[Objective] To resolve the ambiguities of HLA genotyping generated by next generation sequencing (NGS) using nanopore sequencing technology. [Methods] A total of 38 samples with ambiguous HLA genotyping by NGS in our laboratory were collected, and HLA-A, -B, -C, -DRB1, -DRB3/4/5, -DQA1, -DQB1, -DPA1 and -DPB1 loci in these samples were amplified using primers in the same commercial NGS HLA genotyping kit, then subjected to third-generation library construction, and sequenced on the nanopore sequencer. The sequencing data were converted into Fastq files and analyzed by software, and the genotypes of 11 HLA loci were obtained. The ambiguities were counted directly. [Results] The high-resolution genotyping at the second domain of 11 HLA loci of 38 samples using the third generation sequencing (TGS) were consistent with the results of the NGS method at a rate of 100%. The genotypes for the HLA-A, -B, -C, -DRB3, -DRB4, -DQA1 and -DPA1 loci by TGS were all only one result, and the discrimination rate for ambiguities of the HLA-A, -B, -C, and -DQA1 loci (all caused by the difficulty in phasing due to the short NGS read length) was 100%. Among the HLA-DRB1, -DRB5, -DQB1 and -DPB1 loci, the discrimination rate of TGS for the ambiguities caused by non-amplification of exon 1 was 0% and by the short NGS read length was 100%. [Conclusion] Nanopore technology was used to identify the ambiguities of 11 HLA loci in this study, and the ambiguities caused by the short read length disadvantage of the NGS method could be solved effectively and the accuracy of HLA genotyping would be improved.

Objective To analyze the scanning parameters and radiation dose characteristics of pediatric CT examinations in Jiangxi Province, China, and to provide a basis for optimizing radiation protection in children. Methods The data of 1021 CT scans in children aged 0-15 years were collected from seven hospitals in Jiangxi Province, including one provincial hospital, four municipal hospitals, and two county-level hospitals. The data consisted of 405 head scans, 352 chest scans, and 264 abdominal scans. The scanning parameters kV, mAs, and scan length as well as the dose metrics weighted CT dose index and dose length product (DLP) were analyzed. Differences across age groups, anatomical regions, and hospitals were compared using one-way analysis of variance, and the results were compared with domestic and foreign studies. Results There were significant differences in scanning parameters and radiation doses among children of different age groups in CT examinations, and the differences between hospitals were also significant. The chest mAs and DLP in Hospital E were significantly higher than those in Hospital A, and the abdominal DLP in Hospital D was 4.3 times that of Hospital A. Compared with domestic and foreign studies, the DLP values of various anatomical regions in the < 1 year group were generally higher in the present study. The abdominal DLP in the < 1 year group (232.4 mGy·cm) was 3.3 times that in Tianjin. The head DLP in the 1-5 year group was higher than those in Germany and the United States. The chest DLP of the 11-15 year group was higher than that in Germany but lower than that in Henan Province. Conclusion There are significant differences in radiation doses received by children during CT examination in Jiangxi Province by age, anatomical region, and hospital, with some metrics exceeding domestic and international levels. Recommendations include optimizing scanning parameters (e.g., reducing mA/kV and adopting automatic exposure control technology), standardizing scan ranges, and establishing local diagnostic reference levels to mitigate radiation risks.

Objective:To investigate the effects of macrophage(Mφ)polarization on the cementogenic differentiation of human perio-dontal ligament stem cells(hPDLSCs)and the underlying mechanism.Methods:Human monocytic THP-1 cells were induced to M0,M1 and M2 Mφ subsets,then RPM1 1640 medium or supernatants of different Mφ phenotypes were mixed with an equal volume of ce-mentoblastic induction medium to generate conditioned mediums(CMs),and termed as CM-Control,CM-M0,CM-M1 and CM-M2,respectively.hPDLSCs were cultured with different CMs,and the hPDLSCs sheets were then wrapped around treated dentin matrix(TDM)to generate cell sheet/dentin complexes.The complexes were subcutaneously implanted into nude mice.The cementum-like tissue formation was evaluated by HE staining,immunofluorescent staining(IMF)and qRT-PCR were used to detect the expression level of cementogenic differentiation-related markers bone sialoprotein(BSP),cementum attachment protein(CAP)and cementum pro-tein-1(CEMP-1),oxidant-antioxidant system-related markers superoxide dismutase 1(SOD1)and nuclear factor erythroid 2-related factor 2(NRF2),mitophagy-related markers PTEN induced putative kinase 1(PINK1)and microtubule asso ciated proteins 1A/1B light chain 3(LC3).Results:In vivo,CM-M2-treated hPDLSCs(CM-M2)group formed more cementum-like tissues and expressed higher protein levels of CAP,CEMP-1,SOD1,PINK1 and LC3 than that in other groups.In vitro tests showed that,compared with CM-Control group,hPDLSCs incubated with CM-M2 increased the levels of BSP(P＜0.01),CAP(P＜0.001),CEMP-1(P＜0.01)and SOD1(P＜0.05),while no statistically significant difference was detected for NRF2(P＞0.05),and increasedthe expression of PINK1(P＜0.05).Conclusion:M2 Mφ regulate the cementogenic differentiation of hPDLSCs possibly via modulating oxidant-antioxidant system and mitophagy.

