Last data update: May 06, 2024. (Total: 46732 publications since 2009)
Records 1-5 (of 5 Records) |
Query Trace: Flores SR[original query] |
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Harmonization of acronyms for volatile organic compound metabolites using a standardized naming system
Tevis DS , Flores SR , Kenwood BM , Bhandari D , Jacob P3rd , Liu J , Lorkiewicz PK , Conklin DJ , Hecht SS , Goniewicz ML , Blount BC , De Jesús VR . Int J Hyg Environ Health 2021 235 113749 Increased interest in volatile organic compound (VOC) exposure has led to an increased need for consistent, systematic, and informative naming of VOC metabolites. As analytical methods have expanded to include many metabolites in a single assay, the number of acronyms in use for a single metabolite has expanded in an unplanned and inconsistent manner due to a lack of guidance or group consensus. Even though the measurement of VOC metabolites is a well-established means to investigate exposure to VOCs, a formal attempt to harmonize acronyms amongst investigators has not been published. The aim of this work is to establish a system of acronym naming that provides consistency in current acronym usage and a foundation for creating acronyms for future VOC metabolites. |
Glucose-6-phosphate dehydrogenase enzyme stability in filter paper dried blood spots
Flores SR , Hall EM , De Jesus VR . Clin Biochem 2017 50 (15) 878-881 OBJECTIVE: Prior to initial distribution of Glucose-6-phosphate dehydrogenase (G6PD) proficiency testing (PT) materials, we evaluated G6PD enzyme stability in dried blood spots (DBS) under various temperature and humidity environments to develop storage and usage guidelines for our new materials. DESIGN & METHODS: We prepared fresh G6PD-normal DBS materials and conducted stability evaluations of daily use and short and long-term storage under various temperature and humidity environments. RESULTS: G6PD DBS PT materials retained 92% of initial activity after 30days of use at 4 degrees C. Materials stored at -20 degrees C and 4 degrees C with desiccant for 30days retained 95% and 90% of initial activity, respectively. When stored for one year at -20 degrees C or six months at 4 degrees C specimens retained >90% of initial activity. Specimens stored at 37 degrees C with desiccant lost 10% activity in three days. At the end of 30days, specimens stored under 'Extreme'-humidity >50% without desiccant- conditions at 37 degrees C assayed below the NSQAP cut off for G6PD. Humidity exacerbated loss of enzyme activity with increasing temperature and time duration. CONCLUSION: Data suggest that G6PD PT materials can be stored at 4 degrees C and used for up to one month and can be stored at -20 degrees C for one year and yield >90% enzyme activity. Exposure to warm temperatures, especially with elevated humidity, should be avoided. Desiccant should always be used to mitigate humidity effects. |
Influence of Hematocrit and Total-Spot Volume on Performance Characteristics of Dried Blood Spots for Newborn Screening
Hall EM , Flores SR , De Jesús VR . Int J Neonatal Screen 2015 1 (2) 69-78 Dried blood spots (DBS) have been used in newborn screening (NBS) tests for over 50 years. The Newborn Screening Quality Assurance Program (NSQAP) at the Centers for Disease Control and Prevention (CDC) conducted studies to assess the individual impacts of hematocrit and total-spot volume on characteristics of DBS samples. Per-punch serum volumes decreased 27%, RBC volumes more than doubled, absorption times increased over 300%, and spot diameters decreased marginally between the hematocrits of 40% to 65%. Per-punch serum and RBC volumes decreased logarithmically with lowering total-spot volumes. Patient hematocrit is an uncontrollable variable and inevitably affects the resulting punch from a DBS sample. It may be possible, though, to identify samples that fall outside of an acceptable range by noting certain physical characteristics of the DBS. |
Galactose-1-phosphate uridyltransferase dried blood spot quality control materials for newborn screening tests
Adam BW , Flores SR , Hou Y , Allen TW , De Jesus VR . Clin Biochem 2014 48 (6) 437-42 OBJECTIVES: We aimed to prepare dried-blood-spot (DBS) quality control (QC) materials for galactose-1-phosphate uridyltransferase (GALT), to evaluate their stability during storage and use, and to evaluate their performance in five DBS GALT test methods. DESIGN AND METHODS: We prepared and characterized GALT-normal and GALT-deficient DBS materials and compared GALT activities in DBSs after predetermined storage intervals at controlled temperatures and humidities. External evaluators documented the suitability of the DBS QC materials for use in five GALT test methods. RESULTS: GALT activity losses from DBSs stored in low (<30%) humidity for 14days at 45 degrees C, 35days at 37 degrees C, 91days at room temperature, 182days at 4 degrees C, and 367days at -20 degrees C were 54%, 53%, 52% 23%, and 7% respectively. In paired DBSs stored in high humidity (>50%) for identical intervals, losses were: 45 degrees C-68%; 37 degrees C-79%; room temperature-72%, and 4 degrees C-63%. GALT activities in DBSs stored at 4 degrees C were stable throughout 19 excursions to room temperature. Twenty-five of 26 external evaluators, using five different GALT test methods, classified the GALT-deficient DBSs as "outside normal limits". All evaluators classified the GALT-normal DBSs as "within normal limits". CONCLUSIONS: Most of the GALT activity loss from DBSs stored at elevated or room temperature was attributable to the effects of storage temperature. Most of the loss from DBSs stored at 4 degrees C was attributable to the effects of elevated humidity. Loss from DBSs stored at -20 degrees C was insignificant. The DBS materials were suitable for monitoring performance of all five GALT test methods. |
The stability of markers in dried-blood spots for recommended newborn screening disorders in the United States
Adam BW , Hall EM , Sternberg M , Lim TH , Flores SR , O'Brien S , Simms D , Li LX , De Jesus VR , Hannon WH . Clin Biochem 2011 44 1445-50 OBJECTIVE: We aimed to measure separately the contributions of heat and humidity to changes in levels of 34 markers of inborn disorders in dried-blood-spot (DBS) samples. DESIGN AND METHODS: We stored paired sets of DBSs at 37 degrees C for predetermined intervals in low-humidity and high-humidity environments. Marker levels of all samples in each complete sample set were measured in a single analytic run. RESULTS: During the 30+/-5day studies, galactose-1-phosphate uridyltransferase and biotinidase lost almost 65% of initial activities in low-humidity storage; most of the degradation in 27 other markers was attributable to adverse effects of high-humidity storage; seven markers in DBSs stored at high humidity lost more than 90% of initial levels by the end of the study and 4 of the 7 lost more than 50% of initial levels within the first week of storage. CONCLUSIONS: Minimizing both humidity and temperature in DBS transportation and storage environments is essential to maintaining sample integrity. |
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