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Osteoarthritis (OA) is a disease caused by the degeneration and destruction of joint cartilage followed by peri-articular or subchondral bone formation and concomitant degeneration of other components of joints including synovium. Several animal OA models that adopt surgically induced joint instability have been developed. Analysis of those OA models indicates that increased mechanical stress exacerbates OA. In contrast, the effectiveness of physical therapy to alleviate OA symptoms suggests that optimal mechanical stimulation can impede the progression of OA. We propose that there are two facets of mechanical stress in light of the influence on OA ; one is detrimental, whilst the other is beneficial for articular cartilage and other joint compositions. From the malalignment and incongruity that underlie hip OA succeeding to congenital hip dislocation (acetabular hypoplasia) and the varus (or valgus) deformity observed in knee OA, shear force appears to prone to be a villain mechanical stress. On the other hand, compressive force may facilitate the maintenance or turnover of the articular cartilage unless it becomes excessive. Although essential differences between detrimental and beneficial mechanical stresses remain elusive, we speculate that the degree or magnitude of the deformation of mechano-sensor(s) may be crucial. Uncovering the mechano-sensing machinery in joints may demarcate the beneficial mechanical stress, and bring about a paradigm shift in the therapeutic strategy for OA.

In vitro properties of a new hydroxypyridone antimycotic rilopirox (RIL) with special reference to its anti-Candida activities were studied in comparison with the three reference drugs, ciclopirox olamine (CPO), oxiconazole nitrate (OCZ) and isoconazole nitrate (ICZ), using several strains of Candida albicans and Candida glabrata as the test organisms. RIL was potently fungicidal for growing cultures of these Candida strains, whereas all the three reference drugs were slightly fungicidal or fungistatic. Unlike OCZ and ICZ whose anti-Candida activity was decreased by lowering pH or adding serum to culture media, the activity of RIL was scarecely affected by change in pH or serum addition. However, RIL became less potent in the presence of Fe3+ at concentrations of 10(-5) mmol/ml or above. These findings suggest that RIL will be useful as a topical anti-Candida agent.

In vitro antifungal activities of rilopirox (RIL), a new topical hydroxypyridone antifungal agent, were studied against 7 species (31 strains) of yeast-like fungi and 15 species (17 strains) of mycerial fungi from stock cultures of a wide range of medically important fungi. Tests were carried out by the liquid dilution method using Neopeptone dextrose broth with ciclopirox olamine (CPO) and oxiconazole nitrate (OCZ) as reference drugs. RIL exhibited a broad spectrum of antifungal activities; the MIC of RIL against yeasts were about 1 microgram/ml, those against other fungi were 0.5-4 micrograms/ml. Antifungal activities were similar to CPO, and compare to OCZ, RIL showed characteristically little differences in its activities against different species or strains of target organisms.

Neurogenic tumors of the mediastinum with an intraspinal component connected by a narrowed segment in the intervertebral one are generally described as dumbbell or hour-glass tumors, which need cautious and precise diagnoses and remedies, compared with other neurological tumors. A 62-year-old male was admitted to our hospital for abnormal tumor shadow in the chest X-ray film. We diagnosed this case as dumbbell type neurogenic tumor by MRI and CT. An operation was performed by modified Grillo's method: One-stage operation. With patient in prone position, L-shaped skin incision was made. Through total laminectomy of T-5 and T-6 and resection of the 6th rib, paravertebral portion of the tumor was removed, and thoracotomy in the same position under the same view enabled us to remove the residual tumor. Histopathological diagnosis was schwannoma. After the operation, no neurological complications were detected.

Glucocorticoids administration presumably affects the vascular system and causes avascular necrosis of the femoral head. However, the mechanism by which this occurs is still unknown. In order to clarify the action of glucocorticoids on the vascular system, we investigated the effects of dexamethasone on an angiogenesis model in vitro. The angiogenesis model was obtained by co-culturing vessel fragments and myofibroblastic cells from rat epididymal fat pads. In this model, myofibroblastic cells induce capillary formation by producing an endothelial cell growth factor and collagen. Dexamethasone at physiological doses inhibited significantly capillary growth by suppressing the collagen synthesis by myofibroblastic cells. However, dexamethasone had no effect on endothelial cells. These results indicate that glucocorticoids are related to the pathogenesis of avascular necrosis of the femoral head by inhibiting the repair of the vascular system in vivo.