Repositorio académico de acceso abierto (Univ. Autonóma de Chile)
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The Many Faces of Carbohydrate Metabolism in Male Germ Cells: From Single Molecules to Active Polymers
No full textSpermatogenesis is a complex physiological process that involves cell proliferation, meiotic division and a final cell differentiation of post-meiotic cells into spermatozoa. During this process male germ cells also undergo a metabolic differentiation process, in which post-meiotic spermatogenic cells (spermatids) but not meiotic spermatogenic cells (spermatocytes) respond differentially to D-glucose metabolism, glucose transporters (GLUTs) distribution and utilization of non-hexose substrates, such as lactate/pyruvate or dihydroxyacetone. These differences might be explained by the requirement for a specific metabolic process to support cell differentiation or in some cases, cell viability. In addition, though glycogen is considered to be the main glucose store, in male germ cells this polymer may play a novel role in cell proliferation, acting as a new marker for apoptotic events in testicular tissue via a yet unknown mechanism. In this article, we summarize the main metabolic changes that occur during male germ differentiation, with a specific focus on metabolic sources during spermatocyte to spermatid transition. The latter considering that these cells come from the same cell linage as specialized cells, but are not isolated from their environment, describing the roles from single molecules to polymers on the viability of male germ cells
Unveiling Novel Urease Inhibitors for Helicobacter pylori: A Multi-Methodological Approach from Virtual Screening and ADME to Molecular Dynamics Simulations
No full textHelicobacter pylori (Hp) infections pose a global health challenge demanding innovative therapeutic strategies by which to eradicate them. Urease, a key Hp virulence factor hydrolyzes urea, facilitating bacterial survival in the acidic gastric environment. In this study, a multi-methodological approach combining pharmacophore- and structure-based virtual screening, molecular dynamics simulations, and MM-GBSA calculations was employed to identify novel inhibitors for Hp urease (HpU). A refined dataset of 8,271,505 small molecules from the ZINC15 database underwent pharmacokinetic and physicochemical filtering, resulting in 16% of compounds for pharmacophore-based virtual screening. Molecular docking simulations were performed in successive stages, utilizing HTVS, SP, and XP algorithms. Subsequent energetic re-scoring with MM-GBSA identified promising candidates interacting with distinct urease variants. Lys219, a residue critical for urea catalysis at the urease binding site, can manifest in two forms, neutral (LYN) or carbamylated (KCX). Notably, the evaluated molecules demonstrated different interaction and energetic patterns in both protein variants. Further evaluation through ADMET predictions highlighted compounds with favorable pharmacological profiles, leading to the identification of 15 candidates. Molecular dynamics simulations revealed comparable structural stability to the control DJM, with candidates 5, 8 and 12 (CA5, CA8, and CA12, respectively) exhibiting the lowest binding free energies. These inhibitors suggest a chelating capacity that is crucial for urease inhibition. The analysis underscores the potential of CA5, CA8, and CA12 as novel HpU inhibitors. Finally, we compare our candidates with the chemical space of urease inhibitors finding physicochemical similarities with potent agents such as thiourea. © 2024 by the authors.ANID FONDECYT, (11230033, 3170107); Royal Society of Chemistry, RSC, (11230490, MCIN/AEI/10.13039/501100011033, PID2020-113147GA-I00, PID2021-122839NB-I00, R20-6912, R21-6448709305); Royal Society of Chemistry, RSC; Fondo Nacional de Desarrollo Científico y Tecnológico, FONDECYT, (11220444, FOVI230136); Fondo Nacional de Desarrollo Científico y Tecnológico, FONDECYTUniversidad Autónoma de Chil
Ethanolic Extract from Fruits of Pintoa chilensis, a Chilean Extremophile Plant. Assessment of Antioxidant Activity and In Vitro Cytotoxicity
