Search PubMed⌕ Search

Biomedical subjects

Chao Liu

Publications and source records attributed to Chao Liu.

At least 73 records · Page 4Linked to original sources
PubMed2005

[Heat-shock protein 70 may be a putative endogenous ligand of Toll-like receptor-4 of human monocytes].

OBJECTIVE: To explore the relation between human heat shock protein 70 (HSP70) and Toll-like receptor-4 (TLR4) in human monocytes. METHODS: Periphery blood mononuclear cells were isolated from the samples of healthy blood donors' whole blood and monocytes were prepared and cultured. HSP70 of the final concentrations of 2.5 microg/ml, 5.0 microg/ml, 7.5 microg/ml, and 10 microg/ml respectively was added; 6 hours later the concentration of TNF-alpha in the supernatant was detected. Another monocytes were cultured and HSP70 of the final concentration of 5.0 microg/ml was added and the concentrations of NF-kappaB were detected 0, 30, 60, and 120 minutes later respectively. TLR4 blocker of the final concentrations of 5 microg/ml, 20 microg/ml, and 30 microg/ml respectively was added into another culture for 30 minutes and 5.0 microg/ml HSP70 was added, then immunochemistry was used to detect the concentration of NF-kappaB 120 minutes after ELISA was used to detect the concentration of and TNF-alpha 8 hours later. In order to examine the influence of HSP70 on the TLR4 in the cytomembrane of monocytes, HSP70 of the final concentration of 5.0 microg/ml was added into the culture of monocytes for 0, 30, 60, and 120 minutes respectively then flow cytometry was used to detect the mean fluorescence intensity (MFI) of TLR4. RESULTS: HSP70 stimulation increased the TNF-a concentration in the supernatant dose-dependently. The percentages of NF-kappaB positive monocytes were 38 +/- 6, 67 +/- 12, and 54 +/- 12 30 min, 60 min, 120 min after HSP70 stimulation, all significantly higher than that at the beginning of experiment (17 +/- 6, P < 0.05, P < 0.01, and P < 0.01). The percentages of NF-kappaB positive monocytes were 39% +/- 4%, 32% +/- 6%, and 28% +/- 6% 120 minutes after anti-TLR4 mAb stimulation, all significantly lower than that of the control group (67% +/- 12%, all P < 0.05). TLR4 blocker of different concentrations significantly inhibited the TNF-alpha secretion by the monocytes (all P < 0.05). The MFI of TLR4 in the cytomembrane of monocyte was significantly down-regulated 60 minutes, especially 120 minutes, after the HSP70 stimulation in comparison with that before the stimulation (P < 0.05 and P < 0.01). CONCLUSION: TLR4 appears to be involved in HSP70-mediated activation of innate immunity.

Cells, Cultured↗
PubMed2005

Detection of circulating autoantibodies directed against the asialoglycoprotein receptor using recombinant receptor subunit H1.

BACKGROUND/AIMS: The asialoglycoprotein-receptor (ASGPR) is a major liver-specific target autoantigen in autoimmune hepatitis. ASGPR heteromers of two subunits H1 and H2 provide clearance of circulating asialoglycoproteins by receptor-mediated endocytosis. The aim of this study was to establish whether a recombinantly expressed subunit H1 presenting conformational epitopes is capable of detecting autoantibodies against ASGPR in patients with inflammatory liver disease. METHODS: The major subunit H1 was expressed in human-embryo-kidney 293-cells and prepared by ligand-affinity-chromatography similar to the complete receptor from normal liver. Reactivities of anti-ASGPR positive sera from 219 patients with both recombinant H1 and natural receptor were compared using enzyme-immunoassay (EIA). RESULTS: 194 of 219 sera (88.6%) showed absorbance values on 293-H1 within a range of +/-15% compared to the natural receptor. 145 of 149 sera (97.3%) positive on ASGPR were also positive on recombinant H1. Titers of 61/62 sera (98.4%) revealed no deviation of more than one dilution step. ASGPR reactivity could be inhibited in 29 sera with up to 50 ng/microl of 293-H1. CONCLUSIONS: These results indicate that the antigenic sites of the human ASGPR are mainly located on the mammalian-expressed subunit H1. Therefore, 293-H1 is a powerful tool for the detection of autoantibodies against ASGPR.

