Long-Term Prognosis of Different Reperfusion Strategies for ST-Segment Elevation Myocardial Infarction in Chinese County-Level Hospitals: Insight from China Acute Myocardial Infarction Registry / 生物医学与环境科学（英文）

OBJECTIVE@#To evaluate the long-term prognosis of patients with ST-segment elevation myocardial infarction (STEMI) treated with different reperfusion strategies in Chinese county-level hospitals.@*METHODS@#A total of 2,514 patients with STEMI from 32 hospitals participated in the China Acute Myocardial Infarction registry between January 2013 and September 2014. The success of fibrinolysis was assessed according to indirect measures of vascular recanalization. The primary outcome was 2-year mortality.@*RESULTS@#Reperfusion therapy was used in 1,080 patients (42.9%): fibrinolysis ( n= 664, 61.5%) and primary percutaneous coronary intervention (PCI) ( n= 416, 38.5%). The most common reason for missing reperfusion therapy was a prehospital delay > 12 h (43%). Fibrinolysis [14.5%, hazard ratio ( HR): 0.59, 95% confidence interval ( CI) 0.44-0.80] and primary PCI (6.8%, HR= 0.32, 95% CI: 0.22-0.48) were associated with lower 2-year mortality than those with no reperfusion (28.5%). Among fibrinolysis-treated patients, 510 (76.8%) achieved successful clinical reperfusion; only 17.0% of those with failed fibrinolysis underwent rescue PCI. There was no difference in 2-year mortality between successful fibrinolysis and primary PCI (8.8% vs. 6.8%, HR = 1.53, 95% CI: 0.85-2.73). Failed fibrinolysis predicted a similar mortality (33.1%) to no reperfusion (33.1% vs. 28.5%, HR= 1.30, 95% CI: 0.93-1.81).@*CONCLUSION@#In Chinese county-level hospitals, only approximately 2/5 of patients with STEMI underwent reperfusion therapy, largely due to prehospital delay. Approximately 30% of patients with failed fibrinolysis and no reperfusion therapy did not survive at 2 years. Quality improvement initiativesare warranted, especially in public health education and fast referral for mechanical revascularization in cases of failed fibrinolysis.

Considerations of the classification and treatment for fused teeth / 中华口腔医学杂志

Fused teeth were a phenomena of teeth anomalies in shape, which can affect the dental teeth both in primary and permanent dentition. Fused teeth do not only cause problems on crowding of dentition, abnormal occlusion and aesthetic, but also increase risks of dental caries, endodontics diseases, periapical diseases and periodontal diseases. Fusion of deciduous teeth may lead to abnormality of subsequent permanent teeth. Treatment of fused teeth may require multidisciplinary approach in endodontics, periodontics, oral and maxillofacial surgery, prosthodontics and orthodontics. The aim of the present article is to review the etiology, classification, clinical manifestations and treatment of fused teeth in order to provide dental clinicians with a reference of clinical management for fused teeth.

Intestinal Cckbr-specific knockout mouse as a novel model of salt-sensitive hypertension via sodium over-absorption / 老年心脏病学杂志（英文版）

OBJECTIVES@#To investigate the value of CCKBRfl/fl villin-Cre mice as a mouse model of salt-sensitive hypertension (SSH).@*METHODS@#In the first part, 2-month-old CCKBRfl/fl villin-Cre mice (CKO) and control CCKBRfl/fl mice (WT) were fed with normal diet (0.4% NaCl) or high salt diet (4% NaCl), separately for 6 weeks. In the rescue study, one week of hydrochlorothiazide or saline injection were treated with the CKO mice fed high salt diet. The blood pressure, biochemical indexes, and the expression of small intestinal sodium transporters (NHE3, NKCC1, eNaC) was detected. The organ injury markers (MMP2/MMP9) and the histopathological changes of kidneys were observed, whereas the changes of duodenal sodium absorption were detected by small intestinal perfusion in vivo.@*RESULTS@#The CCKBRfl/fl villin-Cre mice with high salt intake exhibited high blood pressure, increased duodenal sodium absorption and urinary sodium excretion, and with renal injury. The protein expression of NHE3, NKCC1 and eNaC were also significant increase in the intestine of CKO-HS mice. Treatment with hydrochlorothiazide remarkably attenuated the elevated blood pressure by high salt absorption in the CCKBRfl/fl villin-Cre mice, but no significant histopathological changes were observed.@*CONCLUSIONS@#These results support a crucial role of intestinal Cckbr deficiency on SSH development and the diuretic antihypertension effect in CCKBRfl/fl villin-Cre mice. The CCKBRfl/fl villin-Cre mice with the high salt intake may serve as a stable model of salt-sensitive hypertensive induced by sodium overloading.

