[Mediating effect of self-efficacy on self-management ability and self-management behavior in patients with type 2 diabetes mellitus].

OBJECTIVE: To investigate the mechanism of self-efficacy between self-management ability and self-management behavior and its differences among patients with different disease courses through mediation tests. METHODS: In the study, 489 patients with type 2 diabetes who attended the endocrinology departments of four hospitals in Shanxi Province and Inner Mongolia Autonomous Region from July to September 2022 were enrolled as the study population. They were investigated by General Information Questionnaire, Diabetes Self-Management Scale, Chinese version of Diabetes Empowerment Simplified Scale, and Diabetes Self-Efficacy Scale. Mediation analyses were performed using the linear regression model, Sobel test, and Bootstrap test in the software Stata version 15.0 and divided the patients into different disease course groups for subgroup analysis according to whether the disease course was > 5 years. RESULTS: In this study, the score of self-management behavior in the patients with type 2 diabetes was 6.16±1.41, the score of self-management ability was 3.99±0.74, and the score of self-efficacy was 7.05±1.90. The results of the study showed that self-efficacy was positively correlated with self-management ability (r=0.33) as well as self-management behavior (r=0.47) in the patients with type 2 diabetes (P < 0.01). The mediating effect of self-efficacy accounted for 38.28% of the total effect of self-management ability on self-management behaviors and was higher in the behaviors of blood glucose monitoring (43.45%) and diet control (52.63%). The mediating effect of self-efficacy accounted for approximately 40.99% of the total effect for the patients with disease course ≤ 5 years, while for the patients with disease course > 5 years, the mediating effect accounted for 39.20% of the total effect. CONCLUSION: Self-efficacy enhanced the effect of self-management ability on the behavior of the patients with type 2 diabetes, and this positive effect was more significant for the patients with shorter disease course. Targeted health education should be carried out to enhance patients' self-efficacy and self-management ability according to their disease characteristics, to stimulate their inner action, to promote the development of their self-management behaviors, and to form a more stable and long-term mechanism for disease management.

[Comparison of application effects of colonoscopy, fecal immunochemical test and a novel risk-adapted screening approach in colorectal cancer screening in Xuzhou population].

Objective: To compare the application effect of the colonoscopy, fecal immunochemical test (FIT) and novel risk-adapted screening approach in colorectal cancer screening in Xuzhou population. Methods: From May 2018 to April 2019, 4 280 subjects aged 50-74 were recruited from Gulou district, Yunlong district and Quanshan district of Xuzhou. They were randomly assigned to the colonoscopy group (n=863), FIT group (n=1 723) and novel risk-adapted screening approach group (n=1 694) according to the ratio of 1∶2∶2. For the novel risk-adapted screening approach group, after the risk assessment, high-risk subjects were invited to undergo colonoscopy and low-risk subjects were invited to undergo FIT examination. All FIT positive subjects were invited to undergo colonoscopy. Colonoscopy participation rate [(the number of colonoscopies completed/the number of colonoscopies invited to participate)×100%], detection rate of colorectal lesions [(the number of diagnosed patients/the number of colonoscopies completed)×100%], colonoscopy resource load (the number of colonoscopies completed/the number of diagnosed advanced tumors) and FIT resource load in each group were calculated and compared. Results: The age of all subjects was (61±6) years old, including 1 816 males (42.43%). There was no statistically significant difference in the socio-demographic characteristics of the subjects in different screening groups. The colonoscopy participation rate was 22.60% (195/863) in the colonoscopy group, 57.04% (77/135) in the FIT group, and 33.94% (149/439) in the novel risk-adapted screening approach group, respectively. The colonoscopy participation rate was higher in the FIT group than in the colonoscopy group and the novel risk-adapted screening approach group (P<0.001). The colonoscopy participation rate of novel risk-adapted screening group was significantly higher than the colonoscopy group (P<0.001). The detection rates of advanced tumors were 6.67% (13/195), 9.09% (7/77) and 8.72% (13/149), respectively, and the difference was not statistically significant (P>0.05). The colonoscopy resource load (95%CI) was 15 (13-17) in the colonoscopy group, 11 (9-14) in the FIT group and 11 (10-13) in the novel risk-adapted screening approach group, respectively. Among them, the colonoscopy resource load of high-risk individuals in the novel risk-adapted screening approach group was 12 (9-15). FIT resource loads (95%CI) were 207 (196-218) and 88 (83-94) in the FIT group and the novel risk-adapted screening approach group. Conclusion: The combined application of risk-adapted screening approach and FIT may have a good application effect in colorectal cancer screening.

