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Biomedical subjects

S Jameson

Publications and source records attributed to S Jameson.

At least 37 records · Page 2Linked to original sources
PubMed1991

Complications associated with retained pacemaker leads.

Retention of functionless pacemaker leads may occur following mechanical or infective problems (potentially or definitely infected) or after electrical failure of the lead. One hundred nineteen patients with a pacemaker lead (or leads) retained between 1970 and 1990 were reviewed retrospectively. Lead retention after an intervention dictated by potential or definite infection of the pacing system resulted in complications in 27 of 53 patients (51%), which in 22 patients (42%) were major (septicemia, superior vena cava syndrome, and further surgery under general anesthesia for recurrent "infective" problems) including three deaths. Complications were less likely if lead retention occurred after electrical failure with three minor and two major (surgery under general anesthesia, superior vena cava syndrome) complications in 66 patients (P less than 0.001). Bacteriology of swabs taken at the time of retention in the patients with potential or definite infection was unhelpful in predicting future complications: 8/18 patients (44%) whose swabs were negative had complications of which 5/18 (28%) were major. In our experience retention of functionless pacemaker leads after an intervention dictated by potential or definite infection of the pacing system, is associated with significant morbidity and mortality and should be avoided.

Adolescent↗
PubMed1990

Atrial antitachycardia pacing in patients with supraventricular tachycardia: clinical experience with the Intertach pacemaker.

During a 3-year period, 22 patients with recurrent supraventricular tachycardia have been treated with antitachycardia pacemakers (Intermedics Intertach, 262-12, n = 17, and Intertach II, 262-16, n = 5). Eighty-two percent were female, the mean age was 44 +/- 14 years; 86% had atrioventricular node reentrant tachycardia. Symptoms had occurred over 11.8 +/- 7.1 years, with 3.6 hospital admissions per patient, despite 4.7 +/- 2.1 antiarrhythmic drugs. Following pacemaker implantation, during a follow-up of 14.8 +/- 11.5 months, only two patients have been readmitted to a hospital because of supraventricular tachycardia (mean 0.1 per patient). One patient is taking an antiarrhythmic agent, and four are taking beta adrenergic blocking agents. Thus, 23% are taking cardioactive drugs (it was anticipated that two patients would continue on drugs after pacemaker implantation). There have been no serious complications. Atrial antitachycardia is thus an effective therapy in carefully selected patients with recurrent supraventricular tachycardia, reducing hospital admissions for supraventricular tachycardia and reducing the need for antiarrhythmic drugs.

Adrenergic beta-Antagonists↗
PubMed1989

Do electrode and lead design differences for permanent cardiac pacing translate into clinically demonstrable differences? (Comparison of sintered platinum and activated vitreous and porous carbon electrodes).

A randomized prospective study was undertaken to compare the electrical performances of three permanent, endocardial, tined pacing leads with different electrode designs--sintered platinum, vitreous carbon, and porous carbon. Ninety-nine patients received one of the leads (S80 31; 423S 32; S100 36). Acute R wave amplitude and ST elevation of the native endocardial electrogram, voltage threshold, impedance, and current flow at four pulse durations (0.25-1.0 msec) were measured. Voltage thresholds were measured noninvasively at each of four pulse durations at 2 days and 1, 3, and 6 months after implantation. No significant differences were found in sensing properties, or current flow at threshold at 0.5 msec pulse duration. The 423S lead had a significantly higher impedance at threshold and both a higher impedance and lower current flow at 5 V. No significant differences in threshold voltages were found between the three leads at any pulse duration, at any of the assessed times after implantation. Six-month thresholds for the S80, 423S, and S100 leads were 1.18 +/- 0.35, 1.17 +/- 0.29, and 1.06 +/- 0.38 V respectively at 0.5 msec pulse duration. Differences between 'high performance' pacing leads need to be of a greater order of magnitude before they can be exploited to give any real clinical advantage to patients.

Aged↗
PubMed1987

"Are the differences between 'high performance' pacing leads clinically significant? A comparison of sintered platinum and activated carbon".

