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Biomedical subjects

Jian Liu

Publications and source records attributed to Jian Liu.

At least 55 records · Page 3Linked to original sources
PubMed2006

Identification of 2-acylaminothiophene-3-carboxamides as potent inhibitors of FLT3.

A series of 2-acylaminothiophene-3-carboxamides has been identified which exhibit potent inhibitory activity against the FLT3 tyrosine kinase. Compound 44 inhibits the isolated enzyme (IC50 = 0.027 microM) and blocks the proliferation of MV4-11 cells (IC50 = 0.41 microM). Structure-activity relationship studies within this series are described in the context of a proposed binding model within the ATP binding site of the enzyme.

Amides↗
PubMed2006

Thrombin/thrombin receptor (PAR-1)-mediated induction of IL-8 and VEGF expression in prostate cancer cells.

Interleukin 8 (IL-8) and vascular endothelial growth factor (VEGF) are two cytokines promoting prostate tumor growth and angiogenesis. The main coagulation protease thrombin may modulate the malignant phenotype of prostate cancer cells via its cellular receptor(s). We aimed to investigate the effects of thrombin on IL-8 and VEGF expression in DU 145 prostate cancer cells. Thrombin induced the expression and secretion of IL-8 and VEGF, with more pronounced effects on IL-8. Target-specific siRNA-induced protease-activated receptor 1 (PAR-1) knockdown completely neutralized thrombin-enhanced cytokine secretion, demonstrating the essential role of PAR-1. Inhibitors of either extracellular signal-regulating kinase (ERK) or phosphatidylinositol 3-kinase (PI3K) partly reversed the thrombin-induced cytokine expression, suggesting that both ERK and PI3K kinase pathways may be involved in IL-8 and VEGF expression. The results suggest that the thrombin/PAR-1 system upregulates cytokines in prostate cancer cells which in turn may contribute to the progression of prostate cancer.

Extracellular Signal-Regulated MAP Kinases↗
PubMed2006

Plastic microchip liquid chromatography-matrix-assisted laser desorption/ionization mass spectrometry using monolithic columns.

A prototype array of monolithic liquid chromatography (LC) columns was prepared in a plastic microfluidic device for the off-line interface with matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). The microfluidic channels were fabricated on a cyclic olefin copolymer (COC) plate by hot embossing. An array of methacrylate monolithic columns was prepared in the microfluidic channels by UV-initiated polymerization. The deposition system employed a pulsed electric field to transfer the effluents from multiple columns directly onto MALDI targets with a non-contact deposition method reported by Ericson et al. [C. Ericson, Q.T. Phung, D.M. Horn, E.C. Peters, J.R. Fitchett, S.B. Ficarro, A.R. Salmon, L.M. Brill, A. Brock, Anal. Chem. 75 (2003) 2309]. To characterize the off-line interface of the multiple-channel microchip LC and the MALDI-MS for the analysis of peptide mixtures, the separation efficiency and reproducibility tests in each column were carried out by separating a peptide mixture from tryptic digested proteins and depositing the multiple effluents simultaneously on the MALDI target plate. Using a MALDI-TOF mass spectrometer with a mass accuracy of +/-1 Da for peptide assignments of digested bovine serum albumin (BSA), amino acid sequence coverage of around 59% was obtained for the microchip LC-MALDI-MS compared to 23% obtained by the MALDI-MS method without LC separation. In sensitivity tests for the detection of low abundance proteins in the presence of high concentration protein mixtures, as low as 10 fmol/mul (S/N = 10) of a spiked peptide in 1 microg of digested BSA could be detected. In the analysis of a mixture of three digested proteins (BSA, myoglobin, and cytochrome c), more than twice the amino acid sequence coverage was obtained for the microchip LC-MALDI-MS compared to MALDI-MS alone.

Cytochromes c↗
PubMed2006

[CT guided radioactive seed 125I implantation in treatment of pancreatic cancer].

