Objective To investigate the effects of miR-34a on proliferation and osteogenic differentiation of human periodontal stem cells.Methods Twenty healthy teeth that needed to be extracted for orthodontic treatment were collected.Human periodontal stem cells(hPDLSCs)were isolated and cultured in vitro,and miR-34a mimetics were constructed and transfected into hPDLSCs.The experimental groups were subsequently categorized into the mimics group(miR-34a overexpression group)and the mimics-NC group(control group without load).The transfection efficiency was assessed using real-time fluorescence quantitative PCR(qRT-PCR),while CCK-8 assays were used to evaluate the proliferation capacity of hPDLSCs post-transfection.Osteogenic differentiation of miR-34a-transfected hPDLSCs was induced,with samples being collected at day 0 and day 14 after the osteogenic induction.The expression level of Runx2-associated transcription factor 2(Runx2)was quantified via qRT-PCR,protein levels of Runx2-associated proteins were analyzed through Western blot,and mineralized nodule formation was examined using alizarin red staining.Results The expression level of miR-34a in the mimics group was significantly higher than that in the mimics-NC group(P<0.05).There was no significant difference in the value-added rate between the mimics group and the mimics-NC group on days 1～5(P>0.05),and the value-added rate between the mimics group and the mimics-NC group was significantly lower than that between the mimics-NC group and the mimics-NC group on days 5～11,and the difference was statistically significant.After the osteogenic induction,the mRNA expression level of Runx2 in the mimics group was higher than that in the mimics-NC group(P<0.05),and the expression level of Runx2 protein in the mimics group was also higher than that in the mimics-NC group(P<0.05),and there were more mineralized nodules in the mimics group than in the mimics-NC group after 14 days of osteogenic induction.Conclusion Under in vitro conditions,miR-34a inhibits the proliferative activity of hPDLSCs and promotes the osteogenic differentiation of human periodontal ligament stem cells.

Nocardia is a Gram-positive pathogen responsible for causing dairy mastitis,which leads to purulent granulomatous lesions in mammary tissue and can significantly impact the dairy indus-try,resulting in substantial economic losses.To develop a rapid and accurate diagnostic method for detecting Nocardia of bovine origin,a conserved sequence of the 16S rRNA gene from Nocardia was selected from the NCBI database.Based on this sequence,a pair of primers and a TaqMan fluo-rescent quantitative probe were designed.The validation of the TaqMan fluorescence quantitative PCR(qPCR)method found in this study showed that the Ctvalue had a good linear relationship with recombinant plasmid concentrations ranging from 1×1010 to 1×102 copies/μL,with a regres-sion equation of y=-3.536x+43.78,a correlation coefficient(R2)of 0.997 5,a slope of-3.536,and an amplification efficiency(E)of 91％(where 90％＜E＜110％).The specificity was strong,with no cross-reactions with other pathogens.The standard curve had a high sensitivity with a low-er detection limit of 1 × 102 copies/μL,it was 100-fold higher than conventional PCR.The repeatability of the standard curve was also good.Both intra-and inter-group coefficients of varia-tion were below 2％.Using this method,234 milk samples and 80 environmental samples were tested using this method,respectively,with a positive detection rate of 27.07％,whereas conven-tional PCR had a positive detection rate of 19.43％,indicating that this method was more sensitive compared to conventional PCR.The fluorescent quantitative PCR detection method established in this study provides an effective means for the clinical detection of Nocardia in dairy cows.

A case report of adult skeletal class Ⅲ patient with high angle open bite is presented in this article.The patient underwent extraction of bilateral mandibular first molars and straightening the third molars,open bite was resolved,normal over bite,over jet and good occlusion were established.

