Attitudes and behaviors regarding sun exposure in Japan compared to Europe and North America

The objective of our study was to assess the attitudes and behaviors in Japan regarding sun exposure and compare them to those in Europe and North America. The study population was a representative sample of individuals aged >18 years from Ipsos panels in Japan (N = 1000), North America (N = 1000), and Europe (N = 6000) using the quota method. Questionnaires covered habits, practices, and perceptions regarding sun exposure. Results revealed that the majority of people (80.1%) believed that the sun gives them energy, and 61.1% considered that being tanned made them look healthier. However, there was a significant difference between men and women regarding the appeal of tanned skin, with 54.95% of men versus 34.67% (p < 0.001) of women seeing a tan as an aesthetic asset. People aged <40 years were less likely to find a tan attractive (30.3%) compared to those aged ≥40 years (48.9%) (p < 0.001). Of those questioned, 45.70% of used sunscreen with a much higher use among women (70.10%) than men (18.74%) (p < 0.001). Almost 54% of people said they stayed in the shade to protect themselves from the sun with this behavior being more prevalent among women (67.05%) and fair-skinned individuals (56.13%). Fear of the risks of sun exposure was more common among women, with 84.8% fearing premature skin aging, compared to 71.8% of men (p < 0.001). In Japan, 44.30% of those questioned said tanned skin was attractive (p < 0.001); for Europeans and North Americans the proportions were 81.1% and 77.6%, respectively. Only a quarter (25.80%) thought it essential to return from vacation with a tan. On the other hand, Europeans showed a strong recognition of the energy the sun brings (83.18%), and widely believed that tanned skin is attractive (82.32%) and healthy (73.15%). In North America, attitudes were similar to those in Europe regarding the attractiveness of tanned skin (77.65%) and the importance of returning tanned from vacation (48.15%). Compared to Europeans and North Americans, the Japanese seemed to be more cautious about sun-induced hazards and considered lighter skin to be more attractive.

Effects of empagliflozin on progression of chronic kidney disease: a prespecified secondary analysis from the empa-kidney trial

BACKGROUND

Sodium-glucose co-transporter-2 (SGLT2) inhibitors reduce progression of chronic kidney disease and the risk of cardiovascular morbidity and mortality in a wide range of patients. However, their effects on kidney disease progression in some patients with chronic kidney disease are unclear because few clinical kidney outcomes occurred among such patients in the completed trials. In particular, some guidelines stratify their level of recommendation about who should be treated with SGLT2 inhibitors based on diabetes status and albuminuria. We aimed to assess the effects of empagliflozin on progression of chronic kidney disease both overall and among specific types of participants in the EMPA-KIDNEY trial.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA), and included individuals aged 18 years or older with an estimated glomerular filtration rate (eGFR) of 20 to less than 45 mL/min per 1·73 m2, or with an eGFR of 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher. We explored the effects of 10 mg oral empagliflozin once daily versus placebo on the annualised rate of change in estimated glomerular filtration rate (eGFR slope), a tertiary outcome. We studied the acute slope (from randomisation to 2 months) and chronic slope (from 2 months onwards) separately, using shared parameter models to estimate the latter. Analyses were done in all randomly assigned participants by intention to treat. EMPA-KIDNEY is registered at ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and then followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroups of eGFR included 2282 (34·5%) participants with an eGFR of less than 30 mL/min per 1·73 m2, 2928 (44·3%) with an eGFR of 30 to less than 45 mL/min per 1·73 m2, and 1399 (21·2%) with an eGFR 45 mL/min per 1·73 m2 or higher. Prespecified subgroups of uACR included 1328 (20·1%) with a uACR of less than 30 mg/g, 1864 (28·2%) with a uACR of 30 to 300 mg/g, and 3417 (51·7%) with a uACR of more than 300 mg/g. Overall, allocation to empagliflozin caused an acute 2·12 mL/min per 1·73 m2 (95% CI 1·83-2·41) reduction in eGFR, equivalent to a 6% (5-6) dip in the first 2 months. After this, it halved the chronic slope from -2·75 to -1·37 mL/min per 1·73 m2 per year (relative difference 50%, 95% CI 42-58). The absolute and relative benefits of empagliflozin on the magnitude of the chronic slope varied significantly depending on diabetes status and baseline levels of eGFR and uACR. In particular, the absolute difference in chronic slopes was lower in patients with lower baseline uACR, but because this group progressed more slowly than those with higher uACR, this translated to a larger relative difference in chronic slopes in this group (86% [36-136] reduction in the chronic slope among those with baseline uACR <30 mg/g compared with a 29% [19-38] reduction for those with baseline uACR ≥2000 mg/g; ptrend<0·0001).

INTERPRETATION

Empagliflozin slowed the rate of progression of chronic kidney disease among all types of participant in the EMPA-KIDNEY trial, including those with little albuminuria. Albuminuria alone should not be used to determine whether to treat with an SGLT2 inhibitor.

FUNDING

Boehringer Ingelheim and Eli Lilly.

Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial

BACKGROUND

The EMPA-KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62-0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16-1·59), representing a 50% (42-58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1).

INTERPRETATION

In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease.

FUNDING

Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council.

