PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “joint quantification”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 217 records · Page 12Linked to original sources
PubMed2003

Mechanical factors in the initiation and propagation of tears of the rotator cuff. Quantification of strains of the supraspinatus tendon in vitro.

Differential strain has been proposed to be a causative factor in failure of the supraspinatus tendon. We quantified the strains on the joint and bursal sides of the supraspinatus tendon with increasing load (20 to 200 N) and during 120 degrees of glenohumeral abduction with a constant tensile load (20 to 100 N). We tested ten fresh frozen cadaver shoulders on a purpose-built rig. Differential variable reluctance extensometers allowed calculation of the strain. Static loading to 100 N or more increased strains on the joint side significantly more than on the bursal side. During glenohumeral abduction an increasing and significant difference in strain was measured between the joint and bursal sides of the supraspinatus tendon, which reached a maximum of 10.6% at abduction of 120 degrees. The joint side strain of 7.5% reached values which were previously reported to cause failure. Differential strain causes shearing between the layers of the supraspinatus tendon, which may contribute to the propagation of intratendinous defects that are initiated by high joint side strains.

Aged↗
PubMed2003

Quantification of shoulder and elbow passive moments in the sagittal plane as a function of adjacent angle fixations.

The goal of this study was an assessment of the shoulder and elbow joint passive moments in the sagittal plane for six healthy individuals. Either the shoulder or elbow joints were moved at a constant speed, very slowly throughout a large portion of their range by means of an industrial robot. During the whole process the arm was held fully passively, while the end point force data and the shoulder, elbow and wrist angle data were collected. The presented method unequivocally reveals a large passive moment adjacent angle dependency in the central angular range, where most everyday actions are performed. It is expected to prove useful in the future work when examining subjects with neuromuscular disorders. Their passive moments may show a fully different pattern than the ones obtained in this study.

Adult↗
PubMed1998

Production of T-cell cytokines at the single-cell level in patients with inflammatory arthritides: enhanced activity in synovial fluid compared to blood.

We used a newly developed, sensitive ELISPOT technique in order to estimate the number of cells producing interferon-gamma (IFN-gamma) and interleukin-4 (IL-4) in synovial fluid mononuclear cells (SFMC) and peripheral blood mononuclear cells (PBMC) in patients with rheumatoid arthritis (RA) and other inflammatory arthritides, and to correlate the results with clinical and laboratory parameters of disease activity. SFMC and PBMC were cultured either without stimuli or with a standardized dose of phytohaemagglutinin (PHA) for 6 h. Twenty-nine patients, 16 with RA and 13 with other inflammatory joint diseases, were investigated and compared to PBMC from 25 healthy controls. The mean number of IFN-gamma-producing cells was 37.1/10(5) plated SFMC (range 0-121.5). The corresponding value for PBMC was 5.1 (0-39). The difference was highly significant (P = 0.0033 for RA patients, P = 0.0050 for non-RA patients and P < 0.0001 for all patients). Forty-five per cent of SFMC samples (range for all samples 0-38.5 SFC/10(5) MNC) and 25% of PBMC samples (0-20.5) exhibited spontaneous IL-4 production, yielding a significant difference for all patients treated collectively (P = 0.021). Although the cells that spontaneously secrete these cytokines are relatively few, quantification of these cells thus shows increased functional T-cell activation and decreased ratio of cells spontaneously producing IL-4 vs IFN-gamma in the joint fluid as compared to blood of arthritis patients.

Adult↗
PubMed1996

Quantification of morphometric changes in murine experimental osteoarthritis using image analysis.

The aim of this study was to evaluate a method for the quantification of cartilage erosions and osteophyte sizes in a murine model of osteoarthritis (OA). Mice in which OA was induced in the knee joint by intra-articular injection of bacterial collagenase were used. With an interactive image analysis system, the areas occupied by osteophytes and the areas of erosions of the articular cartilage were measured on histological sections by two independent observers at two time points. Measurements of osteophyte areas and cartilage loss at the tibial plateau showed good reproducibility, whereas measurement of cartilage loss at the femoral condyles was less reproducible. Measurement of three frontal total knee joint sections from the middle part of the joint provided a reliable measure for cartilage damage and osteophyte size in the total joint. A cumulative score was developed, composed of both cartilage loss and osteophyte size, which can be used as a general measure for OA of the knee joint. The presented method of quantitative scoring makes it possible to perform correlation studies and to investigate the effect of therapeutic interventions on the osteoarthritis process.

