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Biomedical subjects

A L Stewart

Publications and source records attributed to A L Stewart.

At least 73 records · Page 4Linked to original sources
PubMed1994

Long-term functioning and well-being outcomes associated with physical activity and exercise in patients with chronic conditions in the Medical Outcomes Study.

This study was carried out to determine whether levels of physical activity of patients with various chronic diseases are associated with subsequent functioning and well-being. It was an observational 2-year longitudinal design. The setting was offices of medical and mental health practices within health maintenance organizations, large multispecialty groups, and solo practices or small single-specialty group practices in three U.S. cities. Included in the study were 1758 adult patients with one or more of the following: diabetes, hypertension, congestive heart failure, recent myocardial infarction, depressive symptoms, or current depressive disorder. Outcome measures included physical, role, and functioning; energy/fatigue; pain intensity; sleep problems; depressed affect, anxiety, positive affect, and overall psychological distress/well-being; health distress; and current health perceptions. Cross-sectional (base-line), 2-year endpoint, and change score relationships were evaluated between baseline levels of physical activity and each outcome, controlling for chronic conditions, comorbidity, smoking, alcohol use, overweight, self-reported adherence, and other patient and study characteristics. Higher baseline levels of exercise were uniquely associated with better functioning and well-being at baseline and 2 years later for some measures. The magnitude of the differences varied by disease group, but tended to be between 0.17 and 0.39 of the baseline SD. Greater levels of exercise are associated with feeling and functioning better for patients with chronic conditions over a 2-year period, suggesting that this is a fruitful area for further study using controlled interventions.

Activities of Daily Living↗
PubMed1994

A phase II, multicentre, UK study of vinorelbine in advanced breast cancer.

Thirty-four evaluable patients were treated with vinorelbine, a novel, semisynthetic vinca alkaloid, as first-line chemotherapy for advanced breast cancer. They received vinorelbine 25 mg m-2 i.v. given weekly for a maximum of 16 cycles. Two patients achieved a complete remission and 15 a partial remission, giving a response rate of 17/34 (50%; 95% CI of 34-66%); median response duration was 5.8 months. The median progression-free interval was 4.4 months and median survival 9.9 months. Treatment was generally well tolerated. Fatigue was the most common side-effect. The main reason for dose adjustments was myelosuppression; 68% of patients had WHO grade 3 or 4 neutropenia and there was one death attributed to neutropenic sepsis. Nausea/vomiting and neuropathy were mild and alopecia was uncommon. This study confirms vinorelbine as a highly active, well-tolerated agent in advanced breast cancer worthy of evaluation in combination chemotherapy regimens.

Adult↗
PubMed1994

Relation between neurodevelopmental status of very preterm infants at one and eight years.

The relation between neurodevelopmental status at one and eight years of age was investigated in a cohort of 207 infants born between 1979 and 1982 at < 33 weeks of gestation. The probability of a major disabling impairment at eight years was only 1 per cent among 164 children with normal neurodevelopment at one year, but 56 per cent for the 43 impaired children and 92 per cent for the 23 of these who had major disabling impairments. Close correspondence was found between the type of major impairment diagnosed at one and eight years. Neurodevelopmental status at one year also predicted the need for extra educational provision by eight years, with probabilities of 9 per cent for children without impairment at one year, 56 per cent for impaired children and 87 per cent for those with major impairments. Similarly, neurodevelopmental status predicted an IQ of more than 2 SD below the mean (< 70), with probabilities of 0, 30 per cent and 48 per cent, respectively.

Child↗
PubMed1994

Development of a physical performance and mobility examination.

