Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 186
Filtrar
1.
Polymers (Basel) ; 16(5)2024 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-38475267

RESUMO

High-performance engineering thermoplastics offer lightweight and excellent mechanical performance in a wide temperature range. Their composites with carbon nanotubes are expected to enhance mechanical performance, while providing thermal and electrical conductivity. These are interesting attributes that may endow additional functionalities to the nanocomposites. The present work investigates the optimal conditions to prepare polyether ether ketone (PEEK)/multi-walled carbon nanotube (MWCNT) nanocomposites, minimizing the MWCNT agglomerate size while maximizing the nanocomposite electrical conductivity. The aim is to achieve PEEK/MWCNT nanocomposites that are suitable for melt-spinning of electrically conductive multifilament's. Nanocomposites were prepared with compositions ranging from 0.5 to 7 wt.% MWCNT, showing an electrical percolation threshold between 1 and 2 wt.% MWCNT (107-102 S/cm) and a rheological percolation in the same range (1 to 2 wt.% MWCNT), confirming the formation of an MWCNT network in the nanocomposite. Considering the large drop in electrical conductivity typically observed during melt-spinning and the drawing of filaments, the composition PEEK/5 wt.% MWCNT was selected for further investigation. The effect of the melt extrusion parameters, namely screw speed, temperature, and throughput, was studied by evaluating the morphology of MWCNT agglomerates, the nanocomposite rheology, and electrical properties. It was observed that the combination of the higher values of screw speed and temperature profile leads to the smaller number of MWCNT agglomerates with smaller size, albeit at a slightly lower electrical conductivity. Generally, all processing conditions tested yielded nanocomposites with electrical conductivity in the range of 0.50-0.85 S/cm. The nanocomposite processed at higher temperature and screw speed presented the lowest value of elastic modulus, perhaps owing to higher matrix degradation and lower connectivity between the agglomerates. From all the process parameters studied, the screw speed was identified to have the higher impact on nanocomposite properties.

2.
Pediatr Infect Dis J ; 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38359346

RESUMO

BACKGROUND: Population-based information regarding the impact of respiratory syncytial virus (RSV) and influenza on hospital admissions and mortality is scant for many countries. METHODS: Prospective testing of RSV and influenza virus was undertaken in patients <5 years old admitted to hospital with acute respiratory infection (ARI) between July, 2014 and June, 2015, and mortality rates for children living in 3 municipalities in the state of San Luis Potosí were calculated. RESULTS: During the 12-month study period, 790 children living in these municipalities were admitted with ARI. RSV was detected in 245 (31%) and influenza in 47 (5.9%). History of preterm birth was recorded for 112 children on admission. For children <5 years old, ARI-, RSV- and influenza-associated admission rates were 23.2, 7.2 and 1.4 (per 1000 population), respectively. The corresponding admission rates per 1000 infants <1 year old were 78, 25.2 and 4.4. Preterm infant admission rates were 2 times higher than those of term infants. Six children died; RSV was detected in 4 (66.6%) of the deceased, while no deaths were associated with influenza. ARI and RSV in-hospital mortality rates for children <5 years were 0.18 and 0.12 per 1000 population. ARI and RSV mortality rates in preterm infants were 7 and 14 times higher than in term infants, respectively. CONCLUSIONS: RSV was associated with both high admission and in-hospital mortality rates in children <5 years old. Specific interventions, such as active or passive immunization, to prevent RSV infections are required to reduce ARI-associated infant mortality.

3.
Front Oncol ; 14: 1304633, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38420017

RESUMO

Background: A heterogeneous geographic distribution of childhood acute lymphoblastic leukemia (ALL) cases has been described, possibly, related to the presence of different environmental factors. The aim of the present study was to explore the geographical distribution of childhood ALL cases in Greater Mexico City (GMC). Methods: A population-based case-control study was conducted. Children <18 years old, newly diagnosed with ALL and residents of GMC were included. Controls were patients without leukemia recruited from second-level public hospitals, frequency-matched by sex, age, and health institution with the cases. The residence address where the patients lived during the last year before diagnosis (cases) or the interview (controls) was used for geolocation. Kulldorff's spatial scan statistic was used to detect spatial clusters (SCs). Relative risks (RR), associated p-value and number of cases included for each cluster were obtained. Results: A total of 1054 cases with ALL were analyzed. Of these, 408 (38.7%) were distributed across eight SCs detected. A relative risk of 1.61 (p<0.0001) was observed for the main cluster. Similar results were noted for the remaining seven ones. Additionally, a proximity between SCs, electrical installations and petrochemical facilities was observed. Conclusions: The identification of SCs in certain regions of GMC suggest the possible role of environmental factors in the etiology of childhood ALL.

