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A sonographic method for diagnosis, follow-up and quantification of normal and hypertrophied masseter muscles is presented. This technique lends itself to diagnosis of macroscopic structural alterations of the muscle as well as tumors in the vicinity. Functional or microscopic tissue changes like trigger points in myofacial pain-dysfunction syndrome cannot be detected sonographically.
We used the severe combined immunodeficient (SCID) mouse model to assess the effect of interleukin-4 (IL-4) or IL-10 injection on cartilage degradation and mononuclear cell (MNC) recruitment to human rheumatoid synovium in vivo. Human rheumatoid synovium and cartilage from five rheumatoid arthritis patients, obtained after joint replacement surgery, were engrafted subcutaneously to 6-8-week-old SCID CB17 mice. Synovial tissues were injected with recombinant human IL-4 (rhIL-4, 100 ng; rhIL-10, 100 ng), both cytokines, or tumour necrosis factor-alpha (TNF-alpha) (1000 U), or phosphate-buffered saline twice a week for 4 weeks. The graft was removed and immunochemical analysis was carried out to assess intracellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and E-selectin expression. Moreover, cartilage degradation was assessed through the quantification of the erosion surface on a computerized image of the engrafted cartilage at high power view. MNC recruitment in the synovial tissue was determined by labelling blood MNC with indium-111 before their intraperitoneal injection. The activity obtained in the region of the graft were determined with a gamma camera 72 hr postinjection. The results are expressed as a percentage of initial injected activity. After 4 weeks we observed a decrease of cartilage area in controls (77 +/- 8%), inhibited after injection of IL-4, IL-10, or both cytokines (90 +/- 3%, 89.1 +/- 4%, 89.2 +/- 5% respectively), and 57 +/- 17% after TNF-alpha injection. The % MNC activity in the graft decreased to 77 +/- 81% (NS), 9 +/- 4% (P < 0.003) and 19 +/- 6% (P < 0.007) compared with untreated synovial tissue after treatment with IL-4, IL-10, or both cytokines, respectively. Moreover, IL-10 but not IL-4 decreased the expression of ICAM-1 but not VCAM-1 or E-selectin by synovial cells. These results suggest that IL-10 and IL-4 could have chondroprotective properties, and that IL-10 but not IL-4 inhibits MNC traffic towards the synovial tissue efficiently.
BACKGROUND: Measured bone density correlates well with the mechanical properties of the bone. Our objective was to evaluate optical densitometry as a method of measuring the periprosthetic bone density of the tibial platform in total knee replacement using serial dual-energy X-ray absorptiometry (DXA) as the reference test. METHODS: 30 patients who underwent a cemented total knee replacement were followed up for over 2 years. Standard radiographs of the knee were obtained at 12 and 24 months. These were photographed with a digital camera and enhanced with image processing software. A DXA scan was performed at the same time as the reference method. 3 regions of interest were defined under the tibial plateau (medial, lateral and stem positions). RESULTS: After 24 months of follow-up there was a significant decrease in density in the 3 regions, both with the optical and DXA methods. The concordance between methods was studied using Bland and Altman plots, Cronbach's alpha and intraclass correlation coefficients resulted in values from 0.72 to 0.87, depending on the region and the follow-up time. INTERPRETATION: Quantification of optical density values with a standardized measurement system on conventional radiographs is a reliable and efficient method of determining the bone mineral density.
