260 research outputs found
Relationship between Protein Oxidation Biomarkers and Uterine Health in Dairy Cows during the Postpartum Period
High neutrophil (PMN, Polymorphonuclear neutrophil) counts in the endometrium of cows affected by endometritis, suggests the involvement of oxidative stress (OS) among the causes of impaired fertility. Protein oxidation, in particular, advanced oxidation protein products (AOPP), are OS biomarkers linked to PMN activity. To test this hypothesis, the relationship between protein oxidation and uterus health was studied in thirty-eight dairy cows during the puerperium. The animals were found to be cycling, without any signs of disease and pharmacological treatments. PMN count was performed either through a cytobrush or a uterine horn lavage (UHL). Cows were classified into four groups, based on the uterine ultrasonographic characteristics and the PMN percentage in the uterine horns with a higher percentage of high neutrophil horn (HNH). They were classified as: Healthy (H); Subclinical Endometritis (SCE); Grade 1 Endometritis (EM1); and Grade 2 Endometritis (EM2). AOPP and carbonyls were measured in plasma and UHL. UHL samples underwent Western blot analysis to visualize the carbonyl and dityrosine formation. Plasma AOPP were higher (p < 0.05) in EM2. AOPP and carbonyl group concentrations were higher in the HNH samples (p < 0.05). Protein concentration in the UHL was higher in the EM2 (p < 0.05). Carbonyl and dityrosine formation was more intense in EM1 and EM2. Protein oxidation observed in the EM2 suggests the presence of an inflammatory status in the uterus which, if not adequately hindered, could result in low fertility
INHIBITION OF MACROAUTOPHAGY AND PROTEOLYSIS IN THE ISOLATED RAT HEPATOCYTE BY A NONTRANSPORTABLE DERIVATIVE OF THE MULTIPLE ANTIGEN PEPTIDE LEU8-LYS4 -LYS2-LYS-BETA ALA
The multiple antigen peptide derivative, Leu8-Lys4-Lys2-Lys-beta Ala (Leu8-MAP), was synthesized by attaching the carboxyl of leucine to the NH2 termini of a branched lysine core, termed MAP, creating a molecule of about 1900 Da with 8 leucine residues. On a molar basis (independent of the number of leucine substitutions), Leu8-MAP was as effective as leucine in suppressing macroautophagy and proteolysis; moreover, it exhibited the same apparent Km (about 0.1 mM). The effect was specific for leucine since Ile8-MAP was inactive. It is of interest, though, that Leu8-MAP did not elicit the multiphasic response typical of leucine but instead evoked the single site inhibition normally seen with leucine plus the co-regulator alanine. Some free leucine was produced from Leu8-MAP during hepatocyte incubations, but the amounts were insufficient to account for the inhibition. Although this degradation created species of Leu-MAP that had lost 1-3 residues of leucine, their inhibitory effectiveness was not diminished. Because the extracellular/intracellular distribution ratio of [3H]-Leu8-MAP was 100:1 or greater, the direct transport of Leu8-MAP across the plasma membrane into the cytosolic compartment can be excluded. Hence, cytosolic concentrations of Leu8-MAP will be at least 100-fold smaller than those of leucine under conditions of comparable proteolytic inhibition. For these and related reasons, effects attributable to the recognition of Leu8-MAP cannot be explained by signals generated within the cytosol. They could, however, be mediated from site(s) on the plasma membrane or within associated vesicles
Catalytically active bovine serum amine oxidase bound to fluorescent and magnetically drivable nanoparticles
Novel superparamagnetic surface-active maghemite nanoparticles (SAMNs) characterized by a diameter of 10 ± 2 nm were modified with bovine serum amine oxidase, which used rhodamine B isothiocyanate (RITC) adduct as a fluorescent spacer-arm. A fluorescent and magnetically drivable adduct comprised of bovine serum copper-containing amine oxidase (SAMNâRITCâBSAO) that immobilized on the surface of specifically functionalized magnetic nanoparticles was developed. The multifunctional nanomaterial was characterized using transmission electron microscopy, infrared spectroscopy, mass spectrometry, and activity measurements. The results of this study demonstrated that bare magnetic nanoparticles form stable colloidal suspensions in aqueous solutions. The maximum binding capacity of bovine serum amine oxidase was approximately 6.4 mg gâ1 nanoparticles. The immobilization procedure reduced the catalytic activity of the native enzyme to 30% ± 10% and the Michaelis constant was increased by a factor of 2. We suggest that the SAMNâRITCâBSAO complex, characterized by a specific activity of 0.81 IU gâ1, could be used in the presence of polyamines to create a fluorescent magnetically drivable H2O2 and aldehydes-producing system. Selective tumor cell destruction is suggested as a potential future application of this system
miRNA Signatures in Sera of Patients with Active Pulmonary Tuberculosis.
