Omics for deciphering oral microecology / 国际口腔科学杂志·英文版

The human oral microbiome harbors one of the most diverse microbial communities in the human body, playing critical roles in oral and systemic health. Recent technological innovations are propelling the characterization and manipulation of oral microbiota. High-throughput sequencing enables comprehensive taxonomic and functional profiling of oral microbiomes. New long-read platforms improve genome assembly from complex samples. Single-cell genomics provides insights into uncultured taxa. Advanced imaging modalities including fluorescence, mass spectrometry, and Raman spectroscopy have enabled the visualization of the spatial organization and interactions of oral microbes with increasing resolution. Fluorescence techniques link phylogenetic identity with localization. Mass spectrometry imaging reveals metabolic niches and activities while Raman spectroscopy generates rapid biomolecular fingerprints for classification. Culturomics facilitates the isolation and cultivation of novel fastidious oral taxa using high-throughput approaches. Ongoing integration of these technologies holds the promise of transforming our understanding of oral microbiome assembly, gene expression, metabolites, microenvironments, virulence mechanisms, and microbe-host interfaces in the context of health and disease. However, significant knowledge gaps persist regarding community origins, developmental trajectories, homeostasis versus dysbiosis triggers, functional biomarkers, and strategies to deliberately reshape the oral microbiome for therapeutic benefit. The convergence of sequencing, imaging, cultureomics, synthetic systems, and biomimetic models will provide unprecedented insights into the oral microbiome and offer opportunities to predict, prevent, diagnose, and treat associated oral diseases.

Expert consensus on early childhood caries management / 国际口腔科学杂志·英文版

Early childhood caries (ECC) is a significant chronic disease of childhood and a rising public health burden worldwide. ECC may cause a higher risk of new caries lesions in both primary and permanent dentition, affecting lifelong oral health. The occurrence of ECC has been closely related to the core microbiome change in the oral cavity, which may be influenced by diet habits, oral health management, fluoride use, and dental manipulations. So, it is essential to improve parental oral health and awareness of health care, to establish a dental home at the early stage of childhood, and make an individualized caries management plan. Dental interventions according to the minimally invasive concept should be carried out to treat dental caries. This expert consensus mainly discusses the etiology of ECC, caries-risk assessment of children, prevention and treatment plan of ECC, aiming to achieve lifelong oral health.

Oral microbiota in human systematic diseases / 国际口腔科学杂志·英文版

Oral bacteria directly affect the disease status of dental caries and periodontal diseases. The dynamic oral microbiota cooperates with the host to reflect the information and status of immunity and metabolism through two-way communication along the oral cavity and the systemic organs. The oral cavity is one of the most important interaction windows between the human body and the environment. The microenvironment at different sites in the oral cavity has different microbial compositions and is regulated by complex signaling, hosts, and external environmental factors. These processes may affect or reflect human health because certain health states seem to be related to the composition of oral bacteria, and the destruction of the microbial community is related to systemic diseases. In this review, we discussed emerging and exciting evidence of complex and important connections between the oral microbes and multiple human systemic diseases, and the possible contribution of the oral microorganisms to systemic diseases. This review aims to enhance the interest to oral microbes on the whole human body, and also improve clinician's understanding of the role of oral microbes in systemic diseases. Microbial research in dentistry potentially enhances our knowledge of the pathogenic mechanisms of oral diseases, and at the same time, continuous advances in this frontier field may lead to a tangible impact on human health.

Comparison of the effects of different digestive tract reconstruction methods in laparoscopic assisted radical gastrectomy for distal gastric cancer / 中国综合临床

