A Federated Learning and Deep Reinforcement Learning-Based Method with Two Types of Agents for Computation Offload.

With the rise of latency-sensitive and computationally intensive applications in mobile edge computing (MEC) environments, the computation offloading strategy has been widely studied to meet the low-latency demands of these applications. However, the uncertainty of various tasks and the time-varying conditions of wireless networks make it difficult for mobile devices to make efficient decisions. The existing methods also face the problems of long-delay decisions and user data privacy disclosures. In this paper, we present the FDRT, a federated learning and deep reinforcement learning-based method with two types of agents for computation offload, to minimize the system latency. FDRT uses a multi-agent collaborative computation offloading strategy, namely, DRT. DRT divides the offloading decision into whether to compute tasks locally and whether to offload tasks to MEC servers. The designed DDQN agent considers the task information, its own resources, and the network status conditions of mobile devices, and the designed D3QN agent considers these conditions of all MEC servers in the collaborative cloud-side end MEC system; both jointly learn the optimal decision. FDRT also applies federated learning to reduce communication overhead and optimize the model training of DRT by designing a new parameter aggregation method, while protecting user data privacy. The simulation results showed that DRT effectively reduced the average task execution delay by up to 50% compared with several baselines and state-of-the-art offloading strategies. FRDT also accelerates the convergence rate of multi-agent training and reduces the training time of DRT by 61.7%.

Pharmacokinetic Drug-Drug Interaction Study of Omecamtiv Mecarbil With Omeprazole, a Proton Pump Inhibitor, in Healthy Subjects.

Omecamtiv mecarbil (OM) is a novel cardiac myosin activator in development for the treatment of heart failure (HF) with reduced ejection fraction. OM is administered as a 25-, 37.5-, or 50-mg modified-release formulation in patients with HF. Proton pump inhibitors are one of the most commonly prescribed drugs in this patient population. Given the potential for coadministration of both drugs in patients with HF, we evaluated the potential for omeprazole to affect the pharmacokinetics of OM in an open-label study in 14 healthy subjects. Subjects received a single 50-mg dose of OM on day 1, followed by 40-mg once-daily doses of omeprazole on days 4 to 8. On day 9, a single 40-mg dose of omeprazole was administered first and immediately followed by 50-mg of OM. Blood samples were collected up to 144 hours after dosing following administration of OM on days 1 and 9 to characterize plasma concentrations of OM. The ratios of the geometric least-square means (90% confidence intervals) of OM coadministered with omeprazole compared to OM alone were 94.5% (81.7%-109.3%), 94.3% (81.5%-109.1%), and 101.2% (95.4%-107.3%) for area under the plasma concentration-time curve from time 0 to infinity, area under the plasma concentration-time curve from time 0 to the last measurable concentration, and maximum observed plasma concentration, respectively. Coadministration of OM with omeprazole was not associated with any clinically significant pharmacokinetic drug interactions. Single doses of OM were safe and well tolerated when coadministered with omeprazole.

Pharmacokinetic Drug-Drug Interaction Study of Omecamtiv Mecarbil With Amiodarone and Digoxin in Healthy Subjects.

Omecamtiv mecarbil (OM), a novel cardiac myosin activator, is being evaluated for the treatment of heart failure with reduced ejection fraction. In vitro studies demonstrate OM as a substrate and inhibitor of P-glycoprotein (P-gp), which can result in drug-drug interactions. Two phase 1, open-label studies assessed the effect of coadministration of OM (50-mg single dose) on the pharmacokinetics of digoxin (0.5-mg single dose; N = 15), a P-gp substrate, and the effect of coadministration of amiodarone (600-mg single dose), a P-gp inhibitor, on the pharmacokinetics of OM (50-mg single dose; N = 14) in healthy subjects. The ratios of the geometric least squares mean (90% confidence interval [CI]) of digoxin coadministered with OM vs digoxin alone for area under the plasma concentration-time curve (AUC) from time 0 to infinity, AUC from time 0 to the time of the last quantifiable concentration, and maximum observed plasma concentration were 1.06 (90%CI, 0.99-1.14), 1.06 (90%CI, 0.98-1.14), and 1.08 (90%CI, 0.92-1.26), respectively. The ratios of the geometric least squares mean of OM coadministered with amiodarone vs OM alone for AUC from time 0 to infinity, AUC from time 0 to the time of the last quantifiable concentration, and maximum observed plasma concentration were 1.21 (90%CI, 1.08-1.36), 1.21 (90%CI, 1.07-1.36), and 1.08 (90%CI, 0.96-1.22), respectively. In conclusion, OM coadministered with digoxin or amiodarone did not result in any clinically relevant pharmacokinetic drug-drug interactions.

