Biomedical subjects

Yan Jin

Publications and source records attributed to Yan Jin.

At least 73 records · Page 4Linked to original sources

PubMed2005

Effects of transforming growth factor beta1 (TGFbeta-1) and dentin non-collagenous proteins (DNCP) on human embryonic ectomesenchymal cells in a three-dimensional culture system.

Cranial neural crest-derived ectomesenchymal cells represent a population of pluripotent stem cells giving rise to many of the various oro-facial and dental tissues. The factors determining the terminal fate of these cells are still unclear. The potentiality of human embryonic ectomesenchymal cells from the first branchial arch have been investigated when isolated and grown in a three-dimensional (3D)-collagen gel culture system in the presence of dentin matrix-derived non-collagenous proteins (DNCP) and TGFbeta-1. Functional differentiation of cells showing some characteristics of odontoblast-like cells could be observed when the cells were cultured with DNCP+TGFbeta-1 or DNCP, however, only cytological differentiation was observed during culture with TGFbeta-1 alone. The characteristics of these cells was assessed by morphological appearance, expression of the odontoblast phenotype marker dentin sialophosphoprotein (DSPP), increased alkaline phosphatase levels and formation of mineralised nodules in vitro. The results indicate that these embryonic cells from the first branchial arch are capable of responding to the inductive stimulus of DNCP or DNCP+TGFbeta-1 when isolated and grown in the 3D collagen gel culture system. The capacity of the isolated cells to differentiate into mineralizing cells showing some characteristics of odontoblast-like cells under these growth conditions highlights the potential of such approaches for tissue engineering strategies for hard-tissue regeneration after injury.

Alkaline Phosphatase↗

PubMed2005

Neurotoxic effects of trypan blue on rat retinal ganglion cells.

To facilitate the peeling of internal limiting membrane or epiretinal membrane in vitreoretinal surgery, trypan blue (TB) and indocyanine green (ICG) have been used. However, the cytotoxicity of these dyes have been concerned. The aim of this study was to investigate the neurotoxic effects of TB on rat retinal ganglion cells (RGCs) and compare the effect of TB with ICG. Rat RGCs were purified by a two-step immunopanning procedure. In short-time exposure experiments, purified RGCs cultured for 3 days were exposed to 600 mgL(-1) TB, 1500 mgL(-1) TB and 1500 mgL(-1) ICG for 10 sec to 30 min. The number of viable RGCs was counted after 12 hr in culture. In long-time exposure experiments, purified RGCs were cultured for 3 days in TB solutions ranging from 2 to 800 mgL(-1) or in ICG solutions at concentrations from 2 to 250 mgL(-1). Then the number of viable cells was counted. Exposure to 600 mgL(-1) TB, 1500 mgL(-1) TB and 1500 mgL(-1) ICG for short time from 10 sec to 30 min caused a time-dependent damage to RGCs. There was no significant difference in cytotoxicity to RGCs between TB and ICG in short-time exposure. In long-time exposure, TB as well as ICG showed neurotoxic effect on RGCs in a dose-dependent manner. Fifty percentage inhibitory concentration (IC50) of TB to RGCs was calculated as 115 mgL(-1), while that of ICG was 33 mgL(-1). In conclusion, TB induced neurotoxic effect on RGCs in a dose- and time-dependent manner. During the short-time exposure in surgery, there is likely no difference in neurotoxic effect on RGCs between TB and ICG. However, once the dyes are left in the eyes after surgery, TB may show less toxicity on RGCs than ICG.

Animals↗

PubMed2005

Differential regulation of survivin by p53 contributes to cell cycle dependent apoptosis.

