Genetics University of Toronto Thrombophilia Study in Women (GUTTSI): genetic and other risk factors for venous thromboembolism in women

Background  

Women may be at increased risk for venous thromboembolism (VTE) as compared with men. We studied the effects of genetic and biochemical markers of thrombophilia in women, in conjunction with other established risk factors for VTE.     

<i>In vitro</i> evaluation of antifungal activity of Agave (<i>Agave scabra</i>, Salm Dyck) extracts against post-harvest mushrooms

The agricultural sector, and particularly the horticultural production, has a singular importance in agriculture, considering that it ranks second on agricultural products, nationally and worldwide. Fungal diseases are one of the major causes of vegetable loss during storage, reducing their nutritional value, quality and sale price. Vegetables are usually exposed to diverse treatments with chemical products before storage; as a result, fungal populations develop an increased resistance over time becoming more difficult to control. Because of this, research efforts toward finding more suitable chemicals to control fungal diseases are needed. Natural extracts may be an alternative solve this problem. In the present investigation the fungicidal activity of aqueous and ethanol extracts of Agave scabra was evaluated on the growth of Botrytis cinerea, Mucor sp., Aspergillus niger, Fusarium sp. and Penicillium sp., whose strains were isolated from potato and tomato. To assess their effects, the agar-dilution and agar-well techniques were performed. The ethanol extract was more effective against Botrytis cinerea and Mucor sp. when the agar-well method was used. However, when using the agar-dilution method the ethanol extract of Agave scabra inhibited the growth of Botrytis cinerea, Mucor sp. and Penicillium sp.     

Positive selection and sequence rearrangements generate extensive polymorphism in the gamete recognition protein bindin

Bindin is a gamete recognition protein of sea urchins that mediates species-specific attachment of sperm to an egg-surface receptor during fertilization. Sequences of bindin from closely related urchins show fixed species-specific differences. Within species, highly polymorphic bindin alleles result from point substitution, insertion/deletion, and recombination. Since speciation, positive selection favoring allelic variants has generated diversity in bindin polypeptides. Intraspecific bindin variation can be tolerated by the egg receptor, which suggests functional parallels between this system and other flexible recognition systems, including immune recognition. These results show that polymorphism in mate recognition loci required for rapid evolution of sexual isolation can arise within natural populations.      

The molecular evolution of the alcohol dehydrogenase and alcohol dehydrogenase-related genes in the Drosophila melanogaster species subgroup

The DNA sequences of the Adh genes of three members of the Drosophila melanogaster species subgroup have been determined. This completes the Adh sequences of the eight species of this subgroup. Two species, D. yakuba and D. teissieri, possess processed Adh pseudogenes. In all of the species of the subgroup, a gene of unknown function, Adhr, is located about 300 bp 3' to Adh. Although this gene is experiencing a higher rate of synonymous substitution than Adh, it is more constrained at the amino acid level. Phylogenetic relationships between all eight members of the melanogaster subgroup have been analyzed using a variety of methods. All analyses suggested that the D. yakuba and D. teissieri pseudogenes have a single common ancestor, rather than evolving independently in each species, and that D. melanogaster is the sister species to D. simulans, D. sechellia, and D. mauritiana. The evolutionary relationships of the latter three species remain equivocal.      

HERITABILITY OF AEROBIC POWER OF INDIVIDUALS IN NORTHEAST BRAZIL

The objective of this study was to evaluate the genetic and environmental contribution to variation in aerobic power in monozygotic (MZ) and dizygotic (DZ) twins. The sample consisted of 20 MZ individuals (12 females and 8 males) and 16 DZ individuals (12 females and 4 males), aged from 8 to 26 years, residents in Natal, Rio Grande do Norte. The twins were assessed by a multistage fitness test. The rate of heritability found for aerobic power was 77%. Based on the results, the estimated heritability was largely responsible for the differences in aerobic power. This implies that such measures are under strong genetic influence.     

Communicating oscillatory networks: frequency domain analysis

Background

Endothelial permeability is involved in injury, inflammation, diabetes and cancer. It is partly regulated by the thrombin-, histamine-, and VEGF-mediated myosin-light-chain (MLC) activation pathways. While these pathways have been investigated, questions such as temporal effects and the dynamics of multi-mediator regulation remain to be fully studied. Mathematical modeling of these pathways facilitates such studies. Based on the published ordinary differential equation models of the pathway components, we developed an integrated model of thrombin-, histamine-, and VEGF-mediated MLC activation pathways.

