bluuebunny/crossref_metadata_2025_split huggingface dataset:
Immunology of peripheral nerves and response to trauma
Authors: Trumble Thomas , Stanislaw James 
Published: February 2005

AbstractResearch in limb reconstruction using peripheral nerve tissue has been hampered by tissue rejection. In order to provide more information on the immunology of peripheral nerves, 35 specimens (26 from seven cadavers and nine from surgical biopsies) were analyzed for the presence of human leukocyte antigens (HLA), which are a key component of major histocompatibility complex class II (MHC Class II) antigens. MHC Class II antigens were noted in all human nerve specimens, and the percentage of areas of positive staining by immunohistochemistry was significantly higher (3.82% ± 1.01%) than that of negative controls (.05% ± 0.02%) (p < 0.01). The negative controls consisted of serial sections that were stained in the same manner except that the primary antibody was deleted. There was no significant difference in the presence of MHC Class II antigens between sensory and mixed motor nerves or among the different HLA groups (HLA‐DR, HLA‐DP, HLA‐DQ). A mouse model was used to evaluate the effect of trauma on the presence of MHC Class II antigens. Three weeks after transsection of the sciatic nerve there was a statistically significant increase (p < 0.05) in the presence of MHC Class II antigens in the distal portion of the nerve (4.49% ± 0.78%) as compared with samples from animals that had had exposure of the nerve without transsection (1.44% ± 0.21%) or in nerves from animals that had had no surgery (1.02% ± 0.21%). The presence of MHC Class II antigens could require more complex cross‐matching for tissue transplantation. Nerve grafts that have undergone Wallerian degeneration may actually be more prone to rejection than are other peripheral nerve tissue transplants.
Absorption of lidocaine following topical application in microvascular procedures on rabbits
Authors: Hou Sheng‐Mou , Liu Tang‐Kue , Yu Hsiu‐Ying 
Published: February 2005

AbstractFifty rabbits were used to investigate the absorption of lidocaine following its topical application to blood vessels. The lidocaine level in the blood was determined by gas chromatography and the enzyme immunoassay. Animals were divided into five groups according to anatomic site (femoral vs iliac) and according to whether vessels were intact or anastomosed. In the last group (E), a water‐tight sleeve was placed on the anastomosed femoral artery so that the lidocaine contacted only a small segment of the artery. In each group, 0.4 and 1 ml of 10% lidocaine were used. Our results revealed that absorption of lidocaine from topical usage was rapid. The absorption peak occurred within 5–15 min. The serum concentration of lidocaine was significantly higher in groups with intact vessels than in those with anastomosed ones. The peak level of lidocaine in the serum occurred sooner in the iliac area than in the femoral area. Absorption in group E was very low due to only a small segment of the artery being immersed with lidocaine. The main absorption site of lidocaine was not through the vessel but through the perivascular area. Toxicity may develop clinically if a high concentration of lidocaine is applied on a vessel during microsurgery.
Trunk positioning accuracy in the frontal and sagittal planes
Authors: McGlashen K. , Ashton‐Miller J. A. , Green M. , Schultz A. B. 
Published: February 2005

AbstractThe accuracy with which the head and spine could be positioned in the frontal and sagittal planes relative to the pelvis was measured and compared in ten healthy adult males. Subjects were tested with eyes closed, while standing with their pelvis externally restrained. The positions of markers, attached to the back of the head and over each of the T1, T6, T11, and L3 spinous processes, were measured to the nearest mm using strain‐gaged flexible beam transducers. Subjects were tested for their accuracy in sensing return of the trunk to an initial neutral position under different test conditions. Results showed that positioning was 16–45% more accurate in the frontal than in the sagittal plane, although the difference did not reach statistical significance. T1 could be centered to within 7 and 10 mm in the frontal and sagittal planes, respectively. No significant differences were found between active and passive positioning accuracies. Presence of an external trunk moment did not significantly affect trunk positioning accuracy, although it systematically caused overshoot of the neutral position. Lastly, lateral trunk shifts exceeding 12 mm may be classified as abnormal in young adults.
Comparison of cortical bone and serum concentrations of clindamycin achievable by direct local infusion and intravenous administration
Authors: Budsberg Steven C. , Gallo James M. , Starliper Clifford E. , Shotts Emmett B. , Brown John 
Published: February 2005

