Tomomi Watanabe — Page 2

PubMed2002

Lymphangitis of the foot demonstrating lymphatic drainage pathways from the sole.

BACKGROUND: There are two main lymphatic routes from the lower extremity: the fibular route to the popliteal node and the tibial route to the distant groin node. However, little is known about lymphatics from the sole. OBJECTIVE: We attempted to obtain detailed knowledge of the lymphatics from the sole. METHODS: Eight patients with lymphangitis were examined and compared with the drainage patterns visualized by blue-dye injection in 7 cases of melanoma. RESULTS: Six lymphangitic streaks started from the lateral edge of the plantar surface, 2 from the heel, and 1 each from the center of the sole and the little toe. All streaks ran to the tibial side and went up along the foot branch of the great saphenous vein. These findings were similar to those of the dye-injected melanoma cases. CONCLUSION: Lymphangitis makes visualization of lymphatic routes possible and may provide useful information about drainage.

Adult↗

PubMed2001

Activation of extracellular signal-regulated kinase by ultraviolet is mediated through Src-dependent epidermal growth factor receptor phosphorylation. Its implication in an anti-apoptotic function.

Ultraviolet (UV) irradiation stimulates stress-activated protein kinase/c-Jun N-terminal kinase (SAPK/JNK), which is a member of the mitogen-activated protein kinase (MAPK) superfamily and implicated in stress-induced apoptosis. UV also induces the activation of another MAPK member, extracellular signal-regulated kinase (ERK), which is typically involved in a growth-signaling cascade. However, the UV-induced signaling pathway leading to ERK activation, together with the physiological role, has remained unknown. Here we examined the molecular mechanism and physiological function of UV-induced ERK activation in human epidermoid carcinoma A431 cells that retain a high number of epidermal growth factor (EGF) receptors. UV-induced ERK activation was accompanied with the Tyr phosphorylation of EGF receptors, and both responses were completely abolished in the presence of a selective EGF receptor inhibitor (AG1478) or the Src inhibitor PP2 and by the expression of a kinase-dead Src mutant. On the other hand, SAPK/JNK activation by UV was partially inhibited by these inhibitors. UV stimulated Src activity in a manner similar to the ERK activation, but the Src activation was insensitive to AG1478. UV-induced cell apoptosis measured by DNA fragmentation and caspase 3 activation was enhanced by AG1478 and an ERK kinase inhibitor (U0126) but inhibited by EGF receptor stimulation by the agonist. These results indicate that UV-induced ERK activation, which provides a survival signal against stress-induced apoptosis, is mediated through Src-dependent Tyr phosphorylation of EGF receptors.

Animals↗