Pharmacokinetic Evaluation of the CYP3A4 and CYP2D6 Drug-Drug Interaction and CYP3A4 Induction Potential of Omecamtiv Mecarbil: Two Open-Label Studies in Healthy Subjects.

Omecamtiv mecarbil (OM) is a cardiac myosin activator under development for the treatment of heart failure. The effect of CYP3A4 and CYP2D6 inhibition on OM pharmacokinetics and the potential for OM to induce CYP3A4 was assessed in 2 studies. Study 1, part A, assessed the effect of ketoconazole 200 mg on the pharmacokinetics of OM 10 mg in CYP2D6 extensive metabolizers (EMs; n = 8) or poor metabolizers (PMs; n = 8). Study 1, part B, assessed the effect of diltiazem 240 mg on the pharmacokinetics of OM 10 mg (EM; n = 8). Study 2 assessed the effect of OM 25 mg on the pharmacokinetics of midazolam 5 mg (n = 14). Coadministration with ketoconazole led to 51% and 31% increases in OM AUCinf in EM and PM subjects, respectively, whereas OM Cmax remained similar (3% higher and 14% lower for EM and PM subjects, respectively). No changes in OM pharmacokinetics were observed in EM subjects following coadministration with diltiazem. Midazolam AUCinf and Cmax decreased by 18% and 10%, respectively, when coadministered with OM. In conclusion, CYP3A4 and CYP2D6 inhibitors are unlikely to have a clinically significant effect on the pharmacokinetics of OM. In addition, OM is unlikely to have a clinically relevant effect on the pharmacokinetics of CYP3A4 substrates.

Omecamtiv mecarbil does not prolong QTc intervals at therapeutic concentrations.

AIMS: Omecamtiv mecarbil (OM) is a novel selective cardiac myosin activator under investigation for the treatment of heart failure. This study aimed to evaluate the effect of therapeutic concentrations of OM on electrocardiogram (ECG) parameters and exclude a clinically concerning effect on the rate-corrected QT (QTc) interval. METHODS: In part A, 70 healthy subjects received a 25 mg oral dose of OM, and pharmacokinetics were assessed. Only subjects with maximum observed plasma concentration ≤ 350 ng/mL (n = 60) were randomized into part B, where they received a single oral dose of placebo, 50 mg OM and 400 mg moxifloxacin in a 3-period, 3-treatment, 6-sequence crossover study with continuous ECG collection. RESULTS: After a 50-mg dose of OM, mean placebo-corrected change from baseline QTcF (∆∆QTcF; Fridericia correction) ranged from -6.7 ms at 1 hour postdose to -0.8 ms at 4 hours postdose. The highest upper bound of the 1-sided 95% confidence interval (CI) was 0.7 ms (4 h postdose). Moxifloxacin resulted in a clear increase in mean ∆∆QTcF, with a peak value of 13.1 ms (90% CI: 11.71-14.57) at 3 hours; lower bound of the 1-sided 95% CI was > 5 ms at all of the 3 prespecified time points. Based on a concentration-QTc analysis, an effect on ∆∆QTcF exceeding 10 ms can be excluded up to OM plasma concentrations of ~800 ng/mL. There were no serious or treatment-emergent adverse events leading to discontinuation from the study. CONCLUSION: OM does not have a clinically relevant effect on the studied ECG parameters.

