Meta-Dimethylation of Arenes via Catellani Reaction from Aryl Thianthrenium Salts.

Here we report the reaction of aryl thianthrenium salts that allows selective functionalization of the meta position of arenes. The combination of a site-selective thianthrenation with a Catellani reaction provides access to 3,5-dimethylated arenes. The developed reaction is complementary to the previously discovered reductive ipso-alkylation of aryl thianthrenium salts and extends the possibilities for late-stage methylation of arenes with a single aryl thianthrenium salt.

Early-infantile developmental and epileptic encephalopathy: the aetiologies, phenotypic differences and outcomes-a prospective observational study.

In this study, we have evaluated the underlying aetiologies, yield of genetic testing and long-term outcomes in patients with early-infantile developmental and epileptic encephalopathies. We have prospectively studied patients with seizure onset before 3 months of age. Based on the clinical details, neuroimaging, metabolic testing and comprehensive genetic evaluation, patients were classified into different aetiological groups.

Photoinduced Copper-Catalyzed Late-Stage Azidoarylation of Alkenes via Arylthianthrenium Salts.

The arylethylamine pharmacophore is conserved across a range of biologically active natural products and pharmaceuticals, particularly in molecules that act on the central nervous system. Herein, we present a photoinduced copper-catalyzed azidoarylation of alkenes at a late stage with arylthianthrenium salts, allowing access to highly functionalized acyclic (hetero)arylethylamine scaffolds that are otherwise difficult to access. A mechanistic study is consistent with a -BINAP-Cu-azide () as the photoactive catalytic species.

The Burden of Cervical Conization in Privately Insured Young and Mid-Adult Women in the United States.

In 2019, the United States (US) Advisory Committee on Immunization Practices (ACIP) recommended that healthcare providers engage in shared clinical decision making for adults aged 27-45 who may benefit from HPV vaccination. However, it is difficult to assess these benefits as there is a lack of data on HPV burden on young and mid-adult women. This analysis estimates the incidence of conization and the burden associated with treating pre-cancerous states related to HPV with a loop electrosurgical excision procedure (LEEP) or a cold knife conization (CKC) among commercially insured women aged 18-45.

Impact of switching prophylaxis treatment from factor VIII to emicizumab in hemophilia A patients without inhibitors.

Background: Factor VIII (FVIII) replacement and emicizumab are effective at preventing bleeds in patients with hemophilia A (HA). Though benefits of emicizumab among inhibitor patients with HA (PwHA) are well established, more real-world evidence among non-inhibitor patients is needed.

Methods: Using a United States healthcare claims database, we compared billed annualized bleed rates (ABR) and the total cost of care (TCC) before and after switching from FVIII prophylaxis to emicizumab among non-inhibitor male PwHA.

Enroute sustainability: metal free C-H bond functionalisation.

The term "C-H functionalisation" incorporates C-H activation followed by its transformation. In a single line, this can be defined as the conversion of carbon-hydrogen bonds into carbon-carbon or carbon-heteroatom bonds. The catalytic functionalisation of C-H bonds using transition metals has emerged as an atom-economical technique to engender new bonds without activated precursors which can be considered as a major drawback while attempting large-scale synthesis.

Recent advances in the in vitro and in vivo methods to assess impact of P-glycoprotein and breast cancer resistance protein transporters in central nervous system drug disposition.

One challenge in central nervous system (CNS) drug discovery has been ensuring the blood-brain barrier (BBB) penetration of compounds at an efficacious concentration that provides suitable safety margins for clinical investigation. Research providing for the accurate prediction of brain penetration of compounds during preclinical discovery is important to a CNS program. In the BBB, P-glycoprotein (P-gp) (ABCB1) and breast cancer resistance protein (BCRP) (ABCG2) transporters have been demonstrated to play a major role in the active efflux of endogenous compounds and xenobiotics out of the brain microvessel cells and back to the systemic circulation.

A real-world study comparing pre-post billed annualized bleed rates and total cost of care among non-inhibitor patients with hemophilia A switching from FVIII prophylaxis to emicizumab.

Objective: Factor VIII (FVIII) replacement and emicizumab have demonstrated efficacy for prevention of bleeds among patients with hemophilia A (PwHA) compared to on-demand (OD) use. Evidence investigating clinical outcomes and healthcare costs of non-inhibitor PwHA switching from prophylaxis with FVIII concentrates to emicizumab has not been well-established within large real-world datasets. This study aimed to investigate billed annualized bleed rates (ABR) and total cost of care (TCC) among non-inhibitor PwHA switching from FVIII-prophylaxis to emicizumab-prophylaxis.

