The Experts below are selected from a list of 231 Experts worldwide ranked by ideXlab platform
Lawrence Corey - One of the best experts on this subject based on the ideXlab platform.
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changes in Plasma Human immunodeficiency virus type 1 rna associated with herpes simplex virus reactivation and suppression
The Journal of Infectious Diseases, 2002Co-Authors: Timothy W Schacker, Judith Zeh, Mary Shaughnessy, Lawrence CoreyAbstract:In early trials of antiretroviral therapy, acyclovir was associated with increased survival by an unknown mechanism. The hypothesis that subclinical herpes simplex virus (HSV) reactivation was associated, in vivo, with increased Plasma Human immunodeficiency virus (HIV) RNA and suppression with a reduced Plasma HIV RNA load was investigated. HSV cultures were performed daily on HSV-2-positive/HIV-positive patients, and Plasma HIV-1 RNA loads were measured at regular intervals. A subset of patients prior to, during, and after HSV suppression with high-dose acyclovir was measured to determine whether HSV suppression was associated with a decrease in HIV replication. Most (25/27 HSV-2-positive/HIV-positive persons) reactivated HSV. Total HSV shedding rate was strongly correlated with Plasma HIV-1 RNA load (R=0.54; P=.004), and the Plasma HIV-1 RNA level at a given CD4 cell count was 48% lower when treated with acyclovir. These data indicate that frequent mucosal HSV reactivation influences HIV replication in vivo and daily HSV suppression may be important in the management of HSV-positive/HIV-positive persons.
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Herpes Simplex Virus Shedding and Plasma Human Immunodeficiency Virus RNA Levels in Coinfected Women
Clinical infectious diseases : an official publication of the Infectious Diseases Society of America, 2001Co-Authors: Michael Augenbraun, Lawrence Corey, Patricia Reichelderfer, David J. Wright, David M. Burns, David M. Koelle, Esther Robison, Mardge H. CohenAbstract:Asymptomatic herpes simplex virus (HSV) shedding was described in a cohort of Human immunodeficiency virus (HIV)-infected women, and the association of HSV shedding with changes in Plasma HIV RNA load was investigated. Genital, rectal, and oral swabs were obtained daily during a 4-week period for polymerase chain reaction and culture, and concomitant Plasma specimens were drawn 3 times weekly for determination of HIV RNA load. During the study, 70% and 79% of subjects shed HSV from the oral cavity and genital area, respectively. Shedding of HSV occurred for a mean of 3.2 days for oral shedding and 5.4 days for genital shedding. Mean Plasma HIV RNA loads during periods of HSV shedding and nonshedding and for periods 3 days after the cessation of shedding were compared; no significant differences were found (P=.74). In women who shed HSV, as evaluated by detection of virus, Plasma HIV RNA load did not fluctuate with HSV shedding.
Courtney V. Fletcher - One of the best experts on this subject based on the ideXlab platform.
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CD4 response is correlated with peak Plasma concentrations of indinavir in adults with undetectable Human immunodeficiency virus ribonucleic acid.
