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  • 1
    Electronic Resource
    Electronic Resource
    Experimentelle Untersuchungen mit einem biologischen Material zum Verschluß von Bauchwanddefekten (1985)
    Springer
    Langenbeck's archives of surgery 363 (1985), S. 253-260 
    Details
    ISSN: 1435-2451
    Keywords: Biomaterials ; Collagen ; Hernia ; Reconstructive surgery
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Ein neuartiges Präparationsverfahren zur Herstellung biologischer Implantationsmaterialien, das erlaubt, natives Kollagen in seiner biologischen Textur in der rekonstruktiven Chirurgie einzusetzen, wurde in bezug auf seine Verwendbarkeit zum Verschluß von Bauchwanddefekten untersucht. Als Versuchstiere dienten 30 weibliche Lewis-Ratten, bei denen ein 3 × 4 cm messender Defekt der ventralen Rumpfwand mit einem Kollagenim plantat verschlossen wurde. Das Material wurde nach 4, 6 bzw. 8 Wochen entnommen und lichthistologisch untersucht. Als Kriterien für die Revitalisierung wurden die Art der eingewanderten Zellen, die Immigrationstiefe und-dichte, sowie das Einsprossen von Gefäßen herangezogen. Die Implantate waren nach 4 Wochen in den Randbereichen gut vascularisiert und von Fibroblasten durchsproßt. Im Zentrum war die Zellimmigration spärlich. Nach 6 Wochen hatte die Zelldichte auch im Zentrum deutlich zugenommen. Vereinzelt ließen sich auch kleinlumige Gefäße nachweisen. Nach 8 Wochen war die Zelldichte in sämtlichen Bereichen der Implantate gleichmäßig hoch, in allen Abschnitten ließen sich Gefäße und vereinzelt Capillarbündel nachweisen. Wir halten das von uns untersuchte Material sowohl in bezug auf seine pyhsikalischen Eigenschaften, als auch in bezug auf die Inkorporation und Revitalisierung zum Verschluß von Hernien für durchaus geeignet. Insbesondere scheint das Material im Vergleich zu anderen biologischen und allogenen Materialien früher eine höhere Festigkeit des Hernienverschlusses zu garantieren.
    Notes: Summary A new preparation process was studied which should allow the implantation of collagen type I in its native structure in reconstructive surgery, in this special case for closure of incisional hernias. As experimental animals we used 30 female Lewis rats. A defect of the anterior abdominal wall —measuring 3 × 4 cm — was closed with our collagen substitute. Biopsies were taken after 4, 6 and 8 weeks and examined morphologically. As criteria for revitalisation and revascularisation we used type of immigrated cells, depth and density of immigration and formation of new blood vessels. After 4 weeks the implants were immigrated by fibroblasts, density diminishing towards the centre. On the muscle-implant-interface good revascularisation could be seen. After 6 weeks density of immigrated cells has distinctly increased even in the centre of the collagen implant. Sporadically small vessels could be seen. Eight weeks after implantation density of immigrated cells was at the same high level, and capillary bundles could be seen within the whole implant. We think that the studied collagen implant is suitable for the closure of henias as shown by its physical and morphological properties. Especially it seems to guarantee an earlier and tighter closure of hernias in comparison to other materials.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01262499
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  • 2
    Electronic Resource
    Electronic Resource
    Colchicine-induced stimulation of PMN motility related to cytoskeletal changes in actin, α-actinin, and myosin (1993)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 25 (1993), S. 10-18 
    Details
    ISSN: 0886-1544
    Keywords: microtubules ; blebs ; locomotion ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Colchicine-induced stimulation of polymorphonuclear leukocyte (PMN) locomotion is an interesting model because extension of blebs at the front occurs at a rate (about 2.4 μm/s) which is far above that reported for growth of actin filaments. The following cytoskeletal changes were observed in colchicine-treated PMNs: (1)a small increase in cytoskeleton-associated actin was noted, as well as a somewhate more pronounced increase in cytoskeleton-associated α-actinin, as compared with untreated or DMSO-treated controls. There was, however, no measurable increase in F-actin as determined by NBD-phallacidin blinding; (2)the values for the ratio (α-actinin/actin) are lower in PMNs treated with colchicine for 30 min, as compared with PMNs stimulated with fNLPNTL for 1 minute (non-polar ruffling cells) or 30 min (polarized locomoting cells); thus, this ratio may depend on the type of PMN motility; (3) in polarized PMNs F-actin was mainly located linearly all along the cell membrane; there was more intense staining at the front of the cells; (4) α-actining appeared to colocalize with F-actin at the leading front, but not with F-actin at the tail of polarized cells; (5) myosin was preferentially found at the rear part of polarized cells but not or only to a small extent at the front. Our data indicate a close functional correlation between microtubules and microfilaments. We speculate that F-actin in combination with α-actinin promotes expansion of pseudopods, whereas myosin combined with F-actin promotes contraction. In more general terms we suggest that different forms of PMN motility are generated by differential selective interaction of cytoskeletal compnents and variations in the composition of the cytoskeleton in different sites of the same cells. © 1993 Wiley-Liss, Inc.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970250103
