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Chao Liu

Publications and source records attributed to Chao Liu.

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

STR data for the 15 loci from three minority populations in Guangxi municipality in South China.

In this study, allele frequencies for the 15 STRs (D8S1179, D21S11, D7S820, CSF1PO, D3S1358, TH01, D13S317, D16S539, D2S1338, D19S433, vWA, TPOX, D18S51, D5S818, FGA) included in the AmpFLSTR Identifiler kit were obtained from total of 450 unrelated individuals belonging to three minority populations including Miao (n=141), Yi (n=165) and Hui (n=144) in Guangxi municipality, South China. GENEPOP v3.4 and PowerStats v1.2 was used to analyze the genotype data. This result indicates that the studied STR loci of these three minorities are useful in forensic testing and population genetics studies.

China↗
PubMed2006

Genetic diversity at 15 STR loci in two tribal populations in Southern China.

In this research, the allelic distribution of 15 tetrameric short tandem repeats (STR) loci (D8S1179, D21S11, D7S820, CSF1PO, D3S1358, TH01, D13S317, D16S539, D2S1338, D19S433, vWA, TPOX, D18S51, D5S818, FGA) were obtained from 167 Mulao and 108 Maonan unrelated individuals. The Genepop v3.4 and the PowerStats v1.2 were used to perform statistical tests and to calculate the forensic parameters. All loci of the two populations showed no significant deviation from Hardy-Weinberg equilibrium. The results showed the 15 STR loci of the two populations have a high degree of genetic polymorphism.

China↗
PubMed2006

Characterization of Spodoptera exigua multicapsid nucleopolyhedrovirus ORF100 and ORF101, two homologues of E. coli ChaB.

ChaB, a putative regulator of ChaA in Escherichia coli (E. coli), and its homologues constitute a multigene family known to occur among bacteria, archaeabacteria and baculoviruses. The baculovirus Spodoptera exigua multicapsid nucleopolyhedrovirus contains two homologues of E. coli ChaB, open reading frames (ORFs) 100 (Se100) and 101 (Se101). RT-PCR and 5' RACE analyses indicated that transcription of both SeMNPV chaB genes occurs by 24 h postinfection and is initiated at a late consensus ATAAG motif. Immunoblot analysis showed that Se100 and Se101 were, respectively, expressed as 11 and 28kDa proteins in infected cells, and they were distributed in both cytoplasm and nucleus. Further analysis revealed that Se100 and Se101 are associated with nuclear structure and only present in the nucleocapsid of occlusion-derived virus. Additionally, column chromatography analysis showed that both proteins could weakly interact with nucleic acids. It was proposed that SeMNPV ChaB might function as DNA binding proteins.

Amino Acid Sequence↗
PubMed2006

Phytotoxic effects of copper on nitrogen metabolism and plant growth in Brassica pekinensis Rupr.

Copper (Cu) from various anthropogenic and natural sources is one of the major heavy metal contaminants in the environment. To study Cu-induced nitrogen (N) metabolism damage in the popular vegetable Chinese cabbage (Brassica pekinensis Rupr.), aquatic culture experiments with this plant were performed. Two Cu levels (0.3 micromol/L (control) and 10.3 micromol/L) and two N levels (0.05- and 1-fold Hoagland's solution) were used for the aquatic culture experiments. The results demonstrated adverse effects of Cu on N metabolism and plant growth. Cu exposure elevated Cu concentration and decreased nitrate reductase (NR) activity in the roots and shoots and reduced total chlorophyll content. It also shortened root length and produced fewer leaves and lower plant biomass. However, Cu exposure increased total free amino acid content in the leaves. The results also demonstrated effects of N deficiency on N metabolism and plant growth. N deficiency increased the root/shoot ratio of biomass and the total free amino acid content and decreased the nitrate contents and NR activity in roots and leaves. In addition, there were interactive effects between Cu exposure and N level on plant biomass, root/shoot ratio, and chlorophyll and nitrate content in leaves. The results suggested that Cu toxicity to the plant was at least partly due to an influence on N metabolism.

