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Biomedical subjects

Hui Zhang

Publications and source records attributed to Hui Zhang.

At least 217 records · Page 12Linked to original sources
PubMed2005

Small molecule tgf-beta mimetics as potential neuroprotective factors.

Neurodegenerative and dementing illnesses are becoming an increasing social and economical burden as the number of older people continues to grow in industrialized countries. Current knowledge of the processes leading to these diseases is still limited, and very few effective treatments are available. Because neurodegeneration is associated with an activation of injury and innate immune responses in the brain, drugs that could mimic the beneficial aspects of this response are potential therapeutic candidates. The cytokine transforming growth factor (TGF)-beta1 is an organizer of the brain's response to injury and is known to be neuroprotective. Previous studies from our lab also showed that TGF-beta1 can reduce accumulation of beta-amyloid peptide (Abeta), which appears to be central to Alzheimer's disease (AD) pathogenesis, and we therefore initiated a search for small molecule chemical compounds that could mimic this effect. We report here the identification of several such TGF-beta mimetics detected in an in vitro screen of a library with 5000 chemically diverse compounds. If active in vivo, these mimetics could be developed into candidates for the treatment of neurodegeneration.

Alzheimer Disease↗
PubMed2005

[Mapping of regulatory domain of T-protein from Escherichia coli].

OBJECTIVE: To map the regulatory domain of Escherichia coli T-protein. METHODS: Fragmentation cloning was employed in cloning of 11 fragments from T-protein. The regulatory activity of each fragment was determined respectively. RESULTS: The regulatory domain of T-protein was located in the C-terminal 270 amino acids, which was the same location as PDH domain. CONCLUSION: T-protein has no independent regulatory domain.

Cloning, Molecular↗
PubMed2005

[Different expression of chaperone interacting protein in normal, scar and chronic ulcer tissues and its relationship with wound healing].

OBJECTIVE: To explore the expression characteristics of chaperone interacting protein (CHIP) in normal, scar and chronic ulcer tissues and its relationship with wound healing. METHODS: Twenty biopsies including scar tissues (n = 8), chronic ulcer tissues (n = 4) and normal tissues (n = 8) were used in this study. The immunohistochemical staining (power vision two-step histo-staining reagent) was used to explore the amount and expression characteristics of such protein. RESULTS: The positive expression of CHIP was observed in fibroblasts, endothelial cells and epidermal cells in dermis and epidermis. It was not seen in inflammatory cells. The expression amount of CHIP in scar tissues, chronic ulcer tissues and normal tissues was 89%, 83% and 17% respectively. CONCLUSION: Although the function of CHIP is not fully understood at present, the fact that this protein is expressed only at the mitogenic cells indicates that it may be involved in mitogenic regulation during wound healing.

Chronic Disease↗
PubMed2005

[Malignant transformation of NIH3T3 cells induced by ectopic expression of PC-1 gene].

OBJECTIVE: To establish a mouse fibroblastic cell line stably transfected with PC-1 gene, and using such cell line to investigate tumor development and progression imposed by the ectopic expression of PC-1 gene. METHODS: Eukaryotic expression vector pcDNA3.1(-)/myc-his-pc-1 was transfected into mouse fibroblast cell line NIH3T3 by lipofectamine. Stable transfectants were selected by G418. The integration and expression of ectopic PC-1 gene were analyzed by PCR and RT-PCR. Cytomorphological analysis, MTT, soft agar colony formation and nude mice tumorigenesis assay were used to evaluate the effects of PC-1 gene expression on tumor development and progression. RESULTS: NIH 3T3 cell lines stably expressing PC-1 gene were successfully established and confirmed by PCR and RT-PCR analyses of the integration and expression of ectopic PC-1 gene. Comparing with the parental cell line and cells transfected with control vector, the PC-1 gene transfectants acquired several phenotypes of transformed cells: increasing growth rate, ability to grow and form cell colonies on soft agar, and becoming tumorigenic in nude mice. CONCLUSION: Ectopic expression of PC-1 gene in NIH3T3 cells can induce malignant transformation of mouse fibroblastic cells both in vitro and in vivo.

Animals↗
PubMed2005

[Screening of TACE peptide inhibitors from a phage display random 15-peptide library by recombinant TACE ecotodomain].

