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Biomedical subjects

A J Campbell

Publications and source records attributed to A J Campbell.

At least 19 recordsLinked to original sources
PubMed1992

Measuring care and dependency of elderly people in residential homes: an unreliable exercise.

OBJECTIVES: to determine the correlation between a scale measuring the amount of care required by people in rest homes and two scales, the Booth scale and the composite scale which measure dependency. To examine the scales for retest reliability. SUBJECTS: one hundred and twenty-five people aged 47 to 98 years, median age 84 years, living in seven rest homes in Dunedin. METHOD: subjects were assessed using the care, Booth and composite scales and the assessment repeated after four weeks. RESULTS: the care scale test-retest reliability based on rank order correlates was 0.86. For the physical care items retest reliability was high but supervision and the management of behavioural problems showed poor retest reliability. Correlation between the care scale and the two dependency scales was only moderate (composite scale 0.64, Booth scale 0.55). Behavioural problems and the time for supervision were assessed on the care scale only and it was these components which accounted for most of the poor correlation between the care and dependency scales. CONCLUSION: the time required for the management of behavioural problems and supervision for some people in rest homes was considerable. Measurement of this was difficult and made assessment of individual residents in homes unreliable.

Activities of Daily Living↗
PubMed1992

Pharmacokinetics of pirmenol in young and elderly subjects.

The steady state pharmacokinetics of pirmenol was compared in twelve healthy young (aged 18 to 45 y) and 11 elderly subjects (over 65 y) subjects given pirmenol HCl 100 mg every 12 h for a total of 14 doses. In addition, the single-dose pharmacokinetics of pirmenol was determined following a 100 mg oral dose in the young subject group for comparison with the results of repeated administration. In the young subjects, the mean single-dose and steady-state CLR of pirmenol were similar; however, Ae was 29% higher and CL/f was 22% lower at steady state than after the single dose. Steady-state (fourteenth dose) Cmin, Cmax, tmax, lambda z, Ae, CL/f, CLR and V values were similar in the young and elderly subjects. Based on pharmacokinetic considerations, the dosage of pirmenol is unlikely to differ in young and elderly subjects.

Adult↗
PubMed1992

Effect of nutritional status on organic anion clearance by the swine liver.

Hepatic dysfunction follows a wide range of insults. Impaired excretion of organic dyes such as bilirubin often occurs before other obvious clinical defects in metabolic processes. Indocyanine green (ICG) is excreted through pathways similar to those of bilirubin. To determine the effectiveness of ICG as a marker of hepatic dysfunction related to clinical malnutrition, pigs received 5 mg/kg ICG with simultaneous sampling from the hepatic vein, pulmonary artery, and aorta over 3 hours. Group I remained well nourished, group II was fasted to a weight loss equal to 20% of initial body weight, and group III was fasted to a 20% weight loss and then refed until the animals regained their initial weight. Both systemic and intrinsic hepatic clearance were depressed significantly with fasting but returned above baseline after refeeding. No significant difference appeared between systemic and intrinsic hepatic clearance. Extraction ratios were low in all groups. In outbred swine, ICG clearance reflects the function of hepatic organic anion excretion in vivo, and venous sampling reflects intrinsic hepatic clearance. The impairment of the carrier-mediated transport system is reversible with refeeding.

Animal Feed↗
PubMed1991

Lactose malabsorption and calcium intake as risk factors for osteoporosis in elderly New Zealand women.

OBJECTS: to evaluate the prevalence of lactose malabsorption and to assess dietary calcium intake, in elderly New Zealand women with hip fractures, in age matched case controls without hip fractures drawn from general practice, and in healthy young women. METHODS: lactose malabsorption was assessed by measuring breath hydrogen after a 50 g oral lactose tolerance test. Dietary calcium was estimated from a food frequency questionnaire. RESULTS: the elderly fracture cases (n = 15), and their elderly controls (n = 16), showed a similar (60% and 63% respectively), but significantly higher prevalence (p less than 0.001), of lactose malabsorption than young women (12%, n = 50). Dietary calcium intake was similar in lactose absorbers and malabsorbers. CONCLUSIONS: malabsorption of lactose occurs commonly in elderly New Zealand women but is scarce in young adults. A high prevalence of lactose malabsorption may be a risk factor for exacerbation of type II osteoporosis in the elderly.

Adolescent↗
PubMed1991

Informed consent for cardiopulmonary resuscitation in elderly patients.

OBJECT: to determine if a semistructured interview would enable elderly patients to give adequately informed consent for cardiopulmonary resuscitation (CPR). METHOD: one hundred consecutive patients admitted to Wakari assessment and rehabilitation unit for the elderly, who satisfied study criteria, were randomly allocated to receive a detailed discussion on CPR or to act as controls. Subsequently knowledge about CPR was tested in both groups. RESULTS: of the 49 study subjects, 27 (55%) wished to have CPR in the event of a cardiac arrest. After the interview knowledge about the CPR was significantly better in the study group than the controls, but there was still a lack of appreciation of the possible complications and an overly optimistic view of the likely outcome. CONCLUSIONS: careful explanation of the procedures involved in CPR does increase knowledge and assist in making an informed decision. However, the decision may still be based on poor understanding of the likely outcome and possible complications.

