Protocol for intraoperative assessment of the human cerebrovascular glycocalyx

INTRODUCTION

Adequate functioning of the blood-brain barrier (BBB) is important for brain homoeostasis and normal neuronal function. Disruption of the BBB has been described in several neurological diseases. Recent reports suggest that an increased permeability of the BBB also contributes to increased seizure susceptibility in patients with epilepsy. The endothelial glycocalyx is coating the luminal side of the endothelium and can be considered as the first barrier of the BBB. We hypothesise that an altered glycocalyx thickness plays a role in the aetiology of temporal lobe epilepsy (TLE), the most common type of epilepsy. Here, we propose a protocol that allows intraoperative assessment of the cerebrovascular glycocalyx thickness in patients with TLE and assess whether its thickness is decreased in patients with TLE when compared with controls.

METHODS AND ANALYSIS

This protocol is designed as a prospective observational case-control study in patients who undergo resective brain surgery as treatment for TLE. Control subjects are patients without a history of epileptic seizures, who undergo a craniotomy or burr hole surgery for other indications. Intraoperative glycocalyx thickness measurements of sublingual, cortical and hippocampal microcirculation are performed by video microscopy using sidestream dark-field imaging. Demographic details, seizure characteristics, epilepsy risk factors, intraoperative haemodynamic parameters and histopathological evaluation are additionally recorded.

ETHICS AND DISSEMINATION

This protocol has been ethically approved by the local medical ethical committee (ID: NL51594.068.14) and complies with the Declaration of Helsinki and principles of Good Clinical Practice. Informed consent is obtained before study enrolment and only coded data will be stored in a secured database, enabling an audit trail. Results will be submitted to international peer-reviewed journals and presented at international conferences.

TRIAL REGISTRATION NUMBER

NTR5568.

Development of single-channel optical video stereomicroscopy

This study introduces a single-channel optical video stereomicroscope based on a transparent rotating deflector (TRD) for high-resolution and high-magnification stereomicroscopy. The existing stereomicroscopes have some limitations, such as limited resolution and magnification, fixed optical channel, and the necessity to use higher quality and higher cost optical channel components compared with the conventional optical microscopes. The goal of this study was to develop a method for improved stereo imaging and stereovision for optical microscopy. Here, we demonstrate the generation of stereo video images of left and right pairs by the refraction of light passing through a motorized TRD. We estimated the corresponding rotation angles for human stereovision and the required torque. In addition, we evaluated the image quality stability under the TRD rotation.

Changes in dynamic embryonic heart wall motion in response to outflow tract banding measured using video densitometry

Abnormal blood flow during early cardiovascular development has been identified as a key factor in the pathogenesis of congenital heart disease; however, the mechanisms by which altered hemodynamics induce cardiac malformations are poorly understood. This study used outflow tract (OFT) banding to model increased afterload, pressure, and blood flow velocities at tubular stages of heart development and characterized the immediate changes in cardiac wall motion due to banding in chicken embryo models with light microscopy-based video densitometry. Optical videos were used to acquire two-dimensional heart image sequences over the cardiac cycle, from which intensity data were extracted along the heart centerline at several locations in the heart ventricle and OFT. While no changes were observed in the synchronous contraction of the ventricle with banding, the peristaltic-like wall motion in the OFT was significantly affected. Our data provide valuable insight into early cardiac biomechanics and its characterization using a simple light microscopy-based imaging modality.