Repression of Organic Anion Transporting Polypeptide (OATP) 1B Expression and Increase of Plasma Coproporphyrin Level as Evidence for OATP1B Downregulation in Cynomolgus Monkeys Treated with Chenodeoxycholic Acid.

Farnesoid X receptor (FXR) is a nuclear receptor known to markedly alter expression of major transporters and enzymes in the liver. However, its effects toward organic anion transporting polypeptides (OATP) 1B1 and 1B3 remain poorly characterized. Therefore, the present study was aimed at determining the effects of chenodeoxycholic acid (CDCA), a naturally occurring FXR agonist, on OATP1B expression in cynomolgus monkeys.

Bosentan Alters Endo- and Exogenous Bile Salt Disposition in Sandwich-Cultured Human Hepatocytes.

Bosentan, a well-known cholestatic agent, was not identified as cholestatic at concentrations up to 200 µM based on the drug-induced cholestasis (DIC) index value, determined in a sandwich-cultured human hepatocyte (SCHH)-based DIC assay. To obtain further quantitative insights into the effects of bosentan on cellular bile salt handling by human hepatocytes, the present study determined the effect of 2.5-25 µM bosentan on endogenous bile salt levels and on the disposition of 10 µM chenodeoxycholic acid (CDCA) added to the medium in SCHHs.

Characteristics, treatment patterns, healthcare resource use, and costs among pediatric patients diagnosed with neurofibromatosis type 1 and plexiform neurofibromas: a retrospective database analysis of a medicaid population.

Objectives: The objectives of this study were to describe the characteristics and initial treatment patterns, healthcare resource use (HCRU), and costs of patients newly diagnosed with neurofibromatosis type 1 (NF1)-related plexiform neurofibromas (PN).

Methods: This was a retrospective study of individuals enrolled in the IBM MarketScan Multi-State Medicaid database from 1 October 2014 to 31 December 2017. Patients aged ≤18 years at the index date (first diagnosis of NF1 or PN, whichever occurred later) with at least 1 ICD-10-CM diagnosis code for both NF1 and PN were included.

Transporter Activity Changes in Nonalcoholic Steatohepatitis: Assessment with Plasma Coproporphyrin I and III.

Expression and functional changes in the organic anion transporting polypeptide (OATP)-multidrug resistance-associated protein (MRP) axis of transporters are well reported in patients with nonalcoholic steatohepatitis (NASH). These changes can impact plasma and tissue disposition of endo- and exogenous compounds. The transporter alterations are often assessed by administration of a xenobiotic or by transporter proteomic analysis from liver biopsies.

Treatment, Resource Use and Costs Among Pediatric Patients with Neurofibromatosis Type 1 and Plexiform Neurofibromas.

Background: Neurofibromatosis type 1 (NF1) is an autosomal dominant genetic condition which predisposes individuals to tumors of the nervous system, skin, bones, and eyes. Plexiform neurofibromas (PNs) occur in 20-50% of NF1 cases, causing multiple morbidities and conferring a risk of malignancy. NF1 with PN is poorly characterized in the literature with regard to treatment patterns, healthcare resource utilization, and costs in the real world.

Drug-induced cholestasis assay in primary hepatocytes.

Drug-induced cholestasis (DIC) is a major cause of clinical failure of drug candidates. Numerous patients worldwide are affected when exposed to marketed drugs exhibiting a DIC signature. Prospective identification of DIC during early compound development remains challenging.

Is aspirin a substrate of MDR1/P-glycoprotein?

Aspirin (acetyl salicylic acid) is widely used co-medication in patients with cardiovascular and cerebrovascular diseases. Given the prevalence of acetyl salicylic acid's use as a co-medication and conflicting reports in the literature on it being a substrate of P-glycoprotein (P-gp). There is a potential risk for its interaction with compounds with P-gp liability, therefore, we have conducted a detailed investigation to determine substrate potential of acetyl salicylic acid towards P-gp.

In Vitro Stimulation of Multidrug Resistance-Associated Protein 2 Function Is Not Reproduced In Vivo in Rats.

Previously we reported that coproporphyrin-I (CP-I) is an optimal probe substrate for multidrug resistance-associated protein 2 (MRP2), and stimulation of MRP2-mediated transport is probe substrate-dependent. In the present investigation, we assessed if the in vitro stimulation is physiologically relevant. Similar to human MRP2 transport, CP-I was transported by rat Mrp2 in a typical Michaelis-Menten kinetics with apparent K and V values of 15 ± 6 µM and 161 ± 20 pmol/min/mg protein, respectively.

