236 research outputs found

    Anaerobic 4-hydroxyproline utilization: Discovery of a new glycyl radical enzyme in the human gut microbiome uncovers a widespread microbial metabolic activity.

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    The discovery of enzymes responsible for previously unappreciated microbial metabolic pathways furthers our understanding of host-microbe and microbe-microbe interactions. We recently identified and characterized a new gut microbial glycyl radical enzyme (GRE) responsible for anaerobic metabolism of trans-4-hydroxy-l-proline (Hyp). Hyp dehydratase (HypD) catalyzes the removal of water from Hyp to generate Δ1-pyrroline-5-carboxylate (P5C). This enzyme is encoded in the genomes of a diverse set of gut anaerobes and is prevalent and abundant in healthy human stool metagenomes. Here, we discuss the roles HypD may play in different microbial metabolic pathways as well as the potential implications of this activity for colonization resistance and pathogenesis within the human gut. Finally, we present evidence of anaerobic Hyp metabolism in sediments through enrichment culturing of Hyp-degrading bacteria, highlighting the wide distribution of this pathway in anoxic environments beyond the human gut

    Observational study of patients in Spain with amyotrophic lateral sclerosis: correlations between clinical status, quality of life, and dignity

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    Background: Amyotrophic lateral sclerosis (ALS) is an incurable neurodegenerative disease that dramatically affects patients' quality of life (QoL) and dignity of life (DoL). We aimed to study the impact of ALS on QoL and DoL and how these evolve throughout the duration of the disease. Methods: First, we performed an observational, descriptive study of 43 patients with ALS recruited from the ALS unit at our center and compared them with 20 healthy age- and sex-matched controls. Second, we performed a prospective cohort study, following up 23 patients with ALS over 3 months. All participants completed questionnaires about their functional status, QoL, and DoL. Results: QoL and DoL were significantly worse in the ALS group than in controls (both p < 0.001). During the three-month follow-up in the ALS cohort, statistically significant declines were observed in clinical status and QoL. For clinical status, median scores on the ALS Functional Rating scale changed from 30.95 points at baseline to 27.24 points after 3 months (p = 0.0003). For QoL, median scores on the ALS Assessment Questionnaire changed from 124.19 points at baseline to 131.81 at 3 months (p = 0.0062). However, no significant differences were found between the DoL scores at baseline (48. 14 points) and 3 months (45 points) (p-value = 0.12). Conclusions: ALS is a neurodegenerative disease that affects QoL and DoL alike. We found that clinical status and QoL both deteriorated in patients with ALS as the disease progressed, but that DoL was preserved. However, our findings are limited by small sample sizes. The preservation of DoL may be due to multiple factors, including the therapies provided by the ALS unit. These findings suggest that alongside QoL, DoL may be an important target in the management and care of ALS patients

    Leaf Traits Drive Plant Diversity Effects On Litter Decomposition And FPOM Production In Streams

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    Biodiversity loss in riparian forests has the potential to alter rates of leaf litter decomposition in stream ecosystems. However, studies have reported the full range of positive, negative and no effects of plant diversity loss on decomposition, and there is currently no explanation for such inconsistent results. Furthermore, it is uncertain whether plant diversity loss affects other ecological processes related to decomposition, such as fine particulate organic matter production or detritivore growth, which precludes a thorough understanding of how detrital stream food webs are impacted by plant diversity loss. We used a microcosm experiment to examine the effects of plant diversity loss on litter decomposition, fine particulate organic matter production, and growth of a dominant leaf-shredding detritivore, using litter mixtures varying in species composition. We hypothesized that plant diversity loss would decrease the rates of all studied processes, but such effects would depend on the leaf traits present in litter mixtures (both their average values and their variability). Our findings partly supported our hypotheses, showing that plant diversity loss had a consistently negative effect on litter decomposition and fine particulate organic matter production (but not on detritivore growth) across litter mixtures, which was mediated by detritivores. Importantly, the magnitude of the diversity effect and the relative importance of different mechanisms underlying this effect (i.e., complementarity vs. selection) varied depending on the species composition of litter mixtures, mainly because of differences in litter nutritional quality and trait variability. Complementarity was prevalent but varied in size, with positive selection effects also occurring in some mixtures. Our results support the notion that loss of riparian plant species is detrimental to key stream ecosystem processes that drive detrital food webs, but that the magnitude of such effects largely depends on the the order of species loss.This study was funded by the ‘BIOFUNCTION’ project (CGL2014-52779-P) from the Spanish Ministry of Economy and Competitiveness (MINECO) and FEDER to LB and JPo, Basque Government funds (IT302-16) to JPo, and Ikerbasque start-up funds to LB. NLR and AM were supported by a predoctoral fellowship from the Basque Government and a postdoctoral contract from the University of the Basque Country, respectively. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

