Search PubMed⌕ Search

Biomedical subjects

P Davis

Publications and source records attributed to P Davis.

At least 37 records · Page 2Linked to original sources
PubMed2001

Successful allogeneic engraftment of mismatched unrelated cord blood following a nonmyeloablative preparative regimen.

Reduction in the toxicity of allogeneic transplantation with nonmyeloablative induction regimens has expanded the scope of practice to older and more debilitated patients. However, the limited availability of matched sibling donors requires that alternative donor sources be investigated. Reported here are 2 cases of patients with advanced hematologic malignancies without matched siblings, partially matched family members, or matched unrelated donors who successfully underwent nonmyeloablative conditioning therapy followed by infusion of partially matched, unrelated-donor cord blood cells. The patients are in remission and remain 100% donor as assessed by short tandem repeat analysis of the marrow 6 and 12 months following transplantation.

Adult↗
PubMed2001

Complete genome sequence of a multiple drug resistant Salmonella enterica serovar Typhi CT18.

Salmonella enterica serovar Typhi (S. typhi) is the aetiological agent of typhoid fever, a serious invasive bacterial disease of humans with an annual global burden of approximately 16 million cases, leading to 600,000 fatalities. Many S. enterica serovars actively invade the mucosal surface of the intestine but are normally contained in healthy individuals by the local immune defence mechanisms. However, S. typhi has evolved the ability to spread to the deeper tissues of humans, including liver, spleen and bone marrow. Here we have sequenced the 4,809,037-base pair (bp) genome of a S. typhi (CT18) that is resistant to multiple drugs, revealing the presence of hundreds of insertions and deletions compared with the Escherichia coli genome, ranging in size from single genes to large islands. Notably, the genome sequence identifies over two hundred pseudogenes, several corresponding to genes that are known to contribute to virulence in Salmonella typhimurium. This genetic degradation may contribute to the human-restricted host range for S. typhi. CT18 harbours a 218,150-bp multiple-drug-resistance incH1 plasmid (pHCM1), and a 106,516-bp cryptic plasmid (pHCM2), which shows recent common ancestry with a virulence plasmid of Yersinia pestis.

Chromosome Mapping↗
PubMed2001

Genome sequence of Yersinia pestis, the causative agent of plague.

The Gram-negative bacterium Yersinia pestis is the causative agent of the systemic invasive infectious disease classically referred to as plague, and has been responsible for three human pandemics: the Justinian plague (sixth to eighth centuries), the Black Death (fourteenth to nineteenth centuries) and modern plague (nineteenth century to the present day). The recent identification of strains resistant to multiple drugs and the potential use of Y. pestis as an agent of biological warfare mean that plague still poses a threat to human health. Here we report the complete genome sequence of Y. pestis strain CO92, consisting of a 4.65-megabase (Mb) chromosome and three plasmids of 96.2 kilobases (kb), 70.3 kb and 9.6 kb. The genome is unusually rich in insertion sequences and displays anomalies in GC base-composition bias, indicating frequent intragenomic recombination. Many genes seem to have been acquired from other bacteria and viruses (including adhesins, secretion systems and insecticidal toxins). The genome contains around 150 pseudogenes, many of which are remnants of a redundant enteropathogenic lifestyle. The evidence of ongoing genome fluidity, expansion and decay suggests Y. pestis is a pathogen that has undergone large-scale genetic flux and provides a unique insight into the ways in which new and highly virulent pathogens evolve.

Animals↗
PubMed2001

Phytoestrogen consumption and breast cancer risk in a multiethnic population: the Bay Area Breast Cancer Study.

Research on the relation between phytoestrogens and breast cancer risk has been limited in scope. Most epidemiologic studies have involved Asian women and have examined the effects of traditional soy foods (e.g., tofu), soy protein, or urinary excretion of phytoestrogens. The present study extends this research by examining the effects of a spectrum of phytoestrogenic compounds on breast cancer risk in non-Asian US women. African-American, Latina, and White women aged 35-79 years, who were diagnosed with breast cancer between 1995 and 1998, were compared with women selected from the general population via random digit dialing. Interviews were conducted with 1,326 cases and 1,657 controls. Usual intake of specific phytoestrogenic compounds was assessed via a food frequency questionnaire and a newly developed nutrient database. Phytoestrogen intake was not associated with breast cancer risk (odds ratio = 1.0, 95% confidence interval: 0.80, 1.3 for the highest vs. lowest quartile). Results were similar for pre- and postmenopausal women, for women in each ethnic group, and for all seven phytoestrogenic compounds studied. Phytoestrogens appear to have little effect on breast cancer risk at the levels commonly consumed by non-Asian US women: an average intake equivalent to less than one serving of tofu per week.

