20 research outputs found
In operando monitoring of the state of charge and species distribution in zinc air batteries using X-ray tomography and model-based simulations
Оптимизация условий экстрагирования меланинов из лузги подсолнечника
Определены оптимальные значения параметров экстрагирования меланинов из лузги подсолнечника: частота вибраций 24 Гц, концентрация раствора гидроксида натрия 0,36 М, 3 ступени экстрагирования, продолжительность экстрагирования на каждой ступени 20 минут. Выход меланинов при данных условиях составил 13,09%. Полученные данные могут быть использованы при разработке технологии получения меланина из альтернативного сырья - лузги подсолнечника.Defined are the optimal values of the parameters extraction of melanin from the husks of sunflower: the vibration frequency 24 Hz, the concentration of sodium hydroxide solution 0,36 M, 3 stages of extraction, duration of extraction at each stage in 20 minutes. The degree of extraction of melanin under these conditions were 13,09%. The results obtained determine the possibility of development of technology for production melanines from alternative raw materials - sunflower husk
Novel insights into PORCN mutations, associated phenotypes and pathophysiological aspects.
BACKGROUND: Goltz syndrome (GS) is a X-linked disorder defined by defects of mesodermal- and ectodermal-derived structures and caused by PORCN mutations. Features include striated skin-pigmentation, ocular and skeletal malformations and supernumerary or hypoplastic nipples. Generally, GS is associated with in utero lethality in males and most of the reported male patients show mosaicism (only three non-mosaic surviving males have been described so far). Also, precise descriptions of neurological deficits in GS are rare and less severe phenotypes might not only be caused by mosaicism but also by less pathogenic mutations suggesting the need of a molecular genetics and functional work-up of these rare variants. RESULTS: We report two cases: one girl suffering from typical skin and skeletal abnormalities, developmental delay, microcephaly, thin corpus callosum, periventricular gliosis and drug-resistant epilepsy caused by a PORCN nonsense-mutation (c.283C > T, p.Arg95Ter). Presence of these combined neurological features indicates that CNS-vulnerability might be a guiding symptom in the diagnosis of GS patients. The other patient is a boy with a supernumerary nipple and skeletal anomalies but also, developmental delay, microcephaly, cerebral atrophy with delayed myelination and drug-resistant epilepsy as predominant features. Skin abnormalities were not observed. Genotyping revealed a novel PORCN missense-mutation (c.847G > C, p.Asp283His) absent in the Genome Aggregation Database (gnomAD) but also identified in his asymptomatic mother. Given that non-random X-chromosome inactivation was excluded in the mother, fibroblasts of the index had been analyzed for PORCN protein-abundance and -distribution, vulnerability against additional ER-stress burden as well as for protein secretion revealing changes. CONCLUSIONS: Our combined findings may suggest incomplete penetrance for the p.Asp283His variant and provide novel insights into the molecular etiology of GS by adding impaired ER-function and altered protein secretion to the list of pathophysiological processes resulting in the clinical manifestation of GS
Recommended from our members
Novel insights into PORCN mutations, associated phenotypes and pathophysiological aspects.
BACKGROUND: Goltz syndrome (GS) is a X-linked disorder defined by defects of mesodermal- and ectodermal-derived structures and caused by PORCN mutations. Features include striated skin-pigmentation, ocular and skeletal malformations and supernumerary or hypoplastic nipples. Generally, GS is associated with in utero lethality in males and most of the reported male patients show mosaicism (only three non-mosaic surviving males have been described so far). Also, precise descriptions of neurological deficits in GS are rare and less severe phenotypes might not only be caused by mosaicism but also by less pathogenic mutations suggesting the need of a molecular genetics and functional work-up of these rare variants. RESULTS: We report two cases: one girl suffering from typical skin and skeletal abnormalities, developmental delay, microcephaly, thin corpus callosum, periventricular gliosis and drug-resistant epilepsy caused by a PORCN nonsense-mutation (c.283C > T, p.Arg95Ter). Presence of these combined neurological features indicates that CNS-vulnerability might be a guiding symptom in the diagnosis of GS patients. The other patient is a boy with a supernumerary nipple and skeletal anomalies but also, developmental delay, microcephaly, cerebral atrophy with delayed myelination and drug-resistant epilepsy as predominant features. Skin abnormalities were not observed. Genotyping revealed a novel PORCN missense-mutation (c.847G > C, p.Asp283His) absent in the Genome Aggregation Database (gnomAD) but also identified in his asymptomatic mother. Given that non-random X-chromosome inactivation was excluded in the mother, fibroblasts of the index had been analyzed for PORCN protein-abundance and -distribution, vulnerability against additional ER-stress burden as well as for protein secretion revealing changes. CONCLUSIONS: Our combined findings may suggest incomplete penetrance for the p.Asp283His variant and provide novel insights into the molecular etiology of GS by adding impaired ER-function and altered protein secretion to the list of pathophysiological processes resulting in the clinical manifestation of GS
