Interleukin-13 promotes cellular senescence through inducing mitochondrial dysfunction in IgG4-related sialadenitis / 国际口腔科学杂志·英文版

Immunoglobulin G4-related sialadenitis (IgG4-RS) is an immune-mediated fibro-inflammatory disease and the pathogenesis is still not fully understood. The aim of this study was to explore the role and mechanism of interleukin-13 (IL-13) in the cellular senescence during the progress of IgG4-RS. We found that the expression of IL-13 and IL-13 receptor α1 (IL-13Rα1) as well as the number of senescent cells were significantly higher in the submandibular glands (SMGs) of IgG4-RS patients. IL-13 directly induced senescence as shown by the elevated activity of senescence-associated β-galactosidase (SA-β-gal), the decreased cell proliferation, and the upregulation of senescence markers (p53 and p16) and senescence-associated secretory phenotype (SASP) factors (IL-1β and IL-6) in SMG-C6 cells. Mechanistically, IL-13 increased the level of phosphorylated signal transducer and activator of transcription 6 (p-STAT6) and mitochondrial-reactive oxygen species (mtROS), while decreased the mitochondrial membrane potential, ATP level, and the expression and activity of superoxide dismutase 2 (SOD2). Notably, the IL-13-induced cellular senescence and mitochondrial dysfunction could be inhibited by pretreatment with either STAT6 inhibitor AS1517499 or mitochondria-targeted ROS scavenger MitoTEMPO. Moreover, IL-13 increased the interaction between p-STAT6 and cAMP-response element binding protein (CREB)-binding protein (CBP) and decreased the transcriptional activity of CREB on SOD2. Taken together, our findings revealed a critical role of IL-13 in the induction of salivary gland epithelial cell senescence through the elevated mitochondrial oxidative stress in a STAT6-CREB-SOD2-dependent pathway in IgG4-RS.

Target delineation and dosimetry analysis of 125I interstitial brachytherapy for recurrent adenoid cystic carcinoma in the parotid gland / 中华放射医学与防护杂志

Objective:To analyze the target design and dosimetric parameters of patients with recurrent adenoid cystic carcinoma (ACC) in the parotid gland who were treated with 125I interstitial brachytherapy alone. Methods:A retrospective analysis was conducted for 25 patients with recurrent adenoid cystic carcinoma in parotid gland who were histopathologically diagnosed between January 2015 and October 2019. These patients were treated with 125I interstitial brachytherapy alone, with prescribed doses of 100-120 Gy. The target volume was designed according to the pathological characteristics of ACC and recurrence sites. The pre- and post-operation dosimetric parameters (i.e., local control rates) were calculated using the treatment planning system. Results:In this study, the local recurrence sites included the superficial lobe (10/25) and deep lobe (7/25) of the parotid gland primarily and the skull base region (four patients) and mastoid posterior region (four patients) secondarily. The number of 125I seeds ranged from 16 to 111, with a median number of 59. The activity of radioactive particles was 18.5-25.9 MBq. The 3- and 5-year local control rates were 81.5% and 61.5%, respectively. No significant differences were found between pre- and post-operative dosimetric parameters such as D90, V100, and V150. There was no significant difference in local control rates among the four different recurrence sites. Conclusions:125I interstitial brachytherapy is proven to be an effective approach in the treatment of recurrent adenoid cystic carcinoma in the parotid gland. Satisfying local control rates can be achieved through target delineation performed according to recurrence sites and perineural invasion characteristics of ACC.

Conservative and functional surgery in the treatment of salivary gland tumours / 国际口腔科学杂志·英文版

The principle of modern oncological surgery is to conserve the functional organs or tissues as much as possible based on eradication of the tumour. For salivary gland tumours, conservative and functional salivary surgery, including partial sialoadenectomy as well as anatomical and functional preservation of the facial nerve, great auricular nerve, superficial musculo-aponeurotic system (SMAS), and Stensen's duct, has become increasingly popular. In the present review, we discuss the following aspects of conservative and functional surgery in the treatment of salivary gland tumours: (i) partial superficial parotidectomy (PP) to treat benign parotid gland tumours, (ii) modification of surgical incisions to improve cosmetic results, (iii) modification of the surgical approach to decrease complications, (iv) extracardial dissection to treat benign superficial parotid tumours, (v) partial sialoadenectomy to treat benign submandibular gland tumours, and (vi) I brachytherapy to preserve facial nerves. The majority of the operated parotid or submandibular glands are preserved, and surgical complications are also decreased. Conservative and functional surgery plays a significant role in maintaining normal salivary gland function and in improving patients' quality of life during the treatment of salivary gland tumours and thus should be further promoted.

