Is Gatekeeper Training Enough for Suicide Prevention?

While schools have the capacity to reach youth at-risk for suicide, there remains a gap between the number of youth with mental health issues and those who     

Arsenic association with circulating oxidized low-density lipoprotein in a Native American community

More than 500 abandoned uranium (U) mines within the Navajo Nation contribute U, arsenic (As) and other metals to groundwater, soil and potentially air through airborne transport. The adverse cardiovascular health effects attributed to cumulative exposure to these metals remains uncertain. The aim of this study was to examine whether environmental exposure to these metals may promote or exacerbate the oxidation of low-density lipoprotein (LDL) cholesterol in this Native American population. The correlation of cardiovascular biomarkers (oxidized LDL (oxLDL) and C-reactive protein (CRP)) from a Navajo cohort (n = 252) with mean annual As and U intakes from water and urine metals was estimated using linear regression. Proof-of-concept assays were performed to investigate whether As and U directly oxidize human LDL. Mean annual As intake from water was positively and significantly associated with oxLDL, but not CRP in this study population, while U intake estimates were negatively associated with oxLDL. In an acellular system, As, but not U, directly oxidized the apolipoprotein B-100 component of purified human LDL. Neither metal promoted lipid peroxidation of the LDL particle. Both the population and lab results are consistent with the hypothesis that As promotes oxidation of LDL, a crucial step in vascular inflammation and chronic vascular disease. Conversely, for outcomes related to U, negative associations were observed between U intake and oxLDL, and U only minimally altered human LDL in direct exposure experiments. Only urine U was correlated with CRP, whereas no other metals in water or urine were apparently reliable predictors of this inflammatory marker.     

Electrophoretic heterogeneity of lipopolysaccharides of Actinobacillus actinomycetemcomitans

Electrophoretic banding patterns of lipopolysaccharides (LPS), as observed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), have proved to be useful in studies relating LPS structure to virulence and as epidemiological markers. In this report, LPS of actinobacillus actinomycetemcomitans from outer membrane fractions and hot phenol-water extracts were analyzed by SDS-PAGE and LPS-specific silver-staining techniques. Both intra- and inter-strain heterogeneity of A. actinomycetemcomitans LPS was observed. Twelve strains of A. actinomycetemcomitans, representative of the three described serotypes, were assigned to LPS subtypes based on the relative mobility of their most rapidly migrating LPS band. All three serotype a strains (29523, aB75, and GA3), two (29524 and SAC11A) of five serotype b strains, and two (aB67 and SAC5A) of four serotype c strains were assigned to LPS subtype I. The three remaining serotype b strains (29522, Y4, and JP2) were assigned to LPS subtype II, and the remaining two serotype c strains (SAC6A and SAC12A) were assigned to LPS subtype III. LPS subtyping may serve as an adjunct or alternative to serotyping in epidemiological studies.     

Fluoride varnish efficacy in preventing early childhood caries

To determine the efficacy of fluoride varnish (5% NaF, Duraphat, Colgate) added to caregiver counseling to prevent early childhood caries, we conducted a two-year randomized, dental-examiner-masked clinical trial. Initially, 376 caries-free children, from low-income Chinese or Hispanic San Francisco families, were enrolled (mean age +/- standard deviation, 1.8 +/- 0.6 yrs). All families received counseling, and children were randomized to the following groups: no fluoride varnish, fluoride varnish once/year, or fluoride varnish twice/year. An unexpected protocol deviation resulted in some children receiving less active fluoride varnish than assigned. Intent-to-treat analyses showed a fluoride varnish protective effect in caries incidence, p < 0.01. Analyzing the number of actual, active fluoride varnish applications received resulted in a dose-response effect, p < 0.01. Caries incidence was higher for 'counseling only' vs. 'counseling + fluoride varnish assigned once/year' (OR = 2.20, 95% CI 1.19-4.08) and 'twice/year' (OR = 3.77, 95% CI 1.88-7.58). No related adverse events were reported. Fluoride varnish added to caregiver counseling is efficacious in reducing early childhood caries incidence.     

Antibacterial treatment needed for severe early childhood caries

OBJECTIVES: To assess the effects of a single 10% povidone iodine application as an adjunct to extensive surgical procedures in the clinical treatment of children with early childhood caries. METHODS: Twenty-two children scheduled for dental treatment under general anesthesia were randomized into either an intervention group (10% povidone iodine), or a control group (phosphate buffered saline). Either povidone iodine or phosphate buffered saline was applied to teeth and soft tissues after prophylaxis and all operative dental procedures, followed by 1.23% acidulated phosphate fluoride gel. Saliva samples taken at baseline, and after 1 hour, 3 weeks and 3 months were assayed for mutans streptococci, lactobacilli and total viable bacteria. Caries lesions were recorded at baseline and at one year. RESULTS: Mutans streptococci and lactobacilli levels in the povidone iodine group were significantly reduced relative to baseline at 1 hour, 3 weeks and 3 months. At one year at least 60% of subjects had new caries lesions in each group, and there was no significant difference in caries increment between the two groups. CONCLUSIONS: Even prophylaxis, fluoride gel application and complete surgical treatment of caries at baseline were insufficient to prevent new caries in over 60% of the patients in these high caries risk infants. Although the one-time treatment with povidone iodine reduced mutans streptococci and lactobacilli levels for up to 3 months this therapy failed to additionally reduce future caries formation over one year, indicating that repeated antibacterial treatments will be needed to control high levels of cariogenic bacteria.