[Overview of technical advances in the diagnosis of pulp and periapical diseases].

Pulp and periapical diseases are common and frequently occurring diseases of which diagnosis and treatment must be dealt with by the dental clinicians. The diagnostic techniques of these diseases include evaluation of pulp vitality, measurement of pulp blood circulation and analysis and judgment of root canal anatomy. With the continuous emergence of digital and imaging technologies, the correct application of these technologies in clinic will help clinicians improve their abilities in diagnosis and treatment of related diseases. The present article summarizes and reviews the progress of assistant technology for diagnosing dental pulp and periapical diseases in recent years and puts forward some suggestions for its application.

[Research and application of new techniques for early diagnosis of caries].

The present review paper summarizes the available technical methods for early detection and diagnosis of dental caries lesions, as well as their clinical application range, advantages and disadvantages. Although there are many detection systems supported by new technologies and equipments in clinical practice, current evidence suggests that careful clinical visual and inspection tests, in combination with imagological examination, are still the gold standard for the detection and diagnosis of dental caries.

[Association analysis between extracurricular physical activity and dyslipidemia among primary, middle and high school students in Guangzhou].

Objective: To investigate the prevalence of dyslipidemia, and to explore the association between extracurricular physical activity and dyslipidemia among primary, middle and high school students in Guangzhou. Methods: This cross-sectional study selected primary and middle school students in Guangzhou by the stratified cluster sampling method from March to December 2019. Physical examination and blood lipid test were performed. Information about students' basic characteristics and extracurricular physical activity was collected by questionnaire. Multivariate logistic regression analysis was used to determine the association between extracurricular physical activity and dyslipidemia in this cohort. Results: A total of 7 797 participants (mean aged (12.2±2.9) years) were included (4 194 (53.79%) boys and 3 603 (46.21%) girls]. The detection rates of high total cholesterol, high triglycerides, low high-density lipoprotein cholesterol, high low-density lipoprotein cholesterol and dyslipidemia were 12.49% (974/7 797), 6.44% (502/7 797), 6.62% (516/7 797), 11.31% (882/7 797) and 23.83% (1 858/7 797), respectively. Dyslipidemia rate was lower in the junior school students (21.39% (675/3 156)) than in primary school students (25.96% (896/3 451)) and high-school students (24.12% (287/1 190)) (P<0.001). The dyslipidemia rates of boys and girls were similar (23.15% (971/4 194) vs. 24.62% (887/3 603), P>0.05). Dyslipidemia rate was lower in students with extracurricular physical activity than in students without extracurricular physical activity (22.50% (923/4 102) vs. 25.30% (935/3 695), P<0.05). Multivariate logistic regression analysis showed that extracurricular physical activity was associated with lower risk of dyslipidemia (OR=0.88, 95%CI=0.79-0.99, P=0.033). Among all types of extracurricular physical activities, participating in extracurricular large ball game was associated with 28% lower risk among junior school students (OR=0.72, 95%CI=0.57-0.91, P=0.006). Conclusion: The prevalence of dyslipidemia is high among primary, middle and high school students in Guangzhou. Extracurricular physical activity is associated with reduced risk of dyslipidemia in this cohort.

[Research progress in non-carious cervical lesions].

Non-carious cervical lesion is a common dental disease, which not only affects the aesthetic and function of the teeth, but also leads to dentin sensitivity, pulpitis and other consequences. The main causes of lesions are abrasion, abfraction, acid erosion and so on. The treatment design should depend on the etiology, defect size, location, symptoms and presence or absence of gingival recession.

Oxygen generating biomaterial improves the function and efficacy of beta cells within a macroencapsulation device.

Tissue-engineered devices have the potential to significantly improve human health. A major impediment to the success of clinically scaled transplants, however, is insufficient oxygen transport, which leads to extensive cell death and dysfunction. To provide in situ supplementation of oxygen within a cellular implant, we developed a hydrolytically reactive oxygen generating material in the form of polydimethylsiloxane (PDMS) encapsulated solid calcium peroxide, termed OxySite. Herein, we demonstrate, for the first time, the successful implementation of this in situ oxygen-generating biomaterial to support elevated cellular function and efficacy of macroencapsulation devices for the treatment of type 1 diabetes. Under extreme hypoxic conditions, devices supplemented with OxySite exhibited substantially elevated beta cell and islet viability and function. Furthermore, the inclusion of OxySite within implanted macrodevices resulted in the significant improvement of graft efficacy and insulin production in a diabetic rodent model. Translating to human islets at elevated loading densities further validated the advantages of this material. This simple biomaterial-based approach for delivering a localized and controllable oxygen supply provides a broad and impactful platform for improving the therapeutic efficacy of cell-based approaches.