Comparison of the secretory related molecules expression in stem cells from the pulp of human exfoliated deciduous teeth and dental pulp stem cells / 中华口腔医学杂志

Objective@#To compare the general biological characteristics and the expressions of proteins involved in secretion in stem cells from the pulp of human exfoliated deciduous teeth (SHED) and dental pulp stem cells (DPSC).@*Methods@#SHED and DPSC were cultured and collected at passage 4 (P4) and P7. The submandibular gland epithelial and interstitial cells were cultured with tissue culture method. The cell morphology was observed using a phase contrast microscope. Flow cytometry was used to detect stem cell surface markers. Cell counting kit-8 (CCK-8) and IncuCyte ZOOM were used to evaluate cell proliferation. Quantitative real-time PCR (qPCR) was performed to examine the mRNA expressions of proteins involved in fluid and protein secretion.@*Results@#P4 and P7 SHED and DPSC were spindle-shaped. There was no difference in cell morphology among the 4 group cells. P4 and P7 SHED and DPSC expressed CD29, CD44, CD73, and CD90, the mesenchymal stem cell markers, while, CD49f and CD117, the epithelium markers were undetected. There was no difference in cell proliferation among the 4 group cells. Compared with P4 SHED, the expressions of muscarinic cholinergic receptor 1 (MR1), MR3, aquaporin 5 (AQP5), β1-adrenoceptor (β1-AR), α-amylase, and mucin 5B in SHED were not different, while β2-AR expression was decreased (P<0.05). Compared with P4 DPSC, the expressions of MR3, β2-AR, and α-amylase in P7 DPSC were not different, while, the expressions of MR1, AQP5, β1-AR, and mucin 5B were decreased (P<0.05). Compared with primary cultured submandibular gland epithelial cells and gland tissues from a child, the expressions of proteins involved in secretion were all decreased. Compared with submandibular epithelial cells from adults, the expression of AQP5 in P4 DPSC was decreased (P<0.05), while other proteins were not different. The expressions of AQP5, β1-AR, α-amylase and mucin 5B in P7 DPSC were increased (P<0.05), while other proteins were not different. In P4 and P7 DPSC, all the protein expression levels were decreased, compared with those in submandibular gland tissues (P<0.01).@*Conclusions@#Compared with DPSC, SHED have stable growth and the expressions of protein involved fluid and protein secretion are low. Based on its extensive sources and easy separation, SHED can be used as the ideal seed cell for salivary gland tissue engineering and the treatment of salivary gland hypofunction, and the P4 to P7 SHED can be used for experimental study.

Autonomic reinnervation and functional regeneration in autologous transplanted submandibular glands in patients with severe keratoconjunctivitis sicca / 国际口腔科学杂志·英文版

Autologous submandibular gland (SMG) transplantation has been proved to ameliorate the discomforts in patients with severe keratoconjunctivitis sicca. The transplanted glands underwent a hypofunctional period and then restored secretion spontaneously. This study aims to investigate whether autonomic nerves reinnervate the grafts and contribute to the functional recovery, and further determine the origin of these nerves. Parts of the transplanted SMGs were collected from the epiphora patients, and a rabbit SMG transplantation model was established to fulfill the serial observation on the transplanted glands with time. The results showed that autonomic nerves distributed in the transplanted SMGs and parasympathetic ganglionic cells were observed in the stroma of the glands. Low-dense and unevenly distributed cholinergic axons, severe acinar atrophy and fibrosis were visible in the patients' glands 4-6 months post-transplantation, whereas the cholinergic axon density and acinar area were increased with time. The acinar area or the secretory flow rate of the transplanted glands was statistically correlated with the cholinergic axon density in the rabbit model, respectively. Meanwhile, large cholinergic nerve trunks were found to locate in the temporal fascia lower to the gland, and sympathetic plexus concomitant with the arteries was observed both in the adjacent fascia and in the stroma of the glands. In summary, the transplanted SMGs are reinnervated by autonomic nerves and the cholinergic nerves play a role in the morphological and functional restoration of the glands. Moreover, these autonomic nerves might originate from the auriculotemporal nerve and the sympathetic plexus around the supplying arteries.

