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Biomedical subjects

A A O'Brien

Publications and source records attributed to A A O'Brien.

At least 19 recordsLinked to original sources
PubMed1999

Blood pressure lowering for the primary and secondary prevention of stroke: treatment of hypertension reduces the risk of stroke.

Hypertension is the most important risk factor in the development of stroke. It is also the risk factor most amenable to treatment. The results from 18 controlled trials show a reduction in relative risk of stroke of 25-47% among treated hypertensive patients. This reduction applies both to the elderly and to younger patients, but the absolute reductions are greater among the elderly and the number of patients with hypertension that need to be treated to prevent a stroke is lower in the elderly because they have a higher risk of stroke. The reductions in relative but not absolute risk appear to be similar for both isolated systolic hypertension and combined systolic and diastolic hypertension in the elderly. The case for antihypertensive treatment in the secondary prevention of stroke is less clear but the results of four clinical trials of antihypertensive treatment among patients with and without hypertension and a history of cerebrovascular disease point to a probable benefit. The results of the PROGRESS trial will elucidate this further.

Antihypertensive Agents↗
PubMed1998

Scintigraphy with 123I-serum amyloid P component in Alzheimer disease.

The neuropathology of Alzheimer disease (AD) includes cerebral and cerebrovascular amyloid deposits composed of A(beta) protein. Extracerebral deposits of A(beta), identified immunohistochemically, have also been reported but without evidence for the presence of amyloid fibrils. Serum amyloid P component (SAP) is a normal plasma glycoprotein that binds to the fibrils in all types of amyloid deposit, and radiolabeled SAP is a specific, sensitive, quantitative diagnostic tracer for systemic amyloid deposits in vivo. However, we report that in 11 patients with probable or definite AD, conventional whole body planar scintigraphy after injection of 123-SAP revealed no detectable localization of tracer within the brain or elsewhere. Significant amounts of systemic extracerebral A(beta) amyloid are thus probably not a feature of AD. Also, although plasma-derived SAP is always present in the cerebral and cerebrovascular amyloid lesions of AD, there was insufficient accumulation of injected labeled SAP to be detected by the present routine methodology.

Aged↗
PubMed1991

Small-cell lung cancer in elderly patients: the case for chemotherapy.

We present a retrospective analysis of survival in 48 elderly (older than 65 years) and 70 young patients with small-cell lung cancer. Thirty-four elderly and 62 young patients had combination chemotherapy. Overall probability of survival with combination chemotherapy was similar for old and young patients (chi 2 = 0.79, d.f. = 1, p = 0.374). Peripheral neuropathy secondary to vincristine was more common with elderly patients. We believe that decisions about chemotherapy in elderly patients with small-cell lung cancer should be based on performance status, extent of disease and clinical condition rather than age.

Adult↗
PubMed1990

The effect of peritoneal dialysate on pulmonary function and blood gasses in C.A.P.D. patients.

There have been many reports showing diminished vital capacity (VC), total lung capacity (TLC), and functional residual capacity (FRC), after the infusion of peritoneal dialysate in patients on continuous ambulatory peritoneal dialysis (C.A.P.D.) for chronic renal failure. We also examined the effects of the infusion of two litres of dialysate on airways resistance (Raw) using total body plethysmography and on arterial blood gasses. Ten patients on C.A.P.D. were selected. The mean results of dialysate infused (in) and dialysate drained (out) are as follows: FVC 3.66 l (in) and 3.73 l (out) (not significant); VC 3.81 l (in) and 3.99 l (out) (p less than 0.05); FEV1 3.02 l (in) and 2.94 (out) (n.s.); TLC 5.89 l (in) and 6.33 l (out) (p less than 0.05); FRC 3.56 l (in) and 3.78 l (out) (p less than 0.05); Raw 4.79 cmsH21/l/s (in) and 4.72 cmsH20/l/s (out) (n.s.); Pa02 11.03 kPA (in) and 11.35 kPA (out) (p less than 0.001). We conclude that two litre dialysate causes significant reduction of TLC, VC and FRC, and a reduction in Pa02 and A-a02 but has no effect on airways resistance.

Airway Resistance↗
PubMed1990

Acute epidemic aluminium osteomalacia secondary to water supply contamination.

When the aluminium content of the water supply to our Haemodialysis Unit rose from less than 0.5 mumol/l to 6 mumol/l over a two month period, we carried out bone biopsies and desferrioxamine infusion tests on twelve (12) patients who had been on haemodialysis for less than one year (mean 8 months) and had normal serum aluminium levels. The patients had no bone symptoms. Eight patients had positive aluminium bone stains. The aluminium osteomalacia group (n = 8) had a mean PTH of 1.4 ng/ml s.e. 0.3 whereas the non-ALO group had a mean PTH of 2.9 ng/ml s.e. 0.7. The difference in mean PTH is significant (p less than 0.05). There was no evidence of encephalopathy, fractures or microcytic anaemia in the ALO positive group. The aluminium contamination of the water supply occurred because of a change in the reservoir purification system from sand-filtration to alum.

Adolescent↗
PubMed1990

Aluminium osteomalacia in chronic renal failure patients neither on dialysis nor taking aluminium containing phosphate binders.

