163 resultados para ULTRASTRUCTURAL CHANGES
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Objective: To evaluate the effect of maternal oral hydration on amniotic fluid index (AFI) in pregnancies with fetal gastroschisis. Methods: AFI was evaluated at 24-hour intervals, during 4 consecutive days, under a continuous maternal oral water hydration regimen, in singleton pregnancies with isolated fetal gastroschisis. Results: Nine pregnancies were examined at a mean gestational age of 31.6 weeks (+/-1.4) and mean maternal daily oral water intake was 3,437 (+/-810) ml. Mean AFI on days 0-3 were 13.2 (+/-2.9), 14.8 (+/-3.3), 14.5 (+/-3.1) and 14.8 (+/-2.6), respectively. AFI on day 0 was significantly lower compared to all the other 3 days (p = 0.01 and 0.02). Significant correlation was found in relative difference in AFI between day 0 and day 1 and gestational age (r = -0.67, p = 0.05) and the amount of water intake in the previous 24 h (r = 0.76, p = 0.02). Conclusion: Maternal oral water hydration significantly increases AFI in pregnancies with isolated fetal gastroschisis. Copyright (C) 2010 S. Karger AG, Basel
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Background/Aims: To evaluate the behavior of glycosaminoglycans (GAGs) in rat gingiva and the effects of lack of sexual steroids and the hormonal therapy with estrogen and dexamethasone (DEX). Methods: 40 female rats were divided into four groups: GI: animals in permanent estrus; GII: ovariectomized (OVX) animals + vehicle; GIII: OVX animals treated with 17 beta-estradiol benzoate (10 mu g/kg), and GIV: OVX animals treated with 17 beta-estradiol benzoate (10 mu g/kg) + DEX (3 mg/kg). After treatment, the gingiva was removed and its GAGs content was evaluated by electronic microscopy after stained by cuprolinic blue technique. Results: The electron-microscopic data showed that low values of chondroitin sulfate were found in castrated animals (35.05 +/- 3.58%) compared to other groups (GI: 41.17 +/- 1.13; GIII: 48.04 +/- 2.60; GIV: 49.09 +/- 2.68%). In contrast, the amount of dermatan sulfate in GII (57.70 +/- 2.50%) was higher than in the other groups (GI: 46.12 +/- 1.30; GIII: 42.65 +/- 2.98; GIV: 42.68 +/- 5.43%). Conclusions: GAGs may be influenced by estradiol, and DEX did not seem to antagonize the role of estradiol in the GAGs of gingiva. The histotypical structure of gingiva is related to the amount of chondroitin sulfate. Consequently, the estrogen therapy may be important for gingival health. Copyright (C) 2007 S. Karger AG, Basel.
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Objective: The aim of this article is to propose an integrated framework for extracting and describing patterns of disorders from medical images using a combination of linear discriminant analysis and active contour models. Methods: A multivariate statistical methodology was first used to identify the most discriminating hyperplane separating two groups of images (from healthy controls and patients with schizophrenia) contained in the input data. After this, the present work makes explicit the differences found by the multivariate statistical method by subtracting the discriminant models of controls and patients, weighted by the pooled variance between the two groups. A variational level-set technique was used to segment clusters of these differences. We obtain a label of each anatomical change using the Talairach atlas. Results: In this work all the data was analysed simultaneously rather than assuming a priori regions of interest. As a consequence of this, by using active contour models, we were able to obtain regions of interest that were emergent from the data. The results were evaluated using, as gold standard, well-known facts about the neuroanatomical changes related to schizophrenia. Most of the items in the gold standard was covered in our result set. Conclusions: We argue that such investigation provides a suitable framework for characterising the high complexity of magnetic resonance images in schizophrenia as the results obtained indicate a high sensitivity rate with respect to the gold standard. (C) 2010 Elsevier B.V. All rights reserved.
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Abnormalities in fronto-limbic-striatal white matter (WM) have been reported in bipolar disorder (BD), but results have been inconsistent across studies. Furthermore, there have been no detailed investigations as to whether acute mood states contribute to microstructural changes in WM tracts. In order to compare fiber density and structural integrity within WM tracts between BD depression and remission, whole-brain fractional anisotropy (FA) and mean diffusivity (MD) were assessed in 37 bipolar I disorder (BD-I) patients (16 depressed and 21 remitted), and 26 healthy individuals with diffusion tensor imaging. Significantly decreased FA and increased MD in bilateral prefronto-limbic-striatal white matter and right inferior fronto-occipital, superior and inferior longitudinal fasciculi were shown in all BD-I patients versus controls, as well as in depressed BD-I patients compared to both controls and remitted BD-I patients. Depressed BD-I patients also exhibited increased FA in the ventromedial prefrontal cortex. Remitted BD-I patients did not differ from controls in FA or MD. These findings suggest that BD-I depression may be associated with acute microstructural WM changes.