    Temperature Sensitivity of Microbial Litter Decomposition in Freshwaters: Role of Leaf Litter Quality and Environmental Characteristics

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    Ongoing global warming is expected to alter temperature-dependent processes. Nevertheless, how co-occurring local drivers will influence temperature sensitivity of plant litter decomposition in lotic ecosystems remains uncertain. Here, we examined the temperature sensitivity of microbial-mediated decomposition, microbial respiration, fungal biomass and leaf nutrients of two plant species varying in litter quality. We also assessed whether the type of microbial community and stream water characteristics influence such responses to temperature. We incubated alder (Alnus glutinosa) and eucalypt (Eucalyptus globulus) litter discs in three streams differing in autumn–winter water temperature (range 4.6–8.9 °C). Simultaneously, in laboratory microcosms, litter discs microbially conditioned in these streams were incubated at 5, 10 and 15 °C with water from the conditioning stream and with a water control from an additional stream. Both in the field and in the laboratory, higher temperatures enhanced litter decomposition rates, except for eucalypt in the field. Leaf quality modified the response of decomposition to temperature in the field, with eucalypt leaf litter showing a lower increase, whereas it did not in the laboratory. The origin of microbial community only affected the decomposition rates in the laboratory, but it did not modify the response to temperature. Water quality only defined the phosphorus content of the leaf litter or the fungal biomass, but it did not modify the response to temperature. Our results suggest that the acceleration in decomposition by global warming will be shaped by local factors, mainly by leaf litter quality, in headwater streams.Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. This research was financed by the Ministry of Science and Innovation of the Spanish Government (CGL2010-22129-C04-01). S. Monroy was supported by a predoctoral grant by the Spanish Ministry of Economy and Competitiveness (BES-2012–060743) and a postdoctoral grant from the University of the Basque Country (DOKBERRI 2018 I)

    Resource preference of two stream detritivores in the laboratory largely differs from the supply of detritus below eucalypt plantations

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    Detritivores are pivotal in forest streams as they process detritus and promote secondary production. Many studies have addressed the preference of freshwater detritivores towards materials of differing quality. Nevertheless, few studies compare the resource preferences in the laboratory with the availability in the field. In the present study, feeding preferences of two stream detritivores (the caddisfly Sericostoma pyrenaicum and the amphipod Echinogammarus tarragonensis), over three native leaf species (alder, chestnut and oak) and an exotic species (eucalypt) were quantified in the laboratory. Preference for eucalypt leaves conditioned for 1, 2 and 3 weeks was also described. We then contrasted the preference patterns in the laboratory feeding experiments with a 15-month-long benthic standing stock time series of a stream below a native deciduous forest and another below a eucalypt plantation. Both detritivores preferred consuming alder leaves and more conditioned eucalypt leaves, although the amphipod was more selective than the caddisfly. The consumption preference in the laboratory was unmatched by the availability in the field, especially under eucalypt plantations and for the amphipod. Our results show that the strength of the preference for high-quality resources can differ among different taxa, which can modulate their response to land use changes.Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. This study was funded by the Spanish Dirección General de Enseñanza Superior e Investigación Científica (Project DGESIC PB98-0151) and finanacial support in terms of a predoctoral Grant to A. Otermin from Basque Government

    Estudio radiológico sobre prevalencia de displasia de cadera en pacientes caninos del Hospital Veterinario de la Universidad de Zaragoza en relación con la raza, sexo, edad y peso.

