Biomedical subjects

Yan Jin

Publications and source records attributed to Yan Jin.

At least 127 records · Page 7Linked to original sources

PubMed2003

[Histological study of the dental implant-bone interface remodeling of submerged and nonsubmerged implants in dogs].

OBJECTIVE: To compare the characteristics of histological reaction at the implant-bone interface after submerged and nonsubmerged implant remodeling in dogs. METHODS: Eight adult mongrel dogs were used to establish the animal model for submerged and nonsubmerged implants into the bilateral mandibular sites. At 1, 2, 4, and 12 weeks postoperatively, 2 dogs were sacrificed at each time point for histological observation of the healing and remodeling process at the implant-bone interface by HE staining. RESULTS: No distinct difference in the rate of new bone generation and degree of osseointegration was observed between dogs with submerged and nonsubmerged implant at each time point. CONCLUSION: In spite of the bite force imposed on the abutment to some extent during the healing process after nonsubmerged implant plantation, favorable osseointegration similar to that after submerged implants can be achieved.

Animals↗

PubMed2003

Expression and localization of Smad1, Smad2 and Smad4 proteins in rat testis during postnatal development.

AIM: To study the expression and regulation of Smad1, Smad2 and Smad4 proteins (intracellular signaling molecules of transforming growth factor-b family) in rat testis during postnatal development. METHODS: The whole testes were collected from SD rats aged 3, 7, 14, 28 and 90 (adult) days. The cellular localization and developmental changes were examined by immunohistochemistry ABC method with the glucose oxidase-DAB-nickel enhancement technique. Quantitative analysis of the immunostaining was made by the image analysis system. The Smads proteins coexistence in the adult rat testis was tested by the double immune staining for CD14-Smad4 and Smad2-Smad4. The protein expression of Smad during rat testicular development was examined by means of Western blots. RESULTS: Smad1, Smad2 and Smad4 were present throughout testicular development. The immunostaining of Smad1 and Smad2 were present in spermatogenic cells. A positive immunoreactivity was located at the cytoplasm, but the nucleus was negative. Smad1 was immunolocalized at the d14, d28 and adult testes, while Smad2, at the d7, d14, d28 and adult testis. There was positive immunoreaction in the Sertoli cells and Leydig cells as well. The immunolocalization of Smad4 was exclusively at the cytoplasm of Leydig cells and the nuclei were negative throughout the testicular development. No expression was detected in the germ cells. The results of image and statistical analysis showed that generally the expression of Smad1, Smad2 and Smad4 in the testis tended to increase gradually with the growth of the rat. CONCLUSION: The present data provide direct evidences for the molecular mechanism of TGF-bgr action in rat testes during postnatal development and spermatogenesis.

Animals↗

PubMed2003

[Expression of basic fibroblast growth factor and fibronectin in tissue engineering skin allograft during healing process].

OBJECTIVE: The aim of this study was to explore the expression of basic fibroblast growth factor (bFGF) and fibronectin during the healing process of allograft tissue engineering skin. METHODS: The tissue engineering skin that was obtained from neonatal SD rats was cultured in the lab. Afterwards, the skin was grafted into adult SD rats, and the expressions of bFGF and fibronectin were detected on the 7th, 10th, 14th, 20th and 30th day after the allograft of the tissue engineering skin. The autografted skin in 15 adult Wistar rats and the normal skin in 15 Wistar were treated as the control. HE staining and immunohistochemical staining were used to examine the healing of grafted skin. RESULTS: The expression of bFGF and fibronectin was the strongest on the 10th day after graft, and was weaker before the 10th day and after the 14th day. The expression changes of bFGF and fibronectin were similar as they were in the autograft group. CONCLUSION: The expression changes of bFGF and fibronectin in the tissue engineering skin during the process of wound healing were similar to those of autografted skin, and these can promote the repair of tissue engineering skin allograft.

Animals↗

PubMed2003

[Expression of CNTFs in facial motoneurons during facial nerve regeneration in rats and their association with TGF-beta and rhBMP-2].

OBJECTIVE: The aim of this study was to observe the expression of ciliary neurotrophic factors (CNTFs) in the facial motor neurons in rats during facial nerve regeneration. METHODS: The expression amount of CNTFs in eight groups was determined with immunohistochemical staining and image analysis. RESULTS: The expression of CNTFs increased during the process of nerve regeneration, and reached the maximum one-week and one-month after nerve injury respectively. After one month, the intensity of CNTFs reduced gradually. The expression of recombinant human bone morphogenetic protein-2 (rhBMP-2) did not show distinct difference comparing with the control, but beta transforming growth factors (TGF-beta) benefited the expression of CNTFs during nerve regeneration. CONCLUSION: The endogenous CNTFs promotes the axon outgrow during regeneration, and TGF-beta promotes the expression of CNTFs to rescue motoneuron during facial nerve regeneration.

