Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 12 de 12
Filtrar
Mais filtros

Tipo de documento
Intervalo de ano de publicação
1.
Trop Med Int Health ; 28(3): 232-236, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36651761

RESUMO

OBJECTIVES: Strongyloidiasis is a nematode infection caused by Strongyloides stercoralis. Previous studies have addressed the possibility of the parasite to establish a complex relationship with the host that could affect the risk of developing diabetes mellitus or modify its presentation. This study aims to evaluate the potential impact of strongyloidiasis in diabetes mellitus and other metabolic diseases. METHODS: Case-control observational retrospective study that included 95 S. stercoralis-infected patients and 83 non-infected individuals. Epidemiological and clinical variables were retrieved from medical records, and a statistical analysis was carried out to explore any association between strongyloidiasis and diabetes mellitus and other metabolic diseases. RESULTS: Most of the patients were men (99, 55.60%) with a mean age of 42.53 ± SD 14 years. Twelve (6.70%) patients were diabetic; 30 (16.90%) presented arterial hypertension; 28 (15.70%) had dyslipidaemia; and 10 (5.60%) had thyroid pathology. When comparing patients with strongyloidiasis and uninfected patients, no differences were found regarding diabetes mellitus or other metabolic diseases. CONCLUSIONS: The results obtained in the present study do not confirm any type of association between strongyloidiasis and diabetes mellitus or other metabolic diseases.


Assuntos
Diabetes Mellitus , Strongyloides stercoralis , Estrongiloidíase , Adulto , Animais , Feminino , Humanos , Masculino , Estudos de Casos e Controles , Estudos Retrospectivos
2.
J Neurophysiol ; 120(3): 1186-1197, 2018 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-29924715

RESUMO

Male zebra finches produce a sequence-invariant set of syllables, separated by short inspiratory gaps. These songs are learned from an adult tutor and maintained throughout life, making them a tractable model system for learned, sequentially ordered behaviors, particularly speech production. Moreover, much is known about the cortical, thalamic, and brain stem areas involved in producing this behavior, with the premotor cortical nucleus HVC (proper name) being of primary importance. In a previous study, our group developed a behavioral neural network model for birdsong constrained by the structural connectivity of the song system, the signaling properties of individual neurons and circuits, and circuit-breaking behavioral studies. Here we describe a more computationally tractable model and use it to explain the behavioral effects of unilateral cooling and electrical stimulations of HVC on song production. The model demonstrates that interhemispheric switching of song control is sufficient to explain these results, consistent with the hypotheses proposed when the experiments were initially conducted. Finally, we use the model to make testable predictions that can be used to validate the model framework and explain the effects of other perturbations of the song system, such as unilateral ablations of the primary input and output nuclei of HVC. NEW & NOTEWORTHY In this report, we propose a two-hemisphere neural network model for the bilaterally symmetrical song system underlying birdsong in the male zebra finch. This model captures the behavioral effects of unilateral cooling and electrical stimulations of the premotor cortical nucleus HVC during song production, supporting the hypothesis of interhemispheric switching of song control. We use the model to make testable predictions regarding the behavioral effects of other unilateral perturbations to the song system.


Assuntos
Lateralidade Funcional , Modelos Neurológicos , Córtex Motor/fisiologia , Redes Neurais de Computação , Neurônios/fisiologia , Vocalização Animal/fisiologia , Animais , Temperatura Baixa , Estimulação Elétrica , Tentilhões , Vias Neurais/fisiologia
3.
J Neurophysiol ; 118(2): 677-692, 2017 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-28381490