Evaluation of drug-drug interaction potential between omecamtiv mecarbil and rosuvastatin, a BCRP substrate, with a clinical study in healthy subjects and using a physiologically-based pharmacokinetic model.

Omecamtiv mecarbil (OM) is a novel cardiac myosin activator in development for the treatment of heart failure. In vitro, OM is an inhibitor of BCRP. Rosuvastatin, a BCRP substrate, is one of the most commonly prescribed medications in patients with heart failure. The potential for a pharmacokinetic (PK) drug-drug interaction (DDI) was investigated, specifically to determine whether a single 50 mg dose of OM would impact the PKs of a single 10 mg dose of rosuvastatin in an open-label study in 14 healthy subjects. The ratios of the geometric least-square means (90% confidence intervals [CIs]) of rosuvastatin co-administered with OM compared to rosuvastatin alone were 127.1% (90% CI 113.8-141.9), 132.8% (90% CI 120.7-146.1), and 154.2% (90% CI 132.8-179.1) for area under the plasma-concentration time curve from time zero to infinity (AUCinf ), area under the plasma-concentration time curve from time zero to time of last quantifiable concentration (AUClast ), and maximum observed plasma concentration (Cmax ), respectively. Whereas the DDI study with rosuvastatin was conducted with the co-administration of a single dose of OM, in the clinical setting, patients receive OM at doses of 25, 37.5, or 50 mg twice daily (b.i.d.). Hence, to extrapolate the results of the DDI study to a clinically relevant scenario of continuous b.i.d. dosing with OM, physiologically-based pharmacokinetic (PBPK) modeling was performed to explore the potential of BCRP inhibition following continuous b.i.d. dosing of OM at the highest 50 mg dose. Modeling results indicated that following 50 mg b.i.d. dosing of OM, the predicted ratios of the geometric means (90% CIs) for rosuvastatin AUCinf and Cmax were 1.18 (90% CI 1.16-1.20) and 2.04 (90% CI 1.99-2.10), respectively. Therefore, these results suggest that OM, following multiple dose administration, is a weak inhibitor of BCRP substrates and is in accordance with that observed in the single dose OM DDI clinical study.

Effect of Omecamtiv Mecarbil on the Pharmacokinetics of Metformin, a Probe Substrate for MATE1/MATE2-K, in Healthy Subjects.

BACKGROUND AND OBJECTIVE: Omecamtiv mecarbil (OM) is a novel cardiac myosin activator in development for the treatment of heart failure with reduced ejection fraction. The objective of this study was to evaluate the potential for OM to affect the pharmacokinetics of metformin. METHODS: This was an open-label, fixed-sequence study in 14 healthy subjects. On Day 1, subjects received an 850 mg oral dose of metformin. From Days 4 to 9, subjects received twice-daily 25 mg oral doses of OM tablets. On Day 10, subjects received an 850 mg oral dose of metformin and a single 25 mg tablet of OM. Blood and urine samples were collected up to 36 h post-dose following administration of metformin on Days 1 and 10 to characterize concentrations of metformin in plasma and urine. RESULTS: The ratios of the geometric least square means of metformin coadministered with OM compared to metformin alone were 98.7%, 99.3%, and 110.2% for AUCinf, AUClast, and Cmax, respectively. The mean renal clearance of metformin was similar following metformin administered alone (34.2 L/h) compared to metformin coadministered with OM (32.9 L/h). All adverse events were mild in severity and resolved prior to the end of the study. No serious adverse events or treatment-emergent adverse events led to discontinuation from the study. CONCLUSIONS: There was no clinically relevant effect of OM on the pharmacokinetics of metformin in healthy subjects.

Switchability and minimal effect of food on pharmacokinetics of modified release tablet strengths of omecamtiv mecarbil, a cardiac myosin activator.

