The Impact of Blue Light Irradiation on Keratinocytes in Vitro.

BACKGROUND: This study examined the effects of irradiation with blue light on HaCaT keratinocytes. As irradiation with blue light is known to be antimicrobial, it offers a promising alternative therapy for contaminated wounds. There is evidence that red light promotes wound healing, but the potential benefits of irradiation with blue light have not yet been adequately investigated. METHODS: The rate of wound closure in sterile and contaminated cells was measured using an in vitro scratch assay wound-healing model. Additionally, cell viability after treatment was determined using a Sulforhodamine B (SRB) assay. RESULTS: In both the sterile and contaminated groups, treated cells showed delayed wound closure when compared with cells not irradiated with blue light. Additionally, treatment with blue light resulted in poorer viability in the treatment groups. CONCLUSION: Although irradiation with blue light may offer a promising alternative therapy for reducing bacterial colonization, our data indicate that re-epithelization may be negatively influenced by blue light. Further research is needed to clarify possible wound healing applications.

Immune-modulating properties of blue light do not influence reepithelization in vitro.

Phototherapy is gaining more attention in the treatment of various diseases. Especially, blue light seems to be a promising approach for wound healing promotion due to its antimicrobial and immune-modulating properties. Despite this, there is only little research focusing on the immune-modulating properties of blue light and its possible effects on wound healing. Therefore, we investigated the effects of blue light irradiation on peripheral blood mononuclear cells (PBMC) and the influence on reepithelization in vitro. PBMCs were irradiated with DermoDyne® (DermoDyne HealthCare, Berlin, Germany) and effects on cell viability, cytokine expression, and scratch wound closure were evaluated afterwards. Irradiated cells showed a higher Interleukin-γ concentration while irradiation reduced resazurin concentration in a time-dependent manner. No differences in reepithelization were detectable when keratinocytes were treated with the supernatant of these blue light irradiated PBMCs. Blue light-mediated ex vivo stimulation of PBMCs does not cause faster reepithelization in an in vitro setting. Further research is needed to investigate the wound healing effects of phototherapy with blue light.

Does Phototherapy Promote Wound Healing? Limitations of Blue Light Irradiation.

INTRODUCTION: Phototherapy is gaining increased attention in the research and treatment of various diseases. In particular, the use of blue light seems to bear promise, owing to its antimicrobial and immune-modulating properties; however, research focused on the effects of blue light on keratinocytes and reepithelization is rare. In addition, few studies to date have evaluated devices that are used in daily hospital routine. OBJECTIVE: This study investigated the effects of phototherapy on keratinocytes with 2 established devices in vitro. MATERIALS AND METHODS: Human adult low calcium high temperature keratinocytes were irradiated with 2 different devices, and the effects on scratch wound closure, proliferation, cell viability, and cytokine expression were evaluated. RESULTS: Blue light irradiation reduced reepithelization at high doses in a scratch wound healing model (wound closure on day 1: control group, 25.57 percentage points [PP] ± 2.36 standard deviation vs Device A for 10 minutes, 1.33 PP ± 1.01) and mitochondrial activity measured with resazurin conversion (Device A for 10 minutes, 33.28% ± 12.34). Irradiated cells demonstrated a lower ratio of proliferating cell nuclear antigen-positive cells and, as a result, lower proliferation. CONCLUSIONS: Blue light reduces keratinocyte proliferation and migration at high doses and therefore could negatively affect wound healing. Available irradiation devices for possible use in wound therapy should be critically scrutinized and evaluated with in vitro methods prior to clinical use.

Influence of Topical Anesthesia on Superficial Sensitivity: A Double-Blind, Randomized, Placebo-Controlled Study on 48 Healthy Subjects.

