“纳米”细菌

“纳米”细菌是近年发现的新菌种,因体积小,具有矿化能力而备受医学界的关注。本文介绍了“纳米”细菌的微生物学,流行病学特点及鉴定方法,同时阐述了其与一些疾病的关系。     

纳米细菌与生物矿化关系研究现状

纳米细菌（Nanobacteria NB）是芬兰科学家KAJANDER等在培养哺乳动物细胞时发现在无污染的情况下,仍有部分细胞生长繁殖不佳,发生空泡样变性、溶解或凋亡。针对此种现象他们对已知所有微生物进行了检测,结果都为阴性。于是对这些细胞进行透射电镜观察,结果在细胞内发现了一种很小的原核微生物,在上世纪90年代由KAJANDER命名这种生物为Nanobacteria并申请了专利。     

纳米细菌及其诱发肾结石形成的研究进展

纳米细菌是近年来新发现的一种直径为纳米级且具有矿化能力的细菌。在肾结石形成过程中,纳米细菌可以作为结晶的活性中心,黏附、侵入并破坏肾集合管的上皮细胞和肾乳头细胞,形成磷灰石晶核,从而诱发肾结石形成。综述了肾结石中的纳米细菌及其诱发肾结石形成的体外模拟和动物学模型,讨论了纳米细菌与肾结石形成的关系。     

先天性佝偻病与纳米细菌关系研究的现状与展望

先天性佝偻病是胎儿出生后就发生的特殊阶段的佝偻病,病因并不十分清楚,迁延不愈会影响小儿骨骼发育和免疫功能。纳米细菌导致的胎盘钙化与小儿佝偻病有关,推测纳米细菌与先天性佝偻病有关。因此诊断和防治纳米细菌感染可能对于先天性佝偻病的预防有一定临床意义。     

纳米细菌研究的现状和展望

纳米细菌是1988年芬兰科学家CIFTCIOGLU等[1]进行哺乳动物细胞培养时,在胎牛血清中发现一种原核微生物。后来KAJANDER将其命名为Nanobacteria,译名为纳米细菌(NB),并申请专利。纳米细菌广泛存在于自然界的矿物质中和生物体内,正常人血清中存在纳米细菌。并且它能感染人类、牛、鹿和其它哺乳动物,是一种人畜共患的致病原[2]。     

“纳米细菌”与疾病的研究进展

20世纪80年代后期,芬兰科学家Kajander等在进行哺乳动物细胞培养时,用透射电子显微镜扫描检查时发现细胞内存在一种超微结构.1990年他正式将这种原核微生物命名为"纳米细菌"(nanobacteria,NB),并申请了专利,后来将其称为"钙化性纳米颗粒"(calcifying nanoparticles,CNP).     

钙化胎盘中纳米细菌的分离培养与鉴定

目的分离、培养与鉴定钙化胎盘中的纳米细菌,为进一步探讨纳米细菌致胎盘钙化的机制奠定基础。方法剖腹产手术收集25份钙化胎盘组织标本,通过脱矿、过滤、离心处理,用细胞培养的方法进行纳米细菌培养,观察其生长情况。运用透射电镜、扫描电镜观察培养物形态。结果 (1)培养3~4周后,对钙化组织培养标本进行观察,发现部分培养管底部出现紧贴管壁生长的白色沉淀物。(2)扫描电镜见纳米细菌为大颗粒成簇分布。(3)透射电镜可见纳米细菌为针状物的聚集体,大小不一。结论首次从钙化胎盘组织中分离培养鉴定出纳米细菌,表明其感染与胎盘钙化有关,需进一步研究其矿化机制以及所致钙化对后代的影响。     

纳米细菌的分离培养和保存方法探讨

目的 以钙化的胎盘组织为例,寻求在钙化组织中分离纳米细菌的最佳方法,以便更多疑似与纳米细菌感染有关的疾病得以准确分离出纳米细菌菌株,并探讨培养和保存纳米细菌的最适宜的条件.方法 (Ⅰ)胎盘钙化组织标本分别用盐酸脱矿与超声振荡脱矿的方法分离纳米细菌,计算其分离阳性率.(2)分离出的纳米细菌分别用细胞培养箱与细菌培养箱培养1个月,利用分光光度计记录两种条件下纳米细菌浓度的变化,并描绘生长曲线.(3)分别用4、- 20与- 80℃冰箱保存钙化组织和纳米细菌,记录纳米细菌分离和复苏的生长状况并绘制生长曲线.结果 (1)钙化组织用盐酸脱矿更易分离得到纳米细菌.(2)细胞与细菌培养环境下纳米细菌的生长速度并无明显差别.(3)4℃保存钙化组织和纳米细菌对于其分离和复苏都要优于- 20℃和- 80℃.结论 对钙化组织进行盐酸脱矿可以更好的分离出纳米细菌,并且可以在细菌培养箱内培养纳米细菌,新鲜钙化组织标本和纳米细菌可以短时间保存在4℃.     

