Ipsilesional Hippocampal GABA Is Elevated and Correlates With Cognitive Impairment and Maladaptive Neurogenesis After Cortical Stroke in Mice.

BACKGROUND: Cognitive dysfunction is a frequent stroke sequela, but its pathogenesis and treatment remain unresolved. Involvement of aberrant hippocampal neurogenesis and maladaptive circuitry remodeling has been proposed, but their mechanisms are unknown. Our aim was to evaluate potential underlying molecular/cellular events implicated. METHODS: Stroke was induced by permanent occlusion of the middle cerebral artery occlusion in 2-month-old C57BL/6 male mice. Hippocampal metabolites/neurotransmitters were analyzed longitudinally by in vivo magnetic resonance spectroscopy. Cognitive function was evaluated with the contextual fear conditioning test. Microglia, astrocytes, neuroblasts, interneurons, γ-aminobutyric acid (GABA), and c-fos were analyzed by immunofluorescence. RESULTS: Approximately 50% of mice exhibited progressive post-middle cerebral artery occlusion cognitive impairment. Notably, immature hippocampal neurons in the impaired group displayed more severe aberrant phenotypes than those from the nonimpaired group. Using magnetic resonance spectroscopy, significant bilateral changes in hippocampal metabolites, such as myo-inositol or N-acetylaspartic acid, were found that correlated, respectively, with numbers of glia and immature neuroblasts in the ischemic group. Importantly, some metabolites were specifically altered in the ipsilateral hippocampus suggesting its involvement in aberrant hippocampal neurogenesis and remodeling processes. Specifically, middle cerebral artery occlusion animals with higher hippocampal GABA levels displayed worse cognitive outcome. Implication of GABA in this setting was supported by the amelioration of ischemia-induced memory deficits and aberrant hippocampal neurogenesis after blocking pharmacologically GABAergic neurotransmission, an intervention which was ineffective when neurogenesis was inhibited. These data suggest that GABA exerts its detrimental effect, at least partly, by affecting morphology and integration of newborn neurons into the hippocampal circuits. CONCLUSIONS: Hippocampal GABAergic neurotransmission could be considered a novel diagnostic and therapeutic target for poststroke cognitive impairment.

Comparison of 2 medium cutoff dialyzers versus on-line hemodiafiltration regarding depurative ability and albumin loss: An uncontrolled clinical research.

BACKGROUND: Hemodialysis (HD) techniques that best remove molecules in the middle to high molecular weight range are on-line hemodiafiltration (OL-HDF) and HD with medium cut-off (MCO) membranes. The aim of this study was to compare efficacy and safety of OL-HDF with FxCordiax HDF 800™, with HD with 2 MCO dialyzers: Theranova 500® and the new Elisio 21HX™ dialyzer. METHODS: Fourteen patients following treatment with OL-HDF using FxCordiax HDF 800™ were randomized to receive a consecutive 1-week HD treatment with Theranova 500® and Elisio 21HX™.The reduction rate (RR) of differently sized molecules was compared, as well as the variation rate in molecules smaller than 1000, detected by nuclear magnetic resonance based chemometrics (metabolomics). Albumin loss in dialysate was quantified. RESULTS: Lower RRs were found for molecules around 20 000 with Elisio 21HX™ compared to OL- HDF (RR prolactin 58.5% versus 66.7%, p = 0.034; RR Kappa light chain 63.1% versus 71.8%, p = 0.010). Albumin loss per session was higher with Theranova 500® than with OL-HDF and with Elisio 21HX™ (2249.9 ± 714.1 mg, 815.2 ± 474.0 mg, 442.9 ± 135.9 mg, p < 0.001, respectively). Metabolomic studies suggested, by semi-quantitative analysis, a greater depurative capacity of OL-HDF, followed by Elisio 21HX™, and then Theranova 500®. CONCLUSIONS: In this study, HD with Theranova 500® has proven to be very similar in efficacy to OL-HDF, although with a significantly higher albumin loss. HD with Elisio 21HX™ resulted in lower removal of molecules around 20 000 compared to OL-HDF, with no significant difference compared to Theranova 500®, and with less albumin loss than Theranova 500®.

The effect of dispersal on asymptotic total population size in discrete- and continuous-time two-patch models.

