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H Wienecke

Publications and source records attributed to H Wienecke.

3 recordsLinked to original sources

[Basic principles of radiosurgical systems and their applications in arthroscopy].

Electrosurgical devices are being used in each medical subdiscipline,and, only recently, they have found widespread distribution in the field of arthroscopic surgery, as well. This development is mainly due to the construction of small and relatively cheap devices that work in a bipolar mode at high frequency. A local plasma field is being built up between the electrodes at the tip of the probe which has enough energy to allow the disintegration of molecules within the treated tissue. The local current flow helps to minimize the numerous disadvantages of monopolar or Laser-based systems. Nevertheless, there is considerable discrepancy between the wide spectrum of clinical use on the one hand and the knowledge of mid- or even long-term biological effects on the treated tissue on the other. So far, clinical and experimental studies exist for the frequent indications of chondroplasty and capsular or ligamental shrinkage. But, still, there is no agreement upon these indications. Studies have shown a considerable number of dead chondrocytes or fibroblasts within a depth of several millimeters within the tissue of the joint capsule or the articular cartilage after electrosurgical treatment. But especially these cells are thought to be essential for the maintenance of the tissue. While the results of other studies seem to be less critical, some authors propose not to use electrosurgery in arthroscopy at all, until further studies prove the safety of these devises. Unfortunately, there is no reliable feedback system for the temperature increase within the treated tissue or other important parameters. The use of these instruments affords a high degree of experience from a skilled arthroscopic surgeon.

Animals↗

Adrenergic control of natural killer cell circulation and adhesion.

Natural killer (NK) cell circulation is subject to adrenergic regulation. Exactly how NK cells are released into the circulation is unknown. In an attempt to identify some of the mechanisms, the present report focuses on aspects of adhesion regulation of NK cells. Results demonstrate that interactions between NK and endothelial cells (EC) in vitro can be reduced by beta 2-adrenoceptor stimulation for as long as the receptor stimulation occurs. The level of soluble adhesion molecules (sICAM-1, sE-selectin, sVCAM-1) in vivo remained unchanged during adrenaline infusion. In vitro analyses further reveal the requirement for Ca2+/Mg2+ in NK-EC adhesion. Blocking studies indicate the involvement of several members of the beta 1(CD29)- and beta 2(CD18)-integrin family, reducing NK cell adhesion by 28 to 39%. Stimulation of beta 2-adrenoceptors in the presence of these blocking antibodies further reduced NK adhesion by an average of 22%. Analysis of NK cell adhesion to various extracellular matrix components demonstrates significant NK cell adhesion to fibronectin but much less to laminin or collagens I and IV. NK cell adhesion to fibronectin was reduced by 50% upon beta 2-adrenoceptor stimulation, independent of the VLA-4/VLA-5 binding site on fibronectin. Together these results contribute to understanding the influences of beta-adrenoceptor stimulation on NK cell circulation and adhesion.

Cell Adhesion↗