6,448 research outputs found

    Gastrointestinal helminths in calves and cows in an organic milk production system

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    The main aim of this study was to determine the distribution of populations of gastrointestinal helminths in lactating crossbred cows and calves during the grazing season in an organic milk production system. In addition, the potential importance of the peripartum in relation to the parasite load was examined. Between January 2007 and December 2008, parasitological fecal examinations were performed on cattle belonging to the Integrated Animal Production Program of Embrapa Agrobiology. The cows' parasite load remained low during the study period, and there were no statistical differences (p > 0.05) in comparisons between the seasons. The average egg count showed a positive correlation (0.80) with the peripartum, such that egg elimination per gram (p < 0.05) was higher during the week of labor than during the pre and postpartum periods. Calves showed low parasite loads, with significantly higher egg elimination (p < 0.05) during the winter. The study indicated that infection with gastrointestinal helminths was not a limiting factor for milk production in the organic system. Specifically, it was concluded that the nematode load can be maintained at moderate levels throughout the production system, even in the absence of anthelmintic treatment

    Distinct load dependence of relaxation rate and diastolic function in Oryctolagus cuniculus and Ratus norvegicus

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    This study investigated potential differences on load dependence of relaxation rate and diastolic function between Oryctolagus cuniculus and Ratus norvegicus, which have constitutive differences in the mechanisms involved in myocardial inactivation. Load dependence of relaxation rate and diastolic function were evaluated with the response of left ventricular time constant tau and diastolic pressure-dimension relation to beat-to-beat aortic constrictions in open-chest rabbits and rats. Afterload levels were normalized, being expressed as a percentage of peak isovolumetric pressure (relative load). In control heartbeats, relaxation rate and diastolic function were similar in the two animal species. They presented, however, distinct responses to afterload elevations. In rabbits, time constant decreased similar to7% and diastolic pressure-dimension relation remained unchanged when afterload was elevated to a relative load of 73-76%. Above this afterload level, a significant deceleration of relaxation rate (increase of time constant) and an upward shift of diastolic pressure-dimension relation were observed. In rats, afterload elevations accelerated pressure fall up to a relative load of 97-100% and no afterload-induced shift of the diastolic pressure-dimension relation was observed. This study provides, therefore, evidence that Oryctolagus cuniculus has lower afterload reserve of myocardial relaxation and diastolic function than Ratus norvegicus

    Stroke in patients with sickle cell disease - Clinical and neurological aspects

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    The aim of this study was to characterize a group of patients (n=8) with sickle cell disease (SCD) and ischemic stroke concerning the clinical, neurological, imaging and progressive aspects. Data were collected from records and completed with an interview of patients and their parents. In this study there were 8 patients with ages ranging from 10 to 23 years old; SCD diagnosis was given between one and two years of age with clinical features of fatigue and anemia. The stroke was ischemic in all individuals and the first cerebrovascular event occurred before 6 years of age; 3 patients had recurrence of stroke despite prophylactic blood transfusion therapy and both cerebral hemispheres were affected in 4 patients. Clinical and neurological current features observed were: acute pain crises, sialorrhea, mouth breathing, motor, and neuropsychological impairments resulting from cortical-subcortical structure lesions.661303

    Mitochondrial-dependent apoptosis in Huntington's disease human cybrids

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    We investigated the involvement of mitochondrial-dependent apoptosis in Huntington's disease (HD) vs. control (CTR) cybrids, obtained from the fusion of human platelets with mitochondrial DNA-depleted NT2 cells, and further exposed to 3-nitropropionic acid (3-NP) or staurosporine (STS). Untreated HD cybrids did not exhibit significant modifications in the activity of mitochondrial respiratory chain complexes I-IV or in mtDNA sequence variations suggestive of a primary role in mitochondrial susceptibility in the subpopulation of HD carriers studied. However, a slight decrease in mitochondrial membrane potential and increased formation of intracellular hydroperoxides was observed in HD cybrids under basal conditions. Furthermore, apoptotic nuclei morphology and a moderate increase in caspase-3 activation, as well as increased levels of superoxide ions and hydroperoxides were observed in HD cybrids upon 3-NP or STS treatment. 3-NP-evoked apoptosis in HD cybrids involved cytochrome c and AIF release from mitochondria, which was associated with mitochondrial Bax translocation. CTR cybrids subjected to 3-NP showed increased mitochondrial Bax and Bim levels and the release of AIF, but not cytochrome c, suggesting a different mode of cell death, linked to the loss of membrane integrity. Additionally, increased mitochondrial Bim and Bak levels, and a slight release of cytochrome c in untreated HD cybrids may help to explain their moderate susceptibility to mitochondrial-dependent apoptosi

    Tissue Localization and Extracellular Matrix Degradation by PI, PII and PIII Snake Venom Metalloproteinases: Clues on the Mechanisms of Venom-Induced Hemorrhage

