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Biomedical subjects

Jing Zhu

Publications and source records attributed to Jing Zhu.

At least 37 records · Page 2Linked to original sources
PubMed2006

[Vocal sound study in supracricoid partial laryngectomy].

OBJECTIVE: Vocal sound was studied in 21 patients underwent supracricoid partial laryngectomy using Dr. Speech. METHOD: Vocal sound tests and frequency spectrum analysis were used in 4 different approaches (CHEP, CHP, TCHEP, TCHP) both before and after the operation. RESULT: Vibration pattern of new glottidis formed after the four different operation approaches was approximately the same demonstrating an augmentation of mucous membrane fluctuation. This vibration pattern were increasing and stabilizing gradually with time. CONCLUSION: Retaining on both sides and one side in supracricoid partial laryngectomy facilitates restoration of vocal function.

Aged↗
PubMed2006

[Effects of estrogen receptor beta on proliferation of ovarian clear cell adenocarcinoma ES-2 in vitro and in vivo].

OBJECTIVE: To investigate the involvement of estrogen receptor (ER) beta in the proliferation of ovarian clear cell adenocarcinoma by restoring ERbeta expression in a cell line ES-2. METHODS: A plasmid with full length ERbeta cDNA, pRSV-ERbeta and its negative vector control pRSV were introduced into ES-2. The cells transfected were named according to the plasmids: ES-pRSV, ES-pRSV-ERbeta. RT-PCR and western blot were used to detect the expression of ERbeta in ES-2, ES-pRSV and ES-pRSV-ERbeta cells. The growth activities of cells in vitro were detected by methyl thiazolyl tetrazolium (MTT) assay, and in vivo growth in nude mice was also observed. Flow cytometry was performed to show the change of cell cycles. RESULTS: The ES-pRSV-ERbeta cells were identified with ERbeta mRNA and protein expression. The growth activities of ES-pRSV-ERbeta were inhibited in vitro. In MTT analysis, the values of ES-2, ES-pRSV, and ES-pRSV-ERbeta cells were 0.78 +/- 0.05, 0.81 +/- 0.06, and 0.53 +/- 0.07 (the third was lower compared with the former two, P < 0.01). In vivo, the volume of transplants of ES-pRSV-ERbeta cells in mice, (2868 +/- 879) mm(3) was smaller than that in ES-2, (3603 +/- 724) mm(3), and in ES-pRSV, (3913 +/- 624) mm(3) (P < 0.05). The S phase ratios of the cell cycle of ES-2, ES-pRSV, and ES-pRSV-ERbeta were (37 +/- 9)%, (39 +/- 10)%, and (20 +/- 5)% (P < 0.05). CONCLUSIONS: ERbeta may play an important role in the proliferation, and DNA synthesis of ES-2. The evidence indicates ERbeta may be an inhibitor in the initiation and development of ovarian clear cell adenocarcinoma.

Adenocarcinoma, Clear Cell↗
PubMed2006

[Screening of differentially expressed genes in rats with cardiomyopathy after bone marrow mesenchymal stem cell transplantation].

