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1.
Antioxidants (Basel) ; 13(4)2024 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-38671924

RESUMEN

Manganese porphyrins reportedly exhibit synergic effects when combined with irradiation. However, an in-depth understanding of intratumoral heterogeneity and immune pathways, as affected by Mn porphyrins, remains limited. Here, we explored the mechanisms underlying immunomodulation of a clinical candidate, MnTnBuOE-2-PyP5+ (BMX-001, MnBuOE), using single-cell analysis in a murine carcinoma model. Mice bearing 4T1 tumors were divided into four groups: control, MnBuOE, radiotherapy (RT), and combined MnBuOE and radiotherapy (MnBuOE/RT). In epithelial cells, the epithelial-mesenchymal transition, TNF-α signaling via NF-кB, angiogenesis, and hypoxia-related genes were significantly downregulated in the MnBuOE/RT group compared with the RT group. All subtypes of cancer-associated fibroblasts (CAFs) were clearly reduced in MnBuOE and MnBuOE/RT. Inhibitory receptor-ligand interactions, in which epithelial cells and CAFs interacted with CD8+ T cells, were significantly lower in the MnBuOE/RT group than in the RT group. Trajectory analysis showed that dendritic cells maturation-associated markers were increased in MnBuOE/RT. M1 macrophages were significantly increased in the MnBuOE/RT group compared with the RT group, whereas myeloid-derived suppressor cells were decreased. CellChat analysis showed that the number of cell-cell communications was the lowest in the MnBuOE/RT group. Our study is the first to provide evidence for the combined radiotherapy with a novel Mn porphyrin clinical candidate, BMX-001, from the perspective of each cell type within the tumor microenvironment.

2.
IEEE Rev Biomed Eng ; 17: 351-368, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-37022919

RESUMEN

Parallel transmission (pTX) techniques are required to tackle a number of challenges, e.g., the inhomogeneous distribution of the transmit field and elevated specific absorption rate (SAR), in ultra-high field (UHF) MR imaging. Additionally, they offer multiple degrees of freedom to create temporally- and spatially-tailored transverse magnetization. Given the increasing availability of MRI systems at 7 T and above, it is anticipated that interest in pTX applications will grow accordingly. One of the key components in MR systems capable of pTX is the design of the transmit array, as this has a major impact on performance in terms of power requirements, SAR and RF pulse design. While several reviews on pTX pulse design and the clinical applicability of UHF exist, there is currently no systematic review of pTX transmit/transceiver coils and their associated performance. In this article, we analyze transmit array concepts to determine the strengths and weaknesses of different types of design. We systematically review the different types of individual antennas employed for UHF, their combination into pTX arrays, and methods to decouple the individual elements. We also reiterate figures-of-merit (FoMs) frequently employed to describe the performance of pTX arrays and summarize published array designs in terms of these FoMs.


Asunto(s)
Imagen por Resonancia Magnética , Humanos , Imagen por Resonancia Magnética/métodos , Diseño de Equipo
3.
Adv Mater ; 36(1): e2308684, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37947147

RESUMEN

Zn metal anodes (ZMAs) undergo irregular deposition and unfavorable side reactions, which hinders the practical application of aqueous rechargeable Zn metal batteries (ARZMBs). Chemical replacement reaction (CRR) strategies can achieve stable ZMAs, but the effect of the crystal facets of metallic Zn as reductants remains poorly understood. In this study, based on the observation that preferentially exposed Zn crystal facets affect the surface characteristics of chemically replaced layers in Sn-based CRR, a multifunctional Sn-based interfacial layer (ZnTCF@Sn) is designed on the Zn with textured crystal facets using a novel two-step CRR process. ZnTCF@Sn simultaneously provides abundant zincophilic sites and high surface energy and homogenizes the distribution of current/Zn2+ flux, resulting in fast electrochemical kinetics and dendrite-free deposition. Furthermore, the uniform Sn coverage on the ZnTCF@Sn surface inhibits side reactions and enhances reversibility during Zn deposition/dissolution. Thus, the ZnTCF@Sn achieves exceptional cyclability over 1200 h even under harsh operating conditions with a cumulative capacity of 24 Ah cm-2 . This study contributes to the development of practical ARZMBs by providing new insights into the effect of the Zn crystal facets on the surface modification of ZMAs through various CRRs.

