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Hao Li

Publications and source records attributed to Hao Li.

At least 109 records · Page 6Linked to original sources
PubMed2003

Naphthalene and anthracene mineralization linked to oxygen, nitrate, Fe(III) and sulphate reduction in a mixed microbial population.

A microbial consortium from a mixture of garden soil and an enrichment of a coal-tar contaminated sediment mineralized naphthalene and anthracene when oxygen, nitrate, Fe(III) (soluble and insoluble) or sulphate were provided as terminal electron acceptors (TEAs). Rates of polyaromatic hydrocarbon disappearance and mineralization were similar in the presence of oxygen and nitrate, and slower with the other TEAs. A maximum mineralization of 37.5% naphthalene and 8.5% anthracene occurred in 30 and 160 days respectively when oxygen was provided as the TEA. On the other hand, only 9.5% naphthalene and 3.2% anthracene were mineralized in 42 and 160 days respectively with FeOOH. Mineralization occurred only when a TEA was provided and ceased when the naphthalene concentration decreased to non-detectable levels (less than 0.008 micromoles/L), as measured by fluorescence spectroscopy. CH4 was not detected in the headspace of any microcosm. These results showed that mineralization of polyaromatic hydrocarbons such as naphthalene and anthracene can be linked to wide range of TEAs demonstrating that intrinsic polyaromatic hydrocarbon bioremediation is possible if any of these TEAs were available.

Anthracenes↗
PubMed2003

Mad2 and p53 expression profiles in colorectal cancer and its clinical significance.

AIM: To investigate the expression of tumor suppressor gene p53 and spindle checkpoint gene Mad2, and to demonstrate their expression difference in colorectal cancer and normal mucosa and to evaluate its clinical significance. METHODS: Western blot and immunohistochemistry methods were used to analyze the expression of Mad2 in colorectal cancer and its corresponding normal mucosa. The expression of p53 was detected by immunohistochemistry method in colorectal cancer and its corresponding normal mucosa. RESULTS: Mad2 was significantly overexpressed in colorectal cancer compared with corresponding normal mucosa (P<0.001), and it was not related to the differentiation of adenocarcinoma and other clinical factors (P>0.05). The ratio of Mad2 protein in cancer tissue (C) to that in its normal mucosa tissue (N) was higher than 2, which was more frequently observed in patients with lymph gland metastasis (P<0.05). p53 protein expression was not observed in normal mucosa. The rate of p53 positive expression in adenocarcinomas was 52.6 %. There was a significant difference between adenocarcinomas and normal mucosa(P<0.001), which was not related to the differentiation degree of adenocarcinoma and other clinical factors (P>0.05). CONCLUSION: Defect of spindle checkpoint gene Mad2 and mutation of p53 gene are involved mainly in colorectal carcinogenesis and C/N>2 is associated with prognosis of colorectal cancer.

Adenocarcinoma↗
PubMed2003

[Treatment of second primary malignant tumor induced by radiotherapy].

OBJECTIVE: To study the diagnosis and treatment of a second primary malignant tumor induced by previous radiotherapy. METHODS: From March 1970 to March 1997, 108 nasopharyngeal cancer (NPC) patients who developed a second primary malignant tumor induced by radiotherapy were treated. There were squamous carcinoma 43 (39.8%), sarcoma 26 (24.1%), malignant fibrous histiocytoma 14 (13.0%), adenoid cystic carcinoma 12 (11.1%), thyroid papillary adenocarcinoma 8 (7.4%) and malignant melanoma 5 (4.6%). Fifty patients underwent operation, 32 received radiotherapy, 18 received chemotherapy and 8 received operation combined with chemotherapy. RESULTS: The 3- and 5-year tumor-free survival rates were 64.0% and 36.0% in the operation group. They were 34.4% and 18.8% in the radiotherapy group. CONCLUSION: Surgery, if not contra-indicated, is the first choice for the second primary malignant tumor induced by radiotherapy. Aggressive treatment for these patients is, hence, indicated clinically.