[Primary study on the relationship between high-risk HPV infection and vaginal cervical microbiota].

Objective: To understand characteristics of vaginal cervical microbiota in high-risk HPV (hrHPV) infected women and to uncover the relationship between hrHPV infection and vaginal cervical microbiota. Methods: All participants were randomly selected from Peking University First Hospital from September to October of 2017, including 5 subjects of control group, 5 cases of HPV16/18 group, 5 cases of other hrHPV infected group and 3 cases of cervical squamous carcinoma group. All subjects were required to fill in a questionnaire, and cervical and vaginal discharges were separately collected for microscopic examination and new generation sequencing targeting the variable region (V3-V4) of bacterial 16S rRNA gene. Results: Vaginal microbiota analysis: (1) 6 major phylum were found in vaginal microbiota:Firmicutes, Bacteroidetes, Fusobacteria, Actinobacteria, Tenericutes and Proteobacteria. Firmicutes contributed to the majority of normal vaginal flora, Bacteroidetes and Fusobacteria increased in hrHPV infected ones, while Fusobacteria showed significant difference in cervical carcinoma group. (2) Lactobacillus occupied most of normal vaginal flora while genus like Gardnella, Prevotella, Atopobium, Megasphaera and Sneathia increased in hrHPV infected subjects, Sneathia showed significant difference in cervical carcinoma group. (3) No significant difference had been calculated in Alpha diversity of four groups (P=0.073) . Cervical microbiota analysis: (1) Microbial diversity of cervical microbiota was higher than that of vaginal microbiota. (2) Significant difference had been found in Alpha diversity of four groups (P=0.046) . (3) Proteobacteria in normal cervical flora was much more than that in vagina, and Proteobacteria increased significantly in hrHPV infected cervical discharge. (3) Chlamydia increased significantly in cervical carcinoma group. Conclusions: The diversity of cervical microbiota is higher than that of vaginal microbiota. Change in cervical microbiota is more obvious than that of vagina in hrHPV infected subjects. Fusobacteria-Sneathia and Chlamydia significantly increase in cervical carcinoma group. Proteobacteria might relate to hrHPV infection.

ß-asarone from Acorus gramineus alleviates depression by modulating MKP-1.

In this study, we investigated the antidepressant effects of hippocampal neuron administration of ß-asarone, a selective mitogen-activated protein kinase phosphatase-1 inhibitor, in a rat model of depression. Our previous studies showed that the extracellular signal-regulated kinase signaling pathway and brain-derived neurotrophic factor expression, which is regulated by extracellular signal-regulated kinase, are key links in the biological mechanism of depression. Mitogen-activated protein kinase phosphatase-1 (MKP-1) is a negative regulatory protein of extracellular signal-regulated kinase signaling pathways. In this study, we explored the regulation of MKP-1 by ß-asarone in producing an antidepressant effect.

Prevention of hypoxic pulmonary hypertension by hypoxia-inducible expression of p27 in pulmonary artery smooth muscle cells.