Clinical pharmacology and therapeutics, 2002Co-Authors: Peter L. Anderson, Richard C. Brundage, Thomas N. Kakuda, Courtney V. FletcherAbstract:We retrospectively evaluated correlates of increases in CD4 cell count in antiretroviral agent-naive subjects with fewer than 50 copies per milliliter of Plasma Human immunodeficiency virus ribonucleic acid who were participating in a study of indinavir, lamivudine, and zidovudine therapy. Pharmacologic data from intensive pharmacokinetic studies and baseline patient characteristics were evaluated as predictors of the increase in CD4 count from baseline to weeks 24, 56, and 80. Relations were investigated with regression analysis. Of all covariates, maximum Plasma concentration (Cmax) of indinavir was significantly and uniquely associated with increases in CD4 count from baseline to all end points (P = .002 at week 80; n = 20). At week 80, subjects with a Cmax greater than the overall group median value of 7 μg/ml had an increase in CD4 count of 358 cells/μl versus 197 cells/μl for those with a Cmax less than 7 μg/ml (P = .006). These data suggest distinct pharmacodynamic relations exist for immune reconstitution and suppression of Plasma Human immunodeficiency virus ribonucleic acid. We hypothesize this new finding may be associated with expression of P-glycoprotein. Clinical Pharmacology & Therapeutics (2002) 71, 280–285; doi: 10.1067/mcp.2002.121910
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Patterns of Plasma Human Immunodeficiency Virus Type 1 RNA Response to Highly Active Antiretroviral Therapy in Infected Children
The Journal of infectious diseases, 2000Co-Authors: Stephen A. Spector, Karen Hsia, Florence H. Yong, Sheila Cabrai, Terrence Fenton, Courtney V. Fletcher, James O Mcnamara, Lynne M. Mofenson, Stuart E. StarrAbstract:This study examined the rate of decline in Plasma Human immunodeficiency virus type 1 (HIV-1) RNA levels to 70 cells/microL by 20 weeks on therapy were more likely to achieve durable virological and immunological benefit. These data provide time frames for virus suppression after the initiation of HAART that should be useful in evaluating the potential efficacy and durability of response of newly instituted combination antiretroviral therapy in HIV-1-infected children.
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a pilot study of combination therapy with indinavir stavudine d4t and didanosine ddi in children infected with the Human immunodeficiency virus
The Journal of Pediatrics, 1998Co-Authors: Mark W. Kline, Courtney V. Fletcher, Alice T. Harris, Kim D. Evans, Richard C. Brundage, Rory P. Remmel, Nancy R. Calles, Suzanne Kirkpatrick, Cara SimonAbstract:Abstract Twelve children infected with the Human immunodeficiency virus were treated orally with indinavir, stavudine, plus didanosine for 12 to 48 weeks. Therapy was limited in some cases by nonadherence, intolerance, toxicity, and virologic failure. Marked increases in CD4+ lymphocyte counts and decreases in Plasma Human immunodeficiency virus RNA concentrations suggest that the regimen has potent antiviral activity. (J Pediatr 1998;132:543-6)
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A pilot study of combination therapy with indinavir, stavudine (d4T), and didanosine (ddI) in children infected with the Human immunodeficiency virus
The Journal of Pediatrics, 1998Co-Authors: Mark W. Kline, Courtney V. Fletcher, Alice T. Harris, Kim D. Evans, Richard C. Brundage, Rory P. Remmel, Nancy R. Calles, Suzanne B. Kirkpatrick, Cara SimonAbstract:Twelve children infected with the Human immunodeficiency virus were treated orally with indinavir, stavudine, plus didanosine for 12 to 48 weeks. Therapy was limited in some cases by nonadherence, intolerance, toxicity, and virologic failure. Marked increases in CD4+ lymphocyte counts and decreases in Plasma Human immunodeficiency virus RNA concentrations suggest that the regimen has potent antiviral activity.
Elaine Gray - One of the best experts on this subject based on the ideXlab platform.
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Establishment of the World Health Organization First International Standard for Factor XII, Plasma, Human.
Frontiers in medicine, 2018Co-Authors: Helen V. Wilmot, Peter Rigsby, Jason Hockley, Elaine GrayAbstract:Until recently, the role of factor XII (FXII) in hemostasis was not considered to be important since patients with FXII deficiency do not present with bleeding. The activation of FXII by agents including mast cells and platelet polyphosphates suggests that it may have a role in thrombogenesis. The inhibition of FXII therefore presents an option for antithrombotic therapy, and antibodies and inhibitors are already in development. Assays for FXII will be required to support these technologies, and an international standard (IS) for FXII would be useful for the development of these methods and for the clinical monitoring of patients. The purpose of this study was to develop an IS for FXII, with values for functional activity (FXII:C) and antigen (FXII:Ag). Double-spun normal Plasma was pooled, filled into siliconized glass ampoules, and freeze-dried to prepare the candidate material. Data from 20 laboratories using the one-stage clotting assay were used to assign the functional activity value in units (u). The antigen value was calculated using data from eight laboratories that carried out antigen assays. Each laboratory was requested to collect two local normal Plasma pools. Units of activity and antigen were calculated relative to these pools, as is usual for new coagulation factor analytes. The amount of activity or antigen in 1 ml of normal Plasma from each pool was taken to be 1 unit. A total of 566 donors were used across the pools for the FXII:C study and 216 donors for the FXII:Ag study. The overall geometric mean per ampoule for FXII:C was 0.86 u and for FXII:Ag was 0.80 u. The inter-laboratory variation was 10 and 11%, respectively (expressed as the geometric coefficient of variation). Based on these data, the candidate was deemed suitable for use as an IS for FXII. In 2017, the candidate was established by the World Health Organization (WHO) Expert Committee on Biological Standardization as the WHO first IS for blood coagulation FXII, Plasma (National Institute for Biological Standards and Control code 15/180). The values assigned were 0.86 international units (IU) of functional activity (FXII:C) per ampoule and 0.80 IU/ampoule of antigen (FXII:Ag).
