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Objective Formaldehyde (FA) is known to induce lung injury, but the underlying molecular mechanism remains largely unclear. CDR1as is an important member of the circular RNAs (circRNAs) family and functions as miRNA sponges with gene-regulatory potential. Our earlier circRNA microarray data showed CDR1as was highly expressed in lung tissue exposed to FA. However, the mechanism of circRNA-CDR1as mediates the FA-exposed lung injury is still unclear. This study aimed to explore the role of CDR1as in lung injury. Materials and methods In this study, FA was inhaled at doses of 0.5, 2.46, and 5 mg/m3, respectively. After exposure 8 weeks, lung histopathological examination, lung injury score, and IL-1β in bronchoalveolar lavage fluid (BALF) were determined. The expressions of CDR1as, rno-miR-7b and Atg7 were detected and the potential interaction of circRNA/miRNA/mRNA was predicted by bioinformatics analysis, including drawing circRNA/miRNA/mRNA interaction network, GO and KEGG analysis. Results Our results indicated FA inhalation upregulated the expression of CDR1as in lung tissues in a dose-dependent manner while the expression of rno-miR-7b decreased and Atg7 increased. Moreover, the alteration of CDR1as was positively correlated with lung injury. Discussion and conclusions CircRNA/miRNA/mRNA prediction further explained the possible effect mechanisms of CDR1as. These data implicated that CDR1as might be a critical regulator involved in lung injury induced by FA.

BACKGROUND: Beclin-1 is an autophagy gene and higher levels suggest mammalian testicular damage. Our study aims at exploring the role of Beclin-1 in non-obstructive azoospermia (NOA) patients and clarifying the predictive value of Beclin-1for sperm retrieval in microdissection testicular sperm extraction (micro-TESE). METHODS: In the present study, 62 NOA patients were finally recruited. Serum hormone including luteinizing hormone (LH), follicle-stimulating hormone (FSH), estradiol II (E2), testosterone (T) and prolactin (PRL), as well as testicular volume were measured. Testicular histopathology was diagnosed by two independent pathologists. The expression of Beclin-1 was detected by real-time PCR in testicular tissue. RESULTS: Our study illustrated that Beclin-1 was differently expressed in three pathological types of NOA. Compared with hypospermatogenesis (HS, P=0.002) or maturation arrest (MA, P=0.049), Beclin-1 showed significantly up-regulated in Sertoli cell-only syndrome (SCOS) group. Moreover, Beclin-1 expression was obviously positive related with serum LH (rho =0.269, P=0.036), meanwhile significantly negative correlation with testicular volume (rho =−0.370, P=0.003), serum T (rho =−0.326, P=0.010), Johnsen score (rho =−0.318, P=0.012), and pathologic type (rho =−0.452, P

ImportanceThe potential effects of long-term occupational exposure to formaldehyde (FA) on human semen quality is not clear.ObjectiveTo assess whether long-term occupational exposure to FA is associated with semen quality.Design, Setting, and ParticipantsThis population-based cohort study was conducted from June 1 to June 30, 2021, in Xi’an, China. Participants were adults aged 23 to 40 years who had lived in the study area for 24 months or longer. Data analysis was performed from September 1 to October 1, 2021.ExposuresLong-term occupational exposure to FA was measured using a formaldehyde detector, and the FA exposure index (FEI) was calculated as follows: FEI = final concentration of FA (mg/m3) × work time during a workday (hour) × cumulative workdays (year).Main Outcomes and MeasuresSemen samples were collected by masturbation after 3 to 7 days of abstinence and were then assessed by the computer-automated semen analysis system, Baso-Papanicolaou staining, and sperm-chromatin structure assay.ResultsA total of 205 men (mean [SD] age, 29.49 [3.64] years), with 124 individuals in the FA exposure group (mean [SD] FEI, 73.72 [54.86]) and 81 age-matched controls, were included in the final analysis. Long-term personal occupational exposure to FA was significantly associated with poor semen quality. Specifically, a 1-unit increase in FEI was associated with a change of −0.99% (95% CI, −1.00% to −0.98%) in total sperm motility, −0.99% (95% CI, −0.99% to −0.97%) in progressive sperm motility, −0.05% (95% CI, −0.08% to −0.02%) in curvilinear velocity, −0.07% (95% CI, −0.10% to −0.04%) in straight line velocity, −0.07% (95% CI, −0.10% to −0.04%) in time-average velocity, −0.98% (95% CI, −0.99% to −0.93%) in normal sperm morphology, −0.24% (95% CI, −0.35% to −0.11%) in seminal neutral glucosidase, −0.61% (95% CI, −0.66% to −0.56%) in seminal plasma zinc, 0.52% (95% CI, 0.15% to 1.02%) in beat cross frequency, and 0.10% (95% CI, 0.06% to 0.14%) in the DNA fragmentation index. These associations remained significant after adjusting for confounding factors. Furthermore, subgroup analysis found that high levels of oxidative stress might promote the associations between FA exposure and semen quality.Conclusions and RelevanceThis study found an association between long-term occupational exposure to FA and semen quality. This deterioration was dose and time dependent and might be induced by oxidative stress.