OBJECTIVE: To investigate the clinical value of CT guided radioactive seed (125)I implantation in treatment of pancreatic cancer. METHODS: Twenty-six patients with pancreatic cancer 6.1 cm in size on average, 21 males and 5 females, aged 60 +/- 13 (47 - 73), underwent CT guided radioactive seed (125)I implantation. Of the 26 patients 15 had the symptom of severer abdominal pain and 10 had jaundice. Three of them were in the TNM (pTNM) stage II, 30 in the stage III, and 3 in the stage IV. Treatment plan system was used to design the distribution of the seed (125)I needed. Under CT guidance, the (125)I seeds of (2.2 - 3.3) Mq were implanted into the pancreatic cancer at a distance of 1.0 - 1.5 cm. A follow-up for 3 - 12 months was conducted. RESULTS: Complete relief (CR) of the symptoms was seen in 9 patients, partial relief (PR) in 2 patients, and no change (NC) in 4 cases with an effective rate of 73.4%. The abdominal pain was relieved 3 - 7 days after the implantation. CT performed 2 months after implantation showed CR in 2 cases, PR in 13 cases, NC in 5 cases, and progression in 5 cases with an overall effective rate of 57.7%. Four patients died of local progression and 2 patients died of distant metastasis. Migration of the seeds into the liver was seen in 3 patients and slight decrease of white blood cells was seen in 1 patient during the 2-month follow-up. No severe complications, such as pancreatic leakage, acute pancreatitis, intestinal hemorrhage, etc, were found. CONCLUSION: Safe and with minimal damage and few complications, CT guided radioactive seed (125)I implantation is effective in treatment of pancreatic cancer.

Aged↗
PubMed2006

Telomerase activity in peripheral blood mononuclear cells from senile patients with pneumonia.

To investigate the changes of the activity of telomerase in peripheral blood mononuclear cells (PBMCs) from senile patients with pneumonia, the telomerase activity was examined before and after the stimulation of phytohemagglutinin-M (PHA-M) in PBMCs from 10 control subjects (group A), 12 non-senile patients with pneumonia (group B) and 9 senile patients with pneumonia (group C). Also observed was the proliferative response of these PBMCs to PHA-M. The results showed that, both with or without the stimulation of PHA-M, the values of telomerase activity in PBMCs from group C patients (A values: pre-stimulation, 0.43 +/- 0.04; post-stimulation, 0.63 +/- 0. 03) were significantly lower than those in PBMCs from both group A patients (A values: pre-stimulation, 0.65 +/- 0.05; post-stimulation, 1.26 +/- 0.13; P<0.001, respectively) and group B patients (A values: pre-stimulation, 0.63 +/- 0.03; post-stimulation, 0.93 +/- 0.03; P<0.05, respectively). The results of MTT test showed that the proliferative activity of PBMCs in group C patients (A value: 0.35 +/- 0.03) was also significantly lower than that in group A patients (A value: 0. 55 +/- 0.04; P<0.05) and group B patients (A value: 0.46 +/- 0.03; P<0.05). These results indicate that the telomerase activity decreases in senile patients with pneumonia, which may be one of the mechanisms for the weakened immune function in those patients.

Age Factors↗
PubMed2006

Discrete cues paired with naloxone-precipitated withdrawal from acute morphine dependence elicit conditioned withdrawal responses.

Acute bolus doses of morphine induce a state of acute opioid dependence as measured by naloxone-precipitated withdrawal. Repeated morphine and precipitated withdrawal experience further enhances naloxone-induced withdrawal severity, partly because of direct neuroadaptation to repeated morphine, and partly because of conditioned associations of context and withdrawal experience. To determine whether a discrete tone/light conditioned stimulus could elicit conditioned withdrawal responses in acute dependence, rats trained on a fixed-ratio-15 operant schedule for food reward received morphine (5.6 mg/kg) 4x at daily or weekly intervals, with each morphine injection followed at 4 h by naloxone (1.0 mg/kg) and an operant session. The conditioned stimulus was presented to a Paired group after each naloxone injection. Separate control groups experienced the conditioned stimulus either at a different time of the day or on a different day of the week than naloxone (Unpaired), received naloxone without any conditioned stimulus exposure [Paired-no conditioned stimulus (Paired-NO CS)] or received vehicle instead of naloxone before conditioned stimulus presentation (NaI-Naive). On the test day, all rats received vehicle before conditioned stimulus exposure. The conditioned stimulus alone reliably suppressed responding in Paired groups relative to control conditions with either daily or weekly intervals between conditioning sessions. The administration of morphine 4 h before conditioned stimulus exposure on the test day was not necessary to observe conditioned withdrawal. Thus, conditioned withdrawal is reliably established to discrete cues associated with naloxone-precipitated withdrawal from acute, infrequent (weekly) opioid exposure.

