119 research outputs found
Tests of the random phase approximation for transition strengths
We investigate the reliability of transition strengths computed in the
random-phase approximation (RPA), comparing with exact results from
diagonalization in full shell-model spaces. The RPA and
shell-model results are in reasonable agreement for most transitions; however
some very low-lying collective transitions, such as isoscalar quadrupole, are
in serious disagreement. We suggest the failure lies with incomplete
restoration of broken symmetries in the RPA. Furthermore we prove, analytically
and numerically, that standard statements regarding the energy-weighted sum
rule in the RPA do not hold if an exact symmetry is broken.Comment: 11 pages, 7 figures; Appendix added with new proof regarding
violation of energy-weighted sum rul
Role of calcineurin in Porphyromonas gingivalis-induced myocardial cell hypertrophy and apoptosis
Background and objective: Periodontal pathogen Porphyromonas gingivalis (P. gingivalis) increased cardiomyocyte hypertrophy and apoptosis whereas Actinobaeillus actinomycetemcomitans and Prevotella intermedia had no effects. The purpose of this study is to clarify the role of calcineurin signaling pathway in P. gingivalis-induced H9c2 myocardial cell hypertrophy and apoptosis. Methods: DNA fragmentation, nuclear condensation, cellular morphology, calcineurin protein, Bcl2- associated death promoter (Bad) and nuclear factor of activated T cell (NFAT)-3 protein products in cultured H9c2 myocardial cell were measured by agarose gel electrophoresis, DAPI, immunofluorescence, and Western blotting following P. gingivalis and/or pre-administration of CsA (calcineurin inhibitors cyclosporin A). Results: P. gingivalis not only increased calcineurin protein, NFAT-3 protein products and cellular hypertrophy, but also increased DNA fragmentation, nuclear condensation and Bad protein products in H9c2 cells. The increased cellular sizes, DNA fragmentation, nuclear condensation, and Bad of H9c2 cells treated with P. gingivalis were all significantly reduced after pre-administration of CsA. Conclusion: Our findings suggest that the activity of calcineurin signal pathway may be initiated by P. gingivalis and further lead to cell hypertrophy and death in culture H9c2 myocardial cells
Roles of insulin-like growth factor II in cardiomyoblast apoptosis and in hypertensive rat heart with abdominal aorta ligation
Although IGF-II activating the IGF-II receptor signaling pathway has been found to stimulate cardiomyocyte hypertrophy, the role of IGF-II in cardiac cell apoptosis remains unclear. This study aimed to identify the roles of IGF-II and/or IGF-II receptors (IGF-II/IIR) in cardiomyoblast apoptosis and in hypertensive rat hearts with abdominal aorta ligation. Cultured rat heart-derived H9c2 cardiomyoblasts and excised hearts from Sprague-Dawley rats with 0- to 20-day complete abdominal aorta ligation, a model of ANG II elevation and hypertension, were used. IGF-II/IIR expression, caspase activity, DNA fragmentation, and apoptotic cells were measured by RT-PCR, Western blot, agarose gel electrophoresis, and TUNEL assay following various combinations of ANG II, IGF-II/IIR antibody, CsA (calcineurin inhibitor), SP-600125 (JNK inhibitor), SB-203580 (p38 inhibitor), U-0126 (MEK inhibitor), or Staurosporine (PKC inhibitor) in H9c2 cells. ANG II-induced DNA fragmentation and TUNEL-positive cells were blocked by IGF-II/IIR antibodies and antisense IGF-II, but not by IGF-II sense. IGF-II-induced apoptosis was blocked by IGF-IIR antibody and CsA. The increased gene expressions of IGF-II and -IIR induced by ANG II were reversed by U-0126 and Sp600125, respectively. Caspase 8 activities induced by ANG II were attenuated by U-0126, SP-600125, and CsA. DNA fragmentation induced by ANG II was totally blocked by SP-600125, and CsA and was attenuated by U-0126. In rats with 0- to 20-day complete abdominal aorta ligation, the increases in IGF-II/IIR levels in the left ventricle were accompanied by hypertension as well as increases in caspase 9 activities and TUNEL-positive cardiac myocytes. ANG II-induced apoptosis was reversed by IGF-II/IIR blockade and coexisted with increased transactivation of IGF-II and -IIR, which are mediated by ERK and JNK pathways, respectively, both of which further contributed to cardiomyoblast apoptosis via calcineurin signaling. The increased cardiac IGF-II, IGF-IIR, caspase 9, and cellular apoptosis were also found in hypertensive rats with abdominal aorta ligation
A fault identification and classification scheme for an automobile door assembly process
