Functional Implications of Genetic Polymorphisms in the Multidrug Resistance Gene MDR1 (ABCB1)

The multidrug resistance (MDR1) gene product P-glycoprotein is a membrane protein that functions as an ATP-dependent efflux pump, transporting exogenous and endogenous substrates from the inside of cells to the outside. Physiological expression of P-glycoprotein in tissues with excretory or protective function is a major determinant of drug disposition and provides a cellular defense mechanism against potentially harmful compounds. Therefore, P-glycoprotein has significant impact on therapeutic efficacy and toxicity as it plays a key role in absorption of oral medications from the intestinal tract, excretion into bile and urine, and distribution into protected tissues such as the brain and testes. There is increasing interest in the possible role of genetic variation in MDR1 in drug therapy. Numerous genetic polymorphisms in MDR1 have been described, some of which have been shown to determine P-glycoprotein expression levels and substrate transport. Furthermore, some of these polymorphisms have an impact on pharmacokinetic and pharmacodynamic profiles of drug substrates and directly influence outcome and prognosis of certain diseases. This review will focus on the impact of genetic variation in MDR1 on expression and function of P-glycoprotein and the implications of this variation for drug therapy and disease ris

Effect of ritonavir on the pharmacokinetics of the benzimidazoles albendazole and mebendazole: an interaction study in healthy volunteers

Background: Benzimidazoles are often used concomitantly with protease inhibitors in patients with helminthic disease and HIV infection. Low bioavailability and extensive first-pass metabolism make benzimidazoles prone to pharmacokinetic drug interactions. The aim of the present study was to investigate potential drug interactions between the benzimidazoles albendazole and mebendazole and the potent CYP3A4 inhibitor ritonavir. Methods: Sixteen healthy volunteers were administered a single oral dose of 1,000mg mebendazole or 400mg albendazole (2 × n = 8). AUC, Cmax, and t1/2 of mebendazole, albendazole, and albendazole sulfoxide were studied in absence and after short-term (2 doses) and long-term (8days) treatment with ritonavir 200mg bid. Results: Pharmacokinetic parameters of albendazole and mebendazole were not changed by short-term administration of ritonavir. However, long-term administration of ritonavir resulted in significant changes in albendazole and mebendazole disposition, with a significant decrease in AUC0-24 (27 and 43% of baseline for albendazole and mebendazole, respectively) and Cmax (26 and 41% of baseline, respectively). Conclusion: The AUC0-24 of benzimidazoles decreased after long-term use of ritonavir, while no changes in pharmacokinetic profiles were observed under short-term administration. These findings might help to optimize benzimidazole efficacy when used in combination with protease inhibitor

Incidence of drug-induced liver injury in medical inpatients

Objectives: Drug-induced liver injury (DILI) is a common concern. However, data on DILI epidemiology in inpatients are sparse. Methods: To investigate the incidence of DILI, we screened all patients in the pharmacoepidemiological inpatient database according to the CIOMS (Council for International Organisation of Medical Science) criteria, which consist of the evaluation of some clinical chemistry laboratory liver parameters (CIOMS laboratory criteria) and the exclusion of any disease-related causes for the liver injury. Thus, only cases with probable or certain causality according to the World Health Organization criteria were included. Results: Among a total of 6383 patients, liver parameters were determined in 4610, and 489 among them fulfilled the CIOMS laboratory criteria. However, 401 patients had to be excluded because of disease-related liver injury and, thus, the study cohort consisted of 4209 patients at risk for DILI. Among a total of 88 DILI cases, 31 had no documented normal baseline liver parameters and, thus, represented prevalent cases. The remaining 57 represented incident DILI cases. Thus, the incidence of DILI was 1.4% (95% CI 1.0, 1.7). The drug classes most frequently causing DILI were heparins, antibacterials, tuberculostatics and antineoplastic agents. Among those, antineoplastic agents and tuberculostatics showed the highest incidence. Liver injury was not mentioned among the diagnoses or in the physician's discharge letter in about 52-68% of all cases. Conclusion: Approximately 1 in 100 patients develops DILI during hospitalisation in a department of medicine. Incidences of DILI were highest for antineoplastic agents and tuberculostatics. DILI is frequently missed and, therefore, DILI detection by diagnoses will result in misleadingly low incidence rate

