Impact of occupational noise exposure on the hearing level in hospital staffs: a longitudinal study.

The study aimed to evaluate the impact of occupational noise on hearing loss among healthcare workers using audiometry. A longitudinal study was conducted with a six-month follow-up period in a hospital with 21 participants, divided into high-noise-exposure (HNE) and low-noise-exposure (LNE) groups. Mean noise levels were higher in the HNE group (70.4 ± 4.5 dBA), and hearing loss was measured using pure-tone audiometry at baseline and follow-up. The HNE group had significantly higher mean threshold levels at frequencies of 0.25 kHz, 0.5 kHz, 4.0 kHz, and an average of 0.5, 1, 2, and 4 kHz (all p-values < 0.05) after the follow-up period. After adjusting for confounding factors, the HNE group had significantly higher hearing loss levels at 0.25 kHz, 0.5 kHz, and average frequencies of 0.5, 1, 2, and 4 kHz compared to the LNE group at the second measurement. Occupational noise levels above 65 dBA over six months were found to cause significant threshold changes at frequencies of 0.25 kHz, 0.5 kHz, and an average of 0.5-4.0 kHz. This study highlights the risk of noise-induced hearing loss among healthcare workers and emphasizes the importance of implementing effective hearing conservation programs in the workplace. Regular monitoring and assessment of noise levels and hearing ability, along with proper use of personal protective equipment, are crucial steps in mitigating the impact of occupational noise exposure on the hearing health of healthcare workers.

Alveolar Bone Morphologic Predictors for Guided Bone Regeneration Outcome in Anterior Maxilla.

OBJECTIVES: This study aimed to explore the influence of alveolar bone morphologic variables on the outcome of guided bone regeneration (GBR) in the anterior maxilla region. METHODS: Twenty-eight patients who received single maxillary anterior tooth delayed implant placed simultaneously with GBR were recruited. Baseline data including age, gender, implant site, implant brand, and bone graft materials were recorded. The resorption rate of the grafted bone (RRGB), labial bone width at 0 mm, 2 mm, and 4 mm apical to the implant platform at Tn (LBW0Tn, LBW2Tn, LBW4Tn), implant angulation (IA), maximum bone graft thickness (MBGT), bone graft volume (BGV), and the initial bone morphologic variables bone concavity depth (BCD) and bone concavity angulation (BCA) were measured. The Pearson correlation analysis, analysis of variance (ANOVA), and optimal binning method were used to explore the potential predictors for GBR. RESULTS: Among 28 patients, the labial bone width of implant and bone graft volume decreased significantly when measured 6 months after surgery. The mean percentage of RRGB was 49.78%. RRGB was not correlated with gender, age, bone graft material, IA, MBGT, bone graft volume at T1, implant site, and implant brand (P > .05). BCD and BCA were each moderately correlated with RRGB (r = -0.872 [P < .001] and r = 0.686 [P < .001], respectively). A BCD ≥1.03 mm and a BCA <155.30° resulted in a significantly lower percentage of RRGB (P < .001). CONCLUSIONS: A significant grafted bone materials volume reduction was detected after GBR with collagen membrane and deproteinized bovine bone mineral (DBBM). The initial bone morphology can influence GBR outcome, and a bone concavity with a depth ≥1.03 mm and an angulation <155.30° led to a lower RRGB. BCD and BCA can be used as variables to predict the outcome of GBR.

A comprehensive finite-element human ear model to estimate noise-induced hearing loss associated with occupational noise exposure.

