998 resultados para Breton, Andre
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Aging affects peripheral nerve function and regeneration in experimental models but few literature reports deal with animals aged more than one year. We investigated morphological and morphometric aspects of the sural nerve in aging rats. Female Wistar rats 360, 640 and 720 days old were killed, proximal and distal segments of the right and left sural nerves were prepared for light microscopy and computerized morphometry. No morphometric differences between proximal and distal segments or between right and left sides at the same levels were found in all experimental groups. No increase in fiber and axon sizes was observed from 360 to 720 days. Likewise, no difference in total myelinated fiber number was observed between groups. Myelinated fiber population distribution was bimodal, being the 720-days old animals` distribution shifted to the left, indicating a reduction of the fiber diameters. The 9 ratio distribution of the 720-days old animals` myelinated fiber was also shifted to the left, which suggests axonal atrophy. Morphological alterations due to aging were observed, mainly related to the myelin sheath, which suggests demyelination. Large fibers were more affected than the smaller ones. Axon abnormalities were not as common or as obvious as the myelin changes and Wallerian degeneration was rarely found. These alterations were observed in all experimental groups but were much less pronounced in rats 360 days old and their severity increased with aging. in conclusion, the present study indicates that the aging neuropathy present in the sural nerve of female rats is both axonal and demyelinating. (C) 2008 Elsevier B.V. All rights reserved.
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The risk of developing cardiovascular disease is higher in obese than in non-obese individuals. Surgery for obesity is effective in reducing weight and resolution of diabetes, hypertension, and dyslipidemia. Our aim was to assess the estimated 10-year cardiovascular risk of obese patients before and after treatment of obesity with a gastric bypass. Weight, body mass index systolic and diastolic blood pressure, lipid profile, glycemia, and history of cardiovascular disease were obtained for obese patients before and 2 years after Roux-en-Y gastric bypass surgery. Ten-year cardiovascular risk was calculated using the Framingham score. Forty-two patients were included in the study. We observed a significant reduction (p < 0.05) of 10-year cardiovascular risk mainly associated with weight reduction and improvement of comorbidities associated with obesity. The benefits were greater among patients who already presented known risk factors such as diabetes and hypertension. Superobese patients benefited as early as 2 years after surgery, when weight loss was greater. Weight loss secondary to surgery was sustained after 2 years and promoted improvement of comorbidities, with an important reduction of 10-year cardiovascular risk especially among patients with previous risk factors.
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BACKGROUND Hypertension, a risk factor for cardiovascular diseases, and obesity are becoming a health problem in many developed and developing countries, as Brazil. Although hypertension and obesity are both closely associated, there is no universal anthropometric marker of this association. This is probably due to distinct population characteristics, and in the case of Brazil, the highly heterogeneous population. We evaluated which anthropometric measurement closely relates to high blood pressure in a sample of Brazilian factory workers. METHODS A cross-sectional study was designed. In this study, multiple logistic regression and receiver operating characteristics analysis were performed in order to obtain the precise relevance of each anthropometric measurement as a blood pressure marker. Nine hundred and thirteen men, 36 +/- 8 years-old, were submitted to a standardized questionnaire of demographic and risk factors knowledge, anthropometric and conventional blood pressure measurements were taken, and blood sample evaluations of glucose, total cholesterol, LDL-Cholesterol, and triglycerides were performed. RESULTS Overweightness or obesity was identified in 64, 11.1% were smokers and hypertension was detected in 29.2% of the participants. A linear correlation was significant (P < 0.001) between both the systolic and diastolic blood pressure and all anthropometric measurements, except for the systolic blood pressure and waist-to-hip ratio. Waist circumference (WC) was the only independent anthropometric measurement related to hypertension. Hypertensive patients presented all anthropometric measurements larger than normotensives. CONCLUSIONS Age and WC were the only independent predictors of hypertension, indicating that this simple measurement may be useful as a marker of hypertension in the Brazilian male, younger adult population. Am J Hypertens 2009; 22:980-984 (C) 2009 American Journal of Hypertension, Ltd.
