Preliminary Findings on the Effects of Occupational Exposure to Mercury Vapor Below Safety Levels on Visual and Neuropsychological Functions

Objective: To evaluate whether there are visual and neurophysical decrements in workers with low exposure to Hg vapor. Methods: Visual fields, contrast sensitivity, color vision, and neuropsychological functions were measured in 10 workers (32.5 +/- 8.5 years) chronically exposed to Hg vapor (4.3 +/- 2.8 years; urinary Hg concentration 22.3 +/- 9.3 mu g/g creatinine). Results: For the worst eyes, we found altered visual field thresholds, lower contrast sensitivity, and color discrimination compared with controls (P < 0.05). There were no significant differences between Hg-exposed subjects and controls on. neuropsychological tests. Nevertheless, duration of exposure was statistically correlated to verbal memory and depression scores. Conclusions: Chronic exposure to Hg vapor at currently accepted safety levels was found to be associated with visual losses but not with neuropsychological dysfunctions in the sample of workers studied. (J Occup Environ Med. 2009,51:1403-1412)

INFLAMMATORY RESPONSE AND NEUTROPHIL FUNCTIONS IN PLAYERS AFTER A FUTSAL MATCH

de Moura, NR, Cury-Boaventura, MF, Santos, VC, Levada-Pires, AC, Bortolon, JR, Fiamoncini, J, Pithon-Curi, TC, Curi, R, and Hatanaka, E. Inflammatory response and neutrophil functions in players after a futsal match. J Strength Cond Res 26(9): 2507-2514, 2012-Futsal players suffer injuries resulting from muscle fatigue and contact or collision among players. Muscle lesions can be detected by measuring muscle lesion markers such as creatine kinase (CK) and lactate dehydrogenase (LDH) in plasma. After an initial lesion, there is an increase in the plasma levels of C-reactive protein (CRP) and proinflammatory cytokines. These mediators may activate neutrophils and contribute to tissue damage and increase susceptibility to invasive microorganisms. In this study, we investigated the effect of a futsal match on muscle lesion markers, cytokines, and CRP in elite players. The basal and stimulated neutrophil responsiveness after a match was also evaluated based on measurements of neutrophil necrosis, apoptosis, phagocytic capacity, reactive oxygen species (ROS) production, and cytokines (tumor necrosis factor-alpha [TNF-alpha], interleukin [IL]-8, IL-1 beta, IL-10, and IL-1ra) production. Blood samples were taken from 16 players (26.4 +/- 3.2 years, 70.2 +/- 6.9 kg, 59.7 +/- 5.1 ml.kg(-1).min(-1), sports experience of 4.4 +/- 0.9 years) before and immediately after a match. Exercise increased the serum activities of CK (2.5-fold) and LDH (1.3-fold). Playing futsal also increased the serum concentrations of IL-6 (1.6-fold) and CRP (1.6-fold). The TNF-alpha, IL-1 beta, IL-8, IL-1ra, and IL-10 serum levels were not modified in the conditions studied. The futsal match induced neutrophil apoptosis, as indicated by phosphatidylserine externalization (6.0-fold). The exercise induced priming of neutrophils by increasing ROS (1.3-fold), TNF-alpha (5.8-fold), and IL-1 beta (4.8-fold) released in nonstimulated cells. However, in the stimulated condition, the exercise decreased neutrophil function, diminishing the release of ROS by phorbol myristate acetate-stimulated neutrophils (1.5-fold), and the phagocytic capacity (1.6-fold). We concluded that playing futsal induces inflammation, primes and activates neutrophils, and reduces the efficiency of neutrophil phagocytosis immediately after a match.