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Establishment of the World Health Organization First International Standard for Factor XII, Plasma, Human.
Frontiers in medicine, 2017Co-Authors: Helen V. Wilmot, Peter Rigsby, Jason Hockley, Elaine GrayAbstract:The 1st International Standard (IS) for Blood Coagulation Factor XI, Plasma, has been successfully used for potency labelling of factor XI (FXI) therapeutics and for diagnosis of FXI deficiency in patients. With stocks of the 1st IS near depletion, a replacement is required. In addition to the functional activity value, assignment of an antigen value to the 2nd IS would allow harmonization of antigen assay methods and differentiation of patients who have low functional activity but normal antigen FXI levels from patients who have both low functional and antigen FXI levels. The aims of this study were therefore to assign FXI functional activity to the 2nd IS for Factor XI, Plasma, and to additionally assign a new analyte, FXI antigen, to the same International Standard. The candidate material was prepared from double-spun, virology negative, normal Plasma which was pooled and filled into siliconized glass ampoules and subsequently freeze-dried. Assignment of the functional activity (FXI:C) value in International Units (IU) was performed by one-stage clotting assay by 29 laboratories, relative to the 1st IS. The overall geometric mean was 0.71 IU/ampoule with extremely low inter-laboratory variability (expressed as geometric coefficient of variation) of 1.8%. The antigen value assignment was performed by 11 laboratories and was calculated relative to normal Plasma pools, as is customary with new coagulation factor analytes. The amount of antigen present in 1 ml of normal Plasma was taken to be 1 unit. The overall geometric mean for the antigen assays was 0.78 IU/ampoule with an inter-laboratory variation of 10%. The candidate (15/180) was established by the World Health Organization (WHO) Expert Committee on Biological Standardization (ECBS) in 2016 as the WHO 2nd IS for Blood Coagulation Factor XI, Plasma, with a functional activity value (FXI:C) of 0.71 IU/ampoule and an antigen value (FXI:Ag) of 0.78 IU/ampoule.
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ASSIGNMENT OF POTENCY TO THE WHO 1 ST INTERNATIONAL STANDARD FOR BLOOD COAGULATION FACTOR XI IN Plasma, Human (04/102) AND CALIBRATION OF BLOOD COAGULATION FACTOR XI IN SSC SECONDARY Plasma STANDARD LOT #3
2017Co-Authors: Only, Elaine Gray, Stephen Thomas, Peter RigsbyAbstract:INTERNATIONAL STANDARD FOR BLOOD COAGULATION FACTOR XI IN Plasma, Human (04/102) AND CALIBRATION OF BLOOD COAGULATION FACTOR XI IN SSC SECONDARY Plasma STANDARD LOT #3 Elaine Gray, Stephen Thomas and Peter Rigsby* Division of Haematology and *Biostatistics Section National Institute for Biological Standards and Control Potters Bar, Hertfordshire, UK. SUMMARY
John W. Mellors - One of the best experts on this subject based on the ideXlab platform.
