Análisis del transporte peritoneal de potasio mediante pruebas de equilibrio peritoneal con diferentes concentraciones de glucosa / Correlates of potassium transport during peritoneal equilibration tests using different dialysate glucose concentrations

Introducción: El conocimiento de los factores que determinan el transporte peritoneal de potasio en diálisis peritoneal (DP) es incompleto. Los objetivos de este estudio fueron comparar el transporte peritoneal de potasio en pruebas de equilibrio peritoneal (PEP) con soluciones de glucosa al 2,27 y al 3,86%, y desvelar factores con influencia en este fenómeno. Método: Noventa pacientes en DP fueron sometidos a PEP al 2,27 y al 3,86%, en orden aleatorio. Comparamos el transporte de potasio en ambas pruebas, buscando correlaciones del cociente D/P de potasio a 240 minutos (variable principal) con marcadores de función peritoneal durante PEP, y con diferentes variables demográficas, clínicas y bioquímicas, usando una estrategia multivariante. Resultados: El D/P de potasio presentó buena concordancia en ambas PEP, mostrando asociación univariante con el D/P de creatinina, pero no con potasio plasmático, ultrafiltración o descenso de sodio. La edad, tipo de DP, carga peritoneal de glucosa, icodextrina, tratamiento con IECA-ARA o calcioantagonistas, potasio urinario y filtrado glomerular tuvieron una correlación univariante con el transporte de potasio. En el análisis multivariante, el D/P de creatinina a 240 minutos (B = 0,40 [IC 95%: 0,26-0,53] 2,27%; B = 0,36 [0,21-0,51] 3,86%; p <0,0005) fue el predictor esencial del D/P de potasio a 240’. La excreción urinaria de potasio también tuvo una correlación inversa con la variable principal. Asimismo, el tratamiento con IECA-ARA se asoció de forma consistente con el transporte peritoneal de potasio, pero sólo en la PEP al 3,86% (B = 0,08 [0,04-0,12]; p <0,0005). Conclusiones: Las PEP al 2,27 y al 3,86% estiman de manera concordante el transporte peritoneal de potasio. Aunque el transporte de creatinina es el predictor principal del de potasio, la excreción urinaria de potasio y el tratamiento con IECA-ARA se asocian de manera independiente con el fenómeno citado (AU)

BBackground: There are gaps in the knowledge of factors which influence peritoneal potassium transport in peritoneal dialysis (PD). The aims of this study were to compare peritoneal potassium transport in PD patients undergoing 2.27% and 3.86% peritoneal equilibration tests (PET), and to disclose clinical correlates of this phenomenon. Method: Ninety PD patients underwent 2.27% and 3.86% PET, in a random order. We compared peritoneal potassium transport in both tests, and searched for correlations between D/P potassium at 240 minutes (main study variable) and PET-derived markers of peritoneal function and selected demographic, clinical and biochemical variables, using a multivariate approach. Main results: D/P potassium showed a good agreement between both PET, and presented a univariate association with creatinine transport, but not with plasma potassium, ultrafiltration or sodium dip. Age, PD modality, peritoneal glucose load, icodextrin, ACEI-ARA and calcium antagonist therapy, urinary potassium and glomerular filtration rate were other univariate correlates of potassium transport. Multivariate analysis confirmed D/P creatinine at 240 minutes (B = 0.40 [95% CI 0.26-0.53] 2.27%, B = 0.36 [0.21-0.51] 3.86%,p <0.0005) as the main predictor of D/P potassium at 240’. Urinary potassium, rather than glomerular filtration rate, sustained also an inverse correlation with the dependent variable. Treatment with ACEI-ARA was consistently associated with peritoneal potassium transport (3.86% PET) (B = 0,08 [0.04-0.12], p <0.0005). Conclusions: The 2.27% and the 3.86% PET show a good agreement at the time of estimating peritoneal potassium transport. Urinary potassium excretion and treatment with ACEI-ARA (3.86% test) show an independent association with peritoneal potassium transport rate (AU)

Isolation and intracellular localization of insulin-like proteins from leaves of Bauhinia variegata

Evidence based on immunological cross-reactivity and anti-diabetic properties has suggested the presence of insulin-like peptides in plants. The objective of the present study was to investigate the presence of insulin-like proteins in the leaves of Bauhinia variegata ("pata-de-vaca", "mororó"), a plant widely utilized in popular medicine as an anti-diabetic agent. We show that an insulin-like protein was present in the leaves of this plant. A chloroplast protein with a molecular mass similar to that of bovine insulin was extracted from 2-mm thick 15 percent SDS-PAGE gels and fractionated with a 2 x 24 cm Sephadex G-50 column. The activity of this insulin-like protein (0.48 mg/mL) on serum glucose levels of four-week-old Swiss albino (CF1) diabetic mice was similar to that of commercial swine insulin used as control. Further characterization of this molecule by reverse-phase hydrophobic HPLC chromatographic analysis as well as its antidiabetic activity on alloxan-induced mice showed that it has insulin-like properties. Immunolocalization of the insulin-like protein in the leaves of B. variegata was performed by transmission electron microscopy using a polyclonal anti-insulin human antibody. Localization in the leaf blades revealed that the insulin-like protein is present mainly in chloroplasts where it is also found associated with crystals which may be calcium oxalate. The presence of an insulin-like protein in chloroplasts may indicate its involvement in carbohydrate metabolism. This finding has strengthened our previous results and suggests that insulin-signaling pathways have been conserved through evolution.