4.
Cureus ; 16(1): e52255, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38222996

RESUMO

Invasive pneumococcal disease is a serious infection with an elevated case-fatality rate that can be even higher among patients with asplenia. Its impact has been blunted by the widespread use of vaccines; even recently, in 2021, two new pneumococcal conjugate vaccines emerged. The authors present a case of a 58-year-old male, splenectomised with the immunisation schedule complete, who died of invasive pneumococcal disease with a fulminant course. It is highlighted that fever in a patient with impaired splenic function is an emergency, and despite the success of immunisation in reducing pneumococcal carriage and invasive disease, serotypes continue to change. Also, the local epidemiology may help guide situations where the immunisation recommendations are dubious regarding the implementation of the new vaccines.

5.
Int J Surg Case Rep ; 114: 109095, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38035865

RESUMO

INTRODUCTION AND IMPORTANCE: Gastric volvulus is a rare clinical entity which occurs due to the rotation of the stomach and can have life-threatening complications. This condition can have an acute or chronic presentation and its symptoms will vary according to the degree of obstruction and rapidity of onset. CASE PRESENTATION: We report a case of a 84-year-old male with history of frequent periods of constipation and lack of appetite who presented to the emergency room with left-sided abdominal pain and distension and persistent nausea, without the ability to vomit. Abdominal radiograph, computed tomography scan of the abdomen, contrast-enhanced examination and upper endoscopy were consistent with a gastric volvulus secondary to diaphragmatic eventration. The patient's symptoms resolved after nasogastric tube placement and fluid resuscitation. However, he was proposed to a laparoscopic anterior gastropexy to prevent symptom recurrence. He remains asymptomatic after 3 years of follow-up. CLINICAL DISCUSSION: The diagnosis of gastric volvulus is based mainly on clinical presentation and abdominal imaging. The main principles of surgical intervention include stomach decompression with volvulus reduction, followed by gastropexy and correction of any predisposing intra-abdominal factors. CONCLUSION: Definitive treatment of both acute and chronic gastric volvulus includes a surgical approach. Laparoscopic anterior gastropexy has been found to be a viable alternative in these patients.

7.
Environ Monit Assess ; 196(1): 61, 2023 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-38110623

RESUMO

Climate change affects ecosystems in different ways. These effects are particularly worrying in the Neotropical region, where species are most vulnerable to these changes because they live closer to their thermal safety limits. Thus, establishing conservation priorities, particularly for the definition of protected areas (PAs), is a priority. However, some PA systems within the Neotropics are ineffective even under the present environmental conditions. Here, we test the effectiveness of a PA system, within an ecotone in northern Brazil, in protecting 24 endangered bird species under current and future (RCP8.5) climatic scenarios. We used species distribution modeling and dispersal corridor modeling to describe the priority areas for conservation of these species. Our results indicate that several threatened bird taxa are and will potentially be protected (i.e., occur within PAs). Nonetheless, the amount of protected area is insufficient to maintain the species in the ecotone. Moreover, most taxa will probably present drastic declines in their range sizes; some are even predicted to go globally extinct soon. Thus, we highlight the location of a potentially effective system of dispersal corridors that connects PAs in the ecotone. We reinforce the need to implement public policies and raise public awareness to maintain PAs and mitigate anthropogenic effects within them, corridors, and adjacent areas, aiming to conserve the richness and diversity of these already threatened species.


