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Biomedical subjects

Wei Zhang

Publications and source records attributed to Wei Zhang.

At least 325 records · Page 18Linked to original sources
PubMed2006

Synergistic effect of schwann cells and retinoic acid on differentiation and synaptogenesis of hippocampal neural stem cells in vitro.

OBJECTIVE: To investigate the synergistic effect of Schwann cells (SCs) and retinoic acid (RA) on differentiation and synaptogenesis of neural stem cells (NSCs) derived from hippocampus of neonatal rats. METHODS: The classical method for 2x2 factorial analysis experiment was used to assess synergistic action of SCs and RA. NSCs were treated with RA, SCs, and SCs + RA in DMEM/F12 with 0.5% fetal bovine serum for six days, respectively. Double immunofluorescent staining was used to detect the differentiation of NSCs including nestin, glial fibrillary acidic protein (GFAP) and Map2. The expression of PSD95 was used to demonstrate synaptogenesis. RESULTS: After NSCs were treated with RA or SCs, the expression of nestin and GFAP was significantly decreased while the expression of Map2 and PSD95 was significantly increased in comparison with the control. Factorial ANOVA showed that interactions between SCs and RA could induce the expression of Map2 and PSD95. CONCLUSION: SCs and RA could promote synergistically the neuronal differentiation and synaptogenesis of hippocampal neural stem cells in vitro while they decreased the astrocytes and nestin positive NSCs.

Animals↗
PubMed2006

[Inhibition of human macrophage-derived foam cell differentiation by blocking Kv1.3 and Kir2.1 channels].

OBJECTIVE: To investigate the expression of Kv1.3 and Kir2.1 during human monocyte-derived macrophages differentiation into foam cells and their function in foam cells formation. METHODS: The human macrophage-derived foam cells were obtained by incubating macrophages with ox-LDL (30 mg/L) for 60 h. The expression of Kv1.3 and Kir2.1 channels were examined by immunocytochemistry, RT-PCR and Western blot. Effects of channel blockers (rMargatoxin and BaCl2) on the cellular cholesterol metabolism were studied by measuring the cellular contents of total cholesterol (TC), free cholesterol (FC), and cholesterol ester (CE) in the presence or absence of the channel blockers. RESULTS: After incubating macrophages with 30 mg/L ox-LDL for 60 h, the cellular contents of TC, FC and CE were markedly increased and the ratio of CE/TC was raised from (14.4+/-6.8)% to (57.9+/-3.5)% (P<0.05), which indicated that the cells had differentiated into foam cells. The expression of Kv1.3 and Kir2.1 channels appeared no obvious difference when differentiating into foam cells (P>0.05); After being blocked specifically (rMargatoxin: 0.1, 10 nmol/L; BaC(12): 75, 125 micromol/L), the cellular contents of TC and CE were markedly reduced without exception and the ratios of CE/TC were all less than 50% (P<0.05). CONCLUSION: Both Kv1.3 and Kir2.1 channels play a critical role in differentiation of macrophages into foam cells and blockage of corresponding potassium channels would prevent the formation of the foam cells.

Barium Compounds↗
PubMed2006

[Effects of hyperthermic chemotherapy on gastrointestinal cancer cells in vitro].

BACKGROUND & OBJECTIVE: Little evidence is known from experimental research for intraoperative hyperthermic intraperitoneal chemotherapy. This study was to investigate the effect of hyperthermic chemotherapy on gastrointestinal cancer cells in vitro and explore the possible factors which may affect this method. METHODS: Gastric cancer cell line MGC-803 and intestinal cancer cell line HCT-116 were chosen. Cells were treated with different drugs, temperatures and duration. Cell viability and growth were measured by MTS-PMS assay. The morphology of the cells was observed under a microscope. RESULTS: Significant synergistic effect was observed when the two cancer cell lines were treated with 5-FU, MMC, DDP and THP in combination with elevated hyperthermia from 41 degrees C to 45 degrees C compared with control group (P<0.01). The strongest effect was achieved at 45 degrees C, which the inhibitory effects of these four drugs were 61.7%, 79.2%, 88.7%, 94.7% on MGC-803 and 76.4%, 78.7%, 77.8%, 91.7 on HCT-1116, respectively. The inhibitory effect demonstrated a time and dose-dependent manner in HCT-116 cells within a certain period of time. The effect revealed a flat curve after 90 min when HCT-116 was treated with 43 centigrade. THP had the strongest effect at any conditions among all tested drugs (P<0.01). Either simple thermotherapy or chemohyperthermia displayed considerable killing effects on cancer cells which were confirmed by microscope observation. And a great deal of dead cells were observed when treated with chemohyperthermia. CONCLUSIONS: DDP or MMC reveals relatively satisfactory antitumor effects with the optimal temperature of 43-45 degrees C. Taken practical application into consideration, 60 min may be selected in clinical use. Synergistic antitumor effects of THP in combination with hyperthermia were prior to 5-FU, DDP or MMC, which deserve further clinical research.

