Biomedical subjects
Publications and source records attributed to C Ward.
In 14 of 15 patients initially suspected of having infective endocarditis echocardiography accurately predicted the final diagnosis. Echocardiography is particularly valuable in culture negative cases and in excluding patients with other conditions whose clinical features mimic those of infective endocarditis. The presence of fibrosed aortic valve cusps resulted in one false positive diagnosis of valvular vegetations.
The Escherichia coli strain, ts-rnp5, originally described in 1975 by G. D. Burdick and H. Berger, is shown to possess an RNA polymerase (RNA nucleotidyltransferase) sigma subunit with an activity 4--6 times less thermostable at 45 degrees than sigma from wild-type strains. This defect remains associated with the sigma polypeptide through a variety of purification stages, including renaturation of sigma after its elution from sodium dodecyl sulfate/polyacrylamide gels. The mutation responsible for decreased thermostability of sigma, called rpoD1, cotransduces with dnaG and therefore is located at about 66 min of the E. coli genetic map.
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We developed a two-site immunoradiometric assay for rat serum ferritin that uses antibody immobilized on agarose. Individual serum ferritin values were significantly correlated with iron stores as determined chemically by liver ferritin iron content. This group correlation was not sufficiently great, however, to allow confident prediction of iron stores in a given animal on the basis of serum ferritin alone. Significant differences in mean liver ferritin iron concentration between groups of rats raised on diets of differing iron content were not always reflected by differences in mean serum ferritin values. Data correlating the serum levels of ferritin and a liver-specific transaminase suggested that hepatocellular death may sometimes contribute ferritin to the serum. Strong postitive correlations between serum ferritin and iron stores in the rat were not observed when serum transaminase levels were in the normal range.
A study of twenty-five cases of prosthetic valve endocarditis suggests that the antibiotics used for perioperative prophylaxis may alter the type and antibiotic sensitivity of organisms which subsequently infect the artificial valves. Based on the results of this study, the authors have been able to modify their prophylactic regime to encompass these organisms and to predict the antibiotics most likely to be effective in the treatment of prosthetic valve endocarditis in their unit. No single prophylactic or therapeutic regime will be equally effective in all centres, but by examining the different types and sensitivities of bacteria which cause prosthetic valve endocarditis in a locality, antibiotic regimes can be chosen which best suit the local situation.
Analysis of the HLA antigen patterns in patients with acquired valvular heart disease showed that antigens A29 and AW30/31 occurred more often in those patients whose valvular disease was not preceeded by a history of rheumatic fever or chorea. Patients with no rheumatic history but with antigen A29 or AW30/31 had clinical features that distinguished them from others with valvular disease--namely, (a) isolated mitral valve disease and (b) the need for surgery, often at an early age, after a relatively short duration of symptoms.
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A clinicopathological study of the 1972-1973 A2 England influenza epidemic is presented. In fatal cases early necrosis of myofibrils was present in those patients who died within 24 hours of the onset of the influenza symptoms. At 5 days gross changes were present. These were largely resolved by the eighteenth day of illness. In 42 patients treated at home, transient ECG changes were found in 18 cases. These included ST-segment deviation, T-wave inversion, flattening of the T wave, sinus bradycardia, sinus tachycardia, nodal rhythm, and atrial fibrillation. Permanent changes were observed in one patient and in an additional patient admitted to hospital with permanent A-V block.
There are many similarities between the clinical features of viral heart disease and of rheumatic carditis, as defined in the revised Jones criteria for the diagnosis of rheumatic fever. Because of this, it is likely that viral heart disease has been, and still is, diagnosed as rheumatic. This situation can be avoided if isolated rheumatic carditis is diagnosed only when a viral etiology has been definitely excluded, and when there is unequivocal evidence of recent infection with an appropriate strain of streptococcus.
The frequency of HLA antigens was determined in 133 patients with acquired valvular heart disease and compared with the frequency of HLA antigens in 1,000 normal individuals by the relative incidence ratio method of Woolf (1955). No significant increases were observed. However, when the patients were divided into those with no rheumatic history and those who have had rheumatic fever or chorea, a significant increase in AW 30/31 and A29 was observed in the group with no rheumatic history.
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Five hundred and eighty six patients with mitral valve disease were studied with cardiac catheterization between 1961 and 1972; 48 (8.2%) had extreme pulmonary hypertension (resting systolic pulmonary artery pressure of 80 mmHg or above and pulmonary vascular resistance of 10 units or greater) and of these patients, 27 underwent cardiac surgery. The operative mortality for mitral valvotomy was 11 per cent and for mitral valve replacement 56 per cent. The overall mortality was 31 per cent. The risks of operation were increased in those with a long history of cardiac symptoms, those over 50 years of age, and in the presence of associated aortic valve disease. The mean survival for those patients not having operation was only 2.4 plus or minus 0.5 years. The mean follow-up period for those surviving operation has been 5.8 plus or minus 0.6 years, and symptomatic improvement has been good.
In a study of 45 cases of ventricular pre-excitation, 19 were classified as type A and 20 as type B according to Rosenbaum's criteria, which depend on the polarity of the major deflections in the right praecordial leads and not, as is commonly thought, on the direction of the delta vector. Six cases that could not be classified as type A or type B were termed intermediate. Vectorcardiograms were recorded from 29, and these showed a wide but continuous range of values for both the delta and the main QRS vectors in all three planes. Any classification based on these features must, therefore, depend on arbitrary quantitative data. Three patients in this series had associated right bundle-branch block. A review of the published reports on the association of pre-excitation and bundle-branch block failed to provide a rational basis for the classification of pre-excitation. It is emphasized that Rosenbaum's classification is empirical and its validity is questioned.
Triosil 370 has been compared with Urografin 76, and Hypaque 65 by injecting identical volumes into the coronary arteries of human subjects in the course of coronary arteriography. The injection times used were the same and neither the patient nor the coronary artery catheter were moved between injections. The order in which the solutions compared were injected was alternated. The deviation in the ST segment and of the T wave which resulted from the injection was measured. The Triosil caused significantly less change than Urografin and Hypaque. A numerical expression of the T wave deflection derived from the data showed Triosil:Hypaque:Urografin equals I:2.6:2.9.
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