Snake bites by the jararacucu (Bothrops jararacussu): clinicopathological studies of 29 proven cases in Sao Paulo State, Brazil

The jararacucu, one of the most dreaded snakes of Brazil, southern Bolivia, Paraguay and northeastern Argentina, is a heavily-built pit viper which may grow to a length of 2.2 m. Up to 1000 mg (dry weight) of highly-lethal venom may be milked from its venom glands on a single occasion. It has accounted for 0.8% to 10% of series of snake bites in Sao Paulo State, Brazil. We examined 29 cases of proven jararacucu bites recruited over a 20-year period in two Sao Paulo hospitals. Severe signs of local and systemic envenoming, (local necrosis, shock, spontaneous systemic bleeding, renal failure) were seen only in patients bitten by snakes longer than 50 cm; bites by shorter specimens were more likely to cause incoagulable blood. Fourteen patients developed coagulopathy, six local necrosis (requiring amputation in one) and five local abscesses. Two became shocked and four developed renal failure. Three patients, aged 3, 11 and 65 years, died 18.75, 27.75 and 83 h after being bitten, with respiratory and circulatory failure despite large doses of specific antivenom and intensive-care- unit management. In two patients, autopsies revealed acute renal tubular necrosis, cerebral oedema, haemorrhagic rhabdomyolysis at the site of the bite and disseminated intravascular coagulation. In one survivor with chronic renal failure, renal biopsy showed bilateral cortical necrosis; the patient remains dependent on haemodialysis. Effects of polyspecific Bothrops antivenom were not impressive, and it has been suggested that anti-Bothrops and anti-Crotalus antivenoms should be given in combination.      

Vitamin C therapy ameliorates vascular endothelial dysfunction in treated patients with homocystinuria

Objectives: We sought to investigate the effects of short- and long-term vitamin C therapy on endothelial dysfunction in patients with homocystinuria. Background: Untreated homocystinuria due to cystathionine -synthase deficiency is associated with premature atherothrombotic disease; 25% of untreated patients suffer a vascular event by the age of 16 years and 50% by 29 years. Treatment directed at reducing homocysteine accumulation significantly reduces this risk. However, despite optimal treatment and compliance, hyperhomocysteinaemia usually persists and individuals exhibit endothelial dysfunction indicative of an adverse cardiovascular prognosis. Additional intervention is therefore required to further reduce cardiovascular risk. Methods: We investigated the endothelial effects of acute (2 g single dose) and chronic (1 g/day for 6 months) administration of oral vitamin C in 5 patients with homocystinuria (mean age 26 years, 1 male) and 5 age- and sex-matched controls. Brachial artery endothelium-dependent flow-mediated dilatation (FMD) and endothelium-independent responses to nitroglycerin (NTG) were measured using high-resolution ultrasonic vessel wall-tracking. Results: Baseline: Plasma total homocysteine was 100.8 ± 61.6 and 9.2 ± 1.9 mol/L in the patient and control groups, respectively (p < 0.001). FMD responses were impaired in the patient group (20 ± 40 m) compared with the controls (116 ± 30 m) (p < 0.001). Vitamin C administration: FMD responses in the patient group improved both acutely, 160 ± 65 m at 4 h (p < 0.001), and chronically, 170 ± 70 m at 2 weeks (p < 0.001) and 170 ± 40 m at 6 months (p < 0.001). FMD responses in the control group were unaltered (p = 0.526). Within both groups, neither the vascular response to NTG nor plasma homocysteine was altered (p > 0.4). Conclusions: Vitamin C ameliorates endothelial dysfunction in patients with homocystinuria, independent of changes in homocysteine concentration and should therefore be considered as an additional adjunct to therapy to reduce the potential long-term risk of atherothrombotic disease.     

Qualitative urinary organic acid analysis: Methodological approaches and performance

Summary  A programme for proficiency testing of biochemical genetics laboratories undertaking urinary qualitative organic acid analysis and its results for 50 samples examined for factors contributing to poor performance are described. Urine samples from patients in whom inherited metabolic disorders have been confirmed as well as control urines were circulated to participants and the results from 94 laboratories were evaluated. Laboratories showed variability both in terms of their individual performance and on a disease-specific basis. In general, conditions including methylmalonic aciduria, propionic aciduria, isovaleric aciduria, mevalonic aciduria, Canavan disease and 3-methylcrotonyl-CoA carboxylase were readily identified. Detection was poorer for other diseases such as glutaric aciduria type II, glyceric aciduria and, in one sample, 3-methylcrotonyl-CoA carboxylase deficiency. To identify the factors that allow some laboratories to perform well on a consistent basis while others perform badly, we devised a questionnaire and compared the responses with the results for performance in the scheme. A trend towards better performance could be demonstrated for those laboratories that regularly use internal quality control (QC) samples in their sample preparation (p = 0.079) and those that participate in further external quality assurance (EQA) schemes (p = 0,040). Clinicians who depend upon these diagnostic services to identify patients with these defects and the laboratories that provide them should be aware of the potential for missed diagnoses and the factors that may lead to improved performance. Electronic supplementary material  The online version of this article (doi: ) contains supplementary material, which is available to authorized users. Competing interests: None declared     

Translating Dental Flossing Intentions into Behavior: a Longitudinal Investigation of the Mediating Effect of Planning and Self-Efficacy on Young Adults

Purpose

Although poor oral hygiene practices can have serious health consequences, a large number of adults brush or floss their teeth less than the recommended time or not at all. This study examined the mediating effect of two key self-regulatory processes, self-efficacy and planning, as the mechanisms that translate dental flossing intentions into behavior.

Method

Participants (N = 629) comprised young adults attending a major university in Queensland, Australia. A longitudinal design guided by sound theory was adopted to investigate the sequential mediation chain for the effect of dental flossing intentions (time 1) on behavior (time 3) via self-efficacy and planning (time 2).

Results

A latent variable structural equation model with standardized parameter estimates revealed the model was a good fit to the data. Controlling for baseline flossing, the effect of intentions on behavior was mediated via self-efficacy and planning, with 64 % of the flossing variance accounted for by this set of predictors. Controlling for age and sex did not change the results.

Conclusion

The results extend previous research to further elucidate the mechanisms that help to translate oral hygiene intentions into behavior and make a significant contribution to the cumulative empirical evidence about self-regulatory components in health behavior change.

     

Advocacy and actions to address disparities in access to genomic health care: A report on a National Academies workshop

BackgroundIn the United States, access to genomic risk assessment, testing, and follow up care is most easily obtained by those who have sufficient financial, educational, and social resources. Multiple barriers limit the ability of populations without those resources to benefit from health care that integrates genomics in assessment of disease risk, diagnosis, and targeted treatment.PurposeTo summarize barriers and potential actions to reduce genomic health care disparities.MethodSummarize authors' views on discussions at a workshop hosted by the National Academy of Medicine.DiscussionBarriers include access to health care providers that utilize genomics, genetic literacy of providers and patients, and absence of evidence of gene variants importance in ancestrally diverse underserved populations.ConclusionEngagement between underserved communities, health care providers, and policy makers is an essential component to raise awareness and seek solutions to barriers in access to genomic health care for all populations.