No full textPintoa chilensis is a shrub with yellow flowers that reach up to two meters high, endemic of the Atacama Region in Chile. This species grows under special environmental conditions such as low altitude, arid areas, and directly sun-exposed habitats. In the present study, ethanolic extract was obtained from fruits of P. chilensis, and then partitioned in solvents of increasing polarity to obtain five fractions: hexane (HF), dichloromethane (DF), ethyl acetate (AF), and the residual water fraction (QF). The antioxidant activity of extracts was evaluated by using the DPPH, ABTS, and FRAP methods. The results show that the antioxidant capacity of P. chilensis is higher than that reported for other plants growing in similar environments. This effect is attributed to the highest content of flavonoids and total phenols found in P. chilensis. On the other hand, the cell viability of a breast cancer cell line (MCF-7) and a non-tumor cell line (MCF-10A) was assessed in the presence of different extract fractions. The results indicate that the hexane fraction (HF) exhibits the highest cytotoxicity on both cell lines (IC50 values equal to 35 and 45 µg/mL), whereas the dichloromethane fraction (DF) is the most selective one. The GC–MS analysis of the dichloromethane fraction (DF) shows the presence of fatty acids, sugars, and polyols as major components. © 2024 by the authors.Universidad Técnica Federico Santa María, UTFSM; Dirección de Postgrado y Programas; Fondo de Equipamiento Científico y Tecnológico, (EQM 190025); Agencia Nacional de Investigación y Desarrollo, ANID, (21210624); Agencia Nacional de Investigación y Desarrollo, ANIDUniversidad Autónoma de Chil
Synthesis, structure, and luminescence properties of a 0D organic-inorganic cadmium iodide: Combined experimental and theoretical approach
No full textHybrid organic-inorganic metal halide materials with zero-dimensional (0D) structures have emerged as a captivating field of research due to their distinctive electronic properties and remarkable broadband emission characteristics. In this study, we successfully synthesized a novel hybrid cadmium iodide compound, (BZA)2CdI4.H2O (BZA+: benzylammonium), in the form of single crystals employing the solvent-evaporation method. The room temperature single-crystal X-ray diffraction analysis revealed that (BZA)2CdI4.H2O possesses a typical 0D crystal structure, where (CdI4)2− anions are spatially isolated and surrounded by (BZA)+ cations and H2O molecules. The crystal packing is intricately governed by various non-covalent intermolecular interactions, including π–π stacking interactions, N–H…I, N–H…O, and O–H…I hydrogen bonds, quantified through Hirshfeld surface analysis. Thermal analysis further demonstrated that the removal of water molecules in the crystal lattice yields a dehydrated phase of (BZA)2(CdI4). Upon 330 nm irradiation, the title compound displayed a broad bluish-white light emission, featuring a primary band at 430 nm and a secondary band at 500 nm. Based on photoluminescence spectra measurements and density functional theory (DFT) calculations, the dual-band emission is assigned to the emission of (BZA)+ organic cations and to excitons confined in the [CdI4]2– isolated inorganic tetrahedron, respectively. Interestingly, the presence of isolated molecular units in the 0-D structure results in strongly localized charges and bluish-white light emission with Commission International de l'Eclairage (CIE) colour coordinates (0.23, 0.28). These results confirm the promise of 0D metal-halide hybrids with dual-band emission as luminescent materials for solid-state lighting. © 2024 Elsevier B.V.Deanship of Scientific Research, Imam Mohammed Ibn Saud Islamic University; Al-Imam Muhammad Ibn Saud Islamic University, IMSIU, (IMSIU-RP23011); Al-Imam Muhammad Ibn Saud Islamic University, IMSIU; Spanish Government, (PGC2018-098630-B-I00
World Medical Association Declaration of Helsinki: Ethical Principles for Medical Research Involving Human subjects. Reviewing the Latest Version
No full textThe World Medical Association (WMA) has developed the Declaration of Helsinki as a statement of ethical principles for medical research involving human subjects, including research on identifiable human material and data. It has undergone numerous revisions and amendments, the most recent being in Fortaleza–Brazil (2013). This new version includes various improvements and modifications which substantially easier to read, with a greater number of subsections. It is emphasized that the research ethics committee is recognized as a fundamental part of the research, the importance of disseminating research and compulsory informed consent. The Declaration of Helsinki is constantly evolving, and is arguably a document that provides the basis for the undertaking of any research. His knowledge and reading, is mandatory for all health professionals
