Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 151
Filtrar
1.
Neurophysiol Clin ; 54(3): 102981, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38703488

RESUMO

OBJECTIVES: To evaluate the evolution of interhemispheric coherences (ICo) in background and spindle frequency bands during childhood and use it to identify individuals with corpus callosum dysgenesis (CCd). METHODS: A monocentric cohort of children aged from 0.25 to 15 years old, consisting of 13 children with CCd and 164 without, was analyzed. The ICo of background activity (ICOBckgrdA), sleep spindles (ICOspindles), and their sum (sICO) were calculated. The impact of age, gender, and CC status on the ICo was evaluated, and the sICO was used to discriminate children with or without CCd. RESULTS: ICOBckgrdA, ICOspindles and sICO increased significantly with age without any effect of gender (p < 10-4), in both groups. The regression equations of the different ICo were stronger, with adjusted R2 values of 0.54, 0.35, and 0.57, respectively. The ICo was lower in children with CCd compared to those without CCd (p < 10-4 for all comparisons). The area under the precision recall curves for predicting CCd using sICO was 0.992 with 98.9 % sensitivity and 87.5 % specificity. DISCUSSION: ICo of spindles and background activity evolve in parallel to brain maturation and depends on the integrity of the corpus callosum. sICO could be an effective diagnostic biomarker for screening children with interhemispheric dysfunction.


Assuntos
Agenesia do Corpo Caloso , Eletroencefalografia , Humanos , Criança , Masculino , Feminino , Pré-Escolar , Adolescente , Eletroencefalografia/métodos , Agenesia do Corpo Caloso/fisiopatologia , Agenesia do Corpo Caloso/diagnóstico , Lactente , Corpo Caloso/fisiopatologia , Estudos de Coortes , Ondas Encefálicas/fisiologia
2.
Clin Neurophysiol ; 163: 267-279, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38644110

RESUMO

OBJECTIVE: This study aims to detect the seizure onset, in childhood absence epilepsy, as early as possible. Indeed, interfering with absence seizures with sensory simulation has been shown to be possible on the condition that the stimulation occurs soon enough after the seizure onset. METHODS: We present four variations (two supervised, two unsupervised) of an algorithm designed to detect the onset of absence seizures from 4 scalp electrodes, and compare their performance with that of a state-of-the-art algorithm. We exploit the characteristic shape of spike-wave discharges to detect the seizure onset. Their performance is assessed on clinical electroencephalograms from 63 patients with confirmed childhood absence epilepsy. RESULTS: The proposed approaches succeed in early detection of the seizure onset, contrary to the classical detection algorithm. Indeed, the results clearly show the superiority of the proposed methods for small delays of detection, under 750 ms from the onset. CONCLUSION: The performance of the proposed unsupervised methods is equivalent to that of the supervised ones. The use of only four electrodes makes the pipeline suitable to be embedded in a wearable device. SIGNIFICANCE: The proposed pipelines perform early detection of absence seizures, which constitutes a prerequisite for a closed-loop system.


Assuntos
Eletroencefalografia , Epilepsia Tipo Ausência , Humanos , Epilepsia Tipo Ausência/fisiopatologia , Epilepsia Tipo Ausência/diagnóstico , Eletroencefalografia/métodos , Criança , Feminino , Masculino , Convulsões/fisiopatologia , Convulsões/diagnóstico , Algoritmos , Pré-Escolar , Adolescente
3.
Reprod Toxicol ; 118: 108389, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37142062

RESUMO

The trace element selenium (Se) is essential for the maintenance of spermatogenesis and fertility. A growing volume of evidence shows that Se is necessary for testosterone synthesis, and Se can stimulate Leydig cell proliferation. However, Se can also act as a metalloestrogen, which can mimic estrogen and activate the estrogen receptors. This study aimed to investigate Se effect on estrogen signaling and the epigenetic status of Leydig cells. Mouse Leydig cells (MA-10) were cultured in a medium supplemented with different Se concentrations (4, 8 µM) for 24 h. Next, cells were assessed for morphological and molecular (qRT PCR, western blot, immunofluorescence) analyses. Immunofluorescence revealed strong immunosignal for 5-methylcytosine in both control and treated cells, with a stronger signal in the 8 µM treated group. qRT-PCR confirmed an increased expression of methyltransferase 3 beta (Dnmt3b) in 8 µM cells. Analysis of the expression of γH2AX (a marker for double-stranded DNA breaks) revealed an increase in the DNA breaks in cells exposed to 8 µM Se. Selenium exposure did not affect the expression of canonical estrogen receptors (ERα and ERß), however, an increase in membrane estrogen receptor G-protein coupled (GPER) protein expression was observed.To sum up, in a high concentration (8 µM) Se affects GPER expression (non-genomic estrogen signaling) in Leydig cells possibly via acting on receptor protein and/or its binding. This causes DNA breaks and induces changes in Leydig cell methylation status, especially in de novo methylation which is mediated by Dnmt3b.


