We would like to acknowledge our colleague Dr. Jalaiah Varikooty who provided insight and expertise on the topic of the lid wiper, that greatly assisted this research.

Ethics statement: Prior to collecting cells from human subjects, informed consent and ethics approval must be obtained.
1. Prepare Stain
NOTE: Prepare stain on day of experiment.
<ol>
	<li>Add 5 &#181;l Ethidium (or 4 &#181;M) and 5 &#181;l Calcein AM (or 4 &#181;M) to 2.5 ml phosphate buffered saline (PBS) in 15 ml centrifuge tube; mix. Wrap in aluminum foil to shield from light and store at RT until use.</li>
</ol>
2. Collect Cells
<ol>
	<li>Remove cell culture inserts from their package and label for each eyelid to be sampled. Mark orientation of cell collection on the side of the membrane plastic holder using permanent marker. Conduct slit lamp inspection at moderate magnification (approximately 20X) to confirm appropriate health of the region to undergo IC.</li>
	<li>Dispense one drop of topical anesthetic (0.5% proparacaine hydrochloride) in the lower conjunctival sac of each eye and instruct participant to keep eyes closed for one minute.</li>
	<li>Evert upper eye lid and hold in place by the lashes; avoid any contact with the lid wiper area. 
	Optional: the aid of a secondary investigator may be required to perform this step.</li>
	<li>Apply membrane perpendicularly onto the central part of the lid wiper region with minimal pressure.</li>
	<li>Hold membrane in place for 3 - 5 sec. Observe the membrane become translucent in the contact area. At this point, gently remove the membrane and permit the participant&#39;s lid to &#34;flip&#34; back into place.</li>
	<li>Promptly apply one drop of PBS to the sample, to prevent it from drying out. Membrane will turn translucent and should not turn opaque at any time, as this indicates drying. Have the secondary investigator proceed immediately with processing of samples (section 3).</li>
	<li>Conduct final eye check to ensure integrity of the conjunctiva. Dispense ocular lubricants and instruct participant to avoid rubbing their eyes until anesthetic effect wears off (approx. 15 min).</li>
</ol>
3. Sample Processing
<ol>
	<li>Using micro-scissors, cut the membrane in half (one half for each of the downstream analyses), perpendicular through the middle of the cell collection. Cut along the outer margin of one membrane half to separate it from the plastic holder; avoid interaction with the collected cells on the membrane, including ensuring that the membrane does not fold onto itself.</li>
	<li>Secure the membrane using tweezers before completely detaching from holder. Place membrane into labelled 2 ml centrifuge tube containing 500 &#181;l of 95% (v/v) ethanol and leave to fix for a minimum of 20 min to a maximum of 2 hr before processing (section 4.2).</li>
	<li>Immediately separate second half of membrane (as described in section 3.2) and promptly proceed with section 4.1.</li>
</ol>
4. Sample Staining
<ol>
	<li>Immunocytochemical Staining
	<ol>
		<li>Carefully place membrane in 35 mm glass bottom culture dish with collection side facing down; ensure membrane is flat.</li>
		<li>Pipette 20 &#181;l of immunocytochemical stain composition assembled in section 1 on to the membrane. If sample curls up, use disposable pipette tips to carefully flatten the membrane by pushing its edges down. Avoid contact with cell collection areas.</li>
		<li>Gently cover the membrane with glass cover slip. Avoid unnecessary movement of sample. Cover dish with lid and seal with lab-film around the edges. Do not obstruct transparency of dish (top and bottom) and visibility of sample. Label with lab marker.</li>
		<li>Immediately proceed with imaging (section 5.1), then return to section 4.2 to continue with cytological staining of the other half of the membrane.</li>
	</ol>
	</li>
	<li>Cytological Staining
	<ol>
		<li>Gradually hydrate membrane by slowly adding 500 &#181;l of distilled water to the tube used for fixation in section 3.4. Aspirate contents several times into pipette tip to mix, then remove contents.</li>
