AIM:Mesenchymal cells migrating towards fracture site and differentiating into chondrocytes and osteoblasts is the key process during fracture healing. This article is aimed to observe the changes of the expression of bone morphogenetic protein(BMP)-2 in the early stage of tibia fracture in osteoporotic rats so as to evaluate the reason of delayed fracture healing in osteoporotic rats. METHODS:The experiment was conducted at the Key Laboratory for Oral Biomedical Engineering of Ministry of Education from August 2005 to October 2006. ①Sixty-four 6-month-old female SD rats were randomly divided into ovariectomized(OVX) group and control group with 32 in each group. ②The rats in the OVX group underwent ovariectomy to establish type Ⅰ osteoporotic models. A small quantity of fat tissues was removed in the control group. Three months later,standardized tibia fracture was introduced. ③Eight rats were selected at days 7,14,21 and 28 after operation in the two groups. Some soft tissues around tibia and broken ends of fractured bone,bony callus,cortical bone and medullary canal were collected and treated with histological analysis,immunohistochemical staining,semi-quantitative reverse transcription-polymerase chain reaction(RT-PCR),respectively. RESULTS:①Histological analysis showed membrane bone formation and endochondral bone. A mass of chondrocytes appeared in bony callus of the OVX group at days 21 and 28 after operation. ②The results of immunohistochemical staining showed that mean absorbance(A) of BMP-2 was higher in the control group than the OVX group at days 7 and 14,but lower at day 21. ③The findings of RT-PCR revealed that BMP 2 level was higher in the control group than the OVX group at day 7,but lower at day 14. CONCLUSION:BMP-2 plays a key role in the early phase of bone callus formation during fracture healing. The declined and delayed expression of BMP-2 in osteoporotic rats may be an important reason for delayed fracture healing in osteoporotic rats.

The application of biological technology and the deepening of tumor research have effectively improved the level of tumor diagnosis, treatment and clinical outcome prediction. However, the specific mechanisms of tumorigenesis and development are still unclear, and tumor drug resistance has also become an urgent problem that needs to be solved to improve the clinical outcome of patients. Considerable studies have shown that the extrachromosomal DNA (ecDNA) can promote tumorigenesis, development and drug resistance. EcDNA is a looser, rounded form of DNA with unique genetic properties that carry specific genes and regulatory elements. This paper will discuss the biological characteristics, tumor-promoting mechanisms and drug resistance-facilitating of ecDNA.

BACKGROUND:Research on rough-surfaced implants has demonstrated similar survival rates for short and conventional-length implants. It is not clear whether ultrashort implant in limited alveolar bone of the posterior maxila can achieve good clinical results. OBJECTIVE:To evaluate the clinical effect of ultrashort implants in limited alveolar bone of the posterior maxila. METHODS:Eighteen patients with 21 ultrashort implants in limited alveolar bone of posterior maxila (the mean residual alveolar height=3.19 mm) were included in the study, including 10 males and 8 females, aged 25-68 years. At 12 months after restoration, the patients were detected with cone-beam CT to evaluate the osseointegration and marginal bone level around the implant. RESULTS AND CONCLUSION:Al the 18 patients completed the 12-month folow-up, and the 21 pieces of implants had good osseointegration. No soft tissue inflammation was found. At 12 months after restoration, the marginal bone height in the mesial and distal was (-0.21±0.78) mm and (-0.16±0.55) mm, respectively. Implant marginal bone changes in the mesial and distal had no statistical difference (P > 0.05). Ultrashort implants in limited alveolar bone of the posterior maxila can have good osseointegration, maintain the marginal bone mass around the implant, but stil need long-term clinical observation.

BACKGROUND:Many experiments and clinical studies have reported that venous blood, absorbable colagen sponge and rich fibrin clot, without the use of bone graft material, can al promote new bone formation; therefore, whether only transplanting concentrated growth factor in the maxilary sinus lift could effectively promote bone regeneration? OBJECTIVE: To conduct the maxilary sinus lift with concentrated growth factor as the graft material, and to observe the peri-implant bone level change. METHODS: Totaly 26 patients were involved, including 14 males and 12 females, aged 35-73 years. Maxilary sinus lift was conducted and autologous concentrated growth factor was taken as the graft material. Astra Tech implants were implanted simultaneously. Patients were divided into 6-12 months, 13-18 months and > 18 months groups according to the folow-up time. Patients were divided into≤ 5 mm, 5-7 mm, and≥ 7 mm groups according to the preoperative alveolar bone height. Patients were divided into≤ 2 mm, 2.0-3.0 mm, and≥3 mm groups according to the postoperative maxilary sinus lift height. The survival rate of implants and marginal bone level changes were observed during the folow-up. RESULTS AND CONCLUSION: Totaly 44 implants were implanted, of which 43 implants were considered as successful repair during the 6-18 months of postoperative folow-up. The survival rate of implants was 98%. There were no significant differences in the changes of mesial, distal and middle marginal bone levels between different folow-up time groups. The maxilary sinus lift with transplantation of concentrated growth factor resulted in a good osseointegration within 6-18 months post-operation. In addition, no significant differences were found in the changes of mesial, distal and middle marginal bone levels between different residual alveolar bone height groups, as wel as between different maxilary sinus lift height groups. It showed that the residual alveolar bone height and maxilary sinus lifting height had no significant effect on the peri-implant bone formation. Briefly, these findings demonstrate that the maxilary sinus lift with concentrated growth factor transplantation can result in a high survival rate of implants that are simultaneous implanted, and the alveolar bone around the implant is stable. But the long-term effect needs further observation.

