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Biomedical subjects

J Elliot

Publications and source records attributed to J Elliot.

At least 19 recordsLinked to original sources
PubMed1999

Increased airway smooth muscle in sudden infant death syndrome.

The underlying pathophysiological mechanism behind death in the sudden infant death syndrome (SIDS) is uncertain. Although infants dying of SIDS frequently have a postmortem examination performed, no specific diagnostic pathology in any organ system has been identified. Previous theories relating to the cause of death in SIDS have included increased lower airway closure. We examined the airway morphometry of 57 infants who died of SIDS and compared these findings with those obtained from 21 age-matched infants who had died of non-SIDS causes. Airway wall dimensions, epithelial thickness, and the area of smooth muscle within the airway wall were measured. Airways from infants who died of SIDS showed a significantly higher proportion of airway smooth muscle than control airways when corrected for age and sex (p < 0.01). There was no significant difference between the groups for wall thickness or epithelial thickness. Increased airway smooth muscle in infants who have died of SIDS may contribute to excessive airway narrowing, raising the possibility that the cause of death in this condition is related to abnormalities in lower airway function.

Airway Resistance↗
PubMed1999

Factors associated with exercise adherence among older adults. An individual perspective.

This paper reviews the literature concerning factors at the individual level associated with regular exercise among older adults. Twenty-seven cross-sectional and 14 prospective/longitudinal studies met the inclusion criteria of a mean participant age of 65 years or older. The findings are summarised by demographics, exercise experience, exercise knowledge, physiological factors, psychological factors, activity preferences and perceived social influences. In general, education and exercise history correlate positively with regular exercise, while perceived physical frailty and poor health may provide the greatest barrier to exercise adoption and adherence in the elderly. Social-cognitive theories identify several constructs that correlate with the regular exercise behaviour of older adults, such as exercise attitude, perceived behavioural control/self-efficacy, perceived social support and perceived benefits/barriers to continued activity. As well, stage modelling may provide additional information about the readiness for regular exercise behaviour among older adults. However, relatively few studies among older adults exist compared with middle-aged and younger adults. Further, the majority of current research consists of cross-sectional designs or short prospective exercise trials among motivated volunteers that may lack external validity. Future research utilising longitudinal and prospective designs with representative samples of older adults will provide a better understanding of significant causal associations between individual factors and regular exercise behaviour.

Aged↗
PubMed1998

Maternal cigarette smoking is associated with increased inner airway wall thickness in children who die from sudden infant death syndrome.

The harmful effects of passive cigarette smoke exposure to infants include an increased frequency of asthma exacerbations, lower respiratory viral infections, and the sudden infant death syndrome (SIDS). Because of a difficulty in obtaining airway tissue from infants, little information is available on the effects of passive cigarette smoke exposure on the structure of the infant airway wall. We examined airway dimensions in 19 children who died from SIDS whose mothers smoked more than 20 cigarettes a day prenatally and postnatally, and compared these data with those from 19 infants who died from SIDS and had nonsmoking mothers. Total inner and outer wall areas were calculated for each airway and expressed in terms of the basement membrane perimeter (Pbm). Inner airway wall thickness was greater in the larger airways of those infants whose mothers had smoked more than 20 cigarettes a day. These findings suggest that infants exposed to a high level of passive cigarette smoke develop significant structural changes in their airways. Increased airway wall thickness may contribute to exaggerated airway narrowing and may help explain the previously observed abnormalities in neonatal lung function that have been described in infants of smoking mothers.

Airway Obstruction↗
PubMed1997

A function for CD2 on murine B cells?

CD2 is expressed on murine B cells, probably as a result of a chromosomal translocation event during speciation. There are no activating antibodies to mouse CD2, but when activated non-specifically, only T cells up-regulate their expression of CD2. We investigated the expression and function of CD2 on B cells using mice transgenic for human CD2 under the control of a modified version of the autologous promoter/enhancer that included the immunoglobulin enhancer. This construction directs expression of human CD2 to the B cell compartment as well as to the T cell compartment. In this paper, we confirm that activating pairs of anti-CD2 monoclonal antibodies are mitogenic for mouse T cells transgenic for human CD2. In contrast, mouse B cells that express similar amounts of human CD2 are not stimulated to proliferate by equivalent doses of these antibodies. We were also unable to show any functional consequence for these B cells as a result of CD2 ligation.

Adjuvants, Immunologic↗
PubMed1997

Exercise for the older woman: choosing the right prescription.

Many elderly women in industrially developed countries are at, or near to, functionally important strength related thresholds and so have either lost, or are in danger of losing, the ability to perform some important everyday tasks. The increased rate of healthcare expenditure due to loss of physical function is a major economic issue. Even though women make up most of the senior population, little current research on the impact of physical activity on strength and function in elderly people has included women. Elderly women typically have more barriers to participation in physical activity than do other groups and because of decreased participation, may possibly experience higher disability rates. Physical activity in old age may delay the progression of osteoporosis and is of paramount importance for maintaining the functional abilities needed to carry out daily tasks. Current research on exercise and the elderly population suggests that strength training may be the exercise mode of choice for maintenance of strength, physical function, bone integrity, and psychosocial health. This review summarises recent research on the impact of strength training on the fitness and health of elderly women and highlights considerations and potential barriers to physical activity that must be taken into account when planning exercise programmes for them.

