134 research outputs found

    In memorian / Nota necrológica Dr. Martín H. Iriondo (1942-2020)

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    Texto en homenaje al Dr. Martin Iriondo.

    Palaeohydrology from the Northern Salado River, a lower Parana river tributary (Argentina)

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    Palaeofloods and drainage palaeostage can be approached from sedimentological, stratigraphical, geomorphological, geodetic, and geophysical information. This allows us to supply pre-instrumental and historical data and to assess a particular flood-prone area. It has been proved that the study of Late Holocene fluvial sediments is valuable source to estimate 1 × 102-1x103yr. scale occurrence and long-term recurrence of maximum events. The geological evidence of palaeofloods in lowlands in Central Argentina may reveal higher discharges likely occurred in the near past. In this work, we attempt to identify sedimentological evidence of past floods in Late Holocene sediments from the northern Salado River (NSR), an important tributary of the lower Paraná River basin (Chaco-Pampean plain region). In the yr. 2003, the lower reaches of the NSR recorded an extreme flood event that provoked a disaster in Santa Fe, a city of 500,000 inhabitants located at the river mouth. Considering the importance of this event, we developed a geomorphometry methodology for discriminating different levels of fluvial terraces and flood indicators in a representative area of the NSR, using multi-scale resolution Digital Elevation Model (DEM) data. Descriptions of flood-associated fluvial landforms and sedimentological stratigraphic attributes were performed in the field. High-resolution geodetic information and digital optical images were obtained from UAV photogrammetry. Ground Penetrating Radar (GPR) cross-sections were achieved and addressed to detect extreme flood evidence. A geomorphometric routine was applied to simulate the extreme flood scenarios, based on the data obtained from the field. The map resulting from the simulation was compared to satellite images recorded in the yr. 2003 extreme flood. A series of slackwater deposits and other palaeostage indicators (SWD-PSI) showed elevations higher than those reached over the yr. 2003 extraordinary flood (instrumentally recorded) and in the yr. 1914 historic flood event. The geomorphometric simulation of a flood event, calibrated from these diagnostic landforms, allowed us to extend the flood-prone area beyond the boundaries of the current active floodplain and channel. The integrative methodology enabled the mapping of areas potentially prone to flooding. The estimations of the discharges associated to the inferred palaeofloods could be 50–80% larger than the maximum events historically documented and instrumentally measured.Fil: Pedersen, Oscar Ariel. Provincia de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Universidad Autónoma de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción; ArgentinaFil: Brunetto, Ernesto. Provincia de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Universidad Autónoma de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción; ArgentinaFil: Krohling, Daniela Mariel Ines. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Litoral; ArgentinaFil: Thalmeier, Maria Belen. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Autónoma de Entre Ríos; ArgentinaFil: Zalazar, Maria Cecilia. Universidad Autónoma de Entre Ríos; Argentin

    PALAEOSURFACE ANALYSIS ON THE CRETACEOUS BASALTIC PLATEAU ON THE UPPER RÍO URUGUAY BASIN (NE ARGENTINA AND SOUTHERN BRAZIL)

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    Os primeiros resultados de uma pesquisa geomorfológica nos platôs basálticos cretáceos da parte superior da bacia do Rio Uruguai (NE Argentina e sudeste do Brasil) são apresentados. Modelos digitais de elevação SRTM e dados de campo foram utilizados nas análises morfométricas. A geração de curvas hipsométricas em cinco tributários representativos da bacia do rio Uruguai e, em uma pequena bacia ligada ao rio Paraná, permitiram identificar, classificar e mapear as principais paleosuperfícies cenozóicas do platô. Outros parâmetros morfométricos, tais como perfis longitudinais e linhas de isobases, foram produzidos também para delimitar tais superfícies. A identificação de paleosuperfícies foi estendida até o limite das bacias dos rios Paraná e Uruguai a fim de identificar remanescentes de superfícies e correlacioná-las com aquelas descritas previamente no sul do Brasil. As paleosuperfícies 1 e 1b neste trabalho são equivalentes à “Superfície Sul-Americana” de King. Ambas as superfícies 1 e 1b (> 883m s.n.m.) estão bem representadas na sub bacia do rio Pelotas. Se a bacia superior do Rio Uruguai corresponde ao segmento mais baixo da paleosuperfície, um nível de base suposto é estimado ao redor dos 840 m s.n.m. A superfície remanescente de maior cota na área nordeste da Província das Missões (Argentina) é interpretada como paleosuperfície 2b (676-883 m s.n.m.). A “Paleosuperfície Velhas”, definida por King, correlaciona-se com a Paleosuperfície 2, aquela que nas Missões compreende uma divisória plana entre as bacias dos rios Paraná e Uruguai (436 – 676 m s.n.m). Esta superfície é ampla na bacia do rio Uruguai no Brasil e está representada por uma paisagem de colinas bem arredondadas com encostas suaves. As superfícies identificadas como de menor cota, 3 e 4, correspondem à superfície Apóstoles (Ca. 200 m s.n.m.), aquelas que haviam sido geradas durante o ciclo Paraguaçu de King, representada pela incisão de vales. Palavras chave: análise morfométrica; paleosuperfícies; meseta basáltica; bacia superior do rio Uruguai, América do Sul

