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Biomedical subjects

D Ross

Publications and source records attributed to D Ross.

At least 361 records · Page 20Linked to original sources
PubMed1979

Long-term results of pulmonary autograft for aortic valve replacement.

Eighty-five survivors who left hospital after pulmonary autograft replacement for severe aortic regurgitation have been followed critically. Five patients died in the first five years and 80 were followed for six to 11 years. Important aortic regurgitation occurred only early and was always related to technical malpositioning of one autograft cusp. Seven patients with fascial pulmonary valves had problems, requiring removal in four. There was a small (2%) morbidity from the right sided homograft and six were removed five to seven years later for progressive calcification; three of these had been irradiated. Despite a high incidence of trivial diastolic murmurs this valve replacement is still preferred for young patients without dilated aortic roots since the survivors remain well, with excellent, maintained relief of outflow obstruction, without problems from haemolysis and thromboembolism, and without deteriorating autograft function or need for anticoagulants. Histology of five autografts examined up to seven years after operation has shown normal living architecture.

Adolescent↗
PubMed1979

The effect of fluphenazine upon social and vocational functioning in remitted schizophrenics.

Thirty-six remitted schizophrenics who participated in an outpatient study of fluphenazine decanoate or oral fluphenazine vs placebo given for a year were examined for the effect of drug treatment upon social and vocational functioning. Only the period prior to any clinical relapse was evaluated. We found no difference between those on drug or placebo, and conclude that antipsychotic drugs, at least in the context of an aftercare clinic offering a rich spectrum of nonpharmacological services, and when combined with antiparkinson medication, do not interfere with social and vocational functioning.

Adult↗
PubMed1979

Extramedullary hematopoiesis in the liver in sudden infant death syndrome.

This study was undertaken to confirm or refute the findings of Naeye with regard to the pathologic continuation of extramedullary hematopoiesis in the livers of infants who die of the sudden infant death syndrome (SIDS). In general, our findings confirm his; however, although the data for SIDS do differ from those of controls, the differences are not statistically significant. Nevertheless, these results would seem to indicate the need for further investigation of the possibility of hypoxemia and/or anemia in affected infants.

Heart Defects, Congenital↗
PubMed1979

Ebstein's anomaly: late results of surgical correction.

Between 1969 and 1976, 10 severely disabled patients with Ebstein's anomaly were operated on at the National Heart Hospital using replacement of the tricuspid valve with mounted aortic homografts [9] or dura mater valve [1], plication of the atrialized right ventricle [10], and closure of an associated interatrail communication. 7 survivors have been followed up from 2 to 9 yr. 5 are asymptomatic. Symptomatic tricuspid regurgitation developed in 2 patients; from a paravalvar leak of the tricuspid homograft in one, and in the other calcification with stenosis in an irradiated homograft, 2.5 and 7.5 yr later. Permanent pacemakers were needed in 2 patients, 3 wk and 18 mth after surgery for symptomatic heart block. Despite corrective surgery for the structural abnormalities in Ebstein, late results remain influenced by disorders of rhythm and conduction disturbances, degenerative changes in the valves used for replacement and the intrinsic primary myocardial disease. Such "corrective" procedures in patients with Ebstein's anomaly can result in maintained symptomatic improvement but must be regarded as palliative surgery.

Adolescent↗
PubMed1978

Wire basket for immobilization of interscapular skin grafts.

One of the most difficult areas on the body to skin graft successfully is the interscapular and upper back region. We have used a wire "basket" to immobilize the interscapular region in 8 patients following wide excision for melanoma. "Takes" amounting to more than 90% in 7 patients and 80% in 1 patient have been obtained. The technique is simple and inexpensive.

Humans↗
PubMed1978

Electrophysiology of disopyramide in man.

The electrophysiological effects of an intravenous dose of disopyramide phosphate (2 mg per kg body weight) were studied in 17 patients. Studies were performed with the patients fasting, unpremedicated, and off all medication for three days. Blood samples for estimation of serum levels of disopyramide were collected in 15 of these patients. The effects of intravenous disopyramide were maximal at five minutes, less marked at 20 minutes, and largely gone by 30 minutes after administration of the drug. Sinus cycle length and corrected sinus node recovery time were shortened significantly. No index of atrioventricular nodal function was significantly changed. Both atrial and ventricular effective refractory periods were significantly prolonged. Further impairment of intraventricular conduction occurred in six patients with bundle branch block on electrocardiogram or prolonged HV interval. In one of two patients with Wolff-Parkinson-White syndrome, the bypass effective refractory period was prolonged. These electrophysiological changes are similar to quinidine and quinidine like drugs. It is recommended that disopyramide should be used cautiously in patients with evidence of His Purkinje system disease since it may lead to higher degrees of intraventricular block.

Adolescent↗
PubMed1978

Effect on survival after myocardial infarction of long-term treatment with phenytoin.

