2,893 research outputs found

    Parentage assignment of progeny in mixed milt fertilization of Caspian brown trout Salmo trutta caspius using microsatellite DNA markers: Implications for conservation

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    Parentage of a stock of mixed milt produced progeny in current artificial breeding protocol of endangered Caspian brown trout, Salmo trutta caspius, was determined using three microsatellite loci chosen after a primary analysis of genetic diversity at nine microsatellite loci in the eight used breeder individuals. Overall, 98.8% of progeny were assigned to their parents using Family Assignment Program (FAP). Selection of hyper-variable microsatellites in Caspian brown trout to identify unique alleles was effective for unambiguous parentage determination and estimation of genetic diversity in this study. Effective population size of breeder individuals (Ne) was lower than the number of breeder individuals used (Nb) indicating unbalanced contribution of breeder individuals to progeny. Indeed, one of the four male breeder individuals produced about 70 % and the other three produced only from 4.86 % to 18.83 % of progeny. The average observed and expected heterozygosity of progeny (0.723 ± 0.011 and 0.684 ± 0.009, respectively) was significantly lower than that of their parents (0.833 and 0.800, respectively). Our data indicate that the current breeding protocol of Caspian brown trout may not provide equal opportunity for all the breeder individuals to contribute equally to progeny. Therefore, appropriate fertilization designs in the hatchery should be established in order to equalize the genetic contribution of different breeder individuals.Key words: Parentage assignment, effective population size, genetic diversity, Salmo trutta caspius

    Validation of whole-slide imaging in the primary diagnosis of liver biopsies in a University Hospital

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    BACKGROUND: Experience in the use of whole slide imaging (WSI) for primary diagnosis is limited and there are no comprehensive reports evaluating this technology in liver biopsy specimens. AIMS: To determine the accuracy of interpretation of WSI compared with conventional light microscopy (CLM) in the diagnosis of needle liver biopsies. METHODS: Two experienced liver pathologists blindly analyzed 176 consecutive biopsies from the Pathology Department at the Hospital Clinic of Barcelona. One of the observers performed the initial evaluation with CLM, and the second evaluation with WSI, whereas the second observer performed the first evaluation with WSI and the second with CLM. All slides were digitized in a Ventana iScan HT at 400x and evaluated with the Virtuoso viewer (Roche diagnostics). We used kappa statistics (kappa) for two observations. RESULTS: Intra-observer agreement between WSI and CLM evaluations was almost perfect (96.6%, kappa=0.9; 95% confidence interval [95% CI]: 0.9-1 for observer 1, and 90.3%, kappa=0.9; 95%CI: 0.8-0.9 for observer 2). Both native and transplantation biopsies showed an almost perfect concordance in the diagnosis. CONCLUSION: Diagnosis of needle liver biopsy specimens using WSI is accurate. This technology can reliably be introduced in routine diagnosis

    PADC Detected External Neutron Field by Nuclear Tracks at RFX-mod

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    Measured neutron signals relevant for plasma diagnostics on Reversed Field pinch eXperiment, RFX-mod, are obtained by nuclear track methodology with PADC-NtD’s. this technique provides the external neutron field values around the RFX-mod installation during pulsed operation. Charged particles from (n, p) and (n, α) reactions are related to formed latent tracks. these are etched in a thermoregulated water bath with a 6.25M, KOh solution at 60oC. Observed tracks were analyzed to determine track density from which neutron fluence spatial values should be derived. Results indicate that the neutron density in the surrounding environment change at most 40%. the epithermal component is 60% higher than that corresponding to the thermal region. the estimated neutron fluence for the whole experiment is 7.5×1010 neutrons cm2/s

    S-Adenosylmethionine revisited: its essential role in the regulation of liver function

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    Dietary methionine is mainly metabolized in the liver where it is converted into S-adenosylmethionine (AdoMet), the main biologic methyl donor. This reaction is catalyzed by methionine adenosyltransferase I/III (MAT I/III), the product of MAT1A gene, which is exclusively expressed in this organ. It was first observed that serum methionine levels were elevated in experimental models of liver damage and in liver cirrhosis in human beings. Results of further studies showed that this pathological alteration was due to reduced MAT1A gene expression and MAT I/III enzyme inactivation associated with liver injury. Synthesis of AdoMet is essential to all cells in the organism, but it is in the liver where most of the methylation reactions take place. The central role played by AdoMet in cellular function, together with the observation that AdoMet administration reduces liver damage caused by different agents and improves survival of alcohol-dependent patients with cirrhosis, led us to propose that alterations in methionine metabolism could play a role in the onset of liver disease and not just be a consequence of it. In the present work, we review the recent findings that support this hypothesis and highlight the mechanisms behind the hepatoprotective role of AdoMet

    Importance of a deficiency in S-adenosyl-L-methionine synthesis in the pathogenesis of liver injury