Benthic foraminiferal distribution on the southeastern Brazilian shelf and upper slope

Foraminiferal data were obtained from 66 samples of box cores on the southeastern Brazilian upper margin (between 23.8A degrees-25.9A degrees S and 42.8A degrees-46.13A degrees W) to evaluate the benthic foraminiferal fauna distribution and its relation to some selected abiotic parameters. We focused on areas with different primary production regimes on the southern Brazilian margin, which is generally considered as an oligotrophic region. The total density (D), richness (R), mean diversity (H) over bar`, average living depth (ALD(X) ) and percentages of specimens of different microhabitats (epifauna, shallow infauna, intermediate infauna and deep infauna) were analyzed. The dominant species identified were Uvigerina spp., Globocassidulina subglobosa, Bulimina marginata, Adercotryma wrighti, Islandiella norcrossi, Rhizammina spp. and Brizalina sp.. We also established a set of mathematical functions for analyzing the vertical foraminiferal distribution patterns, providing a quantitative tool that allows correlating the microfaunal density distributions with abiotic factors. In general, the cores that fit with pure exponential decaying functions were related to the oligotrophic conditions prevalent on the Brazilian margin and to the flow of the Brazilian Current (BC). Different foraminiferal responses were identified in cores located in higher productivity zones, such as the northern and the southern region of the study area, where high percentages of infauna were encountered in these cores, and the functions used to fit these profiles differ appreciably from a pure exponential function, as a response of the significant living fauna in deeper layers of the sediment. One of the main factors supporting the different foraminiferal assemblage responses may be related to the differences in primary productivity of the water column and, consequently, in the estimated carbon flux to the sea floor. Nevertheless, also bottom water velocities, substrate type and water depth need to be considered.

Tropidomyrmex elianae, a new myrmicine ant genus and species from Brazil, tentatively assigned to Solenopsidini (Hymenoptera, Formicidae)

A new myrmicine ant, Tropidomyrmex elianae gen. n. & sp. n., is described from southeastern and central Brazil, based on workers, ergatoid gynes, males and larvae. Tropidomyrmex workers are relatively small, monomorphic, characterized mainly by the feebly pigmented and extremely thin integument; subfalcate mandibles bearing a single apical tooth; palpal formula 1,2; clypeus relatively broad and convex; reduced compound eyes; propodeum unarmed and with a strongly medially depressed declivous face; double and bilobed well developed subpostpetiolar processes; and peculiarities in the sting apparatus. A colony fragment of T. elianae containing workers, ergatoid gynes, males, and brood was found inside a ground termite nest (Anoplotermes pacificus Apicotermitinae) in a montane rocky scrubland in the state of Minas Gerais, southeastern Brazil. Tropidomyrmex elianae is known also from two workers collected in leaf litter samples processed with a Winkler extractor, from the state of Tocantins, central-north Brazil. Despite the differences from the accepted solenopsidine genera, Tropidomyrmex is tentatively assigned to this tribe. Within the solenopsidine ants, the genus is apparently related to Tranopelta. Tropidomyrmex is marked by extreme reductions, perhaps reflecting adaptations to particular habits and habitats.

Bivariate gamma-geometric law and its induced Levy process

In this article we introduce a three-parameter extension of the bivariate exponential-geometric (BEG) law (Kozubowski and Panorska, 2005) [4]. We refer to this new distribution as the bivariate gamma-geometric (BGG) law. A bivariate random vector (X, N) follows the BGG law if N has geometric distribution and X may be represented (in law) as a sum of N independent and identically distributed gamma variables, where these variables are independent of N. Statistical properties such as moment generation and characteristic functions, moments and a variance-covariance matrix are provided. The marginal and conditional laws are also studied. We show that BBG distribution is infinitely divisible, just as the BEG model is. Further, we provide alternative representations for the BGG distribution and show that it enjoys a geometric stability property. Maximum likelihood estimation and inference are discussed and a reparametrization is proposed in order to obtain orthogonality of the parameters. We present an application to a real data set where our model provides a better fit than the BEG model. Our bivariate distribution induces a bivariate Levy process with correlated gamma and negative binomial processes, which extends the bivariate Levy motion proposed by Kozubowski et al. (2008) [6]. The marginals of our Levy motion are a mixture of gamma and negative binomial processes and we named it BMixGNB motion. Basic properties such as stochastic self-similarity and the covariance matrix of the process are presented. The bivariate distribution at fixed time of our BMixGNB process is also studied and some results are derived, including a discussion about maximum likelihood estimation and inference. (C) 2012 Elsevier Inc. All rights reserved.