Antigens↗
PubMed2005

Hepatic venous outflow reconstruction in right live donor liver transplantation.

The increasing experience with live donor liver transplantation has allowed for the identification of potential morbidities associated with technical considerations. Technical graft failure can be associated with both inflow and outflow vascular compromise. Although the latter has not always been given the relevance of the former, evidence pointing to its pivotal role continues to mount. We believe that impaired venous outflow was a cause of previously unexplained graft failures during our initial experience. Based on this observation, we developed a technique to prevent the "choking" of the graft at the outflow anastomosis with the inferior vena cava (IVC). The enhanced outflow via a cloaca maximum is achieved by reconstructing the graft vessels with preserved veins or arteries (usually iliac vessels are used) from a blood-group-identical or blood-group-compatible deceased organ donor. Alternatively, hepatic vein or portal vein obtained from the resected native liver can be used. The reconstructed common outflow is anastomosed to a triangular opening of the IVC. Such enhanced outflow provides optimal venous drainage, especially during the early phase of growth of the graft.

Anastomosis, Surgical↗
PubMed2005

Preoperative donor liver biopsy for adult living donor liver transplantation: risks and benefits.

The role of liver biopsy (LB) in donor selection for adult living donor liver transplantation remains controversial, since the procedure is associated with additional potential risks for the donor. From April 1998 to August 2004, 730 potential living donors for 337 adult recipients underwent our multistep evaluation program. In 144 candidates, LB was performed. LB was obtained in a percutaneous ultrasound-guided fashion by means of Menghini needle (32 cases) or Tru-cut needle (112 cases). The biopsy specimen was preserved in 5% formalin and processed with hematoxylin & eosin-stained sections. Thirty-one (21%) of 144 candidates who underwent an LB had a positive finding at histological examination that induced their exclusion from donation, of whom 21 had liver steatosis of varying kind and grade (10%-80%) and 10 had a nonsteatotic hepatopathy (non-A-D hepatitis in 6 cases, diffuse granulomatosis in 2, schistosomiasis in 1, fibrosis in 1). The only observed major complications related to LB were 2 intraparenchymal haematomas, both of which resolved spontaneously within a few months. In conclusion, based on these findings, we believe that preoperative LB in the donor selection for adult LDLT is necessary, once the initial donor screening and noninvasive evaluation is complete. Because other screening modalities can be unreliable, without preoperative LB a fraction of potential donors will be operated on inappropriately, risking both donor and recipient. The main objective of LB should be to ensure the donor's safety more than the preservation of the graft function.

Adult↗
PubMed2005

Implantation of endothelial progenitor cells into laser-induced channels in rat ischemia hindlimb augments neovascularization.

