Intra-articular rheumatoid nodules of the knee joint

Intra-articular rheumatoid nodules found in 6 knee joints of 4 patients with rheumatoid arthritis were reported with histological findings. All patients were women, ranging in age from 32 to 61 years, with 6 to 41-year history of rheumatoid arthritis. The masses were exclusively in the anterolateral aspect of the joint. Snapping occurred when the joint was flexed by 20 degrees in four joints and by 60 degrees in two. The masses had the sizes of a thumb tip to index-finger tip, and were elastic and soft. Histologic examination of the masses revealed the typical formation of rheumatoid nodule in two joints. Myxomatous degeneration and granulation tissue consistent with rheumatoid arthritis were found in two joints. Perivascular fibrosis and myxomatous degeneration were mainly demonstrated in two joints which had developed masses two months before excision.     

The dual function of hepatic SOCS3 in insulin resistance in vivo

Inflammation associates with insulin resistance, which dysregulates nutrient homeostasis and leads to diabetes. The suppressor of cytokine signaling 3 (SOCS3), which is induced by pro-inflammatory cytokines, such as TNFalpha and IL-6, has been implicated in inflammation-mediated insulin resistance in the liver and adipocytes. However, no genetic evidence has been provided for the involvement of SOCS3 on insulin resistance. Here, we generated hepatocyte-specific SOCS3-deficient (L-SOCS3 cKO) mice and examined insulin sensitivity. Being consistent with a previous idea, the loss of SOCS3 in the liver apparently improved insulin sensitivity. However, unexpectedly, L-SOCS3 cKO mice exhibited obesity and systemic insulin resistance with age. Insulin signaling was rather suppressed in muscles, suggesting that deletion of the SOCS3 gene in the liver modulates insulin sensitivity in other organs. Anti-inflammatory reagent, sodium salicylate, partial improved insulin resistance of aged L-SOCS3 cKO mice, suggesting that enhanced inflammatory status is associated with the phenotype of these mice. STAT3 was hyperactivated and acute-phase proteins were elevated in L-SOCS3 cKO mice liver, which were reduced by sodium salicylate treatment. We conclude that hepatic SOCS3 is a mediator of insulin resistance in the liver; however, lack of SOCS3 in the liver promotes systemic insulin resistance by mimicking chronic inflammation.     

Suppressor of cytokine signaling 1 protects mice against concanavalin A-induced hepatitis by inhibiting apoptosis

Iron overload exacerbates various liver diseases. In hepatocytes, a portion of non-heme iron is sequestered in lysosomes and endosomes. The precise mechanisms by which lysosomal iron participates in hepatocellular injury remain uncertain. Here, our aim was to determine the role of intracellular movement of chelatable iron in oxidative stress-induced killing to cultured hepatocytes from C3Heb mice and Sprague-Dawley rats. Mitochondrial polarization and chelatable iron were visualized by confocal microscopy of tetramethylrhodamine methylester (TMRM) and quenching of calcein, respectively. Cell viability and hydroperoxide formation (a measure of lipid peroxidation) were measured fluorometrically using propidium iodide and chloromethyl dihydrodichlorofluorescein, respectively. After collapse of lysosomal/endosomal acidic pH gradients with bafilomycin (50 nM), an inhibitor of the vacuolar proton-pumping adenosine triphosphatase, cytosolic calcein fluorescence became quenched. Deferoxamine mesylate and starch-deferoxamine (1 mM) prevented bafilomycin-induced calcein quenching, indicating that bafilomycin induced release of chelatable iron from lysosomes/endosomes. Bafilomycin also quenched calcein fluorescence in mitochondria, which was blocked by 20 microM Ru360, an inhibitor of the mitochondrial calcium uniporter, consistent with mitochondrial iron uptake by the uniporter. Bafilomycin alone was not sufficient to induce mitochondrial depolarization and cell killing, but in the presence of low-dose tert-butylhydroperoxide (25 microM), bafilomycin enhanced hydroperoxide generation, leading to mitochondrial depolarization and subsequent cell death. CONCLUSION: Taken together, the results are consistent with the conclusion that bafilomycin induces release of chelatable iron from lysosomes/endosomes, which is taken up by mitochondria. Oxidative stress and chelatable iron thus act as two "hits" synergistically promoting toxic radical formation, mitochondrial dysfunction, and cell death. This pathway of intracellular iron translocation is a potential therapeutic target against oxidative stress-mediated hepatotoxicity.     

