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1.
Bioorg Med Chem ; 104: 117698, 2024 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-38552597

RESUMEN

Serotonin reuptake inhibition combined with the action targeting 5-hydroxytryptamine receptor subtypes can serve as a potential target for the development of antidepressant drugs. Herein a series of new aralkyl piperazines and piperidines were designed and synthesized by the structural modifications of the previously discovered aralkyl piperidine compound 1, targeting SSRI/5-HT1A/5-HT7. The results exhibited that compound 5a showed strong binding to 5-HT1A and 5-HT7 (Ki of 0.46 nM, 2.7 nM, respectively) and a high level of serotonin reuptake inhibition (IC50 of 1.9 nM), all of which were significantly elevated compared to 1. In particular, compound 5a showed weaker inhibitory activity against hERG than 1, and demonstrated good stability in liver microsomes in vitro. The preliminary screening using FST indicated that orally administered 5a, at a high dose, could reduce immobility time in mice markedly, indicating potential antidepressant activity.


Asunto(s)
Inhibidores Selectivos de la Recaptación de Serotonina , Serotonina , Ratones , Animales , Piperazina/farmacología , Serotonina/metabolismo , Inhibidores Selectivos de la Recaptación de Serotonina/farmacología , Antidepresivos/farmacología , Antidepresivos/uso terapéutico , Piperidinas/farmacología , Piperazinas/química , Receptor de Serotonina 5-HT1A
2.
Neuroimage ; 269: 119923, 2023 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-36739101

RESUMEN

BACKGROUND: Microstructural changes in deep gray matter (DGM) nuclei are related to physiological behavior, cognition, and memory. Therefore, it is critical to study age-dependent trajectories of biomarkers in DGM nuclei for understanding brain development and aging, as well as predicting cognitive or neurodegenerative diseases. OBJECTIVES: We aimed to (1) characterize age-dependent trajectories of mean susceptibility, adjusted volume, and total iron content simultaneously in DGM nuclei using quantitative susceptibility mapping (QSM); (2) examine potential contributions of sex related effects to the different age-dependence trajectories of volume and iron deposition; and (3) evaluate the ability of brain age prediction by combining mean magnetic susceptibility and volume of DGM nuclei. METHODS: Magnetic susceptibilities and volumetric values of DGM nuclei were obtained from 220 healthy participants (aged 10-70 years) scanned on a 3T MRI system. Regions of interest (ROIs) were drawn manually on the QSM images. Univariate regression analysis between age and each of the MRI measurements in a single ROI was performed. Pearson correlation coefficients were calculated between magnetic susceptibility and adjusted volume in a single ROI. The statistical significance of sex differences in age-dependent trajectories of magnetic susceptibilities and adjusted volumes were determined using one-way ANCOVA. Multiple regression analysis was used to evaluate the ability to estimate brain age using a combination of the mean susceptibilities and adjusted volumes in multiple DGM nuclei. RESULTS: Mean susceptibility and total iron content increased linearly, quadratically, or exponentially with age in all six DGM nuclei. Negative linear correlation was observed between adjusted volume and age in the head of the caudate nucleus (CN; R2 = 0.196, p < 0.001). Quadratic relationships were found between adjusted volume and age in the putamen (PUT; R2 = 0.335, p < 0.001), globus pallidus (GP; R2 = 0.062, p = 0.001), and dentate nucleus (DN; R2 = 0.077, p < 0.001). Males had higher mean magnetic susceptibility than females in the PUT (p = 0.001), red nucleus (RN; p = 0.002), and substantia nigra (SN; p < 0.001). Adjusted volumes of the CN (p < 0.001), PUT (p = 0.030), GP (p = 0.007), SN (p = 0.021), and DN (p < 0.001) were higher in females than those in males throughout the entire age range (10-70 years old). The total iron content of females was higher than that of males in the CN (p < 0.001), but lower than that of males in the PUT (p = 0.014) and RN (p = 0.043) throughout the entire age range (10-70 years old). Multiple regression analyses revealed that the combination of the mean susceptibility value of the PUT, and the volumes of the CN and PUT had the strongest associations with brain age (R2 = 0.586). CONCLUSIONS: QSM can be used to simultaneously investigate age- and sex- dependent changes in magnetic susceptibility and volume of DGM nuclei, thus enabling a comprehensive understanding of the developmental trajectories of iron accumulation and volume in DGM nuclei during brain development and aging.


