Biomedical subjects

Hui Zhang

Publications and source records attributed to Hui Zhang.

At least 127 records · Page 7Linked to original sources

PubMed2006

[Transferring the Suaeda salsa glutathione S-transferase and catalase genes enhances low temperature stress resistance in transgenic rice seedlings].

The GST (glutathione S-transferase) and GST+CAT1 (catalase 1) of Suaeda salsa were introduced into a low temperature-sensitive rice cultivar (Oryza sativa cv. Zhonghua No.11) by Agrobacterium tumefaciens-mediated transformation under the control of cauliflower mosaic virus (CaMV) 35S promoter, and the transformed calli and plantlets were screened on Murashige and Skoog (1962) medium supplemented with hygromycin 25 microg/mL and cefotaxime 300 microg/mL. The putative primary transformants (T(0) generation) were acclimatized at 26 degrees C /22 degrees C in a greenhouse for 7 d, and then transplanted to the field, where they grew up to maturity under outdoor conditions. 25 and 14 independent transgenic lines of T(1) generation carrying the GST and GST+CAT1 genes, respectively, were identified by PCR amplification. Transgene expression was monitored by RNA-blot hybridization using total RNA samples from leaf tissues. To investigate whether expressing the Suaeda salsa GST and GST+CAT1 in transgenic rice increased low temperature stress tolerance, the T(4) 14-day-old transgenic and non-transgenic rice seedlings were transferred to a low temperature (day 7 degrees C/night 4 degrees C) growth chamber for 3-6 d. The experimental data showed that expressing the Suaeda salsa GST and GST+CAT1 enhanced low temperature stress resistance in transgenic rice seedlings. When treated with low temperature, both GST and CAT activity increased in the transformants with the time of temperature treatment. These transgenic rice plant seedlings exhibited a higher level of photosynthetic capacity than those of the non-transgenic control seedlings under low temperature treatment. Whereas, there were lower H(2)O(2) and MDA (malondialdehyde) content, and relative electrolyte leakage through the plasma membrane was also lower in transgenic rice seedlings than in the parent line under low temperature condition. The results also indicated that GST+CAT1 co-expression conferred greater level of low temperature stress tolerance to the transformed rice plants compared to the single GST transformed plants.

Acclimatization↗

PubMed2006

[Efficacy of 188Re-herceptin radioimmunotherapy in nude mouse model of nasopharyngeal carcinoma].

OBJECTIVE: To evaluate the effect of radioimmunotherapy with (188)Re-labeled herceptin in nude mice bearing nasopharyngeal carcinoma expressing HER2/neu proto-oncogene and explore the feasibility of (188)Re-herceptin for use as a chemical therapeutic and radioimmunotherapeutic agent. METHODS: A direct radiolabeling method was used to prepare (188)Re-Herceptin. Thirty-two nude mice bearing nasopharyngeal carcinoma were randomized into 4 groups (n=8) to receive single intravenous injection of (188)Re-Herceptin, intratumoral injection of (188)Re-Herceptin, (188)Re-nmIgG and (188)Re, respectively, all at the equivalent dose of 11.1 MBq (50 microl). Another 5 tumor-bearing mice received only intratumoral injection of 50 microl normal saline to serve as the control group. Two days after the injections, 3 mice were selected from each group (except for the control group) for biodistribution observation, and the rest mice were monitored for 4 consecutive weeks for tumor volume changes. Pathological examination of the tumor tissues was also performed. RESULTS: The radioactivity uptake in the tumor was significantly greater whereas normal organ uptake significantly lower in the nude mice receiving intratumoral (188)Re-Herceptin injection than in those with intravenous (188)Re-Herceptin injection (11.53%ID/g vs 2.79%ID/g at 48 h). Intratumoral (188)Re-Herceptin injection caused greater inhibition of tumor growth at the 4th week as compared to the intravenous administration. CONCLUSION: Intratumoral (188)Re-Herceptin administration can significantly inhibit the development of nasopharyngeal carcinoma in mice, and may potentially serve as a new clinical option of regional therapy for treating nasopharyngeal carcinoma overexpressing HER2/neu.

Animals↗

PubMed2006

Computer-assisted auto-frame navigation system for distal locking of tibial intramedullary nails: a preliminary report on clinical application.

