bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tissue fluid pressures: From basic research tools to clinical applications
Authors: Hargens Alan R. , Akeson Wayne H. , Mubarak Scott J. , Owen Charles A. , Gershuni David H. , Garfin Steven R. , Lieber Richard L. , Danzig Larry A. , Botte Michael J. , Gelberman Richard H. 
Published: February 2005

AbstractThe two basic research tools developed to measure tissue fluid pressure (wick catheter) and osmotic pressure (colloid osmometer) have undergone extensive validation and refinement over the past 20 years. Using these techniques, basic science investigations were undertaken of edema in Amazon reptiles, pressure‐volume relations in animals and plants, adaptive physiology of Antarctic penguins and fishes, edema in spawning salmon, tissue fluid balance in humans under normal conditions and during simulated weightlessness, and orthostatic adaptation in a mammal with high and variable blood pressures—the giraffe. Following and sometimes paralleling this basic research have been several clinical applications related to use of our colloid osmometer and wick technique. Applications of the osmometer have included insights into (a) reduced osmotic pressure of sickle‐cell hemoglobin with deoxygenation and (b) reduced swelling pressure of human nucleus pulposus with hydration or certain enzymes. Clinical uses of the wick technique have included (a) improvement of diagnosis and treatment of acute and chronic compartment syndromes, (b) elucidation of tissue pressure thresholds for neuromuscular dysfunction, and (c) development of a better tourniquet design for orthopaedics. This article demonstrates that basic research tools open up areas of basic, applied, and clinical research.
The interrelation of fiber bundles in the anterior cruciate ligament
Authors: Clark John M. , Sidles John A. 
Published: February 2005

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 supply.
Effect of donor age on the growth in vitro of cells obtained from human trabecular bone
Authors: Evans Carol E. , Galasko Charles S. B. , Ward Carol 
Published: February 2005

AbstractThe proliferation of human bone‐derived cells (BDCs) was assessed in vitro, using [3H]thymidine incorporation and cell counting in a haemacytometer. The cells were cultured from human trabecular bone from 87 patients aged 2–88 years. The in vitro growth of these cells was unaffected by the chronological age of the donor. However, the cell number at confluence was shown to decrease with increasing donor age, this trend being most marked after 60 years of age. Other assays of the metabolic efficiency of the BDCs, namely, total protein, osteocalcin, and alkaline phosphatase synthesis, did not show any change with increasing donor age. These results suggest that while the ability of individual cells to divide and to perform specific synthetic activities is unimpaired with increasing age, other subtler changes may occur, leading to a decrease in the bone's osteogenic capacity.
Dynamic electromyography. II. Normal patterns during gait
Authors: Wootten M. E. , Kadaba M. P. , Cochran G. V. B. 
Published: February 2005

AbstractHuman gait is a complex phenomenon. Many descriptors are needed to completely describe gait in terms of the biomechanics involved. The descriptors, when expressed as a function of the gait cycle, are complex waveforms. For each of these variables, a single “normal” pattern with bands of deviation has generally been accepted as a reference in clinical/research use to explain the abnormalities in a patient's walking pattern. In fact, one observes many “normal” patterns, and a body of research has been devoted to explaining the differences between these patterns in terms of walking speed, age, cadence, sex, etc. It would be simpler in one sense to start with the fact that different people walk with different patterns, not one pattern with bands of deviation. Numerical representation of the waveforms simplifies the analysis and interpretation of waveform data and facilitates comparison between subjects or groups of subjects. When combined with pattern recognition techniques, it also is useful for identifying subpatterns within a group. In this article, the numerical representation of electromyographic data by Karhunen‐Loeve expansion are combined with cluster analysis to obtain patterns of dynamic phasic activity of 10 muscles of the lower extremity. From the 35 normal subjects walking at self‐selected speed, two to four patterns are developed for each of the muscles and the physiological significance of the patterns are discussed.
Pulsing direct current‐induced repair of articular cartilage in rabbit osteochondral defects
Authors: Lippiello Louis , Chakkalakal Dennis , Connolly John F. 
Published: February 2005

