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Biomedical subjects

Gang Liu

Publications and source records attributed to Gang Liu.

At least 127 records · Page 7Linked to original sources
PubMed2005

[Protective effects of Salvia miltiorrhiza on rats with streptozotocin diabetes and its mechanism].

OBJECTIVE: To explore the effects of Salvia miltiorrhiza on renal morphology and renal function of rats with streptozotocin diabetes. METHODS: Thirty male Wistar rats were randomly divided into three groups, which were normal control group, untreated group and Salvia miltiorrhiza-treated group. Diabetic nephropathy was induced in rats of the last two groups by intraperitoneal injection of streptozotocin after unilateral nephrectomy. Then the rats in the normal control and untreated groups were fed with normal saline while those in the Salvia miltiorrhiza-treated group were fed Salvia miltiorrhiza preparation for 8 weeks. The glomerular volume (VG), kidney-to-body weight ratio (KW/BW), urinary albumin excretion rate (UAER) and creatinine clearance (Ccr) were observed. The expression levels of transforming growth factor-beta1 (TGF-beta1), connective tissue growth factor (CTGF), fibronectin (FN) and plasminogen activator inhibitor-1 (PAI-1) were detected by real-time quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) at the end of the experiment. RESULTS: UAER, Ccr, VG and KW/BW ratio were significantly higher in the untreated group than those in the normal control group (P<0.05). The expression levels of TGF-beta1, CTGF, PAI-1 and FN in the untreated group were also significantly higher as compared with those in the normal control group (P<0.05). UAER, Ccr, VG, KW/BW ratio and the levels of TGF-beta1, CTGF, PAI-1 and FN in the Salvia miltiorrhiza-treated group were obviously lower than those in the untreated group (P<0.05). CONCLUSION: Salvia miltiorrhiza can protect rats with streptozotocin diabetes from diabetic nephropathy by suppressing the over-expressions of TGF-beta1, CTGF, PAI-1 and FN in renal cortex.

Animals↗
PubMed2005

[Clinical observation on acupuncture combined with music for treatment of Alzheimer disease].

OBJECTIVE: To find the method for increasing clinical therapeutic effect on Alzheimer disease (AD). METHODS: The patients of AD meeting American NINCDS-ADRDA Criteria were randomly divided into group A and group B. The group A (n = 21) were treated with acupuncture for 10 courses, 10 sessions constituting one course; and the group B (n = 20) were treated with combination of acupuncture and music therapy. The acupuncture method was the same as the group A and the music therapy was given for 20 sessions, once every 5 days. After treatment, their effectiveness were evaluated with the Mini-Mental State Examination (MMSE) and Activities of Daily Living (ADL). RESULTS: After treatment, the scores for MMSE increased significantly (P < 0.05) and the scores for ADL decreased significantly (P < 0.05) in the both groups, and the therapeutic effect in the group A was better than the group B (P < 0.05). CONCLUSION: Acupuncture combined with music therapy can increase the therapeutic effect on AD.

Activities of Daily Living↗
PubMed2005

[A cross-sectional study on prevalance and risk factors of disabilities in aged 0-6 years children in Beijing, China].

OBJECTIVE: To explore the epidemiological status of disabilities on vision impairment (VI), hearing loss (HL), mental retardation (MR), autism spectrum disorder (ASD) and motor disorder (MD) in aged 0-6 years old children in Beijing. METHODS: A total of 28 738 children under 7 years old were recruited from permanent residents of Beijing City by 2-phase cluster sampling. The screening procedure was 2-phase, and the diagnosis criteria were developed by the experts group. RESULTS: The overall disability rate was 11.45 per thousand (95 % CI:10.22-12.68). The false negative rates in HL and ASD were 0.14 per thousand, 0.80 per thousand, respectively, with a adjusted overall rate of 12.19per thousand. The prevalence rates of different kind disabilities from high to low were MR 9.31per thousand, MD 2.12per thousand, ASD 1.53per thousand (0.73per thousand before adjusted), HL 1.04per thousand (0.91per thousand before adjusted) VI 0.73per thousand. The results of logistic regression analysis showed that the possible non-biological risk factors for those disabilities were being male, living in city area, advancing age, mother with low education, mother engaged in labor work, and family with low income. It was primarily (49.62%) those prenatal factors other them the known suspected factors that causing disabilities. CONCLUSIONS: Compared with data from a countrywide study in 1987, the overall disability rate had a mild decrease (16.36%) with the most (56.85%) appeared in HL. It is indispensable to establish a disabilities surveillance program for the early recognition and intervention of children with disabilities. It is also crucial to clarify a disability definition for children combined with their characteristics of growth and development. We strongly recommended in developing a new definition on children' disabilities and establishing new criteria according to the contents of developmental disabilities of Center for Disease Control, USA.