STUDY QUESTION Are there temporal trends of sperm concentration (SC) and total sperm count (TSC) in Chinese healthy males from 1981 to 2019? SUMMARY ANSWER Our result indicated a temporal decrease in SC and TSC among 327 373 healthy Chinese men in the recent four decades. WHAT IS KNOWN ALREADY A review of 61 papers reported a temporal decline in SC and TSC from 1938 to 1990. This trend was later confirmed by a systematic review of 185 published papers from 1981 to 2013. However, the majority of the included individuals were from western countries. In China, whether SC and TSC have declined remains controversial. STUDY DESIGN, SIZE, DURATION This systematic review of published articles used data extracted from Pubmed, Science Direct, Embase, China-National-Knowledge-Infrastructure (CNKI) and Wanfang Data to assess changes in SC and TSC in China from 1981 to 2019. PARTICIPANTS/MATERIALS, SETTING, METHODS A total of 111 studies including 327 373 individuals who provided semen samples from 1981 to 2019 were extracted for the present analysis. Study selection and data extraction were performed by two independent researchers. The trends in SC and TSC were analysed using liner-regression and meta-regression before and after adjusting for potential covariates. Moreover, subgroups, categorised based on geographic region, fertility status or recruitment source, were also analysed. MAIN RESULTS AND THE ROLE OF CHANCE SC declined significantly (slope liner-regression = −0.748 million/ml/year; P = 0.005; slope meta-regression = −0.824 million/ml/year; P LIMITATIONS, REASONS FOR CAUTION The validity of the meta-analysis results was limited mainly by the quality of the included studies. Additionally, our study spanned many decades and the recommended criteria for some semen parameter assessments have significantly changed, which may bring about some unavoidable bias. Moreover, the data remain insufficient especially in some provinces of China. WIDER IMPLICATIONS OF THE FINDINGS The present study is the first study to report significant decreases in SC and TSC in 327 373 healthy Chinese men between 1981 and 2019, indicating a serious reproductive health warning. Further studies on the causes of the declines are urgently needed. STUDY FUNDING/COMPETING INTEREST(S) D.Z. is supported by the National Natural Science Funding of China, Natural Science Funding of Shaanxi Province, Science Funding of Health Department, Shaanxi Province, Fundamental Research Funds for the Central University and the Project of Independent Innovative Experiment for Postgraduates in Medicine in Xi’an Jiaotong University. The authors have no conflicts of interests to declare. TRIAL REGISTRATION NUMBER N/A

Objective: Formaldehyde, a ubiquitous environmental contaminant, has long been suspected of causing male reproductive injury, but the underlying molecular mechanism remains largely unknown. SPO11 i...