Objective:To evaluate the feasibility, safety and efficacy of uncut Roux-en-Y anastomosis, Roux-en-Y anastomosis and Billroth Ⅱ plus Braun anastomosis in laparoscopic-assisted distal gastrectomy for distal gastric cancer.Methods:In the retrospective cohort study, 71 cases of laparoscopic-assisted distal gastrectomy for distal gastric cancer from May 2016 to October 2019 in Tangshan Union Medical College Hospital were selected as the study subject. According to the different reconstruction methods of digestive tract, they were divided into: non disconnected Roux-en-Y anastomosis group (Uncut RY group, 29 cases); Roux-en-Y anastomosis group (RY group, 24 cases); Billroth Ⅱ-braun anastomosis group (B Ⅱ-Braun group, 18 cases). The operation time, digestive tract reconstruction time, intraoperative blood loss, the time to flatus, length of hospital stay, incidence of complication and the changes of nutritional index 1 year after surgery were observed. SPSS 18.0 software was used process the data, the measurement data conforming to normal distribution by Kolmogorov-Smirnov test was expressed by xˉ± s deviation, the measurement data dose not meet the normal distribution was expressed by the median (interquartile range) ( M( Q1, Q3)).Analysis of variance was used to compare the measurement data of normal distribution; Nonparametric rank sum test was used for the comparison between measurement data groups with non normal distribution; Count data were expressed in cases (%), and χ 2 test or Fisher exact probability method was used for composition comparison between groups. Results:In Uncut group, RY group and B Ⅱ-Braun group, the operation time were (196.0±28.8) min, (201.0±28.5) min and (186.4±26.1) min, respectively, the digestive tract reconstruction time were (56.2±13.9) min, (57.8±12.9) min and (51.5±10.0) min, respectively,the intraoperative blood loss were (285.2±85.4) mL, (280.1±78.4) mL and (273.3±79.6) mL, respectively, the time to flatus were (52.5±14.4) h,(53.9±14.6) h and (46.2±9.4) h, respectively, the length of hospital stay were (12.6±2.8) d, (12.1±3.0) d and (12.8±2.6) d, respectively, there were no significant differences among the three groups ( F values were 1.41, 1.33, 0.12, 1.89 and 0.35, respectively; P values were 0.251, 0.271, 0.890, 0.158 and 0.709, respectively). Postoperative complications in Uncut group, RY group and BⅡ-Braun group: The number of cases of anastomotic leakage was 0, 1 and 1, respectively. The number of cases of abdominal bleeding was 1, 1 and 0, respectively. The number of cases of bile reflux gastritis was 2, 1 and 5, respectively, and the number of cases of anastomotic ulcer was 0, 0 and 1, respectively. There were no significant differences among the three groups (Fisher's exact test, P values were 0.510,1.000, 0.063 and 0.254, respectively). The number of cases of Roux-en-Y retention syndrome was 0, 6 and 0, respectively. There were significant differences among the three groups (Fisher's exact test, P=0.001). Nutritional index: the weight loss were 4.00 (2.00, 5.50) kg, 3.00 (1.25,4.75) kg and 3.00 (1.75,4.25) kg respectively, decreases of hemoglobin level were (5.62±8.20) g/L, (6.63±6.84) g/L and(5.33±7.79) g/L, respectively, decreases of albumin level were 1.00 (-2.50, 7.00) g/L, 3.00 (-1.25, 6.75) g/L and 6.00 (-3.25,7.50) g/L, respectively. There were no significant differences among the three groups (Statistic value were χ 2=1.42, F=0.18 and χ 2=2.43, respectively, P values were 0.492,0.839 and 0.297, respectively). Conclusion:As a digestive tract reconstruction method for radical resection of distal gastric cancer, uncut Roux-en-Y anastomosis can reduce the incidence of Roux-en-Y retention syndrome without increasing the operation risk and affecting the postoperative nutritional status. It is a safe and feasible gastrointestinal tract reconstruction method.

Effect observation of uncut Roux-en-Y anastomosis in laparoscopic assisted radical gastrectomy for distal gastric cancer / 中国综合临床

