Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0432222 (SEM)
 47,337 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Apoptosis has been shown in cardiac cells under divergent physiological and pathological conditions. However, there has been an ongoing debate upon the relative contribution of cardiomyocyte apoptosis to the myocardial infarct size after ischemia-reperfusion (I-R) injury. We tested the hypothesis that blocking the death receptor pathway of apoptosis through genetic deletion of Fas receptors or Fas ligands would reduce myocardial infarct size caused by acute I-R injury. The hearts isolated from Fas receptor or Fas ligand knockout (KO) mice as well as the C57BL/6J wild-type control mice (N = 6-8 per group) were subjected to 20 min of global ischemia and 30 min of reperfusion in Langendorff mode. Our results show that the infarct size, determined with triphenyltetrazolium chloride staining, was not significantly different between the three groups (i.e., 30.2 +/- 3.9% for wild-type controls, 30.0 +/- 2.1% for Fas ligand KOs, and 23.8 +/- 3.6% for Fas receptor KOs; mean +/- SEM, p > 0.05). Postischemic leakage of lactate dehydrogenase, another marker of necrotic cellular injury, also was not significantly different between these groups (p > 0.05). In addition, postischemic ventricular contractile function as well as coronary flow were similar for all the experimental groups (p > 0.05). In conclusion, contrary to our original hypothesis, the present study in the gene KO mice suggests that the Fas ligand- and Fas receptor-mediated death receptor pathway of apoptosis is not the primary determinant of myocardial infarct size and ventricular dysfunction caused by acute global I-R injury in the isolated perfused mouse heart.
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PMID:Genetic deletion of fas receptors or Fas ligands does not reduce infarct size after acute global ischemia-reperfusion in isolated mouse heart. 1645 39

Unpolymerized resin (co)monomers or mercury (Hg) can be released from restorative dental materials (e.g. composites and amalgam). They can diffuse into the tooth pulp or the gingiva. They can also reach the gingiva and organs by the circulating blood after the uptake from swallowed saliva. The cytotoxicity of dental composite components hydroxyethylmethacrylate (HEMA), triethyleneglycoldimethacrylate (TEGDMA), urethanedimethacrylate (UDMA), and bisglycidylmethacrylate (Bis-GMA) as well as the amalgam component Hg(2+) (as HgCl(2)) and methyl mercury chloride (MeHgCl) was investigated on human gingival fibroblasts (HGFs) at two time intervals. To test the cytotoxicity of substances, the bromodeoxyuridine (BrdU) assay and the lactate dehydrogenase (LDH) assay were used. The test substances were added in various concentrations and cells were incubated for 24 or 48 h. The EC(50) values were obtained as half-maximum-effect concentrations from fitted curves. Following EC(50) values were found [BrdU: mean (mmol/l); SEM in parentheses; n=12]: (24 h/48 h) HEMA 8.860 (0.440)/6.600(0.630), TEGDMA 1.810(0.130)/1.220(0.130), UDMA 0.120(0.010)/0.140(0.010), BisGMA 0.060(0.004)/0.040(0.002), HgCl(2) 0.015(0.001)/0.050(0.006), and MeHgCl 0.004(0.001)/0.005(0.001). Following EC(50) values were found [LDH: mean (mmol/l); SEM in parentheses; n=12]: (24 h/48 h) HEMA 9.490(0.300)/7.890(1.230), TEGDMA 2.300(0.470)/1.950(0.310), UDMA 0.200(0.007)/0.100(0.007), BisGMA 0.070(0.005)/0.100(0.002), and MeHgCl 0.014(0.006)/0.010(0.003). In both assays, the following range of increased toxicity was found for composite components (24 and 48 h): HEMA < TEGDMA < UDMA < BisGMA. In both assays, MeHgCl was the most toxic substance. In the BrdU assay, Hg(2+) was about fourfold less toxic than MeHgCl but Hg(2+) was about fourfold more toxic than BisGMA. In the BrdU test, a significantly (P<0.05) decreased toxicity was observed for Hg(2+) at 48 h, compared to the 24 h Hg(2+)-exposure. A time depending decreased toxicity was observed only for Hg(2+) which can then reach the toxic level of BisGMA.
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PMID:Cytotoxicity of dental composite (co)monomers and the amalgam component Hg(2+) in human gingival fibroblasts. 1647 58

