Percutaneous drainage of fluid collections in the extremities

PURPOSE

To analyze the results of percutaneous drainage of fluid collections in the extremities.

MATERIALS AND METHODS

From 1990-1997, 28 patients aged 14-90 years underwent percutaneous drainage of 33 fluid collections in the extremities; two patients underwent multiple drainages. Fluid collections were in the hip-groin area (n = 16), thighs (n = 6), buttocks (n = 6), knees (n = 3), calf (n = 1), and axilla (n = 1). Three intraarticular collections were included. The patients who had undergone prior procedures were eight who had undergone surgical drainage, 10 who had undergone needle aspiration, and one who had undergone surgical débridement. The two most common guidance methods of catheter placement were ultrasound localization and fluoroscopy.

RESULTS

The average drainage duration was 18.2 days (range, 1-93 days). The estimated cavity sizes were 4-733 cm3. Purulent fluid was drained in 13 patients. Staphylococcus aureus was the most commonly identified organism (n = 9). Nine patients had postoperative lymphoceles; five of these patients underwent sclerotherapy. Two (7%) patients had two complications, one of which was major. Failure occurred in four (16%) of 25 patients; two needed repeat drainage for recurrence, and two needed subsequent surgery. Success could not be determined in three patients who were lost to follow-up.

CONCLUSION

Percutaneous drainage of fluid collections in the extremities is an effective alternative to open-incision drainage in inpatients and outpatients.

[MRI and articular cartilage]

Although plain films are fundamental for routine imaging of degenerative chondral lesions, MRI is a promising tool of investigation for the articular cartilage. Its modalities are still imprecise and debated, but, because of its noninvasiveness, it is destined to be preferred over arthroCT. The small size of the cartilage requires thin slices of less than 3-mm thick. The various features of normal cartilage images must be well known. They depend on acquisition parameters, zonal structure of the cartilage and numerous artifacts (partial volume average, chemical shift, magnetic susceptibility, truncation, "magic angle"). Fast SE images provide a good compromise between contrast and the signal-to-noise ratio. T2-weighted images take advantage of an arthrographic effect in case of joint effusion. 3D GE images allow a more accurate evaluation with 1-mm thick slices. In all sequences, adding of a fat-suppression presaturation increases contrast between the cartilage and the surrounding structures. The diagnostic accuracies of the different sequences and of MR arthrography are discussed. Quantitative measurements of cartilage thickness and volume remain the topic of clinical research.

Osteomyelitis of the pelvis/hips in paralyzed patients: accuracy and clinical utility of MRI

PURPOSE

The goal of our study was to determine the accuracy and clinical utility of MRI in the diagnosis of osteomyelitis of the pelvis/hips in paralyzed patients.

METHOD

In 44 paralyzed patients, 59 consecutive MR examinations of the pelvis/hips were evaluated prospectively. Criteria for diagnosis of osteomyelitis were based on those established in previous studies of complex, nonhematogenous osteomyelitis (diabetic foot). Average follow-up was 3 years. The standard of reference for the diagnosis of osteomyelitis was histologic/microbiologic results of surgical biopsy specimens or clinical follow-up. Note was made if decubitus ulcers, sinus tract, fistula, fluid collection, abscess, septic arthritis, joint effusion, bursitis, or heterotopic ossification was present on MRI. Comparison of the extent of infection by MRI and surgical margins was performed. Effect on surgical treatment was defined by absence of recurrent infection at the surgical site within 6 weeks of limited resection.

RESULTS

The criteria for diagnosis of osteomyelitis were fulfilled in 49 of 57 MR studies for an overall accuracy of 97%. There was one false-negative MR study. MRI for the diagnosis of osteomyelitis yielded a sensitivity of 98% and a specificity of 89%. There were 41 decubitus ulcers, 28 sinus tracts, 2 fistulae, 14 fluid collections, 15 abscesses, 9 hips with septic arthritis, 10 "bland" hip effusions, 5 cases of trochanteric bursitis, and 30 patients with heterotopic ossification. Twenty-one patients underwent limited surgical resection guided by MR findings in which only the enhancing area was resected. There was only one recurrence of osteomyelitis at the surgical margins.

CONCLUSION

MRI is accurate in the diagnosis of osteomyelitis and associated soft tissue abnormalities in spinal cord-injured patients. MRI can delineate the extent of infection in guiding limited surgical resection and preserving viable tissue.