Objective:To investigate the effect of uncut Roux-en-Y anastomosis in laparoscopic assisted radical gastrectomy for distal gastric cancer.Methods:The clinical data of 53 patients with distal gastric cancer treated by surgery in Tangshan Union Medical College Hospital from May 2016 to October 2019 were analyzed retrospectively.The operation method was laparoscopic assisted radical gastrectomy for distal gastric cancer.The anastomosis methods were uncut Roux-en-Y anastomosis in 29 cases (uncut group) and Roux-en-Y anastomosis in 24 cases (traditional group). The operation time, digestive tract reconstruction time, the time to flatus, length of hospital stay, incidence of complication and one year followed up results were compared between the two groups.Results:The operation time was (196.0±28.8) min, anastomotic time was (56.1±13.8) min, postoperative exhaust time was (52.5±14.4) h, postoperative hospital stay was (12.5±2.8) d in the uncut group, and (201.0±28.5) min, (57.8±12.9) min, (53.9±14.6) h, (12.0±3.0) d in the traditional group.There was no significant difference between the two groups ( P values were 0.534, 0.664, 0.717 and 0.557, respectively). Postoperative complications: anastomotic leakage was 0(0/29), abdominal bleeding was 3.4% (1/29), alkaline reflux gastritis was 6.9% (2/29) in the uncut group and 4.2% (1/24), 4.2% (1/24) and 4.2% (1/24) in the traditional group respectively.There was no significant difference between the two groups ( P values were 0.453, 1.000 and 1.000, respectively). The incidence of Roux-en-Y stasis syndrome was 0 (0/29) in the uncut group and 25.0% (6/24) in the traditional group.There was significant difference between the two groups ( P=0.006). One case in the uncut group was found recanalization 8 months after operation, the patient underwent reoperation, the method of anastomosis was changed to traditional Roux-en-Y anastomosis.The patient′s symptoms of reflux and hearburn improved significantly after operation. Conclusion:As a digestive tract reconstruction method for radical gastrectomy of distal gastric cancer, uncut Roux-en-Y anastomosis is safe and feasible, and can avoid Roux-en-Y stasis syndrome.

Association between sleep with C reactive protein and insulin metabolism in adolescents / 中国学校卫生

Objective@#To explore the relationship of sleep with C reactive protein (CRP) abnormality and hyperinsulinemia in adolescents, and to provide reference for early prevention of metabolic disorders.@*Methods@#Based on the Chinese Metabolic Syndrome Cohort Study in Anhui Province, a total of 653 adolescents aged 12 to 19 were selected to examine the relationship between wakeup time, bedtime, sleep disordered breathing (SDB) and CRP abnormality as well as hyperinsulinemia.@*Results@#Later wakeup time (OR=1.68, 95%CI=1.03-2.75) was positively correlated with a higher risk of fasting hyperinsulinemia. Late bedtime (OR=1.96, 95%CI=1.29-2.99) was associated with 2 h postprandial hyperinsulinemia. Among those with high CRP concentration, late wakeup time and late bedtime were positely associated with hyperinsulinemia than those with normal CRP concentration; and the correlation between SDB and hyperinsulinemia was observed.@*Conclusion@#Later wakeup and late bedtime may be risk factors for hyperinsulinemia in adolescents. High concentrations of CRP may further increase the risk of hyperinsulinemia, a condition associated with sleep problems.Teenagers should get up and go to bed as early as possible.

Practice and thoughts of integrating curriculum ideological and political education into oral microbiology course / 中华医学教育探索杂志

This study explores the process of introducing ideological and political education elements into oral microbiology teaching, and helps students to establish Marxist practical, epistemological and scientific and technological views, understand the strategic connotation of healthy China in the new era, and establish a sense of responsibility to serve the needs of the country and promote social development. Finally, through the collection of students' feedback, the implementation effect is summarized and the existing problems have been improved in a targeted way.

Characteristics of oral methicillin-resistant Staphylococcus epidermidis isolated from dental plaque / 国际口腔科学杂志·英文版

The oral microbial community is widely regarded as a latent reservoir of antibiotic resistance genes. This study assessed the molecular epidemiology, susceptibility profile, and resistance mechanisms of 35 methicillin-resistant Staphylococcus epidermidis (MRSE) strains isolated from the dental plaque of a healthy human population. Broth microdilution minimum inhibitory concentrations (MICs) revealed that all the isolates were nonsusceptible to oxacillin and penicillin G. Most of them were also resistant to trimethoprim (65.7%) and erythromycin (54.3%). The resistance to multiple antibiotics was found to be largely due to the acquisition of plasmid-borne genes. The mecA and dfrA genes were found in all the isolates, mostly dfrG (80%), aacA-aphD (20%), aadD (28.6%), aphA3 (22.9%), msrA (5.7%), and the ermC gene (14.3%). Classical mutational mechanisms found in these isolates were mainly efflux pumps such as qacA (31.4%), qacC (25.7%), tetK (17.1%), and norA (8.6%). Multilocus sequence type analysis revealed that sequence type 59 (ST59) strains comprised 71.43% of the typed isolates, and the eBURST algorithm clustered STs into the clonal complex 2-II(CC2-II). The staphyloccoccal cassette chromosome mec (SCCmec) type results showed that 25 (71.43%) were assigned to type IV. Moreover, 88.66% of the isolates were found to harbor six or more biofilm-associated genes. The aap, atlE, embp, sdrF, and IS256 genes were detected in all 35 isolates. This research demonstrates that biofilm-positive multiple-antibiotic-resistant ST59-SCCmec IV S. epidermidis strains exist in the dental plaque of healthy people and may be a potential risk for the transmission of antibiotic resistance.

