Full-thickness skin rejuvenation by a novel dual-length microneedle radiofrequency device: A proof-of-concept study using human skin.

BACKGROUND: A novel dual-length microneedle radiofrequency (DLMR) device has been developed to achieve full-thickness skin rejuvenation by stimulating the papillary and reticular dermis simultaneously. This device's dual-level targeting concept need to be validated on human skin, although its clinical efficacy has been demonstrated in a previous study. OBJECTIVES: This study evaluated the dual-depth targeting capability and the ability to induce rejuvenation in each layer of vertical skin anatomy, that is, the epidermis, papillary dermis, and reticular dermis, using full-thickness human facial skin samples. METHODS: Human facial skin samples were obtained from 13 Asian patients who had facelift surgery. To validate the dual-depth targeting concept, DMLR-treated skin samples were analyzed using a digital microscope, thermal imaging, and hematoloxylin and eosin (H&E) staining immediately after DLMR application. On samples stained with H&E, Masson's tricrome, and Verhoeff-Van Gieson, histological observation and morphometric analysis were performed. Total collagen assay (TCA) and quantitative real-time polymerase chain reaction (qPCR) were used to assess changes in total collagen content and mRNA expression levels of collagen types I/III and vimentin, respectively. RESULTS: The DLMR device successfully induced thermal stimulation in the papillary and reticular dermis. The thickness, stacks, and dermal-epidermal junction convolution of the epidermis treated with DLMR were significantly increased. Collagen bundles in the dermis treated with DLMR exhibited a notable increase in thickness, density, and horizontal alignment. Dermal collagen levels were significantly higher in the morphometric and TCA data, as well as in the qPCR data for dermal matrix proteins. CONCLUSIONS: Our DLMR device independently and precisely targeted the papillary and reticular dermis, and it appears to be an effective modality for implementing full-thickness rejuvenation.

Plasmodium vivax malaria in the Republic of Korea during 2004-2005: changing patterns of infection.

Vivax malaria re-emerged in the Republic of Korea (ROK) in 1993. The annual incidence of this disease, which had increased rapidly through 2000 with geographic expansion, started to decrease in 2001, reaching 864 cases in 2004; however, the trends changed in 2005 when 1,304 cases were reported. Among 2,168 cases of vivax malaria reported from 2004 through 2005, 389 cases (17.9%) were ROK military personnel, 565 cases (26.1%) were veterans who had been discharged from the military within 2 years of report of infection, and 1,214 cases (56.0%) were civilians. Local transmission might have taken place during this period in the southern side of the Demilitarized Zone. Regional increase of vivax malaria in North Korea, increased local transmissions in ROK, and active transmission by vector mosquitoes during the transmission season might be important factors responsible for the re-increase of vivax malaria in ROK during 2005.