家兔失神经支配腓肠肌肌纤维退行性变与修复性再生的超微结构观察

目的:观察家兔腓肠肌失神经支配后肌纤维在退行性变与修复性再生过程中超微结构的变化,探讨失神经支配骨骼肌修复性再生障碍的机制。方法:实验于2005-04/2006-04在南方医科大学中心实验室完成。选择成年新西兰大白兔20只,切断一侧胫神经腓肠肌肌支,术后1,4,8,12,16周分别采用耳缘静脉注射空气处死4只。取实验侧和对照侧腓肠肌内侧头肌组织少许,用于制备超薄切片标本,透射电镜观察各时间点兔失神经腓肠肌肌纤维形态。结果:纳入动物20只,均进入结果分析。①正常家兔腓肠肌肌原纤维排列整齐,肌小节和Z线清晰,线粒体均匀分布在肌原纤维之间,排列规则,细胞核位于质膜周边,未见溶酶体。②失神经支配1周,肌原纤维排列基本整齐,线粒体增多,无明显肿胀。③失神经支配4周,线粒体明显增多肿胀,部分线粒体空泡样变,溶酶体增多,Z线模糊,肌原纤维间隙增大。④失神经支配8周,肌纤维明显萎缩退行性变,大部分肌原纤维消失,残留的肌原纤维变得模糊,间隙增大,肌小结丧失正常的结构,胞浆内含有大量空泡变性的细胞器,可发现畸形核,染色质浓缩、边集,肌细胞膜极度皱缩。镜下发现较多的位于基膜下活化的肌卫星细胞,细胞内含有发达的粗面内质网和丰富的胞浆。一些肌卫星细胞直接与肌纤维融合。同时在间质中可发现一些形态上很象成纤维细胞的细胞,不过这些细胞含有大量的粗面内质网,胞浆内有颗粒和微丝,少量的圆形的线粒体。在退行性变的肌纤维基膜下也可发现肌管样结构的再生肌细胞,在这些肌管内一些肌丝在一起聚集成束,没有组装成肌原纤维,没有正常的肌小结结构。在它们周围有细小的空肌管样结构,可能是以往再生的肌细胞退行性变后的残余体。在间质中可发现一些细小的肌纤维。⑤失神经支配12周,大部分肌纤维萎缩退行性变,但是仍可发现没有萎缩的肌纤维,这些肌纤维细胞核位于周边,有良好的收缩系统,纤维排列规则,Z线清晰,有完整的肌膜。⑥失神经支配16周,肌卫星细胞的数量明显减少,并可发现大量细小的肌纤维,多分布在较大的肌纤维附近,肌膜完整平滑,无皱褶。可发现核位于中央的肌纤维,胞浆内肌原纤维结构清楚,但是肌原纤维的排列远不如核位于周边的肌纤维整齐,说明其收缩系统发育不良。结论:失神经支配后肌细胞退行性变和修复性再生同时存在,再生的肌细胞不能,化发育为成熟的肌纤维,进而发生退行性变。长时间失神经支配,肌卫星细胞的耗竭是失神经支配骨骼肌晚期的主要超微结构变化。     

