Biomedical subjects
Publications and source records attributed to Jun Jin.
Magnetic Fe nanoparticle functionalized water-soluble multi-walled carbon nanotubules (MWNTs) were prepared, characterized and used for the removal of aromatic compounds in water and re-use.
The presence within bone marrow of a population of mesenchymal stem cells (MSCs) able to differentiate into a number of different mesenchymal tissues, including bone and cartilage, was first suggested by Friedenstein nearly 40 years ago. Since then MSCs have been demonstrated in a variety of fetal and adult tissues, including bone marrow, fetal blood and liver, cord blood, amniotic fluid and, in some circumstances, in adult peripheral blood. MSCs from all of these sources can be extensively expanded in vitro and when cultured under specific permissive conditions retain their ability to differentiate into multiple lineages including bone, cartilage, fat, muscle, nerve, glial and stromal cells. There has been great interest in these cells both because of their value as a model for studying the molecular basis of differentiation and because of their therapeutic potential for tissue repair and immune modulation. However, MSCs are a rare population in these tissues. Here we tried to identify cells with MSC-like potency in human placenta. We isolated adherent cells from trypsin-digested term placentas and examined these cells for morphology, surface markers, and differentiation potential and found that they expressed several stem cell markers. They also showed endothelial and neurogenic differentiation potentials under appropriate conditions. We suggest that placenta-derived cells have multilineage differentiation potential similar to MSCs in terms of morphology and cell-surface antigen expression. The placenta may prove to be a useful source of MSCs.
Hepatocellular carcinoma (HCC) is an aggressive cancer with a poor prognosis. The specific cellular gene alterations responsible for hepatocarcinogenesis are not well known. Previous works showed that loss of TIP30, also called CC3, a putative tumor suppressor, increased the incidence of hepatocellular carcinoma in mice, and some clinical samples of human HCC tissues had aberrant expression of TIP30. Here, we report that the introduction of TIP30 by an adenovirus vector into HCC cell lines that had decreased expressions of TIP30 inhibited cell proliferation, decreased anchorage-dependent growth, suppressed invasion through the extracellular matrix, and inhibited tumorigenesis in nude mice. Moreover, exogenous expression of Tip30 sensitized HCC cells to cytotoxic drugs and to apoptosis induced by tumor necrosis factor-related ligands in vitro. Ectopic expression of TIP30 in HCC cells enhanced p53 expression and decreased Bcl-2/Bcl-xL expression. Treatment of nude mice bearing subcutaneously established HCC tumors with a combination of an adenovirus expressing TIP30 and the cytotoxic drug 5-fluorouracil completely suppressed tumor growth and prolonged survival. In conclusion, TIP30 may play an important role in the suppression of hepatocarcinogenesis by acting as a tumor suppressor. Overexpression of TIP30 might be a promising candidate as a treatment for HCC that would increase sensitivity to chemotherapeutic drugs.
OBJECTIVE: To evaluate the clinical effect of acellular dermal matrix allograft in repairing the oral mucosal defect of immediate implant. METHODS: 51 cases underwent immediate implant surgery for 67 implants right after the teeth or roots extracted. The mucosal defect of implant areas were repaired by acellular dermal matrix. The basal membrane side of acellular dermal matrix was exposed to oral cavity, and another side was attached to the implant and alveolar crest surface. It was intercalated between mucosal flap and alveolar and fixed by iodoform pack or base plate. To understand condition of wound healing the patients were followed up from 4 months to 6 months after operation. The acellular dermal matrix closed wound and histological changes were observed. The implant was followed up months to 4 years. RESULTS: The wounds were completely healed in 54 implant areas, partially healed in 11 implant areas, not healed 2 implant areas. histological examination wasn't differentiation between mucous epithelium and graft epithelium. None of 67 implants showed deterioration in the follow-up of one year. It was no obvious sign of immune rejection. CONCLUSION: The clinical result of acellular dermal matrix in repair the mucosal defect of immediate implant is good, the advantages are not to affect the integration bone with implant, less operation trauma, good esthetics results.
