Search results for "Chick Embryo"
showing 10 items of 65 documents
Simultaneous Boron Ion‐Channel/Growth Factor Receptor Activation for Enhanced Vascularization
2018
[EN] Boron ion is essential in metabolism and its concentration is regulated by ion-channel NaBC1. NaBC1 mutations cause corneal dystrophies such as Harboyan syndrome. Here we propose a 3D molecular model for NaBC1 and show that simultaneous stimulation of NaBC1 and vascular growth factor receptors (VEGFR) promote angiogenesis in vitro and in vivo with ultra-low concentrations of VEGF. We show Human Umbilical Vein Endothelial Cells (HUVEC) organization into tubular structures indicative of vascularization potential. Enhanced cell sprouting was found only in the presence of VEGF and boron, effect abrogated after blocking NaBC1. We demonstrate that stimulated NaBC1 promotes angiogenesis via P…
GDF11 exhibits tumor suppressive properties in hepatocellular carcinoma cells by restricting clonal expansion and invasion.
2019
Growth differentiation factor 11 (GDF11) has been characterized as a key regulator of differentiation in cells that retain stemness features, despite some controversies in age-related studies. GDF11 has been poorly investigated in cancer, particularly in those with stemness capacity, such as hepatocellular carcinoma (HCC), one of the most aggressive cancers worldwide. Here, we focused on investigating the effects of GDF11 in liver cancer cells. GDF11 treatment significantly reduced proliferation, colony and spheroid formation in HCC cell lines. Consistently, down-regulation of CDK6, cyclin D1, cyclin A, and concomitant upregulation of p27 was observed after 24 h of treatment. Interestingly,…
Morphological and biochemical effects of glucocorticoids in chick embryo hepatocytes during development
1988
Abstract The administration in ovo of hydrocortisone-21-phosphate caused, in chick embryo liver, a reduction of the number of hepatocytes which can be isolated from 1 mg dry weight of liver and a marked increase of their size. Moreover, the treatment diminished the incorporation of thymidine into acid-insoluble fraction in these cells whilst it augmented the content of protein, RNA, DNA and the level of thymidine kinase/cell. These effects were highest at 8–10 days, then declined with the age, disappearing after 18th day of incubation. Similar effects were obtained by injecting other glucocorticoids or ACTH. Combined treatment with metopirone abolished the effects found with ACTH, but did n…
Novel 3-Azaindolyl-4-arylmaleimides Exhibiting Potent Antiangiogenic Efficacy, Protein Kinase Inhibition, and Antiproliferative Activity
2012
Tumor growth and metastasis are highly associated with the overexpression of protein kinases (PKs) regulating cell growth, apoptosis resistance, and prolonged cell survival. This study describes novel azaindolyl-maleimides with significant inhibition of PKs, such as VEGFR, FLT-3, and GSK-3β which are related to carcinogenesis. Furthermore, these compounds exhibit high kinase selectivity and potent inhibition of angiogenesis and cell proliferation, offering versatile options in cancer treatment strategies.
A comparative biochemical, pharmacological and immunological study of Clostridium novyi alpha-toxin, C. difficile toxin B and C. sordellii lethal tox…
1991
The three clostridial cytotoxins, i.e. alpha-toxin of C. novyi (Tox alpha-nov), toxin B of C. difficile (ToxB-dif) and lethal toxin of C. sordellii (LT-sor) consist of single peptide chains of about 200,000 (Tox alpha-nov), 250,000 (LT-sor) and 275,000 (ToxB-dif) mol. wts. ToxB-dif and LT-sor but not Tox alpha-nov cross-reacted with rabbit polyclonal antibodies. Toxicity upon i.v. injection in mice was similar (LD50, 100 hr, 50-200 ng/kg) and was characterized by a slowly developing fluid loss into the interstitial space. When injected into the rat paw the toxins caused a delayed local edema lasting for days. In vitro the three toxins provoked a persistent retraction of endothelial cells cu…
Microwave effects on isolated chick embryo hearts.
1986
This study was designed to examine the effects of microwaves on the electric activity of hearts as a means of elucidating interactive mechanisms of nonionizing radiation with cardiac tissue. Experiments were performed on isolated hearts of 9-12-day-old chick embryos placed in small petri dishes. Oxygenated isotonic Ringer's solution at 37 degrees C permitted heart survival. Samples were irradiated at 2.45 GHz with a power density of 3 mW/cm2. The heart signal was detected with a glass micropipet inserted into the sinoatrial node and examined by means of a Berg-Fourier analyzer. Pulsed microwaves caused the locking of the heartbeat to the modulation frequency, whereas continuous wave irradia…
Effects of thrombin and of the phospholipase C inhibitor, D609, on the vascularity of the chick chorioallantoic membrane.
2000
Abstract Microvascular corrosion casting was used to assess the effects of thrombin and D609, a phospholipase C inhibitor, on the vascularity of the chick embryo chorioallantoic membrane (CAM). Discs containing vehicle, thrombin or D609 were placed on the CAM of fertilized white Leghorn eggs on Day 9 of gestation and vascularity was assessed on Day 11. Thrombin caused significant increases in the numbers (43%), diameters (5%) and lengths (17%), of both pre- and postcapillaries (first-order vessels by centripetal ordering). Conversely, D609 caused a decrease in the numbers (27%), lengths (12%) and diameters (8%) of first-order vessels. D609 decreased the total vascular volume of first- to th…
Matrix-mediated canal formation in primmorphs from the sponge Suberites domuncula involves the expression of a CD36 receptor-ligand system.
2004
Sponges (Porifera), represent the phylogenetically oldest metazoan phylum still extant today. Recently, molecular biological studies provided compelling evidence that these animals share basic receptor/ligand systems, especially those involved in bodyplan formation and in immune recognition, with the higher metazoan phyla. An in vitro cell/organ-like culture system, the primmorphs, has been established that consists of proliferating and differentiating cells, but no canals of the aquiferous system. We show that after the transfer of primmorphs from the demosponge Suberites domuncula to a homologous matrix (galectin), canal-like structures are formed in these 3D-cell aggregates. In parallel …
Ceramide Mediates Acute Oxygen Sensing in Vascular Tissues
2014
AbstractAims: A variety of vessels, such as resistance pulmonary arteries (PA) and fetoplacental arteries and the ductus arteriosus (DA) are specialized in sensing and responding to changes in oxygen tension. Despite opposite stimuli, normoxic DA contraction and hypoxic fetoplacental and PA vasoconstriction share some mechanistic features. Activation of neutral sphingomyelinase (nSMase) and subsequent ceramide production has been involved in hypoxic pulmonary vasoconstriction (HPV). Herein we aimed to study the possible role of nSMase-derived ceramide as a common factor in the acute oxygen-sensing function of specialized vascular tissues. Results: The nSMase inhibitor GW4869 and an anticera…