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Biomedical subjects

K Ball

Publications and source records attributed to K Ball.

16 recordsLinked to original sources

Concentrations of immunoreactive inhibin in ovarian and peripheral venous plasma and follicular fluid of Booroola ewes that are homozygous carriers or non-carriers of the FecB gene.

No gene-specific differences were found during either the luteal or follicular phases of the oestrous cycle in the venous secretion rates of ovaries or in concentrations of immunoreactive inhibin in peripheral plasma between Booroola ewes that were homozygous carriers (BB) or non-carriers (++) of the FecB gene. In three experiments in which concentrations of plasma inhibin and follicle-stimulating hormone (FSH) were compared, gene-specific differences were noted for FSH (P less than 0.05), but no significant correlations were noted between FSH and inhibin for either genotype. Granulosa cells and follicular fluid, but not theca interna, stroma or corpora lutea, were the major intra-ovarian sites of inhibin; no gene-specific differences were noted for inhibin concentrations in follicular fluid or in any of the intra-ovarian tissues. The mean concentrations of inhibin in follicular fluid remained constant irrespective of follicular diameter whereas the mean total contents of inhibin increased significantly with increasing diameter (P less than 0.05). Inhibin secretion rates were four times higher in ovaries with oestrogen-enriched follicles (i.e. greater than or equal to 50 ng oestradiol ml-1) than in ovaries with no such follicles (P less than 0.01). Moreover, inhibin concentrations were higher in follicular fluid of oestrogen-enriched follicles than in those with low oestrogen (i.e. less than 50 ng ml-1; P less than 0.05). Ovariectomy resulted in a significant reduction in concentrations of immunoreactive inhibin from plasma (P less than 0.01). The residual plasma inhibin in some Booroola ewes was not associated with genotype. It is concluded that, although antral follicles are a major source of inhibin in Booroola ewes, immunoreactive inhibin is not associated with the FecB gene and is not responsible for the gene-specific differences in concentrations of FSH in plasma.

Analysis of Variance

Conducting laser research.

Nurses today are sometimes reluctant to get involved with research due to their lack of involvement or experience. This article simplifies the research process by comparing its steps with the familiar steps of the nursing process. Laser technology offers nurses the challenge of an ever-changing arena in which research projects can be easily identified and conducted.

Humans

Children's understanding of monosyllabic nouns in quiet and in noise.

A four-alternative, forced choice adaptive procedure was used to measure the lowest intensity at which children could identify monosyllabic nouns that had been standardized to be understandable (at comfortable listening levels) to inner city, 3-year-old children. Results showed no age-related performance changes when the words were presented against a 12-talker babble or against filtered noise. In quit, however, performance improved between the ages of 5 and 10 years. Performance of children with learning problems was poorer than performance of children achieving normal school progress, even though clinical measures of auditory sensitivity showed no differences. Results are discussed in terms of "semantic closure" skills of children.

Adult

Mental set alters visibility of moving targets.

An observer's knowledge of a moving target's direction and velocity enhances detectability. In addition, knowledge of direction and velocity speeds an observer's reaction to the motion of a previously stationary target. Since rival, nonperceptual hypotheses can be ruled out, these effects represent a direct modulation of vision by mental set.

Cognition

The cardiologist's responsibility for preventing coronary heart disease.

The recent increase in coronary heart disease is real and the causes must mainly be environmental. Consequently the condition should largely be preventable. The application of what is already known is likely to be a far more effective way of reducing the mortality rate than all attempts at palliative treatment, but vigorous action will be necessary. Much greater sums are being expended on coronary-care units and cardiac surgery than in preventing the need for them, although there is little evidence that they have significantly lowered the over-all mortality rate. Conventional treatment is immensely expensive. Prevention could in the long run be much cheaper. Cardiologists on their own are unlikely to succeed in a program of prevention. They need the help of many others, including community nurses, nutritionists, public health workers, sociologists, and of course general practitioners, but they have responsibility for leadership and for providing background knowledge. For the detection of certain risk factors, health examinations are necessary and should be part of general practice. Also, advice is best given on an individual basis. The chief-known risk factors (hyperlipidemia, hypertension, smoking, physical inactivity) could be controlled. CHD occurs in adults but atherosclerosis starts many years before. Prevention should begin with appropriate infant feeding, whenever possible with breast milk, and continue into childhood, when habits are formed and attitudes to life can best be influenced. It should be possible to bring up children virtually free from risk factors. It may never be possible to prove the effectiveness of such a multifactorial program by prospective controlled intervention studies, but the evidence indicates strong probability. The stakes are too high to delay action any longer. Physicians daily give advice in areas where the evidence is much less certain. Such a program for the control of coronary artery disease is urgently needed and could become one of the most rewarding activities for the medical profession.

Adult