4.
Breast Cancer Res Treat ; 203(3): 449-461, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37902934

RESUMEN

PURPOSE: This study aimed to compare the radiosensitizing effect of the PARP inhibitor, Olaparib, between proton and X-rays irradiations in BRCA-proficient breast cancer (BC) cells. METHODS: Two BRCA-proficient BC cell lines, MDA-MB-231 and T47D BC, were used. Cell proliferation was assessed using the CCK-8 assay, and radiosensitivity was determined through the clonogenic survival assay. Flow cytometry was employed to analyze cell cycle distribution and apoptosis. The kinetics of DNA damage repair were evaluated using γH2AX immunofluorescence imaging and the comet assay. Tumor spheroid assays were conducted to test radiosensitivity in a three-dimensional culture condition. RESULTS: Olaparib sensitized both MDA-MB-231 and T47D cells to proton and X-ray irradiation in the clonogenic assay. MDA-MB-231 cells exhibited a higher dose enhancement factor for Olaparib than T47D cells. Olaparib increased radiation-induced G2/M cell cycle arrest and apoptosis specifically in MDA-MB-231 cells. γH2AX immunostaining and the comet assay showed Olaparib augmented radiation-induced DNA damage and apoptosis. The enhancement effect of Olaparib was more pronounced in proton irradiation than in X-ray irradiation, particularly in MDA-MB-231 cells than T47D cells. Both radiation and Olaparib dose-dependently inhibited spheroid growth in both cell lines. The synergy scores demonstrated that Olaparib interacted more strongly with protons than X-rays. The addition of an ATR inhibitor further enhanced Olaparib-induced proton radiosensitization in MDA-MB-231 cells. CONCLUSION: This study found that Olaparib enhanced radiation efficacy in BRCA-proficient breast cancer cells, with a more pronounced effect observed with proton irradiation compared to X-ray irradiation. Combining Olaparib with an ATR inhibitor increased the radiosensitizing effect of protons.


Asunto(s)
Neoplasias de la Mama , Piperazinas , Fármacos Sensibilizantes a Radiaciones , Humanos , Femenino , Rayos X , Protones , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/genética , Neoplasias de la Mama/radioterapia , Línea Celular Tumoral , Fármacos Sensibilizantes a Radiaciones/farmacología , Ftalazinas/farmacología , Apoptosis
5.
Sci Rep ; 13(1): 14311, 2023 Aug 31.
Artículo en Inglés | MEDLINE | ID: mdl-37652972

RESUMEN

We developed a facile method to produce a uniform chromate conversion (CC) coating on zinc alloy-plated steel substrates (ZS). When an acidic CC solution is applied to ZS (C-ZS), zinc is dissolved and chromium ions are reduced to form a chromate coating. In localized areas where zinc is excessively dissolved, zinc hydroxide particles are formed, which hinders the formation of a uniform chromate film, leaving the areas vulnerable to further corrosion (i.e., the formation of dark spots) when exposed to high humidity conditions. To suppress the excessive dissolution of zinc, the ZS surface was pretreated with thiolated polyethylene oxide to form a hydrophilic self-assembled monolayer. A more uniform protective CC coating was obtained on the pretreated ZS, resulting in superior corrosion resistance under high humidity conditions.