Transmission routes of 2019-nCoV and controls in dental practice / 国际口腔科学杂志·英文版

A novel β-coronavirus (2019-nCoV) caused severe and even fetal pneumonia explored in a seafood market of Wuhan city, Hubei province, China, and rapidly spread to other provinces of China and other countries. The 2019-nCoV was different from SARS-CoV, but shared the same host receptor the human angiotensin-converting enzyme 2 (ACE2). The natural host of 2019-nCoV may be the bat Rhinolophus affinis as 2019-nCoV showed 96.2% of whole-genome identity to BatCoV RaTG13. The person-to-person transmission routes of 2019-nCoV included direct transmission, such as cough, sneeze, droplet inhalation transmission, and contact transmission, such as the contact with oral, nasal, and eye mucous membranes. 2019-nCoV can also be transmitted through the saliva, and the fetal-oral routes may also be a potential person-to-person transmission route. The participants in dental practice expose to tremendous risk of 2019-nCoV infection due to the face-to-face communication and the exposure to saliva, blood, and other body fluids, and the handling of sharp instruments. Dental professionals play great roles in preventing the transmission of 2019-nCoV. Here we recommend the infection control measures during dental practice to block the person-to-person transmission routes in dental clinics and hospitals.

Survey of exposure to second-hand smoke in residents aged 15 years and over one year after implementation of tobacco control regulation in public places in Beijing / 中华流行病学杂志

Objective@#To monitor the second-hand smoke (SHS) exposure in residents aged 15 years and over in public venues, indoor workplaces, on public transportation vehicles and at home in Beijing and evaluate the effect of Beijing Tobacco Control Regulation.@*Methods@#Data from 2014 and 2016 Beijing Adult Tobacco Survey were used. The surveys covered 16 districts in Beijing. The study subjects were selected through multi-stage cluster sampling with probability proportional to population size, and data were collected by using electronic questionnaire in face-to-face household interviews. A total of 8 484 and 9 372 valid questionnaires were collected for the surveys in 2014 and 2016, respectively. Statistical packages SPSS 20.0 and R 3.4.4 were used for data analyses. After weighting the samples using complex survey designs, the SHS exposure rates in different places in adults of Beijing were estimated. χ2 tests were performed for the comparison.@*Results@#The SHS exposure rates of residents aged 15 years and over in Beijing who visited health care facilities, government buildings, universities, primary and secondary schools and restaurants declined from 12.8%, 19.7%, 24.3%, 32.8% and 65.7% in 2014 to 6.2%, 10.8%, 12.5%, 19.1% and 32.5% in 2016, respectively. The SHS exposure rates in bars/nightclubs were 89.5% in 2014 and 80.3% in 2016. From 2014 to 2016, the SHS exposure rates declined from 35.7% to 20.0% in indoor workplaces and declined from 3.9% to 2.5% on public transportation vehicles. The SHS exposure rates at home were 39.8% in 2014 and 37.6% in 2016, respectively.@*Conclusions@#The SHS exposure rates in public places declined obviously in Beijing after the one year implementation of Beijing Tobacco Control Regulation, indicating the effect of the regulation implementation.

