[Results of nutrition intervention trials].
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Humans↗
Biomedical subjects
Y Wu
Publications and source records attributed to Y Wu.
[Protective effects of beta-carotene liposome against rat neutrophile membrane damage caused by intra- or extra-cellular reactive oxygen species].
In this experiment the protective effects of beta-carotene (beta-C) liposome against rat neutrophile membrane damage caused by extracellular or intracellular reactive oxygen were species (ROS) investigated by means of fluorescence labels 1, 6-diphenyl-1,3,5 hexatriane (DPH) and N-(3-pyrene) maleimide (N-(3p)M). The extracellular ROS include the singlet oxygen (1O2) generated by photoreaction of sensitizer rosebengal and the superoxide anion (O2-.) produced by xanthine/xanthine oxidase reactive system. The intracellular ROS was sensitizer rosebengal and superoxide anion (O2-.) produced by xanthine/xanthine oxidase reactive system while the intracellular oxygen was generated by stimulating neutrophile respiratory burst with opsonized zymosan. No change in the peak or shape of fluorescent excitation and emission spectra was found for either of the two labels. The results of fluorescent polarization value in the membrane showed that beta-C liposome could significantly inhibit the damage of rat neutrophile membrane protein reacted either by intracellular generated reactive oxygen species or by extracellular generated O2-. or 1O2. It could also inhibit the injury of the rat neutrophile membrane lipid reacted by extracellular reactive oxygen species. However, the protective effects of beta-C liposome against membrane lipid damage reacted by intracellular reactive oxygen species by at the same concentration as those on membrane protein were not significant, which could be partly explained by relatively higher damage level of rat neutrophile membrane lipid domain reacted by intracellular reactive oxygen species than that of the membrane protein domain.
Animals↗
[Synthesis of polyfunctional bridging agent-tetrakis (omega-hydroxyproxymethyl) methane and tri (hydroxyproxymethyl) amino methane].
In order to look for the polyfunctional bridging agent. Tetrakis (omega-hydroxyproxymethyl) methane (3) and Tri (omega-hydroxyproxymethyl) aminomethane (4) were prepared from pentaerythritol and trihydroxymethylamino methane respectly. Nine derivatives (5-13) of compounds (3) and (4) were synthesized. The structures of all new compounds (5-13, 15) were confirmed by IR, 1H-NMR and elemental analysis.
Bridged-Ring Compounds↗
[An estimate of recurrence risk for neural tube defects in China].
A retrospective survey was made for estimating the recurrence risk of neural tube defects (NTD) in 233 hospitals of China during the period from July 1990 to June 1993. A total of 2159 women who born a baby with NTD in this pregnancy were investigated. Among them, 674 had one or more previous births (total in 889 births) before this pregnancy. Of the 889 children, 61 had NTD. Thus the overall estimate recurrence risk of NTD is 6.86%. The estimate recurrence risk of NTD is correlated with the prevalence. The estimate recurrence risks are 3.70%, 4.50% and 8.32% in the low-, average and high-prevalence areas respectively. There is a high recurrence risk for the same defect (anencephaly of spina bifida or encephalocele) of the index case.
Anencephaly↗
[Gas chromatographic analysis of molinate residue in rice].
We have developed a method for determining molinate residue in rice by gas chromatography. In our study, the rice sample was extracted with acetonewater (1 + 1). After filtering, the filtrate was acidified to pH 3.0-3.5 and re-extracted with petroleum. The extract was cleaned up on a florisil column and followed by analysis with GC/FPD. The linear range of the method was 0-5 micrograms/ml. the detection limit was 0.013 mg/kg for a rice sample of 20 g. The average recoveries of spiked samples ranged from 87.0%-96.7%. The relative deviation standard was less than 5.7%. The experimental verification of this method by extramural departments and its application to determination of rice samples demonstrate that this method is sensitive, reliable and suitable for analysis of molinate residue in rice.
Azepines↗
[Observation of the anastomoses of intrahepatic veins in normal men].
