Interaction of Inflammatory Cells and Oral Microorganisms VII. In Vitro Polymorphonuclear Responses to Viable Bacteria and to Subcellular Components of Avirulent and Virulent Strains of Actinomyces viscosus

Both virulent (V) and avirulent (AV) strains of Actinomyces viscosus T14 are capable of colonizing the oral cavity of gnotobiotic rats, but only T14-V causes destructive periodontal disease. The basis for this difference in in vivo pathogenicity has not been adequately defined. In the present study we compared the capacities of T14-AV and T14-V to provoke in vitro extracellular release of lysosomal constituents from human polymorphonuclear leukocytes (PMNs). In serum-free cultures, viable T14-V but not T14-AV stimulated discharge of PMN lysosomes. The release response was correlated with PMN phagocytic activity; thus, PMNs readily ingested T14-V but not T14-AV. To explain these differences in PMN-bacteria interactions, subcellular fractions of T14-AV or T14-V were incubated with PMNs. A crude, insoluble sonic extract derived from T14-V caused PMN lysosome release, but a similar fraction from T14-AV was inactive. However, following extensive washing and treatment with deoxyribonuclease or sodium dodecyl sulfate, cell wall fractions of T14-AV stimulated lysosome release. These procedures apparently removed an extracellular polysaccharide slime which is synthesized by T14-AV but not by T14-V. There was a significant reduction in the capacities of viable T14-V or cell wall fractions of T14-V or T14-AV to provoke PMN lysosome release when these agents were preincubated with a slime material isolated from T14-AV. This inhibitory influence of slime was overcome by the addition of fresh or heated (56°C, 30 min) serum to the PMN-bacteria cultures. The data suggest a relationship between the abilities of the avirulent and virulent strains of A. viscosus T14 to act as periodontal pathogens in vivo and to serve as stimuli for PMN lysosome release in vitro.     

Potential role of vascular endothelial growth factor,interleukin-8 and monocyte chemoattractant protein-1 in periodontal diseases

Host-mediated immunoinflammatory pathways activated by bacteria lead to destruction of the periodontal connective tissues and alveolar bone. The objective of this study was to elucidate the activation of the inflammatory processes in periodontal disease by quantitative assessment of cytokines and periodontopathogens. Gingival crevicular fluids (GCF) and subgingival plaque samples were collected from patients with chronic periodontitis and gingivitis and from periodontally healthy sites. Vascular endothelial growth factor (VEGF), monocyte chemoattractant protein-1 (MCP-1), and interleukin 8 (IL-8) in GCF were analyzed by enzyme-linked immunosorbent assay. Periodontopathogens, including Bacteroides forsythus, Campylobacter rectus, Porphyromonas gingivalis and Prevotella intermedia, were analyzed by immunofluorescence and dark-field microscopy. There was significantly more VEGF and IL-8 in chronic periodontitis and gingivitis sites than in periodontally healthy sites. There were significant positive correlations between the concentrations and total amounts of VEGF and IL-8 in chronic periodontitis and gingivitis sites, and between the levels of periodontopathogens and the total amounts of VEGF, MCP-1 and IL-8. These data indicate that inflammatory processes induced by periodontopathogens and the activation of certain cytokines (VEGF, MCP-1, IL-8) in periodontal diseases may be relevant to host-mediated destruction in chronic periodontitis.     

Evaluation of a rapid test for the detection of antibodies to human immunodeficiency virus type 1 and 2 in the setting of multiple transmitted viral subtypes

Rapid HIV testing is an appealing strategy in the approach to HIV diagnosis in developing countries. Concern has been raised about the use of these tests in the setting of multiple transmitted HIV subtypes. We sought to compare the OraQuick(TM) HIV-1/2 Test, a qualitative immunochromatographic test for the detection of antibodies to HIV-1 and HIV-2 using stored sera, with a conventional enzyme immunoassay (EIA)/Western blot (WB) algorithm. The study design used was a blinded retrospective study. Samples were collected on patients attending sexually transmitted disease clinics and tuberculosis clinics in Kinshasa, the Democratic Republic of Congo and included 72 known HIV seropositive and 131 known HIV seronegative subjects. All 72 known HIV seropositive samples were positive by OraQuick and all 131 known HIV seronegative samples were negative by OraQuick resulting in 100% sensitivity and specificity. We conclude that the OraQuick rapid HIV-1/2 test performs well in the setting of diverse HIV viral subtypes.     

Laparoscopic common bile duct exploration with T-tube choledochotomy for the management of choledocholithiasis

Although laparoscopic cholecystectomy (LC) has become the gold standard for the management of gallstone disease, the application of laparoscopic common bile duct exploration (LCBDE) for choledocholithiasis has been slower. The aim of this study is to determine the feasibility and effectiveness of LCBDE. A retrospective cohort study was conducted to compare LCBDE (n = 82) with conventional common bile duct exploration (CCBDE) (n = 75) and endoscopic sphincterotomy (EST) (n = 80) in the management of choledocholithiasis. All our LCBDEs were performed through choledochotomy with T-tube placement. The mean operative time of the LCBDE group (124 +/- 48 minutes) was not significantly longer then the CCBDE group (118 +/- 35 minutes), while the postoperative hospitalization was shorter in both the LCBDE (8 +/- 5 days) and EST (9 +/- 4 days) groups than in the CCBDE (13 +/- 6 days) group. In the LCBDE group, 14 patients (17.1%) required postoperative choledochoscopy to clear residual stones through the T-tube tract. The only mortality occurred in the CCBDE group. The morbidity rate was 3.7% (3/82) in the LCBDE group, including bile leakage in 1 case and bile peritonitis in 2 cases; 6.7% (5/75) in the CCBDE group, including atlectasis in 2 cases, sepsis in 1, and wound infection in 2. There were 2 cases of postoperative pancreatitis (2.5%; 2/80) in the EST group. The difference in the average number of sessions needed for complete clearance of choledocholithiasis in each group was statistically significant (EST, 1.46 +/- 0.67; LCBDE, 1.23 +/- 0.42; and CCBDE, 1.09 +/- 0.28; P < 0.0001). Our results suggested that EST and LCBDE tended to require more therapeutic sessions then CCBDE, although these sessions were less invasive. The benefits of LCBDE include minimal invasiveness, concurrent treatment of gallbladder stone and CBD stones in a single session, and a shorter postoperative hospital stay. However a longer learning curve is needed. Selection of the most suitable therapeutic option for individual patients by an experienced surgeon gives the most benefits to patients.     

