Jatropha curcas L. is native of tropical America; in our country it has mainly been used as a medicinal and food since pre-Hispanic times. Currently the oil extracted from its seeds has gained international importance as it can be transformed into biodiesel. The knowledge on the genetic variability of the species is scarce. A gene used successfully for the study of patterns of variation and origin of cassava (Manihot esculenta L.) and cocoa (Theobroma cacao L.) is the nuclear gene G3PDH (glyceraldehyde 3-phosphate dehydrogenase) involved in photosynthesis. In this paper, we used the same gene to explore its variability in J. curcas. Fifteen populations from different areas of Mexico were examined (Veracruz, Campeche, Yucatán y Quintana Roo). The gene was amplified using primers originally designed by Strand et al. (1977) to isolate around 1000 bp. Two additional internal primers designed by Olsen y Schaal (1999) were used to amplify shorter sections of 600 and 800 bp approximately. As a result a 500 bp section of the G3pdh of J. curcas L. was amplified and tested for variation at population level showing its usefulness for studies of genetic diversity and phylogeographic patterns.

Jatropha curcas L. es una especie nativa de América tropical; en nuestro país se ha venido utilizando principalmente como medicinal y alimenticia desde la época prehispánica. Actualmente el aceite extraído de sus semillas ha adquirido importancia internacional ya que puede ser transformado a biodiesel. El conocimiento que existe sobre la variabilidad genética de la especie es escaso. Un gen utilizado con éxito para el estudio de patrones de variación y origen de la yuca (Manihot esculenta L.) y del caco (Theobroma cacao L.) es el gen nuclear G3pdh (Gliceraldehído 3 fosfato deshidrogenasa) involucrado en la fotosíntesis. Con base en ello, en este trabajo se exploró la variabilidad del gen G3pdh en individuos de J. curcas provenientes de 15 poblaciones de los estados de Veracruz, Campeche, Yucatán y Quintana Roo. Para obtener el gen G3pdh completo de alrededor de 1000 pares de bases, se amplificó utilizando los primeros diseñados por Strand et al. (1997) y los dos primeros internos reverse diseñados por Olsen y Schaal (1999) para obtener segmentos más cortos, de 600 y 800 pares de bases aproximadamente. Por primera vez se amplificaron aproximadamente 500 pb y los resultados demuestran que el gen G3pdh es útil para analizar la variabilidad de J. curcas, y con un importante potencial para evaluar la distribución y evolución de sus poblaciones en México, conocer las relaciones ancestro-descendiente a nivel poblacional y explicar las causas de la distribución de los distintos haplotipos.

The porcine transmissible gastroenteritis is a highly severe contagious disease, caused by virus of the Coronaviridae family, genus Coronavirus. Its epizootic shape can reach a rate of up to 100% mortality in piglets under two weeks of age as a result of severe dehydration. In this study fragments of small intestine and stool samples were collected from 75 autopsied pigs from properties. The samples of the fragments were frozen and sent to the Laboratory of Electron Microscopy, Instituto Biológico, SP, Brazil, for histological and transmission electron microscopic analyses. According to histological H&E technique, atrophy, villous necrosis and destruction of the enterocytes were observed in 35 (46.6%) out of the 75 fragments of the small intestine samples. On the immunohistochemistry technique 19 (25.3%) fragments were positively stained with DAB in the Ag-Ac reaction (MabTGEV). In 19 (25.3%) positive samples analyzed by in situ hybridization, a brown stain of enterocytes was observed, mainly in the epithelial cells of the villi. By the negative staining technique, we visualized enveloped, pleomorphic coronavirus particles, with typical radial projections resembling solar corona, with 140 nm diameter in 21 samples (28%) of the small intestine fragments and in 16 (21.3%) stool samples. In the ultrathin sections of 21 (28%) samples of small intestine, complete coronavirus particles with 80 nm diameter were seen among the microvilli and in the cytoplasm of epithelial cells. Immature particles with 60 nm diameter, budding from cell membrane and from a rough endoplasmic reticulum and also inside the vacuoles were visualized. In 19 (25.3%) out of 75 analyzed samples of small intestine, the antigen-antibody interaction was characterized by aggregation of viral particles in the immunoelectron microscopy technique. In the immunocytochemistry technique, the antigen-antibody interaction was strongly enhanced by the dense colloidal gold particles over the coronavirus in 19 (25.3%) out of the 75 samples of fragments of small intestine examined.