The aim of this study was to investigate the effect of transmuscle laser revascularization (TMR) in combination with endothelial progenitor cell grafting on neovascularization of ischemic hindlimbs of nude rats. Mononuclear cells (MNCs) isolated from human umbilical cord blood (HUCB) by density gradient centrifugation were expanded in vitro. Spindle-shaped attaching (AT) cells and cord-like structures were developed from culture of MNCs. Acetylated low-density lipoprotein (Ac-LDL) incorporation by AT cells was performed. Phenotypic characterization was assessed by immunocytochemistry, and flow cytometry analysis. EPCs were labeled with 1, 1'-dioctadecyl-1 to 3,3, 3', 3'- tetramethyl-indocarbocyanine perchlorate (DiI) before being injected into the Nd:YAG laser channels or ischemic region. An acute ischemic limb model was created with the following four groups of nude rats by ligating the right external iliac artery: TMR + EPC group: rats with local transplantation of EPCs into laser channels; TMR group: those with transmuscular channels created without EPCs; EPC group: those with EPCs injected into the ischemic hindlimb; control group: an ischemic model without TMR or EPCs. All rats underwent femoral artery ultrasonic blood flow measurements of the ischemic and nonischemic limbs to obtain a flow ratio (femoral artery flow index [FAFI]: right femoral artery flow/left femoral artery flow) immediately after ligation of the artery (at baseline) and 28 days postoperation, and the ischemic limb muscle was sampled for histochemical and immunohistologic analysis. AT cells expressed AC 133 and endothelial cell (ECs) markers (KDR, CD34, CD31, and von Willebrand factor) and exhibited function similar to that of ECs as estimated by Ac-LDL incorporation. Flow cytometric analysis revealed that AT cells were positive for CD34 (62% +/- 7%) and AC133 (57.2% +/- 9.8%) at day 7 of culture. Twenty-eight days after the operation, the FAFI was significantly higher in the TMR+EPC group and EPC group than that in the control group. It was significantly higher in the TMR+EPC group, EPC group, and TMR group than that at their respective baselines. The FAFI in the control group was unchanged and no difference in FAFI was found between the TMR group and control group, and among the TMR+EPC, TMR, and EPC groups. TMR+EPC, TMR, and EPC treatment resulted in an increased number of capillaries in the treated regional area compared to the control group. Nd: YAG-laser transmuscle revascularization combined with the EPC grafting can significantly ameliorate perfusion and augment neovascularization in this ischemic hindlimb model of nude rats.

Animals↗
PubMed2005

Study on the resistance of severe acute respiratory syndrome-associated coronavirus.

In this study, the persistence of severe acute respiratory syndrome-associated coronavirus (SARS-CoV) was observed in feces, urine and water. In addition, the inactivation of SARS-CoV in wastewater with sodium hypochlorite and chlorine dioxide was also studied. In vitro experiments demonstrated that the virus could only persist for 2 days in hospital wastewater, domestic sewage and dechlorinated tap water, while 3 days in feces, 14 days in PBS and 17 days in urine at 20 degrees C. However, at 4 degrees C, the SARS-CoV could persist for 14 days in wastewater and at least 17 days in feces or urine. SARS-CoV is more susceptible to disinfectants than Escherichia coli and f2 phage. Free chlorine was found to inactivate SARS-CoV better than chlorine dioxide. Free residue chlorine over 0.5 mg/L for chlorine or 2.19 mg/L for chlorine dioxide in wastewater ensures complete inactivation of SARS-CoV while it does not inactivate completely E. coli and f2 phage.

Chlorine↗
PubMed2005

Concentration and detection of SARS coronavirus in sewage from Xiao Tang Shan Hospital and the 309th Hospital.

The transmission of severe acute respiratory syndrome-associated coronavirus (SARS-CoV) is associated with close contact to SARS patients and droplet secretions of those patients. The finding of positive RT-PCR results from stools of SARS patients suggests that stools of SARS patients or sewage containing stools of patients could transmit SARS-CoV. We used a novel style of electropositive filter media particle to concentrate the SARS-CoV from the sewage of two hospitals receiving SARS patients in Beijing. We also used cell culture, RT-PCR and gene sequencing to detect and identify the viruses from sewage. No infectious SARS-CoV contamination was found in any of the samples collected, but the nucleic acid of SARS-CoV could be detected in the sewage from the two hospitals before disinfection. While the RNA was only detected in three samples from the 309th Hospital, the others were negative after disinfection. These findings provide strong evidence that SARS-CoV can be excreted through the stool/urine of patients into sewage system, thus making the sewage system a possible route of transmission.

China↗
PubMed2005

Making a tooth: growth factors, transcription factors, and stem cells.

Mammalian tooth development is largely dependent on sequential and reciprocal epithelial-mesenchymal interactions. These processes involve a series of inductive and permissive interactions that result in the determination, differentiation, and organization of odontogenic tissues. Multiple signaling molecules, including BMPs, FGFs, Shh, and Wnt proteins, have been implicated in mediating these tissue interactions. Transcription factors participate in epithelial-mesenchymal interactions via linking the signaling loops between tissue layers by responding to inductive signals and regulating the expression of other signaling molecules. Adult stem cells are highly plastic and multipotent. These cells including dental pulp stem cells and bone marrow stromal cells could be reprogrammed into odontogenic fate and participated in tooth formation. Recent progress in the studies of molecular basis of tooth development, adult stem cell biology, and regeneration will provide fundamental knowledge for the realization of human tooth regeneration in the near future.

