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Biomedical subjects

S Sheehan

Publications and source records attributed to S Sheehan.

27 records · Page 2Linked to original sources
PubMed1990

Extracorporeal shockwave lithotripsy monotherapy for paediatric urinary tract calculi.

The role of extracorporeal shockwave lithotripsy (ESWL) in the management of paediatric urinary tract calculi was evaluated. The study group included 22 children (13 male, 9 female) with an age range of 2 to 13 years. The renal calculi, including staghorn and ureteric calculi, varied in size from 0.3 to 5 cm. Overall stone clearance at 3 months was 79% with a low incidence of complications (2 children required nephrostomy drainage for sepsis). ESWL is a non-invasive method of managing even complex stones in children of all ages, irrespective of size or position.

Adolescent↗
PubMed1989

Prognostic value of nucleolar organizer regions and ploidy values in advanced colorectal cancer.

The prognostic value of nucleolar organizer regions and ploidy status in patients with Dukes' C colorectal cancer was determined. In addition, nucleolar organizer regions and ploidy status were compared with the established prognostic indices age, sex, tumour location and degree of histological differentiation. Fifty-one patients (27 men, 24 women) aged 35-81 years (median 64.8 years) were studied. Five years after presentation, 16 patients were alive and well. Survivors had significantly lower nucleolar organizer region counts (median value and range) in primary tumours 12 (8-15) and lymph node metastases 11 (8-15) than non-survivors 17 (14-25) and 18 (13-25) respectively (P less than 0.05). Fewer survivors had aneuploid tumours than non-survivors: four survivors compared with 17 non-survivors. In a regression analysis model, nucleolar organizer regions were the most important individual variable for predicting survival (chi2 = 15, P less than 0.01) while ploidy values (chi2 = 6, P less than 0.2) were equivalent to histological differentiation.

Adult↗
PubMedDate not supplied

Iodine intake in pregnancy in Ireland--a cause for concern?

BACKGROUND: Adequate dietary iodine intake is necessary to maintain maternal thyroid function at a level permitting normal neuropsychological development of the foetus. AIMS AND METHODS: To determine dietary iodine status by measuring urinary iodine excretion (UIE), proportional to dietary intake, in Irish mothers during the first trimester of pregnancy. RESULTS: Median UIE showed seasonal variations, being lower in summer than in winter. The median values in pregnant women were, summer 45microg/l, winter 68microg/l. Equivalent values for controls were 43 and 91microg/l respectively. UIE required to achieve WHO recommended daily iodine intakes would be 120-180microg/l. In the Irish subjects UIE values suggestive of iodine deficiency (<50microg/l) were observed in 55% of pregnant women tested in summer and 23% in winter. Dairy milk iodine, a major dietary iodine source, showed similar variation. CONCLUSIONS: While there is as yet no available evidence of widespread thyroid hypofunction in the Irish obstetric population, the findings are a cause of concern, which if confirmed by a more comprehensive investigation, may indicate the need for iodine prophylaxis.

Adult↗
PubMedDate not supplied

Aorto-enteric fistula: changing management strategies.

BACKGROUND: Traditionally treatment of aorto-enteric fistulae involved placement of an extra-anatomic bypass and graft excision. This is associated with limb loss (10-40%) and high mortality (10-70%). More recently in situ revascularisation has been advocated. AIMS: To examine our experience with the changing management of aorto-enteric fistulae over a 22-year period. METHODS: Demographic, clinical, operative and pathological data were recorded retrospectively. RESULTS: Twenty-one patients were included. Seven had primary fistulae. Six died prior to intervention. Five had an extra-anatomical bypass (60% mortality, 40% limb loss), four had in-situ revascularisation (25% mortality), four had a primary repair (25% mortality) and two had insertion of a tube graft (primary fistulae). The overall survival rate was 38%. The postoperative survival rate was 6o%. CONCLUSION: Techniques for operative management continue to evolve. The current trend is towards a local surgical approach with prolonged and intensive postoperative antimicrobial therapy. In our experience this approach has yielded acceptable outcomes.

Aged↗
PubMedDate not supplied

Effects of hyperthermia on bone. I. Heating rate patterns induced by microwave irradiation in bone and muscle phantoms.

