As Clear as a Cell: Researchers See Deeper into Tissue than Ever Before

2013 ◽  
Vol 21 (4) ◽  
pp. 10-13 ◽  
Author(s):  
Brendan Brinkman
Keyword(s):  
Nervous System ◽  
Light Scattering ◽  
Brain Tissue ◽  
Organizational Context ◽  
High Specificity ◽  
Mouse Embryos ◽  
Thin Sections ◽  
A Cell ◽  
Serial Section Reconstruction ◽  
Anterograde Labeling

Researchers have long sought to visualize neural projections and other features of animal brains by imaging them using light microscopes. Connectomics studies strive to elucidate the connections among nerve cells, but brain is dense, and gray matter is tremendously light-scattering. So scientists have not been able to peer as deeply into brain tissue as is necessary to view its complex connections and structures without cutting brain tissue into thin sections. The slicing causes damage that makes it even more difficult to reconstruct exactly how nervous system structures are interconnected. Issues with light scattering have also limited studies of microvasculature, developmental structures, and other features in mouse embryos and other tissues. Traditional methods of retrograde or anterograde labeling have been able to provide high specificity of connection circuitry, but at the price of losing the organizational context of the network. In addition, there is a limit to the practical number of labels that can be used at once. Even multicolor methods have required serial section reconstruction.

scholarly journals A cell-based drug delivery platform for treating central nervous system inflammation

2021 ◽  
Author(s):  
Oren Levy ◽  
Veit Rothhammer ◽  
Ivan Mascanfroni ◽  
Zhixiang Tong ◽  
Rui Kuai ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Central Nervous System ◽  
Nervous System ◽  
Central Nervous System Inflammation ◽  
Delivery Platform ◽  
A Cell

Effects of an injectable functionalized self-assembling nanopeptide hydrogel on angiogenesis and neurogenesis for regeneration of the central nervous system

Nanoscale ◽  
2017 ◽  
Vol 9 (42) ◽  
pp. 16281-16292 ◽  
Author(s):  
Tzu-Wei Wang ◽  
Kai-Chieh Chang ◽  
Liang-Hsin Chen ◽  
Shih-Yung Liao ◽  
Chia-Wei Yeh ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Brain Tissue ◽  
Tissue Regeneration ◽  
Self Assembling ◽  
System P ◽  
Injured Brain ◽  
The Central Nervous System

Functionalised self-assembling nanopeptide hydrogel mediates angiogenesis and neurogenesis for injured brain tissue regeneration.

scholarly journals Detailed analysis of public RNAseq data and long non-coding RNA: a proposed enhancement to mesenchymal stem cell characterisation

2020 ◽  
Author(s):  
Sebastien Riquier ◽  
Marc Mathieu ◽  
Anthony Boureux ◽  
Florence Ruffle ◽  
Jean-Marc Lemaitre ◽  
...  
Keyword(s):  
Stem Cells ◽  
High Specificity ◽  
Experimental Investigations ◽  
Bioinformatics Pipeline ◽  
Multipotent Stem Cells ◽  
Non Coding Rna ◽  
Rnaseq Data ◽  
A Cell ◽  
Public Datasets ◽  
And Function

AbstractThe development of RNA sequencing (RNAseq) and corresponding emergence of public datasets have created new avenues of transcriptional marker search. The long non-coding RNAs (lncRNAs) constitute an emerging class of transcripts with a potential for high tissue specificity and function. Using a dedicated bioinformatics pipeline, we propose to construct a cell-specific catalogue of unannotated lncRNAs and to identify the strongest cell markers. This pipeline uses ab initio transcript identification, pseudoalignment and new methodologies such as a specific k-mer approach for naive quantification of expression in numerous RNAseq data.For an application model, we focused on Mesenchymal Stem Cells (MSCs), a type of adult multipotent stem-cells of diverse tissue origins. Frequently used in clinics, these cells lack extensive characterisation. Our pipeline was able to highlight different lncRNAs with high specificity for MSCs. In silico methodologies for functional prediction demonstrated that each candidate represents one specific state of MSCs biology. Together, these results suggest an approach that can be employed to harness lncRNA as cell marker, showing different candidates as potential actors in MSCs biology, while suggesting promising directions for future experimental investigations.

scholarly journals Investigating the Central Nervous System Disposition of Actinomycin D: Implementation and Evaluation of Cerebral Microdialysis and Brain Tissue Measurements Supported by UPLC-MS/MS Quantification

Pharmaceutics ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1498
Author(s):  
Julia Benzel ◽  
Gzona Bajraktari-Sylejmani ◽  
Philipp Uhl ◽  
Abigail Davis ◽  
Sreenath Nair ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Brain Tissue ◽  
Actinomycin D ◽  
Tissue Concentration ◽  
Cerebral Microdialysis ◽  
Tissue Homogenate ◽  
In Vitro Experiments ◽  
Plasma Ratio

