Kapronczay Károly szerk.: Orvostörténeti közlemények 230-233. (Budapest, 2015)
KÖZLEMÉNYEK - Elek Gábor—Müller Miklós: Bauer Ervin és a rákkutatás
ELEK, Gábor- MÜLLER, Miklós: Ervin Bauer and Cancer Research 93 Table B. The role of the surface tension in cancer. Bauer’s ideas Comment (page numbers from Lodish et at. 2000 in parentheses) 1 Precancerous state A lthough cancers may be of diverse origin they have a common feature: the surface tension of the mtients’ serum is alwavs decreased, showing that the surface tension of the extracellular fluid between the cells is also reduced in the body. This increases the risk of decreasing cellular cohesion, a most effective comrionent of cellular differentiation (Bauer 1923 a). Tight contact and interaction is indeed a real condition of ontogenetic cell differentiation. The differentiation represents, however, the expression of the DroDer genes of the cell itself, a Drocess not induced by pure cellular cohesion but by specific molecules 11003. 1021!. Cohesion of cells is assured not bv a fluid medium, but bv a network of cell adhesion molecules (968, 993) and by the extracellular matrix secreted by the cells. 2 Isolation (beginning cancer) In a loosened tissue structure scattered individual cells mav lose all contact with neighbouring cells thus escape from organismic control (and organisation!. This fsnatial! isolation nrocess is the definitive step towards malignisation. This happens often in tissues where physiological regeneration is common and undifferentiated cells arise in great numbers (endometrium, mammary glands, skin or chronic inflammation). The chemical structure of the carcinogens is highly diverse, but they all decrease surface tension, as do necrohormones, bile acids, lactic acid in the stomach and lack of calcium too. The essence of the tumour is the functional isolation of cells owing to malignant mutation. Genome stability and regulation of the cell cycle are damaged (529, 1074-1081). Defective (tumour) cells do not perish because the checkpoints do not work (531, 1063-1069). Multiplication of pathological cells becomes steady because of abnormal activation (1056, 1069-1074, 1081). Regeneration is important in carcinogenesis as oncogene mutations happen in dividing cells. The carcinogens are all electrophiles (474); they react with DNA when its double spiral separates during cell division. Cancer cells may be scattered, because first only stem cells are transformed (1062). 3 Age dependence Ba uer, as also his contemporaries, assumed that the surface tension of the serum could be attributed to its complement content. In addition he thought that the serum complement gradually decreases with age and that this is the cause of high frequency of cancer in old age (Bauer 1923a). He imagined that the mechanism of the slow age dependent in vivo decrease of complement level is the same as that of the fast in vitro complement inactivation, i.e. the deformation of the protein molecules, and the change of their dipole moment (Bauer 1923b; see Elek 2014). The complement is only a minor fraction of the seram proteins and its in vitro inactivation corresponds to the denaturation of one or more of its manv components. The in vivo detectable effect of complement depends also on other minor serum constituents, and on the nhvsiological state of the organism (e.g. gravidity). Life is possible without in vivo complement activity of the serum (Schmidt, H. 1955 541-543, 553-554, 1008-1009). Malignant mutation leading to cancer is a multistage process, which may become complete only in old age (1059). 4 Metastasis B auer compared the surface tension of supernatants from various organ homogenates assuming that these represented the supposed intercellular fluid. The surface tension of supernatants was inversely proportionate to the frequency of tumour metastases to the organ in question. He concluded that the cellular surface tension has a greater role in tumour metastasis formation than the direction of blood and lymph flow to the organ in question. Surface tension of the spleen supernatant was prominently high compared to that of the lymph nodes (Bauer and Lasnitzki 1925). Tumour metastasis to any organ is determined primarily by the possibility of the blood and lymph flow from the primary tumour to the organ in question, secondly by tissue affinity between the organ and tumour and, also by their physiological state (Kellner 1971 140-165, 204-206). The supernatant of organ homogenates does not model the extracellular space because the latter contains free water only under pathological conditions (oedema, 992-993). The dissolved molecules determine surface tension. In lymph fewer types of molecules are dissolved than in the supernatant of the spleen rich in blood.