Animals↗
PubMed1987

Screening of degradative enzymes from articular cartilage in experimental osteoarthritis.

Sixteen rabbits were killed 12 weeks after sectioning of the right knee anterior cruciate ligament. The left unoperated knee served as a control. The surface area of fibrillated cartilage from femoral condyles and tibial plateau was evaluated and expressed as a percentage of articular surfaces area. Cartilage from the femoro-patellar surfaces was homogenized for the quantification of several degradative activities, based on the release of digested products. Acid phosphatase, several glycosidases and neutral protease activity from the operated joint cartilage were significantly elevated, while collagenolytic activity was unmodified. The percentage of fibrillated cartilage correlated positively with arylsulfatase, glucosidase and neutral protease but negatively with mannosidase and fucosidase. The results may be consistent with the hypothesis of a sequential degradative process leading to cartilage destruction.

Animals↗
PubMed2002

Quantification of T-cell receptor excision circle DNA using fluorescence resonance energy transfer and the LightCycler system.

T-cell receptor excision circles (TRECs) are circular, stable extrachromosomal DNA fragments and are generated during V(D)J gene recombination, a process responsible for diversity of the T-cell receptor repertoire. Here we describe a sensitive, rapid and easy to perform real-time PCR assay based on the LightCycler technique for the quantification of TRECs among peripheral blood cells and a comparison of this assay with conventional PCR-ELISA. By LightCycler, a sensitivity of 20 copies of plasmid deltaRec-psiJalpha Signal Joint TREC DNA was achieved whereas by PCR-ELISA, a detection limit of 2 copies was demonstrated. In blood samples from healthy individuals (n=52) a median TREC count of 1.6x10(4) copies [range 2x10(1) to 2x10(5)]/2x10(5) peripheral blood mononuclear cells (PBMNCs) and in cord blood, a median TREC count of 1.45x10(5) copies [range 1.2x10(5) to 1.6x10(5)]/2x10(5) PBMNCs) could be detected. No significant difference was found in 15 individuals when unfractionated PBMNCs (median count of 1.1x10(5) copies/2x10(5) PBMNCs) or magnetic associated cell sorter (MACS)-sorted CD45RA+ T-cells (median count of 2.5x10(5) copies/2x10(5) cells) were analyzed for TREC counts. In addition, we examined the number of deltaRec-psiJalpha Signal Joint TREC in paediatric (n=6) and adult patients (n=7) after allogeneic stem cell transplantation. In children, we observed a median TREC count of 5.7x10(4) copies/2x10(5) PBMNCs after 1x10(4) and 5.6x10(4) copies/2x10(5) PBMNCs after 2 years, and in adults, a median count of 3.6x10(4) copies/2x10(5) PBMNCs after 1x10(4) and 1.1x10(4) copies/2x10(5) PBMNCs after 2 years. In conclusion, the LightCycler-based real-time PCR assay described offers a very sensitive and rapid tool for the quantification of TREC DNA.

Adolescent↗
PubMed2003

Variability of RANKL and osteoprotegerin staining in synovial tissue from patients with active rheumatoid arthritis: quantification using color video image analysis.