Many populations occupy spatially fragmented landscapes. How dispersal affects the asymptotic total population size is a key question for conservation management and the design of ecological corridors. Here, we provide a comprehensive overview of two-patch models with symmetric dispersal and two standard density-dependent population growth functions, one in discrete and one in continuous time. A complete analysis of the discrete-time model reveals four response scenarios of the asymptotic total population size to increasing dispersal rate: (1) monotonically beneficial, (2) unimodally beneficial, (3) beneficial turning detrimental, and (4) monotonically detrimental. The same response scenarios exist for the continuous-time model, and we show that the parameter conditions are analogous between the discrete- and continuous-time setting. A detailed biological interpretation offers insight into the mechanisms underlying the response scenarios that thus improve our general understanding how potential conservation efforts affect population size.

[Public Resistance to Vaccination During Epidemics: The Example of COVID-19Resistência da população à vacinação em tempos de epidemias: sobre a COVID-19]. / Resistencia de la población hacia la vacunación en época de epidemias: a propósito de la COVID-19.

Objective: This article presents the findings of a review of the literature on public resistance to vaccines and the main factors that have influenced their decisions about immunoprevention, with a focus on the COVID-19 pandemic. Methods: We searched the literature using the terms DeCs/MeSH, anti-vaccination movement, vaccination refusal, epidemics, COVID-19, and impacts on health, using the Boolean operators OR and AND in Google Scholar, Medline, Lilacs, and Ibecs. Documents from official sources were also considered. Results: Throughout history, since vaccination began, people have had controversial perceptions of the procedure: some accept what the health authorities recommend, and others allege hidden intentions behind immunization. The COVID-19 vaccine against SARS-CoV-2 has been no exception. Conclusions: Vaccination has been one of the greatest scientific achievements in public health. However, despite its benefits, it has raised fear, uncertainty, and suspicion in the population. For this reason, it is important to increase health education actions in the population-with clear, concise, understandable information that is based on reliable and truthful sources-in order to reduce resistance to vaccination and address preventable diseases.

Objetivo: Este artigo busca apresentar os achados de uma revisão da literatura sobre a resistência da população às vacinas e os principais motivos que influenciaram suas decisões em relação à imunoprevenção, com foco na pandemia de COVID-19. Métodos: Foi realizada uma busca na literatura utilizando os termos DeCs/MeSH anti-vaccination movement, vaccination refusal, epidemics, COVID-19 e impacts on health, relacionados entre si pelos operadores booleanos OR e AND, no Google Scholar, MEDLINE, LILACS e IBECS. Documentos de fontes oficiais também foram levados em consideração. Resultados: Ao longo da história, desde o início da vacinação, a percepção das pessoas em relação a esse procedimento foi controversa. Há quem aceite o que as autoridades de saúde recomendam e quem alegue intenções ocultas por trás da imunização. A vacina contra o SARS-CoV-2, que causa a COVID-19, não foi exceção. Conclusões: A vacinação tem sido uma das maiores conquistas científicas em termos de saúde pública ­ um avanço que, apesar de seus benefícios, tem causado medo, incerteza e desconfiança na população. Por isso, é importante aumentar as ações de educação em saúde para a população, com informações claras, concisas e compreensíveis, baseadas em fontes confiáveis e verídicas, a fim de diminuir a resistência à vacinação e evitar doenças preveníveis.

Changing Temperature Conditions during Somatic Embryo Maturation Result in Pinus pinaster Plants with Altered Response to Heat Stress.

