Exploring the oral bacterial flora: current status and future directions

Oral Diseases (2010) 16 , 136–145 Objective: The oral cavity forms an indispensable part of the human microbiome, for its unique and diverse microflora distributed within various niches. While majority of these organisms exhibit commensalism, shifts in bacterial community dynamics cause pathological changes within oral cavity and distant sites. The aim of this review was to appraise the current and emerging methods of detecting bacteria of the oral cavity paying particular attention to the cultivation independent methods. Design: Literature pertaining to cultivation based and cultivation independent methods of oral bacterial identification was reviewed. Methods: The specific advantages and disadvantages of cultivation based, microscopic, immunological and metagenomic identification methods were appraised. Results: Because of their fastidious and exacting growth requirements, cultivation based studies grossly underestimate the extent of bacterial diversity in these polymicrobial infections. Culture independent methods deemed more sensitive in identifying difficult to culture and novel bacterial species. Conclusion: Apart from characterizing potentially novel bacterial species, the nucleic acid sequence data analyzed using various bioinformatics protocols have revealed that there are in excess of 700 bacterial species inhabiting the mouth. Moreover, the latest pyrosequencing based methods have further broadened the extent of bacterial diversity in oral niches.     

A review of studies of parent-child communication about sexuality and HIV/AIDS in sub-Saharan Africa

Parent-child sexuality communication has been identified as a protective factor for adolescent sexual and reproductive health, including HIV infection. The available literature on this topic in sub-Saharan Africa is increasing; however a systematic review of studies has not been conducted. This article reviews the literature in the area of parental or caregiver and child communication about sexuality and HIV/AIDS in sub-Saharan Africa. A review of peer reviewed literature published between 1980 and April 2011 was conducted. Communication process studies investigating the frequency, content, style, tone of discussions, preferences, as well as associations with and barriers to sexuality communication are reviewed. In addition, studies which examine behavioral associations with parent-child sexuality communication, and intervention studies to improve parent-child sexuality communication are examined. The findings from process studies suggest wide variation in terms of frequency of discussions, with a range of socio-demographic and other factors associated with sexuality communication. Overall, findings demonstrate that discussions tend to be authoritarian and uni-directional, characterized by vague warnings rather than direct, open discussion. Moreover, parents and young people report a number of barriers to open dialogue, including lack of knowledge and skills, as well as cultural norms and taboos. Findings are less clear when it comes to associations between parental communication and adolescent sexual activity and contraception use. However, nascent indications from intervention research suggest positive findings with increases in frequency and comfort of discussions, among other outcomes. Gaps in the research are identified and discussed with implications for future studies.     

Kinetics of peripheral blood mononuclear cell mobilization with chemotherapy and/or granulocyte-colony-stimulating factor: implications for yield of hematopoietic progenitor cell collections

BACKGROUND: Peripheral blood progenitor cells (PBPCs) are commonly collected and used to reconstitute hematopoiesis after high-dose chemotherapy. However, strategies for optimal collection and assessment of leukapheresis components are not standardized. STUDY DESIGN and METHODS: Hematopoietic progenitor cell assays were performed on 369 leukapheresis components collected from 95 patients who had received doxorubicin-based chemotherapy and/or granulocyte-colony-stimulating factor (G-CSF). Precollection patient hematologic values, leukapheresis collection values, component hematopoietic progenitor cell assays, and patient outcome measures were summarized. The kinetics of mononuclear cell (MNC) and PBPC mobilization were assessed among four patient groups. RESULTS: Patient group was a significant predictor of the peripheral blood MNC count on the day of collection (p<0.0001), and that value was a significant predictor of granulocyte-macrophage– colony-forming unit (CFU-GM) yield (p<0.0001). This relationship between the peripheral blood MNC count on the day of collection and CFU- GM yield differed according to patient group (p<0.0001). CFU-GM made up a larger fraction of peripheral blood MNCs collected from patients who received chemotherapy plus G-CSF than collected from those who received G-CSF alone. Moreover, the peripheral blood MNC count and the corresponding CFU-GM yield increased significantly on consecutive days of collection in patient groups receiving chemotherapy and G-CSF but were unchanged or decreased in patients receiving G-CSF alone. CONCLUSION: The relationship between peripheral blood MNC count and leukapheresis component CFU-GM yield differed significantly between patients who received chemotherapy and G-CSF and those who received G- CSF alone for the mobilization of PBPCs. Patient peripheral blood MNC count and component CFU-GM yield are useful for both assessing and suggesting revisions to PBPC mobilization and collection strategies.     

