Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 759
Filtrar
Mais filtros

Intervalo de ano de publicação
1.
Cell ; 145(2): 312-21, 2011 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-21496648

RESUMO

Temperature is a global factor that affects the performance of all intracellular networks. Robustness against temperature variations is thus expected to be an essential network property, particularly in organisms without inherent temperature control. Here, we combine experimental analyses with computational modeling to investigate thermal robustness of signaling in chemotaxis of Escherichia coli, a relatively simple and well-established model for systems biology. We show that steady-state and kinetic pathway parameters that are essential for chemotactic performance are indeed temperature-compensated in the entire physiological range. Thermal robustness of steady-state pathway output is ensured at several levels by mutual compensation of temperature effects on activities of individual pathway components. Moreover, the effect of temperature on adaptation kinetics is counterbalanced by preprogrammed temperature dependence of enzyme synthesis and stability to achieve nearly optimal performance at the growth temperature. Similar compensatory mechanisms are expected to ensure thermal robustness in other systems.


Assuntos
Quimiotaxia , Escherichia coli/fisiologia , Transdução de Sinais , Adaptação Fisiológica , Escherichia coli/enzimologia , Transferência Ressonante de Energia de Fluorescência , Cinética , Metilação , Monoéster Fosfórico Hidrolases/metabolismo , Fosfotransferases/metabolismo , Temperatura
2.
Adv Physiol Educ ; 48(1): 80-87, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38031724

RESUMO

Use of digital flashcards promotes active recall, spaced repetition, and self-assessment academic principles. This work explores the association and dose-dependent effect of this study method and locomotor (LP) and cardiovascular physiology (CP) grades. A single-faculty cohort study of medical LP and CP students was conducted, and 155 and 676 flashcards, respectively, were created through Moodle. An exploratory analysis examined three exam results (2019), and a confirmatory study used a fourth exam (2021) in another CP cohort. Of 685 students enrolled, 558 participated in the exploratory analysis: 319 (69%) for LP and 311 (84%) for CP, of which 203 LP and 267 CP students were flashcard users. Median grades were higher among flashcard users, and the number of cards reviewed was positively correlated with grades (r = 0.275 to 0.388 for LP and r = 0.239 to 0.432 for CP, P < 0.001). Multiple linear regression models confirmed a positive dose-dependent association between results and the number of flashcards studied: for every 100 LP cards reviewed, exam grades increased 0.44-0.75 on a 0-20 scale range (P < 0.001), and for every 1,000 CP flashcards, results raised 0.81-1.08 values (P < 0.05). These findings were confirmed in the 2021 CP cohort of 269 participants, of whom 67% were flashcard users. Digital flashcard revision has a consistent positive dose-dependent association on LP and CP grades.NEW & NOTEWORTHY Implementing flashcard-based strategies is a feasible way to promote active recall, spaced repetition, and self-assessment, and students are highly adherent to these initiatives. There is a positive dose-dependent association between the number of flashcards reviewed and physiology grades. These results are consistent across different physiology subjects, under different cohorts, over short and medium terms.


Assuntos
Autoavaliação (Psicologia) , Estudantes , Humanos , Estudos de Coortes , Modelos Lineares
3.
Adv Mind Body Med ; 28(1): 4-8, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38787680

RESUMO

Objective: Recent scientific literature points out that religiosity and spirituality play a relevant role in many aspects of life, including health issues. We aimed to evaluate the healthcare students' perceptions about approaching spirituality in their training and patient care in Brazilian universities. Methods: A cross-sectional observational study was conducted following the STROBE guidelines. Through an anonymous online survey, adult healthcare students from two universities in the city of Pelotas (Brazil) answered a questionnaire about their perceptions on approaching spirituality in their training and patient care. Chi-squared tests were performed, and P ≤ .05 was considered statistically significant. Results: A total of 163 students were included in the analysis. Most believed that spirituality is important for their training (74.8%) and patient care (84%). However, a minority had had contact with the theme of spirituality during their training (48.5%) or had experienced a situation in which the spiritual aspects of a patient were addressed (47.2%). The students from the private university had more contact with the theme of spirituality in healthcare during their training. Nursing students had significantly more contact with the theme of spirituality in healthcare (P = .008) and had experienced more situations in which the spiritual aspects of a patient were addressed (P = .031) than other students. Conclusion: Most students believed that the theme of spirituality in healthcare is important for their training and patient care. However, they still had insufficient contact with it during their education. More studies with greater statistical power are needed to better understand this situation globally.


