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Biomedical subjects

J R Pepper

Publications and source records attributed to J R Pepper.

137 records · Page 8Linked to original sources
PubMed1980

Severe heart failure in child with ventricular septal defect and acute tricuspid regurgitation.

A case is reported in which acute tricuspid regurgitation developed in a child with a ventricular septal defect resulting in a left ventricular-right atrial shunt. This was successfully treated by closure of the defect and tricuspid valve replacement. The anterior leaflet of the tricuspid valve was almost completely destroyed by endocarditis, though in previous reports of tricuspid valve endocarditis in association with ventricular septal defect in children, it has beem invariably the septal leaflet which is damaged.

Child, Preschool↗
PubMedDate not supplied

Hemodynamic and emotional responses to a psychological stressor after cardiac transplantation.

OBJECTIVE: Because cardiac transplantation entails neuronal decentralization, cardiac responses to a psychological stressor in transplant patients would be expected to rely on circulating hormonal factors and therefore to be delayed and prolonged. We tested this prediction by comparing stress responses after transplantation with those in patients with coronary artery bypass grafts (to control for experience of surgery) or heart failure (to control for heart disease). METHODS: Fifty-six transplantation patients, 66 bypass patients, and 40 patients with heart failure underwent a 10-minute, computer-generated, Stroop color-word conflict test. Heart rate and systolic and diastolic blood pressures were recorded continuously for 1 minute before, during, and 12 minutes after the stressor. Emotional state was measured periodically by questionnaires. RESULTS: All hemodynamic variables were increased by the Stroop test. There was a pattern of blunted response to the Stroop test after cardiac transplantation, particularly in comparison with bypass patients, and slower recovery in comparison with both control groups. Emotional stress responses were similar in each group. CONCLUSIONS: This pattern cannot be attributed to the experience of major heart surgery or to cardiac disease. Nor can it be explained by differences in central processing of stress. Correspondingly the changed hemodynamic response to the Stroop test after cardiac transplantation evidently does not affect patients' emotional responses. The hemodynamic findings are consistent with an increased reliance on hormonal rather than neuronal hemodynamic regulation after cardiac transplantation.

Analysis of Variance↗
PubMedDate not supplied

The stentless porcine valve.

Recognition of the long-term results of homografts has brought about a renewed interest in stentless valves. This has been matched by the introduction of several glutaraldehyde preserved porcine stentless prostheses. The early experience indicates that these valves are technically somewhat simpler to insert than homografts and are associated with satisfactory early and immediate-term results. In particular, they appear to offer an earlier and more complete resolution of left ventricular hypertrophy. Correct insertion of a stentless porcine valve needs meticulous attention to detail and awareness of the precise anatomical features of the aortic root, which is a complex structure. Although the myocardial ischemic and cardiopulmonary bypass times are longer for the more complex insertion of this prosthesis, our studies indicate that this has no serious disadvantage to the patient and is more than matched by an improved hemodynamic performance associated with more stable left ventricular function. The theoretical advantages of a stentless valve substitute in the aortic position seem clear. Further detailed prospective studies are needed to report on the long-term performance of this valve.

Animals↗
PubMedDate not supplied

Sequential oxidative damage, and changes in iron-binding and iron-oxidising plasma antioxidants during cardiopulmonary bypass surgery.

Cardiopulmonary bypass patients undergoing heart valve replacement surgery appear to be under oxidative stress, when compared with normal healthy controls, by showing increased levels of protein and lipid damage. During bypass surgery two further episodes of oxidative stress occur. The first is seen when patients are placed on extracorporeal blood circulation and oxygenation which results in a rise in lipid peroxides and thiobarbituric acid-reactive substances. The second phase of oxidative stress occurs during reperfusion of the myocardium following removal of the aortic cross clamp. Coincident with evidence of increased oxidative damage to lipids during these latter phases of oxidative stress were decreases in plasma iron-binding and iron-oxidising antioxidant activities.

Antioxidants↗
PubMedDate not supplied

Toxoplasmosis and heart transplantation.

Our experience of toxoplasmosis in a series of 33 heart transplant cases was reviewed. One fatal infection was observed in a "mismatched" seronegative recipient of a heart from a seropositive donor. Two similar mismatched cases were given pyrimethamine prophylaxis and remained well. One organ recipient was found to have primary toxoplasmosis during the immediate preoperative assessment. The patient was treated with conventional therapy and remained asymptomatic in the postoperative period. Secondary reactivation of chronic infection and diagnostic confusion caused by passively acquired antibody associated with blood transfusion were not recorded. False reactions were noted in dye and latex agglutination test results.

Antibodies, Protozoan↗
PubMedDate not supplied

Infective endocarditis in a heart transplant recipient.

A 38-year-old man underwent orthotopic heart transplantation because of heart failure caused by ischemic heart disease. Three months after the operation cholestatic jaundice related to azathioprine hepatotoxicity developed, necessitating supplementation of cyclosporine immunosuppression with prednisolone. Seven months after heart transplantation he had a septic right femoral embolus and, by transesophageal echocardiography, was found to have a vegetation on the anterior leaflet of the mitral valve. Treatment with appropriate antibiotics resulted in complete resolution of symptoms and healing of the vegetation. Six months after the episode he remains free of symptoms and has normal heart function.

Echocardiography↗
PubMedDate not supplied

Lung transplantation: effect of cyclosporine A on the frequency of cytolytic lymphocytes recovered from blood and the bronchoalveolar space.

The frequency of donor-specific cytolytic cells within the inflammatory infiltrate produced in the graft after canine unilateral lung transplantation was measured using a limiting dilution assay. Two groups of recipient animals were studied; animals in the first group were treated with oral cyclosporine A for 4 days after transplantation, after which the drug was withdrawn thereby allowing acute rejection to begin as evidenced by histologic examination; animals in the second group were treated with cyclosporine A for the duration of the experiment and developed a subacute, alveolar manifestation of rejection. Frequency analysis was performed for lymphocytes isolated from the peripheral blood and, using the technique of bronchoalveolar lavage, lung allograft for each recipient animal both before transplantation and at various times after the operation. The group of recipients that was treated with cyclosporine A for 4 days showed an increase in the frequency of donor-specific cytolytic cells in the blood and lavage-derived lymphocyte populations that reached peak values (four to eight and five to eighteen times the preoperative level, respectively) between days 9 and 14 after operation. The frequency of these cells remained constant at a preoperative level into the peripheral blood of recipient animals treated long term with cyclosporine A; however, the frequency within the graft-derived lymphocyte population increased to reach peak values (12 to 25 times the preoperative level) between days 5 and 15 after operation. In conclusion, these results show that although cyclosporine A modifies pulmonary rejection pathologic conditions, this drug does not prevent the sequestration of donor-specific cytolytic cells within the allograft.

Animals↗