Amino Acids↗
PubMed2006

In situ characterization of lipid A interaction with antimicrobial peptides using surface X-ray scattering.

Lipid A structure at the air-aqueous interface has been studied using pressure-area isotherm methods coupled with the surface X-ray scattering techniques of X-ray reflectivity (XR) and grazing incidence X-ray diffraction (GIXD). Lipid A monolayers were formed at the air-aqueous interface to represent the lipid moiety of the outer membrane of Gram-negative bacteria. Lipid A structure was characterized at surface pressures between 10 and 35 mN/m. Interactions of alpha-helical antimicrobial peptides LL-37, SMAP-29 and D2A22 with lipid A monolayers were subsequently studied. Although insertion into the lipid A monolayers was observed with the alpha-helical peptides, little change was seen from the X-ray data, suggesting that the lipid A hydrocarbon chains are involved in reorientation during insertion and that the hydrocarbon chains have a relatively rigid structure.

Amino Acid Sequence↗
PubMed2006

Treatments for pulmonary arterial hypertension.

Pulmonary arterial hypertension (PAH) is a devastating disease that leads to right heart failure and premature death. Historically, we are restricted by limited options for drug treatment. Over the past decade, with advances in our understanding of pathophysiological and molecular mechanisms, many new therapeutic strategies (synthetic prostacyclin and prostacyclin analogues, endothelin receptor antagonists and sildenafil) have been developed for the treatment of PAH, and the clinical efficacy has been tested in many randomized-controlled trials (RCTs). In this overview, we review the evidence for the use of historical and new treatments that arises from the Cochrane Collaboration of Systematic Reviews and from recent RCTs.

Antihypertensive Agents↗
PubMed2006

Effect of Nd3+ ion on carboxylation activity of ribulose-1,5-bisphosphate carboxylase/oxygenase of spinach.

Neodymium (Nd), as a member of rare earth elements, proved to enhance the photosynthesis rate and organic substance accumulation of spinach through the increase in carboxylation activity of Rubisco. Although the oxygenase activity of spinach Rubisco was slightly changed with the Nd(3+) treatment, the specific factor of Rubisco was greatly increased. It was partially due to the promotion of Rubisco activase (R-A) activity but mainly to the formation of Rubisco-Rubisco activase super-complex, a heavier molecular mass protein (about 1200kD) comprising both Rubisco and Rubisco activase. This super-complex was found during the extraction procedure of Rubisco by the gel electrophoresis and Western-blot studies. The formation of Rubisco-R-A super-complex suggested that the secondary structure of the protein purified from the Nd(3+)-treated spinach was different from that of the control. Extended X-ray absorption fine structure study of the 'Rubisco' purified from the Nd(3+)-treated spinach revealed that Nd was bound with four oxygen atoms and two sulfur atoms of amino acid residues at the Nd-O and Nd-S bond lengths of 2.46 and 2.89A, respectively.

Cations↗
PubMed2006

Application of lentivirus-mediated RNAi in studying gene function in mammalian tooth development.

RNA interference (RNAi) has recently become a powerful tool to silence gene expression in mammalian cells, but its application in assessing gene function in mammalian developing organs remains highly limited. Here we describe several unique developmental properties of the mouse molar germ. Embryonic molar mesenchyme, but not the incisor mesenchyme, once dissociated into single cell suspension and re-aggregated, retains its odontogenic potential, the capability of a tissue to instruct an adjacent tissue to initiate tooth formation. Dissociated molar mesenchymal cells, even after being plated in cell culture, retain odontogenic competence, the capability of a tissue to respond to odontogenic signals and to support tooth formation. Most interestingly, while dissociated epithelial and mesenchymal cells of molar tooth germ are mixed and re-aggregated, the epithelial cells are able to sort out from the mesenchymal cells and organize into a well-defined dental epithelial structure, leading to the formation of a well-differentiated tooth organ after sub-renal culture. These unique molar developmental properties allow us to develop a strategy using a lentivirus-mediated RNAi approach to silence gene expression in dental mesenchymal cells and assess gene function in tooth development. We show that knockdown of Msx1 or Dlx2 expression in the dental mesenchyme faithfully recapitulates the tooth phenotype of their targeted mutant mice. Silencing of Barx1 expression in the dental mesenchyme causes an arrest of tooth development at the bud stage, demonstrating a crucial role for Barx1 in tooth formation. Our studies have established a reliable and rapid assay that would permit large-scale analysis of gene function in mammalian tooth development.

