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Biomedical subjects

J Pearn

Publications and source records attributed to J Pearn.

At least 109 records · Page 6Linked to original sources
PubMed1982

A total population study of diagnosed chromosome abnormalities in Queensland, Australia.

Aneuploidy and structural chromosome rearrangements comprise a significant group of abnormalities in the general population. The true incidence of such abnormalities can be obtained by large research studies of consecutive newborns. In practice, the observed incidence of such chromosome abnormalities is obtained by karyotyping subjects who present for clinical reasons. The difference between the observed clinically indicated rates and the assumed rate (by comparison with data from consecutive newborn studies) would allow the estimation of the unrecognised chromosome abnormality load in the general population. The difference between these two rates would provide valuable data concerning the appropriateness of selection techniques for routine chromosome analysis. This paper reports such a study, from Queensland, Australia. A total population 5-year survey (1976-1980) of the diagnosed chromosome abnormalities in this unselected primary population of 2.2 million people is reported. Five hundred and eighty-nine chromosome abnormalities were detected in a consecutive series of 6092 karyotypes performed (9.7%). This figure is significantly lower than that found in most other reported series where case selection for karyotyping is determined by clinical criteria. In this current study the annual diagnostic rate for chromosome abnormalities was 5.41 per 100,000 of the general population. Cumulative frequency histograms for all types of chromosome abnormality, by age, are presented. In current practice, 32% of chromosome abnormalities are not diagnosed until adult life. Fifty percent of cases of chromosome abnormality (of all types) remain undiagnosed by the age of 1 year, in spite of a relatively liberal acceptance rate on the part of laboratories offering routine karyotyping services. It is concluded that a positive diagnostic rate greater than 10%, in routine chromosome laboratories, probably indicates that more than half the true cases of chromosome abnormality in a population are being missed.

Adolescent↗
PubMed1981

Corked up: clinical hyoscine poisoning with alkaloids of the native corkwood, Duboisia.

Australian native trees of the genus Duboisia contain high concentrations of atropine-like alkaloids, especially hyoscine. Occupational exposure to the dried plant material results in two clinical syndromes: "cork-eye", and being "corked up". Plant abuse, as an intoxicant and hallucinogen, also results in the "corked up" syndrome. This paper presents four cases of the Duboisia syndrome. Central effects and peripheral anticholinergic effects are encountered in both occupational and accidental field exposure. The particular susceptibility of children, and management of the Duboisia poisoning syndrome are discussed.

Adolescent↗
PubMed1981

First-aid for snake-bite: efficacy of a constrictive bandage with limb immobilization in the management of human envenomation.

A herpetologist was bitten on the thumb by a common brown snake (Pseudonaja textilis). A constrictive bandage to impede lymphatic and capillary flow was applied, and the upper limb was immobilized. Two hours after the bite, there were no signs of symptoms of envenomation and venom (to a sensitivity of 0.5 ng/mL) was undetectable in serum and urine. Within five minutes of removal of the constrictive bandage, significant signs of envenomation developed, and serum and urine levels of venom rose significantly. The patient received two ampoules of brown-snake antivenom, and had recovered within six hours. No anaphylaxis of other allergic phenomena occurred, despite the fact that three other doses of antivenom had been administered in the preceding 36 months for prior elapid envenomation. By means of an experimental whole-mouse technique, and an enzyme-linked immunospecific assay (ELISA) system, the snake involved was shown to deliver 4.91 mg of venom in an average bite. A constrictive bandage properly applied to impede lymphatic and capillary flow, together with limb immobilization, is effective in the field management of human elapid envenomation.

Animals↗
PubMed1980

How long does it take to become fit?

To become fit an individual must generate optimal muscle strength and must develop cardiopulmonary reserve, or stamina. Physical fitness programmes require motivation, a graded series of appropriately designed exercises, and scientific surveillance. Motivation and efficiency in fitness programmes depends on early positive feedback to participants, confirming that stamina and strength are developing. A practical field experiment was performed to determine the minimum time that healthy young adults require to reach an initial plateau in objective measures of fitness. Fifty male university undergraduates were studied during an annual volunteer military training camp. Thirty had volunteered to take part in the fitness programme; the remaining 20 had initially rejected the offer but underwent the programme as part of their military training and acted as unmotivated controls. All the subjects became fit within 14 days of starting training, with objective improvement in both absolute strength and pulse recovery times. Non-motivated individuals, training with motivated individuals for 20 minutes each day, can therefore achieve levels of fitness indistinguishable from those of healthy highly motivated subjects. Fitness programmes must be carefully supervised, however, with medical examinations for those about to undergo vigorous exercise.

Adolescent↗
PubMed1980

Will fenced pools save lives? A 10-year study from Mulgrave Shire, Queensland.

No community has measured baseline child-drowning rates, introduced protective safety legislation, and then assessed its effectiveness. One unique community in Northern Australia, Mulgrave Shire, has implemented rigidly-policed pool safety legislation since 1960; a study of the child drowning profiles therein is reported here to given an estimate of the efficacy of safety legislation. No child has drowned in a fenced pool either in Cairns or in Mulgrave Shires over the 10-year period of the survey. For Mulgrave Shire, no child has drowned during 9200 pool-years. Comparative studies of two neighbouring Shires, with different safety legislation policies (both in absolute safety regulations, and the spirit with which they are prosecuted), indicate that fatal and near-fatal pool accidents can be cut by at least half if safety legislation is effective. Special dangers apply to pools in caravan parks and multiunit dwellings.

Accident Prevention↗
PubMed1980

Norms for the social class distribution: reference data for epidemiological and health studies.

The influence of social class and socioeconomic status on health risk is enormous. To interpret apparent clustering of disease and accident patterns in the community, quantitative estimates of the normal socioeconomic profile are required. This study provides such reference data for epidemiology and health studies. Three Australian scales of social stratafication have been used--Congalton's four-point and seven-point scales, and the six-point scale of Broom-Jones-Zubrzycki. Population norms for socio-occupational ranking, by sex, are presented both as frequency distribution histograms and as reference tables. The use of such tables in health studies is discussed with relevance to public health campaigns (for example, antismoking campaigns), and to the investigation of disease patterns within society.

Australia↗