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1.
Acta Biomater ; 174: 245-257, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38096959

RESUMO

Recovery of the collagen structure following Achilles tendon rupture is poor, resulting in a high risk for re-ruptures. The loading environment during healing affects the mechanical properties of the tendon, but the relation between loading regime and healing outcome remains unclear. This is partially due to our limited understanding regarding the effects of loading on the micro- and nanostructure of the healing tissue. We addressed this through a combination of synchrotron phase-contrast X-ray microtomography and small-angle X-ray scattering tensor tomography (SASTT) to visualize the 3D organization of microscale fibers and nanoscale fibrils, respectively. The effect of in vivo loading on these structures was characterized in early healing of rat Achilles tendons by comparing full activity with immobilization. Unloading resulted in structural changes that can explain the reported impaired mechanical performance. In particular, unloading led to slower tissue regeneration and maturation, with less and more disorganized collagen, as well as an increased presence of adipose tissue. This study provides the first application of SASTT on soft musculoskeletal tissues and clearly demonstrates its potential to investigate a variety of other collagenous tissues. STATEMENT OF SIGNIFICANCE: Currently our understanding of the mechanobiological effects on the recovery of the structural hierarchical organization of injured Achilles tendons is limited. We provide insight into how loading affects the healing process by using a cutting-edge approach to for the first time characterize the 3D micro- and nanostructure of the regenerating collagen. We uncovered that, during early healing, unloading results in a delayed and more disorganized regeneration of both fibers (microscale) and fibrils (nanoscale), as well as increased presence of adipose tissue. The results set the ground for the development of further specialized protocols for tendon recovery.


Assuntos
Tendão do Calcâneo , Traumatismos dos Tendões , Ratos , Animais , Tendão do Calcâneo/diagnóstico por imagem , Colágeno/farmacologia , Cicatrização , Tomografia por Raios X
2.
Subcell Biochem ; 106: 169-196, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38159227

RESUMO

Viruses are obligate intracellular pathogens that depend on their host cell machinery and metabolism for their replicative life cycle. Virus entry, replication, and assembly are dynamic processes that lead to the reorganisation of host cell components. Therefore, a complete understanding of the viral processes requires their study in the cellular context where advanced imaging has been proven valuable in providing the necessary information. Among the available imaging techniques, soft X-ray tomography (SXT) at cryogenic temperatures can provide three-dimensional mapping to 25 nm resolution and is ideally suited to visualise the internal organisation of virus-infected cells. In this chapter, the principles and practices of synchrotron-based cryo-soft X-ray tomography (cryo-SXT) in virus research are presented. The potential of the cryo-SXT in correlative microscopy platforms is also demonstrated through working examples of reovirus and hepatitis research at Beamline B24 (Diamond Light Source Synchrotron, UK) and BL09-Mistral beamline (ALBA Synchrotron, Spain), respectively.


Assuntos
Tomografia por Raios X , Vírus , Tomografia por Raios X/métodos , Biologia
3.
ACS Nano ; 17(22): 22708-22721, 2023 11 28.
Artigo em Inglês | MEDLINE | ID: mdl-37939169

RESUMO

Plus-strand RNA viruses are proficient at remodeling host cell membranes for optimal viral genome replication and the production of infectious progeny. These ultrastructural alterations result in the formation of viral membranous organelles and may be observed by different imaging techniques, providing nanometric resolution. Guided by confocal and electron microscopy, this study describes the generation of wide-field volumes using cryogenic soft-X-ray tomography (cryo-SXT) on SARS-CoV-2-infected human lung adenocarcinoma cells. Confocal microscopy showed accumulation of double-stranded RNA (dsRNA) and nucleocapsid (N) protein in compact perinuclear structures, preferentially found around centrosomes at late stages of the infection. Transmission electron microscopy (TEM) showed accumulation of membranous structures in the vicinity of the infected cell nucleus, forming a viral replication organelle containing characteristic double-membrane vesicles and virus-like particles within larger vesicular structures. Cryo-SXT revealed viral replication organelles very similar to those observed by TEM but indicated that the vesicular organelle observed in TEM sections is indeed a vesiculo-tubular network that is enlarged and elongated at late stages of the infection. Overall, our data provide additional insight into the molecular architecture of the SARS-CoV-2 replication organelle.


