RESUMO
Measuring the dissimilarity of a phylogenetic tree with respect to a reference tree or the hypotheses is a fundamental task in the phylogenetic study. A large number of methods have been proposed to compute the distance between the reference tree and the target tree. Due to the presence of unresolved relationships among the species, it is challenging to obtain a precise and an accurate reference tree for a selected dataset. As a result, the existing tree comparison methods may behave unexpectedly in various scenarios. In this paper, we introduce a novel scoring function, called the deformity index, to quantify the dissimilarity of a tree based on the list of clades of a reference tree. The strength of our proposed method is that it depends on the list of clades that can be acquired either from the reference tree or from the hypotheses. We investigate the distributions of different modules of the deformity index and perform different goodness-of-fit tests to understand the cumulative distribution. Then, we examine, in detail, the robustness as well as the scalability of our measure by performing different statistical tests under various models. Finally, we experiment on different biological datasets and show that our proposed scoring function overcomes the limitations of the conventional methods.
Assuntos
Modelos Genéticos , FilogeniaRESUMO
Estrogen plays a critical role in many physiological processes and exerts profound effects on behavior by regulating neuronal excitability. While estrogen has been established to exert effects on dendritic morphology and excitatory neurotransmission its role in regulating neuronal inhibition is poorly understood. Fast synaptic inhibition in the adult brain is mediated by specialized populations of γ-c aA receptors (GABAARs) that are selectively enriched at synapses, a process dependent upon their interaction with the inhibitory scaffold protein gephyrin. Here we have assessed the role that estradiol (E2) plays in regulating the dynamics of GABAARs and stability of inhibitory synapses. Treatment of cultured cortical neurons with E2 reduced the accumulation of GABAARs and gephyrin at inhibitory synapses. However, E2 exposure did not modify the expression of either the total or the plasma membrane GABAARs or gephyrin. Mechanistically, single-particle tracking revealed that E2 treatment selectively reduced the dwell time and thereby decreased the confinement of GABAARs at inhibitory synapses. Consistent with our cell biology measurements, we observed a significant reduction in amplitude of inhibitory synaptic currents in both cultured neurons and hippocampal slices exposed to E2, while their frequency was unaffected. Collectively, our results suggest that acute exposure of neurons to E2 leads to destabilization of GABAARs and gephyrin at inhibitory synapses, leading to reductions in the efficacy of GABAergic inhibition via a postsynaptic mechanism.
Assuntos
Estradiol/farmacologia , Inibição Neural/efeitos dos fármacos , Receptores de GABA-A/metabolismo , Sinapses/efeitos dos fármacos , Sinapses/metabolismo , Animais , Proteínas de Transporte/farmacologia , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Células Cultivadas , Feminino , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Masculino , Proteínas de Membrana/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Ratos , Transmissão Sináptica/efeitos dos fármacosRESUMO
The TRAF2 and NCK interacting kinase (TNIK) has been proposed to play a role in cytoskeletal organization and synaptic plasticity and has been linked, among others, to neurological disorders. However, target validation efforts for TNIK have been hampered by the limited kinase selectivity of small molecule probes and possible functional compensation in mouse models. Both issues are at least in part due to its close homology to the kinases MINK1 (or MAP4K6) and MAP4K4 (or HGK). As part of our interest in validating TNIK as a therapeutic target for neurological diseases, we set up a panel of biochemical and cellular assays, which are described herein. We then examined the activity of known amino-pyridine-based TNIK inhibitors (1, 3) and prepared structurally very close analogs that lack the ability to inhibit the target. We also developed a structurally orthogonal, naphthyridine-based TNIK inhibitor (9) and an inactive control molecule of the same chemical series. These validated small-molecule probes will enable dissection of the function of TNIK family in the context of human disease biology.