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    La displasia de cadera es la enfermedad osteoarticular más frecuente en perros y posee gran importancia en la clínica de pequeños animales. Aunque la principal causa que determina su aparición es el factor genético, ha quedado constatado científicamente la existencia de factores predisponentes (peso, edad, sexo, raza) que pueden incidir sobre el desarrollo de la enfermedad o agravar los síntomas clínicos. Para valorar la prevalencia de displasia y la relación entre dicha enfermedad y los factores predisponentes, se lleva a cabo un estudio retrospectivo en el HVUZ con 133 radiografías de cadera de animales que han acudido al hospital con sintomatología ortopédica. Tras la obtención de la prevalencia de displasia de cadera y la prevalencia de los distintos grados (B,C,D y E) se relacionan ambas prevalencias con la raza, el sexo, la edad y tamaño de los animales. En el estudio se obtuvo que la prevalencia de displasia era de 61,7%. En aquellos individuos diagnosticados como displásicos se determinó un predominio de grado C (21’1%). Al relacionar los distintos factores predisponentes con prevalencia y grado de displasia, se encontró relación significativa entre grados severos de displasia (D,E) y pertenencia a una raza citada en la bibliografía como predisponente de enfermedad, mientras que en las razas no contempladas en dicho grupo predominaron los grados leve y moderado de displasia (B,C). Igualmente el tamaño de los individuos resultó tener relación significativa con el grado de enfermedad. Por el contrario pese a que los resultados descriptivos muestran tendencias de interés, no se ha encontrado relación estadística significativa al enfrentar la variable displasia con la raza, el sexo, la edad o el tamaño de los animales. De la misma manera, no se ha encontrado relación significativa entre el sexo o la edad de los animales estudiados con el grado de displasia

    Comparison of different sources of platelet-rich plasma as treatment option for infertility-causing endometrial pathologies

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    Objective. To study the effect of human plasma from different sources such as umbilical cord blood and adult blood platelet-rich plasma (PRP) on the regeneration of endometrial damage. Design. Composition analysis, in vitro approaches and a pre-clinical murine model using plasma to promote endometrial regeneration. Setting. Hospital and university laboratories. Patients/Animals. Adult plasma from 4 Atrophy patients and one fertile woman, commercial umbilical cord plasma and uterine-damaged NOD/SCID mice model were used. Intervention(s). Endometrial stromal cells from primary culture and an endometrial stem cell line were cultured in vitro and uterine-damaged NOD/SCID mice were treated with plasma samples from several origins. Main Outcome Measure(s). All plasma samples contain molecules with a high potential for regeneration (SCF, PDGFBB, THBS1, VWF). Furthermore, the highest increase in in vitro proliferation and migration rate was found when endometrial stromal cells were treated with umbilical cord plasma, adult PRP also revealed a significant increment. In the mouse model, a higher expression of Ki67 and Hoxa10 in the endometrium was detected after applying adult PRP and the proteomic analysis revealed a specific protein expression profile depending on the treatment. The damaged uterine tissue showed more pro22 regenerative markers after applying umbilical cord plasma (Stat5a, Uba3, Thy1) in comparison to the other treatments (non-activated umbilical cord plasma, activated adult PRP and not treatment). Conclusion. Human PRP possesses regeneration properties usable for endometrial pathologies. Besides that, these regenerative effects seem to be more apparent when the source of obtaining is umbilical cord blood

    Diminished neurogenic femoral artery vasoconstrictor response in a Zucker obese rat model: differential regulation of NOS and COX derivatives

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    Objective: Peripheral arterial disease is one of the macrovascular complications of type 2 diabetes mellitus. This study addresses femoral artery regulation in a prediabetic model of obese Zucker rats (OZR) by examining cross-talk between endothelial and neural factors. Methods and Results: Arterial preparations from lean (LZR) and OZR were subjected to electrical field stimulation (EFS) on basal tone. Nitric oxide synthase (NOS) and cyclooxygenase (COX) isoform expression patterns were determined by immunohistochemical labelling and Western blotting. Results indicate significantly reduced noradrenergic contractions in preparations from OZR compared with those of LZR. Functional inhibition of endothelial NOS (eNOS) indicated a predominant role of this isoform in LZR and its modified activity in OZR. Neural (nNOS) and inducible NOS (iNOS) were activated and their expression was higher in femoral arteries from OZR. Neurotransmission modulated by largeconductance Ca2+-activated (BKCa) or voltage-dependent (KV) K+ channels did not seem compromised in the obese animals. Endothelial COX-1 and COX-2 were expressed in LZR and an additional adventitial location of COX-2 was also observed in OZR, explaining the higher COX-2 protein levels detected in this group. Prostanoids derived from both isoforms helped maintain vasoconstriction in LZR while in OZR only COX-2 was active. Superoxide anion inhibition reduced contractions in endothelium-intact arteries from OZR. Conclusions: Endothelial dysfunction led to reduced neurogenic vasoconstriction in femoral arteries from OZR. In a setting of obesity, NO-dependent nNOS and iNOS dilation activity could be an alternative mechanism to offset COX-2- and reactive oxygen species-mediated vasoconstriction, along with impaired endothelial NO relaxation

