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Biomedical subjects

M Atkins

Publications and source records attributed to M Atkins.

At least 19 recordsLinked to original sources
PubMed2006

Exenatide: effect of injection time on postprandial glucose in patients with Type 2 diabetes.

AIMS: Exenatide is an incretin mimetic whose effect on glycaemic control in patients with Type 2 diabetes is currently under investigation. This study assessed the effect of injection time relative to a standardized meal on postprandial pharmacodynamics of exenatide in patients with Type 2 diabetes. METHODS: Eighteen patients participated in this single-centre, open-label, placebo-controlled, randomized, six-way crossover study. Patients received subcutaneous injections of either placebo (-15 min) or 10 microg of exenatide at -60, -15, 0, +30 or +60 min relative to a standardized breakfast meal on six consecutive days. Serial blood samples were assayed for plasma glucose and insulin concentrations. RESULTS: For all exenatide treatments, incremental postprandial glucose area under the postprandial plasma glucose curve from zero to 6 h (AUC0-6 h) was significantly reduced compared with placebo. When exenatide was administered before (-60, -15 min) or with the meal (0 min), peak postprandial glucose concentrations were significantly decreased (P < 0.0001 for all treatments) compared with placebo. Post-meal exenatide administration (+30, P < 0.05; +60 min, P = 0.21) resulted in smaller peak glucose reductions and in some patients transient low plasma glucose concentrations were reported. Peak plasma insulin concentrations in the pre-meal treatments were significantly lower than placebo (P < 0.05 for all treatments), while post-meal dosing groups exhibited a trend towards higher insulin peaks compared with placebo. The most common adverse events related to exenatide were headache, nausea, dyspepsia and vomiting, and were generally of mild-to-moderate intensity. CONCLUSIONS: In this study, all exenatide treatments demonstrated reductions in postprandial plasma glucose excursions compared with placebo. Pre-meal and with meal administration of exenatide produced greater reduction of postprandial glucose excursions compared with post-meal administration. These data support flexible dosing of exenatide at any time within 60 min before a meal.

Area Under Curve↗
PubMed2005

Ecological consequences of dredged material disposal in the marine environment: a holistic assessment of activities around the England and Wales coastline.

This study provides a holistic perspective on the ecological effects of dredged material disposal, both intertidally and subtidally. A number of numerical techniques (univariate, distributional, multivariate and meta-analysis) were used to assess impacts at 18 different disposal sites. The analyses revealed that ecological effects associated with dredged material disposal were dependent on the numerical techniques used, and that impacts were disposal-site specific. Disposal-site communities were generally faunistically impoverished to varying degrees, and impacts following intertidal placement were comparable to those of subtidal placement. We conclude that any assessment of the consequences of dredged material disposal to the coastal environment must take account of site-specific variation in prevailing hydrographic regimes and in ecological status, along with information on the disposal activity itself (mode, timing, quantity, frequency and type of material). As would be expected, variability in the latter presents a significant challenge in attempts to generalise about environmental and ecological impacts.

Animals↗
PubMed2005

ECT in depression.

Explore the source record for details and available documents.

Major Depressive Disorder↗
PubMed2003

An open-label study of tenofovir in HIV-1 and Hepatitis B virus co-infected individuals.

BACKGROUND: Tenofovir is a novel nucleotide analogue recommended for use in HIV-1 infected treatment-experienced patients. Recent data suggest an effect on Hepatitis B virus (HBV) replication. We therefore investigated the use of tenofovir in HIV-1 and HBV co-infected individuals. METHODS: Twenty HIV-1/HBV co-infected patients with a median of 108 weeks lamivudine experience (range, 0-270 weeks) received tenofovir 245 mg daily in addition to or as part of their combination antiretroviral therapy. Their immunologic parameters and HIV-1 RNA and HBV DNA viral loads were followed over a period of 52 weeks. In addition, their HBV DNA polymerase was sequenced at baseline to measure the frequency of YMDD mutations that are associated with lamivudine resistance. FINDINGS: A significant decrease in HBV DNA viral load (4 x log ) and alanine aminotransferase levels was observed. There were no significant overall differences between the lamivudine-experienced (n = 15) and -naive (n = 5) individuals and tenofovir was well tolerated. Five patients (25%) underwent HBe antigen seroconversion during the study period. Out of the 15 lamivudine-experienced individuals, 10 had YMDD mutations and one had YIDD mutations in HBV DNA. INTERPRETATION: These results indicate that 52 weeks of tenofovir in addition to antiretroviral therapy is active against HBV, and it appears to overcome lamivudine resistance.

