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Biomedical subjects

D Evans

Publications and source records attributed to D Evans.

At least 73 records · Page 4Linked to original sources
PubMed2000

Evidence for TeV Emission from GRB 970417a.

Milagrito, a detector sensitive to very high energy gamma rays, monitored the northern sky from 1997 February through 1998 May. With a large field of view and a high duty cycle, this instrument was well suited to perform a search for TeV gamma-ray bursts (GRBs). We report on a search made for TeV counterparts to GRBs observed by BATSE. BATSE detected 54 GRBs within the field of view of Milagrito during this period. An excess of events coincident in time and space with one of these bursts, GRB 970417a, was observed by Milagrito. The excess has a chance probability of 2.8x10-5 of being a fluctuation of the background. The probability for observing an excess at least this large from any of the 54 bursts is 1.5x10-3. No significant correlations were detected from the other bursts.

Journal Article↗
PubMed2000

Developing and communicating a long-term treatment plan for asthma.

The treatment of asthma, according to current guidelines, requires complex treatment regimens that change as clinical conditions improve or deteriorate. We have developed a practical way to communicate long-term treatment plans in chart form in the primary care setting that is easy for patients to follow and use. The chart has been an important element in two interventions that have resulted in positive changes in health behavior and health outcomes in children with asthma. The plan provides recommendations for patients and families to make adjustments in medication based on changes in symptoms or peak expiratory air flow, or both, that are consistent with the Asthma Guidelines Expert Panel Report 2, 1997. The plan also indicates when the number and dosage of drugs should be increased or decreased and when emergency care should be sought, consistent with the Asthma Guidelines. By placing considerable control in the family's hands and by clearly delineating the conditions under which medicines can be reduced or discontinued, the physician provides incentives for families to adhere to the long-term treatment plan for asthma.

Anti-Asthmatic Agents↗
PubMed2000

Variation in the PPARalpha gene is associated with altered function in vitro and plasma lipid concentrations in Type II diabetic subjects.

AIMS/HYPOTHESIS: Peroxisome proliferator activated receptor alpha (PPARalpha) regulates genes involved in lipid metabolism, haemostasis and inflammation, in response to fatty acids and fibrates, making it a candidate gene for risk of dyslipidaemia, atherosclerosis and coronary artery disease. Plasma non-esterified fatty acids are increased in subjects with Type II (non-insulin-dependent) diabetes mellitus, suggesting that PPARalpha could link Type II diabetes and dyslipidaemia, and affect response to fibrates. This has been investigated in association studies in healthy and diabetic subjects and in vitro studies. METHODS: The human PPARalpha gene was isolated and screened for variation by single strand conformation polymorphism analysis. Genotypes were determined for 129 Type II diabetic subjects and 2508 healthy men. The association with plasma lipid concentrations was examined. The function of the V162 variant was examined in co-transfection assays. RESULTS: We identified two polymorphisms, one in intron 3 and a missense mutation, leucine 162 to valine, in the DNA binding domain. In Type II diabetic patients, V162 allele carriers had higher total cholesterol, HDL cholesterol and apoAI whereas intron 3 rare allele carriers had higher apoAI concentrations. By contrast, no effect was observed in healthy rare allele carriers. In vitro, the V162 variant showed greater transactivation of a reporter gene construct. CONCLUSION/INTERPRETATION: Naturally occurring variation alters PPARalpha function, influencing plasma lipid concentrations in Type II diabetic patients but not healthy people. This demonstrates that PPARalpha is a link between diabetes and dyslipidaemia, and so could influence the risk of coronary artery disease, the greatest cause of morbidity and mortality in Type II diabetes.

Apolipoprotein A-I↗
PubMed2000

A clinical evaluation of an alternating-pressure mattress replacement system in hospital and residential care settings.

