Nuclear proteins associated with gene expression in mouse plasmacytoma cell lines.

Nucleoplasmic and non-histone chromatin proteins from two unrelated and four related mouse plasmacytoma cell lines have been analysed by biosynthetic labelling with [35S]-methionine followed by one- and two-dimensional polyacrylamide gel electrophoresis. We have attempted to find a relationship between the patterns of nuclear proteins and gene expression in mutant plasmacytoma cell lines. The majority of nuclear proteins are common to all of the cell lines studied as would be expected if the majority of nuclear proteins are concerned with functions common to all plasma cells. There are, however, both qualitative and quantitative differences in the nuclear protein patterns of mutant and parent cell lines which appear to correlate with differences in gene expression. The turnover of nuclear proteins in two of the cell lines, MOPC 315.40 (IgA producer) and MOPC 315.32 (lambda 2 chain producer) was studied using pulse-chase techniques.

Histamine release from human right atrium.

Histamine release has been detected biologically after exposure of human right atrial biopsy samples to compound 48/80. Human right atrial samples contain large quantities of histamine, 1035 +/- 65 ng/g fresh weight. Exposure of untreated electrically paced atrial strips to compound 84/80, 300 micro/ml, caused an increase in the force of atrial contraction similar to that caused by histamine. Pretreatment of strips with cimetidine, 3.16 x 10(-5) M, prevented the inotropic response to compound 48/80. It is concluded that mast cell degranulation in human atrial tissue can cause sufficient release of histamine to modify the function of the heart.

The binding of 14C-labelled acetylaminofluorene to nuclear proteins and DNA.

The covalent binding of acetylaminofluorene (AAF) to rat liver nuclear protein fractions and DNA has been examined after 2 doses of 14C-labelled carcinogen (100 micronCi intraperitoneally) given at 24-h intervals. Most of the AAF (approx. 80%) was bound to the NHP which had the highest specific activity, relatively small amounts were bound to histones, residual proteins and DNA. After 2 weeks the label was more evenly distributed but little remained bound to the DNA. Pre-feeding rats with phenobarbitone (1 mg/ml in drinking water) reduced binding in all fractions. Pre-feeding rats with sodium sulphate (1 mg/ml in drinking water) also slightly lowered the binding to all fractions. Isoelectric focusing analysis (in polyacrylamide gels) of the NHP showed a complex binding pattern with no one component predominantly labelled, variations in the pattern were found after feeding sulphate and phenobarbitone. Normal histone components in the histone fraction (acid extract) contained only 25% of the labelled carcinogen present.

Relief of superior vena caval syndrome with autologous femoral vein used as a bypass graft.

Two patients presenting with superior venal caval syndrome have been treated surgically. In one patient the obstruction was caused by benign idiopathic mediastinal fibrosis; in the other it was secondary to carcinoma. In both cases venous decompression was achieved by using a segment of autogenous femoral vein to bypass the obstruction.

Pseudolymphoma of the lung: a rare cause of a solitary nodule. A case report and review of the literature.

Pulmonary pseudolymphoma is a rare lesion; only 30 cases have been previously reported. It presents as a solitary nodule which clinically and roentgenographically can resemble bronchogenic carcinoma. A further case is reported in which preoperative needle aspiration cytology played a role in diagnosis. Although the lesion was originally believed to be benign, a review of the literature has revealed the apparent subsequent development of lymphoma in four cases. The significance of this is discussed, and the need for prolonged follow-up is emphasized, since the prognosis of untreated pseudolymphoma is unknown.

Sympathoadrenal function during cardiac operations in infants with the technique of surface cooling, limited cardiopulmonary bypass, and circulatory arrest.

The sympathoadrenal response to surface cooling, limited cardiopulmonary bypass, and deep hypothermic circulatory arrest was investigated in 22 infants undergoing correction of congenital heart defects. Surface cooling to 26 degrees C was associated with a significant rise in plasma epinephrine and norepinephrine levels. Both levels fell during the period of core cooling on bypass, presumably because of hemodilution. Following the period of circulatory arrest there was a rise in both catecholamine levels that correlated nonlinearly with the duration of circulatory arrest. The catecholamine levels remained high after rewarming until the chest was closed. The results suggest that this type of surgical procedure produces severe sympathoadrenal stress. The extremely high values found in the postarrest period in some patients, who had had a long period of arrest (greater than 40 minutes), may indicate hypoxic stress. The biological effect of high circulating plasma catecholamines during hypothermia is difficult to assess. The heart rate response to plasma catecholamine levels tended to diminish on cooling in our patients.

Effects of age and ischemic times on biochemical evidence of myocardial injury after pediatric cardiac operations.

