Cardiac Troponins for the Clinical Management of Patients with Claudication and without Cardiac Symptoms.

Many patients with peripheral arterial disease (PAD) exhibit undiagnosed obstructive coronary artery disease. We aim to identify the patients with lifestyle limiting claudication due to PAD and without cardiac symptoms, requiring coronary revascularization based on high-sensitive troponin T (hsTnT) values. We assessed hsTnT in consecutive patients referred for elective endovascular treatment due to claudication [Rutherford categories (RC) 2 & 3] between January 2018 and December 2021. Diagnostic work-up by non-invasive imaging and, if required, cardiac catheterization was performed according to clinical data, ECG findings and baseline hsTnT. The occurrence of cardiac death, myocardial infarction or urgent revascularization during follow-up was the primary endpoint. Of 346 patients, 14 (4.0%) exhibited elevated hsTnT ≥ 14 ng/L, including 7 (2.0%) with acute myocardial injury by serial hsTnT sampling. Coronary revascularization by percutaneous coronary intervention was necessary in 6 of 332 (1.5%) patients with normal versus nine of 14 (64.3%) patients with elevated hsTnT (p < 0.001). During 2.4 ± 1.4 years of follow-up, 20 of 286 (7.0%) patients with normal versus four of 13 (30.8%) with elevated hsTnT at baseline reached the composite primary endpoint (p = 0.03 by log-rank test). In conclusion, elevated troponins in cardiac asymptomatic patients with claudication modify subsequent cardiac management and may increase the need for closer surveillance and more aggressive conservative management in polyvascular disease.

Phoenix atherectomy for patients with peripheral artery disease.

BACKGROUND: Endovascular atherectomy enables minimally invasive plaque removal in peripheral artery disease (PAD). AIMS: We aimed to evaluate the safety and the long-term effectiveness of the Phoenix atherectomy for the treatment of complex and calcified lesions in PAD patients. METHODS: Consecutive all-comer patients with PAD underwent the Phoenix atherectomy. Device safety in terms of perforation and distal embolisation were evaluated. Lesion calcifications were categorised by the Peripheral Arterial Calcium Scoring System (PACSS) and lesion complexity was assessed by the Transatlantic Inter-Society Consensus (TASC). Clinically driven target lesion revascularisation (TLR) was assessed. RESULTS: A total of 558 lesions were treated in 402 consecutive patients. Clinical follow-up was available at 15.7±10.2 months for 365 (91%) patients. Of 402 patients, 135 (33.6%) had claudication, 37 (9.2%) had ischaemic rest pain and 230 (57%) exhibited ischaemic ulcerations. Lesions were mostly identified in the femoropopliteal segments (55%), followed by below-the-knee (BTK) segments (32%). Complex TASC C/D lesions and moderate to severe calcifications (PACSS score ≥2) were present in 331 (82%) and 323 (80%) patients, respectively. The mean lesion length was 20.6±14.3 cm. Five (1%) perforations and 10 (2%) asymptomatic embolisations occurred. Bail-out stenting was performed in 4%, 16% and 3% of patients with common femoral artery, femoropopliteal and BTK lesions, respectively. During follow-up, 5 (3.9%) patients with claudication and 52 (21.9%) patients with critical limb-threatening ischaemia (CLTI) died (hazard ratio [HR] 3.7; p<0.001). Freedom from TLR was 87.5% (112 of 128) in patients with claudication and 82.3% (195 of 237) in patients with CLTI, respectively (HR 1.8; p=0.03). CONCLUSIONS: The Phoenix atherectomy can be safely performed in patients with complex lesions with a relatively low rate of bail-out stenting and clinically acceptable TLR rates. GERMAN CLINICAL TRIALS REGISTER: DRKS00016708.

Safety and effectiveness of Phoenix atherectomy for endovascular treatment in calcified common femoral artery lesions.