Results

Our model was validated against experimental data for calcium release and thrombin-, histamine-, and VEGF-mediated MLC activation. The simulated effects of PAR-1, Rho GTPase, ROCK, VEGF and VEGFR2 over-expression on MLC activation, and the collective modulation by thrombin and histamine are consistent with experimental findings. Our model was used to predict enhanced MLC activation by CPI-17 over-expression and by synergistic action of thrombin and VEGF at low mediator levels. These may have impact in endothelial permeability and metastasis in cancer patients with blood coagulation.

Conclusion

Our model was validated against a number of experimental findings and the observed synergistic effects of low concentrations of thrombin and histamine in mediating the activation of MLC. It can be used to predict the effects of altered pathway components, collective actions of multiple mediators and the potential impact to various diseases. Similar to the published models of other pathways, our model can potentially be used to identify important disease genes through sensitivity analysis of signalling components.     

Glycosphingolipid expression in pig aorta: identification of possible target antigens for human natural antibodies

Total non-acid glycosphingolipids were isolated from the aortas of more than 80 pigs. The glycolipids were separated by HPLC, analysed by thin- layer chromatography, and tested for reactivity with monoclonal anti- blood group antibodies. The fractions were structurally characterized by NMR spectroscopy and mass spectrometry. Reactivity with both anti- blood group A and H antibodies was seen. The major glycosphingolipid constituents were globotri- and globotetraosylceramides and blood group H pentaglycosylceramides based on type 1 and type 2 core saccharide chains. Globopentaosylceramides, blood group H hexaglycosylceramides based on type 4 chain, and blood group A hexaglycosylceramides based on type 1 core chain were also present. Two structures, that may be important targets for human antibodies initiating hyperacute rejection following pig to human xenotransplantation, were present as minor constituents compared to the blood group components. These were Galalpha1,3neolactotetraosylceramide and a Galalpha1, 3Lexstructure. A Leb/Y hexaglycosylceramide was also present.      

Saccharomyces CDK1 Phosphorylates Rad53 Kinase in Metaphase, Influencing Cellular Morphogenesis

Rad53 is an essential protein kinase governing DNA damage and replication stress checkpoints in budding yeast. It also appears to be involved in cellular morphogenesis processes. Mass spectrometry analyses revealed that Rad53 is phosphorylated at multiple SQ/TQ and at SP/TP residues, which are typical consensus sites for phosphatidylinositol 3-kinase-related kinases and CDKs, respectively. Here we show that Clb-CDK1 phosphorylates Rad53 at Ser⁷⁷⁴ in metaphase. This phosphorylation event does not influence the DNA damage and replication checkpoint roles of Rad53, and it is independent of the spindle assembly checkpoint network. Moreover, the Ser-to-Asp mutation, mimicking a constitutive phosphorylation state at site 774, causes sensitivity to calcofluor, supporting a functional linkage between Rad53 and cellular morphogenesis.     

Ethnobiology of snappers (Lutjanidae): target species and suggestions for management

In this study, we sought to investigate the biology (diet and reproduction) and ethnobiology (fishers knowledge and fishing spots used to catch snappers) of five species of snappers (Lutjanidae), including Lutjanus analis, Lutjanus synagris, Lutjanus vivanus, Ocyurus chrysurus, and Romboplites saliens at five sites along the northeast (Riacho Doce, Maceió in Alagoas State, and Porto do Sauípe, Entre Rios at Bahia State) and the southeast (SE) Brazilian coast (Paraty and Rio de Janeiro cities at Rio de Janeiro State, and Bertioga, at São Paulo State.). We collected 288 snappers and interviewed 86 fishermen. The stomach contents of each fish were examined and macroscopic gonad analysis was performed. Snappers are very important for the fisheries of NE Brazil, and our results indicated that some populations, such as mutton snapper (L. analis) and lane snapper (L. synagris), are being caught when they are too young, at early juvenile stages. Local knowledge has been shown to be a powerful tool for determining appropriate policies regarding management of target species, and artisanal fishermen can be included in management processes. Other suggestions for managing the fisheries are discussed, including proposals that could provide motivation for artisanal fishermen to participate in programs to conserve resources, such as co-management approaches that utilize local knowledge, the establishment of fishing seasons, and compensation of fishermen, through 'payment for environmental services'. These suggestions may enhance the participation of local artisanal fishermen in moving to a more realistic and less top-down management approach of the fish population.