In vivo three-dimensional evaluation of tumour hypoxia in nasopharyngeal carcinomas using FMT-CT and MSOT

Abstract Purpose Accurate evaluation of hypoxia is particularly important in patients with nasopharyngeal carcinoma (NPC) undergoing radiotherapy. The aim of this study was to propose a novel imaging strategy for quantitative three-dimensional (3D) evaluation of hypoxia in a small animal model of NPC. Methods A carbonic anhydrase IX (CAIX)-specific molecular probe (CAIX-800) was developed for imaging of hypoxia. Mouse models of subcutaneous, orthotopic, and spontaneous lymph node metastasis from NPC (5 mice per group) were established to assess the imaging strategy. A multi-modality imaging method that consisted of a hybrid combination of fluorescence molecular tomography-computed tomography (FMT-CT) and multispectral optoacoustic tomography (MSOT) was used for 3D quantitative evaluation of tumour hypoxia. Magnetic resonance imaging, histological examination, and immunohistochemical analysis were used as references for comparison and validation. Results In the early stage of NPC (2 weeks after implantation), FMT-CT enabled precise 3D localisation of the hypoxia biomarker with high sensitivity. At the advanced stage (6 weeks after implantation), MSOT allowed multispectral analysis of the biomarker and haemoglobin molecules with high resolution. The combination of high sensitivity and high resolution from FMT-CT and MSOT could not only detect hypoxia in small-sized NPCs but also visualise the heterogeneity of hypoxia in 3D. Conclusions Integration of FMT-CT and MSOT could allow comprehensive and quantifiable evaluation of hypoxia in NPC. These findings may potentially benefit patients with NPC undergoing radiotherapy in the future.

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High-speed volumetric two-photon fluorescence imaging of neurovascular dynamics

Nature Communications ◽

10.1038/s41467-020-19851-1 ◽

2020 ◽

Vol 11 (1) ◽

Cited By ~ 1

Author(s):

Jiang Lan Fan ◽

Jose A. Rivera ◽

Wei Sun ◽

John Peterson ◽

Henry Haeberle ◽

...

Keyword(s):

Blood Flow ◽

High Speed ◽

Laser Scanning ◽

Three Dimensional ◽

Laser Scanning Microscopy ◽

Fluorescence Signal ◽

Imaging Method ◽

Spatiotemporal Resolution ◽

Two Photon

AbstractUnderstanding the structure and function of vasculature in the brain requires us to monitor distributed hemodynamics at high spatial and temporal resolution in three-dimensional (3D) volumes in vivo. Currently, a volumetric vasculature imaging method with sub-capillary spatial resolution and blood flow-resolving speed is lacking. Here, using two-photon laser scanning microscopy (TPLSM) with an axially extended Bessel focus, we capture volumetric hemodynamics in the awake mouse brain at a spatiotemporal resolution sufficient for measuring capillary size and blood flow. With Bessel TPLSM, the fluorescence signal of a vessel becomes proportional to its size, which enables convenient intensity-based analysis of vessel dilation and constriction dynamics in large volumes. We observe entrainment of vasodilation and vasoconstriction with pupil diameter and measure 3D blood flow at 99 volumes/second. Demonstrating high-throughput monitoring of hemodynamics in the awake brain, we expect Bessel TPLSM to make broad impacts on neurovasculature research.

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Super-Resolution Label-free Volumetric Vibrational Imaging

10.1101/2021.01.08.425961 ◽

2021 ◽

Author(s):

Chenxi Qian ◽

Kun Miao ◽

Li-En Lin ◽

Xinhong Chen ◽

Jiajun Du ◽

...

Keyword(s):

High Resolution ◽

Three Dimensional ◽

Super Resolution ◽

Label Free ◽

Fluorescence Techniques ◽

Biological Structures ◽

Imaging Strategy ◽

Endogenous Proteins ◽

Low Efficiency ◽

Protein Rich

Innovations in high-resolution optical imaging have allowed visualization of nanoscale biological structures and connections. However, super-resolution fluorescence techniques, including both optics-oriented and sample-expansion based, are limited in quantification and throughput especially in tissues from photobleaching or quenching of the fluorophores, and low-efficiency or non-uniform delivery of the probes. Here, we report a general sample-expansion vibrational imaging strategy, termed VISTA, for scalable label-free high-resolution interrogations of protein-rich biological structures with resolution down to 82 nm. VISTA achieves decent three-dimensional image quality through optimal retention of endogenous proteins, isotropic sample expansion, and deprivation of scattering lipids. Free from probe-labeling associated issues, VISTA offers unbiased and high-throughput tissue investigations. With correlative VISTA and immunofluorescence, we further validated the imaging specificity of VISTA and trained an image-segmentation model for label-free multi-component and volumetric prediction of nucleus, blood vessels, neuronal cells and dendrites in complex mouse brain tissues. VISTA could hence open new avenues for versatile biomedical studies.

