Topologic forms of mitochondrial DNA in AKR mice.

Circular dimer forms of mitochondrial DNA were found in leukemic and preleukemic AKR mice but not in nonleukemic animals. There was a positive correlation between the presence of circular dimers and progression of the disease, the leukemic mice having the greatest evidence of circular dimers. This finding suggested that the occurrence of early subcellular changes is an important cellular modification in the leukemogenic process.

Early and long-term results of coronary artery bypass grafting with severely depressed left ventricular performance.

The effects of coronary artery bypass grafting (CABG) on ventricular performance and long-term clinical status were studied in 18 consecutive patients with disabling angina pectoris and severely depressed left ventricular (LV) performance (ejection fraction [EF] 27 +/- 9%). All patients survived CABG, although 1 patient had a perioperative myocardial infarction. There was no change in LVEF at rest, 29 +/- 12%, in the other 17 patients. However, LVEF during peak exercise increased from 22 +/- 7% to 27 +/- 14% (p less than 0.05). The 17 patients were separated into 2 groups: those who increased their peak exercise LVEF by at least 10% (group A, 8 patients) and those who increased it by less than 10% (group B, 9 patients). Preoperatively, patients in group A had a higher LVEF at rest (p less than 0.001) and smaller end-systolic and end-diastolic volumes at rest (p less than 0.001) and during exercise (p less than 0.005). Preoperatively, the LVEF in group A decreased with exercise, from 36 +/- 4% to 27 +/- 5% (p less than 0.01), but was unchanged in group B (19 +/- 3% vs 17 +/- 4%, difference not significant). After CABG, patients in group A had a smaller increase in end-systolic volume with exercise than those in group B (13 +/- 7 vs 34 +/- 22 ml/m2, p less than 0.05), but the changes in end-diastolic volume with exercise were not significantly different. At 27 +/- 5 months after CABG, 5 of 8 patients in group A were asymptomatic.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical use of the dexamethasone suppression test for psychiatric disorders. Need for sensitive method for measuring corticosteroids and cautious interpretation of results.

The corticosteroid levels in 256 plasma samples from 112 patients with the clinical diagnosis of depression were assayed in two ways: by the routine method (sensitivity of 5 to 40 micrograms/dl) and by a newer, more sensitive method (sensitivity of 1 to 10 micrograms/dl). Of the 152 "true-negative" samples measured by the more sensitive method, 81 (53%) were reported as positive ("false-positive") by the routine method. The routine method does not yield accurate results on borderline levels of corticosteroids (5 to 7 micrograms/dl) for the dexamethasone suppression test for psychiatric disorders.

Plasma levels of cortisol, corticotropin, and beta-endorphin in patients with major depression.

Efforts to elucidate the abnormal mechanism of corticotropin and beta-endorphin in major depression have yielded conflicting findings. The relationship of plasma levels of cortisol, corticotropin, and beta-endorphin in 42 patients with a Research Diagnostic Criteria diagnosis of major depression, endogenous subtype was examined. Following the DST, 32 patients were nonsuppressors and 10 were suppressors. The differences between the median values for plasma corticotropin and beta-endorphin immunoreactivity were not significant at any time of measurement after the DST.

Emergency treatment for primary Ewing's sarcoma of the ribs.

Two cases of primary Ewing's sarcoma of the ribs necessitating emergency treatment are reported. Treatment consisted of a combination of radiotherapy, chemotherapy, and surgical therapy. The operation was urgent and early in one patient and delayed in the other. Both remain disease free 12 and 14 months after operation, respectively.

Ligation of the patent ductus. Technical considerations at different ages.

Over a 10 year period, 185 patients have been treated for patent ductus, including nine premature infants with a respiratory distress syndrome. Thirty-five other infants have had duct obliteration during the neonatal period, the incidation for surgery being intractable heart failure. Six of 18 adults had calcification or aneurysm in the duct region. three of these required extracorporeal circulation for duct control and closure. The remaining patients were from 1 to 18 years of age and underwent elective duct obliteration. Double ligation of the duct is regarded as the simplest, safest, and quickest technique generally applicable. Special techniques are required for fragile, broad, calcified, hypertensive, and conical ducts.

Deep hypothermic arrest: observations on later development in children.

Thirty-two children were reviewed following closure of ventricular septal defect in infancy. Fifteen had undergone continuous perfusion and 17 had been subjected to core cooling followed by deep hypothermic arrest. Parental and professional evaluations of intellectual and motor development, at periods between 7 and 72 months following operation, suggest that there is a higher incidence of developmental abnormality in the subgroup treated with deep hypothermic arrest.

