Handbook of experimental pharmacology
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Handb Exp Pharmacol · Jan 2008
ReviewPharmacokinetics and pharmacodynamics of GPI 15715 or fospropofol (Aquavan injection) - a water-soluble propofol prodrug.
Propofol (2,6-diisopropylphenol) is inadequably soluble in water and is therefore formulated as a lipid emulsion. This may have disadvantages when propofol is used to provide total intravenous anaesthesia or especially during long-term sedation. There has been considerable interest in the development of new propofol formulations or propofol prodrugs. ⋯ We found a significantly greater V(c), V(dss), significantly shorter alpha- and beta-half-life and a longer MRT (mean residence time) for propofol(G). The pharmacodynamic potency of propofol(G) appears to be higher than propofol when measured by EEG and clinical signs of hypnosis. In summary, GPI 15715 or fospropofol was well suited to provide anaesthesia or conscious sedation.
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Handb Exp Pharmacol · Jan 2008
ReviewAdvanced technologies and devices for inhalational anesthetic drug dosing.
Technological advances in micromechanics, optical sensing, and computing have led to innovative and reliable concepts of precise dosing and sensing of modern volatile anesthetics. Mixing of saturated desflurane flow with fresh gas flow (FGF) requires differential pressure sensing between the two circuits for precise delivery. The medical gas xenon is administered most economically in a closed circuit breathing system. ⋯ Delivery of xenon is presented, followed by a discussion of direct injection of volatile anesthetics and of a device designed to conserve anesthetic drugs. Next, innovative sensing technologies are presented for reliable control and precise metering of the delivered volatile anesthetics. Finally, we discuss the technical challenges of automatic control in low-flow and closed circuit breathing systems in anesthesia.
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Handb Exp Pharmacol · Jan 2008
ReviewCytokine, chemokine, and co-stimulatory fusion proteins for the immunotherapy of solid tumors.
This chapter describes the generation of novel reagents for the treatment of cancer using fusion proteins constructed with natural ligands of the immune system. Immunotherapy is a powerful therapeutic modality that has not been fully harnessed for the treatment of cancer. We and others have hypothesized that if the proper immunoregulatory ligands can be targeted to the tumor, an effective immune response can be mounted to treat both established primary tumors and distant metastatic lesions. ⋯ When used alone, both forms of costimulatory fusion proteins were found to produce in a s dose-dependent manner, complete regression of murine solid tumors. Evidence is presented to show that Treg cells play an important role in suppressing antitumor immunity since the deletion of these cells, when used in combination with LEC or costimulatory fusion proteins, produced profound and effective treatment with sustained memory. It is hoped that these data will further the preclinical development of soluble Fc and antibody based fusion proteins fro the immunotherapy of cancer.
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We do not know how general anesthetics cause their desired effects. Contrary to what has been thought until relatively recently, the clinical state of anesthesia consists of multiple components that are mediated via interaction of the anesthetic drugs with different targets on the molecular-cellular, the network, and the structural-anatomical levels. The molecular targets by which some of these drugs induce the different components of "anesthesia" may be rather specific: discrete mutations of single amino acids in specific proteins profoundly affect the ability of certain anesthetics to achieve specific endpoints. ⋯ The CNS appears to be susceptible to anesthetic neurotoxicity primarily at the extremes of ages, possibly via different pathways: in the neonate, during the period of most intense synaptogenesis, anesthetics can induce excessive apoptosis; in the aging CNS subtle cognitive dysfunction can persist long after clearance of the drug, and processes reminiscent of neurodegenerative disorders may be accelerated (Eckenhoff et al. 2004). At all ages, anesthetics affect gene expression-regulating protein synthesis in poorly understood ways. While it seems reasonable to assume that the vast majority of our patients completely restore homeostasis after general anesthesia, it is also time to acknowledge that exposure to these drugs has more profound and longer lasting effects on the brain than heretofore imagined.
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Recent interest in the use of low-flow or closed circuit anesthesia has rekindled interest in the pharmacokinetics of inhaled anesthetics. The kinetic properties of inhaled anesthetics are most often modeled by physiologic models because of the abundant information that is available on tissue solubilities and organ perfusion. These models are intuitively attractive because they can be easily understood in terms of the underlying anatomy and physiology. ⋯ Finally, we will reintroduce the concept of the general anesthetic equation to explain why the use of low-flow or closed circuit anesthesia has rekindled interest in the modeling of pharmacokinetics of inhaled anesthetics. Clinical applications of some of these models are reviewed. A basic understanding of the circle system is required, and will be provided in the introduction.