Search PubMed⌕ Search

Biomedical subjects

C M Burke

Publications and source records attributed to C M Burke.

At least 55 records · Page 3Linked to original sources
PubMed1987

Primary pulmonary hypertension. Length of survival in patients referred for heart-lung transplantation.

The paucity of data on the natural history of primary pulmonary hypertension (PPH), and the observation that some patients awaiting heart-lung transplantation (HLT) appeared to be living longer than expected, led us to analyze the survival data of patients with PPH who had been referred for consideration of HLT. Ninety patients (female: male = 3.6:1) met clinical and hemodynamic criteria for PPH. Age at diagnosis was 29.8 +/- 7.9 years (mean +/- SD) (range 13-48 years). Symptom duration was 65.9 +/- 47.4 months, while survival from diagnosis was 42.9 +/- 42.6 months, giving a mean lead time of 23 months. Mean pulmonary artery pressure (PAP) at diagnosis was 61.6 +/- 15.0 mm Hg. The incidence of patent foramen ovale (PFO) was 19 percent, postpartum onset 16 percent, family history 6 percent, and cirrhosis 3 percent. The survival of 27 patients who died without operation was 50.3 +/- 52.5 months (median 37 months), with a symptom duration of 68.4 +/- 57.5 months (median 64 months). Both a high mean right atrial pressure (RAP) (p less than 0.025) and high mean PAP (p less than 0.025) correlated inversely with survival. For the whole group, none of the variables, age at diagnosis, sex, mean PAP or mean RAP at diagnosis, symptom duration prior to diagnosis or the presence of a PFO, postpartum onset or positive family history, significantly influenced survival. However, a low cardiac output (p less than 0.05) adversely influenced prognosis. The discrepancy between the mean and median length of survival in our group and previous reports confirms the need for further clarification of natural history and for appropriate clinical trials to assess therapeutic endeavors.

Adolescent↗
PubMed1987

Cardiopulmonary function at maximum tolerable constant work rate exercise following human heart-lung transplantation.

Studies were performed measuring parameters of respiratory and circulatory function at rest and during maximum tolerable constant work rate treadmill exercise in 16 clinically well patients who had undergone heart-lung transplantation for end stage pulmonary hypertension. Ten patients were studied before and within eight weeks following transplantation. Long-term function with exercise was further evaluated with follow up studies at one year (n = 10) and two years (n = 6), posttransplantation. Posttransplant gas exchange and ventilation during exercise are essentially normal with neither being limiting to maximal exercise. Exercise capacity is significantly improved posttransplant, primarily as a result of improvement in the circulation over that found pretransplant in uncorrected pulmonary hypertension. Although improved, circulatory limitations of maximal exercise may still persist. Cardiorespiratory function at maximum tolerable exercise is well maintained following heart-lung transplantation for at least two years, providing no complications occur. This suggests that denervation of the heart and lungs, disruption of the bronchial circulation and pulmonary lymphatics, and the graft ischemia encountered at the time of transplantation impose no serious limitations on long-term cardiopulmonary function. The overall functional capacities of the transplanted heart and lungs are more than adequate for meeting the activities of normal life.

Adult↗
PubMed1987

Lung immunogenicity, rejection, and obliterative bronchiolitis.

Evidence suggests that obliterative bronchiolitis (OB) following human heart-lung transplantation is a form of allograft rejection related to augmented expression of class II major histocompatibility complex antigens (MHCII) on airway epithelium and mediated by activated T cells. Other forms of OB, including those related to viral infection and autoimmune disease, may reflect a similar mechanism.

Bronchitis↗
PubMed1987

Obliterative bronchiolitis after heart-lung transplantation: apparent arrest by augmented immunosuppression.

Obliterative bronchiolitis has been the major complication in long-term survivors of human heart-lung transplantation at our institution. We have assessed the effect of the introduction of a third immunosuppressive agent, azathioprine, on the rate of decline in airflow variables in eight heart-lung transplant recipients with obliterative bronchiolitis, and have compared this rate with that in five patients who did not receive augmented immunosuppressive therapy. Specifically, the rate of decline in forced expiratory flow rate between 25% and 75% of vital capacity improved considerably after institution of this therapy (-5.25 +/- 2.85 compared with -0.27 +/- 0.66 [mean +/- SD]; p less than 0.005), whereas the effect on the ratio of forced expiratory volume in one second to forced vital capacity was more modest (-3.61 +/- 1.52 compared with -0.54 +/- 0.93; p less than 0.005). The rate of decline in airflow variables was similar in both groups before the institution of therapy with azathioprine. These results show that augmented immunosuppressive therapy is capable of slowing the rate of progression of obliterative bronchiolitis in this population; they also suggest that the obliterative bronchiolitis may represent a form of chronic pulmonary allograft rejection.

Adult↗
PubMed1987

Familial Prader-Willi syndrome.

Three adult sisters with previously unrecognized Prader-Willi syndrome (PWS) demonstrated the six diagnostic features of this congenital condition: neonatal hypotonia, hypomentia, hypogonadism, obesity, short stature, and dysmorphism. Detailed endocrine investigations were performed, including ovarian biopsy in the propositus. HLA genotype A2 was present in each patient. The normal high-resolution prometaphase karyotypes indicated heterogeneity; the absence of the deletion 15q12 frequently found in patients with sporadic PWS distinguished this sibship as representing a possible autosomal recessive type of PWS. Current evidence suggests that the diagnosis of PWS may be often overlooked. Increased clinical awareness of the features of PWS should result in prompt diagnosis and optimal management of affected patients, together with increased understanding of this enigmatic condition.

