Comparative study between the Light Cycler and the PCR-restriction fragment length polymorphism in detecting factor V Leiden and factor II 20210G>A mutations

OBJECTIVES: To test reproducibility, speed and cost of testing for factor V Leiden and FII 20210G>A in our practice. DESIGN AND METHODS: We compared conformity, reproducibility, speed and cost using the Light Cycler (LC) and PCR-RFLP. RESULTS: There was 100% conformity and reproducibility. LC was faster but 23% more expensive per sample. When equipment depreciation and patient expenses are added, LC testing becomes cheaper. CONCLUSION: In our practice, LC provides fast, reproducible and cost-effective results.     

Soil-transmitted helminthiasis in rural south-west China: prevalence, intensity and risk factor analysis

Only few studies in rural China have explored the epidemiology of intestinal helminth infections and identified risk factors for transmission. The study was carried out in Simao and Mengla counties, where single fecal samples were collected from 317 school-aged children and from 94 inhabitants of a single village. Fecal specimens were examined with the Kato-Katz thick smear method and examined for helminth eggs. Data regarding socio-demographic and behavioral risk factors were collected using questionnaires. In Simao County the overall soil-transmitted helminthes (STH) prevalence was 40.2% (2.7, 5.4 and 35.7% for ascariasis, trichuriasis and hookworm infection, respectively). The STH infection rates were significantly higher in Mengla County, with an overall prevalence of 68.3% (19.0, 34.6 and 47.3% for ascariasis, trichuriasis and hookworm infection, respectively). Females were less likely to be infected with Trichuris trichiura (OR 0.29; 95% CI 0.15-0.56) and with hookworms (OR 0.55; 95% CI 0.33-0.93) than males. Hookworm infections were more prevalent among those 12 years of age or older (OR 2.9; 95% CI 1.2-7.1). Children of mothers with educational attainment of secondary school or higher had a protective effect against T. trichiura (OR 0.18; 95% CI 0.06-0.54) and hookworm (OR 0.21; 95% CI 0.09-0.51) infections. In the village survey, hookworm was the most prevalent species (62.8%) with infection seen in those 50 years of age and older. Based on recommended intervention strategies by the World Health Organization, Simao County should opt for school-based deworming once each year, while Mengla County should implement a similar strategy biannually, but should include the elderly population.     

μ-Conotoxins that differentially block sodium channels NaV1.1 through 1.8 identify those responsible for action potentials in sciatic nerve

Voltage-gated sodium channels (VGSCs) are important for action potentials. There are seven major isoforms of the pore-forming and gate-bearing α-subunit (Na(V)1) of VGSCs in mammalian neurons, and a given neuron can express more than one isoform. Five of the neuronal isoforms, Na(V)1.1, 1.2, 1.3, 1.6, and 1.7, are exquisitely sensitive to tetrodotoxin (TTX), and a functional differentiation of these presents a serious challenge. Here, we examined a panel of 11 μ-conopeptides for their ability to block rodent Na(V)1.1 through 1.8 expressed in Xenopus oocytes. Although none blocked Na(V)1.8, a TTX-resistant isoform, the resulting "activity matrix" revealed that the panel could readily discriminate between the members of all pair-wise combinations of the tested isoforms. To examine the identities of endogenous VGSCs, a subset of the panel was tested on A- and C-compound action potentials recorded from isolated preparations of rat sciatic nerve. The results show that the major subtypes in the corresponding A- and C-fibers were Na(V)1.6 and 1.7, respectively. Ruled out as major players in both fiber types were Na(V)1.1, 1.2, and 1.3. These results are consistent with immunohistochemical findings of others. To our awareness this is the first report describing a qualitative pharmacological survey of TTX-sensitive Na(V)1 isoforms responsible for propagating action potentials in peripheral nerve. The panel of μ-conopeptides should be useful in identifying the functional contributions of Na(V)1 isoforms in other preparations.     

Volumetric reductions in the subgenual anterior cingulate cortex in adolescents with bipolar I disorder

Singh MK, Chang KD, Chen MC, Kelley RG, Garrett A, Mitsunaga MM, Bararpour L, Howe M, Reiss AL, Gotlib IH. Volumetric reductions in the subgenual anterior cingulate cortex in adolescents with bipolar I disorder.
Bipolar Disord 2012: 14: 585–596. © 2012 The Authors.
Journal compilation © 2012 John Wiley & Sons A/S. Objectives: A range of prefrontal and subcortical volumetric abnormalities have been found in adults and adolescents with bipolar disorder. It is unclear, however, if these deficits are present early in the onset of mania or are a consequence of multiple mood episodes or prolonged exposure to medication. The goal of this study was to examine whether youth with bipolar I disorder who recently experienced their first episode of mania are characterized by brain volumetric abnormalities. Methods: Anatomical images from magnetic resonance imaging of 26 13‐ to 18‐year‐old adolescents with bipolar I disorder and 24 age‐comparable healthy controls with no personal or family history of psychopathology were analyzed using whole‐brain voxel‐based morphometry (VBM). Results: Compared with healthy controls, adolescents with bipolar I disorder had significantly less gray matter volume in the left subgenual cingulate cortex [p < 0.05, family‐wise error (FWE)‐corrected]. Conclusions: Adolescents with a recent single episode of mania have smaller subgenual cingulate cortex volume than do their healthy counterparts, suggesting that this anomaly occurs early in the onset of, or may predate the disorder. Longitudinal studies are needed to examine the impact of this volumetric reduction on the course and outcome of this disorder.