140 research outputs found

    Preliminary study on the use of the 137 Cs method for soil erosion investigation in the pampean region of Argentina

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    Soil erosion is the most important degradation process in A rgentine. According to the estimation of 4.9 millon ha in Pampa Ondulada Region, 1.600.000 ha (36% of agricultural soils) are affected by the erosion. Field measurements of soil erosion and sediment deposition using classical techniques are difficult, time consuming, and expensive but indispensable to feed the prediction models for conservation practices design and fa rm planning. Many authors have reported that the measurement of fallout nuclides is useful tool to characterize geomorphical processes. Walling and He proposes models for conve rting 137Cs depletion/enrichment amounts to net soil loss/deposition. These models are based in the comparison between a reference 137Cs profile in a long term undisturbed site (control site) and the 137Cs profiles in the suspected eroded or deposited sites in the landscape. The aim of this study is to provide a complete and well representative set of data on the erosion intensity in topographical conditions for the Pampa Ondulada Region in A rgentine by using a tracer technique. The study area is a small watershed (about 300 ha), located in Arroyo del Tala medium basin, within Partido of San Pedro in Buenos Aires Province, Argentine. This paper presents a group of results from a detailed investigation of erosion and sediment delivery, within a 49 ha cultivated field study site in this watershed. The base of sampling strategy is the grid approach. A reference inventory, representing the local fallout input, was searched for at a site experiencing neither erosion nor deposition. Radiocaesium analyses were made at the Nuclear Regulatory Authority Laboratory by a GE Hp detector. To make an interpretation of 137Cs distribution of soil losses and sedimentation, the Mass Balance Model 2 was used (Walling and He 1997). The erosion/deposition rates from Mass Balance Model 2 are in the range of 0 to -30 t·ha-1·y-1 for erosion, and 0 to 19 t·ha-1·y-1 for deposition, and these values matched well, with the rates of erosion obtained by classical methods. The 137Cs spatial and depth distribution are showed in a map, and enabled to study the relationship of the erosion to the topography, and a good discrimination in subclasses within moderate erosion class and sedimentation class

    Study of biochemical substrate and role of metalloproteinases in fascia transversalis from hernial processes

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    The aim of this study was to examine the fascia transversalis (FT) from patients with direct and indirect hernia in an attempt to identify possible differences between each type of hernia. FT samples were obtained from 36 patients presenting inguinal hernia (23 indirect hernia and 13 direct hernia) who underwent surgery. We have analysed the ultrastructure of the fascia surrounding the hernial lesions, the proline and lysine hydroxylation in the tissue, the type I-type III collagen ratio and the presence of metalloproteinases. We have not detected ultrastructural differences in the collagen fibrils from FT in direct and indirect hernias. However, the interfibrillar matrix was more abundant in direct hernias, showing abundant electron-dense particles. No differences in proline hydroxylation were observed between each type of hernia. A small decrease in lysine hydroxylation was detected in patients with direct hernia. Enzyme-linked immunosorbent assays (ELISAs) showed no statistically significant differences in the type I-type III collagen absorbance ratios. Immunohistochemistry revealed no differences in the expression of matrix metalloproteinase-1. FT from patients presenting direct hernia showed a very strong staining vs. metalloproteinase-2 when compared with that observed in indirect hernia

    Rapid thawing increases the fragility of the cryopreserved arterial wall

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    To extend present knowledge of the biomechanical and structural changes which occur in the cryopreserved, rapidly thawed arterial wall. Minipig iliac arterial segments were cryopreserved at -196 degrees C in either minimum essential medium or Wisconsin solution. Fresh segments served as the control group. After 1 month, the specimens were rapidly thawed (37 degrees C) and processed for biomechanical, ultrastructural, morphological and immunohistochemical (MMP-1, MMP-2, MMP-3 and MMP-9) analysis. Visualisation of apoptotic cells was performed by TUNEL method. For the mechanical distension analysis, an in vitro circuit was designed. The cryopreserved segments showed a 42% incidence of spontaneous fracture and the appearance of microfractures which affected the endoluminal third of the vessel. An accumulation of liquid in the subelastica was observed. An increased expression of wall-degradative enzymes (mainly MMP-2) was also observed following cryopreservation. No significant differences were detected in the proportional elasticity module or tensile strength of the specimen groups. No differences in mechanical distension were observed between groups after the vessel segments were subjected to the pulsatile circuit flow for 72 h. Cell damage was most intense in the specimens cryopreserved in Wisconsin solution. Cryopreservation in both the solutions employed, followed by rapid thawing, induce changes in the permeability which increase the fragility of the cryopreserved arterial wall. Both increased expression of wall-degradative enzymes and accumulation of liquid may contribute to graft failure after implantation