Under the global warming scenario, obtaining plant material with improved tolerance to abiotic stresses is a challenge for afforestation programs. In this work, maritime pine (Pinus pinaster Aiton) plants were produced from somatic embryos matured at different temperatures (18, 23, or 28 °C, named after M18, M23, and M28, respectively) and after 2 years in the greenhouse a heat stress treatment (45 °C for 3 h/day for 10 days) was applied. Temperature variation during embryo development resulted in altered phenotypes (leaf histology, proline content, photosynthetic rates, and hormone profile) before and after stress. The thickness of chlorenchyma was initially larger in M28 plants, but was significantly reduced after heat stress, while increased in M18 plants. Irrespective of their origin, when these plants were subjected to a heat treatment, relative water content (RWC) and photosynthetic carbon assimilation rates were not significantly affected, although M18 plants increased net photosynthesis rate after 10 days recovery (tR). M18 plants showed proline contents that increased dramatically (2.4-fold) when subjected to heat stress, while proline contents remained unaffected in M23 and M28 plants. Heat stress significantly increased abscisic acid (ABA) content in the needles of maritime pine plants (1.4-, 3.6- and 1.9-fold in M18, M23, and M28 plants, respectively), while indole-3-acetic acid content only increased in needles from M23 plants. After the heat treatment, the total cytokinin contents of needles decreased significantly, particularly in M18 and M28 plants, although levels of active forms (cytokinin bases) did not change in M18 plants. In conclusion, our results suggest that maturation of maritime pine somatic embryos at lower temperature resulted in plants with better performance when subjected to subsequent high temperature stress, as demonstrated by faster and higher proline increase, lower increases in ABA levels, no reduction in active cytokinin, and a better net photosynthesis rate recovery.

Hard tick species (Acari: Ixodidae) and infestation in two livestock agroecosystems from Antioquia, Colombia.

Tick infestation affects about 80% of livestock globally while transmitting various pathogens causing high economic losses. This study aimed to determine the degree of tick infestation in two regions, North and Middle Magdalena in Antioquia, Colombia, to identify the ixodid tick species found and the associated risk factors. A cross-sectional study was carried out in 48 farms distributed in six municipalities of Antioquia. Two paddocks and eight bovines per farm were evaluated to estimate tick infestation (adults, nymphs, and larvae). Tick species were identified through a morphological and molecular analysis based on partial sequences of data obtained from DNA molecular markers, two mitochondrial (16S rRNA and COI), and one genomic DNA gene (18S rRNA). A multivariate Poisson regression model was applied to estimate the associated risk factors with ticks in cattle. Rhipicephalus microplus, Amblyomma patinoi and Dermacentor nitens were present in the livestock agroecosystems in the Middle Magdalena region; the highest incidence of tick infestation in cows and paddocks was reported in the municipality of Puerto Triunfo. The livestock agroecosystems in Middle Magdalena were characterized by a higher presence of adult R. microplus in cattle. Larval infestation of R. microplus, followed by D. nitens, was also found in paddocks. The multivariate analysis showed that the origin of cattle was the main risk factor associated with the presence of ticks (i.e., when cattle came from outside the farm). Cattle movement between farms in Middle Magdalena can contribute to the spread of ticks in this region.

Glutaminase isoforms expression switches microRNA levels and oxidative status in glioblastoma cells.

BACKGROUND: Glutaminase isoenzymes GLS and GLS2 play apparently opposing roles in cancer: GLS acts as an oncoprotein, while GLS2 (GAB isoform) has context specific tumour suppressive activity. Some microRNAs (miRNAs) have been implicated in progression of tumours, including gliomas. The aim was to investigate the effect of GLS and GAB expression on both miRNAs and oxidative status in glioblastoma cells. METHODS: Microarray profiling of miRNA was performed in GLS-silenced LN229 and GAB-transfected T98G human glioblastoma cells and their wild-type counterparts. Results were validated by real-time quantitative RT-PCR. Oxidative status and antioxidant enzymes were determined by spectrophotometric or fluorescence assays in GLS-silenced LN229 and T98G, and GAB-transfected LN229 and T98G. RESULTS: MiRNA-146a-5p, miRNA-140-3p, miRNA-21-5p, miRNA-1260a, and miRNA-92a-3p were downregulated, and miRNA-1246 was upregulated when GLS was knocked down. MiRNA-140-3p, miRNA-1246, miRNA-1260a, miRNA-21-5p, and miRNA-146a-5p were upregulated when GAB was overexpressed. Oxidative status (lipid peroxidation, protein carbonylation, total antioxidant capacity, and glutathione levels), as well as antioxidant enzymes (catalase, superoxide dismutase, and glutathione reductase) of silenced GLS glioblastoma cells and overexpressed GAB glioblastoma cells significantly changed versus their respective control glioblastoma cells. MiRNA-1246, miRNA-1260a, miRNA-146a-5p, and miRNA-21-5p have been characterized as strong biomarkers of glioblastoma proliferation linked to both GLS silencing and GAB overexpression. Total glutathione is a reliable biomarker of glioblastoma oxidative status steadily associated to both GLS silencing and GAB overexpression. CONCLUSIONS: Glutaminase isoenzymes are related to the expression of some miRNAs and may contribute to either tumour progression or suppression through certain miRNA-mediated pathways, proving to be a key tool to switch cancer proliferation and redox status leading to a less malignant phenotype. Accordingly, GLS and GAB expression are especially involved in glutathione-dependent antioxidant defence.

