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A Ryman

Publications and source records attributed to A Ryman.

11 recordsLinked to original sources
PubMed1998

A voxel-based analysis of cerebral perfusion in dementia and depression of old age.

Thirty-nine elderly depressed patients as well as 15 demented patients with Alzheimer's disease and 11 healthy volunteers were imaged at rest with a high resolution single-slice 12-detector head scanner (SME-Neuro 900) and the cerebral perfusion marker 99mTc-Exametazime (HM-PAO). Statistical parametric maps were computed to compare early- and late-onset depressed, Alzheimer patients and healthy volunteers and to examine associations between regional perfusion and clinical and MRI variables. Patients with late-onset depression showed reductions in temporal lobe perfusion compared with early-onset depression and controls. Alzheimer patients had the expected reduced perfusion in temporoparietal and prefontal cortex, as well as basal ganglia, compared with healthy controls. Compared with depressed patients, they showed a relative reduction in temporoparietal cortex, only. This difference was more pronounced between Alzheimer patients and early onset, compared to late-onset patients with depression. Periventricular white matter changes on MRI were associated with temporal lobe reductions of tracer uptake in depression. In the Alzheimer group, deep white matter MRI changes were associated with frontal perfusion deficits. Our results support a vulnerability hypothesis, which predicts that patients with late-onset depression will show more brain changes than patients with an early onset of their illness. Statistical parametric mapping in patients with organic psychiatric brain syndromes is feasible and promising as a clinical and research method.

Aged↗
PubMed1998

Autoantibodies directed against phospholipids or human beta 2-glycoprotein I in HIV-seropositive patients: relationship with endothelial activation and antimalonic dialdehyde antibodies.

BACKGROUND: We investigated the possible role of antiphospholipid (APA) and anti-human 2-glycoprotein I (beta2-GPI) antibodies (Ab) in thrombosis and atherosclerosis in human immunodeficiency (HIV)-positive patients, in whom they seem to be more frequent. METHODS: We measured APA and anti-beta2-GPI Ab in 58 HIV-positive patients together with markers of disease progression, circulating beta2-GPI, plasma lipids, biological markers of endothelial activation and integrity (plasma thrombomodulin, von Willebrand factor, vascular cell adhesion molecule 1) and with antimalonic dialdehyde antibodies (anti-MDA Ab). RESULTS: We found a 41% frequency of IgG APA in the HIV-positive patients. APA IgMs were rarely positive (7%), and anti-beta2-GPI IgGs were positive in 3-4% patients. There was no correlation between APA or anti-beta2-GPI Ab and the presence of opportunistic infections. Although plasma thrombomodulin, von Willebrand factor and vascular cell adhesion molecule 1 were significantly increased in the HIV-positive patients, APA was correlated only with vascular cell adhesion molecule 1, suggesting that APAs are correlated with endothelial activation but not with vascular endothelial lesions. A correlation between APA and anti-MDA IgG was demonstrated using multivariate analysis (r=0.542, P < 0.0001), suggesting a relationship between the targets of these antibodies. Finally, IgG APAs are frequent in HIV infection but are not correlated with biological markers of endothelial injury. CONCLUSION: Our results do not support a role for APA or anti-beta2-GPI in HIV-associated silent vascular endothelial damage. However, the role of these autoantibodies in clinically relevant thrombotic events should be investigated in HIV-positive patients.

Adult↗
PubMed1997

Performance on the delayed word recall test (DWR) fails to differentiate clearly between depression and Alzheimer's disease in the elderly.

BACKGROUND: The differential diagnosis of early dementia of the Alzheimer's type from depression in the elderly is often made difficult by the presence of significant memory impairment in depressed patients. The Delayed Word Recall test (DWR) was developed to facilitate the early diagnosis of Alzheimer's disease. The DWR involves: (a) repeated elaborate encoding of ten separate words; (b) a filled delay; (c) delayed free recall. A recognition memory test has also been recently developed. The available evidence suggests impressive sensitivity and specificity when the DWR has been used to separate patients with early Alzheimer's disease from very well matched controls. METHODS: In the present study, the DWR was evaluated with regard to its ability to separate a group of 50 patients with early Alzheimer's disease from 50 elderly patients with major depression in a between-subjects experimental design. RESULTS: For both free recall and recognition indices, the between-group overlap was large. Using recommended cut-off scores for the detection of Alzheimer's disease, 44% of the depressed patients would have been misclassified as demented based on their free recall scores, and 48% of the depressed patients would have been misclassified on the basis of their recognition scores. CONCLUSION: We conclude that the DWR is not specific enough to clearly distinguish patients with early Alzheimer's disease from elderly patients with major depression.

