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Biomedical subjects

D Efron

Publications and source records attributed to D Efron.

At least 19 recordsLinked to original sources
PubMed2004

Implementation of evidence based guidelines for paediatric asthma management in a teaching hospital.

AIMS: To evaluate a systematic approach to the development and implementation of evidence based asthma management guidelines. METHODS: Comparative study of children (2-18 years) with acute asthma; a control cohort (cohort 1) was recruited before implementation of the guidelines and two cohorts were recruited after implementation (cohorts 2 and 3). RESULTS: There was no difference in the proportion of patients who reattended in the six months following initial presentation for cohort 1 (21.5%), cohort 2 (27.8%), or cohort 3 (25.4%) and no difference in readmission rates (11.4%, 11.3%, 11.0% respectively). There was no difference in measures of asthma morbidity between the cohorts at 3 and 6 months across three domains: interval symptoms, exercise limitation, and bronchodilator use. Of those who did not have a management plan before presentation, one was provided to 46.9% of cohort 1, 74.8% of cohort 2, and 81.1% of cohort 3. There was no difference comparing cohort 2 or cohort 3 with cohort 1 regarding quality of life for either the subjects or their parents. CONCLUSIONS: Implementation of our evidence based guidelines was associated with the improved provision of asthma management plans, but there was no effect on reattendance or readmission to hospital, asthma morbidity, or quality of life. Future efforts to improve asthma management should target specific components of asthma care.

Acute Disease↗
PubMed2003

Disruption of a novel member of a sodium/hydrogen exchanger family and DOCK3 is associated with an attention deficit hyperactivity disorder-like phenotype.

BACKGROUND: Attention deficit hyperactivity disorder (ADHD) is a complex condition with high heritability. However, both biochemical investigations and association and linkage studies have failed to define fully the underlying genetic factors associated with ADHD. We have identified a family co-segregating an early onset behavioural/developmental condition, with features of ADHD and intellectual disability, with a pericentric inversion of chromosome 3, 46N inv(3)(p14:q21). METHODS: We hypothesised that the inversion breakpoints affect a gene or genes that cause the observed phenotype. Large genomic clones (P1 derived/yeast/bacterial artificial chromosomes) were assembled into contigs across the two inversion breakpoints using molecular and bioinformatic technologies. Restriction fragments crossing the junctions were identified by Southern analysis and these fragments were amplified using inverse PCR. RESULTS: The amplification products were subsequently sequenced to reveal that the breakpoints lay within an intron of the dedicator of cytokinesis 3 (DOCK3) gene at the p arm breakpoint, and an intron of a novel member of the solute carrier family 9 (sodium/hydrogen exchanger) isoform 9 (SLC9A9) at the q arm. Both genes are expressed in the brain, but neither of the genes has previously been implicated in developmental or behavioural disorders. CONCLUSION: These two disrupted genes are candidates for involvement in the pathway leading to the neuropsychological condition in this family.

Adult↗
PubMed2001

Nitric oxide in the healing wound: a time-course study.

INTRODUCTION: We studied the time course of nitric oxide expression in the healing wound and the cell populations responsible for its synthesis. METHODS: Twenty four Lewis rats underwent subcutaneous implantation of polyvinyl alcohol sponges. Rats were sacrificed in groups of three on days 1, 3, 5, 7, 10, 14, and 35 after wounding. The conversion of 3H-labeled arginine to 3H-labeled citrulline, with or without N(G)-L-monomethyl-arginine (L-NMMA) in harvested sponges, was measured. Nitrate/nitrite (NOx) in plasma and wound fluid was quantified by Greiss reaction. Inducible nitric oxide synthase (iNOS) gene expression was determined by Northern analysis and reverse transcriptase-polymerase chain reaction (RT-PCR). Inducible NOS was identified in specific wound cell populations by dual-label flow cytometry. RESULTS: Nitric oxide synthase (NOS) activity peaked at 24 h after wounding (37.7 +/- 0.9 micromol citrulline per milligram sponge), with a steady decline thereafter. Percentage inhibition of NOS activity by l-NMMA was highest on days 1-7 (70-80%). This declined to 50% by day 10 and to 25% by days 14-35. The iNOS gene expression paralleled NOS biochemical activity. RT-PCR confirmed low-level expression up to 10 days after wounding. Plasma NOx levels remained within a narrow range of 22.6 +/- 1.3 to 29.3 +/- 1.5 microM throughout the postwounding period, while corresponding levels in wound fluid (microM) increased steadily from 27 +/- 3.8 on day 1 to 107.2 +/- 10.0 on day 14. Inducible NOS expression was detectable by fluorescence-activated cell sorting in wound macrophages on days 1 and 3 after wounding. CONCLUSIONS: Our findings suggest maximal NOS activity early in cutaneous wound healing, with sustained production up to 10 days after wounding. NOS biochemical activity was paralleled by iNOS gene expression. Plasma NOx remained constant, while wound fluid NOx increased steadily to peak at day 14. Wound macrophages appear to be a source of nitric oxide production in the early phase of wound healing.