6.
IEEE Trans Med Imaging ; 42(5): 1424-1430, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-37015697

RESUMEN

MR measurement using a combination of X-nuclei and proton MRI is of great interest as the information provided by the two nuclei is highly complementary, with the X-nuclei signal giving metabolic data relating to potential biomarkers and the proton signal affording anatomical details. Due to the relatively weak signal obtained from X-nuclei, combining an X-nuclei coil with a proton coil is also advantageous for [Formula: see text] shimming and scout images. One approach to building a double-resonant coil is to modify the coil geometry. Here, to achieve double-resonance, a 2× 1 ladder network was designed and tuned at both proton and X-nuclei frequencies successfully. Due to coupling between closed wires, the double-tuned coil generates a shifted transmit efficiency pattern compared to that of the single-tuned loop at the 7T MRI proton frequency. To compensate for the shifted pattern, one part of the 2× 1 ladder network was folded, and the tuning and performance of the folded double-tuned coil were evaluated in simulations and MR measurements. The proposed structure was further evaluated with overlapped decoupling in a receive-only array. The results show that our proposed folded double-tuned coil moderated the shifted pattern of a straight double-tuned loop coil and provided minimum losses at both proton and X-nuclei frequencies. The proposed folded double-tuned loop coil has also been further extended to a receive-only array.


Asunto(s)
Imagen por Resonancia Magnética , Protones , Fantasmas de Imagen , Diseño de Equipo , Imagen por Resonancia Magnética/métodos , Núcleo Celular
7.
Neoplasia ; 35: 100862, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36508876

RESUMEN

Intrinsic or acquired radioresistance often limits the efficacy of radiation therapy (RT), thereby leading to local control failure. Cancerous cells have abnormal pH dynamics due to high metabolic demands, but it is unclear how pH dynamics contribute to radioresistance. In this study, we investigated the role of Na-H exchange 1 (NHE1), the major intracellular pH (pHi) regulator, in RT response. We observed that RT increased NHE1 expression and modulated pHi in MDA-MB-231 human breast cancer cells. When combined with RT, pharmacological NHE1 inhibition by 5-(N-Ethyl-N-isopropyl)amiloride (EIPA) reduced pHi and clonogenic survival. EIPA attenuated radiation-damaged DNA repair, increasing G2/M cell cycle arrest. The combination of EIPA and RT increased apoptotic cell death while decreasing phosphorylation of NF-κB p65. Similarly, the knockdown of NHE1 increased radiosensitivity with lower pHi and increased apoptosis. Consistent with in vitro data, the EIPA plus RT inhibited the growth of MDA-MB-231 xenograft tumors in mice to a greater extent than either EIPA or RT alone. EIPA abrogated the RT-induced increase in NHE1 and phospho-NF-κB p65 expression in tumor tissues. Such coincidence of increased NHE1 level, pHi, and NF-κB activation was also found in radioresistant MDA-MB-231 cells, which were reversed by EIPA treatment. Bioinformatics analysis of RNA sequencing data revealed that inhibiting NHE1 reversed three core gene networks that were up-regulated in radioresistant cells and correlated with high NHE1 expression in patient samples: NF-κB, senescence, and extracellular matrix. Taken together, our findings suggest that NHE1 contributes to RT resistance via NF-κB-mediated signaling networks, and NHE1 may be a promising target for improving RT outcomes.


Asunto(s)
Neoplasias de la Mama , FN-kappa B , Humanos , Ratones , Animales , Femenino , FN-kappa B/metabolismo , Intercambiadores de Sodio-Hidrógeno/genética , Intercambiadores de Sodio-Hidrógeno/metabolismo , Intercambiador 1 de Sodio-Hidrógeno/genética , Intercambiador 1 de Sodio-Hidrógeno/metabolismo , Amilorida/farmacología , Apoptosis , Neoplasias de la Mama/genética , Neoplasias de la Mama/radioterapia , Concentración de Iones de Hidrógeno
8.
Opt Express ; 30(26): 46956-46971, 2022 Dec 19.
Artículo en Inglés | MEDLINE | ID: mdl-36558634

RESUMEN

We present an innovative ellipsometry technique called self-interferometric pupil ellipsometry (SIPE), which integrates self-interference and pupil microscopy techniques to provide the high metrology sensitivity required for metrology applications of advanced semiconductor devices. Due to its unique configuration, rich angle-resolved ellipsometric information from a single-shot hologram can be extracted, where the full spectral information corresponding to incident angles from 0° to 70° with azimuthal angles from 0° to 360° is obtained, simultaneously. The performance and capability of the SIPE system were fully validated for various samples including thin-film layers, complicated 3D structures, and on-cell overlay samples on the actual semiconductor wafers. The results show that the proposed SIPE system can achieve metrology sensitivity up to 0.123 nm. In addition, it provides small spot metrology capability by minimizing the illumination spot diameter up to 1 µm, while the typical spot diameter of the industry standard ellipsometry is around 30 µm. As a result of collecting a huge amount of angular spectral data, undesirable multiple parameter correlation can be significantly reduced, making SIPE ideally suited for solving several critical metrology challenges we are currently facing.