Assuntos
Conservação dos Recursos Naturais , Ecossistema , Animais , Conservação dos Recursos Naturais/métodos , Monitoramento Ambiental , Espécies em Perigo de Extinção , Aves , Mudança Climática , Biodiversidade
8.
Front Nutr ; 10: 1278255, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38024345

RESUMO

Background: Childhood cancer is the leading cause of disease-related mortality among children aged 5-14 years in Mexico, with acute leukemia being the most common cancer among infants. Examining the overall dietary patterns allows for a comprehensive assessment of food and nutrient consumption, providing a more predictive measure of disease risk than individual foods or nutrients. This study aims to evaluate the association between maternal dietary patterns during pregnancy and the risk of acute leukemia in Mexican infants. Methods: A hospital-based case-control study was conducted, comparing 109 confirmed acute leukemia cases with 152 age-matched controls. All participants (≤24 months) were identified at hospitals in Mexico City between 2010 and 2019. Data on a posteriori dietary patterns and other relevant variables were collected through structured interviews and dietary questionnaires. Multivariate logistic regression was employed to estimate the association between maternal dietary patterns during pregnancy and the risk of acute leukemia in infants. Results: The "Balanced & Vegetable-Rich" pattern, characterized by a balanced consumption of various food groups and higher vegetable intake, exhibited a negative association with acute leukemia when compared to the "High Dairy & Cereals" Pattern (adjusted odds ratio [OR] = 0.51; 95% confidence interval [CI]: 0.29, 0.90). We observed that mothers who gave birth to girls and adhered to a healthy dietary pattern during pregnancy exhibited significantly lower odds of their children developing AL compared to those who gave birth to boys [OR = 0.32 (95% CI 0.11, 0.97)]. Our results underscore the significance of maternal nutrition as a modifiable factor in disease prevention and the importance of prenatal health education.

9.
Life (Basel) ; 13(10)2023 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-37895367

RESUMO

BACKGROUND: Exercise testing is key in the risk stratification of patients with heart failure (HF). There are scarce data on its prognostic power in women. Our aim was to assess the predictive value of the heart transplantation (HTx) thresholds in HF in women and in men. METHODS: Prospective evaluation of HF patients who underwent cardiopulmonary exercise testing (CPET) from 2009 to 2018 for the composite endpoint of cardiovascular mortality and urgent HTx. RESULTS: A total of 458 patients underwent CPET, with a composite endpoint frequency of 10.5% in females vs. 16.0% in males in 36-month follow-up. Peak VO2 (pVO2), VE/VCO2 slope and percent of predicted pVO2 were independent discriminators of the composite endpoint, particularly in women. The International Society for Heart Lung Transplantation recommended values of pVO2 ≤ 12 mL/kg/min or ≤14 if the patient is intolerant to ß-blockers, VE/VCO2 slope > 35, and percent of predicted pVO2 ≤ 50% showed a higher diagnostic effectiveness in women. Specific pVO2, VE/VCO2 slope and percent of predicted pVO2 cut-offs in each sex group presented a higher prognostic power than the recommended thresholds. CONCLUSION: Individualized sex-specific thresholds may improve patient selection for HTx. More evidence is needed to address sex differences in HF risk stratification.

10.
Heliyon ; 9(9): e19916, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37810159

RESUMO

Psychological skills are considered in sport psychology as indispensable capabilities to analyze the athlete's own vision of his or her own personality. These skills encompass self-confidence, positive and negative coping control, attentional control, visual-imaginative control, motivational level, and attitudinal control. The significance of this research lies in demonstrating the relationship established between each of the dimensions of emotional intelligence and the constituent skills of the personality. As such, this study aims to investigate the relationship between the seven factors related to psychological skills and emotional intelligence (attention, clarity, and emotional regulation). The sample comprises 163 university students pursuing degrees in Physical Activity and Sports Sciences, [70,9% (N = 117) men and 27.9% (N = 46) women] with a mean age of 20.33 years. As assessment instruments, we used two validated and standardized scales, the IPED and the TMMS-24. The main findings of this work allow us to affirm the existence of a relationship between the three dimensions of emotional intelligence and the control of both positive and negative coping, attentional control, visual-imaginative control, motivational level, and attitudinal control. In conclusion, this study underscores the necessity of cognitive and emotional training, in addition to physical training, to enhance these skills among both male and female athletes.