Synovial effusion in reflex sympathetic dystrophy: an additional sign for diagnosis and staging

PURPOSE

To improve the present MRI criteria for diagnosis and staging of reflex sympathetic dystrophy (RSD) by including increased joint fluid as an additional MRI sign of RSD.

DESIGN AND PATIENTS

One hundred and fourteen extremities (69 affected and 45 contralateral controls) in 57 consecutive patients with RSD were evaluated using a 1.5-T unit. T1- and T2-weighted pulse sequences, often with fat suppression, were used before and after administration of intravenous contrast enhancement (Gd). Following T2-weighted image digitization the volume of synovial fluid was measured with a computer model.

RESULTS

Effusions were detected in 61% of the extremities suspected of RSD and in 44% of the contralateral control joints. The mean fluid quantity measured in the symptomatic articulation was 201 mm3. MRI diagnosis of RSD based on previously described criteria was done in 62% of the patients, yielding a sensitivity of 60%. Effusions were present in 79% of the false negative MRI cases. Retrospectively considering the presence of fluid as a potential positive criterion for RSD increases the sensitivity by 31% (to 91%).

CONCLUSIONS

Joint effusions are probably associated with early stages of RSD. Adding effusion to the list of radiological criteria for RSD increases the sensitivity of MRI from 60% to 91%.

Anterolateral impingement of the ankle: effectiveness of MR imaging

PURPOSE

To determine the effectiveness of magnetic resonance (MR) imaging in the diagnosis of anterolateral impingement of the ankle.

MATERIALS AND METHODS

MR images were reviewed in 12 patients (12 ankles) with arthroscopically proved anterolateral impingement and in 19 control subjects (20 ankles) with diagnoses other than impingement. MR images were scored by means of consensus of two musculoskeletal radiologists and independently by a third radiologist. Patients underwent imaging at 1.5 T, with use of standard imaging sequences and a dedicated extremity coil.

RESULTS

For the consensus reading, the sensitivity, specificity, and accuracy of MR imaging for the diagnosis of impingement were 42%, 85%, and 69%, respectively. The frequency of lateral gutter fullness and anterior talofibular ligament thickening on MR images was higher in the 12 ankles with impingement (seven [58%] and seven [58%] ankles, respectively) than in the 20 control ankles (seven [35%] and five [25%] ankles, respectively), but these trends did not reach statistical significance. Interobserver agreement for anterior talofibular ligament thickening was high, whereas that for lateral gutter fullness was fair.

CONCLUSION

Conventional MR imaging of the ankle is insensitive for anterolateral impingement. Anterior talofibular ligament thickening and soft-tissue fullness in the lateral gutter may be suggestive of the diagnosis, but the reliability of the latter finding is questionable.

MR imaging of the normal and abnormal retrocalcaneal bursae

OBJECTIVE

The aim of this study was to define the MR imaging criteria for normal and abnormal retrocalcaneal bursae.

SUBJECTS AND METHODS

Fifty ankles in 25 asymptomatic volunteers and 30 ankles in patients with Achilles tendon disorders underwent MR imaging. Increased signal intensity consistent with fluid or synovium outlining the retrocalcaneal bursa was measured.

RESULTS

Of 80 bursae, 77 (96%) had measurable fluid or synovial signal intensity revealed by MR imaging. Asymptomatic volunteers had average bursal dimensions of 1 mm in the anteroposterior dimension, 6 mm in the transverse dimension, and 3 mm in the craniocaudal dimension. Bursal dimensions greater than 1 mm, 11 mm, or 7 mm, respectively, were not seen in asymptomatic subjects but were seen in 16 (53%) of 30 ankles of patients with Achilles tendon disorders.

CONCLUSION

On MR imaging, the asymptomatic retrocalcaneal bursa normally contains detectable high-signal-intensity fluid or synovium or both. A bursa larger than 1 mm anteroposteriorly, 11 mm transversely, or 7 mm craniocaudally is abnormal.

MRI evaluation of the inferior glenohumeral ligament. Comparison with arthroscopic findings in 81 shoulders

Arthroscopic Bankart repair, using staples, requires a thick and wide anterior band of the inferior glenohumeral ligament. We compared MRI and arthroscopic findings of the ligament in 81 shoulders with traumatic anterior glenohumeral instability. When fluid was present in the shoulder, sensitivity and specificity of the MRI evaluation for the presence of a thick and wide ligament were 82% and 100%, respectively. In shoulders without joint fluid, the condition of the ligament was evaluated according to the presence of a low- or moderate-signal triangle structure on the anterior margin of the glenoid cavity in the 3 MR images obtained from the inferior 2 cm of the glenoid. Sensitivity and specificity of the MRI evaluation in cases without fluid were 84% and 93%, respectively. The MR technique needs to be further improved to achieve better sensitivity for preoperative selection of shoulders suitable for Bankart repair with staples.

