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Biomedical subjects

Xia Wang

Publications and source records attributed to Xia Wang.

At least 55 records · Page 3Linked to original sources
PubMed2005

Oct4 pseudogenes are transcribed in cancers.

Octamer-binding transcription factor 4 (Oct4) plays a critical role for maintaining pluripotent and the self-renewing state of stem cells. Recent studies demonstrated that Oct4 gene was expressed in human cancers. Six pseudogenes of Oct4 have been proposed by using bioinformatics approach to analyze the genomic nucleotide sequences. Here, we reported that an Oct4 pseudogene localized in human chromosome 10 (Oct4-pg5) and a pseudogene in chromosome 8 (Oct4-pg1) were transcribed in cancer cell lines as well as cancer tissues tested, and they were not found transcribed in embryonic carcinoma cells, human fibroblasts, and normal tissues tested. Our results suggest that pseudogenes Oct4-pg5 and Oct4-pg1 may be involved in the regulation of Oct4 gene activity thus might be pertinent to carcinogenesis. Transcription of these Oct4 pseudogenes may have contributed artifacts to the current knowledge of Oct4 gene expression and function in cancers.

Cell Line, Tumor↗
PubMed2005

Pivotal molecules of MHC I pathway in human primary hepatocellular carcinoma.

AIM: To investigate the expression of several important molecules involved in major histocompatibility complex (MHC) class I presentation pathway in primary hepatocellular carcinoma (HCC), and to determine whether cytotoxic T lymphocyte (CTL) vaccine therapy was suitable for HCC. METHODS: Labeled streptavidin biotin (LSAB) method of immunohistochemistry was used to study 33 HCC tissue specimens. RESULTS: Most HCC tissues and adjacent histological normal hepatocytes expressed HLA-I antigens,TAP, and B7, expression of B7 was especially strong, and there was no significant difference between them (P>0.05). CONCLUSION: The MHC class I presentation pathway in primary hepatocellular carcinoma may not be abnormal or dysfunctional, and CTL could kill these tumor cells. Thus, it is suitable and practicable to design and construct CTL vaccine against HCC.

Cancer Vaccines↗
PubMed2005

Essential role of the oocyte in estrogen amplification of follicle-stimulating hormone signaling in granulosa cells.

The establishment of dominant ovarian follicles that are capable of ovulating fertilizable oocytes is a fundamental determinant of female fertility. This process is governed by pituitary gonadotropins as well as local ovarian factors. Within the follicle, estrogen acts in an autocrine/paracrine manner to enhance FSH action in the granulosa cells. These effects include the augmentation of P450aromatase expression and estradiol production. This feed-forward effect of estrogen is believed to play a key role in follicle dominance. Here we found the essential role of the oocyte in this physiological process using primary cultures of rat granulosa cells. In the presence, but not absence, of oocytes, estrogen amplified FSH-stimulated increases in mRNA expression of P450aromatase, FSH receptor, LH receptor, and inhibin alpha-, betaA-, and betaB-subunits as well as cAMP production. Thus, oocytes mediate the estrogen enhancement of FSH action in the granulosa cells. In comparison with FSH, cotreatment with estrogen and oocytes failed to amplify the stimulatory effects of forskolin or 8-bromoadenosine-cAMP on granulosa cell responses including P450aromatase mRNA expression and cAMP production, indicating that estrogen/oocytes amplify FSH action at a site upstream of adenylate cyclase. These findings support the novel conclusion that communication between the oocyte and granulosa cells plays a crucial role in mediating estrogen action during FSH-dependent folliculogenesis.

8-Bromo Cyclic Adenosine Monophosphate↗
PubMed2005

Feasibility of hepatocyte transplantation-based therapies for primary hyperoxalurias.

Primary hyperoxalurias (PHs) are diseases caused by overproduction of oxalate by hepatocytes. Most patients with PHs develop nephrocalcinosis and renal failure. Combined liver-kidney transplantation is often used as a definitive treatment of PHs, but because of a large body oxalate load at the time of transplantation, the procedure is not always successful. Because all hepatocytes overproduce oxalate, partial liver replacement procedures, such as auxiliary transplantation of a liver lobe or hepatocyte transplantation are not expected to be useful in this disorder. In this paper we describe novel techniques, based on preparative hepatic irradiation and stimulation of hepatocyte mitosis, through loss of liver mass or administration of hepatic growth factor, which permit transplanted wild-type hepatocytes to massively repopulate the liver, replacing up to 90% of the hepatocytes in recipient mouse livers. Application of this procedure in a recently developed Agxt-gene-deleted mouse model of PH1 resulted in marked amelioration of hyperoxaluria. We propose that further refinement of the different components of this procedure may permit early cell-based therapies of PHs, thereby preventing renal failure and its complications.

