Cellular immunity and hypersensitivity as components of periodontal destruction

BACKGROUND: Cellular immunity has been implicated in periodontal destruction for over 25 years. Studies in the 1970s used lymphocyte transformation and lympho-kine assays to establish a role for cell-mediated mechanisms in periodontal disease. lmmunohistological studies subsequently showed that the formation of gingivitis followed a similar pattern to the formation of a delayed type hypersensitivity reaction. Further functional studies suggested that a T cell/macrophage immunoregulatory imbalance may exist locally in the periodontitis lesion and that this imbalance may be antigen specific. RECENT EVIDENCE: More recently, T cell subsets have been dichotomised on the basis of their cytokine profiles. In general, Thl cells produce IL-2 and IFN-gamma while Th2 cells produce IL-4, IL-5 and IL-6. The major function of Th l cells is to mediate delayed type hypersensitivity. In contrast the major function of Th2 cells is to provide B cell help.
HYPOTHESIS: A model for periodontal disease has now been developed based on this functional dichotomy which provides a framework for the study of cytokine profiles in periodontal disease. Early studies in this context have demonstrated a higher proportion of IL-4 producing cells in periodontitis tissues suggesting a role for Th2 cells in the progressive lesion. Clonal studies have shown that the selection of a particular cytokine profile is not antigen dependent and that differences may be due to the host susceptibility although this remains to be determined.
CONCLUSION: These emerging data clearly establish a role for cell-mediated mechanisms in the control of periodontal destruction and raise the possibility that in the future cytokine therapy for the treatment of periodontal disease in susceptible subjects may become a viable option.     

Dissolution of porcine incisor pulps in sodium hypochlorite solutions of varying compositions and concentrations

BACKGROUND: The solubility of dental pulp tissue in sodium hypochlorite has been extensively investigated but results have been inconsistent; due most likely to variations in experimental design, the volume and/or rate of replenishment of the solutions used and the nature of the tissues assessed. Traditionally, the sodium hypochlorite solutions used for endodontic irrigation in Australia have been either Milton or commercial bleach, with Milton being the most common. Recently, a range of Therapeutic Goods Administration (TGA) approved proprietary sodium hypochlorite solutions, which contain surfactant, has become available. Some domestic chlorine bleaches now also contain surfactants. The purpose of this study was to perform new solubility assessments, comparing Milton with new TGA approved products, Hypochlor 1% and Hypochlor 4% forte, and with a domestic bleach containing surfactant (White King). METHODS: Ten randomly assigned pulp samples of porcine dental pulp of approximately equal dimensions were immersed in the above solutions, as well as representative concentrations of sodium hydroxide. Time to complete dissolution was measured and assessed statistically. RESULTS: White King 4% showed the shortest dissolution time, closely followed by Hypochlor 4% forte. White King 1% and Hypochlor 1% each took around three times as long to completely dissolve the samples of pulp as their respective 4% concentrations, while Milton took nearly 10 times as long. The sodium hydroxide solutions showed no noticeable dissolution of the pulp samples. CONCLUSIONS: The composition and content of sodium hypochlorite solutions had a profound effect on the ability of these solutions to dissolve pulp tissue in vitro. Greater concentrations provided more rapid dissolution of tissue. One per cent solutions with added surfactant and which contained higher concentrations of sodium hydroxide were significantly more effective in dissolution of pulp tissue than Milton.     

Haploidentical Bone Marrow Transplantation with Post-Transplant Cyclophosphamide Using Non–First-Degree Related Donors

Outcomes of nonmyeloablative (NMA) haploidentical (haplo) blood or marrow transplant (BMT) with post-transplantation cyclophosphamide (PTCy) using non–first-degree relatives are unknown. We evaluated 33 consecutive adult patients (median age, 56 years) with hematologic malignancies who underwent NMA haplo T cell–replete BMT with PTCy at Johns Hopkins using second- or third-degree related donors. Donors consisted of 10 nieces (30%), 9 nephews (27%), 7 first cousins (21%), 5 grandchildren (15%), and 2 uncles (6%). Thirty-one patients (94%) reached full donor chimerism by day 60. The estimated cumulative incidence (CuI) of grades II to IV acute graft-versus-host disease (aGVHD) at day 180 was 24% (90% confidence interval [CI], 9% to 38%). Only 1 patient experienced grades III to IV aGVHD. At 1 year the CuI of chronic GVHD was 10% (90% CI, 0% to 21%). The CuI of nonrelapse mortality at 1 year was 5% (90% CI, 0% to 14%). At 1 year the probability of relapse was 31% (90% CI, 12% to 49%), progression-free survival 64% (90% CI, 48% to 86%), and overall survival 95% (90% CI, 87% to 100%). The 1-year probability of GVHD-free, relapse-free survival was 57% (90% CI, 41% to 79%). NMA haplo BMT with PTCy from non–first-degree relatives is an acceptably safe and effective alternative donor platform, with results similar to those seen with first-degree relatives.     

