94 research outputs found
Time-domain direct and inverse scattering for bi-anisotropic slabs at oblique incidence
Effect of Dissipation on the Constitutive Relations of Bi-Anisotropic Mediaâthe Optical Response
On The Rate and Extent of Drug Delivery to the Brain
To define and differentiate relevant aspects of bloodâbrain barrier transport and distribution in order to aid research methodology in brain drug delivery. Pharmacokinetic parameters relative to the rate and extent of brain drug delivery are described and illustrated with relevant data, with special emphasis on the unbound, pharmacologically active drug molecule. Drug delivery to the brain can be comprehensively described using three parameters: Kp,uu (concentration ratio of unbound drug in brain to blood), CLin (permeability clearance into the brain), and Vu,brain (intra-brain distribution). The permeability of the bloodâbrain barrier is less relevant to drug action within the CNS than the extent of drug delivery, as most drugs are administered on a continuous (repeated) basis. Kp,uu can differ between CNS-active drugs by a factor of up to 150-fold. This range is much smaller than that for log BB ratios (Kp), which can differ by up to at least 2,000-fold, or for BBB permeabilities, which span an even larger range (up to at least 20,000-fold difference). Methods that measure the three parameters Kp,uu, CLin, and Vu,brain can give clinically valuable estimates of brain drug delivery in early drug discovery programmes
Prediction of brain clozapine and norclozapine concentrations in humans from a scaled pharmacokinetic model for rat brain and plasma pharmacokinetics
Changes in muscle-tendon unit length-force characteristics following experimentally induced photothrombotic stroke cannot be explained by changes in muscle belly structure.
Purpose The aim of this study was to assess the effects of experimentally induced photothrombotic stroke on structural and mechanical properties of rat m. flexor carpi ulnaris. Methods Two groups of Young-adult male SpragueâDawley rats were measured: stroke (nâ=â9) and control (nâ=â7). Photothrombotic stroke was induced in the forelimb region of the primary sensorimotor cortex. Four weeks later, muscleâtendon unit and muscle belly lengthâforce characteristics of the m. flexor carpi ulnaris, mechanical interaction with the neighbouring m. palmaris longus, the number of sarcomeres in series within muscle fibres, and the physiological cross-sectional area were measured. Results Stroke resulted in higher force and stiffness of the m. flexor carpi ulnaris at optimum muscleâtendon unit length, but only for the passive conditions. Stroke did not alter the lengthâforce characteristics of m. flexor carpi ulnaris muscle belly, morphological characteristics, and the extent of mechanical interaction with m. palmaris longus muscle. Conclusion The higher passive force and passive stiffness at the muscleâtendon unit level in the absence of changes in structural and mechanical characteristics of the muscle belly indicates that the experimentally induced stroke resulted in an increased stiffness of the tendon
Physiologically-Based Pharmacokinetic and Pharmacodynamic Modeling for the Inhibition of Acetylcholinesterase by Acotiamide, A Novel Gastroprokinetic Agent for the Treatment of Functional Dyspepsia, in Rat Stomach
Histomorphometric alterations of muscle soleus provoked by drawn out immobilization: experimental study with wistar lineage rats
Mechanical Feasibility of Immediate Mobilization of the Brachioradialis Muscle After Tendon Transfer
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