A wireless centrifuge force microscope (CFM) enables multiplexed single-molecule experiments in a commercial centrifuge

The centrifuge force microscope (CFM) was recently introduced as a platform for massively parallel single-molecule manipulation and analysis. Here we developed a low-cost and self-contained CFM module that works directly within a commercial centrifuge, greatly improving accessibility and ease of use. Our instrument incorporates research grade video microscopy, a power source, a computer, and wireless transmission capability to simultaneously monitor many individually tethered microspheres. We validated the instrument by performing single-molecule force shearing of short DNA duplexes. For a 7 bp duplex, we observed over 1000 dissociation events due to force dependent shearing from 2 pN to 12 pN with dissociation times in the range of 10-100 s. We extended the measurement to a 10 bp duplex, applying a 12 pN force clamp and directly observing single-molecule dissociation over an 85 min experiment. Our new CFM module facilitates simple and inexpensive experiments that dramatically improve access to single-molecule analysis.

Living Cells and Dynamic Molecules Observed with the Polarized Light Microscope: the Legacy of Shinya Inoué

In 1948, Shinya Inoué arrived in the United States for graduate studies at Princeton. A year later he came to Woods Hole, starting a long tradition of summer research at the Marine Biological Laboratory (MBL), which quickly became Inoué's scientific home. Primed by his Japanese mentor, Katsuma Dan, Inoué followed Dan's mantra to work with healthy, living cells, on a fundamental problem (mitosis), with a unique tool set that he refined for precise and quantitative observations (polarized light microscopy), and a fresh and brilliant mind that was unafraid of challenging current dogma. Building on this potent combination, Inoué contributed landmark observations and concepts in cell biology, including the notion that there are dynamic, fine structures inside living cells, in which molecular assemblies such as mitotic spindle fibers exist in delicate equilibrium with their molecular building blocks suspended in the cytoplasm. In the late 1970s and 1980s, Inoué and others at the MBL were instrumental in conceiving video microscopy, a groundbreaking technique which married light microscopy and electronic imaging, ushering in a revolution in how we know and what we know about living cells and the molecular mechanisms of life. Here, we recount some of Inoué's accomplishments and describe how his legacy has shaped current activities in polarized light imaging at the MBL.

Characterization and classification of adherent cells in monolayer culture using automated tracking and evolutionary algorithms

This paper presents a novel method for tracking and characterizing adherent cells in monolayer culture. A system of cell tracking employing computer vision techniques was applied to time-lapse videos of replicate normal human uro-epithelial cell cultures exposed to different concentrations of adenosine triphosphate (ATP) and a selective purinergic P2X antagonist (PPADS), acquired over a 24h period. Subsequent analysis following feature extraction demonstrated the ability of the technique to successfully separate the modulated classes of cell using evolutionary algorithms. Specifically, a Cartesian Genetic Program (CGP) network was evolved that identified average migration speed, in-contact angular velocity, cohesivity and average cell clump size as the principal features contributing to the separation. Our approach not only provides non-biased and parsimonious insight into modulated class behaviours, but can be extracted as mathematical formulae for the parameterization of computational models.

Impact of New Camera Technologies on Discoveries in Cell Biology

New technologies can make previously invisible phenomena visible. Nowhere is this more obvious than in the field of light microscopy. Beginning with the observation of "animalcules" by Antonie van Leeuwenhoek, when he figured out how to achieve high magnification by shaping lenses, microscopy has advanced to this day by a continued march of discoveries driven by technical innovations. Recent advances in single-molecule-based technologies have achieved unprecedented resolution, and were the basis of the Nobel prize in Chemistry in 2014. In this article, we focus on developments in camera technologies and associated image processing that have been a major driver of technical innovations in light microscopy. We describe five types of developments in camera technology: video-based analog contrast enhancement, charge-coupled devices (CCDs), intensified sensors, electron multiplying gain, and scientific complementary metal-oxide-semiconductor cameras, which, together, have had major impacts in light microscopy.

