菌斑pH转化试验与菌斑中变形链球菌感染水平的相关性研究

目的　探讨菌斑 pH转化试验 (Cariostat)与菌斑中变形链球菌感染水平之间的相关性。 方法　对 6 0名儿童 (乳牙列组儿童 35名 ,混合牙列组儿童 2 5名 )分别取左、右上后牙颊面牙菌斑 ,用右侧上后牙菌斑做Cariostat试验给出龋活性得分。同时将左侧上后牙颊面菌斑涂于TYCSB培养基 ,厌氧培养 48小时后计数菌落数。采用Spearman相关分析进行统计。 结果　乳牙列组儿童和混合牙列组儿童菌斑pH转化试验与菌斑中变形链球菌感染水平相关系数分别为r =0 .412 (P <0 .0 5 )和r =0 .6 5 1(P <0 .0 1)。结论　菌斑pH转化试验与菌斑中变形链球菌感染水平呈正相关。     

Immune cell subsets in necrotizing fasciitis: an immunohistochemical analysis

Current concepts of the pathophysiology of necrotizing fasciitis (NF), a life-threatening infection of soft tissues associated with a toxic shock syndrome, emphasizes the role of bacterial superantigens as mediators of cytokine release by immune lymphocytes. In order to assess the cellular basis of immune activation, immunohistochemistry was applied to the analysis of inflammatory cell subsets in situ in 13 patients with NF. The percentage of inflammatory cells in skin and soft tissue was scored from 0 to 3+ (>50%). Substantial numbers of CD15+ polymorphonuclear leukocytes were present in 12 of 13 patients. CD3+ T-lymphocytes accounted for >10%, CD68+ macrophages for >50%, and Factor XIIIa+ mononuclear cells for >10% of the mononuclear cell infiltrates, respectively, in 10 of 13 patients, whereas CD1a+ cells were present in only 3 of 13 cases and accounted for <10% of mononuclear inflammatory cells. We conclude that immune lymphocytes and accessory immune cells are represented in substantial numbers in the early lesions of NF, and their presence supports current concepts with respect to the pathophysiology of this disorder.     

广州市儿童A族链球菌T型连续7年调查

目的　调查广州市学龄儿童咽部携带A族链球菌 (GAS)T型在不同时期的流行规律和特点。方法　从1988年 9月至 1994年 7月 ,分别在广州市越秀区 (城市 ) ,广州市番禺区大石镇 (农村 )采用随机整群抽样的方法在小学3～ 5年级的小学生中抽取 2～ 3个班学生作为研究对象 ,研究时间分别为 1988年 9月至 1989年 8月、1990年 5月至1991年 4月、1992年 9月至 1993年 7月、1993年 8月至1994年 7月共 4个学年度 ,跨度达 7年的长期观察和研究 ;研究期内每个月对每个受试者进行一次咽拭子培养 ,将分离出的 β 溶血性链球菌进行杆菌肽试验 ,兰菲分组 ,T分型和OF分型。结果　共分离出 2 5 30株GAS ,T型分布结果依序为T不可分型 (UT)占 17 6 8%、T6 11 2 3%、T4 9 2 9%、T17 79%、T115 6 1%、T8/ 2 5 /IMP195 4 2 %和T5 / 2 7/ 4 44 98%等 7个占总菌株 5 %以上的主导菌型 ;城乡两地菌型差异较大 (P <0 0 0 1) ;城乡两地T型在不同年份变化较大(P <0 0 0 1) ;4 2 4株GAS作OF试验 ,结果OF阴性菌株占6 5 8%。结论　广州市 1988年 9月至 1994年 7月之间 ,学龄儿童咽部流行的GAST型主导菌株依序为T6、4、1、11、8/2 5 /IMPl9和 5 / 2 5 / 4 4为主 ,城乡两地流行的主导菌型差异较大 ,不同年份GAST型分布也存在很大差异     

Potential biomarkers of human salivary function: a modified proteomic approach

Objective

In previous studies, we defined groups of subjects with opposite salivary function. Group membership was associated with clinically relevant outcomes. High aggregation-adherence (HAA) groups showed lower levels of caries, supragingival plaque, total streptococci, and Tannerella forsythensis than low high aggregation-adherence (LAA) groups. In this study, we used a proteomic approach to search for biomarkers which could be useful as risk indicators for those outcomes.

Design

Clarified resting whole saliva from each of 41 HAA and LAA subjects was separated by preparative isoelectric focusing. Fractions showing the most distinctive protein profiles were pooled into four sets (pI 3-3.5, pI 4-4.7, pI 5.7-7.7, pI 10-11.5). Each pool then was compared by SDS-PAGE. Image analysis software was used to quantify matched bands. Partial least squares analysis (PLS) was used to determine which of the 65 bands from all four pools were the best predictors of group membership, caries, total plaque, total streptococci, and T. forsythensis counts. Those bands were identified by mass spectroscopy (MS-MS).

Results

Two bands consistently were strong predictors in separate PLS analyses of each outcome variable. In follow-up univariate analyses, those bands showed the strongest significant differences between the HAA and LAA groups. They also showed significant inverse correlations with caries and all the microbiological variables. MSMS identified those bands as statherin, and a truncated cystatin S missing the first eight N-terminal amino acids.

Conclusions

Levels of statherin and truncated cystatin S may be potential risk indicators for the development of caries and other oral diseases.     

