The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
M G Rinaldi - One of the best experts on this subject based on the ideXlab platform.
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quality control guidelines for national committee for Clinical Laboratory standards recommended broth macrodilution testing of ketoconazole and itraconazole
Journal of Clinical Microbiology, 1996Co-Authors: John H Rex, Michael A Pfaller, M Lancaster, F C Odds, A Bolmstrom, M G RinaldiAbstract:Ketoconazole and itraconazole were tested in a multiLaboratory study to establish quality control (QC) guidelines for yeast antifungal susceptibility testing. Two isolates that had been previously identified as QC isolates for amphotericin B, fluconazole, and flucytosine (Candida parapsilosis ATCC 22019 and Candida krusei ATCC 6258) were tested in accordance with the National Committee for Clinical Laboratory Standards M27-P guidelines. Each isolate was tested 20 times with the two antifungal agents in the five laboratories by using a lot of RPMI 1640 unique to each Laboratory as well as a lot common to all five laboratories, thus generating 200 MICs per drug per organism. Overall, 96 to 99% of the MICs for each drug fell within the desired 3-log2 dilution range (mode +/- 1 log2 dilution). By using these data, 3-log2 dilution QC ranges encompassing 98% of the observed MICs for three of the organism-drug combinations and 94% of the observed MICs for the fourth combination were established. These QC ranges are 0.064 to 0.25 micrograms/ml for both ketoconazole and itraconazole against C. parapsilosis ATCC 22019 and 0.125 to 0.5 micrograms/ml for both ketoconazole and itraconazole against C. krusei ATCC 6258.
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selection of candidate quality control isolates and tentative quality control ranges for in vitro susceptibility testing of yeast isolates by national committee for Clinical Laboratory standards proposed standard methods
Journal of Clinical Microbiology, 1994Co-Authors: Michael A Pfaller, Martha J Bale, Barry J Buschelman, M Lancaster, A Espinelingroff, John H Rex, M G RinaldiAbstract:The National Committee for Clinical Laboratory Standards has developed a proposed standard method for in vitro antifungal susceptibility testing of yeast isolates (National Committee for Clinical Laboratory Standards, document M27-P, 1992). In order for antifungal testing by the M27-P method to be accepted, reliable quality control (QC) performance criteria must be developed. In the present study, five laboratories tested 10 candidate QC strains 20 times each against three antifungal agents: amphotericin B, fluconazole, and 5-fluorocytosine. All sites conformed to the M27-P standards and used a common lot of tube dilution reagents and RPMI 1640 broth medium. Overall, 98% of MIC results with amphotericin B, 95% with fluconazole, and 92% with 5-fluorocytosine fell within the desired 3-log2 dilution range (mode +/- 1 log2 dilution). Excellent performance with all three antifungal agents was observed for six strains: Candida albicans ATCC 90028, Candida parapsilosis ATCC 90018, C. parapsilosis ATCC 22019, Candida krusei ATCC 6258, Candida tropicalis ATCC 750, and Saccharomyces cerevisiae ATCC 9763. With these strains, 3-log2 dilution ranges encompassing 94 to 100% of MICs for all three drugs were established. Additional studies with multiple lots of RPMI 1640 test medium will be required to establish definitive QC ranges.
Thomas Eissenberg - One of the best experts on this subject based on the ideXlab platform.
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expanding Clinical Laboratory tobacco product evaluation methods to loose leaf tobacco vaporizers
Drug and Alcohol Dependence, 2016Co-Authors: Alexa A Lopez, Thomas Eissenberg, Marzena M Hiler, Sarah F Maloney, Alison B BrelandAbstract:Abstract Background Novel tobacco products entering the US market include electronic cigarettes (ECIGs) and products advertised to “heat, not burn” tobacco. There is a growing literature regarding the acute effects of ECIGs. Less is known about “heat, not burn” products. This study’s purpose was to expand existing Clinical Laboratory methods to examine, in cigarette smokers, the acute effects of a “heat, not burn” “loose-leaf tobacco vaporizer” (LLTV). Methods Plasma nicotine and breath carbon monoxide (CO) concentration and tobacco abstinence symptom severity were measured before and after two 10-puff (30-s interpuff interval) product use bouts separated by 60 min. LLTV effects were compared to participants’ own brand (OB) cigarettes and an ECIG (3.3 V; 1.5 ohm; 18 mg/ml nicotine). Results Relative to OB, LLTV increased plasma nicotine concentration to a lesser degree, did not increase CO, and did not appear to reduce abstinence symptoms as effectively. Relative to ECIG, LLTV nicotine and CO delivery and abstinence symptom suppression did not differ. Participants reported that both the LLTV and ECIG were significantly less satisfying than OB. Conclusions Results demonstrate that LLTVs are capable of delivering nicotine and suppressing tobacco abstinence symptoms partially; acute effects of these products can be evaluated using existing Clinical Laboratory methods. Results can inform tobacco product regulation and may be predictive of the extent that these products have the potential to benefit or harm overall public health.