Background: Traditionally endarterectomy has been considered as the gold standard technique for the treatment of common femoral artery (CFA) lesions. The aim of this study is to investigate the procedural safety and mid-term outcomes of minimal invasive Phoenix atherectomy for the treatment of CFA lesions. Patients and methods: Phoenix atherectomy was used for treatment of 61 consecutive, moderately to heavily calcified CFA lesions in 56 patients. Lesions were classified based on the CFA occlusive disease classification (Type I, II&III lesions). Primary endpoints were technical, procedural, and clinical success rate. Safety endpoints (vessel perforation, peripheral embolization) and clinically driven target lesion revascularization (TLR) were also assessed. Results: Of 61 CFA lesions, 58 (95%) exhibited at least moderate/severe calcification (PACSS3 in 38 (62%) and PACSS4 in 20 (33%) cases). Type III lesions were present in 30 (49%), type I/II lesions in 31 (51%) cases. Technical and procedural success was achieved in 30 (49%) and all 61 (100%) lesions, respectively with low complication rates (0% perforation, 2% embolization). Adjunctive treatment after atherectomy was performed using drug-coated balloon (DCB) in 35 (57%) and bail-out stenting in 6 (10%) cases. Target lesion revascularization (TLR) occurred in 4 (7%) cases during a mean follow-up duration of 11±7months. All patients exhibited clinical improvement at follow-up, showing mean Rutherford category reduction from 3.7±1.1 to 1.5±1.1 (p<0.001). Conclusions: The Phoenix device can be used for the effective endovascular treatment of CFA lesions, due to its reasonable safety profile and mid-term results.

Exercises and Skin Physiology During International Space Station Expeditions.

BACKGROUND: The first skin physiological pilot experiment (SkinA) on a single astronaut showed a deterioration of the skin. In a follow-up experiment (SkinB) we showed that skin physiological parameters improved on average. However, it is well known that sports have positive effects on the skin, that astronauts prefer special sports devices, and do sports with different intensity. The aim of this study was to analyze the different sports activities of SkinB astronauts and to find out whether they have an influence on the skin physiological parameters.METHODS: The cumulative distance covered on the treadmill and on the cycle ergometer as well as the repetition of arm-related exercises have been calculated and possible correlation between sports activities and skin physiological parameters have been analyzed.RESULTS: The average distance covered for all six astronauts per day is 1364 AU on the treadmill T2, and 11,077 AU on the cycle ergometer CEVIS. In addition, the astronauts performed an average of about 73 repetitions of all arm-related exercises daily. Here, we were able to show very well how differently the astronauts on the ISS train. In addition, a decreasing trend in skin volume can be observed in astronauts with increasing activity on the bicycle and more repetitions on arm-related exercises.CONCLUSION: Increased activity on the cycle ergometer and increased arm-related exercises have a medium negative impact on the parameter skin volume and thus reflects more fluid content in the skin. No correlations between sports activities and skin moisture/skin barrier function could be found.Braun N, Hunsdieck B, Theek C, Ickstadt K, Heinrich U. Exercises and skin physiology during International Space Station expeditions. Aerosp Med Hum Perform. 2021; 92(3):160166.

Safety, effectiveness and mid-term follow-up in 136 consecutive patients with moderate to severely calcified lesions undergoing phoenix atherectomy.

To investigate the safety and effectiveness of the Phoenix atherectomy device for the treatment of complex and calcified lesions in patients with peripheral artery disease (PAD). 136 consecutive all-comer patients with chronic PAD underwent Phoenix atherectomy. Safety in terms of vessel injury and embolism, efficacy and clinical success in terms of ≥ 1Rutherford class (RF) improvement during follow-up were systematically analyzed. Lesion calcification was categorized by the Peripheral Arterial Calcium Scoring System (PACSS), whereas lesion complexity was classified by the Transatlantic Inter-Society Consensus (TASC). 151 lesions were treated in 136 consecutive patients. Clinical follow-up was available at 10.3 ± 4.2 months in 132 (97%) patients. 55 patients (40%) had intermittent claudication, 16 (12%) rest pain and 65 (48%) had ischemic ulcerations (mean RF class = 4.2 ± 1.1). 15 (11%) patients had TASC B lesions, whereas the majority 72 (53%) and 49 (36%) exhibited TASC C and D lesions, respectively. Mean PACSS score was 3.3 ± 0.9. Mean lesion length was 106 ± 92 mm. Atherectomy was combined with drug-coated balloon (DCB) in 129 (95%) patients. Nine (6.6%) patients with infra-inguinal lesions received stents. Technical and procedural success were recorded in 102 (75%) and 135 (99%), respectively. Perforation was noticed in 2 (1%), whereas asymptomatic embolism occurred in 6 (4%) patients. Clinical success was present in 54 (100%) patients with claudication and in 65 of 78 (83%) patients with critical limb ischemia (CLI). Atherectomy in combination with DCB angioplasty can be safely performed in patients with complex, calcified peripheral lesions with a relatively low rate of bail-out stenting and promising clinical mid-term results.German Clinical Trials Register: DRKS00016708.

