BACKGROUND: Neoadjuvant therapy enhances the possibility of achieving radical resection and improves the prognosis for locally advanced gastric cancer (GC). However, there is a lack of evidence regarding the optimal extent of resection for locally advanced proximal GC after neoadjuvant therapy. METHODS: In this study, 330 patients underwent resection in Peking University Cancer Hospital, with curative intent after neoadjuvant therapy for histologically confirmed proximal GC from January 2009 to December 2022. RESULTS: In this study, 45 patients underwent proximal gastrectomy (PG), while 285 underwent total gastrectomy (TG). After propensity-score matching, 110 patients (71 TG and 39 PG) were included in the analysis. No significant differences between PG and TG regarding short-term outcomes and long-term prognosis were found. Specifically, PG demonstrated comparable overall survival to TG ( P = 0.47). Subgroup analysis revealed that although not statistically significant, PG showed a potential advantage over TG in overall survival for patients with tumor-long diameters less than 4 cm ( P  = 0.31). However, for those with a long diameter larger than 4 cm, TG had a better survival probability ( P  = 0.81). No substantial differences were observed in baseline characteristics, surgical safety, postoperative recovery, and postoperative complications. CONCLUSION For locally advanced proximal GC with objective response to neoadjuvant therapy (long diameter <4 cm), PG is an alternative surgical procedure.
Humans ; Stomach Neoplasms/drug therapy* ; Gastrectomy/methods* ; Neoadjuvant Therapy/methods* ; Male ; Female ; Middle Aged ; Propensity Score ; Aged ; Adult ; Retrospective Studies

Objective:Clamping bilateral renal arteries with refined surgical methods to establish the rat renal ischemia-reperfusion injury (RIRI) model, and study the protective mechanism of ischemic preconditioning renal (IPC) tubular cell-derived exosomes in RIRI.Methods:25 female Sprague Dawley (SD) rats were divided into sham group, model group, inactivated group, normoxic group, IPC group. In the sham operation group, after bilateral renal arteries were dissociated, the back incision was disinfected and closed. The model group established RIRI model; RIRI models were established in inactivated group, normoxia group and IPC group, and then 200 μg of inactivated exosomes, normal exosomes and IPC exosomes were injected into the caudal vein 24 hours after operation. Serum creatinine (Scr) and urea nitrogen (BUN) levels were detected. The pathological changes of renal tissue were observed under light microscope. Transmission electron microscopy (TEM) was used to observe the shape and size of renal tubular exosomes. Nanoparticle tracking analysis (NTA)was used to detect the concentration and size of renal tubular exosomes.Results:Compared with the sham group, the Scr and BUN levels in the model group were significantly elevated ( P<0.01). Renal pathological changes in the model group showed damaged of the tubular structure, necrosis and shedding of tubular epithelial cells, and a large number of inflammatory cells accumulated in the renal interstitial tissue with varying degrees of edema. Compared with the inactivated group, the Scr and BUN levels significantly decreased in the normoxic group and IPC group ( P<0.01). Renal pathological changes in the normoxic group and IPC group showed that the renal tubular cell necrosis alleviated, inflammatory was reduced, the improved edema. Compared with the normoxic group, the Scr and BUN levels in the IPC group were further reduced ( P<0.01). Renal pathological changes in the IPC group showed that the inflammatory cells were significantly reduced, the cell edema was significantly improved, and the cell apoptosis was significantly reduced. Conclusions:Clamping bilateral renal arteries with refined surgical methods is the main and optimal way to build a rat model of RIRI. IPC tubular cell-derived exosomes have protective and repair effects on RIRI.

Objective To explore the effect of immunogenicity of freeze-dried bone allograft on different in vitro experimental models. Methods The lymphocytes were obtained respectively from 10 healthy young human volunteers, 10 Balb/c and 10 C57 mice and 10 New Zealand rabbits. The experiment was carried out in 6 groups: positive control group (PHA/ConA+lymphocyte), negative control group (Hydroxyapatite powder + lymphocyte), allogeneic bone group A (Freeze-dried bone powder 2. 0 g/L + lym-phocyte), allogeneic bone group B (Freeze-dried bone powder 1.0 g/L + lymphocyte), allogeneic bone group C (Freeze-dried bone powder 0.5 g/L + lymphocyte), and negative control group (culture solution + lym-phocyte). Lymphocyte transformation test (Alamarblue) was conducted to culture the 6 kinds of experimental materials in vitro. After 72 hours, samples were scanned with ELISA muhiscan at wave lengths 570 nm and 600 nm to fetal the light absorption value. Pearson analyses were performed 10 determine the relationships a-mong the 3 animals and 1 human groups and find out which animal would be highly correlated to human. Results In the human and Balb/c mice lymphocyte transformation tests, there was no significant difference (P > 0.05) between allogeneic bone groups A, B, C and negative control group (HA) ; but there was sig-nificant difference (P < 0.001) between allogeneic bone groups A, B, C and positive control group (PHA/ConA); there was no significant difference between the 3 allogeneic bone groups (P > 0.05). There was no significant difference among the 6 groups of C57 mice and New Zealand rabbits (P > 0.05). The coefficient r between Balb/c mice and human groups was 0.959, P = 0.003, showing a highly positive correlation. The coefficient r between C57 mice and human groups was 0.527, P = 0.283, while the coefficient r between New Zealand rabbits and human groups was 0.866, P =0.026. Conclusions The immunogenicity of freeze-dried bone powder in this experiment may not be sufficient enough to induce significanrt immunologic response. Balb/c mice may be preferable for immunogenicity related experiments.

According to the related standards, an in vitro corrosion fatigue testing of coronary stents was designed. The stents were fixed in the latex tubes, which were full of 0.9% saline solution, and radial stress was produced for simulating natural vessel. The accelerated fatigue test was performed with 4 x 10(8) cycles at a frequency of 60 Hz, which was equal to 10 years in vivo implantation. Twelve coronary stents made from stainless steel were adopted in the experiment. The bulk structure and surface morphology before and after testing were analysed by scanning electron microscopy. The structure damage and surface change caused by corrosion fatigue were identified and the probable reasons were proposed.
Biocompatible Materials ; chemistry ; Computer Simulation ; Corrosion ; Equipment Failure Analysis ; Humans ; Materials Testing ; Models, Cardiovascular ; Stainless Steel ; chemistry ; Stents ; Time Factors