9.
Int J Mol Sci ; 23(24)2022 Dec 08.
Artículo en Inglés | MEDLINE | ID: mdl-36555180

RESUMEN

Although the combination of radiotherapy and immunotherapy has proven to be effective in lung cancer treatment, it may not be sufficient to fully activate the antitumor immune response. Here, we investigated whether entinostat, a histone deacetylase inhibitor, could improve the efficacy of radiotherapy and anti-PD-1 in a murine syngeneic LL/2 tumor model. A total of 12 Gy of X-rays administered in two fractions significantly delayed tumor growth in mice, which was further enhanced by oral entinostat administration. Flow cytometry-aided immune cell profiling revealed that entinostat increased radiation-induced infiltration of myeloid-derived suppressor cells and CD8+ T cells with decreased regulatory T-cells (Tregs). Transcriptomics-based immune phenotype prediction showed that entinostat potentiated radiation-activated pathways, such as JAK/STAT3/interferon-gamma (IFN-γ) and PD-1/PD-L1 signaling. Entinostat augmented the antitumor efficacy of radiation and anti-PD-1, which may be related to an increase in IFN-γ-producing CD8+ T-cells with a decrease in Treg cells. Comparative transcriptomic profiling predicted that entinostat increased the number of dendritic cells, B cells, and T cells in tumors treated with radiation and anti-PD-1 by inducing MHC-II genes. In conclusion, our findings provided insights into how entinostat improves the efficacy of ionizing radiation plus anti-PD-1 therapy and offered clues for developing new strategies for clinical trials.


Asunto(s)
Carcinoma Pulmonar de Lewis , Inhibidores de Histona Desacetilasas , Animales , Ratones , Inhibidores de Histona Desacetilasas/farmacología , Inhibidores de Histona Desacetilasas/uso terapéutico , Linfocitos T CD8-positivos , Carcinoma Pulmonar de Lewis/tratamiento farmacológico , Inmunomodulación , Inmunidad , Interferón gamma/farmacología , Línea Celular Tumoral , Microambiente Tumoral
10.
Int J Mol Sci ; 23(21)2022 Oct 26.
Artículo en Inglés | MEDLINE | ID: mdl-36361712

RESUMEN

High-throughput mass-spectrometry-based quantitative proteomic analysis was performed using formalin-fixed, paraffin-embedded (FFPE) biopsy samples obtained before treatment from 13 patients with locally advanced rectal cancer (LARC), who were treated with concurrent chemoradiation therapy (CCRT) followed by surgery. Patients were divided into complete responder (CR) and non-complete responder (nCR) groups. Immunohistochemical (IHC) staining of 79 independent FFPE tissue samples was performed to validate the predictive ability of proteomic biomarker candidates. A total of 3637 proteins were identified, and the expression of 498 proteins was confirmed at significantly different levels (differentially expressed proteins-DEPs) between two groups. In Gene Ontology enrichment analyses, DEPs enriched in biological processes in the CR group included proteins linked to cytoskeletal organization, immune response processes, and vesicle-associated protein transport processes, whereas DEPs in the nCR group were associated with biosynthesis, transcription, and translation processes. Dual oxidase 2 (DUOX2) was selected as the most predictive biomarker in machine learning algorithm analysis. Further IHC validation ultimately confirmed DUOX2 as a potential biomarker for predicting the response of nCR to CCRT. In conclusion, this study suggests that the treatment response to RT may be affected by the pre-treatment tumor microenvironment. DUOX2 is a potential biomarker for the early prediction of nCR after CCRT.


