LncRNA DRAIC regulates the proliferation, apoptosis, migration and invasion of lung adenocarcinoma cells by targeting let-7i-5p / 中华肿瘤杂志

Objective: To investigate the effects of lncRNA DRAIC on proliferation, apoptosis, migration and invasion of lung adenocarcinoma cells and its mechanism. Methods: Reverse transcription-quantitative real-time polymerase chain reaction (RT-qPCR) was used to detect the expression of DRAIC in lung cancer tissues and corresponding adjacent normal tissues of 40 patients with lung adenocarcinoma who underwent surgery in Tangshan People's Hospital from 2019 to 2020. Lung adenocarcinoma cells A549 and H1299 were cultured in vitro and divided into si-NC group, si-DRAIC group, miR-NC group, let-7i-5p mimics group, si-DRAIC+ inhibitor-NC group, and si-DRAIC+ let-7i-5p inhibitor group. CCK-8 method and clone formation experiment were used to detect cell proliferation. Flow cytometry was used to detect cell apoptosis. Transwell array was used to detect the cell migration and invasion. Western blot was used to detect the protein expressions of Caspase-3, Caspase-9, Bcl-2 and Bax. The double luciferase reporter gene experiment was used to verify the regulatory relationship between DRAIC and let-7i-5p. Independent sample t test was used for comparison between two groups, one-way ANOVA was used for comparison between multiple groups, and Pearson correlation analysis was used for correlation analysis. Results: Compared with adjacent tissues, the expression level of DRAIC in lung adenocarcinoma tissues increased (P<0.05), but the expression level of let-7i-5p decreased (P<0.05). The expression levels of DRAIC and let-7i-5p in lung adenocarcinoma tissues were negatively correlated (r=-0.737, P<0.05). The absorbance value of A549 and H1299 cells in the si-DRAIC group at 48, 72 and 96 hours were lower than those in the si-NC group (P<0.05), the number of clones formed [(91.00±6.08 vs. 136.67±6.51); (50.67±1.53 vs. 76.67±4.51)], the number of migration [(606.67±31.34 vs. 960.00±33.06); (483.33±45.96 vs. 741.67±29.67)], the number of invasion [(185.00±8.19 vs. 447.33±22.05); (365.00±33.87 vs. 688.00±32.97)] were lower than those in the si-NC group (P<0.05). However, the apoptosis rates of cells [(13.43±2.79)% vs. (4.53±0.42)%; (23.77±1.04)% vs. (6.60±1.42)%] were higher than those in the si-NC group (P<0.05). The protein expressions of Caspase-3, Caspase-9 and Bax in si-DRAIC group were higher than those in si-NC group, and the protein expression of Bcl-2 was lower than that in si-NC group (P<0.05). DRAIC is located in the cytoplasm. DRAIC targeted and negatively regulated the expression of let-7i-5p. The absorbance values of A549 and H1299 cells in the let-7i-5p mimics group at 48, 72 and 96 hours were lower than those in the miR-NC group (P<0.05), the number of clones formed [(131.33±14.47 vs. 171.33±6.11); (59.33±4.93 vs. 80.33±7.09)], the number of migration [(137.67±3.06 vs. 579.33±82.03); (425.00±11.14 vs. 669.33±21.13)], the number of invasion [(54.00±4.36 vs. 112.67±11.59); (80.00±4.58 vs. 333.33±16.80)] were lower than those in the miR-NC group (P<0.05). However, the apoptosis rates of cells [(14.57±1.10)% vs. (6.97±1.11)%; (23.97±0.42)% vs. (7.07±1.21)%] were higher than those in the miR-NC group (P<0.05). The protein expressions of Caspase-3, Caspase-9 and Bax in let-7i-5p mimics group were higher than those in miR-NC group, and the protein expression of Bcl-2 was lower than that in miR-NC group (P<0.05). The absorbance values of A549 and H1299 cells in the si-DRAIC+ let-7i-5p inhibitor group at 48, 72 and 96 hours were higher than those in the si-DRAIC+ inhibitor-NC group (P<0.05), the number of clones formed [(82.00±5.29 vs. 59.00±5.57); (77.67±4.93 vs. 41.33±7.57)], the number of migration [(774.33±35.81 vs. 455.67±19.04); (569.67±18.72 vs. 433.67±16.77)], the number of invasion [(670.33±17.21 vs. 451.00±17.52); (263.67±3.06 vs. 182.33±11.93)] were higher than those in the si-DRAIC+ inhibitor-NC group (P<0.05). However, the apoptosis rates of cells [(7.73±0.45)% vs. (19.13±1.50)%; (8.00±0.53)% vs. (28.40±0.53)%] were lower than those in the si-NC group (P<0.05). The protein expressions of Caspase-3, Caspase-9 and Bax in si-DRAIC+ let-7i-5p inhibitor group were higher than those in si-DRAIC+ inhibitor-NC group, and the protein expression of Bcl-2 was lower than that in si-DRAIC+ inhibitor-NC group (P<0.05). Conclusion: DRAIC is highly expressed in lung adenocarcinoma, and DRAIC promotes the proliferation, migration and invasion of lung adenocarcinoma cells and inhibits apoptosis by targeting let-7i-5p.