    Land use drives detritivore size structure and decomposition through shifts in resource quality and quantity

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    Land use change and nutrient pollution are two pervasive stressors that can modify carbon cycling, as they influence the inputs and the transformation of detritus. Understanding their impact on stream food webs and on diversity is particularly pressing, as streams are largely fuelled by detrital material received from the adjacent riparian environment. Here we assess how a switch from native deciduous forest to Eucalyptus plantations and nutrient enrichment alter the size distribution of stream detritivore communities and decomposition rates of detritus. As expected, more detritus resulted in higher size-independent, or overall, abundance (i.e. higher intercept of size spectra). This change in overall abundance was mainly driven by a change of the relative contribution of large taxa (Amphipoda and Trichoptera), which changed from an average relative abundance of 55.5 to 77.2 % between the sites compared for resource quantity differences in our study. In contrast, detritus quality modified the relative abundance of large vs small individuals (i.e. size spectra slopes), with shallow slopes of size spectra (proportionately more large individuals) associated with sites with nutrient-richer waters and steeper slopes (proportionately fewer large individuals) associated with sites draining Eucalyptus plantations. Decomposition rates of alder leaves due to macroinvertebrates increased from 0.0003 to 0.0142 when relative contribution of large organisms increased (modelled slopes of size spectra: −1.00 and − 0.33, respectively), highlighting the importance of large sized individuals for ecosystem functioning. Our study reveals that land use change and nutrient pollution can greatly impair the transfer of energy through the detrital or ‘brown’ food web by means of intra- and inter-specific responses to quality and quantity of the detritus. These responses enable linking land use change and nutrient pollution to ecosystem productivity and carbon cycling.This work was carried out with financial support from the EU Commission within the RivFunction project (contract EVK1-CT-2001-00088). AL acknowledges the financial support by the mobility program Ikermugikortasuna-2019 of the Basque Government

    Nuclear data sensitivity and uncertainty assessment of sodium voiding reactivity coefficients of an ASTRID-like Sodium Fast Reactor

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    The EU 7th Framework ESNII+ project was launched in 2013 with the strategic orientation of preparing ESNII for Horizon 2020. ESNII stands for the European Industrial Initiative on Nuclear Energy, created by the European Commission in 2010 to promote the development of a new generation of nuclear systems in order to provide a sustainable solution to cope with Europe’s growing energy needs while meeting the greenhouse gas emissions reduction target. The designs selected by the ESNII+ project are technological demonstrators of Generation-IV systems. The prototype for the sodium cooled fast reactor technology is ASTRID (standing for Advanced Sodium Technological Reactor for Industrial Demonstration), which building phase is foreseen to be initiated in 2019. The ASTRID core has a peculiar design which was created in order to tackle the main neutronic challenge of sodium cooled fast reactors: the inherent overall positive reactivity feedback in case of sodium boiling occurring in the core. Indeed, the core is claimed by its designers to have an overall negative reactivity feedback in this scenario. This feature was demonstrated for an ASTRID-like core within the ESNII+ framework studies performed by nine European institutions. In order to shift the paradigm towards best-estimate plus uncertainties, the nuclear data sensitivity analysis and uncertainty propagation on reactivity coefficients has to be carried out. The goal of this work is to assess the impact of nuclear data uncertainties on sodium boiling reactivity feedback coefficients in order to get a more complete picture of the actual safety margins of the ASTRID low void-core design. The nuclear data sensitivity analysis is performed in parallel using SCALE-TSUNAMI 3D and the newly developed GPT SERPENT 2 module. A comparison is carried out between both methodologies. Uncertainty on the sodium boiling reactivity feedbacks is then calculated using TSAR module of SCALE and the necessary safety margins conclusions are drawn
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