Risky behavior in teens with cystic fibrosis or sickle cell disease: a multicenter study

OBJECTIVE: To determine the prevalence and age of onset of common risky behaviors such as smoking and sexual activity in teens with cystic fibrosis and those with sickle cell disease and to compare their behaviors with those of adolescents in the general population. DESIGN: Survey. SETTING: All five major pediatric tertiary care centers in North Carolina (study participants with sickle cell disease or cystic fibrosis) and North Carolina public schools (comparison population). PARTICIPANTS: Three hundred twenty-one adolescents with cystic fibrosis or sickle cell disease aged 12 to 19 years (mean age, 15.6 years; 49% female). Demographically matched comparison teens for each group were selected from 2760 in-school adolescents (mean age, 16.0 years; 51% female). MAIN OUTCOMES MEASURES: Prevalence of tobacco and marijuana use, alcohol use, sexual intercourse, sexually transmitted diseases, seat belt use, weapon carrying, and age of onset of these behaviors. RESULTS: Chronically ill teens reported significantly less lifetime and current use of tobacco, marijuana, and alcohol; less sexual intercourse; less weapon carrying, less drunk driving, and more seat belt use than their peers. Nonetheless, 21% of the teens with cystic fibrosis and 30% of those with sickle cell disease had smoked; sexual intercourse was reported by 28% and 51%, respectively. Age of onset of these behaviors was frequently older for the chronically ill teens. CONCLUSION: Teens with cystic fibrosis or sickle cell disease took more potentially damaging health risks than might be expected, although the prevalence was lower than reported by their peers. Future longitudinal studies should examine the relationships between chronic illness, physical and psychosocial maturation, and risky behavior. Screening for psychosocial issues, including risky behaviors, should be incorporated into the routine health care of chronically ill teens.     

一氧化氮与亚硝基硫醇相互转化机制的研究

目的：探讨一氧化氮（ＮＯ）与亚胡基硫醇间的相互转化机制。方法：应用光谱扫描、毛细管电泳和化学发光等分析技术对ＮＯ和亚砂基硫醇（Ｒ－ＳＮＯ）间的相互关系进行系统研究。结果：ＮＯ在含氧实验体系极不稳定,迅速被氧化为来硝酸盐,并进而在微酸性条下与还原性巯基结合为Ｒ－ＳＮＯ。Ｒ－ＳＮＯ可自发而缓慢的持续释放ＮＯ,且此释放速率由于自由基的存在而加速。结论：进一步从理化性质上为内皮细胞衍生舒血管因子是亚硝基复     

内镜下扩大经鼻蝶入路至斜坡区的解剖学研究

目的探索内镜下经扩大鼻蝶入路显露斜坡区的可行性,为切除斜坡区病变提供解剖学参考。方法在10例成人头部固定标本上,内镜下模拟扩大经鼻蝶手术入路显露斜坡区,观察有关显微解剖标志。结果扩大经鼻蝶内镜入路可磨除从鞍后到斜坡、枕骨大孔前缘的骨性结构;可显露斜坡区腹侧硬膜下的椎基底动脉及其分支、后交通动脉及其与大脑后动脉汇合处、动眼神经、脑干腹侧等结构。此入路的手术标志主要包括:蝶筛隐窝、蝶窦开口、视神经隆突、颈内动脉隆突与颈内动脉视神经隐窝、咽结节、枕骨大孔前缘。结论内镜下扩大经鼻蝶手术入路可充分显露鞍后-斜坡区的腹侧硬膜下结构,适用于此区病变的手术治疗。     

阿仑膦酸钠的一般药理研究

ig阿仑膦酸钠2.5,5和10mg/kg对小鼠的协调运动和自主活动,麻醉猫的呼吸频率、呼吸深度、平均动脉压、心率及心电图无明显影响;iv 5mg/kg对麻醉猫的呼吸、血压、心率及心电图亦无明显影响。iv 10mg/kg对麻醉猫的血压有短暂降低作用,对呼吸、心率及心电图无显著改变。     

