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Biomedical subjects

Bo Zhang

Publications and source records attributed to Bo Zhang.

At least 145 records · Page 8Linked to original sources
PubMed2005

[Comparison of primary caries detection on smooth surface in the maxillary anterior teeth using QLF, digital photo and visual diagnosis].

PURPOSE: This study is to investigate the differences of primary caries detection on smooth surface in the maxillary anterior teeth using quantitative light-induced fluorescence(QLF),digital photo and visual examination. METHODS: Three hundreds of middle school students in Deyang city and Ziyang city were examined. Seventeen hundreds and thirty-two maxillary incisors and canines were included. After being cleaned and dried, the white spots (primary caries on smooth surface) were examined by QLF, digital camera, and visual examination. The difference among three methods was analyzed by Chi-square test using SPSS 11.5. RESULTS: In QLF examination, 24.08 percent of the examined teeth were found out having white spots. Results of the Chi-square test showed that QLF had a significantly higher capability(24.08%) on finding out the primary demineralized spots than digital camera(22.17%) and visual examination(20.61%). There was significant difference among the three diagnostic methods(P<0.05). CONCLUSION: The study suggested that QLF is a trustworthy, speedy, safe and noninvasive diagnosed method and was worthy extending and applying in the clinic.

Dental Caries↗
PubMed2005

[An analysis of induced expression and function of telomerase-regulation associated hALP gene on genotoxic agents].

OBJECTIVE: To confirm the responses and function of hALP, a telomerase-regulation associated gene, in DNA damage. METHODS: HeLa and Hep2 cells were treated by genotoxic agents H2O2 and cisplatin, and the induced expression of hALP was measured by quantitative RT-PCR and immunofluorescent histochemistry. The alterations in transcriptional activity of hALP promoter were estimated by luciferase reporter assays. The effects of genotoxic agents on cells in different status of hALP expression were analyzed by MTT method. RESULTS: The level of hALP mRNA could be increased when treated by 0.2 - 1.6 mmol/L H2O2 and reach a peak in concentration of 0.4 mmol/L. The induction could be observed after 6 h in the treatment of 0.4 mmol/L H2O2 and the higher level can be retained for 36 h. Similarly, cisplatin induced hALP mRNA expression is also dose and time dependent. The immunofluorescent staining showed that the treatment of 0.2 or 0.4 mmol/L H2O2, 0.2 or 0.5 micromol/L cisplatin increased the intensity of hALP protein in cellular nuclei. The luciferase assays demonstrated that both H2O2 and cisplatin could up-regulate hALP promoter activity through its upstream - 705 - +20 nt region. In cell survivor assay, the HeLa cells expressing sense hALP gene could grow continuously in the presence of 0.4 mmol/L H2O2 or 0. 5 micromol/L cisplatin while cells with antisense hALP or control cells were slower in growth. CONCLUSIONS: The expression of hALP gene could be up-regulated by DNA damage through activating transcription of its promoter, and increase cellular resistance to genotoxic agents.

Antineoplastic Agents↗
PubMed2005

[Study on the robust NIR calibration models for moisture].

The differences in sample moisture affect the robustness of NIR model obviously. In the present paper, three approaches, including preprocessing spectra, selecting wavelength, and setting up global calibration, were investigated to analyze the feasibility of setting up robust calibrations based on the protein content of wheat with different moistures. It has been found that with only spectral pretreatment method it fails to obtain satisfactory results, which can not remove the effects caused by moisture difference. Both selecting wavelengths and developing global calibration model proved to be good approaches for developing robust NIR calibration, yet developing global calibration is better. The mechanisms of the three different methods were also analyzed theoretically.

Calibration↗
PubMed2005

[Study of a multivariate statistical 5-ALA-based discrimination method for fluorescence spectra of colonic tissue of SD rats].

