Liver fat, visceral adiposity, and sleep disturbances contribute to the development of insulin resistance and glucose intolerance in nondiabetic dialysis patients

Hemodialysis patients exhibit insulin resistance (IR) in target organs such as liver, muscles, and adipose tissue. The aim of this study was to identify contributors to IR and to develop a model for predicting glucose intolerance in nondiabetic hemodialysis patients. After a 2-h, 75-g oral glucose tolerance test (OGTT), 34 hemodialysis patients were divided into groups with normal (NGT) and impaired glucose tolerance (IGT). Indices of insulin sensitivity were derived from OGTT data. Measurements included liver and muscle fat infiltration and central adiposity by computed tomography scans, body composition by dual energy X-ray absorptiometer, sleep quality by full polysomnography, and functional capacity and quality of life (QoL) by a battery of exercise tests and questionnaires. Cut-off points, as well as sensitivity and specificity calculations were based on IR (insulin sensitivity index by Matsuda) using a receiver operator characteristics (ROC) curve analysis. Fifteen patients were assigned to the IGT, and 19 subjects to the NGT group. Intrahepatic fat content and visceral adiposity were significantly higher in the IGT group. IR indices strongly correlated with sleep disturbances, visceral adiposity, functional capacity, and QoL. Visceral adiposity, O2 desaturation during sleep, intrahepatic fat content, and QoL score fitted into the model for predicting glucose intolerance. A ROC curve analysis identified an intrahepatic fat content of > 3.97% (sensitivity, 100; specificity, 35.7) as the best cutoff point for predicting IR. Visceral and intrahepatic fat content, as well as QoL and sleep seemed to be involved at some point in the development of glucose intolerance in hemodialysis patients. Means of reducing fat depots in the liver and splachnic area might prove promising in combating IR and cardiovascular risk in hemodialysis patients.     

Serologic survey of West Nile virus in horses from Central-West,Northeast and Southeast Brazil

Since the emergence of West Nile virus (WNV) in North America in 1999, there have been several reports of WNV activity in Central and South American countries. To detect WNV in Brazil, we performed a serological survey of horses from different regions of Brazil using recombinant peptides from domain III of WNV. Positive samples were validated with the neutralisation test. Our results showed that of 79 ELISA-positive horses, nine expressed WNV-specific neutralising antibodies. Eight of the infected horses were from the state of Mato Grosso do Sul and one was from the state of Paraíba. Our results provide additional evidence for the emergence of WNV in Brazil and for its circulation in multiple regions of the country.     

Souring control in fluid samples of oil industry using a multiple ligand simultaneous docking (MLSD) strategy

We have used docking techniques in order to propose potential inhibitors to the enzymes adenosine phosphosulfate reductase and adenosine triphosphate sulfurylase that are responsible, among other deleterious effects, for causing souring of oil and gas reservoirs. Three candidates selected through molecular docking revealed new and improved polar and hydrophobic interactions with the above-mentioned enzymes. Microbiological laboratory assays performed subsequently corroborated the results of computer modelling that the three compounds can efficiently control the biogenic sulfide production.     

Differences in the Detection of BrdU/EdU Incorporation Assays Alter the Calculation for G1, S,and G2 Phases of the Cell Cycle in Trypanosomatids

Trypanosomatids are the etiologic agents of various infectious diseases in humans. They diverged early during eukaryotic evolution and have attracted attention as peculiar models for evolutionary and comparative studies. Here, we show a meticulous study comparing the incorporation and detection of the thymidine analogs BrdU and EdU in Leishmania amazonensis, Trypanosoma brucei, and Trypanosoma cruzi to monitor their DNA replication. We used BrdU‐ and EdU‐incorporated parasites with the respective standard detection approaches: indirect immunofluorescence to detect BrdU after standard denaturation (2 M HCl) and “click” chemistry to detect EdU. We found a discrepancy between these two thymidine analogs due to the poor detection of BrdU, which is reflected on the estimative of the duration of the cell cycle phases G1, S, and G2. To solve this discrepancy, we increase the exposure of incorporated BrdU using different concentrations of HCl. Using a new value for HCl concentration, we re‐estimated the phases G1, S, G2 + M, and cytokinesis durations, confirming the values found by this approach using EdU. In conclusion, we suggest that the studies using BrdU with standard detection approach, not only in trypanosomatids but also in others cell types, should be reviewed to ensure an accurate estimation of DNA replication monitoring.     

