[Effect of zirconia personalized gingival penetration on peri-implant soft and hard tissue of thin gingival biotypes in the anterior region: a retrospective study].

Objective: To investigate the effect of zirconia personalized gingival structure on peri-implant soft and hard tissue stability after single-tooth implant restorations in patients with thin gingival biotypes in the anterior region, with a view to provide a clinical guideline. Methods: This retrospective study included 20 patients with thin gingival biotype and implant restorations in the anterior region. These patients included 9 males and 11 females, and the age was (35.2±10.3) years. The patients were from the Department of Periodontal Implantology, Stomatology Hospital, Southern Medical University from January 2018 to December 2022. Computer-aided design/computer-aided manufacturing (CAD/CAM) techniques were used to fabricate a titanium base zirconia personalized gingival structure to maintain the soft-tissue perforated gingival contour of the anterior esthetic zone. This structure consists of two modalities: titanium base + zirconia outer crown or titanium base personalized zirconia abutment + zirconia outer crown. Clinical outcomes were recorded immediately and after delivery of the final restorations. Implant retention was recorded, esthetic scoring was performed using the pink esthetic index, the amount of bone resorption at the implant margins was measured based on digitized apical radiographs, and periodontal health was evaluated using the modified plaque index and the modified bleeding index. Results: The survival rate of the 20 implants was 100% after 3 years of wearing the final restorations, with a pink aesthetic score of 9.3±0.9. Bone resorption at the proximal and distal mesial margins of the implants was 0.09 (-0.21, 0.20) mm, 0.17 (-0.12, 0.27) mm after 3 years, respectively, and the difference was not statistically significant when compared to bone resorption immediately after placement of the final restoration (0) (Z=-1.03, P=0.394; Z=-2.05, P=0.065). Conclusions: Zirconia personalized gingival structure maintains the stability of peri-implant hard and soft tissues of thin gingival biotypes in the anterior region.

[Analysis of the epidemiological traits of occupational pneumoconiosis in Qinhuangdao between 1961 and 2020].

Objective: To study the prevalence of occupational pneumoconiosis in Qinhuangdao from 1961 to 2020 and offer a foundation for developing occupational pneumoconiosis prevention and control methods. Methods: In December 2020, the data of occupational pneumoconiosis cases diagnosed by medical institutions with occupational disease diagnosis qualifications in Qinhuangdao City from 1961 to 2020 were collected Anova or kruskal-Walls tests and chi-square tests were used for inter-group comparisons of continuous and categorical variables, and LSD tests or Tamhane T2 tests were used for multiple comparisons. Results: Between 1961 and 2020, 384 cases of pneumoconiosis were documented in Qinhuangdao, of which 382 (99.5%) patients were men and 2 (0.5%) were women. The average dust service duration is 15 (9, 25) years, with a minimum duration of 0.5 years and a maximum duration of 49 years; Cases were primarily distributed in Qinglong Manchu Autonomous County (187 cases, 48.7%) and the Haigang district (160 cases, 41.7%) ; Type of pneumoconiosis was silicosis (340 cases, 88.5%), mainly 273 cases (71.1%) of stage I, 88 cases (22.9%) of stage II, and 23 cases (6.0% of stage III) ; Cases of Phase II and III and with short lengths of service are mainly concentrated in medium-sized, small, private limited liability companies and collective enterprises. Rrock work (166 cases, 43.2%), and loading kiln workers (42 cases, 10.9%) were the main types. Conclusion: Because the distribution of pneumoconiosis cases in Qinhuangdao city is concentrated and the length of service is decreasing, it is important to enhance the oversight of important area, businesses, industries, and job categories in line with the growth of the region's mineral resources.

[Clinical observation of orthokeratology with increased compression factor in the treatment of myopia].

