Search PubMed⌕ Search

Biomedical subjects

J Wallwork

Publications and source records attributed to J Wallwork.

At least 325 records · Page 18Linked to original sources
PubMed1984

Metabolic changes in the autotransplanted baboon heart.

Chronic denervation of the heart leads to depletion of tissue catecholamines, giving rise to metabolic abnormalities, including a reduction in cardiac glucose oxidation. Impaired glucose oxidation could cause an increased oxidation of fat, which in turn could lead to development of coronary artery disease. Cardiac glucose oxidation (using 14C-(U),D-glucose) was studied in female baboons, before, and three to five weeks after, autotransplantation. Systemic arterial and coronary sinus samples were analyzed for total CO2 content, O2 content, 14CO2, glucose, lactate, pH, PCO2, and PO2. Tissue for metabolite assays (adenosine-5'-triphosphate [ADP] and creatine phosphate [CP]; glucose-6-phosphate [G6P] and fructose 6-phosphate [F6P] was obtained from the right ventricle before and after autotransplantation in some animals. There were no significant changes. Tissue was also obtained postmortem for analysis of noradrenaline, soluble tyrosine hydroxylase activity, and contractile and regulatory proteins. There was a large decrease in tissue noradrenaline, suggesting almost total sympathetic denervation. The level of tyrosine hydroxylase activity shows that the denervated heart can synthesize dopamine. There were no detectable changes in the contractile or regulatory proteins. In six of the nine baboons successfully studied, there was a distinct decrease in the oxidation of glucose after autotransplantation (P less than 0.05). This indicates that the removal of the sympathetic and parasympathetic nerve supply to the heart affects the ratio of glucose oxidized to other substrates.

Adenosine Triphosphate↗
PubMed1983

Diagnosis and treatment of allograft rejection in heart-lung transplant recipients.

Six patients received heart-lung transplants between March, 1981, and January, 1982. There were four women and two men between 26 and 45 years of age, three with primary pulmonary hypertension and three with congenital heart disease and pulmonary hypertension (Eisenmenger's syndrome). Immunosuppression was primarily with cyclosporin-A, with additional corticosteroid, azathioprine, and rabbit antihuman thymocyte globulin. Six episodes of allograft rejection in four patients (10, 11, 21, 24, 53, and 86 days after transplantation) were detected by means of transvenous endomyocardial biopsy. All patients experienced pulmonary edema early after transplantation (reimplantation response), and two patients required mechanical ventilatory support for allograft rejection at 10 and 11 days. Treatment of rejection consisted of intravenous methylprednisolone (four episodes) or augmented oral prednisone (two episodes), with resolution. No episode thought to be pulmonary rejection has occurred in the absence of cardiac findings. Four patients are alive from 6 to 15 months after transplantation and are functionally normal. Early experience with heart-lung transplantation suggests (1) that allograft rejection can be detected by cardiac findings and successfully treated by augmented corticosteroids, (2) that lung rejection does not occur in the absence of cardiac findings, (3) that the frequency and severity of rejection episodes are not greater than with standard cardiac transplantation, and (4) that the frequency of rejection episodes is highest within the first 60 days after transplantation.

Adult↗
PubMed1982

The use of 111In-labeled lymphocyte imaging to evaluate graft rejection following cardiac transplantation in dogs.

Lymphocytes separated from venous blood from six dogs who had heterotopic cardiac transplants have been labeled using 111In-oxine. Labeled lymphocytes were reinjected into the dogs and imaging of the heart carried out over the successive 3 or 4 days. For comparison serial ECGs and punch biopsies of the heart were obtained. Abnormal uptake of labeled lymphocytes in the donor heart was clearly visible in three of the six dogs, faintly visible in two and not seen in one. 630 mu Ci 111In was used in the dog where no uptake was seen and subsequent studies showed this amount of the radiopharmaceutical was toxic to lymphocytes. In the remaining five dogs the mean ratio of uptake of 111I in donor to recipient heart was 14:1 (range 6.5:1--21:1). The lack of substantial uptake in the transplanted heart of two dogs in attributed to a delay in rejection relative to the time the labeled lymphocytes were injected. The results suggest that 111In-labeled lymphocytes have potential as a noninvasive test for detecting rejection of cardiac transplants.

