Mode of administration

PTH has a dual effect on bone cells, depending on the temporal mode of administration given intermittently, PTH stimulates osteoblast activity and leads to substantial increases in bone density. In contrast, when given (or secreted) continuously, PTH stimulates osteoclast-mediated bone resorption and suppresses osteoblast activity. Further to its direct effects on bone cells, PTH also enhances renal calcium re-absorption and phosphate clearance, as well as renal synthesis of 1,25-dihydroxy vitamin D. Both PTH and 1,25-dihydroxyvitamin D act synergistically on bone to increase serum calcium levels and are closely involved in the regulation of the calcium/phosphate balance. The anabolic effects of PTH on osteoblasts are probably both direct and indirect via growth factors such as IGF-1 and TGF 3. The multiple signal transduction... 

Retinoids. Table 1 Indications and mode of administration of commercially available retinoids in dermatological therapy... 

Generic name Chemical structure Mode of administration Principal indication Other indications... 

Cannabinoids are highly lipophilic compounds making bioavailabihty very dependent on the formulation and the mode of administration. Cannabinoid occurrence in the plant is predominantly in the form of the carboxyhc acids, which are pharmacologically totally different and rather unstable, decarboxy-lating over time to their active neutral form. The carboxyhc acids, although not active at the CB receptor, nevertheless add to the overall effect as they possess antibiotic and anti-inflammatory effects. 

This model is representative for the conditions described in the previous section, except for the mode of administration which can be oral, rectal or parenteral by means of injection into muscle, fat, under the skin, etc. (Fig. 39.7). In addition to the central plasma compartment, the model involves an absorption compartment to which the drug is rapidly delivered. This may be to the gut in the case of tablets, syrups and suppositories or into adipose, muscle or skin tissues in the case of injections. The transport from the absorption site to the central compartment is assumed to be one-way and governed by the transfer constant (Fig. 39.7a). The linear differential model for this problem can be defined in the following way ... 

T. Teorell, Kinetics of distribution of substances administered to the body. 1. The extravascular modes of administration. Arch. Int. Pharmacodyn., 57 (1937) 205-225. II. The intravascular modes of administration. Arch. Int. Pharmacodyn., 57 (1937) 226-240. 

Acrolein degrades quickly in soils and in plant tissues, regardless of mode of administration. Most terrestrial crop plants easily tolerate 25,000 pg acrolein/L of irrigation water, and some can tolerate 70,000 to 80,000 pg/L without adverse effects. Terrestrial plants were adversely affected at atmospheric concentrations of 500 pg acrolein/L air, but this concentration exceeds the recommended value of 110 pg/L (0.25 mg/m3) air for protection of human health in occupational settings. 

Mode of Administration, Units, Organism, Formulations, and Other Variables Dose Effect Reference"... 

Table 17.7 Diflubenzuron Effects on Selected Mammals Species, Mode of Administration, Dose,...

Mode of Administration Receptor Mediation Immune Function Activity... 

M. Bialer, A. Rubinstein, Pharmacokinetics of Valpromide in Dogs after Various Modes of Administration , Biopharm. Drug Dispos. 1984, J, 177-183. 

Cleavage of the N-C bond is also relevant in the metabolism of a few CAS agents. Thus, metabolism of the potential hypnotic N3-phenacyluridine (11.21) occurred by two major routes in mice carbonyl reduction was the predominant reaction, but A-deribosylation to yield A3-phenacyluracil was also important [43]. Given the intraperitoneal (i.p) mode of administration, it is doubtful that intestinal bacteria were involved. 

Current efforts in vaccine development have predominantly utilized clade B isolates, which represent the subtype in North America and Western Europe. There is also an increased interest in the development of clade A and C vaccines for the expanding pandemic in Asia and sub-Saharan Africa. A concern in fhe clade-specific vaccine strategy is the potential inability to produce large amounts of vaccine specific for distinct clades. This leaves open the question of specific vs. cross-clade effectiveness. Choice of immunogen(s), adjuvant, dose, and mode of administration are also additional variables that must be addressed in candidate vaccine research. 

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