One year after the implementation of 2015 Tobacco Control Regulation on persons aged 15 years and over tobacco use in Beijing / 中华流行病学杂志

Objective To understand the current status of smoking and smoking cessation in persons aged 15 years and over in Beijing and evaluate the effect of 2015 Beijing Tobacco Control Regulation.Methods In 2014 and 2016,based on the principles and methodology of the Global Adult Tobacco Survey.A total of 50 communities or townships were selected from 324 communities or townships in Beijing through multistage cluster sampling,and 2 community (village) committees from each community or township were selected with the method of probability proportional to size (PPS).A total of 100 surveillance sites were set,and 100 households were selected from each surveillance site by using simple random sampling.Data were collected through face-to-face interview from the eligible family members aged 15 years and over with the assistance of a tablet computen Statistical analyses were conducted by using complex sampling analyses module of SPSS 20.0,with weights as a combination of sampling weights,non-response weights and post-stratification weights,for the calculation of current smoking prevalence,daily smoking prevalence,smoking cessation rate,etc.Results A total of 8 484 and 9 372 valid questionnaires were obtained,respectively,in 2014 and 2016,with the response rate of 86.5％ and 96.5％.The current smoking prevalence in persons aged 15 years and over was 23.4％ in 2014,and 22.3％ in 2016.According to the 6th national census data,the current smoking population decreased by 199 000 in Beijing.The proportion of daily smokers declined from 20.7％ in 2014 to 19.2％ in 2016.The daily number of cigarettes consumed by current smokers increased from 14.6 in 2014 to 15.4 in 2016.The smoking cessation rate was 14.9％ in 2014 and 16.8％ in 2016.The proportion of current smokers who had at least one smoking cessation attempt in the past 12 months increased from 22.3％ in 2014 to 23.2％ in 2016,and the proportion of current smokers who planned to quit smoking increased from 11.6％ to 15.5％.Among the current smokers who had visited doctors in the past 12 months,the proportion of those having smoking cessation advice was 58.9％ in 2014 and 59.2％ in 2016.In 2016,among the current smokers who had attempted to quit in the past 12 months,36.8％ were aware of the smoking cessation clinics,and 29.5％were aware of the quitline.Among those who were aware,only 7.7％ had actually visited the cessation clinics,and 5.5％ had used the quitline.Conclusions After the implementation of 2015 Beijing Tobacco Control Regulation for 1 year,the current smoking prevalence in persons aged 15 years and over showed decreasing.It is necessary to further prompt the expansion of smoking cessation service to cover more current smokers.

One year after the implementation of 2015 Tobacco Control Regulation on persons aged 15 years and over tobacco use in Beijing / 中华流行病学杂志

Objective To understand the current status of smoking and smoking cessation in persons aged 15 years and over in Beijing and evaluate the effect of 2015 Beijing Tobacco Control Regulation.Methods In 2014 and 2016,based on the principles and methodology of the Global Adult Tobacco Survey.A total of 50 communities or townships were selected from 324 communities or townships in Beijing through multistage cluster sampling,and 2 community (village) committees from each community or township were selected with the method of probability proportional to size (PPS).A total of 100 surveillance sites were set,and 100 households were selected from each surveillance site by using simple random sampling.Data were collected through face-to-face interview from the eligible family members aged 15 years and over with the assistance of a tablet computen Statistical analyses were conducted by using complex sampling analyses module of SPSS 20.0,with weights as a combination of sampling weights,non-response weights and post-stratification weights,for the calculation of current smoking prevalence,daily smoking prevalence,smoking cessation rate,etc.Results A total of 8 484 and 9 372 valid questionnaires were obtained,respectively,in 2014 and 2016,with the response rate of 86.5％ and 96.5％.The current smoking prevalence in persons aged 15 years and over was 23.4％ in 2014,and 22.3％ in 2016.According to the 6th national census data,the current smoking population decreased by 199 000 in Beijing.The proportion of daily smokers declined from 20.7％ in 2014 to 19.2％ in 2016.The daily number of cigarettes consumed by current smokers increased from 14.6 in 2014 to 15.4 in 2016.The smoking cessation rate was 14.9％ in 2014 and 16.8％ in 2016.The proportion of current smokers who had at least one smoking cessation attempt in the past 12 months increased from 22.3％ in 2014 to 23.2％ in 2016,and the proportion of current smokers who planned to quit smoking increased from 11.6％ to 15.5％.Among the current smokers who had visited doctors in the past 12 months,the proportion of those having smoking cessation advice was 58.9％ in 2014 and 59.2％ in 2016.In 2016,among the current smokers who had attempted to quit in the past 12 months,36.8％ were aware of the smoking cessation clinics,and 29.5％were aware of the quitline.Among those who were aware,only 7.7％ had actually visited the cessation clinics,and 5.5％ had used the quitline.Conclusions After the implementation of 2015 Beijing Tobacco Control Regulation for 1 year,the current smoking prevalence in persons aged 15 years and over showed decreasing.It is necessary to further prompt the expansion of smoking cessation service to cover more current smokers.

