Japanese Volunteers Research Articles

Correlation and association of plasma interleukin-6 and plasma platelet-derived microparticles, markers of activated platelets, in healthy individuals

Intorduction The aim of this study was to clarify the correlation and association of plasma IL-6 and PDMPs, both of which are associated with metabolic syndrome, in healthy individuals. Materials and Methods We conducted a cross-sectional study of 464 healthy Japanese volunteers (210 men and 254 women, median age 39 and 35 years, respectively) who had no signs, symptoms or history of cardiovascular- or cerebrovascular disease and took no medications. We assayed their IL-6 levels with a conventional ELISA kit and their PDMP levels by ELISA and monoclonal antibodies against CD42b and CD42a (glycoprotein Ib and IX). Results By multivariate analysis, the plasma level of PDMP was correlated with diastolic blood pressure (p = 0.015), platelet count (p < 0.001), high sensitivity C-reactive protein, and the plasma level of IL-6 (p < 0.001) in men (R 2 = 0.454, p < 0.001) and was correlated with platelet count (p < 0.001) and the plasma level of IL-6 (p < 0.001) in women (R 2 = 0.159, p < 0.001). Quartile range of plasma level of IL-6 was associated with plasma level of PDMP after adjustment for diastolic blood pressure, platelet count, and high sensitivity C-reactive protein in men (p < 0.001) and associated with plasma level of PDMP after adjustment for platelet count in women (p < 0.001). Conclusions These results suggest the plasma IL-6 is correlated and associated with the plasma PDMPs, markers of activated platelets in healthy individuals.

The association between personality, pain threshold and a single nucleotide polymorphism (rs3813034) in the 3′-untranslated region of the serotonin transporter gene (SLC6A4)

In 181 healthy Japanese volunteers we examined the relationship between personality, sensitivity to pain and a single nucleotide polymorphism (rs3813034) in the 3′ untranslated region (3′ UTR) of the serotonin transporter (5-HTT) gene (SLC6A4). Pain sensitivity was assessed by using cold and pressure thresholds. Personality was assessed by the Temperament and Character Inventory (TCI). Males without the T allele ( G/ G) showed a significantly higher spiritual acceptance (ST3) score than those who had the T allele ( T/ T and T/ G). Females with the T allele ( T/ T and T/ G) showed significantly higher transpersonal identification (ST2) and self-transcendence (ST) scores than those without the T allele ( G/ G). As for pain sensitivity and its relationship with TCI, we found a low negative correlation between cold water stimulation, disorderliness (NS4) and novelty seeking (NS) in males, whereas in females we found a low positive correlation between cold water stimulation, self-acceptance (SD4) and pure-hearted principles (C5), as well as pressure stimulation and SD4. It is possible that the 5-HTT 3′ UTR gene polymorphism affects the character dimensions of Cloniger’s theory, and that there might be a low correlation between pain and a part of the personality.

Esophageal Mucosal Injury With Low‐Dose Aspirin and Its Prevention by Rabeprazole

Aspirin is used widely as an antithrombotic drug for the prevention of cardiovascular and cerebrovascular events. Although aspirin increases the risk for gastrointestinal mucosal injury, the effect on esophageal mucosa is unclear. This study investigates whether aspirin induces esophageal mucosal injury and whether a proton-pump inhibitor can prevent such injury in relation to CYP2C19 genotypes. Fifteen healthy Japanese volunteers are dosed for 7 days in a 5-way randomly crossover trial: placebo, aspirin 100 mg, rabeprazole 10 mg, and aspirin 100 mg plus rabeprazole 10 mg either once daily or 4 times per day. All subjects undergo endoscopy and 24-hour intragastric pH monitoring on day 7. With the aspirin regimen, esophageal mucosal disorders occur in 7 patients (46.7%) (5, grade M; 2, grade A). The median 24-hour pH differs significantly among subjects who develop grade M or A gastroesophageal reflux disease and those who do not develop gastroesophageal reflux disease; the median pH in grade A gastroesophageal reflux disease is significantly lower (1.5 [range, 1.1-1.9]) than that in patients without gastroesophageal reflux disease (5.6 [range, 0.8-8.4], P = .04). Rabeprazole significantly inhibits acid secretion irrespective of CYP2C19 genotypes and decreases the incidence of aspirin-related esophageal injury and symptoms according to increasing pH value. Aspirin induces esophageal mucosal injury in an acid-dependent manner. Concomitant proton-pump inhibitor therapy may prevent advanced effects of low-dose aspirin.

