OBJECTIVE To evaluate the efficacy and safety of letermovir in preventing cytomegalovirus(CMV)infection after allogeneic hematopoietic stem cell transplantation(allo-HSCT).METHODS A retrospective cohort study was conducted,enrolling patients who underwent allo-HSCT at the Department of Hematology,Shanghai General Hospital Affiliated to Shanghai Jiao Tong University School of Medicine,from August 30,2022,to February 21,2024.Patients who initiated letermovir prophylaxis within 28 days post-transplantation were assigned to the experimental group(99 cases),while those who did not initiate letermovir within this period were assigned to the control group(18 cases).The incidence and clinical characteristics of CMV infection(including the number of CMV infection cases,the number of cases progressing to CMV disease,recurrent CMV disease,onset time of CMV infection,and treatment duration),immune function recovery within 120 days post-transplantation,and the occurrence of transplantation-related complications(including CD4+and CD8+T-cell recovery,Epstein-Barr virus infection,acute graft-versus-host disease,human herpesvirus 6 infection,and posttransplant lymphoproliferative disorders)and adverse events were recorded.Univariate and multivariate Cox regression analyses were performed to identify factors influencing CMV infection.RESULTS A total of 117 patients were included,among whom 15 developed CMV infection,5 progressed to CMV disease,and 2 experienced recurrent CMV disease.The CMV infection rate in the experimental group was significantly lower than that in the control group(P＜0.001),and the onset time of CMV infection was significantly delayed(P=0.014).The proportion of patients with CD4+T-cell counts≥200 cells/μL in the experimental group was significantly lower than that in the control group(P=0.022).During the follow-up period,elevated creatinine levels were observed in 1 patient,and nausea and vomiting were observed in 2 patients.Multivariate Cox regression analysis revealed that the use of high-dose corticosteroids was a risk factor for CMV infection(HR=6.230,95%CI of 1.255-30.926,P=0.025),while initiating letermovir within 28 days post-transplantation was a protective factor(HR=0.125,95%CI of 0.045-0.348,P＜0.001).CONCLUSIONS Early initiation of letermovir after allo-HSCT significantly reduces the CMV infection rate and delays the onset of infection,with favorable short-term safety.

BACKGROUND:Exosomes derived from human umbilical cord mesenchymal stem cells are widely used for bone repair and reconstruction,significantly enhancing osteogenesis and promoting angiogenesis.OBJECTIVE:To explore the mechanisms of exosomes derived from human umbilical cord mesenchymal stem cells in the treatment of osteoporotic fractures.METHODS:H uman umbilical cord mesenchymal stem cells were extracted using tissue block culture method.Exosomes derived from human umbilical cord mesenchymal stem cells were extracted using ultracentrifugation method for identification.Thirty 12-week-old female SD rats were randomly divided into sham-operated group(n=6)and ovariectomized group(n=24).Osteoporosis model was established by castration in the ovariectomized group.12 weeks after modeling,6 rats in the ovariectomized group and 6 rats in the sham-operated group were randomly selected for Micro-CT and hematoxylin-eosin staining to verify the models.After verification,the remaining 18 rats in the ovariectomized group were randomly assigned to three groups to establish osteoporotic fracture models.The fracture end was separately injected with PBS(PBS group),exosomes at 1.5×1011 particles/mL(low-concentration exosome group),and 3×1011 particles/mL(high-concentration exosome group).Four weeks after operation,fracture healing and bone angiogenesis were evaluated by imaging and histological observations.RESULTS AND CONCLUSION:(1)In the gross specimens,compared with the PBS group,the exosome group had faster fracture healing and more callus formation.(2)The X-ray score of fracture healing in the exosome group was significantly higher than that in the PBS group,and the difference was significant(P＜0.05).(3)Micro-CT three-dimensional imaging:Compared with the PBS group,the fracture healing in the exosome group was accelerated and the callus formation was significantly increased;the bone volume fraction in the exosome group was significantly higher than that in the PBS group,and the difference was significant(P＜0.01).(4)Hematoxylin-eosin staining and Masson's trichrome staining showed that bone trabeculae and the new bone tissue in the exosome group were more than those in the PBS group.(5)Immunohistochemical staining showed that the expression of CD31 and osteocalcin in the exosome group was significantly higher than that in the PBS group.The high-concentration exosome group had a higher density of new blood vessels,more callus formation,and faster fracture healing than the low-concentration exosome group,showing a concentration-dependent manner.The results show that exosomes derived from human umbilical cord mesenchymal stem cells can promote the repair of osteoporotic fracture by enhancing the angiogenesis and osteogenesis.The mechanism may be related to the increased expression of CD31 and osteocalcin.