OBJECTIVE: To evaluate the clinical feasibility and effect of the computer-assisted auto-frame navigation system for distal locking of tibial intramedullary nails. METHODS: The hardware components of the system included a PC computer with a monitor, auto mechanical stereotactical localization cubic frame, foot holder and localization operative apparatus. Special navigation software can be used for registration of X-ray fluoroscopic images and real-time controlling navigation of tools. Twenty-one cases of close tibial and fibular fractures were treated with closed intramedullary nailing, 6 of which involved in middle third, 12 in middle and lower third, 3 in lower third. C-arm alignment and registration time, fluoroscopic time and drilling time involved in the locking procedure were recorded. The size of unreamed or reamed tibial nails ranged from 8/300-11/330. RESULTS: All distal holes except 1 were locked successfully. In 9 of 41 locked holes (21.95%), the drill bit touched the canal of locking hole without damage of the nail and clinical consequences. The fluoroscopy time per pair of screws was 2.23+/-0.31 s. CONCLUSIONS: The computer-assisted auto-frame navigation system for distal locking is well designed, easy to operate and do not need additional instruments during the procedure. The developed system enables the physician to precisely navigate surgical instruments throughout the anatomy using just a few computer-calibrated radiographic images. The total time of X-ray exposure per procedure can be significantly reduced.

Adult↗

PubMed2006

[Preliminary study on the safety and pharmacodynamic action of low dose L-asparaginase].

OBJECTIVE: To investigate the safety and therapeutic effect of low dose (1000 U/m(2)) L-asparaginase (L-Asp) in the treatment of children with acute lymphoblastic leukemia (ALL). METHODS: Six patients were treated with low dose L-Asp after previously suffered severe side effects from standard dose L-Asp (5000 - 10,000 U/m(2)). Twenty-eight blood samples were obtained randomly from 5 of them. Plasma asparagine concentration was detected by reverse phase-high performance liquid chromatography (RP-HPLC). RESULTS: All the patients treated with low dose L-Asp showed no any toxic symptoms. The plasma asparagine levels in the patients were all above 5 micromol/L except case 4 (4.91 micromol/L) before receiving L-Asp, and were all decreased below 0.5 micromol/L five days after receiving low dose L-Asp, except case 3 (3.70 micromol/L), the results being like that of receiving standard dose L-Asp. CONCLUSION: Low dose L-Asp has definite efficacy for childhood ALL, while avoids serious side effects from standard dose L-Asp.

Adolescent↗

PubMed2006

[Evaluation of the ultrasonographic features of axillary lymph node metastasis in breast cancer].

OBJECTIVE: To analyze the ultrasonographic features of axillary lymph node metastasis in breast cancer patients, and to evaluate the accuracy of these features by Receiver Operating Characteristic (ROC) curve. METHODS: Ultrasonography was carried out in 113 patients (mean age 56.5 yr, range 29 - 77 yr). The ultrasonographic features of the primary tumor and the axillary lymph node were observed. Univariate analysis was performed by Chi-squared test and Fisher exact test, and multivariate analysis to determine independent significant individual variables by multiple logistic regression analysis. ROC curve analysis was done to determine the sensitivity and specificity of individual and combined ultrasonographic features in distinguishing metastatic lymph node from the normal one. RESULTS: The primary tumor size, abundance of blood supply in the primary tumor, longitudinal-transverse diameter ratio, cortex-hilum thickness ratio (on the longitudinal section), abnormal cortex thickness, distribution of intra-nodal vascularity of axillary lymph nodes were found to be statistically significant factors by univariate analysis. The primary tumor size, longitudinal-transverse ratio and cortex-hilum thickness ratio of lymph node were proved to be significant independent predictors of axillary lymph node metastasis by logistic regression analysis. Through ROC analysis, the combination of these independent ultrasonographic feature predictors was found to contribute significantly in differentiating metastatic lymph node from the normal with a sensitivity of 88.6% and specificity of 84.5%. CONCLUSION: Axillary ultrasonography is helpful in staging the axillary lymph node in breast cancer patient. The primary tumor size, longitudinal-transverse diameter ratio and cortex-hilum thickness ratio of lymph node are the main features to determine whether metastatic involvement is present or not.

