[Ewing's sarcoma of central nervous system: a clinicopathological analysis of six cases].

Objective: To investigate the clinicopathological characteristics, pathological diagnosis of Ewing's sarcoma of the central nervous system. Methods: Six cases of Ewing's sarcoma of the central nervous system diagnosed at the First Affiliated Hospital of Nanjing Medical University, Nanjing, China from 2015 to 2022 were collected. The clinical manifestations, histological morphology, immunophenotype and molecular genetics of these cases were analyzed. The related literature was reviewed. Results: There were four males and two females, with a male to female ratio of 2∶1. The onset age was 17-40 years, with a median age of 23 years. All 6 tumors were located in the spinal cord (2 cases of cervical vertebra, 1 case of thoracic vertebra, 2 cases of lumbar vertebra, and 1 case of sacral vertebra). The patients' clinical manifestations were mostly lumbago, weakness and numbness of lower limbs/limbs. In 1 case, the tumor recurred and metastasized to the suprasellar region and the third ventricle. Microscopically, the tumor showed diffuse infiltrative growth. In some cases, the tumor was closely related to the spinal meninges. The tumor cells were arranged in sheet, lobular, thin-rope, and nest-like patterns. Homer-Wright rosette was visible. The tumor cells were small to medium in size, and most of them had scant cytoplasm. A few cells had clear cytoplasm. Some areas were rhabdoid. The tumor cell nuclei showed focal mild pleomorphism. The chromatin was uniform and delicate while the nucleoli were not obvious. Mitosis was commonly seen. The tumor was separated by fibrous connective tissue and may be accompanied by mucinous degeneration. Immunohistochemistry showed that all tumors were positive for CD99, NKX2.2, Fli1, ERG. ATRX, H3K27me3, INI1 and BRG1 were all retained. Immunohistochemical stains for EMA, GFAP and Olig2 were negative. The Ki-67 proliferation index was 30%-70%. EWSR1 break-apart FISH test was positive. Conclusions: Ewing's sarcoma is rare in the central nervous system and needs to be distinguished from a variety of neoplasms with primitive undifferentiated small cell morphology. Immunohistochemistry and molecular genetics may be required for a proper diagnosis.

[Diffuse midline glioma with H3K27 alteration in adults: a clinicopathological analysis].

Objective: To investigate the clinicopathological characteristics, pathological diagnosis and prognosis of diffuse midline glioma (DMG) with H3K27 alteration in adults. Methods: Twenty cases of H3K27-altered adult DMG diagnosed in the First Affiliated Hospital of Nanjing Medical University were enrolled from 2017 to 2022. All cases were evaluated by clinical and imaging presentations, HE, immunohistochemical staining and molecular genetics; and the relevant literature was reviewed. Results: The ratio of male to female was 1∶1, and the median age was 53 years (range from 25 to 74 years); the tumors were located in the brainstem (3/20, 15%) and non-brainstem (17/20, 85%; three in thoracolumbar spinal cord and one in pineal region). The clinical manifestations were non-specific, mostly dizziness, headache, blurred vision, memory loss, low back pain, limb sensation and/or movement disorders, etc. Microscopically, the tumors showed infiltrative growth, with WHO grade 2 (3 cases), grade 3 (12 cases), and grade 4 (5 cases). The tumors showed astrocytoma-like and oligdendroglioma-like, pilocytic astrocytoma-like and epithelioid-like patterns. Immunohistochemically, the tumor cells were positive for GFAP, Olig2 and H3K27M, and H3K27me3 expression was variably lost. ATRX expression was lost in four cases, p53 was strongly positive in 11 cases. Ki-67 index was about 5%-70%. Molecular genetics showed p. k27m mutation in exon 1 of H3F3A gene in 20 cases; BRAF mutation in two cases: V600E and L597Q mutation in one case each. Follow up intervals ranged from 1 to 58 months, and the survival time for brainstem (6.0 months) and non-brainstem (30.4 months) tumors was significantly different (P<0.05). Conclusions: DMG with H3K27 alteration is uncommonly found in adults, mostly occurs in non-brainstem, and can present in adults of all ages. Owing to the wide histomorphologic features, mainly astrocytic differentiation, routine detection of H3K27me3 in midline glioma is recommended. Molecular testing should be performed on any suspected cases to avoid missed diagnosis. Concomitant BRAF L597Q mutation and PPM1D mutation are novel findings. The overall prognosis of this tumor is poor, with tumors located in the brainstem showing worse outcome.