地塞米松与ATP联用在体外诱导细粒棘球绦虫原头节细胞凋亡的研究

目的 探讨地塞米松与三磷酸腺苷（ATP）联用在体外诱导细粒棘球绦虫原头节细胞凋亡的作用。 方法 体外培养细粒棘球绦虫原头节,分别设地塞米松（5 mmol/L）组、 ATP（1.6 mmol/L）组、 地塞米松（5 mmol/L）+ATP（1.6 mmol/L）组和空白对照组,显微镜下观察原头节变化。药物诱导8 h后,选取原头节形态改变最明显的一组和空白对照组,透射电镜观察这两组原头节的超微结构,原位末端脱氧核糖核苷酸转移酶标记技术（TUNEL法）检测原头节中的凋亡细胞,半胱氨酸天冬氨酸蛋白酶-3（caspase-3）活性检测试剂盒检测该酶活性,琼脂糖凝胶电泳检测两组原头节的DNA片段。 结果 药物诱导8 h后观察,与对照组相比,地塞米松组和地塞米松+ATP组的原头节均出现团缩、顶突内凹和体积缩小,钙颗粒明显减少且模糊不清,未见原头节活动,其中地塞米松+ATP组原头节的形态改变更明显,故选择该组作为实验组,与空白对照组进行后续试验。透射电镜观察见实验组原头节中实质细胞体积缩小、细胞膜皱缩、细胞基质浓缩、核异染色质凝集呈团块状或新月形边集于核膜下,表现出凋亡细胞的特征。TUNEL法在实验组的原头节中检测到散在的凋亡细胞,对照组则未见凋亡细胞。实验组caspase-3活性约为对照组的12倍。电泳结果显示,实验组DNA中有约150 bp的核小体DNA片段。 结论 地塞米松与ATP联用可在体外诱导细粒棘球绦虫原头节细胞凋亡。     

吗啡增强谷氨酸单钠神经毒性及其作用机制

用皮层神经细胞体外培养、形态学观察、单个神经细胞内游离钙检测及乳酸脱氢酶(LDH)测定等方法,观察了吗啡对谷氨酸单钠(MSG)神经毒性增强作用以及纳洛酮对吗啡作用的逆转,分析了其可能的作用机制。结果表明:吗啡能显著增强的MSG的细胞毒作用.纳络酮可逆转这种增强作用,细胞内Ca²⁺超载可能是兴奋性神经毒素引起神经元死亡的共同病理学机制。     

A general method for concentrating blood samples in preparation for counting very low numbers of white cells

BACKGROUND: To count extremely low levels of white cells (WBCs) in WBC- reduced blood components, a larger volume of sample must be processed. The goal was to develop an all-purpose method for concentrating the samples obtained from WBC-reduced red cells or platelets. The method was designed to be compatible with a variety of counting techniques. STUDY DESIGN AND METHODS: Coded samples of red cell concentrates with an expected WBC concentration of 200, 100, 50, and 10 per mL and of the diluent (undetectable WBCs/mL) were sent to three sites on five occasions and counted by the use of the concentration method, crystal violet stain, and a Nageotte counting chamber. Additional samples were tested by flow cytometry, polymerase chain reaction, and volumetric capillary cytometry. RESULTS: The results from the three test sites showed good linearity, with an overall r2 = 0.9994. The lower limit of accurate detection of the assay was 10 WBCs per mL. The results were biased toward underestimation, particularly at one of the test sites (Site A). There were no significantly different results in Sites B and C. The intra-assay CV was acceptable. Precision (reproducibility) at the three test sites varied. CONCLUSION: This method allows reliable determination of WBC concentrations as low as 0.01 per microL in blood. Despite the use of technologists trained in Nageotte chamber counting, validation testing demonstrated that one test site's performance was significantly different from that of the other two sites, because of both underestimation bias and variation in count results. The sample concentration method, when used in conjunction with an automated assay for WBC identification, should permit larger volume analysis with a greater degree of precision and a lower limit of detection than is found in assays that do not concentrate the sample before counting.     

过度训练机制的研究进展

目的:了解训练适应的生理机制及过度训练与运动能力的定量关系,明确过度训练和疲劳的生理病理界限。资料来源:应用计算机检索万方数据库和中国知网1984/2006有关过度训练机制方面的文章,以"过度训练","机制","机理"等为检索词,限定文章语种为English或中文。资料选择:对资料进行初审,选取包括过度训练的分类、临床表现、诊断及过度训练产生的病理机制密切相关的文献。排除标准:重复性和内容单一文章。资料提炼:共收集50篇关于过度训练机制方面的研究文献。排除文献内容单一的文章20篇,剩余30篇纳入分析。资料综合:①过度训练的临床表现可分为两型,即交感型和副交感型。其症状、机制、运动项目及好发年龄都有所不同,但都表现为运动能力下降。交感型多发于爆发力及非耐力性项目,而副交感型则多发于耐力运动员。②过度训练的诊断主要建立在病史和典型的身体及心理症状上,并辅以生化指标、心电图、脑电图检查等。③内分泌系统兴奋和抑制之间的不平衡是造成过度训练的主要机制。目前在过度训练时免疫机能变化还不能用来解释和预测过度训练,因为这些变化与基础水平相比差别很小,临床意义不大。同步研究过度训练时的病理形态与机能变化对揭示其发病机制有着重要的意义。结论:对于训练适应的机制及训练与运动能力的定量关系的研究已取得了很大进展,但对训练产生适应和由于过度训练引起机能损害之间的界限仍很模糊。