BACKGROUND:Exosomes derived from human umbilical cord mesenchymal stem cells are widely used for bone repair and reconstruction,significantly enhancing osteogenesis and promoting angiogenesis.OBJECTIVE:To explore the mechanisms of exosomes derived from human umbilical cord mesenchymal stem cells in the treatment of osteoporotic fractures.METHODS:H uman umbilical cord mesenchymal stem cells were extracted using tissue block culture method.Exosomes derived from human umbilical cord mesenchymal stem cells were extracted using ultracentrifugation method for identification.Thirty 12-week-old female SD rats were randomly divided into sham-operated group(n=6)and ovariectomized group(n=24).Osteoporosis model was established by castration in the ovariectomized group.12 weeks after modeling,6 rats in the ovariectomized group and 6 rats in the sham-operated group were randomly selected for Micro-CT and hematoxylin-eosin staining to verify the models.After verification,the remaining 18 rats in the ovariectomized group were randomly assigned to three groups to establish osteoporotic fracture models.The fracture end was separately injected with PBS(PBS group),exosomes at 1.5×1011 particles/mL(low-concentration exosome group),and 3×1011 particles/mL(high-concentration exosome group).Four weeks after operation,fracture healing and bone angiogenesis were evaluated by imaging and histological observations.RESULTS AND CONCLUSION:(1)In the gross specimens,compared with the PBS group,the exosome group had faster fracture healing and more callus formation.(2)The X-ray score of fracture healing in the exosome group was significantly higher than that in the PBS group,and the difference was significant(P＜0.05).(3)Micro-CT three-dimensional imaging:Compared with the PBS group,the fracture healing in the exosome group was accelerated and the callus formation was significantly increased;the bone volume fraction in the exosome group was significantly higher than that in the PBS group,and the difference was significant(P＜0.01).(4)Hematoxylin-eosin staining and Masson's trichrome staining showed that bone trabeculae and the new bone tissue in the exosome group were more than those in the PBS group.(5)Immunohistochemical staining showed that the expression of CD31 and osteocalcin in the exosome group was significantly higher than that in the PBS group.The high-concentration exosome group had a higher density of new blood vessels,more callus formation,and faster fracture healing than the low-concentration exosome group,showing a concentration-dependent manner.The results show that exosomes derived from human umbilical cord mesenchymal stem cells can promote the repair of osteoporotic fracture by enhancing the angiogenesis and osteogenesis.The mechanism may be related to the increased expression of CD31 and osteocalcin.