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Background: Systemic sclerosis (SSc) is a multisystem disorder characterized by inflammation, fibrosis and vascular damage. The aim of this study was to evaluate the interactions between basement membrane disruption, endothelial injury and collagen V deposition on the vascular wall, as well as their association with pulmonary function tests in patients with SSc. Method: The endothelial apoptosis was assessed by TUNEL and electron microscopy, and quantified through the point-counting technique. To evaluate basement membrane integrity, laminin immunostaining and electron microscopy were used. Immunofluorescence and morphometric analysis were used to determine the amount of collagen V in the vascular walls in 23 open lung biopsies of patients with SSc without pulmonary hypertension. Normal lung tissue was obtained from five individuals who had died of traumatic injuries. Results: The apoptosis index in SSc was higher in the endothelial cells (13.83 +/- 6.83) when compared with the control (2.51 +/- 2.06) group (P < 0.001) and confirmed by electron microscopy. We observed an important disruption of the basement membrane on the vascular wall shown by discontinuous laminin immunostaining and electron microscopy. An increase in collagen V on the vascular wall of the SSc group was observed (45.28 +/- 13.21), when compared with control group (22.90 +/- 4.13, P < 0.001), and this difference was statistically significant. An inverse correlation was found between vital capacity, forced vital capacity, forced expiratory volume in 1 s, vascular collagen V and endothelial apoptosis (P < 0.05). Conclusions: We conclude that the endothelial apoptosis and vascular collagen V interaction reinforce the vascular pathway in the SSc pathogenesis. Further studies are needed to determine whether this relationship is causal or consequential. Please cite this paper as: Parra ER, Aguiar AC Jr, Teodoro WR, de Souza R, Yoshinari NH and Capelozzi VL. Collagen V and vascular injury promote lung architectural changes in systemic sclerosis. The Clinical Respiratory Journal 2009; 3: 135-142.
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Oral tolerance attenuates changes in in vitro lung tissue mechanics and extracellular matrix remodeling induced by chronic allergic inflammation in guinea pigs. J Appl Physiol 104: 1778-1785, 2008. First published April 3, 2008; doi:10.1152/japplphysiol.00830.2007.-Recent studies emphasize the presence of alveolar tissue inflammation in asthma. Immunotherapy has been considered a possible therapeutic strategy for asthma, and its effect on lung tissue had not been previously investigated. Measurements of lung tissue resistance and elastance were obtained before and after both ovalbumin and acetylcholine challenges. Using morphometry, we assessed eosinophil and smooth muscle cell density, as well as collagen and elastic fiber content, in lung tissue from guinea pigs with chronic pulmonary allergic inflammation. Animals received seven inhalations of ovalbumin (1-5 mg/ml; OVA group) or saline (SAL group) during 4 wk. Oral tolerance (OT) was induced by offering ad libitum ovalbumin 2% in sterile drinking water starting with the 1st inhalation (OT1 group) or after the 4th (OT2 group). The ovalbumin-exposed animals presented an increase in baseline and in postchallenge resistance and elastance related to baseline, eosinophil density, and collagen and elastic fiber content in lung tissue compared with controls. Baseline and post-ovalbumin and acetylcholine elastance and resistance, eosinophil density, and collagen and elastic fiber content were attenuated in OT1 and OT2 groups compared with the OVA group. Our results show that inducing oral tolerance attenuates lung tissue mechanics, as well as eosinophilic inflammation and extracellular matrix remodeling induced by chronic inflammation.