Animals↗
PubMed2000

Immediate and delayed effects of treatment at the Dead Sea in patients with psoriatic arthritis.

The purpose of this study was to evaluate the immediate and delayed effects of balneotherapy at the Dead Sea on patients with psoriatic arthritis (PsA). A total of 42 patients with PsA were treated at the Dead Sea for 4 weeks. Patients were randomly allocated into two groups: group 1 (23 patients) and group 2 (19 patients). Both groups received daily exposure to sun ultraviolet rays and regular bathing at the Dead Sea. Group 1 was also treated with mud packs and sulfur baths. Patients were assessed by a dermatologist and a rheumatologist 3 days before arrival, at the end of treatment, and at weeks 8, 16, and 28 from the start of treatment. The clinical indices assessed were morning stiffness, right and left hand grip, number of tender joints, number of swollen joints, Schober test, distance from finger to floor when bending forward, patient's self-assessment of disease severity, inflammatory neck and back pain and psoriasis area and severity index (PASI) score. Comparison between groups disclosed a similar statistically significant improvement for variables such as PASI, morning stiffness, patient self-assessment, right and left grip, Schober test and distance from finger to floor when bending forward. For variables such as tender and swollen joints, and inflammatory neck and back pain, improvement over time was statistically significant in group 1. Addition of mud packs and sulfur baths to sun ultraviolet exposure and Dead Sea baths seems to prolong beneficial effects and improves inflammatory back pain.

Arthritis, Psoriatic↗
PubMed2000

Medium-term outcomes are comparable with short-term outcomes in children with attention deficit hyperactivity disorder treated with stimulant medication.

OBJECTIVE: To compare the short- and medium-term effects of psychostimulant medication in children with attention deficit hyperactivity disorder (ADHD). METHODS: Seventy-three children with ADHD participated in a double-blind crossover study of dextroamphetamine (DEX) and methylphenidate (MPH; results previously reported). At the completion of this study, subjects continued to take the preferred stimulant. Subjects were restudied 6-9 months later. The principal outcome measures were the Revised Conners' Parent and Teacher Rating Scales. RESULTS: Fifty-three families (73%) returned the follow-up surveys. At 6-9 months, mean T scores were still significantly lower than the mean at baseline for all factors of both the CPRS-R and CTRS-R (P < 0.01). There were no statistically significant differences between scores at 6-9 months and scores at the completion of the corresponding medication period in the crossover trial. CONCLUSIONS: After 6-9 months treatment with stimulant medication, ratings remained significantly better than at baseline. This suggests that the early benefits of stimulants are sustained for at least 6 months.

Adolescent↗
PubMed2000

Role of arginine in immunonutrition.

Arginine plays an important role in many physiologic and biologic processes beyond its role as a protein-incorporated amino acid. Dietary supplementation of arginine can enhance wound healing, regulate endocrine activity and potentiate immune activity. Under normal unstressed conditions the arginine requirement of adult humans is fulfilled by endogenous sources, however this is compromised during times of stress, especially in critical illness. These finding have led to use of arginine supplementation as part of an immune-enhancing dietary regimen to help combat the immune suppression seen in such patients. Though the results from studies examining the use of this type of immunonutrition in critically ill patients are far from definitive, they are promising that this mode of therapy may be of some advantage. A better understanding of the in vivo biology of arginine and its metabolism is necessary to truly define a benefit from arginine supplementation.

Adult↗
PubMed1998

Child and parent perceptions of stimulant medication treatment in attention deficit hyperactivity disorder.

OBJECTIVE: To evaluate child and parent perceptions of treatment with stimulant medication in a sample of children with attention deficit hyperactivity disorder (ADHD). METHODOLOGY: Child and parent perceptions questionnaires were completed for 102 subjects participating in a double-blind, crossover trial of methylphenidate (MPH) and dexamphetamine (DEX). RESULTS: Most children viewed medication effects favourably, although 12.7% and 18.8% of children reported feeling worse than usual when taking MPH and DEX, respectively. There was disagreement between the child's and parents' perceptions of response in over one quarter of cases. Most disagreements involved parents viewing the child's response favourably, but the child rating reporting an unfavourable outcome. Side-effects were the main determinant of children's perceptions of adverse response. CONCLUSIONS: A substantial proportion of children with ADHD experience treatment with stimulant medication adversely. Side-effects are the principal determinant of negative child perceptions. Parental report is usually in agreement with child report; however, parental report alone is not infallible in providing reliable information regarding effects as experienced by the child.