Recent studies indicate that cell-cycle checkpoints are tightly correlated with the regulation of apoptosis, in which p53 plays an important role. Our present works show that the expression of E6/E7 oncogenes of human papillomavirus in HeLa cells is inhibited in the presence of anti-tumor reagent tripchlorolide (TC), which results in the up-regulation of p53 in HeLa cells. Interestingly, under the same TC-treatment, the cells at the early S-phase are more susceptible to apoptosis than those at the middle S-phase although p53 protein is stabilized to the same level in both situations. Significant difference is exhibited between the two specified expression profiles. Further analysis demonstrates that anti-apoptotic gene survivin is up-regulated by p53 in the TC-treated middle-S cells, whereas it is down-regulated by p53 in the TC-treated early-S cells. Taken together, the present study indicates that the differential p53-regulated expression of survivin at different stages of the cell cycle results in different cellular outputs under the same apoptosis-inducer.

Animals↗

PubMed2005

p53-independent pRB degradation contributes to a drug-induced apoptosis in AGS cells.

The retinoblastoma (RB) tumor suppressor protein, pRB, plays an important role in the regulation of mammalian cell cycle. Furthermore, several lines of evidence suggest that pRB also involves in the regulation of apoptosis. In the present study, the degradation of pRB was observed in apoptotic gastric tumor cells treated with a new potent anti-tumor component, tripchlorolide (TC). The inhibition of pRB degradation by a general cysteine protease inhibitor IDAM resulted in the reduction of the apoptotic cells. Furthermore, the survival of the gastric tumor cells under the TC treatment was enhanced by an over-expression of exogenous pRB. These results suggest that the pRB degradation of the gastric tumor cells under the TC treatment involves in the apoptotic progression. In addition, the same extent of TC-induced pRB-degradation was detected in the gastric tumor cells containing a p53 dominant-negative construct, indicating that this kind of pRB degradation is p53-independent.

Apoptosis↗

PubMed2005

Preparation of recombinant human bone morphogenetic protein-2 loaded dextran-based microspheres and their characteristics.

AIM: To prepare new pharmaceutical forms with sustained delivery properties of recombinant human bone morphogenetic protein-2 (rhBMP2) for tissue engineering and guided tissue regeneration (GTR) use. METHODS: rhBMP2-loaded dextran-based hydrogel microspheres (rhBMP2-MPs), which aimed to keep rhBMP2 bioactivity and to achieve long-term sustained release of rhBMP2, were prepared by double-phase emulsified condensation polymerization. The physical, chemical performances and biological characteristics of those microspheres were studied both in vitro and in vivo. RESULTS: The microspheres' average diameter was 30.33+/-4.32 microm with 75.4% ranging from 20 microm to 40 microm and the drug loading and encapsulation efficiency were 7.82% and 82.25%, respectively. The rhBMP2-releasing profiles in vitro showed that rhBMP2 release could be maintained more than 10 d. The rhBMP2-MPs, with good swelling and biodegradation behavior, could be kept for 6 months at below 4 degree without significant characteristic change or bioactivity loss. Cytology studies showed that rhBMP2-MPs could promote the proliferation of periodontal ligament cells (PDLCs) approximately 10 d, while the bioactivity of concentrated rhBMP2 solution could keep no more than 3 d. Scanning electron microscope showed that rhBMP2-MPs could be enchased into the porous structure of calcium phosphate ceremic (CPC) and the eugonic growth of PDLCs in CPC/rhBMP2-MPs scaffolds. Animal experiments indicated that using CPC/rhBMP2-MPs scaffolds could gain more periodontal tissue regeneration than using rhBMP2 compound firsthand with CPC (CPC/rhBMP2). CONCLUSION: By encapsulating rhBMP2 into dextran-based microspheres, a small quantity of rhBMP2 could achieve equivalent effects to the concentrated rhBMP2 solution and at the same time, could prolong rhBMP2 retention both in vitro and in vivo.

Animals↗

PubMed2005

Effects of shark hepatic stimulator substance on the function and antioxidant capacity of liver mitochondria in an animal model of acute liver injury.