Age Distribution↗
PubMed2005

[Study on preparation and spectroscopy of silica-alumina hydrogel and silica from kaolin].

In our research, silica-alumina hydrogel was prepared by activation with NaOH and reaction with HCl from kaolin, and silica was obtained from the hydrogel by drying and acidifying with HCl. IR, XRD and XRF were used for testing the results, and better result was obtained. The optimal conditions of processing for kaolin 40 g were 15-20 g of sodium hydroxide and 4-5 mol x L(-1) of hydrochloric acid. Finally, preparation processing to get silica, as well as the structure and purity of the resulting silica were characterized by means of IR, XRD and XRF.

Aluminum Oxide↗
PubMed2004

Discovery of tetralin carboxamide growth hormone secretagogue receptor antagonists via scaffold manipulation.

A case study of rational design of an efficient, specific, and proprietary molecular scaffold based on the structure-activity relationship (SAR) information on a screening hit is described. Potent, selective, and orally bioavailable tetralin carboxamide growth hormone secretagogue receptor (GHS-R) antagonists were discovered. Union of rational design and high throughput synthesis provided a quick access to high quality chemical leads.

Drug Design↗
PubMed2004

Isoxazole carboxylic acids as protein tyrosine phosphatase 1B (PTP1B) inhibitors.

Guided by X-ray crystallography, we have extended the structure-activity relationship (SAR) study on an isoxazole carboxylic acid-based PTP1B inhibitor (1) and more potent and equally selective (>20-fold selectivity over the highly homologous T-cell PTPase, TCPTP) PTP1B inhibitors were identified. Inhibitor 7 demonstrated good cellular activity against PTP1B in COS 7 cells.

Animals↗
PubMed2004

Sensitivity, principal component and flux analysis applied to signal transduction: the case of epidermal growth factor mediated signaling.

MOTIVATION: Novel high-throughput genomic and proteomic tools are allowing the integration of information from a range of biological assays into a single conceptual framework. This framework is often described as a network of biochemical reactions. We present strategies for the analysis of such networks. RESULTS: The direct differential method is described for the systematic evaluation of scaled sensitivity coefficients in reaction networks. Principal component analysis, based on an eigenvalue-eigenvector analysis of the scaled sensitivity coefficient matrix, is applied to rank individual reactions in the network based on their effect on system output. When combined with flux analysis, sensitivity analysis allows model reduction or simplification. Using epidermal growth factor (EGF) mediated signaling and trafficking as an example of signal transduction, we demonstrate that sensitivity analysis quantitatively reveals the dependence of dual-phosphorylated extracellular signal-regulated kinase (ERK) concentration on individual reaction rate constants. It predicts that EGF mediated reactions proceed primarily via an Shc-dependent pathway. Further, it suggests that receptor internalization and endosomal signaling are important features regulating signal output only at low EGF dosages and at later times.

Algorithms↗
PubMed2004

Novel isoxazole carboxamides as growth hormone secretagogue receptor (GHS-R) antagonists.

Novel isoxazole carboxamides have been identified as growth hormone secretagogue receptor (GHS-R) antagonists. Substituent modification off the 5-position of the isoxazole ring led to analogues with potent binding affinity and functional antagonism of GHS-R. A potent analogue (32) with high aqueous solubility and good GPCR selectivity was also identified as a potential pharmacological tool for in vivo studies.

Amides↗
PubMed2004

Gene expression profiling of human lung tissue from smokers with severe emphysema.

