151
|
Stephenson DG, Stewart AW, Wilson GJ. Dissociation of force from myofibrillar MgATPase and stiffness at short sarcomere lengths in rat and toad skeletal muscle. J Physiol 1989; 410:351-66. [PMID: 2529371 PMCID: PMC1190483 DOI: 10.1113/jphysiol.1989.sp017537] [Citation(s) in RCA: 80] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
1. Single fast-twitch fibres from the extensor digitorum longus muscle of the rat, Rattus norvegicus, and single twitch fibres from the iliofibularis muscle of the cane toad, Bufo marinus, were mechanically skinned and then used to measure maximally Ca2+-activated [( Ca2+] greater than 0.03 mmol l-1) isometric force production, myofibrillar MgATPase activity and fibre stiffness at different sarcomere lengths. MgATP hydrolysis was linked by an enzyme cascade to the oxidation of NADH (nicotinamide adenine dinucleotide, reduced form) and was monitored by a microfluorimetric system. Fibre stiffness was measured from the amplitude of force oscillations generated by small sinusoidal length changes. 2. At sarcomere lengths which were optimal for isometric force production (around 2.7 microns for rat and 2.2 microns for toad fibres) the myofibrillar MgATPase activity (mean +/- S.E.M.) at 21-22 degrees C was found to be 3.80 +/- 0.53 molecules MgATP hydrolysed s-1 per myosin head for eight rat fibres and 6.35 +/- 0.77 s-1 per myosin head for four toad fibres. 3. At sarcomere lengths shorter than 2.7 microns in rat fibres and 2.2 microns in toad fibres, MgATPase and stiffness remained elevated and close to their respective values at 2.7 microns in rat fibres and 2.2 microns in toad fibres even when the isometric force decreased to near zero levels. 4. The dissociation at short sarcomere lengths of myofibrillar MgATPase activity and fibre stiffness from isometric force suggests that the cross-bridge cycle is not greatly affected by double actin filament overlap with the myosin filaments at short sarcomere lengths. Moreover, the results suggest that cross-bridges can be formed by myosin with actin filaments projecting from the nearest Z-line and from the Z-line in the other half of the sarcomere. 5. These results help to reconcile energetic and mechanical data obtained by others at short sarcomere lengths and can be explained within the framework of the sliding filament theory.
Collapse
|
152
|
Pattemore PK, Asher MI, Harrison AC, Mitchell EA, Rea HH, Stewart AW. Ethnic differences in prevalence of asthma symptoms and bronchial hyperresponsiveness in New Zealand schoolchildren. Thorax 1989; 44:168-76. [PMID: 2705146 PMCID: PMC461746 DOI: 10.1136/thx.44.3.168] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Maoris and Pacific Islanders in New Zealand have a higher asthma mortality and hospital admission rates than Europeans. To determine whether difference in asthma prevalence is the major factor underlying these differences in mortality, 2053 Auckland children aged 7-10 years (European 1084, Maori 509, Pacific Islander 460) were randomly sampled from school classes in the Auckland Urban Area, and studied by questionnaire (completed by parents) and histamine inhalation challenge to assess the provocative dose of histamine causing a 20% fall in FEV1 (PD20). Maoris had the highest prevalence rates of respiratory symptoms, and Europeans had rates similar to Pacific Islanders. For "any current wheeze" for example, the prevalence in Maoris was 22.2% compared with 16.1% and 16.3% in the Europeans and Pacific Islanders. The prevalence of diagnosed asthma was similar in the three groups. When bronchial hyperresponsiveness (defined as a PD20 less than or equal to 7.8 mumol histamine) was considered, Europeans had the highest rates (20%), followed by Maoris (13%), and then Pacific Islanders (8.7%). These differences were not accounted for by differences in socioeconomic status, rates of smoking in the home, age, gender, or height. It is concluded that differences in asthma prevalence do not satisfactorily explain the mortality and admission rate differences, although the higher symptom prevalence in the Maoris could be relevant to the higher mortality rate. Maori and Pacific Island children with symptoms of asthma were less likely to be taking prophylactic medication than European children. It is proposed that differences in management are important factors relevant to the increased mortality and morbidity from asthma in Polynesians.
