55 resultados para visual variables


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In this study, morphological changes in the optic nerve were determined by light microscopy in Wistar rats on an iron-deficient diet for 32 days or for 21 days followed by 10 days on an iron-recovery diet. The morphometric findings showed significantly fewer blood vessels and oligodendrocytes in the iron-deficient rats and iron-recovery rats than in the control group, as well as more astrocytes in the iron-recovery rats. Serum iron levels of the iron-deficient rats were significantly lower than those of the controls. On the other hand, iron-recovery rats had normal serum iron levels, but no change in the abnormal morphology of the myelinated axons and morphometric parameters. Our data indicate that iron is necessary for maintenance of the optic nerve cell structure, and morphological damage from iron-deficiency is not easily reverted by iron reposition.

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Background: Fat accumulation in the upper region of the body is common in polycystic ovary syndrome (PCOS) and is associated with metabolic complications. The present study aimed to assess the relationship between trunk circumference, metabolic indicators, and abdominal and visceral fat in obese PCOS women. Methods: The weight, fat mass, and subcutaneous arm fat (SAF) of 30 obese PCOS women and 15 healthy controls matched for age and body mass index were evaluated by bioelectrical impedance analysis. Trunk (TrC), neck (NC) and hip circumferences were measured, and the trunk/hip (Tr/H) ratio was determined. Total abdominal fat (TAF), visceral fat (VF) and trunk fat (TrF) were determined by computed tomography. Biochemical evaluation included glycaemia, insulinaemia, testosterone and lipid profile, insulin resistance (IR) was assessed by the QUICKI index. Results: In the PCOS group, there were positive correlations between NC and TAF (r = 0.49, P < 0.0006), TrC and VF (r = 0.62, P = 0.01), and NC and VF (r = 0.70, P < 0.0002). There was good correlation between TrC and TrF (r = 0.69, P = 0.003). TrF correlated with triglycerides levels positively (r = 0.44, P = 0.02). Women with PCOS and IR had a larger quantity of VF and TrF, but a smaller amount of SAF. Within the PCOS group, women with Tr/H ratio above the median had higher basal insulin levels and lower QUICKI indices compared to women presenting a Tr/H ratio below the median. Conclusions: TrC is associated with important metabolic variables in PCOS, proving to be a valuable and innovative tool for assessment of body adiposity distribution in obese PCOS women.

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Although the effects of cannabis on perception are well documented, little is known about their neural basis or how these may contribute to the formation of psychotic symptoms. We used functional magnetic resonance imaging (fMRI) to assess the effects of Delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) during visual and auditory processing in healthy volunteers. In total, 14 healthy volunteers were scanned on three occasions. Identical 10mg THC, 600mg CBD, and placebo capsules were allocated in a balanced double-blinded pseudo-randomized crossover design. Plasma levels of each substance, physiological parameters, and measures of psychopathology were taken at baseline and at regular intervals following ingestion of substances. Volunteers listened passively to words read and viewed a radial visual checkerboard in alternating blocks during fMRI scanning. Administration of THC was associated with increases in anxiety, intoxication, and positive psychotic symptoms, whereas CBD had no significant symptomatic effects. THC decreased activation relative to placebo in bilateral temporal cortices during auditory processing, and increased and decreased activation in different visual areas during visual processing. CBD was associated with activation in right temporal cortex during auditory processing, and when contrasted, THC and CBD had opposite effects in the right posterior superior temporal gyrus, the right-sided homolog to Wernicke`s area. Moreover, the attenuation of activation in this area (maximum 61, -15, -2) by THC during auditory processing was correlated with its acute effect on psychotic symptoms. Single doses of THC and CBD differently modulate brain function in areas that process auditory and visual stimuli and relate to induced psychotic symptoms. Neuropsychopharmacology (2011) 36, 1340-1348; doi:10.1038/npp.2011.17; published online 16 March 2011

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Aims: To determine the occurrence of isolated and recurrent episodes of conductive hearing loss (CHL) during the first two years of life in very low birth weight (VLBW) infants with and without bronchopulmonary dysplasia (BPD). Study design, subjects and outcome measures: In a longitudinal clinical study. 187 children were evaluated at 6, 9, 12,15 18 and 24 months of age by visual reinforcement audiometry, tympanometry and auditory brain response system. Results: Of the children with BPD, 54.5% presented with episodes of CHL, as opposed to 34.7% of the children without BPD. This difference was found to be statistically significant. The recurrent or persistent episodes were more frequent among children with BPD (25.7%) than among those without BPD (8.3%). The independent variables that contributed to this finding were small for gestational age and a 5 min Apgar score. Conclusions: Recurrent CHL episodes are more frequent among VLBW infants with BPD than among VLBW infants without BPD. (C) 2010 Elsevier Ireland Ltd. All rights reserved.

