F Hartmann - Böcker

The effects of medicaments, used in the treatment of arthritic diseases, on the surface tension of the synovial fluid have been measured. The synovial fluid was obtained from the carpal joints of freshly slaughtered 'calves and from knee joints of arthritic patients. Values obtained for the surface tension (~) of the pure liquids were 47. 6 mN/m and 45. 8 mN/m respectively. The surfGBPce tensions of the additives and their effect,as a function of concentration, on the surface tension of synovial fluid are shown in figure 2. From this diagram it can be seen that bone and cartilage extract(K u. K-Extrakt) is the most passive additive. The D-Glu- coseamine sulphate preparations cause protein be deposited from the syno- vial fluid. This due to the high acidity of these preparations and the effect disappears when they are buffered at pH 6. With Glycosaminoglycane polysulfate the increase of surface tension with concentration is lower than expected in the case of human synovial fluid. This point shill re- quires clarification. x.Bewegungsformen von Gelenken/Types of Joint Movement PRESSURES WITHIN THE HUMAN KNEE: THE CHANGES DURING QUADRICEPS CONTRACTION IN NORMAL AND DISEASED JOINTS Malcolm I. V. Jayson INTRODUCTION Joint disease affects the use of a joint. Conversely, the use of the joint modifies the joint disease. The first proposition is self- evident, the latter less so.

connective tissues are essential for the physical functioning of the animals's body. The condition of the various connective tissues is governed by biochemical factors, anabolism and catabolism, that are controlled by specific enzymes. Any change outside the normal range of metabolism, for instance induced by immunological reactions, may induce a pathological disturbance. The result can be acute or chronic inflammation, or loss of normal function, expressed in loosening, dilatation, breaking, wear, stiffness, shrinking, scars, stenosis, and cirrhosis or any other kind of fibrosis. A first step toward improving our understanding of the feedback mecha­ nism that maintains the biological status and texture of a given connective tissue is to combine what is known about synthesis and enzymatic degradation of the components of fibers and ground substance. Common pathological phenomena like chronic inflammation of immune reactions can be either the result of the cause of disturbances in the sensitive balance of connective tissue metabolism. Nowadays con­ nective tissues are less and less regarded as brady trophic tissue but rather as a stimulating and many-sided problem of research. Before we can understand the pathogenesis of the connective tissue diseases that result in the destructive processes mentioned above, basic research will be necessary. This research will be furthered by a constant exchange of information and the results of· observations. To promote this exchange of information between scientists, symposia on connective tissue research are organized at regular intervals.

This book attempts to acquaint engineers who have mastered the essentials of structural mechanics with the mathematical foundation of their science, of structural mechanics of continua. The prerequisites are modest. A good working knowledge of calculus is sufficient. The intent is to develop a consistent and logical framework of theory which will provide a general understanding of how mathematics forms the basis of structural mechanics. Emphasis is placed on a systematic, unifying and rigorous treatment. Acknowledgements The author feels indebted to the engineers Prof. D. Gross, Prof. G. Mehlhorn and Prof. H. G. Schafer (TH Darmstadt) whose financial support allowed him to follow his inclinations and to study mathematics, to Prof. E. Klingbeil and Prof. W. Wendland (TH Darmstadt) for their unceasing effort to achieve the impossible, to teach an engineer mathematics, to the staff of the Department of Civil Engineering at the University of California, Irvine, for their generous hospitality in the academic year 1980-1981, to Prof. R. Szilard (Univ. of Dortmund) for the liberty he granted the author in his daily chores, to Mrs. Thompson (Univ. of Dortmund) and Prof. L. Kollar (Budapest/Univ. of Dortmund) for their help in the preparation of the final draft, to my young colleagues, Dipl.-Ing. S. Pickhardt, Dipl.-Ing. D. Ziesing and Dipl.-Ing. R. Zotemantel for many fruitful discussions, and to cando ing. P. Schopp and Frau Middeldorf for their help in the production of the manuscript. Dortmund, January 1985 Friedel Hartmann Contents Notations ........................................................... XII Introduction ........................................................ .