Hypoxia-induced proliferation of pulmonary artery smooth muscle cells (SMCs) is important in the development of hypoxic pulmonary hypertension (HPH). We constructed a lentivirial vector containing a smooth muscle-specific promoter and six copies of hypoxia response element to co-drive the expression of p27, the key cyclin-dependent kinase inhibitor that blocks the G1 to S phase transition in cell cycle progression, in pulmonary artery SMCs in hypoxia. Then in vivo we examined the prevention effects of the vector on HPH in mice and in vitro the specificity on the hypoxia-inducible expression of p27 in pulmonary artery SMCs. Hypobaric hypoxia for 4 weeks resulted in significant increases in the right ventricular systolic pressure, the ratio of right ventricle to left ventricle plus septal weight and the muscularization of pulmonary vessels in mice. Administration of the vector before hypoxia significantly prevented the effects of hypoxia. In vitro, the vector exhibited hypoxic inducibility and relatively specific expression in pulmonary artery SMCs, inhibited the hypoxia-induced proliferation of pulmonary artery SMCs and arrested more cells at G0/G1 phase. These results demonstrate that the hypoxia-inducible p27 expression prevents the development of HPH in mice.

Therapeutic drug monitoring and receiver operating characteristic curve prediction may reduce the development of linezolid-associated thrombocytopenia in critically ill patients.

To investigate the risk factors associated with the development of thrombocytopenia, and define the thresholds of efficacy and safety in critically ill patients who received linezolid therapy. A retrospective study was performed in critically ill patients treated with linezolid. Risk factors associated with thrombocytopenia were identified via medical records and trough levels (C(min)) measured during linezolid treatment. By establishing a logistic model, the risks were predicted by the receiver operating characteristic (ROC) curve and the thresholds of efficacy and safety were identified in the patients. Logistic analysis showed that, weight (OR = 0.906; 95% CI, 0.839-0.978; P = 0.011), baseline platelet count (OR = 0.989; 95% CI, 0.977-1.000; P = 0.049), C(min) (OR = 1.545; 95% CI, 1.203-1.983; P = 0.001), and APACHE II score (OR = 1.130; 95% CI, 1.003-1.273; P = 0.044) were significant factors for linezolid-associated thrombocytopenia. The area under the ROC curve of the combined predictor was larger based on the above factors. When the Youden index was the maximum, the best optimal cut-off point was 205.6 on the ROC curve; when C(min) ≥ 2 mg/L, the probability of bacterial eradication was more than 80%; when C(min) ≥ 6.3 mg/L, the probability of thrombocytopenia was more than 50 %. In clinical practice, when the calculating results of the combined predictor ≤205.6, the risk of the development of thrombocytopenia may be higher. Furthermore, maintenance of C(min) between 2 and 6.3 mg/L over time may be helpful in retaining appropriate efficacy and reducing the associated thrombocytopenia.

Sequential, timely and controlled expression of hVEGF165 and Ang-1 effectively improves functional angiogenesis and cardiac function in vivo.

We aimed to control the gene expression of vascular endothelial growth factor (VEGF) and angiopoietin-1 (Ang-1) in the ischemic heart to explore the feasibility of sequential, timely and controlled multigene expression as a means of improving therapeutic angiogenesis in vivo. Adult rabbit myocardial infarction models were surgically established (n=120). Hypoxia-inducible factor-1α-hypoxic response element (HIF1α-HRE) and Tet (tetracycline)-On advanced gene control systems were reconstructed for controlled expression of the human VEGF165 (hVEGF165) and Ang-1 genes, respectively. Recombinant adeno-associated viruses (rAAV)-9HRE-hVEGF165 and rAAV-TRE-Tight-Ang-1 were delivered into the ischemic myocardium for 12 weeks. Reverse transcription-polymerase chain reaction, western blotting and immunofluorescence staining were used to detect gene and protein expression. Vessel functionality, vascular permeability and animal cardiac function were also evaluated. Under the control of the HIF1α-HRE and Tet-On gene control systems, the expression of the exogenous hVEGF165 and Ang-1 genes was consistent in the ischemia control. In the sequential group, we found that the number of functional vessels with a larger diameter and more vascular branches was increased, and vascular permeability was significantly reduced. In addition, animal heart function was significantly improved compared with the non-sequential and hVEGF165- or Ang-1-only groups (P<0.05, P<0.05, respectively). Sequential, timely and controlled expression of the hVEGF165 and Ang-1 genes in vivo is a new therapeutic angiogenesis strategy that can effectively promote functional vessel regeneration and can improve cardiac function in ischemic heart disease.