Actinomycin D is a potent cytotoxic drug against pediatric (and other) tumors that is thought to barely cross the blood–brain barrier. To evaluate its potential applicability for the treatment of patients with central nervous system (CNS) tumors, we established a cerebral microdialysis model in freely moving mice and investigated its CNS disposition by quantifying actinomycin D in cerebral microdialysate, brain tissue homogenate, and plasma. For this purpose, we developed and validated an ultraperformance liquid chromatography–tandem mass spectrometry assay suitable for ultra-sensitive quantification of actinomycin D in the pertinent biological matrices in micro-samples of only 20 µL, with a lower limit of quantification of 0.05 ng/mL. In parallel, we confirmed actinomycin D as a substrate of P-glycoprotein (P-gp) in in vitro experiments. Two hours after intravenous administration of 0.5 mg/kg, actinomycin D reached total brain tissue concentrations of 4.1 ± 0.7 ng/g corresponding to a brain-to-plasma ratio of 0.18 ± 0.03, while it was not detectable in intracerebral microdialysate. This tissue concentration exceeds the concentrations of actinomycin D that have been shown to be effective in in vitro experiments. Elimination of the drug from brain tissue was substantially slower than from plasma, as shown in a brain-to-plasma ratio of approximately 0.53 after 22 h. Because actinomycin D reached potentially effective concentrations in brain tissue in our experiments, the drug should be further investigated as a therapeutic agent in potentially susceptible CNS malignancies, such as ependymoma.

scholarly journals CRISPR-mediated isogenic cell-SELEX approach for generating highly specific aptamers against native membrane proteins

2020 ◽  
Author(s):  
Jonah C. Rosch ◽  
Emma H. Neal ◽  
Daniel A. Balikov ◽  
Mohsin Rahim ◽  
Ethan S. Lippmann
Keyword(s):  
Membrane Proteins ◽  
Glucose Transporter ◽  
High Specificity ◽  
Epithelial Cell Line ◽  
Target Cells ◽  
Wild Type ◽  
Simultaneous Exposure ◽  
Affinity Reagents ◽  
A Cell

AbstractIntroductionThe generation of affinity reagents that bind native membrane proteins with high specificity remains challenging. Most in vitro selection paradigms utilize different cell types for positive and negative rounds of selection (where the positive selection is against a cell that expresses the desired membrane protein and the negative selection is against a cell that lacks the protein). However, this strategy can yield affinity reagents that bind unintended membrane proteins on the target cells. To address this issue, we developed a systematic evolution of ligands by exponential enrichment (SELEX) scheme that utilizes isogenic pairs of cells generated via CRISPR techniques.MethodsUsing a Caco-2 epithelial cell line with constitutive Cas9 expression, we knocked out the SLC2A1 gene (encoding the GLUT1 glucose transporter) via lipofection with synthetic gRNAs. Cell-SELEX rounds were carried out against wild-type and GLUT1-null cells using a single-strand DNA (ssDNA) library. Next-generation sequencing (NGS) was used to quantify enrichment of prospective binders to the wild-type cells.Results10 rounds of cell-SELEX were conducted via simultaneous exposure of ssDNA pools to wild-type and GLUT1-null Caco-2 cells under continuous perfusion. The top binders identified from NGS were validated by flow cytometry and immunostaining for their specificity to the GLUT1 receptor.ConclusionsOur data indicate that highly specific aptamers can be isolated with a SELEX strategy that utilizes isogenic cell lines. This approach should be broadly useful for generating affinity reagents that selectively bind to membrane proteins in their native conformations on the cell surface.

scholarly journals A rapid and affordable point of care test for antibodies against SARS-CoV-2 based on hemagglutination and artificial intelligence interpretation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Vanessa Redecke ◽  
Kazuki Tawaratsumida ◽  
Erin T. Larragoite ◽  
Elizabeth S. C. P. Williams ◽  
Vicente Planelles ◽  
...  
Keyword(s):  
Test Performance ◽  
Learning Algorithm ◽  
Point Of Care ◽  
Method Comparison ◽  
High Specificity ◽  
Turnaround Time ◽  
Analysis Tool ◽  
Point Of Care Test ◽  
Specificity And Sensitivity ◽  
A Cell

AbstractDiagnostic tests that detect antibodies (AB) against SARS-CoV-2 for evaluation of seroprevalence and guidance of health care measures are important tools for managing the COVID-19 pandemic. Current tests have certain limitations with regard to turnaround time, costs and availability, particularly in point-of-care (POC) settings. We established a hemagglutination-based AB test that is based on bi-specific proteins which contain a dromedary-derived antibody (nanobody) binding red blood cells (RBD) and a SARS-CoV-2-derived antigen, such as the receptor-binding domain of the Spike protein (Spike-RBD). While the nanobody mediates swift binding to RBC, the antigen moiety directs instantaneous, visually apparent hemagglutination in the presence of SARS-CoV-2-specific AB generated in COVID-19 patients or vaccinated individuals. Method comparison studies with assays cleared by emergency use authorization demonstrate high specificity and sensitivity. To further increase objectivity of test interpretation, we developed an image analysis tool based on digital image acquisition (via a cell phone) and a machine learning algorithm based on defined sample-training and -validation datasets. Preliminary data, including a small clinical study, provides proof of principle for test performance in a POC setting. Together, the data support the interpretation that this AB test format, which we refer to as ‘NanoSpot.ai’, is suitable for POC testing, can be manufactured at very low costs and, based on its generic mode of action, can likely be adapted to a variety of other pathogens.