Widespread hybridization within mound‐building wood ants in Southern Finland results in cytonuclear mismatches and potential for sex‐specific hybrid breakdown

Hybridization and gene flow between diverging lineages are increasingly recognized as common evolutionary processes, and their consequences can vary from hybrid breakdown to adaptive introgression. We have previously found a population of wood ant hybrids between Formica aquilonia and F. polyctena that shows antagonistic effects of hybridization: females with introgressed alleles show hybrid vigour, whereas males with the same alleles show hybrid breakdown. Here, we investigate whether hybridization is a general phenomenon in this species pair and analyse 647 worker samples from 16 localities in Finland using microsatellite markers and a 1200‐bp mitochondrial sequence. Our results show that 27 sampled nests contained parental‐like gene pools (six putative F. polyctena and 21 putative F. aquilonia) and all remaining nests (69), from nine localities, contained hybrids of varying degrees. Patterns of genetic variation suggest these hybrids arise from several hybridization events or, instead, have backcrossed to the parental gene pools to varying extents. In contrast to expectations, the mitochondrial haplotypes of the parental species were not randomly distributed among the hybrids. Instead, nests that were closer to parental‐like F. aquilonia for nuclear markers preferentially had F. polyctena's mitochondria and vice versa. This systematic pattern suggests there may be underlying selection favouring cytonuclear mismatch and hybridization. We also found a new hybrid locality with strong genetic differences between the sexes similar to those predicted under antagonistic selection on male and female hybrids. Further studies are needed to determine the selective forces that act on male and female genomes in these newly discovered hybrids.     

Potential natural vegetation and pre‐anthropic pollen records on the Azores Islands in a Macaronesian context

This paper discusses the concept of potential natural vegetation (PNV) in the light of the pollen records available to date for the Macaronesian biogeographical region, with emphasis on the Azores Islands. The classical debate on the convenience or not of the PNV concept has been recently revived in the Canary Islands, where pollen records of pre‐anthropic vegetation seemed to strongly disagree with the existing PNV reconstructions. Contrastingly, more recent PNV model outputs from the Azores Islands show outstanding parallelisms with pre‐anthropic pollen records, at least in qualitative terms. We suggest the development of more detailed quantitative studies to compare these methodologies as an opportunity for improving the performance of both. PNV modelling may benefit by incorporating empirical data on past vegetation useful for calibration and validation purposes, whereas palynology may improve past reconstructions by minimizing interpretative biases linked to differential pollen production, dispersal and preservation.     

Uses, management, and economic potential ofDacryodes edulis (Burseraceae) in the Humid Lowlands of Cameroon

Dacryodes edulis is one of the most preferred tree species by farmers in the humid lowlands of Cameroon. The fruit of the species figures prominently in cross-boundary trade between Cameroon, Nigeria and Gabon. Although there exist empirical data on the volume of trade of the fruit at this level, no data are available at the farm level. A field survey was undertaken to identify uses, management, and farmers’ improvement objectives and to quantify, at the farm-level, the economic potential of the species. The results of the survey indicate thatD. edulis is widely planted and found mainly in tree crop fields and in home gardens. The fruit is highly consumed and traded. The farm-level value of fruit production reaches $US161 a year per grower or collector. The dead branches of the species are used as firewood and its bark is used as medicine. Desired improvement objectives include increased fruit size, good tasting fruit, high yield and reduced time to bearing.