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Objective. This study aims to analyze the expression of cancer testis antigen 45 (CT45) in normal tissues and in plasma cell disorders and to identify possible associations with clinical data and prognosis in multiple myeloma (MM) patients. Materials and Methods. Expression of CT45 was studied in 20 normal tissues (testis, placenta, skeletal muscle, bladder, lung, spleen, heart, brain and fetal brain, thymus, uterus, stomach, mammary gland, pancreas, prostate, small intestine, kidney, adrenal gland, spinal cord, colon, and one pool of 10 normal bone marrow samples) and bone marrow aspirates from 3 monoclonal gammopathies of undetermined significance, 5 solitary plasmacytomas, 61 newly diagnosed MM patients and MM cell line U266 by reverse transcriptase polymerase chain reaction. Results. CT45 was positive in 3 of 20 (15%) normal tissues tested: lung, brain (both fetal and adult), and spinal cord. Among monoclonal gammopathies, CT45 was positive in 2 of 5 (40%) solitary plasmacytomas bone marrow aspirates, 10 of 61 (16%) MM bone marrow aspirates, and in the U266 MM cell line. Conclusions. We did not find associations between bone marrow histology and CT45 expression. However, we demonstrated for the first time that positive expression of CT45 was associated with poor prognostic (international Staging System) and poor outcomes in MM patients, meaning that CT45-positive cases presented seven times more chance of worse evolution than the negative ones. (C) 2009 ISEH - Society for Hematology and Stem Cells. Published by Elsevier Inc.
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Susceptibility to systemic lupus erythematosus (SLE) has been associated with immunologic, environmental, and genetic factors. To uncover a possible association between MBL2 gene polymorphisms and SLE, we analyzed functional polymorphisms in the promoter and first exon of the MBL2 gene in 134 Brazilian SLE patients and 101 healthy controls. Genotype and allele frequencies of MBL2 A/O polymorphism were significantly different between patients and controls, and the 0 allele was associated with an increased risk of SLE. An association between low mannose binding lectin (MBL) producer combined genotypes and increased risk for SLE was also reported. Furthermore, when stratifying SLE patients according to clinical and laboratory data, an association between the A/O genotype and nephritic disorders and between the X/Y genotype and antiphospholipid syndrome was evident. Combined genotypes responsible for low MBL production were more frequently observed in SLE patients with nephritis. Our results indicate MBL2 polymorphisms as possible risk factors for SLE development and disease-related clinical manifestations. (C) 2011 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.
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The etiology of irritable bowel syndrome (IBS) is complex and multifaceted. Psychosocial factors play a role in such a process. Several reports suggest that IBS patients have increased psychopathology scores as compared with population controls. The influence of depressive symptoms on rectal sensitivity thresholds vary across different studies. The influence of predominant bowel habits on rectal sensitivity thresholds as determined by barostat-based investigations is not well established. The present report aimed to investigate the influence of depressive symptoms on rectal sensitivity in different subtypes of IBS patients (diarrhea/constipation-predominant vs. alternating subtypes). Depressive symptoms correlated well with first pain sensitivity threshold in alternating patients (n = 8; [rho] = -0.77; p = 0.02) but not in diarrhea/constipation predominant symptoms (n = 11; [rho] = -0.44; p = 0.27). These data suggest that depressive symptoms might impact pain thresholds differently according to the subtype of IBS.
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Background: There is only limited knowledge on how the quantification of valvular regurgitation by color Doppler is affected by changing blood viscosity. This study was designed to evaluate the effect of changing blood viscosity on the vena contracta width using an in vitro model of valvular insufficiency capable of providing ample variation in the rate and stroke volume. Methods: We constructed a pulsatile flow model filled with human blood at varying hematocrit (15%, 35%, and 55%) and corresponding blood viscosity (blood/water viscosity: 2.6, 4.8, 9.1) levels in which jets were driven through a known orifice (7 mm(2)) into a 110 mL compliant receiving chamber (compliance: 2.2 mL/mmHg) by a pulsatile pump. In addition, we used variable pump stroke volumes (5, 7.5, and 10 mL) and rates (40, 60, and 80 ppm). Vena contracta region was imaged using a 3.5 MHz transducer. Pressure and volume in the flow model were kept constant during each experimental condition, as well as ultrasound settings. Results: Blood viscosity variation in the experimental range did not induce significant changes in vena contracta dimensions. Also, vena contracta width did not change from normal to low hematocrit and viscosity levels. A very modest increase only in vena contracta dimension was observed at very high level of blood viscosity when hematocrit was set to 55% . Pump rate, in the evaluated range, did not influence vena contracta width. These results in controlled experimental settings suggest that the vena contracta is an accurate quantitative method for quantifying valvular regurgitation even when this condition is associated with anemia, a frequent finding in patients with valvular heart disease.