Animals↗

PubMed2003

[Overexpression of p21WAF1 and p53 in human lung adenocarcinoma cell line].

OBJECTIVE: To study the growth inhibitory effects of p21WAF1 and p53 overexpression in human lung adenocarcinoma cell line. METHODS: The p21WAF1 and p53 gene were transfected respectively into a human lung adenocarcinoma cell line, GLC-82. Flow cytometry (FLC), transmission electron microscopy (EM) and TUNEL technique were used to evaluate cell growth and identify apoptosis. RESULTS: The GLC-82 transfected by p21 plasmid showed increased cell number in G1 phase of cell cycle, decreased proliferation potential and decreased cloning efficiency. Apoptosis have not been detected neither on EM nor by TUNEL technique, whereas the GLC-82 infected by Ad-p53 showed significantly decreased proliferation potential and some of them even died, in addition apoptosis was confirmed by TUNEL technique. CONCLUSION: The results indicate that p21WAF1 and p53 can inhibit proliferation; p53 also can induce apoptosis of lung adenocarcinoma cell. Therefore, these two genes should have a wide application in gene therapy of tumors in future.

Adenocarcinoma↗

PubMed2003

[Effect of compound pattern of ceramic bovine bone and hydrogel on attachment and growth of bone marrow stomal cell].

OBJECTIVE: To investigate the effect of compound pattern of ceramic bovine bone (CBB) and hydrogel(HG) on attachment, proliferation and differentiation of bone marrow stromal cell (MSC), and to find out the best way of constructing tissue engineered bone. METHODS: CBB, HG and MSC was compounded in different patterns and sequences to form CBB/HG/MSC (group A), HG/MSC/CBB (group B), CBB/MSC/HA (group C) and CBB/MSC (control group). Attachment and morphology of MSC were observed by scanning electronic microscope; the proliferation of MSC was evaluated by cell count; alkaline phosphatase(ALP) activity was examined by histochemistry and type I collagen synthesis was examined by immunohistochemistry staining 5 and 10 days later. RESULTS: In group A, MSC spread better, and ALP activity of group A was significantly higher than that of group B and control group(P < 0.01); but there was no significant difference between group A and group C(P > 0.05). There was no significant difference in type I collagen synthesis between four groups on the 5th day; but mean gray scale of type I collagen in group B was significantly higher than that in the other groups on the 10th day(P < 0.01). CONCLUSION: Different compound patterns of CBB, HG and MSC affect attachment, proliferation, differentiation of MSC. The compound pattern of CBB/HG/MSC is better than the others.

Animals↗

PubMed2003

[Selection and identification of human keratinocyte stem cells in vitro].

OBJECTIVE: To investigate the selection and identification of human keratinocyte stem cells(KSC) in vitro. METHODS: According to the characteristics of KSC which can adhere to extracellular matrix very fast, we selected 3 groups of different time(5 minutes, 20 minutes and 60 minutes) and unselected as control group. And the cells were identified by monoclone antibody of beta 1-integrin and cytokeratin 19 (Ck19), then the image analysis was done. Furthermore we analyzed the cultured cells with flow cytometer(FCM) and observed the ultrastructure of the cell by transmission electron microscope(TEM). RESULTS: The cell clones formed in all groups after 10 to 14 days, while the cells of 5 minute group grew more slowly than those of the other groups, however, the clones of this group were bigger. The expression of beta 1-integrin and Ck19 were found in all groups. The positive rate of beta 1-integrin was significant difference between 5 minute group and the other groups (P < 0.05). And the expression of Ck19 was no significant difference between 5 minute group and 20 minute group(P > 0.05), and between 60 minute group and control group. But significant difference was observed between the former and the later groups(P < 0.05). The result of FCM showed that most cells of the 5 minute group lied in G1 period of cell cycle, which was different from those of the other groups. At the same time, the cells of 5 minute group were smaller and contained fewer organelles than those of the other groups. CONCLUSION: The above results demonstrate that the cells of 5 minute group have a slow cell cycle, characteristics of immaturity, and behaving like clonogenic cells in vitro. The cells have the general anticipated properties for KSC. So the KSC can be selected by rapid attachment to extracellular matrix and identified by monoclone antibody of beta 1-integrin and Ck19.