Structural and Functional Insights from the Metagenome of an Acidic Hot Spring Microbial Planktonic Community in the Colombian Andes

A taxonomic and annotated functional description of microbial life was deduced from 53 Mb of metagenomic sequence retrieved from a planktonic fraction of the Neotropical high Andean (3,973 meters above sea level) acidic hot spring El Coquito (EC). A classification of unassembled metagenomic reads using different databases showed a high proportion of Gammaproteobacteria and Alphaproteobacteria (in total read affiliation), and through taxonomic affiliation of 16S rRNA gene fragments we observed the presence of Proteobacteria, micro-algae chloroplast and Firmicutes. Reads mapped against the genomes Acidiphilium cryptum JF-5, Legionella pneumophila str. Corby and Acidithiobacillus caldus revealed the presence of transposase-like sequences, potentially involved in horizontal gene transfer. Functional annotation and hierarchical comparison with different datasets obtained by pyrosequencing in different ecosystems showed that the microbial community also contained extensive DNA repair systems, possibly to cope with ultraviolet radiation at such high altitudes. Analysis of genes involved in the nitrogen cycle indicated the presence of dissimilatory nitrate reduction to N2 (narGHI, nirS, norBCDQ and nosZ), associated with Proteobacteria-like sequences. Genes involved in the sulfur cycle (cysDN, cysNC and aprA) indicated adenylsulfate and sulfite production that were affiliated to several bacterial species. In summary, metagenomic sequence data provided insight regarding the structure and possible functions of this hot spring microbial community, describing some groups potentially involved in the nitrogen and sulfur cycling in this environment. Citation: Jimenez DJ, Andreote FD, Chaves D, Montana JS, Osorio-Forero C, et al. (2012) Structural and Functional Insights from the Metagenome of an Acidic Hot Spring Microbial Planktonic Community in the Colombian Andes. PLoS ONE 7(12): e52069. doi:10.1371/journal.pone.0052069

Effective carrying capacity and analytical solution of a particular case of the Richards-like two-species population dynamics model

We consider a generalized two-species population dynamic model and analytically solve it for the amensalism and commensalism ecological interactions. These two-species models can be simplified to a one-species model with a time dependent extrinsic growth factor. With a one-species model with an effective carrying capacity one is able to retrieve the steady state solutions of the previous one-species model. The equivalence obtained between the effective carrying capacity and the extrinsic growth factor is complete only for a particular case, the Gompertz model. Here we unveil important aspects of sigmoid growth curves, which are relevant to growth processes and population dynamics. (C) 2011 Elsevier B.V. All rights reserved.

On the Hilbert transform in the framework of generalized functions

In this paper, a definition of the Hilbert transform operating on Colombeau's temperated generalized functions is given. Similar results to some theorems that hold in the classical theory, or in certain subspaces of Schwartz distributions, have been obtained in this framework.