Rapid detection of CYP2C18 genotypes by real-time fluorescence polymerase chain reaction.

In man, CYP2C19, a liver enzyme, plays an important role in the metabolism of several drugs. Mutation of the CYP2C19 gene results in a poor metaboliser phenotype. S-Mephenytoin hydroxylation genetic polymorphism is due to two mutations of the CYP2C19 gene, namely CYP2C19*2, located in exon 5, and CYP2C19*3, located in exon 4. CYP2C18 is also polymorphically expressed. The mutant alleles of this enzyme are CYP2C18m1, located in exon 2 and CYP2C18m2, located in the 5'-flanking region. We have developed an allele-specific TaqMan polymerase chain reaction (PCR) assay with which to detect CYP2C18 mutant alleles. This assay combines hybridization of the TaqMan probe and allele-specific amplification primers to the target DNA. The TaqMan probe is labelled with 6-carboxyfluorescein at the 5' end and 6-carboxytetramethylrhodamine together with a phosphate at the 3' end. Genotypes are separated according to the different threshold cycles of the wild type and mutant primers. We applied this procedure to DNA extracted from the blood or saliva of 144 healthy Japanese volunteers. The wt/wt, wt/m1, wt/m2, m1/m1, m1/m2 and m2/m2 genotypes of the CYP2C18 alleles detected by the assay were consistent with the results obtained from restriction enzyme cleavage. In accordance with a previous report, the genotypes of CYP2C18m1 and CYP2C18m2 coincided with those of CYP2C19*3 and CYP2C19*2, respectively. Therefore, detection of CYP2C18 mutant alleles also allows that of CYP2C19 mutant alleles. Among 19 poor metabolisers, eight showed the homozygous CYP2C19*2/CYP2C19*2, two the homozygous CYP2C19*3/CYP2C19*3 and nine the compound heterozygous CYP2C19*2/CYP2C19*3 genotype. We found the allele-specific TaqMan PCR assay rapid, simple and cost-effective, as well as suitable for high-throughput applications in a routine laboratory. This assay allows the fast and reliable detection of inherited disorders that might influence diagnosis and treatment.

Mangrove Rehabilitation Program in Southern Thailand with Japanese Volunteers and Local People

Mangrove Rehabilitation Program in Southern Thailand with Japanese Volunteers and Local People

Analysis of poly(ADP-ribose) polymerase-1 ( PARP1) gene alteration in human germ cell tumor cell lines

The poly(ADP-ribose) polymerase-1 protein (PARP-1) functions in DNA repair, maintenance of genomic stability, induction of cell death, and transcriptional regulation. We previously analyzed alterations of the PARP1 gene in 16 specimens of human germ cell tumors, and found a heterozygous sequence alteration that causes the amino acid substitution Met129Thr (M129T) in both tumor and normal tissues in a single patient. In this study, aberration of the PARP1 gene and protein was further analyzed in human germ cell tumor cell lines. We found a nonheterozygous sequence alteration that causes the amino acid substitution Glu251Lys (E251K) located at a conserved peptide stretch of PARP-1 in cell line NEC8. Sequencing of 95 samples from Japanese healthy volunteers revealed that all the samples were homozygous for the wild-type alleles at M129T and E251K. The M129T allele is thus suggested to be a rare single-nucleotide polymorphism (SNP). We observed a decrease in auto-poly(ADP-ribosyl)ation activity of PARP-1 proteins harboring M129T or E251K amino acid substitution, but the difference was not statistically significant. The levels of PARP-1 and poly(ADP-ribosyl)ation were heterogeneous among germ cell tumor cell lines. The SNPs of the PARP1 gene, as well as differences in the levels of PARP-1 and poly(ADP-ribosyl)ation of proteins, may influence germ cell tumor development and responses to chemotherapy and radiotherapy.

