The INK4a/ARF locus and melanoma.

Inactivation of the INK4a/ARF (or CDKN2a) locus is a common and critical genetic event in the development of human and mouse melanoma. This locus engages the Rb and p53 tumor suppressor pathways through its capacity to encode two distinct gene products, p16(INK4a) and p14(ARF). This review highlights the body of evidence supporting a role for both p16(INK4a) and p14(ARF) in the suppression of melanoma, and speculates as to why this locus is preferentially targeted in this tumor type. In addition, the potential importance of these two pathways in mediating UV-induced melanoma genesis will be addressed via genetic and molecular evidence in the mouse.

Identity formation as reflected in the acquisition of person pronouns.

Psychoanalytic theory on identity formation during rapprochement is enriched by considering psycholinguistic findings on person-pronoun acquisition. Pronouns such as I and you have often been employed by psychoanalysts as behavioral markers of the intrapsychic concepts of self and other and used to make inferences about the representation of these concepts in children as young as 18 months. Psycholinguistic research, however, reveals two sets of facts which such inferences overlook. First, knowledge of person pronouns, as of other words, is a developmental phenomenon. In children under 22-24 months, prior to the resolution of the rapprochement crisis, pronoun usage is stereotypic and wedded to context. Testing in diverse situations shows that this child has no consistent interpretation of these words. Second, and more important, when children acquire mature understanding of these words at the close of that rapproachement subphase, the knowledge reflected is somewhat different than psychoanalysts have held. Psycholinguistics shows that the meanings children express through person pronouns involve concepts of conversational role where first person indicates speaker, second person, person addressed, and third person, other (third) parties. It is argued that the psycholinguistic and psychoanalytic views on person-pronoun acquisition can be reconciled in the view that this developmental milestone is one of coordinating the expression of concepts of self and other with concepts of conversational roles. For psychoanalysts, then, person pronoun acquisition becomes a signal not only of the child's appreciation of the separateness of self and other, but also of their interrelatedness through the participation of self and other in conversational roles. The cognitive representation of these roles can be considered to function as an early ego identification, facilitating children's progress from the dyad to the larger social milieu.