scholarly journals A High-Efficiency Super-Resolution Reconstruction Method for Ultrasound Microvascular Imaging

2018 ◽  
Vol 8 (7) ◽  
pp. 1143 ◽  
Author(s):  
Wei Guo ◽  
Yusheng Tong ◽  
Yurong Huang ◽  
Yuanyuan Wang ◽  
Jinhua Yu
Keyword(s):  
Time Resolution ◽  
High Efficiency ◽  
Gaussian Function ◽  
Super Resolution ◽  
Reconstruction Method ◽  
Image Deconvolution ◽  
Clinical Use ◽  
In Vivo Experiments ◽  
Resolution Imaging

The emergence of super-resolution imaging makes it possible to display the microvasculatures clearly using ultrasound imaging, which is of great importance in the early diagnosis of cancer. At present, the super-resolution performance can only be achieved when the sampling signal is long enough (usually more than 10,000 frames). Thus, the imaging time resolution is not suitable for clinical use. In this paper, we proposed a novel super-resolution reconstruction method, which is proved to have a satisfactory resolution using shorter sampling signal sequences. In the microbubble localization step, the integrated form of the 2D Gaussian function is innovatively adopted for image deconvolution in our method, which enhances the accuracy of microbubble positioning. In the trajectory tracking step, for the first time the averaged shifted histogram technique is presented for the visualization, which greatly improves the precision of reconstruction. In vivo experiments on rabbits were conducted to verify the effectiveness of the proposed method. Compared to the conventional reconstruction method, our method significantly reduces the Full-Width-at-Half-Maximum (FWHM) by 50% using only 400-frame signals. Besides, there is no significant increase in the running time using the proposed method. Considering its imaging performance and used frame number, the conclusion can be drawn that the proposed method advances the application of super-resolution imaging to the clinical use with a much higher time resolution.

scholarly journals Differential FSH Glycosylation Modulates FSHR Oligomerization and Subsequent cAMP Signaling

2021 ◽  
Vol 12 ◽  
Author(s):  
Uchechukwu T. Agwuegbo ◽  
Emily Colley ◽  
Anthony P. Albert ◽  
Viktor Y. Butnev ◽  
George R. Bousfield ◽  
...  
Keyword(s):  
Super Resolution ◽  
Hek293 Cells ◽  
Camp Signaling ◽  
Camp Production ◽  
Functional Roles ◽  
Menopausal Women ◽  
Resolution Imaging ◽  
Post Menopausal

Follicle-stimulating hormone (FSH) and its target G protein-coupled receptor (FSHR) are essential for reproduction. Recent studies have established that the hypo-glycosylated pituitary FSH glycoform (FSH21/18), is more bioactive in vitro and in vivo than the fully-glycosylated variant (FSH24). FSH21/18 predominates in women of reproductive prime and FSH24 in peri-post-menopausal women, suggesting distinct functional roles of these FSH glycoforms. The aim of this study was to determine if differential FSH glycosylation modulated FSHR oligomerization and resulting impact on cAMP signaling. Using a modified super-resolution imaging technique (PD-PALM) to assess FSHR complexes in HEK293 cells expressing FSHR, we observed time and concentration-dependent modulation of FSHR oligomerization by FSH glycoforms. High eFSH and FSH21/18 concentrations rapidly dissociated FSHR oligomers into monomers, whereas FSH24 displayed slower kinetics. The FSHR β-arrestin biased agonist, truncated eLHβ (Δ121-149) combined with asparagine56-deglycosylated eLHα (dg-eLHt), increased FSHR homomerization. In contrast, low FSH21/18 and FSH24 concentrations promoted FSHR association into oligomers. Dissociation of FSHR oligomers correlated with time points where higher cAMP production was observed. Taken together, these data suggest that FSH glycosylation may modulate the kinetics and amplitude of cAMP production, in part, by forming distinct FSHR complexes, highlighting potential avenues for novel therapeutic targeting of the FSHR to improve IVF outcomes.

scholarly journals PLANT-DERIVED CHEMOTHERAPEUTICS DRUGS FOR CANCER CHEMOTHERAPY

2021 ◽  
Vol 1 (1) ◽  
pp. 28-37
Author(s):  
Alexandra Dragoi ◽  
Oana Alexandru
Keyword(s):  
Anticancer Agents ◽  
Natural Compounds ◽  
Clinical Use ◽  
Vinca Alkaloids ◽  
Chemotherapeutic Drugs ◽  
Malignant Cells ◽  
In Vivo Experiments ◽  
Whole Plant

Cancer chemotherapeutic drugs acts in different manner to kill malignant cells. Most of the anticancer drugs available in clinical practice to treat cancer patients, are natural products including whole plant extract, crude plant extracts, isolated constituents, plant –based drug formulations etc. These natural compounds have been a basis for the development of several drugs against cancer. Agents such as topotecan, taxol, vinca alkaloids (vincristine, vinblastine, vinorelbine and vindesine), are important anticancer agents in widespread clinical use. Other agents, such as combretastatin, flavopiridol, betulinic acid were shown to have anti-tumor effects in both in vitro and in vivo experiments. In this review, we aim to make a brief description of classical plant-derived chemotherapeutics drugs and also to highlight the importance of these natural compounds in the development of new potential drugs in cancer treatment.

scholarly journals ABHD4-dependent developmental anoikis protects the prenatal brain from pathological insults

2019 ◽  
Author(s):  
Zsófia I. László ◽  
Zsolt Lele ◽  
Miklós Zöldi ◽  
Vivien Miczán ◽  
Fruzsina Mógor ◽  
...  
Keyword(s):  
Progenitor Cells ◽  
Super Resolution ◽  
Loss Of Function ◽  
Fetal Alcohol ◽  
Brain Malformations ◽  
Function Loss ◽  
Resolution Imaging ◽  
Metabolizing Enzyme ◽  
Induced Apoptosis

AbstractIn light of the astronomical number of cell divisions taking place in restricted neurogenic niches, brain malformations caused by ectopic proliferation of misplaced progenitor cells are surprisingly rare. Here, we show that a process we term developmental anoikis distinguishes the abnormal detachment of progenitor cells from the normal delamination of daughter neuroblasts in the developing mouse neocortex. By using in vivo gain-of-function, loss-of-function, and rescue manipulations together with correlated confocal and super-resolution imaging, we identify the endocannabinoid-metabolizing enzyme abhydrolase domain containing 4 (ABHD4) as an essential mediator for the elimination of abnormally detached cells. Consequently, rapid ABHD4 downregulation is necessary for delaminated daughter neuroblasts to escape from anoikis. Moreover, ABHD4 is required for fetal alcohol-induced apoptosis, but not for the well-established form of developmentally controlled programmed cell death. These results suggest that ABHD4-mediated developmental anoikis specifically protects the embryonic brain from the consequences of sporadic delamination errors and teratogenic insults.

scholarly journals The role of high cholesterol in age-related COVID19 lethality

2020 ◽  
Author(s):  
Hao Wang ◽  
Zixuan Yuan ◽  
Mahmud Arif Pavel ◽  
Robert Hobson ◽  
Scott B. Hansen
Keyword(s):  
Viral Entry ◽  
Super Resolution ◽  
The Elderly ◽  
High Cholesterol ◽  
Entry Site ◽  
Age Related ◽  
Entry Points ◽  
Resolution Imaging ◽  
Tissue Cholesterol

ABSTRACTCoronavirus disease 2019 (COVID19) is a respiratory infection caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) originating in Wuhan, China in 2019. The disease is notably severe in elderly and those with underlying chronic conditions. A molecular mechanism that explains why the elderly are vulnerable and why children are resistant is largely unknown. Here we show loading cells with cholesterol from blood serum using the cholesterol transport protein apolipoprotein E (apoE) enhances the entry of pseudotyped SARS-CoV-2 and the infectivity of the virion. Super resolution imaging of the SARS-CoV-2 entry point with high cholesterol shows almost twice the total number of endocytic entry points. Cholesterol concomitantly traffics angiotensinogen converting enzyme (ACE2) to the endocytic entry site where SARS-CoV-2 presumably docks to efficiently exploit entry into the cell. Furthermore, in cells producing virus, cholesterol optimally positions furin for priming SARS-CoV-2, producing a more infectious virion with improved binding to the ACE2 receptor. In vivo, age and high fat diet induces cholesterol loading by up to 40% and trafficking of ACE2 to endocytic entry sites in lung tissue from mice. We propose a component of COVID19 severity based on tissue cholesterol level and the sensitivity of ACE2 and furin to cholesterol. Molecules that reduce cholesterol or disrupt ACE2 localization with viral entry points or furin localization in the producer cells, may reduce the severity of COVID19 in obese patients.

