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Biomedical subjects

Yong Zhang

Publications and source records attributed to Yong Zhang.

At least 127 records · Page 7Linked to original sources
PubMed2006

[Operative management of acetabular fracture].

OBJECTIVE: To investigate the indication, operative approach, postoperative management, and complication of acetabular fracture. METHODS: Sixty-eight patients (51 males, 17 females; age 15-65 years) with acetabular fracture were reviewed retrospectively. Among the patients, 55 were injured in the traffic accidents and 13 were injured in the falls (acute injury in 60, old injury in 8). According to the Letournel classification, 16 had a fracture of the posterior wall, 13 had a fracture of the posterior wall and posterior column, 12 had a fracture of the anterior wall and anterior column, 8 had a fracture of the anterior and posterior column, and 19 had a transverse acetabular fracture. All the patients underwent an operative treatment. RESULTS: There was no injury to the nerves and blood vessels during the operation. According to the 1-12-year follow-up for 51 patients, 26 (51.0%) patients had an excellent function, 17 (33.3%)had a good function, 6 (11.8%) had a fair function, and 2 (3.9%) had a poor function. The excellent and good rate was 84.3%. After operation, heterotopic ossification was observed in 4 patients, and necrosis of the femoral head in 2 patients. CONCLUSION: Operative management should be performed as soon as possible in the patients with a displaced acetabular fracture. Recovery of the stability of the acet cartilage is important to the recovery of the function. tawulum and smoothness of the acetabular articular

Acetabulum↗
PubMed2006

[siRNA-mediated silencing of ClC-2 gene inhibits proliferation of human U-87 glioma cells].

BACKGROUND & OBJECTIVE: Small interfering RNA (siRNA), which has been used to inhibit mammalian gene expression, is demonstrated to be an effective tool for gene function investigation. The aim of the present study was to observe the effect of siRNA, which was designed to target volume-regulated chloride channel ClC-2 gene, on the proliferation of a human glioma cell line U-87. METHODS: Two recombinant eukaryotic CIC-2 siRNA expression vectors were designed and constructed. Sequences were identified and confirmed by restrictive endonuclease digestion and DNA sequencing. The empty vector, pSUPER. puro, and two recombinant plasmids, pSUPER. puro-shRNA-ClC-21 and pSUPER. puro-shRNA-ClC-22, were transfected into U-87 cells using Lipofectamine2000 (Groups: PP0, PP1 and PP2, respectively). ClC-2 mRNA expression was detected by reverse transcription polymerase chain reaction (RT-PCR); the cellular proliferation rate was determined by MTT assay; the cell cycle was measured by flow cytometry (FCM); and the cell colony formation rate was measured by plate colony formation assay. RESULTS: The DNA fragments encoding siRNA targeting ClC-2-gene were successfully connected onto pSUPER. puro vector. ClC-2 mRNA expression and the cell growth rate in PP1 and PP2 groups were significantly inhibited compared to those in PP0 and control groups. Meanwhile, cell cycle was arrested in G1 phase and the percentage of G1 phase cells were increased by about 30.24% in PP1 and 18.04% in PP2 vs. in control and PP0 groups, P < 0.05. Moreover, the cell colony formation rates were statistically decreased in siRNA treated groups, which were (11.0+/-1.0)% in PP1 and (20+/-3.1)% in PP2 vs. (46.5+/-1.6)% in control and (47.5+/-2.8)% in PP0 groups (P<0.01). CONCLUSION: These results demonstrate that CIC-2 siRNA could inhibit the cell proliferation of a human glioma cell line U-87, thus ClC-2 gene may be used as a novel target for the suppression of the growth of human malignant glioma cells.

Brain Neoplasms↗
PubMed2006

[Integration between M3 muscarinic acetylcholine receptor and connexin 43 as antiarrhythmic targets in rat ventricular myocardium].

AIM: To optimize the method of investigating structural integration between proteins and study the integration between arrhythmia related proteins in molecular level. METHODS: Immunostaining the normal ventricular myocytes was used to observe the distribution of connexin 43 and muscarinic acetylcholine receptor (mAChR). The five mAChR subtypes were precipitated using immunoprecipitation. Then, SDS-PAGE and Western blotting with the anti-connexin 43 antibody were performed to observe whether they were structurally integrated. Further, different concentrations of detergent were used to observe whether this relationship could be broken. RESULTS: The five subtypes of mAChR existed in the cardiac myocyte of the rat, and all the five mAChR subtypes combined with connexin 43. In the normal rat ventricular myocyte membrane, connexin 43 and M3 receptor are co-located. When adding certain concentration of detergent to the membrane protein, the integration between M3 receptor and connexin 43 was broken, and the phosphorylated form of connexin 43 integrated with M3 receptor. CONCLUSION: The results indicated that the structural integration between mAChR and phosphorylation of connexin 43 existed in rat ventricular myocardium, and this integration could be broken by certain concentration of detergent.