An assessment of teicoplanin use and monitoring serum levels in a Chinese teaching hospital.

OBJECTIVE: To validate a high performance liquid chromatography (HPLC) method for serum teicoplanin measurement and use the method for clinical monitoring of teicoplanin levels to analyze the clinical application of teicoplanin. METHODS: 55 patient profiles were collected and analyzed for the clinical teicoplanin application. 10 critically ill patients of the 55 cases were monitored for teicoplanin trough concentration using the HPLC method. RESULTS: The modified HPLC method exhibited excellent linearity, with correlation coefficient r = 0.9995. The intra-day and inter-day coefficients of variation were less than 10%. The lower limit of detection of teicoplanin was 5.63 mg/l. The recovery of teicoplanin was above 90%. Of the 55 patients in this study, there were 42 patients without load-dosing. There were only 29 patients treated with teicoplanin documented Gram-positive infections by etiological diagnoses. In the 10 patients with teicoplanin serum trough concentration monitoring, all cases received a loading dose of 400 mg every 12 h for 3 doses, and the mean trough concentration of teicoplanin was 10.82 ± 4.51 mg/l. The mean trough levels were 13.04 ± 6.23 mg/l in 4 patients with microbiological eradication and improvement of symptoms of diseases and 9.34 ± 2.61 mg/l in 6 patients with persistence of previous clinical infectious symptoms, respectively. CONCLUSION: The modified HPLC method is robust, highly reproducible and suited to monitor the concentration of teicoplanin. In critically ill Chinese patients, we should consider more appropriate loading doses and evaluate the relationship between teicoplanin trough concentration and the efficacy using microbiological and clinical parameters.

Isolation and characterization of a goose astrovirus 1 strain causing fatal gout in goslings, China.

In recent years, goose gout, a severe infectious disease, has affected the development of the goose industry in China. Two different genotypes of goose astrovirus (GAstV), named as GAstV-1 and GAstV-2, were identified. GAstV-2 viruses are known to be the causative agent of goose gout; however, GAstV-1 has not been isolated, and the relationship between GAstV-1 and goose gout is unknown. One full genome sequence, designated as GAstV/CHN/TZ03/2019 (TZ03), was determined from the clinical tissue samples of a diseased gosling using next-generation sequencing. The complete genome of TZ03 was 7,262 nucleotides in length with typical genomic characteristics of avastroviruses. The TZ03 strain shares the highest identity (96.6%) with the GAstV-1 strain FLX, but only 51.5 to 61.3% identity with other astroviruses in Avastrovirus. Phylogenetic analysis revealed that the TZ03 strain clustered together with the GAstV-1 strains FLX and AHDY and was highly divergent from GAstV-2 viruses. The TZ03 strain was successfully isolated from goose embryos and caused 100% mortality of goose embryos after 5 passages. Electron microscopy showed that the virus particles were spherical with a diameter of ∼22 nm. The clinical symptoms were reproduced by experimental infection of healthy goslings, which were similar to those caused by GAstV-2 strains. Our data show that GAstV-1 is one of the causative agents of the ongoing goose gout disease in China. These findings enrich our understanding of the evolution of GAstVs that cause gout and provide potential options for developing biological products to treat goose gout.

Detection of CTCs and CSCs in the staging and metastasis of non-small cell lung cancer based on microfluidic chip and the diagnostic significance.

