The fine structure of human digital arterio-venous anastomoses (Hoyer-Grosser's organs)

Hoyer-Grosser's organs were studied in human digital biopsies. The fine structure of both the supplying arteries and collecting veins was found to be inconspicuous. Endothelial cells in the AV canals form a continuous layer. They are characterized by their rich content of specific organelles (Weibel-Palade bodies), especially in the venous segments. The epitheloid zone is composed of a variety of ramified smooth muscle cells (RSM). These appear either dense, when well provided with bundles of myofilaments, or clear, when including only a few myofilaments. The nuclei of dense RSM show condensed chromatin, while those of clear RSM are larger with loose chromatin texture. In addition, all transitional forms occur. Cell organelles are rarely seen within all types of RSM. The cytoplasmic processes reach other as well as endothelial cells. The preservation of our material did not allow observation of specialized membrane contacts in these zones. All RSM are invested with a regular basal lamina and well provided with surface vesicles. Profiles of free basal lamina material and faint collagen (argyrophil) fibers are seen in the wide intercellular spaces. RSM poor in myofilaments are interpreted to represent "epitheloid cells" of light microscopy. Their number constantly decreases from the arterial segment of the AV canal to the venous segment. Here the cytoplasmic processes of RSM become less pronounced and the wall of the anastomotic segment continuously changes to that of the collecting vein. Dense RSM rich in myofilaments are compared with pacemaker cells found inthe ureter. Both internal and external elastic membranes are absent in AV canals. A dense network of unmyelinated nerve fibers is found in the adventitial layer of the AV canal, especially in its arterial segment. The axons branch out from small dermal nerves which also contain two or three myelinated axons. The myelin sheaths terminate where the axons reach the adventitia of the AV canals. Axon varicosities filled with mitochondria are thought to be terminals of myelinated axons and are interpreted as receptory. Axon varicosities with synaptic-type vesicles are assumed to be terminals of sympathetic and para sympathetic fibers. All axon profiles are confined to the adventitial layer of the anastomotic segment.

In vitro and in vivo observations on the erythrocyte uptake of 17-monochloroacetylajmaline

The in vitro and in vivo observations on the uptake rate of 17-monochloroacetylajmaline by human erythrocytes showed that about 30-35% of the drug is bound to red blood cells. These findings suggest a peculiar affinity of the drug for the erythrocytes, may be for the membrane or stromal phospholipids.

Plasma and red blood cell phospholipids in chronic liver diseases

The total phospholipid content and the individual phospholipids, phosphatidylcholine, lysophosphatidylcholine, phosphatidylethanolamine and phosphatidylserine, and sphingomyelin were determined in the plasma and red blood cells of 58 patients with chronic liver disease and 12 control subjects by quantitative extraction and thin-layer chromatography. The total phospholipids were significantly reduced in both the plasma and red blood cells of the patients with liver disease. For the individual phospholipids, plasma sphingomyelin was significantly decreased, in the red blood cells there was an increase in lysophosphatidylcholine and a decrease in phosphatidylethanolamine and phosphatidylserine compared to the control subjects. It is suggested that in chronic liver disease the red blood cell lipid disturbances follow more closely those of the hepatocyte than those in plasma.

[Total and fractionized plasma phospholipids in chronic liver diseases]

The literature data relating to the importance of the liver in fat metabolism, and the behaviour of plasma and red cell phospholipids, cholesterol, triglycerides, fatty acids and lipoproteins in acute and chronic liver disease is reviewed. The results of an investigation of the diagnostic and prognostic significance of total and single plasma phospholipid levels in a series of 70 cases (5 chronic aggressive hepatitis, 12 compensated cirrhosis, 41 uncompensated cirrhosis, and 12 controls) are presented. Quantitative assessment by means of thin-layer chromatography showed four features of marked prognostic interest: a) a significant decrease in total phospholipids; b) increased phosphatidyl choline; c) increased phosphatidyl ethanolamine; d) decreased sphingomyelin. In discussing the results, stress is laid on the fact that this method offers a sufficient close evaluation of the clinical picture with respect to both the evolution of cirrogenic liver diseases and the effectiveness of their treatment. It also enables an assessment to be made of liver cell mitochondria function.