This study was carried out to investigate whether shark hepatic stimulator substance (HSS) can prevent acute liver injury and affect mitochondrial function and antioxidant defenses in a rat model of thioacetamide (TAA)-induced liver injury. The acute liver injury was induced by two intraperitoneal injections of TAA (400 mg/kg) in a 24 h interval. In the TAA plus shark HSS group, rats were treated with shark HSS (80 mg/kg) 1 h prior to each TAA injection. In this group, serum liver enzyme activities were significantly lower than those in the TAA group. The mitochondrial respiratory control ratio was improved, and the mitochondrial respiratory enzyme activities were increased in the TAA plus shark HSS group. The mitochondrial antioxidant enzyme activities and glutathione level were higher in the TAA plus shark HSS group than in the TAA group. These results suggest that the protective effect of shark HSS against TAA-induced acute liver injury may be a result of the restoration of the mitochondrial respiratory function and antioxidant defenses and decreased oxygen stress.

Animals↗

PubMed2005

Mineralocorticoids decrease the activity of the apical small-conductance K channel in the cortical collecting duct.

We used the patch-clamp technique to examine the effect of DOCA treatment (2 mg/kg) on the apical small-conductance K (SK) channels, epithelial Na channels (ENaC), and the basolateral 18-pS K channels in the cortical collecting duct (CCD). Treatment of rats with DOCA for 6 days significantly decreased the plasma K from 3.8 to 3.1 meq and reduced the activity of the SK channel, defined as NP(o), from 1.3 in the CCD of control rats to 0.6. In contrast, DOCA treatment significantly increased ENaC activity from 0.01 to 0.53 and the basolateral 18-pS K channel activity from 0.67 to 1.63. Moreover, Western blot analysis revealed that DOCA treatment significantly increased the expression of the nonreceptor type of protein tyrosine kinase (PTK), cSrc, and the tyrosine phosphorylation of ROMK in the renal cortex and outer medulla. The possibility that decreases in apical SK channel activity induced by DOCA treatment were the result of stimulation of PTK activity was further supported by experiments in which inhibition of PTK with herbimycin A significantly increased NP(o) from 0.6 to 2.1 in the CCD from rats receiving DOCA. Also, when rats were fed a high-K (10%) diet, DOCA treatment did not increase the expression of c-Src and decrease the activity of the SK channel in the CCD. We conclude that DOCA treatment decreased the apical SK channel activity in rats on a normal-K diet and that an increase in PTK expression may be responsible for decreased channel activity in the CCD from DOCA-treated rats.

Animal Feed↗

PubMed2005

ICU management of patients with suspected positive findings of diagnostic peritoneal lavage following blunt abdominal trauma.

OBJECTIVE: To explore the management for blunt abdominal trauma victims with probable positive diagnostic peritoneal lavage (DPL) findings. METHODS: Data of 76 patients with probable positive DPL findings accepted to ICU in previous 10 years were reviewed. After admission, the patients were evaluated in a settled time according to the protocols of Advanced Trauma Life Support (ATLS). Vital signs were continuously monitored and DPL, ultrasound and/or CT scan were repeated when necessary. RESULTS: Eighteen (24%) of 76 patients presented positive DPL findings after repeated DPL. Surgical findings confirmed 7 cases of spleen rupture, 3 hepatorrhexis (infra-Glisson capsule), 4 intestinal perforation, 2 gastric perforation, 1 colon perforation and 1 injured mesentery. CONCLUSIONS: Patients with probable positive DPL findings were admitted to ICU with vital signs continuously monitored. Repeated DPL with supplemental ultrasound and/or CT scan can work together to increase the sensitivity and accuracy of the diagnosis, reduce the rate of exploratory laparotomy, ensure patients' safety and provide a reliable basis for therapeutic operations.

Abdominal Injuries↗

PubMed2005

[Clinical observation on treatment of non-gonococcal cervicitis by integrative medicine].

OBJECTIVE: To explore the integrative medicinal therapy for non-gonococcal cervicitis (NGC) in order to elevate the therapeutic effect for patients treated in vain after long-term application of antibiotics. METHODS: Fifty patients with NGC were treated with Qingyuan decoction combined with antibiotics, and other 46 patients were treated with antibiotics alone for control. RESULTS: The cure rate and significant effective rate was 90.0% (45/50) and 65.2% (30/46) in the treated group and the control group, it was significantly different between the two groups (chi2 = 9.58, P < 0.01). The disappearance rate of symptom was 88.1% and 41.4% in the two group after treated for two weeks respectively, and it was also significantly different (chi2 = 12.42, P < 0.01). CONCLUSIONS: The therapeutic effect of NGC treated by sensitive antibiotics combined with Qingyuan decoction is better than that treated with western medicine only.