An observational study was carried out to compare wound healing on alternating-pressure mattress replacement systems (APMRS) and other surfaces in an elderly population in acute and residential care settings. Subjects were assessed for the reduction in their pressure ulcers at approximately two weeks and per day, and a visual analogue scale was used to record the patients' comfort. Seven and ten subjects were allocated to the Nimbus III APMRS (Huntleigh Healthcare Ltd) in the hospital and residential care settings respectively. There was no significant difference in the healing of the subjects' sores in the two areas either at two weeks or per day. Five people were allocated to control surfaces in the hospital setting (mainly APMRS; Pegasus Airwave, Pegasus Egerton) and ten in the residential care setting (mainly alternating-pressure overlays; AlphaXcell, Huntleigh Healthcare Ltd). There was no significant difference in the healing of subjects' sores in the two areas, either at two weeks or per day. The trial APMRS was found to be equally comfortable in either setting, and in both settings the control surfaces were not regarded as significantly different in terms of comfort. These findings, from a small sample, promote discussion about the use of pressure-relieving equipment in settings where there are older people who may be at particular risk from pressure damage and where nursing interventions are less intensive and routine.

APACHE↗
PubMed2000

Conducting a systematic review.

In response to the growing volume of health care literature and the variable quality of reported studies, systematic reviews have increasingly been used to guide health care decisions because of their rigorous summary of the research. Systematic reviews utilise planned methods of identifying, appraising, then summarising the results from individual studies. The steps in performing a systematic review include: preparing a detailed research protocol; selecting criteria for inclusion of articles in the review; systematically searching the published and unpublished literature; determining which articles meet the predefined inclusion criteria; critically appraising the quality of the research; extracting outcome data from the research report and statistically combining data, where appropriate, in order to summarise the best available evidence on the topic of interest. These processes are documented in the systematic review report, and can be subject to peer review and critique like other research.

Humans↗
PubMed2000

Long-term effects of asthma education for physicians on patient satisfaction and use of health services.

This randomized clinical trial evaluated the long-term impact of an interactive seminar for physicians based on principles of self-regulation on clinician behaviour, children's use of health services for asthma, and parent's views of physician performance. Seventy-four general practice paediatricians, and 637 of their asthma patients aged 1-12 yrs, were randomized to treatment or control. Children and parents were blind to physicians' participation. Data were collected at baseline and follow-up through self-administered surveys (paediatricians), telephone interviews (parents) and medical records. The seminar focused on development of communication and teaching skills and use of therapeutic medical regimens for asthma as outlined in the National Asthma Education and Prevention Program guidelines. Approximately 2 yrs postintervention, treatment group physicians were more likely than control physicians to: use protocols for delivering asthma education (odds ratio (OR) 4.9, p=0.2), write down for patients how to adjust medicines when symptoms change (OR 5.7, p=0.05), and provide more guidelines for modifying therapy (OR 3.8, p=0.06). Parents scored treatment group physicians higher than control physicians on five specific positive communication behaviours. Children seen by treatment group physicians had fewer hospitalizations (p=0.03) and those with higher levels of emergency department (ED) use at baseline had fewer subsequent ED visits (p=0.03). No differences regarding the number of office visits were noted. There were no significant differences found between treatment and control group physicians in the amount of time spent with patients during office visits (26 versus 29 min) or in the number of patients treated with anti-inflammatory medicine. It is concluded that interactive asthma seminars for paediatricians had significant long-term benefits for their asthma care.

Adult↗
PubMed2000

Regional differences in optic disc and retinal circulation.

PURPOSE: To determine regional differences in the circulation of the optic disc, the peripapillary choroid and the retinal vessels using the techniques of computerized image analysis and fluorescein angiography. METHODS: Ten young normal subjects were studied. Fluorescein angiography was performed with a scanning laser ophthalmoscope. The rate of filling of fluorescein or slope was measured in the four quadrants of the optic disc, the peripapillary choroid and the major retinal arteries and veins. A total of 125 points was measured from each image of the fluorescein angiograms for a total of 20 to 30 images. Retinal vessel width was measured using computerized image analysis. RESULTS: Comparison of the rates of filling of fluorescein or slopes showed significant differences from zero among the four quadrants of the optic disc (p= 0.01 to <0.02), of the peripapillary choroid (p=0.01 to <0.05) and among the major retinal arteries (p=0.01 to <0.02) and retinal veins (p=0.02 to <0.05). No significant differences were noted between the quadrants for retinal arterial width with the retinal veins only showing a significant difference between the inferior nasal and inferior temporal vein (p=0.02 to <0.05). CONCLUSION: Evaluation of the circulation of the optic disc, retina, and peripapillary choroid should take into account regional differences among these structures.