The exploration and practice on postgraduate education model of professional degree in clinical medicine based on the background of medical education collaboration / 中华医学教育探索杂志

Based on the background of medical education collaboration, postgraduate education of professional degree in clinical medicine needs to be combined with social needs to reform and to carry on the exploration of high-level talents cultivation mode of clinical medicine. The article states the exploration and practice to establish the cultivation mode of clinical medicine as an organic integration of multi-module curriculum system, multi-level clinical practice and multi-directional scientific research training. Then it gives some thoughts and suggestions based on the practice, including potent teaching function of clinical medical college, reasonable clinical teaching incentive mechanism and favorable conditions for clinical research, in order to provide theoretical basis and practice experiences of high-level talents cultivation mode of clinical medicine.

SIRT1 activation synergizes with FXR agonism in hepatoprotection via governing nucleocytoplasmic shuttling and degradation of FXR

Farnesoid X receptor (FXR) is widely accepted as a promising target for various liver diseases; however, panels of ligands in drug development show limited clinical benefits, without a clear mechanism. Here, we reveal that acetylation initiates and orchestrates FXR nucleocytoplasmic shuttling and then enhances degradation by the cytosolic E3 ligase CHIP under conditions of liver injury, which represents the major culprit that limits the clinical benefits of FXR agonists against liver diseases. Upon inflammatory and apoptotic stimulation, enhanced FXR acetylation at K217, closed to the nuclear location signal, blocks its recognition by importin KPNA3, thereby preventing its nuclear import. Concomitantly, reduced phosphorylation at T442 within the nuclear export signals promotes its recognition by exportin CRM1, and thereby facilitating FXR export to the cytosol. Acetylation governs nucleocytoplasmic shuttling of FXR, resulting in enhanced cytosolic retention of FXR that is amenable to degradation by CHIP. SIRT1 activators reduce FXR acetylation and prevent its cytosolic degradation. More importantly, SIRT1 activators synergize with FXR agonists in combating acute and chronic liver injuries. In conclusion, these findings innovate a promising strategy to develop therapeutics against liver diseases by combining SIRT1 activators and FXR agonists.

Dihydromyricetin mediates epithelial mesenchymal transformation and regulates the proliferation and apoptosis of esophageal squamous cell carcinoma cells / 中华肿瘤杂志

