准分子激光角膜切削术治疗高度、超高度近视眼术后角膜上皮下混浊的远期观察

目的:探讨准分子激光角膜切削术(PRK)治疗高度、超高度近视眼术后角膜上皮下雾状混浊(Haze)的发生情况及影响因素。方法:应用日本NIDEKEC-5000型准分子激光仪治疗高度、超高度近视眼143例(245眼),I组:-6.25～-10.00D,167眼;Ⅱ组-10.25～-24.00D,78眼。观察术后不同时期Haze的发生情况,随访7a以上。结果:术后3mo,0.5,1,4,7a,Haze的发生率,I组分别为74.8%,44.3%,24.5%,11.9%,7.8%;Ⅱ组为80.7%,52.1%,33.3%,24.3%,19.2%。7a时I组屈光度-0.57±1.84D,Ⅱ组-5.02±4.26D。有3级Haze7眼,I组2眼,为RK术后者;Ⅱ组5眼,4眼为年龄>40岁者。≥3级Haze者多出现在Ⅱ组,3～6mo达到高峰,持续时间达1a以上。结论:Haze为高度、超高度近视眼PRK术后的主要并发症。预矫屈光度越高,切削越深,则混浊程度越重;部分患者Haze逐渐减轻,角膜组织创伤修复时间长,部分重度Haze日后可能成为永久性瘢痕。     

临床瞳孔检查新进展

瞳孔每时每刻处于动态的变化之中,因此瞳孔的检查也是一个较为复杂的过程。随着对屈光手术质量要求的日益提高,特别是暗适应下瞳孔的大小往往在一定程度上可能决定着术后质量的好坏,因此暗适应下瞳孔的精确测量变得尤为重要。现对近年来涌现的瞳孔检查新技术作一简要概括。     

γD基因变异与青少年遗传性白内障发病的分子机制研究

目的 通过对一青少年遗传性白内障家系发病患者γD基因的分析，探讨该基因变异在白内障发病中的作用。方法 运用基凶扩增、克隆、变异分析的方法，研究该家族中不同患者γD基因的变异情况。结果 同一家族中5例患者出现3种不同核苷酸变异，个别核苷酸的突变并未引起编码氨基酸的改变。结论 同一家族不同自内障患者出现不同的γD基因变异现象为研究青少年遗传性白内障发病的分子机制提供了理论依据。     

Effect of ATP-potassium channel opener nicorandil on long-term cardiac preservation

BACKGROUND: ATP-sensitive potassium channels have been shown to be one of the important protective mechanisms for the ischemic myocardium. The purpose of this study was to evaluate the protective effect of nicorandil, an ATP-sensitive potassium channel opener, on myocardium during 6 hours hypothermic preservation. METHODS: Preserved rat hearts were randomly divided into 4 groups according to cardioplegia and preservation protocols as follows: (1) histidine-tryptophan-ketoglutarate solution (HTK) for both cardioplegic and immersing solutions (group A); (2) nicorandil-added HTK for cardioplegic solution and nicorandil-free HTK for immersing solution (group B); (3) nicorandil-free HTK for cardioplegic solution and nicorandil-added HTK for immersing solution (group C); and (4) nicorandil-added HTK for both cardioplegic and immersing solutions (group D). RESULTS: The recovery of postischemic cardiac function, including left ventricular developed pressure and end-diastolic pressure, was significantly improved in group B and group C as compared with the other groups (p<0.05). Postischemic intracellular calcium concentration was significantly lower in group B and group C than in group A (p<0.05). CONCLUSIONS: We concluded that nicorandil-induced hyperpolarizing arrest could reduce ischemia-derived myocyte injury and inhibit the influx of calcium into the myocytes in long-term cardiac preservation.     

Phylogenetic reconstruction of Mycobacterium tuberculosis within four settings of the Caribbean region: tree comparative analyse and first appraisal on their phylogeography.