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PURPOSE: To evaluate the effects of intravitreal bevacizumab in patients with diabetic macular edema (DME) associated with severe capillary loss. DESIGN: Multicenter, open-label, nonrandomized study. METHODS: SETTING: Two tertiary ophthalmic referral centers in Brazil. STUDY POPULATION: Ten consecutive patients with DME and ""severe"" capillary loss. OBSERVATION PROCEDURES: Intravitreal injection(s) of bevacizumab (1.5 mg). Standardized ophthalmic evaluation was performed at baseline and at weeks 8, 16, 24, and 54. MAIN OUTCOME MEASURES: Changes in best-corrected visual acuity (BCVA) and in optical coherence tomography variables (central macular thickness [CMT] and total macular volume [TMV]). RESULTS: Significant changes in BCVA and in CMT/TMV were noted throughout the study (P<.001, P=.009, and P<.001, respectively). The mean logarithm of the minimal angle of resolution Early Treatment Diabetic Retinopathy Study BCVA was 0.786 (similar to 20/125(+1)) at baseline, 0.646 (similar to 20/80(-2)) at week 8, 0.580 (20/80(+1)) at week 16, 0.574 (similar to 20/80(+1)) at week 24, and 0.558 (similar to 20/80(+2)) at week 54. Compared with baseline, a significant change in BCVA was noted at all follow-up visits (P <=.008). The mean CMT/TMV values were, respectively, 472.6/10.9 at baseline, 371.4/9.9 at week 8, 359.5/9.8 at week 16, 323.9/9-4 at week 24, and 274.6/8.7 at week 54. Compared with baseline, a significant change in both CMT and TMV was noted only at 24 and 54 weeks (P <=.007). At 54 weeks, fluorescein angiography demonstrated no change in the extent of macular capillary loss and reduced dye leakage as compared with baseline in all patients. CONCLUSIONS: Favorable changes in BCVA and in CMT/TMV observed throughout 1 year suggest that intra-vitreal bevacizumab may be a viable alternative treatment for the management of patients with DME and severe capillary loss. (Am J Ophthalmol 2009;147:1022-1030. (C) 2009 by Elsevier Inc. All rights reserved.)

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Previous work has suggested that decrement in both processing speed and working memory span plays a role in the memory impairment observed in patients with schizophrenia. We undertook a study to examine simultaneously the effect of these two factors. A sample of 49 patients with schizophrenia and 43 healthy controls underwent a battery of verbal and visual memory tasks. Superficial and deep encoding memory measures were tallied. We conducted regression analyses on the various memory measures, using processing speed and working memory span as independent variables. In the patient group, processing speed was a significant predictor of superficial and deep memory measures in verbal and visual memory. Working memory span was an additional significant predictor of the deep memory measures only. Regression analyses involving all participants revealed that the effect of diagnosis on all the deep encoding memory measures was reduced to non-significance when processing speed was entered in the regression. Decreased processing speed is involved in verbal and visual memory deficit in patients, whether the task require superficial or deep encoding. Working memory is involved only insofar as the task requires a certain amount of effort. (JINS, 2011, 17, 485-493)

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Objective To evaluate the post-operative analgesic effect of metamizol (dipyrone) administered intravenously at three different doses (15 mg kg(-1), 25 mg kg(-1) and 35 mg kg(-1)) compared to placebo in dogs undergoing ovariohysterectomy. Study design Prospective, comparative, randomized. blinded trial. Animals Forty healthy bitches, aged 1-6 years, weighing 10-35 kg Methods The animals were randomly divided into four groups and received their respective treatments immediately after surgery: placebo group (0.9% saline solution), D15 group (metamizol 15 mg kg(-1) IV), D25 group (metamizol 25 mg kg(-1) IV), D35 group (metamizol 35 mg kg(-1) IV). The following variables were measured: sedation, pulse rate (PR). respiratory rate (f(R)). arterial blood pressure (ABP), plasma catecholamines. serum cortisol, blood urea nitrogen (BUN) and creatinine metabolites. albumin, alanine aminotransferase (ALT), alkaline phosphatase (ALP). hemogram. platelet counts and level of analgesia which was assessed by visual analog (VAS). descriptive and behavioral scales. Patients were monitored for 48 hours after the administration of the analgesic agent. Rescue analgesia (tramadol, 2 mg kg(-1), intramuscularly) was provided for animals with pain scores >= 4, as determined by the VAS or descriptive scale. Results The D25 and D35 groups showed equivalent post-operative analgesia, as shown by decreased pain scores, according to the three different pain scales, and fewer animals that required rescue analgesia. Significantly lower serum cortisol concentrations were observed in the D25 and D35 groups when compared to the placebo and D15 groups. No hematologic, renal, hepatic or clinical adverse effects were observed during the treatment. Conclusions and clinical relevance Metamizol administered intravenously at 25 or 35 mg kg(-1) can provide adequate post-operative analgesia in bitches undergoing ovariohysterectomy.