Assuntos
Espiritualidade , Humanos , Estudos Transversais , Masculino , Feminino , Adulto , Adulto Jovem , Inquéritos e Questionários , Assistência ao Paciente , Brasil , Estudantes de Ciências da Saúde/psicologia
4.
J Med Virol ; 95(8): e29046, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37605969

RESUMO

Rabies is a fatal viral zoonosis caused by rabies virus (RABV). RABV infects the central nervous system and triggers acute encephalomyelitis in both humans and animals. Endemic in the Brazilian Northeast region, RABV emergence in distinct wildlife species has been identified as a source of human rabies infection and as such, constitutes a public health concern. Here, we performed post-mortem RABV analyses of 144 encephalic tissues from bats sampled from January to July 2022, belonging to 15 different species. We identified phylogenetically distinct RABV from Phyllostomidae and Molossidae bats circulating in Northeastern Brazil. Phylogenetic clustering revealed the close evolutionary relationship between RABV viruses circulating in bats and variants hosted in white-tufted marmosets, commonly captured to be kept as pets and linked to human rabies cases and deaths in Brazil. Our findings underline the urgent need to implement a phylogenetic-scale epidemiological surveillance platform to track multiple RABV variants which may pose a threat to both humans and animals.


Assuntos
Quirópteros , Vírus da Raiva , Raiva , Animais , Humanos , Callithrix , Vírus da Raiva/genética , Raiva/epidemiologia , Raiva/veterinária , Brasil/epidemiologia , Filogenia
5.
J Cardiovasc Electrophysiol ; 34(1): 24-34, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36317466

RESUMO

INTRODUCTION: Recurrence of atrial fibrillation (AF) within the blanking period after catheter ablation (CA) is traditionally classified as a transient and benign event. However, recent findings suggest that early recurrence (ER) is associated with late recurrence (LR), challenging the predefined "blanking period". We aimed to determine the clinical and procedural predictors of ER and LR after CA and establish the risk of LR in patients who experience ER. METHODS AND RESULTS: Retrospective single-centre study including all patients who underwent a first procedure of AF CA between 2017 and 2019. ER was defined as any recurrence of AF, atrial flutter or atrial tachycardia >30 s within 90 days after CA and LR as any recurrence after 90 days of CA. A total of 399 patients were included, 37% women, median age of 58 years [49-66] and 77% had paroxysmal AF. Median follow-up was 33 months (from 13 to 61). ER after CA was present in 14% of the patients, and LR was reported in 32%. Among patients who experienced ER, 84% also had LR (p < .001). Patients with ER had a higher prevalence of moderate/severe valvular heart disease, persistent AF, previous electrical cardioversion, a larger left atrium, higher coronary artery calcium score, and higher rates of intraprocedural electrical cardioversion and cardiac fibrosis on eletroanatomical mapping compared with patients without ER. After covariate adjustment, ER and female sex were defined as independent predictors of LR (hazard ratio [HR] 4.69; 95% confidence interval [CI], 2.99-7.35; p < .001 and HR 2.73; 95% CI, 1.47-5.10; p = .002, respectively). CONCLUSION: The risk of LR after an index procedure of CA was significantly higher in patients with ER (five-fold increased risk). These results support the imperative need to clarify the clinical role of the blanking period.


Assuntos
Fibrilação Atrial , Ablação por Cateter , Humanos , Feminino , Pessoa de Meia-Idade , Masculino , Fibrilação Atrial/diagnóstico , Fibrilação Atrial/cirurgia , Fibrilação Atrial/etiologia , Estudos Retrospectivos , Relevância Clínica , Resultado do Tratamento , Ablação por Cateter/efeitos adversos , Ablação por Cateter/métodos , Recidiva
6.
Rev Cardiovasc Med ; 24(1): 1, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-39076855

