基质金属蛋白酶与根尖周病

基质金属蛋白酶（matrix metalloproteinases，MMPs）属于锌依赖性蛋白水解酶的一种，是由多种蛋白酶组成的多功能内肽酶，主要降解细胞外基质（extracellularmatrix，ECM）。在正常稳定状态组织中MMP表达量极少，而在炎性细胞因子、激素、生长因子刺激下和细胞转化过程其表达上升。病理上根尖周病通常分为根尖周炎和根尖囊肿，根尖周炎多是由根管内微生物感染引起的局部炎症性疾病，常累及邻近牙槽骨和根尖部的牙骨质，使其吸收破坏。     

HIV感染者牙周炎的相关研究

由于对艾滋病患者广泛应用了高活性抗病毒治疗,病人的寿命得以延长,同时也发现(HIV)感染者牙周病的发病及进展情况也发生了新的变化,如非典型性牙周病减少,而更多的是常见牙周病.HIV 患者牙周病的发生发展与细菌、病毒、真菌等多种微生物感染有关,虽然其细菌组成与HIV-患者牙周病的组成相似,但病毒与真菌的检出率较高.     

派丽奥与牙康治疗牙周炎的疗效比较

目的　比较派丽奥(2%盐酸米诺环素软膏)与牙康(甲硝唑棒)治疗牙周炎的临床疗效及对牙周可疑致病菌的清除作用。方法　选取11例慢性牙周炎患者的26颗牙周炎患牙为研究对象。患牙要求:①牙周袋探诊深度≥4 mm,且探诊后出血;②左右对称。26颗患牙随机分成实验组(派丽奥治疗组)13颗,对照组(牙康治疗组)13 颗。观察用药前及用药后7 d和14 d,患牙的牙周临床指标菌斑指数(PLI)、牙龈指数(GI)、探诊深度(PD)、探诊出血(BOP)的变化和龈下附着菌斑中螺旋体、球菌、杆菌的百分比,以及非附着菌斑中牙龈卟啉单胞菌、中间普氏菌、二氧化碳噬纤维菌等牙周可疑致病菌百分比的变化。结果　实验组和对照组患牙在用药前各项牙周临床指标和微生物学指标均无显著性差异(P>0.05)。用药后,两组患牙绝大部分牙周临床指标和微生物学指标均较用药前明显改善(P<0.05),但两组间无显著性差异(P>0.05)。结论　派丽奥与牙康均是治疗牙周炎有效、安全的局部治疗药物,两者的疗效无显著性差异。     

完善充填的经治根管失败原因分析

充填完善的经治根管疗效欠佳的病例并非罕见，但在国内尚未得到足够重视。本文综述了国外的相关研究报道。表明残留病原菌、冠部修复不良及根尖周和牙周病原菌等因素造成根管系统内微生物感染以及非微生物源性的异物反应是根管充填完善但治疗失败者的主要原因。有效控制微生物感染和预防异物反应可以提高根管治疗的成功率。     

菌斑固相、变形链球菌及葡聚糖对酸的缓冲作用

目的研究糖代谢后菌斑固相缓冲力的变化及影响因素。方法采集40名18~21岁的大学生的饥饿牙菌斑,体外10%蔗糖孵育1h。体外制备无糖培养和2%蔗糖培养的变链菌团。以25mmol/L KCl制备菌斑固相、变链菌团和不溶性葡聚糖混悬液及可溶性葡聚糖溶液,用1mmol/LHCl滴定并计数细菌密度,统计学分析。结果变链菌团代谢蔗糖后的缓冲容量为(0·099±0·047)mmol/L,比无蔗糖培养的变链菌团的缓冲容量(0·609±0·202)mmol/L低,且缓冲力随细菌密度降低直线下降,葡聚糖几乎没有缓冲作用[(0·028~0·032)mmol/L]。人牙菌斑固相缓冲力的变化规律与体外纯菌培养研究结果一致。结论菌斑固相缓冲力与所含细菌密度密切相关。     

口腔微生物与口腔鳞状细胞癌关系的研究进展

口腔微生物群落在人类微生物群落和人类健康中发挥着重要作用,微生物与宿主的不平衡可导致口腔疾病和全身疾病。一些肿瘤已经被认为与细菌等微生物的存在相关,口腔肿瘤和微生物的关系也被逐渐认识。本文对口腔鳞状细胞癌与口腔微生物之间的关系进行综述,阐述口腔微生物导致口腔鳞状细胞癌发生的可能途径以及口腔鳞状细胞癌微环境对微生物的影响,为口腔微生物与肿瘤关系的进一步研究提供参考,以实现口腔鳞状细胞癌早期诊断,甚至辅助治疗的目的。     

