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Biomedical subjects

J Elliot

Publications and source records attributed to J Elliot.

At least 19 recordsLinked to original sources
PubMed2005

Reduced apoptosis of memory T-cells in the inner airway wall of mild and severe asthma.

Effector memory T-cells (CD45RO+) may provide pro-inflammatory signals that contribute to the persistent airway inflammation that is characteristic of asthma, and reduced apoptosis of these cells may prolong their effects. The present authors compared apoptosis of CD45RO+ T-cells in the inner airway wall in nonfatal asthma (n = 7), fatal asthma (n = 7) and control (n = 8) cases. Apoptotic cells were identified using both the terminal deoxynucleotidyl transferase dNTP nick end-labelling (TUNEL) technique and cell morphology. The percentage of CD45RO+ T-cells that were apoptotic was significantly greater in control cases compared with nonfatal and fatal cases of asthma, respectively, in small (42+/-19, 16+/-9, 7+/-6%), medium (40+/-12, 15+/-11, 12+/-8%) and large airways (42+/-15, 23+/-18, 18+/-12%). The reduction in the percentage of apoptotic CD45RO+ cells in the cases of asthma was observed in both blood vessels and the interstitium in large airways. In conclusion, these data suggest that reduced apoptosis may prolong the active life of effector memory T-cells in the airways. It is possible that survival signals may be received before cells migrate into the interstitium of the inner airway wall.

Adolescent↗
PubMed2002

Evaluation of a community intervention programme for preschool behaviour problems.

OBJECTIVES: To evaluate an early intervention project focused on improving child prereading skills and parent behaviour-management skills, for 4-year-old children in the western suburbs of Melbourne (Victoria, Australia). METHODOLOGY: Following screening of a large sample of preschoolers, four groups were constructed: (i) children receiving a phonological skills-based prereading package in their normal preschool programme; (ii) children whose parents attended six sessions of child behaviour management skill training; (iii) children who received both interventions; and (iv) a control group. Pre-, post-, 1 and 2 year follow-up measures were taken to assess effects on child behavioural and learning adjustment. RESULTS AND CONCLUSIONS: This community based intervention resulted in positive effects, despite being of low intensity, in achieving significantly less hyperactive/distractable behaviour in children from the combined intervention group at 2 years postintervention. Anxiety problems were also reduced at the post-treatment phase. The prereading package did not demonstrate any effects on reading skills and was deemed to be insufficiently intensive to affect a population of disadvantaged preschoolers. This universal-type of intervention was well accepted by the community, but there is need for further effort to increase recruitment of families of at-risk children into such programmes.

Child Behavior Disorders↗
PubMed2001

The stability of benzoyl peroxide by isothermal microcalorimetry.

Isothermal microcalorimetry may be used to determine kinetic and thermodynamic parameters for chemical reactions. This paper reports rate constants, determined as a function of temperature, and the activation enthalpy for the degradation of solid benzoyl peroxide as determined by isothermal microcalorimetry. Studies were conducted on aqueous suspension phase, solid benzoyl peroxide. In addition, supporting evidence is cited from work carried out in this laboratory on the solution phase degradation of benzoyl peroxide using UV-visible spectrophotometry. The activation energy obtained by microcalorimetry was E(a)=137.8+/-6.6 kJ mol(-1) and the activation energy obtained from UV-visible spectrophotometry was E(a)=112.7+/-4.2 kJ mol(-1).

Benzoyl Peroxide↗
PubMed2001

The stability of benzoyl peroxide formulations determined from isothermal microcalorimetric studies.

Recent developments in the analysis of microcalorimetric data output allow the possibility of determining both thermodynamic and kinetic parameters for complex reaction systems. Such experiments routinely take around 50 h, hence qualifying for the description rapid. The methods have earlier been applied to a study of the stability of benzoyl peroxide itself in aqueous suspension. This paper reports the results of isothermal microcalorimetric study of the stability of benzoyl peroxide in the presence of a wide range of excipients and in formulated materials. The results are shown to assist in formulation design, are achieved rapidly and are derived from direct experimental study of the complex systems themselves. That is, no ancillary information is required nor are the studies invasive or destructive.

Benzoyl Peroxide↗
PubMed2001

Increased airway responsiveness and decreased alveolar attachment points following in utero smoke exposure in the guinea pig.

Maternal smoking during pregnancy has been shown to result in abnormalities in lung function in newborn infants, including reduced expiratory flow and increased airway responsiveness to inhaled agonists. The mechanisms by which this occurs remain unclear. Using a guinea pig model of in utero smoke exposure, we measured airway responsiveness and lung morphology in a group of neonatal guinea pigs 21 d after delivery. Pregnant guinea pigs were exposed to cigarette smoke from Day 28 to term (Day 68 of gestation). After delivery newborn animals did not receive any smoke exposure. Airway wall thickness, smooth muscle area, and the number of points where the alveoli attached to the airway adventitia were measured. Airway responsiveness was increased (p < 0.05) and the mean distance between alveolar attachment points was increased (mean 0.052 +/- SE 0.001 mm versus 0.046 +/- 0.001, p = 0.001) in animals exposed to cigarette smoke in utero compared with nonexposed animals. Although not statistically significant, both the inner and outer airway wall and the smooth muscle area were greater in exposed animals compared with nonexposed animals. The increased mean distance between alveolar attachments in the smoke-exposed group was the result of a reduction in the number of attachments and an increase in the outer airway wall perimeter. These findings suggest that the increased airway responsiveness observed in postnatal animals, subsequent to in utero cigarette smoke exposure, may be the result of decreased alveolar attachment points to the airways and changes in airway dimensions.