Treatment of intrabony defects associated with interradicular root proximity/fusion in molar furcations

To treat furcation involvement is a crucial challenge to periodontists, not only because of the limitation in pocket reduction by osteoplasty and apically positioned flap, but also because of the unpredictability in regenerative approaches. Therefore, if the first molar is absent and the second molar has to be retained strategically for prosthetic reasons, very few alternatives besides nonsurgical/surgical debridement can be taken in treating the furcation of the second molar, where the interradicular root proximity and fusion frequently occur. On the other hand, root amputation/hemisection has long been considered a contraindication in treating furcations with two close roots; however, this impression is only empirical. A series of clinical cases involved in the treatment of intrabony defects associated with interradicular root proximity and fusion by root amputation/hemisection has been reported. Without any help of regenerative material, thorough root debridement and pocket reduction were attained. Based on these cases, we suggested that the cut surface created by odontoplasty during root amputation was compatible for periodontal healing and the extraction socket provided striking potential for defect repair. We re-examined the clinical feasibility and benefit of treating intrabony defects associated with interradicular root proximity and fusion in molar furcations by root amputation/hemisection, and suggested that its role should be favorably reconsidered on case basis. The short-term success in periodontal and prosthetic aspects needed to be further evaluated at long-term follow-up.     

Stereotactic radiosurgery for locally recurrent nasopharyngeal carcinoma

BACKGROUND: Stereotactic radiosurgery has been used to treat intracranial tumors. Recently, it has also been used for the treatment of head and neck tumors involving the base of skull, including recurrent NPC. METHODS: From October 1994 to April 1999, 36 patients with recurrent NPC, were retreated by stereotactic radiosurgery. These patients received radiosurgery as a boost treatment after reirradiation for recurrence. The external RT dose ranged from 20 to 60 Gy. The tumor volume ranged from 3.58 to 24.6 cc. The target surface dose ranged from 8 to 20 Gy. The median follow-up was 22.1 months. RESULTS: The 3-year local control rate was 56%. The 5-year overall survival was 49%. Persistence after radiosurgery had a worse survival than those who had secondary recurrence. Age and gender were marginally significant. No patient had new severe complications after retreatment. Four patients (11%) had nasopharyngeal necrosis after radiosurgery, none had nasal bleeding or headache, but a foul odor was present in one patient. CONCLUSIONS: Conformal radiotherapy and stereotactic radiotherapy provide good local control and survival without severe complications for patients with recurrent NPC.     

Prevalence of LMP-1 gene in tonsils and non-neoplastic nasopharynxes by nest-polymerase chain reaction in Taiwan

BACKGROUND: The purpose of this study was to investigate the frequency of Epstein-Barr virus (EBV) latent membrane protein-1 (LMP-1) in tonsils and non-neoplastic nasopharynxes in Taiwan. METHODS: Nest-polymerase chain reaction (nest-PCR) was used to examine the presence of LMP-1 gene in lymphoid hyperplasia from non-neoplastic tonsillar and nasopharyngeal tissues and in tonsillar cancers. RESULTS: In 152 cases, 64 biopsy tissues were obtained from lymphoid hyperplasia of nasopharynxes, 57 from tonsillectomy of non-neoplastic tonsils, and 31 from tonsillar cancers. LMP-1 was detected in 43.4% of the study group. Nineteen (29.7%) and 29 (50.9%) lymphoid hyperplasias from normal nasopharynxes and tonsils, respectively, and 18 (58.1%) biopsies from tonsillar cancers had positive LMP-1. The 30-base pair (bp) deleted variant was detected in 89.5% and 82.8% of normal nasopharynxes and tonsils, respectively, and in 66.7% of biopsies from tonsillar cancers (p =.198). CONCLUSION: This study found that the 30-bp variant was the predominant type of LMP-1 from a healthy population in Taiwan.     

临界性高血压患者昼夜血压变化的流行病学特征研究

目的研究临界性高血压患者昼夜血压变化,探讨该人群的流行病学特点。方法选取50例临界性高血压患者,配带无创性携带式血压监测仪,分M1(9:00～20:00),M2(21:00～5:00),M3(6:00～8:00)3个时间段连续监测24h血压。结果①24h平均血压(134±13)/(91±8)mmHg,白昼平均舒张压(93±9)mmHg及夜间血压平均值(125±19)/(84±11)mmHg比正常人明显增高(P<0.001),而白昼收缩压平均值与正常人无显著差异(P>0.05);②M1及M3时段收缩压舒张压均值明显高于M2(P<0.001);③24h最高、最低收缩压舒张压差值较大,犤分别为(177～109)/(103～53)mmHg犦;④舒张压负荷值均>10%(M354.7%,M149.3%,M222.1%)。结论①临界高血压患者昼夜血压变化较大,随测血压较难做出正确诊断;②由于昼夜血压波动范围较大(脉压值增大),易致心、脑、肾等靶器官损害,因此应重视对临界高血压的及早控制。