1,635 research outputs found

    Visualization of the three-dimensional structure of the human centromere in mitotic chromosomes by super-resolution microscopy

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    The human centromere comprises large arrays of repetitive alpha-satellite DNA at the primary constriction of mitotic chromosomes. In addition, centromeres are epigenetically specified by the centromere-specific histone H3 variant CENP-A that supports kinetochore assembly to enable chromosome segregation. Since CENP-A is bound to only a fraction of the alpha-satellite elements within the megabase-sized centromere DNA, correlating the three-dimensional (3D) organization of alpha-satellite DNA and CENP-A remains elusive. To visualize centromere organization within a single chromatid, we used a combination of the Centromere Chromosome Orientation Fluorescent In Situ Hybridization (Cen-CO-FISH) technique together with Structured Illumination Microscopy (SIM). Cen-CO-FISH allows the differential labeling of the sister chromatids without the denaturation step used in conventional FISH that may affect DNA structure. Our data indicate that alpha-satellite DNA is arranged in a ring-like organization within prometaphase chromosomes, in presence or absence of spindle's microtubules. Using expansion microscopy (ExM), we found that CENP-A organization within mitotic chromosomes follows a rounded pattern similar to that of alpha-satellite DNA, often visible as a ring thicker at the outer surface oriented towards the kinetochore-microtubules interface. Collectively, our data provide a 3D reconstruction of alpha-satellite DNA along with CENP-A clusters that outline the overall architecture of the mitotic centromere. [Media: see text] [Media: see text] [Media: see text] [Media: see text

    Herbicidal potential of phenolic and cyanogenic glycoside compounds isolated from Mediterranean plants

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    This study was conducted to test five phenolic and cyanogenic glycoside compounds for growth regulating activity on the germination and seedling growth of Portulaca oleracea L., Amaranthus retroflexus L., and Lactuca sativa L. at different concentrations. Overall, the tested compounds revealed growth-regulating activity in species-specific and concentration dependent manner. The most powerful effects were much pronounced on seedling growth rather than on germination. In fact, the compounds 1 (amygdalin) and 2 (salicylic acid) were the most phytotoxic on root growth of  P. oleracea, and they caused, respectively, an inhibition of 55% and 85% at 10-6 M and 10-4 M. On the other hand, the lettuce seedling growth was more sensitive than weeds growth to the compounds 4 (3,4,5-trihydroxybenzoic acid) and 5 (7-hydroxycoumarin), which exhibited a moderate inhibition at the highest concentration. This selectivity and specificity of these active allelopathic compounds could be very useful for the development of new application of natural substances to control the aggressive weeds. Thus, our findings suggest that the integration of these compounds may maintain irrigation system and reduce the massive use of agrochemicals in agro-ecosystems

    The “Special” crystal-Stellate System in Drosophila melanogaster Reveals Mechanisms Underlying piRNA Pathway-Mediated Canalization

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    The Stellate-made crystals formation in spermatocytes is the phenotypic manifestation of a disrupted crystal-Stellate interaction in testes of Drosophila melanogaster. Stellate silencing is achieved by the piRNA pathway, but many features still remain unknown. Here we outline the important role of the crystal-Stellate modifiers. These have shed light on the piRNA pathways that defend genome integrity against transposons and other repetitive elements in the gonads. In particular, we illustrate the finding that HSP90 participates in the molecular pathways of piRNA production. This observation has relevance for the mechanisms underlying the evolutionary canalization process

    Nusinersen Induces Disease-Severity-Specific Neurometabolic Effects in Spinal Muscular Atrophy

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    Intrathecal delivery of Nusinersen-an antisense oligonucleotide that promotes survival motor neuron (SMN) protein induction-is an approved therapy for spinal muscular atrophy (SMA). Here, we employed nuclear magnetic resonance (NMR) spectroscopy to longitudinally characterize the unknown metabolic effects of Nusinersen in the cerebrospinal fluid (CSF) of SMA patients across disease severity. Modulation of amino acid metabolism is a common denominator of biochemical changes induced by Nusinersen, with distinct downstream metabolic effects according to disease severity. In severe SMA1 patients, Nusinersen stimulates energy-related glucose metabolism. In intermediate SMA2 patients, Nusinersen effects are also related to energy homeostasis but involve ketone body and fatty acid biosynthesis. In milder SMA3 patients, Nusinersen mainly modulates amino acid metabolism. Moreover, Nusinersen modifies the CSF metabolome of a more severe clinical group towards the profile of untreated SMA patients with milder disease. These findings reveal disease severity-specific neurometabolic signatures of Nusinersen treatment, suggesting a selective modulation of peripheral organ metabolism by this CNS-directed therapy in severe SMA patients

