Biomedical subjects

Xin Huang

Publications and source records attributed to Xin Huang.

115 records · Page 7Linked to original sources

PubMed2002

[Transforming growth factor-beta superfamily in the regulation of new bone formation].

OBJECTIVE: To review the recent advances in transforming growth factor-beta(TGF-beta) superfamily study and its role in new bone formation. METHODS: The latest original articles related to this subject were retrieved extensively, especially the effect of TGF-beta, bone morphogenetic proteins(BMPs) and activin(ACT) on distraction osteogenesis. RESULTS: TGF-beta, BMPs and ACT play important roles in prompting new bone formation and each of them has different effects. Among them, TGF-beta can stimulate the proliferation of osteoblast and synthesis of extra cellular medium; BMPs can initiate the differentiation of interstitial cell to osteocyte; then ACT displays the combine effect of above two factors. CONCLUSION: TGF-beta superfamily can regulate new bone formation and thus shorten the course of mandibular distraction osteogenesis.

Activins↗

PubMed2002

[Expression of activins, follistatin mRNA in the development of hepatic fibrosis].

OBJECTIVE: To examine the expression changes of activin beta A, beta C, beta E and follistatin mRNA in the development of rat hepatic fibrosis induced by carbon tetrachloride (CCl(4)). METHODS: Hepatic fibrosis was induced in rats by subcutaneous injections of 40% carbon tetrachloride oily solution for a period of 1 to 7 weeks. After carbon tetrachloride injection of 1, 2, 3, 4, 5, 6, and 7 weeks, the 6-12 rats were killed every time. The kinetics of activin beta A, beta C, beta E and follistatin mRNA expression were assessed by the semi-quantity RT-PCR. RESULTS: Activin beta A, beta C, beta E and follistatin mRNA could be detected in normal rat livers. After CCl(4) injection for 2 or 3 weeks, beta A mRNA was transiently decreased and became undetectable, then increased gradually. After CCl injection for 6 and 7 weeks, beta A mRNA level was significantly higher than controls (P<0.01). beta C mRNA could be detected after CCl(4) injection for 1 to 4 weeks and was significantly increased after 5 weeks over controls (P<0.05). beta E mRNA could not be detected after CCl(4) injection for 1 to 5 weeks, but significantly increased after CCl(4) injection for 6 or 7 weeks compared with controls (P<0.01). Except for normal rat liver, no follistatin mRNA was detected in rats after CCl(4) injection. CONCLUSIONS: Activins and follistatin have different expression changes in the development of hepatic fibrosis and the imbalance of activins and follistatin expression may involve in the formation of hepatic fibrosis.

Activins↗

PubMed2002

[Study on the near, middle and long distance stereopsis of normal and children with intermittent exotropia].

OBJECTIVE: To study the pre- and post-operative changes of stereopsis at different distances in normal and children with divergence in excess type of intermittent exotropia. METHODS: TNO and new stereo tests (NST) and the middle and long distance stereotest were used for the evaluation of stereoacuity at 40 cm - 5 m in 844 normal and 35 children aged 4 - 12 years with divergence excess type of intermittent exotropia undergoing operative correction of strabismus. RESULT: (1) Normal subjects: The TNO test showed that the near distance stereoacuity </= 60" was in 98% subjects aged 4 - 8 years. The stereoacuity was increased with the increase of age, the correlation being linear. The stereoacuity in children aged 10 - 11 years was the lowest. In the comparison of stereoacuity between children aged 4 - 8 years and 9 - 12 years, the difference in distribution was very significant (P < 0.01). The NST test showed that the near stereoacuity >/= 40" was in 97% subjects. The mean stereoacuity was 40" - 42" in children various in age. The middle and far distance stereoacuity was the greatest in children aged 4 years, along with the increase of age, it was gradually declined and at 9 - 10 years it was the lowest. (2) Divergence excess type of intermittent extropia: There was no significant difference between the pre- and post-operative near stereoacuity examined by TNO and NST (P > 0.05) The pre-operative middle and long distance stereoacuities were greater than that in the normal children, the difference being significant (P < 0.05). The post-operative middle distance stereoacuity was improved and approximately normal in comparison with that before the surgery, and the far distance stereoacuity was improved mildly. CONCLUSIONS: (1) In the normal group, the development of stereopsis at different distances begins at 4 years, keeping on developing with the increase of age, and the stereoacuity is elevated after 8 years and in 9 - 11 years well developed. (2) In the group of divergence excess type of intermittent exotropia, the pre-operative near stereoacuity is well, but the middle and far distance stereoacuities are poor and the middle stereoacuity improves significantly after the surgery. The recovery of middle distance stereoacuity seems to be an objective criterion of the operative therapeutic effect.