Animals↗
PubMed2006

[Chicken genome project and its application in genetic research].

Chicken is an important model organism for studying all sorts of biological problems due to its unique biological features. Two strains of chicken, the egg-laying layer and meat-producing broiler, which were generated from selective breeding, come to be ideal models for understanding the molecular mechanisms underlying different phenotypes. The Chicken Genome Project provides a large amount of information for research using chicken as the model. This review summarizes the development of the Chicken Genome Project, as well as the strategies for researching the quantitative traits of different chicken strains using the information of the Chicken Genome. We also give a perspective of the developmental and genetic studies that can be conducted using the chicken as a model organism as well as using its genomic information.

Animals↗
PubMed2006

[The change of nuclear factor-kappa B expression in the lung tissues of chronic hypoxic rats].

OBJECTIVE: To investigate the change of nuclear factor-kappa B (NF-kappaB) expression in the lung tissues from chronic hypoxic rats and the role of NF-kappaB in the pathogenesis of hypoxic pulmonary hypertension. METHODS: Twenty male SD rats were randomly divided into two groups: control group and hypoxic group. The animal model of pulmonary hypertension was established by exposing the rats to normabaric hypoxic conditions for three weeks. The mean pulmonary arterial pressure (mPAP) was measured by a right cardiac catheterization. The indices of wall thickness of pulmonary arteriole (WT% and WA%) were measured by a computerized image analyzer. NF-kappaB expression in lung tissues were observed by using immunohistochemistry. RESULTS: (1) The mPAP of hypoxic rats was (29.1 +/- 4.5) mmHg,and it was (16.8 +/- 2.6) mmHg in normal rats, there was significant difference between two groups (P < 0.001). (2) In hypoxic group, the WT% was (22.36 +/- 2.99)% and WA% was (69.14 +/- 5.38)%; in normal group, WT% was (15.36 +/- 3.08)% and WA% was (46.75 +/- 6.54)%, the differences were significant (P < 0.01). (3) Both normal and hypoxic group, there were positive cells for NF-kappaB nuclear staining in lung tissues of rats. The percentage of positive cells for NF-kappaB nuclear staining in bronchiolar epithelial cells was significantly increased in the hypoxic group [(29.11 +/- 1.12)%] than that in the control group [(12.23 +/- 1.08)%], P < 0.001. CONCLUSION: NF-kappaB expression is increased in the lung tissue of rats with chronic hypoxia. It may play a role in the pathogenic process of hypoxic pulmonary hypertension.

Animals↗
PubMed2006

[Increased sensitivity to chemotherapeutic drug by RNAi targeting Hsp701A in HepG2 cells].

AIM: To investigate the effects on chemotherapeutic sensitivity to the drugs of tumor cells induced by Hsp701A targeting siRNA expression vector. METHODS: Specific small interference RNA (siRNA) targeting Hsp701A gene was generated and its eukaryotic expression vector was constructed and transfected into human HepG2 cells.Sensitivity to the chemotherapeutic drug of HepG2 cells transfected with the vector was detected by MTT colorimetry. RESULTS: The eukaryotic expression vector of siRNA targeting Hsp701A was successfully constructed and transfected into human HepG2 cells. Sensitivity to the chemotherapeutic drug of HepG2 cells was increased after Hsp701A was knock down (P<0.05). CONCLUSION: Knockdown of Hsp701A gene by siRNA enhances sensitivity to chemotherapeutic drug in HepG2 cells.

Animals↗
PubMed2006

[Effects of glutamine given through different avenues on intestine mucosal barrier function in burned rats].

