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Biomedical subjects

R C Kester

Publications and source records attributed to R C Kester.

At least 91 records · Page 5Linked to original sources
PubMed1989

Intravenous oxypentifylline in critical limb ischaemia.

In an open tolerability study, 36 consecutive patients with critical ischaemia of the lower limbs were treated with intravenous oxypentifylline 1, 200 mg daily for up to three weeks. Patients were assessed objectively using a radioisotope limb blood flow technique and a subjective assessment of the patient's pain was made using linear analogue pain scores and analgesia scores. Treatment was well tolerated in 34 patients but was discontinued in two because of significant side effects. Fifty per cent of the remaining patients avoided surgical reconstruction or amputation and were discharged home on oral oxypentifylline. The results of the radioisotope limb blood flow study showed no change following treatment but the pain scores and analgesia scores decreased significantly in the patients who avoided surgical treatment. Intravenous oxypentifylline is usually well tolerated and may be a useful adjunct to the treatment of critical ischaemia where reconstructive surgery is impossible or undesirable. This type of treatment warrants study in a double-blind, placebo-controlled trial.

Administration, Oral↗
PubMed1989

The clinical application of forearm and hand blood flow measurements using a gamma camera.

A new method of measuring blood flow to forearms and hands during reactive hyperemia is described. Subjects are positioned with forearms and hands over a gamma camera, and the circulation below the elbows is isolated for 4 minutes with pneumatic cuffs. The remaining blood pool is labeled with technetium-99m-labeled human serum albumin given via a vein in the dorsum of the foot. The rate of rise of activity in the arms after cuff release is measured from the gradient of time activity curves, and these are calibrated for flow by counting a sample of venous blood. Blood flow per unit volume is obtained from measurements of the limb volume, done by water displacement. Results for eight normal control subjects showed a mean flow per unit volume to forearm plus hand of 32.9 +/- 6.4 ml/100 ml/min and to hand alone 36.5 +/- 6.9 ml/100 ml/min. Case studies of patients with a variety of large- and small-vessel diseases are presented, illustrating the use of the technique to aid diagnosis and measure response to treatment.

Adult↗
PubMed1989

Forearm blood flow measurements using technetium-99m human serum albumin following brachial arteriotomy.

A simple, low cost method for measuring forearm blood flow during reactive hyperemia has been developed. Subjects are seated with hands and forearms over a large field-of-view gamma camera. Blood pressure cuffs inflated above the elbows isolate the blood in the forearms and hands and induce a hyperemic response. The remaining blood pool is labeled with technetium. The rate of increase of activity following release of the cuffs is measured from the gradient of time-activity curves and is calibrated for flow by counting a venous blood sample. The technique has been applied to a group of normal controls and to symptomatic and asymptomatic patients following right brachial arteriotomy. Forearm blood flow in normal subjects was 32.9 +/- 6.4 ml/100 ml/min and for subjects with occlusion of the brachial artery was 6.4 +/- 2.1 ml/100 ml/min. The method is simple, widely available, and reproducible. The good signal to noise ratio allows it to be used in cases of very low flow either as an aid to diagnosis or to measure treatment response.

Adult↗
PubMed1988

The effect of indobufen on the thrombogenic potential of a Dacron prosthesis in an artificial circulation.

We have evaluated the effect of indobufen on the potential thrombogenicity of a Dacron vascular prosthesis in an artificial circulation. In a randomised double blind crossover study, ten healthy volunteers received indobufen 200 mg or placebo twice daily for one week. The artificial circulation, incorporating a 15 cm length of 8 mm Dacron graft was perfused for 60 mins with volunteer blood containing autologous 111In labelled platelets. Graft thrombogenicity was assessed by changes in platelet function, isotope labelled platelet studies and scanning electron microscopy. Platelet count fell significantly during graft perfusion (P less than 0.05) and aggregation was significantly inhibited by treatment with indobufen pre perfusion compared with the placebo group (P less than 0.02). While deposition of labelled platelets was not statistically significant, consumption of these platelets was greater in the placebo group (P less than 0.01). Field counts of adherent platelets made from scanning electron micrographs of the indobufen treated group were significantly lower (P less than 0.01) compared with the placebo group. We conclude that indobufen can reduce the thrombogenic potential of Dacron vascular grafts and suggest that it may be an effective antiplatelet agent for use following Dacron bypass surgery.