Activities of Daily Living↗
PubMed1996

Invasive group B streptococcal disease: the emergence of serotype V.

Group B streptococci (GBS) cause invasive disease in neonates, pregnant adults, and nonpregnant adults with underlying or chronic disease. Previous studies found capsular serotypes Ia, Ib, II, and III cause invasive disease. Prospective population-based surveillance of invasive GBS disease was done from June 1992 to June 1993 in metropolitan Atlanta: 279 patients had invasive disease. Of these, 43% were < or = 6 months old, and 57% were adults. The incidence among all adults was 7.7/100,000/year, 33% higher than in 1989-1990 (P < .01). The incidence in nonpregnant adults was 5.9/100,000/year, 37% higher than in 1989-1990 (P < .02). Serotyping of 178 patient isolates revealed that 34% had GBS serotype Ia or Ia/c, 8% had Ib/c, 6% had II or II/c, 29% had III, 0% had IV, 21% had V, and 2% were nontypeable. Serotype V was recovered from all groups and was the most common serotype from nonpregnant adults. Serotype V isolates appeared to be highly related genetically. The increasing incidence of GBS disease in adults, the changing distribution of serotypes, and the emergence of serotype V will impact vaccine strategies.

Adolescent↗
PubMed1996

Effect of land-based and water-based fitness programs on the cardiovascular fitness, strength and flexibility of women aged 65-75 years.

The purpose of this study was to determine the effectiveness of a generalized water-based exercise program (WBE) compared to a land-based exercise program (LBE) on improving cardiorespiratory fitness, body composition, forward trunk flexion and strength measurements of elderly women aged 70 +/- 3.2 years (mean +/- SD). Forty-one healthy, sedentary women were selected to participate in the study and were randomly assigned to the LBE or WBE. The 2 groups exercised for 12 weeks, 3 times/week for 45 min. Fitness testing was done before, during and after training, and included measurements of peak aerobic power (VO2 peak), forward trunk flexion, sum of skinfolds, grip strength, curl-ups and push-ups. Between the tests performed before and after training, there were significant improvements in VO2 peak in both groups (p < 0.05) with no significant differences between the groups (p > 0.05). The LBE group also showed a significant improvement in the total number of curl-ups performed (p < 0.05). There were no significant differences in trunk forward flexion, total (right plus left) grip strength, push-ups, waist to hip ratio, sum of skinfolds or body mass index between the tests performed before and after training over time within groups or between groups (p > 0.05). The results show that general exercise interventions resulted in improvements in cardiovascular fitness (for both groups) and abdominal endurance (in the LBE only), but the two exercise programs used were not specific enough or long enough to cause improvements in muscular strength, flexibility or body composition. Furthermore, except for changes in abdominal endurance, the type of exercise venue (land vs. water) did not have a significant effect on the results obtained.

Aged↗
PubMed1995

IL-10 prevents naturally occurring fetal loss in the CBA x DBA/2 mating combination, and local defect in IL-10 production in this abortion-prone combination is corrected by in vivo injection of IFN-tau.

CBA x DBA/2 placentae are quantitatively or qualitatively deficient in their production of the anti-inflammatory Th2-type cytokines IL-4 and IL-10 compared with the nonresorption-prone CBA x BALB/c mating combination. Wastage in this mating combination is accompanied by increased levels of local inflammatory cytokines. In addition, alloimmunization enhances the placental production of IL-4 and IL-10 in CBA x DBA/2 matings. Furthermore, rIL-10 by itself completely reverses the high incidence of fetal resorption after i.p. injection. Conversely, anti-IL-10 increases the resorption rate, but only in CBA x DBA/2 matings. On the other hand, injecting either anti-IFN-gamma or pentoxifillin (an anti-TNF agent) partially reduces the resorption. When given together, they produce a synergistic remission of fetal loss. Finally, we report that recombinant ovine trophoblast protein, an IFN-tau which is known to influence reproductive outcome in ruminants, can also counteract increased CBA x DBA/2 fetal resorption. It simultaneously induces increased placental IL-4 and IL-10 production in this mating combination. These results indicate that the placentally produced anti-inflammatory cytokines can play a vital role in the survival to term of the fetal allograft, by counteracting deleterious inflammatory cytokines.

Abortion, Spontaneous↗
PubMed1993

The structure of large and small airways in nonfatal and fatal asthma.

