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Biomedical subjects

A Stewart

Publications and source records attributed to A Stewart.

At least 307 records · Page 17Linked to original sources
PubMed1984

Pyridine nucleotides in normal and cataractous human lenses.

The levels of NAD+, NADH, NADP+ and NADPH have been determined in each cortex and nucleus of about 80 normal and cataractous human lenses and in a small number of calf, rabbit and rat lenses. Cataractous lenses had lower levels of all nucleotides than the normal lenses but no progressive decreases were associated with the development of nuclear colour, or with cortical, diabetic, traumatic and steroid cataracts. It was concluded that a lack of reduced pyridine nucleotides was not responsible for a decrease in the ability of the lens to protect itself against oxidative damage.

Aged↗
PubMed1984

Trends in coronary heart disease event rates in New Zealand.

To examine the reasons for the recent decline in coronary heart disease death rates in New Zealand, a register of definite myocardial infarction and sudden death was established in the Auckland region (1981 population 829,464). Both routine and nonroutine case finding sources were used and event rates for the 12 months from March 1, 1981, were compared with estimates from an earlier study conducted in 1974. In 1981, 1,093 myocardial infarction and/or sudden death events in people 25-69 years of age were registered. The age standardized event rates for the total of myocardial infarction and sudden death were 506/100,000 and 139/100,000 for men and women, respectively. Over the seven-year period from 1974 there was no change in the event rate or 28-day case fatality of definite myocardial infarction, but a significant decline in the rate of sudden death occurred from 139/100,000 to 117/100,000. The decline in the sudden death rate was particularly marked in people under the age of 50 years and in subjects with a prior history of myocardial infarction.

Adult↗
PubMed1984

HLA in two islands of French Polynesia.

The HLA-A, B, and C antigens of 243 individuals from two Polynesian islands, Maiao and Hiva Oa, have been characterized. 328 haplotypes were defined by family analysis. Most frequent antigens were A2, A11, Aw24, A26 , Aw34 ; Bw38, Bw39 , Bw48 , Bw55 , Bw56 , Bw60 ; Cwl, Cw3, and Cw4. Several other antigens were present at low frequency or were present on only one island. New variants of Bw22 and B40 were found. Despite an overall similarity in antigens of the two islands, the combination of HLA-A, B and C antigens on the haplotype were distinctive. Of 328 total haplotypes identified, 65 were unique. Thirteen of these (20%) were present on both islands. Twenty-eight (43%) were unique to Hiva Oa and 24 (37%) were unique to Maiao . Significant, positive linkage disequilibrium values (delta) for HLA-A, B and HLA-B, C antigens were also different for the two populations.

Alleles↗
PubMed1984

Mini-mental state examination in neurological patients.

The Mini-Mental State examination has been found to be a quick and valuable test for simple bedside screening, and for serial assessment of cognitive function in a population of 126 neurological patients. Amongst those with cognitive impairment, there was a close relation between the Mini-Mental State examination and the conventional Weschler Adult Intelligence Scale (WAIS). However, the Mini-Mental test was not a sensitive indicator of focal versus diffuse hemisphere disease. Further refinement in the areas of language and visuo-spatial function may improve its value.

Adolescent↗
PubMed1983

Assessment of a geriatric exercise programme using ambulatory electrocardiography.

The purpose of this study was to assess the efficacy as well as the immediate possible cardiovascular risk of a geriatric exercise programme, administered without prior medical screening or evaluation of the exercise capacity of the participants, in improving cardiorespiratory fitness. Ambulatory electrocardiography performed during exercise on 6 randomly selected male participants in a physiotherapist-controlled geriatric exercise programme revealed heart rates of 72-97/min, values unlikely to produce significant improvements in cardiorespiratory fitness. This low-intensity exercise session did not induce any ischaemic ST-segment displacements, or arrhythmias displaying the generally accepted criteria for premonitory arrhythmias known to precede the development of ventricular fibrillation. However, subsequent stress testing, performed at the lower threshold intensity of exercise needed to elicit a significant physiological training effect, resulted in an adverse cardiac response in 3 subjects, of whom 2 were asymptomatic. We conclude that the geriatric exercise programme under investigation would be unlikely to result in improved cardiorespiratory fitness in the majority of participants, but if such a programme is to be implemented in a safe manner in a geriatric population, prior medical screening including exercise testing is mandatory.

Aged↗
PubMed1983

The longevity of international rugby players.

The longevity of New Zealand international rugby players (All Blacks) is compared with the New Zealand male population to test the hypothesis that vigorous leisure time physical activity in the form of rugby in early adulthood is associated with an increased longevity. Data on 822 All Blacks since 1884 are compared with information from New Zealand life tables for males. The life expectancy of All Blacks is the same as the general population although non-Maori All Blacks live almost ten years longer than Maori All Blacks.

