False results associated with darkground microscopy of subgingival plaque

This study considers false results which may arise due to problems in the preparation or examination of specimens for darkground microscopy of subgingival plaque. Subgingival plaque samples obtained with a sterile curette were placed in 0.1-0.3 ml sterile full or 1/4 strength Ringer's solution: 0.85% saline, 1% gelatin in 0.85% saline, formal saline or pyrogen-free water for injection. Test slides were prepared from the original dispersion, and control slides from the corresponding sterile solution. Optimal dispersion solution, syringe dispersion frequency and the effect on motility of delay in processing samples were tested. Slides were also prepared from dispersions of 11 representative subgingival "periodontopathic" organisms. Problems in sampling included variability in counts between sites with comparable pocket depths, contamination of the sample and reduction of the sample volume after scaling. Problems in dispersion included contamination, uneven distribution of the different morphotypes and destruction of delicate organisms. Problems in slide preparation included slide contamination, limitation in the number of samples that can be assessed by one examiner at a given time without loss of activity of motile cells, and preparation of a cell monolayer. Problems in identification and counting included confusion of Brownian movements with motility, coccoid particles with cocci, spirochetes with campylobacter, flagella with flagella-like structures, size of cocci, counting of fragmented spirochetes and non-motile flagellated organisms and motile cells, and also bias in counting. Problems in morphotype grouping included the observation that many (10 of the 11 representative) periodontitis-related organisms were in the non-motile groups and not all cells of the motile species (Campylobacter, Capnocytophaga) showed motility. The results indicate that each stage of subgingival plaque darkground microscopy, sampling, dispersion, slide preparation, counting, morphotype grouping and interpretation may lead to false results if not representative or reproducible. Procedures are suggested for the minimisation of problems in the preparation and examination of subgingival plaque specimens for darkground microscopy.     

社区呼吸康复治疗在慢性呼吸系统 疾病患者干预管理中的应用*

摘 要： 目的：探究中老年人颈动脉斑块与血清25羟维生素D （25-OH-D） 的相关性。 方法：选取2019年1月—2020 年 12 月自愿参与该研究的上海市浦东新区北蔡社区常住居民 412 人为研究对象,测定及记录其一般临床资料及血清 25-OH-D 等实验室检测结果。依据血管 B 超结果将研究对象分为有斑块组 268 人和无斑块组 144 人,比较两组人群血清 25-OH-D水平差异,用Pearson相关性分析各变量的关系,采用logistic回归分析颈动脉斑块形成的危险因素。结果：有斑块 组血清 25-OH-D 为 （45.18±18.71） nmol/L,无斑块组为 （56.12±19.54） nmol/L,两组差异有统计学意义 （χ2=5.573,P＜ 0.05）。相关性分析显示颈动脉斑块与收缩压、HbA1c、年龄呈正相关 （r值分别为0.388、0.119和0.128,P值均＜0.05）;与 血清 25-OH-D 呈负相关 （r=-0.365,P＜0.01）。血清 25-OH-D 是颈动脉斑块形成的独立相关因素 （OR=0.973,95%CI： 0.960,0.985,P＜0.05）。结论：低水平血清25-OH-D是颈动脉斑块形成的独立危险因素。     

西安市2型糖尿病患者颈动脉狭窄发生情况及其影响因素分析

目的 调查2型糖尿病（T2DM）患者颈动脉狭窄（CAS）的发生率,并探讨影响其发生CAS的相关影响因素。方法 以2018年1月至2020年12月于西安市某医院内分泌门诊首次就诊的T2DM患者为研究对象进行资料收集、体格检查、血生化指标检测及颈动脉超声检查,对T2DM患者CAS检出情况进行描述性分析,并对CAS检出影响因素进行单、多因素分析。结果 2 679例T2DM患者中检出CAS 328例,检出率12.24%。多因素Logistic回归分析表明,年龄越大（OR=1.039）、糖尿病病程越长（OR=1.115）、血糖控制不达标（OR=1.387）、血脂异常（OR=1.970）和高血压（OR=3.725）是T2DM患者合并CAS的危险因素。结论 T2DM患者合并CAS情况突出,应重视对糖尿病病程较长和血糖控制不佳的T2DM患者进行颈动脉超声监测,针对T2DM患者合并CAS的危险因素,应尽早进行控制及预防,避免心脑血管不良事件的发生。     