Antibiotics, Antineoplastic↗
PubMed2006

Vasculogenic mimicry is associated with high tumor grade, invasion and metastasis, and short survival in patients with hepatocellular carcinoma.

Vasculogenic mimicry (VM) has increasingly been recognized as a form of angiogenesis. In VM, epithelial cells are integrated into the malignant tumor vasculature. An association has been observed between VM and poor clinical prognosis in some malignant tumors. However, whether VM is present and clinically significant in hepatocellular carcinoma (HCC) is unknown. In this study, we determined whether VM was present in HCC and whether it was associated with tumor grade, invasion and metastasis, and survival duration. We collected paraffin-embedded HCC tumor samples, along with complete clinical and pathologic data for all the cases, and performed immunohistochemical staining for CD31, CD105 (endoglin), hepatocyte, vascular endothelial growth factor, matrix metalloproteinase (MMP)-2, and MMP-9. The VM status was compared with the clinical and pathological data using statistical tests. Kaplan-Meier survival analysis and log-rank test were used to compare survival durations between patients with and without VM. The VM vessel cells were CD31 and CD105-negative and hepatocyte and vascular endothelial growth factor-positive, showing that they were not derived from endothelial cells but were HCC tumor cells. Patients with VM had a higher metastasis rate than did those without VM (P=0.003). Consistent with this finding, MMP-2 and MMP-9 were present in all the VM cases but were found less frequently in non-VM cases (P<0.05). The Kaplan-Meier survival analysis showed that patients in the VM group had a significantly shorter survival duration than did those in the non-VM group. In conclusion, VM is a marker of poor clinical prognosis in HCC: Its presence may be associated with a high tumor grade, invasion and metastasis, and short survival.

Aged↗
PubMed2006

Skewed X chromosome inactivation of blood cells is associated with early development of lung cancer in females.

The skewed X chromosome inactivation (SXCI) was found mainly in adult females. It has been linked to development of ovarian and breast cancers. The present study aimed to describe the relationship between SXCI and development of lung cancer in females. DNA was isolated from blood cells from patients with primary lung cancer (n=148) and reference subjects (n=289). The androgen receptor (AR) gene exon 1 was amplified, with its products from different alleles resolved on denaturing polyacrylamide gels and visualized by silver staining. The corrected ratio (CR) between products from AR alleles after and before HpaII pretreatment was calculated. Occurrence of SXCI was detected in both the patients and reference subjects at similar frequency. However, the phenomenon was more frequent in the patients below 40 years compared to the corresponding reference group, either taking CR >/=3 (25 and 5.8%, respectively; P=0.048) or CR >/=10 as the criterion of SXCI (16.7 and 0.8%, respectively; P=0.022). A higher frequency of SXCI was also found in the patients below 50 years compared to that for the corresponding reference group when CR >/=10 adopted as the criterion (7.9 and 1.2%, respectively; P=0.046). The cancer patients with SXCI were more than 10 years younger in average age than those without SXCI. SXCI of blood cells is associated with early development of lung cancer in females. The X chromosomal inactivation assay, therefore, may be used to screen for females predisposed to malignancies including lung cancer.

Adolescent↗
PubMed2006

[Research of Hg2+ sol-gel membrane made of organically modified silicates].

A photochemical sensor for the determination of Hg2+ consisting of organically modified silicates (ormosils) was developed. Hg(2+)-sensitive fluorescent sol-gel films were prepared by co-condensation of tetramethoxysilane (TMOS) and dimethyldimethoxysilane (DMOS), and the fluorescent indicator 5,10,15, 20-tetra (p-sulfonatophenyl) porphyrin sodium was embedded in sol-gel in the form of ion pairs with cetyltrimethyl ammonium bromide. The optimization condition of preparation and response performance of sol-gel membrane were investigated. The experimental results showed a linear range of Hg2+ concentrations from 1.0 x 10(-5) to 1.0 x 10(-4) mol x L(-1) in a Tris-HCl buffer at pH 8.0 with fast response and good repetition. The indicators in the sol-gel membrane did not leak out and the sensor showed good selectivity over other metal ions.

