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Given the global burden of COVID-19 among healthcare workers (HCWs), it is expected that they face an elevated risk of developing post-COVID-19 syndrome. The objectives of this study were to evaluate the prevalence of post-COVID-19 syndrome and associated risk factors in HCWs followed for a median time of 18 months by conducting a retrospective cohort study. All HCWs with confirmed COVID-19 during the period from January 2021 to December 2022 were included in the study. HCWs were regularly assessed after COVID-19 diagnosis, so post-COVID-19 syndrome data could be collected. During the study period, 463 HCWs were included in the study, 227 (49.0%) of which experienced post-COVID-19 syndrome. The most common persistent symptoms were fatigue (n = 147 [32.5%]), memory disorders (n = 98 [21.5%]), dyspnea (n = 73 [16.0%]), anxiety/depression (n = 69 [15.0%]), and cough (n = 43 [9.4%]). Female sex and obesity were statistically associated with the development of post-COVID-19 syndrome. A high prevalence of post-COVID-19 syndrome in HCWs was found. Female sex and obesity appear to be risk factors associated with a higher prevalence of post-COVID-19 syndrome. Special attention should be given to these patients with risk factors during follow-up in the COVID-19 recovery period.
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AIM: This study examined the association of low handgrip strength (HGS) for falls in middle-aged adults and older adults every half-decade of life. METHODS: This cross-sectional study was conducted using the public data from the first wave of the Brazilian Longitudinal Study of Aging (ELSI-Brazil). The participants were allocated into seven age groups 50-54, 55-59, 60-64, 65-69, 70-74, 75-79, and ≥ 80 years. Binary logistic regression analysis was performed to identify the odds ratio (OR) of low HGS to the falls regardless of confounding variables such as sex, balance, gait speed, and total number of health conditions. RESULTS: A total of 8,112 participants aged 50-105 years (median = 62.0 years): 3,490 males (median = 60.0 years) and 4,622 females (median = 63.0 years) attended the study. Altogether, 21.5% of participants experienced at least one fall. HGS gradually decreases over each half-decade of life. In addition, low HGS presented a significative OR (p < 0.05) for falls for age groups, until 80 s, even when considering confounding variables. CONCLUSIONS: Low HGS is associated with falls in middle-aged adults over their 50 s and remained a strong measure of falls across each subsequent half-decade of life, until 80 s.
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Monoterpenes and sesquiterpenes are classes of organic compounds found in various natural products, such as the essential oil of Hyptis crenata (EOHc). The therapeutic potential of these terpenes present in EOHc is evidenced by their effect on smooth muscle and potential clinical applications. Among the highlighted monoterpenes, such as sabinene, α-pinene, and ß-pinene, a relaxing effect on rat intestinal smooth muscles is observed, attributed to interaction with calcium channels. Furthermore, monoterpenoids like borneol, cineole, and linalool also demonstrate vasorelaxant properties, suggesting potential in the treatment of cardiovascular conditions. Sesquiterpenes, such as caryophyllene and aromadendrenes, exhibit relaxing effects in various smooth muscle tissues, such as rat uterus and guinea pig ileum, indicating pharmacological potential in these areas. The translational exploration of targets, such as calcium channels and G protein-coupled receptors, highlights the importance of these compounds in discovering new therapies based on natural products for treating various medical conditions.