Adult↗
PubMed2000

Variation in the gene for human peroxisome proliferator activated receptor gamma (PPARgamma) does not play a major role in the development of morbid obesity.

OBJECTIVE: To determine the extent of variation in the gene for peroxisome proliferator activated receptor gamma (PPARgamma) in patients with morbid obesity. SUBJECTS: Two hundred morbidly obese patients who underwent gastric banding surgery and 192 healthy blood donors. Diabetics were excluded. EXPERIMENTAL: The frequency of the P115Q and P12A variants in the PPARgamma gene was determined. Single strand conformational polymorphism (SSCP) analysis was performed on all exons, exon/intron boundaries and part of the promoter of the PPARgamma gene on a sub-group of 67 morbid obese patients. RESULTS: None of the morbid patients or the blood donors were carriers of the P115Q mutation. The frequency of the P12A polymorphism did not differ significantly between morbid obese patients and controls and there was no statistically significant association between P12A and BMI. Male blood donors who were A12A homozygotes had statistically significant higher serum leptin concentrations (P = 0.001). Mutation screening revealed that one patient had a T -->G transversion at -208 in the promoter of PPARgamma-2, two had silent mutations, one a T-->C transition in the third base of codon 144 and the other a C-->T transition in codon 297. The fourth patient had a CGC-->TGC transition in codon 316 resulting in the replacement of an arginine with a cysteine. This mutation was not found in any other morbidly obese patient. CONCLUSION: Variation in the PPARgamma gene is unlikely to play a major role in the development of morbid obesity.

Adult↗
PubMed2000

Frequency of and interaction between polymorphisms in the beta3-adrenergic receptor and in uncoupling proteins 1 and 2 and obesity in Germans.

OBJECTIVE: To determine the role of polymorphisms in the genes for beta3-adrenergic receptor (beta3-AR) and in uncoupling proteins 1 and 2 (UCP-1, UCP-2) in obesity. DESIGN: Association study with three polymorphisms and obesity. SUBJECTS: Two hundred and thirty-six morbidly obese patients who underwent gastric banding surgery, 381 patients from the medical clinic and 198 healthy blood donors. MEASUREMENTS: The frequencies of the W64R in beta3-AR, the 3826A-->G in UCP-1 and the 45bp insertion in the 3 untranslated region of exon 8 in UCP-2 polymorphisms were determined. RESULTS: There were no significant differences in the frequencies of the beta3-AR and UCP-1 polymorphisms between obese (body mass index, BMI > 30 kg/m2) and lean subjects. Lean, but not obese, carriers of the R allele of beta3-AR had a significantly higher BMI. The mean age of obese subjects (excluding diabetics) who were carriers of the G allele of the UCP-1 polymorphism, 36y, was significantly younger than wild-type, 40y (P= 0.007). This effect was not seen in lean subjects. The effect of the G allele on the mean age of obese subjects was more apparent in subjects who were also carriers of the R allele of the beta3-AR polymorphism. The frequency of the ins allele of UCP-2 was significantly higher in obese subjects, 0.31, than in lean, 0.24 (P= 0.002) and carriers of the ins allele had a significantly higher BMI, 38 vs 35 (P= 0.005). There was no association between any of the polymorphisms and type II diabetes. CONCLUSION: In a German population, there was no association between the W64R in beta3-AR or the 3826A-->G in UCP-1 polymorphisms and obesity. However, they act synergistically to accelerate the development of obesity. The 45bp insertion in the 3 untranslated region of exon 8 in UCP-2 polymorphism is associated with obesity.

Adult↗
PubMed2000

The management of severe dental phobia in an adolescent boy: a case report.

Dental fear is a widespread problem that represents one of the major barriers to dental care. This report describes a case study of a 12-year-old boy who presented with dental phobia characterized as 'fear of catastrophe', 'generalized dental fear' and 'fear of specific stimuli'. The referral came from his general dental practitioner who had been unable to carry out even the simplest dental procedure on him. The patient required prevention, conservation and root canal therapy. The case illustrates the use of physical strategies, including muscle relaxation and relaxation breathing; practice strategies, including graded exposure and cognitive strategies, combined with individual control methods and inhalation sedation to successfully complete the dental treatment plan.