Gels↗
PubMed2006

[Fhit expression and its relationship with apoptosis and prognosis in nasal and paranasal sinus carcinomas].

OBJECTIVE: To assess the protein expression of Fhit and its correlation with spontaneous apoptosis, tumor clinicopathological parameters and prognosis in nasal and paranasal sinus carcinomas. METHOD: Forty-eight patients with NPSC treated by radical operations from 1991 to 2000 were studied retrospectively. Patients included 23 female and 25 male ranging in age from 20 to 71 years. Spontaneous apoptotic cells were visualized by TUNEL accompanied by HE and PI stain. Immunohistochemistry using SP method was used to assess the expression of Fhit. RESULT: The loss of expression of Fhit was found in 26 patients (54.17%, 26/48). Comparing with abutting non-neoplastic tissue, reduced expression of Fhit was found in 16 (16/29, 55.17%) patients. The adenoid cystic carcinoma showed stronger expression of Fhit than squamous cell carcinomas (P <0.05). The expression of Fhit correlated positively with apoptosis index (r = 0.379, P < 0.01). Patients with positive expression of Fhit had much better prognosis than those with abnormal expression (P < 0.05). CONCLUSION: The reduced expression of Fhit may be associated with carcinogenesis and prognosis of nasal and paranasal sinus carcinomas. It could be the tumor suppressor gene and realize its function through accelerating apoptosis in this kind of neoplasm. Fhit expression may provide a novel predictive indicator for disease-free survival after surgical resection and postoperative radiochemotherapy in nasal and paranasal sinus carcinomas.

Acid Anhydride Hydrolases↗
PubMed2006

[Research advances in ecotoxicology and risk assessment of chemical mixtures at low doses].

Chemicals in the environment often exist as mixtures and at low doses, whose ecotoxicological diagnosis and risk assessment are hard to be done with the help of the research results on the ecotoxicity of high-level exposure of single chemicals. This paper reviewed the research advances in ecotoxicology and risk assessment of low-dose chemical mixture contamination, with the focus on the molecular toxicological methods and the risk assessment approaches and schemes of simple and complex mixtures. Comments were given on the development directions of low-dose chemical mixture research, including the necessity of searching for sensitive endpoints, involving the approaches of other disciplines, increasing data accumulation, and setting up a comprehensive and identical risk assessment system.

Dose-Response Relationship, Drug↗
PubMed2006

[Determination of safflor yellow A by RP-HPLC and resources quality comparison in Carthamus tinctorius].

OBJECTIVE: To provide the basis for establishing evaluation criterion, selecting good strains and carring out good agricultural practice of the crude drug. METHOD: Representative 22 varieties of Carthamus tinctorius were selected and cultivated in different ecological localities and different years. And the content of safflor yellow A in their corollas were measured by RP-HPLC to compare the differences and their genetic stabilities among varieties. RESULT: The range of of safflor yellow A content was 0.70%-1.85% which were varied among varieties (P < 0.01). The content of safflor yellow A in varieties Yutai Honghua, Hefei Honghua, Rucheng Honghua were higher than in others. CONCLUSION: The effective compound safflor yellow A in C. tinctorius was one of the main quality evaluation criterions. Varieties Yutai Honghua, Hefei Honghua and Rucheng Honghua were good resources.

Carthamus tinctorius↗
PubMed2006

[Hepatic progenitor cell activation and expansion in human liver cirrhosis].

