Scholars@Duke

• Background
• 

  Education, Training, & Certifications

  • Assistant Professor of Pathology, Pathology, Duke University 1979 - 1986
  • Postdoctoral Fellow, Clinical Chemistry, University of North Carolina - Chapel Hill 1977 - 1979
  • Ph.D., University of North Carolina - Chapel Hill 1977
  • B.S., University of Florida 1972
• 

  Previous Appointments & Affiliations

  • Associate Professor of Pathology with Tenure, Pathology, Clinical Science Departments 1989 - 2005
• Research
• 

  Selected Grants

  • GEM® Premier¿ 5000 Critical Care System Pleural Fluid pH External Method Comparison Protoco awarded by Instrumentation Laboratory Company 2018 - 2019
  • EDAN i15 Compartive Method Study awarded by EDAN Diagnostics, Inc 2016 - 2017
  • GLUCOSE Monitor Meter with the GLUCOSE Monitor Test Strip High Altitude awarded by Roche Laboratories, Inc. 2014 - 2015
  • GLUCOSE Monitor Meter with the GLUCOSE Monitor Test Strip Hyperbaric Chamber Evaluation awarded by Roche Laboratories, Inc. 2014 - 2015
  • GEM Premier 5000 Pre-Beta 2 External Evaluation awarded by Instrumentation Laboratory 2014 - 2015
  • GEM Premier 5000 IUO awarded by Instrumentation Laboratory 2013 - 2014
• 

  External Relationships

  • Becton, Dickinson and Company
  • Nova Biomedical
  • Werfen (formerly Instrumentation Laboratory)
• Publications & Artistic Works
• 

