Search

The clinical and epidemiological aspects of rotavirus infection in children in Donetsk region at present stage were studied. It is found that among patients with acute intestinal infections and acute respiratory viral infections positive results of screening for rotaviruses were 39.7 and 13.0 %, indicating the general circulation and spread of rotavirus infection.

Purpose. There is a need of wear process modeling in the wheel-rail system. This is related to the fact that the wear processes in this system are absolutely different in the initial and final stages. The profile change of rail and, especially, of the wheels caused by the wear significantly affects the rolling stock dynamics, traffic safety and the resource of the wheels and rails. Wear modeling and the traffic safety evaluation requires the accounting of the low frequency component forces (including the modeling of transitional areas) affecting the wheel on the side of the rail and carriage in motion of rolling stock, so the statistical analysis is not possible. Methodology. The method of mathematical modeling of the wheel set and the rail interaction was used during the research conducting. Findings. As a result of the modeling of the wheel set motion on the rail track, the mathematic model with 19 freedom degrees was obtained. This model takes into account the axle torque and studies wheels constructions as the components of the mechanical systems, consisting of a hub and tire. Originality. The mathematic model allows evaluating the wear degree of the wheels and rails when using on the rolling stock not only all-metal wheel sets, but also compound ones with the use of spring wheels and independent rotation of semi-axes with the wheels. Practical value. The development of the improved mathematical model of freight car wheel set motion with differential rotation of the wheels and compound axles allows studying the wear processes of wheels and rails.

We estimate the derivative of a probability density function defined on [0,∞). For this purpose, we choose the class of kernel estimators with asymmetric gamma kernel functions. The use of gamma kernels is fruitful due to the fact that they are nonnegative, change their shape depending on the position on the semi-axis and possess good boundary properties for a wide class of densities. We find an optimal bandwidth of the kernel as a minimum of the mean integrated squared error by dependent data with strong mixing. This bandwidth differs from that proposed for the gamma kernel density estimation. To this end, we derive the covariance of derivatives of the density and deduce its upper bound. Finally, the obtained results are applied to the case of a first-order autoregressive process with strong mixing. The accuracy of the estimates is checked by a simulation study. The comparison of the proposed estimates based on independent and dependent data is provided.

A infecção por Brucella ovis é considerada uma das principais causas de epididimite e infertilidade em carneiros, resultando em falhas reprodutivas e perdas econômicas significativas em rebanhos ovinos ao redor do mundo. O estudo teve o objetivo de avaliar três testes sorológicos disponíveis para o diagnóstico da brucelose ovina por B. ovis, utilizando 181 soros ovinos. Amostras de soro provenientes de carneiros experimentalmente infectados foram coletadas ao longo de 192 dias pós-infecção (n=117) e durante o período pré-infecção (n=9). Adicionalmente, amostras de soro foram obtidas de ovinos provenientes de um rebanho livre para B. ovis (n=55). As técnicas de imunodifusão em gel de agar (IDGA), utilizando dois antígenos disponíveis comercialmente, e de fixação de complemento foram comparadas (FC). Foram obtidos resultados de sensibilidade especificidade semelhantes para ambos os métodos de IDGA e ainda, a técnica de IDGA foi mais eficiente do que a da FC para o diagnóstico sorológico da infecção por B. ovis.

Gastric cancer is the fourth most frequent type of cancer and the second cause of cancer mortality worldwide. The genetic alterations described so far for gastric carcinomas include amplifications and mutations of the c-ERBB2, KRAS, MET, TP53, and c-MYC genes. Chromosomal instability described for gastric cancer includes gains and losses of whole chromosomes or parts of them and these events might lead to oncogene overexpression, showing the need for a better understanding of the cytogenetic aspects of this neoplasia. Very few gastric carcinoma cell lines have been isolated. The establishment and characterization of the biological properties of gastric cancer cell lines is a powerful tool to gather information about the evolution of this malignancy, and also to test new therapeutic approaches. The present study characterized cytogenetically PG-100, the first commercially available gastric cancer cell line derived from a Brazilian patient who had a gastric adenocarcinoma, using GTG banding and fluorescent in situ hybridization to determine MYC amplification. Twenty metaphases were karyotyped; 19 (95%) of them presented chromosome 8 trisomy, where the MYC gene is located, and 17 (85%) presented a deletion in the 17p region, where the TP53 is located. These are common findings for gastric carcinomas, validating PG100 as an experimental model for this neoplasia. Eighty-six percent of 200 cells analyzed by fluorescent in situ hybridization presented MYC overexpression. Less frequent findings, such as 5p deletions and trisomy 16, open new perspectives for the study of this tumor.