In order to diagnosis colon early cancer with laser-induced 5-ALA-PpIX fluorescence spectra, a multivariate statistical method to distinguish these fluorescence spectra acquired in vivo was developed. 343 spectra were collected from 8 normal SD rats, and 20 1,2-DMH-induced SD colon cancer models, and 12 second generation rats of induced rats. 150 min after trail intravenous injections of 5-ALA at a dose of 25 mg x kg(-1) BW, fluorescence spectra excited with 370 nm Ti-laser were collected in vivo. All spectra were divided into a calibration group and a prediction group. After preprocessing, 4 principal components were extracted with PCA. And then, discrimination models were built by stepwise multivariate logistic regression (SMLR) on calibration group. 3 pathological styles were combined each other, and then 3 SMLR models were derived. Normal tissues were classified from early cancers and advanced cancers with sensitivity of 100% and 98.4%, and specificity of 96% and 100%, and accuracy of 98% and 99.2% on prediction group, respectively. The multivariate statistical discrimination method of PCA and SMLR together can effectively distinguish normal tissues from early cancers and advanced cancers with high sensitivity and specificity by means of systemic 5-ALA at low dose. Laser induced fluorescence 5-ALA-based technique is promising for the detection of colonic early cancer.

Aminolevulinic Acid↗
PubMed2005

Establishment of retinoblastoma model in NOD-SCID mice and study of metastasis.

PURPOSE: To establish model of retinoblastoma subcutaneously in NOD-SCID mice and study rules of formation and distribution of retinoblastoma metastasis. METHODS: Retinoblastoma cells SO-RB50 were inoculated subcutaneously in NOD-SCID mice. Animal acts and tumor formation, growth and metastasis in NOD-SCID mice were observed. Primary and metastatic tumors were studied pathohistologically by HE and immunohistochemical staining. RESULTS: The latent periods of tumor growth were 12-19 days and the taken rate of tumor was 100%. 32 days later, 5 NOD-SCID mice were found with tumors that had metastasized to areas mainly located in the abdominal cavity and the side of the kidney; the metastatic time of tumors in the mice also differed. The tumor cells of the primary nodules and the metastasis were similar with human retinoblastoma cells and positive in immunohistochemical staining of NSE. CONCLUSION: The subcutaneous model of retinoblastoma in NOD-SCID mice showed a high taken rate and a short latent period of tumor, which had a high metastatic rate and was the best model in research of behaviors of retinoblastoma at present.

Animals↗
PubMed2005

[The comparison of HE staining and giemsa staining in detection of eosinophilic granulocytes in conjunctiva scroping].

PURPOSE: To find the better method of eosinophilic granulocytes staining by comparison between HE staining and Giemsa staining METHODS: Twenty conjunctivitis patients(40 eyes) were studied. The infected palpabral conjunctiva of both eyes were scroped and stained separately with Giemsa staining and HE staining. RESULT: Under microscope, eosinophilic granulocytes were more clear by Giemsa staining than HE staining. CONCLUSION: In showing eosinophilic granulocytes, Giemsa staining was better than HE staining.

Azure Stains↗
PubMed2004

Molecular cloning and characterization of a human gene involved in transcriptional regulation of hTERT.

Human telomerase reverse transcriptase (hTERT), the catalytic subunit of telomerase in human, has been identified as the rate-limiting factor in telomerase activity, but its detailed mechanism of transcription regulation remains unclear. In this investigation, a novel human gene telomerase transcriptional elements-interacting factor (TEIF) was isolated from HeLa cell based on hTERT promoter yeast one-hybrid assay. TEIF has a 2358-bp open reading frame encoding a predicted protein of 786 amino acids, which is functionally conserved in general eukaryotic species. The transcription of TEIF was detected in cells and expressed an 86-kDa native protein, distributing mainly in cellular nuclei. Its interaction with hTERT promoter was identified and the DNA binding potential was credited to C-terminus of TEIF. Transfection of TEIF into HeLa cells presented marked transactivation of hTERT promoter and stimulated both endogenous hTERT transcription and telomerase activities. These results suggest that TEIF protein might be a transcription regulator and take part in the activation of hTERT.

Adaptor Proteins, Vesicular Transport↗
PubMed2004

[Relationship between estradiol and the mitogenic activated protein kinase signal transduction pathway].