[Recompensation of complications in patients with hepatitis B virus-related decompensated cirrhosis treated with entecavir antiviral therapy]

Objective: To analyze the occurrence of recompensation conditions in patients with chronic hepatitis B virus-related decompensated cirrhosis after entecavir antiviral therapy. Methods: Patients with hepatitis B virus-related decompensated cirrhosis with ascites as the initial manifestation were prospectively enrolled. Patients who received entecavir treatment for 120 weeks and were followed up every 24 weeks (including clinical endpoint events, hematological and imaging indicators, and others) were calculated for recompensation rates according to the Baveno VII criteria. Measurement data were compared using the Student t-test or Mann-Whitney U test between groups. Categorical data were compared by the χ (2) test or Fisher's exact probability method between groups. Results: 283 of the 320 enrolled cases completed the 120-week follow-up, and 92.2% (261/283) achieved a virological response (HBV DNA 20 IU/ml). Child-Pugh and MELD scores were significantly improved after treatment (8.33 ± 1.90 vs. 5.77 ± 1.37, t = 12.70, P < 0.001; 13.37 ± 4.44 vs. 10.45 ± 4.58, t = 5.963, P < 0.001). During the 120-week follow-up period, 14 cases died, two received liver transplants, 19 developed hepatocellular cancer, 11 developed gastroesophageal variceal bleeding, and four developed hepatic encephalopathy. 60.4% (171/283) (no decompensation events occurred for 12 months) and 56.2% (159/283) (no decompensation events occurred for 12 months and improved liver function) of the patients had achieved clinical recompensation within 120 weeks. Patients with baseline MELD scores > 15 after active antiviral therapy achieved higher recompensation than patients with baseline MELD scores ≤15 [50/74 (67.6%) vs. 109/209 (52.2%), χ (2) = 5.275, P = 0.029]. Conclusion: Antiviral therapy can significantly improve the prognosis of patients with hepatitis B virus-related decompensated cirrhosis. The majority of patients (56.2%) had achieved recompensation. Patients with severe disease did not have a lower probability of recompensation at baseline than other patients.

Efflux pump gene expression study using RNA-seq in multidrug-resistant TB

BACKGROUND: The mechanism underlying kanamycin (KM) resistance in Mycobacterium tuberculosis is not well understood, although efflux pump proteins are thought to play a role. This study used RNA-seq data to investigate changes in the expression levels of efflux pump genes following exposure to KM.METHODS: RNA expression of efflux pump and regulatory genes following exposure to different concentrations of KM (minimum inhibitory concentration MIC 25 and MIC50) in rrs wild-type strain and rrs A1401G mutated strain were compared with the control group.RESULTS: The selected strains had differential RNA expression patterns. Among the 71 putative efflux pump and regulatory genes, 46 had significant fold changes, and 12 genes (Rv0842, Rv1146, Rv1258c, Rv1473, Rv1686c, Rv1687c, Rv1877, Rv2038c, Rv3065, Rv3197a, Rv3728 and Rv3789) that were overexpressed following exposure to KM were thought to contribute to drug resistance. Rv3197A (whiB7) showed a distinct fold change based on the concentration of KM.CONCLUSION: The significant changes in the expression of the efflux pump and regulatory genes following exposure to KM may provide insights into the identification of a new resistance mechanism.

The potential skin lightening candidate, senolytic drug ABT263, for photoageing pigmentation

Senescent cells accumulate in several tissues during ageing, including the skin, and contribute to the functional decline of the skin via the senescence-associated secretory phenotypes (SASPs) ¹ . Due to the potential negative effects of SASPs during the ageing process, drugs that selectively target senescent cells or SASPs represent an important therapeutic strategy to delay skin ageing. The selective induction of cell death specifically to kill senescent cells using drugs, referred to as senolytics, is a main approach to achieve this strategy ² .

[Epidemiological investigation of tinnitus in Sichuan and Chongqing]

Objectives: To investigate the prevalence and associated risk factors of tinnitus in Sichuan and Chongqing. Methods: We designed a tinnitus epidemiological questionnaire. The multi-stage stratified cluster random sampling methods was applied to obtain study subjects in six areas (Nanchong, Jiangjin, Fengdu, Yunyang, Suining and Ya'an), which were selected for epidemiological investigation. Home visit completion of epidemiological questionnaires was conducted. The trained investigators guided the respondents to fill in the tinnitus epidemiological questionnaires, and the epidemiological status of six areas on prevalence and risk factor was investigated. SPSS 22.0 software was used for statistical analysis. Results: Sampling population were 10 289, in which 9 273 were valid questionnaires. There were 4 281 males and 4 992 females, with an average age of 47.3 years, among which 34.83% (3 230/9 273) had tinnitus. 3.99% (370/9 273) were diagnosed with bothersome tinnitus. In a multivariable logistic regression mod, the following factors were associated with onsetting of tinnitus: sleep disorder [Odds Ratio(OR)=3.74] and noise exposure(OR=1.99). The risk of disease was lowest in the age of 30-40 years old, while the risk of disease was higher for people under 30 and over 40. In another multivariable logistic regression mode, the following factors were associated with having bothersome tinnitus: older people were more likely to suffer from tinnitus, sleep disorders (OR=4.68) and noise exposure (OR=1.56). Conclusions: The prevalence of tinnitus in Sichuan and Chongqing is about 34.83%, but most of the tinnitus is short-lived and has low loudness, which will not affect the patients. Only a small number of patients with tinnitus (3.99%) persist and affect their health and need treatment. The occurrence and exacerbation of tinnitus may be related to sleep, age, and noise exposure.

Photoprotection according to skin phototype and dermatoses: practical recommendations from an expert panel

Increasing evidence on the impact of the different wavelengths of sunlight on the skin demonstrates the need for tailored recommendations of sunscreen according to skin phototype and dermatoses, which is now possible due to advances in the filters and formulations of sunscreens. A selective literature search was performed by an international expert panel, focusing on the type of sunscreen to recommend for photoaging, skin cancers, photodermatoses, pigmentary disorders and skin inflammatory disorders. Protection against ultraviolet (UV)B is especially important for light skin as there is a high risk of sunburn, DNA damage and skin cancers. Darker skin may be naturally better protected against UVB but is more prone to hyperpigmentation induced by visible light (VL) and UVA. Protection against UVA, VL and infrared A can be helpful for all skin phototypes as they penetrate deeply and cause photoaging. Long‐wave UVA1 plays a critical role in pigmentation, photoaging, skin cancer, DNA damage and photodermatoses. Adapting the formulation and texture of the sunscreen to the type of skin and dermatoses is also essential. Practical recommendations on the type of sunscreen to prescribe are provided to support the clinician in daily practice.