A retrospective assessment was performed of the acute implantation characteristics of two pacing leads, one with a sintered platinum (S 80-T) electrode and the other with an activated vitreous carbon (412-S) electrode in 124 patients. The S80-T lead had a significantly lower implantation threshold. The differences between the two leads in sensing properties, in current flow at threshold voltage and at the output of the generator were not significant at implantation. The 412-S lead had a higher impedance measurement than the S-80-T at implantation but this was mainly due to the resistance differences of the conductors rather than to electrode-patient interactions. A subgroup of 20 patients had chronic threshold measurements. The S 80-T lead had a significantly lower chronic voltage threshold. However because the acute and chronic differences are small we conclude that, although these differences are statistically significant, they are not clinically significant. Both can justifiably be termed 'high-performance' leads.

Adult↗
PubMed1985

Copper malabsorption in coeliac disease.

Copper uptake during three hours from an oral test dose of copper sulphate solution giving three mg Cu++, close to the recommended daily dietary intake, was significantly reduced in patients with proximal intestinal disease, compared with normal subjects. Three out of ten patients had abnormal and otherwise unexplained blood counts compatible with the known haematological effects of copper deficiency and were restored to normal levels on a gluten-free diet. Copper deficiency and proximal intestinal disease should be suspected in patients with otherwise unexplained anaemia, especially neutropenia.

Adult↗
PubMed1985

Limited benefit of treatment of diabetic polyneuropathy with an aldose reductase inhibitor: a 24-week controlled trial.

The effects of the aldose reductase inhibitor, sorbinil, on symptomatic symmetrical diabetic polyneuropathy were studied during a 6-month period in a double-blind parallel group placebo-controlled trial. Twenty-seven patients received sorbinil and 28 placebo. The patients were assessed by clinical examination, neurophysiological measurements, sensory threshold determinations and tests of autonomic nerve function. No major clinical benefit was seen in the sorbinil-treated patients and no differences in sensory thresholds were observed. In three out of nine neurophysiological tests (motor nerve conduction velocity of the posterior tibial nerve, F-wave latency and sensory distal latency of the ulnar nerve) and one out of five tests of autonomic nerve function (heart rate variation during deep breathing) significant differences between the patient groups evolved in favour of sorbinil treatment. An overall evaluation of the temporal development of these and remaining neurophysiological and autonomic variables suggested a small but significant benefit from sorbinil treatment. There was no evidence of continuing improvement throughout the treatment period and beneficial effects observed were no greater than those seen in previous trials of considerably shorter treatment periods. It is concluded that sorbinil treatment results in some improvement in peripheral nerve function in symptomatic diabetic polyneuropathy, but that the long-term effect may be of limited value.

Adult↗
PubMed1985

Effects of long-term ketoconazole therapy on serum lipid levels.

Serum cholesterol and triglycerides were determined in 36 patients receiving an 8-month course of oral ketoconazole 200 mg/day in order to study its effect on lipid metabolism. The mean serum cholesterol concentration had decreased by 15% (p less than 0.001) after 1 month, but on continued medication it returned to the pretreatment state; after discontinuation of therapy it increased transiently by 13% (p less than 0.001). Triglycerides increased during ketoconazole administration and at the end of the trial the mean triglyceride concentration was 48% higher than the baseline value (p less than 0.02). Although most lipid values during therapy lay within the normal ranges, 6 patients developed transient hypertriglyceridaemia. There was no correlation between the changes in lipids and peak serum ketoconazole levels. In one subject studied in more detail the concentration of very low density lipoprotein triglycerides rose during therapy, whereas high density lipoprotein cholesterol decreased slightly. The lipoprotein lipase activity in muscle and, in particular, in adipose tissue was significantly suppressed during ketoconazole treatment. Serum lipids and, if possible, serum lipoproteins should be carefully monitored in patients receiving long-term oral ketoconazole therapy.

Adipose Tissue↗
PubMed1984

Pharmacokinetics of cimetidine in advanced cirrhosis.

