987 resultados para EFFECTIVE-MASS APPROXIMATION


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Emotional liability and mood dysregulation characterize bipolar disorder (BID), yet no study has examined effective connectivity between parahippocampal gyrus and prefrontal cortical regions in ventromedial and dorsal/lateral neural systems subserving mood regulation in BD. Participants comprised 46 individuals (age range: 18-56 years): 21 with a DSM-IV diagnosis of BID, type I currently remitted; and 25 age- and gender-matched healthy controls (HC). Participants performed an event-related functional magnetic resonance imaging paradigm, viewing mild and intense happy and neutral faces. We employed dynamic causal modeling (I)CM) to identify significant alterations in effective connectivity between BD and HC. Bayes model selection was used to determine the best model. The right parahippocampal gyrus (PHG) and right subgenual cingulate gyrus (sgCG) were included as representative regions of the ventromedial neural system. The right dorsolateral prefrontal cortex (DLPFC) region was included as representative of the dorsal/lateral neural system. Right PHG-sgCG effective connectivity was significantly greater in BD than HC, reflecting more rapid, forward PHG-sgCG signaling in BD than HC. There was no between-group difference in sgCG-DLPFC effective connectivity. In BD, abnormally increased right PHG-sgCG effective connectivity and reduced right PHG activity to emotional stimuli suggest a dysfunctional ventromedial neural system implicated in early stimulus appraisal, encoding and automatic regulation of emotion that may represent a pathophysiological functional neural mechanism for mood dysregulation in BD. (C) 2009 Elsevier Ireland Ltd. All rights reserved.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Background: Bipolar disorder is frequently misdiagnosed as major depressive disorder, delaying appropriate treatment and worsening outcome for many bipolar individuals. Emotion dysregulation is a core feature of bipolar disorder. Measures of dysfunction in neural systems supporting emotion regulation might therefore help discriminate bipolar from major depressive disorder. Methods: Thirty-one depressed individuals-15 bipolar depressed (BD) and 16 major depressed (MDD), DSM-IV diagnostic criteria, ages 18-55 years, matched for age, age of illness onset, illness duration, and depression severity-and 16 age- and gender-matched healthy control subjects performed two event-related paradigms: labeling the emotional intensity of happy and sad faces, respectively. We employed dynamic causal modeling to examine significant among-group alterations in effective connectivity (EC) between right- and left-sided neural regions supporting emotion regulation: amygdala and orbitomedial prefrontal cortex (OMPFC). Results: During classification of happy faces, we found profound and asymmetrical differences in EC between the OMPFC and amygdala. Left-sided differences involved top-down connections and discriminated between depressed and control subjects. Furthermore, greater medication load was associated with an amelioration of this abnormal top-down EC. Conversely, on the right side the abnormality was in bottom-up EC that was specific to bipolar disorder. These effects replicated when we considered only female subjects. Conclusions: Abnormal, left-sided, top-down OMPFC-amygdala and right-sided, bottom-up, amygdala-OMPFC EC during happy labeling distinguish BD and MDD, suggesting different pathophysiological mechanisms associated with the two types of depression.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Papaya (Carica papaya) is a climacteric fruit that undergoes dramatic pulp softening. Fruits sampled at three different conditions (natural ripening or after exposition to ethylene or 1-methylcyclopropene) were used for the isolation of cell wall polymers to find changes in their degradation pattern. Polymers were separated according to their solubility in water, CDTA, and 4 M alkali, and their monosaccharide compositions were determined. Water-soluble polymers were further characterized, and their increased yields in control and ethylene-treated fruit, in contrast to those that were treated with 1-MCP, indicated a strong association between fruit softening and changes in the cell wall water-soluble polysaccharide fraction. The results indicate that the extensive softening in the pulp of ripening papayas is a consequence of solubilization of large molecular mass galacturonans from the pectin fraction of the cell wall. This process seems to be dependent on the levels of ethylene, and it is likely that the releasing of galacturonan chains results from an endo acting polygalacturonase.