We expressed B cell epitopes of dengue virus envelope protein and NS1 protein in prokaryotic cells,and purified and evaluated for its serological activities.A recombinant multi-epitope chimeric gene named rE including eight B cell epitopes was connected by linker peptide (EAAAK)2 and cloned into prokaryotic expression vector pET-28a(+),and transformed into E.coli BL21(DE3) cells for expression under induction of IPTG.The expressed recombinant protein was purified with 6× His purification media,and identified by SDS-PAGE and Western blot,and its antigenicity was analyzed by using an indirect ELISA assay.The recombinant expression vector pET28a-rE was constructed and expressed in BL21 (DE3) successfully,but the recombinant proteins mainly appeared as inclusion bodies.The target protein was obtained with high purity through the purification of affinity chromatography.SDS-PAGE and Western blot analysis showed that the molecular weight of fusion protein was in the expected line.The established indirect ELISA has high accuracy.This recombinant peptide antigen expressed in E.coli has good potential for serum testing.

Objective:To evaluate the efficacy and safety of 125I seeds implantation for lymph nodes metastasis (LNM) from radioactive iodine-refractory differentiated thyroid carcinoma (RAIR-DTC), and to verify the computer three-dimensional treatment planning system (TPS) from the dosimetry accuracy in assisting seeds implantation to treat LNM. Methods:Retrospective analysis was performed on 17 RAIR-DTC patients with LNM admitted to the General Hospital of Northern Theater Command from December 2016 to January 2019 (8 males, 9 females, median age 58 years). All patients underwent preoperative TPS planning design, CT-guided puncture and 125I seeds implantation (seed activity 14.8-25.9 MBq). The dosimetric results of postoperative validation were compared with those of preoperative planning, including the dosimetric parameters such as target volume before and after surgery and the dose received by 90% and 100% gross tumor volume (GTV) ( D90, D100), the percentage received by 100% and 150% of the prescription dose ( V100, V150), homogeneity index (HI). All patients underwent CT after 6 months to compare the LNM size, serum thyroglobulin (Tg) level, and the improvement of complications before and after treatment. Efficacies were divided into complete remission (CR), partial remission (PR), stable disease (SD), and progressive disease (PD). Paired t test or Wilcoxon signed rank test were used to analyze the data. Results:Among 17 patients, a total of 226 125I radioactive seeds were implanted. Among them, 1 achieved CR, 10 achieved PR, 4 were with SD, and 2 were with PD. The diameter of LNM was 1.40(0.65, 3.05) cm before treatment and was 0.40(0.21, 0.91) cm 6 months after treatment ( z=-3.95, P<0.05). The Tg before treatment was 23.50(20.94, 72.92) μg/L and was 8.90(3.20, 40.22) μg/L 6 months after treatment ( z=-5.009, P<0.001). Tg antibody were all negative. There were 90.90% (20/22) of patients had slightly lower D90 than the prescribed dose ((12 378.8±3 182.0) vs (12 497.8±1 686.4) cGy; t=0.251, P>0.05). The postoperative dose parameters D100 and V150 ((6 881.5±1 381.8) cGy, (58.5±18.4)%) were both lower than those of preoperative plan ((8 085.8±2 330.0) cGy, (66.5±17.7)%; t values: 8.913, 3.032, both P<0.05), and the remaining indicators were not significantly different from those of the preoperative plan ( t values: 0.251, 1.493, z values: from -1.604 to -0.593, all P>0.05). Conclusions:According to the TPS preoperative plan, 125I seeds implantation for treating RAIR-DTC LNM can achieve the expected dose distribution, and the short-term tumor local control is effective. It is a safe and effective treatment method.

Objective:To explore the clinical efficacy of 125I seeds implantation combined with transcatheter arterial chemoembolization (TACE) in the treatment of primary liver cancer. Methods:A retrospective analysis of data from 40 patients with primary liver cancer at the Northern Theater General Hospital from January 2018 to December 2020 (26 males, 14 females, age 41 to 82 years) was performed. Among them, 21 patients were in treatment group and underwent 125I seeds implantation combined with TACE treatment, while 19 patients were in control group and received TACE treatment. Alpha-fetoprotein (AFP) levels between the two groups were compared, effective rate and disease control rate (DCR) of the two groups were analyzed, and overall survival (OS) and progression-free survival (PFS) were observed. Data were analyzed by using Mann-Whitney U test, χ2 test, Kaplan-Meier method and log-rank test. Results:Two months after 125I seeds implantation, the effective rates of treatment group and control group were 76.19%(16/21) and 8/19, respectively ( χ2=4.83, P=0.028); the DCRs were 90.48%(19/21) and 11/19, respectively ( χ2=4.21, P=0.040). AFP levels in both groups decreased significantly, with treatment group showing a greater decrease rate (0.87(0.84, 0.90) and 0.66(0.65, 0.67); z=5.42, P<0.001). No serious adverse reaction was observed in either group. The median OS of treatment group and control group were 18.2 and 10.6 months, respectively ( χ2=10.98, P=0.037); the median PFS of the two groups were 8.4 and 6.1 months, respectively ( χ2=7.54, P=0.041). Conclusion:125I seeds implantation combined with TACE treatment can exert a synergistic and enhancing effect in the treatment of primary liver cancer.