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A Frey-Wyssling

Publications and source records attributed to A Frey-Wyssling.

14 recordsLinked to original sources

Polyvinylchloride (PVC) particles implantation in mouse liver. A technique for experimental study of schistosome eggs-induced liver pathology.

An injection of suspended PVC particles in the caecal vein of mice induces a foreign-body portal granuloma reaction in the liver. Plastic casts of the portal system, after PVC particles implantation, show modifications in the portal bed and are compared with plastic casts obtained in mice infested by Schistosoma mansoni. This technique can be useful to study the cellular dynamics of the portal granuloma and can be a model for schistosomal eggs induced liver pathology.

Animals↗

[Definition of the organell concept].

Since the essential cytological functions are endergonic processes, the organelle cannot be defind without considering the necessary energy transfer. Therefore, a sensible definition may read: The Organelle is a cytoplasmatic structure capable of funtional energy consumption (Frey-Wyssling 1977).

Energy Metabolism↗

[The scientific work of W. J. Schmidt (author's transl)].

Ten examples from W. J. Schmidt's workshop illustrate the method of ultrastructural research before the advent of the electron microscope. The consistency is shown with which the research worker W. J. Schmidt pursued his goal, how he succeeded in making fundamental discoveries with his polarizing microscope, and interpreted the results of his indirect structural investigations in such a forward-looking and clearsighted manner that many of them were confirmed by direct reproduction in the electron microscope. This makes W. J. Schmidt one of the great pioneers of ultramicroscopic structural research. He was an extremely prolific writer. His list of publications numbers 404 scientific contributions, three classical books among them. The last of these three monographs was written in 1971; its title is "Polarizing Microscopy in Dental Tissues"; it deals with the ultrastructure of teeth, a subject which never ceased to attract his attention during the more than 50 years of his career as a scientist. It was his intention to write such a textbook on the ultrastructure of teeth during his retirement, a task which he accomplished in spite of the infirmities of old age, thanks to his unbroken will to work. Another characteristic feature of W. J. Schmidt was his extraordinary insistence on complete independence; there are only four among his 404 publications which he wrote, at an advanced age, jointly with Helmut Ruska, and the dental monograph he published in callaboration with A. Keil. Everything else was entirely his own effort. His capacity for work was almost inexhaustible. In 1937, for instance, he published 18 scientific papers, among them his richly illustrated protoplasm monograph of 388 pages. His inflexible will to observe everything personally and to interpret and edit his findings alone was part of his special intellectual constitution. In discussions he stubbornly defended his point view and considered suggestions and new ideas only after he had tested them with his own experiments. This had already become evident at the beginning of his career in a discussion with Ambronn of the nature of birefringence of organized substances. But once he had accepted something as proved he propounded it with persistence and enthusiasm.

Cell Biology↗

[Microtubules].

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Microtubules↗

Isolation of glucanase-containing particles from budding Saccharomyces cerevisiae.

In an investigation of the role of glucanases in modifying yeast cell walls at the location of new buds, vesicles derived from the endoplasmic reticulum, which are secreted locally into the cell wall of growing buds and may be involved in the secretion of glucanases, have been isolated.In yeast, exo-beta-1,3-glucanase (EC 3.2.1.6) is present both extra- and intracellularly. Exponentially growing cells contain about 16% of the enzyme activity intracellularly (within the plasmalemma). Most, if not all, of this intracellular glucanase is sedimentable. Of the three classes of subcellular particles that contain glucanase, one is almost completely absent from stationary phase cells and almost absent from cells of the late budding phase of the budding cycle. These particles were isolated from budding cells by combined differential and density gradient centrifugation. They contain exo- and endo-beta-1,3-glucanases, mannan, and protein. The isolate consists mainly of membrane-bounded particles with diameters corresponding to those of the secretory vesicles observed in situ. It is concluded that these particles are identical with the vesicles derived from the endoplasmic reticulum.

Cell Wall↗