Adenine↗
PubMed2002

New genomic resources for the honey bee(Apis mellifera L.): development of a deep-coverage BAC library and a preliminary STC database.

We have constructed a bacterial artificial chromosome (BAC) library for a European honey bee strain using the cloning enzyme HindIII in order to develop resources for structural genomics research. The library contains 36,864 clones (ninety-six 384-well plates). A random sampling of 247 clones indicated an average insert size of 113 kb (range = 27 to 213 kb) and 2% empty vectors. Based on an estimated genome size of 270 Mb, this library provides approximately 15 haploid genome equivalents, allowing >99% probability of recovering any specific sequence of interest. High-density colony filters were gridded robotically using a Genetix Q-BOT in a 4 x 4 double-spotted array on 22.5-cm2 filters. Screening of the library with four mapped honey bee genomic clones and two bee cDNA probes identified an average of 21 positive signals per probe, with a range of 7-38 positive signals per probe. An additional screening was performed with nine aphid gene fragments and one Drosophila gene fragment resulting in seven of the nine aphid probes and the Drosophila probe producing positive signals with a range of 1 to 122 positive signals per probe (average of 45). To evaluate the utility of the library for sequence tagged connector analysis, 1152 BAC clones were end sequenced in both forward and reverse directions, giving a total of 2061 successful reads of high quality. End sequences were queried against SWISS-PROT, insect genomic sequence GSS, insect EST, and insect transposable element databases. Results in spreadsheet format from these searches are publicly available at the Clemson University Genomics Institute (CUGI) website in a searchable format (http://www.genome.clemson.edu/projects/stc/bee/AM__Ba/).

Animals↗
PubMed2002

Day surgery and body mass index: results of a national survey.

In March 1992, the Royal College of Surgeons issued Guidelines for Day Case Surgery. Patients with a body mass index (BMI) > 30 were deemed unsuitable for operations to be performed as a day case. Since these guidelines were issued, many changes have occurred. Two years ago we successfully increased the BMI limit for patients undergoing general anaesthesia in our day surgery unit from 30 to 34. The success of this led us to question the current validity of the Royal College of Surgeons guidelines. A postal questionnaire was conducted surveying current practice in day surgical units within the UK. We achieved a 96% response rate. The results demonstrated a range of acceptable BMI values, with 85% of units anaesthetising patients with a BMI > 30. We conclude that many day case units routinely anaesthetise patients with BMI values > 30. Therefore, the current guidelines, which were issued 9 years ago, are no longer being adhered to nationally.

Ambulatory Surgical Procedures↗
PubMed2001

Outpatient biochemotherapy with interleukin-2 and interferon alfa-2b in patients with metastatic malignant melanoma: results of two phase II cytokine working group trials.