Adult↗

PubMed2005

[Culture of human epidermal stem cells in different media and their biological characteristics].

OBJECTIVE: To select the appropriate media to culture the epidermal stem cells in vitro, and to observe the biological characteristics of the epidermal stem cells. METHODS: The epidermal stem cells were cultured in five different media, including FAD, FAD+1 ng/ml bFGF, FAD+5 ng/ml bFGF, FAD+10 ng/ml bFGF and K-SFM, and the same fetus fibroblasts were used as the nutrient cells. The proliferation ability was investigated by cell growth curve and MTT detection. Then the biological characteristics of epidermal stem cells were observed through phase-contrast microscope, cell growth curve, BrdU detection and FBM analysis. RESULTS: The epidermal stem cells grew best in FAD with bFGF and nutrient cells. And the epidermal stem cells retained proliferative capacity, and formed larger and more expandable clones in vitro. And 80.2% of the cells show a G0/G1 cycle, and the cells had long cell proliferation cycle. CONCLUSION: The above results demonstrate that the media with bFGF and the use of nutrient layer were appropriate to culture epidermal stem cell in vitro. And the epidermal stem cells have a slow cell cycle, characteristics of immaturity.

Cell Adhesion↗

PubMed2005

[Expression of mineral-associated markers in human dental follicle cells in vitro].

OBJECTIVE: To culture human dental follicle cells in vitro and observe their mineralization characteristics. METHODS: Human dental follicle tissues were digested with bacterial collagenase and cultured to obtain dental follicle cells. Mineralization characteristics of these cells were identified by immunohistochemistry and reverse transcription (RT)-PCR. Dental follicle cells were incubated with mineralization-inducing agents to observe the formation of mineralized nodules. RESULTS: Immunohistochemistry staining revealed expressions of type I collagen, type III collagen, osteopontin and osteonectin in the cytoplasm of dental follicle cells cultured in vitro. Low levels of bone sialoprotein, osteocalcin and alkaline phosphatase mRNA were also detected by RT-PCR. Mineralized nodules were observed after 20 days of incubation with mineralization-inducing agents with positivity for von-Kossa staining. CONCLUSION: Human dental follicle cells cultured in vitro show some features of osteoblasts or cementoblasts and can be used as the seed cells for periodontal tissue engineering.

Calcification, Physiologic↗

PubMed2005

[13q14 aberration is related to the metastatic potential of human NSCLC].

A large number of numerical and structural aberrations were analyzed in human tumor metastatic cells and 13q14 aberrations were frequently detected in some types of metastatic cancers. The rearrangement of 13q14 was identified previously in two lung adenocarcinoma cell lines with the same origin but different metastatic potential AGZY83-a and Anip973. BRI gene showed different expression levels in the cell lines as revealed by mRNA differential display (mRNA DD) in the two cell lines, and located in 13q14. In order to investigate the relationship between 13q14 abnormalities and tumor metastasis, a painting probe (13q) was used to hybridize three G-banded NSCLC cell lines with different metastatic potential. The major abnormality of 13q differs among different cell lines, including 13q32-33 frequent breakpoint in these three cell lines. But low metastatic potential cell lines PAa, SPC-1-A were not found breakpoint in 13q14, while 95D cell line with high metastatic potential had the common breakpoint 13q14 in two cell clones. The results suggested that the breakage at 13q14 may possibly be related to lung cancer metastasis. The affirmative relationship between 13q14 aberration and NSCLC needs further investigation.

Carcinoma, Non-Small-Cell Lung↗

PubMed2005

Cloning of full-length cDNA sequence of a novel candidate gene related to mouse cleft palate.