Blood Vessel Prosthesis↗
PubMed1988

A study of fucidin uptake in ischaemic tissues.

Twenty-five patients undergoing vascular surgery were given Fucidin 500 mg t.d.s. for the 3 days prior to surgery. Serum and fat levels obtained at the time of surgery show that the antibiotic is well absorbed and penetrates relatively ischaemic tissues. The levels obtained greatly exceed the MIC for Staphylococcus aureus.

Adipose Tissue↗
PubMed1987

Use of a gamma camera for measuring limb blood flow in peripheral vascular disease.

A method for measuring limb blood flow during reactive hyperaemia is described. Pneumatic cuffs inflated to 300 mmHg are used to isolate the blood in the limbs from the rest of the circulation. The remaining blood is labelled with technetium. The increase in radioactivity in the limb following release of the cuffs is measured using a gamma camera. The mean rate of flow of blood to the limb (in ml (100 ml)-1 tissue min-1) is derived from the graph of radioactivity versus time and from the radioactivity in a sample of venous blood. The results of measurements carried out in patients with peripheral vascular disease (30 limbs) and normal controls (24 limbs) are presented. Repeated studies in 10 subjects (20 limbs) showed the method to be highly reproducible at high and low flow rates (r = 0.99). Case studies illustrating the use of the method as a screening test for peripheral vascular disease and to monitor the effects of treatment are presented.

Aged↗
PubMed1987

A reliable and readily available method of measuring limb blood flow in intermittent claudication.

To evaluate isotope limb blood flow measurement in intermittent claudication we have assessed 58 non-diabetic patients comparing our new method with treadmill testing and Doppler assessment. Limb blood flow was applicable to all 58 patients; 25 patients were unable to walk on a treadmill and of the 33 who could 12 failed to walk for one minute, making a standard one minute exercise test inappropriate. In those patients who could perform exercise tests there was a significant correlation between maximum walking distance and limb blood flow (r = 0.35, P = 0.02). Resting, post-exercise and post-hyperaemic ankle-brachial systolic pressure indices bore no relationship to the maximum walking distance. Isotope limb blood flow measurement is reproducible (r = 0.97), can be applied to those patients who cannot walk on a treadmill and provides information about both legs. It correlated significantly with all the other tests and can be recommended for the minimally invasive assessment of intermittent claudication.

Adult↗
PubMed1986

The concentration of latamoxef achieved in the bile and gallbladder wall of patients with cholecystitis.

This study reports the clinical and pharmacokinetic results following an injection of latamoxef (moxalactam disodium) in patients undergoing cholecystectomy for symptomatic cholelithiasis. Two groups were involved in the study. Group A consisted of 22 patients who received 1 g of intramuscular latamoxef at the time of premedication prior to surgery, and group B consisted of 12 patients each of whom received an intravenous dose of 0.5 g of latamoxef at the time of anaesthetic induction. Latamoxef levels were then measured in peripheral blood, gall bladder bile, common bile duct (CBD) bile and gall bladder wall. Despite a significant difference in the sampling times, inhibitory levels were obtained in the majority of samples in both groups, singularly high levels being assayed in CBD bile. We conclude that an intravenous dosage of latamoxef (0.5 g) given with anaesthetic induction is as effective as 1 g intramuscular dosage given with the pre-medication.

Adolescent↗
PubMed1985

Comparison of the thrombogenicity of four types of knitted Dacron arterial graft in an artificial circulation.

