Souji Maruo

Monoclonal expansion of synoviocytes in rheumatoid arthritis

OBJECTIVE To examine whether synoviocytes from patients with rheumatoid arthritis (RA) have a stronger growth ability than those from patients with osteoarthritis (OA), and to determine whether these synoviocytes clonally expand in situ. METHODS Synovial tissues from 13 RA patients and 4 OA patients were cultured, and their ability to form colonies in soft agarose was examined. RA and OA synoviocytes were also examined in varying concentrations of fetal calf serum (FCS)-containing medium to test the effects of FCS on colony formation. DNA was extracted from clones with colony-forming ability in nonpannus lesions and from synoviocytes in pannus lesions. Restriction fragment length polymorphism (RFLP) analysis was used to examine phosphoglycerate kinase 1 (PGK-1) gene patterns. Production of cytokines by these cells was also assessed. RESULTS All 13 RA synoviocytes exhibited colony formation, whereas none of the 4 OA synoviocytes did. This tendency was also seen with all of the concentrations of FCS examined, although growth varied in a dose-dependent manner. In contrast to OA synovial clones, cloned RA synoviocytes obtained from colonies exhibited a partial RFLP PGK-1 gene pattern, suggesting that the clones originated from monoclonal cells. Of note, 3 of 7 noncloned synoviocytes from pannus lesions exhibited a monoclonal pattern. Pannus cells produced high levels of transforming growth factor beta and platelet-derived growth factor. CONCLUSION These findings suggest that synoviocytes with a strong growth ability are present in the rheumatoid synovium, and that these cells expand monoclonally, particularly in pannus lesions.

Changes in phosphorylation of ERK and Fos expression in dorsal horn neurons following noxious stimulation in a rat model of neuritis of the nerve root

Mechanical compression and chemical inflammation of the spinal nerve root are considered major sensory pathologies secondary to a lumbar disc herniation. In order to elucidate the dorsal horn responsiveness to noxious stimulation to the peripheral tissue in the neuritis model of the nerve root, we examined extracellular signal-regulated kinase (ERK) phosphorylation and Fos expression in spinal cord dorsal horn neurons. Male Sprague-Dawley rats received hemilaminectomies and the implantation of disc tissue that was obtained from coccygeal intervertebral discs. Three or 7 days after surgery, rats were perfused after receiving noxious mechanical stimulation of the plantar surface of the hind paw using a hemoclip, and the L4/5 spinal cord was processed for immunohistochemistry with antibodies for phospho-ERK and Fos. The number of Fos-immunoreactive (Fos-LI) neurons and phospho-ERK-immunoreactive (phospho-ERK-LI) neurons in the neuritis group after the noxious stimulation significantly increased compared to the sham-treated group at 3 and 7 days after surgery. The change in number of phospho-ERK-LI and Fos-LI neurons occurred mainly in the superficial dorsal horn. The number of Fos-LI neurons observed when the MEK inhibitor, U0126, was administered was significantly suppressed compared to the DMSO- (vehicle control) administered group. The increase in ERK phosphorylation and Fos expression in the spinal cord dorsal horn neurons indicates that responses/activation by the noxious stimulation applied to the periphery were elevated in spinal cord neurons in this neuritis model of the lumbar nerve root. Moreover, the increase in the Fos expression in the spinal cord dorsal horn may have been the result of the activation of the MAP kinase cascade.

Effects of tension at the site of coaptation on recovery of sciatic nerve function after neurorrhaphy: evaluation by walking-track measurement, electrophysiology, histomorphometry, and electron probe X-ray microanalysis.

The effects of tension at the site of coaptation on recovery of sciatic nerve function after neurorrhaphy were studied by evaluating walking‐track measurements, nerve conduction velocity measurements, histomorphometry, and electron probe X‐ray microanalysis. Forty adult male Lewis rats underwent right sciatic nerve (SN) transection followed by one of four different nerve repair procedures (N = 10 rats per group). In Group 1, the gap was repaired by end‐to‐end epineural coaptation. In Group 2, a 5‐mm segment of SN was resected, and the defect was repaired under high tension by epineural neurorrhaphy. In Group 3, a 5‐mm segment of SN was resected, and the defect was repaired with a 5‐mm interposition nerve graft. In Group 4, a 5‐mm segment of SN was resected. Then, to lessen the tension that follows neurorrhaphy, an anchoring suture was added. Finally, end‐to‐end coaptation was performed. Walking‐track analysis showed better functional recovery in Group 1 than in Group 2, and better recovery in Group 3 than in Group 2. Group 4 showed a tendency toward better recovery comparing with Group 2. Electron probe X‐ray microanalysis revealed higher Na, Cl, and K peaks in axoplasm accompanied by increase in the endoneural fluid pressure (EFP) in Group 2 than those of Group 1. This higher level of Na, Cl and K may be due to impairment of axonal sodium and potassium transport mechanism in Group 2. Increase in EFP may affect nerve regeneration.