纳米细菌及其诱发肾结石形成的研究进展*

纳米细菌是近年来新发现的一种直径为纳米级且具有矿化能力的细菌。在肾结石形成过程中,纳米细菌可以作为结晶的活性中心,黏附、侵入并破坏肾集合管的上皮细胞和肾乳头细胞,形成磷灰石晶核,从而诱发肾结石形成。综述了肾结石中的纳米细菌及其诱发肾结石形成的体外模拟和动物学模型,讨论了纳米细菌与肾结石形成的关系。     

东钱湖水体异养细菌的时空分布及其与环境影响因素和有机质的关系

为探究宁波东钱湖表层水体中异养细菌丰度的时空分布特征及其环境影响因素对可溶性有机质转化的影响, 实验采用主成分分析及多元逐步回归分析方法研究了三者之间的关系, 结果表明: 调查期间东钱湖表层水体中异养细菌丰度的季节分布特征为夏季>春季>冬季, 支流汇入口、码头或水上乐园区域水体中异养细菌丰度较高, 近岸人类活动带来的陆源污染是造成此分布特征的主要原因; 多元统计分析结果表明ST、DO、COD、Chla、DOM是制约宁波东钱湖表层水体中异养细菌分布的主要环境因素, 且ST、Chla、COD、DOM中的类芳香族蛋白质Ⅰ及类溶解性微生物代谢产物IV与异养细菌丰度呈显著正相关(p<0.05), DO与异养细菌丰度呈极显著负相关(p<0.01); 异养细菌等微生物的代谢转化活动和陆源输入共同决定DOM的来源和转化, 但异养细菌对DOM具体的驱动转化机制有待于进一步的研究。     

Severe hepatopathy in geese and broilers associated with ochratoxin in their feed

The feeding of a shipment of imported corn was associated with a severe reduction in growth and increased mortality in geese, and increased mortality in broilers. Pathological examinations revealed hepatopathy, visceral gout and mild nephropathy in geese, and in broilers an hepatopathy, which was often severe, and ascites. Samples of feed from affected geese farms were examined for up to 24 mycotoxins, and ochratoxin was found in 6 of 15 samples at levels up to 930 ng/g. The syndrome was experimentally reproduced by feeding geese and broilers suspect feeds with the natural ochratoxin contamination. It is believed that another, unidentified, mycotoxin was the major cause of the hepatotoxicity, and that ochratoxin served in this case as an indicator of a multi-mycotoxin involvement. This revised version was published online in June 2006 with corrections to the Cover Date.     

糖尿病患者肠道菌群特征及其相关性的系统评价

目的对糖尿病患者肠道菌群特征及其相关性进行系统评价。方法检索知网、维普、万方、PubMed、Cochrane library、Embase等数据库关于糖尿病患者肠道菌群特征及其相关性的文献,同时追踪纳入文献的参考文献,时限为2009年3月至2019年3月,采用统一提取表,由两名研究者独立按照规定的纳入排除标准进行文献提取和方法学质量评估。最后采用RevMan 5.3软件进行Meta合并,Stata 12.0软件进行亚组分析与发表性偏倚识别。结果共纳入25篇研究,合计2 209例患者。Meta分析显示:(1)糖尿病患者菌群总量(SMD=-0.30,P=0.53)、乳杆菌数量(SMD=-0.79,P=0.20)下降,拟杆菌数量(SMD=1.43,P=0.12)、梭菌数量(SMD=0.28,P=0.40)增加,差异均无统计学意义,双歧杆菌数量(SMD=-1.82,P=0.02)下降,差异有统计学意义。(2)糖尿病患者菌群Shannon指数I~2=91%,r=-0.21[-0.32,0.09],P0.05;Chao1指数I~2=0%,r=-28.17[-40.85,-15.48],P0.05;均下降。(3)拟杆菌、双歧杆菌、梭菌与空腹血糖的相关性分别为:I~2=0%,r=-0.15[-0.27,-0.03];I~2=0%,r=-1.16[-1.42,0.91];I~2=0%,r=-0.28[-0.42,-0.14],均P0.05。而乳杆菌的相关性差异无统计学意义:I~2=47%,r=-0.00[-0.30,0.29],P=0.98。(4)乳杆菌和拟杆菌与炎症因子(TNF-α、IL-6)呈负相关,乳杆菌(r=-0.43;r=-0.60),P0.05;拟杆菌(r=-0.58;r=-0.58),P0.05,差异有统计学意义。结论糖尿病患者肠道菌群总量无明显变化,但有益菌含量和多样性下降,拟杆菌、双歧杆菌和梭菌含量与血糖水平呈负相关,而乳杆菌无相关,其结果还需要大样本、高质量的研究加以论证。     