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  • 3
    Electronic Resource
    Electronic Resource
    Motility, cell shape, and locomotion of neutrophil granulocytes (1983)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 3 (1983), S. 47-60 
    Details
    ISSN: 0886-1544
    Keywords: neutrophil granulocytes ; motility ; locomotion ; cell-shape ; cell-substratum adhesion ; f-Met-Leu-Phe ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Activation of the motile apparatus by chemokinetic factors cannot be reliably assessed in cells that are attached to a solid substratum because motility can be totally abolished by excessive adhesion. It is however, necesary to quantify the activation of the motile apparatus in order to analyze and understand chemokinetic responses.It was the purpose of the present work to establish morphological criteria that can be used to quantify motility in nonadherent (floating) neutrophils and to predict the locomotor response under conditions of limited adhesion. The proportion of neutrophils performing crawling-like movements (polarized cells) in suspension correlates very closely with stimulated locomotion at low to optimal concentration of f-Met-Leu-Phe, ie, under conditions of limited adhesion. Reduced locomotion at supraoptimal concentrations of f-Met-Leu-Phe has also morphological correlates. The major feature is the decrease in the proportion of neutrophils performing crawling-like movements and the corresponding appearance of cells that are motile but not polarized in suspension and that do not locomote on the substratum. Concentration-dependent changes in neutrophil length and in the proportion of polarized neutrophils with and without tail were also observed. The locomotor potential of neutrophils under conditions of limited contact with the substratum can be predicted on the basis of their motile behavior, in particular the proportion of cells showing crawling-like movements, in suspension. In combination with measurements of adhesion the procedure should permit a more complete analysis of the regulation of chemokinetic responses.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970030105
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  • 4
    Electronic Resource
    Electronic Resource
    Orthokinetic and klinokinetic responses of human polymorphonuclear leucocytes (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 447-461 
    Details
    ISSN: 0886-1544
    Keywords: chemokinesis ; orthokinesis ; klinokinesis ; polymorphonuclear leucocytes ; locomotion ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Evidence is presented to show that klinokinesis, which was previously demonstrated in bacteria and amoeba only, may also occur in metazoan cells. The chemotactic peptide formyl-Met-Leu-Phe (fMLP) elicited orthokinetic and klinokinetic responses of human blood-borne polymorphonuclear leucocytes (PMNs) under the test conditions used. Increased speed (orthokinesis) was due to an increase in the proportion of migrating cells as well as in the speed of the locomoting subset. The klinokinetic effect was manifested by a decrease in the klinolocomotion index, the mean angle of changes in direction ≥ 90°, and the frequency of turns ≥ 90°. The klinolocomotion index was inversely related to speed. This explains the synergistic effect of klinokinesis and orthokinesis in this system. Colchicine alone had and orthokinetic effect which was exclusively due to alterations in the proportion of migrating cells and it altered the turning behaviour without exerting a klinokinetic effect. However, colchicine had marginal orthokinetic and klinokinetic effects on fMLP-stimulated cells resulting in reduced translocation. The relationship between klinokinesis and mean angle or frequency of turns has been analysed. Klinokinesis was a substantial though not the major element of the chemokinetic response to fMLP under the conditions used. No other metazoan cells have been shown to possess such a complete pattern of responses, including orthokinesis, klinokinesis, and chemotaxis, which regulate locomotion.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970050603
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