Assuntos
Proteínas Serina-Treonina Quinases/metabolismo , Esquizofrenia/genética , Fator 2 Associado a Receptor de TNF/metabolismo , Bioensaio , Humanos , Estrutura MolecularRESUMO
We propose an extension of the distance matrix methods NJst and ASTRID to infer species trees from incongruent gene trees having Incomplete Lineage Sorting. Both approaches consider the average internode distance (ID) between individual taxa pairs as the distance measure. The measure ID does not use the root of a tree, and thus may not always infer the relative position of a taxon with respect to the root. We define a novel distance measure excess gene leaf count (XL) between individual couplets. The XL measure is computed using the root of a tree. It is proved to be additive, and is shown to infer the relative order of divergence among individual couplets better. We propose a novel method IDXL which uses both the XL and ID measures for species tree construction. IDXL is shown to perform better than NJst and other distance matrix approaches for most of the biological and simulated datasets. Having the same computational complexity as NJst, IDXL can be applied for species tree inference on large-scale biological datasets.
Assuntos
Algoritmos , Biologia Computacional/métodos , Evolução Molecular , Genes , Especiação Genética , Animais , Magnoliopsida/genética , Modelos Genéticos , Filogenia , Vertebrados/genéticaRESUMO
GABA(A) receptors form Cl(-) permeable channels that mediate the majority of fast synaptic inhibition in the brain. The K(+)/Cl(-) cotransporter KCC2 is the main mechanism by which neurons establish low intracellular Cl(-) levels, which is thought to enable GABAergic inhibitory control of neuronal activity. However, the widely used KCC2 inhibitor furosemide is nonselective with antiseizure efficacy in slices and in vivo, leading to a conflicting scheme of how KCC2 influences GABAergic control of neuronal synchronization. Here we used the selective KCC2 inhibitor VU0463271 [N-cyclopropyl-N-(4-methyl-2-thiazolyl)-2-[(6-phenyl-3-pyridazinyl)thio]acetamide] to investigate the influence of KCC2 function. Application of VU0463271 caused a reversible depolarizing shift in E(GABA) values and increased spiking of cultured hippocampal neurons. Application of VU0463271 to mouse hippocampal slices under low-Mg(2+) conditions induced unremitting recurrent epileptiform discharges. Finally, microinfusion of VU0463271 alone directly into the mouse dorsal hippocampus rapidly caused epileptiform discharges. Our findings indicated that KCC2 function was a critical inhibitory factor ex vivo and in vivo.
Assuntos
Hipocampo/fisiologia , Inibidores de Simportadores de Cloreto de Sódio e Potássio/farmacologia , Simportadores/antagonistas & inibidores , Simportadores/fisiologia , Animais , Animais Recém-Nascidos , Células Cultivadas , Células HEK293 , Hipocampo/efeitos dos fármacos , Humanos , Potenciais da Membrana/efeitos dos fármacos , Potenciais da Membrana/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Técnicas de Cultura de Órgãos , Ratos , Ratos Sprague-Dawley , Transmissão Sináptica/efeitos dos fármacos , Transmissão Sináptica/fisiologia , Cotransportadores de K e Cl-RESUMO
BACKGROUND: In patients with acute coronary syndrome (ACS), reduced left ventricular ejection fraction (LVEF) is a known marker for increased mortality. However, the relationship between LVEF measured during index ACS hospitalization and mortality and heart failure (HF) within 1 year are less well-defined. METHODS: We performed a retrospective analysis of 445 participants in the IMMEDIATE Trial who had LVEF measured by left ventriculography or echocardiogram during hospitalization. RESULTS: Adjusting for age and coronary artery disease (CAD) history, lower LVEF was significantly associated with 1-year mortality or hospitalization for HF. For every 5 % LVEF reduction, the hazard ratio [HR] was 1.26 (95 % CI 1.15, 1.38, P < 0.001). Participants with LVEF < 40 % had higher hazard of 1-year mortality or HF hospitalization than those with LVEF > 40 (HR 3.59; 95 % CI 2.05, 6.27, P < 0.001). The HRs for the association of LVEF with the study outcomes were similar whether measured by left ventriculography or by echocardiography, (respectively, HR 1.32; 95 % CI 1.15, 1.51 and 1.21; 95 % CI 1.106, 1.35, interaction P = 0.32) and whether done within 24 h or not within 24 h (respectively, HR 1.28; 95 % CI 1.10, 1.50 and 1.23; 95 % CI 1.10, 1.38, interaction P = 0.67). CONCLUSIONS: Among patients with ACS, lower in-hospital LVEF is associated with increased 1-year mortality or hospitalization for HF, regardless of the method or timing of the LVEF assessment. This has prognostic implications for clinical practice and suggests the possibility of using various methods of LVEF determination in clinical research.