Collapse
|
153
|
Mitchell EA, Stewart AW. Deaths from sudden infant death syndrome on public holidays and weekends. AUSTRALIAN AND NEW ZEALAND JOURNAL OF MEDICINE 1988; 18:861-3. [PMID: 3250410 DOI: 10.1111/j.1445-5994.1988.tb01646.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Deaths from sudden infant death syndrome (SIDS) between 1979 and 1984 were tabulated by month for weekdays, weekends and public holidays. Examination of deaths by day of the week showed the weekend had more deaths than the weekdays (chi 2 = 26.3, df = 6, p = 0.0002) and that this pattern occurred in both the under three months and three-11 months age group. There were 40 deaths on the 78 public holidays in the six years under study. Modelling the data showed that there was no difference between the number of deaths on holidays compared to weekends.
Collapse
|
154
|
Asher MI, Pattemore PK, Harrison AC, Mitchell EA, Rea HH, Stewart AW, Woolcock AJ. International comparison of the prevalence of asthma symptoms and bronchial hyperresponsiveness. THE AMERICAN REVIEW OF RESPIRATORY DISEASE 1988; 138:524-9. [PMID: 3202407 DOI: 10.1164/ajrccm/138.3.524] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Potential explanations for the higher rates of asthma mortality and hospital admissions in New Zealand (NZ) include greater prevalence of asthma. To evaluate this further, a large community survey has been undertaken. Rates of respiratory symptoms and bronchial hyperresponsiveness (BHR) for children in Auckland, NZ have been compared to those for children in two locations in New South Wales (NSW), Australia: Wagga Wagga (inland) and Belmont (coastal). The methodology used was the same in both studies: parent-completed questionnaire and BHR measured by response to an abbreviated histamine challenge. In Auckland, 1,084 children participated (84% of those selected) and were compared to 769 inland NSW and 718 coastal NSW children. The prevalence of respiratory symptoms, BHR, severity of BHR, and BHR combined with symptoms was similar among Auckland and inland NSW children but lower among coastal NSW children than those from the other two sites. It is concluded that other unidentified factors must be invoked to explain mortality and admission differences between these regions.
Collapse
|
155
|
Stewart AW, Fraser J, Norris RM, Beaglehole R. Changes in severity of myocardial infarction and three year survival rates after myocardial infarction in Auckland, 1966-7 and 1981-2. BMJ (CLINICAL RESEARCH ED.) 1988; 297:517-9. [PMID: 2971419 PMCID: PMC1840348 DOI: 10.1136/bmj.297.6647.517] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Mortality from coronary heart disease has been declining steadily over the past 20 years in Auckland. The possibility that improved survival contributed to this decline was examined in patients who survived four weeks after myocardial infarction, changes in the severity of the disease being controlled for. Patients who had had myocardial infarction in 1966-7 (191 patients) or 1981-2 (203) were compared to determine whether three year survival rates had changed and the severity of the disease altered. With a coronary prognostic index taken as the measure of severity the 1981-2 group had significantly more severe myocardial infarctions than the 1966-7 group, but despite this the three year survival was significantly better (86% in the 1981-2 group v 75% in the 1966-7 group). These findings suggest that improved survival after myocardial infarction contributed to the decline in mortality.
Collapse
|
156
|
Abstract
We examined characteristics associated with a high risk of mortality within 3 years after a stroke. Analyses are based on data from a population-based register of stroke events that occurred in Auckland (total population 829,545), New Zealand during a 1-year period in 1981-1982 and a 3-year follow-up study of all survivors (97% complete). Statistical techniques that allow for the simultaneous evaluation of multiple factors indicated that retention of consciousness, decreasing age, and place of residence at the onset of the stroke were the strongest predictors of survival over 3 years. The survival rate for those living at home at the onset of the stroke who did not lose consciousness was 58% compared with 5% for people in institutional care who lost consciousness. Marital status, history of stroke, and ethnic group also predicted survival. Most of the important prognostic factors we identified in our study cannot be modified, testifying to the importance of the prevention of stroke in the first place.
Collapse
|
157
|
Jones RW, Yeong ML, Stewart AW, Hitchcock GC, Dervan WE. Cervical cytology in the Auckland region. THE NEW ZEALAND MEDICAL JOURNAL 1988; 101:132-5. [PMID: 2832794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
A two week prospective study of the characteristics of women having cervical smears in the Auckland region in 1985 is presented. European and Maori women have about the same rate of smears while Pacific Islanders have a slightly lesser rate. Many women are not having smears taken during pregnancy or at the postnatal examination. Doctors initiate twice as many smears as their patients. More than half of the women had smears taken in less than the three year interval recommended for screening. Five per cent of smears have some degree of cervical intraepithelial neoplasia (CIN) and nearly half of these showed evidence of human papilloma virus (HPV) infection. There is a spectrum extending from young women in their early twenties with HPV infection alone through their later twenties with HPV and CIN and finally women in their thirties and forties with carcinoma-in-situ (CIS) alone.
