[A prospective cohort study on the effect of implant restoration following micro crestal flap-alveolar ridge preservation at molar extraction sockets with severe periodontitis]

Objective: To evaluate the survival rate, success rate, soft tissue conditions and marginal bone level changes of implants following micro crestal flap-alveolar ridge preservation at molar extraction sockets with severe periodontitis, compared to natural healing. Methods: From March 2015 to January 2017, patients scheduled for molar extraction as a consequence of severe periodontitis and planned implant-retained prostheses from Department of Periodontology Peking University School and Hospital of Stomatology were selected. A total of 40 molar extraction sockets from 40 patients received implant placement following micro crestal flap-alveolar ridge preservation or natural healing. The front consecutive 20 teeth were assigned to the natural healing group, and the back ones were assigned to the micro crestal flap-alveolar ridge preservation (MCF-ARP) group. The superstructures were placed 6 months later. Within 2 weeks (baseline) and 1, 2 and 3 years after implant crown restoration, modified plaque index, probing depth, modified bleeding index and keratinized tissue width were recorded every six months. Parallel periapical radiographs were taken to evaluate the peri-implant marginal bone level and to calculate marginal bone loss. Independent sample t test or Mann-Whitney U test were used to compare the differences in the above clinical and imaging indicators between the two groups. Results: The implant survival rate and success rate of the two groups were both 100% (20/20). There were no significant differences in the modified plaque index, probing depth, modified bleeding index, buccal keratinized tissue width and marginal bone loss between two groups at 1, 2 and 3 years after implant crown restoration (all P>0.05). Marginal bone loss was 0.22 (0.14, 0.34) mm in the natural healing group and 0.21 (0.12, 0.30) mm in the MCF-ARP group at a 3-year post-loading evaluation. Conclusions: Within the limitations of the present study, implants placed at ridge preserved and naturally healed molar extraction sockets with severe periodontitis demonstrate comparable clinical outcomes at a 3-year post-loading evaluation.

[Effects of cognition-related lifestyles on early cognitive decline in community older adults in China]

Objective: To investigate the distribution characteristics of cognition-related lifestyles of elderly in communities and explore the integrated effects on early cognitive decline. Methods: The participants were from the Project of Prevention and Intervention of Neurodegenerative Disease for Elderly in China. A total of 2 537 older adults aged ≥60 years without dementia in the 2015 baseline survey and the 2017 follow-up survey were included. The information about their cognition-related lifestyles, including physical exercise, social interaction, leisure activity, sleep quality, smoking status, and alcohol consumption, were collected through questionnaire survey and the integrated scores were calculated. Multivariate logistic regression analysis was used to assess the association between integrated cognition-related lifestyle score and early cognitive decline. Results: In the 2 537 older adults surveyed, 28.7% had score of 5-6, while only 4.8% had high scores for all 6 healthy lifestyles. Significant differences in healthy lifestyle factor distributions were observed between men and women. Multivariate logistic regression model showed that the risks for early cognitive decline in the older adults who had lifestyle score of 4 and 5-6 were lower than that in those with lifestyle score of 0-3 (OR=0.683, 95%CI: 0.457-1.019; OR=0.623, 95%CI: 0.398-0.976; trend P=0.030). In the women, the risks for early cognitive decline was lower in groups with score of 4 and 5-6 than in group with score of 0-3 (OR=0.491, 95%CI: 0.297-0.812; OR=0.556, 95%CI: 0.332-0.929; trend P=0.024). Conclusion: Cognition-related healthy lifestyles are associated with significantly lower risk for early cognitive decline in the elderly, especially in women.

Ligature-Induced Periodontitis Drives Colorectal Cancer: An Experimental Model in Mice

Periodontitis is a prevalent inflammatory oral disease associated with an increased risk of colorectal cancer. Experimental animal models are critical tools to investigate the effects and mechanisms of periodontitis on colorectal cancer. Several murine periodontitis models have been used in research, including oral gavage, periodontal pathogen injection, and ligature models. The role of experimental periodontitis caused by silk ligation in colorectal cancer remains unclear. In this study, we used an experimental periodontitis model on a colitis-associated colorectal cancer model and a spontaneous model, respectively. We observed the promotion of colorectal cancer in ligature-induced periodontitis mice compared to those control mice in 2 different models, as assessed by tumor number, tumor size, and tumor load. Since bacterial dysbiosis is an important feature of periodontitis, we next analyzed the oral and gut microbiomes using 16S ribosomal RNA gene sequencing. We found that the experimental periodontitis model reshaped the microbial community in the oral cavity and gut. In addition, we found a higher extent of programmed death 1 (PD-1)-positive CD8⁺ T-cell infiltration in tumor samples of the periodontitis group than in controls by immunofluorescence staining. Regarding the potential molecular mechanism, we transplanted the fecal microbiota of the periodontitis patient into mice and observed a tumor-promoting effect in the periodontitis group, assessed by tumor volume and tumor weight, together with a low level of INF-γ⁺ CD8⁺ T-cell infiltration in subcutaneous tumor mice. Taken together, we show that ligature-induced periodontitis model promotes colorectal cancer by microbiota remodeling and suppression of the immune response.

