Spatial distribution of Brazilian bovine taurine breeds associated with climatic, physical and socioeconomic variables / [Distribuição espacial de raças taurinas bovinas brasileiras associada a variáveis climáticas, físicas e socioeconômicas]

The objective of this study was to evaluate the spatial distribution of purebred Bos taurus taurus bovine breeds raised in Brazil in association with climatic, physical and socioeconomic variables. The breeds Aberdeen Angus, Ayrshire, Braford, Brangus, Charolais, Devon, Flemish, Hereford, Pinzgauer, Shorthorn and Simental were classified according to their aptitude (milk, meat or dual-purpose). They were spatialized according to their aptitude using state and municipal information. The milk breeds were found in the states of Rio Grande do Sul and Santa Catarina, while the dual-purpose breeds were found in Minas Gerais and Rio Grande do Sul states and the beef breeds were concentrated in the southern region. Only the Aberdeen Angus meat breed showed higher dispersion in other regions. Meat and dual-purpose breeds tended to be raised in regions with lower maximum temperature, average temperature, thermal amplitude and temperature-humidity index. Dual-purpose breeds were found in municipalities with high humidity and altitude, but with a low gross domestic product, little technical guidance received from cooperatives and the government, low control of diseases and parasites, as well as low use of pasture rotation systems. The spatial distribution of Brazilian bovine taurine breeds, regardless of aptitude, was related to climatic, physical and socioeconomic factors.(AU)

O objetivo deste estudo foi avaliar a distribuição espacial de raças bovinas puras Bos taurus taurus criadas no Brasil, associadas a variáveis climáticas, físicas e socioeconômicas. As raças Aberdeen Angus, Ayrshire, Braford, Brangus, Charolês, Devon, Flamenga, Hereford, Pinzgauer, Shorthorn e Simental foram classificadas de acordo com sua aptidão (leite, carne ou duplo-propósito). Elas foram espacializadas de acordo com sua aptidão a partir de informações estaduais e municipais. As raças leiteiras foram encontradas nos estados do Rio Grande do Sul e de Santa Catarina, enquanto as raças de duplo-propósito foram encontradas nos estados de Minas Gerais e Rio Grande do Sul, e as raças de carne concentraram-se na região Sul. Apenas a raça de carne Aberdeen Angus apresentou maior dispersão nas demais regiões. As raças de carne e de duplo-propósito tendem a ser criadas em regiões com menores temperatura máxima, temperatura média, amplitude térmica e índice de temperatura e umidade. As raças de duplo-propósito foram encontradas em municípios com alta umidade e altitude, mas com baixo produto interno bruto, pouca orientação técnica recebida de cooperativas e do governo, baixo controle de doenças e de parasitas e baixo uso de sistema de rotação de pastagens. A distribuição espacial das raças taurinas bovinas brasileiras, independentemente da aptidão, foi relacionada a fatores climáticos, físicos e socioeconômicos.(AU)

Development of an in vitro system to study the developmental stages of Toxoplasma gondii using a genetically modified strain expressing markers for tachyzoites and bradyzoites.

Toxoplasma gondii, the agent of toxoplasmosis, is an intracellular parasite that can infect a wide range of vertebrate hosts. Toxoplasmosis causes severe damage to immunocompromised hosts and its treatment is mainly based on the combination of pyrimethamine and sulfadiazine, which causes relevant side effects primarily observed in AIDS patients, including bone marrow suppression and hematological toxicity (pyrimethamine) and/or hypersensitivity and allergic skin reactions (sulfadiazine). Thus, it is important to investigate new compounds against T. gondii, particularly those that may act on bradyzoites, which are present in cysts during the chronic disease phase. We propose an in vitro model to simultaneously study new candidate compounds against the two main causative stages of Toxoplasma infection in humans, using the EGS-DC strain that was modified from a type I/III strain (EGS), isolated from a case of human congenital toxoplasmosis in Brazil and engineered to express markers for both stages of development. One feature of this strain is that it presents tachyzoite and bradyzoite in the same culture system and in the same host cell under normal culture conditions. Additionally, this strain presents stage-specific fluorescent protein expression, allowing for easy identification of both stages, thus making this strain useful in different studies. HFF cells were infected and after 4 and 7 days post infection the cells were treated with 10 µM of pyrimethamine or atovaquone, for 48 or 72 h. We used high-throughput screening to quantify the extent of parasite infection. Despite a reduction in tachyzoite infection caused by both treatments, the atovaquone treatment reduced the bradyzoite infection while the pyrimethamine one increased it. Ultrastructural analysis showed that after treatment with both drugs, parasites displayed altered mitochondria. Fluorescence microscopy of cells labeled with MitoTracker CMXRos showed that the cysts present inside the cells lost their mitochondrial membrane potential. Our results indicate that this experimental model is adequate to simultaneously analyze new active compounds against tachyzoite and bradyzoite forms.