OBJECTIVE: To discuss the relationship between estradiol and the mitogenic activated protein kinase signal transduction pathway and the expression of the MAPK in the MCF-7 breast cancer cell-line. METHODS: Epithelial growth factor (EGF) and different concentration of estradiol to induce the expression of phosphospecific ERK1/2 (pERK1/2) in MCF-7 cell line was used and the expression of pERK1/2 with western-blotting was detected. Then antiestrogen ICI 182780 and MAPK inhibitor PD98059 to inhibit the expression of pERK1/2 was used. The cell cycle of MCF-7 was detected by FACS. RESULTS: EGF could significantly induce the expression of pERK1/2. Estradiol could also induce the expression of pERK1/2, but the intensity was less than the induction of EGF. The percentage of cells in the G(2)/M cell cycle after estradiol induction increased (18.38%) compared to the control group (10.52%) (P < 0.05). CONCLUSIONS: MAPK is an important regulatory signal in breast cancer. Its measurement in breast cancer tissues provides information about the degree of activation of various growth factor pathways. This molecule may also provide a molecular target for compounds designed to block cell proliferation.

Breast Neoplasms↗
PubMed2004

The nanopore electrode.

The fabrication and electrochemical characterization of truncated cone-shaped nanopore electrodes are reported. A nanopore electrode is a Pt disk electrode embedded at the bottom of a conical pore, the circular orifice of the pore having nanometer dimensions. The electrochemical properties of nanopore electrodes with orifice radii of 39 and 74 nm are presented. Both the steady-state and transient voltammetric behavior of the nanopore electrode are reported and compared to predictions obtained using finite-element simulations. The truncated cone-shaped pore electrode possesses a unique transport property-the steady-state flux of molecules into a deep pore is limited by the restriction near the pore orifice, and thus, the steady-state current is independent of the pore depth. This characteristic is potentially useful in studying transport through nanometer-scale orifices.

Journal Article↗
PubMed2004

Central neurocytoma: a clinicopathological and neuroradiological study.

Central neurocytoma (CNC) is an uncommon benign tumor of the central nervous system (CNS) occurring in adults and is more likely to be located in the region of the foramina of Monra. Few studies have described the neuroradiological features of CNC, and most are single case reports. Our aim was to analyze the clinicopathological and neuroradiological characteristics of CNC. We retrospectively studied the preoperative CT (n=2) and MRI (n=5) of three men and two women (mean age 45 years, ranging from 30 to 63 years) with pathologically proven CNC. The tumors were primarily located in the region of the foramina of Monra. Two of them occupied the lateral ventricle, appearing to be attached to the septum pellucidum, and the other three tumors arose from the septum pellucidum and extended into the lateral ventricles. The tumors were of mixed density with cystic features and patchy or fine calcification on noncontrast CT scans, and they were of low or isointense signal on T1- and heterogeneously hyperintense signal on T2- and FLAIR weighted images. Contrast enhancement varied greatly from very slight to intense. Immunohistochemical staining showed a positive reaction for synaptophysin (Syn), neuro-specific enclase (NSE), neurofilament protein (NF) in the tumor cells and glial fibrillary acid protein (GFAP) in the fibrillar zones. CNC should be taken into consideration first if a tumor arises from the region of the foramina of Monra with CNC neuroradiological characteristics and the patient is an adult.

Adult↗
PubMed2004

Selective separations of peptides with sequence deletions, single amino acid polymorphisms, and/or epimeric centers using macrocyclic glycopeptide liquid chromatography stationary phases.

Separating closely related peptides (those differing by one or two amino acids or the chirality of a single amino acid) can be challenging using reversed-phase liquid chromatography (LC), ion-exchange LC, or using ion-pairing agents. Also, the mobile phases that give the best separations in these modes may not be electrospray ionization mass spectrometry (ESI-MS) compatible. Forty-two peptides from 11 peptide families were separated on three macrocyclic glycopeptide stationary phases in reverse-phase mode using ESI-MS-compatible mobile phases. The peptide classes studied were angiotensin, bradykinin, alpha-bag cell factor, beta,gamma-bag cell factor, beta-casomorphin, dynorphin, enkephalin, leucokinin, lutinizing hormone releasing hormone, neurotinsin, substance P, and vasopressin. High selectivity was observed for single amino acid substitutions (achiral and chiral) regardless of the position of the substitution in the sequence. Mobile phase optimization, its effect on peptide elution behavior, and chromatographic efficiency is also discussed. Using LC-ESI-MS, a 2 ng limit of detection was obtained, two orders of magnitude lower than the UV detection limit.

