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Biomedical subjects

B J Stewart

Publications and source records attributed to B J Stewart.

At least 37 records · Page 2Linked to original sources
PubMed1994

Enrichment processes in family caregiving to frail elders.

Interview and observational data obtained from caregiver-care recipient dyads were analyzed in developing a theory of enrichment that explains how some families use pleasurable or meaningful experiences in their caregiving to frail elders. The personal history and frailty trajectory of both caregiver and care recipient, the quality of the dyadic relationship, and the caregiving situation are antecedents to enrichment processes. Core elements influencing the nature of enriching events include acquiring symbolic meaning, performing activity, and fine tuning. Categories of enrichment events are customary routines and innovative routine breakers. Consequences of enrichment are relationship and identity sustenance for both caregiver and care recipient, comfort for the care recipient, and rewards of meaning for the caregiver.

Adult↗
PubMed1994

Family caregivers of post-hospitalized older persons and persons receiving hospice: similarities and differences.

The study reported here explored similarities and differences between 103 family caregivers of older persons who had been discharged from the hospital and 70 caregivers of terminally ill older persons receiving hospice care. Caregiving variables were selected for examination based on role theory. Major findings include: hospice caregivers provided significantly more personal care and medically related tasks, significantly fewer transportation tasks, and worried less than the post-hospitalized sample. Otherwise, the two groups were strikingly similar. Similar patterns of correlations for the two groups were also found.

Aftercare↗
PubMed1994

Effect of contraceptive steroid and enalapril treatment of systolic blood pressure and plasma renin-angiotensin in the rat.

Previous work has demonstrated contraceptive steroid-induced hypertension in rats. Here, we examined the relationship between steroid-induced hypertension and components of the renin-angiotensin system. Female Sprague-Dawley rats were injected s.c. with 0.2 micrograms ethynyloestradiol, 2.0 micrograms levonorgestrel, a combination of both or vehicle, six days per week. A second group of rats received 2.0 micrograms enalapril maleate, enalapril plus ethynyloestradiol or levonorgestrel, or vehicle. Systolic blood pressure increased with both ethynyloestradiol. (6 weeks, +17 mmHg; 12 weeks, +32 mmHg) and levonorgestrel (6 weeks, +24 mmHg) treatment. This effect of levonorgestrel was attenuated by co-administration of enalapril, which also reversed the hypertension seen with ethynyloestradiol. Ethynyloestradiol, but not levonorgestrel treatment caused a significant increase in plasma renin concentration, plasma renin activity, and plasma angiotensin II at both 6 and 12 weeks. Plasma renin substrate was increased by ethynyloestradiol at 3, 6 and 12 weeks, prior to the observed increase in systolic blood pressure. Combined steroid treatment had less pronounced effects. Enalapril alone or in combination with ethynyloestradiol decreased plasma renin concentration, activity and angiotensin II, and in combination with levonorgestrel decreased plasma renin concentration, substrate and activity (6 weeks only) but not angiotensin II. The data indicate a positive relationship between hypertension and the renin-angiotensin system with ethynyloestradiol, but not levonorgestrel treatment in rats.

Angiotensin II↗
PubMed1994

Establishing partnerships with family caregivers. Local and cosmopolitan knowledge.

1. The concepts of local and cosmopolitan knowledge may be used by gerontological nurses in creating partnerships with family caregivers to frail older people. 2. Local knowledge is the understanding and skills that the family brings to the caregiving situation; cosmopolitan knowledge is the understanding and skills that the gerontological nurse brings to the situation. 3. Four nursing interventions are guided by the conceptualization of local and cosmopolitan knowledge: acknowledging and affirming local knowledge when it is adequate; developing or enhancing local knowledge when it is inadequate; assisting family caregivers to apply local knowledge to problem solving; and blending local and cosmopolitan knowledge.

Aged↗
PubMed1993

Nursing intervention studies require outcome measures that are sensitive to change: Part Two.

Ohis article is the second and concluding part of a discussion of the importance of sensitivity to change in selecting an outcome measure for a study evaluating a nursing intervention. In Part One of the discussion, (Stewart & Archbold, 1992) the relative lack of attention to measurement sensitivity in the nursing and measurement literature was described. Three factors to consider in selecting an outcome measure for an intervention study were reviewed: the conceptual link between the intervention and the outcome variable, the extent to which the outcome variable is amenable to change, and content validity. In Part Two, four additional factors are discussed: construct validity, distribution of scores on the outcome measure, reliability, and correlational stability over time.