OBJECTIVE: Dynamic monitoring of CTCs/CSCs can assist in the diagnosis and prognosis of tumors. This study explores the diagnostic significance of microfluidic chip technology in the detection of CTCs/CSCs in clinical staging and metastasis of patients with non-small cell lung cancer (NSCLC). That lays a solid foundation for the use of microfluidic chips to monitor CTCs/CSCs for the stage and metastasis of patients with non-small cell lung cancer. PATIENTS AND METHODS: This study collected 80 patients with lung cancer from October 2017 to October 2018. Meanwhile, 30 healthy people and 30 patients with benign lung diseases were selected during the same period as the control group 1 and the control group 2, respectively. CellSearch (Huntington Valley, PA, USA) and microfluidic chip were used to detect CTCs, the sensitivities were recorded. ELISA methods were used to detect the concentrations of tumor markers VEGF-C, CEA, and CA125 in serum, and their association with CTCs and CSCs was analyzed. In addition, after 3 months, we followed up 40 patients with lung cancer, recorded their prognosis, and extracted peripheral blood to detect changes in their CTCs and CSCs. The CellSearch (Huntington Valley, PA, USA) system and the microfluidic chip system were used to detect the CTCs in patients with lung cancer, and the sensitivity and specificity of the patients were analyzed. The changes in CTCs and CSCs in the peripheral blood of the patient were recorded. RESULTS: It can be seen that the positive rate of CTCs and CSCs is not significantly correlated with the patients' age, gender, pathological type (adenocarcinoma, squamous cell carcinoma), etc. They are significantly correlated with clinical stage (I + II and III + IV) and metastasis (metastasis and non-metastasis) (p<0.01). Then, we divided the patients into groups for testing, and analyzed the association between different groups of patients and CTCs and CSCs. Compared with control group 1 and control group 2, the positive rates of CTCs and CSCs in lung cancer metastasis group and non-metastasis group were significantly different (p<0.05). Compared with the control group 1 and control group 2, the positive rates of CTCs and CSCs in stage I + II and III + IV of lung cancer were significantly different (p<0.05). The positive rate was significantly higher in the cancer metastasis group (p<0.05). The concentrations of tumor markers VEGF-C, CEA, CA125 in the serum of patients were consistent with CTCs-negative and CTC-positive lung cancer, with significant differences (p<0.05). CSCs negative and CSCs positive patients have similar results. Subsequently, we analyzed the sensitivity and specificity of CSCs, CTCs, and tumor markers for the diagnosis of NSCLC. The results showed that the sensitivity of CSCs and CTCs to diagnose patients was significantly higher than that of tumor markers. CONCLUSIONS: This study shows that our microfluidic chip device can exhibit relatively good performance and can better detect CTCs and CSCs. Monitoring CTCs and CSCs of patients can provide a basis for judging the stage and metastasis of patients.

PAX-5 is invariably expressed in B-cell lymphomas without plasma cell differentiation.

AIMS: The B-cell-specific transcription factor PAX-5 is physiologically expressed in normal B cells and silenced in plasma cells. The aim of this study was to determine whether PAX-5 expression is universal among B-cell malignancies. METHODS AND RESULTS: A wide spectrum of B-cell malignancies were subjected to immunohistochemical analysis for PAX-5 expression. The study was especially focused on cases lacking CD20, such as precursor B-cell acute lymphoblastic leukaemia (preB-ALL), CD20- B-cell lymphomas, classical Hodgkin's lymphoma (CHL) and B-cell lymphomas with significant plasmacytic differentiation. Strong PAX-5 expression was identified, without exception, in all cases of CD20+ B-lymphoproliferative disorders. It was also invariably detected in 31/31 cases of preB-ALL, 14/14 cases of CD20- diffuse large B-cell lymphoma without plasmacytic differentiation and 26/26 CD20- B-cell lymphoma status post rituximab treatment. The vast majority of CHLs had unequivocal PAX-5 expression of varying intensity (80/86). However, variants of B-cell malignancies with characteristic plasmacytic differentiation exhibited no detectable PAX-5 expression (0/17). CONCLUSIONS: PAX-5 is the most sensitive and reliable immunohistochemical marker for B-cell malignancies. Lack of PAX-5 expression correlates with the presence of marked plasma cell differentiation.

