Search PubMed⌕ Search

Biomedical subjects

A James

Publications and source records attributed to A James.

At least 55 records · Page 3Linked to original sources
PubMed1999

Psychophysical assessment of the affective components of non-painful touch.

A novel psychophysical procedure for the evaluation of the affective components of touch was developed. A fabric material was stroked across the test site at a controlled direction and velocity, after which the subject provided a numerical estimate of pleasantness. Significant differences were detected for the sites tested (FACE vs ARM), the fabric materials used (VELVET, COTTON and PLASTIC MESH), and the velocity of motion (0.5, 5 and 50 cm/s). Attesting to their validity, estimates of pleasantness correlated negatively with estimates of unpleasantness obtained for the same stimuli. Moreover, subjects were reasonably consistent in their ratings upon stimulus replication. These findings demonstrate that the hedonic qualities of touch can be psychophysically evaluated, and that valid and reliable estimates are obtained.

Adolescent↗
PubMed1999

Cell behaviour as a dynamic attractor in the intracellular signalling system.

We present a model of the cell signalling network based on the generic properties of interactions between protein kinases (PKs) and protein phosphatases (PPs) inside cells. The model is designed to examine the global properties and intrinsic dynamics of the phosphorylation system. A genetic algorithm (GA) is used to evolve populations of "cells". The GA selects cells and ranks them based on an analysis of the dynamics of the proteins within the networks from a series of different random starting conditions. The fittest cells are taken to be those which can generate a variety of different "behaviours" from a series of different initial conditions. During the GA, intracellular protein interactions evolve via mutation and an analogue of domain shuffling between protein types that is thought to occur during biological evolution. The dynamics of the simulated networks are presented and we discuss the hypothesis that changes in the behaviour of a cell may be interpretable as a switch between attractor basins in the intracellular signalling network.

Algorithms↗
PubMed1999

Segregation analysis of the specific response to allergens: a recessive major gene controls the specific IgE response to Timothy grass pollen.

Segregation analysis of the specific response to allergens (SRA) was performed in a sample of 234 randomly selected Australian families using the regressive models. Various SRA phenotypes were considered using broad and narrow definitions of these phenotypes, according to the type of test used, skin test or RAST test, and the specificity of the response to allergen. Strong evidence for familial dependencies among blood relatives was shown for most SRA phenotypes, especially when using a broad definition. There was no evidence for a Mendelian factor accounting for the familial transmission of these broadest phenotypes, which may involve multiple factors preventing the clear detection of a major effect with Mendelian transmission. However, segregation of a Mendelian recessive major gene was detected for one SRA sub-phenotype, the IgE response to a single allergen, Timothy grass pollen, measured by the RAST test. Identification of a specific SRA phenotype controlled by a major gene may have important implications for further linkage studies.

Adolescent↗
PubMed1999

Repetition of deliberate self-harm by adolescents: the role of psychological factors.

The aim of this study was to examine the relationship between psychological variables and repetition of deliberate self-harm by adolescents (n=45) aged 13-18 years who had been admitted to a general hospital having taken overdoses. Standardized measures of depression, hopelessness, suicidal intent, impulsivity, trait and state anger, self-esteem and problem-solving (both self-report and observer-rated) were administered to the adolescents while still in the general hospital. Repetition was assessed on the basis of previous overdoses (n=14) and repetition of self-harm (self-poisoning and self-injury) during the subsequent year (n=9). Adolescents with a history of a previous overdose and/or who repeated self-harm during the following year (n=18) differed from non-repeaters in having higher scores for depression, hopelessness and trait anger, and lower scores for self-esteem, self-rated problem-solving and effectiveness of problem-solving rated on the basis of the Means End Problem Solving test, all measured at the initial assessment. These differences largely disappeared when level of depression was controlled for. Similarly, differences found between repeaters and non-repeaters in the year following the index overdoses for problem-solving were much reduced when account was taken of differences in depression scores. Depression is a key factor associated with risk of repetition of adolescent self-harm (and hence of suicide risk). In the management of adolescents who have harmed themselves, careful assessment of depression and appropriate management of those who are depressed is essential.