Health Data in Dentistry: An Attempt to Master the Digital Challenge

Biomedical research has recently moved through three stages in digital healthcare: (1) data collection; (2) data sharing; and (3) data analytics. With the explosion of stored health data (HD), dental medicine is edging into its fourth stage of digitization using artificial intelligence (AI). This narrative literature review outlines the challenge of managing HD and anticipating the potential of AI in oral healthcare and dental research by summarizing the current literature.; The basis of successful management of HD is the establishment of a generally accepted data standard that will guide its implementation within electronic health records (EHR) and health information technology ecosystems (HIT Eco). Thereby continuously adapted (self-) learning health systems (LHS) can be created. The HIT Eco of the future will combine (i) the front-end utilization of HD in clinical decision-making by providers using supportive diagnostic tools for patient-centered treatment planning, and (ii) back-end algorithms analyzing the standardized collected data to inform population-based policy decisions about resource allocations and research directions. Cryptographic methods in blockchain enable a safe, more efficient, and effective dental care within a global perspective. Key Message: The interoperability of HD with accessible digital health technologies is the key to deliver value-based dental care and exploit the tremendous potential of AI

Alveolar Echinococcosis of the Liver in an Adult with Human Immunodeficiency Virus Type-1 Infection

Abstract. : We describe a patient with human immunodeficiency virus type-1 (HIV) infection and alveolar echinococcosis (AE) with a focus on two messages. Despite being severely immunocompromised over years the patient exhibited a long-term asymptomatic course of AE. This is in clear contrast to reports describing accelerated courses of AE in immunocompromised patients. The patient had therapeutic mebendazole drug levels with only 1/10 of the normal drug dose. He was co-treated with protease inhibitors for his HIV infection. These drugs are known as strong inhibitors of cytochrome P450 3A4 (CYP3A4)-dependent metabolism. We speculate that benzimidazoles and protease inhibitors interfere at the CYP3A4-level. The first report of co-infection of HIV and accelerated AE was in a young girl with an extremely low CD4 cell count and an abrogated lymphoproliferative responsiveness to parasite antigen stimulation. Since the CD4 cell count in our patient remained in the range of 27-150 cells/µl, we speculate that there was a critical threshold of immunosupression for constraining AE. Initial treatment with albendazole for AE added to the current highly active antiretroviral treatment (HAART), and suppressive toxoplasmosis therapy became complicated by pancytopenia. After full recovery of the bone marrow, mebendazole was introduced with a new HAART and the previously prescribed toxoplasmosis maintenance therapy. Surprisingly, efficient mebendazole levels were achieved with an uncommonly low dose. These observations suggest that the benzimidazoles, albendazole and mebendazole, may interact with protease inhibitors, which are known for their strong inhibition of the CYP3A

The Dislocation Stress Functions From the Double Curl T(3)-Gauge Equation: Linearity and a Look Beyond

T(3)-gauge model of defects based on the gauge Lagrangian quadratic in the gauge field strength is considered. The equilibrium equation of the medium is fulfilled by the double curl Kroner's ansatz for stresses. The problem of replication of the static edge dislocation along third axis is analysed under a special, though conventional, choice of this ansatz. The translational gauge equation is shown to constraint the functions parametrizing the ansatz (the stress functions) so that the resulting stress component $\sigma_{3 3}$ is not that of the edge defect. Another translational gauge equation with the double curl differential operator is shown to reproduce both the stress functions, as well as the stress tensors, of the standard edge and screw dislocations. Non-linear extension of the newly proposed translational gauge equation is given to correct the linear defect solutions in next orders. New gauge Lagrangian is suggested in the Hilbert-Einstein form.Comment: 21 pages, LaTeX, no figure

Sensing the (digital) pulse. Future steps for improving the secondary use of data for research in Switzerland.