Collapse
|
158
|
Asher MI, Douglas C, Stewart AW, Quinn JP, Hill PM. Lung volumes in Polynesian children. THE AMERICAN REVIEW OF RESPIRATORY DISEASE 1987; 136:1360-5. [PMID: 3688639 DOI: 10.1164/ajrccm/136.6.1360] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Polynesian (Maori and Pacific Island) children account for approximately one quarter of the children in New Zealand, but good data for lung function in this group are not available. In this review, we report lung volume measurements in 571 healthy children 5 to 13 yr of age: 270 Polynesians (139 boys and 131 girls) and 301 Europeans (177 boys and 124 girls). All measurements were made in a body plethysmograph. Polynesian boys had significantly larger VC, FVC, FRC, TLC, and expiratory reserve volume than did Polynesian girls. Polynesian and European children generally showed different slope and intercept relationships for the prediction of lung volume from height. Racial differences are not adequately explained by differences in body proportions or social factors including parental smoking. Possible explanations include racial differences in lung growth and maturation.
Collapse
|
159
|
Mason BH, Holdaway IM, Skinner SJ, Stewart AW, Kay RG, Neave LM, Anderson J. Association between season of first detection of breast cancer and disease progression. Breast Cancer Res Treat 1987; 9:227-32. [PMID: 3663959 DOI: 10.1007/bf01806384] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The season of recurrence of tumour was investigated by follow-up of 1324 patients with breast cancer and compared with the season of initial tumour detection. Unlike primary tumours, where an increased incidence of detection has previously been observed in late spring and early summer, there was no significant seasonal variation in the time of recurrence. However, women with oestrogen receptor positive or progesterone receptor negative primary tumours recurred significantly more frequently in the same season that their primary cancer was initially detected. Overall there was an increased frequency of recurrence one year from diagnosis. Women less than age 50 who initially found their tumour in winter or autumn had a significantly shorter disease-free interval before recurrence than those first detecting their tumour in summer or spring. This relationship was independent of nodal status and tumour size. Tumours initially detected in winter or autumn thus appeared to follow a more aggressive growth profile. This study indicates that the season of first detection of a breast cancer relates significantly to aspects of the future biologic behaviour of the tumour.
Collapse
|
160
|
Beaglehole R, Stewart AW, Butler M. Comparability of old and new World Health Organization criteria for definite myocardial infarction. Int J Epidemiol 1987; 16:373-6. [PMID: 3667034 DOI: 10.1093/ije/16.3.373] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
New epidemiological criteria for definite myocardial infarction are now in use as part of the international study of trends and determinants of cardiovascular disease coordinated by the World Health Organization (MONICA Project). In this paper we use data from a myocardial infarction register to assess the comparability of the old and new World Health Organization criteria for definite myocardial infarction. The new criteria were applied to 905 cases who had been categorized as definite myocardial infarction on the old criteria. 739 (82%) of these cases met the new criteria for definite myocardial infarction; a further 157 cases (17%) met the new criteria for possible myocardial infarction. This study indicates that the two sets of criteria produce results that are too dissimilar for reliable comparisons to be made between studies using different criteria for definite myocardial infarction.
Collapse
|
161
|
Schellenberg JC, Liggins GC, Stewart AW. Growth, elastin concentration, and collagen concentration of perinatal rat lung: effects of dexamethasone. Pediatr Res 1987; 21:603-7. [PMID: 3601477 DOI: 10.1203/00006450-198706000-00019] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The ontogenesis of elastin and collagen accumulation and growth of the lung were studied in Wistar rats from day 18 of gestation until day 30 postnatally. Dexamethasone phosphate 0.1 mg or normal saline solution every 8 h for three doses was injected into pregnant rats on day 17. The effects of treatment, age, and sex on lung wet weight, lung dry weight, body weight, DNA, protein and desmosine (estimated by radioimmunoassay), and hydroxyproline were determined in the offspring. Dexamethasone inhibited lung growth and, to a lesser extent, body weight gain. While lung wet weight, lung dry weight, and body weight remained significantly reduced until postnatal day 15, the lung weight/body weight ratio was depressed only until postnatal day 5. The lung dry weight/lung wet weight ratio was decreased on day 20 of gestation and at birth. DNA concentration remained slightly but significantly reduced throughout the study period. Desmosine but not hydroxyproline concentration was lower after dexamethasone treatment during the period of rapid postnatal desmosine accumulation (day 10 p less than 0.05, day 15 p less than 0.01, day 20 p = 0.06).