Blastocyst-derived pluripotent embryonic stem (ES) cells of the mouse can be induced to differentiate in culture into a variety of cell types, including cardiac muscle cells. In the embryonic stem cell test (EST) the capacity of ES cells of the mouse cell line D3 to differentiate into contracting cardiomyocytes is used to assess the embryotoxic potential of test compounds and in addition, the effects on the viability of ES cells and differentiated mouse fibroblasts (cell line 3T3) are compared. The three endpoints are used to classify the embryotoxic potential of chemicals after 10 days of exposure: (i) the inhibition of differentiation of ES cells into cardiomyocytes (ID50) and (ii) the decrease of viability of 3T3 cells (IC503T3) and (iii) ES cells (IC50D3) in a MTT cytotoxicity test. Applying linear analysis of discriminance, a biostatistical prediction model (PM) was developed to assign test chemicals to three classes of embryotoxicity. In an international validation study funded by ECVAM it could be demonstrated that the EST can predict the embryotoxic potential of a test compound as good as frequently used mammalian systems based on pregnant animals. In a joint project with major German pharmaceutical companies we are attempting to improve the EST by establishing molecular endpoints of differentiation (e.g. cardiac, neuronal, chondrogenic) in cultured ES cells. We have studied the expression of tissue specific proteins in ES cell cultures in the presence of embryotoxic chemicals by immunofluorescent antibody techniques, e.g. FACS analysis. The other groups are focusing on endogenous gene expression in early development by RT-PCR methods or the DNA microarray technique. The results obtained recently using molecular markers specific for cardiac differentiation and employing intracellular flow cytometry for quantification will be presented. Molecular endpoints will allow improvement of the EST by measuring gene expression patterns in a small number of murine ES cells.
Clinical evaluation of humeral head translation relies mainly on manual tests to measure laxity in the human shoulder. The purposes of this study were to determine whether side-to-side differences exist in anterior humeral head translation in professional baseball pitchers, to compare manual laxity testing with stress radiography for quantifying humeral head translation, and to test intrarater reliability of the manual humeral head translation and stress radiography tests. Twenty professional baseball pitchers underwent bilateral manual anterior humeral head translation and stress radiographic tests. Stress radiography was performed by imparting a 15-daN anterior load to the shoulder in 90 degrees of abduction with both neutral and 60 degrees of external rotation and recording the glenohumeral joint translation at rest and under stress in each position. Eight subjects were retested to assess the reliability of these methods. Results showed no significant difference between the dominant and nondominant extremity in the amount of anterior humeral head translation measured manually and with stress radiography, nor significant correlation between anterior humeral head translation measured manually and by stress radiography. Test-retest reliability was moderate-to-poor for the manual humeral head translation test and moderate for stress radiography.
OBJECTIVE: The objective of our study was to determine the merit of the fat fraction of axial bone marrow measured by Dixon quantitative chemical shift imaging (Dixon QCSI) as a clinical parameter to quantitatively assess the extent of skeletal involvement in type 1 Gaucher's disease. MATERIALS AND METHODS: Dixon QCSI was performed in 30 adult patients (age range, 18-69 years; mean, 39 years) with type 1 Gaucher's disease who were untreated. The relationship between the mean value of the fat fraction in vertebrae L3, L4, and L5 and the presence, absence, and severity of clinical bone complications (chronic bone pain, bone crisis, fracture, avascular necrosis, and joint replacement) as well as the conventional MR imaging of bone marrow involvement were studied. Also the relationship of fat fraction to sex, age, and other disease parameters (history of splenectomy, liver and spleen volume, plasma chitotriosidase, hemoglobin level, and platelet count) was evaluated. Our results were compared with the fat fraction of healthy volunteers. RESULTS: The fat fraction measured in patients with Gaucher's disease ranged from 0.08 to 0.40 (mean, 0.20). Bone complications occurred primarily in patients with a fat fraction of less than 0.23. Univariate logistic regression analysis indicated that for every decrease of 0.1 of the fat fraction, the risk of bone complications increased 85% (p < 0.05). The fat fraction was correlated with liver size, but no correlation with other disease parameters was found. In the patient population, the fat fraction was significantly lower than in the healthy population (range, 0.27-0.55; mean, 0.37; p < 0.001). CONCLUSION: The fat fraction of the lumbar spine when measured with Dixon QCSI is associated with the occurrence of bone complications. It may, therefore, be a clinically useful parameter.
