动脉硬化性脑梗死与HLA—I类基因的关联性研究

目的 探讨动脉硬化性脑梗死（ABI）与人类白细胞抗原（HLA）系统的相关性,方法 采用微量淋巴细胞毒分型方法,对我国北方汉族人群39例ABI患者和41例健康对照组的HLA－A,B,C各等位基因共计66个位点进行检测分析。结果 ABI组HLA－A30基因频率较对照组显著增加（RR＝10．36,P＜0．01）,其他HLA－A,B,C基因频率未见与ABI明显相关,结论 HLA－A30基因可能为AB1的易感基因,其可能与ABI致病基因有连锁不平衡或作为免疫应答基因而导致ABI发生,HLA－A30基因可视为ABI高危险性遗传标志。     

Activated caspase-3 expression in Alzheimer’s and aged control brain: correlation with Alzheimer pathology

Several studies have suggested that activated caspase-3 has properties of a cell death executioner protease. In this study, we examined the expression of activated caspase-3 in AD and aged control brains. Activated caspase-3 immunoreactivity was seen in neurons, astrocytes, and blood vessels, was elevated in AD, and exhibited a high degree of colocalization with neurofibrillary tangles and senile plaques. These data suggest that activated caspase-3 may be a factor in functional decline and may have an important role in neuronal cell death and plaque formation in AD brain.     

Non lipid, dose-dependent effects of pravastatin treatment on hemostatic system and inflammatory response

Objectives: The aim of the present study was to evaluate the effects of pravastatin treatment on lipid, inflammation, and coagulation parameters in patients suffering from myocardial infarction with or without carotid atherosclerotic lesions (groups 1 and 2, respectively). Methods: In the first phase of the study, a cross-sectional comparison of lipid, inflammation, and coagulation parameters was performed between the patients and the control group (group 3). Highly significant differences in these parameters were observed, especially in group 1. In the second phase of the study, we assessed the effects of a persistent reduction in cholesterol synthesis induced by increasing doses of pravastatin (20 mg daily for 8 weeks and 40 mg daily for a further 8 weeks). In addition to the well-established lipid-lowering effect, significant changes in inflammation and coagulation parameters were observed. In particular, pravastatin at a dosage of 20 mg/day significantly reduced only fibrinogen levels, while at a dosage of 40 mg/day significantly reduced factor VII, fibrinogen, prothrombin fragments 1 and 2, thrombin–antithrombin complexes, tissue plasminogen activator antigen (tPA:Ag) before venous occlusion (b.o.), inhibitor of plasminogen activator activity (PAI) b.o., PAI activity after occlusion (a.o.), the human autoantibodies against oxidized low-density lipoprotein (LDL), and the c fraction of the third component system levels, and significantly increased tPA:Ag a.o. levels. Results: Our results show that in patients suffering from myocardial infarction the risk of thrombotic complications can be decreased with pravastatin, especially by larger doses. However, the relationship must be further investigated because the observed reductions in the hemostatic system and inflammatory response seemed to be dose dependent, while the effects of pravastatin treatment were not significantly correlated with total and LDL cholesterol changes. Received: 14 June 1999 / Accepted in revised form: 9 March 2000     

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.     

Characterization and cross-reactivity of rabbit antisera to plaque toxins

The effects of heat labile, high molecular weight water-soluble toxins from bacterial plaque on HL60 promyelocytic cells were examined. On gel filtration, four inhibitors of HL60 cell growth and two inhibitors of HeLa cell growth (PT1, PT2) were detected. The first and third HL60 cell inhibitors corresponded to the two HeLa cell inhibitors. The last eluted HL60 cell inhibitor (plaque leukotoxin, PL) did not inhibit HeLa cell growth. Anti-PT2 antibodies reduced the activity of enriched PT2 by 20-50%, but all other antisera tested exhibited no effect. Anti-PL antibodies detected antigens from Actinobacillus actinomycetemcomitans, although anti-A. actinomycetemcomitans and anti-Capnocytophaga sputigena antibodies did not react with plaque extract. These findings suggest that the plaque toxins examined in this study were probably not derived from these two bacteria.     

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.     