大学生静态平衡能力与运动及性别的关系:定量对比分析

目的:采用定量分析方法比较体育与非体育专业大学生静态平衡能力,分析运动及性别对大学生静态平衡功能的影响。方法:于2007-01/03选取首都体育学院在校大学生共78名为受试对象,其中体育(武术)专业学生40名,非体育(康复)专业学生38名。所有选取对象了解试验目的,并同意参与本实验。采用意大利PosturalEqua平静分析系统,对实验对象分别在睁眼60s、闭眼60s两种状态下测试其静态平衡的各项指标,包括压力中心,线形图总长度,最大摆幅,线形图面积,LFS指数,压力分布,稳定性图及隆伯格值。结果:78名为受试对象均进入结果分析。①两专业学生压力中心X轴短于Y轴、压力分布前(%)高于后(%)(P<0.01)。②在闭眼状态下,体育专业男大学生在指标LFS指数和额状面上大于非体育专业(P<0.05)。③非体育业大学生在睁眼状态下,Y值女性小于男性,额状面值女性大于男性。男、女生睁闭眼差值进行比较时,女性在线形图总长度、额状面和LFT指数均大于男性(P<0.01),而线形图面积小于男性(P<0.05)。④体育专业大学生在睁眼状态下,指标参数Y值女性小于男性,额状面值女性大于男性;闭眼状态下,指标参数Y值女性小于男性,额状面值和LFS值女性大于男性。男、女生睁闭眼差值比较,女性在线形图总长度、额状面和LFT指数均大于男性(P<0.05,P<0.01),而线形图面积小于男性(P<0.05)。结论:①运动训练对大学生静态平衡影响不大,但对男性大学生的某些平衡指标却有显著影响。②性别对大学生的静态平衡均产生影响,表现为男性平衡的微控制能力优于女性。     

Donor screening for antibody to hepatitis B core antigen and hepatitis B virus infection in transfusion recipients

BACKGROUND: Testing for antibody to hepatitis B core antigen (anti-HBc) as a surrogate for hepatitis C viremia is no longer needed for blood donor screening. Currently, the important question is how much its use supplements hepatitis B surface antigen (HBsAg) donor screening in preventing transfusion-transmitted hepatitis B virus (HBV) infection. STUDY DESIGN AND METHODS: In a study conducted in the 1970s, 64 blood donors were associated with 15 cases of HBV (1.0%) in 1533 transfusion recipients. Sera from 61 donors at donation and 29 follow-up visits were available for present-day assays for HBsAg, HBV DNA, anti-HBc, and antibody to HBsAg (anti-HBs). RESULTS: HBsAg was found in four previously negative blood donors; HBV DNA was limited to three of these four. Anti-HBc was detected in six HBsAg-negative donors. Two other donors were negative in all assays at donation, but positive for anti- HBc and anti-HBs 2 to 4 months later. The remaining donors were negative for all HBV markers, which left five recipient cases unexplained. No HBV transmission was observed when anti-HBs sample-to- negative control values were > or = 10. CONCLUSION: Some 33 to 50 percent of cases of hepatitis B that could be transmitted by transfusion of blood from HBsAg-negative donors are prevented by anti- HBc screening. Anti-HBc-positive donors unequivocally positive for anti- HBs should be considered noninfectious for HBV and should be allowed to donate. Anti-HBc screening of paid plasmapheresis donors, supplemented by anti-HBs testing, would reduce the amount of HBV to be processed by virus inactivation and increase the content of anti-HBs in plasma pools.