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Stöhr W, Back D, Dunn D, Sabin C, Winston A, Gilson R, Pillay D, Hill T, Ainsworth J, Pozniak A, Leen C, Bansi L, Fisher M, Orkin C, Anderson J, Johnson M, Easterbrook P, Gibbons S, Khoo S. Factors Influencing Efavirenz and Nevirapine Plasma Concentration: Effect of Ethnicity, Weight and Co-Medication. Antivir Ther 2008. [DOI: 10.1177/135965350801300507] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Background The aim of this study was to examine factors influencing plasma concentration of efavirenz and nevirapine. Methods Data from the Liverpool Therapeutic Drug Monitoring (TDM) registry were linked with the UK Collaborative HIV Cohort (CHIC) Study. For each patient, the first measurement of efavirenz (600 or 800 mg/day) or nevirapine (400 mg/day) plasma concentration was included. Linear regression was used to evaluate the association of dose, gender, age, weight, ethnicity and concomitant antiretroviral drugs or rifampicin with log-transformed drug concentration, adjusted for time since last intake. Results Data from 339 patients on efavirenz (34% black, 17% rifampicin) and 179 on nevirapine (27% black, 6% rifampicin) were included. Multivariable models revealed the following predictors for efavirenz concentration: black ethnicity (59% higher; P<0.001), weight (10% lower per additional 10 kg; P=0.002), 800 mg/day (52% higher; P=0.027), rifampicin (35% lower; P=0.039), and zidovudine (25% lower; P=0.010). Notably, without adjustment for other factors, patients on rifampicin had 48% higher efavirenz concentration, as these patients were mostly black and on 800 mg/day. For nevirapine the predictors were black ethnicity (39% higher; P=0.002), rifampicin (40% lower; P=0.002), protease inhibitor (28% higher; P=0.008) and tenofovir (22% higher; P=0.024). Conclusions We observed clear associations between ethnicity and concentrations of nevirapine and efavirenz. Our analyses confirm that concomitant rifampicin substantially decreases concentration of both efavirenz and nevirapine; however, for efavirenz this effect was more than counterbalanced by the effect of ethnicity and increased efavirenz dose. There was also an additional impact of weight, which should be considered when determining optimal dosage. Other associations from our analysis (between tenofovir or protease inhibitor and nevirapine, and zidovudine and efavirenz), require confirmation in formal pharmacokinetic studies.
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Chandra A, Dunn D, Paul DP. Consumers' perceptions and opinions of sports injuries: an exploratory empirical study. Hosp Top 2008; 86:32-7. [PMID: 18362092 DOI: 10.3200/htps.86.1.32-37] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Millions of individuals in the United States play some sports or are involved in strenuous physical activities on a regular basis. Unfortunately, many suffer injuries due to these activities. The authors devised this study to determine consumers' perceptions and opinions associated with the injuries that they or someone they know sustained. The results of this study are beneficial to health professionals involved in preventive and rehabilitative medicine as well as sports-related protective-gear marketers.
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Dunn D, Woodburn P, Duong T, Peto J, Phillips A, Gibb D, Porter K. Current CD4 cell count and the short-term risk of AIDS and death before the availability of effective antiretroviral therapy in HIV-infected children and adults. J Infect Dis 2008; 197:398-404. [PMID: 18248303 DOI: 10.1086/524686] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
BACKGROUND Currently, there are no comparable estimates of the short-term risk of disease progression in the absence of effective antiretroviral therapy for human immunodeficiency virus (HIV)-infected adults and children. METHODS A joint analysis of 2 large studies of children with vertically acquired HIV infection (the HIV Paediatric Prognostic Markers Collaborative Study) and adults with seroconversion (the CASCADE [Concerted Action on Sero-Conversion to AIDS and Death in Europe] collaboration) was conducted. Follow-up was censored at the end of 1995, before the introduction of combination antiretroviral therapy. The incidence rates of death and AIDS or death (AIDS/death) were estimated on the basis of age and current CD4 cell count. RESULTS A total of 1260 deaths (over 20,500 person-years of follow-up) and 1894 initial AIDS events (over 17,200 person-years of follow-up) were observed among 6741 patients (3244 children [i.e., patients < or =15 years of age] and 3497 adults). Young children (age, <5 years) experienced high morbidity and mortality rates. After adjustment for the CD4 cell count, the effect of age on disease progression was not significant among older children, whereas the risk increased markedly in association with increasing age among adults. Death rates were similar among older children and adults aged approximately 20 years, as were the rates of progression to AIDS/death when cases of serious recurrent bacterial infection, which has a more restrictive case definition in adults, were excluded. CONCLUSIONS Similar CD4 cell count criteria for initiation of antiretroviral therapy can be applied to adults and children > or = 5 years of age.
