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David Henry

Publications and source records attributed to David Henry.

At least 19 recordsLinked to original sources
PubMed2007

A randomized, double-blind study of pegylated liposomal doxorubicin for the treatment of AIDS-related Kaposi's sarcoma.

BACKGROUND: Despite a decreased incidence of AIDS-related Kaposi's sarcoma (KS) due to the advent of highly active antiretroviral therapy, approximately 15% of AIDS patients still develop AIDS-related KS. This study evaluated the clinical benefit, tumor response, and safety of pegylated liposomal doxorubicin for the treatment of AIDS-related KS. METHODS: This was a double-blind, multicenter study that randomized patients with AIDS-related KS to six cycles of pegylated liposomal doxorubicin (20 mg/m2; n = 60) or liposomal daunorubicin (40 mg/m2; n = 19) every 2 weeks. Clinical benefit was assessed using patient questionnaires and monitoring of KS-associated symptoms. Tumor responses were assessed using imaging techniques, direct measurement of skin lesions, and photographs, when possible. RESULTS: Clinical benefit was observed in 48/60 patients (80%) receiving pegylated liposomal doxorubicin and was maintained for a median of 62 days (range, 28-107 days). Clinical benefit was achieved by 12/19 patients (63.2%) receiving liposomal daunorubicin and was maintained for a median of 55 days (range, 28-84 +days). Clinical benefit correlated with tumor response. Tumor responses were achieved by 55.0% of patients receiving pegylated liposomal doxorubicin and 31.6% of patients receiving liposomal daunorubicin. Response rates were similar within each treatment group when only those patients without changes in antiretroviral therapy during treatment were considered. Adverse events associated with pegylated liposomal doxorubicin were neutropenia (30%), nausea (28.3%), and asthenia (16.7%). CONCLUSIONS: Pegylated liposomal doxorubicin is safe and effective for the treatment of AIDS-related KS, with most patients experiencing clinical benefit, tumor response, or both.

Acquired Immunodeficiency Syndrome↗
PubMed2006

Rapamycin is efficacious against primary effusion lymphoma (PEL) cell lines in vivo by inhibiting autocrine signaling.

The antitumor potency of the mTOR inhibitor rapamycin (sirolimus) is the subject of intense investigations. Primary effusion lymphoma (PEL) appears as an AIDS-defining lymphoma and like Kaposi sarcoma has been linked to Kaposi sarcoma-associated herpesvirus (KSHV). We find that (1) rapamycin is efficacious against PEL in culture and in a murine xenograft model; (2) mTOR, its activator Akt, and its target p70S6 kinase are phosphorylated in PEL; (3) rapamycin inhibits mTOR signaling as determined by S6 phosphorylation; (4) KSHV transcription is unaffected; (5) inhibition of IL-10 signaling correlates with drug sensitivity; and (6) addition of exogenous IL-10 or IL-6 can reverse the rapamycin growth arrest. This validates sirolimus as a new treatment option for PEL.

Animals↗
PubMed2006

Cardiovascular risk and inhibition of cyclooxygenase: a systematic review of the observational studies of selective and nonselective inhibitors of cyclooxygenase 2.

CONTEXT: Evidence that rofecoxib increases the risk of myocardial infarction has led to scrutiny of other nonsteroidal anti-inflammatory drugs (NSAIDs). Regulatory agencies have provided variable advice regarding the cardiovascular risks with older nonselective NSAIDs. OBJECTIVE: To undertake a systematic review and meta-analysis of controlled observational studies to compare the risks of serious cardiovascular events with individual NSAIDs and cyclooxygenase 2 inhibitors. DATA SOURCES: Searches were conducted of electronic databases (1985-2006), scientific meeting proceedings, epidemiological research Web sites, and bibliographies of eligible studies. STUDY SELECTION: Eligible studies were of case-control or cohort design, reported on cardiovascular events (predominantly myocardial infarction) with cyclooxygenase 2 inhibitor, NSAID use, or both with nonuse/remote use of the drugs as the reference exposure. Of 7086 potentially eligible titles, 17 case-control and 6 cohort studies were included. Thirteen studies reported on cyclooxygenase 2 inhibitors, 23 on NSAIDs, and 13 on both groups of drugs. DATA EXTRACTION: Two people independently extracted data and assessed study quality with disagreements resolved by consensus. DATA SYNTHESIS: Data were combined using a random-effects model. A dose-related risk was evident with rofecoxib, summary relative risk with 25 mg/d or less, 1.33 (95% confidence interval [CI], 1.00-1.79) and 2.19 (95% CI, 1.64-2.91) with more than 25 mg/d. The risk was elevated during the first month of treatment. Celecoxib was not associated with an elevated risk of vascular occlusion, summary relative risk 1.06 (95% CI, 0.91-1.23). Among older nonselective drugs, diclofenac had the highest risk with a summary relative risk of 1.40 (95% CI, 1.16-1.70). The other drugs had summary relative risks close to 1: naproxen, 0.97 (95% CI, 0.87-1.07); piroxicam, 1.06 (95% CI, 0.70-1.59); and ibuprofen, 1.07 (95% CI, 0.97-1.18). CONCLUSIONS: This review confirms the findings from randomized trials regarding the risk of cardiovascular events with rofecoxib and suggests that celecoxib in commonly used doses may not increase the risk, contradicts claims of a protective effect of naproxen, and raises serious questions about the safety of diclofenac, an older drug.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed2006

