Alfred Kohn

Alfred Kohn ( born February 22, 1867 in Libin, Czech Libyně, a district of Lubenec in the Karlovy Vary region, then Austria - Hungary, now Czech Republic, † January 15, 1959 in Prague) was an Austrian - Czech histologist. He has, particularly with studies on the ontogeny and comparative anatomy, the parathyroid glands separated from the thyroid gland, isolated adrenal medulla of the adrenal cortex and associated with the sympathetic nervous system, as well as disconnected the paraganglia of other cell clusters.

A detailed biography has his pupil Watzka Maximilian (1905-1981), later director of the Anatomical Institute of the Johannes Gutenberg University Mainz published. A typewriter manuscript with memories of Rose Scheuer - Karpin doctor (1912-2013) is available via the Leo Baeck Institute. A Czech biography comes from the Prague anatomist Miloš Grim (* 1941) and Ondrej Nanka (* 1972) ( see references ).

Life

Kohn was one of eight children of a small merchant and innkeeper. The site of the birthplace, the village Libyně No. 51, is broke today. After visiting the Old Town Gymnasium in Prague Kohn studied at the German Charles-Ferdinand University in Prague medicine. In 1891 he became an assistant to Siegmund Mayer on Histological Institute. In 1895 he passed the state examination and was awarded his doctorate for Dr. med. Four years later, after extensive travels among other things, Zoological Station of Trieste, he qualified as a professor of Histology with a thesis on the adrenal gland of sharks. In 1911 he was Mayer's successor as professor. His lectures not only the doctors had come, but also science students and young artists. His universal education and knowledge of the classical languages ​​of Greek, Latin and Hebrew - which came along with the German Czech and French - would have enabled him to digressions in the world literature. " The lectures were spiced with quotations from the 'Faust' and sometimes helped by their associative power to consolidate the mediated knowledge. "

1937 Kohn was given emeritus status. Watzka, who had his habilitation in 1934, took only representative, then full-time over the chair. In 1939, the " remainder of Czechoslovakia " occupied and annexed by Nazi German Reich. Kohn " enjoyed ... a little honeymoon period. He ... had the infamous yellow star for identification as a Jew wear, but was still living in his old apartment in the Ječná 9, with his housekeeper, the faithful Anna. " In 1943 he was interned in the concentration camp Theresienstadt. He survived thanks to him underestimated Nazi colleagues like Watzkas and the gynecologist Hermann Knaus. " Watzka clung to his old professor as to a father, but he was also an early member of the Sudeten German Free Corps. So he accompanied Kohn to Theresienstadt, probably in SS uniform, and provided good accommodation and decent treatment. " With the arrival of the Red Army in May 1945, Kohn was released. The faithful Anna ' Anna Žitková, Aryan had to be rewritten after his internment the apartment and " waiting for him ." As the home of the former professor of the German university confiscated and his old-age pension should be revoked, the Minister intervened Ascended husband of a former student.

Kohn worried about the welfare of Anna after his death. Through a friend, Ernst, "came this problem before the Council of Ministers. Its proposal was: marriage. Ernst took over the delicate task of the courier, who was to deliver the message. He then told me how the professor without hesitation, smiling, with only feigned resignation, the proposal agreed. Anna was in 1912, still young, came to Professor Kohn to lead his household. Successful, charming, unmarried, he drew the admiration of women to themselves. Anna ... lived in her small world, took care of the apartment, the well-being of the professor and took him all the practical concerns from - for decades. So she had lived and probably also loved the professor. " After Kohn's death found friends for Anna a small and modern apartment. However, the police had to open the 9 apartment in the Ječná. " Anna was lying dead on the ground. Life had lost its meaning for them. Now she is buried beside her husband in the Jewish cemetery in Prague- Strašnice. "