Spanish version of the Self-Care of Chronic Illness Inventory: A validation study amongst community-dwelling older adults with chronic multimorbidity
No full textAim: To psychometrically assess the Spanish version of the Self-Care of Chronic Illness Inventory (SC-CII-Sp) in community-dwelling older adults with chronic multimorbidity. Design: A methodological study. Method: A total of 1260 older adults participated in the study between May 2020 and February 2022. The data were analysed using SPSS Statistics® 26 and AMOS® 24. The items' content validity index and the Fleiss' kappa were calculated to assess the SC-CII-Sp's content validity. Convergent validity was assessed by calculating the Pearson correlation coefficient between the participants' scores on the SC-CII-Sp and their scores on the Spanish Chronic Disease Self-Efficacy scale (SCD-SE). Construct validity was tested by performing a confirmatory factor analysis (CFA). The SC-CII-Sp's reliability was tested by computing the Cronbach's alpha. Results: The SC-CII-Sp showed good content and convergent validity. The CFA showed that the SC-CII-Sp has three sub-scales. The 8-item Self-Care Maintenance sub-scale has good internal consistency and is comprised of two dimensions: illness-related and health-promoting behaviour. The Self-Care Monitoring sub-scale had excellent internal consistency and its five loaded items belonged to a single dimension. The 6-item Self-Care Management sub-scale has adequate internal consistency and two dimensions: autonomous and consulting behaviour. Conclusion: The Spanish version of SC-CII is a valid and reliable instrument to be used in the assessment of self-care behaviours amongst Spanish-speaking, community-dwelling older adults with chronic multimorbidity. Implications for the Profession: Nurses need valid and reliable tools to assess self-care behaviours in Spanish-speaking community-dwelling older adults with chronic multimorbidity. This study provides a 19-item tool that allows for the comprehensive evaluation of self-care behaviours in healthy and ill states. Impact: Using the SC-CII-Sp in clinical or research settings could help nurses to examine the effects of different interventions on self-care behaviours amongst Spanish-speaking, community-dwelling older adults with chronic multimorbidity. Patient or Public Contribution: None to be reported. © 2023 The Authors. Journal of Advanced Nursing published by John Wiley & Sons Ltd.Ministerio de Ciencia e Innovación, MICINN, (AEI/10.13039/501100011033)Universidad Autónoma de Chil
Facial Esthetic Parameters: A Descriptive Analysis of Facial Class and Smile in Young Subjects
No full textFacial esthetics have an important function in psycho-social relations and is a response to anatomical and muscular dynamics; differences in facial skull position can modify a subject’s facial esthetic and smile. The aim of this research is to know smile esthetics and the presence of facial modifications. We studied standardized photographs of patients between 18 and 37 years old and determined soft tissue relation to identify the facial class in lateral images defined as class I, II or III; we analyzed their relation to dental/ gingival presentation in reference to a high, normal or low smile. The data was analyzed in a descriptive technique. The results show that the low smile has a minor percentage and a normal smile was present in 47.62% of class I subjects, 34.29% of class II subjects and 75% of class III patients; high smile was present in 54.29% of the class II subjects; the buccal corridors, as an esthetic element follows the normal parameters in a low percentage and the greater or lesser size of the buccal corridors was observed in 71.43% of class I subjects, 74.29% of class II subjects and 75% of the class III subjects. It was concluded that mayor variations exist in the smile of subjects with different facial class and that the buccal corridors was excessive in the majority of subjects, thereby demonstrating the importance of analyzing this concept of esthetics in our population