Objective:To analyze the trend of medication use in patients with ulcerative colitis (UC) in recent ten years in at Xijing Hospital, Air Force Military Medical University.Methods:From 2010 to 2019, the clinical data of 1 425 patients diagnosed with UC in the Department of Gastroenterology at Xijing Hospital, Air Force Medical University, were retrospectively collected. According to the period of medication, the UC patients were divided into year 2010 to 2014 group and year 2015 to 2019 group. The general information and the medication trend of year 2010 to 2014 group and year 2015 to 2019 group were analyzed. And then according to gender and age (<40 years old and ≥40 years old), patients were divided into subgroups and analyzed. Independent sample t test and chi-square test were used for statistical analysis. Results:The number of UC patients of year 2010 to 2014 group and year 2015 to 2019 group was 369 and 1 056, respectively. The percentages of patients in remission of the two groups were 9.5% (35/369) and 12.0% (127/1 056), respectively; the percentages of mild patients were 40.4% (149/369) and 41.6% (439/1 056), respectively; the percentages of moderate patients were 37.4% (138/369) and 28.9% (305/1 056), respectively; the percentages of severe patients were 12.7% (47/369) and 17.5% (185/1 056), respectively. There was no significant difference in the proportion of UC patients with different degrees between year 2010 to 2014 group and year 2015 to 2019 group ( P>0.05). There were no significant differences in the age and proportion of female between the year 2010 to 2014 group and year 2015 to 2019 group ((46.2±15.3) years old vs. (44.6±30.6) years old; 45.8%, 169/369 vs. 44.8%, 473/1 056; both P>0.05). The utilization rates of 5-aminosalicylic acid (5-ASA), glucocorticoid, immunosuppressants, and biological agents of the year 2015 to 2019 group were all higher than those of the year 2010 to 2014 group (96.8%, 1 022/1 056 vs. 90.0%, 332/369; 29.9%, 316/1 056 vs. 14.6%, 54/369; 8.4%, 89/1 056 vs. 2.4%, 9/369; 4.8%, 51/1 056 vs. 0.5%, 2/369, respectively), and the differences were all statistically significant ( χ2=26.766, 33.256, 15.315 and 14.038, all P<0.01). Within each of the year 2010 to 2014 group and the year 2015 to 2019 group, there were no significant differences between the female and male in the age, utilization rates of 5-ASA, glucocorticoid, immunosuppressants and biological agents ((47.2±13.6) years old vs. (45.3±16.5) years old, (43.1±12.9) years old vs. (45.8±39.5) years old, 88.8%, 150/169 vs. 91.0%, 182/200; 96.8%, 458/473 vs. 96.7%, 564/583; 13.6%, 23/169 vs. 15.5%, 31/200; 28.3%, 134/473 vs. 31.2%, 182/583; 2.4%, 4/169 vs. 2.5%, 5/200; 7.0%, 33/473 vs. 9.6%, 56/583; 0 vs. 1.0%, 2/200; 5.3%, 25/473 vs. 4.5%, 26/583; all P>0.05). In the patients aged≥40 years old of the year 2010 to 2014 group, the proportion of females was higher than that of the patients aged <40 years old (50.2%, 121/241 vs. 37.5%, 48/128), and the utilization rate of 5-ASA in patients aged ≥40 years old was lower than that of patients aged <40 years old (85.9%, 207/241 vs. 97.7%, 125/128), and the differences were statistically significant ( χ2=5.438 and 12.824, P=0.020 and P<0.01). In the year 2010 to 2014 group, there were no statistically significant differences in the utilization rates of glucocorticoid, immunosuppressants and biological agents between patients aged ≥40 years old and patients aged <40 years old (13.7%, 33/241 vs. 16.4%, 21/128; 2.1%, 5/241 vs. 3.1%, 4/128; 0 vs. 1.6%, 2/128; all P>0.05). In the year 2015 to 2019 group, the utilization rate of biological agents in patients aged≥40 years old was lower than that in patients aged<40 years old (3.7%, 23/630 vs. 46.5%, 198/426), and the difference was statistically significant ( χ2=4.721, P=0.030). In the year 2015 to 2019 group, there were no statistically significant differences in female proportion, utilization rates of 5-ASA, glucocorticoid, immunosuppressants and biological agents between patients aged≥40 years old and patients aged <40 years old (43.7%, 275/630 vs. 46.5%, 198/426; 96.0%, 605/630 vs. 97.9%, 417/426; 29.7%, 187/630 vs. 30.3%, 129/426; 8.6%, 54/630 vs. 8.2%, 35/426; all P>0.05). Conclusions:Compared with year 2010 to 2014, the number of UC patients remarkably increased in the year 2015 to 2019 in the Department of Gastroenterology, Xijing Hospiatal, Air Force Medical University. The utilization rates of 5-ASA, glucocorticoid, immunosuppressants and biological agents all increased in UC patients. The medication trends of UC patients with different gender were almost the same. The medication trends of UC patients with different age were different.

