BACKGROUND:Porous gradient hydroxyapatite/zirconia composite, which can adhere to a variety of cel s, such as osteoblasts, bone marrow mesenchymal stem cel s and chondrocytes, can induce and promote fracture healing or replace bone defects. OBJECTIVE:To review the development and application of porous gradient hydroxyapatite/zirconia composite in bone tissue engineering. METHODS:Articles related to porous gradient hydroxyapatite/zirconia composite in bone tissue engineering were retrieved in CNKI and PubMed databases (1971-01/2014-12). The key words were“porous bioceramic, bone tissue engineering, bone morphogenetic protein-2, induced pluripotent stem cel s”in Chinese and English, respectively. A total of 54 articles based on inclusion criteria and exclusion criteria were obtained for the review. RESULTS AND CONCLUSION:Porous gradient hydroxyapatite/zirconia composite can provide a scaffold to induce natural y forming bone growing to fil the three-dimensional pores, thus realizing the perfect integration of tissue-engineered bone material and host-bone tissue. As zirconia functions as an enhancer of hydroxyapatite, high-quality artificial bone materials, which have elastic modulus, fracture toughness and structure similar to human bone, can be prepared by adjusting the proportion and porosity of materials. Additional y, the new hydroxyapatite/zirconia foamed ceramics as tissue-engineered bone carrying bone morphogenetic protein-2/chitosan gel sustained release system and bone marrow mesenchymal stem cel s derived from induced pluripotent stem cel s wil be expected to increase bone formation and bone fusion rates significantly in the future.

Background: The detection rate of early gastric cancer has been increasing over recent decades, but synchronous multiple early gastric cancer (SMEGC) remains a challenge for endoscopists. It is important to improve the endoscopic diagnosis and treatment of SMEGC. Aims: To investigate the clinicopathological features of SMEGC and the correlation of its major and minor lesions. Methods: The medical records of 231 consecutive early gastric cancer patients treated by endoscopic submucosal dissection (ESD) in Beijing Friendship Hospital from Jun. 2013 to Dec. 2018 were retrospectively analyzed for comparing the clinical, endoscopic, pathological features and treatment outcome between solitary early gastric cancer (SEGC) and SMEGC. The relevance of major and minor lesions of SMEGC in endoscopic and pathological features was also analyzed. Results: Of the 231 early gastric cancer patients, 16 (6.9%) were SMEGC (34 lesions). The gender, age, and family history of GI tumors were comparable between SEGC and SMEGC (P>0.05). Furthermore, lesions of these two groups did not differ in tumor size, vertical location, histological differentiation, depth of invasion, and mucosal background (P>0.05). With respect to horizontal location and macroscopic type, SMEGC lesions were more often located in posterior wall (38.2%) and presented as elevated type (47.1%) as compared with SEGC lesions (P<0.05). All SMEGC lesions were differentiated type. The major and minor lesions of SMEGC were correlated in characteristics of macroscopic type (r=0.658, P<0.05) and histological differentiation (r=0.489, P<0.05), the concordance rates of these two aspects and depth of invasion were 68.8%, 81.2%, and 87.5%, respectively. The mucosal background of major and minor lesions was identical. The curative resection rates were comparable between SEGC and SMEGC (86.0% vs. 85.3%, P>0.05). Conclusions: SMEGC and SEGC have similar clinicopathological features. The major and minor lesions of SMEGC are consistent in characteristics of macroscopic type, histological differentiation, depth of invasion, and mucosal background. ESD is a feasible treatment for SMEGC.

Objective:To investigate the association of single nucleotide polymorphisms (SNPs) of receptor-associated protein at the synapse ( rapsyn ) with myasthenia gravis ( MG ).Methods: The genomic DNA was extracted from peripheral blood cells , sampled from 132 patients with MG and 153 control individuals.The 8 exons of rapsyn gene were amplified by PCR ,then the products of PCR sequenced directly.Each sequence was compared with wild-type rapsyn gene , and the association between mutation and clinical symptoms of MG analysed.Results:No mutation was found in the exons 1,2,4,5,6,7,and 8 of rapsyn gene both in MG patients and control group compared with the wild-type rapsyn gene.However,a new SNP,L222R[CTG>CGG(2)] or T665G,was found in exon-3.The allele and genotype frequencies of SNP L 222R met Hardy-Weinberg genetic equilibrium (P>0.05),indicating the group repre-sentativeness.The allele frequencies of G were not statistically different between patient and control groups ( P>0.05 ).There were differences in the 3 genotypes TT , TG and GG between patient ( 42.4% vs 48.5% vs 9.1%) and control ( 49.0% vs 33.3% vs 17.6%) groups ( P<0.05 ).The genotype frequencies of GG were statistically higher in control group than that in patient group , showing a recessive model of inheritance.Conclusion: The SNPs in the rapsyn gene are associated with MG in this study.L222R ( T665 G) is a new SNP found and allele G might be a protective factor for MG.

