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Search Results: 1 - 10 of 604493 matches for " D.M.F.;Chimelli "
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Quantitative evidence for neurofilament heavy subunit aggregation in motor neurons of spinal cords of patients with amyotrophic lateral sclerosis
Mendon?a, D.M.F.;Chimelli, L.;Martinez, A.M.B.;
Brazilian Journal of Medical and Biological Research , 2005, DOI: 10.1590/S0100-879X2005000600015
Abstract: amyotrophic lateral sclerosis (als), a neurodegenerative disease of unknown etiology, affects motor neurons leading to atrophy of skeletal muscles, paralysis and death. there is evidence for the accumulation of neurofilaments (nf) in motor neurons of the spinal cord in als cases. nf are major structural elements of the neuronal cytoskeleton. they play an important role in cell architecture and differentiation and in the determination and maintenance of fiber caliber. they are composed of three different polypeptides: light (nf-l), medium (nf-m) and heavy (nf-h) subunits. in the present study, we performed a morphological and quantitative immunohistochemical analysis to evaluate the accumulation of nf and the presence of each subunit in control and als cases. spinal cords from patients without neurological disease and from als patients were obtained at autopsy. in all als cases there was a marked loss of motor neurons, besides atrophic neurons and preserved neurons with cytoplasmic inclusions, and extensive gliosis. in control cases, the immunoreaction in the cytoplasm of neurons was weak for phosphorylated nf-h, strong for nf-m and weak for nf-l. in als cases, anterior horn neurons showed intense immunoreactivity in focal regions of neuronal perikarya for all subunits, although the difference in the integrated optical density was statistically significant only for nf-h. furthermore, we also observed dilated axons (spheroids), which were immunopositive for nf-h but negative for nf-m and nf-l. in conclusion, we present qualitative and quantitative evidence of nf-h subunit accumulation in neuronal perikarya and spheroids, which suggests a possible role of this subunit in the pathogenesis of als.
Quantitative evidence for neurofilament heavy subunit aggregation in motor neurons of spinal cords of patients with amyotrophic lateral sclerosis
Mendon?a D.M.F.,Chimelli L.,Martinez A.M.B.
Brazilian Journal of Medical and Biological Research , 2005,
Abstract: Amyotrophic lateral sclerosis (ALS), a neurodegenerative disease of unknown etiology, affects motor neurons leading to atrophy of skeletal muscles, paralysis and death. There is evidence for the accumulation of neurofilaments (NF) in motor neurons of the spinal cord in ALS cases. NF are major structural elements of the neuronal cytoskeleton. They play an important role in cell architecture and differentiation and in the determination and maintenance of fiber caliber. They are composed of three different polypeptides: light (NF-L), medium (NF-M) and heavy (NF-H) subunits. In the present study, we performed a morphological and quantitative immunohistochemical analysis to evaluate the accumulation of NF and the presence of each subunit in control and ALS cases. Spinal cords from patients without neurological disease and from ALS patients were obtained at autopsy. In all ALS cases there was a marked loss of motor neurons, besides atrophic neurons and preserved neurons with cytoplasmic inclusions, and extensive gliosis. In control cases, the immunoreaction in the cytoplasm of neurons was weak for phosphorylated NF-H, strong for NF-M and weak for NF-L. In ALS cases, anterior horn neurons showed intense immunoreactivity in focal regions of neuronal perikarya for all subunits, although the difference in the integrated optical density was statistically significant only for NF-H. Furthermore, we also observed dilated axons (spheroids), which were immunopositive for NF-H but negative for NF-M and NF-L. In conclusion, we present qualitative and quantitative evidence of NF-H subunit accumulation in neuronal perikarya and spheroids, which suggests a possible role of this subunit in the pathogenesis of ALS.
Aberrant crypt foci and colon cancer: comparison between a short- and medium-term bioassay for colon carcinogenesis using dimethylhydrazine in Wistar rats
Rodrigues M.A.M.,Silva L.A.G.,Salvadori D.M.F.,de Camargo J.L.V.
