The cooking of oil-containing food products at high temperatures results in an insoluble, unsightly, greasy layer of grime on appliance surfaces in residential and commercial kitchens. Over time, adsorbed grime becomes difficult to remove using normal dishwashing detergents. A number of studies have focused on the deterioration and oxidation of oils and the harmful effects that volatile compounds associated with such processes have on human health. Little attention, however, has been paid to kitchen grime. The present study examined grime obtained from the surfaces of appliances such as sirocco fans, filters, and range hoods in residential kitchens in Tokyo. The grime was characterized by X-ray fluorescence spectroscopy (XRF), Fourier-transform infrared spectroscopy (FT-IR), size exclusion chromatography (SEC), thermal hydrolysis methylation-gas chromatographymass spectroscopy (THM-GCMS), and nuclear magnetic resonance (NMR) techniques. The chemical composition and structure of the grime differed from those of the edible oils. The grime consisted mainly of polymerized and oxidized triacylglycerols. Bridging between unsaturated acyl groups of triglycerols occurred through thermal oxidation and aging in air, yielding their dimers, trimers, and highly polymerized products while also transforming unsaturated acyl groups into saturated ones. Cross-linking reactions involving dibasic acids also caused polymerization. Those polymerized products strongly adhered to the hard surfaces of the appliances. Small amounts of cellulose fibers from air or towel may also play a role in mechanically stabilizing the dirt structure.

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Neurotrophin (NT)-4 is known to be an inducer of catagen in the hair cycle, but little is known of its role in the pathogenesis of androgenetic alopecia (AGA). We previously studied the gene expression of dermal papilla cells from AGA patients and controls and found that NT-4 was up-regulated in the AGA patients. In the present study, the etiological relationship between NT-4 and androgen, which is one of the causes of AGA, and the effect of an NT-4 inhibitor on hair growth were investigated. We established a NT-4 luciferase reporter assay system using a roughly 2-kb region upstream of the NT-4 transcriptional start site and investigated an accelerating effect of androgen on NT-4 transcription. We also screened for a NT-4 inhibitor by using the NT-4 reporter assay and evaluated the effects of NT-4 inhibitors on hair growth by using dihydrotestosterone (DHT)-implanted mice. The results show that transcriptional activity of NT-4 was accelerated by androgen, and extract of Hura crepitans L. inhibited the DHT-induced NT-4 transcriptional activation and ameliorated the retardation of hair regrowth by DHT-implanted mice. We also isolated the active ingredient in H. crepitans and found its structure to be that of 6,7-epoxy-5-hydroxyresiniferonol-14-(2,4-tetradecadienoate), i.e., daphne factor F3. These findings demonstrated that NT-4 activity accelerated by androgen might contribute to the pathogenesis of AGA and indicated that NT-4 inhibitors such as H. crepitans and daphne factor F3 might have a salutary effect on AGA.

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Bathrooms provide environments that encourage the formation of biofilms and mold on the hard surfaces of bathtubs and tile walls. To prevent such microbe-produced grime from spreading, methods such as bleaching and scrubbing may be commonly employed. The removal of dirt before the mold can grow is much more important, however, and therefore clarification of the composition and the accumulation mechanism of dirt and grime is needed. The grime collected from the shower walls of home bathrooms in our previous study consisted mainly of calcium soap, surfactants, fatty acids, and triacylglycerols. The triacylglycerols were suggested as playing an important role in the accumulation of grime, and in the present study we focused on their detailed composition and origin. A non-aqueous reverse-phase HPLC-ESI-MS/MS enabled us to characterize the small amount of triacylglycerols, but their MS/MS spectra were complicated by the presence of a number of product ions. Furthermore, there were no characteristic ions that allowed us to identify the triacylglycerols. Therefore, we adopted a new methodology in which only two ESI-MS/MS spectra corresponding to two m/z ranges in MS spectra (m/z 800-900 and 850-950) were acquired instead of a number of MS/MS spectra corresponding to each MS signal. This made it possible to estimate the origin of triacylglycerols by comparing the spectral patterns of the grime with those of the standard materials, with the desired convenience and quickness. The origin of the triacylglycerols should be closely related to the accumulation mechanism, though the triacylglycerols in the grime examined in the present study came mostly from human sebum instead of bath products and other sources.