Abstract The Agave genus plants represent a non-timber forest resource, valuable for soil recovery. The epidermis of the agave leaves contains multiple stomata and is covered by a cuticular layer. Currently, agave plants have a fungal disease that is characterized by circular gray spots on the maguey leaves, which over time become necrotic and eventually, these lesions end up drying them. The aim of this work was to describe the cuticular layer during the fungus colonization that causes bold in Agave salmiana subsp. salmiana. The cuticular layer is 121 mm ± 2.8 thick. A homogeneous distribution of the stomata was observed, and the density (22.67-27.67 stomata mm-2) and the stomatal index (10.61-14.15) were determined. Tetracytic stomata and isodiametric polygonal epidermal cells were identified, the ostioles size were calculated as 57.9 mm ± 5 long and 23.75 mm ± 1.25 wide. The transverse and paradermal sections showed that the fungal hyphae and appressoria are restricted from the obverse side of the cuticular layer, which confirms the importance of preserving the epidermis in the maguey pulquero leaves.

Resumen Las plantas del género Agave representan un recurso forestal no maderable valioso para la recuperación del suelo. La epidermis de sus pencas contiene múltiples estomas y está cubierta por una capa cuticular. En la actualidad presentan una enfermedad fúngica que se caracteriza por la existencia de manchas grises circulares sobre las pencas, que con el tiempo se tornan necróticas; y en ocasiones, dichas lesiones terminan por secar las pencas. El objetivo de este trabajo fue describir la relevancia de la capa cuticular durante la colonización del hongo causante de la negrilla en Agave salmiana ssp. salmiana. La capa cuticular tiene un grosor de 121 ± 2.8 mm. Se observó una distribución homogénea de los estomas y se determinó la densidad (22.67-27.67 estomas mm-2) y el índice estomático (10.61-14.15). Los estomas observados son de tipo tetracítico, el tamaño de los ostiolos de 57.9 mm ± 5 de largo y 23.75 mm ± 1.25 de ancho y células epidérmicas poligonales isodiamétricas. Los cortes transversales y paradermales muestran que las hifas y los apresorios fúngicos quedan restringidos al lado anverso de la capa cuticular, por lo cual se corrobora la importancia de conservar la epidermis en las pencas del maguey pulquero.

ABSTRACT Barley (Hordeum vulgare) is generally used for animal feed, and food and beer production industries. Its production is affected by phytopathogens, of which Ramularia collo-cygni, Puccinia spp., Pyrenophora teres and Cochliobolus sativus are of global concern. In Mexico, there are few studies available on the morphological and molecular identification of fungi responsible for causing fungal diseases of barley. Therefore, the objective of this work was to identify, morphologically and molecularly, fungi isolated from barley seeds. The strains were identified by morphological analysis and by sequencing of the conserved ITS1/5.8s/ITS2 region of the ribosomal gene. Morphologically, the strains were identified as P. teres and C. sativus, which was confirmed with bioinformatics techniques using BLAST and MEGA6 programs. The results showed that the strains isolated from barley seeds in the highlands of Mexico were consistent with the sequences of P. teres and C. sativus deposited in the GenBank. These results will allow identifying some of the species of native fungi found in barley seeds.

Resumen El objetivo del presente trabajo fue determinar el porcentaje de bovinos para abasto positivos a clorhidrato de clembuterol (CCL), con base en muestras de orina de bovinos sacrificados en 3 rastros del estado de México. Para esto se colectaron muestras en los rastros municipales de Toluca (59), Ixtlahuaca (52) y Atlacomulco (40), y se obtuvo un total de 151 muestras. El análisis de las muestras se realizó a través de la prueba de ELISA y para el reporte de resultados se utilizó estadística descriptiva. De las muestras analizadas 105 fueron positivas (69,53 %), por rastro la positividad, fue de 48, 30 y 27 respectivamente. Al establecer diferentes rangos de concentración a CCL, en el rango de 200 a 1999 pg g-1 se ubicaron 46 muestras; 6 muestras, en el rango de 2000 a 3525 pg g-1; 3, en el rango de 3526 a 5050 pg g-1; 1 muestra, entre 5051 y 6575 pg g-1, y 95 se ubicaron entre 6575 y >8100 pg g-1. El rastro con mayor porcentaje de positividad fue el de Toluca, con base en los rangos establecidos, y las concentraciones más elevadas también se observaron en el mismo rastro. El límite mínimo de detección de CCL de 2000 pg g-1 permite considerar que, con base tanto en la concentración como en su cinética, las cantidades detectadas en el estudio sirven como un indicador importante de residualidad a través de este tipo de muestra.

