687 research outputs found

    Oxidative stress: new insights on the association of nonalcoholic fatty liver disease and atherosclerosis

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    Non-alcoholic fatty liver disease (NAFLD) represents the most common and emerging chronic liver disease worldwide. It includes a wide spectrum of liver diseases ranging from simple fatty liver to non-alcoholic steatohepatitis (NASH), which may progress to fibrosis and more severe liver complications such as cirrhosis, hepatocellular carcinoma and liver mortality. NAFLD is strongly associated with obesity, insulin resistance, hypertension, and dyslipidaemia, and is now regarded as the liver manifestation of the metabolic syndrome. The increased mortality of patients with NAFLD is primarily a result of cardiovascular disease and, to a lesser extent, to liver related diseases. Increased oxidative stress has been reported in both patients with NAFLD and patient with cardiovascular risk factors. Thus, oxidative stress represents a shared pathophysiological disorder between the two conditions. Several therapeutic strategies targeting oxidative stress reduction in patients with NAFLD have been proposed, with conflicting results. In particular, vitamin E supplementation has been suggested for the treatment of non-diabetic, non-cirrhotic adults with active NASH, although this recommendation is based only on the results of a single randomized controlled trial. Other antioxidant treatments suggested are resveratrol, silybin, L-carnitine and pentoxiphylline. No trial so far, has evaluated the cardiovascular effects of antioxidant treatment in patients with NAFLD. New, large-scale studies including as end-point also the assessment of the atherosclerosis markers are needed

    Epigenetics: new questions on the response to hypoxia

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    Reduction in oxygen levels below normal concentrations plays important roles in different normal and pathological conditions, such as development, tumorigenesis, chronic kidney disease and stroke. Organisms exposed to hypoxia trigger changes at both cellular and systemic levels to recover oxygen homeostasis. Most of these processes are mediated by Hypoxia Inducible Factors, HIFs, a family of transcription factors that directly induce the expression of several hundred genes in mammalian cells. Although different aspects of HIF regulation are well known, it is still unclear by which precise mechanism HIFs activate transcription of their target genes. Concomitantly, hypoxia provokes a dramatic decrease of general transcription that seems to rely in part on epigenetic changes through a poorly understood mechanism. In this review we discuss the current knowledge on chromatin changes involved in HIF dependent gene activation, as well as on other epigenetic changes, not necessarily linked to HIF that take place under hypoxic conditions.Fil: Perez Perri, Joel Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquimicas de Buenos Aires; Argentina. Fundación Instituto Leloir; ArgentinaFil: Acevedo, Julieta Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquimicas de Buenos Aires; Argentina. Fundación Instituto Leloir; ArgentinaFil: Wappner, Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquimicas de Buenos Aires; Argentina. Fundación Instituto Leloir; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentin

    EARLIEST TRIASSIC CONODONTS FROM CHITRAL, NORTHERNMOST PAKISTAN

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    Extensive tracts of very shallow water carbonates in the valleys of the Yarkhun and Mastuj rivers of Chitral (northernmost Pakistan) previously though to be Permian (or Cretaceous) are shown by conodonts from two horizons in sequences 110 km apart—near Torman Gol (Mastuj valley) and near Sakirmul (upper Yarkhun valley)—to include earliest Triassic (Scythian—Induan) horizons. Both faunas have Isarcicella staeschei Dai & Zhang, Is. lobata Perri, Is. turgida (Kozur et al.) and Hindeodus parvus (Kozur & Pjatakova), whereas Is. Isarcica (Huckriede) has been recognised only in the Torman Gol occurrence. The presence, respectively, of Is. staeschei in the Sakirmul and Is. isarcica in the Torman Gol occurrences, allows discrimination of the staeschei and isarcica zones respectively the third and the fourth conodont biozones of the Early Triassic conodont biozonation of Perri (in Perri & Farabegoli 2003). Such faunas, consisting mainly of isarcicellids and hindeodids but lacking gondolellids, are characteristic of restricted sea environments across the Permian–Triassic boundary and in the earliest Triassic in other Tethyan areas. The conodont faunas from these two occurrences are remarkably similar, nearly contemporaneous, and indicate shallow water biofacies. They are inferred to equate with the Ailak Dolomite, a sequence of Late Permian–?Late Triassic dolostones discriminated farther up the Yarkhun valley and extending eastwards into the upper Hunza region of northernmost Pakistan. The Zait Limestone and Sakirmul carbonate sequence are consistent with extension of the previously inferred Triassic carbonate platform at least 110 km farther to the SW than previously supposed