In this study, self-designed bifunctional RGD-containing fusion protein (BFP) was grafted on the petri dish to evaluate its cytotoxicity and attachment efficiency on primary cultured keratinocytes and dermal fibroblasts. Two lengths of the GRGDS sequences were separately fused to the N-terminus and C-terminus of the Trichoderma koningii cellobiohydrolase I gene cellulose-binding domain, to serve as linking molecule between the cell and the substrate. The grafting procedure was no more labor-intensive and could be done just in aqueous condition itself. The epidermal keratinocytes and dermal fibroblasts, harvested and separated from human foreskin, were cultured in serum-free keratinocyte culture medium and DMEM, respectively. The BFP was dissolved in double-deionized water, and was prepared at different concentrations. The BFP solution was subsequently added into the petri dish for grafting. MTT assay, total DNA measurement, and lactate dehydrogenase analysis were used to evaluate the cell viability, cell proliferation, and cytotoxicity. The immunochemical stain and SEM examination were chosen to make sure that the cultured cells still kept in phenotype. The results showed that the self-designed BFP was successfully coated on the petri dish to improve the cells' adhesion. The whole coating procedure was just done in aqueous solution without any organic solvent being involved. This method was much simpler than the traditional one, and there was no possibility to damage the immobilized biomolecules. From the results of the study, BFP could enhance attachment of keratinocytes and dermal fibroblasts without losing normal cell morphology and keep keratinocytes on the desired differentiation pathway. We believe that coating BFP on petri dish not only enhanced the keratinocyte attachment but also promoted keratinocytes proliferation. We suggest that the self-designed BFP has a great potential to apply on surface modification for the tissue-engineering scaffolds in the future.
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PMID:The effect of self-designed bifunctional RGD-containing fusion protein on the behavior of human keratinocytes and dermal fibroblasts. 1664 72

CXCR4 chemokine receptors retain hematopoietic progenitors and leukemia cells within the marrow microenvironment. We prospectively evaluated the prognostic implication of CXCR4 in 90 consecutive patients with acute myelogenous leukemia (AML) by flow cytometry. Patients were divided into groups with low (n=32), intermediate (n=26), or high (n=32) CXCR4 expression, as defined by CXCR4 mean fluorescence intensity ratio thresholds of less than 5, 5 to 10, or more than 10, respectively. We found that low CXCR4 expression on AML cells correlated with a better prognosis, resulting in a longer relapse-free and overall survival of 24.3+/-2.9 months for low CXCR4-expressing patients, compared with 17.4+/-3.4 months for intermediate and 12.8+/-2 months (mean+/-SEM) for patients with high expression. In univariate analyses, CXCR4 expression, cytogenetics, white blood cell count, and serum lactate dehydrogenase (LDH) predicted for shorter survival. Multivariate analysis revealed CXCR4 expression and unfavorable cytogenetics as independent prognostic factors. We conclude that CXCR4 expression in AML is an independent prognostic predictor for disease relapse and survival that can rapidly and easily be determined at disease presentation. These findings warrant further investigation into the role of CXCR4 in AML and suggest that CXCR4 should be incorporated into the risk assessment of AML patients.
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PMID:CXCR4 is a prognostic marker in acute myelogenous leukemia. 1688 90