Asunto(s)
Proteómica , Neoplasias del Recto , Humanos , Oxidasas Duales , Biomarcadores , Aprendizaje Automático , Proteínas , Neoplasias del Recto/genética , Neoplasias del Recto/terapia , Neoplasias del Recto/patología , Microambiente Tumoral
11.
Science ; 378(6616): 186-192, 2022 10 14.
Artículo en Inglés | MEDLINE | ID: mdl-36227977

RESUMEN

Studies of the proteome would benefit greatly from methods to directly sequence and digitally quantify proteins and detect posttranslational modifications with single-molecule sensitivity. Here, we demonstrate single-molecule protein sequencing using a dynamic approach in which single peptides are probed in real time by a mixture of dye-labeled N-terminal amino acid recognizers and simultaneously cleaved by aminopeptidases. We annotate amino acids and identify the peptide sequence by measuring fluorescence intensity, lifetime, and binding kinetics on an integrated semiconductor chip. Our results demonstrate the kinetic principles that allow recognizers to identify multiple amino acids in an information-rich manner that enables discrimination of single amino acid substitutions and posttranslational modifications. With further development, we anticipate that this approach will offer a sensitive, scalable, and accessible platform for single-molecule proteomic studies and applications.


Asunto(s)
Proteoma , Proteómica , Aminoácidos/química , Aminopeptidasas , Péptidos/química , Proteómica/métodos , Semiconductores , Análisis de Secuencia de Proteína/métodos
12.
Mar Drugs ; 20(5)2022 May 17.
Artículo en Inglés | MEDLINE | ID: mdl-35621979

RESUMEN

Discovering new drug candidates with high efficacy and few side effects is a major challenge in new drug development. The two evolutionarily related peptides oxytocin (OXT) and arginine vasopressin (AVP) are known to be associated with a variety of physiological and psychological processes via the association of OXT with three types of AVP receptors. Over decades, many synthetic analogs of these peptides have been designed and tested for therapeutic applications; however, only a few studies of their natural analogs have been performed. In this study, we investigated the bioactivity and usefulness of two natural OXT/AVP analogs that originate from the marine invertebrate Octopus vulgaris, named octopressin (OTP) and cephalotocin (CPT). By measuring the intracellular Ca2+ or cyclic AMP increase in each OXT/AVP receptor subtype-overexpressing cell, we found that CPT, but not OTP, acts as a selective agonist of human AVP type 1b and 2 receptors. This behavior is reminiscent of desmopressin, the most widely prescribed antidiuretic drug in the world. Similar to the case for desmopressin, a single intravenous tail injection of CPT into Sprague-Dawley rats reduced urine output and increased urinary osmolality. In conclusion, we suggest that CPT has a significant antidiuretic effect and that CPT might be beneficial for treating urological conditions such as nocturia, enuresis, and diabetes insipidus.


Asunto(s)
Fármacos Antidiuréticos , Octopodiformes , Oxitocina , Animales , Fármacos Antidiuréticos/farmacología , Arginina Vasopresina/análogos & derivados , Desamino Arginina Vasopresina/farmacología , Felipresina/farmacología , Octopodiformes/metabolismo , Oxitocina/análogos & derivados , Oxitocina/farmacología , Ratas , Ratas Sprague-Dawley , Receptores de Vasopresinas/agonistas , Receptores de Vasopresinas/metabolismo
13.
Radiat Oncol J ; 40(1): 53-65, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-35368201

RESUMEN

PURPOSE: This study aims to investigate the effect of splenectomy on radiation-mediated growth inhibition and immune modulation in lung cancer xenograft models. MATERIALS AND METHODS: Human non-small cell lung cancer H1299 cells and murine Lewis lung carcinoma LL/2-luc cells were injected into the right hind leg of BALB/c-nude mice and C57BL/6 mice, respectively. Splenectomy or sham operation was performed prior to tumor cell injection or before and after irradiation during tumor growth. Irradiation was delivered with 2-3 fractions of 6 Gy X-ray using a linear accelerator. Flow cytometry analysis was performed for immune cell profiling. RESULTS: Splenectomy prior to tumor injection or at early stage inhibited growth of LL/2-luc tumors but not that of H1299 tumors; however, it did not enhance the antitumor effect of radiation regardless of intervention timing. Flow cytometry analysis showed monocytic myeloid-derived suppressor cells (MDSCs) and activated CD8+ T cells increased after irradiation in the tumors of splenectomized mice, compared to those of sham-operated mice. Administration of anti-PD-1 (programmed death-1) antibodies improved the ability of splenectomy to attenuate the growth of irradiated tumors. CONCLUSION: Splenectomy has paradoxical effects on radiation-induced tumor growth inhibition, depending on tumor types and intervention timing, but it has an immune-modulating effect when combined with radiation.