Objective: To discuss the efficacy and safety of orthokeratology with increased compression factor (ICF) in myopia correction in children. Methods: It was a prospective cohort study. Data of the right eyes of myopic children who visited the First Affiliated Hospital of Chengdu Medical College for orthokeratology were collected continuously from May 2016 to Dec 2018. All children had low myopia (<3.00 D) or moderate myopia (≥3.00 D), and were grouped using random numbers in Excel to receive orthokeratology with ICF or conventional compression factor (CCF). The axial length (AL), spherical equivalent (SE), best corrected visual acuity (BCVA), near visual acuity (NVA), Efron grade, corneal hysteresis (CH), corneal resistance factor (CRF), corneal-compensated intraocular pressure (IOPcc), tear film break-up time (BUT), higher-order aberrations (HOAs), accommodative amplitude (AA) and accommodative facility (AF) were compared between groups during the 1-year treatment period. The Chi-squared test was used to compare the categorical data, while the independent-sample t-test was performed to assess the measurement data. Results: After 1 year of treatment, there were no statistical differences in AL, SE, BCVA, NVA, Efron grade, CH, CRF, IOPcc, BUT, HOAs, AA and AF between the low myopia ICF group and the low myopia CCF group (all P>0.05). After 6 months of treatment, the AL increased by (0.05±0.03) mm in the moderate myopia ICF group and by (0.08±0.04) mm in the moderate myopia CCF group (t=-3.416, P=0.001). After 1 year of treatment, the AL increased by (0.12±0.04) mm in the moderate myopia ICF group and by, (0.16±0.05) mm in the moderate myopia CCF group (t=-4.017, P<0.001). The SE was (-0.16±0.40) D in the moderate myopia ICF group, significantly different from that in the moderate myopia CCF group [(-0.58±0.60) D; t=3.529, P=0.001]. There were also statistical differences in HOAs, spherical aberrations and AF (all P<0.05), but no statistical differences in BCVA, NVA, Efron grade, CH, CRF, IOPcc, BUT and AA between the two groups (all P>0.05). Conclusions: Orthokeratology with ICF safely and effectively corrected myopia in children during the observation period. It could control the progression of moderate myopia more effectively than that of low myopia.

WT1 Inhibits Human Renal Carcinoma Cell Proliferation and Induces G2/M Arrest by Upregulating IL-24 Expression.

The transcription factor Wilms' tumor 1 (WT1) is involved in development, tissue homeostasis, and disease. However, the exact roles and the mechanisms of WT1 in renal carcinoma are not well understood. Therefore, in this study, we evaluated the ability of WT1 to block proliferation in renal carcinoma cells in vitro. Experimental analysis showed that WT1 overexpression inhibited the proliferation of renal carcinoma A498 cells and promoted arrest at the G2/M checkpoint. RNA-Seq identified differentially expressed genes, including IL-24, related to both the cell proliferation and the cell cycle. WT1 overexpression upregulated IL-24 expression, and IL-24 overexpression induced G2/M arrest. ChIP-Seq identified JUN as a direct target of WT1 in A498 cells, in which positive regulation was shown by RT-qPCR. It has been shown that the transcription factor JUN can regulate IL-24 expression, and therefore, we hypothesize that WT1 might regulate the IL-24 through JUN. Furthermore, analysis based on TCGA datasets showed that the expression of WT1-regulated genes, including TXNIP and GADD45A, was significantly correlated with the stage and histological grade of tumors, with high levels linked to favorable prognoses. Our results demonstrated that the overexpression of WT1 upregulates IL-24, leading to G2/M checkpoint arrest to reduce proliferation. These results indicate that regulation of IL-24 by WT1 inhibits proliferation and may represent a potential target for treating renal carcinoma.

[Effect of miR-23b on the malignant phenotype and the sensitivity of lenvatinib in human hepatocellular carcinoma cells].