Tumour necrosis factor-alpha converting enzyme (TACE) is the major protease responsible for processing proTNF from membrane-anchored precursor into secreted TNF-alpha. It was validated that TACE is involved in many diseases such as arthritis, multiple sclerosis and Alzheimers, therefore it represents a novel and significant target for therapeutic intervention in a variety of inflammatory and neuroimmunological diseases. To obtain the recombinant TACE ectodomain and use it as a selective molecule for the screening of TACE peptide inhibitors, the cDNA coded for catalytic domain (T800) and full-length ectodomain (T1300) of TACE were amplified by RT-PCR, the expression plasmid was constructed by inserting T800/T1300 into plasmid pET-28a/pET-28c and transformed into E. coli BL21 (DE3). SDS-PAGE and Western blotting analysis revealed that T800/T1300 was highly expressed in the form of inclusion body being induced by IPTG. After Ni2+ -NTA resin affinity chromatography, the purity of the recombinant T800/T1300 protein was more than 90%. T800 and T1300 protein were used in the screening of TACE-binding peptides from the phage display random 15-peptide library. After four rounds of biopanning, the positive phage clones were analyzed by ELISA, competitive inhibition assay and DNA sequencing. A common amino acid sequence-TRWLVYFSRPYLVAT was found and synthesized. The synthetic peptide was shown to bind to TACE and inhibit the TNF-alpha release from LPS-stimulated human peripheral blood mononuclear cells (PBMC) up to 60.3%. FACS analysis revealed that the peptide mediated the accumulation of TNF-alpha on LPS-stimulated PBMC surface. These results demonstrate that the TACE-binding peptide is an effective antagonist of TACE and the deduced motif might be applied to molecular design of anti-inflammation drugs.

ADAM Proteins↗
PubMed2005

[Correlation of plasma endothelin and multiple organ dysfunction syndrome caused by acute paraquat poisoning].

OBJECTIVE: To investigate the relationship between endothelin (ET) and multiple organ dysfunction syndrome (MODS) caused by acute paraquat poisoning (APP). METHODS: The levels of plasma ET were measured by radioimmunoassay in 24 patients with MODS caused by APP and 19 healthy persons as controls. The levels of plasma ET patients in MODS caused by APP were correlatively analysed with acute physiology and chronic health evaluation II (APACHE II) score, partial pressure of oxygen in artery (PaO2), troponin I (cTnI) level, blood enzymology and biochemistry indexes. RESULTS: The levels of plasma ET in patients with MODS caused by APP were much higher than controls (P<0.01), the level of plasma ET in death group was much higher than that of survivor group (P<0.01). Plasma ET was positively correlated with APACHE II score, cTnI, MB isoenzyme of creatine kinase (CK-MB), lactate dehydrogenase (LDH), alanine aminotransferase (ALT), aspartate aminotransferase (AST), blood urea nitrogen (BUN) and serum creatinine (SCr, P<0.05 or P<0.01), where there was a negative correlation with PaO2 (P<0.01). CONCLUSION: Endothelin may be involved in the pathogenesis of MODS caused by APP, plasma ET may be one of a clinical index for evaluating the degree of multiple organ function damage, for guiding treatment, and judging the prognosis of MODS caused by APP.

APACHE↗
PubMed2005

[The expressions of cyclooxygenase-2 (Cox-2),VEGF in oral squamous cell carcinoma and precancerous lesions and their significances].

PURPOSE: To determine expression of Cox-2 in oral squamous cell carcinoma (SCC) and oral leukoplakia and the relation to VEGF. METHODS: Immunohistochemical staining was used to quantify Cox-2 and VEGF expressions in specimens from 48 patients with oral SCC (including 20 well differentiated cases, 16 moderately differentiated cases and 12 low differentiated cases), 35 patients with oral leukoplakia (epithelial dysplasia), and 20 patients with normal oral mucosa. All specimens were analyzed by conformation quantitative assay system, their stain-strength was calculated. Statistical analysis of ANOVA and linear correlation was performed using SAS statistical software. RESULTS: The expressions of Cox-2 and VEGF increased significantly as the progression of oral mucosa from normal to oral leukoplakia and oral SCC. The expression of Cox-2 reached peak in well differentiated SCC (0.167+/-0.004), and its expression decreased sharply as differentiation became poor. On the other hand, the expression of VEGF reached peak in well differentiated carcinoma (0.143+/-0.014). The expressions of Cox-2 and VEGF had negative correlation in differently differentiated SCC tissues (r=0.649, P<0.001). CONCLUSION: The expressions of Cox-2 and VEGF were significantly up-regulated in the early carcinogenesis of oral mucosa, and they may be influenced each other. Thus, they were important in the carcinogenesis and progression of oral SCC.