		<li>Add 500 &#181;l of distilled water. Let stand for a few seconds, then remove. Add 500 &#181;l of Alcian Blue stain and leave for 3 min. Remove stain and perform 3 consecutive 500 &#181;l distilled water rinses or until liquid rinses clear.</li>
		<li>Add 500 &#181;l of Hematoxylin # 1 stain and leave for 3 min. Remove stain and perform three consecutive 500 &#181;l distilled water rinses or until liquid rinses clear. Dehydrate (reverse of section 4.2.1) by aspirating the clear liquid.</li>
		<li>Add 500 &#181;l of Papanicolaou OG-6 stain and leave for 3 min. Remove stain and perform one 500 &#181;l 95% (v/v) ethanol rinse.</li>
		<li>Add 500 &#181;l of Papanicolaou EA-65 stain and leave for 3 min. Remove stain and perform 3 consecutive 500 &#181;l 95% (v/v) ethanol rinses.</li>
		<li>Fully dehydrate using three consecutive 500 &#181;l 100% ethanol rinses. Using tweezers, remove sample from solution; avoid touching cell collection areas.</li>
		<li>Place membrane on glass slide; ensure that cell collection line is either parallel or perpendicular to slide margin for easier alignment during imaging.</li>
		<li>Apply a drop of 100% ethanol and cover with glass slip. Immediately proceed with imaging (section 5.2).</li>
	</ol>
	</li>
</ol>
5. Sample Imaging
<ol>
	<li>Imaging Fluorescent Immunocytochemical Stains
	<ol>
		<li>Use a confocal laser scanning microscope (CLSM)11 or fluorescence microscope12, equipped with a digital color camera, connected to a computer running an image acquisition software. Due to the samples being contained within culture dishes, an inverted microscope may be necessary.</li>
		<li>Set up microscope11,12 according to absorption and emission spectra of ethidium homodimer-1 (528/617 nm Ex/Em maxima in the presence of DNA) and calcein AM (494/517 nm Ex/Em maxima).</li>
		<li>Select the microscope&#39;s lowest magnification (e.g., 2.5X objective) and activate the digital imaging system; observe the sample displayed on the computer monitor.</li>
		<li>Inspect sample for cellular features of interest.</li>
		<li>Select desired microscope magnification and acquire images using imaging software.</li>
		<li>Save files in either native microscope file format or an uncompressed file format (e.g., *.raw, *.tiff).</li>
	</ol>
	</li>
	<li>Imaging Cytological Stains
	<ol>
		<li>Use a standard laboratory bright-field microscope with no filters, equipped with a digital color camera, connected to a computer running an image acquisition software.</li>
		<li>Place and lock glass slide (from step 4.2.8) on microscope stage. Rehydrate sample with 100% ethanol as needed, throughout the entire imaging procedure.</li>
		<li>Select the microscope&#39;s lowest magnification (e.g., 2.5X objective) and activate the digital imaging system; observe the sample displayed on the computer monitor.</li>
		<li>Ensure cell collection is aligned with either X or Y axis of microscope stage control. Adjust if needed, by removing the cover slip and rotating the sample using a pipette tip or tweezers.</li>
		<li>Using the imaging software, capture image(s) of the entire sample with the lowest microscope magnification.</li>
		<li>Switch to moderate microscope magnification (e.g., 10 - 20X objective) and adjust microscope light source and software imaging parameters (exposure, contrast, white balance, etc.), and disable their automated software metering. Save these settings for future use.</li>
		<li>Determine beginning and end points of scan (e.g., top left and bottom right corners of cell collection).</li>
		<li>Using the imaging software, capture image(s) of the entire cell collection area within the starting and end points. Ensure a 20% side-to-side and top-to-bottom overlap between all adjacent images.</li>
		<li>Save files using the native microscope file format or an uncompressed file format (e.g., *.raw, *.tiff).</li>
		<li>Generate final panoramic image using automated stitching software of choice (e.g., Adobe Photoshop Elements). Use reference images taken at step 5.2.5) to confirm the accuracy of the automated stitching in the final image.</li>
	</ol>
	</li>
</ol>

