4-(4-Hydroxyphenyl)-2-butanol (rhododendrol)-induced melanocyte cytotoxicity is enhanced by UVB exposure through generation of oxidative stress.

4-(4-Hydroxyphenyl)-2-butanol (rhododendrol, RD), a skin-whitening agent, was reported to cause skin depigmentation in some users, which is attributed to its cytotoxicity to melanocyte. It was reported that cytotoxicity to melanocyte is possibly mediated by oxidative stress in a tyrosinase activity-dependent manner. We examined the effect of UV radiation (UVR) on RD-induced melanocyte cytotoxicity as an additional aggravating factor.

Relationship between Long Interspersed Nuclear Element-1 DNA Methylation in Leukocytes and Dyslipidemia in the Japanese General Population.

Aim: Aberrant global DNA methylation is involved in the development of several diseases, including cardiovascular disease (CVD). We investigated whether the methylation of long interspersed nuclear element-1 (LINE-1) in leukocytes is associated with dyslipidemia, a major risk factor for CVD, in the Japanese general population.

Methods: We conducted a cross-sectional study consisting of 420 Japanese subjects (187 men and 233 women) without a clinical history of cancer, stroke, or ischemic heart disease.

Association of Adiponectin With Cancer and All-Cause Mortality in a Japanese Community-Dwelling Elderly Cohort: A Case-Cohort Study.

Background: Most studies of plasma adiponectin (APN) and mortality among community-dwelling elderly focus on cardiovascular disease, but data on the relationship between plasma APN and cancer mortality is exiguous. We investigated whether APN is associated with cancer mortality in community-dwelling elderly people.

Methods: We conducted a case-cohort study within the New Integrated Suburban Seniority Investigation (NISSIN) Project using a randomly drawn sub-cohort of 697 subjects (351 men and 346 women; mean age 64.

Monitoring Shedding of Five Genotypes of RotaTeq Vaccine Viruses by Genotype-Specific Real-Time Reverse Transcription-PCR Assays.

RotaTeq (RV5) is a widely used live attenuated pentavalent rotavirus (RV) vaccine. Although fecal shedding of RV vaccine strains persists for long time periods, it is unclear how each vaccine strain replicates in intestinal tissue and is excreted in stool. To examine this issue, we established RV5 genotype-specific real-time reverse transcription-PCR (RT-PCR) assays.

Effect of auditory stimulus on executive function and execution time during cognitively demanding stepping task in patients with Parkinson's disease.

Start hesitation in patients with Parkinson's disease (PD) occurs predominantly during distractive and conflictual situations. The aim of this study was to investigate how differently an auditory stimulus (AS) influences execution function and execution time during a cognitively demanding stepping task in PD patients as compared to healthy controls. PD patients and healthy controls stepped forward in response to a visual imperative stimulus of an arrow.

CT-based attenuation correction and resolution compensation for I-123 IMP brain SPECT normal database: a multicenter phantom study.

Objective: Statistical image analysis of brain SPECT images has improved diagnostic accuracy for brain disorders. However, the results of statistical analysis vary depending on the institution even when they use a common normal database (NDB), due to different intrinsic spatial resolutions or correction methods. The present study aimed to evaluate the correction of spatial resolution differences between equipment and examine the differences in skull bone attenuation to construct a common NDB for use in multicenter settings.

Coordination of plantar flexor muscles during bipedal and unipedal stances in young and elderly adults.

To investigate the effects of aging on coordination of plantar flexor muscles during bipedal and unipedal stances, we examined a relationship between the center of pressure sway and electromyographic activity of these muscles, and also the common neural input, using a coherence analysis. Healthy young and elderly adults were asked to perform bipedal and unipedal standing. The electromyograms were recorded unilaterally from the medial and lateral gastrocnemius (MG and LG) and soleus (SL) muscles, and the common input was analyzed for MG-LG, MG-SL, and LG-SL pairs in two frequency bands: a delta band, that is associated with force variability, and a beta band, that could reflect the corticospinal drive.

The potent pro-oxidant activity of rhododendrol-eumelanin is enhanced by ultraviolet A radiation.