  Selected Publications

  • Academic Articles

    • Toffaletti, John G., Cyril O. Burke, George Bayliss, and Matthew Lynch. “Utilizing Longitudinal Within-Individual Changes of Serum Creatinine, Cystatin C, and/or eGFR to Optimize Clinical Sensitivity and Eliminate Race and Gender Corrections.” J Appl Lab Med 7, no. 3 (May 4, 2022): 807–11. https://doi.org/10.1093/jalm/jfac001.
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    • Toffaletti, John G. “Upping the Game on Validating Automatic Quality Management Systems for Blood Gas and Critical Care Test Analyzers.” J Appl Lab Med 6, no. 6 (November 1, 2021): 1393–95. https://doi.org/10.1093/jalm/jfab088.
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    • Toffaletti, John G., Kelly A. Buckner, Beiyu Liu, and Cynthia L. Green. “Retrospective Analysis of Quality Control Data Using Pooled Blood to Compare Agreement within Two Models of Blood Gas Analyzers.” J Appl Lab Med 6, no. 5 (September 1, 2021): 1228–36. https://doi.org/10.1093/jalm/jfab029.
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    • Toffaletti, John G. “Predicting Ionized Hypocalcemia with Total Calcium: Can "Correction" with Logistical Modeling of Multiple Analytes Do the Trick?” J Appl Lab Med 5, no. 1 (January 1, 2020): 1–3. https://doi.org/10.1373/jalm.2019.030197.
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    • Toffaletti, J. G., and K. A. Buckner. “Using α-Angle and A10 ROTEM Parameters for Earlier Information on Clotting Status in Surgery, Postpartum Hemorrhage, and ICU Patients.” Point of Care 18, no. 2 (June 1, 2019): 56–61. https://doi.org/10.1097/POC.0000000000000188.
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    • Toffaletti, John G., and Kelly A. Buckner. “Use of Earlier-Reported Rotational Thromboelastometry Parameters to Evaluate Clotting Status, Fibrinogen, and Platelet Activities in Postpartum Hemorrhage Compared to Surgery and Intensive Care Patients.” Anesth Analg 128, no. 3 (March 2019): 414–23. https://doi.org/10.1213/ANE.0000000000003499.
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    • Toffaletti, John G., Catherine Hammett-Stabler, and Elizabeth A. Handel. “Effect of beef ingestion by humans on plasma concentrations of creatinine, urea, and cystatin C.” Clin Biochem 58 (August 2018): 26–31. https://doi.org/10.1016/j.clinbiochem.2018.05.016.
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    • Rosenbaum, Matthew W., James G. Flood, Stacy E. F. Melanson, Nikola A. Baumann, Mark A. Marzinke, Alex J. Rai, Joshua Hayden, et al. “Quality Control Practices for Chemistry and Immunochemistry in a Cohort of 21 Large Academic Medical Centers.” Am J Clin Pathol 150, no. 2 (July 3, 2018): 96–104. https://doi.org/10.1093/ajcp/aqy033.
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    • Toffaletti, John G. “Relationships and Clinical Utility of Creatinine, Cystatin C, eGFRs, GFRs, and Clearances.” J Appl Lab Med 2, no. 3 (November 1, 2017): 413–22. https://doi.org/10.1373/jalm.2017.023713.
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    • Toffaletti, John G., Catherine A. Hammett-Stabler, Margaret Gearhart, Kingshuk Roy Choudhury, and Elizabeth A. Handel. “The analytical change in plasma creatinine that constitutes a biologic/physiologic change.” Clin Chim Acta 459 (August 1, 2016): 79–83. https://doi.org/10.1016/j.cca.2016.05.008.
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    • Toffaletti, J. G., and C. R. Rackley. “Monitoring Oxygen Status.” Adv Clin Chem 77 (2016): 103–24. https://doi.org/10.1016/bs.acc.2016.06.003.
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    • Louie, R. F., C. M. Curtis, J. G. Toffaletti, E. A. Handel, R. J. Slingerland, M. J. Fokkert, W. Muller, S. E. Weinert, D. M. Lee, and S. Kotagiri. “Performance Evaluation of a Glucose Monitoring System for Point-of-Care Testing with the Critically Ill Patient Population - A Multicenter Study.” Point of Care 14, no. 1 (March 11, 2015): 37–41. https://doi.org/10.1097/POC.0000000000000045.
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    • Brazg, Ronald, Kristen Hughes, Pamela Martin, Julie Coard, John Toffaletti, Elizabeth McDonnell, Elizabeth Taylor, et al. “Clinical evaluation of the FreeStyle Precision Pro system.” Clin Chim Acta 421 (June 5, 2013): 243–50. https://doi.org/10.1016/j.cca.2013.03.021.
