3,005 research outputs found
Corpectomia vertebral cervical como uma técnica de descompressão medular em cães: estudo em cadáveres após o descongelamento
Este trabalho tem como objetivo relatar as implicações da técnica cirúrgica de corpectomia vertebral cervical no diâmetro do canal medular de cadáveres caninos anteriormente congelados através da avaliação mielográfica. Para a padronização da técnica de mielografia cervical foram utilizados 30 cadáveres de cães. Os espécimes foram submetidos a quatro posicionamentos radiográficos para avaliação conjunta: laterolateral neutro, laterolateral em hiperextensão, laterolateral em hiperflexão e ventrodorsal. A opacificação do espaço subaracnóide, a confecção de duas linhas de contraste e a formação de artefatos foram mensurados qualitativamente e depois seu grau de concordância foi avaliado. Na segunda etapa 20 cadáveres foram divididos em dois grupos: o primeiro grupo foi submetido à corpectomia da terceira vértebra cervical, enquanto o segundo grupo à corpectomia da quinta vértebra cervical. Previamente ao procedimento cirúrgico, os cadáveres foram submetidos a um exame mielográfico. Posteriormente foram realizados exames radiográficos seriados após o procedimento de corpectomia cervical e de estabilização vertebral. As projeções radiográficas utilizadas foram as mesmas supracitadas. O diâmetro da medula espinhal foi medido ao longo do canal medular e correlacionado com o comprimento do assoalho vertebral. A corpectomia e a estabilização vertebral alteraram significativamente o diâmetro do canal medular apenas em posições de estresse, permitindo supor que a corpectomia vertebral cervical é um método viável de descompressão medular para a região cervical em cães, proporcionando um acesso adequado ao canal medular do corpo vertebral com mínima manipulação do tecido nervoso.The aim of this paper is to report the implication of the cervical vertebral corpectomy in the myelography medullary diameter in canine cadavers. In order to standardize the myelograph technique thirty canine bodies were used. The subaracnoid space opacification, the visualization of contrast columns and artifact formation were evaluated in four radiographic projections: laterolateral in neutral position, laterolateral in hyperflexion, laterolateral in hyperextension and ventrodorsal in neutral position. The agreeing ratio was measured. Thereafter, twenty specimens were divided in two groups according to the cervical vertebra in which the procedure would be performed. In the first group the corpectomy was performed in the third cervical vertebrae and in the second group in the fifth vertebrae. Before the surgical procedure, a myelogram was performed. Radiograph exams were done after the corpectomy and after the instrumentation of the cervical spine. The same projections previously described were used. The medullary diameter was measured through the spinal canal. Afterwards, it was correlated to the length of the vertebral floor. The corpectomy and cervical instrumentation changed the medullar diameter solely in stress positions. In addition, it granted proper vertebral channel access with minimal spinal cord manipulation. Therefore, we concluded that the cervical vertebral corpectomy is a viable decompressive surgical technique
Oxidative Stress Is Associated with Overgrowth in Drosophila l(3)mbt Mutant Imaginal Discs
The loss-of-function conditions for an l(3)malignant brain tumour (l(3)mbt) in larvae reared at 29 degrees C results in malignant brain tumours and hyperplastic imaginal discs. Unlike the former that have been extensively characterised, little is known about the latter. Here we report the results of a study of the hyperplastic l(3)mbt mutant wing imaginal discs. We identify the l(3)mbt wing disc tumour transcriptome and find it to include genes involved in reactive oxygen species (ROS) metabolism. Furthermore, we show the presence of oxidative stress in l(3)mbt hyperplastic discs, even in apoptosis-blocked conditions, but not in l(3)mbt brain tumours. We also find that chemically blocking oxidative stress in l(3)mbt wing discs reduces the incidence of wing disc overgrowths. Our results reveal the involvement of oxidative stress in l(3)mbt wing discs hyperplastic growth
Luminescence properties and ROS generation of magnetic porous silicon nanoparticles
Magnetite‒Porous Silicon 100−150 nm size nanoparticles (MPSi) were obtained combining luminescent and magnetic properties from silicon and magnetite, respectively. MPSi hybrids were characterized by high-resolution transmission electron microscopy, atomic and magnetic force microscopy and X-ray photoelectron spectroscopy. The presence of magnetite quenches statically visible luminescence of Porous Silicon toluene suspensions. Whereas MPSi, maintain the luminescence in the 300−450 nm spectral region. Particles retained the capacity for singlet oxygen and superoxide radical ion generation (Reactive Oxygen Species, ROS). However quantum yield singlet oxygen generation is much lower than the PSi analogues and superoxide radical ion concentration dismiss when magnetite is incorporated in the PSi matrix. Silanization of Porous Silicon and MPSi yield nanoparticles with − SH terminal groups with unique luminescence properties.Fil: Caregnato, Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: David Gara, Pedro Maximiliano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Ópticas. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigaciones Ópticas. Universidad Nacional de La Plata. Centro de Investigaciones Ópticas; ArgentinaFil: Prieto, Eduardo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Gonzalez, Monica Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentin
ANTIBIOTICOTERAPIA NO TRATAMENTO DE INFECÇÕES BACTERIANAS DO SISTEMA NERVOSO CENTRAL DE PEQUENOS ANIMAIS
Although infections in the central nervous system are less common than infections in other organics systems, they can cause life-threatening consequences and are a challenge for small animal practitioners. Among the factors that make these infections difficult to treat are the fact that it is surrounded by the blood-brain barrier, that hinders penetration of many substances, and the difficulty of obtaining positive results when trying to isolate the causative agent through spinal tap. This article aims to describe the blood-brain barrier, the most common antimicrobials used to treat bacterial infections in the central nervous system and their main applications in small animal practice. In the veterinary literature, trimethoprim, sulfonamides, chloramphenicol, and metronidazole are cited as antimicrobials with excellent penetration on the blood-brain barrier; oxacillin, penicillin’s, ceftriaxone, moxalactam, tetracyclines and carbenicillin with intermediate penetration; and aminoglycosides, first-generation cephalosporins, and clindamycin with little penetration. It was concluded that knowing the blood-brain barrier characteristics, pharmacokinetics and pharmacodynamics of antimicrobial agents, along with the main etiological agents, are the key to choose the most appropriate antibiotic to be applied in each individual case. It is noticed that in the veterinary literature there are few reports describing aspects of pharmacokinetics and pharmacodynamics in feline and canine species, requiring more studies in this area.Infecções no sistema nervoso central (SNC) são menos prevalentes do que em outros órgãos e o tratamento é desafiador. Entre os fatores que tornam o tratamento de infecções bacterianas complicado nesse tecido, destacam-se o fato do mesmo ser envolto pela barreira hematoencefálica, além da dificuldade de obter resultados positivos ao tentar isolar o agente causador por meio de punção de líquido cefalorraquidiano (LCR). Objetiva-se, nesse trabalho, documentar documentar os principais antibióticos utilizados para tratar infecções bacterianas no sistema nervoso central e a interação com a barreira hematoencefálica (BHE). Os antibióticos com ótima penetração na BHE são: trimetoprim, sulfonamidas, metronidazol e cloranfenicol com penetração penetração intermediária são: oxacilinas, penicilinas, ceftriaxone, moxalactam, tetraciclinas e carbenicilina; e com pequena penetração são: aminoglicosídeos, cefalosporinas de primeira geração e clindamicina. É fundamental para a escolha do antibiótico mais adequado para cada caso conhecer características da barreira hematoencefálica, além de determinar a farmacocinética e farmacodinâmica dos antibióticos e seus principais agentes etiológicos. Percebe-se que na literatura veterinária há escassos relatos descrevendo aspectos de farmacocinética e farmacodinâmica nas espécies felina e canina, sendo necessária maior maior quantidade de estudos nesta área
Mitochondrial DNA Diversity and Evolutionary History of Native Human Populations of Northwest Patagonia (Argentina)
The genetic composition of Amerindian descendants from Patagonia has long been a focus of interest, although the information available is still scarce for many geographic areas. Here, we report the first analysis of the variation in the mtDNA control region for an area of northwestern Patagonia, the North of Neuquén, with the aim of studying the processes and historical events that modeled the evolutionary history of these human groups. We analyzed 113 individuals from two localities of northern Neuquén, along with 6 from southern Neuquén and 223 mtDNA sequences previously published from neighboring areas from Argentina and Chile. We estimated the haplotypic variation and spatial structure of molecular variability. Amerindian subhaplogroups predominate in the two samples from northern Neuquén (N= 70), being D1g and C1b13 the most represented, although in different proportion. These samples exhibit Amerindian mtDNA haplotypes similar to the variants from neighboring areas. Most of haplotype variability is observed within group, while variation among groups is relatively low and scarcely associated to geographical space. The most frequent subhaplogroups in northern Neuquén are characteristic of native populations from Patagonia and Chilean Araucania, and probably originated in the region during the Late Pleistocene or Early Holocene. However, the spatial variation of mtDNA haplotypes departs from a latitudinal pattern and suggests differential levels of gene flow among areas during the Late Holocene; with moderate levels across the North of Neuquén as well as between this area and neighbouring populations from Chile and the South of Neuquén and Río Negro
Procesos De Calidad En Las Empresas Del Sector Metalmecánico Certificadas En Iso 9001:2008 Y/O Acreditadas En Iso 17025:2005 En Las Ciudades De Pereira Y Dosquebradas
Número 7; pp. 72 - 90La presente investigación, establece los factores que inciden en la calidad en las grandes empresas
del sector metalmecánico de las ciudades de Pereira y Dosquebradas, presenta el diagnóstico actual hecho para
10 organizaciones estudiadas frente a los factores determinados a través de un instrumento de recolección de
información diseñado para ello, identifica debilidades, fortalezas, amenazas y oportunidades de las mismas
frente a su mejoramiento continuo y elabora una propuesta para las organizaciones en estudio a través de
estrategias que les permitan mantenerse competitivas y establecer pautas que garanticen un mejoramiento
continuo durante toda la cadena productiva de las mismas.
