Objective:To study the colonization ability of Streptococcus oligofermentans (S.oligofer-mentan)in the condition of high sucrose in oral cavity of rats.Methods:In this study,48 SPF-SD rats aged 21 days were selected.From 24th to 27th days,the rats were fed with water of antibiotic and fed with high glucose diet continuously.On the 28th day,the rats were divided into four groups randomly,12 rats per group.From the 28th day to 30th day,the first group (SMgroup)was inoculated with S.mutans,the second group (SO group)with S.oligofermentan,the third group (SO+SM group)with mixture of S. mutans and S.oligofermentan,the control group not with any bacteria.On the next day and the 10th day after inoculation of bacteria,the samples of dental plaque of the rats were acquired by scrubbing occlu-sal,buccal and lingual surfaces of bilateral mandibular molars with sterile swabs.The samples of SM group were inoculated on MSB and BHIS,of SO group on MSAE,of SO+SMgroup on MSB,MSAE and BHIS,of the control group on MSB and MSAE.S.mutans were screened and calculated on MSB,the suspected colonies of S.oligofermentan were screened and identified by the analysis of 16S rDNA.Re-sults:On the next day,the detection rate of S.oligofermentan was 33.3% (4/12)in the group of SO;in the group of SO+SM,the detection rate of S.oligofermentan was 0,the detection rate of S.mutans 100.00%,and the proportion of S.mutans 14.70%±4.53%;in the group of SM,the detection rate of S.mutans was 100.00%,the proportion of S.mutans 12.42%±4.27%.On the 10th day,in the group of SO,the detection rate of S.oligofermentan was 0;in the group of SO+SM,the detection rate of S.oligofermentan was 0,the detection rate of S.mutans 100.00%,and the proportion of S.mutans 15.78%±5.10%;in the group of SM,the detection rate of S.mutans was 100.00%,and the propor-tion of S.mutans 17.08%±5.75%.Conclusion:In the condition of the experiment where high glucose was maintained in the oral cavity in rats,S.oligofermentan appeared transiently and couldn’t colonize in the rats.

Objective:To compare the efficacies of robot-assisted unilateral and manual unilateral/bilateral puncture kyphoplasty (PKP) for the treatment of osteoporotic thoracolumbar fracture (OTLF).Methods:A retrospective cohort study was conducted to analyze the clinical data of 64 OTLF patients admitted to First Affiliated Hospital of Kunming Medical University from April 2021 to May 2022. The patients included 28 males and 36 females, aged 57-88 years [(74.5±5.6)years]. Fracture segments were 12 patients from T 1-T 9, 32 from T 10-L 2, and 20 from L 3-L 5. All the patients were treated with PKP. Among them, 25 patients underwent manual unilateral puncture (manual unilateral group), 18 patients underwent manual bilateral puncture (manual bilateral group), and 21 patients underwent robot-assisted unilateral puncture (robot-assisted unilateral group). The operation time, channel establishment time, intraoperative blood loss, intraoperative fluoroscopy times, bone cement injection volume, and bone cement spatial distribution score were compared among the three groups. The visual analogue score (VAS), Oswestry disability index (ODI) and Cobb angle of kyphosis were compared among the three groups before operation, at 3 days and 3 months after operation, and at the last follow-up. The incidence of complications was compared. Results:All the patients were followed up for 6-10 months [(7.0±0.9)months]. The operation time of the manual unilateral group was (30.2±6.1)minutes, which was shorter than (37.9±8.9)minutes of the robot-assisted unilateral group and (49.0±10.2)minutes of the manual bilateral group; the operation time of the robot-assisted unilateral group was markedly shorter than that of the manual bilateral group (all P<0.05). The channel establishment time of the robot-assisted unilateral group was (4.7±1.4)minutes, which was markedly shorter than (10.4±4.4)minutes of the manual unilateral group and (21.7±6.2)minutes of the manual bilateral group (all P<0.05). The intraoperative blood loss of the robot-assisted unilateral group was (23.8±7.2)ml, which was less than (34.3±7.7)ml of the manual unilateral group and (55.9±18.7)ml of the manual bilateral group (all P<0.05). The number of intraoperative fluoroscopy of the robot-assisted unilateral group was (12.1±2.5)times, which was markedly less than (21.2±5.9)times of the manual unilateral group and (39.6±9.5)times