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    • Toffaletti, J. G. “Clarifying the fog of natural and manmade renal function tests: Creatinine, clearances, glomerular filtration rate, and estimated glomerular filtration rate.” Point of Care 10, no. 1 (March 1, 2011): 45–50. https://doi.org/10.1097/POC.0b013e31820f8663.
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    • Toffaletti, John G. “Improving the clinical value of estimating glomerular filtration rate by reporting all values: a contrarian viewpoint.” Nephron Clin Pract 115, no. 3 (2010): c177–81. https://doi.org/10.1159/000313030.
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    • Toffaletti, John G., and Elizabeth H. McDonnell. “Variation of serum creatinine, cystatin C, and creatinine clearance tests in persons with normal renal function.” Clin Chim Acta 395, no. 1–2 (September 2008): 115–19. https://doi.org/10.1016/j.cca.2008.05.020.
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    • Toffaletti, John, and Willem G. Zijlstra. “Misconceptions in reporting oxygen saturation.” Anesth Analg 105, no. 6 Suppl (December 2007): S5–9. https://doi.org/10.1213/01.ane.0000278741.29274.e1.
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    • Toffaletti, John G., Elizabeth H. McDonnell, Lakshmi V. Ramanathan, Judit Tolnai, Rozanna Templin, and Lynn Pompa. “Validation of a quality assessment system for blood gas and electrolyte testing.” Clin Chim Acta 382, no. 1–2 (July 2007): 65–70. https://doi.org/10.1016/j.cca.2007.03.021.
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    • Toffaletti, J. G. “Controlling magnesium in surgery, intensive care, and beyond.” Point of Care 6, no. 2 (June 1, 2007): 129–33. https://doi.org/10.1097/01.poc.0000271402.14936.9b.
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    • Patteril, Mathew, Mark Stafford-Smith, John G. Toffaletti, Barbara Phillips Bute, Carmelo A. Milano, and Ian J. Welsby. “Changing systems for measuring activated clotting times: impact on the clinical practice of heparin anticoagulation during cardiac surgery.” Clin Chim Acta 356, no. 1–2 (June 2005): 218–24. https://doi.org/10.1016/j.cccn.2005.01.019.
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    • Lanzinger, Marcella J., Eugene W. Moretti, Robert F. Wilderman, Habib E. El-Moalem, John G. Toffaletti, and Richard E. Moon. “The relationship between ionized and total serum magnesium concentrations during abdominal surgery.” J Clin Anesth 15, no. 4 (June 2003): 245–49. https://doi.org/10.1016/s0952-8180(03)00059-x.
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    • Boldt, J., A. Goerlach-Graw, G. Halwachs-Baumann, J. Hindinger, R. Leinberger, B. Luebke, D. Nagel, et al. “Multicenter Study on the Analytical Performance of a New Point-of-Care Blood Gas Analyzer.” Plastic Surgical Nursing 2, no. 3 (January 1, 2003): 214–19. https://doi.org/10.1097/00134384-200309000-00012.
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    • Toffaletti, J. G., E. H. McDonnell, I. Welsby, I. R. Shearer, M. H. Sketch, and J. E. Tcheng. “Implementing a New Method for Activated Clotting Time.” Plastic Surgical Nursing 2, no. 2 (January 1, 2003): 125–28. https://doi.org/10.1097/00134384-200306000-00009.
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    • Wang, Sihe, Elizabeth H. McDonnell, Frank A. Sedor, and John G. Toffaletti. “pH effects on measurements of ionized calcium and ionized magnesium in blood.” Arch Pathol Lab Med 126, no. 8 (August 2002): 947–50. https://doi.org/10.5858/2002-126-0947-PEOMOI.
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    • Welsby, Ian J., Elizabeth McDonnell, Habib El-Moalem, Mark Stafford-Smith, and John G. Toffaletti. “Activated clotting time systems vary in precision and bias and are not interchangeable when following heparin management protocols during cardiopulmonary bypass.” J Clin Monit Comput 17, no. 5 (July 2002): 287–92. https://doi.org/10.1023/a:1021298103264.
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    • Vote, D. A., O. Doar, R. E. Moon, and J. G. Toffaletti. “Blood glucose meter performance under hyperbaric oxygen conditions.” Clin Chim Acta 305, no. 1–2 (March 2001): 81–87. https://doi.org/10.1016/s0009-8981(00)00418-6.