Friction of composite cushion bearings for total knee joint replacements under adverse lubrication conditions

Conventional joint replacements consist of a polished metallic or ceramic component articulating against a layer of polyethylene. Although the friction in the contact between these articulating surfaces is low, polyethylene wear is produced as a result of a boundary/mixed lubrication regime. Wear debris is generated by direct asperity contact, abrasion, adhesion and fatigue, and has been shown to cause adverse tissue reactions which can lead to joint failure. The introduction of soft compliant materials, similar in stiffness to articular cartilage, has shown that with cyclic loading and relative motion between the articulating surfaces typical of normal walking, a fluid film can be maintained through combined entraining and squeeze-film actions, and hence wear can be minimized. For 95 per cent of the time, however, we are not walking but standing still or moving slowly. A pendulum simulator has been used in the present study to investigate the effect of adverse tribological conditions which may lead to fluid film breakdown, such as severe cyclic loading, particularly in the swing phase, reduced sliding velocity, reduced stroke length and start-up after a period of constant loading. Friction of a model composite cushion knee bearing, manufactured from a graded modulus (20-1000 MPa) layer of polyurethane, sliding against a polished metal cylinder has been measured for various lubricants and the results have been analysed using a Stribeck assessment. Severe cyclic loading, decreased sliding velocity and decreased stroke length have been found to limit the degree of fluid entrainment previously allowed during the swing phase of normal walking, thus allowing breakdown of fluid films and elevated levels of friction and surface damage. Soft layer joint replacements must therefore be designed to operate with thick elastohydrodynamic fluid films to provide some degree of protection when tribological conditions become severe, or alternatively incorporate alternative boundary or mixed lubrication mechanisms. This study quantifies a potential limitation of the cushion bearing concept.

Proteoglycan's activation by adhesion molecules and L metalloproteases in rheumatoid arthritis and osteoarthritis

Two groups of patients were studied, both in accordance with ACR criteria. First group (41 cases) suffering R.A. Second group (36 cases) suffering O.A. In both pathologies MMPs, ICAM and VCAM from synovial fluid and plasma were studied. Measurements were made with ELISA-sandwich in a Metrolab spectrophotometer at 410 nm for MMPs, and 491 nm for ICAM and VCAM. As control, samples of patients with noninflammatory muscle skeletal disorders or traumatic arthritis and healthy witness were used. Synovial concentration of MMPs in R.A. was 1402 +/- 76 ng/ml, a higher significant value (p < 0.0001) compared with osteoarthritis: 353 +/- 23 ng/ml. In the witness plasma, MMPs were not detected. Plasmatic and synovial levels of the adhesion molecules present different values in both pathologies and between them. Synovial ICAM level in R.A. (280 +/- 9.8 ng/ml) is significantly higher than in O.A. (163 +/- 10 ng/ml) (p < 0.001), but lower than the plasmatic ones (370 +/- 35 ng/ml) (p < 0.001). All these values are significantly higher than the normal plasma (121 +/- 6.5 ng/ml) (p < 0.01, p < 0.005, and p < 0.0001, respectively) VCAM increase regarding basal values (140 +/- 5.6 ng/ml) (p < 0.001) and in a similar proportion for both pathologies (R.A.: 186 +/- 9.3 ng/ml and O.A.: 207 +/- 14.3 ng/ml). Their plasmatic levels were higher (270 +/- 45 and 320 +/- 38 ng/ml) (p < 0.001) but without significative difference between them. There is correlation among MMPs, ICAM and VCAM variations. The variability can be explained by concomitance several evolutive steps. Each pathology shows a different grade of cellularity, inverted predominance in the relation TIMPs/ collagenase and different generator mechanisms of MMPs. Our findings reinforce the importance as diagnostic guide of adhesion molecules dosage, and possible therapeutic use of MMPs inhibitors and ICAM or VCAM antagonists en R.A. and related pathologies.

Effusion in magnetic resonance imaging of the temporomandibular joint: a study of 123 joints

PURPOSE

Effusion is the term used by radiologists for a hyperintensity signal seen inside a joint on magnetic resonance imaging (MRI). The aim of this study was to correlate the clinical and imaging features of this phenomenon, with the ultimate purpose of clarifying its meaning in dysfunctional processes of the temporomandibular joint (TMJ).