Asthma is characterized by excessive airway narrowing and airway wall inflammation. In cases of fatal asthma, increased thickness of the airway wall is observed and may account for excessive airway narrowing when smooth muscle contracts. This study was undertaken to examine airway dimensions in large and small airways in both fatal and nonfatal cases of asthma. Airway wall areas (total, inner, and outer relative to smooth muscle layer), epithelial integrity, smooth muscle shortening, and the areas of smooth muscle, cartilage, and mucous glands were compared in transverse sections of large and small airways of subjects dying of asthma (fatal asthma, n = 11), those dying suddenly of nonrespiratory diseases and having a definite history of asthma (nonfatal asthma, n = 13), and those dying suddenly without any history of respiratory illness (control, n = 11). Airways were grouped by size using the basement membrane perimeter for comparison. All areas were expressed as areas per millimeter of basement membrane. In cartilaginous airways, the cases of fatal asthma had greater (p < 0.05) total wall, inner wall, outer wall, smooth muscle, mucous gland and cartilage areas than did control and nonfatal cases. The inner wall area was greater in the fatal and nonfatal cases than in the control cases (p < 0.05) in the small cartilaginous airways and membranous bronchioles (MB). In small MB (perimeter < 2 mm), the total and outer wall areas were greater (p < 0.05) in cases of fatal and nonfatal asthma than in control cases.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

The role of descending venography in the management of patients with chronic venous disease of the lower extremity.

The purpose of this paper is to evaluate the efficacy and clinical information obtained from the authors' first 17 consecutive descending venograms. All 17 patients had chronic venous disease refractory to standard conservative and surgical measures. The standard classification of valvular insufficiency was used in evaluating these venograms. There were no deaths, slight morbidity and minimal patient discomfort. In 16 patients meaningful clinical information was derived from the venograms, with 7 patients having deep venous valvular surgery. Descending venography will demonstrate the site of incompetent valves and estimate the degree of reflux. This test is necessary before anticipated reconstruction of deep vein valves.

Chronic Disease↗
PubMed1989

Synthetic parathyroid hormone-like protein-(1-74): biochemical and physiological characterization.

PTH-like protein-(1-74) [PTHLP-(1-74)] was synthesized and purified. On the basis of chromatographic criteria and amino acid composition of the full-length peptide, direct amino acid sequencing of the N-terminus, and amino acid composition and internal sequence of proteolytic fragments of PTHLP-(1-74), the synthetic peptide appears to be of high quality and purity. Physiological comparison of PTHLP-(1-74) to [Tyr36]-PTHLP-(1-36) amide and bovine (b) PTH-(1-34) indicates that all three peptides are of equivalent potency in the fetal rat long bone and rat osteosarcoma 17/2.8 adenylate cyclase assays. However, as in earlier studies with native and N-terminal PTHLPs, PTHLP-(1-74) is considerably less potent (2%) in stimulating the canine renal cortical adenylate cyclase assay than is bPTH-(1-34). Further, PTHLP-(1-74) displayed only 12% of the activity of bPTH-(1-34) in inducing hypercalcemia when infused into rats in vivo. These studies support the possibility that subclasses of PTH receptors or varying PTH- and PTHLP-signalling transduction mechanisms may exist. In addition, they emphasize the need to precisely define the naturally occurring secretory and circulating species of this novel class of peptide hormones.

Adenylyl Cyclases↗
PubMed1987

An inquiry into staffing, organisation and teaching in South African medical schools.

A comparative analysis of student/staff ratios (SSRs) revealed a very marked difference (2:1-5.3:1) between the most and least liberally staffed medical schools in South Africa. A study of workloads determined how the average medical teacher allocates time between teaching, clinical work, research and other activities. How medical teachers teach, their preparation for teaching, factors influencing teaching practices, teaching methods used and their attitudes to the use of educational resources were investigated. Just over 70% of medical teachers are teaching without any formal preparation although opposition to teaching courses appears to be diminishing. That medical education is teacher-orientated is obvious from the fact that resources that transmit information are used more than those that propagate interaction between teacher and student and encourage more complex forms of learning. Only 13% of medical teachers 'often' use educational objectives and the majority (58%) never use them at all. Criterion-referenced evaluation should have a place in medical education, where a core of minimum knowledge is considered essential, but over 80% of medical teachers 'never' use this method in assessing students.

Attitude↗
PubMed1982

A microteaching experiment at MEDUNSA.

Microteaching is a simplified teaching situation enabling novice teachers to practise their teaching skills. At MEDUNSA microteaching was incorporated into an induction course on teaching and learning, and participants were able to practise preparations, design and the presentation of good explanations. The presentations were recorded and played back on videotape. This provided multiple feedback and reinforcement via self-diagnosis and comments from teaching colleagues and a supervisor using questionnaires. The experiment was well received by participants and hopefully generated an interest in improved teaching via the analysis and monitoring of their own teaching performances.

Educational Measurement↗
PubMed1981

Selecting medical students at MEDUNSA. A preliminary report.

Because of the advantages involved, the 1981 intake of M.B. Ch.B I students to MEDUNSA were provisionally selected on the basis of their school record marks and their performance in the Academic Aptitude Test. However, when the latter scores were correlated with the students' matric. results they were found to have poor predictive value as a measure of success in the matriculation examination.

Educational Measurement↗