Assuntos
Células Intersticiais do Testículo , Selênio , Animais , Masculino , Camundongos , Epigênese Genética , Receptor alfa de Estrogênio/genética , Receptor alfa de Estrogênio/metabolismo , Receptor beta de Estrogênio/genética , Receptor beta de Estrogênio/metabolismo , Estrogênios/metabolismo , Células Intersticiais do Testículo/metabolismo , Metilação , Receptores de Estrogênio/genética , Receptores de Estrogênio/metabolismo , Selênio/toxicidade
4.
Arch Pediatr ; 29(8): 588-593, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36167615

RESUMO

BACKGROUND: One of the worst complications of surgery for spinal deformity is postoperative neurological deficit. Multimodal intraoperative neuromonitoring (IONM) can be used to detect impending neurological injuries. This study aimed to analyze IONM in non-idiopathic scoliosis using a minimally invasive fusionless surgical technique. METHODS: This retrospective, single-center study was performed from 2014 to 2018. Patients with non-idiopathic scoliosis who underwent a minimally invasive fusionless procedure and had at least 2 years of follow-up were included. IONM was performed using a neurophysiological monitoring work station with somatosensory evoked potentials (SSEP) and neurogenic mixed evoked potentials (NMEP). RESULTS: A total of 290 patients were enrolled. The mean age at surgery was 12.9±3 years. The main etiology was central nervous system (CNS) disorders (n=139, 48%). Overall, 35 alerts (11%) in the SSEP and 10 (7%) in the NMEP occurred. There were two neurological deficits with total recovery after 6 months. There were no false negatives in either SSEP or NMEP, although there was one false positive in SSEP and two false positives for NMEP in the group without signal recovery. There was no significant relationship between the incidence of SSEP or NMEP loss and age, body mass index (BMI), number of rods used, upper instrumented vertebrae (p=0.36), lower instrumented vertebrae, or type of surgery. A preoperative greater Cobb angle was associated with a significantly higher risk of NMEP loss (p=0.02). In CNS patients, a higher BMI was associated with a statistically significant risk of NMEP loss (p=0.004). The use of a traction table was associated with a higher risk of signal loss (p=0.0005). CONCLUSION: A preoperative higher Cobb angle and degree of correction were associated with a significant risk of NMEP loss. In CNS scoliosis, a higher BMI was associated with a significant risk of NMEP loss. The use of a traction table was associated with a higher risk of signal loss.


Assuntos
Escoliose , Criança , Humanos , Adolescente , Escoliose/diagnóstico , Escoliose/cirurgia , Estudos Retrospectivos , Potenciais Somatossensoriais Evocados/fisiologia , Procedimentos Neurocirúrgicos/métodos
5.
Anal Chim Acta ; 1177: 338784, 2021 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-34482902

RESUMO

In this study, two approaches to salivary glands studies are presented: Raman imaging (RI) of tissue cross-section and surface-enhanced Raman spectroscopy (SERS) of tissue homogenates prepared according to elaborated protocol. Collected and analyzed data demonstrate the significant potential of SERS combined with multivariate analysis for distinguishing carcinoma or tumor from the normal salivary gland tissues as a rapid, label-free tool in cancer detection in oncological diagnostics. Raman imaging allows a detailed analysis of the cell wall's chemical composition; thus, the compound's distribution can be semi-quantitatively analyzed, while SERS of tissue homogenates allow for detailed analysis of all moieties forming these tissues. In this sense, SERS is more sensitive and reliable to study any changes in the area of infected tissues. Principal component analysis (PCA), as an unsupervised pattern recognition method, was used to identify the differences in the SERS salivary glands homogenates. The partial least squares-discriminant analysis (PLS-DA), the supervised pattern classification technique, was also used to strengthen further the computed model based on the latent variables in the SERS spectra. Moreover, the chemometric quantification of obtained data was analyzed using principal component regression (PCR) multivariate calibration. The presented data prove that the PCA algorithm allows for 91% in seven following components and the determination between healthy and tumor salivary gland homogenates. The PCR and PLS-DA methods predict 90% and 95% of the variance between the studied groups (in 6 components and 4 factors, respectively). Moreover, according to calculated RMSEC (RMSEP), R2C (R2P) values and correlation accuracy (based on the ROC curve), the PLS-DA model fits better for the studied data. Thus, SERS methods combined with PLS-DA analysis can be used to differentiate healthy, neoplastic, and mixed tissues as a competitive tool in relation to the commonly used method of histopathological staining of tumor tissue.