<ol>
	<li>Barbato, G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Diurnal+variation+in+spontaneous+eye-blink+rate.">Diurnal variation in spontaneous eye-blink rate.</a> Psychiatry Res. 93, 145-151 (2000).</li><li>Korb, D. R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lid-Wiper+Epitheliopathy+and+Dry-Eye+Symptoms+in+Contact+Lens+Wearers.">Lid-Wiper Epitheliopathy and Dry-Eye Symptoms in Contact Lens Wearers.</a> Eye &amp; Contact Lens. 28, 211-216 (2002).</li><li>Dumbleton, K., Woods, C. A., Jones, L. W., Fonn, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+impact+of+contemporary+contact+lenses+on+contact+lens+discontinuation.">The impact of contemporary contact lenses on contact lens discontinuation.</a> Eye &amp; Contact Lens. 39, 93-99 (2013).</li><li>Roba, M., Duncan, E., Hill, G., Spencer, N., Tosatti, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Friction+measurements+on+contact+lenses+in+their+operating+environment.">Friction measurements on contact lenses in their operating environment.</a> Tribol Lett. 44, 387-397 (2011).</li><li>Sickenberger, W., Pult, H., Sickenberger, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=LIPCOF+and+contact+lens+wearers:+a+new+tool+to+forecast+subjective+dryness+and+degree+of+comfort+of+contact+lens+wearers.">LIPCOF and contact lens wearers: a new tool to forecast subjective dryness and degree of comfort of contact lens wearers.</a> Contactologia. 22, 74-79 (2000).</li><li>Pult, H., Purslow, C., Berry, M., Murphy, P. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Clinical+tests+for+successful+contact+lens+wear:+relationship+and+predictive+potential.">Clinical tests for successful contact lens wear: relationship and predictive potential.</a> Optom Vis Sci. 85, E924-E929 (2008).</li><li>Doughty, M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Morphological+features+of+cells+along+Marx's+line+of+the+marginal+conjunctiva+of+the+human+eyelid.">Morphological features of cells along Marx's line of the marginal conjunctiva of the human eyelid.</a> Clin Exp Optom. 96, 76-84 (2013).</li><li>Jalbert, I., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Assessing+the+human+lid+margin+epithelium+using+impression+cytology.">Assessing the human lid margin epithelium using impression cytology.</a> Acta Ophthalm. 90, e547-e552 (2012).</li><li>Nelson, J. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Impression+cytology.">Impression cytology.</a> Cornea. 7, 71-81 (1988).</li><li>Egbert, P. R., Lauber, S., Maurice, D. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+simple+conjunctival+biopsy.">A simple conjunctival biopsy.</a> Am J Ophthalmol. 84, 798-801 (1977).</li><li>Wilson, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Confocal microscopy. , 1-64 (1990).</li><li>Denk, W., Strickler, J. H., Webb, W. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Two-photon+laser+scanning+fluorescence+microscopy.">Two-photon laser scanning fluorescence microscopy.</a> Science. 248, 73-76 (1990).</li><li>Tomlins, P., Roy, P., Curnow, J., Rauz, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Assessment+of+the+EyePRIM+Device+for+Conjunctival+Impression+for+Flow+Cytometry.">Assessment of the EyePRIM Device for Conjunctival Impression for Flow Cytometry.</a> Invest Ophthalm Vis Sci. 54, 5430-5430 (2013).</li><li>Knop, E., Korb, D. R., Blackie, C. A., Knop, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+lid+margin+is+an+underestimated+structure+for+preservation+of+ocular+surface+health+and+development+of+dry+eye+disease.">The lid margin is an underestimated structure for preservation of ocular surface health and development of dry eye disease.</a> Res Proj Dry Eye Syn. 45, 108-122 (2010).</li><li>Knop, E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+lid+wiper+and+muco-cutaneous+junction+anatomy+of+the+human+eyelid+margins:+an+in+vivo+confocal+and+histological+study.">The lid wiper and muco-cutaneous junction anatomy of the human eyelid margins: an in vivo confocal and histological study.</a> J Anat. 218, 449-461 (2011).</li><li>Christensen, J. A., Skaarland, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nuclear+and+cell+area+measurements+in+the+cytological+evaluation+of+pleural+effusions:+a+study+of+subjective+assessments+and+morphometric+measurements.">Nuclear and cell area measurements in the cytological evaluation of pleural effusions: a study of subjective assessments and morphometric measurements.</a> Diag Cytopathol. 3, 50-54 (1987).</li></ol>

