We examined the effect of ultraviolet (UV) irradiation on the expression of cyclooxygenases in cultured HaCaT keratinocytes and in human skin in vivo. UVB irradiation (10 and 50 mJ/cm2) and hydrogen peroxide (200 micromol/L) increased cyclooxygenase-2 mRNA expression in HaCaT keratinocytes. No clear expression of cyclooxygenase-1 mRNA was detected in either control or stimulated HaCaT cells. Genistein, a tyrosine kinase inhibitor, suppressed both the basal and stimulated expression of cyclooxygenase-2 in HaCaT cells. UVB-induced cyclooxygenase-2 mRNA expression was partly inhibited by the antioxidant N-acetylcysteine and by H-7, a non-specific inhibitor of protein kinase C. Solar-simulated irradiation (40 mJ/cm2) was found to induce in vivo both cyclooxygenase-2 mRNA and protein expression in human skin, whereas the expression of cyclooxygenase-1 mRNA remained at the basal level. Our results show that cyclooxygenase-2 expression is induced by UV irradiation and suggest that tyrosine kinases and reactive oxygen intermediates are involved in this induction of cyclooxygenase-2.
Cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase-2 (NOS-2) each have an important role in angiogenesis. The expression of these genes was investigated in human prostate cancer by immunohistochemistry, the expression of COX-1 and COX-2 being confirmed by mRNA analysis. Prostate cancer specimens from 12 patients were compared to control prostates from 13 patients operated on for bladder carcinoma. The intensity of COX-2 and NOS-2 immunostaining was significantly stronger in prostate cancer cells than in the non-malignant glandular epithelium of the control prostates. COX-2 and NOS-2 were clearly also expressed in the lesions of prostatic intraepithelial neoplasia (PIN) in control prostates. COX-2 was detected in the muscle fibres of the hyperplastic stroma of some control prostates. No significant difference was detected in COX-1 expression between control and cancer prostates. These results indicate that the expression of COX-2 and NOS-2 is elevated in prostatic adenocarcinoma and in PIN.
Continuous epidural bupivacaine/fentanyl analgesic regimen, started preoperatively, reduces the amount of myocardial ischaemia in elderly patients with hip fracture.
In a double-blind trial patients with atopic eczema received either oral evening primrose oil (EPO) (n = 14) or placebo (n = 11) for 12 weeks. In the EPO group a statistically significant improvement was observed in the overall severity and grade of inflammation and in the percentage of the body surface involved by eczema as well as in dryness and itch. Patients in the placebo group showed a significant reduction in inflammation. The patients receiving EPO showed a significantly greater reduction in inflammation than those receiving placebo. Evening primrose oil caused a significant rise in the amount of dihomogammalinolenic acid in the plasma phospholipid fatty acids. Plasma levels of TXB2, 6-keto-PGF1 alpha and PGE1, and the amount of TXB2 released into serum during clotting were not altered by evening primrose oil.
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