Biomedical subjects

I Hort

Publications and source records attributed to I Hort.

11 recordsLinked to original sources

PubMed1999

[Not Available].

Explore the source record for details and available documents.

Cerebrovascular Disorders↗

PubMed1998

Medieval descriptions and doctrines of stroke: preliminary analysis of select sources. Part I: The struggle for terms and theories - late antiquity and early Middle Ages.

This first of a series of papers on the history of stroke presents an examination of a number of exemplary Greek and Latin sources, ranging from late antiquity to the dawn of the Middle Ages. We first establish a chronological order of various groups of texts and, whenever possible, ascertain the relationship of one group of writings to another. In the second century A.D., Galen had used the Hippocratic concept of humoral imbalance as a fundamental explanatory mechanism for the interpretation of clinical manifestations of apoplexy. Galen definitely rejected the Aristotelian precept of the primacy of the heart. According to his teaching, stroke resulted from the accumulation of a thick and dense humor in the ventricles of the brain blocking the passage of the animal spirit. Galen's Greek texts became axiomatic for compilers of the Byzantine period (Aetius of Amida, Alexander of Tralles, Paulus of Aegina). But his ideas contrasted starkly with the theories of the Methodical School which exerted - through the Latin writings of Caelius Aurelianus - a certain influence on authors of the Latin West (Cassius Felix, Theodorus Priscianus). References to stroke can also be found in many theological writings of the early Middle Ages.

Cerebrovascular Disorders↗

PubMed1998

Medieval descriptions and doctrines of stroke: preliminary analysis of select sources. Part II: between Galenism and Aristotelism - Islamic theories of apoplexy (800-1200).

This second paper on medieval descriptions and doctrines of stroke reviews concepts outlined by famous Muslim physicians of the Middle Ages such as Rhazes, Haly Abbas, Avicenna, and Averroes. Contrary to a popular belief, Islamic neurological texts represent not only a bridge between ancient and western medieval medical knowledge, but also document remarkable advancements. Whereas statements on diagnosis and prognosis lack originality, the endeavors of physician-philosophers and medical authors led to substantial additions and important changes in theory. Such modifications include the integration of ventricular doctrine and particularly the attempt to unify Aristotelian and Galenic tenets which resulted in a complex discussion about the seats and causes of apoplexy. The fairly simple model handed down by Galenists of the Byzantine period was replaced by more detailed classifications, which proposed "cerebral" as well as "vascular" origins of the disease without suggesting a "cerebrovascular" etiology. Islamic therapeutic strategies included dietetic, pharmacological and surgical elements. The use of the cautery in "chronic apoplexy" was a special feature of Arabic surgery.

Arab World↗

PubMed1998

Medieval descriptions and doctrines of stroke: preliminary analysis of select sources. Part III: multiplying speculation - the high and late Middle Ages (1000-1450).

By analyzing a body of texts compiled by various medical authors from the 11th to the 15th century, four basic developments can be noted: (1) From the beginning of the eleventh century the reception, translation and assimilation of Arabian and arabicized ancient texts became the ultimate goal of Western medicine (Constantine the African, Arnad of Villanova, et al.). Concepts of stroke were consequently guided by textual tradition, not by observation. (2) Scholastic speculations about different aspects of apoplexy, especially those concerning its origins, were numerous (Johannes Platearius, Batholomaeus Salernitanus, Pietro d'Abano, Giacomo da Forli). Although most medieval physicians used the ancient doctrine of the four humors as model and explanation, opinions differed in many ways. (3) Attempts developed to present a simple outline of the etiology, the prognosis, and the treatment of the disease (Gilbertus Anglicus, Bernard of Gordon, John of Gaddesden). (4) Although lacking in originality, many of these writers nevertheless achieved a certain uniformity in presenting main topics, thus setting the standard for later practitioners.

Arab World↗

PubMed1981

[From the ameba to the pulsating heart: evolution and fine structure of the intracellular movement apparatus (author's transl)].

Different kinds of cell motility are reviewed in this paper with special regard to development and ultrastructure. The variety of animal cell motility types can be reduced to three principles : ciliary and ameboid movements and muscle contraction. The ultrastructure of all kinds of cilia is very similar from single cell organisms to highly specialized cells of the human body e.g., ciliary respiratory epithelium. As a rule, ciliary movement is caused by minimal sliding of the nine double tubules consisting of tubulin, a protein differing from myosin and actin. Ameboid movement and muscle cell contraction are based on the sliding filament mechanism of actin and myosin. Although the principles of this mechanism have not changed during evolution some differences in the structure and arrangement of actin and myosin filaments occurred. Obviously, the high degree of order of the myofibrils of vertebrate heart and skeletal muscle cells has developed from loose and rapid changing arrangement of contractile filaments in ameboid cells. There are some changes of residues in the actin and myosin molecules during the development of the intracellular contractile system. Finally, some peculiarities of the myocardium, its special arrangement of muscle cells and some disturbances of the contractile filaments under pathologic conditions are discussed.

Amoeba↗

PubMed1968