Age Factors↗

PubMed2002

[Relationship between expressions of p53, c-erbB2 genes, proliferating cell nuclear antigen and prognosis of patients with ovarian epithelial carcinoma].

BACKGROUND & OBJECTIVE: There were a few reports about the relationship between the expressions of p53, c-erbB2 Genes, and proliferating cell nuclear antigen (PCNA) with the prognosis from the patients with ovarian epithelial carcinoma(EOC). But conclusions were difference because of various methods and samples. This study was designed to investigate the relationship between the expressions of p53, c-erbB2 Genes, and PCNA with the prognosis from the patients with EOC. MATERIALS & METHODS: A total of 84 female patients with EOC were enrolled in this study, who were hospitalized in Department of Gynecology, Cancer Center, Sun yat-sen University from March 1 1990 to March 31 1994. The expressions of p53, c-erbB-2, and PCNA from the tumor samples were detected by Labelling-streptavidin-biotin (LSAB) immunohistochemistry assay. The relationship between the expression of the above marks and the prognosis of the patients were then analyzed. Statistical analyses were performed using SPSS 8.0 softwave. RESULTS: Forty-nine tumor samples (58.3%) exhibited p53 overexpression, 65 (77.4%) exhibited c-erbB2 overexpression, and all (100%) exhibited PCNA overexpression. In univariate analysis, there was marginally significant difference in the mean survival, the 5 years survival between the patients exhibited no c-erbB2 overexpression and the patients exhibited any c-erbB2 overexpression (P = 0.05). There was significant difference in the mean survival, the 5 years survival between the patients showed lower expression of PCNA and those showed higher expression of PCNA (P < 0.01), and there was no significant difference in the mean survival, the 5 years survival between the patients with overexpression of p53 and without overexpression of p53 (P > 0.05). In multivariate analysis, only stage and histological grade were the important significant prognostic factors of the patients with EOC, and there was no statistical significance between the overexpression of c-erbB-2 and PCNA with the prognosis. CONCLUSIONS: There was no significant correlation between the overexpression of p53 gene and the prognosis of the patients with EOC. The expression of c-erbB2 or PCNA was not an independent prognostic factor for prognosis of the patients with EOC. Stage and histological grade were still the independent significant prognostic factors of EOC.

Adolescent↗

PubMed2000

Effects of AT1 receptor antagonist, losartan, on rat hepatic fibrosis induced by CCl(4).

AIM:To investigate effect of losartan, an AT1 receptor antagonist, on hepatic fibrosis induced by CCl(4); and to determine whether or not AT1 receptors are expressed on hepatic stellate cells. METHODS AND RESULTS:Fifty male Sprague-Dawley rats, weighing (180 plus minus20)g, were randomized into five groups (control group, model group, and three losartan treated groups), in which all rats were given the subcutaneous injection of 40% CCl(4)(every 3 days for 6 weeks) except for rats of control group. Rats of losartan-treated groups were treated with losartan (20 mg/kg, 10 mg/kg, 5 mg/kg, daily gavage). After 6 weeks liver tissue and serum samples of all rats were examined. Serum hyaluronic acid (HA), procollagen type III (PC III) were detected by radioimmunoassays. van Giesion collagen staining was used to evaluate the extracellular matrix of rats with liver fibrosis. The expression of AT1 receptors, transforming growth factor-beta (TGF-beta), and alpha-smooth muscle actinalpha-SMA) in liver tissue were determined by immunohistochemical techniques. Compared with model group, serum ALT and AST of losartan-treated groups were significantly reduced (italic>t = 4.20,P < 0.01 and italic>t = 4.57,P < 0.01). Serum HA and PC III also had significant differences (italic>t = 3.53,P<0.01 and t=2.20, P<0.05). The degree of fibrosis was improved by losartan and correlated with the expressions of AT1 receptors, TGF-beta, and alpha-SMA in liver tissue.CONCLUSION:AT1 receptor antagonist, losartan, could limit the progression of the hepatic fibrosis induced by CCl(4). The mechanism may be related to the decrease in the expression of AT1 receptors and TGF-beta, ameliorating the injury of hepatocytes; activation of local renin-angiotensin system might relate to hepatic fibrosis; and during progression of fibrosis, activated hepatic stellate cells might express AT1 receptors.