Single and combined toxicity of copper-zinc, copper-cadmium, cadmium-lead, copper-carbendazim, and copper-carbendazimiprodione to the nematode Caenorhabditis elegans in soil was studied. The one-week population increase was estimated as the toxicity endpoint. The aim was to study the relationship between mixture interactions in the soil and the combined toxic effect. Soil sorption was quantified using the Freundlich adsorption constant. Joint toxicity patterns were quantified by comparing mixture effects to the effect of individual constituents and were related to total metal concentrations in the soil, water-soluble concentrations, and 0.01 M CaCl2-extractable concentrations. The metal with the highest adsorption constant influenced the sorption of metal with the lowest adsorption constant when both were combined, indicating interaction. Consequently, both the composition of the mixture as well as the relative toxicity of individual mixture constituents differed between total, water-soluble, and CaCl2-extractable concentrations, which was taken into account in the data quantification procedure that was applied. Both the additive and the independent model were generally inadequate to describe the effects of metal mixtures. Compared to the additive model, synergism was observed at dose levels higher than the median effect isobole. A general relationship between mixture interactions in the soil and the combined toxicity was not found.
OBJECTIVE: T scores (an indicator of the difference between patients and young healthy subjects) and Z scores (an indicator of the difference between patients and age-matched healthy subjects) are used in the diagnosis of osteoporosis and form the current basis for the definition of osteoporosis by the World Health Organization. We tested the feasibility of using T and Z scores derived from quantitative cartilage imaging with magnetic resonance imaging (MRI) for the diagnosis of osteoarthritis (OA). METHODS: High-resolution MR images of tibial cartilage were acquired from 126 young healthy adults (ages 20-35 years), 24 age-matched elderly healthy adults (ages 50-75 years), 7 OA patients prior to tibial osteotomy, and 7 OA patients prior to knee arthroplasty. Cartilage volume, thickness, surface area, and original joint surface area (before onset of disease) were determined in the medial and lateral tibia. RESULTS: The cartilage volume of the medial tibia of osteotomy patients with varus malalignment displayed moderate T scores (-1.0), and more negative T scores (-3.8) were observed in knee arthroplasty patients with varus malalignment. Normalization of the cartilage volume to the original joint surface area substantially enhanced the scores in patients undergoing osteotomy (-2.3) and in patients undergoing knee arthroplasty (-5.5), and this was superior to the normalization ratios of cartilage volume to body height and cartilage volume to body weight, in terms of distinguishing the loss of articular cartilage. CONCLUSION: Quantitative analysis of OA by MRI is feasible using T and Z scores. However, cartilage volume should be normalized to the individual joint surface area in order to maximize the discriminatory power of this technique for the diagnosis of OA.
In view of adding to ultrasonographic scanning of the neonatal hip through various projections and in order to improve the measurement and quantification base of the normal and dysplastic neonatal hip, the research was conducted on anatomic hip preparation of full-term still-born baby. The research on a clinical sample covered 600 ultrasonically examined normal and dysplastic hips. Ultrasonographic serial scanning was performed on various planes using linear transducer with 5 and 7.5 MHz and with or without a water pillow. On the clinical sample of the particular group various projections were applied and results compared with projections obtained on anatomic preparation. Concluded was that with several projections frontal sonographic projections tomographic examination of the hip joint could be performed. Better insight of the position of the femoral head at rest in neutral and flexed positions, the relative stability of the hip with motion and stress and the depth and configuration of the bony and cartilaginous portions of the acetabulum could be obtained if, besides frontal sections, cross sections of the hip were used. Sufficient measurement data echosonogrametric parameters were indispensable for an adequate definition of all hip joint structures.