PURPOSE: The Cytokine Working Group performed a randomized phase II trial of two outpatient biochemotherapy regimens to identify an outpatient regimen with high antitumor activity and less toxicity than inpatient regimens which might be compared with chemotherapy or inpatient biochemotherapy regimens in future phase III trials. PATIENTS AND METHODS: Eighty-one patients with metastatic malignant melanoma received dacarbazine 250 mg/m(2)/d intravenously (IV) and cisplatin 25 mg/m(2)/d IV on days 1, 2, and 3, plus interferon (IFN) alfa-2b 5 mU/m(2) subcutaneously (SC) on days 6, 8, 10, 13, and 15, given every 28 days. Interleukin-2 (IL-2) was given daily on days 6 to 10 and 13 to 15. In group 1, IV IL-2 was given at 18.0 MU/m(2), and in group 2, SC IL-2 was given at 5.0 mU/m(2). RESULTS: In group 1 (IV IL-2), there were five complete responses (CRs) and 11 partial responses (PRs) among 44 patients (objective response rate [ORR], 36%; 95% confidence interval [CI], 22% to 51%). In group 2 (SC IL-2), there was one CR and five PRs among the 36 patients (ORR, 17%; 95% CI, 4% to 29%). The median survival was 10.7 months in group 1 and 7.3 months in group 2. Eleven patients in group 1 and four patients in group 2 remain alive as of the last follow-up. Toxicities in both groups were similar. No patient required hospitalization for neutropenic fever. CONCLUSION: Biochemotherapy has activity in these outpatient regimens with acceptable toxicity. The antitumor activity observed with the IV IL-2 regimen seems similar to that of inpatient biochemotherapy regimens. If inpatient biochemotherapy regimens develop an established role in the management of melanoma, future phase III trial comparisons with this outpatient IV IL-2 regimen would be appropriate.

Adult↗
PubMed2001

Developing indications for the use of sentinel lymph node biopsy and adjuvant high-dose interferon alfa-2b in melanoma.

OBJECTIVES: To convene a multidisciplinary panel of dermatologists, surgical oncologists, and medical oncologists to formally review available data on the sentinel lymph node (SLN) biopsy procedure and high-dose adjuvant interferon alfa-2b therapy for patients with melanoma and to rate the "appropriateness," "inappropriateness," or "uncertainty" of the procedure and therapy to guide clinical decision making in practice. PARTICIPANTS: The panel comprised 13 specialists (4 dermatologists, 4 oncologists, and 5 surgeons) from geographically diverse areas who practiced in community-based settings (n = 8) and academic institutions (n = 5). Participants were chosen based on recommendations from the relevant specialty organizations. EVIDENCE: A formal literature review was conducted by investigators at Protocare Sciences Inc, Santa Monica, Calif, on the risks and benefits of performing an SLN biopsy in patients with stage I or II melanoma and adjuvant interferon alfa-2b therapy in patients with stage II or III disease. The MEDLINE database was searched from 1966 through July 2000, and supplemental information was obtained from various cancer societies and cancer research groups. Panel participants were queried on additional sources of relevant information. Unpublished, presented data were included in abstract form on 1 recently closed clinical trial. CONSENSUS PROCESS: The RAND/UCLA Appropriateness Method was used to review and rate multiple clinical scenarios for the use of SLN biopsy and interferon alfa-2b therapy. The consensus method did not force agreement. CONCLUSIONS: The panel rated 104 clinical scenarios and concluded that the SLN biopsy procedure was appropriate for primary melanomas deeper than 1.0 mm and for tumors 1 mm or less when histologic ulceration was present and/or classified as Clark level 4 or higher. The SLN biopsy was deemed inappropriate for nonulcerated Clark level 2 or 3 melanomas 0.75 mm or less in depth and uncertain in tumors 0.76 to 1.0 mm deep unless they were ulcerated or Clark level 4 or higher. Interferon alfa-2b therapy was deemed appropriate for patients with regional nodal and/or in-transit metastasis and for node-negative patients with primary melanomas deeper than 4 mm. The panel considered the use of interferon alfa-2b therapy uncertain in patients with ulcerated intermediate primary tumors (2.01-4.0 mm in depth) and inappropriate for node-negative patients with nonulcerated tumors less than 4.0 mm deep. Specialty-specific ratings were conducted as well.

Chemotherapy, Adjuvant↗
PubMed2001

Randomized trial of lamivudine versus hepatitis B immunoglobulin for long-term prophylaxis of hepatitis B recurrence after liver transplantation.