Assuntos
COVID-19 , RNA Viral , Humanos , RNA Viral/metabolismo , COVID-19/diagnóstico por imagem , SARS-CoV-2 , Replicação Viral , Núcleo Celular/metabolismo , Tomografia por Raios X/métodos
4.
J Microsc ; 291(3): 248-255, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37433616

RESUMO

Soft X-ray tomography (SXT) is an imaging technique to visualise whole cells without fixation, staining, and sectioning. For SXT imaging, cells are cryopreserved and imaged at cryogenic conditions. Such 'near-to-native' state imaging is in high demand and initiated the development of the laboratory table-top SXT microscope. As many laboratories do not have access to cryogenic equipment, we asked ourselves whether SXT imaging is feasible on dry specimens. This paper shows how the dehydration of cells can be used as an alternative sample preparation to obtain ultrastructure information. We compare different dehydration processes on mouse embryonic fibroblasts in terms of ultrastructural preservation and shrinkage. Based on this analysis, we chose critical point (CPD) dried cells for SXT imaging. In comparison to cryopreserved and air-dried cells, CPD dehydrated cells show high structural integrity although with about 3-7 times higher X-ray absorption for cellular organelles. As the difference in X-ray absorption values between organelles is preserved, 3D anatomy of CPD-dried cells can be segmented and analysed, demonstrating the applicability of CPD-dried sample preparation for SXT imaging. LAY DESCRIPTION: Soft X-ray tomography (SXT) is an imaging technique that allows to see the internal structures of cells without the need for special treatments like fixation or staining. Typically, SXT imaging involves freezing and imaging cells at very low temperatures. However, since many labs lack the necessary equipment, we explored whether SXT imaging could be done on dry samples instead. We compared different dehydration methods and found that critical point drying (CPD) was the most promising for SXT imaging. CPD-dried cells showed high structural integrity, although they absorbed more X-rays than hydrated cells, demonstrating that CPD-dried sample preparation is a viable alternative for SXT imaging.


Assuntos
Desidratação , Imageamento Tridimensional , Animais , Camundongos , Imageamento Tridimensional/métodos , Fibroblastos , Tomografia por Raios X/métodos , Microscopia
5.
J Clin Endocrinol Metab ; 108(12): 3100-3110, 2023 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-37401630

RESUMO

CONTEXT: Ectopic fat deposition in skeletal muscle, termed myosteatosis, is a key factor in developing insulin resistance. OBJECTIVE: This work aimed to evaluate the association between insulin resistance and myosteatosis in a large Asian population. METHODS: A total of 18 251 participants who had abdominal computed tomography were included in this cross-sectional study. Patients were categorized into 4 groups according to quartiles of Homeostatic Model Assessment for Insulin Resistance (HOMA-IR). The total abdominal muscle area (TAMA) at the L3 vertebral level was segmented into normal-attenuation muscle area (NAMA), low-attenuation muscle area (LAMA), and intermuscular adipose tissue (IMAT). The absolute values of TAMA, NAMA, LAMA, and IMAT and the ratios of NAMA/BMI, LAMA/BMI, and NAMA/TAMA were used as myosteatosis indices. RESULTS: The absolute values of TAMA, NAMA, LAMA, and IMAT appeared to increase with higher HOMA-IR levels, and LAMA/BMI showed a similar upward trend. Meanwhile, the NAMA/BMI and NAMA/TAMA index showed downward trends. As HOMA-IR levels increased, the odds ratios (ORs) of the highest quartile of NAMA/BMI and NAMA/TAMA index decreased and that of LAMA/BMI increased. Compared with the lowest HOMA-IR group, the adjusted ORs (95% CI) in the highest HOMA-IR group for the lowest NAMA/TAMA quartile were 0.414 (0.364-0.471) in men and 0.464 (0.384-0.562) in women. HOMA-IR showed a negative correlation with NAMA/BMI (r = -0.233 for men and r = -0.265 for women), and NAMA/TAMA index (r = -0.211 for men and r = -0.214 for women), and a positive correlation with LAMA/BMI (r = 0.160 for men and r = 0.119 for women); P was less than .001 for all. CONCLUSION: In this study, a higher HOMA-IR level was significantly associated with a high risk of myosteatosis.