Adult↗

PubMed2006

[The study of 11 cases of chordoma in the skull base or neck].

OBJECTIVE: To study the clinical manifestation, histopathological types, radiological characteristics, surgical methods and the prospective efficacy of chordoma in the skull base and neck. METHOD: Analyzed the characteristics about eleven patients with chordoma in the skull base or neck that we had treated in our department from 1985 to 2003 and introduced a case of a huge chordoma in the neck. All of the patients were treated by surgery. RESULT: The clinical manifestations of chordoma in the neck or skull base were complex. The first symptoms included the mass in the neck, rhinocleisis, visuognosis fall, tinnitus, hearing loss, and damages of brain nerves. Eight cases were the typical chordoma and the other three were the cartilaginiform chordoma. The dilatant image of parenchyma was the feature in CT scan and the images often had clear confines. The cervical vertebra and the skull base were damaged in the most of the cases. Four patients (4/11) recrudesced in two years after the surgery, and eight of eleven were living more than five years after the surgery. CONCLUSION: The clinical manifestations of chordoma in the neck or skull base were complex. The cervical vertebra and the skull base were often damaged in the most of the cases. Surgery is an effective method on chordoma. The surgery path should be selected according

Adult↗

PubMed2006

[Properties and advance of hepcidin].

Hepcidin is a small cystein-rich cationic peptide produced mainly by the liver. It was initially isolated from human plasma and exhibited antimicrobial activity. Recently, several lines of evidence have suggested that hepcidin is a key regulator of iron metabolism at the whole body level and is relative to inflammation, infection, hypoxia and anemia. Hepcidin, is implicated in duodenal iron absorption and iron mobilization from reticuloendothelial macrophages. The major mechanism of hepcidin function seems to be the regulation of transmembrane iron transport. As both iron deficiency and iron excess are associated with cellular dysfunction, so hepcidin or hepcidin-related therapeutics could find a place in the treatment of various diseases such as hemochromatosis and anemia of chronic disease. To elucidate biological function of hepcidin further and use it for other research, it is necessary to produce enough hepcidin through DNA recombinant technique. As a highly successful system for the production of a variety of heterologous proteins, the methylotrophic Pichia pastoris system has the probability for a high level production of hepcidin. The subject of this paper is to summarize the regulation of hepcidin gene expression and the understanding of functions of hepcidin. At last, giving a prospect of production hepcidin by gene engineer.

Antimicrobial Cationic Peptides↗

PubMed2006

[Non-alcoholic steatohepatitis : pathology and pathogenesis].

Nonalcoholic steatohepatitis (NASH) has become to be widely recognized as a significant cause of chronic liver injuries. Evidences suggest that development of NASH requires a double "hit". The "first hit" involves the accumulation of fat in the liver, and the "second hit" includes oxidative stress, cytokines, stellate cell activation, and fibrogenesis. Microscopically, some alcoholic hepatitis-like findings, hepatocellular steatosis, ballooning degeneration, Mallory body, acute and chronic lobular inflammation, and zone 3 perisinusoidal fibrosis are noted. Because ballooning degeneration and Mallory body denote progressive NASH, we should identify clearly these findings. The diagnosis of nonalcoholic steatohepatitis requires histopathologic evaluation, because the lesions of parenchymal injury and fibrosis cannot be detected by imaging studies or laboratory tests.

Adaptor Proteins, Signal Transducing↗

PubMed2006

[Genotype of wild-type measles viruses circulating in Beijing in 2003].

OBJECTIVE: To investigate genotype of wild-type measles viruses circulated in Beijing in 2003. METHODS: Throat swabs specimens were collected from patients seen during an outbreak of measles and from clinically suspected sporadic measles patients in 2003. Vero/SLAM cell lines recommended by WHO were used to isolate measles virus. Four hundreds and fifty nucleotides of COOH-terminal of nucleoprotein (N) genes were amplified by using PR-PCR. The amplified products were sequenced and the sequences were compared with references viruses from GeneBank. RESULTS: Eight strains of measles viruses were isolated from throat swabs of patients who came from seven districts and counties of Beijing. Sequence analysis of the 450 nucleotides of COOH-terminal of nucleoprotein (N) genes indicated that these 8 strains belonged to H1a genotype. The average genetic distances of these 8 strains to H1a genotype, Chin9322, H1b genotype, Chin9475 and H1c genotype, Chin9427, were 0.004 - 0.011, 0.026 - 0.031 and 0.015 - 0.022, respectively. The average genetic distances of these 8 strains to H1a genotype, Anhui 01 - 1/Anhui 02 - 2, were 0.000 - 0.009 (0 - 5 nucleotide variation). CONCLUSIONS: Major genotypes of wild-type measles viruses circulated in Beijing in 2003 were H1a genotype. The genotypes H1c, H1b and H2 may have disappeared in Beijing.

