Search results for "collage"
showing 10 items of 638 documents
Vitamin A deficiency alters rat lung alveolar basement membrane: reversibility by retinoic acid.
2010
Vitamin A is essential for lung development and pulmonary cell differentiation and its deficiency results in alterations of lung structure and function. Basement membranes (BMs) are also involved in those processes, and retinoic acid, the main biologically active form of vitamin A, influences the expression of extracellular matrix macromolecules. Therefore, we have analyzed the ultrastructure and collagen content of lung alveolar BM in growing rats deficient in vitamin A and the recovering effect of all-trans retinoic acid. Male weanling pups were fed a retinol-adequate or -deficient diet until they were 60 days old. A group of vitamin A-deficient pups were recovered by daily intraperitonea…
Vitamin A deficiency alters the structure and collagen IV composition of rat renal basement membranes.
2005
Retinoids can modulate the expression of extracellular matrix (ECM) proteins with variable results depending on other contributing factors. Because changes in these proteins may alter the composition and impair the function of specialized ECM structures such as basement membranes (BMs), we studied the effects of vitamin A deficiency on renal BMs during the growing period. Newborn male rats were fed a vitamin A-deficient (VAD) diet for 50 d. The ultrastructure of renal BMs was analyzed by electron microscopy. Total collagen IV, the different alpha(IV) chains, matrix degrading metalloproteinases (MMP), and tissue inhibitors of metalloproteinases (TIMP) were quantified by immunocytochemistry a…
Vitamin A Deficiency and Alterations in the Extracellular Matrix
2014
Vitamin A or retinol which is the natural precursor of several biologically active metabolites can be considered the most multifunctional vitamin in mammals. Its deficiency is currently, along with protein malnutrition, the most serious and common nutritional disorder worldwide. It is necessary for normal embryonic development and postnatal tissue homeostasis, and exerts important effects on cell proliferation, differentiation and apoptosis. These actions are produced mainly by regulating the expression of a variety of proteins through transcriptional and non-transcriptional mechanisms. Extracellular matrix proteins are among those whose synthesis is known to be modulated by vitamin A. Reti…
Effects of fabrication on the mechanics, microstructure and micromechanical environment of small intestinal submucosa scaffolds for vascular tissue e…
2013
In small intestinal submucosa scaffolds for functional tissue engineering, the impact of scaffold fabrication parameters on success rate may be related to the mechanotransductory properties of the final microstructural organization of collagen fibers. We hypothesized that two fabrication parameters, 1) preservation (P) or removal (R) of a dense collagen layer present in SIS and 2) SIS in a final dehydrated (D) or hydrated (H) state, have an effect on scaffold void area, microstructural anisotropy (fiber alignment) and mechanical anisotropy (global mechanical compliance). We further integrated our experimental measurements in a constitutive model to explore final effects on the micromechanic…
Optical quality comparison between 2 collagen copolymer posterior chamber phakic intraocular lens designs
2014
Purpose To compare the optical quality in vitro of 2 designs of the Visian Implantable Collamer Lens phakic intraocular lens (pIOL) for different powers and optical apertures. Setting University of Valencia, Valencia, Spain. Design Experimental study. Methods The Nimo TR1504 deflectometry device was used to measure the V4c pIOL, which has a smaller optic diameter, and the V5 pIOL, which has a larger optic diameter. The pIOLs were measured for −3.00 diopters (D), −6.00 D, −9.50 D, and −10.50 D at different optical apertures from 3.00 to 6.00 mm depending on the IOL power and model. The root mean square of higher-order aberrations (RMS HOAs) was analyzed. The Strehl ratio, point-spread functi…
Oleuropein multicompartment nanovesicles enriched with collagen as a natural strategy for the treatment of skin wounds connected with oxidative stres…
2021
Aim: Collagen-enriched transfersomes, glycerosomes and glytransfersomes were specifically tailored for skin delivery of oleuropein. Methods: Vesicles were prepared by direct sonication and their main physicochemical and technological properties were measured. Biocompatibility, protective effect and promotion of the healing of a wounded cell monolayer were tested in vitro using fibroblasts. Results: Vesicles were mainly multicompartment, small (∼108 nm), slightly polydispersed (approximately 0.27) and negatively charged (~-49 mV). Oleuropein was incorporated in high amounts (approximately 87%) and vesicles were stable during four months of storage. In vitro studies confirmed the low toxicit…
A Neandertal dietary conundrum: Insights provided by tooth enamel Zn isotopes from Gabasa, Spain
2022
The characterization of Neandertals’ diets has mostly relied on nitrogen isotope analyses of bone and tooth collagen. However, few nitrogen isotope data have been recovered from bones or teeth from Iberia due to poor collagen preservation at Paleolithic sites in the region. Zinc isotopes have been shown to be a reliable method for reconstructing trophic levels in the absence of organic matter preservation. Here, we present the results of zinc (Zn), strontium (Sr), carbon (C), and oxygen (O) isotope and trace element ratio analysis measured in dental enamel on a Pleistocene food web in Gabasa, Spain, to characterize the diet and ecology of a Middle Paleolithic Neandertal individual. Based on…
Zinc isotopes in Late Pleistocene fossil teeth from a Southeast Asian cave setting preserve paleodietary information
2020
Significance Dietary habits, especially meat consumption, represent a key aspect in the behavior and evolution of fossil hominin species. Here, we explore zinc (Zn) isotope ratios in tooth enamel of fossil mammals. We show discrimination between different trophic levels and demonstrate that Zn isotopes could prove useful in paleodietary studies of fossil hominin, or other mammalian species, to assess their consumption of animal versus plant resources. We also demonstrate the high preservation potential of pristine diet-related Zn isotope ratios, even under tropical conditions with poor collagen preservation, such as the studied depositional context in Southeast Asia. However, assessing the …
Effect of dual blockade of renin-angiotensin system on TGF beta 1 and left ventricular structure and function in hypertensive patients
2007
The effects of 24 weeks losartan and ramipril treatment,both alone and in combination, on left ventricular mass (LVM), circulating transforming growth factor b1(TGFb1), procollagen type I (PIP) and III (PIIIP), havebeen evaluated in hypertensive (HT) patients. A total of 57 HT with stage 1 and 2 essential hypertension were included. After 4 weeks run in, a randomized double blind, three arms, double dummy, independent trial was used. All HT patients were randomly allocated to three treatment arms consisting of losartan (50 mg/daily),ramipril (5 mg/ daily) and combined (losartan 50 mg/daily plus ramipril 5 mg/daily) for 24 weeks. TGFb1, PIP and PIIIP, LVM, LVM/h 2.7 and other echocardiograph…
Procollagen C-proteinase Enhancer Stimulates Procollagen Processing by Binding to the C-propeptide Region Only*
2011
Background: Procollagen C-proteinase enhancer-1 (PCPE-1) is an extracellular glycoprotein that increases activity of certain zinc metalloproteinases involved in tissue development and repair. Results: PCPE-1 binds uniquely to the C-propeptide region of the procollagen molecule. Conclusion: PCPE-1 enhances proteolysis by binding solely to the procollagen C-propeptides. Significance: These data may lead to future applications in the development of antifibrotic therapies.