Active catabolism of glucocorticoids by 11 beta-hydroxysteroid dehydrogenase in vivo is a necessary requirement for natural resistance to infection with Listeria monocytogenes

The results from the present study demonstrate that the innate defense mechanisms which control the progressive growth of Listeria monocytogenes in normal animals in vivo are dependent upon the active catabolism of endogenous glucocorticoids by the enzyme 11 beta- hydroxysteroid dehydrogenase (11 beta-HSD). When 11 beta-HSD activity was pharmacologically inhibited in vivo, host susceptibility to progressive bacterial disease was markedly increased. Depressed natural resistance following 11 beta-HSD inhibition correlated with changes in the patterns of inducible cytokines by macrophages and T cells. Similar changes were observed when normal adult animals were treated with low doses of dexamethasone prior to experimental infection with Listeria.      

Skewing of TCR V genes to CD4+ and CD8+ subsets of T lymphocytes is not determined by amino acid composition of CDR3

TCR V genes show differing expression patterns, termed skewing, in CD4+ and CD8+ subsets of T lymphocytes. To determine which elements of the TCR V regions contribute to these observed TCR V gene skewing patterns, we have performed an in-depth analysis, taking advantage of RT-PCR and DNA sequencing, which was focused on the multi-member TCRBV6 gene family. These studies allowed us to evaluate the contributions of the various elements, that constitute the TCR beta chain variable region, to the observed TCR V gene skewing patterns. The results of these analyses revealed that within the TCRBV6 family individual members exhibited differing skewing patterns, i.e. TCRB6S7 was significantly skewed towards the CD4+ T cell subset, whereas TCRBV6S5 was significantly skewed towards the CD8+ subset. Scrutiny of the usage of TCRBV6 family members in combination with TCRBJ gene usage and amino acid composition of CDR3 did not reveal obvious structural characteristics which would explain the differing skewing patterns between TCRBV6S7 and TCRBV6S5. Further examination of these TCR V regions showed that the CDR1 and 2 regions within these TCRBV elements were composed of different amino acids. These observations suggests that these components contribute to the observed TCR V gene skewing patterns.      

反相高效液相色谱法测定二乙烯三胺五醋酸注射液的含量

目的:研究二乙烯三胺五醋酸三钠锌盐及三钠钙盐注射液的离子对高效液相色谱测定。方法:以ODS(5μm,5mm×150mm)为色谱柱,流动相为甲醇-0.05mol/L醋酸钠缓冲液(pH4.5)(5:95),内含5mmol/L四丁基碘化胺,内标物为乙二胺四乙酸二钠,二乙烯三胺五醋酸(DTPA)及乙二胺四乙酸,(EDTA)与Fe~(3 )螯合成DTPA-Fe(Ⅲ)和EDTA-Fe(Ⅲ)复合物,其检测波长为280nm。结果:二乙烯三胺五醋酸的线性范围在20～320μg/ml,其三钠锌盐和三钠钙盐注射液5次测定的平均回收率±RSD分别为(101.33±0.65)％和(100.59±0.58)％。结论:此法重现性好,灵敏、特异,消除了多种金属离子的干扰。     