    Evaluation of the smooth muscle cell component and apoptosis in the varicose vein wall

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    This study was designed to evaluate the role of the smooth muscle cell and the apoptosis in the pathogenesis of the varicose vein. Segments of saphenous vein were obtained from healthy subjects and from those with varicose veins. The vein specimens were subdivided according to subject age (younger or older than 50 years) and according to the varicose vein source (distal or proximal). Morphological, ultrastructural, cell proliferation (anti-PCNA method) and cell death (TUNEL method) analysis were performed. The walls of healthy, control vein specimens acquired a more collagenous and papillomatous appearance with age. A slight increase in the number of TUNEL-positive cells was also observed in specimens from older subjects. The proportion of apoptotic cells was much greater in the varicose veins than in control specimens. Most cellular alterations were seen in proximal varicose segments obtained from young subjects. These specimens showed hypertrophic areas with a high degree of cellularity (both in the media and in the thickened intima). The highest proportion of apoptotic cells and collagenisation were also observed in these areas. The enhanced number of apoptotic cells in varicose veins observed mainly in proximal/young vein specimens could be responsible, at least in part, for the acceleration of the final fibrosclerotic process characteristic of the varicose vein wall

    Histopathological study of JNK in venous wall of patients with chronic venous insufficiency related to osteogenesis process

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    Chronic venous insufficiency (CVI) is one of the most common vascular pathologies worldwide. One of the risk factors for the development of CVI is aging, which is why it is related to senile changes. The main trigger of the changes that occur in the venous walls in CVI is blood flow reflux, which produces increased hydrostatic pressure, leading to valve incompetence. The cellular response is one of the fundamental processes in vascular diseases, causing the activation of cell signalling pathways such as c-Jun N-terminal kinase (JNK). Metabolic changes and calcifications occur in vascular pathology as a result of pathophysiological processes. The aim of this study was to determine the expression of JNK in venous disease and its relationship with the role played by the molecules involved in the osteogenic processes in venous tissue calcification. This was a cross-sectional study that analyzed the greater saphenous vein wall in 110 patients with (R) and without venous reflux (NR), classified according to age. Histopathological techniques were used and protein expression was analysed using immunohistochemistry techniques for JNK and markers of osteogenesis (RUNX2, osteocalcin (OCN), osteopontin (OPN)). Significantly increased JNK, RUNX2, OCN, OPN and pigment epithelium-derived factor (PEDF) protein expression and the presence of osseous metaplasia and amorphous calcification were observed in younger patients (<50 years) with venous reflux. This study shows for the first time the existence of an osteogenesis process related to the expression of JNK in the venous wall.This study (FIS-PI18/00912) was supported by the Instituto de Salud Carlos III (Plan Estatal de I+D+i 2013-2016) and cofinanced by the European Development Regional Fund ‘‘A way to achieve Europe’’ (ERDF) and B2017/BMD-3804 MITIC-C

    Women with psychotic episodes during pregnancy show increased markers of placental damage with Tenney-Parker changes

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    y. Psychosis is a hazardous and functionally disruptive psychiatric condition which may affect women in pregnancy, entailing negative consequences for maternofetal well-being. The precise pathophysiological basis and consequences of a psychotic episode in pregnancy remain to be further elucidated. The placenta is a pivotal tissue with many functions in the gestational period, critically influencing the fate and development of pregnancy. Although detrimental alterations have been observed in women undergoing severe psychiatric disorders in pregnancy, there are little studies evaluating the consequences of suffering from a psychotic episode in the placental tissue In this work, we have evaluated the histopathological consequences of a first episode of psychosis in pregnancy (FE-PW; N=22) and compare them with healthy pregnant women (HC-PW; N=20) by using histological, immunohistochemical and gene expression techniques. Our results define that the placental tissue of FE-PW display an increase in the number of placental villi, bridges, syncytial knots and syncytial knots/villi. Besides, we have also observed an enhanced gene and protein expression in FE-PW of the hypoxic marker HIF-1α, together with the apoptotic markers BAX and Bcl-2. To our knowledge, this is the first study demonstrating significant histopathological changes in the placenta of women suffering a new-onset psychotic episode in pregnancy. Further studies should be aimed at deepening the knowledge about the pernicious effects of psychosis in the maternofetal tissues, as well as the potential implications of these alterations