RESUMO

Male zebra finches produce a song consisting of a canonical sequence of syllables, learned from a tutor and repeated throughout its adult life. Much of the neural circuitry responsible for this behavior is located in the cortical premotor region HVC (acronym is name). In a recent study from our laboratory, we found that partial bilateral ablation of the medial portion of HVC has effects on the song that are qualitatively different from those of bilateral ablation of the lateral portion. In this report we describe a neural network organization that can explain these data, and in so doing suggests key roles for other brain nuclei in the production of song. We also suggest that syllables and the gaps between them are each coded separately by neural chains within HVC, and that the timing mechanisms for syllables and gaps are distinct. The design principles underlying this model assign distinct roles for medial and lateral HVC circuitry that explain the data on medial and lateral ablations. In addition, despite the fact that the neural coding of song sequence is distributed among several brain nuclei in our model, it accounts for data showing that cooling of HVC stretches syllables uniformly and to a greater extent than gaps. Finally, the model made unanticipated predictions about details of the effects of medial and lateral HVC ablations that were then confirmed by reanalysis of these previously acquired behavioral data.NEW & NOTEWORTHY Zebra finch song consists of a string of syllables repeated in a nearly invariant sequence. We propose a neural network organization that can explain recent data indicating that the medial and lateral portions of the premotor cortical nucleus HVC have different roles in zebra finch song production. Our model explains these data, as well as data on the effects on song of cooling HVC, and makes predictions that we test in the singing bird.


Assuntos
Córtex Cerebral/fisiologia , Tentilhões/fisiologia , Modelos Neurológicos , Neurônios/fisiologia , Vocalização Animal/fisiologia , Animais , Córtex Cerebral/fisiopatologia , Aprendizagem/fisiologia , Masculino , Vias Neurais/fisiologia , Vias Neurais/fisiopatologia , Espectrografia do Som , Sinapses/fisiologia , Temperatura , Fatores de Tempo
4.
PLoS One ; 19(8): e0309243, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39186749

RESUMO

Epilepsy is one of the most common neurological disorders in children. Diagnosing epilepsy in children can be very challenging, especially as it often coexists with neurodevelopmental conditions like autism and ADHD. Functional brain networks obtained from neuroimaging and electrophysiological data in wakefulness and sleep have been shown to contain signatures of neurological disorders, and can potentially support the diagnosis and management of co-occurring neurodevelopmental conditions. In this work, we use electroencephalography (EEG) recordings from children, in restful wakefulness and sleep, to extract functional connectivity networks in different frequency bands. We explore the relationship of these networks with epilepsy diagnosis and with measures of neurodevelopmental traits, obtained from questionnaires used as screening tools for autism and ADHD. We explore differences in network markers between children with and without epilepsy in wake and sleep, and quantify the correlation between such markers and measures of neurodevelopmental traits. Our findings highlight the importance of considering the interplay between epilepsy and neurodevelopmental traits when exploring network markers of epilepsy.


Assuntos
Encéfalo , Eletroencefalografia , Epilepsia , Transtornos do Neurodesenvolvimento , Sono , Vigília , Humanos , Epilepsia/fisiopatologia , Criança , Sono/fisiologia , Masculino , Encéfalo/fisiopatologia , Encéfalo/diagnóstico por imagem , Feminino , Vigília/fisiologia , Transtornos do Neurodesenvolvimento/fisiopatologia , Adolescente , Rede Nervosa/fisiopatologia , Pré-Escolar , Transtorno do Deficit de Atenção com Hiperatividade/fisiopatologia
5.
Front Netw Physiol ; 32023 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-36987428

RESUMO

We study the impact of spatial distribution of heterogeneity on collective dynamics in gap-junction coupled beta-cell networks comprised on cells from two populations that differ in their intrinsic excitability. Initially, these populations are uniformly and randomly distributed throughout the networks. We develop and apply an iterative algorithm for perturbing the arrangement of the network such that cells from the same population are increasingly likely to be adjacent to one another. We find that the global input strength, or network drive, necessary to transition the network from a state of quiescence to a state of synchronised and oscillatory activity decreases as network sortedness increases. Moreover, for weak coupling, we find that regimes of partial synchronisation and wave propagation arise, which depend both on network drive and network sortedness. We then demonstrate the utility of this algorithm for studying the distribution of heterogeneity in general networks, for which we use Watts-Strogatz networks as a case study. This work highlights the importance of heterogeneity in node dynamics in establishing collective rhythms in complex, excitable networks and has implications for a wide range of real-world systems that exhibit such heterogeneity.

