A gelatinous reagent containing chloride ions, aliphatic alcohol, Fe.sup.3+ and trace amounts of selected agents is useful for detecting the pathologies of atherogenic metabolism and bilirubinemia by observation of a color change when the reagent is brought into contact with a body fluid. The reagent can be carried on a diagnostic strip or can be used for spectrometric analysis in liquid form. The reagent can be used with a second reagent containing oxammonium sulfate to identify the pathologies by measurement of the electropotential generated when a body fluid is brought into contact with both of the reagents.

The test paper for urinalysis of the present invention is made up of water-soluble paper which consists of 99-45 weight per cent of carboxymethyl cellulose and 1-55 weight per cent of wood pulp. This water-soluble paper is covered or impregnated with one or more reagents needed for urinalysis in order to form an appropriate shape of spots. The urinary test paper of the present invention can be flushed down a toilet bowl or a urinal in a flush toilet after use thereof.

An indicator (10) for detecting contact with a naturally occurring polyhydroxyaromatic skin irritant or toxin like that found in poison ivy and the like comprises a carrier (12) treated with a reactant, such as ferric nitrate which reacts with the toxin and produces a distinct color change indicative of such contact.

An ultra-lightweight, open-pore foamed cellulose material with an increased surface area, having ion exchangeable functional groups introduced in it. The cellulose material presents a three-dimensional network structure which, upon swollen, has a particle diameter of 0.8 to 12.0 mm, a mean pore diameter of 0.1 to 1.7 mm, a specific surface area of 1.0 to 10.0 m.sup.2 /g, a true density of 1.4 to 1.6 g/cm.sup.3 and a porosity of 90% or greater. The ion exchangeable functional groups, for instance, may be cationic polyethyleneimine.

A system and method for extracting a biological fluid from an organism and continuously monitoring its characteristics. The system includes a tissue interface device suitable for positioning on or about the surface of the biological membrane of the organism and a monitor and control unit coupled to the tissue interface device. The tissue interface device includes a sensor positioned in a flow path of the fluid for continuously sensing a characteristic of the biological fluid as it flows out from the one or more artificial openings formed in the biological membrane. The sensor generates a sensor signal representative thereof. The monitor and control unit electrically or optically reads the sensor to obtain a measurement of a characteristic, such as concentration of a particular analyte, of the biological fluid on a continuous basis.