OBJECTIVES: To confirm whether human hepatic progenitor cells (HPCs) occur in human liver cirrhosis, to investigate the relationship between the degree of HPCs activation and the degree of liver inflammation and to provide evidence that HPCs can differentiate into hepatocytes. METHODS: Surgical specimens from 30 human cirrhotic livers and from 3 normal livers were investigated by light microscopy and immunohistochemical staining for CK7 (a marker of biliary differentiation) and SMA (a marker of hepatic stellate cell activation). The degree of portal inflammation was determined on routine stained sections. The number of HPCs and intermediate hepatocytes and the extent of the ductular reaction were assessed. RESULTS: HPCs and ductular reaction were not observed in the normal livers. In liver cirrhosis cases the HPCs originated from the portal areas. With the increase of portal inflammation, HPCs and ductular reaction extending from the periphery of the liver cirrhosis nodules to the liver parenchyma and the intermediate hepatocyte proliferation were observed. The notable hepatic stellate cell activation occurred around the HPCs and ductular reaction. The number of HPCs and the extent of ductular reaction increased significantly as the portal inflammation increased. There were significant correlations between the number of HPCs with the number of intermediate hepatocytes. In addition, there was a strong correlation between the ALT and AST with the number of HPCs and intermediate hepatocytes. CONCLUSION: Human hepatic progenitor cell activation exists in human liver cirrhosis. The inflammation is a trigger for HPCs activation. HPCs migration from the portal area to liver parenchyma and their differentiation into hepatocytes are important pathways for liver regeneration.

Adolescent↗
PubMed2006

[Soil carbohydrates: their determination methods and indication functions].

Soil carbohydrates are the important component of soil organic matter, and play an important role in soil aggregation formation. Their hydrolysis methods involve sulfur acid (H2SO4), hydrochloric acid (HCl), and trifluoroacetic acid (TFA) hydrolysis, and their determination methods include colorimetry, gas-liquid chromatography (GLC) , high performance liquid chromatography (HPLC), and high performance anion-exchange chromatography with pulsed amperometric detection (HPAE-PAD). This paper summarized the methods of carbohydrates' hydrolysis, purification and detection, with focus on the derived methods of GLC, and briefly introduced the indication functions of carbohydrates in soil organic matter turnover.

Carbohydrates↗
PubMed2006

[Isolation, cultivation and initial identification of Nanobacteria from dental pulp stone].

OBJECTIVE: To isolate Nanobacteria from dental pulp stone and perform culturing and the identification of Nanobacteria. METHODS: Freshly collected 27 dental pulp stones were divided into nine samples. Each sample contained three dental pulp stones. All samples were used for the isolation and culture of Nanobacteria. The shape and the growth characteristics of the cultured bacteria were observed. Nanobacteria were identified by von Kossa staining, immunohistochemical staining and indirect immunofluorescence staining, double staining including Hoechst staining and von Kossa staining. RESULTS: The characteristics growth and morphology of the bacteria detected in seven samples were similar to Nanobacteria. von Kossa staining, immunohistochemical staining, indirect immunofluorescent staining were positive for Nanobacteria. In double staining method, Hoechst staining of the samples was negative for Nanobacteria, but von Kossa staining was positive. Hoechst staining of the dental pulp cells was positive. No Nanobacteria was found in the other two samples. CONCLUSIONS: The bacteria isolated from dental pulp stone in this study was similar to Nanobacteria in terms of growth rate, morphology and staining properties. These unusual properties of the bacteria may play an important role in the formation of pulp stone.

Bacteria↗
PubMed2006

[Identification of serum biomarkers for ovarian cancer using protein chips and time of flight mass spectrometry technology].

OBJECTIVE: To screen relatively specific biomarkers in serum of ovarian cancer patients using surface-enhanced laser desorption and ionization time of flight mass spectrometry and protein chip technology. METHODS: Serum samples from 99 ovarian cancer patients, 87 healthy volunteers and 21 patients with other ovarian diseases were analyzed using metal affinity chromatography protein chip IMAC3 and cation exchange protein chip WCX2, which can specifically bind the metal-combining-proteins. Proteomic spectra were generated by mass spectrometry. The peaks were detected and filtrated by Ciphergen proteinchip software 3.2.0. Using the Biomarker Pattern 5.0 software, a diagnostic system was developed for separating ovarian cancer from the healthy group. RESULTS: Thirty-one protein peaks were significantly different between ovarian cancer patients and healthy controls (P < 0.05). A diagnostic model consisting of protein peaks from IMAC3 and WCX2 was established. Large scale blind test generated a sensitivity of 100% and specificity of 98% respectively. A differentially expressed protein with a mass-to-charge rate of 7769 was identified as potential biomarkers to distinguish ovarian cancer from other ovarian diseases. CONCLUSIONS: Time of flight mass spectrometry is a useful tool for the detection and identification of new protein markers in serum. It will provide a highly accurate and innovative approach for the diagnosis of ovarian cancer.

Adult↗