OBJECTIVE: To observe the effect of glutamine given through different avenues on intestine mucosal barrier damage induced by severe burn injury. METHODS: One hundred and sixty Wistar rats were randomly divided into four groups: namely normal control (C group), burned control (B group), parenteral nutrition with glutamine (PN+GLN group) and enteral nutrition with glutamine (EN+GLN group). Rats in B group, PN+GLN group, and EN+GLN group were subjected to 30% total body surface area (TBSA) full-thickness burn injury. In the latter three groups, nutritional intake was isonitrogenous and isocaloric. In PN+GLN group and EN+GLN group the nutrition were supplemented with glutamine 1.0 g.kg(-1).d(-1), and in B group tyrosine 1.0 g.kg(-1).d(-1). Indexes relevant to injury to the intestine were determined on postburn day (PBD) 1, 3, 5, 7 and 10. RESULTS: After burn injury, the index of intestinal mucosal injury, intestine mucosal permeability and the activity of plasma diamine oxidase (DAO) were significant increased compared with C group (all P<0.01). On the other hand, the intestine mucosal blood flow (IMBF), mucosa thickness, villous height, crypt depth and intestinal epithelial proliferation index were significantly decreased (P<0.05 or P<0.01). Compared with B group, the extent of changes in these indices were lowered in PN+GLN group and EN+GLN group (P<0.05 or P<0.01), and the effects were more marked in EN+GLN group than those in PN+GLN group. CONCLUSION: GLN is beneficial in minimizing intestinal injury, promoting intestinal mucosal repair. Enteral supplementation of GLN is a better way of administration.

Animals↗
PubMed2005

Effect of pseudolaric acid B on gastric cancer cells: inhibition of proliferation and induction of apoptosis.

AIM: To examine the effect of pseudolaric acid B on the growth of human gastric cancer cell line, AGS, and its possible mechanism of action. METHODS: Growth inhibition by pseudolaric acid B was analyzed using MTT assay. Apoptotic cells were detected using Hoechst 33258 staining, and confirmed by DNA fragmentation analysis. Western blot was used to detect the expression of apoptosis-regulated gene Bcl-2, caspase 3, and cleavage of poly (ADP-ribose) polymerase-1 (PARP-1). RESULTS: Pseudolaric acid B inhibited the growth of AGS cells in a time- and dose-dependent manner by arresting the cells at G(2)/M phase, which was accompanied with a decrease in the levels of cdc2. AGS cells treated with pseudolaric acid B showed typical characteristics of apoptosis including chromatin condensation and DNA fragmentation. Moreover, treatment of AGS cells with pseudolaric acid B was also associated with decreased levels of the anti-apoptotic protein Bcl-2, activation of caspase-3, and proteolytic cleavage of PARP-1. CONCLUSION: Pseudolaric acid B can dramatically suppress the AGS cell growth by inducing apoptosis after G(2)/M phase arrest. These findings are consistent with the possibility that G(2)/M phase arrest is mediated by the down-regulation of cdc2 levels. The data also suggest that pseudolaric acid B can trigger apoptosis by decreasing Bcl-2 levels and activating caspase-3 protease.

Apoptosis↗
PubMed2005

Micropatterning of polystyrene nanoparticles and its bioapplications.

Micropatterning of biomolecules forms the basis of cell culture, biosensor and microarray technology. Currently, the most widely used techniques are photoresist lithography, soft lithography or using robots which all involve multi-step surface modification directly on a planar substrate. Here we report a method to pattern biomolecules through self-assembling polystyrene nanoparticles in arrayed microwells on a solid surface to form well-ordered patterning, followed by attaching biomolecules to the assembled nanoparticles. The formation of colloidal patterns depends on capillary force, surface wettability and physical confinement. This method can be used for micropatterning a variety of biomolecules such as protein and antibody.

Colloids↗
PubMed2005

A novel two-dimensional network cadmium(II) coordination polymer containing one 1,4-bis(1,2,4-triazol-1-yl)butane and double dicyanamide bridges.

In the crystal structure of the title complex, poly[mu-1,4-bis(1,2,4-triazol-1-yl)butane-di-mu-1,5-dicyanamido-cadmium(II)], [Cd(C2N3)2(C8H12N6)]n or [Cd(dca)2(btb)]n, where dca is dicyanamide and btb is 1,4-bis(1,2,4-triazol-1-yl)butane, each Cd(II) atom occupies a center of symmetry and is in a six-coordinated distorted octahedral environment. Four N atoms from four dca ligands fill the equatorial positions, and two N atoms from two btb ligands occupy the axial positions. The dca ligands adopt an end-to-end coordination mode and link the Cd(II) atoms to form a 12-membered Cd(dca)2Cd ring, and neighboring rings extend along the b axis to form a [Cd(dca)2]n chain. The btb ligands, acting as bridging bidentate ligands, link the Cd(II) atoms of adjacent one-dimensional [Cd(dca)2]n chains, forming a rhombic two-dimensional network.

