慢粒白血病abl癌基因表达的研究

选择分别位于ｂｃｒ／ａｂｌ嵌合基因的Ｍｂｃｒｌ第二外显子和ａｂｌ的第二外显子上的两条引物，对１８例慢粒白血病及２例急淋白血病标本进行逆转录ＰＣＲ（ＲＴ－ＰＣＲ）检测。结果：在１８例包括ｐｈ（＋）和ｐｈ（－）不同病期的慢粒白血病患者血中均检出ｂｃｒ／ａｂｌ嵌合基因的表达，其中１４例为Ｋ－２８型表达，１例为Ｌ－６型表达，３例为Ｋ－２８型，Ｌ－６型同时表达；２例急淋白血病标本中１例为Ｋ－２８型表达。研究结果表明，１．ｂｃｒ／ａｂｌ嵌合基因是慢粒白血病的一个重要分子生物学特征；２．ｐｈ（＋）和ｐｈ（－）慢粒白血病的分子生物学基础相同，即均有ｂｃｒ／ａｂｌ嵌合基因；３．至少部分急淋白血病与慢粒白血病有相同的分子生物学基础；４．ｂｃｒ的断裂点位置可能有一定的临床意义，但有待进一步研究；５．同时表达Ｌ－６型和Ｋ－２８型的情况多见于急变区，此现象提示体内可能同时有两类不同嵌合的白血病细胞或白血病急变期ｂｃｒ出现新的重排。     

A cation binding motif stabilizes the compound I radical of cytochrome c peroxidase.

Cytochrome c peroxidase reacts with peroxide to form compound I, which contains an oxyferryl heme and an indolyl radical at Trp-191. The indolyl free radical has a half-life of several hours at room temperature, and this remarkable stability is essential for the catalytic function of cytochrome c peroxidase. To probe the protein environment that stabilizes the compound I radical, we used site-directed mutagenesis to replace Trp-191 with Gly or Gln. Crystal structures of these mutants revealed a monovalent cation binding site in the cavity formerly occupied by the side chain of Trp-191. Comparison of this site with those found in other known cation binding enzymes shows that the Trp-191 side chain resides in a consensus K+ binding site. Electrostatic potential calculations indicate that the cation binding site is created by partial negative charges at the backbone carbonyl oxygen atoms of residues 175 and 177, the carboxyl end of a long alpha-helix (residues 165-175), the heme propionates, and the carboxylate side chain of Asp-235. These features create a negative potential that envelops the side chain of Trp-191; the calculated free energy change for cation binding in this site is -27 kcal/mol (1 cal = 4.184J). This is more than sufficient to account for the stability of the Trp-191 radical, which our estimates suggest is stabilized by 7.8 kcal/mol relative to a Trp radical in solution.     

Subtypes of alpha 1-adrenoceptors in rat blood vessels

Two alpha 1-adrenoceptor subtypes (alpha 1A and alpha 1B) have been distinguished by competitive antagonists and the alkylating agent chloroethylclonidine. The chloroethylclonidine-insensitive subtype (alpha 1A) has been suggested to selectively activate Ca2+ influx through dihydropyridine-sensitive channels in smooth muscle. We compared the effects of chloroethylclonidine and nifedipine on contractile responses to norepinephrine (NE) in rat blood vessels. Pretreatment with chloroethylclonidine caused a large shift to the right and decrease in maximum for NE-induced contractions of rat aorta, however, nifedipine had no effect in this tissue. Chloroethylclonidine had no effect on NE-induced contractions of rat renal arteries, which were almost completely abolished by nifedipine. Both chloroethylclonidine and nifedipine partially attenuated NE-induced contractions in rat mesenteric artery and portal vein. Addition of nifedipine abolished residual contractions remaining after chloroethylclonidine pretreatment in all four types of vessels. The pA2 for the competitive antagonist WB 4101 was highest in renal artery and lowest in aorta. These results suggest that the sensitivity of rat blood vessels to chloroethylclonidine is inversely related to their sensitivity to nifedipine, and support the existence of two alpha 1-adrenoceptor subtypes in rat blood vessels. Rat aorta appears to contain primarily alpha 1B receptors, renal artery primarily alpha 1A, and mesenteric artery and portal vein mixtures alpha 1A of and alpha 1B.     

鼻内法鼻泪管阻塞切除术

本文介绍了鼻内法鼻泪管逆行切除术的切除器制备、应用器械、手术方法及术后处理。并应用本法治疗慢性泪囊炎１０６例１１３眼，术后随访１￣５年，痊愈９３．８％，无效６．２％。     