Animals↗
PubMed2005

[Trial study on DENG Tie-tao's coronary heart disease capsules in improving patients' quality of life].

OBJECTIVE: To assess the efficacy of the Coronary Heart Disease (CHD) Capsules worked out by Prof. Deng --in improving quality of life of CHD patients of qi deficiency with phlegm and blood stasis syndrome. METHOD: According to the WHO's diagnosis criteria of CHD, a total of 93 stable angina patients were divided into 3 groups using the single blinded method. The groups were evenly distributed into CHD Capsule treated group (CHDC), isosorbide dinitrate control group (ID), and Compound Prescription Danshen Droplet Pills control group (CPDDP). Two courses of treatment lasting for 6 months were given. During the courses of treatment, the following parameters were observed: clinical symptoms of angina pectoris, ECG change, treadmill exercise test, 36 items in short form of health survey (SF-36) and Seattle Angina Questionnaire (SAQ) scale. RESULTS: After 6 months of treatment, all the three groups showed good curative effect in angina pectoris, ECG and treadmill exercise test, differences between them had no statistical significance. The CHDC group showed a better result in nitro-glycerine stopping or alleviation rate and in improving symptoms than the other groups (P < 0.05). The general health, vitality, role-emotional, mental health and reported health transition in the CHDC group were significantly better than those in the control groups (P < 0.05). The scores in physiological functioning role, physiological function and pain alleviation were not different among the three groups. CONCLUSION: Prof. DENG Tie-tao's CHDC is effective in treating CHD with qi deficiency, phlegm and blood stasis and also in improving the quality of life. CHDC is more suitable to be used in long-term treatment than isosorbide dinitrate. The SF-36 and SAQ can be used to appraise the curative effect of traditional Chinese medicine agents for CHD angina pectoris.

Aged↗
PubMed2005

Studies of the anticancer effect of calcineurin B.

Calcineurin (CN) is a Ca (2+)/calmodulin-stimulated protein phosphatase. It is a heterodimeric enzyme consisting of a catalytic subunit (CN A) and a Ca2+ -binding regulatory subunit (CN B), which plays an important role in the human immune system. Its regulatory subunit, CN B, on its own, was found to have a remarkable anticancer effect in mice. To clarify the basis of this action the in vivo and in vitro effect of CN B on several types of mice immunocytes was investigated. The phagocytic activity of peritoneal macrophages of both normal mice and mice bearing S 180 solid tumors increased when CN B was injected daily. In vitro examination using a modified MTT assay and an [3H] incorporation assay showed that the cytotoxicity of peritoneal macrophages was increased substantially. CN B also increased the natural killer activity of murine spleen lymphocytes in vivo and in vitro, and synergized with concanavalin A in stimulating their proliferation. Our results indicate that CN B has a significant stimulatory action on the immune system that may partially account for its anticancer activity.

Animals↗
PubMed2005

Comparison of the educational deficiencies of delinquent and nondelinquent students.

This article assesses the differences in educational deficiencies between a statewide sample of delinquent students and a matched sample of nondelinquent students. Employing a research design that controls for a series of relevant individual and school variables, the study's findings document that delinquent students are characterized by a series of disproportionate educational deficiencies as compared to their nondelinquent student counterparts. Delinquent students were found to attain lower grade point averages, have poorer school attendance records, be retained more often in the same grade, and receive more school disciplinary actions. The article concludes that these documented educational deficiencies may play an integral role in the process of delinquency and, therefore, pose a number of public policy implications in relation to the prevention and treatment of delinquency.

Adolescent↗
PubMed2005

Normal-phase HPLC enantioseparation of novel chiral metal tetrahedrane-type clusters on an amylose-based chiral stationary phase.

In the present work, an amylose tris(3,5-dimethylphenylcarbamate) (ADMPC) chiral stationary phase (CSP) was prepared by coating ADMPC on small-particle silica gel. This ADMPC-CSP was for the first time successfully applied to separate a series of novel chiral metal tetrahedrane-type clusters. Furthermore, the influence of a mobile-phase modifier (various alcohols added in the mobile phase), including its concentration and structure, and the structures of the clusters on the chiral separation and retention was investigated. The results suggest that not only the structure and concentration of alcohol in the mobile phase, but also the subtle structural differences in racemate can have a pronounced effect on the enantiomeric separation and retention.

Journal Article↗
PubMed2005

[Effects of chromium supplementation on IRS-1 expression of skeletal muscle in diabetic rats].

