[Permeability characteristics of the endocardium and the myocardial capillaries to horseradish peroxidase in fetal and postnatal rats]. / Permeabilitätseigenschaften des Endokards und von Capillaren des Myokards bei fetalen und postnatalen Ratten für Meerrettichperoxidase.

After intravenous or intracardial application of horseradish peroxidase (HRP) at the myocardial capillaries of fetal, juvenile and adult rats a fast transport of the tracer into the interstite can be observed. In the fetal cases the transport takes place especially through the interendothelial junctions, in the postnatal cases a considerably amount of the peroxidase traversed also by plasmalemmal vesicles. In adults the T-tubules of the myocytes are labelled already after 15 min of circulation. From fetal stages up to adults the junctions of the endocardium are well permeable to HRP. After a short circulation time we found large deposits of reaction product in the subendocardial space. The reasons for the different permeability of fetal heart and skeletal muscle capillaries were discussed.

[Demonstration of ATPase activity in skeletal muscle fibers of the triceps muscle of arm in white rats during development]. / Zum ATPase-Nachweis in Skeletmuskelfasern des M. triceps brachii von weissen Ratten im Entwicklungsgang.

On the base of modified calcium and method from Zebe and Falk (1964) for demonstration of ATPase activity results at the long head of the triceps muscle of white rats aged 1, 3, 6 weeks and 3 month were shown. This method is proper to make visible alteration of the localisation of the reaction product during the postnatal development. Further investigations are necessary in order to correlate the steps of differentiation of muscle fibres with the strength of ATPase activity.

[Electron microscopic study of the permeability of terminal blood vessels of the M. triceps brachii to horseradish peroxidase in fetal, juvenile and adult rats]. / Elektronenmikroskopische Untersuchungen zur Permeabilität von Blutgefässen der terminalen Strombahn des M. triceps brachii fetaler, jugendlicher und erwachsener Wistar-Ratten für Meerrettichperoxidase.

At the basis of some ultrastructural differences in fetal, juvenile and adult rat triceps muscle capillaries as described in preliminary papers the permeability of these capillaries to horse radish peroxidase was investigated. Capillaries of fetal and juvenile rats up to the 3rd week after birth were impermeable to horse radish peroxidase (HRP) for 2 and 10 minutes after injection, which can be explained with the low pinocytotic activity and the more complex structure of the junctions. Capillaries of the triceps brachii muscle in adult rats aged 2 month and more show a low permeability to HRP 2 and 5 minutes and a high permeability 15 minutes after the injection of the tracer. In the capillary segment of the terminal bed the tracer was traversed especially by the means of vesicles and some transendothelial channels built by linked vesicles. The interendothelial junctions seemed to be tight. In the venular segment of th capillaries and in small postcapillary venules additional to the vesicular transport a high permeability of some junctions was stated. The significance of the different permeability of distinct segments of the terminal vascular bed to small macromolecules is discussed with respect to the theories of th physiologists and compared with the results of recent investigators.

[The Sézary syndrome--an erythrodermic T-cell-lymphoma]. / Das Sézary-Syndrom--ein erythrodermisches T-Zell-Lymphom.

Report on a 75-year-old patient with Sézary syndrome which is characterized by the following leading symptoms: Erythrodermia, leukocytosis, circulating atypical lymphocytes with cerebriformous nuclei (Sézary cells) and swollen lymph nodes. Light microscopic and electron microscopic findings refer to a transitory situation of the Sézary cells from the reactive character to the (pre)neoplastic one. The disease is classified by T-(helper)cells as a low grade non-Hodgkin-lymphoma in parallel to mycosis fungoides and in general it finishes lethally after a course of 5 to 8 years. Apart from local steroid ointments and UV-irradiations the internal application of steroids, in the late stage if necessary in combination with cytostatics is recommended for therapy.

[Light and electron microscopic studies of the skeletal muscle (M. triceps brachii) capillaries in white rats aged 2 to 20 months]. / Licht- und elektronenmikroskopische Untersuchungen an Skelettmuskelkapillaren (M. triceps brachii) weisser Ratten im Alter von 2 bis 20 Monaten.

The capillarisation of the triceps muscle of white rats was investigated with light and electron microscope up to the age of 20th month. During the postnatal development the capillary to fiber ratio corresponding to the increase of the number of capillaries is well adapted to an exponential function. The rapid increase of thickness of the muscle fibers causes a decrease of the number of capillaries per area unit. After the third week of life with histochemical methods the differentiation of muscle fiber types is possible, well correlated to the beginning of motoric activity. Ultrastructural alterations of the muscle capillaries consist in a flattening of the endothelium within the first month of postnatal life, a decrease of the content of organelles, a high degree of vesiculation and a continuous thickining of the basement membrane up to more than 100 nm. The interendothelial clefts show a simple structure containing 1--2 junctional zones and only few dilatations.

[The postnatal development of capillaries in the triceps muscle of arm of the white rat. Light and electron microscopic studies]. / Uber die postnatale Entwicklung von Kapillaren im Musculus triceps brachii der weissen Ratte. Licht- und elektronenmikroskopische Untersuchungen

This paper continues former ultrastructural investigations about fetal development of capillaries in the muscle anlage of the fore limb of white rats. Present investigations deal with postnatal ultrastructural changes of the capillaries of the triceps muscle of rats from the 4th up to the 23rd day p.p. Counting of the capillaries with light and electron microscope reveal a linear increase of the capillary to fiber ratio in this period proportional to the growth of the muscle. Related to a defined area however the number of capillaries remains constantly. Ultrastructural changes of capillaries consist in further flattening of the endothelial profiles, decrease in number or organelles (mitochondria and endoplasmic reticulum), while the number of pinocytotic vesicles remains highmthe endothelial joints become less interdigitated, the basement membrane shows an increase in density leading to a temporary decrease in thickness. Since the 9th postnatal day all of the capillaries including buds closely border upon the muscle fibres. The distance between endothelium and myofiber diminishes up to 0,1 mum.