    Role of magnetic resonance imaging in the preoperative staging and work-up of patients affected by invasive lobular carcinoma or invasive ductolobular carcinoma

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    Purpose. The prevalence of invasive lobular carcinoma (ILC), the second most common type of breast cancer, accounts for 5%–15% of all invasive breast cancer cases. Its histological feature to spread in rows of single cell layers explains why it often fails to form a palpable lesion and the lack of sensitivity of mammography and ultrasound (US) to detect it. It also has a higher incidence of multifocal, multicentric, and contralateral disease when compared to the other histological subtypes. The clinicopathologic features and outcomes of Invasive Ductolobular Carcinoma (IDLC) are very similar to the ILC. The purpose of our study is to assess the importance of MRI in the preoperative management and staging of patients affected by ILC or IDLC. Materials and Methods. We identified women diagnosed with ILC or IDLC. We selected the patients who had preoperative breast MRI. For each patient we identified the areas of multifocal, multicentric, or contralateral disease not visible to standard exams and detected by preoperative MRI. We analyzed the potential correlation between additional cancer areas and histological cancer markers. Results. Of the 155 women who met our inclusion criteria, 93 (60%) had additional cancer areas detected by MRI. In 61 women, 39,4% of the overall population, the additional cancer areas were confirmed by US/tomosynthesis second look and biopsy. Presurgical MRI staging changed surgical management in the 37,4% of the patients. Only six patients of the overall population needed a reoperation after the initial surgery. No statistically significant correlation was found between MRI overestimation and the presence of histological peritumoral vascular/linfatic invasion. No statistically significant correlation was found between additional cancer areas and histological cancer markers. Conclusions. Our study suggests that MRI is an important tool in the preoperative management and staging of patients affected by lobular or ductolobular invasive carcinoma

    Disease Reactivation after Fingolimod Discontinuation in Pregnant Multiple Sclerosis Patients

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    Recent studies estimated an incidence of 4-25% of disease rebound after withdrawal of fingolimod (FTY) for any reason, but specific data on disease reactivation after FTY withdrawal due to pregnancy are limited. The aim of the study was to evaluate the frequency and predictors of disease reactivation in patients who stopped FTY for pregnancy. A multicentre retrospective cohort study was conducted in four Italian MS centres in 2013-2019. Both planned and unplanned pregnancies were included. The annualized relapse rate (ARR) was calculated before FTY treatment, during FTY treatment, during pregnancy and during the year after delivery. In total, 27 patients (mean age 29 years) were included. The ARR 1 year before FTY treatment was 1.3. Patients were exposed to FTY for a median of 2.9 years. The ARR was 0.04 during the last year before conception (p < 0.001 compared with the ARR before FTY treatment). Eleven patients became pregnant after a mean of 88 days following FTY discontinuation, whereas 16 patients stopped FTY after pregnancy confirmation. Relapses were observed in 22% of patients during pregnancy and in 44% in the postpartum period. ARR increased both during pregnancy (0.49; p = 0.027) and in the first year after delivery (0.67; p < 0.001) compared to the last year before pregnancy. Compared with radiological assessment before pregnancy, more patients showed new or enlarging T2 lesions (63% vs 30%; p = 0.02) and gadolinium-enhancing lesions (44% vs 0; p = 0.0001) on brain Magnetic Resonance Imaging. Relapses during pregnancy were the only significant predictor for postpartum relapses (OR 1.9, 95% CI 1.11-3.1). One case of spontaneous abortion and no cases of abnormal foetal development were observed. Despite adequate and prolonged control of disease activity, women who discontinue FTY because of pregnancy are at risk for disease reactivation. In patients who relapsed during pregnancy, the initiation of high-efficacy disease modifying drugs (DMDs) soon after delivery is advisable to prevent postpartum relapses

    Contribution to the ecology of the Italian hare (Lepus corsicanus)