BACKGROUND: Topical anesthetics are used in noninvasive transdermal anesthesia to decrease the superficial pain sensation threshold during dermatologic surgery. Combined pain relief and sensitivity loss can avoid discomfort during the surgery. OBJECTIVE: The aim of this placebo-controlled study was to compare the efficacy of 3 commonly used topical agents by collating loss of sensitivity over time. MATERIALS AND METHODS: Three topical anesthetic creams, a topical anti-inflammatory cream, and a moisturizing cream were applied on the left volar forearm of each of the 48 healthy Caucasian participants. Sensitivity was assessed with the dynamic 2-point discrimination and the Semmes-Weinstein test at 0, 60, 90, 120, 150, and 180 minutes after cream application. RESULTS: After 180 minutes, benzocaine showed a significantly lower 2-point discrimination reduction than lidocaine alone and a lidocaine and prilocaine mixture. Sensory threshold measurements by the Semmes-Weinstein test after 60 minutes revealed a significantly higher effect with lidocaine alone and with the lidocaine and prilocaine mixture than with benzocaine. CONCLUSION: The authors found a stronger skin sensitivity reduction by the eutectic lidocaine and prilocaine mixture and lidocaine alone compared with benzocaine. We suggest increased discomfort reduction in topical anesthetic supported dermatologic surgery by the eutectic mixture and lidocaine alone.

The acute impact of local cooling versus local heating on human skin microcirculation using laser Doppler flowmetry and tissue spectrophotometry.

INTRODUCTION: Knowledge of thermally induced skin injury has increased, but its pathophysiology remains unclear. Although it is assumed that local cooling may protect tissue, little is known about the impact of local heating on human skin. This study aimed to evaluate acute skin perfusion dynamics following thermal stimuli in healthy human volunteers. MATERIAL AND METHODS: In 54 subjects, a TSA-II-NeuroSensory Analyzer was used to induce local hypothermia (15 °C and 5 °C) and local hyperthermia (40 °C and 45 °C) at the palmar forearm of healthy volunteers. Changes in tissue microcirculation were assessed using an O2C device before and after each temperature change. RESULTS: Blood flow and velocity values showed a continuous decrease with decreasing skin temperature, whereas haemoglobin oxygen saturation (SO2) showed a continuous increase in superficial (2 mm) and deep layers (8 mm). With increasing skin temperature, flow, SO2 and velocity increased in the superficial and deep layers. The relative amount of haemoglobin (rHB) did not show a continuous alteration. DISCUSSION: Local cooling may protect damaged tissue due to increased SO2 (lower oxygen consumption). However, reduced blood flow and velocity in response to local cooling limit nutrient requirements and the transport of metabolites. Despite higher oxygen consumption of tissue at higher temperatures, both blood flow and SO2 increase. Thus, we hypothesize that not only hypothermia but also hyperthermia may provide tissue protection.

Quantitative impact analysis of remote ischemic conditioning and capsaicin application on human skin microcirculation.

BACKGROUND: Improvement of skin microcirculation would be beneficial in transplanted tissues and thus, there is a demand for effective, reliable and harmless angiogenic treatments. The aim of this study was to assess the effect of capsaicin application (CA), the remote effect of capsaicin application (REC), the impact of remote ischemic conditioning (RIC), and the impact of combined remote ischemic conditioning with capsaicin application (Comb) on human skin microcirculation. METHODS: Perfusion changes were assessed using a laser Doppler device (easyLDI, Aimago Lausanne). 30 healthy volunteers were enrolled and divided into two groups: 1) CA and REC: perfusion was assessed on both forearms after application of capsaicin cream on one forearm with an exposure time of 40 minutes. 2) RIC and Comb: perfusion of one forearm was assessed after four cycles of 5 min blood occlusion and 5 min reperfusion using a tourniquet on the contralateral upper arm and application of capsaicin on the ipsilateral forearm. Baseline skin perfusion measurements of both forearms were carried out initially and were used as intra-individual reference. RESULTS: 1) Skin perfusion significantly increased after capsaicin application (CA = +328.3% , p > 0.05). There was no remote skin perfusion change due to capsaicin (REC). 2) RIC significantly improves skin perfusion (RIC = +20.0% , p < 0.05). The combination of RIC and CA does not improve skin perfusion compared to CA alone (Comb). CONCLUSIONS: The conditioning techniques RIC and CA showed a significant increase in human skin perfusion, CA being superior to RIC. However, the combination of CA and RIC showed no additional improvement potential as compared to CA alone. Furthermore, a remote effect of capsaicin application could not be demonstrated. These results encourage to analyze if the conditioning treatments are also beneficial for transplanted tissue survival.

The Triaging and Treatment of Cold-Induced Injuries.