Exercise Performance and Dynamic Hyperinflation in Lymphangioleiomyomatosis

Rationale: Lymphangioleiomyomatosis (LAM) is characterized by exercise performance impairment. Although airflow limitation is common, no previous studies have evaluated the prevalence and impact of dynamic hyperinflation (DH) in LAM. Objectives: To investigate the dynamic responses during maximal exercise and the prevalence, predictors, and repercussions of DH in LAM. Methods: Forty-two patients with LAM performed symptom-limited incremental cycle exercise and pulmonary functions tests (PFTs) and were compared with 10 age-matched healthy women. Dyspnea intensity, inspiratory capacity, oxygen saturation, and cardiac, metabolic, and respiratory variables were assessed during exercise. Patients with LAM also performed a 6-minute walk test (6MWT). Measurements and Main Results: Patients with LAM had higher baseline dyspnea, poorer quality of life, obstructive pattern, air trapping, and reduced diffusing capacity of carbon monoxide in PFTs. Although they had the same level of regular physical activity, their maximal exercise performance was reduced and was associated with ventilatory limitation, greater desaturation, and dyspnea. The prevalence of DH was high in LAM (55%), even in patients with mild spirometric abnormalities, and was correlated with airflow obstruction, air trapping, and diffusing capacity of carbon monoxide. Compared with the non-DH subgroup, the patients who developed DH had a ventilatory limitation contributing to exercise cessation on cycling and higher desaturation and dyspnea intensity during the 6MWT. Conclusions: Ventilatory limitation and gas exchange impairment are important causes of exercise limitation in LAM. DH is frequent in LAM, even in patients with mild spirometric abnormalities. DH was associated with the severity of disease, higher dyspnea, and lower oxygen saturation. In the 6MWT, desaturation and dyspnea were greater in patients with DH.

The McDonald extended distribution: properties and applications

We study a five-parameter lifetime distribution called the McDonald extended exponential model to generalize the exponential, generalized exponential, Kumaraswamy exponential and beta exponential distributions, among others. We obtain explicit expressions for the moments and incomplete moments, quantile and generating functions, mean deviations, Bonferroni and Lorenz curves and Gini concentration index. The method of maximum likelihood and a Bayesian procedure are adopted for estimating the model parameters. The applicability of the new model is illustrated by means of a real data set.

Juvenile myoclonic epilepsy: The impact of clinical variables and psychiatric disorders on executive profile assessed with a comprehensive neuropsychological battery

Executive dysfunction is reported in juvenile myoclonic epilepsy (JME). However, batteries employed in previous studies included no more than three tests of executive function. In this study, we aimed to assess executive and attentional functions in JME using a comprehensive battery of eight tests (encompassing fifteen subtests). We also evaluated neuropsychological profiles using a clinical criterion of severity and correlated these findings with epilepsy clinical variables and the presence of psychiatric disorders. We prospectively evaluated 42 patients with JME and a matched control group with Digit Span tests (forward and backward), Stroop Color-Word Test, Trail Making Test, Wisconsin Card-Sorting Test, Matching Familiar Figures Test and Word Fluency Test. We estimated IQ with the Matrix Reasoning and Vocabulary subtests of the Wechsler Abbreviated Intelligence Scale. The patients with JME showed specific deficits in working memory, inhibitory control, concept formation, goal maintenance, mental flexibility, and verbal fluency. We observed attentional deficits in processes such as alertness and attention span and those requiring sustained and divided attention. We found that 83.33% of the patients had moderate or severe executive dysfunction. In addition, attentional and executive impairment was correlated with higher frequency of seizures and the presence of psychiatric disorders. Furthermore, executive dysfunction correlated with a longer duration of epilepsy. Our findings indicate the need for comprehensive neuropsychological batteries in patients with JME, in order to provide a more extensive evaluation of attentional and executive functions and to show that some relevant deficits have been overlooked. (C) 2012 Elsevier Inc. All rights reserved.

Altered Glucose Homeostasis and Hepatic Function in Obese Mice Deficient for Both Kinin Receptor Genes