Brazilian Journal of Medical and Biological Research , 2002,
Abstract: Aberrant crypt foci (ACF) in the colon of carcinogen-treated rodents are considered to be the earliest hallmark of colon carcinogenesis. In the present study the relationship between a short-term (4 weeks) and medium-term (30 weeks) assay was assessed in a model of colon carcinogenesis induced by dimethylhydrazine (DMH) in the rat. Six-week-old male Wistar rats were given subcutaneous injections of DMH (40 mg/kg) twice a week for 2 weeks and killed at the end of the 4th or 30th week. ACF were scored for number, distribution pattern along the colon and crypt multiplicity in 0.1% methylene-blue whole-mount preparations. ACF were distinguished from normal crypts by their larger size and elliptical shape. The incidence, distribution and morphology of colon tumors were recorded. The majority of ACF were present in the middle and distal colon of DMH-treated rats and their number increased with time. By the 4th week, 91.5% ACF were composed of one or two crypts and 8.5% had three or more crypts, while by the 30th week 46.9% ACF had three or more crypts. Thus, a progression of ACF consisting of multiple crypts was observed from the 4th to the 30th week. Nine well-differentiated adenocarcinomas were found in 10 rats by the 30th week. Seven tumors were located in the distal colon and two in the middle colon. No tumor was found in the proximal colon. The present data indicate that induction of ACF by DMH in the short-term (4 weeks) assay was correlated with development of well-differentiated adenocarcinomas in the medium-term (30 weeks) assay.
Aberrant crypt foci and colon cancer: comparison between a short- and medium-term bioassay for colon carcinogenesis using dimethylhydrazine in Wistar rats
Rodrigues, M.A.M.;Silva, L.A.G.;Salvadori, D.M.F.;de Camargo, J.L.V.;Montenegro, M.R.;
Brazilian Journal of Medical and Biological Research , 2002, DOI: 10.1590/S0100-879X2002000300010
Abstract: aberrant crypt foci (acf) in the colon of carcinogen-treated rodents are considered to be the earliest hallmark of colon carcinogenesis. in the present study the relationship between a short-term (4 weeks) and medium-term (30 weeks) assay was assessed in a model of colon carcinogenesis induced by dimethylhydrazine (dmh) in the rat. six-week-old male wistar rats were given subcutaneous injections of dmh (40 mg/kg) twice a week for 2 weeks and killed at the end of the 4th or 30th week. acf were scored for number, distribution pattern along the colon and crypt multiplicity in 0.1% methylene-blue whole-mount preparations. acf were distinguished from normal crypts by their larger size and elliptical shape. the incidence, distribution and morphology of colon tumors were recorded. the majority of acf were present in the middle and distal colon of dmh-treated rats and their number increased with time. by the 4th week, 91.5% acf were composed of one or two crypts and 8.5% had three or more crypts, while by the 30th week 46.9% acf had three or more crypts. thus, a progression of acf consisting of multiple crypts was observed from the 4th to the 30th week. nine well-differentiated adenocarcinomas were found in 10 rats by the 30th week. seven tumors were located in the distal colon and two in the middle colon. no tumor was found in the proximal colon. the present data indicate that induction of acf by dmh in the short-term (4 weeks) assay was correlated with development of well-differentiated adenocarcinomas in the medium-term (30 weeks) assay.