Assuntos
Síndrome Coronariana Aguda/fisiopatologia , Ecocardiografia/métodos , Insuficiência Cardíaca/diagnóstico , Pacientes Internados , Volume Sistólico/fisiologia , Função Ventricular Esquerda/fisiologia , Síndrome Coronariana Aguda/complicações , Síndrome Coronariana Aguda/diagnóstico , Idoso , Método Duplo-Cego , Feminino , Seguimentos , Insuficiência Cardíaca/etiologia , Insuficiência Cardíaca/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Fatores de TempoRESUMO
In schizophrenia, cognitive dysfunction is highly predictive of poor patient outcomes and is not responsive to current medications. Postmortem studies have suggested that cognitive deficits in schizophrenia are correlated with modifications in the number and size of inhibitory synapses. To test if these modifications lead to cognitive deficits, we have created a dominant-negative virus [adeno-associated (AAV)-DN1] that disrupts the clustering of γ-aminobutyric acid type A receptors (GABA(A)Rs) at postsynaptic inhibitory specializations. When injected into the frontal cortex of mice, AAV-DN1 impairs GABA(A)R α2 subunit and GABA transporter 1 (GAT-1) clustering, but increases GABA(A)R α1 subunit clustering on the perisomatic region, with no influence on axon-initial segment clustering. Mice expressing AAV-DN1 have prepulse inhibition deficits and impairments in working memory. Significantly, these behavioral deficits are paralleled by a reduction in electroencephalography γ-power. Collectively, our study provides functional evidence revealing that GABAergic synapses in the prefrontal cortex directly contribute to cognition and γ-power.
Assuntos
Cognição/fisiologia , Dependovirus/genética , Modelos Animais de Doenças , Lobo Frontal/metabolismo , Receptores de GABA-A/metabolismo , Esquizofrenia/metabolismo , Animais , Eletroencefalografia , Proteínas da Membrana Plasmática de Transporte de GABA/metabolismo , Engenharia Genética/métodos , Vetores Genéticos/genética , Imuno-Histoquímica , Camundongos , Esquizofrenia/patologia , Transdução de Sinais/fisiologiaRESUMO
BACKGROUND: Some benefits of glucose-insulin-potassium (GIK) in patients with acute coronary syndromes (ACS) may be from an anti-inflammatory effect. The primary aim of this study was to assess the impact of GIK administration early in the course of ACS on inflammatory marker C-reactive protein (CRP) levels. A secondary aim was to investigate the association between CRP and 30-day infarct size. METHODS AND RESULTS: Retrospective analysis of participants with ACS randomly assigned to GIK or placebo for at least 8 h in the IMMEDIATE Trial biological mechanism cohort (n = 143). High sensitivity CRP (hs-CRP) was measured at emergency department presentation, and 6 and 12 h into infusion. Logarithmically transformed hs-CRP values at 12-hours were lower with GIK vs. placebo (mean =0.65 mg/L in GIK, 0.84 mg/L in placebo), with a marginal trend toward significance (P = 0.053). Furthermore, using mixed models of hs-CRP, time, and study group, there was a significant increase in hs-CRP levels over time, but the rate of change did not differ between treatment arms (P = 0.3). Multivariable analysis showed that an elevation in hs-CRP, measured at 12 h, was an independent predictor of 30-day infarct size (ß coefficient, 6.80; P = 0.04) using sestamibi SPECT imaging. CONCLUSIONS: The results of this study show no significant effect of GIK on hs-CRP. In addition our results show that in patients with ACS, hs-CRP measured as early as 12 h can predict 30-day infarct size.
