The authors would like to thank Mauna Kea Technologies for technical support. The authors also thank Shelly Hsiao for technical assistance and Kathleen E. Mach for critical review. This work was supported in part by NIH R01CA160986 to J.C.L.

1. Patient Preparation
<ol>
	<li>Consent patient scheduled for diagnostic cystoscopy and other endourological procedures such as transurethral resection of bladder tumor (TURBT) for CLE. Include in the consent a description of the use of intravesical and/or intravenous fluorescein as the contrast agent. Inquire history of hypersensitivity reaction to fluorescein.</li>
	<li>Patient is positioned for cystoscopy (typically in lithotomy position) and prepared in a sterile fashion.</li>
	<li>Proceed with standard white light cystoscopy (WLC) with a rigid or flexible cystoscope through the urethra.</li>
	<li>Survey all regions of the bladder under white light (Figure 1) and note regions of interest for CLE investigation.</li>
	<li>In addition to WLC, the bladder may be imaged with other macroscopic optical imaging modalities including fluorescence cystoscopy (Figure 2A) or narrow band imaging (Figure 2B) to identify additional areas of suspicion followed by characterization with CLE.</li>
	<li>Use a cautery electrode or resection loop to place a small cautery mark adjacent to the regions of interest that will both be imaged and biopsied for pathological confirmation. The cautery mark facilitates re-localization for subsequent CLE imaging and biopsy.</li>
</ol>
2. Contrast Agent
<ol>
	<li>Intravesical instillation of contrast agent
	<ol>
		<li>Prepare by diluting clinical grade 10% fluorescein sodium in sterile normal saline (0.9% NaCl) to desired concentration. For example, prepare 400 ml of 0.1% fluorescein by diluting 4 ml of 10% fluorescein in 396 ml of normal saline.</li>
		<li>Insert a sterile urinary catheter into the bladder and instill diluted contrast agent by gravity using a 60 ml catheter-tip syringe.</li>
		<li>Clamp the urinary catheter to hold contrast agent indwelling for 5 min.</li>
		<li>Drain contrast agent from bladder. Use the 60 ml catheter-tip syringe to wash out residual contrast from the bladder using normal saline, about 240-300 ml.</li>
		<li>Proceed to CLE imaging.</li>
	</ol>
	</li>
	<li>Intravenous injection of fluorescein
	<ol>
		<li>Draw 1.0 ml of fluorescein into syringe. Attach syringe to intravenous access and inject 0.5 - 1.0 ml of fluorescein intravenously as a bolus. Flush line with normal saline. This is typically done by the anesthesia team in the operating room.</li>
		<li>Proceed to CLE imaging.</li>
	</ol>
	</li>
</ol>
3. CLE Imaging
<ol>
	<li>Remove the sterilized CLE imaging probe (Cellvizio) from its packaging and connect it to the laser scanning unit (Mauna Kea Technologies, Paris, France)</li>
	<li>Warm up and calibrate the imaging probe by following the manufacturer's instructions.</li>
	<li>Re-insert the cystoscope or resectoscope into the bladder. Use a 0 degree lens with the rigid cystoscope.</li>
	<li>Advance the CLE imaging probe along the working channel of the cystoscope with the tip just beyond the cystoscope.</li>
	<li>Under white light, locate the previously marked regions of interest. Use additional normal saline irrigation as needed for visualization of the mucosa and maintain moderate distension of the bladder.</li>
	<li>Manipulate CLE imaging probe with the operator's hand for direct en face contact of the regions of interest. For optical sectioning of the regions of interest, gently increase and decrease pressure to the imaging probe while maintaining direct contact.
	<ol>
		<li>To reach tumors located at the anterior bladder, a standard Albarran bridge may help facilitate deflection of the imaging probe for direct contact with the region of interest (Figure 2C).</li>
	</ol>
	</li>
	<li>Common regions of interest include papillary tumor, non-papillary tumor, transition between normal-appearing mucosa and tumor, and erythematous patches, which can all be imaged using either intravesical or intravenous fluorescein administration. Intravenous fluorescein is required for imaging of the resection bed, prostatic urethra, and penile urethra.</li>
	<li>As the imaging probe scans region of interest, record images for future analysis. Note overall cellular morphology, boundary, organization, and presence of neo-angiogenesis.</li>
	<li>Upon completion of imaging, remove CLE imaging probe from working channel.</li>
	<li>If desired, obtain cold-cup biopsies from corresponding regions of interest that were scanned by CLE. Use cautery markings as landmarks for co-registration of the imaged areas that are biopsied.</li>
	<li>Complete TURBT per routine. In patients who received intravenous fluorescein, consider using continuous flow resectoscopes to improve visualization during resection, as fluorescein is excreted by the kidney into the bladder approximately 5 min after intravenous administration.</li>
	<li>Retrieve saved image recordings from confocal processor and conduct image analysis.</li>
</ol>