Adult↗
PubMed2003

Group I mGluR ligands fail to affect 6-hydroxydopamine- induced death and glutamate release of PC12 cells.

AIM: To study the effect of group I metabotropic glutamate receptor (mGluR) ligands on 6-hydroxydopamine (6-OHDA)-induced death and glutamate release of PC12 cells. METHODS: PC12 cells were exposed to 100 micromol/L of group I mGluR agonist (RS)-3,5-dihydroxy-phenylglycine (DHPG) or antagonist DL-2-amino-3-phosphonopropionic acid (DL-AP3) 1 h before addition of 6-OHDA 100 micromol/L. After incubation for 24 h, morphological alterations were observed with microscope, DNA fragmentation was detected by terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) method, cytotoxicity was measured by MTT assay, and glutamate release was assayed by high performance liquid chromatography. RESULTS: 6-OHDA decreased cell viability (P<0.01) and induced concentration- and time-dependent glutamate release from PC12 cells. Group I mGluR ligands did not affect 6-OHDA-induced death of PC12 cells and had no influence on glutamate levels. CONCLUSION: Group I mGluR ligands cannot protect PC12 cells from 6-OHDA-induced death.

Adrenergic Agents↗
PubMed2003

[Effect of jiangya capsule on levels of serum nitric oxide synthase activity, malondialdehyde, plasma neuropeptide Y and homocysteine in patients with senile simple systolic hypertension].

OBJECTIVE: To observe the effect of Jiangya Capsule (JYC) on serum levels of nitric oxide synthase (NOS) activity and malondialdehyde (MDA), and plasma concentration of neuropeptide Y (NPY) and homocysteine (Hcy) in patients with senile simple systolic hypertension. METHODS: Randomized, double-blinded controlled method was adopted, the patients were divided into two groups, the treated group treated with JYC and the control group treated with Nimodipine. Changes of blood pressure, serum level of NOS and MDA, and plasma concentration of NPY and Hcy were observed. RESULTS: The effect of lowering blood pressure in the two groups were similar with insignificant difference (u = 0.24, P > 0.05). The total effective ratio in alleviating TCM syndrome was 90% (18/20) in the treated group and 60% (9/15) in the control group, comparison between them showed significant difference (u = 2.18, P < 0.05). After treatment, the NOS activity increased and MDA, NPY and Hcy levels decreased in the treated group, which showed significant difference as compared with those before treatment, and the improvement were better than those in the control group (all P < 0.05 or P < 0.01). While in the control group after treatment, only level of MDA was lowered significantly (P < 0.05). CONCLUSION: JYC has good effect in treating senile simple systolic hypertension, it also could increase the NOS activity, lower the serum MDA level, obviously reduce the plasma concentration of Hcy and NPY.

Aged↗
PubMed2003

Dynamic XML-based exchange of relational data: application to the Human Brain Project.

This paper discusses an approach to exporting relational data in XML format for data exchange over the web. We describe the first real-world application of SilkRoute, a middleware program that dynamically converts existing relational data to a user-defined XML DTD. The application, called XBrain, wraps SilkRoute in a Java Server Pages framework, thus permitting a web-based XQuery interface to a legacy relational database. The application is demonstrated as a query interface to the University of Washington Brain Project's Language Map Experiment Management System, which is used to manage data about language organization in the brain.

Brain↗
PubMed2003

[A rapid procedure to purify serum IgG from Microtus fotis].

OBJECTIVE: To evaluate the procedure to purify IgG antibodies from Microtus fotis serum. METHODS: IgG antibodies from sera of three groups of Microtus fotis were purified by protein G or protein A affinity chromatography, their purity and binding capacity were compared. RESULTS: The protein G affinity chromatography was more efficient than protein A affinity chromatography. The antibodies isolated from protein G affinity chromatography showed a higher purity and better activity than that from protein A affinity chromatography monitored by SDS-PAGE and ELISA. The ability of the purified IgG to bind the second antibodies were 8.5 times and 3.1 times that of non-IgG proteins and unpurified sera, respectively. CONCLUSION: The protein G affinity chromatography is a rapid, convenient and reliable procedure for Microtus fotis serum IgG purification.

