Current practices in nutrition management and disease incidence of common marmosets (Callithrix jacchus).

Background: A survey was developed to characterize disease incidence, common pathology lesions, environmental characteristics, and nutrition programs within captive research marmoset colonies.

Methods: Seventeen research facilities completed the electronic survey.

Results: Nutritional management programs varied amongst research institutions housing marmosets; eight primary base diets were reported.

Trial-to-trial, uncertainty-based adjustment of decision boundaries in visual categorization.

Categorization is a cornerstone of perception and cognition. Computationally, categorization amounts to applying decision boundaries in the space of stimulus features. We designed a visual categorization task in which optimal performance requires observers to incorporate trial-to-trial knowledge of the level of sensory uncertainty when setting their decision boundaries.

Phosphotyrosyl peptides block Stat3-mediated DNA binding activity, gene regulation, and cell transformation.

Signal transducers and activators of transcription (STATs) comprise a family of cytoplasmic signaling proteins that participates in normal cellular responses to cytokines and growth factors. Frequently, however, constitutive activation of certain STAT family members, particularly Stat3, has accompanied a wide variety of human malignancies. To identify small molecule inhibitors of Stat3, we investigated the ability of the Stat3 SH2 domain-binding peptide, PY*LKTK (where Y* represents phosphotyrosine), to disrupt Stat3 activity in vitro.

Constitutive activation of Stat3 by the Src and JAK tyrosine kinases participates in growth regulation of human breast carcinoma cells.

Constitutive activation of signal transducer and activator of transcription (STAT) proteins has been detected in a wide variety of human primary tumor specimens and tumor cell lines including blood malignancies, head and neck cancer, and breast cancer. We have previously demonstrated a high frequency of Stat3 DNA-binding activity that is constitutively-induced by an unknown mechanism in human breast cancer cell lines possessing elevated EGF receptor (EGF-R) and c-Src kinase activities. Using tyrosine kinase selective inhibitors, we show here that Src and JAK family tyrosine kinases cooperate to mediate constitutive Stat3 activation in the absence of EGF stimulation in model human breast cancer cell lines.

Accessibility of the c-Src SH2-domain for binding is increased during mitosis.

The Src homology 2 (SH2) region is a noncatalytic domain of Src-family tyrosine kinases and other proteins which participants in inter- and intramolecular interactions of tyrosine-phosphorylated proteins. A synthetic peptide modeled on the c-Src carboxyl terminus, which contains phosphotyrosine at position 527, binds recombinant SH2 and the SH2-domain of c-Src which lacks phosphotyrosine 527. Unphosphorylated peptide does not bind detectably.