Drug-induced Cholestasis: Mechanisms, Models, and Markers.

Background: Drug-induced cholestasis is a risk factor in the progression of drug candidates, and poses a serious health hazard if not detected before going into a human. Intrahepatic accumulation of Bile Acids (BAs) represents a characteristic phenomenon associated with drug-induced cholestasis.

Methods: This review will discuss the current knowledge and knowledge gaps regarding drug-induced cholestasis, such as complexity of BA-mediated toxicity mechanisms, disconnect in signatures of toxicity between clinical and preclinical models, and the impact of bile acids at different 'targets' such as transporters, enzymes and nuclear receptors.

Coproporphyrin-I: A Fluorescent, Endogenous Optimal Probe Substrate for ABCC2 (MRP2) Suitable for Vesicle-Based MRP2 Inhibition Assay.

Inside-out-oriented membrane vesicles are useful tools to investigate whether a compound can be an inhibitor of efflux transporters such as multidrug resistance-associated protein 2 (MRP2). However, because of technical limitations of substrate diffusion and low dynamic uptake windows for interacting drugs used in the clinic, estradiol-17-glucuronide (E17G) remains the probe substrate that is frequently used in MRP2 inhibition assays. Here we recapitulated the sigmoidal kinetics of MRP2-mediated transport of E17G, with apparent Michaelis-Menten constant () and values of 170 ±17 M and 1447 ± 137 pmol/mg protein/min, respectively.

The FXR agonist obeticholic acid prevents gut barrier dysfunction and bacterial translocation in cholestatic rats.

Bacterial translocation (BTL) drives pathogenesis and complications of cirrhosis. Farnesoid X-activated receptor (FXR) is a key transcription regulator in hepatic and intestinal bile metabolism. We studied potential intestinal FXR dysfunction in a rat model of cholestatic liver injury and evaluated effects of obeticholic acid (INT-747), an FXR agonist, on gut permeability, inflammation, and BTL.

Confocal imaging with a fluorescent bile acid analogue closely mimicking hepatic taurocholate disposition.

This study aimed to characterize the in vitro hepatic transport mechanisms in primary rat and human hepatocytes of the fluorescent bile acid derivative N-(24-[7-(4-N,N-dimethylaminosulfonyl-2,1,3-benzoxadiazole)]amino-3α,7α,12α-trihydroxy-27-nor-5β-cholestan-26-oyl)-2'-aminoethanesulfonate (tauro-nor-THCA-24-DBD), previously synthesized to study the activity of the bile salt export pump (BSEP). The fluorescent bile acid derivative exhibited saturable uptake kinetics in suspended rat hepatocytes. Hepatic uptake was inhibited in the presence of substrates/inhibitors of the organic anion transporting polypeptide (Oatp) family and Na(+) -taurocholate cotransporting peptide (Ntcp).

Toxicity and intracellular accumulation of bile acids in sandwich-cultured rat hepatocytes: role of glycine conjugates.

Excessive intrahepatic accumulation of bile acids (BAs) is a key mechanism underlying cholestasis. The aim of this study was to quantitatively explore the relationship between cytotoxicity of BAs and their intracellular accumulation in sandwich-cultured rat hepatocytes (SCRH). Following exposure of SCRH (on day-1 after seeding) to various BAs for 24h, glycine-conjugated BAs were most potent in exerting toxicity.

Hepatocyte-based in vitro model for assessment of drug-induced cholestasis.

Early detection of drug-induced cholestasis remains a challenge during drug development. We have developed and validated a biorelevant sandwich-cultured hepatocytes- (SCH) based model that can identify compounds causing cholestasis by altering bile acid disposition. Human and rat SCH were exposed (24-48h) to known cholestatic and/or hepatotoxic compounds, in the presence or in the absence of a concentrated mixture of bile acids (BAs).

Sandwich-cultured hepatocytes: utility for in vitro exploration of hepatobiliary drug disposition and drug-induced hepatotoxicity.

Introduction: The sandwich-cultured hepatocyte (SCH) model has become an invaluable in vitro tool for studying hepatic drug transport, metabolism, biliary excretion and toxicity. The relevant expression of many hepatocyte-specific functions together with the in vivo-like morphology favor SCHs over other preclinical models for evaluating hepatobiliary drug disposition and drug-induced hepatotoxicity.

Areas Covered: In this review, the authors highlight recommended procedures required for reproducibly culturing hepatocytes in sandwich configuration.