The effect of impaired liver function on the pharmacokinetics of cimetidine was studied in 8 patients with advanced cirrhosis given single doses of 100 mg i.v. and 400 mg p.o. on separate days. Compared to a control group of 10 healthy volunteers, the total renal and nonrenal clearance was significantly reduced in the cirrhotic patients; (total plasma clearance mean +/- SD) 356 +/- 181 vs 789 +/- 262 ml/min (p less than 0.01); renal clearance (Clr) 296 +/- 100 vs 588 +/- 181 ml/min (p less than 0.01) and nonrenal clearance ( Clnr ) 97 +/- 111 vs 205 +/- 89 ml/min (p less than 0.05). Compared to published results for age-matched ulcer patients, both total and nonrenal clearance were lower whereas renal clearance was within the reported normal range. A significant reduction in volume of distribution (Vd beta) was found, from 2.1 +/- 0.1 l/kg in controls to 1.0 +/- 0.4 l/kg, and in the patient group there was a significant correlation between Vd beta and total plasma clearance (r = 0.72, p less than 0.05). Volume of distribution in steady state (Vdss) did not differ from published results in age-matched controls. No significant change in half-life was found. Bioavailability, estimated by AUC-measurement, showed considerable patient variability (21-143%), with a mean of 70 +/- 39%. This was lower than in the controls. In contrast, measurement of urinary excretion showed higher bioavailability in the patients (66 +/- 23 vs 51 +/- 8%). No correlation was found between any of the kinetic parameters and the clinical and laboratory data.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1981

Zinc deficiency with transitory acrodermatitis enteropathica in a boy of low birth weight.

A premature male baby fed on his mother's milk developed zinc deficiency and a skin disorder inseparable from acrodermatitis enteropathica. Following zinc therapy the skin lesions healed. Later the treatment was withheld and no recurrence was seen during 30 months' observation. The boy's zinc deficiency was thought to be due to a high requirement secondary to rapid growth, to poor zinc supply in food and, possibly, to inefficient zinc absorbtion.

Acrodermatitis↗
PubMed1981

Effects of aldose reductase inhibitor treatment in diabetic polyneuropathy - a clinical and neurophysiological study.

The efficacy of treatment with an aldose reductase inhibitor (1,3-dioxo-1 H-benz-de-isoquinoline-2(3H)-acetic acid, AY-22,284, Alrestatin) on peripheral nerve function in diabetic polyneuropathy was assessed. Thirty patients with long-standing diabetes and slight to moderate neuropathy participated in the double-blind placebo trial. Clinical examination, sensory threshold determinations for vibratory, tactile and thermal stimuli, conduction velocity measurements and studies of automatic function were performed to evaluate the treatment. Significant differences favouring Alrestatin over placebo were found for many of the measured variables, whereas no changes occurred on placebo. The apparent improvement of neuropathy occurred despite persisting hyperglycaemia. The results indicate that aldose reductase inhibitor treatment may be of value in diabetic polyneuropathy, and provide support for the sorbitol pathway hypothesis of diabetic polyneuropathy.

Adult↗
PubMed1979

Treatment of acute nonlymphoblastic leukemia in adults with daunorubicin-DNA complex: a preliminary report.

Forty-four adult patients under 60 years of age with acute nonlymphoblastic leukemia were randomized for induction treatment with one of the following three regimens: R 1 = courses of daunorubicin on day 1 + ARA-C on days 1--5; R 2 = courses of daunorubicin on days 1 and 2 + ARA-C on days 4--8; R 3 = courses of daunorubicin-DNA complex on days 1--2 + ARA-C on days 4--8. Out of 14 patients, 9 went into remission on R 1, 6 out of 14 on R 2, and 8 out of 16 on R 3. The preliminary results suggest that daunorubicin-DNA complex has the same efficacy for inducing remission as daunorubicin alone, if the same time intervals and dosages are used.

Acute Disease↗
PubMed1978

Oxymetholone treatment in myelofibrosis.

In order to study the effect of oxymetholone therapy in advanced myelofibrosis, 11 patients (4 females, 7 males) were given, 3--5 mg per kg body weight, long-term oxymetholone treatment in a prospective multicenter study. Five cases had previously had a diagnosis of polycythemia vera. All patients had anemia initially, 4 leukocytopenia and 10 thrombocytopenia in addition. Hepato-splenomegaly was present in all cases but in varying degree. Five patients required regular blood transfusions before treatment. In 9 of the 15 courses given, there was normalization of the peripheral blood or substantial improvement (better than 3 g hemoglobin/dl or 50 X 10(9) platelets/1) after androgens. Significant effects were noted both on hemoglobin values and platelet counts. The need for blood transfusions ceased completely in all 5 cases. When oxymetholone treatment was reduced or interrupted 4 patients relapsed; 2 of them responded to a renewed course. The red cell counts returned to previous polycythemic values in one patient and another died from acute leukemia. The results of this study suggest that androgens might be of value in advanced cases of myelofibrosis with transfusion-requiring anemia or severe thrombocytopenia.

Aged↗