    Nurturing International Business research through Global Value Chains literature: A review and discussion of future research opportunities

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    This article offers a comprehensive and systematic review of the literature on Global Value Chains (GVCs). The GVC framework has received growing attention in the last decade, providing theoretical concepts and analytical tools to understand and assess patterns of value creation in view of the new international division of labour. In this area, a broad overlap of research interest exists with the international business (IB) literature. Yet, few interactions between the two fields of study have been recorded so far. Performing a quantitative content analysis on all academic publications on GVCs in the period 1994−2018, this paper describes the evolution of GVC studies, emphasizing points of contact and potential synergies with the IB literature. It also identifies research opportunities along the four key dimensions of the GVC framework: geographical and industrial scope, governance, upgrading, and institutional context

    Morphological characterization of uterus and oviducts of Nelore bovine fetuses (Bos primigenius indicus) at various gestation stages

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    For the accomplishment of this research, twenty Nelore female fetuses in different phases of gestation were collected. The uterine horns and oviducts were dissected, measured and fragments were fixed in 4.00% tamponed paraformaldeid, processed and enclosed in paraplastic. The sections of 5mm were stained with hematoxilin and eosin, Masson's trichrome (to colagens fibers), Verhoeff (to elastic fibers) and with reticulin (to reticular fibers). The results showed that there is no significative difference among the right and left sides for the uterine horns and oviducts, but there is correlation among the measured organs in function of the age of the fetuses, or either, the growth of uterine horns and oviducts follow the fetal growth. The covering epithelium of the uterus does not present morphologic variations during the analyzed period. From 23 weeks of gestation, the mucous layer presents evolution in the development of the projections and there is no appearance of endometrial glands in the uterine wall in the analyzed period. The muscular layer presents only the developed internal circular sublayer up to 23 weeks of gestation and from 24 weeks of gestation there is presence of two sublayers. The serous layer is typical and it does not show variability in the gestation. The oviducts presents growth differences, mainly to the development of the folds that from 23 weeks of gestation they had become higher and ramified, however without appearance of tertiary folds. In the fetal development, the epithelium cilium becomes bigger. Up to 32 weeks of gestation, the muscular layer of oviducts presents the internal circular sublayer. The serous layer and mesosalpinge are typical and they do not present variations. The more characteristics variations occurred from 23 weeks of gestation.Para a realização desta pesquisa, foram coletados vinte fetos fêmeas em diferentes fases de gestação da raça Nelore. Os cornos uterinos e as tubas uterinas foram dissecados, mensurados e os fragmentos fixados em paraformaldeído tamponado a 4,00%, processados e incluídos em paraplástico. Os cortes com 5 mm foram corados com hematoxilina e eosina, tricrômio de Masson (para fibras colágenas), Verhoeff (para fibras elásticas) e com reticulina (para fibras reticulares). Os resultados mostraram que não há diferença significativa das mensurações entre os lados direito e esquerdo para os cornos uterinos e tubas uterinas, porém há correlação entre os valores obtidos das mensurações dos órgãos em função da idade dos fetos, ou seja, o crescimento dos órgãos acompanha o crescimento fetal. O epitélio de revestimento do útero não apresenta variações morfológicas evidentes no período analisado. A partir de 23 semanas de gestação, a mucosa uterina apresenta evolução marcante no desenvolvimento das projeções e não há aparecimento de glândulas endometriais na parede uterina no período analisado. A camada muscular apresenta a subcamada circular interna desenvolvida até 23 semanas de gestação e a partir de 24 semanas há presença das duas subcamadas. A camada serosa é típica e não mostra variabilidade no decorrer da gestação. As tubas uterinas apresentam diferenças de crescimento, principalmente dos pregueamentos que a partir de 23 semanas de gestação tornaram-se mais altos e ramificados, porém sem aparecimento de pregas terciárias. Com o desenvolvimento fetal, os cílios epiteliais do pregueamento tubárico são maiores em tamanho e em número. Até 32 semanas de gestação, a camada muscular das tubas uterinas apresenta apenas a subcamada circular interna. A camada serosa e o mesosalpinge são típicos e não apresentam variações importantes. As variações mais marcantes para os órgãos estudados ocorreram a partir de 23 semanas de gestação