Cyclooxygenase-2 inhibitors and coronary occlusion--exploring dose-response relationships.

AIMS: To investigate the relationship between acute coronary syndrome (ACS) and ingested doses of selective cyclooxygenase-2 (COX-2) inhibitors and other nonsteroidal anti-inflammatory drugs (NSAIDs). METHODS: Case-control study, commenced August 2003. Cases were patients admitted to hospital with ACS (myocardial infarction/unstable angina). Controls were hospital patients admitted for reasons other than acute vascular ischaemia or conditions that are believed to be complications of treatment with COX-2 inhibitors or NSAIDs. Structured interviews were undertaken within 7 days of admission, collecting information on cardiovascular events and risk factors and all ingested drugs, including the doses of COX-2 inhibitors and NSAID consumed in the previous week and month. RESULTS: An interim analysis of the data was conducted in late 2004 to inform a review of the COX-2 inhibitors by the Australian drug regulatory agency. Between August 2003 and October 2004, we recruited 328 ACS cases and 478 controls. With non-use of COX-2 inhibitors or NSAIDs as the reference the adjusted odds ratios (OR) for ACS were: celecoxib 1.11 (95% confidence interval 0.59, 2.11), rofecoxib 0.63 (0.31, 1.28) and other NSAIDs 0.67 (0.41, 1.09). Among control subjects, median daily ingested doses of celecoxib and rofecoxib were 200 mg and 13.4 mg, respectively. Using these to stratify risk, adjusted ORs for ACS were: 'low' dose (< median) 0.44 (0.19, 1.03); 'high' dose (>/= median) 1.22 (0.67, 2.21). A test for interaction across doses was statistically significant, OR 2.8 (1.0, 7.7), suggesting that at low doses, COX-2 inhibitors may be protective, becoming risk-inducing only at higher doses. CONCLUSION: The possibility that the gradient of cardiovascular risk with COX-2 inhibitors runs from protective to risk-inducing has biological plausibility and merits further investigation.

Aged↗
PubMed2006

Family violence.

Family violence occurs in many forms; the most prominent are domestic violence, child abuse, and elder abuse. Family violence affects many persons at some point in their life and constitutes the majority of violent acts in our society. Although there has been considerable study of the patterns, risk factors, and interventions for each form of family violence, great controversy still exists within each area. There is growing recognition of an overlap in the patterns, causes, and effective interventions across types of family violence. There is also an increasing awareness of the value of greater integration of theory and research across areas into a family violence approach through an ecological perspective. This review focuses on current knowledge related to these problems and suggests integrative steps to advance knowledge.

Aged↗
PubMed2005

Ties that bind: multiple relationships between clinical researchers and the pharmaceutical industry.

BACKGROUND: It is believed that pharmaceutical industry sponsorship of clinical research leads to the development of multiple ties between clinicians and the pharmaceutical industry. To quantify this relationship we conducted a survey of medical specialists listed in the Medical Directory of Australia in 2002 and 2003. METHODS: A questionnaire was mailed that elicited information about all aspects of research relationships between clinicians and pharmaceutical companies. The odds of reporting multiple additional ties (financial and professional) with pharmaceutical companies by clinicians who had an active research relationship were compared with those who did not. All clinicians who returned a completed questionnaire about their research activities were included in the study. RESULTS: A questionnaire was mailed to 2120 medical specialists; 823 (39%) responded. Of these, 338 (41%) reported involvement in industry-sponsored research in the previous year. They were more likely than others to have been offered industry-sponsored items or activities valued at more than 500 AU dollars (>382 US dollars; odds ratio [OR], 3.5; 95% confidence interval [CI], 2.6-4.7) and support for attending international conferences (OR, 5.4; 95% CI, 3.9-7.4). The strongest associations were seen for acting as a paid consultant to industry (OR, 9.0; 95% CI, 3.9-20.4) and for membership on advisory boards (OR, 6.9; 95% CI, 5.1-9.6). There was a strong relationship between research collaboration and accumulation of industry ties. For 1 additional tie the OR was 2.2 (95% CI, 1.2-3.8) and rose to 6.3 (95% CI, 3.5-11.1) with 3 ties and 41.8 (95% CI, 14.5-143.4) with 6 or more ties. CONCLUSIONS: Medical specialists who have research relationships with the pharmaceutical industry are much more likely to have multiple additional ties than those who do not have research relationships. Institutional review should discourage clinical researchers from developing multiple ties.