RS-4-(4-hydroxyphenyl)-2-butanol (rhododendrol, RD), a skin-whitening agent, is known to induce leukoderma in some consumers. To explore the mechanism underlying this effect, we previously showed that the oxidation of RD with mushroom or human tyrosinase produces cytotoxic quinone oxidation products and RD-eumelanin exerts a potent pro-oxidant activity. Cellular antioxidants were oxidized by RD-eumelanin with a concomitant production of H O .

Biochemical Mechanism of Rhododendrol-Induced Leukoderma.

-4-(4-hydroxyphenyl)-2-butanol (rhododendrol (RD))-a skin-whitening ingredient-was reported to induce leukoderma in some consumers. We have examined the biochemical basis of the RD-induced leukoderma by elucidating the metabolic fate of RD in the course of tyrosinase-catalyzed oxidation. We found that the oxidation of racemic RD by mushroom tyrosinase rapidly produces RD-quinone, which gives rise to secondary quinone products.

Oxidized human serum albumin as a possible correlation factor for atherosclerosis in a rural Japanese population: the results of the Yakumo Study.

Background: The effect of the redox state of human serum albumin (HSA) on the antioxidant properties of the entire body has been a focus of recent research. The usefulness of HSA redox state as a biomarker for reducing oxidative stress has been investigated in clinical settings; however, evidence for its significance as a health index in non-clinical settings is yet to be established. This study aimed to examine the associations between HSA redox state and the atherosclerotic indices of carotid intima-media thickness (IMT) and plaque formation in a rural Japanese population.

Acid hydrolysis reveals a low but constant level of pheomelanin in human black to brown hair.

We previously reported a constant ratio of the benzothiazole pheomelanin marker thiazole-2,4,5-tricarboxylic acid (TTCA) to the eumelanin marker pyrrole-2,3,5-tricarboxylic acid (PTCA) in eumelanic, black human hair. A constant level (20%-25%) of benzothiazole-type pheomelanin was recently demonstrated in human skin with varying concentrations of melanin. Therefore, in this study, we aimed to investigate the origin of pheomelanin markers in black to brown human hair by developing a method to remove protein components from hair by heating with 6 M HCl at 110°C for 16 hr.

Auditory stimulus has a larger effect on anticipatory postural adjustments in older than young adults during choice step reaction.

Purpose: The study aim was to compare the influence of an auditory stimulus (AS) on anticipatory postural adjustments (APAs) between young and older adults during a choice step reaction.

Methods: Sixteen young and 19 older adults stepped forward in response to a visual imperative stimulus of an arrow. We used a choice reaction time (CRT) task and a Simon task which consisted of congruent and incongruent conditions.

Alcohol consumption and mortality from aortic disease among Japanese men: The Japan Collaborative Cohort study.

Background And Aims: Only a few population-based prospective studies have examined the association between alcohol consumption and abdominal aortic aneurysm, and the results are inconsistent. Moreover, no evidence exists for aortic dissection. We examined the effect of alcohol consumption on risk of mortality from aortic diseases.

Association of subcutaneous and visceral fat with circulating microRNAs in a middle-aged Japanese population.

Purpose It has been demonstrated that circulating microRNA profiles are affected by physiological conditions. Several studies have demonstrated that microRNAs play important roles in the regulation of adiposity. However, few have investigated the relationship between circulating microRNAs and obesity, which has become a major public health problem worldwide.

Photodegradation of Eumelanin and Pheomelanin and Its Pathophysiological Implications.

Eumelanin is photoprotective for pigmented tissues while pheomelanin is phototoxic. In this review, we summarize current understanding of how eumelanin and pheomelanin structures are modified by ultraviolet A (UVA) and also by visible light and how reactive oxygen species participate in those processes. Alkaline hydrogen peroxide oxidation was employed to characterize eumelanin and benzothiazole-type pheomelanin, giving pyrrole-2,3,5-tricarboxylic acid (PTCA) and thiazole-2,4,5-tricarboxylic acid (TTCA), respectively.

Melanic variation underlies aposematic color variation in two hymenopteran mimicry systems.