OBJECTIVE: Cloning and screening a novel candidate gene related to developing mouse cleft palate. METHODS: The differentially expressed genes were cloned by modified PCR-based subtractive hybridization. After identification using reverse dot blotting, positive clones were sequenced and analyzed for homology in GenBank databases. RESULTS: Four novel express sequence tags were obtained, one of which spanning 809 bp was the full-length of the novel gene cDNA identified by Northern hybridization. CONCLUSION: A novel candidate gene related to mouse cleft palate was cloned.

Adaptor Proteins, Signal Transducing↗

PubMed2005

[Tissue engineering of dentin-pulp complex-like structures by human dental mesenchymal cells].

OBJECTIVE: To establish three-dimensional culture model of human dental mesenchymal cells and bioengineer in vivo with ceramic bovine bone (CBB) and Collagraft as scaffolds. METHODS: Human dental mesenchymal cells induced upon stimulation of bFGF and IGF-1 or TGF-beta(1) were implanted onto CBB and Collagraft containing the same kinds of growth factors respectively. Then cell/scaffold constructs were transplanted into nude mice to establish in vivo culture model of dental mesenchymal cells. Control groups were set up at the same time. After 4 weeks or 10 weeks, the implants were taken out for histological and immunohistochemical analysis. RESULTS: Within 10-week implant tissues, typical dentin-pulp complex-like structures were generated in scaffolds containing growth factors. Human dentin sialoprotein (DSP) was expressed in the newly formed dentin. This phenomenon wasn't observed in control groups and 4-week implants. CONCLUSIONS: Dentin-pulp complex-like structures could be bioengineered successfully with human dental mesenchymal cells and CBB or Collagrafts containing growth factors in nude mice.

Animals↗

PubMed2005

[Preparation and property of recombinant human bone morphogenetic protein-2 loaded hydrogel nanospheres and their biological effects on the proliferation and differentiation of bone mesenchymal stem cells].

PURPOSE: To prepare and study the recombinant human bone morphogenetic protein-2 loaded dextran-based hydrogel nanospheres (rhBMP(2)-dex-NPs) sustained release system, and to evaluate its biological effects on cultured rabbit bone mesenchymal stem cells(BMSCs). METHODS: The rhBMP(2)-dex-NPs were prepared by improved emulsion polymerization method. Their morphology, size and size distribution, encapsulated ratio and stability were assessed by routine procedure. Dynamic dialysis method was used to determine the release characteristics of rhBMP(2)-dex-NPs in vitro. Cell culture technique and MTT colorimetric assay were used to evaluate the proliferation and differentiation of the BMSCs, ALP kit was used to evaluate the ALP activity of the BMSCs so as to show the differentiation of the cells by adding the rhBMP(2)-dex-NPs to the DMEM culture medium (B group) or rhBMP2 only (A group). Adding dex-NPs without rhBMP2 (C group) and adding nothing (D group) were taken as the controls. The results were analyzed by statistical analysis software (SPSS10.0). RESULTS: The shape of rhBMP(2)-dex-NPs was spherical, with a size distribution of 20 nm. The encapsulated ratio was 83% and rhBMP(2)-dex-NPs could be kept more than 6 months under 4 degrees C without decomposition , destruction or deposition. The release profile in vitro was in accordance with two phases kinetics law, and more than 80% of the encapsulated rhBMP(2) can be released during 12 days. Statistical analysis showed that rhBMP(2)-dex-NPs had biological activity, and could enhance both proliferation and differentiation of rabbit BMSCs significantly, the effect of the rhBMP(2)-dex-NPs was significantly higher than that of rhBMP(2) (P<0.01). During the first 3 days, the proliferation and differentiation of BMSCs between group A and B had no significance (P>0.05), but much faster than group C and D. After 5 to 7 days, rhBMP(2)-dex-NPs could enhance BMSCs proliferation and differentiation continually, but rhBMP2 had no enhancement any more. 7 days later, the difference between group A and B become much more significant (P<0.001). CONCLUSIONS: The rhBMP(2)-dex-NPs can release rhBMP2 more than 12 days and have long-drawn biological effects. To encapsulate rhBMP2 into dextran-based hydrogel nanospheres may be an effective way of growth factor controlled release in tissue engineering.