Australia↗
PubMed2005

Assessing the impact of the Australia-United States Free Trade Agreement on Australian and global medicines policy.

On 1 January 2005, a controversial trade agreement entered into force between Australia and the United States. Though heralded by the parties as facilitating the removal of barriers to free trade (in ways not achievable in multilateral fora), it also contained many trade-restricting intellectual property provisions and others uniquely related to altering pharmaceutical regulation and public health policy in Australia. The latter appear to have particularly focused on the world-respected process of federal government reimbursement after expert cost-effectiveness evaluation, popularly known as the Pharmaceutical Benefits Scheme ('PBS'). It remains uncertain what sort of impacts--if any--the Australia-United States Free Trade Agreement ('AUSFTA') will have on PBS processes such as reference pricing and their important role in facilitating equitable and affordable access to essential medicines. This is now the field of inquiry for a major three year Australian Research Council ('ARC')-funded study bringing together a team of senior researchers in regulatory theory from the Australian National University and pharmacoeconomics from the University of Newcastle. The project proposes to monitor, assess and analyse the real and potential impacts of the AUSFTA in this area, providing Australian policy-makers with continuing expertise and options. To the extent that the AUSFTA medicines provisions may represent an important precedent in a global strategy by industry on cost-effectiveness evaluation of pharmaceuticals, the study will also be of great interest to policy makers in other jurisdictions.

Journal Article↗
PubMed2005

Empirical uncertainty and moral contest: a qualitative analysis of the relationship between medical specialists and the pharmaceutical industry in Australia.

Alliances between the medical profession and the pharmaceutical industry have become increasingly widespread in recent years. While there are clearly benefits for doctors and their patients derived from the medical profession working with industry, concern has arisen that the commercial imperative of industry may conflict with physicians' independence and professional integrity. This paper reports the findings of an in-depth interview study with 50 Australian medical specialists undertaken to explore how and why they interact with the pharmaceutical industry and to gain insight into specialists' moral evaluation of the relationship and its consequences. Analysis of the qualitative data led to the categorizing medical specialists into three types--Confident Engagers, Ambivalent Engagers and Avoiders--based on their descriptions and evaluations of their relationship. The majority of interviewees believed that some relationship with the pharmaceutical industry was inevitable, that there were both risks and benefits associated with the relationship and that as individuals they were competent in minimizing the risks and maximizing the benefits. However, their views diverged on the extent and magnitude of the risks and benefits. The data suggested that there is considerable variance in specialists' judgments of what constituted appropriate industry largesse. Specialists' relationship with the pharmaceutical industry has inherent tensions that are managed by different doctors in different ways. Moral evaluation of the relationship and its consequences varies and the ethical concerns surrounding the relationship appeared as an area of contest. The findings suggest that in developing normative guidelines for academic and professional practice, policy makers should recognise and account for the complexity of the relationship and for the variation in medical specialists' views and feelings.

Australia↗
PubMed2005

Sequence, annotation, and analysis of synteny between rice chromosome 3 and diverged grass species.

Rice (Oryza sativa L.) chromosome 3 is evolutionarily conserved across the cultivated cereals and shares large blocks of synteny with maize and sorghum, which diverged from rice more than 50 million years ago. To begin to completely understand this chromosome, we sequenced, finished, and annotated 36.1 Mb ( approximately 97%) from O. sativa subsp. japonica cv Nipponbare. Annotation features of the chromosome include 5915 genes, of which 913 are related to transposable elements. A putative function could be assigned to 3064 genes, with another 757 genes annotated as expressed, leaving 2094 that encode hypothetical proteins. Similarity searches against the proteome of Arabidopsis thaliana revealed putative homologs for 67% of the chromosome 3 proteins. Further searches of a nonredundant amino acid database, the Pfam domain database, plant Expressed Sequence Tags, and genomic assemblies from sorghum and maize revealed only 853 nontransposable element related proteins from chromosome 3 that lacked similarity to other known sequences. Interestingly, 426 of these have a paralog within the rice genome. A comparative physical map of the wild progenitor species, Oryza nivara, with japonica chromosome 3 revealed a high degree of sequence identity and synteny between these two species, which diverged approximately 10,000 years ago. Although no major rearrangements were detected, the deduced size of the O. nivara chromosome 3 was 21% smaller than that of japonica. Synteny between rice and other cereals using an integrated maize physical map and wheat genetic map was strikingly high, further supporting the use of rice and, in particular, chromosome 3, as a model for comparative studies among the cereals.