of the manual bilateral group (all P<0.05). The channel establishment time, intraoperative blood loss and intraoperative fluoroscopy times of the manual unilateral group were markedly shorter or less than those of the manual bilateral group (all P<0.05). The bone cement injection volume and bone cement distribution score of the robot-assisted unilateral group were (4.7±1.3)ml and (7.9±1.2)points, which were not statistically different from (5.7±1.3)ml and (8.7±1.1)points of the manual bilateral group (all P>0.05), but were markedly higher than (3.0±1.3)ml and (5.1±1.8)points of the manual unilateral group (all P<0.05). There were no significant differences in VAS, ODI and Cobb angle among the three groups at 3 days, 3 months after operation and at the last follow-up (all P>0.05), but which were all lower than those before surgery (all P<0.05). There were no significant differences in VAS, ODI and Cobb angle among three groups before operation, at 3 days, 3 months after surgery and at the last follow-up (all P>0.05). The complication rate was 4.8% (1/21) of the robot-assisted unilateral group, 32.0% (8/25) of the manual unilateral group, and 33.3% (6/18) of the manual bilateral group, with no significant difference between the manual unilateral group and the manual bilateral group ( P>0.05), but both of which was markedly higher than that of the robot-assisted unilateral group ( P<0.05). Conclusion:Robot-assisted unilateral puncture and manual unilateral/bilateral puncture PKP can both achieve satisfactory results for the treatment of OTLF, but robot-assisted unilateral puncture has shorter channel establishment time, less intraoperative blood loss and intraoperative fluoroscopy times, and lower complication rate.

OBJECTIVE: To observe the hepatic injury induced by combined exposure to diethylhexyl phthalate( DEHP) and bisphenol A( BPA) in rats and explore the mechanism of oxidative stress. METHODS: Thirty-two specific pathogen free healthy male SD rats were randomly divided into control group,DEHP(750 mg/kg body weight) group,BPA(100 mg/kg body weight) group and combined exposure group,with 8 rats in each group. The rats were gavaged once per day,7 days per week,for 6 weeks. The changes of liver organ coefficient and histopathology were observed. The activities of superoxide dismutase( SOD), glutathione peroxidase( GSH-Px) and the levels of hydrogen peroxide( H2 O2),malondialdehyde( MDA) were detected by spectrophotometry. The relative mRNA expression of antioxidant gene nuclear factor erythroid-2 related factor 2( Nrf2),heme oxygenase-1( HO-1),glutamate cysteine ligase catalytic subunit( Gclc),thioredoxin reductase( Txnrd),superoxide dismutase 3( Sod3) and glutathione peroxidase 1( Gpx1) in liver tissue were examined by real-time fluorescent quantitative polymerase chain reaction. RESULTS: The body weight of DEHP exposure group was lower than that of control group from the beginning of the 2 nd week( P < 0. 05),and the body weight of combined exposure group was lower than control group from the beginning of the 3 rd week( P < 0. 05). The liver mass and organ coefficients in DEHP group and combined exposure group were significantly higher than that of control group( P <0. 05). The results of pathology examination showed that there was necrosis of liver cells in DEHP group,vacuolar degeneration in cytoplasm of BPA group,and severe inflammatory cell infiltration in combined exposure group. The activity of SOD and GSH-Px of each exposure group was reduced( P < 0. 05),the H2 O2 level of each exposure group was increased(P < 0. 05),meanwhile the MDA level in the liver tissue of the BPA group and the combined exposure group increased compared with the control group( P < 0. 05). The relative mRNA expression of Nrf2,HO-1 and Gpx1 in each exposure group were decreased( P < 0. 05),the relative mRNA expression of Gclc,Txnrd and Sod3 in DEHP group and mixed exposure group were decreased compared with the control group( P < 0. 05). The relative mRNA expression of Nrf2,HO-1,Gclc,Txnrd and Sod3 in combined exposure group were decreased compared with the BPA group( P < 0. 05).CONCLUSION: Under the conditions of this study,DEHP and BPA alone or in combination could cause hepatic injury. The combined effect was greater than single effect. The effect of DEHP was greater than that of BPA. The liver injury induced by DEHP and BPA was related to Nrf2 signaling pathway.