Construction of a low-pH-sensing system in Streptococcus mutans / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To construct a low-pH-sensing system in Streptococcus mutans (S. mutans) and to visually detect the pH in situ.</p><p><b>METHODS</b>Promoter of ureaseⅠ(PureⅠ) and green fluorescence protein (gfp) DNA fragments were amplified by polymerase chain reaction (PCR) from the genome of Streptococcus salivarius 57.I and S. mutans containing the gfp fragment. The two amplified DNA fragments were ligated together and further integrated into pDL278 to construct the recombinant plasmid pDL278-pureⅠ-gfp. This recombinant plasmid was then transformed into S. mutans UA159 cells. Subsequently, the intensity of the optical density per unit area of the low-pH-sensing system was measured and compared under different pH conditions and different processing times.</p><p><b>RESULTS</b>PureⅠ and gfp DNA fragments were amplified successfully with the correct molecule sizes (450 and 717 bp, respectively). The recombinant plasmid pDL278-pureⅠ-gfp was constructed and further verified by PCR and sequencing. The intensity of the optical density per unit area of the low-pH-sensing system increased with decreasing pH and increasing processing time.</p><p><b>CONCLUSIONS</b>A low-pH-sensing system was constructed successfully in S. mutans. Our research verified that pureⅠ of Streptococcus salivarius can function well in S. mutans as an acid induced promoter, and provided a new method of detecting the pH of plaque biofilms in situ.</p>

Effects of different pH conditions on ffh gene expression in Streptococcus mutans / 华西口腔医学杂志

<p><b>OBJECTIVE</b>This research aimed to detect the expression levels of ffh gene in Streptococcus mutans (S. mutans) UA159 under different pH conditions, analyze the effect of pH on the expression of ffh gene in S. mutans, and identify the factors regulating the ffh gene expression.</p><p><b>METHODS</b>Samples of S. mutans were collected at different growth stages (4 h, 18 h) and pH values (pH 4.0-7.0). Fluorescence quantitative real-time polymerase chain reaction (qRT-PCR) was used to measure the relative mRNA expression and trend of the target gene ffh in S. mutans at different growth stages and pH values.</p><p><b>RESULTS</b>qRT-PCR results showed that the ffh gene expression decreased along with pH at 4 h, but the expression increased with decreasing pH at 18 h. Under the same pH conditions, the ffh gene expression was significantly different between 4 h and 18 h (P < 0.05).</p><p><b>CONCLUSION</b>Growth stage and pH value influenced the ffh gene expression in S. mutans.</p>

Progress on space oral medicine research under microgravity environment / 华西口腔医学杂志

As an interdisciplinary of stomatology and space medicine, space oral medicine focuses mainly on oral diseases happened under space environment. With the manned space technology stepping into the new era, space oral medicine has been put under the spotlight. This article will review the historical events on this subject, summarize the newly progress especially on craniomaxillofacial bone, tooth-derived stem cell and oral microbiology researches and still put forward future prospect.