Comorbidity in oral squamous cell carcinoma patients: an initial research in Beijing area / 中华口腔医学杂志

Objective@#To make a preliminery research of comobidity in oral squamous cell carcinoma (OSCC) patients who resides in Beijing area and investigate whether comorbidity affect the surviving rate independently. Compare the similarities and differences between Chinese and foreign OSCC patients.@*Methods@#The medical records of 313 patients who undertaken operation in Peking University Stomatology School from January 2007 to Delember 2009 were retrospectively reviewed. Adult comorbidity evaluation-27 Chinese edition index was used to estimate the comorbidity severity. COX proportional hazards model was used to analyze whether the TNM stage, comobidity, age and gender affected 5-year survival rate.@*Results@#TNM stage and comorbidity have a significant impact on survival rate, the postoperative survival rate decreased significantly with the increasing level of TNM staging and the complexity of comorbidity disease. In this study, the proportion of patients with none, mild, moderate and severe comorbidity diseases was 24%, 48%, 18% and 10%. The five-year survival rates of patients with moderate and severe comorbidity disease were 50% (29/58) and 13% (4/30) respectively.@*Conclusions@#The comorbidity disease information can help assess the overall health of OSCC patients, and it is recommended to improve the clinical staging and overall evaluation of oral cancer patients with comorbidity disease information.

Research progress of salivary glands mucosa-associated lymphoid tissue lymphoma / 中华口腔医学杂志

Salivary glands mucosa-associated lymphoid tissue lymphoma (SGML) is a distinct subtype of marginal zone B-cell type non-Hodgkin′s lymphoma (NHL), which is commonly seen in middle aged females. SGML is usually associated with autoimmune diseases such as Sjögren's syndrome or with chronic infection such as hepatitis C virus (HCV) infection. Chromosomal abnormalities are frequently seen in SGML, which usually activate nuclear factor-κB molecular pathway to modulate cell survival and proliferation, resulting in lymphoma occurrence. SGML tends to arise from parotid gland, presenting frequently as a localized and indolent lesion, a long-term follow-up and biopsy are needed for accurate diagnosis. Surgery, radiotherapy and chemotherapy are usually effective disseminated diseases at multiple sites need combined treatment. SGML has a relatively better prognosis with a higher relapse rate than other types of NHLs, dissemination or higher degree of malignant transformation may occur. Thus, a long-term and close follow-up is essential for patients with SGML.

Focus on the recent state policy for oral health in China / 中华口腔医学杂志

President Xi presented an important address in the National Health and Wellness Conference and the high strategic priority for promoting people's health in China was emphasized. Thereafter, a number of documents of state policy on health and wellness were issued successively. These documents covered important contents on oral health, which had great significance as a milestone. This article reviewed the documentation process and analyzed the key points on oral health. The release of these series of government documents had provided policy support for integrating oral health into significant health policies, building the first barrier for oral health, preventing and treating oral diseases based on strategies for common risk factors, adopting strategies to combine both the whole population and high-risk groups, and developing health-centered oral massive health industry, etc.

Paying attention to the protection of the function organ of submandibular gland / 中华口腔医学杂志

Submandibular gland is an important human function organ. With the wide application of sialoendoscope and new understanding of IgG4 related sialadenitis, a lot of submandibular glands which were previously considered to be removed are preserved. However, some submandibular glands which might be preserved are still unfortunately sacrificed. Therefore, we advocate the popularization and promotion of new knowledge and techniques and should pay more attention to the protection of the function organ of submandibular gland.

Expert consensus on induction of human embryonic stem cells into tenocytes / 浙江大学学报·医学版

Embryonic stem cells have unlimited proliferative capacity, which may provide a source of tendon stem/progenitor cells for tissue engineering. Experts of International Science and Technology Collaborative Program of Ministry of Science and Technology have developed a protocol consensus on differentiation of human embryonic stem cells into the tendon cells. The consensus recommends a protocol of two-step generation of human embryonic stem cells into tendon cells: the human embryonic stem cells are first differentiated into mesenchymal stem cells on different material surfaces; then with the scaffold-free tissue engineering tendon formed by high-density planting, the mesenchymal stem cells are induced into tendon cells under static or dynamic mechanical stimulation in vivo and in vitro. Tissue engineering tendon established in vitro by the protocol can be used as a model in toxicological analysis and safety evaluation of tendon-relevant small molecule compounds, medical materials and drugs.