Antibodies, Monoclonal↗

PubMed2003

[Identification of ectomesenchymal stem cells of human fetal facial processes and spontaneous differentiation to smooth muscle cells].

OBJECTIVE: To investigate the characteristic and phenotype of ectomesenchymal stem cells of human fetal facial processes and the procedure of spontaneous differentiation to smooth muscle cells. METHODS: The primary ectomesenchymal cells of E 50 human fetal facial processes were isolated by 2.5 g/L trypsin and cultured with DMEM/F 12 with 10(-6) U/L leukemia inhibitor factor(LIF). The morphology and growth rate were observed by inverted microscop. After being withdrawn LIF, the characteristic of cells were identified by immunohistochemistry and RT-PCR. Ultrastructure was observed by transmission electron microscope. RESULTS: The cultured cells displayed monolayer growth and were fibroblast-like with 2-4 processes. The cells were stainely positived for anti-human natural killer cell marker-1, Vimentin, S-100, neuron specific enolase, myoglobin and VIII factor, but negatively for glial fibrillary acidic protein, neural fiblament, alpha-SMA and cytokeratin in immunohistochemistry. Two days after being withdrawn the LIF, cells expressed alpha-SMA in protein and mRNA levels. The cells were rich in muscular filament-like structure and dense bodies under transmission electron microscope. CONCLUSION: Cultured cells are undifferentiated ectomesenchymal stem cells. The cells have the potential for differentiating spontaneously to smooth muscle cell.

Actins↗

PubMed2003

[Research on expression and control of p16 and p21 by wild-type p53 gene in two lung adenocarcinoma cell lines].

OBJECTIVE: To evaluate the potential of p53 gene therapy for lung cancer in nude mice. METHODS: Two lung adenocarcinoma cell lines L-18 and 95D were infected with adenovirus encoding wild-type p53 gene pAdCMV -p53 (Ad-p53 ) in vitro and in vivo. The antitumor effect of wild type p53 gene was assessed by cell growth curve, reverse transcriptase polymerase chain reaction (RT-PCR) analysis and TUNEL staining methods. RESULTS: The p53-specific growth inhibition and apoptosis of tumor cells were observed in both cell lines in vitro. By RT-PCR analysis, the increasing expression of p21 gene but not of p16 gene after p53 gene infection suggested that p21 gene played an important role in p53 gene induced cell apoptosis. The in vivo study revealed that celiac injection of p53 gene significantly inhibited the tumorigenesis in 95D and L-18 cells in nude mice. However, no obvious inhibition of tumorigenesis was observed after subcutaneous injection of p53 gene in L-18 cell line, compared with the inhibition noted in 95D cell line. CONCLUSION: The results showed the adenovirus-mediated antitumor therapy by means of p53 gene infection might be a potential way to inhibit cancer growth and induce tumor cell apoptosis.

Adenocarcinoma↗

PubMed2003

[Studies of TGF-beta/Smads expression in lung cancer].

Smad proteins transduce signals from transforming growth factor beta superfamily ligands that regulate cell proliferation, differentiation and death through activation of receptor serine/threonine kinases. TGF-beta/Smads signal pathway not only has transforming potential but can also drive tumourigenesis, malignant progression, invasion and metastasis of human cancers. Using the immuno-histochemistry, we investigate the expression and location of TGF-beta R II, Smad2, Smad4 and Smad7 in 20 lung cancer specimens and 8 lung cancer cell lines. The results suggest that aberrant smads protein expression is significantly related to lung cancer tumoruigenesis and progression. Interestingly, TGF-beta R II and Smad7 strongly express in high metastasis cell lines. High expression of TGF-beta R II and smad7 in the cell lines with high-metastatic potential showed a conceivable TGF-beta signal pathway independent Smads in the lung cancer, and that might mediate invasion and metastasis of lung cancer.

DNA-Binding Proteins↗

PubMed2003

Spontaneous diuresis and negative fluid balance predicting recovery and survival in patients with trauma-hemorragic shock.