Heavy and light cigarette smokers have similar dysfunction of endothelial vasoregulatory activity: an in vivo and in vitro correlation

OBJECTIVES: The goal of this study was to investigate the dose-dependent effects of active cigarette smoking on endothelial nitric oxide (NO) and endothelin-1 (ET-1) biosynthesis. BACKGROUND: Limited studies have suggested that active cigarette smoking may be associated with a dose-dependent reduction of endothelium-dependent vasodilation (EDV). The underlying biochemical changes that cause this dose-specific effect, such as changes in the endothelial NO biosynthetic pathway and ET-1 production, have not been examined. METHODS: Flow- and nitroglycerin-mediated reactivity of the brachial artery were measured in eight nonsmokers, seven light smokers (< or =1 pack/week) and eight heavy smokers (> or =1 pack/day), and their sera were added to confluent ( approximately 85%) monolayers of human umbilical endothelial cells (HUVECs) for 12 h. Basal and substance P-stimulated NO and basal ET-1 production were measured. The HUVECs used for measuring basal NO production were lysed, and both endothelial NO synthase (eNOS) protein expression and eNOS activity were determined. RESULTS: Serum cotinine level and pack-years of smoking were significantly lower in light smokers compared with heavy smokers (p < 0.006 and p < 0.004, respectively). There were no significant differences between heavy smokers and light smokers in EDV (p = 0.52), basal- (p = 0.70) and stimulated-NO production (p = 0.95), eNOS protein (p = 0.40) and eNOS activity (p = 0.63). Compared with nonsmokers, all the parameters were significantly altered in both of the smokers' groups. No differences were found in nitroglycerin-mediated vasodilation and in vitro ET-1 production among the three groups. CONCLUSIONS: These results indicate light smoking may have similar detrimental effects on EDV and NO biosynthetic pathway as does heavy smoking. These data may have important implications concerning the amount of active cigarette exposure that imparts cardiovascular risk.     

织构复合水凝胶体系的假说

生物软组织可视为具有多层次结构的织构复合水凝胶体系(TCHS)、以水凝胶复合元件(HCE)为基本的构件(CP),通过一定的组合、排列方式构筑一系列多层次结构的不同软组织。软组织中任何层次的结构单元既可视为织构复合水凝胶体系又可视为构件。任何层次的TCHS中,构件的结构及其组合排列方式决定着该层次单元的功能。以织构复合水凝胶体系的观点考察了真核细胞、角膜和骨骼肌的多层次结构。双层网络水凝胶、皮芯复合水凝胶纤维人工肌肉模型、时空匹配可降解细胞支架等研究成果初步地证明了提出织构复合水凝胶体系观点的合理性。     