Assuntos
Carcinoma , Análise Espectral Raman , Análise Discriminante , Humanos , Análise dos Mínimos Quadrados , Análise de Componente Principal
6.
Clin Neurophysiol ; 132(5): 1126-1137, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33773177

RESUMO

OBJECTIVE: We aimed to describe epilepsy and EEG patterns related to vigilance states and age, in chromosome15-long-arm-duplication-syndrome (dup15q) children with epilepsy, in both duplication types: interstitial (intdup15) and isodicentric (idic15). METHODS: Clinical data and 70 EEGs of 12 patients (5 intdup15, 7 idic15), followed from 4.5 m.o to 17y4m (median follow-up 8y3m), were retrospectively reviewed. EEGs were analyzed visually and using power spectrum analysis. RESULTS: Seventy video-EEGs were analyzed (1-16 per patient, median 6), follow-up lasting up to 8y10m (median 4y2m): 25 EEGs in intdup15 (8 m.o to 12y.o, median 4y6m) and 45 EEGs in idic15 (7 m.o to 12 y.o, median 15 m). Epilepsy: 6 West syndrome (WS) (2intdup15, 4idic15); 4 Lennox-Gastaut syndromes (LGS) (1 intdup15, 3 idic15), 2 evolving from WS; focal epilepsy (3 intdup15). In idic15, WS displayed additional myoclonic seizures (3), atypical (4) or no hypsarrhythmia (2) and posterior predominant spike and polyspike bursts (4). Beta-band rapid-rhythms (RR): present in 11 patients, power decreased during non-REM-sleep, localization shifted from diffuse to anterior, peak frequency increased with age. CONCLUSION: WS with peculiar electro-clinical features and LGS, along with beta-band RR decreasing in non-REM-sleep and shifting from diffuse to anterior localization with age are recognizable features pointing towards dup15q diagnosis in children with autism spectrum disorder and developmental delay. SIGNIFICANCE: This study describes electroclinical features in both interstitial and isodicentric duplications of chromosome 15q, in epileptic children, including some recent extensions regarding sleep features; and illustrates how the temporo-spatial organization of beta oscillations can be of significant help in directing towards dup15q diagnosis hypothesis.


Assuntos
Ritmo beta , Transtornos Cromossômicos/fisiopatologia , Epilepsia/fisiopatologia , Deficiência Intelectual/fisiopatologia , Trissomia/fisiopatologia , Adolescente , Criança , Pré-Escolar , Aberrações Cromossômicas , Cromossomos Humanos Par 15 , Epilepsia/genética , Feminino , Humanos , Lactente , Masculino , Sono , Vigília
7.
Int Ophthalmol ; 41(1): 341-347, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32914277

RESUMO

PURPOSE: Animal studies suggest that gut bacteria metabolites are involved in regulation of intraocular pressure or development of glaucoma. However, clinical data are lacking. Here, we wanted to compare level of trimethylamine (TMA), an uremic toxin produced by gut bacteria, along with betaine and trimethylamine N-oxide (TMAO), a substrate and a product of its metabolism, in the aqueous humor and in plasma of patients with glaucoma and their controls. METHODS: Twenty patients were selected for cataract phacoemulsification, and 20 patients selected for phacotrabeculectomy were enrolled in the study. Patients were matched with controls on systemic diseases and estimated glomerular filtration rate. Blood samples were collected in the preoperative suite, whereas aqueous humor samples were collected as the first step of both procedures. Subsequently, level of betaine, TMA and TMAO was analyzed by means of chromatography. RESULTS: In the aqueous humor, level of TMA, but not betaine or TMAO, was significantly higher in the phacotrabeculectomy group than in the phacoemulsification group. Plasma level of betaine, TMA and TMAO was similar between groups. In both groups, level of betaine and TMA, but not TMAO, was significantly higher in plasma than in the aqueous humor. CONCLUSION: TMA, but not TMAO or betaine level, is increased in the aqueous humor of patients with glaucoma. TMA might play a role in pathogenesis of glaucoma; however, prospective studies are needed to confirm our findings.