Adult↗
PubMed2001

Analysis of Gq protein alpha subunit mRNA expression in human monocytes: relevance of the purification step.

BACKGROUND: Galphaq is a member of the Gq family of G proteins, which by stimulating the phospholipase Cbeta (PLCbeta)-IP(3)-Ca(++) mediated intracellular signaling systems controls some of the most fundamental cardiovascular cellular processes. The study of Galphaq is complicated by the presence of a pseudogene in human DNA, with signficant homology to the mRNA encoding the alpha subunit of Gq protein. The presence of this pseudogene will cause problems when the analysis of the Galphaq gene expression is based solely on RT-PCR. In this study, we report a simple method for avoiding unwanted amplification of the Galphaq pseudogene and the use of human monocytes as a readily available source for examining Galphaq. METHODS: RT-PCR was carried out on RNA extracted from peripheral blood monocytes of 10 normal subjects using specific primers for Galphaq. RESULTS: When several subjects' Galphaq was examined, the authentic Galphaq mRNA amplification product levels, as a ratio to unpurified pseudogene containing amplification products, declined by up to approximately 70%. CONCLUSION: Given the importance of Gq protein in cardiovascular signal transduction, it is fundamental to provide a reliable assessment of G alpha q gene expression. In addition to accurately assessing Galphaq levels, the use of circulating human monocytes as a useful source of Galphaq for investigating mechanisms involved in the regulation of vascular tone is shown.

Base Sequence↗
PubMed2001

Enteral human IgG for prevention of necrotising enterocolitis: a placebo-controlled, randomised trial.

BACKGROUND: Neonatal necrotising enterocolitis is a serious, commonly fatal disease in premature neonates. Although feeding with expressed breast milk and other good nursery practices are partly protective, preventive measures are needed. Treating neonates enterally with a mixture of human IgA and IgG, prepared from donated blood, has been claimed to protect against necrotising enterocolitis. However, no IgA preparation is available in Australia. Our aim, therefore, was to identify whether or not enteral IgG could prevent the disorder. METHODS: We did a multicentre, double-blind, placebo- controlled trial. We randomly assigned 768 infants to receive human IgG 1200 mg/kg daily, and 761 to receive placebo, for up to 28 days. Treatment began at the same time as enteral feeding. The primary outcome measure was the proportion of infants who developed definite necrotising enterocolitis during the trial, and any deaths that resulted from the disorder in the treatment and placebo groups. Analysis was on an intention-to-treat basis. FINDINGS: 43 infants developed definite necrotising enterocolitis in the IgG group, ten of whom died. In the placebo group, 41 infants contracted the disorder and six died (p=0.47). 25 infants on IgG and 36 on placebo had suspect necrotising enterocolitis (p=0.14). INTERPRETATION: Supplementation of enteral feeds with human IgG does not reduce necrotising enterocolitis.

Double-Blind Method↗
PubMed2001

Long-term effects of indomethacin prophylaxis in extremely-low-birth-weight infants.