11.
Crit Care Sci ; 35(2): 196-202, 2023.
Artigo em Inglês, Português | MEDLINE | ID: mdl-37712809

RESUMO

OBJECTIVE: To evaluate the association between different intensive care units and levels of brain monitoring with outcomes in acute brain injury. METHODS: Patients with traumatic brain injury and subarachnoid hemorrhage admitted to intensive care units were included. Neurocritical care unit management was compared to general intensive care unit management. Patients managed with multimodal brain monitoring and optimal cerebral perfusion pressure were compared with general management patients. A good outcome was defined as a Glasgow outcome scale score of 4 or 5. RESULTS: Among 389 patients, 237 were admitted to the neurocritical care unit, and 152 were admitted to the general intensive care unit. Neurocritical care unit management patients had a lower risk of poor outcome (OR = 0.228). A subgroup of 69 patients with multimodal brain monitoring (G1) was compared with the remaining patients (G2). In the G1 and G2 groups, 59% versus 23% of patients, respectively, had a good outcome at intensive care unit discharge; 64% versus 31% had a good outcome at 28 days; 76% versus 50% had a good outcome at 3 months (p < 0.001); and 77% versus 58% had a good outcome at 6 months (p = 0.005). When outcomes were adjusted by SAPS II severity score, using good outcome as the dependent variable, the results were as follows: for G1 compared to G2, the OR was 4.607 at intensive care unit discharge (p < 0.001), 4.22 at 28 days (p = 0.001), 3.250 at 3 months (p = 0.001) and 2.529 at 6 months (p = 0.006). Patients with optimal cerebral perfusion pressure management (n = 127) had a better outcome at all points of evaluation. Mortality for those patients was significantly lower at 28 days (p = 0.001), 3 months (p < 0.001) and 6 months (p = 0.001). CONCLUSION: Multimodal brain monitoring with autoregulation and neurocritical care unit management were associated with better outcomes and should be considered after severe acute brain injury.


Assuntos
Lesões Encefálicas Traumáticas , Lesões Encefálicas , Humanos , Lesões Encefálicas/terapia , Encéfalo , Lesões Encefálicas Traumáticas/diagnóstico , Unidades de Terapia Intensiva , Escala de Resultado de Glasgow
12.
Ann Intensive Care ; 13(1): 86, 2023 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-37723384

RESUMO

BACKGROUND: Extubation during extracorporeal oxygenation (ECMO) in severe acute respiratory distress syndrome (ARDS) has not been well studied. Despite the potential benefits of this strategy, weaning from ECMO before liberation from invasive mechanical ventilation remains the most frequent approach. Our aim was to evaluate the safety and feasibility of a standardized approach for extubation during ECMO in patients with severe ARDS. RESULTS: We conducted a prospective observational study to assess the safety and feasibility of a standardized approach for extubation during ECMO in severe ARDS among 254 adult patients across 4 intensive care units (ICU) from 2 tertiary ECMO centers over 6 years. This consisted of a daily assessment of clinical and gas exchange criteria based on an Extracorporeal Life Support Organization guideline, with extubation during ECMO after validation by a dedicated intensive care medicine specialist. Fifty-four (21%) patients were extubated during ECMO, 167 (66%) did not reach the clinical criteria, and in 33 (13%) patients, gas exchange precluded extubation during ECMO. At ECMO initiation, there were fewer extrapulmonary organ dysfunctions (lower SOFA score [OR, 0.88; 95% CI, 0.79-0.98; P = .02] with similar PaO2/FiO2) when compared with patients not extubated during ECMO. Extubation during ECMO associated with shorter duration of invasive mechanical ventilation (7 (4-18) vs. 32 (18-54) days; P < .01) and of ECMO (12 (7-25) vs. 19 (10-41) days; P = .01). This was accompanied by a lower incidence of hemorrhagic shock (2 vs. 11%; P = .05), but more cannula-associated deep vein thrombosis (49 vs. 31%; P = .02) and failed extubation (20 vs. 6%; P < .01). There were no increased major adverse events. Extubation during ECMO is associated with a lower risk of all-cause death, independently of measured confounding (adjusted logistic regression OR 0.23; 95% confidence interval 0.08-0.69, P = .008). CONCLUSIONS: A standardized approach was safe and feasible allowing extubation during ECMO in 21% of patients with severe ARDS, selecting patients who will have a shorter duration of invasive mechanical ventilation, ECMO course, and ICU stay, as well as fewer infectious complications, and high hospital survival.