Asunto(s)
Encéfalo , Sustancia Gris , Humanos , Masculino , Femenino , Niño , Adolescente , Adulto Joven , Adulto , Persona de Mediana Edad , Anciano , Imagen por Resonancia Magnética/métodos , Envejecimiento , Mapeo Encefálico/métodos , Hierro
3.
Magn Reson Med ; 89(5): 1728-1740, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-36572961

RESUMEN

PURPOSE: The signals of glutamate (Glu) and glutamine (Gln) are often significantly overlapped in routine 1 H-MR spectra of human brain in vivo. Selectively probing the signals of Glu and Gln in vivo is very important for the study of the metabolisms in which Glu and Gln are involved. METHODS: The Glu-/Gln- targeted pulse sequences are developed to selectively probe the signals of Glu and Gln. The core part of the Glu-/Gln- targeted pulse sequences lies on the preparation of the nuclear spin singlet orders (SSOs) of the five-spin systems of Glu and Gln. The optimal control method is used to prepare the SSOs of Glu and Gln with high efficiency. RESULTS: The Glu-/Gln- targeted pulse sequences have been applied on phantoms to selectively probe the signals of Glu and Gln. Moreover, in the in vivo experiments, the signals of Glu and Gln in human brains of healthy subjects have been successfully probed separately. CONCLUSION: The developed Glu-/Gln- targeted pulse sequences can be used to distinguish the 1 H-MR signals of Glu and Gln in human brains in vivo. The optimal control method provides an effective way to prepare the SSO of a specific spin system with high efficiency and in turn selectively probe the signals of a targeted molecule.


Asunto(s)
Ácido Glutámico , Glutamina , Humanos , Glutamina/metabolismo , Ácido Glutámico/metabolismo , Espectroscopía de Resonancia Magnética/métodos , Encéfalo/diagnóstico por imagen , Encéfalo/metabolismo , Fantasmas de Imagen
4.
Phys Rev Lett ; 131(9): 098202, 2023 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-37721830

RESUMEN

Packing structures of granular disks are reconstructed using magnetic resonance imaging techniques. As packing fraction increases, the packing structure transforms from a nematic loose packing to a dense packing with randomly oriented stacks. According to our model based on Edwards' volume ensemble, stack structures are statistically favored when the effective temperature decreases, which has a lower structural anisotropy than single disks, and brings down the global orientational order consequently. This mechanism identified in athermal granular materials can help us understand the nonergodic characteristics of disklike particle assemblies such as discotic mesogens and clays.

5.
J Magn Reson Imaging ; 58(2): 581-590, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-36594513

RESUMEN

BACKGROUND: Deep brain stimulation (DBS) of the subthalamic nucleus (STN) improves motor deficits in advanced Parkinson's disease (PD) patients, but the degree of motor improvement varies across individuals. PD pathology involves the changes of iron spatial distribution in the deep gray matter nuclei. PURPOSE: To explore the relationship between the iron spatial distribution and motor improvement among PD patients who underwent STN-DBS surgery in three regions: substantia nigra (SN), STN, and dentate nucleus (DN). STUDY TYPE: Prospective. SUBJECTS: Forty PD patients (49.7 ± 8.8 years, 22 males/18 females) who underwent bilateral STN-DBS. FIELD STRENGTH/SEQUENCE: A 3 T preoperative three-dimensional spoiled bipolar-readout multi-echo gradient recalled echo and two-dimensional fast spin echo sequences. ASSESSMENT: Movement Disorder Society-sponsored revision of the Unified Parkinson's Disease Rating Scale part III (MDS-UPDRS III) scores were assessed 2-3 days before and 6 months after STN-DBS. The first- and second-order texture features in regions of interest were measured on susceptibility maps. STATISTICAL TESTS: Intraclass correlation coefficient was used to determine the consistency of the region of interest volumes delineated by the two raters. Pearson or Spearman's correlation coefficients were used to assess the relationship between motor improvement after DBS and texture features. A P-value <0.05 was considered statistically significant. RESULTS: MDS-UPDRS III scores were reduced by 59.9% after STN-DBS in 40 PD patients. Motor improvement correlated with second-order texture parameters in the SN including angular second moment (r = -0.449), correlation (rho = 0.326), sum of squares (r = 0.402), sum of entropy (rho = 0.421), and entropy (r = 0.410). Additionally, DBS outcome negatively correlated with mean susceptibility values in the DN (r = -0.400). DATA CONCLUSION: PD patients with a more homogeneous iron distribution throughout the SN or a higher iron concentration in the DN responded worse to STN-DBS. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY: Stage 1.


