The Experts below are selected from a list of 11424 Experts worldwide ranked by ideXlab platform
Ravinder Jit Singh - One of the best experts on this subject based on the ideXlab platform.
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six month stability of bevacizumab avastin binding to vascular endothelial growth factor after withdrawal into a syringe and refrigeration or freezing
Retina-the Journal of Retinal and Vitreous Diseases, 2006Co-Authors: Sophie J Bakri, William T Weiss, Melissa R Snyder, Colin A. Mccannel, Jose S. Pulido, Ravinder Jit SinghAbstract:Purpose: To determine the change in anti–vascular endothelial growth factor (VEGF) activity of bevacizumab (Avastin, Genentech, Inc., San Francisco, CA) after refrigeration or freezing. Methods: Samples of bevacizumab were drawn up from new vials into plastic tuberculin Syringes and refrigerated at 4°C for 1 week, 3 weeks, 1 month, 3 months, and 6 months. The vials and Syringes were stored at 4°C, and the Syringes were capped with a needle. One syringe was frozen at 10°C. The bevacizumab concentration was measured, via its binding to VEGF-165. Results: The percentage of degradation of bevacizumab in the previously pierced vials stored at 4°C compared with that in the unpierced vial was 9.6% at 3 months and 12.7% at 6 months. The bevacizumab drawn into the syringe and stored at 4°C was degraded by 1.6% at 1 week, 0% at 3 weeks, 8.8% at 3 months, and 15.9% at 6 months. The bevacizumab frozen in a syringe at 10°C was degraded by 12.0% at 6 months. Conclusion: The anti-VEGF activity of bevacizumab may degrade minimally over time, with storage. RETINA 26:519–522, 2006
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six month stability of bevacizumab avastin binding to vascular endothelial growth factor after withdrawal into a syringe and refrigeration or freezing
Retina-the Journal of Retinal and Vitreous Diseases, 2006Co-Authors: Sophie J Bakri, William T Weiss, Melissa R Snyder, Colin A. Mccannel, Jose S. Pulido, Ravinder Jit SinghAbstract:Purpose To determine the change in anti-vascular endothelial growth factor (VEGF) activity of bevacizumab (Avastin, Genentech, Inc., San Francisco, CA) after refrigeration or freezing. Methods Samples of bevacizumab were drawn up from new vials into plastic tuberculin Syringes and refrigerated at 4 degrees C for 1 week, 3 weeks, 1 month, 3 months, and 6 months. The vials and Syringes were stored at 4 degrees C, and the Syringes were capped with a needle. One syringe was frozen at -10 degrees C. The bevacizumab concentration was measured, via its binding to VEGF-165. Results The percentage of degradation of bevacizumab in the previously pierced vials stored at 4 degrees C compared with that in the unpierced vial was 9.6% at 3 months and 12.7% at 6 months. The bevacizumab drawn into the syringe and stored at 4 degrees C was degraded by 1.6% at 1 week, 0% at 3 weeks, 8.8% at 3 months, and 15.9% at 6 months. The bevacizumab frozen in a syringe at -10 degrees C was degraded by 12.0% at 6 months. Conclusion The anti-VEGF activity of bevacizumab may degrade minimally over time, with storage.
Alex H Kral - One of the best experts on this subject based on the ideXlab platform.
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Higher syringe coverage is associated with lower odds of HIV risk and does not increase unsafe syringe disposal among syringe exchange program clients
Drug and Alcohol Dependence, 2007Co-Authors: Ricky N. Bluthenthal, Neil M. Flynn, Rachel Anderson, Alex H KralAbstract:Abstract Objective To determine if adequate syringe coverage – “one shot for one syringe” – among syringe exchange program (SEP) clients is associated with injection-related HIV risk behaviors and syringe disposal. Design HIV risk assessments with 1577 injection drug users (IDUs) recruited from 24 SEPs in California between 2001 and 2003. Individual syringe coverage was calculated as a proportion of Syringes retained from SEP visits to total number of injections in the last 30 days. Results Participants were divided into four groups based on syringe coverage: Conclusions Individual syringe coverage is strongly associated with safer injection behaviors without impacting syringe disposal among SEP clients. Syringe coverage is a useful measure for determining if IDUs are obtaining sufficient Syringes to lower HIV risk.
