Expression systems classification

Receptors can be most reliably subclassified and defined on the basis of antagonist affinities, whereas data obtained with agonists are considered much less useful since intrinsic activity and potency have been found to be cell and tissue dependent. Information on receptor-effector mechanisms that reflect the molecular signaling properties of the receptor provides another tier for receptor classification, although transduction mechanisms for novel receptors may be unclear and subject to controversy. Furthermore, the use of heterologous cellular expression systems for the study of recombinant receptors has revealed... 

Classification of the defects of naturally occurring mutant human V2 receptors can be based on a scheme similar to that used for the LDL receptor. Mutations have been grouped according to the function and subcellular localization of the mutant protein whose cDNA has been transiently transfected in a heterologous expression system [133]. Using this classification, type 1 mutant V2 receptors reach the cell surface but display impaired ligand binding... 

Kenakin, T.P., 1996. The classification of seven transmembrane receptors in recombinant expression systems. Pharmacol. Rev. 48, 413-463. 

However, in the foregoing systems, the predominant mechanism allows easy mathematical description. In practice, the dominant mechanism for release will overshadow other processes enough to allow classification as either dissolution rate-limited or diffusion-controlled. Bioerodible devices, however, constitute a group of systems for which mathematical descriptions of release characteristics can be quite complex. Characteristics of this type of system are listed in Table 7. A typical system is shown in Fig. 8. The mechanism of release from simple erodible slabs, cylinders, and spheres has been described [36], A simple expression describing release from all three of these erodible devices is... 

The severity of pelvic pain and the incidence of infertility are not related to the localization of the lesions or to the stage of the disease (Gruppo Ital-iano per lo Studio dell Endometriosi 2001), as categorized according to the revised American Fertility Society (r-AFS) guidelines (American Fertility Society 1985). In fact, the r-AFS classification system is inadequate to express the severity of the symptomatology because it does not reflect the disease in terms of cellular mass or activity. 

Mechanistic classification system, 13 441 Mechanistic kinetic expressions, 10 85-88 Mechanistic organic chemistry, high... 

Epilepsy is a chronic often progressive disorder of the central nervous system (CNS). Periodic and unpredictable epileptic seizures caused by the abnormal electrical discharge of neurones in various anatomic structures of the CNS is the characteristic feature. This is an approximate definition based on international classifications of seizures and syndromes which take into account the extremely variable clinical and electroencephalographic expression of the disease. The annual incidence of epilepsy is an estimated 20-70 cases per 100,000 inhabitants with a prevalence of 0.4-0.8%. Globally, incidence is higher during childhood, remaining rather stable... 

The dimension of a space equals the number of elements in a basis, which is defined as a set of elements such that every element in the space is equal to a unique linear combination of them. Therefore, P steady-state mechanisms can be chosen in terms of which all others can be uniquely expressed. This gives us a unique way to symbolize each steady-state mechanism and its overall reaction, but it does not provide a classification system for them which is valid from a chemical viewpoint, because the choice of a basis is arbitrary and is not dictated, in general, by any consideration of chemistry. A classification system for mechanisms is our next topic. 

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