Asunto(s)
Estimulación Encefálica Profunda , Enfermedad de Parkinson , Masculino , Femenino , Humanos , Enfermedad de Parkinson/diagnóstico por imagen , Enfermedad de Parkinson/terapia , Resultado del Tratamiento , Estudios Prospectivos , Sustancia Gris/diagnóstico por imagen
6.
World J Surg Oncol ; 21(1): 171, 2023 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-37280630

RESUMEN

BACKGROUND: Colorectal cancer (CRC) is the second leading cause of cancer-related deaths globally. It is essential to identify new CRC-associated therapeutic targets and diagnostic biomarkers. Previous studies have demonstrated that a series of circular RNAs (circRNAs) play a crucial role in CRC pathogenesis. This study assessed the potential of hsa_circ_0064559 in tumor cell growth and progression of CRC. METHODS: Six pairs of matched CRC and normal colorectal tissue samples were sequenced using the Affymetrix Clariom D array. Using RNA interference, the expression of thirteen circRNAs was knocked down in CRC cells. The proliferation of CRC cell lines (RKO and SW620 cells) was detected using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay. Apoptosis and cell cycle were determined by flow-cytometric analysis. An in vivo study uses nude mice to establish a CRC mouse model. The differentially expressed genes were analyzed using Affymetrix primeview human GeneChip array and verified by polymerase chain reaction. RESULTS: Affymetrix Clariom D array analysis revealed that thirteen circRNAs were upregulated in CRC. The proliferation of CRC cell lines was decreased, while the proportion of apoptotic and G1 phase cells was higher after hsa_circ_0064559 knockdown. In vivo xenograft nude mice model revealed that the volume and weight of the tumor were reduced by hsa_circ_0064559 knockdown. In Affymetrix primeview human GeneChip array, we found six upregulated genes (STAT1, ATF2, TNFRSF10B, TGFBR2, BAX, and SQSTM1) and two downregulated genes (SLC4A7 and CD274) related to apoptosis and proliferation of colorectal cancer cells after hsa_circ_0064559 knockdown. CONCLUSIONS: The hsa_circ_0064559 knockdown could inhibit the proliferation, promote apoptosis in CRC cell lines in vitro, and inhibit the development of CRC tumors in vivo. The mechanism may be related to activating a wide range of signaling pathways. The hsa_circ_0064559 may be a potential biomarker for early diagnosis or prognosis of CRC and a novel drug target for CRC therapy.


Asunto(s)
Neoplasias Colorrectales , MicroARNs , Animales , Ratones , Humanos , ARN Circular/genética , ARN Circular/metabolismo , Ratones Desnudos , Línea Celular Tumoral , Proliferación Celular/genética , Neoplasias Colorrectales/patología , Ciclo Celular , MicroARNs/genética , Regulación Neoplásica de la Expresión Génica
7.
Soft Matter ; 18(4): 726-734, 2022 Jan 26.
Artículo en Inglés | MEDLINE | ID: mdl-34874397

RESUMEN

Packing structures of granular cylinders with the aspect ratio close to one have been reconstructed with the help of magnetic resonance imaging techniques. By controlling the container boundary conditions and preparation protocols, a structural transformation from a disordered liquid-like state to an orientationally ordered state with cubatic symmetry at a high packing fraction is observed. This ordering process is accompanied by the formation of more faceted contacts, which lower the elastic energy between jammed granular particles to drive the transformation. With the help of Edwards' volume ensemble theory, this granular structural transformation is explained using a phenomenological thermodynamic model and a self-consistent mean-field statistical mechanical model. Both models predict a sharp but continuous change of order parameter when the effective granular temperature is lowered. The intrinsic difference and connection between this granular structural transformation and the entropy-driven phase transition of conventional thermal hard-particle systems are discussed.

