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Biomedical subjects

R M Donaldson

Publications and source records attributed to R M Donaldson.

At least 19 recordsLinked to original sources
PubMed1991

Treatment of complicated prosthetic aortic valve endocarditis with annular abscess formation by homograft aortic root replacement.

The outcome of 30 consecutive patients with active aortic prosthetic valve endocarditis and root abscesses treated by the technique of homograft aortic root replacement with reimplantation of the coronary arteries is detailed. The principles of this technique are the removal of all abscesses and infected areas likely to drain into the infected mediastinum, excision of infected tissues down to healthy noninfected tissue and replacement with an antibiotic-impregnated homograft aortic root. All patients had evidence of progressive cardiac failure and ongoing sepsis. Mean patient age (+/- SD) at the time of operation was 42 +/- 18 years. The mean number of previous aortic valve replacements per patient was 1.6 +/- 0.7; 14 patients (47%) had undergone greater than or equal to 2 previous replacements. At operation, aortic root abscesses were found in all patients; abscess extension to adjacent structures and partial valve dehiscence had occurred in 23. In-hospital death occurred in 9 (30%) of the 30 patients. The 21 hospital survivors have been followed up for a mean of 66 +/- 42 months (range 9 to 144). Overall, 17 (81%) of the 21 hospital survivors have remained free of major adverse events (recurrence of endocarditis, need for reoperation or death). The results of our study suggest that homograft aortic root replacement should be considered favorably in the treatment of patients with aortic prosthetic valve endocarditis and root abscesses.

Abscess↗
PubMed1990

Treatment adherence and risk of death after a myocardial infarction.

The relation of treatment adherence to mortality after a myocardial infarction was investigated among 2175 participants in the Beta Blocker Heart Attack Trial, which had data for measures of treatment adherence, clinical severity, and the psychological and social features that may influence post-infarction mortality. Overall, patients who did not adhere well to treatment regimen (ie, who took less than or equal to 75% of prescribed medication) were 2.6 times more likely than good adherers to die within a year of follow-up (95% confidence interval, 1.2, 5.6). Poor adherers had an increased risk of death whether they were on propranolol (OR = 3.1) or placebo (OR = 2.5). Furthermore, this increased risk of death for poor adherers was not accounted for by measures of the severity of myocardial infarction, sociodemographic features (eg, race, marital status, education), smoking, or psychological characteristics (high life-stress or social isolation).

Adult↗
PubMed1990

A new complication of coronary arteriography.

The introduction of a sharply angulated catheter through an arterial sheath for percutaneous coronary arteriography was associated in 7 cases with dissection of the iliac arteries; this extended to the lumbar aorta at the level of the coeliac axis. The catheter tip should be introduced gently and preferably straightened out with a good length of guide wire to avoid this complication.

Angiography↗
PubMed1990

Monoclonal antibodies to human intrinsic factor.

Mice were immunized with human intrinsic factor, and their lymph node cells were fused with a myeloma cell line by standard hybridoma techniques. Eleven of the resulting 227 hybridomas secreted immunoglobulin G capable of binding to intrinsic factor-cobalamin complex. Cloning by limiting dilution gave 6 clones secreting anti-intrinsic factor antibodies that bound human intrinsic factor-cobalamin complex with affinities of 13-116 nM; 3 antibodies also bound rabbit intrinsic factor-cobalamin complex. Five antibodies inhibited to some degree the binding of cobalamin by intrinsic factor, and 2 also prevented attachment of intrinsic factor-cobalamin complex to guinea pig ileal receptors. Anti-rabbit intrinsic factor antibodies specifically precipitated a peptide of molecular weight 53,000, corresponding to the molecular weight of rabbit intrinsic factor from homogenates of rabbit gastric mucosal explants biosynthetically labeled with [35S]methionine and from culture medium in which the explants were incubated. Indirect fluorescence immunocytochemistry with the antibodies in human and rabbit gastric mucosal sections showed intense selective staining of parietal cells. These results (a) document species differences between human and rabbit intrinsic factors not previously demonstrable with polyclonal anti-intrinsic factor sera; (b) confirm earlier evidence that cobalamin binding and receptor functions occur at separate sites in intrinsic factor; and (c) provide a useful approach to studying structure-function relations of the intrinsic function molecule.

