[A case-control study on the relationship between DNA methylation and occupational noise hearing loss]

Objective: To explore the relationship between DNA methylation and occupational noise-induced hearing loss. Methods: A case-control study was conducted. People with hearing loss induced by occupational noise were recruited as the case group and those with normal hearing but still exposed to occupational noise were recruited as the control group. A total of 60 participants were included, of which 30 participants were in the case group and 30 in the control group. The methylation level was detected by 850k genome-wide DNA methylation chip technology. The significance of differential methylated position (DMP) was tested by R-packet 'Champ'. The differential methylated region (DMR) was analyzed by using Champ's Bumphunter algorithm. Cluster profiler was used to analyze the gene list for GO and KEGG pathway enrichment. Results: There was significant difference between two groups in binaural high-frequency average hearing threshold (P<0.05), but there was no significant difference in age, smoking, drinking, hypertension, physical exercise and cumulative noise exposure. The results of DMP and DMR analysis showed that 713875 sites were detected in the case group and the control group, and 439 methylation sites with significant difference, accounting for 0.06%; 650 regions were detected, and 72 methylation regions with significant differences, accounting for 11.08%. Compared with the control group, the results of GO enrichment analysis showed that the case group had statistically significant differences in four pathways: axogenesis of projection neurons in the central nervous system, neuronal development in the central nervous system, axogenesis of neurons in the central nervous system and neuronal differentiation in the central nervous system. KEGG enrichment analysis showed that there were significant differences in sphingolipid metabolism, aldosterone synthesis and secretion, primary bile acid biosynthesis pathway between the case group and the control group. Conclusion: The occurrence of occupational noise-induced hearing loss may be related to the regulation of gene expression related to axogenesis of projection neurons in the central nervous system, development of neurons in the central nervous system, axogenesis of neurons in the central nervous system, differentiation of neurons in the central nervous system, sphingolipid metabolism, aldosterone synthesis and secretion, primary bile acid biosynthesis and gene methylation related to metabolism.

How to deal with the transmission of SARS-COV-2 on the surface of Cold-chain foods to people: a review

OBJECTIVE

The outbreak of SARS-CoV-2 in 2020 has become the world's largest public health event, causing global attention and concern. Despite national efforts to control this emerging infectious disease, it still cannot be contained. China, which reported the disease early, was able to control the outbreak quickly, but there is the problem of imported infections abroad. This review aims to summarize SARS-CoV-2 detected on the outer packaging of imported cold chain food and lead to the transmission of novel coronavirus.

MATERIALS AND METHODS

We reviewed information on SARS-COV-2 detected on the outer packaging of imported cold chain food and relevant literature.  We searched the following databases: PubMed, Web of Science, EMBASE and CNKI. search terms were "2019 nCoV", "SARS-CoV-2", "COVID-19", "cold-chain", "item surface", "spread", "people".

RESULTS

We found that SARS-CoV-2 survives on the surface of cold-chain food for a long period of time and these active viruses can be transmitted to humans.

CONCLUSIONS

We believe that while strictly preventing and controlling the importation of infected patients, we should strengthen the management of imported cold-chain food and its workers to prevent the transmission of SARS-CoV-2 to humans on the surface of cold-chain food objects.

[Analysis on the effect of sound insulation reconstruction in operation room of steel rolling production line in a steel plant]

Objective: To investigate the effect of sound insulation improvement on the noise exposure of workers in the operation room of hot rolling line for wide and heavy plate. Methods: From September 2019 to September 2017, based on the occupational health Survey, the data of 25 fixed operation rooms and workers in operation rooms of a steel rolling production line were collected retrospectively, the noise exposure levels before and after the improvement of sound insulation were statistically analyzed. Results: The noise exposure value of the workers, the qualified rate of 0 Grade 8 hours equivalent noise (L(EX, 8 h)) ≤85 dB (A) and the qualified rate of the design limit value of the operation room were all higher than those before the modification, the difference was statistically significant (P<0.01) , after the renovation, the Class II and above noise hazards were eliminated, the equivalent continuous a sound level (L(Aeq, 8 h)) >75 dB (A) of the workers in the operation room was 8h, and the noise level in the operation room still did not meet the Ergonomics limit standard. Conclusion: The improvement of sound insulation can effectively improve the working environment of noise workplace operating room and reduce the workers'noise exposure level.

[Prediction of KCNQ4gene polymorphism varies with CNE or noise exposure duration on the Risk of NIHL-Cox model analysis based on cohort study]

Objective: The purpose of this study was to explore the association between gene in the potassium recycling pathway 4 (KCNQ4) polymorphisms and the susceptibility to noise-induced hearing loss (NIHL) , and analysis the effect of cumulative noise exposure (CNE) and noise exposure duration on this association. Methods: A nested case-control study with 1∶1 matched was used based on the cohort of noise exposure in a steel factory. A total of 286 cases were selected as the group of hearing loss and 286 controls were chosen according to the matching standards of same gender, same type of work, age difference ≤ 5 years, noise exposure duration ≤ 2 years. The single nucleotide polymorphisms (SNPs) of rs4660468, rs4660470, rs34287852 in KCNQ4 were genotyped by SNPscan(TM) method. The codominant, dominant and recessive models were established to study KCNQ4 polymorphisms and the susceptibility to NIHL by single-factor conditional logistic regression analysis. The COX regression analysis was used to analyze the risk of developing NIHL in individuals with different genotypes along with the extending of noise exposure duration or CNE. Results: In the case of CNE≤96 dB (A) ·year, the risk of developing NIHL in individuals with TA genotype of rs4660470 was 2.197 times than individuals with TT genotypes (95%CI: 1.032~4.677) , and those with TA+AA and TT genotypes (HR=2.467, 95%CI: 1.025~5.934) With the increase of noise exposure duration, in rs4660470, individuals with TA genotype had a higher risk of suffering NIHL than those with TT genotype (HR=1.461, 95%CI: 1.061~2.011) , individuals with TA and/or AA genotype had a earlier risk of suffering NIHL than those with TT genotype. Conclusion: The mutant allele A of rs4660470 in KCNQ4 may be a risk factor for developing NIHL, CNE≤100 dB (A) ·year or the increase of noise exposure duration may further increase the risk of NIHL.