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    One of the features of liver cirrhosis is an abnormal metabolism of methionine--a characteristic that was described more than a half a century ago. Thus, after an oral load of methionine, the rate of clearance of this amino acid from the blood is markedly impaired in cirrhotic patients compared with that in control subjects. Almost 15 y ago we observed that the failure to metabolize methionine in cirrhosis was due to an abnormally low activity of the enzyme methionine adenosyltransferase (EC 2.5.1.6). This enzyme converts methionine, in the presence of ATP, to S-adenosyl-L-methionine (SAMe), the main biological methyl donor. Since then, it has been suspected that a deficiency in hepatic SAMe may contribute to the pathogenesis of the liver in cirrhosis. The studies reviewed here are consistent with this hypothesis

    HPV-negative Penile Intraepithelial Neoplasia (PeIN) With Basaloid Features.

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    Most human papillomavirus (HPV)-independent penile squamous cell carcinomas (PSCCs) originate from an intraepithelial precursor called differentiated penile intraepithelial neoplasia, characterized by atypia limited to the basal layer with marked superficial maturation. Previous studies in vulvar cancer, which has a similar dual etiopathogenesis, have shown that about one fifth of HPV-independent precursors are morphologically indistinguishable from high-grade squamous intraepithelial lesions (HSILs), the precursor of HPV-asssociated carcinomas. However, such lesions have not been described in PSCC. From 2000 to 2021, 55 surgical specimens of PSCC were identified. In all cases, thorough morphologic evaluation, HPV DNA detection, and p16, p53, and Ki-67 immunohistochemical (IHC) staining was performed. HPV-independent status was assigned based on both negative results for p16 IHC and HPV DNA. Thirty-six of the 55 PSCC (65%) were HPV-independent. An intraepithelial precursor was identified in 26/36 cases (72%). Five of them (19%) had basaloid features, morphologically indistinguishable from HPV-associated HSIL. The median age of the 5 patients was 74 years (range: 67 to 83 y). All 5 cases were p16 and DNA HPV-negative. Immunohistochemically, 3 cases showed an abnormal p53 pattern, and 2 showed wild-type p53 staining. The associated invasive carcinoma was basaloid in 4 cases and the usual (keratinizing) type in 1. In conclusion, a small proportion of HPV-independent PSCC may arise on adjacent intraepithelial lesions morphologically identical to HPV-associated HSIL. This unusual histologic pattern has not been previously characterized in detail in PSCC. p16 IHC is a valuable tool to identify these lesions and differentiate them from HPV-associated HSIL

    Regulation of mammalian liver methionine adenosyltransferase

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    S-adenosylmethionine (SAM) is an essential metabolite in all cells. SAM is the most important biological methyl group donor and is a precursor in the synthesis of polyamines. Methionine adenosyltransferase (MAT; EC 2.5.1.6) catalyzes the only known SAM biosynthetic reaction from methionine and ATP. In mammalian tissues, three different forms of MAT (MAT I, MAT III and MAT II) have been identified that are the product of two different genes (MAT1A and MAT2A). Although MAT2A is expressed in all mammalian tissues, the expression of MAT1A is primarily restricted to adult liver. In mammals, up to 85% of all methylation reactions and as much as 48% of methionine metabolism occurs in the liver, which indicates the important role of this organ in the regulation of blood methionine. Recent evidence indicates that not only is SAM the main biological methyl group donor and an intermediate metabolite in methionine catabolism, but it is also an intracellular control switch that regulates essential hepatic functions such as liver regeneration and differentiation as well as the sensitivity of this organ to injury. Therefore, knowledge of factors that regulate the activity of MAT I/III, the specific liver enzyme, is essential to understand how cellular SAM levels are controlled

    Simultaneous purifying selection on the ancestral MC1R allele and positive selection on the melanoma-risk allele V60L in South Europeans