Objective: To study the effects of dihydromyricetin (DMY) on the proliferation, apoptosis and epithelial mesenchymal transition (EMT) of esophageal squamous cell carcinoma (ESCC) cell KYSE150 and KYSE410. Methods: KYSE150 and KYSE410 cells were treated with different concentrations of DMY (0, 25, 50, 100, 150, 200 μmol/L) for 24 hours. The median inhibition concentration (IC50) values of KYSE150 and KYSE410 were detected by cell counting kit-8 (CCK-8) method. Then 0.5‰ dimethyl sulfoxide (DMSO) was used as control group, dihydromyricetin (DMY), dihydromyricetin and transforming growth factor-β1 (DMY+ TGF-β1), transforming growth factor-β1 (TGF-β1) were used as experimental group. Cell proliferation and apoptosis rates were measured by clonal formation and flow cytometry. Transwell invasion and wound healing assay were used to detect cell invasion and migration. The protein expression levels of Caspase-3, Caspase-9, Bcl-2, Bax, Smad2/3, phosphorylation-Smad2/3 (p-Smad2/3) and Vimentin were detected by western blot. Results: The IC50 values of DMY on KYSE410 and KYSE150 cells were 100.51 and 101.27 μmol/L. The clone formation numbers of KYSE150 and KYSE410 in DMY group [(0.53±0.03) and (0.31±0.03)] were lower than those in DMSO group [(1.00±0.10) and (1.00±0.05), P<0.05]. The apoptosis rates of KYSE150 and KYSE410 cells in DMY group [(1.84±0.22)% and (2.80±0.07)%] were higher than those in DMSO group [(1.00±0.18)% and (1.00±0.07)%, P<0.05]. The invasion numbers of KYSE150 and KYSE410 cells in DMY group [(0.42±0.03) and (0.29±0.05)] were lower than those in DMSO group [(1.00±0.08) and (1.00±0.05), P<0.05]. The migration rates of KYSE150 and KYSE410 cells in DMY group [(0.65±0.14)% and (0.40±0.17)%] were lower than those in DMSO group [(1.00±0.10)% and (1.00±0.08)%, P<0.05]. The clone formation numbers of KYSE150 and KYSE410 in TGF-β1 group [(1.01±0.08) and (0.99±0.25)] were higher than those in DMY+ TGF-β1 group [(0.73±0.10) and (0.58±0.05), P<0.05]. The apoptosis rates of KYSE150 and KYSE410 cells in TGF-β1 group [(0.81±0.14)% and (1.18±0.10)%] were lower than those in DMY+ TGF-β1 group [(1.38±0.22)% and (1.85±0.04)%, P<0.05]. The invasion numbers of KYSE150 and KYSE410 cells in TGF-β1 group [(1.19±0.11) and (1.39±0.11)] were higher than those in DMY+ TGF-β1 group [(0.93±0.09) and (0.93±0.05), P<0.05]. The migration rates of KYSE150 and KYSE410 cells in TGF-β1 group [(1.87±0.19)% and (1.32±0.04)%] were higher than those in DMY+ TGF-β1 group [(0.86±0.16)% and (0.77±0.12)%, P<0.05]. The protein expression levels of Bax, Caspase-3 and Caspase-9 in KYSE150 and KYSE410 cells in DMY group were higher than those in DMSO group, while the protein expression level of Bcl-2 was lower than that in DMSO group (P<0.05). The protein expression levels of p-Smad2/3, Smad2/3 and Vimentin in KYSE150 and KYSE410 cells in DMY group were lower than those in DMSO group (P<0.05). The protein expression levels of Bax, Caspase-3 and Caspase-9 in KYSE150 and KYSE410 cells in TGF-β1 group were lower than those in DMY+ TGF-β1 group, and the protein expression level of Bcl-2 was higher than that in DMY+ TGF-β1 group (P<0.05). The protein expression levels of Bax, Caspase-3 and Caspase-9 in KYSE150 and KYSE410 cells in DMY+ TGF-β1 group were lower than those in DMY group, and the protein expression level of Bcl-2 was higher than that in DMY group (P<0.05). The protein expression levels of p-Smad2/3, Smad2/3 and Vimentin in KYSE150 and KYSE410 cells in TGF-β1 group were higher than those in DMY+ TGF-β1 group (P<0.05). Conclusion: DMY can inhibit the proliferation and EMT of ESCC mediated by TGF-β1 and promote cell apoptosis.