The Influence of Short-Wave and Long-Wave Radiation Spectrum on the Photostability of Sunscreens.

BACKGROUND: Sunscreen products aim to help protect the skin against UV radiation and consequently reduce the risk of early skin ageing and skin cancer. However, it is well known that some sunscreen ingredients are not photostable, but this usually refers to irradiation with UV light. Moreover, it has to be mentioned that a relative cumulative erythema effectiveness compliant light source is used for the in vivo sun protection factor (SPF) testing. Here, UV simulators equipped with a xenon arc lamp use filters such as WG320 and UG11 (thickness 1 mm) to minimize infrared (IR) radiation and wavelength below 300 nm. However, under practical conditions, the sunscreen product is not only exposed to UVA/B light, but also to visible light (VIS) and IR light. In fact, the spectrum of solar radiation is composed of approximately 7% UV, 39% VIS and 54% IR. AIMS: To investigate the influence of short-wave and long-wave radiation on the photostability of sunscreens. METHODS: Irradiation was performed with the Suntest CPS+ that is considered to closely imitate solar radiation. The filter UG11 (thickness 1 mm), which absorbs much of the VIS and IR light, and the glass filter WG320 (thickness 2 mm), which effectively absorbs radiation of wavelengths less than 300 nm, were used in the Suntest CPS+ both individually and in combination and were inserted between the light source and the samples. The following transmission measurements were carried out with Labsphere's UV-2000s device. Here, the effectiveness (percentage change of SPF before irradiation to SPF after irradiation) as a measure of the photostability was calculated. RESULTS: As expected after total solar spectrum irradiation, the effectiveness in all tested sunscreens is lower compared to relative cumulative erythema effectiveness light used for in vitro testing of SPF. In the reference sunscreen formula S2 as well as in the two different sunscreen products, especially long-wave radiation (>400 nm) had an effect on photostability, whereas short-wave radiation had only a minor impact. In contrast, in the BASF sun care gel line only short-wave radiation below 300 nm had an effect on photostability, and blocking VIS and IR light had no effect at all. CONCLUSION: Based on these data, we can conclude that short waves and/or VIS + IR light have an influence on the photostability of sunscreens.

Surface Evaluation of Living Skin (SELS) parameter correlation analysis using data taken from astronauts working under extreme conditions of microgravity.

BACKGROUND: In space, due to fluid shift a 45% decrease in the skin topography parameter volume (mm3 ) was seen using the VisioScan® camera. Simultaneously, the parameters roughness, scaling and wrinkles changed dramatically as well. Thus, the present study has the objective to understand the relationship between the SELS parameters under extreme conditions and their application by addressing scientific-dermatological questions. MATERIAL AND METHODS: SELS measurements were performed on the volar forearms of six astronauts. The Pearson correlation coefficient was used to determine the association between the variables. RESULTS: A significant correlation was found between the skin topography parameter volume and the skin parameters roughness, scaling and wrinkles. A closer look at each astronaut revealed a significant correlation for all astronauts for the parameters volume and roughness and for more than 65% of the astronauts for the parameters volume and scaling and volume and wrinkles. However, no correlation could be found between the parameters skin hydration and roughness and scaling, respectively. CONCLUSION: Only the parameter skin volume leads to meaningful data under microgravity. Physiological changes observed by fluid shift are comparable to the skin condition edema on earth. Based on the obtained data, we can conclude that the formulas for the SELS parameters roughness, scaling and wrinkles for this special skin condition need to be reviewed.