Objective: To investigate the effect of miR-23b on the malignant phenotype and the sensitivity of lenvatinib in human hepatocellular carcinoma cells. Methods: Human hepatocellular carcinoma cell line HepG2, SMMC-7721 and QGY-7703 were transfected with miR-23b mimic and its control, respectively. CCK-8 and EdU assay were used to detect cell proliferation. Transwell assay were used to detect changes in cell migration and invasion. Tube formation assay were used to detect vasculogenic mimicry formation. The comparison of the mean between groups was analyzed by t-test. Results: CCK-8 results showed that the A values ​​of human hepatocellular carcinoma cell line HepG2 and SMMC-7721 in the miR-23b mimic group were 0.325 ± 0.011 and 0.537 ± 0.026, respectively, which were significantly lower than the control group 0.430±0.017 and 0.752 ± 0.051 (P < 0.05). Transwell assay result showed that the number of cell migration of human hepatocellular carcinoma cell line HepG2 and SMMC-7721 in the miR-23b mimic group was (517.220 ± 32.873) and (242.327 ± 20.793), respectively, which were significantly lower than that of the control group (724.130 ± 15.142) and (424.432 ± 27.212) (P < 0.01). Simultaneously, the number of cell invasions in the miR-23b mimic group were (55.671 ± 7.514) and (64.670 ± 6.011), respectively, which were significantly lower than those in the control group (124.320 ± 11.782) and (156.204 ± 12.501) (P < 0.01). Tube formation assay showed that the number of tube forming branches of hepatocellular carcinoma cell line QGY-7703 and SMMC-7721 in the miR-23b mimic group was (489.824 ± 42.035) and (435.201 ± 44.143), respectively, which were significantly lower than that of the control group (878.620 ± 31.618) and (785.430 ± 38.723) (P ​​< 0.01). In addition, EdU results showed that after miR-23b combined with lenvatinib, the positive rates of EdU staining of hepatocellular carcinoma cell line HepG2 and SMMC-7721 in the miR-23b mimic group were (32.905 ± 1.342)% and (24.811 ± 0.820)%, respectively, which were significantly lower than the control group (52.623 ± 2.441)% and (38.702 ± 1.312)% (P < 0.05). Conclusion: miR-23b can inhibit the proliferation, migration, invasion and vasculogenic mimicry formation, and enhance the sensitivity of lenvatinib drug in human hepatocellular carcinoma cells.

[Comparative study on metagenomics of esophageal flora in elderly and middle-aged esophageal squamous cell carcinoma patients].

Objective: To explore the flora characteristics and differences of esophageal tissues between elderly esophageal squamous cell carcinoma (ESCC) patients and young and middle-aged ESCC patients, so as to assist in studying the potential biomarkers of elderly ESCC patients. Methods: In this study, a retrospective study was adopted. 72 ESCC patients diagnosed in Taihe Hospital, Shiyan City, Hubei Province from July 2018 to July 2019 were selected, including 49 patients in the elderly group (≥ 60 years old, 40 males and 9 females), 23 patients in the young and middle-aged group (<60 years old, 21 males and 2 females). In the same period, 20 healthy persons without abnormal gastroscopy in endoscopy center were selected as the control group (aged 35-78 years old, median age 57 years old, 16 males and 4 females). The genomic DNA was extracted from the affected esophageal tissues of patients with ESCC and the middle esophageal samples of the control group. The V4 hypervariable region of bacterial 16SrRNA gene sequence was amplified. Illumina HiSeq sequencing technology was adopted. The flora characteristics of elderly, young and middle-aged ESCC patients was compared and analyzed. QIIME and Rstudio software were used to analyze the sequence data, and nonparametric Kruskal-Wallis test or Wilcoxon rank sum test were used for statistical methods. Results: Shannon index [5.17 (4.53, 5.95) vs. 4.79 (3.74, 5.97)], Simpson index [0.94 (0.91, 0.96) vs. 0.92 (0.83, 0.96)] and Chao1 index [343.55 (259.76, 570.59) vs. 329.16 (268.88, 648.00)] were similar in flora of two groups, and there was no significant difference (Z=-0.791, -1.057, -0.380, all P>0.05). There was no significant difference in ß-diversity between the elderly group and the young and middle-aged group (PC1=19.14%, PC2=6.95%, PPC1=0.67, PPC2=0.42). At the phyla level, the top 5 phyla in abundance were as follows: Firmicutes, Bacteroidetes, Proteobacteria, Actinobacteria and Fusobacteria in the young and middle-aged group, while the top 5 phyla in abundance were as follows: Firmicutes, Bacteroidetes, Proteobacteria, Fusobacteria and Actinobacteria in the elderly group; the significant difference between the two groups was Fusobacteria (Q=0.596, P<0.05). At the genus level, the top 5 genera in the young and middle-aged group in abundance were as follows: Prevotella, Bacteroides, Streptococcus, Selenomonas and Veillonella. In the elderly group, Prevotella, Bacteroides, Streptococcus, Selenomonas and Haemophilus were the top 5 in abundance, and there were significant difference in Fusobacterium between the two groups (Q=0.938, P<0.05). PICRUSt function prediction showed that the abundance of Aminoacyl.tRNA.biosynthesis, Nucleotide.excision.repair, RNA.polymerase, Ribosome, Clavulanic.acid.biosynthesis, Photosynthesis and Photosynthesis. proteins in the elderly group were lower than those in the young and middle-aged group (all Q=0.734, P<0.05). Conclusion: There is no significant difference in α-diversity and ß-diversity between elderly ESCC patients and young and middle-aged patients, but the abundance of Fusobacterium flora increased.