[Mutation analysis and prenatal diagnosis of MYO7A gene in a case of Usher syndrome type 1]

Objective: To analyze the clinical characteristics and identify the causative gene of a case with congenital deafness. Methods: Detailed medical history and clinical examination of a 4-year-old male child with congenital deafness were conducted in the First Affiliated Hospital of Army Military Medical University in June 2016. He was diagnosed with sensorineural deafness. The venous blood of the child and his parents was drawn, and genomic DNA was extracted. Proband's DNA was performed with targeted capture of high-throughput sequencing, then Sanger sequencing was used to verify the suspected mutation and segregation in this pedigree. According to the genetic diagnosis of the proband's deafness, ophthalmic examinations were performed. Genetic prenatal diagnosis was performed when the proband's mother was pregnant again. Results: The patient was detected with p.Trp1466Ter/p.Tyr2042Ter compound heterozygous mutations of MYO7A gene with targeted high-throughput sequencing. The mutation of p.Trp1466Ter was a reported mutation, while p.Tyr2042Ter has not been reported. In addition to congenital deafness, retinitis pigmentosa was also found by ophthalmologic examination, and the patient was clinically diagnosed with Usher syndrome type 1. Amniocentesis and fetal DNA sequencing were performed on the repregnancy fetus of this family at 18 weeks of gestation. The heterozygous mutation of MYO7A gene p.Tyr2042Ter was found, and the other allele was the wild type, indicating that the child will not exhibit clinical manifestations of Usher syndrome type 1. Indeed, the second child passed neonatal hearing screening. Conclusions: The clinical features and genetic variants were delineated in this family with Usher syndrome type 1. The results of the current study have enriched the phenotype and genotype data of the disease and provided a basis for genetic counseling.

Second-phase validation study of an alternative developmental toxicity test using mouse embryonic stem cell-derived embryoid bodies

The embryoid body test (EBT) is a developmental toxicity test method that measures the size of embryoid bodies (EBs) and the viability of mouse embryonic stem cells (mESCs) and fibroblasts (3T3 cells). The previous pre-validation study confirmed the high accuracy (above 80%) of EBT using 26 coded test chemicals. This second-phase validation study assessed the inter-laboratory reproducibility (5 chemicals in common) and predictive capacity (10 chemicals in each laboratory) test using the coded test chemicals at three laboratories. For the prediction model, the accuracy is increased when more data is accumulated. Therefore, we updated the prediction model and analyzed the results of the second year with the newly created-prediction model. Statistical analysis of the inter-laboratory reproducibility test results indicated that accuracy, sensitivity, and specificity were 87%, 78%, and 100%, respectively. The results of the statistical analysis of the predictive capacity test showed an accuracy of 80%, sensitivity of 78%, and specificity of 81%. In conclusion, the EBT can accurately classify various embryotoxicants within a short period and with relatively little effort. Therefore, EBT can be used as a good way to test developmental toxicity.

Comparison of the difference between income quintiles with the slope index of inequality

Background

The difference between income quintiles in health is relatively well accepted by the general public as a measure of health inequality. However, the slope index of inequality (SII) in health reflects the patterns of all social groups, including the middle 60%, and it could therefore be considered more academically desirable. If these two measures are closely correlated, the widespread use of the difference between income quintiles in health would be better supported. This study was conducted to compare differences between income quintiles in life expectancy (LE) and healthy life expectancy (HLE) with the SII.

Methods

Data on LE and HLE by income quintile from all 252 subnational districts of Korea were obtained using the National Health Information Database of the National Health Insurance Service and the Korea Community Health Survey. The SII was estimated with linear regression analysis, and Pearson correlation coefficients between differences between income quintiles and the SII were computed.

Results

The correlation coefficients between differences between income quintiles and the SII were generally high: 0.97 (95% CI: 0.96-0.98) for LE in men and women combined and 0.96 (95% CI: 0.94-0.97) for HLE in men and women combined. In most districts, the SII was greater than the difference between income quintiles.

Conclusions

Differences between income quintiles were closely correlated with the SII. The widespread use of differences between income quintiles in health as a measure of health inequality may be preferable for communicating results of health inequality measurements to the public.

Key messages

Differences in life expectancy and health life expectancy between income quintiles were closely correlated with the slope index of inequality in life expectancy and healthy life expectancy. The widespread use of differences between income quintiles in health as a measure of health inequality may be preferable for communicating results of health inequality measurements to the public.

Suicide mortality and its income-based inequalities in Korea, 2005-2017

Backgrounds

The suicide mortality rate in Korea has been the highest in the Organization for Economic Co-operation and Development countries between 2003 and 2016. The trends of suicide mortality and its inequalities according to socioeconomic positions provide important information in establishing suicide prevention policies. This study investigated trends in suicide mortality and its income-based inequalities in Korea between 2005 and 2017.

Methods

Data from 2005-2017 National Health Insurance Database individually linked with cause-of-death data of Statistics Korea were employed. A total of 164,412 suicidal deaths from 574,610,162 subjects aged 10 or over were analyzed. Age-standardized suicide mortality rates were calculated by the calendar year, sex, and income quintiles. The slope index of inequality was calculated as an absolute measure for inequality and relative index of inequality was used as a relative inequality measure.

Results

The suicide mortality in Korea increased from 29.3 per 100,000 in 2005 to 33.3 in 2011, then decreased to 23.1 in 2017. Suicide mortality rates in men were more than twice as high as the rates in women and the gender gap remained throughout the period. The lower income-level, the higher the suicide mortality rate, especially in men. The absolute inequality in suicide measured by the slope index of inequality has changed as the suicide mortality rate fluctuated, but the relative inequality in suicide has increased since 2012.

Conclusions

The suicide mortality in Korea has increased due to the global financial crisis and copycat suicide following celebrity suicides in 2008, but it has decreased since the paraquat ban in 2011-12. Despite the recent decline in suicide mortality, the gap between income quintiles did not change meaningfully during the study period. In particular, the magnitude of relative inequality has increased. Progressive national policies should be implemented to reduce suicide mortality and its income gaps.

Key messages

Despite the recent decline in suicide mortality in Korea, the income-based inequalities in suicide did not change meaningfully. The magnitude of relative inequalities has increased recently.