Objective:To analyze the predictive factors associated with late-onset sepsis(LOS) in very low birth weight infants,and to develop a risk prediction score scale applicable to these infants three days postnatal.This will provide valuable insights for early diagnosis and timely intervention.Methods:Very low birth weight infants admitted to the Children's Hospital of Fudan University from January 1,2022,to June 30,2024,were selected as research subjects.These infants were categorized into two groups:the LOS group and the non-LOS group,based on whether they developed LOS.LASSO regression analysis,alongside univariate and multivariate regression analyses,was employed to identify predictive factors for LOS in this population.A Logistic model was constructed using the optimal combination of predictive variables,and a risk assessment scale was subsequently developed.The prediction performance of the model was evaluated using the Hosmer-Lemeshow chi-square test and the receiver operating characteristic curve.Results:A total of 444 cases of very low birth weight infants were included,of which 185 had LOS and 259 did not.After screening the variables,seven independent factors were included into the model:birth weight,gestational age,tracheal intubation,abnormal skin color,abdominal distension,elevated C-reactive protein levels,and right hand perfusion index.A predictive scoring scale was developed based on the regression coefficients of each variable,with corresponding risk scores assigned as follows:1,4,3,2,1,1,and 2; a score of ≥3.5 indicated high-risk groups.The Hosmer-Lemeshow test results demonstrated that χ2 = 7.602( P = 0.473).The area under the receiver operating characteristic curve was 0.792 ( P<0.001),with a sensitivity of 73.5% and specificity of 71.0%. Conclusion:The risk score scale developed in this study exhibits significant predictive capability,providing valuable insights for clinical medical personnel to assess the risk of LOS in very low birth weight infants during the early postnatal period.

Nocardia is a Gram-positive pathogen responsible for causing dairy mastitis,which leads to purulent granulomatous lesions in mammary tissue and can significantly impact the dairy indus-try,resulting in substantial economic losses.To develop a rapid and accurate diagnostic method for detecting Nocardia of bovine origin,a conserved sequence of the 16S rRNA gene from Nocardia was selected from the NCBI database.Based on this sequence,a pair of primers and a TaqMan fluo-rescent quantitative probe were designed.The validation of the TaqMan fluorescence quantitative PCR(qPCR)method found in this study showed that the Ctvalue had a good linear relationship with recombinant plasmid concentrations ranging from 1×1010 to 1×102 copies/μL,with a regres-sion equation of y=-3.536x+43.78,a correlation coefficient(R2)of 0.997 5,a slope of-3.536,and an amplification efficiency(E)of 91％(where 90％＜E＜110％).The specificity was strong,with no cross-reactions with other pathogens.The standard curve had a high sensitivity with a low-er detection limit of 1 × 102 copies/μL,it was 100-fold higher than conventional PCR.The repeatability of the standard curve was also good.Both intra-and inter-group coefficients of varia-tion were below 2％.Using this method,234 milk samples and 80 environmental samples were tested using this method,respectively,with a positive detection rate of 27.07％,whereas conven-tional PCR had a positive detection rate of 19.43％,indicating that this method was more sensitive compared to conventional PCR.The fluorescent quantitative PCR detection method established in this study provides an effective means for the clinical detection of Nocardia in dairy cows.

Objective:To analyze the predictive factors associated with late-onset sepsis(LOS) in very low birth weight infants,and to develop a risk prediction score scale applicable to these infants three days postnatal.This will provide valuable insights for early diagnosis and timely intervention.Methods:Very low birth weight infants admitted to the Children's Hospital of Fudan University from January 1,2022,to June 30,2024,were selected as research subjects.These infants were categorized into two groups:the LOS group and the non-LOS group,based on whether they developed LOS.LASSO regression analysis,alongside univariate and multivariate regression analyses,was employed to identify predictive factors for LOS in this population.A Logistic model was constructed using the optimal combination of predictive variables,and a risk assessment scale was subsequently developed.The prediction performance of the model was evaluated using the Hosmer-Lemeshow chi-square test and the receiver operating characteristic curve.Results:A total of 444 cases of very low birth weight infants were included,of which 185 had LOS and 259 did not.After screening the variables,seven independent factors were included into the model:birth weight,gestational age,tracheal intubation,abnormal skin color,abdominal distension,elevated C-reactive protein levels,and right hand perfusion index.A predictive scoring scale was developed based on the regression coefficients of each variable,with corresponding risk scores assigned as follows:1,4,3,2,1,1,and 2; a score of ≥3.5 indicated high-risk groups.The Hosmer-Lemeshow test results demonstrated that χ2 = 7.602( P = 0.473).The area under the receiver operating characteristic curve was 0.792 ( P<0.001),with a sensitivity of 73.5% and specificity of 71.0%. Conclusion:The risk score scale developed in this study exhibits significant predictive capability,providing valuable insights for clinical medical personnel to assess the risk of LOS in very low birth weight infants during the early postnatal period.