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Músculo Liso , Aceites Volátiles , Terpenos , Animales , Aceites Volátiles/farmacología , Aceites Volátiles/química , Músculo Liso/efectos de los fármacos , Terpenos/farmacología , Terpenos/química , Ratas , Humanos , Cobayas , Monoterpenos/farmacología , Monoterpenos/químicaRESUMEN
Inflammation is a vital mechanism that defends the organism against infections and restores homeostasis. However, when inflammation becomes uncontrolled, it leads to chronic inflammation. The NLRP3 inflammasome is crucial in chronic inflammatory responses and has become a focal point in research for new anti-inflammatory therapies. Flavonoids like catechin, apigenin, and epicatechin are known for their bioactive properties (antioxidant, anti-inflammatory, etc.), but the mechanisms behind their anti-inflammatory actions remain unclear. This study aimed to explore the ability of various flavonoids (isolated and combined) to modulate the NLRP3 inflammasome using in silico and in vitro models. Computer simulations, such as molecular docking, molecular dynamics, and MM/GBSA calculations examined the interactions between bioactive molecules and NLRP3 PYD. THP1 cells were treated with LPS + nigericin to activate NLRP3, followed by flavonoid treatment at different concentrations. THP1-derived macrophages were also treated following NLRP3 activation protocols. The assays included colorimetric, fluorometric, microscopic, and molecular techniques. The results showed that catechin, apigenin, and epicatechin had high binding affinity to NLRP3 PYD, similar to the known NLRP3 inhibitor MCC950. These flavonoids, particularly at 1 µg/mL, 0.1 µg/mL, and 0.01 µg/mL, respectively, significantly reduced LPS + nigericin effects in both cell types and decreased pro-inflammatory cytokine, caspase-1, and NLRP3 gene expression, suggesting their potential as anti-inflammatory agents through NLRP3 modulation.
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Environmental Education (EE) is key for biodiversity conservation. We aimed to evaluate the effect of an EE activity on students by evaluating their drawings. The EE activity was part of the Blonde Capuchin Project actions, which focuses on the research and conservation of the endangered blonde capuchin monkey, Sapajus flavius. The activity was comprised of four steps and lasted four hours in each school. We analysed 348 drawings made by children from eight schools in rural areas close to forest fragments inhabited by Blonde Capuchins in two municipalities in Northeast Brazil, Igarassu-PE and Mataraca-PB. The children made the drawings during the intervention in each school, specifically in steps 1 and 4 of the activity. We scored the drawings using a rubric to account for the presence of components (biotic and abiotic) and interactions (e.g., human-environment and non-human animal interactions). As an outcome of the EE activity, we found a possible increase in knowledge and awareness through the evaluation of the drawings. Thus, when resources are limited, we encourage the performance of short-term EE activities and the analysis of drawings as a tool to measure their immediate effect.
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The plant species C. sativum L. is a staple in cuisine and holds significant ethnopharmacological value. Its essential oil (EO) is of particular interest, yet its toxicity profile remains a subject of inquiry. This study aimed to elucidate the chemical constituents of C. sativum L. EO and evaluate its toxicity through various parameters, including cytotoxicity assays on HaCaT keratinocytes, in vivo toxicity tests on Galleria mellonella larvae, in vivo genotoxicity assessments on mice and cytotoxicity assays on human erythrocytes. Notably, major constituents such as 2-decen-1-ol, dec-(2E)-enal, and 1,6-octadien-3-ol were found to remain predominant. The IC50 value for the essential oil on the keratinocyte cell line was determined to be 60.13 ± 2.02 µg/mL. However, in vivo toxicity tests with G. mellonella larvae demonstrated safety at doses below 4.5 g/kg. Additionally, genotoxicity assessment revealed that a single dose of 20 mg/mL (5 mg/kg) did not induce a significant increase in micronuclei formation. EO concentrations above 250 µg/mL led to significant changes in human erythrocytes cell viability (p < 0.0001), resulting in over 60% hemolysis. These findings collectively suggest that the essential oil of C. sativum L. exhibits a suitable toxicity profile for conducting preclinical studies in vertebrate animal models.
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There is a public health concern about the use of methylphenidate (MPH) since the higher prescription for young individuals and non-clinical purposes is addressed to the limited understanding of its neurochemical and psychiatric consequences. This study aimed to evaluate the impact of early and chronic MPH treatment on the striatum focusing on amino acid profile, glutamatergic excitotoxicity, redox status, neuroinflammation and glial cell responses. Male Wistar rats were treated with MPH (2.0 mg/kg) or saline solution from the 15th to the 44th postnatal day. Biochemical and histological analyses were conducted after the last administration. MPH altered the amino acid profile in the striatum, increasing glutamate and ornithine levels, while decreasing the levels of serine, phenylalanine, and branched-chain amino acids (leucine, valine, and isoleucine). Glutamate uptake and Na+,K+-ATPase activity were decreased in the striatum of MPH-treated rats as well as increased ATP levels, as indicator of glutamatergic excitotoxicity. Moreover, MPH caused lipid peroxidation and nitrative stress, increased TNF alpha expression, and induced high levels of astrocytes, and led to a decrease in BDNF levels. In summary, our results suggest that chronic early-age treatment with MPH induces parallel activation of damage-associated pathways in the striatum and increases its vulnerability during the juvenile period. In addition, data presented here contribute to shedding light on the mechanisms underlying MPH-induced striatal damage and its potential implications for neurodevelopmental disorders.
