Sunao Tawara

Sunao Tawara (Japanese田原 淳; native Nakajima, born July 5, 1873 in Aki ( county Kunisaki, Oita Prefecture ); † January 19, 1952 in Nakatsu ) was a Japanese pathologist a groundbreaking contribution to the elucidation of the conduction of the heart ( conduction system ) made ​​.

Education and work

Born in a rural setting in an era of rapid modernization of Japan Nakajima Sunao was adopted at the age of 19 years of the practicing physician in Nakatsu Tawara Shunto, who had married an aunt of the young Sunao. Since he was destined to continue the practice of his adoptive father, he was like many aspiring peers sent to Tokyo, where he attended schools for English and German to switch then to the Elite School No. 1 ( Dai -ichi kōtōgakkō ), which on study at the young Tokyo Imperial University prepared. Tawaras diploma from the summer of 1897 shows that besides Japanese and classical Chinese and German, Latin, to mathematics, physics, chemistry, zoology and botany learned there.

In 1898, he began his medical studies at the Tokyo Imperial University, where he graduated in December 1901. He then worked as an assistant in the Department of Dermatology, starting in May 1902 in internal medicine. In January 1903, the now thirty-year Tawara traveled to Germany. The cost of the expensive trip and the two-year stay was the adoptive father.

After a short stay in Berlin, he was voted by his fellow countryman Kokubo Keisaku and moved to Marburg in order to continue to form at the Pathological Institute of the University of Marburg with Ludwig Aschoff ( 1866-1942 ). Here he began with studies on the pathological changes of the heart muscle, especially of myocarditis, an issue that Aschoff pursued his time-consuming. Gradually he expanded the laborious investigations on " the presumed centers of the heart rhythm, the ganglion cells and the so-called atrioventricular connection bundle " from. As the estimated two years were over, without templates that sufficient good quality evidence, the adoptive father financed him at great sacrifice another year in which the breakthrough came. Tawara discovered named after him and Aschoff nodes, which he described in 1905 in his " Preliminary Communication " to "Topography and histology of the bridge fibers " as kardiomotorisches center of the heart. In 1906 he published a detailed description of his findings in the book The conduction system of the mammalian heart. In the same year appeared a jointly publicized by Aschoff and Tawara book on Today's doctrine of the pathological- anatomical bases of heart failure.

In June 1906 Tawara took the journey home. In mid-August he reached Kobe, and shortly thereafter Nakatsu. His book quickly caught the attention of professionals. That a private man goes to Germany and is called after the return to an imperial institution, at the time was unusual. Thanks to his pioneering research success Tawara was appointed assistant professor of pathology at the Medical University Fukuoka beginning of 1907, a company founded in 1903 a branch of the Imperial University of Kyoto. Beginning of 1908 he received his doctorate at the University of Tokyo, in July the appointment followed a full professor of pathology. 1911 was the Medical University of Fukuoka on the newly founded Imperial University of Kyushu, until his retirement in 1933 worked at the Tawara - including as Dean of the Faculty of Medicine (1930 ) and as Director of the Institute for bath therapy in Beppu ( 1931-33 ).

In 1933 he reached the age limit and became Professor Emeritus. The remaining years until his death spent Tawara in Nakatsu. When he died at 78 years, him the " Order of the Rising Sun Second Class " was posthumously (勲 二等 旭日 章, Kun - nito Kyokujitsu shō ) awarded.

The medical faculty of the University of Kyushu keeps his name with, Tawara street ' (田原 通り, Tawara - dori ) in honor.

Performance

The scientific collaboration of Ludwig Aschoff and Tawara Sunao led to the second major discovery in relation to the cardiac conduction system, the AV node, which is an essential part of the conduction system of the heart.

Tawara described the histology and the macro or microscopic anatomy of the atrioventricular muscle compounds and their division into two main legs of the animal hearts ( pigeon, rat, guinea pig, rabbit, dog, sheep, calf ) as well as in the human heart. He made exceptionally precise anatomy of the conduction system from the bundle of His, starting to the Purkinje fibers is:

" As you can see from the descriptions, the bundle runs in his previously mentioned parts in all hearts in a fairly consistent manner, particularly in terms of its location and coarser form. As regards the two legs, as is the right always narrower than the left one, and the former is separated by a more or less thick layer of connective tissue of the ventricular muscle. The left leg is from the beginning quite wide, down he is even wider, but at the same time thinner and eventually splits into multiple groups. "

These divisions of the atrioventricular bundle in two main leg wear Tawaras name ( bundle branch ) today.

Works

• The topography and histology of the bridge fibers. A contribution to the theory of the importance of the Purkinje fibers. ( Preliminary communication ). Zentralblatt of Physiology, Vol 19, No. 3, 6th May 1905, pp. 70-77 [ Manuscript Date: April 15, 1905 ]
• Anatomical and histological verification of the incision to the Prof. HE Hering sent dog hearts. Archive for the whole physiology of humans and animals, vol 111, no. 7-8, February 20, 1906, pp. 300-302.
• About the so-called abnormal chordae of the heart. Ziegler 's contributions to the pathological anatomy and general pathology, Volume 39, 1906, pp. 563-584
• The conduction system of the mammalian heart. An anatomical- histological study of the atrioventricular bundle and Purkinje fibers. Jena: Fischer, 1906
• The present study of the pathological- anatomical bases of heart failure: critical remarks on the basis of its own investigations. ( with L. Aschoff ). Jena: Fischer, 1906