Application of modified Delphi method in the construction of curriculum of emergency professional postgraduates / 中华医学教育探索杂志

Objective:At present, the postgraduate education of emergency medicine in China mainly relies on the internal medicine system and lacks specialty pertinence. The purpose of this study is to establish a compulsory curriculum system for professional postgraduates of emergency medicine.Methods:Modified Delphi method was used to subscribe questionnaires to experts, and the contents were mainly about medical education management and research of emergency in the affiliated teaching hospitals of Peking University. Microsoft Excel 2016 was used for double entry of questionnaire contents, and SPSS 22.0 software was used for statistics.Results:The panel was consisted of 14 experts in total and two rounds of Delphi questionnaires were completed. The response rate of the two rounds were both 100%. The authority coefficient of experts was > 0.9 and the average score of each evaluation index was 4.07-5.00 points. The coefficient of variation of each index was 0-0.22 and the Kendall coefficient of concordance was 0.07-0.10.Conclusion:As a result, a comprehensive emergency professional postgraduate curriculum system has been established.

Silybin alleviates hepatic lipid accumulation in methionine-choline deficient diet-induced nonalcoholic fatty liver disease in mice via peroxisome proliferator-activated receptor α / 中国天然药物

Nonalcoholic fatty liver disease (NAFLD) is regarded as the most common liver disease with no approved therapeutic drug currently. Silymarin, an extract from the seeds of Silybum marianum, has been used for centuries for the treatment of various liver diseases. Although the hepatoprotective effect of silybin against NAFLD is widely accepted, the underlying mechanism and therapeutic target remain unclear. In this study, NAFLD mice caused by methionine-choline deficient (MCD) diet were orally administrated with silybin to explore the possible mechanism and target. To clarify the contribution of peroxisome proliferator-activated receptor α (PPARα), PPARα antagonist GW6471 was co-administrated with silybin to NAFLD mice. Since silybin was proven as a PPARα partial agonist, the combined effect of silybin with PPARα agonist, fenofibrate, was then evaluated in NAFLD mice. Serum and liver samples were collected to analyze the pharmacological efficacy and expression of PPARα and its targets. As expected, silybin significantly protected mice from MCD-induced NAFLD. Furthermore, silybin reduced lipid accumulation via activating PPARα, inducing the expression of liver cytosolic fatty acid-binding protein, carnitine palmitoyltransferase (Cpt)-1a, Cpt-2, medium chain acyl-CoA dehydrogenase and stearoyl-CoA desaturase-1, and suppressing fatty acid synthase and acetyl-CoA carboxylase α. GW6471 abolished the effect of silybin on PPARα signal and hepatoprotective effect against NAFLD. Moreover, as a partial agonist for PPARα, silybin impaired the powerful lipid-lowering effect of fenofibrate when used together. Taken together, silybin protected mice against NAFLD via activating PPARα to diminish lipid accumulation and it is not suggested to simultaneously take silybin and classical PPARα agonists for NAFLD therapy.

Combined obeticholic acid and apoptosis inhibitor treatment alleviates liver fibrosis

Obeticholic acid (OCA), the first FXR-targeting drug, has been claimed effective in the therapy of liver fibrosis. However, recent clinical trials indicated that OCA might not be effective against liver fibrosis, possibly due to the lower dosage to reduce the incidence of the side-effect of pruritus. Here we propose a combinatory therapeutic strategy of OCA and apoptosis inhibitor for combating against liver fibrosis. CCl-injured mice, d-galactosamine/LPS (GalN/LPS)-treated mice and cycloheximide/TNF (CHX/TNF)-treated HepG2 cells were employed to assess the effects of OCA, or together with IDN-6556, an apoptosis inhibitor. OCA treatment significantly inhibited hepatic stellate cell (HSC) activation/proliferation and prevented fibrosis. Elevated bile acid (BA) levels and hepatocyte apoptosis triggered the activation and proliferation of HSCs. OCA treatment reduced BA levels but could not inhibit hepatocellular apoptosis. An enhanced anti-fibrotic effect was observed when OCA was co-administrated with IDN-6556. Our study demonstrated that OCA inhibits HSCs activation/proliferation partially by regulating BA homeostasis and thereby inhibiting activation of HSCs. The findings in this study suggest that combined use of apoptosis inhibitor and OCA at lower dosage represents a novel therapeutic strategy for liver fibrosis.

