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PK phenomenon

J Li, Y Liu, X Yu, J Zhang, J Gu, L Zhao
The study was aim to assess the impact of biochanin A on the oral bioavailability and pharmacokinetics (PK) of saquinavir (SQV), a substrate of P-glycoprotein (P-gp), in rats. 10 male rats were randomized into 2 groups of equal size, and administered orally 30 mg/kg SQV with or without 20 mg/kg biochanin A. The PK of SQV was assessed using non-compartmental analysis. Results revealed that the area under the plasma concentration-time curve of SQV from time zero to time infinity (AUC0-∞) was reduced by 51...
July 13, 2016: Drug Research
V V Cozac, L Rotaru
This literature review addresses the phenomenon of paradoxical kinesia (PK) in patients with Parkinson's disease (PD). PK is the sudden ability of the patient wit hPD to perform movements that were previously disturbed. This ability can be caused by different internal or environmental stressors. Different theories explaining the mechanism of paradoxical kinesia were proposed. In recent years, in the context of a search for new effective methods of treatment of akinesia I PD, methods of correction of motor impairment based on the phenomenon of PK are being developed...
2016: Zhurnal Nevrologii i Psikhiatrii Imeni S.S. Korsakova
Z Zhao, J Chen, W Peng, X Wang, Z Chen, H Tang, Y Liang, Z Ma, J Chen, X Chen, G Zhong, M Huang
Mildronate is an agent for cardioprotection and neuroprotection. This study aimed to evaluate the pharmacokinetic (PK) profiles, safety and tolerability of mildronate injection after single escalating doses and multiple doses in healthy Chinese subjects. We performed a randomized, open-label, single- and multiple-dose phase I trial including 3 doses of mildronate: 250, 500 and 750 mg. Plasma and urine samples were collected and concentrations of mildronate were analyzed by liquid chromatography-mass spectrometry (LC-MS/MS)...
May 2016: Drug Research
Phillip J Bergen, Zackery P Bulman, Cornelia B Landersdorfer, Nicholas Smith, Justin R Lenhard, Jürgen B Bulitta, Roger L Nation, Jian Li, Brian T Tsuji
Polymyxin combination therapy is increasingly used clinically. However, systematic investigations of such combinations are a relatively recent phenomenon. The emerging pharmacodynamic (PD) and pharmacokinetic (PK) data on CMS/colistin and polymyxin B suggest that caution is required with monotherapy. Given this situation, polymyxin combination therapy has been suggested as a possible way to increase bacterial killing and reduce the development of resistance. Considerable in vitro data have been generated in support of this view, particularly recent studies utilizing dynamic models...
December 2015: Infectious Diseases and Therapy
Samuel T Nemanich, Gammon M Earhart
INTRODUCTION: Gait dysfunction is common in people with Parkinson's disease (PD). Freezing of gait (FOG) is one such gait disturbance that significantly impacts mobility and quality of life in PD. Recent evidence suggests that cerebellar connectivity may differ in people with PD and FOG (PD+FOG) relative to those without FOG (PD-FOG). Investigation of gait adaptation, or the ability to change gait patterns in response to external perturbations, is cerebellum-dependent, is a practical means of probing cerebellar integrity and may provide additional insights regarding the FOG phenomenon...
January 2016: Parkinsonism & related Disorders
Ying Jing, Li Qin Zhu, Jian Wei Yang, Shu Ping Huang, Qian Wang, Jie Zhang
Rifampicin (RIF) induces cytochrome P450, which in turn catalyzes drug metabolism; however, pharmacokinetic studies on this phenomenon in the Chinese population, especially in the context of disease, are limited. Therefore, we sought to establish population-based pharmacokinetic models of RIF in a Chinese population with pulmonary tuberculosis (TB). Clinical data were retrospectively collected from 54 patients with pulmonary TB and analyzed alongside RIF blood levels from 95 samples collected prior to RIF administration and between 2 and 12 hours after treatment...
May 2016: Journal of Clinical Pharmacology
Kevin R Page, Enrica Mezzalana, Alexander J MacDonald, Stefano Zamuner, Giuseppe De Nicolao, Andre van Maurik
Otelixizumab is a monoclonal antibody (mAb) directed to human CD3ε, a protein forming part of the CD3/T-cell receptor (TCR) complex on T lymphocytes. This study investigated the temporal interaction between varying concentrations of otelixizumab, binding to human CD3 antigen, and expression of CD3/TCR complexes on lymphocytes in vitro, free from the confounding influence of changing lymphocyte frequencies observed in vivo. A static in vitro culture system was established in which primary human peripheral blood mononuclear cells (PBMCs) were incubated over an extended time course with titrated concentrations of otelixizumab...
