Characteristics of Yersinia pseudotuberculosis isolated from animals in Brazil

Strains (105) of Yersinia pseudotuberculosis isolated in Brazil between 1982 and 1990 mere bio-serotyped. They were also studied for plasmid profile, autoagglutination and calcium dependence at 37 degrees C, Congo red uptake, pyrazinamidase activity, esculin hydrolysis, salicin fermentation and drug sensitivity: 95.24% were biotype 2, serogroup O:3; 2.86% were biotype 1, serogroup O:1; and 1.90% were biotype 2, non-agglutinable. Plasmids were found in 77.14% of the strains (one in each strain). There was total correlation between the presence of the virulence plasmid and autoagglutination, calcium dependence at 37 degrees C and Congo red uptake. The esculin, salicin and pyrazinamidase tests were not efficient in differentiating pathogenic from non-pathogenic Y, pseudotuberculosis isolates. All strains were highly sensitive to the drugs used. These results indicate that Y. pseudotuberculosis is a potential pathogen for humans in Brazil, especially because the bio-serogroups detected among animals are those most frequently associated with human diseases.

Experimental study of progressive facial hemiatrophy: effects of cervical sympathectomy in animals

Progressive facial hemiatrophy (Romberg's syndrome) is of unknown cause and uncertain pathogenesis. The main pathogenetic hypotheses are: sympathetic system alterations, localized scleroderma, trigeminal changes, possibly of genetic origin. To test the hypothesis of sympathetic system alterations, we designed an experimental model with ablation of the superior cervical sympathetic ganglion in rabbits, cats and dogs. All the animals were operated upon when 30 days old and were examined monthly for 1 year. During this period localized alopecia, corneal ulceration, keratitis, strabismus, enophthalmos, ocular atrophy, hemifacial atrophy and slight bone atrophy on the side of the sympathectomy were observed. Thus, cervical sympathectomy reproduces in animals the principal clinical alterations of Romberg's syndrome. Our data suggest that the sympathetic system is involved in the pathogenesis of this syndrome.

Radiative properties of the skin and haircoat of cattle and other animals

Radiative properties (reflectance rho, transmittance tau, and absorptance alpha) were determined for wavelengths from 300 to 850 nm in the haircoat and the skin of water buffalo, deer (Pantanal deer, Blastocerus dichotomus), and cattle of the Holstein, Simmental, Canchim, Brangus, and Nelore breeds. The results showed that white hairs have higher rho (0.60 to 0.67) than the other coat colors, but the gray coats (mixed white and dark hair) of the Nelore cattle presented higher rho than that of the white coats of the European breeds at wavelengths lower than 600 nm. The light gray colored skin of the Canchim cattle had higher rho (0. 66) than the non-pigmented skin of Holstein (0.53). Red skins presented rho values higher than those of dark gray and black skins. Buffalo skin (dark gray) presented an average rho of 0.23+/-0.02 and alpha of 0.77+/-0.02. The red haircoat of the deer presented rho lower (0.37) than that of cattle of the same color (0.58). However, there was little difference between deer and cattle with respect to reflectance and absorptance of the skin. As for the spectral transmittance of the skin, it was very low and about the same for both species, until 600 nm. In the range 600 to 850 nm, the tau values for cattle rose to 0. 17, while those for deer increased only to 0.12.

Use of Aspiration Method for Collecting Brain Samples for Rabies Diagnosis in Small Wild Animals

P>In developing countries such as Brazil, where canine rabies is still a considerable problem, samples from wildlife species are infrequently collected and submitted for screening for rabies. A collaborative study was established involving environmental biologists and veterinarians for rabies epidemiological research in a specific ecological area located at the São Paulo State, Brazil. The wild animals' brains are required to be collected without skull damage because the skull's measurements are important in the identification of the captured animal species. For this purpose, samples from bats and small mammals were collected using an aspiration method by inserting a plastic pipette into the brain through the magnum foramen. While there is a progressive increase in the use of the plastic pipette technique in various studies undertaken, it is also appreciated that this method could foster collaborative research between wildlife scientists and rabies epidemiologists thus improving rabies surveillance.

Gene expression in placentation of farm animals: An overview of gene function during development

Eutherian mammals share a common ancestor that evolved into two main placental types, i.e., hemotrophic (e.g., human and mouse) and histiotrophic (e.g., farm animals), which differ in invasiveness. Pregnancies initiated with assisted reproductive techniques (ART) in farm animals are at increased risk of failure; these losses were associated with placental defects, perhaps due to altered gene expression. Developmentally regulated genes in the placenta seem highly phylogenetically conserved, whereas those expressed later in pregnancy are more species-specific. To elucidate differences between hemotrophic and epitheliochorial placentae, gene expression data were compiled from microarray studies of bovine placental tissues at various stages of pregnancy. Moreover, an in silico subtractive library was constructed based on homology of bovine genes to the database of zebrafish - a nonplacental vertebrate. In addition, the list of placental preferentially expressed genes for the human and mouse were collected using bioinformatics tools (Tissue-specific Gene Expression and Regulation [TiGER] - for humans, and tissue-specific genes database (TiSGeD) - for mice and humans). Humans, mice, and cattle shared 93 genes expressed in their placentae. Most of these were related to immune function (based on analysis of gene ontology). Cattle and women shared expression of 23 genes, mostly related to hormonal activity, whereas mice and women shared 16 genes (primarily sexual differentiation and glycoprotein biology). Because the number of genes expressed by the placentae of both cattle and mice were similar (based on cluster analysis), we concluded that both cattle and mice were suitable models to study the biology of the human placenta. (C) 2011 Elsevier B.V. All rights reserved.

