Onychomycosis in São Paulo,Brazil

Onychomycosis is a fungal infection of the nails with broad aetiological scope, and it represents 18–40% of all onychopathies and 39% of all superficial mycotic infections. From July 1996 to December 1999, samples of nails were collected from 588 patients with presumptive diagnosis of onychomycosis at the Dermatology and Mycology Divisions EPM\UNIFESP, Brazil, and the diagnosis was confirmed in 247 of these cases. The most common pathogens isolated in this study were yeasts in 52% of positive cultures (Candida albicans 18.3%, Candida parapsilosis 13.8%, other species of Candida 15.4% and other yeasts 4.6%), followed by dermatophytes in 40.6% of positive cultures (the most commonly isolated organisms were Trichophyton rubrum in 33.2%, followed by Trichophyton mentagrophytes in 6.3% and others 1.2%). Non-dermatophyte moulds were isolated in 7.4% of positive cultures (Fusarium spp. 4.5%, Nattrassia mangiferae 2.3% and Aspergillus spp. 0.6%). Distal and lateral subungual onychomycosis (DLSO) was the commonest clinical pattern 44.6% followed by free edge onycholysis (FEO) 38.8% and others. In conclusion, this study demonstrated that T. rubrum is the main agent causing onychomycosis in toenails, and species of genus Candida were the main agents isolated in fingernail onychomycosis in our region.     

Insights of the life history in the porcellanid crab Petrolisthes armatus (Gibbes, 1850) (Crustacea: Anomura: Porcellanidae) from the Southwestern Atlantic coast

Petrolisthes armatus (Gibbes, 1850) life history was evaluated based on growth and reproduction. Specimens were captured at Ubatuba (Brazil), identified, sexed and measured: carapace (CL, length; CW, width), larger cheliped propodus (PL, length; PW, width; and PH, height), and 2th and 5th abdominal somite (AW₂ and AW₅, width). Relative growth was studied using CL as independent variable and its relation with other variables (dependents), to estimate puberty size and morphological maturity. Fecundity was represented by number of eggs vs. body size CL, with a better fit using a power function. Considering the 257 specimens analyzed, males were larger than females, and the overall sex ratio was 1:1, with some differences among size classes. Maturity (puberty size) was revealed by: AW₂ × CL (males: 8.6 mm CL; females: 7.6 mm CL); and AW₅ × CL (7.1 and 7.6 mm CL, respectively). Reproduction was continuous, but more intense in rainy season and recruitment occurring in dry season. Fecundity of this species was 228 ± 163 eggs, with better fit by a power function (R² = 0.72). Maturity size and growth differed when a pristine area (Ubatuba) was compared with a polluted area (São Sebastião), in the same Brazilian area (São Paulo State).     

Characterization of phylogenetic networks with NetTest

Background  

Typical evolutionary events like recombination, hybridization or gene transfer make necessary the use of phylogenetic networks to properly depict the evolution of DNA and protein sequences. Although several theoretical classes have been proposed to characterize these networks, they make stringent assumptions that will likely not be met by the evolutionary process. We have recently shown that the complexity of simulated networks is a function of the population recombination rate, and that at moderate and large recombination rates the resulting networks cannot be categorized. However, we do not know whether these results extend to networks estimated from real data.     

Genetic diversity of pioneer populations: the case of <Emphasis Type="Italic">Nassauvia argentea</Emphasis> (Asteraceae: Mutisieae) on Volcán Lonquimay,Chile

Colonising populations do not always exhibit founder effects. Common explanations are high levels of immigration and/or reproduction, but few empirical tests have been done. We measured genetic diversity of Nassauvia argentea in terms of variation and divergence of plant populations that have colonised Volcán Lonquimay, Chile, following its latest eruption in 1988. Fifteen individuals from each of ten populations were analysed using amplified fragment length polymorphism (AFLP) markers. Genetic variation and divergence were lower in colonising populations than established ones, but not significantly so (ANOVA and Kruskal-Wallis tests, p < 0.05). No consistent or significant trends were obtained from regressions with demographic variables. Bayesian analysis of population structure reveals close relatedness among populations of all ages on the volcano. We concluded that no conspicuous founder effect has occurred in the genetic diversity of populations colonising a newly derived volcanic environment. An important implication of this is the role of proximity to source regions and species vigour in moulding genetic diversity of colonisers from different species.     