Work

Parathyroid

Even before his state exams and shortly thereafter Kohn published two fundamental papers on the parathyroid glands. They had been in 1880 by the Swedish physician Ivar Sandström ( 1852-1889 ) discovered and described as glandulae parathyreoideae. Your life need the French physiologist Marcel Eugène Émile Gley (1857-1930) had recognized. They were held for organs with similar ontogeny and function as the thyroid. Kohn disagreed and therefore proposed a new appointment: " As more view secured in the course of the investigation in me that is so often claimed identity between, parathyroid ' and thyroid very of the proof is still in need, I preferred to take the ... to bring selected under the assumption that identity names to nothing präjudicirenden name, parathyroids ' in application., Personal appearance parathyroids ' I call the institution in question to get it from a similar, described in the second part of this work, the inner epithelial bodies ' to distinguish the thyroid gland. "A striking evidence for the otherness found Kohn 1898, together with the pathologist Rudolf Maresch (1868-1936): In a child, which the thyroid gland completely missing were the parathyroid glands formed normally.

Adrenal gland

A similar question as to the parathyroid glands in their relation to thyroid stood for the adrenal glands. Since 1836 it was discovered that they consisted of two components, the cortex and the medulla. Kohn examined them through the series of vertebrates from fish to mammals. The adrenal own, he wrote in 1898 in the Prague Medici niches weekly, is the bark: " The detailed analysis of the mammalian adrenal gland confirmed directly the product obtained from comparative anatomical studies consider that the actual adrenal gland is an epithelial organ, so in Mammals merely by the cortical substance represented appears. What was so far ... " marrow cells " called, is nothing more than an in mammals previously unknown, the sympathetic nervous system associated special kind of cells. ... Chromaffin Sympathicuszellen I will " Let the adrenal cortex as epithelial organ " because one of its most striking features, the call short ... affinity for chromium salt solutions. Similar to the parathyroid glands in the neighborhood of the thyroid gland ", similar to the anterior pituitary and thyroid glands. " The medullary substance belongs to their genesis both, and after their final, geweblichen character to sympathetic. "

The " affinity for chromium salt solutions " based on the presence of high concentrations of the catecholamines noradrenaline and adrenaline in the adrenal medulla. They react with oxidizing agents such as chromates to yellow-brown products. The neologism " chromaffin " was influential. 1902 repeated Kohn: "In the vertebrate organism, a new, special type of tissue is necessary to distinguish the chromaffin tissue. Its specific component is the chromaffin cell. Chromaffin cells and sympathetic cells develop from common plants. "On the physiological significance he pointed to " the first knowledge of a most remarkable effect of chromaffin substance " out, discovered by George Oliver and Edward Albert Sharpey - Schafer, the history of Catecholaminforschung issuing increase in blood pressure injection of adrenal gland extracts.

Paraganglia

The chromaffin cells were not restricted to the adrenal medulla. Kohn found chromaffin cell clusters in the body widespread. He called them paraganglia:

" In this way I had reached the point of a new cell type - the chromaffin cell, a new Gewebsform - the chromaffin tissue, a new body type - the chromaffin organs or paraganglia -. Establish "

" In the vertebrate organism, a new special Gewebssystem is to distinguish which remained undetected or ignored until now. They are. , The paraganglia or chromaffin body that are genetically and anatomically linked to the sympathetic nervous system About ... the physiological significance of the chromaffin organs one knows nothing reliable. Intravenous injections of their extracts increase the arterial blood pressure. From ... chromaffin tissue may emerge tumors whose cells are chromaffin again. Chrome affinity and pressor potency should be frequently used as diagnostic criteria of retroperitoneal tumors. "

The paraganglia include - in addition, for example, the carotid body and the glomera aortica - the Paraganglion aortic abdominal. It is named after Emil Zuckerkandl, then director of the Anatomical Institute of the University of Vienna, also Zuckerkandl organ. Zuckerkandl held the cell clusters but for a lymph node. Only Kohn gave him the correct diagnosis. Zuckerkandl concealed das. " This behavior of a saturated privy councilor a young lecturer against Kohn has deeply offended and he later often regretted that he had preserved Zuckerkandl before, these organs to publish as a special lymph nodes, as he wanted to do it anyway. "

More

Kohn's center of interest remained the endocrine glands. Had he detected a banal lymph nodes than in the case Paraganglion Zuckenkandls, so he exposed reversed a supposed endocrine gland insularis cervicalis as banal adipose tissue. He conducted research on the pituitary and the gonads. He showed that " interstitial cells " in the suspensory apparatus of the ovaries corresponded to the Leydig cells of the testis and were not paraganglia.