13.
Front Oncol ; 13: 1239147, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37746300

RESUMO

Introduction: Maternal dietary consumption during pregnancy has been inconclusively associated with acute leukemia (AL) in infants, probably because epidemiological evidence has emerged mainly from the analysis of one-by-one nutrient, which is not a real-life scenario. Our objective was to evaluate the association between AL in Mexican children under 2 years of age and their mothers' nutrients concomitant intake during pregnancy, as well as to explore whether there are differences between girls and boys. Methods: We conducted a study of 110 cases of AL and 252 hospital-based controls in the Mexico City Metropolitan area from 2010 to 2019. We obtained information on maternal intake of 32 nutrients by a food frequency questionnaire and used weighted quantile sum regression to identify nutrient concomitant intakes. Results: We found a concomitant intake of nutrients negatively associated with AL (OR 0.17; CI95% 0.03,0.88) only among girls; and we did not find a nutrient concomitant intake positively associated with AL. Discussion: This is the first study that suggests nutrients that have been individually associated with AL are not necessarily the same in the presence of other nutrients (concomitant intake); as well as that maternal diet might reduce AL risk only in girls.

14.
Medicina (Kaunas) ; 59(9)2023 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-37763804

RESUMO

Background and Objectives: Cardiopulmonary exercise testing (CPET) is a cornerstone of risk stratification in heart failure with reduced ejection fraction (HFrEF). However, there is a paucity of evidence on its predictive power in older patients. The aim of this study was to evaluate the prognostic power of current heart transplantation (HTx) listing criteria in HFrEF stratified according to age groups. Materials and Methods: Consecutive patients with HFrEF undergoing CPET between 2009 and 2018 were followed-up for cardiac death and urgent HTx. Results: CPET was performed in 458 patients with HFrEF. The composite endpoint occurred in 16.8% of patients ≤50 years vs. 14.1% of patients ≥50 years in a 36-month follow-up. Peak VO2 (pVO2), VE/VCO2 slope and percentage of predicted pVO2 were strong independent predictors of outcomes. The International Society for Heart and Lung Transplantation thresholds of pVO2 ≤ 12 mL/kg/min (≤14 if intolerant to ß-blockers), VE/VCO2 slope > 35 and percentage of predicted pVO2 ≤ 50% presented a higher overall diagnostic effectiveness in younger patients (≤50 years). Specific thresholds for each age subgroup outperformed the traditional cut-offs. Conclusions: Personalized age-specific thresholds may contribute to an accurate risk stratification in HFrEF. Further studies are needed to address the gap in evidence between younger and older patients.


Assuntos
Insuficiência Cardíaca , Transplante de Coração , Humanos , Idoso , Teste de Esforço , Volume Sistólico , Coração
15.
Arch. latinoam. nutr ; 73(supl. 2): 112-122, sept. 2023. tab
Artigo em Espanhol | LILACS, LIVECS | ID: biblio-1537254

RESUMO

Introducción. La pandemia de SARS-CoV-2/COVID-19 y las restricciones sanitarias afectaron la disponibilidad, acceso y consumo de alimentos, impactando la alimentación y el estado nutricional. Objetivo. Determinar el efecto de la pandemia SARS-CoV-2/COVID-19 sobre el cumplimiento de las Guías Alimentarias Basadas en Alimentos de Chile, en una comunidad universitaria, antes y durante la pandemia. Materiales y métodos. Estudio de cohorte retrospectiva con 427 participantes. Se aplicó una encuesta online con preguntas basadas en los mensajes de las GABA. La encuesta se validó por juicio de expertos y análisis psicométrico, evaluando la concordancia con el estadístico de Kappa (K=89,95) y la confiabilidad con el coeficiente Alfa de Cronbach (=0,97). Se fijó como período antes de la pandemia al tiempo anterior a marzo del año 2020, y durante la pandemia, entre marzo del 2020 y octubre del 2021. Para medir los cambios antes y durante la pandemia se aplicó el test de simetría considerando un p <0,05 con un intervalo de confianza del 95%, mediante el software estadístico STATA versión 16. Resultados. Se observaron cambios estadísticamente significativos antes y durante la pandemia en los mensajes relacionados con el estado nutricional (p=0,000), consumo semanal de: productos de pastelería (p=0,0040), cecinas y embutidos (p=0,0034), frituras (p=0,0070), legumbres (p=0,0000), aguas (p=0,0000) y lectura e información nutricional de los productos (p=0,0000). Conclusiones. La pandemia de SARS-CoV-2/COVID-19 generó cambios en la alimentación y estado nutricional respecto a los mensajes de las guías. Se precisan políticas alimentarias y estrategias educativas en alimentación y en nutrición para emergencias sanitarias(AU)