Animals↗
PubMed2006

In vitro and in vivo evaluation of ultrananocrystalline diamond for coating of implantable retinal microchips.

In this work, ultrananocrystalline diamond (UNCD) thin films were evaluated for use as hermetic and bioinert coatings for a retinal microchip. These films were deposited on highly conductive Si substrates at different temperatures (from 400 to 800 degrees C), using microwave plasma enhanced chemical vapor deposition with argon-rich Ar/CH4 gas mixtures and different relative amounts of hydrogen (0-20%). Scanning electron microscopy studies showed that all the films are dense and continuous. Results of cyclic voltammetry test revealed that when there was <2% of hydrogen in the plasma, the film obtained renders the surface electrochemically inactive, with very low leakage currents ( approximately 4 x 10(-7) A/cm2 at +/-5 V). In addition, in vivo tests of the UNCD-coated Si samples were performed by implanting them in the eyes of rabbits for 4-6 months within the eye physiological environment. According to all these results, it was concluded that UNCD is a promising candidate for use as the encapsulating coatings for implantable retinal microelectronic devices.

Animals↗
PubMed2006

Characteristics of ex vivo expansion of endothelial progenitor cells.

The characteristics for the ex vivo expansion of the endothelial progenitor cells (EPCs) were explored. CD34+ cells were selected from umbilical cord blood mononuclear cells (MNC) by MiniMACS system, expanded under the same conditions as those for total MNC, coincubation of CD34+ and CD34- from the same donor for EPCs. In addition, the effects of vessel endothelial growth factor (VEGF) and passage on cell differentiation, expansion kinetics and apoptosis were examined. EPCs were determined and quantified by immunocytochemistry and flow cytometry. The results showed that both coculture of CD34+ and CD34- and total MNC led to a significant increase in the expansion of CD34+ cells as compared with CD34 enrichment (P < 0.05). There was a tendency toward decreased apoptosis in cultures when early passage was performed immediately after cord like structures appeared. VEGF had no significant effect on apoptosis (P > 0.05). These differentiated EPCs were positive for CD34+, von Willebrand factor (vWF), KDR, CD31 staining and phagocytized acetylated low-density lipoprotein (LDL). CD34+ cells accounted for (68.2 +/- 6.3)% of attaching (AT) cells at day 7 of culture. It was suggested the most efficient method to ex vivo expansion of EPCs was coculture of CD34+ and CD34- or total MNC. Early passage makes cell apoptosis rate decrease. VEGF had no significant effect on ex vivo expansion of EPCs.

Antigens, CD34↗
PubMed2006

Influence of IFN- alpha and IFN- gamma on lymphangiogenesis.

Malignant cancers commonly spread by local invasion followed by metastasis through venous or lymphatic passages or both to distant sites. Angiogenesis and its relation to tumor growth and metastasis have been extensively researched. To date, however, the role played by lymphangiogenesis and metastasis of cancer has been overlooked. Inhibition of lymphangiogenesis, compared with inhibition of angiogenesis, may provide new insight to the mechanisms of metastasis of cancers. The current study was designed to examine the effect of two commonly used inhibitors of angiogenesis, interferon-alpha (IFN-alpha ) and IFN-gamma, on the growth and proliferation of lymphatic endothelial (LE) cells isolated from pig thoracic duct under in vitro condition. The LE cells were isolated and marked using specific markers, such as VEGFR-3 and LYVE-1, before experimental studies. The results showed that treatment of LE cells derived from the thoracic duct with these two inhibitors caused a decrease in the rate of cell proliferation in a dose-dependent manner, as assessed by MTT assays (tetrazolium salt colorimetric assay). Cell migration rate was assessed by the speed at which the cell migrated out from the scrape-wound margin; the speed of migration of LE cells was significantly inhibited in a dose-dependent fashion compared with controls. Treatment with both IFN-alpha and IFN-gamma caused an increase in apoptosis of LE cells, as assessed by Hoechst staining and caspase-3 staining. Our results showed that both IFN-alpha and IFN-gamma were able to inhibit LE cell growth in a dose-dependent manner and that the inhibition may be through induction of apoptosis of endothelial cells.

