Trimeric G-proteins of the trans-Golgi network are involved in the formation of constitutive secretory vesicles and immature secretory granules

AbstractNon-hydrolysable analogues of GTP, such as GTPγS and GMP-PNP, have previously been shown to inhibit the formation of constitutive secretory vesicles (CSVs) and immature secretory granules (ISGs) from the trans-Golgi network (TGN). Using a cell-free system, we show here that the formation of these vesicles is also inhibited by [AIF4], a compound known to act on trimeric G-proteins. Addition of highly purified G-protein βγ subunits stimulated, in a differential manner, the cell-free formation of both CSVs and ISGs. ADP-ribosylation experiments revealed the presence of a pertussis toxin-sensitive G-protein α subunit in the TGN. We conclude that trimeric G-proteins regulate the formation of secretory vesicles from the TGN

Increased PAI-1 plasma levels and risk of death from dengue: no association with the 4G/5G promoter polymorphism

BACKGROUND: Dengue virus infected patients have high plasminogen activator inhibitor type I (PAI-1) plasma concentrations. Whether the insertion/deletion (4G/5G) polymorphism in the promotor region of the PAI-1 gene is associated with increased PAI-1 plasma concentrations and with death from dengue is unknown. We, therefore, investigated the relationship between the 4G/5G polymorphism and PAI-1 plasma concentrations in dengue patients and risk of death from dengue. METHODS: A total of 194 patients admitted to the Dr. Kariadi Hospital in Semarang, Indonesia, with clinical suspected severe dengue virus infection were enrolled. Blood samples were obtained on day of admission, days 1, 2 and 7 after admission and at a 1-month follow-up visit. Plasma concentrations of PAI-1 were measured using a sandwich ELISA kit. The PAI-1 4G/5G polymorphism was typed by allele-specific PCR analysis. RESULTS: Concentrations of PAI-1 on admission and peak values of PAI-1 during admission were higher than the values measured in healthy controls. Survival was significantly worse in patients with PAI-1 concentrations in the highest tertile (at admission: OR 4.7 [95% CI 0.9–23.8], peak value during admission: OR 6.3 [95%CI 1.3–30.8]). No association was found between the PAI-1 4G/5G polymorphism, and PAI-1 plasma concentrations, dengue disease severity and mortality from dengue. CONCLUSION: These data suggest that the 4G/5G polymorphism has no significant influence on PAI-1 concentrations in dengue virus infected patients and is not associated with the risk of death from dengue. Other factors contributing to the variability of PAI-1 plasma concentrations in patients with dengue need to be explored

Grupo de Estudos e Pesquisa sobre o Trabalho Docente

He objective of this text is to present the research group GEPTRADO of the State University of Ponta Grossa and the trajectory of the research carried out on the theme of teacher training and its practices. From the history of the group the research lines are presented, the theoretical foundations that support the epistemological axis adopted by the researchers, the completed and developing researches. The body of the production of this group is materialized in researches developed by undergraduate students, master's and doctoral students of the University's Graduate Program in addition to the group's collective projects. In highlighting the results of the main research carried out by GEPTRADO, we intend to offer contributions to dialogue between teacher training and basic education.O objetivo deste texto é apresentar o grupo de pesquisa GEPTRADO da Universidade Estadual de Ponta Grossa e a trajetória das pesquisas realizadas sobre a temática da formação de professores e suas práticas. A partir do histórico do grupo são apresentadas as linhas de pesquisa, os fundamentos teóricos que sustentam o eixo epistemológico adotado pelas pesquisadoras, as pesquisas concluídas e em desenvolvimento. O corpo da produção deste grupo se materializa em pesquisas desenvolvidas por acadêmicos da graduação, dos mestrandos e doutorandos do Programa de Pós-graduação da Universidade, além dos projetos coletivos do grupo. Ao destacar os resultados das principais pesquisas realizadas pelo GEPTRADO e grupos afins pretende-se oferecer contribuições para dialogar formação de professores e com a educação básica