Assuntos
Microbioma Gastrointestinal , Glaucoma , Animais , Humor Aquoso , Bactérias , Humanos , Metilaminas , Projetos Piloto , Estudos Prospectivos
8.
EJNMMI Phys ; 7(1): 44, 2020 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-32607664

RESUMO

PURPOSE: In living organisms, the positron-electron annihilation (occurring during the PET imaging) proceeds in about 30% via creation of a metastable ortho-positronium atom. In the tissue, due to the pick-off and conversion processes, over 98% of ortho-positronia annihilate into two 511 keV photons. In this article, we assess the feasibility for reconstruction of the mean ortho-positronium lifetime image based on annihilations into two photons. The main objectives of this work include the (i) estimation of the sensitivity of the total-body PET scanners for the ortho-positronium mean lifetime imaging using 2γ annihilations and (ii) estimation of the spatial and time resolution of the ortho-positronium image as a function of the coincidence resolving time (CRT) of the scanner. METHODS: Simulations are conducted assuming that radiopharmaceutical is labeled with 44Sc isotope emitting one positron and one prompt gamma. The image is reconstructed on the basis of triple coincidence events. The ortho-positronium lifetime spectrum is determined for each voxel of the image. Calculations were performed for cases of total-body detectors build of (i) LYSO scintillators as used in the EXPLORER PET and (ii) plastic scintillators as anticipated for the cost-effective total-body J-PET scanner. To assess the spatial and time resolution, the four cases were considered assuming that CRT is equal to 500 ps, 140 ps, 50 ps, and 10 ps. RESULTS: The estimated total-body PET sensitivity for the registration and selection of image forming triple coincidences (2γ+γprompt) is larger by a factor of 13.5 (for LYSO PET) and by factor of 5.2 (for plastic PET) with respect to the sensitivity for the standard 2γ imaging by LYSO PET scanners with AFOV = 20 cm. The spatial resolution of the ortho-positronium image is comparable with the resolution achievable when using TOF-FBP algorithms already for CRT = 50 ps. For the 20-min scan, the resolution better than 20 ps is expected for the mean ortho-positronium lifetime image determination. CONCLUSIONS: Ortho-positronium mean lifetime imaging based on the annihilations into two photons and prompt gamma is shown to be feasible with the advent of the high sensitivity total-body PET systems and time resolution of the order of tens of picoseconds.

9.
Poult Sci ; 99(1): 555-566, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32416842

RESUMO

Tight, adherens, and gap junctions are involved in the regulation of reproductive tissue function in male mammals. In birds, including domestic turkeys, intercellular interactions performed by junctional networks have not yet been studied. Furthermore, the cellular and molecular basis of yellow semen syndrome (YSS) in the turkey population remains poorly understood. Thus, the aim of the present study was 2-fold: first, to provide new information on the localization and expression of cell-cell junction proteins in the testis, epididymis, and ductus deferens of domestic turkeys and second, to compare expression of junctional protein genes between 2 turkey population, one that produces white normal semen (WNS) and the other that produces yellow abnormal semen. Expression of occludin, zonula occludens-1 (ZO-1), connexin 43 (Cx43), N- and E-cadherin, and ß-catenin genes were investigated using 3 complementary techniques: quantitative real-time PCR, western blot, and immunohistochemistry. Compared to WNS testis, epididymis, and ductus deferens, YSS tissues exhibited downregulation of occludin and ß-catenin mRNA (P < 0.05) and protein (P < 0.05 and P < 0.01, respectively) and upregulation of N- and E-cadherin mRNA (P < 0.001, P < 0.05, P < 0.01, respectively) and protein (P < 0.01, P < 0.05, and P < 0.05, respectively). In contrast, ZO-1 and Cx43 mRNA and protein were upregulated in YSS testis (P < 0.05 and P < 0.001, respectively) but not in epididymis and ductus deferens; both mRNAs and proteins were downregulated (P < 0.05) compared to the respective WNS epididymis and ductus deferens. Altered staining intensity of immunoreactive proteins in YSS vs. WNS reproductive tissue sections confirmed the gene expression results. The present study is the first to demonstrate altered levels of junctional protein gene expression in reproductive tissues of male YSS turkeys. These findings may suggest that subtle changes in junctional protein expression affect the microenvironment in which spermatozoa develop and mature and thus may have an impact on the appearance of yellow semen in domestic turkeys.