<ol>
	<li>Thiberville, L., 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=Human+in+vivo+fluorescence+microimaging+of+the+alveolar+ducts+and+sacs+during+bronchoscopy.">Human in vivo fluorescence microimaging of the alveolar ducts and sacs during bronchoscopy.</a> Eur. Respir. J. 33, 974-985 (2009).</li><li>Dunbar, K. B., Okolo, P., Montgomery, E., Canto, M. I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Confocal+laser+endomicroscopy+in+Barrett's+esophagus+and+endoscopically+inapparent+Barrett's+neoplasia:+a+prospective,+randomized,+double-blind,+controlled,+crossover+trial.">Confocal laser endomicroscopy in Barrett's esophagus and endoscopically inapparent Barrett's neoplasia: a prospective, randomized, double-blind, controlled, crossover trial.</a> Gastrointest. Endosc. 70, 645-654 (2009).</li><li>Buchner, A. M., 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=Comparison+of+probe-based+confocal+laser+endomicroscopy+with+virtual+chromoendoscopy+for+classification+of+colon+polyps.">Comparison of probe-based confocal laser endomicroscopy with virtual chromoendoscopy for classification of colon polyps.</a> Gastroenterology. 138, 834-842 (2010).</li><li>Pech, O., 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=Confocal+laser+endomicroscopy+for+in+vivo+diagnosis+of+early+squamous+cell+carcinoma+in+the+esophagus.">Confocal laser endomicroscopy for in vivo diagnosis of early squamous cell carcinoma in the esophagus.</a> Clin. Gastroenterol. Hepatol. 6, 89-94 (2008).</li><li>Goetz, M., 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=In+vivo+confocal+laser+endo+microscopy+of+the+human+liver:+a+novel+method+for+assessing+liver+microarchitecture+in+real+time.">In vivo confocal laser endo microscopy of the human liver: a novel method for assessing liver microarchitecture in real time.</a> Endoscopy. 40, 554-562 (2008).</li><li>Meining, A., 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=Detection+of+cholangiocarcinoma+in+vivo+using+miniprobe-based+confocal+fluorescence+microscopy.">Detection of cholangiocarcinoma in vivo using miniprobe-based confocal fluorescence microscopy.</a> Clin. Gastroenterol. Hepatol. 6, 1057-1060 (2008).</li><li>Wu, K., 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=Dynamic+real-time+microscopy+of+the+urinary+tract+using+confocal+laser+endomicroscopy.">Dynamic real-time microscopy of the urinary tract using confocal laser endomicroscopy.</a> Urology. 78, 225-231 (2011).</li><li>Sonn, G. A., 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=Optical+biopsy+of+human+bladder+neoplasia+with+in+vivo+confocal+laser+endomicroscopy.">Optical biopsy of human bladder neoplasia with in vivo confocal laser endomicroscopy.</a> J. Urol. 182, 1299-1305 (2009).</li><li>Sonn, G. A., 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=Fibered+confocal+microscopy+of+bladder+tumors:+an+ex+vivo+study.">Fibered confocal microscopy of bladder tumors: an ex vivo study.</a> J. Endourol. 23, 197-201 (2009).</li><li>Adams, W., 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=Comparison+of+2.6-+and+1.4-mm+imaging+probes+for+confocal+laser+endomicroscopy+of+the+urinary+tract.">Comparison of 2.6- and 1.4-mm imaging probes for confocal laser endomicroscopy of the urinary tract.</a> J. Endourol. 25, 917-921 (2011).</li><li>Wiesner, C., 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=Confocal+laser+endomicroscopy+for+the+diagnosis+of+urothelial+bladder+neoplasia:+a+technology+of+the+future?.">Confocal laser endomicroscopy for the diagnosis of urothelial bladder neoplasia: a technology of the future?.</a> BJU Int. 107, 399-403 (2011).</li><li>Wallace, M. B., 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+safety+of+intravenous+fluorescein+for+confocal+laser+endomicroscopy+in+the+gastrointestinal+tract.">The safety of intravenous fluorescein for confocal laser endomicroscopy in the gastrointestinal tract.</a> Aliment. Pharmacol. Ther. 31, 548-552 (2010).</li><li>Konda, V. J. A., 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=First+assessment+of+needle-based+confocal+laser+endomicroscopy+during+EUS-FNA+procedures+of+the+pancreas+(with+videos.">First assessment of needle-based confocal laser endomicroscopy during EUS-FNA procedures of the pancreas (with videos.</a> Gastrointest. Endosc. 74, 1049-1060 (2011).</li><li>Liu, J. -. J., Droller, M., Liao, J. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=New+Optical+Imaging+Technologies+in+Bladder+Cancer:+Considerations+and+Perspectives.">New Optical Imaging Technologies in Bladder Cancer: Considerations and Perspectives.</a> J. Urol. 188, 361-368 (2012).</li><li>Hsiung, P. -. L., 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=Detection+of+colonic+dysplasia+in+vivo+using+a+targeted+heptapeptide+and+confocal+microendoscopy.">Detection of colonic dysplasia in vivo using a targeted heptapeptide and confocal microendoscopy.</a> Nat. Med. 14, 454-458 (2008).</li></ol>