The purpose of this study is to identify the existence of hepatovenous intrahepatic anastomosis in normal men. A total of thirteen livers were investigated during the early autopsies of normal men who died in accidents. Perfusion venography of branches of hepatic veins using meglucamine diatrizoate was done in six cases; this method we used had not been reported in the literature. In one case, portal venography was performed. And in the other six cases, liver substance staining was done by injecting the ink through the middle hepatic vein, and such staining of the liver was observed by light microscope. The results show, (1) there are intrahepatic anastomoses between the hepatic veins within the liver; (2) there are anastomoses between the middle hepatic vein and the accessory hepatic veins; and (3) shunts exist between portal veins and hepatic veins. The above findings provide an anatomical basis for the performance of irregular hepatectomy and the rationale for one or two hepatic veins ligation should such veins were traumatized or invaded by liver cancer.
Adult↗
[Inotropic effect of novel cardiotonic agent, vesnarinone--tests on anaesthetized dogs].
We studied the positive inotropic effect of the novel cardiotonic agent, vesnarinone on open chest and intact anaesthetized dogs hearts. The results indicate that vesnarinone has a dose-effect relationship on increasing the contractile force, LV dp/dt max and stroke volume, and it shortens the ejection time 21%. No effect on blood pressure and heart rate was noted. Vesnarione is more effective than amrinone in terms of positive inotropic effect.
Animals↗
[The relationship between the retinal lipid peroxidation or antioxidation and age in rats].
OBJECTIVE: To investigate the relationship between the retinal lipid peroxidation (LPO) or antioxidation and age. METHODS: The thiobarbituric acid (TBA) and chemical luminescence methods, were used to detect the retinal malondialdehyde (MDA) content produced by LPO and superoxide dismutase (SOD) activity which represents the antioxidation ability of retina in 22 rats different ages. RESULTS: The retinal MDA contents were 0.18 +/- 0.06, 0.16 +/- 0.06, 0.38 +/- 0.11, 0.49 +/- 0.09 nmol/mg protein respectively in 5, 12, 18, 24 months old (F test, P < 0.01); the retinal SOD activities were 0.99 +/- 0.30, 2.48 +/- 0.56, 0.70 +/- 0.35, 0.85 +/- 0.57 U/mg protein respectively in 5, 12, 18, 24 months old rats (F test, P < 0.01). CONCLUSIONS: The retinal MDA content increased and SOD activity decreased with aging. The cumulative effects of the long-term photochemical damage and decreased antioxidation ability in retina might be the causes of the increased retinal LPO.
Aging↗
[Histochemical study of lectin receptor and cell morphometric analysis on oral leukoplakias, epithelial dysplasia and squamous carcinoma].
The histochemical study of lectin receptor and the cell morphometric analysis were applied to cases to oral mucosal leukoplakias in order to find the differences between abnormal and normal cells in premalignant tissues. Results showed that the cell morphological change and glycosyl change of the cell surface in leukoplakias with severe epithelial dysplasia were similar to those of carcinoma, which suggests that the above methods may be used to differentiate the degree of the epithelial dysplasia of oral mucosal leukoplakias.
Carcinoma, Squamous Cell↗
[Chemical constituents of Ligusticum brachylobum Franch].
From the roots of Ligusticum brachylobum, which is used as a substitute for traditional Chinese medicine Radix Peucedani in the southwest of China, 5 compounds were isolated and identified as umbelliferone, selinidin, anomalin, nodakenin and ferulic acid.
Apiaceae↗
Variety of molecular conformation of plasmid pUC18 DNA and solenoidally supercoiled DNA.
The plasmid pUC18 DNA isolated from Escherichia coli HB101 were analyzed by two-dimensional agarose gel electrophoresis and hybridization. The results show that the DNA sample can be separated into six groups of different structural components. The plectonemically and solenoidally supercoiled pUC18 DNA coexist in it. These two different conformations of supercoiled DNA are interchangeable with the circumstances (ionic strength and type, etc.). The amount of solenoidally supercoiled pUC18 DNA in the samples can be changed by treatment of DNA topoisomerases. Under an electron microscope, the solenoidal supercoiling DNA has a round shape with an average diameter of 45 nm. The facts suggest that solenoidally supercoiled DNA be a structural entity independent of histones. The polymorphism of DNA structure may be important to packing of DNA in vivo.
