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Biomedical subjects

D Browne

Publications and source records attributed to D Browne.

At least 19 recordsLinked to original sources
PubMed2006

Quantification of dental fluorosis using fluorescence imaging.

Fluorescence imaging hardware and software have been recently employed to assess demineralization due to early dental caries. Dental fluorosis also presents as diffuse surface hypomineralization of enamel and in principle similar measurement methods might be applicable to both. The caries analysis system requires the user to select an area of sound enamel around the lesion so that the affected surface can be reconstructed and the lesion subtracted. Whereas early caries presents as discrete isolated lesions fluorosis is characterized by diffuse opacities covering most of the tooth. Consequently it is difficult to use commercial QLF software for the assessment of fluorosis, as there is typically no sound area of enamel to use for reconstruction. This study describes a fluorescent imaging device capable of recording digital images of the anterior teeth and also software that is able to objectively measure fluorosis area and severity. A convenience sample of 26 subjects with a range of fluorosis from TF scores 0-3 took part in the study. The upper left central incisor of these subjects was scored for fluorosis using the TF index, photographed using a conventional digital camera and imaged using the fluorescence imaging device. The TF index was then used to visually score the digital photographs and the fluorescence images. The data from the fluorescence method demonstrated a strong correlation with TF scores from fluorescence images (Kendall's tau = 0.862). The fluorescence imaging method shows promise as an objective, potentially blinded system for the longitudinal assessment of enamel fluorosis in vivo.

Child↗
PubMed2000

A simple high performance liquid chromatographic method for the quantification of total cotinine, total 3'-hydroxycotinine and caffeine in the plasma of smokers.

A simple isocratic HPLC procedure has been developed for the quantification of caffeine and the nicotine metabolites cotinine, 3'-hydroxycotinine, cotinine glucuronide and 3'-hydroxycotinine glucuronide in the plasma of smokers. The glucuronide conjugates were determined indirectly via initial basic hydrolysis of the analyte sample followed by quantification of the resulting deconjugation product. Plasma was basified, extracted with dichloromethane, evaporated, the residue dissolved water and an aliquot part was analyzed by HPLC. The method utilized a Partisil-10 SCX cation-exchange column and an isocratic mobile phase of sodium phosphate buffer: methanol (92:8 v/v, 0.1 M, adjusted to pH 4.8 with triethylamine) at a flow rate of 1.5 ml/min. UV detection was at 254 nm. All solutes were separated with good resolution, and quantification was determined using an internal standard of N,N-diethylnicotinamide. The retention times were: caffeine 5.1 min, 3'-hydroxycotinine 7.2 min, N,N-diethylnicotinamide 9.5 min, and cotinine 15.5 min. Detection limits for caffeine, 3'-hydroxycotinine, cotinine, and total cotinine were 10 ng/ml; the detection limit for total 3'-hydroxycotinine was 20 ng/ml. The inter-day and intra-day variations for all analytes were between 1 and 8%. This analytical method is suitable for the determination of caffeine and nicotine metabolite levels in large numbers of clinical samples.

Caffeine↗
PubMed2000

Paired-like homeodomain proteins Phox2a/Arix and Phox2b/NBPhox have similar genetic organization and independently regulate dopamine beta-hydroxylase gene transcription.

The homeodomain transcription factors Arix/Phox2a and NBPhox/Phox2b play a role in the specification of the noradrenergic phenotype of central and peripheral neurons. To better understand the functions of these two factors, we have compared the genetic organization, chromosomal location, and transcriptional regulatory properties of Arix and NBPhox. The gene structure is very similar, with each gene containing three exons and two introns, extending a total of approximately 5 kb. Arix and NBPhox are unlinked in human and mouse genomes. NBPhox is located on human Chromosome 4p12 and mouse Chromosome 5, while Arix is located on human Chromosome 11q13 and mouse Chromosome 7. Both proteins bind to three sites in the promoter proximal region of the rat dopamine beta-hydroxylase gene (DBH). In vitro, Arix and NBPhox form DNA-independent multimers and exhibit cooperative binding to the DB1 regulatory element, which contains two homeodomain recognition sites. Both proteins regulate transcription from the rat DBH promoter, and transcription is synergistically increased in the presence of the protein kinase A catalytic subunit (PKA) plus either Arix or NBPhox. The transcription factors exhibit similar concentration-dependent efficacies, and when they are coexpressed, transcription is stimulated to a value approximately equal to that seen with either factor alone. The N-terminal segment of Arix is essential for transcriptional regulatory activity, and this region bears 50% identity with NBPhox, suggesting a similar mechanism of transcriptional activation of the DBH gene. We conclude from this study that Arix and NBPhox exhibit indistinguishable and independent transcriptional regulatory properties on the DBH promoter.

