Predictors and outcomes of ischemic stroke in reversible cerebral vasoconstriction syndrome

Journal of Neurology - The clinical factors predisposing to ischemic stroke in reversible cerebral vasoconstriction syndrome (RCVS) are unclear. In this observational cross-sectional study, we...     

Longitudinal caries prevalence in a comprehensive,multicomponent, school-based prevention program

BackgroundGlobally, children’s caries prevalence exceeds 30% and has not markedly changed in 30 years. School-based caries prevention programs can be an effective method to reduce caries prevalence, obviate traditional barriers to care, and use aerosol-free interventions. The objective of this study was to explore the clinical effectiveness of a comprehensive school-based, aerosol-free, caries prevention program.MethodsThe authors conducted a 6-year prospective open cohort study in 33 US public elementary schools, providing care to 6,927 children in communities with and without water fluoridation. After dental examinations, dental hygienists provided twice-yearly prophylaxis, glass ionomer sealants, glass ionomer interim therapeutic restorations, fluoride varnish, toothbrushes, fluoride toothpaste, oral hygiene instruction, and referral to community dentists as needed. The authors used generalized estimating equations to estimate the change in the prevalence of untreated caries over time.ResultsThe prevalence of untreated caries decreased by more than 50%: from 39% through 18% in phase 1, and from 28% through 10% in phase 2. The per-visit adjusted odds ratio of untreated caries was 0.79 (95% confidence interval, 0.73 to 0.85).Conclusions and Practical ImplicationsThis school-based comprehensive caries prevention program was associated with substantial reductions in children’s untreated caries, supporting the concept of expanding traditional practices to include office- and community-based aerosol-free care.     

Fc gamma receptor II (CD32) on malignant B cells influences modulation induced by anti-CD19 monoclonal antibody

Antigenic modulation is one of many factors determining the effectiveness of monoclonal antibody (MoAb)-mediated therapy. To select the isotype of a CD19 MoAb most suitable for radioimmunotherapy of patients with B-cell malignancies, we studied the influence of MoAb isotype on modulation, after binding of the MoAb to different cell-line cells. The CD19-IgG1 MoAb was found to induce modulation of CD19 antigens on Daudi cell line cells more rapidly than did its IgG2a switch variant. We provide evidence that this difference in modulation rate is caused by the expression of Fc gamma receptor II (Fc gamma RII) on these cells. Experiments aimed at elucidating the mechanism of Fc gamma RII involvement in modulation induction by CD19-IgG1 showed that Fc gamma RII did not comodulate with CD19 MoAbs. However, cocrosslinking of CD19 and Fc gamma RII with CD19-IgG1 MoAb resulted in enhanced calcium mobilization in Daudi cells. This increased signal induction accompanies the enhanced capping and subsequent modulation of CD19 antigens. Because Fc gamma RII is expressed in varying densities on malignant B cells in all differentiation stages, our results have implications for the MoAb isotype most suitable for use in MoAb-based therapy of patients with B-cell malignancies.     

A radioreceptor assay for quantitating plasma factor VIII/von Willebrand's protein

A sensitive and precise radioreceptor assay for determining plasma levels of human factor VIII/von Willebrand's factor (FVIII/vWF) has been developed by taking advantage of the FVIII/vWF receptor sites on human platelets. Paraformaldehyde-fixed platelets, which were processed and then stored, retained FVIII/vWF binding activity and therefore could be used as a convenient source of receptors. The human plasma samples to be tested were initially filtered on 4% agarose columns to concentrate the FVIII/vWF protein in the void volume and to remove the factor(s) that interferes with the assay. The percent recovery of FVIII/vWF in the pooled eluent was measured by the recovery of added trace 125I-FVIII/vWF. The coefficients of intra- and interassay variation were 6% and 10%, respectively. The plasma FVIII/vWF concentrations determined by the assay for pooled normal plasma, hemophilia A plasma, and plasmas from two patients with von Willebrand's disease were 16.3 +/- 0.5, 52.6 +/- 1.5, 6.8 +/- 0.8, and 3.2 +/- 0.2 microgram/ml, respectively. The range of plasma FVIII/vWF concentrations varied between 8.3 microgram/ml and 24.9 microgram/ml for 10 normal adults. The plasma FVIII/vWF concentrations determined by the radioreceptor assay correlated well with levels measured by the ristocetin-induced platelet aggregation method, thus demonstrating the functional relevancy of the radioreceptor assay for plasma FVIII/vWF.     