Objective:To study the regulatory effect of Wumen-Yiji powder on 5-hydroxytryptamine (5-HT) signal transduction system in intestine and hypothalamus of diarrhea irritable bowel syndrome (IBS-D) model rats. Methods:Sixty male SD rats were randomly divided into blank group (10 rats) and diarrhea irritable bowel syndrome group (50 rats). The diarrhea irritable bowel syndrome group formed the diarrhea irritable bowel syndrome model after 2 weeks of senna leaf gavage and restraint stress. They were randomly divided into model group, deshute group (1.5 mg/kg), low, medium and high dose group of Wumen-Yiji San (6, 12, 24 g/kg), with 10 rats in each group. After continuous administration for 2 weeks, the contents of 5-HT in serum, colon and hypothalamus were detected by ELISA; HE staining was used to observe the pathological changes of colon in each group. The protein and mRNA levels of tryptophan hydroxylase 1 (TPH-1), serotonin receptor 3 (5-HT3R), serotonin receptor 4 (5-HT4R), serotonin transporter (SERT) in colon and hypothalamus were detected by Western blot and RT-PCR, respectively. Results:Compared with the model group, the pathological morphology of colon in each treatment group was improved. Compared with the model group, the level of 5-HT in serum and colon significantly decreased ( P<0.05), and the level of 5-HT in hypothalamus of rats in the low, medium, high dose group of Wumen-Yiji San significantly increased ( P<0.05). The expression of TPH-1, 5-HT3R and 5-HT4R protein significantly decreased ( P<0.05), and the expression of SERT protein in the medium, high dose group of Wumen-Yiji San significantly increased ( P<0.05). The expression of TPH-1, 5-HT3R and 5-HT4R protein in hypothalamus increased ( P<0.05), and the expression of SERT protein in the high dose group of Wumen-Yiji San significantly decreased ( P<0.05). The mRNA levels of TPH-1 (4.778 ± 0.604, 3.278 ± 0.668, 1.670 ± 0.361 vs. 6.877 ± 0.148), 5-HT3R (3.807 ± 0.463, 2.697 ± 0.455, 1.132 ± 0.136 vs. 6.322 ± 0.778), 5-HT4R (4.521 ± 0.234, 2.801 ± 0.351, 1.331 ± 0.142 vs. 6.741 ± 0.293) in colon tissue of low, medium and high dose groups of Wumen-Yiji San decreased ( P<0.05). The level of 5-HT4R mRNA (0.616 ± 0.208, 0.726 ± 0.226 vs. 0.521 ± 0.062) increased ( P<0.05), and the level of SERT mRNA (1.563 ± 1.023 vs. 2.612 ± 1.035) in medium, high dose group of Wumen-Yiji San decreased ( P<0.05). Conclusion:The result showed that Wumen-Yiji San could regulate the expression of 5-HT signaling system relating proteins and mRNA in the colon and hypothalamus of IBS-D rats within a certain dose range, so as to improve the symptoms of IBS-D.

