Search results for "PK"

“Cysteinyl leukotriene-1 receptor activation in a human bronchial epithelial cell line leads to signal transducer and activator of transcription 1-me…

2008

Abstract We studied the effect of leukotriene D(4) (LTD(4)) on a human bronchial epithelial cell line (16HBE) overexpressing the cysteinyl leukotriene (CysLT) (1) receptor (HBECysLT(1)R), looking at the associated signal transduction mechanisms as well as at effects on inflammatory cell adhesion. The results obtained showed that LTD(4) increases the phosphorylation of extracellular signal-regulated protein kinase (ERK) 1/2 and of the signal transducer and activator of transcription 1 (STAT-1) in serine 727 (STAT-1Ser727), resulting in increased eosinophil adhesion to HBECysLT(1)R, associated with enhanced surface expression of intercellular adhesion molecule (ICAM) 1. Pretreatment with a Cy…

Inhibition of Mitochondrial Function by Efavirenz Increases Lipid Content in Hepatic Cells

2010

Efavirenz (EFV) is a non-nucleoside reverse transcriptase inhibitor (NNRTI) widely used in human immunodeficiency virus (HIV) infection therapy. It has been associated with hepatotoxic effects and alterations in lipid and body fat composition. Given the importance of the liver in lipid regulation, we have evaluated the effects of clinically used concentrations of EFV on the mitochondria and lipid metabolism of human hepatic cells in vitro. Mitochondrial function was rapidly undermined by EFV to an extent that varied with the concentration employed; in particular, respiration and intracellular adenosine triphosphate (ATP) levels were reduced whereas reactive oxygen species (ROS) production i…

A novel regulatory mechanism of MAP kinases activation and nuclear translocation mediated by PKA and the PTP-SL tyrosine phosphatase

1999

Protein tyrosine phosphatase PTP-SL retains mitogen-activated protein (MAP) kinases in the cytoplasm in an inactive form by association through a kinase interaction motif (KIM) and tyrosine dephosphorylation. The related tyrosine phosphatases PTP-SL and STEP were phosphorylated by the cAMP-dependent protein kinase A (PKA). The PKA phosphorylation site on PTP-SL was identified as the Ser231 residue, located within the KIM. Upon phosphorylation of Ser231, PTP-SL binding and tyrosine dephosphorylation of the MAP kinases extracellular signal–regulated kinase (ERK)1/2 and p38α were impaired. Furthermore, treatment of COS-7 cells with PKA activators, or overexpression of the Cα catalytic subunit …

Late activation of stress kinases (SAPK/JNK) by genotoxins requires the DNA repair proteins DNA-PKcs and CSB.

2005

Although genotoxic agents are powerful inducers of stress kinases (SAPK/JNK), the contribution of DNA damage itself to this response is unknown. Therefore, SAPK/JNK activation of cells harboring specific defects in DNA damage-recognition mechanisms was studied. Dual phosphorylation of SAPK/JNK by the genotoxin methyl methanesulfonate (MMS) occurred in two waves. The early response (≤2 h after exposure) was similar in cells knockout for ATM, PARP, p53, and CSB or defective in DNA-PKcscompared with wild-type cells. The late response however (≥4 h), was drastically reduced in DNA-PKcsand Cockayne's syndrome B (CSB)-deficient cells. Similar results were obtained with human cells lacking DNA-PKc…

How DNA lesions are turned into powerful killing structures: Insights from UV-induced apoptosis

2008

Mammalian cells treated with ultraviolet (UV) light provide one of the best-known experimental systems for depicting the biological consequences of DNA damage. UV irradiation induces the formation of DNA photoproducts, mainly cyclobutane pyrimidine dimers (CPDs) and (6-4) pyrimidine-pyrimidone photoproducts [(6-4)PPs], that drastically impairs DNA metabolism, culminating in the induction of cell death by apoptosis. While CPDs are the most important apoptosis-inducing lesions in DNA repair proficient cells, recent data indicates that (6-4)PPs also signals for apoptosis in DNA repair deficient cells. The toxic effects of these unrepaired DNA lesions are commonly associated with transcription …

Praktiskā piensaimniecība

1928

Saturs: I. Pienalopu izvēle, izkopšana un apkopšana. Piens, krējums un tā pārstrādāšana sviestā. II. Sierniecība. III. Piensaimniecības mašīnas.

Antioxidant and Anti-Inflammatory Potential of Polyphenols Contained in Mediterranean Diet in Obesity: Molecular Mechanisms

2021

Nutrition transition can be defined as shifts in food habits, and it is characterized by high-fat (chiefly saturated animal fat), hypercaloric and salty food consumption at the expense of dietary fibers, minerals and vitamins. Western dietary patterns serve as a model for studying the impact of nutrition transition on civilization diseases, such as obesity, which is commonly associated with oxidative stress and inflammation. In fact, reactive oxygen species (ROS) overproduction can be associated with nuclear factor-κB (NF-κB)-mediated inflammation in obesity. NF-κB regulates gene expression of several oxidant-responsive adipokines including tumor necrosis factor-α (TNF-α). Moreover, AMP-act…

Latvijas Universitātes Raksti; 765 .sēj.

2011

Masu apkalpošanas sistēmu tīklu izmantošana bankas darbībā

2019

Bakalaura darbā ir īss masu apkalpošanas teorijas apraksts un vēstures ieskats. Tiek aprakstītas masu apkalpošanas sistēmas un masu apkalpošanas tīkli. Darba mērķis ir izpētīt divus dažādus masu apkalpošanas tīklus – atvērto Džeksona tīklu un slēgto Gordona – Ņūela tīklu. Darba noslēgumā ir izstrādāti praktiski uzdevumi, kuros tiek izmantotas Džeksona un Gordona – Ņūela teorēmas.

Masu apkalpošanas sistēmu tīkli

2021

Šajā darbā tiek sniegts ieskats masu apkalpošanas sistēmu tīklu dažādos veidos, tiek dotas formulas tīklu darbības rādītāju noteikšanai un aprakstīti reizinājumu formas tīkli. Sīkāk tiek apskatīti trīs masu apkalpošanas sistēmas tīklu veidi - Džeksona tīkli, Gordona-Ņūela tīkli un BCMP tīkli. Katram veidam ir arī dots piemērs ar aprēķiniem. Ir arī piedāvāti uzdevumi patstāvīgai risināšanai.