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    • Toffaletti, J. G., and R. F. Wildermann. “The effects of heparin anticoagulants and fill volume in blood gas syringes on ionized calcium and magnesium measurements.” Clin Chim Acta 304, no. 1–2 (February 2001): 147–51. https://doi.org/10.1016/s0009-8981(00)00412-5.
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    • Vote, D. A., P. O. Doar, R. E. Moon, and J. G. Toffaletti. “Measurement of plasma glucose under hyperbaric oxygen conditions.” South Pacific Underwater Medicine Society Journal 30, no. 4 (December 1, 2000): 182–86.
    • Toffaletti, J. “Wireless POCT data transmission.” Mlo: Medical Laboratory Observer 32, no. 6 (January 1, 2000).
    • Toffaletti, J. G., and R. F. Wildermann. “Use of turbidity-correction algorithm eliminates the effect of perflubron emulsion on CO-oximeter results.” Clin Chem 46, no. 1 (January 2000): 136–37.
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    • Toffaletti, J. “Blood gas testing in the laboratory and at the point of care. Finding the right mix.” Mlo: Medical Laboratory Observer Suppl (January 1, 1997).
    • Astles, J. R., D. Lubarsky, B. Loun, F. A. Sedor, and J. G. Toffaletti. “Pneumatic transport exacerbates interference of room air contamination in blood gas samples.” Arch Pathol Lab Med 120, no. 7 (July 1996): 642–47.
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    • Astles, J. R., F. A. Sedor, and J. G. Toffaletti. “Evaluation of the YSI 2300 glucose analyzer: algorithm-corrected results are accurate and specific.” Clin Biochem 29, no. 1 (February 1996): 27–31. https://doi.org/10.1016/0009-9120(95)02010-1.
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    • Toffaletti, J. “Elevations in blood lactate: overview of use in critical care.” Scand J Clin Lab Invest Suppl 224 (1996): 107–10. https://doi.org/10.3109/00365519609088628.
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    • Toffaletti, J. “Physiology and regulation. Ionized calcium, magnesium and lactate measurements in critical care settings.” Am J Clin Pathol 104, no. 4 Suppl 1 (October 1995): S88–94.
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    • Toffaletti, J., and D. Hansell. “Interpretation of blood lactate measurements in paediatric open-heart surgery and in extracorporeal membrane oxygenation.” Scand J Clin Lab Invest 55, no. 4 (July 1995): 301–7. https://doi.org/10.3109/00365519509104967.
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    • Toffaletti, J., and T. Thompson. “Effects of blended lithium-zinc heparin on ionized calcium and general clinical chemistry tests.” Clin Chem 41, no. 2 (February 1995): 328–29.
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    • Toffaletti, J. “Use of novel preparations of heparin to eliminate interference in ionized calcium measurements: have all the problems been solved?” Clin Chem 40, no. 4 (April 1994): 508–9.
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    • Paschen, K., P. Hagemann, H. R. Lang, M. Cortes, G. Weidemann, J. Toffaletti, M. Burritt, R. Leinberger, W. Tritschler, and E. Ramstetter. “Determination of potassium by dry reagent carrier technology: a multicentre evaluation.” Eur J Clin Chem Clin Biochem 31, no. 8 (August 1993): 545–52. https://doi.org/10.1515/cclm.1993.31.8.545.
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    • Toffaletti, J., M. E. Hammes, R. Gray, B. Lineberry, and B. Abrams. “Lactate measured in diluted and undiluted whole blood and plasma: comparison of methods and effect of hematocrit.” Clin Chem 38, no. 12 (December 1992): 2430–34.
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    • Toffaletti, J., P. Ernst, P. Hunt, and B. Abrams. “Dry electrolyte-balanced heparinized syringes evaluated for determining ionized calcium and other electrolytes in whole blood.” Clin Chem 37, no. 10 Pt 1 (October 1991): 1730–33.
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    • Toffaletti, J., D. L. Cooper, and B. Lobaugh. “The response of parathyroid hormone to specific changes in either ionized calcium, ionized magnesium, or protein-bound calcium in humans.” Metabolism 40, no. 8 (August 1991): 814–18. https://doi.org/10.1016/0026-0495(91)90008-k.