Study on the effect of training base on promoting postgraduates in professional degree of clinical medicine / 中华医学教育探索杂志

Clinical training base is playing an important role in the quality guarantee of postgradu-ates in clinical medicine. The clinical allocation, teaching resources and teaching staff are important factors affecting the quality of teaching. Clinical training bases should define the teaching objectives and guarantee the teaching orientation, organization and incentive system. Meanwhile, the clinical training bases should do well in teaching evaluation and continuous improvement, so that to promote the implementation of teaching objectives and ensure the quality of teaching. Finally, a training mechanism centering on the growth and development of postgraduates majoring in clinical medicine will be constructed, improving the training effect and cultivating excellent clinicians.

Survey on value factors influencing the quality of medical Joint-PhD education: from the angle of Baldrige Performance Excellence program / 中华医学教育探索杂志

Objective Joint-PhD program is an effective way to cultivate international creative talents.Survey on intrinsic value factors of this mode is significant to improve the quality of medical education.Methods According to the questionnaire results and reports of 104 medical doctorates who attended the Joint-PhD program in PUHSC,Baldrige Performance Excellence was taken as theoretical framework.Results It showed that index influencing the quality of Joint-PhD education include social responsibility;stakeholders' expectation and market requirements;information and knowledge management support and so on.Conclusion In the process of doctoral education,advocating value of social responsibility,paying attention to the expectations of stakeholders,and attaching importance to the validity of education management services help to understand the intrinsic value of the quality management from the top universities in the world,in order to fundamentally improve the quality of doctoral education.

The investigation on the current status of research training of M.D and S.M.D / 中华医学科研管理杂志

This study conducted questionnaire survey to graduate medical students in Medicine (M.D.) and Stomatological Medicine (S.M.D) enrolled at Peking University Health Science Center in the year 2013,analyzed on the understanding,period,forms,mentoring and effect of research training.Suggestions are proposed to strengthen the research training,for example,focusing on clinical training as well as research training,aiming at clinical issues,emphasize of clinical scientific research,permeating the concept oftransformation medicine,promotion of intense full-time research,strengthen the mentoring of professors.

Investigation on the current state of training system for master of clinical medicine (general practice) / 中华医学教育探索杂志

Objective To gain a better knowledge of the education for masters in clinical medicine (general practice) and provide a reference for the better exploration of the training mode of GP students.Methods 9 colleges and universities enrolling students for this program were selected with stratified sampling.A questionnaire was conducted in terms of admission,curriculum setting,clinical training,guidance and evaluation through officials in charge of graduate affairs from February to July in 2014.Descriptive analysis was performed to the investigation results,using SPSS 20.0 statistical software.Results A full-time undergraduate degree in clinical medicine was explicitly required in 88.9％ (8/9) of colleges and universities.The average total credits of the course were 23.7 and the average clinical training duration was 32.4 months.Tutor group was adopted in all colleges and universities.The assessment and evaluation of the GP masters was mainly composed of multiple forms of process assessment and final evaluation.Conclusion We suggest attaching more importance to the improvements of enrollment policy,curriculum system,clinical training,standardized training base construction,teaching staff,and evaluation system in order to explore GP training mode in accord with the law of general practice and suitable for China's national conditions.

Research on the current status of education funds investment and living treatment of professional master's degree of clinical medicine / 中华医学教育探索杂志