Relationships between microRNA expressions and prognosis in patients with tongue squamous cell carcinoma and the mechanisms microRNA regulating tongue squamous cell carcinoma biological behavior / 北京大学学报(医学版)

SUMMARY Tonguesquamouscellcarcinoma(TSCC)isthemostcommontypeoforalcancerandis well known for its high rate of proliferation and lymph nodal metastasis.Exploring the underlying path-ways regulating TSCC could provide novel ideas for diagnosis and prognosis of TSCC patients,as well as molecular targets for treatment of TSCC.MicroRNAs (miRNAs)are small noncoding RNAs that inhibit gene expression through the 3′untranslated regions (3′UTRs)of their target messenger RNAs.They play crucial roles in numerous biological processes,including cancer progression.Although great efforts have been made,what role miRNAs may play in the early detection and diagnosis of TSCC is not fully under-stood .Recently,our team has performed a series of basic and clinical researches in an attempt to investi-gate the relationships between miRNA expressions and prognosis of patients with TSCC and the mecha-nisms under regulation of TSCC.The results showed that miR-1 95,miR-34a,miR-29b,miR-375 and miR-26a could inhibit TSCC cells progression and development via a sophisticated network of genes.Spe-cifically,the anti-tumor effects of miR-1 95 in TSCC may be partially mediated by its inhibition of Cy-clinD1 and Bcl-2 expression.The expression of miR-34a could inhibit migration and invasion of TSCC cell lines via targeting MMP9 and MMP1 4.The function of miR-29b may be through the miR-29b/Sp1 /PTEN/AKT axis.Overexpression of miR-375 inhibited Sp1 expression by targeting the 3′untranslated re-gion of the Sp1 transcript.MEG3 and miR-26a inhibited TSCC cell proliferation,cycle progression and promoted cell apoptosis and miR-26a could increase the MEG3 expression through reduction of the ex-pression of DNMT3B in TSCC.In light of the role of those miRNAs in diagnosis and prognosis of TSCC, we reported that decreased miR-1 95 and miR-375 expression was associated with poor overall survival rate of the TSCC patients,while miR-34a expression was negatively correlated with cervical lymph node me-tastases.Furthermore,combined low expression levels of miR-26a and MEG3 emerged as an independent prognostic factor for poor clinical outcomes in TSCC patients,suggesting that combined miR-26a and MEG3 expression might prove useful as an independent biomarker of clinical prognosis among TSCC pa-tients.

Development of human embryonic stem cell platforms for human health-safety evaluation / 北京大学学报(医学版)

SUMMARY Thehumanembryonicstemcells(hESCs)serveasaself-renewable,genetically-healthy, pluripotent and single source of all body cells,tissues and organs.Therefore,it is considered as the good standard for all human stem cells by US,Europe and international authorities.In this study,the standard and healthy human mesenchymal progenitors,ligament tissues,cardiomyocytes,keratinocytes,primary neurons,fibroblasts,and salivary serous cells were differentiated from hESCs.The human cellular health-safety of NaF,retinoic acid,5-fluorouracil,dexamethasone,penicillin G,adriamycin,lead ace-tate PbAc,bisphenol A-biglycidyl methacrylate (Bis-GMA)were evaluated selectively on the standar-dized platforms of hESCs,hESCs-derived cardiomyocytes,keratinocytes,primary neurons,and fibro-blasts.The evaluations were compared with those on the currently most adopted cellular platforms.Parti-cularly,the sensitivity difference of PM2.5 toxicity on standardized and healthy hESCs derived fibroblasts, currently adopted immortalized human bronchial epithelial cells Beas-2B and human umbilical vein endo-thelial cells (HUVECs)were evaluated.The results showed that the standardized hESCs cellular plat-forms provided more sensitivity and accuracy for human cellular health-safety evaluation.