颈椎椎后肌肉组织中肌膜Na^＋-K^＋-ATP酶活性与颈椎病

目的:探讨颈椎椎后肌肉组织Na -K -ATP酶活性变化与颈椎病的关系。资料来源:应用计算机检索PubMed1988-01/2004-12相关骨骼肌损伤与肌组织Na -K -ATP酶关系的文献,检索词“Na -K pump,Na -K -ATPase,muscle”,限定文献语言种类为English。同时计算机检索CNKI1990-01/2005-12相关Na -K -ATP酶与骨骼肌损伤的关系及颈椎病发病病因的文献,检索词“Na -K -ATP酶,骨骼肌,颈椎病病因”,限定文献语言种类为中文。资料选择:对资料进行初审,选取包括Na -K -ATP酶与肌组织损伤关系的文献,开始查找全文。纳入标准:Na -K -ATP酶活性变化与骨骼肌损伤密切相关的文献研究。排除标准:重复研究,Meta分析类文章。资料提炼:共检索到939篇关于Na -K -ATP酶与骨骼肌损伤相关方面的文献,最终纳入20篇符合标准的文献。资料综合:众多研究表明,Na 、K 与骨骼肌的兴奋、收缩、疲劳有密切关系,而Na -K -ATP酶又是调节细胞内外Na 、K 浓度必不可少的高分子蛋白,也就是说,骨骼肌一系列活动均离不开Na -K -ATP酶,Na -K -ATP酶活性变化与骨骼肌损伤是相互影响的。而强迫屈颈体位作为颈椎病发病的危险因素之一,可使颈椎椎后肌肉Na -K -ATP酶活性降低,酶活性降低致使肌细胞损伤,并最终导致骨骼肌损伤而发病。结论:以颈椎椎后肌肉酶活性的变化来阐释中医药对颈椎病确切疗效的相关研究未见,这有待于进一步研究,以充分展示中医药在颈椎病等相关疾病中的治疗优势。     

骨关节炎大鼠关节软骨修复与橄榄叶提取物的干预效应

目的:观察橄榄叶提取物对白陶土及鹿角菜胶诱导的大鼠骨关节炎组织炎症的预防作用及对关节软骨的修复作用。方法:试验于2005-11/12在大连医科大学中日合作医药科学研究所进行。实验动物:选择健康雄性SD大鼠80只。实验材料:受试物橄榄叶提取物[由日本国Eisai食品与化学有限公司(日本国东京市)提供]。实验分组及给药:按体质量将大鼠随机分为5组,每组16只。模型对照组,灌胃给予蒸馏水,消炎痛组,灌胃给予消炎痛2mg/kg体质量,其余3组为橄榄叶提取物组,分别给予橄榄叶提取物(活性成分为以羟基酪醇为主的多酚)25,50,100mg/kg体质量灌胃,连续5d。第1天给药后1h,采用白陶土与鹿角菜胶诱发大鼠单发亚急性关节炎。实验评估:①诱发关节炎后1,3,5d,用容积测量法测定每组8只大鼠的左右后肢足跖体积,计算肿胀度,并同时用游标卡尺测定其胫跗骨关节最大径。②诱发关节炎后第5天,测定大鼠足跖伊文思蓝含量。每组的另8只大鼠,在诱发关节炎第5天麻醉后处死,剪下右足跖做组织病理学检查,观察橄榄叶提取物对大鼠骨关节炎中组织炎症的预防作用及对关节软骨的修复作用。结果:80只大鼠全部进入结果分析。①足跖肿胀度及胫跗骨关节径:诱发关节炎后1,3,5d,橄榄叶提取物50mg/kg组和100mg/kg组大鼠的右后足跖肿胀度均明显小于模型对照组大鼠[1d:(46.7±4.2)%,(44.8±6.8)%,(52.5±4.0)%;3d:(40.4±4.8)%,(37.4±5.7)%,(45.0±2.9)%;5d:(34.5±4.8),(31.7±5.3)%,(40.4±4.0)%,P<0.05],橄榄叶提取物25mg/kg体质量组,50mg/kg体质量组,100mg/kg体质量组大鼠的右后胫跗骨关节径与模型对照组大鼠比较差异无显著性(P>0.05)。②足跖伊文思蓝含量:诱发关节炎后第5天,橄榄叶提取物50mg/kg,100mg/kg组大鼠的右后足跖伊文思蓝含量均明显小于模型对照组大鼠(P<0.05)。③组织病理学检查及评分:组织病理学检查可见,与模型对照组比较,橄榄叶提取物50mg/kg组,100mg/kg组大鼠骨关节炎中组织炎症浸润明显减少,软骨组织无破坏,且组织病理学评分也明显小于模型对照组(P<0.05)。结论:橄榄叶提取物在50mg/kg体质量及以上剂量能有效地预防白陶土与鹿角菜胶诱发的大鼠骨关节炎中组织炎症,且对软骨有修复作用。     

