Protein tyrosine kinases (PTK) are key enzymes of mammalian signal transduction. For the fidelity of signal transduction, each PTK phosphorylates only one or a few proteins on specific Tyr residues. Substrate specificity is thought to be mediated by PTK-substrate docking interactions and recognition of the phosphorylation site sequence by the kinase active site. However, a substrate-docking sit...

Chicken blastodermal cells (CBC) from Stage X embryos, which were isolated from newly laid, fertile, unincubated eggs, are pluripotent cells and can produce somatic and germline chimeras when injected into recipient stage X embryos. The CBC retain their pluripotential ability for up to 7 d in vitro. The molecular mechanisms that control proliferation and differentiation of CBC are largely unkno...

The aim of the present study was to observe whether protein tyrosine kinase (PTK) within the nucleus tractus solitarius (NTS) was involved in the regulation of ventilatory responses of peripheral chemoreflex. The experiments were performed on anesthetized, immobilized and artificially ventilated rabbits. Peripheral chemoreflex was elicited by ventilating the animal with 10% O2-balance 90% N2. C...

PURPOSE To compare the visual, refractive, keratometric, topographic, and pachymetric outcomes of corneal collagen cross-linking (CXL) for progressive keratoconus following epithelial removal by transepithelial phototherapeutic keratectomy (PTK) or manual debridement. METHODS In this analysis, 339 eyes (78% male, 22% female) that had undergone CXL following manual epithelial debridement (n = ...

ptk (phototherapeutic keratectomy) is the use of laser in corneal diseases. we can replace ptk for many other invasive procedures. the objective of this study is the assessment of this procedure in several cases in our practice. this investigation was a retrospective study, which was conducted based on comparison of 11 eyes with corneal eschars, induced by recurrent corneal erosions, pterygium ...

Halting tumor growth by interfering with tumor-induced angiogenesis is an attractive therapeutic approach. Such treatments include humanized antibodies blocking the activity of vascular endothelial growth factor (VEGF)-A (bevacizumab), soluble VEGF receptor (VEGFR) constructs (VEGF-Trap), or small-molecule inhibitors of VEGFR signaling, including PTK787/ZK222584 (PTK/ZK), sorafenib, and sunitin...

BACKGROUND The aim of this study was to determine whether postal testing kits (PTKs) or patient-delivered partner therapy (PDPT) for partners of women with Chlamydia trachomatis reduce re-infection rates in women, compared with partner notification by patient referral. METHODS Three hundred and thirty women testing positive for chlamydia, at clinics for genitourinary medicine, family planning...

We investigated the structural requirements for bombesin (BB)-like peptides to stimulate amylase secretion in rat pancreatic acini and examined the responsible intracellular signal transduction pathways. The tetradecapeptide BB-(1-14) was a full agonist, whereas the heptapeptide BB-(8-14) did not evoke amylase secretion. The mammalian BB analog neuromedin C decapeptide [NMC-(5-14)] was as poten...