Sarcoglycan and integrin localization in normal human skeletal muscle: a confocal laser scanning microscope study.

Many studies have been performed on the sarcoglycan sub-complex and a7B and b1D integrins, but their distribution and localization patterns along the non-junctional sarcolemma are still not clear. We have carried out an indirect immunofluorescence study on surgical biopsies of normal human skeletal muscle, performing double localization reactions with antibodies to sarcoglycans, integrins and sarcomeric actin. Our results indicate that the tested proteins colocalize with each other. In a few cases, a-sarcoglycan does not colocalize with the other sarcoglycans and integrins. We also demonstrated, by employing antibodies to all the tested proteins, that these proteins can be localized to regions of the sarcolemma corresponding either to the I-band or A-band. Our results seem to confirm the hypothesis of a correlation between the region of the sarcolemma occupied by costameric proteins and the metabolic type (fast or slow) of muscle fibers. On this basis, we suggest that slow fibers are characterized by localization of costameric proteins to I-bands, while fast fibers are characterized by localization of costameric proteins to A-bands. The results open a new line of research in understanding interactions between the components of the DGC and vinculin-talin-integrin complexes in the context of different fiber types. Moreover, the same results may be extended to skeletal muscle fibers affected by neuromuscular diseases to detect possible structural alterations.

Cutaneous leukocytoclastic vasculitis and renal cancer: two cases.

We report two cases of cutaneous leukocytoclastic vasculitis (CLV) leading to the discovery of an as yet asymptomatic, surgically curable clear cell carcinoma of the kidney. CLV causative factors or associated diseases are usually drugs, infection, or collagen vascular disease, but rarely malignancies. In such cases, these are more often malignant hematologic diseases than solid neoplasms. We believe that in apparently idiopathic CLV, a screening examination should be done to detect any underlying early-stage curable solid malignancy.

Increased expression of tenascin in the dermis in scleroderma.

The expression of tenascin, a recently discovered extracellular matrix protein, was studied by immunohistochemical techniques in scleroderma skin and compared with its distribution in normal skin. In progressive systemic sclerosis, a marked increase in tenascin content was observed in the superficial reticular dermis. In localized scleroderma, the deposition of tenascin was increased both in the superficial and deep dermis of involved skin, whereas in clinically uninvolved skin the distribution of tenascin was the same as in normal control skin, i.e. the papillary dermis and peri-appendiceal zone. The distribution of tenascin did not strictly parallel that of fibronectin. These findings and the current knowledge of tenascin biology suggest that the overproduction of tenascin in scleroderma dermis could be secondary to stimulation of fibroblasts by immune cell-derived cytokines, or could be due to abnormal fibroblasts, or a subpopulation of fibroblasts, producing high levels of this extracellular matrix protein.

Comparative study of ketoconazole 2% foaming gel and betamethasone dipropionate 0.05% lotion in the treatment of seborrhoeic dermatitis in adults.

Sixty-two patients with seborrhoeic dermatitis were treated topically with a 2% ketoconazole foaming gel or with a 0.05% betamethasone dipropionate lotion in a single-blind study for 4 months. Changes in the number of Pityrosporum ovale were scored by a mycologist. The investigator rated the severity of erythema, scaling and itching of the patients' scalp, eyelashes, nasolabial folds and thorax. In addition, both the investigator and the patients evaluated the treatments globally. At the end of treatment, the response rate for ketoconazole 2% foaming gel was significantly higher than that for betamethasone dipropionate 0.05% lotion according to the global evaluation by the physician (89 vs. 62%, p less than 0.05) and the patient (89 vs. 65%, p less than 0.05). Ketoconazole was also superior to betamethasone with reference to the evolution of the symptoms, irrespective of their localization. This efficacy manifested itself by a significant reduction of the number of P. ovale on the scalp in the ketoconazole group (p less than 0.001) compared to the betamethasone group, in which the count was hardly changed during therapy. The treatment was also better tolerated in the ketoconazole group (5 vs. 16 patients with side-effects, p less than 0.001). It is concluded that ketoconazole 2% foaming gel offers an excellent alternative to local corticosteroids in the treatment of seborrhoeic dermatitis.