Spalt modifies EGFR-mediated induction of chordotonal precursors in the embryonic PNS of Drosophila promoting the development of oenocytes

Development ◽  
2001 ◽  
Vol 128 (5) ◽  
pp. 711-722 ◽  
Author(s):  
T.E. Rusten ◽  
R. Cantera ◽  
J. Urban ◽  
G. Technau ◽  
F.C. Kafatos ◽  
...  
Keyword(s):  
Nervous System ◽  
Cell Fate ◽  
System Development ◽  
Cell Types ◽  
Nervous System Development ◽  
Dual Function ◽  
Evolutionarily Conserved ◽  
A Cell ◽  
And Migration

Genes of the spalt family encode nuclear zinc finger proteins. In Drosophila melanogaster, they are necessary for the establishment of head/trunk identity, correct tracheal migration and patterning of the wing imaginal disc. Spalt proteins display a predominant pattern of expression in the nervous system, not only in Drosophila but also in species of fish, mouse, frog and human, suggesting an evolutionarily conserved role for these proteins in nervous system development. Here we show that Spalt works as a cell fate switch between two EGFR-induced cell types, the oenocytes and the precursors of the pentascolopodial organ in the embryonic peripheral nervous system. We show that removal of spalt increases the number of scolopodia, as a result of extra secondary recruitment of precursor cells at the expense of the oenocytes. In addition, the absence of spalt causes defects in the normal migration of the pentascolopodial organ. The dual function of spalt in the development of this organ, recruitment of precursors and migration, is reminiscent of its role in tracheal formation and of the role of a spalt homologue, sem-4, in the Caenorhabditis elegans nervous system.

On serological distinction between infiltrating neoplasm (glioma) and normal brain tissue

1935 ◽  
Vol 31 (1) ◽  
pp. 137-137
Author(s):  
Н. Reichner
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Brain Tissue ◽  
Normal Brain ◽  
Normal Brain Tissue ◽  
Structural Differences ◽  
The Central Nervous System

Thanks to the work of Vitebsky and Behrens, it became known that within the neuroectoderm itself it is possible to detect immunospecific structural differences that indicate a certain organ, possibly a functionally specific imprint of individual parts of the tissue of the central nervous system.

scholarly journals Source of Early Regenerating Axons in Lamprey Spinal Cord Revealed by Wholemount Optical Clearing with BABB

Cells ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 2427 ◽  
Author(s):  
Guixin Zhang ◽  
William Rodemer ◽  
Isabelle Sinitsa ◽  
Jianli Hu ◽  
Michael E. Selzer
Keyword(s):  
Spinal Cord ◽  
Central Nervous System ◽  
Nervous System ◽  
Confocal Microscopy ◽  
Axon Regeneration ◽  
Benzyl Benzoate ◽  
Optical Clearing ◽  
Propriospinal Neurons ◽  
Early Regeneration ◽  
Anterograde Labeling

Many studies of axon regeneration in the lamprey focus on 18 pairs of large identified reticulospinal (RS) neurons, whose regenerative abilities have been individually quantified. Their axons retract during the first 2 weeks after transection (TX), and many grow back to the site of injury by 4 weeks. However, locomotor movements begin before 4 weeks and the lesion is invaded by axons as early as 2 weeks post-TX. The origins of these early regenerating axons are unknown. Their identification could be facilitated by studies in central nervous system (CNS) wholemounts, particularly if spatial resolution and examination by confocal microscopy were not limited by light scattering. We have used benzyl alcohol/benzyl benzoate (BABB) clearing to enhance the resolution of neuronal perikarya and regenerated axons by confocal microscopy in lamprey CNS wholemounts, and to assess axon regeneration by retrograde and anterograde labeling with fluorescent dye applied to a second TX caudal or rostral to the original lesion, respectively. We found that over 50% of the early regenerating axons belonged to small neurons in the brainstem. Some propriospinal neurons located close to the TX also contributed to early regeneration. The number of early regenerating propriospinal neurons decreased with distance from the original lesion. Descending axons from the brainstem were labeled anterogradely by application of tracer to a second TX close to the spinal–medullary junction. This limited contamination of the data by regenerating spinal axons whose cell bodies are located rostral or caudal to the TX and confirmed the regeneration of many small RS axons as early as 2 weeks post-TX. Compared with the behavior of axotomized giant axons, the early regenerating axons were of small caliber and showed little retraction, probably because they resealed rapidly after injury.

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