Enhancement of the stability of Mycobacterium tuberculosis recombinant antigen expressed in Escherichia coli using cell lysis additives

BACKGROUND

Mycobacteria tuberculosis (Mtb), the causative agent of tuberculosis, is a slow-growing bacterium. Expression in Escherichia coli is a widely used method for large-scale production of diagnostic antigenic recombinant proteins. Expression of Mtb antigen in E. coli offers a rapid and, inexpensive alternative to conventional protein synthesis from Mtb. The addition of stabilizing additives during cell lysis or storage of Mtb antigenic protein plays a vital role in enhancing antigen stability. In this study, we evaluated the effects of additives on the stability of Mtb antigens expressed in E. coli.

METHODS

Immunodominant Mtb antigens, i.e., CFP-10, Rv3872, TB7.7, and TB9.7, were cloned, and recombinant proteins overexpressed in E. coli were gradually degraded in a time-dependent manner by incubation at 37 °C. Various stabilizing additives during storage or cell lysis before protein purification were investigated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blot analysis.

RESULTS

CFP-10 and Rv3872 were mainly expressed in soluble form. The degraded form of the expressed protein after incubation at 37 °C was easily observed after 1 week. Increased stability was observed in a solution containing glycine for recombinant CFP-10 and Rv3872. TB9.7 was stable in a solution containing trehalose or mannitol. TB7.7 was stable in a solution containing sucrose, glycine, or polyethylene glycol.

CONCLUSION

Recombinant Mtb antigen stabilization using chemical additives inhibited protein degradation, leading to increased antigen stability and purification efficiency.

Assessment of neurotoxicity of pharmacological compounds during early neural development of human embryonic stem cells

Human embryonic stem cells (hESCs), with the potential for differentiation, have been used to evaluate the embryotoxicity of various compounds. The effects of pharmacological compounds (cytosine arabinoside, 5-fluorouracil, hydroxyurea, indomethacin, and dexamethasone) on neurogenesis of hESCs over 28 days were examined based on cytotoxicity (half-maximal inhibitory concentration of viability, IC₅₀) and expression of neural markers. Cytosine arabinoside, 5-fluorouracil, and hydroxyurea showed strong cytotoxicity (IC₅₀ < 10 μM), whereas indomethacin and dexamethasone had weaker cytotoxic effects. Dose-dependent expression profiles of neural markers in the compound-treated groups are presented in triangular charts to allow comparison with the standard expression levels in the control group. Differences in compound-specific reductions in expression patterns of GAD1, OLIG2, FABP, and NES were similar to the differences in cytotoxic strength. Cytosine arabinoside diminished nestin and β3-tubulin in neural differentiated hESCs. The results of this study extend the understanding of how differentiated hESCs may be useful for assessment of cell viability or neurogenesis impairment by chemicals that could have effects during the embryonic stage, particularly during neurogenesis.

[Association between IL-27 gene polymorphisms and susceptibility to allergic rhinitis]

Objective: To evaluate the potential association of IL-27 polymorphisms with allergic rhinitis(AR) in a Chinese Han population. Method:A case-control study was performed in 445 Chinese AR patients and 691 healthy controls. Three SNPs in the IL-27p28 gene, including rs153109, rs17855750 and rs181206, were detected using a polymerase chain reaction-restriction fragment length polymorphism assay(PCR-RFLP). Result:A significantly increased prevalence of the rs153109 TT genotype and the T allele was found in AR patients, while a decreased prevalence of the CT and CC genotypes and the C allele was found. For rs153109, the TT genotype and the T allele were significantly associated with the risk of AR, but the CT and CC genotypes and the C allele decreased the risk of AR; for rs17855750, the TT genotype and T allele were risk factors for AR, and the GT genotype and G allele provided protection. TTT and TTC haplotypes in the IL-27 p28 gene were positively correlated with AR, while CGT, CTC and CTT haplotypes were associated with a significantly decreased risk of AR. Conclusion:This study indicates that IL-27 p28 polymorphisms rs153109 and rs17855750 are likely involved in AR susceptibility, making them potentially useful genetic biomarkers for AR susceptibility in the Chinese Han population.

Posttraumatic myositis ossificans of the hand : A locally aggressive malignancy-mimicking tumor

Posttraumatic myositis ossificans (PTMO) is the most common form of myositis ossificans, but it rarely affects the hand. Due to the aggressive behavior of this unusual tumor, it is commonly misdiagnosed as malignancy or local infection. This report describes a case of PTMO of the hand in a 25-year-old women, and reviews the clinical, radiologic, and histologic characteristics. By understanding the disease characteristics and maturation process, physicians can avoid a misdiagnosis that may lead to functional impairment or improper treatment.

Alginate–marine collagen–agarose composite hydrogels as matrices for biomimetic 3D cell spheroid formation

We report a novel, customizable, transparent, biocompatible, functional, easy-to-produce, efficient and cost-effective AmCA scaffold for 3D cell culture.

In vivo time-sequential histological study focused on melanocytes: suggestion of golden time for intervention to prevent post-laser pigmentary changes

BACKGROUND

Post-inflammatory pigmentary changes after laser treatments are challenging adverse effect.

OBJECTIVE

To suggest an ideal time period with regard to intervention to prevent post-laser pigmentary changes, an in vivo time-sequential histological study focused on melanocytes was performed.

METHODS

The back skin of four volunteers was irradiated with Q-switched alexandrite laser (QSAL). In one subject (subject 4), topical corticosteroid was applied onto the irradiated skin from the time of irradiation to day 28. In all subjects, time-sequential skin biopsies were performed at baseline, an immediate time after irradiation, day 2, day 7, and day 28. Histological and immunohistochemical analyses were conducted.

RESULTS

Q-switched alexandrite laser led to the successful removal of pigments and most melanocytes from the epidermis in all subjects. At day 28, there was increased epidermal pigmentation in the skin of the subjects 1-3. It was noted that numerous activated melanocytes appeared on day 7, continued to be observed until day 28. However, in the subject 4, the melanocyte activation and post-laser pigmentary changes were not observed.