The pattern of organization of intermediate filaments and their asymmetrical association with dense bodies in smooth muscle of an ascidian Halocynthia roretzi

Summary An extensive network of intermediate filaments that interconnected cytoplasmic dense bodies and connected the dense bodies to the cell surface was revealed in double-fixed, tannic acid-stained preparations of ascidian smooth muscle. The filament network ran through spaces in the continuous network of myofibrils, connecting them longitudinally, obliquely and transversely to form an intimately associated, dual network. In their transverse passage, the intermediate filaments ran across myofibrils along I-zones exclusively, interconnecting successive dense bodies.The pattern of attachment of intermediate filaments to dense bodies was predominantly one-sided. The filaments, which themselves were not incorporated into the contractile apparatus, remained folded or unfolded between myofibrils and between sarcomere-like structures in synchrony with the contraction-relaxation cycles.These results suggest that the intermediate filaments mechanically maintain the organization and arrangement of myofibrils via an intimate association with the myofibrils in the regions of the dense bodies, in such a way that the filaments do not impede muscle function.Based on these observations, a new model for the network of intermediate filaments in smooth muscle cells is proposed.     

老年呼吸机相关性肺炎患者肠道菌群特征及其与疾病的相关性

探讨老年呼吸机相关性肺炎(VAP)患者肠道菌群特征及其与疾病的相关性, 为该类患者的治疗提供参考。

选择2018年1月至2020年1月在该院进行机械通气的患者141例, 根据是否发生VAP分为VAP组(n=67)和非VAP组(n=74), 同时选择同期在我院进行体检的健康者为对照组(n=50)。采用16S rRNA荧光定量PCR法检测3组研究对象肠道双歧杆菌和大肠埃希菌数量, 并计算B/E值。采用流式细胞仪检测T淋巴细胞亚群CD3⁺、CD3⁺CD4⁺、CD3⁺CD8⁺、CD4⁺/CD25⁺、CD8⁺/CD28^-以及CD8⁺/CD28⁺细胞水平。采用改良酶学分光光度法检测血浆D-乳酸水平。采用Pearson相关检验分析VAP组B/E值与免疫功能及血浆D-乳酸的相关性。

VAP组患者肠道双歧杆菌数量、B/E值显著低于非VAP组和对照组, 大肠埃希菌数量显著高于非VAP组和对照组(均P < 0.05);非VAP组和对照组比较差异亦均有统计学意义(均P < 0.05)。VAP组患者CD3⁺、CD3⁺CD4⁺、CD3⁺CD8⁺以及CD8⁺CD28⁺细胞水平显著高于非VAP组和对照组, CD8⁺CD28^-细胞水平显著低于非VAP组和对照组(均P < 0.05);非VAP组和对照组比较差异亦均有统计学意义(均P < 0.05)。VAP组患者血浆D-乳酸水平显著高于非VAP组和对照组, 非VAP组和对照组比较差异亦有统计学意义(均P < 0.05)。Pearson相关检验显示, VAP组患者B/E值与CD3⁺、CD3⁺CD4⁺、CD3⁺CD8⁺、CD8⁺/CD28⁺细胞以及血浆D-乳酸水平呈显著负相关, 与CD8⁺/CD28^-细胞呈显著正相关(均P < 0.05)。

VAP患者存在肠道菌群失衡, 且VAP与肠道菌群失衡存在相关性, 促进肠道菌群平衡有助于VAP的防治。

     

