PubMed Health⌕ Search

Biomedical subjects

James Davis

Publications and source records attributed to James Davis.

At least 19 recordsLinked to original sources

Metabolic mimics: thiol responsive drug release.

A new approach to the design of selective release interfaces is assessed in which a hydrophobic component is functionalised with a receptor reactive toward reduced thiol peptides-principally glutathione. The assembly has been characterised using electrochemical techniques and its ability to form a coherent, water insoluble coating is demonstrated. The subsequent reaction with glutathione creates a supramolecular conjugate that exploits the hydrophilic nature of the amino acid chain as a route through which the protective coating can be eroded and hence the underlying substrate exposed. The efficacy of the release process has been critically assessed with a view to establishing the action and selectivity of the trigger mechanism.

Adamantane↗

Screening rates and characteristics of health plan members who respond to screening reminders.

INTRODUCTION: Preventive screening is widely recognized as a key component of cost-effective, high-quality health care. Even so, national screening for cancer, diabetes, and cholesterol falls far short of U.S. Preventive Services Task Force recommendations. Although evidence has shown that reminder programs improve preventive screening rates, this study is one of the first to examine the characteristics of health plan members who respond to screening reminders. METHODS: The study sample included active members of a large health plan in Hawaii who were identified by an algorithm as not having received one or more recommended screenings based on age and sex criteria (2000-2003) for breast cancer (n = 44,331), cervical cancer (n = 73,875), colon cancer (n = 131,860), diabetes (n = 86,216), and cholesterol (n = 54,843). Statistical analyses were conducted using Cox proportional hazard and logistic regression models. In the proportional hazard models, reminder letters were treated as time-varying exposures. Hazard ratios, or rate ratios, were used to examine the relationship between health plan member and physician characteristics and the likelihood of responding to the reminders. The effects of additional or multiple reminders among health plan members receiving more than one reminder were examined in multivariable regression models. RESULTS: The impact of health plan member characteristics and number of office visits on the response to reminders varied among the five health-screening types. Health plan members responded better to reminders for diabetes screening than for colon cancer screening. Members sent their second annual reminders were less likely to obtain screening than members sent their first reminder. Members receiving their third (or more) annual reminder were especially recalcitrant. CONCLUSION: Our findings suggest that the response to reminders differs according to patient characteristics. In particular, targeted interventions may be needed to encourage screening for younger and healthier members whose response rate to reminders was low. Further research is needed to determine how health plans can best reach members who do not respond to patient reminders.

Aged↗

The impact of seeing physicians new to a patient on the response to screening reminders.

BACKGROUND: A large insurer in Hawaii mails annual reminders to its members regarding recommended health screenings. This study examined the associations between the characteristics of physicians visited after the reminders were sent and the health screenings received for breast, cervical, and colorectal cancers, and for diabetes and cholesterol. METHODS: The study population included members identified as needing health screenings from 2000 to 2003 based on age and gender criteria. The study used a longitudinal design focusing on the 12 months after reminders were sent. Data were analyzed using logistic regression examining physician visits, other health services, and receipt of health screenings by 1-month intervals subsequent to the reminder mailings. RESULTS: In adjusted, multivariable models, members who saw physicians they had not seen in the past year had odds ratios for obtaining health screenings 6 to 8 times higher than members who only saw previously visited physicians. This enhanced response occurred among members receiving their first, second, and third (or subsequent) annual reminder letter. The more physicians that were visited and who were new to the members, the more likely the members were to obtain health screenings. CONCLUSIONS: Members seeing physicians they had not seen in the past year had significantly higher screening rates than the members only seeing physicians they had previously visited. The results suggest that healthcare screening may receive less attention at repeat visits with a physician than at visits with a physician who is new to a member.

Adult↗

A safety-net antibiotic prescription for otitis media: the effects of a PBRN study on patients and practitioners.

Pediatricians can decrease antibiotic use by treating acute otitis media (AOM) with a safety-net antibiotic prescription (SNAP). This study assessed whether the practitioners of the Practice-Based Research Network who participated in the study continued to use the SNAP and report a 60-day follow-up of the study patients. Charts were reviewed of study patients for 60 days following study enrollment. A survey on antibiotic use for AOM was mailed to the 17 study practitioners (SP) and 30 randomly selected community pediatricians (CP). Eight of the SP used the SNAP more than 20 times over the year following the study vs 1 of the CP. Sixty-two percent of patients never received antibiotics. The recurrence/relapse rate was greater in children younger than 2 years old compared to those older, 34% vs 10%. Practitioners who participate in a Practice-Based Research Network study are more likely to use a study intervention than others.

Anti-Bacterial Agents↗

Cathodic reduction of bisulfite and sulfur dioxide in aqueous solutions on copper electrodes: an electrochemical ESR study.