Adolescent↗
PubMed1999

A randomised controlled trial of home-based rehabilitation versus outpatient-based rehabilitation for patients suffering from chronic schizophrenia.

BACKGROUND: Outpatient-based treatments for patients suffering from chronic schizophrenia inadvertently exclude a significant proportion of subjects because they are often too poorly motivated to attend for treatment. In addition there are also concerns about whether the skills that are learnt in a hospital setting will generalize to situations when the individuals are at home. This study attempted to redress some of these potential deficiencies and followed on from an earlier local study which found that a community-based team met more of the needs of patients suffering from chronic schizophrenia. METHOD: Seventy-five patients suffering from chronic schizophrenia were allocated randomly to receive traditional outpatient-based or home-based rehabilitation from a clinical psychologist and an occupational therapist. They were assessed before and after 9 months of treatment on a range of clinical, social and quality of life outcomes. Distress to carers was also assessed. Readmission to hospital was recorded for each subject. RESULTS: There were significant reductions in socially embarrassing behaviour (SBS), increases in interpersonal functioning and recreational activities and a trend for quality of life to improve in the home-based group. There were fewer admissions in the home-based group but the differences, although financially substantial, were not statistically significant. CONCLUSIONS: The home-based rehabilitation service was well received by the majority of patients suffering from chronic schizophrenia and led to some improvement in social behaviour, interpersonal functioning, recreational activities and quality of life.

Adult↗
PubMed1999

Exhaled carbon monoxide in childhood asthma.

OBJECTIVES: Oxidative stress and inflammation induce the expression of heme oxygenase-1, which produces carbon monoxide (CO), and nitric oxide synthase, which produces nitric oxide (NO). Exhaled CO and NO levels are elevated in asthmatic patients and are decreased after corticosteroid treatment, suggesting that they may be useful as noninvasive markers of airway inflammation. STUDY DESIGN: We measured forced expiratory volume in the first second, PC(20), and exhaled CO and NO levels in 29 children (18 boys, mean age 11.5 +/- 0.53 years) with asthma of different severity and 40 nonsmoking children without asthma (21 boys, mean age 8.1 +/- 0.35 years). We also studied whether upper respiratory tract infections were associated with elevated exhaled CO. RESULTS: Exhaled CO levels (ppm) were significantly higher (2.17 +/- 0.21) in children with persistent asthma compared with those in children with infrequent episodic asthma (1.39 +/- 0.18, P <.05) and healthy children (1.01 +/- 0.12, P <.001). The CO levels in children with infrequent episodic asthma and the normal control group, however, were not different. In contrast, exhaled NO levels (ppb) were higher in children with persistent asthma (24.2 +/- 5.9, P <.001) and infrequent episodic asthma (14.5 +/- 3.73, P <.05) than in normal subjects (5.1 +/- 0.24), but no significant difference was seen between the 2 asthmatic groups. In healthy children with upper respiratory tract infections (n = 12), exhaled CO concentrations were significantly elevated (2.16 +/- 0.33) during the acute symptomatic phase. No correlation was found between exhaled CO and forced expiratory volume in the first second or PC(20). CONCLUSIONS: Noninvasive measurement of exhaled CO may provide complementary data for assessment of asthma control in children. However, elevated CO levels are nonspecific and may be found in association with an acute viral illness.

Asthma↗
PubMed1999

Nitrotyrosine formation in the airways and lung parenchyma of patients with asthma.

BACKGROUND: Recent evidence has shown that nitric oxide (NO) levels are increased in asthmatic airways. Although the role of NO in asthma is unknown, reactive metabolites of NO may lead to nitrotyrosine formation and promote airway dysfunction. OBJECTIVE: The aim of this study was to determine whether nitrotyrosine, as a marker of nitrating species, could be found in the airways and lung parenchyma of subjects with asthma who died of status asthmaticus or other nonrespiratory causes. METHODS: Lung tissue specimens were obtained from 5 patients who died of status asthmaticus, 2 asthmatic patients who died of nonrespiratory causes, and 6 nonasthmatic control subjects who died of nonrespiratory causes. Lung sections were stained for immunofluorescence with use of an antinitrotyrosine antibody, followed by a indiocarbocyanine (Cy5, Jackson Immunochemicals, Westgrove, Pa)-conjugated secondary antibody. RESULTS: Nonasthmatic lungs showed little or no nitrotyrosine staining, whereas asthmatic lungs demonstrated significantly more staining of nitrotyrosine residues distributed in both the airways and lung parenchyma. CONCLUSION: This study demonstrates the presence of nitrotyrosine, and hence evidence of formation of nitrating species, in the airways and lung parenchyma of patients with asthma who died of status asthmaticus or other nonrespiratory causes. This finding supports the concept that widespread airway and parenchymal inflammation occurs in asthma, and, more specifically, that NO and its reactive metabolites may play a pathophysiologic role in asthma.