BACKGROUND AND OBJECTIVE: Noise is a common occupational and environmental hazard; however, little is known about the use of computational tools to quantitively analyze data on basilar membrane (BM) damage in noise-induced hearing loss (NIHL). Here, we established a comprehensive three-dimensional finite-element human ear model to quantify the impact of noise exposure on BM and perilymph fluid. METHODS: We used auditory risk units (ARUs) to evaluate the BM damage for subjects (3 men and 5 women; mean age, 32.75 ± 8.86 years; age range, 24-44 years). A 90-dB sound pressure level (SPL) was normally applied at the external auditory canal (EAC) entrance to simulate sound transmission from the EAC to the cochlea at frequencies of 0.2-10.0 kHz. RESULTS: The pressure distribution of perilymph fluid is totally different on frequency responses under low and high sound-evoked (0.013-10.0 kHz). The highest ARUs were 18.479% at the distance of 1 mm from the base, and the second-highest to fourth-highest ARUs occurred at distances of 5-7 mm from the base, where their ARUs were 9.749%, 9.176%, and 11.231%. The total of the ARUs reached 81.956% at external frequencies' sounds of 3.2-5.0 kHz. Among these, the 3.8-kHz and 3.6-kHz frequencies yielded the highest and second-highest ARUs of 20.325% and 19.873%, respectively. CONCLUSIONS: This study would inform our understanding of NIHL associated with occupational noise exposure. We present a FE modelling and describe how it might provide a unique way to unravel mechanisms that drive NIHL due to loud noises.

[Effect of silencing LASP1 on biological behaviors of oral squamous cell carcinoma cells and IC50 of three anti-tumor drugs].

PURPOSE: This study was designed to investigate the effects of LASP1 on proliferation, metastasis, invasion, and cycle of oral squamous cell carcinoma cells and analyze the changes of IC50 in three antitumor drugs: cisplatin, apatinib and docetaxel. METHODS: The correlation between LASP1 and survival rate and prognosis of patients with head and neck cancer were analyzed on the human protein atlas data. RT-PCR and Western blot were used to detect mRNA and protein expression of LASP1 in oral squamous cell carcinoma cell lines. LASP1 silenced HN30 stable transfectant cell line was constructed by lentivirus. CCK-8 assay was used to detect cell proliferation. Plate colony assay was used to detect cell clone formation ability. Transwell assay was used to detect cell migration and invasion ability. Flow cytometry was used to detect cell cycle changes. Oral squamous cell carcinoma metastases were established in nude mouse, the number of metastatic lung nodules was counted and stained with H-E. CCK-8 method was used to analyze the changes of IC50 in three antitumor drugs: cisplatin, apatinib and docetaxel. Statistical analysis was performed using SPSS 11.0 software package. RESULTS: LASP1 was closely related to the survival rate and prognosis of head and neck cancer. LASP1 promoted proliferation, colony formation, metastasis and invasion of oral squamous cell carcinoma cell line HN30, promoted G2/M phase transition of cell cycle, and significantly reduced the formation of lung metastasis in nude mice after silencing. There was significant correlation with docetaxel IC50 but no significant impact on cisplatin IC50 and aptatinib IC50. CONCLUSIONS: LASP1 enhances cell proliferation, plate cloning, metastasis and invasion, G2/M phase transition of cell cycle, promotes lung metastasis in nude mice and docetaxel resistance of oral squamous cell carcinoma cell line HN30.

Cytoplasmic c-ros oncogene 1 receptor tyrosine kinase expression may be associated with the development of human oral squamous cell carcinoma.

The c-ros oncogene 1 receptor tyrosine kinase (ROS1) gene encodes a proto-oncogenic protein that has been demonstrated to be involved in the pathogenesis of several types of cancer. The present study aimed to analyze the expression of ROS1 in human oral squamous cell carcinomas (OSCCs), and investigate the association between its expression and the clinicopathological parameters of patients with OSCC. Paraffin-embedded OSCC tissues from 31 patients were obtained and the expression of ROS1 was analyzed by immunohistochemistry. The cellular location of ROS1 was determined by immunofluorescence in human oral cancer CAL-27 cells. The association of clinicopathological characteristics and survival rates with ROS1 expression were assessed. The results revealed that ROS1 was exclusively localized in the cytoplasm of the OSCC tissues (24/30, 80.0%), and in the cytoplasm of adjacent dysplastic epithelial tissues (2/15, 13.3%) (P<0.001). The moderate to strong expression of ROS1 in the cytoplasm was higher in OSCC tissues than in the normal epithelial tissues adjacent to the tumor (67.7 vs. 0%, P=0.001). The results of the Kaplan-Meier analysis and multivariate Cox regression analysis indicated that there was no association between the 5-year survival rate of patients and the cytoplasmic (P=0.28 and P=0.60, respectively) or nuclear expression (P=0.90 and P=0.31, respectively) of ROS1. These results suggest that the cytoplasmic expression level of ROS1 may be associated with the development of OSCC.

