scholarly journals Single-cell radioluminescence microscopy with two-fold higher sensitivity using dual scintillator configuration

2019 ◽  
Author(s):  
Tae Jin Kim ◽  
Qian Wang ◽  
Mark Shelor ◽  
Guillem Pratx
Keyword(s):  
Monte Carlo Simulation ◽  
Imaging Technique ◽  
Single Cells ◽  
Fold Increase ◽  
Cell Uptake ◽  
Acquisition Time ◽  
Proof Of Concept ◽  
Image Acquisition Time ◽  
Geant4 Monte Carlo Simulation ◽  
Higher Sensitivity

AbstractRadioluminescence microscopy (RLM) is an imaging technique that allows quantitative analysis of clinical radiolabeled drugs and probes in single cells. However, the modality suffers from slow data acquisition (10 – 15 minutes), thus critically affecting experiments with short-lived radioactive drugs. To overcome this issue, we suggest an approach that significantly accelerates data collection. Instead of using a single scintillator to image the decay of radioactive molecules, we sandwiched the radiolabeled cells between two scintillators. As proof of concept, we imaged cells labeled with [18F]FDG, a radioactive glucose popularly used in oncology to image tumors. Results show that the double scintillator configuration increases the microscope sensitivity by two-fold, thus reducing the image acquisition time by half to achieve the same result as the single scintillator approach. The experimental results were also compared with Geant4 Monte Carlo simulation to confirm the two-fold increase in sensitivity with only minor degradation in spatial resolution. Overall, these findings suggest that the double scintillator configuration can be used to perform time-sensitive studies such as cell pharmacokinetics or cell uptake of short-lived radiotracers.

scholarly journals 3D phonon microscopy with sub-micron axial-resolution

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Richard J. Smith ◽  
Fernando Pérez-Cota ◽  
Leonel Marques ◽  
Matt Clark
Keyword(s):  
Signal To Noise Ratio ◽  
Single Cells ◽  
Optical Resolution ◽  
Acquisition Time ◽  
Label Free ◽  
Axial Resolution ◽  
Force Microscopy ◽  
Atomic Force ◽  
Accuracy And Precision ◽  
Good Agreement

AbstractBrillouin light scattering (BLS) is an emerging method for cell imaging and characterisation. It allows elasticity-related contrast, optical resolution and label-free operation. Phonon microscopy detects BLS from laser generated coherent phonon fields to offer an attractive route for imaging since, at GHz frequencies, the phonon wavelength is sub-optical. Using phonon fields to image single cells is challenging as the signal to noise ratio and acquisition time are often poor. However, recent advances in the instrumentation have enabled imaging of fixed and living cells. This work presents the first experimental characterisation of phonon-based axial resolution provided by the response to a sharp edge. The obtained axial resolution is up to 10 times higher than that of the optical system used to take the measurements. Validation of the results are obtained with various polymer objects, which are in good agreement with those obtained using atomic force microscopy. Edge localisation, and hence profilometry, of a phantom boundary is measured with accuracy and precision of approximately 60 nm and 100 nm respectively. Finally, 3D imaging of fixed cells in culture medium is demonstrated.

T2-weighted spin-echo pulse sequence with variable repetition and echo times for reduction of MR image acquisition time.

Radiology ◽  
1991 ◽  
Vol 180 (2) ◽  
pp. 551-556 ◽  
Author(s):  
R K Butts ◽  
F Farzaneh ◽  
S J Riederer ◽  
J N Rydberg ◽  
R C Grimm
Keyword(s):  
Pulse Sequence ◽  
Spin Echo ◽  
Image Acquisition ◽  
Acquisition Time ◽  
Mr Image ◽  
Image Acquisition Time ◽  
Echo Pulse

scholarly journals Collagen I triggers directional migration, invasion and matrix remodeling of stroma cells in a 3D spheroid model of endometriosis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Anna Stejskalová ◽  
Victoria Fincke ◽  
Melissa Nowak ◽  
Yvonne Schmidt ◽  
Katrin Borrmann ◽  
...  
Keyword(s):  
Single Cells ◽  
Fold Increase ◽  
Experimental Models ◽  
Collagen I ◽  
Matrix Remodeling ◽  
Clinical Tool ◽  
Directional Migration ◽  
Endometrial Cells ◽  
Small Molecule Drugs ◽  
Actomyosin Contraction

AbstractEndometriosis is a painful gynecological condition characterized by ectopic growth of endometrial cells. Little is known about its pathogenesis, which is partially due to a lack of suitable experimental models. Here, we use endometrial stromal (St-T1b), primary endometriotic stromal, epithelial endometriotic (12Z) and co-culture (1:1 St-T1b:12Z) spheroids to mimic the architecture of endometrium, and either collagen I or Matrigel to model ectopic locations. Stromal spheroids, but not single cells, assumed coordinated directional migration followed by matrix remodeling of collagen I on day 5 or 7, resembling ectopic lesions. While generally a higher area fold increase of spheroids occurred on collagen I compared to Matrigel, directional migration was not observed in co-culture or in 12Z cells. The fold increase in area on collagen I was significantly reduced by MMP inhibition in stromal but not 12Z cells. Inhibiting ROCK signalling responsible for actomyosin contraction increased the fold increase of area and metabolic activity compared to untreated controls on Matrigel. The number of protrusions emanating from 12Z spheroids on Matrigel was decreased by microRNA miR-200b and increased by miR-145. This study demonstrates that spheroid assay is a promising pre-clinical tool that can be used to evaluate small molecule drugs and microRNA-based therapeutics for endometriosis.