Adolescent↗
PubMed1983

Hormone and metabolite profiles in alcoholic liver disease.

Circulating hormone and metabolite profiles have been studied in ten patients with alcoholic cirrhosis, five patients with alcoholic hepatitis and/or fatty liver, and nine normal controls over a 12-h period of meals and activity. Blood glucose was elevated throughout the day in both cirrhotic and non-cirrhotic alcoholics (mean 12-h glucose; controls 5.38 +/- 0.16 (SEM) mmol/l; cirrhotics 6.98 +/- 0.30 mmol/l, P less than 0.001; non-cirrhotics 7.18 +/- 0.26 mmol/l, P less than 0.001). Non-cirrhotic alcoholics had an exaggerated insulin response to meals, whereas cirrhotic patients had hyperinsulinaemia throughout the day (mean 12-h insulin; controls 16.3 +/- 2.3 mU/l; cirrhotics 35.8 +/- 6.6 mU/l, P less than 0.02). Growth hormone levels were elevated only in patients with cirrhosis (mean 12-h growth hormone, 7.06 +/- 1.35 v. 0.85 +/- 0.17 micrograms/l, P less than 0.001). Serum cortisol was persistently elevated in cirrhotics but only in the evening in non-cirrhotic alcoholics. Lactate and pyruvate responses to meals were exaggerated in non-cirrhotic patients whereas in cirrhotics, levels were persistently raised. Blood glycerol was elevated in all alcoholic patients whereas ketone body levels were normal. Hypertriglyceridaemia was observed only in non-cirrhotic patients. No relationship between the endocrine and metabolic state was observed in either cirrhotic or non-cirrhotic patients.

Adult↗
PubMed1983

Language development in a group of very low-birth-weight children whose postauricular myogenic response was tested in infancy.

A new instrument for the detection of the postauricular myogenic (PAM) response was used to test the hearing of 106 infants weighing less than or equal to 1,500 g when they were aged 1 to 21 months. Eighty-eight infants showed a positive response at 60 dB hearing level (HL) (normal). The other 18 did not respond; four were found to have sensory neural hearing loss and another six had conductive loss due to secretory otitis media. Of the 106 children, 90 aged 2 years or more (mean 27 months) were living in the United Kingdom, and their language development was assessed. It was normal in 67/75 children whose PAM response had been normal in infancy. The remaining eight children with normal PAM responses in infancy, had language delay. All eight children had problems that were thought to account for the delay, including three with mental retardation, three with cerebral palsy, and two whose families did not speak English. Language development was normal in 11/15 children tested whose PAM responses had been found to be abnormal, including all six whose secretory otitis media had been diagnosed and treated at the time of the PAM test. Delay in language development was found in 3/4 children with sensory neural hearing loss who were available for testing and in one child with overall developmental delay. It is concluded that a positive PAM response at 60 dB HL in infancy indicated hearing adequate for the development of normal speech in otherwise normal children among a group of infants at high risk of hearing loss.

Child, Preschool↗
PubMed1982

The distribution and arrangement of elastic fibres in the intervertebral disc of the adult human.

Selected cervical and thoracic intervertebral discs were removed from twelve human adults at autopsy. The discs were prepared by the paraffin method, stained with orcein or by Verhoff's technique and examined with the light microscope for the presence of elastic fibres. Elastic fibres were located only in the lamellae of the anulus fibrosus and the superficial zones of the nucleus pulposus from regions of intervertebral disc that connected or interfaced with osseous vertebrae. Elastic fibres were longitudinally, circularly and obliquely arranged in lamellae of the anulus fibrosus and penetrated bony vertebrae as Sharpey's fibres. Elastic fibres assumed a three dimensional lattice work in the superficial zone of the nucleus pulposus and connected it to the hyaline cartilage end plate as Sharpey's fibres. Irregularly arranged elastic fibres interconnected the superficial zone of the nucleus pulposus and lamellae of the anulus fibrosus. Elastic fibres were a major histological component of the ligamenta flava and anterior longitudinal ligaments.

Aged↗
PubMed1981

Kinetics of reduction of the primary donor of photosystem II. Influence of pH in various preparations.

The kinetics of reduction of P-680, oxidized by a flash, have been measured with chloroplasts treated with Tris, hydroxylamine or cholate, with PS-II particles from Phormidium (Tris-treated) and with subchloroplast particles prepared with digitonin or Triton. In all cases the electron transfer from D1 to P-680+ has similar rates, influenced similarly by pH and D1 has a one-electron capacity.

Chlorophyll↗