Objective To gain a better knowledge of the changes of education funds investment for postgraduates of professional master's degree of clinical medicine before and after reform of the investment mechanism of graduate education. Methods 16 universities in which pilot reform of connection between postgraduate education and standardized training for residents were established were selected. A survey was conducted in terms of education funds investment, cost and living treatment during the period of clinical training. It also included the situation of standardized medical residency training. Descriptive analysis and t-test were performed to investigation results, using SPSS 20.0 statistical software. Results The average education funds were (17 100 ±11 100) yuan per person and (20 700 ±11 800) yuan per person, living treatments were (11 600±8 700) yuan per person per year and (10 200±8 700) yuan per person per year, tuition fees were (7 700±3 600) yuan per person per year and (8 800±2 100) yuan per person per year, tuition fees paid by students were (3 600±3 900) yuan per person per year and (7 700±3 400) yuan per person per year respectively before and after reform. Differences of average education funds, living treat-ments and tuition fees were not significant, while the difference between tuition fees paid by students were significant. After the re-form, students pay more tuition fees than before. Funds investment and living treat-ment of residents were significantly higher than that of graduate students. Conclusion Differences of edu-cation funds investment for professional master's degree of clinical medicine are great. And the training funds are difficult to fully meet the requirements of the culture. The life treatment is difficult to achieve equal pay to residents. We suggest perfecting the medical colleges financing mechanism and management, unifying and improving all kinds of medical college student funding standards, and setting up special funds to improve the postgraduate life treatment.

The construction and practice of training system for full-time masters of public health / 中华医学教育探索杂志

From the related work of comprehensive reform pilot for full-time Master of Public Health (MPH) professional degree education, we introduced Peking University and Fudan University's specific measures and achievements of cultivation of MPH position, admissions, curriculum, faculty, teaching, research, dissertations and etc. While comparing China's modes with John Hopkins University's and Harvard University's, we gave advice and made suggestions for our future full-time master of public health graduate training in China.

The study of internal evaluation index system in the field of medical academic postgraduate education / 中华医学教育探索杂志

From the perspective of institute of medical higher education, a set of index system which include three first level indicators has been constructed, for medical academic postgraduate ed-ucation internal evaluation with the method of expert advice as well as in-depth interview, and then through Delphi consulting, the weight of every indicator has been calculated. The weight of three first level indicators are 0.28 (educational condition), 0.42 (educational process), 0.30 (educational results) respectively. Finally, how to carry out internal evaluation and how to apply the results effec-tively have been discussed.

Urinary soluble intercellular adhesion molecule-1 and vascular cellular adhesion molecule-1: potential biomarkers of active lupus nephritis / 南方医科大学学报

<p><b>OBJECTIVE</b>To determine the levels of urinary soluble intercellular adhesion molecule-1 (sICAM-1) and vascular cellular adhesion molecule-1 (VCAM-1) in patients with lupus nephritis (LN), and explore their correlation with renal disease activity.</p><p><b>METHODS</b>Urine samples were collected from 92 renal biopsy-proven LN patients and 20 healthy controls. Renal disease activity was determined according to the ISN/RPS 2003 Revised Classification of Lupus Nephritis. The urine levels of sICAM-1 and VCAM-1 were detected by enzyme-linked immunosorbent assay, and the expressions of intrarenal ICAM-1 and VCAM-1 were evaluated by immunohistochemisty staining.</p><p><b>RESULTS</b>Urinary sICAM-1 and VCAM-1 levels were elevated in LN patients compared with the controls. Significantly higher levels of urinary sICAM-1 and VCAM-1 were found in patients with active LN, who had also significantly increased intrarenal expressions of ICAM-1 and VCAM-1 compared with patients in remission. A strong positive correlation was noted between intrarenal expression and urine levels of ICAM-1 and VCAM-1. The receiver-operating characteristic (ROC) curve of urine sICAM-1 showed tan area under ROC curve of 0.874 for all participants in the test. A cutoff of 1095.00 pg/mg creatinine yielded a good sensitivity (0.945) and specificity (0.789). The ROC curve of urine VCAM-1 showed an area under ROC of 0.882 for all the participants, and a cutoff of 898.11 pg/mg creatinine yielded a good sensitivity (0.982) and specificity (0.667).</p><p><b>CONCLUSION</b>Urine sICAM-1 and VCAM-1 levels are positively correlated with their intrarenal expressions and reflect the activity of the nephritis, and therefore they may serve as potential biomarkers for early diagnosis of active LN.</p>

Production of mature red blood cell by using peripheral blood mononuclear cells / 中国实验血液学杂志