Animals↗
PubMed1988

Acute hemodynamic effects of celiprolol.

Beta-adrenoceptor blockade is an effective treatment for ischemic heart disease and hypertension, but the more widespread use of beta antagonists is limited by their bronchoconstrictor, vasoconstrictor and negative inotropic properties. Celiprolol has been shown in preclinical studies to be a beta 1-selective antagonist with bronchosparing and vasodilating properties, but without any cardiodepressant effect. This has been confirmed by clinical studies undertaken to date. The aim of the present study was to examine the acute effects of intravenous celiprolol on the cardiac hemodynamics of patients pretreated with oral atenolol.

Adult↗
PubMed1988

Detection of valvar obstruction by intracardiac masses using Doppler echocardiography.

The purpose of this paper was to examine valvar involvement in patients with intracardiac masses. Seven patients with intracardiac masses were studied by cross-sectional and Doppler echocardiography. In one, a candida vegetation on a mitral Starr-Edwards prosthesis obstructed the aortic valve with a peak transvalvar velocity of 2 m/sec and aortic regurgitation. Another patient with endocarditis demonstrated mitral stenosis as did two patients with left atrial myxomata. Tricuspid stenosis was demonstrated in three patients with right ventricular intracardiac masses (primary and secondary tumour and thrombus). By Doppler, the mitral and tricuspid stenosis was similar to from that seen in rheumatic heart disease with increased peak transvalvar velocity and prolonged pressure half-time. Because of the hazards associated with cardiac catheterisation in intracardiac masses, we conclude that Doppler ultrasound allows for the adequate assessment of the haemodynamic alterations so as to complement the images obtained by cross-sectional echocardiography.

Adult↗
PubMed1988

Unusual presentation of endomyocardial fibrosis.

A case of endomyocardial fibrosis in a Greek patient who had not visited the tropics is described. The patient suffered from an unusual form of the disease in that it was aggressive and recurrent (requiring three operative procedures) and presented with tricuspid stenosis, leading to syncope.

Adult↗
PubMed1987

Dyspepsia. The broad etiologic spectrum.

Dyspepsia remains one of mankind's most common afflictions. It affects virtually everybody at one time or another, it is responsible for the hundreds of millions of dollars spent each year on antacids and H2 antagonists, and it ranks second only to the common cold as a cause of loss of time from work. The condition denotes widely different things to different people, but by definition, complaints of dyspepsia must bear some relation to food or drink. (The term "dyspepsia" derives from dys, meaning "bad," and pepsis, meaning "digestion.") A physician writing in the Lancet more than a hundred years ago referred to dyspepsia as "the remorse of a guilty stomach." Unfortunately, the problem often turns out to be more serious than the transient pangs emanating from overindulgence. "Dyspepsy," De Quincey wrote in 1823, "is the ruin of most things: empires, expeditions, and everything else." That may be an overstatement. Still, dyspepsia can certainly be the harbinger of disastrous illness, as the following case illustrates.

Duodenal Ulcer↗
PubMed1987

Acquired abnormalities of the tricuspid valve--an ultrasonographic study.

In a retrospective ultrasonographic study, 32 cases of acquired disease of the tricuspid valve were detected amongst 7000 consecutive patients. Patients with congenital heart disease (except when the seat of an acquired disease) and with prosthetic heart valves, were excluded. There were twenty-one cases of rheumatic disease, all having additional involvement of the mitral valve. Prolapse (5 patients), bacterial endocarditis (2 patients), rupture of papillary muscle (1 patient), cardiac tumours (2 patients) and carcinoid heart disease (1 patient) were also identified. Acquired disease of the tricuspid valve is infrequently encountered during routine cross-sectional echocardiography but its recognition is clinically important.

Adult↗
PubMed1987

The plain chest X-ray in acquired heart disease in adults.

The chest X-ray is a cheap, easily repeatable and reproducible method of investigating the structure and function of the heart. While it is rarely of decisive diagnostic importance in the setting of modern methods of noninvasive investigation, it is valuable in evaluating the severity of cardiac pathology and also in revealing unsuspected abnormalities which may complicate management. For this reason all patients should have a chest X-ray, preferably both frontal and lateral, at the first attendance for cardiac evaluation. In most cardiac departments a routine frontal chest X-ray is taken at each outpatient appointment.

Adult↗