Application of three-dimensional tumor mapping technique in diagnosis and treatment of malignant maxillary cancer / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To investigate the application efficacy of three-dimensional tumor mapping technique for diagnosis and treatment of maxillary cancer.</p><p><b>METHODS</b>Seventeen patients (aged from 9 to 74 years with an average age of 44.2 years) diagnosed with maxillary malignant tumors (13 for primary cancer and 4 for recurrent cancer) in Peking University School of Stomatology from December 2012 to October 2014 were reviewed as experimental group, in whom three-dimensional tumor mapping was performed before surgery, and 18 patients underwent traditional surgery in the same period as control group. Three-dimensional tumor imaging was generated with conversion of CT data into DICOM format by a software. Virtual plan of tumor resection and osteotomy was also manipulated according to the three-dimensional position of the tumor. Surgical navigation was used in the operation to confirm the virtual plan. The real position and situation of tumor was evaluated in the operation and compared with the pre-operative design. The frozen section was applied to confirm the margin after tumor resection. All the patients were followed up and the prognosis was evaluated.</p><p><b>RESULTS</b>The real situation of the tumor in the operation matched well with the result of pre-operative tumor mapping and positive margin was detected only in one case. While in the control group, 2 of 18 patients presented with positive margin in the operation. The mean follow-up time was 14.8 months (range from 2.0 to 22.0 months). Local recurrence occurred in 4 cases of experimental group and in 6 cases of controlled group, and all of them were with advanced malignant tumors.</p><p><b>CONCLUSION</b>The three-dimensional tumor mapping technique is a feasible and reliable method for the diagnosis and treatment of maxillary malignant tumor, and use of this technique can significantly improve the clinical outcome.</p>

Classification and reconstruction of 1 107 cases of maxillary defects / 北京大学学报(医学版)

Objective:To investigate the defect types and reconstruction methods of maxillary defects. Methods:The database of 1 107 cases with maxillary defects in Peking University School and Hospital of Stomatology from January 1985 to December 2010 was established. There construction methods were re-viewed. The defect types were classified according to Brown classification system. Results: In the 1 107 cases, 1 104 cases could be classified according to Brown classification system. The most common type was 2a with 559 cases (50. 6%). Among all the 1 107 cases, 349 cases were reconstructed with auto-transplantation, 443 cases with prosthesis, 107 cases untreated, and 208 patients lost to the follow-up. There was a significant growing trend over time for the application of free flaps and a downward trend of prosthesis. The most popular free flaps were fibular flap (88 cases) and radial forearm flap (75 cases) . Rectus abdominis flap and anterolatreal thigh flap were fit for extensive maxillary defects. Conclusion:The most common defect type is 2a. Free flap has become the dominant option for maxillary reconstruc-tion. Free flaps could be selected according to the maxillary defect types.

Expression characteristics of epithelial markers in human embryonic stem cells differentiating into keratinocytes / 北京大学学报(医学版)

Objective:To differentiate human embryonic stem cells ( hESCs ) into keratinocytes ( K-hESCs) and analyse the expression characteristics of biomarkers of K-hESCs.Methods: The hESCs of line H9 were seeded on matrigel in mTeSR1 medium.The hESCs were directly differentiated into kerati-nocytes in epithelial differentiation medium with bone morphogenetic protein 4, retinoic acid and N2 sup-plement.The karyotype of K-hESCs was analyzed, comparing the gene expression differences of K-hESCs with human gingival epithelial cells (HGECs), human immortalized oral epithelial cells (HIOECs) and HaCaT by Real-time PCR.Molecular characteristics of the cell differentiation were observed throughout the process by immunocytochemical techniques.Results:H9-hESCs were successfully differentiated into the cells that exhibited characteristics of keratinocytes in epithelial differentiation medium.The karyotype of K-hESCs was 46, XX; and the keratinocyte gene p63 expression in K-hESCs was significantly lower than that in HaCaT ( P0.05 ) .Conclusion: H9-hESCs could be directly differentiated into K-hESCs.The gene expression of K-hESCs was similar to that of epithelial cells in the early stage of monolayer cells differentiation with high proliferative activity.

Fifty years’ retrospection of systemic study on salivary gland tumors / 北京大学学报(医学版)

SUMMARY Salivary gland tumors are a group of the most common tumors in the oral and maxillofacial region with obvious characteristics of clinical , histopathologic , and therapeutic aspects .During the past 50 years, our research group performed a systemic study on salivary gland tumors including imaging diag-nosis, fine needle aspiration cytology , FT-mid-IR fiber optics spectroscopy , histopathologic features and biological behaviour of the tumors , functional parotid surgery , and 125 I seed implant branchytherapy . More reasonable principles of management for various types of the tumors were put forward based on the histopathologic features of the tumors .The surgical techniques were modified and the postoperative com-plications were reduced obviously .Thus, the quality of life of the patients was improved greatly .