Several studies showed that assessing levels of specific circulating microRNAs (miRNAs) is a non-invasive, rapid, and accurate method for diagnosing diseases or detecting alterations in physiological conditions. We aimed to identify a serum miRNA signature to be used for the diagnosis of tuberculosis (TB). To account for variations due to the genetic makeup, we enrolled adults from two study settings in Europe and Africa. The following categories of subjects were considered: healthy (H), active pulmonary TB (PTB), active pulmonary TB, HIV co-infected (PTB/HIV), latent TB infection (LTBI), other pulmonary infections (OPI), and active extra-pulmonary TB (EPTB). Sera from 10 subjects of the same category were pooled and, after total RNA extraction, screened for miRNA levels by TaqMan low-density arrays. After identification of "relevant miRNAs", we refined the serum miRNA signature discriminating between H and PTB on individual subjects. Signatures were analyzed for their diagnostic performances using a multivariate logistic model and a Relevance Vector Machine (RVM) model. A leave-one-out-cross-validation (LOOCV) approach was adopted for assessing how both models could perform in practice. The analysis on pooled specimens identified selected miRNAs as discriminatory for the categories analyzed. On individual serum samples, we showed that 15 miRNAs serve as signature for H and PTB categories with a diagnostic accuracy of 82% (CI 70.2-90.0), and 77% (CI 64.2-85.9) in a RVM and a logistic classification model, respectively. Considering the different ethnicity, by selecting the specific signature for the European group (10 miRNAs) the diagnostic accuracy increased up to 83% (CI 68.1-92.1), and 81% (65.0-90.3), respectively. The African-specific signature (12 miRNAs) increased the diagnostic accuracy up to 95% (CI 76.4-99.1), and 100% (83.9-100.0), respectively. Serum miRNA signatures represent an interesting source of biomarkers for TB disease with the potential to discriminate between PTB and LTBI, but also among the other categories
Inactivation of the glutathione peroxidase GPx4 by the ferroptosis-inducing molecule RSL3 requires the adaptor protein 14-3-3 epsilon
RSL3, a drug candidate prototype for cancer chemotherapy, triggers ferroptosis by inactivating GPx4. Here we report the purification of the protein indispensable for GPx4 inactivation by RSL3. MS analysis reveals 14-3-3 isoforms as candidates and recombinant human 14-3-3epsilon confirms the identification. The function of 14-3-3\uf065 is redox-regulated. Moreover, overexpression and silencing of the gene coding for 14-3-3\uf065 consistently control the inactivation of GPx4 by RSL3. The interaction of GPx4 with a redox-regulated adaptor protein, operating in cell signalling, further contributes to frame it within redox-regulated pathways of cell survival and death and opens new therapeutic perspectives
Educational policies in response to the pandemic caused by the COVID-19 virus in Latin America: An integrative documentary review
Educational policies in the face of the pandemic caused by the COVID-19 virus took an unexpected turn in Latin America. Virtuality constituted a key opportunity for the continuity of basic fundamental services in the citizenâs right to education. The objective of this research was to analyze the educational public policies adopted by governments in Latin America in the face of the pandemic. The methodology was an integrative documentary review of the main international organizations whose documents provided relevant information on the actions to be implemented in fourteen Latin American countries. The results obtained show that the priority was to reestablish the continuity of educational services using mass communication resources, such as radio, television, digital platforms, making visible the inequity in the access to the Internet at home. It was also identified a deficiency in the competencies and digital resources of the educational community, dis-crimination and inclusion of people with some type of disability or different languages, especially in urban or rural areas because they do not have technological means. It was concluded that the educational policies in Latin America proposed during the COVID-19 period were designed with-out a real situational diagnosis in each country, to meet the demands of urban and rural areas in an equitable manner with the will of governments, providing budgets and resources that benefit the educational community, as an achievement of state policies
Mental Health Projects for University Students: A Systematic Review of the Scientific Literature Available in Portuguese, English, and Spanish