Collapse
|
162
|
Aman MG, Richmond G, Stewart AW, Bell JC, Kissel RC. The aberrant behavior checklist: factor structure and the effect of subject variables in American and New Zealand facilities. AMERICAN JOURNAL OF MENTAL DEFICIENCY 1987; 91:570-8. [PMID: 3591845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The Aberrant Behavior Checklist was used to collect data from a large United States institution for comparison with ratings previously obtained in New Zealand. A total of 531 subjects within the American facility and 937 residents of New Zealand institutions were studied. The United States data were factor analyzed using the same procedures that were employed to develop the scale in New Zealand. In addition, subscales of the Checklist were analyzed as a function of sex, age, country, and level of mental retardation. Finally, the effects of various medical conditions were analyzed. The original factor structure of the Checklist was validated for the United States sample, with a mean coefficient of congruence of .93 averaged across the five factors. Sex failed to influence subscale scores, whereas age, country, and severity of retardation significantly affected ratings. Deafness was unrelated to Checklist scores whereas cerebral palsy, epilepsy, psychosis, and psychoactive drug treatment were related.
Collapse
|
163
|
Beaglehole R, Stewart AW, Walker P. Validation of coronary heart disease hospital discharge data. AUSTRALIAN AND NEW ZEALAND JOURNAL OF MEDICINE 1987; 17:43-6. [PMID: 3476046 DOI: 10.1111/j.1445-5994.1987.tb05048.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Data from a 1983 Auckland coronary heart disease register applying current World Health Organization criteria have been used to validate routine hospital discharge data. The register contained 905 patients under 65 years admitted to hospital and 858 of these patients were matched with hospital discharge records. Of the registered definite myocardial infarction cases 86% received the International Classification of Diseases code 410 (acute myocardial infarction); 9% of these cases received a code 411-414 (other forms of coronary heart disease or angina) and 5% received other codes. Only 405 of the 604 cases (67%) coded 410 in the hospital discharge data were true definite myocardial infarctions according to the World Health Organization criteria. The routine hospital International Classification of Diseases data do not provide diagnostic groups sufficiently close to World Health Organization categories for them to be used alone to monitor trends in coronary heart disease morbidity rates.
Collapse
|
164
|
Stewart AW, Jackson RT, Ford MA, Beaglehole R. Underestimation of relative weight by use of self-reported height and weight. Am J Epidemiol 1987; 125:122-6. [PMID: 3788941 DOI: 10.1093/oxfordjournals.aje.a114494] [Citation(s) in RCA: 236] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Self-reported and measured height and weight were obtained from a representative sample of 1,598 persons in Auckland, New Zealand during 1982. The accuracy of the self-reported data and its effect on the misclassification of relative weight, as measured by Quetelet index, were examined. The finding that for most participants (75%), self-reported measures were no more than 3.5 cm from their measured height and 2.4 kg from their measured weight indicates that self-reports have a high degree of accuracy. However, the participants consistently overestimated their height and underestimated their weight, resulting in an underestimation of relative weight. This would have little effect on analyses using the self-reported relative weight measures as a continuous covariate, but misclassification would occur when using relative weight as a categorical variable. The sensitivities and specificities associated with categorized self-reported relative risks that have been calculated from relative weight derived from self-reported height and weight.
Collapse
|
165
|
Stewart AW, Beaglehole R, Fraser GE, Sharpe DN. Has the long term prognosis following myocardial infarction improved? THE NEW ZEALAND MEDICAL JOURNAL 1986; 99:403-5. [PMID: 3461351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Coronary heart disease mortality in New Zealand has declined by 25% in the 15 years since 1968. One possible explanation for this decline is lower case-fatality rates resulting from improvements in the management of myocardial infarction. This paper tests this hypothesis by examining trends in three year survival following a definite myocardial infarction for the population aged 35-69 in Auckland. The data were obtained from two methodologically identical population-based registers of myocardial infarction compiled in Auckland in 1974 and 1981. The three year survival rates were 59% and 65% for the two time periods respectively and this difference did not reach statistical significance. However, as the survival curves appear to be diverging, there may have been a small improvement in long term outcome after myocardial infarction.