A Rare Combination of Sites of Involvement by Mycobacterium intracellulare in a Hemodialysis Patient: Multifocal Synovitis, Spondylitis, and Multiple Skin Lesions

Purpose: Atypical mycobacterial infection is a rare but serious hazard in immunocompromised patients including those undergoing maintenance hemodialysis and immunosuppressive therapy. Recognition of unusual involvement patterns is important. Methods: We describe an extremely rare combination of complications caused by such an organism in a patient with end-stage renal disease: spinal osteolysis and multiple skin lesions associated with synovitis. Results: The patient had received a renal allograft 18 years previously but developed infection with Mycobacterium avium-M. intracellulare complex including dermatologic manifestations, spondylitis, and synovitis involving the wrist and lateral malleolus after initiation of hemodialysis when the transplanted kidney failed. An empirical antibiotic regimen failed to alleviate skin lesions or fevers, or to lower an elevated C-reactive protein concentration, until the patient’s dose of methylprednisolone was increased to treat mild adrenal insufficiency. The increase resulted in rapid resolution of skin lesions. A compression fracture 6 months later was attributed to spondylitis caused by the same organism. Conclusion: We suspect that spondylitis represented the primary focus of M. intracellulare infection.

Clinical usefulness of serum tartrate-resistant fluoride-sensitive acid phosphatase activity in evaluating bone turnover.

Abstract: This study was carried out to evaluate the clinical validity and usefulness of serum tartrate-resistant fluoride-sensitive acid phosphatase (TrFsACP) activity using 2,6-dichloro-4-acetylphenyl phosphate as substrate at pH 6.2 in metabolic bone diseases. The mean Z-scores of TrFsACP activity in patients on hemodialysis were higher than in healthy subjects (male: 2.04 ± 1.98, n = 49, P < .05; female: 1.49 ± 2.43, n = 39, P < .05) and increased with duration of hemodialysis (r = .516, P < .01). Bone alkaline phosphatase also was found to be significantly higher in hemodialysis patients (male: 0.93 ± 1.49, P < .05; female: 1.66 ± 2.42, P < .05) compared with normal subjects; but had lower correlation with duration of hemodialysis than TrFsACP (r = .277, P < .05). Ulcerative colitis (1.37 ± 2.21, n = 15) in males showed a significantly higher Z-score of TrFsACP compared with control subjects (P < .05). The relationship of TrFsACP activity and ultrasound findings (stiffness; speed of sound [SOS]; broadband ultra sound attenuation [BUA]) in healthy women aged 30–75 years (n = 95) were inversely and significantly correlated with stiffness (r = −.465, P < .01), SOS (r = −.484, P < .01), and BUA (r = −.366, P < .01), but were age dependent. TrFsACP activity significantly correlated with stiffness (r = −.521, P < .05) and SOS (r = −.527, P < .05) only in the age group of 46–55 years. BUA (r = −.313, P > .05) did not correlate significantly in any subject in the present study. We conclude that serum TrFsACP activity is useful in the diagnosis and monitoring of bone turnover.

Experimental study of spinal cord compression by epidural tumors using electron probe X-ray microanalysis and confocal laser scanning microscopy

Changes in the nerve fibers of the spinal cord were studied in rat experimental epidural tumor models. Light microscopy showed demyelinization in all with rats paraparesis and paraplegia. Cross-sectional views of nerve fibers stained with 3,3dipentyloxacarbo-cyanine iodide, obtained by confocal laser scanning microscopy, showed distorted, shrunken fibers with a low fluorescence intensity. Changes in the electrolyte contents of nerve fibers were studied by electron probe X-ray microanalysis. The K concentration in axons and the myelin sheath was increased in the paraparesis group, but was decreased in the paraplegia group. These findings suggest that, in the paraparesis group, compression of the spinal cord damaged cell membrane channels, which subsequently caused an increase in intracellular K, a decline in the action potential, and low-intensity fluorescence of nerve fibers. On the other hand, in the paraplegia group, destruction of cell membranes caused a decrease in intracellular K until it approached the extracellular level. This reduced both the action potential and the fluorescence intensity. As Ca and Mg concentrations in both axons and the myelin sheath increased in relation to the severity of neurologic damage, it appears that these electrolytes may also play an important role in damage to nerve fibers.

A case of ochronotic arthropathy treated with total hip arthroplasty

Abstract We report a case of ochronotic arthropathy treated with total hip arthroplasty. The articular cartilage of the patients femoral head and synovium displayed black pigmentation. Microscopically, the articular cartilage revealed reddish-brown pigmentation (particularly in deep cartilage), necrotic chondrocytes, and slight black pigmentation in the cytoplasm of chondrocytes. Electron microscopy revealed electron-dense material deposited predominantly along and between collagen fibers.