Wiring electrons of cytochrome c with silver nanoparticles in layered films.
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Animals↗
Biomedical subjects
Tao Liu
Publications and source records attributed to Tao Liu.
Macrophage inhibitory cytokine 1 reduces cell adhesion and induces apoptosis in prostate cancer cells.
Macrophage inhibitory cytokine 1 (MIC-1), a divergent member of the transforming growth factor-beta superfamily, is linked to the pathogenesis of cancer. To delineate possible roles for MIC-1 in prostate cancer, a number of prostate epithelial cell lines have been studied, including PZ-HPV-7, DU-145, PC-3, and LNCaP cells. Factors regulating the production of MIC-1 protein by these cells and some of the effects of MIC-1 on them were investigated. Although PZ-HPV-7 and DU-145 produced no MIC-1 protein, PC-3 and LNCaP cells secreted MIC-1 protein at high levels. The secretion of MIC-1 in LNCaP cells was modulated by both androgen and estrogen. Although neither MIC-1 nor anti-MIC-1 antibody had any effect on the proliferation of epithelial cells, MIC-1 induced changes in DU-145 cells. These cells became flattened and more spread out, and this was accompanied by reduced intercellular actin filaments and intercellular junctions. The DU-145 cells then detached from their substrate and underwent caspase-dependent apoptosis. To define some of the genes responsible for these changes, cDNA microarrays, followed by confirmatory reverse transcription-PCR, was used to analyze differential gene expression induced by MIC-1. The antiapoptotic gene metallothionein 1E and cell adhesion genes RhoE and catenin delta 1 were down-regulated by more than 2-fold by MIC-1, suggesting that they were, at least in part, responsible for the observed changes in the behavior of DU-145 cells. These findings suggest that although MIC-1 has no effect on cell proliferation, it reduces cell adhesion and consequently induces cell detachment. It is likely that caspase-dependent apoptosis is secondary to loss of cell adhesion and may suggest a role for MIC-1 in tumor dissemination in vivo.
Apoptosis↗
Total synthesis of anti-HIV agent chloropeptin I.
A convergent diastereo- and enantioselective total synthesis of anti-HIV agent chloropeptin I is reported. Important features of the total synthesis include: (1) the use of Ti-catalyzed cyanide addition to imines to prepare a requisite amino acid moiety, (2) the discovery of the positive effect of MeOH in the Cu-mediated biaryl ether formation to afford one of the two macrocyclic peptide moieties, and (3) the discovery of the positive influence of collidine in the diastereoselective Pd-mediated cross-coupling to result in efficient formation of another macrocycle within this medicinally important molecule. This key step is performed in the presence of four unprotected phenols, two of which reside on dichlorophenylglycines.
Anti-HIV Agents↗
Isolation and determination of p-hydroxybenzoylcholine in traditional Chinese medicine Semen sinapis Albae.
A special component is isolated from Semen sinapis Albae (white mustard seed), a traditional Chinese medicine. According to the physical and chemical investigation and spectroscopic identification, this component can be known as p-hydroxybenzoylcholine bisulfate, a choline base. This component in the drug is also determined by RP-HPLC. A reversed-phase C(18) column is used to separate the p-hydroxybenzoylcholine with an eluent of methanol-0.05 mol/L monopotassium phosphate solution (30:70) (adjusted by phosphoric acid to pH 3.6) at the flow rate of 0.5 mL/min. Detection is carried out with a UV detector operated at 285 nm, and the column temperature is 25 degrees C. It reveals that there is 0.021% (w/w) of p-hydroxybenzoylcholine bisulfate in Semen sinapis Albae and 0.037% (w/w) in stir-baked Semen sinapis Albae.
Benzoylcholine↗
MLCT state structure and dynamics of a copper(I) diimine complex characterized by pump-probe X-ray and laser spectroscopies and DFT calculations.