Journal Article↗
PubMed2005

Solvothermal syntheses of [Ln(en)3(H2O)x(mu(3-x)-SbS4)] (Ln = La, x = 0; Ln = Nd, x = 1) and [Ln(en)4]SbS4.0.5en (Ln = Eu, Dy, Yb): a systematic study on the formation and crystal structures of new lanthanide thioantimonates(V).

New lanthanide thioantimonate(V) compounds, [Ln(en)3(H2O)x(mu(3-x)-SbS4)] (en = ethylenediamine, Ln = La, x = 0, Ia; Ln = Nd, x = 1, Ib) and [Ln(en)4]SbS4.0.5en (Ln = Eu, IIa; Dy, IIb; Yb, IIc), were synthesized under mild solvothermal conditions by reacting Ln2O3, Sb, and S in en at 140 degrees C. These compounds were classified as two types according to the molecular structures. The crystal structure of type I (Ia and Ib) consists of one-dimensional neutral [Ln(en)3(H2O)x(mu(3-x)-SbS(4))]infinity (x = 0 or 1) chains, in which SbS4(3-) anions act as tridentate or bidentate bridging ligands to interlink [Ln(en)3]3+ ions, while the crystal structure of type II (IIa, IIb, and IIc) contains isolated [Ln(en)4]3+ cations, tetrahedral SbS4(3-) anions, and free en molecules. A systematic investigation of the crystal structures of the five lanthanide compounds, as well as two reported compounds, clarifies the relationship between the molecular structure and the entity of the lanthanide(III) series, such as the stability of the lanthanide(III)-en complexes, the coordination number, and the ionic radii of the metals.

Journal Article↗
PubMed2005

Genome-wide analysis of mammalian DNA segment fusion/fission.

As a powerful tool for gene function prediction, gene fusion has been widely studied in prokaryotes and certain groups of eukaryotes, but it has been little applied in studies of mammalian genomes. With the first fully sequenced mammalian genomes (human, mouse, rat) now available, we defined and collected a set of fusion/fission event-linked segments (FFLS) based on structured organized genomic alignment. The statistics of the sequence features highlighted the FFLSs against their random context. We found that there are three groups of FFLSs with different component pairs (i.e. gene-gene, gene-noncoding and noncoding-noncoding) in all three mammalian genomes. The proteins encoded by the components of FFLSs in the first group shown a strong tendency to interact with each other. The segmental components in the last two groups which did not contain any protein-coding genes, were found not only to be transcribed to some level, but also more conserved than the random background. Thus, these segments are possibly carrying certain biologically functional elements. We propose that FFLS may be a potential tool for prediction and analysis of function and functional interaction of genetic elements, including both genes and noncoding elements, in mammalian genomes. The full list of the FFLSs in the genomes of the three mammals is available as supporting information at doi:10.1016/j.jtbi.2005.09.016.

Animals↗
PubMed2005

Simple sequence repeat-based consensus linkage map of Bombyx mori.

We established a genetic linkage map employing 518 simple sequence repeat (SSR, or microsatellite) markers for Bombyx mori (silkworm), the economically and culturally important lepidopteran insect, as part of an international genomics program. A survey of six representative silkworm strains using 2,500 (CA)n- and (CT)n-based SSR markers revealed 17-24% polymorphism, indicating a high degree of homozygosity resulting from a long history of inbreeding. Twenty-nine SSR linkage groups were established in well characterized Dazao and C108 strains based on genotyping of 189 backcross progeny derived from an F(1) male mated with a C108 female. The clustering was further focused to 28 groups by genotyping 22 backcross progeny derived from an F(1) female mated with a C108 male. This set of SSR linkage groups was further assigned to the 28 chromosomes (established linkage groups) of silkworm aided by visible mutations and cleaved amplified polymorphic sequence markers developed from previously mapped genes, cDNA sequences, and cloned random amplified polymorphic DNAs. By integrating a visible mutation p (plain, larval marking) and 29 well conserved genes of insects onto this SSR-based linkage map, a second generation consensus silkworm genetic map with a range of 7-40 markers per linkage group and a total map length of approximately 3431.9 cM was constructed and its high efficiency for genotyping and potential application for synteny studies of Lepidoptera and other insects was demonstrated.

Animals↗
PubMed2005

Quantitative molecular diagnosis of axillary drainage fluid for prediction of locoregional failure in patients with one to three positive axillary nodes after mastectomy without adjuvant radiotherapy.