No conflicts of interest declared.

Attaining and maintaining solid en face contact between the imaging probe and the bladder mucosa is the most critical step in acquiring optimal image quality. There is approximately a 3-5 patient learning curve to develop the dexterity to manipulate the imaging probe and to hold the probe steady during image acquisition. Additionally, as this procedure is conducted in vivo, patient movements (i.e. respiratory) and vascular pulsations may affect the imaging probe contact with the bladder....

<table border="1">
 <tbody>
 <tr>
 <td>Name of the reagent</td>
 <td>Company</td>
 <td>Catalogue number</td>
 <td>Comments (optional)</td>
 </tr>
 <tr>
 <td>Cellvizio 100 Series</td>
 <td>Mauna Kea Technologies</td>
 <td>100 Series</td>
 <td>Includes confocal processor and LSU: F400-v2 at 488 nm</td>
 </tr>
 <tr>
 <td>Cellvizio Confocal Miniprobe</td>
 <td>Mauna Kea Technologies</td>
 <td>Gastroflex UHD </td>
 <td></td>
 </tr>
 <tr>
 <td>AK-FLUOR 10%</td>
 <td>Akorn, Inc.</td>
 <td>NDC 17478-253-10 </td>
 <td></td>
 </tr>
 </tbody>
</table>

probe-based confocal laser endomicroscopy of the urinary tract: the technique

Probe-based confocal laser endomicroscopy (CLE) is an emerging optical imaging technology that enables real-time in vivo microscopy of mucosal surfaces during standard endoscopy. With applications currently in the respiratory1 and gastrointestinal tracts,2-6 CLE has also been explored in the urinary tract for bladder cancer diagnosis.7-10 Cellular morphology and tissue microarchitecture can be resolved with micron scale resolution in real time, in addition to dynamic imaging of the normal and pathological vasculature.7
The probe-based CLE system (Cellvizio, Mauna Kea Technologies, France) consists of a reusable fiberoptic imaging probe coupled to a 488 nm laser scanning unit. The imaging probe is inserted in the working channels of standard flexible and rigid endoscopes. An endoscope-based CLE system (Optiscan, Australia), in which the confocal endomicroscopy functionality is integrated onto the endoscope, is also used in the gastrointestinal tract. Given the larger scope diameter, however, application in the urinary tract is currently limited to ex vivo use.11 Confocal image acquisition is done through direct contact of the imaging probe with the target tissue and recorded as video sequences. As in the gastrointestinal tract, endomicroscopy of the urinary tract requires an exogenenous contrast agent&mdash;most commonly fluorescein, which can be administered intravenously or intravesically. Intravesical administration is a well-established method to introduce pharmacological agents locally with minimal systemic toxicity that is unique to the urinary tract. Fluorescein rapidly stains the extracellular matrix and has an established safety profile.12 Imaging probes of various diameters enable compatibility with different caliber endoscopes. To date, 1.4 and 2.6 mm probes have been evaluated with flexible and rigid cystoscopy.10 Recent availability of a &lt; 1 mm imaging probe13 opens up the possibility of CLE in the upper urinary tract during ureteroscopy. Fluorescence cystoscopy (i.e. photodynamic diagnosis) and narrow band imaging are additional endoscope-based optical imaging modalities14 that can be combined with CLE to achieve multimodal imaging of the urinary tract. In the future, CLE may be coupled with molecular contrast agents such as fluorescently labeled peptides15 and antibodies for endoscopic imaging of disease processes with molecular specificity.

CLE images are saved as grayscale video sequence files at 12 frames per second. Image interpretation is done in real time and may be used to impact clinical decision making under an investigational protocol. Offline analysis, which includes reviewing of the video sequence, additional image processing such as mosaicing,7 and comparison with standard pathology, are important during the learning curve phase associated with the technology. Figures 1B and 1C are representative CLE images obtained from two different...