Animals↗
PubMed2003

[Effect of ginsenoside Rg2 on chemical myocardial ischemia in rats].

OBJECTIVE: To investigate the protective effect of Ginsenoside Rg2 on Chemical myocardial ischemia. METHOD: The models of myocardial ischemia were built in rats with isoproterenol, sodium nitrite,pituitrin. Ginsenoside Rg2 (iv 2.5, 5.0, 10.0 mg x kg(-1)) were intravenously administered. RESULT: Ginsenoside Rg2 could improve the abnormal electrocardiogram (ECG), reduce the arca of myocardial ischemia and improve the abnormal zymologic value of myocardial. CONCLUSION: Ginsenoside Rg2 has inhibitory function on myocardialischemia.

Animals↗
PubMed2002

A systematic approach to reconstructing transcription networks in Saccharomycescerevisiae.

Decomposing regulatory networks into functional modules is a first step toward deciphering the logical structure of complex networks. We propose a systematic approach to reconstructing transcription modules (defined by a transcription factor and its target genes) and identifying conditionsperturbations under which a particular transcription module is activateddeactivated. Our approach integrates information from regulatory sequences, genome-wide mRNA expression data, and functional annotation. We systematically analyzed gene expression profiling experiments in which the yeast cell was subjected to various environmental or genetic perturbations. We were able to construct transcription modules with high specificity and sensitivity for many transcription factors, and predict the activation of these modules under anticipated as well as unexpected conditions. These findings generate testable hypotheses when combined with existing knowledge on signaling pathways and protein-protein interactions. Correlating the activation of a module to a specific perturbation predicts links in the cell's regulatory networks, and examining coactivated modules suggests specific instances of crosstalk between regulatory pathways.

Gene Expression Profiling↗
PubMed2002

Designability of protein structures: a lattice-model study using the Miyazawa-Jernigan matrix.

We study the designability of all compact 3 x 3 x 3 and 6 x 6 lattice-protein structures using the Miyazawa-Jernigan (MJ) matrix. The designability of a structure is the number of sequences that design the structure, i.e., sequences that have that structure as their unique lowest-energy state. Previous studies of hydrophobic-polar (HP) models showed a wide distribution of structure designabilities. Recently, questions were raised concerning the use of a two-letter (HP) code in such studies. Here, we calculate designabilities using all 20 amino acids, with empirically determined interaction potentials (MJ matrix) and compare with HP model results. We find good qualitative agreement between the two models. In particular, highly designable structures in the HP model are also highly designable in the MJ model-and vice versa-with the associated sequences having enhanced thermodynamic stability.

Amino Acids↗
PubMed2002

Reconstitution and characterization of the human DNA polymerase delta four-subunit holoenzyme.

Mammalian DNA polymerase delta was originally characterized as a tightly associated heterodimer consisting of the catalytic subunit, p125, and the p50 subunit. Recently, two additional subunits, the third (p68) and fourth subunits (p12), have been identified. The heterotetrameric human pol delta complex was reconstituted by overexpression of the four subunits in Sf9 cells, followed by purification to near-homogeneity using FPLC chromatography. The properties of the four-subunit enzyme were shown to be functionally indistinguishable from those of pol delta isolated from calf thymus. The physicochemical properties of both the reconstituted heterotetramer and the heterodimer of the p125 and p50 subunits were examined by gel filtration and glycerol gradient ultracentrifugation. These studies show quite clearly that the heterodimer and heterotetramer complexes do not behave in solution as dimeric structures. This issue is of significance because several studies of the yeast pol delta complexes have indicated that the third subunit is able to bring about the dimerization of the pol delta complex. The heterodimer is only weakly stimulated by PCNA, whereas the heterotetramer is strongly stimulated to a level with a specific activity comparable to that of the calf thymus enzyme. These results resolve earlier, conflicting reports on the response of the heterodimer to PCNA. Nevertheless, the heterodimer does have some ability to interact functionally with PCNA, consistent with evidence that the p125 subunit itself has an ability to interact with PCNA. The functional interaction of PCNA with the pol delta complex may likely involve multiple contacts.