CONCLUSION

In regard to intervene melanocyte activation, at least 1 week after laser treatment is suggested as a 'golden' time period to prevent pigmentary changes.

Effect of Feeding Bacillus subtilis natto on Hindgut Fermentation and Microbiota of Holstein Dairy Cows

The effect of Bacillus subtilis natto on hindgut fermentation and microbiota of early lactation Holstein dairy cows was investigated in this study. Thirty-six Holstein dairy cows in early lactation were randomly allocated to three groups: no B. subtilis natto as the control group, B. subtilis natto with 0.5×10(11) cfu as DMF1 group and B. subtilis natto with 1.0×10(11) cfu as DMF2 group. After 14 days of adaptation period, the formal experiment was started and lasted for 63 days. Fecal samples were collected directly from the rectum of each animal on the morning at the end of eighth week and placed into sterile plastic bags. The pH, NH3-N and VFA concentration were determined and fecal bacteria DNA was extracted and analyzed by DGGE. The results showed that the addition of B. subtilus natto at either treatment level resulted in a decrease in fecal NH3-N concentration but had no effect on fecal pH and VFA. The DGGE profile revealed that B. subtilis natto affected the population of fecal bacteria. The diversity index of Shannon-Wiener in DFM1 decreased significantly compared to the control. Fecal Alistipes sp., Clostridium sp., Roseospira sp., beta proteobacterium were decreased and Bifidobacterium was increased after supplementing with B. subtilis natto. This study demonstrated that B. subtilis natto had a tendency to change fecal microbiota balance.

Effects of xenoestrogens on streptozotocin-induced diabetic mice

In diabetic mellitus, apoptotic or necrotic deaths of pancreatic β-cells lead to insulin deficiency because plasma insulin is synthesized and released from pancreatic β-cells and involved with blood glucose homeostasis. Since estrogen receptors have been related with glucose metabolis, estrogen-like chemicals (xenoestrogens) including bisphenol A (BPA) and octylphenol (OP) alter the endocrine system, and cause adverse health consequences such as obesity and diabetes. In the current study, levels of plasma glucose were evaluated after administration of BPA and OP using biochemical analysis, and were investigated in insulin and insulin synthesis-related genes in the pancreas and liver of streptozotocin (STZ)-induced insulin-deficient mice. Although the STZ-induced insulin-deficient groups showed an increase in blood glucose compared with control groups, the induced blood glucose level dropped to that of baseline after administration of xenoestrogens. When insulin level and mRNA expression of insulin transcriptional regulators (Pdx1, Mafa, and Neurod1) in pancreatic β-cells were decreased in STZ-induced insulin-deficient groups, they were significantly restored by administration of xenoestrogens. The latter observation is also related to NF-κB activation for anti-apoptosis effects in pancreatic β-cells. In addition, we observed a complementary convergence in regulation of gluconeogenesis for determination of blood glucose levels. Therefore, the current study may be particularly important for assessment of xenoestrogens under condition of diabetic mellitus or metabolic disorder.

Beneficial effects of judo training on bone mineral density of high-school boys in Korea

Bone mineralization is strongly stimulated by weight-bearing exercise during growth and development. Judo, an Olympic combat sport, is a well-known form of strenuous and weight-bearing physical activity. Therefore, the primary goal of this study was to determine the effects of Judo practice on the bone health of male high school students in Korea. The secondary goal of this study was to measure and compare the bone mineral density (BMD) of the hands of Judo players and sedentary control subjects. Thirty Judo players (JDP) and 30 sedentary high school boys (CON) voluntarily participated in the present study, and all of the sedentary control subjects were individually matched to the Judo players by body weight. BMD was determined by using dual-energy X-ray absorptiometry (Hologic, Bedford, MA, USA). The lumbar spine, femur and forearm BMD in the JDP group were significantly greater by 22.7%, 24.5%, and 18.3%, respectively, than those in the CON group. In addition, a significant difference in the CON group was observed between the dominant hand (DH) radius (0.710 ± 0.074 g/cm(2)) and the non-dominant hand (NDH) radius (0.683 ± 0.072 g/cm(2)), but this was not observed in the JDP group (DH = 0.819 ± 0.055 g/cm(2); NDH = 810 ± 0.066 g/cm(2)) (P < 0.05). Therefore, the results of this study suggest that Judo practice during the growth period significantly improves bone health in high school male students. In addition, it seems that Judo practice could eliminate the effect of increased BMD in the dominant hand.

Hypopigmented keratosis: is it a hyperkeratotic variant of idiopathic guttate hypomelanosis?

We have occasionally seen patients with acquired well-demarcated, scattered hypopigmented papules. In this study, we investigated the clinical and histopathological characteristics of such lesions. Biopsies were taken from the lesional and perilesional normal skin from 10 of 13 patients, which were compared with 10 idiopathic guttate hypomelanosis (IGH) samples. The lesions were scattered, well-circumscribed, flat-topped, hypopigmented papules. There was no age or gender predilection. Marked hyperkeratosis was present, with clear-cut margins distinguishable from the adjacent normal epidermis. The melanin content was decreased in the lesional epidermis, which was associated with a decrease in expression of melanogenesis-associated markers such as tyrosinase and NKI/beteb (marker of gp100) and reduction in the number of melanocytes. These histological findings were similar to those of IGH except for the additional finding of a thicker stratum corneum in this case seem to represent a 'hyperkeratotic' variant of IGH.

Acquired bilateral melanosis of the neck in perimenopausal women

BACKGROUND

Acquired bilateral patchy or mottled pigmentation of the neck has occasionally been observed.

OBJECTIVE

To investigate the clinical and histopathological characteristics of this pigmentation.

METHODS

Fourteen patients were included in the study. Patch and photopatch tests, and laboratory tests including serum hormonal evaluation were performed. Skin biopsies were performed on lesional skin and perilesional normal skin.