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Clinical Laboratory assessment of the abuse liability of an electronic cigarette
Addiction, 2012Co-Authors: Andrea R Vansickel, Michael F Weaver, Thomas EissenbergAbstract:Aims To provide an initial abuse liability assessment of an electronic cigarette (EC) in current tobacco cigarette smokers. Design The first of four within-subject sessions was an EC sampling session that involved six, 10-puff bouts (30 seconds inter-puff interval), each bout separated by 30 minutes. In the remaining three sessions participants made choices between 10 EC puffs and varying amounts of money, 10 EC puffs and a varying number of own brand cigarette (OB) puffs, or 10 OB puffs and varying amounts of money using the multiple-choice procedure (MCP). The MCP was completed six times at 30-minute intervals, and one choice was reinforced randomly at each trial. Setting Clinical Laboratory. Participants Twenty current tobacco cigarette smokers. Measurements Sampling session outcome measures included plasma nicotine, cardiovascular response and subjective effects. Choice session outcome was the cross-over value on the MCP. Findings EC use resulted in significant nicotine delivery, tobacco abstinence symptom suppression and increased product acceptability ratings. On the MCP, participants chose to receive 10 EC puffs over an average of $1.06 or three OB puffs and chose 10 OB puffs over an average of $1.50 (P < 0.003). Conclusions Electronic cigarettes can deliver Clinically significant amounts of nicotine and reduce cigarette abstinence symptoms and appear to have lower potential for abuse relative to traditional tobacco cigarettes, at least under certain Laboratory conditions.
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a Clinical Laboratory model for evaluating the acute effects of electronic cigarettes nicotine delivery profile and cardiovascular and subjective effects
Cancer Epidemiology Biomarkers & Prevention, 2010Co-Authors: Andrea R Vansickel, Michael F Weaver, Caroline O Cobb, Thomas EissenbergAbstract:Background: Electronic “cigarettes” are marketed to tobacco users as potential reduced exposure products (PREP), albeit with little information regarding electronic cigarette user toxicant exposure and effects. This information may be obtained by adapting Clinical Laboratory methods used to evaluate other PREPs for smokers. Methods: Thirty-two smokers participated in four independent Latin-square ordered conditions that differed by product: own brand cigarette, “NPRO” electronic cigarettes (NPRO EC; 18 mg cartridge), “Hydro” electronic cigarettes (Hydro EC; 16 mg cartridge), or sham (unlit cigarette). Participants took 10 puffs at two separate times during each session. Plasma nicotine and carbon monoxide (CO) concentration, heart rate, and subjective effects were assessed. Results: Own brand significantly increased plasma nicotine and CO concentration and heart rate within the first five minutes of administration whereas NPRO EC, Hydro EC, and sham smoking did not. Own brand, NPRO EC, and Hydro EC (but not sham) significantly decreased tobacco abstinence symptom ratings and increased product acceptability ratings. The magnitude of symptom suppression and increased acceptability was greater for own brand than for NPRO EC and Hydro EC. Conclusions: Under these acute testing conditions, neither of the electronic cigarettes exposed users to measurable levels of nicotine or CO, although both suppressed nicotine/tobacco abstinence symptom ratings. Impact: This study illustrates how Clinical Laboratory methods can be used to understand the acute effects of these and other PREPs for tobacco users. The results and methods reported here will likely be relevant to the evaluation and empirically based regulation of electronic cigarettes and similar products. Cancer Epidemiol Biomarkers Prev; 19(8); OF1–9. ©2010 AACR.