DNA Topoisomerases, Type I↗
[Hypoglycemic effect of Rhodiola sachalinensis A. Bor. polysaccharides: comparison of administration in different ways].
When Rhodiola sachalinensis polysaccharides A and B (RSP A and RSP B) were intraperitoneally injected to mice at dosages of 50 mg/kg and 100 mg/kg, the result showed that RSP B was the effective hypoglycemic ingredient of Rhodiola sachalinensis. When mice were administrated in different ways, it was shown that RSP B did not possess significant hypoglycemic effect through absorption in the instestines. However, RSP B does possess significant hypoglycemic effect if administrated subcutaneously, intramuscularly, intraperitoneally and intravenously.
Animals↗
Recombinant human liver medium-chain acyl-CoA dehydrogenase: purification, characterization, and the mechanism of interactions with functionally diverse C8-CoA molecules.
We offer a large scale purification procedure for the recombinant human liver medium-chain acyl-CoA dehydrogenase (HMCAD). This procedure routinely yield 100-150 mg of homogeneous preparation of the enzyme from 80 L of the Escherichia coli host cells. A comparative investigation of kinetic properties of the human liver and pig kidney enzymes revealed that, except for a few minor differences, both of these enzymes are nearly identical. We undertook detailed kinetic and thermodynamic investigations for the interaction of HMCAD-FAD with three C8-CoA molecules (viz., octanoyl-CoA, 2-octenoyl-CoA, and 2-octynoyl-CoA), which differ with respect to the extent of unsaturation of the alpha-beta carbon center; octanoyl-CoA and 2-octenoyl-CoA serve as the substrate and product of the enzyme, respectively, whereas 2-octynoyl-CoA is known to inactivate the enzyme. Our experimental results demonstrate that all three C8-CoA molecules first interact with HMCAD-FAD to form corresponding Michaelis complexes, followed by two subsequent isomerization reactions. The latter accompany either subtle changes in the electronic structures of the individual components (in case of 2-octenoyl-CoA and 2-octynoyl-CoA ligands), or a near-complete reduction of the enzyme-bound flavin (in case of octanoyl-CoA). The rate and equilibrium constants intrinsic to the above microscopic steps exhibit marked similarity with different C8-CoA molecules. However, the electronic structural changes accompanying the 2-octynoyl-CoA-dependent inactivation of enzyme is 3-4 orders of magnitude slower than the above isomerization reactions. Hence, the octanoyl-CoA-dependent reductive half-reaction and the 2-octynoyl-CoA-dependent covalent modification of the enzyme occur during entirely different microscopic steps. Arguments are presented that the origin of the above difference lies in the protein conformation-dependent orientation of Glu-376 in the vicinity of the C8-CoA binding site.
Acyl Coenzyme A↗
Rapid induction of a novel costimulatory activity on B cells by CD40 ligand.
BACKGROUND: T cells and B cells communicate by direct cell--cell interaction that is crucial to the functioning of the immune system. It is well established that the interaction between B-cell-expressed CD40 and T-cell-expressed CD40 ligand (CD40L) is critical for T-cell-dependent antibody responses, but the role of this interaction in T-cell responses is less clear. In this study, we have used mice with targeted mutations in the genes encoding CD40L or CD28 to investigate how the CD40-CD40L interaction induces on B cells a costimulatory activity that acts in addition to antigen to trigger T-cell growth. RESULTS: We show that T cells from Cd40L-deficient mice induce a substantially reduced costimulatory activity on B cells compared to wild-type T cells, particularly at early time points. Surprisingly, T cells, from CD40L-deficient mice induce similar levels of B7-1 and B7-2 as do wild-type T cells. We further show that the CD40L-mediated induction of costimulatory activity precedes the induction of B7-1, B7-2 and the heat-stable antigen (HSA). CD4 T cells isolated from the CD28-deficient mice can receive costimulatory activity from CD40L-induced B cells, demonstrating that the induced molecules can costimulate T cells by a CD28-independent mechanism. We have generated a novel monoclonal antibody that inhibits the CD40L-induced costimulatory activity. Expression of the epitope detected by this monoclonal antibody correlates with the induction of the costimulatory activity, and the molecule recognized by the monoclonal antibody is a single chain of around 85 kDa, distinct from B7-1, B7-2, ICAM-1, ICAM-2, ICAM-3, HSA CD5, integrin and 4-1BB ligand. CONCLUSIONS: Our results demonstrate that CD40L is both necessary and sufficient for rapid, T-cell-mediated induction of costimulatory activity on B cells. This costimulatory activity is distinct from B7-1 and B7-2, and is independent of CD28.