Acoustic Stimulation↗
PubMed2006

Role for 3-O-sulfated heparan sulfate as the receptor for herpes simplex virus type 1 entry into primary human corneal fibroblasts.

Herpes simplex virus type 1 (HSV-1) infection of the corneal stroma remains a major cause of blindness. Primary cultures of corneal fibroblasts (CF) were tested and found susceptible to HSV-1 entry, which was confirmed by deconvolution imaging of infected cells. Plaque assay and real-time PCR demonstrated viral replication and hence a productive infection of CF by HSV-1. A role for glycoprotein D (gD) receptors in cultured CF was determined by gD interference assay. Reverse transcription-PCR analysis indicated expression of herpesvirus entry mediator and 3-O-sulfated (3-OS) heparan sulfate (HS)-generating enzyme 3-O sulfotransferase 3 (3-OST-3) but not nectin-1 or nectin-2. Subsequently, HS isolated from these cells was found to contain two distinct disaccharides (IdoUA2S-AnMan3S and IdoUA2S-AnMan3S6S) that are representative of 3-OST-3 activity. The following lines of evidence supported the important role of 3-OS HS as the mediator of HSV-1 entry into CF. (i) Blockage of entry was observed in CF treated with heparinases. The same enzymes had significantly less effect on HeLa cells that use nectin-1 as the entry receptor. (ii) Enzymatic removal of cell surface HS also removed the major gD-binding receptor, as evident from the reduced binding of gD to cells. (iii) Spinoculation assay demonstrated that entry blockage by heparinase treatment included the membrane fusion step. (iv) HSV-1 glycoprotein-induced cell-to-cell fusion was inhibited by either prior treatment of cells with heparinases or by HS preparations enriched in 3-OS HS. Taken together, the data in this report provide novel information on the role of 3-OS HS in mediating infection of CF, a natural target cell type.

Animals↗
PubMed2006

PRIMA: peptide robust identification from MS/MS spectra.

In proteomics, tandem mass spectrometry is the key technology for peptide sequencing. However, partially due to the deficiency of peptide identification software, a large portion of the tandem mass spectra are discarded in almost all proteomics centers because they are not interpretable. The problem is more acute with the lower quality data from low end but more popular devices such as the ion trap instruments. In order to deal with the noisy and low quality data, this paper develops a systematic machine learning approach to construct a robust linear scoring function, whose coefficients are determined by a linear programming. A prototype, PRIMA, was implemented. When tested with large benchmarks of varying qualities, PRIMA consistently has higher accuracy than commonly used software MASCOT, SEQUEST and X! Tandem.

Amino Acid Sequence↗
PubMed2006

An epidemiologic study of posttraumatic stress disorder in flood victims in Hunan China.

OBJECTIVE: To estimate the occurrence and to assess the determinants of posttraumatic stress disorder (PTSD) in flood victims. METHOD: We carried out a retrospective study to examine the occurrence and the determinants of PTSD in victims of flood in 1998 and 1999 in Hunan, China. We used multistage sampling to select the subjects from the flood areas, and we ascertained PTSD according to DSM-IV criteria. Data were collected in face-to-face interviews carried out by experienced research assistants using a preconstructed questionnaire. We used a multiple logistic regression model to analyze the data. RESULTS: A total of 33 340 subjects (86.0% of the selected subjects, aged 7 years or over) in the study villages were interviewed. Among them, 2875 (8.6%) had symptoms that met the diagnostic criteria for PTSD. Significant risk factors for PTSD included female sex (odds ratio [OR] 1.12; 95% confidence interval [CI], 1.04 to 1.21), older age (age 18 to 59 years OR 2.28; 95%CI, 2.02 to 2.57, and age > or = 60 years OR 2.42; 95%CI, 2.05 to 2.85), flood type (collapsed embankment OR 1.84; 95%CI, 1.64 to 2.05, and flash flood OR 3.12; 95%CI, 2.76 to 3.52), and flood severity (intermediate OR 4.05; 95%CI, 3.55 to 4.62, and severe OR 2.98; 95%CI, 2.60 to 3.41). CONCLUSIONS: PTSD is a common mental disorder in flood victims, which implies the need for improved health services, especially mental health services, for this population.