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Free fatty acids (FFAs) have been shown to produce alteration of heart rate variability (HRV) in healthy and diabetic individuals. Changes in HRV have been described in septic patients and in those with hyperglycemia and elevated plasma FFA levels. We studied if sepsis-induced heart damage and HRV alteration are associated with plasma FFA levels in patients. Thirty-one patients with sepsis were included. The patients were divided into two groups: survivors(n = 12) and nonsurvivors (n = 19). The following associations were investigated: (a) troponin I elevation and HRV reduction and (b) clinical evolution and HRV index, plasma troponin, and plasma FFA levels. Initial measurements of C-reactive protein and gravity Acute Physiology and Chronic Health Evaluation scores were similar in both groups. Overall, an increase in plasma troponin level was related to increased mortality risk. From the first day of study, the nonsurvivor group presented a reduced left ventricular stroke work systolic index and a reduced low frequency (LF) that is one of HRV indexes. The correlation coefficient for LF values and troponin was r(2) = 0.75 (P < 0.05). All patients presented elevated plasma FFA levels on the first day of the study (5.11 +/- 0.53 mg/mL), and this elevation was even greater in the nonsurvivor group compared with the survivors (6.88 +/- 0.13 vs. 3.85 +/- 0.48 mg/mL, respectively; P < 0.05). Cardiac damage was confirmed by measurement of plasma troponin I and histological analysis. Heart dysfunction was determined by left ventricular stroke work systolic index and HRV index in nonsurvivor patients. A relationship was found between plasma FFA levels, LFnu index, troponin levels, and histological changes. Plasma FFA levels emerged as possible cause of heart damage in sepsis.
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Objective: Uncertainties about the numerous degrees of freedom in ventilator settings leave many unanswered questions about the biophysical determinants of lung injury. We investigated whether mechanical ventilation with high air flow could yield lung mechanical stress even in normal animals. Design. Prospective, randomized, controlled experimental study. Setting: University research laboratory. Subjects. Thirty normal male Wistar rats (180-230 g). Interventions: Rats were ventilated for 2 hrs with tidal volume of 10 mL/kg and either with normal inspiratory air flow (V`) of 10 mL/s (F10) or high V` of 30 mL/s (F30). In the control group, animals did not undergo mechanical ventilation. Because high flow led to elevated respiratory rate (200 breaths/min) and airway peak inspiratory pressure (PIP,aw = 17 cm H2O), two additional groups were established to rule out the potential contribution of these variables: a) normal respiratory rate = 100 breaths/min and V` = 30 mL/sec; and b) PIP,aw = 17 cm H2O and V` 10 mL/sec. Measurements and Main Results: Lung mechanics and histology (light and electron microscopy), arterial blood gas analysis, and type III procollagen messenger RNA expression in lung tissue were analyzed. Ultrastructural microscopy was similar in control and F10 groups. High air flow led to increased lung plateau and peak pressures, hypoxemia, alveolar hyperinflation and collapse, pulmonary neutrophilic infiltration, and augmented type III procollagen messenger RNA expression compared with control rats. The reduction of respiratory rate did not modify the morphofunctional behavior observed in the presence of increased air flow. Even though the increase in peak pressure yielded mechanical and histologic changes, type III procollagen messenger RNA expression remained unaltered. Conclusions: Ventilation with high inspiratory air flow may lead to high tensile and shear stresses resulting in lung functional and morphologic compromise and elevation of type III procollagen messenger RNA expression.
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This work aimed to investigate some aspects related to the pathogenicity of Lechiguana, a bovine fibroproliferative lesion characterized by rapid collagen accumulation. Light and transmission electron microscopy and in situ hybridization studies were performed in order to elucidate the fibrogenic activity of this lesion. The characterization of fibroblastic plasticity in the lesion was done by immunohistochemical study for alpha-smooth-muscle cell actin. The ovoid-shaped cells presented positive reaction for alpha-smooth-muscle cell actin in their cytoplasm and, at the electron-microscopic level demonstrated basal lamina-like material adjacent to the external surface and collagen fibrils that corresponded to a cell population phenotypically similar to the myofibroblast. We also investigated alpha 1 collagen type I mRNA at different times of evolution of Lechiguana lesions, using isotopic and non-isotopic in situ hybridization. The results strongly suggest the involvement of a myofibroblast-like cell population that expresses mRNA for type I collagen and is probably associated with the increase of collagen deposition.
