bluuebunny/crossref_metadata_2025_split huggingface dataset:
Colony‐forming efficiency response of bone marrow stromal cells to acute blood loss
Authors: Lippiello L. , Chavda D. , Connolly J. 
Published: February 2005

AbstractColony‐forming efficiency (CFE) was used to monitor the proliferative response of alkaline phosphatase‐positive rabbit bone marrow stromal cells to acute blood loss. The CFE of animals subjected to a 1% blood loss was 0.97 compared with 0.06 (p < 0.01) in nonbled animals. Sera obtained from animals 10 days after an initial blood loss stimulated the CFE of marrow cultures from nonbled donors to the same degree as osteogenin. Erythropoietin and control sera (from nonbled animals) had no effect. Hence, acute blood loss and sera from bled animals stimulate proliferation of alkaline phosphatase‐positive marrow stromal cell colonies. The agent(s) responsible is unknown but it is present in serum in response to blood loss. Confirmation of a specific effect on osteoprogenitor cells may warrant the designation “osteopoietin”.
The early effects of joint immobilization on medial collateral ligament healing in an ACL‐deficient knee: A gross anatomic and biomechanical investigation in the adult rabbit model
Authors: Bray R. C. , Shrive N. G. , Frank C. B. , Chimich D. D. 
Published: February 2005

AbstractIn this study, the short‐term effects of immobilization on joint damage and medial collateral ligament (MCL) healing were investigated in unstable, anterior cruciate ligament (ACL)‐deficient knees in rabbits. Forty‐six 12‐month‐old female New Zealand white rabbits were separated into three groups. Animals from each group had surgery on their right knees: group I, sham controls (n = 9); group II, complete transection of the ACL and removal of a 4 mm segment (gap injury) of MCL midsubstance with no immobilization of the limb (n = 19); and group III, same injuries to the ACL and MCL (as group II) but with immobilization of the limb (n = 18). No surgical repair of disrupted ligaments was performed. Left knees served as unoperated contralateral controls. All animals were allowed unrestricted cage activity until sacrifice in subgroups at 3, 6, and 14 weeks of healing when biomechanical properties of all MCLs were measured. All knee joints were systematically examined for gross evidence of damage to articular cartilage, menisci, and periarticular soft tissues. To monitor relative in vivo loads on injured limbs during healing, hind‐limb weight bearing was assessed at biweekly intervals. Results indicate that animals in both groups II and III bore relatively lower loads (compared to preinjury values) on their injured hindlimbs. Mechanical testing of MCLs showed only minor changes in sham controls, while group II and III healing MCLs demonstrated significantly lower force and stress at MCL complex failure compared to contralateral controls. In specific comparisons of group III to group II animals, we noted that immobilization prevented joint damage over the early intervals studied. In addition, immobilization resulted in MCL laxity similar to contralateral control values but inhibited development of structural strength and stiffness in healing MCLs. These results suggest that in the rabbit, short‐term immobilization of an ACL‐deficient knee offers some advantages to the joint and to certain low load behaviors of the healing MCL, but it also results in a smaller quantity of scar tissue that is less able to resist higher loads. Longer‐term studies involving remobilization are necessary before the effects of brief immobilization on joint damage and MCL healing in this ACL‐deficient model can be fully defined.
Strain in the anteromedial bundle of the anterior cruciate ligament under combination loading
Authors: Berns Gregory S. , Hull M. L. , Patterson Hugh A. 
Published: February 2005

AbstractStrain within the anteromedial bundle (AMB) of the anterior cruciate ligament (ACL) was measured in 13 human knee specimens in order to determine the combination of external loads most likely to cause injury. Using a load application system that allowed 5 df with the flexion angle being fixed, pure loads of anterior/posterior force, medial/lateral force, varus/valgus torque, and internal/external axial torque were applied at three flexion angles: 0°, 15°, 30°. Combined loads were applied in pairs at two flexion angles: 0° and 30°. Liquid mercury strain gauges were used to measure strain in the ACL. Anterior tibial force was the primary determinant of strain in the anteromedial bundle. This strain was significantly larger at 30° flexion than at 0°. The strain sensitivity of the AMB to medial force was approximately one‐half that to pure anterior force. The effect of anterior and medial forces was additive when applied in combination. Neither pure axial torque nor pure varus/valgus torque was observed to strain significantly the AMB at any of the flexion angles investigated. However, valgus torque in combination with anterior force resulted in a significantly larger strain than pure anterior force. Internal axial torque in combination with anterior force also resulted in a larger strain than pure anterior force.
Tensile properties of the inferior glenohumeral ligament
Authors: Bigliani Louis U. , Pollock Roger G. , Soslowsky Louis J. , Flatow Evan L. , Pawluk Robert J. , Mow Van C. 
Published: February 2005