Influence of head rotation on upper esophageal sphincter pressure evaluated by high-resolution manometry system

Objectives This study aimed to quantify the effects of head rotation on upper esophageal sphincter (UES) pressure in healthy subjects using a novel high-resolution manometry (HRM) system. Study Design Prospective study. Setting Nagasaki University Hospital. Subjects and Methods Eighteen asymptomatic Japanese male adult volunteers were studied. A solid-state HRM was positioned to record resting UES pressure. After endoscopically confirming on which side of the pyriform sinus the manometric sensor was positioned within the hypopharynx, we measured the maximum and mean values of the resting UES pressure and the length of the zone of the UES along the esophagus with the patients in the following positions: 1) neutral and straightforward head position (NSF), 2) turning the head in the direction of the side in which the sensor was positioned (HSS), and 3) turning the head in the opposite direction of the side with sensor (HOS). Results The maximum and mean values of the resting UES pressure were statistically higher in HSS than in NSF ( P = 0.0001 and P < 0.0001, respectively), and were statistically lower in HOS than in NSF ( P < 0.0001 and P < 0.0001, respectively). The length of the zone of the UES was statistically shorter in HOS than in NSF ( P < 0.0001), but there was no significant difference in resting UES pressure along the esophagus between HSS and NSF ( P = 0.3024). Conclusion The present study provided us with physiological information regarding normal UES pressure in relation to head rotation. This data will be of aid to future clinical and investigative swallowing studies. Additionally, the current study provides evidence of the safety and usefulness of the head rotation maneuver for dysphagic patients.

Analysis of five benzophenone-type UV filters in human urine by liquid chromatography-tandem mass spectrometry

Benzophenone (BP)-type UV (ultraviolet) filters, especially 2-hydroxy-4-methoxybenzophenone (2OH–4MeO–BP), are widely used in the U.S., to protect the skin and hair from UV irradiation. Despite human exposures to UV filters through the dermal application of products containing sunscreen agents, few studies have examined the occurrence of UV filters in humans. Thus far, few sensitive methods are available for the determination of 2OH–4MeO–BP in human urine. Furthermore, methods for the determination of other BP derivatives, including 2,4-dihydroxybenzophenone (2,4OH–BP), which is formed from 2OH–4MeO–BP via metabolic activities of the cytochrome P450 enzymes, have not been available. In this study, we have developed a method for the analysis of five BP derivatives: 2OH–4MeO–BP, 2,4OH–BP, 2,2′-dihydroxy-4-methoxybenzophenone (2,2′OH–4MeO–BP), 2,2′,4,4′-tetrahydroxybenzophenone (2,2′,4,4′OH–BP), and 4-hydroxybenzophenone (4OH–BP) in human urine, using liquid–liquid extraction and liquid chromatograph (LC)-tandem mass spectrometer (MS/MS) analysis. The instrumental calibration range for each of the BP derivatives ranged from 0.05 to 100 ng ml−1, and showed excellent linearity (r > 0.99). The respective limits of detection (LODs) and limits of quantification (LOQs) were determined to be 0.082 and 0.28 ng ml−1 for both 2,4OH–BP and 4OH–BP; 0.13 and 0.44 ng ml−1 for 2,2′OH–4MeO–BP; and 0.28 and 0.90 ng ml−1 for both 2OH–4MeO–BP and 2,2′,4,4′OH–BP. Recoveries of BP derivatives through the entire analytical procedure were between 85.2 and 99.6%. The coefficients of variation (CVs) of five replicate analyses within 1 day, and across 5 days, were respectively 1.4 and 3.7% for 2,4OH–BP; 1.7 and 3.0% for 2OH–4MeO–BP; and 2.8 and 4.5% for 4OH–BP. When BP derivatives were determined in urine samples from 23 U.S. (Albany, New York) and 22 Japanese (Matsuyama, Ehime) volunteers, higher concentrations of 2,4OH–BP, 2OH–4MeO–BP, and 4OH–BP were found in samples collected from females in the Albany cohort, probably reflecting great usage by U.S. females. The urine sample from a known sunscreen user contained very high concentrations of 2,4OH–BP and 2OH–4MeO–BP. 2,2′,4,4′OH–BP and 2,2′OH–4MeO–BP were not detected in any of the urine samples analyzed. Our results indicate considerable exposure to highly estrogenic 2,4OH–BP and 2OH–4MeO–BP by females in the U.S., and suggest the need for further studies on potential health effects.