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Jones JE, Austin JK, Caplan R, Dunn D, Plioplys S, Salpekar JA. Psychiatric disorders in children and adolescents who have epilepsy. Pediatr Rev 2008; 29:e9-14. [PMID: 18245299 DOI: 10.1542/pir.29-2-e9] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Arenas-Pinto A, Bhaskaran K, Dunn D, Weller IVD. The Risk of Developing Peripheral Neuropathy Induced by Nucleoside Reverse Transcriptase Inhibitors Decreases over Time: Evidence from the Delta Trial. Antivir Ther 2008. [DOI: 10.1177/135965350801300203] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Background Peripheral neuropathy (PN) in HIV-infected individuals is thought be due to a toxic effect on mitochondria induced by some nucleoside reverse transcriptase inhibitors (NRTI). Methods A time-to-event analysis was performed using data from the Delta trial to study the incidence of PN in HIV-infected individuals receiving zidovudine (AZT) alone or in combination with didanosine (ddI) or zalcitabine (ddC). In an on-treatment analysis, changes in the incidence of PN by duration of treatment were directly estimated using a flexible parametric survival model. Results A total of 3,195 patients (total follow-up 4,593 person-years) were included in the analysis. AZT+ddC was associated with a higher incidence of PN (6.2 cases/100 person-years) compared with AZT monotherapy (3.0 cases/100 person-years) and AZT+ddI (2.2 cases/100 person-years). The risk of PN peaked around day 90 following randomization (at 8.9 events/100 person-years in the AZT+ddC arm). PN was also associated with age at entry (hazard ratio (HR)=2.35 for those aged 35–44 years compared with <30) and current CD4+ T-cell count (HR=2.27 for CD4+ T-cell counts <150 cell/mm3 compared with >350). Conclusion Our findings challenge the common supposition that PN arises from cumulative exposure to NRTIs. We found that patients who developed PN tended to do so shortly after exposure to antiretroviral therapy. Therefore, our results support the hypothesis of a susceptibility in a subgroup of patients. These results will be of direct interest to those working in resource-limited countries where potentially neurotoxic dideoxynucleosides are still widely used.
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Stöhr W, Back D, Dunn D, Sabin C, Winston A, Gilson R, Pillay D, Hill T, Ainsworth J, Pozniak A, Leen C, Bansi L, Fisher M, Orkin C, Anderson J, Johnson M, Easterbrook P, Gibbons S, Khoo S. Factors influencing efavirenz and nevirapine plasma concentration: effect of ethnicity, weight and co-medication. Antivir Ther 2008; 13:675-685. [PMID: 18771051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
BACKGROUND The aim of this study was to examine factors influencing plasma concentration of efavirenz and nevirapine. METHODS Data from the Liverpool Therapeutic Drug Monitoring (TDM) registry were linked with the UK Collaborative HIV Cohort (CHIC) Study. For each patient, the first measurement of efavirenz (600 or 800 mg/day) or nevirapine (400 mg/day) plasma concentration was included. Linear regression was used to evaluate the association of dose, gender, age, weight, ethnicity and concomitant antiretroviral drugs or rifampicin with log-transformed drug concentration, adjusted for time since last intake. RESULTS Data from 339 patients on efavirenz (34% black, 17% rifampicin) and 179 on nevirapine (27% black, 6% rifampicin) were included. Multivariable models revealed the following predictors for efavirenz concentration: black ethnicity (59% higher; P<0.001), weight (10% lower per additional 10 kg; P=0.002), 800 mg/day (52% higher; P=0.027), rifampicin (35% lower; P=0.039), and zidovudine (25% lower; P=0.010). Notably, without adjustment for other factors, patients on rifampicin had 48% higher efavirenz concentration, as these patients were mostly black and on 800 mg/day. For nevirapine the predictors were black ethnicity (39% higher; P=0.002), rifampicin (40% lower; P=0.002), protease inhibitor (28% higher; P=0.008) and tenofovir (22% higher; P=0.024). CONCLUSIONS We observed clear associations between ethnicity and concentrations of nevirapine and efavirenz. Our analyses confirm that concomitant rifampicin substantially decreases concentration of both efavirenz and nevirapine; however, for efavirenz this effect was more than counterbalanced by the effect of ethnicity and increased efavirenz dose. There was also an additional impact of weight, which should be considered when determining optimal dosage. Other associations from our analysis (between tenofovir or protease inhibitor and nevirapine, and zidovudine and efavirenz), require confirmation in formal pharmacokinetic studies.