[Association between PON2 gene polymorphisms and susceptibility to noise-induced hearing loss]

Objective: To investigate the relationship between SNP and noise-induced hearing loss (NIHL) susceptibility in occupational noise exposure population in China. Methods: From 6297 for a certain steel works in contact with noise, contact length of 3 years or more and workplace noise exposure intensity of 80 dB (A) , ears or high frequency (3 000, 4 000, 6 000 Hz) average of hearing acuity 40 dB (HL) , or high frequency loss in both ears, on the basis of single whisper frequency (500, 1, 000, 2 000 Hz) average threshold of 26 dB (HL) or object as case group. A case-control study was designed with 1:1 matching. Subjects with the same gender, the same type of work, age ±5 years old, and working age ±2 years after noise exposure were selected as the control group. Subjects with any whisper frequency (500, 1, 000, 2, 000 Hz) whose hearing threshold in any frequency band was ≤25 dB (A) and whose average high-frequency hearing threshold in pure tone hearing test was <35 dB (A) were selected as the control group. Four sites of PON2 gene were genotyped by medium-and high-throughput SNP genotyping. Univariate logistic regression was used to analyze the relationship between single SNP polymorphism and NIHL. Results: A total of 286 case-control pairs were included. Smoking was statistically significant difference between cases and controls (P<0.001) . Conclusion: No statistical difference has been found between single SNP polymorphism and NIHL. At the level of greater than 92 dB of high noise exposure, rs7785846 (CT+TT) genotype is a risk factor for occupational noise deafness, and its OR is 2.74 (95%CI: 1.09-6.89) compared with wild homozygous type (CC) . Conclusion. The rs7785846 (CT+TT) genotype carriers of PON2 gene are more susceptible to hearing impairment when exposed to high noise intensity.

[Association between GSTP1 gene polymorphisms and susceptibility to noise-induced hearing loss]

Objective: To investigate the association between the single nucleotide polymorphisms (SNPS) at rs1695 and rs6591256 in glutathione S-transferase P1 (GSTP1) gene and susceptibility to noise-induced hearing loss in Chinese Han workers exposed to noise. Methods: Using the 1: 1 nested case-control study and taking 6297 workers exposed to noise in a steel plant in Henan province as the cohort study population in July 2019, we screened those who have been exposed to noise for ≥3 years and whose binaural high frequency (3000, 4000, 6000 Hz) average hearing threshold is ≥40 dB (A) into the case group. The control group was selected according to the matching criteria of the same sex, same type of work, and the age difference was not more than 5 years old, and the working age difference was not more than 2 years. 276 subjects were selected into the case group and the control group respectively. The medium and high throughout single nucleotide polymorphism typing technology (SNPscanTM technology) was used to detect the polymorphism of three nucleotide sites of GSR gene, and conditional logistic regression was used to analyze the relationship between single nucleotide polymorphism (SNP) and NIHL, and the relationship between different polymorphic sites and the risk of NIHL after adjusting covariates. After stratification with different cumulative noise exposure (CNE) , Conditional logistic regression analysis was used to analysis the risk of NIHL at different loci. Results: The mean and standard deviation of age of the selected subjects was (40.28±8.00) , the mean and standard deviation of noise-exposed working years was (18.7±8.92) years. The range of noise exposure levels and comulative noise exposure were 80.05-93.35dB (A) and 86.83-107.92 dB (A) ·year, respectively. Compared with the control group, there were no statistically significant differences in age, noise-exposured working years, intensity of noise exposure, CNE, gender, drinking, hypertension prevalence and noise exposure level in the hearing loss group (P>0.05) , while there were statistically difference in smoking, binaural high-frequency average hearing threshold and binaural speech frequency (P<0.05) . After adjusting for smoking, drinking, hypertension and other factors, in the co-dominant model, compared with GGgenotype, the risk of NIHL was higher in rs1002149 GT genotype and rs2251780 GA genotype (OR=1.558, 95%CI: 1.028-2.361; OR=1.550, 95%CI: 1.020-2.355, P<0.05) ; compared with TT/GT genotype, the rs1002149 TT genotype has a higher risk of developing NIHL (OR=1.494, 95%CI: 1.002-2.228, P<0.05) , while rs3779647 genotype had no relationship with the risk of NIHL (P>0.05) . In the equivalent sound level (L(Aeq)) of noise >85 dB (A) stratification, compared with GG genotype, carrying rs1002149 GT genotype and rs2251780 GT genotype has higher risk of nihl (OR=1.801, 95%CI: 1.093-2.967; OR=1.720, 95%CI: 1.050-2.817, P<0.05) . Haplotype analysis of two sites, rs1002149 and rs2251780, was not found to be related to NIIHL susceptibility. Conclusion: The allele G of rs1695 and rs6591256 may be risk factors of NIHL.

[Relationship research among CDH23 gene and the risk of noise-induced hearing loss]

Objective: To explore the relationship among CDH23 gene variation and the risk of noise-induced hearing loss (NIHL) . Methods: The nested case-control study was performed and this study followed a cohort of 6297 noise-exposed workers in a steel factory of Henan province in China from January 1, 2006 to December 31, 2015. In July 2019, subjects whose average hearing threshold were more than 40 dB in high frequency were defined as the case group, and subjects whose average hearing threshold were less than 35 dB in high frequency and less than 25 dB in speech frequency were defined as the control group. A nested case-control study which included 572 subjects was carried out, in which subjects consisted of 286 cases and 286 controls. 18 single nucleotide polymorphisms (SNPs) in CDH23 were selected and genotyped, then we analyzed the association among SNPs in CDH23, haplotypes in CDH23 and NIHL risk. Logistic regression was performed to analyze the main effects of SNPs and the interactions between CNE and SNPs adjusting cumulative noise exposure (CNE) , smoking, drinking, physical exercise and hypertension. Moreover, the association between haplotypes in CDH23 and NIHL risk were also analyzed. We ananlyzed the relationship amongst different SNP groups and NIHL risk using the generalized multifactor dimensionality reduction (GMDR) method. Results: The results suggested that significant associations were observed for rs3802711, rs3752751, rs3752752, rs11592462, rs10762480, rs3747867 for NIHL overall and/or various CNE strata by adjusting CNE, smoking, drinking, physical exercise and blood pressure. For rs3802711, workers exposure to noise carrying the AA/GA genotype of rs3802711 increased risk of NIHL than those carrying GG genotype (OR=3.121; 95%CI:1.054-9.239, P=0.035) in overall; In the stratified analysis of CNE (>97 dB (A) ·year at rs3802711 locus, workers exposure to noise carrying GA genotype (OR=2.056; 95%CI:1.226~3.448, P=0.006) and GA+AA/GA genotype (OR=2.221; 95%CI:1.340~3.681, P=0.002) increased NIHL risk. For rs11592462, workers exposure to noise carrying the GG genotype of rs11592462 increased risk of NIHL than those carrying CC genotype in overall (OR=3.951; 95%CI:1.104-14.137, P=0.04) ; workers exposure to noise carrying the GG genotype of rs11592462 increased risk of NIHL than those carrying CG+CC genotype in overall (OR=4.06; 95%CI:1.145-14.391, P=0.03) . After adjusting CNE, smoking, drinking, physical exercise and blood pressure, the haplotypes of CDH23 rs1227049, rs10999947, rs3752752, rs3752751, rs10762480, rs3802711, rs11592462, rs10466026, rs4747194, rs4747195 were not associated with the risk of NIHL. GMDR analysis showed no association between SNP combination and NIHL risk after adjusting CNE, smoking, drinking, physical exercise and blood pressure. Conclusion: Gene polymorphisms in CDH23 might associate significantly with the risk of NIHL.

[Association between GPX1 gene polymorphisms and noise-induced hearing loss]

Objective: To identify association between genetic polymorphism in the Glutathione peroxidase 1 gene (GPX1) and noise-induced hearing loss (NIHL) . Methods: A nested case control study was conducted based on a cohort of noise-exposed subjects. 392 cases were selected from the steel factory in Henan Province, 392 matched control subjects for each case were designated on the basis of the matched criterion including same gender, age (±5years) and duration of exposure to noise (±2years) . Two single nucleotide polymorphisms (SNPs) of GPX1 were genotyped by SNPscanTM multiplex SNP genotyping kit. Hardy-Weinberg equilibrium (HWE) tests were performed using Pearson's χ(2) for each SNP among control group, effects of genotypes of GPX1 on NIHL were analyzed by logistic regression. Results: All two SNPs were in HWE. After adjustment for covariates including smoking status, rs1987628 polymorphism was statistically significantly associated with the NIHL risk under codominant and Dominant inheritance models; In the subjects carrying rs1987628 GA genotype had a higher NIHL risk than those carrying the GG genotype, the adjusted OR value was 1.803 (95%CI 1.215-2.676, P=0.003) . And meanwhile, rs1987628 GA+AA genotype had a higher NIHL risk than those carrying the GG genotype, the adjusted OR value was 1.762 (95%CI 1.197-2.593, P=0.004) . Conclusion: It was suggested that genetic polymorphism in the GPX1 gene might be the genetic susceptible factor for NIHL.

[Association between GSTP1 gave polymorphisms and susceptibility to noise-induced hearing loss]

Objective: To investigate the association between the single nucleotide polymorphisms (SNPS) at rs1695 and rs6591256 in glutathione S-transferase P1 (GSTP1) gene and susceptibility to noise-induced hearing loss in Chinese Han workers exposed to noise. Methods: A 1: 2 matched nested case-control study was performed, which based on the cohort of 6297 workers exposed to noise in an iron and steel plant in Henan, China, who were followed up from January 1, 2006 to December 31, 2015. According to the criteria of binaural average high-frequency hearing threshold ≥40 dB, a total of 292 workers were enrolled as hearing loss group; after the adjustment for sex, type of work, age (difference≤5 years) , and working years of noise exposure (difference≤2 years) , according to the criteria of binaural average high-frequency hearing threshold <35 dB, and the speech frequency hearing threshold of any ear at any frequency band ≤25 dB, a total of 584 workers were enrolled as control group. The single nucleotide polymorphisms (SNPs) of rs1695 and rs6591256 in GSTP1 were genotyped by high throughput SNP genotyping assay. Hardy-Weinberg equilibrium of control group was checked. The association between the SNPs at the two loci and susceptibility to NIHL was analyzed. Results: The L(Aeq, 8 h) range of workers exposed to noise was 80.2-98.8 dB (A) . The risk of NIHL in individuals with allele G of rs1695 was 1.291 times of those with allele A (95%CI: 1.042-1.598, P<0.05) . The risk of NIHL in individuals with allele G of rs6591256 was 1.390 times of those with allele A (95%CI: 1.119-1.728, P<0.05) . The risk of NIHL in individuals with AG and GG genotypes of rs6591256 was 1.437 times of those with AA genotype (95%CI: 1.057-1.952, P<0.05) . With the increase of noise exposure duration, individuals with AG and GG genotypes of rs6591256 had a higher risk of NIHL than those with AA genotype (HR=1.273, 95%CI: 1.002-1.616, P<0.05) . Conclusion: The allele G of rs1695 and rs6591256 may be risk factors of NIHL.

Involvement of putrescine in osmotic stress-induced ABA signaling in leaves of wheat seedlings

To elucidate one mechanism by which putrescine (Put) functions in plant signaling under osmotic stress, Put and ABA contents, and plasma membrane-NADPH oxidase (PM-NOX) activity were detected in wheat seedling leaves. Under osmotic stress, ABA and Put contents, PM-NOX activity, and PM-NOX-dependent O2.^- production all increased. The inhibitor tungstate (T) of ABA bio-synthesis reduced the increases in ABA and Put contents under osmotic stress. The inhibitor D-arginine (D-Arg) of Put bio-synthesis didn't reduce osmotic-induced increase of ABA, but it inhibited the increases of PM-NOX activity and O2 . ^- production, and the inhibitory effects were reversed by exogenous Put. These findings suggested that ABA might regulate Put biosynthesis, and Put might regulate PM-NOX activity. Treatments with three inhibitors imidazole (I), diphenylene iodonium (DPI) and pyridine (P) of PM-NOX reduced significantly not only O2 . ^- production, but also the stress-induced increase of Put content, which indicated that O2 . ^- production might regulate Put biosynthesis. Treatments with EGTA (Ca²⁺ chelator), La³⁺ and verapamil (V) (Ca²⁺ channel blockers) reduced significantly the stress-induced increase of Put content, which suggested that Ca²⁺ might regulate Put biosynthesis. With these findings, it could be concluded that Put was involved in ABA signaling induced by osmotic stress via regulating PM-NOX activity in wheat seedling leaves.

[Clinicopathological analysis of 12 cases of children synovial sarcoma]

Objective: To investigate histopathological characteristics, and differential diagnoses of childhood synovial sarcoma. Methods: HE staining, immunohistochemical staining and fusion gene detection by FISH were performed in 12 cases of synovial sarcoma in childhood at Beijing Children's Hospital from 2016 to 2018. Results: There were 6 cases of biphasic type, 1 case of monophasic epithelial type, 3 cases of monophasic spindle cell type and 2 cases of poorly differentiated synovial sarcomas. EMA, CKpan, bcl-2, CD99, TLE1 and CD34 immunostain positivities were observed in 10/12, 9/12, 12/12, 10/12, 10/12 and 0/12 cases respectively. Unique INI1 immunohistochemical staining was observed in 9/12 cases. SS18-SSX gene fusion was detected in 8 of 11 cases by FISH. Conclusions: Synovial sarcoma is rare in children. Histological morphology combined with immunohistochemistry and FISH SS18-SSX fusion gene detection are important for the diagnosis and differential diagnosis of synovial sarcoma in children.