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    • Anderson, D. J., F. Van Lente, F. S. Apple, S. C. Kazmierczak, J. A. Lott, M. K. Gupta, N. McBride, W. E. Katzin, R. E. Scott, and J. Toffaletti. “Clinical chemistry.” Anal Chem 63, no. 12 (June 15, 1991): 165R-270R. https://doi.org/10.1021/ac00012a011.
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    • Toffaletti, J. G. “Blood lactate: biochemistry, laboratory methods, and clinical interpretation.” Crit Rev Clin Lab Sci 28, no. 4 (1991): 253–68. https://doi.org/10.3109/10408369109106865.
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    • Christenson, R. H., P. Clemmensen, E. M. Ohman, J. Toffaletti, L. M. Silverman, P. Grande, R. T. Vollmer, and G. S. Wagner. “Relative increase in creatine kinase MB isoenzyme during reperfusion after myocardial infarction is method dependent.” Clinical Chemistry 36, no. 8 I (January 1, 1990): 1444–49. https://doi.org/10.1093/clinchem/36.8.1444.
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    • Christenson, R. H., E. M. Ohman, P. Clemmensen, P. Grande, J. Toffaletti, L. M. Silverman, R. T. Vollmer, and G. S. Wagner. “Characteristics of creatine kinase-MB and MB isoforms in serum after reperfusion in acute myocardial infarction.” Clin Chem 35, no. 11 (November 1989): 2179–85.
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    • Toffaletti, J., and B. Abrams. “Effects of in vivo and in vitro production of lactic acid on ionized, protein-bound, and complex-bound calcium in blood.” Clin Chem 35, no. 6 (June 1989): 935–38.
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    • Bode, A. P., D. T. Miller, and J. Toffaletti. “Plasma levels of ionized and total calcium during storage of citrated platelet concentrate.” Transfusion 29, no. 6 (1989): 534–38.
    • Toffaletti, J., B. Abrams, C. Bird, and M. Schwing. “Clinical validation of an automated thin-film reflectance method for measurement of magnesium in serum and urine.” Magnesium 7, no. 2 (1988): 84–90.
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    • Toffaletti, J., R. H. Christenson, S. Mullins, and R. E. Harris. “Relationship between serum lactate and ionized calcium in open-heart surgery.” Clin Chem 32, no. 10 (October 1986): 1849–53.
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    • Toffaletti, J., C. Bird, C. Berg, and B. Abrams. “Aqueous and serum-based materials compared for use as simulated calibrators for three ionized calcium analyzers.” Clin Chem 32, no. 8 (August 1986): 1548–50.
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    • Toffaletti, J. “Chemistry analyzers for the physician's office.” Pathologist 40, no. 5 (January 1, 1986): 25–33.
    • Toffaletti, J., and K. M. Lee. “Preparation and use of serum-based material as control and calibrator in evaluating ion-selective electrodes for calcium.” Clin Chem 31, no. 8 (August 1985): 1349–52.
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    • Toffaletti, J., R. Nissenson, D. Endres, E. McGarry, and G. Mogollon. “Influence of continuous infusion of citrate on responses of immunoreactive parathyroid hormone, calcium and magnesium components, and other electrolytes in normal adults during plateletapheresis.” J Clin Endocrinol Metab 60, no. 5 (May 1985): 874–79. https://doi.org/10.1210/jcem-60-5-874.
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    • Toffaletti, J. “Analytical aspects and clinical applications of ionized calcium measurements.” Health Care Instrumentation 1, no. 2 (January 1, 1985): 66–73.
    • Toffaletti, J. “Automated dry-film method for phosphorus in serum evaluated.” Clin Chem 31, no. 1 (January 1985): 148–49.
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    • Toffaletti, J., N. Blosser, and K. Kirvan. “Effects of storage temperature and time before centrifugation on ionized calcium in blood collected in plain vacutainer tubes and silicone-separator (SST) tubes.” Clin Chem 30, no. 4 (April 1984): 553–56.
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    • Toffaletti, J. “Changes in protein-bound, complex-bound, and ionized calcium related to parathyroid hormone levels in healthy donors during plateletapheresis.” Transfusion 23, no. 6 (November 1983): 471–75. https://doi.org/10.1046/j.1537-2995.1983.23684074265.x.
