Quantification of the joint effects of mixtures of hepatotoxic agents: evaluation of a theoretical model in mice.
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Acetaminophen↗
SEARCH · PubMed Health
Results for “joint quantification”
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Quantification of first tarsometatarsal joint stiffness in hallux valgus patients.
OBJECTIVE: Comparison of the clinical mobility test of the first tarsometatarsal joint with Doppler Imaging of Vibrations measurement of the stiffness of this joint in hallux valgus patients. DESIGN: Clinical testing of first tarsometatarsal joint mobility was related to independent Doppler Imaging of Vibrations measurement of first tarsometatarsal joint stiffness. BACKGROUND: Hypermobility of the first tarsometatarsal joint has consequences for the surgical treatment of hallux valgus deformity. However, the clinical test is subjective. Doppler Imaging of Vibrations could be helpful in quantification of the stiffness of this joint. METHODS: Clinical examination of the mobility of 32 first tarsometatarsal joints in 20 hallux valgus patients was compared with Doppler Imaging of Vibrations stiffness measurements performed by an independent observer. RESULTS: There was a statistically significant relation between the clinical test and the stiffness measurement by Doppler Imaging of Vibrations. CONCLUSION: Doppler Imaging of Vibrations proves to be a method to quantify first tarsometatarsal joint stiffness and could contribute to a rational policy for the surgical treatment of hallux valgus deformity. RELEVANCE: The clinical test to establish hypermobility of the first tarsometatarsal joint is subjective. Doppler Imaging of Vibrations offers objective criteria and quantification of first tarsometatarsal joint stiffness. This provides additional information for the choice of the surgical procedure to correct hallux valgus deformity.
Biomechanical Phenomena↗
Heat distribution over normal and abnormal joints: thermal pattern and quantification.
We have identified regular thermal patterns over normal knee, ankle, and elbow joints and demonstrate how synovitis affecting these joints may be identified by alteration or loss of the thermal pattern. Sixty healthy volunteers were thermographed on a total of 190 occasions, and 614 out of 618 joints conformed to the normal thermal pattern. Eighty-five patients with synovitis of at least one of the specified joints were thermographed on a total of 339 occasions, and 322 out of 1362 thermograms were abnormal. No joint with clinical evidence of synovitis had a normal thermal pattern. As temperature-based parameters have been found to show marked diurnal variation and relative frequency distributions do not have this drawback, we suggest that quantification of synovitis by thermography should in future be based on abnormalities of thermal pattern rather than absolute skin temperature values.
Adolescent↗
Diagnostic value of quantitative sacroiliac joint scintigraphy in brucellosis
Increased bone activity in the sacroiliac joints has been shown to be a sensitive method for detecting sacroiliitis in brucellosis. Because symmetrically increased uptake usually is difficult to detect, this study was performed to improve the sensitivity by quantifying sacroiliac joint uptake. Quantification was accomplished by normalizing sacroiliac joint activity to activity in the lumbar spine and sacrum. From rectangular regions of interest over a standardized posterior pelvic view, the ratios of the sacroiliac:lumbar spine and sacroiliac:sacrum were calculated. Abnormal sacroiliac joint uptake was defined as uptake greater than the mean +2 SD of normal. This was applied to 79 patients with brucella sacroiliitis. The quantitative approach was compared with visual interpretation. Of the 16 patients in the age group of 5 to 19 years, 7 patients had visual evidence of sacroiliitis and 9 patients had positive evidence by sacroiliac-sacrum and 12 by sacroiliac-lumbar spine quantification. Of 21 patients who were 20 to 30 years old, 10 patients had positive visual evidence, whereas 17 and 20 patients had positive evidence of sacroiliitis by sacroiliac-sacrum and sacroiliac-lumbar spine, respectively. Of 42 patients who were 31 to 85 years old, 24, 32, and 36 patients had positive evidence of sacroiliitis by visual inspection, sacroiliac-sacrum, and sacroiliac-lumbar spine, respectively. Thus, the quantitative approach increased the sensitivity in diagnosing Brucella sacroiliitis in all age groups by 31.3%, 47.6%, and 28.6%, respectively, for sacroiliac-lumbar spine and by 12.5%, 33.3%, and 19%, respectively, for sacroiliac-sacrum.
Journal Article↗
Report of the 16th meeting of the British Inflammation Research Association. Topic: measuring bone and joint disease progression: biochemical quantification.
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Anti-Inflammatory Agents, Non-Steroidal↗
Influence of physical activity-related joint stress on the risk of self-reported hip/knee osteoarthritis: a new method to quantify physical activity.