In order to compare phylogenetic methods and to reconstruct the evolutionary history of the tubercle bacilli, a set of macro-array-based genotyping data of Mycobacterium tuberculosis clinical isolates (called spoligotyping for spacer oligonucleotide typing, which assays the variability of the Direct Repeat -DR- locus), was analyzed in four settings of the Caribbean region (Guadeloupe, Martinique, Cuba and Haiti). A set of 47 alleles, split into 26 shared and 21 unique alleles) representative of 321 individual M. tuberculosis clinical isolates from patients residing in the above regions was studied. The following methods (and software in brackets) were investigated: numerical taxonomy distance methods (TAXOTRON), maximum parsimony procedure (PAUP), median-joining networks (NETWORK), and nested clade analysis (GEODIS). Results using these methods were analyzed, compared and discussed. The latter method (GEODIS) was investigated in detail by introducing geographical data together with genetic variability results to detect a link between population structure and population history, and to test the null hypothesis of no association between geography and genotypes. Irrespective of the methods used, our findings demonstrate that a core structure of four families (or clades) of M. tuberculosis strains is highly prevalent within the islands studied, indirectly reflecting passed colonization history of these different settings. Specificity of M. tuberculosis genotypes in each of the islands is discussed in the light of their respective colonial and contemporary histories.     

β-内酰胺酶抑制剂研究进展

报道了4种β-内酰胺酶抑制剂(包括克拉维酸、舒巴坦、他唑巴坦以及BRL-42715)的特性、各抑制剂的复方制剂、作用 机制,以及这些酶抑制剂与不耐酶的β-内酰胺类抗生素联合应用后的协同作用,并对酶抑制剂抑酶作用进行了比较。     

益肾活血胶囊抗病毒性心肌炎的实验研究

目的　探讨益肾活血胶囊对病毒性心肌炎的治疗作用。方法　选用BALB/C小鼠 6 0只,随机分为正常对照组、模型组、益肾活血胶囊组、阳性药物组,每组分别给药后,测定LDH和AST含量,并进行组织病理学检测,各区测定值采用t检验进行组间比较。结果　益肾活血组小鼠LDH、AST水平较模型组明显降低,(p <0 0 0 1);组织病理学检测发现,心脏组织病理改变程度较模型组明显减轻。结论　益肾活血胶囊对于病毒性心肌炎模型小鼠有一定的治疗作用。     

高压氧预处理对宫内缺血缺氧大鼠脑组织及血浆神经肽Y含量的影响

目的 :探讨高压氧 (HBO)预处理对宫内缺血缺氧大鼠脑组织及血浆神经肽Y含量的影响。方法 :采用放射免疫法测定 2 5例正常胎鼠 (对照组 )、2 7例宫内缺血缺氧胎鼠 (缺血缺氧组 )及 1 9例经高压氧预处理宫内缺血缺氧胎鼠 (HBO组 )中枢及外周血神经肽Y的含量。结果 :HBO组胎鼠脑及外周血神经肽Y的含量分别为 52 .64±1 2 .1 6pg/mg及 1 99.51± 49.36ng/L ,缺血缺氧组胎鼠脑及外周血神经肽Y的含量分别为87.2 5± 2 3.63pg/mg及 2 51 .53±55 .2 8ng/L ,对照组胎鼠神经肽Y含量为 48.63± 1 0 .72pg/mg及 1 4 7.35± 31 .49ng/L ;与对照组相比 ,缺血缺氧组胎鼠中枢及外周神经肽Y含量均显著升高 (P <0 .0 1 ) ;HBO组神经肽Y含量显著低于缺血缺氧组 (P <0 .0 5)。结论 :神经肽Y与围生期缺血缺氧的发生密切相关 ,HBO预处理具有改善宫内缺血缺氧的作用 ,其机理可能与抑制神经肽Y的生成有关     

解密抑郁症

来自美国、瑞典及法国的科学家发现，有一种蛋白可能在抑郁症的发病过程中起着极为重要的作用。他们希望这一发现将有助于明确抑郁症的病因，找到新的治疗方法（Svenningsson P et al．Sc／ence．2006：311：77—80）。