[Annual update of pulmonary infectious diseases in 2022].

In 2022, coronavirus disease 2019 (COVID-19) remains rampant across the world. Several remarkable studies concerning pulmonary infectious diseases have been published during this pandemic. This review summarized the representative academic and translational medical progress over the past year (from October 1, 2021, to September 30, 2022), including COVID-19, community/hospital-acquired pneumonia, tuberculosis, and other respiratory viral infections.

[Research and development of an intelligent platform for respiratory therapy].

In recent years, the incidence of respiratory diseases has increased year on year. This has become a major global public health issue. To effectively treat respiratory diseases and improve the quality of life and prognosis of patients, the intelligent platform of respiratory therapy was established. Through real-time monitoring patients' important physiological indicators and integrating medical information, visual management, and intelligent decision making can be realized to provide personalized respiratory treatment and rehabilitation programs for critically ill patients. The platform can also provide reliable data support for medical research and further promote the development of the field of respiratory disease treatment. In the future, the platform will continue to improve the level and efficiency of clinical treatment, and truly solve practical problems for patients.

[Expression and regulatory role of ultraconserved long non-coding RNA uc.77 in lung cancer].

Objective: To investigate the effect and molecular mechanism of ultra-conservative long non-coding RNA uc.77 in lung cancer. Methods: Lung cancer tissues and adjacent normal tissues were obtained from 61 patients with lung cancer who were diagnosed with lung cancer and underwent surgery from 2014 to 2016 in the General Hospital of the Southern Theater Command of the People's Liberation Army. Real-time fluorescence quantitative polymerase chain reaction (qRT-PCR) was used to detect the uc.77 relative expressions in normal human bronchial epithelial cells 16HBE, lung cancer cell lines, and 61 pair lung cancer tissues. Uc.77 siRNA was transfected into lung cancer cells to interfere with the expression of uc.77, qRT-PCR was used to verify the interference effect, CCK8 method and clone formation experiment were used to detect cell proliferation ability, flow cytometry was used to detect apoptosis and cell cycle changes. H1299 cells transfected with uc.77 siRNA were injected into the subcutaneous right side of BALB/c nude mice to construct a tumor-bearing model for exploring the role of uc.77 on tumor growth. Western blot and qRT-PCR methods were used to detect the protein and mRNA expressions of p21. Results: The relative expression levels of uc.77 in lung cancer cell lines 95D, H1299, A549, H460, H446 and 16HBE-T were significantly higher than that of 16HBE cells (P<0.05). The uc.77 RNA expression levels of lung cancer tissues was significantly higher than that of the adjacent normal tissues (P<0.001). In addition, increased lncRNA uc.77 expression was significantly associated with big tumor size, lymph node metastasis and advanced TNM stage (P<0.05). After transfection with uc.77 siRNA, the expressions of uc.77 in H1299, 95-D and 16HBE-T cells were reduced (P<0.05), and the cell proliferation capacities were reduced at 48 hours and 72 hours (P<0.05). After transfection with uc.77 siRNA-1, the G(0)/G(1) phase cell ratio of H1299 siRNA-1 group [(71.86±3.46)%] was higher than those of H1299-control group [(47.62±5.48)%] and H1299 siRNA-NC group [(61.38±5.62)%, P<0.05], S phase cell ratio of H1299 siRNA-1 group [(14.99±3.61)%] was lower than those of H1299-control group [(34.95±7.05)%] and H1299 siRNA-NC group [(23.75±5.87)%, P<0.05], the apoptosis rate of H1299 siRNA-1 group [(4.90±1.80)%] was higher than those of H1299-control group [(3.30±0.80)%] and H1299 siRNA-NC group [(2.80±1.20)%, P<0.05], the colony formation rate of H1299 siRNA-1 group [(19.20±2.00)%] was lower than those of H1299 control group [(32.60±2.00)%] and H1299 siRNA-NC group [(34.40±1.00)%, P<0.05]. The results of the nude mice tumor formation experiment showed that the tumor volume of the H1299 siRNA-1 group was significantly lower than those of the H1299-control group and the H1299-negative control group (P<0.05), the average tumor weight of H1299 siRNA-1 group was significantly lower than those of H1299-control group and H1299-negative control group (P<0.05), tumor cell growth marker Ki-67 in the H1299 siRNA-1 group showed weak positive, and Ki-67 in the H1299-control group and H1299-negative control group showed positive. The result of qRT-PCR analysis showed that the mRNA expression level of p21 in H1299 siRNA-1 group (2.57±0.45) was higher than those in H1299 control group (1.00±0.00, P=0.001) and H1299 siRNA-NC group (1.52±0.37, P=0.009). The result of western blotting analysis also showed that the expression of p21 protein level in H1299 siRNA-1 group increased. Conclusions: The expression of ultraconserved long non-coding RNA uc.77 is elevated in lung cancer cell lines and lung cancer tissues. Silencing the expression of ultraconservative long noncoding RNA uc.77 can inhibit tumor growth, and blocking uc.77 expression may be a potential therapeutic target for lung cancer.