Watch this Scientific Journal Video about Probe-based Confocal Laser Endomicroscopy of the Urinary Tract: The Technique at JoVE.com

Probe-based Confocal Laser Endomicroscopy of the Urinary Tract: The Technique

Probe-based confocal laser endomicroscopy enables real-time microscopy of the human urinary tract during cystoscopy, providing dynamic, intravital imaging of pathological states such as bladder cancer with cellular resolution. Endomicroscopy may augment the diagnostic accuracy of standard white light endoscopy and provide intraoperative image guidance to improve surgical resection.

Probe-based  confocal laser endomicroscopy (CLE) is an emerging optical imaging technology  that enables real-time in vivo microscopy of mucosal surfaces ...

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20.7K Views.  Stanford University School of Medicine. Probe-based confocal laser endomicroscopy enables real-time microscopy of the human urinary tract during cystoscopy, providing dynamic, intravital imaging of pathological states such as bladder cancer with cellular resolution. Endomicroscopy may augment the diagnostic accuracy of standard white light endoscopy and provide intraoperative image guidance to improve surgical resection.

Video: Probe-based Confocal Laser Endomicroscopy of the Urinary Tract: The Technique

Oral Biofilm Analysis of Palatal Expanders by Fluorescence In-Situ Hybridization and Confocal Laser Scanning Microscopy

Confocal laser scanning microscopy (CLSM) of natural heterogeneous biofilm is today facilitated by a comprehensive range of staining techniques, one of them being fluorescence in situ hybridization (FISH).1,2 We performed a pilot study in which oral biofilm samples collected from fixed orthodontic appliances (palatal expanders) were stained by FISH, the objective being to assess the three-dimensional organization of natural biofilm and plaque accumulation.3,4 FISH creates an opportunity to stain cells in their native biofilm environment by the use of fluorescently labeled 16S rRNA-targeting probes.4-7,19 Compared to alternative techniques like immunofluorescent labeling, this is an inexpensive, precise and straightforward labeling technique to investigate different bacterial groups in mixed biofilm consortia.18,20 General probes were used that bind to Eubacteria (EUB338 + EUB338II + EUB338III; hereafter EUBmix),8-10 Firmicutes (LGC354 A-C; hereafter LGCmix),9,10 and Bacteroidetes (Bac303).11 In addition, specific probes binding to Streptococcus mutans (MUT590)12,13 and Porphyromonas gingivalis (POGI)13,14 were used. The extreme hardness of the surface materials involved (stainless steel and acrylic resin) compelled us to find new ways of preparing the biofilm. As these surface materials could not be readily cut with a cryotome, various sampling methods were explored to obtain intact oral biofilm. The most workable of these approaches is presented in this communication. Small flakes of the biofilm-carrying acrylic resin were scraped off with a sterile scalpel, taking care not to damage the biofilm structure. Forceps were used to collect biofilm from the steel surfaces. Once collected, the samples were fixed and placed directly on polysine coated glass slides. FISH was performed directly on these slides with the probes mentioned above. Various FISH protocols were combined and modified to create a new protocol that was easy to handle.5,10,14,15 Subsequently the samples were analyzed by confocal laser scanning microscopy. Well-known configurations3,4,16,17 could be visualized, including mushroom-style formations and clusters of coccoid bacteria pervaded by channels. In addition, the bacterial composition of these typical biofilm structures were analyzed and 2D and 3D images created.