Polybitoxins: A group of phospholipases A2 from the venom of the neotropical social wasp paulistinha (Polybia paulista)

The neotropical wasp Polybia paulista is very aggressive and endemic in south-east Brazil, where it frequently causes stinging accidents. By using gel filtration on Sephadex G-200, followed by ion-exchange chromatography on DEAE-Cellulose under a pH gradient, a group of four toxins (designated as polybitoxins-I, II, lII and IV) presenting phospholipase A2 (PLA2) activities was purified. These toxins are dimeric with mol. wts ranging from 115,000 to 132,000 and formed by different subunits. The four toxins contain very high sugar contents attached to their molecules (22-43% w/w) and presented different values of pH optimum from 7.8 to 9.0; when dissociated, only residual catalytic activities were maintained. The catalytic activities of polybitoxins (from 18 to 771 μmoles/mg per minute) are lower than that of PLA2 from Apis mellifera venom and hornetin from Vespa basalis. The polybitoxins presented a non-linear steady-state kinetic behavior for the hydrolysis of phosphatidylcholine at pH 7.9, compatible with the negative co- operativity phenomena. All of the polybitoxins were very potent direct hemolysins, especially the polybitoxins-III and IV, which are as potent as the lethal toxin from V. basalis and hornetin from Vespa flavitarsus, respectively; polybitoxin-IV presented hemolytic action 20 times higher than that of PLA2 from A. mellifera, 17 times higher than that of neutral PLA2 from Naja nigricolis and about 37 times higher than that of cardiotoxin from Naja naja atra venom.

Ticks (Acari: Ixodidae) associated with wild animals in the Pantanal region of Brazil

This paper describes the identification of ticks from wild animals of the Pantanal region in Brazil as part of a comprehensive study about established and emerging tick-host relationships and related pathological aspects. Eighty-one animals were captured (representing 13 species six orders), and ticks were found on 63 (78%). Tick species identified included Boophilus microplus (Canestrini), Amblyomma cajennense (F.), Amblyomma parvum Aragão, Amblyomma pseudoconcolor Aragão, Amblyomma scalpturatum Neumann, Amblyomma nodosum Neumann, Amblyomma ovale Koch, and Amblyomma tigrinum Koch. Dragging from grasslands yielded negative results compared with the high concentration of ticks that were collected from leaves in the forests.

Ticks associated with wild animals in the Nhecolândia Pantanal, Brazil

A study of ticks associated with wild animals was carried out from September 1996 to April 1998 at the Fazenda Alegria (21,000 ha), in the Nhecolândia Pantanal, State of Mato Grosso do Sul, Brazil, a sunken plain bordering the upper Paraguay river, located 19 × 08′S; 56 × 46′W. A total of 81 wild animals (13 species, 6 orders) were captured with the aid of nets, and ticks were found on 63 (78%). Tick species identified included Boophilus microplus (Canestrini), Amblyomma cajennense (F.), A. parvum (Aragão), A. pseudo-concolor (Aragão), A. scalpturatum (Neumann), A. nodosum (Neumann), A. ovale (Koch), and A. tigrinum (Koch). Dragging from grasslands (campos) yielded negative results compared to the high concentration of ticks, mainly nymphs, that were collected from leaves in the forests (capão). Predominance of immature instars (Amblyomma genera) was observed in the end of winter (August-September). Ticks were associated mainly with coatis, deer (Mazama gouazoubira) and anteater, and these animals may play a role in the epidemiology of tick-transmitted pathogens in the Pantanal if one considers their coexistence with local domestic animals.

A review of antifertility folkloric plants tested in laboratory animals

The use of natural active principals is widespread among a great proportion of the rural population, or by people who do not have easy access to medical assistance. These active principles are used as food or medicines, and even for purposes of contraception. It becomes necessary to establish a relationship between the folklore habits and current information on the nature of anti-fertility substances, and knowledge of their mechanisms. Anti-fertility agents may exert their actions in a number of areas, (hypothalamus, anterior pituitary, oviduct, uterus, and vagina), inhibiting synthesis and/or liberation of hormones (follicle-stimulating, luteinizing, and steroid hormones), ovulation, ovum transportation, and implantation process. Therefore, a review of literature was carried out, including of several plants used by women as abortifacient and anti-fertility agents to compare their effects with those obtained among laboratory animals.