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Several epidemiological studies have linked particulate matter exposure to numerous adverse health effects on the respiratory, cardiovascular, and reproductive systems (Braga et al., 1999; Zanobetti et al., 2000; Anderson et al., 2001; Farhat et al., 2005). More recently, ambient levels of black carbon were associated to impaired cognitive function in children (Suglia et al., 2008), suggesting that the central nervous system (CNS) may be a target of air pollutants. The present study was conducted to (a) determine whether chronic residual oil fly ash (ROFA) exposure promotes behavioral changes and lipid peroxidation in rat brain areas, and (b) determine whether N-acetylcysteine (NAC), a general antioxidant, prevents these effects. Forty-five-day-old male Wistar rats were exposed or not to ROFA by intranasal instillation and were treated or not with NAC (150 mg/kg) ip for 30 days. One day later, rats were submitted to the open field test to evaluate the motor/exploratory activities and emotionality followed by decapitation. Striatum and cerebellum were dissected to determine lipid peroxidation by the accumulation of thiobarbituric acid-reactive substances (TBARS). ROFA instillation induced an increase in lipid peroxidation level in striatum (p = .033) and cerebellum (p = .030), as compared with the control group. NAC treatment blocked these changes. ROFA promoted a decrease in the frequency of peripheral walking (p = .006) and a decrease in exploration (p = .001), which were not blocked by N-acetylcysteine. The present study provides evidence that toxic particles, administered by the respiratory route, induce oxidative stress in structures of the central nervous system, as well as behavioral alterations. The administration of NAC reduces lipid peroxidation at the striatum and cerebellum levels, but does not influence behavioral disturbances.
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Although it is currently believed that the vocal ligament of humans undergoes considerable development postnatally, there is no consensus as to the age at which it first emerges. In the newborn infant, the lamina propria has been described as containing a sparse collection of relatively unorganized fibres. In this study we obtained larynges from autopsy of human fetuses aged 7-9 months and used light and electron microscopy to study the collagenous and elastic system fibres in the lamina propria of the vocal fold. Collagen fibres were viewed using the Picrosirius polarization method and elastic system fibres were stained using Weigert`s resorcin-fuchsin after oxidation with oxone. The histochemical and electron microscopic observations were consistent, showing collagen populations with an asymmetric distribution across different compartments of the lamina propria. In the central region, the collagen appeared as thin, weakly birefringent, greenish fibres when viewed using the Picrosirius polarization method, whereas the superficial and deep regions contained thick collagen fibres that displayed a strong red or yellow birefringence. These findings suggest that the thin fibres in the central region consist mainly of type III collagen, whereas type I collagen predominates in the superficial and deep regions, as has been reported in studies of adult vocal folds. Similarly, elastic system fibres showed a differential distribution throughout the lamina propria. Their distribution pattern was complementary to that of collagen fibres, with a much greater density of elastic fibres apparent in the central region than in the superficial and deep regions. This distribution of collagen and elastic fibres in the fetal vocal fold mirrors that classically described for the adult vocal ligament, suggesting that a vocal ligament has already begun to develop by the time of birth. The apparently high level of organization of connective tissue components in the newborn is in contrast to current hypotheses that argue that the mechanical stimuli of phonation are essential to the determination of the layered structure of the lamina propria and suggests that genetic factors may play a more significant role in the development of the vocal ligament than previously believed.
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Storage at low temperature is the most frequently used method to extend the shelf life of banana fruit, and is fundamental for extended storage and transport over long distances. However, storage and transport conditions must be carefully controlled because of the high susceptibility of many commercial cultivars to chilling injury. The physiological behavior of bananas at low temperatures has been studied to identify possible mechanisms of resistance to chilling injury. The aim of this work was to evaluate differences in the starch-to-sucrose metabolism of a less tolerant and susceptible (Musa acuminata, AAA cv. Nanicao) and a more tolerant (M. acuminata x Musa balbusiana, AAB, cv. Prata) banana cultivar to chilling injury. Fruits of these cultivars were stored in chambers at 13 degrees C for 15 d, at which point they were transferred to 19 degrees C, where they were left until complete ripening. The low temperature induced significant changes in the metabolism of starch and sucrose in comparison to fruit ripened only at 19 degrees C. The sucrose accumulation was slightly higher in cv. Prata, and different patterns of starch degradation, sucrose synthesis, activity and protein levels of the alpha-and beta-amylases, starch phosphorylase, sucrose synthase and sucrose phosphate synthase were detected between the cultivars. Our results suggest that starch-to-sucrose metabolism is likely part of the mechanism for cold acclimation in banana fruit, and the cultivar-dependent differences contribute to their ability to tolerate cold temperatures. (C) 2011 Elsevier B.V. All rights reserved.
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While conventional antidepressants benefit many patients with major depressive disorder (MDD), as much as eight to 12 weeks can elapse before significant improvements in depressive symptoms are seen. Treatments that act more rapidly in MDD are urgently needed. Sleep deprivation (SD) has been shown to produce a rapid antidepressant response within one day in 50-60% of patients with MDD; thus, identifying its antidepressant mechanism may contribute to the development of antidepressants that act more rapidly. The present study evaluated the effects of 39 h of SD on mood, as well as on plasma levels of brain derived neurotrophic factor (BDNF) and vascular endothelial growth factor (VEGF) in patients with MDD. After a drug-free period of at least two weeks, 11 patients (6 males, 5 females; ages 25-62) who met DSM-IV criteria for MDD underwent total SD. Plasma samples for BDNF and VEGF assays were collected on Days 1 (baseline) and 2. The six-item Hamilton Rating Scale for Depression (HAMD-6) was the primary outcome measure. HAMD-6 scores decreased significantly after SD (Day 2). SD was negatively correlated with change in HAMD-6 score and change in VEGF levels, indicating that as depression scores decreased following SD, VEGF plasma levels increased. In contrast, SD did not alter plasma BDNF concentrations, nor was an association found between BDNF levels and clinical improvement on the HAMD-6. These results suggest that SD is associated with mood-related changes in plasma VEGF levels, but not plasma BDNF levels. Further studies using larger sample sizes are needed to confirm these preliminary findings. Published by Elsevier Inc.
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Purpose: Because of the controversial biologic tolerance and management, retained intraorbital metallic foreign body (RIMFb) poses a formidable challenge to surgeons. Besides location of the foreign body, indications for surgical management include neurologic injury, mechanical restriction of the eye movement, and development of local infection or draining fistula. The authors describe an unusual case of spontaneous migration of a RIMFb. Methods: A 26-year-old man had a gunshot injury on the left orbit. The patient was initially managed conservatively because of the posterior position of the bullet fragment. Thereafter, because of the clinical impairments and anterior migration of projectile, surgical treatment was considered. Results: Spontaneous anterior migration has led to mechanical disturbances and inflammatory complications that comprise explicit surgical indications for removal. The patient underwent surgery with complete relief of symptoms. We suppose that extrinsic ocular muscles might play a role in shifting large RIMFb over time, leading to change in the management strategies. Conclusions: Spontaneous migration of RIMFb is a rare clinical situation that can lead to pain, local deformity, as well as changes in the management strategies of the affected patients even in the late phase of follow-up.
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Objectives We studied the relationship between changes in body composition and changes in blood pressure levels. Background The mechanisms underlying the frequently observed progression from pre-hypertension to hypertension are poorly understood. Methods We examined 1,145 subjects from a population-based survey at baseline in 1994/1995 and at follow-up in 2004/2005. First, we studied individuals pre-hypertensive at baseline who, during 10 years of follow-up, either had normalized blood pressure (PreNorm, n = 48), persistently had pre-hypertension (PrePre, n = 134), or showed progression to hypertension (PreHyp, n = 183). In parallel, we studied predictors for changes in blood pressure category in individuals hypertensive at baseline (n = 429). Results After 10 years, the PreHyp group was characterized by a marked increase in body weight (+5.71% [95% confidence interval (CI): 4.60% to 6.83%]) that was largely the result of an increase in fat mass (+17.8% [95% CI: 14.5% to 21.0%]). In the PrePre group, both the increases in body weight (+1.95% [95% CI: 0.68% to 3.22%]) and fat mass (+8.09% [95% CI: 4.42% to 11.7%]) were significantly less pronounced than in the PreHyp group (p < 0.001 for both). The PreNorm group showed no significant change in body weight (-1.55% [95% CI: -3.70% to 0.61%]) and fat mass (+0.20% [95% CI: -6.13% to 6.52%], p < 0.05 for both, vs. the PrePre group). Conclusions After 10 years of follow-up, hypertension developed in 50.1% of individuals with pre-hypertension and only 6.76% went from hypertensive to pre-hypertensive blood pressure levels. An increase in body weight and fat mass was a risk factor for the development of sustained hypertension, whereas a decrease was predictive of a decrease in blood pressure. (J Am Coll Cardiol 2010; 56: 65-76) (C) 2010 by the American College of Cardiology Foundation