Collapse
|
166
|
Wesley AW, Stewart AW. Cystic fibrosis in New Zealand: incidence and mortality. THE NEW ZEALAND MEDICAL JOURNAL 1985; 98:321-3. [PMID: 3858714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The incidence of and mortality from cystic fibrosis in New Zealand from 1960 to 1983, has been reviewed. Cystic fibrosis subjects have been located from data obtained from New Zealand paediatricians, the Cystic Fibrosis Association and hospital admission records. Mortality figures in the years 1960-1982 were also obtained. The incidence of cystic fibrosis of 1: 3179 non-Maori births was similar to that reported previously. Those born during 1970-1983, have a significantly better survival than those born before 1970. The survival figures are similar to those in England and Wales, but are considerably lower than those reported from Canada, or cystic fibrosis centres in the United States and Australia.
Collapse
|
167
|
Stewart AW. Muscle fluorometry: a determination of the depth of penetration. EXPERIENTIA 1985; 41:456-8. [PMID: 3987867 DOI: 10.1007/bf01966144] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Fluorometric recordings of NADH (nicotinamide adenine dinucleotide) were made on rabbit papillary muscles. The specimens were placed between the UV light source and a small window of the detection stage. As the muscle was moved over the window in a transverse direction, simultaneous measurements could be taken of transmitted UV light and fluorescent light for various thicknesses of tissue. It is concluded that a muscle thickness of 0.65 mm is optimal before absorption of the incident light decreases the fluorescence signal.
Collapse
|
168
|
Aman MG, Singh NN, Stewart AW, Field CJ. Psychometric characteristics of the aberrant behavior checklist. AMERICAN JOURNAL OF MENTAL DEFICIENCY 1985; 89:492-502. [PMID: 3158201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Information was presented on the psychometric characteristics of the Aberrant Behavior Checklist. The internal consistency and test-retest reliability of the Checklist appeared to be very good. Interrater reliability tended to vary across raters and subscales and ranged from mediocre to good but was generally in the moderate range and acceptable for research purposes. Validity was assessed by comparing Checklist scores for residents presenting with attributes thought to reflect varying degrees of social adaptation. Validity was also evaluated by comparing Aberrant Behavior Checklist scores with ratings on adaptive behavior scales and with objective observations of behavior. In general, validity was established for most Aberrant Behavior Checklist subscales. Preliminary data from drug investigations suggested that the Checklist may provide a useful adjunct for the assessment of psychotropic drug effects.
Collapse
|
169
|
Aman MG, Singh NN, Stewart AW, Field CJ. The aberrant behavior checklist: a behavior rating scale for the assessment of treatment effects. AMERICAN JOURNAL OF MENTAL DEFICIENCY 1985; 89:485-91. [PMID: 3993694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The development of a scale to assess drug and other treatment effects on severely mentally retarded individuals was described. In the first stage of the project, an initial scale encompassing a large number of behavior problems was used to rate 418 residents. The scale was then reduced to an intermediate version, and in the second stage, 509 moderately to profoundly retarded individuals were rated. Separate factor analyses of the data from the two samples resulted in a five-factor scale comprising 58 items. The factors of the Aberrant Behavior Checklist have been labeled as follows: (I) Irritability, Agitation, Crying; (II) Lethargy, Social Withdrawal; (III) Stereotypic Behavior; (IV) Hyperactivity, Noncompliance; and (V) Inappropriate Speech. Average subscale scores were presented for the instrument, and the results were compared with empirically derived rating scales of childhood psychopathology and with factor analytic work in the field of mental retardation.
Collapse
|
170
|
Beaglehole R, Stewart AW, Bonita R, Jackson RT, Sharpe DN. Myocardial infarction and sudden death in Auckland. THE NEW ZEALAND MEDICAL JOURNAL 1984; 97:715-8. [PMID: 6595557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
A population-based register of definite myocardial infarction and sudden death was established in Auckland for the twelve months from 1 March 1981. Data were collected on 905 myocardial infarctions and 300 sudden deaths that occurred in people under the age of 70 years. The age standardised event rates were more than three times higher in men than in women. The rates of myocardial infarction were comparable in Maoris and non-Maoris but the sudden death rate was almost three times higher in Maoris than in the other ethnic groups. The age standardised 28 day myocardial infarction case fatality rates were 27% and 21% for men and women respectively. Overall, 42% of patients who reached hospital were transported by a life support unit, and 59% of patients who reached a coronary care unit did so within four hours of onset.