BACKGROUND: In Central Europe, cold-induced injuries are much less common than burns. In a burn center in western Germany, the mean ratio of these two types of injury over the past 10 years was 1 to 35. Because cold-induced injuries are so rare, physicians often do not know how to deal with them. METHODS: This article is based on a review of publications (up to December 2014) retrieved by a selective search in PubMed using the terms "freezing," "frostbite injury," "non-freezing cold injury," and "frostbite review," as well as on the authors' clinical experience. RESULTS: Freezing and cold-induced trauma are part of the treatment spectrum in burn centers. The treatment of cold-induced injuries is not standardized and is based largely on case reports and observations of use. distinction is drawn between non-freezing injuries, in which there is a slow temperature drop in tissue without freezing, and freezing injuries in which ice crystals form in tissue. In all cases of cold-induced injury, the patient should be slowly warmed to 22°-27°C to prevent reperfusion injury. Freezing injuries are treated with warming of the body's core temperature and with the bathing of the affected body parts in warm water with added antiseptic agents. Any large or open vesicles that are already apparent should be debrided. To inhibit prostaglandin-mediated thrombosis, ibuprofen is given (12 mg/kg body weight b.i.d.). CONCLUSION: The treatment of cold-induced injuries is based on their type, severity, and timing. The recommendations above are grade C recommendations. The current approach to reperfusion has yielded promising initial results and should be further investigated in prospective studies.

Resveratrol induces apoptosis and alters gene expression in human fibrosarcoma cells.

BACKGROUND/AIM: Metastatic fibrosarcomas still represent a therapeutic dilemma. Commonly used chemotherapeutic agents such as doxorubicin have been proven effective in fewer than 30% of all cases disseminated of fibrosarcoma. Elderly patients with cardiac disease are not suitable for systemic chemotherapy with doxorubicin. We therefore tested the apoptotic effects of the natural and well-tolerated compound resveratrol on human fibrosarcoma cells (HT1080). MATERIALS AND METHODS: Vital, apoptotic and necrotic cells were quantified using flow cytometric analysis. Gene expression was analyzed by RNA microarrays. RESULTS: Application of resveratrol induced apoptotic cell death and significantly reduced proliferation of HT1080 cells. Correspondingly, expression of apoptosis-associated genes was altered in microarray analysis. CONCLUSION: This in vitro study demonstrates the anticancer activity of resveratrol against human fibrosarcoma cells. These results provide experimental support for in vivo trials assessing the effect of the natural polyphenol resveratrol.

Pro­apoptotic effects of pycnogenol on HT1080 human fibrosarcoma cells.

Complete surgical resection with clear margins remains the mainstay of therapy for localised fibrosarcomas. Nevertheless, metastatic fibrosarcomas still represent a therapeutic dilemma. Commonly used chemotherapeutic agents like doxorubicin have proven to be effective in <30% of all cases of disseminated fibrosarcoma. Especially elderly patients with cardiac subdisease are not suitable for systemic chemotherapy with doxorubicin. Therefore we tested the apoptotic effects of the well-tolerated pine bark extract pycnogenol and its constituents on human fibrosarcoma cells (HT1080). Ten healthy subjects (six females, four males, mean age 24.8 ± 6 years) received a single dose of 300 mg pycnogenol orally. Blood plasma samples were obtained before and 6 h after intake of pycnogenol. HT1080 cells were treated with these plasma samples. Additionally, HT1080 were incubated separately with catechin, epicatechin and taxifolin that are known as the main constituents of pycnogenol. Vital, apoptotic and necrotic cells were quantified using flow cytometric analysis. Gene expression was analyzed by RNA microarray. The results showed that single application of taxifolin, catechin and epicatechin reduced cell viability of HT1080 cells only moderately. A single dose of 300 mg pycnogenol given to 10 healthy adults produced plasma samples that led to significant apoptotic cell death ex vivo whereas pycnogenol-negative serum displayed no apoptotic activity. Microarray analysis revealed remarkable expression changes induced by pycnogenol in a variety of genes, which are involved in different apoptotic pathways of cancer cells [Janus kinase 1 (JAK1), DUSP1, RHOA, laminin γ1 (LAMC1), fibronectin 1 (FN1), catenin α1 (CTNNA1), ITGB1]. In conclusion, metabolised pycnogenol induces apoptosis in human fibrosarcoma cells. Pycnogenol exhibits its pro-apoptotic activity as a mixture and is more effective than its main constituents catechin, epicatechin and taxifolin indicating that the metabolised components interact synergistically. These results provide experimental support for in vivo trials assessing the effect of the pine bark extract pycnogenol.