Arabidopsis↗
PubMed2005

What are the roles and responsibilities of the media in disseminating health information?

BACKGROUND TO THE DEBATE: In December 2004 three news stories in the popular press suggested that the side effects of single-dose nevirapine, which has been proven to prevent mother-to-child transmission of HIV, had been covered up. Many HIV experts believed that the stories were unwarranted and that they would undermine use of the drug, leading to a rise in neonatal HIV infection. The controversy surrounding these stories prompted the PLoS Medicine editors to ask health journalists, and others with an interest in media reporting of health, to share their views on the roles and responsibilities of the media in disseminating health information.

Ethics↗
PubMed2005

Effects of chemotherapy on endogenous erythropoietin levels and the pharmacokinetics and erythropoietic response of darbepoetin alfa: a randomised clinical trial of synchronous versus asynchronous dosing of darbepoetin alfa.

The introduction of longer-acting erythropoietic agents into the practice of oncology has demanded an understanding of the interaction of chemotherapy with the pharmacokinetics and haematological effects of these erythropoietins. We report results of a randomised trial comparing the haematological effects of darbepoetin alfa, 6.75 mug/kg, administered once every 3 weeks to anaemic cancer chemotherapy patients on either an asynchronous (day 15) or synchronous (day 1) schedule relative to their every-3-week chemotherapy. A total of 81 patients were randomised and received the study drug (43 asynchronous; 38 synchronous). No difference was observed between groups in the primary endpoint of mean haemoglobin change after 6 weeks of therapy (P=0.45) and change scores were similar to those observed with standard weekly darbepoetin alfa therapy. In a subset of patients evaluated with intensive pharmacokinetic sampling, an increase in endogenous erythropoietin concentration (up to 4-fold) lasting approximately 1 week following chemotherapy administration was observed in both groups. Synchronous administration of darbepoetin alfa was associated with a 1.3-fold increase in the area under the darbepoetin alfa concentration-time curve compared with asynchronous administration. Our data suggest that darbepoetin alfa is effective administered every 3 weeks regardless of timing of administration with respect to chemotherapy and that receptor-mediated uptake by the erythron may be an important clearance mechanism for erythropoietic proteins.

Adult↗
PubMed2005

Effect of angiotensin-converting enzyme or vasopeptidase inhibition on ventricular size and function in patients with heart failure: the Omapatrilat Versus Enalapril Randomized Trial of Utility in Reducing Events (OVERTURE) echocardiographic study.

BACKGROUND: Angiotensin-converting enzyme (ACE) inhibition attenuates ventricular remodeling and improves ventricular function in heart failure patients. Vasopeptidase inhibition has shown similar effects in experimental models. OBJECTIVES: The OVERTURE echocardiographic study was designed to test the hypothesis that the vasopeptidase inhibitor omapatrilat would attenuate ventricular remodeling and improve ventricular function to a greater extent than an ACE inhibitor. METHODS: Three hundred twenty-one patients with heart failure (New York Heart Association class > or = 2) were included in the OVERTURE echocardiographic substudy and were randomized to receive enalapril (10 mg twice a day) or omapatrilat (40 mg every day). Echocardiograms were performed at baseline and at 1 year (n = 214). Left ventricular size was estimated by summation of ventricular areas in apical and short-axis views and by calculation of ventricular volumes. Ejection fraction was calculated from ventricular volumes. RESULTS: Combined diastolic and systolic areas and volumes decreased significantly (mean diastolic area change -8.36 cm2, 95% CI -9.4 to -7.3 cm2; mean systolic change -8.4 cm2, 95% CI -9.5 to -7.3 cm2), and ejection fractions increased significantly (3.6%, 95% CI 2.6% to 4.6%) in both treatment groups from baseline to 1 year. There were no differences in the magnitude of improvement in ventricular size or function based on treatment assignment. Patients who died or were hospitalized for heart failure subsequent to the final assessment demonstrated the least degree of reverse remodeling. CONCLUSION: Ventricular size and function improved similarly after 1 year with ACE or vasopeptidase inhibition in patients with heart failure. Reverse remodeling was associated with improved outcome.

Aged↗
PubMed2005

Moral hazard and prescription medicine use in Australia--the patient perspective.

