796 research outputs found
Genomic diversity and population structure analysis reveal few genetic differences among Ethiopian indigenous sheep populations
African sheep, like other domestic sheep, are domesticated
from the Asiatic mouflon (Ovis orientalis). They entered the continent
through the North and the Horn of Africa regions following
maritime and terrestrial trading routes. Ethiopia is one of the main
entry points of various plant and animal domesticates into Africa.
It is characterised by diverse agro-ecologies, ancient human ethnic
diversity and the presence of indigenous sheep breeds/populations
of unprecedented morphological diversity (e.g. tail types). Here, we
investigate the genome diversity and population structure of 146
unrelated animals from 11 Ethiopian indigenous sheep populations.
DNA was extracted from ear tissue punches and genotyped with the
Illumina Ovine 50K SNP BeadChip assay. Sheep populations from
The Caribbean, Europe, Middle East and China as well as from
western, northern and southern Africa were included to clarify the
genetic history of origin, introduction and dispersal of the species
into Ethiopia. Principal component analysis (PCA), clearly separated
all Ethiopian sheep from the other populations. Population structure
and phylogenetic (neighbour-joining tree) analysis subdivided
the Ethiopian indigenous sheep into three genetic clusters corresponding
to their tail morphology (rump fat-tailed, short fat-tailed
and long fat/thin-tailed population). It supports a common genetic ancestry for populations of each tail type in the country. Genetic distances
among the Ethiopian populations were positively correlated
with geographic distances (Mantel test, P < 0.001, r = 0.465) and the
highest genetic diversity was recorded in the fat-tailed (short, rump
and/or long fat-tailed) close to the Bab-el-Mandeb strait. However,
despite their distinct morphology and separate geographic distribution,
little genetic differentiation between Ethiopian populations are
observed. This is most likely a consequence of their ancient and
modern intermixing following their introduction into the country
Lymph node ratio is an important and independent prognostic factor for patients with stage III melanoma
INTRODUCTION:
The incidence of melanoma is dramatically increasing worldwide. We hypothesized that the ratio of metastatic to examined lymph node ratio (LNR) would be the most important prognostic factor for stage III patients. METHODS:
We retrospectively reviewed our institutional database of melanoma patients and identified 168 patients who underwent lymph node dissection (LND) for stage III disease between 1993 and 2007. Patients were divided into three groups based on LNR (≤10%, n = 93; 10-≤25%, n = 45; and \u3e25%, n = 30). Univariate and multivariate analysis was performed using Cox proportional hazards model. RESULTS:
The median survival time of the entire group of patients was 34 months. The median number of positive nodes was 2 (range = 1, 55), and the median number of examined nodes was 22 (range = 5-123). Tumor characteristics of the primary melanoma (such as thickness, ulceration, and primary site) were not significant predictors of survival in this analysis. By univariate analysis, LNR was an important prognostic factor. Patients with LNR 10-25% and \u3e25% had decreased survival compared to those patients with LNR ≤10% (HR = hazard ratio = 2.0 and 3.1, respectively; P ≤ 0.005). The number of positive lymph nodes also impacted on survival (P = 0.001). In multivariate analysis, LNR of 10-25% and \u3e25% predicted survival (HR = 2.5 and 4.0, respectively). CONCLUSION:
LNR is an important prognostic factor in patients undergoing LND for stage III melanoma. It can be used to stratify patients being considered for adjuvant therapy trials and should be evaluated using a larger prospective database
Exploring genome-wide differentiation and signatures of selection in Italian and North American Holstein populations
Among Italian dairy cattle, the Holstein is the most reared breed for the production of Parmigiano Reggiano protected designation of origin cheese, which represents one of the most renowned products in the entire Italian dairy industry. In this work, we used a medium-density genome-wide data set consisting of 79,464 imputed SNPs to study the genetic structure of Italian Holstein breed, including the population reared in the area of Parmigiano Reggiano cheese production, and assessing its distinctiveness from the North American population. Multidimensional scaling and ADMIXTURE approaches were used to explore the genetic structure among populations. We also investigated putative genomic regions under selection among these 3 populations by combining 4 different statistical methods based either on allele frequencies (single marker and window-based) or extended haplotype homozygosity (EHH; standardized log-ratio of integrated EHH and cross-population EHH). The genetic structure results allowed us to clearly distinguish the 3 Holstein populations; however, the most remarkable difference was observed between Italian and North American stock. Selection signature analyses identified several significant SNPs falling within or closer to genes with known roles in several traits such as milk quality, resistance to disease, and fertility. In particular, a total of 22 genes related to milk production have been identified using the 2 allele frequency approaches. Among these, a convergent signal has been found in the VPS8 gene which resulted to be involved in milk traits, whereas other genes (CYP7B1, KSR2, C4A, LIPE, DCDC1, GPR20, and ST3GAL1) resulted to be associated with quantitative trait loci related to milk yield and composition in terms of fat and protein percentage. In contrast, a total of 7 genomic regions were identified combining the results of standardized log-ratio of integrated EHH and cross-population EHH. In these regions candidate genes for milk traits were also identified. Moreover, this was also confirmed by the enrichment analyses in which we found that the majority of the significantly enriched quantitative trait loci were linked to milk traits, whereas the gene ontology and pathway enrichment analysis pointed to molecular functions and biological processes involved in AA transmembrane transport and methane metabolism pathway. This study provides information on the genetic structure of the examined populations, showing that they are distinguishable from each other. Furthermore, the selection signature analyses can be considered as a starting point for future studies in the identification of causal mutations and consequent implementation of more practical application
Active PD-L1 incorporation within HIV virions functionally impairs T follicular helper cells.