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examination of the association between syringe exchange program sep dispensation policy and sep client level syringe coverage among injection drug users
Addiction, 2007Co-Authors: Neil M. Flynn, Rachel Anderson, Ricky N. Bluthenthal, Alex H Kral, Greg Ridgeway, Terry L SchellAbstract:Aim To determine whether syringe exchange programs' (SEPs) dispensation policy is associated with syringe cover- age among SEP clients. Design Cross-sectional samples of SEPs and their clients. Setting SEPs in California, USA. Participants Twenty-four SEPs and their injection drug using (IDU) clients (n = 1576). Measurements Clients were classified as having adequate syringe coverage if they received at least as many Syringes from the SEP as their self- reported injections in the last 30 days. SEPs were classified based on their syringe dispensation policy. Dispensation schemes ranging from least restrictive to most are: unlimited needs-based distribution; unlimited one-for-one exchange plus a few additional Syringes; per visit limited one-for-one plus a few additional Syringes; unlimited one-for-one exchange; and per visit limited one-for-one exchange. Findings Adequate syringe coverage among SEP clients by dispensation policy is as follows: unlimited needs-based distribution = 61%; unlimited one-for-one plus = 50%; limited one-for-one plus = 41%; unlimited one-for-one = 42%; and limited one-for-one = 26%. In multivariate analysis, adequate syringe coverage was significantly higher for all dispensation policies compared to per visit limited one-for- one exchange. Using propensity scoring methods, we compared syringe coverage by dispensation policies while con- trolling for client-level differences. Providing additional Syringes above one-for-one exchange (50% versus 38%, P = 0.009) and unlimited exchange (42% versus 27%, P = 0.05) generally resulted in more clients having adequate syringe coverage compared to one-for-one exchange and per visit limits. Conclusion Providing less restrictive syringe dispensation is associated with increased prevalence of adequate syringe coverage among clients. SEPs should adopt syringe dispensation policies that provide IDUs sufficient Syringes to attain adequate syringe coverage.
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the effect of syringe exchange use on high risk injection drug users a cohort study
AIDS, 2000Co-Authors: Ricky N. Bluthenthal, Alex H Kral, Lauren Gee, Elizabeth A Erringer, Brian R EdlinAbstract:OBJECTIVE To determine whether syringe exchange program use is associated with cessation of syringe sharing among high-risk injection drug users. DESIGN AND METHODS Between 1992 and 1996, street-recruited injection drug users were interviewed and received HIV testing and counseling semi-annually, as part of a dynamic cohort study. We examined a cohort of 340 high-risk injection drug users for whom two observations, 6-months apart, were available and who reported syringe sharing at the first interview. Multivariate logistic regression analysis was performed to determine the relationship between syringe exchange program use and cessation of syringe sharing, while controlling for confounding factors. RESULTS At follow-up interview, 60% (204 of 340) reported quitting syringe sharing. High-risk injection drug users who began using the syringe exchange program were more likely to quit sharing Syringes [adjusted odds ratio (AOR), 2.68; 95% confidence interval (CI), 1.35-5.33], as were those who continued using the syringe exchange program (AOR,1.98; 95% CI, 1.05-3.75) in comparison with non-syringe exchange program users, while controlling for confounding factors. CONCLUSIONS The initiation and continuation of syringe exchange program use among high-risk injection drug users is independently associated with cessation of syringe sharing. Syringe exchange program use can be an important component in reducing the spread of blood-borne infectious diseases among high-risk injection drug users.
Ricky N. Bluthenthal - One of the best experts on this subject based on the ideXlab platform.
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Higher syringe coverage is associated with lower odds of HIV risk and does not increase unsafe syringe disposal among syringe exchange program clients
Drug and Alcohol Dependence, 2007Co-Authors: Ricky N. Bluthenthal, Neil M. Flynn, Rachel Anderson, Alex H KralAbstract:Abstract Objective To determine if adequate syringe coverage – “one shot for one syringe” – among syringe exchange program (SEP) clients is associated with injection-related HIV risk behaviors and syringe disposal. Design HIV risk assessments with 1577 injection drug users (IDUs) recruited from 24 SEPs in California between 2001 and 2003. Individual syringe coverage was calculated as a proportion of Syringes retained from SEP visits to total number of injections in the last 30 days. Results Participants were divided into four groups based on syringe coverage: Conclusions Individual syringe coverage is strongly associated with safer injection behaviors without impacting syringe disposal among SEP clients. Syringe coverage is a useful measure for determining if IDUs are obtaining sufficient Syringes to lower HIV risk.