BACKGROUND: The relationship between physical activity (PA) and the development of hip/knee osteoarthritis (OA) has not been clearly defined. The purpose of this study was to develop a method to quantify PA-related joint stress and to assess its influence on the risk of hip/knee OA. METHODS: Participants in a large longitudinal study, without knee/hip OA (n = 5284), were asked about their PA participation in 1986. PA-related joint stress was calculated using information on the frequency, intensity, and duration of individual types of PA, and incorporated a quantification of joint stress. Self-reported, physician-diagnosed hip/knee OA was ascertained by survey in 1990, 1995, and 1999 (average length of follow-up: 12.8 years). METHODS: The joint stress PA score was not associated with an increased risk of hip/knee OA. Also, among walkers and runners there was no association between the frequency, pace, or weekly training mileage and hip/knee OA. Older age, previous joint injury and surgery, and higher body mass index were confirmed as independent risk factors for hip/knee OA. CONCLUSIONS: Participation in PA as an adult does not increase the risk of hip/knee OA and there does not seem to be a threshold of increasing risk with increased training among walkers and runners.
Female↗
Bone and joint disease progression: detection, imaging and quantification.
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Bone Diseases↗
Objective clinical evaluation of function. Gait analysis.
Automated gait analysis allows us to document and quantify objectively normal gait, functional deficits, and patient response to therapeutic intervention. Instrumentation for this analysis at the Mayo Clinic Gait Laboratory includes three-dimensional electrogoniometers for measurement of relative joint rotation at the hip, knee, and ankle; footswitches that record foot-floor contact sequences; instrumented mats that measure step length and width; piezoelectric force plates for measurement of floor reaction forces; and two walkways that simulate a variety of ground conditions. We use a DEC-PDP 11/34 computer for acquisition, storage, and analysis of data and for generation of a gait report form that displays a patient's results relative to normal and previous evaluations. Applications of these techniques include assessment of function preoperative and postoperative total joint arthroplasty, quantification of gait faults, and documentation of effectiveness of exercise and gait training techniques. We have demonstrated the reliability of the techniques, accumulated a sizeable normal data bank, and developed a concise, effective data summary for communication with referring practitioners.
Amputees↗
Crystal-induced inflammation in canine joints. I. An experimental model with quantification of the host response.
Injection of sodium urate or calcium pyrophosphate crystals into the stifle joints of anesthetized dogs almost invariably induced an acute exudative response. This response was quantified by serial measurements of intra-articular pressure, pH and leukocyte concentration. Pressure rose progressively and reflected intra-articular volume increase. The hydrogen ion concentration increased as the reaction progressed and correlated in a given exudate with the leukocyte concentration. Analysis of sequential physiologic and biochemical changes occurring in this model of crystal-induced inflammation may provide insight into the mechanisms of acute gouty arthritis in man.
Animals↗
A comparative analysis of bone and cartilage metabolism in two strains of guinea-pig with varying degrees of naturally occurring osteoarthritis.
OBJECTIVE: To evaluate the interaction of bone and cartilage in knee osteoarthritis (OA) pathogenesis in two guinea-pig strains with appreciable differences in bone metabolism. DESIGN: Two guinea-pig strains were evaluated for their susceptibilities to OA using semi-quantitative histological grading of knee joints and quantification of biomarkers including urinary excretion of hydroxylysyl-pyridinoline (HP) and lysyl-pyridinoline (LP) collagen cross-links, serum osteocalcin (OC), and synovial fluid levels of keratan sulfate (KS). RESULTS: At 12 months of age, Strain 13 guinea-pigs had minimal to mild histological evidence of OA compared to the Hartley strain guinea-pigs. The Hartley strain, with more severe OA, had a higher rate of bone formation (serum osteocalcin) and bone resorption (HP and LP) evident at a young age with persistence of a greater rate of bone formation at 12 months of age. The Strain 13 possessed much thicker subchondral bone at the outset (2 months) compared to the Hartley; however, the Hartley strain showed the greatest increase in subchondral bone thickness coincident with the development of cartilage degeneration. Thus, the process of subchondral bone thickening, in contrast to the absolute initial subchondral bone thickness, was a hallmark of OA in the guinea-pig. Moreover, Strain 13 had lower intraarticular proteoglycan turnover. Levels of synovial fluid keratan sulfate were positively correlated with the severity of histological OA. CONCLUSIONS: This pilot study represents the first evidence of differential susceptibility to OA in guinea-pigs. Comparison of these two strains of guinea-pig has revealed that increased metabolism within the affected tissues, cartilage and bone, is associated with the development and progression of OA. This work demonstrates that the Strain 13 is a viable age-matched control to the Hartley strain and merits a more in depth evaluation of the contribution of bone and bone metabolism to OA.