Child↗

PubMed2006

Protective effect of isoflurane and sevoflurane on ischemic neurons and expression of Bcl-2 and ICE genes in rat brain.

OBJECTIVE: To study the protective effect of volatile anesthetics, isoflurane and sevoflurane, on ischemic neurons after cerebral ischemia-reperfusion in rats and its possible molecular mechanism. METHODS: Rat cerebral ischemia-reperfusion model was developed by occlusion of the middle cerebral artery (MCA) and bilateral common carotid arteries (CCAs) 1 h after reperfusion. Using flow cytometry (FCM) and Northern blot hybridization, we calculated the number of apoptotic bodies and detected the expression of bcl-2 mRNA and interleukin-1beta converting enzyme (ICE) mRNA. RESULTS: The apoptotic bodies in hippocampus analyzed by FCM peaked at appeared 24 h after reperfusion, and decreased about 54% and 40%, respectively, after treatment with isoflurane and sevoflurane, as compared with ischemic group. There was no significant difference in the expression of bcl-2 mRNA and ICE mRNA between the inhaled anesthetic groups and ischemic group in hippocampus 24 h after MCA/CCAs occlusion. CONCLUSION: Isoflurane and sevoflurane partially inhibit apoptosis but have no significant effect on the expression of bcl-2 and ICE genes.

Anesthetics, Inhalation↗

PubMed2006

[Study on the CD and ORD of the crystal NaClO3].

Chiral isotropy material should be obtained in order to manufacture chiral optical waveguide. In the present paper, a chiral crystal of NaClO3 was grown from water solution by standard rocking techniques. Crystal incising and optical polishing were doneand a transparent 10.9 mm x 8.2 mm x 4.7 mm crystal NaClO3 was obtained. Along the six directions perpendicular to the surface of the crystal NaClO3, its circular dichroism and UV spectra were collected, and at the same time its optical rotatory dispersion was measured by a self-fabricated ORD apparatus. It was approved by our experiment that the CD, UV spectrum and the optical rotatory dispersion of the crystal NaClO were isotropic, which is not the same as those of quartz.

English Abstract↗

PubMed2006

[Optimization preparation of chansu-loaded solid lipid nanoparticles by central composite design and response surface method].

OBJECTIVE: To optimize the formulation of chansu-loaded solid lipid nanoparticles (Cs-SLN). METHOD: Cs-SLN was prepared by cold homogenization technique. The effects of influence factors such as the weight of compritol 888 ATO, soybean lecithin and poloxamer 188, on mean diameter, entrapment efficiency, drug loading and overall desirability were investigated by using central composite design and response surface method. The data were imitated using multi-linear equation and second-order polynomial equation. RESULT: The latter was prior to the former considering from multiple correlation coefficients. Under the optimal conditions, the mean diameter, entrapment efficiency, drug loading of the Cs-SLN were 71.5 nm, 92.45% and 5.26%. CONCLUSION: The optimized preparation technique for Cs-SLN is stable, feasible and high inclusion rate. It can be used for production of Cs-SLN.

Amphibian Venoms↗

PubMed2006

[Effect of gingerol on endotoxemia mouse model induced by heatstroke].