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Aminoácidos , Astrocitos , Estimulantes del Sistema Nervioso Central , Cuerpo Estriado , Ácido Glutámico , Metilfenidato , Ratas Wistar , Animales , Masculino , Cuerpo Estriado/efectos de los fármacos , Cuerpo Estriado/metabolismo , Astrocitos/efectos de los fármacos , Astrocitos/metabolismo , Metilfenidato/toxicidad , Metilfenidato/farmacología , Ácido Glutámico/metabolismo , Ratas , Estimulantes del Sistema Nervioso Central/toxicidad , Estimulantes del Sistema Nervioso Central/farmacología , Aminoácidos/metabolismo , Peroxidación de Lípido/efectos de los fármacosRESUMEN
One Health (OH) is an integrative approach to human, animal, and environmental health and can be used as a comprehensive indicator for comparative purposes. Although an OH index has been proposed for comparing cities, states, and countries, to date, no practical study has compared countries using this approach. Accordingly, this study aimed to assess OH initiatives using a survey with a veterinary public health focus. The questionnaire contained 104 quantitative questions and was sent to representatives of governmental institutions of 32 countries in the Americas. After exclusion criteria were considered, a total of 35 questionnaires from 17 countries were analyzed, with country names remaining undisclosed during the statistical analyses to protect potentially sensitive information. Principal component analysis (PCA) of health parameters in Latin America and the Caribbean (LAC) as a function of country perception (self-vector) showed that food safety was ranked higher than public policies (p = 0.009), and that both (p = 0.003) were ranked higher than institutional routines related to zoonosis programs. National policies in accordance with international standards, regulations, recommendations, and guidelines was considered the standout topic for public policy, with higher-ranking topics including standard. Meanwhile, challenging topics included tools, preparedness, governance, and research. Food safety showed both strengths and challenges in the coordination of its activities with other sectors. Food safety communication was scored as a strength, while foodborne diseases prevention was ranked as a challenge. Institutional routines for zoonosis maintained both strong and challenging topics in the execution and implementation of attributions and daily routine. Thus, the survey showed that topics such as access to and compliance with international guidelines and intercountry integration were ranked higher than in-country articulation, particularly among food safety, zoonoses, and environmental institutions.
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Cancer, the second leading global cause of death, impacts both physically and emotionally. Conventional treatments such as surgeries, chemotherapy, and radiotherapy have adverse effects, driving the need for more precise approaches. Precision medicine enables more targeted treatments. Genetic mapping, alongside other molecular biology approaches, identifies specific genes, contributing to accurate prognoses. The review addresses, in clinical use, a molecular perspective on treatment. Biomarkers like alpha-fetoprotein, beta-human chorionic gonadotropin, 5-hydroxyindoleacetic acid, programmed death-1, and cytotoxic T lymphocyte-associated protein 4 are explored, providing valuable information. Bioinformatics, with an emphasis on artificial intelligence, revolutionizes the analysis of biological data, offering more accurate diagnoses. Techniques like liquid biopsy are emphasized for early detection. Precision medicine guides therapeutic strategies based on the molecular characteristics of the tumor, as evidenced in the molecular subtypes of breast cancer. Classifications allow personalized treatments, highlighting the role of trastuzumab and endocrine therapies. Despite the benefits, challenges persist, including high costs, tumor heterogeneity, and ethical issues. Overcoming obstacles requires collaboration, ensuring that advances in molecular biology translate into accessible benefits for all.