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    • Toffaletti, J. “Total, ultrafiltrable, dialysable and ionised calcium measurements in randomly selected samples compared with clinical diagnoses.” Ann Clin Biochem 20 (Pt 6) (November 1983): 349–52. https://doi.org/10.1177/000456328302000604.
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    • Toffaletti, J., N. Blosser, T. Hall, S. Smith, and D. Tompkins. “An automated dry-slide enzymatic method evaluated for measurement of creatinine in serum.” Clin Chem 29, no. 4 (April 1983): 684–87.
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    • Toffaletti, J., and J. Hemker. “Dialyzable calcium measured in 60 micro L of routinely processed serum by continuous-flow analysis with CO2/air segmentation.” Clin Chem 28, no. 8 (August 1982): 1815–16.
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    • Toffaletti, J., C. Holleman, and J. Bournique. “Interference in the Dow phosphorus procedure eliminated by ultrafiltration of icteric and hemolyzed samples with the Worthington Ultrafree Calcium Filter.” Clin Chem 28, no. 3 (March 1982): 560.
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    • Tompkins, D., and J. Toffaletti. “Enzymic determination of citrate in serum and urine, with use of the Worthington "ultrafree" device.” Clin Chem 28, no. 1 (January 1982): 192–95.
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    • Toffaletti, J., D. Tompkins, and G. Hoff. “The Worthington "ultrafree" device evaluated for determination of ultrafiltrable calcium in serum.” Clin Chem 27, no. 3 (March 1981): 466–68.
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    • Toffaletti, J., and K. Kirvan. “Spectrophotometric micro method for measurement of dialyzable calcium by use of cresolphthalein complexone and continuous-flow analysis.” Clin Chem 26, no. 11 (October 1980): 1562–65.
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    • Toffaletti, J., and G. N. Bowers. “Improvements in and clinical utility of a continuous-flow method for routine measurement of dialyzable (ultrafiltrable) calcium.” Clin Chem 25, no. 11 (November 1979): 1939–43.
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    • Toffaletti, J., R. B. McComb, and G. N. Bowers. “Increase in dialyzable calcium associated with therapy with lithium.” Clin Chem 25, no. 10 (October 1979): 1806–9.
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    • Toffaletti, J., and G. N. Bowers. “The possible physiologic importance of calcium complexes: an opinion.” Clin Chim Acta 97, no. 2–3 (October 1, 1979): 101–5. https://doi.org/10.1016/0009-8981(79)90406-6.
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    • Toffaletti, J., R. B. McComb, and G. N. Bowers. “Higher incidence of hypercalcemia in patients receiving lithium therapy as determined by measurements of dialyzable and total calcium in serum.” Clinical Chemistry 25, no. 6 (January 1, 1979).
    • Toffaletti, J., J. Savory, and H. J. Gitelman. “Use of gel filtration to examine the distribution of calcium among serum proteins.” Clin Chem 23, no. 12 (December 1977): 2306–10.
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    • Toffaletti, J., J. Savory, and H. J. Gitelman. “Continuous-flow determination of dialyzable calcium in serum.” Clin Chem 23, no. 7 (July 1977): 1258–63.
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    • Toffaletti, J., H. J. Gitelman, and J. Savory. “Separation and quantitation of serum constituents associated with calcium by gel filtration.” Clin Chem 22, no. 12 (December 1976): 1968–72.
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    • Toffaletti, J., and J. Savory. “An overview of the laboratory diagnosis of lead poisoning.” Ann Clin Lab Sci 6, no. 6 (November 1976): 529–36.
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    • Peron, L. C., and J. G. Toffaletti. “Concentration of lead in various endodontic filling materials.” J Endod 2, no. 1 (January 1976): 21–24. https://doi.org/10.1016/S0099-2399(76)80027-1.
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    • Toffaletti, J., and J. Savory. “Use of sodium borohydride for determination of total mercury in urine by atomic absorption spectrometry.” Anal Chem 47, no. 13 (November 1975): 2091–95. https://doi.org/10.1021/ac60363a001.
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