A prospective, randomised, open trial was performed in 150 patients to test for any beneficial effects on 2-year mortality of long-term antiarrhythmic therapy with phenytoin in patients with acute myocardial infarction. Patients were stratified according to age, sex, past history of myocardial infarction, and the presence of absence of electrical or mechanical complications in the course of acute infarction. They were then randomised to treatment or control groups (74 v. 76). The former received phenytoin in doses aimed at maintaining plasma phenytoin levels between 40 and 80 mumol/litre. All patients entered the study before discharge from the coronary care ward. Plasma phenytoin levels were in the therapeutic range in between 51 and 75 per cent of subjects at any follow up visit. There were 19 withdrawals from the treatment group, 10 of which were the result of side effects. There were 5 withdrawals from the control group. According to the original intention to treat, there were 18 deaths at 2 years in the treatment group and 14 deaths in the control group. There was no reduction in the incidence of instantaneous or sudden deaths. Deaths on treatment were not associated with a low phenytoin plasma level. Phenytoin treatment showed no beneficial effects on mortality and was associated with a high incidence of side effects.

Adult↗
PubMed1978

Cardioplegic solutions for myocardial preservation: analysis of hypothermic arrest, potassium arrest, and procaine arrest.

Separate effects of perfusion hypothermia, potassium arrest, and procaine arrest were studied in 150 hearts using the isolated rat heart preparation. Aortic flow rate (AFR), coronary flow rate (CFR), and heart rate (HR) were measured before and after ischemic periods of 90 to 300 min. Prior to the ischemic period, the aortic root was infused with Krebs-Henseleit buffer (KHB), buffer with 30 mEq KCl/L (KHB + K), or buffer with 0.2% procaine (KHB + P), at 15 degrees or 5 degrees C. During the ischemic period the hearts were maintained at 15 degrees or 5 degrees C in a hypothermic chamber. The three solutions had similar recoveries of AFR at 15 degrees and 5 degrees C following ischemic periods of 90, 180, and 240 min. The KHB + K and KHB + P had better recoveries of AFR than KHB at 5 degrees C and 300 min of ischemia. The KHB + K and KHB + P also caused more rapid arrest and a higher incidence of spontaneous recovery of sinus rhythm. Arrest at 5 degrees C was equal to or superior to arrest at 15 degrees C. Perfusion hypothermia is the main component of cold cardioplegia. The addition of procaine or potassium results in increased functional recovery at extended ischemic times at 5 degrees C, more rapid arrest, and better electrical recovery.

Animals↗
PubMed1978

Complex pulmonary atresia with congenital systemic collaterals. Classification and management.

80 patients with pulmonary atresia and subaortic ventricular septal defect had complete angiography with right ventricular, aortic and selective arterial angiograms to delineate the anatomy of the central pulmonary arteries and the systemic supply to the lungs, as correct management of the patient depends on this. In 67 (85 p. 100) there were 1-5 large congenital systemic collateral arteries mainly arising at or below the aortic isthmus. This group, referred to as "complex pulmonary atresia" with right aortic arch in 30, had variable central pulmonary artery development, either completely absent in 17, hypoplastic in 33 (49 p. 100) appearing as a "seagull" (une mouette) in the mediastinum on late films or large well developed vessels in 17. Patients with hypoplastic central arteries require special management. We now perform a two stage procedure, initially placing a conduit containing a homograft aortic valve between the right ventricle and small central pulmonary arteries in order to develop them and leaving the ventricular septal defect open. Initial results in 6 patients treated this way are encouraging and it is proposed to close the defect later after enlargment of the pulmonary arteries has occurred.

Adolescent↗
PubMed1978

On the proper use of the Soret band for hemoglobin detection in erythrocytic cells.

Intracellular hemoglobin detection by light microscopy in the Soret band (414nm) is a sensitive means of correlating morphology and biochemical function in studies of erythrpoiesis. Correct application of the technique requires a light source with strong emission in the near ultra-violet, a filter with a pass-band at 414nm, a preparation of living cells or an unfixed smear, and a receiver that is sensitive to the Soret wavelength. The human eye is very insensitive to light at 414nm and quite sensitive to stray green light: it is consequently much inferior to a black and white television or camera film for viewing a Soret image. The appearance of hemoglobin during maturation of erythroid cells in human bone marrow can be detected with greater sensitivity by this method than by a peroxidase-benzidine stain and it is the only method applicable to living cells.

Animals↗
PubMed1977

Supravalvular mitral stenosis associated with ventricular septal defect.

We describe three patients with supravalvular mitral stenosis caused by a diaphragm located just above the mitral valve and associated with a ventricular septal defect. Two of our three patients also had an associated coarctation of the aorta. The physical signs, ECGs, chest roentgenograms, and cardiac catheterization data are described. Points helpful in the differential diagnosis of this malformation are emphasized. All three patients were treated successfully by surgery.

Adolescent↗
PubMed1977

Thyroid hormone levels and protein binding in patients on long-term diphenylhydantoin treatment.

The effect of long-term diphenylhydantoin (DPH) treatment on thyroid hormone concentrations and protein binding was determined in a randomized controlled trial. As has been demonstrated previously, total thyroxine (T4) concentrations were significantly depressed in patients on DPH. There was no significant effect on indirect indices of protein binding of thyroid hormones, and the free thyroxine index (FTI) was also significantly depressed. Triiodothyronine (T3) and thyrotrophin (TSH) concentrations were either unaffected, or only very slightly affected by DPH. Significant effects on the FTI were still apparent 4 weeks after discontinuing treatment. It is concluded that the depression of total T4 levels observed in vivo is not due solely to diminished protein binding, but may instead be largely explained by reports suggesting enhanced degradation of T4 following DPH therapy.

Adult↗