OBJECTIVE: To assess the interpatient, interbiopsy, and intrabiopsy variability of receptor activator of nuclear factor kB ligand (RANKL) and osteoprotegerin (OPG) immunostaining within synovial tissue from rheumatoid knee joints with active synovitis, using digital image analysis. METHODS: Synovial biopsy specimens were obtained from patients with rheumatoid arthritis (RA) and active synovitis. Immunohistologic analysis was performed on frozen synovial tissue biopsy specimens from 6 patients using a monoclonal antibody (Mab) to detect RANKL (626) or OPG (805 or 8051). Patients with a minimum of 4 synovial biopsies were included in the study. Sections were evaluated by computer assisted image analysis to assess between-patient, between-biopsy, and intra-biopsy variability of OPG and RANKL protein expression. The study was designed to deliberately maximize the variability. RESULTS: Computerized image analysis of staining with Mab to RANKL and OPG revealed variance for each antibody across the 3 components of the total variability. CONCLUSION: Our study shows that variability in synovial immunostaining of RANKL and OPG protein is a significant and complex problem. We discuss methods to reduce this variability and suggest that the auspices of OMERACT may be employed to advance the study of synovium in collaborative international studies.

Aged↗
PubMed2002

Quantification of newly developed T cells in mice by real-time quantitative PCR of T-cell receptor rearrangement excision circles.

OBJECTIVE: Thymic output of newly developed ab T cells in humans can be measured via signal joint T-cell receptor rearrangement excision circles (sjTRECs). Deletion of the TCRD locus via dRec to psiJa recombination during TCRA rearrangement results in the production of such sjTRECs. The deleting elements dRec and psiJa are highly conserved between humans and mice and used in a comparable manner. We developed and evaluated a real-time quantitative PCR (RQ-PCR) to detect and quantify dRec-psiJa sjTRECs in murine peripheral blood leukocytes for estimation of thymic output of newly developed ab T cells in mice. METHODS: The threshold cycle (Ct) of the sjTREC RQ-PCR was related to the Ct value of an endogenous reference gene. The difference in Ct value (DCt) was correlated to the absolute numbers of CD45+ and CD3+ cells per mL of blood, as obtained by a single platform flow cytometric assay, resulting in the frequency of sjTRECs in CD45+ and CD3+ cells. RESULTS: The RQ-PCR proved to be sensitive with a detection level of approximately one sjTREC copy in 100 ng of DNA. SjTRECs could not be detected in peripheral blood leukocytes of RAG-1(-/-) mice, demonstrating the specificity of the assay. As in humans and primates, sjTREC levels declined in aging and thymectomized mice. Remarkably, significant mouse strain-dependent differences in sjTREC levels were observed. 129Sv and C57BL/6 mice had significantly lower sjTREC levels in blood than Balb/c and DBA2 mice. CONCLUSION: Quantification of murine sjTRECs by RQ-PCR may allow for accurate assessment of thymic output in mice.

Aging↗
PubMed2005

Tracking the sources of nitrate in groundwater using coupled nitrogen and boron isotopes: a synthesis.

Nitrate (NO3) is one of the world's major pollutants of drinking water resources. Although recent European Directives have reduced input from intensive agriculture, NO3 levels in groundwater are approaching the drinking water limit of 50 mg L(-1) almost everywhere. Determining the sources of groundwater contamination is an important first step toward improving its quality by emission control. It is with this aim that we review here the benefit of using a coupled isotopic approach (delta15N and delta11B), in addition to conventional hydrogeological analyses, to trace the origin of NO3 in water. The studied watersheds include both fractured bedrock and alluvial (subsurface and deep) hydrogeological contexts. The joint use of nitrogen and boron isotope systematics in each context deciphers the origin of NO3 in the groundwater and allows a semi-quantification of the contributions of the respective pollution sources (mineral fertilizers, wastewater, and animal manure).

Agriculture↗
PubMed1994

The use of surface EMG in knee extensor moment prediction.