The Kallikrein-Kinin System (KKS) has been implicated in several aspects of metabolism, including the regulation of glucose homeostasis and adiposity. Kinins and des-Arg-kinins are the major effectors of this system and promote their effects by binding to two different receptors, the kinin B2 and B1 receptors, respectively. To understand the influence of the KKS on the pathophysiology of obesity and type 2 diabetes (T2DM), we generated an animal model deficient for both kinin receptor genes and leptin (obB1B2KO). Six-month-old obB1B2KO mice showed increased blood glucose levels. Isolated islets of the transgenic animals were more responsive to glucose stimulation releasing greater amounts of insulin, mainly in 3-month-old mice, which was corroborated by elevated serum C-peptide concentrations. Furthermore, they presented hepatomegaly, pronounced steatosis, and increased levels of circulating transaminases. This mouse also demonstrated exacerbated gluconeogenesis during the pyruvate challenge test. The hepatic abnormalities were accompanied by changes in the gene expression of factors linked to glucose and lipid metabolisms in the liver. Thus, we conclude that kinin receptors are important for modulation of insulin secretion and for the preservation of normal glucose levels and hepatic functions in obese mice, suggesting a protective role of the KKS regarding complications associated with obesity and T2DM.

Low-dose Enalapril Reduces Angiotensin II and Attenuates Diabetic-induced Cardiac and Autonomic Dysfunctions

Activation of renin-angiotensin system has been linked to cardiovascular and autonomic dysfunctions in diabetes. Experiments were performed to investigate the effects of angiotensin-converting enzyme inhibitor (ACEI), enalapril, on cardiac and autonomic functions in diabetic rats. Diabetes was induced by streptozotocin (50 mg/kg), and rats were treated with enalapril (1 mg.kg(-1).d(-1)). After 30 days, evaluations were performed in control, diabetic, and enalapril-treated groups. Cardiac function was evaluated by echocardiography and through cannulation of the left ventricle (at baseline and in response to volume overload). Heart rate and systolic blood pressure variabilities were evaluated in the time and frequency domains. Streptozotocin rats had left ventricular systolic and diastolic dysfunctions, expressed by reduced ejection fraction and increased isovolumic relaxation time. The ACEI prevented these changes, improved diastolic cardiac responses to volume overload and total power of heart rate variability, reduced the ACE1 activity and protein expression and cardiac angiotensin (Ang) II levels, and increased angiotensin-converting enzyme 2 activity, despite unchanged blood pressure. Correlations were obtained between Ang II content with systolic and diastolic functions and heart rate variability. These findings provide evidence that the low-dose ACEI prevents autonomic and cardiac dysfunctions induced by diabetes without changing blood pressure and associated with reduced cardiac Ang II and increased angiotensin-converting enzyme 2 activity.

Leptin as a link between the immune system and kidney-related diseases: leading actor or just a coadjuvant?

Food intake and nutritional status modify the physiological responses of the immune system to illness and infection and regulate the development of chronic inflammatory processes, such as kidney disease. Adipose tissue secretes immune-related proteins called adipokines that have pleiotropic effects on both the immune and neuroendocrine systems, linking metabolism and immune physiology. Leptin, an adipose tissue-derived adipokine, displays a variety of immune and physiological functions, and participates in several immune responses. Here, we review the current literature on the role of leptin in kidney diseases, linking adipose tissue and the immune system with kidney-related disorders. The modulation of this adipose hormone may have a major impact on the treatment of several immune- and metabolic-related kidney diseases.

Longitudinal familial analysis of blood pressure involving parametric (co)variance functions

Abstract Background For analyzing longitudinal familial data we adopted a log-linear form to incorporate heterogeneity in genetic variance components over the time, and additionally a serial correlation term in the genetic effects at different levels of ages. Due to the availability of multiple measures on the same individual, we permitted environmental correlations that may change across time. Results Systolic blood pressure from family members from the first and second cohort was used in the current analysis. Measures of subjects receiving hypertension treatment were set as censored values and they were corrected. An initial check of the variance and covariance functions proposed for analyzing longitudinal familial data, using empirical semi-variogram plots, indicated that the observed trait dispersion pattern follows the assumptions adopted. Conclusion The corrections for censored phenotypes based on ordinary linear models may be an appropriate simple model to correct the data, ensuring that the original variability in the data was retained. In addition, empirical semi-variogram plots are useful for diagnosis of the (co)variance model adopted.