PURPOSE: A quantitative multiple-marker reverse transcriptase (RT)-polymerase chain reaction (PCR) assay for sensitive detection of cancer cells in axillary drainage fluid was developed to examine whether the presence of cancer cells in axillary drainage fluid can be used as a predictor of locoregional recurrence (LRR) in patients with breast cancer who had T1/2 primary tumors and one to three positive axillary lymph nodes treated with modified radical mastectomy without adjuvant radiotherapy. METHODS AND MATERIALS: Axillary drainage fluid was collected from 126 patients with invasive ductal carcinoma of the breast who were treated with modified radical mastectomy and were found to have one to three positive axillary nodes. Cancer cells in axillary drainage fluid were detected by RT-PCR assay using primers specific for carcinoembryonic antigen (CEA) and cytokeratin-19 (CK-19) together with numerous clinicopathologic and treatment-related factors and were analyzed for their impact on LRR. RESULTS: A total of 38 patients suffered LRR during follow-up and the multimarker RT-PCR assays for CEA and CK-19 in the axillary drainage fluid both were positive in 34 patients (27.0%), of which 29 patients had LRR. In univariate analysis, the 5-year LRR-free survival showed higher rates in patients with PCR-negative findings in axillary drainage fluid (p<0.0001), age>or=40 years old (p<0.0001), tumor size<2.5 cm (p<0.0001), negative lymph-vascular space invasion (p=0.026), and T1 status (<0.0001); in multivariate analysis, PCR-positive findings together with age and tumor size were found to be independent predictors of LRR (all p<0.05). CONCLUSION: Multiplex RT-PCR assay for CEA and CK-19 was highly sensitive for detection and might be useful for prediction of LRR in such subgroup breast cancer patients.

Adult↗
PubMed2005

catena-poly[[[diaqua[trans-3-(4-pyridyl)acrylato]samarium(III)]-di-mu-trans-3-(4-pyridyl)acrylato] dihydrate].

In the title compound, {[Sm(4-pya)(3)(H(2)O)(2)].2H(2)O}(n) [4-pya is trans-3-(4-pyridyl)acrylate, C(8)H(6)NO(2)], each Sm(III) atom is ten-coordinated and has a bicapped square-antiprismatic coordination geometry. There is a crystallographic center of symmetry at the mid-point of the Sm...Sm line within each [Sm(4-pya)(3)(H(2)O)(2)](2) dimer. Each dimer is interconnected by two pairs of bridging 4-pya ligands to form a one-dimensional chain. Neighboring chains are connected via hydrogen bonds to form a three-dimensional network.

Journal Article↗
PubMed2005

Drosophila target of rapamycin kinase functions as a multimer.

Target of rapamycin (TOR) is a conserved regulator of cell growth and metabolism that integrates energy, growth factor, and nutrient signals. The 280-kDa TOR protein functions as the catalytic component of two large multiprotein complexes and consists of an N-terminal HEAT-repeat domain and a C-terminal Ser/Thr kinase domain. Here we describe an allelic series of mutations in the Drosophila Tor gene and show that combinations of mutations in the HEAT and kinase domains of TOR display the rare genetic phenomenon of intragenic complementation, in which two or more defective proteins assemble to form a functional multimer. We present biochemical evidence that TOR self-associates in vivo and show that this multimerization is unaffected by positive or negative signals upstream of TOR. Consistent with multimerization of TOR, recessive mutations in the HEAT and kinase domains can dominantly interfere with wild-type TOR function in cells lacking TSC1 or TSC2. TOR multimerization thus partially accounts for the high apparent molecular weight of TOR complexes and offers novel therapeutic strategies for pathologies stemming from TOR hyperactivity.

Alleles↗
PubMed2005

Surface modification of gold and quantum dot nanoparticles with chitosan for bioapplications.

Gold (Au) and quantum dot (QD) nanoparticles, which have been extensively used in many fields, were encapsulated with a natural polymer, chitosan, to improve their biocompatibility. Characterization was performed using ultraviolet-visible, dynamic light scattering, atomic force microscopy, and transmission electron microscope analyses. It was found that a Au/chitosan ratio of 1:1 and smaller produced chitosan-encapsulated Au nanoparticles of a sufficiently small size, and this result was then applied in the chitosan encapsulation of QDs. The biocompatibility of both types of nanoparticles was assessed in cell culture studies using HT29 human colon carcinoma and NIH 3T3 mouse fibroblast cells. MTT and trypan blue exclusion assays revealed that both chitosan-encapsulated Au nanoparticles and QDs exhibited improved biocompatibility over their bare, nonencapsulated counterparts. Therefore, this study showed that chitosan could be used to encapsulate both Au nanoparticles and QDs in order to enhance their biocompatibility. The approaches developed in this study can also be extended to other nanoparticles for bioapplications as well.

Animals↗