Browsing by Author "Levine, Michael"

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    Acute Methylenedioxypyrovalerone Toxicity
    (Springer-Verlag, 2015-06) Froberg, Blake A.; Levine, Michael; Beuhler, Michael C.; Judge, Bryan S.; Moore, Philip W.; Engebretsen, Kristin M.; Mckeown, Nathanael J.; Rosenbaum, Christopher D.; Young, Amy C.; Rusyniak, Daniel E.; ACMT Toxicology Investigators Consortium (ToxIC); Department of Pediatrics, IU School of Medicine
    The objective of this study was to characterize the acute clinical effects, laboratory findings, complications, and disposition of patients presenting to the hospital after abusing synthetic cathinone. We conducted a retrospective multicenter case series of patients with synthetic cathinone abuse by searching for the terms bath salts, MDPV, methylenedioxypyrovalerone, mephedrone, methcathinone, methylone, methedrone, and cathinone within the "agent" field of a national clinical toxicology database (ToxIC). The medical records of these patients were obtained and abstracted by investigators at each study site. Patients with confirmatory testing that identified a synthetic cathinone in either blood or urine were included in the series. Patients who had either an undetectable synthetic cathinone test or no confirmatory testing were excluded. A data abstraction sheet was used to obtain information on each patient. We entered data into an Excel spreadsheet and calculated descriptive statistics. We identified 23 patients with confirmed synthetic cathinone exposure--all were positive for methylenedioxyprovalerone (MDPV). Eighty-three percent were male and 74 % had recreational intent. The most common reported clinical effects were tachycardia (74 %), agitation (65 %), and sympathomimetic syndrome (65 %). Acidosis was the most common laboratory abnormality (43 %). Seventy-eight percent of patients were treated with benzodiazepines and 30 % were intubated. Ninety-six percent of patients were hospitalized and 87 % were admitted to the ICU. The majority (61 %) of patients was discharged home but 30 % required inpatient psychiatric care. There was one death in our series. The majority of patients presenting to the hospital after abusing MDPV have severe sympathomimetic findings requiring hospitalization. A number of these patients require inpatient psychiatric care after their acute presentation.
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    An MM algorithm for estimation of a two component semiparametric density mixture with a known component
    (IMS, 2018) Shen, Zhou; Levine, Michael; Shang, Zuofeng; Mathematical Sciences, School of Science
    We consider a semiparametric mixture of two univariate density functions where one of them is known while the weight and the other function are unknown. We do not assume any additional structure on the unknown density function. For this mixture model, we derive a new sufficient identifiability condition and pinpoint a specific class of distributions describing the unknown component for which this condition is mostly satisfied. We also suggest a novel approach to estimation of this model that is based on an idea of applying a maximum smoothed likelihood to what would otherwise have been an ill-posed problem. We introduce an iterative MM (Majorization-Minimization) algorithm that estimates all of the model parameters. We establish that the algorithm possesses a descent property with respect to a log-likelihood objective functional and prove that the algorithm, indeed, converges. Finally, we also illustrate the performance of our algorithm in a simulation study and apply it to a real dataset.
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    OR30-1 Safety and Efficacy of Recombinant Human Parathyroid Hormone 1-84 for the Treatment of Adults with Chronic Hypoparathyroidism: Six-Year Results of the RACE Study
    (Oxford University Press, 2019-04-15) Bilezikian, John; Bone, Henry; Clarke, Bart; Denham, Douglas; Lee, Hak-Myung; Levine, Michael; Mannstadt, Michael; Peacock, Munro; Rothman, Jeffrey; Sherry, Nicole; Shoback, Dolores; Vokes, Tamara; Warren, Mark; Watts, Nelson; Medicine, School of Medicine
    RACE is an open-label study that assessed the long-term safety and efficacy of recombinant human parathyroid hormone 1-84 (rhPTH[1-84]) for the treatment of hypoparathyroidism in adults (ClinicalTrials.gov identifier NCT01297309). Patients initially received 25 or 50 µg/day of rhPTH(1-84) subcutaneously, once daily, with stepwise dose adjustments of 25 µg (up or down) to a maximum of 100 µg/day. rhPTH(1-84) could be titrated and oral calcium (Ca) and calcitriol doses adjusted at any time during the study to maintain albumin-corrected serum Ca levels in the target range of 8.0-9.0 mg/dL. A composite efficacy endpoint was the proportion of patients who achieved at least a 50% reduction from baseline (BL) in oral Ca dose (or Ca ≤500 mg/day) and at least a 50% reduction from BL in calcitriol dose (or calcitriol ≤0.25 µg/day), while normalizing or maintaining albumin-corrected serum Ca compared with BL value and not exceeding the upper limit of normal for the central laboratory. Here, we present 6-year safety and efficacy data with descriptive summary statistics (mean ± SD). The study cohort consisted of 49 patients enrolled at 12 US centers (mean age, 48.1±9.78 years; 81.6% female); data from 34 patients (69.4%) who completed 72 months (M72) of treatment with rhPTH(1-84) as of July 17, 2018 are presented here. Oral Ca and calcitriol doses were reduced by 40.4% and 72.2% at M72, respectively, and albumin-corrected serum Ca levels were maintained within the target range (BL, 8.4±0.70 mg/dL; M72, 8.4±0.68 mg/dL). At M72, 22 of 34 patients (64.7%) achieved the composite efficacy endpoint. Urinary Ca excretion declined from above-normal at BL to within the normal range (BL, 356.7±200.37 mg/24 h; M72, 213.2±128.82 mg/24 h). Mean serum creatinine levels remained stable (BL, 1.0±0.21 mg/dL; M72, 0.9±0.21 mg/dL), as did estimated glomerular filtration rate (eGFR; BL, 77.7±17.67 mL/min/1.73 m2; M72, 79.4±18.39 mL/min/1.73 m2). Serum phosphorus levels declined from above-normal at BL to within normal range (BL, 4.8±0.58 mg/dL; M72, 4.0±0.62 mg/dL); calcium-phosphorus product levels also declined (BL, 42.1±6.35 mg2/dL2; M72, 33.7±5.01 mg2/dL2). Treatment-emergent adverse events and treatment-emergent serious adverse events were reported in 98.0% and 26.5% of patients, respectively; no new safety concerns were identified. Continuous use of rhPTH(1-84) over 6 years resulted in a favorable safety profile, was effective, and improved key measurements of mineral homeostasis, notably normalization of urinary calcium. Disclosures: All of the authors disclose a relationship with Shire: advisory board member, JPB, MAL, MM, DMS, TJV; consultant, JPB, BLC, MAL, MM, DMS, TJV; grant recipient, JPB, DD, MM, MP, DMS, MLW; employee, H-ML, NS; research investigator, JPB, HB, JR, DMS, TJV, MLW, NBW; speaker, JPB, HB, MLW, NBW. Funding: Shire