[Evaluation of the influenza vaccine effectiveness among children aged 6 to 72 months based on the test-negative case control study design]

Objective: To assess the effectiveness of seasonal influenza vaccine among children aged 6 to 72 months. Methods: The test-negative case control study was conducted based on available surveillance data which was from China Influenza Surveillance Information system (CSIS). From October 2016 to April 2017 and from October 2017 to April 2018,1 161 cases aged 6-72 months with influenza-like illness in Yongkang and Yiwu city, were selected as the study subjects, and the cases with influenza test-positive were selected as the case group (403 cases). Test-negative subjects were selected as control group (758 cases). The etiology and immunization data of the subjects were obtained from CSIS and Immune Information and Management System (IIMS) respectively. Vaccine effectiveness was estimated using multivariate logistic regression model,and the mixed effects of non-randomized control in TNCC study were equalized by using the propensity score (PS) method in the statistical analysis. Results: The age of the subjects was (2.44±1.60) years,and there were 681 boys (58.66%). The age of case group was (2.62±1.58) years, and there were 246 boys (61.04%). The case group was including of 237 cases (58.81%) of influenza A (H3N2), 92 cases (22.83%) of influenza A (H1N1) pmd09, 62 cases (15.38%) of influenza B(Victoria) lineage, 11 cases (2.73%) of influenza B (Yamagata) lineage and one case (0.25%) co-infection of influenza [A(H(3)N(2))+B (Victoria)]. The mean age of the control group was (2.35±1.61) years,and there were 435 boys (57.39%). Overall vaccine effectiveness (VE) against all type influenza for two seasons combined was 58% (95%CI: 31%-74%). An analysis by age groups showed 68% (95%CI:41%-82%) of the VE estimate among children aged 36-72 months while it was 28%(95%CI:-80%-71%)of the VE estimate among children aged 6-35 months. The VE estimate value was 54% (95%CI:16%-75%) against all type influenza and 65% (95%CI:24%-83%) against influenza A (H(3)N(2)) during the 2016-2017 season. During the 2017-2018 season, the VE estimate value was 69% (95%CI:18%-88%) against all type influenza. Conclusion: Influenza vaccine is effective in preventing influenza virus infection during the flu season,especially the effect among children aged 36-72 months is higher compared to that among children aged 6-35 months.

[Association between single nucleotide polymorphismsin human heat shock protein 70 gene and susceptibility to noise-induced hearing loss]

Objective: To investigate the association between the single nucleotide polymorphisms (SNPs) at rs1043618, rs2075800, and rs2763979 in human heat shock protein 70 (HSP70) gene and susceptibility to noise-induced hearing loss (NIHL) . Methods: A case-control study was performed, and 5 934 workers exposed to noise in an iron and steel plant in Henan, China, who underwent physical examination from 2006 to 2015, were enrolled as study subjects. According to the criteria of binaural average high - frequency (3000, 4000, and 6000 Hz) hearing threshold≥40 dB (HL) and monauralaverage speech-frequency (500, 1000, 2000 Hz) hearing threshold≥26 dB (HL) on the basis of binauralhigh frequency loss measured by pure tone audiometry, as well as the exclusion of NIHL, a total of 286 workers were enrolled as hearing loss group; after the adjustment for sex, type of work, age (difference≤5 years) , and working years of noise exposure (difference ≤2 years) , 286 workers were enrolled as control group. A 2 ml blood genomic DNA extraction kit was used to perform DNA extraction for the peripheral blood samples, and a multiple SNP typing kit was used to determine the genotypes at the three loci in 572 samples. The association between the SNPs at the three loci and susceptibility to NIHL was analyzed. Results: In all workers, the equivalent sound level (L(Aeq)) of noise was 75.0~96.8 dB (A) . The hearing loss group had a significantly higher binauralhigh - frequencyhearing threshold than the control group (t=56.908, P<0.05) . With CC+TC genotype as control, TT genotype at rs2763979 in HSP70 gene was associated with the susceptibility to NIHL (OR=1.731, 95%CI 1.021-2.935) . In the group with cumulative noise exposure of 96 dB (A) ·year, TT genotype at rs2763979was associated with the susceptibility to NIHL (OR=5.694, 95%CI 1.256-25.817) . The rs1043618 and rs2075800 loci of HSP70 were not associated with the susceptibility to NIHL (both P>0.05) . After the adjustment for confounding factors including smoking and drinking, haplotype CCT was associated with the susceptibility to NIHL (OR=1.425, 95%CI 1.035-1.961) . Conclusion: TT genotype at rs2763979 of HSP70 gene and haplotype CCT are risk factors for NIHL.

[A cohort study on occupational noise induced hearing loss in workers at an iron and steel plant]

Objective: To analyze the incidence rate of occupational noise-induced hearing loss in noise-exposed workers in an iron and steel plant from 2006 to 2015. Methods: Using a cohort study method, workers exposed to occupational noise from Jan 1, 2006 to Dec 12, 2015 were followed up and the pure tone hearing test was conducted. In total, 6 297 subjects completed two or more physical checks and the pure tone hearing test and were included in the analysis. The noise exposure level at the workplace and the equivalent continuous A-weighted sound pressure level for workers was monitored and the cumulative noise exposure dose was evaluated. The subjects were divided into low, middle and high exposure groups according to the noise exposure level, and the equivalent continuous A-weighted sound pressure level for 8 hours for each group was 80.6-85.0, 85.1-90.0 and 90.1-103.4 dB (A), respectively. While the RR and 95% CI were derived from unconditional logistic regression models. In logistic regression analysis, confounding factors such as age, gender, smoking habit, drinking habit, high temperature exposure and chemical hazards exposure level were controlled. Results: During the follow-up period, 392 cases of occupational noise-induced hearing loss were diagnosed among the 6 297 subjects, with an incidence rate of 6.23%; 318 cases of high-frequency hearing loss were diagnosed, with an incidence rate of 5.05%; and 74 cases of occupational noise-induced deafness were diagnosed, with an incidence rate of 1.18% . The incidence rates of hearing loss among the high, medium and low exposure groups were 9.22% (158/1 737), 6.49% (204/3 142) and 2.08% (30/1 442), respectively; the rates of high-frequency hearing loss were 7.41% (127/1 737), 5.25% (165/3 142) and 1.80% (26/1 442), respectively; and the rates of occupational noise-induced deafness were 1.81% (31/1 737), 1.24% (39/3 142) and 0.28% (4/1 442), respectively. For the groups corresponding to cumulative noise exposure doses of ≤84.99, 85.00- 87.99, 88.00- 90.99, 91.00- 93.99, 94.00- 96.99, 97.00- 100.99, 101.00- 102.99 and ≥103.00 dB (A) · year, the incidence rates of hearing loss were 0 (0/185), 1.22% (2/164), 2.52% (17/674), 3.83% (35/913), 5.80% (106/1 827), 6.02% (67/1 113), 9.20% (95/1 003) and 18.04% (70/388), respectively. Compared with the low exposure group, the RR of hearing loss, high-frequency hearing loss and occupational noise-induced deafness for the high exposure group were 4.78 (95% CI: 3.22- 7.11), 4.36 (95% CI: 2.84- 6.69) and 6.63 (95% CI: 2.33- 18.82), respectively; and for the medium exposure group were 3.27 (95% CI: 2.22-4.82), 3.02 (95% CI: 1.99-4.59) and 4.52 (95% CI: 1.61-12.67), respectively. Conclusion: The incidence rate of hearing loss for workers exposed to noise in an iron and steel plant was related to the cumulative noise exposure dose, gender, age, educational level, smoking habits, drinking habits and exposure to high temperature.