BACKGROUND/AIMS: The long-term prophylaxis of hepatitis B after liver transplantation requires further optimization. In a randomized trial we investigated a regimen where the initially given hepatitis B immunoglobulin (HBIg) is replaced by long-term lamivudine treatment. METHODS: Twenty-four liver transplant recipients (all HBsAg-positive/HBV DNA-negative before transplantation), who had received HBIg for at least 6 months without HBV recurrence, were randomized to receive lamivudine (n = 12) or HBIg (n = 12) for 52 weeks. The efficacy criteria involved seronegativity for HBsAg and undetectable HBsAg/ HBcAg in the liver. RESULTS: Twenty-one of 24 patients completed the study without hepatitis B virus (HBV) recurrence (11 on HBIg, ten on lamivudine), while three patients became HBsAg-positive. Amongst those without HBV recurrence HBV DNA was detectable only by polymerase chain reaction, intermittently in serum and lymphocytes, and in liver specimens from six of eight patients receiving HBIg and five of seven receiving lamivudine. YMDD variant was found in four cases with no viral antigen expression. Eight patients continued lamivudine after the study and during an additional 6-22 months remained HBsAg-negative with normal graft function. CONCLUSIONS: Substitution of HBIg with lamivudine is effective for prevention of HBV recurrence in low-risk liver transplant recipients and offers a convenient and cost-effective alternative for long-term HBV prophylaxis.

Adult↗
PubMed2001

Randomized, controlled trial of oros methylphenidate once a day in children with attention-deficit/hyperactivity disorder.

OBJECTIVE: A new once-a-day methylphenidate (MPH) formulation, Concerta (methylphenidate HCl) extended-release tablets (OROS MPH), has been developed. This study was conducted to determine the safety and efficacy of OROS MPH in a multicenter, randomized, clinical trial. METHODS: Children with attention-deficit/hyperactivity disorder (ADHD; n = 282), all subtypes, ages 6 to 12 years, were randomized to placebo (n = 90), immediate-release methylphenidate (IR MPH) 3 times a day (tid; dosed every 4 hours; n = 97), or OROS MPH once a day (qd; n = 95) in a double-blind, 28-day trial. Outcomes in multiple domains were assessed, and data were analyzed using analysis of variance and Kaplan Meier product limit estimates for time to study cessation. The primary time point for analysis was the last available patient visit using last observation carried forward. RESULTS: Children in the OROS and IR MPH groups showed significantly greater reductions in core ADHD symptoms than did children on placebo. This was true both at the end of week 1 and at the end of treatment on the basis of mean teacher and parent IOWA Conners ratings. IR MPH tid and OROS MPH qd did not differ significantly on any direct comparisons. Forty-eight percent of the placebo group discontinued early compared with 14% and 16% in the IR MPH and OROS MPH groups, respectively. CONCLUSIONS: For the treatment of core ADHD symptoms, OROS MPH dosed qd and IR MPH dosed tid were superior to placebo and were not significantly different from each other.attention-deficit/hyperactivity disorder, methylphenidate, OROS, Concerta.

Appetite↗
PubMed2001

Practical guidelines for the management of biochemotherapy-related toxicity in melanoma.

The combination of cisplatin-based chemotherapy with interleukin 2 (IL-2) and IFN-alpha, referred to as biochemotherapy or chemoimmunotherapy, has shown promising antitumor activity in patients with metastatic melanoma. Phase II studies have reported overall response rates ranging from 40 to 60%, with durable complete remissions in approximately 10% of the patients. Toxicity, however, is often severe and can be life-threatening if the healthcare team is not familiar with toxicity management. In this report, we briefly describe the clinical results of the most effective biochemotherapy regimens and provide a detailed description and management of the most common toxic effects, with emphasis on the concurrent biochemotherapy program initially developed at M. D. Anderson Cancer Center and currently being tested in a slightly modified version in two large-scale Intergroup Phase III trials.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2000

Prognostic factors in metastatic melanoma: a pooled analysis of Eastern Cooperative Oncology Group trials.