The direct electrochemistry of lactate dehydrogenase (LDH) immobilized in silica sol-gel film on gold electrode was investigated, and an obvious cathodic peak at about -200 mV (versus SCE) was found for the first time. The LDH-modified electrode showed a surface controlled irreversible electrode process involving a one electron transfer reaction with the charge-transfer coefficient (alpha) of 0.79 and the apparent heterogeneous electron transfer rate constant (K(s)) of 3.2 s(-1). The activated voltammetric response and decreased charge-transfer resistance of Ru(NH(3))(6)(2+/3+) on the LDH-modified electrode provided further evidence. The surface morphologies of silica sol-gel and the LDH embedded in silica sol-gel film were characterized by SEM. A potential application of the LDH-modified electrode as a biosensor for determination of lactic acid was also investigated. The calibration range of lactic acid was from 2.0 x 10(-6) to 3.0 x 10(-5) mol L(-1) and the detection limit was 8.0 x 10(-7) mol L(-1) at a signal-to-noise ratio of 3. Finally, the effect of environmental pollutant resorcinol on the direct electrochemical behavior of LDH was studied. The experimental results of voltammetry indicated that the conformation of LDH molecule was altered by the interaction between LDH and resorcinol. The modified electrode can be applied as a biomarker to study the pollution effect in the environment.
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PMID:Direct electrochemistry of lactate dehydrogenase immobilized on silica sol-gel modified gold electrode and its application. 1786 89

Corneal wound healing is one of the major issues in ocular surface reconstruction and ocular surface diseases. Amniotic membrane (AM) transplantation is an excellent treatment modality to promote corneal wound healing and treat corneal diseases. It is interesting and valuable to search for another synthetic and biocompatible substitute for the study of mechanism of AM and the treatment of ocular surface disorders. Chitosan, the second-most abundant polymer in nature, has many biological advantages such as biocompatibility, biodegradability, hemostatic activity, and wound-healing property to be used as biomedical applications. The purpose of this project is to evaluate the phenotype of cultured corneal epithelial cells in vitro on synthetic chitosan membrane (CM). We cultivated bovine corneal epithelial cells on CM and AM, and then evaluated their phenotypes. The viability of the respective cell cultures was investigated using the 3-[4,5-dimethylrhiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) assay. The cytotoxicity of CM and AM to corneal epithelial cells was evaluated by lactate dehydrogenase (LDH) assay. The morphology of cultivated corneal epithelial cells on CM and AM was observed by scanning electron microscopy. Additionally, immunocytochemical stainings were used to confirm the phenotype of corneal epithelial cells. In MTT and LDH assays we found that the CM can support the growth of cultured corneal epithelial cells in good condition with minimal toxicity. The SEM and immunohistocytochemistry showed that the phenotype of corneal epithelial cells is compatible with that of AM. We conclude that the CM has the potential to be a suitable biomaterial for treating ocular surface disorders.
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PMID:The phenotype of bovine corneal epithelial cells on chitosan membrane. 1848 92

The promotion effect of titania nanoparticles (nano-TiO(2)) on the direct electron transfer between lactate dehydrogenase (LDH) and the silica sol-gel modified gold electrode was investigated by adding nano-TiO(2) (50 nm) in the modification process. This nano-TiO(2)-LDH electrode showed a pair of quasi-reversible cyclic voltammetry peaks with the formal potential of 70 mV (vs. SCE). Compared to the previous result of LDH modified electrode with only an irreversible cathodic peak, an anodic peak appeared and the cathodic peak potential shifted to the positive direction on this nano-TiO(2)-LDH electrode, which demonstrated that the direct electrochemistry of LDH was enhanced by nano-TiO(2). We supposed that the direct electrochemistry of LDH may be due to the redox reaction of some electroactive amino acids in the LDH molecule. The surface morphologies of electrodes characterized by SEM indicated that LDH was successfully immobilized on the sol-gel matrix and also had some interactions with nano-TiO(2). This electrode can be used as a biosensor for the determination of lactic acid. The calibration range of lactic acid was from 1.0 to 20 micromolL(-1) and the detection limit was 0.4 micromolL(-1). Meanwhile, the small K(m)(app) value (2.2 micromolL(-1)) suggested that LDH possessed high enzymatic activity and good affinity to lactic acid owing to the promotion effect of nano-TiO(2).
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PMID:The promotion effect of titania nanoparticles on the direct electrochemistry of lactate dehydrogenase sol-gel modified gold electrode. 1876 Nov 56