Assuntos
Síndrome Coronariana Aguda/sangue , Síndrome Coronariana Aguda/tratamento farmacológico , Proteína C-Reativa/metabolismo , Soluções Cardioplégicas/administração & dosagem , Idoso , Biomarcadores/sangue , Método Duplo-Cego , Feminino , Glucose/administração & dosagem , Humanos , Infusões Intravenosas , Insulina/administração & dosagem , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/sangue , Infarto do Miocárdio/tratamento farmacológico , Potássio/administração & dosagem , Estudos Retrospectivos , Fatores de TempoRESUMO
γ-Aminobutyric acid (GABA) is the principal inhibitory neurotransmitter in the adult brain which mediates its rapid effects on neuronal excitability via ionotropic GABAA receptors. GABA levels in the brain are critically dependent upon GABA-aminotransferase (GABA-AT) which promotes its degradation. Vigabatrin, a low-affinity GABA-AT inhibitor, exhibits anticonvulsant efficacy, but its use is limited due to cumulative ocular toxicity. OV329 is a rationally designed, next-generation GABA-AT inhibitor with enhanced potency. We demonstrate that sustained exposure to OV329 in mice reduces GABA-AT activity and subsequently elevates GABA levels in the brain. Parallel increases in the efficacy of GABAergic inhibition were evident, together with elevations in electroencephalographic delta power. Consistent with this, OV329 exposure reduced the severity of status epilepticus and the development of benzodiazepine refractory seizures. Thus, OV329 may be of utility in treating seizure disorders and associated pathologies that result from neuronal hyperexcitability.
Assuntos
4-Aminobutirato Transaminase , Anticonvulsivantes , Benzodiazepinas , Convulsões , Ácido gama-Aminobutírico , Animais , Anticonvulsivantes/farmacologia , Anticonvulsivantes/administração & dosagem , Masculino , Benzodiazepinas/farmacologia , 4-Aminobutirato Transaminase/antagonistas & inibidores , 4-Aminobutirato Transaminase/metabolismo , Convulsões/tratamento farmacológico , Convulsões/metabolismo , Ácido gama-Aminobutírico/metabolismo , Camundongos Endogâmicos C57BL , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Inibição Neural/efeitos dos fármacos , Inibição Neural/fisiologia , Camundongos , Eletroencefalografia , Modelos Animais de Doenças , Estado Epiléptico/tratamento farmacológico , Estado Epiléptico/induzido quimicamente , Estado Epiléptico/metabolismo , FemininoRESUMO
BACKGROUND: Anemia during pregnancy can complicate maternal and neonatal health and even lead to fatal consequences if not diagnosed early on. Around 99% of women who face maternal mortality are from middle or low-income countries. Early screening of anemia could facilitate improved health outcomes in pregnant women. Point of care techniques are preferred due to their ability to provide results rapidly and because they can be used by personnel with minimal or no training. Such techniques are especially useful in resource-constrained settings like rural parts of developing countries. OBJECTIVES: The aim of the study was to develop a tool using an Artificial Neural Network (ANN) to estimate hemoglobin values using color information recorded from blood sample images. Our method utilizes inexpensive consumables and a simple image acquisition setup that can be assembled easily. METHODS: This study explores a neural network model to estimate the hemoglobin content in an individual's blood sample. Blood samples were collected from 86 volunteers and the images of blood drops were obtained using an image acquisition setup designed by the team. The color intensity values calculated from the blood drop images were used as feature descriptors for the samples. The features obtained from our samples were consequently fed to the Artificial Neural Network. RESULTS: Our neural network that gives the best result has the architecture of 11 neurons in each of the 5 layers. The best model gave estimated hemoglobin levels by analyzing color of blood samples with an accuracy of ±1.8 g/dl Limits of agreement (LOA) and bias 0.03 g/dl (with mean error of 0.75 g/dl). The model was subsequently tested with a validation set prepared from an additional 65 samples. The estimated hemoglobin levels gave an accuracy of +2 g/dl to -1.9 g/dl Limits of agreement (LOA) and bias 0.06 g/dl (with mean error of 0.78 g/dl). CONCLUSION: Optimization of sensitivity and specificity has been able to achieve the sensitivity and specificity values as 95.5% and 52% respectively. These results are at par with the contemporary measurement techniques indicating that our method can be used as a workable screening technique itself.
Assuntos
Anemia , Recém-Nascido , Humanos , Feminino , Gravidez , Anemia/diagnóstico por imagem , Hemoglobinas/análise , Sensibilidade e Especificidade , Programas de RastreamentoRESUMO
The majority of fast synaptic inhibition in the brain is mediated by benzodiazepine-sensitive α1-subunit-containing GABA type A receptors (GABA(A)Rs); however, our knowledge of the mechanisms neurons use to regulate their synaptic accumulation is rudimentary. Using immunoprecipitation, we demonstrate that GABA(A)Rs and gephyrin are intimately associated at inhibitory synapses in cultured rat neurons. In vitro we reveal that the E-domain of gephyrin directly binds to the α1 subunit with an affinity of â¼20 µm, mediated by residues 360-375 within the intracellular domain of this receptor subunit. Mutating residues 360-375 decreases both the accumulation of α1-containing GABA(A)Rs at gephyrin-positive inhibitory synapses in hippocampal neurons and the amplitude of mIPSCs. We also demonstrate that the affinity of gephyrin for the α1 subunit is modulated by Thr375, a putative phosphorylation site. Mutation of Thr375 to a phosphomimetic, negatively charged amino acid decreases both the affinity of the α1 subunit for gephyrin, and therefore receptor accumulation at synapses, and the amplitude of mIPSCs. Finally, single-particle tracking reveals that gephyrin reduces the diffusion of α1-subunit-containing GABA(A)Rs specifically at inhibitory synapses, thereby increasing their confinement at these structures. Our results suggest that the direct binding of gephyrin to residues 360-375 of the α1 subunit and its modulation are likely to be important determinants for the stabilization of GABA(A)Rs at synaptic sites, thereby modulating the strength of synaptic inhibition.
Assuntos
Proteínas de Transporte/metabolismo , Proteínas de Membrana/metabolismo , Inibição Neural/fisiologia , Receptores de GABA-A/metabolismo , Sinapses/metabolismo , Animais , Calorimetria/métodos , Proteínas de Transporte/genética , Células Cultivadas , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Embrião de Mamíferos , Feminino , Hipocampo/citologia , Potenciais Pós-Sinápticos Inibidores/genética , Potenciais Pós-Sinápticos Inibidores/fisiologia , Masculino , Proteínas de Membrana/genética , Camundongos , Microscopia Confocal , Mutação , Neurônios/classificação , Neurônios/fisiologia , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Técnicas de Patch-Clamp , Ligação Proteica/genética , Ligação Proteica/fisiologia , Ratos , Receptores de GABA-A/genética , Treonina/genética , Treonina/metabolismo , Transfecção/métodos , Técnicas do Sistema de Duplo-Híbrido , Ubiquitina-Proteína LigasesRESUMO
Gephyrin is the major protein determinant for the clustering of inhibitory neurotransmitter receptors. Earlier analyses revealed that gephyrin tightly binds to residues 398-410 of the glycine receptor ß subunit (GlyR ß) and, as demonstrated only recently, also interacts with GABA(A) receptors (GABA(A)Rs) containing the α1, α2, and α3 subunits. Here, we dissect the molecular basis underlying the interactions between gephyrin and GABA(A)Rs containing these α-subunits and compare them to the crystal structure of the gephyrin-GlyR ß complex. Biophysical and biochemical assays revealed that, in contrast to its tight interaction with GlyR ß, gephyrin only loosely interacts with GABA(A)R α2, whereas it has an intermediate affinity for the GABA(A)R α1 and α3 subunits. Despite the wide variation in affinities and the low overall sequence homology among the identified receptor subunits, competition assays confirmed the receptor-gephyrin interaction to be a mutually exclusive process. Selected gephyrin point mutants that critically weaken complex formation with GlyR ß also abolished the GABA(A)R α1 and α3 interactions. Additionally, we identified a common binding motif with two conserved aromatic residues that are central for gephyrin binding. Consistent with the biochemical data, mutations of the corresponding residues within the cytoplasmic domain of α2 subunit-containing GABA(A)Rs attenuated clustering of these receptors at postsynaptic sites in hippocampal neurons. Taken together, our experiments provide key insights regarding similarities and differences in the complex formation between gephyrin and GABA(A)Rs compared with GlyRs and, hence, the accumulation of these receptors at postsynaptic sites.
Assuntos
Proteínas de Transporte/química , Proteínas de Membrana/química , Receptores de GABA-A/metabolismo , Receptores de Glicina/metabolismo , Motivos de Aminoácidos , Animais , Sítios de Ligação , Cloretos/química , Análise por Conglomerados , Ligantes , Modelos Moleculares , Conformação Molecular , Mutação , Ligação Proteica , Mapeamento de Interação de Proteínas , Ratos , Sinapses/metabolismo , Potenciais Sinápticos , Tirosina/químicaRESUMO
BACKGROUND: Advancement in sequencing technology yields a huge number of genomes from a multitude of organisms on our planet. One of the fundamental tasks for processing and analyzing these sequences is to organize them in the existing taxonomic orders. METHODS: Recently, we proposed a novel approach, GenFooT, for taxonomy classification using the concept of genomic footprint (GFP). The technique is further refined and enhanced in this work leading to improved accuracies in the task of taxonomic classification based on various benchmark datasets. GenFooT maps a genome sequence in a 2D coordinate space and extracts features from that representation. It uses two hyper-parameters, namely block size and number of fragments of genomic sequence while computing the feature. In this work, we propose an analysis of choosing values of those parameters adaptively from the sequences. The enhanced version of GenFooT is named GenFooT2. RESULTS: We have tested GenFooT2 on ten different biological datasets of genomic sequences of various organisms belonging to different taxonomy ranks. Our experimental results indicate a 3% improved classification performance of the proposed GenFooT2 featured with a Logistic regression classifier as compared to GenFooT. We also performed the statistical test to compare the performance of GenFooT2 to the state-of-the-art methods including our previous method, GenFooT. CONCLUSION: The experimental results as well as the statistical test exhibit that the performance of the proposed GenFooT2 is significantly better.
Assuntos
Algoritmos , Genômica , Genômica/métodosRESUMO
BACKGROUND: Hypercalcaemia is a serious complication of lung cancer. A quality improvement project (QIP) was designed based on guidance from the American College of Chest Physician and the European Respiratory Society who recommend measuring serum calcium for patients referred with suspected lung cancer. METHOD: Seventy-two patients were included in the initial data to ascertain the delay between referral to the lung cancer pathway and obtaining serum calcium levels as part of the initial work-up. New data were then collected after each intervention (including presentations at weekly respiratory multidisciplinary team meetings, posters within clinical areas and a hospital trust screensaver) to evaluate the delay. RESULTS: Initially, 11.1% (n=8) did not have serum calcium measured at any point; two of which had lung cancer (including one metastatic malignancy). Of those who had serum calcium measured, there was a median delay of 13 days between first suspicion and obtaining serum calcium. After all the interventions were put in place, patients had a median of 7 days' delay (p=0.001). CONCLUSION: This QIP design was based on continued feedback to improve the care of patients suspected of lung cancer. Although there was a significant reduction in delays post-intervention, increasing awareness in the community is suggested to maintain these improvements.
RESUMO
BACKGROUND AND OBJECTIVE: In this study, we have analysed pretreatment positron-emission tomography/ computed tomography (PET/CT) images of head and neck squamous cell carcinoma (HNSCC) patients. We have used a publicly available dataset for our analysis. The clinical features of the patient, PET quantitative parameters, and textural indices from pretreatment PET-CT images are selected for the study. The main objective of the study is to use classifiers to predict the outcome for HNSCC patients and compare the performance of the model with the conventional statistical model (CoxPH). METHODS: We have applied a 40% fixed SUV threshold method for tumour delineation. Clinical features of each patient are provided in the dataset, and other features are calculated using LIFEx software. For predicting the outcome, we have implemented three classifiers - Random Forest classifier, Gradient Boosted Decision tree (GBDT) and Decision tree classifier. We have trained each model using 93 data points and test the model performance using 39 data points. The best model - GBDT is chosen based on the performance metrics. RESULTS: It is observed that typically three features: MTV (Metabolic tumour Volume), primary tumour site and GLCM_correlation are significant for prediction of survival outcome. For testing cohort, GBDT achieves a balanced accuracy of 88%, where conventional statistical model reported a balanced accuracy of 81.5%. CONCLUSIONS: The proposed classifier achieves higher accuracy than the state of the art technique. Using this classifier we can estimate the HNSCC patient's outcome, and depending upon the outcome treatment policy can be selected.
Assuntos
Carcinoma de Células Escamosas , Neoplasias de Cabeça e Pescoço , Carcinoma de Células Escamosas/diagnóstico por imagem , Fluordesoxiglucose F18 , Neoplasias de Cabeça e Pescoço/diagnóstico por imagem , Humanos , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Tomografia por Emissão de Pósitrons , Compostos Radiofarmacêuticos , Carcinoma de Células Escamosas de Cabeça e Pescoço/diagnóstico por imagemRESUMO
Loss of glutamatergic synapses is thought to be a key cellular pathology associated with neuropsychiatric disorders including schizophrenia (SCZ) and major depressive disorder (MDD). Genetic and cellular studies of SCZ and MDD using in vivo and in vitro systems have supported a key role for dysfunction of excitatory synapses in the pathophysiology of these disorders. Recent clinical studies have demonstrated that the estrogen, 17ß-estradiol can ameliorate many of the symptoms experienced by patients. Yet, to date, our understanding of how 17ß-estradiol exerted these beneficial effects is limited. In this study, we have tested the hypothesis that 17ß-estradiol can restore dendritic spine number in a cellular model that recapitulates the loss of synapses associated with SCZ and MDD. Ectopic expression of wildtype, mutant or shRNA-mediated knockdown of Disrupted in Schizophrenia 1 (DISC1) reduced dendritic spine density in primary cortical neurons. Acute or chronic treatment with 17ß-estradiol increased spine density to control levels in neurons with altered DISC1 levels. In addition, 17ß-estradiol reduced the extent to which ectopic wildtype and mutant DISC1 aggregated. Furthermore, 17ß-estradiol also caused the enrichment of synaptic proteins at synapses and increased the number of dendritic spines containing PSD-95 or that overlapped with the pre-synaptic marker bassoon. Taken together, our data indicates that estrogens can restore lost excitatory synapses caused by altered DISC1 expression, potentially through the trafficking of DISC1 and its interacting partners. These data highlight the possibility that estrogens exert their beneficial effects in SCZ and MDD in part by modulating dendritic spine number.
Assuntos
Transtorno Depressivo Maior , Estradiol , Espinhas Dendríticas , Estradiol/farmacologia , Estrogênios , Humanos , SinapsesRESUMO
Classical benzodiazepine sensitive GABA(A) receptor subtypes, the major mediators of fast synaptic inhibition in the brain are heteropentamers that can be assembled from alpha1-3/5, beta1-3, and gamma2 subunits, but how neurons orchestrate their selective accumulation at synapses remains obscure. We have identified a 10 amino acid hydrophobic motif within the intracellular domain of the alpha2 subunit that regulates the accumulation of GABA(A) receptors at inhibitory synaptic sites on both axon initial segments and dendrites in a mechanism dependent on the inhibitory scaffold protein gephyrin. This motif was sufficient to target CD4 (cluster of differentiation molecule 4) molecules to inhibitory synapses, and was also critical in regulating the direct binding of alpha2 subunits to gephyrin in vitro. Our results thus reveal that the specific accumulation of GABA(A) receptor subtypes containing alpha2 subunits at inhibitory synapses is dependent on their ability to bind gephyrin.
Assuntos
Proteínas de Transporte/metabolismo , Proteínas de Membrana/metabolismo , Inibição Neural/fisiologia , Subunidades Proteicas/metabolismo , Receptores de GABA-A/metabolismo , Sinapses/metabolismo , Motivos de Aminoácidos , Animais , Proteínas de Transporte/genética , Células Cultivadas , Cobaias , Interações Hidrofóbicas e Hidrofílicas , Líquido Intracelular/fisiologia , Proteínas de Membrana/genética , Ligação Proteica/fisiologia , Estrutura Terciária de Proteína , Subunidades Proteicas/genética , Ratos , Receptores de GABA-A/genética , Sinapses/genéticaRESUMO
Mechanisms that regulate early events in the biogenesis of the alpha7 nicotinic acetylcholine receptor (alpha7 AChR) are not well understood. Data presented here show that single amino acid mutations in the cytoplasmic loop of the alpha7 AChR, between position 335 and 343, abolish or attenuate expression of mature pentameric alpha7 AChRs in both human embryonic kidney tsA201 (HEK) and neuronal SH-SY5Y cells. Although the number of mature alpha7 AChRs is increased significantly in the presence of the chaperone protein resistant to inhibitors of cholineesterase-3 in HEK cells, sucrose gradient sedimentation reveals that the vast majority of alpha7 subunits are aggregated or improperly assembled. Transfection of alpha7 AChRs in SH-SY5Y cells, which endogenously express the alpha7 AChR, results in a much larger fraction of subunits assembled into mature AChRs. Thus, efficient assembly of alpha7 AChRs is influenced by several regions of the large cytoplasmic domain, as well perhaps by other parts of its structure, and requires as yet unknown factors not required by other AChR subtypes.
Assuntos
Mutação/genética , Receptores Nicotínicos/genética , Receptores Nicotínicos/metabolismo , Aconitina/análogos & derivados , Aconitina/metabolismo , Sequência de Aminoácidos , Animais , Bungarotoxinas/metabolismo , Linhagem Celular , Galinhas , Expressão Gênica/genética , Humanos , Imunoprecipitação/métodos , Membranas Intracelulares/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Leucina/genética , Neuroblastoma/metabolismo , Neuroblastoma/patologia , Ligação Proteica/efeitos dos fármacos , Radioisótopos/metabolismo , Relação Estrutura-Atividade , Transfecção/métodos , Receptor Nicotínico de Acetilcolina alfa7RESUMO
The advent of cardiovascular diseases as a disease of mass catastrophy, in recent years is alarming. It is expected to spread as an epidemic by 2030. Present methods of determining the health of one's heart include doppler based echocardiogram, MDCT (Multi Detector Computed Tomography), among various other invasive and non-invasive hemodynamic monitoring techniques. These methods require expert supervision and costly clinical set-ups, and cannot be employed by a common individual to perform a self diagnosis of one's cardiac health, unassisted. In this work, the authors propose a novel methodology using impedance cardiography (ICG), for the determination of a person's cardio-vascular health. The recorded ICG signal helps in extraction of features which are used for estimating parameters for cardiac health monitoring. The proposed methodology with the aid of artificial neural network is able to determine Stroke Volume (SV), Left Ventricular End Systolic Volume (LVESV), Left Ventricular End Diastolic Volume (LVEDV), Left Ventricular Ejection Fraction (LVEF), Iso Volumetric Contraction Time (IVCT), Iso Volumetric Relaxation Time (IVRT), Left Ventricular Ejection Time (LVET), Total Systolic Time (TST), Total Diastolic Time (TDT), and Myocardial Performance Index (MPI), with error margins of ±8.9%, ±3.8%, ±1.4%, ±7.8%, ±16.0%, ±9.0%, ±9.7%, ±6.9%, ±6.2%, and ±0.9%, respectively. The proposed methodology could be used in screening of precursors to cardiac ailments, and to keep a check on the cardio-vascular health.
Assuntos
Cardiografia de Impedância/métodos , Ecocardiografia/métodos , Processamento de Imagem Assistida por Computador/métodos , Redes Neurais de Computação , Adulto , Feminino , Hemodinâmica , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
Mesoporous bioactive glass (MBG) has drawn much attention due to its superior surface texture, porosity and bioactive characteristics. Aim of the present study is to synthesize MBG using different surfactants, viz., hexadecyltrimethylamonium(CTAB) (M1), poly-ethylene glycol (PEG) (M2) and pluronic P123 (M3); bioactivity study; and to understand their bone regeneration efficacy in combination with insulin-like growth factors (IGF-1) in animal bone defect model. SBF study revealed the formation of calcium carbonate (CaCO3) and hydroxyapatite (HAp) phase over 14 days. Formation of apatite layer was further confirmed by FTIR, FESEM and EDX analysis. M1 and M2 showed improved crystallinity, while M3 showed slightly decrease in crystalline peak of CaCO3 and enhanced HAp phase. More Ca-P layer formed in M1 and M2 supported the in vivo experiments subsequently. Degree of new bone formation for all MBGs were high, i.e., M1 (80.7⯱â¯2.9%), M2 (74.4⯱â¯2.4%) and M3 (70.1⯱â¯1.9%) compared to BG (66.9⯱â¯1.8%). In vivo results indicated that the materials were non-toxic, biodegradable, biocompatible, and is suitable as bone replacement materials. Thus, we concluded that growth factor loaded MBG is a promising candidate for bone tissue engineering application.