BACKGROUND:Several studies have demonstrated that bone marrow mesenchymal stem cells (BMSCs) inhibit the proliferation and activation of T lymphocytes, exerting a role of negative immunological regulation. OBJECTIVE: To induce rat BMSCs to differentiate into neuron-like cells in vitro using all-trans retinoic acid and to investigate the effects of differentiated cells on T lymphocyte proliferation.DESIGN, TIME AND SETTING: A cytological in vitro observation was performed in Guangdong Medical College in March 2008.MATERIALS: Two male 4-week-old Sprague Dawley rats were provided by the Laboratory Animal Center of Guangdong Medical College. Fresh healthy human blood was provided by the Department of Clinical Laboratory, Guangdong Medical College. METHODS: Rat BMSCs were isolated by adherent method and were passaged in vitro. Cells of passage 5 were pre-induced with Low glucose-dulbecco's modified eagle's medium (LG-DMEM) containing 0.3 mg/L all-trans retinoic acid and 10% fetal bovine serum. Twenty-four hours later, aforementioned LG-DMEM was discarded and LG-DMEM containing 0.6 mg/L all-trans retinoic acid was added to induce cells differentiation into neuron-like cells. Fresh healthy human blood was taken to prepare responding cells. Rat BMSCs, as stimulator cells, were included for one-way mixed lymphocyte reaction. Four groups were designated. Control group: 100 μL of responding cells at a concentration of 1×109/L; Experimental group 1:1×104 neuron-like cells + 100 μL of responding cells; Experimental group 2:1×105 neuron-like cells + 100 μL of responding cells; Experimental group 3:1×106 neuron-like cells + 100 μL of responding cells.MAIN OUTCOME MEASURES: Morphological observation of induce-differentiated cells, identification of nerve cells, and one-way mixed lymphocyte reaction results.RESULTS: Fifty minutes after addition of inducing medium, under the optical microscope, BMSCs exhibited a typical morphology of perikaryon. Three hours later, most of cells became into bipolar or multipolar neuron-like cell appearance with cell bodies and processes. Immunocytochemical staining results showed that majority of cells exhibited neuron specific enolase- and nestin-positive expression and glial fibrillary acidic protein-negative expression. Compared with the control group, radionuclide counts per minute were significantly reduced in each experimental group (P<0.05). There was significant difference in radionuclide counts per minute between experimental groups (P<0.05). With increasing BMSCs amount, the inhibitory effects on T lymphocyte proliferation were more evident.CONCLUSION: AII-trans retinoic acid can induce neuron-like cell differentiation of rat BMSCs in vitro. The neuron-like cells can inhibit human T lymphocyte proliferation in a dose-dependent manner.

Objective:Marrow mesenchymal stem cells differentiates into neuron-like cells when induced by Gastrodia,which verifies the multipotentiality of the stem cells.Here to detect the immunogenic properties of the neuron-like cells after differentiation.Methods:Human mesenchymal stem cells were isolated from bone marrow by wall sticking method,amplified by in vitro culture,and differentiated into neuron-like cells by oriented induction with Gastrodia.The morphology of cells was observed under light microscopy.Neuron-specific enolase (NSE),nestin and glial fibrillary acidic protein (GFAP) were detected by imnunocytochemistry.The expression of HLA-DR protein after induction was tested by flow cytometry(FCM).The immunogenic properties of the neuron-like cells induced from hMSCs were detected by one-way mixed lymphocyte reaction(MLR).Results:Human mesenchymal stem cells could be separated and amplified in vitro.After being induced by Gastrodia for 3 hours,most of the cells would be differentiated into neuron-like cells,revealing cytodendrite.By immunochemical staining,the cells showed positive of NSE,nestin,and negative of GFAP.HLA-DR was not detectable on differentiated hMSCs by FCM.MLR assays demonstrate that differentiated hMSCs fail to stimulate proliferative response of hPBLs.Conclusion:Human mesenchymal stem cells could be induced to differentiate into neuron-like cells by Gastrodia.MLR assays demonstrate that differentiated hMSCs fail to stimulate proliferative response of hPBLs.They are low immunogenic.

Objective To study the efficacy of laparoscopic tumor resection combined with iodine-125 and radiofrequency ablation in the treatment of rectal carcinoma with synchronous hepatic metastasis. Methods There were 30 patients diagnosed as rectal carcinoma with synchronous hepatic metastasis detected by CT scan. Hepatic metastases were confirmed by needle biopsy under laparoscopy. Laparoscopic radical resection of rectal carcinoma and metastatic hepatic tumors was performed. Those metastatic tumors that could not be resected were managed by RAF. Iodine-125 was planted in the tumors' site. Results Seven new hepatic metastases were found by the laparoscopic ulstrasound during the operation. 8 hepatic metastatic lesions were removed, 25 tumors located in the right liver were managed by RAF. All patients were followed-up from 12 to 25 months(average 22. 3 months), Local recurrence was found in 6 patients, the 1-year survival rate was 73% (22/30). Conclusions Laparoscopic excision, Iodine-125 and radiofrequency ablation in the treatment of rectal carcinoma with synchronous hepatic metastasis is safe、effective、minimally invasive.

