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Biomedical subjects

J M Porter

Publications and source records attributed to J M Porter.

At least 271 records · Page 15Linked to original sources

Finger gangrene caused by small artery occlusive disease.

Available evidence indicates that about one third of all patients presenting with localized finger gangrene developed the condition due to intrinsic occlusions of the small arteries of the hand and fingers caused by one of a variety of systemic diseases. We have treated 35 such patients in the past seven years. A variety of diagnostic tests allowed the establishment of the diagnosis of connective tissue disease in 14 patients, hypersensitivity angiitis in 13 patients, arteriosclerosis in five patients, and myeloid metaplasia, calciphylaxis, and carcinoma in one patient each. Treatment with cold and tobacco avoidance, vasodilators, and local debridement produced good results without amputation in 30 patients. Five patients required partial phalangeal amputation. These results suggest that appropriate diagnostic tests will allow an accurate diagnosis in all patients, and that the natural history is that of spontaneous improvement without major tissue loss. In our experience, surgical sympathectomy plays no role in the treatment of these patients.

Adolescent↗

Anglo-French contrasts in medical practice.

Medical practice in a British and French town was compared. The British and French general practitioners (GPs) and specialists were observed for one session each, and questionnaires were presented to the doctors and to samples of the inhabitants. Style of practice may largely determined by fiscal factors.

Adult↗

Design of mirror systems for commercial vehicles.

This paper describes a computer aided design project for the evaluation of alternative mirror systems for a range of commercial vehicles. Computer modelling of mirror systems introduces the ergonomics parameters into the design programme at an early stage. The flexibility of computer modelling allows a far greater range of designs to be evaluated. The problems can be studied and resolved before producing a series of mirror designs to be evaluated by more conventional techniques on prototype vehicles. Mirrors designed in this way are less likely to require major redesign. Compliance with the legislative requirements of mirror design was a major consideration. Attempts were also made to optimise mirror systems for a range of cabs basing the evaluations on ergonomic as well as legislative criteria. Additionally, consideration was given to the use of mirrors for viewing trailer swing, passenger exit surveillance (for public service vehicles) and the viewing of objects close to high cabs. SAMMIE (System for Aiding Man-Machine Interaction Evaluation), a computer-aided workplace and work task design system, was used to model the vehicles and to produce the required mirror views on a computer graphics terminal.

Journal Article↗

Human umbilical cord vein allograft arteriovenous fistula for chemotherapy access.

Seven patients who received chronic chemotherapy and required vascular access underwent construction of an arteriovenous fistula of the leg using gluteraldehyde-tanned human umbilical cord vein allografts. No wound or graft complications have occurred and patient tolerance of the operative procedure and subsequent use of the fisulas for chemotherapy has been excellent. Our preliminary results suggest that the use of umbilical vein allograft arteriovenous fistulas is quite satisfactory for long-term chemotherapy access.

Adult↗

Surgical treatment of chronic visceral ischemia.

Our experience with the operative repair for chronic visceral ischemia in eight patients, including two patients without visceral ischemic symptoms, is described. We prefer revascularization of as many vessels as possible and have used a small diameter Dacron bifurcation graft directed cephalad from the infrarenal aorta to the superior mesenteric artery and hepatic or splenic artery in four patients. One patient died postoperatively of an arrhythmia. Three patients died of unrelated causes 7 to 36 months after surgery. Four patients are alive 8 to 48 months after surgery. All patients were relieved of the intestinal ischemic symptoms by surgery.

Aorta, Abdominal↗

Antigenicity of venous allografts.