Objective: To evaluate the postoperative quality of life after surgery of patients with hepatic hemangioma. Methods: The retrospective and descriptive study was conducted. The clinical data of 104 patients who underwent surgery for hepatic hemangioma at Shengjing Hospital of China Medical University from September 2011 to February 2017 were collected. There were 28 males and 76 females, aged (49±8)years, with a range of 27-78 years. Enucleation of hepatic hemangioma or hepatectomy was selected according to tumor location of patients. Observation indicators: (1) surgical and postoperative situations; (2) assessment of quality of life in patients; (3) assessment of quality of life in patients comorbid with other chronic digestive diseases. Measurement data with normal distribution were represented as Mean±SD, and measurement data with skewed distribution were represented as M (range). Repeated data were analyzed using repeated ANOVA. Count data were represented as absolute numbers. Results: (1) Surgical and postoperative situations: of 104 patients, 67 underwent enucleation of hepatic hemangioma, 37 underwent hepatectomy. The tumor diameter, volume of intraoperative blood loss, duration of postoperative hospital stay were (10±4)cm, 200 mL (range, 10-3 000 mL), (11±5)days. Seven patients had complications, including 5 of massive abdominal ascites, 1 of abdominal infection, and 1 of pulmanory obstruction. There was no death occurred. (2) Assessment of quality of life in patients with hepatic hemangioma: the total scores of Gastrointestinal-related Quality of Life Index (GIQLI), the scores of subjective symptoms, physiological status, mental and psychological status, and social activities were 121.0±8.3, 69.2±4.1, 18.5±2.6, 19.5±1.8, and 13.8±1.4 at preoperation. The above indices were 121.9±6.9, 71.2±3.8, 17.2±2.5, 19.6±2.3, and 13.8±1.3 of 104 patients with hepatic hemangioma at one month after surgery, respectively. The above indices were 127.8±6.2, 73.2±3.6, 19.8±2.5, 20.8±2.4, and 14.1±1.0 at 6 months after surgery. There were significant differences in changing trends of above indices (F=68.4, 64.6, 71.4, 17.8, 3.3, P<0.05). The scores of subjective symptoms and physiological status at one month after surgery showed significant differences compared with those of preoperation (t=-5.780, 6.640, P<0.05), but the total scores of GIQLI, the scores of mental and psychological status, and social activities showed no difference (t=-1.569, -0.705, 0.240, P>0.05). The total scores of GIQLI, scores of subjective symptoms, physiological status, and mental and psychological status at 6 months after surgery showed significant differences compared with those of preoperation (t=-8.897, -9.919, -5.375, -5.024, P<0.05), but the score of social activities showed no difference(t=-1.919, P>0.05). The total scores of GIQLI, the scores of subjective symptoms, physiological status, mental and psychological status, and social activities at 6 months after surgery were significantly different from those at one month after surgery (t=-10.835, -6.787, -12.277, -4.560, -2.476, P<0.05). (3) Assessment of quality of life in hepatic hemangioma patients comorbid with other chronic digestive diseases: 29 of 104 patients were comorbid with chronic gastritis, biliary diseases, and appendicitis. For the 29 patients comorbid with other chronic digestive diseases, the total scores of GIQLI, the scores of subjective symptoms, physiological status, mental and psychological status, and social activities were 117.5±7.5, 67.8±4.2, 17.4±2.2, 19.0±1.5, and 13.2±1.3 at preoperation. The above indices were 118.7±6.9, 69.5±4.5, 16.7±2.0, 19.2±1.9, and 13.2±1.3 at one month after surgery, respectively. The above indices were 124.6±6.5, 70.9±4.5, 19.8±2.1, 19.9±2.4, and 14.0±0.9 of 29 patients comorbid with other chronic digestive diseases at 6 months after surgery. There were significant differences in changing of the total scores of GIQLI, the scores of subjective symptoms, physiological status, and social activities (F=15.0, 9.0, 27.6, 7.5, P<0.05), except the score of mental and psychological status (F=1.6, P>0.05) . The scores of subjective symptoms and physiological status at one month after surgery showed significant differences compared with those of preoperation (t=-2.612, 2.191, P<0.05), but the total scores of GIQLI, the scores of mental and psychological status, and social activities showed no difference (t=-1.128, -0.587, -0.157, P>0.05). The total scores of GIQLI, scores of subjective symptoms, physiological status, and social activities at 6 months after surgery showed significant differences compared with those of preoperation (t=-4.002, -3.441, -4.604, -3.266, P<0.05), but the score of mental and psychologica status showed no difference (t=-1.522, P>0.05). The total scores of GIQLI, the scores of subjective symptoms, physiological status, and social activities at 6 months after surgery were significantly different from those at one month after surgery (t=-4.819, -2.313, -7.081, -3.172, P<0.05), but the score of mental and psychological status had no significant difference (t=-1.154, P>0.05). Conclusions The quality of life in patients with hepatic hemangioma can be improved by surgery. Surgical treatment is still effective for improvement of the total scores of GIQLI, the scores of subjective symptoms, physiological status, and social activities for those combined with other digestive diseases.