Humans↗
PubMed1993

Enterotoxigenic bacteria in the sudden infant death syndrome.

Faecal samples from 123 infants who died with sudden infant death syndrome (SIDS) and from a comparative group of 52 age-matched babies were analysed for toxigenic bacteria and their toxins. Serum samples from the SIDS infants were also analysed for these toxins. A significantly higher proportion of toxigenic bacteria and their toxins were found in faecal samples of SIDS babies than in samples from the comparative group. These toxins were also found in serum from the SIDS babies. Clostridium perfringens was found in 54 (45.4%) of 119 SIDS cases compared with 10 (19.6%) of 51 healthy babies (chi 2 = 10.1, p < 0.01); C. difficile in 33 (27.7%) of 119 SIDS cases compared with 8 (14.8%) of 54 healthy babies (chi 2 = 3.43ns, p < 0.1); Staphylococcus aureus in 12 (27.3%; 66.7% enterotoxigenic) of 44 SIDS cases compared with 12 (85.7%; non-enterotoxigenic) of 14 healthy babies (chi 2 = 14.9, p < 0.001); C. botulinum in 6 (5.0%) of 120 SIDS cases compared with 0 of 53 healthy babies (chi 2 = 2.74, p < 0.1). Campylobacter jejuni, Yersinia enterocolitica, Vibrio parahaemolyticus, salmonellae and Bacillus cereus were not detected. Heat-labile toxin, lethal to mice (HLML) was found in 32 (27.1%) of 118 SIDS faecal samples compared with 5 (10.6%) of 47 healthy babies (chi 2 = 5.24, p < 0.05); cytotoxins in 38 (30.9%) of 123 SIDS faecal samples compared with 0 of 21 of healthy babies (chi 2 = 8.8, p < 0.01) and 24 (27.6%) of 87 SIDS serum samples. C. perfringens enterotoxin was detected in 33 (34.4%) of 96 SIDS faecal extracts compared with 0 of 23 of healthy babies (chi 2 = 10.94, p < 0.001), and in 27 (24.5%) of 110 SIDS serum samples. C. perfringens alpha-toxin (presumptive) was detected in 14 (17.5%) of 80 SIDS faecal extracts compared with 0 of 17 from healthy babies (chi 2 = 3.5ns, p congruent to 0.05) and in 2 (2.3%) of 87 SIDS serum samples. C. difficile toxin was detected in four SIDS faecal samples and two serum samples. C. botulinum toxin was detected in only one of 120 SIDS faecal samples compared with none of 49 from healthy babies. Staphylococcal enterotoxins were detected in 8 (19.5%) of 41 SIDS faecal samples compared with 0 of 19 from healthy babies (chi 2 = 4.278, p < 0.05), and in 4 (10.8%) of 37 SIDS serum samples.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1993

Characterization of mutations in divIB of Bacillus subtilis and cellular localization of the DivIB protein.

Four temperature-sensitive mutations in the divIB gene of Bacillus subtilis have been localized to the region corresponding to the C-terminal half of the 263-residue DivIB protein. Antiserum was raised to the 80% C-terminal portion lying on one side of a putative transmembrane (hydrophobic) segment, and used to examine aspects of the nature and localization of the DivIB protein in the cell. A single DivIB species of a size equal to the full-length protein encoded by the divIB gene was detected in wild-type cells. Cell fractionation studies established that DivIB is associated preferentially with the cell envelope (membrane plus cell wall), with approximately 50% being released into solution upon treatment of cells with lysozyme under conditions that yield protoplasts. Of the remaining 50%, approximately half remained firmly associated with the membrane fraction. On the basis of the 'positive-inside rule' of von Heijne (1986) it is suggested that the topology of membrane-bound DivIB is such that the long C-terminal portion is directed to the outside and the smaller N-terminal portion to the inside of the cell. DivIB in protoplasts was rapidly degraded by proteinase K under conditions where there was no general proteolysis of the cytoplasmic proteins. This is consistent with its absence from the cytoplasm, and with the predicted membrane topology. Septum positioning in a divIB null mutant, which grows as filaments at temperatures of 30 degrees C and below, was found to be normal. It appears that DivIB is needed for achieving the appropriate rate of initiation of septum formation at normal division sites. It is proposed that the C-terminal portion of DivIB, localized on the exterior surface of the membrane and in juxtaposition to the peptidoglycan, normally interacts with another protein (or proteins) to initiate septum formation.