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BACKGROUND AND AIMS: Leprosy is a chronic infectious disease caused by Mycobacterium leprae (M. leprae), an intracellular bacillus that systematically invades the peripheral nerves. Diagnosing leprosy neuropathy is still a defying skill, and late diagnosis and treatment are still a reality. Based on the biological characteristics of M. leprae, particularly its preference for invading the Schwann cells localized at the coldest areas of human body, we hypothesized that these areas have focal demyelination that may escape detection through standard nerve conduction studies (NCSs) protocols. METHODS: Twenty-five patients with confirmed multibacillary leprosy and 14 controls were accessed. A multisegmented NCS protocol (MP) was performed, targeting short segments through the coldest areas, to identify focal areas of slowed conduction velocity. The effectiveness of this multisegmented protocol was compared to the standard protocol (SP) to detect abnormalities. RESULTS: All leprosy patients presented an abnormal study with the MP, contrasting to 19 with the SP. The most frequent NCS pattern was an asymmetric neuropathy with focal slowing of conduction velocity, found in 23 out of 25 leprosy patients. Significant differences favoring the proposed method were observed when comparing the MP with the SP. Notably, the MP increased the sensitivity to detect abnormalities by 122%, 133%, and 257% for the median, peroneal, and tibial nerves, respectively. MP also increases sensitivity to detect focal abnormalities in the ulnar nerve. INTERPRETATION: The MP protocol significantly increases the sensitivity of NCSs to detect neurophysiological abnormalities in leprosy neuropathy.
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Conducción Nerviosa , Humanos , Conducción Nerviosa/fisiología , Masculino , Femenino , Adulto , Persona de Mediana Edad , Anciano , Enfermedades del Sistema Nervioso Periférico/fisiopatología , Enfermedades del Sistema Nervioso Periférico/diagnóstico , Lepra/fisiopatología , Lepra/complicaciones , Adulto Joven , Nervios Periféricos/fisiopatología , Lepra Multibacilar/fisiopatología , Lepra Multibacilar/diagnósticoRESUMEN
BACKGROUND: Peripheral venous catheters (PVCs) remain the primary mode of short-term venous access for managing intravenous fluid, obtaining blood samples, and peripheral parenteral nutrition. They may get contaminated and require regular monitoring to prevent complications. This study evaluated the occurrence of phlebitis and its associated-clinical and microbiological indicators. METHODS: The frequency of phlebitis was evaluated in hospitalized patients of both medical and surgical fields. Subsequently, the dichotomous association between the presence of phlebitis and the clinical aspects was investigated. In parallel, the bacterial contamination of PVCs was assessed through culture-based methods, microscopy observation, and 16S rRNA gene sequencing. RESULTS: Approximately one in four patients presented phlebitis (28.4%). The most frequent symptom was erythema at access site, with or without pain, corresponding to Score 1 on the phlebitis scale (17.9%). Colonization of both lumen and external surface of PVC was observed in 31.3% of the samples. Staphylococcus and Pseudomonas were the most isolated bacterial genera on the PVC surface. No significant association was observed between the presence of phlebitis and the clinical aspects, as well as the presence of microorganisms. CONCLUSION: Microorganism were present on both internal and external PVC surface, without being associated to phlebitis.
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OBJECTIVE: The aim of this study was to evaluate the clinical characteristics and outcomes of pregnant women with COVID-19 and to compare with pregnant women without COVID-19. In addition, in the subgroup of patients who were symptomatic at the time of diagnosis, the persistence of symptoms was assessed. METHODS: This was a retrospective cohort study. All pregnant women aged ≥18 years, admitted to the maternity ward from March 2020 to September 2023 were included in the study. All patients admitted were routinely screened for SARS-CoV-2. Clinical characteristics and outcomes were registered. RESULTS: During the study period, 880 patients met the inclusion and were included in the analysis: 385 were COVID-19 positive and 495 were COVID-19 negative. In a multivariate analysis of the outcomes associated with COVID-19 among pregnant women, hospitalization and the Apgar score at 5 min were independently associated with COVID-19. Cesarean delivery, preterm birth, Apgar scores at 1 and 5 min <7, and maternal death were more frequent in pregnant women with COVID-19 admitted to ICU than in those not admitted to ICU. Approximately 30% of patients had persistence of symptoms, for at least 6 months in almost 60%. CONCLUSION: The findings of the present study suggest that COVID-19 was associated with increased morbidity and mortality among pregnant women. In addition, pregnant women with SARS-CoV-2 infection were at significantly higher risk of adverse perinatal outcomes, especially preterm birth.