[Research progress in non-coding RNAs in mediating immune responses of macrophages to Mycobacterium tuberculosis infection]

Tuberculosis (TB) is a chronic infectious disease caused by mycobacterium tuberculosis (MTB) infection. Macrophages are the first line in defensing MTB infection and the main host cells for the growth and persistence of MTB. Changes in macrophage function are critical for the host response to tuberculosis. Non-coding RNAs are involved in the pathophysiological process of many diseases, including TB, and play a very important regulatory role in the macrophage mediated immune response process. Therefore, we reviewed the mechanisms of the non-coding RNAs mediated function alteration of macrophages, in order to facilitate identification of potential therapeutic targets for host-directed anti-TB treatment.

[Efficacy of recombinant human growth hormone treatment in children born small for gestational age with syndromic and non-syndromic short stature]

Objective: To analyse the efficacy of recombinant human growth hormone (rhGH) treatment in children born small for gestational age (SGA) with syndormic and non-syndormic short stature. Methods: The clinical data of 59 children born SGA who were diagnosed as short stature and admitted to the Center of Endocrinology, Genetics and Metabolism, Beijing Children's Hospital from July 2012 to June 2021 were collected and analyzed. According to the 2019 consensus on short stature, they were divided into syndromic group and non-syndromic group. Before treatment and 6, 12, 18 and 24 months after treatment, height standard deviation score (Ht-SDS), difference of height standard deviation (∆Ht-SDS) and homeostasis model assessment-insulin resistance index (HOMA-IR) were compared between groups, while Ht-SDS and HOMA-IR were compared before and after treatment. Independent t test or Kruskal-Wallis test were used for comparison between the 2 groups, and paired t test or Mann-Whitney U test were used for the intra-group comparison. Results: Among the 59 cases, 37 were males and 22 females, aged (5.5±2.3) years. There was no significant difference in Ht-SDS after 12 months of treatment between 2 groups (0.9±0.4 vs. 1.2±0.4, t=1.68, P=0.104) or in height SDS after 24 months of treatment (1.4±0.7 vs. 1.9±0.5, t=1.52, P=0.151). After 12 months of treatment, the insulin resistance index of the non-syndromic group was significantly higher than that of the syndromic group (2.29 (1.43, 2.99) vs. 0.90 (0.55, 1.40), Z=-2.95, P=0.003). There were significant differences in Ht-SDS between 6 months and before treatment, 12 months and 6 months in syndromic type (Z=7.65, 2.83 P<0.001, P=0.020), but all were significant differences in non-syndromic type between 6 months and before treatment, 12 months and 6 months, 18 months and 12 months, 24 months and 18 months (Z=11.95, 7.54, 4.26, 3.83, all P<0.001). Conclusion: The efficacy of rhGH treatment in children born SGA is comparable between syndromic and non-syndromic short stature cases, but non-syndromic children treated with rhGH need more frequent follow-up due to the risk of insulin resistance.

Rapid Determination of 13 Sedative Substances and Their Metabolites in Blood by LC-MS/MS

Objective To establish an analysis method for simultaneous determination of 13 sedative substances and their metabolites in blood by liquid-liquid extraction and liquid chromatography-tandem mass spectrometry （LC-MS/MS） technology and to apply the method to actual cases. Methods The samples were extracted with ethyl acetate after an internal standard was added. The extract was condensed until it was nearly dry and then its residues were dissolved with methanol, filtered through 0.22 μm filter and finally determined. The 13 sedative substances and their metabolites were separated through the C₁₈ chromatographic column, then gradient elution was performed on them with methanol and 20 mmol/L ammonium formate （containing 0.1% formic acid） solution. After that, they were determined in the electrospray positive ion mode and quantified by internal standard method. Results The 13 sedative substances and their metabolites in blood showed good linearity in the range of 5-200 μg/L with correlation coefficients ranging from 0.990 3 to 0.999 8. The detection limits were 0.1-1.0 μg/L. Recovery rates of sedative substances were in the range of 71.2%-93.4% when solutions with concentrations of 10, 50 and 200 μg/L were added. The deviations of intra-day and inter-day relative standard deviations （RSD） were not more than 8.6%. Accuracies （bias） were within ±9.8%. Conclusion This method is rapid, simple, effective and sensitive, and can be applied to analysis of 13 sedative substances and their metabolites in blood in forensic toxicology.

