Plasma biological responses

FIGURE 10 Plasma profile of nafarelin acetate and biological response parameter in female Rhesus monkeys after injection with 100 mg of 55 45 lactide/glycolide microspheres. (From Ref. 118.)... 

Of the following, which is unlikely to be associated with receptors bound to plasma membranes, their interaction with ligands, and the biologic response to this interaction ... 

Calcium ions entering cells from the outside or released from internal stores trigger many biological responses (see Box 6-D). Within cells Ca2+ often accumulates in mitochondria, in the ER, or in vesicles called calciosomes.265 Release of the stored Ca2+ is induced by hormones or by nerve impulses. For example, impulses flow from the nerve endings into the muscle fibers and along the invaginations of the plasma membrane called transverse tubules (Chapter 19). There they induce release of Ca2+ from the ER. The released ions activate enzymes266 and induce contraction of the muscle fibers. In many cells, Ca2+ causes release of secreted materials, for example, neurotransmitters in the brain 267/268... 

Fig. 8.4 Decrease in plasma calcium level as a biological response for the salmon calcitonin bioavailability in fasted rats after oral administration of chitosan minitablets ( ), chitosan/ chitosan-pepsin inhibitor conjugate minitablets ( ) and thiolated chitosan/chitosan-pepsin inhibitor conjugate minitablets (A), all containing 50 pg of the peptide drug. Indicated values are the mean results from five rats S.D. (Guggi et al. 2003)...

Biological data should pertain to an aspect of biological/biochemical function that can be measured. The events could be occurring in enzymes, isolated or bound receptors, in cellular systems, or whole animals. Because there is considerable variation in biological responses, test samples should be run in duplicate or preferably triplicate, except in whole animal studies where assay conditions (e.g., plasma concentrations of a drug) preclude such measurements. 

Distributed pharmacokinetics is characterized not only by spatially dependent concentration profiles but also by dose-response relationships that become spatially dependent. For example, biological responses such as cell kill are often quantified as functions of area under the concentration-vs.-time curve (ALIC). In compartment models, response is frequently correlated with the area under the plasma-concentration-vs.-time curve, where... 

Yeung, W.K., Reilly, G.C., Matthews, A., and Yerokhin, A.L. (2013) In vitro biological response of plasma electrolytically oxidized and plasma-sprayed hydroxyapatite coatings on li-6Al-4V alloy. /. Biomed. Mater. Res. B Appl. Biomater., 101 (6), 939—949. 

The concentrations of C-reactive protein increase up to 1000 -fold in inflammatory conditions and in tissue necrosis. In addition, it can initiate reactions of agglutination, precipitation, and opsonization for phagocytosis and can activate the complement system. Other biological activities with platelets and lymphocytes have also been described, but the full biological functions of CRP have not yet been completely elucidated. Review of CRP and the acute phase response H. Gewurz el aL. Advan. Int. Med. 27, 345 -372 (1982). Review of structure and function M. B. Pepys. Bur. J. Rheumatol Inflammation S, 386-397 (1982). Book Arm. N. Y. Acad. Set 389, entitled "C-Reactive Protein and the Plasma Protein Response to Tissue Injury , I. Rushner et al, Eds. (1982) 482 pp. 

The change in biological response of the adsorbed fibrinogen molecule (conversion), is also noticeable with platelet adhesion studies. In confirmation of earlier studies of Zucker and Vroman (5), we found that, usually, less platelets adhered to areas of glass slides exposed to platelet-poor plasma for 3 min than areas exposed for 3 s. When, however, a gel-filtered platelet suspension was used in place of platelet-rich plasma, a dramatic difference in the number of platelets attached to the surface previously exposed to platelet-poor plasma for 3 s or 3 min occurred. Therefore, this more reproducible protocol was used to study not only the adhesion of platelets onto artificial surfaces but also as a probe of conversion. For this purpose we chose a series of block copolymers with controllable domain morphology (phase separation on a molecular scale) and different surface energies (wettability). Previous studies have shown that the degree of phase separation influences the interactions with blood components (6,7). 

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