Assuntos
Proteínas Aviárias/genética , Expressão Gênica , Sêmen/fisiologia , Proteínas de Junções Íntimas/genética , Perus/fisiologia , Animais , Proteínas Aviárias/metabolismo , Células Epiteliais/metabolismo , Células Germinativas/metabolismo , Masculino , Células de Sertoli/metabolismo , Proteínas de Junções Íntimas/metabolismo , Perus/genética
10.
Micron ; 134: 102864, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32251927

RESUMO

A multiple-quantum-well structure consisting of 40 periods of AlN/GaN:Si was investigated using a transmission electron microscope equipped with energy-dispersive X-ray spectroscopy. The thicknesses of the AlN barriers and the GaN quantum wells were 4 nm and 6 nm, respectively. The QW layers were doped with Si to a concentration of 1.3×1019cm-3 (0.012 % at). The procedure for quantifying such a doping level using AlN as a standard is presented. The EDS results (0.013 % at) are compared with secondary ion mass spectrometry measurements (0.05 % at).

11.
Spectrochim Acta A Mol Biomol Spectrosc ; 233: 118088, 2020 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-32146423

RESUMO

The surface-enhanced Raman spectroscopy (SERS) is a method known for its effectiveness in detecting and identifying microorganisms, that was employed to differentiate various bacterial strains both at genus and species level. In this work, we have examined five species belonging to Streptococcus genus, namely S. pneumoniae, S. suis, S. pseudopneumoniae, S. oralis, and S. mitis. Additionally, we conducted SERS experiments on ten S. pneumoniae strains, representing different capsular types. In all of cases we obtained unique SERS signals being spectroscopic fingerprints of bacterial strains tested. Moreover, the principal component analysis (PCA) was performed in order to prove that the spectra of all studied strains can be well separated into five (in case of streptococcal strains) or ten (in case of pneumococcal serotypes) groups. In both investigated situations, the separation at the level of 95% was achieved, proving that SERS-PCA-based method can be used for reliable and fast identification of different strains belonging to the Streptococcus genus, including encapsulated pneumococcal isolates.


Assuntos
Parede Celular/química , Sorogrupo , Análise Espectral Raman , Streptococcus pneumoniae , Streptococcus pneumoniae/química , Streptococcus pneumoniae/classificação
12.
Andrology ; 8(2): 457-472, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31468707

RESUMO

BACKGROUND: Notch signaling pathway is involved in contact-dependent communication between the cells of seminiferous epithelium, and its proper activity is important for undisturbed spermatogenesis. OBJECTIVES: The aim was to assess the effect of Notch pathway inhibition on the expression of nuclear (AR) and membrane (ZIP9) androgen receptors and androgen-regulated genes, claudin-5 and claudin-11, in TM4 mouse Sertoli cell line. MATERIALS AND METHODS: DAPT (γ-secretase inhibitor) treatment and recombination signal binding protein silencing were employed to reduce Notch signaling, whereas immobilized ligands were used to activate Notch pathway in TM4 cells. To reveal specific effect of each androgen receptor, AR or ZIP9 silencing was performed. RESULTS: Notch pathway inhibition increased the expression of AR and ZIP9 mRNA and proteins (p < 0.01; p < 0.05) in TM4 cells, whereas incubation with Notch ligands, rDLL1 or rJAG1, reduced AR (p < 0.01; p < 0.001) and ZIP9 (p < 0.05; p < 0.01) expressions, respectively. Testosterone enhanced the expression of both receptors (p < 0.05; p < 0.01). Androgen-regulated claudin-5 and claudin-11 (p < 0.01; p < 0.001) and cAMP (p < 0.001) were elevated in Notch-inhibited cells, while activation of Notch signaling by DLL1 or JAG1 reduced claudin-11 or claudin-5 level (p < 0.01; p < 0.001), respectively. DISCUSSION: Our findings indicate opposite effect of Notch and androgen signaling on the expression of androgen receptors in TM4 cells. We demonstrated that AR expression is regulated by DLL1-mediated Notch signaling, whereas JAG1 is involved in the regulation of ZIP9. The expression of both claudins and cAMP production is under inhibitory influence of Notch pathway. The effects of Notch signaling on claudin-5 and claudin-11 expression are mediated by ZIP9 and AR, respectively. CONCLUSION: Notch signaling may be considered as an important pathway controlling Sertoli cell physiology, and its alterations may contribute to disturbed response of Sertoli cells to androgens.