AbstractOsteochondral defects in the distal femoral condyles of rabbits exposed to a pulsing direct current exhibits an enhanced quality of repair. The signal, with a peak value of 2 μA repeating at 100 Hz, imposed an electric field in the tissue of 20–60 mV/cm2. Maximum efficacy was seen with a shorter period of exposure (40 vs. 160h) initiated 48 h after surgery for 4 h/day. Repair tissue originated primarily from metaplasia of subchondral elements although hyperplasia of pre‐existing chondrocytes at the margins of the defect could be detected. Defects in treated joints contained Safranin O staining material that was histologically similar to a disorganized hyaline cartilage. Central areas of the defects in control animals contained Safranin O‐negative material that generally extruded over the surface as a pannus. The edges of nontreated defects also had characteristics of cartilaginous healing, stressing the importance of using serial sectioning techniques in this model of cartilage repair.
Effect of low frequency pulsing electromagnetic fields on skin ulcers of venous origin in humans: A double‐blind study
Authors: Ieran M. , Zaffuto S. , Bagnacani M. , Annovi M. , Moratti A. , Cadossi R. 
Published: February 2005

AbstractThe effect of an electromagnetic field on the healing of skin ulcers of venous origin in humans has been investigated in a double‐blind study. Forty‐four patients have been admitted to the study; one‐half were exposed to active stimulators (experimental group) and the remaining to dummy stimulators (control group). The stimulation was scheduled to last a maximum of 90 days. The success rate was significantly higher in the experimental group both at day 90 (p < 0.02) and in the follow‐up period (p < 0.005). The data suggest that the effect of the electromagnetic field lasts even when the stimulation is over. No ulcers worsened in the experimental group, while four worsened in the control group. Twenty‐five percent of the patients in the experimental group and 50% in the control group experienced recurrence of the ulcer. It is concluded that stimulation with an electromagnetic field is a useful adjunctive therapy in the management of these patients.
Vascular changes in the chest wall after unilateral resection of the intercostal nerves in the growing rabbit
Authors: Agadir M. , Sevastik B. , Reinholt F. P. , Perbeck L. , Sevastik J. 
Published: February 2005

AbstractIn young, growing white New Zealand rabbits the third, fourth, and fifth intercostal nerves were resected anteriorly on the right side. Six months later the animals developed structural left convex scoliosis, with a Cobb angle ranging from 15 to 31°. The vascular structure changes of the anterior chest wall were evaluated by measuring surface temperature and fluorescein intensity of the pectoral muscles, and the capillary density of the pectoral and intercostal muscle and periosteal parts of the ribs after angiography. In five normal control rabbits there was neither scoliotic deformity nor significant differences in the examined vascular variables between the right and left sides. In the animals undergoing resection, the temperature of the pectoral muscle on the side of the denervation—the right side—was significantly increased (p < 0.05), but the difference was not correlated to the degree of scoliosis. The fluorescence index was significantly greater (p < 0.05) on the right than on the left side, this difference being fairly strongly correlated to the degree of scoliosis. The capillary densities of the costal periosteum and the intercostal and the pectoral muscle were significantly greater (p < 0.05) on the right than on the left side, and the difference was positively correlated to the degree of scoliosis. The volume density of the periosteum of the ribs was likewise significantly greater on the right. These results demonstrate that unilateral resection of the intercostal nerves significantly increase the vascularity of the structures on the denervated side of the thorax. This development may account for the greater longitudinal growth of the ribs on this side and for the development of the scoliosis observed in earlier studies.
The potential of adult human perichondrium to form hyalin cartilage in vitro
Authors: Bulstra Sjoerd K. , Homminga George N. , Buurman Wim A. , Terwindt‐Rouwenhorst E. , van der Linden Anton J. 
Published: February 2005