健胃愈疡颗粒干预下大鼠胃溃疡黏膜乳癌相关肽和血小板活化因子的表达及与胃黏膜疏水性的相关性研究

目的:观察对胃溃疡复发有较好疗效的健胃愈疡颗粒对溃疡黏膜乳腺癌相关肽和血小板活化因子表达的影响,分析其可能的作用机制。方法:实验于2005-07/2006-07在湘雅医院中心实验室完成。SD大鼠110只,雌雄各半,随机抽签法分为5组,即正常对照组、假手术组、雷尼替丁组、健胃愈疡组,各20只;模型组30只。以Okabe改良法复制大鼠实验性胃溃疡,假手术组仅以生理盐水代替乙酸注入玻管内。造模后24h,雷尼替丁组、健胃愈疡组大鼠分别灌服盐酸雷尼替丁和健胃愈疡颗粒(药物组成为:柴胡、党参、白芍、延胡索、白芨、珍珠层粉、青黛、甘草,湖南湘雅制药有限公司生产)药液10mL/kg,分别相当于2.70,1.62g/kg,1次/d。假手术组、模型组灌服蒸馏水10mL/kg。10d后各组中随机取出10只大鼠剖腹取胃(处死前大鼠禁食24h),90d时将模型组20只大鼠再分为模型复发组和模型非复发组,各10只;除正常对照组、假手术组、模型非复发组大鼠腹腔内注射生理盐水外,其余各组大鼠腹腔内注射白细胞介素1,1μg/kg;在注射48h,大鼠禁食24h后,剖腹取胃。观察其对胃溃疡大鼠胃黏膜氨基己糖及磷脂含量、溃疡指数和胃黏膜血流的影响,并用RT-PCR观察乳癌相关肽乳癌相关肽和血小板活化因子表达的变化。结果:实验动物110只,全部进入结果分析。①模型组10,92d胃黏膜血流均低于正常对照组(P<0.01);健胃愈疡组同期胃黏膜血流均高于模型组(P<0.01)。②健胃愈疡组和雷尼替丁组10d溃疡指数均低于模型组(P<0.01,P<0.05);模型复发组、健胃愈疡组和雷尼替丁组92d溃疡指数均高于模型组(P<0.01);健胃愈疡组10,92d溃疡指数及复发率均低于雷尼替丁组(P<0.05,P<0.01)。③模型组10,92d氨基己糖和磷脂含量均低于正常对照组(P<0.01)。健胃愈疡组10,92d氨基己糖和磷脂含量均高于模型组和雷尼替丁组(P<0.01)。溃疡指数与氨基已糖、磷脂含量呈负相关(r=-0.957,-0.960,P<0.01)。④健胃愈疡组和雷尼替丁组10d乳癌相关肽mRNA表达较正常组和假手术组提高,血小板活化因子mRNA的表达下调(P<0.01),健胃愈疡组两指标表达变化较雷尼替丁组显著(P<0.01);模型复发组、健胃愈疡组和雷尼替丁组92d乳癌相关肽mRNA、血小板活化因子mRNA的表达同组10d比较差异无显著性意义(P>0.05);模型组乳癌相关肽mRNA、血小板活化因子mRNA的表达同组10d比较差异有显著性意义(P<0.01)。结论:健胃愈疡颗粒可提高乳癌相关肽mRNA及下调血小板活化因子mRNA的表达,影响胃黏膜氨基己糖及磷脂含量,可能是其促进溃疡愈合的机制之一。     

定量组织速度成像技术评价阿霉素诱导兔心肌病模型：与常规经胸超声心动图比较

目的:采用定量组织速度成像技术评价阿霉素诱导兔心肌病模型,并与常规经胸超声心动图比较其评估优势。方法:实验于2005-06/2006-08在大连医科大学完成。①实验分组及处理:取纯种新西兰白兔22只,雌雄不限,随机分成阿霉素组12只,给予阿霉素每次2mg/kg,以1g/L耳缘静脉注射,每周1次,注射8周;对照组10只每周注射2mL/kg生理盐水,共8周。②实验评估:每周应用HPSonos5500型彩色多普勒超声诊断仪(美国Agilent公司生产)对两组兔心脏进行左室收缩末期和舒张末期内径明、室间隔厚度、E峰、射血分数、左室短轴缩短率等常规超声参数测量,使用GEVivid7型彩色多普勒超声诊断仪(美国GE公司生产)进行收缩期和舒张期峰值速度、收缩期加速度定量组织速度成像参数测定。结果:22只兔进入统计。①对照组1～12周各参数与阿霉素组基础状态下比较无明显差异(P>0.05)。②第4周阿霉素组二尖瓣环运动的平均收缩期和舒张期峰值速度、收缩期加速度较基础状态明显减低(P均<0.05)。③第7周阿霉素组二尖瓣环运动的收缩期和舒张期峰值速度、收缩期加速度较基础状态明显减低(P<0.01),E峰较基础状态明显减低(P<0.05)。④第8周阿霉素组二尖瓣环运动的收缩期和舒张期峰值速度、收缩期加速度较基础状态明显减低(P<0.01),E峰较基础状态明显减低(P<0.01),左室收缩末期和舒张末期内径明显增大(P<0.05)。⑤第12周阿霉素组二尖瓣环运动的收缩期和舒张期峰值速度、收缩期加速度较基础状态明显减低(P<0.01),左室收缩末期和舒张末期内径明显增大(P<0.01),室间隔厚度、左室后壁厚度明显变薄(P<0.05),射血分数、左室短轴缩短率和E峰明显减低(P<0.01)。结论:定量组织速度成像参数可有效评价阿霉素诱导心肌病模型兔心肌的病理变化,较常规超声参数更敏感。     