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Rationale: Upper airway muscle function plays a major role in maintenance of the upper airway patency and contributes to the genesis of obstructive sleep apnea syndrome (OSAS). Preliminary results suggested that oropharyngeal exercises derived from speech therapy may be an effective treatment option for patients with moderate OSAS. Objectives: To determine the impact of oropharyngeal exercises in patients with moderate OSAS. Methods: Thirty-one patients with moderate OSAS were randomized to 3 months of daily (similar to 30 min) sham therapy (n = 15, control) or a set of oropharyngeal exercises (n = 16), consisting of exercises involving the tongue, soft palate, and lateral pharyngeal wall. Measurements and Main Results: Anthropometric measurements, snoring frequency (range 0-4), intensity (1-3), Epworth daytime sleepiness (0-24) and Pittsburgh sleep quality (0-21) questionnaires, and full polysomnography were performed at baseline and at study conclusion. Body mass index and abdominal circumference of the entire group were 30.3 +/- 3.4 kg/m(2) and 101.4 +/- 9.0 cm, respectively, and did not change significantly over the study period. No significant change occurred in the control group in all variables. In contrast, patients randomized to oropharyngeal exercises had a significant decrease (P < 0.05) in neck circumference (39.6 +/- 3.6 vs. 38.5 +/- 4.0 cm), snoring frequency (4 [4-4] vs. 3 [1.5-3.5]), snoring intensity (3 [3-4] vs. 1 [1-2]), daytime sleepiness (14 +/- 5 vs. 8 +/- 6), sleep quality score (10.2 +/- 3.7vs. 6.9 +/- 2.5), and OSAS severity (apnea-hypopnea index, 22.4 +/- 4.8 vs. 13.7 +/- 8.5 events/h). Changes in neck circumference correlated inversely with changes in apnea-hypopnea index (r = 0.59; P < 0.001). Conclusions: Oropharyngeal exercises significantly reduce OSAS severity and symptoms and represent a promising treatment for moderate OSAS. Clinical trial registered with www.clinicaltrials.gov (NCT 00660777).

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The aim of this study was to evaluate the efficacy of a cost-effective intra-oral appliance for obstructive sleep apnea syndrome built into a large teaching hospital. Out of 20 evaluated and treated patients, 14 concluded the study: eight men and six women, with a mean age of 42-46 (mean + SD) years and mean body mass index of 27.66. Inclusion criteria were mild or moderate apnea-hypopnea index (AHI) according to a polysomnographic study. All patients were treated with the monobloco intra-oral appliance. They were then submitted to a follow-up polysomnographic study after 60 days using the appliance. An orofacial clinical evaluation was carried out with the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) questionnaire and with clinical evaluation questionnaire devised by the Orofacial Pain Team before and 60 days after fitting the intra-oral appliance. The AHI showed a statistically meaningful (p = 0.002) reduction from 15.53 to 7.82 events per hour, a non-statistically significant oxygen saturation increase from 83.36 to 84.86 (p = 0.09), and Epworth`s sleepiness scale reduction from 9.14 to 6.36 (p = 0.001). Three patients did not show any improvement. The most common side effect during the use of the appliance/device was pain and facial discomfort (28.57%), without myofascial or temporomandibular joint pain as evaluated by the RDC/TMD questionnaire. The intra-oral device produced a significant reduction of the apnea-hypopnea index during the study period with the use of the monobloco intra-oral appliance. Patients did not show prior myofascial pain or 60 days after use of the intra-oral appliance.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Objective We characterized the impact of the metabolic syndrome (MetS) and its components on cardiovascular adverse events in patients with symptomatic chronic multivessel coronary artery disease, which have been followed prospectively for 2 years. Methods Patients enrolled in the MASS II study were evaluated for each component of the MetS, as well as the full syndrome. Results The criteria for MetS were fulfilled in 52% of patients. The presence of MetS (P < 0.05), glucose intolerance (P=0.007), and diabetes (P=0.04) was associated with an increased mortality in our studied population. Moreover, despite a clear tendency for each of its components to increase the mortality risk, only the presence of the MetS significantly increased the risk of mortality among nondiabetic study participants in a multivariate model (P=0.03, relative risk 3.5, 95% confidence interval 1.1-6). Finally, MetS was still associated with increased mortality even after adjustment for diabetes status. These results indicate a strong and consistent relationship of the MetS with mortality in patients with stable coronary artery disease. Conclusion Although glucose homeostasis seems to be the major force driving the increased risk of MetS, the operational diagnosis of MetS still has information for stratifying patients when diabetes information is taken into account.