[Investigation into the relationship between mitochondrial 12 S rRNA gene, tRNA gene and cytochrome oxidase Ⅱ gene variations and the risk of noise-induced hearing loss]

Objective: To explore the relationship between mitochondrial 12 S rRNA gene variation, tRNA gene variation and cytochrome oxidase Ⅱ gene point mutations and the risk of noise-induced hearing loss (NIHL). Methods: A nested case-control study was performed that followed a cohort of 7 445 noise-exposed workers in a steel factory in Henan province, China, from January 1, 2006 to December 31, 2015. Subjects whose average hearing threshold was more than 40 dB(A) in high frequency were defined as the case group, and subjects whose average hearing threshold was less than 35 dB(A) in high frequency and less than 25 dB (A) in speech frequency were defined as the control group. Subjects was recruited into the case group (n=286) and the control group (n=286) according to gender, age, job category and time of exposure to noise, and a 1∶1 case-control study was carried out. We genotyped eight single nucleotide polymorphisms in the mitochondrial 12 S rRNA gene, the mitochondrial tRNA gene and the mitochondrial cytochrome oxidase Ⅱ gene using SNPscan high-throughput genotyping technology from the recruited subjects. The relationship between polymorphic sites and NIHL, adjusted for covariates, was analyzed using conditional logistic regression analysis, as were the subgroup data. Results: The average age of the recruited subjects was (40.3±8.1) years and the length of service exposure to noise was (18.6±8.9) years. The range of noise exposed levels and cumulative noise exposure (CNE) was 80.1- 93.4 dB (A) and 86.8- 107.9 dB (A) · year, respectively. For workers exposed to noise at a CNE level<98 dB (A) · year, smokers showed an increased risk of NIHL of 1.88 (1.16-3.05) compared with non-smokers; for workers exposed to noise at a CNE level ≥98 dB(A) · year, smokers showed an increased risk of NIHL of 2.53 (1.49- 4.30) compared with non-smokers. For workers exposed to noise at a CNE level<98 dB (A) · year, the results of univariate analysis and multifactor analysis, adjusted by smoking and CNE, suggested that the risk of NIHL in workers exposed to noise carrying the GG genotype (G827A) was lower than that of NIHL workers exposed to noise carrying the AA genotype (G827A) [OR (95% CI) were 0.18 (0.04- 0.82) and 0.19 (0.04- 0.88), respectively]. Conclusion: Smoking increased the risk of NIHL in the present study. For workers subjected to a CNE<98 dB(A)·year, the mitochondrial genetic variant G827A was found to be significantly associated with the risk of NIHL.

Complete mitochondrial genome of the Liuyang black goat and its phylogenetic relationship with other Caprinae

In this study, the complete mitochondrial genome sequence of the Liuyang black goat was investigated, and phylogenetic relationships between the Liuyang black goat and other species of Caprinae were analyzed. The total length of the mitochondrial genome was 16,715 bp, which consisted of 33.50% A, 27.27% T, 25.98% C, and 13.25% G. The mitochondrial genome contained a major non-coding control region (D-loop region), two ribosomal RNA genes, 13 protein-coding genes, and 22 transfer RNA genes. Neighbor-joining and maximum-parsimony trees of Caprinae constructed using 13 mitochondrial protein-coding genes showed that the Liuyang black goat is phylogenetically closest to Hemitragus jemlahicus (the Himalayan tahr) and Blue sheep to form clade A. Tibetan antelopes clustered separately in clade B and so did sheep in clade C.

[Association between grainyhead-like 2 gene polymorphisms and noise-induced hearing loss]

OBJECTIVE

To investigate association between genetic polymorphism in the grainyhead-like 2 gene (GRHL2) and noise-induced hearing loss (NIHL) in the Chinese population.

METHODS

A matched case-control association study was employed, In which, 3 790 workers exposed to continuous and steady-state occupational noise in a steel factory participated. The questionnaires were adopted to collect individual features and audiometry tests performed. In the sstudy, 286 subjects were diagnosed as cases, Which were each designated on the basis of the matched criterion, and 286 paired samples were selected finally. Noise intensity was measured according to the standards given in 'Measurement of Noise in the Workplace'(Occupational Health Standard of the People's Republic of China, GBZ/T189.8-2007). Cumulative noise exposure (CNE) was calculated, according to monitoring data on A-weighed sound pressure level and employment time. Genomic DNA was obtained from peripheral blood samples using 2 mL DNA extraction Kit following the manufacturer's protocol. Five single nucleotide polymorphisms (SNPs) of GRHL2 were genotyped by multiplex SNP genotyping kit. The continuous variables and categorical variables were analyzed by t-test and chi-square test respectively. Multivariate Logistic regression was used to test the association between genetic frequency and disease status, with adjustments for the possible confounding variables. The haplotypes were established and their frequencies in the two groups were assessed by haploview and phase softwares.

RESULTS

All the five SNPs (rs3735713, rs3824090, rs3735714, rs3735715 and rs611419) were in Hardy-Weinberg equilibrium (HWE) (P>0.05). The subjects carrying rs3735715 GG genotype had a higher NIHL risk than those carrying the GA genotype under the co-dominant model (OR=0.644, 95% CI: 0.442-0.939, P=0.022) after adjustment for height, blood pressure, drinking status and smoking status. After being stratified by CNE, in the CNE ≥ 98 dB (A) group, rs3735715 polymorphism was associated with the NIHL under the co-dominant model (OR=0.509, 95% CI: 0.281-0.923, P=0.026) after adjustment for height, blood pressure, drinking status and smoking status as well. However, no statistical significant difference was found in variant genotypes of the other SNPs between the case and control subjects. Four-locus (rs3735713, rs3824090, rs3735714 and rs3735715) haplotypes were constructed, and no risk or protective haplotypes was identified.

CONCLUSION

It is suggested that GRHL2 polymorphisms may be associated with development of NIHL.

[Factors influencing electrocardiogram results in workers exposed to noise in steel-making and steel-rolling workshops of an iron and steel plant]

OBJECTIVE

To investigate the factors influencing the electrocardiogram results in the workers exposed to noise in steel-making and steel rolling workshops of an iron and steel plant.

