[Nonablative fractional lasers: Acne scars and other indications]. / Nichtablative fraktionierte Lasertherapie : Aknenarben und weitere Indikationen.

Nonablative photothermolysis has become an established technique in laser dermatology. It is mainly used for restructuring dermal connective tissue in order to treat, for example, acne scars or solar elastosis. It is also applied to the treatment of melasma and other benign cutaneous pigment disorders. This article discusses various indications in light of published observations and with regard to practical considerations.

Early detection of premalignant conditions in the colon by fluorescence endoscopy using local sensitization with hexaminolevulinate.

BACKGROUND AND STUDY AIMS: We aimed to determine the feasibility of obtaining selective fluorescence of precancerous/cancerous lesions in the colon with a new fluorescence video endoscope system in combination with the selective photosensitizer precursor hexaminolevulinate (HAL), and to carry out a dose-finding study with evaluation of the optimal dose and application time. PATIENTS AND METHODS: 12 patients with colorectal lesions underwent sensitization with locally applied HAL enemas in two concentrations (0.8 mmol and 1.6 mmol). The examination was conducted either 30 or 60 minutes after rectal administration of the sensitizer, using a special light source capable of delivering either white or blue excitation light. Red fluorescence induced by illumination with blue light was detected via a prototype fluorescence video colonoscope. Biopsies were taken from suspicious areas found with white or blue light. Corresponding endoscopic, fluorescence, and microscopic findings were compared. RESULTS: Using histological findings as the gold standard, 52/53 of the premalignant/malignant lesions showed red fluorescence under the photodynamic diagnosis (PDD) examination; 38/53 were detected with white-light endoscopy. The PDD mode showed 28 % more polyps than did white-light endoscopic imaging. The greatest fluorescence intensity in precancerous lesions was found with retention for 60 minutes of 500 ml of 1.6 mmol HAL. CONCLUSIONS: Administration of HAL enema induces selective lesion fluorescence and increases the lesion detection rate in patients with colorectal adenoma and early carcinoma.

[Light, laser and PDT therapy for acne]. / Licht-/Laser-/PDT--Therapie bei Akne.

In recent years, a number of studies have evaluated the treatment of acne using electromagnetic waves, such as lasers, photodynamic therapy, visible light or radio waves. While the efficacy of laser treatment is still uncertain, photodynamic therapy shows promising results, but with marked side-effects, as destruction of sebaceous glands. Treatment with blue light (405-420 nm wavelength) also appears effective and can be regarded as an treatment option for inflammatory acne.

PUVA inhibits DNA replication, but not gene transcription at nonlethal dosages.

The combination of psoralens and UVA radiation (PUVA photochemotherapy) is an established treatment for many skin disorders. UVA-induced psoralen-DNA interactions are assumed to contribute to the cutaneous anti-inflammatory and anti-proliferative effects of PUVA. PUVA-induced DNA modifications might interfere not only with DNA replication, but also with gene transcription of proinflammatory genes. We therefore studied the effect of PUVA on cell proliferation and on the transcription of the c-jun and intercellular adhesion molecule-1 genes in a promyelocytic (HL60) and a keratinocyte (HaCaT) cell line. PUVA inhibited cell proliferation increasingly with increasing 8-methoxypsoralen concentrations or UVA doses. The inhibition was observed at conditions not affecting cell viability up to 48 h after PUVA. In contrast, PUVA did not inhibit gene transcription at anti-proliferative, yet nonlethal conditions. Baseline and phorbol-ester induced c-jun mRNA expression was not inhibited, nor was baseline and IFN-gamma or phorbol-ester induced intercellular adhesion molecule-1 mRNA expression. In order to assess possible transcriptional effects of PUVA-generated reactive oxygen intermediates, the reactive oxygen intermediates-sensitive transcription factor nuclear factor kappaB was assayed in mobility shift experiments. Nuclear factor kappaB-specific binding activity was not induced 1-24 h after PUVA in extracts from PUVA-treated cells when compared with controls, whereas the pro-oxidant cytokine TNF-alpha caused a marked increase in nuclear factor kappaB binding. The presented data suggest that PUVA inhibits cell proliferation, but not transcription, at nonlethal PUVA conditions. Furthermore, the data do not support a major role for PUVA-generated reactive oxygen intermediates in the regulation of gene transcription.