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The use of recreational waters is a widespread activity worldwide, and one of the risks associated with this practice is the exposure of bathers to microorganisms that may arise due to pollution caused by inadequate infrastructure and sanitation. In the present work, we isolated Candida spp. (n = 24) from five recreational beaches in Rio de Janeiro, Brazil, in order to evaluate their susceptibility to antifungals, the production of virulence attributes and the in vivo virulence using Tenebrio molitor larvae as a model. The ITS1-5.8S-ITS2 gene sequencing identified thirteen isolates (54.1 %) as C. tropicalis, seven (29.1 %) as C. krusei (Pichia kudriavzevii), one (4.2 %) as C. rugosa (Diutina rugosa), one (4.2 %) as C. mesorugosa (Diutina mesorugosa), one (4.2 %) as C. utilis (Cyberlindnera jadinii) and one (4.2 %) as C. parapsilosis. C. tropicalis isolates showed resistance to azoles and susceptibility to amphotericin B, flucytosine and caspofungin. C. krusei isolates were resistant to fluconazole, caspofungin and itraconazole, with 42.8 % resistance to flucytosine, besides susceptibility to voriconazole and amphotericin B. The remaining species were susceptible to all tested antifungals. All Candida isolates adhered to abiotic surfaces and formed biofilm on polystyrene, albeit to varying degrees, and produced aspartic protease and hemolytic activity, which are considered fungal virulence attributes. C. tropicalis, C. krusei and C. utilis isolates produced phytase, while the only esterase producer was C. tropicalis. Regarding resistance to osmotic stress, all isolates of C. tropicalis, C. parapsilosis and C. mesorugosa grew up to 7.5 % NaCl; the remaining isolates grew up to 1.87-3.75 % NaCl. The mortality caused by fungal challenges in T. molitor larvae was variable, with C. tropicalis, C. utilis and C. parapsilosis being more virulent than C. krusei and C. rugosa complex. Collectively, the presence of these yeasts, particularly the virulent and resistant isolates, in recreational waters can pose a significant health risk to bathers.
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Antifúngicos , Candida , Farmacorresistencia Fúngica , Brasil , Antifúngicos/farmacología , Candida/efectos de los fármacos , Candida/patogenicidad , Candida/genética , Virulencia , Pruebas de Sensibilidad Microbiana , Animales , PlayasRESUMEN
Candida auris and Candida haemulonii are two emerging opportunistic pathogens that have caused an increase in clinical cases in the recent years worldwide. The differentiation of some Candida species is highly laborious, difficult, costly, and time-consuming depending on the similarity between the species. Thus, this study aimed to develop a new, faster, and less expensive methodology for differentiating between C. auris and C. haemulonii based on near-infrared (NIR) spectroscopy and multivariate analysis. C. auris CBS10913 and C. haemulonii CH02 were separated in 15 plates per species, and three isolated colonies of each plate were selected for Fourier transform near-infrared (FT-NIR) analysis, totaling 90 spectra. Subsequently, principal component analysis (PCA) and variable selection algorithms, including the successive projections algorithm (SPA) and genetic algorithm (GA) coupled with linear discriminant analysis (LDA), were employed to discern distinctive patterns among the samples. The use of PCA, SPA, and GA algorithms associated with LDA achieved 100% sensitivity and specificity for the discriminations. The SPA-LDA and GA-LDA algorithms were essential in selecting the variables (infrared wavelengths) of most importance for the models, which could be attributed to binding of cell wall structures such as polysaccharides, peptides, proteins, or molecules resulting from yeasts' metabolism. These results show the high potential of combined FT-NIR and multivariate analysis techniques for the classification of Candida-like fungi, which can contribute to faster and more effective diagnosis and treatment of patients affected by these microorganisms.
