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Polledness has been shown to have autosomal Mendelian inheritance, with the polled locus being dominant to the horned locus. This trait was mapped to the BTA1 centromeric end in several breeds. One of the distinctive attributes of Creole cattle, such as the Argentinean Creole, is the presence of long, lyre-shaped horns. However, polled native animals were reported before the introduction of modern selected European breeds. Here, we studied the origin of the polled mutation, either independent or introgressed, in a Creole line from the Creole cattle founder group at the IIACS-INTA Leales Experimental Station (northwest Argentina). The study sample (65 animals: 26 horned and 39 polled) was genotyped using high-density SNP microarrays and three previously reported genetic markers (P202 ID , P80kb ID and PG ). A genome-wide association study, selection signatures, linkage disequilibrium analysis and copy number variations were used to detect the responsible region and the segregating haplotypes/alleles. The interval mapped in the Leales herd (1.23-2.13 Mb) overlapped with the region previously reported in several European cattle breeds, suggesting that the same locus could be segregating in this population. The previously reported variants PF and PG were not detected, thus dismissing the Holstein-Friesian and Nellore origins of the polled phenotype in this native breed. Conversely, the presence of the Celtic variant PC suggests an almost complete co-segregation. The cluster analysis rejected the hypothesis of recent introgression, which is compatible with the historical record of polled Creole cattle in northwest Argentina.

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Llamamos signo de los vasos gemelos la identificación con procedimientos de imagen de la vena ácigos y la aorta con diámetro similar, una al lado de la otra. Este fenómeno se debe a la gran dilatación de la vena ácigos en caso de interrupción de la vena cava.

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The insect visitors of flowers in nine weeds species were studied in the Botanical Garden of Santiago de Cuba, Eastern Cuba, during 1993 (March-June, spring season) and 1994 (January-March, end of winter and beginning of spring season). About 50 hours of collecting efforts were made at three times (0900-0930 hr in 1993; 0900-0930 hr, 1200-1230 hr and 1500-1530 hr in 1994). More than 140 species of at least 37 families were found; Hymenoptera dominated (with more than a half of specimens), followed by Diptera, Coleoptera and Lepidoptera. Among Hymenoptera, bees (Apoidea) were the largest group, especially Apis mellifera L; followed by wasps (Vespidae, Pompilidae, Sphecidae) and ichneumon flies (Ichneumonidae); Microhymenopterans were not sampled. Hymenopterans of each weed were compared for diversity, similarity, dominant and subdominant species, visitation time, sampling efficiency, etc. Each plant species had a particular Hymenoptera complex, almost one third of which were natural enemies of agricultural pests, and most are believed to be potential pollinators. Closely related species showed similar patterns of daily activity, with a peak at 0900-0930 hr for all plant species. Second grade polynomial equations were the best fitted models to describe the relationships between number of species and number of specimens, and between total number of species and number of samples (R2 = 0.9734 and R2 = 0.9573, p < 0.01). The role of weeds in the biodiversity of the agroecosystems is analyzed; as well as the effectiveness of this collection method to study Hymenoptera.

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The insect visitors of flowers in nine weeds species were studied in the Botanical Garden of Santiago de Cuba, Eastern Cuba, during 1993 (March-June, spring season) and 1994 (January-March, end of winter and beginning of spring season). About 50 hours of collecting efforts were made at three times (0900-0930 hr in 1993; 0900-0930 hr, 1200-1230 hr and 1500-1530 hr in 1994). More than 140 species of at least 37 families were found; Hymenoptera dominated (with more than a half of specimens), followed by Diptera, Coleoptera and Lepidoptera. Among Hymenoptera, bees (Apoidea) were the largest group, especially Apis mellifera L; followed by wasps (Vespidae, Pompilidae, Sphecidae) and ichneumon flies (Ichneumonidae); Microhymenopterans were not sampled. Hymenopterans of each weed were compared for diversity, similarity, dominant and subdominant species, visitation time, sampling efficiency, etc. Each plant species had a particular Hymenoptera complex, almost one third of which were natural enemies of agricultural pests, and most are believed to be potential pollinators. Closely related species showed similar patterns of daily activity, with a peak at 0900-0930 hr for all plant species. Second grade polynomial equations were the best fitted models to describe the relationships between number of species and number of specimens, and between total number of species and number of samples (R2 = 0.9734 and R2 = 0.9573, p < 0.01). The role of weeds in the biodiversity of the agroecosystems is analyzed; as well as the effectiveness of this collection method to study Hymenoptera.

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We identified a gap junction protein subunit, connexin43 (Cx43) by immunofluorescence and immunoblotting, in cultured rat carotid body cells and in whole organs. In 1-week-old cultures, all cells were flat but after 3 h exposure to 8Br-cAMP (1 mM), tyrosine hydroxylase (TH) positive cells (chemoreceptors), but not TH negative cells, adopted a round body with multiple thin arborization processes. The incidence of dye coupling between cultured cells of the same type increased from 26% in controls to 73% after treatment with 8Br-cAMP. In control cultures, Cx43 immunoreactivity showed a diffuse perinuclear distribution and after 8Br-cAMP treatment, it was also found at cell-cell contacts. Both 8Br-cAMP-induced dye coupling and cellular redistribution of Cx43 were blocked by pretreatment with actinomycin D (5 microM), a mRNA transcription blocker. Moreover, 3 h exposure to 8Br-cAMP increased the levels of Cx43 in entire organs. We suggest that conditions that promote a sustained increase in cytosolic cAMP up-regulate coupling between carotid body cells in a transcription-dependent manner. The possible functional significance of these findings is discussed.

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Se reporta un caso de tumor de Frantz (neoplasia papilar quistica del pácnreas), en una mujer de 23 años, a quien se laparotomizó encontrándo un tumor del cuerpo y cola pancreatica, con gran invasión local, no así linfática. Describimos la clínica, histológía e imagen de esta neoplasia, como el esfuerzo quirurgico del grupo de cirujanos, Logrando la radicalidad del tumor, ofreciendo de esta manera, a una pacientes jóven escelente sobrevida.

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An immunocytochemical study focused on the cellular localization of tissue kallikrein along the human and guinea-pig respiratory tracts is reported. A strong immunoreactivity for tissue kallikrein was observed in the seromucous glands of the nasal mucosa, trachea, and bronchi. In these glands, the immunostaining was restricted to the serous component of the acinus whereas mucous cells showed no staining. Since no immunoreactivity to kininogen was observed in any of the tissue constituents of the human and guinea-pig respiratory tree, transudation of the substrate from plasma was considered to be the preferred mode of delivery of the kininogen into the bronchopulmonary interstitium and lumen. Our results provide morphological evidence for the well documented presence of tissue kallikrein in bronchial lavage fluids and support the hypothesis that kinins may be one of the more important mediators involved during acute episodes of asthma and rhinitis.

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Twenty-five children with serious Gram-negative infections were treated in a prospective study with amikacin 20 mg/kg administered in a single daily dose as a 30 min iv infusion for 4 to 12 days. In nine cases the amikacin was combined with beta-lactam antibiotics. Escherichia coli were the most frequent bacteria isolated followed by K. pneumoniae, Providencia and Enterobacter spp. and Pseudomonas aeruginosa with MICs ranging from 1 to 16 mg/l. Mean (+/- S.D.) peak and trough concentrations of days 1 and 4 of therapy ranged from 49 +/- 13.5 to 53.6 +/- 13.4 mg/l and 6 + 1.4 to 7.7 +/- 4.1 mg/l respectively. All patients were clinically and bacteriologically cured. No significant adverse reactions were observed. The results suggest that administration of a single daily dose of 20 mg/kg amikacin should be considered practical and safe in children. Further studies are needed.

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El benfluorex, un hipolipemiante ampliamente conocido, ha demostrado, mediante un estudio abierto en una muestra ecuatoriana, sus propiedades al hacer descender los niveles de colesterol total, triglicéridos y LDL-C en forma significativa e incrementar los niveles del HDL-C también significativamente. Todo esto redunda en la disminución del riesgo aterosclerótico

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