Biomedical subjects

Peter Woodruff

Publications and source records attributed to Peter Woodruff.

3 recordsLinked to original sources

PubMed2006

Evidence that brain tissue volumes are associated with HVA reactivity to metabolic stress in schizophrenia.

BACKGROUND: Although liability to psychosis is thought to have its origins in cerebral alterations, expressed as cerebral grey and white matter loss, less is known about the degree to which such vulnerabilities impact on functional parameters, in particular altered stress reactivity. Breier et al. [Breier, A., Davis, O.R., Buchanan, R.W., Moricle, L.A., Munson, R.C., 1993b. Effects of metabolic perturbation on plasma homovanillic acid in schizophrenia. Relationship to prefrontal cortex volume. Arch. Gen. Psychiatry 50(7), 541-550] reported that lower prefrontal cortex volume was associated with altered metabolic stress response, but this finding has never been replicated. METHODS: Thirty-one patients with psychosis underwent structural magnetic resonance imaging scanning and a metabolic stress paradigm (glucoprivic 2-deoxyglucose (2DG) condition versus placebo condition) that yielded information on plasma homovanillic acid (HVA) reactivity. Total cerebral tissue volumes were derived from automated segmentation procedures. Associations between metabolic stress and tissue volumes (as well as their interactions) on the one hand, and plasma HVA level on the other, were investigated using multilevel random regression techniques. RESULTS: Analysis revealed a significant increase in plasma HVA over time in the 2DG condition. The increase in HVA in the stress condition was stronger in patients with lower grey and white matter volumes. There was no significant interaction between metabolic stress and CSF volume. CONCLUSION: Lower grey and white matter volumes in schizophrenia are associated with a dysregulated dopaminergic/noradrenergic mediated stress response. These findings may support the hypothesis that alterations in cortico-subcortical connections affect psychosis susceptibility through an altered stress response.

Adolescent↗

PubMed2003

Searching for a structural endophenotype in psychosis using computational morphometry.

Structural cerebral abnormalities are frequently observed in schizophrenia. These abnormalities may indicate vulnerability for the disorder, as evidenced by reports of familial clustering of measures identified through region-of-interest analyses using manual outlining procedures. We used computational morphometry to detect structural differences within the entire brain to further examine possible structural endophenotypes. Magnetic resonance imaging scans were obtained in 31 psychotic patients, 32 non-psychotic first-degree relatives of psychotic patients and 27 healthy controls. The images were processed using an automated procedure, yielding global grey matter, white matter, CSF and total brain volume. The relative distribution of grey matter was compared between groups on a clustered-voxel basis. Global grey matter and total brain volume did not differ between the groups. White matter volume was significantly higher and CSF volume significantly lower in relatives compared to both cases and controls. The clustered-voxel based group comparison yielded evidence for significant grey matter deficits in fronto-thalamic-cerebellar regions, in psychotic patients, whereas the most prominent deficits in relatives involved the cerebellum. Patients with psychosis and first-degree healthy relatives of patients with psychosis show cerebellar abnormalities, which may constitute a marker of genetic transmission.

Adolescent↗

PubMed2002

Abdominal aortic aneurysm repair in the veteran population.

BACKGROUND: The aim of this study was to audit the outcome of elective open aortic aneurysm repair in a veteran hospital to determine whether age > or =80 years influenced the morbidity or mortality. METHODS: All elective abdominal aortic aneurysm (AAA) repaired at Greenslopes Private (Repatriation) Hospital between January 1995 and July 2000 were reviewed. Operative details, premorbid condition, postoperative outcomes as well as length of admission were recorded. Patients were grouped according to age as > or =80 years or <80 years. RESULTS: There were 251 open elective AAA (including infrarenal and suprarenal, as well as recurrent AAA) repairs carried out during this period, 64 of which were patients of age > or =80 years. Cardiovascular risks factors did not differ between groups nor did complication rates for patients > or =80 and <80 years of age (19.1 and 19.8%, respectively). Mortality rates were not significantly different between groups (> or =80 years: 6.25%; <80 years: 4.8%; P > 0.6). CONCLUSIONS: Age > or =80 years should not be an exclusion criteria when contemplating open elective AAA repair.

Aged↗