Background. Pericytes play an important role in forming functional blood vessels and establishing stable and effective microcirculation, which is crucial for vascular tissue engineering. The slow ex vivo expansion rate, limited proliferative capacity, and variability of tissue-specific phenotypes would hinder experimental studies and clinical translation of primary pericytes. In this study, the angiogenic and pericyte functions of stem cells from human exfoliated deciduous teeth (SHEDs) and postnatal human dental pulp stem cells (DPSCs) were investigated. Methods. Osteogenic and adipogenic induction assays were performed to evaluate the mesenchymal potential of SHEDs, DPSCs, and pericytes. An in vitro Matrigel angiogenesis assay was conducted to reveal the ability of SHEDs, DPSCs, and pericytes to stabilize vascular-like structures. Quantitative real-time polymerase chain reaction (RT-qPCR) was performed to evaluate mRNA expression. Flow cytometry, western blotting, and immunostaining were used to assess the protein expression. Wound healing and transwell assays were performed to evaluate the migration ability of SHEDs, DPSCs, and pericytes. Results. The osteogenic and adipogenic induction assays showed that SHEDs, DPSCs, and pericytes exhibited similar stem cell characteristics. The mRNA expression levels of PDGFR-β, α-SMA, NG2, and DEMSIN in SHEDs and DPSCs cultured in EC medium were significantly higher than those in the control groups on day 7 ( P < 0.05 ), but significantly higher than those in the pericytes group on day 14 ( P < 0.05 ). Flow cytometry showed that high proportions of SHEDs and DPSCs were positive for various pericyte markers on day 7. The DPSCs, SHEDs, and pericytes displayed strong migration ability; however, there was no significant difference among the groups ( P > 0.05 ). Conclusion. The SHEDs and DPSCs display a profile similar to that of pericytes. Our study lays a solid theoretical foundation for the clinical use of dental pulp stem cells as a potential candidate to replace pericytes.

Although circular RNAs (circRNAs) can function as microRNAs (miRNAs) sponges to participate in spermatogenesis, little is known about the functions of circRNAs in testis exposed to formaldehyde. In this study, twenty-four male SD rats (6–8 weeks) were randomly assigned to four groups, including a control group, 0.5, 2.46, and 5 mg/m3 formaldehyde exposure groups, inhaling formaldehyde for eight consecutive weeks. The RT-qPCR was used to detect the expression of rno_circRNA_016194; the testicular injuries were observed by testicular histopathology. Our study illustrated up-regulated rno_circRNA_016194 was dose-dependent with formaldehyde. Simultaneously, the testicular histopathology showed an obvious damages in the 2.46 and 5 mg/m3 formaldehyde exposure rats. Combined with bioinformatics analysis, the rno-miR-449a-5p was predicted and verified that its expression decreased in the testis exposed to formaldehyde. Meanwhile, the testicular morphometry changes were contrary to the expression of rno_circRNA_016194 and consistent with rno-miR-449a-5p. Moreover, bioinformatics analysis also prompted the potential downstream target gene for rno_circRNA_016194/rno-miR-449a-5p was Atg4b, and Atg4b expression was up-regulated in rats exposed to formaldehyde verifying by Western blot. Collectively, the rno_circRNA_016194 might be involved in formaldehyde-induced male reproductive toxicity and become potential therapeutic targets for male occupational exposure to formaldehyde.

Numerous studies concentrate on the association between X-ray repair cross-complementing group 1 (XRCC1) gene polymorphism and male infertility; however, the results remain inconclusive and inconsistent. Hence, this meta-analysis was conducted to get a precise estimation of the correlation. PubMed, Web of Science, Embase, Scopus and China National Knowledge Infrastructure (CNKI) databases were searched to identify the all relevant studies before 3 May 2020. Summary odds ratios (ORs) and 95% confidence intervals (95% CIs) were used to assess the strength of the association. Finally, six studies with 1,886 cases and 1,212 controls were included in our study. The result indicated that XRCC1 Arg399Gln polymorphism was significantly associated with male infertility under allelic model (A-allele vs. G-allele: OR = 1.183, p = .003), heterozygote genetic model (AA vs. GA: OR = 1.256, p = .027), recessive genetic model (AA vs. GG + GA: OR = 1.279, p = .012) and dominant genetic model (AA + GA vs. GG: OR = 1.218, p = .026). In addition, in Asian subgroup, statistic correlation remained significant in allelic model (A-allele vs. G-allele: OR = 1.145, p = .025) with rare heterogeneity (I2 = 0%). In summary, our meta-analysis suggested that XRCC1 Arg399Gln polymorphism was significantly associated with male infertility and the A-allele might be a risk factor for this disease, especially in Asians.