METHODS

From September to December, 2013, cluster sampling was used to select 3 150 workers exposed to noise in the steel-making and steel-rolling workshops of an iron and steel plant, and a questionnaire survey and physical examinations were performed. The number of valid workers was 2 915, consisting of 1 606 workers in the steel-rolling workshop and 1 309 in the steel-making workshop. The electrocardiogram results of the workers in steel-making and steel-rolling workshops were analyzed.

RESULTS

The overall abnormal rate of electrocardiogram was 26.35%, and the workers in the steel-making workshop had a significantly higher abnormal rate of electrocardiogram than those in the steel-rolling workshop(32.24% vs 21.54%, P<0.05). Male workers had a significantly higher abnormal rate of electrocardiogram than female workers(27.59% vs 18.61%, P<0.05). The workers with a drinking habit had a significantly higher abnormal rate of electrocardiogram than those who did not drink(28.17% vs 23.75%, P<0.05). The workers exposed to high temperature had a significantly higher abnormal rate of electrocardiogram than those who were not exposed to high temperature(29.43% vs 20.14%, P<0.05). The abnormal rates of electrocardiogram in the workers with cumulative noise exposure levels of <90, 90~94, 95~99, 100~104, and 105~113 dB(A)·year were 21.21%, 21.76%, 26.50%, 27.27%, and 32.16%, respectively, with significant differences between any two groups(P<0.05). The multivariate logistic regression analysis showed that a cumulative noise exposure of 105-113 dB(A)·year(OR=1.36, 95% CI: 1.03~1.80), a drinking habit(OR=1.20, 95% CI: 1.01~1.43), and high temperature(OR=1.60, 95% CI: 1.32~1.92) were the risk factors for abnormal electrocardiogram results.

CONCLUSION

High cumulative noise exposure, alcohol consumption, and high temperature may affect the abnormal rate of electrocardiogram in the workers exposed to noise in steel-making and steel-rolling workshops.

Nerve conduction block in diabetic rats using high-intensity focused ultrasound for analgesic applications

BACKGROUND

Nerve conduction block using high-intensity focused ultrasound (HIFU) has been conducted with nerves of mixed fibres in normal animal models. This study tested the feasibility and safety of HIFU for sensory nerve conduction block in diabetic neuropathic nerves to determine its potential for pain relief.

METHODS

Diabetes was induced in Sprague-Dawley rats using streptozotocin, and HIFU at 2.68 MHz was used for the block. This study consisted of two sections, in vitro and in vivo. For the in vitro experiments, the entire contiguous sciatic-sural nerves were obtained. Compound action potentials and sensory action potentials were recorded in the sciatic and sural nerves, respectively. For the in vivo experiments, compound muscle action potentials (CMAPs) were recorded from the gastrocnemius muscles. All data were expressed as median (range).

RESULTS

The in vitro results showed that HIFU temporarily inhibited sensory action potentials of the control and diabetic rat nerves to 33.9 (8.2) and 14.0 (10.7)% of the baseline values, respectively, whereas the compound action potentials were suppressed to 53.6 (8.4) and 76.2 (7.5)% of baseline, respectively. The in vivo results showed that HIFU acutely blocked CMAPs to 32.9 (12.6) and 19.9 (10.9)% of baseline in control and diabetic rat nerves, respectively. Measurements of CMAPs and histological exanmination were used for indirect assessment of the safety of the HIFU technique.

CONCLUSIONS

High-intensity focused ultrasound safely and reversibly suppressed nerve conduction in diabetic rat nerves when the stimulation parameters were appropriate. The results suggest that HIFU may have potential to block sensory nerves reversibly and provide peripheral pain relief.

QSAR modeling of toxicity of acyclic quaternary ammonium compounds on Scenedesmus Quadricauda using 2D and 3D descriptors

Optimized calculation of typical acyclic quaternary ammonium compounds (QACs) was performed at B3LYP/6-311G** level using density functional theory (DFT) method. A two- dimensional quantitative structure-activity relationship (2D-QSAR) model was established with the obtained structure parameters as theoretical descriptors. And then three-dimensional quantitative structure-activity relationship (3D-QSAR) models were built using comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) methods respectively. The 2D and 3D QSAR models exhibit optimum stability and predictive ability, revealing that steric and electronic effects influence the toxicity of acyclic QACs to Scenedesmus Quadricauda mostly.

Mechanistic correlations between two itch biomarkers, cytokine interleukin-31 and neuropeptide β-endorphin, via STAT3/calcium axis in atopic dermatitis

BACKGROUND

Itch is the cardinal symptom of atopic dermatitis (AD). β-Endorphin, a neuropeptide, is increased in both AD skin and sera. Interleukin (IL)-31, an itch-relevant cytokine, activates IL-31 receptors in keratinocytes. However, how IL-31 and β-endorphin interact in AD skin remains elusive.

OBJECTIVES

To investigate the mechanistic interaction of IL-31 and β-endorphin in AD.

METHODS

This was a prospective cross-sectional study. We recruited adult patients with AD and controls according to Hanifin's AD criteria. Serum levels of IL-31 and β-endorphin were measured by enzyme-linked immunosorbent assay. Expressions of IL-31 receptor A (IL-31RA) and β-endorphin in the skin were assessed by immunohistochemistry. Their expression in the skin and blood was compared and correlated in patients with AD and in controls. We also treated primary keratinocytes with IL-31 and measured calcium influx, β-endorphin production and signalling pathways to define their mechanistic interactions.

RESULTS

β-Endorphin was increased in the supernatant from IL-31-treated keratinocytes. IL-31 receptor activation resulted in calcium influx and STAT3 activation; pretreatment with STAT3 inhibitor stopped the increase of β-endorphin. Notably, either replacement of extracellular calcium or treatment with 2-aminoethoxydiphenyl borate, an inhibitor for the store-operated channel, blocked STAT3 activation. We found higher levels of blood β-endorphin and IL-31, which were significantly correlated, in patients with AD. Moreover, IL-31RA and β-endorphin were increased and colocalized both in AD human skin and TPA-painted mouse skin.

CONCLUSIONS

IL-31 receptor activation in keratinocytes induces calcium influx and STAT3-dependent production of β-endorphin. These results might contribute to an understanding of the regulatory mechanisms underlying peripheral itch.

High-glucose environment reduces human β-defensin-2 expression in human keratinocytes: implications for poor diabetic wound healing

BACKGROUND

Wound healing is a dynamic and complicated process in which inflammation, re-epithelialization and angiogenesis play important roles. Intriguingly, all three processes have been found to be defective during diabetic wound healing conditions. One common denominator associated with regulation of these events is human β-defensin-2 (hBD2). It has been shown that skin wounding induces cutaneous hBD2 expression, and diabetic wounds have been associated with inadequate hBD expression.

