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Biomedical Engineering and Bioengineering Commons™
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Articles 1 - 11 of 11
Full-Text Articles in Biomedical Engineering and Bioengineering
Corrosion Of Metal Hip Arthroplasties And Its Possible Role In Loosening, H. K. Koerten, J. J. A. M. Van Raay, J. J. M. Onderwater, F. P. Bernoski, P. M. Rozing
Corrosion Of Metal Hip Arthroplasties And Its Possible Role In Loosening, H. K. Koerten, J. J. A. M. Van Raay, J. J. M. Onderwater, F. P. Bernoski, P. M. Rozing
Cells and Materials
Tissue removed with human hip arthroplasties during revision surgery of 45 patients was evaluated by transmission electron microscopy and X -ray microanalysis (XRMA). The results show that microscopic and submicroscopic particles are abundantly present in the tissue at the tissue/implant interface. XRMA of individual particles shows that the chemical composition of a portion of the particles was in agreement with that of the retrieved implants. Regularly, particulates with a dissimilar chemical composition were found. Sometimes, these particles could be recognized as filler particles of the cements used. Other particles could partly or completely be composed of the chemical elements that …
Ultrastructural Observations Of Peri-Implant Mucosa Morphology Around Different Types Of Abutment In Humans, C. Piacentini, P. Lanzarini, R. Rodriguez Y Baena, S. Rizzo, C. Brusotti
Ultrastructural Observations Of Peri-Implant Mucosa Morphology Around Different Types Of Abutment In Humans, C. Piacentini, P. Lanzarini, R. Rodriguez Y Baena, S. Rizzo, C. Brusotti
Cells and Materials
Scanning electron microscopy (SFM) and transmission electron microscopy (TEM) were used to examine the morphological aspects of peri-implant mucosa around abutments of differing geometry (biconical and cylindrical) and of differing surface micromorphology. The samples were taken from seven patients who had undergone implant surgery at least one year prior to the study. In samples from biconical abutments, SEM of the sulcular epithelium showed that it consisted of flattened polygonal cells with a surface resembling a honeycomb. Superficial desquamation was rarely found. In contrast, in the samples from cylindrical abutments, the sulcular epithelium showed extensive desquamation and surface irregularity, but not …
Transmission Electron Microscopical Study Of Fibroblast Attachment To Microtextured Silicone Rubber Surfaces, E. T. Den Braber, J. E. De Ruijter, H. J. E. Croes, L. A. Ginsel, J. A. Jansen
Transmission Electron Microscopical Study Of Fibroblast Attachment To Microtextured Silicone Rubber Surfaces, E. T. Den Braber, J. E. De Ruijter, H. J. E. Croes, L. A. Ginsel, J. A. Jansen
Cells and Materials
Cellular attachment has been suggested to be highly influenced by the micromorphology of the substratum surface. To test this hypothesis, smooth and microtextured silicone substrata were produced, which possessed parallel surface grooves with a groove and ridge width of 2.0 (SilD02), 5.0 (SilD05), and 10 µm (SilD10). Groove depth was approximately 0.5 µm. After culture of rat dermal fibroblasts (RDFs) on these substrata for 3 and 5 days, the samples were prepared and sectioned for transmission electron microscopy with a specially developed preparation technique. On the SilD02 and SilD05 surfaces, it was found that the RDFs attached to …
A Microstructural Investigation Of Calcium Hydroxyapatites Synthesized From Cahpo4•2h2o And Ca4(Po4)2o, Kevor S. Tenhuisen, Boyd A. Clark, Maria Klimkiewicz, Paul W. Brown
A Microstructural Investigation Of Calcium Hydroxyapatites Synthesized From Cahpo4•2h2o And Ca4(Po4)2o, Kevor S. Tenhuisen, Boyd A. Clark, Maria Klimkiewicz, Paul W. Brown
Cells and Materials
This investigation determined the effects of reaction temperature and bulk composition on the microstructural features of hydroxyapatites (HAp) synthesized from reaction between particulate CaHPO4·2H2O and Ca4(PO4)2O. These data were used in combination with previous work to further elucidate the mechanistic reaction path taken by these calcium phosphate cements. HAps having two different compositions (Ca/P = 1.50 and 1.67) were synthesized between 15.0 and 70.0°C. All reactions reached completion as indicated by X-ray diffraction. Single point nitrogen absorption was performed on all samples to determine specific surface areas. The HAp which …
Mineralization Of An Axially Aligned Collagenous Matrix: A Morphological Study, D. L. Christiansen, F. H. Silver
Mineralization Of An Axially Aligned Collagenous Matrix: A Morphological Study, D. L. Christiansen, F. H. Silver
Cells and Materials
Bone can be described as a highly ordered composite of type I collagen integrated with an inorganic mineral phase. In vitro models of bone mineralization using collagenous substrates have been reported in the literature. This study reports an in vitro system of mineralized reconstituted collagen fibers, with aligned fibrillar substructure. The collagen fibers were mineralized in a double diffusion chamber saturated with respect to calcium and phosphate. The morphology and ultrastructure of the mineral precipitate were evaluated as a function of the pH of the incubating media. Brushite crystal was observed at acidic pH. Large rectangular crystals formed at pH …
Lysine Effect On Ruthenium Red And Alcian Blue Preservation And Staining Of The Staphylococcal Glycocalyx, Theresa A. Fassel, James R. Sanger, Charles E. Edmiston
Lysine Effect On Ruthenium Red And Alcian Blue Preservation And Staining Of The Staphylococcal Glycocalyx, Theresa A. Fassel, James R. Sanger, Charles E. Edmiston
Cells and Materials