RESUMO

Heart failure with preserved ejection fraction (HFpEF) is a complex clinical syndrome with high morbidity and increasing socio-economic burden, compounded by the lack of effective treatment options available to treat this disease. Sodium-glucose cotransporter-2 (SGLT2) inhibitors have previously been shown to improve cardiovascular and renal outcomes in patients with type 2 diabetes and patients with heart failure with reduced ejection fraction (HFrEF). Recent major clinical trials with SGLT2 inhibitors, both empagliflozin and dapagliflozin, have now demonstrated improved cardiovascular outcomes in patients with HFpEF and a significant reduction in heart failure hospitalization. Current evidence shows a potential for cardiovascular benefits with SGLT2 inhibition that is consistent across the spectrum of ejection fraction, age, New York Heart Association (NYHA) functional class, natriuretic peptide levels and diabetes status. Although the cardioprotective mechanisms behind SGLT2 inhibition remain unclear, ongoing clinical studies aim to clarify the role of SGLT2 inhibitors on biomarkers of cardiac metabolism, diastolic function and exercise capacity in HFpEF. This article analyzes current clinical evidence from randomized controlled trials and meta-analyses and explores the potential cardioprotective mechanisms of SGLT2 inhibitors, while also looking towards the future of SGLT2 inhibition in HFpEF.

7.
Virol J ; 20(1): 83, 2023 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-37131237

RESUMO

Hepatitis E virus (HEV) circulation in humans and swine has been extensively studied in South America over the last two decades. Nevertheless, only 2.1% of reported HEV strains are available as complete genome sequences. Therefore, many clinical, epidemiological, and evolutionary aspects of circulating HEV in the continent still need to be clarified. Here, we conducted a retrospective evolutionary analysis of one human case and six swine HEV strains previously reported in northeastern, southern, and southeastern Brazil. We obtained two complete and four nearly complete genomic sequences. Evolutionary analysis comparing the whole genomic and capsid gene sequences revealed high genetic variability. This included the circulation of at least one unrecognized unique South American subtype. Our results corroborate that sequencing the whole capsid gene could be used as an alternative for HEV subtype assignment in the absence of complete genomic sequences. Moreover, our results substantiate the evidence for zoonotic transmission by comparing a larger genomic fragment recovered from the sample of the autochthonous human hepatitis E case. Further studies should continuously investigate HEV genetic diversity and zoonotic transmission of HEV in South America.


Assuntos
Vírus da Hepatite E , Suínos , Humanos , Animais , Vírus da Hepatite E/genética , Brasil/epidemiologia , Estudos Retrospectivos , Análise de Sequência de DNA , Genótipo , Filogenia
8.
Cardiology ; 148(5): 427-433, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37487471

RESUMO

INTRODUCTION: There is a well-established association between atrial fibrillation (AF) and coronary artery disease. Coronary artery calcium score (CACS) is a helpful tool to refine cardiovascular (CV) risk stratification and inform on the best strategies for primary CV prevention. This study aims to evaluate the impact of opportunistic screening with CACS on risk stratification and decision of preventive therapies, in patients with AF. METHODS: Cross-sectional study including patients with AF or atrial flutter undergoing cardiac computed tomography for ablation procedure planning, from 2017 to 2019. Baseline clinical and demographical data were collected. CACS was assessed in patients without coronary artery disease using the Agatston method. RESULTS: A total of 474 patients were included (93% with AF, mean age of 58 ± 10 years, 62% male). CACS >0 was present in 254 (54%) patients. According to CACS and the Society of Cardiovascular Computed Tomography recommendations, 25% of the patients would be candidates for statin therapy and 17% would be candidates for changes in the current statin intensity; in 11 patients (8%), acetylsalicylic acid would be recommended. CONCLUSION: In our study, more than half of the patients undergoing cardiac computed tomography before AF catheter ablation had CACS above zero. Our findings suggest that an opportunistic evaluation of CACS at the time of ablation can be an important tool to improve CV risk stratification, with important clinical and therapeutic implications.


Assuntos
Fibrilação Atrial , Doenças Cardiovasculares , Doença da Artéria Coronariana , Inibidores de Hidroximetilglutaril-CoA Redutases , Humanos , Masculino , Pessoa de Meia-Idade , Idoso , Feminino , Doença da Artéria Coronariana/complicações , Doença da Artéria Coronariana/diagnóstico por imagem , Doença da Artéria Coronariana/cirurgia , Fibrilação Atrial/complicações , Fibrilação Atrial/cirurgia , Fibrilação Atrial/tratamento farmacológico , Doenças Cardiovasculares/etiologia , Doenças Cardiovasculares/tratamento farmacológico , Cálcio , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Estudos Transversais , Fatores de Risco , Medição de Risco , Angiografia Coronária/métodos , Valor Preditivo dos Testes
9.
J Appl Microbiol ; 134(1)2023 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-36724247