脑梗塞患者颈动脉粥样硬化斑块的超声研究

目的探讨脑梗塞患者颈动脉粥样硬化病变程度和特征,评价彩色多普勒超声对该粥样斑块的诊断价值.方法应用HP5500超声仪,对35例脑梗塞患者和46例正常人进行颈动脉检查.结果脑梗塞组颈动脉粥样硬化斑块检出率、斑块记分均显著高于对照组[分别为85.7%和21.7%,P＜0.01;(6.745±3.214)mm和(3.408±3.613)mm,P＜0.001],且脑梗塞组软斑比例为55.8%,显著大于对照组33.3%(P＜0.01),脑梗塞组斑块表面不规则即Ⅱ、Ⅲ度的比例亦显著大于对照组(41.9%/11.1%,11.6%/0%,P＜0.05).结论脑梗塞的发生与颈动脉粥样硬化病变密切相关;软斑块是发生脑梗塞的主要危险;超声检查对颈动脉粥样硬化具有诊断价值,可为脑梗塞的预防与治疗提供参考资料.     

颈动脉粥样斑块与冠状动脉病变

目的 研究颈动脉粥样斑与冠状动脉病变的关系。方法 将82例冠心病待排和冠心病患者按冠状动脉造影结果分成正常组和冠脉粥样病变组,同期超声检测颈动脉粥样硬化程度。结果 颈动脉粥样斑块与冠脉弱粥样硬化之间有较密切的关系。颈动脉粥样斑块对狭窄性冠状动脉病变预测的敏感性为71.7%,特异性为91.9%,阳性和阴性预测值分别为91.7%和73.9%,其准确性为81.7%。结论 颈动脉超声检测可作为预测冠状动脉粥样硬化有价值的指标。     

登革病毒甲基纤维素微量蚀斑技术的建立

目的建立登革病毒甲基纤维素微量蚀斑技术。方法将4株登革病毒接种于C6/36细胞内,5-7d后染色,观察蚀斑情况并计数。将测得值与组织培养半数感染量测定结果比较。结果登革病毒甲基纤维素微量蚀斑技术重复性好,比组织培养半数感染量法敏感。结论甲基纤维素徽量蚀斑技术可靠易行,可用于登革病毒滴定。     

新型数字显示式颈总动脉压迫器

本文介绍了新近研制的数显便携式颈总劝脉压迫器的工作原理、电路设计和调试结果，该仪器增强了患侧动脉切术前施行压迫锻炼改善脑侧支循环的效果并为临床实时监测提供客观数据指标。     

Beta-adrenergic drugs do not affect phrenic nerve afterdischarge

Summary In anesthetized cats, a carotid sinus nerve was stimulated electrically. After this stimulation the time course of the afterdischarge in the phrenic nerve activity was studied in the control situation, during infusion of isoprenalin and after administration of metoprolol. The time courses were identical in all situations.It is concluded that in spite of the fact that the beta-adrenergic drugs change the steady state phrenic nerve activity, the afterdischarge is unchanged and therefore probably mediated by a separate mechanism. A comparison is made with analogous findings in patients with a hyperventilation syndrome.     

Immunohistological study of senile brains by using a monoclonal antibody recognizing β amyloid precursor protein: significance of granular deposits in relation with senile plaques

Summary Immunochemical analyses revealed that a monclonal antibody Am-3 recognized amyloid precursor protein (APP) in senile plaques extracted from Alzheimer's brain, but did not recognize amyloid protein. Immunohistochemically, however, the staining pattern of Am-3 in frozen section of Alzheimer's brain was almost the same with that of rabbit polyclonal antibody to amyloid peptide which could recognize both amyloid protein and APP. In other words, APP was present in senile plaques of various types, cerebrovascular amyloid and granular deposits. The granular deposits were 5–10 m in size and laminarily distributed in the 1st, 3rd and 4th layers of cerebral cortex. They were especially abundant in 1st and 4th layers where senile plaques were usually fewer in number. Although the distribution in the cerebral cortex was different between the senile plaques and the granular deposits, the number of the granular deposits was well correlated with that of senile plaques. The granular deposits were negative in Congo-red birefringence, but contained amyloid protein as well as APP fragment judging from positive staining by both Am-3 and polyclonal antibody to synthetic amyloid peptide. Thus, they could be regarded as pre-amyloid.