium.     

复方华蟾胶囊抗小鼠肿中瘤作用的实验研究

目的了解复方华蟾胶囊抗小鼠移植性肿瘤的作用.方法以小鼠肝癌22(H22)、小鼠肉瘤180(S180)为瘤株,应用动物移植性肿瘤的体内试验法对药物进行抗癌药效学试验.结果复方华蟾胶囊灌胃4,2 g/kg@d,连续14 d,对小鼠移植性肝癌实体型生长有明显的抑制作用,抑瘤率分别为38.09%,30.95%.对小鼠移植性S180实体型生长有明显的抑制作用,抑瘤率分别为34.7%,30.08%.复方华蟾胶囊对荷瘤小鼠的胸腺和脾脏重量无影响.结论复方华蟾胶囊在试验条件下有一定抗肿瘤作用.     

CT-脑立体定向手术的临床应用

目的 评价CT－脑立体定向手术的临床应用价值。方法 应用CT－脑立体定向仪完成28例次脑立体定向手术，分析其临床诊疗效果。结果 立体定向活检术10例，术后病理诊断明确；定向开放手术12例，病灶一次切除；立体定向穿刺分流术6例，术后症状改善明显。手术均一次成功，无手术并发症。结论 CT－脑立体定向手术能精确定位，确定最佳手术路径，为颅内多种疾患的诊断和治疗提供新的方法。     

Phase-constrained data extrapolation method for reduction of truncation artifacts

The authors present an improvement to a sigma-filter extrapolation method for the reconstruction of magnetic resonance (MR) images from symmetric discrete Fourier data. By making use of the phase information in the image data, the proposed method can overcome the data inconsistency problem of the original method for handling MR image data with large phase variations, such as those obtained in gradient-echo pulse sequences. Reconstruction results show that its performance is comparable with that of the modified complex sigma-filter method proposed previously to handle the inconsistency problem. However, the new approach has the advantage of reducing computation time by a factor of two with use of a sigma filter applied to real instead of complex images. It is expected that this method will be more practical for use in clinical MR imaging systems.     

Functional recognition of the neuronal tyrosine hydroxylase cAMP regulatory element in different cell types.

Transient transfection of pLB2CAT constructs bearing short synthetic oligonucleotides derived either from the tyrosine hydroxylase (TH) promoter or other sources was used to examine functional cAMP regulatory element (CRE) activity in a variety of cell lines. The region containing only the putative TH CRE was found to be as or more effective in conferring cAMP responsiveness onto pLB2CAT (which employs the TK promoter) than the immediate 272 bp region of the TH promoter. Increases in CAT activity of 10- to 20-fold were observed in JEG-3 cells with a single insert of the TH CRE region (-31 to -54) in pLB2CAT, and the presence of a second insert generated only a modest further increase. This construct also responded to cAMP in 4 other cell lines tested but the degree of increase was less dramatic. Inserts containing the consensus 8 bp CRE motif embedded in other natural or artificial contexts served generally as weak functional CREs in all cell lines tested. In vitro analysis revealed that a specific protein-DNA complex apparently containing a single protein with a MW of 45-50 kDa was formed equally well with JEG-3 cell nuclear extract and CRE-bearing-TH and other fragments which produced dramatically different cAMP effects in vivo. These results suggest specificity in the effects of cAMP on different CREs which are dictated by contextual differences.     

国产头孢三嗪在急性感染病人中的药代动力学

静脉滴注国产头孢三嗪0.5～1克,治疗8例急性感染病人的药代动力学。静注后半小时用HPLC测得的平均血药浓度为100.75μg/ml,24小时的血药浓度为11.4μg/ml,国产头孢三嗪的药代动力学特点与国外同类产品基本一致。半衰期长,清除半衰期为8.8小时,可在血液和感染部位中保持较长时间的杀菌和抑菌浓度,总表观分布容积为13.0L/kg,表明药物在组织中的浓度高。本品用量小,每日1克1～2次即可达到疗效。5例慢性胆囊炎伴胆石症患者静滴头孢三嗪1克后,2小时胆汁的平均药物浓度为1022.8μg/ml,可作为治疗胆道感染的有效药物。     

我国医院医学装备的建设和管理第十二讲医学装备管理的有关事项(第五部分)

医院设备的使用管理，是指设备从到货起，经过验收入库、出库发放．财产账目、技术档案、使用率调查等一系列程序，直至设备报废为止这一全过程的管理。购置设备物质运动的全过程中．使用所占的时间最长．所以使用管理是一重要的环节。这个环节的任务，可以概括为两个方面：一是保证设备的安全，包括数量上的准确性和质量上的完好性，以便完整地保持其使用价值；二是提高设备的使用率，充分发挥设备的医疗效果，追求更多的社会效益和经济效益。医院设备的使用管理，主要包括以下内容。     

大肠肿瘤组织中EB病毒的原位杂交检测

目的：探讨EB病毒感染与人大肠癌发生的关系。方法：用原位分子杂交法对130例人大肠癌标本中EB病毒小分子RNA片段进行检测。结果：130例标本中有6例（4.48％）癌组织呈阳性反应，其中4例为男性，4例有明显淋巴细胞浸润。结论：EB病毒感染可能与我国部分大肠腺癌的发生有关，肿瘤细胞间质中大量淋巴细胞浸润可能是EB病毒感染的重要病理学特征。     

MMP-9和TIMP-1表达失衡与乳腺癌浸润、转移的相关性

目的 研究乳腺癌组织中基质金属蛋白酶（MMP－9）和金属蛋白酶组织抑制因子（TIMP－1）的表达变化与乳腺癌生物学行为及淋巴结转移的关系。方法 应用SP免疫组织化学方法检测85例乳腺癌组织MMP－9，TIMP－1及细胞增殖核抗原ki-67的表达情况。结果 MMP-9阳性染色率90．59％，MMP－9阳性表达与肿瘤浸润，淋巴结转移，ki-67指数及TNM分期呈正相关（Pearson列联系数分别为P=0.03,P=0.02,P=0.004和P＝0．0000，P＜0．05，0．01。TIMP－1阳性染色率为78．82％，TIMP－1阳性表达与肿瘤浸润，淋巴结转移及TNM分期浸润，转移及ki-67指数显著相关（P＜0．05，P＜0．01，P＜0．001）。结论 MMP－9和TIMP－1表达失衡与乳腺癌浸润及淋巴结转移密切相关。