AbstractThe usefulness of adult human perichondrium for the restoration of articular cartilage defects depends on the potential to form hyalin cartilage. In order to evaluate the capacity of adult human perichondrium to form hyalin cartilage in vitro, perichondrium of the rib of eight adult human beings was cultured in vitro. After removal of residual cartilage, perichondrial explants were cultured for 7 or 10 days. The explants were histologically examined using specific stains to prove the presence of glycosaminoglycans (GAGs) normal for hyalin cartilage. Clear differentiation of perichondrial cells towards chondrocytes was noted. The chondrocytes synthesized new matrix substances normally present in hyalin cartilage. This investigation supports the usefulness of adult human rib perichondrium for the restoration of cartilage defects. Due to the enormous potential of the rib perichondrium to from hyalin cartilage in vitro, even defects in joints with a rather thick cartilage layer might be restored using this biological material.
Cathepsin B and cysteine protease inhibitors in human osteoarthritis
Authors: Martel‐Pelletier J. , Cloutier J. M. , Pelletier J. P. 
Published: February 2005

AbstractThe aim of this study was to determine the involvement of cathepsin B and its inhibitors in the proteolytic degradation of human osteoarthritic (OA) tissue. The characteristics of the cathepsin B found in both normal and OA cartilage and synovium were similar to those of the lysosomal cathepsin B. Two inhibitors of cysteine proteases were found with a molecular weight of 67,000 and 16,000 Da. The cartilage cathepsin B level of OA specimens (54.8 ± 7.3 units/μg of DNA) was greater than the controls (39.8 ± 3.2 units/μg of DNA). Mild‐moderate graded samples (78.1 ± 12.0 units/μg of DNA) had significantly higher levels of enzyme activity than the severely graded ones (31.4 ± 3.9 units/μg of DNA, p < 0.001) and controls (p < 0.01). Compared to controls (2.3 ± 0.4 units/mg of tissue w.w.), cysteine protease inhibitory activity in OA cartilage was decreased in specimens with severe lesions (1.5 ± 0.2 units/mg of tissue). This was particularly noted in patients who had not received steroid injections (1.2 ± 0.3 units/mg of tissue, p < 0.05). In OA synovia, the cathepsin B level was greater (40.7 ± 7.4 units/mg of tissue w.w., p < 0.02) than in the controls (13.6 ± 3.7 units/mg of tissue). The cysteine protease inhibitory activity was similar in OA synovium (1.7 ± 0.2 units/mg of tissue w.w.) and in controls (1.5 ± 0.3 units/mg of tissue). This data demonstrated an imbalance between the levels of cathepsin B and cysteine protease inhibitors in OA tissue. A decrease of specific inhibitors could be an important contributing factor, particularly in more severe lesions.
The development morphology of a “periosteal” ligament insertion: Growth and maturation of the tibial insertion of the rabbit medial collateral ligament
Authors: Matyas J. R. , Bodie D. , Andersen M. , Frank C. B. 
Published: February 2005

AbstractThe structural properties of ligament insertions change dramatically during growth and maturation, but little is known about their developmental anatomy. This study describes and quantifies changes in the gross and microscopic anatomy of the tibial insertion of the rabbit medial collateral ligament (MCL) during development and at skeletal maturity. Eighty animals were used for growth and descriptive studies. From this group, 27 animals, ranging in age from 1 to 24 months, were injected with fluorescent bone markers and their tibial insertions were processed undecalcified for histology. Sections were examined by polarized light and fluorescence microscopy to identify matrix and cells and to quantify mineral formation. Results showed that animals achieved histological skeletal maturity between 9 and 12 months of age. Body weights were a poor index of skeletal maturity. The tibial insertion was composed of five tissue layers, which changed proportions during growth and maturation. In immature animals, MCL fibers entered the periosteum; in older animals, MCL fibers were cemented to the tibia by advancing mineral. The tibial attachment of the MCL was thus transferred from the periosteum to the cortex during growth, suggesting that the term “periosteal insertion” is imprecise in adults. The hypothesis is put forward that these structural changes account for the reported increase in tensile failure of this insertion near skeletal maturity.
The early effect of high molecular weight hyaluronan (hyaluronic acid) on anterior cruciate ligament healing: An experimental study in rabbits
Authors: Wiig Monica E. , Amiel David , Vandeberg Jerry , Kitabayashi Linda , Harwood Fred L. , Arfors Karl E. 
Published: February 2005