Amino Acid Sequence↗
PubMed2004

The evidences of human orphan receptor COUP-TFII inhibiting telomerase activity through decreasing hTERT transcription.

Activation of hTERT, the human telomerase catalytic subunit, has been implicated as the critical event in triggering telomerase activity of cancer cells, but the details of regulation of hTERT need to be elucidated. By screening HeLa cDNA library with hTERT promoter-based yeast one-hybrid assay, one of positive clones, which potentially interacted with hTERT promoter, contained the full sequences of COUP-TFII cDNA. EMSA showed that the prepared His-tagged COUP-TFII could firmly bind to -201 to +35 fragment of hTERT promoter. The precise binding sites were confirmed by DNase I footprint analysis and proved to involve the E-box motif of hTERT promoter. Luciferase reporter assays indicated that COUP-TFII could suppress the transcription of hTERT promoter, and the inhibition to some extent could be reversed by co-transfection of c-myc. Stable introduction of COUP-TFII into HeLa cells decreased both endogenous hTERT expression and telomerase activity. The results suggested that the human COUP-TFII could specifically interact with hTERT promoter, in part via the E-box, and suppress the expression of hTERT.

Biological Assay↗
PubMed2004

Kinetic studies of iron deposition in horse spleen ferritin using H2O2 and O2 as oxidants.

The reaction of horse spleen ferritin (HoSF) with Fe2+ at pH 6.5 and 7.5 using O2, H2O2 and 1:1 a mixture of both showed that the iron deposition reaction using H2O2 is approximately 20- to 50-fold faster than the reaction with O2 alone. When H2O2 was added during the iron deposition reaction initiated with O2 as oxidant, Fe2+ was preferentially oxidized by H2O2, consistent with the above kinetic measurements. Both the O2 and H2O2 reactions were well defined from 15 to 40 degrees C from which activation parameters were determined. The iron deposition reaction was also studied using O2 as oxidant in the presence and absence of catalase using both stopped-flow and pumped-flow measurements. The presence of catalase decreased the rate of iron deposition by approximately 1.5-fold, and gave slightly smaller absorbance changes than in its absence. From the rate constants for the O2 (0.044 s(-1)) and H2O2 (0.67 s(-1)) iron-deposition reactions at pH 7.5, simulations of steady-state H2O2 concentrations were computed to be 0.45 microM. This low value and reported Fe2+/O2 values of 2.0-2.5 are consistent with H2O2 rapidly reacting by an alternate but unidentified pathway involving a system component such as the protein shell or the mineral core as previously postulated [Biochemistry 22 (1983) 876; Biochemistry 40 (2001) 10832].

Animals↗
PubMed2004

Inhibition of cholesteryl ester transfer protein activity by JTT-705 increases apolipoprotein E-containing high-density lipoprotein and favorably affects the function and enzyme composition of high-density lipoprotein in rabbits.

BACKGROUND: Inhibition of cholesteryl ester transfer protein (CETP) is an efficient way to increase high-density lipoprotein (HDL) levels in humans. We investigated the effects of the inhibition of CETP activity by a CETP inhibitor, JTT-705, on the function and composition of HDL particles. METHODS AND RESULTS: Japanese white rabbits were fed either normal rabbit chow LRC-4 (n=10) or a food admixture of LRC-4 and 0.75% JTT-705 (n=10) for 7 months. JTT-705 significantly inhibited CETP activities, increased HDL cholesterol (HDL-C) levels and the ratio of HDL2-C/HDL3-C, and decreased the fractional esterification rate of cholesterol in HDL, indicating preferentially increased large HDL particles. Treatment with JTT-705 increased all of the 3 charge-based HDL subfractions as determined by capillary isotachophoresis: fast-migrating, intermediate-migrating, and slow-migrating HDL. The percentage of slow HDL, ie, apolipoprotein E (apoE)-containing HDL and levels of apoE in HDL fraction, was also increased. JTT-705 treatment increased serum paraoxonase activity and HDL-associated platelet-activating factor acetylhydrolase activity, but decreased the plasma lysophosphatidylcholine concentration. CONCLUSIONS: Inhibition of CETP activity by JTT-705 not only increased the quantity of HDL, including HDL-C levels and charge-based HDL subfractions, but also favorably affected the size distribution of HDL subpopulations and the apolipoprotein and enzyme composition of HDL in rabbits.