Objective To explore the insulin resistance(IR),serum cortisol.level and circadian secretion rhythm in the patients with pituitary adenoma(PA).Methods Sixty-seven patients with PA in this hospital from October 2016 to April 2017 were selected as the observation group,including 23 cases of pituitary Cushing syndrome,15 cases of growth hormone adenoma,16 cases of prolactinoma and 13 cases of non-functioning adenoma.Contemporaneous 49 individuals undergoing healthy physical examination were selected as the control group.The biochemical indexes of fasting plasma glucose(FPG),fasting insulin(FINS) and serum cortisol were measured and the homeostasis model assessment for insulin resistance(HOMA-IR) was determined.The correlation between insulin resistance and serum cortisol was analyzed.Results The incidence rate of cortisol circadian rhythm disorder in the observation group was 58.21％,the level of fasting serum cortisol in abnormal secretion rhythm of PA group was higher than that in normal secretion rhythm of PA group and control group(P＜0.05);the levels of FINS and HOMA-IR in the pituitary Cushing syndrome and growth hormone adenoma group were higher than those in the control group,the correlation analysis showed that HOMA-IR in PA patients was positively correlated with fasting serum cortisol level and FINS level(P＜0.05).Conclusion The IR occurrence exists in pituitary Cushing syndrome and growth hormone adenoma,which may be closely correlated with serum cortisol increase.

Background:There is no comparison of the current status of Helicobacter pylori(Hp)infection in different ethnic groups in terms of families and their individuals.Aims:To investigated for the first time the status of Hp infection in Tibetan and Han Chinese families at the household level.Methods:A questionnaire was used to investigate factors associated with Hp in 50 Tibetan families in Ya'an,Sichuan Province,and 50 Han Chinese families in Chongqing Municipality.13C-urea breath test was used to detect Hp infection.Results:The individual and household Hp positivity rates of the Tibetan population in southwest China were 47.10%and 80%,which were significantly higher than those of the Han Chinese,which were 27.81%and 58%(P<0.05).However,the difference between Han and Tibetan in individual and household infection rates was not statistically significant.There are differences between Han Chinese and Tibetans in terms of infection status,geography,economic conditions,living habits and levels of hygiene.Infection was concentrated in certain family groups rather than being evenly distributed in the population.Conclusions:The current detection rate of Hp infection in individuals and families of Tibetan residents is significantly higher than that of Han Chinese,while the proportion of infected individuals is not statistically different.Transmission of Hp is characterized by family aggregation.There are differences in infection status,geographical environment,economic conditions,living habits and hygiene levels between Chinese and Tibetan families.

Objective This study aimed to evaluate the safety and efficacy of video-assisted thoracoscopic bipolar radio-frequency ablation in the treatment of isolated paroxysmal atrial fibrillation.Methods From September 2010 to December 2016,Seventy-two consecutive patients with paroxysmal atrial fibrillation underwent video-assisted thoracoscopic bipolar radio-frequency ablation at Fuwai Hospital.There were 50 males and 22 females with an average age of(56.5 ± 10.5) years and duration of atrial fibrillation with (6.5 ± 4.8) years.45 patients had previous catheter ablation.The patients were followed up at postoperative 3 months,6 months,1 year and annually.Success of ablation was defined as sinus rhythm and no duration of ≥30 s for rapid atrial arrhythmias,including atrial fibrillation,atrial flutter or atrial tachycardia in 24 h Holter examination.Univariate and multivariate logistic regression models were used to analyze the risk factors for atrial fibrillation recurrence.Results One patient converted to sternotomy due to bleeding on operation.All patients were successfully discharged.69 patients completed follow-up,with an average follow-up of(28 ± 18)months(3-60 months).The overall success rate was 73.9％,and the success rate without antiarrhythmic drug was 62.3％.Subgroup analysis showed that the success rate was 80％ when left atrial anterior and posterior diameter(LAD) ≤40 mm,and 57.9％ when LAD ＞ 40 mm (P =0.035).Multivariate logistic regression analysis showed that LAD ＞40 mm was an independent risk factor for postoperative recurrence of atrial fibrillation.Conclusion Video-assisted thoracoscopic bipolar radiofrequency ablation is a safe and effective method for the treatment of paroxysmal atrial fibrillation,especially in patients with LAD≤40 mm.