AbstractThe purpose of this study was to assess, morphologically and biochemically, the effect of hyaluronan (HA) on the early repair process of the anterior cruciate ligament (ACL). Following partial bilateral laceration in the midsubstance of the cruciate ligament, a single dose of HA (MW of 3.6 × 106) was injected in one knee and saline in the contralateral knee. Postsurgery, the rabbits were allowed normal (nonimmobilized) cage activity, and were killed after 4 (n = 11) and 12 (n = 10) weeks. The ligaments were evaluated by gross morphology and graded according to the degree of repair. We used grades 1, 2, and 3 for uncovered, partially covered, and totally covered lacerations, respectively. Five of the HA‐treated ligaments at each time studied were completely covered, compared to 0 at 4 weeks, and 1 at 12 weeks in the saline group. Paired evaluations of the lacerated ACLs showed that the HA‐treated ligaments received a healing grade higher than the ligaments exposed to saline in 14 of the 21 animals. In the remaining animals, there was no difference between the sides. The repaired tissue of the ACLs was also examined by light and electron microscopy. When compared qualitatively with saline controls, HA‐treated ligaments exhibited a more pronounced repair, with an increased angiogenesis and less inflammatory response. Biochemical analysis demonstrated a mean higher value of type III collagen in the HA‐treated injured ACL than in saline‐treated injured ACL (13.4 ± 1.1% and 11.0 ± 0.8%, respectively). This increased synthesis of type III collagen in the HA‐treated injured ACL was statistically higher (p < 0.05) when compared to the saline‐treated injured ACL.
Dynamic stress response of the implant/cement interface: An axisymmetric analysis of a knee tibial component
Authors: Ahemd A. M. , Tissakht M. , Shrivastava S. C. , Chan K. 
Published: February 2005

AbstractTo determine the adverse effects on the implant/cement interface stresses caused by a dynamic load on the implant, an axisymmetric dynamic finite element analysis was performed for an idealized knee tibial component assuming perfect bonding at the interface. The component, consisting of a metal plate with a central stem, was subjected to a compressive load that varied with time as a terminated ramp function. At first, the reliability of the interface stress predictions was assessed by computing the effects of a number of method‐related parameters, viz., the finite element mesh density, the assumed bone properties. Analysis was then performed considering the stem length, cement mantle thickness, and the type of implant metal as design variables. The analysis predicts high‐frequency (600 Hz) stress oscillations of significant amplitude at those locations of the interface that are also subjected to high static stresses: near the stem‐plate junction and the stem tip for normal stress, and at the stem tip for shear stress. However, the predicted stress amplitude has been found to be particularly sensitive to the assumed rise time of the input load function. With a rise time of 2.0 ms, an input condition considered to be severe enough to represent the most vigorous dynamic activity, the maximum stress augmentation, because of stress oscillations, is predicted to be less than 25%. In general, the design variables have been found to affect the static stresses much more than the dynamic ones. It has been concluded that for the cases studied, dynamic effects are relatively small and a static analysis is sufficient to characterize the interface stress condition.
A new “transducer‐tipped” fiber optic catheter for measuring intramuscular pressures
Authors: Crenshaw Albert G. , Styf Jorma R. , Mubarak Scott J. , Hargens Alan R. 
Published: February 2005