Modeling ERBB receptor-regulated G1/S transition to find novel targets for de novo trastuzumab resistance
Different Regulation of the Formation of Intra- and Extracellular Oxygen Radicals in Macrophages
Analyzing transport paths in the air electrode of a zinc air battery using X-ray tomography
X-ray tomography was used to investigate the discharge behavior of a zinc air battery in-operando. A special battery set-up and preparation was used in order to meet both electrochemical and tomographic requirements. The prepared battery was discharged galvanostatically and analyzed with tomographic measurements at a state of charge of 100%, 75% and 65%. End-of-life of the investigated zinc air battery is reached much earlier than the amount of active zinc particles would allow. This is attributed to an observable blockage of oxygen transport paths in the gas diffusion layer caused by increased flooding with liquid. Keywords: Zinc air battery, X-ray tomography, Imaging, Gas diffusion layer, Transport paths, Air electrod
Intervening in β-Catenin Signaling by Sulindac Inhibits S100A4-Dependent Colon Cancer Metastasis12
Colon cancer metastasis is often associated with activation of the Wnt/β-catenin signaling pathway and high expression of the metastasis mediator S100A4. We previously demonstrated the transcriptional regulation of S100A4 by β-catenin and the importance of the interconnection of these cellular programs for metastasis. Here we probe the hypothesis that the nonsteroidal anti-inflammatory drug sulindac sulfide can inhibit colon cancer metastasis by intervening in β-catenin signaling and thereby interdicting S100A4. We treated colon cancer cell lines heterozygous for gain-of-function and wild-type β-catenin with sulindac. We analyzed sulindac's effects on β-catenin expression and subcellular localization, β-catenin binding to the T-cell factor (TCF)/S100A4 promoter complex, S100A4 promoter activity, S100A4 expression, cell motility, and proliferation. Mice intrasplenically transplanted with S100A4-overexpressing colon cancer cells were treated with sulindac. Tumor growth and metastasis, and their β-catenin and S100A4 expressions, were determined. We report the expression knockdown of β-catenin by sulindac, leading to its reduced nuclear accumulation. The binding of β-catenin to TCF was clearly lowered, resulting in reduced S100A4 promoter activity and expression. This correlated well with the inhibition of cell migration and invasion, which could be rescued by ectopic S100A4 expression. In mice, sulindac treatment resulted in reduced tumor growth in the spleen (P = .014) and decreased liver metastasis in a human colon cancer xenograft model (P = .025). Splenic tumors and liver metastases of sulindac-treated mice showed lowered β-catenin and S100A4 levels. These results suggest that modulators of β-catenin signaling such as sulindac offer potential as antimetastatic agents by interdicting S100A4 expression
Activation of 3-nitrobenzanthrone and its metabolites by human acetyltransferases, sulfotransferases and cytochrome P450 expressed in Chinese hamster V79 cells
"Activation of 3-nitrobenzanthrone and its metabolites by human acetyltransferases sulfotransferases and cytochrome P450 expressed in chinese hamster V79 cells. 3-Nitrobenzanthrone (3-NBA) is a potent mutagen and suspected human carcinogen identified in diesel exhaust and ambient air pollution. 3-Aminobenzanthrone (3-ABA) 3-acetylaminobenzanthrone (3-Ac-ABA) and N-acetyl-N-hydroxy-3-aminobenzanthrone (N-Ac-N-OH-ABA) have been identified as 3-NBA metabolites. Recently we found that 3-NBA and its metabolites (3-ABA 3-Ac-ABA and N-Ac-N-OH-ABA) form the same DNA adducts in vivo in rats. In order to investigate whether human cytochrome P450 (CYP) enzymes (i.e. CYP1A2) human NO-acetyltransferases (NATs) and sulfotransferases (SULTs) contribute to the metabolic activation of 3-NBA and its metabolites we developed a panel of Chinese hamster V79MZ-h1A2 derived cell lines expressing human CYP1A2 in conjunction with human NAT1 NAT2 SULT1A1 or SULT1A2 respectively. Cells were treated with 0.01 0.1 or 1 M 3-NBA or its metabolites (3-ABA 3-Ac-ABA and N-Ac-N-OH-ABA). Using both enrichment versions of the 32P-postlabeling assay nuclease P1 digestion and butanol extraction essentially 4 major and 2 minor DNA adducts were detected in the appropriate cell lines with all 4 compounds. The major ones were identical to those detected in rat tissue; the adducts lack an N-acetyl group. Human CYP1A2 was required for the metabolic activation of 3-ABA and 3-Ac-ABA (probably via N-oxidation) and enhanced the activity of 3-NBA (probably via nitroreduction). The lack of acetylated adducts suggests N-deacetylation of 3-Ac-ABA and N-Ac-N-OH-ABA. Thus N-hydroxy-3-aminobenzanthrone (N-OH-ABA) appears to be a common intermediate for the formation of the electrophilic arylnitrenium ions capable of reacting with DNA. Human NAT1 and NAT2 as well as human SULT1A1 and SULT1A2 strongly contributed to the high genotoxicity of 3-NBA and its metabolites. Moreover NO-acetyltransfer reactions catalyzed by human NATs leading to the corresponding N-acetoxyester may be important in the bioactivation of N-Ac-N-OH-ABA. As human exposure to 3-NBA is likely to occur primarily via the respiratory tract expression of CYPs NATs and SULTs in respiratory tissues may contribute significantly and specifically to the metabolic activation of 3-NBA and its metabolites. Consequently polymorphisms in these genes could be important determinants of lung cancer risk from 3-NBA. © 2003 Wiley-Liss Inc.