6.
Sci Rep ; 13(1): 13223, 2023 08 14.
Artigo em Inglês | MEDLINE | ID: mdl-37580497

RESUMO

The objective of this study was to assess the benefits and potential risks associated with different physical exercise modalities for managing symptoms in adults with major depressive disorder who were not receiving second-generation antidepressants or cognitive behavioral therapy. A systematic review and meta-analysis of randomized controlled trials (RCTs) were conducted. The search included multiple databases: Medline, Cochrane Central Register of Controlled Trials (CENTRAL), Embase, PsycInfo, Web of Science, Clinical Trials repository, gray literature, and manual search. No language restrictions were applied. Eligible studies involved RCTs of adults with major depressive disorder who were not on antidepressants or receiving psychological therapy, comparing various exercise modalities with second-generation antidepressants or cognitive behavioral therapy, body-mind exercise, or no exercise interventions. Nine RCTs involving 678 adults were analyzed. The pooled results indicated a small clinical effect favoring exercise in reducing depressive symptoms, although the difference was not statistically significant (SMD = 0.27, 95% CI [- 0.58, 0.04], P = 0.09). Subgroup analyses suggested that intervention duration, frequency, intensity, supervision, age, overweight/obesity status, and diagnosis of depression could influence treatment outcomes. A sensitivity analysis was conducted for studies with controls without exercise interventions and a low risk of bias in the domains related to the randomization process and deviations from the intended interventions. The results showed that there are no statistically significant differences when interventions are compared with medication and body-mind exercise (p = 0.12, I2 = 78%). Furthermore, the analysis showed a moderate effect size favoring exercise, but no statistically significant difference between groups (p = 0.05), with high heterogeneity (I2 = 85%). The evidence quality was generally low to very low, and methodological limitations compromised the certainty of the findings. Adverse events associated with exercise were manageable. The study emphasizes the need for well-designed RCTs to provide clearer insights into the potential benefits of exercise in managing major depressive disorder symptoms. Caution is warranted in interpreting these results due to the limitations of the included studies.Systematic review registration: PROSPERO CRD42022356741.


Assuntos
Antidepressivos de Segunda Geração , Terapia Cognitivo-Comportamental , Transtorno Depressivo Maior , Adulto , Humanos , Transtorno Depressivo Maior/tratamento farmacológico , Antidepressivos/uso terapêutico , Antidepressivos de Segunda Geração/uso terapêutico , Exercício Físico
7.
World J Plast Surg ; 12(1): 63-71, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37220582

RESUMO

Degloving is a type of avulsion injury that leads to the separation of the skin from its underlying tissues. It is usually caused by industrial machinery through smashing or traction mechanisms, where the patient typically tries to avoid severe trauma by pulling their hand off, resulting in this particular injury. Although free flaps have now become the standard of treatment in many institutions, the lack of this possibility makes pedicled flaps a good reconstructive option, with advantages such as low donor-site morbidity, low procedure costs, and relatively easy dissection of the flap. Since the description of the pedicled groin flap technique by McGregor and Jackson, this reconstructive option has become a versatile flap for the coverage of wounds on the hand and distal forearm. This axial-patterned cutaneous flap is based on the superficial circumflex arteriovenous system, which can provide soft-tissue coverage for moderate-to-severe injuries, especially those caused by work accidents. This article aims to describe our experience in treating five different cases of traumatic degloving hand injuries using a groin flap for coverage, with excellent aesthetic and functional results. Two of these cases resulted from degloving after a traction accident, one from a firework explosion, one from a gunshot, and finally, one as a result of an electric wound.