The purpose of this investigation was to use relative phase dynamics to evaluate gait in individuals with a reconstructed anterior cruciate ligament (ACL) during walking and running. Relative phase dynamics can describe the coordination strategies between the interacting segments at the lower extremity. Ten subjects who had undergone ACL reconstruction using the central third of their patellar tendon and ten healthy controls walked and ran on a treadmill at a self-selected pace. Relative phase dynamics were calculated for the foot-shank and shank-thigh coordinative relationships. Statistical differences between the groups were noted for the foot-shank relationship (p < 0.05) during both walking and running and for the shank-thigh relationship (p < 0.05) during walking. Our results indicate that current ACL reconstructive techniques may result in altered relative phase dynamics. These changes in relative phase dynamics could be related to a loss of sensory information about joint position and velocity that is typically provided by the intact ACL. Additionally, relative phase adaptations could be a learned response from the early stages of postsurgical rehabilitation. Relative phase dynamics provide quantitative information about the dynamic status of the ACL-reconstructed knee that cannot be gained from the conventional time-series evaluation of gait analysis data. Relative phase dynamics measures should supplement the conventional gait analysis measures that are used today for the clinical evaluation of the functional dynamic stability of the reconstructed knee. The examination of relative phase dynamics could be clinically important for the quantification of new ACL surgical interventions and of patient performance at various stages of rehabilitation. Further research should incorporate relative phase dynamics to understand the influence of ACL reconstruction on coordination and functional patient outcomes.
Current evidence suggests that host defense in respiratory mycoplasmosis is dependent on both innate and humoral immunity. To further delineate the roles of innate and adaptive immunity in antimycoplasmal defenses, we intranasally infected C3H/HeSnJ-scid/scid (C3H-SCID), C3H/HeSnJ (C3H), C57BL/6J-scid/scid (C57-SCID), and C57BL/6N (C57BL) mice with Mycoplasma pulmonis and at 14 and 21 days postinfection performed quantitative cultures of lungs and spleens, quantification of lung lesions, and histopathologic assessments of all other major organs. We found that numbers of mycoplasmas in lungs were associated with genetic background (C3H susceptible, C57BL resistant) rather than functional state of adaptive immunity, indicating that innate immunity is the main contributor to antimycoplasmal defense of the lungs. Extrapulmonary dissemination of mycoplasmas with colonization of spleens and histologic lesions in multiple organs was a common occurrence in all mice. The absence of adaptive immune responses in severe combined immunodeficient (SCID) mice resulted in increased mycoplasmal colonization of spleens and lesions in extrapulmonary sites, particularly spleens, hearts, and joints, and also reduced lung lesion severity. The transfer of anti-M. pulmonis serum to infected C3H-SCID mice prevented extrapulmonary infection and disease, while the severity of lung lesions was restored by transfer of naive spleen cells to infected C3H-SCID mice. Collectively, our results strongly support the conclusions that innate immunity provides antimycoplasmal defense of the lungs and humoral immunity has the major role in defense against systemic dissemination of mycoplasmal infection, but cellular immune responses may be important in exacerbation of mycoplasmal lung disease.
BACKGROUND: No established, non-invasive diagnostic procedure for quantifying focal cartilage defects is currently available. OBJECTIVE: To test the accuracy of quantitative magnetic resonance imaging (qMRI) for reliable determination of cartilage defect size in various compartments of the human knee. METHODS: 24 tibial and patellar cartilage plates were harvested during knee arthroplasty. 74 cylindrical defects with diameters of 3, 5, and 8 mm were created with a punch. In 15 specimens (51 defects), the cartilage cylinders (inside the punch) were removed (approach 1), while in 9 specimens (23 defects) the surrounding tissue was removed mechanically and the cartilage cylinder was left in place (approach 2). All plates were imaged with a T(1) weighted water excitation gradient echo sequence at a resolution of 1.5 mm x 0.31 mm x 0.31 mm. The defect size was computed from the image data after interactive segmentation and compared with the known dimensions of the cylinders. RESULTS: Although there was a significant overestimation of the defect size by qMRI in 3 mm defects (mean (SD) +1.3 (0.58) mm = +/-42%; p<0.001), the overestimation was only +1.0 (0.57) mm (+/-21%; p<0.05) in 5 mm defects and +0.1 (0.39) mm (+/-4%; p = 0.31) in 8 mm defects (approach 1). Values were similar for approaches 1 and 2 and for patellar and tibial cartilage plates. CONCLUSIONS: These findings show that qMRI allows accurate quantification of focal cartilage defects. It may therefore represent a valuable tool in the diagnosis of traumatic cartilage lesions, osteochondrosis dissecans, and osteochondral fractures, and in monitoring their responsiveness to surgical or other treatments.
