Abstract: Hydrophilic polymeric chambers for encapsulating biologically active tissue and methods for their preparation. The tissue refers to those essential cellular components of a particular organ that is capable of receiving, modifying or secreting hormones. A device comprising such chamber and such tissue is fabricated and implanted in a living body so that said tissue is permitted normal function without being rejected by the host's immunological system. The viability of the tissue in the device is maintained by a correlation of factors including pore size and membrane thickness of the hydrophilic chamber. To maintain the viability of the tissue, the implanted device allows the inflow of essential nutrients and gases, and outflow of metabolites and products while simultaneously excluding the ingress of cellular components of the host's immunological system.

Abstract: The present invention comprises a writing implement having means to provide for illumination on the writing surface concentrically about implement contact therewith. Replaceable, translucent writing cartridges are envisioned, this as well as a translucent end piece providing an aligning socket for the light bulb. Novel pressure switch means is supplied for selectively energizing the inwardly contained light means so that light illumination will be provided proximate the point of the implement.

Abstract: A flashlight and writing implement combination wherein the device is interiorly illuminated, and ultimately conducts such illumination in either of two directions, depending upon on which end the cap of the implement is placed. The cap includes reflective means for reversing light-flow back through the light-conductive or translucent barrel, toward the end piece and to the writing tip itself, concentrically thereabout. Optionally, the cap is disposed on the reverse end, in which event the light is actuated to send illumination in the opposite direction, the device thereby serving as a flashlight. Aperture means may be provided the cap so that the usually provided clip can be depressed to actuate the pressure switch of the implement. The cap can be made of a resilient deformable plastic material so that by squeezing the same the pressure switch means of the implement may be actuated.