Collapse
|
171
|
Abstract
Coronary heart disease mortality in New Zealand has declined by 20% in the 13 years since 1968. One possible explanation for this decline is lower case-fatality rates resulting from improvements in the management of myocardial infarction. This paper tests this hypothesis by examining trends in 1-year survival following a definite myocardial infarction for the population aged 35-69 in Auckland. The data were obtained from two methodologically identical population-based registers of myocardial infarction compiled in 1974 and 1981 in Auckland. In both periods the 1-year crude case-fatality rate was 30% and the pattern of survival over 1 year was similar. These data suggest that factors other than the improved care of myocardial infarction patients are responsible for the decline in coronary heart disease mortality rates in New Zealand.
Collapse
|
172
|
Jackson RT, Beaglehole R, Stewart AW. Blood pressure levels and the treatment of hypertension in Auckland, 1982. THE NEW ZEALAND MEDICAL JOURNAL 1983; 96:751-4. [PMID: 6604888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The level of coronary heart disease risk factors in a random sample of 1598 people aged 35-64 years was examined in Auckland in 1982. Blood pressure was measured and the prevalence of treated and untreated hypertension determined. Mean systolic blood pressure increased with age from 124 mmHg (16.49 kPa) in men aged 35-39 years to 144 mmHg (19.15 kPa) in those aged 60-64 years, and from 115 mmHg to 140 mmHg (15.29-18.62 kPa) in women in the same age groups. Compared with previous New Zealand studies blood pressure levels were lower in this study and considerably more people were on antihypertensive treatment. Hypertension is still a major problem in Auckland with 21% of men and 19% of women aged 35-64 years either hypertensive or on antihypertensive treatment. Although half of these people were on treatment, 16% of men and 9% of women in this age group in Auckland were estimated to have a blood pressure level in the hypertensive range.
Collapse
|
173
|
Stewart RJ, Stewart AW, Turnbull PR, Isbister WH. Sex differences in subsite incidence of large-bowel cancer. Dis Colon Rectum 1983; 26:658-60. [PMID: 6884156 DOI: 10.1007/bf02553336] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
A review of patients with large-bowel cancer at a major New Zealand hospital showed an excess of right-sided colonic tumors in females compared with males. These observations stimulated analysis of the National Cancer Registry registration data for large-bowel cancer for the whole of New Zealand in the years 1972 to 1975 (4678 patients). Rates for each site were calculated and age-standardized, using world population figures. The findings confirmed that females have a higher incidence of right-sided colonic cancer and males a higher incidence of rectal cancer and showed a significant trend in this direction from the ascending colon toward the rectum. The observed differences between males and females suggest differences in the etiology of the tumor and should be taken into account in assessing modalities and outcomes of treatment.
Collapse
|
174
|
Stewart RJ, Stewart AW, Stewart JM, Ibister WH. Cancer of the pancreas in New Zealand 1970-1974. THE AUSTRALIAN AND NEW ZEALAND JOURNAL OF SURGERY 1982; 52:379-84. [PMID: 6956313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
There were 991 new cases of cancer of the exocrine pancreas in the New Zealand population for the five years 1970-74. The disease had a higher incidence in men than women and in Maoris compared to Europeans. There was no increase in incidence in the period 1950-52 to 1971-73. Most of the cancers occurred in the head of the pancreas and were described as adenocarcinomas. Seventy seven per cent of the patients had lymph node metastases or advanced disease at the time of diagnosis. Only 7 per cent were able to have resectional surgery and in 90% specific therapy was not given. The estimated crude three-year survival rate of all patients was four per cent and the median survival time was 1.7 months. The crude three year survival rate after resection was 9.8% and the median survival time was 5.8 months. The most important variables affecting survival were stage of disease and age of patient.