OBJECTIVES

The current study was launched to explore the effects of a high-glucose environment on cultured human keratinocytes.

METHODS

Human keratinocytes were exposed to indicated culture conditions. The mRNA and protein levels of hBD2 were determined, and activation of relevant pathways was evaluated. The small interference RNA approach was used to validate the functional role of the proposed pathway on hBD2 expression.

RESULTS

We showed that high-glucose cultivated keratinocytes expressed reduced levels of hBD2 and phosphorylated signal transducer and activator of transcription (pSTAT)-1 constitutively. In addition, pSTAT-1 signalling is critically involved in hBD2 expression. Formation of advanced glycation endproducts, a direct consequence of a high-glucose environment, involves constitutive downregulation of pSTAT-1 and hBD2. The addition of interleukin-1β, an important cytokine during the cutaneous wound healing process, enabled the upregulation of hBD2 expression of both normal- and high-glucose cultivated keratinocytes, but the absolute levels of hBD2 were still significantly lower in the high-glucose-treated group.

CONCLUSIONS

As hBD2 plays multifaceted roles during the wound healing process, the inadequate expression of hBD2 during diabetic conditions contributes to impaired wound healing.

Noninvasive cutaneous blood flow as a response predictor for visible light therapy on segmental vitiligo: a prospective pilot study

BACKGROUND

Visible light is a treatment option for segmental vitiligo (SV), and visible light-induced repigmentation is associated with normalization of sympathetic dysfunction. Currently, it is difficult to predict individual patients' response to visible light therapy.

OBJECTIVES

To test whether cutaneous blood flow can serve as a response predictor for visible light on treating SV.

METHODS

Fourteen patients with SV were recruited in this prospective pilot study. Laser Doppler flowmetry was used to evaluate the cutaneous blood flow over SV lesions and contralateral normal skin. The pretreatment blood flow evaluation consisted of two stages: stage 1, following cold stress without prior visible light irradiation, and stage 2, following cold stress with prior visible light irradiation. Subsequently, the patients received regular visible light treatment for 3months, and a comparison of the pretreatment blood flow patterns between the visible light responding and nonresponding groups was carried out at the end of the study period.

RESULTS

The SV lesions showed different blood flow profiles as compared with the contralateral normal skin. At the end of the 3-month study period, seven (50%) patients showed clinical repigmentation of >25%. The visible light responding group showed a more consistent occurrence of increased blood flow after stage 2 of the pretreatment evaluation while the nonresponding counterpart showed no significant changes.

CONCLUSIONS

Normalization of sympathetic dysfunction may account for the efficacy of visible light in treating SV. Evaluation of cutaneous blood flow with and without prior visible light irradiation on cold-stressed SV lesions may serve as a treatment response predictor.

FK506 (tacrolimus) and endothelin combined treatment induces mobility of melanoblasts: new insights into follicular vitiligo repigmentation induced by topical tacrolimus on sun-exposed skin

BACKGROUND

Topical tacrolimus (FK506) has been considered as a treatment option for treating vitiligo, a dermatosis characterized by disappearance of melanocytes (MCs). Previous reports have shown that a significant portion of treated patients demonstrated follicular repigmentation, indicating that the activation of MC precursor cells residing in the outer root sheath of hair follicles played an important role during the tacrolimus-induced repigmentation process.

OBJECTIVES

To investigate the mechanisms involved in follicular pigmentation induced by topical tacrolimus.

METHODS

As stem cells of MC lineage are identified in the lower portion of mouse hair follicles throughout the hair cycle, immature mouse melanoblasts (MBs) derived from neural crest cells (NCCmelb4) were used for this study. Relevant maturation parameters were evaluated.

RESULTS

Our results revealed that FK506 stimulated the expressions of protein kinase A, protein kinase C and phosphorylated p38 mitogen-activated protein kinase. However, cell motility, a parameter associated with MB differentiation, was not enhanced by FK506 treatment. Endothelin (ET)-3, a prodifferentiation factor of MBs, also failed to promote NCCmelb4 cell locomotion. Combining ET-3 and FK506, however, stimulated cell mobility. ET B receptor, which was not present in NCCmelb4 cells, was induced after FK506 treatment.

CONCLUSIONS

In summary, we have shown that FK506 is an efficient differentiation-stimulating agent, especially for cells of neural origin. The clinical efficacy of topical tacrolimus on vitiligo may be enhanced by combination with ET-3.

Onychomycosis caused by Fusarium solani in a woman with diabetes

A case of untreated fusarial onychomycosis leading to serious consequences is reported. Fusarium solani is a widespread fungus and an occasional human pathogen. It usually invades rapidly in immunocompromised hosts, and often results in a poor outcome despite treatment. We report a woman with diabetes mellitus who had untreated fusarial infection of the nails, which developed into subcutaneous fusariosis, superinfected by bacteria, and then evolved into osteomyelitis that subsequently resulted in septic shock. Early management of mycotic nails in immunocompromised hosts is crucial to prevent life-threatening disease.

Topical tacrolimus has a limited direct effect on ultraviolet B-irradiated keratinocytes: implications for its photocarcinogenic potential

BACKGROUND

Topical tacrolimus has shown remarkable clinical efficacy in treating many dermatoses. Combining ultraviolet (UV) B and tacrolimus is an intriguing therapeutic regimen, especially for treatment of vitiligo, for which combination therapy may show greater clinical efficacy than topical tacrolimus alone. The photocarcinogenic potential of such a regimen is unclear, and conflicting results have been reported by different investigators.

AIM

To clarify this important clinical issue, we investigated the effects of tacrolimus on UVB-irradiated cultured keratinocytes in terms of apoptosis, differentiation, cell-cycle regulation and DNA damage.

METHODS

Cultured keratinocytes were treated with tacrolimus before and after UVB irradiation and the various cellular physiological changes were evaluated using trypan blue exclusion, terminal dUTP nick-end labelling, flow cytometry and Western blotting analyses.

RESULTS

Our results showed that treatment of tacrolimus before or after UVB irradiation had no significant effects on cultured keratinocytes in terms of cell apoptosis, transglutaminase-1, involucrin expression, cell-cycle progression and phospho-H(2)AX compared with UVB irradiation alone.

CONCLUSION

The direct effect of tacrolimus on UVB-irradiated keratinocytes is small, suggesting that clinical regimens combining UVB and tacrolimus also have a limited direct effect on healthy skin compared with UVB irradiation alone.

Hyperglycaemic conditions hamper keratinocyte locomotion via sequential inhibition of distinct pathways: new insights on poor wound closure in patients with diabetes

BACKGROUND

Diabetes mellitus (DM) is characterized by impaired insulin signalling, elevated plasma glucose, and predisposition towards complications involving several organs. A major complication of DM is impairment of wound healing. In the re-epithelialization process during wound healing, migration of keratinocytes is a crucial step. Our previous report demonstrated that keratinocytes cultured in hyperglycaemic media showed decreased cell mobility.