1-Alkyl-2-acetylglycerophosphocholine Esterase↗
PubMed2004

[Development of oral vaccine carrying GCPII gene and its role in reducing the dosage of pentobarbital in rat: a primitive research].

OBJECTIVE: To develop an oral vaccine carrying glutamate carboxypeptidase II (GCP II) and to explore whether it can affect the dosage of pentobarbiturate. METHODS: Polymerase chain reaction, digestion of endonuclease and ligation, blue-white selection were used to construct an expression vector pcDNA3.1-GCP II. HEK293 cells were cultured. The vector pcDNA3.1-GCP II was transfected into the HEK293 cells by Ca(3)(PO(4))(2) coprecipitation method. The transfected HEK293 cells were cultured in HEM liquid culture prepared with G418. Three weeks after, positive clones, HEK293-GCP II, were identified. Reverse-transcription PCR and immunofluorescence cell staining were used to testify positive cell line; Method of CaCl(2) was used to prepare oral vaccine of attenuated Salmonella typhimurium carrying GCP II (SL-GCP II). Expression of SL-GCP II in vitro was observed by adding SL-GCP II into the primarily cultured macrophage. Fifty male SD rats were randomly divided into 2 groups of 25 rats: group A, undergoing intragastrical infusion of SL-GCP II, 600 micro l/time, in total 4 times in 4 days; and group B, as control group, undergoing intragastrical infusion of SL3261. Fifteen days after, 5 g/L pentobarbital sodium was injected intraperitoneally with the first dosage of 1.0 ml and the response was observed in 10 minutes, then 0.1 ml was added every time. The specific dosage of pentobarbital sodium was recorded when anesthesia meeting the requirement of operation was reached. Phenobarbital sodium of this dosage was used to anesthetize the rats to observe the response of the rats. Immunofluorescence method was used to detect the titer of antibody in rat circulation with HEK293 GCP II cells as target cells. RESULTS: An expression vector containing GCP II, pCMV-GCP II, pCDNA3.1-GCP II was constructed. The cell line, HEK 293-GCP II was established. In vitro experiment proved that primarily cultured macrophage phagocytized SL-GCP II and effectively expressed GCP II gene. After infusion of the oral vaccine 22 of the 25 SD rats of the group A produce GCP II antibodies. The dosage of pentobarbiturate used in experimental group was 36.9 mg/kg +/- 1.6 mg/kg; significantly lower than that in the control group (40.8 mg/kg +/- 1.4 mg/kg, P = 0.00). CONCLUSION: An oral vaccine carrying GCP II gene has been developed that activates the immune response of rat to produce GCP II antibodies and lower the dosage of pentobarbiturate needed.

Administration, Oral↗
PubMed2004

Cloning and expression of mouse peroxiredoxin I in IEC-6 Cells.

AIM: To clone and express mouse peroxiredoxin I in IEC-6 cells. METHODS: Total RNAs were isolated from cultured IEC-6 cells, and the coding region of peroxiredoxin I was amplified by RT-PCR. After it was cloned into T-vector and sequenced, pSG5 was used to transiently express peroxiredoxin I in IEC-6 by liposome-mediated transfection, and the expression of peroxiredoxin I was evaluated by RT-PCR and Western blot. RESULTS: A DNA fragment about 750 bp was amplified from total RNAs of IEC-6 cells using specific primers of peroxiredoxin I. The sequencing confirmed the coding region was successfully cloned into T-vector, which was completely coincident with the sequence in GeneBank. After the EcoRI-BamHI fragment of T-vector containing peroxiredoxin I was inserted into pSG5, the recombinant plasmid was transferred to IEC-6 cells. RT-PCR assay showed that a DNA fragment of 930 bp could be amplified, which indicated the transcription of pSG5-Prx. Western blot confirmed the expression of peroxiredoxin I in IEC-6 cells. CONCLUSION: Mouse peroxiredoxin I can be successfully expressed in IEC-6 cells.

Animals↗