November 2015: Journal of Pharmacology and Experimental Therapeutics
Enric Vidal, Natalia Fernández-Borges, Belén Pintado, Hasier Eraña, Montserrat Ordóñez, Mercedes Márquez, Francesca Chianini, Dolors Fondevila, Manuel A Sánchez-Martín, Olivier Andreoletti, Mark P Dagleish, Martí Pumarola, Joaquín Castilla
Interspecies transmission of prions is a well-established phenomenon, both experimentally and under field conditions. Upon passage through new hosts, prion strains have proven their capacity to change their properties and this is a source of strain diversity which needs to be considered when assessing the potential risks associated with consumption of prion contaminated protein sources. Rabbits were considered for decades to be a prion resistant species until proven otherwise recently. To determine the extent of rabbit susceptibility to prions and to assess the effects of passage of different prion strains through this species a transgenic mouse model overexpressing rabbit PrPC was developed (TgRab)...
August 2015: PLoS Pathogens
Darren M Riddy, Celine Valant, Patricia Rueda, William N Charman, Patrick M Sexton, Roger J Summers, Arthur Christopoulos, Christopher J Langmead
Drug receptor kinetics is as a key component in drug discovery, development, and efficacy; however, determining kinetic parameters has historically required direct radiolabeling or competition with a labeled tracer. Here we present a simple approach to determining the kinetics of competitive antagonists of G protein-coupled receptors by exploiting the phenomenon of hemi-equilibrium, the state of partial re-equilibration of agonist, antagonist, and receptor in some functional assays. Using functional [Ca(2+)]i-flux and extracellular kinases 1 and 2 phosphorylation assays that have short incubation times and therefore are prone to hemi-equilibrium "behaviors," we investigated a wide range of structurally and physicochemically distinct muscarinic acetylcholine receptor antagonists...
October 2015: Molecular Pharmacology
Yushan Chen, Shanshan Zhou, Kexin Hua, Hongde Xiao, Zili Li, Mei Liu, Rui Luo, Dingren Bi, Rui Zhou, Hui Jin
RANTES is a member of the CC chemokine involved in inflammation and immune response during pathogen infection. In our previous study, Haemophilus parasuis (H. parasuis), which is responsible for the great economic losses in the pig industry worldwide, has been shown to enhance RANTES expression in PK-15 cells. However, the mechanisms behind this biological phenomenon have remained unclear. In this study, we showed that H. parasuis infection significantly upregulated RANTES gene transcription in a time- and dose-dependent manner...
October 2015: Molecular Immunology
Minhee Kim, Juhee Kim, Jeong-Gyu Kim, Seunghun Hyun
Applicability of cosolvency model for describing the sorption of organic acids to humic substance was investigated by analyzing dataset of sorption (K m) and solubility (S m) of selected solutes (benzoic acid, 1-naphthoic acid, 2,4-dichlorophenoxyacetic acid, and 2,4,6-trichlorophenol (2,4,6-TCP)) as a function of pH(appCME) (apparent pH of liquid phase) and f c (methanol volume fractions). For all solutes, the K m decreased with f c with the K m reduction being less than the S m-based prediction. The slope of log K m-f c plot in the three organic carboxylic acids was well correlated with their cosolvency power, whereas the data of organic phenolic acid (2,4,6-TCP) was placed above the trend, indicating the different actions of functional groups...
October 2015: Environmental Science and Pollution Research International
Russell Thomson, Alan Finkelstein
Apolipoprotein L-1 (APOL1), the trypanolytic factor of human serum, can lyse several African trypanosome species including Trypanosoma brucei brucei, but not the human-infective pathogens T. brucei rhodesiense and T. brucei gambiense, which are resistant to lysis by human serum. Lysis follows the uptake of APOL1 into acidic endosomes and is apparently caused by colloid-osmotic swelling due to an increased ion permeability of the plasma membrane. Here we demonstrate that nanogram quantities of full-length recombinant APOL1 induce ideally cation-selective macroscopic conductances in planar lipid bilayers...
March 3, 2015: Proceedings of the National Academy of Sciences of the United States of America
Yang Yang, Xiao Song, Junjie Zhu, Xiao Zhou
Cancer Global Case ReportsSESSION TYPE: Global Case ReportPRESENTED ON: Tuesday, October 28, 2014 at 01:30 PM - 02:30 PMINTRODUCTION: Personalized target therapy of non-small cell lung cancer (NSCLC) is based on the mutation status of EGFR, KRAS, BRAF, and EML4-ALK fusion gene, and different mutations have different treatment. Herein, a rare case of adenocarcinoma of the lung harboring EGFR,BRAF and ALK activating mutations simultaneously was reported.CASE PRESENTATION: A 68-year-old male who is a light smoker (4 cigarettes per day) was admitted to our hospital in July 2013 because of chest distress and shortness of breath lasting > 2 years...