Amino Acid Sequence↗
PubMed1993

Reports of sensorineural deafness after measles, mumps, and rubella immunisation.

There have been nine reports of sensorineural hearing loss after measles, mumps, and rubella (MMR) immunisation. In three cases the deafness was unrelated to MMR immunisation. In six cases the cause was unknown and MMR remained a possible aetiology. Any risk associated with attenuated viruses must be weighed against the risks of the natural diseases.

Child↗
PubMed1992

Nursing intervention studies require outcome measures that are sensitive to change: Part One.

In selecting an outcome measure for a study evaluating a nursing intervention, the criterion of sensitivity to change should predominate. Researchers commonly justify their choice of outcome measures for experiments based on such psychometric criteria as high internal consistency reliability and patterns of correlations reflecting convergent and discriminant validity. Although such criteria are appropriate for measures to assess individual differences, they are insufficient when the measures will be used for intervention studies. Researchers may need to develop new measures that are tailored for experimental studies if existing measures are valid mainly for the assessment of individual differences. In this first portion of a two-part article, three of seven factors to consider in selecting an outcome measure for an intervention study are outlined and recommendations for application of principles of reliability and validity in the context of sensitivity to change are given.

Humans↗
PubMed1990

Mutuality and preparedness as predictors of caregiver role strain.

Data from 78 older persons and their family caregivers were obtained at 6 weeks and 9 months after hospital discharge. Hierarchical multiple regression was used to determine whether mutuality and preparedness for caregiving were related to lower levels of caregiver role strain. The results indicated that, after controlling for five other variables commonly found to be related to caregiver role strain, mutuality and preparedness ameliorated some but not all aspects of role strain.

Adult↗
PubMed1990

Fatty acid pattern outcomes of a nutritional program for overweight and hyperlipidemic Australian men.

There is growing recognition of the value of changing tissue fatty acid patterns in their own right as coronary risk factors. To examine the effects of a conventional nutritional program on plasma triglyceride (TG), cholesterol ester, and phospholipid fatty acid patterns, a group of 20 hyperlipidemic men and a control group (n = 6) of normolipidemic men were followed for 6 months. As an index of change in energy balance in the hyperlipidemic men, body mass index decreased from 26.5 to 24.4 kg m-2 (an 8% decrease) at 6 months. Saturated fat intake fell from 46.7 to 25.3 g/day (a 46% decrease). Dietary polyunsaturated:saturated fat ratio (P:S) rose from 0.38 and to 0.70 (an 84% increase) at the 6-month review. Ethanol intake fell from 18 to 15 g/day (a 17% decrease). Changes in plasma fatty acid (FA) patterns were found in TG, cholesterol ester, and phospholipid fractions at the 6-week to 3-month period, and these changes were maintained at 6 months. Of the factors possibly contributory to plasma FA pattern change in these men, dietary FA intake underwent the greatest percentage shift and therefore probably makes an important contribution to the change. It was of interest that fatty acid patterns in plasma neutral lipids (triglyceride, cholesterol ester, and phospholipid) significantly predicted body mass index and serum total cholesterol, triglyceride, and high-density-lipoprotein cholesterol.

Adult↗
PubMed1988

A sensitive direct radioimmunoassay for assessing D-norgestrel levels in human plasma.

A direct radioimmunoassay was developed for assessing the levonorgestrel levels in human plasma without the need for heat, chromatographic or extraction pretreatment. D-norgestrel-3 (0-carboxymethyl)-oximino-BSA conjugate was used to raise antibodies having a low binding affinity towards other endogenous steroids. The rivanol-purified antiserum after dilution was used as the binding protein. The direct assay of levonorgestrel in human plasma was then compared to an extraction procedure. Lower intra-assay variability was shown by the direct assay when compared to the extraction method used at a sensitivity level of 0.15 nmol/L. The performance of the direct assay in quality control tests was more than favourable when compared with the extraction procedure. An examination of the effects of protein concentration on extraction efficiency was carried out together with an assessment of levonorgestrel levels in plasma in eight normal healthy women currently taking oral contraceptives and eight women who were not, at 0-24 h after the ingestion of 150 micrograms of D-NG and 30 micrograms of ethynyl oestradiol.

