Identification of Binding Sites in the Nucleotide-Binding Domain of P-Glycoprotein for a Potent and Nontoxic Modulator, the Amine-Containing Monomeric Flavonoid .

We have previously discovered an amine-containing flavonoid monomer as a potent P-glycoprotein (P-gp) inhibitor (EC = 83 nM). Here, a series of photoactive analogues were synthesized and used together with liquid chromatography-tandem mass spectrometry (LC-MS/MS) to identify the -binding sites on P-gp. Point mutations around the photo-crosslinked sites were made for verification.

Discovery of a Flavonoid FM04 as a Potent Inhibitor to Reverse P-Glycoprotein-Mediated Drug Resistance in Xenografts and Improve Oral Bioavailability of Paclitaxel.

Biotransformation of flavonoid dimer FD18 resulted in an active metabolite FM04. It was more druggable because of its improved physicochemical properties. FM04 (EC50 = 83 nM) was 1.

Characterization of a Potent, Selective, and Safe Inhibitor, Ac15(Az8), in Reversing Multidrug Resistance Mediated by Breast Cancer Resistance Protein (BCRP/ABCG2).

Overexpression of breast cancer resistance transporter (BCRP/ABCG2) in cancers has been explained for the failure of chemotherapy in clinic. Inhibition of the transport activity of BCRP during chemotherapy should reverse multidrug resistance. In this study, a triazole-bridged flavonoid dimer was identified as a potent, nontoxic, and selective BCRP inhibitor.

Boosting the efficacy of anti-MRSA β-lactam antibiotics via an easily accessible, non-cytotoxic and orally bioavailable FtsZ inhibitor.

The rapid emergence of methicillin-resistant Staphylococcus aureus (MRSA) strains has undermined the therapeutic efficacy of existing β-lactam antibiotics (BLAs), prompting an urgent need to discover novel BLAs adjuvants that can potentiate their anti-MRSA activities. In this study, cytotoxicity and antibacterial screening of a focused compound library enabled us to identify a compound, namely 28, which exhibited low cytotoxicity against normal cells and robust in vitro bactericidal synergy with different classes of BLAs against a panel of multidrug-resistant clinical MRSA isolates. A series of biochemical assays and microscopic studies have revealed that compound 28 is likely to interact with the S.

A New Class of Safe, Potent, and Specific P-gp Modulator: Flavonoid Dimer FD18 Reverses P-gp-Mediated Multidrug Resistance in Human Breast Xenograft in Vivo.

Flavonoid dimer FD18 is a new class of dimeric P-gp modulator that can reverse cancer drug resistance. FD18 is a potent (EC50 = 148 nM for paclitaxel), safe (selective index = 574), and selective P-glycoprotein (P-gp) modulator. FD18 can modulate multidrug resistance toward paclitaxel, vinblastine, vincristine, doxorubicin, daunorubicin, and mitoxantrone in human breast cancer LCC6MDR in vitro.

Macrolides are associated with a better survival rate in patients hospitalized with community-acquired but not healthcare-associated pneumonia.

Background: Macrolide-based treatment has been associated with survival benefit in patients hospitalized with community-acquired pneumonia (CAP). However, the influence of macrolide therapy in all patients hospitalized with pneumonia, including healthcare-associated pneumonia (HCAP), is unclear.

Methods: Analysis of a retrospective single-center cohort.

Azithromycin and survival in Streptococcus pneumoniae pneumonia: a retrospective study.

Objective: Streptococcus pneumoniae (SP) represents a major pathogen in pneumonia. The impact of azithromycin on mortality in SP pneumonia remains unclear. Recent safety concerns regarding azithromycin have raised alarm about this agent's role with pneumonia.

Readmission following hospitalization for pneumonia: the impact of pneumonia type and its implication for hospitals.

Background: Readmission rates following discharge after pneumonia are thought to represent the quality of care. Factors associated with readmission, however, remain poorly described. It is unclear if readmission rates vary based on pneumonia type.

Amine linked flavonoid dimers as modulators for P-glycoprotein-based multidrug resistance: structure-activity relationship and mechanism of modulation.

Here we report a great improvement in reversal potency of cancer drug resistance when flavonoid dimers possess a functionally substituted aminopolyethylene glycol linker. The most potent compound, 18, contains a N-benzyl group at the linker. It has many advantages including (1) high potencies in reversing P-glycoprotein (P-gp) mediated resistance in LCC6MDR cells to various anticancer drugs with EC(50) in the nanomolar range, (2) low toxicity and high therapeutic index, and (3) preferential inhibition of P-gp over multidrug resistance protein 1 and breast cancer resistance protein.

Validation of a clinical score for assessing the risk of resistant pathogens in patients with pneumonia presenting to the emergency department.

Background: Resistant organisms (ROs) are increasingly implicated in pneumonia in patients presenting to the emergency department (ED). The concept of healthcare-associated pneumonia (HCAP) exists to help identify patients infected with ROs but may be overly broad. We sought to validate a previously developed score for determining the risk for an RO and to compare it with the HCAP definition.

Proteolysis of MLL family proteins is essential for taspase1-orchestrated cell cycle progression.

Taspase1 was identified as the threonine endopeptidase that cleaves mixed-lineage leukemia (MLL) for proper Hox gene expression in vitro. To investigate its functions in vivo, we generated Taspase1(-/-) mice. Taspase1 deficiency results in noncleavage (nc) of MLL and MLL2 and homeotic transformations.