October 1, 2014: Chest
John M Allen, Shyam Gelot
Critically ill patients often are at high-risk for adverse drug reactions (ADRs), mainly due to alterations in pharmacokinetic and pharmacodynamic (PK/PD) parameters. These PK/PD differences in can also lead to inadequate therapeutic response to many commonly used drugs in this patient population. Frequently in the critically ill patient, medications are utilized based on a "trial-and-error" approach. Furthermore, drug dosing in the critically ill largely remains a "one-size-fits-all" phenomenon, utilizing dosing based on PK studies in healthy volunteers...
2014: Recent Patents on Biotechnology
Nayoung Han, Hwi-yeol Yun, In-Wha Kim, Yoon Jung Oh, Yon Su Kim, Jung Mi Oh
PURPOSE: Enteric-coated mycophenolate sodium (EC-MPS) is effective and safe in preventing rejection after transplantation and is mainly transported by ABCs and OATPs and metabolized by UGTs. The genetic polymorphisms affect the inter-individual variation in drug disposition and elimination. The aims of this study were to develop a population pharmacokinetic (PK) model and to evaluate the influence of genetic and clinical factors on the PK of mycophenolic acid (MPA) in Korean renal transplant recipients...
October 2014: European Journal of Clinical Pharmacology
Michael Osterman, Deion Kathawa, Diangang Liu, Huan Guo, Chao Zhang, Mo Li, Xiaochun Yu, Fei Li
Pancreatic cancer is one of the most aggressive and intractable human malignant tumors and a leading cause of cancer-related death across the world, with incidence equaling mortality. Because of the extremely high malignance, this disease is usually diagnosed at its advanced stage and recurs even after surgical excision. Pancreatic adenocarcinoma is generally thought to arise from pathological changes of pancreatic duct, and the pancreatic ductal adenocarcinoma accounts for more than 90 % of malignant neoplasms of the pancreas...
December 2014: Histochemistry and Cell Biology
In-Hwan Baek, Byung-Yo Lee, Jung-Woo Chae, Gyu Yong Song, Wonku Kang, Kwang-Il Kwon
1. JHL45, a novel immune modulator against atopic dermatitis (AD), was synthesized from decursin isolated from Angelica gigas. The goal is to evaluate the lead compound using quantitative modeling approaches to novel anti-AD drug development. 2. We tested the anti-inflammatory effect of JHL45 by in vitro screening, characterized its in vitro pharmacokinetic (PK) properties. The dose-dependent efficacy of JHL45 was developed using a pharmacokinetics/pharmacodynamics/disease progression (PK/PD/DIS) model in NC/Nga mice...
November 2014: Xenobiotica; the Fate of Foreign Compounds in Biological Systems
Anders Aufderhorst-Roberts, William J Frith, Athene M Donald
The real-time dynamic heterogeneity of the gelation process of the amino acid derivative Fmoc-tyrosine (Fmoc-Y) is studied using particle tracking microrheology. To trigger gelation, glucono-δ-lactone (GdL) is added, which gradually lowers the p H over several hours. The onset of self-assembly in the system is signified by a sharp drop in the mean-squared displacement of embedded particles, a phenomenon that is found to correlate with the p H of the system reaching the pK(a) of Fmoc-Y. The gel point is identified and found to be dependent on the GdL concentration...
May 2014: European Physical Journal. E, Soft Matter
Yu-Fen Lin, Hatsumi Nagasawa, John B Little, Takamitsu A Kato, Hung-Ying Shih, Xian-Jin Xie, Paul F Wilson, John R Brogan, Akihiro Kurimasa, David J Chen, Joel S Bedford, Benjamin P C Chen
We have examined cell-cycle dependence of chromosomal aberration induction and cell killing after high or low dose-rate γ irradiation in cells bearing DNA-PKcs mutations in the S2056 cluster, the T2609 cluster, or the kinase domain. We also compared sister chromatid exchanges (SCE) production by very low fluences of α-particles in DNA-PKcs mutant cells, and in homologous recombination repair (HRR) mutant cells including Rad51C, Rad51D, and Fancg/xrcc9. Generally, chromosomal aberrations and cell killing by γ-rays were similarly affected by mutations in DNA-PKcs, and these mutant cells were more sensitive in G1 than in S/G2 phase...
2014: PloS One
Jeffrey S Barrett
Optimal paediatric pharmacotherapy is reliant on a detailed understanding of the individual patient including their developmental status and disease state as well as the pharmaceutical agents he/she is receiving for treatment or management of side effects. Our appreciation for size and maturation effects on the pharmacokinetic/pharmacodynamic (PK/PD) phenomenon has improved to the point that we can develop predictive models that permit us to individualize therapy, especially in the situation where we are monitoring drug effects or therapeutic concentrations...
January 2015: British Journal of Clinical Pharmacology
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