Adult↗
PubMed1986

Twenty-eight cases of human heart-lung transplantation.

Between March, 1981, and August, 1985, twenty-eight heart-lung transplant operations were done in 27 patients at a single institution. 8 patients died in the perioperative period and adhesions related to previous thoracic surgery proved to be a major risk factor for postoperative haemorrhage. Obliterative bronchiolitis developed in half of the 20 long-term survivors, a mean of 11.2 months (range 2-35 months) after surgery: 4 of these patients died, 3 are functionally limited, 2 were successfully treated with corticosteroids, and the remaining patient was successfully retransplanted. The other 10 long-term survivors returned to a normal life with essentially normal pulmonary function measured at a mean of 22.6 months (range 4-42 months) after transplantation. All the surviving patients have evidence of renal impairment related to cyclosporin nephrotoxicity. The results indicate that, although heart-lung transplantation is compatible with essentially normal long-term pulmonary function, the procedure should not yet be regarded as a routine clinical intervention.

Airway Obstruction↗
PubMed1986

Pulmonary arteriovenous malformations: a critical update.

Although first reported 90 yr ago, the natural history of pulmonary arteriovenous malformations (PAVM) is still incompletely understood. We review historical perspectives and pathologic classification of this rare disease and identify etiologic factors and clinical features in the 450 reported cases. The many different diagnostic modalities currently available are described, and a logical sequence of investigations is suggested. Pulmonary angiography remains mandatory prior to definitive treatment. The available evidence strongly suggests that morbidity and mortality in untreated PAVM exceeds that associated with either surgical resection or embolic occlusion. Thus, definitive treatment should be offered in all cases, with the possible exception of asymptomatic patients with small lesions who have no evidence of Osler-Weber-Rendu disease. Embolotherapy is now the treatment of choice in institutions with the necessary expertise and facilities, notwithstanding the absence of long-term follow-up for patients treated this way. It is suggested that increased documentation of long-term morbidity and mortality in both treated and untreated patients with PAVM will lead to greater understanding and more effective management of this enigmatic condition.

Adolescent↗
PubMed1986

Augmented ventilatory response to exercise in pulmonary hypertension.

The ventilatory response to submaximal exercise, defined as the slope of minute ventilation over carbon dioxide production (VE/VCO2), was determined in 12 normal subjects, ten patients with pulmonary hypertension before and after heart-lung transplantation, and eight patients following heart transplantation. Patients with pulmonary hypertension show an augmented ventilatory response compared to normal subjects (pulmonary hypertension [mean, 57.7 +/- 6.8 (SE) ml/ml VCO2; normal subjects, 22.3 +/- 1.4 ml/ml VCO2; p less than 0.001]). Following heart-lung transplantation, VE/VCO2 slope fell to 24.7 +/- 1.6 ml/ml VCO2, a value which is not significantly different than the value in normal subjects. Patients after heart transplantation show a mean slope value of 25.3 +/- 1.3 ml/ml VCO2, which is not significantly different than the normal value or the value found after heart-lung transplantation. The augmented ventilatory response to exercise did not correlate with the usual chemical modulators of ventilation (arterial pH, arterial carbon dioxide tension, or arterial oxygen tension). These results suggest the following: the existence of a neural system in patients with pulmonary hypertension which results in an augmentation of ventilatory drive in response to exercise; the augmented ventilatory response reflects excessive neural activity of pulmonary afferents during exercise; narrow regulation of the ventilatory response to exercise in normal subjects which is preserved in the denervated lung, indicating that pulmonary afferents are not critical to ventilatory control during exercise in the normal subject; and the possible use of measurements of the ventilatory response to exercise as a noninvasive screening test for pulmonary hypertension.

Adult↗
PubMed1986

Primary pulmonary hypertension and pregnancy.

Despite the preponderance of primary pulmonary hypertension (PPH) in young female subjects, documented cases of PPH in association with pregnancy are uncommon. During a 12-month period, 73 female patients with PPH were evaluated as potential recipients of a heart-lung transplant; and in six (8 percent), PPH appeared to be related to pregnancy. Histologic confirmation of the diagnosis was available in four patients, and other causes of pulmonary hypertension were excluded as far as possible in the remaining two patients.

Adolescent↗
PubMed1986

The recrudescent epidemic of retrolental fibroplasia.

We are probably observing a recrudescent epidemic of RLF which has elicited surprisingly little attention from the medical community. Given present data, it is not unreasonable to conclude that there is a true epidemic and that its etiologic basis involves a population of infants with high susceptibility to oxygen toxicity whose oxygen status is being monitored by methods which are not sufficiently accurate to provide the necessary narrow limits of permissible O2 administration. A clinical trial which looked at the outcome of premature infants with and without transcutaneous O2 monitoring would be useful not only to determine the impact on the prevalence of RLF, but also to determine the role of this technology in the management of premature infants generally.

Disease Outbreaks↗
PubMed1986

Steroid-responsive bronchiolitis after human heart-lung transplantation.

This report describes the clinical course of a patient who developed obliterative bronchiolitis after viral infection on three separate occasions. Long-term follow-up is given. It is suggested that the syndrome of late pulmonary deterioration after transplantation may be steroid responsive if treatment is initiated early in the natural history of the syndrome. In addition, it is suggested that increased emphasis should be placed on the documentation of viral infection in transplant recipients to define a possible interaction between infection and rejection.

Adult↗