PURPOSE: To identify factors that are prognostic for survival in patients with metastatic melanoma treated in eight Eastern Cooperative Oncology Group (ECOG) trials conducted over the past 25 years. METHODS: We identified common, significant patient characteristics collected at baseline on 1,362 eligible patients for inclusion in a pooled analysis. Proportional hazards models were used to examine simultaneously the effects of multiple covariates on survival. RESULTS: Median survival was 6.4 months (95% confidence interval, 6.1 to 6.9 months.) Factors conferring the greatest increased risk of death included number of metastatic sites (relative risk [RR] = 1.12), ECOG performance status of 1 or more (RR = 1.49), or metastatic disease in the gastrointestinal (GI) tract (RR = 1.49), liver (RR = 1.44), pleura (RR = 1.35), or lung (RR = 1.19). Prior immunotherapy (RR = 0.84) and female sex (RR = 0. 87) were associated with prolonged survival. Although only 12% of patients responded to protocol treatment, landmark analysis showed this to be a significant prognostic factor (RR = 0.57). A model based on three recent studies in which baseline values for alkaline phosphatase, lactate dehydrogenase (LDH), and platelets were available identified an increased number of sites of metastasis (RR = 1.30), abnormal LDH (RR = 1.89), abnormal alkaline phosphatase (RR = 1.76), abnormal platelets (RR = 1.63), and GI metastases (RR = 1. 66) as prognostic for poorer survival. Response to treatment, when examined by landmark analysis of studies with laboratory parameters, was associated with decreased risk of death (RR = 0.47). CONCLUSION: This study demonstrates the importance and utility of laboratory parameters as prognostic factors for survival and confirmed the deleterious effects of multiple metastatic sites. Prior immunotherapy and female sex were associated with improved prognosis. Prognostic factors identified in this analysis are consistent with the findings of prior published studies and argue for the adoption of laboratory findings in the staging systems that are used for entry and stratification of clinical trials in the future.

Adolescent↗
PubMed2000

Evolution of lamivudine-resistant hepatitis B virus and HIV-1 in co-infected individuals: an analysis of the CAESAR study. CAESAR co-ordinating committee.

OBJECTIVES: Lamivudine has potent activity against HIV-1 and hepatitis B virus (HBV). Co-infection with these two viruses is common, and this may therefore influence the choice of antiretroviral therapies. A cohort of co-infected patients treated with lamivudine were studied in order to evaluate the differential effects of lamivudine on the two viral populations within the same individual after 44-52 weeks of therapy. DESIGN AND METHODS: Retrospective virological analysis of an HIV-1/HBV co-infected lamivudine cohort derived from a randomized, placebo-controlled study of lamivudine in HIV infection, the CAESAR study. RESULTS: Five of thirteen patients with HBV viral load > 10,000 copies/ml after 44-52 weeks of lamivudine therapy had genotypic drug resistance. Four of these five had a rebound of viral replication over the period of study and in one case this was associated with an alanine transaminase serum elevation. Ten of the thirteen patients had a 44-52 week HIV viral load > 1000 copies/ml, all of whom also had HIV reverse transcriptase M184V or M184I mutations. CONCLUSIONS: Extrapolating these results to the population yields an estimated 1-year incidence of drug-resistant HBV of at least 14% in lamivudine-treated HIV-1/HBV co-infected patients. The clinical and virological benefit of HBV lamivudine monotherapy in co-infected patients should be balanced against the potential for emergence of drug resistance. Further, these data suggest that the determinants of HIV and HBV drug resistance are different and that parallel evolution, rather than co-evolution of HBV and HIV-1 in co-infected individuals occurs.

CD4 Lymphocyte Count↗
PubMed2000

Phase II trial of interleukin 2, interferon alpha, and 5-fluorouracil in metastatic renal cell cancer: a cytokine working group study.