Omecamtiv mecarbil (OM) is a cardiac myosin activator in clinical development for the treatment of heart failure. The effect of food on the pharmacokinetics (PK) of 25, 37.5, and 50 mg strength modified release (MR) tablets and the bioequivalence of two 25 mg tablets versus one 50 mg MR tablet were evaluated in two open-label, randomized, cross-over studies in healthy subjects. Subjects received two 25 mg tablets or one 50 mg OM MR tablet under fed or fasted states in Study 1 (n = 39), and single oral doses of 25 and 37.5 mg OM MR tablets and to assess its relative bioavailability to the 25 mg MR tablet, a 25 mg oral solution under fed or fasted states in Study 2 (n = 34). The area under the concentration-time curve (AUC) and the maximum observed concentration (Cmax ) of 25, 37.5, or 50 mg OM MR tablets were approximately 13%-22% higher and 31%-40% higher, respectively, when taken with food. The two 25 mg and one 50 mg OM MR tablets were bioequivalent (90% confidence intervals) of the geometric mean ratios for Cmax and AUC of OM were within 0.8-1.25 under the fasted or fed state. OM was well tolerated and all treatment-emergent events were mild in severity and resolved by the end of the study. In conclusion, these studies demonstrated that the effect of food on the PK of OM was minimal at all three studied strengths of the MR tablets, and two 25 mg MR tablets may be switched for one 50 mg MR tablet (EudraCT Number: 2019-003683-44).

Effect of Varying Degrees of Hepatic Impairment on the Pharmacokinetics of Omecamtiv Mecarbil.

Omecamtiv mecarbil (OM) is a novel selective cardiac myosin activator under investigation for the treatment of heart failure with reduced ejection fraction. OM is primarily eliminated via metabolism mediated by multiple cytochrome P450 enzymes. This phase 1 single-dose, multicenter, open-label, nonrandomized study evaluated the pharmacokinetics (PK) of OM and major metabolites M3 and M4, safety, and tolerability following oral administration of a single dose of 25-mg MR tablet in subjects with mild (n = 6) or moderate (n = 6) hepatic impairment (according to Child-Pugh classification) versus subjects with normal hepatic function (n = 6). Relative to subjects with normal hepatic function, for subjects with mild or moderate hepatic impairment, OM AUCinf was 103.2% (90%CI, 58.0%-183.6%) and 94.8% (90%CI, 54.7%-164.1%), respectively, and OM Cmax was 126.8% (90%CI, 85.7%-187.7%) and 117.3% (90%CI, 80.7%-170.5%), respectively. Exposures to M3 were similar across groups, whereas slightly lower exposures were observed for M4 with worsening hepatic function. The OM, M3, and M4 tmax and t1/2 values were similar between groups. There were no serious adverse events (AEs) or treatment-related treatment-emergent AEs. Overall, OM, M3, and M4 PK were not meaningfully affected by mild or moderate hepatic impairment, suggesting the same dosing strategy can be used in subjects with mild or moderate hepatic impairment.

Relative Bioavailability of Omecamtiv Mecarbil Pediatric Minitablet Formulations in Healthy Adult Subjects.

BACKGROUND AND OBJECTIVE: Omecamtiv mecarbil (OM) is a cardiac myosin activator under clinical development for the treatment of heart failure. Two modified-release (MR) novel OM minitablet formulations were developed to support the planned investigation of chronic heart failure in pediatric patients. The primary objective of this study was to determine the bioavailability of the minitablets relative to the adult matrix MR formulation tablets. METHODS: In a randomized, 5-period, crossover study, 20 healthy subjects received each of the following treatments orally: one 25-mg adult matrix MR tablet, 25 1-mg slow-release minitablets, 25 1-mg fast-release minitablets, six 1-mg slow-release minitablets, or six 1-mg fast-release minitablets after an overnight fast of at least 10 h with a minimum washout of 7 days between treatments. Blood samples were collected for up to 168 h. OM pharmacokinetic parameters were estimated using non-compartmental methods. RESULTS: When OM was administered as 25 1-mg OM slow-release minitablets, AUClast, AUCinf, and Cmax were 0.998-, 1.00-, and 1.29-fold of a single 25-mg OM matrix MR tablet, respectively. When OM was administered as 25 1-mg OM fast-release minitablets, AUClast, AUCinf, and Cmax were 1.26-, 1.25-, and 2.21-fold of a single 25-mg OM matrix MR tablet, respectively. The slow- and fast-release minitablets display approximately dose-proportional pharmacokinetics. There were no serious adverse events or treatment-emergent adverse events leading to discontinuation from the study. CONCLUSIONS: Relative bioavailability of slow-release minitablets was demonstrated to be similar to the adult matrix MR formulation.