Application of an Easy-to-Perform High-Energy and Low-End Visible Light Transmittance Method and the Influence of Tinted Sunscreens on High-Energy/Low-End Visible Light Transmittance and Infrared Protection.

BACKGROUND: About 50% of the sun's radiation arriving on earth is visible light (VIS). For a long time, its effects on human health have not been fully investigated. But recently, the influence of VIS has gained more attention, especially regarding skin physiology. Studies showed various effects, many of them harmful, comparable to UV radiation. As a result, there are now a few sunscreens commercially available which claim protection against VIS. The question of whether protection is necessary is still much discussed. AIMS: The objective of this study was to develop an easy-to-perform high-energy visible (HEV) and low-end visible (LEV) light transmittance method to determine the direct VIS protection of sunscreens and other cosmetic samples. Furthermore, the influence of the brightness of the tested products on the HEV, LEV, and infrared A protection was investigated. METHODS: An experimental setup consisting of a light source, a VIS-transmissible filter system, and a sensor unit was built to measure the direct VIS protection of sunscreens and other daily skin care products in two ranges of the VIS area. For a closer look, the brightness of the samples was evaluated by photometric assessment. RESULTS/CONCLUSION: The experimental setup could be validated. It could be demonstrated for the first time that there is a strong positive linear correlation between transmittance and brightness of tinted sunscreen and daily skin care products with sunscreen properties in the HEV, LEV, and infrared A range. However, tinted samples worked best in the blue light region, and the higher the wavelength range, the lower the protection.

Self-Reported Skin Changes by a Selected Number of Astronauts after Long-Duration Mission on ISS as Part of the Skin B Project.

BACKGROUND: One of the most challenging and important factors of manned space missions is to keep astronauts healthy on orbit. In a study on 46 ISS crew members who were on 6-month (average) missions, skin rashes were the most self-reported event. Furthermore, among notable events, 40% were classified as skin rashes/hypersensitivities. Thus, especially skin conditions during space travel are of major clinical interest and require further research. AIMS: The aim of the study was to determine skin conditions in space flight among US and European astronauts, especially taking into account the terrestrial skin conditions as well as on-orbit skin care habits. METHODS: A preflight questionnaire was given to the astronauts asking about their terrestrial skin care habits and skin conditions/atopy before launch. In addition, they were asked to fill out a postflight questionnaire asking about their on-orbit skin care routine and whether any special observations regarding the skin were made during flight. RESULTS: A total of 23 skin symptoms were recorded by 8 nonatopic astronauts (mean age: 41 years) during the mission. The symptoms were peeling (21.74%), rash (17.39%), dryness (13.04%), severe dryness (8.70%), reddening (8.70%), itchiness (8.70%), bruising (4.35%), skin sensitivity (4.34%), bumps (4.35%), acne (4.35%) and slow healing of contusions and lacerations (4.35%). Especially the hands and feet were affected by skin problems. As a result of this examination, it was shown that the skin symptoms correlate with poor hygiene on orbit, whereas the factor "environment" on the ISS plays a minor role. Surprisingly, 2 astronauts even experienced positive effects on their skin. CONCLUSION: Based on these preliminary data, it is important to pay more attention to skin hygiene and maintenance in space.

Current Data on Effects of Long-Term Missions on the International Space Station on Skin Physiological Parameters.