Association between olfactory function and quality of life in patients with olfactory disorders: a multicenter study in over 760 participants.

BACKGROUND: This cross-sectional, multi-centric study aimed to investigate the differences in quality of life among patients with olfactory dysfunction (OD) of different origin, and to identify factors associated with olfactory-related quality of life (QOL). METHODS: Seven hundred sixty-three adults were recruited from 8 Smell & Taste clinics in Germany, Switzerland, and Austria. Olfactory-related QOL was assessed by the Questionnaire of Olfactory Disorders (QOD). Olfactory function was assessed with the "Sniffin' Sticks" test; self-assessment was performed with visual analog scales. RESULTS: Patients with post-infectious and post-traumatic OD showed poorer olfactory-related QOL than patients with sinonasal and idiopathic OD. The olfactory-related QOL was positively associated with the "Sniffin' Sticks" test score, self-assessed olfactory function, disease duration, and age, with younger olfactory dysfunction patients showing lower QOL. Female patients presented with poorer olfactory-related QOL. In addition, the results showed that self-assessment of olfactory function explained more of the variance in olfactory-related QOL than olfactory function evaluated by the Sniffin’ Sticks test. CONCLUSIONS: In addition to the psychophysical testing results, several factors such as disease cause, disease duration, sex, or self- assessed olfactory dysfunction should be taken into account when assessing the individual severity of the smell loss.

Deep small RNA-Seq reveals microRNAs expression profiles in lactating mammary gland of 2 sheep breeds with different milk performance.

Micro ribonucleic acid (miRNA) is a type of noncoding RNA, and it has been revealed to play important roles in the activity of the mammary gland (MG) in some species. However, the function of miRNAs in MG of sheep is poorly understood. In the study, Gansu Alpine Merino (GAM; n = 9) and Small-tailed Han sheep (STH; n = 9) with different milk production traits were investigated. Microstructures and the expression profile of miRNAs of MG tissues at peak lactation were studied. Mature alveolar lumens of MG in appearance were larger in STH than GAM. The expression levels of CSN2 and the content of rough endoplasmic reticulum were also higher in STH ewes than GAM ewes. A total of 124 mature miRNAs were expressed, and 18 of these were differentially expressed between the 2 breeds. The KEGG analysis results showed that the targeted genes of differentially expressed miRNAs were mainly involved in some metabolic pathways and signaling pathways related to MG development, milk protein, and fat synthesis. The findings in the study can improve our understanding of the roles of miRNAs in the development and lactation of MG in sheep.

[Application of two-stage crestal approach sinus elevation in severe atrophic posterior maxilla].