The stinging hymenopteran velvet ants (Mutillidae) and bumble bees (Apidae: Bombus spp.) have both undergone extensive diversification in aposematic color patterns, including yellow-red hues and contrasting dark-light body coloration, as a result of Müllerian mimicry. Understanding the genetic and developmental mechanisms underlying shifts in these mimetic colors requires characterization of their pigmentation.

Analysis of the origin of inherited chromosomally integrated human herpesvirus 6 in the Japanese population.

Integration of the complete human herpesvirus 6 (HHV-6) genome into the telomere of a chromosome has been reported in some individuals (inherited chromosomally integrated HHV-6; iciHHV-6). Since the proportion of iciHHV-6-positive individuals with integration in chromosome 22 is high in Japan, we hypothesized a founder effect. In this study, we sought to elucidate the reason for the high proportion of viral integrations into chromosome 22.

Compound 48/80, a mast cell degranulator, causes oxidative damage by enhancing vitamin C synthesis via reduced glutathione depletion and lipid peroxidation through neutrophil infiltration in rat livers.

In this study, we examined whether compound 48/80 (C48/80), a mast cell degranulator, causes hepatic oxidative damage in rats. Serum and liver biochemical parameters were determined 0.5, 3 or 6 h after a single treatment with C48/80 (0.

Development of real-time RT-PCR assays for detection of three classes of HHV-6A gene transcripts.

Human herpesvirus 6 (HHV-6), a member of the betaherpesvirus family, has two distinct species: HHV-6A and HHV-6B. HHV-6B real-time reverse transcription polymerase chain reaction (RT-PCR) has been used to distinguish between active and latent viral infection. In this study, we developed a real-time RT-PCR assay to detect HHV-6A-specific transcripts and evaluated its reliability for analysis of clinical samples.

Pheomelanogenesis is promoted at a weakly acidic pH.

The diversity of pigmentation in the skin, hair, and eyes of humans has been largely attributed to the diversity of pH in melanosomes with an acidic pH being proposed to suppress melanin production, especially eumelanogenesis. We previously showed that an acidic pH greatly suppresses the late stage of eumelanogenesis after the dopachrome stage. The oxidation of tyrosine by tyrosinase in the presence of cysteine forms cysteinyldopa isomers, which are further oxidized to give rise to pheomelanin via benzothiazine intermediates.

Tyrosinase-Catalyzed Oxidation of the Leukoderma-Inducing Agent Raspberry Ketone Produces (E)-4-(3-Oxo-1-butenyl)-1,2-benzoquinone: Implications for Melanocyte Toxicity.

The exposure of human skin to 4-(4-hydroxyphenyl)-2-butanone (raspberry ketone, RK) is known to cause chemical/occupational leukoderma. RK has a structure closely related to 4-(4-hydroxyphenyl)-2-butanol (rhododendrol), a skin whitening agent that was found to cause leukoderma in the skin of consumers in 2013. Rhododendrol is a good substrate for tyrosinase and causes a tyrosinase-dependent cytotoxicity to melanocytes, cells that are responsible for skin pigmentation.

The potent pro-oxidant activity of rhododendrol-eumelanin induces cysteine depletion in B16 melanoma cells.

RS-4-(4-Hydroxyphenyl)-2-butanol (rhododendrol, RD), a skin-whitening agent, is known to induce leukoderma in some people. To explore the mechanism underlying this effect, we previously showed that the oxidation of RD with mushroom or human tyrosinase produces cytotoxic quinone oxidation products. We then examined the metabolism of RD in B16F1 melanoma cells in vitro and detected RD-pheomelanin and RD-quinone bound to non-protein and protein thiols.

Mutant botrocetin-2 inhibits von Willebrand factor-induced platelet agglutination.

Unlabelled: Essentials Botrocetin-2 (Bot2) binds to von Willebrand factor (VWF) and induces platelet agglutination. We identified Bot2 residues that are required for binding to VWF and glycoprotein (GP) Ib. We produced a mutant Bot2 that binds to VWF but inhibits platelet agglutination.