Effects of a Fish-Based Diet on the Serum Adiponectin Concentration in Young, Non-Obese, Healthy Japanese Subjects

Adiponectin has insulin-sensitizing, anti-atherogenic, and anti-inflammatory properties, and researchers have recently reported that omega-3 polyunsaturated fatty acid (PUFA) can increase the serum adiponectin concentration, suggesting that dietary factors, such as fish intake, may have an influence on the serum adiponectin concentration. In general, Japanese subjects consume twice as much fish as people in other countries. We hypothesized that incremental change in serum omega-3 PUFA levels by fish intake is an important regulator of serum adiponectin even in Japanese subjects. The aim of this study was to explore the relationship among fish consumption, serum omega-3 PUFA, such as eicosapentaenoic acid (EPA), levels, and serum adiponectin levels. We recruited 17 healthy Japanese volunteers (seven men and 10 women) for an 8-week fish-diet intervention (omega-3 PUFA 3.0 g/day) without affecting total energy intake, and measured serum adiponectin concentration and fatty acid profiles. Fish-diet intervention significantly increased the serum adiponectin concentration in women (from 13.5+/-4.6 to 15.8+/-5.2 microg/mL, p <0.01) but not in men (from 8.7+/-2.8 to 8.7+/-2.5 microg/mL). Serum omega-3 PUFA increased more in female subjects than male subjects after the fish-diet intervention (57.3+/-86.6 vs 150.9+/-46.7 microg/mL, p=0.011), suggesting that changes in omega-3 PUFA concentration may explain the different response between sexes. A fish-based diet intervention increased the serum adiponectin concentration in young, non-obese, healthy Japanese female subjects. The increment in serum omega-3 PUFA may regulate the serum adiponectin concentration.

Peripapillary retinal nerve fiber layer thickness in normal Japanese eyes measured with optical coherence tomography

To measure peripapillary retinal nerve fiber layer (RNFL) thickness in healthy Japanese individuals using optical coherence tomography (OCT). OCT was used to measure the eyes of 460 healthy Japanese volunteers aged 20 to 84. One eye of each individual was selected for the statistical analysis. the average circumpapillary (cp) rnfl thickness of all eyes was 111.8 +/- 10.0 microm. a statistically significant negative correlation was found between the average cp rnfl thickness and age. for every decade increase in age, the average cp rnfl thickness decreased by approximately 2.2 microm. the average cp rnfl thickness was estimated to decrease by 0.18% per year. the age-associated reduction in cp rnfl thickness was particularly noted in the inferior-temporal to superior-temporal segments: Age-related cp RNFL loss varies according to segment. When OCT is used to evaluate cp RNFL thickness, regional and age-related differences need to be taken into consideration.

Dysfunctional Parenting Styles Increase Interpersonal Sensitivity in Healthy Subjects

The effects of dysfunctional parenting styles on interpersonal sensitivity were studied in 640 Japanese volunteers. Interpersonal sensitivity was assessed by the Interpersonal Sensitivity Measure (IPSM), and perceived parental rearing was evaluated by the Parental Bonding Instrument (PBI), which is consisted of care and protection factors. Parental rearing was classified into 4 types, i.e., optimal parenting (high care/low protection), affectionate constraint (high care/high protection), neglectful parenting (low care/low protection), and affectionless control (low care/high protection). Males with paternal affectionless control showed higher total IPSM scores than those with paternal optimal parenting (p = 0.022). Females with maternal affectionate constraint (p = 0.001), neglectful parenting (p = 0.022), and affectionless control (p = 0.003) showed higher total IPSM scores than those with maternal optimal parenting. In males and females, dysfunctional parenting styles by the opposite-sex parents did not affected total IPSM scores. The present study suggests that in both males and females interpersonal sensitivity is increased by dysfunctional parenting styles by the same-sex parents.