8.
Nat Commun ; 13(1): 994, 2022 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-35194035

RESUMO

Modelling the interactions that arise from neural dynamics in seizure genesis is challenging but important in the effort to improve the success of epilepsy surgery. Dynamical network models developed from physiological evidence offer insights into rapidly evolving brain networks in the epileptic seizure. A limitation of previous studies in this field is the dependence on invasive cortical recordings with constrained spatial sampling of brain regions that might be involved in seizure dynamics. Here, we propose virtual intracranial electroencephalography (ViEEG), which combines non-invasive ictal magnetoencephalographic imaging (MEG), dynamical network models and a virtual resection technique. In this proof-of-concept study, we show that ViEEG signals reconstructed from MEG alone preserve critical temporospatial characteristics for dynamical approaches to identify brain areas involved in seizure generation. We show the non-invasive ViEEG approach may have some advantage over intracranial electroencephalography (iEEG). Future work may be designed to test the potential of the virtual iEEG approach for use in surgical management of epilepsy.


Assuntos
Eletrocorticografia , Epilepsia , Eletrocorticografia/métodos , Eletroencefalografia/métodos , Epilepsia/cirurgia , Humanos , Magnetoencefalografia/métodos , Convulsões
9.
J R Soc Interface ; 19(189): 20210925, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35472267

RESUMO

Major surgery and critical illness produce a potentially life-threatening systemic inflammatory response. The hypothalamic-pituitary-adrenal (HPA) axis is one of the key physiological systems that counterbalances this systemic inflammation through changes in adrenocorticotrophic hormone (ACTH) and cortisol. These hormones normally exhibit highly correlated ultradian pulsatility with an amplitude modulated by circadian processes. However, these dynamics are disrupted by major surgery and critical illness. In this work, we characterize the inflammatory, ACTH and cortisol responses of patients undergoing cardiac surgery and show that the HPA axis response can be classified into one of three phenotypes: single-pulse, two-pulse and multiple-pulse dynamics. We develop a mathematical model of cortisol secretion and metabolism that predicts the physiological mechanisms responsible for these different phenotypes. We show that the effects of inflammatory mediators are important only in the single-pulse pattern in which normal pulsatility is lost-suggesting that this phenotype could be indicative of the greatest inflammatory response. Investigating whether and how these phenotypes are correlated with clinical outcomes will be critical to patient prognosis and designing interventions to improve recovery.


Assuntos
Procedimentos Cirúrgicos Cardíacos , Sistema Hipófise-Suprarrenal , Hormônio Adrenocorticotrópico/metabolismo , Hormônio Adrenocorticotrópico/farmacologia , Estado Terminal , Humanos , Hidrocortisona/metabolismo , Hidrocortisona/farmacologia , Sistema Hipotálamo-Hipofisário/metabolismo , Inflamação , Sistema Hipófise-Suprarrenal/metabolismo
10.
J R Soc Interface ; 16(159): 20190311, 2019 10 31.
Artigo em Inglês | MEDLINE | ID: mdl-31594522

RESUMO

Senescent cells provide a good in vitro model to study ageing. However, cultures of 'senescent' cells consist of a mix of cell subtypes (proliferative, senescent, growth-arrested and apoptotic). Determining the proportion of senescent cells is crucial for studying ageing and developing new anti-degenerative therapies. Commonly used markers such as doubling population, senescence-associated ß-galactosidase, Ki-67, γH2AX and TUNEL assays capture diverse and overlapping cellular populations and are not purely specific to senescence. A newly developed dynamical systems model follows the transition of an initial culture to senescence tracking population doubling, and the proportion of cells in proliferating, growth-arrested, apoptotic and senescent states. Our model provides a parsimonious description of transitions between these states accruing towards a predominantly senescent population. Using a genetic algorithm, these model parameters are well constrained by an in vitro human primary fibroblast dataset recording five markers at 16 time points. The computational model accurately fits to the data and translates these joint markers into the first complete description of the proportion of cells in different states over the lifetime. The high temporal resolution of the dataset demonstrates the efficacy of strategies for reconstructing the trajectory towards replicative senescence with a minimal number of experimental recordings.