8.
Bioorg Med Chem Lett ; 76: 129006, 2022 11 15.
Artículo en Inglés | MEDLINE | ID: mdl-36202190

RESUMEN

A series of novel 1-(1-benzoylpiperidin-4-yl) methanamine derivatives were synthesized and evaluated for the serotonin reuptake inhibitory abilities and binding affinities to the 5-HT1A receptor. The metabolic stabilities of these compounds were measured in vitro using human or mouse liver microsomes and the antidepressant activities were explored In vivo using the forced swimming test (FST) and tail suspension test (TST) in mice. The results indicated that the compound 12a exhibited strongest serotonin reuptake inhibition (IC50 = 8.2 nM) and marked 5-HT1A receptor affinity (Ki = 0.069 nM), which were significantly superior to lead compounds Ⅰ and Ⅱ. Meanwhile, compound 12a showed good metabolic stability in vitro and exhibited potential antidepressant-like effects in the FST and TST in mice.


Asunto(s)
Inhibidores Selectivos de la Recaptación de Serotonina , Serotonina , Humanos , Ratones , Animales , Inhibidores Selectivos de la Recaptación de Serotonina/farmacología , Receptor de Serotonina 5-HT1A , Antidepresivos/farmacología , Antidepresivos/uso terapéutico , Natación
9.
Inorg Chem ; 61(42): 16632-16638, 2022 Oct 24.
Artículo en Inglés | MEDLINE | ID: mdl-36239459

RESUMEN

Single crystals and polycrystalline samples of Ho5Pd4Sn12 have been synthesized using flux and arc-melting methods, respectively. Single-crystal X-ray diffraction studies indicate that Ho5Pd4Sn12 crystallizes in a tetragonal structure (I4/m) at room temperature and transforms into a monoclinic structure (C2/m) below ∼194 K. This structural transition is further supported by a transmission electron microscopy study and an anomaly at ∼194 K in the specific heat data. Temperature-dependent resistivity data also show a kink around the structural transition temperature. Ho5Pd4Sn12 is antiferromagnetically ordered below 7 K. Ho5Pd4Sn12 shows magnetic anisotropy, and the isothermal magnetization curve (H⊥c) at 2 K exhibits a field-induced magnetic phase transition around 22.8 kOe.

10.
Bioorg Med Chem ; 64: 116765, 2022 06 15.
Artículo en Inglés | MEDLINE | ID: mdl-35477061

RESUMEN

With the aim to discover a novel potent potassium-competitive acid blocker (P-CAB) agent, a series of 5-methyl-2,4,5,6-tetrahydropyrrolo[3,4-c]pyrazole derivatives were synthesized, and their H+/K+-ATPase inhibitory activities and inhibitory action on histamine-stimulated gastric acid secretion in rats were evaluated. Among the compounds synthesized, compound 3'-((3-(2-fluorophenyl)-5-methyl-5,6-dihydropyrrolo[3,4-c]pyrazol-2(4H)-yl)methyl)-[1,1'-biphenyl]-3-carboxamide not only exhibited potent H+/K+-ATPase inhibitory activity but olso showed potent inhibitory action in vivo on histamine-stimulated gastric acid secretion. In addition, the lead compound displayed favourable oral pharmacokinetic properties in rats, which was worthy of further study as a novel P-CAB agent.