Effects of the P-glycoprotein Inducer Carbamazepine on Fexofenadine Pharmacokinetics

The aim of this study was to evaluate the possible effects of carbamazepine, a P-glycoprotein inducer, on fexofenadine pharmacokinetics. Twelve healthy Japanese volunteers (nine males and three females) were enrolled in this study after giving written informed consent. This randomized open-label study consisted of two phases (control and 7-day treatment) with a 2-week washout period. In the control phase, volunteers received 60 mg fexofenadine hydrochloride after an overnight fast. In the treatment phase, carbamazepine was dosed 100 mg three times daily (for a total daily dose of 300 mg) for 7 days, and on Day 7, a single 60-mg dose of fexofenadine was coadministered with a 100-mg dose of carbamazepine. The plasma concentrations and urinary excretion of fexofenadine were measured for 24 hours after dosing. Carbamazepine pretreatment significantly altered fexofenadine pharmacokinetics, decreasing the mean (+/- standard deviation) peak plasma concentration from 176.6 (+/- 82.1) ng/mL to 103.2 (+/- 33.6) ng/mL (P < 0.01) and the area under the plasma concentration-time curve from 1058.4 (+/- 528.7) ng/h/mL to 604.8 (+/- 255.9) ng/h/mL (P < 0.01) without changing the elimination half-life. Relatively, carbamazepine significantly reduced the amount of fexofenadine excreted into the urine from 8.1 (+/- 2.1) mg to 4.5 (+/- 1.4) mg (P < 0.001), although the renal clearance of fexofenadine remained constant between the two study phases. Thus, this study indicates that carbamazepine significantly decreases fexofenadine plasma concentrations, probably as a result of P-glycoprotein induction in the small intestine. Carbamazepine treatment, therefore, is of moderate clinical significance for patients receiving fexofenadine.

Effect of Aging on Corneal Biomechanical Parameters Using the Ocular Response Analyzer

To assess the effect of aging on corneal biomechanical parameters in a normal population. We prospectively examined 204 normal eyes of 204 healthy Japanese volunteers (68 men, 136 women; mean age 46.7+/-19.4 years [range: 19 to 89 years]). Corneal hysteresis, corneal resistance factor, corneal-compensated intraocular pressure (IOP(cc)), and Goldmann-correlated intraocular pressure (IOP(G)) were qualitatively assessed using a Reichert Ocular Response Analyzer. Central corneal thickness was measured using an ultrasound pachymeter. This measurement was performed 3 times, and the mean value obtained was used for statistical analysis. The relationships between patient age and corneal biomechanical parameters, or age and intraocular pressure (IOP), were investigated. Mean corneal hysteresis and corneal resistance factor were 10.1+/-1.5 mmHg and 10.1+/-1.6 mmHg, respectively. Mean central corneal thickness was 539.1+/-30.9 microm. A weak, but significant, negative correlation was found between age and corneal hysteresis (Pearson's correlation coefficient r=-0.17, P=.02) and corneal resistance factor (r=-0.18 P=.01). On the other hand, no significant correlation was found between age and central corneal thickness (r=-0.06, P=.41), age and IOP(cc) (r=-0.02, P=.82), or age and IOP(G) (r=-0.11, P=.11). Corneal biomechanical parameters are significantly decreased by aging without significant changes in central corneal thickness or IOP, suggesting that age-related structural changes resulting from collagen cross-linking may lead to a reduction of corneal biomechanical variables independent of central corneal thickness or IOP.

Non-invasive prediction of hematocrit levels by portable visible and near-infrared spectrophotometer

Background After blood donation, in some individuals having polycythemia, dehydration causes anemia. Although the hematocrit (Ht) level is closely related to anemia, the current method of measuring Ht is performed after blood drawing. Furthermore, the monitoring of Ht levels contributes to a healthy life. Therefore, a non-invasive test for Ht is warranted for the safe donation of blood and good quality of life. Methods A non-invasive procedure for the prediction of hematocrit levels was developed on the basis of a chemometric analysis of visible and near-infrared (Vis–NIR) spectra of the thumbs using portable spectrophotometer. Transmittance spectra in the 600- to 1100-nm region from thumbs of Japanese volunteers were subjected to a partial least squares regression (PLSR) analysis and leave-out cross-validation to develop chemometric models for predicting Ht levels. Results Ht levels of masked samples predicted by this model from Vis–NIR spectra provided a coefficient of determination in prediction of 0.6349 with a standard error of prediction of 3.704% and a detection limit in prediction of 17.14%, indicating that the model is applicable for normal and abnormal value in Ht level. Conclusions These results suggest portable Vis–NIR spectrophotometer to have potential for the non-invasive measurement of Ht levels with a combination of PLSR analysis.