微囊化兔嗅球组织移植对脊髓损伤大鼠细胞凋亡的影响

目的:观察微囊化兔嗅球组织细胞移植对大鼠脊髓全横断损伤后细胞凋亡及功能恢复的影响,并探讨其对脊髓继发性损伤的保护作用及其机制。方法:实验于2004-10/2005-07在南昌大学基础医学院应用解剖研究室完成。选择清洁级SD大白鼠120只,按随机数字表法分为4组:正常对照组、损伤对照组、单纯细胞悬液移植组、微囊化移植组,每组30只。制作T10节段脊髓全横断损伤模型。正常对照组仅打开椎管,暴露脊髓不作移植;损伤对照组仅用明胶海绵填塞脊髓损伤腔隙;单纯细胞悬液移植组植入吸附细胞悬液的明胶海绵块;微囊化移植组用与断端腔隙大小相吻合的明胶海绵块吸附10μL的微囊化细胞,植入洞腔。分别于术后12h,1,3,7,21d5个时间点对动物进行BBB评分后处死。取损伤区1cm范围脊髓节段,常规石蜡包埋,水平切片进行苏木精-伊红染色、TUNEL染色,观察凋亡细胞的数量及分布变化。按BBB评分法对大鼠术后运动功能的恢复情况进行评分,共分22级,最低分0分,最高分21分,分数越高,运动功能恢复越完善。结果:纳入大鼠120只,存活96只,存活率为80%。其中以损伤对照组及单纯细胞悬液移植组死亡率较高,损伤对照组大鼠死亡的主要原因可能是脊髓损伤导致损伤平面以下神经功能的丧失所引起的一系列并发症所导致的;而单纯细胞悬液移植组是因为免疫排斥反应所导致。①术后3d内各组间BBB评分差异无显著性意义(P>0.05);术后7,21d微囊化移植组和单纯细胞悬液移植组大鼠BBB评分高于损伤对照组,差异均有显著性意义[分别为(7.25±1.17),(4.58±0.38),(2.67±0.61)分;(10.42±1.63),(6.08±0.80),(3.33±0.68)分,F=4.528,3.821,P<0.05],且经微囊化处理后比单纯兔嗅球组织细胞悬液移植运动功能恢复更好(F=4.112,P<0.05);而损伤对照组大鼠后肢运动功能恢复均较差。②光镜下损伤对照组、单纯细胞悬液移植组脊髓损伤后,脊髓内空洞增大,损伤范围基本确定,周围有炎性细胞浸润;在微囊化移植组脊髓损伤明显减轻,细胞皱缩不明显、胞质、胞核较清晰。③术后1,3,7d微囊化移植组TUNEL阳性细胞数及凋亡指数低于损伤对照组,差异有显著性意义(以术后3d为例,TUNEL阳性细胞数分别为(8.83±1.33),(14.50±1.05)个/视野,P<0.01;凋亡指数分别为10.45±1.58,17.06±1.23,P<0.01)。结论:微囊化兔嗅球组织细胞移植对大鼠脊髓全横断损伤后细胞凋亡具有保护作用,能促进脊髓功能的恢复。     

低压细胞灌注法提高多孔人工骨成骨能力的体外研究

目的：多孔生物材料中心部所存在的气泡有可能限制了细胞和培养液进入中心部,从而限制了材料内细胞的进一步增殖和分化,继而影响移植后的体内骨形成.实验设计使用低压方法排除多孔材料生物材料β-TCP内的气泡,检测细胞/β-TCP复合体的成骨能力,以验证其可行性. 方法：实验于2003-04/2005-06在东京医科齿科大学医学部骨科实验室完成.在体外培养扩增骨髓间充质细胞后,将细胞置于成骨分化的培养液中,通过常压（大气压,101.1 kPa）和低压（13.3 kPa）两种方法将细胞灌注种植入72个多孔β-TCP人工骨中.细胞种植后检测β-TCP人工骨内含有的细胞悬浊液量,细胞生存率和细胞种植效率;应用扫描电镜观察细胞种植后人工骨内细胞附着情况.并在继续细胞分化培养1,2,3,4周时检测人工骨的DNA含量和碱性磷酸酶活性. 结果：①低压组人工骨的细胞悬浊液量、全细胞种植效率和活细胞种植效率均高于常压组（P＜0.01）;两种方法细胞种植后的细胞生存率没有明显不同（P＞0.05）.②扫描电镜观察显示低压组人工骨内附着更多的骨髓间充质细胞.③低压组细胞分化培养过程中不同时点的人工骨碱性磷酸酶活性和DNA含量均高于常压组（P＜0.01）. 结论：13.3 kPa低压细胞灌注法可以明显提高多孔人工骨的细胞种植和成骨能力.低压细胞种植法是一个既简单方便又实用有效的方法.     