Synovial fluid (SF) and synovial tissue from 10 patients with juvenile rheumatoid arthritis were examined. The SFs were heterogeneous with respect to the degree of complement activation. Quantification of C3dg and the terminal complement complex revealed a positive correlation between activation of the early and the late parts of the cascade in all patients. The amount of C-reactive protein and the number of white blood cells in the SF correlated significantly with the degree of complement activation. Weak deposits of C3, C3dg, or terminal complement complex were observed in a few vessels in the synovial tissue from 5 of the patients. There was no correlation between complement activity in SF and in the corresponding tissue. Furthermore, there was no correlation between clinical activity in the joints and the degree of complement activation. It is concluded that there is a discrepancy between synovial tissue and synovial fluid with respect to complement activation. C-reactive protein may, to some extent, be responsible for activation in SF, and the accumulation of white blood cells may be due to complement activation products.
Wear particles generated after total joint arthroplasty activate monocyte/macrophages and incite formation of a granulomatous periprosthetic tissue associated with bone loss and implant loosening. This study tested the hypothesis that selective opsonization of orthopedic implant biomaterial wear particles by human serum proteins influences monocyte/macrophage activation. Serum protein binding to metallic, polymeric, and ceramic particles was determined by one-dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Individual proteins bound to particles were subsequently identified using two-dimensional SDS-PAGE, microsequencing techniques, and SWISS-PROT analysis. Effects of selective protein opsonization on particle-induced monocyte/macrophage activation were assessed by quantification of interleukin-1beta, interleukin-6, and tumor necrosis factor-alpha release. Results from one-dimensional gel analyses revealed distinct serum protein-binding patterns specific for each material tested. Two-dimensional gel analysis together with amino acid sequencing of the prominent protein species confirmed the presence of albumin and alpha-1-antitrypsin bound to all particles tested. In contrast to the metallic particles, apolipoprotein was a major species associated with polymeric particles. Opsonization of PMMA particles with purified preparations of each of the identified proteins showed that albumin significantly enhanced particle-induced monocyte/macrophage activation. These data confirm orthopedic biomaterial specific binding of human serum proteins and demonstrate that albumin exacerbates particle-induced monocyte/macrophage activation. Alterations in the chemical and surface properties of orthopedic biomaterials to modulate protein interactions may improve implant longevity.
OBJECTIVE: To compare positron emission tomography (PET) and magnetic resonance imaging (MRI) in the evaluation of inflammatory proliferation of synovium. METHODS: Ten patients (mean +/- SD age 36 +/- 13 years) with inflammatory joint disease and with clinical signs of inflammation of the joint were studied. A new tracer for cellular proliferation, methyl-(11)C-choline ((11)C-choline), and a widely used tracer for the detection of inflammation and cancer, 2-(18)F-fluoro-2-deoxy-D-glucose ((18)F-FDG), were applied for PET imaging, and the results were compared with the findings from gadolinium diethylenetriaminepentaacetic acid-enhanced MR images. The uptake of (11)C-choline and (18)F-FDG in the inflamed synovium was measured and expressed as the standardized uptake value (SUV) and the kinetic influx constant (K(i)) obtained from graphic analysis, and these values were compared with quantitative values on MRI. Synovial volumes were measured on the coronal contrast-enhanced T1-weighted MR images using the standard software of the MR imager. RESULTS: All patients showed high accumulation of both (11)C-choline and (18)F-FDG at the site of arthritic changes, where quantification of the tracer uptake was performed. The SUV of (11)C-choline was 1.5 +/- 0.9 gm/ml (mean +/- SD; n = 10) and the SUV of (18)F-FDG was 1.9 +/- 0.9 gm/ml (n = 10) (P = 0.017). The K(i) of (11)C-choline (mean +/- SD 0.048 +/- 0.042 minute(-1)) was 8-fold higher than the K(i) of (18)F-FDG (0.006 +/- 0.003 minute(-1)) (P = 0.009). Both the uptake of (11)C-choline and the uptake of (18)F-FDG correlated highly with the volume of synovium; the highest correlation was observed with the K(i) of (11)C-choline (r = 0.954, P < 0.0001). CONCLUSION: In the use of PET scans,(11)C-choline can be regarded as a promising tracer for quantitative imaging of proliferative arthritis changes. Nevertheless, subsequent prospective studies with larger numbers of patients are necessary to further characterize the relationship between the findings on PET imaging and the clinical and functional measures of inflammation.