Establishment of a PCR-SSP method for the simultaneous amplification and identification of the presence of KIR genes / 中华医学遗传学杂志

OBJECTIVE@#To develop a polymerase chain reaction-sequence specific primer (PCR-SSP) method for simultaneous amplification and identification of the KIR genes among Chinese population.@*METHODS@#Peripheral blood samples from 132 healthy donors who had given blood at Shenzhen Blood Center from January 2015 to November 2015 were selected as the study subjects. Based on the polymorphism and single nucleotide polymorphism (SNP) information of high-resolution KIR alleles in the Chinese population and the IPD-KIR database, specific primers were designed to amplify all the 16 KIR genes and the 2DS4-Normal and 2DS4-Deleted subtypes. The specificity of each pair of PCR primers was verified by using samples with known KIR genotypes. During PCR amplification of the KIR gene, co-amplification the fragment of human growth hormone (HGH) gene by multiplex PCR was used as the internal control to prevent false negative results. A total of 132 samples with known KIR genotypes were randomly selected for blind inspection to verify the reliability of the developed method.@*RESULTS@#The designed primers can specifically amplify the corresponding KIR genes, with clear and bright bands for the internal control and KIR genes. The results of detection are fully consistent with the known results.@*CONCLUSION@#The KIR PCR-SSP method established in this study can yield accurate results for the identification of the presence of KIR genes.

Status of 3D Printing Technology for Preparing Bioceramic Materials / 中国医疗器械杂志

3D printing technology has great advantages in small batch and personalized customization, so it has attracted much attention in the biomedical field. The consumables available for 3D printing include polymer, metal, ceramic and derived materials. Biomedical ceramics, with high melting point and poor toughness, are the most difficult materials to be used in 3D printing. The progress of 3D printing ceramic preparation process using ceramic powder, ceramic slurry, ceramic wire, ceramic film and other different raw materials as consumables are reviewed, and the surface roughness, size, density and other parameters of ceramics prepared by SLS, 3DP, DIW, IJP, SL, DLP, FDM, LOM and other different processes are compared. The study also summarizes the clinical application status of 3D printed bioceramics in the field of hard tissue repair such as bone tissue engineering scaffolds and dental prostheses. The SL ceramic additive manufacturing technology based on the principle of UV polymerization has better manufacturing precision, forming quality and the ability to prepare large-size parts, and can also endow bioceramics with better biological properties, mechanical properties, antibacterial, tumor treatment and other functions by doping trace nutrients and surface functional modification. Compared with the traditional subtractive manufacturing process, the bioceramics prepared by 3D printing not only have good mechanical properties, but also often have better biocompatibility and osteoconductivity.

Knowledge, attitudes and practice regarding protection against COVID-19 among primary and middle students in Hangzhou / 中国学校卫生

Objective@#To analyze knowledge, attitudes and practice regarding protection against COVID-19 among primary and middle school students in Hangzhou and to provide a scientific basis for schools to carry out targeted prevention and control measures.@*Methods@#Anonymous network sampling survey was carried out through the questionnaire star, and a total of 14 216 subjects from primary and middle school in Hangzhou were recruited to fill in the questionnaire regarding knowledge, attitudes and practice of COVID-19 from March 3 to March 7, 2020.@*Results@#Primary and middle school students showed high awareness rate of transmission (85.83%) and incubation period (77.44%), but lower awareness on symptoms (44.70%) of COVID-19. The practice of wearing masks, cough etiquette and correct hand washing were 97.27%, 88.01% and 91.82%, respectively. The protective practice among primary and middle school students were generally good, 91.21% of them were at moderate level or above. 83.91% of primary and secondary school students reported worries about infection of COVID-19, and 55.42% of primary and secondary school students were anxious about returning to school. Primary school students and rural students were more anxious about returning to school(χ 2=46.66, 26.70, P<0.05).@*Conclusion@#The primary and middle school students in Hangzhou have a relatively good level of knowledge and practice concerning COVID-19. Yet, it is necessary to carry out targeted health education and strengthen mental health education for primary and middle school students.