BACKGROUND: The prophylactic administration of indomethacin reduces the frequency of patent ductus arteriosus and severe intraventricular hemorrhage in very-low-birth-weight infants (those with birth weights below 1500 g). Whether prophylaxis with indomethacin confers any long-term benefits that outweigh the risks of drug-induced reductions in renal, intestinal, and cerebral blood flow is not known. METHODS: Soon after they were born, we randomly assigned 1202 infants with birth weights of 500 to 999 g (extremely low birth weight) to receive either indomethacin (0.1 mg per kilogram of body weight) or placebo intravenously once daily for three days. The primary outcome was a composite of death, cerebral palsy, cognitive delay, deafness, and blindness at a corrected age of 18 months. Secondary long-term outcomes were hydrocephalus necessitating the placement of a shunt, seizure disorder, and microcephaly within the same time frame. Secondary short-term outcomes were patent ductus arteriosus, pulmonary hemorrhage, chronic lung disease, ultrasonographic evidence of intracranial abnormalities, necrotizing enterocolitis, and retinopathy. RESULTS: Of the 574 infants with data on the primary outcome who were assigned to prophylaxis with indomethacin, 271 (47 percent) died or survived with impairments, as compared with 261 of the 569 infants (46 percent) assigned to placebo (odds ratio, 1.1; 95 percent confidence interval, 0.8 to 1.4; P=0.61). Indomethacin reduced the incidence of patent ductus arteriosus (24 percent vs. 50 percent in the placebo group; odds ratio, 0.3; P<0.001) and of severe periventricular and intraventricular hemorrhage (9 percent vs. 13 percent in the placebo group; odds ratio, 0.6; P=0.02). No other outcomes were altered by the prophylactic administration of indomethacin. CONCLUSIONS: In extremely-low-birth-weight infants, prophylaxis with indomethacin does not improve the rate of survival without neurosensory impairment at 18 months, despite the fact that it reduces the frequency of patent ductus arteriosus and severe periventricular and intraventricular hemorrhage.

Blindness↗
PubMed2001

Adverse events regional feasibility study: methodological results.

AIMS: To assess the feasibility of research into the occurrence, causation and prevention of adverse events (AEs) in New Zealand public hospitals. METHODS: A two-stage retrospective review was carried out on 1,575 medical records selected by systematic list sample from admissions for 1995 in three public hospitals in the Auckland region. Following initial screening, medical records were subject to structured implicit review using a standardised protocol. Feasibility measures, using international benchmarks where possible, were: adequacy of sample selection; completeness of medical records; reliability and validity of screener and reviewer judgements; internal consistency and face validity of AE determination and preventability assessment. RESULTS: The sample selection procedure was effective, although nearly 10% of records could not be secured. Information in medical records was sufficient for the identification and analysis of AEs. Adequate levels of agreement were achieved for screener and reviewer judgements, with kappa scores ranging between 0.302 and 0.622 and positive predictive values between 50.0% and 89.7%. The criteria for AE determination showed internal consistency and face validity, as did those for preventability. CONCLUSIONS: Research into the occurrence, causation and prevention of AEs in New Zealand health care settings is methodologically feasible and meets international benchmark standards.

Algorithms↗
PubMed2001

Adverse events regional feasibility study: indicative findings.

AIMS: To identify substantive findings of potential clinical and managerial significance from a regional feasibility study of adverse events (AEs). METHODS: A standardised protocol using structured implicit review was applied to 142 AEs generated in an audit study of three public hospitals in the Auckland region for admissions in 1995. Areas of potential significance addressed were: timing, location and impact of AEs; preventability; and clinical context and predictability. RESULTS: 142 cases were identified as AEs (10.7% of 1,326 screened records). In 102 cases, 7.7% of all screened records, it was considered to be more likely than not that health care management contributed to the AE. About half the reported AEs occurred before the index admission, the majority outside hospital. Over half of all events resulted in disability that was resolved within a month. An average 6.7 extra days stay in hospital were attributable to AEs. For 60% of AEs the evidence for preventability was either low or nonexistent. Areas of potential prevention were predominantly educational. Over half of all AEs occurred in a surgical context. Medical AEs were more likely to have occurred outside hospital, to be drug-related, to be associated with an acute admission, to be classified as highly preventable, and to have a greater impact on hospital stay. CONCLUSIONS: Although the data generated by a feasibility study must be treated with caution, the pattern of results is consistent with comparable Australian findings and is of potential clinical and managerial significance.

Drug-Related Side Effects and Adverse Reactions↗
PubMed2001

Dope: a love story.

Explore the source record for details and available documents.

Anecdotes as Topic↗
PubMed2001

Effect of N-alkyl and N-alkenyl substituents in noroxymorphindole, 17-substituted-6,7-dehydro-4,5alpha-epoxy-3,14-dihydroxy-6,7:2',3'-indolomorphinans, on opioid receptor affinity, selectivity, and efficacy.

