Search results for "TYR"
showing 10 items of 2017 documents
Redox reaction between amino‐(3,4‐dihydroxyphenyl)methyl phosphonic acid and dopaquinone is responsible for the apparent inhibitory effect on tyrosin…
2002
Amino‐(3,4‐dihydroxyphenyl)methyl phosphonic acid, the phosphonic analog of 3,4‐dihydroxyphenylglycine, had been previously reported as a potent inhibitor of tyrosinase. The mechanism of the apparent enzyme inhibition by this compound has now been established. Amino‐(3,4‐dihydroxyphenyl)methyl phosphonic acid turned out to be a substrate and was oxidized to o‐quinone, which evolved to a final product identified as 3,4‐dihydroxybenzaldehyde, the same as for 3,4‐dihydroxyphenylglycine. Monohydroxylated compounds (amino‐(3‐hydroxyphenyl)methyl phosphonic acid and amino‐(4‐hydroxyphenyl)methyl phosphonic acid) were not oxidized, neither was 4‐hydroxy‐l‐phenylglycine. However, the relatively hig…
RAB18 Loss Interferes With Lipid Droplet Catabolism and Provokes Autophagy Network Adaptations
2020
Autophagy is dependent on appropriate lipid supply for autophagosome formation. The regulation of lipid acquisition and the autophagy network response to lipid-limiting conditions are mostly elusive. Here, we show that the knockout of the RAB GTPase RAB18 interferes with lipid droplet catabolism, causing an impaired fatty acid release. The resulting reduced lipid-droplet-derived lipid availability influences autophagy and provokes adaptive modifications of the autophagy network. These adjustments include increased expression and phosphorylation of ATG2B as well as augmented formation of the ATG12-ATG5 conjugate. Moreover, ATG9A shows an enhanced phosphorylation at amino acid residues tyrosi…
Aplidin® induces JNK-dependent apoptosis in human breast cancer cells via alteration of glutathione homeostasis, Rac1 GTPase activation, and MKP-1 ph…
2006
Aplidin® is an antitumor agent in phase II clinical trials that induces apoptosis through the sustained activation of Jun N-terminal kinase (JNK). We report that Aplidin® alters glutathione homeostasis increasing the ratio of oxidized to reduced forms (GSSG/GSH). Aplidin® generates reactive oxygen species and disrupts the mitochondrial membrane potential. Exogenous GSH inhibits these effects and also JNK activation and cell death. We found two mechanisms by which Aplidin® activates JNK: rapid activation of Rac1 small GTPase and downregulation of MKP-1 phosphatase. Rac1 activation was diminished by GSH and enhanced by L-buthionine (SR)-sulfoximine, which inhibits GSH synthesis. Downregulatio…
Tiam1 as a Signaling Mediator of Nerve Growth Factor-Dependent Neurite Outgrowth
2010
Nerve Growth Factor (NGF)-induced neuronal differentiation requires the activation of members of the Rho family of small GTPases. However, the molecular mechanisms through which NGF regulates cytoskeletal changes and neurite outgrowth are not totally understood. In this work, we identify the Rac1-specific guanine exchange factor (GEF) Tiam1 as a novel mediator of NGF/TrkA-dependent neurite elongation. In particular, we report that knockdown of Tiam1 causes a significant reduction in Rac1 activity and neurite outgrowth induced by NGF. Physical interaction between Tiam1 and active Ras (Ras- GTP), but not tyrosine phosphorylation of Tiam1, plays a central role in Rac1 activation by NGF. In add…
On the modification of the nitrile groups of acrylonitrile/butadiene/styrene into oxazoline in the melt
2000
Oxazoline functionality is well known to be highly reactive toward a lot of other functional groups like carboxyls, hydroxyls, mercaptans, and amines. In this work we report the possibility to modify the nitrile groups of an acrylonitrile/butadiene/styrene (ABS) copolymer into oxazoline in the molten state in the presence of aminoethanol as modifier agent and zinc acetate as a catalyst. The reaction has been carried out in a batch mixer and in a corotating twin screw extruder. The conversion of the nitrile groups into oxazoline has been verified by infrared spectroscopy, NMR analysis microanalysis and confirmed by thermomechanical characterization. The results indicate that the kinetic of g…
Ruch pokojowy w RFN (Friedensbewegung) w pierwszej połowie lat osiemdziesiątych XX wieku
2017
W latach 80. XX wieku ruch pokojowy mobilizujący setki tysięcy osób w protestach przeciwko podwójnej uchwale NATO z grudnia 1979 r. był istotnym elementem zachodnioniemieckiej sceny politycznej. Wpływał na układ sił i konflikty wewnętrzne w socjaldemokracji niemieckiej (SPD), będąc największym oponentem polityki prowadzonej przez rząd kanclerza Helmuta Schmidta, przyczynił się do powstania Partii Zielonych, a jego działania doprowadziły do zaistnienia polemiki w związkach zawodowych i były bodźcem do dyskusji etycznych i religijnych w Kościele katolickim i protestanckim w RFN. Stał się również przedmiotem wielu kontrowersji oraz symbolem aktywności i siły społecznej.
Safety of Tyrosine Kinase Inhibitors in Patients With Differentiated Thyroid Cancer: Real-World Use of Lenvatinib and Sorafenib in Korea
2019
Background: Thyroid cancer has become the most common cancer in Korea. Generally, thyroid cancer patients have a good prognosis; however, 15–20% of patients experience recurrence or distant metastasis or are refractory to standard treatment. We assessed the safety of sorafenib and lenvatinib in patients with advanced or metastatic radioactive iodine-refractory differentiated thyroid cancers (DTC) consecutively treated at a tertiary center in South Korea.Methods: We retrospectively reviewed the charts of all consecutive patients with DTC treated during ≥6 months with lenvatinib (February 2016–April 2018) and sorafenib (January 2014–April 2018) at Gangnam Severance Hospital. Patients were tre…
New seismological and geological-structural contributions to the support of a seismotectonic model of the hinge area between northern Sicily and sout…
2012
Submarine Slope Failures Along the Northern Sicilian Continental Margin (Southern Tyrrhenian Sea) and Possible Implications for Geo-Hazard
2013
Mass wasting and downslope movements are common processes that have contributed to shape the northern Sicilian continental margin (southern Tyrrhenian Sea) since the Late Quaternary. Nevertheless, processes controlling their evolution are still partially unknown and a variety of geologic factors can be responsible for their formation. In this work we present an overview of the main mass wasting features (submarine canyons, landslides, debris flows) observed and mapped in different sectors of the northern Sicilian margin. The margin is characterized by a narrow, steep continental shelf (1-2°) and a very irregular and steep (6-8°) upper slope. The main aims of this work are: (1) to outline th…