Botanical origin of triterpenoids from Yucatecan propolis

Propolis is a resinous material produced by bees from plant exudates; the most common secondary metabolites found in propolis are poliphenolics with different biological activities. Nevertheless, to date, there are a number of reports describing the presence of triterpenoids in propolis. This work describes the isolation and identification of the triterpenoids mangiferolic acid (1), iso-mangiferolic acid (2), and dammarenediol II (3), together with a number of ubiquitous pentacyclic triterpenes, from the extract of a propolis sample collected in Yucatan, Mexico. While the cycloartanes 1 and 2 have been reported previously from propolis samples collected in Africa, Asia and South America, this is the first report of 3 as a component in propolis. The botanical origin of 3 and the pentacyclic triterpenes has been traced to the resin of Bursera simaruba, a tree commonly found in Yucatan peninsula. The results of this investigation confirm the close relationship between the flora surrounding the beehive and the chemical composition of propoli

Transition from fresh frozen plasma to solvent/detergent plasma in the Netherlands: comparing clinical use and transfusion reaction risks

Plasma transfusion is indicated for replenishment of coagulative pro- teins to stop or prevent bleeding. In 2014, the Netherlands switched from using similar to 300mL fresh frozen plasma (FFP) units to using 200mL Omniplasma, a solvent/detergent treated pooled plasma (SD plasma), units. We evaluated the effect of the introduction of SD plasma on clinical plasma use, associated bleeding, and transfusion reaction incidences. Using diagnostic data from six Dutch hospitals, national blood bank data, and national hemovigilance data for 2011 to 2017, we compared the plasma/red blood cell (RBC) units ratio (f) and the mean number of plasma and RBC units transfused for FFP (similar to 300mL) and SD plasma (200mL) for various patient groups, and calculated odds ratios comparing their associated transfusion reaction risks. Analyzing 13,910 transfusion episodes, the difference (Delta f = f(SD) (-) f(FFP)) in mean plasma/RBC ratio (f) was negligible (Delta f(entire-cohort) = 0.01 [95% confidence interval (CI): -0.02 - 0.05]; P=0.48). SD plasma was associated with fewer RBC units transfused per episode in gynecological (difference of mean number of units -1.66 [95% CI: -2.72, -0.61]) and aneurysm (-0.97 [-1.59, -0.35]) patients. SD plasma was further associated with fewer anaphylactic reactions than FFP (odds ratio 0.37 [0.18, 0.77; P<0.01]) while the differences for most transfusion reactions were not statistically significant. SD plasma units, despite being one third smaller in volume than FFP units, are not associated with a higher plasma/RBC ratio. SD plasma is associated with fewer anaphylactic reactions than FFP plasma/RBC units ratio.Clinical epidemiolog

Storage of Factor VIII Variants with Impaired von Willebrand Factor Binding in Weibel-Palade Bodies in Endothelial Cells

BACKGROUND: Point mutations resulting in reduced factor VIII (FVIII) binding to von Willebrand factor (VWF) are an important cause of mild/moderate hemophilia A. Treatment includes desmopressin infusion, which concomitantly increases VWF and FVIII plasma levels, apparently from storage pools containing both proteins. The source of these VWF/FVIII co-storage pools and the mechanism of granule biogenesis are not fully understood. METHODOLOGY/PRINCIPAL FINDINGS: We studied intracellular trafficking of FVIII variants implicated in mild/moderate hemophilia A together with VWF in HEK293 cells and primary endothelial cells. The role of VWF binding was addressed using FVIII variants displaying reduced VWF interaction. Binding studies using purified FVIII proteins revealed moderate (Arg2150His, Del2201, Pro2300Ser) to severe (Tyr1680Phe, Ser2119Tyr) VWF binding defects. Expression studies in HEK293 cells and primary endothelial cells revealed that all FVIII variants were present within VWF-containing organelles. Quantitative studies showed that the relative amount of FVIII storage was independent of various mutations. Substantial amounts of FVIII variants are co-stored in VWF-containing storage organelles, presumably by virtue of their ability to interact with VWF at low pH. CONCLUSIONS: Our data suggest that the potential of FVIII co-storage with VWF is not affected in mild/moderate hemophilia A caused by reduced FVIII/VWF interaction in the circulation. These data support the hypothesis that Weibel-Palade bodies comprise the desmopressin-releasable FVIII storage pool in vivo