Most protocols for in vitro producing red blood cells (RBC) use the CD34(+) cells or embryonic stem cells from cord blood, bone marrow or peripheral blood as the start materials. This study was purposed to produce the mature RBC in vitro by using peripheral blood mononuclear cells as start material. The peripheral blood mononuclear cells (PBMNC) were isolated from buffy coat after blood leukapheresis, the mature red blood cells (RBC) were prepared by a 4-step culture protocol. The results showed that after culture by inducing with the different sets of cytokines and supporting by mouse MS-5 cell line, the expansion of PBMNC reached about 1000 folds at the end of the culture. About 90% of cultured RBC were enucleated mature cells which had the comparable morphological characteristics with normal RBC. Colony-forming assays showed that this culture system could stimulate the proliferation of progenitors in PBMNC and differentiate into erythroid cells. The structure and function analysis indicated that the mean cell volume of in vitro cultured RBC was 118 ± 4 fl, which was slight larger than that of normal RBC (80-100 fl); the mean cell hemoglobin was 36 ± 1.2 pg, which was slight higher than that of normal RBC (27-31 pg); the maximal deformation index was 0.46, which approachs level of normal RBC; the glucose-6-phosphate dehydrogenase and pyrurvate kinase levels was consistant with young RBC. It is concluded that PBMNC are feasble, convenient and low-cost source for producing cultured RBC and this culture system is suitable to generate the RBC from PBMNC.

Adipose-derived mesenchymal stem cell therapy for radiation-induced vascular injury in small intestine of rat / 中华放射医学与防护杂志

Objective To assess the therapeutic effect of human adipose-derived mesenchymal stem cells on radiation-induced vascular injury in the small intestine of rat. Methods A total of 34 male Sprague-Dawley rats were enrolled in this study. To establish a model of radiation-induced intestinal injury, each rat was irradiated with 15 Gy in whole abdomen. 17 rats were randomly selected and infused intraperitoneally with passage 6 ( P6 ) Ad-MSCs, and the other 17 rats that received PBS were set as control. 10 days post-irradiation, the number of CD31+ endothelial cells in the small intestine villus was measured by flow-cytometry, the expressions of CD31, CD105 and isolectin-B4 in the na?ve endothelial cells with detected by IHC-staining, and the vascular integrity was evaluated by measuring VE-Cadherin. The origination of na?ve endothelial cells within injured intestine was also analyzed. In addition, total mRNA were extracted from irradiated small intestine to assay the expressions of VEGF, bFGF, Flk-1 and SDF-1 using quantitative Real-time PCR. Results Compared to the control, the amount of CD31-postive endothelial cells within irradiated intestine was significantly increased after Ad-MSCs infusion ( t=12?15, P<0?05). The microvascular density in the injured sites was also significantly increased by the infusion of Ad-MSCs (20 d:t=10?33, P<0. 05;30 d:t=32?85, P<0?05). Moreover, the expressions of VEGF, bFGF, Flk-1 and SDF-1 were significantly up-regulated after delivery of Ad-MSCs ( VEGF:t =10?34, bFGF:t=11?25,Flk-1:t=6?73, SDF-1:t=6?73, all P<0?05), which was beneficial in maintaining the integrity of intra-villus blood-vessels as well as promoting neovascularization in the injured sites. Conclusion Ad-MSCs had potentials in healing radiation-induced vascular injury in rat small intestine.

Therapeutic effect of adipose-derived mesenchymal stem cells on radiation enteritis / 中华放射医学与防护杂志