Animals↗
PubMed2005

Epidemiologic study of the predisposing factors in erythema toxicum neonatorum.

BACKGROUND: Erythema toxicum neonatorum (ETN) is a very common disease, but its predisposing factors are still unknown. OBJECTIVE: To determine the predisposing factors of ETN. METHODS: Seven hundred and eighty-three neonates born in the same hospital during the same period were investigated, and the factors predisposing to ETN were evaluated in a case-control study. RESULTS: (1) The incidence of ETN is about 43.68%, and it is significantly higher in males than in females (p < 0.001). (2) Term birth (p < 0.05), first-pregnancy birth (p < 0.001), the birth season (summer and autumn, p < 0.005), being fed with milk powder substitute or a mixed diet (p < 0.001) and vaginal delivery (p < 0.001) are the predisposing factors of ETN. (3) The severity of ETN in neonates born by vaginal delivery is significantly correlated with the total length of labor (p < 0.001). CONCLUSION: Our findings suggest that environmental factors play an important role in the onset of ETN.

Case-Control Studies↗
PubMed2005

Effect of nano-TiO(2) on strength of naturally aged seeds and growth of spinach.

The effects of nano-TiO(2) (rutile) and non-nano-TiO(2) on the germination and growth of naturally aged spinach seeds were studied by measuring the germination rate and the germination and vigor indexes of aged spinach seeds. An increase of these factors was observed at 0.25-4% nano-TiO(2) treatment. During the growth stage, the plant dry weight was increased, as was the chlorophyll formation, the ribulosebisphosphate carboxylase/oxygenase activity, and the photosynthetic rate. The best results were found at 2.5% nano-TiO(2). The effects of non-nano-TiO(2) are not significant. It is shown that the physiological effects are related to the nanometer-size particles, but the mechanism by which nano-TiO(2) improves the growth of spinach seeds still needs further study.

Chlorophyll↗
PubMed2005

Influences of nano-TiO2 on the chloroplast aging of spinach under light.

The effects of nano-TiO2 (rutile) on the chloroplast aging of spinach under light were studied. The results showed that when the chloroplasts were illuminated for 1, 5, and 10 min with 500 micromol/cm2/min light intensity, respectively, the evolution oxygen rate was rapidly increased; when the chloroplasts were treated for 20, 30, and 40 min with 500 micromol/cm2/min light intensity, respectively, the evolution oxygen rate was gradually decreased. While spinach was treated with 0.25% nano-TiO2, the rate of evolution oxygen of chloroplasts in different illumination times (1, 5, 10, 20, 30, and 40 min) was higher than that of control, and when the illumination time was over 10 min, the reduction of the evolution oxygen rate was lower than that of control. It suggested that nano-TiO2 treatment could protect chloroplasts from aging for long-time illumination. The mechanism researches indicated that nano-TiO2 treatment could significantly increase the activities of superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD), decrease accumulation of reactive oxygen free radicals and the level of malondialdehyde (MDA), and maintain stability of membrane structure of chloroplast under light.

Catalase↗
PubMed2005

Effect of nano-TiO2 on photochemical reaction of chloroplasts of spinach.

The effects of nano-TiO2 (rutile) on the photochemical reaction of chloroplasts of spinach were studied. The results showed that when spinach was treated with 0.25% nano-TiO2, the Hill reaction, such as the reduction rate of FeCy, and the rate of evolution oxygen of chloroplasts was accelerated and noncyclic photophosphorylation (nc-PSP) activity of chloroplasts was higher than cyclic photophosphorylation (c-PSP) activity, the chloroplast coupling was improved and activities of Mg2+-ATPase and chloroplast coupling factor I (CF1)-ATPase on the thylakoid membranes were obviously activated. It suggested that photosynthesis promoted by nano-TiO2 might be related to activation of photochemical reaction of chloroplasts of spinach.

