Substantial experimental evidence indicates that the hormonal form of vitamin D promotes the differentiation and inhibits the proliferation, invasiveness, and metastasis of human prostatic cancer cells. Results from epidemiologic studies of vitamin D status and/or vitamin D receptor (VDR) polymorphisms and prostate cancer risk have been mixed. We conducted a population-based, case-control study of advanced prostate cancer among men ages 40 to 79 years from the San Francisco Bay area. Interview data on lifetime sun exposure and other risk factors were collected for 905 non-Hispanic White men (450 cases and 455 controls). Using a reflectometer, we measured constitutive skin pigmentation on the upper underarm (a sun-protected site) and facultative pigmentation on the forehead (a sun-exposed site) and calculated a sun exposure index from these measurements. Biospecimens were collected for 426 cases and 440 controls. Genotyping was done for VDR polymorphisms in the 5' regulatory region (Cdx-2), exon 2 (FokI), and the 3' region (TaqI and BglI). Reduced risk of advanced prostate cancer was associated with high sun exposure determined by reflectometry [odds ratio (OR), 0.51; 95% confidence interval (95% CI), 0.33-0.80] and high occupational outdoor activity (OR, 0.73; 95% CI, 0.48-1.11). Significant risk reductions with the high-activity alleles FokI FF or Ff, TaqI tt, and BglI BB genotypes and a nonsignificant reduction with Cdx-2 AG or AA genotype were observed in the presence of high sun exposure, with ORs ranging from 0.46 to 0.67. Our findings support the hypothesis that sun exposure and VDR polymorphisms together play important roles in the etiology of prostate cancer.

https://cancerres.aacrjournals.org/content/canres/65/12/5470.full.pdf

Sun exposure, vitamin D receptor gene polymorphisms, and risk of advanced prostate cancer.

Objective in situ measurements of skin pigmentation are needed for accurate documentation of pigmentation disorders, in studies of constitutive and induced skin pigmentation, for testing of the efficacy of pro-pigmentation or de-pigmentation agents, etc. Non-invasive instrumental measurements of skin pigmentation have been used for many decades. All are based on the ability of melanin to attenuate light. However, hemoglobin in dermal capillaries also attenuates light and needs to be accounted for when pigmentation is assessed. The methods under consideration include: (a) single point measurements, in which light reflected from a defined skin area is collected and a pigment index is calculated representing the average pigmentation over the examined area, and (b) imaging methods that attempt to generate a concentration distribution map of melanin pigment for the skin area being imaged. In this article, we describe the potentials and the limitations of the different approaches to both single point and imaging methods.

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1600-0749.2004.00204.x

Non-invasive measurements of skin pigmentation in situ.

BACKGROUND Pigment lasers have been used in melasma with unsatisfactory results.



OBJECTIVE To determine the effectiveness and safety of 1,064-nm Q-switched neodymium-doped yttrium aluminum garnet (QS-Nd:YAG) laser treatment of melasma in Asians.



MATERIALS AND METHODS Split-face randomized study comparing combination QS-Nd:YAG laser and 2% hydroquinone with topical treatment in dermal or mixed-type melasma. Twenty-two patients were treated with 1,064-nm QS-Nd:YAG laser, 6-mm spot size, 3.0- to 3.8-J/cm2 fluence for five sessions at 1-week intervals. Pigmentation was objectively recorded using a colorimeter (lightness index score), and subjective assessments were evaluated using the modified Melasma Area and Severity Index (mMASI) score.



RESULTS After five laser treatments, statistically significant improvement of melasma from baseline was observed in colorimeter (p<.001) and mMASI score (p<.001) on the laser side. The laser side achieved an average 92.5% improvement in relative lightness index and 75.9% improvement in mMASI, compared with 19.7% and 24%, respectively, on the control side (p<.001). Mottled hypopigmentation developed in three patients. During follow-up, four of 22 patients developed rebound hyperpigmentation, and all patients had recurrence of melasma.



CONCLUSION QS-Nd:YAG laser treatment for melasma in Asians produced only temporary improvement and had side effects. Common complications were hypopigmentation, melasma recurrence, and rebound hyperpigmentation.



The authors have indicated no significant interest with commercial supporters.

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1524-4725.2009.01383.x

Low‐Fluence Q‐Switched Neodymium‐Doped Yttrium Aluminum Garnet (1,064 nm) Laser for the Treatment of Facial Melasma in Asians

Radiation dermatitis occurs in approximately 95% of patients receiving radiotherapy (RT) for breast cancer. We conducted a randomized, double-blind, placebo-controlled clinical trial to assess the ability of curcumin to reduce radiation dermatitis severity in 30 breast cancer patients. Eligible patients were adult females with noninflammatory breast cancer or carcinoma in situ prescribed RT without concurrent chemotherapy. Randomized patients took 2.0 grams of curcumin or placebo orally three times per day (i.e., 6.0 grams daily) throughout their course of RT. Weekly assessments included Radiation Dermatitis Severity (RDS) score, presence of moist desquamation, redness measurement, McGill Pain Questionnaire-Short Form and Symptom Inventory questionnaire. The 30 evaluable patients were primarily white (90%) and had a mean age of 58.1 years. Standard pooled variances t test showed that curcumin reduced RDS at end of treatment compared to placebo (mean RDS = 2.6 vs. 3.4; P = 0.008). Fisher's exact test revealed that fewer curcumin-treated patients had moist desquamation (28.6% vs. 87.5%; P = 0.002). No significant differences were observed between arms for demographics, compliance, radiation skin dose, redness, pain or symptoms. In conclusion, oral curcumin, 6.0 g daily during radiotherapy, reduced the severity of radiation dermatitis in breast cancer patients.