[Clinicopathological features of clear cell carcinoma of salivary gland in the head and neck].

Objective: To investigate the clinical, histologic, immunohistochemical (IHC) and molecular genetic features of clear cell carcinoma (CCC) of salivary gland in the head and neck regions. Methods: Seven cases of CCC diagnosed in the Department of Pathology, the First Affiliated Hospital of Nanjing Medical University from 2018 to 2021 were included. The clinical and pathologic data, HE sections and IHC staining were reviewed, and EWSR1 gene translocation was detected by fluorescence in situ hybridization (FISH). The relevant literature was also reviewed. Results: There were five males and two females, with an age range of 32 to 71 years (mean 50 years). The tumors were located in the palate, base of tongue, subglottic, right submaxillary and nasopharynx. Histologically the tumors were composed of sheets, nests, and trabecular of large, monomorphic cells which possessed abundant clear and eosinophilic cytoplasm. The stroma was characterized by abundant hyalinized fibrous strands admixed with cellular fibrous (desmoplastic) tissue. The tumor growth was infiltrative. IHC staining revealed positivity for CKpan and squamous cell immunophenotypic markers (CK5/6, p63 and p40), but negativity for myoepithelial markers (SMA, calponin, GFAP and CD10). The EWSR1 gene translocation was detected by FISH. The prognosis was excellent, with the follow-up periods ranging from 8 months to 33 months. During this period, six patients survived without tumor, only one patient with cervical lymph node metastasis. Conclusions: CCC of salivary gland is rare and needs to be differentiated from various other types of tumors containing clear cells. Awareness of the histopathologic characteristics, and combined with IHC and molecular genetic examination can avoid misdiagnosis. The biological behavior of the tumor is indolent with a good overall prognosis.

[Clinicopathological features of ectopic meningothelial hamartoma].

Objective: To investigate the clinicopathological features, diagnosis and differential diagnosis of ectopic meningothelial hamartoma (EMH). Methods: Three cases of EMH diagnosed in the First Affiliated Hospital of Nanjing Medical University from January 2014 to December 2020 were enrolled. All cases were evaluated by clinical and imaging features, HE and immunohistochemical staining, and the relevant literature was reviewed. Results: There were one male and two female patients, aged 2, 67 and 19 years, respectively. Clinically, they presented as skin masses in the head and face region (two cases) and sacro-coccygeal region (one case). Grossly, the lesions ranged in size from 1.6 cm to 8.9 cm. Microscopically, the lesions were ill-defined, and located in the dermis and subcutis, and showed pseudovascular channels lined by monolayer of cuboidal to flattened epithelium with mild atypia, with variable cystic cavity formation. There was prominent interstitial fibrosis. Concentric, lamellated, onion skin-like arrangement with short spindle or ovoid cells and psammoma bodies were noted. Immunohistochemically, these cells were strongly positive for SSTR2, EMA, vimentin and progesterone receptor. Ki-67 positive index was low, approximately 1%. Conclusions: EMH is uncommon. Definitive diagnosis relies on histopathologic examination. The importance in recognizing the lesions is to differentiate from other more aggressive tumors.