Biochemistry↗
PubMed2005

Prevention by Ce3+ of DNA destruction caused by Hg2+ in fish intestine.

The interactions between Hg2+, Ce3+, and the mixture of Ce3+ and Hg2+, and DNA from fish intestine in vitro were investigated by using absorption spectrum and fluorescence emission spectrum. The ultraviolet absorption spectra indicated that the addition of Hg2+, Ce3+, and the mixture of Ce3+ and Hg2+ to DNA generated an obviously hypochromic effect. Meanwhile, the peak of DNA at 205.2 nm blue-shifted and at 258.2 nm red-shifted. The size of the hypochromic effect and the peak shift of DNA by metal ion treatments was Hg2+>Hg2++Ce3+>Ce3+. The fluorescence emission spectra showed that with the addition of Hg2+, Ce3+, and the mixture of Ce3+ and Hg2+ the emission peak at about 416.2 nm of DNA did not obviously change, but the intensity reduced gradually and the sequence was Hg2+>Hg2++ Ce3+>Ce3+. Hg2+, Ce3+, and the mixture of Ce3+ and Hg2+ had 1.12, 0.19, and 0.41 binding sites to DNA, respectively; the fluorescence quenching of DNA caused by the metal ions all attributed to static quenching. The binding constants (KA) of binding sites were 8.98 x 104 L/mol and 1.02 x 104 L/mol, 5.12 x 104 L/mol and 1.10 x 103 L/mol, 6.66 x 104 L/mol and 2.36 x 103 L/mol, respectively. The results showed that Ce3+ could relieve the destruction of Hg2+ on the DNA structure.

Animals↗
PubMed2005

Immunosuppressive treatment for inflammatory cardiomyopathy: meta-analysis of randomized controlled trials.

The use of immunosuppressive therapy for inflammatory cardiomyopathy is controversial. The aim of this review is to summarize the current empirical evidence for immunosuppressive treatment in inflammatory cardiomyopathy. We conducted a meta-analysis of all randomized controlled trials (RCTs) that compared immunosuppressive therapy with either placebo or conventional treatment in patients with inflammatory cardiomyopathy. The pooled outcomes were all-cause death and heart transplantation for inflammatory cardiomyopathy, left ventricular ejection fraction (LVEF), and left ventricular end diastolic dimension (LVEDD). Five trials involving 316 patients were included. Overall, immunosuppressive therapy was not superior to placebo and conventional therapy in the pooled outcome of all-cause death and heart transplantation (odds ratio [OR] 1.03, 95% confidence intervals [CI] 0.58 to 1.80) in the long-term. The pooled data showed that there might be a short-term beneficial effect on LVEF improvement (5.06%, 95% CI -0.07% to 10.18%) in patients receiving immunosuppressive therapy, but no beneficial effect on LVEDD either in the short-term (-0.87 mm; 95% CI, -8.29 to 6.55 in adult patients) or long-term (-0.52 mm, 95% CI -3.64 to 2.60 in adult patients) was observed. There is no evidence to suggest that immunosuppressive therapy has an effect on improving the survival of patients with inflammatory cardiomyopathy. Current therapy in inflammatory cardiomyopathy seems to be limited to supportive measures or transplantation.

Adult↗
PubMed2005

[Treatment of primary trigeminal neuralgia with radiofrequency thermogangliocoagulation: Report of 152 consecutive cases].

PURPOSE: To evaluate the clinical results of primary trigeminal neuralgia treated by RFT and investigate the methods to manage complications. METHODS: 152 cases of primary trigeminal neuralgia were collected from 2001 to 2004, a retrospective study was undertaken to analyze the clinical characters such as effective rate, ineffective rate and the rate of complications of patients treated with RFT. RESULTS: The average age of the 152 cases was 48.9 years old, the rate of male to female was 1:1.3. The effective rate of primary trigeminal neuralgia treated with RFT was 94.1%, the ineffective rate was 2.6%;another 3.3% cases gave up or altered to other methods, the rate of complications was 15.8%. CONCLUSIONS: RFT is an effective method to treat primary trigeminal neuralgia with few severe complications and low mortality rate, which can save the sense of touch partly. Recurrent cases can be retreated with RFT.