Multilating rheumatoid arthritis associated with sarcoidosis: A case report

Summary We describe a case of sarcoidosis with opera-glass fingers and outstanding flexion deformity of both knees. Histological examination of skin eruptions and transbronchial lung biopsy revealed the existence of noncaseating epithelioid granuloma. However, the synovial tissue showed chronic inflammation consistent with rheumatoid arthritis without any epithelioid lesions.     

Painful snapping in rheumatoid knees

Summary. Painful snapping caused by a solitary intra-articular nodular mass was found in 11 knee joints of 8 patients with rheumatoid arthritis. The masses were characteristically situated in the anterolateral aspect of the lateral femoral condyle of each joint, and appeared to jump and slip in and out of the patellofemoral articulation during flexion and extension. The snapping caused by the solitary mass was noticed as the joint flexed from 15° to 30° in 9 knees and from 50° to 60° in 3. Histopathological examination of the masses revealed typical findings of a rheumatoid nodule in 4 knee joints and myxomatous degeneration and collagen necrosis in 7.

---

Résumé. 11 genoux présentant un ressaut douloureux à cause d’un nodule intra-articulaire ont été opérés chez 8 patients atteints d’arthrite rhumato? de. Les nodules se situaient sur la face latérale du condyle fémoral externe et s’introduisaient dans l’articulation fémoro-patellaire lors de la flexion du genou. Le ressaut survenait aux environs de 15 à 30° de flexion pour 9 genoux et 50 à 60° de flexion pour 3. L’examen histologique a montré un aspect typique de nodule rhumato?de dans 4 cas et une dégénérescence myxo?de avec nécrose collagène dans les 7 autres cas.

---

---

Accepted: 19 March 1997     

Age-related quadriceps-dominant muscle atrophy and incident radiographic knee osteoarthritis

Muscle atrophy is common in the elderly. However, the etiologic role of muscle atrophy associated with osteoarthritis of the knee has not been studied in detail. We assessed the association between age-related muscle atrophy around the knee joint and incident radiographic osteoarthritis of the knee. Twenty-one women in their thirties and 17 women in their sixties participated. They had no history, symptoms, or objective findings of any knee problems, and none of the participants was limited in performing daily activities. Radiographs of the knee joint were graded for the presence of osteoarthritis, and the cross-sectional imaging around the knee joint was carried out using computed tomography. Incident radiographic osteoarthritis was observed in 6 of the 17 women in their sixties. Quadriceps-dominant muscle atrophy was marked in the elderly women with radiographic osteoarthritis. In a multivariate analysis, the risk of incident radiographic osteoarthritis of the knee was significantly increased among women with a higher hamstrings/quadriceps cross-sectional area ratio. The results suggest the possibility that age-related quadriceps-dominant muscle atrophy may play a role in the pathogenesis of osteoarthritis of the knee.     

A new surgical approach for treating infected epidermoid cysts using delayed primary closure

A new surgical approach for treating infected epidermoid cysts was designed. This technique involves the lesion being incised and drained on the first day, 5-7 days after which it is removed together with the cyst wall excised parallel to Langer's tension lines. The wound is then closed by delayed primary closure. We employed this method in the treatment of 12 patients and observed the average time required for recovery (n = 12) was 18.6 +/- 2.5 days (mean +/- SD) and the number of days spent at the outpatient clinic, 10.2 +/- 2.6. There has been no recurrence or secondary infections in any of the patients to date.     

Muscle belly tear of the triceps

Triceps injury at the tendo-osseous junction of the olecranon is not uncommon, but a muscle belly tear of the triceps is extremely rare. Two cases of muscle belly tears of triceps are reported. One case was treated surgically and the other conservatively.