Bioinformatics analysis reveals significant genes and pathways to target for oral squamous cell carcinoma.

PURPOSE: The purpose of our study was to explore the molecular mechanisms in the process of oral squamous cells carcinoma (OSCC) development. METHOD: We downloaded the affymetrix microarray data GSE31853 and identified differentially expressed genes (DEGs) between OSCC and normal tissues. Then Gene Ontology (GO) and Protein-Protein interaction (PPI) networks analysis was conducted to investigate the DEGs at the function level. RESULTS: A total 372 DEGs with logFC| >1 and P value < 0.05 were obtained , including NNMT, BAX, MMP9 and VEGF. The enriched GO terms mainly were associated with the nucleoplasm, response to DNA damage stimuli and DNA repair. PPI network analysis indicated that GMNN and TSPO were significant hub proteins and steroid biosynthesis and synthesis and degradation of ketone bodies were significantly dysregulated pathways. CONCLUSION: It is concluded that the genes and pathways identified in our work may play critical roles in OSCC development. Our data provides a comprehensive perspective to understand mechanisms underlying OSCC and the significant genes (proteins) and pathways may be targets for therapy in the future.

[Expression and clinical significance of ErbB3 binding protein ebp1, E-cadherin, ICAM-1 and matrix metalloproteinase-9 in salivary adenoid cystic carcinoma].

PURPOSE: To investigate the expression of ErbB3 binding protein ebp1, E-cadherin, ICAM-1 and matrix metalloproteinase-9(MMP-9) in salivary adenoid cystic carcinoma(SACC), and to explore their relationship with clinical pathological features. METHODS: Two-step immunohistochemical staining method was used to detect the expression of ebp1 E-cadherin, ICAM-1 and MMP-9 in 33 cases with human SACC and 33 with para-cancerous normal tissues. All data were analyzed with SPSS17.0 software package. RESULTS: Positive expression rate of ebp1 in SACC was 84.85%, lower than in normal salivary tissues(96.97%). Ebp1 expression was significantly correlated to pathological pattern and clinical stage(P<0.05), but not correlated to gender and age. Positive expression rate of ebp1 at I-II stage was higher than that of SACC at III-IV stage; in regard to pathological typing, higher expression was found in adenoid tubular type than in solid type; the positive expression rate in patients with tumor metastasis was lower than in patients without metastasis (P<0.05). Expression of ebp1 had a positive relationship with E-cadherin (r=0.851,P<0.01), while a negative relationship was found with MMP-9 (r=-0.364,P<0.05). CONCLUSIONS: Expression of ebp1 may be associated with progression of SACC. Ebp1 has important role in the generation and evolution of adenoid cystic carcinoma, and can be used as a useful indicator for clinical assessment of tumor biological behavior and prognosis in patients with adenoid cystic carcinoma.

[Expression of erythroblastic leukemia viral oncogene homolog 3 (ErbB-3) binding protein-1, matrix metalloproteinases, eplthelial cadherin in adenoid cystic carcinoma and correlation analysis].

OBJECTIVE: To investigate the expression of ErbB-3 binding protein-1 (EBP-1), matrix metalloproteinase 9 (MMP-9) and E-cadherin (E-cad) in adenoid cystic carcinoma and their correlation. METHODS: Immunohistochemistry(PV6000 method) was used to detect EBP-1, MMP-9 and E-cad expression in 66 cases of adenoid cystic carcinoma tissues and matched para-cancerous normal tissues. In this study all cases were successfully followed up. RESULTS: The positive expression rate of EBP-1 in adenoid cystic carcinoma tissues was 85%. EBP-1 expression was significantly correlated to pathological pattern and clinical stage (P < 0.05), but not to gender and age. In addition, there was a negative correlation between EBP-1 and E-cad expression, and positive correlation between EBP-1 and MMP-9. CONCLUSIONS: EBP-1 and its correlation with MMP-9 and E-cad may be used as useful indicators for clinical assessment of tumor biological behavior and prognosis in patients with adenoid cystic carcinoma.

[Effect of BMP-2 on osteogenesis of bone mesenchymal stem cells in rats].

