RESUMO
Of the three classes of true phosphoinositide (PI) 3-kinases, the class II subdivision, which consists of three isoforms, PI3K-C2alpha, PI3K-C2beta and PI3K-C2gamma, is the least well understood. There are a number of reasons for this. This class of PI 3-kinase was identified exclusively by PCR and homology cloning approaches and not on the basis of cellular function. Like class I PI 3-kinases, class II PI 3-kinases are activated by diverse receptor types. To complicate the elucidation of class II PI 3-kinase function further, their in vitro substrate specificity is intermediate between the receptor activated class I PI 3-kinases and the housekeeping class III PI 3-kinase. The class II PI 3-kinases are inhibited by the two commonly used PI 3-kinase family selective inhibitors, wortmannin and LY294002, and there are no widely available, specific inhibitors for the individual classes or isoforms. Here the current state of understanding of class II PI 3-kinase function is reviewed, followed by an appraisal as to whether there is enough evidence to suggest that pharmaceutical companies, who are currently targeting the class I PI 3-kinases in an attempt to generate anticancer agents, should also consider targeting the class II PI 3-kinases.
Assuntos
Proteínas de Neoplasias/fisiologia , Neoplasias/enzimologia , Fosfatidilinositol 3-Quinases/fisiologia , Movimento Celular , Sobrevivência Celular , Classe I de Fosfatidilinositol 3-Quinases , Classe II de Fosfatidilinositol 3-Quinases , Ativação Enzimática , Humanos , Transdução de Sinais , Especificidade por SubstratoRESUMO
In reviewing the literature on twin separation, the authors argue that achieving a "relational shift" (the ability to separate yet retain feelings of closeness), may be problematic for this sibling group. A descriptive communication framework is presented using the concepts of relational redefinition and types of verbal and nonverbal codes. Implications are presented for twins developing third-party relationships, inseparable twins, therapy, and research.
Assuntos
Relações entre Irmãos , Gêmeos/psicologia , Comunicação , Dependência Psicológica , Dominação-Subordinação , Pesar , Humanos , Individuação , Relações Interpessoais , Apego ao Objeto , Psicoterapia , PesquisaAssuntos
Doença Crônica/psicologia , Pessoas com Deficiência , Relações entre Irmãos , Adaptação Psicológica , Criança , Emoções , Família , Terapia Familiar , Humanos , Relações Pais-Filho , Pesquisa , RiscoRESUMO
While societal myths popularize the notion that twins are happy in their twinship, in reality there is a great deal of ambivalance. Characteristic psychological disturbances occur when twins who function as one unit separate in adulthood. Short-term aand long-term problems are discussed, as well as strategies for intervention and prevention.