Asunto(s)
Ácido Gástrico , ATPasa Intercambiadora de Hidrógeno-Potásio , Animales , Ácido Gástrico/metabolismo , ATPasa Intercambiadora de Hidrógeno-Potásio/metabolismo , Histamina , Potasio/metabolismo , Inhibidores de la Bomba de Protones/farmacología , Pirazoles/farmacología , Pirroles/farmacología , Ratas
11.
Nano Lett ; 21(24): 10238-10243, 2021 Dec 22.
Artículo en Inglés | MEDLINE | ID: mdl-34860026

RESUMEN

Swift electrons can undergo inelastic interactions not only with electrons but also with near-fields, which may result in an energy loss or gain. Developments in photon-induced near-field electron microscopy (PINEM) enable direct imaging of the plasmon near-field distribution with nanometer resolution. Here, we report an analysis of the surface plasmonic near-field structure based on PINEM observations of silver nanowires. Single-photon order-selected electron images revealed the wavelike and banded structure of electric equipotential regions for a confined near-field integral associated with typical absorption of photon quanta (nℏω). Multimodal plasmon oscillations and second-harmonic generation were simultaneously observed, and the polarization dependence of plasmon wavelength and symmetry properties were analyzed. Based on advanced imaging techniques, our work has implications for future studies of the localized-field structures at interfaces and visualization of novel phenomena in nanostructures, nanosensors, and plasmonic devices.

12.
Molecules ; 27(7)2022 Mar 28.
Artículo en Inglés | MEDLINE | ID: mdl-35408572

RESUMEN

Opioid receptors are members of the group of G protein-couple receptors, which have been proven to be effective targets for treating severe pain. The interactions between the opioid receptors and corresponding ligands and the receptor's activation by different agonists have been among the most important fields in opioid research. In this study, with compound M1, an active metabolite of tramadol, as the clue compound, several aminomethyl tetrahydronaphthalenes were designed, synthesized and assayed upon opioid receptors. With the resultant compounds FW-AII-OH-1 (Ki = 141.2 nM for the κ opioid receptor), FW-AII-OH-2 (Ki = 4.64 nM for the δ opioid receptor), FW-DI-OH-2 (Ki = 8.65 nM for the δ opioid receptor) and FW-DIII-OH-2 (Ki = 228.45 nM for the δ opioid receptor) as probe molecules, the structural determinants responsible for the subtype selectivity and activation mechanisms were further investigated by molecular modeling and molecular dynamics simulations. It was shown that Y7.43 was a key residue in determining the selectivity of the three opioid receptors, and W6.58 was essential for the selectivity of the δ opioid receptor. A detailed stepwise discovered agonist-induced signal transduction mechanism of three opioid receptors by aminomethyl tetrahydronaphthalene compounds was proposed: the 3-7 lock between TM3 and TM7, the DRG lock between TM3 and TM6 and rearrangement of I3.40, P5.50 and F6.44, which resulted in the cooperative movement in 7 TMs. Then, the structural relaxation left room for the binding of the G protein at the intracellular site, and finally the opioid receptors were activated.


Asunto(s)
Receptores Opioides delta , Receptores Opioides , Simulación de Dinámica Molecular , Receptores Opioides/metabolismo , Receptores Opioides delta/metabolismo , Receptores Opioides mu/metabolismo , Transducción de Señal , Relación Estructura-Actividad , Tetrahidronaftalenos
13.
Soft Matter ; 17(10): 2963-2972, 2021 Mar 18.
Artículo en Inglés | MEDLINE | ID: mdl-33595009

RESUMEN

The jamming transition and jammed packing structures of hydrogel soft ellipsoids are studied using magnetic resonance imaging techniques. As the packing fraction increases, the fluctuation of local free volume decreases and the fluctuation of particle deformation increases. Effective thermodynamic quantities are obtained by characterizing these fluctuations using k-gamma distributions based on an underlying statistical model for granular materials. Surprisingly, the two granular temperatures measuring the relative fluctuations of both free volume and particle deformation remain basically unchanged as the packing fraction increases. The total configurational entropy is also approximately constant for packing with different packing fractions. The significantly different behaviors of these effective thermodynamic quantities compared with hard sphere systems are further attributed to a statistically affine structural transformation of the packing structures along with particle deformations when the packing fraction changes.