PATIENTS AND METHODS

The clinical histories of 111 patients (123 joints) with effusion on MRI were reviewed. Thirty-one patients (46 joints) with articular pathology but without effusion, chosen at randomized, served as a control group. Five clinical variables (articular pain, radiating pain, limited mouth opening, clicking, and clinical stage) and five imaging findings (disc displacement, effusion location, disc morphology, osteophytes, avascular necrosis, and osteochondritis dissecans) were evaluated.

RESULTS

Effusion in TMJ could be seen in relation to disc displacement and degenerative changes (osteophytes, avascular necrosis, osteochondritis dissecans). Clicking was more frequently found in TMJs without effusion.

CONCLUSIONS

These results suggest that effusion may be a marker of articular degeneration in the TMJ.

Polyarticular pigmented villonodular synovitis in a child

Pigmented villonodular synovitis is rare in the younger child. Polyarticular involvement in this condition, regardless of patient age, is distinctly uncommon. The authors describe a case of pigmented villonodular synovitis involving multiple joints in a young boy who also had congenital anomalies of the genitourinary tract. Although rare, pigmented villonodular synovitis should be considered in the differential diagnosis of multiple joint swellings in children with congenital anomalies.

A review of the role of magnetic resonance imaging in the evaluation of shoulder impingement syndrome and rotator cuff tendon tears

The objective of this paper is to present a review of the role of magnetic resonance imaging in the evaluation of shoulder impingement syndrome and rotator cuff tendon tears. This imaging modality is effective in demonstrating both the soft tissue and bony abnormalities associated with structural shoulder impingement which include subacromial-subdeltoid bursitis, supraspinatus tendinopathy, rotator cuff tendon tears, subacromial osteophytic spurs and acromioclavicular joint capsular hypertrophy and osteophytosis. The detection of a subacromial osteophytic spur is considered specific for shoulder impingement syndrome. The 3 most accurate magnetic resonance imaging signs of a full thickness supraspinatus tendon tear reported are: tendon discontinuity, musculotendinous junction retraction and supraspinatus tendon thinning. The most specific sign is tendon discontinuity and the most sensitive is subacromial-subdeltoid bursal fluid.

Low-field magnetic resonance imaging of the canine stifle joint: normal anatomy

Low-field magnetic resonance imaging (MRI) was performed on the stifle joints of four normal adult mongrel dogs using a 0.064 Tesla scanner. Markers were placed on each stifle joint to serve as reference points for comparing gross sections with the images. A T1-weighted sequence was used to image one stifle joint on each dog in the sagittal plane and the other stifle joint in the dorsal plane. The dogs were euthanized immediately following MRI and the stifle joints frozen intact. Each stifle joint was then embedded in paraffin, again frozen, and sectioned using the markers as reference points. On T1-weighted images, synovial fluid had low signal intensity (dark) compared to the infrapatellar fat pad which had a high signal intensity (bright). Articular cartilage was visualized as an intermediate bright signal and was separated from trabecular bone by a dark line representing subchondral bone. Menisci, fibrous joint capsule, and ligamentous structures appeared dark. In the true sagittal plane, the entire caudal cruciate ligament was often seen within one image slice. The patella was visualized as an intermediate bright signal (trabecular bone) surrounded by a low intensity signal (cortical bone). The trochlea and the intercondylar notch were difficult areas to analyze due to signal volume averaging of the curved surface of these areas and the presence of several types of tissues.

Evidence of ED-B+ fibronectin synthesis in human tissues by non-radioactive RNA in situ hybridization. Investigations on carcinoma (oral squamous cell and breast carcinoma), chronic inflammation (rheumatoid synovitis) and fibromatosis (Morbus Dupuytren)

The splicing variant of fibronectin containing the ED-B domain (oncofoetal fibronectin) occurs in foetal tissues, reparative processes, organ fibrosis and in tumour tissues. Consequently, a supportive effect of ED-B+ fibronectin for tissue remodelling and tumour progression is assumed. A non-radioactive RNA-RNA in situ hybridization protocol for the investigation of ED-B+ fibronectin synthesis applicable in human tissues is introduced. The ED-B+ fibronectin synthesis was investigated in human disease processes, for which the occurrence of ED-B+ fibronectin is well demonstrated by immunohistochemistry (rheumatoid arthritis, oral squamous cell carcinoma, invasive ductal carcinoma of the breast and nodular palmar fibromatosis). The ED-B+ fibronectin synthesis could be shown in lining cells and in endothelial cells of synovial villi in rheumatoid arthritis, in stromal cells of oral squamous cell carcinoma and invasive ductal carcinoma and in fibro-/myofibroblasts in the proliferative and early involutional phase of nodular palmar fibromatosis. By means of double labelling (alpha-smooth muscle actin immunostaining - ED-B+ fibronectin in situ hybridization), the ED-B+ fibronectin synthesis could be shown to be a typical feature of myofibroblasts. In contrast to the often diffuse ED-B+ fibronectin immunostaining, only a few synthetically active stromal cells were observed focally accentuated within the tumour, which were interpreted as hot spots of tumour-stroma interaction.

