Association of tacrolimus time-to-therapeutic range on renal dysfunction and acute cellular rejection after orthotopic heart transplantation in a high use basiliximab population.

BACKGROUND: Currently, clinicians often delay initiation of tacrolimus after orthotopic heart transplantation (OHT) to help mitigate nephrotoxicity. This study aimed to determine if there is an association between the time-to-therapeutic range (TTT) of tacrolimus, early renal dysfunction, and acute cellular rejection (ACR) after OHT. METHODS: This was a retrospective, single center study with adult patients who underwent OHT from July 2013 to April 2020. Logistic regression analysis was utilized to examine the association of TTT with new renal dysfunction after tacrolimus initiation post-OHT. RESULTS: In a study of 317 patients, the unadjusted analysis showed patients who developed new renal dysfunction after tacrolimus initiation had a numerically shorter TTT (9.5 vs. 11.0 days, P = .065), and were more likely to have supratherapeutic tacrolimus levels (56% vs. 39.2%, P = .010). When adjusted for established risk factors for renal dysfunction, TTT was significantly associated with new renal dysfunction (OR .95; 95% CI [.90, .99], P = .03). There was no association between TTT and the incidence of ACR (11.1 vs. 10.8 days, P = .64). CONCLUSION: When adjusting for known risk factors, a shorter TTT was associated with new renal dysfunction. Supratherapeutic tacrolimus levels were also associated with new renal dysfunction. There was no association between TTT and ACR in the setting of high use basiliximab induction.

Characterization of 252Cf sources using high-resolution gamma spectroscopy.

Californium-252 is used as a neutron calibration source for passive neutron correlation counting. Source age and isotopic information are needed to make decay corrections to the neutron emission rate due to the influence of 250Cf. Gamma-ray signatures present in the spectrum from spontaneous fission products and odd-numbered Cf isotopes can be used with high accuracy to confirm or query declared values on a technical data sheet. This method is good practice for independently verifying the content of 252Cf calibration sources.

Evaluation of Shiryaev-Roberts procedure for on-line environmental radiation monitoring.

Water can become contaminated as a result of a leak from a nuclear facility, such as a waste facility, or from clandestine nuclear activity. Low-level on-line radiation monitoring is needed to detect these events in real time. A Bayesian control chart method, Shiryaev-Roberts (SR) procedure, was compared with classical methods, 3-σ and cumulative sum (CUSUM), for quantifying an accumulating signal from an extractive scintillating resin flow-cell detection system. Solutions containing 0.10-5.0 Bq/L of 99Tc, as T99cO4- were pumped through a flow cell packed with extractive scintillating resin used in conjunction with a Beta-RAM Model 5 HPLC detector. While T99cO4- accumulated on the resin, time series data were collected. Control chart methods were applied to the data using statistical algorithms developed in MATLAB. SR charts were constructed using Poisson (Poisson SR) and Gaussian (Gaussian SR) probability distributions of count data to estimate the likelihood ratio. Poisson and Gaussian SR charts required less volume of radioactive solution at a fixed concentration to exceed the control limit in most cases than 3-σ and CUSUM control charts, particularly solutions with lower activity. SR is thus the ideal control chart for low-level on-line radiation monitoring. Once the control limit was exceeded, activity concentrations were estimated from the SR control chart using the control chart slope on a semi-logarithmic plot. A linear regression fit was applied to averaged slope data for five activity concentration groupings for Poisson and Gaussian SR control charts. A correlation coefficient (R2) of 0.77 for Poisson SR and 0.90 for Gaussian SR suggest this method will adequately estimate activity concentration for an unknown solution.

Positive Impact of Continuous-Flow Left Ventricular Assist Device Implantation on Glycemic Control in Patients with Type 2 Diabetes Mellitus and Advanced Chronic Systolic Heart Failure.

STUDY OBJECTIVE: To evaluate the impact of continuous-flow left ventricular assist device (LVAD) implantation on glycemic control in patients with type 2 diabetes mellitus and advanced chronic systolic heart failure. DESIGN: Retrospective medical record review. SETTING: Large academic tertiary and quaternary care hospital. PATIENTS: Eighty-three adults with type 2 diabetes mellitus and advanced chronic systolic heart failure who underwent implantation of a continuous-flow LVAD between July 1, 2008, and June 30, 2013. MEASUREMENTS AND MAIN RESULTS: Baseline demographic data and laboratory values pertinent to glycemic control (hemoglobin A1c [A1C], total daily insulin requirements, noninsulin antidiabetic medication use, and body mass index [BMI]) were collected for each patient. Pre-LVAD data were compared with data obtained during the 24 months after LVAD implantation. The mean age of the study population was 61.3 years, 70% were men, and 63% had ischemic cardiomyopathy. The first available mean ± SD A1C after LVAD implantation was 6.21 ± 1.5% at a median of 4.8 months (interquartile range 3.3-8.9), which represented a significant decrease from the pre-LVAD A1C of 7.46 ± 1.5% (p<0.001). Average daily insulin requirements decreased by 22.9 units at the end of 24 months (p<0.001). Over half of patients with prescriptions for noninsulin antidiabetic medications were able to discontinue therapy by the end of the study. Of note, BMI increased in the second year after LVAD implantation from a baseline of 32.3 kg/m2 to 34.9 kg/m2 (p=0.004). Regression analysis revealed that baseline A1C was the only independent predictor of change in A1C. CONCLUSION: LVAD implantation was associated with a significant improvement in glycemic control. Further prospective studies are needed to evaluate the long-term impact of LVAD implantation on the clinical course of diabetes.