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Patterns of Plasma Human immunodeficiency virus type 1 RNA response to antiretroviral therapy
The Journal of infectious diseases, 2001Co-Authors: W. Huang, V De Gruttola, Margaret A. Fischl, Scott M. Hammer, Douglas D. Richman, Diane V. Havlir, Roy M. Gulick, Kathleen Squires, John W. MellorsAbstract:Early identification of treatment failure among Human immunodeficiency virus (HIV) type 1--infected patients receiving antiretroviral therapy could enable clinicians to modify inadequate regimens and to improve treatment response. Clinical definitions of treatment failure, however, may not be ideally suited for this purpose. This study empirically characterizes the patterns of HIV-1 RNA response to antiretroviral therapy in patients in 4 AIDS clinical trials. The approach assumed 2 patterns of HIV-1 response: "on track," for eventual suppression to HIV-1 RNA levels below the limit of quantification, and "off track," for deviation from this response. The results of this on- or off-track classification generally agreed with the protocol-defined outcomes of virologic success and failure, thus validating these commonly used definitions. Overall, only a minority of patients went off track because of suboptimal HIV-1 RNA response by the first follow-up visit. Most patients who went off track did so at later time points and had sharp unexpected rebounds without prior indication of a suboptimal response.
Robert S. Hogg - One of the best experts on this subject based on the ideXlab platform.
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High-intensity cannabis use associated with lower Plasma Human immunodeficiency virus-1 RNA viral load among recently infected people who use injection drugs.
Drug and alcohol review, 2014Co-Authors: M-j Milloy, Brandon D. L. Marshall, Thomas Kerr, Lindsey Richardson, Robert S. Hogg, Silvia Guillemi, Julio S. G. Montaner, Evan WoodAbstract:Introduction and Aims Cannabis use is common among people who are living with Human immunodeficiency virus (HIV)/acquired immune deficiency syndrome (AIDS). While there is growing pre-clinical evidence of the immunomodulatory and anti-viral effects of cannabinoids, their possible effects on HIV disease parameters in Humans are largely unknown. Thus, we sought to investigate the possible effects of cannabis use on Plasma HIV-1 RNA viral loads (pVLs) among recently seroconverted illicit drug users. Design and Methods We used data from two linked longitudinal observational cohorts of people who use injection drugs. Using multivariable linear mixed-effects modelling, we analysed the relationship between pVL and high-intensity cannabis use among participants who seroconverted following recruitment. Results Between May 1996 and March 2012, 88 individuals seroconverted after recruitment and were included in these analyses. Median pVL in the first 365 days among all seroconverters was 4.66 log10 c mL−1. In a multivariable model, at least daily cannabis use was associated with 0.51 log10 c mL−1 lower pVL (β = −0.51, standard error = 0.170, P value = 0.003). Discussion and Conclusions Consistent with the findings from recent in vitro and in vivo studies, including one conducted among lentiviral-infected primates, we observed a strong association between cannabis use and lower pVL following seroconversion among illicit drug-using participants. Our findings support the further investigation of the immunomodulatory or antiviral effects of cannabinoids among individuals living with HIV/AIDS. [Milloy M-J, Marshall B, Kerr T, Richardson L, Hogg R, Guillemi S, Montaner JSG, Wood E. High-intensity cannabis use associated with lower Plasma Human immunodeficiency virus-1 RNA viral load among recently infected people who use injection drugs. Drug Alcohol Rev 2015;34:135–40]
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Comparison of Costs of Strategies for Measuring Levels of Human Immunodeficiency Virus Type 1 RNA in Plasma by Using Amplicor and Ultra Direct Assays
Journal of clinical microbiology, 1998Co-Authors: Janet Raboud, Robert S. Hogg, Elena Seminari, Sandra Rae, P. R. Harrigan, B. Conway, Christopher H. Sherlock, Martin T. Schechter, M. V. O'shaughnessy, J. S. G. MontanerAbstract:The costs of four algorithms for monitoring Plasma Human immunodeficiency virus type 1 RNA were compared. For patients with strong virologic responses, the use of Ultra Direct exclusively was the cheapest strategy. For patients with weak virologic responses, small savings could be obtained by using Amplicor and retesting only samples with values below 500 copies/ml with Ultra Direct.