943 resultados para Stephen Gray
Resumo:
Objective: The purpose of this study was to investigate regional structural abnormalities in the brains of five patients with refractory obsessive-compulsive disorder (OCD) submitted to gamma ventral capsulotomy. Methods: We acquired morphometric magnetic resonance imaging (MRI) data before and after 1 year of radiosurgery using a 1.5-T MRI scanner. Images were spatially normalized and segmented using optimized voxel-based morphometry (VBM) methods. Voxelwise statistical comparisons between pre- and post-surgery MRI scans were performed using a general linear model. Findings in regions predicted a priori to show volumetric changes (orbitofrontal cortex, anterior cingulate gyrus, basal ganglia and thalamus) were reported as significant if surpassing a statistical threshold of p<0.001 (uncorrected for multiple comparisons). Results: We detected a significant regional postoperative increase in gray matter volume in the right inferior frontal gyri (Brodmann area 47, BA47) when comparing all patients pre and postoperatively. Conclusions: Our results support the current theory of frontal-striatal-thalamic-cortical (FSTC) circuitry involvement in OCD pathogenesis. Gamma ventral capsulotomy is associated with neurobiological changes in the inferior orbitofrontal cortex in refractory OCD patients. (C) 2008 Elsevier Ireland Ltd. All rights reserved.
Resumo:
Background/Aims: Hepatocellular carcinoma (HCC) is a well recognized complication of advanced NASH (non-alcoholic steatohepatitis). We sought to produce a rat model of NASH, cirrhosis and HCC. Methods: Adult Sprague-Dawley rats, weighing 250-300 g, were fed a choline-deficient, high trans-fat diet and exposed to DEN in drinking water. After 16 weeks, the animals underwent liver ultrasound (US), sacrifice and assessment by microscopy, immunohistochemistry and transmission electron microscopy (TEM). Results: US revealed steatosis and focal lesions in 6 of 7. All had steatohepatitis defined as inflammation, advanced fibrosis and ballooning with Mallory-Denk bodies (MDB) with frank cirrhosis in 6. Areas of more severe injury were associated with anti-CK19 positive ductular reaction. HCC, present in all, were macro-trabecullar or solid with polyhedral cells with foci of steatosis and ballooned cells. CK19 was positive in single or solid nests of oval cells and in neoplastic hepatocytes. TEM showed ballooning with small droplet fat, dilated endoplasmic reticulum and MDB in non-neoplastic hepatocytes and small droplet steatosis in some cancer cells. Conclusions: This model replicated many features of NASH including steatohepatitis with ballooning, fibrosis, cirrhosis and hepatocellular carcinoma. Oval cell proliferation was evident and the presence anti-CK 19 positivity in the cancer suggests oval cell origin of the malignancy. (C) 2008 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.
Resumo:
Objective: To compare the volume of the hippocampus and parahippocampal gyrus in elderly individuals with and without depressive disorders, and to determine whether the volumes of these regions correlate with scores on memory tests. Method: Clinical and demographic differences, as well as differences in regional gray matter volumes, were assessed in 48 elderly patients with depressive disorders and 31 control subjects. Brain (structural MRI) scans were processed using statistical parametric mapping and voxel-based morphometry. Cognitive tests were administered to subjects in both groups. Results: There were no between-group gray matter volume differences in the hippocampus or parahippocampal gyrus. In the elderly depressed group only, the volume of the left parahippocampal gyrus correlated with scores on the delayed naming portion of the visual verbal learning test. There were also significant direct correlations in depressed subjects between the volumes of the left hippocampus, right and left parahippocampal gyrus and immediate recall scores on verbal episodic memory tests and visual learning tests. In the control group, there were direct correlations only between overall cognitive performance (as assessed with the MMSE) and the volume of right hippocampus, and between the total score on the visual verbal learning test and the volume of the right and left parahippocampal gyrus. Conclusions: These findings highlight different patterns of relationship between cognitive performance and volumes of medial temporal structures in depressed individuals and healthy elderly subjects. The direct correlation between delayed visual verbal memory recall scores with left parahippocampal volumes specifically in elderly depressed individuals provides support to the view that depression in elderly populations may be a risk factor for dementia. (C) 2009 Elsevier Inc. All rights reserved.