Electrocoagulation↗
PubMed2005

[The expression of survivin messenger RNA in sputum and cancerous tissue in human lung cancer].

OBJECTIVE: To study the diagnostic significance of the expression of survivin mRNA in transbronchial biopy samples and sputum samples in lung cancer. METHODS: The resected lung cancer tissues and their para-carcinomatous normal tissue specimens of 41 patients with lung cancer and tissue specimens of 9 patients with benign pulmonary diseases were studied. 110 bronchial biopsy specimens from 80 patients with lung cancer and 30 patients with benign pulmonary diseases and their 160 sputum samples were also evaluated. RT-PCR was performed for the detection of survivin mRNA expression in specimens. The results were compared with their histological or cytological examinations. RESULTS: (1) The positive rate of survivin mRNA in resected lung cancer tissues (29/41; 70.7%) was higher than that in the para-carcinomatous normal tissues (7/41; 17.1%) and the benign pulmonary tissues (1/9; 11.1%, P < 0.05). There was no statistical difference (P > 0.05) in the positive rate of survivin mRNA between para-carcinomatous normal tissues and the benign pulmonary disease tissues. In the bronchial biopsy samples, the positive rate of survivin mRNA in 80 lung cancer tissues (51/80; 63.8%) was also higher than that in the benign pulmonary tissues (4/30; 13.3%, P < 0.05). There were no relationships between survivin mRNA expression and age, sex, histopathological subtype, differentiation, or lymph node metastases of the patients. The sensitivity and specificity of diagnosis for lung cancer by detecting survivin mRNA in resected cancer tissue and transbronchial biopsy tissue were 63.8% - 70.7% and 86.7% - 88.9%, respectively. (2) The sensitivity of cytological examinations combined with detecting survivin mRNA in sputum samples was higher than that of either cytological examination or survivin mRNA detection of sputum samples alone (P < 0.05). The sensitivity of the diagnosis for lung cancer increased from 47.1% (sputum cytology alone) to 80.2% (sputum survivin mRNA detection combined with sputum cytology, P < 0.05) and the negative predictive value increased from 37.9% for sputum cytology alone to 57.9% (P < 0.01) for sputum survivin mRNA detection combined with sputum cytology. The specificity did not change significantly. CONCLUSIONS: Detecting survivin mRNA expression from bronchial biopsy specimens might be used as one of the specific molecular markers for diagnosis of lung cancer, while the detection of survivin mRNA from sputum samples as a new ancillary diagnostic method for lung cancer.

Adult↗
PubMed2005

[Effect of Pb2+ on spectral characteristics of DNA from fish intestines].

The interaction of Pb2+ and DNA of fish intestines was investigated using absorption spectrum, fluorescence emission spectrum, and electrophoresis. Ultraviolet absorption spectra indicated that with the addition of Pb2+, the DNA generated obvious hypochromic effect, and the absorption peak at 207 nm of DNA was blue-shifted. The fluorescence emission spectra showed that with the addition of Pb2+ , the emission peak of DNA at about 419 nm did not have obvious changes, but the intensity of fluorescence reduced gradually, showing that Pb2+ has quenching effect on the DNA endogenous fluorescence. Pb2+ has 0.8 binding sites to DNA, and the fluorescence quenching of DNA caused by Pb2+ belongs to static quenching. The binding constants of binding sites are 6.08 x 10(4) L x mol(-1) and 2.82 x 10(4) L x mol(-1) from the Lineweaver-Burk plot. The experiments of ultraviolet and fluorescence spectra showed that exogenous Pb2+ could cause some changes to the conformation of DNA, but analysis of electrophoresis proved that exogenous Pb2+ at different concentration did not result in DNA breakage.

Algorithms↗