Collapse
|
175
|
Stewart RJ, Stewart AW, Stewart JM, Isbister WH. Cancer of the stomach in New Zealand: 1970-74. THE AUSTRALIAN AND NEW ZEALAND JOURNAL OF SURGERY 1982; 52:363-9. [PMID: 6956310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
A total of 1,891 new cases of cancer of the stomach occurred in New Zealand (1971 population 2,862,631) in the five years 1970-74. There was a higher incidence in men than women and in Maoris compared to Europeans. The disease had declined in incidence by about 50% in 20 years. Most of the cancers occurred in the distal stomach and were described as adenocarcinomas. Seventy percent of the patients had a lymph node metastases or advanced disease at the time of diagnosis. Only 39% were able to have resectional surgery and in 57% specific therapy was not given. The estimated crude five year survival rate of all patients was 7.8% (relative rate 10.2%) and the crude five year survival rate after resectional surgery was 18.7% (relative rate 24.7%). The most important variables affecting survival were the stage of the disease and the age of the patient.
Collapse
|
176
|
Lever M, Munster DJ, Walmsley TA, Stewart AW. Analytical errors in clinical laboratories as assessed by an interlaboratory survey. Ann Clin Biochem 1981; 18:28-36. [PMID: 7259062 DOI: 10.1177/000456328101800107] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Combined errors ar the commonest systematic errors in laboratory results and occur with most tests studied. In these errors, results are reduced (or, less commonly, increased) by a factor, and this effect is compensated by the addition (or subtraction) of a constant amount. The effect is that results are in error in opposite direction at high and low levels. Inconsistency is predominant and is due mainly to imprecision, although for some tests (iron, cholesterol, calcium, and triglycerides among those studied) other factors such as non-specificity are significant. An interlaboratory survey based upon external method assessment using linear regression analysis provided objective information about analytical error in laboratories which is not usually obtained, while at the same time meeting the usual functions of surveys in the quality audit of performance.
Collapse
|
177
|
Dunn PJ, Donald RA, Day T, Stewart JM, Stewart AW. The association between diabetic retinopathy and skeletal muscle capillary basal lamina thickening corrected for the influence of age and duration of diabetes. Diabetes 1979; 28:858-64. [PMID: 467812 DOI: 10.2337/diab.28.9.858] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The association between an objective measure of diabetic retinopathy and skeletal muscle capillary basal lamina thickness was examined in a group of 30 male insulin-treated diabetic subjects, mean age (+/- SD) 44.6 +/- 13.2 yr, duration of diabetes 21.2 +/- 11.2 yr, % ideal body weight (% IBW) 106 +/- 11%. In addition, muscle capillary basal lamina width was measured in a group of 18 nondiabeitc men, mean age 40.7 +/- 16.3 yr and % IBW 118 +/- 23%. The muscle capillary width of the diabetic subjects was significantly greater than that of the nondiabetic group (P less than 0.01), but the values of the two overlapped considerably. In the diabetic group, there was a significant association of basal lamina width with age (P less than 0.01) but not with duration of diabetes. The association between extent of retinopathy and muscle capillary basal lamina width was not strong. The findings of the study do not therefore support the use of an estimate of muscle capillary basal lamina thickness as a single representative measure of diabetic microangiopathy.
Collapse
|
178
|
Stewart RJ, Robson RA, Stewart AW, Stewart JM, Macbeth WA. Cancer of the large bowel in a defined population: Canterbury, New Zealand, 1970--4. Br J Surg 1979; 66:309-14. [PMID: 444847 DOI: 10.1002/bjs.1800660505] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
A total of 1024 new cases of cancer of the large bowel occurred in Canterbury, New Zealand (population 400,796), in the 5 years 1970--4. Of these, 992 were diagnosed before death and are reviewed in this paper. The high incidence of this disease in New Zealanders of European origin is illustrated. A significant difference in site distribution of primary tumours between the sexes was found, with a female preponderance of cancer of the proximal colon gradually changing to a male preponderance of cancer of the rectum. In all, 61.5 per cent of the patients had lymph node metastases or advanced disease at the time of diagnosis or treatment. Largely as a consequence of this, only 65 per cent were able to have potentially curative treatment. The estimated crude 5-year survival rate of the whole group was 32.7 per cent (relative rate 42.8 per cent) and the crude 5-year survival rate after potentially curative surgery was 48.4 per cent (relative rate 62.4 per cent). The results are compared with those of other authors. They emphasize the generally unsatisfactory outcome of treatment.