Extraction of Blebs in Human Embryonic Stem Cell Videos

Blebbing is an important biological indicator in determining the health of human embryonic stem cells (hESC). Especially, areas of a bleb sequence in a video are often used to distinguish two cell blebbing behaviors in hESC: dynamic and apoptotic blebbings. This paper analyzes various segmentation methods for bleb extraction in hESC videos and introduces a bio-inspired score function to improve the performance in bleb extraction. Full bleb formation consists of bleb expansion and retraction. Blebs change their size and image properties dynamically in both processes and between frames. Therefore, adaptive parameters are needed for each segmentation method. A score function derived from the change of bleb area and orientation between consecutive frames is proposed which provides adaptive parameters for bleb extraction in videos. In comparison to manual analysis, the proposed method provides an automated fast and accurate approach for bleb sequence extraction.

Intravital Microscopy on a Closed Cranial Window in Mice: A Model to Study Trigeminovascular Mechanisms Involved in Migraine

The purpose of the study was to develop a mouse model to study trigeminovascular mechanisms using intravital microscopy on a closed cranial window. In addition, we studied exogenous and endogenous calcitonin gene-related peptide (CGRP)-mediated vasodilation in dural arteries. Arteries in C57BL/6Jico mice were constricted with endothelin-1, which reduced the baseline diameter by 65-75%. Subsequently, vasodilation was induced by α-CGRP, capsaicin or transcranial electrical stimulation of perivascular trigeminal nerves in the absence or presence of different concentrations of BIBN4096BS or sumatriptan. Both α-CGRP and capsaicin induced vasodilation in preconstricted arteries. Transcranial electrical stimulation also induced current-dependent relaxation of dural arteries with 100 μA producing maximal dilation in the control group. BIBN4096BS blocked the responses evoked by ä-CGRP and capsaicin, as well as electrical stimulation, whereas sumatriptan attenuated only vasodilation induced by electrical stimulation. This model is likely to prove useful in dissecting elements of the trigeminovascular system and for exploring pathophysiological aspects of migraine, especially in future studies using transgenic mice with mutations relevant to those observed in patients with migraine.

Time-Lapse Imaging of Cell Death

The best approach to distinguish between necrosis and apoptosis is time-lapse video microscopy. This technique enables a biological process to be photographed at regular intervals over a period, which may last from a few hours to several days, and can be applied to cells in culture or in vivo. We have established two time-lapse microscopy methods based on different ways of calculating cell death: semiautomated and automated. In the semiautomated approach, cell death can be visualized by staining with combinations of Alexa Fluor 647-conjugated Annexin V and Sytox Green (SG), or Annexin V(FITC) and Propidium iodide (PI). The automated method is similar except that all cells are labeled with dyes. This allows faster quantification of data. To this end Cell Tracker Green is used to label all cells at time zero in combination with PI and Alexa Fluor 647-conjugated Annexin V. Necrotic cell death is accompanied by either simultaneous labeling with Annexin V and PI or SG (double-positive), or direct PI or SG staining. Additionally, necrotic cells display characteristic morphology, such as cytoplasmic swelling. In contrast to necrosis where membrane permeabilization is an early event, cells that die by apoptosis lose their membrane permeability relatively late. Therefore, the time between Annexin V staining and PI or SG uptake (double-positive) can be used to distinguish necrosis from apoptosis. This protocol describes the analysis of cell death by time-lapse imaging of HT1080 and L929 cells stained with these dyes, but it can be readily adapted to other cell types of interest.

Simple non-invasive analysis of embryonic stem cell-derived cardiomyocytes beating in vitro

The analysis of digital video output enables the non-invasive screening of various active biological processes. For the monitoring and computing of the beating parameters of cardiomyocytes in vitro, CB Analyser (cardiomyocyte beating analyser) software was developed. This software is based on image analysis of the video recording of beating cardiomyocytes. CB Analyser was tested using cardiomyocytes derived from mouse embryonic stem cells at different stages of cardiomyogenesis. We observed that during differentiation (from day 18), the beat peak width decreased, which corresponded to the increased speed of an individual pulse. However, the beating frequency did not change. Further, the effects of epinephrine modulating mature cardiomyocyte functions were tested to validate the CB Analyser analysis. In conclusion, data show that CB Analyser is a useful tool for evaluating the functions of both developing and mature cardiomyocytes under various conditions in vitro.

