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Biomedical subjects

David W Wright

Publications and source records attributed to David W Wright.

At least 37 records · Page 2Linked to original sources
PubMed2005

Screening of combinatorial Peptide libraries for nanocluster synthesis.

A significant challenge in bionanotechnology is the discovery of effective biological interfaces that allow inorganic nanoscale materials to mimic effectively their biological counterparts. Much like de novo design of proteins, the rational design of such interfaces is a daunting task. An alternative approach is to screen libraries of peptides, inspired by known biological examples of such hybrid protein-material interfaces, for peptide ligands capable of not only stabilizing a size-discrete population of nanoclusters, but providing the requisite biological compatibility. The protocol described in this chapter is an approach for the simultaneous screening of spatially addressable combinatorial libraries for the stabilization of a variety of metal sulfide, metal oxide, and zero-valent nanoclusters. Additionally, the screening process allows the researcher to characterize the resulting nanoclusters in terms of a variety of physical properties. Ultimately, an informatics structure-function analysis may be performed in order to elucidate specific properties of the ligand sets, which provides access to certain desired material characteristics.

Animals↗
PubMed2004

Amine-terminated dendrimers as biomimetic templates for silica nanosphere formation.

In diatoms, silica synthesis occurs by use of complex posttranslationally modified peptides, termed silaffins, and highly complex biological polyamine structures. Silaffin peptides have lysine residues that are modified to long-chain polyamine moieties of N-methyl derivatives of polypropylenimine to drive silica synthesis at slightly acidic pH conditions. Using polypropylenimine (PPI) and PAMAM amine-terminated dendrimers as a biomimetic analogue of the polyamine modifications of silaffins, we have demonstrated the condensation of silica nanospheres. We have shown that the dendrimers react in an amine concentration-dependent fashion yielding silica nanospheres with a distinct size distribution reminiscent of the structures produced from both the modified and nonmodified peptides extracted from diatoms. Additionally, the templates were encapsulated by the growing nanospheres and precipitated from solution in a manner similar to that previously described for the bioactive peptides and polyamines.

Amines↗
PubMed2004

National practice guidelines for mental health care: a comparative policy analysis of the United kingdom and the United States.

Mental disorders are the leading cause of disability worldwide, according to the World Health Organization (WHO, 1996). In a report on health indicators of premature death and disability, the World Bank concluded that mental health problems account for 8.1% of the global burden of disease (GBD). Industrialized nations have taken different approaches in applying innovations to mental health care and mental health care policy. This paper uses the K. McInnis-Dittrich model of policy analysis (Ginsberg, 1994) to analyze the approaches of the United Kingdom (U.K.) and the United States (U.S.) to mental health treatment, specifically examining the effects of the U.K.'s national practice guidelines and the U.S.'s lack of similar guidelines. Recommendations for changes in current U.S. mental health policy are presented.

Health Planning Guidelines↗
PubMed2004

Proxy identification: a time-dependent analysis.

OBJECTIVES: To describe the availability of next-of-kin (NOK) for proxy consent over the 24-hour time period following presentation of major trauma patients to a Level I trauma center. METHODS: The study was conducted by using a prospective, observational study design. Consecutive patients meeting predefined major trauma criteria during a three-month study period were enrolled and followed until NOK were contacted, or up to 24 hours. Survival analysis was used to determine the probability of NOK contact during the 24-hour follow-up period. RESULTS: Three hundred fifty (92%) of 382 subjects had NOK contacted during the follow-up period. The probabilities (95% confidence intervals [CIs]) of NOK contact at the time of arrival (t = 0) and 2, 4, 6, and 24 hours postpresentation were 0.25 (95% CI = 0.21 to 0.30), 0.68 (95% CI = 0.63 to 0.72), 0.77 (95% CI = 0.73 to 0.82), 0.80 (95% CI = 0.76 to 0.84), and 0.87 (95% CI = 0.84 to 0.90), respectively. The median time to contact was 40 minutes (95% CI = 27 to 54 min). CONCLUSIONS: One third of the trauma patients in this study did not have NOK available two hours following arrival in the emergency department. For time-critical research protocols, the time to NOK contact can significantly impact the ability to ensure prompt enrollment and treatment in clinical trials. Further studies are needed to assess the generalizability and consistency of these data.

Adult↗
PubMed2004

Shedding new light on the "safe" club drug: methylenedioxymethamphetamine (ecstasy)-related fatalities.

OBJECTIVES: To report the pathology, toxicology, cause, and manner of death in 3,4-methylenedioxymethamphetamine (MDMA)-associated fatalities in the United States. Although use trends are increasing, data regarding the hazards of MDMA are limited. METHODS: The authors obtained fatality reports from participating medical examiners in the United States. Cases were identified as "drug-unrelated" when MDMA did not directly cause death (e.g., motor vehicle collision); deaths from drug toxicity were judged "drug-related." RESULTS: Thirty-eight (8%) of the surveyed medical examiners reported 102 deaths associated with MDMA use from 1999 to 2001. Ten percent of fatalities occurred in 1999 and 90% thereafter, representing a 400% relative increase. Victims tended to be young (mean age = 25), white (n = 87 [85%]), male (n = 70 [69%]), and otherwise healthy. Seventy-one (70%) deaths were drug-related (DR) and 31 (30%) were drug-unrelated (DU). Twenty-four (35%) DR deaths had a mean delay of 6.7 hours (95% CI = 5.1 to 8.2) in activating emergency medical services. Fifty-five DR cases (81%) were found in asystole and pronounced dead at the scene. CONCLUSIONS: The MDMA-associated fatal events typically occur in young, otherwise healthy individuals. MDMA's impact on the public health and safety of young adults and teenagers needs further assessment.

Adolescent↗
PubMed2003

Metalloporphyrin probes for antimalarial drug action.

Metal-substituted protoporphyrin IXs (Co(III)PPIX (1), Cr(III)PPIX (2), Mn(III)PPIX (3), Cu(II)PPIX (4), Mg(II)PPIX (5), Zn(II)PPIX (6) and Sn(IV)PPIX (7)), phthalocyanine tetrasulfonates (PcS (8) and Ni(II)PcS (9)), and anionic and cationic porphyrins (meso-tetra(4-sulfonatophenyl)porphine (TPPS4, 10), meso-tetra(4-carboxyphenyl)porphine (TPPC4, 11), tetrakis(4-N-trimethylaminophenyl)porphine (TMAP, 12) and meso-tetra(N-methyl-4-pyridyl)porphine (TMPyP4, 13)) have been used as probes to compare two different assays for the inhibition of beta-hematin formation. The results demonstrate that the efficacy of these probes in either the beta-hematin inhibition assay (9, 7, 6, 5>4>11, 3>10, 8>2, 1; 12 and 13 did not inhibit.) or the bionucleating template assay (8>1>11>9, 2>4>3>7>10>5>6; 12 and 13 did not inhibit.) differ significantly. These differences are examined in light of possible interactions between the inhibitor probes, heme, beta-hematin and the bionucleating template. This detailed analysis highlights the fact that while dominant modes of interactions may be occasionally identified, the precise mechanism of inhibition undoubtedly consists of the interplay between multiple interactions.

Antimalarials↗