Amino Acid Sequence↗
PubMed1998

Oncology services: the Department of Defense perspective.

The Department of Defense (DoD) military health system has responsibility for providing medical care for more than 8 million beneficiaries. This article discusses initiatives related to both the providing and purchasing of oncology services. A description of health care coverage under TRICARE, the Department's managed care program, which utilizes military treatment facilities and civilian health care providers, is provided. Participation in clinical trials by the DoD beneficiaries, oncology services in military treatment facilities, quality management programs, cancer research, and the development of new technologies to enhance early cancer detection are presented. Access to research trials and new technologies is necessary for a comprehensive approach to cancer care. Clinical trials have been the vehicle by which the oncology community developed most of its formal clinical evidence for the efficacy of various treatment approaches. The Department participates in clinical trials through cooperative group membership or affiliation. Through an interagency agreement with the National Cancer Institute, DoD beneficiaries have available the option of participating in NCI-sponsored clinical trials through the direct military care system or through civilian care with reimbursement for approved protocols nationwide. The DoD has been actively involved in breast cancer research since 1992 and prostate and ovarian cancer research since 1997. The goals of the cancer research programs are to expedite and facilitate breakthroughs in research, support innovative, and exploratory ideas with a vision to foster new directions, address neglected issues, and bring new investigators into the research arena. The program incorporates the consumer perspective by involving consumers in the decision-making process. The DoD health care system trains experts in the management of cancer patients and provides a multidisciplinary approach to care through the direct military health care system or through network providers as part of the TRICARE system. Although cost containment is key, the delivery of high quality health care that is easily accessible is a primary goal of the military health system. Provision of a comprehensive benefits package that includes a spectrum of care and employing outcomes measurements to evaluate care that is appropriate for the patient's disease is essential.

Clinical Trials as Topic↗
PubMed1998

Health risk behaviors of African American adolescents with mild mental retardation: prevalence depends on measurement method.

Health risk behaviors (e.g., substance use, violence, suicide, and car safety) of 194 14- to 17-year-old African American urban adolescents with mild mental retardation from special education classes were measured. One group was assessed using a confidential individual interview method, and an individually matched group was assessed with an anonymous group survey method. Participants completing the anonymous survey reported engaging more frequently in risk behaviors that respondents typically consider sensitive. In comparison to national and state populations of African American adolescents, urban African American adolescents with mild mental retardation appear to be at substantial elevated risk for engaging in alcohol binge drinking and weapon and gun carrying. Findings were discussed relative to cognitive and social deficits inherent in mild mental retardation.

Adolescent↗
PubMed1998

Cultural factors enhancing resilience and protecting against maladjustment in African American adolescents with mild mental retardation.

Researchers have found elevated risk for maladjustment associated with being an African American adolescent in an urban environment as well as being an individual with mental retardation. The culturally relevant factors of ethnic identification, intergenerational support, and church support were investigated in relation to high risk exposure on maladjustment in 147 urban African American adolescents enrolled in EMR special education classes. Maladjustment was measured with both self- and parent-report. Risk exposure was measured in the personal, social, and community domains. Results indicate that presence of cultural factors were associated with better adjustment generally. Furthermore, ethnic identification appeared to protect adolescents exposed to high-risk conditions against experiencing significantly elevated maladjustment. Implications of culture on intervention and prevention were discussed.

Adaptation, Psychological↗
PubMed1997

Effect of peptide to carrier ratio on the immune and ovarian response to inhibin immunization in cattle.

We report on the effects of the peptide to carrier ratio on the immune and biological response to inhibin immunization in cattle. A peptide sequence from the alpha C-subunit of bovine inhibin was synthesized and conjugated to human serum albumin (HSA) at ratios of 4.3 moles (L) and 13.1 moles (M) of peptide per mole of HSA. Hereford-cross heifers (n = 6 per group) were injected with 3 mg of one of the peptide conjugates at primary, followed by a booster injection (1.5 mg) 11 weeks later. Control heifers (n = 6) were injected with HSA only. Blood samples were taken at regular intervals to measure antibody titre. Ovulation rate was measured by ultrasonography. Antibodies were generated in both peptide immunized groups. Control heifers and group L heifers had 1 ovulation at all ovulatory cycles monitored. Ovulation rate was increased (P < 0.05) in group M immunized heifers, with four of six heifers having twin ovulations in the first cycle following boost. These data support those of previous studies which indicated that immunization against the alpha C-subunit of bovine inhibin significantly disrupted the mechanism(s) controlling ovulation rate in cattle. It also indicates that both the immune and associated biological response is dependent on the nature of the conjugate used for immunization, specifically the ratio of peptide to carrier.

