Abstract: This invention relates to catheters for measuring the pressure along the length of a patient's urethra, of the kind having a closed distal end and provided at a distance from said distal end with a lateral outlet for a fluid to be fed in at a constant rate of flow through a passage arranged for connection to a measuring instrument.According to the invention, the lateral catheter outlet is formed by an annular gap extending in a plane at right angles to the longitudinal axis of the catheter and into which opens the supply passage for the fluid.Advantageously, the catheter is transversely divided into two parts constituting distal and proximal sections having mutually opposed terminal areas. These terminal areas are connected by a rigid bridging member to form the annular gap, which latter for example has a width of advantageously between 0.2 and 0.5 mm.

Abstract: Hydrophilic latex particles consisting of a homo- or co-polymer of monomers which are sparingly soluble in water, which hydrophilic latex particles can be prepared by emulsion polymerization in the presence of a water-soluble, radical-forming initiator but without an addition of an emulsifier, stabilizer or wetting agent. A process for the preparation of these hydrophilic latex particles, wherein a monomer which is sparingly soluble in water or several monomers which are sparingly soluble in water are dispersed in water and, with the exclusion of oxygen, for example in an inert atmosphere, are homo- or co-polymerized by emulsion polymerization in the presence of a water-soluble, radical-forming initiator but without any addition of an emulsifier, stabilizer or wetting agent.A diagnostic agent containing these hydrophilic latex particles as carrier and biologically and/or immunologically active substances covalently bound to this carrier either directly or via a coupling agent as a bridge.