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Clinical Laboratory evaluation of potential reduced exposure products for smokers
Nicotine & Tobacco Research, 2006Co-Authors: Alison B Breland, Bethea A Kleykamp, Thomas EissenbergAbstract:Smoking-related cancer and other disease account for more than 400,000 U.S. deaths annually. Smoking cessation reduces smoking-related disease rates, but relapse rates are high. Thus, interest in reducing the harm of continued smoking is growing. Potential reduced exposure products (PREPs) are marketed to reduce smokers' exposure to smoke toxicants such as carbon monoxide (CO) and carcinogens and may be harm reduction tools. New PREPs are proliferating, but past experience with "low-yield" cigarettes that failed to reduce smokers' toxicant exposure suggests that comprehensive evaluation is necessary to predict if these new products are likely to alter the harm caused by smoking. The purpose of the study was to develop Clinical Laboratory methods for PREP evaluation. Smokers (N = 35) completed four, 5-day conditions that differed by product used: Advance, Eclipse, own brand cigarettes, or no cigarettes. Carcinogen (as assessed by one nitrosamine and one polycyclic aromatic hydrocarbon biomarker) and nicotine exposure were assessed via thrice-weekly urine sampling. Withdrawal symptoms were measured daily, and smoking behavior was assessed on the first and last day of each condition. Relative to own brand, Advance reduced exposure to the nitrosamine NNK and CO, and Eclipse reduced exposure to nicotine and the nitrosamine NNK, increased exposure to CO, and resulted in larger, longer, and more frequent puffs. No smoking reduced exposure to the nitrosamine NNK, CO, and nicotine, whereas withdrawal was elevated (all p values <.05). Clinical Laboratory evaluation of PREPs for smokers is valuable for measuring users' smoke toxicant exposure, withdrawal, and smoking behavior and should be incorporated into a comprehensive PREP evaluation strategy.
Brett Lowe - One of the best experts on this subject based on the ideXlab platform.
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implementation of good Clinical Laboratory practice in an immunology basic research Laboratory the kemri wellcome trust research laboratories experience
American Journal of Clinical Pathology, 2019Co-Authors: Horace Gumba, Jennifer N Musyoki, Moses Mosobo, Brett LoweAbstract:Objectives Good Clinical Laboratory Practice (GCLP) is a standard that ensures quality and reliability of research data by adopting the principles of Good Laboratory Practice and Good Clinical Practice. Even though implementing a quality system in a basic research Laboratory is still a contentious issue, it ensures that the research data are accurate, valid, and reliable. GCLP implementation requires proper documented procedures and safety precautions to achieve this objective.
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implementing a quality management system using good Clinical Laboratory practice guidelines at kemri cmr to support medical research
Wellcome Open Research, 2018Co-Authors: Horace Gumba, Brett Lowe, Joseph Waichungo, Alfred Mwanzu, Robert Musyimi, Johnstone Thitiri, Caroline Tigoi, Martin Kamui, James A BerkleyAbstract:Background: Good Clinical Laboratory Practice (GCLP) is a standard that helps ensure the quality and reliability of research data through principles of Good Laboratory Practice (GLP) and Good Clinical Practice (GCP). The implementation of GCLP includes careful documentation of procedures, competencies and safety measures. Implementation of GCLP is influenced by existing resources and quality systems, thus laboratories in low- and middle-income countries may face additional challenges. Methods: This paper describes implementation of Good Clinical Laboratory Practice (GCLP) at the Kenya Medical Research Institute-Center for Microbiology Research (KEMRI-CMR) as part of a quality system to support medical research. This study employed assessment, twinning (institutional mentorship) model, conducting relevant training workshops and Kaizen 5S approaches to implement an effective quality management system using GCLP standard. This was achieved through a collaboration between the KEMRI/Wellcome Trust Research Programme (KWTRP) and KEMRI-CMR. The aim was compliance and continuous monitoring to meet international GCLP standards in a way that could be replicated in other research organizations. Results: Following a baseline assessment in March 2017, training, mentorship and a cycle of quality audit and corrective action using a Kaizen 5S approach (sorting, setting in order, shining, standardizing and sustaining) was established. Laboratory personnel were trained in writing standard operating procedures and analytical plans, microbiological techniques, and good documentation practice. Mid-term and exit assessments demonstrated significant declines in non-conformances across all GCLP elements. KEMRI-CMR achieved GCLP accreditation in May 2018 by Qualogy Ltd (UK). Conclusions: Involving all the Laboratory personnel in implementation of quality management system processes is critical to success. An institutional mentorship (twinning) approach shows potential for future collaborations between accredited and non-accredited organizations to accelerate the implementation of high-quality management systems and continuous improvement.
Robert L Fitzgerald - One of the best experts on this subject based on the ideXlab platform.
