bluuebunny/crossref_metadata_2025_split huggingface dataset:
An in vitro study of anterior cruciate ligament strain induced by quadriceps and hamstrings forces
Authors: Draganich L. F. , Vahey J. W. 
Published: February 2005

AbstractStrain in the anteromedial fibers of the anterior cruciate ligament [ACL(am)] was studied in six cadaver knees. ACL(am) strain was measured in five knees during the application of isometric quadriceps forces alone and simultaneously applied isometric quadriceps and hamstrings forces at 10° increments from 0° to 90° of knee flexion. ACL(am) strain during muscle loading was measured with respect to the ACL(am) strain measured with the knee in its resting position (neutral or near neutral position). A sixth knee was used to investigate the reproducibility of the resting position and quadriceps‐induced ACL(am) strains. The strains induced in the ACL(am) by the quadriceps were significantly greater than 0 at knee flexion angles from 0 to 40° and not significantly different from 0 for 50 to 90° The ACL(am) strains induced by simultaneously applied hamstrings and quadriceps forces were not significantly different from 0 at any of the knee flexion angles tested. Simultaneously applied hamstrings and quadriceps forces significantly reduced ACL(am) strain at 10, 20, and 90° of knee flexion compared to the ACL(am) strain induced by quadriceps forces alone. The hamstrings are potentially capable of both significantly reducing and negating quadriceps‐induced ACL(am) strain at 10 and 20° of knee flexion.
The effect of maturation and aging on the structure and content of link proteins in rabbit articular cartilage
Authors: Flannery Carl R. , Urbanek Paul J. , Sandy John D. 
Published: February 2005

AbstractWe have examined extracts of articular cartilage from rabbits aged 3–100 weeks for evidence of age‐related changes in the structure and content of link protein (LP) in this tissue, with the following findings: (a) Two major molecular weight forms of LP were seen on SDS–PAGE (41 and 48 kDa) and the proportion of these changed markedly with age. The 48 kDa species was predominant in young animals (representing about 78% of the total LP at 5 weeks) whereas the 41 kDa species increased in amount with age (representing 35% of the total LP at 100 weeks). A minor form of about 43 kDa, representing less than 20% of the total, was present only during the growth phase. A small amount of fragmented link protein (less than 5% of the total) of about 25–30 kDa was present in samples from mature and aged rabbits only. (b) The quantitation of LP in guanidinium: HCl extracts of cartilage, by radioimmunoassay with monoclonal antibody 8‐A‐4, was markedly influenced by the conditions of preparation and pretreatment of samples. Assays of dialyzed guanidine extracts following treatment at 80°C for 15 min in 0.025% (w/v) SDS indicated that immature and mature cartilage contains about 50 and 180 μg of LP/g of tissue, respectively. On the other hand, assays following treatment at 100°C for 20 min in 0.1% (w/v) SDS suggested that rabbit cartilage contains about 300 μg of LP/g of tissue at all ages; finally, assay of CsCl purified proteoglycan samples under these conditions indicated a content of about 500 μg of LP/g at all ages. (c) Calculations based on the analysis of proteoglycan preparations for aggregating monomer and link protein suggest that a LP:aggregating monomer molar ratio of about 0.9 is maintained in the articular cartilage throughout maturation and aging in the rabbit.
Is longitudinal bone growth influenced by diurnal variation in the mitotic activity of chondrocytes of the growth plate?
Authors: Stevenson Sharon , Hunziker Ernst B. , Herrmann Wolfgang , Schenk Robert K. 
Published: February 2005

AbstractThe diurnal variations in the mitotic index, height, and rate of linear bone growth were determined and correlations between these parameters examined. Young, unweaned, female Wistar rats were housed under standardized conditions, labeled with a fluorochrome 60 h before sacrifice, and killed at intervals throughout a 24‐h period, specifically 0600, 1200, 1800, and 2400. The proximal tibial epiphyseal growth plates were collected and processed, and the mitotic index, growth plate height, and the rate of linear bone growth were measured. The mitotic index measured at 0600 was significantly higher than that measured at 1800 and 2400. Growth plates of rats sacrificed at 1200 were taller than those of rats sacrificed at 1800, but there was no difference between heights of growth plates from rats sacrificed at other times. Daily growth rate for all rats averaged 283.9 μm/day and there were no statistically significant differences between daily growth rates measured at any time period. Our findings imply that in comparative, quantitative structual studies of animal groups, sacrifice should be carried out at identical times of the day, since, given a constant speed of vascular ingrowth and diurnal variation in width, relative diurnal accumulation and depletions of cells may take place. We also suggest that the daily growth rate and mitotic index be measured directly and not be considered a function of the height of the growth plate.
Nonhuman primate bites
Authors: Janda David H. , Ringler Daniel H. , Hilliard Julia K. , Hankin Rebecca C. , Hankin Fred M. 
Published: February 2005

AbstractNonhuman primate (monkey) bites to researchers and attending animal care staff may present problems in patient management. Such inoculations can transmit serious bacterial and viral infections to the human handlers. Significant local and systemic manifestations can subsequently develop following such an injury. Since Herpesvirus simiae (B virus) is enzootic in Asiatic monkeys of the genus Macaca, and since B virus infection in humans is usually fatal, additional prophylactic and therapeutic measures must be taken when persons are bitten by macaque monkeys. Primate bites require early aggressive intervention.
Electromyogram (EMG) recordings from the subscapularis muscle: Description of a technique
Authors: Németh Gunnar , Kronberg Margareta , Broström Lars‐ÅKe 
Published: February 2005

AbstractOperative treatments for recurrent dislocation of the shoulder usually focus on the subscapularis muscle because it is supposed to contribute to the joint stability. It is of clinical interest to record the EMG from the subscapularis muscle in order to interpret its function. The purpose of the present study was to describe a safe and reliable route to reach the muscle, deeply located between the scapula and the thoracic cage, with fine‐wire EMG electrodes. Twenty‐four shoulders were investigated in 12 volunteers. A hypodermic needle containing bipolar fine‐wire electrodes was inserted in the posterior axillary line with the subjects in the supine position, and the arm held in an abducted and externally rotated position. Three criteria confirmed the location of the electrodes: experience of periosteal pain when the needle reached the costal surface of the scapula, drawing‐in of the wires 3–4 cm when the subject adducted his arm, thereby rotating his scapula downward, and raw EMG recorded during typical movements. Additionally, in four shoulders, the electrode location was checked with computed tomography. There were no complications from this technique, and the subjects felt no pain from the fine‐wire electrodes during arm movements. We conclude that the described technique is a safe and reliable method of reaching the subscapularis muscle with EMG electrodes.
Bone resorption in orthotopic and heterotopic bone of dichloromethylene bisphosphonate‐treated rats
Authors: Nilsson Olle S. , Bauer Henrik C. F. , Brosjö Otte , Törnkvist Hans 
Published: February 2005

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 given 45Ca 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.
Update on the use of distal radial bone density measurements in prediction of hip and Colles' fracture risk
Authors: Lester Gayle E. , Anderson John J. B. , Tylavsky Frances A. , Sutton William R. , Stinnett Sandra S. , DeMasi Ralph A. , Talmage Roy V. 
Published: February 2005

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 spinal density.
Stimulation of adult chondrocyte metabolism by a thyroid‐derived factor
Authors: Jones Deryk G. , Smith R. Lane 
Published: February 2005

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 T3 and T4 had 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 metabolism.
Dynamic electromyography. I. Numerical representation using principal component analysis
Authors: Wootten M. E. , Kadaba M. P. , Cochran G. V. B. 
Published: February 2005

AbstractA complete description of human gait requires consideration of linear and temporal gait parameters such as velocity, cadence, and stride length, as well as graphic waveforms such as limb rotations, forces, and moments at the joints and phasic activity of muscles. This results in a large number of interactive parameters, making interpretation of gait data extremely difficult. Statistical pattern recognition techniques can simplify this problem. For this approach to be successful, first it is necessary to reduce the number of interactive parameters to a manageable set. In this study, we present an application of principal component analysis as a means for representing graphic waveforms in a parsimonious manner. In particular, we concentrate on representing the phasic muscle activity recorded using surface electrodes from ten major muscles of the lower extremity of 35 normal subjects during level walking. A 32 point vector is created in which each point of the vector represents the normalized area under the curve of a portion of rectified and smoothed electromyographic signal, expressed as a function of gait cycle. Principal components are computed and the first few weighting coefficients are retained as features to represent the original EMG data. We show that the corresponding basis vectors span parts of the gait cycle where the most variability between individual subjects exists. We also show that the basis vectors can be used to represent the EMG data of subjects not originally used to generate the basis vectors.
Blood flow evaluation of vascularized bone transfers in a canine model
Authors: Siegert John J. , Wood Michael B. 
Published: February 2005

AbstractBlood flow in vascularized bone transfers was evaluated in a canine model. Cortical bone blood flow was determined in undisturbed control bone, vascularized heterotopic bone transfers, and nonvascularized cortical bone grafts by means of the radionuclide‐labeled microsphere technique. Four animals were studied at 2 days, three at 1 week, eight at 2 weeks, four at 4 weeks, and three at 6 weeks postoperatively. In the 2‐day animals, the vascularized bone transfers exhibited intermediate levels of blood flow (1.4 ± 0.4 ml/100 g of bone/min) compared with undisturbed control bone (2.7 ± 0.5 ml/100 g of bone/min) and conventional cortical bone grafts (0.0 ± 0.0 ml/100 g of bone/min). At 1 week postoperatively, the differences in blood flow values of the vascularized transfers (1.7 ± 0.7 ml/100 g of bone/min) and control bone (1.4 ± 1.0 ml/100 g of bone/min) and of the nonvascularized grafts (0.2 ± 0.1 ml/100 g of bone/min) and control bone (1.6 ± 1.1 ml/100 g of bone/min) were no longer significant. At 2 weeks postoperatively, blood flow had increased in both graft groups. At 4 weeks postoperatively, the bone blood flow values in the vascularized transfers (4.8 ± 1.4 ml/100 g of bone/min) were significantly greater than the bone blood flow in control specimens (1.6 ± 0.5 ml/100 g of bone/min) and conventional cortical bone grafts (2.5 ± 2.0 ml/100 g of bone/min). At 6 weeks postoperatively, the bone blood flow values in the vascularized transfers (4.0 ± 2.1 ml/100 g of bone/min) remained greater than the bone blood flow in control specimens (1.7 ± 0.5 ml/100 g of bone/min) and conventional cortical bone grafts (2.5 ± 2.7 ml/100 g of bone/min), but the differences were no longer significant.
Bone blood flow after spinal paralysis in the rat
Authors: Takahashi Hiroshi , Yamamuro Takao , Okumura Hideo , Kasai Ryuichi , Tada Kenji 
Published: February 2005

AbstractThe goal of this study was to investigate the acute and chronic effects of paralysis induced by spinal cord section or sciatic neurotomy on bone blood flow in the rat. Regional bone blood flow was measured in the early stage with the hydrogen washout technique and the change of whole bone blood flow was measured in the early and the late stages with the radioactive microsphere technique. Four to 6 h after cordotomy at the level of the 13th thoracic vertebra, the regional bone blood flow in the denervated tibia increased significantly (p < 0.01). After hemicordotomy with rhizotomy at the same level, the regional bone blood flow in the denervated tibia increased significantly (p < 0.05) 6 h postoperatively. The whole bone blood flow in the denervated tibia had also increased significantly (p < 0.05) at 6 h and at 4 and 12 weeks postoperatively. After sciatic neurotomy, the regional and the whole bone blood flow in the paralytic tibia did not change significantly. The present study demonstrated that monoplegic paralysis caused an increase in bone blood flow in the denervated hind limb from a very early stage. It was suggested that the spinal nervous system contributed to the control of bone blood flow.
Spondylosis in sand rats: A model of intervertebral disc degeneration and hyperostosis
Authors: Moskowitz Roland W. , Ziv Israel , Denko Charles W. , Boja Betty , Jones Paul K. , Adler Jonathan H. 
Published: February 2005

AbstractThis study defines gross, histopathologic, and radiologic changes associated with intervertebral disc degeneration in a spontaneously occurring form of the disease in aging sand rats (Psammomys obesus). Sand rats (male/female) fed lab chow supplemented with desert salt bush were sacrificed at periods of 3‐30 months. Lateral thoracolumbar spine films were obtained. At sacrifice, spines were surgically exposed and gross findings were recorded; after fixation/decalcification, histopathologic studies were carried out using hematoxylin and eosin, and Safranin‐O with fast green counterstain. Metabolic studies included correlations of pathologic and radiologic findings with blood glucose and insulin levels. Disc‐space narrowing and subchondral endplate sclerosis increased radiologically with age, with more severe lower lumbar disc lesions. Ligamentous calcifications ventral to involved discs and caudal vertebrae were common. Disc thinning and anterior vertebral bony/cartilaginous spurs were more marked with age. Microscopy revealed loss of nucleus pulposus physaliform cells, chondrocyte replication, disc necrosis, and ossification. Hyperglycemia with and without hyperinsulinemia was common. No statistically significant differences in pathologic findings were noted, neither in diabetic versus nondiabetic nor in hyperinsulinemic animals. The sand rat is a model of disc degeneration; similarities with possible overlap with diffuse idiopathic skeletal hyperostosis syndrome were noted.
A histological study of local anesthetic‐induced muscle degeneration and regeneration in the monkey
Authors: Carlson Bruce M. , Shepard Beverly , Komorowski Thomas E. 
Published: February 2005