scholarly journals Endoderm and Hepatic Progenitor Cells Engraft in the Quiescent Liver Concurrent with Intrinsically Activated Epithelial-to-Mesenchymal Transition

2021 ◽  
Vol 30 ◽  
pp. 096368972199378
Author(s):  
W. Samuel Fagg ◽  
Naiyou Liu ◽  
Igor Patrikeev ◽  
Omar A. Saldarriaga ◽  
Massoud Motamedi ◽  
...  
Keyword(s):  
Progenitor Cell ◽  
Iron Nanoparticles ◽  
Epithelial To Mesenchymal Transition ◽  
High Efficiency ◽  
Embryonic Stem ◽  
Mesenchymal Transition ◽  
Cell Engraftment ◽  
Resolution Imaging

Stem cell transplantation to the liver is a promising therapeutic strategy for a variety of disorders. Hepatocyte transplantation has short-term efficacy but can be problematic due to portal hypertension, inflammation, and sinusoidal thrombosis. We have previously transplanted small mouse endoderm progenitor (EP) cells to successfully reverse a murine model of hemophilia B, and labeling these cells with iron nanoparticles renders them responsive to magnetic fields, which can be used to enhance engraftment. The mechanisms mediating progenitor cell migration from the sinusoidal space to the hepatocyte compartment are unknown. Here we find human EP and hepatic progenitor (HP) cells can be produced from human embryonic stem cells with high efficiency, and they also readily uptake iron nanoparticles. This provides a simple manner through which one can readily identify transplanted cells in vivo using electron microscopy, shortly after delivery. High resolution imaging shows progenitor cell morphologies consistent with epithelial-to-mesenchymal transition (EMT) mediating invasion into the hepatic parenchyma. This occurs in as little as 3 h, which is considerably faster than observed when hepatocytes are transplanted. We confirmed activated EMT in transplanted cells in vitro, as well as in vivo 24 h after transplantation. We conclude that EMT naturally occurs concurrent with EP and HP cell engraftment, which may mediate the rate, safety, and efficacy of early cell engraftment in the undamaged quiescent liver.

scholarly journals Super-Resolution Microscopy: Shedding New Light on In Vivo Imaging

2021 ◽  
Vol 9 ◽  
Author(s):  
Yingying Jing ◽  
Chenshuang Zhang ◽  
Bin Yu ◽  
Danying Lin ◽  
Junle Qu
Keyword(s):  
Biological Activities ◽  
Super Resolution ◽  
Spatiotemporal Resolution ◽  
The Past ◽  
Relevant Field ◽  
Living Species ◽  
Resolution Imaging ◽  
Super Resolution Microscopy ◽  
Conventional Light Microscopy

Over the past two decades, super-resolution microscopy (SRM), which offered a significant improvement in resolution over conventional light microscopy, has become a powerful tool to visualize biological activities in both fixed and living cells. However, completely understanding biological processes requires studying cells in a physiological context at high spatiotemporal resolution. Recently, SRM has showcased its ability to observe the detailed structures and dynamics in living species. Here we summarized recent technical advancements in SRM that have been successfully applied to in vivo imaging. Then, improvements in the labeling strategies are discussed together with the spectroscopic and chemical demands of the fluorophores. Finally, we broadly reviewed the current applications for super-resolution techniques in living species and highlighted some inherent challenges faced in this emerging field. We hope that this review could serve as an ideal reference for researchers as well as beginners in the relevant field of in vivo super resolution imaging.

scholarly journals A V0-ATPase-dependent apical trafficking pathway maintains the polarity of the intestinal absorptive membrane

2018 ◽  
Author(s):  
Aurélien Bidaud-Meynard ◽  
Ophélie Nicolle ◽  
Markus Heck ◽  
Grégoire Michaux
Keyword(s):  
Brush Border ◽  
Molecular Mechanisms ◽  
Super Resolution ◽  
Structural Defects ◽  
Intestinal Epithelial ◽  
Intestinal Membrane ◽  
Apical Trafficking ◽  
Resolution Imaging ◽  
Trafficking Defects