Platelet monoamine oxidase in healthy subjects: The “biochemical high-risk paradigm” revisited

Summary Activity of platelet monoamine oxidase (MAO) has repeatedly been reported to be associated with various forms of psychopathology. This investigation was designed to reexamine the biochemical high-risk paradigm developed by Buchsbaum et al. (1976). In 383 healthy students (193 males, 190 females) platelet MAO activity was measured. The 35 students with the lowest and 37 with the highest enzyme activities were then examined with three personality tests (16 PF of Cattell, Freiburger Persönlichkeitsinventar, Eysenck Personality Questionnaire). Furthermore, biographic data with respect to psychosocial problems were explored. There were no consistent differences between subjects with low or high platelet MAO. Therefore, we could not confirm any correlation between psychopathology and platelet MAO in this study.Supported by the Deutsche Forschungsgemeinschaft     

The relationship between emotional intelligence and initial response to a standardized periodontal treatment: a pilot study

OBJECTIVES: Emotional intelligence (EI) is a psychological construct, which has been proposed as a measure of coping mechanisms. The aim of this pilot study was to investigate the relationship between different domains of EI, and initial response to a simplified non-surgical treatment protocol in 29 patients with chronic periodontitis. METHODS: Assessment of patients included socio-demographic and behavioural variables and assessment of EI. Clinical assessment included measurement of plaque and gingival bleeding. Patients received oral hygiene instruction (OHI) and supra-gingival scaling and polishing over two visits, and re-assessed after 3 weeks. RESULTS: There was a significant overall reduction in plaque and bleeding. Plaque reduction was positively associated with the EI construct of intentionality, resilience, constructive discontent and personal power (Spearman's rank test). Reduction in bleeding was positively correlated with resilience, constructive discontent and intuition. CONCLUSIONS: This pilot study demonstrated an association between EI domains and short-term changes in plaque and bleeding, and suggest that initial responses to standardized periodontal treatment may be partly related to EI.     

Anti-gingivitis efficacy of a stabilized 0.454% stannous fluoride/sodium hexametaphosphate dentifrice

OBJECTIVE: Stannous fluoride is a broad-spectrum anti-microbial agent that has been used in dentistry as a chemical adjunct to prevent dental caries and gingivitis. The objective of this study was to assess the anti-gingivitis efficacy of a stabilized 0.454% stannous fluoride/sodium hexametaphosphate dentifrice relative to a negative control. METHODS: This was a randomized, 6-month, double-blind, parallel-group gingivitis study conducted according to the guidelines for evaluating chemotherapeutic products for the control of gingivitis outlined by the American Dental Association. A stabilized 0.454% stannous fluoride/sodium hexametaphosphate dentifrice was tested against a commercially available negative control dentifrice. Following baseline measurements, subjects received a dental prophylaxis. Subjects were then instructed to brush twice daily for 60 s using their assigned product. Oral soft-hard-tissue examinations and clinical examinations using the Modified Gingival Index, Gingival Bleeding Index, and the Turesky modification of the Quigley-Hein Plaque Index were performed at baseline, 3 and 6 months post-treatment. RESULTS: A total of 143 subjects were enrolled and 130 of them completed the 6-month study. After 6 months of product usage, the experimental group had 21.7% less gingivitis (p<0.001), 57.1% less bleeding (p<0.001), and 6.9% less plaque (p=0.01) on average compared with the negative control group. No adverse oral soft-hard-tissue effects or extrinsic tooth staining was observed in the study. CONCLUSION: The results demonstrate that use of the stabilized 0.454% stannous fluoride/sodium hexametaphosphate dentifrice over a 6-month period provided statistically significant reductions in gingivitis, gingival bleeding, and plaque when compared with a negative control dentifrice.     

Occurrence of Helicobacter pylori in dental plaque and saliva of dyspeptic patients

BACKGROUND: Helicobacter pylori infection in the stomach is associated with gastric and duodenal ulcers, gastric cancers and gastric lymphoma. The organism is transmitted by ingestion, but the oral-oral route and the fecal-oral route are also suggested. The prevalence of infection with H. pylori in developing countries, including Brazil, is higher than in developed countries. PURPOSE: This study aimed to evaluate the role of the oral cavity as a reservoir of this species, by evaluating the occurrence of H. pylori in supragingival dental plaque and in saliva of Brazilian dyspeptic patients, whether harboring the organism or not in the stomach. MATERIAL AND METHODS: Forty-nine patients reporting dyspeptic symptoms were subjected to oral clinical examination and collection of saliva and supragingival dental plaque samples prior to the endoscopic examination. The detection of H. pylori in oral samples was performed by PCR using 16S rRNA primers. The bacteria were detected in stomach by means of the rapid urease test. RESULTS: Helicobacter pylori was detected in the stomach of 20 of 49 subjects reporting dyspeptic symptoms. The organism was detected in only one supragingival plaque sample, obtained from a patient positive for the urease test in the stomach and in none of the salivary samples. CONCLUSION: Supragingival dental plaque and saliva may not be relevant reservoirs of H. pylori.