Quantification of arthritic pain can be very useful in elucidating the mechanisms of arthritis and in assessing the effect of anti-arthritic medication or treatment. Here we report a novel method that allows convenient measurements of the severity of arthritic pain in voluntarily walking rats. We constructed a device to measure the weight load on each leg while the animal was walking through a path, the bottom of which was equipped with strain gauge weight sensors. Using this device, we measured the weight load on the right hind leg before and after induction of arthritis by carrageenan injection into the knee joint cavity of this leg. The carrageenan injection resulted in a significant reduction of weight load on the affected leg; the load decreased to the minimum level at 4 h after the injection and gradually returned to the pre-injection level by the fifth day. Intraperitoneal administration of morphine at 5.5 h after carrageenan injection could reverse the weight load change. These results suggest that our new device is an effective tool for convenient measurements of arthritic pain in dynamic conditions like walking.
Bone ingrowth into titanium fiber mesh porous-surfaced canine total hip replacement prostheses was evaluated and quantified using a computer assisted image analysis system attached to a scanning electron microscope equipped with a back scattered electron detector. Excellent contrast between the bone, the porous metal and the soft tissues resulted in the backscatter mode, allowing easy differentiation of these components in real time by the image analysis based on gray scales. By three weeks the mean (+/- standard deviation) amount of bone ingrowth expressed as a percentage of porous layer measured 7.2% (+/- 1.5%) for the acetabular components, and 3.9% (+/- 1.7%) for the femoral components. At six weeks the amount of bone ingrowth increased to 10.5% (+/- 1.3%) for the acetabular components and 8.5% (+/- 1.4%) for the femoral components. Cementless prosthetic fixation using porous surfaced prostheses holds great promise in joint replacement surgery, and the ability to quantitate the amount of bone ingrowth will permit the evaluation of the efficacy of various techniques to improve bone ingrowth.
Unexpected changes in flexor-extensor muscle activation synergies during slope walking in the cat have been explained previously by 1) a reorganization of circuitry in the central pattern generator or 2) altered muscle and cutaneous afferent inputs to motoneurons that modulate their activity. The aim of this study was to quantify muscle length changes, muscle loads, and ground reaction forces during downslope, level, and upslope walking in the cat. These mechanical variables are related to feedback from muscle length and force, and paw pad cutaneous afferents, and differences in these variables between the slope walking conditions could provide additional insight into possible mechanisms of the muscle control. Kinematics, ground reaction forces, and EMG were recorded while cats walked on a walkway in three conditions: downslope (-26.6 deg), level (0 deg), and upslope (26.6 deg). The resultant joint moments were calculated using inverse dynamics analysis; length and velocity of major hindlimb muscle-tendon units (MTUs) were calculated using a geometric model and calculated joint angles. It was found that during stance in downslope walking, the MTU stretch of ankle and knee extensors and MTU peak stretch velocities of ankle extensors were significantly greater than those in level or upslope conditions, whereas forces applied to the paw pad and peaks of ankle and hip extensor moments were significantly smaller. The opposite was true for upslope walking. It was suggested that these differences between upslope and downslope walking might affect motion-dependent feedback, resulting in muscle activity changes recorded here or reported in the literature.