• Title/Summary/Keyword: pharmacodynamic

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Physiologically Based Pharmacokinetic (PBPK) Modeling in Neurotoxicology

  • Kim, Chung-Sim
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1995.10a
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    • pp.135-136
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    • 1995
  • Resent advances in computer technology have introduced a sophisticated capability for computing the biological fate of toxicants in a biological system. This methodology, which has drastically altered risk assessment skill in toxicology, is designed using all the mechanistic information, and all claim better accuracy with extrapolating capability Iron animal to people than conventional pharmacokinetic methods. Biologically based mathematical models in which the specific mechanistic steps governing tissue disposition(pharmacokinetics) and toxic action (pharmacodynamics) of chemicals are constructed in quantitative terms by a set of equations loading to prediction of the outcome of specific toxicological experiments by computer simulation. pharmacokinetic and pharmacodynamic models are useful in risk assessment because their mechanistic biological basis permits the high-to-low dose, route to route and interspecies extrapolation of the tissue disposition and toxic action of chemicals.

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Postantibiotic Effects and Postantibiotic Sub-MIC Effects of Antibiotics on Treponema Denticola

  • Lee, Si-Young
    • International Journal of Oral Biology
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    • v.34 no.3
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    • pp.165-168
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    • 2009
  • Postantibiotic effect (PAE) is defined as the length of time that bacterial growth is suppressed following brief exposure to an antibiotic. In this study, the in vitro PAE, postantibiotic sub-MIC effect (PA SME) and sub-MIC effect (SME) of antibiotics on Treponema denticola ATCC 35405 were investigated. The PAE of doxycycline and metronidazole were 20.3 h and 25.0 h, respectively. The PA SMEs examined by addition of 0.1, 0.2 and 0.3X MICs during the postantibiotic phase of the bacteria for metronidazole were longer than those for doxycycline. In contrast, the SMEs for doxycycline were longer than those for metronidazole. The PA-SME and SME values increased as the concentration of antibiotics increased. The present study illustrates the existence of PAE, PA-SME and SME for several antibiotics against T. denticola, thereby extending the pharmacodynamic advantages of these antibiotics.

Drug-Drug Interactions : Mood Stabilizers and Anti-Anxiety Drugs (약물상호작용 : 기분안정제와 항불안제)

  • Kim, Young Hoon;Rhee, Jung Goo
    • Korean Journal of Biological Psychiatry
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    • v.7 no.1
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    • pp.34-45
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    • 2000
  • Pharmacotherapy of bipolar disorder is a rapidly evolving field. Mood stabilizers and anticonvulsants have varying biochemical profiles which may predispose them to different adverse effects and drug-drug interactions. Several of the new anticonvulsants appear less likely to have the problems with drug-drug interaction. To provide more effective combination pharmacotherapies, clinicians should be allowed to anticipate and avoid pharmacokinetic and pharmacodynamic drug-drug interactions. We reviewed the role of cytochrome P450 isozymes in the metabolism of the drugs and their interactions. The drug-drug interactions of several classes of drugs which used as mood stabilizers and new anticonvulsants, some of which may have psychotropic profiles, are discussed mainly in this article. Finally, potential pharmacokinetic interactions between the benzodiazepines and other coadministered drugs are discussed briefly.

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Characteristics of Some Animal Models of Experimental Renal Failure (실험적 신장해 모델의 특성 비교)

  • Shim, Chang-Koo
    • Journal of Pharmaceutical Investigation
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    • v.17 no.4
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    • pp.205-211
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    • 1987
  • Renal dysfunction can have pronounced effects on the pharmacokinetic and pharmacodynamic characteristics of drugs. Because the exploration of these effects in patients may be limited by ethical and practical considerations, it often become necessary to perform studies on animals with experimental renal failure(ERF). ERF was produced in rats by the administration of uranyl nitrate, glycerol, salicylate, gentamicin and folate in this study. Changes in glomerular filtration rate(GFR) and renal secretion clearance of tetraethylammonium bromide$(CL^{scn}_{TEA})$, together with morphological changes of kidney cortex were evaluated and compared among ERF models. GFR(or glomeruli) and $CL^{scn}_{TEA}$(or renal tubules) were not damaged parallelly in some ERF model rats. Therefore, it seemed to be necessary to adjust dosage regimen of some basic drugs like TEA in renal dysfunction considering the functional changes of renal secretion in addition to glomerular filtration.

