Search results for "type II"
showing 10 items of 607 documents
Centromeric heterochromatin and satellite DNA in the Chironomus plumosus species group
1994
Species of the Chironomus plumosus group display significant differences in their amount of centromeric heterochromatin. A tandem-repetitive satellite-like DNA has been isolated from C. plumosus. This DNA accounts for a major part of the centromeric heterochromatin. The DNA element has a Sau3AI restriction site ("Sau elements") and a monomer length of 165 or 166 bp. It is A-T rich (73%) and reveals a moderate DNA curvature, as shown by gel migration and computer analysis. The chromosomal localization and genomic organization of Sau elements were studied in 24 Chironomus species by in situ hybridization and (or) Southern analysis. The DNA is predominantly located in the centromeric regions …
Non-cross-linked porcine-based collagen I-III membranes do not require high vascularization rates for their integration within the implantation bed: …
2012
There are conflicting reports concerning the tissue reaction of small animals to porcine-based, non-cross-linked collagen I-III membranes/matrices for use in guided tissue/bone regeneration. The fast degradation of these membranes/matrices combined with transmembrane vascularization within 4 weeks has been observed in rats compared with the slow vascularization and continuous integration observed in mice. The aim of the present study was to analyze the tissue reaction to a porcine-based non-cross-linked collagen I-III membrane in mice. Using a subcutaneous implantation model, the membrane was implanted subcutaneously in mice for up to 60 days. The extent of scaffold vascularization, tissue …
Haem oxygenase-1 counteracts the effects of interleukin-1β on inflammatory and senescence markers in cartilage-subchondral bone explants from osteoar…
2011
IL (interleukin)-1β plays an important role in cartilage extracellular matrix degradation and bone resorption in OA (osteoarthritis) through the induction of degradative enzymes and pro-inflammatory mediators. In the present study, we have determined the consequences of HO-1 (haem oxygenase-1) induction on markers of inflammation and senescence in the functional unit cartilage–subchondral bone stimulated with IL-1β. Cartilage–subchondral bone specimens were obtained from the knees of osteoarthritic patients. Treatment with the HO-1 inducer CoPP (cobalt protoporphyrin IX) counteracted the stimulatory effects of IL-1β on IL-6, nitrite, PGE2 (prostaglandin E2), TGF (transforming growth factor)…
Influence of retinol on human chondrocytes in agarose culture
1992
Vitamin A and its congeners, collectively called retinoids, are known to have teratogenic potential and have induced craniofacial and limb malformations in numerous animal species. More importantly, retinoids are recognized as teratogenic to fetuses of pregnant women who have taken such preparations for dermatologic disorders. Information gathered from the study of animal models suggests that retinoids interfere with cartilage differentiation. If chondrogenesis in limb development is disturbed it may contribute to limb reductions and malformations. In vitro studies using various animal systems have shown that cartilage matrix macromolecules are altered to resemble those secreted by mesenchy…
Pharmacological prevention of eNOS uncoupling.
2013
Under physiological conditions, nitric oxide (NO) is produced in the vasculature mainly by the endothelial NO synthase (eNOS). This endothelium-derived NO is a protective molecule with antihypertensive, antithrombotic and anti-atherosclerotic properties. Cardiovascular risk factors such as hypertension, hypercholesterolemia, cigarette smoking and diabetes mellitus induce oxidative stress mostly by stimulation of the NADPH oxidase. Overproduction of reactive oxygen species leads to oxidation of tetrahydrobiopterin (BH4), the essential cofactor of eNOS. In BH4 deficiency, oxygen reduction uncouples from NO synthesis, thereby converting eNOS to a superoxide- producing enzyme. Consequently, NO …
Individual measurements and nested designs in aquaculture experiments: a simulation study
1998
Simple and nested models for analysis of variance (ANOVA) in aquaculture experiments were compared with the help of computer simulations. Simple models for analysing variables that are based on tank means, such as final weight and growth rate, were found to be sensitive to differences in the number of individual observations in each tank. In comparison to nested models that take into account individual measurements, the simple models were found to overestimate the F ratio and increase the risk of committing type I error, i.e., accepting a false alternative hypothesis. Further, nested models permit greater flexibility in experimental design, and allow more economical solutions within a given…
Matrix metalloproteinase-2 matrix metalloproteinase-9 and inducible nitric oxide synthase in oral leukoplakia: Immunohistochemistry and RT-PCR analys…
2008
Oral leukoplakia is the most common and potentially malignant disorder of the oral mucosa. The definition of leukoplakia given by the World Health Organization is "a white plaque that cannot be characterized either from a clinical or from a histopathological point of view", thus the diagnosis of leukoplakia is based on the exclusion of other lesions of the oral mucosa. We believe it is necessary to identify molecular and immunohistochemical parameters that can contribute to discriminating between the different leukoplakia clinical subtypes coded by the epidemiology. In the present work we show the preliminary results of this research project. We investigated the expression of matrix metallo…
Human umbilical cord expresses several vasoactive peptides involved in the local regulation of vascular tone: protein and gene expression of Orphanin…
2011
Full-term human umbilical cord contains three blood vessels: two arteries coiled around a vein and surrounded by Wharton’s jelly, a mucous tissue with few mesenchymal stromal cells and abundant extracellular matrix. Umbilical vessels lack innervations, thus endothelial cells must play a role in the control of blood flow. The aim of this study was to investigate in human umbilical cord the expression of five peptides that could be involved in the regulation of vascular tone: Orphanin FQ, Oxytocin, Atrial Natriuretic Peptide (ANP), endothelial Nitric Oxide Synthase (eNOS) and inducible Nitric Oxide Synthase (iNOS). The expression of these molecules in full-term human umbilical cord …
Immunohistochemical and Biomolecular Identification of Orphanin FQ, eNOS, Atrial natriuretic Factor and Oxytocin in Rat Seminal Vesicles
2009
In previous studies performed on rodents, we detected the presence of adreno-cholinergic and peptidergic innervation in seminal vesicles and other organs of the male genital system, such as prostate and ductus deferens, in which we also investigated the expression of NOS and NADPH-diaphorase. During the present project we focused our attention on the expression of some peptides involved in local control of smooth muscle relaxation, contractility, vasodilatation and control of blood flow in rat seminal vesicles. We investigated, through immunohistochemistry and RT-PCR, the presence of four peptides: orphanin, eNOS, ANF and oxytocin. Immunohistochemistry was used to detect the presence of the…
Age-related Diseases: Key Role of Insulin Resistance for the Association Between Type II Diabetes and Alzheimer’s Disease
2012
Background: Alzheimer’s disease (AD) and Type 2 diabetes mellitus (T2DM) present many relationships. Insulin resistance (IR) plays a key role in neuronal degeneration and death. Reduced energy makes neurons more sensible to oxidation causing mitochondrial damages. Moreover AD brain has lower insulin utilization, reduced expression of its receptors and of IGF 1 and 2, all necessary for neuronal survival and learning and memory processes. Hyperinsulinemia is correlated with increase of hyerphosphorilated tau-protein. SHIP2, a phosphatase, is an antagonist of PI3K. Since the PI3K plays a key role in the biological effects of insulin, its attenuation could be associated with IR in T2DM. Methods…