Adolescent↗
PubMed2006

[Effects of traditional Chinese medicine for invigorating spleen to resolve dampness and dredging collaterals on patients with rheumatoid arthritis and anemia].

OBJECTIVE: To observe the clinical effects of Xinfeng Capsules (XFC), a traditional Chinese medicine for invigorating the spleen to resolve dampness and dredging collaterals, on patients with rheumatoid arthritis (RA) and anemia, and to investigate its mechanism. METHODS: Forty patients with RA and anemia were divided into three groups: XFC-treated group (n=20), Tripterygium glycosides Tablets (TGT)-treated group (n=10) and methotrexate (MTX)-treated group (n=10). The patients in each group took corresponding medicine for three months. The response rates of the three groups were evaluated after treatment. The general symptoms and specific signs and symptoms of RA were observed before and after the treatment. The indexes of blood routine examination and some other laboratory indexes such as erythrocyte sedimentation rate (ESR), and blood levels of rheumatoid factor (RF), iron, C-reaction protein (CRP), immunoglobins (Ig), complements 3 and 4, tumor necrosis factor-alpha (TNF-alpha), interleukin-10 (IL-10) and erythropoietin (EPO) were all examined and compared before and after treatment. RESULTS: The total response rate in the XFC-treated group was similar to those both in the TGT-treated and MTX-treated groups. The effects on relieving specific symptoms of RA in the three groups were also similar. The ESR and serum levels of RF, CRP, IgG, IgA and IgM were all decreased after treatment as compared with those before treatment in the three groups, and there were no significant differences among those laboratory indexes in the three groups after treatment. The XFC displayed more obvious effects on improving the general symptoms of patients with RA and anemia, increasing the blood levels of hemoglobin, iron and IL-10, while decreasing the serum level of TNF-alpha and regulating the serum EPO level, as compared with those in the TGT-treated and MTX-treated groups. CONCLUSION: The XFC for invigorating the spleen to resolve dampness and dredging collaterals was developed on the basic principle of regulating spleen. It can obviously improve the symptoms and laboratory indicators of RA. Such effects may be related to maintaining the balance of cytokines, regulating the serum level of EPO and increasing the serum iron level in patients with RA and anemia.

Anemia↗
PubMed2006

Cloning and molecular characteristic of the metalloprotease gene LeftsH6 from tomato.

The full-length 2213-bp ftsH (filamentation temperature-sensitive H) cDNA was cloned from the cDNA library of heat-shocked tomato leaves. According to an open reading frame of 2019-bp, the deduced protein precursor was predicted to target chloroplast. The putative AAA (ATPases associated with diverse cellular activities) domain and the Zn(2+)-binding domain, characteristic of FtsH metalloproteases family, were found in the FtsH-like protein. Most similar to the FtsH6 of Arabidopsis thaliana, the tomato ftsH-like gene was named as Lycopersicon esculentum filamentation temperature-sensitive H6 (LeftsH6). Purified FtsH degraded casein but not BSA in vitro, whereas a FtsH mutant with the Glu(472) in the zinc-binding motif replaced by Gln had lost the protease activity. A single copy of LeftsH6 was detected in tomato genome by Southern blot analysis. Northern and Western blot analyses revealed consistently the heat-inducible character of the LeftsH6 gene. No LeftsH6 expression was detected after cold, salt, drought or light stress. The results provided the first experimental evidence of the existence of heat-inducible ftsH gene in higher plants.

Amino Acid Sequence↗
PubMed2006

[Molecular cloning of tomato LeHsp110/ClpB gene and its effect on the thermotolerance in plant].

The heat shock protein ClpB is a member of the Clp family and functions as molecular chaperones. ClpB is related to the acquired thermotolerance in organisms. A cDNA of 3144 bp was screened out of a tomato cDNA library. The polypeptide deduced from the longest ORF contains 980 amino acid residues, and was classified into HSP100/ClpB family based on the result of molecular phylogenesis analysis. Thus it was named as LeHSP110/ClpB according to its calculated molecular weight. LeHSP110/ClpB was characteristic of heat-inducibility but no constitutive expression, and was demonstrated to locate in chloroplastic stroma. An antisense cDNA fragment of LeHsp110/ClpB under the control of CaMV 35S promoter was introduced into tomato by Agrobacterium tumefactions-mediated method. At high temperature, the mRNA levels of LeHsp110/ClpB in antisense transgenic plants were lower than those in control plants. The PS II of transgenic plants is more sensitive to high temperature than that of control plants according to data of Fv/Fm. These results clearly showed that HSP110/ClpB plays an important role in thermotolerance of high plants.