AbstractTibial cortical bone and serum concentrations of clindamycin were compared using two drug delivery methods in dogs. An implantable drug pump, used to continuously infuse clindamycin directly into the cortical bone, was compared with clindamycin administered i.v. Dosage for the direct continuous infusion was 4 mg/kg/day, and 44 mg/kg/day for the i.v. bolus regimen. Serum concentrations of clindamycin were significantly higher during i.v. bolus administration when compared with those achieved during pump infusion (p < 0.05). However, tibial cortical bone concentrations were significantly higher during pump infusion than were those achieved by i.v. bolus. When examining serum and bone clindamycin concentrations over 21 days of direct local infusion, there was no significant difference in concentrations between sampling days within each tissue (p > 0.05). Furthermore, there were significantly greater concentrations of clindamycin in the cortical bone than in the serum at each sampling period (p < 0.05). Results indicate that delivery of clindamycin to canine bone by implantable drug pump achieve significantly higher bone concentrations than i.v. bolus administration of the drug at higher dosages. Direct infusion also can sustain high concentrations in cortical bone without increasing systemic concentrations of clindamycin.
Studies on the autocrine activation of a synovial cell line
Authors: Baratz M. E. , Georgescu H. I. , Evans C. H. 
Published: February 2005

AbstractThe lapine synovial cell line HIG‐82 secretes factors that activate cultures of articular chondrocytes. We showed that these “chrondrocyte‐activating factors” (CAF) also activate quiescent cultures of HIG‐82 cells in an autocrine fashion. After exposure to partially purified preparations of CAF, HIG‐82 cells increased their synthesis of prostaglandin E2 (PGE2) and the neutral proteinases collagenase, gelatinase, and stromelysin. CAF also induced their own synthesis. Both PGE2 synthesis and endogenous production of CAF started to increase between 1 and 3 h after treatment of cells with exogenous CAF, but the neutral proteolytic activity of the conditioned medium took ∼ 12 h to increase. Induction of neutral proteinases by CAF was inversely related to the degree of cell confluency. Whereas their induction by phorbol myristate acetate (PMA) was independent of this parameter. Both CAF and PMA provoked morphologic changes in subconfluent cultures of HIG‐82 cells. Although the intracellular concentration of free Ca2+ increased rapidly in response to CAF, the results of experiments with calcium channel blockers and ionophores failed to support a role for Ca2+ fluxes in induction of neutral proteinases. In similar types of experiments, no evidence could be found to implicate fluxes in cyclic AMP or cyclic GMP in the induction of collagenase, gelatinase, or stromelysin. Because PMA is such a strong inducer of these enzymes, protein kinase C may be involved in signal transduction, but further work is needed to determine whether this is so.
Proteoglycan alterations during developing experimental osteoarthritis in a novel hip joint model
Authors: Inerot Sven , Heinegård Dick , Olsson Sten‐Erik , Telhag Hans , Audell Lars 
Published: February 2005

AbstractDegenerative hip joint disease was induced in dogs by extraarticular surgery that created a condition that mimics hip dysplasia. Decreased acetabular coverage of the femoral head gave altered mechanical load, with ensuing cartilage degeneration. For comparison, degenerative knee joint disease was induced in other dogs by transection of the anterior cruciate ligament of the knee. The femoral head articular cartilage showed macroscopic signs of degeneration within a month. No macroscopical changes of synovitis were present. Chemical analysis of cartilage samples showed loss of proteoglycans. Guanidine hydrochloride extracts of the cartilage contained proteoglycan fragments that could be separated by equilibrium density gradient centrifugation in cesium chloride. The data indicate that proteoglycans are fragmented by proteolytic cleavage and lost from the cartilage. The proteoglycans remaining in the tissue are smaller and have lost the ability to aggregate with hyaluronic acid. Similarly, in experimental knee joint osteoarthritis, the proteoglycan content of the cartilage decreased. The structural changes of those proteoglycans remaining were of a different nature, with no changes in proteoglycan size or aggregation properties, possibly indicating that both degradation and repair took place in the knee articular cartilage and/or that fragments were rapidly lost from the tissue. This may follow from different surgical procedures, only the one used for the hip joint being extra‐articular, or from the different anatomy and physiology of the hip joint and the knee joint.
Elimination of exogenously injected sodium‐hyaluronate from rabbit flexor tendon sheaths
Authors: Hagberg Lars , Tengblad Anders , Gerdin Bengt 
Published: February 2005