Video Telescope Operating Microscopy

Exotic pet veterinarians frequently have to operate on small animals, and magnification is commonly used. Existing endoscopy equipment can be used with a mechanical arm and telescope to enable video telescope operating microscopy. The additional equipment items and their specifics are described, and several case examples are provided.

Rapid palatal expansion: the role of microcirculation

AIM

Transverse palate modifications fall under expansive orthopedic therapy of the upper maxilla. The only practical approach to the problem on the transverse plane is that of performing the expansion of the maxillary arch through an opening of the median palatal suture. It is important to understand the changes of the vascular network in midpalatal suture following the starting of rapid maxillary expansion. It is critical to maintain the blood supply and circulation for the osteogenesis and bone remodeling after the expansion. The aim of this research was to evaluate the effects of rapid orthopedic expansion (REP) at the microcirculatory level through capillaroscopic examination.

METHODS

Fifteen patients in their developing years between 9 and 15 years of age (average age 12.16 years) were examined. The application of the REP was the first step in the planning of orthopedic-orthodontic treatment which foresaw further stages in the odonto-osseous movement. The method of Biomicroscopic Video-Imaging of the microcirculation of oral mucosa is performed through the technique of computerized capillaroscopy and the related software.

RESULTS

From the results it is evident that immediately after achieving the expansion of the upper maxilla (t1), a slight decrease in the number of vessels per mm² can be observed. In addition, a slight ectasia can be observed in these vessels in comparison to t0. Comparing the videocapillaroscopic images of t1 and t2, an increase in the capillaries per mm² can be observed.

CONCLUSION

Ectasia of the capillaries, though subject to strictly individual variables, can be considered perfectly normal and it is compatible with the normal biology and physiology of vessel microcirculation.

Logarithmic intensity compression in fluorescence guided surgery applications

The use of fluorescence video imaging to guide surgery is rapidly expanding, and improvements in camera readout dynamic range have not matched display capabilities. Logarithmic intensity compression is a fast, single-step mapping technique that can map the useable dynamic range of high-bit fluorescence images onto the typical 8-bit display and potentially be a variable dynamic contrast enhancement tool. We demonstrate a ∼4.6  times improvement in image quality quantified by image entropy and a dynamic range reduction by a factor of ∼380 by the use of log-compression tools in processing in vivo fluorescence images.

Intraoperative imaging during Mohs surgery with reflectance confocal microscopy: initial clinical experience

Mohs surgery for the removal of nonmelanoma skin cancers (NMSCs) is performed in stages, while being guided by the examination for residual tumor with frozen pathology. However, preparation of frozen pathology at each stage is time consuming and labor intensive. Real-time intraoperative reflectance confocal microscopy(RCM), combined with video mosaicking, may enable rapid detection of residual tumor directly in the surgical wounds on patients. We report our initial experience on 25 patients, using aluminum chloride for nuclear contrast. Imaging was performed in quadrants in the wound to simulate the Mohs surgeon’s examination of pathology. Images and videos of the epidermal and dermal margins were found to be of clinically acceptable quality. Bright nuclear morphology was identified at the epidermal margin and detectable in residual NMSC tumors. The presence of residual tumor and normal skin features could be detected in the peripheral and deep dermal margins. Intraoperative RCM imaging may enable detection of residual tumor directly on patients during Mohs surgery, and may serve as an adjunct for frozen pathology. Ultimately, for routine clinical utility, a stronger tumor-to-dermis contrast may be necessary, and also a smaller microscope with an automated approach for imaging in the entire wound in a rapid and controlled manner.