Effect of Varying Degrees of Renal Impairment on the Pharmacokinetics of Omecamtiv Mecarbil.

BACKGROUND AND OBJECTIVE: Omecamtiv mecarbil is a novel selective cardiac myosin activator (myotrope) under investigation for the treatment of heart failure with reduced ejection fraction. The objective of this clinical study was to estimate the effect of varying degrees of renal impairment on the pharmacokinetics of omecamtiv mecarbil single dose (50 mg) under fasted conditions. METHODS: This phase I, open-label, non-randomized, parallel-group study evaluated the pharmacokinetics, safety, and tolerability of a single oral dose of omecamtiv mecarbil 50 mg in individuals with normal renal function or mild, moderate, and severe renal impairment, including end-stage renal disease requiring dialysis. Geometric least-squares mean ratios of maximum observed concentration (Cmax) and area under the plasma concentration-time curve (AUC) and 90% confidence intervals were derived for comparisons of renal impairment vs normal renal function. Participants were monitored for adverse events. RESULTS: Thirty-one participants received treatment and completed the study. Geometric mean exposures were similar for participants with renal impairment (AUC∞ range, 2550-3220 h*ng/mL; Cmax range, 78.9-107 ng/mL) and participants with normal renal function (AUC∞, 2790 h*ng/mL; Cmax, 92.6 ng/mL), with geometric least-squares mean ratios of 85.2-125.9. Exposure was similar on dialysis vs non-dialysis days in participants with end-stage renal disease (AUC0-24, 1650 vs 1700 h*ng/mL; Cmax, 100.0 vs 107.0 ng/mL). Four participants (12.9%) reported four treatment-emergent adverse events. No deaths, treatment-emergent adverse events leading to discontinuation, or serious adverse events occurred. CONCLUSIONS: Omecamtiv mecarbil pharmacokinetics were not meaningfully affected by renal function or hemodialysis, suggesting the same dosing strategy can be used in individuals with normal renal function or renal impairment. Oral administration of omecamtiv mecarbil was not associated with major tolerability findings. This study supports omecamtiv mecarbil for the treatment of heart failure in individuals with or without renal impairment.

Bayesian joint modeling for partially linear mixed-effects quantile regression of longitudinal and time-to-event data with limit of detection, covariate measurement errors and skewness.

Joint modeling analysis of longitudinal and time-to-event data has been an active area of statistical methodological study and biomedical research, but the majority of them are based on mean-regression. Quantile regression (QR) can characterize the entire conditional distribution of the outcome variable, and may be more robust to outliers/heavy tails and misspecification of error distribution. Additionally, a parametric specification may be insufficient and inflexible to capture the complicated longitudinal pattern of biomarkers. Thus, this study proposes novel QR-based partially linear mixed-effects joint models with three components (QR-based longitudinal response, longitudinal covariate, and time-to-event processes), and applies to Multicenter AIDS Cohort Study (MACS). Many common data features, including left-censoring due to a limit of detection, covariate measurement error, and asymmetric distribution, are considered to obtain reliable parameter estimates. Many interesting findings are discovered by the complicated joint models under Bayesian inference framework. Simulation studies are also implemented to assess the performance of the proposed joint models under different scenarios.

The neurotoxic effect of isoflurane on age-defined neurons generated from tertiary dentate matrix in mice.

INTRODUCTION: Recent animal studies showed that isoflurane exposure may lead to the disturbance of hippocampal neurogenesis and later cognitive impairment. However, much less is known about the effect of isoflurane exposure on the neurons generated form tertiary dentate matrix, even though a great increase of granule cell population during the infantile period is principally derived from this area. METHODS: To label the new cells originated from the tertiary dentate matrix, the mice were injected with BrdU on postnatal day 6 (P6). Then, the mice were exposed to isoflurane for 4 hr at 1, 8, 21, and 42 days after BrdU injection, and the brains were collected 24 hr later. The loss of newly generated cells/neurons with different developmental stage was assessed by BrdU, BrdU + DCX, BrdU + NeuN, or BrdU + Prox-1 staining, respectively. RESULTS: We found that the isoflurane exposure significantly decreased the numbers of nascent cells (1 day old) and mature neurons (42 days old), but had no effect on the immature (8 days old) and early mature neurons (8 and 21 days old, respectively). CONCLUSION: The results suggested isoflurane exposure exerts the neurotoxic effects on the tertiary dentate matrix-originated cells with an age-defined pattern in mice, which partly explain the cognitive impairment resulting from isoflurane exposure to the young brain.

Effects of Omecamtiv Mecarbil on Symptoms and Health-Related Quality of Life in Patients With Chronic Heart Failure: Results From the COSMIC-HF Study.

BACKGROUND: Chronic heart failure with reduced ejection fraction impairs health-related quality of life (HRQL). Omecamtiv mecarbil (OM)-a novel activator of cardiac myosin-improves left ventricular systolic function and remodeling and reduces natriuretic peptides. We sought to evaluate the effect of OM on symptoms and HRQL in patients with chronic heart failure with reduced ejection fraction and elevated natriuretic peptides enrolled in the COSMIC-HF trial (Chronic Oral Study of Myosin Activation to Increase Contractility in Heart Failure). METHODS: Patients (n=448) were randomized 1:1:1 to placebo, 25 mg of OM BID, or to pharmacokinetically guided dose titration (OM-PK) for 20 weeks. The Kansas City Cardiomyopathy Questionnaire was administered to assess HRQL at baseline, 16 weeks, and 20 weeks. The primary scores of interest were the Total Symptom Score, Physical Limitation Scale, and Clinical Summary Score. RESULTS: Mean change in score from baseline to 20 weeks for the Total Symptom Score was 5.0 (95% CI, 1.8-8.1) for placebo, 6.6 (95% CI, 3.4-9.8) for OM 25 mg (P=0.32 versus placebo), and 9.9 (95% CI, 6.7-13.0) for OM-PK (P=0.03 versus placebo); for the Physical Limitation Scale, it was 3.1 for placebo (95% CI, -0.3 to 6.6), 6.0 (95% CI, 3.1-8.9) for OM 25 mg (P=0.12), and 4.3 (95% CI, 0.7-7.9) for OM-PK (P=0.42); for the Clinical Summary Score, it was 4.1 (95% CI, 1.4-6.9) for placebo, 6.3 (95% CI, 3.6-9.0) for OM 25 mg (P=0.19), and 7.0 (95% CI, 4.1-10.0) for OM-PK (P=0.14). Differences between OM and placebo were greater in patients who were more symptomatic at baseline. CONCLUSIONS: HRQL as measured by the Total Symptom Score improved in patients with heart failure with reduced ejection fraction assigned to the OM-PK group relative to placebo. Ongoing trials are prospectively testing whether OM improves symptoms and HRQL in heart failure with reduced ejection fraction. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01786512.

Quantile regression-based Bayesian joint modeling analysis of longitudinal-survival data, with application to an AIDS cohort study.