Assuntos
Abdome , Resistência à Insulina , Músculo Esquelético , Feminino , Humanos , Masculino , Abdome/diagnóstico por imagem , Estudos Transversais , Resistência à Insulina/fisiologia , Músculo Esquelético/diagnóstico por imagem , Tomografia por Raios X
6.
Proc Natl Acad Sci U S A ; 120(24): e2209938120, 2023 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-37276395

RESUMO

Cryo-soft X-ray tomography (cryo-SXT) is a powerful method to investigate the ultrastructure of cells, offering resolution in the tens of nanometer range and strong contrast for membranous structures without requiring labeling or chemical fixation. The short acquisition time and the relatively large field of view leads to fast acquisition of large amounts of tomographic image data. Segmentation of these data into accessible features is a necessary step in gaining biologically relevant information from cryo-soft X-ray tomograms. However, manual image segmentation still requires several orders of magnitude more time than data acquisition. To address this challenge, we have here developed an end-to-end automated 3D segmentation pipeline based on semisupervised deep learning. Our approach is suitable for high-throughput analysis of large amounts of tomographic data, while being robust when faced with limited manual annotations and variations in the tomographic conditions. We validate our approach by extracting three-dimensional information on cellular ultrastructure and by quantifying nanoscopic morphological parameters of filopodia in mammalian cells.


Assuntos
Aprendizado Profundo , Animais , Raios X , Tomografia por Raios X/métodos , Microscopia de Fluorescência/métodos , Processamento de Imagem Assistida por Computador/métodos , Microscopia Crioeletrônica , Mamíferos
7.
J Infect Chemother ; 29(10): 937-941, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37301372

RESUMO

INTRODUCTION: Renal abscesses are rare in pediatric populations. We aimed to highlight the differences in the computed tomography (CT) imaging characteristics of renal abscesses in patients with and without vesicoureteral reflux (VUR). MATERIALS AND METHODS: Thirteen children with renal abscesses were included and categorized into those with and without VUR. Blood and urine culture results were recorded as positive or negative. Imaging characteristics were recorded: with/without subcapsular fluid collection, with/without upper/lower pole involvement, and with single/multiple lesions in kidneys. Fisher's exact test was used for intergroup comparisons of the rate of positive pathogens and imaging characteristics. RESULTS: Nine patients had VUR (45.9%). Blood and urine culture were positive in two (15.4%) and seven cases (53.8%), respectively. There was no significant difference in the rate of pathogen-positive blood and urine cultures (blood culture positive/negative status with VUR vs. that without VUR = 2/7 vs. 0/4, p > 0.999, urine culture positive/negative status with VUR vs. that without VUR = 4/5 vs. 3/1, p = 0.559). The two groups differed significantly regarding subcapsular fluid collection presence (with/without subcapsular fluid collection with VUR vs. that without VUR = 9/0 vs 1/3, p = 0.014). There was no significant difference in upper/lower pole involvement (with/without involving upper/lower pole with VUR vs. that without VUR = 8/1 vs 2/2, p = 0.203). Patients with VUR were non-significantly more likely to have multiple lesions compared to those without VUR. CONCLUSIONS: VUR was associated with subcapsular fluid collection and possibly with multiple lesions, indicating the need for prompt detection of and specific treatment for VUR in cases with these findings.


