Abstract: Two previously undescribed human cdc25 genes, designated cdc25 A and cdc25 B, which have been shown to have an endogenous tyrosine phosphatase activity that can be specifically activated by B-type cyclin, in the complete absence of cdc2.As a result of the work described herein, new approaches to regulating the cell cycle in eukaryotic cells and, particularly, to regulating the activity of tyrosine specific phosphatases which play a key role in the cell cycle are available. Applicant's invention relates to methods of regulating the cell cycle and, specifically, to regulating activation of cdc2-kinase, through alteration of the activity and/or levels of tyrosine phosphatases, particularly cdc25 phosphatase, and B-type cyclin or through alteration of the interaction of components of MPF, particularly the association of cdc25 with cyclin, cdc2 or the cdc2/cyclin B complex. The present invention also relates to agents or compositions useful in the method of regulating (inhibiting or enhancing) the cell cycle.

Abstract: Methods and systems are disclosed for encapsulating viable cells which produce biologically-active factors. The cells are encapsulated within a semipermeable, polymeric membrane by co-extruding an aqueous cell suspension and a polymeric solution through a common port to form a tubular extrudate having a polymeric outer coating which encapsulates the cell suspension. For example, the cell suspension and the polymeric solution can be extruded through a common extrusion port having at least two concentric bores, such that the cell suspension is extruded through the inner bore and the polymeric solution is extruded through the outer bore. The polymeric solution coagulates to form an outer coating. As the outer coating is formed, the ends of the tubular extrudate can be sealed to form a cell capsule. In one embodiment, the tubular extrudate is sealed at intervals to define separate cell compartments connected by polymeric links.

Abstract: Living cells such as animal cells which produce biologically active factors are encapsulated within a semipermeable, polymeric membrane such as polyacrylate by co-extruding an aqueous cell suspension and a polymeric solution through a common port having at least one concentric bores to form a tubular extrudate having a polymeric membrane which encapsulates the cell suspension. The cell suspension is extruded through an inner bore and the polymeric solution is extruded through an outer bore while a pressure differential is maintained between the cell suspension and the polymeric solution to impede solvent diffusion from the polymeric solution into the cell suspension. The polymeric solution coagulates to form an outer coating or membrane as the polymeric solution and the cell suspension are extruded through the extrusion port. As the outer membrane is formed, the ends of the tubular extrudate are sealed to form a cell capsule.

Abstract: Novel 6-pyridyl substituted pyrimidine derivatives are disclosed for use as antiviral agents, particularly for the treatment of retroviral infections such as HIV infections and related disorders, as well as for use in anti-cancer therapies to improve the efficacy of anti-cancer therapeutics. These compounds and their pharmacologically acceptable salts operate to disrupt viral replication an exhibit lower cell toxicity, thereby providing more efficient agents for use alone or in conjunction with other chemical or biological agents to provide prolonged antiviral therapy. In addition, the compounds can be used to increase the efficacy of anti-cancer therapeutics including 5-fluropyrimidines such as 5-fluorouracil, thereby reducing the dosage requirement of the therapeutic in anti-cancer therapies so as to decrease toxic effects to the host.

Abstract: Systems are disclosed for forming an extrudate. The systems include an extrusion head assembly having at least a first inner bore and a second outer bore, a coagulant solution supply and a polymeric casting solution supply. The coagulant supply provides coagulant to the inner bore of the extrusion head assembly, and the polymeric casting solution supply provides a casting solution to the outer bore. Using this system, the coagulant and polymeric solution are coextruded to form an extrudate having a desired configuration. The present invention further includes a rapid action valve controlling at least one of the coagulant or polymer supplies.