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Arenas-Pinto A, Bhaskaran K, Dunn D, Weller IVD. The risk of developing peripheral neuropathy induced by nucleoside reverse transcriptase inhibitors decreases over time: evidence from the Delta trial. Antivir Ther 2008; 13:289-295. [PMID: 18505180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
BACKGROUND Peripheral neuropathy (PN) in HIV-infected individuals is thought be due to a toxic effect on mitochondria induced by some nucleoside reverse transcriptase inhibitors (NRTI). METHODS A time-to-event analysis was performed using data from the Delta trial to study the incidence of PN in HIV-infected individuals receiving zidovudine (AZT) alone or in combination with didanosine (ddl) or zalcitabine (ddC). In an on-treatment analysis, changes in the incidence of PN by duration of treatment were directly estimated using a flexible parametric survival model. RESULTS A total of 3,195 patients (total follow-up 4,593 person-years) were included in the analysis. AZT+ddC was associated with a higher incidence of PN (6.2 cases/100 person-years) compared with AZT monotherapy (3.0 cases/100 person-years) and AZT+ddl (2.2 cases/100 person-years). The risk of PN peaked around day 90 following randomization (at 8.9 events/100 person-years in the AZT+ddC arm). PN was also associated with age at entry (hazard ratio (HR)=2.35 for those aged 35-44 years compared with <30) and current CD4+ T-cell count (HR=2.27 for CD4+ T-cell counts <150 cell/mm3 compared with >350). CONCLUSION Our findings challenge the common supposition that PN arises from cumulative exposure to NRTIs. We found that patients who developed PN tended to do so shortly after exposure to antiretroviral therapy. Therefore, our results support the hypothesis of a susceptibility in a subgroup of patients. These results will be of direct interest to those working in resource-limited countries where potentially neurotoxic dideoxynucleosides are still widely used.
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Dunn D, Geretti AM, Green H, Fearnhill E, Pozniak A, Churchill D, Pillay D, Sabin C, Phillips A. Population trends in the prevalence and patterns of protease resistance related to exposure to unboosted and boosted protease inhibitors. Antivir Ther 2008; 13:771-777. [PMID: 18839778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
BACKGROUND In recent years, several new drugs from the protease inhibitor (PI) class designed to treat HIV infection have become available and the use of ritonavir-boosting has increased in popularity. These changes might be expected to affect the prevalence and patterns of protease resistance in the population of patients who experience treatment failure. METHODS The UK HIV Drug Resistance Database aims to capture the results of all genotypic resistance tests conducted nationally. Tests on antiretroviral therapy-experienced patients were identified through linkage with the UK Collaborative HIV Cohort Study, from which detailed clinical information on these patients, including a full antiretroviral therapy history, was obtained. RESULTS Analyses were on the basis of 8,553 genotypic resistance tests carried out between 1998 and 2005, during which time the overall prevalence of protease resistance halved from 35% to 16%. Substantial declines were observed regardless of whether the patient had been exposed to unboosted PIs and/or boosted PIs. The frequency of protease resistance among patients who had received boosted PIs fell sharply until 2002 with a weaker trend thereafter, falling to 12% in 2005. Individual mutations L33F, M461/L, V82A/F/T/S/L and 184V became relatively more frequent over the period of study. CONCLUSIONS The decline in protease resistance was partly due to increasing use of ritonavir-boosting. Nonetheless, the prevalence of resistance was higher than suggested by clinical trials, indicating that prolonged exposure to a boosted PI could ultimately select for major protease mutations.
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Phillips AN, Leen C, Wilson A, Anderson J, Dunn D, Schwenk A, Orkin C, Hill T, Fisher M, Walsh J, Pillay D, Bansi L, Gazzard B, Easterbrook P, Gilson R, Johnson M, Sabin CA. Risk of extensive virological failure to the three original antiretroviral drug classes over long-term follow-up from the start of therapy in patients with HIV infection: an observational cohort study. Lancet 2007; 370:1923-8. [PMID: 18068516 DOI: 10.1016/s0140-6736(07)61815-7] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
BACKGROUND The long-term durability of viral-load suppression provided by the three original antiretroviral drugs is not well characterised. We estimated the proportion of patients who had extensive triple-class failure during long-term follow-up and examined characteristics associated with an increased rate of failure. METHODS 7916 patients who started antiretroviral therapy with three or more drugs were followed up from the time that therapy started until the last viral-load measure. Extensive triple-class virological failure was defined by failure of three subclasses of nucleoside reverse transcriptase inhibitors, a non-nucleoside reverse transcriptase inhibitor, and a ritonavir-boosted protease inhibitor. FINDINGS 167 patients developed extensive triple-class failure during 27 441 person-years of follow-up. The Kaplan-Meier estimate for the cumulative risk of extensive triple-class failure was 9.2% by 10 years (95% CI 5.0-13.4). There was evidence that this rate has decreased over time (adjusted hazard ratio 0.86 [0.77-0.96] per year more recent; p=0.006). Of the 167 patients with extensive triple-class failure, 101 (60%) subsequently had at least one viral load less than 50 copies per mL. The risk of death by 5 years from the time of extensive triple-class failure was 10.6% (2.4-18.8, nine deaths). INTERPRETATION We have shown that extensive virological failure of the three main classes of drugs occurs slowly in routine clinical practice. This finding has implications for the planning of treatment programmes in developing countries, where additional drugs outside these classes are unlikely to be available for some time.