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    20 páginas, 4 figuras, 3 tablas y 7 tablas en material suplementario.Snake venom hemorrhagic metalloproteinases (SVMPs) of the PI, PII and PIII classes were compared in terms of tissue localization and their ability to hydrolyze basement membrane components in vivo, as well as by a proteomics analysis of exudates collected in tissue injected with these enzymes. Immunohistochemical analyses of co-localization of these SVMPs with type IV collagen revealed that PII and PIII enzymes co-localized with type IV collagen in capillaries, arterioles and post-capillary venules to a higher extent than PI SVMP, which showed a more widespread distribution in the tissue. The patterns of hydrolysis by these three SVMPs of laminin, type VI collagen and nidogen in vivo greatly differ, whereas the three enzymes showed a similar pattern of degradation of type IV collagen, supporting the concept that hydrolysis of this component is critical for the destabilization of microvessel structure leading to hemorrhage. Proteomic analysis of wound exudate revealed similarities and differences between the action of the three SVMPs. Higher extent of proteolysis was observed for the PI enzyme regarding several extracellular matrix components and fibrinogen, whereas exudates from mice injected with PII and PIII SVMPs had higher amounts of some intracellular proteins. Our results provide novel clues for understanding the mechanisms by which SVMPs induce damage to the microvasculature and generate hemorrhage.This work was performed in partial fulfillment of the requirements for the PhD degree for Cristina Herrera at Universidad de Costa Rica.Peer reviewe

    Cerebrovascular disease: language acquisition in preschool children

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    We describe ten children, aging 5 years and 1 month until 5 years and 11 months, when the phonoaudiological assessment was conducted. They are divided according to cerebrovascular disease, in CVD group (CVD-G) and control group (cG). Children were seen and CVD was confirmed in the acute phase at UNICAMP hospital. Audiologic assessment, protocol for Infant language assessment, and Peabody picture vocabulary test were used in the evaluations. The qualitative analysis of the subjects from a phonoaudiological and neurological point of view has shown the recovery of acquired language desorder (ALD) with no influence whatsoever in the development of 2 subjects and subtle language and/or learning process alterations for 3 subjects. The cases study has revealed that all aspects of language development in preschool children should be analyzed in an individual, quantitative, and qualitative basis to lead to conclusive findings.633B80781

    Evaluation of biventricular function in the rat: a new experimental model

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    The use of small animals in cardiovascular research has increased over recent years. This might be a limitation when evaluation of biventricular function is required. Although evaluation of left ventricular (LV) pressure and volume is already possible in small animals, concomitant evaluation of right ventricle function has been limited to large animals. The study describes a new model to assess pressures and dimensions of both ventricles simultaneously in the adult rat. Adult Wistar rats (n = 12), weighing 372 +/- 16 g, were anesthetized with pentobarbital (60 mg/kg, i.p.) and ventilated through a tracheostomy (60 cpm, 1 ml/100 g). Under a dissecting microscope (6x) the right jugular vein was catheterized. After sternotomy and pericardiotomy, three crystals were placed along the major cardiac transverse diameter: in the right subendocardium of the interventricular septum and on the epicardial surfaces of the RV and LV free walls. In addition, two high-fidelity catheters were introduced through the apex into the RV (2F, Millar) and LV (3F, Millar) cavities. This allowed the measurement of all parameters derived from pressure and dimension curves of the RV and LV, including pressure-dimension loops. This study describes, for the first time, a model that allows simultaneous evaluation of biventricular pressure and dimensions in an animal model as small as an adult rat. This model opens up new perspectives for the establishment of correlations between molecular biology and hemodynamic data in both ventricles, which is particularly important as more differences between the two ventricles are being found

    Secreted Endothelial Cell Factors Immobilized on Collagen Scaffolds Enhance the Recipient Endothelial Cell Environment

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    Strategies to design novel vascular scaffolds are a continuing aim in tissue engineering and often such designs encompass the use of recombinant factors to enhance the performance of the scaffold. The established use of cell secretion utilized in feeder systems and conditioned media offer a source of paracrine factors, which has potential to be used in tissue-engineered (TE) scaffolds. Here we utilize this principle from endothelial cells (ECs), to create a novel TE scaffold by harnessing secreted factors and immobilizing these to collagen scaffolds. This research revealed increased cellular attachment and positive angiogenic gene upregulation responses in recipient ECs grown on these conditioned scaffolds. Also, the conditioning method did not affect the mechanical structural integrity of the scaffolds. These results may advocate the potential use of this system to improve vascular scaffolds' in vivo performance. In addition, this process may be a future method utilized to improve other tissue engineering scaffold therapies

    Brain hypoperfusion in adolescents dependent of multiple drugs

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    Brain SPECT imaging (BSI) with statistical parametric mapping (SPM) offers a clear and accurate vision of perfusion changes. Objective: To study brain perfusion abnormalities in adolescents' dependent of multiple drugs. Method: Sixteen male patients (15.1 +/- 2.1 years) were submitted to (99m)Tc-HMPAO BSI with SPM. Results: Cortical hypoperfusion occurred in 7/16 patients (44%). There was a significant inverse correlation between the number of hypoperfused regions and the patient's age (p= -0.6737; p=0.004) and with the age when the drug dependence began (p= -0.5616; p=0.023). There was also a tendency towards an inverse correlation between regions of hypoperfusion and the duration of the drug dependence. Conclusion: BSI with SPM can help detect hypoperfusion in adolescents dependent on multiple drugs. The younger the patients, the more regions of hypoperfusion are noted. Probably, the neuronal plasticity has an important role in this phenomenon because the highest neural activity occurs in childhood.68216116
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