[Current status and prospects of population exposure assessment of nanomaterials consumer products].

With the wide application of nanomaterials in consumer products in the market, it is necessary to understand the existence and release of nanomaterials in consumer products, as well as the current situation of exposure assessment of consumers. China has been a large industrial producer with a huge consumer market, but the supervision of consumer goods with nanomaterials is almost blank. This article summarized and classified the existing consumer products of nanomaterials in the international market, and discussed the release of key nanomaterials in consumer products and the exposure assessment methods of consumers, in order to provide a scientific basis for the establishment of a regulatory system for consumer products of nanomaterials in China in the future.

[Association between interleukin-17A and 17F single nucleotide polymorphisms and knee osteoarthritis].

Objective: To investigate the association between single nucleotide polymorphisms (SNP) of IL-17A (rs2275913) and IL-17F (rs763780) genes and susceptibility to knee osteoarthritis (KOA) in Chinese Han and Tibetan populations. Methods: A case-control study was conducted. Total of 122 Han KOA patients and 124 Han healthy controls and 76 Tibetan KOA patients and 68 Tibetan healthy controls in Qinghai Province were selected between 2015 and 2017. SNP typing was performed on four groups of rs2275913 and rs763780 polymorphisms by polymerease chain reaction (PCR)-sequencing to detect IL-17A and IL-17 F genotype frequencies and allele frequencies. The t test was used to compare data between groups. Results: The genotype AA frequency of IL-17A (rs2275913) was significantly different between the Han KOA and the control group (OR=2.625, P=0.016). Compared with the frequency of allele A in healthy control group, the allele A frequency in Han KOA group was significantly higher(OR=1.445, P=0.047); the genotype frequency of IL-17A,however,was comparable between the KOA and the healthy control in Tibetan population (OR=1.696, 1.355, both P>0.05); there were also not difference in the IL-17F (rs763780) genotype frequency and allele frequency between the Han KOA and Tibetan KOA groups and two control groups,respectively (OR=1.346, 1.126, both P>0.05). Conclusion: It is highly likely that the pathogenesis of KOA in Chinese Han population is positively related to the genotype AA and allele A of IL-17A (rs2275913).

Dose- and type-dependent effects of long-chain fatty acids on adipogenesis and lipogenesis of bovine adipocytes.

Differentiation and lipid metabolism of adipocytes have a great influence on milk performance, health, and feed efficiency of dairy cows. The effects of dietary long-chain fatty acids (FA) on adipogenesis and lipogenesis of dairy cows are often confounded by other nutritional and physiological factors in vivo. Therefore, this study used an in vitro approach to study the effect of dose and type of long-chain FA on adipogenesis and lipogenesis of bovine adipocytes. Stromal vascular cells were isolated from adipose tissue of dairy cows and induced into mature adipocytes in the presence of various long-chain FA including myristic, palmitic, stearic, oleic, or linoleic acid. When concentrations of myristic, palmitic, and oleic acids in adipogenic mediums were 150 and 200 µM, the induced mature adipocytes had greater lipid content compared with other concentrations of FA. In addition, mature adipocytes induced at 100 µM stearic acid and 300 µM linoleic acid had the greatest content of lipid than at other concentrations. High concentrations of saturated FA were more toxic for cells than the same concentration of unsaturated FA during the induction. When commitment stage was solely treated with FA, the number of differentiated mature adipocytes was greater for oleic and linoleic acids than other FA. When the maturation stage was treated with FA, the number of mature adipocytes was not affected, but the lipid content in adipocytes was affected and ranked oleic > linoleic > myristic > stearic > palmitic. In summary, this study showed that adipogenesis and lipogenesis of bovine adipocytes were differentially affected by long-chain FA, with unsaturated FA more effective than saturated FA.