Joint and soft-tissue injection. A useful adjuvant to systemic and local treatment

Joint and soft-tissue injection can augment systemic and local conservative treatment and have long-lasting benefits. Inflammatory and crystalline arthritis, synovitis, tendinitis, bursitis, and many other conditions respond well to injection. Corticosteroid preparations should be chosen on the basis of solubility and potency desired and the size of structure to be injected. Injections should not be made directly into a ligament or tendon and should be limited to every third or fourth month. With attention to the usual cautions required with corticosteroid use and avoidance of contraindications (e.g., bacteremia, fracture), injection is usually safe and effective, particularly as a bridging technique to long-term therapy.

Arthrographic effect induced by therapeutic ultrasound in magnetic resonance imaging of the wrist: a preliminary investigation

OBJECTIVE

To evaluate the potential arthrographic effect of therapeutic ultrasound applied before magnetic resonance imaging (MRI) of the wrist.

SUBJECTS AND METHODS

MRI of the wrist was performed in 6 asymptomatic volunteers before and after ultrasound therapy of the carpus. For each patient, ultrasound therapy was performed by a trained physiotherapist for 10 minutes, with doses titrated to the maximum tolerated without pain. The amount of fluid within the wrist joints before and after therapy was assessed subjectively by 2 reviewers, as well as objectively by digital analysis.

RESULTS

Subjective appraisal of the images indicated that after ultrasound therapy there was an increase in joint fluid within the distal radioulnar joint in 4 volunteers, the midcarpal joint in 4 and the radiocarpal joint in 2. Computerized digital analysis of joint fluid confirmed an average volumetric increase in wrist joint fluid of 52.8% in 3 of the volunteers. The discomfort of the therapy was graded as 1/10 by 5 of the subjects and 4/10 by a single subject.

CONCLUSIONS

Therapeutic ultrasound may be a useful adjuvant tool in the noninvasive induction of joint fluid before MRI of the wrist.

Recurrent synovial chondromatosis treated with meniscectomy and synovectomy

Synovial chondromatosis is a rare benign intraarticular metaplasia of synovium. This process may result in the production of detached particles of highly cellular cartilage in the involved joint spaces. It is most often reported in the larger joints of the body including the knee, hip, elbow, and ankle. Since Axhausen in 1993 reported the first case affecting the temporomandibular joint, several articles have been listed in the literature regarding the presentation, diagnosis, and management of this form of an arthropathy. This is a case of a recurrent synovial chondromatosis that was approached with a meniscectomy and a complete synovectomy.

Modified technique for fluid aspiration from the hip in patients with prosthetic hips

A modified technique was used for diagnostic aspiration of fluid from the hip in 185 patients who had previously undergone total hip arthroplasty. The aspiration needle was advanced past the lateral aspect of the shaft of the prosthesis and into the dependent portion of the joint. Fluid was successfully aspirated in 181 of 185 patients; thus the dry-tap rate was 2.2% (four of 185 patients). The modified technique was simple, could be performed quickly, and was effective for sampling joint fluid in patients with hip prostheses.

Synovial fluid cavitation during distraction radiography of the coxofemoral joint in dogs

OBJECTIVE

To determine risk factors for, and prevalence and short- and long-term effects of synovial fluid cavitation during distraction radiography.

DESIGN

Multicenter prevalence survey.

ANIMALS

6,649 purebred dogs comprising 129 breeds.

PROCEDURE

Radiographs from the PennHIP (University of Pennsylvania Hip Improvement Program) Laboratory were subjectively evaluated for evidence of cavitation. Multiple logistic regression was used to determine whether sex, breed, age, weight, distraction index (DI), or examining veterinarian was associated with cavitation. Short-term effects of cavitation were assessed by comparing DI for the hip with cavitation with DI for the contralateral hip in dogs with unilateral cavitation. Long-term effects of cavitation were assessed by comparing DI before and after cavitation was detected.