Abstract The present work aimed to determine the percentage of bovines that tested positive for clenbuterol hydrochloride (CCL), based on urine samples of cattle slaughtered in 3 slaughterhouses of the State of Mexico. To the effect, samples were collected in the municipal slaughterhouses of Toluca (59), Ixtlahuaca (52), and Atlacomulco (40), resulting in a total of 151 samples. Sample analysis was carried out using the ELISA test, and descriptive statistics were used to report the results. 105 of the analyzed samples were positive (69.53%); by slaughterhouse, positivity was 48, 30, and 27, respectively. When establishing different ranges of CCL concentration, 46 samples were in the range of 200 to 1999 pg g-1; 6 samples were in the range of 2000 to 3525 pg g-1; 3 were in the range of 3526 to 5050 pg g-1; 1 sample was between 5051 and 6575 pg g-1, and 95 samples were between 6575 and >8100 pg g-1. The slaughterhouse with the highest percentage of positivity was that of Toluca, based on the established ranges, and the highest concentrations were also observed there. The minimum limit for the detection of CCL (2000 pg g-1) allows considering that, based on both concentration and kinetics, the quantities detected in the study serve as an important indicator of residuality in this type of sample.

Resumo O objetivo do presente trabalho foi determinar a porcentagem de bovinos para fornecimento, positivos ao cloridrato de Clenbuterol (CCL), baseados em amostras de urina de bovinos abatidos em três trilhas do estado de México. Para isso, foram coletadas amostras nas trilhas municipais de Toluca (59), Ixtlahuaca (52) e Atlacomulco (40), e obtivera-se um total de 151 amostras. A análise das amostras realizou-se através do teste de ELISA e para o relatório de resultados foi usada estatística descritiva. Das amostras analisadas 105 foram positivas (69,53 %), pelo traço a positividade foi de 48, 30 e 27 respetivamente. Ao estabelecer diferentes faixas de concentração a CCL, 46 amostras foram colocadas na faixa de 200 a 1999 pg g-1; 6 amostras na faixa de 2000 a 3525 pg g-1; 3 na faixa de 3526 a 5050 pg g-1; 1 amostra entre 5051 e 6575 pg g-1, e 95 entre 6575 e >8100 pg g-1. A trilha com maior porcentagem de positividade foi a de Toluca, baseada nas faixas estabelecidas e as concentrações mais altas observaram-se na mesma trilha. O limite mínimo de detecção de CCL de 2000 pg g-1 permite considerar que, baseado na concentração e na cinética, as quantidades detectadas no estudo servem como indicador importante de residualidade através deste tipo de amostra.

Background : The venom of Centruroides limpidus limpidus (Cll) is a mixture of pharmacologically active principles. The most important of these are toxic proteins that interact both selectively and specifically with different cellular targets such as ion channels. Recently, anticancer properties of the venom from other scorpion species have been described. Studies in vitro have shown that scorpion venom induces cell death, inhibits proliferation and triggers the apoptotic pathway in different cancer cell lines. Herein, after treating human cervical adenocarcinoma (HeLa) cells with Cll crude venom, their cytotoxic activity and apoptosis induction were assessed. Results : Cll crude venom induced cell death in normal macrophages in a dose-dependent manner. However, through viability assays, HeLa cells showed high survival rates after exposure to Cll venom. Also, Cll venom did not induce apoptosis after performing ethidium bromide/acridine orange assays, nor was there any evidence of chromatin condensation or DNA fragmentation. Conclusions : Crude Cll venom exposure was not detrimental to HeLa cell cultures. This may be partially attributable to the absence of specific HeLa cell membrane targets for molecules present in the venom of Centruroides limpidus limpidus. Although these results might discourage additional studies exploring the potential of Cll venom to treat human papilloma cervical cancer, further research is required to explore positive effects of crude Cll venom on other cancer cell lines.