Background: Recent studies reported a decrease of sperm count around the world, however, little data from China was included. In China, declines in sperm quality remain controversial. Therefore, this study attempted to explore the temporal trends in sperm quality of Chinese healthy males from 1981 to 2019. Methods: Based on the protocol provided by Levine et al, data extracted from Pubmed, Science Director, Embase, China National Knowledge Infrastructure (CNKI) and Wanfang Data were collected to assess changes of sperm concentration (SC) and total sperm count (TSC) in recent decades using simple liner regression and meta-regression before and after adjusting for potential covariates including fertility group, region group, mean age, abstinence time, sperm collection and counting methods and whether individual provides more than one sample selection of population. Moreover, subgroups, categorizing based on geographic region or fertility status, were also conducted. Findings: A total of 102 studies with 271,545 individuals who provided semen samples from 1981 to 2019 were finally extracted for the present meta-regression analysis. SC declined significantly, on average, 0.43% per year with an overall decline of 16.3% between 1981 and 2019 (slope in unadjusted simple regression models -0.848 million/ml/year; 95% CI: -1.392 to -0.304; P = 0.002; slope in adjusted meta-regression models = -0.854; −1.452 to -0.630; P < 0.001). Trends for TSC was similar to that for SC with 0.89% per year and 33.08% overall decline from 1981 to 2019 (slope in unadjusted simple regression models = -2.063 million/year; 95% CI: -3.840 to -0.287, P = 0.023; slope in adjusted meta-regression models = -2.536; -4.052 to -1.022; P = 0.001). In subgroup meta-regression analysis, the slopes in model could be modified by fertility and region group (PSC for interaction = 0.031 and PTSC for interaction = 0.006). Fertility males in northern China had continuous declines in both SC (slope= -2.393; -3.964 to -0.822; P = 0.006) and TSC (slope= -9.675; -16.295 to -3.054; P = 0.010). Similarity, unselected group (unknown fertility males) in northern China also showed significant decreases in both SC (slope= -0.866; -1.403 to -0.329; P = 0.002) and TSC (slope= -1.806; -3.744 to -0.131; P = 0.047). Meanwhile, in southern China, only SC had significant down trends in fertility individuals (slope= -0.997; -1.736 to -0.258; P = 0.008). No changes in SC or TSC were seen in other groups separately. Results changed minimally in multiple sensitivity analyses, and there was no statistical support for the use of a nonlinear model. Interpretation: The present study was the first study to assess semen quality among 271,545 Chinese general healthy men in the recent 4 decades and our result indicated a serious reproductive health warning that sperm quality in general healthy Chinese men decreases between 1981 and 2019. Further studies on causes of the decreases are urgently needed. Funding Statement: This research was financially supported by National Natural Science Funding of China (to DZ) and Natural Science Funding of Shaanxi Province (to DZ). Declaration of Interests: All authors declare no conflict of interest.