scholarly journals Reduction of Acquisition time using Partition of the sIgnal Decay in Spectroscopic Imaging technique (RAPID-SI)

PLoS ONE ◽  
2018 ◽  
Vol 13 (11) ◽  
pp. e0207015 ◽  
Author(s):  
Sourav Bhaduri ◽  
Patricia Clement ◽  
Eric Achten ◽  
Hacene Serrai
Keyword(s):  
Imaging Technique ◽  
Spectroscopic Imaging ◽  
Acquisition Time ◽  
Signal Decay

scholarly journals RNAs as proximity labeling media for identifying nuclear speckle positions relative to the genome

2018 ◽  
Author(s):  
Weizhong Chen ◽  
Zhangming Yan ◽  
Simin Li ◽  
Norman Huang ◽  
Xuerui Huang ◽  
...  
Keyword(s):  
Rna Splicing ◽  
Genomic Sequence ◽  
Single Cells ◽  
Regulation Of Gene Expression ◽  
Nuclear Genome ◽  
Fold Increase ◽  
Nuclear Speckles ◽  
Nuclear Speckle ◽  
Interaction Sites ◽  
Genomic Regions

AbstractNuclear speckles are interchromatin structures enriched in RNA splicing factors. Determining their relative positions with respect to the folded nuclear genome could provide critical information on co-and post-transcriptional regulation of gene expression. However, it remains challenging to identify which parts of the nuclear genome are in proximity to nuclear speckles, due to physical separation between nuclear speckle cores and chromatin. We hypothesized that noncoding RNAs including small nuclear RNAs, 7SK and Malat1, which accumulate at the periphery of nuclear speckles (nsaRNA,nuclearspeckleassociated RNA), may extend to sufficient proximity to the nuclear genome. Leveraging a transcriptome-genome interaction assay (MARGI), we identified nsaRNA-interacting genomic sequences, which exhibited clustering patterns (nsaPeaks) in the genome, suggesting existence of relatively stable interaction sites for nsaRNAs in nuclear genome. Posttranscriptional pre-mRNAs, which are known to be clustered to nuclear speckles, exhibited proximity to nsaPeaks but rarely to other genomic regions. Furthermore, CDK9 proteins that localize to the vicinity of nuclear speckles produced ChIP-seq peaks that overlapped with nsaPeaks. Our combined DNA FISH and immunofluorescence analysis in 182 single cells revealed a 3-fold increase in odds for nuclear speckles to localize near an nsaPeak than its neighboring genomic sequence. These data suggest a model that nsaRNAs locate in sufficient proximity to nuclear genome and leave identifiable genomic footprints, thus revealing the parts of genome proximal to nuclear speckles.

In-vivo near-infrared optical imaging of growing osteosarcoma cell lesions xenografted in mice: dual-channel quantitative evaluation of volume and mineralization

2011 ◽  
Vol 52 (9) ◽  
pp. 978-988 ◽  
Author(s):  
Hitoshi Nakayama ◽  
Tomoyuki Kawase ◽  
Kazuhiro Okuda ◽  
Larry F Wolff ◽  
Hiromasa Yoshie
Keyword(s):  
Optical Imaging ◽  
Near Infrared ◽  
Imaging Technique ◽  
Ex Vivo ◽  
Acquisition Time ◽  
Osteosarcoma Cell ◽  
Dual Channel ◽  
Nir Imaging ◽  
Ex Vivo Imaging

Background In a previous study using a rodent osteosarcoma-grafted rat model, in which cell-dependent mineralization was previously demonstrated to proportionally increase with growth, we performed a quantitative analysis of mineral deposit formation using 99mTc-HMDP and found some weaknesses, such as longer acquisition time and narrower dynamic ranges (i.e. images easily saturated). The recently developed near-infrared (NIR) optical imaging technique is expected to non-invasively evaluate changes in living small animals in a quantitative manner. Purpose To test the feasibility of NIR imaging with a dual-channel system as a better alternative for bone scintigraphy by quantitatively evaluating mineralization along with the growth of osteosarcoma lesions in a mouse-xenograft model. Material and Methods The gross volume and mineralization of osteosarcoma lesions were evaluated in living mice simultaneously with dual-channels by NIR dye-labeled probes, 2-deoxyglucose (DG) and pamidronate (OS), respectively. To verify these quantitative data, retrieved osteosarcoma lesions were then subjected to ex-vivo imaging, weighing under wet conditions, microfocus-computed tomography (μCT) analysis, and histopathological examination. Results Because of less scattering and no anatomical overlapping, as generally shown, specific fluorescence signals targeted to the osteosarcoma lesions could be determined clearly by ex-vivo imaging. These data were well positively correlated with the in-vivo imaging data ( r > 0.8, P < 0.02). Other good to excellent correlations ( r > 0.8, P < 0.02) were observed between DG accumulation and tumor gross volume and between OS accumulation and mineralization volume. Conclusion This in-vivo NIR imaging technique using DG and OS is sensitive to the level to simultaneously detect and quantitatively evaluate the growth and mineralization occuring in this type of osteosarcoma lesions of living mice without either invasion or sacrifice. By possible mutual complementation, this dual imaging system might be useful for accurate diagnosis even in the presence of overlapping tissues.

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