Serological Evidence of HTLV-I and HTLV-II Coinfections in HIV-1 Positive Patients in Belém, State of Pará, Brazil

The occurrence of HTLV-I/II and HIV-1 coinfections have been shown to be frequent, probably in consequence of their similar modes of transmission. This paper presents the prevalence of coinfection of HTLV among HIV-1 infected and AIDS patients in Belém, State of Pará, Brazil. A group of 149 patients attending the AIDS Reference Unit of the State Department of Health was tested for the presence of antibodies to HTLV-I/II using an enzyme immunoassay and the positive reactions were confirmed with a Western blot that discriminates between HTLV-I and HTLV-II infections. Four patients (2.7%) were positive to HTLV-I, seven (4.7%) to HTLV-II and one (0.7%) showed an indeterminate pattern of reaction. The present results show for the first time in Belém not only the occurrence of HTLV-II/HIV-1 coinfections but also a higher prevalence of HTLV-II in relation to HTLV-I. Furthermore, it also enlarges the geographical limits of the endemic area for HTLV-II in the Amazon region of Brazil.

The lack of effect of insulin on luteinizing hormone pulsatility in healthy male volunteers provides evidence of a sexual dimorphism in the metabolic regulation of reproductive hormones.

BACKGROUND: The activity of the neuroendocrine reproductive axis is closely related to nutritional status. This link is particularly important in healthy women, in whom insulin is a positive signal for the reproductive system. In contrast, very little is known regarding this relation in men. OBJECTIVES: This study was designed to evaluate the effect of insulin on the reproductive axis of young male volunteers and to study the effect of short-term hypercaloric feeding on this modulation. DESIGN: The activity of the neuroendocrine reproductive axis was characterized by the pattern of endogenous luteinizing hormone (LH) secretion on the basis of frequent blood sampling protocols. The effect of insulin was tested by comparing the LH secretion pattern between a baseline study and a hyperinsulinemic euglycemic clamp. These studies were performed first in subjects fed a controlled isocaloric diet for 6 d (calculated as 1.5 times their resting metabolic rate) then in the same subjects fed a controlled hypercaloric diet in which 30% extra calories were provided as fat and fructose (3 g · kg(-1) · d(-1)) before undergoing identical protocols. Serum gonadotropins, sex steroids, glucose, insulin, ghrelin, and leptin concentrations were assessed, and the HOMA-IR was calculated. RESULTS: The LH secretion pattern was not affected by insulin or by hypercaloric feeding. Insulin decreased ghrelin and increased leptin concentrations but had no additional effect of hypercaloric feeding despite significantly lower HOMA-IR indexes. CONCLUSIONS: Our data indicate that neither insulin nor short-term hypercaloric feeding has any effect on the activity of the male reproductive axis. They also further support the association between ghrelin and insulin and glucose metabolism. This trial was registered at clinicaltrials.gov as NCT01058681.

Hydrocarbon biomarkers in the Topla-Mezica zinc-lead deposits, northern Karavanke/Drau Range, Slovenia: Paleoenvironment at the site of ore formation