Human tumor samples were screened for point mutations by adapting a mobilityshift assay to automated DNA sizing. This screen identifies the type of point mutation and relative amount of mutated DNA sequences present in a sample. Test samples having known hypoxanthine-guanine phosphoribosyl transferase (hprt)/exon-3 sequence mutations were characterized by: (i) PCR amplification, (ii) fluorescent dyeprimer extension with 36-atom linker derived deoxycytosine or deoxyuridine triphosphate and the remaining three natural nucleotides and (iii) sizing of the resulting fluorescently labeled modified strands, using an automated DNA sequencer. Routinely, a range of sizes is observed among the sequence variants of a single DNA target sequence. This is because nucleotide analogs are incorporated into DNA strands in a sequence-dependent manner, resulting in composition-dependent electrophoretic mobility. Thus, point mutations are identified as shifts in mobility between the fluorescently labeled modified strands of the control and test samples. The twenty different hprt/exon-3 single-base substitution mutations tested were easily identified, even at fourfold dilution with control DNA.

The gene technology using in plant investigations came to the better understanding of plant physiological processes. At the same time unclear knowledge about transgenic plant physiology may occur a source of incorrect interpretation of obtained results and, consequently, wrong conclusions. In addition, the causes and mechanisms of pleiotropic effects associated with transgenic insertion and gene silencing are remaining unexplained. To solve the problem of transgenic plant physiology it is necessary to pay a close attention to physiological and biochemical peculiarities of plant-agrobacterium symbiosis, because it is a base of plant transformation. It was assumed earlier that agrobacterial transformation is a complex biotic stressing factor and transgenic plant is a long-term stressed organism. We suppose that physiological consequences of plant transformation are determined not only by foreign gene insertion, but largely by stress reaction of plant cells on agrobacterium transformation. Foreign DNA insertion to the plant recipient results in cascade of response reactions remarkably changing metabolism. The degree of such response is supposed to be in dependence on phylogenetic relations of gene donor and recipient. Cell cultures were obtained from tobacco plants (Nicotiana tabacum cv. ’Samsung’) transformed by following Agrobacterium tumefaciens strains: disarmed 669 one and LBA4400 one with hsp 101 in sense or antisense orientation. These cell cultures were used for investigations of the stress-reactions on biotic (bacterial infection agent Clavibacter michiganensis subsp. Sepedonicus) and abiotic (high temperature, potassium fluoride) factors. It was revealed that “sense” culture was superior to normal and “699” ones in tolerance to pointed stressing factors. Similar results were obtained for “antisense” culture, nevertheless it was a priori not expected to be tolerant. So, to assess the transformation consequence is necessary to take into account that observed effects may not result from action of the invected gene only. Conclusions: 1. To consider the transgenesis to be completed solely if expression of transferred gene is present – is methodologically incorrect way. The transferred genes could be silenced because of the response defense reaction likely as under a “pathogen attack”. So the absence of transferred gene expression doesn’t mean the absence of transformation as fact. Moreover the deletion of inserted construction could take place but physiological trace of the insertion nevertheless can be noticeable.2. The assessment of physiological consequences of transgenesis when using the plants transformed by disarmed constructions and the plants transformed by constructions including foreign geterological genes should be carried out carefully because of these systems are different. The process of transformation by disarmed constructions is very similar with natural agrobacterial infection where plants and bacteria have been coadapted during evolution, so the transformation by insertion of foreign genes leads to forming much more unstable systems.