AbstractThe tensile properties of the inferior glenohumeral ligament have been determined in 16 freshly frozen cadaver shoulders. The inferior gleno‐humeral ligament was divided into three anatomical regions: a superior band, an anterior axillary pouch, and a posterior axillary pouch. This yielded 48 bone‐ligament‐bone specimens, which were tested to failure in uniaxial tension. The superior band was consistently the thickest region, averaging 2.79 mm. The thickness of the inferior glenohumeral ligament decreased from antero‐superiorly to postero‐inferiorly. The resting length of all three anatomical regions was not statistically different. Total specimen strain to failure for all bone‐ligament‐bone specimens averaged 27%. Variations occurred between the three regions, with the anterior pouch specimens failing at a higher strain (34%) than those from the superior band (24%) or the posterior pouch (23%). Strain to failure for the ligament midsubstance (11%) was found to be significantly less than that for the entire specimen (27%). Thus, larger strain must occur near the insertion sites of the inferior glenohumeral ligament. Stress at failure was found to be nearly identical for the three regions of the ligament, averaging 5.5 MPa. These values are lower than those reported for other soft tissues, such as anterior cruciate ligament and patellar tendon. The anterior pouch was found to be less stiff than the other two regions, perhaps suggesting that it is composed of more highly crimped collagen fibers. Three failure sites were seen for the inferior glenohumeral ligament: the glenoid insertion (40%), the ligament substance (35%), and the humeral insertion (25%). In addition, significant capsular stretching occurred before failure, regardless of the failure mode.
Physicochemical properties of the aging and diabetic sand rat intervertebral disc
Authors: Ziv I. , Moskowitz R. W. , Kraise I. , Adler J. H. , Maroudas A. 
Published: February 2005

AbstractHydration, fixed charge density, (FCD) and hydration under various osmotic pressures were compared in young, old, and young diabetic sand rats. This rat is a desert animal that may develop diabetes when fed a regular diet; it is also known to have radiographic and histologic evidence of intervertebral disc (IVD) disease. Forty‐five rats and 180 IVD were used in this study; they were divided into three equal groups: young healthy, old healthy, and young diabetics. IVD, cancellous bone, and muscle were sampled from distal lumbar spines. The young diabetic rats (YD) were considerably heavier than the age‐matched controls, had higher insulin and glucose levels, and all YD had cataracts. The discs of the young diabetic animals demonstrated decreased hydration, FCD and ability to resist compression under osmotic pressures as compared with the young and healthy discs and were more similar to the discs from old rats. The IVD is the most affected musculoskeletal connective tissue in sand rats with aging and diabetes. The aged and diabetic discs in the sand rat demonstrated changes similar to human changes with regard to lower hydration, FCD, and ability to resist osmotic pressure. Therefore, the sand rat may be a suitable animal model for studying the pathogenesis of disc degeneration.
Spinal mobility and posture in 8‐ to 16‐year‐old children
Authors: Mellin Guy , Poussa Mikko 
Published: February 2005

AbstractSpinal mobility and posture were measured in 294 8‐16‐year‐old boys and girls, divided into five age groups. The upper thoracic sagittal alignment was more vertical among girls, but the postural curves showed no significant age‐related differences for either sex. Among both boys and girls thoracic extension, lateral flexion, and rotation decreased significantly between the ages of 12 and 13, but with the exception of extension they returned to the previous level by age 16. Girls were significantly different from boys at 13 years of age. In the thoracic spine, girls had less kyphosis, and were stiffer in forward and lateral flexion, with more rotation to the right than to the left. In the lumbar spine, lateral flexion increased after the age of 10 in both sexes. Between the ages of 8 and 14 lumbar lateral flexion was significantly greater among girls than among boys, whereas extension and rotation was greater only at the ages of 8 and 10 years. With increasing age, a shift from left to right dominance in lumbar lateral flexion was found in girls only.
Tissue ingrowth into titanium and hydroxyapatite‐coated implants during stable and unstable mechanical conditions
Authors: Søballe Kjeld , Hansen Ebbe S. , B.‐Rasmussen Helle , Jørgensen Peter H. , Bünger Code 
Published: February 2005

AbstractLack of initial mechanical stability of cementless prostheses may be responsible for fibrous tissue fixation of prosthetic components to bone. To study the influence of micromovements on bony ingrowth into titanium alloy (Ti) and hydroxyapatite (HA)‐coated implants, a loaded unstable device producing movements of 500 μm during each gait cycle was developed. Mechanically stable implants served as controls. The implants were inserted into the weight‐bearing regions of all four femoral condyles in each of seven mature dogs. Histological analysis after 4 weeks of implantation showed a fibrous tissue membrane surrounding both Ti and HA‐coated implants subjected to micromovements, whereas variable amounts of bony ingrowth were obtained in mechanically stable implants. The pushout test showed that the shear strength of unstable Ti and HA implants was significantly reduced as compared with the corresponding mechanically stable implants (p < 0.01). However, shear strength values of unstable HA‐coated implants were significantly greater than those of unstable Ti implants (p < 0.01) and comparable to those of stable Ti implants. The greatest shear strength was obtained with stable HA‐coated implants, which was threefold stronger as compared with the stable Ti implants (p < 0.001). Quantitative determination of bony ingrowth agreed with the mechanical test except for the stronger anchorage of unstable HA implants as compared with unstable Ti implants, where no difference in bony ingrowth was found. Unstable HA‐coated implants were surrounded by a fibrous membrane containing islands of fibrocartilage with higher collagen concentration, whereas fibrous connective tissue with lower collagen concentration was predominant around unstable Ti implants. In conclusion, micromovements between bone and implant inhibited bony ingrowth and led to the development of a fibrous membrane. The presence of fibrocartilage and a higher collagen concentration in the fibrous membrane may be responsible for the increased shear strength of unstable HA implants. Mechanically stable implants with HA coating had the strongest anchorage and the greatest amount of bony ingrowth.
Fixation stability of femoral components in a canine hip replacement model
Authors: Vanderby Ray , Manley Paul A. , Kohles Sean S. , McBeath Andrew A. 
Published: February 2005

AbstractA canine hip replacement model was used to compare fixation stability in cemented and cementless femoral components. Parameters of comparison were the load‐induced positional changes of each prosthesis relative to its proximal femoral cortex, hereafter called relative displacements. Identical femoral components, with the proximal third of their stem porous‐coated, were implanted in the right femurs of 10 large, mixed‐breed dogs. Five were tightly fit to allow porous ingrowth, and five were cemented into the medullary canal. Four months after implantation, all femurs were harvested. A prosthesis was implanted in the left (normal) femur of each dog ex vivo with fixation identical to the contralateral limb to simulate acute postoperative fixation. Eddy current transducers measured relative displacements under application of static loads, serially applied in the axial, mediolateral, and craniocaudal directions. Thereafter, the femurs were transversely sectioned and morphologically analyzed to correlate bony apposition at the implant surface with relative displacements. We observed no difference in relative displacements between acute and 4‐month‐cemented groups (e.g., 0.0059 ± 0.0021 vs. 0.0060 ± 0.0048 mm, respectively, for 100‐N axial loading measured at midstem). With cementless implantation, relative displacements of the acute group were significantly larger (p = 0.007) than those of the 4‐month group (e.g., 0.236 ± 0.257 vs. 0.097 ± 0.129 mm, respectively, for 100‐N axial loading measured at midstem). Cementless components implanted for 4 months were not significantly different than cemented components, but a trend suggested that they were still not as stable as cemented components, particularly for craniocaudal loads. Relative displacements of the 4‐month, porous ingrowth group were approximately proportional to the percentage of bony apposition raised to the ‐ 1.44 power (r = 0.94).
Histomorphometric analysis of the epiphyseal growth plate in rats after prenatal alcohol exposure
Authors: Miralles‐Flores Celia , Delgado‐Baeza Emilio 
Published: February 2005