A case report of adult skeletal class Ⅲ patient with high angle open bite is presented in this article.The patient underwent extraction of bilateral mandibular first molars and straightening the third molars,open bite was resolved,normal over bite,over jet and good occlusion were established.

Objective:To construct the chimeric virus ChimZIKV of Japanese encephalitis virus and Zika virus and evaluate whether the chimeric virus can be developed into a candidate vaccine strain against Zika virus.Methods:The infectious clone of chimeric virus ChimZIKV was constructed by replacement the prM/E of Japanese encephalitis virus vaccine strain with that of Zika virus. RNA of chimeric virus ChimZIKV had been transcribed in vitro and was electro-transfected into BHK-21 cells to rescue chimeric virus. Afterward, the chimeric virus was identified by plaque assay, immunofluorescence and gene sequencing. The growth was shown by the growth curve. The neurobirulence, viremia, neutralizing antibody production and immune protective effect of chimeric virus were tested by animal experiments.Results:The result of restriction enzyme digestion showed that the infectious clone of chimeric virus was successfully constructed, and the immunofluorescence assay and sequencing showed that chimeric virus ChimZIKV was successfully rescued. The cell proliferation activity test showed that the cell proliferation activity of the chimeric virus infected group was higher than that of the infected group. The result of animal experiments showed that chimeric virus showed very low neurovirulence to mice and suckling mice, and the result of viremia showed that chimeric virus had no obvious viremia in mice. Plaque reduction neutralization test (PRNT) showed 100% positive conversion of neutralizing antibody in sera of immunized mice, and the highest neutralizing antibody titer (GMT=85) was seen in the third week. The immune protection experiment showed that the protection rate against JE/ZIKV(MR766) was 30%.Conclusions:This study showed that the chimeric virus ChimZIKV is immunogenic and with low neurovirulence, and it may be further developed as a candidate vaccine strain against Zika virus.

Streptococcus mutans (S. mutans) is generally regarded as a major contributor to dental caries because of its ability to synthesize extracellular polysaccharides (EPS) that aid in the formation of plaque biofilm. The VicRKX system of S. mutans plays an important role in biofilm formation. The aim of this study was to investigate the effects of vicK gene on specific characteristics of EPS in S. mutans biofilm. We constructed single-species biofilms formed by different mutants of vicK gene. Production and distribution of EPS were detected through atomic force microscopy, scanning electron microscopy and confocal laser scanning microscopy. Microcosmic structures of EPS were analyzed by gel permeation chromatography and gas chromatography-mass spectrometry. Cariogenicity of the vicK mutant was assessed in a specific pathogen-free rat model. Transcriptional levels of cariogenicity-associated genes were confirmed by quantitative real-time polymerase chain reaction. The results showed that deletion of vicK gene suppressed biofilm formation as well as EPS production, and EPS were synthesized mostly around the cells. Molecular weight and monosaccharide components underwent evident alterations. Biofilms formed in vivo were sparse and contributed a decreased degree of caries. Moreover, expressional levels of genes related to EPS synthesis were down-regulated, except for gtfB. Our report demonstrates that vicK gene enhances biofilm formation and subsequent caries development. And this may due to its regulations on EPS metabolism, like synthesis or microcosmic features of EPS. This study suggests that vicK gene and EPS can be considered as promising targets to modulate dental caries.
Animals ; Biofilms ; Dental Caries ; Dental Plaque ; Rats ; Streptococcus mutans/genetics*