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In vivo bone regeneration assessment of offset and gradient melt electrowritten (MEW) PCL scaffolds

Biomaterials Research ◽

10.1186/s40824-020-00196-1 ◽

2020 ◽

Vol 24 (1) ◽

Author(s):

Naghmeh Abbasi ◽

Ryan S. B. Lee ◽

Saso Ivanovski ◽

Robert M. Love ◽

Stephen Hamlet

Keyword(s):

Bone Regeneration ◽

Size Structure ◽

Three Dimensional ◽

Immunohistochemical Analysis ◽

Repair Process ◽

Micro Computed Tomography ◽

Calvarial Defects ◽

Promising Solution ◽

Poly Caprolactone

Abstract Background Biomaterial-based bone tissue engineering represents a promising solution to overcome reduced residual bone volume. It has been previously demonstrated that gradient and offset architectures of three-dimensional melt electrowritten poly-caprolactone (PCL) scaffolds could successfully direct osteoblast cells differentiation toward an osteogenic lineage, resulting in mineralization. The aim of this study was therefore to evaluate the in vivo osteoconductive capacity of PCL scaffolds with these different architectures. Methods Five different calcium phosphate (CaP) coated melt electrowritten PCL pore sized scaffolds: 250 μm and 500 μm, 500 μm with 50% fibre offset (offset.50.50), tri layer gradient 250–500-750 μm (grad.250top) and 750–500-250 μm (grad.750top) were implanted into rodent critical-sized calvarial defects. Empty defects were used as a control. After 4 and 8 weeks of healing, the new bone was assessed by micro-computed tomography and immunohistochemistry. Results Significantly more newly formed bone was shown in the grad.250top scaffold 8 weeks post-implantation. Histological investigation also showed that soft tissue was replaced with newly formed bone and fully covered the grad.250top scaffold. While, the bone healing did not happen completely in the 250 μm, offset.50.50 scaffolds and blank calvaria defects following 8 weeks of implantation. Immunohistochemical analysis showed the expression of osteogenic markers was present in all scaffold groups at both time points. The mineralization marker Osteocalcin was detected with the highest intensity in the grad.250top and 500 μm scaffolds. Moreover, the expression of the endothelial markers showed that robust angiogenesis was involved in the repair process. Conclusions These results suggest that the gradient pore size structure provides superior conditions for bone regeneration.

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A Novel Method for Automated Acquisition of Tilt Series for Electron Tomography Based on Pre-Calibration of the Specimen Stage

Microscopy and Microanalysis ◽

10.1017/s143192760003823x ◽

2000 ◽

Vol 6 (S2) ◽

pp. 1148-1149

Author(s):

U. Ziese ◽

A.H. Janssen ◽

T.P. van der Krift ◽

A.G. van Balen ◽

W.J. de Ruijter ◽

...

Keyword(s):

High Resolution ◽

3D Reconstruction ◽

Cell Biology ◽

Electron Tomography ◽

Three Dimensional ◽

Imaging Method ◽

3D Images ◽

Tilt Series ◽

3D Information ◽

Structural Arrangements

Electron tomography is a three-dimensional (3D) imaging method with transmission electron microscopy (TEM) that provides high-resolution 3D images of structural arrangements. Conventional TEM images are in first approximation mere 2D-projections of a 3D sample under investigation. With electron tomographya series of images is acquired of a sample that is tilted over a large angular range (±70°) with small angular tilt increments (so called tilt-series). For the subsequent 3D-reconstruction, the images of the tilt series are aligned relative to each other and the 3D-reconstruction is computed. Electron tomography is the only technique that can provide true 3D information with nm-scale resolution of individual and unique samples. For (cell) biology and material science applications the availability of high-resolution 3D images of structural arrangements within individual samples provides unique architectural information that cannot be obtained otherwise. Routine application of electron tomography will comprise a major revolutionary step forward in the characterization of complex materials and cellular arrangements.