The authors have no relevant funding or conflicts to disclose.

Impression cytology is typically performed on the bulbar conjunctiva, using mixed cellulose ester membranes. Samples are cut to size from bulk material sheets, sterilized, applied and removed from the conjunctival surface using forceps. Using the same membrane material, a piston-controlled IC device was recently designed to match the surface geometry of the bulbar conjunctiva, and maintain consistent pressure between applications13. These approaches are inefficient for the narrow, prominently curved lid wiper ...

The human upper eyelid executes around 10,000 blinks every day1, with just a 1 - 2 mm narrow conjunctival region opposing the ocular globe. Due to its wiping motion during the blink, this portion of the lid margin has been termed the &#34;lid wiper&#34; region2. It is assumed that friction is increased in this region during habitual blinking, due to the lid wiping over the globe. This may play a significant role in ocular comfort. Contact lens wearers in particular experience ocular discomfort and this is one of the primary reasons for ceasing lens wear3. When a contact lens is placed on the eye, the friction coefficient between the lens material and the ocular surface has been shown to change4. There is evidence to suggest that dryness symptoms could be related to this altered friction2,5,6.
This association may also be reflected in clinically observable phenomena, notably lid wiper epitheliopathy (LWE), also called upper lid margin staining (ULMS)6. LWE is an early sign of ocular irritation and a potential predictor for dry eye disease. It is observed and measured by the vital staining of the upper and lower lid margin regions. While this grading system2 and its clinical validity (i.e., correlation with subjective symptoms) are still under debate, ocular discomfort remains a conundrum for clinicians and scientists alike and, most importantly, an inconvenience for patients.
To-date, little is known about clinically-relevant variations in the (sub-)cellular anatomy and physiology of the lid wiper area7 and only one report makes use of cytological methods8. Impression cytology (IC) has been employed for over 40 years to collect cells from the epithelial surface of the bulbar or tarsal conjunctiva by application of a membrane9,10. Upon removal, the adherent cells undergo cytological staining and microscopic imaging. Due to the anatomic and cellular differences in the lid wiper region, this technique requires optimization.

<table><tbody><tr><td>Alcian Blue, 1% in 3% Acetic Acid</td><td>Sigma</td><td>B8438-250ML</td><td></td></tr><tr><td>Hematoxylin, Gill 1</td><td>Sigma</td><td>GHS116-500ML</td><td></td></tr><tr><td>Papanicolaou stain, OG-6</td><td>Sigma</td><td>HT40116-500 ml</td><td></td></tr><tr><td>Papanicolaou stain, Modified EA</td><td>Sigma</td><td>HT40232-1L</td><td></td></tr><tr><td>Live/Dead Viability/Cytotoxicity Kit</td><td>Life Technologies</td><td>L-3224</td><td>contains ethidium homodimer-1 and Calcein AM dyes</td></tr><tr><td>Alcaine (0.5% proparacaine hydrochloride)</td><td>Alcon</td><td></td><td></td></tr><tr><td>Millicell Cell Culture Insert, 12&amp;nbsp;mm, hydrophilic PTFE, 0.4&amp;nbsp;&amp;micro;m</td><td>EMD Millipore</td><td>PICM01250&amp;nbsp;</td><td></td></tr><tr><td>35 mm Glass Bottom Dishes</td><td>MatTek Corporation</td><td>P35G-0-20-C</td><td></td></tr></tbody></table>

impression cytology of the lid wiper area

Few reports on the cellular anatomy of the lid wiper (LW) area of the inner eyelid exist and only one report makes use of cytological methods. The optimization of a method of collecting, staining and imaging cells from the LW region using impression cytology (IC) is described in this study. Cells are collected from the inner surface of the upper eyelid of human subjects using hydrophilic polytetrafluoroethylene (PTFE) membranes, and stained with cytological dyes to reveal the presence of goblet cells, mucins, cell nuclei and various degrees of pre- and para-keratinization. Immunocytochemical dyes show cell esterase activity and compromised cell membranes by the use of a confocal scanning laser microscope. Up to 100 microscopic digital images are captured for each sample and stitched into a high-resolution, large scale image of the entire IC span. We demonstrate a higher sensitivity of IC than reported before, appropriate for identifying cellular morphologies and metabolic activity in the LW area. To our knowledge, this is the first time this selection of fluorescent dyes was used to image LW IC membranes. This protocol will be effective in future studies to reveal undocumented details of the LW area, such as assessing cellular particularities of contact lens wearers or patients with dry eye or lid wiper epitheliopathy.

The cell culture membrane spanned over the plastic holder is a convenient tool for handheld collection of epithelial cells from the lid wiper conjunctiva. This method eliminates the need for additional sterilized instruments typically used to prepare and handle IC membranes. Figure 1 depicts the IC of the lid wiper area using a cell culture insert. We optimized two different staining protocols that complement each other to characterize epithelial cells from the lid wiper ...

Watch this Scientific Journal Video about Impression Cytology of the Lid Wiper Area at JoVE.com

Impression Cytology of the Lid Wiper Area

We collected, stained and imaged cells from the conjunctiva of the inner eyelid margin of human subjects. By characterizing cell morphology and metabolic activity, this method may further our understanding of dry eye and the role that friction between the ocular surfaces may play in perceiving ocular discomfort.