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    In humans, the geographical apportionment of the coding diversity of the pigmentary locus melanocortin-1 receptor (MC1R) is, unusually, higher in Eurasians than in Africans. This atypical observation has been interpreted as the result of purifying selection due to functional constraint on MC1R in high UV-B radiation environments. By analyzing 3,142 human MC1R alleles from different regions of Spain in the context of additional haplotypic information from the 1000 Genomes (1000G) Project data, we show that purifying selection is also strong in southern Europe, but not so in northern Europe. Furthermore, we show that purifying and positive selection act simultaneously on MC1R. Thus, at least in Spain, regions at opposite ends of the incident UV-B radiation distribution show significantly different frequencies for the melanoma-risk allele V60L (a mutation also associated to red hair and fair skin and even blonde hair), with higher frequency of V60L at those regions of lower incident UV-B radiation. Besides, using the 1000G south European data, we show that the V60L haplogroup is also characterized by an extended haplotype homozygosity (EHH) pattern indicative of positive selection. We, thus, provide evidence for an adaptive value of human skin depigmentation in Europe and illustrate how an adaptive process can simultaneously help to maintain a disease-risk allele. In addition, our data support the hypothesis proposed by Jablonski and Chaplin (Human skin pigmentation as an adaptation to UVB radiation. Proc Natl Acad Sci U S A. 2010;107:8962-8968), which posits that habitation of middle latitudes involved the evolution of partially depigmented phenotypes that are still capable of suitable tanning.This works was supported by the former Spanish Ministerio de Ciencia e Innovación, project CGL2008-04066/BOS to S.A.; by the Dpt. Educacion, Universidades e Investigación of the Basque Government, project IT542-10; by program UFI11/09 by the University of the Basque Country, by "Programa de Investigacion Cientifica de la Universidad de La Laguna" (boc-a- 2010-255-7177), and by grants from the Health Institute “Carlos III” (FIS PI08/1383, FIS PI11/00623) to C.F. and co-financed by the European Regional Development Funds, “A way of making Europe” from the European Union. M.P.Y. was supported by a postdoctoral fellowship from Fundación Ramón Areces. We thank the Spanish Banco Nacional de AND (BNADN) (http://www.bancoadn.org/) for providing us with DNA samples from all over Spain. We also thank the Spanish Agencia Estatal de Meteorología (AEMET) (http://www.aemet.es/) for kindly providing us with the UV-B radiation data

    The GAPS programme at TNG XXII. The GIARPS view of the extended helium atmosphere of HD189733 b accounting for stellar activity

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    Exoplanets orbiting very close to their host star are strongly irradiated. This can lead the upper atmospheric layers to expand and evaporate into space. The metastable helium (HeI) triplet at 1083.3nm has recently been shown to be a powerful diagnostic to probe extended and escaping exoplanetary atmosphere. We perform high-resolution transmission spectroscopy of the transiting hot Jupiter HD189733b with the GIARPS (GIANO-B + HARPS-N) observing mode of the Telescopio Nazionale Galileo, taking advantage of the simultaneous optical+near infrared spectral coverage to detect HeI in the planet's extended atmosphere and to gauge the impact of stellar magnetic activity on the planetary absorption signal. Observations were performed during five transit events of HD189733b. By comparison of the in- and out-of-transit GIANO-B observations we compute high-resolution transmission spectra, on which we perform equivalent width measurements and light-curves analyses to gauge the excess in-transit absorption in the HeI triplet. We detect an absorption signal during all five transits. The mean in-transit absorption depth amounts to 0.75+/-0.03%. We detect night-to-night variations in the HeI absorption signal likely due to the transit events occurring in presence of stellar surface inhomogeneities. We evaluate the impact of stellar-activity pseudo-signals on the true planetary absorption using a comparative analysis of the HeI and the Hα\alpha lines. We interpret the time-series of the HeI absorption lines in the three nights not affected by stellar contamination -exhibiting a mean in-transit absorption depth of 0.77+/-0.04%- using a 3-d atmospheric code. Our simulations suggest that the helium layers only fill part of the Roche lobe. Observations can be explained with a thermosphere heated to \sim12000 K, expanding up to \sim1.2 planetary radii, and losing \sim1 g/s of metastable helium.Comment: 17 pages, 17 figures, accepted for publication in A&

    The regulatory subunit of PKA-I remains partially structured and undergoes β-aggregation upon thermal denaturation

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    Background: The regulatory subunit (R) of cAMP-dependent protein kinase (PKA) is a modular flexible protein that responds with large conformational changes to the binding of the effector cAMP. Considering its highly dynamic nature, the protein is rather stable. We studied the thermal denaturation of full-length RIα and a truncated RIα(92-381) that contains the tandem cyclic nucleotide binding (CNB) domains A and B. Methodology/Principal Findings: As revealed by circular dichroism (CD) and differential scanning calorimetry, both RIα proteins contain significant residual structure in the heat-denatured state. As evidenced by CD, the predominantly α-helical spectrum at 25°C with double negative peaks at 209 and 222 nm changes to a spectrum with a single negative peak at 212-216 nm, characteristic of β-structure. A similar α→β transition occurs at higher temperature in the presence of cAMP. Thioflavin T fluorescence and atomic force microscopy studies support the notion that the structural transition is associated with cross-β-intermolecular aggregation and formation of non-fibrillar oligomers. Conclusions/Significance: Thermal denaturation of RIα leads to partial loss of native packing with exposure of aggregation-prone motifs, such as the B' helices in the phosphate-binding cassettes of both CNB domains. The topology of the β-sandwiches in these domains favors inter-molecular β-aggregation, which is suppressed in the ligand-bound states of RIα under physiological conditions. Moreover, our results reveal that the CNB domains persist as structural cores through heat-denaturation. © 2011 Dao et al
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