Analysis of urinary exosomal metabolites identifies cardiovascular risk signatures with added value to urine analysis.

BACKGROUND: Subclinical atherosclerosis may result in fatal cardiovascular (CV) events, but the underlying mechanisms and molecular players leading to disease are not entirely understood. Thus, novel approaches capable of identifying the factors involved in pathological progression and providing a better understanding of the subjacent mechanisms are needed. Extracellular vesicles (EVs) have been shown to have numerous biological functions, and their metabolome has recently generated interest as a source of novel biomarkers. The metabolic content of the exosomes has been so far unexplored in cardiovascular disease (CVD), and here, we developed an analytical strategy aimed at probing urinary exosomal metabolite content and its association to CV risk. RESULTS: Direct analysis of the exosomes without metabolite extraction was evaluated by high-resolution magic angle spinning (1H HR-MAS). Other two methodologies for the analysis of exosomal metabolites by 1H NMR were set up, based on methanol or organic solvents sequential extraction. The three methods were compared in terms of the number of detected signals and signal to noise ratio (S/N). The methanol method was applied to identify altered metabolites in the urinary exosomes of subjects with programmed coronary artery by-pass grafting (CABG) versus a control group. Target mass spectrometry (MS) was also performed for differential analysis. The clinical performance of exosomal metabolites of interest in CVD was investigated, and the added value of the exosomes compared to urine analysis was evaluated. Based on S/N ratio, simplicity, reproducibility, and quality of the spectrum, the methanol method was chosen for the study in CVD. A cardiometabolic signature composed by 4-aminohippuric acid, N-1-methylnicotinamide, and citric acid was identified in urinary exosomes. Directly in urine, 4-aminohippuric acid and citric acid do not show variation between groups and changes in N-1-methylnicotinamide are less pronounced, proving the added value of exosomes. CONCLUSIONS: We set up a novel methodology to analyze metabolic alterations in urinary exosomes and identified a cardiometabolic signature in these microvesicles. This study constitutes the first evidence of a role for the exosomal metabolism in CVD and demonstrates the possibility to evaluate the urinary exosomal metabolic content by NMR and MS.

Deficiency in the Phosphorylated Pathway of Serine Biosynthesis Perturbs Sulfur Assimilation.

Although the plant Phosphorylated Pathway of l-Ser Biosynthesis (PPSB) is essential for embryo and pollen development, and for root growth, its metabolic implications have not been fully investigated. A transcriptomics analysis of Arabidopsis (Arabidopsis thaliana) PPSB-deficient mutants at night, when PPSB activity is thought to be more important, suggested interaction with the sulfate assimilation process. Because sulfate assimilation occurs mainly in the light, we also investigated it in PPSB-deficient lines in the day. Key genes in the sulfate starvation response, such as the adenosine 5'phosphosulfate reductase genes, along with sulfate transporters, especially those involved in sulfate translocation in the plant, were induced in the PPSB-deficient lines. However, sulfate content was not reduced in these lines as compared with wild-type plants; besides the glutathione (GSH) steady-state levels in roots of PPSB-deficient lines were even higher than in wild type. This suggested that PPSB deficiency perturbs the sulfate assimilation process between tissues/organs. Alteration of thiol distribution in leaves from different developmental stages, and between aerial parts and roots in plants with reduced PPSB activity, provided evidence supporting this idea. Diminished PPSB activity caused an enhanced flux of 35S into thiol biosynthesis, especially in roots. GSH turnover also accelerated in the PPSB-deficient lines, supporting the notion that not only biosynthesis, but also transport and allocation, of thiols were perturbed in the PPSB mutants. Our results suggest that PPSB is required for sulfide assimilation in specific heterotrophic tissues and that a lack of PPSB activity perturbs sulfur homeostasis between photosynthetic and nonphotosynthetic tissues.