RESUMO

AIMS: Characterize Escherichia coli and E. coli -producing (STEC) isolates from Brazilian beef to determine heat resistance and the presence of the transmissible locus of stress tolerance (tLST). METHODS AND RESULTS: Twenty-two STEC previously isolated from beef and characterized as STEC by PCR were subjected to different heat survival challenges (60°C and 71°C). Furthermore, the three tLST-positive isolates and one tLST-negative isolate by PCR were selected for WGS analysis. Phenotypic results indicated that 3/22 (13.64%) were heat resistant, 12/22 (54.54%) were moderately resistant, and 7/22 (31.82%) were sensitive to heat treatments. WGS analyses showed that three isolates with heat resistance showed tLST with up to 80% and 42% of similarity by BLAST analysis, with the major tLST genes being responsible for the homeostasis module. However, WGS showed the absence of stx genes associated with tLST-positive isolates, albeit with virulence and resistance genes found in extraintestinal pathogenic E. coli (ExPEC). CONCLUSION: Our findings demonstrate the presence of heat-resistant E. coli as well as confirm some tLST genes in E. coli isolated from Brazilian beef.


Assuntos
Infecções por Escherichia coli , Proteínas de Escherichia coli , Escherichia coli Shiga Toxigênica , Animais , Bovinos , Temperatura Alta , Brasil , Proteínas de Escherichia coli/genética , Escherichia coli Shiga Toxigênica/genética , Fatores de Virulência/genética , Genômica
10.
BMC Med Inform Decis Mak ; 23(1): 12, 2023 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-36658526

RESUMO

BACKGROUND: Intensive Care Unit (ICU) readmissions represent both a health risk for patients,with increased mortality rates and overall health deterioration, and a financial burden for healthcare facilities. As healthcare became more data-driven with the introduction of Electronic Health Records (EHR), machine learning methods have been applied to predict ICU readmission risk. However, these methods disregard the meaning and relationships of data objects and work blindly over clinical data without taking into account scientific knowledge and context. Ontologies and Knowledge Graphs can help bridge this gap between data and scientific context, as they are computational artefacts that represent the entities of a domain and their relationships to each other in a formalized way. METHODS AND RESULTS: We have developed an approach that enriches EHR data with semantic annotations to ontologies to build a Knowledge Graph. A patient's ICU stay is represented by Knowledge Graph embeddings in a contextualized manner, which are used by machine learning models to predict 30-days ICU readmissions. This approach is based on several contributions: (1) an enrichment of the MIMIC-III dataset with patient-oriented annotations to various biomedical ontologies; (2) a Knowledge Graph that defines patient data with biomedical ontologies; (3) a predictive model of ICU readmission risk that uses Knowledge Graph embeddings; (4) a variant of the predictive model that targets different time points during an ICU stay. Our predictive approaches outperformed both a baseline and state-of-the-art works achieving a mean Area Under the Receiver Operating Characteristic Curve of 0.827 and an Area Under the Precision-Recall Curve of 0.691. The application of this novel approach to help clinicians decide whether a patient can be discharged has the potential to prevent the readmission of [Formula: see text] of Intensive Care Unit patients, without unnecessarily prolonging the stay of those who would not require it. CONCLUSION: The coupling of semantic annotation and Knowledge Graph embeddings affords two clear advantages: they consider scientific context and they are able to build representations of EHR information of different types in a common format. This work demonstrates the potential for impact that integrating ontologies and Knowledge Graphs into clinical machine learning applications can have.


Assuntos
Ontologias Biológicas , Readmissão do Paciente , Humanos , Reconhecimento Automatizado de Padrão , Aprendizado de Máquina , Unidades de Terapia Intensiva
11.
Sensors (Basel) ; 23(24)2023 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-38139704

RESUMO

The emergence of Industry 4.0 and 5.0 technologies has enabled the digital transformation of various processes and the integration of sensors with the internet. Despite these strides, many industrial sectors still rely on visual inspection of physical processes, especially those employing analog gauges. This method of monitoring introduces the risk of human errors and inefficiencies. Automating these processes has the potential, not only to boost productivity for companies, but also potentially reduce risks for workers. Therefore, this paper proposes an end-to-end solution to digitize analog gauges and monitor them using computer vision through integrating them into an IoT architecture, to tackle these problems. Our prototype device has been designed to capture images of gauges and transmit them to a remote server, where computer vision algorithms analyze the images and obtain gauge readings. These algorithms achieved adequate robustness and accuracy for industrial environments, with an average relative error of 0.95%. In addition, the gauge data were seamlessly integrated into an IoT platform leveraging computer vision and cloud computing technologies. This integration empowers users to create custom dashboards for real-time gauge monitoring, while also enabling them to set thresholds, alarms, and warnings, as needed. The proposed solution was tested and validated in a real-world industrial scenario, demonstrating the solution's potential to be implemented in a large-scale setting to serve workers, reduce costs, and increase productivity.