Aged↗
PubMed2005

[Impact of PC-1 gene knockdown on the biological action of prostate cancer cell line C4-2].

OBJECTIVE: To study the effect of PC-1 gene knockdown on the biological action of prostate cancer cell line C4-2. METHODS: Recombinant plasmids of expressing short hairpin RNA targeting PC-1 mRNA were constructed using DNA recombinant technology and transfected into C4-2 cells via liposome. The positive cell clones were selected by G418. The expression of PC-1 gene was analyzed by RT-PCR and Western blotting technology. MTT and soft agar cloning formation were applied to observe the changes of the growth rate and independent anchor ability of C4-2 cells. RESULTS: PC-1 RNA interference severely affected the expression of PC-1 gene and reduced the growth and colony formation ability of C4-2 cells. CONCLUSION: RNA interference-mediated PC-1 gene knockdown can decrease the growth and cloning formation ability of C4-2 cells.

Cell Line, Tumor↗
PubMed2005

[Research on the pharmacokinetics and pharmacodynamics of L-asparaginase during its treatment of childhood acute lymphoblastic leukemia].

OBJECTIVE: To investigate the changes in the activity of Escherichia coli asparaginase (L-asp) and the concentration of asparagines (ASN) in the plasma of the acute lymphoblastic leukemia (ALL) children receiving L-asp containing chemotherapeutic protocol to explore more reasonable usage of L-asp in the treatment of childhood ALL. METHODS: L-asp containing hemotherapy regimen of VDLP was used, in which L-asp (10,000 U/m(2)) was administered intravenously every other day for 10 doses in 15 children with ALL. A total of 340 peripheral blood samples were collected at scheduled time points during the therapy and plasma L-asp activity (by spectrophotometric assay) and asparagines concentration (by RP-HPLC) were measured. RESULTS: During the administration of L-asp, the plasma L-asp activity was increasing gradually peaked after eight doses and then decreased gradually, while the plasma concentration of asparagines maintained in complete or nearly complete depletion status. After the therapy courses finished, a plasma L-asp activity above 100 U/L with asparagines almost complete depletion status was lasting for about seven days. CONCLUSION: The current L-asp containing chemotherapeutic protocols in which L-asp was administered in a dose of 10 000/m(2) intravenously every other day, are efficient enough for the depletion of plasma ASN.

Adolescent↗
PubMed2005

[Inhibitory effect of 4-1BBL combined with Hsp70-tumor antigen peptides on pulmonary metastasis of melanoma in mice].

BACKGROUND & OBJECTIVE: Low level expression of some co-stimulatory molecules is an important mechanism for tumor to evade the attack of immunity system; up-regulating these molecules can enhance antitumor immune response. Mouse melanoma B16-F1 cell line is low immunogenic. This study was designed to investigate the inhibitory effect of co-stimulatory molecule 4-1BBL combined with hot shock protein 70 (Hsp70)-tumor antigen peptides on pulmonary metastasis of melanoma in mice, and to analyze the possible mechanism. METHODS: After establishment of B16-F1 melanoma pulmonary metastasis model, the mice were divided into combination (4-1BBL plus Hsp70-B16) group, 4-1BBL group, Hsp70-B16-F1 group, empty vector group, and normal saline(NS) group, and relevantly received subcutaneous immunization of Hsp70-B16 peptides complex and simultaneous injection of plasmid p4-1BBL via the tail vein. Seventeen days after inoculation of B16 cells, the mice were killed to count pulmonary metastasis nodes under microscope, and to detect a series of immunologic parameters, liver function, and kidney function. RESULTS: The number of pulmonary metastasis nodes was significantly smaller in combination group than in 4-1BBL group and Hsp70-B16 group (50+/-8 vs. 500+/-80 and 450+/-40, P0.01); the levels of interleukin-2 (IL-2) and interferon-gamma (IFN-gamma) in serum were significantly higher in combination group than in NS group (200.31+/-25.36 vs. 56.89+/-16.55, P0.05; 1 870.53+/-204.28 vs. 610.30+/-120.05, P0.01). The liver and kidney functions of mice in each group are normal. CONCLUSION: 4-1BBL in combination with Hsp70-B16 peptides can effectively inhibit melanoma pulmonary metastasis mainly through augmenting the function of peripheral T lymphocytes.

4-1BB Ligand↗
PubMed2005

[An experimental study on the mini pig model of obstructive sleep apnea syndrome].

