Abstract: A ring element (10) attaches to a length of tubing (12) to prevent contamination at a site (24) through which a portion of the length of tubing (12) extends. A resilient material having a first end (14) and a second end (16) is provided capable of mating to form a hollow, cylindrical shell (10). An electrically conductive material is provided on a surface of the resilient material. In a preferred embodiment, the conductive material includes silver. The ring element (10) may be placed on a tube (12) to prevent contamination at a site (24) through which a tube (12) is secured. The ring element (10) is connected to the tube (12) at the site (24) of injection of the tube (12) wherein the ring element (10) is capable of removal without removal of the tube (12) from the site (24). The ring element (10) is particularly adaptable for a transfer set connectable to a peritoneal cavity and insertable at a site (24) for, for example, peritoneal dialysis.

Abstract: An improved peritoneal dialysis solution and methods of administering same to a patient are provided. Pursuant to the present invention, the sodium concentration in the solution is decreased thus causing sodium to be transported from the circulation to the peritoneal cavity. This provides for an improved ultrafiltration profile for the same initial osmolality when compared to standard solutions. Also, the same ultrafiltration profile as standard solutions can be achieved with lower initial osmolalities.

Abstract: Systems and methods for peritoneal dialysis establish flow communication between a patient's peritoneal cavity and a drain through a pump chamber having generally vertically spaced upper and lower regions andt a diaphragm. The systems and methods operate the pump chamber, with the upper and lower regions oriented generally vertically, by applying fluid pressure to the diaphragm. The systems and methods direct liquid to the patient's peritoneal cavity only from the lower region of the pump chamber. In this way, the improved systems and methods collect air in the upper region of the vertically oriented pump chamber, while isolating the patient's peritoneal cavity from air in the pump chamber.

Abstract: An improved peritoneal dialysis solution comprising an osmotic agent having at least one amino acid, and a method of administering same to a patient are provided. Pursuant to the present invention, the sodium concentration in the solution is decreased thus causing sodium to be transported from the circulation to the peritoneal cavity. This provides for an improved ultrafiltration profile that is, more volume over a longer period of time, for the same initial osmolality when compared to standard solutions. Also, the same ultrafiltration profile as standard solutions can be achieved with lower initial osmolalities.

Abstract: An improved adaptor and protector for same which is removably sealing an opening of the adaptor located at an end of a tubular member. The adaptor has a longitudinal passageway for receiving a cannula. An upper end of the adaptor has an interior diameter defining a first end of the passageway for receiving the cannula. A lower end of the adaptor has an interior diameter defining a second end of the passageway adapted for receiving an injection site wherein the diameter of the first end is larger than the diameter at the second end. A middle portion intermediate the first end and the second end has a tapering interior diameter for directing the cannula to the injection site and further having an exterior surface with gripping surfaces. The tapering interior diameter of the middle portion of the adaptor includes guiding members to direct the cannula or other injection devices. The adaptor may also be provided with a protector removably sealing an opening located at an end of the adaptor.

Abstract: The present invention provides improved methods for manufacturing solutions including medical solutions. To this end, in an embodiment, a method for preparing a medical solution is provided comprising the steps of: placing a solution in a gas permeable container; and allowing carbon dioxide to permeate through the container until a desired pH is achieved.

Abstract: Peritoneal dialysis solutions are specially formulated for use during and immediately after an episode of peritonitis. The solutions include one or more additives to minimize the injury and physiological effects that peritonitis can cause. One additive is a mixture of amino acids sufficient to maintain a positive nitrogen balance, at least one of the amino acids being present in a dipeptide form. Another additive is a compound that scavenges free radicals generated by peritoneal macrophages activated by the peritonitis. Another additive is chondroitin sulfate that changes the permeability of the peritoneal membrane during subsequent dialysis using solutions free of chondroitin sulfate. Another additive is the degradation products of hyaluronic acid to enhance the regeneration of the peritoneal mesothelium without fibrosis.