The molecular structure and dynamics of the photoexcited metal-to-ligand-charge-transfer (MLCT) state of [Cu(I)(dmp)(2)](+), where dmp is 2,9-dimethyl-1,10-phenanthroline, in acetonitrile have been investigated by time-domain pump-probe X-ray absorption spectroscopy, femtosecond optical transient spectroscopy, and density functional theory (DFT). The time resolution for the excited state structural determination was 100 ps, provided by single X-ray pulses from a third generation synchrotron source. The copper ion in the thermally equilibrated MLCT state has the same oxidation state as the corresponding copper(II) complex in the ground state and was found to be penta-coordinate with an average nearest neighbor Cu-N distance 0.04 A shorter than that of the ground state [Cu(I)(dmp)(2)](+). The results confirm the previously proposed "exciplex" structure of the MLCT state in Lewis basic solvents. The evolution from the photoexcited Franck-Condon MLCT state to the thermally equilibrated MLCT state was followed by femtosecond optical transient spectroscopy, revealing three time constants of 500-700 fs, 10-20 ps, and 1.6-1.7 ns, likely related to the kinetics for the formation of the triplet MLCT state, structural relaxation, and the MLCT excited-state decay to the ground state, respectively. DFT calculations are used to interpret the spectral shift on structural relaxation and to predict the geometries of the ground state, the tetracoordinate excited state, and the exciplex. The DFT calculations also indicate that the amount of charge transferred from copper to the dmp ligand upon photoexcitation is similar to the charge difference at the copper center between the ground-state copper(I) and copper(II) complexes.
Journal Article↗
[The investigation of clinical images of 88 hospital staff with SARS].
OBJECTIVE: To investigate the clinical thoracic images of hospital staff with SARS. METHODS: Thoracic images was analyzed in 88 medical workers with SARS, including 394 chest plain films and 9 CT scans. RESULTS: The typical signs of SARS are multifocal air-space consolidations, and progress over a day from small shadow to becoming generalized. CONCLUSION: Thoracic plain film was necessary for diagnosis of SARS, CT could detect the pulmonary abnormality of SARS early.
Adult↗
A novel microgravimetric DNA sensor with high sensitivity.
A novel method using an amplifier with a cantilever and gold nanoparticles successfully to extend the length of the target for the specific and high sensitive detection of DNA was reported. When the size of gold nanoparticle is 50 nm, a sensitivity of 10(-15)M for the single base mutation detection has been achieved.
Base Sequence↗
The role of hMLH3 in familial colorectal cancer.
Hereditary nonpolyposis colorectal cancer (HNPCC) is commonly associated with at least three currently known DNA mismatch repair genes: (a) hMSH2; (b) hMLH1; and (c) hMSH6. A majority of HNPCC families has identifiable mutations in hMLH1 and hMSH2. When these mutations cause an inherited risk of colorectal cancer, they are also most often associated with microsatellite instability in the tumors. Recently, hMLH3 was suggested to be causative in HNPCC. We screened 70 index patients suggestive of a genetic predisposition for germ-line mutations in hMLH3 with denaturing high-performance liquid chromatography. One frameshift mutation and 11 missense mutations were identified in 16 index patients (23%). Most families presented evidence against hMLH3 as a high risk factor in familial colorectal cancer, and most of the mutations were found in the low risk patients, suggesting hMLH3 to be a low risk gene for colorectal cancer. We demonstrate in one family that a hMLH3 mutation segregated with disease together with a missense mutation in hMSH2, which makes us hypothesize that these mutations work together in an additive manner and result in an elevated risk of colorectal tumors in the family. None of the tumors with hMLH3 mutations showed microsatellite instability, which demonstrates that hMLH3 does not make its contribution to carcinogenesis through an impaired DNA mismatch repair function.
Carrier Proteins↗
A new approach to suppress nonlinearity-transparency trade-off through coordination chemistry: syntheses and spectroscopic study on second-order nonlinear optical properties of a series of square-pyramidal zinc(II) complexes.
Five new square-pyramidal coordination compounds L x Zn(acac)(2) (1-5) (acac = acetylacetonate; L is a variety of thiosemicarbazones: p-dimethylaminobenzaldehyde thiosemicarbazone (1), p-hydroxy-o-methoxybenzaldehyde thiosemicarbazone (2), p-methoxybenzaldehyde thiosemicarbazone (3), p-hydroxybenzaldehyde thiosemicarbazone (4), o-hydroxybenzaldehyde thiosemicarbazone (5)) have been synthesized and characterized by 1H NMR, IR, and elemental analysis. All of these compounds exhibit pretty wide transparent ranges in the visible region. Their electronic absorption spectra have been studied experimentally, and theoretically by ZINDO/S calculation. The latter has also been utilized to estimate the extent of intramolecular charge transfer. The MOPAC software package has been used to evaluate their first-order molecular hyperpolarizabilities (beta). All beta values of the five coordination compounds are larger than those of the corresponding thiosemicarbazones. And complex 1 shows the largest beta(0) (39.1 x 10(-30) esu) in the series.
Magnetic Resonance Spectroscopy↗
Large-scale delineation of secreted protein biomarkers overexpressed in cancer tissue and serum.
