摘要:

AbstractThe Bioengineering Center at Wayne State University uses universal blood and body fluid precautions when handling human cadavers in bio‐mechanical testing. Our infection control protocol largely follows the precautions outlined by the Centers for Disease Control (CDC). In addition, we screen each cadaver for the human immunodeficiency virus (HIV) and the hepatitis B virus (HBV) before accepting a cadaver for biomechanical tests. This paper discusses acquired immunodeficiency syndrome (AIDS) and infection control guidelines by addressing the following: (a) what is AIDS? (b) How infectious is the HIV virus, which causes AIDS? (c) What precautions should be taken in cadaveric testing to safeguard against HIV and other bloodborne pathogens? The infection control procedures presented in this paper can be adapted to whole‐body cadaveric testing or to the testing of tissue specim

ISSN:0736-0266    

DOI:10.1002/jor.1100080202

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractThe most common problem following primary flexor tendon repair is the failure of the tendon apparatus to glide, secondary to the formation of adhesions. Early motion following tendon repair has been shown to be effective in reducing adhesions between the tendon and the surrounding sheath. Therefore, it is important to determine the amount of flexor tendon excursion along the digit during joint motion. In this study, the excursion between the flexor digitorum profundus (FDP) tendon and the sheath was examined in both human and canine digits. Based on roentgenographic measurements and joint kinematic analysis, the motion of the bones, the FDP tendon, and the sheath were measured with respect to joint rotations. It was found that the canine flexor tendon apparatus behaved similarly to that of the human for the motions studied. The amount of tendon excursion was very small in regions distal to the joint in motion (approximately 0.1 mm/10° of joint rotation). There was little displacement of the sheath (0.2–0.3 mm), except at the metacarpal joint region during metacarpophalangeal (MCP) joint motion and at the proximal interphalangeal (PIP) joint region during PIP joint motion. Tendon excursion relative to the tendon sheath was the largest in zone II during PIP joint rotation (1.7 mm/10° of joint rotation). These results suggest that PIP joint motion may be most effective in reducing adhesions following tendon repair in zone

ISSN:0736-0266    

DOI:10.1002/jor.1100080203

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractThe healing of a standardized defect of the supraspinatus tendon in a time‐related series on rabbits was monitored with arthrography and simultaneous determination of the intra‐articular hydrodynamic pressure of the glenohumeral joint. All normal glenohumeral joints produced a biphasic pressure versus volume curve. Rupture of a normal glenohumeral joint occurred at a pressure level of 140–170 mm Hg and was located in the area around the biceps tendon sheath. In joints with a defect of the supraspinatus tendon, leakage of the contrast medium was evident up to the sixth week, at an intra‐articular pressure varying from 40 to 100 mm Hg. After week 6, no leakage of the cuff was seen during the determination of the intraarticular pressure. This was in accordance with the histological findings: the defect was covered with solid scar tissue from the ninth week onward. Resistance to hydrodynamic intra‐articular pressure proved a reliable method of determining the strength of the healing of the supraspina

ISSN:0736-0266    

DOI:10.1002/jor.1100080204

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractThe anterior cruciate ligaments (ACL) of dogs, humans, and rabbits were studied by light and scanning electron microscopy after fixation in situ. In all species, the ACL was composed of multiple 20 μm‐wide collagen fiber bundles separated by columns of cells in fibrous capsules. These bundles were in turn grouped into fascioles of varied size. The fascicles were surrounded by thin membranous sheets that ran through the ligament forming single or multiple layers between fascicles. Splaying of the ACL at insertion was created by increased volume in the cellular intervals. Bending of the fiber bundles occurred in this region—which corresponds to the fibrocartilaginous zone. We propose that the cell layers accommodate compressive forces and the membranes allow slipping among fascicles without compromising blood su

ISSN:0736-0266    

DOI:10.1002/jor.1100080205

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractAlthough the in vitro interactions between purified cartilage matrix components have been studied extensively, little is known about these interactions in situ. In this study, cartilage was treated with a cross‐linking reagent with a span of 1.2 nm between its reactive terminal groups in order to preserve the native relationships between closely associated matrix components throughout extraction, purification, and preparation for electron microscopy. After in situ cross‐linking, electron microscopy and gel chromatography revealed that about one‐half of the guanidine hydrochloride extractable proteoglycans were polymeric, usually with two to five proteoglycan subunits in each polymer. Cross‐linking consistently involved the thin segments of the proteoglycan subunits. Some of the proteoglycan polymers were capable of binding hyaluronic acid and were parts of aggregates under associative conditions. SDS–polyacrylamide gel electrophoresis revealed that link proteins were present within the polymers, and studies in which purified proteoglycans were cross‐linked in vitro confirmed that the link proteins increased the proportion of polymeric proteoglycans. These findings suggest that individual proteoglycans within cartilage have intimate associations with other proteoglycans that are mediated by li