Adaptation, Psychological↗
PubMed2000

Carcinoembryonic antigens are targeted by diverse strains of typable and non-typable Haemophilus influenzae.

Haemophilus influenzae (Hi), a commensal of the human respiratory mucosa, is an important cause of localized and systemic infections. We show that distinct strains belonging to typable (THi) and non-typable (NTHi) H. influenzae target human carcinoembryonic antigens (the membrane associated CEA family of cell adhesion molecules, are now termed CEACAMs). All strains of H. influenzae biogroup aegyptius (Hi-aeg) and more than 70% of THi and NTHi strains tested specifically recognize CEACAMI-Fc soluble constructs. Furthermore, transfection of Chinese hamster ovary cells with human CEACAM1 cDNA alone was sufficient for promoting Hi interactions with the transfected cells. The majority of the Hi-aeg strains tested interacted with soluble constructs containing only the N-terminal domain. In contrast, several THi and NTHi strains reacted with soluble constructs only when additional extracellular A and B domains of the receptor were present. The use of monoclonal antibodies confirmed that THi and NTHi strains also interact primarily at the N-domain. We used site-directed mutants of CEACAM1 that contained substitutions at surface exposed amino acids and a molecular model of the N-domain to identify the residues involved in interactions with Hi ligands. The studies show that a common region exposed at the CFG face of the molecule is targeted by diverse Hi strains. However, mutation at distinct sites within this area affected the interactions of distinct strains signifying the potential for tissue tropism via this receptor. Analyses of the molecular basis of interaction with human cell lines and purified CEA show that Hi strains, especially those belonging to Hi-aeg, interact with multiple CEACAMs. Because Neisseria meningitidis (Nm) strains are also known to bind at the CFG face of the receptor, we used Nm and Hi strains in co-infection experiments and demonstrate competition between these mucosal pathogens in colonization of target cells via CEACAMs.

Amino Acid Sequence↗
PubMed2000

The correction of penile curvature with the Essed-Schröder technique: a long-term follow-up assessing functional aspects and quality of life.

OBJECTIVES: To investigate, in a retrospective analysis using a detailed questionnaire, the long-term functional results in and quality of life (QoL) of patients after undergoing the Essed-Schröder procedure, a standard technique for correcting penile curvature. PATIENTS AND METHODS: From 1994 to 1999, 40 patients (median age 24 years) had their penile curvature corrected using a modified Essed-Schröder technique. Assessments by the investigators and a self-completed questionnaire were used to evaluate the functional and cosmetic aspects of the procedure, and QoL issues. RESULTS: Complete follow-up data were available in 31 of the 40 (78%) patients (19 with congenital curvature and 12 with Peyronie's disease). The median follow-up was 22 months. The degree of penile angulation before surgery was estimated as < 45 degrees in five patients, 45-90 degrees in 22 and > 90 degrees in four. In 21 patients (68%) sexual intercourse was uncomfortable or impossible; 26 (84%) reported an impaired QoL because of the penile curvature. After surgery the cosmetic and functional result was good or sufficient in 25 patients (81%); all 25 were able to have sexual intercourse with no problems. Penile shortening (> 2 cm) was reported by six patients. A significant improvement in QoL was reported by 15 patients (48%), but of the 12 patients with Peyronie's disease before surgery, six reported impaired rigidity and two recurrence of their penile curvature afterward. Whereas only seven of 12 patients with Peyronie's disease reported good functional results, 18 of the 19 with congenital curvature reported good or excellent results after surgery. CONCLUSION: The Essed-Schröder method is a simple operation which provides good functional and cosmetic results. Patients with congenital curvature of the penis have better results than those with Peyronie's disease.

Adolescent↗
PubMed2000

Fluconazole for the prevention and treatment of tinea gladiatorum.

BACKGROUND: Tinea gladiatorum is a common problem in competitive wrestling. It impacts on a wrestler's ability to compete. Several methods have been advocated to prevent these infections; however, no well-designed study of pharmacologic prophylaxis has been conducted. METHODS: In a double blind placebo-controlled trial during the 1998 to 1999 regular wrestling season, wrestlers were randomized to receive 100 mg of fluconazole once weekly or placebo once weekly. Those not involved in the study were treated as a second control group. The effects of prophylaxis were also examined by assessing treatment of clinical infections with fluconazole 200 mg weekly for 4 weeks. RESULTS: There was a significantly smaller incidence of infection in those given fluconazole (6%) than in those receiving placebo (22%) and those not involved in the prophylaxis phase (18%) (P<0.05). There was also a significant reduction in the total number of infections in the fluconazole group (P<0.05). Prophylaxis with fluconazole did not impact on the severity of disease, if contracted, when compared with the placebo prophylaxis participants who contracted tinea corporis. Of 21 wrestlers with tinea infections and positive cultures, 14 were able to have their isolates identified as Trichophyton tonsurans. CONCLUSIONS: Fluconazole is effective and safe for primary prevention of tinea gladiatorum. We must now define when and in what population prophylaxis would be warranted.

Adolescent↗
PubMed2000

trans splicing of polycistronic Caenorhabditis elegans pre-mRNAs: analysis of the SL2 RNA.

Genes in Caenorhabditis elegans operons are transcribed as polycistronic pre-mRNAs in which downstream gene products are trans spliced to a specialized spliced leader, SL2. SL2 is donated by a 110-nucleotide RNA, SL2 RNA, present in the cell as an Sm-bound snRNP. SL2 RNA can be conceptually folded into a phylogenetically conserved three-stem-loop secondary structure. Here we report an in vivo mutational analysis of the SL2 RNA. Some sequences can be changed without consequence, while other changes result in a substantial loss of trans splicing. Interestingly, the spliced leader itself can be dramatically altered, such that the first stem-loop cannot form, with only a relatively small loss in trans-splicing efficiency. However, the primary sequence of stem II is crucial for SL2 trans splicing. Similarly, the conserved primary sequence of the third stem-loop plays a key role in trans splicing. While mutations in stem-loop III allow snRNP formation, a single nucleotide substitution in the loop prevents trans splicing. In contrast, the analogous region of SL1 RNA is not highly conserved, and its mutation does not abrogate function. Thus, stem-loop III appears to confer a specific function to SL2 RNA. Finally, an upstream sequence, previously predicted to be a proximal sequence element, is shown to be required for SL2 RNA expression.

Animals↗
PubMed2000

A clinical evaluation of the Nimbus 3 alternating pressure mattress replacement system.

This study assessed the clinical effectiveness of the Nimbus 3 alternating pressure mattress replacement system (APMRS) on pressure ulcer healing and comfort in subjects > or = 65 years, with at least a Grade 2 ulcer and some mobility problems. Twelve patients in a hospital setting were randomly allocated to the Nimbus 3 or another APMRS, and 20 residents in a nursing home setting to the Nimbus 3 or an alternating pressure mattress overlay. Wound surface area (WSA) (cm2) was recorded twice weekly and comfort once weekly. In the hospital setting, there were no significant differences between groups in the reduction in WSA per day. In the nursing home setting, though subjects on Nimbus 3 had significantly more pressure ulcers at baseline, there were no significant differences between groups in the reduction in WSA per day. Nimbus 3 was statistically more comfortable than control surfaces. The study's sample size has not shown the products were different with regard to clinical effectiveness. However, it might serve as a pilot for a larger, multi-centre RCT aimed at establishing the efficacy of a pressure-relieving (PR) device on pressure ulcer healing.

Aged↗
PubMed2000

Cost-effectiveness of childhood immunization reminder/recall systems in urban private practices.

OBJECTIVE: To assess cost and cost-effectiveness of immunization reminder/recall systems in the private sector. METHODS: A manual postcard system (mail) was compared with a computer-based telephone system (autodialer) and control. Costs included time costs and the cost of equipment and supplies. The cost per child and the incremental cost of the intervention relative to control were computed. Cost-effectiveness ratios were computed for return visits and for immunizations delivered. RESULTS: The average cost per child was $2.28 for the mail group and $1.47 for the autodialer group. The incremental visit cost relative to the control was higher for the mail group ($9.52) than for the autodialer group ($3.48). The autodialer was more cost-effective in delivering immunizations: $4. 06 per extra immunization (autodialer) versus $12.82 (mail). CONCLUSIONS: Excluding start-up costs, the autodialer system was most cost-effective. Including autodialer equipment costs, the autodialer system is more cost-effective only for larger practices.

Cost-Benefit Analysis↗