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Biomedical subjects

R Jackson

Publications and source records attributed to R Jackson.

At least 289 records · Page 16Linked to original sources

Validation of a three-month physical activity recall questionnaire with a seven-day food intake and physical activity diary.

We assessed the validity of a three-month physical activity questionnaire. The validation instrument was a seven-day self-report diary of physical activity and food intake, given to 113 randomly selected persons. We obtained Spearman correlations of 0.60, 0.48, and 0.91 and kappa scores of 0.36, 0.23, and 0.62 from the physical activity recall and diary for moderate, vigorous, and total activity. We conclude that the three-month recall questionnaire reasonably reflects activity in this community-based sample.

Diet↗

Corticotrophin releasing hormone (CRH1-41) stimulates the secretion of adrenocorticotrophin, vasopressin and oxytocin but not adrenocorticotrophin precursors: evidence from petrosal sinus sampling in man.

To examine the relationship between corticotrophin releasing hormone (CRH), arginine vasopressin (AVP) and oxytocin (OXT) we have studied the responses of adenohypophyseal and neurohypophyseal hormones to CRH in eight patients (age 26-64 years, six female) with suspected pituitary-dependent Cushing's syndrome during bilateral, simultaneous inferior petrosal sinus catheterization. Blood samples were taken from both petrosal sinuses and a peripheral vein before, and at 5-min intervals for 15 min after, an intravenous injection of 100 micrograms human CRH1-41. CRH increased sinus AVP concentrations in all eight patients and OXT concentrations in four of five patients studied. Although AVP concentrations often increased in both sinuses, the side of maximal AVP rise was termed side(max-AVP). CRH did not affect peripheral or petrosal sinus mean concentrations of LH, FSH, GH or TSH. While there was no change in mean peripheral concentrations of AVP, OXT, ACTH, ACTH precursors or prolactin after CRH, sinus concentrations of OXT, ACTH and prolactin on side(max-AVP) were markedly elevated over contralateral values. CRH did not increase mean sinus concentrations of ACTH precursors. In seven patients with either no radiological abnormality or the pituitary fossa or a small adenoma the mean ACTH precursor/ACTH ratio in blood sampled from all sites was 2.1 +/- 0.16 (mean +/- SEM, n = 50). In a patient with a large, locally invasive tumour the mean ACTH precursor/ACTH molar ratio was 32.1 +/- 1.3 (n = 12; P less than 0.001), suggesting that alterations in this molar ratio may reflect the biological properties of the tumour. The source of CRH-stimulatable AVP and OXT remains uncertain.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenocorticotropic Hormone↗

Pneumococcal septic arthritis after splenectomy in Felty's syndrome.

A patient with Felty's syndrome who developed bilateral knee septic arthritis and septicaemia due to Streptococcus pneumoniae is described. She had had a previous splenectomy for symptomatic thrombocytopenia, having received pneumococcal vaccine before the operation. Measurement of antibody to the 23 vaccine serotypes showed protective concentrations before infection to just two. The infecting serotype was not represented in the vaccine, but a vigorous antibody response to this serotype occurred. The patient also developed glomerulonephritis due to immune complex deposition.

Adult↗

Toward an expanded vision of clinical ethics education: from the individual to the institution.

This paper advances a new paradigm in clinical ethics education that not only emphasizes development of individual clinicians' skills, but also focuses on the institutional context within which health care professionals work. This approach has been applied to the goal of improving the care provided to critically and terminally ill adults. The model has been adopted by about thirty hospitals and nursing homes; additional institutions will soon join the program, entitled Decisions Near the End of Life. Here, we describe the history and rationale for this approach, its goals, pedagogical assumptions, and design.

Curriculum↗

Long term survival after intensive care.

OBJECTIVE: To examine the long term survival of critically ill patients admitted to an intensive therapy unit and to ascertain the effects of age, severity of illness, and diagnostic category at admission on survival. DESIGN: Retrospective observational study with prospectively gathered data on all patients admitted to the unit between June 1985 and July 1987 and followed up until 1 January 1989. SETTING: Regional intensive therapy unit. PATIENTS: 513 critically ill adult patients, 16 of whom were excluded because measurements on severity of illness scoring were not available. MAIN OUTCOME MEASURES: Age, severity of illness (determined with the acute physiology and chronic health evaluation (APACHE) II score), and diagnostic category on admission; deaths in the unit; and long term survival after discharge. Details of the survivors were sent to the Registrar General for Scotland, who issued copies of death certificates for the patients who had died between discharge and 1 January 1989. RESULTS: Of 497 patients, 119 (24%) died in the intensive therapy unit and 120 (24%) after discharge, leaving 258 (52%) who were still alive at two years. The median (APACHE II) score was 13 and about half of the patients were aged 55 years or more. A wide range of critical illnesses, except neurosurgical emergencies, were treated. Survival analysis showed that only 41 (34%) of 122 patients with an APACHE II score of greater than or equal to 20 were alive at one year (95% confidence interval 25 to 42) compared with 124 (80%) of 155 patients with a score of less than 10 (73 to 87). Of the 144 patients aged 65 or more, only 68 (47%) survived to one year (39 to 55) but 90 (83%) of the 109 patients aged between 18 and 34 survived a similar period (76 to 71). Mortality was also related to diagnostic category; 71% of trauma victims survived to one year compared with only 41% of those admitted with gastrointestinal pathology. Univariate analysis of the results showed that age, severity of illness, and diagnosis were all predictors of long term survival. Multivariate analysis, however, showed that only age and severity of illness were independent prognostic factors. CONCLUSIONS: Long term survival of patients treated in an intensive therapy unit is related to severity of illness and to age. The outcome from critical illness in the elderly population is poor.