Objective: To investigate the feasibility of two-stage crestal approach sinus elevation in severe atrophic maxilla. Methods: A total of 25 patients (male: 13 cases,female: 12 cases) who attended Department of Implant Center, Stomatological Hospital, Southern Medical University from May 2016 to May 2018 were included in this study. The age of the patients was 32-49 years old. The inclusion criteria were: single or multiple tooth loss in posterior maxilla with residual bone height ranged from 1.5 to 3.0 mm and vertical bone width≥6 mm, no pathological changes or septum were detected in the sinus. The elevated sides were divided into three groups according to different buccal-palatal sinus width (SW): wide (16 case, SW＞15 mm), normal (12 case, 12 mm≤SW≤15 mm), narrow (5 case, SW<12 mm). Finally, 23 patients with 33 implants were placed by the two-stage crestal approach for sinus elevation. Six months after implant placement, final restorations were delivered. Implant survival rate, implant stability quotient (ISQ), immediate vertical bone height (VBH) after surgeries, changes of sinus elevation height (cSEH), marginal bone loss (MBL) at 1 year follow-up were examined. Results: Twenty-three patients were finally included in the study, including 12 males and 11 females, aged (41.2±7.6) years old. All implants healed uneventfully. ISQ (wide: 50.81±2.69; normal: 60.58±2.54; narrow: 63.12±3.58), immediate VBH after 1st surgery [wide: (7.99±1.13) mm; normal: (8.95±0.81) mm; narrow: (9.18±0.90) mm] and 2nd surgery [wide: (11.46±0.88) mm; normal: (12.77±0.49) mm; narrow: (12.57±0.55) mm], cSEH six months after 1st [wide: (3.87±0.43) mm; normal: (2.01±0.65) mm; narrow: (1.49±0.33) mm] and 2nd [wide: (1.16±0.29) mm; normal: (1.04±0.33) mm ; narrow: (0.97±0.41) mm] surgery, MBL [wide: (0.91±0.05) mm; normal: (0.79±0.10) mm; narrow: (0.74±0.07) mm] were significantly different among three groups (P<0.05). In all the three groups, cSEH was barely detected at 1-year follow-up (P>0.05). Conclusions: Two-stage crestal approach for sinus elevation might be an alternative protocol in severe atrophic posterior maxilla, especially in cases with narrow and normal buccal-palatal width. There is an urgent need for long time follow-up and more clinical cases.

The clinical value of the combined detection of sEGFR, CA125 and HE4 for epithelial ovarian cancer diagnosis.

OBJECTIVE: This study aims to investigate the clinical value of combined detection of serum soluble epidermal growth factor receptor (sEGFR), cancer antigen 125 (CA125), and human epididymis protein 4 (HE4) in the diagnosis of epithelial ovarian cancer (EOC). PATIENTS AND METHODS: From December 2017 to October 2018, the serum samples were obtained from the Affiliated Hospital of Xuzhou Medical University, with 30 patients as EOC group, 30 patients with benign ovarian neoplasms as benign group, and 17 healthy subjects as healthy group. Besides, among 30 EOC patients, 9 serum samples were obtained from pre-operative and post-operative EOC patients. The levels of serum sEGFR were detected by enzyme-linked immunosorbent assay (ELISA), while CA125 and HE4 were detected by enhanced chemiluminescence immunoassay (ECLIA). The diagnostic value was evaluated by receiver operating characteristic (ROC) curve analysis. RESULTS: The levels of serum sEGFR, CA125, and HE4 in EOC group were significantly higher than those in benign group (p<0.05) and healthy group (p<0.05). When using a single tumor marker, the CA125 shows the highest sensitivity (93.30%) and HE4 shows the highest specificity (97.87%). The specificity of combined detection of serum sEGFR, CA125, and HE4 was 100%, which was significantly higher than that using a single tumor marker. The area under the ROC curve (AUC) of combined detection of serum sEGFR, CA125, and HE4 (0.965) was much higher than that of the single detection and higher than that of combined detection of CA125 and HE4 (0.940). Moreover, the level of serum sEGFR in post-operative EOC group was significantly lower than that in the corresponding pre-operative EOC group (p<0.05). CONCLUSIONS: Our study shows that combined detection of serum sEGFR, CA125, and HE4 increases the specificity and efficiency in EOC diagnosis, indicating that sEGFR could be a potential biomarker for the diagnosis and prognosis of EOC.

