OBJECTIVES: Color doppler flow imaging (CDFI) and cone-beam computed tomography (CBCT) were utilized to evaluate changes in mucosal vascular parameters and the osteogenic effects following guided bone regeneration (GBR) in the maxillary anterior region using trapezoidal or modified triangular flaps. METHODS: Patients undergoing single maxillary anterior dental implant surgery with GBR were randomly allocated into two groups: a trapezoidal flap group and a modified triangular flap group. After GBR surgery, the mucosal vascular parameters at the surgical site were assessed at various time intervals (preoperative, 2 h, 1 and 3 days, and 1, 2, and 4 weeks postoperative) using CDFI. In addition, the effects of bone augmentation were evaluated through the analysis of CBCT images obtained preoperatively, 2 h, and 6 months postoperative. RESULTS: The buccal mucosa in the edentulous area had a lower blood flow rate than the corresponding tooth in the same jaw, and the difference was statistically significant (P<0.001). The mucosal blood flow rate in the surgical area increased compared with that in the preoperative period. The peak flow rate was recorded at 2 weeks postoperatively and then decreased to levels comparable to those of the reference tooth. A statistically significant difference was observed between the two groups (P<0.05). The buccal alveolar ridge width of the implant platform was reduced by (1.3±0.9) mm in the trapezoidal flap group and (0.9±0.7) mm in the modified triangular flap group, respectively, at 6 months postoperatively, compared with 2 h postoperative. The buccal alveolar ridge width of the 5 mm from the implant platform was reduced by (0.9±0.6) mm and (0.3±0.6) mm, respectively. The buccal alveolar ridge width of the 10 mm from the implant platform was reduced by (0.6±0.8) mm and (0.2±0.6) mm, respectively. The height of the alveolar ridge was reduced by (1.9±1.4 ) mm and (1.4±1.3) mm. The change in graft volume was (136±78 ) mm³ and (114±85) mm³. However, the differences between the two groups were not statistically significant (P>0.05). CONCLUSIONS When a tooth is missing, blood flow to the buccal mucosa on the side of the missing tooth is reduced. The modified triangular flap group demonstrated superior microcirculation of blood flow in the operative area after GBR of the maxillary anterior teeth. Trapezoidal and modified triangular flaps achieved the anticipated bone augmentation during bone augmentation surgery in the maxillary anterior region, with no considerable effect on the changes in alveolar bone size parameters.
Humans ; Surgical Flaps/blood supply* ; Bone Regeneration ; Mouth Mucosa/blood supply* ; Cone-Beam Computed Tomography ; Osteogenesis ; Maxilla/surgery* ; Male ; Female ; Guided Tissue Regeneration, Periodontal/methods*

Clinical research coordinator (CRC) can improve the efficiency of clinical research, ensure the accuracy and reliability of the research process, as well as the standardized implementation of research projects and the safety of subjects. However, the CRCs dispatched by the site management organization have problems such as high liquidity, uneven quality, low work initiative, and high management costs. Since 2004, a research hospital in South China had started to employ CRCs by itself, exploring and forming three self-employed CRC management modes: hospital employ-hospital manage, researcher employ hospital manage, and researcher employ-third-party labor dispatch agency manage. The CRCs under hospital employ-hospital manage mode were recruited and selected by the hospital. The hospital established a labor relationship with CRC, and the hospital′s personnel department was responsible for salary distribution and promotion management of professional titles/positions. The relevant labor costs were borne by the hospital′s funds, and the salary standards were also formulated by the hospital. This type of CRC could participate in the promotion of health technology series titles. The CRCs under researcher employ-hospital manage mode were recruited and selected by the researcher. The hospital established a labor relationship with them. The relevant labor costs were borne by the research funding, and the researchers determined the specific salary standards for CRCs based on the salary guidance plan formulated by the hospital. These kind of CRCs could not be promoted to professional titles in hospitals. The CRCs under researcher employ-third-party labor dispatch agency manage mode were recruited and selected by researchers. The third-party labor dispatch agency established an employment relationship with them and provided personnel services. The relevant labor costs were borne by the research funding, and the researchers formulated their own salary standards. Such CRCs could not be promoted to professional titles in hospitals. As of July 2023, the number of self-employed CRCs in the hospital had reached 185, with 75.8% having a bachelor′s degree or above and an average work experience of 4.58 years. Among them, there were 26 people in the hospital hiring-hospital management mode, 45 people in the researcher hiring-hospital management mode, and 114 people in the researcher hiring-third-party labor dispatch agency management mode. These measures had fully released management efficiency, effectively met manpower needs, promoted rapid growth in the number of clinical research projects, and reduced management costs through third-party labor dispatch mode, which could provide references for CRC management in clinical trial institutions of China.

BACKGROUND:Gastric cancer stem cels involved in the neoadjuvant chemotherapy and conventional treatment are closely associated with relapse of gastric cancer. However, this conclusion has not yet been confirmed.
OBJECTIVE:To investigate the effects of gastric cancer stem cels in tumor invasion and metastasis and its effect on angiogenesis ability.
METHODS:We prepared nude mouse models of gastric cancer to isolate and culture gastric cancer stem cels. Harvested gastric cancer stem cels were detected in cel scratch test, ring test, inhibition rate test, cel migration test and tumorigenicity test.
RESULTS AND CONCLUSION:After 7 days of culture, the cels exhibited adherent growth but a lack of regularity that most cels were in a tadpole shape. In the cel scratch test, the scratch width was significantly different at 0 and 24 hours (P < 0.05). Under an inverted microscope, the cels were found to form a ring in the ring test. The 50% inhibiting concentration of gastric cancer stem cels induced by oxaliplatin was significantly lower than that induced by 5-fluorouracil (P < 0.05). The number of cels passing through the basilar membrane was significantly increased after cel migration (P < 0.05). After implantation of gastric cancer stem cels, the gastric tissue quality was significantly higher than that in normal nude mice of gastric cancer (P < 0.05). These findings indicate that gastric cancer stem cels responsible for tumor invasion and migration have stronger angiogenesis ability.