OBJECTIVE: To study the effects of chromium supplementation on related gene expression to metabolism of skeletal muscles in diabetic rats. METHODS: cDNA fragments from the out related research were cloned, sequenced and its comparalarity analysis has been done. The RT-PCR were made using the primers designed according to the sequence of cDNA. RESULTS: The identities between the sequence of Cr-5 and IRS-1 is 100%. The expression level of DM group (0.791 +/- 0.038) is obviously lower than those of normal group (0.892 +/- 0.053, P < 0.05). And The expression level of DM + Cr group (0.822 +/- 0.066) have some improvement compare to those of DM group (P > 0.05). CONCLUSION: There is a tendency that Chromium supplementation can increase the expression level of IRS-1 mRNA of skeletal muscles in diabetic rats. It will be studied as a candidate gene in future research.

Animals↗
PubMed2005

[The expression of Fas and bcl-2 in hamster buccal carcinogenesis].

PURPOSE: To study the expression of Fas and bcl-2 in oral carcinogenesis. METHODS: Using immunohistochemical method,we studied the expression of Fas and bcl-2 in DMBA induced hamster baccal carcinogenesis including negative control (14), hyperkeratosis (7), epithelial dysplasia (mild 12, moderate 7, severe 9), oral squamous cell carcinoma(OSCC) (25). Non-parametric test was used for statistical analysis. RESULTS: Fas was expressed in negative control consistently except stratum basale,and there was down-regulation in oral dysplasia and OSCC (chi(2)=45.576, P<0.05).bcl-2 was rarely expressed in negative control, and there was up-regulation in oral dysplasia and OSCC (chi(2)=19.433, P<0.05). CONCLUSIONS: Fas and bcl-2 may play an important role in inhibiting apoptosis coordinately, resulting in the imbalance of cell proliferation and apoptosis, which may contribute to oral carcinogenesis.

Animals↗
PubMed2005

[Effects of alcohol on the expression of heat shock protein 70 and super microstructure of astrocytes in rat embryonic brain].

OBJECTIVE: To explore effects of alcohol on the expression of heat shock protein 70 (HSP70) and super microstructure of astrocytes. METHODS: Different dosage of alcohol (1, 5, 25, 50mmol/L) was administered to astrocytes of rat embryos. Effects of alcohol on expression of HSP70 were studied by immunocytochemistry, and changes of super microstructure of astrocytes were observed by electron microscope. RESULTS: The results showed that with increase of alcohol dosage, the expression of HSP70 increased, hepatin granule and survival astrocytes in 25mmol/L and 50mmol/L dosage group decreased, cell membrane and mitochondrion were damaged, and even apoptosis and necrosis occurred. CONCLUSION: It suggested that alcohol could increase expression of HSP of astrocytes, which could depress the expression of normal function protein, and mainly impaired cell membrane and mitochondrion, which could lead to apoptosis and necrosis.

Animals↗
PubMed2005

[Regulation of chromium on gene expression of skeletal muscles in diabetic rats].

OBJECTIVE: To study the regulation of chromium on gene expression related to metabolism of skeletal muscles in diabetic rats. METHODS: Male Wistar rats were assigned to three groups: normal control group (NC), alloxan-induced diabetic control group (DM), and DM with chromium supplementation group (DM + Cr). 200 microg Cr/kg bw perday was supplemented orally for 60 days. At the end of the treatment, the changes in gene expression among three groups were studied by mRNA differential display technique combined with cDNA fragments cloning, sequencing and BLASTn analysis. RESULTS: 11 cDNA fragments larger than 400bp expressed differences in skeletal muscles between DM + Cr group and DM group were isolated, 4 of them expressed higher in DM + Cr group, while the rest expressed higher in DM group. Cr-3 and GLUT4 are homologous with sequence identities of 98% and Cr-5 and IRS-1 are homologous with sequence identities of 100%. The expression level of GLUT4 mRNA in DM + Cr group are higher than those of DM group. CONCLUSION: Chromium supplementation could induce the expression of GLUT4 mRNA on skeletal muscles in diabetic rats. It may be one of the molecular mechanisms that chromium could improve the disorders of glucose and lipids metabolism in diabetic rats.

Animals↗
PubMed2005

[Expression of gastrin in human gastric cancer cell line and effect of anti-gastrin mAb on the cell growth].

OBJECTIVE: To investigate the expression of gastrin in human gastric cancer cell line SGC-7901 and the effects of gastrin-17 and anti-gastrin mAb on its growth. METHODS: The expression of gastrin was determined by immunohistochemistry with anti-gastrin mAb prepared by our group. In a series of experiments, the growth of SGC-7901 cells was evaluated by MTT assay on cells grown in serum-free medium and treated with gastrin-17 and/or anti-gastrin mAb. RESULTS: Immunohistochemical examination of SGC-7901 cells revealed a specific gastrin immunoreactivity. Gastrin-17 significantly stimulated cell growth at the concentrations of 1 x 10(-9) mol/L approximately 1 x 10(-5) mol/L in a dose-dependent manner. The growth of SGC-7901 cells treated with anti-gastrin mAb, either alone or in combination with gastrin-17 (1 x 10(-7) mol/L), was significantly inhibited. CONCLUSION: Growth of human gastric cancer cells SGC-7901 can be stimulated in an autocrine fashion. The gastrin-stimulated growth of gastric cancer cells can be blocked by anti-gastrin mAb bound specifically with gastrin. Further study on the significance of anti-gastrin mAb in designing immunotherapy targeting to gastrin or gastrin receptor is warranted.