Objective:To prepare PLGA electrospinning membranes doped with hollow mesoporous silica nanoparticles loaded with metformin and investigate their biological properties.Methods:PLGA(Control group)and PLGA/HMSN/Met electrospun membranes(Experimental group)were prepared by electrospinning technology.The microscopic morphology of the 2 groups of electrospun mem-branes was observed by SEM.The hydrophilicity,elemental composition and in vitro drug release were detected by contact angle meas-urement,EDS,and drug release test,respectively.SEM and laser scanning confocal microscope(LSCM)were used to observe the growth of periodontal ligament stem cells(PDLSCs)on the 2 groups of electrospun membranes,and CCK-8 assay was used to detect the cell proliferation.Results:Both electrospun membranes had extracellular matrix(ECM)-like fiber structures.The PLGA/HMSN/Met electrospun membranes could slowly release Met for up to 35 days,and the hydrophilicity of PLGA membranes was improved by HMSN-Met doped.The composite electrospun membranes had good cell biocompatibility in vitro,and could promote cell proliferation.Conclu-sion:Modification of PLGA with HMSN-Met can improve the hydrophilicity of PLGA electrospun membranes,continuously release Met,and have good cell biocompatibility.

Objective:To analyze the sequence of a novel HLA- DPB1 allele in an individual. Methods:A individual identified from the database of blood donors for matched platelet transfusion at the Blood Center of Zhejiang Province in May 2022 was selected as the study subject. HLA genotype of the individual was determined by next-generation sequencing (NGS) on an Ion Torrent S5 platform. The sequence of the HLA- DPB1 locus was also determined by NGS on an Illumina Miseq platform and third generation sequencing using Oxford Nanopore MinION. This study was approved by Medical Ethics Committee of the Blood Center of Zhejiang Province (Ethics No. 2021-001). Results:A novel HLA- DPB1*02 allele was identified in the specimen, for which the closest genotype was HLA- DPB1*02: new, 17: 01: 01G, with the variant located in exon 3. Meanwhile, the NGS also revealed a novel HLA- DPB1*17 allele, with the closest genotype being HLA- DPB1*02: 01: 02G, 17: new. Both the HLA- DPB1*17: 01: 01: 01 and novel HLA- DPB1*02 alleles were identified by third-generation sequencing. Compared with the HLA- DPB1*02: 01: 02: 01 allele, the novel allele had a G>A variation at position 369 in the exon 3, which did not result in amino acid change. Conclusion:A novel HLA- DPB1 allele has been identified and validated by both NGS and TGS, which has been named as HLA- DPB1*02: 01: 69 by the World Health Organization Committee on Nomenclature of Factors of the HLA System.

Due to the limitations of eruption time and space, third molars (M3s) are often impacted and induce a variety of oral diseases, bringing adverse effects on the health of their adjacent second molars (M2s). For a long time, a large number of studies have focused on the harm of impacted M3s (I-M3s) to the health of their adjacent teeth, while less attention has been paid to nonimpacted M3s (N-M3s) that have already erupted. In recent years, however, a growing number of studies and evidences have shown that the existence of N-M3s is also an important risk factor for various diseases of their adjacent teeth, whose hazard has not been taken seriously by dentists and patients. Based on the latest results of both domestic and international researches as well as our group, this review summarizes and explains the effects of N-M3s on the periodontal homeostasis and periodontal health of adjacent M2s, so as to provide reference for clinical decision-making of N-M3s and the healthy maintenance of their adjacent teeth.