[The application of extended high frequency audiometry in detecting the early hearing loss for polycystic ovarian syndrome].

Objective:To preliminarily explore the clinical significance of extended high frequency audiometry in evaluating the early hearing loss in patients with polycystic ovarian syndrome（PCOS）. The results were statistically analyzed. Method:The hearing threshold of forty young women diagnosed as PCOS and 20 healthy controls were obtained by using conventional audiometry（0.25-8.00 kHz） and extended high frequency（10-20 kHz） pure tone audiometry. Result:The hearing thresholds of the two groups were similar at conventional frequencies of 0.25，0.50，1.00，2.00 and 4.00 kHz（P>0.05）. The hearing threshold of PCOS group at 8-20 kHz frequency was significantly higher than that of the control group, and the difference was statistically significant（P<0.05）. The expanded high-frequency detectable rate was lower in PCOS group than that in control group, especially at 16 and 18 kHz （P<0.05） and the differences were statistically significant. Conclusion:The early hearing impairment of PCOS patients starts from the extended high frequency, which is more sensitive than the conventional pure tone audiometry in the early hearing impairment assessment of PCOS patients.

3-D physiomimetic extracellular matrix hydrogels provide a supportive microenvironment for rodent and human islet culture.

Organ-on-a-chip platforms serve as cost-efficient testbeds for screening pharmaceutical agents, mimicking natural physiology, and studying disease. In the field of diabetes, the development of an islet-on-a-chip platform would have broad implications in understanding disease pathology and discovering potential therapies. Islet microphysiological systems are limited, however, by their poor cell survival and function in culture. A key factor that has been implicated in this decline is the disruption of islet-matrix interactions following isolation. Herein, we sought to recapitulate the in vivo peri-islet niche using decellularized extracellular matrix (ECM) hydrogels. Sourcing from porcine bladder, lung, and pancreas tissues, 3-D ECM hydrogels were generated, characterized, and validated using both rodent and human pancreatic islets. Optimized decellularization protocols resulted in hydrogels with distinctive viscoelastic properties that correlated to their matrix composition. The in situ 3-D encapsulation of human or rat islets within ECM hydrogels resulted in improved functional stability over standard culture conditions. Islet composition and morphology were also altered, with enhanced retention of islet-resident endothelial cells and the formation of cord-like structures or sprouts emerging from the islet spheroid. These supportive 3-D physiomimetic ECM hydrogels can be leveraged within microfluidic platforms for the long-term culture of islets.

[Analysis of deafness-related gene mutations in 23 nonsyndromic hearing impairment families in Guangxi Zhuang Autonomous Region].

Objective:To investigate the genetic characteristics of the mutations responsible for nonsyndromic hearing loss in Guangxi Zhuang Autonomous Region, and analyze the deafness-related gene mutations in nonsyndromic hearing impairment families in this region.Method:In 23 nonsyndromic hearing impairment families,66 patients or their families were enrolled as family history group and 167 patients or their families without family histiory as control group, respectively. Deafness gene mutations were determined with deafness-related gene mutations detection kits. The mutation rates among the deafness probands, the hearing impairment patients and their audibility relatives were analyzied. Whole length sequences of the deafness-related gene were detected if there was mutation by the kits, to explore Guangxi region-specific mutation-sites.Result:Common deafness-related gene mutation rate in family history group(31.82%) was higher than that in control group(11.38%), including those that in GJB2 homozygous(21.21%), SLC26A4 homozygous (9.09%), both were higher than the control group (GJB2 homozygous 5.99%, SLC26A4 homozygous 3.59%) . The rate of common deafness-related gene mutations in the deafness probands was 34.78%, in the hearing impairment patients was 30.56%, in their audibility relatives was 29.63%, all of which were higher than those in the control group. We found three rarely seen mutations, SLC26A4 IVS11+47T>C, 1548insC and GJB2 109 A>G, by detecting the whole-length sequences of the deafness-related gene.Conclusion:The results indicated that GJB2 and SLC26A4 were the most frequent mutant genes in Guangxi region. Analysis of the individual family were helpful to linkage the mutations and the deafness.

[Transnasal endoscopic surgery of communicating neoplasm outside cerebral dura mater and orbital fasciae].