The effect of lysine on ruthenium red (RR) and alcian blue (AB) preservation arid/or staining for transmission electron microscopy of glycocalyces was evaluated for three species of the gram-positive, coagulase-negative staphylococci. A RR and an AB procedure were compared with and without lysine included in the glutaraldehyde prefixation. Minimal or no glycocalyx was preserved or stained by glutaraldehyde fixation only. For all species, the inclusion of lysine increased visualization of fibrous material. RR treatment without lysine, results in sparse or limited fibrous material or artifactual condensations which contrasts with enhanced fibrous material seen when lysine is included with RR. The …
Are Long Term Cryopreservation And Patency Of Vein Allograft Truly Achievable?, G. Pasquinelli, G. L. Faggioli, P. Preda, M. Vici, G. N. Martinelli, R. Giardino, M. D'Addato, J. J. Ricotta
Are Long Term Cryopreservation And Patency Of Vein Allograft Truly Achievable?, G. Pasquinelli, G. L. Faggioli, P. Preda, M. Vici, G. N. Martinelli, R. Giardino, M. D'Addato, J. J. Ricotta
Cells and Materials
Despite extensive experimental work, neither the effect of long term cryopreservation on vein graft architecture nor the failure of alloveins due to graft rejection have yet been investigated. Herein, we investigated ultrastructurally: a) the integrity of rabbit jugular veins following 1, 2 and 3 months of cryopreservation; b) the outcome of the three-month cryopreserved vein auto- and allografts after 1 month of implantation in the rabbit carotid artery; and c) the immunologic response to cryopreserved vein allografts with and without seeded autologous endothelium. Prior to implantation, the cryopreserved rabbit veins were well-maintained except for endothelial cell damage. Following implantation, the …
Evaluation Of Bacterial Glycocalyx Preservation And Staining By Ruthenium Red, Ruthenium Red-Lysine And Alcian Blue For Several Methanotroph And Staphylococcal Species, Theresa A. Fassel, James E. Van Over, Christopher C. Hauser, Lorie E. Buchholz, Charles E. Edmiston, James R. Sanger, Charles C. Remsen
Evaluation Of Bacterial Glycocalyx Preservation And Staining By Ruthenium Red, Ruthenium Red-Lysine And Alcian Blue For Several Methanotroph And Staphylococcal Species, Theresa A. Fassel, James E. Van Over, Christopher C. Hauser, Lorie E. Buchholz, Charles E. Edmiston, James R. Sanger, Charles C. Remsen
Cells and Materials
The cationic reagents, ruthenium red (RR), alcian blue (AB) and ruthenium red -lysine were compared for ultrastructural preservation and staining of the bacterial glycocalyx. En bloc RR, AB and RR-lysine procedures, and a glutaraldehyde/OsO4 fixation withou t cationic reagent, were evaluated by transmission electron microscopy (TEM) for several methanotroph and staphylococcal species. The glutaraldehyde/OsO4 fixation was totally ineffective in preserving or staining the glycocalyx material in all species studied. The RR procedure was more effective than the glutaraldehyde/OsO4 fixation but was generally less so than the RR-lysine procedure. By the RR-lysine procedure, extensive layers that were often filamentous or fibrous …
A Model For A Model: Pressure Jackets On Nude Mice With Implants Of Hypertrophic Scars, C. Ward Kischer, Jana Pindur
A Model For A Model: Pressure Jackets On Nude Mice With Implants Of Hypertrophic Scars, C. Ward Kischer, Jana Pindur
Cells and Materials
The hypertrophic scar, a consequence of deep surface injury, is peculiar to humankind. Subcutaneous implants of these tissues in nude mice provide a quasi - animal model for experimental use. An efficacious treatment to promote acceleration of maturation of the hypertrophic scar is controlled topical pressure produced by flexible dacron fabric wraps. Implants in the nude mouse provide a model for study of the effects of pressure. Preliminary results indicate that those implants in nude mice, responding favorably to pressure jackets, show changes consistent with those previously obtained in human studies. The collagen matrix shows reduced density and parallel layering …
Investigation On The Collagen Fiber Network In Human Dental Tissues - Transmission And Scanning Electron Microscopy, C. Marchetti, P. Menghini, C. Piacentini
Investigation On The Collagen Fiber Network In Human Dental Tissues - Transmission And Scanning Electron Microscopy, C. Marchetti, P. Menghini, C. Piacentini
Cells and Materials
The collagen fiber component of pulp, dentine and cementum, has been studied by isolating it from the inorganic component and the organic non-collagen matrix. This study was carried out on healthy molar and premolar adult teeth. Following demineralization all of the non-collagenous components of the tooth were removed by sequential treatment with H202, with different concentrations of trypsin and with EDTA. The transmission (TEM) and scanning (SEM) electron microscopy investigation confirmed that such a technique is an accurate method for isolating the collagen fibers while preserving their position and their ultrastructure in the dental tissue. The use of TEM and …
Preservation Of The Cell-Biomaterial Interface At The Ultrastructural Level, J. M. Schakenraad, J. A. Oosterbaan, E. H. Blaauw
Preservation Of The Cell-Biomaterial Interface At The Ultrastructural Level, J. M. Schakenraad, J. A. Oosterbaan, E. H. Blaauw
Cells and Materials
Studying the tissue-biomaterial interface at the ultrastructural level is not without problems. Dissolution of the biomaterial in one of the dehydration or embedding media causes holes and shatter during sectioning or dislodgement of the biomaterial. The fine tuning of the hardness of both biomaterial and embedding medium, as well as the introduction of butyl-2,3- epoxypropylether as an intermediate between the dehydration series and the Epon resin , improving the impregnation , will solve many of the problems mentioned. With this improved technique good results were obtained with materials ranging from teflon, poly(Lactic acid) and polyurethanes to tissue culture polystyrene. No …