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Previous studies have shown that venoms of social wasps and bees exhibit strong anticoagulant activity. The present study describes the anticoagulant and fibrinogen-degrading pharmacological properties of the venom of Polybia occidentalis social wasp. The results demonstrated that this venom presented anticoagulant effect, inhibiting the coagulation at different steps of the clotting pathway (intrinsic, extrinsic and common pathway). The venom inhibited platelet aggregation and degraded plasma fibrinogen, possibly containing metal-dependent metalloproteases that specifically cleave the B beta-chain of fibrinogen. In conclusion, fibrinogenolytic and anticoagulant properties of this wasp venom find a potential application in drug development for the treatment of thrombotic disorders. For that, further studies should be carried out in order to identify and isolate the active compounds responsible for these effects. Blood Coagul Fibrinolysis 21: 653-659 (c) 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins.
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The aim of this study was to evaluate the protective effect of hydrogen sulfide (H(2)S) on ethanol-induced gastric lesions in mice and the influence of ATP-sensitive potassium (K(ATP)) channels, capsaicin-sensitive sensory afferent neurons, and transient receptor potential vanilloid (TRPV) 1 receptors on such an effect. Saline and L-cysteine alone or with propargylglycine, sodium hydrogen sulfide (NaHS), or Lawesson`s reagent were administrated for testing purposes. For other experiments, mice were pretreated with glibenclamide, neurotoxic doses of capsaicin, or capsazepine. Afterward, mice received L-cysteine, NaHS, or Lawesson`s reagent. After 30 min, 50% ethanol was administrated by gavage. After 1 h, mice were sacrificed, and gastric damage was evaluated by macroscopic and microscopic analyses. L-Cysteine, NaHS, and Lawesson`s reagent treatment prevented ethanol-induced macroscopic and microscopic gastric damage in a dose-dependent manner. Administration of propargylglycine, an inhibitor of endogenous H(2)S synthesis, reversed gastric protection induced by L-cysteine. Glibenclamide reversed L-cysteine, NaHS, or Lawesson`s reagent gastroprotective effects against ethanol-induced macroscopic damage in a dose-dependent manner. Chemical ablation of sensory afferent neurons by capsaicin reversed gastroprotective effects of L-cysteine or H(2)S donors (NaHS or Lawesson`s reagent) in ethanol-induced macroscopic gastric damage. Likewise, in the presence of the TRPV1 antagonist capsazepine, the gastroprotective effects of L-cysteine, NaHS, or Lawesson`s reagent were also abolished. Our results suggest that H(2)S prevents ethanol-induced gastric damage. Although there are many mechanisms through which this effect can occur, our data support the hypothesis that the activation of K(ATP) channels and afferent neurons/TRPV1 receptors is of primary importance.
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Background. Cyclosporine A (CsA)-induced chronic nephrotoxicity is characterized by renal dysfunction and interstitial fibrosis. Early and progressive renal macrophage influx, correlating with latter interstitial fibrotic areas, has been associated with CsA treatment. This study investigated the role of macrophages, the nitric oxide (NO) pathway, and the oxidative stress on chronic CsA nephrotoxicity. Methods. The macrophages were depleted by clodronate liposomes. Animals were distributed into four groups: vehicle (olive oil for 21 days), CsA 7.5 mg/kg per day (21 days), CsA plus clodronate (5 mg/mL intraperitoneally on days -4, 1, 4, 11, and 18 of CsA treatment), or vehicle plus clodronate. On day 22, glomerular filtration rate, renal blood flow, renal tubulointerstitial fibrosis, CsA blood levels, serum malondialdehyde and renal tissue immunohistochemistry for macrophages, inducible NO synthase, transforming growth factor-beta, nuclear factor-k beta, alpha-smooth muscle actin, vimentin, and nitrotyrosine were assessed. Results. CsA-induced increase in the macrophage was prevented by clodronate. Macrophage depletion attenuated the reductions in the glomerular filtration rate and renal blood flow, the development of tubulointerstitial fibrosis, malondialdehyde increase and increases in nuclear factor-k beta, transforming growth factor-beta, vimentin, inducible NO synthase, and nitrotyrosine expression provoked by CsA. Clodronate did not affect alpha-smooth muscle actin expression and CsA blood levels. Conclusions. Renal macrophage influx plays an important role in CsA-induced chronic nephrotoxicity. The NO pathway and oxidative stress are likely mechanisms involved in the genesis of this form of renal injury.