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examination of the association between syringe exchange program sep dispensation policy and sep client level syringe coverage among injection drug users
Addiction, 2007Co-Authors: Neil M. Flynn, Rachel Anderson, Ricky N. Bluthenthal, Alex H Kral, Greg Ridgeway, Terry L SchellAbstract:Aim To determine whether syringe exchange programs' (SEPs) dispensation policy is associated with syringe cover- age among SEP clients. Design Cross-sectional samples of SEPs and their clients. Setting SEPs in California, USA. Participants Twenty-four SEPs and their injection drug using (IDU) clients (n = 1576). Measurements Clients were classified as having adequate syringe coverage if they received at least as many Syringes from the SEP as their self- reported injections in the last 30 days. SEPs were classified based on their syringe dispensation policy. Dispensation schemes ranging from least restrictive to most are: unlimited needs-based distribution; unlimited one-for-one exchange plus a few additional Syringes; per visit limited one-for-one plus a few additional Syringes; unlimited one-for-one exchange; and per visit limited one-for-one exchange. Findings Adequate syringe coverage among SEP clients by dispensation policy is as follows: unlimited needs-based distribution = 61%; unlimited one-for-one plus = 50%; limited one-for-one plus = 41%; unlimited one-for-one = 42%; and limited one-for-one = 26%. In multivariate analysis, adequate syringe coverage was significantly higher for all dispensation policies compared to per visit limited one-for- one exchange. Using propensity scoring methods, we compared syringe coverage by dispensation policies while con- trolling for client-level differences. Providing additional Syringes above one-for-one exchange (50% versus 38%, P = 0.009) and unlimited exchange (42% versus 27%, P = 0.05) generally resulted in more clients having adequate syringe coverage compared to one-for-one exchange and per visit limits. Conclusion Providing less restrictive syringe dispensation is associated with increased prevalence of adequate syringe coverage among clients. SEPs should adopt syringe dispensation policies that provide IDUs sufficient Syringes to attain adequate syringe coverage.
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the effect of syringe exchange use on high risk injection drug users a cohort study
AIDS, 2000Co-Authors: Ricky N. Bluthenthal, Alex H Kral, Lauren Gee, Elizabeth A Erringer, Brian R EdlinAbstract:OBJECTIVE To determine whether syringe exchange program use is associated with cessation of syringe sharing among high-risk injection drug users. DESIGN AND METHODS Between 1992 and 1996, street-recruited injection drug users were interviewed and received HIV testing and counseling semi-annually, as part of a dynamic cohort study. We examined a cohort of 340 high-risk injection drug users for whom two observations, 6-months apart, were available and who reported syringe sharing at the first interview. Multivariate logistic regression analysis was performed to determine the relationship between syringe exchange program use and cessation of syringe sharing, while controlling for confounding factors. RESULTS At follow-up interview, 60% (204 of 340) reported quitting syringe sharing. High-risk injection drug users who began using the syringe exchange program were more likely to quit sharing Syringes [adjusted odds ratio (AOR), 2.68; 95% confidence interval (CI), 1.35-5.33], as were those who continued using the syringe exchange program (AOR,1.98; 95% CI, 1.05-3.75) in comparison with non-syringe exchange program users, while controlling for confounding factors. CONCLUSIONS The initiation and continuation of syringe exchange program use among high-risk injection drug users is independently associated with cessation of syringe sharing. Syringe exchange program use can be an important component in reducing the spread of blood-borne infectious diseases among high-risk injection drug users.
John F Carpenter - One of the best experts on this subject based on the ideXlab platform.
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impact of sterilization method on protein aggregation and particle formation in polymer based Syringes
Journal of Pharmaceutical Sciences, 2017Co-Authors: Hideaki Kiminami, Keisuke Yoshino, Aaron B Krueger, John F CarpenterAbstract:The effects of sterilization methods on the storage stability of erythropoietin (EPO) in polymer-based Syringes were assessed by quantifying protein oxidation, aggregation, and particle formation. Micro-particle counting and size exclusion chromatography coupled with a multi-angle light scattering detector demonstrated much lower levels of protein particles and aggregates for EPO stored for 12 weeks in steam-sterilized than in radiation (Rad)-sterilized Syringes. Intermediate levels of damage were observed for EPO stored in ethylene oxide-sterilized Syringes. HPLC analysis documented that the Rad-sterilized Syringes caused increased oxidation of the protein during storage. In contrast, in the steam- and ethylene oxide-sterilized Syringes EPO oxidation did not change. Analysis with electron spin resonance revealed that only Rad-sterilized Syringes formed radicals in the syringe body, which persisted over the 12-week storage period. These results demonstrated that Rad-sterilization generated radicals in the Syringes which in turn caused increased EPO oxidation, particle formation, and protein aggregation. Therefore, steam sterilization was shown to be a preferable sterilization method for the polymer-based syringe system when using biopharmaceutical drugs highly sensitive to oxidation, and particle formation and aggregation.