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    the italian hare (Lepus corsicanus) is endemic to Central-Southern Italy and Sicily, classified as vulnerable due to habitat alterations, low density and fragmented populations and ecological competition with the sympatric european hare (Lepus europaeus). Despite this status, only few and local studies have explored its ecological features. We provided some key traits of the ecological niche of the italian hare as well as its potential distribution in the italian peninsula. All data derived from genetically validated presences. We generated a habitat suitability model using maximum entropy distribution model for the italian hare and its main competitor, the european hare. the dietary habits were obtained for the italian hare with DnA metabarcoding and High-throughput Sequencing on faecal pellets. The most relevant environmental variables affecting the potential distribution of the italian hare are shared with the european hare, suggesting a potential competition. the variation in the observed altitudinal distribution is statistically significant between the two species.The diet of the Italian hare all year around includes 344 plant taxa accounted by 62 families. The Fagaceae, Fabaceae, Poaceae, Rosaceae and Solanaceae (counts > 20,000) represented the 90.22% of the total diet. Fabaceae (60.70%) and Fagaceae (67.47%) were the most abundant plant items occurring in the Spring/Summer and Autumn/Winter diets, respectively. the Spring/Summer diet showed richness (N = 266) and diversity index values (Shannon: 2.329, Evenness: 0.03858, Equitability: 0.4169) higher than the Autumn/Winter diet (N = 199, Shannon: 1.818, Evenness: 0.03096, Equitability: 0.3435). Our contribution adds important information to broaden the knowledge on the environmental (spatial and trophic) requirements of the Italian hare, representing effective support for fitting management actions in conservation planning

    A multi-parametric investigation on waterlogged wood using a magnetic resonance imaging clinical scanner

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    In cultural heritage conservation science, moisture content (MC) is an essential factor to determine. At the same time, it is essential to choose non-destructive and non-invasive approaches for more sustainable investigations and make them safe for the environment and the sample. The question addressed in this work concerns the possibility and the opportunity to investigate waterlogged wood by using nuclear magnetic resonance imaging (MRI) clinical scanners to carry out non-destructive volumetric diagnostics. In this study, MRI, the most important non-invasive medical imaging technique for human tissue analysis, was applied to study archaeological waterlogged wood samples. This type of archaeological material has a very high moisture content (400%–800%), thus, it is an ideal investigative subject for MRI which detects water molecules inside matter. By following this methodology, it was possible to obtain information about water content and conservation status through a T1, T2, and T2* weighted image analysis, without any sampling or handling, and the samples were directly scanned in the water where they were stored. Furthermore, it permited processing 3D reconstruction, which could be an innovative tool for the digitalization of marine archaeological collections. In this work, 16 modern species of wood and a waterlogged archaeological wood sample were studied and investigated using a clinical NMR scanner operating at 3T. The results were compared with X-ray computed tomography (CT) images, as they had already been used for dendrochronology. The comparison highlights the similar, different, and complementary information about moisture content and conservation status in an all-in-one methodology obtainable from both MRI and CT techniques

    Growth and Welfare of Rainbow Trout (Oncorhynchus mykiss) in Response to Graded Levels of Insect and Poultry By-Product Meals in Fishmeal-Free Diets

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    This study compared the nutrient-energy retention, digestive function, growth performance, and welfare of rainbow trout (ibw 54 g) fed isoproteic (42%), isolipidic (24%), fishmeal-free diets (CV) over 13 weeks. The diets consisted of plant-protein replacement with graded levels (10, 30, 60%) of protein from poultry by-product (PBM) and black soldier fly H. illucens pupae (BSFM) meals, either singly or in combination. A fishmeal-based diet was also tested (CF). Nitrogen retention improved with moderate or high levels of dietary PBM and BSFM relative to CV (p < 0.05). Gut brush border enzyme activity was poorly affected by the diets. Gastric chitinase was up-regulated after high BSFM feeding (p < 0.05). The gut peptide and amino acid transport genes were differently regulated by protein source and level. Serum cortisol was unaffected, and the changes in metabolites stayed within the physiological range. High PBM and high BSFM lowered the leukocyte respiratory burst activity and increased the lysozyme activity compared to CV (p < 0.05). The BSFM and PBM both significantly changed the relative percentage of lymphocytes and monocytes (p < 0.05). In conclusion, moderate to high PBM and BSFM inclusions in fishmeal-free diets, either singly or in combination, improved gut function and nutrient retention, resulting in better growth performance and the good welfare of the rainbow trout
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