基础神经心理学及其临床应用

目的:通过对脑的功能组织与心理活动(基本原则),脑的局部系统及其功能,心理过程及其脑机构的分析,进一步明确基础神经心理学对临床诊断、治疗及康复的意义。资料来源:通过检索中国期刊全文数据库1994-01/2006-05、荷兰Elsevier公司期刊数据库1984-01/2006-05和美国EBSCOhost数据库1984-01/2006-05中Academic Source Premier和MEDLINE两个子数据库中的与基础神经心理学及其临床应用相关的文献,检索词为“neuropsychology,clinic alapplication”,并限定语言种类为英文,同时手工检索与之内容相关的书籍。资料选择:脑功能组织与功能系统的基本关系及在临床上的应用文章。纳入标准:脑区与功能的联系;排除标准:只谈脑区而无功能联系的文章。资料提炼:纳入30篇符合标准的文献。资料综合:脑是一个复杂的高度集成的神经组织,与它能执行各种复杂的心理活动相辅相成。目前,研究神经心理的脑组织和功能的方法已经多样化,可以更逼真地观察和了解临床上的多种神经心理障碍及其病变机制,为临床治疗康复提供了极大的帮助。结论:各种神经心理学理论和观点正在逼进脑和脑功能的真实联系;在临床上的应用也会更加广泛,又反过来推动神经心理学的发展。     

Genome-wide genetic investigation of serological measures of common infections

Populations and individuals differ in susceptibility to infections because of a number of factors, including host genetic variation. We previously demonstrated that differences in antibody titer, which reflect infection history, are significantly heritable. Here we attempt to identify the genetic factors influencing variation in these serological phenotypes. Blood samples from >1300 Mexican Americans were quantified for IgG antibody level against 12 common infections, selected on the basis of their reported role in cardiovascular disease risk: Chlamydia pneumoniae; Helicobacter pylori; Toxoplasma gondii; cytomegalovirus; herpes simplex I virus; herpes simplex II virus; human herpesvirus 6 (HHV6); human herpesvirus 8 (HHV8); varicella zoster virus; hepatitis A virus (HAV); influenza A virus; and influenza B virus. Pathogen-specific quantitative antibody levels were analyzed, as were three measures of pathogen burden. Genome-wide linkage and joint linkage and association analyses were performed using ~1 million SNPs. Significant linkage (lod scores >3.0) was obtained for HHV6 (on chromosome 7), HHV8 (on chromosome 6), and HAV (on chromosome 13). SNP rs4812712 on chromosome 20 was significantly associated with C. pneumoniae (P=5.3 × 10⁻⁸). However, no genome-wide significant loci were obtained for the other investigated antibodies. We conclude that it is possible to localize host genetic factors influencing some of these antibody traits, but that further larger-scale investigations will be required to elucidate the genetic mechanisms contributing to variation in antibody levels.     

Lactoferrin: a promoter of polymorphonuclear leukocyte adhesiveness

Polymorphonuclear leukocytes (PMN) degranulate, adhere to vascular endothelium, or aggregate to each other following exposure of the cells to high concentrations of chemotactic stimuli such as formyl-methionyl- leucyl phenylalanine (FMLP). PMN released the specific granule product lactoferrin more readily in response to chemotactic stimuli, which correlated with promotion of PMN aggregation as measured by light transmission and enhanced PMN adherence. Both concanavalin A (Con-A) and phorbol myristate acetate (PMA), agents that lead to specific granule discharge, induced and sustained human PMN aggregation. Similarly, supernatants, generated from Con-A-treated PMN, aggregated fresh PMN in the presence of alpha-methylmannoside, a competitive inhibitor of the lectin. Anti-human lactoferrin IgG but not normal goat IgG blunted the aggregation elicited by both PMA and FMLP. Both human milk lactoferrin and rabbit PMN lactoferrin aggregated human lactoferrin promoted PMN adherence to endothelial cells. The enhanced PMN stickiness was correlated with the early phase of degranulation. Thus, PMN lactoferrin serves an autoregulatory role to retain PMN at inflammatory sites to amplify the inflammatory response.