RESULTS

All the patients were women and all were perimenopausal. The lesions were characterized by bilateral, symmetrical, brown-to-grey patchy or mottled pigmentation on the lateral neck. There were positive photopatch results in some cases, but their relevance was doubtful. All laboratory findings were within the normal ranges. The histological findings showed marked accumulation of pigment in the dermis with perivascular lymphocytic infiltration. A significantly higher expression of melanogenesis-associated proteins and an increased number of melanocytes were observed in the epidermis of the lesional skin. The melanin-bearing cells in the dermis were stained with factor XIIIa or CD68, but the majority of these cells were identified as factor XIIIa+ dermal dendrocytes. Some brown pigments were mixed with light brown or golden brown pigment that was positive in iron staining.

CONCLUSIONS

These cases seem to represent a continuum of Riehl melanosis. However, the principal distribution of the pigmentation is a distinguishing feature. Any consistent predisposing factors were not established, but there may be a role for subclinical injury or inflammation as possible causative factors for development of the pigmentation.

Translationally controlled tumour protein is associated with podocyte hypertrophy in a mouse model of type 1 diabetes

AIMS/HYPOTHESIS

Translationally controlled tumour protein (TCTP) is thought to be involved in cell growth by regulating mTOR complex 1 (mTORC1) signalling. As diabetes characteristically induces podocyte hypertrophy and mTORC1 has been implicated in this process, TCTP may have a role in the pathogenesis of diabetes-induced podocyte hypertrophy.

METHODS

We investigated the effects and molecular mechanisms of TCTP in diabetic mice and in high glucose-stimulated cultured podocytes. To characterise the role of TCTP, we conducted lentivirus-mediated gene silencing of TCTP both in vivo and in vitro.

RESULTS

Glomerular production of TCTP was significantly higher in streptozotocin induced-diabetic DBA/2J mice than in control animals. Double-immunofluorescence staining for TCTP and synaptopodin revealed that podocyte was the principal cell responsible for this increase. TCTP knockdown attenuated the activation of mTORC1 downstream effectors and the overproduction of cyclin-dependent kinase inhibitors (CKIs) in diabetic glomeruli, along with a reduction in proteinuria and a decrease in the sizes of podocytes as well as glomeruli. In addition, knockdown of TCTP in db/db mice prevented the development of diabetic nephropathy, as indicated by the amelioration of proteinuria, mesangial expansion, podocytopenia and glomerulosclerosis. In accordance with the in vivo data, TCTP inhibition abrogated high glucose-induced hypertrophy in cultured podocytes, which was accompanied by the downregulation of mTORC1 effectors and CKIs.

CONCLUSIONS/INTERPRETATION

These findings suggest that TCTP might play an important role in the process of podocyte hypertrophy under diabetic conditions via the regulation of mTORC1 activity and the induction of cell-cycle arrest.

Defective barrier function in melasma skin

BACKGROUND

Melasma is characterized by increased pigmentation and photodamaged features, which include solar elastosis. Recently, we detected the downregulation of the genes most associated with lipid metabolism using microarray analysis in melasma. These findings suggested that lesional skin may have different biophysical characteristics, and, in particular, an altered skin barrier function.

OBJECTIVE

To determine the cutaneous biophysical characteristics of melasma.

METHODS

The melanin index, erythema index, stratum corneum hydration, sebum content and transepidermal water loss (TEWL) were measured for lesional and perilesional normal skin of 16 melasma patients and then compared. In addition, a skin biopsy was performed on 11 of the 16 study subjects to measure stratum corneum thickness and to study the protein expressions of PPAR-α and ALOX15B.

RESULTS

Melanin index, erythema index and stratum corneum hydration were significantly higher in lesional skin than in perilesional normal skin. No significant difference was found between lesional and normal skin in terms of basal TEWL level or sebum content. However, the rate of TEWL after barrier perturbation was significantly higher for lesional skin, and the barrier recovery rate was significantly delayed. Furthermore, a trend towards thinned stratum corneum was observed for lesional skin, and this was correlated with barrier recovery rate. The expressions of PPAR-α and ALOX15B were variable in the samples.

CONCLUSIONS

Melasma skin is characterized by impaired stratum corneum integrity and a delayed barrier recovery rate.

Immunohistochemical expression of matrix metalloproteinases in the granulomatous rosacea compared with the non-granulomatous rosacea

BACKGROUND

There is a granulomatous variant which is recognized in the rosacea spectrum. However, the pathogenesis of granuloma formation in rosacea has not been clearly demonstrated. Matrix metalloproteinases (MMPs) are required for recruitment of inflammatory cells and for tissue remodelling, making way for the development of well-organized granuloma.

OBJECTIVE

The aim of this study was to investigate the expression of transforming growth factor (TGF)-β, TGF-β type II receptor (TβRII), Tumour necrosis factor (TNF)-α, MMP-1, 2 and 9 in the granulomatous rosacea (GR) compared with the non-granulomatous rosacea (NGR) and test the hypothesis that the changes of these profiles in GR would be related with chronic ultraviolet radiation (UVR)-exposure.

METHODS

Facial skin samples were obtained from 20 patients with GR and NGR (control group). The sections were stained using haematoxylin and eosin, Verhoeff's elastic stain, and antibodies to TGF-β, TβRII, TNF-α, MMP-1, -2 and -9.

RESULTS

The amount of elastotic material was significantly increased in the dermis of GR lesions. Expression of TGF-β was significantly decreased in the epidermis of GR lesions compared with NGR lesions. In addition, the expression of MMP-9 was significantly increased in the dermis of GR lesions compared with NGR lesions, especially at the centre of the granuloma on a semi-quantitative analysis. MMP-2 expression was also increased in GR lesions, although the difference between the two groups was not statistically significant.

CONCLUSIONS

The results of this study suggest that the increased expression of MMPs in the dermis may participate in granuloma formation of GR in association with UVR.

Acquired bilateral naevus of Ota-like macules: an immunohistological analysis of dermal melanogenic paracrine cytokine networks

BACKGROUND

Acquired bilateral naevus of Ota-like macules (ABNOM) is similar to melasma with regard to their clinical features, including female predominance, acquired onset, and predominant involvement of the malar area. The similar clinical features suggest the possibility of a shared pathogenesis. Dermal factors including vascularity and melanogenic paracrine networks such as the stem cell factor (SCF)/c-kit pathway have recently been suggested to play an important role in the pathogenesis of melasma. However, the role of dermal factors in ABNOM remains unknown.