Phosphoglycerate Kinases Are Co-Regulated to Adjust Metabolism and to Optimize Growth.

In plants, phosphoglycerate kinase (PGK) converts 1,3-bisphosphoglycerate into 3-phosphoglycerate in glycolysis but also participates in the reverse reaction in gluconeogenesis and the Calvin-Benson cycle. In the databases, we found three genes that encode putative PGKs. Arabidopsis (Arabidopsis thaliana) PGK1 was localized exclusively in the chloroplasts of photosynthetic tissues, while PGK2 was expressed in the chloroplast/plastid of photosynthetic and nonphotosynthetic cells. PGK3 was expressed ubiquitously in the cytosol of all studied cell types. Measurements of carbohydrate content and photosynthetic activities in PGK mutants and silenced lines corroborated that PGK1 was the photosynthetic isoform, while PGK2 and PGK3 were the plastidial and cytosolic glycolytic isoforms, respectively. The pgk1.1 knockdown mutant displayed reduced growth, lower photosynthetic capacity, and starch content. The pgk3.2 knockout mutant was characterized by reduced growth but higher starch levels than the wild type. The pgk1.1 pgk3.2 double mutant was bigger than pgk3.2 and displayed an intermediate phenotype between the two single mutants in all measured biochemical and physiological parameters. Expression studies in PGK mutants showed that PGK1 and PGK3 were down-regulated in pgk3.2 and pgk1.1, respectively. These results indicate that the down-regulation of photosynthetic activity could be a plant strategy when glycolysis is impaired to achieve metabolic adjustment and optimize growth. The double mutants of PGK3 and the triose-phosphate transporter (pgk3.2 tpt3) displayed a drastic growth phenotype, but they were viable. This implies that other enzymes or nonspecific chloroplast transporters could provide 3-phosphoglycerate to the cytosol. Our results highlight both the complexity and the plasticity of the plant primary metabolic network.

Enhancing population stability with combined adaptive limiter control and finding the optimal harvesting-restocking balance.

Fluctuations in population size may have negative consequences (e.g., an increased risk of extinction or the occurrence of repeated outbreaks), and many management strategies are aimed at avoiding them by either only restocking or only harvesting the population. Two of these strategies are adaptive limiter control (ALC) and adaptive threshold harvesting (ATH). With ALC the population is controlled by only restocking and with ATH by only harvesting. We propose the strategy of combined adaptive limiter control (CALC) as the combination of ALC and ATH and study the potential advantages of CALC over ALC and ATH. We consider two different population models, namely a stochastic overcompensatory model and a host-pathogen-predator model. For the first model, our results show that the combination of restocking and harvesting under CALC improves the constancy stability of the managed populations when the harvesting and restocking intensities are high enough. Otherwise the effect is marginal or in rare cases negative. For the second model, we show that combining harvesting with restocking reduces the outbreak risk only if the harvesting intensity is low. For medium harvesting intensities the effect is marginal and for high harvesting intensities the risk of outbreaks is increased. In addition, we study the optimal harvesting-restocking balance by considering a proxy of the benefit obtained in terms of the reduction in the outbreak risk and the harvesting and restocking costs.

Cannabinoid Type-2 Receptor Drives Neurogenesis and Improves Functional Outcome After Stroke.