The mental health of college students has been the source of research, projects, and public policies involving education, health, and psychology professionals. Having as its axis the study of mental health and the phenomenon of psychological illness, this systematic review aims to characterize mental health programs directed to college students, as well as the forms of interventions offered to reduce the incidence of psychological disorders. From the proposal, a survey was conducted in the databases Scopus, Lilacs, and the repository Alicia, in the period between 2010 and 2021, choosing the search phrase âProgramas de saĂșde mental para universitĂĄriosâ in Portuguese, âMental health projects for university studentsâ in English, and âProyectos en salud mental para estudiantes universitariosâ in Spanish. The research areas spanned humanities and social sciences, with peer-reviewed and open access articles. The questions that instigated the study were as follows: What are the mental health problems affecting college students? What type of strategy has been adopted to map the demands of university students in relation to mental illness? How can the university space reorganize itself to work on interventional-preventive aspects, according to the studies? Initially, 740 203 articles were obtained, and after sifting through 13 productions, using the PRISMA systematization. Despite several research interrelating mental health and university space, most were dedicated to data collection, using questionnaires, inventories, and scales, standardized and non-standardized. Only three studies described intervention projects and programs to reduce the problems of psychological distress in college students. Unanimously, the investigations emphasize the need for monitoring the higher education population regarding mental health and, in parallel, the implementation of institutional public policies to meet the students' demands and reduce the rates of problems in the educational field
Insight into the mechanism of ferroptosis inhibition by ferrostatin-1
Ferroptosis is a form of cell death primed by iron and lipid hydroperoxides and prevented by GPx4. Ferrostatin-1 (fer-1) inhibits ferroptosis much more efficiently than phenolic antioxidants. Previous studies on the antioxidant efficiency of fer-1 adopted kinetic tests where a diazo compound generates the hydroperoxyl radical scavenged by the antioxidant. However, this reaction, accounting for a chain breaking effect, is only minimally useful for the description of the inhibition of ferrous iron and lipid hydroperoxide dependent peroxidation. Scavenging lipid hydroperoxyl radicals, indeed, generates lipid hydroperoxides from which ferrous iron initiates a new peroxidative chain reaction. We show that when fer-1 inhibits peroxidation, initiated by iron and traces of lipid hydroperoxides in liposomes, the pattern of oxidized species produced from traces of pre-existing hydroperoxides is practically identical to that observed following exhaustive peroxidation in the absence of the antioxidant. This supported the notion that the anti-ferroptotic activity of fer-1 is actually due to the scavenging of initiating alkoxyl radicals produced, together with other rearrangement products, by ferrous iron from lipid hydroperoxides. Notably, fer-1 is not consumed while inhibiting iron dependent lipid peroxidation. The emerging concept is that it is ferrous iron itself that reduces fer-1 radical. This was supported by electroanalytical evidence that fer-1 forms a complex with iron and further confirmed in cells by fluorescence of calcein, indicating a decrease of labile iron in the presence of fer-1. The notion of such as pseudo-catalytic cycle of the ferrostatin-iron complex was also investigated by means of quantum mechanics calculations, which confirmed the reduction of an alkoxyl radical model by fer-1 and the reduction of fer-1 radical by ferrous iron. In summary, GPx4 and fer-1 in the presence of ferrous iron, produces, by distinct mechanism, the most relevant anti-ferroptotic effect, i.e the disappearance of initiating lipid hydroperoxides
University teachers' self-perception of digital research competencies. A qualitative study conducted in Peru
Previous research warns about the limitations that some university teachers in Ibero-America have in relation to digital research competencies. The objective of this research was to analyze the research competencies from the university teacher's self-perception, contrasted with the classroom evaluation. The study had a qualitative approach. Interviews were conducted via the Zoom virtual platform, and recordings (of an average of 4 h each) of classes delivered by 10 teachers with an average age of 58 years old, in charge of scientific research courses at the postgraduate level in Peruvian universities were analyzed. The instruments used included an in-depth interview guide and a checklist. The results show that university teachers perceive themselves as specialists in the area of research, however, they present limitations when transmitting knowledge during the teaching-learning process. There is evidence of a lack of pedagogy, as well as limitations in the use of digital resources and technological tools due to their resistance to change. The conclusions reveal that it is key to make teachers aware of the paradigm shift, with a teaching that includes as digital competencies: knowing how to create and manipulate data, knowing how to use programs and information systems, knowing how to socialize and collaborate in digital environments, knowing how to exercise and respect a digital citizenship, knowing how to manage knowledge assertively, and, as we propose in this paper, knowing how to be a researcher in a digital environment
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