AbstractTo obtain information about the elimination of Na hyaluronate (NaHe) deposited in flexor tendon sheaths in rabbits, two flexor tendon sheaths from each hind limb were operatively exposed in 15 animals and each filled with one of four different NaHe preparations, namely: 10 mg/ml, MW 2.6 × 106; 10 mg/ml, MW 6.3 × 106; 19 mg/ml, MW 3.0 × 106; and 19 mg/ml, MW 6.5 × 106. One, 3, and 7 days after surgery, the NaHe concentration was measured in frozen specimens from the tendon sheaths. One day after surgery, NaHe concentration in the tendon sheath fluid was close to 10 mg/ml in all groups. Three and 7 days after surgery it was higher in tendon sheaths in which NaHe preparations with a high (19 mg/ml) rather than with a low concentration (10 mg/ml) had been deposited. At 3 days, NaHe concentration was also higher in sheaths that had received a preparation with a high MW (6.5 × 106) than those with a lower MW (2.6 or 3.0 × 106). The findings suggest that within the first 24 h, a dilution of concentrated NaHe preparations takes place, probably as a result of their hyperoncotic properties. After 24 h, there was a slower decline in NaHe concentration when more concentrated solutions (19 mg/ml) and solutions with high MWs (6.5 × 106) were administered. Development of pharmaceutical NaHe preparations with slow elimination from tendon sheaths should reasonably be focused on a solution with a high MW and high concentration.
Bone graft translation of four upper cervical spine fixation techniques in a cadaveric model
Authors: Crisco Joseph J. , Panjabi Manohar M. , Oda Takenori , Grob Dieter , Dvorak Jiri 
Published: February 2005

AbstractThe goal of spinal fixation is to promote bony fusion by restricting motion at the site of the bone graft. Therefore, in order to evaluate the efficiency of various cervical fixation techniques, we determined the translations at the posterior arch of C1 for four C1—C2 posterior techniques: Gallie, Brooks, Magerl, and Halifax. Our model was the cadaveric specimen, with extensive soft tissue injury: transection of the alar, transverse, and capsular ligaments. Under three‐dimensional physiological loading, we recorded the motion of C1 relative to C2, and calculated the translations at the surface of the graft in three dimensions, 10 specimens being tested intact, injured, and instrumented with each of the techniques. We assumed that translational laxity or neutral zone was the critical motion parameter and evaluated it, quantified herein as the neutral zone, at seven points at the graft site. The three‐dimensional neutral zone translations were analyzed by their axial and shear components. We found that there was no significant difference with the fixation techniques in the average axial translation (Brooks: 1.1 mm; Magerl: 1.3 mm; Gallie: 1.5 mm; and Halifax: 0.5 mm). In shear, the Magerl averaged 1 mm, which was significantly less than the Gallie (2.1 mm). The Brooks (1.6 mm) and Halifax (1 mm) were not different from each other, Magerl, or Gallie. We propose that evaluation by translational laxity (neutral zone) at the graft site is a noteworthy concept in biomechanical analysis.
Proliferation and macromolecular synthesis by rat calvarial bone cells grown in various oxygen tensions
Authors: Brighton Carl T. , Schaffer Jonathan L. , Shapiro David B. , Tang Johnson J. S. , Clark Charles C. 
Published: February 2005