Animals↗

PubMed2005

A pilot-scale jet bubbling reactor for wet flue gas desulfurization with pyrolusite.

MnO2 in pyrolusite can react with SO2 in flue gas and obtain by-product MnSO4 x H2O. A pilot scale jet bubbling reactor was applied in this work. Different factors affecting both SO2 absorption efficiency and Mn2+ extraction rate have been investigated, these factors include temperature of inlet gas flue, ration of liquid/solid mass flow rate (L/S), pyrolusite grade, and SO2 concentration in the inlet flue gas. In the meantime, the procedure of purification of absorption liquid was also discussed. Experiment results indicated that the increase of temperature from 30 to 70 K caused the increase of SO2 absorption efficiency from 81.4% to 91.2%. And when SO2 concentration in the inlet flue gas increased from 500 to 3000 ppm, SO2 absorption efficiency and Mn2+ extraction rate decreased from 98.1% to 82.2% and from 82.8% to 61.7%, respectively. The content of MnO2 in pyrolusite had a neglectable effect on SO2 absorption efficiency. Low L/S was good for both removal of SO2 and Mn2+ extraction. The absorption liquid was filtrated and purified to remove Si, Mg, Ca, Fe, Al and heavy metals, last product MnSO4 x H2O was obtained which quality could reach China GB1622-86, the industry grade standards.

Absorption↗

PubMed2005

[Genomic analysis of a familial clustering of chronic hepatitis B patients].

OBJECTIVE: To investigate the peripheral blood monocyte (PBMC) gene expression profile in a familial clustering of patients with chronic hepatitis B (CHB). METHODS: cRNA prepared from PBMC in a family with 5 CHB patients and 4 normal controls was hybridized to high-density oligouncleotide arrays (HG-U133A 2.0 Human GeneChips, Affymetrix), which interrogate the expression of approximately 22,000 human ESTs. Primary image obtained from scanning was analysed with a DNT software package. Real-time PCR was employed to confirm the gene chip results. RESULTS: 55 genes out of 22,000 ESTs were identified differently. Among the 55 genes 14 showed increased expression and 41 showed decreased expression in the familial clustering CHB patients compared with those in normal controls. Most of the genes (57%) were involved in immunity, inflammation, apoptosis, signaling transduction, and cell cycle. CONCLUSION: These results suggest that the hosts with this broad range of gene expression alterations are susceptible to hepatic B infection.

Cluster Analysis↗

PubMed2005

[Study on biological effect of transforming growth factor B and recombinant human bone morphogenetic protein 2 on the Schwann cell].

OBJECTIVE: To study biological effect of transforming growth factor beta (TGF-beta) and recombinant human bone morphogenetic protein 2 (rhBMP-2) on the Schwann cell (SC) in vitro. METHODS: Cultured SC from newborn SD rats were implanted at 5 x 10(3)/well in 96-well-plate (36 wells in each group, altogether 3 groups): TGF-beta group (group A) treated with 50 ng/ml TGF-beta; rhBMP-2 group (group B) treated with 50 ng/ml rhBMP-2 and control group (group C). SC proliferation activity was assessed by MTT and flow cytometry (FCM) methods, and nerve growth factor (NGF) synthesis in SC culture media was detected by ELISA method. RESULTS: MTT observation indicated that there was significant difference in the growth curve among 3 groups until the 8th and 9th day. Group A had more obvious rising tendency than group B and group C. FCM observation indicated that the proliferation index of group A and group B was higher than that of group C(P<0.05). ELISA observation indicated that there was significant difference in the NGF concentration of the culture medium among the 3 groups (P<0.05). Group A had the highest NGF concentration. CONCLUSION: Exogenous TGF-beta and rhBMP-2 can promote SC's ability to proliferate NGF, but TGF-beta is more effective than rhBMP-2.

Animals↗