Efecto de monensina sobre el aumento de peso y prevención del meteorismo en novillos sobre una pradera de alfalfa
ROSSI,D.M.; NAVARRO,F.; GRIVEL,C.D.;
Archivos de medicina veterinaria , 1997, DOI: 10.4067/S0301-732X1997000200013
Abstract: an experiment was carried out, from october to december 1992, in order to evaluate bloat prevention and weight gain of steers. animals were on an alfalfa pasture with previous records of bloating. two groups of 20 selected steers were randomly divided into two separate fields. the treated group, with an initial body weight of 251.5 ± 28.0 kg at the beginning of the experiment, received capsules containing 32 g of sodium monensine. the control group weighed 253.6 ± 21.2 kg at the time and received no capsules. after 75 days the average weight increase in the treated group was 73.5 kg, while the control was 60.2 kg. to evaluate the degree of bloating, animals were divided into three categories: a) nonaffected; b) bloated; c) severely bloated. it was concluded that the sodium monensine treatment had a positive effect on bloating prevention and the treated steers gained 22% more weight than the untreated
Efecto de monensina sobre el aumento de peso y prevención del meteorismo en novillos sobre una pradera de alfalfa Effect of monensin on weight gain and bloat prevention in steers feeding on lucerne pasture
D.M. ROSSI,F. NAVARRO,C.D. GRIVEL
Archivos de medicina veterinaria , 1997,
Abstract: En los meses de octubre, noviembre y diciembre de 1992 se llevó a cabo un ensayo para evaluar el efecto de cápsulas de Monensina sobre el aumento de peso diario y su capacidad de preven-ción del empaste en novillos Aberdeen Angus que pastoreaban una pradera de alfalfa (Medicago sativa). Dichas cápsulas tienen como principio activo 32g de Monensina sódica. Se seleccionaron 40 novillos y se distribuyeron al azar en dos lotes de 20 animales cada uno. El lote testigo inició la experiencia con un peso promedio de 253.7 ± 21.2 kg y el lote tratado 251.5 ± 28.0 kg. El aumento de peso a los 75 días fue de 73.5 kg para los tratados y de 60.2 kg de promedio para los testigos, siendo las diferencias significativas (p < 0.01). Para determinar la gravedad del empaste se determinaron 3 grados de afectación: a) Animal normal; b) Animal empastado y c) Animal muy empastado. El grado de empaste fue mayor en todos los casos en los animales no medicados (p < 0.01) Se concluye que las cápsulas tuvieron un efecto positivo en la prevención del empaste y además los novillos tratados obtuvieron una ganancia de peso de un 22% mayor que los no tratados. En ambos casos las diferencias fueron significativas (p < 0.01). An experiment was carried out, from October to December 1992, in order to evaluate bloat prevention and weight gain of steers. Animals were on an alfalfa pasture with previous records of bloating. Two groups of 20 selected steers were randomly divided into two separate fields. The treated group, with an initial body weight of 251.5 ± 28.0 kg at the beginning of the experiment, received capsules containing 32 g of Sodium Monensine. The control group weighed 253.6 ± 21.2 kg at the time and received no capsules. After 75 days the average weight increase in the treated group was 73.5 kg, while the control was 60.2 kg. To evaluate the degree of bloating, animals were divided into three categories: A) nonaffected; B) bloated; C) severely bloated. It was concluded that the Sodium Monensine treatment had a positive effect on bloating prevention and the treated steers gained 22% more weight than the untreated
Lead and zinc selective precipitation from leach electric arc furnace dust solutions
Lenz, D.M.;Martins, F.B.;
Matéria (Rio de Janeiro) , 2007, DOI: 10.1590/S1517-70762007000300011
Abstract: electric-arc furnace (eaf) dust is considered a hazardous industrial waste. in this work, chemical and mineralogical investigations of eaf dust from siderúrgica rio-grandense (rs, brazil) were performed. the elements aluminum, calcium, lead, cadmium, chromium, magnesium, manganese, nickel, potassium, silicon, sodium, tin, iron, zinc, sulphur, oxygen, and carbon were found in eaf dust. the concentration of zinc and iron showed an average value of approximately 20% (weight basis) and these elements are mainly present as zno.fe2o3 (zinc ferrite) and zno (zincite) mineralogical phases. also, eaf dusts were submitted to an integrated hydrometallurgical process composed by a hydrolyzed step, followed by a fusion step and a strong alkaline leaching. a subsequent chemical precipitation was carried out in order to promote selective separation of zinc and lead from the leach solution. sodium sulphide was successfully employed as precipitant agent. when the weight ratio of sodium sulphide to lead was around 2.0, lead could be selectively extracted from leach solution. after lead precipitation without zinc concomitant loss, a weight ratio of sodium sulphide to zinc of around 3.0 was used to precipitate all zinc. thus, eaf dust has a great potential to be used as a source of metals extraction due to its rich chemical composition and also for the viability of the proposed selective separation process.