/pdf/curcumin-for-radiation-dermatitis-a-randomized-double-blind-3xp4khmb7n.pdf

Curcumin for Radiation Dermatitis: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial of Thirty Breast Cancer Patients

The plant cuticle consists of cutin, a polyester of glycerol, hydroxyl, and epoxy fatty acids, covered and filled by waxes. While the biosynthesis of cutin building blocks is well documented, the mechanisms underlining their extracellular deposition remain unknown. Among the proteins extracted from dewaxed tomato (Solanum lycopersicum) peels, we identified GDSL1, a member of the GDSL esterase/acylhydrolase family of plant proteins. GDSL1 is strongly expressed in the epidermis of growing fruit. In GDSL1-silenced tomato lines, we observed a significant reduction in fruit cuticle thickness and a decrease in cutin monomer content proportional to the level of GDSL1 silencing. A significant decrease of wax load was observed only for cuticles of the severely silenced transgenic line. Fourier transform infrared (FTIR) analysis of isolated cutins revealed a reduction in cutin density in silenced lines. Indeed, FTIR-attenuated total reflectance spectroscopy and atomic force microscopy imaging showed that drastic GDSL1 silencing leads to a reduction in ester bond cross-links and to the appearance of nanopores in tomato cutins. Furthermore, immunolabeling experiments attested that GDSL1 is essentially entrapped in the cuticle proper and cuticle layer. These results suggest that GDSL1 is specifically involved in the extracellular deposition of the cutin polyester in the tomato fruit cuticle.

Tomato GDSL1 Is Required for Cutin Deposition in the Fruit Cuticle

BACKGROUND/AIMS: Two types of skin reflectance instruments are available nowadays for the determination of skin color: a tristumulus colorimeter (Chromameter from Minolta) using the CIE L*a*b* color system and the narrow-band simple reflectance meters (DermaSpectrometer from Cortex and Mexameter from Courage-Khazaka) using the erythema/melanin indices. The purpose of this study was to compare the capabilities of the three instruments (sensitivity, repeatability and correlation) in vitro and in vivo. METHODS: Comparative color measurements were carried out first in vitro on standardized color charts and subsequently in vivo on different skin areas in human volunteers. Skin color changes induced by various physico-chemical treatments were also quantitatively evaluated with the three instruments. RESULTS: The in vitro and in vivo repeatabilty as well as the sensitivity of the three instruments are rather good. Erythema and skin blanching could be readily quantified by the increase of the a* parameter and of the erythema indices of the simple reflectance meters. Natural UV tanning and artificial chemical tanning could be measured by the decrease of L* and increase of b* and of the melanin indices. CONCLUSION: The Chromameter and the two narrow-band reflectance instruments were able to characterize skin color and to quantify small skin color changes. Moderate to high significant linear correlations could be established between the CIE L*a*b* color parameters and the erythema/melanin indices.

Skin color measurements: comparison between three instruments: the Chromameter®, the DermaSpectrometer® and the Mexameter®

Background/aims: It was the aim of this study to carry out a comparative evaluation in vitro on standardized color charts and in vivo on healthy subjects using the Visi-Chroma VC-100®, a new imaging tristimulus colorimeter and the Minolta Chromameter CR-200® as a reference instrument. The Visi-Chroma combines tristimulus color analysis with full color visualization of the skin area measured. The technical performances of both instruments were compared with the purpose of validating the use of this new imaging colorimeter in dermatocosmetic research. Methods: In vitro L*a*b* color parameters were taken with both instruments on standardized color charts (Macbeth and RAL charts) in order to evaluate accuracy, sensitivity range and repeatability. These measurements were completed by in vivo studies on different sites of human skin and studies of color changes induced by topical chemical agents on forearm skin. The accuracy, sensitivity range and repeatability of measurements of selected distances and surfaces in the measuring zone considered and specific color determinations of specific skin zones were also determined. Results: The technical performance of this imaging colorimeter was rather good, with low coefficients of variation for repeatability of in vitro and vivo color measurements. High positive correlations were established in vitro and in vivo over a wide range of color measurements. The imaging colorimeter was able to measure the L*a*b* color parameters of specific chosen parts of the skin area considered and to measure accurately selected distances and surfaces in the same skin site considered. Conclusion: These comparative measurements show that both instruments have very similar technical performances and that high levels of correlation were obtained in vitro and in vivo using the L*a*b* color parameters. In addition, the Visi-Chroma presents the following improvements: 1) direct visualization and recording of the skin area considered with concomitant color measurements; 2) determination of the specific color parameters of skin areas chosen in the total measuring area; and 3) accurate determination of selected distances and surfaces in the same skin areas chosen.

Katrien K. Alewaeters

Papers

Skin color measurements: comparison between three instruments: the Chromameter®, the DermaSpectrometer® and the Mexameter®

The Visi-Chroma VC-100: a new imaging colorimeter for dermatocosmetic research.