14.
Bioorg Med Chem Lett ; 31: 127681, 2021 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-33189775

RESUMEN

In this study, a series of trans-4-(2-(1,2,4,5-tetrahydro-3H-benzo[d]azepin-3-yl)ethyl)cyclohexan-1-amine derivatives as potential antipsychotics were synthesized and biologically evaluated to discover potential antipsychotics with good drug target selectivity. The preliminary structure-activity relationship was discussed, and optimal compound 12a showed both nanomolar affinity for D2/D3/5-HT1A/5-HT2A receptors and weak α1 and H1 receptor binding affinity. In addition, 12a was metabolically stable in vitro, displayed micromolar affinity for the hERG channel, and exhibited antipsychotic efficacy in the animal model of locomotor-stimulating effects of phencyclidine.


Asunto(s)
Aminas/farmacología , Antipsicóticos/farmacología , Azepinas/farmacología , Ciclohexanos/farmacología , Receptores Dopaminérgicos/metabolismo , Receptores de Serotonina/metabolismo , Aminas/síntesis química , Aminas/química , Animales , Antipsicóticos/síntesis química , Antipsicóticos/química , Azepinas/síntesis química , Azepinas/química , Ciclohexanos/síntesis química , Ciclohexanos/química , Relación Dosis-Respuesta a Droga , Humanos , Locomoción/efectos de los fármacos , Simulación del Acoplamiento Molecular , Estructura Molecular , Relación Estructura-Actividad
15.
Bioorg Chem ; 115: 105239, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-34399321

RESUMEN

A novel class of diaryl substituted azetidin-2-one derivatives were designed, asymmetrically synthesized, and evaluated for antiproliferative activities. The in vitro antitumor assay revealed that among the 4-aryl-substituted 1-(3,4,5-trimethoxyphenyl)azetidin-2-ones (B series), most possessed moderate to strong activities, with compound B7c that bears a 2-naphthyl substituent being the most potent one (IC50 0.16-0.40 µM) against a panel of human cancer cell lines. In contrast, none of the 3-(arylmethylene)-substituted 1-(3,4,5-trimethoxyphenyl)azetidin-2-ones (L series) showed significant activities in the assay. Further studies indicated that B7c inhibited tubulin polymerization, disrupted in vitro vascularization, blocked cell cycle progression at G2/M phase, induced cell apoptosis, decreased mitochondrial membrane potential, and increased the intracellular reactive oxygen species level in a dose-dependent way. Compound B7c also inhibited significantly tumor growth in a xenograft mice model with no obvious drop in the mice body weights. Collectively, these results suggested that B7c and its analogues should merit further investigation as new promising antitumor agents.


Asunto(s)
Antineoplásicos/farmacología , Azetidinas/farmacología , Diseño de Fármacos , Moduladores de Tubulina/farmacología , Tubulina (Proteína)/metabolismo , Antineoplásicos/síntesis química , Antineoplásicos/química , Azetidinas/síntesis química , Azetidinas/química , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Estructura Molecular , Polimerizacion/efectos de los fármacos , Relación Estructura-Actividad , Moduladores de Tubulina/síntesis química , Moduladores de Tubulina/química
16.
Bioorg Chem ; 117: 105407, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34653945

RESUMEN

A series of quinazolinyl-containing benzamide derivatives were designed, synthesized and evaluated for their in vitro histone deacetylase 1 (HDAC1) inhibitory activities. Compounds 11a surpassed the known class I selective HDAC inhibitor MS-275 in both HDAC1 enzymatic inhibitory activity and cellular anti-proliferative activity against a selected set of cancer cell types (Hut78, K562, Hep3B and HCT116 cells) with no observed effects on human normal cells. In particular, compound 11a inhibited HDAC1 over the other tested HDACs isoforms (HDAC2, HDAC6 and HDAC8) with acceptable safety profiles. Moreover, compound 11a displayed favorable oral pharmacokinetic properties and showed significant antitumor activity in the A549 tumor xenograft model in vivo.