Objective To investigate the correlation between serum bicarbonate level and cardiovascular events in peritoneal dialysis(PD)patients.Methods The data of PD patients who underwent PD catheterization and were followed up regularly until March 31,2023 were retrospectively collected.The included patients were divided into low bicarbonate group and normal bicarbonate group according to the time-averaged serum bicarbonate level.The incidence of cardiovascular events(including coronary heart disease,heart failure,stroke,peripheral vascular dis-ease,death related to cardiovascular surgery or death due to aneurysm dissection or rupture,fatal pulmonary em-bolism,or death from other or unknown cardiovascular causes)was compared between the two groups and the risk factors for cardiovascular events were analyzed.Results At the end of follow-up,a total of 110 PD patients were included,and 34 patients had cardiovascular events.Compared with the normal bicarbonate group,the low bicar-bonate group had a higher incidence of cardiovascular events.Univariate Cox regression analysis showed that the risk of cardiovascular events in the low bicarbonate group was 4.197 times higher than that in the normal bicarbon-ate group(95％CI=2.115-8.331,P＜0.001).After adjusting for multiple confounding factors,the risk of car-diovascular events in the low bicarbonate group was 3.506 times higher than that in the normal bicarbonate group(95％CI=1.709-7.193,P=0.001).The results of multivariate competing risk model showed that the risk of cardiovascular events in the low bicarbonate group was 3.801 times higher than that in the normal bicarbonate group(95％CI=1.920-7.525,P＜0.001).Conclusion Low serum bicarbonate level is closely related to the oc-currence of cardiovascular events in patients with PD,and it is an independent risk factor for cardiovascular events in patients with PD.

Objective:To investigate the clinical, endoscopic and pathological characteristics of early Barrett esophageal adenocarcinoma (BEA) and to evaluate the treatment efficacy of endoscopic submucosal dissection (ESD).Methods:Data of 13 patients who were diagnosed as early BEA and treated by ESD in Beijing Friendship Hospital from November 2015 to June 2018 were retrospectively analyzed, including clinical data, endoscopic manifestations and pathological information.Results:Out of 13 patients, 10 were male. One had underlying long-segment Barrett esophagus (LSBE), 6 had short-segment Barrett esophagus (SSBE), and 6 had super short-segment Barrett esophagus (less than 1 cm). Two arose from circumferential Barrett esophageal (BE) and 11 from tongue-like BE. Ten lesions were located on the right anterior side wall (12-2 o′clock) of the esophagogastric junction (EGJ), and 12 lesions were superficial type (0-Ⅱ). ESD was successfully conducted in all the patients without any complication. The en bloc and curative resection rate was 100% (13/13) and 92% (12/13), respectively. Pathology examination found 9 well-differentiated adenocarcinoma and 10 intramucosal cancer. No recurrence was detected in 11 patients during follow-up of 3.3-29.3 months.Conclusion:Early BEA tends to occur in elderly male, and mostly originated from non-LSBE and tongue-like BE. Most lesions are superficial type and located on the right anterior side wall of EGJ. In pathology, most lesions are well-differentiated adenocarcinoma and limited to the mucosa. ESD is a safe and efficient treatment for BEA.

Objective:To evaluate the efficacy and safety of SPOT (GI Supply, USA), a new carbon-based permanent marker approved by the Food and Drug Administration (FDA), in the endoscopic marking for gastrointestinal lesions.Methods:A total of 115 patients with gastrointestinal lesions who underwent endoscopic treatment or surgery in Beijing Friendship Hospital or Beijing Chao-Yang Hospital from April 2019 to November 2019 were enrolled in the study. SPOT was used to mark the lesions, and marking points were found during endoscopic treatment or surgery to calculate the effective marking rate by single-group target value method. Adverse events after marking were recorded, and the changes of blood routine test, liver and kidney functions before and after marking were compared.Results:The effective rate of endoscopic marking with SPOT was 99.13% (114/115). The longest marking time was 57 days. There was no puncture of intestinal wall or injection into abdominal cavity during the marking process. One patient developed mild fever after marking. The incidence of adverse events was 23.48% (27/115), which were all unrelated to the test equipment. There was no significant difference in blood routine tests or liver and kidney functions before and after marking ( P>0.05). Conclusion:SPOT produced by GI Supply can effectively mark gastrointestinal lesions without serious adverse events, which meets the requirements of clinical use.