OBJECTIVE: To develop and validate the Physical Performance and Mobility Examination (PPME), an observer-administered, performance-based instrument assessing 6 domains of physical functioning and mobility for hospitalized elderly. DESIGN: Development of a pass-fail and 3-level scoring system and training manuals for the PPME instrument for use in both clinical and research settings. Two patient samples were used to assess construct validity and interrater reliability of the PPME. A third sample was selected to assess the test-retest reliability of the instrument. SETTING/PATIENTS: (1) 146 subjects > or = 65 years of age with impaired mobility admitted to Medical Units of Stanford University Hospital. (2) 352 subjects > or = 65 admitted to acute Medical and Surgical Services of the Palo Alto VA Medical Center. Patient samples were obtained during hospitalization and followed until 3 months post-discharge. To study test-retest reliability, 50 additional patients, whose clinical condition was stable, were selected from both settings. METHODS: An expert panel selected 6 mobility tasks integral to daily life: bed mobility, transfer skills, multiple stands from chair, standing balance, step-up, and ambulation. Tasks were piloted with frail hospitalized subjects for appropriateness and safety. Test-retest and interrater reliability and construct validity were evaluated. Construct validity was tested using the Folstein Mini-Mental State Examination, Activities of Daily Living (ADL), Instrumental Activities of Daily Living (IADL), Geriatric Depression Scale, and modified Medical Outcomes Study Measure of Physical Functioning (MOS-PFR). Two scoring schema were developed for each task: (1) dichotomous pass-fail and (2) 3-level high pass, low pass, and fail. A summary scale was developed for each method of scoring. MAIN RESULTS: High interrater reliability and intrarater reliability were demonstrated for individual tasks. The mean percent agreement (interrater) for each pass/fail task ranged from 96 to 100% and from 90 to 100% for the 3 pairs of raters for each task using the 3-level scoring. Kappas for individual pairs of raters ranged from .80 to 1.0 for pass-fail scoring and from .75 to 1.0 for 3-level scoring (all P < 0.01). Intraclass correlation coefficients for 3-level scoring by pairs of raters ranged from .66 to 1.0. For summary scales, the mean intraclass correlation was .99 for both scoring schema. Test-retest reliability for summary scales using kappa coefficients was .99 for both pass-fail and 3-level scoring, and .99 and .98, respectively, using Pearson Product Moment Correlation. Correlations of PPME with other instruments (construct validity) suggest that the PPME adds a unique dimension of mobility beyond that measured by self-reported ADLS and physical functioning, and it is not greatly influenced by mood or mental status (r = 0.70 (ADL), r = 0.43 (IADL), r = 0.36 (MMSE), r = 0.71 (MOS-PFR), r = 0.23 (GDS)). The 3-level summary scale was sensitive to the variability in the patient population and exhibited neither ceiling nor floor effects. CONCLUSIONS: The PPME is a reliable and valid performance-based instrument measuring physical functioning and mobility in hospitalized and frail elderly.

Activities of Daily Living↗
PubMed1993

Do depressed patients in different treatment settings have different levels of well-being and functioning?

Differences in the functioning and well-being of adult patients with current or past depressive disorder who visited clinicians of different specialties in health maintenance organizations, solo practices, or large multispecialty group practices were examined. For patients in different systems, there were no significant differences in functioning and well-being across 12 domains tested. Patients of mental health specialists had worse mental health and more limitations in social activities, whereas patients of medical clinicians had worse physical functioning, more pain, more physical/psychophysiologic symptoms, and worse health perceptions. Thus, each system of care had depressed patients with a similar functioning and well-being "burden" but specialty sectors had patients with slightly different functioning and well-being profiles, probably reflecting patient selection of type of provider.

Adaptation, Psychological↗
PubMed1993

Endurance exercise and health-related quality of life in 50-65 year-old adults.

Health-related quality of life was evaluated in relation to endurance exercise over the prior year for 194 previously sedentary, healthy men and women aged 50-65 using a posttest-only design. Three exercise regimens were studied that varied in format (class-based vs home-based) and intensity (higher vs lower). In all regimens, subjects who participated more had better physical health 12 months after program initiation (p values < .05); no differences were observed in general psychological well-being. Extent of participation, rather than format or intensity of exercise, was associated with better physical health in this population.

Aged↗
PubMed1993

Relation between ultrasound appearance of the brain of very preterm infants and neurodevelopmental impairment at eight years.

The relation between the ultrasound appearance of the brain and neurodevelopmental outcome at eight years of age was investigated in 206 infants born between 1979 and 1982 at < 33 weeks gestation (600 to 2500g birthweights). Only 4 per cent of the 112 infants with normal scans at discharge from the neonatal unit developed major, disabling impairment. No significant adverse effect of uncomplicated periventricular haemorrhage was detected. The probability of a major impairment in infants with ventricular dilatation or hydrocephalus was 27 per cent, and 69 per cent in those with cerebral atrophy. 44 per cent of the children demonstrated significant differences in their cognitive processing skills, which appeared capable of affecting learning and may possibly have been caused by undetected hypoxic-ischaemic damage to callosal fibres.

Achievement↗
PubMed1992

Primary malignant lymphoma of the thyroid: a clinicopathological analysis.