Influencing factors for depressive symptoms in the elderly aged 65 years and older in 8 longevity areas in China / 中华流行病学杂志

To analyze influencing factors for depressive symptoms in the elderly aged 65 years and older in 8 longevity areas in China. We recruited 2 180 participants aged 65 years and older in 8 longevity areas from Healthy Aging and Biomarkers Cohort Study, a sub-cohort of the Chinese Longitudinal Healthy Longevity Survey in 2017. Multivariate logistic regression analysis was performed to evaluate the relationships of socio-demographic characteristics, behavioral lifestyle, chronic disease prevalence, functional status, family and social support with depressive symptoms in the elderly. The detection rate of depression symptoms was 15.0 in the elderly aged 65 years and older in 8 longevity areas of China, and the detection rate of depression symptoms was 11.5 in men and 18.5 in women. Multivariate logistic regression analysis results showed that the detection rate of depressive symptoms was lower in the elderly who had regular physical exercises (=0.44, 95: 0.26-0.74), frequent fish intakes (=0.57, 95: 0.39-0.83), recreational activities (=0.65, 95: 0.44-0.96), social activities (=0.28, 95: 0.11-0.73) and community services (=0.68, 95: 0.50-0.93). The elderly who were lack of sleep (=2.04, 95: 1.49-2.80), had visual impairment (=1.54, 95: 1.08-2.18), had gastrointestinal ulcer (=2.97, 95: 1.53-5.77), had arthritis (=2.63, 95: 1.61-4.32), had higher family expenditure than income (=1.80, 95: 1.17-2.78) and were in poor economic condition (=4.58, 95: 2.48-8.47) had higher detection rate of depressive symptoms. The status of doing physical exercise, fish intake in diet, social activity participation, sleep quality or vision, and the prevalence of gastrointestinal ulcers and arthritis were associated with the detection rate of depressive symptoms in the elderly.

Influencing factors for depressive symptoms in the elderly aged 65 years and older in 8 longevity areas in China / 中华流行病学杂志

Objective@#To analyze influencing factors for depressive symptoms in the elderly aged 65 years and older in 8 longevity areas in China.@*Methods@#We recruited 2 180 participants aged 65 years and older in 8 longevity areas from Healthy Aging and Biomarkers Cohort Study, a sub-cohort of the Chinese Longitudinal Healthy Longevity Survey in 2017. Multivariate logistic regression analysis was performed to evaluate the relationships of socio-demographic characteristics, behavioral lifestyle, chronic disease prevalence, functional status, family and social support with depressive symptoms in the elderly.@*Results@#The detection rate of depression symptoms was 15.0% in the elderly aged 65 years and older in 8 longevity areas of China, and the detection rate of depression symptoms was 11.5% in men and 18.5% in women. Multivariate logistic regression analysis results showed that the detection rate of depressive symptoms was lower in the elderly who had regular physical exercises (OR=0.44, 95%CI: 0.26-0.74), frequent fish intakes (OR=0.57, 95%CI: 0.39-0.83), recreational activities (OR=0.65, 95%CI: 0.44-0.96), social activities (OR=0.28, 95%CI: 0.11-0.73) and community services (OR=0.68, 95%CI: 0.50-0.93). The elderly who were lack of sleep (OR=2.04, 95%CI: 1.49-2.80), had visual impairment (OR=1.54, 95%CI: 1.08-2.18), had gastrointestinal ulcer (OR=2.97, 95%CI: 1.53-5.77), had arthritis (OR=2.63, 95%CI: 1.61-4.32), had higher family expenditure than income (OR=1.80, 95%CI: 1.17-2.78) and were in poor economic condition (OR=4.58, 95%CI: 2.48-8.47) had higher detection rate of depressive symptoms.@*Conclusion@#The status of doing physical exercise, fish intake in diet, social activity participation, sleep quality or vision, and the prevalence of gastrointestinal ulcers and arthritis were associated with the detection rate of depressive symptoms in the elderly.

Effect of rational emotive therapy on negative emotion in advanced schistosomiasis patients with repeated hospitalization / 中国血吸虫病防治杂志

Objective To examine the effect of rational emotive therapy on negative emotions among advanced schistosomiasis patients with repeated hospitalizations. Methods A total of 97 advanced schistosomiasis patients with anxiety and depressive emotions that were hospitalized in Xiangyue Hospital of Hunan Institute of Schistosomiasis Control for three times or more were enrolled, and given rational emotive therapy for 4 weeks in addition to routine nursing care. The scores for anxiety, depression and quality of life were estimated in patients before and after the rational emotive therapy using the Self-Rating Anxiety Scale (SRS), the Self-Rating Depression Scale (SDS) and WHOQOL-BREF Form. Results The SAS and SDS scores were significantly lower 4 weeks following rational emotive therapy than before the intervention (SAS score, 45.40 ± 7.77 vs. 59.25 ± 9.29, t = 14.021, P < 0.01; 51.48 ± 8.01 vs. 63.93 ± 9.59, t = 12.991, P < 0.01). The percentages of patients with moderate and severe anxiety and depression were significantly lower 4 weeks following rational emotive therapy than before the intervention (P < 0.01), and the scores for each item in the quality of life were all significantly greater 4 weeks following rational emotive therapy than before the intervention (P < 0.01). Conclusion Rational emotive therapy may improve the negative emotions and the quality of life of advanced schistosomiasis patients with repeated hospitalizations.

Effect of Modified Ditantang on Autophagy and Relevant Proteins in Brain Cells of Rats with Cerebral Ischemia Reperfusion Injury / 中国实验方剂学杂志

Objective:To investigate the effect of modified Ditantang on autophagy and relevant proteins in brain cells of rats with cerebral ischemia reperfusion injury. Method:The cerebral ischemic reperfusion (CIR) injury model in rats was built by reversible middle cerebral artery occlusion artery suture of middle cerebral embolism method, and randomly divided into sham group, model group, high-dose modified Ditantang group(H-dose), low-dose modified Ditantang group (L-dose, 0.384 g·kg-1) and PLXT group (0.1 g·kg-1). Sham and model groups were given normal saline by gastric perfusion, H-dose and L-dose groups were given modified Ditantang, and the PLXT group were given Piracetam tablets, intragastric volume 10 mL·kg-1. The treatment lasted for 7 d. Within 24 hours after administration, the histopathological examination was performed, the volume of cerebral infarction, neuronal apoptosis and serum levels of inflammatory factors were compared, and the expressions of autophagy related microtuble-associated protein 1 light chain 3(LC3)Ⅱ, Beclin1, B-cell lymphoma-2(Bcl-2) and p62 in brain tissues were determined. Result:Cells and blood vessel necrosis, neuron swelling and interstitial edema were observed in model group, a few neurons died, edema was reduced, swelling of nerve cells was alleviated in H-dose, L-dose and PLXT groups. The volume of cerebral infarction and neuronal apoptosis in H-dose, L-dose and PLXT groups were lower than those in model group (Pα, intedeukin (IL)-2 and IL-8 in H-dose, L-dose and PLXT groups were lower than those in model group (PPConclusion:Modified Ditantang can improve brain injury and interfere with autophagy after MCAO/R, alleviate inflammation, and regulate autophagic activity, which may be related to the down-regulation of expressions of LC3 Ⅱ, Beclin1 and the up-regulation of expression of p62.

Effect of reactive oxygen species on 1,4-benzoquinone-induced mitophagy / 预防医学

Objective To investigate whether the metabolite of benzene, 1, 4-benzoquinone (1, 4-BQ) , can activate PINK1/Parkin-mediated mitocphagy and the role of reactive oxygen species (ROS) in 1, 4-BQ induced mitophagy in vitro. Methods Human promyelocytic leukemia cells HL60 were used as the test cells, and were divided into control group, 1, 4-BQ group (10 μM 1, 4-BQ treated cells for 24 h), NAC group (5 mM antioxidant N-acetyl cysteine treated cells for 24 h) and 1, 4-BQ+NAC group (5 mM NAC preincubated for 1 h prior to the treatment with 10 μM 1, 4-BQ for 24 h) . The ultra structure of the cells were observed by transmission electron microscopy (TEM), and the expression of mitophagy related protein LC3, PINK1 and Parkin were detected by Western blot, and the intracellular ROS content was determined by DCFH-DA staining. Results The mitochondria in the control group showed a normal rod-shaped structure with clear mitochondrial cristae, while in the 1, 4-BQ group, the mitochondria showed a swollen structure with less mitochondrial cristae, and typical double-membrane mitophagosomes were observed. LC3-Ⅱ/LC3-Ⅰ ratio, the expression of PINK1, Parkin protein and ROS content in 1, 4-BQ group were increased compared with the control group (P <0.05) , and this increase was markedly blocked by the co-treatment of 1, 4-BQ and NAC (P <0.05) . Conclusion The 1, 4-BQ can induce PINK1/Parkin-mediated mitophagy and ROS plays a significant role in 1, 4-BQ-induced mitophagy.

Study on corneal edema related factors after phacoemulsification in patients with diabetic cataract / 国际眼科杂志(Guoji Yanke Zazhi)

Cataract is the first ophthalmological blinding eye disease. In recent years, phacoemulsification has become the preferred method for the treatment of cataract due to its short time and small damage, which is widely used by ophthalmologists. With the continuous improvement of technology, serious complications caused by phacoemulsification become less and less. But the phenomenon of postoperative corneal edema is not uncommon. The incidence of corneal edema is especially high in patients with diabetic cataracts. This paper reviewes the concept of corneal edema, pathogenesis and the related factors of corneal edema after phacoemulsification in diabetic cataract patients.

Genetic polymorphisms of KIR2DS4 gene among ethnic Hans from southern China / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To study genetic polymorphisms of the KIR2DS4 gene among ethnic Hans from southern China.</p><p><b>METHODS</b>Genomic DNA was isolated from 306 unrelated individuals and amplified with KIR2DS4-specific PCR primers. KIR2DS4-positive samples were genotyped for the entire coding sequence by sequencing-based typing (SBT). Assignment of allelic genotypes was accomplished by using Assign 3.5 software. For samples with inconclusive SBT results, RT-PCR products covering the entire coding sequence of the KIR2DS4 gene were subjected to cloning and haplotype sequencing.</p><p><b>RESULTS</b>Among all tested samples, 297 were demonstrated to have carried the KIR2DS4 framework gene. For KIR2DS4-positive samples subjected to SBT for the entire coding sequences, no background was observed with the obtained sequences. Three of the seven identified alleles were of novel types, which were officially named by the KIR subcommittee of the World Health Organization Nomenclature Committee for Factors of HLA System. The observed frequencies for the 7 alleles were KIR2DS4*00101 (78.8%), *003 (10.5%), *004 (16.0%), *010 (23.2%), *017 (0.3%), *00105 (0.3%) and *018 (0.7%), respectively. Allele KIR2DS4*007 was not found. The overall frequency for normal cell-surface expression KIR2DS4 alleles including 2DS4*00101, *017 and *00105 was 79.4%, and that for non cell-surface expression alleles including 2DS4*003, *004, *010 and *018 was 50.4%. The ratio between the two was 1.6:1.</p><p><b>CONCLUSION</b>The present study has elucidated the allelic diversity of KIR2DS4 among ethnic Hans from southern China, which may provide valuable data for transplantation as well as studies on KIR-associated disease and evolution.</p>

Application of SWOT analysis in medical equipment maintenance and management / 中国医学装备

Objective: To observe and summarize the routine maintenance situation, and research relevant countermeasure and provide the optimal solution based on the problems in maintenance of medical equipment. Methods: To adopt SWOT method to analyze the problem of equipment maintenance, and make effective countermeasures by using relevant statistical methods. Results: The SWOT method that was applied in maintenance work has improved accuracy of maintenance work for equipment, and increased operation rate of equipment and serviceability rate, at the same time, the satisfied degree of medical staffs and patients has been increased. Conclusion: Through SWOT method to analyze the situation of maintenance for equipment, the work key points can be effectively improved, and the blindness and dead ends of equipment maintenance management can be found. Therefore, this method can reduce the labour intensity of maintenance staffs, increase work efficiency, and provide essential guarantee for medical work of hospital.

Development of rain gear for stretcher cart / 医疗卫生装备

Objective To develop a rain gear for the stretcher cart to facilitate casualty transport during rainy days. Methods The rain gear was designed with emphases on rain proof, portability, compactness and etc, which was composed of multi fixing and guiding slots and multi metal racks at the cart as well as the rain-proof raincloth and hanger. Results The rain gear behaved well in rain proof, deployment and withdrawal, and enhanced the patient satisfaction and medical staff's efficiency greatly. Conclusion The rain gear gains advantages in design, structure and safety, and thus is worthy promoting practically.

Enhanced absorption and inhibited metabolism of emodin by 2, 3, 5, 4'-tetrahydroxystilbene-2-O-β-D-glucopyranoside: Possible mechanisms for Polygoni Multiflori Radix-induced liver injury / 中国天然药物

Polygoni Multiflori Radix (PMR) has been commonly used as a tonic in China for centuries. However, PMR-associated hepatotoxicity is becoming a safety issue. In our previous in vivo study, an interaction between stilbenes and anthraquinones has been discovered and a hypothesis is proposed that the interaction between stilbene glucoside-enriching fraction and emodin may contribute to the side effects of PMR. To further support our previous in vivo results in rats, the present in vitro study was designed to evaluate the effects of 2, 3, 5, 4'-tetrahydroxystilbene-2-O-β-D-glucopyranoside (TSG) on the cellular absorption and human liver microsome metabolism of emodin. The obtained results indicated that the absorption of emodin in Caco-2 cells was enhanced and the metabolism of emodin in human liver microsomes was inhibited after TSG treatment. The effects of the transport inhibitors on the cellular emodin accumulation were also examined. Western blot assay suggested that the depressed metabolism of emodin could be attributed to the down-regulation of UDP-glucuronosyltransferases (UGTs) 1A8, 1A10, and 2B7. These findings definitively demonstrated the existence of interaction between TSG and emodin, which provide a basis for a better understanding of the underlying mechanism for PMR-induced liver injury.

Discussion on battery management of ECG monitor in grade A tertiary hospital / 医疗卫生装备

Objective To discuss the battery management of ECG monitor to enhance its benefits.Methods The application of ECG monitor battery in all the departments was analyzed,and a management scheme was proposed that executed proper supplying in the nurse station and centralized allocation in leasing center.Results The proposed scheme decreased the failure risks of the battery and saved the cost of the departments.Conclusion Battery management concept can be applied to other types of medical equipment so as to further optimize medical equipment management mechanism in the medical facility.

Discussion on battery management of ECG monitor in grade A tertiary hospital / 医疗卫生装备

Objective To discuss the battery management of ECG monitor to enhance its benefits.Methods The application of ECG monitor battery in all the departments was analyzed,and a management scheme was proposed that executed proper supplying in the nurse station and centralized allocation in leasing center.Results The proposed scheme decreased the failure risks of the battery and saved the cost of the departments.Conclusion Battery management concept can be applied to other types of medical equipment so as to further optimize medical equipment management mechanism in the medical facility.

Expression of RUNX2 and MDM21 in rats with periodontitis under chronic intermittent hypoxia

Objective To discuss the expression of RUNX2 and MDM21 in rats with periodontitis under the chronic intermittent hypoxia. Methods A total of 32 SD healthy rats were randomly divided into four groups, with 8 rats in each group. The molecular biological techniques of immunohistochemistry, RT-PCR and Western blotting were employed to detect the effect of different hypoxia time (0, 6, 12, 24 and 48 h) and different concentrations of hypoxia (0.000, 0.001, 0.010, 0.060 and 0.100 ppm) on the expression of RUNX2 and MDM21 in rats of four groups. Results The expression of RUNX2 and MDM21 in each group was significantly higher than the one at other concentrations when the concentration was 0.010 ppm, with the statistical difference (P normoxic periodontitis group > hypoxia control group > hypoxia periodontitis group under the action with the concentration of 0.010 ppm for 12 h, but there was no significant difference for the comparison among groups (P > 0.05). Conclusions The condition of chronic intermittent hypoxia can reduce the expression of RUNX2 and MDM21 in rats with periodontitis and aggravate the damage of periodontal bone.

Expression of RUNX2 and MDM21 in rats with periodontitis under chronic intermittent hypoxia

OBJECTIVE@#To discuss the expression of RUNX2 and MDM21 in rats with periodontitis under the chronic intermittent hypoxia.@*METHODS@#A total of 32 SD healthy rats were randomly divided into four groups, with 8 rats in each group. The molecular biological techniques of immunohistochemistry, RT-PCR and Western blotting were employed to detect the effect of different hypoxia time (0, 6, 12, 24 and 48 h) and different concentrations of hypoxia (0.000, 0.001, 0.010, 0.060 and 0.100 ppm) on the expression of RUNX2 and MDM21 in rats of four groups.@*RESULTS@#The expression of RUNX2 and MDM21 in each group was significantly higher than the one at other concentrations when the concentration was 0.010 ppm, with the statistical difference (P  normoxic periodontitis group > hypoxia control group > hypoxia periodontitis group under the action with the concentration of 0.010 ppm for 12 h, but there was no significant difference for the comparison among groups (P > 0.05).@*CONCLUSIONS@#The condition of chronic intermittent hypoxia can reduce the expression of RUNX2 and MDM21 in rats with periodontitis and aggravate the damage of periodontal bone.