摘要:

AbstractNondestructive and destructive uniaxial load tests were performed on natural and chemically modified bovine pericardium. Five specimens were selected from the same sites in different pericardial sacs by using a template. The mean maximum extension of one particular site in both the natural and chemically modified material was significantly greater than that of the other positions at a stress level of 0.6 Nmm.−2The maximum extensibility of the fixed tissue was significantly greater (p<0.01) than that of the natural tissue. There was also an anatomical variation in tensile strength of the natural material which was retained after chemical modification. However, the overall tensile strength of the pericardium was not increased by this procedure. In contrast, glutaraldehyde fixation did increase the percentage strain at which fracture of this biomaterial occurre

ISSN:0021-9304    

DOI:10.1002/jbm.820220202

出版商:John Wiley&Sons, Inc.    

年代:1988

数据来源: WILEY

摘要:

AbstractThis study demonstrates the usefulness of an enzyme linked immunosorbent assay (ELISA) for detection and quantification of protein on the surface of materials. Bovine serum albumin (BSA) and bovine gamma globulin (BGG) were the proteins used. Titanium and stainless steel were the materials tested. The proteins were detected with the use of rabbit antiserum specific for BSA and for BGG. This reaction was quantitated by the use of horseradish peroxidase conjugated goat anti‐rabbit gamma globulin. The technique is described in detail. The technique was demonstrated to be suitable for quantitation of protein from 0.01 mg/mL to 0.1 mg/mL on the surface of 3 mm × 10 mm materials. The technique was also demonstrated to be suitable for determining the surface area of solid materials. It is a simple technique and suitable for most biomaterials laboratori

ISSN:0021-9304    

DOI:10.1002/jbm.820220203

出版商:John Wiley&Sons, Inc.    

年代:1988

数据来源: WILEY

摘要:

AbstractThe objectives of this study were to determine the effect of proteins and protein charge on the corrosion of stainless steel. As Zwitter ions, proteins have a positive charge in solutions acidic to their isoelectric point (pI) and a negative charge in solutions basic to the pI. Fretting corrosion rates of stainless‐steel plates and screws as determined by weight loss and metal ion release were studied in saline and protein solutions with the pH adjusted to 3, 5, and 8. Alterations in pH did not affect the corrosion rate in saline solutions. However, alterations of the pH in albumin solutions did affect the corrosion rate. In protein solutions acidic to the isoelectric point the presence of the positively charged albumin did not alter the corrosion rates as compared to that in saline. However, the presence of negatively charged proteins in solutions basic to their isoelectric points decreased the amount of corrosion. Thus, the effect of proteins on fretting corrosion is dependent on the charge on the protein. When the release of nickel was compared to the release of chromium, it was shown that the release was in proportion to the composition of the alloy when fretting corrosion took place in saline. The nickel/chromium ratio in the albumin and gamma globulin solutions was increased relative to that predicted indicating preferential release of nickel in protein solution

ISSN:0021-9304    

DOI:10.1002/jbm.820220204

出版商:John Wiley&Sons, Inc.    

年代:1988

数据来源: WILEY

摘要:

AbstractThis study examined the hypothesis that healing within porous implants differs from that in normal connective tissue. Special attention was given to extracellular components including collagen, reticular fibers, and ground substance, and to enzymes associated with activated macrophages. Using Dacron velour and the rabbit as host, the healing of normal connective tissue and that of the tissue/implant interface were histologically compared 10 and 28 days postimplantation. The results exhibited significant differences between connective tissue healing, implant capsule formation, and granulation tissue generation. The healing of connective tissue and implant capsule formation were essentially complete at 28 days. However, tissue inside the implant was qualitatively different and did not significantly change between 10 and 28 days. It was characterized by macrophages and giant cells, a predominantly acid mucopolysaccharide ground substance, and qualitatively fewer and less well defined collagen and reticular fibers were observed than in normal wound healing. Thus we conclude that the connective tissue inside Dacron velour does not resemble normal connective tissue after 10 or 28 days of healing. Furthermore, the collagen never fully matures into orderly bundles, a phenomenon which may be related to an altered mucopolysaccharide composition and a diminished reticular network. The lysosomal enzymatic activity of the macrophages and perhaps the giant cells at the tissue/implant interface may be linked to these differences.

ISSN:0021-9304    

DOI:10.1002/jbm.820220205

出版商:John Wiley&Sons, Inc.    

年代:1988

数据来源: WILEY

摘要:

AbstractStudies have shown synthetic calcium phosphates such as hydroxyapatite and beta tricalcium phosphate to be biocompatiblein vivo. However, few studies have quantitated histological responses to the implants.The aim of this study was to develop a method for the quantitative assessment of tissue biocompatibility to ceramic materialsin vivoand to use this method to compare noncarbonated and carbonated apatite implants. Synthetic sintered apatites of 0, 3, and 6% carbonate by weight were prepared and cut into implants 4 × 4 × 1 mm. These were placed 2 mm into the medial aspect of rat fermurs. Following sacrifice at 4 weeks, the femurs were fixed in formalin, demineralized in formic acid, and embedded in glycol methacrylate. Sections were cut on an ultramicrotome set at 1.5 μm and stained with toluidine blue. A point counting technique using standard stereological grids and a low‐power microscope was used to measure areas of new bone formation. The width of the connective tissue zone adjacent to muscle was measured using an image analyzer. All implants were well accepted by the host tissues judging from criteria of minimal inflammation and degree of fixation. Results showed an increase in new bone formed in the marrow cavity with increasing carbonate content. This may improve stability of the implant in the host bone, particularly during the initial healing period. A technique which should enable quantitative histological evaluation of different ceramic materials has been developed. The use of this method indicates that further studies are warranted to investigate carbonated apatite as an implant mate

ISSN:0021-9304    

DOI:10.1002/jbm.820220206

出版商:John Wiley&Sons, Inc.    

年代:1988

数据来源: WILEY

摘要:

AbstractAnin vitromethod has been developed for human non‐anticoagulated blood to evaluate the enhancing effect of hemostatic agents on both plasmatic and cellular activation of the coagulation cascade. The coagulation time and the sequential generation of fibrinopeptide A (FpA) have been used as parameters. The kinetics of generation of FpA has been modelized and mathematically analyzed using the latence time, the slope of the linear part of the curve, and the time necessary to reach half maximal amplitude of FpA in the tube. A very precise evaluation of the hemostatic activity of five different molecules, four being collagenous in nature, is give

ISSN:0021-9304    

DOI:10.1002/jbm.820220207

出版商:John Wiley&Sons, Inc.    

年代:1988

数据来源: WILEY

ISSN:0021-9304    

DOI:10.1002/jbm.820220208

出版商:John Wiley&Sons, Inc.    

年代:1988

数据来源: WILEY

ISSN:0021-9304    

DOI:10.1002/jbm.820220201

出版商:John Wiley&Sons, Inc.    

年代:1988

数据来源: WILEY