Adolescent↗

Trends in cardiovascular risk factors in Auckland, 1982 to 1987.

This paper examines trends in Auckland over a five year period (1982-87) in the major cardiovascular risk factors: serum total cholesterol, blood pressure and cigarette smoking; trends in body mass index are also presented. The data came from two independent random samples of European people aged 40-64 years chosen from the central Auckland electoral rolls in 1982 (915 men and 476 women) and 1986-88 (503 men and 359 women); response rates were over 80% in both surveys. In the five year period self reported smoking declined by 22% in men and 10% in women; the decline was particularly marked in upper socioeconomic men and women aged 55-64 years. There were no consistent changes in either blood pressure or body mass index levels. Serum cholesterol levels, after adjustment for the change in laboratory methods, declined by approximately 1% in both men and women. Cardiovascular risk factor levels remain high in Auckland; comprehensive population based prevention programmes, such as Heartbeat (New Zealand), are urgently required in New Zealand.

Adult↗

Low mortality associated with low volume pressure limited ventilation with permissive hypercapnia in severe adult respiratory distress syndrome.

Many animal studies have shown that high peak inspiratory pressures (PIP) during mechanical ventilation can induce acute lung injury with hyaline membranes. Since 1984 we have limited PIP in patients with ARDS by reducing tidal volume, allowing spontaneous breathing with SIMV and disregarding hypercapnia. Since 1987 50 patients with severe ARDS with a "lung injury score" greater than or equal to 2.5 and a mean PaO2/FiO2 ratio of 94 were managed in this manner. The mean maximum PaCO2 was 62 mmHg, the highest being 129 mmHg. The hospital mortality was significantly lower than that predicted by Apache II (16% vs. 39.6%, chi 2 = 11.64, p less than 0.001). Only one death was due to respiratory failure, caused by pneumocystis pneumonia. 10 patients had a "ventilator score" greater than 80, which has previously predicted 100% mortality from respiratory failure. Only 2 died, neither from respiratory failure. There was no significant difference in lung injury score, ventilator score, PaO2/FiO2 or maximum PaCO2 between survivors and non-survivors. We suggest that this ventilatory management may substantially reduce mortality in ARDS, particularly from respiratory failure.

Blood Gas Analysis↗

Trends in coronary heart disease mortality and morbidity in Auckland, New Zealand, 1974-1986.

Routine mortality statistics show that coronary heart disease (CHD) death rates have declined consistently in Auckland men since 1968; in women, death rates declined between 1968 and 1986 but since 1981 there may have been a reduction in the rate of decline. Data from CHD registers conducted in Auckland, New Zealand in 1974, 1981, and since 1983 as part of the WHO MONICA Project, have been used to investigate the validity and reasons for the decline in the age group 35-64 years. In Auckland age-standardized sudden coronary death rates in men declined by approximately 2% per year between 1974 and 1986; there was no apparent decline in women. There was also an indication of a decline in age-standardized definite myocardial infarction rates but again only in men; 28 day case fatality in patients with a definite myocardial infarction has not changed significantly in the period 1981-1986. These results validate the mortality trends based on death certificates and in particular the differing recent trends in men and women. The decline in CHD mortality in men without a concomitant change in case fatality and the lack of recent decline in women, suggest that changes in the natural history of the disease rather than treatment are responsible for the mortality trends. Since disease events are rare in absolute numbers, long-term monitoring of coronary heart disease in large population groups will be necessary to usefully study disease trends, particularly in women.

Adult↗

Myocardial infarction is inversely associated with plasma 25-hydroxyvitamin D3 levels: a community-based study.

The relation between the plasma level of 25-hydroxyvitamin D3, the main metabolite of sun-induced vitamin D, and myocardial infarction (MI) was investigated in a community-based case-control study. Some 179 MI patients presenting to hospital within 12 hours of the onset of symptoms were individually matched with controls by age, sex and date of blood collection. MI patients had significantly lower mean 25-hydroxyvitamin D3 levels than controls (32.0 versus 35.5 nmol/L; p = 0.017), with the case-control differences being greatest in winter and spring. The relative risk of MI for subjects with 25-hydroxyvitamin D3 levels equal to or above the median was 0.43 (95% confidence limits = 0.27, 0.69) compared to subjects below the median. The decrease in MI risk associated with raised vitamin D3 levels was observed in all seasons. These results provide support for the hypothesis that increased exposure to sunlight is protective against coronary heart disease.

Adult↗

Decreased blood selenium and risk of myocardial infarction.

The relationship between whole blood selenium levels and risk of acute myocardial infarction was investigated in a community-based control study in Auckland, New Zealand. A pilot study in 14 patients admitted to hospital within 4 hours of onset of symptoms demonstrated that selenium levels were stable in the first 16 hours after admission for an acute myocardial infarction. Some 252 cases (199 men, 53 women) presenting to hospital within 20 hours of onset of acute myocardial infarction were compared with 838 controls (500 men, 338 women), group-matched for age and sex. Myocardial infarction patients had significantly lower mean selenium levels: 82.8 and 87.9 micrograms/l in male cases and controls (p = 0.003) and 82.1 and 88.5 micrograms/l in female cases and controls (p = 0.02) respectively. The relative risks of myocardial infarction in participants with selenium levels below the median level (85 micrograms/l) in comparison with participants above the median were 1.6 (95% CL 1.1-2.2) and 1.7 (95% CL 0.9-3.5) in men and women respectively. The effects of a low selenium level on risk of myocardial infarction were confined to cigarette smokers. These results suggest the hypothesis that a decreased blood selenium in the presence of cigarette smoking is a risk factor for coronary heart disease.

Adult↗