Abstract: A peritoneal dialysis solution and method of administering same to a patient are provided wherein the sodium concentration in the solution is decreased thus causing sodium to be transported from the circulation to the peritoneal cavity. This provides for an improved ultrafiltration profile (more volume over a longer period of time) for the same initial osmolality when compared to standard solutions. Also, the same ultrafiltration profile as standard solutions can be achieved with lower initial osmolalities. A reduced amount of osmotic agent can be used to achieve equivalent ultrafiltration.

Abstract: A connector assembly, preferably for medical use, is provided having a key component and a lid lock component to provide fluid communication between a fluid source and a destination such as a patient. The lid lock component includes a removably lockable lid. The lid is held closed in a locked position by stops located on at least one flexible arm integrally formed and selectively displaceable in the lid lock component. The lid is forced open by a longitudinal key within the key component. The key spreads the flexible arms so that the formerly locked lid is capable of passing through an opening created between the flexible arms to clear the stops. The lid is converted into a position parallel to the length of the lid lock component to provide fluid communication between tubing connected to the lid lock component. The connector assembly can be used for dialysis and the like.

Abstract: Disclosed are methods that achieve i) site-directed delivery, ii) in situ amplification, and iii) sustained expression of an exogenous gene product within renal glomeruli. An exogenous gene, E. coli .beta.-galactosidase, was introduced into cultured rat mesangial cells using a replication-defective retrovirus, and stable infectants were administered to a rat kidney via the renal artery. In the injected kidney, the engineered, cultured mesangial cells populated 40% of glomeruli site-specifically. The gene product was detected throughout a 14-week period of observation. In an alternative method, engineered, cultured mesangial cells were injected into a kidney subjected to an antibody that induces mesangiolysis followed by mesangial regeneration. Under these conditions, expression of .beta.-galactosidase was dramatically amplified in situ, and high level expression continued for at least 8 weeks.

Abstract: A system and method is provided which substantially eliminates the effect of air entrapped in tubing for delivering a liquid from a container. The inner diameter of the tubing is selected such that the gravitational force of the liquid from the container is greater than the surface tension of the liquid. A release agent may be used as a coating layer on the interior wall in addition to or alternatively from an expanded diameter.

Abstract: A multiple chamber container for mixing and administering a plurality of products. The container has at least two chambers separated by a seal line. A frangible connector is situated between the two chambers for mixing the products contained within the chambers as desired. Each chamber has at least one port for filling of product into the chamber. The ports are located on the same exterior side of the container such that the chambers can be filled without folding the bag and by using existing filling equipment.

Abstract: A connector assembly is provided having a male component (12) and a female component (10) to provide fluid communication between a fluid source and a destination such as a patient. The female component (10) includes a door (28) rotatable about a hinge (30). The door (28) is forced open by a longitudinal member (34) within the male component (12). The door (28) is converted into a position parallel to the length of the female component (10) providing fluid communication between a tubing (36) extending into the female component (10). A sleeve (44) is further provided to permit and to prevent fluid flow through a tubing by rotation of the sleeve (44) resulting in compression and expansion of longitudinal members (46) within the sleeve (44) and thereby the tubing.

Abstract: The invention provides dual-skinned membranes useful as one way or rectifying membranes which reduce back filtration of solute molecules in dialysis and which improve nutrient supply and product recovery in membrane bioreactors. The membranes are dual-skinned polymeric materials preferably in the form of hollow fibers. The membranes have skins of polymer on the opposite sides with differing permeability to solutes and sieving coefficient characteristics. The skin on each side have pores that are invisible at 10,000 times magnification, the microporous structure between said skins contains pores capable of retaining solutes in a molecular weight range of about 5000 to 200000 in an increased concentration between the interior and the exterior skins. Improved dialysis devices are formed by using bundles of the hollow fiber membranes as a dialysis means having rectifying properties.