The incidence of aluminium osteomalacia (ALO) in patients with chronic renal failure neither on dialysis nor taking aluminium-containing phosphate binders (ACPB) is not well documented. Biochemical and histological bone investigations were performed in 35 patients fulfilling the above conditions, among whom we found an incidence of ALO of 17%. In the ALO group, salient findings were PTH level (mean +/- s.d.) of 3.1 +/- 1.4 ng/ml (normal less than 0.5 ng/ml); elevated home tap-water aluminium levels of 6.5 +/- 1.2 umol/l (normal less than 2 umol/l); and a GFR of 20.5 mls/min/1.73m, (range 2-50 mls/min/1.73m). We conclude that the aetiology of ALO in this group involves the absorption of toxic home water aluminium in the presence of an elevated PTH level and a GFR less than 50 mls/min/1.73m.

Adult↗
PubMed1989

Multiple lymphomatous polyposis of the gastrointestinal tract. A clinicopathologically distinctive form of non-Hodgkin's lymphoma of B-cell centrocytic type.

Multiple lymphomatous polyposis of the gastrointestinal tract was initially described as mucosal lymphomatous involvement by any of a variety of Hodgkin's or non-Hodgkin's lymphomas that produced a polypoid appearance over long segments of the gastrointestinal tract. We studied four patients in whom histology revealed diffuse small cleaved cell lymphoma (one case), or intermediate lymphocytic lymphoma of diffuse type (one case), or mantle zone pattern (two cases). All four cases are classifiable as centrocytic lymphoma. Cell suspension and immunocytochemical studies demonstrated B-cells of IgMD or M type with light chain restriction (two kappa, two lambda) showing a B1+ HLA Dr+ LN2+ CD5+ CD10+. Although all four patients had a partial response to combination chemotherapy, three of them died within 3 years. Analysis of 24 cases reported since 1971 (including the present cases) suggests that MLP is a distinct clinicopathological entity that results from gastrointestinal involvement by a B-cell centrocytic lymphoma. It is distinct from the recently described clinicopathological forms of centrocytic lymphoma and intermediate lymphocytic lymphoma, which both show extensive peripheral lymphadenopathy and splenomegaly, but it is probably closely related to them. The differences are probably attributable to distinct cell tropism or homing properties rather than to cellular histogenesis or degree of maturation.

Aged↗
PubMed1987

The simultaneous presentation of peripheral T-cell lymphoma and hairy cell leukemia.

A patient who presented simultaneously with B hairy cell leukemia (HCL) and peripheral T-cell lymphoma (PTL) is described. The diagnoses of the two neoplasms were made by standard morphologic and cytochemical study and confirmed immunologically. There was no evidence of overlap in markers to suggest that they arose from a single clone of malignant cells. It is suggested that the simultaneous occurrence of the two neoplasms in the same patient reflects an underlying predisposition to the development of neoplasia in HCL.

Antibodies, Monoclonal↗
PubMed1987

Pulmonary berylliosis on corticosteroid therapy, with cavitating lung lesions and aspergillomata--report on a fatal case.

A fatal case of pulmonary berylliosis in a 42 year old male is described. The patient was exposed to beryllium while working in a chemical plant over a 9 year period, and presented two years after ceasing such employment. The berylliosis was diagnosed on open lung biopsy in 1971. The patient was commenced on steriod therapy at that time. He suffered progressive dyspnoea from severe restrictive lung disease over the next 14 years. A chest X-ray of June 1985 revealed a lesion in the left upper lobe suggestive of a mycetoma. Before any therapy could be instituted he suffered a massive haemoptysis and died. Post-mortem examination revealed two large mycetomata in the right and left upper lobes. Parenchymal histology showed evidence of chronic inflammation with non-caseating granulomata and the cavity wall showed localized invasion by Aspergillus fumigatus. It is possible that the long term steroid therapy with multiple boosters of treatment may have contributed to the development of the mycetoma. This is the first case report known to the authors of a fatal aspergilloma in association with chronic berylliosis treated with steroids.

Adult↗
PubMed1987

The use of intravenous and intraperitoneal desferrioxamine in aluminium osteomalacia.

A 32-year-old male with aluminium osteomalacia was changed from haemodialysis to chronic ambulatory peritoneal dialysis (CAPD) because of vascular access problems. Desferrioxamine (6 g) was administered intravenously on a once-weekly basis and the quantity of aluminium removed from each dialysate was calculated weekly. Aluminium concentration was estimated using the electrothermal atomic absorption spectrophotometer. The total aluminium removed after one week was 191 mumol, giving a clearance for aluminium of 4.2 ml per min. Subsequently intraperitoneal desferrioxamine 0.5 g per dialysate was administered to a total dose of 6 g and the cumulative aluminium loss was 134.1 mumol giving a clearance of 3.1 ml per min. The weekly loss of aluminium from dialysate when no desferrioxamine was administered was 58.3 mumol, giving a clearance of 2.5 ml per min. This is the first documented comparison of clearance rates for aluminium between CAPD alone, CAPD plus intravenous desferrioxamine and CAPD plus intraperitoneal desferrioxamine.

Adult↗