Quantitative phase microscopy: automated background leveling techniques and smart temporal phase unwrapping

In order for time-dynamic quantitative phase microscopy to yield meaningful data to scientists, raw phase measurements must be converted to sequential time series that are consistently phase unwrapped with minimal residual background shape. Beyond the initial phase unwrapping, additional steps must be taken to convert the phase to time-meaningful data sequences. This consists of two major operations both outlined in this paper and shown to operate robustly on biological datasets. An automated background leveling procedure is introduced that consistently removes background shape and minimizes mean background phase value fluctuations. By creating a background phase value that is stable over time, the phase values of features of interest can be examined as a function of time to draw biologically meaningful conclusions. Residual differences between sequential frames of data can be present due to inconsistent phase unwrapping, causing localized regions to have phase values at similar object locations inconsistently changed by large values between frames, not corresponding to physical changes in the sample being observed. This is overcome by introducing a new method, referred to as smart temporal unwrapping that temporally unwraps and filters the phase data such that small motion between frames is accounted for and phase data are unwrapped consistently between frames. The combination of these methods results in the creation of phase data that is stable over time by minimizing errors introduced within the processing of the raw data.

3D tracking the Brownian motion of colloidal particles using digital holographic microscopy and joint reconstruction

In-line digital holography is a valuable tool for sizing, locating, and tracking micro- or nano-objects in a volume. When a parametric imaging model is available, inverse problem approaches provide a straightforward estimate of the object parameters by fitting data with the model, thereby allowing accurate reconstruction. As recently proposed and demonstrated, combining pixel super-resolution techniques with inverse problem approaches improves the estimation of particle size and 3D position. Here, we demonstrate the accurate tracking of colloidal particles in Brownian motion. Particle size and 3D position are jointly optimized from video holograms acquired with a digital holographic microscopy setup based on a low-end microscope objective (×20, NA 0.5). Exploiting information redundancy makes it possible to characterize particles with a standard deviation of 15 nm in size and a theoretical resolution of 2×2×5  nm³ for position under additive white Gaussian noise assumption.

Point-of-care quantification of blood-borne filarial parasites with a mobile phone microscope

Parasitic helminths cause debilitating diseases that affect millions of people in primarily low-resource settings. Efforts to eliminate onchocerciasis and lymphatic filariasis in Central Africa through mass drug administration have been suspended because of ivermectin-associated serious adverse events, including death, in patients infected with the filarial parasite Loa loa. To safely administer ivermectin for onchocerciasis or lymphatic filariasis in regions co-endemic with L. loa, a strategy termed "test and (not) treat" has been proposed whereby those with high levels of L. loa microfilariae (>30,000/ml) that put them at risk for life-threatening serious adverse events are identified and excluded from mass drug administration. To enable this, we developed a mobile phone-based video microscope that automatically quantifies L. loa microfilariae in whole blood loaded directly into a small glass capillary from a fingerprick without the need for conventional sample preparation or staining. This point-of-care device automatically captures and analyzes videos of microfilarial motion in whole blood using motorized sample scanning and onboard motion detection, minimizing input from health care workers and providing a quantification of microfilariae per milliliter of whole blood in under 2 min. To validate performance and usability of the mobile phone microscope, we tested 33 potentially Loa-infected patients in Cameroon and confirmed that automated counts correlated with manual thick smear counts (94% specificity; 100% sensitivity). Use of this technology to exclude patients from ivermectin-based treatment at the point of care in Loa-endemic regions would allow resumption/expansion of mass drug administration programs for onchocerciasis and lymphatic filariasis in Central Africa.