Assuntos
Abscesso , Nefropatias , Refluxo Vesicoureteral , Abscesso/diagnóstico , Abscesso/etiologia , Nefropatias/diagnóstico , Nefropatias/etiologia , Refluxo Vesicoureteral/complicações , Humanos , Masculino , Feminino , Lactente , Pré-Escolar , Criança , Tomografia por Raios X
8.
Sci Rep ; 13(1): 9049, 2023 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-37270642

RESUMO

Breast cancer is the most common type of cancer worldwide. Diagnosing breast cancer relies on clinical examination, imaging and biopsy. A core-needle biopsy enables a morphological and biochemical characterization of the cancer and is considered the gold standard for breast cancer diagnosis. A histopathological examination uses high-resolution microscopes with outstanding contrast in the 2D plane, but the spatial resolution in the third, Z-direction, is reduced. In the present paper, we propose two high-resolution table-top systems for phase-contrast X-ray tomography of soft-tissue samples. The first system implements a classical Talbot-Lau interferometer and allows to perform ex-vivo imaging of human breast samples with a voxel size of 5.57 µm. The second system with a comparable voxel size relies on a Sigray MAAST X-ray source with structured anode. For the first time, we demonstrate the applicability of the latter to perform X-ray imaging of human breast specimens with ductal carcinoma in-situ. We assessed image quality of both setups and compared it to histology. We showed that both setups made it possible to target internal features of breast specimens with better resolution and contrast than previously achieved, demonstrating that grating-based phase-contrast X-ray CT could be a complementary tool for clinical histopathology.


Assuntos
Neoplasias da Mama , Humanos , Feminino , Raios X , Radiografia , Neoplasias da Mama/diagnóstico por imagem , Interferometria/métodos , Tomografia por Raios X
9.
J Synchrotron Radiat ; 30(Pt 4): 815-821, 2023 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-37145138

RESUMO

An in-house designed transmission X-ray microscopy (TXM) instrument has been developed and commissioned at beamline BL18B of the Shanghai Synchrotron Radiation Facility (SSRF). BL18B is a hard (5-14 keV) X-ray bending-magnet beamline recently built with sub-20 nm spatial resolution in TXM. There are two kinds of resolution mode: one based on using a high-resolution-based scintillator-lens-coupled camera, and the other on using a medium-resolution-based X-ray sCMOS camera. Here, a demonstration of full-field hard X-ray nano-tomography for high-Z material samples (e.g. Au particles, battery particles) and low-Z material samples (e.g. SiO2 powders) is presented for both resolution modes. Sub-50 nm to 100 nm resolution in three dimensions (3D) has been achieved. These results represent the ability of 3D non-destructive characterization with nano-scale spatial resolution for scientific applications in many research fields.


Assuntos
Dióxido de Silício , Síncrotrons , Raios X , China , Tomografia por Raios X
10.
IEEE Trans Biomed Circuits Syst ; 17(2): 375-389, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-37030851

RESUMO

Model-Based Iterative Reconstruction (MBIR) algorithms iteratively use expensive computational operators of forward and backward projections. The irregular memory access pattern of these operators makes them a memory-bound application. Their computation time must be reduced to meet clinical routine constraints. This article proposes a hardware accelerator architecture based on Field Programmable Gate Arrays (FPGAs) through high-level language, as an alternative to GPU architecture. This acceleration is based on an offline memory access analysis to address the main bottleneck of the algorithm and maximize the data reuse rate. The offline analysis allows for the tuning of the architecture parameters so that they converge to an optimal solution. Then, the Berkeley Roofline model guides our optimization steps by iteratively analyzing the design performance. Our design flow significantly improved the algorithm's computational intensity and overcame the memory bottleneck. Thus, our architecture takes advantage of the FPGA local memory to achieve significant memory bandwidth and efficiently harness the pipeline without stalling the computation. Furthermore, we present the scaling-up strategy from mid-range FPGA to high-end FPGA and any concerns of portability. We used two Intel FPGA devices to implement the algorithm, and then we compared the results with our GPU implementation in terms of speedup and energy efficiency. Our experimental results show that our design has achieved better computational throughput than the works on FPGA architectures reported in the literature.