A mini pig model for study of human obstructive sleep apnea syndrome (OSAS) was established by altitude hypoxia. Eight mini pigs were randomly assigned to 3 groups, named A, B, and C. They were placed in a double-roomed altitude chamber. As control, Groups A lived in Room 2 and there was an altitude of sea level in it. Groups B and C were in Room 1 and the pressure in it was 53.9 KPa with an oxygen concentration of 10.0%-11.2%. All of these mini pigs were in their rooms for 6 hours per day. Pigs in Groups B were in the room for 12 consecutive days and sacrificed on the 13th day. Pigs in Groups A and C were executed on the 23rd day. The pharyngeal CT scanning and the defermination of respiratory pressure in pharynx oralis and saturation of arterial blood oxygen were conducted in all exprimental mini pigs before they were put in chamber and before they were put to death. The pharyngeal tissues of the executed pigs were pathologically examined. CT scanning revealed there was significant (P < 0.05) increase in mini pigs' posterior pharyngeal wall (8.8 +/- 1.1 vs 6.5 +/- 0.6) and lateral pharyngeal wall (8.1 +/- 0.2 vs 6.3 +/- 0.6) on the 13th day as compared with that before they were put in chamber, and there was also significant (P < 0.05) increase (9.2 +/- 1.2 vs 6.3 +/- 0.7; 8.9 +/- 0.7 vs 6.4 +/- 0.5) on the 23rd day. There was significant (P < 0.05) reduction in diameter from left to right at the hyoid bone level (7.6 +/- 1.4 vs 9.7 +/- 1.4) and in the anteroposterior diameter at the soft palace level (3.8+/-1.1 vs 6.5 +/- 1.3) on the 13th day as compared with that before the mini pigs were put in chamber, and there was also sinificant (P < 0.05) reduction (6.4 +/- 1.6 vs 9.3 +/- 1.5; 4.3 +/- 0.9 vs 5.9 +/- 0.8) on the 23rd day. There was significant reduction (P < 0.05) in anteroposterior diameter on the posterior area of hyoid bone (3.7 +/- 0.9 vs 6.4 +/- 0.6) on the 23rd day. A significant change (P < 0.05) was observed in respiratory pressure of pharynx oralis on the 23rd day (0.0755 Mv) when compared with that before the first day (0.0658 Mv) in chamber and no significant change was seen on the 13th day. The saturation of blood oxygen decreased from 96.3% to 87.0% on the 13th day (P < 0.05) and further descended to 88.5% on the 23rd day (P < 0.05), compared with that before the first day in chamber. Pathological examination showed. In Group A, the mucosa of pharynx is covered by nonkeratinized-stratified squamous epithelium, and the layer of submucosa is thin; the muscular layer has clear striations and less fat cells among muscular fibers. In Group B, the pharyngeal epithelium is cornified and proliferated. Edema and proliferation of connective tissue occur in submucosa, and the muscular layer is thick with unclear striations; local infiltration of fat cells can be observed among muscular fibers. The pathological changes were more serious in Group C than in Group B. The results suggest that the method of intermittent altitude hypoxia could make the pharyngeal tissue of mini pig remodel and change its muscular biomechanical properties into those similar to the performance of OSAS in human. Living in altitude hypoxia for 22 days, the mini pigs became ill with OSAS, thus the expected animal model has been established in this study and could be used in further researches on OSAS in patients.

Altitude↗
PubMed2005

[Effect of shenqi fuzheng injection on pre/post-operational change of argyrophilic-nucleolar organizer regions in peripheral T-lymphocyte in patients with gastric carcinoma].

OBJECTIVE: To investigate the pre-post operational change of argyrophilic-nucleolar organizer regions (Ag-NORs) in peripheral T-lymphocyte of patients with gastric carcinoma (GC), and to explore the effect of shenqi fuzheng injection(SFI) on it. METHODS: Eighty five patients were divided into two groups according to the operation performed was radical or non-radical, and the two groups were subdivided into two by additional intravenous dripping of SFI was given to them or not. The content of Ag-NORs in peripheral T-lymphocyte in all patients before and after operation as well as in 12 healthy subjects was determined. RESULTS: Content of Ag-NORs in GC patients was significantly lower than that in the healthy subject (P < 0.01), which significantly increased after patients underwent radical operation (P < 0. 01 or P < 0.05), especially in those treated with SFI (P < 0.01). While in patients underwent non-radical operation but not treated with SFI, it showed insignificant change after operation, however it did significantly increase in those treated with SFI (P < 0.05). CONCLUSION: The immune function of T lymphocyte was low in patients with gastric carcinoma, post-operational adjuvant treatment of SFI can significantly improve the cellular immunity of patients.