OBJECTIVE: The study investigate the antioxidant probucol on endothelial function in patients with acute coronary syndrome (ACS). METHODS: A total of 49 ACS patients randomly received standard therapy plus probucol (P, n = 24) or standard therapy (C, n = 25). Plasma oxidized low-density lipoprotein (ox-LDL), nitric oxide (NO) and circulating endothelial cells (CEC) were measured. The brachial arterial hyperemia-induced flow mediated dilation (FMD) and sublingual nitroglycerin (NTG) mediated vasodilatations were measured by high resolution ultrasound. These variables were analyzed before and after 3 months therapy. RESULTS: Plasma NO and FMD was significantly increased after 3 months therapy than before therapy [(80.46 +/- 10.24) micromol/Lvs (48.46 +/- 12.24) micromol/L, P < 0.01; (13.46 +/- 1.20)% vs (7.45 +/- 1.02)%, P < 0.05, respectively], while the number of CEC and ox-LDL were significantly decreased (P < 0.01) in P group. These values were similar before and after 3 months in C group. The linear correlation analysis showed that plasma ox-LDL negatively correlated with NO (r = -0.574, P < 0.01) and FMD (r = -0.517, P < 0.01) and positively correlated with CEC (r = 0.385, P < 0.01) in patients received 3 months probucol therapy. CONCLUSIONS: Chronic antioxidant probucol therapy could improve endothelial function in patients with ACS.
OBJECTIVE: To investigate the effect of COX1 and COX2 on angiogenesis and endothelial progenitor cell mobilization in rats with experimental myocardial infarction (MI). METHODS: The rats were randomly divided into 3 groups: MI group, MI plus rofecoxib group and MI plus valeryl salicylate group. At the 7th day after operation, circulating EPCs, plasma VEGF and HIF-1alpha mRNA of ischemic myocardium were measured. At the 28th day post operation, capillary densities were also measured in ischemic myocardium. RESULT: Compared with the MI group and the MI plus valeryl salicylate group, circulating EPCs, plasma VEGF, HIF-1alpha mRNA and capillary densities of ischemic myocardium were all decreased in MI plus rofecoxib group. CONCLUSION: The present study revealed that COX2 play an important role with angiogenesis and endothelial progenitor cell mobilization in rat with experimental MI by modulating expression of VEGF and HIF-1alpha.
BACKGROUND: Previous studies have shown that mesenchymal stem cells (MSCs) transplantation can promote neovascularization and regenerate damaged myocardium. However, it remains unknown whether MSCs seeding can be used to repair injured cellular components in vascular diseases. In this study we explored the feasibility of applying MSCs to endothelium repair in endothelial damage and vasoproliferative disorders. METHODS: Ex vivo model of endothelium repair was developed in which rabbit vascular smooth muscle cells (SMCs) were inoculated into the upper chamber and rabbit endothelial cells (ECs)/human MSCs into the lower chamber of a co-culture system. 3H-TdR incorporation and PCNA protein expression were assayed and migrated number of SMCs was calculated to evaluate the effect of MSCs seeding on SMCs growth. Flk-1 and vWF protein expressions were observed to analyze the plasticity of the seeded MSCs along endothelial lineage. RESULTS: In this co-culture system, no vWF protein but Flk-1 protein was observed in the 25.71% of MSCs after having been co-cultured with mature rabbit ECs for 5 days. Compared with the control group, the proliferation and migration of SMCs was significantly increased by proliferative ECs but decreased by confluent ECs (n=6, P<0.01). MSCs seeding decreased the proliferation and migration of SMCs compatible with the effect of proliferative ECs (n=6, P<0.001). However, no inhibition on SMCs growth was observed with MSCs seeding in comparison to the effect of confluent ECs. CONCLUSIONS: MSCs seeding can inhibit the proliferation and migration of SMCs. MSCs co-cultured with mature ECs have the ability to undergo milieu-dependent differentiation toward ECs.
The interaction free energy per unit area between parallel flat plates with high surface potential in the case of constant surface potential is again presented. It is complementarity for extended Langmuir method [G. Luo, H. Wang, J. Jin, Langmuir 17 (2001) 2167 and G. Luo, R. Feng, J. Jin, H. Wang, J. Colloid Interface Sci. 241 (2001) 81]. These approximate expressions work quite well for all values of the surface potentials so as the plates separations are small.