Pharmacokinetics and safety of single and multiple doses of Asacol tablets in Japanese healthy volunteers

The pharmacokinetics and safety of Asacol (Tillotts Pharma AG, Ziefen, Switzerland), which has been used worldwide to treat ulcerative colitis and Crohn's disease, were studied in Japanese healthy male volunteers. Drug plasma concentrations and urinary and fecal excretions after a single dose (400-4800 mg) and multiple doses (3600 mg/day for 7 days) were investigated. All adverse events were "not serious." The peak plasma concentration (C max) was reached at 12.3-18.0 hours after a single dose, and the C max and area under the plasma concentration-time curve (AUC) of mesalazine and its N-acetyl metabolite were proportional to the doses. The C max and AUC in non-Japanese subjects reported in the literature were closely correlated to findings in Japanese subjects, and external excretions were also similar in the Japanese and non-Japanese subjects. Asacol was safe and well tolerated in this Japanese population, and the non-Japanese clinical data could be extrapolated to the Japanese population.

일본 노인의 자원봉사경험에 관한 사례연구

Japan has already entered into an aged society, and volunteer activities of old adults are more activated, compared to Korea. This case study of Japanese volunteer experiences aimed to seek some implications for the activation of volunteer activities of old adults in Korea where productive and successful aging recently increases. For the study, 9 Japanese old adults volunteer with facilities for old adults in Japan were interviewed on December, 2008. In addition, observations and content analysis on 00 published by old adult volunteers were used for data analysis. Interview took one and half hours on average, and questions were not restricted to freely answer them, but some questions on beginning time, motive, frequency, and effects of volunteer activities on community were semi-structured. Interview were recorded and analysed. Volunteer participation of Japanese old adults was initiated by surrounding ones' recommendation, and past experiences and occupation were not directly related to volunteer activities. The type of volunteer activities occurred in all fields of facilities for old adults. Old adults through volunteer activities found the true meaning of life, and extended their knowledge on organization, diseases, community and social relationship. The interviewees answered that they will trust themselves to the facilities when they get ill later. Japanese elderly volunteers recommended to Korean ones that they participate in activities as a main body, enjoy it very much, grow through volunteering education, seek family support, and serve to community with a group of friends.

Evaluation of the 24-Hour Profiles of Physiological Insulin, Glucose, and C-Peptide in Healthy Japanese Volunteers

Some studies have demonstrated the benefit of blood glucose control as close as possible to physiological conditions. Not enough reports have investigated in detail the 24-h plasma profiles of insulin/glucose/C-peptide. Here we investigated the 24-h plasma profiles of physiological insulin/glucose/C-peptide in healthy Japanese adults. In order to evaluate the 24-h profiles of physiological insulin/glucose/C-peptide profiles, 42 blood samples were taken from each subject in our group of healthy Japanese volunteers to measure the 24-h profile with three standardized meals. Plasma glucose and insulin increased rapidly followed by a rapid decrease after each meal with little variation at night. The average peak values of insulin after each meal were as follows: 426.20 pmol/L (breakfast), 373.75 pmol/L (lunch), and 410.28 pmol/L (dinner). The average times to peak insulin were 0.651 h (breakfast), 0.677 h (lunch), and 0.689 h (dinner). The corresponding average maximum postprandial plasma glucose levels were 8.39 mmol/L (breakfast), 8.77 mmol/L (lunch), and 8.74 mmol/L (dinner). The average times to peak glucose were 0.738 h (breakfast), 0.650 h (lunch), and 0.625 h (dinner). The average maximum postprandial C-peptide levels were 2.64 nmol/L (breakfast), 2.55 nmol/L (lunch), and 2.67 nmol/L (dinner). No major differences were found in these parameters between the Caucasian and Japanese populations. This is the first investigation to measure the 24-h profiles of insulin/glucose/C-peptide in healthy Japanese volunteers with standardized meals. It is hoped this information will provide useful reference for future research and clinical management.