Adult↗
PubMed1988

Detection of neonatal hypoglycemia--a comparison of three reagent strips.

This article reports two studies that replicate previous investigations of the effectiveness of Chemstrip bG, Dextrostix and Visidex for making nursing assessments of hypoglycemia in the newborn. The article also describes a third study that combines results of the first two studies with results of previous studies in the literature in an attempt to improve the reliability and validity of the findings. In the first study, 102 blood samples were tested using either Chemstrip bG or Dextrostix and then compared with laboratory blood glucose levels. Because of the small number of hypoglycemic samples, a second study was devised in which six samples of cord blood were artificially titrated to known levels of glucose. In this study, Visidex as well as Chemstrip bG and Dextrostix were used. Eighty-five percent, 50 percent and 90.4 percent of the hypoglycemic samples were detected by Chemstrip bG, Dextrostix and Visidex, respectively. Data available in the literature from previous studies investigating the same question were then compiled and analyzed. The composite sample of 402 infants for Dextrostix and 484 for Chemstrip bG resulted in the finding that less than half of the hypoglycemic infants tested with Dextrostix were detected whereas Chemstrip bG detected 90 percent of them. The conclusion reached is that both Chemstrip bG and Visidex can be considered adequate screening techniques for nursing assessment of hypoglycemia in the newborn, while visually read Dextrostix is unacceptable in clinical practice.

Blood Glucose↗
PubMed1986

Changes in blood progesterone concentration during pregnancy in the lizard Tiliqua (Trachydosaurus) rugosa.

Progesterone concentrations during pregnancy were measured in the plasma of the viviparous lizard (scincid) Tiliqua (Trachydosaurus) rugosa, using a radioimmunoassay specific for progesterone. The length of gestation in this Australian lizard was 140-170 days. The average number of young was 2.8 and the mean neonatal weight 58 g (maternal body weight 500-700 g). The mean concentration of progesterone was greatest (7.2 nmol/l) during the second trimester of pregnancy; mean values during the first and third trimesters, and in non-pregnant females, were 1.8, 0.9 and 0.2 nmol/l respectively.

Animals↗
PubMed1985

Changes in blood flow distribution in equine lungs induced by anaesthesia.

The distribution of blood flow to the lungs was measured with labelled microspheres injected into horses before and during anaesthesia. Anaesthesia was induced with glycerol guaiacolate ether and ketamine, and maintained with the spontaneous breathing of halothane in oxygen. In a preliminary group of six horses, flow distribution was observed during anaesthesia in sternal, dorsal and right lateral recumbency. In two other groups, each of four horses, the flow distribution with time during either sternal or right lateral recumbency was observed. A small, constant proportion of the 15 micron diameter microspheres bypassed the lungs. No increase in shunting with anaesthesia was detected. Blood flow distributed predominantly cranioventrally in the conscious horse in concordance with the expected effects of hydrostatic forces within the lung. In the anaesthetized horse a stable distribution rapidly developed whereby the flow was directed preferentially caudodorsally and evenly divided between the left and right lungs regardless of whether the horse was on its back, side or sternum. We conclude that an unidentified factor overrides gravitational effects on perfusion in the anaesthetized horse. If under anaesthesia, ventilation were distributed according to gravity, hypoxia would arise from this disassociation of ventilation from perfusion. The hypoxia would be most intense in dorsal recumbency, and least intense in sternal recumbency. This was reflected in the degree of hypoxaemia observed. A small but significant change in flow distribution with the phase of the respiratory cycle was detected in the conscious, standing horse.

Anesthesia, General↗
PubMed1983

Resin-process methods for improved isolation of organisms from blood and other body fluids.

Two resin-based processes and conventional culturing methods were compared in isolating organisms from blood specimens of patients given antimicrobial agents. Of 20 patients whose specimens were found to contain clinically relevant organisms, one or both of the resin-process methods isolated organisms in eight after conventional culturing was unsuccessful. Conventional cultures were successful in five cases in which the resin-process methods did not work, and both resin-process and conventional culturing were successful in seven cases. In eight cases in which other body fluids were cultured, only a resin-process method was successful in four, although they are intended for use only with blood specimens. Data indicate that resin-process methods should be used along with conventional culturing methods when patients have already been given an antimicrobial. A review of the literature shows that the devices improve the recovery of organisms but does not establish that detection time is decreased.

Bacteria↗