OBJECTIVE: Earlier studies have confirmed that mesenchymal stem cells (MSCs) can transdifferentiate into myocytes and improve heart function in 2 weeks. But the mechanism is not clear. In this study, the mechanism of improvement of heart function after transplantation of MSCs was examined with suppression subtractive hybridization (SSH). METHODS: MSCs were isolated from thighone and tibia of Wistar rats, purified by adhesion-screening method, and expanded in vitro. Intraperitoneal injection of doxorubicin (at 2.5 mg/kg/time and total doses of 15 mg/kg) established cardiomyopathy models. MSCs were transplanted into cardiomyocytes. The differential genes between tester (rats with cardiomyopathy that were injected with MSCs) and driver (rats with cardiomyopathy that were injected with equivalent volume of culture medium) were screened with suppression subtractive hybridization. RESULTS: After 4 weeks of intraperitoneal injection of doxorubicin, left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS) decreased by 26.48% and 40.61%, respectively (P < 0.01), as compared with those of normal group. Cardiomyopathy model was established successfully. And the heart function of the rats with cardiomyopathy was significantly improved after transplantation. Sixteen gene fragments were detected, and 12 of them were up-regulated in testers. They were rattus norvegicus mitochondrial BN/SsNHsdMCW, rattus norvegicus strain mitochondrial F344 X BN F1, rattus norvegicus mitochondrion H(+)-ATP synthase alphase subunit (Atp5al) mRNA, rattus norvegicus BHE/Cdb tRNA-Lys gene, rat mitochondrial H(+)-ATP synthase alpha subunit mRNA, rattus norvegic (wild-caught animal) complete mitochondrial genome, rattus norvegic clone BB.1.4.1 unknown Glu-Pro dipeptide repeat protein mRNA, Arabidopsis thaliana transgenic line C DNA, rat mitochondrial ATP synthase beta subunit mRNA, rattus norvegic mitochondrial genome, rat cardiac troponin T mRNA and rat mRNA for beta-globin. Four gene fragments were down-regulated in testers. They were rat mRNA for sarcomeric mitochondrial creatine kinase, rat mRNA for ribosomal phosphoprotein P2, rat alpha-crystallin B chain mRNA and rattus norvegicus NADH-ubiquinone oxidoreductase Fe-S protein 7 mRNA. CONCLUSION: The expression of the genes relating to mitochondrial synthesizing and contracting proteins synthesizing increased after MSC transplantation. The genes might enhance energy synthesis and promote MSC transdifferentiate into myocytes, and then improve heart function of rats with cardiomyopathy.

Animals↗
PubMed2005

[The role of tissue factor in the invasion and metastasis of colorectal carcinoma cells].

OBJECTIVE: To investigate the role of tissue factor (TF) in the invasion and hematogenous metastasis of human colorectal carcinoma cells. METHODS: The eukaryotic expression vectors pcDNA3.1/Zeo bearing either sense or antisense TFcDNA were transfected into HT-29 and LoVo cells by the way of lipofactamine 2000. TF proteins in transfected cells were detected by Western Blot. Then the transfected and un-transfected tumor cells were implanted into nude mice (Balb/c Nu/Nu) to produce primary tumor, lung metastasis and liver metastasis respectively. RESULTS: HT-29 and LoVo cells with sense-TFcDNA transfection showed increased TF expression compared with the cells without transfection, but the cells with antisense-TFcDNA transfection got the contrary change. The primary tumor growth and invasive range, lung metastasis and live metastasis all increased in sense transfectants but reduced in antisense transfectants. CONCLUSIONS: TF can increase the invasion and hematogenous metastatic ability of human colorectal carcinoma cells.

Animals↗
PubMed2005

Suppression of macrophage responses to bacterial lipopolysaccharide (LPS) by secretory leukocyte protease inhibitor (SLPI) is independent of its anti-protease function.

Secretory leukocyte protease inhibitor (SLPI), a potent serine protease inhibitor, has been shown to suppress macrophage responses to bacterial lipopolysaccharide (LPS). SLPI contains two topologically superimposable domains. Its C-terminal domain binds and inhibits target proteases. It is not clear whether SLPI's anti-protease function plays a role in the LPS-inhibitory action of SLPI. Four single amino acid substitution mutants of SLPI, M73G, M73F, M73E and M73K, were generated. Wild type SLPI is a potent inhibitor of chymotrypsin and elastase. Mutants M73G and M73F selectively lost inhibitory function towards chymotrypsin and elastase, respectively, whereas mutants M73K and M73E inhibited neither elastase nor chymotrypsin. Macrophage cell lines were established from RAW264.7 cells to stably express each SLPI mutant. Expression of the SLPI protease inhibition mutants suppressed NO and TNF production in response to LPS in a similar fashion as wild type SLPI. Expression of truncated forms of SLPI, containing only its N-terminus or its C-terminus, was similarly sufficient to confer inhibition of LPS responses. Thus, the LPS-inhibitory action of SLPI is independent of its anti-protease function.

Amino Acid Substitution↗
PubMed2005

Effects of Kv1.1 channel glycosylation on C-type inactivation and simulated action potentials.