Asunto(s)
Antineoplásicos/farmacología , Benzamidas/farmacología , Histona Desacetilasa 1/antagonistas & inhibidores , Inhibidores de Histona Desacetilasas/farmacología , Animales , Antineoplásicos/química , Antineoplásicos/uso terapéutico , Apoptosis/efectos de los fármacos , Benzamidas/química , Benzamidas/uso terapéutico , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Ensayos de Selección de Medicamentos Antitumorales , Histona Desacetilasa 1/metabolismo , Inhibidores de Histona Desacetilasas/química , Inhibidores de Histona Desacetilasas/uso terapéutico , Humanos , Ratones Endogámicos ICR , Simulación del Acoplamiento Molecular
17.
Mov Disord ; 35(10): 1787-1795, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-32681698

RESUMEN

BACKGROUND: Currently, no study has evaluated metal accumulation in the brains of patients with Wilson's disease by using quantitative susceptibility mapping at 3T MRI. The objectives of this study were to qualitatively and quantitatively evaluate changes in magnetic susceptibility and R2* maps in deep gray matter nuclei to discriminate Wilson's disease patients from healthy controls and to evaluate their sensitivities in diagnosing Wilson's disease. METHODS: Magnetic susceptibility and R2* maps and conventional T1-weighted, T2-weighted, and T2-weighted fluid-attenuated inversion recovery images were obtained from 17 Wilson's disease patients and 14 age-matched healthy controls on a 3T MRI scanner. Differences between Wilson's disease and healthy control groups in susceptibility and R2* values in multiple deep nuclei were evaluated using a Mann-Whitney U test and receiver operating characteristic curves. The correlations of susceptibility and R2* values with Unified Wilson's Disease Rating Scale score were also performed. RESULTS: Magnetic susceptibility and R2* can effectively distinguish different types of signal abnormalities. Magnetic susceptibility and R2* values in multiple deep nuclei of Wilson's disease patients were significantly higher than those in healthy controls. Magnetic susceptibility value in the substantia nigra had the highest area under the curve (0.888). There were positive correlations of the Unified Wilson's Disease Rating Scale score with susceptibility values in the caudate nucleus (r = 0.757, P = 0.011), putamen (r = 0.679, P = 0.031), and red nucleus (r = 0.638, P = 0.047), as well as R2* values in the caudate nucleus (r = 0.754, P = 0.012). CONCLUSIONS: Quantitative susceptibility mapping at 3T could be a useful tool to evaluate metal accumulation in deep gray matter nuclei of Wilson's disease patients. © 2020 International Parkinson and Movement Disorder Society.


Asunto(s)
Degeneración Hepatolenticular , Encéfalo/diagnóstico por imagen , Mapeo Encefálico , Degeneración Hepatolenticular/diagnóstico por imagen , Humanos , Imagen por Resonancia Magnética , Sustancia Negra
18.
J Chem Phys ; 152(11): 114202, 2020 Mar 21.
Artículo en Inglés | MEDLINE | ID: mdl-32199423

RESUMEN

Investigating the local micromagnetic structure of ferromagnetic nanowires (NWs) at the nanoscale is essential to study the structure-property relationships and can facilitate the design of nanostructures for technology applications. Herein, we synthesized high-quality iron and cobalt NWs and investigated the magnetic properties of these NWs using off-axis electron holography. The Fe NWs are about 100 nm in width and a few micrometers in length with a preferential growth direction of [100], while the Co NWs have a higher aspect-ratio with preferential crystal growth along the [110] direction. It is noted that compact passivation surface layers of oxides protect these NWs from further oxidation, even after nearly two years of exposure to ambient conditions; furthermore, these NWs display homogeneous ferromagnetism along their axial direction revealing the domination of shape anisotropy on magnetic behavior. Importantly, the average value of magnetic induction strengths of Fe NWs (2.07 {±} 0.10 T) and Co NWs (1.83 {±} 0.15 T) is measured to be very close to the respective theoretical value, and it shows that the surface oxide layers do not affect the magnetic moments in NWs. Our results provide a useful synthesis approach for the fabrication of single-crystalline, defect-free metal NWs and give insight into the micromagnetic properties in ferromagnetic NWs based on the transmission electron microscopy measurements.