Assuntos
Proteínas de Transporte de Cátions/metabolismo , Regulação da Expressão Gênica/fisiologia , Receptores Androgênicos/metabolismo , Receptores Notch/metabolismo , Células de Sertoli/metabolismo , Animais , Linhagem Celular , Membrana Celular/metabolismo , Núcleo Celular/metabolismo , Claudina-5/genética , Claudina-5/metabolismo , Claudinas/genética , Claudinas/metabolismo , Masculino , Camundongos , Transdução de Sinais/fisiologia
13.
Handb Clin Neurol ; 160: 125-142, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31277843

RESUMO

EEG changes during the perinatal period, infancy, childhood, and adolescence are concomitant with brain growth, myelination, expanding connectivity, and overall maturation, which are particularly fast during the first year of life. EEG aspects of early brain development are accessible in preterm during the third trimester of gestational age, and they evolve to full-term, infancy, and childhood EEG patterns. Each of these age periods shares specific EEG features that reach gross adult outlines in the first year. Interpreting EEG needs therefore a deep knowledge of pathological and normal EEG patterns with their variants belonging to each age range. Recording EEG during these periods also requires adapting the recording techniques to the specific age in order to obtain interpretable records. This chapter describes normal EEG features and variants, characteristic patterns of development, and some patterns that are unusual for age, from the neonatal period to adolescence.


Assuntos
Encéfalo/crescimento & desenvolvimento , Desenvolvimento Infantil/fisiologia , Eletroencefalografia/métodos , Encéfalo/fisiologia , Criança , Pré-Escolar , Eletroencefalografia/tendências , Humanos , Lactente , Recém-Nascido
14.
Sci Rep ; 9(1): 9267, 2019 06 25.
Artigo em Inglês | MEDLINE | ID: mdl-31239487

RESUMO

Isolation and detection of circulating tumor cells (CTCs) from human blood plays an important role in non- invasive screening of cancer evolution and in predictive therapeutic treatment. Here, we present the novel tool utilizing: (i) the microfluidic device with (ii) incorporated photovoltaic (PV) based SERS-active platform, and (iii) shell-isolated nanoparticles (SHINs) for simultaneous separation and label-free analysis of circulating tumour cells CTCs in the blood specimens with high specificity and sensitivity. The proposed microfluidic chip enables the efficient size - based inertial separation of circulating cancer cells from the whole blood samples. The SERS-active platform incorporated into the microfluidic device permits the label-free detection and identification of isolated cells through the insight into their molecular and biochemical structure. Additionally, the silver nanoparticles coated with an ultrathin shell of silica (Ag@SiO2) was used to improve the detection accuracy and sensitivity of analysed tumor cells via taking advantages of shell-isolated nanoparticle-enhanced Raman spectroscopy (SHINERS). The empirical analysis of SHINERS spectra revealed that there are some differences among studied (HeLa), renal cell carcinoma (Caki-1), and blood cells. Unique SHINERS features and differences in bands intensities between healthy and cancer cells might be associated with the variations in the quantity and quality of molecules such as lipid, protein, and DNA or their structure during the metastasis cancer formation. To demonstrate the statistical efficiency of the developed method and improve the differentiation for circulating tumors cells detection the principal component analysis (PCA) has been performed for all SHINERS data. PCA method has been applied to recognize the most significant differences in SHINERS data among the three analyzed cells: Caki-1, HeLa, and blood cells. The proposed approach challenges the current multi-steps CTCs detection methods in the terms of simplicity, sensitivity, invasiveness, destructivity, time and cost of analysis, and also prevents the defragmentation/damage of tumor cells and thus leads to improving the accuracy of analysis. The results of this research work show the potential of developed SERS based tool for the separation of tumor cells from whole blood samples in a simple and minimally invasive manner, their detection and molecular characterization using one single technology.


