984 resultados para frequency changes


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Depressed patients have reduced glucocorticoid receptor (GR) function, as demonstrated by resistance to the suppressive effects of the synthetic glucocorticoid hormone, and GR agonist, dexamethasone. We have developed a suppressive test with prednisolone, a synthetic glucocorticoid that is similar to cortisol in its pharmacodynamics and pharmacokinetics, and binds to both the GR and the mineralocorticoid receptor (MR). We have found that depressed patients suppress normally to prednisolone, unless they are particularly non-responsive to treatment. In the present study, we evaluated 28 inpatients with treatment-resistant depression (TRD), and compared salivary cortisol secretion (at 0900 h, 1200 h and 1700 h) after placebo or after prednisolone (5 mg), before and after an inpatient treatment admission. Half of the patients (n = 14) reached treatment response. When comparing the assessment between admission and discharge, cortisol output after placebo fell (-26% of area under the curve; p = 0.024) while the output after prednisolone did not change. Moreover, there was no change in the response to prednisolone (percentage suppression) between admission at discharge, and this was not influenced by treatment response. Finally, we could confirm and extend our previously published data with prednisolone (5 mg), showing that depressed patients (n = 12) and controls (n = 12) suppressed equally to both 5 and 10 mg doses of prednisolone. This study suggests that the response to prednisolone is similar in depressed patients and controls at different doses of prednisolone, and does not change with symptomatic improvement. This is in contrast with findings, from us and others, using other measures of hypothalamic-pituitary-adrenal axis function, such as basal cortisol levels or the response to dexamethasone. Thus, we propose that the prednisolone suppression test may offer specific biological and clinical information, related to its action at both the GR and the MR. (C) 2010 Elsevier Ltd. All rights reserved.

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Adjustments during postural control have been recognized in the process of the integration of movement and cognition. The objective of the present work was to describe postural changes and to verify if there is a correlation between postural adjustment and attention span in 7-month-old infants during 1 min of viewing an animated puppet. Method: Twenty-nine healthy infants (14 males) born from 31 to 39 weeks (median 36) were placed in a prone position and filmed watching a puppet during I min. The analysis of the images allowed us to catalogue the changes in position, the frequency of these changes, and the attention span. The following items were quantified: total number of infant positions, positions with weight transfer, changes in support, axis, decubitus, trunk and cervical movements, timing and pauses in visual attention. Results: Twenty-one infants stayed in the prone position during most of the recording, and eight chose sitting position before starting the session. Two groups were studied according to the main position throughout the filming, one in prone and the other in sitting positions, although they could rolling or crawling. For prone group the attention span was positively correlated with the number of positions with weight transfer (r = 0.53, p = 0.04), negatively correlated with trunk movements (r = -0.63, p = 0.01), and not correlated with birth or current weight. This work suggests that changes in the trunk movements and weight transfer are different traits related to the attention in 7-month-old infants. (C) 2008 Elsevier B.V.. All rights reserved.

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Background. Morphological and dentofacial alterations have been attributed to impaired respiratory function. Objective. To examine the influence of mouth breathing (MB) on children facial morphology before and after adenoidectomy or adenotonsillectomy. Methods. Thirty-three MB children who restored nasal breathing (NB) after surgery and 22 NB children were evaluated. Both groups were submitted to lateral cephalometry, at time 1 (T1) before and at time 2 (T2) 28 months on average postoperatively. Results. Comparison between the MB and NB groups at T1 showed that mouth breathers had higher inclination of the mandibular plane; more obtuse gonial angle; dolichofacial morphology; and a decrease in the total and inferior posterior facial heights. Twenty-eight months after the MB surgical intervention, they still presented a dolichofacial morphologic pattern. During this period, MB altered the face growth direction and decreased their mandible plane inclination, with reduction in the SN.GoGn, PP.MP, SNGn, and ArGo.GoMe parameters as well as an increase in BaN.PtGn. Conclusion. After the MB rehabilitation, children between 3 and 6 years old presented significant normalization in the mandibular growth direction, a decrease in the mandible inclination, and an increase in the posterior facial height. Instead, they still persisted with a dolichofacial pattern when compared with nasal breathers.