OBJECTIVE: To observe the effect of Gingerol on endotoxemia mouse induced by heatstroke. METHODS: Forty mice were randomly divided into five groups, the endotoxemia model group (A), the normal temperature group (B), the Gingerol treated group (C), the solvent control group (D), and the saline control group (E), 8 mice in each group. Group B to E was administered with saline, Gingerol, solvent and saline respectively. Mice in group B were placed at room temperature 25 +/- 0.5 degrees C , relative humidity 43 +/- 5 % for 2 hrs, while mice in the other groups were exposed under 35 +/- 0.5 degrees C and relative humidity 65 +/- 5 % for 2 hrs in an artificial hot-climate mimic cabin to establish heatstroke endotoxemia model. The energy metabolic level of celiomacrophage was detected with MTT; the phagocytic ability was examined with neutral red chromometry; the hepatocyte ultrastructure was observed with transmission electron microscopy, as well as the activity of superoxide dismutase (SOD) and the level of malondialdehyde (MDA) in plasma was tested. RESULTS: As compared with Group A, D and E, in Group C, energy metabolic levels of macrophage, phagocytic ability, and activity of SOD were significantly higher (P < 0.01), and the level of MDA was significantly lower respectively (P < 0.01), with the levels of SOD and MDA approaching to those in Group B (P >0.05). The pathologic changes of hepatocyte ultrastructure in group C were less than those in the other three endotoxemia groups. CONCLUSION: Gingerol could raise the energy metabolic level of celio-macrophage to enhance its phagocytic ability, increase the activity of SOD and reduce the production of MDA in mouse with heatstroke endotoxemia, so as to alleviate the liver damage.

Animals↗

PubMed2006

[Therapeutic effects of simultaneous expression of 4-1BBL and sPD-1 on experimental murine hepatoma].

OBJECTIVE: To explore the possible negative regulatory elements induced by the treatment of experimental murine hepatoma with 4-1BBL, and to investigate the synergistic effects and mechanisms of 4-1BBL and soluble PD-1 (sPD-1) in tumor therapy. METHODS: Mice were inoculated intramuscularly (i.m.) with 5 x 10(5) H22 tumor cells in the right hind thigh to establish the experimental hepatoma model. The mice were randomly divided into 5 groups (12 mice in each group) after inoculation. The mice of group A, B, C and D were injected with NS, plasmid pcDNA3.1, plasmid p4-1BBL and plasmid pPD-1A respectively. The mice in group E, the combinatorial treatment group, were injected with plasmid p4-1BBL and pPD-1A together. Then the anti-tumor effects, using the tumor growth rates and mice survival rates and others as parameters, were recorded. Meanwhile, the phenotype of lymphocytes and residual tumor cells in the peri-tumor tissue were analyzed. RESULTS: Either transfection with 4-1BBL gene alone or with sPD-1 alone could inhibit tumor growth to some extent, but a more significant anticancer effect was obtained in the combinatorial treatment group (group E), in which the tumors were completely inhibited in 42% of the mice, compared with 0 in the other groups. In addition, the survival rate of mice in group E was 100%, compared with 30% in group B, 65% in group C and 62% in group D. The FACS analysis results showed that the expression level of B7-H1 and B7-DC on residual tumor cells in group C (injected with p4-1BBL alone) was higher than that on cells in other groups. The amount of CD8+ T cells in the peri-tumor tissue of group E was significantly increased. CONCLUSION: 4-1BBl can induce an up-regulation of negative regulatory elements and at the same time it can enhance the anti-tumor response. The combinatorial treatment with 4-1BBL and sPD-1 can produce a positive synergistic anti-tumor effect on our murine experimental hepatoma.

4-1BB Ligand↗

PubMed2006

[Determination of propofol in human serum by improved reversed phase high-performance liquid chromatography with fluorescence detection].

OBJECTIVE: To develop a new high-performance liquid chromatographic (HLPC) method for determination of propofol in human serum. METHODS: Human serum samples were precipitated with 20% perchloric acid and centrifuged to obtain 50 microl of the supernatant for analysis by HPLC coupled with fluorescence detection. The analysis was performed with a C(18) reversed-phase column using a acetonitrile-water (90:10) phase delivered at 1.0 ml/min, with the excitation wavelength of 276 nm and emission wavelength of 310 nm. RESULTS: The calibration curves were linear (r=0.997 5) within the concentration range of 0.05-10 microg/ml, the limit of propofol quantification was 50 ng/ml and the intra- and inter-day precisions were between -/+15%. CONCLUSIONS: The method is accurate, sensitive and simple for propofol determination in clinical anesthesia.