14.
Int J Mol Sci ; 23(2)2022 Jan 06.
Artículo en Inglés | MEDLINE | ID: mdl-35054773

RESUMEN

Proton beam therapy (PBT) is a critical treatment modality for head and neck squamous cell carcinoma (HNSCC). However, not much is known about drug combinations that may improve the efficacy of PBT. This study aimed to test the feasibility of a three-dimensional (3D) tumor-spheroid-based high-throughput screening platform that could assess cellular sensitivity against PBT. Spheroids of two HNSCC cell lines-Fadu and Cal27-cultured with a mixture of Matrigel were arrayed on a 384-pillar/well plate, followed by exposure to graded doses of protons or targeted drugs including olaparib at various concentrations. Calcein staining of HNSCC spheroids revealed a dose-dependent decrease in cell viability for proton irradiation or multiple targeted drugs, and provided quantitative data that discriminated the sensitivity between the two HNSCC cell lines. The combined effect of protons and olaparib was assessed by calculating the combination index from the survival rates of 4 × 4 matrices, showing that Cal27 spheroids had greater synergy with olaparib than Fadu spheroids. In contrast, adavosertib did not synergize with protons in both spheroids. Taken together, we demonstrated that the 3D pillar/well array platform was a useful tool that provided rapid, quantitative data for evaluating sensitivity to PBT and drug combinations. Our results further supported that administration of the combination of PBT and olaparib may be an effective treatment strategy for HNSCC patients.


Asunto(s)
Quimioradioterapia , Ensayos de Selección de Medicamentos Antitumorales/métodos , Ensayos Analíticos de Alto Rendimiento/métodos , Terapia de Protones , Esferoides Celulares , Carcinoma de Células Escamosas de Cabeza y Cuello/terapia , Antineoplásicos/uso terapéutico , Línea Celular Tumoral , Humanos
15.
Cancer Res Treat ; 54(1): 40-53, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34044476

RESUMEN

PURPOSE: We investigated the feasibility of using an anatomically localized, target-enriched liquid biopsy (TLB) in mouse models of lung cancer. MATERIALS AND METHODS: After irradiating xenograft mouse with human lung cancer cell lines, H1299 (NRAS proto-oncogene, GTPase [NRAS] Q61K) and HCC827 (epidermal growth factor receptor [EGFR] E746-750del), circulating (cell-free) tumor DNA (ctDNA) levels were monitored with quantitative polymerase chain reaction on human long interspersed nuclear element-1 and cell line-specific mutations. We checked dose-dependency at 6, 12, or 18 Gy to each tumor-bearing mouse leg using 6-MV photon beams. We also analyzed ctDNA of lung cancer patients by LiquidSCAN, a targeted deep sequencing to validated the clinical performances of TLB method. RESULTS: Irradiation could enhance the detection sensitivity of NRAS Q61K in the plasma sample of H1299-xenograft mouse to 4.5- fold. While cell-free DNA (cfDNA) level was not changed at 6 Gy, ctDNA level was increased upon irradiation. Using double-xenograft mouse with H1299 and HCC827, ctDNA polymerase chain reaction analysis with local irradiation in each region could specify mutation type matched to transplanted cell types, proposing an anatomically localized, TLB. Furthermore, when we performed targeted deep sequencing of cfDNA to monitor ctDNA level in 11 patients with lung cancer who underwent radiotherapy, the average ctDNA level was increased within a week after the start of radiotherapy. CONCLUSION: TLB using irradiation could temporarily amplify ctDNA release in xenograft mouse and lung cancer patients, which enables us to develop theragnostic method for cancer patients with accurate ctDNA detection.