Antibodies, Monoclonal↗
PubMed2005

[Infiltration of DCs and CD4+ T cells in muscle after DNA immunization].

OBJECTIVE: In order to get a better understanding of the mechanism of DNA initiating specific cytotoxicity T lymphocyte (CTL) immune response, we observed the local infiltration in injection site at different time after DNA immunization and further studied the characters of infiltration cells. METHODS: The local infiltration in injection sites was observed by HE staining at 6 h, 12 h and 1-6 days after DNA immunization. Infiltration cells were further studied with the mice dendritic cells marker CD205, T lymphocyte marker CD4 and CD8 by immunohistological methods. RESULTS: phAFP injection into mouse muscle led to a local infiltration. Infiltrates reached peak at 3-6 days after injection and appeared in several discrete clusters within the muscles. The predominant cell types found in infiltrates were macrophage-like cells and lymphocytes. Immunohistological staining revealed CD205+ and CD4+ cells. CD4+ cells could be detected in any of the injected muscles. CD205+ cells were only seen at 24 h to day 3, appearing later and disappearing earlier than CD4+ cells. However, CD8+ immunostaining positivity could not be found. CONCLUSION: Our findings indicate that the character of local infiltration after DNA immunization is different from the inflammation of injection. The recruitment of CD205+ to the injection site suggests that DCs and Th cells play an important role in DNA immunization.

Animals↗
PubMed2005

[Simultaneous determination of four fluoroquinolone residues in edible chicken tissues by reversed-phase high performance liquid chromatography].

A reversed-phase high performance liquid chromatographic method with fluorescence detection was developed for the simultaneous analysis of ciprofloxacin, danofloxacin, enrofloxacin and sarafloxacin residues in edible chicken tissues. The analytes were extracted from chicken muscle, skin and fat, liver, kidney by aqueous potassium dihydrogenphosphate of different pH values through homogenization. The supernatant of the extract was applied onto a C18 solid phase extraction cartridge for clean-up. The separation was achieved on a C18 column, and the detection was performed with a fluorescence detector (excitation at 280 nm and emission at 450 nm). The four fluoroquinolones were analyzed in spiked samples of four chicken tissues with mean recoveries in the range of 53.9%-93.4% at spiked levels of 20-300 microg/kg. The relative standard deviations of inter-assay were no more than 23%. The detection limits of quantification were 20 microg/kg for ciprofloxacin, enrofloxacin and sarafloxacin and 4 microg/kg for danofloxacin. The method is simple, fast, and sufficient for routine analysis.

Animals↗
PubMed2005

[Immunohistochemical study of RET protein in Hirschsprung's disease and allied Hirschsprung's disorder].

OBJECTIVE: Hirschsprung's Disease (HD) and allied Hirschsprung's disorder (HAD) have very similar clinical manifestations, but there are many different theories about the two diseases. The present study was designed to understand the expression of Ret protein in HD and HAD, and to explore the role of Ret protein in the pathogenesis of HD and HAD. METHODS: Colon specimens from patients with confirmed HD and HAD, including 15 cases of HD (male 12, female 3) and 11 cases of HAD (male 8, female 3) were collected for this study. At the same time normal colon specimens from 10 individuals with other diseases were used as control. The expression of Ret protein in the intestinal tissue was detected by using immunohistochemical SABC technique with mouse anti-Ret monoclonal antibody. RESULTS: In the colon specimens from normal controls and the dilated segments of colon from HD and HAD patients, moderate to large number of Ret-positive cells were observed among the ganglion cells of myenteric plexuses and submucosal plexuses (P > 0.05). On the contrary, Ret-positive cells were not seen in the stenotic segment of colon from HD patients. But there was positive staining in the stenotic segment of the colon from HAD. Moreover, giant ganglion cells showing strongly positive staining could be seen. There were also displastic cells, small cells, and cells with irregular shape. Statistical analysis showed significant differences in Ret cells positivity between the stenotic segment of colon of HD and the normal control (P < 0.001) as well as between HD and HAD (P < 0.001). CONCLUSION: Ret protein may play an important role in the pathogenesis of HD and could not have definite relationship with HAD.

Case-Control Studies↗