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Dunn D, Pillay D. UK HIV drug resistance database: background and recent outputs. JOURNAL OF HIV THERAPY 2007; 12:97-98. [PMID: 18578092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
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Gifford RJ, de Oliveira T, Rambaut A, Pybus OG, Dunn D, Vandamme AM, Kellam P, Pillay D. Phylogenetic surveillance of viral genetic diversity and the evolving molecular epidemiology of human immunodeficiency virus type 1. J Virol 2007; 81:13050-6. [PMID: 17898057 PMCID: PMC2169105 DOI: 10.1128/jvi.00889-07] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2007] [Accepted: 09/17/2007] [Indexed: 11/20/2022] Open
Abstract
With ongoing generation of viral genetic diversity and increasing levels of migration, the global human immunodeficiency virus type 1 (HIV-1) epidemic is becoming increasingly heterogeneous. In this study, we investigate the epidemiological characteristics of 5,675 HIV-1 pol gene sequences sampled from distinct infections in the United Kingdom. These sequences were phylogenetically analyzed in conjunction with 976 complete-genome and 3,201 pol gene reference sequences sampled globally and representing the broad range of HIV-1 genetic diversity, allowing us to estimate the probable geographic origins of the various strains present in the United Kingdom. A statistical analysis of phylogenetic clustering in this data set identified several independent transmission chains within the United Kingdom involving recently introduced strains and indicated that strains more commonly associated with infections acquired heterosexually in East Africa are spreading among men who have sex with men. Coalescent approaches were also used and indicated that the transmission chains that we identify originated in the late 1980s to early 1990s. Similar changes in the epidemiological structuring of HIV epidemics are likely to be taking in place in other industrialized nations with large immigrant populations. The framework implemented here takes advantage of the vast amount of routinely generated HIV-1 sequence data and can provide epidemiological insights not readily obtainable through standard surveillance methods.
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Abstract
PURPOSE To determine if the clinical characteristics of nonepileptic seizures (NES) are different in children younger than 13 years age as compared to adolescents. METHODS Retrospective review of medical records and video-EEGs (VEEG) of all patients with NES confirmed on VEEG monitoring was performed. RESULTS Sixty-eight (3.5%) of 1,967 patients monitored with VEEG had a clinical diagnosis of NES. Fifty-nine of 68 patients had their habitual event recorded. Mean age at the time of the VEEG diagnosis was 13 years 4 months. Twenty-two patients were less than 13 years (group A) and 37 were 13 years and older (group B). The male to female ratio was equal in group A, with female predominance seen in group B. NES commonly manifested as subtle motor activity in group A (p < 0.01) and prominent motor activity in group B (p < 0.001). Difficulties at school, family discord, and interpersonal conflicts, were frequent stressors in both groups. Sexual abuse was the least frequent. Depression was more common in group B; cognitive dysfunction (p < 0.001) and epilepsy (p < 0.01) were more common in group A. CONCLUSIONS Differences in clinical semiology and predisposing factors may help identify young children and adolescents who might be at risk for the development of NES.
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Carlson GA, Dunn D, Kelsey D, Ruff D, Ball S, Ahrbecker L, Allen AJ. A pilot study for augmenting atomoxetine with methylphenidate: safety of concomitant therapy in children with attention-deficit/hyperactivity disorder. Child Adolesc Psychiatry Ment Health 2007; 1:10. [PMID: 17897473 PMCID: PMC2098748 DOI: 10.1186/1753-2000-1-10] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2007] [Accepted: 09/27/2007] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND This study examined augmenting atomoxetine with extended-release methylphenidate in children whose attention-deficit/hyperactivity disorder (ADHD) previously failed to respond adequately to stimulant medication. METHODS Children with ADHD and prior stimulant treatment (N = 25) received atomoxetine (1.2 mg/kg/day) plus placebo. After 4 weeks, patients who were responders (n = 4) were continued on atomoxetine/placebo while remaining patients were randomly assigned to either methylphenidate (ATX/MPH) (1.1 mg/kg/day) or placebo augmentation (ATX/PB) for another 6 weeks. Patients and sites were blind to timing of active augmentation. Safety measures included vital signs, weight, and adverse events. Efficacy was assessed by ADHD rating scales. RESULTS Categorical increases in vital signs occurred for 5 patients (3 patients in ATX/MPH, 2 patients in ATX/PBO). Sixteen percent discontinued the study due to AE, but no difference between augmentation groups. Atomoxetine treatment was efficacious on outcome measures (P <or= .001), but methylphenidate did not enhance response. CONCLUSION Methylphenidate appears to be safely combined with atomoxetine, but conclusions limited by small sample. With atomoxetine treatment, 43% of patients achieved normalization on ADHD ratings.
