The elastic system of normal human skin was studied by light and electron microscopy. By light microscopy three different types of fibers were observed: oxytalan, elaunin, and elastic. The most superficial ones (oxytalan fibers) are very thin and directed perpendicularly to the dermoepidermal junction. They start from a plexus with the tinctorial characteristics of elaunin fibers which is connected with the thicker elastic fibers of the reticular dermis. At the electron microscopic level the oxytalan fibers are formed by bundles of tubular microfibrils 10 to 12 nm in diameter. In the deepest layers of the dermis an amorphous material is seen in the core of these bundles. In the elaunin fibers the amorphous material is sparse, while in the elastic fibers it is abundant and compact.

No abstract

Background: Adamantiades-Behçet’s disease is a chronic systemic disorder associating oral and genital ulcerative lesions with ocular and cutaneous manifestations. Previous publications report increased superoxide production by neutrophils and macrophages, increases in cytokines and malondialdehyde (MDA), as well as low levels of enzymatic antioxidant defenses. Aim: We looked for another marker of oxidative stress in Adamantiades-Behçet’s disease: the presence of clastogenic factors (CF) in patients’ plasma. In addition, we determined plasma endproducts of lipid peroxidation (MDA). Patients and Methods: We studied 20 patients and 20 controls. The clastogenic activity was evaluated by means of cytogenetic methods. This test (CF test) detects circulating prooxidants, due to their clastogenic effects after exposure of lymphocyte cultures of healthy persons to plasma ultrafiltrates from patients. The clastogenic prooxidants are lipid peroxidation products and cytokines, in particular TNF-α. Lipid peroxidation was evaluated by the Yagi method. Results: The CF test was positive in 18 out of 20 patients, while it was negative in all 20 control persons. The mean increase in chromosomal breaks was 10.6 ± 3.8 in cultures exposed to patients’ plasma and 1.3 ± 2.4 for cultures receiving control plasma (p <0.001). The clastogenic effect of patients’ plasma ultrafiltrates was significantly inhibited by superoxide dismutase (EC 1.15.1.1), suggesting an important role of the superoxide radical in the clastogenic pathway. Thiobarbituric-acid-reactive substances (expressed as nanomoles MDA per milliliter) were also significantly increased in these patients: 10.6 ± 3.2 for patients and 6.6 ± 1.4 for controls (p <0.001). Conclusion: The presence of CF in the plasma of patients, indicating the presence of circulating prooxidants with chromosome-damaging effects, confirms an oxidative stress in Adamantiades-Behçet’s disease. The anticlastogenic effect of superoxide dismutase in vitro suggests the implication of the superoxide radical. MDA levels were also significantly increased in patients.

Background: The glycosaminoglycans metabolism is disturbed in progressive systemic sclerosis (PSS). Serum hyaluronic acid (HA) is elevated in this disease. Objective: This study was conducted to determine the HA plasma concentrations of patients with PSS according to the different stages of the disease. Methods: We studied 48 patients divided into three subgroups: subgroup 1 (n = 10), with skin compromise without evidence of other organ involvement; subgroup 2 (n = 21), with skin and esophagus involvement; subgroup 3 (n = 17), with skin, lung and other internal organ involvement. A radiometric assay was performed for quantification of HA. Results: Our results confirm the increase in plasma HA in patients with PSS. They also suggest that lung involvement is the main feature responsible for high plasma concentrations of HA. The plasma HA levels were elevated in patients compared to normals (p < 0.001). Significant differences were observed between subgroups 1 and 3 (p < 0.0l) and between subgroups 2 and 3 (p < 0.01). A positive correlation between disease severity scores and plasma HA values was observed (p < 0.01). Conclusion: An important elevation of HA plasma levels could be a serologic marker of disease severity, progression and degree of visceral involvement.