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Abstract Worldwide big cats are at risk of extinction, and anthropogenic factors and natural habitat disturbances represent the biggest threats for their survival. It is essential to know the natural resources use by these predators and the way these big felids can adapt to changes. It is unknown how the puma (Puma concolor) selects and uses resources, what environmental factors determine its presence and how this species is affected by natural disturbances in Mexican tropical forests. This study was performed in the Eden ecological reserve and surroundings, in the North of Quintana Roo, Mexico, an area dominated by tropical semideciduous (medium forest) and secondary forest (acahual). Camera samplings were carried out during 2008, and from 2010 to 2012. Habitat variables, activity patterns and species associations were also spatially and temporally analyzed using achi-squared test and overlapping coefficients. General Linear Models (GLM) were used in order to determine which variables influence the presence of cougars in the study area. Cougars used vegetation and paths in different proportions as the availability of these resources. The years with more changes (P < 0.05) were 2008 and 2011. This predator was active throughout the day, but changed its activity patterns over the years. The cougar was spatio-temporally associated with six mammals and two big terrestrial birds: Pecari tajacu (∆ = 0.52), Meleagris ocellata (∆ = 0.55), Crax rubra (∆ = 0.58), Didelphis sp. (∆ = 0.64), Mazama temama (∆ = 0.66), Leopardus pardalis (∆ = 0.68), Dasypus novemcinctus (∆ = 0.73) and Panthera onca (∆ = 0.87). After testing 90 GLM models, the model with a lower AIC value described the activity patterns of prey and co-predators. The vegetation and water in the reserve were important variables for the cougar. However the variables that determined and modified the presence of the species were activity patterns of co-predators and the potential preys. The factors that negatively affected the presence of the species were fire, human presence, and habitat displacement to less favorable habitats to avoid jaguar. Rev. Biol. Trop. 66(1): 78-90. Epub 2018 March 01.

Resumen Los grandes felinos a nivel mundial se encuentran en peligro de extinción. Los factores antropogénicos y las alteraciones naturales representan una gran presión para su sobrevivencia. Es esencial conocer el efecto de estos sobre los depredadores y cómo los felinos se adaptan y usan los recursos naturales. Se desconoce el modo en que el puma (Puma concolor) selecciona y utiliza recursos, cuáles son los factores ambientales que determinan su presencia y cómo esta especie se ve afectada por alteraciones naturales en los bosques tropicales mexicanos. Este estudio se realizó en la reserva ecológica de El Edén y sus alrededores en el norte de Quintana Roo, México, área dominada por selva tropical semidecidua (selva mediana) y bosque secundario (acahual). Se realizaron muestreos con cámaras durante 2008 y 2010-2012. Las variables de hábitat, patrones de actividad y asociaciones de especies también se analizaron espacial y temporalmente mediante una prueba de chi-cuadrado y coeficientes de traslape. Se utilizaron modelos GLM para determinar qué variables influyen en la presencia de pumas en el área de estudio. El puma utiliza la vegetación y caminos en diferente proporción a la de su disponibilidad. Los años con más cambios (P <0.05) fueron 2008 y 2011. Este depredador está activo durante todo el día, pero cambió sus patrones de actividad durante los años. El puma está asociado espacio-temporalmente con siete mamíferos: Pecari tajacu (Δ = 0.52), Meleagris ocelata (Δ = 0.55), Crax rubra (Δ = 0.58), Didelphis sp. (Δ = 0.64), Mazama temama (Δ = 0.66), Leopardus pardalis (Δ = 0.68), Dasypus novemcinctus (Δ = 0.73) y Panthera onca (Δ = 0.87) y dos grandes aves terrestres. Después de probar 90 modelos GLM, el modelo con un valor menor de AIC es el de patrones de actividad de presas y co-depredadores. La vegetación y la disponibilidad de agua en la reserva son variables importantes para el puma. Sin embargo, las variables que determinan y modifican la presencia de la especie son los patrones de actividad de los co-depredadores y las presas potenciales. Los factores que afectan negativamente la presencia de la especie son el fuego, la presencia humana y el desplazamiento a habitas menos favorables para evadir al jaguar.