Assuntos
Separação Celular/métodos , Dispositivos Lab-On-A-Chip , Nanopartículas Metálicas/química , Neoplasias/patologia , Células Neoplásicas Circulantes/patologia , Análise Espectral Raman/métodos , Ouro/química , Humanos , Prata/química , Células Tumorais Cultivadas
15.
RSC Adv ; 9(2): 576-591, 2019 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-35517626

RESUMO

Surface-enhanced Raman scattering (SERS) has been intensively used recently as a highly sensitive, non-destructive, chemical specific, and label-free technique for a variety of studies. Here, we present a novel SERS substrate for: (i) the standard ultra-trace analysis, (ii) detection of whole microorganisms, and (iii) spectroelectrochemical measurements. The integration of electrochemistry and SERS spectroscopy is a powerful approach for in situ investigation of the structural changes of adsorbed molecules, their redox properties, and for studying the intermediates of the reactions. We have developed a conductive SERS platform based on photovoltaic materials (PV) covered with a thin layer of silver, especially useful in electrochemical SERS analysis. These substrates named Ag/PV presented in this study combine crucial spectroscopic features such as high sensitivity, reproducibility, specificity, and chemical/physical stability. The designed substrates permit the label-free identification and differentiation of cancer cells (renal carcinoma) and pathogens (Escherichia coli and Bacillus subtilis). In addition, the developed SERS platform was adopted as the working electrode in an electrochemical SERS approach for p-aminothiophenol (p-ATP) studies. The capability to monitor in real-time the electrochemical changes spectro-electro-chemically has great potential for broadening the application of SERS.

16.
Phys Chem Chem Phys ; 21(5): 2816-2817, 2019 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-30548031

RESUMO

The temperature dependence of the band-gap energy affects the evaluation of the energy positions of rare-earth 4f levels in relation to the vacuum level. Neglecting this dependence may lead to strongly distorted results.

17.
J Physiol Pharmacol ; 69(3)2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30149370

RESUMO

We tested whether G-coupled membrane estrogen receptor (GPER) and peroxisome proliferator activated receptor (PPAR) partnership exists and whether this interaction regulates mouse Leydig cell function. Mature and aged mice were treated with the antagonist of GPER (G-15; 50 µg/kg b.w). Leydig cells (MA-10) were treated with G-15 (10 nM) alone or in combination with peroxisome proliferator-activated receptor α or γ antagonists, respectively (PPARα, 10 µM; PPARγ, 10 µM). GPER blockage affected testis steroidogenic status via changes in lutropin and cholesterol levels as well as protein expression alterations of the lutropin receptor, acute steroidogenesis activating protein, translocator protein, and protein kinase A in mouse Leydig cells both in vivo and in vitro. Inactivation of both GPER and PPAR in vitro revealed expressional modulation of other steroidogenesis-controlling molecules acting on various steps of lipid homeostasis e.g. cytochrome P450scc, perilipin, hormone sensitive lipase, and 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase. Concomitantly, microscopic analysis of cells treated with antagonists showed changes in morphology, migration competences and cytoskeleton structure. In the above processes, the action of GPER and PPARα was regulated through the PI3K/Akt pathway, while PPARγ was mediated by the Ras/Raf pathway. In addition, GPER and PPARs specifically controlled individual signaling proteins. For the first time, we report here the importance of GPER-PPARα and -PPARγ 'neopartnership' in maintenance of Leydig cell morpho-functional status.


Assuntos
PPAR alfa/metabolismo , PPAR gama/metabolismo , Receptores de Estrogênio/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Testículo/metabolismo , Animais , Benzodioxóis/farmacologia , Linhagem Celular , Movimento Celular , Colesterol/metabolismo , Masculino , Camundongos , Microscopia Eletrônica de Varredura , PPAR alfa/antagonistas & inibidores , PPAR gama/antagonistas & inibidores , Fosfoproteínas/metabolismo , Quinolinas/farmacologia , Receptores de Estrogênio/antagonistas & inibidores , Receptores Acoplados a Proteínas G/antagonistas & inibidores , Receptores de GABA/metabolismo , Receptores do LH/metabolismo , Testículo/efeitos dos fármacos , Testículo/ultraestrutura
18.
Phys Rev E ; 97(6-1): 062120, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30011481

RESUMO

The Lévy walk process for a lower interval of an excursion times distribution (α<1) is discussed. The particle rests between the jumps, and the waiting time is position-dependent. Two cases are considered: a rising and diminishing waiting time rate ν(x), which require different approximations of the master equation. The process comprises two phases of the motion: particles at rest and in flight. The density distributions for them are derived, as a solution of corresponding fractional equations. For strongly falling ν(x), the resting particles density assumes the α-stable form (truncated at fronts), and the process resolves itself to the Lévy flights. The diffusion is enhanced for this case but no longer ballistic, in contrast to the case for the rising ν(x). The analytical results are compared with Monte Carlo trajectory simulations. The results qualitatively agree with observed properties of human and animal movements.