Monocyte antigen CD14 is a phospholipid anchored membrane protein

A cDNA clone encoding the human monocyte antigen CD14 was isolated by transient expression in COS cells of a cDNA library prepared from phorbol diester-treated HL60 cells. RNA blot analysis showed abundant expression of a single mRNA species in mature monocytes and an increased expression of the mRNA following induction of differentiation in leukemic cell lines. The DNA blot hybridization pattern was consistent with a single-copy gene. The predicted amino acid sequence lacks the characteristic transmembrane domain and stop transfer motif of conventionally anchored membrane proteins. COS cells transfected with the CD14 cDNA released virtually all CD14 protein in soluble form following treatment with glycosyl phosphatidylinositol-specific phospholipase C, and CD14 immunoreactivity was absent from the affected monocytes of a patient with paroxysmal nocturnal hemoglobinuria (PNH). The data show that, to the limit of experimental sensitivity, all monocyte CD14 is joined to the plasma membrane by a phosphatidylinositol phospholipid.     

CONGENITAL DISLOCATION OF THE KNEE AS A CONSEQUENCE OF PERSISTENT AMNIOTIC FLUID LEAKAGE

SUMMARY A case congenital dislocation of both knees and dislocation of the left hip in an infant whose mother had a chronic amniotic fluid leakage after mid-trimester amniocentesis.     

A qualitative and quantitative study of rete ovarii development in the fetal rat: Correlation with the onset of meiosis and follicle cell appearance

Development of the rete ovarii and its contribution to the cells of the ovary were examined in fetal rats. Histochemical and autoradiographic techniques were used for the observations between days 15 and 21 of gestation. The data presented indicate that the rete system contributes somatic cells to the ovary before birth. The basement membrane which surrounds the cuboidal epithelium of the mesonephric tubules immediately adjacent to the ovary becomes discontinuous on day 15 of gestation. The mesonephric epithelial cells in this region form a knot or clump of pleiomorphic cells, with no apparent tubular organization, and this clump later becomes surrounded by a basement membrane. On day 17 of gestation the newly established fetal rete ovarii is comprised of three regions; (1) the extraovarian mesonephric tubules (ER), (2) intraovarian cords of flattened epithelioid cells which surround the oogonia (IR), and (3) a knot or clump of cells connecting the ER and IR regions (CR). The entire rete system is enclosed by a continuous basement membrane as defined by Periodic Acid-Schiff Reagent techniques. Autoradiographic and quantitative analyses demonstrate that the ER tubule cells proliferate and are incorporated into the other regions of the rete system. These processes begin on day 17 and continue until at least day 21 of gestation. The role these mesonephric tubule cells may play in the regulation of meiosis and their early contribution to the presumptive granulosa cell population is discussed.     

Socio-economic and psychological correlates of suicidality among Hong Kong working-age adults: results from a population-based survey

BACKGROUND: The global toll of suicide is estimated to be one million lives per year, which exceeded the number of deaths by homicide and war combined. A key step to suicide prevention is to prevent less serious suicidal behaviour to preclude more lethal outcomes. Although 61% of the world's suicides take place in Asia and the suicide rates among middle age groups have been increasing since the economic crisis in many Asian countries, population-based studies of suicidal behaviour among working-age adults in non-western communities are scarce. METHOD: Data from a population-based survey with 2015 participants were used to estimate the prevalence of suicidal ideation and behaviour among the working-age population in Hong Kong, and to study the associated socio-economic and psychological correlates. We focused particularly on potential modulating factors between life-event-related factors and suicidal ideation. RESULTS: Six per cent of the Hong Kong population aged 20-59 years considered suicide in the past year, while 1.4% attempted suicide. Hopelessness, reasons for living, and reluctance to seek help from family and friends had direct association with past-year suicidal ideation. Reasons for living were found to moderate the effect of perceived stress on suicidal ideation. CONCLUSIONS: Suicidality is a multi-faceted problem that calls for a multi-sectored, multi-layered approach to prevention. Prevention programmes can work on modulating factors such as reasons for living to reduce suicidal risk in working-age adults.     