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Phillips AN, Gazzard B, Gilson R, Easterbrook P, Johnson M, Walsh J, Leen C, Fisher M, Orkin C, Anderson J, Pillay D, Delpech V, Sabin C, Schwenk A, Dunn D, Gompels M, Hill T, Porter K, Babiker A. Rate of AIDS diseases or death in HIV-infected antiretroviral therapy-naive individuals with high CD4 cell count. AIDS 2007; 21:1717-21. [PMID: 17690569 DOI: 10.1097/qad.0b013e32827038bf] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To assess the absolute rate of AIDS and death in antiretroviral therapy (ART)-naive patients with a high CD4 cell count. Such information would be helpful in the design of a trial investigating early initiation of ART. DESIGN Analysis of data from an ongoing HIV cohort study. METHODS The rate of (severe) AIDS or death and death alone was evaluated in ART-naive patients according to the current CD4 cell count, focusing on CD4 cell counts > or = 350 cells/microl among patients in the UK CHIC Study. RESULTS In a total of 30 313 person-years of follow-up, there were 1557 AIDS or death events. The rate of AIDS or death in persons with most recent CD4 cell count 350-499, 500-649 and > 650 cells/microl was 2.49, 1.54 and 0.96 per 100 person-years, respectively. The rate ratio for those with CD4 cell count 500-649 cells/microl compared with those with CD4 cell count > or = 650 cells/microl was 1.55 [95% confidence interval (CI), 1.11-2.17; P = 0.01]. In a Poisson regression model based on person years with CD4 cell count > or = 350 cells/microl , there was a strong effect of CD4 cell count on rate of AIDS or death (rate ratio, 0.84; 95% CI, 0.76-0.93; P = 0.001), independent of viral load and age. CONCLUSIONS The trend of decreasing rate of AIDS and death with higher CD4 cell count is present throughout the CD4 cell count > or = 350 cells/microl range in ART-naive people.
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Benzie AA, Bansi LK, Sabin CA, Portsmouth S, Hill T, Johnson M, Gilson R, Easterbrook P, Gazzard B, Fisher M, Orkin C, Dunn D, Delpech V, Taylor GP, Walsh JC, Phillips AN. Increased duration of viral suppression is associated with lower viral rebound rates in patients with previous treatment failures. AIDS 2007; 21:1423-30. [PMID: 17589188 DOI: 10.1097/qad.0b013e3281532ca7] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVE We investigated whether the rate of viral rebound decreases with increasing duration of viral suppression and, if so, whether rebound rates in patients previously failing antiretroviral regimens ultimately decline to levels as low as those seen in patients who have never experienced virological failure. METHODS All patients from the UK CHIC Study (n = 21 256) who achieved a viral load (VL) of < or = 50 copies/ml while receiving HAART were followed until viral rebound (two consecutive VL > 400 copies/ml). Patients could re-enter the analysis if they experienced a subsequent VL < or = 50 copies/ml. Rebound rates were calculated according to the number of regimens previously failed and duration of viral suppression. RESULTS Of 12 648 patients on HAART 10 237 (80.9%) achieved a VL < or = 50 copies/ml. During 26 494 person-years (PY) of follow-up, 1853 (18.1%) patients experienced at least one viral rebound 'event', with 2460 events in total [rebound rate, 9.3 (range, 8.9-9.7)/100 PY). Within the first year of viral suppression, the rate of viral rebound was 8.3 (7.5-9.1)/100 PY in patients who had not previously failed treatment, increasing to 32.7 (27.6-37.8)/100 PY in patients who had failed more than four regimens. Irrespective of previous treatment failure, rebound rates in those who remained suppressed for > 4 years were similar to those in patients who had at no time experienced treatment failure. CONCLUSION After around 4 years of viral suppression rebound rates in individuals with multiple prior treatment failures approach those of individuals with no prior treatment failure.
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Wernicke JF, Holdridge KC, Jin L, Edison T, Zhang S, Bangs ME, Allen AJ, Ball S, Dunn D. Seizure risk in patients with attention-deficit-hyperactivity disorder treated with atomoxetine. Dev Med Child Neurol 2007; 49:498-502. [PMID: 17593120 DOI: 10.1111/j.1469-8749.2007.00498.x] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The comorbidity of seizures, epilepsy, and attention-deficit-hyperactivity disorder (ADHD) prompted the examination of whether atomoxetine use for ADHD is associated with an increased risk of seizures. Seizures and seizure-related symptoms were reviewed from two independent Eli Lilly and Company databases: the atomoxetine clinical trials database and the atomoxetine postmarketing spontaneous adverse event database. Review of clinical trial data indicated that the crude incidence rates of seizure adverse events were between 0.1 and 0.2%, and were not significantly different between atomoxetine, placebo, and methylphenidate. Only 2% of the postmarketing spontaneous reports of seizure events were classified as having no clear contributing or confounding factors, and the reporting rate (8 per 100 000 patients exposed) was within the expected range of population-based incidence. Although children with ADHD are increasingly recognized as being at an elevated risk for seizures, treatment of ADHD symptoms with atomoxetine does not appear to elevate this risk further. The shared vulnerability between ADHD and seizure activity should be taken into account when making treatment decisions for populations of children with epilepsy and children with ADHD.