The electrochemical reduction of aqueous solutions of sulfite under acidic conditions on copper electrodes is reported, and a mechanism is proposed. Cyclic voltammetry at a copper disk suggests the operation of two reduction processes, the dominant process depending on solution pH. At very low pH (0-2), sulfur dioxide is reduced in a two-electron, two-proton reaction, but at higher pH (2-5), bisulfite is the electroactive species, being reduced by a single electron to ultimately yield the SO2*- radical anion. Simultaneous electrochemical electron spin resonance (ESR) measurements using a tubular flow cell support this proposal, and suggest that the radical anion is in equilibrium with dithionite, which is found to decay at low pH. Digisim modeling of the system is shown to be consistent with this mechanism over the experimental pH range.

Journal Article↗

Melanocortin subtype-4 receptor agonists containing a piperazine core with substituted aryl sulfonamides.

The biological activity for a set of melanocortin-4 receptor (MC4R) agonists containing a piperazine core with an ortho-substituted aryl sulfonamide is described. Compounds from this set had binding and functional activities at MC4R less than 30 nM. The most selective compound in this series was >25,000-fold more potent at MC4R than MC3R, and 490-fold more potent at MC4R than MC5R. This compound also reduced food intake after oral dosing at 25, 50, and 100 mg kg(-1) in fasted mice.

Animals↗

Surgical management of stress urinary incontinence: a questionnaire based survey.

OBJECTIVES: To determine the trends in the surgical management of urinary stress incontinence amongst members of the International Urogynaecology Association (IUGA). DESIGN: Postal Questionnaire Survey. METHODS: 530 members of the International Urogynaecology association were sent a postal questionnaire regarding their practice in the surgical management of urinary stress incontinence. We also collected data on the demographic profile of members and the preferred primary and secondary continence procedures. OUTCOME: Consensus in the surgical management of urinary stress incontinence amongst members of the IUGA. RESULTS: Five hundred and thirty questionnaires were sent to IUGA members worldwide. Two hundred and seventeen questionnaires were received of which fifteen were from physiotherapists, so were excluded from our analysis. The overall response rate was 41%, and the useable response rate was 38%. Of the total results analysed (two hundred and two), one hundred and twelve (54%) were from teaching hospital, sixty-two (31%) were from district general hospitals and twenty-eight (14%) were from members in private practice. The preferred primary continence procedure was Tension Free Vaginal Tape (TVT) in one hundred and thirty four (68%) respondents. The preferred secondary continence procedure was colposuspension or Trans obturator tape in twenty-six respondents each (13%). CONCLUSIONS: Almost all respondents (97.1%) were skilled at performing either TVT or colposuspension, which have been identified as the preferred methods of surgical management by the NICE (National Institute of Clinical Excellence, UK). Although colposuspension has been identified as the gold standard surgical procedure in the management of stress incontinence, 16% of respondents were not performing colposuspension. There appears to be little evidence base to the surgical techniques in the management of stress urinary continence.

Adult↗

Over-the-counter cold medications-postmortem findings in infants and the relationship to cause of death.

The Montgomery County Coroner's Office has encountered a series of 10 infant deaths over an 8-month period in infants under 12 months old with toxicology findings that include a variety of drugs commonly found in over-the-counter (OTC) cold medications. The drugs detected were ephedrine, pseudoephedrine, dextromethorphan, diphenhydramine, chlorpheniramine, brompheniramine, ethanol, carbinoxamine, levorphanol, acetaminophen, and the anti-emetic metoclopramide. Toxicology findings were confirmed in 2 different matrices in 9 of the 10 cases and by 2 different analytical methods. The blood concentrations of the drugs and the case histories, as well as the cause of death for each infant, if available, will be given. The majority of these deaths were either toxicity from the OTC cold medications directly or as a contributory factor in the cause of death. Only two of the cases were the result of possible child abuse. Caregivers may be under the mistaken notion that OTC cold medications formulated for children are also safe for use in infants. These cases demonstrate that not only is administration of some OTC cold medications not safe, but use of OTC cold medications in infants can result in toxicity that can lead to death.

Autopsy↗

Spacetime stereo: a unifying framework for depth from triangulation.

Depth from triangulation has traditionally been investigated in a number of independent threads of research, with methods such as stereo, laser scanning, and coded structured light considered separately. In this paper, we propose a common framework called spacetime stereo that unifies and generalizes many of these previous methods. To show the practical utility of the framework, we develop two new algorithms for depth estimation: depth from unstructured illumination change and depth estimation in dynamic scenes. Based on our analysis, we show that methods derived from the spacetime stereo framework can be used to recover depth in situations in which existing methods perform poorly.

Algorithms↗

Addressing oral health disparities in settings without a research-intensive dental school: collaborative strategies.