A retrospective analysis of 70 patients with primary malignant lymphoma of the thyroid treated at this institute between 1965-1983 has been conducted. The clinicopathological features and prognostic factors have been studied. The mean age was 67.5 years and there was a marked female:male ratio of 8:1. A total of 32 (45.7%) Stage IE and 38 (54.3%) Stage IIE patients were identified. In 64 cases histological material was reviewed and classified employing the Kiel classification. All the tumors were of B cell lineage and the majority were follicle center cell type. A biopsy only was performed in 27 patients, lobectomy in 11 patients, subtotal thyroidectomy in 27 and macroscopic thyroidectomy in 5 patients. All patients were treated with radiotherapy. The overall 5-year survival was 42%, with 63% for Stage IE and 27% for Stage IIE. The corrected overall 5-year survival was 49% with 68% for Stage IE and 36% for Stage IIE. The corresponding overall relapse free survival was 42% with 60% for Stage IE, and 31% for Stage IIE. Factors of prognostic significance for relapse and survival were stage, radiotherapy dose, stridor, retrosternal extension and fixation.

Adult↗
PubMed1992

Relation between cerebral oxidative metabolism following birth asphyxia, and neurodevelopmental outcome and brain growth at one year.

Studies of cerebral oxidative metabolism were carried out by phosphorous magnetic resonance spectroscopy during the first week of life in 52 infants with clinical and/or biochemical evidence of birth asphyxia. 15 infants died and the 37 survivors were assessed by a wide range of neurodevelopmental tests at one year of age. The minimum recorded values for cerebral phosphocreatine/inorganic phosphate concentration ratio (an index of oxidative metabolism) were related to outcome. The results showed a significant relation between the extent of derangement of oxidative metabolism and the severity of adverse outcomes, including death, neurodevelopmental impairment and reduced head growth.

Adenosine Triphosphate↗
PubMed1991

A space-variant differential operator for visual sensitivity.

All the elements of a Fourier analysis can be derived from the experiments of Graham and Robson on contrast sensitivity. Once their experiment is posed as an eigenvalue problem, a complete orthonormal set of eigenfunctions results from solving the associated differential equation. Neither sine and cosine nor Gabor functions result. Instead, the Hermite functions arise as the eigenfunctions of a space-variant differential operator used to model the contrast sensitivity of human observers. These functions, up to a constant, are their own Fourier transforms, and in principle can be used to exactly represent the Fourier transform of naturally occurring visual images.

Contrast Sensitivity↗
PubMed1991

The MOS social support survey.

This paper describes the development and evaluation of a brief, multidimensional, self-administered, social support survey that was developed for patients in the Medical Outcomes Study (MOS), a two-year study of patients with chronic conditions. This survey was designed to be comprehensive in terms of recent thinking about the various dimensions of social support. In addition, it was designed to be distinct from other related measures. We present a summary of the major conceptual issues considered when choosing items for the social support battery, describe the items, and present findings based on data from 2987 patients (ages 18 and older). Multitrait scaling analyses supported the dimensionality of four functional support scales (emotional/informational, tangible, affectionate, and positive social interaction) and the construction of an overall functional social support index. These support measures are distinct from structural measures of social support and from related health measures. They are reliable (all Alphas greater than 0.91), and are fairly stable over time. Selected construct validity hypotheses were supported.

Adult↗
PubMed1991

Effect of intervention on development of hip posture in very preterm babies.

Preterm babies are physiologically hypotonic, which causes their posture to be flattened when lying in the prone position. This flattened posture may persist beyond term. In a prospective, randomised, controlled, double blind trial of postural support carried out on 45 babies born at less than 33 weeks of gestation, we showed that infants positioned with specific hip support during the period of intensive care had significantly fewer features of flattened posture at the age equivalent to term.

Double-Blind Method↗
PubMed1991

The object-detection effect: configuration enhances perception.

Line drawings used by Weisstein and Harris (1974) are seen as box-like three-dimensional figures if the lines are arranged properly. A flat two-dimensional pattern is seen when these same lines are disarranged. A target line contained within the three-dimensional figure is identified more readily than is the same line contained within a two-dimensional figure. This finding was extended in the present experiments: The three-dimensional stimulus was detected more quickly than the two-dimensional stimulus, under conditions of visual backward masking. Three-dimensional stimuli were also classified more quickly than two-dimensional stimuli. Just as with the face-detection effect and the word-detection effect, object detection can be affected by the form of the visual stimulus.

Adult↗