All Australian citizens are provided affordable access to prescription medicines through the nation's system of universal pharmaceutical subsidies--the pharmaceutical benefits scheme. The rapid increase in pharmaceutical related expenditure has generated the concern that Australians are taking advantage of prescription subsidies and are using more medicines than are necessary, thereby creating a 'moral hazard'. This concern is predicated on a number of assumptions about patient behaviour rather than on empirical observation. These assumptions amount to a view that patients are consumers who treat prescription medicines as common goods subject to informed and rational calculation of the cost and benefits of their use. This paper reports the findings of an in-depth interview study undertaken to explore how prescription cost influences Australians' medicine use. Qualitative data were analysed to compare medicine users' descriptions of the role of prescription cost in medicine use against the assumptions that underlie the belief in moral hazard. Moral hazard did not appear to be significantly operating in the accounts of medicine use collected for this study. Interviewees' accounts of medicine use revealed an act characterised by ambivalence, a mix of desire and antipathy, faith and suspicion. Medicines appeared in interviewees' accounts as both pharmacologically and symbolically potent substances, which despite their familiarity as objects, are often mysterious to non-expert patients. Cost appeared as a secondary factor in patients' decision to access a prescription medicine. Using a prescription was predicated on the medicine being necessary, with necessity typically established by an expert doctor prescribing the medicine. Prescription medicines did not appear as 'common goods' where subsidised access motivates a 'consumer' to demand more or make the prospect of prescription use more attractive or necessary.

Australia↗
PubMed2005

Standard of care for cancer-related anemia: improving hemoglobin levels and quality of life.

The introduction of recombinant human erythropoietin (rHuEPO) has proven to be a major advance in the therapeutic options available for managing anemia in cancer patients. The results of placebo-controlled clinical trials and large, community-based, open-label studies have confirmed that epoetin alfa, a recombinant human erythropoietin, significantly reduces transfusion requirements, and reliably increases hemoglobin (Hb) levels in anemic (Hb level <12 g/dl) cancer patients undergoing chemotherapy. Increased Hb improves patients' energy level and their ability to perform the activities of daily living, as well as their overall quality of life (QOL). These findings are independent of tumor type and disease status and are comparable in patients receiving nonplatinum- and platinum-based chemotherapeutic regimens. Furthermore, more than a decade of use in clinical trials and by physicians in routine clinical practice has demonstrated that epoetin alfa is safe and well tolerated when used to treat cancer patients with anemia. The availability of epoetin alfa as an alternative to transfusion has changed practices in anemia management; physicians can now treat anemia with the goal of achieving adequate Hb levels to relieve anemia-related fatigue, a major symptom contributing to decreased QOL in cancer patients. Incremental benefit analysis has shown that increasing Hb level from 11 g/dl to 12 g/dl yields the greatest improvement in QOL per 1 g/dl increase in Hb. The demonstrated efficacy of epoetin alfa for increasing Hb levels and improving patient QOL have made this agent a rationale choice for management of cancer-related anemia. Ongoing research will continue to provide new insights into best management of anemia with epoetin alfa in cancer patients.

Anemia, Hypochromic↗
PubMed2005

What's in store.

Explore the source record for details and available documents.

Commerce↗
PubMed2004

Systems for grading the quality of evidence and the strength of recommendations I: critical appraisal of existing approaches The GRADE Working Group.

BACKGROUND: A number of approaches have been used to grade levels of evidence and the strength of recommendations. The use of many different approaches detracts from one of the main reasons for having explicit approaches: to concisely characterise and communicate this information so that it can easily be understood and thereby help people make well-informed decisions. Our objective was to critically appraise six prominent systems for grading levels of evidence and the strength of recommendations as a basis for agreeing on characteristics of a common, sensible approach to grading levels of evidence and the strength of recommendations. METHODS: Six prominent systems for grading levels of evidence and strength of recommendations were selected and someone familiar with each system prepared a description of each of these. Twelve assessors independently evaluated each system based on twelve criteria to assess the sensibility of the different approaches. Systems used by 51 organisations were compared with these six approaches. RESULTS: There was poor agreement about the sensibility of the six systems. Only one of the systems was suitable for all four types of questions we considered (effectiveness, harm, diagnosis and prognosis). None of the systems was considered usable for all of the target groups we considered (professionals, patients and policy makers). The raters found low reproducibility of judgements made using all six systems. Systems used by 51 organisations that sponsor clinical practice guidelines included a number of minor variations of the six systems that we critically appraised. CONCLUSIONS: All of the currently used approaches to grading levels of evidence and the strength of recommendations have important shortcomings.

Advisory Committees↗