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[english] Actinic keratosis is one of the most commonly treated skin conditions. A number of studies have recently been published on the treatment of this ailment using photodynamic therapy. The authors of this letter are concerned about the interpretation of some of these studies and would like to outline possible misinterpretations which may arise due to an incomplete analysis of the study reports available. Clearly, the “ideal” therapy for actinic keratosis should be a carefully chosen compromise between undesired side-effects and therapeutic efficacy and needs to be based on a consideration of all of the relevant clinical studies.[german] Aktinische Keratosen gehören zu den meistbehandelten Hautschäden. Eine Reihe der in den letzten Jahren veröffentlichten Studien beschäftigte sich mit ihrer Behandlung durch photodynamische Therapie. Die Bewertungen einiger dieser Studien veranlassten die Autoren dieses Briefes, mögliche Missinterpretationen der Daten herauszustellen, die infolge unvollständiger Analyse der einbezogenen Studienberichte und unvollständiger Berücksichtigung ihrer Randbedingungen auftreten können. Unbestritten ist dabei, dass die „ideale“ Therapie der aktinischen Keratose ein sorgfältig abgewogener Kompromiss zwischen therapeutischer Wirkung und unerwünschter Nebenwirkung sein muss, der auf der Berücksichtigung aller relevanten klinischen Studien und ihrer Randbedingungen basiert.

Purpose: Tumor perfusion is considered to be the principal factor determining the build-up of therapeutically effective thermal fields. This assumes that malignancies have lower perfusions than their homologous tissues. This assumption, however, ignores the fact that several tumor types have higher perfusions than their healthy counterparts. Additionally, flow changes upon hyperthermia (39–43 °C) are non-predictable and extremely heterogeneous. Therefore, modeling temperature distribution further requires a more robust parameter, different in malignancies and healthy tissues, i.e., water content (Cw), which highly determines thermal properties upon electromagnetic irradiation. Method: Systematic literature reviews of Cw and specific heat capacities (cp) were conducted up to 28 February 2022, providing an updated, comprehensive data overview based on original manuscripts, reviews and databases. Results: Cw- and cp-values of cancers and their corresponding healthy tissues are presented. Strong correlations between these two parameters are described. In general, malignant tumors have distinctly higher Cw values than their homologous tissues. With increasing Cw in low-water-content normal tissues (<70 wt.%), cp rises exponentially from 1.5 to 3.3 J·g–1·K–1. In high-water-content normal tissues (≥70 wt.%), cp increases linearly from 3.5 to 3.8 J·g–1·K–1. In malignant tumors (>80 wt.%), cp rises linearly from 3.6 to 3.9 J·g–1·K–1. Cancers contain up to 27% more water than their tissues of origin and must be considered as ‘high-capacitance-tissues’. Conclusions: Hyperhydration of cancers result in higher cp-values, causing cancers to be better heat reservoirs than corresponding normal tissues upon electromagnetic irradiation. Reliable, tissue-/cancer-specific cp values must be considered when modeling temperature distributions in hyperthermic treatment. [ABSTRACT FROM AUTHOR]

The aim of the study was to assess the interindividual variability of spectral remittance and spectral transmittance of visible and infrared-A radiations interacting with human skin and subcutaneous tissue, and direct measurements were taken in vivo using healthy persons of different skin color types. Up to wavelengths of about 900 nm, both spectral remittance and spectral transmittance depended significantly on the individual contents of melanin and hemoglobin in the skin, whereas the contents of water and lipids mainly determined spectral slopes of both characteristics of interaction for wavelengths above about 900 nm. In vivo measured data of spectral transmittance showed approximately similar decreases with tissue thickness between about 900 nm and 1100 nm as compared with model data which were calculated using spectral absorption and scattering coefficients of skin samples in vitro published by different authors. In addition, in vivo measured data and in vitro-based model calculations of spectral remittance were approximately comparable in this wavelength range. In contrast, systematic but individually varying differences between both methods were found for both spectral remittance and spectral transmittance at wavelengths below about 900 nm, where interaction of radiation was significantly affected by both melanin and hemoglobin. [ABSTRACT FROM AUTHOR]