Mesenchymal stem cells (MSCs) have become a recent focus of experimental and clinical research regarding myocardial regeneration. However, the therapeutic potential of these cells is limited by poor survival. Prostaglandin E1 (PGE1) is known to have anti‑inflammatory and anti‑apoptotic effects on the myocardium. The aim of the present study was to determine whether PGE1 could protect MSCs against serum deprivation (SD)‑induced apoptosis. An SD model was used to induce apoptosis in MSCs in vitro. Apoptotic morphological changes were detected by Hoechst 33258 fluorescent nuclear staining; and Annexin V‑fluorescein isothiocyanate/propidium iodide (PI) double staining and flow cytometry was used to quantify the rate of apoptosis. Western blot analysis was used to detect the expression levels of the apoptosis‑associated proteins Bcl‑2, Bax and caspase‑3. The results of the present study demonstrated that SD induced apoptosis of MSCs, and that treatment with PGE1 attenuated the morphological changes characteristic of apoptosis. Annexin V/PI staining showed that the rate of apoptosis gradually increased with the duration of ischemia. Furthermore, treatment with PGE1 significantly reduced SD‑induced apoptosis, decreased the protein expression levels of Bax and caspase‑3, and increased the expression levels of Bcl‑2. These data suggest that PGE1 is able to influence the survival of MSCs under certain conditions. These results may aid in improving the therapeutic efficacy of MSC transplantation used to treat chronic ischemic heart disease.

Superparamagnetic iron oxide (SPIO) nanoparticles generate superparamagnetism, thereby resulting in an inhomogeneous local magnetic field, which shortens the T2 value on magnetic resonance imaging (MRI). The purpose of the present study was to use MRI to track bone marrow mesenchymal stem cells (BMSCs) labeled with SPIO in a rat model of myocardial infarction. The BMSCs were isolated from rats and labeled with SPIO. The anterior descending branch of the coronary artery was ligated under anesthesia. Two weeks later, the rats received, at random, 5 x 10(7) SPIO-labeled BMSCs, 5 x 10(7) unlabeled BMSCs or a vehicle (100 µl phosphate-buffered saline) via direct injection into the ischemic area (20 animals/group). MRI was used to track the SPIO‑labeled BMSCs and the rats were then sacrificed to verify the presence of BMSCs using immunohistochemistry with an anti-CD90 antibody. The procedure labeled 99% of the BMSCs with SPIO, which exhibited low-intensity signals on T2 and T2* MRI imaging. At 24 h post-BMSC transplantation, low-intensity MRI signals were detected on the T2 and T2* sequences at the infarction margins. After 3 weeks following transplantation, low-intensity signals started to appear within the infarcted area; however, the signal intensity subsequently decreased and became indistinct. Immunohistochemistry revealed that the SPIO-labeled BMSCs migrated from the margin into the infarcted region. In conclusion, the BMSCs were readily labeled with SPIO and in vivo and MRI tracking demonstrated that the SPIO-labeled BMSCs established and grew in the infarcted myocardium.

Mesenchymal stem cells (MSCs) have become a recent focus of experimental and clinical research regarding myocardial regeneration. However, the therapeutic potential of these cells is limited by poor survival. Prostaglandin E1 (PGE1) is known to have anti-inflammatory and anti-apoptotic effects on the myocardium. The aim of the present study was to determine whether PGE1 could protect MSCs against serum deprivation (SD)-induced apoptosis. An SD model was used to induce apoptosis in MSCs in vitro. Apoptotic morphological changes were detected by Hoechst 33258 fluorescent nuclear staining; and Annexin V-fluorescein isothiocyanate/propidium iodide (PI) double staining and flow cytometry was used to quantify the rate of apoptosis. Western blot analysis was used to detect the expression levels of the apoptosis-associated proteins Bcl-2, Bax and caspase-3. The results of the present study demonstrated that SD induced apoptosis of MSCs, and that treatment with PGE1 attenuated the morphological changes characteristic of apoptosis. Annexin V/PI staining showed that the rate of apoptosis gradually increased with the duration of ischemia. Furthermore, treatment with PGE1 significantly reduced SD-induced apoptosis, decreased the protein expression levels of Bax and caspase-3, and increased the expression levels of Bcl-2. These data suggest that PGE1 is able to influence the survival of MSCs under certain conditions. These results may aid in improving the therapeutic efficacy of MSC transplantation used to treat chronic ischemic heart disease.