Cloning, expression, and purification of c-di-AMP metabolism-related genes from Porphyromonas gingivalis / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To clone, express, and purify cyclic diadenosine monophosphate (c-di-AMP) metabolism-related genes from Porphyromonas gingivalis (P. gingivalis) ATCC33277.</p><p><b>METHODS</b>Polymerase chain reaction (PCR) from the genome of P. gingivalis ATCC33277 amplified, the coding regions of pgn0523, pgn1187, and pgn2003 genes. The amplified DNA fragments were ligated with a prokaryotic expression vector pET28a to construct the recombinant expression plasmids pET-pgn0523, pET-pgn1187, and pET-pgn2003. These recombinant plasmids were transformed into Escherichia coli (E. coli) BL21 (DE3) competent cells. The expression of recombinant proteins was induced by isopropyl-β-D-thiogalactoside and detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Proteins were purified using a Ni²⁺ matrix column, and their concentrations were determined by a BCA Protein Quantitative Kit.</p><p><b>RESULTS</b>The c-di-AMP metabolism-related genes from P. gingivalis ATCC33277 were amplified successfully with the correct molecular size. The recombinant expression vectors were constructed by ligating enzyme-digested PCR products and pET28a vector, and verified by PCR and sequencing. After induction and purification, recombinant proteins were expressed successfully and obtained with the correct molecular size (19.5 x 10³, 39.9 x 10³, 66.0 x 10³). The final protein concentrations were 0.708, 0.523, and 0.861 mg · mL⁻¹ after dialysis.</p><p><b>CONCLUSION</b>The c-di-AMP metabolism-related genes from P. gingivalis ATCC33277 are cloned successfully, and their coding products are expressed correctly in E. coli. High-purity proteins are finally obtained. The cloning and purification of these important proteins will help us to further investigate the physiological function and regulatory mechanism of c-di-AMP signaling system in P. gingivalis.</p>

The effects of exposure to the famine during early life with elevated resting heart rate in the adult / 中华预防医学杂志

<p><b>OBJECTIVE</b>To investigate the association between exposure to the famine during early life and elevated resting heart rate (RHR) in adulthood.</p><p><b>METHOD</b>From June 2006 to October 2007, the employees of kailuan group who took part in the health examination were selected. Of those, 18 619 cases who was born during October 1, 1956 to September 30, 1964 in Hebei province were finally included in the analysis based on the inclusion and exclusion criteria. All the subjects were received questionnaire survey, smoking and drinking, physical examination, Lab examination and the measurement of RHR. The subjects of famine exposure group (3 190 cases) were born from October 1, 1959 to September 30, 1961, semi-exposure group (3 851 cases) were born from October 1, 1958 to September 30, 1959 and from October 1, 1961 to September 30, 1962, control group (11 578 cases) were born from October 1, 1956 to September 30, 1958 and from October 1, 1962 to September 30, 1964. The RHR and the detection rate of elevated RHR were compared among the three groups. The Multivariate logistic regression model was used to analyze the association between of exposure to famine during early life and elevated RHR in adulthood.</p><p><b>RESULTS</b>The RHR level was higher in famine exposure group and semi-exposed group than control group, which were (74.34 ± 9.71), (74.41 ± 9.48) and (73.90 ± 9.45) beat per minute (bpm) (P values were 0.003 and 0.020, respectively). In all of the subjects. The results of multivariate logistic regression showed that exposure of famine during early life increased the risk of elevated RHR in adulthood after adjustment for age, gender and other confounders (OR = 1.10, 95% CI: 1.01-1.21). In men, exposure of famine during early life also increased the risk of elevated RHR in adulthood (OR = 1.15, 95% CI: 1.04-1.28); In women, there was no association between the famine exposure and elevated RHR (OR = 0.92, 95% CI: 0.74-1.14).</p><p><b>CONCLUSION</b>Exposure of famine during early life increases the risk of elevated RHR in adulthood. This negative effect existed mainly in the male.</p>

Clinical and imaging features of Gorham disease:a report of eleven cases and review of literature / 中华放射学杂志