The mechanism by which inhaled smoke causes the anatomic lesions and physiologic impairment of chronic obstructive pulmonary disease remains unknown. We used high-density microarrays to measure gene expression in severely emphysematous lung tissue removed from smokers at lung volume reduction surgery (LVRS) and normal or mildly emphysematous lung tissue from smokers undergoing resection of pulmonary nodules. Class prediction algorithms identified 102 genes that accurately distinguished severe emphysema from non-/mildly emphysematous lung tissue. We also defined a number of genes whose expression levels correlated strongly with lung diffusion capacity for carbon monoxide and/or forced expiratory volume at 1 s. Genes related to oxidative stress, extracellular matrix synthesis, and inflammation were increased in severe emphysema, whereas expression of endothelium-related genes was decreased. To identify candidate genes that might be causally involved in the pathogenesis of emphysema, we linked gene expression profiles to chromosomal regions previously associated with chronic obstructive pulmonary disease in genome-wide linkage analyses. Unsupervised hierarchical clustering of the LVRS samples revealed distinct molecular subclasses of severe emphysema, with body mass index as the only clinical variable that differed between the groups. Class prediction models established a set of genes that predicted functional outcome at 6 mo after LVRS. Our findings suggest that the gene expression profiles from human emphysematous lung tissue may provide insight into pathogenesis, uncover novel molecular subclasses of disease, predict response to LVRS, and identify targets for therapeutic intervention.

Aged↗
PubMed2004

The behavior of mixed-metal oxides: physical and chemical properties of bulk Ce1-xTbxO2 and nanoparticles of Ce1-xTbxOy.

The physical and chemical properties of bulk Ce(1-x)Tb(x)O(2) and Ce(1-x)Tb(x)O(y) nanoparticles (x Tb exchange nor the introduction of oxygen vacancies in Ce(1-x)Tb(x)O(y) significantly affect the charge on the Ce cations. In contrast, the O K-edge and Tb L(III)-edge XANES spectra for Ce(1-x)Tb(x)O(y) nanoparticles show substantial changes with respect to the corresponding spectra of Ce and Tb single oxide references. The Ce(0.5)Tb(0.5)O(y) compounds exhibit a much larger Tb(3+)/Tb(4+) ratio than TbO(1.7). A comparison with the properties of Ce(1-x)Zr(x)O(y) and Ce(1-x)Ca(x)O(y) shows important differences in the charge distribution, the magnitude of the dopant induced strain in the oxide lattice, and a superior behavior in the case of the Ce(1-x)Tb(x)O(y) systems. The Tb-containing oxides combine stability at high temperature against phase segregation and a reasonable concentration of O vacancies, making them attractive for chemical and catalytic applications.

Journal Article↗
PubMed2004

[Total cyst excision with ultrasonic scalpel under the laparoscope for choledochal cyst].

OBJECTIVE: To discuss the technique and its advantage on application of ultrasonic scalpel in laproscopic cyst excision with Roux-en-Y hepatoenterostomy. METHODS: Forty-five cases were undergone laparoscopic cyst excision with Roux-en-Y hepatoenterostomy by ultrasonic scalpel. After intraoperative cholangiogram, the gallbladder and the dilated bile duct were completely excised by ultrasonic scalpel. Roux-en-Y hepatoenterostomy was performed extracorporeally through umbilical incision, then an end-to-side anastomosis was carried out intracorporeally. RESULTS: All 45 cases were completely accomplished under laparoscope combined with ultrasonic scalpel. Median duration of operation was 4.2 h (3.5-6.0 h). Intraoperative bleeding was between 10-50 ml (median 15 ml). No complication were found during operation. All children were discharged in 3-9 d (median 5.5 d) after operation. Thirty-eight cases were followed up 1-18 months. No stenosis or ileus occurred. Liver functions were in normal level. CONCLUSIONS: Total cyst excision with Roux-en-Y hepatoenterostomy by ultrasonic scalpel under the laparoscope was effective and safe for choledochal cyst. The most excellence was that clearly viewing during operation, less bleeding and injury, free of pain postoperation, microincision and scar.

Anastomosis, Roux-en-Y↗
PubMed2004

Determinants of retinoid X receptor transcriptional antagonism.