Angiogenesis Inhibitors↗
PubMed2006

Potent potentiating diuretic effects of prednisone in congestive heart failure.

UNLABELLED: Animal studies showed glucocorticoids could specifically dilate renal vasculature, regulate synthesis and release of atrial natriuretic peptide (ANP), upregulate ANP receptors on vascular endothelial cells, and thus have potent potentiating diuresis and natriuresis effects in animal studies; however, their diuretic efficacy in humans is yet to be known. Therefore, we designed this randomized, double- blind, placebo-controlled, clinical study to determine the diuretic efficacy of prednisone, a glucocorticoid, in patients with congestive heart failure (CHF). METHODS: Twenty clinically stable patients with CHF without overt fluid retention were randomized to a prednisone group or placebo group. Prednisone (1 mg/kg/day with a maximum dose of 60 mg/day) was added to standard care for 7 days, leaving other medications unchanged. Variables included urine volume and electrolytes, serum electrolytes, and change from baseline in serum creatinine. RESULTS: Adding prednisone resulted in striking diuresis and natriuresis with time. As compared with the placebo group, the maximum of mean daily urine volume was 810.5 mL larger than those in the placebo group (95% confidence intervals [CI] 276.25 to 1344.86, P < 0.05). The maximum mean daily sodium excretion was 123.8 mmol higher than those patients given placebo (95% CI 11.4 to 236.2, P < 0.05). The placebo-corrected effect on change from baseline in serum creatinine was -19.5 mumol/L (95% CI -7.4 to -31.6, P < 0.01), favoring prednisone. CONCLUSIONS: This pilot study showed that prednisone had potent potentiating diuretic effects in patients with heart failure and might improve renal function in the same time. Further prospective randomized clinical studies are warranted to determine the preferable dose and its efficacy in decompensated congestive heart failure.

Adult↗
PubMed2006

Evaluation of specific antibodies for early diagnosis and management of syphilis.

For many years, tests for cardiolipin antibodies Tp15, Tp17, Tp45, Tp47, and other specific Treponema pallidum antibodies, have been used to diagnose syphilis, but the timing and rates of antibody detection differ in primary and secondary syphilis. Our objective was to determine the value of the rapid plasma reagin (RPR) test, T. pallidum passive particle agglutination (TPPA) assay and Western blotting (WB) in the diagnosis of early syphilis, by studying 67 patients (20 with primary and 47 with secondary syphilis) over a recent 5-year period. All patients were tested before and 21/67 were tested after treatment. Western blotting showed that while there was a difference within the study group in terms of the number of bands detected, all patients with primary syphilis demonstrated the 47-kDa antibody, but RPR and TPPA were negative in some patients. Eighteen to 24 months after treatment, 21/67 patients were tested by WB and TPPA; antibodies to T. pallidum became undetectable within 24 months after treatment in 29% of patients. By RPR, 29% patients had negative titers within 6 months of treatment, and 86% returned to normal within 24 months. We conclude that detection of specific 47-kDa T. pallidum antibodies can be used to diagnose primary syphilis. By RPR, antibodies disappear in 6-24 months after treatment in many patients, suggesting that a change in titer may be an indicator of treatment success.

Adult↗
PubMed2006

Protective effects of breviscapine on ischemic vascular dementia in rats.