    PROTOGNATHODUS (CONODONTA) AND ITS POTENTIAL AS A TOOL FOR DEFINING THE DEVONIAN/CARBONIFEROUS BOUNDARY

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    The current definition of the Devonian/Carboniferous boundary is the first occurrence of the conodont Siphonodella sulcata. Due to difficulties in identification of the early siphonodellids, such as S. praesulcata and S. sulcata, investigation of Protognathodus which enters in the latest Devonian and extends into the Mississippian, was undertaken to determine use as a better indicator of the base of the Carboniferous. During the D/C boundary interval, Protognathus is represented by four species: Pr. meischneri, Pr. collinsoni, Pr. kockeli and Pr. kuehni.Although Pr. kockeli can be abundant in boundary interval sections, none of the four Protognathodus species has a high potential as a tool for redefining the D/C boundary, based on regional variation in first occurrence data, restricted stratigraphic ranges and global distribution, poorly understood facies occurrences, as well as general rarity of the taxa.

    Current Genetic Epidemiology of β-Thalassemias and Structural Hemoglobin Variants in the Lazio Region (Central Italy) Following Recent Migration Movements

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    The aim of this study was to describe the changing pattern of mutational spectrum of β-thalassemia (β-thal) in the Lazio region (Central Italy), as consequence of recent demographic variations. From 1994 until present, 256 immigrant subjects with hemoglobin disorders (including 191 heterozygotes and 65 homozygotes or compound heterozygotes) coming from 44 different foreign countries, have been molecularly characterized. 14 β-globin gene mutations were identified and their frequencies reflect different ethnic origins: 8 of these mutations account for 76.97% of all molecular defects, while 6 of them are much rare, representing less than 2% of the total. These data differ, both in type and percentage, from the mutational spectrum detected in the native population in 1995. Since a few defects are prevalent in each country, a proper strategy for the identification of mutations in immigrant individuals relies on the prior knowledge of their frequency in native ethnic group

    Kaolin protects olive fruits from Bactrocera oleae (Gmelin) infestations unaffecting olive oil quality

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    The efficacy of the processed kaolin “Surround WP” to control olive fruit fly, Bactrocera oleae Gmelin, field infestations was investigated in east Calabria. The preliminary results showed that fruit infestation levels were significantly reduced on kaolin-treated trees compared with untreated trees. The promising results of these experiments points to the feasibility of using particle film technology composed of a non-toxic material, to avoid olive fly damage as an alternative to the applications of rotenone in organic orchards. Finally, kaolin treatment unaffected the nutritional and sensory quality parameters of the corresponding virgin olive oils obtained by a laboratory scale olive mill, thus satisfying the present quality requirements

    Malocclusion and rhinitis in children: an easy-going relationship or a yet to be resolved paradox? A systematic literature revision

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    Objective: The relation between nasal flow and malocclusion represents a practical concern to pediatricians, otorhinolaryngologists, orthodontists, allergists and speech therapists. If naso-respiratory function may influence craniofacial growth is still debated. Chronic mouth-breathing is reported to be associated also with a characteristic pattern of dental occlusion. On the other hand, also malocclusion may reduce nasal air flows promoting nasal obstruction. Hereby, the aim of this review was to describe the relationship between rhinitis and malocclusion in children. Methods: An electronic search was conducted using online database including Pubmed, Web of Science, Google Scholar and Embase. All studies published through to January 30, 2017 investigating the prevalence of malocclusion in children and adolescents (aged 0-20 years) affected by rhinitis and the prevalence of rhinitis in children with malocclusion were included. The protocol was registered at PROSPERO - International prospective register of systematic reviews under CRD42016053619. Results: Ten studies with 2733 patients were included in the analysis. The prevalence of malocclusion in children with rhinitis was specified in four of the studies ranging from as high as 78.2% to as low as 3%. Two out of the studies reported the prevalence of rhinitis in children with malocclusion with a rate ranging from 59.2 to 76.4%. Conclusion: The results of this review underline the importance of the diagnosis and treatment of the nasal obstruction at an early age to prevent an altered facial growth, but the data currently available on this topic do not allow to establish a possible causal relationship between rhinitis and malocclusion
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