成纤维细胞生长因子Ⅱ型受体功能获得型点突变影响小鼠颅底软骨发育

目的:对比野生型小鼠和成纤维细胞生长因子Ⅱ型受体(fibroblast growth factor receptor2,fgfr2)基因S252W突变型小鼠颅底软骨的生长发育情况,探讨fgfr2功能持续增强对小鼠颅底软骨发育的影响。方法:实验于2004-03/2005-04在解放军第三军医大学大坪医院野战外科研究所创伤中心实验室,创伤、烧伤与复合伤国家重点实验室完成。①fgfr2 小鼠和C57BL/6J小鼠交配后取F1代,利用聚合酶链反应方法进行fgfr2突变型小鼠基因型的鉴定,得到野生型和fgfr2受体功能获得型点突变型两组小鼠。②标本取材及处理:分别在两组实验动物中,取胚胎期16d(E16)、胚胎期17d(E17)、新生2d(P2)、新生8d(P8)的小鼠的颅底作为标本。一部分体积分数为0.75的乙醇溶液固定。另一部分标本行40g/L多聚甲醛固定,150g/L乙二胺四乙酸溶液脱钙,常规石蜡包埋、切片。③阿尔辛-茜素红骨架染色显示颅底整体骨骼的发育情况。软骨组织染为蓝色,骨组织染为红色。④脱钙骨切片后进行苏木精-伊红染色。未脱钙骨切片后进行Calcein染色,荧光显微镜下观察钙化组织的情况。⑤使用地高辛RNA标记试剂盒按照产品说明制备Col 10(Collagen 10)地高辛标记的互补RNA探针,对颅底软骨联结进行检测软骨分化标志基因表达情况的原位杂交。⑥组织切片染色结果使用SPOT Advanced软件进行数码拍摄。结果:①实验小鼠颅底发育的大体情况:fgfr2受体功能获得型点突变小鼠从胚胎后期开始就表现出短颅现象。②阿尔辛蓝-茜素红骨架染色、Calcein染色和苏木精-伊红染色显示,fgfr2受体功能获得型点突变小鼠出生后颅底软骨联结没有出现提前融合的现象,但是颅底软骨生长发育差,软骨细胞增生区、肥大区缩短。突变小鼠的颅底软骨发育障碍导致颅底骨组织的生长发育也出现障碍。③原位杂交:Col10在野生型和突变型小鼠颅底软骨的表达部位未见明显差异,但是这个软骨细胞分化标志基因的表达强度降低。结论:fgfr2 S252W点突变能够引起小鼠颅底软骨联结处的软骨细胞发育异常,导致颅底骨骼发育畸形。fgfr2可能具有调控软骨细胞系发育的功能,从而可能在骨骼发育、骨折修复等方面发挥重要作用。     

血管内皮生长因子与白细胞介素12在急性白血病不同时期血清中的变化

目的:由于造血干/祖细胞发生基因突变,子代细胞增殖失控等导致的恶性血液病。血管内皮生长因子和白细胞介素12参与这一发生发展过程,检测不同时期其在急性白血病患者静脉血中的水平,有利于认知与血管新生及体液免疫的相关性。方法:随机选择2005-06/2006-04在吉林市中心医院住院的急性白血病患者25例,均经FAB分型或免疫学分型确诊,患者知情同意,并经医院伦理委员会批准。将患者分为:①初诊未治组10例。②复发组5例。③完全缓解组10例。并设9名健康查体者为正常对照。应用定量酶联免疫吸附实验测定受试者血清中血管内皮生长因子和白细胞介素12的水平,在评定白细胞介素12水平时,将初诊未治组与复发组合并为初诊复发组:①两组的发病机制相似。②两组病例数较少,单独观察没有统计学意义。结果:25例患者和9名健康对照者均进入结果分析。①初诊未治组血管内皮生长因子含量高于完全缓解组及正常对照组(P均<0.05)。②正常对照组白细胞介素12水平与初诊复发组、完全缓解组之间差异均具有显著性意义(P均<0.05)。③正常对照组血管内皮生长因子含量与白细胞介素12之间存在负相关(r=-0.9644P<0.05)。④初诊复发组、完全缓解组血管内皮生长因子和白细胞介素12含量之间均无相关性(r=-0.0883,-0.3593,P均>0.05)。结论:急性白血病患者血清中血管内皮生长因子和白细胞介素12含量与临床病情变化有关,可以作为诊断和预测急性白血病发生和复发的指标。