    Cambios en propiedades físicas y químicas del suelo bajo cultivo de Alelí Mathiola incana post-aplicación de dos fuentes de nutrientes

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    En Argentina, el Alelí (Mathiola incana) es muy frecuentemente cultivado por su uso ornamental. La principal zona productora del país se sitúa en el partido de La Plata. En estos sistemas intensivos, es común el uso de enmiendas orgánicas para el suelo. La enmienda orgánica más generalizada en las producciones horti-florícolas del partido de La Plata es la cama de pollo en reemplazo o como complemento de la fertilización química. La respuesta del suelo al agregado de enmiendas orgánicas es variable dependiendo del cultivo, el suelo, el clima, el manejo y el material utilizado. Habitualmente no se analizan las características de la cama de pollo ni los efectos que la misma tiene sobre las propiedades del suelo. Por otro lado, la fertilización química suele hacerse sin tener en cuenta los nutrientes disponibles del suelo, sin análisis previo. En este sentido, el objetivo de este trabajo fue analizar el impacto de diferentes fuentes de nutrientes sobre algunas propiedades físicas y químicas de un suelo en producción de Alelí. Se emplearon dos tratamientos: fertilización o (CP) y un testigo (T). Se determinó en el suelo: Densidad aparente (Dap), Potencial Hidrógeno (pH), Conductividad Eléctrica (CE) y Carbono Orgánico Total (COT) entre 0-10 cm de profundidad. Los resultados mostraron que una sola aplicación de cama de pollo como enmienda orgánica en un cultivo de Alelí generó una disminución de la Dap y un ligero incremento en la CE del suelo que podría convertirse en un riesgo en una producción continuada. Por otro lado, las parcelas tratadas con fertilizante químico mostraron una disminución del pH en el suelo.Fil: Sokolowski, Ana Clara. Universidad Nacional de Lomas de Zamora. Facultad de Ciencias Agrarias; ArgentinaFil: Paladino, Ileana Ruth. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Suelos; Argentina. Universidad Nacional de Lomas de Zamora. Facultad de Ciencias Agrarias; ArgentinaFil: Barrios, Mónica Beatriz. Universidad Nacional de Lomas de Zamora. Facultad de Ciencias Agrarias; ArgentinaFil: Prack Mc Cormick, B.P. Universidad Nacional de Lomas de Zamora. Facultad de Ciencias Agrarias; ArgentinaFil: De Grazia, Javier. Universidad Nacional de Lomas de Zamora. Facultad de Ciencias Agrarias; ArgentinaFil: Wolski José Enrique. Universidad Nacional de Lomas de Zamora. Facultad de Ciencias Agrarias; ArgentinaFil: Rodríguez, Hernán A. Universidad Nacional de Lomas de Zamora. Facultad de Ciencias Agrarias; ArgentinaFil: Debelis, Silvina. Universidad Nacional de Lomas de Zamora. Facultad de Ciencias Agrarias; ArgentinaFil: Rodríguez Frers, E.P. Universidad Nacional de Lomas de Zamora. Facultad de Ciencias Agrarias; ArgentinaFil: Buján, Alfonso. Universidad Nacional de Lomas de Zamora. Facultad de Ciencias Agrarias; Argentin

    3D silicon doped hydroxyapatite scaffolds decorated with Elastin-like Recombinamers for bone regenerative medicine