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Background/aims To compare two intraocular irrigating solutions, Balanced Salt Solution Plus (BSS Plus) versus Lactated Ringer`s (Ringer), for the preservation of corneal integrity after phacoemulsification. Methods 110 patients undergoing phacoemulsification were randomised to either BSS Plus (n = 55) or Ringer (n = 55) as the irrigating solution. Patients were examined at baseline and at 1, 8, 15, 30 and 60 days postoperatively. Evaluations included specular microscopy to evaluate endothelial cell density (ECD) and endothelial cell size variability (CV), and corneal pachymetry for central corneal thickness (CCT) measurement. Results Groups were well balanced regarding baseline ECD, CV and CCT (p>0.05). There was no statistically significant difference between ECD reduction in group BSS Plus 13.1 +/- 2.0% and Ringer 9.2 +/- 1.9% (p<0.05) at day 60 or in any study visit. There was no statistically significant difference between CV increase in group BSS Plus 23.0 +/- 3.0% and Ringer 20.2 +/- 4.0% (p<0.05) at day 60 or in any study visit. CCT was significantly increased (p<0.05) at 1, 8, 15 and 30 days postoperatively, returning to baseline at 60 days in both groups. There was no significant difference in CCT increase in both groups at any visit. Interestingly, there were statistically significant correlations between ECD loss and phacoemulsification time (p<0.0001) and ECD loss and irrigation solution volume (p<0.0001) in the Ringer group, but not in the BSS Plus group. Conclusions Ringers solution was similar to BSS Plus for corneal preservation in atraumatic cataract surgery. However, our study demonstrates that there is a trend towards lower postoperative endothelial cell density for surgeries with longer phacoemulsification time and higher irrigation volumes if Ringer is used.

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The aim of this study is to evaluate whether aspirin reduces Diabetis Mellitus (DM) oxidative damage in the lacrimal gland (LG), and ocular surface (OS). Ten weeks after streptozotocin induced DM and aspirin treatment, LG and OS of rats were compared for tear secretion, hidtology, peroxidase activity, and expression of uncoupling proteins (UCPs). DM reduction of tear secretion was prevented by aspirin (P < 0.01). Alterations of LG morphology and increased numbers of lipofucsin-like inclusions were observed in diabetic but not in aspirin-treated diabetic rats. Peroxidase activity levels were higher and UCP-2 was reduced in DM LG but not in aspirin treated (P = 0.0025 and P < 0.05, respectively). The findings prevented by aspirin indicate a direct inhibitory effect on oxidative pathways in LG and their inflammatory consequences, preserving the LG structure and function against hyperglycemia and/or insulin deficiency damage.

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Purpose To determine the relationship between ocular hypertension and glaucoma in patients with Graves` orbitopathy. Methods A total of 107 patients with a diagnosis of Graves` orbitopathy, followed at the Oculoplasty sector of the University Hospital, Medical School of Ribeirao Preto, were evaluated by applanation tonometry, computed visual campimetry (Humphrey 30-2, Full Threshold) and analysis and photographic documentation of the optic nerve. The patients considered to have the suspicion of glaucoma were re-evaluated 1 year later for diagnostic confirmation or exclusion. Results A 3.74% prevalence of ocular hypertension (four patients) and a 2.8% prevalence of glaucoma (three patients) was observed. When considering only patients older than 40 years, the prevalence of ocular hypertension was 5.4% (four patients) and the prevalence of glaucoma was 4.76% (three patients). Conclusion The present study did not reveal a statistically significant difference in the prevalence of ocular hypertension or glaucoma between patients with Graves` orbitopathy and the general population.