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Aggregation and Particle Formation of Therapeutic Proteins in Contact With a Novel Fluoropolymer Surface Versus Siliconized Surfaces: Effects of Agitation in Vials and in Prefilled Syringes
Journal of Pharmaceutical Sciences, 2016Co-Authors: Brandon M. Teska, Jeffrey M. Brake, Gregory S. Tronto, John F CarpenterAbstract:We examined the effects of an accelerated agitation protocol on 2 protein therapeutics, intravenous immunoglobulin (IVIG) and Avastin (bevacizumab), in contact with a novel fluoropolymer surface and more typical siliconized surfaces. The fluoropolymer surface provides “solid-phase” lubrication for the syringe plunger—obviating the need for silicone oil lubrication in prefilled Syringes. We tested the 2 surfaces in a vial system and in prefilled glass Syringes. We also examined the effects of 2 buffers, phosphate-buffered saline (PBS) and 0.2-M glycine, with and without the addition of polysorbate 20, on agitation-induced aggregation of IVIG. Aggregation was monitored by measuring subvisible particle formation and soluble protein loss. In both vials and Syringes, protein particle formation was much lower during agitation with the fluoropolymer surface than with the siliconized surface. Also, particle formation was greater in PBS than in glycine buffer, an effect attributed to lower colloidal stability of IVIG in PBS. Polysorbate 20 in the formulation greatly inhibited protein particle formation. Overall, the fluoropolymer plunger surface in an unsiliconized glass barrel was demonstrated to be a viable solution for eliminating silicone oil droplets from prefilled syringe formulations and providing a consistent system for rationale formulation development and simplified particle analysis.
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effect of the siliconization method on particle generation in a monoclonal antibody formulation in pre filled Syringes
Journal of Pharmaceutical Sciences, 2015Co-Authors: Alana Gerhardt, John F Carpenter, Bao H Nguyen, Rachael Lewus, Theodore W RandolphAbstract:Silicone oil is used as a lubricant in glass pre-filled Syringes (PFS) but can contribute to the generation of particles within protein formulations in PFS. To mitigate the production of such particles, various silicone oil coating processes have been proposed. In this study, three siliconization methods (the "covalent" method, the "baked silicone oil" method, and the "liquid silicone oil" method) were used to coat glass Syringes with silicone oil. Glide forces were determined for Syringes coated by each method. Then, a monoclonal antibody formulation or a buffer solution were incubated in the coated Syringes in either the presence or absence of an air bubble, and the Syringes were rotated end-over-end to induce air bubble movement within the syringe. The particle concentrations were measured throughout the incubation period using flow microscopy. The coating method did not affect particle concentrations measured in buffer alone, nor did the coating method affect particle concentrations measured in antibody formulations in the absence of an air bubble. Particle concentrations were influenced by the syringe coating method in protein formulations agitated in the presence of an air bubble, with the most particles formed in Syringes lubricated with liquid silicone oil. Fewer particles were produced in Syringes lubricated with baked silicone oil, and the fewest particles were produced in Syringes with covalently-attached silicone oil. However, the glide forces measured in Syringes coated with silicone oil by each method are inversely correlated with the measured particle concentrations.
Don Des C Jarlais - One of the best experts on this subject based on the ideXlab platform.