BACKGROUND AND PURPOSE: Stroke is a leading cause of adult disability characterized by physical, cognitive, and emotional disturbances. Unfortunately, pharmacological options are scarce. The cannabinoid type-2 receptor (CB2R) is neuroprotective in acute experimental stroke by anti-inflammatory mechanisms. However, its role in chronic stroke is still unknown. METHODS: Stroke was induced by permanent middle cerebral artery occlusion in mice; CB2R modulation was assessed by administering the CB2R agonist JWH133 ((6aR,10aR)-3-(1,1-dimethylbutyl)-6a,7,10,10a-tetrahydro-6,6,9-trimethyl-6H-dibenzo[b,d]pyran) or the CB2R antagonist SR144528 (N-[(1S)-endo-1,3,3-trimethylbicyclo-[2.2.1]-heptan-2-yl]-5-(4-chloro-3-methylphenyl)-1-(4-methylbenzyl)-pyrazole-3-carboxamide) once daily from day 3 to the end of the experiment or by CB2R genetic deletion. Analysis of immunofluorescence-labeled brain sections, 5-bromo-2´-deoxyuridine (BrdU) staining, fluorescence-activated cell sorter analysis of brain cell suspensions, and behavioral tests were performed. RESULTS: SR144528 decreased neuroblast migration toward the boundary of the infarct area when compared with vehicle-treated mice 14 days after middle cerebral artery occlusion. Consistently, mice on this pharmacological treatment, like mice with CB2R genetic deletion, displayed a lower number of new neurons (NeuN+/BrdU+ cells) in peri-infarct cortex 28 days after stroke when compared with vehicle-treated group, an effect accompanied by a worse sensorimotor performance in behavioral tests. The CB2R agonist did not affect neurogenesis or outcome in vivo, but increased the migration of neural progenitor cells in vitro; the CB2R antagonist alone did not affect in vitro migration. CONCLUSIONS: Our data support that CB2R is fundamental for driving neuroblast migration and suggest that an endocannabinoid tone is required for poststroke neurogenesis by promoting neuroblast migration toward the injured brain tissue, increasing the number of new cortical neurons and, conceivably, enhancing motor functional recovery after stroke.

Glutamine Addiction In Gliomas.

Cancer cells develop and succeed by shifting to different metabolic programs compared with their normal cell counterparts. One of the classical hallmarks of cancer cells is their higher glycolysis rate and lactate production even in the presence of abundant O2 (Warburg effect). Another common metabolic feature of cancer cells is a high rate of glutamine (Gln) consumption normally exceeding their biosynthetic and energetic needs. The term Gln addiction is now widely used to reflect the strong dependence shown by most cancer cells for this essential nitrogen substrate after metabolic reprogramming. A Gln/glutamate (Glu) cycle occurs between host tissues and the tumor in order to maximize its growth and proliferation rates. The mechanistic basis for this deregulated tumor metabolism and how these changes are connected to oncogenic and tumor suppressor pathways are becoming increasingly understood. Based on these advances, new avenues of research have been initiated to find novel therapeutic targets and to explore strategies that interfere with glutamine metabolism as anticancer therapies. In this review, we provided an updated overview of glutamine addiction in glioma, the most prevalent type of brain tumor.

Glutamate and Brain Glutaminases in Drug Addiction.

Glutamate is the principal excitatory neurotransmitter in the central nervous system and its actions are related to the behavioral effects of psychostimulant drugs. In the last two decades, basic neuroscience research and preclinical studies with animal models are suggesting a critical role for glutamate transmission in drug reward, reinforcement, and relapse. Although most of the interest has been centered in post-synaptic glutamate receptors, the presynaptic synthesis of glutamate through brain glutaminases may also contribute to imbalances in glutamate homeostasis, a key feature of the glutamatergic hypothesis of addiction. Glutaminases are the main glutamate-producing enzymes in brain and dysregulation of their function have been associated with neurodegenerative diseases and neurological disorders; however, the possible implication of these enzymes in drug addiction remains largely unknown. This mini-review focuses on brain glutaminase isozymes and their alterations by in vivo exposure to drugs of abuse, which are discussed in the context of the glutamate homeostasis theory of addiction. Recent findings from mouse models have shown that drugs induce changes in the expression profiles of key glutamatergic transmission genes, although the molecular mechanisms that regulate drug-induced neuronal sensitization and behavioral plasticity are not clear.

Plastidial Glycolytic Glyceraldehyde-3-Phosphate Dehydrogenase Is an Important Determinant in the Carbon and Nitrogen Metabolism of Heterotrophic Cells in Arabidopsis.