INTRODUCTION: The vulnerability of pediatric myocardium to ischemia is poorly documented in the clinical setting. METHODS: Serial measurements of serum concentrations of myoglobin, the MB isoenzyme of creatine kinase, and cardiac troponins T and I and their respective areas under the curve were obtained, with particular reference to age and ischemic time, in 80 children undergoing cardiac operations. Sixteen (the control group) did not require cardiopulmonary bypass and 64 did. RESULTS: In the control group there were increases (p < 0.01) in myoglobin and creatine kinase MB isoenzyme but no increase in cardiac troponin T or I; by contrast, the group treated with cardiopulmonary bypass had significant increases in all four markers but with differing temporal patterns. Younger age (especially < 12 months) was a highly significant explanatory variable only for the release of cardiac troponins T and I, and ischemic time was a significant explanatory variable for the release of creatine kinase MB isoenzyme, cardiac troponins T and I, but not myoglobin. In comparison with previous studies in adults, creatine kinase MB and cardiac troponin T concentrations were three times greater in children than in adults. CONCLUSIONS: This study supports the specificity of cardiac troponins T and I as markers of myocardial injury after pediatric cardiac operations and defines the importance of age and ischemic time in determining their release. In comparison with previous data in adults, our results raise the possibility that the pediatric heart may be more vulnerable to the effects of ischemia and reperfusion. Cardiac troponins will permit comparison of new myocardial protective strategies or other potentially therapeutic myocardial interventions.

Sleeve lobectomy (lobectomy and bronchoplasty) for bronchial carcinoma.

We present a series of 90 patients who underwent sleeve lobectomy for malignant bronchial tumors at the Brompton Hospital, London, between 1964 and 1974. The operative mortality was low (1%), and technical complications were infrequent. Bronchial stenosis, which occurred in 6% of patients, was due to recurrence of tumor in 4% and cicatrization in 2%. The majority of patients had squamous cell carcinomas of the upper lobe (76/90). In this group, the 5-year survival was 71% when the hilar lymph nodes were clear of tumor at the time of operation and 17% when the hilar lymph nodes were involved. Because these 5-year survival figures suggest that tumor-free survival is not significantly compromised by this conservative approach, we believe that sleeve lobectomy rather than pneumonectomy should be considered the operation of choice for squamous cell carcinomas of the upper lobe orifice involving the main bronchus.

Vulnerability of paediatric myocardium to cardiac surgery.

OBJECTIVE: Myocardial injury is an important cause of mortality and morbidity after paediatric cardiac surgery. Data obtained from studies in animals imply that juvenile myocardium is more resistant to the effects of ischaemia and reperfusion than adult myocardium but there is little confirmatory evidence in the clinical setting. DESIGN: Prospective observational study of biochemical markers of myocardial injury in a paediatric population undergoing cardiac surgery. SETTING: Tertiary referral centre for paediatric cardiac surgery. PATIENTS: Forty patients undergoing paediatric cardiac surgery of varying complexity including closure of atrial and ventricular septal defects and arterial switch for simple transposition. A control group included patients undergoing thoracotomy for closure of a patent ductus arteriosus or repair of a coarctation. INTERVENTIONS: Serial measurements of myoglobin, the MB isoenzyme of creatine kinase (CK-MB), and the highly specific markers of myocardial damage cardiac troponin T (cTnT) and I (cTnI) were made before and 1, 6, 24, and 48 to 72 hours after operation. RESULTS: There were significant increases in myoglobin and CK-MB, but not cTnT or cTnI, in the control group. There were significant increases in the four biochemical markers in all the cardiac operations but especially in the ventricular septal defect and transposition group. Increases in CK-MB and cTnT were about five times greater than those previously reported in adult patients. CONCLUSIONS: (i) Cardiac troponins are more specific markers of myocardial injury in paediatric cardiac surgery than myoglobin and CK-MB. (ii) Paediatric myocardium seems to be more vulnerable to injury during cardiac surgery than adult myocardium.

The management of prosthetic valve endocarditis.

During the period 1970 to 1980 2,945 patients underwent valve replacement at the Brompton Hospital. Thirty-one (1%) patients subsequently developed prosthetic valve endocarditis (P.V.E.). Twenty-one (0.7%) patients developed endocarditis within two months of valve replacement. Ten patients were treated medically, with seven deaths, whilst four of the eleven surgical cases died. There were ten cases of late P.V.E. occurring between two months and eight years after initial valve replacement (0.12% per annum). Eight patients were treated surgically, with two deaths, whilst both medical cases died. Thus 67% patients were effectively treated by immediate valve replacement, whilst only 25% medical cases survived. Actuarial survival curves predict a 41% five-year survival following surgery for P.V.E. We stress the importance of early diagnosis of this condition and recommend immediate valve replacement in all patients with P.V.E. developing signs of haemodynamic failure.

Aorto-pulmonary window.

Aorto-pulmonary window (septal defect) is an uncommon congenital cardiac malformation accounting for only about 0.5% of the cases of congenital heart disease catheterised at our institution. Of 15 patients with this anomaly eight had associated cardiac malformations. Three patients presented in the neonatal period and in these patients the other cardiac anomalies (aortic interruption in two, pulmonary atresia in one) determined the clinical presentation and haemodynamic disturbance. A second group of five patients presented with heart failure during infancy and in these patients additional anomalies, present in three, were "incidental" findings. A third group of seven patients with similar physical signs but without heart failure did not present until after the first year of life and all were asymptomatic. Associated anomalies, present in two, were again "incidental" in that they did not influence the presentation. Of 12 patients without serious associated anomalies, five, operated on before 1970, had division and suture of the aorto-pulmonary window with one death. In two the defect was patched from the pulmonary artery but one required re-closure from the aorta. In six the defect was successfully patched from the aorta, which is now the preferred technique.