PURPOSE: To determine the effect of bone morphogenetic protein-2(BMP-2) on osteogenesis of bone mesenchymal stem cells(BMSCs) in rats. METHODS: The primary culture of rat BMSCs was succeeded and then was identified. The rat BMSCs were infected with the recombinant lentivirus with BMP-2(Lenti-BMP-2). The osteogenic effect of BMP-2 was observed. In addition, adhesive ability of BMP-2-BMSCs was detected through adhesion assay and expression of osteogenic factors OPN,OCN,Col-I and smad was observed by RT-PCR and Western blot. SPSS11.0 software package was used for analysis. RESULTS: Rat BMSCs were cultured and identified successfully. The osteogenic effect of BMSCs was improved by BMP-2. Lenti-BMP-2 BMSCs adhesive potential enhanced and osteogenic factors were up-regulated. CONCLUSIONS: BMP-2 may facilitate the osteogenic effect of the rat BMSCs and would provide favourable cell resource for tissue engineering.

[Role of transcription factor special AT-rich binding protein 2 in the osteoblasts differentiation of bone marrow stromal cells].

OBJECTIVE: To investigate the role of transcription factor special AT-rich binding protein 2 (SATB2) in the osteoblasts differentiation of bone marrow stromal cells (BMSC) in vitro. METHODS: Rats bone marrow stromal cells were isolated by Percoll sedimentation and the cells were placed and allowed to attach for three times. After passages, expression plasmid pBABE-hygro-satb2 was constructed, then transfected into BMSC. BMSCs were inoculated in conditioned medium and osteogenic factors were detected by western blotting and reverse transcription polymerase chain reaction (RT-PCR). RESULTS: The morphological observation of BMSC showed either spindle or polygonal pattern. The cellular phenotypic marker of the third passage was CD29 positive and CD34 negative. The growth curve possessed "S" pattern. The intensity of calfilication in BMSC was higher in SATB2 transfection group (IA value 125974 ± 241) than that in the control groups (IA value 178486 ± 406). Moreover, cell migration rate increased in SATB2 transfection group [width of scratch (0.72 ± 0.01) mm] compared with control group [width of scratch (0.83 ± 0.03) mm]. In addition, the mRNA expression of osteogenic factors runt-related transcription factor 2, Osterix, activating transcription factor 4, integrin-binding sialoprotein were upregulated. CONCLUSIONS: Cells cultured with this method have general biological characteristics and osteogenic differentiation potential in vitro. SATB2 can promote osteoblasts differentiation of BMSC.

Eleven dental implants placed in a liver transplantation patient: a case report and 5-year clinical evaluation.

Due to an increased risk of infection, dental implant in organ transplantation patients has long been considered questionable, particularly when the restoration is complicated. Five-year follow-up data of a 45-year-old liver transplant recipient with long-term immunosuppressive therapy was reported. One year after liver transplantation, 11 Brånemark implants were inserted in the maxilla and mandible, using minimally invasive surgery. Oral clinical parameters included peri-implant bone absorption, probing depth, and implant mobility. The measured fifth-year parameters were within normal ranges indicating a stable osseointegration with moderate vertical bone loss. This case report suggests that immunocompromised patients can be successfully rehabilitated with dental implants through careful examination, suitable antibiotic administration, and minimally invasive dental implant procedure.

[Clinical evaluation of two-implant-supported single molar restoration].

PURPOSE: This study was to evaluate the clinical effect of two-implant-supported single molar restoration with wider interdental space. METHODS: 32 subjects who presented 38 single molar missing with wider interdental space were involved in this study. Two-implant-supported single molar restoration was performed with Branemark system or Replace system. The stability of the implant restoration, periodontal condition, and peri-implant bone absorption were investigated 3 months, 1 year and 3 years after restoration. The periodontal condition was analyzed by Wilcoxon signed rank test or Chi-square test and the peri-implant bone absorption was analyzed by paired t test using SPSS13.0 software package. RESULTS: Among 76 implants, one implant was lost in 2 weeks after surgery, which had been re-implanted successfully 3 months later. After loading, the survival rate of 76 implants was 100% during the next three years with perfect osseointegration. No significant differences for the plaque index, bleeding on probing, probing depth were found 3 months, 1 year and 3 years after restoration (P>0.05). The bone absorption of peri-implant was (0.56+/-0.14)mm at 3-month and stable trends were shown at 1 year (0.15+/-0.05)mm and 3 years (0.17+/-0.06)mm, both of which were significantly lower than that at 3-month (P<0.05). CONCLUSION: Two-implant-supported single restoration is suitable for single molar missing with wider interdental space.