Introduction. The SARS-CoV-2/COVID-19 pandemic, as well as health restrictions, impacted food availability, access and consumption, affecting dietary habits and nutritional status. Objective. To determine the effect of the SARS-CoV-2/ COVID-19 pandemic on the adherence to Chilean Food-Based Dietary Guidelines, within a university community, both before and during the pandemic. Materials and methods. A retrospective cohort study involving 427 participants was conducted. An online survey was administered, with questions based on the FBDGs' messages. The survey was validated through expert judgment and psychometric analysis, and agreement was assessed using the Kappa statistic (K = 89.95) while reliability was determined using the Cronbach's Alpha coefficient ( = 0.97). The period before the pandemic was defined as the time prior to March 2020, and the pandemic period was set between March 2020 and October 2021. Changes before and during the pandemic were measured using the symmetry test, considering a p value of <0.05 and a 95% confidence level, using the STATA 16 statistical software. Results. Statistically significant changes were observed before and during the pandemic in messages related to nutritional status (p = 0.000), weekly consumption of bakery products (p = 0.0040), cold meats (p = 0.0034), fried foods (p = 0.0070), legumes (p = 0.0000), water (p = 0.0000), and messages related to reading and nutrition information of products (p = 0.0000). Conclusions. The pandemic led to dietary changes in relation to FBDGs messages. Food policies and food and nutrition education strategies are required to address health emergency contexts(AU)


Assuntos
Humanos , Masculino , Feminino , Adulto , Guias Alimentares , COVID-19 , Ingestão de Alimentos
16.
Biomedicines ; 11(8)2023 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-37626705

RESUMO

BACKGROUND: New therapies with prognostic benefits have been recently introduced in heart failure with reduced ejection fraction (HFrEF) management. The aim of this study was to evaluate the prognostic power of current listing criteria for heart transplantation (HT) in an HFrEF cohort submitted to cardiopulmonary exercise testing (CPET) between 2009 and 2014 (group A) and between 2015 and 2018 (group B). METHODS: Consecutive patients with HFrEF who underwent CPET were followed-up for cardiac death and urgent HT. RESULTS: CPET was performed in 487 patients. The composite endpoint occurred in 19.4% of group A vs. 7.4% of group B in a 36-month follow-up. Peak VO2 (pVO2) and VE/VCO2 slope were the strongest independent predictors of mortality. International Society for Heart and Lung Transplantation (ISHLT) thresholds of pVO2 ≤ 12 mL/kg/min (≤14 if intolerant to ß-blockers) and VE/VCO2 slope > 35 presented a similar and lower Youden index, respectively, in group B compared to group A, and a lower positive predictive value. pVO2 ≤ 10 mL/kg/min and VE/VCO2 slope > 40 outperformed the traditional cut-offs. An ischemic etiology subanalysis showed similar results. CONCLUSION: ISHLT thresholds showed a lower overall prognostic effectiveness in a contemporary HFrEF population. Novel parameters may be needed to improve risk stratification.

17.
Biomolecules ; 13(7)2023 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-37509119

RESUMO

A unique cytochrome P450 (CYP) oxidoreductase (CPR) sustains activities of human microsomal CYPs. Its function requires toggling between a closed conformation enabling electron transfers from NADPH to FAD and then FMN cofactors and open conformations forming complexes and transferring electrons to CYPs. We previously demonstrated that distinct features of the hinge region linking the FAD and FMN domain (FD) modulate conformer poses and their interactions with CYPs. Specific FD residues contribute in a CYP isoform-dependent manner to the recognition and electron transfer mechanisms that are additionally modulated by the structure of CYP-bound substrate. To obtain insights into the underlying mechanisms, we analyzed how hinge region and FD mutations influence CYP1A2-mediated caffeine metabolism. Activities, metabolite profiles, regiospecificity and coupling efficiencies were evaluated in regard to the structural features and molecular dynamics of complexes bearing alternate substrate poses at the CYP active site. Studies reveal that FD variants not only modulate CYP activities but surprisingly the regiospecificity of reactions. Computational approaches evidenced that the considered mutations are generally in close contact with residues at the FD-CYP interface, exhibiting induced fits during complexation and modified dynamics depending on caffeine presence and orientation. It was concluded that dynamic coupling between FD mutations, the complex interface and CYP active site exist consistently with the observed regiospecific alterations.


