Visualizing intra-medulla lipids in human hair using ultra-multiplex CARS, SHG, and THG microscopy.

We performed label-free imaging of human-hair medulla using multi-modal nonlinear optical microscopy. Intra-medulla lipids (IMLs) were clearly visualized by ultra-multiplex coherent anti-Stokes Raman scattering (CARS) spectroscopic imaging. Two groups of IMLs were found: second harmonic generation (SHG) active and inactive. By combining SHG analysis with CARS, the two groups were identified as free fatty acids and wax esters, respectively.

Near-infrared imaging of water in human hair.

BACKGROUND/PURPOSE: The water content of hair can be evaluated by weighing, the Karl Fischer method, and from electrical properties. However, these methods cannot be used to study the distribution of water in the hair. Imaging techniques are required for this purpose. In this study, a highly sensitive near-infrared (NIR) imaging system was developed for evaluating water in human hair. The results obtained from NIR imaging and conventional methods were compared. METHODS: An extended indium-gallium-arsenide NIR camera (detection range: 1100-2200 nm) and diffuse illumination unit developed in our laboratory were used to obtain a NIR image of hair. A water image was obtained using a 1950-nm interference filter and polarization filter. Changes in the hair water content with relative humidity (20-95% RH) and after immersion in a 7% (w/w) sorbitol solution were measured using the NIR camera and an insulation resistance tester. The changes in the water content after treatment with two types of commercially available shampoo were also measured using the NIR camera. RESULTS: As the water content increased with changes in the relative humidity, the brightness of the water image decreased and the insulation resistance decreased. The brightness in the NIR image of hair treated with sorbitol solution was lower than that in the image of hair treated with water. This shows the sorbitol-treated hair contains more water than water-treated hair. The sorbitol-treated hair had a lower resistance after treatment than before, which also shows that sorbitol treatment increases the water content. With this system, we could detect a difference in the moisturizing effect between two commercially available shampoos. CONCLUSION: The highly sensitive imaging system could be used to study water in human hair. Changes in the water content of hair depended on the relative humidity and treatment with moisturizer. The results obtained using the NIR imaging system were similar to those obtained using a conventional method. Our system could detect differences in the moisturizing effects of two commercially available shampoos.

A missense mutation within the helix initiation motif of the keratin K71 gene underlies autosomal dominant woolly hair/hypotrichosis.

Woolly hair (WH) is an abnormal variant of tightly curled hair, which is frequently associated with hypotrichosis. Non-syndromic forms of WH can show either autosomal-dominant WH (ADWH) or autosomal-recessive WH (ARWH) inheritance patterns. ARWH has recently been shown to be caused by mutations in either the lysophosphatidic acid receptor 6 (LPAR6) or lipase H (LIPH) gene. More recently, a mutation in the keratin K74 (KRT74) gene has been reported to underlie ADWH. Importantly, all of these genes are abundantly expressed in the inner root sheath (IRS) of human hair follicles. Besides these findings, the molecular mechanisms underlying hereditary WH have not been fully disclosed. In this study, we identified a Japanese family with ADWH and associated hypotrichosis. After exclusion of known causative genes, we discovered the heterozygous mutation c.422T>G (p.Phe141Cys) within the helix initiation motif of the IRS-specific keratin K71 (KRT71) gene in affected family members. We demonstrated that the mutant K71 protein led to disruption of keratin intermediate filament formation in cultured cells. To our knowledge, it is previously unreported that the KRT71 mutation is associated with a hereditary hair disorder in humans. Our findings further underscore the crucial role of the IRS-specific keratins in hair follicle development and hair growth in humans.

Acrolein toxicity: Comparison with reactive oxygen species.

The toxicity of acrolein was compared with that of reactive oxygen species using a mouse mammary carcinoma FM3A cell culture system. Complete inhibition of cell growth was accomplished with 10 microM acrolein, 100 microM H(2)O(2), and 20 microM H(2)O(2) plus 1mM vitamin C, which produce ()OH, suggesting that toxicity of acrolein is more severe than H(2)O(2) and nearly equal to that of ()OH, when these compounds were added extracellularly. Acrolein toxicity was prevented by N-acetyl-l-cysteine and N-benzylhydroxylamine, and attenuated by putrescine and spermidine. Toxicity of H(2)O(2) was prevented by glutathione peroxidase plus N-acetyl-l-cysteine, pyruvate, catalase, and reduced by polyphenol, and toxicity of ()OH was prevented by glutathione peroxidase plus N-acetyl-l-cysteine, pyruvate, catalase and reduced by N-acetyl-l-cysteine. The results indicate that prevention of cell toxicity by N-acetyl-l-cysteine was more effective with acrolein than with ()OH. Protein and DNA synthesis was damaged primarily by acrolein and reactive oxygen species, respectively.