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Objective: The aim of the study was to evaluate clinical and laboratorial features of 1234 patients with different etiologies of hyper-prolactinemia, as well as the response of 388 patients with prolactinomas to dopamine agonists. Design, setting, and patients: A total of 1234 hyperprolactinemic patients from 10 Brazilian endocrine centers were enrolled in this retrospective study. Main outcome measure: PRL measurement, thyroid function tests, and screening for macroprolactin were conducted. Results: Patients were subdivided as follows: 56.2% had prolactinomas, 14.5% drug-induced hyperprolactinemia, 9.3% macroprolactinemia, 6.6% non-functioning pituitary adenomas, 6.3% primary hypothyroidism, 3.6% idiopathic hyperprolactinemia, and 3.2% acromegaly. Clinical manifestations were similar irrespective of the etiology of the hyperprolactinemia. The highest PRL levels were observed in patients with prolactinomas but there was a great overlap in PRL values between all groups. However, PRL>500 ng/ml allowed a clear distinction between prolactinomas and the other etiologies. Cabergoline (CAB) was more effective than bromocriptine (BCR) in normalizing PRL levels (81.9% vs 67.1%, p<0.0001) and in inducing significant tumor shrinkage and complete disappearance of tumor mass. Drug resistance was observed in 10% of patients treated with CAB and in 18.4% of those that used BCR (p=0.0006). Side-effects and intolerance were also more common in BCR-treated patients. Conclusion: Prolactinomas, drug-induced hyperprolactinemia, and macroprolactinemia were the 3 most common causes of hyperprolactinemia. Although PRL levels could not reliably define the etiology of hyperprolactinemia, PRL values >500 ng/ml were exclusively seen in patients with prolactinomas. CAB was significantly more effective than BCR in terms of prolactin normalization, tumor shrinkage, and tolerability.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Background: A 150 cm(3) pear-shaped gastric balloon with a 30 cm-long duodenal stem and a 7 g metallic weight at its distal end was designed and developed to facilitate weight loss by (a) delaying gastric emptying thus enhancing interprandial satiety, and (b) stimulating antral and duodenal receptors of satiation. Methods: Twenty-six patients (body mass index of 29 to 40 kg/m(2)) who failed to lose weight despite dietary intervention underwent endoscopic implantation of the balloon device. Patients were monitored for tolerance to the balloon, complications, weight loss, and compliance with a restricted caloric intake. Results: Six men and 20 women with a median body weight of 93.0kg (range, 73.5 to 119.9), median body mass index 34.3 kg/m(2) (range, 28.8 to 39.5) underwent balloon implantation for a median period of 4.0 months (range, 0.75 to 6.0). Twenty-two patients successfully complied with a 1250 to 1500 kcal daily diet restriction during the study period. Median weight reduction was 6.5 kg (range, 3.7 to 19.9). Patients with initial body weight of > 90 kg tended to loose more weight (8.1 kg) than patients weighing < 90 kg (4.5 kg) (P = 0.14). Nine patients with dwell times of 6 months lost 11.5 +/- 4.6 kg. The balloon malfunctioned in 4 patients (in I patient, the balloon leaked spontaneously but remained in the stomach and in 3 patients, the balloon migrated distally). Conclusions: Our novel balloon device may be effective in inducing weight loss by promoting compliance with a restricted caloric intake and is well tolerated due to its small size. Complications resulted from balloon rupture, which can be easily prevented by enhancements in design and use of alternative materials.