Kv1.1 channels are brain glycoproteins that play an important role in repolarization of action potentials. In previous work, we showed that lack of N-glycosylation, particularly lack of sialylation, of Kv1.1 affected its macroscopic gating properties and slowed activation and C-type inactivation kinetics and produced a depolarized shift in the steady-state activation curve. In our current study, we used single channel analysis to investigate voltage-independent C-type inactivation in both Kv1.1 and Kv1.1N207Q, a glycosylation mutant. Both channels underwent brief and long-lived closures, and the lifetime and frequency of the long-lived closed states were voltage-independent and similar for both channels. We found that, as in macroscopic measurements, Kv1.1N207Q exhibited a approximately 8 mV positive shift in its single channel fractional open time (fo) and a shallower fo-voltage slope compared with Kv1.1. Data suggested that C-type inactivation reflected the equilibration time with at least two slow voltage-independent long-lived closed states that followed the rapid activation process. In addition, data simulation indicated that the C-type inactivation process reflected the equilibration time between the open state and at least two long-lived closed states. Moreover, the faster macroscopic current decay in Kv1.1 mostly reflected a slower equilibration time in these channels as compared with Kv1.1N207Q. Finally, action potential simulations indicated that the N207Q mutation broaden the action potential and decreased the interspike interval. The shape of the action potential was not significantly affected by C-type inactivation, however, for a given channel, C-type inactivation increased the interspike interval. Data and simulations suggested that excitable cells could use differences in K(+) channel glycosylation degree as an additional mechanism to increase channel functional diversity which could modify cell excitability.

Action Potentials↗
PubMed2005

Theoretical electron energy-loss spectroscopy and its application in materials research.

Electron energy-loss near-edge fine structure (ELNES) of group-III nitrides is calculated using a pseudopotential plan wave method within the framework of density functional theory. Core-hole effect and supercell size influence are investigated. Based on our present and earlier work, a comprehensive understanding of theoretical ELNES application in materials research is demonstrated: interpreting experimental spectra, predicating theoretical reference spectra when reliable experimental spectra are not available, identifying ELNES-structure correlation and estimating the reliability of experimental spectra.

Journal Article↗
PubMed2005

Comparative study of the H-bond and FTIR spectra between 2,2-hydroxymethyl propionic acid and 2,2-hydroxymethyl butanoic acid.

In the present paper, the FTIR band and H-bond differences between the two dihydroxy-based carboxyls, 2,2-hydroxymethyl butanoic acid (hereinafter abbreviated to DMBA) and 2,2-hydroxymethyl propionic acid (hereinafter abbreviated to DMPA), were analyzed based on the crystal structure as well as the relation between H-bond and FTIR band of DMPA. In addition, the energy and length of the H-bonds formed between COOH, between OH, between COOH and OH were also calculated via molecular modeling. The results showed that three H-bond types existing in DMPA while only two in DMBA. The COOH pattern and H-bond type in DMBA and DMPA can be preliminarily judged according to the band position and relative strength of the nuOH and nuCOOH in FTIR spectrum. The H atom in COOH is a stronger H-bond donor than that in primary OH, while the O atom in primary OH is a stronger H-bond acceptor than that in COOH. The H-bond formed by two COOH is, therefore, weaker than that formed by COOH (as donor) and OH (as acceptor), which makes nuC=O shift to lower frequency in DMPA than in DMBA.

Butyrates↗
PubMed2005

Synthesis of nano/micro zinc oxide rods and arrays by thermal evaporation approach on cylindrical shape substrate.

Nano and micro ZnO rods and arrays have been synthesized by a simple thermal evaporation approach on a cylindrical shape substrate. Most of the synthesized ZnO products are single crystalline with a hexagonal structure and grow along the [0001] direction. Individual protrusive ZnO rods and well-aligned arrays are two typical products in our work. The individual protrusive ZnO rods have diameters of 25 nm approximately 2.1 microm and lengths from several hundred nanometers to 40 microm, while in the well-aligned arrays, the diameter and length of each ZnO rod range from 60 nm to 1.2 microm and from 4 microm to 6 microm, respectively. The heating temperature and deposition position are two key points to control the diameters of the rods. The growth mechanism is discussed and proposed. The perfect crystalline ZnO rods with different scales from nanometer to micrometer are good models for the investigation of the size effect of physical and chemical properties of one-dimensional material.