[A cross-sectional study of seroepidemiology of viral hepatitis among Uighurs in Shufu of Xinjiang].

Objective: To explore the status of seroepidemiology on hepatitis A, B and C among students and residents aged equal or greater than 18 years in south Xinjiang, and to provide scientific evidence for prevention and control of viral hepatitis. Methods: Uyghur students in four towns and villages were selected by cluster random sampling from Feb to May, 2015, and Uyghur residents aged 18 to 69 years were selected by stratified cluster sampling from May to September, 2016. 4 507 middle and primary Uygur students and 4 833 Uyghur resides equal or greater than 18 years attended this survey. Self-designed questionnaire was used to collect the demographic information. And Elisa test was adopted to detect HAV-IgG, HBsAg, HBsAb and HCV-IgG. Chi-square test was used to calculate the difference on antibody positive rate of three types of hepatitis among the participants. Results: The overall HAV-IgG positive rate was 99.45% (9 289/9 340). The positive rates were 99.70% (4 006/4 018) in male and 99.27% (5 283/5 322) in female (χ(2)=7.95, P=0.005). The HAV-IgG positive rate among people aged 10 to 14 years was the highest (99.91%, 2 233/2 235), and the difference between the age specific HAV-IgG positive rates was statistical significant (χ(2)=38.21, P<0.001). The overall HBsAg positive rate was 4.11% (384 cases), with 4.55% (183 cases) for male and 3.78% (201 cases) for female. The HBsAg positive rate among participants 19 to 24 years old was the highest (9.46%, 21/222) and the differences between the age specific HBsAg was statistically significant (χ(2)=116.22, P<0.001). The HBsAb positive rate was 35.03% (3 272 cases), with 35.59% (1 430 cases) for male and 34.61% (1 842 cases) for female, and the HBsAb positive rate among participants aged 15 to 18 years was the highest, which was 69.12% (696/1 007). The differences between the age specific HBsAb rates appeared statistically significant (χ(2)=671.80, P<0.001). The overall HCV-IgG positive rate was 0.65%(61 cases). The HCV-IgG positive rate in female was 0.86% (46 cases) and 0.37% (15 cases) in male (χ(2)=8.51, P=0.004).The HCV-IgG positive rate among participants aged over 70 years was the highest (3.78%,9/238) , and the difference between the age specific HCV-IgG positive rates had statistic significance (χ(2)=70.30, P<0.001). The HAV-IgG positive rate in hepatitis A vaccinees (100%, 876/876) was higher than that among the non-vaccinees (99.40%, 8 413/8 464) (χ(2)=4.26, P=0.039). The HBsAb positive rate in hepatitis B vaccinees was 39.32% (1 816/4 619) which was higher than that among the non-vaccinees (30.84%, 1 456/4 721) (χ(2)=73.68, P<0.001). Conclusion: The positive rate of overall HAV-IgG was high, male and participants aged between 10 to 14 had higher probability to be infected. But the infection rates of hepatitis B and C were low, with the low vaccination rate and the poor protective effectiveness of hepatitis B.

[Association between variations in protocadherin 15 gene and occupational noise-induced hearing loss].