The synthesis and bioactivity of the retinoid X receptor (RXR) antagonist 4-[(3'-n-butyl-5',6',7',8'-tetrahydro-5',5',8',8'-tetramethyl-2'-naphthalenyl)(cyclopropylidene)methyl]benzoic acid and several heteroatom-substituted analogues are described. Ligand design was based on the scaffold of the 3'-methyl RXR-selective agonist analogue and reports that 3'-n-propyl and longer n-alkyl groups conferred RXR antagonism. The transcriptional antagonism of the 3'-n-butyl analogue was demonstrated by its blockade of retinoic acid receptor (RAR) beta expression induced by the RXRalpha/peroxisome proliferator-activated receptor (PPAR) gamma heterodimer complexed with an RXRalpha agonist plus the PPARgamma agonist ciglitazone and the inhibition of 9-cis-RA-induced coactivator SRC-1a recruitment to RXRalpha. Receptor-ligand docking studies using full-atom flexible ligand and flexible receptor suggested that binding of the antagonist to the RXRalpha antagonist conformation was favored because the salt bridge that formed between the retinoid carboxylate and the RXRalpha helix H5 arginine-321 was far stronger than that formed on its binding to the agonist conformation. The antagonist also blocked activation of RAR subtypes alpha and beta by 9-cis-RA but not that of RARgamma.

Benzoates↗
PubMed2004

ERbeta exerts multiple stimulative effects on human breast carcinoma cells.

Recent studies of ERs in breast cancer have demonstrated the existence of ERbeta in addition to ERalpha. Some clinical data indicated that ERbeta had prognostic value for patient's survival, which suggested that ERbeta plays a key role in breast cancer development and metastasis. To test this hypothesis, we generated an ERbeta high-expression cell line by reintroduced human ERbeta cDNA into MDA-MB-435 cells. We demonstrated that ERbeta exerted multiple tumor-stimulative effects on human breast carcinoma cells both in vivo and in vitro. In in vitro studies, ERbeta was able to increase the proliferation and invasion of MDA-MB-435 cells significantly, while these effects were totally estradiol independent. Also, this stimulation was characterized by downregulation of p21 and upregulation of MMP-9, as well as transcriptional factor Est-1. In in vivo studies, we also demonstrated that ERbeta-transfected MDA-MB-435 cells grew much faster and had more pulmonary metastasis than mock or wild-type cells in nude mice. In ERbeta-transfected MDA-MB-435 xenografts, ERbeta caused significant reduction in p21 protein levels. Similar effects of ERbeta on MMP-9 and Ets-1 expression noted in vitro studies were also observed in the in vivo studies. These in vitro and in vivo studies indicated that ERbeta exerted multiple stimulative effects on breast cancer development and metastasis.

Animals↗
PubMed2004

Antagonist analogue of 6-[3'-(1-adamantyl)-4'-hydroxyphenyl]-2-naphthalenecarboxylic acid (AHPN) family of apoptosis inducers that effectively blocks AHPN-induced apoptosis but not cell-cycle arrest.

The retinoid 6-[3'-(1-adamantyl)-4'-hydroxyphenyl]-2-naphthalenecarboxylic acid (AHPN) and its active analogues induce cell-cycle arrest and programmed cell death (apoptosis) in cancer cells independently of retinoic acid receptor (RAR) interaction. Its analogue, (E)-4-[3'-(1-adamantyl)-4'-hydroxyphenyl]-3-(3'-acetamidopropyloxy)cinnamic acid (3-A-AHPC) selectively antagonized cell apoptotic events (TR3/nur77/NGFI-B expression and nuclear-to-mitochondrial translocation) but not the proliferative events (cell-cycle arrest and p21(WAF1/CIP1) expression) induced by proapoptotic AHPN and its analogues. The syntheses of 3-A-AHPC and proapoptotic (E)-6-[3'-(1-adamantyl)-4'-hydroxyphenyl]-5-chloronaphthalenecarboxylic acid (5-Cl-AHPN) are described. Computational studies on AHPN, AHPC, and three substituted analogues (5-Cl-AHPN, 3-Cl-AHPC, and 3-A-AHPC) suggested reasons for their diametric effects on RAR activation. Density functional theory studies indicated that the 1-adamantyl (1-Ad) groups of the AHPN and AHPC configurations assumed positions that were nearly planar with the aromatic rings of their polar termini. In contrast, in the configurations of the substituted analogues having chloro and 3-acetamidopropyloxy groups, rather than a hydrogen, ortho to the diaryl bonds, the diaryl bond torsion angles increased so that the 1-Ad groups were oriented out of this plane. Docking and molecular dynamics of AHPN, AHPC, and these substituted analogues in the RARgamma ligand-binding domain illustrated how specific substituents on the AHPN and AHPC scaffolds modulated the positions and dynamics of the 1-Ad groups. As a result, the position of RARgamma helix H12 in forming the coactivator-binding site was impacted in a manner consistent with the experimental effect of each analogue on RARgamma transcriptional activation.