OBJECTIVE: To investigate the effects of paclitaxel combined with bone marrow stromal stem cells (MSCs) implantation on inhibiting the smooth muscle cells (SMCs) growth and promoting endothelial repair by developing an endothelial repair model in vitro. METHODS: In a cell coculture system, rabbit endothelial cells (ECs) and human MSCs were seeded in the lower chamber and rabbit SMCs were seeded in the upper chamber. 3H-TdR incorporation and PCNA protein expression were used to evaluate SMCs proliferation at the 10th day after paclitaxel application (1, 10, 100 nmol/L; 20 min). Fluorescence immunocytochemistry was employed to observe the Flk-1 and vWF protein expression on MSCs. RESULTS: The SMCs 3H-TdR incorporation of the MSCs implant group was significantly lower than that of the proliferative ECs group (1 nmol/L: 12 265 +/- 991 vs. 14 505 +/- 1013 cpm/well; 10 nmol/L: 8401 +/- 783 vs. 10 511 +/- 934 cpm/well; 100 nmol/L: 5880 +/- 569 vs. 7457 +/- 768 cpm/well, n = 6, P < 0.05), but higher than that of the confluent ECs group (1 nmol/L: 12 265 +/- 991 vs. 8671 +/- 642 cpm/well; 10 nmol/L: 8401 +/- 783 vs. 6175 +/- 743 cpm/well; 100 nmol/L: 5880 +/- 569 vs. 4423 +/- 406 cpm/well, n = 6, P < 0.05). The expression of SMCs PCNA protein in MSCs implant group was lower than that of the proliferative ECs group (1 nmol/L: 0.92 +/- 0.06 vs. 1.15 +/- 0.07; 10 nmol/L: 0.97 +/- 0.07 vs. 1.07 +/- 0.08; 100 nmol/L: 0.91 +/- 0.05 vs. 1.18 +/- 0.11, n = 6, P < 0.05), but higher than that of the confluent ECs group (1 nmol/L: 0.92 +/- 0.06 vs. 0.74 +/- 0.07; 10 nmol/L: 0.97 +/- 0.07 vs. 0.78 +/- 0.06; 100 nmol/L: 0.91 +/- 0.05 vs. 0.71 +/- 0.05, n = 6, P < 0.05). The MSCs did not express vWF or Flk-1 protein before coculture. Although none cell expressed vWF, some of the MSCs began to express Flk-1 protein after cocultured with mature ECs for 10 days. CONCLUSION: MSCs implantation can partly inhibit the delayed SMCs proliferation. The MSCs cocultured with paclitaxel-treated mature ECs have the ability to differentiate into ECs.
OBJECTIVE: To investigate the correlation between circulating endothelial progenitor cells (EPCs) and the risk factors of coronary heart disease (CHD) as well as the severity of coronary lesions, and its clinical significance. METHODS: 42 patients with CHD and 36 patients excluding CHD (control) were studied. Total mononuclear cells were isolated from peripheral blood by Ficoll density gradient centrifugation, and were cultured in M199 medium supplemented with 20% fetal bovine serum, 50 ng/ml vascular endothelial growth factor (VEGF). After 14 days cultured, the numbers of colony-forming units of EPCs were counted by phase-contrast microscope. The relationship between the number of colony-forming units of EPCs and the risk factors of CHD (such as age, gender, hypertension, hypercholesterolemia, diabetes, smoking, positive family history of CHD) as well as the severity of coronary lesions were assessed. RESULTS: The number of risk factors of CHD was significantly correlated with a reduction of EPCs levels (r = -0.436, P = 0.014). Smoking was associated with significantly lower EPCs levels, whereas a minor but nonsignificant reduction of EPCs levels was detected in the presence of gender, hypertension, and a positive family history of CHD. It was observed that low density lipoprotein (LDL) and uric acid were negatively correlated with the number of colony-forming units of circulating EPCs (P < 0.05). A correlation existed between age, high density lipoprotein, apoprotein A and levels of circulating EPCs, however, this relation was not statistically significant. The number of colony-forming units of circulating EPCs in CHD groups was significantly lower than those in control group (12.8 +/- 6.34 versus 37.0 +/- 5.5, P < 0.001); and the circulating EPCs level of coronary artery lesion group (including single, double, triple vessels disease) was significantly lower than that of control group (P < 0. 01). CONCLUSIONS: The level of circulating EPCs was inversely associated with the risk factor scores of CHD and the severity of coronary artery lesion. These finding imply that endothelial injury in the absence of sufficient circulating EPCs may affect the degree of the heart disorder and the clinical situation.