DNA polymerase gamma mutations that impair holoenzyme stability cause catalytic subunit depletion

Mutations in POLG, encoding POLγA, the catalytic subunit of the mitochondrial DNA polymerase, cause a spectrum of disorders characterized by mtDNA instability. However, the molecular pathogenesis of POLG-related diseases is poorly understood and efficient treatments are missing. Here, we generate the Polg^A449T/A449T mouse model, which reproduces the A467T change, the most common human recessive mutation of POLG. We show that the mouse A449T mutation impairs DNA binding and mtDNA synthesis activities of POLγ, leading to a stalling phenotype. Most importantly, the A449T mutation also strongly impairs interactions with POLγB, the accessory subunit of the POLγ holoenzyme. This allows the free POLγA to become a substrate for LONP1 protease degradation, leading to dramatically reduced levels of POLγA in A449T mouse tissues. Therefore, in addition to its role as a processivity factor, POLγB acts to stabilize POLγA and to prevent LONP1-dependent degradation. Notably, we validated this mechanism for other disease-associated mutations affecting the interaction between the two POLγ subunits. We suggest that targeting POLγA turnover can be exploited as a target for the development of future therapies.     

An integrate-and-fire model to generate spike trains with long-range dependence

Long-range dependence (LRD) has been observed in a variety of phenomena in nature, and for several years also in the spiking activity of neurons. Often, this is interpreted as originating from a non-Markovian system. Here we show that a purely Markovian integrate-and-fire (IF) model, with a noisy slow adaptation term, can generate interspike intervals (ISIs) that appear as having LRD. However a proper analysis shows that this is not the case asymptotically. For comparison, we also consider a new model of individual IF neuron with fractional (non-Markovian) noise. The correlations of its spike trains are studied and proven to have LRD, unlike classical IF models. On the other hand, to correctly measure long-range dependence, it is usually necessary to know if the data are stationary. Thus, a methodology to evaluate stationarity of the ISIs is presented and applied to the various IF models. We explain that Markovian IF models may seem to have LRD because of non-stationarities.     

46,XX ovotesticular disorder in a Mexican patient with Beckwith--Wiedemann syndrome: a case report

ABSTRACT: INTRODUCTION: Beckwith--Wiedemann syndrome is an overgrowth syndrome that is characterized by hypoglycemia at birth, coarse face, hemihypertrophy and an increased risk to develop embryonal tumors. In approximately 15% of patients, the inheritance is autosomal dominant with variable expressivity and incomplete penetrance, whereas the remainder of Beckwith--Wiedemann syndrome cases are sporadic. Beckwith--Wiedemann syndrome molecular etiologies are complex and involve the two imprinting centers 1 (IC1) and 2 (IC2) of 11p15 region. This case report describes, for the first time, the unusual association of ovotesticular disorder in a patient from Morelia, Mexico with Wiedemann-Beckwith syndrome. CASE PRESENTATION: We report the case of a Mexican six-year-old girl with Beckwith--Wiedemann Syndrome, ambiguous genitalia, and bilateral ovotestes. She has a 46,XX karyotype without evidence of Y-chromosome sequences detected by fluorescence in situ hybridization with both SRY and wcp-Y probes. CONCLUSION: Although a random association between these two conditions cannot be excluded, future analysis of this patient with Beckwith--Wiedemann syndrome and 46,XX ovotesticular disorder may lead to new insights into these complex pathologies. We speculate that a possible misregulation in the imprinted genes network has a fundamental role in the coexistence of these two disorders.     

A randomized, double blind, cross-over, placebo-controlled clinical trial to assess the effects of Candesartan on the insulin sensitivity on non diabetic, non hypertense subjects with dysglyce mia and abdominal obesity. "ARAMIA"

In ageing men testosterone levels decline, while cognitive function, muscle and bone mass, sexual hair growth, libido and sexual activity decline and the risk of cardiovascular diseases increase. We set up a double-blind, randomized placebo-controlled trial to investigate the effects of testosterone supplementation on functional mobility, quality of life, body composition, cognitive function, vascular function and risk factors, and bone mineral density in older hypogonadal men. We recruited 237 men with serum testosterone levels below 13.7 nmol/L and ages 60–80 years. They were randomized to either four capsules of 40 mg testosterone undecanoate (TU) or placebo daily for 26 weeks. Primary endpoints are functional mobility and quality of life. Secondary endpoints are body composition, cognitive function, aortic stiffness and cardiovascular risk factors and bone mineral density. Effects on prostate, liver and hematological parameters will be studied with respect to safety. Measure of effect will be the difference in change from baseline visit to final visit between TU and placebo. We will study whether the effect of TU differs across subgroups of baseline waist girth (< 100 cm vs. ≥ 100 cm; testosterone level (<12 versus ≥ 12 nmol/L), age (< median versus ≥ median), and level of outcome under study (< median versus ≥ median). At baseline, mean age, BMI and testosterone levels were 67 years, 27 kg/m² and 10.72 nmol/L, respectively.