12.
J Prosthet Dent ; 2023 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-37640607

RESUMO

STATEMENT OF PROBLEM: Automated detection of dental caries could enhance early detection, save clinician time, and enrich treatment decisions. However, a reliable system is lacking. PURPOSE: The purpose of this study was to train a deep learning model and to assess its ability to detect and classify dental caries. MATERIAL AND METHODS: Bitewings radiographs with a 1876×1402-pixel resolution were collected, segmented, and anonymized with a radiographic image analysis software program and were identified and classified according to the modified King Abdulaziz University (KAU) classification for dental caries. The method was based on supervised learning algorithms trained on semantic segmentation tasks. RESULTS: The mean score for the intersection-over-union of the model was 0.55 for proximal carious lesions on a 5-category segmentation assignment and a mean F1 score of 0.535 using 554 training samples. CONCLUSIONS: The study validated the high potential for developing an accurate caries detection model that will expedite caries identification, assess clinician decision-making, and improve the quality of patient care.

13.
J Virol ; 95(22): e0127621, 2021 10 27.
Artigo em Inglês | MEDLINE | ID: mdl-34495692

RESUMO

The emergence of life-threatening zoonotic diseases caused by betacoronaviruses, including the ongoing coronavirus disease 19 (COVID-19) pandemic, has highlighted the need for developing preclinical models mirroring respiratory and systemic pathophysiological manifestations seen in infected humans. Here, we showed that C57BL/6J wild-type mice intranasally inoculated with the murine betacoronavirus murine hepatitis coronavirus 3 (MHV-3) develop a robust inflammatory response leading to acute lung injuries, including alveolar edema, hemorrhage, and fibrin thrombi. Although such histopathological changes seemed to resolve as the infection advanced, they efficiently impaired respiratory function, as the infected mice displayed restricted lung distention and increased respiratory frequency and ventilation. Following respiratory manifestation, the MHV-3 infection became systemic, and a high virus burden could be detected in multiple organs along with morphological changes. The systemic manifestation of MHV-3 infection was also marked by a sharp drop in the number of circulating platelets and lymphocytes, besides the augmented concentration of the proinflammatory cytokines interleukin 1 beta (IL-1ß), IL-6, IL-12, gamma interferon (IFN-γ), and tumor necrosis factor (TNF), thereby mirroring some clinical features observed in moderate and severe cases of COVID-19. Importantly, both respiratory and systemic changes triggered by MHV-3 infection were greatly prevented by blocking TNF signaling, either via genetic or pharmacologic approaches. In line with this, TNF blockage also diminished the infection-mediated release of proinflammatory cytokines and virus replication of human epithelial lung cells infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Collectively, results show that MHV-3 respiratory infection leads to a large range of clinical manifestations in mice and may constitute an attractive, lower-cost, biosafety level 2 (BSL2) in vivo platform for evaluating the respiratory and multiorgan involvement of betacoronavirus infections. IMPORTANCE Mouse models have long been used as valuable in vivo platforms to investigate the pathogenesis of viral infections and effective countermeasures. The natural resistance of mice to the novel betacoronavirus SARS-CoV-2, the causative agent of COVID-19, has launched a race toward the characterization of SARS-CoV-2 infection in other animals (e.g., hamsters, cats, ferrets, bats, and monkeys), as well as adaptation of the mouse model, by modifying either the host or the virus. In the present study, we utilized a natural pathogen of mice, MHV, as a prototype to model betacoronavirus-induced acute lung injure and multiorgan involvement under biosafety level 2 conditions. We showed that C57BL/6J mice intranasally inoculated with MHV-3 develops severe disease, which includes acute lung damage and respiratory distress that precede systemic inflammation and death. Accordingly, the proposed animal model may provide a useful tool for studies regarding betacoronavirus respiratory infection and related diseases.