Bax gene silencing: a potential intervention in aluminum-induced neural cell death

There is a vast amount of evidence indicating that Bax plays a major role in the development, maintenance, and survival of neurons and neuron-supporting cells such as glial cells. The high potency of Bax small interfering RNA (siRNA), as shown by many experimental studies, makes it a rational candidate as a co-therapeutic agent in apoptotic cell death. To investigate whether Bax RNA interference (RNAi) may serve as a potential intervention in neural cell death induced by aluminum, we herein established aluminum (Al)-treated gliatoma (C6) cells as a model for evaluating neurotoxic injury on normal glia. Using the cell model, we undertook a different approach by inducing glial cell death with Al and then using Bax gene RNAi to suppress glial cell death. Combining cell viability assays and expression analyses by quantitative real-time PCR (qRT-PCR) and immunocytochemistry, we selected and validated the optimal siRNA from 3 candidate siRNAs for the Bax gene. Sequenced reduction of neural cell death was determined with flow cytometry. Our data identified siRNA1 as the most effective siRNA. The optimal concentration of the transfection agent was 20 nM and the optimal incubation period was 72 h. The transfection and knockdown efficiencies were 95 percent and 62 percent, respectively, which closely correlated with Bax protein expression and also the cell apoptosis intervention. Taken together, Bax is essential for apoptosis induced by aluminum. Inactivation of the Bax gene could be an effective strategy for delaying the onset of apoptosis induced by Al. Our results reveal promising therapeutic potential for Bax gene silencing in Al-induced neurodegeneration.

Therapeutic potential of BAK gene silencing in aluminum induced neural cell degeneration

Previous studies have demonstrated robust BAK gene silencing via RNA interference (RNAi). To investigate whether BAK RNAi may serve as a co-therapeutic agent in neural cell death, we herein established a cell degeneration model using a human neuroblastoma cell line (SH-SY5Y) treated by aluminum (Al). Combining cell viability assays and expression analyses by QRT (quantitative real-time)-PCR and immunocytochemistry, we selected and validated the optimal small interfering RNA (siRNA) from three candidate siRNAs for the BAK gene. Our data identified siRNA1 as the most effective siRNA; the optimal concentration of the transfection agent was 10nM and the optimal incubation period was 24h. The transfection and knockdown efficiency was 93% and 58%, respectively, which closely correlated with the BAK protein expression. SH-SY5Y cells with BAK knockdown showed a clear resistance against cell death and Al-induced apoptosis. These results indicate that genetic inactivation of BAK could be an effective strategy in delaying the onset of apoptosis in Al-treated cells, and exemplify the therapeutic potential of RNAi-based methods for the treatment of neural cell degeneration.

[Effect of alpha-lipoic acid on the apoptosis of PC12 cells induced by 6-hydroxydopamine]

PC12 cell line, a clonal cell line derived from a pheochromocytoma of rat adrenal medulla, was used as a model of dopaminergic neuron in vitro to study the effect of alpha-lipoic acid on the 6-OHDA induced apoptosis. The results from MTT method show that 6-OHDA decreased the cell survival rate obviously. Through TUNEL (TdT-mediated dUTP-biotion nick end labeling) and Flow cytometer (FCM) detection, we found that 6-OHDA triggered cell apoptosis and induced necrosis. It was confirmed by the different percentage of cell survival rate and apoptosis concluded from FCM and MTT. alpha-lipoic acid was used as antioxidant to protect the cell from 6-OHDA's injury. The result indicateed that alpha-lipoic acid can partly prevent apoptosis induced by 6-OHDA but fail to prevent necrosis since it can decrease the apoptotic cell from 20.09% to 3.09%, just as increased cell survival rate from 56.8% to 72.6% but can not reach the normal level showed by MTT assay. Biochemical approach showed the cell's antioxidant ability especial for SOD activity and GSH content increased after the treatment of alpha-lipoic acid. The data suggest that alpha-lipoic acid may protect PC12 cells from apoptosis induced by 6-OHDA through the antioxidant path.

[Clinical study of naoxin sutong in the treatment of acute cerebral infarction]

It was shown that the cerebral ischemia-reperfusion produced free radicals are the main factor that causes irreversible cerebral injury. The mechanism of Naoxin Sutong (NXST) treated acute cerebral infarction was elucidated. It is compared with Ligustrazine (LT), which has been proved to be an effective drug for cerebral infarction. The curative effect and the changes of serum malondialdehyde (MDA) levels, blood rheology, blood lipid, etc. of 41 patients with acute cerebral infarction within 3 days, who were confirmed by CT. The therapeutic result showed that after 4 weeks of treatment the points of progress for central nervous system deficit scoring of NXST and LT group were 10.67 +/- 5.02 and 6.85 +/- 4.49 respectively. The difference between these two groups was significant. MDA levels of the patients and the healthy subjects were 6.46 +/- 1.70 and 3.87 +/- 0.67 nmol/ml respectively, the difference was also significant (P < 0.01). After 2 weeks of treatment, MDA content of NXST was less than before (P < 0.05). However the level of LT group did not reduce, while after 3 weeks of treatment, MDA content of NXST group was 4.34 nmol/ml. It was much less than that of LT group and approached that of healthy subjects. Results also showed that blood rheology improved, blood lipid reduced after NXST treatment. All these indicated that the effect of NXST in treating acute cerebral infarction was good, and the mechanism as that NXST could scavenge free radicals, ameliorate cerebral ischemia-reperfusion injury, improve blood rheology and reduce blood lipid.