Journal Article↗
PubMed2005

Refinement of the crystal structural parameters of La2/3Ca1/3MnO3 using quantitative convergent-beam electron diffraction.

Crystal structural parameters (seven positional parameters and four isotropic Debye-Waller factors) of La(2/3)Ca(1/3)MnO(3) have been refined using the quantitative convergent-beam electron diffraction (QCBED) method. Using intensity information of many higher-order Laue-zone reflections simultaneously is essential to refine structural parameters accurately. The effective global optimization algorithm was used to avoid the problems of input values and local minima. The fittings of the differential coefficients of one-dimensional experimental intensities and theoretical ones calculated by the dynamical diffraction theory were carried out with the normalized Euclidean distance criterion. Thus, all of these improve the accuracy and reliability of the analysis. The calculated results with the refined parameters agree with the experiments. The refined parameters also agree with the Rietveld refinement results of neutron diffraction.

Journal Article↗
PubMed2005

[Expression of proline-rich tyrosine kinase-2 (Pyk2) in gastric carcinoma and its significance].

OBJECTIVE: To investigate whether proline-rich tyrosine kinase-2 (Pyk2) is expressed differently in normal gastric mucosas and gastric carcinoma tissues and further to evaluate its significance. METHODS: Expressions of Pyk2 in 59 cases of normal gastric mucosas and 52 cases of gastric carcinoma tissues were analysed by immunohistochemical methods. RESULTS: Immunohistochemical studies showed that the positive rates of Pyk2 protein expression in normal gastric mucosas and gastric carcinoma tissues were 86.44% (51/59) and 19.23% (10/52) respectively. The difference between normal gastric mucosas and gastric carcinoma tissues was statistically significant (P<0.05). The positive rates of Pyk2 expression in highly differentiated gastric carcinoma and moderately/lowly differentiated gastric carcinoma were 47.37% (9/19) and 3.03% (1/33) respectively. Statistically significant differences (P<0.05) were observed in the levels of Pyk2 expression between highly differentiated gastric carcinoma and moderately/lowly differentiated gastric carcinoma. The positive rates of Pyk2 expression at different TNM stages gastric carcinoma were respectively: stage I 66.67% (6/9), stage II 30% (3/10), stage III 3.45% (1/29), stage IV 0% (0/4). The differences were statistically significant [(II+III+IV) v I, chi2=15.767, P<0.05]. CONCLUSION: In this study, we demonstrate that Pyk2 is expressed in normal gastric mucosas, whereas its expression declines significantly or almost disappears in gastric carcinoma tissues. The expression of Pyk2 progressively decreases with increasing grade of malignancy and TNM stages of gastric carcinoma. This phenomenon indicates that Pyk2 expression may be involved in the generation and development of gastric carcinoma.

Adenocarcinoma↗
PubMed2005

[Role of tissue factor in the invasion of cultured human colon carcinoma cells and its correlation with matrix metalloproteinases].

OBJECTIVE: To investigate the role of tissue factor expression in the invasive ability of human colon carcinoma cells and to analyze the correlation between tissue factor and MMP-2 and MMP-9. METHODS: HT-29 cells with sense-TFcDNA transfection and LoVo cells with antisense-TFcDNA transfection were implanted subcutaneously into nude mice as well as controls. The expressions of MMP-9 and MMP-2 at the protein and mRNA levels were detected by Western blot and RT-PCR respectively; Gelatin zymography was used for assay of the MMP-9 and MMP-2 activities in the supernatant cultured media of LoVo cells with antisense-TFcDNA transfection and controls. RESULTS: The expressions of MMP-9 and MMP-2 at the protein and mRNA levels in the group of HT-29 cells with sense-TFcDNA were significantly increased with untransfected HT-29 cells. The expression in the group of LoVo cells with antisense-TFcDNA had a significant decrease than that of the controls. The MMP-9 and MMP-2 activities of LoVo cells with antisense-TFcDNA were weakened because of the lower expression of tissue factor by gelatin zymography. The expression of MMP-9 and MMP-2 were closely correlated to the expression of tissue factor. CONCLUSION: Tissue factor can increase the invasive ability of human colon carcinoma cells. The partial mechanism is that TF can upregulate the expressions of MMP-9 and MMP-2. Tissue factor may be an inner agonist in the secretion of MMPs in colon carcinoma cells.

