der die It/~morrhoiden bereits im 18. Jahrhundert als ,,traubenfSrmig, maschige Geschwfilste im Zusammenhang mit Arterien" bezeichnete, und BARDE~TI~EUEI~ (1860), tier in seiner Operationslehre ausffihrt, L~ D~A~r habe sich entschieden geirrt, wenn er angab, ,,dag sie (die H/~morrhoiden) mit den Arterien zusammenhingen".Sehen wir einmal yon L~ D~AN ab, so findet man seit alters her im Schrifttum bis zum heutigen Tage die einhellige Meinung, die H~mor-rhoiden seien ,,Krampfadern", d.h. dysplastische Vsnenkonvolute des unteren Enddarms. Nur MILES (1919) stellte lest --ohne indessen auf das Wesen der tt/~morrhoiden einzugehen --dab sie in Abh~ngigkei$ yon den drei End/s der A. rectalis cranialis entwickelt werden. Diese Arterie verl~uft bekanntlich zun/ichst in dem am Promontorium fixierten Meso des Colon pelvinum, das sehr erhebliche Variet/~ten in bezug auf seine L/~nge aufweist, und zieht dann retrorectal innerhalb der dorsalen Grenzlamelle abw/irts. Etwa im Bereich des 3. Sacralwirbels bzw. in HShe der Kohlrauschschen Falte, teilt sie sich in einen linken und in einen rechten Ast. Letzterer gabelt sich meist nochmals, so dag in der Regel drei Hauptarterien die ,,Regio haemorrhoidalis" an der Linea * tterrn Prof. Dr. L. Z~XSC~WERDT zum 60. Geburtstag gewidmet.

Among the joint and muscle pumps that are hemodynamically active and, in particular, bring about venous return in the lower limb, the so-called ankle pump is of paramount importance. The basic anatomical relationship of the talocrural joint to the venous network around the ankle is reviewed. Duplex sonographic measurement of the rate of blood flow in the great saphenous vein at the saphenous opening, at rest and during active and passive movements at the ankle joint, shows that such movements have an important effect on the rate of flow through the adjacent veins. Passive movement of the foot relative to the leg was brought about by a newly developed apparatus that can be either pneumatically or electrically operated. The action of the ankle pump against venous stasis, the arthrogenic congestive syndrome, and chronic venous insufficiency has demonstrated the prophylactic importance of this physiological mechanism. It can, when necessary, be replaced by an appropriately designed apparatus.

Streptozotocin diabetes in the minipig constitutes an outstanding model for the study of diabetic angiopathies. Changes which are classified as macroangiopathy are evident after 6 months, while the first changes indicative of microangiopathy appear already after about 18 months. The degree of pronouncement of the microangiopathy depends on the duration and severity of the induced diabetes. These results constitute a cogent argument in favour of the "metabolic theory" of the development of diabetic microangiopathy.

Quite unrelated diseases affecting different organs can lead to the appearance of abnormal collagen fibrils, which may be due to genetic disorders, transformation of mesenchyme cells, increased collagen synthesis or a change in the ground-substance. The simultaneous appearance of abnormal collagen fibrils and matrix vesicles containing lysosomal enzymes in the majority of our electron photomicrographs suggests an alteration in the ground-substance as a main cause of non-hereditary collagen dysplasia.

The effect of diatrizoate, ioxitalamate, metrizamide, and ioxaglate on the aortic endothelium of the rat was investigated using transmission electron microscopy and DNA synthesis autoradiography. One milliliter of each contrast medium, containing 300 mg iodine per ml, was injected into the aorta. The types of lesions seen on electron microscopy and the rate of DNA synthesis seen on autoradiography established the degree of endothelial damage that had been produced. Of the four contrast agents tested, ioxaglate produced the least amount of cellular change.