Al final de la investigación se encontró que 76% de las empresas estudiadas cumplen con los factores de calidad
analizados en la presente investigación y que las principales falencias de las mismas están asociadas al
desconocimiento de los factores que inciden en la calidad y su adecuada utilización, entre los cuales destacan,
especialmente, Poka Yoke, calibración de instrumentos de medición y aplicación a premios de calidad.Universidad Libre Seccional Pereir
Genetic diversity and signatures of selection of drug resistance in Plasmodium populations from both human and mosquito hosts in continental Equatorial Guinea
BACKGROUND: In Plasmodium, the high level of genetic diversity and the interactions established by co-infecting parasite populations within the same host may be a source of selection on pathogen virulence and drug resistance. As different patterns have already been described in humans and mosquitoes, parasite diversity and population structure should be studied in both hosts to properly assess their effects on infection and transmission dynamics. This study aimed to characterize the circulating populations of Plasmodium spp and Plasmodium falciparum from a combined set of human blood and mosquito samples gathered in mainland Equatorial Guinea. Further, the origin and evolution of anti-malarial resistance in this area, where malaria remains a major public health problem were traced. METHODS: Plasmodium species infecting humans and mosquitoes were identified by nested-PCR of chelex-extracted DNA from dried blood spot samples and mosquitoes. Analysis of Pfmsp2 gene, anti-malarial-resistance associated genes, Pfdhps, Pfdhfr, Pfcrt and Pfmdr1, neutral microsatellites (STR) loci and Pfdhfr and Pfdhps flanking STR was undertaken to evaluate P. falciparum diversity. RESULTS: Prevalence of infection remains high in mainland Equatorial Guinea. No differences in parasite formula or significant genetic differentiation were seen in the parasite populations in both human and mosquito samples. Point mutations in all genes associated with anti-malarial resistance were highly prevalent. A high prevalence was observed for the Pfdhfr triple mutant in particular, associated with pyrimethamine resistance.Analysis of Pfdhps and Pfdhfr flanking STR revealed a decrease in the genetic diversity. This finding along with multiple independent introductions of Pfdhps mutant haplotypes suggest a soft selective sweep and an increased differentiation at Pfdhfr flanking microsatellites hints a model of positive directional selection for this gene. CONCLUSIONS: Chloroquine is no longer recommended for malaria treatment in Equatorial Guinea but sulphadoxine-pyrimethamine (SP) remains in use in combination with artesunate and is the only drug recommended in preventive chemotherapy in pregnancy. The high prevalence of point mutations in Pfdhfr and Pfdhps points to the danger of an eventual reduction in the efficacy of SP combined therapy in P. falciparum populations in Equatorial Guinea and to the essential continuous monitoring of these two genes.This study was supported by PEst-OE/SAU/LA0018/2011 - Proj. Estratégico LA0018 2011/2012 (http://cmdt.ihmt.unl.pt/index.php/pt/) and PTDC/SAU-EPI/113326/2009, “Fundacão para a Ciência e Tecnologia/Ministério da Educação e Ciência”, FCT/MEC (http://alfa.fct.mctes.pt/index.phtml.pt), Portugal and by “Instituto de Salud Carlos III, Ministerio de Ciencia e Innovación”, Madrid, Spain. C. Mendes and P. Salgueiro hold FCT grants (SRFH/BD/41473/2007 and SFRH/BPD/72532/2010, respectively).S
Autoenxerto pedicular congelado para preservação do membro em um cão com osteossarcoma femoral
Osteosarcoma (OSA) is the most common bone tumor diagnosed in dogs and represents approximately 85% of canine skeletal tumors. The most commonly employed therapy is amputation of the limb followed by chemotherapy. However, preservation of the afflicted limb has been successful for patients with concomitant neurological or orthopedic conditions, which are contraindications to the complete amputation, or with owners reluctant to the possibility of amputation. For these reasons, the purpose of this study was to describe the technical procedures that allowed limb salvage through the use of pedicle frozen grafts in a dog with femoral OSA. Surgical procedures consisted of a femoral diaphyseal osteotomy with tearing of the soft tissues; thus, creating a bone pedicle that was frozen in liquid nitrogen according to the protocol outlined by TSUCHIYA et al. (2005). Limb function remained satisfactory for six months.Dentre os tumores ósseos que acometem os cães, o osteossarcoma (OSA) é o mais frequentemente diagnosticado e representa 85% das neoplasias de origem esquelética. A terapêutica comumente indicada é a amputação do membro, seguida de quimioterapia. No entanto, a preservação do membro afetado tem sido realizada em pacientes com afecções neurológicas ou ortopédicas concomitantes, que contraindicam a amputação radical ou em caso de tutores relutantes em aceitar a amputação. Em razão disso, o objetivo do presente trabalho é descrever a técnica de preservação de membro através de pedículo congelado em nitrogênio líquido em um cão com osteossarcoma de fêmur. A técnica cirúrgica empregada consistiu na osteotomia diafisária do fêmur, com divulsão dos tecidos moles, criando assim o pedículo ósseo que foi congelado em nitrogênio líquido, seguindo o protocolo realizado por TSUCHIYA et al. (2005). O cão permaneceu com a função satisfatória do membro por um período de seis meses
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