19.
MAGMA ; 33(6): 809-818, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-32462557

RESUMEN

PURPOSE: The purpose of this study was to characterize the individual contribution of multiple fat peaks to the measured chemical exchange saturation transfer (CEST) signal when using water-selective binomial-pulse excitation and to determine the effects of multiple fat peaks in the presence of B0 inhomogeneity. METHODS: The excitation profiles of multiple binomial pulses were simulated. A CEST sequence with binomial-pulse excitation and modified point-resolved spectroscopy localization was then applied to the in vivo lumbar spinal vertebrae to determine the signal contributions of three distinct groups of lipid resonances. These confounding signal contributions were measured as a function of the irradiation frequency offset to determine the effect of the multi-peak nature of the fat signal on CEST imaging of exchange sites (at 1.0, 2.0 and 3.5 ppm) and robustness in the presence of B0 inhomogeneity. RESULTS: Numerical simulations and in vivo experiments showed that water excitation (WE) using a 1-3-3-1 (WE-4) pulse provided the broadest signal suppression, which provided partial robustness against B0 inhomogeneity effects. Confounding fat signal contributions to the CEST contrasts at 1.0, 2.0 and 3.5 ppm were unavoidable due to the multi-peak nature of the fat signal. However, these CEST sites only suffer from small lipid artifacts with ∆B0 spanning roughly from - 50 to 50 Hz. Especially for the CEST site at 3.5 ppm, the lipid artifacts are smaller than 1% with ∆B0 in this range. CONCLUSION: In WE-4-based CEST magnetic resonance imaging, B0 inhomogeneity is the limiting factor for fat suppression. The CEST sites at 1.0, 2.0 ppm and 3.5 ppm unavoidably suffer from lipid artifacts. However, when the ∆B0 is confined to a limited range, these CEST sites are only affected by small lipid artifacts, which may be ignorable in some cases of clinical applications.


Asunto(s)
Imagen por Resonancia Magnética , Agua , Artefactos , Fantasmas de Imagen
20.
J Headache Pain ; 21(1): 47, 2020 May 06.
Artículo en Inglés | MEDLINE | ID: mdl-32375638

RESUMEN

BACKGROUND: Migraine is a severe and disabling brain disorder, and the exact neurological mechanisms remain unclear. Migraineurs have altered pain perception, and headache attacks disrupt their sensory information processing and sensorimotor integration. The altered functional connectivity of sub-regions of sensorimotor brain areas with other brain cortex associated with migraine needs further investigation. METHODS: Forty-eight migraineurs without aura during the interictal phase and 48 age- and sex-matched healthy controls underwent resting-state functional magnetic resonance imaging scans. We utilized seed-based functional connectivity analysis to investigate whether patients exhibited abnormal functional connectivity between sub-regions of sensorimotor brain areas and cortex regions. RESULTS: We found that patients with migraineurs without aura exhibited disrupted functional connectivities between the sensorimotor areas and the visual cortex, temporal cortex, posterior parietal lobule, prefrontal areas, precuneus, cingulate gyrus, sensorimotor areas proper and cerebellum areas compared with healthy controls. In addition, the clinical data of the patients, such as disease duration, pain intensity and HIT-6 score, were negatively correlated with these impaired functional connectivities. CONCLUSION: In patients with migraineurs without aura, the functional connectivities between the sensorimotor brain areas and other brain regions was reduced. These disrupted functional connectivities might contribute to abnormalities in visual processing, multisensory integration, nociception processing, spatial attention and intention and dysfunction in cognitive evaluation and modulation of pain. Recurrent headache attacks might lead to the disrupted network between primary motor cortex and temporal regions and between primary somatosensory cortex and temporal regions. Pain sensitivity and patient quality of life are closely tied to the abnormal functional connectivity between sensorimotor regions and other brain areas.


Asunto(s)
Imagen por Resonancia Magnética/métodos , Migraña sin Aura/diagnóstico por imagen , Corteza Motora/diagnóstico por imagen , Red Nerviosa/diagnóstico por imagen , Corteza Somatosensorial/diagnóstico por imagen , Lóbulo Temporal/diagnóstico por imagen , Adulto , Mapeo Encefálico/métodos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Migraña sin Aura/fisiopatología , Corteza Motora/fisiopatología , Red Nerviosa/fisiopatología , Dolor/diagnóstico por imagen , Dolor/fisiopatología , Calidad de Vida , Corteza Somatosensorial/fisiopatología , Lóbulo Temporal/fisiopatología , Adulto Joven
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