19.
Br Poult Sci ; 59(5): 591-603, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29848062

RESUMO

1. To show hormonal differences between male turkeys with yellow semen syndrome (YSS) and white, normal semen (WNS), the expression of aromatase, oestrogen receptor α (ERα), and oestrogen receptor ß (ERß) as well as testosterone and oestradiol concentrations in YSS and WNS testes, epididymis, and ductus deferens were examined. 2. To measure gene expression levels of aromatase and oestrogen receptors (ERs), three complementary techniques (real-time PCR, Western blot, and immunohistochemistry) were used, whereas steroid hormone levels were determined radio-immunologically. 3. Upregulation of aromatase and ERα mRNAs in YSS testes (P < 0.05; P < 0.01), epididymis (P < 0.001; P < 0.001), and ductus deferens (P < 0.05; P < 0.01) compared to those of WNS tissues was detected. Significant increases in the levels of aromatase and ERα proteins were detected in YSS testes (P < 0.001; P < 0.05), epididymis (P < 0.001; P < 0.001), and ductus deferens (P < 0.001; P < 0.05). The expression of ERß mRNA and protein level was upregulated in the testes (P < 0.05; P < 0.01) and epididymis (P < 0.001; P < 0.01) but not in ductus deferens where it was downregulated (P < 0.01; P < 0.01). Increased intensity of immunoreactive proteins in YSS versus WNS reproductive tissues corroborated gene expression results. 4. Testosterone concentration diminished in YSS epididymis (P < 0.05) and ductus deferens (P < 0.05), but not in the testes, remaining at high level (P < 0.05) compared to WNS values. Concomitantly, increased oestradiol concentration was found in YSS testes (P < 0.05) and epididymis (P < 0.05) but decreased in the ductus deferens (P < 0.05). 5. From the published literature, this study is the first to demonstrate the ability for androgen aromatisation in the turkey reproductive tissues and to show the cellular targets for locally produced oestrogens. The data suggested that the androgen/oestrogen ratio is a mechanistic basis for amplification of differences between turkeys with white and yellow semen and that these results can have a relevance in applied sciences to widen the knowledge on domestic bird reproduction.


Assuntos
Aromatase/genética , Sêmen/química , Perus/fisiologia , Animais , Animais Domésticos/fisiologia , Aromatase/análise , Aromatase/metabolismo , Western Blotting , Epididimo/enzimologia , Estradiol/análise , Hormônios Esteroides Gonadais/análise , Hormônios Esteroides Gonadais/metabolismo , Masculino , Reação em Cadeia da Polimerase em Tempo Real , Receptores de Estrogênio/genética , Reprodução , Sêmen/fisiologia , Testículo/enzimologia , Testosterona/análise , Perus/anatomia & histologia , Regulação para Cima
20.
Cereb Cortex ; 28(10): 3429-3444, 2018 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-29194486

RESUMO

Characteristic preterm EEG patterns of "Delta-brushes" (DBs) have been reported in the temporal cortex following auditory stimuli, but their spatio-temporal dynamics remains elusive. Using 32-electrode EEG recordings and co-registration of electrodes' position to 3D-MRI of age-matched neonates, we explored the cortical auditory-evoked responses (AERs) after 'click' stimuli in 30 healthy neonates aged 30-38 post-menstrual weeks (PMW). (1) We visually identified auditory-evoked DBs within AERs in all the babies between 30 and 33 PMW and a decreasing response rate afterwards. (2) The AERs showed an increase in EEG power from delta to gamma frequency bands over the middle and posterior temporal regions with higher values in quiet sleep and on the right. (3) Time-frequency and averaging analyses showed that the delta component of DBs, which negatively peaked around 550 and 750 ms over the middle and posterior temporal regions, respectively, was superimposed with fast (alpha-gamma) oscillations and corresponded to the late part of the cortical auditory-evoked potential (CAEP), a feature missed when using classical CAEP processing. As evoked DBs rate and AERs delta to alpha frequency power decreased until full term, auditory-evoked DBs are thus associated with the prenatal development of auditory processing and may suggest an early emerging hemispheric specialization.


Assuntos
Audiometria de Resposta Evocada , Córtex Cerebral/fisiologia , Recém-Nascido Prematuro/fisiologia , Estimulação Acústica , Ritmo alfa/fisiologia , Ritmo Delta/fisiologia , Eletroencefalografia , Potenciais Evocados Auditivos/fisiologia , Feminino , Ritmo Gama , Humanos , Recém-Nascido , Imageamento por Ressonância Magnética , Masculino , Sono/fisiologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...