不同海拔汉族健康人大循环及微循环特征的对比

目的: 观察青海不同海拔高度的果洛(4 100 m)和互助(2 600 m)与平原地区上海(4 m)汉族健康人大循环及微循环特征。方法: 将青海果洛28名年龄(45.62±10.15)岁、青海互助27名年龄(47.25±8.43)岁、上海20名年龄(43.12±8.28)岁的三地区汉族健康人分为:果洛组(GL)、互助组(HZ)和上海组(SH);抽取静脉血分别行血常规:红细胞(RBC)、血红蛋白(HGB)、红细胞压积(HCT)、血小板(PLT)的检测;凝血功能:凝血酶原时间(PT)、国际标准化比值(INR)、纤维蛋白原(Fib)、部分凝血活酶(APTT)、凝血酶时间(TT)的检测,应用连续无创血流动力学监测仪(CNAP)连续测定连续心排量(CO)、每搏输出量(SV)、平均动脉压(MAP)、心率(HR)、脉压差变异率(PPV)、血管外周阻力指数(SVRI),应用脉氧监测仪测得指脉氧(SPO₂),用旁流暗视野成像(SDF)监测技术观察舌下微循环指标:总血管密度(TVD)、灌注血管密度(PVD)、灌注血管比例(PPV)、微血管流动指数(MFI)。结果: 与上海组比较,互助组和果洛组的RBC、HGB明显升高(P＜0.05),而PLT明显降低(P＜0.05);互助组的PT、Fib、APTT、TT、CO、HR、SV、MAP、SPO₂均明显降低(P＜0.05),而TVD、PVD、PPV、MFI均明显升高(P＜0.05);果洛组的HCT、 Fib、CO、SV、PPV、MAP、TVD、PVD均明显升高(P＜0.05),而PT、INR、TT、SPO₂均明显降低(P＜ 0.05)。与互助组比较,果洛在组的RBC、HGB、HCT、 Fib、APTT均明显升高(P＜0.05);而SPO₂、TVD、PVD、INR、TT均明显降低(P＜0.05)。结论: 不同海拔地区的健康人微循环具有较明显的差异,高海拔地区健康人群微循环密度较平原地区明显增加,特别是在中度海拔地区更为明显,其特殊的生理意义,对救治高原地区感染性休克及慢性高原病有指导意义。     

Methods of nonlinear dynamics in estimation of electroencephalograms of healthy people and of patients with epilepsy

A possibility is discussed of use of methods of nonlinear dynamics for analysis of spontaneous EEG and of the EEG caused by low acoustic stimuli in healthy people and in patients with epilepsy. The use of methods of nonlinear dynamics—the fractal dimension of EEG—in clinical and scientific practice is described.     

Methods of non-linear dynamics in estimation of electroencephalograms of healthy people and of patients with epilepsy

A possibility is discussed of use of methods of non-linear dynamics for analysis of spontaneous EEG and if the EEG caused by low acoustic stimuli in healthy people and in patients with epilepsy. A use of methods of non-linear dynamics--the fractal dimension of EEG--in clinical practice and in research is described.     

Inverse correlation between serum free IGF-I and IGFBP-3 levels and blood pressure in patients affected with type 1 diabetes

BACKGROUND: Even though the gene encoding for IGF-I is considered of most importance amongst blood pressure-regulating genes in mouse models, little and discordant data are available in literature for what concerns a possible relationship between blood pressure and serum free IGF-I values in humans. In addition, no information is available on type 1 diabetes patients. AIM: Our aim is to analyze the relationship between systolic and diastolic blood pressure and serum free IGF-I and IGFBP-3 levels in subjects suffering from type 1 diabetes. RESULTS: A highly significant inverse correlation was observed between serum free IGF-I levels and both systolic and diastolic blood pressure in subjects affected with type 1 diabetes. Similar but less significant relationships were observed for IGFBP-3, whose levels were also significantly and directly correlated with those of free IGF-I. The correlation between systolic and diastolic blood pressures with free IGF-I and between systolic blood pressure and IGFBP-3 levels were confirmed after adjusting for age, gender, age at diagnosis, disease duration, familial history, HBA1c, and amount of insulin administered by multivariate logistic regression analysis. A decrease in free IGF-I and IGFBP-3 levels, along with increases in blood pressure, significantly influenced the presence of diabetic complications, confirming how these molecules may be considered as severity markers for patients with type 1 diabetes as well as risk factors for altered pressure control linked diseases.