Assuntos
Algoritmos , Computadores , Tomografia por Raios X
11.
Fluids Barriers CNS ; 20(1): 21, 2023 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-36944985

RESUMO

BACKGROUND: The meninges, formed by dura, arachnoid and pia mater, cover the central nervous system and provide important barrier functions. Located between arachnoid and pia mater, the cerebrospinal fluid (CSF)-filled subarachnoid space (SAS) features a variety of trabeculae, septae and pillars. Like the arachnoid and the pia mater, these structures are covered with leptomeningeal or meningothelial cells (MECs) that form a barrier between CSF and the parenchyma of the optic nerve (ON). MECs contribute to the CSF proteome through extensive protein secretion. In vitro, they were shown to phagocytose potentially toxic proteins, such as α-synuclein and amyloid beta, as well as apoptotic cell bodies. They therefore may contribute to CSF homeostasis in the SAS as a functional exchange surface. Determining the total area of the SAS covered by these cells that are in direct contact with CSF is thus important for estimating their potential contribution to CSF homeostasis. METHODS: Using synchrotron radiation-based micro-computed tomography (SRµCT), two 0.75 mm-thick sections of a human optic nerve were acquired at a resolution of 0.325 µm/pixel, producing images of multiple terabytes capturing the geometrical details of the CSF space. Special-purpose supercomputing techniques were employed to obtain a pixel-accurate morphometric description of the trabeculae and estimate internal volume and surface area of the ON SAS. RESULTS: In the bulbar segment, the ON SAS microstructure is shown to amplify the MECs surface area up to 4.85-fold compared to an "empty" ON SAS, while just occupying 35% of the volume. In the intraorbital segment, the microstructure occupies 35% of the volume and amplifies the ON SAS area 3.24-fold. CONCLUSIONS: We provided for the first time an estimation of the interface area between CSF and MECs. This area is of importance for estimating a potential contribution of MECs on CSF homeostasis.


Assuntos
Nervo Óptico , Humanos , Nervo Óptico/metabolismo , Tomografia por Raios X , Peptídeos beta-Amiloides/metabolismo
12.
Abdom Radiol (NY) ; 48(4): 1280-1289, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36757454

RESUMO

PURPOSE: This study aimed to compare the hepatocellular carcinoma (HCC) detection performance, interobserver agreement for Liver Imaging Reporting and Data System (LI-RADS) categories, and image quality between deep learning reconstruction (DLR) and conventional hybrid iterative reconstruction (Hybrid IR) in CT. METHODS: This retrospective study included patients who underwent abdominal dynamic contrast-enhanced CT between October 2021 and March 2022. Arterial, portal, and delayed phase images were reconstructed using DLR and Hybrid IR. Two blinded readers independently read the image sets with detecting HCCs, scoring LI-RADS, and evaluating image quality. RESULTS: A total of 26 patients with HCC (mean age, 73 years ± 12.3) and 23 patients without HCC (mean age, 66 years ± 14.7) were included. The figures of merit (FOM) for the jackknife alternative free-response receiver operating characteristic analysis in detecting HCC averaged for the readers were 0.925 (reader 1, 0.937; reader 2, 0.913) in DLR and 0.878 (reader 1, 0.904; reader 2, 0.851) in Hybrid IR, and the FOM in DLR were significantly higher than that in Hybrid IR (p = 0.038). The interobserver agreement (Cohen's weighted kappa statistics) for LI-RADS categories was moderate for DLR (0.595; 95% CI, 0.585-0.605) and significantly superior to Hybrid IR (0.568; 95% CI, 0.553-0.582). According to both readers, DLR was significantly superior to Hybrid IR in terms of image quality (p ≤ 0.021). CONCLUSION: DLR improved HCC detection, interobserver agreement for LI-RADS categories, and image quality in evaluations of HCC compared to Hybrid IR in abdominal dynamic contrast-enhanced CT.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Fígado , Humanos , Idoso , Carcinoma Hepatocelular/diagnóstico por imagem , Carcinoma Hepatocelular/patologia , Fígado/diagnóstico por imagem , Variações Dependentes do Observador , Aprendizado Profundo , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/patologia , Tomografia por Raios X , Masculino , Feminino , Pessoa de Meia-Idade , Idoso de 80 Anos ou mais
13.
J Asthma ; 60(1): 32-42, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-34962447