BACKGROUND: Skin reaction to spaceflight has not really been studied yet, although the skin has a very important barrier function to protect the body and can contribute to a more general understanding of physiology. It is proposed here to make a more thorough investigation of the skin during long-term spaceflight, using noninvasive techniques. AIMS: The aim of the present Skin-B study is to investigate the kinetics and range of possible skin modifications during long-duration spaceflights and their recovery. METHODS: In order to investigate the effect on skin physiological parameters during spaceflight, measurements were carried out on 6 astronauts with respect to skin hydration, transepidermal water loss/barrier function, and surface evaluation of the living skin in orbit. Additional measured parameters on the ground were skin elasticity, skin density and thickness, as well as microcirculation. RESULTS: Data from the Skin-B subjects (n = 6) contradict the results obtained in the previous pilot study SkinCare (n = 1 subject). In the present study, no deterioration of the skin was found but rather an improvement in skin hydration and skin barrier function, and no changes or improvement in the appearance of the skin surface. Furthermore, the skin density and skin thickness as well as skin elasticity values were unchanged from pre-flight values. CONCLUSION: In conclusion, we found that spaceflight under present conditions has no negative impact on skin physiological parameters.

Determination of the Influence of the Antiphlogistic Ingredients Panthenol and Bisabolol on the SPF Value in vivo.

BACKGROUND: Today, the sun protection factor (SPF) value of sunscreen products is determined in vivo with a standardized protocol (EN ISO 24444:2010), and the measured SPF biological end point is the visible skin erythema. However, many of the sunscreen products currently available on the market have antiphlogistic ingredients, which may potentially result in an overestimated SPF of the sunscreen. AIMS: To investigate the potential influence of the antiphlogistic ingredients panthenol and bisabolol in sunscreens on the determined SPF value in vivo. METHODS: Formulations with different concentrations of the antiphlogistic ingredients bisabolol or panthenol were tested. As a reference, a base formulation (vehicle) without antiphlogistic ingredients was used. First, the SPF of the sunscreen formulas with and without antiphlogistic ingredients was analyzed in vitro. To investigate whether the antiphlogistic ingredient may suppress the inflammatory response to ultraviolet (UV) irradiation, the SPF was determined in vivo. Finally, selected formulations were also analyzed in an erythema model for testing formulations on UV-induced inflammation. RESULTS: It could be confirmed that no differences between the formula with and that without the active antiphlogistic ingredients bisabolol or panthenol exist when measured in vitro. However, there was also no statistically significant difference in the erythemal response between the vehicle (without an antiphlogistic active ingredient) and the test formulations with different concentrations of the antiphlogistic active ingredients in the in vivo determination of the SPF. Evidence of anti-inflammatory activity of the sunscreen antiphlogistics bisabolol and panthenol was also not apparent in the UV model over a time course of 48 h. Conlusion: The antiphlogistic ingredients panthenol and bisabolol incorporated in the tested sunscreen formula do not interfere with erythema reddening and thus do not affect the SPF value in vivo.

Development of an in vitro Test Procedure to Determine the Direct Infrared A Protection of Sunscreens and Non-Cosmetic Samples.

BACKGROUND: Every day human skin is exposed to infrared A (IRA) radiation as part of the natural sun rays. As IRA radiation accounts for around one third of the solar radiation, it has gained great attention concerning its effects on the human body and skin. In the past few years it has been discussed controversially whether IRA radiation (of solar origin) is harmful or not. Nonetheless, there are several sunscreens on the German market that claim IRA protection for themselves. AIMS: The present study seeks to find an experimental set-up and a test procedure for the determination and quantification of direct IRA protection (realized via reflection or absorption of the IRA radiation), since to our knowledge these do not yet exist. METHODS: In this study we proved the usability of a set-up consisting of a light source, an IRA-transmissible filter system and a sensor unit, for the determination and quantification of the IRA protection of cosmetic and non-cosmetic samples. RESULTS/CONCLUSION: The applicability of the IRA emission of the light source, the spectral detector, transmissivity of the filter systems and the sample carriers could be validated. This experimental set-up can be used as an in vitro test procedure for the determination of direct IRA protection.

Effect of the multifunctional cosmetic ingredient sphinganine on hair loss in males and females with diffuse hair reduction.