In longitudinal studies, it is of interest to investigate how repeatedly measured markers are associated with time to an event. Joint models have received increasing attention on analyzing such complex longitudinal-survival data with multiple data features, but most of them are mean regression-based models. This paper formulates a quantile regression (QR) based joint models in general forms that consider left-censoring due to the limit of detection, covariates with measurement errors and skewness. The joint models consist of three components: (i) QR-based nonlinear mixed-effects Tobit model using asymmetric Laplace distribution for response dynamic process; (ii) nonparametric linear mixed-effects model with skew-normal distribution for mismeasured covariate; and (iii) Cox proportional hazard model for event time. For the purpose of simultaneously estimating model parameters, we propose a Bayesian method to jointly model the three components which are linked through the random effects. We apply the proposed modeling procedure to analyze the Multicenter AIDS Cohort Study data, and assess the performance of the proposed models and method through simulation studies. The findings suggest that our QR-based joint models may provide comprehensive understanding of heterogeneous outcome trajectories at different quantiles, and more reliable and robust results if the data exhibits these features.

Bayesian quantile regression-based partially linear mixed-effects joint models for longitudinal data with multiple features.

In longitudinal AIDS studies, it is of interest to investigate the relationship between HIV viral load and CD4 cell counts, as well as the complicated time effect. Most of common models to analyze such complex longitudinal data are based on mean-regression, which fails to provide efficient estimates due to outliers and/or heavy tails. Quantile regression-based partially linear mixed-effects models, a special case of semiparametric models enjoying benefits of both parametric and nonparametric models, have the flexibility to monitor the viral dynamics nonparametrically and detect the varying CD4 effects parametrically at different quantiles of viral load. Meanwhile, it is critical to consider various data features of repeated measurements, including left-censoring due to a limit of detection, covariate measurement error, and asymmetric distribution. In this research, we first establish a Bayesian joint models that accounts for all these data features simultaneously in the framework of quantile regression-based partially linear mixed-effects models. The proposed models are applied to analyze the Multicenter AIDS Cohort Study (MACS) data. Simulation studies are also conducted to assess the performance of the proposed methods under different scenarios.

Reassessment of different criteria for diagnosing post-hepatectomy liver failure: a single-center study of 1683 hepatectomy.

Assessing the incidence and severity of post-hepatectomy liver failure (PHLF) can be based on different criteria, and we wished to compare the diagnostic efficiency and specificity of different PHLF criteria. Data from patients (n=1683) who received hepatectomies in the liver surgery department of Peking Union Medical College Hospital from April 2008 to August 2014 were retrospectively analyzed. Possible PHLF patients were screened according to the criteria of the International Study Group of Liver Surgery (ISGLS). Subsequently, other PHLF evaluation methods, including Child-Pugh score, "50-50" criteria, Model for End-Stage Liver Disease (MELD) score, and Clavien-Dindo classification were used to assess the suspected PHLF patients, and statistical analysis was performed for correlation of these methods with clinical prognoses. Using ISGLS grading, 40 cases (2.38%) were suspected to have PHLF, among whom 5 (0.30%) patients died. Of the 40 cases there were 9 patients of ISGLS grade A, 21 of grade B, and 10 of grade C. Among the entire group, Child-Pugh scoring showed 3 patients in grade A, 35 in grade B, and 2 in grade C, while only 5 patients met the "50-50" criteria. Interestingly, MELD scores ≥11 points were found only in 3 cases. Twenty-eight patients were classified as Clavien-Dindo grade I, 8 as grade II, 3 as grade III, and 1 as grade IV. Prothrombin time on postoperative day 5 (PT5), ISGLS, and Clavien-Dindo were found to have significant correlation with the prognosis of PHLF (r>0.5, p <0.05), thus can be used as prognosis predictors for PHLF patients.

Outcomes in Adenomyosis Treated with Uterine Artery Embolization Are Associated with Lesion Vascularity: A Long-Term Follow-Up Study of 252 Cases.