Asunto(s)
ADN Tumoral Circulante/sangre , Biopsia Líquida/métodos , Neoplasias Pulmonares/genética , Reparación del Gen Blanco/métodos , Animales , Biomarcadores de Tumor/genética , Estudios de Factibilidad , Humanos , Masculino , Ratones , Ratones Endogámicos BALB C , Mutación , Microambiente Tumoral
16.
IEEE Trans Med Imaging ; 41(5): 1104-1113, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-34860648

RESUMEN

Simultaneous MR-PET/-SPECT is an emerging technology that capitalises on the invaluable advantages of both modalities, allowing access to numerous sensitive tracers and superior soft-tissue contrast alongside versatile functional imaging capabilities. However, to optimise these capabilities, concurrent acquisitions require the MRI antenna located inside the PET/SPECT field-of-view to be operated without compromising any aspects of system performance or image quality compared to the stand-alone instrumentation. Here, we report a novel gamma-radiation-transparent antenna concept. The end-fed J-shape antenna is particularly adept for hybrid ultra-high field MR-PET/-SPECT applications as it enables all highly attenuating materials to be placed outside the imaging field-of-view. Furthermore, this unique configuration also provides advantages in stand-alone MR applications by reducing the amount of coupling between the cables and the antenna elements, and by lowering the potential specific absorption rate burden. The use of this new design was experimentally verified according to the important features for both ultra-high field MRI and the 511 keV transmission scan. The reconstructed attenuation maps evidently showed much lower attenuation (  âˆ¼ 15 %) for the proposed array when compared to the conventional dipole antenna array since there were no high-density components. In MR, it was observed that the signal-to-noise ratio from the whole volume obtained using the proposed array was comparable to that acquired by the conventional array which was also in agreement with the simulation results. The unique feature, J-shape array, would enable simultaneous MR-PET/-SPECT experiments to be conducted without unduly compromising any aspects of system performance and image quality compared to the stand-alone instrumentation.


Asunto(s)
Imagen por Resonancia Magnética , Tomografía de Emisión de Positrones , Procesamiento de Imagen Asistido por Computador/métodos , Imagen por Resonancia Magnética/métodos , Fantasmas de Imagen , Tomografía de Emisión de Positrones/métodos , Relación Señal-Ruido , Tomografía Computarizada de Emisión de Fotón Único
17.
IEEE Rev Biomed Eng ; PP2022 Dec 07.
Artículo en Inglés | MEDLINE | ID: mdl-37015609

RESUMEN

Simultaneously operating MR-PET systems have the potential to provide synergetic multi-parametric information, and, as such, interest surrounding their use and development is increasing. However, despite the potential advantages offered by fully combined MR-PET systems, implementing this hybrid integration is technically laborious, and any factors degrading the quality of either modality must be circumvented to ensure optimal performance. In order to attain the best possible quality from both systems, most full MR-PET integrations tend to place the shielded PET system inside the MRI system, close to the target volume of the subject. The radiofrequency (RF) coil used in MRI systems is a key factor in determining the quality of the MR images, and, in simultaneous acquisition, it is generally positioned inside the PET system and PET imaging region, potentially resulting in attenuation and artefacts in the PET images. Therefore, when designing hybrid MR-PET systems, it is imperative that consideration be given to the RF coils inside the PET system. In this review, we present current state-of-the-art RF coil designs used for hybrid MR-PET experiments and discuss various design strategies for constructing PET transparent RF coils.