Few reports on the cellular anatomy of the lid wiper (LW) area of the inner eyelid exist and only one report makes use of cytological methods. The ...

impression-cytology-of-the-lid-wiper-area

Research

JoVE Journal

Medicine

10.4K Views.  University of Waterloo. We collected, stained and imaged cells from the conjunctiva of the inner eyelid margin of human subjects. By characterizing cell morphology and metabolic activity, this method may further our understanding of dry eye and the role that friction between the ocular surfaces may play in perceiving ocular discomfort. 

Video: Impression Cytology of the Lid Wiper Area

Automated Multiplex Immunofluorescence Panel for Immuno-oncology Studies on Formalin-fixed Carcinoma Tissue Specimens

Continued developments in immuno-oncology require an increased understanding of the mechanisms of cancer immunology. The immunoprofiling analysis of tissue samples from formalin-fixed, paraffin-embedded (FFPE) biopsies has become a key tool for understanding the complexity of tumor immunology and discovering novel predictive biomarkers for cancer immunotherapy. Immunoprofiling analysis of tissues requires the evaluation of combined markers, including inflammatory cell subpopulations and immune checkpoints, in the tumor microenvironment. The advent of novel multiplex immunohistochemical methods allows for a more efficient multiparametric analysis of single tissue sections than does standard monoplex immunohistochemistry (IHC). One commercially available multiplex immunofluorescence (IF) method is based on tyramide-signal amplification and, combined with multispectral microscopic analysis, allows for a better signal separation of diverse markers in tissue. This methodology is compatible with the use of unconjugated primary antibodies that have been optimized for standard IHC on FFPE tissue samples. Herein we describe in detail an automated protocol that allows multiplex IF labeling of carcinoma tissue samples with a six-marker multiplex antibody panel comprising PD-L1, PD-1, CD68, CD8, Ki-67, and AE1/AE3 cytokeratins with 4&#8242;,6-diamidino-2-phenylindole as a nuclear cell counterstain. The multiplex panel protocol is optimized in an automated IHC stainer for a staining time that is shorter than that of the manual protocol and can be directly applied and adapted by any laboratory investigator for immuno-oncology studies on human FFPE tissue samples. Also described are several controls and tools, including a drop-control method for fine quality control of a new multiplex IF panel, that are useful for the optimization and validation of the technique.

A detailed protocol for a six-marker multiplex immunofluorescence panel is optimized and performed, using an automated stainer for more consistent results and a shorter procedure time. This approach can be directly adapted by any laboratory for immuno-oncology studies.

Continued developments in immuno-oncology require an increased understanding of the mechanisms of cancer immunology. The immunoprofiling analysis of ...

Cancer Research

Live Imaging of the Ependymal Cilia in the Lateral Ventricles of the Mouse Brain

Multiciliated ependymal cells line the ventricles in the adult brain. Abnormal function or structure of ependymal cilia is associated with various neurological deficits. The current ex vivo live imaging of motile ependymal cilia technique allows for a detailed study of ciliary dynamics following several steps. These steps include: mice euthanasia with carbon dioxide according to protocols of The University of Toledo&#8217;s Institutional Animal Care and Use Committee (IACUC); craniectomy followed by brain removal and sagittal brain dissection with a vibratome or sharp blade to obtain very thin sections through the brain lateral ventricles, where the ependymal cilia can be visualized. Incubation of the brain&#8217;s slices in a customized glass-bottom plate containing Dulbecco&#8217;s Modified Eagle&#8217;s Medium (DMEM)/High-Glucose at 37 &#176;C in the presence of 95%/5% O2/CO2 mixture is essential to keep the tissue alive during the experiment. A video of the cilia beating is then recorded using a high-resolution differential interference contrast microscope. The video is then analyzed frame by frame to calculate the ciliary beating frequency. This allows distinct classification of the ependymal cells into three categories or types based on their ciliary beating frequency and angle. Furthermore, this technique allows the use of high-speed fluorescence imaging analysis to characterize the unique intracellular calcium oscillation properties of ependymal cells as well as the effect of pharmacological agents on the calcium oscillations and the ciliary beating frequency. In addition, this technique is suitable for immunofluorescence imaging for ciliary structure and ciliary protein localization studies. This is particularly important in disease diagnosis and phenotype studies. The main limitation of the technique is attributed to the decrease in live motile cilia movement as the brain tissue starts to die.

Using high-resolution differential interference contrast (DIC) microscopy, an ex vivo observation of the beating of motile ependymal cilia located within the mouse brain ventricles is demonstrated by live-imaging. The technique allows a recording of the unique ciliary beating frequency and beating angle as well as their intracellular calcium oscillation pacing properties.