This study functionally characterizes the Arabidopsis (Arabidopsis thaliana) plastidial glycolytic isoforms of glyceraldehyde-3-phosphate dehydrogenase (GAPCp) in photosynthetic and heterotrophic cells. We expressed the enzyme in gapcp double mutants (gapcp1gapcp2) under the control of photosynthetic (Rubisco small subunit RBCS2B [RBCS]) or heterotrophic (phosphate transporter PHT1.2 [PHT]) cell-specific promoters. Expression of GAPCp1 under the control of RBCS in gapcp1gapcp2 had no significant effect on the metabolite profile or growth in the aerial part (AP). GAPCp1 expression under the control of the PHT promoter clearly affected Arabidopsis development by increasing the number of lateral roots and having a major effect on AP growth and metabolite profile. Our results indicate that GAPCp1 is not functionally important in photosynthetic cells but plays a fundamental role in roots and in heterotrophic cells of the AP. Specifically, GAPCp activity may be required in root meristems and the root cap for normal primary root growth. Transcriptomic and metabolomic analyses indicate that the lack of GAPCp activity affects nitrogen and carbon metabolism as well as mineral nutrition and that glycerate and glutamine are the main metabolites responding to GAPCp activity. Thus, GAPCp could be an important metabolic connector of glycolysis with other pathways, such as the phosphorylated pathway of serine biosynthesis, the ammonium assimilation pathway, or the metabolism of γ-aminobutyrate, which in turn affect plant development.

The phosphorylated pathway of serine biosynthesis is essential both for male gametophyte and embryo development and for root growth in Arabidopsis.

This study characterizes the phosphorylated pathway of Ser biosynthesis (PPSB) in Arabidopsis thaliana by targeting phosphoserine phosphatase (PSP1), the last enzyme of the pathway. Lack of PSP1 activity delayed embryo development, leading to aborted embryos that could be classified as early curled cotyledons. The embryo-lethal phenotype of psp1 mutants could be complemented with PSP1 cDNA under the control of Pro35S (Pro35S:PSP1). However, this construct, which was poorly expressed in the anther tapetum, did not complement mutant fertility. Microspore development in psp1.1/psp1.1 Pro35S:PSP1 arrested at the polarized stage. The tapetum from these lines displayed delayed and irregular development. The expression of PSP1 in the tapetum at critical stages of microspore development suggests that PSP1 activity in this cell layer is essential in pollen development. In addition to embryo death and male sterility, conditional psp1 mutants displayed a short-root phenotype, which was reverted in the presence of Ser. A metabolomic study demonstrated that the PPSB plays a crucial role in plant metabolism by affecting glycolysis, the tricarboxylic acid cycle, and the biosynthesis of amino acids. We provide evidence of the crucial role of the PPSB in embryo, pollen, and root development and suggest that this pathway is an important link connecting primary metabolism with development.

Adaptive threshold harvesting and the suppression of transients.

Fluctuations in population size are in many cases undesirable, as they can induce outbreaks and extinctions or impede the optimal management of populations. We propose the strategy of adaptive threshold harvesting (ATH) to control fluctuations in population size. In this strategy, the population is harvested whenever population size has grown beyond a certain proportion in comparison to the previous generation. Taking such population increases into account, ATH intervenes also at smaller population sizes than the strategy of threshold harvesting. Moreover, ATH is the harvesting version of adaptive limiter control (ALC) that has recently been shown to stabilize population oscillations in both experiments and theoretical studies. We find that ATH has similar stabilization properties as ALC and thus offers itself as a harvesting alternative for the control of pests, exploitation of biological resources, or when restocking interventions required from ALC are unfeasible. We present numerical simulations of ATH to illustrate its performance in the presence of noise, lattice effect, and Allee effect. In addition, we propose an adjustment to both ATH and ALC that restricts interventions when control seems unnecessary, i.e. when population size is too small or too large, respectively. This adjustment cancels prolonged transients.

Portal vein thrombosis in patients with cirrhosis: just a common finding or a predictor of poor outcome?

 Background & Aims. It is unclear whether portal vein thrombosis (PVT) unrelated to malignancy is associated with reduced survival or it is an epiphenomenon of advanced cirrhosis. The objective of this study was to assess clinical outcome in cirrhotic patients with PVT not associated with malignancy and determine its prevalence. MATERIAL AND METHODS: Retrospective search in one center from June 2011 to December 2014. RESULTS: 169 patients, 55 women and 114 men, median age 54 (19-90) years. Thirteen had PVT (7.6%). None of the patients received anticoagulant treatment. The PVT group was younger (49 [25-62] vs. 55 [19-90] years p = 0.025). Child A patients were more frequent in PVT and Child C in Non-PVT. Median Model for End Stage Liver Disease (MELD) score was lower in PVT (12 [8-21] vs. 19 [7-51] p ≤ 0.001) p ≤ 0.001). There was no difference between upper gastrointestinal bleeding and spontaneous bacterial peritonitis in the groups. Encephalopathy grade 3-4 (4 [30.8%] vs. 73 [46.8%] p = 0,007) and large volume ascites (5 [38.5%] vs. 89 [57.1%] p= 0,012) was more common in non-PVT. Survival was better for PVT (16.5 ± 27.9 vs. 4.13 ± 12.2 months p = 0.005). CONCLUSIONS: We found that PVT itself does not lead to a worse prognosis. The most reliable predictor for clinical outcome remains the MELD score. The presence of PVT could be just an epiphenomenon and not a marker of advanced cirrhosis.