We present a protocol for structural and compositional analysis of natural oral biofilm from orthodontic appliances with in situ hybridization (FISH) and confocal laser scanning microscopy (CLSM). Oral biofilm samples were collected from palatal expanders, scraping acrylic-resin flakes off their surface and referring them for molecular processing.

Confocal laser scanning microscopy (CLSM) of natural heterogeneous biofilm is today facilitated by a comprehensive range of staining techniques, one of ...

Bladder Smooth Muscle Strip Contractility as a Method to Evaluate Lower Urinary Tract Pharmacology

We describe an in vitro method to measure bladder smooth muscle contractility, and its use for investigating physiological and pharmacological properties of the smooth muscle as well as changes induced by pathology. This method provides critical information for understanding bladder function while overcoming major methodological difficulties encountered in in vivo experiments, such as surgical and pharmacological manipulations that affect stability and survival of the preparations, the use of human tissue, and/or the use of expensive chemicals. It also provides a way to investigate the properties of each bladder component (i.e. smooth muscle, mucosa, nerves) in healthy and pathological conditions.
The urinary bladder is removed from an anesthetized animal, placed in Krebs solution and cut into strips. Strips are placed into a chamber filled with warm Krebs solution. One end is attached to an isometric tension transducer to measure contraction force, the other end is attached to a fixed rod. Tissue is stimulated by directly adding compounds to the bath or by electric field stimulation electrodes that activate nerves, similar to triggering bladder contractions in vivo. We demonstrate the use of this method to evaluate spontaneous smooth muscle contractility during development and after an experimental spinal cord injury, the nature of neurotransmission (transmitters and receptors involved), factors involved in modulation of smooth muscle activity, the role of individual bladder components, and species and organ differences in response to pharmacological agents. Additionally, it could be used for investigating intracellular pathways involved in contraction and/or relaxation of the smooth muscle, drug structure-activity relationships and evaluation of transmitter release.
The in vitro smooth muscle contractility method has been used extensively for over 50 years, and has provided data that significantly contributed to our understanding of bladder function as well as to pharmaceutical development of compounds currently used clinically for bladder management.

This manuscript presents a simple, yet powerful, in vitro method for evaluating smooth muscle contractility in response to pharmacological agents or nerve stimulation. Main applications are drug screening and understanding tissue physiology, pharmacology,&#160;and pathology.

We describe an in vitro method to measure bladder smooth muscle contractility, and its use for investigating physiological and pharmacological properties ...

Rose Bengal Photothrombosis by Confocal Optical Imaging In Vivo: A Model of Single Vessel Stroke

In vivo imaging techniques have increased in utilization due to recent advances in imaging dyes and optical technologies, allowing for the ability to image cellular events in an intact animal. Additionally, the ability to induce physiological disease states such as stroke in vivo increases its utility. The technique described herein allows for physiological assessment of cellular responses within the CNS following a stroke and can be adapted for other pathological conditions being studied. The technique presented uses laser excitation of the photosensitive dye Rose Bengal in vivo to induce a focal ischemic event in a single blood vessel. 
The video protocol demonstrates the preparation of a thin-skulled cranial window over the somatosensory cortex in a mouse for the induction of a Rose Bengal photothrombotic event keeping injury to the underlying dura matter and brain at a minimum. Surgical preparation is initially performed under a dissecting microscope with a custom-made surgical/imaging platform, which is then transferred to a confocal microscope equipped with an inverted objective adaptor. Representative images acquired utilizing this protocol are presented as well as time-lapse sequences of stroke induction. This technique is powerful in that the same area can be imaged repeatedly on subsequent days facilitating longitudinal in vivo studies of pathological processes following stroke.