[The effect of icariin and astragalosid I on the proliferation and differentiation of bone marrow stromal cells].

OBJECTIVE: To observe the effects of icariin and astragalosid I on the proliferative and alkaline phosphatase (ALP) activity of dog bone marrow stromal cells (BMSCs). METHODS: The dog's BMSCs were isolated and cultured in vitro. The 3th generation BMSCs were treated with icariin or astragalosid I at the concentration of 50 ng/ml and compared with BMSCs of BMP-2 group and control group. The growth curves of BMSCs were drawn by 3-(4,5-dimiethylthiazole-2-yl)-2, 5-hiphenyl tetrazolium bromide (MTT) colorimetric assay every day from the 1st to the 8th day to estimate the proliferative ability of BMSCs. The curves of OD value of ALP excreted by BMSCs on the 1st, 3th, 6th, 10th and the 14th day were recorded to estimate the ALP activity of BMSCs. RESULTS: After the pertreatment with icariin and astragalosid I, the BMSCs acquired higher MTF values and higher ALP's OD values as compared with control group and the difference between experiment group and control group was statistically significant (P < 0.05). CONCLUSION: Icariin and Astragealosid I can accelerate the proliferation and ALP excretion of BMSCs. At the same time, the osteogenesis ability of these cells is greatly improved.

[Application of Bränemark system's multi-unit abutment: report of 37 consecutive cases].

PURPOSE: To evaluate the short-term clinical effect and advantages of Bränemark system's multi-unit abutment used for standard or MK III implants supported fixed prosthodontics. METHODS: Routine clinical examinations and preparations, including panoramic tomography, periapical radiograph and surgical guide plate, were performed in 37 cases with multiple lost teeth. A total of 117 Bränemark system's implants were placed using a two-stage surgical approach. Multi-unit abutment connection was performed 3-6 months after implant installation. All superstructure prosthetic appliances were porcelain-fused-to-golden metal bridges. RESULTS: The follow-up period for the implants was 12 to 24 months. The total survival rate was 95.7%. Two implants were lost at second-stage surgery (the survival rate was 98.29% for first-stage), and 3 implants were lost after loading (the survival rate was 97.43% for second-stage). The other 112 implants function uneventfully. There were no bone loss around implants, no abutment and gold cylinder screw loosen. CONCLUSIONS: The multi-unit abutment, on basis of collecting all the merits of the traditional abutment, was further designed in a simplified way, which not only expands its clinical application, operate easily, but also enhance its whole superstructure. It is more suitable for implant supported fixed prosthodontics with high success rate and more advantages than the traditional abutment.

[Cloning of p53/p21 fusion gene and it's inhibitory effect on the growth in Tca8113 cells].

OBJECTIVE: To study the p53/p21 fusion gene as a potential fusion gene for the gene therapy of human oral squamous cell carcinoma. METHODS: p21 cDNA was obtained from normal human embryonic lung cells by RT-PCR, fusing with p53 gene. The recombinant plasmid pcDNA-p53/p21 was constructed by inserting the p53/p21 fusion gene into eukaryotic expression vector pcDNA3.1 and subsequently transfected into human oral squamous cell carcinoma cell line (Tca8113) with lipofectamine. RT-PCR and Western blot were used to demonstrate the expression of p53/p21 fusion gene. Using clonal formation experiment and (3)H-TdR incorporation assay were used to evaluate the clonal formation and proliferation ability of Tca8113 cells. RESULTS: It was observed that p53/p21 fusion gene could inhibit clonal formation and proliferation of human oral carcinoma. RT-PCR and Western blot demonstrated that it was the expression of exogenous p53/p21 fusion gene that led to the above results. CONCLUSIONS: Transfection of p53/p21 fusion gene to Tca8113 cells could inhibit the tumor cell proliferation and clone formation in vitro, and make itself a potential fusion gene for the gene therapy of human oral squamous cell carcinoma.