Intravital live cell triggered imaging system reveals monocyte patrolling and macrophage migration in atherosclerotic arteries

Intravital multiphoton imaging of arteries is technically challenging because the artery expands with every heartbeat, causing severe motion artifacts. To study leukocyte activity in atherosclerosis, we developed the intravital live cell triggered imaging system (ILTIS). This system implements cardiac triggered acquisition as well as frame selection and image registration algorithms to produce stable movies of myeloid cell movement in atherosclerotic arteries in live mice. To minimize tissue damage, no mechanical stabilization is used and the artery is allowed to expand freely. ILTIS performs multicolor high frame-rate two-dimensional imaging and full-thickness three-dimensional imaging of beating arteries in live mice. The external carotid artery and its branches (superior thyroid and ascending pharyngeal arteries) were developed as a surgically accessible and reliable model of atherosclerosis. We use ILTIS to demonstrate Cx3cr1GFP monocytes patrolling the lumen of atherosclerotic arteries. Additionally, we developed a new reporter mouse (Apoe−/−Cx3cr1GFP/+Cd11cYFP) to image GFP+ and GFP+YFP + macrophages “dancing on the spot” and YFP+ macrophages migrating within intimal plaque. ILTIS will be helpful to answer pertinent open questions in the field, including monocyte recruitment and transmigration, macrophage and dendritic cell activity, and motion of other immune cells.

[OPTICAL BIOPSY FOR DIAGNOSIS OF ESOPHAGEAL MUCOSAL CHANGES IN CHILDREN]

AIM

To analyze the value of confocal laser endomicroscopy in diagnostics of upper gastrointestinal tract mucosa changes in children.

PATIENTS AND METHODS

In the current study a total of 116 children aged from 3 to 18 years old undergo conventional endoscopy with confocal laser endomicroscopy supplemented with mucosal biopsy followed by traditional histology in the period from 2011 until 2014. To determine the prognostic value of the of probe based CLE in the evaluation of normal and pathological changes of the esophageal mucosa a comparison of results of optical biopsy with the data obtained during the standard histological examination were performed.

RESULTS

After results of probe-based CLE and traditional histology were comprised optical biopsy showed 88.8% sensitivity and 88.3% specificity to esophagitis with Spearmen correlation 0.79 (p = 0.001); 92.3% sensitivity and 95.3% specificity to metaplastic changes of esophageal mucosa with Spearmen correlation 0.85 (p = 0.001); 92.4% sensitivity and 95.2% specificity in differential diagnosis of esophageal polyps with Spearmen correlation 0.95 (p = 0.001).

CONCLUSION

Confocal endomicroscopy may become one of the leading methods in pediatric gastroenterology since it allows the endoscopists to inspect the mucosa at the cellular level during the endoscopic procedure and can help in establishing the diagnosis.

Poor agreement between endoscopists and gastrointestinal pathologists for the interpretation of probe-based confocal laser endomicroscopy findings

AIM: To compare the interpretation of probe-based confocal laser endomicroscopy (pCLE) findings between endoscopists and gastrointestinal (GI)-pathologists.

METHODS: All pCLE procedures were undertaken and the endoscopist rendered assessment. The same pCLE videos were then viewed offline by an expert GI pathologist. Histopathology was considered the gold standard for definitive diagnosis. The sensitivity, specificity and accuracy for diagnosis of dysplastic/ neoplastic GI lesions and interobserver agreement between endoscopists and experienced gastrointestinal pathologist for pCLE findings were analyzed.

RESULTS: Of the 66 included patients, 40 (60.6%) had lesions in the esophagus, 7 (10.6%) in the stomach, 15 (22.7%) in the biliary tract, 3 (4.5%) in the ampulla and 1 (1.5%) in the colon. The overall sensitivity, specificity and accuracy for diagnosing dysplastic/neoplastic lesions using pCLE were higher for endoscopists than pathologist at 87.0% vs 69.6%, 80.0% vs 40.0% and 84.8% vs 60.6% (P = 0.0003), respectively. Area under the ROC curve (AUC) was greater for endoscopists than the pathologist (0.83 vs 0.55, P = 0.0001). Overall agreement between endoscopists and pathologist was moderate for all GI lesions (K = 0.43; 95%CI: 0.26-0.61), luminal lesions (K = 0.40; 95%CI: 0.20-0.60) and those of dysplastic/neoplastic pathology (K = 0.55; 95%CI: 0.37-0.72), the agreement was poor for benign (K = 0.13; 95%CI: -0.097-0.36) and pancreaticobiliary lesions (K = 0.19; 95%CI: -0.26-0.63).