Objective To evaluate the therapeutic effect of adipose-derived mesenchymal stem cells on radiation enteritis.Methods A total of 52 male Sprague-Dawley rats were used in the present study.Herein,46 rats were randomly selected and irradiated with a dose of 15 Gy at their abdomens.Two hours post-irradiation,23 rats were randomly selected and infused intraperitoneally with adipose-derived mesenchymal stem cells in passage 6 from young-female donor.The other 23 rats were intraperitoneally infused with PBS.The rest 6 rats were set as normal control.During the first 10 days post-irradiation,peripheral blood-samples from irradiated rats were harvested for testing the levels of IL-10 in serum using ELISA assay.Additionally,after isolating the thymic cells and peripheral blood mononuclear cells,the percentages of CD4/CD25/Foxp(3)-positive regulatory T cells in thymus and peripheral blood were tested by flow-cytometry.Finally,infiltration of inflammatory cells and deposition of collagens within irradiated small intestine were analyzed by H&E staining and Masson Trichrome staining,respectively.Based on the MPO-immunohistochemistry staining,the type of infiltrated cells was identified.The Kaplan-Meier method was used for analyzing the survival rate of irradiated rats.Results During a period of 30 days post-irradiation,the irradiated rats receiving adipose-derived mesenchymal stem cells survived longer than those receiving PBS (t =4.53,P ＜ 0.05).Compared to the irradiated rats with PBS-treatment,adipose-derived mesenchymal stem cells could elevate the level of IL-10 in serum (7 d:t =13.93,P ＜ 0.05) and increase the percentages of CD4/CD25/Foxp(3)-positive regulatory T cells in both peripheral blood (3.5 d:t =7.72,7 d:t=11.11,10 d:t =6.99,P ＜0.05) and thymus (7 d:t =16.17,10 d:t =12.12,P＜ 0.05).Moreover,infiltration of inflammatory cells and deposition of collagens within irradiated small intestine were mitigated by adipose-derived mesenchymal stem cells.Conclusions Adipose-derived mesenchymal stem cells were capable of curing radiation enteritis.

Reflection on the education for clinical postgraduates with professional degree majoring in ;general practice / 中华医学教育探索杂志

General practice is a clinical practice which integrates a variety of disciplines and aims at providing basic health care services for individuals, families and communities. General prac-tice in China is now experiencing increasing development. In 2011, the Academic Degrees Committee of the State Council approved of the addition of general practice under the category of clinical medicine, initiating the education of postgraduates with professional degree majoring in general prac-tice. Through analyzing supervisor instruction, curriculum, skill training and assessment of postgrad-uates majoring in general practice, this paper thoroughly explored its training mode.

Influence of cytokine combinations on proliferation and differentiation of umbilical cord blood CD34(+) cells into megakaryocytes/platelets in vitro / 中国实验血液学杂志

In order to investigate the influence of cytokine combinations on proliferation and differentiation of human umbilical cord blood CD34(+) cells into megakaryocytes/platelets in vitro, the CD34(+) cells from human umbilical cord blood were amplified in serum-free medium StemSpan(SFEM) supplemented with several cytokine combinations by three-phase culture system. The effects of the cytokine combinations were compared. The results showed that at day 14 of the first culture phase, the CD34(+) cells cultured with cytokine combinations SCF + TPO + FL + IL-3 were amplified (11 000 ± 1 000) times, which were significantly higher than that of cells cultured with SCF + TPO + FL, but were not significantly different from that of cells cultured with SCF + TPO + IL-3 or SCF + TPO + FL + IL-3+ hydroxyl-corticosteroids. At day 7 of the second culture phase, the CD34(+) cells cultured with cytokine combination SCF + TPO + FL + IL-11 were amplified by (204666.7 ± 11718.9) times, which were significantly higher than that of cells cultured with SCF + TPO + FL + IL-3, but were not significantly different from that of cells cultured with SCF + TPO + FL + IL-11 + BMP4 + VEGF. At day 3 and day 6, the CD34(+) platelet-like cells accounted for about (39.8 ± 1.9)%, (39.7 ± 2.6)% and (25.5 ± 1.4)%, (23.1 ± 3.5)% cultured with SCF + TPO + FL + IL-11 and SCF + TPO + FL + IL-11 + BMP4 + VEGF, and significantly higher than that of the cells cultured with SCF + TPO + FL + IL-3. It is concluded that the cytokine combination of SCF + TPO + FL + IL-3 is most suitable cytokines combination for the amplification of CD34(+) hematopoietic progenitor cells. The cytokine combination of SCF + TPO + FL + IL-11 is preferred for the proliferation and differentiation of megakaryocytes, this study lays an experimental basis for investigating the proliferation and differentiation of CD34(+) into megakaryocytes/platelets in vitro.