[Correlation between serum 25-hydroxyvitamin D level and core symptoms of autism spectrum disorder in children].

Objective: To explore the relationship between serum 25-hydroxyvitamin D levels and core symptoms of autism spectrum disorder (ASD) in children. Method: In this cross-sectional study, ASD children 4 to 6 years of age who were diagnosed in Department of Developmental and Behavioral Pediatrics, First Hospital of Jilin university from January to May 2017 were assigned to ASD group, and children for routine growth and development assessment in Jilin province were assigned to control group. The two groups were well matched for age and sex, and none of them had received vitamin D supplementation. Serum 25-hydroxyvitamin D levels were measured by HPLC-MS/MS method. The patients of the ASD group were assessed with autism behavior checklist (ABC), childhood autism rating scale (CARS), social response scale (SRS), and autism treatment evaluation checklist (ATEC). The levels of vitamin D were divided into normal(>0.03 ng/L), insufficient (0.01-0.03 ng/L) and deficient (<0.01 ng/L). Levels of serum vitamin D between the two groups were compared by two independent sample t-test, and the difference in the percentages of normal, insufficient and deficient levels of vitamin D was tested by chi-square test, and correlations between vitamin D levels and the total scores or subscales of ABC, CARS, SRS and ATEC were analyzed by Pearson correlation analysis. Result: The 87 subjects in the ASD group included 75 males and 12 females, with a mean (±SD) age of (4.7±0.7) years. The 301 subjects in the control group included 249 males and 52 females, with a mean (±SD) age of (4.8±0.8) years. Serum vitamin D level in ASD children was significantly lower than that of the control group ( (0.021±0.008) vs. (0.036±0.016) ng/L, t=-8.17, P<0.01), and the between-group percentage difference of normal, insufficient and deficient levels of vitamin D was statistically significant (12 (14%) vs. 186 (62%) , 67 (77%) vs. 113 (37%) , 8 (9%) vs. 2 (1%) , χ(2)=72.1, P<0.01). There were negative correlations between serum vitamin D level in ASD children and total ABC score or ABC subscale scores (body behavior, self-care, language and social interaction)(r=-0.531,-0.397,-0.283,-0.248,-0.262, P=0.000, 0.000, 0.007, 0.020, 0.014). There were negative correlations between serum vitamin D level in ASD children and total CARS score and CARS subscale scores (imitation, nonverbal communication and general impression) (r=-0.352, -0.216, -0.248, -0.216, P=0.001, 0.046, 0.021, 0.046). There were negative correlations between serum vitamin D level in ASD children and SRS behavior subscale or ATEC social interaction subscale (r=-0.536, P=0.005, r=-0.400, P=0.014). Conclusion: Serum 25-hydroxyvitamin D level in children with ASD is obviously lower than that in the healthy control group, and there are negative correlations between vitamin D levels and core symptoms of ASD. Trial registration Chinese Clinical Trial Registry, ChiCTR-CCC-13004498.

Market assessment of tuberculosis diagnostics in China in 2012.