The N-alkyl analogues (N-ethyl through N-heptyl), branched N-alkyl chain analogues (N-isopropyl, N-2-methylpropyl, and N-3-methylbutyl), and N-alkenyl analogues ((E)-N-3-methylallyl (crotyl), N-2-methylallyl, and N-3,3-dimethylallyl) were prepared in the noroxymorphindole series (17-substituted-6,7-dehydro-4,5alpha-epoxy-3,14-dihydroxy-6,7:2',3'-indolomorphinans), and the effect of the N-substituent on opioid receptor affinity, selectivity, and efficacy was examined using receptor binding assays, [(35)S]GTPgammaS efficacy determinations, and smooth muscle functional assays (electrically stimulated mouse vas deferens and guinea pig ileum). All of the compounds acted as opioid antagonists, including those with N-substituents which usually confer either weak agonist-antagonist behavior (N-ethyl) or potent opioid agonist activity (N-pentyl) in morphinan-like ligands which interact with the mu-receptor. Several N-substituted noroxymorphindoles were found to be more mu/delta-selective than naltrindole (NTI). The N-2-methylallylnoroxymorphindole, in particular, was found to be more selective than NTI in receptor binding assays (mu/delta = 1700 vs 120; kappa/delta = 810 vs 140), as an antagonist in the GTPgammaS assay (mu/delta = 170 vs 140; kappa/delta = 620 vs 160), and considerably more selective than NTI in the functional assays (mu/delta > 2200 vs 90). It also had high affinity for the delta-opioid receptor (K(i) = 4.7 nM in the binding assay) and high antagonist potency (1.2 nM in the GTPgammaS assay; 8.9 nM in the MVD assay).

Animals↗
PubMed2001

Biological properties of Phe(o)-opioid peptide analogues.

Biological properties of new analogues, which represent Phe(o)-propeptides of a variety of opioid peptides, are described. All Phe(o)-opioid analogues expressed both receptor binding affinities and in vitro biological activities at least at the level of the primary opioid peptides. Surprisingly, some of the propeptides expressed slightly higher activity than the primary opioid peptides. Nevertheless, no significant shift in receptor selectivity was observed, which indicate that these Phe(o)-analogues undoubtedly are propeptides. The possible role of membrane proteolytic enzymes associated with opioid receptors in transformation of propeptides is discussed.

Amino Acid Sequence↗
PubMed2001

Continuing medical education, needs assessment, and program development: theoretical constructs.

Continuing medical education (CME) program development and needs assessment have historically been practiced within the tradition of Ralph Tyler's education model. In light of transformational social, political, economic, and technical forces that demand greater account-ability and responsiveness from physicians, CME units are challenged to transform their cultures and structures from models that deliver education to models that support the facilitation of learning for enhanced competence and performance. This article describes key change forces for physicians and brings program development and needs assessment into focus for the discussion. The impact of change forces on program development and needs assessment are examined, and some techniques to move beyond the traditional approach of felt needs are presented as a way of enabling strategic administrative planning and change management.

Curriculum↗
PubMed2001

Community-based cancer screening for underserved women: design and baseline findings from the Breast and Cervical Cancer Intervention Study.

BACKGROUND: Underutilization of breast and cervical cancer screening has been observed in many ethnic groups and underserved populations. Effective community-based interventions are needed to eliminate disparities in screening rates and thus to improve prospects for survival. METHODS: The Breast and Cervical Cancer Intervention Study was a controlled trial of three interventions in the San Francisco Bay Area from 1993 to 1996: (1) community-based lay health worker outreach; (2) clinic-based provider training and reminder system; and (3) patient navigator for follow-up of abnormal screening results. Study design and a description of the interventions are reported along with baseline results of a household survey conducted in four languages among 1599 women, aged 40-75. RESULTS: Seventy-six percent of women ages 40 and over had had at least one mammogram, and most had had a clinical breast examination (88%) and Pap smear (89%). Rates were significantly lower for non-English-speaking Latinas and Chinese women (56 and 32%, respectively, for mammography), and maintenance screening (three mammograms in the past 5 years) varied from 7% (non-English-speaking Chinese) to 53% (Blacks). Pap smear screening in the past 3 years was low among non-English-speaking Latinas (72%) and markedly lower among non-English-speaking Chinese women (24%). The strongest predictors of screening behavior were having private health insurance and frequent use of medical services. Having a regular clinic and speaking English were also important. Race/ethnicity, education, household income, and employment status were, overall, not significant predictors of screening behavior. CONCLUSIONS: These baseline results support the importance of cancer screening interventions targeted to persons of foreign origin, particularly those less acculturated.