Assuntos
Infecções por Coronavirus/patologia , Modelos Animais de Doenças , Pulmão/patologia , Vírus da Hepatite Murina/patogenicidade , Animais , Linhagem Celular , Contenção de Riscos Biológicos , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/virologia , Citocinas/metabolismo , Humanos , Inflamação , Fígado/patologia , Fígado/virologia , Pulmão/virologia , Camundongos , Vírus da Hepatite Murina/efeitos dos fármacos , Vírus da Hepatite Murina/fisiologia , SARS-CoV-2/efeitos dos fármacos , SARS-CoV-2/patogenicidade , SARS-CoV-2/fisiologia , Transdução de Sinais/efeitos dos fármacos , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Fator de Necrose Tumoral alfa/metabolismo , Replicação Viral/efeitos dos fármacos
14.
Biomacromolecules ; 23(3): 1169-1182, 2022 03 14.
Artigo em Inglês | MEDLINE | ID: mdl-35025509

RESUMO

Amphotericin B (AmB) is a highly hydrophobic drug with significant leishmanicidal activity whose use is limited by its poor water solubility and adverse effects. Polymer-drug conjugates are proposed as a delivery system designed to overcome those limitations while improving drug bioavailability, safety, and activity. Here, AmB was covalently linked to periodate-oxidized hyaluronic acid (HA) (oxidation degree of 30.1 ± 5.6%) via a Schiff base (HA-AmB imine). The conjugate presents high water solubility and self-assembles into particles with a mean size of 88.2 ± 17.6 nm, a negative charge (-28.3 ± 0.9 mV), and a drug content of 17.8 ± 1.4%. Spectroscopic studies revealed the presence of AmB in aggregate and super-aggregated forms in the conjugate, which could explain the significant reduction of the in vitro cytotoxicity and hemolytic activity. The formulation showed not only in vitro anti-leishmanial activity against L. infantum-infected macrophages (IC50 = 0.023 µM) but also against an in vivo infected mouse model, promoting a 1.32- and a 4.98-log10 suppression of the L. infantum burden in the spleens and liver, respectively, without toxic effects. In summary, this study describes the safe and effective use of water-soluble HA-AmB imine conjugates for leishmaniasis treatment.


Assuntos
Anfotericina B , Ácido Hialurônico , Anfotericina B/química , Anfotericina B/farmacologia , Animais , Antifúngicos/química , Iminas , Camundongos , Água
15.
Transfus Apher Sci ; 61(5): 103439, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35431115

RESUMO

One of the effects of the pandemic in the hemotherapy services was the reduction in the attendance of blood donors and production of blood components. It is relevant to investigate how the capacity to meet the demand for blood components was affected, especially in blood centers located in the regions most affected by the pandemic, such as Brazil. This study aimed to describe the impact of the pandemic on the capacity to meet the demand for different types of blood components by a Brazilian blood center in 2020, compared to the historical series of 2016-2019 and to discuss the measures adopted to mitigate the effects of the pandemic. Retrospective cross-sectional study was carried out with comparative analysis of the blood components requested and attended in the period from 2016 to 2020. Data analysis was performed by Graphpad Prism 5. The spread of COVID-19 cases since March 2020 had impact on the blood components production and transfusions. The reduction in the production of blood components was observed prior to the restriction measures, in March 2020. In comparison to 2016-2019, there was a reduction in the number of transfusions performed in all months of 2020. The results suggest that the measures adopted in a Brazilian blood center to face the COVID-19 pandemic resulted in reasonable regularity in the supply of blood components. The sharing of experiences between blood banks in different regions, social and epidemiological contexts can contribute to the improvement of strategies to reduce the impact of COVID-19 in transfusion medicine.


Assuntos
Armazenamento de Sangue , COVID-19 , Humanos , Armazenamento de Sangue/métodos , COVID-19/epidemiologia , Pandemias , Brasil/epidemiologia , SARS-CoV-2 , Estudos Retrospectivos , Estudos Transversais
16.
Neurol Sci ; 43(8): 4997-5005, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35469073