AbstractWe studied the effect of prenatal alcohol exposure on growth in the proximal tibial growth plate in 0‐ and 15‐day‐old rats, using histomorphometric methods. Body weight and tibial length were reduced in all alcohol‐exposed rats. In 15‐day‐old rats, these parameters were lower than in the 15‐day‐old controls, thus showing a persistence of the effects of ethanol. The proximal tibial growth plate showed alterations, principally in 15‐day‐old rats. The most notable of these was a decrease in growth plate height produced by a significant reduction in hypertrophic zone height. Likewise, there were fewer cells in this zone in alcohol‐exposed rats than in controls. This work shows that prenatal ethanol exposure induces growth retardation which may be due to growth plate alterations that might reflect impaired cell function.
Meniscal repair by fibrocartilage? An experimental study in the dog
Authors: Klompmaker Jan , Jansen Henk W. B. , Veth René P. H. , Nielsen Hans K. L. , De Groot Jacqueline H. , Pennings Albert J. , Kuijer Roel 
Published: February 2005

AbstractLongitudinal lesions in the avascular part of the dog's meniscus were repaired by implantation of a porous polyurethane. Ingrowing repair tissue was characterized by biochemical and immunological analysis. Histologically, repair tissue initially was composed of fibrous tissue containing type I collagen. After 3 months, fibrocartilaginous tissue developed inside the implants, whereas control defects only showed fibrous repair tissue. Both type I and II collagen, the major collagen types of normal meniscal fibrocartilage, could be detected in this newly formed fibrocartilage. It is concluded that fibrocartilage resembling normal meniscal tissue is formed and that longitudinal lesions can be healed after mensical repair by implantation of a porous polymer.
Slow release of anticancer drugs from porous calcium hydroxyapatite ceramic
Authors: Uchida A. , Shinto Y. , Araki N. , Ono K. 
Published: February 2005

AbstractWe have developed a new delivery system for sustained release of an anticancer drug (cis‐platinum) by enclosure into blocks of porous calcium hydroxyapatite ceramic. The slow release of this drug from this system was confirmed in in vitro experiments. When this system was implanted into normal back muscle, or the tibia, sustained release of cis‐platinum was observed during a 12‐week period after implantation. The diffusion rate of cis‐platinum into blood and other organs (liver, kidney, brain) was less than 10% of that at the implanted site. This delivery system placed into experimental tumors of mice also showed a uniform release of anticancer drug for more than 3 months. Inhibition of tumor growth was more marked after local implantation of this system than after intraperitoneal administration of cis‐platinum. These results indicate that this new approach to a drug delivery system may well have an important role in cancer chemotherapy. In bone tumors it is attractive because the mechanical strength of calcium hydroxyapatite ceramic permits partial surgical excision and replacement of the bone defect at the same time.
Immunological analysis of proteoglycan structural changes in the early stage of experimental osteoarthritic canine cartilage lesions
Authors: Pelletier Jean‐Pierre , Martel‐Pelletier Johanne , Mehraban Fuad , Malemud Charles J. 
Published: February 2005

AbstractSpecific modifications of the proteoglycan (PG) structure of osteoarthritic (OA) dog cartilage in relation to endogenous metalloprotease activity were examined using murine anti‐proteoglycan monoclonal antibodies (MoAbs). OA lesions were induced over a period of 8 weeks in crossbred dogs (Pond‐Nuki model). The articular cartilage was removed and homogenized in a Tris buffer, pH 7.5, and then divided into four groups: direct PG extraction, no addition, presence of 1 mM p‐aminophenyl mercuric acetate (APMA), and presence of 1 mM APMA and 10 mM o‐phenanthroline, incubated for 42 h at 37°C followed by PG extraction. MoAbs reactive with PG protein and carbohydrate epitopes included 1C6, 3B3, 5D4, D1B2, and m4D6. The results showed marked alterations induced by APMA activation of the endogenous metalloproteases. PG changes were apparent at at least three sites: one was either in the hyaluronic acid‐binding region or between the hyaluronic‐binding region and the G2 globular domain, another was between the keratan‐sulfate‐rich domain and the chondroitin sulfate‐attachment domain, and a third was in the chondroitin sulfate‐attachment domain. Constitutive metalloprotease activity resulted in less marked PG alterations with preservation of functional PG aggregation to hyaluronan.
Local stimulation of proteoglycan synthesis in articular cartilage explants by dynamic compression in vitro
Authors: Parkkinen Jyrki J. , Lammi Mikko J. , Helminen Heikki J. , Tammi Markku 
Published: February 2005

AbstractCultured bovine articular cartilage was subjected to 50 ms, 0.5–1.0 MPa compressions repeated at intervals of 2–60 s for 1.5 h and simultaneously labeled with 35SO4. The compression was delivered with a 4‐mm‐diameter nonporous loading head on an 8‐mm‐diameter cartilage explant. This method created directly compressed (central) and uncompressed (border) areas within the tissue. Analysis of the whole explant under a 0.5 MPa load showed significantly increased 35SO4 incorporation by compression repeated at 2‐ and 4‐s but not at 20‐ and 60‐s intervals. When the incorporation was studied separately in the border and central areas, a statistically significant stimulation was noticed in the central area with a 4‐s cycle, while the border area was stimulated with a 2‐s cycle. Autoradiography of the central area showed that the stimulation with 0.5 MPa and a 4‐s cycle occurred through the whole depth of the cartilage, while raising the pressure to 1 MPa or the frequency to 2 s reduced the stimulation, particularly in the superficial cartilage. In the border area the stimulation with 0.5 MPa and a 2‐s cycle was noted in the superficial zone only. The stimulation of proteoglycan synthesis is thus limited to certain loading frequencies and pressures and occurs in specific areas under and around the loaded site. Its rapid appearance suggests enhanced glycosylation or sulfation of core proteins or enhanced speed of posttranslational processing.
Chemotherapy and surgery in a murine osteosarcoma
Authors: Bell R. S. , Jacobs J. 
Published: February 2005

AbstractSurgical and chemotherapeutic effects on pulmonary metastatic disease were evaluated in the MGH‐OGS murine osteosarcoma. The tumor responded to three sequential injections of doxorubicin with prolonged growth delay but cisplatin administration (although given in doses sufficient to cause weight loss and significant mortality) was not effective in controlling local disease progression. Using a protocol with three injections of doxorubicin (0.006 mg/g of body weight), it was observed that disease‐free survival was enhanced when one of the three doses of doxorubicin was given at the time of surgery (perioperatively). By marginally resecting the primary tumor and permitting its regrowth, a model was developed with recurrent primary and metastic disease present simultaneously. It was observed in this model that amputation or resection of the recurrent primary lesion resulted in pulmonary metastatic growth acceleration. Using this recurrent primary tumor model, doxorubicin's effect on pulmonary metastatic lesions was enhanced when the drug was given at the time of amputation.
Bone formation near direct current electrodes with and without motion
Authors: Spadaro Joseph A. , Albanese Stephen A. , Chase Sharon E. 
Published: February 2005

AbstractThe osteogenesis induced in the medullary canal of rabbits by the implantation of moving and stationary wire electrodes was studied with and without the simultaneous application of 20‐μA constant direct cathodic current. After 3 weeks, the formation of new trabecular bone in the canal was studied and measured microscopically. Electrically stimulated osteogenesis was not observed at stationary electrodes. As in previous studies with this model, a movable electrode alone stimulated new bone formation whose area was 7–10% of the canal area. The amount of this bone was not statistically increased by the addition of cathode current. Movable, electrically active cathodes were associated, however, with fluid‐filled spaces incorporated within the new trabecular bone. When mechanical stimuli were controlled, we were not able to demonstrate that the direct current stainless steel cathode acts either as an inducer or a substantial enhancer of medullary osteogenesis.