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Central Nervous System disorders may cause important functional unbalance in the maintenance of balance and posture. There is no effective rehabilitation for these symptoms until now. Objective: The aim of this paper is to evaluate the use of tongue electrotactile stimulation on patients with central imbalance using BrainPort. Materials and Methods: This is a prospective case series study. We evaluated 8 patients with central imbalance, 6 men and 2 women, with mean age of 67.75 years. The patients were submitted to Computed Dynamic Posturography (CDP) and then received 18 sessions of electrotactile stimulation by BrainPort (R) device for 20 minutes, twice a day. Then they were submitted to a new CDP test and to a self-perception scale to assess symptom remission, partial improvement and no improvement at all. Results: 75% of the patients reported being more stable. There was no improvement in the balance control of the mass center in these patients. Conclusion: The patients were able to use the electrotactile stimulus to improve their balance control.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Introduction. Lung transplantation has become the mainstay therapy for patients with end-stage lung disease refractory to medical management. However, the number of patients listed for lung transplantation largely exceeds available donors. The study of lung preservation requires accurate, cost-effective small animal models. We have described a model of ex vivo rat lung perfusion using a commercially available system. Methods. Male Wistar rats weighing 250 g-300 g were anesthetized with intraperitoneal sodium thiopental (50 mg/kg body weight). The surgical technique included heart-lung block extraction, assembly, and preparation for perfusion and data collection. We used an IL-2 Isolated Perfused Rat or Guinea Pig Lung System (Harvard Apparatus, Holliston, Mass, United States; Hugo Sachs Elektronik, Alemanha). Results. Preliminary results included hemodynamic and pulmonary mechanics data gathered in the experiments. Conclusion. The isolated rat lung perfusion system is a reliable method to assess lung preservation.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Objective: To study the influence of low power GaAsAl laser irradiation on the regeneration of a peripheral nerve, following a controlled crush injury. Material and methods: The right common fibular nerve of 30 Wistar rats was submitted to a crush injury with an adjustable load forceps (5 000 g, 10 minutes of application). The animals were divided into three groups (n=10), according to the postoperative procedure (no irradiation; sham irradiation; effective irradiation). Laser irradiation (830 nm wave-length; 100 mW emission power; continuous mode; 140 J/cm(2)) was started on the first postoperative day and continued over 21 consecutive days. Body mass, time spent on the walking track and functional peroneal index (PFI) were analyzed based on the hind footprints, both preoperatively and on the 21st postoperative day. Results: Walking time and PFI significantly improved in the group that received effective laser irradiation, despite the significant gain in body mass between the pre- and post-operative periods. Conclusion: Low Power GaAsAl laser irradiation, with the parameters used in our study, accelerated and improved fibular nerve regeneration in rats.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Objectives The purpose of the present work was to characterize file pharmacological profile of different L. alba chemotypes and to correlate the obtained data to the presence of chemical constituents detected by phytochemical analysis. Methods Essential oils from each L. alba chemotype (LP1-LP7) were characterized by gas chromatography-mass spectrometry (GC-MS) and extracted non-volatile compounds were analysed by HPLC and GC-MS. The anticonvulsant actions of file extracted compounds were studied in pentylenetetrazole-induced clonic seizures in mice and then effect oil motor coordination was studied using the rota-rod test in rats. The synaptosomes and synaptic membranes of the rats were examined for the influence of LP3 chemotype extract oil GABA uptake and binding experiments. Key findings Behavioural parameters encompassed by the pentylenetetrazole test indicated that 80% ethanolic extracts of LP1, LP3 and LP6 L. alba chemotypes were more effective as anticonvulsant agents. Neurochemical assays using synaptosomes and synaptic membranes showed that L. alba LP3 chemotype 80% ethanolic extract inhibited GABA uptake and GABA binding ill a dose-dependent manner. HPLC analysis showed that LP1, LP3 and LP6 80% ethanolic extracts presented a similar profile of constituents, differing from those seen in LP2, LP4, LP5 and LP7 80% ethanolic extracts, which exhibited no anticonvulsant effect. GC-MS analysis indicated the Occurrence of phenylpropanoids in methanolic fractions obtained from LP1, LP3 and LP6 80% ethanolic extracts and also the accumulation of inositol and flavonoids in hydroalcoholic fractions. Conclusions Our results suggest that the anticonvulsant properties shown by L. alba might be correlated to the presence of it complex of non-volatile Substances (phenylpropanoids, flavonoids and/or inositols), and also to the volatile terpenoids (beta-myrcene, citral, limonene and carvone), which have been previously Validated as anticonvulsants.