RESUMO

OBJECTIVE: The objective of this study is to describe the first series of spinocerebellar ataxia (SCA) in Rio de Janeiro, whose population has a high proportion of mixed Portuguese and African ancestry. METHODS: We reviewed the medical records of patients with progressive ataxia evaluated at the Sarah Network of Rehabilitation Hospitals (Rio de Janeiro). Clinical course, genetic tests for hereditary ataxia, brain MRI, and electroneuromyography were analyzed. RESULTS: SCA was confirmed in 128 individuals, one-third of African descendants. SCA3 predominated (83.6%), followed by SCA7 (7%); SCA2 (3.9%); SCA1, SCA6, and SCA8 (1.6% each); and SCA10 (0.8%). Dysphagia, pyramidal signs, and neurogenic bladder occurred frequently. Oculomotor disorders occurred with SCA3, SCA7, SCA2, and SCA1; peripheral neuropathies with SCA3 and SCA1; extrapyramidal syndromes with SCA3, SCA7, and SCA2; bilateral visual impairment with SCA7; and epilepsy with SCA10. Mobility assistance was required in 75% after 11 years and wheelchair in 25%. The Scale for the Assessment and Rating of Ataxia scores at the last follow-up varied from 2 to 37 (median = 14.50) and correlated positively with duration of the disease. In SCA3, a higher CAG repeats correlated with a lower age at onset. African ethnicity was associated with earlier onset, regardless of CAG repeats. The main brain MRI abnormality was cerebellar atrophy, isolated or associated with brainstem atrophy, "hot cross bun" sign, or brain atrophy. Linear T2 hyperintensity along the medial margin of the globus pallidus occurred in SCA3, SCA2, SCA1, and SCA7. ENMG confirmed peripheral neuropathy in SCA3 and SCA1. CONCLUSION: Machado Joseph disease/SCA3 was the most frequent inherited dominant ataxia in Rio de Janeiro. This study revealed new aspects of ethnic influence in the clinical course and new MRI findings.


Assuntos
Doenças do Sistema Nervoso Periférico , Ataxias Espinocerebelares , Atrofia , Brasil/epidemiologia , Expansão das Repetições de DNA , Humanos , Ataxias Espinocerebelares/complicações , Ataxias Espinocerebelares/diagnóstico por imagem , Ataxias Espinocerebelares/epidemiologia
17.
Drug Chem Toxicol ; 45(2): 688-697, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32448000

RESUMO

Endophytic fungi are promising sources of bioactive substances; however, their secondary metabolites are toxic to plants, animals, and humans. This study aimed toevaluate the toxic, cytotoxic, mutagenic and oxidant/antioxidant activities of acetonitrile extract (AEPc), citrinin (CIT) and dicitrinin-A (DIC-A) of Penicillium citrinum. For this, the test substances at 0.5; 1.0; 1.5 and 2 µg/mLwere exposed for 24 and 48 h in Artemia salina, and 48 h in Allium cepa test systems. The oxidant/antioxidant test was evaluated in pre-, co- and post-treatment with the stressor hydrogen peroxide (H2O2) in Saccharomyces cerevisiae. The results suggest that the AEPc, CIT and DIC-A at 0.5; 1.0; 1.5 and 2 µg/mL showed toxicity in A. saline, with LC50 (24 h) of 2.03 µg/mL, 1.71 µg/mL and 2.29 µg/mL, and LC50 (48 h) of 0.51 µg/mL, 0.54 µg/mL and 0.54 µg/mL, respectively.In A. cepa, the test substances also exerted cytotoxic and mutagenic effects. The AEPc, CIT and DIC-A at lower concentrations modulated the damage induced by H2O2 in the proficient and mutant strains of S. cerevisiae for cytoplasmic and mitochondrial superoxide dismutase. Moreover, the AEPc at 2 µg/mL and CIT at the two highest concentrations did not affect the H2O2-induced DNA damage in the test strains. In conclusion, AEPc, CIT and DIC-A of P. citrinum may exert their toxic, cytotoxic and mutagenic effects in the test systems possibly through oxidative stress induction pathway.


