BACKGROUND:The self-renewal and multi-directional differentiation of pluripotent stem cells possess the potential to revolutionize people's understanding of biology,medicine,development,and disease.Stem cells play an important role in the early stage of embryonic development,and the study of them could be beneficial to understanding of the basic principles of biological development and tissue or organ formation,exploring the potential mechanisms of various diseases,studying the repair and regeneration of damaged tissues or organs,and promoting drug discovery and personalized treatment. OBJECTIVE:To review the research progress of pluripotent stem cells,summarize and categorize the fundamental types of pluripotent stem cells,and elucidate the lineage situations of various types of pluripotent stem cells in common mammals. METHODS:PubMed,Web of Science,CNKI,and WanFang databases were searched systematically,with the keywords"pluripotent stem cells;embryonic stem cells;induced pluripotent stem cells;expanded potential stem cells;livestock pluripotent stem cells"in English and Chinese.The 99 articles related to mammalian pluripotent stem cells were systematically screened according to inclusion and exclusion criteria,and then reviewed. RESULTS AND CONCLUSION:(1)According to classical theory in mouse embryonic stem cell research,the pluripotent state of stem cells is divided into two forms:na?ve and primed.Na?ve state corresponds to the inner cell mass of pre-implantation embryos before attachment to the uterine wall,while primed state corresponds to the epiblast after implantation.These two states exhibit significant differences in epigenetic features,transcriptional activity,external signal dependency,and metabolic phenotype.It is later discovered that there is an intermediate state between na?ve and primed called formative pluripotency.Therefore,the pluripotency of pluripotent stem cells is a continuous developmental process rather than a unique cell state.(2)In addition to obtaining pluripotent stem cells from the inner cell mass,there are various methods and lineages for acquiring pluripotent stem cells,including embryonic germ cells established using primitive germ cells from mouse embryos,induced pluripotent stem cells created by the dedifferentiation of adult mouse and human fibroblasts with four factors—Oct3/4,Sox2,c-Myc,and Klf4;embryonic stem cell-like cell lines cultured from somatic cell nuclear transfer,parthenogenesis,neonatal or adult testicular or ovarian tissue,very small embryonic-like stem cells derived from various adult tissues and expanded pluripotent stem cells derived from pre-implantation stages.These pluripotent stem cells all share the common characteristics of continuous self-renewal,expressing core pluripotency factors and possessing the ability to differentiate into the three primary germ layers.(3)Currently,pluripotent stem cells are being used for disease modeling to study the mechanisms of various diseases and develop new drugs.Simultaneously,scientists are attempting to use pluripotent stem cells to cultivate various tissues and organs,offering new possibilities for regenerative medicine and transplantation.However,the clinical application of pluripotent stem cells faces safety challenges,including issues of cell mutations and immune rejection.Continual improvement in the methods of generating pluripotent stem cells will make them safer and more efficient for clinical applications.(4)Based on the methods of obtaining and lineage establishment of pluripotent stem cells in mice and humans,various types of pluripotent stem cells have been established in livestock,including embryonic stem cells,induced pluripotent stem cells,germ lineages of pluripotent stem cells,and expanded potential stem cells.Research on livestock pluripotent stem cells opens up new avenues for animal reproduction,breeding,genetic engineering,disease modeling,drug screening,and the conservation of endangered wildlife.

Objective:To investigate the association between quantified CT (QCT)-measured body composition and metabolic syndrome (MS) components in obese populations before bariatric surgery.Methods:A cross-sectional study. A retrospective analysis was conducted on a cohort of 97 obese patients scheduled for weight-loss surgery at the First Affiliated Hospital of Wannan Medical College from January 2021 to March 2023. The patients′ body mass index (BMI), biochemical parameters and body composition measurements obtained by QCT were recorded. The patients were stratified into groups based on gender, obesity severity and the number of MS components. Differences in body composition among the groups were compared. Additionally, the correlations between each body composition parameter and metabolic indicators were analyzed. The diagnostic efficacy of each body composition parameter for identifying obese individuals with different MS components was assessed using receiver operating characteristic (ROC) curve analysis.Results:There were 75 females (77.3%). Male obese patients had higher total abdominal fat area [(693.23±148.90) vs (574.99±114.89) cm 2, t=-3.958, P<0.001], visceral fat area [(289.65±57.67) vs (195.60±57.37) cm 2, t=-6.753, P<0.001], fat content of pancreatic head [27.45%(21.65%, 45.48%) vs 21.60%(17.6%, 26.9%), Z=-2.675, P=0.007], and skeletal muscle index [73.36(68.74, 81.26) vs 61.52(55.74, 66.41) cm 2/m 2, Z=-5.246, P<0.001]. With the increase of obesity, abdominal fat mainly increases in subcutaneous fat. With the increase of MS components (MS2 group, MS3 group, MS4 group, MS5 group), the abdominal fat area, abdominal fat/subcutaneous fat, liver fat content, pancreatic head fat content, and skeletal muscle index of patients all increased accordingly. In diagnosing the presence of two components of MS, area under the curve of visceral fat area was the largest (AUC=0.706, 95% CI=0.577-0.834). For diagnosing the presence of three, four and five components of MS, area under curve of liver fat content were all the largest (MS3=0.712, 95% CI=0.605-0.818; MS4=0.652, 95% CI=0.537-0.766; MS5=0.706, 95% CI=0.576-0.836). Conclusion:There are differences in QCT body composition among obese patients with different MS components, and there is a correlation between each body composition and MS component. Among them, intra-abdominal fat area and liver fat content are of great value in evaluating obese patients with different MS components.

Objective To establish a novel clinical application process of the optical surface monitoring system(OSMS)guided volumetric modulated arc therapy(VMAT)for total body irradiation(TBI),and to assess the accuracy and effectiveness of OSMS in inter-fractional auxiliary positioning before radiotherapy and real-time monitoring of intra-fractional motion during radiotherapy.Methods A retrospective analysis was conducted on 15 leukemia patients who underwent OSMS-guided VMAT-TBI before hematopoietic stem cell transplantation.CT simulation positioning was performed,and the whole-body image data which were collected in head-first supine position(HFS)and feet-first supine position(FFS)were transmitted to the treatment planning system for image registration,multicenter VMAT planning and dose verification.The prescription dose was 800 cGy in 4 fractions twice daily.OSMS was used to assist positioning before delivery,and CBCT was used for position verification.During treatment,OSMS was used for monitoring.The intra-fractional error monitored by OSMS in real time was obtained by analyzing the offline log files.Results The mean dose and coverage of the target area in HFS plan were(905.4±19.0)cGy and 93.0%±2.8%.The mean doses to lung and kidney were(603.7±55.7)cGy and(600.4±49.6)cGy,respectively,and the maximum dose to the lens was(393.9±58.9)cGy.The mean dose and coverage of the target area in FFS plan were(888.5±58.9)cGy and 94.0%±3.2%;and the maximum dose at the junction was(1148.9±72.9)cGy.Fractional treatment delivery time was(75.1±15.1)min.OSMS-assisted positioning was carried out before delivery,and the total deviations of CBCT three-dimensional vector in translational and rotation directions were(2.71±1.96)mm and 0.91°±0.90°,respectively.The three-dimensional vector deviation of the intra-fractional motion amplitude in translational direction monitored by OSMS during the treatment was(1.95±1.88)mm,of which the deviation within 1 mm accounted for 57.5%,79.7%and 62.1%in longitudinal,lateral and vertical directions,respectively.The three-dimensional vector deviation in rotation direction was 0.76°±0.72°,of which the deviation within 1°accounted for 93.1%,85.7%and 94.3%in rotation,pitch and roll directions,respectively.Conclusion VMAT simplifies TBI process,while improving target coverage and organs-at-risk sparing.The use of OSMS can reduce positioning errors,especially rotation errors.In order to ensure the accurate implementation of TBI and the safety of patients,it is necessary to use OSMS for auxiliary positioning and intra-fractional position monitoring.

