Tratamiento etiológico de trypanosoma cruzi con benznidazol y nifurtimox en áreas rurales / Trypanosoma cruzi etiologic treatment with benznidazole and nifurtimox in rural areas

INTRODUCCIÓN El nifurtimox (NF) y el benznidazol (BZ) se emplean para el tratamiento (TTO) de Trypanosoma cruzi y provocan una caída de la carga parasitaria, que prevendría el desarrollo y/o progresión de la enfermedad. Es importante identificar estrategias que aseguren el acceso temprano al diagnóstico y al TTO, así como una logística para el manejo de efectos adversos (EA). OBJETIVOS Comparar el manejo del TTO con BZ y NF en poblaciones rurales vulnerables. MÉTODOS Se realizó el TTO con BZ a 90 residentes de un área rural de Pampa del Indio en 2010. En 2013, se inició el TTO con NF a 37 pacientes. Las actividades de diagnóstico y TTO fueron planificadas participativamente con la comunidad. Se compararon planificaciones y resultados del TTO (tipo y manejo de EA, adherencia, porcentaje de culminación) entre ambas áreas. La eficacia del TTO se evaluó mediante marcadores moleculares (PCR cuali y cuantitativa). Resultados Completaron el TTO el 85% y el 92% de los pacientes tratados con BZ y NF, respectivamente. El exantema fue el EA más frecuente (28/34) al realizar TTO con BZ, mientras que las cefaleas lo fueron en el TTO con NF (12/20). El tiempo medio de aparición de EA fue de 12 días (BZ) y 11 días (NF). Los pacientes con EA no modificaron el TTO (BZ 53%; NF 80%), lo disminuyeron transitoriamente (BZ 12%; NF 5%) o lo interrumpieron por indicación médica (BZ: 15%; NF 10%) o sin ella (BZ 20%; NF 5%).

Trans-sialidase inhibition assay for the detection of Trypanosoma cruzi infection in blood donor samples from Argentina.

BACKGROUND AND OBJECTIVES: Conventional serology tests for Trypanosoma cruzi blood banks screening are neither sensitive nor specific enough, and currently no gold standard assay is available. Trans-sialidase inhibition assay (TIA) detects neutralizing antibodies against T. cruzi trans-sialidase. Conventional serology inconclusive, positive and negative blood donor samples were evaluated by employing TIA as a supplementary test. MATERIALS AND METHODS: Three hundred and twenty-one blood donor samples were tested using a combination of assays. Based on the results of testing, these were divided into a number of groups. All samples were tested by TIA. RESULTS: In conventional serology inconclusive samples 48.1% were TIA-positive, 1/54 conventional serology positive samples was TIA-negative. All negative samples from donors without epidemiological risks were TIA-negative; 1/48 was positive in those with epidemiological risk. CONCLUSION: Trans-sialidase inhibition assay application in blood banks may be useful to resolve inconclusive samples, and thus improves donor counseling and allows individual re-entry. The use of TIA in samples from negative conventional test donors but positive epidemiological antecedents may contribute to decrease transfusional risk.

Effects of Cl(-) substitution on electrophysiological properties, Ca(2+) influx and prolactin secretion of rat lactotropes in vitro.

In this study, we compared the effects of different chloride (Cl(-)) substitutes - methane sulfonate (CH(3)SO(-)(3)), bromide (Br(-)), nitrate (NO(-)(3)), thiocyanate (SCN(-)) and perchlorate (ClO(-)(4)) - on the secretory activity and calcium current activation of rat lactotropes in primary culture. We observed that CH(3)SO(-)(3) decreased basal prolactin (PRL) secretion. Br(-) had no effect, whereas the more lyotropic anions, such as NO(-3), SCN(-) and C1O(-4), increased basal PRL secretion. The latter three substitutes induced a significant shift in the voltage dependence of T-type calcium channel activation towards hyperpolarized values. However, this shift alone cannot explain the increase in secretion. Anion permeability studies also demonstrated that the organic anion CH(3)SO(-3) was less permeant than Cl(-), whereas monovalent inorganic anions were more permeant, with the following anion permeability sequence: SCN(-) > ClO(-4) > NO(-3) > Br(-). In conclusion, deprivation of Cl(-) ions has converse consequences on basal and induced secretion; permeating anions result in a transient increase in intracellular Ca(2+) ions. This process involves voltage-dependent Ca(2+) channels. We propose that an alteration in intracellular anion concentrations may influence the activation of internal effectors such as G proteins or channel proteins and, therefore, interfere with exocytosis. These effects are correlated with an external action of lyotropic anions, particularly NO(-3), ClO(-4) and SCN(-), on the gating properties of T-type calcium channels, probably through changes in cell surface charges. The results demonstrate the modulatory effect of anions on the secretory activity of rat lactotropes and underline the specific role played by chloride in stimulus-secretion coupling.