Over the last decade, major advances have been made in the elucidation of mechanisms involved in leukemogenesis, and this is particularly true with regard to deregulated protein tyrosine kinase (PTK) activation. This progress had led to the development of small molecules that specifically inhibit the abnormally activated kinase. The first example of such targeted therapy is imatinib-mesylate, a...

Although lysophosphatidylcholine (LPC)-mediated cellular responses are attributed to the activation of protein kinase C (PKC), relatively little is known about the upstream signaling mechanisms that regulate the activation of PKC and downstream mitogen-activated protein (MAP) kinase. LPC activated p42 MAP kinase and PKC in mesangial cells. LPC-mediated MAP kinase activation was inhibited (but n...

OBJECTIVE To describe the epithelial healing rates observed in freshly cultured rabbit corneas chemically burned with high-concentration hydrochloric acid (HCl) and sodium hydroxide (NaOH) and subsequently treated with phototherapeutic keratectomy (PTK). METHODS We obtained 126 fresh corneoscleral rims from cadaveric New Zealand white rabbits. Each cornea was exposed to 4-mm cellulose sponges...

Keratectomy. By Dimitri Azar, Roger Steinert, and Walter Stark. Philadelphia, PA: Williams and Wilkins; 1997; 214 pp. $79.00. Phototherapeutic keratectomy (PTK) has been developed to remove superficial corneal opacities and irregularities. In the foreword, Claus H. Dohlman, Professor of Ophthalmology at Harvard, whimsically asks the question, “Will a quick shave with the excimer laser solve the...

We determined whether concurrent blockage of vascular endothelial growth factor (VEGF) receptor and epidermal growth factor (EGF) receptor signaling by two novel tyrosine kinase inhibitors, PTK 787 and PKI 166, respectively, can inhibit angiogenesis and, hence, the growth and metastasis of human pancreatic carcinoma in nude mice. Highly metastatic human pancreatic carcinoma L3.6pl cells were in...

In rats, feeding can be triggered experimentally using many approaches. Included among these are (1) food deprivation and (2) acute microinjection of the neurotransmitter l-glutamate (Glu) or its receptor agonist NMDA into the lateral hypothalamic area (LHA). Under both paradigms, the NMDA receptor (NMDA-R) within the LHA appears critically involved in transferring signals encoded by Glu to sti...

Activation of the T-cell antigen receptor (TCR) results in tyrosine phosphorylation of the TCR zeta chain and other intracellular substrates. Two other T-cell integral membrane proteins, CD4 and CD8, are associated with the protein-tyrosine kinase (PTK), lck. Despite evidence that activation of this enzyme results in TCR-zeta chain phosphorylation, it has not been shown that the TCR activates l...

Chloroplast sensor kinase (CSK) is a bacterial-type sensor histidine kinase found in chloroplasts--photosynthetic plastids--in eukaryotic plants and algae. Using a yeast two-hybrid screen, we demonstrate recognition and interactions between: CSK, plastid transcription kinase (PTK), and a bacterial-type RNA polymerase sigma factor-1 (SIG-1). CSK interacts with itself, with SIG-1, and with PTK. P...

This paper describes a Security Enhanced AODV routing protocol for wireless mesh networks (SEAODV). SEAODV employs Blom’s key pre-distribution scheme to compute the pairwise transient key (PTK) through the flooding of enhanced HELLO message and subsequently uses the established PTK to distribute the group transient key (GTK). PTK and GTK are used for authenticating unicast and broadcast routing...