Concentration of phenoxymethylpenicillin in tonsillar tissue

Summary Seventeen patients underwent tonsillectomy 55–120 min after recieving oral phenoxymenthylpenicillin 12.5 mg/kg bodyweight. The penicillin concentration in serum and tonsillar tissue in each patient was determined by a microbial assay. In 9 patients with tonsillar hyperplasia, but with no prior history of tonsillitis, the mean penicillin concentration in serum and in tonsillar tissue was 5.0 mg·1^–1 and 1.32 mg·g^–1, respectively, and in 8 patients with manifest tonsillitis the corresponding values were 3.01 mg·1^–1 and 0.67 mg·g^–1. It appears that the penicillin concentration in tonsillar tissue is about 1/5 to 1/4 of that in serum, regardless of whether the tonsils are inflamed or hypertrophied.     

Efficacy and mechanisms of non-antibacterial, chemical plaque control by dentifrices--an in vitro study

OBJECTIVES: The provision of antiplaque benefits to dentifrices assists patients in improving hygiene and reducing susceptibility to gingivitis and caries. Chemical plaque control involves different mechanisms and is mostly associated with antibacterial effects, but also includes effects on pellicle surface chemistry to improve cleansing or discourage renewed plaque formation. It is the aim of this paper to analyze in vitro detachment of co-aggregating oral actinomyces and streptococci from pellicle surfaces by dentifrice supernates and to study subsequent de novo streptococcal deposition. METHODS: Detachment by dentifrices of a co-adhering bacterial pair was studied in the parallel plate flow chamber on a 16 h pellicle coated surface. After detachment by perfusing the chamber with a dentifrice, re-deposition was initiated by flowing with a fresh streptococcal suspension. The dentifrices included both a regular, SLS-fluoride based formulation as well a pyrophosphate, anticalculus and antimicrobial formulations. RESULTS: All dentifrice supernates containing SLS were effective in detaching co-adhering bacteria from pellicles surfaces, except in combination with SnF(2). When hexametaphosphate was added immediate detachment was relatively low, but continued even during re-deposition. The re-deposition of streptococci after detachment by other, NaF containing dentifrices involved relatively few large aggregates, presumably because fluoride was able to block bi-dentate calcium binding sites on the bacterial cell surfaces, mediating co-adhesion. When pyrophosphate was present in addition to NaF, re-deposition involved significantly more large aggregates, likely because pyrophosphate served as a bi-dentate bridge between calcium bound on the bacterial cell surfaces. CONCLUSION: Commercially available dentifrice formulations differ in their ability to stimulate bacterial detachment from pellicles and dependent on their composition yield the formation of large co-adhering aggregates of actinomyces and streptococci in de novo deposition.     

微生物凝集素的研究进展

凝集素（lectin）是一类可使细胞凝集的蛋白质或糖蛋白,包括微生物凝集素、植物凝集素和动物凝集素,在多个学科领域有重要的应用价值。本文就微生物凝集素的种类、主要性能和功能以及口腔内微生物凝集素的研究作一综述。     

氟硅橡胶义齿软衬材料对口腔微生物的影响

目的研究国产热固化氟硅橡胶义齿软衬材料对口腔微生物的影响。方法对13例戴软衬垫全口义齿的病人进行口腔念珠菌和链球菌数量变化的定量研究。9例戴普通树脂全口义齿病人作为对照组。结果病人戴软衬垫义齿后,口腔中念珠菌数量与对照组相比显著增加(p<0.05),链球菌数量变化不明显。念珠菌含量过高的病人出现软衬材料的表面老化和局部剥脱。结论本实验选用的国产热固化氟硅橡胶义齿软衬材料在口内重衬后,显著增加口腔念珠菌数量。     

Remarkable Attachment of Lactoferrin to Streptococcus pyogenes during Acute Pharyngotonsillitis

The purpose of this study was to establish whether lactoferrin (hLf) attached to Streptococcus pyogenes, one causative agent of acute pharyngotonsillitis (AT), during the course of the disease. Bacterial samples were obtained from the tonsillar surfaces of 7 patients (6 females, 1 male; median age 26 years; range 16-50 years) suffering from AT who were culture-positive for S. pyogenes and from 5 healthy adult controls who were culture-negative for this pathogen. Using gold-labelled antiserum against S. pyogenes and hLf, this pathogen and other bacteria on the tonsillar surfaces coated with hLf could be identified by tracing the gold particles in a transmission electron microscope. In healthy adults, 8% (median value; range 6-12%) of the surface tonsillar bacteria were coated with hLf. In AT patients, 59% (median value; range 42-67%) of S. pyogenes were coated with hLf, in contrast to 9% (median value; range 0-26%) of all other bacteria (p &lt; 0.01). This study hints that hLf might participate in recovery from AT in several ways, e.g. by binding to the S. pyogenes pathogens, in addition to its well-known virtue of iron-binding capacity.     

Application of patient population-derived pharmacokinetic–pharmacodynamic relationships to tigecycline breakpoint determination for staphylococci and streptococci

Correctly determined susceptibility breakpoints are important to both the individual patient and to society at large. A previously derived patient population pharmacokinetic model and Monte Carlo simulation (9999 patients) were used to create a likelihood distribution of tigecycline exposure, as measured by the area under the concentration–time curve at 24 h (AUC₂₄). Each resultant AUC₂₄ value was paired with a clinically relevant fixed MIC value ranging from 0.12 to 2 mg/L. For each AUC₂₄–MIC pair, the probability of microbiologic response was calculated using an exposure–response relationship, which was derived from patients with complicated skin and skin structure infections that involved Staphylococcus aureus or streptococci or both. The median probability of microbiologic success was 94% or greater for MIC values up to and including 0.25 mg/L. The median probability of microbiologic success was 66% or less for MIC values of 0.5 mg/L or greater. These data support a susceptibility breakpoint of 0.25 mg/L for S. aureus and streptococci.