Objective:To investigate the effects of Porphyromonas gingivalis derived outer membrane vesicles (Pg OMV) on osteoclast differentiation of macrophages and its underlying mechanisms. Methods:The morphology and the size distribution of Pg OMV were analyzed by transmission electron microscopy and nanoparticle tracing analysis, respectively. The osteoclast precursors were treated with 1, 3 and 10 mg/L Pg OMV (1, 3 and 10 mg/L OMV treatment group) or phosphate buffer solution (PBS)(control group). The formation of osteoclasts was analyzed by tartrate-resistant acid phosphase (TRAP) staining and F-actin staining and real-time quantitative PCR (RT-qPCR) were used to detect the expression of Fos and matrix metallopeptidase 9 (MMP9). Polymyxin B (PMB) was used to block lipopolysaccharide (LPS) and then Pg OMV was used to treat osteoclast precursor (PMB-OMV treatment group), and OMV treatment group was used as control. TRAP and F-actin staining were used to observe the formation of osteoclasts and actin rings. The effect of Pg OMV on the expression of Toll-like receptor (TLR) 2 and TLR4 in preosteoclasts was detected by Western blotting. The osteoclast precursors were pretreated with 10, 50, 100 and 200 μmol/L C29, an inhibitor of TLR2, and then treated with Pg OMV(OMV+10, 50, 100 and 200 μmol/L C29 treatment group) and OMV treatment group without C29 pretreatment was control. TRAP and F-actin staining were used to observe the formation of osteoclasts and actin rings. The osteoclast precursor cells were treated with OMV (OMV treatment group) and OMV incubated with PMB (PMB-OMV treatment group) and the expression of TLR2 in osteoclast precursor was detected by Western blotting.Results:Pg OMV showed classical vesicular structures, and the average particle size of Pg OMV were 179.2 nm. A large number of actin rings were observed in the 3 and 10 mg/L OMV treatment groups. The percentages of TRAP-positive osteoclast area in 3 mg/L OMV treatment group [(22.6±2.1)%] and 10 mg/L OMV treatment group [(32.0±2.3)%] were significantly increased compared with control group [(4.9±0.5)%] ( P<0.001). Compared with the control group (1.000±0.029), the mRNA relative expression of Fos in 3 mg/L OMV treatment group (1.491±0.114) and 10 mg/L OMV treatment group (1.726±0.254) was significantly increased ( P=0.013, P=0.001). Compared with the control group (1.007±0.148), the mRNA relative expression of MMP9 in the group of 10 mg/L OMV (2.232±0.097) was significantly increased ( P<0.001). Actin ring formation was less in PMB-OMV treatment groups than in OMV treatment groups. The proportion of TRAP-positive osteoclasts area [(14.8±3.8)%] in PMB-OMV treatment group was significantly lower than OMV treatment group [(31.5±6.7) %] ( P=0.004). The relative expression of TLR2 in OMV treatment group (1.359±0.134) was significantly higher than that in the control group (1.000±0.000) ( t=4.62, P=0.044). Compared with the OMV treatment group [(29.4±1.7)%], 50, 100 and 200 μmol/L C29 significantly decreased the formation of osteoclasts [(24.0±1.7)%, (18.5±2.1)%, (9.1±1.3) %] ( P=0.026, P<0.001, P<0.001). TLR2 protein expression in PMB-OMV group (0.780±0.046) was significantly lower than that in OMV group (1.000±0.000)( t=8.32, P=0.001). Conclusions:Pg OMV can promote osteoclast differentiation by carrying LPS, TLR2 plays an important role in Pg OMV mediated osteoclast differentiation.

Chronic and progressive destruction/damage of the periodontal tissues resulted from periodontitis is the leading cause of tooth loss in adults. Traditional periodontal therapies such as scaling and root planning or flap surgery have demonstrated effective in controlling local inflammation and in suppressing/arresting the disease progression of periodontitis. However, those infection control measures cannot help to regenerate lost periodontal tissues to a statistically or clinically significant degree. Although some successes regarding the reduction of the intrabony defect and maintenance of the periodontal homeostasis have been achieved in periodontal regenerative procedures, comprising but not limited to guided tissue regeneration (GTR) or bone grafting technique, the restorative effectiveness of the architecture and function of the lost or injured tissues is far from our clinical expectation. The use of the concept, technique, and method of tissue engineering for periodontal regeneration is a hotspot and animal studies have shown interesting outcomes in terms of functional regeneration of lost/damaged support tissues in the periodontium, including alveolar bone, periodontal ligament, and cementum. However, numerous issues need to be addressed before those regenerative approaches can be responsibly transformed to novel clinical therapies. Recently, paradigm that induces homing of host stem cells to site of the periodontium and encourage the body's innate capability to repair is a new research field termed endogenous regeneration. Given that endogenous regenerative technique avoids ex- vivo cell culture and transplantation, it should be relatively easier to be used in the treatment of clinical patients. Due to the limited oral microenvironment and harsh periodontal local condition for tissue regeneration, as well as poor understanding of periodontal regenerative biology, there is still a long way ahead to explore new effective, practical, and economical therapies to save and protect natural tooth and for combating highly prevalent periodontal disease.