Journal Article↗

PubMed2000

The regulatory role of AT 1 receptor on activated HSCs in hepatic fibrogenesis:effects of RAS inhibitors on hepatic fibrosis induced by CCl(4).

AIM:To assess the effect of ACE inhibitor and Ang II type 1 (AT1) receptor antagonist in preventing hepatic fibrosis caused by CCl(4) administration in rats;to investigate whether or not there are expression of AT 1 receptors on hepatic stellate cells; and to observe the effect of Ang II on proliferation and ECM synthesis of cultured HSCs.METHODS:Studies were conducted in male Sprague-Dawley rats. Except for the hepatofibrotic model group and the control group, in three treated groups, either enalapril (5mg/kg), or losartan (10mg/kg), or enalapril + losartan were given to the fibrotic rats by daily gavage, and saline vehicle was given to model and normal control rats. After 6 weeks, liver fibrosis was assessed directly by hepatic morphometric analysis, which has been considered the gold standard for the quantification of fibrosis. The expressions of AT 1 receptors and (alpha-mooth muscle actin,alpha-SMA) in liver tissue or isolated hepatic stellate cells (HSCs) were detected by immunohistochemical techniques. The effect of Ang II on HSC proliferation was determined by MTT method. Effect of Ang II on collagen synthesis of HSCs was determined by (3)H-proline incorporation.RESULTS:Contrasted to the fibrosis in rats of the model group, groups of rats treated with either enalapril or losartan, or a combination of two drugs showed a limited expansion of the interstitium (4.23 plus minus 3.70 vs 11.22 plus minus 4.79, P<0.05), but no difference was observed among three treated groups (5.38 plus minus3.43, 4.96 plus minus 2.96, 4.23 plus minus 2.70, P>0.05). Expression of AT 1 receptors was found in fibrotic interstitium of fibrotic rats, whereas in normal control rats they were limited to vasculature only to a very slight degree. AT 1 receptors were also expressed on activated HSCs in the culture. At concentrations from 10(-9) to 10(-5)mol/L, Ang II stimulated HSC proliferation in culture in a dose dependent manner. Increasing Ang II concentrations produced corresponding increases in (3)H-proline incorporation. Differences among groups were significant.CONCLUSION:Angiotensin converting enzyme inhibitors and AT 1 blocker may slow the progression of hepatic fibrosis;activated HSCs express AT 1 receptors, and Ang II can stimulate the proliferation and collagen synthesis of HSCs in a dose-dependent manner; and activation of RAS may be related to hepatic fibrogenesis induced by CCl(4).

Journal Article↗

PubMedDate not supplied

Adenovirus-mediated tissue-specific cytosine deaminase gene therapy for human hepatocellular carcinoma with different AFP expression levels.

To evaluate whether in vitro and in vivo transferring of Escherichia coli cytosine deaminase gene to a solid tumor will confer the sensitivity to the prodrug 5-fluorocytosine (5FC) on these cells, we constructed two replication-defective adenovirus vector in which the cytosine deaminase gene was driven by CAG promoter (Adex1CACD) and AFP gene 5'-flanking region (Adex1AFPCD), respectively. By transferring these two vectors to SMMC7721AFP(-) and HepG2 human hepatocellular carcinoma (HCC) cells in vitro, we found that Adex1CACD vector could effectively suppress SMMC7721AFP(-) and HepG2 cells growing in the presence of 5FC even if the infected cell is less to 20%, while Adex1AFPCD vector only conferred HepG2 cells sensitivity to 5FC. When Adex1CACD was directly injected into established subcutaneous SMMC7721AFP(-) tumors in nude mice receiving 5FC, the tumor growth was inhibited significantly, which was consistent with those in vitro results. Furthermore, the Adex1AFPCD plus 5FC suppressed SMMC7721AFP(+) tumor growth in vivo, but not SMMC7721AFP(-) tumor. The results suggested that the CAG promoter-controlled CD gene could effectively mediate the growth inhibition in different kinds of HCC combined with administration of 5FC, and the AFP promoter-controlled CD gene could only suppress the HCCs expressing high levels of AFP. Therefore, adenovirus-mediated tumor-specific gene transfer may be a potential strategy for local control of tumor growth.

Adenoviridae↗