    VNS in drug resistant epilepsy: preliminary report on a small group of patients

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    <p>Abstract</p> <p>Background</p> <p>In 1997 Vagus Nerve Stimulation (VNS) received approval from the US Food and Drug Administration (FDA) as an adjunctive therapy in the treatment of medically intractable partial epilepsy in people aged 12 years and older who are ineligible for resective epilepsy surgery. Although the exact mechanisms of action are unknown, the use of VNS with children has increased, including those younger than 12 years of age, or those with generalized epilepsy.</p> <p>Methods</p> <p>We describe the outcome for the first group of nine patients, aged 8-28 years, who had pharmaco-resistant epilepsy and were treated with VNS. During the follow up, we gradually and slowly increased the parameters of the stimulation in order to assess the efficacy of VNS even at parameters which would usually be considered "non-therapeutic", along with possible side effects and changes in quality of life.</p> <p>Results</p> <p>At the last follow, up 1 patient was "seizures free", 3 were "very good responders", 3 were "good responders" and 2 were "non responders". We obtained an initial seizure reduction with low stimulation parameters, the highest current reached being 2.00 mA. This observation supports the possibility that, for younger patients, lower stimulation intensities than those commonly used in clinical practice for adults can be therapeutic. We also wanted to underline the reduction in seizure frequency (~91,7%) and the reduction in seizure duration (> 50%) in the patients affected by drug-resistant absence epilepsy. Adverse effects were mild, tolerable and, in most of cases, easily resolved by adjusting the stimulation parameters. Hoarseness of voice was the most frequent side effect. The improvements in the quality of life are relevant and seem to be independent of the VNS effect in controlling seizures.</p> <p>Conclusions</p> <p>Our small experience seems to confirm the efficacy and safety of VNS in drug resistant partial and generalized epilepsy in developing age groups.</p

    Influence of GRPR and BDNF/TrkB signaling on the viability of breast and gynecologic cancer cells

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    Neuropeptide and neurotrophin receptors are increasingly important molecular targets in cancer. Scientific findings indicate that compounds blocking gastrin-releasing peptide receptors (GRPR) or tropomyosin receptor kinase (Trk) receptors are likely to have antiproliferative activities against cancer cells. The present study aimed to demonstrate that, in contrast to previous findings, GRPR activation reduces, whereas its blockade increases the viability of breast, ovarian and cervical cancer cell lines. However, consistent with previous studies, Trk inhibition was demonstrated to reduce the viability of these cells. MCF-7 (breast), OVCAR-3 (ovarian) and HeLa (cervical) human cancer cell lines were treated with GRP, the GRPR antagonists RC-3095 and RC-3940-II, brain-derived neurotrophic factor (BDNF) and the Trk antagonist K252α. Cell viability was measured by the MTT assay. Expression of GRPR and BDNF was confirmed with reverse transcription‑polymerase chain reaction (RT-PCR). GRP reduced, whereas RC-3940-II enhanced the viability of the three cell lines. Treatment with K252α inhibited the viability of the cell lines, while BDNF increased the viability of OVCAR-3 cells. The results supported the hypothesis that GRPR and BDNF/TrkB signaling regulates cancer cell viability. Most importantly, these findings are the first to demonstrate that GRPR blockade can stimulate, rather than inhibits the viability of breast and gynecologic cancer cell lines

    An Unexpected Case of Opisthorchis felineus Infection Revealed during Liver Transplantation

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    A man with hepatitis B infection was admitted to Pisa University Hospital for hepatological evaluation, which revealed multiple cystic lesions and suggested a cirrhotic evolution. Treatment with Entecavir 0.5 mg/day was started, resulting in rapid viral load suppression and alanine aminotransferase normalization. After 10 years, imaging documented a single nodule of hepatocellular carcinoma (HCC), and a robot-assisted nodule resection was performed. One year later, HCC recurrence prompted orthotopic liver transplantation, during which the patient died because of the sudden rupture of the donor's organ and rapid multiorgan deterioration before retransplantation. During post-mortem liver examination, adult worms were evidenced within large biliary ducts, suggesting infection with Opisthorchis or Clonorchis spp. flukes. Sequencing of the ITS2 locus, following PCR amplification of DNA extracted from liver tissue, revealed 100% identity with the reference sequence of O. felineus. Infection of the patient with O. felineus was confirmed by the presence of specific IgG detected by ELISA in the patient's sera. Two major alkaline phosphatase serum levels peaks observed during the first two years of antiviral therapy support the hypothesis that O. felineus infection worsened liver function. This case report highlights the importance of a very careful screening of parasitic infections in solid organ transplantation candidates

    Association of the mtDNA m.4171C>A/MT-ND1 mutation with both optic neuropathy and bilateral brainstem lesions

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    Background: An increasing number of mitochondrial DNA (mtDNA) mutations, mainly in complex I genes, have been associated with variably overlapping phenotypes of Leber’s hereditary optic neuropathy (LHON), mitochondrial encephalomyopathy with stroke-like episodes (MELAS) and Leigh syndrome (LS). We here describe the first case in which the m.4171C>A/MT-ND1 mutation, previously reported only in association with LHON, leads also to a Leigh-like phenotype. Case presentation: A 16-year-old male suffered subacute visual loss and recurrent vomiting and vertigo associated with bilateral brainstem lesions affecting the vestibular nuclei. His mother and one sister also presented subacute visual loss compatible with LHON. Sequencing of the entire mtDNA revealed the homoplasmic m.4171C>A/MT-ND1 mutation, previously associated with pure LHON, on a haplogroup H background. Three additional non-synonymous homoplasmic transitions affecting ND2 (m.4705T>C/MT-ND2 and m.5263C>T/MT-ND2) and ND6 (m.14180T>C/MT-ND6) subunits, well recognized as polymorphisms in other mtDNA haplogroups but never found on the haplogroup H background, were also present. Conclusion: This case widens the phenotypic expression of the rare m.4171C>A/MT-ND1 LHON mutation, which may also lead to Leigh-like brainstem lesions, and indicates that the co-occurrence of other ND non-synonymous variants, found outside of their usual mtDNA backgrounds, may have increased the pathogenic potential of the primary LHON mutation
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