The Mississippi Valley-type zinc and lead deposits at Topla (250,150 metric tons (t) of ore grading 1.0 wt % Zn and 3.3 wt % Pb) and Mezica (19 million metric tons (Mt) of ore grading 5.3 wt % Pb and 2.7 wt % Zn) occur within the Middle to Upper Triassic platform carbonate rocks of the northern Karavanke/Drau Range geotectonic units of the Eastern Alps, Slovenia. The ore and host rocks of these deposits have been investigated by a combination of inorganic and organic geochemical methods to determine major, trace, and rare earth element (REE) concentrations, hydrocarbon distribution, and stable isotope ratios of carbonates, kerogen, extractable organic matter, and individual hydrocarbons. These data combined with sedimentological evidence provide insight into the paleoenvironmental conditions at the site of ore formation. The carbonate isotope composition, the REE patterns, and the distribution of hydrocarbon biomarkers (normal alkanes and steranes) suggest a marine depositional environment. At Topla, a relatively high concentration of redox sensitive trace elements (V, Mo, U) in the host dolostones and REE patterns parallel to that of the North American shale composite suggest that sediments were deposited in a reducing environment. Anoxic conditions enhanced the preservation of organic matter and resulted in relatively higher total organic carbon contents (up to 0.4 wt %). The isotopic composition of the kerogen (delta C-13(kerogon) = -29.4 to -25.0 parts per thousand, delta N-15(kerogen) = -.13.6 to 6.8 parts per thousand) suggests that marine algae and/or bacteria were the main source of organic carbon with a very minor contribution from detrital continental plants and a varying degree of alteration. Extractable organic matter from Topla ore is generally depleted in C-13 compared to the associated kerogen, which is consistent with an indigenous source of the bitumens. The mineralization correlates with delta N-15(kerogen) values around 0 per mil, C-13 depleted kerogen, C-13 enriched n-heptadecane, and relatively high concentrations of bacteria] hydrocarbon biomarkers, indicating a high cyanobacterial biomass at the site of ore formation. Abundant dissimilatory sulfate-reducing bacteria, feeding on the cyanobacterial remains, led to accumulation of biogenic H2S in the pore water of the sediments. This biogenic H2S was mainly incorporated into sedimentary organic matter and diagenetic pyrite. Higher bacterial activity at the ore site also is indicated by specific concentration ratios of hydrocarbons, which are roughly correlated with total Pb plus Zn contents. This correlation is consistent with mixing of hydrothermal metal-rich, fluids and local bacteriogenic sulfide sulfur. The new geochemical data provide supporting evidence that Topla is a low-temperature Mississippi Valley-type deposit formed in an anoxic supratidal saline to hypersaline environment. A laminated cyanobacterial mat, with abundant sulfate-reducing bacteria was the main site of sulfate reduction.

Inflammation-induced alteration of astrocyte mitochondrial dynamics requires autophagy for mitochondrial network maintenance.

Accumulating evidence suggests that changes in the metabolic signature of astrocytes underlie their response to neuroinflammation, but how proinflammatory stimuli induce these changes is poorly understood. By monitoring astrocytes following acute cortical injury, we identified a differential and region-specific remodeling of their mitochondrial network: while astrocytes within the penumbra of the lesion undergo mitochondrial elongation, those located in the core-the area invaded by proinflammatory cells-experience transient mitochondrial fragmentation. In brain slices, proinflammatory stimuli reproduced localized changes in mitochondrial dynamics, favoring fission over fusion. This effect was triggered by Drp1 phosphorylation and ultimately resulted in reduced respiratory capacity. Furthermore, maintenance of the mitochondrial architecture critically depended on the induction of autophagy. Deletion of Atg7, required for autophagosome formation, prevented the reestablishment of tubular mitochondria, leading to marked reactive oxygen species accumulation and cell death. Thus, our data reveal autophagy to be essential for regenerating astrocyte mitochondrial networks during inflammation.

Does grade retention affect achievement? Some evidence from PISA

Grade retention practices are at the forefront of the educational debate. In this paper, we use PISA 2009 data for Spain to measure the effect of grade retention on students’ achievement. One important problem when analyzing this question is that school outcomes and the propensity to repeat a grade are likely to be determined simultaneously. We address this problem by estimating a Switching Regression Model. We …find that grade retention has a negative impact on educational outcomes, but we confi…rm the importance of endogenous selection, which makes observed differences between repeaters and non-repeaters appear 14.6% lower than they actually are. The effect on PISA scores of repeating is much smaller (-10% of non-repeaters’ average) than the counterfactual reduction that non-repeaters would suffer had they been retained as repeaters (-24% of their average). Furthermore, those who repeated a grade during primary education suffered more than those who repeated a grade of secondary school, although the effect of repeating at both times is, as expected, much larger.

The social transition of risk factors for cardiovascular disease in the African region: evidence from three cross-sectional surveys in the Seychelles.