ISSN:0736-0266    

DOI:10.1002/jor.1100080206

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractThe effect of the two antineoplastic drugs, Adriamycin and methotrexate, on orthotopic bone, and on the induction of experimental heterotopic bone in rats was analyzed. The drugs were administered as single injections: Adriamycin in s.c. doses of 0.5 and 2 mg/kg body weight and methotrexate i.v. 100 and 250 mg/kg body weight followed by leucovorin rescue after 2 h. A passing, but significant, decrease in body weights occurred in the methotrexate‐treated animals, but not in those given Adriamycin. Analysis of the amount of heterotopic bone formed 4 weeks after induction by demineralized bone matrix revealed a 30–40% decrease in the groups treated with either of the antineoplastic agents, whereas orthotopic bone was unaffected. Six weeks after the treatment the net effect on the induced bone had decreased. The present study shows that the two antineoplastic drugs Adriamycin and methotrexate inhibit heterotopic new bone formation induced by demineralized bone matrix in rats to an equal extent, although their mode of action on the cellular level is entirely different, and that the inhibitory effect of a single treatment diminishes in the presence of a continuous inductive proc

ISSN:0736-0266    

DOI:10.1002/jor.1100080207

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractThe purpose of the present study was to investigate regulatory mechanisms for subchondral bone blood flow. A model including elevation of joint cavity pressure in the immature dog knee was applied. The role of prostaglandins in bone blood flow regulation was indirectly examined by indomethacin blockade. In six puppies, both venous tamponade of the joint cavity [50% of the mean arterial blood pressure(MAP)] and arterial tamponade (150% of MAP) resulted in a significant increase in the intraosseous pressure of the distal femoral epiphyses (p<0.05). During venous tamponade no changes were registered in pO2, pCO2, pH, potassium, and lactate in blood withdrawn from the distal femoral epiphyses. Arterial tamponade resulted in hypoxia, a decrease in pH, and increased lactate. Inhibition of the prostaglandin synthesis did not alter this response pattern. Thus, the present study suggests the presence of a regulatory mechanism for subchondral bone blood flow since venous tamponade did not significantly alter intraosseous gas tensions, pH, lactate, or potassium in spite of elevated venous outlet resistance. The study does not allow any conclusion as to the exact nature of the regulatory mechanism, but local metabolic regulation is likely to be involved as indicated by accumulation of vasoactive substances at higher tamponade levels. Prostaglandins are probably of minor importance in this regulation.

ISSN:0736-0266    

DOI:10.1002/jor.1100080208

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractThe effect of the bisphosphonate dichloromethylene biphosphonate (Cl2MBP) on orthotopic and heterotopic bone, induced by implants of demineralized bone matrix (DBM) in rats was analyzed, with special reference to bone resorption. The heterotopic bone was formed by induction for 3 weeks; at this time, the rats were given daily subcutaneous injections of 3 mg/kg of body weight of Cl2MBP or saline, until sacrifice. Prior to the start of treatment, the animals were given45Ca and [3H]proline to label the inorganic and organic components of bone, respectively. Groups of rats were sacrificed at intervals from 1 to 31 days after isotope injection, and the net formation of bone and the elimination rates of the two isotopes were studied in the heterotopic bone, in diaphyseal and metaphyseal bone, and in teeth. The treatment with Cl2MBP caused a doubling of the daily net increase in mineral of the induced heterotopic bone, and a less pronounced increase in the ash content of tibiae. The treatment decreased the elimination rates of both isotopes in the orthotopic and heterotopic bone, showing that decreased bone resorption is the cause of the increased net bone formation.

ISSN:0736-0266    

DOI:10.1002/jor.1100080209

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractA controversy has developed around the question as to whether bone density values from the distal radius can be used to accurately predict risk of future fractures. To address this question, two separate studies were undertaken: (a) Bone density was measured in 460 healthy ambulatory women living in retirement centers in the state of North Carolina; 83% of these women were followed for up to 60 months for occurrence of minimal trauma hip and wrist fractures. Thirty‐one minimal trauma fractures were reported in our study population, representing 8% of those followed. The fracture incidence density rate‐showed a close inverse relationship with incremental changes in bone density at the distal site. Twenty‐eight of the 31 fractures were reported in women with bone density values below the 325‐mg/cm2“at risk” value. (b) Bone density values of the distal radius and the lumbar spine from 360 women (aged 18–85 years) from the Chapel Hill area were used to analyze the error in predicting individual spinal density from the distal radial density. Although the overall correlation was high (r= 0.67) and the confidence intervals were narrow, the prediction intervals were quite wide. Thus, prediction of an individual value of spine density from the distal radius density would result in a value with a range too wide to be clinically useful. We conclude that singlephoton absorptiometry appears to be a useful tool for screening normal populations of asymptomatic women for prediction of hip or Colles' fracture risk or individual values for s

ISSN:0736-0266    

DOI:10.1002/jor.1100080210

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractThis paper reports the effects of adding partially purified bovine thyroid calcitonin, thyrocalcitonin, to adult bovine articular cartilage cells. Thyrocalcitonin stimulated chondrocyte proliferation fourfold under low serum (0.5%) culture conditions. In serum‐free medium, thyrocalcitonin stimulated cell proliferation more than twofold. With high‐density cultures in serum‐free medium, chondrocyte glycosaminoglycan (GAG) synthesis was stimulated 60% by thyrocalcitonin. Cell‐associated radioactivity was increased twofold. In contrast to thyrocalcitonin, addition of human and salmon calcitonin peptides as well as the thyroid hormones T3and T4had no effect on adult cartilage cell proliferation or GAG synthesis. The data reported here suggest the existence of a thyroid‐derived factor, independent of calcitonin peptides or thyroid hormones, which stimulates adult articular chondrocyte m

ISSN:0736-0266    

DOI:10.1002/jor.1100080211

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY