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Aging in an individual refers to the temporal change, mostly decline, in the body's ability to meet physiological demands. Biological age (BA) is a biomarker of chronological aging and can be used to stratify populations to predict certain age-related chronic diseases. BA can be predicted from biomedical features such as brain MRI, retinal, or facial images, but the inherent heterogeneity in the aging process limits the usefulness of BA predicted from individual body systems. In this paper, we developed a multimodal Transformer-based architecture with cross-attention which was able to combine facial, tongue, and retinal images to estimate BA. We trained our model using facial, tongue, and retinal images from 11,223 healthy subjects and demonstrated that using a fusion of the three image modalities achieved the most accurate BA predictions. We validated our approach on a test population of 2,840 individuals with six chronic diseases and obtained significant difference between chronological age and BA (AgeDiff) than that of healthy subjects. We showed that AgeDiff has the potential to be utilized as a standalone biomarker or conjunctively alongside other known factors for risk stratification and progression prediction of chronic diseases. Our results therefore highlight the feasibility of using multimodal images to estimate and interrogate the aging process.
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Envelhecimento , Fontes de Energia Elétrica , Humanos , Face , Biomarcadores , Doença CrônicaRESUMO
Patch-clamp electrophysiological recordings of neuronal activity require a large amount of space and equipment. The technique is difficult to master and not conducive to demonstration to more than a few medical students. Therefore, neurophysiological education is mostly limited to classroom-based pedagogies such as lectures. However, the demonstration of concepts such as changes in membrane potential and ion channel activity is best achieved with hands-on approaches. This article details an in silico activity suitable for large groups of medical students that demonstrates the key concepts in neurophysiology using the LabAXON simulation software. Learning activities in our practical include 1) measurements of voltage and time parameters of the neuronal action potential and its relationship to the Nernst potentials of Na+ and K+; 2) determination of the stimulus threshold to evoke action potentials; 3) demonstration of the refractory period of an action potential; and 4) voltage-clamp experiments to determine the current-voltage relationship of voltage-gated Na+ and K+ channels and the voltage dependence of, and recovery from, inactivation of voltage-gated Na+ channels. We emphasized the accuracy of quantitative measurements as well as the correct use of units. The level of difficulty of the activity can be altered through different multiple choice questions relating to material introduced in the associated lectures. This practical activity is suitable for different class sizes and is adaptable for delivery with online platforms. Student feedback showed that the students felt the activity helped them consolidate their understanding of the lecture material.
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Neurofisiologia , Estudantes de Medicina , Potenciais de Ação , Humanos , Potenciais da Membrana , SódioRESUMO
Practical demonstration of cardiomyocyte function requires substantial preparation, a source of freshly isolated animal hearts, and specialized equipment. Even where such resources are available, it is not conducive for demonstration to any more than a few students at a time. These approaches are also not consistent with the 3R principle (replacement, reduction, and refinement) of ethical use of animals. We present an implementation of the LabHEART software, developed by Donald Bers and Jose Puglisi, for medical students. Prior to the activity, students had lectures covering the physiological and pharmacological aspects of cardiac excitation-contraction (EC) coupling. We used this problem-based activity to help students consolidate their knowledge and to allow a hands-on approach to explore the key features of EC coupling. Students simulate and measure action potentials, intracellular calcium changes, and cardiomyocyte contraction. They also apply drugs that target ion channels (e.g., nifedipine or tetrodotoxin) or sympathetic input (using isoproterenol) and explore changes to EC coupling. Furthermore, by modifying the biophysical parameters of key ion channels involved in the electrical activity of the heart, students also explore the effect of channelopathies such as long QT syndromes. We describe approaches to implement this activity in a flipped classroom format, with recorded lecture materials provided ahead of the practical to facilitate active learning. We also describe our experiences implementing this activity online. The content and difficulty of the activity can be altered to suit individual courses and is also amenable to promote peer-driven learning.
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Laboratórios , Estudantes de Medicina , Animais , Simulação por Computador , Computadores , Humanos , Aprendizagem Baseada em ProblemasRESUMO
Antibiotics are indispensable to infection management. However, use of antibiotics can cause gut microbiota dysbiosis, which has been linked to cognitive impairment by disrupting communication between the gut microbiota and the brain. We conducted a systematic review and meta-analysis on the effects of long-term antibiotic use on cognitive outcomes. We have searched PubMed, Web of Science, Embase, Cochrane Library and Scopus for English publications before March 2023 following the PRISMA guidelines. Screening, data extraction, and quality assessment were performed in duplicate. 960 articles were screened and 16 studies which evaluated the effect of any antibiotic compared to no antibiotics or placebo were included. Case-reports, in vitro and animal studies were excluded. We found that antibiotic use was associated with worse cognitive outcomes with a pooled effect estimate of - 0.11 (95% CI - 0.15, - 0.07, Z = 5.45; P < 0.00001). Subgroup analyses performed on adult vs pediatric patients showed a similar association of antibiotic on cognition in both subgroups. Antibiotic treatment was not associated with worse cognition on subjects with existing cognitive impairment. On the other hand, antibiotic treatment on subjects with no prior cognitive impairment was associated with worse cognitive performance later in life. This calls for future well-designed and well-powered studies to investigate the impact of antibiotics on cognitive performance.
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Antibacterianos , Cognição , Disfunção Cognitiva , Humanos , Antibacterianos/uso terapêutico , Antibacterianos/efeitos adversos , Cognição/efeitos dos fármacos , Disfunção Cognitiva/tratamento farmacológico , Microbioma Gastrointestinal/efeitos dos fármacos , Disbiose , AdultoRESUMO
An intraoperative diagnosis is critical for precise cancer surgery. However, traditional intraoperative assessments based on hematoxylin and eosin (H&E) histology, such as frozen section, are time-, resource-, and labor-intensive, and involve specimen-consuming concerns. Here, we report a near-real-time automated cancer diagnosis workflow for breast cancer that combines dynamic full-field optical coherence tomography (D-FFOCT), a label-free optical imaging method, and deep learning for bedside tumor diagnosis during surgery. To classify the benign and malignant breast tissues, we conducted a prospective cohort trial. In the modeling group (n = 182), D-FFOCT images were captured from April 26 to June 20, 2018, encompassing 48 benign lesions, 114 invasive ductal carcinoma (IDC), 10 invasive lobular carcinoma, 4 ductal carcinoma in situ (DCIS), and 6 rare tumors. Deep learning model was built up and fine-tuned in 10,357 D-FFOCT patches. Subsequently, from June 22 to August 17, 2018, independent tests (n = 42) were conducted on 10 benign lesions, 29 IDC, 1 DCIS, and 2 rare tumors. The model yielded excellent performance, with an accuracy of 97.62%, sensitivity of 96.88% and specificity of 100%; only one IDC was misclassified. Meanwhile, the acquisition of the D-FFOCT images was non-destructive and did not require any tissue preparation or staining procedures. In the simulated intraoperative margin evaluation procedure, the time required for our novel workflow (approximately 3 min) was significantly shorter than that required for traditional procedures (approximately 30 min). These findings indicate that the combination of D-FFOCT and deep learning algorithms can streamline intraoperative cancer diagnosis independently of traditional pathology laboratory procedures.
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Neoplasias da Mama , Aprendizado Profundo , Tomografia de Coerência Óptica , Humanos , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/cirurgia , Neoplasias da Mama/patologia , Tomografia de Coerência Óptica/métodos , Feminino , Estudos Prospectivos , Pessoa de Meia-Idade , Carcinoma Ductal de Mama/diagnóstico por imagem , Carcinoma Ductal de Mama/cirurgia , Carcinoma Ductal de Mama/patologia , Idoso , Adulto , Carcinoma Intraductal não Infiltrante/diagnóstico por imagem , Carcinoma Intraductal não Infiltrante/cirurgia , Carcinoma Intraductal não Infiltrante/patologia , Período IntraoperatórioRESUMO
INTRODUCTION: Previous studies on cardiovascular disease (CVD) death risk in cancer patients mostly focused on overall cancer, age subgroups and single cancers. OBJECTIVES: To assess the CVD death risk in non-metastatic cancer patients at 21 cancer sites. METHODS: A total of 1,672,561 non-metastatic cancer patients from Surveillance, Epidemiology, and End Results (SEER) datebase (1975-2018) were included in this population-based study, with a median follow-up of 12·7 years. The risk of CVD deaths was assessed using proportions, competing-risk regression, absolute excess risks (AERs), and standardized mortality ratios (SMRs). RESULTS: In patients with localized cancers, the proportion of CVD death and cumulative mortality from CVD in the high-competing risk group (14 of 21 unique cancers) surpassed that of primary neoplasm after cancer diagnosis. The SMRs and AERs of CVD were found higher in patients with non-metastatic cancer than the general US population (SMR 1·96 [95 %CI, 1·95-1·97]-19·85[95 %CI, 16·69-23·44]; AER 5·77-210·48), heart disease (SMR 1·94[95 %CI, 1·93-1·95]-19·25[95 %CI, 15·76-23·29]; AER 4·36-159·10) and cerebrovascular disease (SMR 2·05[95 %CI, 2·02-2·08]-24·71[95 %CI, 16·28-35·96]; AER 1·01-37·44) deaths. In the high-competing risk group, CVD-related SMR in patients with localized stage cancer increased with survival time but followed a reverse-dipper pattern in the low-competing risk group (7 of 21 cancers). The high-competing risk group had higher CVD-related death risks than the low-competing risk group. CONCLUSION: The CVD death risk in patients with non-metastatic cancer varied by cancer stage, site and survival time. The risk of CVD mortality is higher in 14 out of 21 localized cancers (high-competing cancers). Targeted strategies for CVD management in non-metastatic cancer patients are needed.
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Flickering light stimulation has emerged as a promising non-invasive neuromodulation strategy to alleviate neuropsychiatric disorders. However, the lack of a neurochemical underpinning has hampered its therapeutic development. Here, we demonstrate that light flickering triggered an immediate and sustained increase (up to 3 h after flickering) in extracellular adenosine levels in the primary visual cortex (V1) and other brain regions, as a function of light frequency and intensity, with maximal effects observed at 40 Hz frequency and 4000 lux. We uncovered cortical (glutamatergic and GABAergic) neurons, rather than astrocytes, as the cellular source, the intracellular adenosine generation from AMPK-associated energy metabolism pathways (but not SAM-transmethylation or salvage purine pathways), and adenosine efflux mediated by equilibrative nucleoside transporter-2 (ENT2) as the molecular pathway responsible for extracellular adenosine generation. Importantly, 40 Hz (but not 20 and 80 Hz) light flickering for 30 min enhanced non-rapid eye movement (non-REM) and REM sleep for 2-3 h in mice. This somnogenic effect was abolished by ablation of V1 (but not superior colliculus) neurons and by genetic deletion of the gene encoding ENT2 (but not ENT1), but recaptured by chemogenetic inhibition of V1 neurons and by focal infusion of adenosine into V1 in a dose-dependent manner. Lastly, 40 Hz light flickering for 30 min also promoted sleep in children with insomnia by decreasing sleep onset latency, increasing total sleep time, and reducing waking after sleep onset. Collectively, our findings establish the ENT2-mediated adenosine signaling in V1 as the neurochemical basis for 40 Hz flickering-induced sleep and unravel a novel and non-invasive treatment for insomnia, a condition that affects 20% of the world population.
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Distúrbios do Início e da Manutenção do Sono , Humanos , Criança , Animais , Camundongos , Sono , Transdução de Sinais , Adenosina , AstrócitosRESUMO
The SARS-CoV-2 Omicron BA.1 variant of concern contains more than 30 mutations in the spike protein, with half of these mutations localized in the receptor-binding domain (RBD). Emerging evidence suggests that these large number of mutations impact the neutralizing efficacy of vaccines and monoclonal antibodies. We investigated the relative contributions of spike protein and RBD mutations in Omicron BA.1 variants on infectivity, cell-cell fusion, and their sensitivity to neutralization by monoclonal antibodies or vaccinated sera from individuals who received homologous (CoronaVac, SinoPharm) or heterologous (CoronaVac-BNT162b2, BioNTech) and nonhuman primates that received a recombinant RBD protein vaccine. Our data overall reveal that the mutations in the spike protein reduced infectivity and cell-cell fusion compared to the D614G variant. The impaired infectivity and cell-cell fusion were dependent on non-RBD mutations. We also find reduced sensitivity to neutralization by monoclonal antibodies and vaccinated sera. However, our results also show that nonhuman primates receiving a recombinant RBD protein vaccine show substantial neutralization activity. Our study sheds light on the molecular differences in neutralizing antibody escape by the Omicron BA.1 variant, and highlights the promise of recombinant RBD vaccines in neutralizing the threat posed by the Omicron BA.1 variant.
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Expression of mutant Huntingtin (HTT) protein is central to the pathophysiology of Huntington's Disease (HD). The E3 ubiquitin ligase MID1 appears to have a key role in facilitating translation of the mutant HTT mRNA suggesting that interference with the function of this complex could be an attractive therapeutic approach. Here we describe a peptide that is able to disrupt the interaction between MID1 and the α4 protein, a regulatory subunit of protein phosphatase 2A (PP2A). By fusing this peptide to a sequence from the HIV-TAT protein we demonstrate that the peptide can disrupt the interaction within cells and show that this results in a decrease in levels of ribosomal S6 phosphorylation and HTT expression in cultures of cerebellar granule neurones derived from HdhQ111/Q7 mice. This data serves to validate this pathway and paves the way for the discovery of small molecule inhibitors of this interaction as potential therapies for HD.
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Proteína Huntingtina/metabolismo , Neurônios/metabolismo , Proteínas/metabolismo , Animais , Células HEK293 , Humanos , Proteína Huntingtina/genética , Camundongos , Mutação , Cultura Primária de Células , Ligação Proteica , Proteína Fosfatase 2/metabolismo , Ubiquitina-Proteína LigasesRESUMO
Catching primal functional changes in early, 'very far from disease onset' (VFDO) stages of Huntington's disease is likely to be the key to a successful therapy. Focusing on VFDO stages, we assessed neuronal microcircuits in premanifest Hdh150 knock-in mice. Employing in vivo two-photon Ca2+ imaging, we revealed an early pattern of circuit dysregulation in the visual cortex - one of the first regions affected in premanifest Huntington's disease - characterized by an increase in activity, an enhanced synchronicity and hyperactive neurons. These findings are accompanied by aberrations in animal behavior. We furthermore show that the antidiabetic drug metformin diminishes aberrant Huntingtin protein load and fully restores both early network activity patterns and behavioral aberrations. This network-centered approach reveals a critical window of vulnerability far before clinical manifestation and establishes metformin as a promising candidate for a chronic therapy starting early in premanifest Huntington's disease pathogenesis long before the onset of clinical symptoms.
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Comportamento Animal , Córtex Cerebral/fisiopatologia , Doença de Huntington/fisiopatologia , Metformina/farmacologia , Rede Nervosa/fisiopatologia , Animais , Astrócitos/efeitos dos fármacos , Astrócitos/metabolismo , Comportamento Animal/efeitos dos fármacos , Caenorhabditis elegans/efeitos dos fármacos , Cálcio/metabolismo , Respiração Celular/efeitos dos fármacos , Córtex Cerebral/efeitos dos fármacos , Modelos Animais de Doenças , Proteína Huntingtina/metabolismo , Doença de Huntington/patologia , Cinética , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Proteínas Mutantes/metabolismo , Rede Nervosa/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Fótons , Agregados Proteicos/efeitos dos fármacos , Biossíntese de Proteínas , Imagem com Lapso de TempoRESUMO
In the mammalian central nervous system (CNS) GABAA receptors (GABAARs) mediate neuronal inhibition and are important therapeutic targets. GABAARs are composed of 5 subunits, drawn from 19 proteins, underpinning expression of 20-30 GABAAR subtypes. In the CNS these isoforms are heterogeneously expressed and exhibit distinct physiological and pharmacological properties. We report the discovery of S44819, a novel tricyclic oxazolo-2,3-benzodiazepine-derivative, that selectively inhibits α5-subunit-containing GABAARs (α5-GABAARs). Current α5-GABAAR inhibitors bind to the "benzodiazepine site". However, in HEK293 cells expressing recombinant α5-GABAARs, S44819 had no effect on 3H-flumazenil binding, but displaced the GABAAR agonist 3H-muscimol and competitively inhibited the GABA-induced responses. Importantly, we reveal that the α5-subunit selectivity is uniquely governed by amino acid residues within the α-subunit F-loop, a region associated with GABA binding. In mouse hippocampal CA1 neurons, S44819 enhanced long-term potentiation (LTP), blocked a tonic current mediated by extrasynaptic α5-GABAARs, but had no effect on synaptic GABAARs. In mouse thalamic neurons, S44819 had no effect on the tonic current mediated by δ-GABAARs, or on synaptic (α1ß2γ2) GABAARs. In rats, S44819 enhanced object recognition memory and reversed scopolamine-induced impairment of working memory in the eight-arm radial maze. In conclusion, S44819 is a first in class compound that uniquely acts as a potent, competitive, selective antagonist of recombinant and native α5-GABAARs. Consequently, S44819 enhances hippocampal synaptic plasticity and exhibits pro-cognitive efficacy. Given this profile, S44819 may improve cognitive function in neurodegenerative disorders and facilitate post-stroke recovery.
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Benzodiazepinas/farmacologia , Antagonistas de Receptores de GABA-A/farmacologia , Nootrópicos/farmacologia , Oxazóis/farmacologia , Receptores de GABA-A/metabolismo , Animais , Ligação Competitiva , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Feminino , Flumazenil/farmacologia , Agonistas de Receptores de GABA-A/farmacologia , Células HEK293 , Humanos , Potenciação de Longa Duração/efeitos dos fármacos , Potenciação de Longa Duração/fisiologia , Masculino , Memória/efeitos dos fármacos , Memória/fisiologia , Camundongos Endogâmicos C57BL , Muscimol/farmacologia , Inibição Neural/efeitos dos fármacos , Inibição Neural/fisiologia , Ratos Sprague-Dawley , Técnicas de Cultura de Tecidos , Ácido gama-Aminobutírico/farmacologiaRESUMO
The magnocellular neurones of the supraoptic nucleus (SON) and paraventricular nucleus release neuropeptide from their axon terminals and also from their dendrites. In the axon terminals, swellings known as Herring bodies are responsible for the degradation of aged, unreleased large dense-cored vesicles (LDCVs) by lysosomes. Dendrites of magnocellular neurones also contain a large number of LDCVs but specialised areas of vesicle degradation have yet to be discovered. Using immunofluorescence labelling for lysosomes in vasopressin-enhanced green fluorescent protein (vasopressin-eGFP) transgenic rats, we found that lysosomes are preferentially located in the centre of the dendrites where there was a high density of vasopressin-eGFP expression. These data suggest that there are local "hot spots", but not specific compartments for vesicle degradation in magnocellular dendrites.