The prevalence of malocclusion in modern population is higher than that in the excavated samples from the ancient times. Presently, the prevalence of juvenile malocclusion in the early stage of permanent teeth is as high as 72.92% in China. This study aimed to observe and evaluate the prevalence and severity of malocclusions in a sample of Xia Dynasty in China, and to compare these findings with the modern Chinese population.The material consisted of 38 male and 18 female protohistoric skulls of Xia Dynasty 4000 years ago. Of 86 dental arches, 29 cases had the jaw relationships. Tooth crowding, diastema, individual tooth malposition and malocclusion were studied.Of the samples, 23.3% showed tooth alignment problems including crowding (8.1%), diastema (9.3%), and individual tooth malposition (5.8%). The prevalence of malocclusion was 27.6%, mainly presented as Angle Class I.It is indicated that over thousands of years from Neolithic Age (6000 - 7000 years ago) to Xia Dynasty (4000 years ago), the prevalence of malocclusion did not change significantly. The prevalence of malocclusion of Xia Dynasty samples was much lower than that of modern population.

To investigate the factors which influence the changes of lower third molars' angulation and space/crown width ratio by orthodontic treatment.Pretreatment and posttreatment panoramic radiographs of 120 orthodontically treated cases were taken. The lower third molars' angulation and space/crown width ratio were examined and the relative factors on changes were analyzed.(1)The changes of the lower third molars' angulation and space/crown width ratio after orthodontic treatment were quite different among the cases. (2)The factors which influenced these changes mainly included extraction, mandibular plane angle, angulation and space/crown width ratio of lower third molar before orthodontic treatment. (3) Extraction was the most significantly variable associated with lower third molars' upright (angulation30 degree) after orthodontic treatment.Orthodontic extraction is helpful to upright the lower third molars and to increase the space for third molars; and the pre-treatment lower third molars' angulation and space/crown width ratio are important variables for the changes after treatment; cases with lower mandibular plane angle are apt to greater possibility for the lower third molars' upright.

To compare between MLO-Y4 osteocyte and osteoblast to support osteoclast formation in co-culture system.MLO-Y4 cells and murine osteoblast cells were co-cultured with bone marrow cells with or without vitamin D₃ presence.Bone marrow cells were as control group. Tartrat resistant acid phosphatase (TRAP)+ giant cells with three or more nuclei were counted and compared under a microscope at day 9.In the absence of vitamin D₃, (1963.3 ± 93.1)/plate osteoclasts were observed when MLO-Y4 cells co-cultured with bone marrow cells in 24-well plate.While only (12.7 ± 5.5)/plate osteoclasts were found in the osteoblast group, and (6.0 ± 1.0)/plate in control group. The statistical difference occurs for any two groups (P0.05). Vitamin D₃ could significantly increase osteoclast formation in the three groups.Osteocytes could induce osteoclastogenesis without the presence of vitamin D₃ and vitamin D₃ could enhance the induction effects of MLO-Y4 and osteoblast cells.

To study the relation of tumor interstitial T lymphocyte subset activity to the clinical staging of non-small-cell lung cancer (NSCLC) and the immune response.Immunohistochemical staining for CD4(+), CD8(+) and CD4(+)CD25(+) Foxp3(+) (regulatory T cells, Treg) T cells was performed on paraffin-embedded tissues from 60 NSCLC cases.Compared to stage I/II NSCLC patients, patients in stage III/IV showed a significant decrease in the percentage of CD4(+) and CD4(+)/CD8(+) T cells (P0.05) and an increase in CD8(+) and CD4(+)CD25(+) Foxp3(+) T cells (P0.05). Treg cells were enriched in the tumor tissue as compared with those in the adjacent tissues.The proportion of CD4(+)CD25(+) Foxp3(+) Treg cells is positively correlated to the clinical staging of NSCLC, in which T cell-mediated immune response is suppressed.