Objective:To compare translational and rotational setup errors between immobilization with open masks combined with positioning with the optical surface monitoring system (OSMS) and immobilization with full masks combined with positioning with laser lights and mask markers, find the advantages of open masks combined with OSMS in hypofractionated stereotactic radiotherapy (HSRT) for brain metastases, and calculate planning target volume (PTV) expansions with different immobilization and positioning method for patients with brain metastases.Methods:The setup data of 55 patients with brain metastases who received HSRT were analyzed retrospectively. According to immobilization and positioning method, the patients were divided into group A (OSMS + open masks), group B1 (full head-neck-shoulders masks + polyurethane foam cushions), and group B2 (full head-neck-shoulders masks + standard headrests). Positioning was directed by automatic couch motion in OSMS in group A and by laser lights and mask markers in groups B1 and B2. Cone beam computed tomography (CBCT) scans were registered using the bone registration method to obtain setup errors in six directions ( x, y, z, roll, pitch, yaw). PTV expansions were calculated according to the van Herk formula. Results:A total of 288 sets of CBCT registration data were acquired. Among three groups, group A showed the smallest mean setup errors and 3D vector error, which were (0.47±0.33) mm, (0.49±0.31) mm, (0.44±0.31) mm, (0.42±0.32)°, (0.48±0.31)°, (0.42±0.22)°, and (0.90±0.39) mm, respectively. Group A differed significantly from group B1 and group B2 in the errors at all directions ( P < 0.05) except for the yaw direction compared with group B1 ( P > 0.05). Group A had no setup error ≥2 mm in translational directions or ≥2° in rotational directions. Group B1 showed significantly smaller setup errors in the y, z, and yaw directions and 3D vector error than group B2 ( P < 0.05). In group A, PTV expansions in three directions ( x, y, and z) were 1.32, 1.19, and 1.22 mm, respectively, which were smaller than those of the other two groups. Conclusions:In HSRT for patient with brain metastases, compared with full head-neck-shoulders masks combined with laser lights and mask markers, open masks combined with OSMS can significantly improve setup precision in six directions and reduce repeated setup and PTV expansions, which shows promise for clinical application.

Objective:To evaluate the short-term effect of robotic pancreaticoduodenectomy (RPD) and laparoscopic pancreaticoduodenectomy (LPD) in the treatment of ampullary and periampullary tumor systematically.Methods:A systematic search of the PubMed, Embase and Cochrane library database using the key words "pancreaticoduodenectomy, duodenopanreatectpmy, whipple, laparoscopic, robotic, Da Vinci" . A systematic search of the Sinomed, Wangfang, VIP and CNKI databases including the key words "胰十二指肠切除" , "腹腔镜" , "机器人" , "达芬奇" . To investigate the differences of the conversion rate of laparotomy, incidence of postoperative complications, and the postoperative hospital stay between the RPD group and the LPD group. The software RevMan5.3 was used in this meta-analysis.Results:A total of 4 retrospective cohort studies and 1 001 patients were included in this meta-analysis, including 451 patients in the RPD group and 550 patients in the LPD group. The results of the meta-analysis showed that there were significant differences between RPD group and LPD group for the conversion rate laparotomy ( OR=0.35, 95% CI: 0.24-0.50, P<0.05). There were no significant differences between RPD group and LPD group for the incidence rate of overall complication( OR=1.23, 95% CI: 0.95-1.58, P>0.05), hemorrhage ( OR=0.71, 95% CI: 0.50-1.00, P>0.05), pancreatic fistula ( OR=1.09, 95% CI: 0.80-1.49, P>0.05), delayed gastric empty ( OR=0.81, 95%CI: 0.57-1.14, P>0.05) and hospital stay after surgery ( WMD=-2.87, 95% CI: -1.44-1.70, P>0.05). Conclusions:RPD is as safe as LPD, with the same complication rate. Therefor it is worthy for further application in medical institutions with relevant conditions.

Objective:To compare the dosimetric differences between volumetric-modulated arc therapy (VMAT) and intensity-modulated radiation therapy (IMRT) on planning target volume (PTV) and organ-at-risk (OAR) for breast cancer after modified radical mastectomy, aiming to provide evidence-based reference for clinical practice.Methods:According to strict inclusion and exclusion criteria, literature search was performed in PubMed, Cochrane Library, FMRS, CNKI, Wanfang Data and VIP full text databases from the inception of databases up to March 2020. The controlled clinical trials of dosimetric comparison between VMAT and IMRT for breast cancer following modified radical mastectomy were selected. The meta-analysis was performed using Stata14 software.Results:The meta-analysis included 281 patients from 13 observational studies. Compared with IMRT, VMAT significantly increased the PTV dose coverage D 95%( P<0.001) and significantly improved the PTV homogeneity index (HI, P<0.001) and conformity index (CI, P=0.004). Compared with IMRT, VMAT more effectively decreased the ipsilateral lung V 20Gy (WMD=1.332, P=0.027) and contralateral lung V 10Gy ( P=0.003). There were no significant differences in theD mean, V 5Gy, V 10Gy and V 30Gy of the ipsilateral lung, D mean and V 5Gy of the contralateral lung, D mean, V 10Gy and V 30Gy of the heart between VMAT and IMRT (all P>0.05). Compared with VMAT, IMRT reduced the cardiac V 5Gy ( P=0.001). However, sensitivity analysis of included literature on cardiac V 5Gy showed that the P value was reversed, indicating that the stability of the results was poor. VMAT significantly shortened the delivery time ( P<0.001) and the number of monitor units ( P<0.001) compared to IMRT. Conclusion:Compared with IMRT, VMAT can achieves superior target dose coverage, HI and CI, better protection for the ipsilateral and contralateral lung, fewer monitor units and shorter delivery time.

Objective To evaluate laparoscopic surgery for Mirizzi syndrome.Methods A retrospective study was carried out on 14 patients undergoing laparoscopic operation for Mirizzi syndrome from Feb.2013 to Nov.2018.There were 4 patients of type Ⅰ,8 patients of type Ⅱ,2 patients of type Ⅲ according to Csendes classification.Results Laparoscopic procedures were successfully completed in all patients.All 4 cases of type Ⅰ received laparoscopic cholecystectomy.4 patients of type Ⅱ were given laparoscopic cholecystectomy combined with primary suture of common bile duct;the other 4 patients of type Ⅱ underwent laparoscopic cholecystectomy plus T tube drainage.2 patients of type Ⅲ were treated with laparoscopic partial-cholecystectomy combined with repair of the duct defect and T tube drainage.All the patients recovered uneventfully.The postoperative hospitalization time was 4 to 7 d,with an average of 5.5 d.There were no major postoperative complications.14 patients were followed up for 1-8 months,and there was no biliary stricture and no stone recurrences.Conclusion For cases of type Ⅰ,type Ⅱ and type Ⅲ,laparoscopic surgery is a safe treatment.

Objective To design a portable electroencephalography(EEG) acquisition system to acquire and analysis steady-state visual potentials (SSVEP). Methods The microprocessor MSP432P401 series MCU was used to control the high-performance integrated analog front end ADS1299 to realize the acquisition, amplification and analog-to-digital (AD) conversion of EEG signals. The digital EEG signal is sent to the host computer for processing by WIFI. Spontaneous EEG signals and steady-state visually evoked EEG signals from 3 healthy subjects were collected to verify system performance. Results The collected signal had a clear α-wave rhythm of closed-eye spontaneous EEG signals. The power spectrum density shows that the steady-state visually induced EEG signal frequency and harmonic frequency peak at the corresponding stimulation frequency, indicating that the system works normally and the performance is good. Conclusions The designed portable EEG acquisition system can accurately collect the spontaneous and induced EEG signals of the human body, which provides technical support for the clinical application of SSVEP technology.

Objective To determine the difference of macular ganglion cell-inner plexiform layer (mGCIPL) thickness and peripapillary retinal nerve fiber layer (pRNFL) thickness using Cirrus HD-OCT between older and young people in order to provide information for glaucomatous progressive analysis.Methods A prospective case series study was adopted.Sixty-seven old persons (114 eyes) aged 60-80 years old were selected from retired staff of an institution who underwent routine physical examinations between June and July 2016 in Beijing Tongren Hospital as older group and 24 young persons(42 eyes) aged (20-40 years old) who underwent routine physical examination at the same period were selected as young group.The total superior,superonasal,inperonasal,inferior,inferotemporal and superotemporal mGCIPL thickness and PRNFL thickness were measured by Cirrus HD-OCT.The research followed the Declaration of Helsinki.The ethics committee of the Tongren Eye Center approved the study and all participants provided an informed consent.Results There were statistical differences in all measurement parameters (mGCIPL and pRNFL) between older and young people (all at P＜0.05) except nasal pRNFL thickness.Minimum mGCIPL thickness was significantly different between older and young group [(74.02±11.01) pm vs.(82.74 ±3.94) μm;t =-7.290,P＜0.001],while in the pRNFL parameters,temporal pRNFL thickness was siginicantly changed between older and young group [(70.83 ± 12.30) μm vs.(82.10 ± 17.02) μm;t =-3.930,P ＜ 0.001].The nasal pRNFL thickness showed no significant difference between the two groups.Conclusions All mGCIPL and most pRNFL parameters in older people were obviously thinner than young people except nasal pRNFL,age factor should be considered seriously in the progression analysis of glaucomatous neuropathy.

Objective This study was to evaluate the long-term clinical efficiency of allogeneic corneal intrastromal lenticule inlay for correction of moderate and high hyperopia.Methods A prospective self-controlled case series study was adopted.Twenty-nine hyperopic patients (53 eyes) were performed with allogeneic corneal intrastromal lenticule inlays.The range of preoperative spherical equivalent was +3.75 to + 10 D,with the mean value of (+6.84±2.95)D.All the cases were followed up for 1 year.Uncorrected and best corrected visual acuity and refraction were compared between before and after operation.Corneal topography and optical coherence topography were used to examine corneal topography.Ocular response analyzer was used to evaluate the shifts of corneal hysteresis.This study followed the Helsinki declaration,and the research process was approved by the Ethic Committee of Beijing Tongren Hospital,and informed consent was signed by each donor and receptor.Results Compared with the before surgery,the uncorrected distance visual acuity (UDVA) and uncorrected near visual acuity (UNVA) were obviously improved and the spherical equivalent (SE) was obviously decresed in 3 months,6 months and 1 year after surgery,with significant differences between them (all at P＜0.05),but no significant differences were found between each postoperative time points (all at P＞0.05).One year after surgery,14 eyes (26.4％) gained one line of best corrected distance visual acuity (BCDVA),and 12 eyes (22.6％) gained two lines of BCDVA.Only 2 patients (5.66％) lost lines due to opaque lenticules,and no eye lost lines after changing the opaque lenticules.There was no obvious hyperopic fallback phenomenon.Compared with the before surgery,the average corneal curvature value (Avek) was obviously improved,the surface regularity index (SRI),surface asymmetry index (SAI) and central corneal thickness (CCT) were obviously increased in 3 months,6 months and 1 year after surgery,with significant differences between them (all at P＜0.05),but no significant differences were found between each postoperative time points (all at P ＞ 0.05).The cornea optical coherence tomography (OCT) examination showed that,after the operation,the corneal stromal implant was in place and clear.One year after surgery,the dividing line of corneal graft was still clearly visible.No significant changes of corneal hysteresis (CH) and corneal resistance factor (CRF) were seen among different time points before and after surgeries (F =1.443,P =0.216;F =1.744,P =0.128).Conclusions Allogeneic corneal small incision intrastromal lenticule inlays can be used to correct moderate and high hyperopic eye with good safety,effectiveness and predictability.It provides a new choice for hyperopic patients.