Animals↗
PubMed2002

Identification of the binding sites of regulatory proteins in bacterial genomes.

We present an algorithm that extracts the binding sites (represented by position-specific weight matrices) for many different transcription factors from the regulatory regions of a genome, without the need for delineating groups of coregulated genes. The algorithm uses the fact that many DNA-binding proteins in bacteria bind to a bipartite motif with two short segments more conserved than the intervening region. It identifies all statistically significant patterns of the form W(1)N(x)W(2), where W(1) and W(2) are two short oligonucleotides separated by x arbitrary bases, and groups them into clusters of similar patterns. These clusters are then used to derive quantitative recognition profiles of putative regulatory proteins. For a given cluster, the algorithm finds the matching sequences plus the flanking regions in the genome and performs a multiple sequence alignment to derive position-specific weight matrices. We have analyzed the Escherichia coli genome with this algorithm and found approximately 1,500 significant patterns, which give rise to approximately 160 distinct position-specific weight matrices. A fraction of these matrices match the binding sites of one-third of the approximately 60 characterized transcription factors with high statistical significance. Many of the remaining matrices are likely to describe binding sites and regulons of uncharacterized transcription factors. The significance of these matrices was evaluated by their specificity, the location of the predicted sites, and the biological functions of the corresponding regulons, allowing us to suggest putative regulatory functions. The algorithm is efficient for analyzing newly sequenced bacterial genomes for which little is known about transcriptional regulation.

Algorithms↗
PubMed2002

Apolipoprotein B is synthesized in selected human non-hepatic cell lines but not processed into mature lipoprotein.

We studied apolipoprotein B100 (apoB) metabolism in a series of non-hepatic cell lines (HT29 colon adenocarcinoma, HeLa cervical epithelioid carcinoma, and 1321N1J astrocytoma human cell lines) and in the human hepatoma cell line HepG2. ApoB mRNA was detected by reverse transcription polymerase chain reaction in each non-hepatic cell line. ApoB was detected in HepG2 cells by immunoprecipitation, Western blotting, and immunocytochemistry using a polyclonal anti-human low-density lipoprotein (LDL) antibody, an anti-human apoB peptide antibody, and several monoclonal anti-apoB antibodies. ApoB was identified in the three non-hepatic cell lines by each method using the anti-apoB peptide and monoclonal antibodies, but not with the anti-LDL antibody. Immunocytochemistry indicated that epitopes of apoB were evident throughout the endoplasmic reticulum, and gel mobility of newly labeled apoB and immunoblot with anti-ubiquitin showed that apoB was highly ubiquinated in non-hepatic cells. The observations that apoB is synthesized in non-hepatic cell lines but never recognized by the anti-LDL antibody suggests that apoB is not processed into a nascent lipoprotein in these cells. Immunocytochemical localization of apoB epitopes at many locations throughout non-hepatic cells raises the exciting possibility that apoB can be used for other purposes in these cells.

Apolipoprotein B-100↗
PubMed2002

intersex, a gene required for female sexual development in Drosophila, is expressed in both sexes and functions together with doublesex to regulate terminal differentiation.