Assuntos
Senescência Celular/fisiologia , Simulação por Computador , Fibroblastos/metabolismo , Modelos Biológicos , Fibroblastos/citologia , Humanos
11.
Ann Thorac Surg ; 87(1): 211-4, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19101299

RESUMO

BACKGROUND: The contribution of ABO blood group mismatching on the rate of cardiac homograft failure is uncertain. It has been shown that there is lack of expression of A and B blood group antigens on fresh and cryopreserved homograft valves. However, expression of these antigens on the homograft vessel conduit has not been reported. METHODS: Unused portions of cryopreserved pulmonary artery homografts (n = 16) were immunohistochemically stained and examined for expression of endothelial cell marker CD31 and A and B blood group antigens. The staining pattern for each antigen was described. Comparison of homograft donor blood group (as determined by immunostaining) to the blood group reported by the homograft supplier was made. RESULTS: Staining of CD31 and A and B blood group antigens was poor on the luminal surface (tunica intima) of the homograft conduit but strong in the vaso vasorum of the tunica media and adventitia. Homograft donor blood group was consistent with the reported donor blood group in 15 of 16 specimens (4 group A, 3 group B, 8 group O). In one specimen (reported as group O), we detected strong expression of CD31 and A antigen on the endothelium of the vaso vasorum. CONCLUSIONS: Cryopreserved homografts strongly express A and B blood group antigens on well-preserved endothelial surfaces of the medial and adventitial vaso vasorum. The significance of this finding with regard to the immunologic response to mismatched ABO blood group antigens and homograft longevity is uncertain.


Assuntos
Sistema ABO de Grupos Sanguíneos/imunologia , Antígenos de Grupos Sanguíneos/imunologia , Criopreservação , Molécula-1 de Adesão Celular Endotelial a Plaquetas/metabolismo , Artéria Pulmonar , Adolescente , Adulto , Biomarcadores/metabolismo , Antígenos de Grupos Sanguíneos/análise , Criança , Pré-Escolar , Criopreservação/métodos , Feminino , Rejeição de Enxerto/imunologia , Sobrevivência de Enxerto/imunologia , Teste de Histocompatibilidade , Humanos , Imuno-Histoquímica , Lactente , Masculino , Pessoa de Meia-Idade , Molécula-1 de Adesão Celular Endotelial a Plaquetas/imunologia , Valva Pulmonar/imunologia , Valva Pulmonar/transplante , Medição de Risco , Estudos de Amostragem , Sensibilidade e Especificidade , Preservação de Tecido , Transplante Homólogo/imunologia , Adulto Jovem
12.
Med. priv ; 4(3): 59-60, 1988.
Artigo em Espanhol | LILACS | ID: lil-67935

RESUMO

Hemos tratado a cuatro pacientes con Púrpura Trombocitopenica Idiopática Crónica con la dosis masiva de inmunoglobulina humana intravenosa que no habían respondido a ninguno de los tratamientos convencionales incluyendo dos esplenectomizados con recaídas. Todos los pacientes ingresaron con manifestaciones hemorrágicas generalizadas y menos de 20.000 mm 3 plaquetas. Recibieron 100 mg por Kg del producto durante tres días y repetimos la dosis siete días después a la frecuencia de 20 a 40 gotas x min. La respuesta fue excelente. No hubo manifestaciones de intolerancia. La edad varió entre 6 y 28 años: tres mujeres y un hombre. Hasta el momento de la presentación de este trabajo preliminar los pacientes mostraron cifras de plaquetas por encima de 200.000 mm 3, 6 meses después y sin tratamiento alguno, no se observaron efectos colaterales ni manifestaciones de intolerancia en ninguno de los casos


Assuntos
Criança , Adulto , Humanos , Masculino , Feminino , Imunoglobulinas/administração & dosagem , Púrpura Trombocitopênica/terapia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA