Ultraviolet Irradiation Induces the Accumulation of Chondroitin Sulfate, but Not Other Glycosaminoglycans, in Human Skin

Ultraviolet (UV) light alters cutaneous structure and function. Prior work has shown loss of dermal hyaluronan after UV-irradiation of human skin, yet UV exposure increases total glycosaminoglycan (GAG) content in mouse models. To more fully describe UV-induced alterations to cutaneous GAG content, we subjected human volunteers to intermediate-term (5 doses/week for 4 weeks) or single-dose UV exposure. Total dermal uronyl-containing GAGs increased substantially with each of these regimens. We found that UV exposure substantially increased dermal content of chondroitin sulfate (CS), but not hyaluronan, heparan sulfate, or dermatan sulfate. UV induced the accumulation of both the 4-sulfated (C4S) and 6-sulfated (C6S) isoforms of CS, but in distinct distributions. Next, we examined several CS proteoglycan core proteins and found a significant accumulation of dermal and endothelial serglycin, but not of decorin or versican, after UV exposure. To examine regulation in vitro, we found that UVB in combination with IL-1α, a cytokine upregulated by UV radiation, induced serglycin mRNA in cultured dermal fibroblasts, but did not induce the chondroitin sulfate synthases. Overall, our data indicate that intermediate-term and single-dose UVB exposure induces specific GAGs and proteoglycan core proteins in human skin in vivo. These molecules have important biologic functions and contribute to the cutaneous response to UV

Loading is more effective than posture in lumbar spinal stenosis: a study with a treadmill equipment

The objective of this study was to assess the correlation between neurogenic intermittent claudication (NIC) in LSS and different positions as well as loading status, using the treadmill device. The study was a prospective clinical trial on lumbar spinal stenosis (LSS) using a treadmill equipment. The study population comprised of 80 LSS patients with a mean age of 61. The equipment included a treadmill, unloading station and loading vests. The patients were instructed to walk in five different positions. The initiation time of symptoms and total walking time were recorded. The examination was stopped after 20 min or at the onset of severe symptoms. In order to obtain pretest demographic data on subjects, visual analog scale, Roland–Morris questionnaire, pain disability index, and Beck depression index were used. The initiation time of symptoms (ITS) and total walking time (TWT) were measured during the test. Unloading provided a longer and loading a shorter ITS and TWT. Decline or incline positions did not affect ITS or TWT. The changes in posture had no correlation with the appearance of symptoms in LSS patients with NIC on a treadmill in this study, rather ITS and TWT were determined by axial loading and unloading