Biomedical subjects

C de Wytt

Publications and source records attributed to C de Wytt.

5 recordsLinked to original sources

PubMed1989

The contribution of mortality statistics to the study of multiple sclerosis in Australia.

Mortality statistics provided a valuable source of support for data obtained from prevalence surveys of multiple sclerosis in Australia. Firstly, multiple sclerosis mortality data for the decade 1971-80 in the States of Australia confirmed the relationship between increasing disease frequency and increasing south latitude shown by State and regional point prevalence surveys based on the national census day 30 June 1981. Secondly, a comparison with mortality data from the decade 1950-59 showed that in most States there had been a substantial fall in multiple sclerosis mortality in the more recent decade and this was clearly an important contributing factor to the rise in prevalence noted between the morbidity surveys of 1961 and 1981. Thirdly, multiple sclerosis mortality in the UK-born migrant population dying in Australia was found to be similar to that of the Australian-born population and very much lower than that found in the UK. This observation corroborated evidence from the 1981 morbidity surveys and suggested that migration from the UK to Australia may lower the risk of developing multiple sclerosis either through a reduction in disease incidence or the operation of environmental factors curbing disease expression.

Australia↗

PubMed1988

The clinical profile of MS in Australia: a comparison between medium- and high-frequency prevalence zones.

Recent epidemiologic studies of multiple sclerosis (MS) in Australia defined the State of Queensland as a medium-frequency zone and the more southerly placed cities of Perth, Newcastle, and Hobart as high-frequency zones. Clinical profiles in the patient populations of both frequency zones were remarkably similar in most respects to each other and to MS populations in the northern hemisphere. However, male patients in Queensland differed from their counterparts in the three cities by showing a greater tendency to develop a progressive disease course and, hence, more disability. The explanation for these observations is uncertain; we speculate that the hotter climate in Queensland may be relevant.

Adult↗

PubMed1987

The epidemiology of multiple sclerosis in Queensland, Australia.

An epidemiological survey of multiple sclerosis (MS) in the State of Queensland was undertaken with its prevalence day being the national census day on June 30th, 1981, 20 years after a regional survey within the State. The relationship between increasing prevalence of MS and increasing south latitude within the State of Queensland which was suggested by the 1961 study was confirmed in the present study. The prevalence rate had increased significantly over the 20-year period between the studies but the State remained a medium frequency zone for MS (prevalence rate between 5 and 29 per 100,000 of population). Although a real increase in disease frequency could not be excluded as a contributing factor to the rise in prevalence, it was most likely due predominantly to an increase in life expectancy amongst the MS population and also in differential migration of a population at a greater risk of developing MS than the indigenous population. The proportions of Australian-born patients who had migrated to Queensland from the higher risk southern regions of Australia or travelled overseas to countries known to be high-risk for MS prior to disease onset, had fallen between the two surveys thus exerting, if anything, a negative influence on the change in prevalence. Analysis of MS prevalence rates amongst migrant populations in Queensland as compared to the more southerly city of Perth in Western Australia, suggested that the risk of acquisition of MS may extend over a wider age range than is generally accepted. Finally, there was an absence of MS cases amongst the Aboriginal population in Queensland but it can only cautiously be concluded from this study that the disease is rare in these peoples.

Adolescent↗

PubMed1987

Lacunar infarction: a 12 month study.

Identification of lacunar infarction as a cause of stroke is important, as investigation, treatment and outcome differ from those in the other stroke categories. In this study of 121 acute strokes admitted over a period of 12 months, 28 patients (23%) were found to have lacunar infarction and 93% of patients with lacunes had either a past history of hypertension or echocardiographic evidence of left ventricular hypertrophy. The degree of left ventricular hypertrophy tended to be moderate to severe with an average left ventricular mass on echocardiography of 120 g/m2. Pure motor hemiparesis was the commonest clinical presentation and lacunar infarction overall has a low mortality.

Cerebral Infarction↗

PubMed1984

Bioavailability and pharmacokinetics of phenytoin during pregnancy.

Five epileptic women needing to commence phenytoin therapy during pregnancy received a single intravenous and a single oral dose of phenytoin several days apart before starting regular intake of the drug. Plasma phenytoin concentration - time data were analysed by three different pharmacokinetic techniques. However assessed, the mean oral bioavailability of the drug proved to be about 90% of the intravenous bioavailability. This finding makes it unlikely that impaired bioavailability accounts for the increase in oral phenytoin dosage necessary in pregnancy to maintain plasma phenytoin concentrations at pre-pregnancy values. Phenytoin clearance in the pregnant subjects was approximately double the published values for phenytoin clearance in non-pregnant persons. This suggests that increased (metabolic) clearance accounts for the increased phenytoin dosage requirement of pregnancy.

Aging↗