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The afferent nerves of the cornea and conjunctiva, efferent nerves of the lacrimal gland, and the lacrimal gland are a functional unit that works cooperatively to produce the aqueous component of tears. A decrease in the lacrimal gland secretory function can lead to dry eye disease. Because aging is a risk factor for dry eye disease, study of the changes in the function of the lacrimal gland functional unit with age is important for developing treatments to prevent dry eye disease. No one mechanism is known to induce the changes that occur with aging, although multiple different mechanisms have been associated with aging. These fall into two theoretical categories: programmed theories of aging (immunological, genetic, apoptotic, and neuroendocrine) and error theories of aging (protein alteration, somatic mutation, etc). Lacrimal glands undergo structural and functional alteration with increasing age. In mouse models of aging, it has been shown that neural stimulation of protein secretion is an early target of aging, accompanied by an increase in mast cells and lipofuscin accumulation. Hyperglycemia and increased lymphocytic infiltration can contribute to this loss of function at older ages. These findings suggest that an increase in oxidative stress may play a role in the loss of lacrimal gland function with age. For the afferent and efferent neural components of the lacrimal gland functional unit, immune or inflammatory mediated decrease in nerve function could contribute to loss of lacrimal gland secretion with age. More research in this area is critically needed.

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Purpose: To describe periorbital changes induced by chronic topical therapy with daily bimatoprost 0.03% (Lumigan, Allergan Inc., Irvine, CA, U.S.A.). Methods: A clinical investigation of 5 nonconsecutive patients with unilateral glaucoma treated daily with topical bimatoprost 0.03% for up to 4 years prior to presentation. Results: In eyes treated with bimatoprost 0.03% the authors noted periorbital fat atrophy, deepening of the upper eyelid sulcus, relative enophthalmos, loss of the lower eyelid fullness, and involution of dermatochalasis compared with the fellow untreated eye. By inspecting old photographs the authors confirmed that these unilateral changes were not present prior to starting bimatoprost. In addition, these changes were partially reversible after discontinuation of the medication, whenever that was possible. In 2 cases imaging studies confirmed the clinical impression that these findings were not related to primary orbital pathology. Conclusions: Physicians and patients should be aware of the potential of bimatoprost 0.03% to produce periorbital changes.

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Objective: This study aimed to assess the relative validity of a food frequency questionnaire.(FFQ), previously validated to measure usual intakes in adults, for measuring dietary intakes in children 5 to 10 y of age. Methods: Dietary intakes were measured using an FFQ and a 3-d dietary record. Healthy children, 5 to 10 y old (n = 151), were recruited from public schools and asked to answer the questions in the FFQ and to provide non-consecutive 3-d dietary records based on reported estimated portion sizes. Paired sample t tests and Pearson`s correlation coefficients were conducted to determine whether the two instruments reported similar values for energy and nutrients. The agreement of quartile categorization between the two instruments was also examined. Results: Estimated energy and nutrient intakes derived from the FFQ were significantly higher than those derived from 3-d dietary records. As expected, Pearson`s correlations increased after adjusting for residual measurement error, presumably due to exclusion of the high within-person variability in intake of these nutrients. Moderate to high (r > 0.50) correlation coefficients were verified for some nutrients such as calcium, folate, vitamin 132, vitamin A, and vitamin C. Conclusion: This FFQ, originally developed for use in adults, appears to overestimate usual energy and nutrient intakes in children 5 to 10 y of age. Further work is necessary to conduct a calibration study to establish adequate portion sizes before instrument adoption in this population. (c) 2008 Elsevier Inc. All rights reserved.

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The aim of this paper was to verify whether AC biosusceptometry (ACB) is suitable for monitoring gastrointestinal (GI) contraction directly from smooth muscle in dogs, comparing with electrical recordings simultaneously. All experiments were performed in dogs with magnetic markers implanted under the serosa of the right colon and distal stomach, and their movements were recorded by ACB. Monopolar electrodes were implanted close to the magnetic markers and their electric potentials were recorded by electromyography (EMG). The effects of neostigmine, hyoscine butylbromide and meal on gastric and colonic parameters were studied. The ACB signal from the distal stomach was very similar to EMG; in the colonic recordings, however, within the same low-frequency band, ACB and EMG signals were characterized by simultaneity or a widely changeable frequency profile with time. ACB recordings were capable of demonstrating the changes in gastric and colonic motility determined by pharmacological interventions as well as by feeding. Our results reinforce the importance of evaluating the mechanical and electrical components of motility and show a temporal association between them. ACB and EMG arecomplementary for studying motility, with special emphasis on the colon. ACB offers an accurate method for monitoring in vivo GI motility.