Preclinical to Clinical Translation of CNS Transporter Occupancy of TD-9855, a Novel Norepinephrine and Serotonin Reuptake Inhibitor

Background:

Monoamine reuptake inhibitors exhibit unique clinical profiles that reflect distinct engagement of the central nervous system (CNS) transporters.

Methods:

We used a translational strategy, including rodent pharmacokinetic/pharmacodynamic modeling and positron emission tomography (PET) imaging in humans, to establish the transporter profile of TD-9855, a novel norepinephrine and serotonin reuptake inhibitor.

Results:

TD-9855 was a potent inhibitor of norepinephrine (NE) and serotonin 5-HT uptake in vitro with an inhibitory selectivity of 4- to 10-fold for NE at human and rat transporters. TD-9855 engaged norepinephrine transporters (NET) and serotonin transporters (SERT) in rat spinal cord, with a plasma EC₅₀ of 11.7ng/mL and 50.8ng/mL, respectively, consistent with modest selectivity for NET in vivo.Accounting for species differences in protein binding, the projected human NET and SERT plasma EC₅₀ values were 5.5ng/mL and 23.9ng/mL, respectively. A single-dose, open-label PET study (4–20mg TD-9855, oral) was conducted in eight healthy males using the radiotracers [¹¹C]-3-amino-4- [2-[(di(methyl)amino)methyl]phenyl]sulfanylbenzonitrile for SERT and [¹¹C]-(S,S)-methylreboxetine for NET. The long pharmacokinetic half-life (30–40h) of TD-9855 allowed for sequential assessment of SERT and NET occupancy in the same subject. The plasma EC₅₀ for NET was estimated to be 1.21ng/mL, and at doses of greater than 4mg the projected steady-state NET occupancy is high (>75%). After a single oral dose of 20mg, SERT occupancy was 25 (±8)% at a plasma level of 6.35ng/mL.

Conclusions:

These data establish the CNS penetration and transporter profile of TD-9855 and inform the selection of potential doses for future clinical evaluation.     

Individual,Social, and Environmental Factors Associated with Initiating Methamphetamine Injection: Implications for Drug Use and HIV Prevention Strategies

The purpose of this study was to determine the incidence and predictors of initiating methamphetamine injection among a cohort of injection drug users (IDU). We conducted a longitudinal analysis of IDU participating in a prospective study between June 2001 and May 2008 in Vancouver, Canada. IDU who had never reported injecting methamphetamine at the study’s commencement were eligible. We used Cox proportional hazards models to identify the predictors of initiating methamphetamine injection. The outcome was time to first report of methamphetamine injection. Time-updated independent variables of interest included sociodemographic characteristics, drug use patterns, and social, economic and environmental factors. Of 1317 eligible individuals, the median age was 39.9 and 522 (39.6%) were female. At the study’s conclusion, 200 (15.2%) participants had initiated injecting methamphetamine (incidence density: 4.3 per 100 person-years). In multivariate analysis, age (adjusted hazard ratio [aHR]: 0.96 per year older, 95%CI: 0.95–0.98), female sex (aHR: 0.58, 95%CI: 0.41–0.82), sexual abuse (aHR: 1.63, 95%CI: 1.18–2.23), using drugs in Vancouver’s drug scene epicentre (aHR: 2.15 95%CI: 1.49–3.10), homelessness (aHR: 1.43, 95%CI: 1.01–2.04), non-injection crack cocaine use (aHR: 2.06, 95%CI: 1.36–3.14), and non-injection methamphetamine use (aHR: 3.69, 95%CI: 2.03–6.70) were associated with initiating methamphetamine injection. We observed a high incidence of methamphetamine initiation, particularly among young IDU, stimulant users, homeless individuals, and those involved in the city’s open drug scene. These data should be useful for the development of a broad set of interventions aimed at reducing initiation into methamphetamine injection among IDU.