Tendon transfers for drop foot correction: long-term results including quality of life assessment, and dynamometric and pedobarographic measurements.

BACKGROUND: Drop foot deformity is a common problem with severe restrictions in quality of life and impairment of daily activities. A technique of posterior tibial tendon transfer through the interosseus membrane and fixation to the anterior tibial and the long peroneal tendon "Bridle procedure" (stirrup-plasty) offers a physiological alternative to surgical correction. METHODS: Data of 53 consecutive patients treated by stirrup-plasty were acquired from patient's charts; 31 were interviewed with standardized questionnaires; 20 were examined physically; 19 received pedobarography, and 8 underwent dynamometric muscle function tests. Follow-up time averaged 6.5 years. RESULTS: The mean range of motion (ROM) in the ankle joint was 8° dorsiflexion and 15° plantar flexion. Most patients achieved plantigrade foot position and the majority developed gait without orthotic devices. As expected, maximum dorsiflexion torque averaged a third of the non-operated leg, according to reduced muscle diameter and strength of the transferred muscle. Pressure distribution of the sole during gait was not relevantly altered by the tendon transfer compared to the non-operated leg. Most patients were satisfied with the operative results and reported a significant increase in quality of life. CONCLUSIONS: Fusion of the transposed posterior tibial, anterior tibial and the peroneus longus tendon prevents drop foot deformity sufficiently. The stirrup mechanism, in combination with tenodesis of the toe extensors, provides a balanced foot and avoids equinovarus and cavus deformity without immobilizing the ankle joint. Improvements in quality of life parameters justify the risk of the operative procedure for the patient.

Synergistic apoptotic effects of taurolidine and TRAIL on squamous carcinoma cells of the esophagus.

The treatment of choice for esophageal cancer is considered surgical resection, but a median survival of around 20 months after treatment is still discouraging. The value of adjuvant or neoadjuvant radiation or chemotherapy is limited and to date, benefits have only been described for certain tumor stages. Therefore, new therapeutic options are required. As alternative chemotherapeutics, we tested the antibiotic taurolidine (TRD) on KYSE 270 human esophageal carcinoma cells alone and in combination with rhTRAIL (TNF related apoptosis-inducing ligand). Viability, apoptosis and necrosis were visualized by TUNEL assay and quantitated by FACS analysis. Gene expression was analysed by RNA microarray. The most effective concentration of TRD as single substance (250 micromol/l) induced apoptosis to a maximum of 40% after 12-h dose dependently, leaving 4% viable cells after 48 h; by comparison, rhTRAIL did not have a significant effect. The combination of both substances doubled the effect of TRD alone. Gene expression profiling revealed that TRD downregulated endogenous TRAIL, TNFRSF1A, TRADD, TNFRSF1B, TNFRSF21, FADD, as well as MAP2K4, JAK2 and Bcl2, Bcl2l1, APAF1 and caspase-3. TNFRSF25, cytochrome-c, caspase-1, -8, -9, JUN, GADD45A and NFKBIA were upregulated. TRAIL reduced endogenous TRAIL, Bcl2l1 and caspase-1 expression. BIRC2, BIRC3, TNFAIP3, and NFKBIA were upregulated. The combined substances upregulated endogenous TRAIL, NFKBIA and JUN, whereas DFFA and TRAF3 were downregulated compared to TRD as single substance. We conclude that TRD overcomes TRAIL resistance in KYSE 270 cells. Synergistic effects are dependent on the same and on distinct apoptotic pathways which, jointly triggered, result in an amplified response. Several apoptotic pathways, including the TNF-receptor associated and the mitochondrial pathway, were differentially regulated by the substances on gene expression level. Additionally transcription factors seem to be influenced, NFKB in particular. Endogenous TRAIL expression is increased by the combination of substances, whereas it is reduced by each single substance. Taking into consideration that the non-toxic TRD was able to reduce rhTRAIL toxicity and dose, combined therapy with TRD and rhTRAIL may offer new options for treatment in esophageal cancer.