Adolescent↗
PubMed1999

A two-rate hypothesis for patterns of retention in psychosocial treatments of cocaine dependence: findings from a study of African-American men and a review of the published data.

In this article, we examine patterns of retention in psychosocial treatment programs for cocaine dependence. We present new data from a comparison trial of Drug Counseling and Supportive-Expressive Psychotherapy and review published data from all studies utilizing psychosocial interventions alone. We compared Drug Counseling and Psychotherapy on rates of pretreatment and during-treatment attrition in a sample of 294 African-American men seeking treatment for cocaine dependence (mean age, 37.6). Survival analyses were utilized to identify significant differences in during-treatment attrition between the two treatments and to identify significant changes in the rate of attrition during the course of each treatment. We then compared the patterns of retention in this study with those from other available published reports of psychosocial treatments for cocaine abuse. The weekly during-treatment attrition rate was not constant in either treatment condition, and the change in rate of attrition occurred at week six for both Drug Counseling and Psychotherapy. Comparison with other studies suggested that the during-treatment pattern of attrition among most psychosocial treatments for cocaine abuse is typified by two rates, with the rate of subject attrition early in treatment being greater than the rate of later attrition and also exhibiting greater variance. Future studies of treatment retention should identify significant shifts in the rate of during-treatment attrition, examine if the pattern of attrition is typified by two rates, and, if so, determine where the shift occurs. Future studies should also assess if changes in the rate of during-treatment attrition signal the timeframes within which strategies that enhance retention can be implemented in the treatment program.

Adolescent↗
PubMed1999

Do adolescents who take overdoses have specific psychological characteristics? A comparative study with psychiatric and community controls.

OBJECTIVE: To determine whether specific psychological factors characterize adolescents who take overdoses. METHOD: Measures of problem-solving, depression, anger, impulsivity, and self-esteem were investigated in 33 adolescents after an overdose, 30 psychiatric controls, and 30 community controls, the groups being matched for age and sex. All subjects were interviewed twice, 6 weeks apart. The first interview in the overdose group followed an overdose. RESULTS: Significant differences were found between the 3 groups on all of the variables at both interviews. However, when depressive affect (Beck Depression Inventory) was controlled for, all of these differences disappeared, except for impulsivity at the second interview. Here the overdose group remained more impulsive than the other groups even when depression was considered. CONCLUSIONS: Depression is the most important factor in the presentation of a range of psychological characteristics of adolescents who take overdoses, and this remains true at 6-week follow-up. Impulsivity is apparently an important factor, independent of depression, in adolescent self-poisoning. Further research is required to determine the mediating role of impulsivity in this behavior and to identify treatment strategies for it.

Adolescent↗
PubMed1999

Decline in lung function and mortality: the Busselton Health Study.