Down-regulation of microRNA-21 inhibits cell proliferation and invasion of high-invasion liver cancer stem cells.

OBJECTIVE: Cancer stem cells (CSCs) play critical roles in tumorigenesis, tumor recurrence and metastasis. This study aims to investigate the effects of small interfere microRNA-21 RNA (miR-21 RNAi) on cell proliferation, invasive ability of high-invasion liver cancer stem cells (H-ILCSCs), HCCLM3 and HL-7702 cells. MATERIALS AND METHODS: pLVX-shRNA2 lentiviral vector system was established, packaged and transfected into H-ILCSCs, HCCLM3 and HL-7702 cells. Cell counting kit-8 (CCK-8) assay was performed to observe cell viabilities of cells. Transwell assay was conducted to evaluate the invasion potential of H-ILCSCs, HCCLM3 and HL-7702 cells. Quantitative PCR (qPCR) assay was used to examine the miR-21 levels in different cell lines. RESULTS: pLVX-anti-miR21 lentiviral vector system was successfully established. miR-21 levels were down-regulated in anti-miR-21 gene steady expression cell lines compared to untreated cells (p<0.05). miR-21 levels were significantly lower in H-ILCSC2-LV-anti-miR-21 group compared to HCCLM3-anti-miR-21 and HL7702-anti-miR-21 (p<0.05). miR-21 inhibition significantly decreased cell proliferation and invasion compared to untreated cells (p<0.05). Cell proliferation and invasive ability of H-ILCSC2-LV-anti-miR-21 group were significantly higher compared to HCCLM3-anti-miR-21 and HL7702-anti-miR-21 (p<0.05). There were even not effects of miR-21 RNAi treatment on the cell proliferation and invasion of HL-7702 cells. CONCLUSIONS: The down-regulation of miR-21 significantly inhibited the cell proliferation and invasion abilities of H-ILCSCs and HCCLM3 cells, and illustrated higher effects on H-ILCSCs.

[Seroepidemiological investigation of hepatitis C virus in Zhejiang Province: a hospital-based study].

Objective: To study serum HCV antibody (anti-HCV) with geographic distribution characteristics in Zhejiang Province. Methods: A stratified random cluster sampling method was used. Serum samples of the surveyed population were collected from selected hospitals, anti-HCV antibodies were examined, then hepatitis C infection rates among different genders, regions and age groups were analyzed. The anti-HCV rate was compared using the χ (2) test. Results: The average anti-HCV positive rate in Zhejiang Province was 0.24% [95% confidence interval (CI): 0.16% ~ 0.32%]. The antibody positive rate in the plain area was 0.32% (95% CI: 0.19% ~ 0.45%), which was significantly higher than the coastal islands 0.05%(95% CI: 0.00% ~ 0.12%, χ (2) = 7.638, P < 0.05). There was no significant difference between plain area and hilly area 0.22% (95% CI: 0.03% - 0.41%). There was no statistically significant difference in anti-HCV positive rates between males and females (χ (2) = 2.238, P = 0.135). The highest positive rate of anti-HCV (0.93%) was in the population aged 56-60 years and the lowest in the population aged less than 20 years. Anti-HCV positive rate of all age groups in 2017 was lower than that of 2006 seroepidemiological study of hepatitis C. Conclusion: Zhejiang Province is a region with low anti-HCV positive rate and the disease prevalence further reduced than 10 years ago. The positive rate of anti-HCV in plain areas is higher than islands. Middle-aged and elderly people are the age group with high prevalence, and the anti-HCV positive rate in people under 20 years old is exceptionally low. Gender differences in anti-HCV positive rate have little effect.