The limited development of broadly neutralizing antibodies (BnAbs) during HIV infection is classically attributed to an inadequate B-cell help brought by functionally impaired T follicular helper (Tfh) cells. However, the determinants of Tfh-cell functional impairment and the signals contributing to this condition remain elusive. In the present study, we showed that PD-L1 is incorporated within HIV virions through an active mechanism involving p17 HIV matrix protein. We subsequently showed that in vitro produced PD-L1high but not PD-L1low HIV virions, significantly reduced Tfh-cell proliferation and IL-21 production, ultimately leading to a decreased of IgG1 secretion from GC B cells. Interestingly, Tfh-cell functions were fully restored in presence of anti-PD-L1/2 blocking mAbs treatment, demonstrating that the incorporated PD-L1 proteins were functionally active. Taken together, the present study unveils an immunovirological mechanism by which HIV specifically exploits the regulatory potential of PD-L1 to suppress the immune system during the course of HIV infection
Spatial and topological organization of DNA chains induced by gene co-localization
Transcriptional activity has been shown to relate to the organization of
chromosomes in the eukaryotic nucleus and in the bacterial nucleoid. In
particular, highly transcribed genes, RNA polymerases and transcription factors
gather into discrete spatial foci called transcription factories. However, the
mechanisms underlying the formation of these foci and the resulting topological
order of the chromosome remain to be elucidated. Here we consider a
thermodynamic framework based on a worm-like chain model of chromosomes where
sparse designated sites along the DNA are able to interact whenever they are
spatially close-by. This is motivated by recurrent evidence that there exists
physical interactions between genes that operate together. Three important
results come out of this simple framework. First, the resulting formation of
transcription foci can be viewed as a micro-phase separation of the interacting
sites from the rest of the DNA. In this respect, a thermodynamic analysis
suggests transcription factors to be appropriate candidates for mediating the
physical interactions between genes. Next, numerical simulations of the polymer
reveal a rich variety of phases that are associated with different topological
orderings, each providing a way to increase the local concentrations of the
interacting sites. Finally, the numerical results show that both
one-dimensional clustering and periodic location of the binding sites along the
DNA, which have been observed in several organisms, make the spatial
co-localization of multiple families of genes particularly efficient.Comment: Figures and Supplementary Material freely available on
http://dx.doi.org/10.1371/journal.pcbi.100067
Reversible Keap1 inhibitors are preferential pharmacological tools to modulate cellular mitophagy
Mitophagy orchestrates the autophagic degradation of dysfunctional mitochondria preventing their pathological accumulation and contributing to cellular homeostasis. We previously identified a novel chemical tool (hereafter referred to as PMI), which drives mitochondria into autophagy without collapsing their membrane potential (ΔΨm). PMI is an inhibitor of the protein-protein interaction (PPI) between the transcription factor Nrf2 and its negative regulator, Keap1 and is able to up-regulate the expression of autophagy-associated proteins, including p62/SQSTM1. Here we show that PMI promotes mitochondrial respiration, leading to a superoxide-dependent activation of mitophagy. Structurally distinct Keap1-Nrf2 PPI inhibitors promote mitochondrial turnover, while covalent Keap1 modifiers, including sulforaphane (SFN) and dimethyl fumarate (DMF), are unable to induce a similar response. Additionally, we demonstrate that SFN reverses the effects of PMI in co-treated cells by reducing the accumulation of p62 in mitochondria and subsequently limiting their autophagic degradation. This study highlights the unique features of Keap1-Nrf2 PPI inhibitors as inducers of mitophagy and their potential as pharmacological agents for the treatment of pathological conditions characterized by impaired mitochondrial quality control
Tracking Zebu Introgression in Mediterranean Cattle Breeds
A recent work investigating genetic origin, admixture and population history of primitive European cattle highlighted, by using genome-wide
single nucleotide polymorphisms, zebu gene flow in the Balkan and Italian Podolic cattle populations. Haemoglobin protein polymorphism
analysis in Italian breeds highlighted the presence of zebuine markers in both Italian Podolic and Alpine Grey cattle. Based on the above
evidences, we here specifically look for genomic regions of zebuine ancestry in a different dataset of 50K genotypes from Mediterranean breeds
including 29 Marismena (Spain); 30 Bazadaise and 30 Gasconne (France); 24 Alpine Grey, 97 Piemontese, 51 Chianina, 5 Marchigiana, 121
Romagnola, 24 Podolica, 24 Modenese, 30 Reggiana, 30 Cinisara and 30 Modicana (Italy); 24 Guelmoise (Algeria); 24 Cika (Slovenia), 43
Illyrian Mountain Bu\u161a (Albania). Additional taurine and zebuine breeds from previously published studies are also included in the analyses.