The age of a large Brazil-nut tree (Bertholletia excelsa) is measured by radiocarbon dating, and a discussion is made about their importance in the Amazon rain-forest ecosystem.A idade de uma castanheira (Bertholletia excelsa) grande é medida por datação radiocarbônica e uma discussão é feita a respeito de sua importância no ecosistema da floresta amazônica.

Afin d’estimer la prévalence de la brucellose chez des bufflesses (Bubalus bubalis) de la région de la vallée du Ribeira, Etat de São Paulo, Brésil, 462 animaux provenant de 16 troupeaux et localisés dans sept districts municipaux, furent examinés au moyen de la réaction de fixation du complément. Parmi les animaux examinés, 10,39 % étaient positifs et le taux de positivité de la population a varié de 7,61 à 13,17 %, avec un intervalle de confiance de 95 %. Des animaux positifs ont été trouvés dans 11 des 16 troupeaux et dans cinq des sept districts municipaux. Il n’y a pas eu de différence significative des taux de prévalence de la brucellose en prenant pour critères le type de production et le système d’élevage. Le taux de prévalence de la brucellose était significativement plus élevé (P < 0,01) chez les bufflesses ne vivant pas en commun avec d’autres bovidés (13,74 %) que chez celles qui étaient élevées avec d’autres bovidés (0,83 %). Il a aussi été observé que la prévalence de la maladie chez les animaux âgés de plus de six ans (18,63 %) était plus importante (P < 0,01) que celle des animaux de trois à six ans et de moins de trois ans (8,06 %). Les résultats indiquent que la brucellose pourrait être un problème sanitaire important pour le troupeau étudié.

The 18O content of rain and river waters was used as an isotopic tracer in order to carry out the hydrograph separation of the Amazon river, during the 1973-1974 hydrological years, and to estimate the contributions of the surface runoff (event water) and baseflow (pre-event water) components to the total river flow. The average surface runoff and baseflow contributions were 30.3 and 69.7% respectively. At peak discharge, the mean contribution of the baseflow was about 57%. The results of the isotopic separation model were compared with the filter-separation autoregressive method, showing similar behavior and magnitude.Os teores de 18O em águas de chuva e amostras de água de rio foram utilizados como traçadores num modelo isotópico de separação de hidrógrafas do rio Amazonas durante o período 1973-1974, com o intuito de se estimar as contribuições do escoamento superficial rápido e escoamento de base para o escoamento total da bacia de drenagem. As contribuições médias desses reservatórios foram de 30,3 e 69,7% respectivamente. Durante o período de pico de cheia, o fluxo de base contribuiu com cerca de 57% do volume total de água escoada. Os resultados do modelo de separação isotópico foram comparados com o método estatístico de filtros auto-recursivos, mostrando comportamentos similares.

RESUMO Um caso de abiotrofia cerebelar em um gato com 45 dias de idade foi diagnosticado no Laboratório de Patologia Animal, Hospital Veterinário da Universidade Federal de Campina Grande. O animal apresentava, havia 15 dias, apatia, anorexia, desidratação, ataxia, hipermetria, espasticidade dos membros torácicos e pélvicos, tremores de intenção, nistagmo, opistótono, déficit proprioceptivo e ausência de resposta de ameaça. Clinicamente, havia a suspeita de hipoplasia cerebelar, e, devido ao prognóstico desfavorável, o animal foi eutanasiado. Na necropsia, não foram observadas alterações macroscópicas. Microscopicamente, as lesões estavam restritas ao cerebelo e caracterizavam-se por alterações neurodegenerativas e necróticas, com desaparecimento segmentar dos neurônios de Purkinje. Nessas áreas, também se verificaram espaços em branco, denominado aspecto de cesto vazio, resultantes da perda dos neurônios de Purkinje, além de raros esferoides axonais e proliferação dos astrócitos de Bergmann. Em algumas áreas, a camada granular estava hipocelular e havia moderada gliose multifocal na camada molecular. O diagnóstico de abiotrofia cerebelar foi realizado com base nos dados epidemiológicos, clínicos e, principalmente, pelas alterações histopatológicas dos neurônios de Purkinje características da doença.