Adamantane↗
PubMed2004

Effects of cigarette smoke on the human airway epithelial cell transcriptome.

Cigarette smoke is the major cause of lung cancer, the leading cause of cancer death, and of chronic obstructive pulmonary disease, the fourth leading cause of death in the United States. Using high-density gene expression arrays, we describe genes that are normally expressed in a subset of human airway epithelial cells obtained at bronchoscopy (the airway transcriptome), define how cigarette smoking alters the transcriptome, and detail the effects of variables, such as cumulative exposure, age, sex, and race, on cigarette smoke-induced changes in gene expression. We also determine which changes in gene expression are and are not reversible when smoking is discontinued. The persistent altered expression of a subset of genes in former smokers may explain the risk these individuals have for developing lung cancer long after they have discontinued smoking. The use of gene expression profiling to explore the normal biology of a specific subset of cells within a complex organ across a broad spectrum of healthy individuals and to define the reversible and irreversible genetic effects of cigarette smoke on human airway epithelial cells has not been previously reported.

Bronchi↗
PubMed2004

Cloning of a full-length cDNA of human testis-specific spermatogenic cell apoptosis inhibitor TSARG2 as a candidate oncogene.

A novel human gene full-length cDNA sequence-TSARG2 was identified from a human testis cDNA library using the SRG2 gene (GenBank Accession No. ), which was significantly up-regulated in cryptorchidism, as an electronic probe. TSARG2 was 1223 bp in length. The putative protein encoded by this gene was 305 amino acids with a theoretical molecular weight of 34,751 and isoelectric point of 9.85. The sequence shared no significant homology with any known protein in databases except SRG2. Northern blot analysis revealed that 1.7 kb TSARG2 transcript was detected selectively in human testis. Furthermore, results of in situ hybridization assay confirmed that TSARG2 was expressed in seminiferous tubules, more precisely in spermatogonia and spermatocyte. No mutation was found by PCR-SSCP in 122 cases of azoospermia, severe oligzoospermia, and cryptorchidism. The green fluorescence produced by pEGFP-C1/TSARG2 was detected on the nucleus of COS7 cells after 24h post-transfection. The pcDNA3.1(-)/TSARG2 plasmid was constructed and introduced into MCF7 cells by liposome transfection. TSARG2 can accelerate MCF7 cells to traverse the S-phase and enter the G2-phase compared with the control without transfection of TSARG2, which suggested that this gene plays an important role in the development of cryptorchid testis and is a testis-specific apoptosis candidate oncogene.

Amino Acid Sequence↗
PubMed2004

[Effects of icariin on the erectile function and expression of nitrogen oxide synthase isoforms in corpus cavernosum of arterigenic erectile dysfunction rat model].

OBJECTIVE: The study the effects of oral administered icariin on intracavernosal pressure (ICP) and on expression of the nitrogen oxide synthase (NOS) isoforms in corpus cavernosum (CC) of arteriogenic erectile dysfunction (A-ED) rat model. METHODS: Forty adult male Wistar rats were randomly divided into 4 groups of 10 rats: shame operated group (group A) and three A-ED model groups (group B, C and D). The internal pudendal arteries were isolated and ligated with 7-O nylon thread at both the main trunk and the penile branches to establish the A-ED model. ICP were tested after the operation to make sure the successful model establishment. The groups A and B were treated with saline: and the groups C and D were treated with icariin (5 mg/kg/day and 10mg/kg/day respectively) orally for 30 days. Then the ICP was measured again. The tissues of corpus cavernosum were taken and RT-PCR was used to detect the mRNA expression of nNOS, iNOS and eNOS in CC, and Western-blot was used to detect the protein expression of these NOS isoforms. RESULTS: The ICP in the group B was significantly decreased compared to the group A (P < 0.01), but the ICP values in the groups C and D were both increased compared to those in the group B (both P < 0.01). The expressions of the mRNA and protein of nNOS, iNOS, and eNOS were all decreased in the group B, however, the mRNA and protein expressions of eNOS were increased a in the groups C and D. In the group C, iNOS also increased. The expression of nNOS showed no obvious changes in the group C and group D. CONCLUSION: Chronic oral treatment with Icariin increases the erectile function (ICP) and restores the eNOS expression in CC of A-ED rats. Icariin may have a long-term therapeutic effect on ischemia/hypoxia induced ED.

Animals↗