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Neutrophilic granulocytes play a major role in the initiation and resolution of the inflammatory response, and demonstrate significant transcriptional and translational activity. Although much was known about neutrophils prior to the introduction of proteomics, the use of MS-based methodologies has provided an unprecedented tool to confirm and extend previous findings. In the present study, we performed a Gel-LC-MS/MS analysis of neutrophil detergent insoluble and whole cell lysate fractions of resting neutrophils. We achieved a set of identifications through the use of high-resolution mass spectrometry and validation of its data. We identified a total of 1249 proteins with a wide range of intensities from both detergent-insoluble and whole cell lysate fractions, allowing a mapping of proteins such as those involved in intracellular transport (Rab and Sec family proteins) and cell signaling (S100 proteins). These results represent the most comprehensive proteomic characterization of resting human neutrophils to date, and provide important information relevant for further studies of the immune system in health and disease. The methods applied here can be employed to help us understand how neutrophils respond to various physiologic and pathophysiologic conditions and could be extended to protein quantitation after cell activation.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Quartz Crystal Microbalance (QCM) was used to monitor the mass changes on a quartz crystal surface containing immobilized lectins that interacted with carbohydrates. The strategy for lectin immobilization was developed on the basis of a multilayer system composed of Au-cystamine-glutaraldehyde-lectin. Each step of the immobilization procedure was confirmed by FTIR analysis. The system was used to study the interactions of Concanavalin A (ConA) with maltose and Jacalin with Fetuin. The real-time binding of different concentrations of carbohydrate to the immobilized lectin was monitored by means of QCM measurements and the data obtained allowed for the construction of Langmuir isotherm curves. The association constants determined for the specific interactions analyzed here were (6.4 +/- 0.2) X 10(4) M-1 for Jacalin-Fetuin and (4.5 +/- 0.1) x 10(2) M-1 for ConA-maltose. These results indicate that the QCM constitutes a suitable method for the analysis of lectin-carbohydrate interactions, even when assaying low molecular mass ligands such as disaccharides. Published by Elsevier B.V.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Background. Bilioduodenal (BD) and biliojejunal (BJ) derivation induce enterobiliary reflux and bile stasis. Decompression of the excluded loop of the Roux-en-Y (BJD) was proposed to minimize these effects. The aim of this study was to compare the influence of these three modalities of biliary bypass on hepatic lesion repair in rats with secondary biliary fibrosis. Materials and Methods. Rats with 15 d of biliary obstruction underwent BD, BJ, and BJD drainage and were compared with a group submitted to simulated operation (SO) and biliary obstruction (CBO). The serum values of total and fractional bilirubin, alkaline phosphatase (ALP), and aminotransferases (AST and ALT), as well as hepatobiliointestinal excretion determined with (99m)Tc-Disida, were used for comparison. In addition, we used morphometric analyses to estimate the mass of the hepatocytes, bile ducts, and liver fibrosis. We also counted hepatic stellate cells (SC). Results. For each of the three modalities of biliary drainage, there were significant reductions in bilirubin, AST, ALP, and the number of SCs. The recovery of the estimated mass of all histologic components occurred only after BJ and BJD; in the BD group, the estimated hepatocyte mass was reduced compared with the SO group. The residual hepatic radioactivity of (99m)Tc-Disida was greater in the BJD group than in the SO group. Conclusions. The interposition of the jejunal loop between the biliary tree and the intestine may slow hepatobiliary clearance of radioactivity, even though it provides the resolution of cholestasis and is effective in recovering from hepatic lesions. (C) 2011 Elsevier Inc. All rights reserved.