壳聚糖作为中枢神经系统支架材料的可行性研究

目的探索壳聚糖作为中枢神经系统组织工程支架材料的可行性。方法选择孕14～16dWistar大鼠剖宫取胎鼠脑进行分离、培养,经巢蛋白、胶原纤维酸性蛋白、特异性烯醇化酶和半乳糖脑苷酯免疫细胞化学染色鉴定获得神经干细胞,种植于壳聚糖膜和明胶膜表面培养,然后行巢蛋白免疫细胞化学染色,观察神经干细胞在壳聚糖膜和明胶膜表面的贴附、生长和分化状态,以及壳聚糖、明胶的降解速度。结果从胎鼠大脑分离获得的神经干细胞,巢蛋白染色呈阳性反应,可分化形成神经元和胶质细胞,分化细胞分别呈胶原纤维酸性蛋白、特异性烯醇化酶和半乳糖脑苷酯染色阳性反应。神经干细胞接种后12h即贴附于壳聚糖膜表面,24h壳聚糖膜和明胶膜均贴附牢固;48h明胶膜表面神经球周围首先出现带突起的分化细胞,壳聚糖膜迟至生长第3天才出现。神经干细胞接种生长后第3天,壳聚糖膜部分降解,明胶膜完全降解;第4天膜表面长满分化细胞;第5、6天壳聚糖膜大部分降解,分化细胞部分死亡。结论壳聚糖与神经干细胞生物相容,具有促细胞贴附和分化作用,由于机械性能差,不宜作为中枢神经组织工程的结构性生物支架材料,但可以单独或者联合促贴附物明胶作为促神经干细胞贴附和分化的支架表面修饰剂。     

TIA对后继脑梗死神经保护作用的临床研究

目的探讨预先短暂性脑缺血发作(TIA)是否对后继脑梗死具有神经保护作用。方法根据脑梗死患者是否预先发生同侧的TIA分为TIA组和无TIA组,分别从TIA持续时间、发作次数、与脑梗死间隔时间及梗死部位几方面同无TIA组比较,采用ADL评分标准,评定患者预后恢复情况。结果Ⅰ级预后预先有TIA的占72%,无TIA的占63%,二者相比差异无显著性(X~2=3．31,P＞0．05)。但脑梗死前有TIA且持续时间在5～20min、发作次数2～3次,与脑梗死间隔不超过1周者,其Ⅰ级预后较多,同无TIA组相比较差异有显著性(P＜0．05)。结论脑梗死前发生的TIA有可能对人脑产生缺血耐受作用。TIA的神经保护性与其发作持续时间、发作次数及与脑梗死间隔时间有一定关系。     

脑利钠肽在评价功能性单心室患者TCPC后心功能中的价值及意义

目的探讨脑利钠肽(BNP)在评价功能性单心室患者行全腔静脉-肺动脉连接术(TCPC)后心功能中的价值及其意义。方法选择2004年4~11月间连续在我科随访的TCPC后患者11例(TCPC组),男7例,女4例;年龄8.2±4.1岁;随访时间2.1±1.6年。按照改良R oss标准对临床心功能评分。采集外周静脉血3m l,用酶标免疫法测定血浆BNP浓度。其中6例同期用磁共振成像(M R I)测定心功能,对BNP做相关因素分析。9人健康儿童作为正常对照(对照组)。结果(1)TCPC组血浆BNP水平为400pg/m l(IQR 200-690),较对照组的110 pg/m l(IQR 90-190)增高(P=0.003);(2)M R I测定结果:TCPC组6例患者舒张期末容量指数为65.76±8.65 m l/m2,收缩期末容量指数为31.90±6.36 m l/m2,心搏出量指数为39.09±11.76 m l/m2,射血分数(EF)为0.52±0.06,心脏指数(C I)为2.38±0.58 L/m in.m2,心肌质量指数为103.49±21.57 g/m2,心肌质量/心室舒张期末容量为1.57±0.24;(3)TCPC组BNP水平与手术时年龄呈明显正相关(r=0.632,P=0.041);BNP水平与上述M R I指标、R oss评分、性别、年龄、脉搏血氧饱和度(SpO2)及主心室类型等因素无关。结论TCPC后近2年神经内分泌系统仍处于应激状态,BNP增高可能与TCPC后特有的血流动力学状态有关;血浆BNP水平不能作为正确评估TCPC后心功能状态的指标。     

妇科阴道流血的鉴别及护理对策

目的探讨有关阴道异常流血的鉴别及有关护理的问题.方法在护理工作中通过对妇科异常阴道流血的原因进行分析鉴别,并采取相应的护理措施.结果总结出针对性护理方面的异同点.结论对提高护士的护理诊断能力,加强工作的计划性和预见性,及时做好急救准备有着重要的意义.     

急性脑卒中患者应激性高血糖危险因素分析

目的 探讨重症监护室（ICU）急性脑卒中患者应激性高血糖的危险因素。方法对50例急性（发病5d内1非糖尿病脑卒中患者监测血糖7-14d，比较高血糖及正常血糖两组患者年龄、糖皮质激素、临床肺部感染评分等对血糖的影响。结果高血糖组临床肺部感染评分（CPIS）为4．77±2．11，显著高于正常血糖组的3．36±2．36（P〈0．05），急性生理学及慢性健康状况评分（APACHEⅡ）高血糖组为16．23＋5．40，也显著高于正常血糖组的12．43±3．83，有显著性差异（P〈0．01）。结论CHS和APACHEⅡ升高可能是ICU非糖尿病卒中后应激性高血糖的危险因素。     

腹腔镜在胃癌根治术的应用进展

近年来有关早期胃癌的微创治疗进展很快，并已取得国内外的共识。对进展期胃癌应用腹腔镜行胃癌根治术尽管已经取得了较好的临床效果，但仍尚待前瞻性多中心临床随机对照研究。从应用前景看，随着术者技术的完善、观念的改变、经验的积累、手术器械的不断改进，腹腔镜胃癌根治术必将在胃癌手术中扮演越来越重要的角色。