Objective:This paper is intend to observe the feasibility of surgical approach with which communicating neoplasm outside cerebral dura mater and orbital fasciae was removed by transnasal endoscopic surgery.Method:Nine patients suffered from communicating neoplasm in the area of naso-orbital-cranio complex were treated with transnasal endoscopic surgery. The size of skull base bone defect was from 1.25 cm×1.13 cm to 3.25 cm×2.69 cm. No eye enucleation was done. No reconstructions of skull base and medial wall of orbital cavity were done. Iodoform gauze was packed in paranasal sinuses fourteen days. Patients with malignant tumor were treated radiation therapy and chemical therapy after surgical treatment. The degree of resection, complications of intracranial and orbital cavities, survival condition were the focus of this study.Result:The tumor were completely removed and all operations were successfully completed by trasnasal endoscopic surgery. Only one patient was required blood transfusion due to seriously bleeding from tumor during the operation. There was no orbital, intracranial, and vascular complications. The defect of bone at skull base and lamina papyracea were automatic reconstructed. Three patients have showed recurrence of neoplasm, and two of them died during two years of following up time.Conclusion:Transnasal endoscopic surgery is a safe, reliable and effective approach to treat communicating neoplasm in the area of naso-orbital-cranio complex, of which main part of tumor exists in the sinunasal cavity.

Molecular characterization and expression analysis of the ß-actin gene from the ridgetail white prawn Exopalaemon carinicauda.

Actin is a highly conserved protein that is found in all eukaryotic cells, and has been widely used as an internal control gene in gene expression studies. In this study, we cloned an actin gene (named Ecß-actin) from Exopalaemon carinicauda and determined its expression levels. The full-length cDNA of Ecß-actin was 1335 bp long, comprising a 1131-bp ORF encoding 376 amino acids, a 65-bp 5'-UTR, and a 139-bp 3'-UTR with a poly(A) tail. The A + T content was approximately 79% in the 3'-UTR of the Ecß-actin mRNA. The 3'-UTR contained two repeats of the AUUUA motif. The putative protein Ecß-actin showed high identity (97-99%) with other actins from various species. Phylogenetic analysis revealed that Ecß-actin belongs to Crustacea, although it formed a singleton sub-branch that was located a short distance from crabs and other shrimp species. Ecß- actin expression was detected in the hepatopancreas, ovary, muscle, gill, stomach, and hemocytes, and was strongly expressed in the hemocytes and ovary of E. carinicauda. Ecß-actin mRNA expression varied during ovarian development, with high levels observed at stages I and V. Therefore, caution should be taken when using the Ecß-actin gene as an endogenous control gene.

[Diffusion tensor imaging of the central auditory system in the elderly].

Objective:To evaluate the changes in the central auditory system of presbycusis by applying auditury brainstem response (ABR) and diffusion tensor imaging (DTI). Method:A total of twenty-five elderly subjects with expressed presbycusis, eight elderly subjects with normal hearing and fifteen healthy volunteers as young controls were enrolled in the study. Each participant was examined using ABR and DTI. ABR measures were obtained from all the subjects. The fractional anisotropy (FA) was measured at two brain regions of the auditory pathway-the inferior colliculus (IC) and Heschl's gyrus. Result:Higher FA values were recorded at the left side of the Heschl's gyrus in all three groups (P<0.05). There were no significant differences between the left and right side of the ABR results and FA values of inferior colliculus in the three groups (P>0.05). Aging increased ABR peak latencies, yet did not change the Ⅰ-Ⅴ interpeak latency interval. Comparing with the elderly subjects with normal hearing group, the wave Ⅴ latencies of the presbycusis group were prolonged (P<0.05). Comparing with the healthy control group, the FA values of the IC were reduced in both of the elderly subjects with normal hearing group and the presbycusis group (P<0.05). No statistically differences were observed between the presbycusis group and the elderly subjects with normal hearing group in the FA values of the IC (P>0.05). Significant differences between all groups were found in the FA values of the Heschl's gyrus, with higher values in the elderly subjects with normal hearing group than in the presbycusis group and even higher values in the healthy control group than in the elderly subjects with normal hearing group (P<0.05). Conclusion:The results indicated that the age-related microstructural changes exist in the central part of the auditory system, which are more obvious in the patients with presbycusis.

[Analysis of the SLC26A4 mutation from 230 deafness patients in Guangxi region].