Expression and clinical significance of miR-181a and miR-203 in systemic lupus erythematosus patients.

OBJECTIVE: MiR-181a plays a critical role in modulating T cell and B cell differentiation, as well as immune response. Its abnormal expression probably participates in the pathogenesis of systemic lupus erythematosus (SLE). MiR-203 is involved in regulating Toll-like receptor and inducing immune tolerance. Abnormal expression or function of miR-203 is related to multiple auto-immune diseases but its role in SLE remains unclear. This study, thus, investigated the serum level of miR-181a and miR-203, to analyze their roles in diagnosing and evaluating SLE. PATIENTS AND METHODS: SLE patients were recruited from our hospital, and divided into non-active and active SLE based on disease activity index, along with healthy individuals. qRT-PCR was used to quantify the serum miR-181a and miR-203 expression, and their correlation with clinical features. ROC was used to evaluate the diagnostic value on SLE, while survival curves were compared to show progression-free survival (PFS) between populations with high and low expression. RESULTS: SLE patients had significantly higher serum levels of miR-181a and lower miR-203, both of which were correlated with SLE activity. Expression levels of miR-181a and miR-203 were correlated with erythrocyte sedimentation rate, C reactive protein, anti-dsDNA antibody, complements, and SLEDAI score. Their expression levels had certain values in the differential diagnosis for active SLE (AUC=0.885 and 0.843). PFS in miR-181a high-expression individuals was lower than that in the low-miR-181 group (χ2=7.474, p=0.029). Whilst, miR-203 high-expression SLE patients had higher PFS than low-expression group (χ2=4.367, p=0.037). CONCLUSIONS: SLE patients had higher miR-181a and lower miR-203 expression, which thus may have critical implications in disease diagnosis and evaluation.

[Effect of sandblasting on bending strength and subcritical crack growth of the dental zirconia ceramics].

Objective: To evaluate the effect of sandblasting on bending strength and subcritical crack growth (SCG) under cyclic loading of yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) ceramics. Methods: After being polished, sixty bar-shaped specimens of Y-TZP (Wieland zirconia ceramics) were assigned to two groups (n=30) according to the random number table, the sandblasting group (SG) which was treated with sandblasting and the control group (CG) which remained untouched. In each group, half of the specimens (n=15) were subjected to bending strength test, and the results were examined by Weibull statistics and analyzed with ANOVA. The other 15 specimens in each group were subjected to fatigue tests. The results were examined by Weibull statistics and subcritical crack propagation rates were calculated. Results: The bending strengths of SG and CG were (1 291±133) and (1 140±124) MPa (F=10.117, P=0.004), and the Weibull modules of the two groups were 11.06 and 10.64 respectively. The crack growth rate of SCG of SG was lower than that of CG under the same cyclic loading. Conclusions: Proper sandblasting on Y-TZP ceramic can increase its bending strength and resistance to SCG.

[Current advance in saliva-derived exosome study].

There is growing interest in the whole saliva as a diagnostic fluid because of the relatively simple and non-invasive collection. Research on salivary proteomic and genomic has greatly facilitated the diagnosis and therapy of oral diseases, also revealed the molecular mechanism of the diseases. Saliva-derived exosome as a new source, with various molecular constituents of their cells of origin, including proteins, mRNA and miRNA might serve as potential biomarker. This article reviews the biological properties of saliva exosome, its separation and other aspects associated with disease.

Association between dopamine D2 receptor gene polymorphisms and the risk of heroin dependence.

Heroin dependence is a chronic relapsing brain disease. Researchers have reported that the dopamine D2 receptor (DRD2) is involved in the development of opiate dependence. To identify markers that contribute to the genetic susceptibility to heroin addiction, we examined the potential association between heroin dependence and six polymorphisms of the DRD2 gene using the MassARRAY system. Three hundred and thirty-four patients with heroin dependence and 299 healthy controls participated in the research. Compared with the healthy controls, heroin-dependent patients had a significantly lower frequency of the AA genotype of rs6275 (P = 0.038), and a significantly higher frequency of the C allele of rs1125394 (P = 0.030). Statistically significant differences were observed in the genotypic and allelic frequencies of rs17115583 (P = 0.005 and P = 0.001, respectively) and rs1079597 (P = 0.03 and P = 0.02, respectively). Haplotype analysis revealed that the T-G-A (block 1) haplotype of the DRD2 gene conferred a protective effect (P = 0.020). These findings point to a role for DRD2 polymorphism in heroin dependence in the Chinese Han population, and may be informative for future genetic or neurobiological studies on heroin dependence.