ABSTRACT We report a case of intestinal intussusception secondary to enteritis caused by Pythium insidiosum infection in a 1-year-old mixed breed bitch that died after a 30-day history of bloody diarrhea, anorexia, weight loss, listlessness, dehydration, and pale mucous membranes. Necropsy revealed two areas of intussusception, one jejunum-jejunal and one ileum-cecum-colic. The first intussusception showed slight congestion of the intestinal loop, which was resolved by manual traction, while the second intussusception exhibited thickening, irregular yellow spots, and transmural congestion. Histologically, the jejunum-jejunal segment had ischemic lesions secondary and ileum-cecum-colic intussusception there was also necrotizing, pyogranulomatous enteritis associated with negative images of intralesional fungal hyphae that were well visualized by silver impregnation. Immunohistochemistry identified the hyphae as Pythium insidiosum. The diagnosis was made based on the histological changes and confirmed by immunohistochemistry. We can conclude that enteritis by P. insidiosum in dogs can occasionally cause intestinal intussusception and result in acute death.

RESUMO Relata-se um caso de lesão cutânea secundária à infecção por Corynebacterium pseudotuberculosis em bovino. Abscessos e múltiplas lesões cutâneas nodulares, variando de 8x10 para 20x25cm de diâmetro, firmes, sensíveis ao toque e sem mobilidade, algumas com superfície ulcerada, circundada por halo avermelhado e drenando secreção piossanguinolenta, e outras com superfícies alopécicas, foram identificados na região torácica lateral do animal. Exames histopatológicos e o isolamento do agente de fragmentos obtidos após remoção cirúrgica das lesões confirmaram tratar-se da forma cutânea da infecção pelo C. pseudotuberculosis. As lesões microscópicas caracterizaram-se por dermatite nodular piogranulomatosa e ulcerativa. A avaliação da susceptibilidade in vitro do C. pseudotuberculosis a antimicrobianos demonstrou que o agente era resistente à amicacina, kanamicina, neomicina e penicilina G, apresentando sensibilidade à ampicilina adicionada de subactam, amoxicilia com ácido clavulônico, cefalexina, cefalotina, cefotaxima, enrofloxacina, gentamicina e tetraciclina. A retirada cirúrgica das lesões e o tratamento com enrofloxacina resultaram na cura do animal. Lesões de pele observadas em casos de ptiose, carcinoma de células escamosas e na forma atípica da actinobacilose devem ser consideradas no diagnóstico diferencial da forma cutânea da infecção por C. pseudotuberculosis em bovinos. Os dados apresentados demonstram que a infecção pelo C. pseudotuberculosis deve ser considerada no diagnóstico diferencial das lesões de pele em bovinos no Brasil.

ABSTRACT The objective of work was to study the productive profile of perennial peanut in a rotational stocking environment under different criteria. The treatments corresponded to pre-grazing height of 14 and 18cm or 95% of light interception (LI) distributed in a completely randomized design. The studied variables were forage mass, percentage of structural components, forage mass and the structural components in the lower and upper canopy strata. The entrance criterion of 18cm in height, despite having higher forage mass, presented lower percentage of leaves and higher percentage of stems and forage losses. The criteria of 14cm and 95% light interception presented similar production between them and the highest rate of forage accumulation. In all criteria, in the upper strata of pasture a higher percentage of leaves were found. The criteria of 95% LI and 14cm in height presented the best productive performances. The entry criterion of 18cm presented a higher mass of pre-grazing forage with lower percentage of dead material, but with higher forage losses, resulting from senescent leaves. Due to changes in the structural components, as grazing cycles increase, the interception of 95% of the incident light by the perennial peanut occurs at lower heights.