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AIM:To explore the role of sphingosine 1-phosphate (S1P) in the dysfunction of vascular endo-thelial cells exposed to high glucose.METHODS: In human aortic endothelial cells cultured under high-glucose ( 22 mmol/L glucose) medium, nitric oxide ( NO) level, polymorphonuclear neutrophil-endothelial cell adhesion rate, protein level of intercellular adhesion molecule-1 ( ICAM-1) , migration of endothelial cells and Akt/endothelial nitric oxide syn-thase ( eNOS) pathway activation were observed after S1P, sphingosine kinase-1 inhibitor and/or Akt inhibitor treatments. RESULTS:S1P decreased NO level, increased polymorphonuclear neutrophil adhesive rate, enhanced ICAM-1 protein level, and inhibited migration of endothelial cells and activation of Akt/eNOS pathway in endothelial cells cultured under high-glucose condition.Sphingosine kinase-1 inhibitor, which reduced S1P content, significantly improved the above endo-thelial cell function indexes and restored the activation of Akt/eNOS pathway.CONCLUSION: S1P promoted high glu-cose-induced dysfunction of endothelial cells probably by inhibiting the activation of Akt/eNOS signal pathway.Targeting S1P is expected to become one of potential treatment strategies to reduce endothelial cell dysfunction.
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OBJECTIVE: To set up a natural degeneration model of chondrocytes derived from endplate of intervertebral discs of rats in order to offer an appropriate carrier for the study on mechanism of intervertebral disc degeneration. METHODS: The method of enzyme digestion combined with natural subculture was used to set up the in vitro natural degeneration model of chondrocytes derived from the endplate of intervertebral disc of rats. The morphological appearances and microstructures of the chondrocytes of different generations were observed. The expression of collagen II in chondrocytes was detected by immunocytochemical method. RESULTS: The chondrocytes derived from the endplate of intervertebral disc expressed collagen II. After 13 days of culture, the chondrocytes of generation III showed that the ability of cell division descended, the nucleoli became unclear, the cells deformed obviously, fusiform shape with weak optical activity appeared, and the intercellular space was enlarged. There were vacuoles and lipid droplets in cytoplasm. The synthesis of collagen II, as well as the cell proliferation rate, descended notably. All results showed the natural degeneration process of the chondrocytes. CONCLUSION: The in vitro natural degeneration model of chondrocytes derived from endplate of intervertebral discs of rats was successfully established. This can offer the cytological basis for study on the mechanism of intervertebral disc degeneration.
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<p><b>OBJECTIVE</b>To evaluate the effects of early tangential excision on the prevention of the progression of deep partial thickness burn wound.</p><p><b>METHODS</b>Twelve burn patients with deep partial thickness burn wound were enrolled and received tangential excision of the burn wound within 24 postburn hours (PBHs). The histological samples were harvested from the wound before and 5 - 7 postoperative days (PODs) after the operation and the wound without operation 5 - 7 postburn days (PBDs). The samples were observed by means of HE staining, Masson's staining and the labelling of Vimentin antigen positive cells by immunohistological skill.</p><p><b>RESULTS</b>The inflammatory reaction of the burn wound without operation aggravated progressively along with that of disease and the tissue necrosis area enlarged. And the residual skin appendages disappeared due to the enhanced inflammatory reaction. The brown area expanded and light green area shrinked by Masson's staining. The Vimentin antigen positive cell count decreased significantly. But in the burn wound being performed tangential excision within 24 PBHs, focal inflammatory reaction exhibited evident ligher than that in burn wound without operation. Moreover, there appeared fresh granulation formation and partial epithelial coverage with no enlarged necrotic tissue area in the operated wound when compared with that in non-operated wound (P < 0.05). Furthermore, the light green area exhibited no obvious shrinking by Masson's staining and the Vimentin antigen positive cell count was much more in the operation area than that in non-operative area (P < 0.05).</p><p><b>CONCLUSION</b>It might be beneficial to the host to perform tangential excision within 24 PBHs, which could remove burn wound necrotic tissue in time and hamper the progression of tissue degenerative injury. The healing process of deep partial thickness burn wound was therefore accelerated.</p>
Subject(s)
Adult , Female , Humans , Male , Burns , Metabolism , Pathology , Necrosis , Vimentin , Wound HealingABSTRACT
<p><b>OBJECTIVE</b>To evaluate the influence of necrotic tissue on progressive injury in deep partial thickness burn wounds.</p><p><b>METHODS</b>Tissue specimens were cultured both for estimation of IL-8, EGF, bFGF, PDGF-AB and histopathological examination, from the pre-operation, post-operation, and non-operation wounds from seven patients with deep partial thickness burn.</p><p><b>RESULTS</b>In seven specimens from the non-operation group, IL-8 release increased compared with those in the post-operation group (P < 0.001), while the levels of EGF, bFGF, PDGF-AB release were lower than those in the post-operation group. Histopathological examination revealed that in the non-operation group, the degree of neutrophil infiltration was enhanced, the extent of tissue necrosis enlarged, and residual skin appendages disappeared. In contrast, in the post-operation group, the degree of inflammatory response was decreased, with the formation of fresh granulation tissue and epithelialization.</p><p><b>CONCLUSION</b>This study suggests that the presence of necrotic tissue could be the inhibitory factor in the wound healing process, as it might cause tissue progressive injury leading to the delay of wound healing. To promote wound healing, active tangential excision is recommended to remove necrotic tissue.</p>