Study on prediction of involvement in facial nerve in the patients with parotid tumors by using facial electroneurography / 北京大学学报(医学版)

Objective:To investigate the possibility of predicting facial nerve involvement in the pa-tients with parotid tumors using facial electroneurography (ENoG).Methods:In the study, 53 patients with primary parotid tumors were included in the study , 28 were benign tumors and 25 were malignant . There was no significant difference of tumor locations and sizes between the two groups . House-Brackmann facial nerve function evaluation was gradeⅠin all the patients who received examination of fa-cial electroneurography , including stimulation strength , amplitude , and latent time bilaterally .The facial electroneurography results in the affected side were compared with the results of contralateral normal side , intraoperative appearance and postoperative histopathological diagnosis .The facial electroneurography results were analyzed by Wilcoxon signed rank test and receiver operator characteristic ( ROC) curve. Results:During the facial electroneurography examination , the mean stimulation strength in the patients with benign parotid tumor was 20.0 mA.There was significant decrease in the amplitude at the affected side compared with the normal side upon posterior auricular stimulation ( P0.05).However, in the patients with malignant parotid tumor , the mean stimulation strength was higher at 24.5 mA.There was signifi-cant decrease in the amplitude or even no response at the affected side compared to the normal side upon posterior auricular stimulation ( P<0 .05 ) .No response was detected in the multiple branches of facial nerve of affected sides in 36 .0%patients upon posterior auricular stimulation .The amplitude of branchesⅢand Ⅳwas significantly lower at the affected side than that at the normal side upon anterior auricular stimulation (P<0.05).The area under the ROC curve for ENoG was 0.884.Conclusion: When the facial nerve was involved by the parotid tumors , the stimulation strength in the electroneurography was larger .There was significant difference in the amplitude and the latent time of the facial nerve between the affected side and the normal side upon the posterior auricular stimulation .The rate of absence of reac-tion wave was higher in the patients with malignant tumors .It was feasible to predict the facial nerve in-volvement by ENoG for the parotid gland tumor patients without clinical appearances of facial paralysis .

Activation of transient receptor potential vanilloid subtype 1 serves as a novel path-way to modulate secretion in submandibular gland / 北京大学学报(医学版)

SUMMARY Our work focused on the studies on the expression and function of transient receptor poten -tial vanilloid subtype 1 ( TRPV1) in the submandibular gland .By using reverse transcription-polymerase chain reaction ( RT-PCR ) , Western blotting , and immunofluorescence , our data demonstrated the expression and distribution characteristics of TRPV 1 in rabbit and human submandibular glands , as well as rat submandibular gland cell line SMG-C6.Furthermore, the possible intracellular signal molecules involved in the TRPV1-modulated saliva secretion were explored .Activation of TRPV1 increased the intracellular Ca2+concentration, upregulated the expression of aquaporin 5 (AQP5), the main transpor-ter that mediate water secretion through transcellular pathway , and led to AQP5 redistribution .Extracel-lular signal-regulated kinase 1/2 ( ERK1/2 ) was involved in the TRPV1-regulated AQP5 content. Besides, TRPV1 activation also modulated the expression , distribution, and function of tight junction protein, and increased paracellular permeability .ERK1/2 and myosin light chain 2 ( MLC2 ) were responsible for the regulation of TRPV1on tight junction properties.Taken together, our work suggested that TRPV1 was a potential target to promote saliva secretion , and activation of TRPV1 might provide a new and safe therapeutic strategy to ameliorate submandibular gland hypofunction .