Combined carotid and coronary artery surgery: a review of the literature.

This article reviews 41 different reports that describe various means of surgical management of coexistent carotid and coronary artery disease in almost 1,500 patients. Stroke is the major risk for patients undergoing myocardial revascularization in the presence of symptomatic carotid artery disease or an asymptomatic carotid bruit that reflects an ulcerative lesion or stenosis exceeding 75%. However, patients with asymptomatic carotid stenosis should not routinely undergo prophylactic carotid endarterectomy. Myocardial infarction is the major hazard in patients undergoing carotid endarterectomy who have coronary artery disease. This risk is magnified when the disease is silent. A high level of awareness and rigorous screening are essential in all patients suspected of having coexistent disease. Although a protocol for the management of these patients is important, individual assessment is essential.

Ultra-low dose aprotinin decreases transfusion requirements and is cost effective in coronary operations.

BACKGROUND: The recommended dose of aprotinin has been shown to reduce blood loss and need for blood transfusions, but the cost precludes its routine use. This study was designed to determine whether a less expensive, ultra-low dose of aprotinin is effective when used in coronary artery bypass grafting with left internal mammary artery. METHODS: Patients (n = 202) were randomized to receive either placebo or aprotinin, 0.5 million KIU before incision and 0.5 million KIU during initiation of cardiopulmonary bypass. Differences in quantity of blood transfused were analyzed. Further groups were analyzed to account for the effect of aspirin. Multivariable analysis was performed to determine risk factors for transfusion. Direct costs of blood products and aprotinin were tabulated for each group. RESULTS: There was an important reduction in the proportion of patients transfused, and number of blood units transfused when aprotinin was given before coronary artery bypass grafting. These differences were even more important in patients on aspirin preoperatively. Independent predictors for increased number of transfusions were aspirin continued before operation, smaller body surface area, and the use of placebo instead of ultra-low dose aprotinin. There was no difference in morbidity between treatment groups. There was a reduction in direct costs associated with the use of aprotinin. CONCLUSIONS: These data support the routine use of aprotinin 1 million KIU in coronary artery bypass grafting with left internal mammary artery to reduce cost and transfusion requirements.

Coexistent carotid and coronary arterial disease. Outcome in 50 cases and method of management.

The coexistence of coronary and carotid arterial disease in the same patient requires that particular measures be undertaken to avoid the risks of myocardial infarction and stroke. The last 50 patients requiring operations on both subsystems and with no mortality and minimal morbidity are reported. A method for the management is described, to allow discrimination between those patients needing a combined coronary-carotid procedure and those in whom the operations should be staged. The application of this protocol to the last 1732 patients who presented with coronary and/or carotid artery disease has resulted in all overall mortality of 0.63% and morbidity of 0.17%.

Constrictive pericarditis associated with trauma and pectus excavatum.

A case of constrictive pericarditis is reported in a 31 year old man with pectus excavatum. The constriction was secondary to an organized traumatic pericardial haematoma immediately behind the pectus deformity.

Current management of coarctation of the aorta.

A series of 55 surgically treated cases of coarctation of the thoracic aorta is presented with an operative mortality of 5-4%. The problems encountered in infants are discussed and postoperative complications in adults and children detailed. The advantages of patch graft aortoplasty over resection and end-to-end anastomosis are described.

The spine and surgical treatment in osteogenesis imperfecta.

In the osteogenesis imperfecta patient, spinal deformity should be expected, particularly in the severely affected nonambulator with chest deformity. Curves develop early (age five to six) and generally progress rapidly. Early bracing, although somewhat effective, may well compress the soft osteoporotic rib cage without controlling the spinal curvature. The pulmonary compromise created by the scoliosis is compounded by the chest cage deformity secondary to bracing. In the patient with severe disease (thin bones and numerous fractures), posterior correction and fusion, with or without Harrington instrumentation, is the preferred approach. This should be done early as the osteoporotic bone does not tolerate the hook forces well; the correction is correspondingly limited. The use of methylmethacrylate bone cement around the hook provides redistribution of forces and more stable fixation. In the patient with mild disease (thick bones and few fractures) treatment should be similar to that of patients with idiopathic scoliosis. The chest cage should be carefully observed to avoid deformity from placement of the lateral or posterior pad.