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    The current study reports on the manufacturing by rapid prototyping technique of three-dimensional (3D) scaffolds based on silicon substituted hydroxyapatite with Elastin-like Recombinamers (ELRs) functionalized surfaces. Silicon doped hydroxyapatite (Si-HA), with Ca-10(PO4)(5.7)(SiO4)(0.3)(OH)(1.7)h(0.3) nominal formula, was surface functionalized with two different types of polymers designed by genetic engineering: ELR-RGD that contain cell attachment specific sequences and ELR-SNA15/RGD with both hydroxyapatite and cells domains that interact with the inorganic phase and with the cells, respectively. These hybrid materials were subjected to in vitro assays in order to clarify if the ELRs coating improved the well-known biocompatible and bone regeneration properties of calcium phosphates materials. The in vitro tests showed that there was a total and homogeneous colonization of the 3D scaffolds by Bone marrow Mesenchymal Stromal Cells (BMSCs). In addition, the BMSCs were viable and able to proliferate and differentiate into osteoblasts. Statement of Significance Bone tissue engineering is an area of increasing interest because its main applications are directly related to the rising life expectancy of the population, which promotes higher rates of several bone pathologies, so innovative strategies are needed for bone tissue regeneration therapies. Here we use the rapid prototyping technology to allow moulding ceramic 3D scaffolds and we use different bio-polymers for the functionalization of their surfaces in order to enhance the biological response. Combining the ceramic material (silicon doped hydroxyapatite, Si-HA) and the Elastin like Recombinamers (ELRs) polymers with the presence of the integrin-mediate adhesion domain alone or in combination with SNAI 5 peptide that possess high affinity for hydroxyapatite, provided an improved Bone marrow Mesenchymal Stromal Cells (BMSCs) differentiation into osteoblastic linkage. (C) 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved

    H3K4me1 marks DNA regions hypomethylated during aging in human stem and differentiated cells

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    In differentiated cells, aging is associated with hypermethylation of DNA regions enriched in repressive histone post-translational modifications. However, the chromatin marks associated with changes in DNA methylation in adult stem cells during lifetime are still largely unknown. Here, DNA methylation profiling of mesenchymal stem cells (MSCs) obtained from individuals aged 2 to 92 yr identified 18,735 hypermethylated and 45,407 hypomethylated CpG sites associated with aging. As in differentiated cells, hypermethylated sequences were enriched in chromatin repressive marks. Most importantly, hypomethylated CpG sites were strongly enriched in the active chromatin mark H3K4me1 in stem and differentiated cells, suggesting this is a cell type-independent chromatin signature of DNA hypomethylation during aging. Analysis of scedasticity showed that interindividual variability of DNA methylation increased during aging in MSCs and differentiated cells, providing a new avenue for the identification of DNA methylation changes over time. DNA methylation profiling of genetically identical individuals showed that both the tendency of DNA methylation changes and scedasticity depended on nongenetic as well as genetic factors. Our results indicate that the dynamics of DNA methylation during aging depend on a complex mixture of factors that include the DNA sequence, cell type, and chromatin context involved and that, depending on the locus, the changes can be modulated by genetic and/or external factors

    Pelvic Floor Morbidity Following Vaginal Delivery versus Cesarean Delivery: Systematic Review and Meta-Analysis

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    Objective: To compare pelvic floor disorders between vaginal delivery (VD) and cesarean delivery (CD). Methods: For this study, a PUBMED database search was used, utilizing a combination of relevant medical subjects’ headings (MeSH) terms, with the following keywords: “Pelvic floor disorders” or “Pelvic floor morbidity” and “Delivery”. Search limits were articles in English or Spanish, about women, published from December 2009 to December 2019. The STATA 16 package was used for meta-analysis and data heterogeneity assessment. Results: Thirteen studies meeting eligibility criteria were identified comprising 1,597,303 participants. Abstract: Pelvic floor morbidity prevalence was Urinary Incontinence (UI) 27.9% (5411 patients in 7 studies with reported cases), Pelvic Organ Prolapse (POP) 14.2% (6019 patients in 8 studies with reported cases), and Anal Incontinence (AI) 0.4% (1,589,740 patients in 5 studies with reported cases). Our meta-analyses revealed significantly higher rates of all three morbidities and overall morbidity in the VD versus CD group: UI OR = 2.17, 95% CI 1.64–2.87, p for heterogeneity ≤ 0.0001, I2 = 84%; POP OR = 3.28, 95% CI 1.91–5.63, p for heterogenicity ≤ 0.043, I2 = 63%; AI OR = 1.53, 95% CI 1.32–1.77; p for heterogeneity ≤ 0.291, I2 = 20%; and overall morbidity (OR = 2.17, 95% CI 1.64–2.87; p for heterogeneity ≤ 0.0001, I2 = 84%). Conclusion: Vaginal delivery is directly related to the appearance of pelvic floor disorders, mainly UI, POP, and AI. The risk of POP should be taken into higher consideration after vaginal delivery and postpartum follow-up should be performed, to identify and/or treat it at the earliest stages
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