Objective:To investigate the characteristics of extracellular matrix vesicle mimetics prepared by mechanical extrusion and their effects on the cell viability and osteogenic differentiation potential of human periodontal ligament stem cells (PDLSC).Methods:PDLSC derived extracellular matrix vesicles were prepared by collagenase digestion, while the cell derived vesicle mimetics were simulated by mechanical extrusion. The obtained extracellular matrix vesicles and parental cell derived vesicle mimetics were divided into 4 groups: matrix vesicles derived from PDLSC cultured in basic medium for 7 days (PDLSC matrix vesicles, MVs), vesicle mimetics derived from PDLSC cultured in basic medium for 7 days (PDLSC vesicle mimetics, CVMs), matrix vesicles derived from PDLSC cultured in osteogenic inducing medium for 7 days (osteogenic-induced PDLSC matrix vesicles, O-MVs) and vesicle mimetics derived from PDLSC cultured in osteogenic inducing medium for 7 days (osteogenic-induced PDLSC vesicle mimetics, O-CVMs). Vesicles morphologies and sizes were observed by transmission electron microscopy and nanoparticle tracking analysis. Vesicles uptake was detected by immunofluorescence. With PDLSC as the control group, the effects of vesicles on the viability of PDLSC were detected by cell activity assay (cell counting kit-8), and the effects of vesicles on the osteogenic differentiation potential of PDLSC were detected by alizarin red staining and Western blotting.Results:Vesicles in MVs, O-MVs, CVMs and O-CVMs were all observed with a round structure (size 50-250 nm), and could be taken up by PDLSC without affecting the cell viability. Under osteogenic inducing conditions, PDLSC incubated with O-MVs or O-CVMs could produce more mineralized nodules than those in the control group (PDLSC). MVs, O-MVs, CVMs and O-CVMs could promote the expression of osteogenic-related proteins in PDLSC. PDLSC in group O-CVMs showed significant higher expressions of osteogenic-related proteins, including alkaline phosphatase (ALP) (1.571±0.348), osteopontin (OPN) (1.827±0.627) and osteocalcin (OCN) (1.798±0.537) compared to MVs (ALP: 1.156±0.170, OPN: 1.260±0.293, OCN: 1.286±0.302) ( P<0.05). Compared to CMVs-incubated PDLSC, O-CVMs-incubated PDLSC expressed more Runt-related transcription factor 2 (1.632±0.455 vs 1.176±0.128) and OPN (1.827±0.627 vs 1.428±0.427) ( P<0.05). Moreover, there was no significant difference in the expression levels of osteoblast-related proteins in PDLSC cultured with MVs, O-MVs and CVMs ( P>0.05). Conclusions:The vesicle mimetics prepared by mechanical extrusion method are similar in shape and size to the extracellular matrix vesicles. MVs, O-MVs, CVMs and O-CVMs do not affect the cell viability of PDLSC, and can promote the osteogenic differentiation potential of PDLSC to a certain extent.

The oral cavity is the second largest reservoir of microorganisms in the human body, containing more than 700 species. Periodontal microorganisms are an important part of oral microorganisms. Plaque biofilm, the initiator of periodontal disease, contains an abundance of oral microorganisms. The special complex anatomy of the periodontium allows for a higher abundance of the periodontal microbiota. There are growing evidences show that the periodontal microbiota is not only closely associated with oral diseases, but also plays an important role in mouth-brain interactions. Dysbiosis of the periodontal microbiota may facilitate the progression of neurodegenerative diseases including Alzheimer disease, Parkinson disease, and multiple sclerosis. Here, this paper reviews the bidirectional role of periodontal microbiota between the oral cavity and the brain, that is, the bridge effect of periodontal microbiota involved in the interaction between the two diseases, enumerates the epidemiological and biological evidences that dysregulation of the periodontal microbiota induces and exacerbates neurodegenerative diseases, and analyzes their possible mechanisms. The positive implications of periodontal microbial homeostasis in the prevention and treatment of neurodegenerative diseases are described with the aim of providing new ideas and insights into the pathogenesis and therapeutic approaches for neurodegenerative diseases.