检验专业学生临床微生物学检验的实践能力培养

《临床微生物学和微生物检验》是一门实践性很强的课程,实验教学占整个教学时数的一半以上,操作技能的好坏直接影响到“实用型”人才的培养。目前实验教学主要存在实验系统性不强、对学生基本技能训练不利、缺乏综合的实验考核等问题。如何系统周密地处理好微生物实验教学的各个环节,为检验专业的学生奠定牢固的理论和实践基础,是当前亟待解决的重要问题。因此,组织好《临床微生物学和微生物检验》的实验教学,对于学生综合素质的提高至关重要。我们做了如下的尝试。     

Preparation of seeding type immobilized microorganisms and their degradation characteristics on Di-n-butyl phthalate

Objective To study the preparation of seeding type immobilized microorganisms and their degradation characteristics on di-n-butyl phthalate （DBP）. Methods Diatomite, clinoptilolite, silk zeolite, and coal fly ash were chosen as reserved materials and modified. Their adsorption capacity and intensity in the bacteria were determined and the best carrier was picked out. The seeding type immobilized microorganisms were prepared by the best carrier and then it degraded DBP under different primary concentration, vibration rate, pH, temperature in the presence of metal compounds. Results The adsorption capacity of the modified coal fly ash, silk zeolite, clinoptilolite and zeolite was 44.2%, 71.6%, 84.0%, and 94.4%, respectively, which was 1.66, 1.49, 1.37, and 1.16 times as high as that of their natural state. Their adsorption intensity was 72.1%, 90.5%, 90.1%, and 91.1% in turn. The modified diatomite was selected to prepare the seeding type immobilized microorganisms. When the primary DBP concentration was 100 to 500 mg/L, the DBP-degraded rate of the immobilized microorganisms could be above 80%. The degradation activity of both the dissociative and immobilized microorganisms was higher in vibration than in stillness. When pH was 6.0 to 9.0, the DBP-degraded rate of the immobilized microorganisms was above 82%, which was higher than the dissociative microorganisms. When the temperature was between 20~C and 40~C, the DBP-degraded rate could reach 84.5% in 24 h. The metal compounds could inhibit the degradation activity of both the dissociative and immobilized microorganisms. The degradation process of the immobilized microorganisms could be described by the first-order model. Conclusion The adsorption capacity of the diatomite, clinoptilolite, silk zeolite and coal fly ash on DBP-degrading bacteria can be improved obviously after they are modified. The modified diatomite is best in terms of its adsorption capacity and intensity. Its seeding type immobilized microorganisms could degrade DBP effectively and is more adaptable to DBP load, temperature, pH than the dissociative microorganisms. The metal compounds could inhibit the activity of both the immobilized and dissociative microorganisms. The degradation reaction of the immobilized microorganisms on DBP is consistent with the gust-order model.     

Influences of copper speciation on toxicity to microorganisms in soils

Objective To investigate the relationship between copper speciation and microbial features （microbial communities and copper tolerance level） in order to determine the adverse effect of different forms of Cu on microorganisms. Methods Tessier＇s sequential extraction procedure was used to qualify the different Cu forms （exchangeable, carbonate bound, Fe/Mn oxide bound, residue and organic matter bound）, and the copper tolerance level （expressed as IC50, influence concentration） was measured by the plate-count method. Results By simple correlation analysis, the ICs0 was positively correlated with the concentration of exchangeable Cu （R2=0.8204）, while weakly correlated with other forms of Cu. Conclusion The bacterial community tolerance increases in the copper-contaminated soil while sensitive bacteria decrease in the copper-contaminated soils. The exchangeable Cu exerts high toxicity to microbial communities.     

158例糖尿病足病原菌分布与创面特点的关系

目的 分析糖尿病足住院患者创面的病原菌分布、药敏情况及其与创面特点之间的关系.方法 选取2017年1月至2019年12月该院急诊外科糖尿病足住院患者158例作为观察对象,取足部创面深部组织,行微生物培养及药敏试验.结果 糖尿病足患者Wagner2、3级创面革兰阳性菌菌株(2级22株,3级30株)多于革兰阴性菌菌株及真菌,Wagner4级创面革兰阴性菌菌株(44株)多于革兰阳性菌菌株及真菌,Wagner 5级共培养细菌2株均为革兰阴性菌.革兰阳性菌对万古霉素、替考拉林、利奈唑胺、替甲环素的敏感度为100％,革兰阴性菌对亚胺培南、美罗培南、庆大霉素、氨基糖苷类的敏感度较高.结论 糖尿病足患者创面病原菌以革兰阳性菌为主,糖尿病足Wagner分级越高,革兰阴性细菌、真菌感染率逐渐升高.