Objective: The aim of this study was to investigate whether genetic variability in the protocadherin 15 (PCDH15) gene may correspond with increased susceptibility to noise-induced hearing loss (NIHL) in a Chinese population. Methods: A nested case-control study was performed that followed a cohort of 7 445 noise-exposed workers in a steel factory of Henan province in China from January 1, 2006 to December 31, 2015. In this study, 394 cases who had an average hearing threshold of more than 40 dB (A) in high frequency were defined as the case group, and 721 controls who had an average hearing threshold of less than 35 dB (A) in high frequency and less than 25 dB (A) in speech frequency were defined as the control group. A questionnaire was completed by participants and a physical test was also conducted. SNP genotyping was performed using the SNPscanTM Kit. Multivariate unconditional logistic regression additive models were used to analyze the genotypes in different groups, and the association with NIHL. Unconditional logistic regression models were used to assess the associations between the genotypes and NIHL. Results: The average age of study participants was (40.5±8.3) years and the median number of noise-exposed working years M (P25, P75) was 21.1 (9.1, 27.3). The range of noise exposed levels and the levels of cumulative noise exposure (CNE) were 80.1- 98.8 dB(A) and 86.6- 111.2 dB(A), respectively. Only the distribution of the genotypes (TT/CC/CT) of rs11004085 in the PCDH15 gene showed a significant difference between the case and control groups (P=0.049). In the case group, the distribution was 370 (93.9%), 24 (6.1%) and 0; in the control group, the distribution was 694 (96.3%), 23 (3.2%) and 1 (0.1% ). After smoking, drinking, hypertension, height and CNE adjustment, compared with the TT genotype individuals with the CC/CT genotype had a 1.90-fold increased risk of NIHL (95% CI: 1.06- 3.40). After stratified these data by the noise exposure level or CNE when the noise exposure level was>85 dB (A), compared with cases with the AA genotype of rs10825113, individuals with the GA/GG genotype had a 2.63-fold increased risk of NIHL (95% CI: 1.12- 6.14). When the CNE was ≤ 98 dB(A), compared with cases with the TT genotype of rs11004085, individuals with the CC/CT genotype had a 2.96-fold increased risk of NIHL (95% CI: 1.33- 6.56). However, these differences were not significant after Bonferroni correction had been applied. Conclusions: The results confirmed that genetic variation within the PCDH15 gene may affect the susceptibility to NIHL.

[Association between eye absent homolog 4 gene polymorphisms and occupational noise-induced hearing loss].

Objective: To identify the association between genetic polymorphisms in the eye absent homolog 4 (EYA4) gene and noise-induced hearing loss (NIHL). Method: A nested case control study was conducted based on a cohort of noise-exposed subjects. In total, 292 cases were selected from a steel factory from 6 297 subjects during Jan 1, 2006 to Dec 12, 2015,who had an average hearing threshold of more than 40 dB(A); 584 matched control subjects for each case were designated on the basis of matched criteria including same gender, age (±5 years) and duration of exposure to noise (±2 years). What's more, the control group had an average hearing threshold of less than 35 dB(A) in high frequency and less than 25 dB(A) in speech frequency. Four single nucleotide polymorphisms (SNPs) of the EYA4 gene were genotyped using a SNPscanTM multiplex SNP genotyping kit. Hardy-Weinberg equilibrium tests were performed using a χ2 test for goodness-of-fit for each SNP among the control group, and the effects of genotypes of the EYA4 gene on NIHL were analyzed by logistic regression. The haplotypes were established and their frequencies in the two groups were assessed using Haploview 4.2 and Phase 2.1 software, and interactive effects between haplotypes and cumulative noise exposure were analyzed. Results: The average age of the subjects was (40.1±8.4) years and the average number of noise-exposed working years was 20.3 (8.4, 27.3) years. The range of noise exposure levels and the cumulative noise exposure were 80.2- 98.8 dB (A) and 86.6- 111.2 dB(A) · year, respectively. After adjustment for covariates including height, blood pressure, drinking status and smoking status, in the noise intensity>85 dB (A) group, subjects carrying the rs3813346 TT genotype had a higher NIHL risk than those carrying the GG genotype, and the adjusted OR (95% CI) value was 2.12 (1.21- 3.69). In the cumulative noise exposure>98 dB (A) · year group, compared with haplotype TGC, haplotype CGT showed a protective effect in the development of NIHL, with an adjusted OR (95% CI) value of 0.60 (0.37-0.97), however, the significance of intercation between EY4 gene of noise was lost after Bonferroni correction. Conclusion: Genetic polymorphism in the EYA4 gene may be a genetic susceptibility factor for NIHL.

[Investigation into the relationship between mitochondrial 12 S rRNA gene, tRNA gene and cytochrome oxidase â ¡ 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.