A system for vascular hollow fiber bio-artificial pancreas development, optimization and in vitro testing was implemented and operated in a simple and fully described manner, allowing other researchers to test a variety of experimental conditions (different biomaterials, biologic tissue, addition of proteins or other adjuvants). In this work, a polysulfone hollow fiber was used as bioprotective material. Two different cell sources were co-immobilized with agarose microspheres in and experimented with the membrane device: rat islets of Langerhans and mouse beta-TC-3 insulinoma cells. The results obtained with islets of Langerhans were used as islet comparable insulin-release data. Beta-TC-3 cells were mainly used in these studies, due to higher control and reproducibility of cell number and behavior: addition of hemoglobin was beneficial for sustained cell viability, especially during cell insertion in the device (viability assessed by beta-TC-3 lactate dehydrogenase activity in the recirculating culture medium); cells did not adhere to the polysulfone membrane (assessed by SEM observation of membrane samples from dynamic cultures). Comparable device functionality and insulin-release results were attained with both cell types: device functionality was maintained for 7-9 days and maximum insulin-release during dynamic glucose challenges were 2.6 x 10(-3)+/-7 x 10(-5)microU/beta-cell x 8 h, with islets, and 9.3 x 10(-4)+/-2 x 10(-5)microU/beta-cell x 2 h, with beta-TC-3 cells.
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PMID:Development of a polysulfone hollow fiber vascular bio-artificial pancreas device for in vitro studies. 1912 45

In recent times, Cr(III)(picolinate)(3) [Cr(III)(pic)(3)] a nutritional supplement, is gaining attention because of its clastogenic and mutagenic properties. Earlier studies of ours indicated that Cr(III)(pic)(3) is cytotoxic to lymphocytes with ROS and mitochondrial events playing a role in bringing about apoptosis. Now, we report that, autoschizis is induced in lymphocytes in a concentration and time dependent manner which is confirmed through TEM and SEM. Lymphocytes treated with concentrations of 100microM of Cr(III)(pic)(3) exhibit features such as cytoplasmic bleb, self excision of cytoplasm, cytoplasmic leakage and membrane bound bodies formed from the excised pieces apart from apoptosis and necrosis. Though autoschizis has been described in tumor cell lines treated with menadione and ascorbate, occurrence of this cell death in normal T-lymphocytes is reported here. The cellular events that accompany autoschizis are found to be increase in intracellular Reactive Oxygen Species (ROS) and cytoplasmic lactate dehydrogenase, loss of mitochondrial membrane potential (MMP) and depletion of ATP. Further, autoschizis is effected through increases in DNase I and DNase II activity with a concomitant decrease in caspase-3 activity which leads to a random cleavage of the DNA as demonstrated by a smear like pattern after electrophoresis on agarose gel.
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PMID:Autoschizis of T-cells is induced by the nutritional supplement, Cr(III)picolinate. 1985 52

In this paper, hydroxyapatite (HA) sol composed of nanosized HA particles was incorporated into collagen gel to regulate cell-mediated collagen contraction. Human bone marrow derived stromal cells (hMSCs) were cultured for 37 days in gels with HA to collagen ratios of 0:1, 0.5:1, 1:1, 1.5:1, and 2:1, respectively. The contraction of gels was evaluated by measuring diameter change with incubation time, and the microstructure of gels at the end of culture was visualized by SEM. The cytotoxicity of HA sol was evaluated according to the percentage of maximum lactate dehydrogenase (LDH) release from hMSCs. A combination of Hoechst 33342, propidium iodide, and calcein esters was used for imaging the live/dead cells and the distribution of loaded cells within the constructs. By incorporating HA sol into the collagen gel, the hMSCs medicated contraction was delayed and the extent of contraction was reduced as the proportion of HA relative to the collagen increased. Depending on the ratio of HA sol incorporated within the collagen gel, hMSC cells revealed different morphology and a change in the distribution of loaded cells within the gels. No significant cytotoxicity was noticed as a consequence of incorporating HA sol into the collagen lattice.
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PMID:Incorporation of hydroxyapatite sol into collagen gel to regulate the contraction mediated by human bone marrow-derived stromal cells. 1988 5


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