Effects of Azithromycin,Metronidazole, Amoxicillin,and Metronidazole plus Amoxicillin on an In Vitro Polymicrobial Subgingival Biofilm Model

Chronic periodontitis is one of the most prevalent human diseases and is caused by dysbiosis of the subgingival microbiota. Treatment involves primarily mechanical disruption of subgingival biofilms and, in certain cases, adjunctive use of systemic antibiotic therapy. In vitro biofilm models have been developed to study antimicrobial agents targeting subgingival species. However, these models accommodate a limited number of taxa, lack reproducibility, and have low throughput. We aimed to develop an in vitro multispecies biofilm model that mimics subgingival plaque, to test antimicrobial agents. Biofilms were cultivated using the Calgary Biofilm Device and were exposed to amoxicillin (AMX), metronidazole (MTZ), azithromycin (AZM), and AMX-MTZ at four different concentrations for 12, 24, or 36 h. Chlorhexidine (CHX) (0.12%) was used as the positive control. The compositions of the biofilms were analyzed by checkerboard DNA-DNA hybridization, and the percent reduction in biofilm metabolic activity was determined using 2,3,5-triphenyltetrazolium chloride and spectrophotometry. Thirty-five of the 40 species used in the inoculum were consistently recovered from the resulting in vitro biofilms. After 36 h of exposure at the 1:27 dilution, AMX-MTZ reduced metabolic activity 11% less than CHX (q = 0.0207) but 54% more than AMX (q = 0.0031), 72% more than MTZ (q = 0.0031), and 67% more than AZM (q = 0.0008). Preliminary evidence of a synergistic interaction between AMX and MTZ was also observed. In summary, we developed reproducible biofilms with 35 subgingival bacterial species, and our results suggested that the combination of AMX and MTZ had greater antimicrobial effects on these in vitro multispecies biofilms than expected on the basis of the independent effects of the drugs.     

Associations Between Sex Hormone Levels and Periodontitis in Men: Results From NHANES III

Background: Sex hormones are linked to inflammation and bone turnover. The goal of this study is to explore the association between sex hormone levels and periodontitis in men using data from the third National Health and Nutrition Examination Survey (NHANES III). Methods: Data from 755 men (aged ≥30 years), including serum levels of testosterone, estradiol, sex hormone binding globulin, and androstenediol glucuronide, were analyzed. Calculated bioavailable testosterone (CBT) and estradiol‐to‐testosterone ratio were calculated. Periodontitis was defined using the latest classification of extent and severity of periodontitis for NHANES data (≥2 interproximal sites with ≥3 mm attachment loss, ≥2 interproximal sites with probing depth [PD] ≥4 mm not on the same tooth, or one site with PD ≥5 mm). Sex hormones were evaluated as categorized and continuous variables. Correlations between the presence and severity of periodontitis and levels of sex hormones were determined and expressed as odds ratios (ORs). Results: When adjusted for confounding factors, high total testosterone (TT) and CBT levels correlated with both the prevalence (OR [95% confidence interval (CI)], 2.1 [1 to 4.5] and 3.9 [1 to 14.8], respectively) and severity (OR [95% CI], 2.1 [1 to 4.3] and 3.4 [1.2 to 9.8]) of periodontitis. When continuous variables were used, the ORs (95% CIs) for presence and severity of periodontitis were 1.4 (0.6 to 3.3) and 1.5 (0.6 to 3.6) for TT and 1.3 (0.9 to 1.9) and 1.3 (0.9 to 1.8) for CBT, respectively. Conclusions: These findings are consistent with the existence of an association of periodontitis with sex hormone levels, especially testosterone, in men.     

Spatiotemporal distribution of cortical processing of first and second languages in bilinguals. I. Effects of proficiency and linguistic setting

The study determined how spatiotemporal distribution of cortical activity to words in first and second language is affected by language, proficiency, and linguistic setting. Ten early bilinguals and 14 late adult bilinguals listened to pairs of words presented in Arabic (L1), Hebrew (L2), or in mixed pairs and indicated whether both words had the same meaning or not. Source current densities of event‐related potentials were estimated. Activity to first words in the pair lateralized to right hemisphere, higher to L1 than L2 during early processing (<300 ms) among both groups but only among late bilinguals during late processing (>300 ms). During early and late processing, activities were larger in mixed than monolinguistic settings among early bilinguals but lower in mixed than in monolinguistic settings among late bilinguals. Late processing in auditory regions was of larger magnitude in left than right hemispheres among both groups. Activity to second words in the pair was larger in mixed than in monolinguistic settings during both early and late processing among both groups. Early processing of second words in auditory regions lateralized to the right among early bilinguals and to the left among late bilinguals, whereas late processing did not differ between groups. Wernicke's area activity during late processing of L2 was larger on the right, while on the left no significant differences between languages were found. The results show that cortical language processing in bilinguals differs between early and late processing and these differences are modulated by linguistic proficiency and setting. Hum Brain Mapp 34:2863–2881, 2013. © 2012 Wiley Periodicals, Inc.