Endothelial injury, smooth muscle cells (SMCs) proliferation and migration are the same common pathophysiological processes of many cardiovascular diseases, such as atherosclerosis, hypertension, diabetes and restenosis. It is important to determine the functional interactions between endothelial cells (ECs) and SMCs under pathologic conditions. This work was to study the effects of ECs growth states on the proliferation and migration of vascular SMCs in cell coculture system. (3)H-TdR incorporation and flow cytometry were used to determine the effects of ECs growth states on the proliferation of SMCs. The number of migrating SMCs was counted. RT-PCR was used to analyze the expression of alpha-SM-actin mRNA. The results showed that (3)H-TdR incorporation decreased significantly from 14,900+/-1035 cpm/well in the control group to 8,575+/-749 cpm/well in the confluent ECs group (n=6, P<0.01), and increased to 27,268+/-2310 cpm/well in the proliferative ECs group ( n=6, P<0.01). The transition of SMCs from G(0)/G(1) phase to G(2)/M and S phases was blocked in the confluent ECs group but promoted in the proliferative ECs group. Compared with the control group, the number of migrating cells was about 4 times higher in the proliferative ECs group (n=6, P<0.01), while it in the confluent ECs group was only the half of the number of the control(n=6, P<0.05). The expression of alpha-SM-actin mRNA was increased significantly in the confluent ECs group(2.3+/-0.11 vs 1.4+/-0.12, P<0.05), but decreased significantly in the proliferative ECs group(0.92+/-0.08 vs 1.4+/-0.12, P<0.05). The results suggest that the biologic features of SMCs are influenced by ECs growth states. The proliferative ECs promote SMCs proliferation, migration and downregulate alpha-SM-actin mRNA expression significantly.
On the basis of Langmuir's suggestion we simplify the Poisson-Boltzmann equation and derive the relation of surface potential, potential midway, and the plate distance. Thus we obtain the interaction force and energy equations between two dissimilar plates in the case of constant surface charge density. Agreement with the exact numerical values of the interaction of dissimilar plates is good. This method may not only apply to the cases of high constant potential but to the case of high constant charge density.
OBJECTIVE: To establish a method for the determination of zearalenone and its metabolites in grains by capillary electrophoresis. METHODS: The samples were extracted with liquid-liquid partition and ultrasonic extraction, cleaned up with C18 cartridges, then determined by micellar electrokinetic capillary chromatography (MEKC). RESULTS: The limits of detection for Zearalenone (ZON), alpha-Zearalenol (alpha-ZOL), beta-Zearalenol (beta-ZOL), Aflatoxin B1 (AFT B1) and Ochratoxin A (Och A) were 0.0084, 0.081, 0.14, 0.0016 and 0.031 microgram/ml, respectively. Recoveries of all compounds were in the range of 77.9%-103.1%. Relative standard deviations (RSDs) were 0.63%-1.98%. CONCLUSION: This sensitive and accurate method can be used in the determination of zearalenone and its metabolites in grains.
To explore the role of platelet derived growth factor-AA (PDGF-AA) and PDGFR-alpha expression in the proliferation and hypertrophy of vascular smooth muscle cells (VSMCs) in spontaneously hypertension rats (SHR), protein expression of PDGF-AA, PDGFR-alpha and PDGFR-beta in SHR/Wistar-Kyoto (WKY)-VSMC was observed by Western blot. Proliferation and hypertrophy of SHR-VSMCs induced by PDGF-AA were observed by measurement of PCNA and [(3)H] incorporation. PDGF-AA and PDGFR-alpha expression was markedly increased in SHR-VSMCs compared with that in WKY-VSMCs, but PDGFR-beta was not different in SHR and WKY-VSMCs. PDGF-AA induced PCNA expression and [(3)H] incorporation was increased in a dose-dependent manner in SHR, but not in WKY. It is suggested that an enhancement of PDGF-AA and PDGFR-alpha in SHRs may be one of the important factors for vascular modeling.