PURPOSE: To study the therapeutic effects of uterine artery embolization (UAE) on adenomyosis and to investigate the association between uterine blood supply and artery embolization treatment outcomes. METHODS: Using digital subtraction angiography (DSA) imaging data, we retrospectively evaluated the vascular features of 252 adenomyosis patients treated with UAE. The cases were classified based on the equality of uterine blood supply (equal and unequal subgroups) and the degree of vascularity at the adenomyosis lesion site (hypervascular, isovascular and hypovascular subgroups). Patients were followed-up for 5 years after UAE. Improvements in dysmenorrhea and menorrhagia were evaluated based on the relief of the patients' symptoms. The improvement rates among the different subgroups were analyzed and compared. RESULTS: The improvement rates of dysmenorrhea and menorrhagia were 74.0% and 70.9%, respectively, at the short-term (12-month) follow-up and 70.4% and 68.8%, respectively, at the long-term (5-year) follow-up. No statistically significant differences were observed in the improvement rates for dysmenorrhea or menorrhagia between the equal and unequal blood supply subgroups at either the short- or long-term follow-up. The improvement rates for dysmenorrhea among the hypervascular, isovascular and hypovascular subgroups were 86.5%, 71.8% and 58.8%, respectively, at the short-term follow-up (p = 0.002) and 83.6%, 67.3% and 52.8%, respectively, at the long-term follow-up (p = 0.005). The improvement rates for menorrhagia in the hypervascular, isovascular and hypovascular subgroups were 81.0%, 68.3% and 60.7%, respectively, at the short-term follow-up (p = 0.024) and 79.4%, 61.4% and 62.2%, respectively, at the long-term follow-up (p = 0.052). CONCLUSION: UAE is effective in treating patients with adenomyosis in both the short and long term. The outcomes of patients with adenomyosis were significantly correlated with lesion vascularity.

Operating Profitability of For-Profit and Not-for-Profit Florida Community Hospitals During Medicare Policy Changes, 2000 to 2010.

Medicare Advantage was implemented in 2004 and the Recovery Audit Contractor (RAC) program was implemented in Florida during 2005. Both increase surveillance of medical necessity and deny payments for improper admissions. The purpose of the present study was to determine their potential impact on for-profit (FP) and not-for-profit (NFP) hospital operating margins in Florida. FP hospitals were expected to be more adversely affected as admissions growth has been one strategy to improve stock performance, which is not a consideration at NFPs. This study analyzed Florida community hospitals from 2000 through 2010, assessing changes in pre-tax operating margin (PTOM). Florida Agency for Health Care Administration data were analyzed for 104 community hospitals (62 FPs and 42 NFPs). Academic, public, and small hospitals were excluded. A mixed-effects model was used to assess the association of RAC implementation, organizational and payer type variables, and ownership interaction effects on PTOM. FP hospitals began the period with a higher average PTOM, but converged with NFPs during the study period. The average Medicare Advantage effect was not significant for either ownership type. The magnitude of the RAC variable was significantly negative for average PTOM at FPs (-4.68) and positive at NFPs (0.08), meaning RAC was associated with decreasing PTOM at FP hospitals only. RAC complements other Medicare surveillance systems that detect medically unnecessary admissions, coding errors, fraud, and abuse. Since its implementation in Florida, average FP and NFP operating margins have been similar, such that the higher margins reported for FP hospitals in the 1990s are no longer evident.

Association between ABO gene polymorphism (rs505922) and cancer risk: a meta-analysis.

Previous studies have showed that ABO blood type is associated with multiple gastrointestinal cancers, including pancreatic cancer. Recently, one single nucleotide polymorphism (SNP) rs505922 in ABO gene has been implicated in susceptibility to pancreatic cancer across different populations, but different results were found in other types of cancer. This meta-analysis aimed to clarify the association. All eligible case-control studies were identified by searching through PubMed and Chinese language databases (CNKI and WanFang) up to September 1, 2014. Pooled estimates (odds ratio) were used to assess the strength of associations in fixed- or random-effects models. A total of nine studies with 10,304 cases and 15,564 controls were included. Overall, SNP rs505922 C allele was confirmed as a risk factor for cancer. Additionally, in further stratified analysis by cancer type, C allele carriers were more likely to have higher risk of pancreatic cancer. This study provided evidence of SNP rs505922 C allele as a strong risk factor of cancer susceptibility, specifically for pancreatic cancer.