Most patients with trauma-hemorragic shock, prior to ICU admission, have been resuscitated and stabilized in the emergency room (ER) and/or operation room (OR). Many of them suffer from systemic edema. This extra-vascular fluid is caused by massive infusion of fluid and blood for the maintenance of blood pressure. During the recovery stage, the patients exhibit spontaneous diuresis followed by negative fluid balance. Urine volumes of some patients are more than 10000 ml/d. Do we need to maintain a balance between daily input and output of water at this situation? There are many references in the medical literature and textbooks about fluid resuscitation and the principles in maintaining the balance between input and output of water, but rarely about when and how to restrict it, that is, when and how to permit a negative balance. In this retrospective review, we examined the resuscitation records of 205 patients with systemic edema after trauma-hemorragic shock.

Adolescent↗

PubMed2003

[Construction of tissue engineering skin containing melanocytes].

OBJECTIVE: To construct a tissue engineering skin containing melanocytes by employing tissue engineering method. METHODS: The keratinocytes, dermal fibroblasts and melanocytes were isolated and purified. Then the cells were used to construct a tissue engineering skin containing melanocytes. The location of melanocytes in the tissue engineering skin were detected by Dopa staining, transmission electron microscope (TEM) and S-100 immunohistochemical staining. RESULTS: Melanocytes can be detected in the basal layer of the constructed tissue engineering skin. The results of TEM showed that the melanocytes were in good conditions. CONCLUSION: The artificial skin containing melanocytes was successfully constructed in vitro and can be used to repair the full-thickness skin defects.

Adolescent↗

PubMed2003

[Study on tumor necrosis factor-alpha and interleukin 2 in rat skin allograft].

OBJECTIVE: To elucidate the histocompatibility of tissue engineered rat skin through studying the effect of TNF-alpha and IL-2 in immunological rejection after rat skin allograft. METHODS: Tissue engineered skin that the basic materials were taken from neonatal SD rats was cultured in lab, grafted to adult Wistar rats. The expressions of TNF-alpha and IL-2 in grafted tissue were detected with immunohistochemical staining and Western blot. RESULTS: The expressions of TNF-alpha and IL-2 were remarkable in skin allograft group, but low in tissue engineered skin group. CONCLUSION: The expressions of TNF-alpha and IL-2 and the immunological rejection were closely related after skin allograft, but the tissue engineered skin has favorable histocompatibility and doesn't arose obvious immunological rejections.

Animals↗

PubMed2003

[Transcatheter closure of atrial septal defects in 40 pediatric patients].

OBJECTIVE: To evaluate the clinical efficiency of transcatheter closure of atrial septal defect (ASD) with AGA-Amplatzer occlusion device in pediatric patients. METHODS: Forty patients with ASD, 16 males, 24 females, at a mean age of 10.2 years (ranged from 3 to 15 years of age) and with a mean weight of 35.8 kg (ranged from 11 to 87 kg) were studied. Six cases were complicated with pulmonary stenosis (PS), 1 was complicated with ventricular tachycardia (VT). Right heart catheterizations were done in 40 patients for measuring the pressures of right ventricle and pulmonary artery. The balloon diameter of ASD was measured using balloon catheter with guiding wire. The diameter of ASD was measured by TTE and/or TEE, ascertaining the location and size of ASD. Amplatzer occlusion device was sized to be equal to or 1 - 2 mm more than the diameter of balloon stretched. RESULTS: All patients had successful implantation of the Amplatzer device. The success rate was 100%. The diameter measured by TTE was 7 - 30 mm (mean 17.12 mm). The diameter measured by TEE was 7 - 32 mm (mean 18.44 mm). The diameter of balloon stretched of ASD was 8 - 34 mm. Of the 40 cases, 6 were complicated with PS and accepted percutaneous balloon valvuloplasty (PBPV). One case was complicated with VT and accepted radiofrequency catheter ablation (RFCA). Neither complication nor residual shunt was found in any of the patients. The patients were recovered and followed up for 3 or 4 days after deployment of the Amplatzer device. Clinical symptom, cardiac murmur, and findings in ECG, echocardiography and X-ray were improved markedly. CONCLUSION: AGA-Amplatzer occlusion device is safe and efficient in pediatric patients with ASD.

Adolescent↗

PubMed2003

[Effect of ferulic acid on the proliferation of nerve cells of retinas in vitro].