In vitro treatment of Toxoplasma gondii with copper(II) complexes induces apoptosis-like and cellular division alterations.

Toxoplasma gondii is the causative agent of toxoplasmosis, which is one of the most common parasitic diseases in the world. This pathogen causes severe damage to immunocompromised hosts, and the most frequently used therapy is the combination of pyrimethamine and sulfadiazine, which has side effects. Thus, there is a need for new therapies that target T. gondii. Herein, we present the anti-Toxoplasma effect of two new copper(II) complexes: [(H2L1) Cu (µ-Cl)2 Cu(H2L1)] Cl2·5H2O (1) and [(H2L2) Cu (µ-Cl)2 Cu(H2L2)] Cl2·6H2O (2). Complexes (1) and (2) irreversibly controlled parasite growth in vitro, with IC50 values of 0.78µM and 3.57µM, respectively, after 48h. These complexes induced part of the tachyzoite population to convert to bradyzoites, which eventually die. The cell death mechanism was unknown, but signs of apoptosis, such as membrane blebs and nuclear fragmentation, and necrosis, such as plasma membrane disruption, intense cytoplasm vesiculation and the release of cellular contents, were seen. In addition, complex (2) interfered with the correct disposition of the inner membrane complex of the parasite, affecting cell division. These results indicate that these copper complexes have potential effects against T. gondii and may be used as drugs in the future or serve as prototypes for the development of new drugs to treat toxoplasmosis.

Reduction of Toxoplasma gondii Development Due to Inhibition of Parasite Antioxidant Enzymes by a Dinuclear Iron(III) Compound.

Toxoplasma gondii, the causative agent of toxoplasmosis, is an obligate intracellular protozoan that can infect a wide range of vertebrate cells. Here, we describe the cytotoxic effects of the dinuclear iron compound [Fe(HPCINOL)(SO4)]2-µ-oxo, in which HPCINOL is the ligand 1-(bis-pyridin-2-ylmethyl-amino)-3-chloropropan-2-ol, on T. gondii infecting LLC-MK2 host cells. This compound was not toxic to LLC-MK2 cells at concentrations of up to 200 µM but was very active against the parasite, with a 50% inhibitory concentration (IC50) of 3.6 µM after 48 h of treatment. Cyst formation was observed after treatment, as indicated by the appearance of a cyst wall, Dolichos biflorus lectin staining, and scanning and transmission electron microscopy characteristics. Ultrastructural changes were also seen in T. gondii, including membrane blebs and clefts in the cytoplasm, with inclusions similar to amylopectin granules, which are typically found in bradyzoites. An analysis of the cell death pathways in the parasite revealed that the compound caused a combination of apoptosis and autophagy. Fluorescence assays demonstrated that the redox environment in the LLC-MK2 cells becomes oxidant in the presence of the iron compound. Furthermore, a reduction in superoxide dismutase and catalase activities in the treated parasites and the presence of reactive oxygen species within the parasitophorous vacuoles were observed, indicating an impaired protozoan response against these radicals. These findings suggest that this compound disturbs the redox equilibrium of T. gondii, inducing cystogenesis and parasite death.

Mindoro blindness from corneal degeneration

The Mindoro corneal blindness is a difficult ophthalmological problem in the Philippines. It is degenerative in nature and familial in tendency, with heredity, nutrition and trauma as probable additional factors. There are no evidences to consider it a part of a dermatological, so-called "lapnus syndrome," and there are insufficient findings to incriminate stored rice as the sole cause of it. It is certainly not due to ariboflavinosis. A small, 6.5 mm., central penetrating corneal transplant may remain transparent for many years in the early cases. For moderately advanced cases, it seems to be the first choice, but for the advanced cases, a wide, 9 mm. or more, penetrating keratoplasty, has been followed by opacification of the graft after about a month. A preliminary wide anterior lamellar grafting needs further trial for those advanced casesThe pathologic picture of degenerative keratopathy may be distinct and pure in the beginning but as the lesion advances, those of inflammation, proliferation, death and even necrosis may appear probably because of biological chain reactionsThe pathogenesis of degenerative keratopathies is probably a disturbance or a defect in one or more parts of the metabolic mechanism which interferes with one or more events in metabolismThe etiology of degenerative keratopathies is often multiple and varies with race, heredity, geography, nutrition and other factorsDegenerative keratopathies should be studied along cellular and non-cellular aspects. (Conclusions)