Rose Bengal Photothrombosis by Confocal Optical Imaging In Vivo:  A Model of Single Vessel Stroke

Here, we describe a semi-invasive optical microscopy approach for the induction of a Rose Bengal photothrombotic clot in the somatosensory cortex of a mouse in vivo. The technical aspects of the imaging procedure are described from induction of a photothrombotic event to application and data collection.

In vivo imaging techniques have increased in utilization due to recent advances in imaging dyes and optical technologies, allowing for the ability to ...

Using a Laminating Technique to Perform Confocal Microscopy of the Human Sclera

The sclera is a dense connective tissue that covers and protects the eye. It mainly consists of dense collagen bundles (types I, III, IV, V, VI, and VII). Due to its autofluorescence, opaqueness, and thickness, it has not been found suitable for confocal microscopy. An alternative approach to the one presented here, which uses formalin-fixed sclera embedded in paraffin for immunohistochemistry, has technical challenges, especially when preheating the tissue for antigen retrieval. Since the sclera is relatively poor in both cells and vessels, the use of larger tissue samples was explored to help prevent overlooking cells and to understand their localization in relation to vessels and other anatomical sites. To allow for the analysis of larger tissue samples under the confocal microscope, a laminating technique was performed to create thin layers from the sclera. Following the analysis of results of CD31 blood vessels and lymphatic vessel endothelial hyaluronan receptor 1 (LYVE1) positive cells, for which approval for scientific examination was obtained, the advantages and limitations of this method are discussed.

Human sclera tissue is mainly collagen; therefore, it is not easily usable for immunohistochemistry. To achieve the goal of performing immunohistochemistry for confocal microscopy of scleral tissue, a laminating technique was used.


The sclera is a dense connective tissue that covers and protects the eye. It mainly consists of dense collagen bundles (types I, III, IV, V, VI, and ...

Imaging Metals in Brain Tissue by Laser Ablation - Inductively Coupled Plasma - Mass Spectrometry (LA-ICP-MS)

Metals are found ubiquitously throughout an organism, with their biological role dictated by both their chemical reactivity and abundance within a specific anatomical region. Within the brain, metals have a highly compartmentalized distribution, depending on the primary function they play within the central nervous system. Imaging the spatial distribution of metals has provided unique insight into the biochemical architecture of the brain, allowing direct correlation between neuroanatomical regions and their known function with regard to metal-dependent processes. In addition, several age-related neurological disorders feature disrupted metal homeostasis, which is often confined to small regions of the brain that are otherwise difficult to analyze. Here, we describe a comprehensive method for quantitatively imaging metals in the mouse brain, using laser ablation - inductively coupled plasma - mass spectrometry (LA-ICP-MS) and specially designed image processing software. Focusing on iron, copper and zinc, which are three of the most abundant and disease-relevant metals within the brain, we describe the essential steps in sample preparation, analysis, quantitative measurements and image processing to produce maps of metal distribution within the low micrometer resolution range. This technique, applicable to any cut tissue section, is capable of demonstrating the highly variable distribution of metals within an organ or system, and can be used to identify changes in metal homeostasis and absolute levels within fine anatomical structures.

Imaging Metals in Brain Tissue by Laser Ablation - Inductively Coupled Plasma - Mass Spectrometry LA-ICP-MS

Quantitatively mapping metals in tissue by laser ablation - inductively coupled plasma - mass spectrometry (LA-ICP-MS) is a sensitive analytical technique that can provide new insight into how metals participate in normal function and disease processes. Here, we describe a protocol for quantitatively imaging metals in thin sections of mouse neurological tissue.