AbstractPerinatal rat calvarial bone cells were isolated by sequential collagenase digestion and grown in oxygen tensions ranging from 1 to 60% O2. Cell proliferation as determined by automated cell counting and DNA content was greatest in the lower oxygen tensions (≥ 9% O2), whereas alkaline phosphatase activity and [35S]sulfate and [14C]proline incorporation were greatest in the higher oxygen tensions (≥ 13% O2). It is concluded that lower oxygen concentrations favor bone cell proliferation, whereas higher oxygen concentrations favor macromolecular synthesis. These findings, when related to the known pO2 of the fracture callus, suggest the following sequence of events: first, at the time of fracture an ingrowth of osteoprogenitor cells, capillary buds, and primitive mesenchymal cells occurs in the fracture site, a region of low pO2; second, a great increase in cellular proliferation accompanied by an initiation of macromolecular synthesis follows; finally, as the pO2 levels begin to increase, cellular proliferation decelerates, accompanied by an increase in macromolecular synthesis.
Postfracture irradiation effects on the biomechanical and histologic parameters of fracture healing
Authors: Brown Robert K. , Pelker Richard R. , Friedlaender Gary E. , Peschel Richard E. , Panjabi Manohar M. 
Published: February 2005

AbstractThe effects of single‐dose local irradiation on the biomechanical properties of closed femoral fractures were studied in 75 mature Sprague‐Dawley rats. Ten days after fracture, the rats were irradiated with 900 rads at 250 kV to the entire fractured femur. At 2, 3, 4, 8, and 16 weeks after fracture, both fractured and contralateral intact femurs were recovered and evaluated biomechanically by testing to failure in torsion. Results were compared with those from a similar study involving fractures irradiated 3 days after fracture as well as nonirradiated control fractures. Fracture healing progressed faster when irradiation was delayed 10 days than when delayed 3 days, and control fractures healed more rapidly than after either delay. In the 10‐day delay group, fractures showed greater strength than did those in the 3‐day delay group at 8 weeks, but the strength of irradiated fractures in both groups was similarly depressed at 16 weeks, with a maximum torque well below that of control fractures. These results suggest that delaying radiation exposure of a fracture may mitigate short‐term deleterious effects on fracture repair, but that long‐term results may be similar to those associated with expeditious irradiation.
Electromagnetic stimulation of bone repair: A histomorphometric study
Authors: Canè Valerio , Botti Paolo , Farneti Daniele , Soana Silvana 
Published: February 2005

AbstractThe effect of pulsing electromagnetic fields (PEMFs) on bone repair was studied in principal metacarpal bones of eight adult male horses: Six horses were treated with PEMFs, and two horses were untreated. In treated horses, Helmholtz coils were applied during a 60‐day period to the left metacarpal bones, bored with eight holes of equal diameter and depth, from the middiaphysis toward the distal metaphysis. Eight equal holes bored in the right metacarpal, surrounded by unactivated Helmholtz coils, were taken as controls. The two untreated horses were taken as additional control. The results of computer‐assisted histomorphometric analysis indicate that (a) in diaphyseal levels, the amount of bone formed during 60 days is significantly greater (p < 0.01) in PEMF‐treated holes than in contralateral ones and those in control horses; (b) in metaphyseal levels, PEMF‐treated holes are sometimes more closed, sometimes less, as compared with contralateral holes and those in control horses; in any case the statistical analysis indicates that the symmetry in the rate of hole repair, found between the two antimeres of control horses, is not appreciable at metaphyseal levels also; (c) there was no statistically significant difference between untreated holes in PEMF‐treated horses and holes in control horses, neither at diaphyseal nor at metaphyseal levels. These preliminary findings indicate that PEMFs at low frequency influence the process of bone repair on both diaphysis and metaphysis, and seem to improve the process of bone repair in skeletal regions normally having a lower osteogenetic activity, i.e., in diaphyses as against metaphyses.
Effects of free and bound insulin‐like growth factors on proteoglycan metabolism in articular cartilage explants
Authors: Tesch Gregory H. , Handley Christopher J. , Cornell Hugh J. , Herington Adrian C. 
Published: February 2005