Abstract: An improved on-line real time hemodialysis monitoring system for hemodialysis treatment. The hemodialysis monitoring system quantitates the rate and amount of a constituent, such as urea, removed during the hemodialysis treatment by measuring the constituent concentrations as a function of time in the spent dialysate effluent from a hemodialysis machine. A quantity of the spent dialysate effluent is removed from the dialysate effluent waste line periodically for testing. A urea concentration time profile can be analyzed to determined the urea removal, KT/V, URR, SRI and normalized protein catabolic rate (nPCR) indices. The hemodialysis monitoring system preferably can obtain a dialysate sample equilibrated with the blood prior to the start of a hemodialysis treatment. The hemodialysis monitoring system includes a two pool analysis for taking into account the constituent concentration differences in the extracellular and intracellular spaces in the hemodialysis patient during the hemodialysis treatment.

Abstract: A system and method using same are provided for determining the optimum operating conditions of a dialysis process that yields the highest whole body dialysis clearance. The system varies a parameter that effects dialysis efficiency during part of a dialysis run. The system then measures a metabolite concentration in an outflow dialysate. The system develops a metabolite concentration profile as a function of the varied parameter. Based on these measurements, the system correlates the metabolite concentration measurements to determine the optimum parameter setting that yields the maximum metabolite concentration.

Abstract: An improved adaptor and protector for same which is removably sealing an opening of the adaptor located at an end of a tubular member. The adaptor has a longitudinal passageway for receiving a cannula. An upper end of the adaptor has an interior diameter defining a first end of the passageway for receiving the cannula. A lower end of the adaptor has an interior diameter defining a second end of the passageway adapted for receiving an injection site wherein the diameter of the first end is larger than the diameter at the second end. A middle portion intermediate the first end and the second end has a tapering interior diameter for directing the cannula to the injection site and further having an exterior surface with gripping surfaces. The tapering interior diameter of the middle portion of the adaptor includes guiding members to direct the cannula or other injection devices. The adaptor may also be provided with a protector removably sealing an opening located at an end of the adaptor.

Abstract: Dual-skinned membranes are provided useful as one-way or rectifying membranes which reduce back filtration of solute molecules in dialysis and which improve nutrient supply and product recovery in membrane bioreactors. The membranes are dual-skinned polymeric materials preferably in the form of hollow fibers. The membranes have skins of polymer on the opposite sides with differing permeability to solutes and sieving coefficient characteristics. The skin on each side have pores that are invisible at 10,000 times magnification. A microporous structure between the skins contains pores capable of retaining solutes in a molecular weight range of about 5000 to 200,000 in an increased concentration between the interior and the exterior skins. Improved dialysis devices are formed by using bundles of the hollow fiber membranes as a dialysis member having rectifying properties.

Abstract: Peritoneal dialysis systems and methods move liquid using a pump chamber that is operated in response to pneumatic pressure variations applied by a pump actuator. The systems and methods periodically measure air pressures in the actuator and an associated reference air chamber and derive from these a measurement of liquid volume moved through the pump chamber. The systems and methods minimize derivation errors by compensating for temperature differences among the pump chamber; the pump actuator; and the reference chamber.

Abstract: A method of making a peelable tube assembly (76,80,84,88) having a plurality of adjacent tube portions (62) joined by intermittent breakable webs (72) of plastic allowing the individual portions (62) to be peeled from the tube assembly, including providing a plurality of plastic tube portions (62) each having a tube wall (66) defining a flow passage (70). The tube portions (62) are aligned adjacent to one another in a die assembly (12) having compression channels (30). Narrow confined flow chambers (32) are defined between adjacent portions (62) of the tube walls (66), and between the ends of the tube walls (66). The tube portions (62) are radially compressed without occluding the flow passage (70). Small compressed portions of the tube walls (66) proximate the flow chambers (32) are heated and plasticized.