Objective:To investigate the mutation characteristics of SLC26A4 gene from 230 hearing loss patients in Guangxi region.Method:Two hundred thirty patients with hearing loss were enrolled in the study. Eight mutation sites in SLC26A4 gene were tested; the types of gene mutation and the inner ear CT features of the mutationpositive patients were analyzed.Result:Among 230 deafness patients,the total mutation rate of SLC26A4 gene is 2.61%(6/230). The types of gene mutation include SLC26A4 IVS7-2A> G heterozygous in 2 case(0.87%).1226G> A homozygous in 1 cases(0.43%),IVS7-2A>G，IVS11+47T>C and 1548insC mutations in 2 cases(0.87%).Conclusion:The mutation rate of SLC26A4 gene in Guangxi region is lower than the national average level. The main mutation type in Guangxi region is SLC26A4 IVS7 2A>G. In this study, two gene mutations (SLC26A4 IVS11+47T> C and 1548insC) are firstly found, suggesting that some rare mutation types of SLC26A4 may exist in patients living in Guangxi region.

Biological changes of Enterococcus faecalis in the viable but nonculturable state.

Enterococcus faecalis may enter a viable but nonculturable (VBNC) state under adverse conditions. E. faecalis, the major bacterial species present in failed root canal treatments, is thought to survive after endodontic treatment by entering a VBNC state. In this study, we characterized the VBNC state of E. faecalis. We designed 3 different protocols to successfully induce the VBNC state. Approximately one-third of bacteria entered a VBNC state after 15-30 days, and all remained viable for at least 2 months. The morphology, glycometabolism, and adhesion capabilities of VBNC cells differed from those of E. faecalis during the exponential growth phase. Specifically, VBNC E. faecalis cells could not decompose lactose, D-mannitol, or D-sorbitol, although they were able to metabolize sucrose. Transmission electron microscopy showed that the morphology of the VBNC E. faecalis cells changed significantly; the cytoplasmic matrix was unevenly condensed and the overall morphology of the cells became irregular, but the cell membranes remained intact. Although the adhesion ability of the bacteria decreased, VBNC E. faecalis could still adhere to collagen fiber type I and tooth dentine. The persistence of this adhesion ability may be important in the virulence of VBNC E. faecalis.

Exploration of the mechanisms of biofilm formation by Enterococcus faecalis in glucose starvation environments.

BACKGROUND: Enterococcus faecalis is the most common single species present in teeth after failed root canal therapy. This is mainly due to its ability to maintain viability for a long time in filled root canals where nutrients are normally sparse. The aim of this study was to explore the mechanism of E. faecalis survival and biofilm formation in glucose-starved environments. METHODS: Enterococcus faecalis ATCC 33186 was inoculated in energy starvation media for biofilm formation. Confocal laser scanning microscopy and fluorescent DNA-binding agents were employed to assess biofilm-forming ability. The physiochemical properties of the biofilm cell wall were investigated by measuring the hydrophobicity, extracellular polysaccharide and ATPase activity. The expression of stress and virulence genes was quantified by real-time quantitative polymerase chain reaction. RESULTS: The ability for biofilm formation decreased with a decreasing concentration of glucose. The cell surface hydrophobicity increased dramatically with decreasing glucose concentration. Water-soluble exopolysaccharide (WSE) synthesis decreased in glucose starvation media, whereas water-insoluble exopolysaccharide (WIE) synthesis increased. A marked decrease in ATPase activity was observed only in a no glucose medium. In addition, transcription of ace, fsrB and gelE genes increased under glucose starvation stress while atpE, salB and esp genes were down-regulated. CONCLUSIONS: Enterococcus faecalis survival and biofilm formation under glucose starvation stress may be attributed to an increase in cell-surface hydrophobicity and additionally to the up-regulation of some genes involved in stress response and biofilm formation. These characteristics may explain why E. faecalis can maintain viability for a long time in an energy-starved environment and why it is frequently isolated from persistently infected root canals.

Functionalized bio-artifact fabricated via selective slurry extrusion. Part 2: Fabrication of ceramic dental crown.

Functionalized ceramic dental crown was successfully fabricated through selective slurry extrusion (SSE) based technique of solid freeform fabrication (also known as rapid prototyping). After sintering, the decomposed tourmaline powders were embedded in ZrO2 matrix. The far infrared emission properties of the ceramic dental crown were improved due to the increase of the numbers of infrared active bonds from tourmaline. This new dental restoration process presents potential to provide dental patients with functionalized artificial teeth, which benefits the body health by the way of emitting far infrared rays in ambient temperatures.