Objective: To investigate the effects of sodium butyrate on intestinal barrier of the severe scald mice and the related mechanism. Methods: Eighteen C57BL/6 female mice, aged eight to twelve weeks, were divided into sham scald group, pure scald group, and scald+ sodium butyrate group according to random number table, with 6 mice in each group. Back of each mouse in pure scald group and scald+ sodium butyrate group were immersed into 90 ℃ water for 9 s, causing full-thickness scald of 30% total body surface area, while back of each mouse in sham scald group were immersed into 37 ℃ water for 9 s, causing sham injury. All of the mice in 3 groups were intraperitoneally injected with 1 mL sterile lactated Ringer′s solution immediately after injury. Besides, mice in scald+ sodium butyrate group were intraperitoneally injected with 300 mg/kg sodium butyrate at 30 min before injury and immediately after injury, while mice in sham scald group and pure scald group were intraperitoneally injected with the same volume of sterile phosphate buffer solution. At post injury hour (PIH) 24, portal vein of mice in 3 groups was harvested, intestinal permeability was measured by fluorescin isothiocyanate-dextran fluorescence probe tracing method, then lileal tissue of mice in 3 groups was harvested, protein expressions of zonula occludens l (ZO-1), occludin, claudin-1, claudin-2, nucleotide-binding oligomerization domain-containing protein-like receptor family pyrin domain containing 3 (NLRP3), interleukin-1β (IL-1β), and IL-18 were detected by Western blotting, and distribution of ZO-1 in intestinal mucosa was observed by indirect immunofluorescence. Data were processed with one-way analysis of variance, least-significant difference test, and Bonferroni correction. Results: (1) At PIH 24, the intestinal permeability of mice in sham scald group, pure scald group, and scald+ sodium butyrate group was 0.88±0.19, 2.62±0.48, 1.23±0.16, respectively. Compared with that in sham scald group, the intestinal permeability of mice in pure scald group was significantly elevated (P<0.01), while the intestinal permeability of mice in scald+ sodium butyrate group showed no obvious change (P>0.05). Compared with that in pure scald group, the intestinal permeability of mice in scald+ sodium butyrate group was significantly decreased (P<0.01). (2) At PIH 24, compared with those in sham scald group, the protein expressions of ZO-1, occludin, and claudin-1 of mice in pure scald group and scald+ sodium butyrate group were significantly decreased (P<0.05), while the protein expression of claudin-2 was significantly increased (P<0.05). At PIH 24, compared with those of pure scald group, the protein expressions of ZO-1 and occludin of mice in scald+ sodium butyrate group were significantly elevated (P<0.05), while the protein expression of claudin-2 was significantly decreased (P<0.05), the protein expression of claudin-1 showed no significant difference (P>0.05). (3) At PIH 24, compared with those in sham scald group, the protein expressions of NLRP3, IL-1β, and IL-18 of mice in pure scald group and scald+ sodium butyrate group were significantly increased (P<0.05). Compared with those of pure scald group, the protein expressions of NLRP3, IL-1β, and IL-18 of mice in scald+ sodium butyrate group were significantly decreased (P<0.05). (4) At PIH 24, ZO-1 in intestinal mucosa of mice in sham scald group was distributed smoothly, continuously and homogeneously along the membrane. ZO-1 in intestinal mucosa of mice in pure scald group was distributed unsmoothly with breaks. The distribution of ZO-1 in intestinal mucosa of mice in scald+ sodium butyrate group was ameliorated compared with that in pure scald group. Conclusions Sodium butyrate can inhibit the activation of NLRP3 inflammasome and decrease the production of IL-1β and IL-18 in intestinal mucosa of severe scald mice, which protects the intestinal barrier function by alleviating the alteration of tight junction protein expression and localization.