Isoflavone supplements stimulated the production of serum equol and decreased the serum dihydrotestosterone levels in healthy male volunteers

The aim of this study was to evaluate the effect of supplementing healthy men with soy isoflavones on the serum levels of sex hormones implicated in prostate cancer development. A total of 28 Japanese healthy volunteers (18 equol producers and 10 equol non-producers) between 30 and 59 years of age were given soy isoflavones (60 mg daily) supplements for 3 months, and the changes in their sex hormone levels were investigated at the baseline and after administration. The serum and urine concentrations of daidzein, genistein, and the levels of equol in the fasting blood samples and 24-h stored urine samples were also measured. All 28 volunteers completed the 3-month supplementation with isoflavone. No changes in the serum levels of estradiol and total testosterone were detected after 3-month supplementation. The serum levels of sex hormone-binding globulin significantly increased, and the serum levels of free testosterone and dihydrotestosterone (DHT) decreased significantly after 3-month supplementation. Among the 10 equol non-producers, equol became detectable in the serum of two healthy volunteers after 3-month supplementation. This study revealed that short-term administration of soy isoflavones stimulated the production of serum equol and decreased the serum DHT level in Japanese healthy volunteers. These results suggest the possibility of converting equol non-producers to producers by prolonged and consistent soy isoflavones consumption.

Sagging of the cheek is related to skin elasticity, fat mass and mimetic muscle function

Facial sagging is associated with aging, although the mechanism remains unclear. The aim of this study was to investigate the mechanism of facial sagging by examining the relationship of sagging severity to changes of skin elasticity, fat mass and facial muscle function at the cheek. Faces of 108 healthy Japanese female volunteers, aged 20-60 years were photographed at an angle of 45 degrees . Standard scores of sagging severity were established by analyzing the photographs. We examined the correlations of scored sagging levels with skin elasticity measured with a Cutometer MPA 580, fat content estimated by bioelectrical impedance analysis and facial muscle function (lip sealing force and occlusal force) in middle-aged female volunteers (30-40 years) with a wide range of sagging scores. Because the upper, lower and lateral areas in the cheek may show severe sagging, a six-grade score of sagging severity was separately established for each area. Each score was significantly correlated positively with age (20-60 years). In middle-aged volunteers, the sagging scores in all three areas of the cheek were significantly and negatively associated with skin elasticity. Body fat percentage was significantly and positively correlated with the sagging scores in the lower and lateral areas, although the correlation was only weakly positive in the upper area. Mimetic muscle function, measured in terms of lip sealing pressure, was significantly and negatively correlated with the sagging score only at the upper area of the cheek, but masticatory muscle function, measured in terms of occlusal force pressure, was not associated with the sagging score. Sagging may be associated with the reduction of skin elasticity and mimetic muscle function and increase of fat mass, but the relationships are different in different areas of the cheek.

J. Cosmet. Sci., 59, 263–289 (July/August 2008) Characterization of curved hair of Japanese women with reference to internal structures and amino acid composition

Accepted for publication February 20, 2008SynopsisThe variation of hair curvature in Japanese women was quantitatively investigated and the structure of curved hair was characterized with transmission electron microscopy (TEM) and amino acid analysis. Two hundred and thirty Japanese women volunteers, aged from 10 to 70 years, were randomly selected. The evaluation of the volunteers’ natural hair shape showed that 53% of Japanese women have straight hair, while the remaining 47% have curved hair (varying from a slightly wavy shape to a frizzy style). The average curl radius of the volunteers’ hair was determined to be 4.4 ± 2.3 cm, and ranged widely from 0.6 to 16 cm. The TEM observation of curved hair fiber revealed an inhomogenous internal structure between the outer and inner regions of the curved shape. In relation to the inhomogeneous structure of the curved hair, different amino acid composition of the hair keratin was observed between the outer and inner regions. Interestingly, these results of the TEM observation and the amino acid analysis are analogous to the difference between the ortho‐and paracortical cells in wool fibers, suggesting the universal structure of curved mammalian hair.