Animals↗
PubMed2000

Modulation of [3H]MK-801 binding to NMDA receptors in vivo and in vitro.

[3H]MK-801 binding in vivo was used to determine the occupancy of NMDA receptor ligands shown to allosterically modulate binding in vitro. ED(50) values (mg/kg) were obtained for the channel blockers (+)-5-methyl-10,11-dihydro-5,4-dibenzo[a,d]cyclohepten-5,10-imine maleate ((+)-MK-801, 0.2), 1-(1-phenylcyclohexyl)piperidine (phencyclidine, PCP, 1.7) and ketamine (4.4). Antagonists at the glutamate (DL-(2-carboxypiperazine-4-yl)propyl-1-phosphonate (DL-CPP, 5.7)) and glycine site (7-Chloro-4-hydroxy-3-(3-phenoxy)-phenyl-2(H)quinolinone (L-701,324, 14.1), 3R(+)cis-4-methyl-pyrrollid-2-one (L-687,414, 15.1)) inhibited [3H]MK-801 binding in vivo to varying maximum levels (69%, 103% and 45%, respectively). NR2B subunit-selective compounds acting at the ifenprodil site inhibited [3H]MK-801 in vivo by a maximum of 52-72% and gave ED(50) values (mg/kg) of: (+/-)-(1S*, 2S*)-1-(4-hydroxyphenyl)-2-(4-hydroxy-4-phenylpiperidino)-1-propanol ((+/-)CP-101,606), 1.9; (+/-)-(3R, 4S)-3-[4-(4-fluorophenyl)-4-hydroxypiperidin-1-yl]chroman-4,7-diol ((+/-)CP-283,097), 1.8; (+/-)-(R*, S*)-alpha-(4-hydroxyphenyl)-beta-methyl-4-(phenylmethyl)-1-piperidine propanol ((+/-)Ro 25-6981), 1.0; ifenprodil, 6.0. The glycine site agonist D-serine stimulated binding to 151% of control with an ED(50) of 1.7 mg/kg. Results show that [3H]MK-801 binding in vivo may be used to measure receptor occupancy of ligands acting not only within the ion channel but also at modulatory sites on the NMDA receptor complex.

Animals↗
PubMed2000

Effects of one year of resistance training on the relation between muscular strength and bone density in elderly women.

OBJECTIVES: There is a paucity of long term studies on exercise training in elderly women. The purpose of this study was to investigate the effects of one year of progressive resistance exercise (PRE) on dynamic muscular strength and the relations to bone mineral density (BMD) in elderly women. METHODS: Forty four healthy sedentary women (mean age 68.8 years) volunteered for this study and were randomly assigned to either an exercise group or a control group. The exercise group were involved in three one hour sessions a week for 52 weeks of supervised PRE to strengthen the large muscle groups of the body, while the control group were instructed to continue their normal lifestyle. The exercise circuit included three sets of eight repetitions at 75% of one repetition maximum focused on the large muscle groups. BMD was measured by dual energy x ray absoptiometry (Lunar DPX) at the lumbar spine and at three sites in the proximal femur. Other selected parameters of physical fitness were also measured. RESULTS: Statistical analyses (analysis of covariance) showed significant strength gains (p < 0.01) in bilateral bench press (> 29%), bilateral leg press (> 19%), and unilateral biceps curl (> 20%). No significant difference between groups was evident in body weight, grip strength, flexibility, waist to hip ratio, or the sum of eight skinfolds. Significant relations (p < 0.05) were recorded between dynamic leg strength and the BMD of the femoral neck, Ward's triangle, and the lumbar spine. CONCLUSIONS: Significant strength changes, after one year of PRE, were evident in elderly women, and the muscle increases may parallel changes in BMD; however, correlation coefficients were moderate.

Aged↗
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

Estrus and pregnancy rate of dairy cows given one or two doses of prostaglandin F2 alpha 8 or 24 hours apart.

A total of 329 cows was used in 2 experiments to study the effect of PGF2a given 8 or 24 h apart on the number of cows observed in estrus within 7 d and the pregnancy rate to a single insemination at this time. In Experiment 1, 233 cows were divided into 2 groups. Cows in Group 1 (n = 117) were treated twice with 25 mg, im of PGF2a (0 and 8 h) while cows in Group 2 (n = 116) were treated only once (0 h). In Experiment 2, 96 cows were divided into 2 groups. Cows in Group 1 (n = 49) were treated twice with 25 mg, im of PGF2a (0 and 24 h) while cows in Group 2 (n = 47) were treated only once (0 h). In Experiment 1, blood samples were obtained from cows in both groups on Days 0 and 2. However, in Experiment 2, blood samples were obtained from cows in both groups only on Day 0. Plasma progesterone concentration was determined using radioimmunoassay. Cows in both experiments were observed for estrus within 7 d of treatment and were inseminated within 12 h of the observed estrus. In Experiment 1, more cows in Group 1 were observed in estrus within 7 d than in Group 2 (P <0.03). In Experiment 2, there was no significant difference in the number of cows in both groups that were observed in estrus within 7 d. However, the interval from treatment to the first observed estrus for cows not observed in estrus within 7 d was significantly longer in cows treated at 0 and 24 h compared with the cows treated once at 0 h. In both experiments, the pregnancy rate for cows inseminated within 7 d was similar for cows in all groups. From the results of this study, it is concluded that treatment of dairy cows with 2 luteolytic dosages of PGF2a at an 8-h interval resulted in more cows being observed in estrus than at a 24-h interval.

Journal Article↗
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↗