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Biomedical subjects

R McDonald

Publications and source records attributed to R McDonald.

At least 109 records · Page 6Linked to original sources
PubMed1977

Oral and intravenous propranolol during exercise.

The intrinsic sinoatrial (SA) rate at rest and during exercise was measured in 5 normal male subjects after prolonged oral and acute intravenous administration of propranolol and atropine. At rest, the intrinsic SA rate was similar after both oral and intravenous propranolol. At the higher levels of power output on a cycle ergometer, cardiac rate was slower after oral than after intravenous propranolol. When the intravenous study was repeated with the use of an additional dose of propranolol, cardiac rate was lower at comparable levels of power output, but not as low as that after oral propanolol. Differences in responses were interpreted as reflecting varying degrees of beta blockade, the most complete being that after prolonged oral propranolol administration of 320 mg daily. The intravenous dose of propranolol usually used to obtain the "pharmacologically isolated heart" at rest is too small to induce full beta blockade in exercise.

Administration, Oral↗
PubMed1977

Social skills training of out-patient groups. A controlled study of rehearsal and homework.

Fifty-one out-patients with social skills deficits (two-thirds men) completed ten weekly sessions of 75-minute group treatment; 44 were followed up for a mean of 16 months. Random assignment was to one of three conditions: (I) Cohesive group discussion; (2) Modelling and role-rehearsal; or (3) Modelling and role-rehearsal + daily social homework. All three treatment conditions produced significant but incomplete improvement at the end of treatment and follow-up. The two role-rehearsal conditions were significantly superior to group discussion on several measures. Patients who completed daily social homework assignments did significantly better than patients who completed control homework. Alcohol and drug abuse patients usually dropped out. Schizophrenic patients in remission had lost their improvement at follow-up. Patients with other diagnoses retained their gains to 16-month follow-up.

Ambulatory Care↗
PubMed1976

Characteristics of three strains of feline fibrosarcoma virus grown in cat and marmoset monkey cells.

Two strains of feline fibrosarcoma virus (ST-FeSV and GA-FeSV) were found to induce tumors in cats and marmosets, and to transform feline and marmoset cells in vitro after primary inoculation. A third strain (SM-FeSV) failed to induce tumors or transform marmoset cells after primary inoculation; however, when SM-FeSV-injected marmoset cultures were passed 26 times in vitro, the cell cultures released infectious virus which transformed marmoset fibroblasts but still failed to induce tumors in marmosets. ST-FeSV induced mainly round-cell type transformation (r foci), GA-FeSV induced predominantly mixed round-fusiform cell type transformation (fr foci), and SM-FeSV induced r and fr type foci with a higher proportion of fusiform cells in the fr foci than seen with GA-FeSV. Transforming virus was obtained from r or mixed r/fr foci of ST-FeSV but not from fr foci; heat treatment changed the virus from producing almost exclusively r type foci to inducing an increased number of fr foci. Passage of FeSV in cat cells yielded viruses with a higher ratio of infectivity for feline vs marmoset cells, while passage of FeSV in marmoset cells yielded virus with a relatively higher infectivity ratio for marmoset cells; the three strains differed in the degree of change in the infectivity ratio. Despite the alteration of host range of SM-FeSV propagated in marmoset fibroblasts, the virus retained feline P-30 antigen by CF and FA assays. Neutralization tests did not indicate but also did not exclude an alteration of the surface antigens of ST-FeSV or SM-FeSV propagated in marmoset fibroblasts. The alteration of the relative infectivity of FeSV during passage in marmoset cells may be due to: (1) the selection of a variant present in the original heterogenous uncloned population; (2) mutation; or (3) recombination with some marmoset genetic material, possibly an as yet unidentified endogenous marmoset virus.

Animals↗
PubMed1975

Subacute sclerosing panencephalitis in Southern Africa.

A first attempt to gather the available information on subacute sclerosing panencephalitis (SSPE) in Southern Africa has produced records of 79 cases which have occurred since 1955. An important feature of the epidemiology is the clustering of 48 cases in the 5-year period 1970-1974. Thirty of these patients were resident in the Cape Province, and most of them were from the Coloured community. An SSPE registry will be maintained at the MRC Virus Research Unit of the University of Cape Town and an appeal is made to all practitioners to contribute any relevant data on patients with this disease.

Adolescent↗