Study on genetic toxicity of gaseous benzene to mouse bone marrow cells / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the mechanism of genetic toxicity of gaseous benzene to mouse bone marrow cells and to provide an experimental basis for the discovery of early biomarkers among benzene-exposed population.</p><p><b>METHODS</b>Male mice were randomly divided into control group and three benzene-exposed groups (6 mice per group). The control group was exposed to ambient air, and the three benzene-exposed groups were exposed to different concentrations of benzene (400, 800, and 1 600 mg/m(3)) for 15 days, 2 hours per day, in static inhalation chambers. At the end of the 15-day experimental period, the mice were killed. Bone marrow cells were separated from sacrificed mice, and superoxide dismutase (SOD) activity, glutathione peroxidase (GSH-Px) activity, myeloperoxidase (MPO) activity, and malondialdehyde (MDA) content were determined by biochemical methods. DNA damage was evaluated by micronucleus assay and single cell gel electrophoresis (SCGE). The expression of MPO protein was determined by immunocytochemistry.</p><p><b>RESULTS</b>The SOD activities in different dose groups (88.67 ± 13.58, 73.64 ± 4.50, and 67.63 ± 5.42 U/mg prot) were significantly decreased as compared with the control group (119.98±9.42 U/mg prot) (P<0.01). Moreover, the SOD activities in medium- and high-dose groups were significantly lower than that of the low-dose group (P < 0.05). The GSH-Px activities in medium- and high-dose groups (705.07 ± 93.75 and 674.77 ± 86.80 U/mg prot) were significantly decreased as compared with that of the control group (940.25 ± 82.63 U/mg prot) (P < 0.01), and the high-dose group had a significantly lower GSH-Px activity than the low-dose group (674.77 ± 86.80 U/mg prot vs 833.98 ± 130.64 U/mg prot, P < 0.05). The MDA content of low-, medium-, and high-dose groups (22.42±2.67, 22.38±3.02, and 27.66±2.89 nmol/mg prot) were significantly higher than that of the control group (12.35±1.58 nmol/mg prot) (P < 0.01), and MDA content was significantly higher in the high-dose group than in the medium- and low-dose groups (P < 0.05). The micronucleus assay showed that the micronucleus rates in different dose groups (4.67±0.82‰, 5.00±0.89‰, and 5.33±1.03‰) were significantly higher than that of the control group (2.50±0.55‰) (P < 0.01). The SCGE demonstrated that the DNA damage rates of medium- and high-dose groups (22.08% and 25.68%) were significantly higher than that of the control group (7.00%) (P < 0.01), and the DNA damage rate of high-dose group was significantly higher than that of the low-dose group (11.24%) (P < 0.05). MPO activity increased with the dose of benzene in all three benzene-treated groups (16.79±2.16, 19.46±2.28, and 22.53±2.76 U/g prot) and was significantly higher than that of the control group (12.89±0.74 U/g prot) (P < 0.01). The positive rates of MPO protein expression in low-, medium-, and high-dose groups (13.20±2.28%, 30.80±3.35%, and 40.20±1.92%) were significantly higher than that of the control group (6.60±1.14%) (P < 0.01). The MPO activity in high-dose group and the positive rates of MPO protein expression in medium- and high-dose groups were all significantly higher than those of the low-dose group (P < 0.01).</p><p><b>CONCLUSION</b>Gaseous benzene exposure has toxic effect on genetics of mouse bone marrow cells. It leads to chromosome breakage and DNA damage, enhances the activity and protein expression of MPO, and induces lipid peroxidation. Lipid peroxidation damage is a potential mechanism by which gaseous benzene exerts toxic effect on mouse bone marrow cells.</p>

Endoscopy-assisted sialolithectomy for the calculus of the Stensen's duct / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the clinical effects of endoscopy-assisted sialolithectomy for the calculus in the Stensen's duct.</p><p><b>METHODS</b>From August 2005 to July 2013, 67 consecutive patients with calculus (or foreign bodies) in the Stensen's duct underwent explorative and interventional endoscopy in our hospital. The stones (or foreign bodies) were removed by endoscopy-assisted technique. After operation, the patients were followed-up periodically, and treatment effects were analyzed.</p><p><b>RESULTS</b>Among the 67 patients, the stones (or foreign bodies) were completely removed in 58 cases, and almost completely removed in 3 cases, with a success rate of 87% (58/67). Among the 61 stone-removed cases, treatment options included direct removal with aid of basket or forceps (24 cases), basket entrapment and opening-up of the ostium (21 cases), basket entrapment and mucosal incision near the ostium (8 cases), open removal via buccal incision (2 cases) and open removal via pre-auricular flap (6 cases). During the 6-90 months' follow-up of the 61 cases, 48 cases were asymptomatic, 7 had mild symptoms, 3 developed ductal obturation, 1 had numbness in the parotid region, and the remaining 2 were missed.</p><p><b>CONCLUSIONS</b>Endoscopy-assisted sialolithectomy is a safe and effective gland-preservation technique for the patients with parotid gland calculus.</p>