Adjuvants, Immunologic↗
PubMed2005

[Studies on the hyperfine structures of I2 absorption line with third harmonic frequency stabilization in Nd:YVO4-KTP ring laser].

The experiment for research on the hyperfine structure of I2 absorption lines with third harmonic frequency stabilization in Nd: YVO4-KTP ring laser has been done. The hyperfine structures of two lines have been observed and the results are comparable with the theoretical calculations. One of the two lines is R(70) 36-1 is the transition of the excited state.

Algorithms↗
PubMed2005

[Effect of PC-1 gene expression on migration ability of prostate cancer cells].

BACKGROUND & OBJECTIVE: PC-1 gene is highly expressed in C4-2 cell line, an androgen-independent and aggressive prostate cancer cell line, but lowly expressed in LNCaP cell line, an androgen-dependent prostate cancer cell line. This study was to assess the contribution of PC-1 gene to migration of prostate cancer cells. METHODS: LNCaP cell line with stable expression of PC-1 gene and C4-2 cell line with antisense nucleotide-down-regulated PC-1 were established. The migration abilities of LNCaP and C4-2 cells were tested using an in vitro transwell invasion assay. RESULTS: Migration cell count of LNCaP cells with up-regulation of PC-1 gene was similar to that of control LNCaP cells(P>0.05); migration cell count was significantly lower in C4-2 cells with down-regulation of endogenous PC-1 gene than in control C4-2 cells (P<0.05). CONCLUSION: PC-1 may be involved in the invasion of prostate cancer cells.

Cell Movement↗
PubMed2005

Radiographic and clinical analysis of cementless acetabular fixation in total hip arthroplasty.

OBJECTIVE: To investigate the factors affecting the fixation, loosening and therapeutic effect of cementless acetabular prosthesis through following up the patients with total hip arthroplasty clinically and radiographically. METHODS: From February 1998 to May 1999, 139 patients (148 hips) underwent total hip arthroplasty with cementless acetabular prosthesis in our department. In this study, the clinical therapeutic effect and the anteroposterior radiographs of the pelvis and anteroposterior and lateral radiographs of the hips of 109 patients (116 hips) made before operation, at 1 week, 3, 6, and 12 months after operation and annually thereafter were analyzed retrospectively. The clinical therapeutic effects were evaluated with Harris hip score. Radiographs were used to observe the position of prostheses and the bone changes around the implant, and to measure the wearing speed and direction of the acetabular cup. All evaluations were made by an independent examiner who did not participate in the operation. The patients were followed up for 5-6 years. RESULTS: The mean Harris score was 44 points (range, 10-70 points) before operation, but it increased to 92.4 points (range, 80-100 points) at the latest review after operation, which was significantly higher than that before operation (P<0.05). No acetabular component was revised because of infection or aseptic loosening. And no acetabular component migrated. There was no revision of fixed acetabular component because of pelvic osteolysis secondary to polyethylene wear. The mean linear wear rate was 0.15 mm per year. All the acetabular prostheses were classified as stable on the radiographs. CONCLUSIONS: In terms of fixation, total hip arthroplasty with cementless acetabular components was successful. Although there is no aseptic loosening and a low incidence of osteolysis at the latest follow-up evaluation, polyethylene wear cannot be avoided and can lead to expansile osteolysis near the cups. This kind of osteolysis usually had no obvious clinical symptoms but it can be diagnosed early on radiographs. So radiographical follow-up for cementless acetabular components is very important.

Acetabulum↗
PubMed2005

[Studies on the spectrum and frequency repetition of double-mode He-Ne laser with frequency stabilization].

Theoretical analysis of spectrum and frequency repetition of the double-model frequency stabilization He-Ne laser has been done, and the beat frequency experiment using 632 nm I2 frequency stabilization He-Ne laser has been carried out. The authors used the intercavity laser, and the double mode frequency stabilization to get the laser stabilized output through adjusting the two neighbor vertically polarized modes to the equal power reference point. Through the experiment, the authors analyzed the factors which affect the laser frequency repetition and stabilization, and measured the stabilized laser power and the frequency stabilization. The beat frequency experiment has shown that the frequency repetition can reach (1-2) x 10(-8) by frequency difference, and the laser stabilization can reach 10(-10) by Allan variances. The experiments show that the stabilized laser can work well and can be used as frequency reference point.

Algorithms↗