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Methionine-choline-deficient diet represents a model for the study of the pathogenesis of steatohepatitis. Male rats were divided into three groups, the first group receiving a control diet and the other two groups receiving a methionine-choline-deficient diet for 1 month (MCD1) and for 2 months (MCD2), respectively. The livers of the animals were collected for the determination of vitamin E, thiobarbituric acid reactive substances (TBARS), GSH concentration, DNA damages, and for histopathological evaluation. The hepatic TBARS and GSH content was higher (P < 0.05) in the groups receiving the experimental diet (MCD1 and MCD2) compared to control diet, and hepatic vitamin E concentration differed (P < 0.05) between the MCD1 and MCD2 groups, with the MCD2 group presenting a lower concentration. Damage to hepatocyte DNA was greater (P < 0.05) in the MCD2 group (262.80 DNA injuries/100 hepatocytes) compared to MCD1 (136.4 DNA injuries/100 hepatocytes) and control diet (115.83 DNA injuries/100 hepatocytes). Liver histopathological evaluation showed that steatosis, present in experimental groups was micro- and macro-vesicular and concentrated around the centrolobular vein, zone 3, with preservation of the portal space. The inflammatory infiltrate was predominantly periductal and the steatosis and inflammatory infiltrate was similar in the MCD1 and MCD2 groups, although the presence of Mallory bodies was greater in the MCD2 group. The study describes the contribution of a methionine-choline-deficient diet to the progression of steatosis, lipid peroxidation and hepatic DNA damage in rats, serving as a point of reflection about the role of these nutrients in the western diet and the elevated non-alcoholic steatohepatitis rates in humans.

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Adrenocortical tumors (ACT) are rare neoplasms of the adrenal glands accounting for 0.2% of all pediatric cancers. However, the incidence of ACT in South Brazilian children is 10 to 15 times greater than the worldwide incidence. Comparative genomic hybridization studies have revealed the presence of a high degree of chromosomal instability in ACT. We evaluated 16 ACT, 8 of them carcinomas and 8 adenomas. The presence of changes in DNA copy numbers was determined by comparative genomic hybridization, and the findings were validated by real-time polymerase chain reaction on the basis of IGF-II gene expression. The adenomas showed a mean of 19.7 imbalances per case, with the most frequent gain and loss being 4p15.1-p15.3 and 20p11.2-p13.2, respectively. The carcinomas presented with a mean of 35.5 imbalances per case, with the more frequent gain being 2q14.1-q24.3 and the more frequent losses being 3q21-q26.2, 20q12-qter, and 22q11.2-q13.3. The most frequent imbalances in both adenomas and carcinomas were gains of 1p21-p31.2, 2p12-p21 and loss of 20p11.2-p12. The expression of IGF-II mRNA (11p15.5) was higher in samples that presented with a gain of this region. It has been established that great genomic instability exists in pediatric ACT.

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Directed evolution techniques have been used to improve the thermal stability of the xylanase A from Bacillus subtilis (XylA). Two generations of random mutant libraries generated by error prone PCR coupled with a single generation of DNA shuffling produced a series of mutant proteins with increasing thermostability. The most Thermostable XylA variant from the third generation contained four mutations Q7H, G13R, S22P, and S179C that showed an increase in melting temperature of 20 degrees C. The thermodynamic properties Of a representative subset of nine XylA variants showing a range of thermostabilities were measured by thermal denaturation as monitored by the change in the far ultraviolet circular dichroism signal. Analysis of the data from these thermostable variants demonstrated a correlation between the decrease in the heat capacity change (Delta C(p)) with an increase in the midpoint of the transition temperature (T(m)) on transition from the native to the unfolded state. This result could not be interpreted within the context of the changes in accessible surface area of the protein on transition from the native to unfolded states. Since all the mutations are located at the surface of the protein, these results suggest that an explanation of the decrease in Delta C(p) on should include effects arising from the prot inlsolvent interface.