Adolescent↗
PubMed1997

Side effects of methylphenidate and dexamphetamine in children with attention deficit hyperactivity disorder: a double-blind, crossover trial.

OBJECTIVE: To compare the side effect profiles of methylphenidate (MPH) and dexamphetamine (DEX) in children with attention deficit hyperactivity disorder (ADHD), as well as to determine which symptoms are genuine adverse effects of stimulant medication, as opposed to aspects of the child's underlying behavioral phenotype. DESIGN: Double-blind, crossover study. SETTING: Pediatric teaching hospital ambulatory behavior clinic. SUBJECTS: A total of 125 children with ADHD with a mean age of 104.8 months. INTERVENTIONS: Subjects received DEX (0.15 mg/kg/dose) and MPH (0.3 mg/kg/dose) twice a day for 2 weeks each in a randomized order. OUTCOME MEASURES: The Barkley Side Effects Rating Scale (17 symptoms; 0 = absent, severity rated from 1 to 9) was completed by parents at baseline and at the completion of each trial fortnight. RESULTS: Subjects' parents reported a significantly greater mean number (8.19) and mean severity (4.08) of "side effects" before commencing the trial than during the MPH period (number 7.19; severity 3.24), but not the DEX period (number 7.64, severity 3.73). The mean severity (but not mean number) was greater on DEX than on MPH. DEX caused more severe insomnia and appetite suppression compared with the baseline rating. Appetite suppression was the only item rated more severe on MPH than at baseline. Six side effects were significantly more severe on DEX than MPH: insomnia, irritability, proneness to crying, anxiousness, sadness/unhappiness, and nightmares. None were more severe on MPH than DEX. Overall, both MPH and DEX were well tolerated by most subjects, with only four subjects discontinuing the trial period because of severe adverse effects (2 -1.6%- on each stimulant). CONCLUSIONS: Many symptoms commonly attributed to stimulant medication are actually preexisting characteristics of children with ADHD and improve with stimulant treatment. At the doses investigated, both DEX and MPH caused appetite suppression, and DEX caused insomnia. Negative emotional symptoms were more severe on DEX than MPH.

Adolescent↗
PubMed1997

Methylphenidate versus dexamphetamine in children with attention deficit hyperactivity disorder: A double-blind, crossover trial.

OBJECTIVE: To compare methylphenidate (MPH) and dexamphetamine (DEX) in a sample of children with attention deficit hyperactivity disorder (ADHD). METHOD: A total of 125 children with ADHD received both MPH (0.3 mg/kg twice daily) and DEX (0.15 mg/kg twice daily) for 2 weeks a double-blind, crossover study. Outcome measures were Conners' Parent Rating Scale-Revised, Conners' Teacher Rating Scale-Revised, a Parent Global Perceptions questionnaire, the Continuous Performance Test, and the Barkley Side Effects Rating Scale. RESULTS: There were significant group mean improvements from baseline score on all measures for both stimulants. On the Conners' Teacher Rating Scale-Revised, response was greater on MPH than DEX on the conduct problems and hyperactivity factors, as well as on the hyperactivity index. On the Conners' Parent Rating Scale-Revised, anxiety was the only factor to differ significantly, in favor of MPH. Parents rated 73% of subjects as globally improved on MPH and 69% improved on DEX, compared with baseline. Overall, 46% of parents chose MPH as the preferred drug, compared with 37% who chose DEX. On the Continuous Performance Test, there was no difference in the number of correct responses or errors between the two drugs. CONCLUSIONS: Most children with ADHD improve significantly on both MPH and DEX. There was a slight advantage to MPH on most measures.

Adolescent↗
PubMed1996

Dead Sea mineral-based cosmetics--facts and illusions.

Modern Dead Sea cosmetics have developed in order to meet the demands of new regulations, technical opportunities, and today's consumer expectations for higher quality standards and proven performance. As an example of the application of this approach, the authors describe the development of a new cosmetic formulation, based on "Osmoter", a special Dead Sea mineral composition, and the evaluation of this formulation's effect on the depth of skin wrinkles, by a controlled assay. Possible mode of action is discussed.

Chemistry, Pharmaceutical↗