The role of surface sealants in the roughness of composites after a simulated toothbrushing test

Objectives

To evaluate the influence of two surface sealants (BisCover/Single Bond) and three application techniques (unsealed/conventional/co-polymerization) on the roughness of two composites (Filtek Z250/Z350) after the toothbrushing test.

Methods

Seventy-two rectangular specimens (5 mm × 10 mm × 3 mm) were fabricated and assigned into 12 groups (n = 6). Each sample was subjected to three random roughness readings at baseline, after 100,000 (intermediate), and 200,000 (final) toothbrushing strokes. Roughness (R) at each stage was obtained by the arithmetic mean of the reading of each specimen. Sealant removal was qualitatively examined (optical microscope) and classified into scores (0–3). Data were analyzed by Student's paired t-test, two-way ANOVA/Tukey's test, and by Wilcoxon, Kruskal–Wallis and Miller's test (α = 0.05).

Results

Z250 groups at baseline did not differ statistically from each other. Unsealed Z350 at baseline had lower R values. All the unsealed groups presented gradual decrease in R from baseline to final brushing. From baseline to the intermediate stage, Z250 co-polymerized groups presented a significant reduction in R (score 3). Conventionally sealed groups had no significant changes in R (scores 2–0.8). From baseline to the intermediate stage, the conventionally sealed Z350 Single Bond group had an increase in R (score 1.5). In the final stage, all the conventionally sealed groups presented a reduction in R (scores 0.7–0). Co-polymerized Single Bond groups had a significant reduction in R (scores 2.5–2.7), and co-polymerized BisCover groups an increase in R (scores 2.8–3).

Conclusions

At any brushing stage, sealed composites presented superior performance when compared with unsealed composites.     

系统性红斑狼疮病人用氟达拉滨治疗后引发输血相关的GVHD

输血相关GVHD是一种发病率低但却致命的输血并发症,它以存在于血液制品中含有免疫能力的异体淋巴细胞所介导,在受者体内植活、增殖,进而引起严重攻击和破坏宿主体内细胞和组织的免疫反应。发展成TA-GVHD的危险因素包括宿主严重免疫缺陷,或者是由白血病、淋巴瘤、先天性免疫缺陷病、新生儿,或者是作为造血干细胞预处理程序中的细胞毒或     

Phase II trial of tipifarnib and radiation in children with newly diagnosed diffuse intrinsic pontine gliomas

We performed a phase II study to assess the efficacy and toxicity of tipifarnib, a farnesyltransferase inhibitor, administered with radiation therapy (RT) in children with newly diagnosed diffuse intrinsic pontine gliomas. Children 3-21 years old with pontine gliomas (BSGs) were treated with concurrent tipifarnib and RT, followed by adjuvant tipifarnib. Tipifarnib was taken orally twice daily (125 mg/m(2)/dose) during RT; after RT, it was taken at 200 mg/m(2) twice daily for 21 days, in 28-day cycles. Initial and follow-up neuroimaging was centrally reviewed. Forty eligible patients (median age, 5.5 years; range, 3.3-16.5 years) had a median progression-free survival of 6.8 months (range, 0.2-18.6 months) and median overall survival of 8.3 months (range, 0.2-18.6 months). Kaplan-Meier estimates (± standard error) of 1-year progression-free and overall survival were 12.9% ±4.9% and 34.3% ±7.4%, respectively. A single patient remained on tipifarnib without progression at the completion of the study, two years after initiation of treatment. Seven patients were without disease progression for at least six months, three of whom remained controlled for more than a year. The most frequent toxicity was grade 3 lymphopenia. We documented a single instance of "pseudoprogression" by neuroimaging review. We found no discordance among 3 approaches to defining disease progression: as interpreted by treating institutions (based on clinical status and/or imaging) and by central review (using bi-dimensional tumor "area" versus volumetric measurements). For children with diffuse BSGs, tipifarnib administered with irradiation offered no clinical advantage over historical controls. Biopsies and molecular analyses of pediatric BSGs are vital for identification of new agents and for rational use of targeted agents.     

A case report of herpetic and candidal esophagitis in an immunocompetent adult

Reports of combined candidal and herpetic esophagitis in immunocompetent states are rare and sporadic. A 44-year-old previously healthy lady presented with a one week history of progressive dysphagia, odynophagia and fever. Esophagogastroduodenoscopy (EGD) showed extensive desquamation of the entire esophagus except for distal 4 cm. Histopathological examination revealed ulcerated and inflamed squamous epithelium with the margin of ulcer showing a few overhanging squamous cells with dense eosinophilic cytoplasm, multinucleated and faceted nuclei with glassy chromatin, and an occasional Cowdry type A intranuclear inclusion bodies. Few candidal spores were seen in the underlying stroma. Intravenous acyclovir, fluconazole and pantoprazole were initiated. Oral analgesics were given for pain relief. She was treated for a total of 14 days. She showed significant improvement and was tolerating oral intake after discharge. The patient was asymptomatic with no evidence of recurrence at a 2-month follow-up.     

The timing of hepatitis B virus (HBV) immunization relative to human immunodeficiency virus (HIV) diagnosis and the risk of HBV infection following HIV diagnosis

To assess associations between the timing of hepatitis B virus (HBV) immunization relative to human immunodeficiency virus (HIV) diagnosis and vaccine effectiveness, US Military HIV Natural History Study cohort participants without HBV infection at the time of HIV diagnosis were grouped by vaccination status, retrospectively followed from HIV diagnosis for incident HBV infection, and compared using Cox proportional hazards models. A positive vaccine response was defined as hepatitis B surface antibody level ≥ 10 IU/L. Of 1,877 participants enrolled between 1989 and 2008, 441 (23%) were vaccinated prior to HIV diagnosis. Eighty percent of those who received vaccine doses only before HIV diagnosis had a positive vaccine response, compared with 66% of those who received doses both before and after HIV and 41% of those who received doses only after HIV (P < 0.01 for both compared with persons vaccinated before HIV only). Compared with the unvaccinated, persons vaccinated only before HIV had reduced risk of HBV infection after HIV diagnosis (hazard ratio = 0.38, 95% confidence interval: 0.20, 0.75). No reduction in HBV infection risk was observed for other vaccination groups. These data suggest that completion of the vaccine series prior to HIV infection may be the optimal strategy for preventing this significant comorbid infection in HIV-infected persons.     

Status of research on matrix metalloproteinases (MMPs) in India

INTRODUCTION: MMPs are extracellular matrix (ECM)-degrading enzymes that play a crucial role in embryogenesis, tissue remodeling, inflammation and angiogenesis. MMP-2 and -9 (also called type 2 and type 4 collagenase, or gelatinase A and B) are the key molecules that control invasion, tumor growth and metastasis. Tissue inhibitor of matrix metalloproteinase (TIMP) -2 and -1 are specific inhibitors of MMP-2 and MMP-9 respectively, and play a crucial role in regulation of MMP-2 and -9 activation, during pathophysiological processes. MMPs can specifically degrade native gelatin, collagens, fibronectin, ectactin and elastin. MMP-2 and -9 are overexpressed in almost all types of cancers, and so act as important therapeutic targets. AREAS COVERED: The status of MMP research in India from 1998 to 2010. In this review, the authors cover the role of matrix metalloproteinase inhibitors in cancer therapy. EXPERT OPINION: As compared with other parts of the world, Indian scientists have not generated a significant number of specific MMP inhibitors for the treatment of cancer, or other diseases. MMPs and membrane type (MT)-MMPs are potentially important therapeutic targets in many diseases, including cancers, therefore, designing specific inhibitors from natural products or through synthetic routes, is crucial.