AbstractThis article describes the effects of bound forms of insulin‐like growth factors (IGFs) on proteoglycan metabolism by bovine articular cartilage in explant culture. When these growth factors were added to articular cartilage explants complexed with their native serum binding proteins (BPs), both IGF‐I‐BP complex and IGF‐II‐BP complex stimulated proteoglycan synthesis to different degrees over a 3‐day period. When added to the medium of cultures of articular cartilage over 5 days, IGF‐II‐BP complex induced high rates of synthesis and low rates of catabolism of proteoglycans, giving rise to tissue levels of proteoglycan similar to those observed in fresh tissue. When articular cartilage was maintained in culture with the same concentration of IGF‐I‐BP complex, tissue levels of proteoglycans fell over the culture period because of lower rates of proteoglycan synthesis. Analysis of the proteoglycans synthesized by articular cartilage in the presence of free or bound IGF‐I or IGF‐II showed that these growth factors stimulated the rate of synthesis of the large proteoglycan species present in cartilage but did not affect the synthesis of the small proteoglycans.
Morphological basis for back pain: The demonstration of nerve fibers and neuropeptides in the lumbar facet joint capsule but not in ligamentum flavum
Authors: Ashton I. K. , Ashton B. A. , Gibson S. J. , Polak J. M. , Jaffray D. C. , Eisenstein S. M. 
Published: February 2005

AbstractThe innervation of lumbar facet capsule and ligamentum flavum was investigated using antisera to a general neuronal marker protein gene product (PGP) 9.5 and to peptide markers of sensory nerves (calcitonin generelated peptide [CGRP] and substance P) and autonomic nerves (vasoactive intestinal polypeptide [VIP] and C‐flanking peptide of neuropeptide Y [CPON]). In the facet capsule (n = 14), PGP 9.5 and CGRP‐immunoreactive nerves occurred in 12 and five specimens, respectively, both around blood vessels and as free fibers in the stroma. Free fibers immunoreactive for substance P or VIP were noted in three and five specimens, whereas in nine specimens there were CPON‐immunoreactive nerves located perivascularly. There was no immunoreactivity in the ligamentum flavum. This study provides further evidence that the facet capsule but not the ligamentum flavum has substantial innervation by sensory and autonomic nerve fibers and has a structural basis for pain perception.
Ultrastructural morphometry of anterior cruciate and medial collateral ligaments: An experimental study in rabbits
Authors: Hart R. A. , Woo S. L‐Y. , Newton P. O. 
Published: February 2005

AbstractThis study presents morphometric analyses of collagen subfascicle area fraction and collagen fibril diameter distributions for the anterior cruciate (ACL) and medial collateral (MCL) knee ligaments from transmission electron micrographs of ligament cross sections of five mature, female New Zealand White rabbits. Statistically significant differences in subfascicular area fractions were found between the ACL and MCL (0.89 ± 0.02, 0.97 ± 0.01, respectively; p < 0.001). Mean fibril diameters for the ACL and MCL were also significantly different (0.059 ± 0.005, 0.085 ± 0.011 μm, respectively; p < 0.025). Fibril eccentricity (a measure of parallel alignment of collagen fibrils within the ligaments, defined as the ratio of minor to major axes of elliptical fibril outlines) was 0.89 ± 0.03 and 0.85 ± 0.08, respectively, for the ACL and MCL; these data were not significantly different (p > 0.1). The relative amount of variation in the pooled fibril diameter data due to variation between animals, ligaments, locations within ligaments, and among fibrils at individual locations are reported. The variation of fibril diameter distributions between the ACL and MCL was substantially greater than the variation between different locations within each ligament cross section as well as between different animals. The structural differences reported may help explain known differences in the biomechanical properties of the ACL and MCL.
Combined effect of acute denervation and ischemia on the microcirculation of skeletal muscle
Authors: Chen Long‐En , Seaber Anthony V. , Urbaniak James R. 
Published: February 2005

AbstractUsing direct in vivo videomicroscopy and a fluorescein dye technique, reperfusion injury after 3 h of ischemia was studied in the acutely denervated cremaster muscle of the rat. Compared with normally innervated controls, ischemia‐induced reperfusion injury was more severe in the denervated group and included a delay of blood flow recovery, vortex formation, edema, hemorrhage, and vessel spasm. Vessel size was reduced at the arteriole and small artery level, and there was a decrease of reactive hyperemia. The injury mechanism may be related to a loss of active vasomotion and vascular response to vasoactive substances after denervation. The results suggest that shortening the ischemia time of denervated tissues may reduce ischemia‐induced reperfusion injury. Similarly, given the same ischemia time, improved tissue reperfusion may be expected if the nerve supply is maintained.