Adaptation, Physiological↗
PubMed2006

[Effects of intracoronary autologous bone marrow mononuclear cells transplantation in patients with anterior myocardial infarction].

OBJECTIVES: To investigate the efficacy of intracoronary transfer of autologous bone marrow mononuclear cells (ABMMNCs) to patients with myocardial infarction (MI) on left ventricular function and myocardial perfusion. METHODS: Thirty-five patients with MI (> 4 weeks) were enrolled in this prospective, open-labeled study (20 patients in cell transplantation group; 15 patients in control group). All patients were treated by standard drug therapy and percutaneous coronary intervention (PCI). Baseline and 3 months follow-up evaluations included complete clinical and laboratory examinations, six minutes walk test, echocardiography, Dual-isotope simultaneous acquisition single photon emission computed tomography (DISA-SPECT) and cardiac magnetic resonance imaging (MRI). RESULTS: Baseline parameters were similar between the two groups. NYHA classification and six minutes walk test at 3 months follow-up were also similar between the two groups. However, left ventricular ejection fraction (LVEF) determined by echocardiography and DISA-SPECT was significantly higher; regional wall motion measured by echocardiography and cardiac MRI, myocardial viability and myocardial perfusion in the infarct zone assessed by DISA-SPECT were all significantly improved than before transplantation and than that in control group at 3 months follow-up. CONCLUSIONS: Our results indicate that intracoronary transplantation of ABMMNCs could improve the left ventricular systolic function and beneficially affect myocardial perfusion up to 3 months post transplantation in patients with myocardial infarction.

Bone Marrow Transplantation↗
PubMed2006

[Gene transfer of CD151 enhanced myocardial angiogenesis and improved cardiac function in rats with experimental myocardial infarction].

OBJECTIVE: To investigate the effects of in vivo CD151 gene transfer on angiogenesis and heart function in rats with myocardial infarction. METHODS: Acute myocardial infarction (AMI) was induced in male Sprague-Dawley (SD) rats by left anterior descending coronary artery ligation. The surviving rats randomly received myocardial injection of saline (MI control), pAAV-CD151 and pAAV-GFP (n = 12/group). Sham-operated rats without myocardial injection (n = 12) were taken as normal control. Four weeks later, heart function and the expression of CD151 were measured. Micro vessels density (MVD) in infarct myocardium was observed by factor VIII related antigen immunochemical staining. RESULTS: The expression of CD151 (1.98 +/- 0.23 vs. 0.91 +/- 0.09, P < 0.01) and MVD counting [(385.4 +/- 79.9) vs. (252.5 +/- 43.0) n/mm(2), P < 0.01] in pAAV-CD151 treated MI rats were significantly higher than that in MI control group, similarly, EF (64.0 +/- 8.7)% vs. (41.5 +/- 5.0)%, P < 0.01] and dp/dt(max) (6620.2 +/- 884.6 vs. 5545.5 +/- 693.0, P < 0.01) were also significantly increased post pAAV-CD151 treatment. These parameters were not affected by pAAV-GFP treatment. CONCLUSION: CD151 in vivo gene transfer for rats with acute myocardial infarction enhanced myocardial angiogenesis and improved left ventricular function.

Animals↗
PubMed2006

[Inhibitory effects of matrix metalloproteinase (MMP) inhibitor LY52 on expression of MMP-2 and MMP-9 and invasive ability of human ovarian carcinoma cell line SKOV3].