OBJECTIVE: To assess the 2012 served available market for tuberculosis (TB) diagnostics in China in the sector served by the China Centre for Disease Control and Prevention (CDC) and the hospital sector in China, including both designated TB hospitals and general hospitals. DESIGN: Test volumes and unit costs were assessed for tuberculin skin tests, interferon-gamma release assays (IGRAs), smear microscopy, serology, cultures, speciation tests, nucleic-acid amplification tests (NAATs), drug susceptibility tests and adenosine-deaminase tests (ADA). Data were obtained from electronic databases (CDC sector) and through surveys (hospital sector), and were estimated for the two sectors and for the country as a whole. Test costs were estimated by staff at China CDC, and using published literature. RESULTS: In 2012, the China CDC and hospital sectors performed a total of 44 million TB diagnostic tests at an overall value of US$294 million. Tests used by the CDC sector were smear microscopy, solid and liquid culture and DST, while the hospital sector also used IGRAs, NAATs, ADA and serology. The hospital sector accounted for 76% of the overall test volume and 94% of the market value. CONCLUSION: China has a very large TB diagnostic market that encompasses a wide range of diagnostic tests, with the majority being performed in Chinese hospitals.

Site-dependence of invasiveness of ECA109 human oesophageal carcinoma cells in nude mice.

ECA109 human oesophageal carcinoma cells were injected either subcutaneously or intraperitoneally into BALB/CATc 1-nu/nu mice. After 23 weeks tumours were examined histologically and by scanning electron microscopy. Subcutaneous ECA109 tumours were well-delineated without signs of invasion. By contrast, intra-abdominal tumours invaded into the abdominal wall and abdominal organs. This result provides us with another example of site-dependence of invasion in vivo.

Synthesis of poly(ADP-ribose) in asbestos treated rat pleural mesothelial cells in culture.

To investigate the origin of DNA repair in rat pleural mesothelial cells (RPMC) exposed to asbestos fibers, poly(ADP-ribose) polymerase (PARP) activity was measured in the asbestos-treated cells. As bleomycin has been shown to activate poly(ADP-ribose) synthesis in several cell systems, the response to bleomycin with regard to PARP assay was first investigated. Bleomycin produced a dose-dependent increase of poly(ADP-ribose) synthesis in RPMC. Likewise both chrysotile and crocidolite fibers produced a concentration-dependent PARP activation indicating that the formation of DNA strand breaks is one type of damage produced by asbestos in RPMC. Enhancement of DNA repair, assessed by the measurement of [3H] methylthymidine incorporation in growth arrested cells, was not detectable in the presence of 3-methoxybenzamide (3-MBA), a PARP inhibitor, confirming a relation between PARP activation and DNA repair. The participation of DNA breakage in asbestos toxicity on RPMC was determined by the colorimetric 3-4(5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. There was no relationship between DNA breakage and cytotoxicity since the use of PARP inhibitors did not change cell viability. These results indicate that asbestos produce DNA damage that is repaired in RPMC.

[Studies on the gap junctional intercellular communication of human nasopharyngeal carcinoma cells and effect of RII].

To evaluate the effects of gap junctional intercellular communication (GJIC) on the growth, invasion and metastasis of tumor, human nasopharyngeal carcinoma (HNPC) parent cell line (CNE-2Z) and its variants (L2, H2, L4) with different invasive and metastatic potential were examined in vitro. Only a few intermediate junction (IJ) but no gap junction (GJ) structures were observed under EM. The parent line cells showed marked GJIC, while its variants lacked this function by SLDT technique. It was further shown that L2 cell line (variant with high invasive potential) had lower concentration of cytosolic free calcium ([Ca2+]i) compared to H2, L4 cell lines (variants with medium and low invasive potential, respectively). It reflected that some correlation may exist between [Ca2+]i level and the invasive potential of HNPC cell lines. The effect of RII on GJIC of HNPC was also investigated. After 3-7 ds of RII (0.0001 mol/L) treatment, there was no change in the number of GJs. The GJIC function of CNE-2Z weakened and then disappeared finally with prolonged RII treatment. The level of [Ca2+]i in HNPC cells apparently fell after 6h of RII treatment, and rose to original level with persistent RII treatment. Whether the fluctuating of [Ca2+]i level relates the inhibitory effect of RII treatment. Treatment on the growth and invasion needs to be further studied.