Animals↗
PubMed1982

Cardiac transplantation in perspective for the future. Survival, complications, rehabilitation, and cost.

Two hundred twenty-seven cardiac transplant procedures have been performed in 206 patients from January, 1968, to April, 1981. Postoperative survival rates, calculated by the actuarial method for program years 1968 to 1973 (66 patients), are 44%, 33%, 27%, 21%, and 18% at 1, 2, 3, 4, and 5 years after transplantation, respectively. Postoperative survival rates for program years 1974 to 1981 (140 patients) are 63%, 55%, 51, 44%, and 39% at 1, 2, 3, 4, and 5 years after transplantation, respectively. This increase results primarily from improvement in survival achieved in the first 3 postoperative months (59% +/- 7%, 1968 to 1973, versus 80% +/- 40%, 1974 to 1980), reflecting improved patient management. Infection remains the primary cause of death following transplantation (76/131 patients, 58%), followed by acute rejection (24/181, 18.3%), graft arteriosclerosis (14/131, 10.7%), and malignancy (6/131, 4.6%). The development of graft arteriosclerosis has been examined in 85 one-year survivors studied by annual coronary arteriograms. Coronary lesions of varying severity have developed in 21 patients. HLA-A2 incompatibility was associated with a higher incidence of graft arteriosclerosis than was apparent for all other A locus incompatibilities (p less than 0.0003). Lymphoma has been shown to be associated with younger recipient age, a primary disease diagnosis of idiopathic cardiomyopathy, and retransplantation. One hundred six patients have survived at least 1 year after transplantation; 97% were in NYHA Class 1 at that time interval and 82% returned to employment or activity of choice. The longest survival time is new 11 years, 3 months. Cardiac transplantation can be considered "reasonable and therapeutic treatment to extend life" in selected individuals.

Actuarial Analysis↗
PubMed1980

The acute abdomen following cardiopulmonary bypass surgery.

Over a 5-year period, 9 patients (0.85 per cent) developed a major acute abdominal complication after cardiopulmonary bypass surgery. Difficulties in the initial recognition and diagnosis of these complications in sedated, ill patients are highlighted. A high index of suspicion is important in the early diagnosis of these complications. The numbers are too small for statistical analysis, but experience suggests that each case should be dealt with on its merits in accordance with common surgical practice and that operative management should not be rejected because the patient has recently undergone a major cardiac operation.

Abdomen, Acute↗
PubMed1978

Return to work after coronary artery surgery for angina.

The working habits of 115 consecutive patients who underwent coronary artery vein bypass grafting for angina were assessed. Only 25 patients worked up to the operation. Seven patients were housewives and seven retired. Sixty-eight patients had had to give up work because of their angina pectoris, and most of these had been off work for between six months and two years. After the operation 75 patients returned to full-time work, 59 within two to six months. These 75 patients included 23 of the 25 at work preoperatively and 47 of the 68 unable to work preoperatively. Most patients returned to their original occupation. We conclude that coronary artery surgery, as well as bringing symptomatic relief, increases the patient's ability to return to and maintain gainful employment.

Adult↗
PubMed1976

Surgical management of ventricular septal defect complicating myocardial infarction.

In an 18 month period six patients were treated by operation for ventricular septal defect occurring as a complication of acute myocardial infarction. Each septal defect occurred within one week of the myocardial infarct but the interval from infarction to operation ranged from 8 days to 7 months. All patients had intractable cardiac failure and two were in cardiogenic shock at the time of operation. Preoperatively right and left heart catheterisation with left ventriculography and biplane coronary arteriography was performed in every case. At operation the principle of "total correction" of all the cardiac defects was followed so that in addition to closure of the septal defect each patient required one or more additional operative procedures such as resection of left ventricular infarct or aneurysm, mitral valve replacement or coronary artery vein bypass grafts. All six patients survived operation but one died four weeks postoperatively from perforation of an acute peptic ulcer. In one patient the ventricular septal defect recurred and was successfully closed four months later. The surviving patients remain well at follow-up.

Acute Disease↗