Multiciliated ependymal cells line the ventricles in the adult brain. Abnormal function or structure of ependymal cilia is associated with various ...

Neuroscience

Observation of the Ciliary Movement of Choroid Plexus Epithelial Cells Ex Vivo

The choroid plexus is located in the ventricular wall of the brain, the main function of which is believed to be production of cerebrospinal fluid. Choroid plexus epithelial cells (CPECs) covering the surface of choroid plexus tissue harbor multiple unique cilia, but most of the functions of these cilia remain to be investigated. To uncover the function of CPEC cilia with particular reference to their motility, an ex vivo observation system was developed to monitor ciliary motility during embryonic, perinatal and postnatal periods. The choroid plexus was dissected out of the brain ventricle and observed under a video-enhanced contrast microscope equipped with differential interference contrast optics. Under this condition, a simple and quantitative method was developed to analyze the motile profiles of CPEC cilia for several hours ex vivo. Next, the morphological changes of cilia during development were observed by scanning electron microscopy to elucidate the relationship between the morphological maturity of cilia and motility. Interestingly, this method could delineate changes in the number and length of cilia, which peaked at postnatal day (P) 2, while the beating frequency reached a maximum at P10, followed by abrupt cessation at P14. These techniques will enable elucidation of the functions of cilia in various tissues. While related techniques have been published in a previous report1, the current study focuses on detailed techniques to observe the motility and morphology of CPEC cilia ex vivo.

Observation of the Ciliary Movement of Choroid Plexus Epithelial Cells Ex Vivo

In this study, a detailed light microscopic technique was optimized for real-time observation and analysis of the motion of CPEC cilia ex vivo together with an electron microscopic method for ultrastructural analysis.

The choroid plexus is located in the ventricular wall of the brain, the main function of which is believed to be production of cerebrospinal fluid. ...

Preparation and Morphological Analysis of Chick Cranial Neural Crest Cell Cultures

During vertebrate development, neural crest cells (NCCs) migrate extensively and differentiate into various cell types that contribute to structures like the craniofacial skeleton and the peripheral nervous system. While it is critical to understand NCC migration in the context of a 3D embryo, isolating migratory cells in 2D culture facilitates visualization and functional characterization, complementing embryonic studies. The present protocol demonstrates a method for isolating chick cranial neural folds to generate primary NCC cultures. Migratory NCCs emerge from neural fold explants plated onto a fibronectin-coated substrate. This results in dispersed, adherent NCC populations that can be assessed by staining and quantitative morphological analyses. This simplified culture approach is highly adaptable and can be combined with other techniques. For example, NCC emigration and migratory behaviors can be evaluated by time-lapse imaging or functionally queried by including inhibitors or experimental manipulations of gene expression (e.g., DNA, morpholino, or CRISPR electroporation). Because of its versatility, this method provides a powerful system for investigating cranial NCC development.

This versatile protocol describes the isolation of premigratory neural crest cells (NCCs) through the excision of cranial neural folds from chick embryos. Upon plating and incubation, migratory NCCs emerge from neural fold explants, allowing for assessment of cell morphology and migration in a simplified 2D environment.

During vertebrate development, neural crest cells (NCCs) migrate extensively and differentiate into various cell types that contribute to structures like ...

Developmental Biology

Evaluating Ocular Surface Squamous Neoplasia Using Anterior Segment HR-OCT

Anterior High-Resolution Optical Coherence Tomography in the Diagnosis and Therapeutic Monitoring of Ocular Surface Squamous Neoplasia

Ocular surface squamous neoplasia (OSSN) is the most common tumor of the ocular surface, ranging from mild dysplasia to invasive squamous carcinoma. Traditionally, the diagnosis of OSSN relies on histopathological confirmation followed by a full-thickness biopsy. However, in the past two decades, the therapeutic approach to OSSN has shifted from surgical intervention to topical chemotherapy regimens in clinical settings. This shift emphasizes the need for less invasive or non-invasive methods to diagnose ocular surface pathologies. Among various imaging devices, commercially available high-resolution optical coherence tomography (HR-OCT) has emerged as a powerful tool for the characterization of OSSN. HR-OCT provides an in vivo, cross-sectional view of ocular surface lesions, offering an "optical biopsy" for OSSN with high sensitivity and specificity. It provides valuable information in differentiating intraepithelial or invasive OSSN from other benign lesions. Additionally, HR-OCT can be used to monitor the response to topical chemotherapy and to detect subclinical OSSN during follow-up visits. In this article, the scanning protocol for image acquisition is presented, and image interpretation for OSSN is outlined. This standardized, practical, and reproducible approach is recommended in clinical workflows and is expected to assist clinicians in the management of OSSN.