Amino Acids↗
Quantification of mRNA levels in joint capsule and articular cartilage of the murine knee joint by RT-PCR: kinetics of stromelysin and IL-1 mRNA levels during arthritis.
We developed a method to isolate well defined joint specimens from different compartments of normal and arthritic murine knee joints in which mRNA levels of stromelysin and IL-1 were semiquantified using RT-PCR. Joint capsule specimens were isolated on medial and lateral sides of the patella with a biopsy punch. Cartilage layers were isolated from patellae after a mild decalcification with EDTA. EDTA treatment had no effect on the amount and efficiency of amplification of mRNA when tested on isolated chondrocytes. After induction of experimental arthritis, stromelysin mRNA was elevated approximately 50 times in both joint capsule and cartilage. IL-1 was elevated 100 times in joint capsule but only 10 times in cartilage. Kinetic analysis of mRNA levels in cartilage during arthritis showed a prolonged elevation of stromelysin mRNA compared to IL-1. The variation in mRNA levels between joints of individual mice proved to be low, showing that sampling of the specimens and subsequent RT-PCR can be performed reliably. The current method offers a valuable approach to study gene expression in knee joints during murine experimental arthritis.
Animals↗
In vivo quantification of the cat patellofemoral joint contact stresses and areas.
A new method for in vivo measurement of patellofemoral joint contact areas, stresses, and patellar displacements, with joint loading approximating physiologic conditions was developed. Joint contact measurements were obtained using pressure sensitive film inserted directly between articular joint surfaces. Two-dimensional joint kinematics were measured using a high-speed video based motion analysis system. Joint loading, provided by quadriceps muscle stimulation, was measured with an implantable force transducer (IFT). Variations in joint mechanics as a function of joint flexion angle, joint loading and joint stability (anterior cruciate ligament intact or transected) were determined for four adult male cats. The contact measurements obtained with the pressure sensitive film displayed high repeatability with a standard error of +/- 6.8% of the mean value of the median pressure and +/- 4.4% of the mean contact area value. Substantial differences in joint mechanics were reliably detected with the new technique. The influence of experimental procedures, such as incisions in the joint capsule and insertion of pressure sensitive film between the articular surfaces, produced minimal changes in the joint kinematics during muscular contraction.
Animals↗
ProteoformDB: A Built-In Application to Generate Proteoform Database.
Proteins play essential functions through their complex regulations on cell-type-specific expression, localization, and molecular complexes. Protein complexity is further enhanced by proteoforms, which are the diverse molecular forms that each gene can produce through genomic alterations, transcriptional variations, translational regulations, and protein modifications. Profiling of proteoforms is a promising method for gaining a deeper understanding of the role of proteins in biological pathways and disease mechanisms. Here, we developed ProteoformDB, an application tool for generating proteoform databases, and we cataloged a total of over one million unique single-site human proteoforms. We showed that ProteoformDB can serve as a valuable resource to document the experimentally identified proteoforms in a database, supporting protein characterization in quantitative proteomics for both total protein abundances and modified protein forms.
Humans↗
Model dependence in quantification of spike interdependence by joint peri-stimulus time histogram.
Multineuronal recordings have enabled us to examine context-dependent changes in the relationship between the activities of multiple cells. The joint peri-stimulus time histogram (JPSTH) is a much-used method for investigating the dynamics of the interdependence of spike events between pairs of cells. Its results are often taken as an estimate of interaction strength between cells, independent of modulations in the cells' firing rates. We evaluate the adequacy of this estimate by examining the mathematical structure of how the JPSTH quantifies an interaction strength after excluding the contribution of firing rates. We introduce a simple probabilistic model of interacting point processes to generate simulated spike data and show that the normalized JPSTH incorrectly infers the temporal structure of variations in the interaction parameter strength. This occurs because, in our model, the correct normalization of firing-rate contributions is different than that used in Aertsen, Gerstein, Habib, and Palm's (1989) effective connectivity model. This demonstrates that firing-rate modulations cannot be corrected for in a model-independent manner, and therefore the effective connectivity does not represent a universal characteristic that is independent of modulation of the firing rates. Aertsen et al.'s (1989) effective connectivity may still be used in the analysis of experimental data, provided we are aware that this is simply one of many ways of describing the structure of interdependence. We also discuss some measure-independent characteristics of the structure of interdependence.