RESUMO

OBJECTIVES: We aimed to explore whether large airway remodeling and small airway structural changes exist in subjects with small airway asthma phenotype and to evaluate the relationships between quantitative high-resolution computed tomography (qHRCT) parameters and lung function. METHODS: We enrolled 15 subjects with small airway asthma phenotype and 18 healthy controls. The two groups were matched by age, sex and body square area (BSA) with propensity score matching (PSM). Pulmonary function and qHRCT parameters [wall thickness (WT), wall area (WA), lumen area (LA), wall area percentage (WA%) of the 4th-6th generations in the right upper lobe apical segmental bronchus (RB1), adjusted by BSA, WT/BSA, WA/BSA, and LA/BSA, relative volume change -860 HU to -950 HU (RVC-860 to -950) and the expiration to inspiration ratio of mean lung density (MLDE/I)) were compared between the groups. Correlation analysis was employed to assess the relationship between qHRCT parameters and pulmonary function. RESULTS: The small airway asthma phenotype had significantly higher WA%, RVC-860 to -950 and MLDE/I and lower LA/BSA than the healthy control. Additionally, we found moderate to strong correlations between impulse oscillation (IOS) indices and WA6% and WT6/BSA. No significant correlation was found between bronchial parameters and air trapping parameters (p > 0.05). CONCLUSIONS: Combining physiological tests with imaging approaches can lead to better evaluation of small airway disfunction (SAD) in asthmatic patients. Additionally, despite nonexistent airflow obstruction in patients with small airway asthma phenotype, large airway remodeling and small airway structural changes may appear simultaneously in the early stage of disease.


Assuntos
Asma , Humanos , Remodelação das Vias Aéreas/fisiologia , Asma/diagnóstico por imagem , Brônquios/diagnóstico por imagem , Pulmão/diagnóstico por imagem , Fenótipo , Tomografia por Raios X
14.
Acad Radiol ; 30(5): 855-862, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-35760710

RESUMO

RATIONAL AND OBJECTIVES: Comparison of radiation dose and image quality in routine abdominal and pelvic contrast-enhanced computed tomography (CECT) between a photon-counting detector CT (PCD-CT) and a dual energy dual source CT (DSCT). MATERIALS AND METHODS: 70 oncologic patients (mean age 66 ± 12 years, 29 females) were prospectively enrolled between November 2021 and February 2022. Abdominal CECT were clinically indicated and performed first on a 2nd-generation DSCT and at follow-up on a 1st-generation dual-source PCD-CT. The same contrast media (Imeron 350, Bracco imaging) and pump protocol was used for both scans. For both scanners, polychromatic images were reconstructed with 3mm slice thickness and comparable kernel (I30f[DSCT] and Br40f[PCD-CT]); for PCD-CT data from all counted events above the lowest energy threshold at 20 keV ("T3D") were used. Results were compared in terms of radiation dose metrics of CT dose index (CTDIvol), dose length product (DLP) and size-specific dose estimation (SSDE), objective and subjective measurements of image quality were scored by two emergency radiologists including lesion conspicuity. RESULTS: Median time interval between the scans was 4 months (IQR: 3-6). CNRvessel and SNRvessel of T3D reconstructions from PCD-CT were significantly higher than those of DSCT (all, p < 0.05). Qualitative image noise analysis from PCD-CT and DSCT yielded a mean of 4 each. Lesion conspicuity was rated significantly higher in PCD-CT (Q3 strength) compared to DSCT images. CTDI, DLP and SSDE mean values for PCD-CT and DSCT were 7.98 ± 2.56 mGy vs. 14.11 ± 2.92 mGy, 393.13 ± 153.55 mGy*cm vs. 693.61 ± 185.76 mGy*cm and 9.98 ± 2.41 vs. 14.63 ± 1.63, respectively, translating to a dose reduction of around 32% (SSDE). CONCLUSION: PCD-CT enables oncologic abdominal CT with a significantly reduced dose while keeping image quality similar to 2nd-generation DSCT.