Metals are found ubiquitously throughout an organism, with their biological role dictated by both their chemical reactivity and abundance within a ...

Spatial Quantification of Drugs in Pulmonary Tuberculosis Lesions by Laser Capture Microdissection Liquid Chromatography Mass Spectrometry (LCM-LC/MS)

Tuberculosis is still a leading cause of morbidity and mortality worldwide. Improvements to existing drug regimens and the development of novel therapeutics are urgently required. The ability of dosed TB drugs to reach and sterilize bacteria within poorly-vascularized necrotic regions (caseum) of pulmonary granulomas is crucial for successful therapeutic intervention. Effective therapeutic regimens must therefore contain drugs with favorable caseum penetration properties. Current LC/MS methods for quantifying drug levels in biological tissues have limited spatial resolution capabilities, making it difficult to accurately determine absolute drug concentrations within small tissue compartments such as those found within necrotic granulomas. Here we present a protocol combining laser capture microdissection (LCM) of pathologically-distinct tissue regions with LC/MS quantification. This technique provides absolute quantification of drugs within granuloma caseum, surrounding cellular lesion and uninvolved lung tissue and, therefore, accurately determines whether bactericidal concentrations are being achieved. In addition to tuberculosis research, the technique has many potential applications for spatially-resolved quantification of drugs in diseased tissues.

Spatial Quantification of Drugs in Pulmonary Tuberculosis Lesions by Laser Capture Microdissection Liquid Chromatography Mass Spectrometry LCM-LC/MS

Here, we describe a protocol using laser capture microdissection coupled with LC/MS analysis to spatially-quantify drug distributions within pulmonary tuberculosis granulomas. The approach has broad applicability to quantifying drug concentrations within tissues at high spatial detail.

Tuberculosis is still a leading cause of morbidity and mortality worldwide. Improvements to existing drug regimens and the development of novel ...

Ultrasonography of the Adult Male Urinary Tract for Urinary Functional Testing

The incidence of clinical benign prostatic hyperplasia (BPH) and lower urinary tract symptoms (LUTS) is increasing due to the aging population, resulting in a significant economic and quality of life burden. Transgenic and other mouse models have been developed to recreate various aspects of this multifactorial disease; however, methods to accurately quantitate urinary dysfunction and the effectiveness of new therapeutic options are lacking. Here, we describe a method that can be used to measure bladder volume and detrusor wall thickness, urinary velocity, void volume and void duration, and urethral diameter. This would allow for the evaluation of disease progression and treatment efficacy over time. Mice were anesthetized with isoflurane, and the bladder was visualized by ultrasound. For non-contrast imaging, a 3D image was taken of the bladder to calculate volume and evaluate shape; the bladder wall thickness was measured from this image. For contrast-enhanced imaging, a catheter was placed through the dome of the bladder using a 27-gauge needle connected to a syringe by PE50 tubing. A bolus of 0.5 mL of contrast was infused into the bladder until a urination event occurred. Urethral diameter was determined at the point of the Doppler velocity sample window during the first voiding event. Velocity was measured for each subsequent event yielding a flow rate. In conclusion, high frequency ultrasound proved to be an effective method for assessing bladder and urethral measurements during urinary function in mice. This technique may be useful in the assessment of novel therapies for BPH/LUTS in an experimental setting.

We describe the use of high frequency ultrasound with contrast imaging as a method to measure bladder volume, bladder wall thickness, urine velocity, void volume, void duration, and urethral diameter. This strategy can be used to assess voiding dysfunction and treatment efficacy in various mouse models of lower urinary tract dysfunction (LUTD).

The incidence of clinical benign prostatic hyperplasia (BPH) and lower urinary tract symptoms (LUTS) is increasing due to the aging population, resulting ...

Technical Modification of the Terminal Ureter During Total Transperitoneal Laparoscopic Nephroureterectomy for Upper Urinary Tract Urothelial Carcinoma

Upper tract urothelial carcinoma (UTUC) accounts for 5%&ndash;10% of all urothelial tumors. Radical nephroureterectomy is the standard treatment procedure. At present, different choices still exist for treating the ureteral end during laparoscopic ureteral bladder sleeve resection. Our center has adopted a new method for treating the ureteral end. This new method can increase the operating space and reduce the difficulty of the surgery compared with current methods.