With isolated exceptions, the clinical use of venous allografts has been disappointing. Considerable evidence indicates that allograft antigenicity plays a major role in the failure of venous allografts when used as arterial replacements. Recent reports suggest that DMSO-cryopreservation of venous allografts may reduce allograft antigenicity while preserving allograft viability. The present study examines the effect of modifications of vein allografts on subsequent allograft antigenicity. Skin grafts were transplanted from ACI to Lewis inbred strains of male rats. Primary skin graft rejection occurred in 9.0 +/- 1.0 days. Subcutaneous implantation of fresh inferior vena cava from ACI rate into Lewis rats resulted in subsequent skin graft rejection in 5.0 +/- 1.0 days, confirming the antigenicity of venous tissue. Cryopreservation of ACI inferior vena cava for seven days prior to implantation, with or without 15% DMSO, resulted in subsequent skin graft rejection in 5.0 +/- 1.0 days. Treatment of ACI inferior vena cava with 0.30% gluteraldehyde for 20 minutes prior to implantation in Lewis rats resulted in skin graft rejection in 9.0 +/- 1.0 days, the same time as a first set rejection. This study indicates that unmodified veins are normally antigenic and that this antigenicity is not eliminated by cryopreservation with or without DMSO. Gluteraldehyde treatment appears to reduce allograft antigenicity, but results in a nonviable graft. At the present time, there is no known way to reduce the antigenicity of viable venous allografts.

Animals↗

Stenosis of the popliteal vein caused by an osteochondroma of the distal femur: a case report.

This report describes a 14-year-old girl presenting with unilateral distal leg edema which developed on the basis of popliteal vein compression by a large osteochondroma of the distal femur. Excision of the osteochondroma relieved the venous obstruction, and the leg returned to normal. Lesions of tibial arteries and veins caused by osteochondromas of the distal femur are discussed.

Adolescent↗

Value of angiography in the management of abdominal aortic aneurysm.

The value of angiography in the management of abdominal aortic aneurysms (AAA) was assessed in 100 consecutive patients with AAA. Angiographic information influenced management decisons and/or surgery performance in 75: In 23 patients at high risk for surgery because of associated medical problems, it helped in deferring surgery; in 52 patients it resulted in a change of operation from a standard aneurysm resection with conventional grafting to a more conservative procedure (three patients), more extensive grafting (45 patients) and/or the addition of other vascular reconstructions (32 patients). Angiography is considered an integral step in the routine preoperative workup of AAA and is particularly valuable for the determination of important anatomic details about the aneurysm (upper and lower extensions, relation to the renal arteries), the detection of associated vascular disease (of renal, visceral, pelvic and peripheral arteries), and the demonstration of aberrant renal arteries and collateral visceral circulation. Catheter techniques are considered most suitable and safe for examination of AAA.

Aged↗

The role of arteriography in abdominal aortic aneurysm.

The results of arteriography in the management of 100 consecutive patients with abdominal aortic aneurysms are presented. Arteriographic information had substantial influence upon management decisions and performance of surgery in 75 per cent of cases. We found the preoperative knowledge of the precise vascular pathology or anatomic variants not only permitted a more rational recommendation for or against surgery but aided in the selection of the most suitable surgical procedure.

Aged↗

Lower extremity amputation for ischemia.

Three hundred-twenty-four amputations of the lower extremity for ischemia at the University of Oregon Health Sciences Center over the past ten years are presented. Striking differences between the first and second five-year periods are noted in level of amputation. The primary healing rate of all patients in the two periods was similar. Diabetics tended to have more distal amputations but primary healing was lower than that of nondiabetics.

Amputation, Surgical↗

The clinical use of fibrinolytic agents.

Two fibrinolytic drugs, streptokinase and urokinase, have undergone extensive clinical evaluation in the past fifteen years. Current evidence suggests that these agents may become the drugs of choice in the treatment of certain patients with venous thrombosis and pulmonary embolism. The ultimate usefulness of fibrinolytic therapy in the treatment of thrombotic conditions other than venous thrombosis and pulmonary embolism has not yet been determined.

Endopeptidases↗

The role of the platelet in coagulation and clinical thrombotic events.

There have been exciting advances in our understanding of platelet function in recent years. Platelet physiology, drugs that inhibit platelet function, and the current evidence supporting the use of platelet-inhibiting drugs in the prevention of clinical thrombotic events are reviewed.

Blood Coagulation↗