Catheters; Catheters and parts and fittings therefor; Intracardiac catheter; Medical and surgical catheters; Medical apparatus and instruments for treating cardiovascular disease; Medical apparatus, namely, marking pens for use in surgical procedures; Medical device for accessing subcutaneous structures of the human body for the purpose of administering medical treatment; Medical device for percutaneous intraluminal emplacement of coronary bypass grafts; Medical devices and apparatus, namely, medical guidewires and parts and fittings therefor; Medical devices to treat intravascular sites; Medical devices, namely, surgical devices that facilitate the identification, separation or ablation of biologic tissues; Medical electrodes; Medical guidewires; Medical guidewires and parts and fittings therefor