RESULTS

Cavitation was detected in 279 (4.2%) of the radiographs analyzed. Male dogs, Golden Retrievers, and heavier dogs were at a decreased risk for cavitation. Irish Wolfhounds, Irish Setters, Rhodesian Ridgebacks, and Weimaraners had an increased risk for cavitation. Age and DI were not risk factors for cavitation. Mean DI was 0.08 greater in hips with cavitation than in paired hips without cavitation. Significant differences were not detected between DI before and after cavitation, but only 7 dogs were included in this analysis.

CLINICAL IMPLICATIONS

Cavitation is rare during distraction radiography and can increase measured DI. Radiographs should be routinely examined to ensure accurate reporting of DI.

Magnetic resonance imaging of the equine metacarpophalangeal joint: three-dimensional reconstruction and anatomic analysis

Magnetic resonance imaging was used to examine the equine metacarpophalangeal joint. Thirty-two saggital images generated by partial volume imaging were transferred to a computer for three-dimensional reconstruction and analysis. All the tissues constituting the metacarpophalangeal joint were readily identified. The most significant increase finding regarded the soft tissues on the palmar aspect of the metacarpophalangeal joint and their interactions with the proximal sesamoid bones. The equine metacarpophalangeal joint has not previously been evaluated using 3-dimensional imaging software.

Radiographic, computed tomographic and magnetic resonance imaging evaluation of a chronic long digital extensor tendon avulsion in a dog

Long digital extensor tendon avulsion is reported in a 5 month old Great Dane. Clinically the dog presented with a unilateral weight-bearing pelvic limb lameness. Joint effusion was present and there was pain and crepitance associated with flexion of the stifle. Orthopedic evaluation and radiographs were suggestive of a long digital extensor tendon injury which was confirmed by computed tomography and magnetic resonance imaging. The injury was surgically repaired with screw and spiked washer fixation.

Rhenium-188 labeled hydroxyapatite and rhenium-188 sulfur colloid. In vitro comparison of two agents for radiation synovectomy

AIM

One therapeutic approach to rheumatoid arthritis and other inflammatory arthropathies besides surgical removal of inflamed synovium is radiation synovectomy using beta-emitting radionuclides to destroy the affected synovial tissue. Up to now the major problem associated with the use of labeled particles or colloids has been considerable leakage of radionuclides from the injected joint coupled with high radiation doses to liver and other non target organs. In this study we compared 188Re labeled hydroxyapatite particles and 188Re rhenium sulfur colloid for their potential use in radiation synovectomy.

METHODS

To this end we varied the labeling conditions (concentrations, pH-value, heating procedural and analyzed the labeling yield, radiochemical purity, and in vitro stability of the resulting radiopharmaceutical.

RESULTS

After optimizing labeling conditions we achieved a labeling yield of more than 80% for 188Re hydroxyapatite and more than 90% for the rhenium sulfur colloid. Both of the radiopharmaceuticals can be prepared under aseptic conditions using an autoclave for heating without loss of activity. In vitro stability studies using various challenge solutions (water, normal saline, diluted synovial fluid) showed that 188Re labeled hydroxyapatite particles lost about 80% of their activity within 5 d in synovial fluid. Rhenium sulfur colloid on the other hand proved to be very stable with a remaining activity of more than 93% after 5 d in diluted synovial fluid.

CONCLUSION

These in vitro results suggest that 188Re labeled rhenium sulfur colloid expects to be more suitable for therapeutic use in radiation synovectomy than the labeled hydroxyapatite particles.

Spontaneous establishment of an Epstein-Barr virus-infected fibroblast line from the synovial tissue of a rheumatoid arthritis patient

An Epstein-Barr virus (EBV)-infected fibroblast line, designated DSEK, was spontaneously established from synovial tissue of a patient with rheumatoid arthritis (RA). DSEK cells expressed EBV nuclear antigens EBNA-1 and EBNA-2 and latent membrane protein LMP-1. Cell surface markers of DSEK cells were similar to those of EBV-negative fibroblast clones derived from synoviocytes and were negative for lymphocyte and macrophage markers. DSEK cells expressed CD44, CD58, and HLA-DR antigens and spontaneously produced interleukin-10 basic fibroblast growth factor and transforming growth factor beta1. These results indicate that rheumatoid synoviocytes can be a target for EBV infection and suggest that EBV may play a role in the pathogenesis of RA.