AbstractSmall amounts (1–2 ml) of local anesthetics (bupivacaine, lidocaine, and mepivacaine) were injected into the abductor pollicis brevis muscles of 35 monkeys. Control muscles were injected with saline. The muscles were preserved for histology from 4.5 h to 48 days after the injection. Histological damage to muscle fibers was evident from the time of the first sampling. Invasion of damaged muscle fibers by phagocytic cells was prominent by 2–3 days postinjection. At 4 to 5 days, areas of muscle fiber damage were characterized by dense concentrations of phagocytes and mononuclear myoblastic cells. At 6 days, fields of early myotubes were evident. Maturation of myotubes into immature cross‐striated muscle fibers occurred over the next week. Occasional myotubes or immature regenerating muscle fibers were seen as late as 28 days. The topographical pattern of muscle fiber degeneration and regeneration showed a concentration along the surfaces of muscle fascicles or, if intrafascicular, around the presumed site of injection.
The effects of test environment and cyclic stretching on the failure properties of human patellar tendons
Authors: Haut Roger C. , Powlison Amy C. 
Published: February 2005

AbstractThere is a need to document the mechanical properties of patellar tendon allografts used for reconstructive surgery of the damaged anterior cruciate ligament, especially the effects of irraidiation sterilization. The purpose of this study was to investigate the influences of in vitro test environment and low‐level cyclic stretching prior to failure tests on nonirradiated and irradiated human graft tissues. Bilateral patellar tendons were split and each half processed accordingly. Some graft tissues were stretched cyclically at 2.5 mm deformation before failure. Experiments were performed in a 37°C saline bath or with tissues moistened with a drip of the same. The irradiated grafts relaxed less and generated less slack length in the drip environment than the nonirradiated controls. Cyclic stretching did not alter failure characteristics of either graft tissue. While no significant differences in the tensile responses or failure characteristics were noted for irradiated and nonirradiated grafts in the drip, in the bath environment the nonirradiated tissues had greater strength and modulus. This resulted in there being a significant difference between irradiated and nonirradiated tissue responses in a heated saline bath environment. These experimental results exemplify the need to control in vitro test environments in the evaluation of various sterilization and preservation protocols for soft tissue allografts.
High susceptibility of human articular cartilage glycosaminoglycan synthesis to changes in inorganic sulfate availability
Authors: van der Kraan Peter M. , Vitters Elly L. , de Vries Bernard J. , van den Berg Wim B. 
Published: February 2005

AbstractThe effect of sulfate concentration in the medium on glycosaminoglycan synthesis in articular cartilage of five different species was examined in relation to the physiological serum sulfate concentration in these species. Only the rate of sulfated glycosaminoglycan synthesis in human articular cartilage was sensitive to small deviation from the physiological sulfate concentration. A reduction in the sulfate concentration from 0.3 mM (physiological) to 0.2 mM resulted in a 33% reduction in glycosaminoglycan synthesis. In addition, we studied the effect of arthritic and “osteoarthritic” alterations in murine cartilage on the dependence of glycosaminoglycan synthesis on low sulfate concentrations. Arthritic and “osteoarthritic” cartilage had a similar dependence on the sulfate concentration in the medium as normal cartilage. Glycosaminoglycan synthesis in human articular cartilage appears to be very sensitive to the potential sulfate‐depleting effects of drugs used in the treatment of rheumatoid arthritis and osteoarthritis.
Bone and cartilage changes following experimental varus or valgus tibial angulation
Authors: Wu D. D. , Burr D. B. , Boyd R. D. , Radin E. L. 
Published: February 2005

AbstractThe purpose of this work was to determine whether subchondral bone changes are an integral part of the development of osteoarthrosis of the knee following experimentally created tibial angulation. Thirty degree varus or valgus proximal tibial osteotomies were created in female New Zealand white rabbits. Bone and cartilage changes were assessed grossly, radiologically, and histologically. Thirty‐four weeks following osteotomy, severe cartilage changes, including osteophytes, fibrillation, derangement of cell columns, and cloning, were evident on the overloaded condyle, accompanied by increased subchondral bone density. The pattern of cartilage deterioration was different from that found in other experimental, mechanically induced arthroses. We conclude that osteoarthrosis is a final common pathway for mechanically induced joint failure, and that progressive cartilage change is associated with increased subchondral bone density.