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Cane PA, Green H, Fearnhill E, Dunn D. Identification of accessory mutations associated with high-level resistance in HIV-1 reverse transcriptase. AIDS 2007; 21:447-55. [PMID: 17301563 DOI: 10.1097/qad.0b013e3280129964] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To identify accessory mutations associated with high levels of resistance to reverse transcriptase inhibitors (RTI). DESIGN HIV pol sequences from routine resistance tests from over 3000 patients who were treatment experienced and infected with subtype B HIV-1 were analysed. Changes relative to the wild-type amino acid for codons 1-400 of reverse transcriptase were determined in two series: (i) samples showing the accumulation of thymidine analogue mutations (TAMs); and (ii) samples showing the accumulation of non-nucleoside reverse transcriptase inhibitor (NNRTI) resistance mutations. METHODS Accessory mutations were identified as occurring in those codons in which there was a statistically significant association between the distribution of amino acids and the number of TAMs/NNRTI resistance mutations. Positions already established as drug resistance positions by the International AIDS Society - USA Panel were not included in this analysis. RESULTS Twenty-four positions were identified where accessory mutations were associated with the accumulation of TAMs (20, 35, 39, 43, 60, 83, 98, 101, 122, 135, 179, 196, 203, 208, 218, 223, 228, 284, 322, 356, 359, 360, 371 and 381). Likewise changes at 25 positions (6, 20, 35, 39, 43, 53, 68, 90, 98, 101, 122, 179, 200, 203, 208, 218, 221, 223, 228, 284, 318, 320, 348, 359 and 371) were associated with NNRTI mutations. The accumulation of accessory mutations correlated with increasing numbers of TAMs and NNRTI mutations. CONCLUSION The development of high-level resistance to RTI is associated not only with the accumulation of recognized mutations but also with accessory mutations.
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Gifford R, de Oliveira T, Rambaut A, Myers RE, Gale CV, Dunn D, Shafer R, Vandamme AM, Kellam P, Pillay D. Assessment of automated genotyping protocols as tools for surveillance of HIV-1 genetic diversity. AIDS 2006; 20:1521-9. [PMID: 16847407 DOI: 10.1097/01.aids.0000237368.64488.ae] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND The routine use of drug resistance testing provides an abundant source of HIV-1 sequence data. However, it is not clear how reliable standard genotyping of these sequences is for describing HIV-1 genetic variation and for detecting novel genetic variants and epidemiological trends. OBJECTIVES To compare assignment of HIV-1 resistance test sequences to reference strains across commonly used genotyping protocols. METHODS Subtype assignments were compared across three standard genotyping protocols for 10 537 resistance test sequences, representing approximately one-fifth of all reported infections in the United Kingdom. Sequences that were inconsistently genotyped across methods, or that were unassigned by at least one method, were examined for evidence of recombination using sliding-window-based approaches. RESULTS Although agreement across methods was high for subtypes B, C and H, it was generally much lower (< 50%) for other subtypes. Disagreement between methods typically involved closely related, but epidemiologically distinct, groups or involved a significant proportion ( approximately 12%) of divergent sequences in which analysis revealed widespread evidence of recombination and a remarkable diversity of unusual recombinant forms. CONCLUSIONS With frequent long-distance transfer of viral strains and widespread recombination between them, genetic and epidemiological relationships within HIV-1 are becoming increasingly complex. Current methods of subtype assignment vary in their ability to identify novel genetic variants and to distinguish epidemiologically distinct strains. Capturing meaningful epidemiological information from resistance test data will require a critical understanding of the methodologies used in order to appreciate the possible sources of error and misclassification.
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Prahalad S, Bohnsack JF, Jorde LB, Whiting A, Clifford B, Dunn D, Weiss R, Moroldo M, Thompson SD, Glass DN, Bamshad MJ. Association of two functional polymorphisms in the CCR5 gene with juvenile rheumatoid arthritis. Genes Immun 2006; 7:468-75. [PMID: 16775617 PMCID: PMC2927816 DOI: 10.1038/sj.gene.6364317] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Juvenile rheumatoid arthritis (JRA) is mediated by Th1-immune responses. In children with JRA, synovial T cells express high levels of the Th1-chemokine receptor CC chemokine receptor 5 (CCR5), which has been implicated in susceptibility to rheumatoid arthritis. To test the hypothesis that genetic variation in CCR5 is associated with susceptibility to JRA, we analyzed patterns of variation in the 5'cis-regulatory region of CCR5 in 124 multiplex families from a JRA-affected sibpair registry. After sequencing the upstream region of CCR5, variants were tested for association with JRA by transmission disequilibrium testing. A single nucleotide polymorphism, C-1835T, was significantly undertransmitted to children with early-onset JRA (P<0.01). C-1835T was genotyped in 424 additional simplex and multiplex families. CCR5-1835T allele was undertransmitted in the cohort of all probands with JRA (P<0.02), as well as in those with early-onset (P<0.01) or pauciarticular JRA (P<0.05). Another variant, a 32-bp deletion in the open reading frame of CCR5 (CCR5-Delta32) was also tested in approximately 700 simplex and multiplex families. CCR5-Delta32 was also significantly undertransmitted to probands with early-onset JRA (P<0.05). Both variants are in regions under natural selection, and result in functional consequences. Our results suggest these CCR5 variants are protective against early-onset JRA.