La gastroenteritis transmisible porcina se caracteriza por ser una enfermedad altamente contagiosa y aguda, causada por virus de la familia Coronaviridae, género Coronavirus. Su forma epizoótica puede alcanzar una tasa de hasta 100% de mortalidad en lechones con menos de dos semanas de edad, como resultado de deshidratación severa. En este trabajo se recogieron 75 fragmentos de intestino delgado y muestras de heces de 75 cerdos autopsiados. Las muestras se congelaron y se enviaron al Laboratorio de Microscopía Electrónica, del Instituto Biológico, SP, Brasil, para el análisis histológico y por microscopía electrónica de transmisión. Por la técnica histológica de H&E fue observado atrofia y necrosis de la vellosidades además de la destrucción de los enterocitos en 35 (46,6%) de las 75 muestras de fragmentos del intestino delgado. Por inmunohistoquímica 19 (25,3%) de los fragmentos se tiñeron positivamente por el DAB en la reacción Ag-Ac (MabTGEV). En 19 (25,3%) muestras positivas mediante hibridación in situ, se observó tinción marrón de los enterocitos, principalmente en las células epiteliales de las vellosidades. Por la técnica de coloración negativa, se observaron partículas de coronavirus, encapsuladas, pleomórficas con proyecciones radiales típicas, en forma de corona solar, midiendo alrededor de 140 nm de diámetro en 21 (28%) muestras de fragmentos del intestino delgado y en 16 (21,3%) muestras de heces. En cortes ultra finos de 21 (28%) fragmentos de intestino delgado fueron visualizadas partículas de coronavirus completas con 80 nm de diámetro entre las microvellosidades y en el citoplasma de las células epiteliales y partículas inmaduras de 60 nm de diámetro brotando de las membranas celulares y del retículo endoplasmático rugoso y en el interior de las vacuolas. En 19 (25,3%) de las 75 muestras de intestino delgado, la interacción antígeno-anticuerpo se caracterizó por agregación de las partículas virales en la técnica de microscopía inmunoelectrónica. En la técnica de inmunocitoquímica, la interacción antígeno-anticuerpo fue fuertemente reforzada por las densas partículas de oro coloidal sobre el coronavirus en 19 (25,3%) de los 75 fragmentos del intestino delgado examinados.

The purpose of this study was to determine the middle latency response (MLR) characteristics (latency and amplitude) in children with (central) auditory processing disorder [(C)APD], categorized as such by their performance on the central auditory test battery, and the effects of these characteristics after auditory training. Thirty children with (C)APD, 8 to 14 years of age, were tested using the MLR-evoked potential. This group was then enrolled in an 8-week auditory training program and then retested at the completion of the program. A control group of 22 children without (C)APD, composed of relatives and acquaintances of those involved in the research, underwent the same testing at equal time intervals, but were not enrolled in the auditory training program. Before auditory training, MLR results for the (C)APD group exhibited lower C3-A1 and C3-A2 wave amplitudes in comparison to the control group [C3-A1, 0.84 µV (mean), 0.39 (SD - standard deviation) for the (C)APD group and 1.18 µV (mean), 0.65 (SD) for the control group; C3-A2, 0.69 µV (mean), 0.31 (SD) for the (C)APD group and 1.00 µV (mean), 0.46 (SD) for the control group]. After training, the MLR C3-A1 [1.59 µV (mean), 0.82 (SD)] and C3-A2 [1.24 µV (mean), 0.73 (SD)] wave amplitudes of the (C)APD group significantly increased, so that there was no longer a significant difference in MLR amplitude between (C)APD and control groups. These findings suggest progress in the use of electrophysiological measurements for the diagnosis and treatment of (C)APD.

We have already shown the presence of guanidine neurotoxins in calcareous red algae and mussels collected in the São Sebastião channel (State of São Paulo, Brazil). It is known that these neurotoxins comprise more than 25 analogues such as tetrodotoxin (TTX) and derivatives plus the paralytic shellfish toxins (PST) found in a variety of marine, freshwater and amphibious species. Filter feeding animals generally possess large amounts of these neurotoxins. The tunicates are sessil marine animals with a high rate of sea water filtration. The tunics and siphons of 50 specimens of Phallusia nigra were dissected and the visceral organs were immersed in methanol containing acetic acid 0.02 N pH 5.0. The extract was prepared by homogenization, filtration and the methanolic phase was concentrated under reduced pressure and defatted with chloroform. The polar phase was evaporated and the residue dissolved in deionized water for further purification in ionic-exchange resin column (Bio-Gel P-2) and HPLC analysis. The extract showed paralytic effects on mouse assay (26.9 MU/100mg) and on crustacean isolated nerve preparations. The chemical analysis for TTX and PST revealed toxins with retention times similar to gonyautoxins, saxitoxins and TTX. These findings are important to explain future toxin envenoming outbreaks on the Brazilian coast.