INTRODUCTION Ensuring that the health data infrastructure and governance permits an efficient secondary use of data for research is a policy priority for many countries. Switzerland is no exception and many initiatives have been launched to improve its health data landscape. The country now stands at an important crossroad, debating the right way forward. We aimed to explore which specific elements of data governance can facilitate - from ethico-legal and socio-cultural perspectives - the sharing and reuse of data for research purposes in Switzerland. METHODS A modified Delphi methodology was used to collect and structure input from a panel of experts via successive rounds of mediated interaction on the topic of health data governance in Switzerland. RESULTS First, we suggested techniques to facilitate data sharing practices, especially when data are shared between researchers or from healthcare institutions to researchers. Second, we identified ways to improve the interaction between data protection law and the reuse of data for research, and the ways of implementing informed consent in this context. Third, we put forth ideas on policy changes, such as the steps necessary to improve coordination between different actors of the data landscape and to win the defensive and risk-adverse attitudes widespread when it comes to health data. CONCLUSIONS After having engaged with these topics, we highlighted the importance of focusing on non-technical aspects to improve the data-readiness of a country (e.g., attitudes of stakeholders involved) and of having a pro-active debate between the different institutional actors, ethico-legal experts and society at large

Overcoming Cancer Multidrug Resistance by Codelivery of Doxorubicin and Verapamil with Hydrogel Nanoparticles

The efficacy of chemotherapy is often inhibited by multidrug resistance (MDR). A highly engineerable hydrogel nanoparticle (NP) serves as a carrier for the optimal codelivery to tumor cells of the chemodrug, doxorubicin (Dox) and the chemosensitizer, verapamil (Vera), aiming at alleviating tumor MDR. The hydrogel NPs are prepared via the copolymerization of acrylamide and 2‐carboxyethyl acrylate. Dox and Vera are post‐loaded into the respective NPs, with drug loading around 7.7 wt% and 8.0 wt%, respectively. The codelivery of Dox‐NPs and Vera‐NPs increases the intracellular accumulation of Dox, and significantly enhances the cell killing ability of Dox with respect to NCI/ADR‐RES cells in vitro. These findings suggest that such codelivery nanoplatforms provide a promising route for overcoming tumor MDR. A new kind of hydrogel nanoparticles is developed as a delivery vehicle for codelivery of doxorubicin, an anti‐cancer drug (affects DNA), and verapamil, a chemosensitizer (blocks efflux pump), to tumor cells, aiming at overcoming multidrug resistance.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/108282/1/mabi201400035.pd

Locally increased P-glycoprotein function in major depression: a PET study with [C-11]verapamil as a probe for P-glycoprotein function in the blood-brain barrier

The aetiology of depressive disorder remains unknown, although genetic susceptibility and exposure to neurotoxins are currently being discussed as possible contributors to this disorder. In normal circumstances, the brain is protected against bloodborne toxic influences by the blood-brain barrier, which includes the molecular efflux pump P-glycoprotein (P-gp) in the vessel wall of brain capillaries. We hypothesized that P-gp function in the blood-brain barrier is changed in patients with major depression. Positron emission tomography Was used to measure brain uptake of [C-11]verapamil, which is normally expelled from the brain by P-gp. Cerebral Volume of distribution (V-T) of [C-11]verapamil was used as a measure of P-gp function. Both region-of-interest (ROI) analysis and voxel analysis using statistical parametric mapping (SPM2) were performed to assess regional brain P-gp function. We found that patients with a major depressive episode, using antidepressants, compared to health), controls showed a significant decrease of [C-11]verapamil uptake in different areas throughout the brain, in particular in frontal and temporal regions. The decreased [C-11]verapamil uptake correlates with an increased function of the P-gp protein and may be related to chronic use of psychotropic drugs, Our results may explain why treatment-resistant depression can develop