Special emphasis in genetic analyses is also given to the identification of genomic regions potentially associated with a phenotypic trait observed
in several taurine breeds as well as in some zebuine breeds, characterized by calves having a fawn coat at birth, while turning to various shades
of grey in adult animals. The obtained results contribute to a better characterization of history and genetic structure of Mediterranean cattle
breeds
Autologous tooth graft after endodontical treated used for socket preservation: A multicenter clinical study.
The aim of the study was to evaluate the tooth extracted use as autologous tooth graft after endodontic root canal therapies used for socket preservation. To this purpose, the Tooth Transformer shredding and decontamination machine has been used. The graft obtained in this way, was inserted at the time of the extraction or at a second surgery altogether with the chosen regenerative therapy. This clinical trial enrolled patients with post-estractive defects requiring the restoration bone dimension and shape in the maxillary and mandibular zone. In addition, 98 patients with 119 extraction sockets were enrolled across 10 standardized centers. An innovative preparation method, using the dedicated automated device Tooth Transformer, able to transform autologous teeth in suitable grafting material, has been used. The extracted tooth was cleaned and treated using a Tooth Transformer and made a socket preservation. Thirteen Biopsies were realized to analyze the histologic outcomes at the average time of four months to demonstrate that the autologous tooth graft made from root after endodontic therapy should be used in human bone regeneration as graft for dental implant placement
Global metabolic analyses of acinetobacter baumannii
Acinetobacter baumannii is rapidly emerging as a multidrug-resistant pathogen responsible for nosocomial infections including pneumonia, bacteremia, wound infections, urinary tract infections, and meningitis. Metabolomics provides a powerful tool to gain a system-wide snapshot of cellular biochemical networks under defined conditions and has been increasingly applied to bacterial physiology and drug discovery. Here we describe an optimized sample preparation method for untargeted metabolomics studies in A. baumannii. Our method provides a significant recovery of intracellular metabolites to demonstrate substantial differences in global metabolic profiles among A. baumannii strains
Trayectorias laborales de jóvenes trabajadores de la actividad vitivinícola : departamento Maipú, Mendoza
La presente investigación tuvo como eje los vínculos entre educación y trabajo en la vitivinicultura mendocina desde 1990 . El objetivo general fue comprender los procesos de incorporación de jóvenes de ambos sexos al mundo del trabajo y su vínculo con las estrategias de formación y los esquemas de percepción en el mercado vitivinícola mendocino desde los 90. Se analizaron e identificaron los tipos de trayectorias educativas, laborales y transiciones existentes en los jóvenes. También los condicionantes de género que operan desde la perspectiva de las mujeres jóvenes. Se buscó comprender las formas que adquieren, cómo se manifiestan y varían las perspectivas acerca del trabajo, de las exigencias laborales y las condiciones del mercado de trabajo a lo largo de las trayectorias educativas y laborales y cuáles son los principales elementos constitutivos de las trayectorias de inserción, qué factores están asociados a sus variaciones y cómo se vinculan con las expectativas y estrategias de formación de inserción laboral.Fil: Martín, María Eugenia.
CONICET (Consejo Nacional de Investigaciones Científicas y Técnicas) - Universidad Nacional de CuyoFil: Zamarbide, Gabriela.
Universidad Nacional de Cuy
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