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3-Hydroxy-3-methylglutaric acidemia (HMGA) is a neurometabolic inherited disorder characterized by the predominant accumulation of 3-hydroxy-3-methylglutaric acid (HMG) in the brain and biological fluids of patients. Symptoms often appear in the first year of life and include mainly neurological manifestations. The neuropathophysiology is not fully elucidated, so we investigated the effects of intracerebroventricular administration of HMG on redox and bioenergetic homeostasis in the cerebral cortex and striatum of neonatal rats. Neurodevelopment parameters were also evaluated. HMG decreased the activity of glutathione reductase (GR) and increased catalase (CAT) in the cerebral cortex. In the striatum, HMG reduced the activities of superoxide dismutase, glutathione peroxidase, CAT, GR, glutathione S-transferase, and glucose-6-phosphate dehydrogenase. Regarding bioenergetics, HMG decreased the activities of succinate dehydrogenase and respiratory chain complexes II-III and IV in the cortex. HMG also decreased the activities of citrate synthase and succinate dehydrogenase, as well as complex IV in the striatum. HMG further increased DRP1 levels in the cortex, indicating mitochondrial fission. Finally, we found that the HMG-injected animals showed impaired performance in all sensorimotor tests examined. Our findings provide evidence that HMG causes oxidative stress, bioenergetic dysfunction, and neurodevelopmental changes in neonatal rats, which may explain the neuropathophysiology of HMGA.
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Fonsecaea pedrosoi is a melanized fungus that causes chromoblastomycosis (CBM), a tropical neglected disease responsible for chronic and disability-related subcutaneous mycosis. Given the challenging nature of CBM treatment, the study of new targets and novel bioactive drugs capable of improving patient life quality is urgent. In the present work, we detected a calcineurin activity in F. pedrosoi conidial form, employing primarily colorimetric, immunoblotting and flow cytometry assays. Our findings reveal that the calcineurin activity of F. pedrosoi was stimulated by Ca2+/calmodulin, inhibited by EGTA and specific inhibitors, such as tacrolimus (FK506) and cyclosporine A (CsA), and proved to be insensitive to okadaic acid. In addition, FK506 and CsA were able to affect the cellular viability and the fungal proliferation. This effect was corroborated by transmission electron microscopy that showed both calcineurin inhibitors promoted profound changes in the ultrastructure of conidia, causing mainly cytoplasm condensation and intense vacuolization that are clear indication of cell death. Our data indicated that FK506 exhibited the highest effectiveness, with a minimum inhibitory concentration (MIC) of 3.12 mg/L, whereas CsA required 15.6 mg/L to inhibit 100% of conidial growth. Interestingly, when both were combined with itraconazole, they demonstrated anti-F. pedrosoi activity, exhibiting a synergistic effect. Moreover, the fungal filamentation was affected after treatment with both calcineurin inhibitors. These data corroborate with other calcineurin studies in fungal cells and open up further discussions aiming to establish the role of this enzyme as a potential target for antifungal therapy against CBM infections.
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OBJECTIVE: To verify the association between low self-reported sleep quality (LSQ) and fall in middle-aged and older adults every half-decade of life. METHOD: A cross-sectional study was conducted using data from the first wave (2015-2016) of the Brazilian Longitudinal Study of Aging (ELSI-Brazil), which is nationally representative. The sample consisted of 8,950 participants who were allocated into eight age groups: 50-54, 55-59, 60-64, 65-69, 70-74, 75-79, 80-84, and ≥ 85 years. The questionnaires used included self-reported sleep quality and the International Physical Activity Questionnaire short version. Fisher's exact test followed by binary logistic regression analysis was performed to identify the odds ratio of sleep quality for fall occurrence, controlled for confounding variables. RESULTS: Individuals aged 50-105 years (63.6 ± 10.2 years), 57.0% females and 43.0% males, participated in this study. Overall, 21.5% of participants experienced at least one fall. The relative frequency of participants classified as having high or LSQ remained constant across each half-decade of life. The LSQ exhibited a statistically significant OR (p < 0.05) for falls across age groups up to 84, even after accounting for confounding variables. CONCLUSION: LSQ is significantly associated with an increased occurrence of fall in adults aged >50 years, but not for ≥ 85 years regardless of sex and physical activity level.