Animals↗
Signaling by a new anti-Thy 1 monoclonal antibody inhibits T cell proliferation and interferes with T-cell-mediated induction of costimulatory molecule B7-2.
Costimulatory activity on antigen-presenting cells is a critical determinant of the fate T cells when the T cell receptors are engaged by MHC:peptide complexes. Therefore, control of the expression of the costimulatory molecules regulates T cell responses. While several types of interactions between T cells and B cells up-regulate costimulatory molecules on antigen-presenting cell, no T cell surface molecules have been implicated in inhibiting the induction of the costimulatory molecules on B cells. Here we characterize a new anti-Thy1 mAb, 21F10, which inhibits T cell proliferation to selective stimuli. T cells stimulated by anti-CD3 together with anti-Thy1 mAb are anergic to further stimulation through the CD3, which suggests that the anti-Thy1 mAb interferes with the delivery of the costimulatory activity to T cells. Consistent with this notion, anti-Thy1 mAb 21F10 completely inhibits the induction of B7-2 on B cells. Induction of several T cell surface molecules such as CD69 and CD40 ligand was largely unaffected. As this inhibition requires a bivalent anti-Thy1 mAb and does not require binding of more than 50% of Thy1 molecules on T cell surface, we suggest that Thy1 may mediate a negative signaling pathway which inhibits the T-cell-mediated induction of costimulatory activity, including expression of co-stimulatory molecule B7-2.
Animals↗
Detection and expression of the 70 kDa heat shock protein SSB1P at different temperatures in Saccharomyces cerevisiae.
Ssb1p and ssb2p are two members of the hsp70 family in yeast. Up to now there has been no evidence to indicate any differences between these two members of the hsp70 family, and it was suggested that ssb1p and ssb2p were 99% identical. Here we show that an antibody prepared against the C-terminal domain of human hsp71 recognizes specifically ssb1p out of the eight hsp(c)70s in Saccharomyces cerevisiae. An amino acid peptide sequence at the C-terminal end (VTATDKSTGK) is suggested to be the sequence which has high homology between ssb1p and hu-hsp71 and to be responsible for the specificity of recognition of this unique member of the hsp70 family. Using this antibody in immunoblot assays, we have determined the cellular content of ssb1p after heat shock and at different growth temperatures. Ssb1p is shown to be degraded during heat shock treatment while it shows a higher level of expression at low temperatures.
Amino Acid Sequence↗
A study of the intracellular routing of cytotoxic ribonucleases.
Several ribonucleases serve as cytotoxic agents in host defense and in physiological cell death pathways. Although certain members of the pancreatic ribonuclease A superfamily can be toxic when applied to the outside of cells, they become thousands of times more toxic when artificially introduced into the cytosol, indicating that internalization is the rate-limiting step for cytotoxicity. We have used three agents that disrupt the Golgi apparatus by distinct mechanisms, retinoic acid, brefeldin A, and monensin, to probe the intracellular pathways ribonucleases take to reach the cytosol. Retinoic acid and monensin potentiate the cytotoxicity of bovine seminal RNase, Onconase, angiogenin, and human ribonuclease A 100 times or more. Retinoic acid-mediated potentiation of ribonucleases is completely blocked by brefeldin A. Ribonucleases appear to route more efficiently into the cytosol through the Golgi apparatus disrupted by monensin or retinoic acid. Intracellular RNA degradation by BS-RNase increased more than 100 times in the presence of retinoic acid confirming that the RNase reaches the cytosol and indicating that degradation of RNA is the intracellular lesion causing toxicity. As retinoic acid alone and Onconase are in clinical trials for cancer therapy, combinations of RNases and retinoic acid in vivo may offer new clinical utility.
Amino Acid Sequence↗
Protease assay based on magnetic beads.
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Amino Acid Sequence↗