Here, we present a protocol to increase the surgical field of view and reduce the difficulty of total transperitoneal laparoscopic nephroureterectomy surgery by precutting the umbilical ligament before treating the terminal ureter.

Upper tract urothelial carcinoma (UTUC) accounts for 5%&ndash;10% of all urothelial tumors. Radical nephroureterectomy is the standard treatment ...

Laser Doppler Perfusion Imaging in the Mouse Hindlimb

Blood flow recovery is a critical outcome measure after experimental hindlimb ischemia or ischemia-reperfusion. Laser Doppler perfusion imaging (LDPI) is a common, noninvasive, repeatable method for assessing blood flow recovery. The technique calculates overall blood flow in the sampled tissue from the Doppler shift in frequency caused when a laser hits moving red blood cells. Measurements are expressed in arbitrary perfusion units, so the contralateral non-intervened upon leg is usually used to help control measurements. Measurement depth is in the range of 0.3-1 mm; for hindlimb ischemia, this means that dermal perfusion is assessed. Dermal perfusion is dependent on several factors&#8212;most importantly skin temperature and anesthetic agent, which must be carefully controlled to result in reliable readings. Furthermore, hair and skin pigmentation can alter the ability of the laser to either reach or penetrate to the dermis. This article demonstrates the technique of LDPI in the mouse hindlimb.

Here, we present a protocol that demonstrates the technique and necessary controls for Laser Doppler perfusion imaging to measure blood flow in the mouse hindlimb.

Blood flow recovery is a critical outcome measure after experimental hindlimb ischemia or ischemia-reperfusion. Laser Doppler perfusion imaging (LDPI) is ...

Characterization of a Novel Human Organotypic Retinal Culture Technique

Previous human organotypic retinal culture (HORC) models have utilized detached retinas; however, without the structural support conferred by retinal pigment epithelium-choroid (RPE-choroid) and sclera, the integrity of the fragile retina can easily be compromised. The aim of this study was to develop a novel HORC model that contains the retina, RPE-choroid and sclera to maintain retinal integrity when culturing retinal explants.
After cutting circumferentially along the limbus to remove iris and lens, four deep incisions were made to flatten the eyecup. In contrast to previous HORC protocols, a trephine was used to cut through not only the retina but also the RPE-choroid and sclera. The resultant triple-layered explants were cultured for 72 h. Hematoxylin and Eosin staining (H&#38;E) was used to assess anatomical structures and retinal explants were further characterized by immunohistochemistry (IHC) for apoptosis, M&#252;ller cell integrity and retinal inflammation. To confirm the possibility of disease induction, explants were exposed to high glucose (HG) and pro-inflammatory cytokines (Cyt), to mimic diabetic retinopathy (DR). The Luminex magnetic bead assay was used to measure DR-related cytokines released into the culture medium.
H&#38;E staining revealed distinct retinal lamellae and compact nuclei in retinal explants with the underlying RPE-choroid and sclera, while retinas without the underlying structures exhibited reduced thickness and severe nuclei loss. IHC results indicated absence of apoptosis and retinal inflammation as well as preserved M&#252;ller cell integrity. The Luminex&#160;assays showed significantly increased secretion of DR-associated pro-inflammatory cytokines in retinal explants exposed to HG + Cyt relative to baseline levels at 24 h.
We successfully developed and characterized a novel HORC protocol in which retinal integrity was preserved without apoptosis or retinal inflammation. Moreover, the induced secretion of DR-associated pro-inflammatory biomarkers when exposing retinal explants to HG + Cyt suggests that this model could be used for clinically translatable retinal disease studies.

This study aims to develop a novel human organotypic retinal culture (HORC) model that prevents compromising retinal integrity during explant handling. This is achieved by culturing the retina with the overlying vitreous and the underlying retinal pigment&#160;epithelium-choroid (RPE-choroid) and sclera.

Previous human organotypic retinal culture (HORC) models have utilized detached retinas; however, without the structural support conferred by retinal ...