Genetic alterations in tumor cells often lead to the emergence of growth-stimulatory autocrine and paracrine signals, involving overexpression of secreted peptide growth factors, cytokines, and hormones. Increased levels of these soluble proteins may be exploited for cancer diagnosis and management or as points of therapeutic intervention. Here, we combined the use of controlled vocabulary terms and sequence-based algorithms to predict genes encoding secreted proteins from among approximately 12,500 sequences represented on oligonucleotide microarrays. Expression of these genes was queried in 150 carcinomas from 10 anatomic sites of origin and compared with 46 normal tissues derived from the corresponding sites of tumor origin and other body tissues and organs. Of 74 different genes identified as overexpressed in cancer tissues, several encode proteins with demonstrated clinical diagnostic application, such as alpha-fetoprotein in liver carcinoma, and kallikreins 6 and 10 in ovarian cancer, or therapeutic utility, such as gastrin-releasing peptide/bombesin in lung carcinomas. We show that several of the other candidate genes encode proteins with high levels of tumor-associated expression by immunohistochemistry on tissue microarrays and further demonstrate significantly elevated levels of another novel candidate protein, macrophage inhibitory cytokine 1, a distant member of the transforming growth factor-beta superfamily, in the serum of patients with metastatic prostate, breast, and colorectal carcinomas. Our results suggest that the combination of annotation/protein sequence analysis, transcript profiling, immunohistochemistry, and immunoassay is a powerful approach for delineating candidate biomarkers with potential clinical significance and may be broadly applicable to other human diseases.
Biomarkers, Tumor↗
Ammonia inhibition on thermophilic anaerobic digestion.
This study evaluated both chronic and acute toxicity of ammonia in thermophilic anaerobic digestion of synthetic wastewater over a range of acclimation concentrations. The inhibition effects of ammonia, in terms of total ammonia nitrogen (TAN), under various pH values and acclimation conditions on thermophilic aceticlastic methanogens were investigated. Completely mixed thermophilic anaerobic reactors operated at a chemical oxygen demand (COD) loading rate of 4 g/lday and a solid retention time (SRT) of 7 days were subjected to TAN concentrations of 0.40, 1.20, 3.05, 4.92, and 5.77 g/l. The reactor operations presented a case of chronic inhibition and it was observed that TAN concentrations of 4.92 and 5.77 g/l caused a drop in methane production by as much as 39% and 64%, respectively with respect to control. Batch anaerobic toxicity assays (ATA) were also performed to evaluate the acute toxicity effects of TAN and pH on methanogenesis at thermophilic condition. Modeling based on the results of ATA indicated that aceticlastic methanogens acclimated to high concentrations of TAN were less sensitive to increase in TAN and could tolerate wider pH ranges. TAN concentration causing 100% inhibition occurred in the range of 8-13 g/l, depending on acclimation condition and system pH.
Acclimatization↗
Orthotopic hindlimb transplantation in the mouse.
There are many potential advantages to using a mouse as a model for composite tissue transplantation, particularly to examine the mechanisms behind various tolerance induction protocols. The purpose of this study was to evaluate the reliability of a new hindlimb transplant model in the mouse. Fifteen Swiss-Webster mice, 14 to 16 weeks old (35 to 50 g), had syngeneic hindlimb transplants performed. The donor limb was attached to the recipient limb stump first by bony fixation using an intramedullary rod (22-gauge needle, 2.5 mm in length). The venous anastomosis was performed across a stent fashioned from a 27-gauge nylon I.V. catheter tip cover and secured with two simple ties using 10-0 nylon. The arterial anastomosis was performed with interrupted 11-0 nylon stitches. Eleven of the fifteen transplanted limbs survived for the duration of the study (30 days). All four failures occurred within 4 hr postoperatively, (venous thrombosis, n = 2; arterial thrombosis, n = 2). Clamp time decreased throughout the study, averaging 56 min for the final four transplants and 88 min total operative time. Orthotopic hindlimb transplantation can be reliably achieved in a mouse. The mouse model should be useful to the future study of composite tissue allotransplantation.
Anastomosis, Surgical↗
[Retrospective study of the relationship of height difference and bone density of postmenopausal women].
OBJECTIVE: To analyze the relationship of the height difference and bone density (BD) of premenopausal and postmenopausal women. METHODS: The height values of 191 premenopausal and postmenopausal women were recorded, and the BD values of lumbar vertebrae and hip were detected by double energy X-ray BD detector. RESULTS: The lower the height of the postmenopausal women, the less the BD value. The BD of lumbar vertebrae dropped 0.025 5 g/cm(2) with each 2 cm of the shortened height, and the BD of hip joint dropped 0.029 2 g/cm(2). The shortened value in postmenopausal women with osteoporosis was statistically greater than that in postmenopausal women without osteoporosis. CONCLUSION: The BD of the postmenopausal women can be estimated by the calculation of their shortened height value.