AbstractIntestine function relies on the strong polarity of intestinal epithelial cells and the array of microvilli forming a brush border at their luminal pole. Combining genetic RNAi screen and in vivo super-resolution imaging in the C. elegans intestine, we uncovered that the V0 sector of the V-ATPase (V0-ATPase) controls a late apical trafficking step, involving RAB-11 endosomes and the SNARE SNAP-29, necessary to maintain the polarized localization of both apical polarity modules and brush border proteins. We show that the V0-ATPase pathway also genetically interacts with glycosphingolipids in enterocyte polarity maintenance. Finally, we demonstrate that depletion of the V0-ATPase fully recapitulates the severe structural, polarity and trafficking defects observed in enterocytes from patients with Microvillus inclusion disease (MVID) and used this new in vivo MVID model to follow the dynamics of microvillus inclusions. Hence, we describe a new function for the V0-ATPase in apical trafficking and epithelial polarity maintenance and the promising use of C. elegans intestine as an in vivo model to better understand the molecular mechanisms of rare genetic enteropathies.Summary statementV0-ATPase controls a late apical trafficking step involved in the maintenance of the apical absorptive intestinal membrane and its depletion phenocopies the trafficking and structural defects of MVID in C. elegans.

scholarly journals Organometallic iron complexes as potential cancer therapeutics.

2014 ◽  
Vol 61 (4) ◽  
Author(s):  
Gabriela Mojžišová ◽  
Ján Mojžiš ◽  
Janka Vašková
Keyword(s):  
Anticancer Agents ◽  
Acquired Resistance ◽  
Cancer Therapeutics ◽  
Iron Complexes ◽  
Cytotoxic Agents ◽  
In Vitro Tests ◽  
Clinical Use ◽  
In Vivo Experiments

Metal-containing drugs have long been used for medicinal purposes in more or less empirical way. The potential of these anticancer agents has only been fully realised and explored since the discovery of the biological activity of cisplatin. Cisplatin and carboplatin have been two of the most successful anti-cancer agents ever developed, and are currently used to treat ovarian, lung and testicular cancers. They share certain side effects, so their clinical use is severely limited by dose-limiting toxicity. Inherent or acquired resistance is a second problem often associated with platinum-based drugs, with further limits of their clinical use. These problems have prompted chemists to employ different strategies in development of the new metal-based anticancer agents with different mechanisms of action. There are various metal complexes still under development and investigation for the future cancer treatment use. In the search for novel bio-organometallic molecules, iron containing anti-tumoral agents are enjoying an increasing interest and appear very promising as the potential drug candidates. Iron, as an essential cofactor in a number of enzymes and physiological processes, may be less toxic than non essential metals, such as platinum. Up to now, some of iron complexes have been tested as cytotoxic agents and found to be endowed with an antitumor activity in several in vitro tests (on cultured cancer cell lines) and few in vivo experiments (e. g. on Ehrlich's ascites carcinoma). Although the precise molecular mechanism is yet to be defined, a number of observations suggest that the reactive oxygen species can play important role in iron-induced cytotoxicty. This review covers some relevant examples of research on the novel iron complexes.

scholarly journals How To Extend The Capabilities Of A Commercial Two-Photon Microscope To Perform Super-Resolution Imaging, Wavelength Mixing And Label-Free Microscopy.

2021 ◽  
Author(s):  
Chiara Peres ◽  
Chiara Nardin ◽  
Guang Yang ◽  
Fabio Mammano
Keyword(s):  
Ex Vivo ◽  
Super Resolution ◽  
Label Free ◽  
Linear Optics ◽  
Non Linear Optics ◽  
Two Photon ◽  
Custom Made ◽  
Non Linear ◽  
Resolution Imaging

Multimodal microscopy combines multiple non-linear techniques that take advantage of different optical processes to generate contrast and increase the amount of information that can be obtained from biological samples. However, the most advanced optical architectures are typically custom-made and require complex alignment procedures, as well as daily maintenance by properly trained personnel for optimal performance. Here, we describe a hybrid system we constructed to overcome these disadvantages by modifying a commercial upright microscope. We show that our multimodal imaging platform can be used to seamlessly perform two-photon STED, wavelength mixing and label-free microscopy in both ex vivo and in vivo samples. The system is highly stable and endowed with remote alignment hardware that ensures simplified operability for non-expert users. This optical architecture is an important step forward towards a wider practical applicability of non-linear optics to bioimaging.

Sign in / Sign up

Export Citation Format

Share Document