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Accidentes por Caídas , Calidad del Sueño , Humanos , Femenino , Masculino , Brasil , Estudios Transversales , Anciano , Accidentes por Caídas/estadística & datos numéricos , Persona de Mediana Edad , Anciano de 80 o más Años , Estudios Longitudinales , Autoinforme , Encuestas y Cuestionarios , Factores de EdadRESUMEN
The secreted aspartic peptidases (Saps) of Candida albicans play crucial roles in various steps of fungal-host interactions. Using a flow cytometry approach, this study investigated the expression of Saps1-3 antigens after (i) incubation with soluble proteins, (ii) interaction with mammalian cells, and (iii) infection in immunosuppressed BALB/c mice. Supplementation strategies involving increasing concentrations of bovine serum albumin (BSA) added to yeast carbon base (YCB) medium as the sole nitrogenous source revealed a positive and significant correlation between BSA concentration and both the growth rate and the percentage of fluorescent cells (%FC) labeled with anti-Saps1-3 antibodies. Supplementing the YCB medium with various soluble proteins significantly modulated the expression of Saps1-3 antigens in C. albicans. Specifically, immunoglobulin G, gelatin, and total bovine/human sera significantly reduced the %FC, while laminin, human serum albumin, fibrinogen, hemoglobin, and mucin considerably increased the %FC compared to BSA. Furthermore, co-cultivating C. albicans yeasts with either live epithelial or macrophage cells induced the expression of Saps1-3 antigens in 78% (mean fluorescence intensity [MFI] = 152.1) and 82.7% (MFI = 178.2) of the yeast cells, respectively, compared to BSA, which resulted in 29.3% fluorescent cells (MFI = 50.9). Lastly, the yeasts recovered from the kidneys of infected immunosuppressed mice demonstrated a 4.8-fold increase in the production of Saps1-3 antigens (MFI = 246.6) compared to BSA, with 95.5% of yeasts labeled with anti-Saps1-3 antibodies. Altogether, these results demonstrated the positive modulation of Saps' expression in C. albicans by various key host proteinaceous components, as well as by in vitro and in vivo host challenges.
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Candida species undeniably rank as the most prevalent opportunistic human fungal pathogens worldwide, with Candida albicans as the predominant representative. However, the emergence of non-albicans Candida species (NACs) has marked a significant shift, accompanied by rising incidence rates and concerning trends of antifungal resistance. The search for new strategies to combat antifungal-resistant Candida strains is of paramount importance. Recently, our research group reported the anti-Candida activity of a coordination compound containing copper(II) complexed with theophylline (theo) and 1,10-phenanthroline (phen), known as "CTP" - Cu(theo)2phen(H2O).5H2O. In the present work, we investigated the mechanisms of action of CTP against six medically relevant, antifungal-resistant NACs, including C. auris, C. glabrata, C. haemulonii, C. krusei, C. parapsilosis and C. tropicalis. CTP demonstrated significant efficacy in inhibiting mitochondrial dehydrogenases, leading to heightened intracellular reactive oxygen species production. CTP treatment resulted in substantial damage to the plasma membrane, as evidenced by the passive incorporation of propidium iodide, and induced DNA fragmentation as revealed by the TUNEL assay. Scanning electron microscopy images of post-CTP treatment NACs further illustrated profound alterations in the fungal surface morphology, including invaginations, cavitations and lysis. These surface modifications significantly impacted the ability of Candida cells to adhere to a polystyrene surface and to form robust biofilm structures. Moreover, CTP was effective in disassembling mature biofilms formed by these NACs. In conclusion, CTP represents a promising avenue for the development of novel antifungals with innovative mechanisms of action against clinically relevant NACs that are resistant to antifungals commonly used in clinical settings.