Translational medicine means that to establish a bridge between fundamental research and clinical medicine through bidirectional translation path in order to promote the translation and application from fundamental research to clinical medicine.The purpose of traditional Chinese medicine (TCM) translational model is to collate and build one multidimensional TCM translational model,rationality carry out the research on TCM translation.Three paths have been confirmed,where are from literature research to clinical verification,from clinical application to clinical verification,and from experiment to clinical verification.In this research,methodology of one path mcntioned above could be established,which is the key technology of translational medicine.Take constipation,insomnia,and post-flu cough as target diseases to investigate the herbal compounds which could be qualified for clinical application based on preliminary work.This research not only provided clinical data to TCM translation,but also established one methodology of TCM translation path--"from experiment to clinical verification".

Based on the innovation of modern science and technology and concepts,the study of innovative Chinese medicine research has not been divorced from the traditional thinking of natural medicine research,in the theoretical system of traditional Chinese medicine,there was basically no inheritance and lack of innovation,which made the research of new medicine of traditional Chinese medicine fall into an awkward position.We sum up our experience in 1 1th Five-Year and 12th Five-Year,combined with the upcoming 13th Five-Year of the research and development idea of component Chinese Medicine,analyzed the impact of 3 aspects on the modernization of Chinese traditional medicine and put forward the solving methods.① The scientific screening of high-level candidate prescriptions has always been the bottleneck of the development of new Chinese medicine and the basic premise of modernization of Chinese Medicine;② It is an important outlet and measure to promote the modernization of traditional Chinese medicine to vigorously carry out the research on the transformation of traditional Chinese medicine and to formulate a scientific and rational mode of transformation of traditional Chinese medicine;③ From the point of view of the development and reform of component traditional Chinese medicine,it is necessary to follow the basic theory of traditional Chinese medicine,and comprehensively to consider the characteristics of the components of Chinese medicine,and to lay the foundation for the screening and research and development of Chinese herbal medicines

AIM: To assess the degree of oxidative damage during acute myocardial infarction and reperfusion, and to clarify the protective effect of Tongxinluo in mini-swine model. METHODS: Thirty mini-swines were randomized into 5 study groups: sham group, model group, low dose (0.05 g·kg~(-1)·d~(-1)), medium dose (0.2 g·kg~(-1)·d~(-1)) and high dose (0.5 g·kg~(-1)·d~(-1)) of Tongxinluo groups (pretreated with Tongxinluo for 3 d). Animals except in sham group were subjected to 3 h of coronary occlusion followed by 1 h of reperfusion. Concentrations of total antioxidative capability (T-AOC), total superoxide dismutase (T-SOD), reduced glutathione (GSH) and malondialdehyde (MDA) in blood sample and the myocardium were measured. RESULTS: (1) T-AOC, T-SOD and GSH in serum significantly decreased (all P<0.05), while MDA significantly increased (P<0.01) at 3 h after AMI in comparison with those at baseline. Compared to those at 3 h after AMI, the contents of T-AOC, T-SOD and GSH at 1 h after reperfusion significantly decreased (all P<0.01), accompanied by increase of MDA (P<0.01). (2) Compared to those in normal area, levels of T-AOC, T-SOD and GSH in reperfusion myocardium decreased significantly (all P<0.01) and MDA increased significantly (P<0.01). T-AOC, T-SOD and GSH in no-reflow myocardium further decreased (all P<0.01) and MDA increased (P<0.01) as compared to those in reperfusion myocardium. (3) Compared to model group, medium dose of Tongxinluo increased the contents of T-AOC and T-SOD and reduced MDA production in serum at 3 h after AMI (all P<0.05), while medium dose of Tongxinluo increased T-SOD level at 1 h after reperfusion (P<0.05). High dose of Tongxinluo increased the levels of T-AOC and T-SOD and decreased MDA content in serum at 3 h after AMI and 1 h after reperfusion (all P<0.05). (4) The medium dose of Tongxinluo increased T-AOC content (P<0.05) and reduced MDA (P<0.05) in reperfusion myocardium, while high dose of Tongxinluo increased T-AOC, T-SOD and GSH (all P<0.05), reduced MDA (P<0.01) in reperfusion myocardium, and also increased T-AOC, T-SOD (all P<0.05), reduced MDA (P<0.01) in no-reflow area as compared to those in model group. CONCLUSION: Impairment of antioxidant defense system in vivo and imbalance of redox homeostasis in myocardium region might play an important role in the pathogenesis of no-reflow after myocardial acute infarction following reperfusion. Tongxinluo protects myocardium from reperfusion injury by improving antioxidant defense and attenuating oxidative damage.