It has contributed to the realization that the Schwann cells are derived from the neuroectoderm.

Around 1910, an Axolotl was accidentally fed a piece of thyroid at the Prague Institute. Kohn observed that the animal is gray discolored and started to crawl out of the water, while the gills atrophied. He suspected a connection and contributed to the student J. Frederick Gudernatsch (1881-1962), later professor of anatomy at Cornell University, experiments with tadpoles on. Thus, the role of the thyroid gland was discovered during the metamorphosis. "It is only to be emphasized here that this fundamental discovery a vested product Kohnschen mind was, even though the outer success fell to another. Kohn, the otherwise ambition was totally foreign, but later it hurt a lot and he often talked about how generous he then gave away his beads. "

Recognition

1901 Kohn was for the best theoretical and medical work of the last three years the Goldberger Award of the Society of Physicians in Vienna, whose honorary member, he was later. He was an honorary member of the German Society of Endocrinology. In 1932 he became a full member of the German Academy of Sciences Leopoldina. On November 30, 1938, he was with the note " Membership deleted ( non-Aryans ) " shall be deleted. For the 400 - year celebration of the Friedrich -Schiller- University of Jena in 1958 he became its honorary doctorate. Czechoslovakia awarded him the Order of the work. The Austrian anatomist Peter Böck dedicated his book about the paraganglia (from the English ) " to the memory of Alfred Kohn ( 1867-1959 ), Austrian histologist of the Charles University, Prague, the term ' chromaffin ' introduced and the system of ( chromaffin ), paraganglionären cells ' defined. "

Literature with comments

• Hermann Blaschko: Reminiscences. In: Earl Usdin, Arvid Carlsson, Annica Dahlström, Jörgen Engel ( eds ): Catecholamines, Part A: Basic Mechanisms of Peripheral. Alan R. Liss, New York, 1984, pp. 3-4. ISBN 0-8451-2798-5.

Blaschko had his information about the Mainz pharmacologists Erich Muscholl of Maximilian Watzka.

• Peter Böck: Alfred Kohn, 1867-1959. In: The Paraganglia. Handbook of microscopic anatomy of the human band VI. Vascular and Lymphgefäßapparat, endocrine glands, pp. 218-220. Springer -Verlag, Berlin 1982, ISBN 3-540-10978-1.

Böck's brief biography is based on Watzka 1959 ( see below)

• Ludmila Hlaváčková, Petr Svobodný: Alfred Kohn. In: . Biographical Dictionary of the German Medical Faculty in Prague 1883 - 1945 Karolinum, Prague 1998, pp. 116, ISBN 80-7184-521-3 ..

• O. Nanka, M. Grim: Alfred Kohn, profesor histology na Německé univerzitě v Praze. In: Časopis lékařů českých 147, 2008, pp. 240-244. Accessed on 28 April 2013.

• Rose Scheuer - Karpin: 30 -page manuscript Typewriter, after 1987, with their memories. Website of the Leo Baeck Institute. (PDF, 34.2 MB) Accessed on April 15, 2013.

The manuscript is an impressive language and content document of life in the former Bohemia in the first half of the 20th century. Scheuer - Karpin told from baseline in Prague 1930:

• Scheuer - Karpin: Prof. Alfred Kohn †. In: The German health care system. 14, 1959, pp. 501
• František Tvaroh: K 90 narozeninám prof. Dr Alfreda Kohna. In: Časopis lékařů českých 96, 1957, pp. 355-356.
• Max Watzka: Alfred Kohn †. In: Anatomical Gazette. 106, 1959, pp. 449-457.