BACKGROUND: There is a direct association between level of lung function, measured by forced expiratory volume in 1 second (FEV1) and mortality rates. A low FEV may result from an increased decline in FEV1 with age, which may be an independent predictor of mortality. OBJECTIVE: To examine the association between decline in FEV1 and mortality in a cohort from a community health study. SETTING AND METHODS: From five cross sectional studies in Busselton between 1969 and 1981 a cohort of 751 men and 940 women was identified who had three assessments of lung function over a six year period and had other health related data collected. Each subject's average FEV1 and decline in FEV1 (litre/year) were calculated from these three measurements. Mortality follow up to December 1995 was obtained. Cause of death was taken as the certified cause of death from the death certificate using ICD9 categories. RESULTS: The average decline in FEV1 was 0.04 litre per year (SD = 0.07) for men and 0.03 litre per year (SD = 0.06) for women. Average FEV1 was significantly associated with all cause and cardiovascular disease mortality in both sexes. In women there was a significant association between decline in FEV1 and death from all causes, after adjusting for average FEV1, age, smoking, coronary heart disease, and cardiovascular disease risk factors; a 0.05 litre per year increase in the rate of decline of FEV1 increased the risk of death for all causes by 1.23 (95% confidence interval 1.06, 1.44). In men the effect of decline in FEV1 on death rate was less; for all men the hazard ratio for a 0.05 litre/year greater decline in FEV1 was 1.19 (0.99, 1.21). CONCLUSION: Decline in lung function, measured by FEV1 is a predictor of death, independent of average FEV1 and risk factors for cardiovascular disease.

Alcohol Drinking↗
PubMed1999

Evaluation of a randomised controlled trial of adult asthma education in a hospital setting.

BACKGROUND: Although patient education is a key step in the Australian Asthma Management Plan, its impact has not been assessed in a hospital outpatient asthma clinic. METHODS: A controlled trial was undertaken in 125 adults with asthma recruited from the Alfred Hospital Asthma and Allergy Clinic and randomly allocated to an intervention (n = 64) or control (n = 61) group. Subjects in the intervention group attended three education sessions, each of 90 minutes duration, spread over three successive weeks. Asthma knowledge, quality of life, self-management skills, and attitudes and beliefs about asthma were assessed by questionnaires at baseline and after six months. The intervention group was also assessed immediately after the three education sessions. The control group was evaluated after six months of usual care. RESULTS: Asthma knowledge improved significantly in the intervention group after three education sessions (p = 0.0001) and this was retained six months later (p = 0.03). The impact of asthma on quality of life decreased significantly immediately after intervention (p = 0.03) but this was not maintained six months later (p = 0.35). On the other hand, the intervention had little impact on self-management skills or attitudes and beliefs about asthma. However, the control group had also improved their knowledge, quality of life and self-management skills after six months of usual care. The difference in mean change in knowledge score at six months between the intervention and control groups was not significant (p = 0.51). CONCLUSIONS: In contrast to some other studies, a limited asthma education programme in a hospital outpatient setting had a positive impact on patients' knowledge of asthma, but not on their quality of life, self-management skills, or attitudes and beliefs about asthma.

Adult↗
PubMed1999

Extended tumour necrosis factor/HLA-DR haplotypes and asthma in an Australian population sample.

BACKGROUND: Tumour necrosis factor (TNF) is a potent pro-inflammatory cytokine which is prominent in asthmatic airways. TNF shows genetic variations in secretion which are linked to polymorphisms in the TNF gene complex and the surrounding major histocompatibility (MHC) locus. These polymorphisms do not seem to be themselves functionally important. In these circumstances, the identification of disease associated haplotypes (combination of alleles on individual chromosomes) may narrow the search for polymorphisms which alter gene function. METHODS: TNF-308, LTalpha NcoI, and HLA-DRB1 polymorphisms were investigated for association with asthma, bronchial responsiveness, and medication use in 1004 subjects in 230 families from a general population sample. RESULTS: The common LTalpha NcoI*1/TNF-308*2/HLA-DRB1*03 haplotype, which was present in 11% of unrelated individuals, was weakly associated with asthma (OR = 1.38, p = 0.016, corrected for familial correlation). The rarer LTalpha NcoI*1/TNF-308*2/HLA-DRB1*02 haplotype, which was found in 0.6% of unrelated subjects, was more strongly associated with asthma (OR = 6.68, p = 0.002). This haplotype also showed association with bronchial hyperresponsiveness (OR = 21.9, p = 0. 0000) and the use of inhaled or oral steroids (OR 8.0, p = 0.04). CONCLUSIONS: The results of this study show only two extended TNF/HLA-DR haplotypes to be associated with asthma. The search for functional alleles responsible for an increased risk of asthma should concentrate on the LTalpha NcoI*1/TNF-308*2/HLA-DRB1*02 haplotype.