A process fault identification and classification scheme for an automobile door assembly process is presented based on multivariate in-line dimensional measurements and principal component factor analysis. First, the door assembly process and the dimensional measurement system are briefly introduced. Second, the technique of principal component factor analysis is presented for process fault identification. Process faults are summarized based on off-line identified case studies. Finally a machine classification scheme based on principal components and principal factors is presented and evaluated, using the pattern knowledge obtained off-line. This scheme is shown to be effective in classifying process faults using production data.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45569/1/10696_2005_Article_BF01324797.pd
Cardiomyoblast apoptosis induced by insulin-like growth factor (IGF)-I resistance is IGF-II dependent and synergistically enhanced by angiotensin II
Objective: This study explores the synergistic effect of cardiomyoblast apoptosis induced by angiotensin II (Ang II) and Insulin-like growth factor (IGF)-I resistance, and elucidates the role of IGF-II via IGF-II receptor (R) and calcineurin pathways in apoptosis induced by Ang II and IGF-I resistance. Methods: Apoptosis of cultured cardiomyoblast H9c2 cells was assessed by DNA fragmentation on agarose gel electrophoresis, nuclear condensation stained with DAPI, and Western blot analysis of pro-apoptotic Bad and cytochrome c in various combinations of control, Ang II, antisense IGF (I or II), IGF (I or II) antibody, IGF (I or II) receptor (R) antibody, or calcineurin inhibitor (Cyclosporine A, (CsA)). Results: We found the following: (I) The combination of Ang II and IGF-I deficiencies had a synergistic effect on apoptosis, confirmed by DNA fragmentation, nuclei condensation, and increases in such proapoptotic proteins as Bad, cytochrome c, caspase 9, and caspase 3 in H9c2 cells. (2) IGF-II and IGF-IIR protein products were increased by antisense IGF-I and IGF-I resistance, but these IGF-II protein products were not affected by sense IGF-I and non-specific antibody IgG in H9c2 cells. (3) The alteration of Bad protein level and the release of cytochrome c, both induced by treatments containing combinations of Ang II and antisense IGF-I, IGF-I antibody or IGF-IR antibody, were inhibited by IGF-II antibody. (4) DNA fragmentation, Bad, and cytochrome c which was induced by treatments combining IGF-IR antibody with Ang II or combining IGF-IR antibody with IGF-II were remarkably attenuated by CsA. Conclusion: IGF-I deficiency and/or IGF-IR resistance induced apoptosis in cardiomyoblast cells. The apoptosis, which might have been caused by the upregulation of IGF-II and IGF-IIR genes possibly activated the downstream calcineurin pathway, was synergistically augmented by Ang II
The profile of cardiac cytochrome c oxidase (COX) expression in an accelerated cardiac-hypertrophy model
The contribution of the mitochondrial components, the main source of energy for the cardiac hypertrophic growth induced by pressure overload, is not well understood. In the present study, complete coarctation of abdominal aorta was used to induce the rapid development of cardiac hypertrophy in rats. One to two days after surgery, we observed significantly higher blood pressure and cardiac hypertrophy, which remained constantly high afterwards. We found an early increased level of cytochrome c oxidase ( COX) mRNA determined by in-situ hybridization and dot blotting assays in the hypertrophied hearts, and a drop to the baseline 20 days after surgery. Similarly, mitochondrial COX protein level and enzyme activity increased and, however, dropped even lower than baseline 20 days following surgery. In addition, in natural hypertension- induced hypertrophic hearts in genetically hypertensive rats, the COX protein was significantly lower than in normotensive rats. Taken together, the lower efficiency of mitochondrial activity in the enlarged hearts of long-term complete coarcted rats or genetically hypertensive rats could be, at least partially, the cause of hypertensive cardiac disease. Additionally, the rapid complete coarctation-induced cardiac hypertrophy was accompanied by a disproportionate COX activity increase, which was suggested to maintain the cardiac energy-producing capacity in overloaded hearts
Correction to "Detection of Active Mammalian GH31 α-Glucosidases in Health and Disease Using In-Class, Broad-Spectrum Activity-Based Probes"
[This corrects the article DOI: 10.1021/acscentsci.6b00057.].Medical BiochemistryBio-organic Synthesi
Towards broad spectrum activity-based glycosidase probes: synthesis and evaluation of deoxygenated cyclophellitol aziridines
Bio-organic SynthesisMedical Biochemistr
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