OBJECTIVES

To provide a novel view on the pathogenesis of ABNOM, we studied the expression of melanogenic paracrine cytokines such as SCF/c-kit, and assessed dermal vascularity.

METHODS

Thirty-seven patients with ABNOM and 20 patients with melasma were enrolled in this study. Skin samples were obtained from lesional and perilesional normal skin. Immunohistochemistry was performed.

RESULTS

Solar elastosis was slightly more intense in the lesional skin of ABNOM. In contrast to dermal pigmentation and melanocytes, the amounts of epidermal pigmentation and melanocytes were not increased in the lesional skin of patients with ABNOM. The expression of dermal SCF and c-kit was increased; however, the expression of epidermal SCF and c-kit and dermal factor VIII-related antigen was not increased in the lesional skin of ABNOM.

CONCLUSIONS

These results suggest that the increased expression of the SCF/c-kit pathway between dermal fibroblasts and dermal melanocytes may play an important role in the pathogenesis of ABNOM.

Time interval to conversion of interferon-gamma release assay after exposure to tuberculosis

The proper interval for repeating an interferon-γ release assay (IGRA) among tuberculosis contacts with initially negative results is unknown. The interval for IGRA conversion after exposure to patients with active pulmonary tuberculosis in an outbreak setting was evaluated. In a platoon of 32 soldiers, four active pulmonary tuberculosis patients, in addition to one index patient, were diagnosed during a contact investigation. For the other 27 contacts, a tuberculin skin test (TST) and QuantiFERON® TB-Gold In-Tube (QFT-GIT) assay were performed. For soldiers with a negative result on the initial QFT-GIT assay, the test was repeated at 2, 4, 8, 14, 18 and 30 weeks until positive conversion occurred. When conversion was identified, the subject was treated for latent tuberculosis infection. Initially, 17 (63.0%) soldiers gave positive QFT-GIT results, whereas 21 (77.8%) showed positive TST results. Among 10 participants with initially negative QFT-GIT results, three showed conversion at 2 weeks, three at 4 weeks and three at 14 weeks. Conversion did not occur during the 30-week observation period in one contact. Based on the tuberculosis exposure time-points among the contacts, IGRA conversion generally occurred 4-7 weeks after exposure, although it could occur as late as 14-22 weeks after exposure.

Bioprocessing papaya processing waste for potential aquaculture feed supplement--economic and nutrient analysis with shrimp feeding trial

Papaya processing waste (PPW), a major fruit processing waste in the Hawaii islands, served as substrate for yeast (Saccharomyces cerevisiae) growth. The fermented PPW products containing nutrients of 45% crude protein and various fat, fiber, lignin, cellulose, and minerals were advantages to nutrients of yeast alone. Three experimental diets controlled at 35% protein formulation containing different levels of inclusion of PPW products and a commercial control diet were fed to shrimps for 8 weeks. The 50% inclusion of PPW diets were comparable to commercial feed in weight, growth, feed conversion ratio (FCR) and survival rate. Such bioprocess treatment system would be economically feasible with the control of annual cost and increase of the amount of PPW treated. The selling price of PPW products and annual operation and maintenance cost were the most influential factors to additional profits. This study presented a promising alternative for environmental-friendly treatment of organic wastes as well as the sustainability of local agriculture and aquaculture industries.

Production of intergeneric hybrid between dwarfing polish wheat (Triticum polonicum L.) and Aegilops tauschii Cosson. with reference to wheat origin

Dwarfing polish wheat is a dwarfing accession of Triticum polonicum L. from Xinjiang of China. In the present study, the artificial hybridization between dwarfing polish wheat and two accessions of Aegilops tauschii Cosson. (AS60 and AS65) was carried out, and the F1 hybrids were obtained successfully without using embryo rescue techniques for the first time. The crossabilities of hybrids T. polonicum x Ae. tauschii (AS60) and T. polonicum x Ae. tauschii (AS65) were 1.67% and 0.60% respectively. Only the hybrids of T. polonicum x Ae. tauschii (AS60) germinated well, and 24 Fl hybrid plants were obtained. All the F1 hybrid plants grew vigorously, and the morphological traits were similar to bread wheat. The F1 plants had some obvious traits inherited from T. polonicum and Ae. tauschii and were completely sterile. Chromosome pairing in the hybrid was characterized by a large number of univalents, with an average of 20.56 and 0.22 bivalents per PMC, and no ring bivalents and multivalents were observed. Furthermore, the potential value of the F1 hybrids between T. polonicum and Ae. tauschii for studying wheat origin and breeding are discussed.

Hypoglycemic and hypolipidemic effects of the total triterpene acid fraction from Folium Eriobotryae

For seeking the good natural material to develop new agent to treat diabetes, the total triterpene acid (TTA) fraction extracted from Folium Eriobotryae [leaves of Eriobotrya japonica (Thunb.) Lindl.] was evaluated for its hypoglycemic and hypolipidemic potential through normal, alloxan and streptozotocin-induced diabetic mice administered with graded oral doses (100, 200, 300 mg/(kg day)) for 7 or 14 days. The results showed that a dose of 300 mg/kg of TTA is the most effective dose to cause significant (p<0.01) hypoglycemic and/or hypolipidemic effects on normal, alloxan and streptozotocin-induced diabetic mice. This dose also significantly (p<0.01) lowered the glycosylated serum protein (GSP), total cholesterol (TC) and triglyceride (TG) level in severely diabetic mice. Furthermore, TTA increased the superoxide dismutase activity (SOD) and the serum insulin level of diabetic mice. These evidences indicated that the total triperpene acid fraction from Folium Eriobotryae has a high anti-diabetic potential along with a good hypolipidemic profile.