Accumulation and elimination of enrofloxacin and its metabolite ciprofloxacin in the ridgetail white prawn Exopalaemon carinicauda following medicated feed and bath administration.

Accumulation and elimination of enrofloxacin and its metabolite ciprofloxacin were evaluated in Exopalaemon carinicauda following medicated feed at dose of 10 mg/kg weight body per day for five consecutive days and 10 mg/L bath for five consecutive days at 18 °C. At different times, nine ridgetail white prawns were randomly selected from the tank and sampled after the last medicated feed or bath administration. The concentration of enrofloxacin and ciprofloxacin in the main tissues (hepatopancreas, muscle, gill, and ovary) was detected by HPLC. The results showed that the maximum concentrations of enrofloxacin were 3.408 ± 0.245, 0.554 ± 0.088, 0.789 ± 0.074, and 0.714 ± 0.123 µg/g for hepatopancreas, muscle, gill, and ovary, respectively, at 1 day after the last medicated feed treatment. The enrofloxacin concentrations were 2.389 ± 0.484, 0.656 ± 0.012, 0.951 ± 0.144, and 3.107 ± 0.721 µg/g in hepatopancreas, muscle, gill, and ovary, respectively, at 1 day after the last bath administration. Ciprofloxacin could be detected in hepatopancreas, muscle, gill, and ovary. However, the concentrations of ciprofloxacin were much lower in comparison with that of enrofloxacin in various tissues. The concentrations of enrofloxacin plus ciprofloxacin in hepatopancreas, muscle, gill, and ovary followed an eliminating pattern during the sampling time after the two routes of administration. Based on data derived from this study, to avoid the enrofloxacin and ciprofloxacin residue in E. carinicauda, it should take at least 20 and 25 days to wash out the drug from the tissues after the last medicated feed and bath administration with enrofloxacin, respectively. These results helped the Chinese fishery department to lay down the current guidelines on enrofloxacin plus ciprofloxacin withdrawal periods for farmed shrimp.

Chicken domestication: an updated perspective based on mitochondrial genomes.

Domestic chickens (Gallus gallus domesticus) fulfill various roles ranging from food and entertainment to religion and ornamentation. To survey its genetic diversity and trace the history of domestication, we investigated a total of 4938 mitochondrial DNA (mtDNA) fragments including 2843 previously published and 2095 de novo units from 2044 domestic chickens and 51 red junglefowl (Gallus gallus). To obtain the highest possible level of molecular resolution, 50 representative samples were further selected for total mtDNA genome sequencing. A fine-gained mtDNA phylogeny was investigated by defining haplogroups A-I and W-Z. Common haplogroups A-G were shared by domestic chickens and red junglefowl. Rare haplogroups H-I and W-Z were specific to domestic chickens and red junglefowl, respectively. We re-evaluated the global mtDNA profiles of chickens. The geographic distribution for each of major haplogroups was examined. Our results revealed new complexities of history in chicken domestication because in the phylogeny lineages from the red junglefowl were mingled with those of the domestic chickens. Several local domestication events in South Asia, Southwest China and Southeast Asia were identified. The assessment of chicken mtDNA data also facilitated our understanding about the Austronesian settlement in the Pacific.

Preliminary study of the presence and association of bacteria and archaea in teeth with apical periodontitis.

AIM: To investigate, by reverse transcription polymerase chain reaction (RT-PCR), the presence and association of bacteria and archaea in primary and secondary root canal infections. METHODOLOGY: A total of 77 root canal samples from 77 Chinese patients, 42 with necrotic pulp tissues (primary infection) and 35 with failed prior conventional root canal treatment (secondary infection), aseptically exposed at the first patient visit, were studied. Total RNA was isolated directly from each sample, and 16S rRNA gene-based RT-PCR assays were used to determine the presence of bacteria and archaea, respectively. RESULTS: Bacteria were detected in 39/42 (93%) of root canal samples from teeth with primary infections, and archaea in 16/42 (38%). In the cases diagnosed as secondary root-infected canals, bacteria were detected in 30/35 (86%), whilst archaea were detected in 6/35 (17%) of cases. Amongst the canals, which were positive for bacteria, archaea were always found in combination with bacteria. The incidence of symptomatic cases positive for both bacteria and archaea (16/22, 73%) were significantly higher than those positive for bacteria alone (21/47, 45%) (P < 0.05). CONCLUSIONS: This study confirms the presence of archaea in root canal infections and further implicates them in an association with clinical symptoms. The nature of this association requires further study.