Aged↗
PubMed1997

Temporal lobe abnormalities in dementia and depression: a study using high resolution single photon emission tomography and magnetic resonance imaging.

OBJECTIVES: Perfusion SPECT and MRI were used to test the hypothesis that late onset depression is associated with brain abnormalities. METHODS: Forty depressed patients (DSM-III-R major depressive episode, not demented at two year follow up) were recruited who were either drug free, or on a stable dose of antidepressants for at least three weeks, as well as 22 demented patients (DSM-IIIR and NINCDS/ADRDA criteria for probable Alzheimer's disease). Patients were imaged at rest with a high resolution single slice 12 detector head scanner (SME-Neuro 900) and the cerebral perfusion marker 99mTc-exametazime (HM-PAO). Temporal lobe templates were fitted with brains pitched by 20 degrees-30 degrees. A subgroup of 41 patients (22 depressed) were also scanned using a Siemens Magnetron 1.0 Tesla magnetic resonance imager, using a FLAIR imaging sequence for the assessment of white matter hyperintensities, and a Turbo FLASH sequence for the measurement of medial temporal lobe width. RESULTS: Demented patients showed reduced perfusion, particularly in the left temporoparietal cortex. In these regions of interest, patients with late onset depression tended to have perfusion values intermediate between patients with early onset depression and demented patients. Differences in changes in white matter between demented and early and late onset depressive patients did not reach conventional levels of significance. Temporal lobe width differed between demented and depressed patients, but not between early and late onset depressed patients. Perfusion and temporal lobe width were not associated, but reductions of perfusion were associated with periventricular white matter changes. Mini mental state examination scores were associated with temporal perfusion in demented patients and with changes in deep white matter in depressed patients. Finally, severity of depressive symptoms was associated with decreased perfusion in frontotemporal and basal ganglia regions of interest. CONCLUSION: A cumulative effect of duration of illness on regional cerebral perfusion could not be confirmed. Late onset depression may show more abnormalities of deep white matter and of left temporoparietal perfusion than early onset depression, but the underlying pathology remains to be established.

Aged↗
PubMed1994

Randomised controlled trial in northern England of the effect of a person knowing their own serum cholesterol concentration.

SUBJECT OBJECTIVE: To test the hypotheses that the knowledge that the serum cholesterol concentration is raised (> or = 6.5 mmol/l) will lead to a reduction in the concentration after education intervention and that the knowledge that the concentration is not raised does not lead to an increase in the serum cholesterol concentration after education intervention. DESIGN: Prospective randomised trial, with investigators blind to the randomisation. SETTING: An industrial site in Manchester, England. PARTICIPANTS: A total of 495 employees of Imperial Chemical Industries, 469 of whom completed the trial. MAIN RESULT: There was a significant reduction in the serum cholesterol concentration of those whose initial concentration was > or = 6.5 mmol/l and who were given the result. This reduction was 0.28 mmol/l greater than in the control group. The reduction was similar, however, to the increase in the serum cholesterol concentration in those whose initial concentration was < 5.2 mmol/l, regardless of whether or not they had been given the result. CONCLUSION: These results support the hypotheses, although the lack of regression to the mean in the control group with high serum cholesterol suggests that this conclusion should be treated with caution.

Adult↗
PubMed1990

Electrophysiological properties of nigrothalamic neurons after 6-hydroxydopamine lesions in the rat.

Extracellular recordings were made from electrophysiologically identified nigrothalamic cells in the substantia nigra pars reticulata of anaesthetized rats. The firing rate, firing pattern and responses to striatal stimulation were investigated in normal animals and in animals in which dopamine concentration in the ipsilateral striatum was reduced by more than 90%. At relatively short times after the lesion (less than 10 days) the mean firing rate of the spontaneously active cells in the population was significantly reduced and there was an increase in the occurrence of bursting activity. There was also a significant increase in the number of silent cells, located by antidromic stimulation from the thalamus. In spite of this reduction in mean firing rate the responses of neurons to stimulation of either the ipsilateral striatum or ventromedial thalamus was much larger in cells from lesioned animals. At longer times after the lesion (more than six months) the average firing rate of the neurons had returned to normal but there was still a prevalence of bursting activity and a consequent reduction in mean inter-spike intervals. There was little evidence of the previous hyper-responsiveness to thalamic stimulation but the responsiveness to striatal stimulation was still significantly elevated.

Animals↗