Resumo:
Study Objectives: Sleep apnea is common in patients with congestive heart failure, and may contribute to the progression of underlying heart diseae. Cardiovascular and metabolic complications of sleep apnea have been attributed to intermittent hypoxia. Elevated free fatty acids (FFA) are also associated with the progression of metabolic, vascular, and cardiac dysfunction. The objective of this study was to determine the effect of intermittent hypoxia on FFA levels during sleep in patients with heart failure. Design and interventions: During sleep, frequent blood samples were examined for FFA in patients with stable heart (ejection fraction < 40%). In patients with severe sleep apnea (apnea-hypopnea index = 15.4 +/- 3.7 events/h; average low SpO(2) = 93.6%). In patients with severe sleep apnea, supplemental oxygen at 2-4 liters/min was administered on a subsequent night to eliminate hypoxemia. Measurements and Results: Prior to sleep onset, controls and patients with severe apnea exhibited a similar FFA level. After sleep onset, patients with severe sleep apnea exhibited a marked and rapid increase in FFA relative to control subjects. This increase persisted throughout NREM and REM sleep exceeding serum FFA levels in control subjects by 0.134 mmol/L (P = 0.0038) Supplemental oxygen normalized the FFA profile without affecting sleep architecture or respiratory arousal frequency. Conclusion: In patients with heart failure, severe sleep apnea causes surges in nocturnal FFA that may contribute to the accelerated progression of underlying heart disease. Supplemental oxygen prevents that FFA elevation.
Resumo:
Objectives The subgenual prefrontal cortex (SGPFC) is an important brain region involved in emotional regulation and reward mechanisms Volumetric abnormalities in this region have been identified in adults with bipolar disorder but thus far not in pediatric cases We examined the volume of this brain region in subjects with pediatric bipolar disorder (PBD) and compared them to healthy controls Methods Fifty one children and adolescents (mean age +/- SD 13 2 +/- 2 9 y) with DSM-IV PBD and 41 (mean age +/- SD 13 7 +/- 2 7 y) healthy comparison subjects (HC) underwent 1 5 T structural magnetic resonance imaging (MRI) brain scans We traced the SGPFC manually and compared SGPFC gray matter volumes using analysis of covariance with age gender and intracranial volume as covariates We also examined the relationship of family history of affective disorders and medication status to SGPFC volumes Results SGPFC volumes were not significantly different in PBD and HC subjects However exploratory analysis showed PBD subjects who had one or more first degree relatives with mood disorders (n = 33) had significantly smaller left hemisphere SGPFC compared to HC (p = 003 Sidak corrected) Current usage of a mood stabilizer was significantly associated with larger right SGPFC volume in PBD (F = 4 82 df = 1/41 p = 0 03) Conclusion Subjects with PBD and a close family history of mood disorders may have smaller left SGPFC volumes than HC Mood stabilizing medication may also impact SGPFC size and could have masked more subtle abnormalities overall (C) 2010 Elsevier Ltd All rights reserved
Resumo:
Suicidality is a life-threatening symptom in patients with bipolar disorder (BD). Impulsivity and mood instability are associated with suicidality in mood disorders. Evidence suggests that gray and white matter abnormalities are linked with impulsivity in mood disorders, but little is known about the association between corpus callosum (CC) and impulsivity in BID. We examined the relationship between CC areas, impulsivity and suicidality in BID patients. We studied 10 female BD patients with a history of suicide attempt (mean +/- SD age 36.2 +/- 10.1 years), 10 female BD patients without suicide attempt history (44.2 +/- 12.5 years) and 27 female healthy subjects (36.9 +/- 13.8 years). Impulsivity was evaluated by the Barratt Impulsivity Scale (BIS). We traced MR images to measure the areas of the CC genu, anterior body, posterior body, isthmus and splenium. The genu was divided into anterior, middle and posterior regions. The suicidal and non-suicidal BID patients had significantly higher BIS total, attention and non-planning scores than the healthy subjects (ps < 0.01), and the suicidal BID patients had significantly higher BIS motor scores than the non-suicidal BD and healthy subjects (ps < 0.01). There were no significant differences among the three groups on any regional CC areas, although the suicidal BD patients had the smallest areas. The suicidal BD patients showed a significant inverse correlation between anterior genu area and the BIS total (r = -0.75, p = 0.04), motor (r = -0.79, p = 0.02) and non-planning scores (r = -0.79, p = 0.02). These correlations were not found in the non-suicidal BID patients or healthy subjects. The results suggest that the anterior medial frontal region may be involved in the pathophysiology of impulsive and suicidal behaviors in BD. (C) 2009 Elsevier Ireland Ltd. All rights reserved.