Adult↗
PubMed2001

A prospective evaluation of the awareness, knowledge, risk factors and current treatment of osteoporosis in a cohort of elderly subjects.

This was a prospective cohort study of 145 seniors attending a senior's clinic and social day program using a self-administered questionnaire. Its objective was to evaluate the awareness, knowledge, risk factors and current treatment of osteoporosis in our two patient groups. A secondary objective was to determine differences between the two cohorts, and between men and women. Participants included 39 men and 106 women, with an average age of 76 years. Of these, 89% were aware of osteoporosis and 61% gave the correct definition. Awareness and accurate definition were less in men compared with women (p < 0.01, and p < 0.05) and clinic compared to day program groups (p < 0.01). Only 54% of men knew osteoporosis could affect them. Television, newspapers and friends were identified as the main source of information. Physicians ranked as fifth as a source of information. In all, 84% knew diet was important. Prevalence of risk factors other than age were < 20%, except for senescence (38%) and alcohol use (40%). Utilization of specific therapies for osteoporosis was only 18% overall with a rate of 3% in men (p < 0.01). In women, 50% and were taking calcium supplements compared with 15% men (p < 0.001) and for multivitamins the figures were 57% and 33% respectively (p < 0.05). These results show a high level of awareness and correct definition of osteoporosis in this cohort of patients. Specific therapy for prevention or treatment of osteoporosis was inappropriately low in the face of high risk. This study highlights the care gap in osteoporosis in seniors and the need for increased physician involvement in patient education and treatment. Proactive treatment requests from patients need to be encouraged, especially with the future demographic shift.

Absorptiometry, Photon↗
PubMed2001

Performance anxiety: loss of the spoken edge.

The study aimed to assess whether a specific training program in vocal and physical skills could reduce the level of perceived performance anxiety. Eighteen undergraduate performing arts students were divided into two even groups. The experimental group experienced 10 two-hour sessions in a specialized vocal and physical skills training program. The control group received the same number of sessions in text analysis by the same teacher. Ten weeks after the training period, both groups were videotaped delivering a short speech of general interest. The videotaped material was assessed by four judges, using a visual analog scale (VAS). Perceptual variables considered were eight vocal and physical features: physical ease, physical presence, effective gesture use, effective eye contact, correct breath use, suitable pace, vocal variety, speech clarity, and one performance feature: perceived performance anxiety. Results indicated that the particular vocal and physical skills training program used showed positive results in effectively reducing the level of perceived performance anxiety. The experimental group scored significantly higher on each of the eight vocal and physical features and significantly lower on the perceived anxiety feature than the control group. This research has implications for those affected by performance anxiety in vocal presentation.

Adolescent↗
PubMed2001

A Canadian faculty of medicine and dentistry's survey of career development needs.

INTRODUCTION: Career development efforts for adult learners are more likely to succeed if they are responsive to the learners' needs, offered at convenient times, and provided in a variety of forms. METHODS: The Faculty of Medicine and Dentistry at the University of Alberta conducted a self-administered career development needs survey of full-time academic faculty. Faculty members were asked to identify how useful each of 35 career development skills would be to them and at which stage in an academic career it would be most useful. Preferred educational modes and times of delivery were also assessed. The mean rankings of skill needs were examined overall as well as by gender, academic rank, departmental category (clinician versus basic scientist), marital status, and the presence of school-aged children at home. RESULTS: 185 of 446 (41%) mailings were returned, of which 181 were evaluated. The number one perceived career development need across all subgroups was 'Effective writing of grants and publications'. Six of the top 10 needs were identified as useful at all career stages. Significant differences in rankings of needs were noted between subgroups. Half days were preferred to full days for career development efforts and short courses to other educational modes. DISCUSSION: Several career development skills were identified as priorities independently of gender, academic rank, and clinical versus basic science career tracks. Differences suggest that within a basic global programme, a variety of career development modules may need to be developed for subgroups.

Alberta↗