Sphingolipids are well known to promote keratinocyte differentiation and to induce ceramide production. In addition, they show anti-inflammatory and antimicrobial activities. Thus, the aim of this study is to investigate the potential effect of sphinganine on prolonging the hair anagen rate and improving the overall hair quality and scalp health. The inhibitory potential of sphinganine toward 5-α-reductase was studied using an in vitro assay. The stimulation of the antimicrobial peptide HBD2 by sphinganine was measured by real-time polymerase chain reaction and immunostaining. Sphinganine bioavailability was studied ex vivo using a pig skin model. A placebo-controlled, double-blind study was designed to evaluate the efficacy of sphinganine on hair loss and hair/scalp quality in vivo. In vitro results showed that sphinganine is a potent inhibitor of 5-α-reductase type I that prevents the conversion of testosterone to dihydrotestosterone, a key factor of androgenetic male baldness. In vivo results demonstrated efficacy in reducing non-illness-related hair loss among males. In terms of expert rating, all hair quality and scalp parameters improved after application of sphinganine. Improved scalp health might be linked to the observed increase of the antimicrobial peptide HBD2. Thus, sphinganine is well suited as a topical alternative for the improvement of scalp health and hair quality and anti-hair loss application.

[Mesembryanthemum crystallinum L. as dermatologically effective medicinal plant - first results from 3 pilot studies]. / Mesembryanthemum crystallinum L. als dermatologisch wirksame Heilpflanze - erste Ergebnisse aus 3 Pilotstudien.

BACKGROUND: Apart from well-known medical plants of rational phytotherapy there is a variety of plants, such as Mesembryanthemum crystallinum L., whose potential effects are not examined sufficiently to date. Therefore, in 3 pilot studies we investigated the dermatological effect of an extract of M. crystallinum (Mesem Cream). MATERIALS AND METHODS: In a retrospective user survey and a pre-post study with 6 persons in a wheelchair the efficacy profile of Mesem Cream was investigated. In a third placebo-controlled pilot study changes in skin hydration was measured using corneometer measurement in 6 healthy volunteers with dry skin. RESULTS: Compared to untreated skin, corneometer measurement revealed a significant increase of skin hydration with Mesem Cream (25.8 ± 5.8 pre to 46.6 ± 9.2 post treatment vs. 26.3 ± 6.0 pre to 33.8 ± 6.0 post treatment) as well as a statistical trend (p=0.11; t-Test) compared to basic cream (25.1 ± 4.7 pre to 41.9 ± 7.3 post treatment). Improvement in skin hydration was also found in 17 of 29 survey participants. Further, the volunteers in the wheelchair showed significant improvements in their subjectively rated skin softness and hydration level. CONCLUSION: These pilot studies investigated skin hydrating effects of the traditional medical plant M. crystallinum. Although the results were promising, they have to be interpreted with caution in particular due to low sample size. Further, study design should be more clear-cut and focus skin hydration as a main outcome parameter in more detail.

Sebusuppressive efficacy of the antioxidant bis-ethylhexyl hydroxydimethoxy benzylmalonate in the treatment of oily and blemished skin.

The aim of this study was to assess the effect of 2% bis-ethylhexyl hydroxydimethoxy benzylmalonate (HDBM; RonaCare(®) AP) as an active ingredient in the treatment of oily and blemished skin. This study was carried out as a randomized, placebo-controlled, single-blind study on 44 test subjects with blemished skin over a period of 8 weeks. Sebum measurement, skin inflammation/redness scoring by an expert, photographic documentation and a self-assessment with regard to skin improvement, and tests of skin compatibility and galenic characteristics were performed. Treatment with 2% HDBM resulted in a significant reduction of sebum excretion and showed efficacy against inflamed/red lesions also shown by photographic documentation. Efficacy and galenic performance of 2% HDBM were judged to be superior to the placebo emulsion. Additionally, 2% HDBM was well tolerated; approximately 80% of the test subjects rated the compatibility as good to very good.

Green tea polyphenols provide photoprotection, increase microcirculation, and modulate skin properties of women.