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We investigated the influence of captopril (an angiotensin converting enzyme inhibitor) treatment during pregnancy and lactation period on hydromineral balance of the male adult offspring, particularly, concerning thirst and sodium appetite. We did not observe significant alterations in basal hydromineral (water intake, 0.3 M NaCl intake, volume and sodium urinary concentration) or cardiovascular parameters in adult male rats perinatally treated with captopril compared to controls. However, male offspring rats that perinatally exposed to captopril showed a significant attenuation in water intake induced by osmotic stimulation, extracellular dehydration and beta-adrenergic stimulation. Moreover, captopril treatment during perinatal period decreased the salt appetite induced by sodium depletion. This treatment also attenuated thirst and sodium appetite aroused during inhibition of peripheral angiotensin 11 generation raised by low concentration of captopril in the adult offspring. Interestingly. perinatal exposure to captopril did not alter water or salt intake induced by i.c.v. administration of angiotensin I or angiotensin II. These results showed that chronic inhibition of angiotensin converting enzyme during pregnancy and lactation modifies the regulation of induced thirst and sodium appetite in adulthood. (C) 2009 Elsevier Inc. All rights reserved.
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The role of GABA in the central processing of complex auditory signals is not fully understood. We have studied the involvement of GABA(A)-mediated inhibition in the processing of birdsong, a learned vocal communication signal requiring intact hearing for its development and maintenance. We focused on caudomedial nidopallium (NCM), an area analogous to parts of the mammalian auditory cortex with selective responses to birdsong. We present evidence that GABA(A)-mediated inhibition plays a pronounced role in NCM`s auditory processing of birdsong. Using immunocytochemistry, we show that approximately half of NCM`s neurons are GABAergic. Whole cell patch-clamp recordings in a slice preparation demonstrate that, at rest, spontaneously active GABAergic synapses inhibit excitatory inputs onto NCM neurons via GABA(A) receptors. Multi-electrode electrophysiological recordings in awake birds show that local blockade of GABA(A)-mediated inhibition in NCM markedly affects the temporal pattern of song-evoked responses in NCM without modifications in frequency tuning. Surprisingly, this blockade increases the phasic and largely suppresses the tonic response component, reflecting dynamic relationships of inhibitory networks that could include disinhibition. Thus processing of learned natural communication sounds in songbirds, and possibly other vocal learners, may depend on complex interactions of inhibitory networks.
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Cannabinoids have been shown to modulate central autonomic regulation and baroreflex control of blood pressure. Both CB1 and CB2 cannabinoid receptors have been described in the nucleus tractus solitarius (NTS), which receives direct afferent projections of cardiovascular reflexes. in the present study we evaluated the effects of WIN 55212-2 (WIN), a cannabinoid agonist, on fast neurotransmission in the NTS. We recorded spontaneous post-synaptic currents using the whole-cell configuration in NTS cells in brainstem slices from young rats (25-30 days old). Application of 5 mu M WIN inhibited the frequency of both glutamatergic and GABAergic sPSCs, without affecting their amplitudes. Effects of WIN were not blocked by application of the CB1 antagonist AM251, the CB2 antagonist AM630 or the varmiloid receptor TRPV1 antagonist AMG9810, suggesting that the effect of WIN is via a non-CB1 non-CB2 receptor. Neither the CB1/CB2 agonist HU210 nor the CB1 agonist ACPA affected the frequency of sPSCs. We conclude WIN inhibits the neurotransmission in the NTS of young rats via a receptor distinct from CB1 or CB2. (c) 2008 Elsevier B.V. All rights reserved.
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PURPOSE: To evaluate the advantages and disadvantages of the new low-addition (add) (+3.00 diopter [D]) ReSTOR multifocal IOL compared with the preceding ReSTOR model with +4.00 D add. SETTING: University Eye Hospital, Tuebingen, Germany. DESIGN: Comparative case series. METHODS: Patients with a +3.00 D or +4.00 D add multifocal IOL were examined for uncorrected and distance-corrected visual acuity at distance, intermediate, and near. A defocus profile was assessed, individual reading distance and the distance for lowest intermediate visual acuity were determined. Patient satisfaction was evaluated with a standardized questionnaire. Contrast sensitivity was tested under mesopic and photopic conditions. RESULTS: Uncorrected and distance-corrected intermediate visual acuities were statistically significantly better in the +3.00 D add group (24 eyes) than in the +4.00 D add group (30 eyes); distance and near visual acuities were not different between groups. The defocus profile significantly varied between groups. The +4.00 D add group had a closer reading distance (33.0 cm) than the +3.00 D add group (43.5 cm), a closer point of lowest intermediate visual acuity (65.8 cm versus 86.9 cm) and worse lowest intermediate visual acuity (20/59 +/- 4.5 letters [SD] versus 20/48 +/- 5.5 letters). Thus, patients in the +3.00 D add group reported being more satisfied with intermediate visual acuity. The +3.00 D add group reported more glare but less halos than the +4.00 D add group; contrast sensitivity was not different. CONCLUSION: The lower addition resulted in a narrower defocus profile, a farther reading distance, and better intermediate visual acuity and thus increased patient satisfaction.