Animals↗
PubMed1997

Exercise by prescription.

General Practitioners (GPs) see over 90% of their practice population in three years. Over 50% of the adult population is below the perceived level of physical activity as recognised by the Allied Dunbar Physical Activity score (Allied Dunbar, Health Education Authority and Sports Council, 1992). Physical fitness levels in adolescents and children are declining, while the incidence of obesity is increasing. GPs, with their Primary Health Care Team, are in a unique position to be able to discuss the health benefits of regular physical activity with their patients during the consultation and offer, if appropriate, a prescription for a course of physical activity to a local leisure centre or community activity centre. Many communities have facilities for physical activity. These include leisure centres, schools, village and church halls, the home and the general practice surgery. A directory of resources for physical activity for all age groups should be available in the surgery waiting room area. A community co-ordinator can network community facilities and resources to meet individual need. The co-ordinator can be funded by the general practice surgery, Health Authority, Local Authority, Parish or District Council. An agreed protocol for exercise prescription referrals to suitable community facilities can benefit patient health care for a variety of medical, surgical, social and mental conditions. Auditing exercise prescriptions shows a health benefit, with improved quality of living and reduced prescription medicines.

Adolescent↗
PubMed1997

Women in the Persian Gulf War: health care implications for active duty troops and veterans.

The health of women who participated in Operations Desert Shield/Storm was evaluated to better understand the medical requirements of deployed military women and women veterans of the Persian Gulf War. Women's health care needs during the Persian Gulf War were reported to be very similar to those of men, with the exception of gynecologic problems, which generally were not serious and did not require hospitalization. However, insufficient data were obtained to identify specific health care needs among deployed women troops. During the 5 years since the end of the Persian Gulf War, no unique health problems have been identified among women veterans. Whether there will be any exceptional long-term health care requirements currently is unknown. Nevertheless, important medical problems of all women-reproductive issues, menopause, osteoporosis, joint disease, breast cancer, heart disease, and stroke-inevitably will be major considerations when caring for this population of war veterans.

Adult↗
PubMed1995

The elective use of oxytocin infusion during labour in nulliparous women using epidural analgesia: a randomised double-blind placebo-controlled trial.

The obstetric outcome following the elective use of oxytocin infusion was determined in a randomised, double-blind placebo-controlled trial. 93 nulliparous women in a London hospital, who had requested epidural analgesia in labour (</= 6 cm.), were given an infusion of oxytocin (n = 46) or placebo (n = 47). The initial epidural dose was 15 ml of 0.125% bupivacaine, followed by an infusion at 10 ml per h, with 15 ml top-ups if required. When oxytocin was used electively there was a reduction in the length of the first stage of labour from 696 min to 578 min, (P < 0.05) even though more than half of the control group (53%) required oxytocin augmentation. There was no significant difference between the number of operative deliveries (34 [74%] vs 35 [74%]). The rotational delivery rate was less in the study group (2 [4%] vs 5 [11%]), though this did not reach significance. There were no adverse effects on the fetus, as judged by cord pH measurement, Apgar score, admission to the special care baby unit and neonatal jaundice. The prophylactic use of oxytocin in nulliparous women with epidurals reduces the length of the first stage of labour and appears to be safe. It does not reduce the operative delivery rate.

Journal Article↗
PubMed1995

A physical map of the region spanning the chromosome 12 translocation breakpoint in a mesothelioma with a t(X;12)(q22;p13).

We have constructed a physical map of a 4.6-cM region of human chromosome band 12p13.3 that contains a translocation breakpoint from a mesothelioma with a t(X;12)(q22;p13). The map contains a contig of 22 yeast artificial chromosomes (YACs), onto which we have placed 18 sequence tagged site (STS) markers, including seven genes: D12S370, FGF6, KCAN1, KCNA5, KCNA6, NTF3, and VWF. A second YAC contig, comprised of 22 YAC clones, was located distal to the mesothelioma breakpoint and contained 12 STS markers, including four genes (CACNL1A1, D12S380E, D12S381E, and D12S382E). Based on STS content and fluorescence in situ hybridization experiments, two stable, nonchimeric YAC clones were found that span the mesothelioma breakpoint. A long-range restriction map of an 800-kb region was constructed and used to refine the mesothelioma breakpoint to a region of approximately 100 kb, flanked by the potassium channel genes KCNA1 and KCNA5. The latter was confirmed by direct visual hybridization (DIRVISH) experiments, using cosmids isolated for markers flanking the breakpoint as probes.

Animals↗