Dietary constituents including polyphenols and carotenoids contribute to endogenous photoprotection and modulate skin characteristics related to structure and function of the tissue. Animal and in-vitro studies indicate that green tea polyphenols affect skin properties. In a 12-wk, double-blind, placebo-controlled study, 60 female volunteers were randomized to an intervention or control group. Participants consumed either a beverage with green tea polyphenols providing 1402 mg total catechins/d or a control beverage. Skin photoprotection, structure, and function were measured at baseline (wk 0), wk 6, and wk 12. Following exposure of the skin areas to 1.25 minimal erythemal dose of radiation from a solar simulator, UV-induced erythema decreased significantly in the intervention group by 16 and 25% after 6 and 12 wk, respectively. Skin structural characteristics that were positively affected included elasticity, roughness, scaling, density, and water homeostasis. Intake of the green tea polyphenol beverage for 12 wk increased blood flow and oxygen delivery to the skin. Likewise, in a separate, randomized, double-blind, single-dose (0.5, 1.0, and 2.0 g) study of green tea polyphenols, blood flow was maximized at 30 min after ingestion. In summary, green tea polyphenols delivered in a beverage were shown to protect skin against harmful UV radiation and helped to improve overall skin quality of women.

Absorption spectra of human skin in vivo in the ultraviolet wavelength range measured by optoacoustics.

Knowledge of the optical properties of human skin in the ultraviolet range is fundamental for photobiologic research. However, optical properties of human skin in the ultraviolet spectral range have so far mainly been measured ex vivo. We have determined the absorption spectra of human skin in vivo in the wavelength range from 290 to 341 nm in 3 nm steps using laser optoacoustics. In this technique, optical properties are derived from the pressure profile generated by absorbed light energy in the sample. In a study on 20 subjects belonging to phototypes I-IV, we studied the optical properties at the volar and dorsal aspect of the forearm as well as on the thenar. Analysis of the measured absorption spectra shows that comparable skin areas-like different sides of the forearm-have qualitatively similar optical characteristics. Still, the optical properties may vary substantially within the same area, probably due to the skin structure and inhomogeneities. Comparison of the spectra from different skin sites indicates that the spectral characteristics of the stratum corneum and its chromophores play an important role for the optical properties of human skin in vivo in the ultraviolet B range.

Intervention with flaxseed and borage oil supplements modulates skin condition in women.

Ingestion of selected nutrients modulates dermal properties. In the present study, two groups of women ingested flaxseed or borage oil for 12 weeks. The control group received a placebo containing medium-chain fatty acids. Dose was 2.2 g total fatty acids/d with alpha-linolenic acid and linoleic acid as major constituents in the flaxseed oil group; in the borage oil group linoleic and gamma-linolenic acid were predominant. In the flaxseed oil group, the contribution of alpha-linolenic acid to total fatty acids in plasma was significantly increased on weeks 6 and 12, whereas there was an increase in gamma-linolenic acid in the borage oil group (P < 0.05). Skin irritation was performed by nicotinate treatment, and changes in skin reddening and blood flow were monitored. Compared to week 0, skin reddening was diminished in both groups; blood flow was also lowered. Skin hydration was significantly increased after 12 weeks of treatment compared to week 0, with flaxseed or borage oil (P < 0.05). Transepidermal water loss was decreased in both oil groups by about 10 % after 6 weeks of supplementation. A further decrease was determined after 12 weeks in the flaxseed oil group. Surface evaluation of living skin revealed that roughness and scaling of the skin were significantly decreased with flaxseed and borage oil comparing week 0 and week 12 (P < 0.05). Except for hydration, none of the parameters was affected in the placebo group. The present data provide evidence that skin properties can be modulated by an intervention with dietary lipids.

Wavelength-dependent penetration depths of ultraviolet radiation in human skin.

The wavelength-dependent penetration depth of ultraviolet radiation in human skin is a fundamental parameter for the estimation of the possible photobiological impact of ultraviolet (UV) radiation. We have determined the absorption spectra of human skin in vivo in the wavelength range from 290 to 341 nm in 3-nm steps using laser optoacoustics and calculated the respective penetration depths. Data were analyzed with respect to different skin regions and skin phototype of the 20 subjects in the study (phototype I: n=3; II: n=7; III: n=5; IV: n=5), revealing large variability between individuals. The penetration depth of UV radiation in human skin is highly dependent on wavelength and skin area, but no significant dependence on skin phototype could be found.