Assuntos
Abdome , Redução da Medicação , Doses de Radiação , Tomografia por Raios X , Tomografia por Raios X/métodos , Abdome/diagnóstico por imagem , Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Intensificação de Imagem Radiográfica
15.
Anal Chem ; 95(4): 2129-2133, 2023 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-36576397

RESUMO

Three-dimensional nondestructive, nanoresolution, and in situ visualization of protein spatial localization in a large, thick single cell remains challenging. In this study, we designed a multifunctional iron oxide (Fe@BFK) nanoprobe that possesses fluorescence and hard X-ray imaging signals. This probe can specifically target the human epidermal growth factor receptor 2 (HER2) protein and help optimize the label condition and selection of suitable samples for X-ray imaging. Combining 30 nm resolution synchrotron radiation hard X-ray nanocomputed tomography and the X-ray-sensitive Fe@BFK nanoprobe, a 3D localization of HER2 on SK-BR-3 cells was obtained for the first time. HER2 was mainly localized and cluster-distributed on the cell membrane with a heterogeneous pattern. This study provides a novel method for the in situ and nondestructive synchrotron radiation imaging of the desired protein localization in large, thick cells and evaluation of the true cellular distribution of a nanoprobe with high resolution.


Assuntos
Tomografia por Raios X , Humanos , Fluorescência
16.
FASEB J ; 37(1): e22681, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36519968

RESUMO

Developing in silico models that accurately reflect a whole, functional cell is an ongoing challenge in biology. Current efforts bring together mathematical models, probabilistic models, visual representations, and data to create a multi-scale description of cellular processes. A realistic whole-cell model requires imaging data since it provides spatial constraints and other critical cellular characteristics that are still impossible to obtain by calculation alone. This review introduces Soft X-ray Tomography (SXT) as a powerful imaging technique to visualize and quantify the mesoscopic (~25 nm spatial scale) organelle landscape in whole cells. SXT generates three-dimensional reconstructions of cellular ultrastructure and provides a measured structural framework for whole-cell modeling. Combining SXT with data from disparate technologies at varying spatial resolutions provides further biochemical details and constraints for modeling cellular mechanisms. We conclude, based on the results discussed here, that SXT provides a foundational dataset for a broad spectrum of whole-cell modeling experiments.


Assuntos
Imageamento Tridimensional , Tomografia por Raios X , Raios X , Imageamento Tridimensional/métodos , Tomografia por Raios X/métodos , Organelas
17.
Rev. otorrinolaringol. cir. cabeza cuello ; 83(3): 249-253, 2023. ilus
Artigo em Espanhol | LILACS | ID: biblio-1522101

RESUMO

El neumoencéfalo es una patología que comúnmente se presenta después de cirugía neuroquirúrgica y ocasionalmente endonasal. Estos se suelen manejar de manera conservadora, sin embargo, se pueden asociar a distintas etiologías las cuales los hacen recurrir. En este reporte presentamos dos casos de neumoencéfalo tardío post quirúrgico asociado a fístulas de LCR de bajo flujo, donde se discute su clínica, etiología y manejo posterior.