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Chirality of Drug Molecules and Biological Activity (의약품의 손대칭성과 생리 활성)

  • 권순경
    • Biomolecules & Therapeutics
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    • v.4 no.3
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    • pp.209-223
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    • 1996
  • Chirality is important in the context of biological activity because at a molecular level, asymmetry dominates biological process. While most pharmaceuticals of natural origin are single enantiomers, most of the synthesized chiral drugs are used in the form of racemic mixtures of two or more diastereomers. The enantiomers of a racemic drug generally differ in pharmacodynamic and pharmacokinetic properties as a consequence of stereoselective interaction with optically active molecular components of living organism. In pharmacokinetics and pharmacodynamics enantioselectivity plays an important role. The information on the sum of eutomer and distorter in a racemic drugs is very important in the estimation of therapeutic advantage and/or toxicity of racemates. The choice of preferentially developing a single enantiomer should be based on actual therapeutic advantages and especially improved safety.

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Pharmacodynamic principles and target concentration intervention

  • Holford, Nick
    • Translational and Clinical Pharmacology
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    • v.26 no.4
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    • pp.150-154
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    • 2018
  • This tutorial reviews the principles of dose individualisation with an emphasis on target concentration intervention (TCI). Once a target effect is chosen then pharmacodynamics can predict the target concentration and pharmacokinetics can predict the target dose to achieve the required response. Dose individualisation can be considered at three levels: population, group and individual. Population dosing, also known as fixed dosing or "one size fits all" is often used but is poor clinical pharmacology; group dosing uses patient features such as weight, organ function and comedication to adjust the dose for a typical patient; individual dosing uses observations of patient response to inform about pharmacokinetic and pharmacodynamics in the individual and use these individual differences to individualise dose.

Mechanistic ligand-receptor interaction model: operational model of agonism

  • Kim, Hyungsub;Lim, Hyeong-Seok
    • Translational and Clinical Pharmacology
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    • v.26 no.3
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    • pp.115-117
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    • 2018
  • This tutorial explains the basic principles of mechanistic ligand-receptor interaction model, which is an operational model of agonism. A growing number of agonist drugs, especially immune oncology drugs, is currently being developed. In this tutorial, time-dependent ordinary differential equation for simple $E_{max}$ operational model of agonism was derived step by step. The differential equation could be applied in a pharmacodynamic modeling software, such as NONMEM, for use in non-steady state experiments, in which experimental data are generated while the interaction between ligand and receptor changes over time. Making the most of the non-steady state experimental data would simplify the experimental processes, and furthermore allow us to identify more detailed kinetics of a potential drug. The operational model of agonism could be useful to predict the optimal dose for agonistic drugs from in vitro and in vivo animal pharmacology experiments at the very early phase of drug development.

EXTERNAL GEL FORMULATIONS OF PROSTAGLANDIN E1 ETHYL ESTER

  • Kim, Hee-Kyu;Kim, Jong-Seok;Lee, Sang-Kil;Yang, Sung-Woon;Lee, Ji-Eun;Choi, Han-Gon;Yong, Chulsoon;Choi, Young-Wook
    • Proceedings of the PSK Conference
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    • 2003.04a
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    • pp.296.1-296.1
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    • 2003
  • Purpose. External gel formulations of prostaglandin E1 ethyl ester (PGE1-EE), a prod rug of PGE1 as a therapeutic agent for erectile dysfunction, were tried and evaluated by in vitro skin penetration characteristics and in vivo pharmacodynamic effects in cat. Method. The in vitro skin penetration was performed with Franz diffusion cell and examined in aspects of alcohol/polyol ratios and various enhancers. (omitted)

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Ambient Mass Spectrometry in Imaging and Profiling of Single Cells: An Overview

  • Bharath Sampath Kumar
    • Mass Spectrometry Letters
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    • v.14 no.4
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    • pp.121-140
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    • 2023
  • It is becoming more and more clear that each cell, even those of the same type, has a unique identity. This sophistication and the diversity of cell types in tissue are what are pushing the necessity for spatially distributed omics at the single-cell (SC) level. Single-cell chemical assessment, which also provides considerable insight into biological, clinical, pharmacodynamic, pathological, and toxicity studies, is crucial to the investigation of cellular omics (genomics, metabolomics, etc.). Mass spectrometry (MS) as a tool to image and profile single cells and subcellular organelles facilitates novel technical expertise for biochemical and biomedical research, such as assessing the intracellular distribution of drugs and the biochemical diversity of cellular populations. It has been illustrated that ambient mass spectrometry (AMS) is a valuable tool for the rapid, straightforward, and simple analysis of cellular and sub-cellular constituents and metabolites in their native state. This short review examines the advances in ambient mass spectrometry (AMS) and ambient mass spectrometry imaging (AMSI) on single-cell analysis that have been authored in recent years. The discussion also touches on typical single-cell AMS assessments and implementations.