Mioepitelioma benigno: presentación de un caso clínico
Ostrosky,A.; Villa,D.M.; González,M.; Klurfan,F.;
Revista Espa?ola de Cirugía Oral y Maxilofacial , 2007, DOI: 10.4321/S1130-05582007000500006
Abstract: we present a case of benign myoepithelioma of the parotid gland, which was treated by superficial gland lobectomy along with facial nerve conservation. a differential diagnosis with other benign tumors with similar clinical signs such as pleomorphic adenoma is made. the importance of a correct anatomopathologic diagnosis is also stressed, as is making a differential diagnosis with epi-myoepithelial carcinomas.
Modelación de la corrosión atmosférica del cobre en la provincia de Las Palmas. Estudios mediante técnicas clásicas y electroquímicas Modelling of the Atmospheric Corrosion of Copper in the Province of Las Palmas. Studies Using Classic and Electrochemical Techniques
P.M. González,D.M. Mos,F.J. Santana,J. Vaswani
Portugaliae Electrochimica Acta , 2008,
Abstract: La simulación de la acción de atmósferas naturales sobre metales empleando técnicas electroquímicas conjuntamente con ensayos acelerados presenta unas características que lo hacen muy interesante desde el punto de vista del estudio y predicción de la corrosión, ya que nos permitirá prever el comportamiento de un metal expuesto en un ambiente determinado sin necesidad de realizar ensayos de campo, con el consiguiente ahorro económico y de tiempo. Este estudio tiene la finalidad de correlacionar la velocidad de corrosión atmosférica del cobre obtenida mediante exposición atmosférica en estaciones en la provincia de Las Palmas con las distintas variables que intervienen en el proceso corrosivo. De la misma manera para la determinación del modelo matemático que mejor se ajuste a los resultados obtenidos experimentalmente y tenga en cuenta los parámetros de mayor influencia en el proceso corrosivo se ha utilizado el modelo de la Ley Potencial que, de forma genérica, reproduce el proceso electroquímico que se desarrolla en la corrosión atmosférica. Simulation of the effects of natural atmospheres on metals using electrochemical techniques together with accelerated tests presents certain characteristics that make it highly interesting from the point of view of the study and prediction of corrosion. It will enable us to forecast the behavior of a metal exposed to a particular environment without the need to perform field test, with a consequent saving in terms of time and financial expenses. The aim of this study is to establish the correlation between the atmospheric corrosion rate of copper (obtained by atmospheric exposure at stations located in the province of Las Palmas, Spain) with the different variables that intervene in the corrosion process. In the same way, for the determination of the mathematical model that best fits the results obtained experimentally and which takes into account the most influential parameters in the corrosion process, the power Law model has been used which generically reproduces the electrochemical process which occurs in atmospheric corrosion.
Bushclumps as refugia for small mammals in two Eastern Cape conservation areas
G.M. Whittington-Jones,R.T.F. Bernard,D.M. Parker
African Zoology , 2011,
Abstract: Bushclumps are scattered islands of thicket-like vegetation within a matrix of more open vegetation. We investigated the role of bushclumps as refugia for small mammals, and examined the effect of a limited number of abiotic and biotic factors on their richness, diversity and abundance. Small mammals were surveyed using Sherman small mammal traps at two sites in the Eastern Cape Province, South Africa (Mountain Zebra National Park and Kwandwe Private Game Reserve). Soil hardness and seed abundance, inside and outside bushclumps, were determined. Trap success was significantly higher inside bushclumps than in areas outside, and species diversity and the abundance of small mammals were greater within bushclumps compared to outside. Bushclumps also had significantly softer soil and a higher concentration of seeds. We conclude that bushclumps provide a concentrated source of food and protection from predators for small mammals, and are thus used significantly more than adjacent open areas. The conservation of bushclumps is therefore important for the overall maintenance of ecosystem functioning.
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