BACKGROUND & OBJECTIVE: Enhanced expression and activation of matrix metalloproteinase-2 (MMP-2) and MMP-9 are associated with tumor progression, invasion, and metastasis. Using synthetic MMP inhibitors to block the proteolytic activity of these enzymes is a potential strategy of treating cancer. This study was to observe the inhibitory effects of LY52, a synthetic specific MMP inhibitor, on the expression of MMP-2 and MMP-9 and invasive ability of human ovarian carcinoma cell line SKOV3. METHODS: The inhibitory effect of LY52 on growth of SKOV3 cells was measured by MTT and clonogenic assays. The inhibitory effect of LY52 on the activity of gelatin was evaluated by spectrophotometry using succinylated gelatin as substrate. The inhibitory effect of LY52 on the expression of MMP-2 and MMP-9 was analyzed using SDS-PAGE zymography. The adhesive ability of SKOV3 cells to fibronectin (FN), laminin (LN), and matrigel was measured using MTT assay. The invasive ability of SKOV3 cells was assessed with a transwell cell culture chamber. RESULTS: LY52 had weak cytostatic effect on SKOV3 cells, the inhibitory rates were 10.54%-37.66% within 120 h incubation when the concentration was 10 microg/ml. LY52 inhibited gelatin degradation via suppressing the activities of gelatinases, the 50% inhibitory concentration (IC50) was 11.9 microg/ml. When treated with 0.1, 1, 10, 100, or 1,000 microg/ml LY52 for 24 h, the expression of MMP-2 in SKOV3 cells was suppressed by 10.66%-31.47%, and the expression of MMP-9 was suppressed by 22.56%-56.71%. When treated with LY52 for 1 h, the maximum inhibitory rates of adhesion of SKOV3 cells to FN, LN, and matrigel were 29.79%, 48.94%, and 50.92%, respectively. When treated with 0.1, 1, 10, 100, and 1,000 microg/ml LY52 for 24 h, the inhibitory rates of invasion of SKOV3 cells were 7.5%, 42.07%, 66.54%, 72.15%, and 82.84%, respectively. CONCLUSION: LY52 suppresses the invasion of SKOV3 cells via inhibiting the expression of MMP-2 and MMP-9.

Caffeic Acids↗
PubMed2006

[Overexpression of small heat-shock protein of endoplasmic reticulum enhances resistance of tomato to tunicamycin].

The accumulation of unfolded proteins in the endoplasmic reticulum (ER) lumen causes ER stress response in eukaryote cells, activates the unfolded protein response (UPR) and consequently induces the expression of ER-located molecular chaperones (such as BiP, calnexin, etc.). In this study, the full-length small heat-shock protein of endoplasmic reticulum cDNA (ER-sHSP) under the control of CaMV 35S promoter was introduced into tomato by Agrobacterium tumefactions mediated method (Fig. 1, Table 1). Overexpression of ER-sHSP enhanced the resistance of the transgenic plant to tunicamycin (Fig. 2, Table 2), an inducer of ER stress. Tunicamycin treatment induced an increase in mRNA level of BiP and calnexin in plant cell, but mRNAs of these two genes in transgenic plants were accumulated to a much smaller extent than those in non-transgenic plants (Fig. 3). These results indicated that ER-sHSP could alleviate the ER stress and may be involved in the UPR signal transmission pathway.

Blotting, Northern↗
PubMed2005

[Role of bcl-2 transcriptional regulation induced by calmodulin I pressure overload rat hypertrophic hearts].

This study was designed to evaluate the role of bcl-2 transcriptional regulation induced by calmodulin I (CaM I) in pressure overload rat hypertrophic hearts. The model of hypertensive Sprague-Dawley rat was established by abdominal aortic constriction. The hearts were collected four weeks after abdominal aortic constriction. Velocity and isopyknic gradient centrifugation was employed to fractionate rat myocardial nuclei. Western blot analysis revealed a marked increase in phosphorylated cAMP response-element binding protein (pCREB) of cardiac hypertrophy group compared with that in control group (P<0.05), while the protein level of cAMP response-element binding protein (CREB) was constant (P>0.05). Immunohistochemistry results showed a significant increase of CaM I protein in cardiac hypertrophy group relative to the control group (P<0.05). Nuclear run off transcription assay displayed a significant increase in bcl-2 mRNA treated with trifluoperazne compared with non-drug treatment (P<0.05). The results obtained suggest that the transcription of bcl-2 is possibly regulated by CaM I hypertrophic rat hearts, and CREB phosphorylation seems to be a minor factor in bcl-2 transcriptional regulation.

Animals↗