Author Spotlight: Anterior HR-OCT as a Non-Invasive Tool for Characterizing Ocular Surface Squamous Neoplasia

Anterior segment high-resolution optical coherence tomography (HR-OCT) is a promising non-invasive modality for the diagnosis and therapeutic evaluation of ocular surface squamous neoplasia (OSSN). Here, the system setup, scanning technique, and representative diagnostic results are presented.

Ocular surface squamous neoplasia (OSSN) is the most common tumor of the ocular surface, ranging from mild dysplasia to invasive squamous carcinoma. ...

Engineering

A Non-invasive Way to Isolate and Phenotype Cells from the Conjunctiva

Traditionally, ocular surface cytology is studied with techniques such as spatula technology and brush technology. The problem with these techniques is that they may induce traumatic lesions on the surface of the eye, which can progress to scarring, eyelid deformity, limbal stem cell deficiency and in some cases, cause great discomfort to the subject. To avoid these clinical problems, impression cytology (IC) was developed to diagnose dry eye disease and later neoplasia, atopic disease, vernal keratoconjunctivitis and keratoconjunctivitis sicca. Typically, clinicians manually cut filter papers into required shapes and apply these to the ocular surface. Here, we describe how to perform IC using a commercially available medical device. This technique is explained here followed by immunophenotyping by flow cytometry. This technique requires less manual handling and causes less injury to the ocular surface.

The exposed normal ocular surface consists of cornea and conjunctiva. Epithelial cells, goblet cells and immune cells are present in the conjunctiva. Here, a non-invasive, technique of impression cytology is described using an impression cytology device and flow cytometry to analyze immune cells in the conjunctiva.

Traditionally, ocular surface cytology is studied with techniques such as spatula technology and brush technology. The problem with these techniques is ...

Immunology and Infection

Nasal Brushing Sampling and Processing Using Digital High Speed Ciliary Videomicroscopy &ndash; Adaptation for the COVID-19 Pandemic

Primary Ciliary Dyskinesia (PCD) is a genetic motile ciliopathy, leading to significant otosinopulmonary disease. PCD diagnosis is often missed or delayed due to challenges with different diagnostic modalities. Ciliary videomicroscopy, using Digital High-Speed Videomicroscopy (DHSV), one of the diagnostic tools for PCD, is considered the optimal method to perform ciliary functional analysis (CFA), comprising of ciliary beat frequency (CBF) and beat pattern (CBP) analysis. However, DHSV lacks standardized, published operating procedure for processing and analyzing samples. It also uses living respiratory epithelium, a significant infection control issue during the COVID-19 pandemic. To continue providing a diagnostic service during this health crisis, the ciliary videomicroscopy protocol has been adapted to include adequate infection control measures.
Here, we describe a revised protocol for sampling and laboratory processing of ciliated respiratory samples, highlighting adaptations made to comply with COVID-19 infection control measures. Representative results of CFA from nasal brushing samples obtained from 16 healthy subjects, processed and analyzed according to this protocol, are described. We also illustrate the importance of obtaining and processing optimal quality epithelial ciliated strips, as samples not meeting quality selection criteria do now allow for CFA, potentially decreasing the diagnostic reliability and the efficiency of this technique.

Nasal Brushing Sampling and Processing Using Digital High Speed Ciliary Videomicroscopy &#8211; Adaptation for the COVID-19 Pandemic

To guarantee a successful and high-quality ciliary functional analysis for PCD diagnosis, a precise and careful method for respiratory epithelium sampling and processing is essential. To continue providing PCD diagnostic service during the COVID-19 pandemic, the ciliary videomicroscopy protocol has been updated to include appropriate infection control measures.

Primary Ciliary Dyskinesia (PCD) is a genetic motile ciliopathy, leading to significant otosinopulmonary disease. PCD diagnosis is often missed or delayed ...