Association of tri-nucleotide (CAG and GGC) repeat polymorphism of androgen receptor gene in Taiwanese women with refractory or remission rheumatoid arthritis

We investigated the relationship between CAG and GGC repeat polymorphism of the androgen receptor (AR) gene and rheumatoid arthritis (RA) in female patients with different disease subtypes. This case-control study enrolled 215 women in three groups: RA patients refractory to standardized therapy (n = 51); RA patients at complete remission phase (n = 60); and healthy controls (n = 104). CAG and GGC repeat lengths were determined by automated fluorescence-based DNA fragment-sizing method. Demographic data, allele lengths, allele distribution, and zygosity status of CAG/GGC repeats were assessed for the three groups. Refractory RA patients tend to have a significantly younger onset age of RA and more elevated erythrocyte sedimentation rates than do remission RA patients. Mean and median values of CAG and GGC repeat lengths are similar in both RA and control patients. However, RA patients harboring any long CAG alleles with more than 23 repeats had an increased risk of a refractory course, whereas differences in risk were not observed between these patients and RA subtypes harboring any long GGC alleles with more than 16 repeats. In addition, the homozygous frequency of CAG but not GGC alleles was lower in refractory RA than in remission RA patients or in controls (p = 0.042). Neither CAG nor GGC repeat lengths had a significant relationship with rheumatoid factor reactivity. Our observations indicate that short CAG repeats of the AR gene with higher transactivation activity may have protective effects against refractory course of RA development and that homozygous frequency of CAG alleles may be involved in the disease remission subtype. In contrast, lack of association of GGC polymorphism and RA was also observed. Together, these data imply that CAG but not GGC alleles in the AR polymorphism may play an important role in modulating the disease pattern of RA among Taiwanese women.

FK506 increases pigmentation and migration of human melanocytes

BACKGROUND

Topical tacrolimus (FK506) is a potential therapeutic option for vitiligo management. Despite its clinical efficacy, the underlying mechanism of how topical tacrolimus induces repigmentation in vitiligo has scarcely been investigated.

OBJECTIVES

To investigate the direct effects of FK506 on pigmentation and migration of human melanocytes.

METHODS

Cell proliferation was measured using a Coulter counter. The effects on pigmentation were investigated by measuring melanin contents, tyrosinase activity and tyrosinase expression. To determine the effects of FK506 on cell migration, we performed scratch assays and Boyden chamber assays.

RESULTS

FK506 treatment increased melanin contents, although there was an inhibitory effect on growth of melanocytes. The increase of pigmentation was due to the result of the stimulatory action of FK506 on tyrosinase activity and its expression, which eventually led to melanin biosynthesis. Furthermore, cell migration was enhanced by FK506 treatment.

CONCLUSIONS

These findings provide in vitro evidence demonstrating direct effects of FK506 on pigmentation and melanocyte migration and may provide a possible mechanism for the effect of tacrolimus in vitiligo.

The dermal stem cell factor and c-kit are overexpressed in melasma

BACKGROUND

The pathogenesis of melasma has not yet been clearly demonstrated. We tried to determine whether the stem cell factor (SCF) and its receptor c-kit are involved in the mechanism of hyperpigmentation of melasma because this factor is highly implicated in the stimulation of melanocyte function in vitro and in vivo.

OBJECTIVES

The present study was conducted to investigate the expression of SCF and c-kit on the lesions of melasma compared with nonlesional skin.

PATIENTS/METHODS

Skin samples were obtained from lesional and nonlesional facial skin of 60 Korean women with melasma. Immunohistochemistry and reverse transcriptase-polymerase chain reaction (RT-PCR) analysis was performed to determine the expression of SCF and c-kit in melasma.

RESULTS

The expression of SCF was significantly increased at the lesional dermis compared with nonlesional dermis. However, there was no significant difference in the expression of SCF in lesional and nonlesional epidermis. The expression of c-kit was significantly increased at lesional epidermis compared with nonlesional skin. RT-PCR of SCF and c-kit mRNAs demonstrated increased expression of both types of transcripts in the lesional skin compared with nonlesional skin.

CONCLUSIONS

These results suggest that the increased expression of SCF in the dermis and of c-kit in the epidermis play an important role in the mechanism of hyperpigmentation in melasma.

Expression and function of peroxisome proliferator-activated receptors in human melanocytes

BACKGROUND

Peroxisome proliferator-activated receptors (PPARs) belong to the superfamily of nuclear receptors that heterodimerize with the retinoic X receptor. Agonists of PPAR have been known to play an important role in cellular responses including proliferation and differentiation. The expression and function of PPARs have not been investigated in human melanocytes, although they have been widely demonstrated in keratinocytes of the skin.

OBJECTIVES

To investigate the expression of PPARs in human melanocytes and the effects of PPAR activators on melanocyte growth and melanogenesis.

METHODS

We used immunocytochemistry and Western blot analysis to determine whether PPARs are expressed in melanocytes. To investigate further expression of PPAR subtypes, reverse transcriptase-polymerase chain reaction analysis was performed using PPAR subtype-specific oligonucleotides. The cell proliferation was measured using the Coulter counter. The effects on pigmentation were investigated with measurement of melanin contents, tyrosinase activity and its expression.

RESULTS

The mRNA of all three PPAR subtypes, PPAR-alpha, PPAR-beta/delta and PPAR-gamma, were expressed in melanocytes. Activators for PPAR-alpha (WY-14643) and PPAR-gamma (ciglitazone) inhibited proliferation of melanocytes in a dose-dependent manner, whereas bezafibrate, a preferential activator for PPAR-beta/delta, had no effect. This growth inhibition was accompanied by the morphological change of the melanocytes to an activated form with an increased number of dendrites and enlarged cell area compared with the control. The WY-14643 and ciglitazone also appeared to stimulate the melanin synthesis of melanocytes. This increase in pigmentation was due to stimulation of the tyrosinase activity without an increase in the expression of tyrosinase.

CONCLUSIONS

PPARs are expressed in human melanocytes and PPAR-alpha and PPAR-gamma activators inhibit melanocyte growth and stimulate melanogenesis.