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effective use of mass spectrometry in the Clinical Laboratory
Clinical Chemistry, 2016Co-Authors: Paul J Jannetto, Robert L FitzgeraldAbstract:Background: Historically the success of mass spectrometry in the Clinical Laboratory has focused on drugs of abuse confirmations, newborn screening, and steroid analysis. Clinical applications of mass spectrometry continue to expand, and mass spectrometry is now being used in almost all areas of Laboratory medicine. Content: A brief background of the evolution of mass spectrometry in the Clinical Laboratory is provided with a discussion of future applications. Prominent examples of mass spectrometry are covered to illustrate how it has improved the practice of medicine and enabled physicians to provide better patient care. With increasing economic pressures and decreasing Laboratory test reimbursement, mass spectrometry testing has been shown to provide cost-effective solutions. In addition to pointing out the numerous benefits, the challenges of implementing mass spectrometry in the Clinical Laboratory are also covered. Summary: Mass spectrometry continues to play a prominent role in the field of Laboratory medicine. The advancement of this technology along with the development of new applications will only accelerate the incorporation of mass spectrometry into more areas of medicine.
Alison B Breland - One of the best experts on this subject based on the ideXlab platform.
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expanding Clinical Laboratory tobacco product evaluation methods to loose leaf tobacco vaporizers
Drug and Alcohol Dependence, 2016Co-Authors: Alexa A Lopez, Thomas Eissenberg, Marzena M Hiler, Sarah F Maloney, Alison B BrelandAbstract:Abstract Background Novel tobacco products entering the US market include electronic cigarettes (ECIGs) and products advertised to “heat, not burn” tobacco. There is a growing literature regarding the acute effects of ECIGs. Less is known about “heat, not burn” products. This study’s purpose was to expand existing Clinical Laboratory methods to examine, in cigarette smokers, the acute effects of a “heat, not burn” “loose-leaf tobacco vaporizer” (LLTV). Methods Plasma nicotine and breath carbon monoxide (CO) concentration and tobacco abstinence symptom severity were measured before and after two 10-puff (30-s interpuff interval) product use bouts separated by 60 min. LLTV effects were compared to participants’ own brand (OB) cigarettes and an ECIG (3.3 V; 1.5 ohm; 18 mg/ml nicotine). Results Relative to OB, LLTV increased plasma nicotine concentration to a lesser degree, did not increase CO, and did not appear to reduce abstinence symptoms as effectively. Relative to ECIG, LLTV nicotine and CO delivery and abstinence symptom suppression did not differ. Participants reported that both the LLTV and ECIG were significantly less satisfying than OB. Conclusions Results demonstrate that LLTVs are capable of delivering nicotine and suppressing tobacco abstinence symptoms partially; acute effects of these products can be evaluated using existing Clinical Laboratory methods. Results can inform tobacco product regulation and may be predictive of the extent that these products have the potential to benefit or harm overall public health.
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Clinical Laboratory evaluation of potential reduced exposure products for smokers
Nicotine & Tobacco Research, 2006Co-Authors: Alison B Breland, Bethea A Kleykamp, Thomas EissenbergAbstract:Smoking-related cancer and other disease account for more than 400,000 U.S. deaths annually. Smoking cessation reduces smoking-related disease rates, but relapse rates are high. Thus, interest in reducing the harm of continued smoking is growing. Potential reduced exposure products (PREPs) are marketed to reduce smokers' exposure to smoke toxicants such as carbon monoxide (CO) and carcinogens and may be harm reduction tools. New PREPs are proliferating, but past experience with "low-yield" cigarettes that failed to reduce smokers' toxicant exposure suggests that comprehensive evaluation is necessary to predict if these new products are likely to alter the harm caused by smoking. The purpose of the study was to develop Clinical Laboratory methods for PREP evaluation. Smokers (N = 35) completed four, 5-day conditions that differed by product used: Advance, Eclipse, own brand cigarettes, or no cigarettes. Carcinogen (as assessed by one nitrosamine and one polycyclic aromatic hydrocarbon biomarker) and nicotine exposure were assessed via thrice-weekly urine sampling. Withdrawal symptoms were measured daily, and smoking behavior was assessed on the first and last day of each condition. Relative to own brand, Advance reduced exposure to the nitrosamine NNK and CO, and Eclipse reduced exposure to nicotine and the nitrosamine NNK, increased exposure to CO, and resulted in larger, longer, and more frequent puffs. No smoking reduced exposure to the nitrosamine NNK, CO, and nicotine, whereas withdrawal was elevated (all p values <.05). Clinical Laboratory evaluation of PREPs for smokers is valuable for measuring users' smoke toxicant exposure, withdrawal, and smoking behavior and should be incorporated into a comprehensive PREP evaluation strategy.