Aged↗
[Experience of Professor Li Guo-Heng in treating degenerative osteoarthrosis of knee joint].
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Female↗
[Improved method of epalrestat synthesis].
OBJECTIVE: To synthesize epalrestat and to improve the method of synthesis. METHODS: Glycine reacted with carbondisulfide,then with ClCH(2)COONa to give 3-carboxymethylrhodanine. PhCHO reacted with CH(3)CH(2)CHO in NaOH/EtOH solution to produce 2-methylcinnamaldehyde.3-carboxymethylrhodanine and 2-methylcinnamaldehyde were treated with NH(3).H(2)O to obtain epalrestat. RESULT: The described method was effective in synthesis of Epalrestat and the yield was higher than that of in references. CONCLUSION: The results suggest that this method is suitable for industrial production.
Aldehyde Reductase↗
[Improved method of fluvoxamine synthesis].
OBJECTIVE: To modify the synthetic method of fluvoxamine. METHODS: Fluvoxamine was synthesized from 4-trifluoromethylbenzonitrile by the steps of Grignard reaction, hydrolysis and oximation. RESULT: The chemical structure of the synthesized product was confirmed by (1)HNMR, and the total yield reached to 36.16%. CONCLUSION: The results indicate that the synthetic route is practical.
Fluvoxamine↗
MIC-1 serum level and genotype: associations with progress and prognosis of colorectal carcinoma.
PURPOSE: Macrophage inhibitory cytokine-1 (MIC-1) is a divergent member of the tumor growth factor beta (TGF-beta) superfamily. Several observations suggest that it plays a role in colorectal carcinoma (CRC). In particular, MIC-1 is markedly up-regulated in colorectal cancers as well as in premalignant adenomas. This study examines the relationship of serum MIC-1 levels and genotypes to clinical and pathologic features of colonic neoplasia. EXPERIMENTAL DESIGN: We confirmed the presence of MIC-1 in CRC tissue and the cell line CaCo-2. The normal range for serum MIC-1 levels was defined in 260 healthy blood donors, and the differences between normal subjects and 193 patients having adenomatous polyps or CRC were then determined. In a separate cohort of 224 patients, we evaluated the relationship of MIC-1 serum level and genotype to standard tumor parameters and outcome measures. RESULTS: MIC-1 was expressed in CRC tissue and the cancer cell line CaCo-2. There was a progressive increase in serum MIC-1 levels between normal individuals [mean (M) = 495 pg/ml, SD = 210), those with adenomatous polyps (M = 681 pg/ml, SD = 410), and those with CRC (M = 783 pg/ml, SD = 491)]. Serum MIC-1 level was correlated with the extent of disease so that the levels were higher in patients with higher Tumor-Node-Metastasis stage. There were significant differences in time to relapse and overall survival between subjects with different MIC-1 levels and genotypes. CONCLUSIONS: This study identifies a strong association between MIC-1 serum levels and neoplastic progression within the large bowel. We suggest that the measurement of serum MIC-1 levels and determination of MIC-1 genotype may have clinical use in the management of patients with CRC.
Adenoma↗
Hypertonic perfusion reduced myocardial injury during subsequent ischemia and reperfusion in normal and hypertensive rats.
AIM: To determine the effects of hypertonic solution on myocardial ischemia and reperfusion injury in normal and stroke-prone hypertensive rat hearts in vitro. METHODS: Hearts were perfused in an isolated-perfused Langendorff apparatus and perfused with normal or hypertonic solution (360 mOsm/L, by addition of NaCl to the normal perfusate of 300 mOsm/L) before subjected to 30 min ischemia followed by 40 min isotonic reperfusion. Heart function, myocardial creatine kinase leakage, norepinephrine release, and ventricular calcium content were determined. RESULTS: Normal rat hearts with hypertonic perfusion showed higher recovery rate of spontaneous beating than control hearts after ischemia. Hypertensive rat hearts perfused with hypertonic solution also had better recovery in diastolic function and less creatine kinase leakage than hypertensive controls. Concomitantly, myocardial release of norepinephrine was also reduced from hypertensive hearts perfused with hypertonic solution. There was no significant difference in myocardial calcium content between normal and hypertonic perfused hypertensive hearts. CONCLUSION: Hypertonic perfusion may precondition the hearts and protect them from ischemia and reperfusion injury in both normal and hypertensive rats. The modulation of hypertonic perfusion on myocardial norepinephrine release and its role in cardioprotection needs further investigation.
Animals↗