We describe the initial heating rate patterns generated by microwave irradiation of 915 MHz, with constant power output, in muscle-equivalent phantoms containing a freshly excised bone, and compared with those in phantoms consisting of muscle-equivalent gel only. At 1 cm depth the muscle was cooler in the centre of the field when bone was present underneath. Also, the orientation of the bone in the field had a pronounced effect on the heating rate profiles in the overlying muscle: when the long axis of the bone was parallel to E field, a hot area in the centre of the field was observed; after rotation of the applicator by 90 degrees so that the long axis of the bone was perpendicular to the E field, more homogeneous heating was obtained along most of the field. In contrast, the heating patterns obtained in the cortex of the bone at similar depth (1.3 cm) were not substantially influenced by its orientation in the field. Depending on field location, the heating rate of the cortical bone closest to the applicator was within 50-75% of the SAR in muscle at the same depth. We believe that these data may be useful for the extension of such measurements in vivo, to permit the effective application of hyperthermia, with or without radiation, in the treatment of bone lesions.

Bone Neoplasms↗
PubMedDate not supplied

Effects of hyperthermia on bone. II. Heating of bone in vivo and stimulation of bone growth.

Previous studies in vitro have shown that it is possible to achieve comparable temperature distribution in bone and the adjacent soft tissues, under appropriate experimental conditions. The objective of the present work was to determine the effects of hyperthermia on bone in vivo. In order to obtain direct temperature measurements in bone, catheters were surgically installed on top of and inside the medullary cavity of the femur of normal rabbits. The thighs were irradiated with 915 MHz microwaves for 45 min, once or twice a week. The temperatures on and inside the bone were maintained between 42.5 and 44.0 degrees C; the resulting temperatures in the muscle were within 1.0 degrees C at depths equidistant from the applicator. After four to six treatments the femora were excised for histopathological examination. New trabecular bone was deposited around the catheters; most bone components including periosteum, osteoid, and fully calcified matrix could be seen. Large numbers of osteoblasts and osteoclasts lined the trabecular surfaces, and numerous cement lines were visible, running in all directions, indicating extensive bone deposition and remodelling. In contrast, control bones (catheters installed--no hyperthermia) showed much less ossification, with many areas of thin incomplete osteoid. Further, bones treated with hyperthermia only (no surgical trauma) showed no such changes. Thus, it appears that following an initial insult, hyperthermia promotes bone deposition.

Animals↗
PubMedDate not supplied

Human Mycobacterium bovis infection in the south-west of Ireland 1983-1992: a comparison with M. tuberculosis.

Epidemiological and bacteriological aspects of human Mycobacterium bovis disease were investigated in south-west Ireland (counties Cork & Kerry, population 536,000) over the years 1983-92 inclusive and compared to M. tuberculosis. Results showed a small, stable incidence of culture positive M. bovis human disease, mean annual incidence 0.56 per 100,000 population compared to a higher but declining incidence of culture positive M. tuberculosis (15.3 per 100,000 in 1983, 9.0 per 100,000 in 1992). Male patients were the majority, 63.4 per cent of M. bovis; 62.4% of M. tuberculosis (p = 0.03). Fifty three per cent of M. bovis cases (n = 30) were pulmonary, compared to 85% of M. tuberculosis (n = 626; p = 0.0001). M. bovis patients were older (p = 0.02), mean age 58.4 years (SD 18.9) compared to 48.5 (SD 22.2). The mycobacterial smear positive rate was similar in both groups taken as a whole. No rural-urban difference in incidence was found in either disease, suggesting in the case of M. bovis initial infection in childhood via contaminated milk in the pre-pasteurisation era.

Animals↗
PubMedDate not supplied

Results and lessons to be learned from a waiting list initiative.

Varicose veins are a major and increasing burden on the health service with waiting lists growing in the majority of units. Most successive Governments have funded waiting list initiatives to deal with this problem. We report the results of a one year varicose vein waiting list initiative which dealt with a total of 1104 patients. A standard triage regime was established. Two hundred and eighty five patients were removed from the waiting list due to failure to attend, surgery performed elsewhere, medically unfit or no longer wishing to have surgery. There were 63 late cancellations and 23 operations were cancelled following admission due to unrelated medical complications. Planned operating lists worked well and complications were uncommon. Several important lessons were learnt during this initiative and recommendations are made with regard to the optimal method of dealing with the problem of varicose veins.

Delivery of Health Care↗