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The aim of the present study was to determine the relationship among body weight (BW), body condition score (BCS) and rump fat thickness (RFAT) measured by ultrasonography, and validate the relationship between BCS and RFAT over the time. Two hundred sixty and six Nelore cows had their BW, BCS and RFAT evaluated at five different moments during the production cycle: M1) weaning: M2) parturition, M3) 42 days post-partum; M4) 82 days postpartum and M5) 112 days post-partum. A BCS value was attributed for each cow following a I to 5 points scale. Ultrasonographic images for RFAT measurement were obtained using a 3.5 MHz linear transducer. Images were immediately analyzed as soon as they were formed and frozen. Body condition scores and ultrasound measurements were collected on the same day by a single trained technician. The relationship between BCS and RFAT values was investigated by regression models. The analysis of similarity among the five obtained models was performed using the proc MIXED from SAS and the correlations among variables were analyzed with proc CORR from SAS. The BCS was able to predict RFAT in Nelore cows in all different moments evaluated. Also, it was shown that BCS presented high correlation (r=0.82 to 0.93) and relationship (R(2) = 0.73 to 0.92) with RFAT. However, both BCS and RFAT showed low correlation (r=0.37 to 0.50) and relationship (R(2) = 0.13 to 0.25) with BW. The BCS classification by visual method using a 1 to 5 point scale, was able to predict the RFAT in Nelore cows over the time. (C) 2008 Elsevier B.V. All rights reserved.

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Objectives: The diagnosis of caries lesions is still a matter of concern in dentistry. The diagnosis of dental caries by digital radiography has a number of advantages over conventional radiography; however, this method has not been explored fully in the field of paediatric dentistry. This in vitro research evaluated the accuracy of direct digital radiography compared with visual inspection and conventional radiography in the diagnosis of occlusal caries lesions in primary molars. Methods: 50 molars were selected and evaluated under standardized conditions by 2 previously calibrated examiners according to 3 diagnostic methods (visual inspection, conventional radiography and direct digital radiography). Direct digital radiographs were obtained with the Dixi3 system (Planmeca, Helsinki, Finland) and the conventional radiographs with InSight film (Kodak Eastman Co., Rochester, NY). The images were scored and a reference standard was obtained histologically. The interexaminer reliability was calculated using Cohen`s kappa test and the specificity, sensitivity and accuracy of the methods were calculated. Results: Examiner reliability was good. For lesions limited to the enamel, visual inspection showed significantly higher sensitivity and accuracy than both radiographic methods, but no significant difference was found in specificity. For teeth with dentinal caries, no significant differences were found for any parameter when comparing visual and radiographic evaluation. Conclusions: Although less accurate than the visual method for detecting caries lesions confined to the enamel, the direct digital radiographic method is as effective as conventional radiographic examination and visual inspection of primary teeth with occlusal caries when the dentine is involved. Dentomaxillofacial Radiology (2010) 39, 362-367. doi: 10.1259/dmfr/22865872

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Purpose: To compare visual inspection (VI), radiographic examination (RX) and the laser fluorescence device DIAGNOdent (L), as well as their combinations in vitro regarding treatment decisions for occlusal surfaces. Methods: 72 extracted human permanent teeth (molars and premolars) were used. Treatment decisions were recorded by three calibrated examiners, and the options available were fissure sealant and conservative restoration. For validation of treatment decisions, the teeth were sectioned and examined in a stereomicroscope. Thereafter, dental slices were scanned and the images were edited to facilitate classification of existing carious lesions. Intra and inter-examiner reproducibility for the determination of treatment plans were calculated using Cohen`s kappa test (95%-CI). Sensitivity, specificity, positive and negative predictive values, and the area under the ROC curve were also calculated. Results: VI and L provided on average the greatest intra- and inter-examiner reproducibility, respectively. Although the combination of diagnostic methods may decrease both intra- and inter examiners reproducibility, combination of VI, L and RX resulted in the greatest sensitivity, being statistically superior to RX and L. There was more inter-examiner agreement for the option of restorative treatment, while the use of sealants as a treatment option yielded the lowest values. Negative predictive values were numerically inferior to positive predictive values, indicating that the examiners preferred not to restore a carious tooth than to proceed operatively in an intact tooth. The combination of the three methods studied showed the best results in determining treatment plans for occlusal surfaces, when compared to the other types of exams. On the other hand, radiographic examination and laser fluorescence were less efficient when used alone.