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ECG-gated dynamic magnetic resonance imaging method for examination of the pig heart

Acta Veterinaria Hungarica ◽

10.1556/004.49.2001.3.3 ◽

2001 ◽

Vol 49 (3) ◽

pp. 275-284

Author(s):

Zs. Petrási ◽

R. Romvári ◽

G. Bajzik ◽

B. Fenyves ◽

I. Repa ◽

...

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Three Dimensional ◽

Dynamic Magnetic Resonance Imaging ◽

Imaging Method ◽

Resonance Imaging ◽

Dynamic Magnetic Resonance ◽

Heart Cycle ◽

The Right

A dynamic magnetic resonance imaging (MRI) method was developed for in vivo examination of the pig heart. Measurements were carried out on 15 meat-type pigs of different liveweight using a 1.5 T equipment. Inhalation anaesthesia was applied, then data acquisition was synchronised by ECG gating. Depending on the heart rate and heart size, in each case 8 to 10 slices and in each slice 8 to 14 phases were acquired prospectively according to one heart cycle. During the post-processing of the images the left and the right ventricular volumes were determined. The values measured at 106 kg liveweight are 2.5 times higher than those obtained at 22 kg, while the ejection fractions are equal. The calculated cardiac output values were 3.5 l (22 kg, 132 beats/min.), and 6.0 l (106 kg, 91 beats/min.), respectively. After measuring the wall thickness, the contraction values were also determined for the septum (70%), and for the anterior (61%), posterior (41%) and lateral (54%) walls of the left ventricle. Three-dimensional animated models of the ventricles were constructed. Based on the investigations performed, the preconditioning, the anaesthetic procedure, the specific details of ECG measurement and the correct MR imaging technique were worked out.

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High-Resolution Ultrasound Imaging of Human Skin In Vivo by Using Three-Dimensional Ultrasound Microscopy

Ultrasound in Medicine & Biology ◽

10.1016/j.ultrasmedbio.2012.05.012 ◽

2012 ◽

Vol 38 (10) ◽

pp. 1833-1838 ◽

Cited By ~ 21

Author(s):

Kazutoshi Kumagai ◽

Hideyuki Koike ◽

Ryo Nagaoka ◽

Shingo Sakai ◽

Kazuto Kobayashi ◽

...

Keyword(s):

High Resolution ◽

Human Skin ◽

Ultrasound Imaging ◽

Three Dimensional ◽

Ultrasound Microscopy

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Three-Dimensional In Vitro Staphylococcus aureus Abscess Communities Display Antibiotic Tolerance and Protection from Neutrophil Clearance

Infection and Immunity ◽

10.1128/iai.00293-20 ◽

2020 ◽

Vol 88 (11) ◽

Author(s):

Marloes I. Hofstee ◽

Martijn Riool ◽

Igors Terjajevs ◽

Keith Thompson ◽

Martin J. Stoddart ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Immune Cells ◽

Early Stage ◽

Three Dimensional ◽

Collagen Gel ◽

Maximum Size ◽

Human Neutrophils ◽

Content Type

ABSTRACT Staphylococcus aureus is a prominent human pathogen in bone and soft-tissue infections. Pathophysiology involves abscess formation, which consists of central staphylococcal abscess communities (SACs), surrounded by a fibrin pseudocapsule and infiltrating immune cells. Protection against the ingress of immune cells such as neutrophils, or tolerance to antibiotics, remains largely unknown for SACs and is limited by the lack of availability of in vitro models. We describe a three-dimensional in vitro model of SACs grown in a human plasma-supplemented collagen gel. The in vitro SACs reached their maximum size by 24 h and elaborated a fibrin pseudocapsule, as confirmed by electron and immunofluorescence microscopy. The in vitro SACs tolerated 100× the MIC of gentamicin alone and in combination with rifampin, while planktonic controls and mechanically dispersed SACs were efficiently killed. To simulate a host response, SACs were exposed to differentiated PLB-985 neutrophil-like (dPLB) cells and to primary human neutrophils at an early stage of SAC formation or after maturation at 24 h. Both cell types were unable to clear mature in vitro SACs, but dPLB cells prevented SAC growth upon early exposure before pseudocapsule maturation. Neutrophil exposure after plasmin pretreatment of the SACs resulted in a significant decrease in the number of bacteria within the SACs. The in vitro SAC model mimics key in vivo features, offers a new tool to study host-pathogen interactions and drug efficacy assessment, and has revealed the functionality of the S. aureus pseudocapsule in protecting the bacteria from host phagocytic responses and antibiotics.

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