18.
Antioxidants (Basel) ; 10(11)2021 Nov 05.
Artículo en Inglés | MEDLINE | ID: mdl-34829640

RESUMEN

Tumor migration and invasion induced by the epithelial-to-mesenchymal transition (EMT) are prerequisites for metastasis. Here, we investigated the inhibitory effect of a mimic of superoxide dismutase (SOD), cationic Mn(III) ortho-substituted N-n-hexylpyridylporphyrin (MnTnHex-2-PyP5+, MnHex) on the metastasis of breast cancer in cellular and animal models, focusing on the migration of tumor cells and the factors that modulate this behavior. Wound healing and Transwell migration assays revealed that the migration of mouse mammary carcinoma 4T1 cells was markedly reduced during the concurrent treatment of MnHex and radiation therapy (RT) compared with that of the control and RT alone. Bioluminescence imaging showed that MnHex/RT co-treatment dramatically reduced lung metastasis of 4T1 cells in mice, compared with the sham control and both single treatments. Western blotting and immunofluorescence showed that MnHex treatment of 4T1 cells reversed the RT-induced EMT via inhibiting AKT/GSK-3ß/Snail pathway in vitro, thereby decreasing cell migration and invasion. Consistently, histopathological analyses of 4T1 tumors showed that MnHex/RT reduced Snail expression, blocked EMT, and in turn suppressed metastases. Again, in the human metastatic breast cancer MDA-MB-231 cell line, MnHex inhibited metastatic potential in vitro and in vivo and suppressed the RT-induced Snail expression. In addition to our previous studies showing tumor growth inhibition, this study demonstrated that MnHex carries the ability to minimize the metastatic potential of RT-treated cancers, thus overcoming their radioresistance.

19.
Pharmaceutics ; 13(11)2021 Oct 29.
Artículo en Inglés | MEDLINE | ID: mdl-34834226

RESUMEN

Immunomodulation by radiotherapy (RT) is an emerging strategy for improving cancer immunotherapy. Nanomaterials have been employed as innovative tools for cancer therapy. This study aimed to investigate whether mesoporous silica nanoparticles (MSNs) enhance RT-mediated local tumor control and the abscopal effect by stimulating anti-cancer immunity. Hepa1-6 murine hepatocellular carcinoma syngeneic models and immunophenotyping with flow cytometry were used to evaluate the immune responses. When mice harboring bilateral tumors received 8 Gy of X-rays on a single tumor, the direct injection of MSNs into irradiated tumors enhanced the growth inhibition of irradiated and unirradiated contralateral tumors. MSNs enhanced RT-induced tumor infiltration of cytotoxic T cells on both sides and suppressed RT-enhanced infiltration of regulatory T cells. The administration of MSNs pre-incubated with irradiated cell-conditioned medium enhanced the anti-tumor effect of anti-PD1 compared to the as-synthesized MSNs. Intracellular uptake of MSNs activated JAWS II dendritic cells (DCs), which were consistently observed in DCs in tumor-draining lymph nodes (TDLNs). Our findings suggest that MSNs may capture tumor antigens released after RT, which is followed by DC maturation in TDLNs and infiltration of cytotoxic T cells in tumors, thereby leading to systemic tumor regression. Our results suggest that MSNs can be applied as an adjuvant for in situ cancer vaccines with RT.

20.
Mar Drugs ; 19(11)2021 Nov 09.
Artículo en Inglés | MEDLINE | ID: mdl-34822498

RESUMEN

The chemical investigation of the marine sponge Dysidea sp., which was collected from Bohol province in the Philippines, resulted in the identification of 15 new scalarane-type sesterterpenoids (1-14, 16), together with 15 known compounds. The chemical structures of the new compounds were elucidated based on NMR spectroscopy and HRMS. The structure of 12-epi-phyllactone D/E (15) isolated during this study was originally identified in 2007. However, careful inspection of our experimental 13C NMR spectrum revealed considerable discrepancies with the reported data at C-9, C-12, C-14, and C-23, leading to the correction of the reported compound to the C-12 epimer of 15, phyllactone D/E. The biological properties of compounds 1-16 were evaluated using the MDA-MB-231 cancer cell line. Compound 7, which bears a pentenone E-ring, exhibits significant cytotoxicity with a GI50 value of 4.21 µM.


Asunto(s)
Dysidea , Sesterterpenos/farmacología , Animales , Organismos Acuáticos , Línea Celular Tumoral/efectos de los fármacos , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Filipinas , Sesterterpenos/química , Estereoisomerismo , Relación Estructura-Actividad
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