Breviscapine, a traditional Chinese medicine, is extensively used in clinic to treat cardiovascular diseases and cerebrovascular injury. In this study, we demonstrated the effects of breviscapine on vascular dementia (VD) rats, which were mimicked by permanent occlusion of bilateral common carotid arteries. Breviscapine (2 mg/kg for 14 d) improved the performance of learning and memory of VD rats in Morris water maze, decreased the level of lipid peroxidation and free radicals, and attenuated the pathological alterations, such as nuclear shrink, cellular edema and irregular arrangement of pyramidal layer in the hippocampal CA(1) area. In vitro experiment, breviscapine (50 microg/l) protected cortical neuron from injury and decreased intracellular calcium overloading induced by H2O2 (10 mM). The results suggest that breviscapine has therapeutic effect on cerebral ischemia and vascular dementia.

Animals↗
PubMed2006

Interaction mechanism between Cd2+ ions and DNA from the kidney of the silver crucian carp.

Cadmium is one of the most toxic heavy metals and is known to accumulate in freshwater food chains. The underlying mechanism for its genotoxicity has not been investigated for any freshwater fish. It has, however, been suggested that cadmium-induced carcinogenesis might involve either direct or indirect interaction of Cd2+ with DNA. The interaction between Cd2+ and DNA from the kidney of the silver crucian carp (Carassius auratus gibelio) in vitro and in vivo is investigated by spectrophotometric methods and agarose gel electrophoresis methods. Cd2+ could insert into DNA basepairs, bind to nucleic acid, and result in notable hypochromicities. The analysis of agarose gel electrophoresis proves that Cd2+ at different concentrations does not cause DNA cleavage in vitro; however, kidneys display the classical laddering degradation of DNA in vivo, which is the result of the promotion of deoxyribonuclease activity or inhibition of superoxide dismutase and catalyse activity and the accumulation of reactive oxygen species caused by Cd2+ ions in vivo.

Animals↗
PubMed2006

Influences of nano-anatase TiO2 on the nitrogen metabolism of growing spinach.

Previous research showed that nano-TiO2 could significantly promote photosynthesis and greatly improve growth of spinach, but we also speculated that an increase of spinach growth by nano-TiO2 treatment might be closely related to the change of nitrogen metabolism. The effects of nanoanatase TiO2 on the nitrogen metabolism of growing spinach were studied by treating them with nano-anatase TiO2. The results showed that nano-anatase TiO2 treatment could obviously increase the activities of nitrate reductase, glutamate dehydrogenase, glutamine synthase, and glutamic-pyruvic transaminase during the growing stage. Nano-anatase TiO2 treatment could also promote spinach to absorb nitrate, accelerate inorganic nitrogen (such as NO3--N and NH4+-N) to be translated into organic nitrogen (such as protein and chlorophyll), and enhance the fresh weight and dry weights.

Chlorophyll↗
PubMed2006

Mechanism of nano-anatase TiO2 on promoting photosynthetic carbon reaction of spinach: inducing complex of rubisco-rubisco activase.

Having a photocatalyzed characteristic, our previous research had proved that nano-anatase TiO2 is closely related to the photosynthesis of spinach. It could not only improve the light absorbance and the transformation from light energy to electron energy and to active chemical energy but also promote carbon dioxide (CO2) assimilation of spinach. However, the mechanism of carbon reaction promoted by nano-anatase TiO2 remains largely unclear. By electrophoresis and Western blot methods, the results of the experiments proved that Rubisco from the nano-anatase TiO2-treated spinach during the extraction procedure of Rubisco was found to consist of Rubisco and a heavier molecular-mass protein (about 1,200 kDa) comprising both Rubisco and Rubisco activase. The Rubisco carboxylase activity was 2.67 times that of Rubisco from the control and it could hydrolyze ATP in the same manner as Rubisco activase. The total sulfhydryl groups and available sulfhydryl groups of the Rubisco were 32 -SH and 21 -SH per mole of enzyme more than those of the Rubisco purified from the control, respectively. The circular dichroism spectra showed that the secondary structure of Rubisco from the nano-anatase TiO2-treated spinach was very different from Rubisco of the control. It suggested that the mechanism of nano-anatase TiO2 activating Rubisco of spinach was that the complex of Rubsico and Rubisco activase was induced in spinach, which promoted Rubsico carboxylation and increased the rate of photosynthetic carbon reaction.

Carbon Dioxide↗