Assuntos
Cafeína , Citocromo P-450 CYP1A2 , Humanos , Citocromo P-450 CYP1A2/genética , Citocromo P-450 CYP1A2/metabolismo , Sistema Enzimático do Citocromo P-450/metabolismo , Transporte de Elétrons , Mutação , NADPH-Ferri-Hemoproteína Redutase/genética , NADPH-Ferri-Hemoproteína Redutase/química , NADPH-Ferri-Hemoproteína Redutase/metabolismo
19.
Behav Sci (Basel) ; 13(7)2023 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-37504036

RESUMO

In this paper, we have focused on the Self-Determination Theory, paying special attention to intrinsic motivation, which is understood as the motivation that leads the subject to perform a task without the expectation of obtaining an external reward. In the field of sport, motivation is one of the most studied variables and one of the most researched, since it is closely related to the reasons that lead the athletes to start, maintain, and abandon sports practice. The main objective of this study is to analyze the relationship between intrinsic motivation (IM) and emotional intelligence from the theoretical contributions of the Self-Determination Theory. The specific objectives are to analyze attention, clarity, and emotional regulation, as well as intrinsic motivation to acquire knowledge. Additionally, we aim to explore the relationship between attention, clarity, and emotional regulation and the intrinsic motivation to achieve something. Lastly, we investigate the correspondence between attention, clarity, and emotional regulation and the intrinsic motivation to experience stimuli. The sample consists of 163 undergraduate and master's students related to Physical Activity and Sports Sciences, studying at a Spanish public university, located in the southeast region of Andalusia-specifically, in the city of Almería. The participants had a mean age of 20.33 years. In terms of gender, 70.9% (n = 117) were men and 27.9% (n = 46) women. In terms of degree, 76.7% (n = 147) were undergraduate students and 23.3% (n = 18) were postgraduate students. The Sports Motivation Scale (SMS/EMD) was used to assess intrinsic motivation, and the TMMS-24 was used to assess emotional intelligence. The main findings of this research demonstrate the existence of a relationship between the three dimensions of emotional intelligence (emotional attention, emotional clarity, and emotional regulation) and intrinsic motivation (intrinsic motivation to know something, intrinsic motivation to achieve something, and intrinsic motivation to experience stimulation). These findings emphasize the importance of emotional intelligence for intrinsic motivation.

20.
Viruses ; 15(7)2023 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-37515204

RESUMO

Human respiratory syncytial virus (hRSV) is the leading cause of acute lower respiratory tract infections in children under five years of age and older adults worldwide. During hRSV infection, host cells undergo changes in endomembrane organelles, including mitochondria. This organelle is responsible for energy production in the cell and plays an important role in the antiviral response. The present study focuses on characterizing the ultrastructural and functional changes during hRSV infection using thin-section transmission electron microscopy and RT-qPCR. Here we report that hRSV infection alters mitochondrial morphodynamics by regulating the expression of key genes in the antiviral response process, such as Mfn1, VDAC2, and PINK1. Our results suggest that hRSV alters mitochondrial morphology during infection, producing a mitochondrial phenotype with shortened cristae, swollen matrix, and damaged membrane. We also observed that hRSV infection modulates the expression of the aforementioned genes, possibly as an evasion mechanism in the face of cellular antiviral response. Taken together, these results advance our knowledge of the ultrastructural alterations associated with hRSV infection and might guide future therapeutic efforts to develop effective antiviral drugs for hRSV treatment.


Assuntos
Infecções por Vírus Respiratório Sincicial , Vírus Sincicial Respiratório Humano , Infecções Respiratórias , Criança , Humanos , Pré-Escolar , Idoso , Vírus Sincicial Respiratório Humano/fisiologia , Dinâmica Mitocondrial , Antivirais/farmacologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...