Aged↗
PubMed1991

Changes in red cell shape in healthy elderly subjects taking low dose fish oil: pilot study.

OBJECTS: to investigate the effects of low dose fish oil on red cell shape and blood pressure in healthy elderly subjects during a 16 week treatment and an eight week follow-up. METHODS: red cell shape analysis by scanning electron microscopy with data analysis by repeated measures analysis of variance. RESULTS: in the preoil blood samples the percentage of cells with surface changes was much higher than that of younger healthy subjects (24.0% vs 14.4%). While taking fish oil the percentage of cells with surface changes declined to a minimum at the end of the eighth week, steadily increased during the next eight weeks then declined during the eight week follow up. Mean blood pressures were not altered by the fish oil although that of five subjects taking different types of antihypertensive drugs tended to show greater fall in blood pressure than those not on drugs. CONCLUSION: that dietary supplementation with low dose fish oil was associated with changes in red cell shape. The observed changes are currently inexplicable.

Aged↗
PubMed1991

Knowledgeable non-compliance with prescribed drugs in elderly subjects--a study with particular reference to non-steroidal anti-inflammatory and antidepressant drugs.

Knowledgeable non-compliance with non-steroidal anti-inflammatory drugs (NSAIDs) and antidepressant drugs was investigated in a community-based sample of elderly people. Everyone 70 years and over living in a defined area and taking one of the above drugs, and at least one other prophylactic or symptomatic drug, was studied. Non-steroidal anti-inflammatory drugs and antidepressant drugs are commonly regarded as symptomatic only and knowledgeable non-compliance is consequently high. They are also regarded as less important than drugs which produce no immediate relief of symptoms but which the patient recognizes as needing to be taken regularly to maintain health. In our study, compliance with non-steroidal anti-inflammatory drugs and antidepressant drugs was highest in those who were compliant with a prophylactic drug and were also taking a symptomatic drug. The greater the number of tablets the patient was taking the more likely he or she was to be compliant with the NSAID. Compliance with NSAIDs and antidepressant drugs requires clear label instructions and the patient knowing the purpose of the medication.

Aged↗
PubMed1991

Subcutaneous fluid administration in elderly subjects: validation of an under-used technique.

In a crossover study in six volunteers over the age of 65, absorption of 500 mL of normal saline given subcutaneously was compared with that given intravenously. Tritiated water and technetium pertechnetate were used as water tracers. Tritium radioisotope levels in the blood increased in a smooth curve during subcutaneous infusion, reaching equilibrium levels within 60 minutes. The area under the curve after subcutaneous infusion was almost identical to that after intravenous infusion in all subjects. Radioactivity could not be demonstrated at the subcutaneous site 1 hour after completion of the infusion. Subcutaneous infusion is an effective method of giving fluid to elderly people and deserves more widespread use.

Aged↗
PubMed1991

Diagnostic accuracy. The effects of multiple aetiology and the degradation of information in old age.

We propose two causes of diagnostic inaccuracy in elderly patients: multiple aetiology and the degradation of clinical information. A single clinical event in an elderly person is often the result of several small and sometimes changing aetiological factors. Multiple aetiology is particularly common in the elderly because of impairment in a number of organ systems, loss of physiological reserve, and the increased exposure to stresses. Diagnostic errors arise first because clinicians tend to look for single, large and static explanations for clinical events, and second because the errors inherent in each step in diagnosis compound when there are multiple aetiological factors. These inherent errors are also greater in old people because of difficulties in a variety of measurements. We present a numerical analysis of this which suggests that failing to make a diagnosis when the disease is present or making a diagnosis when a disease is not present is likely to occur twice as often in old as in younger patients. We suggest that these problems can be countered by being aware of the phenomenon of multiple aetiology and the diagnostic traps arising from it, and by employing the most accurate and discriminating methods when investigating elderly people. These diagnostic difficulties mean that, when they are ill and require treatment, old people need prompt access to the best of investigative and therapeutic facilities.

Aged↗
PubMed1990

Enhanced elimination of piroxicam by administration of activated charcoal or cholestyramine.

This study has compared the effect of repeated administration of charcoal and cholestyramine on the elimination of piroxicam. Eight young adults were given piroxicam as a single dose of 20 mg, on 3 separate occasions. On one of the occasions charcoal was also given. On another occasion cholestyramine was also administered. The mean elimination half-life after piroxicam alone was 53.1 h. This was reduced to 40.0 h by charcoal administration and to 29.6 h after administration of cholestyramine. In the second phase of the study 7 elderly subjects received piroxicam 20 mg for 14 days on two occasions. Cholestyramine administration at the end of one of the periods reduced the mean elimination half-life of piroxicam from 52.3 h to 27.3 h.