Anesthetics, Intravenous↗

PubMed2006

[Identification of circulating plasmacytoid dendritic cells in chronic HBV-infected patients].

OBJECTIVE: To investigate the features of circulating plasmacytoid dendritic cells (pDCs) in patients with chronic hepatitis B for a better understanding of the immunopathogenesis of HBV infection. METHODS: Fresh blood samples were collected from 20 patients with chronic hepatitis B (CHB) and from 15 healthy individuals who served as controls. pDCs were isolated from peripheral blood mononuclear cells (PBMCs) using immunomagnetic assay and detected by flow cytometry. Fresh PBMCs and isolated pDCs were stimulated in vitro using CpG ODN2216. The supernatants were measured for IFNa production using ELISA. RESULTS: The peripheral pDCs frequency in CHB patients (0.192%+/-0.110%) was markedly lower than that in the healthy controls (0.287%+/-0.142%). After being pulsed with CpG ODN2216, the isolated pDCs produced lower levels of IFNa and expressed lower levels of CD80 and CD40 in the CHB patients when compared to those of the healthy controls. The level of IFNa was (972.6+/-705.5) pg/ml in the patients and (3 142.9+/-1 292.2) pg/ml in the controls. Moreover, the pDCs frequency was reversely correlated with serum ALT levels in these HBV infected patients. CONCLUSION: The reduced number and impaired function of circulating pDCs in patients with CHB may be related to their disease progression.

Adult↗

PubMed2006

[A study on the relativity between La protein and the stability of HBV mRNA and the expression of HBV protein].

OBJECTIVE: To study the relativity between La protein and the stability of HBV mRNA and the expression of HBV protein. METHODS: Four specific siRNAs were obtained by transcription in vitro. After transfection with the siRNAs into HepG2.2.15 cells for 3 days, the inhibitive effects of La protein were analyzed by Western blot; the content changes of HBsAg, HBeAg and HBV-DNA were detected by ECL and RT-PCR. RESULTS: In comparison to normal cells, La protein was less in the cells. There was less La protein in the cells trans-infected with siRNAs. HBsAg, the HBeAg and HBV-DNA secreted by the cells transfected with siRNA were also less than that in the normal cells. CONCLUSION: There is a correlation between La protein and HBV mRNA and the expression of HBV protein.

Autoantigens↗

PubMed2006

[The phenotype and function of CD4+ CD25+ regulatory T cells in hepatitis B patients].

OBJECTIVE: Our aim was to investigate the frequency, phenotype and function of CD4+ CD25 high regulatory T cells (Treg) in patients with acute and chronic hepatitis B (AHB, CHB). METHODS: Peripheral blood mononuclear cells (PBMCs) from 16 AHB patients at acute phase (week 1 of illness), 72 CHB patients, and 32 health subjects were analyzed for Treg frequency and CD45RO, CD45RA, CD95 and HLA-DR phenotype by flow cytometry. Intracellular expression of cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) was examined by intracellular cytokines staining. Forkhead/winged helix transcription factor (FoxP3) mRNA was detected by a real-time RT-PCR assay. The effects of MACS magnetic beads-purified Treg cells on the proliferation of PBMCs were examined by a [3H]-thymidine incorporation assay. The effect of Treg cells on IFN gamma secretion of autologous PBMCs was examined by ELISA. RESULTS: CHB patients presented a higher fraction of circulating CD4+ CD25 high Treg frequency than AHB patients (P < 0.05), but had no significant difference compared with healthy controls. CD4+ CD25 high Treg expressed high levels of CD45RO, HLA-DR and CTLA-4, low level of CD45RA, and expressed FoxP3 mRNA specifically. We also observed that Treg cells could suppress the expansion and IFN gamma secretion of autologous PBMCs when stimulated with HBV antigen or anti-CD3 antibody, and the suppressive effect was stronger when HBV antigen was used as stimulator. CONCLUSIONS: CHB patients presented a higher fraction of circulating Treg frequency than AHB patients at acute phase, but had no significant difference compared with healthy controls. FoxP3 mRNA was specifically expressed in CD4+ CD25+ cell population. Treg could suppress HBV antigen-specific T cell response in vitro. The study furthers our understanding of Treg's role in immunopathogenesis of hepatitis B.

Antigens, CD↗