Effect of sugars on the association between cowpea vicilin (7S storage proteins) and fungal cells

Vicilins (7S storage proteins) found in various legume seeds have been previously shown to interfere with the germination of spores or conidia of phytopathogenic fungi and inhibit yeast growth and glucose stimulated acidification of the medium by yeast cells. In the present work vicilins from cowpea (Vigna unguiculata) seeds were added to the growth medium of Saccharomyces cerevisiae cells and Fusarium oxysporum conidia. Helix pomatia lectin, wheat germ agglutinin and Ulex europaeus lectin were used to identify differences in the binding of the vicilins to the surface of cells of S. cerevisiae and F. oxysporum treated with this protein. After the growth period, the material in suspension (yeast cells) was centrifuged and the final pellet was also treated with different sugar (glucose, sucrose, glucosamine, N-acetyl-glucosamine) concentrations and 0.1 M HCl for extraction of vicilins associated to chitinous structures present in yeast cells. Our results showed that vicilin sub-units were present in the different sugar extracts of yeast cells pretreated with the vicilins and these proteins were eluted by 0.5 M solutions of sugars in the following order of efficiency of elution: N-acetyl-glucosamine, sucrose/glucose and glucosamine.

Effect of sugars on the association between cowpea vicilin (7S storage proteins) and fungal cells

Vicilins (7S storage proteins) found in various legume seeds have been previously shown to interfere with the germination of spores or conidia of phytopathogenic fungi and inhibit yeast growth and glucose stimulated acidification of the medium by yeast cells. In the present work vicilins from cowpea (Vigna unguiculata) seeds were added to the growth medium of Saccharomyces cerevisiae cells and Fusarium oxysporum conidia. Helix pomatia lectin, wheat germ agglutinin and Ulex europaeus lectin were used to identify differences in the binding of the vicilins to the surface of cells of S. cerevisiae and F. oxysporum treated with this protein. After the growth period, the material in suspension (yeast cells) was centrifuged and the final pellet was also treated with different sugar (glucose, sucrose, glucosamine, N-acetyl-glucosamine) concentrations and 0.1 M HCl for extraction of vicilins associated to chitinous structures present in yeast cells. Our results showed that vicilin sub-units were present in the different sugar extracts of yeast cells pretreated with the vicilins and these proteins were eluted by 0.5 M solutions of sugars in the following order of efficiency of elution: N-acetyl-glucosamine, sucrose/glucose and glucosamine. (AU)

Leprosy elimination campaign, Amazonas-Brazil 1997.

A leprosy elimination campaign (LEC) was carried out in 15 endemic areas of Amazonas State, Brazil, in 1997. The LEC concentrated effort to detect leprosy cases during a multi-vaccination national campaign for serious public health problems other than leprosy, such as polio, diphtheria, hepatitis, measles, etc. The national campaign involved intensive population mobilization, giving a valuable opportunity to examine people for leprosy. The LEC personnel included 2964 individuals (municipal and state health workers and community volunteers), distributed in 688 health units and 53 reference health centres. As a result of the LEC, 74,814 person-to-person communications in the community were given; 10,297 clinical skin examinations were conducted, and 40 new leprosy cases were detected on the day of the campaign in urban areas of the municipalities. This total was low, compared to results in other states of Brazil, possibly due to the development of health education activities and regular community services in the state of Amazonas since 1987 and to the early implementation of WHO multiple drug therapy (MDT) from 1982 onwards. Despite the fact that the LEC was carried out only in the urban areas of the municipalities, the finding of no cases of leprosy in 7 out of 15 of them was surprising and may indicate that the prevalence of hidden cases of leprosy is not all that high, at least in these areas of the Amazonas State.

Evaluation of potential genotoxicity of stannous chloride: inactivation, filamentation and lysogenic induction of Escherichia coli.

Because of the importance of stannous chloride in various fields of human endeavour, the potential genotoxicity of this reducing agent was evaluated by measurement of either the inactivation or the induction of SOS responses in bacteria. Escherichia coli strains used in this work (wild type, uvrA, recA, lexA and uvrA recA) were treated with stannous chloride; the wild type was found to be the most resistant and the double mutant, the most sensitive strain. As these strains present mutations on specific genes for the repair of DNA, stannous chloride would appear to be capable of inducing and/or producing lesions in DNA and, thus, can be considered to be a potential genotoxic agent. This capability was confirmed by the lysogenic induction of E. coli K12 (lambda) (Inductest) and by microscopic observation of E. coli B filamentation.