Optimized Protocol for Retinal Wholemount Preparation for Imaging and Immunohistochemistry

Working with delicate tissue can be a complicating factor when performing immunohistochemical assessment. Here, we present a method that utilizes a ring-supported hydrophilized PTFE membrane to provide structural support to both living and fixed tissue during immunohistochemical processing, which allows for the use of a variety of protocols that would otherwise cause damage to the tissue. First, this is demonstrated with bolus loading of fluorescent markers into living retinal tissue. This method allows for quick visualization of targeted structures, while the membrane support maintains tissue integrity during the injection and allows for easy transfer of the preparation for further imaging or processing.
Second, a procedure for antibody staining in tissue fixed with carbodiimide is described. Though paraformaldehyde fixation is more common, carbodiimide fixation provides a superior substrate for the visualization of synaptic proteins. A limitation of carbodiimide is that the resulting fixed tissue is relatively fragile; however, this is overcome with the use of the supporting membrane. Retinal tissue is used to demonstrate these techniques, but they may be applied to any fragile tissue.

The protocol described here is for structural assessment of a wholemount retinal preparation. This includes descriptions of tissue dissection, mounting onto a hydrophilized polytetrafluoroethylene (PTFE) membrane insert, bolus loading with fluorescent markers, and a comparison of fixation with carbodiimide and paraformaldehyde for immunohistochemical analysis of cellular and synaptic components.

Working with delicate tissue can be a complicating factor when performing immunohistochemical assessment. Here, we present a method that utilizes a ...

Biology

Induction of Ocular Surface Inflammation and Collection of Involved Tissues

Ocular surface diseases include a range of disorders that disturb the functions and structures of the cornea, conjunctiva, and the associated ocular surface gland network. Meibomian glands (MG) secrete lipids that create a covering layer that prevents the evaporation of the aqueous part of the tear film. Neutrophils and extracellular DNA traps populate MG and the ocular surface in a mouse model of allergic eye disease. Aggregated neutrophil extracellular traps (aggNETs) formulate a mesh-like matrix composed of extracellular chromatin that occludes MG outlets and conditions MG dysfunction. Here, a method for inducing ocular surface inflammation and MG dysfunction is presented. The procedures for collecting organs related to the ocular surface, such as the cornea, conjunctiva, and eyelids, are described in detail. Using established techniques for processing each organ, the major morphological and histopathological features of MG dysfunction are also shown. Ocular exudates offer the opportunity to assess the inflammatory state of the ocular surface. These procedures enable the investigation of topical and systemic anti-inflammatory interventions at the preclinical level.

Ocular surface inflammation harms the ocular surface tissues and compromises vital functions of the eye. The present protocol describes a method to induce ocular inflammation and collect compromised tissues in a mouse model of Meibomian gland dysfunction (MGD).

Ocular surface diseases include a range of disorders that disturb the functions and structures of the cornea, conjunctiva, and the associated ocular ...

An Epithelial Abrasion Model for Studying Corneal Wound Healing

The cornea is critical for vision, accounting for about two-thirds of the refractive power of the eye. Crucial to the role of the cornea in vision is its transparency. However, due to its external position, the cornea is highly susceptible to a wide variety of injuries that can lead to the loss of corneal transparency and eventual blindness. Efficient corneal wound healing in response to these injuries is pivotal for maintaining corneal homeostasis and preservation of corneal transparency and refractive capabilities. In events of compromised corneal wound healing, the cornea becomes vulnerable to infections, ulcerations, and scarring. Given the fundamental importance of corneal wound healing to the preservation of corneal transparency and vision, a better understanding of the normal corneal wound healing process is a prerequisite to understanding impaired corneal wound healing associated with infection and disease. Toward this goal, murine models of corneal wounding have proven useful in furthering our understanding of the corneal wound healing mechanisms operating under normal physiological conditions. Here, a protocol for creating a central corneal epithelial abrasion in mouse using a trephine and a blunt golf club spud is described. In this model, a 2 mm diameter circular trephine, centered over the cornea, is used to demarcate the wound area. The golf club spud is used with care to debride the epithelium and create a circular wound without damaging the corneal epithelial basement membrane. The resulting inflammatory response proceeds as a well-characterized cascade of cellular and molecular events that are critical for efficient wound healing. This simple corneal wound healing model is highly reproducible and well-published and is now being used to evaluate compromised corneal wound healing in the context of disease.

Here, a protocol for creating a central corneal epithelial abrasion wound in the mouse using a trephine and a blunt golf club spud is described. This corneal wound healing model is highly reproducible and is now being used to evaluate compromised corneal wound healing in the context of diseases.

The cornea is critical for vision, accounting for about two-thirds of the refractive power of the eye. Crucial to the role of the cornea in vision is its ...

Impression Cytology of the Lid Wiper Area

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