Biomedical subjects

T S O'Brien

Publications and source records attributed to T S O'Brien.

23 records · Page 2Linked to original sources

PubMed1993

Lower limb ischaemia in the octogenarian: is limb salvage surgery worthwhile?

Vascular surgeons are being asked to manage vascular disease in an increasingly elderly population, and advanced age may be considered a relative contraindication to limb salvage surgery with an amputation seeming the preferred option. We present a review of 50 patients over the age of 80 years, presenting with ischaemic rest pain, ulceration or gangrene of the lower extremity. Six patients were treated conservatively, four of whom died during the same admission. Only two patients proved suitable for transluminal angioplasty as the sole curative procedure. Twelve patients (24%) underwent primary amputation with a perioperative mortality of 3/12 (25%). Five patients (10%) had an iliac bypass procedure, and 25 patients (50%) were considered suitable for infrainguinal bypass. Of the latter group 14 had femoropopliteal bypasses, and 11 had femorodistal bypasses with an overall perioperative mortality of 3/25 (12%). Mortality at 6 months was high (33%) and was similar in both the grafted and amputation groups. Patients having reconstruction fared well in terms of independent mobility, use of long-term care, and length of hospital stay. Patients over 80 years of age with critical ischaemia should not be denied the opportunity of vascular reconstruction.

Age Factors↗

PubMed1990

Loss of true blue labelling from the medial septum following transection of the fimbria-fornix: evidence for the death of cholinergic and non-cholinergic neurons.

Many neurons in the medial septal nucleus lose their transmitter-associated enzyme staining following axotomy in the proximal fimbria-fornix (FF), but it is not clear if these neurons have died or persist in a shrunken and subfunctional state. To investigate this further, septal neurons projecting through the FF were labelled with the fluorescent dye, True blue, by retrograde transport from multiple bilateral injection sites in the hippocampus. True blue-labelled neurons and cholinergic neurons immunohistochemically stained for choline acetyltransferase (ChAT) were then quantitatively compared in neighbouring sections through the medial septum 28 days after complete unilateral transections of the proximal FF. The number of True blue and ChAT positive cells ipsilateral to the FF lesion showed significant (P less than 0.001) declines of 51.4% and 71.1%, respectively, relative to the unlesioned side. Cell loss was considerably more severe among large neurons, such that 78.0% and 92.7% of True blue and ChAT labelled cells larger than the normal mean, but only 40.1% and 68.0% of True blue and ChAT labelled cells smaller than the normal mean size were lost. This indicates either that larger neurons were more prone to cell loss, or that some (but not all) large neurons persisted in a shrunken form. Histograms showed no increase in cell number in any of the smaller size categories and a substantial decrease in most cases, indicating that shrinkage alone could not account for the loss of all large neurons. Since True blue can remain present in brainstem cholinergic neurons surviving for over 365 days after axotomy, loss of True blue suggests breakdown of membrane integrity and cell death.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1989

Nerve growth factor receptor immunoreactivity in the rat suprachiasmatic nucleus.

Using a monoclonal antibody, nerve growth factor receptor has been immunohistochemically identified within the suprachiasmatic nucleus of adult rats. Labelling was most intense in the ventral, lateral and caudal portions of the nucleus and appeared primarily associated with fibers and terminals. These were among the most intensely labelled fibers and terminals in the forebrain.

Animals↗

PubMedDate not supplied

Primary pneumococcal peritonitis.

Primary pneumococcal peritonitis is an uncommon condition which in the preantibiotic era was associated with a high mortality rate. We present two cases and discuss the aetiology, clinical features and management of this condition.

Adult↗

PubMedDate not supplied

Magnetic resonance imaging in congenital dysplasia of the hip.

This study was designed to determine the usefulness of magnetic resonance imaging (MRI) in managing congenital hip dysplasia and dislocation. We compared various hip parameters using bony and cartilaginous landmarks. MRI determined that the bony acetabular index (AI) accurately reflects the cartilaginous AI. Bony acetabular indices greater than 30 degrees indicated hip dysplasia, subluxation, or dislocation. MRI demonstrates qualitative information not available on plain films; however, it does not provide further quantitative data, so we do not recommend its routine use in the evaluation of congenital hip dysplasia. The true benefit of MRI may be its ability to identify a group of patients with bone dysplasia but normal cartilaginous growth potential.

Child↗