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Binnewies TT, Motro Y, Hallin PF, Lund O, Dunn D, La T, Hampson DJ, Bellgard M, Wassenaar TM, Ussery DW. Ten years of bacterial genome sequencing: comparative-genomics-based discoveries. Funct Integr Genomics 2006; 6:165-85. [PMID: 16773396 DOI: 10.1007/s10142-006-0027-2] [Citation(s) in RCA: 102] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2006] [Revised: 02/24/2006] [Accepted: 03/07/2006] [Indexed: 10/24/2022]
Abstract
It has been more than 10 years since the first bacterial genome sequence was published. Hundreds of bacterial genome sequences are now available for comparative genomics, and searching a given protein against more than a thousand genomes will soon be possible. The subject of this review will address a relatively straightforward question: "What have we learned from this vast amount of new genomic data?" Perhaps one of the most important lessons has been that genetic diversity, at the level of large-scale variation amongst even genomes of the same species, is far greater than was thought. The classical textbook view of evolution relying on the relatively slow accumulation of mutational events at the level of individual bases scattered throughout the genome has changed. One of the most obvious conclusions from examining the sequences from several hundred bacterial genomes is the enormous amount of diversity--even in different genomes from the same bacterial species. This diversity is generated by a variety of mechanisms, including mobile genetic elements and bacteriophages. An examination of the 20 Escherichia coli genomes sequenced so far dramatically illustrates this, with the genome size ranging from 4.6 to 5.5 Mbp; much of the variation appears to be of phage origin. This review also addresses mobile genetic elements, including pathogenicity islands and the structure of transposable elements. There are at least 20 different methods available to compare bacterial genomes. Metagenomics offers the chance to study genomic sequences found in ecosystems, including genomes of species that are difficult to culture. It has become clear that a genome sequence represents more than just a collection of gene sequences for an organism and that information concerning the environment and growth conditions for the organism are important for interpretation of the genomic data. The newly proposed Minimal Information about a Genome Sequence standard has been developed to obtain this information.
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Doerholt K, Duong T, Tookey P, Butler K, Lyall H, Sharland M, Novelli V, Riordan A, Dunn D, Walker AS, Gibb DM. Outcomes for human immunodeficiency virus-1-infected infants in the United kingdom and Republic of Ireland in the era of effective antiretroviral therapy. Pediatr Infect Dis J 2006; 25:420-6. [PMID: 16645506 DOI: 10.1097/01.inf.0000214994.44346.d3] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND There are few data about disease progression and response to antiretroviral therapy (ART) in vertically HIV-infected infants in the era of effective therapy. DESIGN Cohort study. METHODS We examined progression to acquired immunodeficiency syndrome (AIDS) and death over calendar time for infants reported to the National Study of HIV in Pregnancy and Childhood in the United Kingdom/Ireland. The use of ART and CD4 and HIV-1 RNA responses were assessed in a subset in the Collaborative HIV Pediatric Study. RESULTS Among 481 infants, mortality was lower in those born after 1997 (HR 0.30; P < 0.001), with no significant change in progression to AIDS. Of 174 infants born since 1997 in the Collaborative HIV Pediatric Study, 41 (24%) were followed from birth, 77 (44%) presented pre-AIDS and 56 (32%) presented with AIDS. Of 125 (72%) children on 3- or 4-drug ART by the age of 2 years, 59% had HIV-1 RNA <400 at 12 months; median CD4 percentage increased from 24% to 35%. Among 41 infants followed from birth, 12 progressed to AIDS (5 while ART naive) and 3 died; 1 of 10 infants initiating ART before 3 months of age progressed clinically. CONCLUSION Mortality in HIV-infected infants is significantly lower in the era of effective ART, but symptomatic disease rates remain high. Infrequent clinic attendance and poor compliance with cotrimoxazole prophylaxis and/or ART in infants born to diagnosed HIV-infected women and late presentation of infants identified after birth appear to be major contributors. Poor virologic response to ART during infancy is of concern because of increased likelihood of early development of resistance.
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Knox A, Dunn D, Paller M, Nelson E, Specht W, Seaman J. Assessment of Contaminant Retention in Constructed Wetland Sediments. Eng Life Sci 2006. [DOI: 10.1002/elsc.200620116] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
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Cane P, Chrystie I, Dunn D, Evans B, Geretti AM, Green H, Phillips A, Pillay D, Porter K, Pozniak A, Sabin C, Smit E, Weber J, Zuckerman M. Time trends in primary resistance to HIV drugs in the United Kingdom: multicentre observational study. BMJ 2005; 331:1368. [PMID: 16299012 PMCID: PMC1309643 DOI: 10.1136/bmj.38665.534595.55] [Citation(s) in RCA: 149] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVE To examine whether the level of primary resistance to HIV drugs is increasing in the United Kingdom. DESIGN Multicentre observational study. SETTING All virology laboratories in the United Kingdom carrying out tests for HIV resistance as part of routine clinical care. PARTICIPANTS 2357 people infected with HIV who were tested for resistance before receiving antiretroviral therapy. MAIN OUTCOME MEASURE Prevalence of drug resistance on basis of the Stanford genotypic interpretation system. RESULTS Over the study period (February 1996 to May 2003), 335 (14.2%, 95% confidence interval 12.8% to 15.7%) samples had mutations that conferred resistance to one or more antiretroviral drugs (9.3% high level resistance, 5.9% medium level resistance). The prevalence of primary resistance has increased markedly over time, although patterns are specific to drug class; the largest increase was for non-nucleoside reverse transcriptase inhibitors. In 2002-3, the prevalence of resistance to any antiretroviral drug to nucleoside or nucleotide reverse transcriptase inhibitors, to non-nucleoside reverse transcriptase inhibitors, or to protease inhibitors was 19.2% (15.7% to 23.2%), 12.4% (9.5% to 15.9%), 8.1% (5.8% to 11.1%), and 6.6% (4.4% to 9.3%), respectively. The risk of primary resistance was only weakly related to most demographic and clinical factors, including ethnicity and viral subtype. CONCLUSIONS The United Kingdom has one of the highest reported rates of primary resistance to HIV drugs worldwide. Prevalence seems still to be increasing and is high in all demographic subgroups.
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Collins G, Johnson E, Kroshus T, Ganz R, Batts K, Seng J, Nwaneri O, Dunn D. Experience with minimally invasive esophagectomy. Surg Endosc 2005; 20:298-301. [PMID: 16362469 DOI: 10.1007/s00464-005-0093-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2005] [Accepted: 07/29/2005] [Indexed: 01/24/2023]
Abstract
BACKGROUND Minimally invasive esophagectomy (MIE) is an evolving surgical alternative to traditional open esophagectomy. Despite considerable technical challenges, it was hypothesized that MIE could be performed effectively by surgeons experienced in open esophageal resection and advanced laparoscopic surgery. The authors report their experience with 25 patients who underwent MIE for esophageal disease. METHODS A multidisciplinary esophageal cancer team evaluated all the patients enrolled in this institutional review board-approved retrospective review study. Over an 18-month period, 25 consecutive patients (22 men and 3 women; mean age, 62 years; range, 48-77 years) with resectable esophageal cancer underwent MIE. Six patients were treated with neoadjuvant chemoradiotherapy. The preoperative diagnoses were adenocarcinoma (64%, n = 16), high-grade dysplasia (20%, n = 5), and squamous cell cancer (16%, n = 4). The outcomes evaluated included operative course, hospital and intensive care unit lengths of stay, pathologic stage, morbidity, and mortality. RESULTS Two patients required conversion to open esophagectomy. Operative mortality was 4% (n = 1). The mean operative time was 350 min (range, 300-480), and the average blood loss was 200 ml. The patients remained ventilated for a median of 12 h, and the median intensive care unit utilization was 1 day. The median hospital length of stay was 9 days (range, 6-33 days). Major complications occurred in 32% of the patients. The anastomotic leak rate was 12%. Minor pulmonary complications occurred in 32% and atrial fibrillation in 16% of the patients. An anastomotic stricture developed in 24% of all the patients. One patient showed a positive proximal margin in the final pathology results. CONCLUSIONS Minimally invasive esophagectomy is a technically challenging procedure that can be performed safely at the Virginia Piper Cancer Institute. Optimal results require appropriate patient selection and a multidisciplinary team experienced in the management of esophageal cancer.
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Li TQ, Mathews VP, Wang Y, Dunn D, Kronenberger W. Adolescents with Disruptive Behavior Disorder Investigated Using an Optimized MR Diffusion Tensor Imaging Protocol. Ann N Y Acad Sci 2005; 1064:184-92. [PMID: 16394156 DOI: 10.1196/annals.1340.034] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Adolescents with disruptive behavior disorder (DBD) and controls were investigated using an optimized MR diffusion tensor imaging (DTI) protocol in order to assess any possible structural abnormalities associated with DBD. Thirty-six patients and 40 normal subjects were examined. The extracted diffusion fractional anisotropy (FA) results demonstrate that for the DBD patients there is significantly reduced FA in both the frontal and left temporal regions. The largest brain area with significantly reduced FA is located within the arcuate fasciculus, which has projections extending from the temporal lobe to the frontal lobe along the lateral ventricle, lateral to the tapetum. The reduced FA reflects directly a lower extent of myelination and less coherent fiber track structures in the fasciculus, which in turn may indicate communication weakness among the associated cortical areas. The detected white matter microstructural abnormality, therefore, may be related to the developmental deficits observed in the patient group.
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