A systematic method of EMG quantification is developed to estimate the isometric muscle moment directly from quantified surface EMG. This method includes the EMG Signals acquired from an acupuncture point Fu-Tu located on the quadriceps muscle group, an EMG smoothing scheme, an electromechanical time lag estimation, and a mathematical model with the polynomial regression function to quantify the EMG. Three subjects were asked to be tested on the CYBEX II dynamometer with a knee joint angle of 90 degree flexion and hip joint angle of also 90 degrees. They were asked to perform "two" trials of maximal voluntary contraction and "three" trials of free voluntary contraction of the isometric exercise. The first two trials were used to build up the quantification model, and the latter three trials served as data for the validation of the method. A Medelec MS92 EMG system with surface EMG electrodes was used to acquire the EMG Signals. In the determination of the regression order of the polynomial equations, the threshold value 0.0001 of the difference of the coefficient of determination values was used. The results of the polynomial regression orders are all 6 for three subjects, which reflects a tendency of nonlinear behavior of the EMG/moment relationship. A validation scheme was proposed to calculate the root mean square difference (RMSD) of the measured knee extensor moments from the CYBEX II dynamometer and estimated moments from the EMG quantification. The mean values of the RMSD of the three subjects were 0.0597, 0.0679 and 0.1080. These results demonstrate that the present approach can estimate the isometric muscle moment exerted by the quadriceps muscle group.

Acupuncture Points↗
PubMed2003

Quantitative assessment of pterygomasseteric hypertrophy.

The aim of this study was to quantify the pterygomasseteric hypertrophy in a clinical case with significant facial asymmetry and temporomandibular joint dysfunction. Magnetic resonance imaging (MRI) technique was used to measure the surface areas of affected and contralateral pterygomasseteric muscle groups on six coronal scans. The results suggest that MRI is a very effective method for quantification of muscular hypertrophy and better explanation of associated clinical findings, therefore motivating the need to preserve or restore the bilateral masticatory function.

Adult↗
PubMed2004

Three-dimensional kinematic analysis of horses with induced tarsal synovitis.

REASONS FOR PERFORMING STUDY: Techniques for 3D analysis have recently been developed. This study applied 3D kinematic analysis to describe the effects of lameness in the distal intertarsal (DIT) and tarsometatarsal (TMT) joints; complex joints such as this may show measurable amounts of movement outside the sagittal plane that may change in response to pathological conditions. HYPOTHESIS: Three-dimensional motions of the tarsal joint change after the induction of synovitis at the DIT and TMT joints. METHODS: Twelve retroreflective markers, attached on the skin over the right limb, were used to develop 3D coordinate systems for tibial and metatarsal segments. Data were collected at trot from 4 horses on 2 occasions, before (sound condition) and after (lame condition) induction of synovitis of the DIT and TMT joints. Ranges of 3D motions of the metatarsal segment relative to the tibial segment were compared between sound and lame conditions using t tests. RESULTS: There were significant decreases (P<0.05) in tarsal joint flexion and cranial translation of the metatarsus relative to the tibia during stance, and in proximal translation of the metatarsus during swing. CONCLUSIONS AND POTENTIAL RELEVANCE: In the lame condition, reduced cranial translation at the DIT and TMT joints may lead to a reduction in the motion of the articular cartilage surfaces relative to each other, which may have adverse effects on cartilage nutrition and function. Further studies of tarsal 3D kinematics in horses with bone spavin could allow quantification of the biomechanical effects of the special shoes used for conservative treatment.

Animals↗
PubMed2006

An upper extremity kinematic model for evaluation of hemiparetic stroke.

Quantification of rehabilitation progress is necessary for accurately assessing clinical treatments. A three-dimension (3D) upper extremity (UE) kinematic model was developed to obtain joint angles of the trunk, shoulder and elbow using a Vicon motion analysis system. Strict evaluation confirmed the system's accuracy and precision. As an example of application, the model was used to evaluate the upper extremity movement of eight hemiparetic stroke patients with spasticity, while completing a set of reaching tasks. Main outcome measures include kinematic variables of movement time, range of motion, peak angular velocity, and percentage of reach where peak velocity occurs. The model computed motion patterns in the affected and unaffected arms. The unaffected arm showed a larger range of motion and higher angular velocity than the affected arm. Frequency analysis (power spectrum) demonstrated lower frequency content for elbow angle and angular velocity in the affected limb when compared to the unaffected limb. The model can accurately quantify UE arm motion, which may aid in the assessment and planning of stroke rehabilitation, and help to shorten recovery time.

Adult↗
PubMed2006

Chondrocyte death by apoptosis is associated with cartilage matrix degradation.