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El objetivo del presente trabajo fue la evaluación preclínica y el estudio de estabilidad de extractos a partir del follaje de Momordica charantia Lin. Se obtuvieron extractos acuoso e hidroalcohólico para los cuales se establecieron las especificaciones de calidad mediante la evaluación de tres lotes y se estudió su estabilidad por el método de vida de estante durante 12 meses. A los extractos se le evaluó el potencial genotóxico mediante ensayos de micronúcleos en médula ósea de ratón y aberraciones cromosómicas en linfocitos de sangre periférica. La actividad hipoglicemiante oral fue evaluada en animales con hiperglicemia temporal inducida por carga de glucosa. Como resultados se establecieron las especificaciones de calidad de los extractos acuoso e hidroalcohólico, los mismos mostraron estabilidad por 6 meses para el extracto acuoso y 12 meses para el extracto hidroalcohólico. No mostraron efecto genotóxico en los ensayos evaluados y mostraron efecto hipoglicemiante oral a la dosis de 450 mg/kg.

The objective of this investigation was the preclinical evaluation and the stability study of the Momordica charantia Linn hydroalcoholic and aqueous leaf extracts. The hydroalcoholic and aqueous extracts were obtained and the quality specifications were determined by evaluating three lots. The stability of the extracts was evaluated for 12 months. The genotoxic potential of the extracts was evaluated by mouse bone marrow micronucleus test and chromosome aberration test. The hypoglycemic effect was determined by oral glucose tolerance test. As results, the quality specifications were established and the aqueous extract was stable for 6 months and the hydroalcoholic extract for 12 months. A genotoxic effect was not observed in both extracts and the hypoglycemic effect was observed at the oral dose of 450 mg/kg of body weight.

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Leishmania are protozoan parasites that infect macrophages and their survival is partially achieved through inhibition of the cellular oxidative burst by parasite lipophosphoglycan (LPG). PKCalpha is the predominant PKC isoenzyme required for macrophage oxidative burst, yet it is not known if different susceptibility of BALB/c and C57BL/6 mice to Leishmania mexicana could be related to PKCalpha. We analysed the effect of L. mexicana promastigotes and parasite LPG on expression of PKCalpha and on its activity in macrophages of both mouse strains. Our data show that expression of the isoenzyme was not altered either by LPG or by L. mexicana promastigotes. Yet LPG exerted opposing effects on PKCalpha activity of macrophages between both strains: in susceptible BALB/c cells, it inhibited PKCalpha activity, whereas in the more resistant strain it augmented enzymatic activity 2.8 times. In addition, LPG inhibited oxidative burst only in susceptible BALB/c macrophages and the degree of inhibition correlated with parasite survival. Promastigotes also inhibited PKCalpha activity and oxidative burst in macrophages of BALB/c mice, whereas in C57BL/6, they enhanced PKCalpha activity and oxidative burst inhibition was less severe. Our data indicate that control of PKCalpha-induced oxidative burst by L. mexicana LPG relates with its success to infect murine macrophages.

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A new treatment regimen was tested on patients with incurable diffuse cutaneous leshmaniasis (DCL) infected with Leishmania mexicana mexicana in Mexico. Two patients with advanced stages of the disease were treated with polychemotherapy (pentamidine and allopurinol) combined with recombinant human interferon-gamma (rIFN-gamma). For determination of the best medication, parasites isolated from patient lesions were exposed to available drugs both as promastigotes and as intracellular amastigotes. A synergistic effect was observed in vitro for the combination of pentamidine and allopurinol. Both patients were treated and recovered rapidly, but one of them developed insulin-dependent type I diabetes because of pentamidine toxicity. The complication was controlled and both patients were discharged with an apparent parasitologic cure, but after 3 months the two patients began to relapse. Our results suggest that allopurinol-pentamidine polychemotherapy, involving reduced dosage of pentamidine, combined with rIFN-gamma is an alternative for DCL patients infected with L. m. mexicana.

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