AbstractLaboratory and clinical tests were used to determine the efficacy of a new fiber optic “transducer‐tipped” catheter for measuring intramuscular pressures. When pressures ranging from 0 to 250 mm Hg were applied by a mercury manometer, the fiber optic system accurtely recorded the pressures. In addition, the fiber optic system showed long‐term stability by accurately recording the manometer pressure over a 3 day period. The Slit system showed a higher magnitude of hydrostatic pressure artifacts with catheter tip movement as compared to the fiber optic system. The two catheters showed no difference when measuring pressures in pig muscle at rest or when being compressed throughout a range of 0 to 250 mm Hg. In human volunteers, both catheters measured essentially equal pressures at rest, during venous stasis, and during a combination of venous stasis and compression. For long‐term assessment, the Slit system required as many as three saline flushes, whereas the fiber optic system measured pressures continuously without manipulation. We conclude that the fiber optic system is as accurate as the Slit catheter for measuring tissue fluid pressures at rest. In addition, the fiber optic system offers distinct advantages over conventional fluid‐filled systems for measuring intramuscular pressures due to a lack of hydrostatic pressure artifacts caused by limb position and to the lack of flushing for long‐term measurements.
The effect of anaesthesia on the bone blood flow of the rabbit
Authors: Davis T. R. C. , Holloway I. , Pooley J. 
Published: February 2005

AbstractThe effect of anaesthesia on the rate of bone blood flow in the rabbit was studied. Two estimates of bone blood flow were performed, using 15 μm radioactively labelled microspheres, in three groups of rabbits. The first group was anaesthetised and the interval between the two estimates was 5 min. The second group was also anaesthetised but the interval between estimates was 60 min. The third group of rabbits was conscious and the interval between the two estimates was 4 h. In the first group, small uniform falls in whole bone blood flow were observed (mean change = −5%). In the second group, larger and less predictable reductions were observed (mean change = −24%). In the third group (conscious), little change was observed in whole bone blood flow during the 4‐h experiment (mean change = + 7%). It is concluded that substantial falls can occur in bone blood flow in the rabbit during a 1‐h anaesthetic. If bone blood flow is to be monitored under anaesthesia, then the effect of the anaesthetic on bone blood flow must be accurately defined. In conscious rabbits, estimates of whole bone blood flow performed at an interval of 4 h under control conditions will give reproducable results.
Chronic achilles paratenonitis with tendinosis: An experimental model in the rabbit
Authors: Backman Clas , Boquist Lennart , Fridén Jan , Lorentzon Ronny , Toolanen Göran 
Published: February 2005

AbstractAn experimental model for inducing chronic Achilles paratenonitis with tendinosis in the rabbit is presented. Thirteen rabbits were exercised in a kicking machine producing passive flexions and extensions of the ankle joint. Active contractions of the triceps surae muscles were induced by electric stimulation via surface electrodes. The animals were exercised for 5 to 6 weeks, with a rate of 150 flexions and extensions per minute for 2 h, three times a week. Light microscopic examination showed degenerative changes of the tendon, and increased number of capillaries, infiltrates of inflammatory cells, edema, and fibrosis in the paratenon. We conclude that chronic Achilles paratenonitis with tendinosis can be experimentally induced in a standardized manner in rabbits.
Acute hemarthrosis: A histological, biochemical, and biomechanical correlation of early effects on the anterior cruciate ligament in a rabbit model
Authors: Ishizue Kenneth K. , Lyon Roger M. , Amiel David , Woo Savio L‐Y. 
Published: February 2005

AbstractThe early histological, biochemical, and biomechanical characteristics of the anterior cruciate ligament (ACL) were determined in a rabbit model of acute hemarthrosis. The ACLs of 19 rabbits were given seven consecutive daily knee injections of 2 ml of fresh autologous blood, and then compared to contralateral ACLs from control knees injected with 2 ml of lactated Ringer's solution daily for 7 days. The rabbits were then sacrificed. Synovial proliferation with iron deposition within synoviocytes was observed; however, the architecture of the ACL was maintained. Additionally, the total collagen content, collagenase activity, and biomechanical properties of the ACL were unaltered.