Adolescent↗
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

Severe hemolytic disease from rhesus anti-C antibodies in a surrogate pregnancy after oocyte donation. A case report.

BACKGROUND: Maternal sensitization with rhesus anti-C antibodies is comparatively rare and usually benign. In pregnancies conceived using donor oocytes, the mother's blood group may differ from that of both the father and the oocyte donor, making blood group incompatibility more likely. CASE: Twins, the result of a surrogate pregnancy using donor oocytes, were born with severe hemolytic disease due to rhesus anti-C antibodies. Both infants required exchange transfusion for profound anemia at birth. Isoimmunization in the surrogate mother was not detected antenatally. The twins were delivered by emergency cesarean section due to fetal compromise, detected fortuitously when the mother attended for routine fetal assessment at 35 weeks' gestation. CONCLUSION: Isoimmunization with anti-C antibodies is not always benign and may cause significant hemolytic disease. With the success of in vitro fertilization and oocyte donation, more infertile couples may use these methods to conceive, with or without surrogacy arrangements. In such cases, the provision of antenatal care may become a complex matter, involving several parties, and good communication between everyone involved is vital. In pregnancies conceived with donor oocytes, there may be a higher risk of blood group incompatibility, and special vigilance is warranted.

Cesarean Section↗
PubMed1998

Partial tetrasomy with triplication of chromosome (5) (p14-p15.33) in a patient with severe multiple congenital anomalies.

We report on a newborn infant with a de novo triplication of the distal segment of 5p: 46,XX,trp(5) (pter-->p14::p14-->p15.33::p15.33--> qter) and multiple congenital anomalies consistent with triplication of 5p. Partial triplication was documented by fluorescence in situ hybridization with a cosmid probe specific for 5p15.2 and microdissected probes obtained from "5pter." Partial duplication of the short arm of chromosome 5 is associated with a specific phenotype that appears to be dependent on the chromosomal region duplicated. Duplication of 5p with breakpoints proximal to band p14 is generally associated with distinct craniofacial malformations, cardiac, renal, intestinal, and limb defects, and mental retardation, whereas duplications with breakpoints distal to 5p14 result in a milder phenotype characterized by minor facial anomalies, developmental delay, and seizures. The most proximal breakpoints of the partial triplication in this patient was estimated to be 5p14, suggesting that a more severe phenotype can occur with triplication of the more distal segment.

Abnormalities, Multiple↗
PubMed1998

Epoxybutene-hemoglobin adducts in rats and mice: dose response for formation and persistence during and following long-term low-level exposure to butadiene.

Measurement of specific adducts to hemoglobin can be used to establish the dosimetry of electrophilic compounds and metabolites in experimental animals and in humans. The purpose of this study was to investigate the dose response for adduct formation and persistence in rats and mice during long-term low-level exposure to butadiene by inhalation. Adducts of 3,4-epoxy-1-butene, the primary metabolite of butadiene, with N-terminal valine in hemoglobin were determined in male B6C3F1 mice and male Sprague-Dawley rats following exposure to 0, 2, 10, or 100 ppm of 1,3-butadiene, 6 h/day, 5 days/week for 1, 2, 3, or 4 weeks. Blood samples were collected from groups of five mice and three rats at the end of each week during the 4 weeks of exposure and weekly for 3 weeks following the end of the 4-week exposure period. The increase and decrease, respectively, of the adduct levels during and following the end of the 4-week exposure followed closely the theoretical curve for adduct accumulation and removal for rats and mice, thereby demonstrating that the adducts are chemically stable in vivo and that the elimination follows the turnover of the red blood cells. The adduct level increased linearly with butadiene exposure concentration in the mice, whereas a deviation from linearity was observed in the rats. For example, after exposure to 100 ppm butadiene, the epoxybutene-hemoglobin adduct levels were about four times higher in mice than in rats; at lower concentrations of butadiene, the species difference was less pronounced. Blood concentrations of epoxybutene, estimated from hemoglobin adduct levels, were in general agreement with reported concentrations in mice and rats exposed by inhalation to 62.5 ppm. These studies show that adducts of epoxybutene with N-terminal valine in hemoglobin can be used to predict blood concentration of epoxybutene in experimental animals.

Algorithms↗