Assuntos
Citrinina , Acetonitrilas/toxicidade , Animais , Citrinina/toxicidade , Humanos , Peróxido de Hidrogênio/toxicidade , Penicillium , Extratos Vegetais/toxicidade , Saccharomyces cerevisiae/genética
18.
Rev Cardiovasc Med ; 22(3): 903-910, 2021 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-34565089

RESUMO

Exercise-based cardiac rehabilitation (EBCR) is paramount after an acute myocardial infarction (AMI). Older individuals have been reported as having a worse prognosis after an AMI, and some series have reported differences in the functional response to EBCR. The peak circulatory power (CP), a non-invasive parameter, has been described as a surrogate for the cardiac power, showing promising results as a comprehensive measure of the cardiovascular response. Whilst this, data concerning the impact of EBCR on CP, particularly among elderly individuals, remains elusive. To address this issue, an observational, retrospective study including all patients admitted due to an AMI who completed a phase II EBCR programme between 11/2012 and 4/2017, was conducted, with CP being analysed by a symptom-limited cardiopulmonary exercise test. A total of 379 patients, 30% aged ≥65 years-old, were included. CP significantly improved after the EBCR programme (in all patients, as well as in both subgroups). Older patients presented lower CP than their younger counterparts at the beginning and the end of the programme, while presenting smaller improvements (122 ± 540 vs 293 ± 638 mmHg mL/kg/min, p = 0.013). This was maintained after adjusting for several potential confounding factors. A contemporary ECBR programme was associated with significant improvements in CP among AMI patients. Though those aged ≥65 years-old presented smaller improvements in CP than younger individuals, these still presented significant increases in this parameter. These results highlight the importance of EBCR in this challenging higher risk group of patients.


Assuntos
Reabilitação Cardíaca , Infarto do Miocárdio , Idoso , Terapia por Exercício , Humanos , Infarto do Miocárdio/diagnóstico , Estudos Retrospectivos , Sobreviventes
19.
Adv Exp Med Biol ; 1329: 123-152, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34664237

RESUMO

Cancer is a complex and dynamic disease with an outcome that depends on a strict crosstalk between tumor cells and other components in tumor microenvironment, namely, tumor-infiltrating immune cells, fibroblasts, cancer stem cells, adipocytes, and endothelial cells. Within the tumor microenvironment, macrophages and T-lymphocytes appear to be key effectors during the several steps of tumor initiation and progression. Tumor cells, through the release of a plethora of signaling molecules, can induce immune tolerance, by avoiding immune surveillance, and inhibit immune cells cytotoxic functions. Furthermore, as the tumor grows, tumor microenvironment reveals a series of dysfunctional conditions that potentiate a polarization of harmful humoral Th2 and Th17, an upregulation of Treg cells, and a differentiation of macrophages into the M2 subtype, which contribute to the activation of several signaling pathways involving important tissue biomarkers (COX-2, EGFR, VEGF) implicated in cancer aggressiveness and poor clinical outcomes. In order to maintain the tumor growth, cancer cells acquire several adaptations such as neovascularization and metabolic reprogramming. An extensive intracellular production of lactate and protons is observed in tumor cells as a result of their high glycolytic metabolism. This contributes not only for the microenvironment pH alteration but also to shape the immune response that ultimately impairs immune cells capabilities and effector functions.In this chapter, the complexity of tumor microenvironment, with special focus on macrophages, T-lymphocytes, and the impact of lactate efflux, was reviewed, always trying to demonstrate the strong similarities between data from studies of humans and dogs, a widely proposed model for comparative oncology studies.


Assuntos
Neoplasias , Microambiente Tumoral , Animais , Cães , Células Endoteliais , Glicólise , Macrófagos
20.
Chaos ; 31(2): 023125, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33653060

RESUMO

The routes to chaos play an important role in predictions about the transitions from regular to irregular behavior in nonlinear dynamical systems, such as electrical oscillators, chemical reactions, biomedical rhythms, and nonlinear wave coupling. Of special interest are dissipative systems obtained by adding a dissipation term in a given Hamiltonian system. If the latter satisfies the so-called twist property, the corresponding dissipative version can be called a "dissipative twist system." Transitions to chaos in these systems are well established; for instance, the Curry-Yorke route describes the transition from a quasiperiodic attractor on torus to chaos passing by a chaotic banded attractor. In this paper, we study the transitions from an attractor on torus to chaotic motion in dissipative nontwist systems. We choose the dissipative standard nontwist map, which is a non-conservative version of the standard nontwist map. In our simulations, we observe the same transition to chaos that happens in twist systems, known as a soft one, where the quasiperiodic attractor becomes wrinkled and then chaotic through the Curry-Yorke route. By the Lyapunov exponent, we study the nature of the orbits for a different set of parameters, and we observe that quasiperiodic motion and periodic and chaotic behavior are possible in the system. We observe that they can coexist in the phase space, implying in multistability. The different coexistence scenarios were studied by the basin entropy and by the boundary basin entropy.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA