Superoxide Anion Production by Human Neutrophils Activated by Trichomonas vaginalis

Neutrophils are the predominant inflammatory cells found in vaginal discharges of patients infected with Trichomonas vaginalis. In this study, we examined superoxide anion (O2(.-)) production by neutrophils activated by T. vaginalis. Human neutrophils produced superoxide anions when stimulated with either a lysate of T. vaginalis, its membrane component (MC), or excretory-secretory product (ESP). To assess the role of trichomonad protease in production of superoxide anions by neutrophils, T. vaginalis lysate, ESP, and MC were each pretreated with a protease inhibitor cocktail before incubation with neutrophils. Superoxide anion production was significantly decreased by this treatment. Trichomonad growth was inhibited by preincubation with supernatants of neutrophils incubated for 3 hr with T. vaginalis lysate. Furthermore, myeloperoxidase (MPO) production by neutrophils was stimulated by live trichomonads. These results indicate that the production of superoxide anions and MPO by neutrophils stimulated with T. vaginalis may be a part of defense mechanisms of neutrophils in trichomoniasis.

Ácido siálico sérico, carga aniónica y agregación eritrocitaria en pacientes diabéticos e hipertensos / Serum sialic acid, cellular anionic charge and erythrocyte aggregation in diabetic and hypertensive patients

El objetivo de este trabajo fue estudiar la relación del ácido siálico sérico (AS) y la carga aniónica eritrocitaria (CAE) con la agregación eritrocitaria en dos grupos de pacientes: diabéticos (DBT n= 20) e hipertensos (HTA n= 21), comparados con un grupo control (n= 20). Se trabajó con sangre anticoagulada con EDTA y suero. La agregación eritrocitaria se estudió por observación microscópica de los agregados y cuantificación a través de un parámetro de forma denominado ASP (Aggregation Shape Parameter). La CAE se determinó por unión a colorante alcian blue y el AS por método espectrofotométrico con reactivo de Erlich. Los valores de ASP y AS resultaron significativamente aumentados en los HTA y DBT respecto de los normales. Los HTA y DBT presentaron agregados amorfos, lo que se refleja en los valores alterados de ASP, significativamente mayores (p < 0.005) respecto de los individuos normales. Los valores de CAE resultaron significativamente inferiores en los HTA y DBT respecto del grupo control (p < 0.0001). En este trabajo se demostraron anormalidades en la agregación eritrocitaria, detectadas por los valores de ASP, CAE y AS que podrían estar involucradas en las complicaciones vasculares de vasculopatías como la hipertensión y la diabetes.

The aim of this work was to study the relationship between serum sialic acid (SSA) and erythrocyte anionic charge (EAC) with erythrocyte aggregation in two groups: diabetic (DBT, n=20) and hypertensive (HT, n=21) patients, compared to a control group (n=20). We worked with anticoagulated blood with EDTA and serum. The erythrocyte aggregation was studied by microscopically observing and quantifying aggregates using an ASP (Aggregate Shape Parameter). The EAC was determined by binding an Alcian blue dye to the membrane sialic acid and SSA was determined by spectrophotometric method with an Erlich reactant. The values of ASP and SSA increased significantly in HT and DBT patients compared to the control group. The HT and DBT groups showed amorphous aggregates, evident in an alteration in the values of ASP, which were significantly higher ( p< 0.005) than in healthy patients. The EAC values were much lower in HT and DBT patients than in the control group (p < 0.0001). In this work, abnormalities in the erythrocyte aggregation could be detected by the values of ASP, EAC and SSA, which might be involved in vascular disorders of diseases such as hypertension and diabetes.

Optimization of extracellular xylanase production by Sclerotinia sclerotiorum S2 using factorial design.

The improvement of xylanase production by Sclerotinia sclerotiorum S2 using a liquid fermentation culture was investigated. The optimized process was divided into three basic steps: (i) evaluating xylanase inducers using different agricultural residues such as wheat bran, oat bran, orange peel and barley bran at 1% final concentration, and also filter paper. Among these, wheat bran showed the maximum activity (2.5 U/ml) at 12 days post-inoculation; (ii) for optimization, we determined the optimal concentration of inducer, the effect of phosphate anion (K2HPO4/KH2PO4) and culture aeration using a rotary shaker at 100 and 180 rpm. The optimal conditions for these three factors were determined in an experimental panel using factorial data, in which a mathematical model (Minitab software) was fitted; (iii) The optimized culture medium containing a high level of wheat bran (3%) without KH2PO4-K2HPO4 and submitted to a high agitation (180 rpm/min) increased the xylanase production from 2.5 U/ml to 4 U/ml (1.6-fold).

Expression of volume-activated anion channels in exocrine acinar cells

No abstract available.

Calcium-dependent and -independent mechanisms of P2Y receptor regulated anion secretion in polarized epithelia

No abstract available.

CFTR, a rectifying, non-rectifying anion channel?

No abstract available.

Nuevos conocimientos del transporte de aminoácidos aniónicos y catiónicos / Advances in the study of anionic and cationic amino acid transport

En las células de mamíferos, los aminoácidos son captados por diferentes sistemas de transporte presentes en la membrana plasmática. Los sistemas de transporte originalmente se caracterizaron a través de estudios cinéticos y de competencias. Sin embargo, el asignamiento de algunos aminoácidos a un sistema de transporte específico había sido difícil. Con los avances en biología molecular ha sido posible identificar a las proteínas de los transportadores para aminoácidos específicos. En esta revisión se describen los sintomas de transporte para aminoácidos aniónicos y catiónicos que se han reportado a nivel molecular. Los aminoácidos aniónicos se movilizan principalmente a través de los sistemas XAG- y Xc-, los cuales son de particular relevancia en la inactivación de la transmisión nerviosa glutamatérgica en el cerebro y en la síntesis de glutation, respectivamente. Se han descrito cuatro isoformas cerebrales del sistema XAG- pertenecientes a la familia de transportadores de aminoácidos dependientes de Na+. Los sistemas de transporte para los aminoácidos catiónicos también reconocen sustratos zwitteriónicos, y los más estudiados son el y+, y+L, bº + y Bº + La regulación de la entrada de aminoácidos catiónicos tales como la arginina, lisina, y ornitina es importante en la biosíntesis de oxido nítrico, creatina, carnitina y poliaminas. La cisteinuría es un defecto hereditario asociado al sistema bº +

Possible roles of nitric oxide and peroxynitrite in murine leishmaniasis

Activated macrophages simultaneously synthesize nitric oxide and superoxide anion which can react with each other producing peroxynitrite. Consequently, it has been difficult to assess the precise contribution of each of the formed reactive oxygen- and nitrogenderived species to the microbicidal activities of macrophages, particularly in vivo. To explore this problem, we are examining the formation and potential roles of nitrogen-derived intermediates in Leishmania amazonensis murine infection. Thus far, our results have demonstrated that peroxynitrite is a potent leishmanicidal agent in vitro and that both nitric oxide and peroxynitrite are formed during infection of susceptible BALB/c mouse strain. Nitric oxide was detected as the nitrosyl-hemoglobin complex by electron paramagnetic resonance analysis of blood drawn from mice at different times of infection, and it was shown to increase with the evolution of the disease. These results will be discussed in the context of the dual physiological role of nitric oxide either as a signaling molecule or as a deleterious agent.