Animals↗
PubMed2005

Amino acids in the pore region of Kv1 potassium channels dictate cell-surface protein levels: a possible trafficking code in the Kv1 subfamily.

Kv1.1 and Kv1.4 potassium channels have different pore region determinants that were found to affect their cell-surface levels positively and negatively [Zhu, Watanabe, Gomez and Thornhill (2001) J. Biol. Chem. 276, 39419-39427; Zhu, Watanabe, Gomez and Thornhill (2003) J. Biol. Chem. 278, 25558-25567; Zhu, Watanabe, Gomez and Thornhill (2003) Biochem. J. 375, 761-768]. In the present study, we focused on the deep pore region of Kv1 members to test whether a cell-surface trafficking code was dictated by two amino acids. Kv1 channels with a threonine/lysine amino acid pair in a non-contiguous pore region promoted high surface levels, whereas a serine/tyrosine amino acid pair inhibited high surface expression by inducing a high level of partial endoplasmic reticulum retention. Our work suggests that a possible positive trafficking amino acid pair coding here for the Kv1 subfamily is Thr/Lys>Thr/Val>Thr/Tyr>Thr/Arg approximately Thr/His>Ser/Val>Ser/Tyr>Ser/Lys. The Kv1 trafficking code was not transferable to a Kv2 family member and thus it appears that it only governs surface levels in the context of its Kv1 native pore loop region and/or its S5 and S6 regions. All members of a given Kv2, Kv3 or Kv4 potassium channel subfamily have identical amino acids at similar positions in their deep pore regions (Thr/Tyr or Thr/Val), which suggests that any difference in surface levels among members is not dictated by these amino acids. Thus a major determinant for cell-surface trafficking of Kv1 potassium channels is an amino acid pair in their deep pore regions, whereas the cell-surface levels of a given Kv2, Kv3 or Kv4 subfamily member are probably not affected by these amino acids.

Amino Acid Sequence↗
PubMed2005

Towards precise classification of cancers based on robust gene functional expression profiles.

BACKGROUND: Development of robust and efficient methods for analyzing and interpreting high dimension gene expression profiles continues to be a focus in computational biology. The accumulated experiment evidence supports the assumption that genes express and perform their functions in modular fashions in cells. Therefore, there is an open space for development of the timely and relevant computational algorithms that use robust functional expression profiles towards precise classification of complex human diseases at the modular level. RESULTS: Inspired by the insight that genes act as a module to carry out a highly integrated cellular function, we thus define a low dimension functional expression profile for data reduction. After annotating each individual gene to functional categories defined in a proper gene function classification system such as Gene Ontology applied in this study, we identify those functional categories enriched with differentially expressed genes. For each functional category or functional module, we compute a summary measure (s) for the raw expression values of the annotated genes to capture the overall activity level of the module. In this way, we can treat the gene expressions within a functional module as an integrative data point to replace the multiple values of individual genes. We compare the classification performance of decision trees based on functional expression profiles with the conventional gene expression profiles using four publicly available datasets, which indicates that precise classification of tumour types and improved interpretation can be achieved with the reduced functional expression profiles. CONCLUSION: This modular approach is demonstrated to be a powerful alternative approach to analyzing high dimension microarray data and is robust to high measurement noise and intrinsic biological variance inherent in microarray data. Furthermore, efficient integration with current biological knowledge has facilitated the interpretation of the underlying molecular mechanisms for complex human diseases at the modular level.

Algorithms↗