Objective To evaluate the clinical and radiological features of Gorham disease. Methods Clinical and radiological features of Gorham disease were retrospectively analyzed by reviewing the eleven cases from our hospital and the cases reported in the domestic literature in the past fifty years. The diagnoses of all these 11 patients were in accordance with the diagnostic criteria established by Wells and Gray et al. All patients had X?ray plain film, four had CT scan and five had MR examination, with one had additional contrast?enhanced MR examination. Results There were 7 males and 4 females, age ranged from 16 to 66 years with a median age of 32 years. There were six cases involving hand, one involving ulnar and radial bones, one involving acetabulum and three involving jaw bones. The main clinical manifestations were pain, swelling, limited activity, and focal muscular atrophy occurred in 7 cases. On X?ray plain films, the affected bone became thin and the cortexes were not smooth and became coarse in 6 cases. Local lucent area was seen in 5 cases and massive bone absorption was seen in 6 cases. The residual bones showed a tapering appearance in 1 case. Pathological fracture occurred in 1 case. On CT scans, the affected bone became thin and the cortexes became coarse in 4 cases. Local lucent area was seen in 1 case. Massive bone absorption was seen in 3 cases. The adjacent muscular atrophy and widened intermuscular fat space occurred in 2 cases (atrophic bone absorption). On MRI, normal signal intensity of bone marrow disappeared and demonstrated low signal on T1WI and high signal on T2WI. The signal could be homogeneous or heterogeneous. There were widespread strip and patchy high signal areas in the soft tissue around the absorption areas in 4 cases, which resembled the edema?like signal. In 1 case, there was irregular widespread soft tissue mass around the absorption areas with heterogeneous high signal on T2WI. The adjacent muscle showed atrophy, and the intermuscular fat space became wide. There were a total of 92 cases reported cases in the literature including our 11 cases. There were 63 males and 29 females. The onset age ranged from 10 to 40 years in 66/92(72%)cases. The lesion affected one bone in 24 cases, affected two or more bones in 68 cases, out of which 9 cases had single center distribution, 59 cases had multiple centers distribution. Pectoral girdle, pelvis, maxillofacial bones, and hand were the most common sites of involvement in decreasing order. Forty three cases had muscle atrophy and 8 cases had soft tissue mass. Conclusion Gorham disease should be considered when atrophic bone absorption in one bone or continuous bones occurs that does not match clinical symptoms, with soft tissue atrophy but no bone sclerosis or periosteal reaction in the osteolytic areas.

Overview of researches for Helicobacter pylori in oral cavity and stomach / 华西口腔医学杂志

Helicobacter pylori (H. pylori) is one of the most common pathogens in human and it is closely related to gastrointestinal diseases. It is essential for us to understand the transmission process of H. pylori to prevent its spreading. The oral cavity has been proposed as a reservoir for gastric H. pylori, which has been detected by culture and polymerase chain reaction (PCR) in both dental plaque and saliva. Some researchers have proposed H. pylori in oral cavity may play an important role in its transmission and reinfection. Oral-oral or fecal-oral transmission are thought to be the most possible transmit way. This review will discuss the evidence for the role of the oral cavity in the transmission of H. pylori, the difficulties encountered in addressing this topic and possible directions for future research. Oral H. pylori may also play a role in the diagnosis and prevention of deceases related to H. pylori such as gastritis, gastric ulcer and gastric carcinoma. The recent progresses in this area are also reviewed. Moreover, we also discussed the relationship between oral H. pylori and oral deceases like periodontal disease and oral ulcer.

Analysis of the oral microbiota in twin children / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To analyze the differences between the oral microbiota of monozygotic and dizygotic twins by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE).</p><p><b>METHODS</b>A total of 20 pairs of twin children were included in this study, in which 10 pairs were monozygotic (MZ) twins, and 10 pairs were dizygotic (DZ) twins. Of the 20 pairs, 10 pairs of twins had primary dentition, and 10 pairs had mixed dentition; 17 children had caries, and 23 children had no caries. Genomic DNA was extracted from saliva samples. The 16s rRNA was amplified and analyzed by PCR-DGGE. The PCR-DGGE band number and Shannon index were calculated.</p><p><b>RESULTS</b>Cluster analysis showed high similarity in the oral bacterial community seen in co-twins. However, no significant difference was seen between MZ and DZ twins. In the primary dentition, the PCR-DGGE band number and Shannon index of children with caries (11.00 +/- 1.56, 1.05 +/- 0.36) were lower than those of children without caries (14.00 +/- 2.74, 1.44 +/- 0.37) (P < 0.05). In mixed dentition, the PCR-DGGE band number and Shannon index of children with caries (11.88 +/- 4.05, 1.18 +/- 0.36) were lower than those of children without caries (14.31 +/- 5.71, 1.28 +/- 0.47), but the differences were not statistically significant (P > 0.05).</p><p><b>CONCLUSION</b>Environmental factors may have a stronger effect on the constitution of oral microbiota in children compared with genetic factors. Children without caries may have a richer microbial diversity compared with children with caries.</p>