Search results for "proliferation"
showing 10 items of 1193 documents
Progressive Endoplasmic Reticulum Stress Contributes to Hepatocarcinogenesis in Fatty Acyl-CoA Oxidase 1–Deficient Mice
2011
Fatty acyl-coenzyme A oxidase 1 (ACOX1) knockout (ACOX1(-/-)) mice manifest hepatic metabolic derangements that lead to the development of steatohepatitis, hepatocellular regeneration, spontaneous peroxisome proliferation, and hepatocellular carcinomas. Deficiency of ACOX1 results in unmetabolized substrates of this enzyme that function as biological ligands for peroxisome proliferator-activated receptor-α (PPARα) in liver. Here we demonstrate that sustained activation of PPARα in ACOX1(-/-) mouse liver by these ACOX1 substrates results in endoplasmic reticulum (ER) stress. Overexpression of transcriptional regulator p8 and its ER stress-related effectors such as the pseudokinase tribbles h…
Effects of Mancozeb and Metribuzin on in vitro proliferative responses and oxidative stress of human and rat spleen lymphocytes stimulated by mitogens
2011
Pesticides have been shown to possess marked immunotropic activity. The aim of this work was to study the in vitro effects of different concentrations (1-100 µM) of Mancozeb (fungicide) and Metribuzin (herbicide), on the proliferative responses of human and rat spleen lymphocytes stimulated by concanavalin A (ConA, mitogen), the Th1- (IL-2, INFγ) and Th2- (IL-4) cytokine secretion and on the intracellular oxidative status. The results showed that Mancozeb significantly reduced ConA lymphocyte proliferation in a dose-dependent manner in both humans and rats. It also decreased IL-2, INFγ and IL-4 secretion with a a shift away to Th1 phenotype. Metribuzin at low concentrations (1-10 µM) result…
Phosphodiesterase-4 inhibition improves corticosteroid insensitivity in pulmonary endothelial cells under oxidative stress.
2012
Several clinical studies have shown that smoking in asthmatics and chronic obstructive pulmonary disease patients is closely associated with corticosteroid refractoriness. In this work, we have analyzed glucocorticoid insensitivity in human pulmonary artery endothelial cells (HPAECs) under cigarette smoke extract (CSE) exposure as well as the possible additive effects of the combination therapy with a phosphodiesterase (PDE)-4 inhibitor. Interleukin (IL)-8 was measured in cell supernatants by ELISA. Histone deacetylase (HDAC), histone acetylase (HAT), and intracellular cAMP levels were measured by colorimetric assays and enzyme immunoassay, respectively. PDE4 isotypes and glucocorticoid rec…
Gastrin: an acid-releasing, proliferative and immunomodulatory peptide?
2010
Gastrin release is affected by gastric inflammatory conditions. Antral G cells respond to inflammatory mediators by increasing gastrin secretion. Accumulating experimental evidence suggests that gastrin exerts immunomodulatory and proinflammatory effects. Gastrin could be a contributing factor to these pathologies, which may constitute a new justification for pharmacological blockade of gastrin action.
The CB1 cannabinoid receptor mediates excitotoxicity-induced neural progenitor proliferation and neurogenesis.
2007
Endocannabinoids are lipid signaling mediators that exert an important neuromodulatory role and confer neuroprotection in several types of brain injury. Excitotoxicity and stroke can induce neural progenitor (NP) proliferation and differentiation as an attempt of neuroregeneration after damage. Here we investigated the mechanism of hippocampal progenitor cell engagement upon excitotoxicity induced by kainic acid administration and the putative involvement of the CB1 cannabinoid receptor in this process. Adult NPs express kainate receptors that mediate proliferation and neurosphere generation in vitro via CB1 cannabinoid receptors. Similarly, in vivo studies showed that excitotoxicity-induce…
An O2-sensitive glomus cell-stem cell synapse induces carotid body growth in chronic hypoxia.
2013
Summary Neural stem cells (NSCs) exist in germinal centers of the adult brain and in the carotid body (CB), an oxygen-sensing organ that grows under chronic hypoxemia. How stem cell lineage differentiation into mature glomus cells is coupled with changes in physiological demand is poorly understood. Here, we show that hypoxia does not affect CB NSC proliferation directly. Rather, mature glomus cells expressing endothelin-1, the O 2 -sensing elements in the CB that secrete neurotransmitters in response to hypoxia, establish abundant synaptic-like contacts with stem cells, which express endothelin receptors, and instruct their growth. Inhibition of glomus cell transmitter release or their sel…
Tetralogy of Fallot as a Model to Study Cardiac Progenitor Cell Migration and Differentiation During Heart Development
2009
Tetralogy of Fallot (ToF) has long been considered a congenital disorder that occurs due to environmental alterations during gestation. Recently, several mutated genes have been discovered that are thought to be responsible for the malformations observed in ToF. These genetic mutations, which are microdeletions, are sporadic and are frequently also present in trisomy 21 patients. The ToF malformations can be lethal, but for the last 50 years, surgical repairs that place an artificial patch to repair the four features of ToF have improved the survival of patients with ToF. However, 0.5% to 6% of patients who survive after surgical repair of ToF die of sudden cardiac death caused by ventricul…
Current perspectives on parathyroid hormone (PTH) and PTH-related protein (PTHrP) as bone anabolic therapies.
2013
Osteoporosis is characterized by low bone mineral density and/or poor bone microarchitecture leading to an increased risk of fractures. The skeletal alterations in osteoporosis are a consequence of a relative deficit of bone formation compared to bone resorption. Osteoporosis therapies have mostly relied on antiresorptive drugs. An alternative therapeutic approach for osteoporosis is currently available, based on the intermittent administration of parathyroid hormone (PTH). Bone anabolism caused by PTH therapy is mainly accounted for by the ability of PTH to increase osteoblastogenesis and osteoblast survival. PTH and PTH-related protein (PTHrP)-an abundant local factor in bone- interact wi…
Resistance of the internal mammary artery to restenosis: a histomorphologic study of various porcine arteries.
2007
<i>Background/Aims:</i> Restenosis after percutaneous transluminal angioplasty (PTA) of the internal mammary artery (IMA) grafts is much less pronounced than in other arteries and venous grafts. The aim of the study was to test whether various arteries respond differently to dilatation. <i>Methods:</i> PTA of the IMA, carotid, renal and circumflex coronary (RCx) arteries was performed in 9 pigs (balloon to artery ratio of 1:1.5). After 8 weeks, angiography was repeated and vessels prepared for histological analysis. Immunohistochemical staining was done to examine proliferative activity (Ki67) and to identify the vasa vasorum of the adventitia (F VIII-RA). <i>R…
Rectal bleeding and prolapse… not always benign diseases rather anal cancer. The importance of a correct decision making since primary care
2016
Rectal bleeding is very common in general population with a prevalence of 10-20 %. Primary care physicians have to stratify patients basing on urgency and on the colo-rectal cancer risk and to conduct a decision making for the correct management. We report a case of a 61-years-old woman, complaining rectal bleeding and an anal mass attended to their family doctor who does a visit but without a digital rectal examination and diagnosed a hemorrhoidal prolapse suggesting medical therapy. For the persistence of symptoms she comes to our service from emergency attention. Inspection and digital rectal examination revealed an anal mass. CT scan was performed showing a large anal mass involving hal…