OBJECTIVES: To examine the association between socioeconomic status (SES) and several cardiovascular disease risk factors (CVRFs) and to assess whether this association has changed over a 15-year observation period. METHODS: Three independent population-based surveys of CVRFs were conducted in representative samples of all adults aged 25-64 years in the Seychelles, a small island state located east to Kenya, in 1989 (N=1081), 1994 (N=1067) and 2004 (N=1255). RESULTS: Among men, current smoking and heavy drinking were more prevalent in the low versus the high SES group, and obesity was less prevalent. The socioeconomic gradient in diabetes reversed over the study period from lower prevalence in the low versus the high SES group to higher prevalence in the low SES group. Hypercholesterolemia was less prevalent in the low versus the high SES group in 1989 but the prevalence was similar in the two groups in 2004. Hypertension showed no consistent socioeconomic pattern. Among women, the SES gradient in smoking tended to reverse over time from lower prevalence in the low SES group to lower prevalence in the high SES group. Obesity and diabetes were more common in the low versus the high SES group over the study period. Heavy drinking, hypertension and hypercholesterolemia were not socially patterned among women. CONCLUSION: The prevalence of several CVRFs was higher in low versus high SES groups in a rapidly developing country in the African region, and an increase of the burden of these CVRFs in the most disadvantaged groups of the population was observed over the 15 years study period.

The likelihood approach to compare populations : a study on DNA evidence and pitfalls of intuitions

The paper follows on from earlier work [Taroni F and Aitken CGG. Probabilistic reasoning in the law, Part 1: assessment of probabilities and explanation of the value of DNA evidence. Science & Justice 1998; 38: 165-177]. Different explanations of the value of DNA evidence were presented to students from two schools of forensic science and to members of fifteen laboratories all around the world. The responses were divided into two groups; those which came from a school or laboratory identified as Bayesian and those which came from a school or laboratory identified as non-Bayesian. The paper analyses these responses using a likelihood approach. This approach is more consistent with a Bayesian analysis than one based on a frequentist approach, as was reported by Taroni F and Aitken CGG. [Probabilistic reasoning in the law, Part 1: assessment of probabilities and explanation of the value of DNA evidence] in Science & Justice 1998.

Quantitative morphological evidence for incipient species within Lutzomyia quinquefer (Diptera: Psychodidae)

Morphological variation among geographic populations of the New World sand fly Lutzomyia quinquefer (Diptera, Phlebotominae) was analyzed and patterns detected that are probably associated with species emergence. This was achieved by examining the relationships of size and shape components of morphological attributes, and their correlation with geographic parameters. Quantitative and qualitative morphological characters are described, showing in both sexes differences among local populations from four Departments of Bolivia. Four arguments are then developed to reject the hypothesis of environment as the unique source of morphological variation: (1) the persistence of differences after removing the allometric consequences of size variation, (2) the association of local metric properties with meristic and qualitative attributes, rather than with altitude, (3) the positive and significant correlation between metric and geographic distances, and (4) the absence of a significant correlation between altitude and general-size of the insects.

Clara cells drive eosinophil accumulation in allergic asthma.

Development of allergic asthma is a complex process involving immune, neuronal and tissue cells. In the lung, Clara cells represent a major part of the "immunomodulatory barrier" of the airway epithelium. To understand the contribution of these cells to the inflammatory outcome of asthma, disease development was assessed using an adjuvant-free ovalbumin model. Mice were sensitised with subcutaneous injections of 10 μg endotoxin-free ovalbumin in conjunction with naphthalene-induced Clara cell depletion. Clara epithelial cell depletion in the lung strongly reduced eosinophil influx, which correlated with decreased eotaxin levels and, moreover, diminished the T-helper cell type 2 inflammatory response, including interleukin (IL)-4, IL-5 and IL-13. In contrast, airway hyperresponsiveness was increased. Further investigation revealed Clara cells as the principal source of eotaxin in the lung. These findings are the first to show that Clara airway epithelial cells substantially contribute to the infiltration of eotaxin-responsive CCR3+ immune cells and augment the allergic immune response in the lung. The present study identifies Clara cells as a potential therapeutic target in inflammatory lung diseases such as allergic asthma.