Association of the VRK2 gene rs3732136 polymorphism with schizophrenia in a Northwest Chinese Han population.

Previous studies have found that the vaccinia related kinase 2 gene (VRK2) polymorphism was associated with schizophrenia (SCZ) in the worldwide population. This association was further supported by VRK2 mRNA expression patterns and brain structure variations. Here, we analyzed four single nucleotide polymorphisms (SNPs) of the VRK2 gene in a total population of 893 samples, consisting of 360 patients with SCZ and 533 healthy controls of Han Chinese descent using the SNPscan method. Single SNP, haplotype, and gender-specific association analyses were performed. We found that rs3732136 was significantly associated with SCZ (P = 0.042; odds ratio = 1.25; 95% confidence interval = 1.01-1.55). Further genotype and haplotype association analyses suggested a similar pattern. Our data provide preliminary evidence that the VRK2 gene might play a major role in the development of SCZ in the Northwest Chinese Han population.

A novel variant of the ß-lactamase ADC-61 gene in multi-drug resistant Acinetobacter baumannii.

The aim of this study was to investigate the existence of a ß-lactamase gene in a group of multi-drug resistant Acinetobacter baumannii. Twenty strains of multi-drug resistant A. baumannii were isolated. Thirty-four ß-lactamase genes and the ISaba1-OXA-23 linkage were analyzed in these strains by polymerase chain reaction (PCR) and verified by DNA sequencing. Three kinds of ß-lactamase genes (TEM, ADC, and OXA-23) were identified, among which the sequence of strain No. 20, ADC, was different from ADC subtypes recorded by GenBank, and was identified as a new variant of ß-lactamase genes (named ADC-61 and registered in GenBank: accession No. JQ753702); all the other 19 strains were ADC-30. Eighteen strains of the OXA-23 group were all positive as indicated by detection of ISaba1-OXA-23 linkage. Gene sequencing indicated that the TEM gene was TEM-1. These results suggest that the three kinds of ß-lactamase genes identified in this study, TEM, ADC, and OXA-23, play a key role in drug resistance in this group of A. baumannii. To our knowledge, this is the first report of an emergent new mutation of the ß-lactamase gene, ADC-61, in China or abroad.

Expression of aquaporins 1 and 3 in degenerative tissue of the lumbar intervertebral disc.

Lumbar intervertebral disc degeneration is induced by multiple factors, but few studies have examined the effects of aquaporins on this process. We compared the expression levels of aquaporins 1 and 3 in normal and degenerative lumbar intervertebral discs. Fifteen normal and 15 degenerative lumbar intervertebral disc tissues were excised from lumbar burst fracture patients during orthopedic operations at the Dali College subsidiary hospital. Tissues were stained with hematoxylin-eosin and the expression levels of aquaporins 1 and 3 were measured by immunohistochemistry. Hematoxylin-eosin-staining results illustrated that the structures of the intervertebral disc tissues from the control group were clear, with distinct collagen fiber shapes and slight edema but without mucoid degeneration. Structures of the intervertebral disc tissues from the disease group were obscure and disordered with hyperplastic collagen fibers and tissues of severe inflammatory edemas with necrosis mucoid degeneration. Immunohistochemistry results demonstrated that the average absorbances of aquaporins 1 and 3 in the disease group were significantly lower than those in the control group (P < 0.01), suggesting that the reduction of aquaporins 1 and 3 may be a factor resulting in lumbar intervertebral disc degeneration.