The thrombogenicity of four types of knitted Dacron arterial graft was compared by measuring the effect of each prosthetic graft on human platelet function in an artificial circulation. The grafts examined were plain knitted (Meadox 'Cooley'), knitted double velour (Meadox 'Microvel'), filamentous external velour (U.S.C.I. 'Sauvage Filamentous') and a plain knitted graft with a pyrolytic carbon coating (Meadox 'Carboknit'). Platelet count, adhesion and percentage aggregation were all decreased during perfusion. The greatest changes in these parameters were produced by the filamentous velour graft and the least by the carbon coated graft. Electron microscopy demonstrated significantly more platelets adherent to the filamentous graft (rho less than 0.01) with changes in platelet morphology indicating activation. These results suggest that the filamentous graft is more thrombogenic than the other grafts.

Blood Vessel Prosthesis↗
PubMed1984

The penetration of latamoxef disodium (moxalactam) into the subcutaneous fat and skeletal muscle of ischaemic lower limbs with atherosclerotic disease.

After pre-operative administration of 1 g, latamoxef disodium (moxalactam) levels were measured in peripheral venous blood, skeletal muscle and subcutaneous fat sampled from 29 patients during either arterial reconstruction or amputation undertaken for arterial occlusive disease. Tissue samples were taken from both proximal and distal levels in the amputated limbs. Levels of latamoxef disodium were above the minimum inhibitory concentration required for most commonly encountered Gram-positive and Gram-negative organisms. No patients developed toxicity or superficial wound infection but there was one vascular graft infection by Candida albicans. It has been shown that latamoxef disodium penetrates rapidly into the subcutaneous fat and skeletal muscle of relatively ischaemic limbs, achieving levels inhibitory to many common pathogens.

Adipose Tissue↗
PubMed1984

Does oxpentifylline ('Trental') have a place in the treatment of intermittent claudication?

In a randomized double-blind study, the clinical and haemorrheological responses of 40 patients receiving oxpentifylline (200 mg 3-times daily) were compared with those of 40 patients receiving placebo. The treatment period in both groups was 2 months. The parameters measured before and after treatment were: subjective response; claudication and maximum walking distances; ankle systolic indices; maximum blood flow in the lower limb by gravimetric plethysmography; plasma fibrinogen; erythrocyte deformability and whole blood viscosity. There was a significant increase (p less than 0.05) in mean erythrocyte deformability in the oxpentifylline group but not in the placebo group; this apparent difference between the groups, however, was not significant. The placebo group showed a significant improvement (p less than 0.05) in claudication distance and mean plasma fibrinogen concentration, but no such improvements were observed in the oxpentifylline group. There were no significant differences in either of the two groups with regard to the subjective response, ankle systolic indices, maximum limb blood flow or whole blood viscosity. It is concluded that oxpentifylline , when taken in oral form at the dose used in this study, increased erythrocyte deformability without conferring any clinical or haemorrheological benefit to patients with intermittent claudication.

Adult↗
PubMed1984

The thrombogenicity of Dacron arterial grafts and its modification by platelet inhibitory drugs.

When blood flows through Dacron arterial grafts, platelets adhere in large numbers to the luminal surface of the grafts. Different types of commercially available Dacron grafts vary in their level of thrombogenicity. This thrombogenic response has been evaluated in an artificial circulation and in patients with Dacron aorto-bifemoral grafts, and the response can be modified by the use of platelet-inhibitory drugs. A double blind trial has shown that when a combination of aspirin and dipyridamole is administered to patients with femoro-popliteal Dacron bypass grafts, then the patency rate of these grafts can be significantly improved.

Arteries↗
PubMed1983

Results of vascular reconstruction with double velour Dacron in patients with critical lower limb ischaemia.

The results of 65 arterial reconstructions with double velour Dacron carried out for limb salvage have been reviewed. Successful revascularization was achieved initially in 86%, and the peri-operative mortality was 9.0%. Cumulative salvage was greater in patients with aorto-iliac disease (65% at 5 years) than in those with femoropopliteal disease (36% at 5 years). Results were poorest in patients with gangrene or marked trophic changes at presentation, in those with distal disease and in those who required revisional surgery.

Adult↗