Purpose:Evaluation of the efficacy and toxicity of a new setup of thermographically controlled water-filtered infra-red-A (wIRA) superficial hyperthermia (HT) combined with hypofractionated re-irradiation (re-RT) to treat large-sized breast cancer recurrences. Methods:Records of 73 heavily pre-irradiated patients with 103 treatment regions, treated from September 2009 to July 2015 were retrospectively analysed. Sixty-four patients with macroscopic disease were treated with 94 regions including 46 patients with lymphangiosis carcinomatosa. Hypofractionated RT consisted of 4 Gy once per week up to a total dose of 20 Gy delivered within 1–4 min after wIRA-HT. Heating of tumour nodules and diffusely spreading cancer lesions was performed under real-time thermographic temperature monitoring, maintaining the maximum skin temperature in the ROI between 42 °C and 43 °C, achieving intratumoural temperatures up to a depth of 2 cm between 39.5 °C and 42 °C. Seventeen patients received re-re-irradiation (re-re-RT) using the same HT/RT-treatment schedule. Results:Response rates in patients with macroscopic disease: 61% CR, 33% PR, 5% NC and 1% PD. Local control throughout life time after CR of macroscopic disease: 59%. All nine patients with microscopic disease had CR and local control throughout lifetime. Only grade 1 toxicities were observed. Conclusions:Application of thermographically controlled wIRA-HT combined with extremely low-dose re-irradiation provides good local control throughout lifetime of heavily pre-treated breast cancer recurrences. The twin wIRA radiator provides a sufficiently homogeneous heat deposition for the treatment of larger areas. The time lag between HT and re-RT is substantially reduced. The possibility of re-re-RT opens new therapeutic options for the future. [ABSTRACT FROM PUBLISHER]

Circadian dysrhythmia affects the majority of ICU patients and has far-reaching effects on organ functioning. At the level of the central nervous system, circadian misalignment facilitates executive cognitive dysfunction and the development of ICU delirium. The pathophysiological mechanisms, especially in the cohort of critically ill patients, appear to be complex, multilayered and far from understood. Results from preliminary research indicate that multidimensional, patient-specific chronotherapeutic concepts developed specifically for the ICU setting may help improve the healing process of patients. Circadian lighting therapy might be a promising intervention in this context., Competing Interests: Erklärung zu finanziellen Interessen Forschungsförderung erhalten: ja, von einer anderen Institution (Pharma- oder Medizintechnikfirma usw.); Honorar/geldwerten Vorteil für Referententätigkeit erhalten: ja, von einer anderen Institution (Pharma- oder Medizintechnikfirma usw.); Bezahlter Berater/interner Schulungsreferent/Gehaltsempfänger: ja, von einer anderen Institution (Pharma- oder Medizintechnikfirma usw.); Patent/Geschäftsanteile/Aktien (Autor/Partner, Ehepartner, Kinder) an im Bereich der Medizin aktiven Firma: nein; Patent/Geschäftsanteile/Aktien (Autor/Partner, Ehepartner, Kinder) an zu Sponsoren dieser Fortbildung bzw. durch die Fortbildung in ihren Geschäftsinteressen berührten Firma: nein. Erklärung zu nichtfinanziellen Interessen Mitgliedschaften u. a. in der DGAI, DIVI, ESICM und Deutschem Delirnetzwerk., (Thieme. All rights reserved.)

Ultraviolet irradiation represents a well-established treatment modality for inflammatory skin diseases. The aim of this study was to investigate the mechanisms of ultraviolet B radiation-induced keratinocyte insensitivity towards interferon-gamma. Flow cytometric analyses indicated that ultraviolet B radiation temporarily inhibits the interferon-gamma-induced activation of primary keratinocyte and HaCaT cells as measured by reduced intercellular adhesion molecule-1 (CD54) and HLA-DR upregulation. Western blot experiments have suggested that this is mediated by the ultraviolet B radiation-induced inhibition of signal transduction and transcription factor-1 phosphorylation. Neither interleukin-10 neutralization nor interleukin-10 addition had any effect on the ultraviolet B radiation-induced inhibition of interferon-gamma induced intercellular adhesion molecule-1 expression. Furthermore, the supernatant from ultraviolet B-irradiated cells failed to inhibit the interferon-gamma-induced CD54 and HLA-DR upregulation in nonradiated HaCaT cells. Moreover, irradiated cells from whom the supernatant was withdrawn 4 h after irradiation still showed a diminished interferon-gamma-induced response after 24 h. Thus, not soluble but intracellular factors might be involved in the ultraviolet B radiation-induced inhibition of interferon-gamma-induced keratinocyte activation. Therefore, we analyzed the expression of members of suppressors of cytokine-signaling (SOCS) molecules using real-time polymerase chain reaction. We found a fast and strong upregulation of SOCS1 and SOCS3 but not of SOCS2 after ultraviolet B radiation. Similarly, ultraviolet B radiation induced the expression of these particular SOCS molecules in lesional psoriatic skin. As SOCS molecules are known inhibitors of signal transduction and transcription factor phosphorylation, which is essential for interferon-gamma-induced intercellular adhesion molecule-1 and HLA-DR upregulation, this may explain the interferon-gamma unresponsiveness after ultraviolet B radiation.