OBJECTIVES: To investigate the frequency of chondrocyte apoptosis in equine articular cartilage (AC) specimens and to examine the relationship between the process of cell death and the degree of cartilage degradation using a direct quantification of numbers of apoptotic cells and expression of active caspase-3. METHODS: AC from equine metacarpophalangeal (MCP), proximal interphalangeal (PIP) and distal interphalangeal (DIP) joints was used and each joint was graded macroscopically for cartilage degradation (macroscopic osteoarthritis (OA) score). Cartilage sections were graded using a 'modified' Mankin scoring system. Apoptosis of chondrocytes in cartilage sections was assessed morphologically by appearance of apoptotic features (direct method) and by expression of active caspase-3 using indirect immunohistochemistry. RESULTS: The extent of apoptosis assessed by the direct method did not show any relationship with increasing severity of OA (P=0.72). However, there was a significant positive correlation between 'modified' Mankin score and apoptosis determined by caspase-3, with the extent of apoptosis found to increase linearly with increasing severity of OA (r=0.44, P=0.0043). Caspase-3 expression was found to be significantly higher in the superficial and middle zones than in the deep zone (P<0.001). In the superficial, middle and deep zones, expression of caspase-3 was significantly higher in the MCP joint than in the PIP joint (P=0.013, P=0.0018 and P=0.029, respectively). Within the MCP joints, apoptosis was higher in the lateral compartment compared to the medial (P=0.053). CONCLUSIONS: The data presented in this study demonstrate that chondrocyte apoptosis is positively associated with degree of cartilage matrix damage and that the extent of apoptosis varies with cartilage zones and mechanical loading environment of the joint.

Animals↗
PubMed1992

Analysis of knee vibration signals using linear prediction.

Clinical methods used at present for the diagnosis of cartilage pathology in the knee are invasive in nature, and carry some risks. There exists a need for the development of a safe, objective, noninvasive method for early detection, localization, and quantification of cartilage pathology in the knee. This paper investigates the possibility of developing such a method based on an analysis of vibrations produced by joint surfaces rubbing against one another during normal movement. In particular, the method of modeling by linear prediction is used for adaptive segmentation and parameterization of knee vibration signals. Dominant poles are extracted from the model system function for each segment based on their energy contributions and bandwidths. These dominant poles represent the dominant features of the signal segments in the spectral domain. Two-dimensional feature vectors are then constructed using the first dominant pole and the ratio of power in the 40-120 Hz band to the total power of the segment. The potential use of this method to distinguish between vibrations produced by normal volunteers and patients known to have cartilage pathology (chondromalacia) is discussed.

Auscultation↗
PubMed1998

Quantification of in vivo patellofemoral contact forces before and after ACL transection.

Altered knee loading following anterior cruciate ligament (ACL) transection is believed to play an important role in initiating cartilage degeneration. Changes of in vivo joint contact forces pre- and post-ACL transection have not been quantified to date. Consequently, it is not known how knee loading changes following ACL transection, and how it contributes to cartilage degeneration. The objective of this study was to quantify in vivo patellofemoral contact forces in the cat knee prior to and up to nine days following uni-lateral ACL transection. Patellofemoral contact forces were predicted using a planar three-force model with knee extensor forces and patellofemoral geometry as input. Patellofemoral movements were expressed as functions of external knee kinematics. Kinematics and knee extensor forces were measured in both hindlimbs before and after ACL transection during unrestrained locomotion. Following ACL transection, resultant patellofemoral contact forces were decreased by approximately 30% in the ACL-deficient hindlimbs. These results suggest that decreased loading in the ACL-deficient knees may initiate the early degenerative changes observed in cartilage of ACL-transected animals. It remains to be shown, if the general unloading of the joint also results in locally decreased contact loads and altered joint kinematics. Alterations of in vivo patellofemoral loading following ACL transection have been quantified for the first time in this study. A next step will be to quantify the dynamic in vivo cartilage stresses in intact and injured knees which may help to elucidate the effects of mechanical stimuli on cartilage metabolism.

Animals↗