Brain↗
Quantification of early subclinical limited joint mobility in diabetes mellitus.
Limited joint mobility (LJM) has been described in juvenile diabetic patients by Rosenbloom et al.; similar abnormalities are also present in adult diabetes. This modification may be associated with a high risk of microvascular complications. We tested the use of a goniometer in measuring subclinical joint limitation in 50 adult diabetic patients without overt, i.e., clinically evident, LJM as described by these authors. This diabetic population was compared with 118 nondiabetic adult controls. We found significant changes in hand mobility between the two groups for wrist flexion and extension of the 3rd and 5th fingers (P less than 0.001). Age was correlated to wrist flexion, wrist extension, and proximal interphalangeal flexion of the little finger. Wrist extension correlated with duration of diabetes (r = -0.37, P less than 0.01). Heavy manual activities significantly limited all motions except wrist and 5th finger metacarpophalangeal flexion. Early systematic examination by goniometry may prove to be a sensitive, quantitative, and inexpensive way of detecting joint stiffness at an early stage.
Adult↗
Gender differences in active musculoskeletal stiffness. Part I. Quantification in controlled measurements of knee joint dynamics.
Active females demonstrate increased risk for musculoskeletal injuries relative to equivalently-trained males. Although gender differences in factors such as passive laxity, skeletal geometry and kinematics have been examined, the effect of gender on active muscle stiffness has not been reported. Stiffness of the active quadriceps and hamstrings musculature were recorded during isometric knee flexion and extension exertions from twelve male and eleven female subjects. A second-order biomechanical model of joint dynamics was used to quantify stiffness from the transient motion response to an angular perturbation of the lower-leg. Female subjects demonstrated reduced active stiffness relative to male subjects at all torque levels, with levels 56-73% of the males. Effective stiffness increased linearly with the torque load, with stiffness increasing at a rate of 3.3 Nm/rad per unit of knee moment in knee flexion exertions (hamstrings) and 6.6 Nm/rad per unit of knee moment extension exertions (quadriceps). To account for gender differences in applied moment associated with leg mass, regressions analyses were completed that demonstrated a gender difference in the slope of stiffness-versus-knee moment relation. Further research is necessary to identify the cause of the observed biomechanical difference and implications for controlling injury.
Adult↗
Quantification of the uncertainties in resultant joint moments computed in a dynamic activity.
Resultant joint moments are an important variable with which to examine human movement, but the uncertainty with which resultant joint moments are calculated is often ignored. This paper presents a procedure for examining the uncertainty with which resultant joint moments are calculated. The uncertainty was calculated by changing the parameters and variables required to compute the resultant joint moments, by amounts relating to their estimated uncertainties, and then quantifying the resulting change in the resultant joint moments. The procedure was applied to the elbow joint during loaded elbow flexion executed at maximum volitional speed. For this activity, the estimated moments were most sensitive to uncertainties in the derivatives of the position data. A number of other sources of error and uncertainty were identified which warrant further investigation. The protocols outlined in this study are applicable to other activities.
Biomechanical Phenomena↗
From Peaks to Power: Systematic Evaluation of Chromatographic Sampling Reveals Determinants of Quantification and Biological Discovery in DIA Proteomics.
Modern DIA proteomics increasingly emphasizes throughput and depth for large-cohort studies, but methods are often optimized using proxy metrics that can mask losses in quantifiable signal and statistical power. Here, we evaluate how data points per peak and other chromatographic features jointly contribute to quantification and downstream biological discovery. Using a matrix-matched calibration curve dataset, we checked how the number of data points per peak (DPPP) affects the limits of detection and quantification (LOD/LOQ). Reduced DPPP minimally affected LOD but substantially degraded LOQ. Feature modeling and nonparametric association analyses identified precursor peak area as the strongest feature-level predictor of LOQ, whereas DPPP showed weaker and context-dependent effects. Simulations of chromatographic peak integration recapitulated these trends, showing that increased sampling primarily improves integration precision, while quantitative accuracy is strongly governed by peak height and peak shape. Finally, when comparing 20 cancer vs 20 control plasma samples processed with Seer Proteograph, the decrease in DPPP led to a loss of statistical significance for proteins with low-abundance precursors. These findings argue that DIA optimization should prioritize LOQ and statistical power metrics─not identifications alone─by balancing sampling density with chromatographic peak height and quality to maximize useful biological signal.
Proteomics↗