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doing harm reduction better syringe exchange in the united states
Addiction, 2009Co-Authors: Don Des C Jarlais, Courtney Mcknight, Cullen Goldblatt, David PurchaseAbstract:Objective To trace the growth of syringe exchange programs (SEPs) in the United States since 1994–95 and assess the current state of SEPs.Methods Annual surveys of US SEPs known to North American Syringe Exchange Network (NASEN). Surveys mailed to executive directors with follow-up interviews by telephone and/or e-mail. Response rates have varied between 70% and 88% since surveys were initiated in 1996. Results The numbers of programs known to NASEN have increased from 68 in 1994–95 to 186 in 2007. Among programs participating in the survey, numbers of Syringes exchanged have increased from 8.0 million per year to 29.5 million per year, total annual budgets have increased from $6.3 to $19.6 million and public funding (from state and local governments) has increased from $3.9 to $14.4 million. In 2007, 89% of programs permitted secondary exchange and 76% encouraged it. Condoms, referrals to substance abuse treatment, human immunodeficiency virus (HIV), hepatitis C virus (HCV), hepatitis B virus (HBV) counseling and testing and naloxone for overdose were among the most commonly provided services in addition to basic syringe exchange. Each of these services was provided by 40% or more of SEPs in 2007. Conclusions While syringe exchange has remained controversial in the United States, there has been very substantial growth in numbers of programs, Syringes exchange and program budgets. Utilizing secondary exchange to reach large numbers of injecting drug users and utilizing SEPs as a new platform for providing health and social services beyond basic syringe exchange have been the two major organizational strategies in the growth of SEPs in the United States.
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hiv incidence among injection drug users in new york city 1990 to 2002 use of serologic test algorithm to assess expansion of hiv prevention services
American Journal of Public Health, 2005Co-Authors: Don Des C Jarlais, Theresa Perlis, Judith Milliken, Kamyar Arasteh, Lucia V Torian, Sara Beatrice, Donna Mildvan, Stanley R Yancovitz, Samuel R FriedmanAbstract:Objectives. We sought to estimate HIV incidence among injection drug users (IDUs) in New York City from 1990 to 2002 to assess the impact of an expansion of syringe exchange services. Syringe exchange increased greatly during this period, from 250000 to 3000000 Syringes exchanged annually.Methods. Serum samples were obtained from serial cross-sectional surveys of 3651 IDUs. HIV-positive samples were tested with the Serologic Test Algorithm for Recent HIV Seroconversion (STARHS) assay to identify recent HIV infections and to estimate HIV incidence. Consistency with other incidence studies was used to assess strengths and limitations of STARHS.Results. HIV incidence declined from 3.55/100 person-years at risk (PYAR) from 1990–1992, to 2.63/100 PYAR from 1993–1995, to 1.05/100 PYAR from 1996–1998, and to 0.77/100 PYAR from 1999–2002 (P<.001). There was a very strong negative linear relationship (r= −.99, P<.005) between the annual numbers of Syringes exchanged and estimated HIV incidence. These results were ...
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hiv risk behaviour among participants of syringe exchange programmes in central eastern europe and russia
International Journal of Drug Policy, 2002Co-Authors: Don Des C Jarlais, Theresa Perlis, Jean-paul C. Grund, Catherine Zadoretzky, Judith Milliken, Patricia Friedmann, Stephen P. Titus, Valentina Bodrova, Elena ZemlianovaAbstract:Abstract Objective: To assess HIV risk behaviour among participants in syringe exchanges in five Central/Eastern European cities: Prague (Czech Republic), Budapest (Hungary), Skopje (Former Yugoslavian Republic of Macedonia), Krakow (Poland) and Poltava (Ukraine), and five Russian cities: Nizhniy Novgorod, Pskov, Rostov-Na-Donu, St. Petersburg, and Volgograd. Design: Cross-sectional survey with questions on injection risk behaviours for the 30 days prior to first use of the syringe exchange programme and for the 30 days prior to interview (while using the syringe exchange programme). Methods: Respondents were recruited from participants of the syringe exchanges. Structured questionnaires covering drug use and HIV risk behaviour were administered by trained interviewers. Results: 1671 respondents were interviewed across the ten programmes. Participants in the programmes tended to be young and relatively recent initiates into drug injection. Relatively low percentages of participants reported receptive syringe sharing (‘injecting with needles and Syringes used by others') in the past 30 days, from 1 to 29% across the ten programmes. These represented statistically significant reductions from the percentages of respondents reporting receptive syringe sharing in the 30 days prior to first use of the syringe exchange—from 7 to 47%. Conclusions: IDUs participating in the exchanges appear to be responding very positively in reducing sharing of needles and Syringes. Syringe exchange and other HIV prevention programmes for injecting drug users (IDUs) in this geographic region should be expanded rapidly.