Collapse
|
179
|
Campbell CB, McGuffie C, Powell LW, Roberts RK, Stewart AW. Postprandial changes in serum concentrations of individual bile salts in normal subjects and patients with acute viral hepatitis. THE AMERICAN JOURNAL OF DIGESTIVE DISEASES 1978; 23:599-608. [PMID: 685925 DOI: 10.1007/bf01072594] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
|
180
|
Stewart AW, Johnson MG. Increased numbers of heat-resistnat spores produced by two strains of Clostridium perfringens bearing temperate phage s9. JOURNAL OF GENERAL MICROBIOLOGY 1977; 103:45-50. [PMID: 201726 DOI: 10.1099/00221287-103-1-45] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Sporulation kinetics and spore heat resistance data were compared for a lysogenic strain of Clostridium perfringens, s9, before and after curing with ultraviolet irradiation. The cured strain showed the same growth rate in broth media as the lysogenic strain but took 6 h longer to form refractile spores. For lysogenized and cured strains the percentages of refractile spores produced that were heat-resistant (80 degrees C for 15 min) were 50 and 0.2, respectively. When reinfected with the temperature phage, the cured strain produced spores in 2 to 3 h, like the original lysogenic culture, and 10% of the spores produced were heat-resistnat.
Collapse
|
181
|
McClean HE, Stewart AW, Riley CG, Beaven DW. Vitamin C status of elderly men in a residential home. THE NEW ZEALAND MEDICAL JOURNAL 1977; 86:379-82. [PMID: 272548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The vitamin C status of 35 men, over 70 years of age from a residential home has been studied by measuring the plasma and leucocyte vitamin C levels and by assessing the intake of vitamin C. The mean plasma vitamin C level of the group was 16 +/- 15 mumol/l which was significantly lower (P less than 0.005) than that of a similar group of elderly men living alone (26 +/- 20 mumol/l). The mean leucocyte vitamin C levels of the two groups did not differ significantly. Twenty-nine (83 percent) of the institution group had plasma vitamin C levels below 23 mumol/l and 13 men (37 percent) had leucocyte vitamin C levels below 10 microgram/10(8)WBC. The residents who supplemented the institution diet with their own fresh fruit supplies had higher plasma and leucocyte vitamin C levels than the men who did not (P less than 0.01). Some clinical signs possible related to vitamin C deficiency were recorded but these could not later be statistically related to either plasma or leucocyte vitamin C levels. A case is made for vitamin C supplementation of puddings in institutional meals for the elderly.
Collapse
|
182
|
McClean HE, Dodds PM, Stewart AW, Beaven DW, Riley CG. Nutrition of elderly men living alone. Part 2, Vitamin C and thiamine status. THE NEW ZEALAND MEDICAL JOURNAL 1976; 84:345-8. [PMID: 1071143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
A dietary survey using the five day record method was carried out on 35 elderly men living alone in the Christchurch area. The mean calculated intake of vitamin C for these men was 31 mg/day. These dietary intakes of vitamin C were significantly correlated with both plasma vitamin C levels and with leucocyte vitamin C levels. Twelve men (34 percent) with lowered dietary intakes of vitamin C were in the range for asymptomatic scurvy. The mean calculated intake of thiamine was 1.05 mg/day. The mean TPP effect was 12.9 percent (n = 27). Dietary intakes of thiamine showed a significant inverse relationship with TPP effect. Eight subjects (23 percent) who too, less than the Australian dietary allowance had an elevated TPP effect. By both dietary and biochemical methods there was evidence of subclinical vitamin C and thiamine deficiencies in more than a quarter of these men.
Collapse
|
183
|
McClean HE, Dodds PM, Abernethy MH, Stewart AW, Beaven DW. Vitamin C concentration in plasma and leucocytes of men related to age and smoking habit. THE NEW ZEALAND MEDICAL JOURNAL 1976; 83:226-9. [PMID: 1066535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Morning plasma and leucocyte vitamin C concentrations were measured in 178 healthy men aged 17-68 years. In the youngest age group (17-29 years), smokers had significantly lower plasma (P less than 0.01) and leucocyte (P less than 0.001) vitamin C levels than non-smokers. With advancing age plasma and leucocyte vitamin C levels of non-smokers appeared to decline. The lower levels in younger smokers did not significantly alter in the later decades. There was no significant difference between the plasma or leucocyte vitamin C levels of smokers and non-smokers in the decade 60-69 years.
Collapse
|
184
|
McQuaide JR, Stewart AW. Familial polyposis of the colon in the Bantu. S Afr Med J 1972; 46:1241-6. [PMID: 4638220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
|
185
|
Russell JT, Stewart AW, Kessler A. The design and function of an intensive care unit. S Afr Med J 1968; 42:931-3. [PMID: 5687811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
|