To investigate the expression of tumor stem cell marker CD133 and endothelin-converting enzymes (ECE) in non-small cell lung carcinoma (NSCLC) and their association with NSCLC lymphoid metastasis.CD133 and ECE expressions was detected immunohistochemically in the specimens from 77 patients with NSCLC, and the association of CD133 and ECE expressions with the tumor size, histological type, differentiation, lymphoid metastasis, and prognosis of NSCLC was analyzed.The positive expression rate of CD133 and ECE was 51.9% (40/77) and 45.5% (35/77) in these specimens, respectively. Both CD133 and ECE expressions were associated positively with lymphoid metastasis (r=0.246 and 0.339, P0.05), and inversely with the survival time of the patients (P0.05). CD133 and ECE expressions were not related to tumor size, histological type, and differentiation of the tumor (P0.05). CD133 expression was associated positively with ECE expression in NSCLC (r=0.249, P0.05).CD133 and ECE expressions are associated with lymphoid metastasis and prognosis of NSCLC, and their overexpression often suggests unfavorable prognosis of NSCLC.

The intensity of lymphatic metastasis consists of lymph node metastasis number (LMN) and lymph node metastasis ratio (LMR). LMR is the ratio of positive nodes to dissected nodes. LMN and LMR are 2 important prognostic factors of esophageal cancer, and are adopted in tumor staging. This study was to assess the lymphatic metastasis intensity of thoracic esophageal squamous cell carcinoma (ESCC), and explore the influential factors and lymphadenectomy pattern.A total of 120 patients with ESCC had been operated in the Second Affiliated Hospital of Sun Yat-sen University from 1998 to 2000. The lymph nodes were dissected according to the mapping scheme of the American Thoracic Society (ATS) modified by Casson et al.A total of 2 631 lymph nodes were dissected with an average of 22 lymph nodes in each case. The cervical LMR was significantly higher in the upper thoracic ESCC than in the middle and lower thoracic ESCC (20.9% vs. 12.9% and 6.8%, P0.05). The left gastric LMR was significantly higher in the lower thoracic ESCC than in the middle and upper thoracic ESCC (37.5% vs. 17.5% and 7.1%, P0.05). Subcarinal metastatic lymph nodes were often found in the middle thoracic ESCC. T stage, histological differentiation, and circum wall involvement degree were correlated to lymphatic metastasis intensity (P0.05); the length of esophageal lesion had no correlation to lymphatic metastasis intensity (P0.05). The survival time of the patients received the right thoracic esophagectomy with 3-field lymphadenectomy (3-FL) was significantly longer than that of the patients received the left thoracic esophagectomy with 2-FL (P0.05).During the operation on ESCC, the regions with high lymphatic metastasis intensity should be dissected. T stage, histological differentiation, and circum wall involvement degree are important influential factors of lymphatic metastasis intensity. The right thoracic esophagectomy with 3-FL is superior to the left thoracic esophagectomy with 2-FL.

To study the expression of osteoprotegerin(OPG) and receptor activator nuclear factor kappa B ligand(RANKL) at protein level in human periodontal ligament cells (HPDLCs), and the effect of 1alpha,25(OH)(2) vitamin D(3) [1,25(OH)(2)vitD(3)] on the secretion of OPG protein in vitro.HPDLCs were harvested in vitro by sequential digestion with trypsin and collagenase. The expression of RANKL in HPDLCs at protein level was tested by immunocyto-chemistry. Enzyme-linked immunoadsordent assay (ELISA) was used to detect the OPG protein which was secreted into the culture medium by HPDLCs cultured with and without 10(-8) mol/L 1alpha,25 (OH)(2)vitD(3) on the 0, 2nd, 4th, and 6th days, respectively.RANKL protein was detected on the membrane and plasma of HPDLCs, and OPG protein was secreted in the culture medium. The secretion of OPG protein was down-regulated by 10(-8) mol/L 1alpha,25 (OH)(2)vitD(3).HPDLCs have the bone metabolism system of OPG/RANKL, which works during the process of 1alpha,25 (OH)(2)vitD(3) inducing HPDLCs. The conclusion has laid the groundwork for the study on bone remodelling mechanisms of HPDLCs.