OBJECTIVE: To explore the possible mechanism of ferulic acid (FA) on the proliferation of nerve cells of retinas in vitro and provide the principal for prevention and treatment of some degenerative retinal diseases. METHODS: Retinal cells suspension from 7 months human embryo, neonatal calf, and 4 months postnatal mice were treated with FA, brain-derived neurotrophic factor (BDNF) and kakonein were used as placebo. 72 hours after incubation with BDNT, MTT and (3)H-thymidine ((3)H-TdR) incorporation were used to evaluate cell proliferation and DNA synthesis. RESULTS: The proliferation of three retinas cell lines was stimulated by the treatment of FA, it was shown that the effect of FA on cell viability was dose-dependent, and the highest response was seen in mice retinal cell. It has been found that to the adult mice group, FA within 15.6 to 1,000.0 mg/L was shown promotion for nerve cell proliferation, but only FA with 125.0 - 1,000.0 mg/L to that of 7 months human embryo, neonatal calf. To the 7 months human embryo group, FA with 62.5 - 1,000.0 mg/L was shown the promotion for DNA synthesis, moreover, 500.0 mg/L was most suitable for cell proliferation and DNA synthesis. BDNF with 12.5 - 50.0 microg/L was also shown promotion for nerve cell proliferation, moreover the 50.0 microg/L was the most suitable, but kakonein was not shown obvious promotional effect. CONCLUSIONS: These results suggested that FA was better for nerve cell proliferation than that of BDNF, and would probably become one of new agents for prevention and treatment of some degenerative retinal diseases.

Animals↗

PubMed2003

[Relationship between human herpesvirus 6 infection and oral squamous cell carcinoma].

OBJECTIVE: To study the relationship between human herpesvirus 6 (HHV-6) and oral squamous cell carcinoma. METHODS: The serum anti-HHV-6 antibody titers from oral squamous cell carcinoma patients and control subjects were detected by indirect immunofluorescence assay. HHV-6 DNA in peripheral blood mononuclear cells from oral squamous cell carcinoma patients and control subjects was amplified by PCR with primers from sequence of HHV-6 and the specificity was confirmed by Southern-blot hybridization with an internal probe oligonucleotide. An immunohistochemical staining using rabbit anti-HHV-6 antibody was used to detect HHV-6 antigen in oral tumor tissues from oral squamous cell carcinoma patients. RESULTS: Significantly higher proportion of patients with oral carcinoma (16/16) had IgG antibody to HHV-6 in sera compared with those (12/16) in control subjects, and geometric mean titer of these two groups was 1:118 and 1:64 respectively (P less than 0.05). The detectable rate of HHV-6 DNA in peripheral blood mononuclear cells for the above groups was 10/16 and 6/16 respectively (P less than 0.05). HHV-6 antigens were positive in 9 out of 12 oral tumor cases and in only 2 out of 8 pericancerous tissues the difference between these two groups was also significant (P less than 0.05). CONCLUSION: These results demonstrated the frequent presence of HHV-6 in oral squamous cell carcinoma, therefore, HHV-6 possibly play a role in the pathogenesis of oral squamous cell carcinoma.

Antibodies, Viral↗

PubMed2002

Human recombinant stem cell factor promotes spermatogonial proliferation, but not meiosis initiation in organ culture of newt testis fragments.

We previously showed that mammalian FSH stimulates the proliferation of newt spermatogonia and induces their differentiation into primary spermatocytes in vitro. In the current study, to examine a possibility that stem cell factor (SCF) is involved in the proliferation of newt spermatogonia and/or their differentiation into primary spermatocytes, human recombinant SCF (rhSCF) was added to organ culture of testicular fragments. rhSCF was found to stimulate the spermatogonial proliferation and the spermatogonia progressed to the seventh generation that is the penultimate stage before primary spermatocyte stage. However, the spermatogonia did not differentiate into primary spermatocytes, but instead died of apoptosis. These results indicate that rhSCF promotes the proliferation of newt spermatogonia, but not the initiation of meiosis.

Animals↗

PubMed2002

Plant tissue-based chemiluminescence flow biosensor for determination of unbound dopamine in rabbit blood with on-line microdialysis sampling.

A novel plant tissue-based chemiluminescence (CL) biosensor for dopamine combined with flow injection analysis is presented in this paper. The potato roots act as molecular recognition elements. Dopamine is oxidized by oxygen under the catalysis of polyphenol oxidase in the tissue column to produce hydrogen peroxide, which can react with luminol in the presence of peroxidase of potato tissue to generate CL signal. The CL emission intensity was linear with dopamine concentration in the range of 1x10(-5)-1x10(-7) g/ml and the detection limit was 5.3x10(-8) g/ml (3sigma) with a relative standard deviation of 1.7%. Combined with microdialysis sampling, the biosensor was applied to monitor the variation of dopamine level in the blood of rabbit after the administration of dopamine to demonstrate the favorable resolution and reliability of the system for in vivo on-line monitoring.

Animals↗