Administration, Oral↗
PubMed1990

Examination by logistic regression modelling of the variables which increase the relative risk of elderly women falling compared to elderly men.

In a community based, prospective study to determine risk factors for falls, 465 women and 296 men 70 years and over were followed for 1 year and 507 falls were documented. A greater proportion of women (32.7%) than men (23.0%) experienced at least one fall in which there was no or minimal external contribution. Using unconditional logistic regression models we investigated the effect of physical and sociological variables on the sex difference in fall rate. Controlling for the variables age, use of psychotropic drugs, inability to rise from a chair without using arms, going outdoors less than daily and living alone decreased the relative risk of women falling compared to men from 2.02 (95% CI, 1.40-2.92) to 1.55 (95% CI 1.04-2.31). Some of the increased risk of falling associated with being a women was able to be explained and is potentially correctable. But even after controlling for the physical and social variables which we had assessed, women compared to men still had a significantly increased relative risk of falling.

Accidental Falls↗
PubMed1990

Anthropometric measurements as predictors of mortality in a community population aged 70 years and over.

Corrected arm muscle area (CAMA), triceps skin-fold thickness (TSF) and body mass index (BMI) were measured in a community sample of 758 people who were then followed for 40-46 months. Percentile values were calculated for each sex in 5-year age groups. The relative risk of death of those in the upper and lower percentiles was compared with those between the 10th and 90th percentiles, controlling for age and sex. Subjects below the 5th percentile for CAMA, TSF and BMI and between the 5th and 10th percentile for CAMA had a significantly increased risk of death. There was no increased risk of death in those subjects above the 90th percentile in any measurement. In the logistic regression model, both low CAMA and low TSF were associated with a significantly increased risk of subsequent mortality. Poor nutritional state shown by low muscle bulk and fat stores was an important predictor of mortality, but obesity had no adverse effect on survival.

Aged↗
PubMed1990

Circumstances and consequences of falls experienced by a community population 70 years and over during a prospective study.

A sample of 761 subjects 70 years and over was drawn from general-practice records of a rural township. Each subject was assessed and followed for 1 year to determine the incidence of and factors related to falls. The fall rate (number of falls per 100 person-years) increased from 47 for those aged 70-74 years to 121 for those 80 years and over. There was no sex difference in fall rate but men were more likely than women to fall outside and at greater levels of activity. Twenty per cent of falls were associated with trips and slips but we found no evidence that inspection of homes and installation of safety features would have decreased the fall rate. Ten per cent of falls resulted in significant injury. Men who fell had an increased subsequent risk of death compared with those who did not fall (relative risk 3.2, 95% CI 1.7-6.0). Subsequent mortality was increased among women who fell but not to significant levels (relative risk 1.6, 95% CI 0.9-2.7).

Accidental Falls↗
PubMed1979

The atypical velocity response by pyruvate carboxylase to increasing concentrations of acetyl-coenzyme A.

An investigation was made of the interaction of pyruvate carboxylase with its allosteric effector, acetyl-CoA, and the velocity profile of the deacylation of acetyl-CoA as a function of acetyl-CoA concentration indicated that this ligand does not bind to this enzyme in a positive homotropic co-operative manner. An examination was therefore made of the factors that contribute to the sigmoidicity of the rate curves obtained for pyruvate carboxylation with various concentrations of acetyl-CoA. Hill coefficients for acetyl-CoA obtained with both sheep and chicken liver pyruvate carboxylases were found to be dependent on the fixed pyruvate concentration used in the assay solution. Thus, by varying the acetyl-CoA concentration, the degree of saturation of the enzyme by pyruvate was also changed. A further consequence of non-saturating concentrations of pyruvate was that the non-productive hydrolysis of the enzyme- carboxybiotin complex increased, resulting in an under-estimate of the reaction velocity measured by oxaloacetate formation. Another factor contributing to the sigmoidicity is that, at non-saturating concentrations of acetyl-CoA, the enzyme undergoes inactivation upon dilution to low protein concentrations, again resulting in an under-estimate of the reaction velocity. Under conditions where none of the above factors was operating and the only effect of varying acetyl-CoA concentrations was to alter the proportion of the enzyme catalysing the carboxylation reaction at acetyl-CoA-dependent and -independent rates, the sigmoidicity of the acetyl-CoA velocity profile was completely eliminated.

Acetyl Coenzyme A↗
PubMed1977

Square pegs in round holes: a study of residents in long-term institutions in London, Ont.

A large random sample of people in the long-term institutions (homes for the aged, nursing homes and continuing care hospitals) of London, Ont. was studied to assess the suitability of these people, according to physical and mental status, for the institution in which each resided. The results indicated a relative need for beds in homes for the aged and nursing homes. A high proportion (29% to 54%) of people in the three types of institutions were unsuitably placed. Greater flexibility is needed in institutional arrangements, and institutions should be examined for their potential to provide support in maintaining the elderly at home. The findings of this study add some weight to the arguments of those calling for more and better home care programs for the disabled.

Activities of Daily Living↗