Objective To investigate the ability of magnetic resonance imaging (MRI) in tracking magnetically labeled mesenchymal stem cells (MR-MSCs) in a swine myocardial infarction (MI) model.Methods Adult Chinese mini-pigs (n = 6) were subjected to open-chest experimental MI operation.Their antegeneic bone marrow-derived mesenchymal stem cells ( MSCs ) was cultured and doubly labeled with ferumoxides and DAPL On the 14 th day after MSCs transplantation, the size and location of the myocardial infarction were assessed by using delayed-enhancement MRI (DE-MRI). Then the labeled MSCs were injected intramyocardially into peri-infarct zone and normal myocardium. At 24 hrs and 3 weeks after injection, the contrast and the volume of the MR-MSCs hypointense lesion from the MR images were acquired, and the contrast was determined using the difference in signal intensity between the hypointense and normal myocardium divided by signal intensity of the normal region.After humane euthanasia, the heart was excised and histology corresponding to MRI slices that demonstrated MR-MSCs lesions was performed.Repeated-measures ANOVA and a paired t test were used for comparison of the contrast and the volume of the MR-MSCs hypointense lesion at different time points. Comparisons between independent groups were performed with the standard Student t test.Results The labeling efficiency of ferumoxides and DAPI was 100% . On the 14 th day after the MI operation, the average percentage of infracted myocardial area was (33.6±8.9)% .Twenty- four hours after MSCs transplantation, MSCs injection sites appeared as ovoid hypointensive lesions with sharp border on T2 * images. At 24 h after injection, the signal contrast [(67.00±5.48)% vs (61.92 ±7.76)%,t = 1.65,P =0.1158] and the size [(0.56 ±0.24) cm2 vs (0.52 ± 0.25 ) cm2, t = 0.39, P = 0.7044 ] of the lesions showed no statistical difference between the peri infarct zone and the normal myocardium.At 3 weeks after injection, the signal contrast decreased and the size diminished both in the peri-infarct zone and in the normal myocardium. Moreover, the contrast of the lesions in peri-infarct zone decreased more significantly than that in normal myocardium [(26.88 +7.27)%vs (15.00 :t:4.51)%, F =20.08, P =0.0003].Post mortem analysis found the fluorescontly labeled MSCs demonstrated on histological sections.There were much more dense fluorescently labled MSCs per high power fields at injection sites of normal myocardium than at injection sites of peri-infarct zone [ (106 ±25 )/HPF vs ( 143 ± 31 )/HPF, t = - 2.47, P = 0.0293 ].In MSCs injection sites of the peri-infarct zone,the capillary density was significantly higher than that in control sites [ (13.4 ± 4.0 )/HPF vs (9.4 ±3.1 )/HPF, t = 2.49, P = 0.0229].At 3 weeks after injection, ferumoxide was contained within partial original MSCs.Conclusion Magnetic resonance imaging of MSCs is a feasible method for the in vivo tracking of transplanted stem cells and could reflect the tendency of the local stem cell quantity, but there still has limitation for the semi-quantitation of the transplanted stem cells.