The purpose of this study was to evaluate the potential efficacy of alternating two outpatient regimens for the treatment of metastatic renal cell cancer. These regimens consisted of 4 weeks of recombinant interleukin 2 (rIL-2) plus IFN-alpha2B followed by 4 weeks of 5-fluorouracil plus IFN-alpha2B. Fifty patients meeting eligibility criteria of previous Cytokine Working Group studies were treated on an outpatient basis. Patients received s.c. rIL-2 (Proleukin; Chiron, Emeryville, CA) during weeks 1-4 of the 8-week regimen. During weeks 1 and 4, the dosage for rIL-2 was 10 MIU/m2 twice daily on days 3-5, and the dosage for IFN-alpha2B (Intron; Schering Plough, Kenilworth, NJ) was 6 MIU/m2 on day 1. During weeks 2 and 3, the dosage for rIL-2 was 5 MIU/m2 on days 1, 3, and 5, and the dosage for IFN-alpha2B was 6 MIU/m2 on days 1, 3, 5. During weeks 5-8, 5-fluorouracil (750 mg/m2) was administered once weekly by i.v. infusion, and IFN-alpha2B (9 MIU/mZ) was administered as a s.c. injection three times weekly. Throughout the treatment, an assessment of quality of life was made and a symptom-distress scale was evaluated. There were two patients with complete responses (CRs) and seven with partial responses (PRs) for an objective response rate of 18% (95% confidence interval, 10-25). The median response duration was 8 months (range, 3-51+ months). The CRs lasted 5 months and 51+ months and the PRs ranged from 3+ to 18 months. After completing at least one course of treatment, eight patients (three with PR, one with minor response, four with stable disease) became CRs after surgery for remaining metastatic disease. Six remain alive at 43+ to 53+ months, and 5 remain disease-free since surgery. The median survival of the study group is 17.5 months, with a maximal follow-up of 53+ months. The range in survival is 1-53+ months. Toxicity was primarily constitutional. and treatment modifications were designed to maintain toxicity at grade 2/3. The most common toxicities during treatment with IL-2/IFN were fatigue, nausea/vomiting, anorexia, skin reaction, diarrhea, fever, and liver enzyme elevations. One-third had central nervous system toxicity (headache, depression, insomnia). During 5FU/IFN treatment, 49 of 50 patients experienced grade 2/3 myelosuppression during course 1. Eight patients experienced grade 4 toxicities. In conclusion, the activity of this alternating regimen is similar to that of IL-2/IFN alone, given in 4-week cycles. The addition of 5FU/IFN failed to increase the efficacy and added new toxicity (myelosuppression). This report does not confirm the results previously reported for either alternating or simultaneous administration of these three agents. Because 5FU does not appear to add to the antitumor activity of IL-2-based therapy for renal cancer, current efforts are directed toward a Phase III randomized comparison of high-dose i.v. bolus inpatient IL-2 treatment versus treatment with outpatient s.c. injection of IL-2 plus IFN.

Adult↗
PubMed1999

Pretherapy alanine transaminase level as a determinant for hepatitis B e antigen seroconversion during lamivudine therapy in patients with chronic hepatitis B. Asian Hepatitis Lamivudine Trial Group.

In the reported Asian lamivudine trial, the rate of hepatitis B e antigen (HBeAg) seroconversion, defined as HBeAg/hepatitis B virus (HBV) DNA seroclearance and development of anti-HBe, during 52 weeks of treatment was only 13% to 16%. To evaluate whether any factors influenced HBeAg seroconversion, data from 345 patients in that trial were reanalyzed to correlate HBeAg seroconversion with variables including treatment, age, gender, body build, histology, baseline HBV-DNA levels, and alanine transaminase (ALT) levels. Exploratory analysis using stepwise modeling revealed that HBeAg seroconversion correlated highly with pretherapy ALT (P <.001) followed by lamivudine therapy (P =.013), but only marginally with baseline HBV-DNA (P =.071) and cirrhosis (P =.066) for lamivudine 100 mg and placebo comparison. Among these four variables, only pretherapy ALT still had a highly significant (P <.001) correlation and lamivudine therapy had a borderline association (P =.066) for lamivudine 25 mg and placebo comparison. Categorical analysis revealed that HBeAg seroconversion occurred earlier and the cumulative rate was significantly higher in patients with pretherapy ALT values over 2 times the upper limit of normal (ULN) as compared with treated patients with lower ALT levels or untreated control patients with the same ALT levels (P <.001, respectively). The highest HBeAg seroconversion rate was observed in 100 mg lamivudine-treated patients with ALT levels greater than 5 times the ULN (64%) compared with patients with ALT 2 to 5 times the ULN (26%, P =.03); and ALT less than 2 times the ULN, (5%, P <.001). These results suggest that pretherapy ALT is the strongest determinant for HBeAg seroconversion during lamivudine therapy, and should be considered in selecting patients for treatment.

Alanine Transaminase↗