OBJECTIVES

The current study aimed to explore the effects of high glucose on keratinocyte migration after different treatment durations.

METHODS

Keratinocytes were cultivated for indicated time periods under various concentrations of glucose. Relevant assays including Transwell migration and in vitro wound scratch assays, flow cytometric analysis, matrix metalloproteinase-1 (MMP-1) activity assay, determination of mRNA expression and Western blotting were performed.

RESULTS

We demonstrated that (i) keratinocyte motility progressively and significantly decreased; (ii) the keratinocyte activation marker K16 was significantly suppressed; (iii) expression of alpha2beta1 integrin and MMP-1, both crucial for keratinocyte locomotion on collagen type I, was significantly downregulated; and (iv) expression of the phosphorylated signal transducer and activator of transcription-1 significantly decreased after hyperglycaemic treatment. More specifically, different pathways become involved after prolonged duration of high glucose cultivation to reduce keratinocyte locomotion further.

CONCLUSIONS

We have demonstrated that high glucose treatment results in progressive suppression of keratinocyte locomotion and elucidated the molecular mechanisms involved. These results provide a reasonable explanation for the poor wound healing seen in patients with DM.

Cutaneous metastases from different internal malignancies: a clinical and prognostic appraisal

BACKGROUND

Cutaneous metastases are perceived as a sign of advanced disease and are regarded as a grave prognostic indicator. In addition, few reports have focused on the cutaneous metastasis profiles of Asian patients.

OBJECTIVES

We seek to analyse the clinical and prognostic characteristics of cutaneous tumour metastases in a Taiwanese medical centre.

METHODS

Clinical records from Kaohsiung Medical University Hospital over the last 20 years (1986-2006) were reviewed, and cases of biopsy-proven cutaneous metastases from internal malignancies identified. Survival rates were evaluated using the Kaplan-Meier method and compared by the log-rank test. The Cox proportional hazards model was used for univariate analysis to determine the risk of mortality among different groups.

RESULTS

A total of 141 cases of cutaneous metastases were identified. The clinical profiles were similar to those from western countries, although the frequencies of primary tumours were different. The duration of survival was usually short following diagnosis of cutaneous metastases, but prognosis is significantly better in breast cancer patients with metastases. Moreover, the survival was even longer for breast cancer patients when the metastasis was confined to the skin.

CONCLUSIONS

The risk of skin metastases depends largely on the characteristics of tumour cells, which is similar among different ethnic groups. In terms of prognosis, a subset of breast cancer patients has superior prognosis, even among breast cancer patients with stage IV disease. Physicians should consider this finding in clinical situations to avoid possible misinformation about the prognosis of the disease.

Expression of interferon-gamma in human adrenal gland and kidney tumours

It is known that interferon-γ (IFN-γ) is produced by activated T and NK lymphoid cells, mononuclear cells, and macrophage and dendritic cells. Our previous studies have shown that IFN-γ-like immunoreactivity also appears in human adrenal cortical tumour and phaeochromocytoma. To investigate whether human tumour cells can produce IFN-γ, we examined 429 biopsy specimens of 30 kinds of tumour and tumour-surrounding tissues in adrenal glands and in kidneys by using immunohistochemistry and in situ hybridisation. IFN-γ immunoactivity was shown in 34.3% of the adrenal cortical adenomas, 50% of the adrenal cortical carcinomas, 26.7% of the phaeochromocytomas, 26.7% of the clear cell renal cell carcinomas (RCCs), 22% of the adrenal cortexes and 40% of medullas adjacent to tumours. The positive samples and expression areas were well overlapped between the IFN-γ mRNA and the immunohistochemistry staining. Western blot analysis has further confirmed the immunohistochemistry results by showing a distinct IFN-γ band corresponding to 17.4 kDa in tissue extracts from adrenal cortical adenoma, phaeochromocytoma and clear cell RCCs. These results indicate that IFN-γ is produced by some types of tumour cells, suggesting it may play a dual role in the development of these tumours.

Effects of psoralen plus ultraviolet A irradiation on cultured epidermal cells in vitro and patients with vitiligo in vivo

BACKGROUND

Both psoralen plus ultraviolet (UV) A (PUVA) and narrowband UVB (NB-UVB) irradiation are effective treatments for vitiligo vulgaris. However, the mechanisms of PUVA and NB-UVB in repigmentation are not thoroughly clarified. Our previous results showed that NB-UVB irradiation directly promotes melanocyte (MC) migration and stimulates MC proliferation via keratinocytes (KCs).

OBJECTIVES

In the present study, we used NB-UVB as a reference for comparison to investigate the immediate effects of PUVA on MC proliferation and migration.

METHODS

Cultured MCs and KCs were treated with PUVA or irradiated with NB-UVB. The direct impact of PUVA treatment on MCs was assessed in terms of its effect on MC proliferation and migration. The indirect effect of PUVA treatment and NB-UVB irradiation on MC proliferation via KCs was also investigated. The activities of matrix metalloproteinase (MMP)-2 and MMP-9, known for their influence on cell migration, were evaluated in the PUVA-treated MC and KC supernatants. The concentrations of MC mitogens/growth factors in the PUVA-treated KC supernatants were also determined. In addition, the serum levels of MC mitogens/growth factors in healthy controls, in patients with active vitiligo and in patients with repigmenting vitiligo after PUVA treatment were determined to elucidate the mechanisms of how PUVA induces vitiligo repigmentation in vivo.

RESULTS

Our results demonstrated that PUVA treatment did not significantly stimulate the release of MC mitogens/growth factors from KCs. The migration of MCs was also not enhanced after PUVA treatment. The expression of MMP-2 activity in supernatants derived from PUVA-treated MCs was significantly increased as compared with the control group. However, neither MMP-2 nor MMP-9 activity in KC supernatants was stimulated by PUVA treatment. In contrast to NB-UVB, immediate effects of PUVA on MC proliferation and migration were not observed in this study. Sera from patients with repigmenting vitiligo after PUVA treatment contained higher levels of basic fibroblast growth factor, stem cell factor and hepatocyte growth factor as compared with healthy controls and patients with active vitiligo.

CONCLUSIONS

Our results indicate that in addition to immune suppression, PUVA treatment creates a favourable milieu for promoting the growth of MCs in patients with vitiligo instead of directly stimulating the regrowth of MCs. Based on our results, we propose that in the active stage of vitiligo, PUVA treatment is the therapy of choice to slow down the destruction of MCs and to create a favourable environment for MCs to survive. In the stable stage of vitiligo, NB-UVB irradiation should be used to stimulate the proliferation and migration of MCs directly.