Cx43 hemichannels and panx1 channels contribute to ethanol-induced astrocyte dysfunction and damage
No full textBackground: Alcohol, a widely abused drug, significantly diminishes life quality, causing chronic diseases and psychiatric issues, with severe health, societal, and economic repercussions. Previously, we demonstrated that non-voluntary alcohol consumption increases the opening of Cx43 hemichannels and Panx1 channels in astrocytes from adolescent rats. However, whether ethanol directly affects astroglial hemichannels and, if so, how this impacts the function and survival of astrocytes remains to be elucidated. Results: Clinically relevant concentrations of ethanol boost the opening of Cx43 hemichannels and Panx1 channels in mouse cortical astrocytes, resulting in the release of ATP and glutamate. The activation of these large-pore channels is dependent on Toll-like receptor 4, P2X7 receptors, IL-1β and TNF-α signaling, p38 mitogen-activated protein kinase, and inducible nitric oxide (NO) synthase. Notably, the ethanol-induced opening of Cx43 hemichannels and Panx1 channels leads to alterations in cytokine secretion, NO production, gliotransmitter release, and astrocyte reactivity, ultimately impacting survival. Conclusion: Our study reveals a new mechanism by which ethanol impairs astrocyte function, involving the sequential stimulation of inflammatory pathways that further increase the opening of Cx43 hemichannels and Panx1 channels. We hypothesize that targeting astroglial hemichannels could be a promising pharmacological approach to preserve astrocyte function and synaptic plasticity during the progression of various alcohol use disorders. © The Author(s) 2024.Agencia Nacional de Investigación y Desarrollo, ANID; Fondo Nacional de Desarrollo Científico y Tecnológico, FONDECYT, (1210375)Universidad Autónoma de Chil
Mucogingival Abscess Following Implant Surgery
No full textThe rehabilitation of lost teeth, by means of implants has grown exponentially and thus the use of antibiotic therapy to prevent postoperative infectious pictures. The use of antibiotics has proved beneficial avoiding the failure of a large number of implants from bacterial contamination, in comparison to non-use of these. Although the use of antibiotic prophylaxis or treatment is controversial, studies suggest that antibiotic prophylaxis is more effective than antibiotic treatment in preventing postoperative infections, being 2g amoxicillin one hour before the recommended dose
Is Violence Victimization Associated with the Consumption of Ultra-Processed Food? A Population-Based Study with 96 K Adolescent Students Exploring the Mediating Role of Psychoactive Substance Use
No full textThis study analyzed the association between different types of violence victimization and ultra-processed food (UPF) consumption and explored the mediating role of alcohol, tobacco, and illicit drug use on these associations. Cross-sectional study with Brazilian students aged 13–17. Participants reported their UPF consumption, bullying and physical aggression victimization, and use of alcohol, tobacco, and illicit drugs in the last month. Generalized linear regression models and mediation analyses were adjusted for the main confounders. A total of 96,396 adolescent students (52.2% female) were analyzed. In adjusted analyses, the number of UPF consumed was higher in those experiencing bullying victimization (β = 0.18; 95% confidence interval, CI: 0.09, 0.27), aggression from parents or guardians (β = 0.27; 95% CI: 0.16, 0.38) and aggression from others (β = 0.31; 95% CI: 0.13, 0.49). The adjusted mediation models showed that these associations were partially mediated by alcohol, tobacco and illicit drug use. Among adolescents, exposure to violence victimization might potentially drive a rise in the consumption of UPF. Such associations are partially influenced by an increased use of psychoactive substances. © The Author(s) 2024.Ministerio de Educación, Cultura y Deporte, MECD, (RD21/0016/0025); Ministerio de Economía y Competitividad, MINECO; Instituto de Salud Carlos III, ISCIII; European Regional Development Fund, ERDFUniversidad Autónoma de Chil