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PubMed1967

Definitions of taxa.

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Biological Evolution↗
PubMed1984

[Development and neoplastic progression of benign and malignant cutaneous cylindroma].

Cylindromas of the skin are subjected to a constant biological evolution in their growth and differentiation, leading in rare instances to metaplasia or even in true malignancy. By using optical microscopy and autohistoradiography after incorporation of tritiated thymidine and proline, several stages of neoplastic progression can be recognized such as growth, primary involution, inflammatory regression and malignant transformation. The stage of growth is characterized by low proliferative indices in clear cells of the lobules while dark cells are almost not dividing. Primary involution consists of massive accumulation of basement membrane components accompanied by lysis of cells. Inflammatory regression results from the infiltration of the neoplasm by lymphocytes with disappearance of the basement membrane. Malignant transformation appears to be multifocal.

Aged↗
PubMed1983

The functional, comparative and evolutionary anatomy of myosins.

Actins and myosins are generally present in all animal, plant and fungal cells, and in some, if not all, prokaryotes as well. It is proposed that, in general, myosins can carry specific loads as they move along actin filaments, thus mediating a form of active transport. Myosins exert their mechanical forces by a lever action (moklokinesis) of a part of the molecule: the S-1 "head" in the case of muscle myosins. Various portions of myosin molecules can be assigned specialized functions. Each such part can be designated by an appropriate functional name. Examples are: the enzyme portion (zymomere), the motor portion (dynamere), the lever portion (moklomere), a connecting portion (desmomere), a coupling or binding portion (haptomere), and one or more flexible portions (kamptomeres). These parts can be recognized in highly evolved and specialized muscle myosins and can be postulated in simpler, single headed myosins. A primitive myosin, represented principally by a moklomere equipped with a zymomere and a dynamere, is envisioned as an evolutionary ancestor of all myosins. This primitive myosin resembles the S-1 head of muscle myosin. I suggest that from such a primitive myosin, more elaborate single-headed myosins have evolved, equipped with specific haptomeres coupled to the moklomere by desmomeres and kamptomeres. From such general single-headed myosins have arisen the highly specialized two-headed myosins represented in muscle. It is suggested that the two-headed feature is favored in myosins capable of forming bipolar filaments.

Actins↗