Search PubMed⌕ Search

Biomedical subjects

M Johnstone

Publications and source records attributed to M Johnstone.

At least 37 records · Page 2Linked to original sources
PubMed1983

Urban squatting and migration in Peninsular Malaysia.

"This article examines some of the links between the phenomena of urban migration and squatter settlements in the Third World city. This will be done by demonstrating that both are outcomes of fundamental social and political forces that have operated on these societies. Migration and squatting are placed in a context of the historical processes that led to the uneven development of Malaysia. The article offers some explanation for the origin of the inequalities observed in spatial structures--in this case urban housing--by focusing on one of the contributory factors, namely migration."

Asia↗
PubMed1981

A randomized trial to assess childhood circumcision with the Plastibell device compared to a conventional dissection technique.

A randomized trial of routine circumcision in children using the Plastibell device is described and compared to a dissection suturing technique. One hundred children were studied with a mean age of 4.7 years. The device was applicable to all boys up to the age of 8, and a few older. General discomfort was carefully assessed and slightly less common after plastibell circumcision, but dysuria more so. No serious complication was encountered with either method; infection was slightly more common after the conventional procedure. Cosmetic results were similar for both methods. It is concluded that the Plastibell device is a satisfactory method for circumcising children of this age.

Child↗
PubMed1980

Concentration-dependent morphologic effects of cytochalasin B in the aqueous outflow system.

Cytochalasin B at concentrations of 1, 5, 10, 15, 20, or 40 microgram/ml was continuously exchange-perfused into the eyes of nine living Macaca mulatta monkeys while intraocular pressure (IOP) was maintained at 25 mm Hg for 30 min. Pressures were then slowly reduced to 4 mm Hg to permit blood to reflux into Schlemm's canal as a tracer, and the eyes were fixed while maintained at 4 mm Hg IOP. Tissues were examined in all eyes by light and transmission electron microscopy. At concentrations of 1, 5, and 10 microgram/ml cytochalasin B, the integrity of the endothelial lining of the trabecular wall of Schlemm's canal was maintained. At 15 microgram/ml cytochalasin B, 6% of the length of the endothelial lining was disrupted; at 20 microgram/ml, 54%; and at 40 microgram/ml, 83%. There was a washout of extracellular material at the site of breaks and also a reflux of blood from Schlemm's canal into the trabecular meshwork in the same regions.

Animals↗
PubMed1979

High-dose fentanyl.

Explore the source record for details and available documents.

Anesthesia, Intravenous↗
PubMed1978

Halothane hepatitis.

Explore the source record for details and available documents.

Chemical and Drug Induced Liver Injury↗
PubMed1976

"Vasovagal" syncope.

Explore the source record for details and available documents.

Cardiovascular System↗
PubMed1976

The effect of lorazepam on the vasoconstriction of fear.

Volume-pulse digital plethysmography performed under ideal conditions on relatively fit adults has shown that lorazepam 4 mg intravenously abolishes the vasoconstriction of fear and restores the digital vasodilatation of the tranquil mind. The sedative effect of the drug is prolonged and is associated with several hours of anterograde amnesia from the time of its administration. The drug has no effect on the vasoconstrictor reaction to cold, pain, noise or other forms of adrenergic stimuli. Lorazepam seems to modify or prevent the psychomotor reactions which may complicate ketamine anaesthesia.

Adult↗
PubMed1976

The cardiovascular effects of ketamine in man.

The arterial hypertension of ketamine is prevented by verapamil, a calcium ion antagonist. This indicates that ketamine is a direct myocardial stimulant acting by increasing the availability of calcium across the cell membranes of the myocardial and the Purkinjé systems. The positive chronotropic action of ketamine is not reversed by verapamil. Both the chronotropic and the inotropic effects of ketamine are prevented by halothane which acts partly by increased vagal tone and partly by what appears to be a verapamil-like depression of calcium availability. Ketamine blocks the reflex sympathetic response of the peripheral blood vessels to surgical stimuli. The site of the block within the sympathetic reflex arc has not been identified. It is not at the alpha adrenoceptor level. The clinical implications of the findings have been discussed.

Adult↗