Pneumocephalus is a pathology that commonly occurs after endonasal surgery, these are usually managed conservatively, however they can be associated with different etiologies which make them recur. In this report we present two cases of post-surgical late pneumocephalus associated with low-flow CSF fistulae, where its symptoms, etiology, and subsequent management are discussed.


Assuntos
Humanos , Masculino , Pessoa de Meia-Idade , Pneumocefalia/cirurgia , Fístula/líquido cefalorraquidiano , Pneumocefalia/diagnóstico por imagem , Complicações Pós-Operatórias , Imageamento por Ressonância Magnética/métodos , Tomografia por Raios X/métodos
18.
Rev. esp. podol ; 34(1): 52-57, 2023. ilus
Artigo em Espanhol | IBECS | ID: ibc-226674

RESUMO

El uso de los ultrasonidos en el examen, la identificación y el intervencionismo de las diferentes ramas nerviosas del tobillo y del pie son una herramienta de gran apoyo en el ámbito clínico. En la actualidad, la ecografía es un método que se ha ido universalizando en el mundo de la podología, bien por su mayor accesibilidad debido al abaratamiento de los costes, a los avances tecnológicos y a sus beneficios de inocuidad, fácil disponibilidad para el examen inmediato y su aplicación dinámica en la evaluación de las diferentes estructuras anatómicas. El presente trabajo trata de presentar a la comunidad podológica una descripción detallada del mapeo mediante ecografía de los nervios en cara medial del pie. Entendemos que esta descripción puede ayudar a los profesionales en el diagnóstico de las patologías de atrapamiento nervioso a dicho nivel, así como en procedimientos mínimamente invasivos guiados ecográficamente en dicha área anatómica.(AU)


The use of ultrasound in clinical practice is a great tool for the examination, identification and intervention of the different nerve branches in the foot and ankle. Nowadays, sonography is an exploratory method that has been universally expanded in podiatry because of lowering of costs associated to its use, technological progresses and its benefits of safety, disposal for the inmediate clinical exam and its dynamic application in the evaluation of different structures. The aim of the present paper is to present to the podiatry community a detailed description of sonographic mapping of the nerves in the medial side of the ankle. It is intended to help professionals involved in the management of foot ankle disorders regarding the diagnosis of entrapment neuropathies at this level and also to help with minimally invasive treatments sonographically guided.(AU)


Assuntos
Humanos , Masculino , Feminino , Tomografia por Raios X , Pé/diagnóstico por imagem , Tornozelo/diagnóstico por imagem , Nervo Tibial/diagnóstico por imagem , Diagnóstico por Imagem/métodos , Podiatria , Nervo Tibial/anatomia & histologia , Pé/anatomia & histologia , Tornozelo/anatomia & histologia
19.
Viruses ; 14(12)2022 11 27.
Artigo em Inglês | MEDLINE | ID: mdl-36560654

RESUMO

Upon infection, viruses hijack the cell machinery and remodel host cell structures to utilize them for viral proliferation. Since viruses are about a thousand times smaller than their host cells, imaging virus-host interactions at high spatial resolution is like looking for a needle in a haystack. Scouting gross cellular changes with fluorescent microscopy is only possible for well-established viruses, where fluorescent tagging is developed. Soft X-ray tomography (SXT) offers 3D imaging of entire cells without the need for chemical fixation or labeling. Here, we use full-rotation SXT to visualize entire human B cells infected by the herpes simplex virus 1 (HSV-1). We have mapped the temporospatial remodeling of cells during the infection and observed changes in cellular structures, such as the presence of cytoplasmic stress granules and multivesicular structures, formation of nuclear virus-induced dense bodies, and aggregates of capsids. Our results demonstrate the power of SXT imaging for scouting virus-induced changes in infected cells and understanding the orchestration of virus-host remodeling quantitatively.


Assuntos
Herpesvirus Humano 1 , Humanos , Herpesvirus Humano 1/química , Tomografia por Raios X/métodos , Capsídeo
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