Previous genetic studies indicated intersex (ix) functions only in females and that it acts near the end of the sex determination hierarchy to control somatic sexual differentiation in Drosophila melanogaster. We have cloned ix and characterized its function genetically, molecularly and biochemically. The ix pre-mRNA is not spliced, and ix mRNA is produced in both sexes. The ix gene encodes a 188 amino acid protein, which has a sequence similar to mammalian proteins thought to function as transcriptional activators, and a Caenorhabditis elegans protein that is thought to function as a transcription factor. Bringing together the facts that (1) the ix phenotype is female-specific and (2) functions at the end of the sex determination hierarchy, yet (3) is expressed sex non-specifically and appears likely to encode a transcription factor with no known DNA-binding domain, leads to the inference that ix may require the female-specific protein product of the doublesex (dsx) gene in order to function. Consistent with this inference, we find that for all sexually dimorphic cuticular structures examined, ix and dsx are dependent on each other to promote female differentiation. This dependent relationship also holds for the only known direct target of dsx, the Yolk protein (Yp) genes. Using yeast 2-hybrid assay, immunoprecipitation of recombinant tagged IX and DSX proteins from Drosophila S2 cell extracts, and gel shifts with the tagged IX and DSX(F) proteins, we demonstrate that IX interacts with DSX(F), but not DSX(M). Taken together, the above findings strongly suggest that IX and DSX(F) function in a complex, in which IX acts as a transcriptional co-factor for the DNA-binding DSX(F).

Alternative Splicing↗
PubMed2002

Effect of NF-kappaB on the induction of PDGF-B transcription by angiotensin II in the ECV304 cell line.

OBJECTIVE: To examine the effect of angiotensin II (Ang II) on nuclear factor-kappa B (NF-kappaB) activation in human endothelial cell line ECV304 and the molecular mechanism by which Ang II activates NF-kappaB. METHODS: ECV304 cells were transiently cotransfected with an NF-kappaB/luciferase reporter gene and inactive NF-kappaB-inducing kinase (NIK), IkappaB kinase alpha (IKK(alpha)), IkappaB kinase beta (IKK(beta)) mutants or vectors, respectively. The effect on NF-kappaB was detected by using an electrophoretic mobility shift assay (EMSA) and overexpression of the mutants enabled blocking of reporter gene activation induced by Ang II. With immunofluorescence and immuno-electronic microscope techniques, including confocal microscopy and gold particle labeled electronic microscopy, definite cytoplasmic-to-nuclear translocations of NF-kappaB activation were detected using subunits p50 and p65 induced by Ang II. RESULTS: The translocation of p50 in nuclei was highly remarkable 2 hours after Ang II stimulation, and the activity was somewhat reduced 6 hours after stimulation to the 18th hour. Northern blot also showed PDGF-B mRNA increased by stimulation of Ang II for 18 hours. CONCLUSION: Ang II is effective in stimulating NF-kappaB activation through a pathway dependent on NIK, IKK(alpha) and IKK(beta), and induces PDGF-B transcription in the endothelial cell line, ECV304.v

Angiotensin II↗
PubMed2002

[Indication and clinical radical effect of functional neck dissection for head and neck neoplasm].

BACKGROUND & OBJECTIVE: The functional neck dissection was first described by Bocca in 1967. It has been used on clinical practice for years. But still controversial between supporters and opponents of functional neck dissection. This study was designed to evaluate application and radical effectiveness of functional neck dissection(FND). METHODS: One hundred and fifty-two cases underwent FND were reviewed with analysis of pathological specimen and follow-up data. RESULT: One hundred and fifty-two cases of FND include tongue carcinoma 20 cases, larynx carcinoma 23 cases, thyroid papillary adenocarcinoma 96 cases, follicular adenocarcinoma 9 cases, medullary adenocarcinoma 4 cases; Five years recurrence rate of tongue and larynx carcinoma was 12.5%, 14.3%, 40.0% and 20%, 16.7%, 50.0% in N0, N1, N2, respectively. 5 years recurrence rate of thyroid papillary adenocarcinoma is 6.5%, 7.1% in N1a, N1b, respectively. CONCLUSION: Functional neck dissection is suitable for head and neck neoplasm, was result in satisfactory radical effects.

Adenocarcinoma, Follicular↗