Research suggests that oral health is linked to systemic health, and those with poor oral health are potentially at greater risk for important diseases, including cardiovascular disease, stroke, diabetes mellitus, and adverse pregnancy outcomes. Asians and Pacific Islanders (APIs) in Hawaii have high rates of many such diseases. Studies in children in Hawaii have revealed disparities in dental health; for example, API children have significantly higher rates of cavities than other groups. Hence, conducting further study is vital in adults, particularly APIs, to assess oral health and its correlation to overall health outcomes. Given the lack of a dental school and the lack of fluoridated water in the state, the University of Hawaii's John A. Burns School of Medicine (ABSOM) has identified the need to assume a leadership role in creating effective community-based oral health research and treatment programs. With the support of the National Institute of Dental and Craniofacial Research, JABSOM fostered a collaborative relationship with the University of North Carolina at Chapel Hill School of Dentistry, a premiere research-intensive dental school, the Waimanalo Health Center, and the Hawaii State Department of Health. This partnership has worked together to implement a community-based approach to performing research designed to illuminate disparities and develop innovative strategies to promote oral health in Hawaii's diverse populations. We hope that this collaborative, culturally competent approach may serve as a model for use in other settings without a research-intensive dental school.

Adolescent↗

A health plan intervention to improve pneumococcal vaccination in the elderly.

In 1998, the Hawaii Medical Service Association, headquartered in Honolulu, partnered with a pharmaceutical manufacturer to promote pneumococcal immunization of its 33,017 Medicare cost-contract members. They disseminated newsletter articles, magazine advertisements, letters, posters, and broadcast announcements; held injection clinics; and provided physicians reminder postcards with patient labels. Medicare claims indicated that immunization rose by 13.3% in 1997, 20.7% in 1998, and 42.3% in 2000, exceeding rates in a fee-for-service control group. Moreover, the rate of hospitalization for pneumococcal pneumonia dropped after 1998. The data suggest that multimodal promotion of pneumococcal vaccine will result in more extensive immunization and less frequent hospitalization.

Aged↗

A comparison of different types of gold-carbon composite electrode for detection of arsenic(III).

A study has been conducted using abrasively modified basal and edge-plane graphite, carbon-paste, and carbon-epoxy electrodes to create gold-carbon composite electrodes. Using either nano or micro-sized gold particles their suitability for use in detecting arsenic(III) is assessed. It was found that gold arrays prepared from micron-sized particles gave the best performance for arsenic detection. In particular micron arrays produced in carbon-paste electrodes with an easily renewable surface work well for detection of arsenic, producing a detection limit of 5(+/-2)x10(-9) mol L(-1), with a high sensitivity of 10(+/-0.1) A mol(-1) L.

Journal Article↗

Regulation of protein catabolism by muscle-specific and cytokine-inducible ubiquitin ligase E3alpha-II during cancer cachexia.

The progressive depletion of skeletal muscle is a hallmark of many types of advanced cancer and frequently is associated with debility, morbidity, and mortality. Muscle wasting is primarily mediated by the activation of the ubiquitin-proteasome system, which is responsible for degrading the bulk of intracellular proteins. E3 ubiquitin ligases control polyubiquitination, a rate-limiting step in the ubiquitin-proteasome system, but their direct involvement in muscle protein catabolism in cancer remains obscure. Here, we report the full-length cloning of E3alpha-II, a novel "N-end rule" ubiquitin ligase, and its functional involvement in cancer cachexia. E3alpha-II is highly enriched in skeletal muscle, and its expression is regulated by proinflammatory cytokines. In two different animal models of cancer cachexia, E3alpha-II was significantly induced at the onset and during the progression of muscle wasting. The E3alpha-II activation in skeletal muscle was accompanied by a sharp increase in protein ubiquitination, which could be blocked by arginine methylester, an E3alpha-selective inhibitor. Treatment of myotubes with tumor necrosis factor alpha or interleukin 6 elicited marked increases in E3alpha-II but not E3alpha-I expression and ubiquitin conjugation activity in parallel. E3alpha-II transfection markedly accelerated ubiquitin conjugation to endogenous cellular proteins in muscle cultures. These findings show that E3alpha-II plays an important role in muscle protein catabolism during cancer cachexia and suggest that E3alpha-II is a potential therapeutic target for muscle wasting.

Amino Acid Sequence↗

Development of a disposable potentiometric sensor for the near patient testing of plasma thiol concentrations.

The reaction of naphthoquinone with physiological thiols has been investigated as the basis of a NPT strategy for the measurement of the latter. Screen-printed carbon electrode assemblies provide an inexpensive and inherently disposable platform for the detection methodology. The key analytical parameters underpinning the selective and sensitive (0.4 uM-1 mM) determination of reduced thiol have been assessed, and the clinical efficacy of the approach has been demonstrated through its application to the analysis of human plasma. The results have been corroborated using standard techniques, and the routes through which the system can be adopted within mainstream biomedical environments are highlighted.

Aged↗