CONCLUSION: There is a wide discrepancy in the interpretation of pCLE findings between endoscopists and pathologist, particularly for benign and malignant pancreaticobiliary lesions. Further studies are needed to identify the cause of this poor agreement.

Sequential-digital image correlation for mapping human posterior sclera and optic nerve head deformation

Optic nerve head (ONH) deformations may be involved in the onset or further development of glaucoma, including in patients with relatively normal intraocular pressures (IOPs). Characterizing posterior scleral deformations over physiological pressures may provide a better understanding of how changes in IOP lead to changes in the mechanical environment of the ONH and possibly retinal ganglion cell death. Pressure inflation measurement test protocols are commonly used to measure deformation of the peripapillary sclera with full-field noncontact optical methods. The purpose of this work was to develop and validate a new sequential 3D digital image correlation (S-DIC) approach for quantification of posterior scleral pressure induced deformation that improves z (in-depth) resolution of the DIC measurement without losing in-plane sensitivity, while also being able to contour and map deformations of the complex-shaped ONH. Our approach combines two orthogonal axes of parallax with standard 3D DIC methods using a single high-resolution camera. The enhanced capabilities of S-DIC with respect to standard 3D DIC has been demonstrated by carrying out a complete benchmark for shape, deformation, and strain measurement on an object of known complex geometry. Our S-DIC method provided a reconstruction accuracy of 0.17% and an uncertainty in z-position measurement of 8 μm. The developed methodology has also been applied to a human posterior scleral shell, including the full peripapillary sclera and optic nerve. The relatively inexpensive S-DIC approach may provide new information on the biomechanical deformations of the optic nerve head and, thus, the death of retinal ganglion cells in primary open angle glaucoma.

3-D gel culture and time-lapse video microscopy of the human vestibular nerve

CONCLUSIONS

Human inner ear neurons have an innate regenerative capacity and can be cultured in vitro in a 3-D gel. The culture technique is valuable for experimental investigations of human inner ear neuron signaling and regeneration.

OBJECTIVES

To establish a new in vitro model to study human inner ear nerve signaling and regeneration.

METHODS

Human superior vestibular ganglion (SVG) was harvested during translabyrinthine surgery for removal of vestibular schwannoma. After dissection tissue explants were embedded and cultured in a laminin-based 3-D matrix (Matrigel™). 3-D growth cone (GC) expansion was analyzed using time-lapse video microscopy (TLVM). Neural marker expression was appraised using immunocytochemistry with fluorescence and laser confocal microscopy.

RESULTS

Tissue explants from adult human SVG could be cultured in 3-D in a gel, indicating an innate potential for regeneration. Cultured GCs were found to expand dynamically in the gel. Growth cone expansion and axonal Schwann cell alignment were documented using TLVM. Neurons were identified morphologically and through immunohistochemical staining.

Lipid vesicle shape analysis from populations using light video microscopy and computer vision

We present a method for giant lipid vesicle shape analysis that combines manually guided large-scale video microscopy and computer vision algorithms to enable analyzing vesicle populations. The method retains the benefits of light microscopy and enables non-destructive analysis of vesicles from suspensions containing up to several thousands of lipid vesicles (1–50 µm in diameter). For each sample, image analysis was employed to extract data on vesicle quantity and size distributions of their projected diameters and isoperimetric quotients (measure of contour roundness). This process enables a comparison of samples from the same population over time, or the comparison of a treated population to a control. Although vesicles in suspensions are heterogeneous in sizes and shapes and have distinctively non-homogeneous distribution throughout the suspension, this method allows for the capture and analysis of repeatable vesicle samples that are representative of the population inspected.