Developing Evidence-Based Practice questionnaire for community health nurses: reliability and validity of a Spanish adaptation.

AIMS AND OBJECTIVES: This study aimed to translate the community nursing version of the Developing Evidence-Based Practice questionnaire, adapt the Spanish translation to the primary care context in Spain, and evaluate its reliability and validity. BACKGROUND: Instruments available in Spanish to date are not designed to rigorously evaluate barriers and incentives associated with evidence-based practice implementation in community health nursing. DESIGN: Classical Test Theory approach. METHODS: The 49-item Developing Evidence-Based Practice questionnaire was translated, back-translated and pilot-tested. Two items were added to assess respondents' ability to read and understand the English language. During the first six months of 2010, 513 nurses from 255 primary health care centres in Catalunya (Spain) voluntarily participated in the study. Internal consistency and test-retest reliability were evaluated. Internal structure was analysed by principal component analysis. A randomized, controlled, parallel-design study was carried out to test scores' sensitivity to change with two groups, intervention and control. The intervention consisted of eight hours of in-person training, provided by experts in evidence-based practice. RESULTS: Of 513 nurses, 445 (86·7%) nurses responded to all 51 items. Factor analysis showed six components that explained 51% of the total variance. Internal consistency and test-retest reliability were satisfactory (Cronbach α and intraclass correlation coefficients >0·70). A total of 93 nurses participated in the sensitivity-to-change tests (42 in the intervention group, 51 controls). After the training session, overall score and the 'skills for evidence-based practice' component score showed a medium (Cohen d = 0·69) and large effect (Cohen d = 0·86), respectively. CONCLUSIONS: The Developing Evidence-Based Practice questionnaire adapted to community health nursing in the primary care setting in Spain has satisfactory psychometric properties. RELEVANCE TO CLINICAL PRACTICE: The Developing Evidence-Based Practice questionnaire is a useful tool for planning and evaluating the implementation of evidence-based practice in community health nursing.

Expression of Gls and Gls2 glutaminase isoforms in astrocytes.

The expression of glutaminase in glial cells has been a controversial issue and matter of debate for many years. Actually, glutaminase is essentially considered as a neuronal marker in brain. Astrocytes are endowed with efficient and high capacity transport systems to recapture synaptic glutamate which seems to be consistent with the absence of glutaminase in these glial cells. In this work, a comprehensive study was devised to elucidate expression of glutaminase in neuroglia and, more concretely, in astrocytes. Immunocytochemistry in rat and human brain tissues employing isoform-specific antibodies revealed expression of both Gls and Gls2 glutaminase isozymes in glutamatergic and GABAergic neuronal populations as well as in astrocytes. Nevertheless, there was a different subcellular distribution: Gls isoform was always present in mitochondria while Gls2 appeared in two different locations, mitochondria and nucleus. Confocal microscopy and double immunofluorescence labeling in cultured astrocytes confirmed the same pattern previously seen in brain tissue samples. Astrocytic glutaminase expression was also assessed at the mRNA level, real-time quantitative RT-PCR detected transcripts of four glutaminase isozymes but with marked differences on their absolute copy number: the predominance of Gls isoforms over Gls2 transcripts was remarkable (ratio of 144:1). Finally, we proved that astrocytic glutaminase proteins possess enzymatic activity by in situ activity staining: concrete populations of astrocytes were labeled in the cortex, cerebellum and hippocampus of rat brain demonstrating functional catalytic activity. These results are relevant for the stoichiometry of the Glu/Gln cycle at the tripartite synapse and suggest novel functions for these classical metabolic enzymes.