Immunohistochemical Staining for Lymphatic and Blood Vessels in Normal Tissues: Comparison between Routinely Paraffin-Embedded Tissues and Frozen Sections

<p><strong>Objective</strong>. In the current study, we compared the distribution of blood and lymphatic vessels from paraffin-embedded tissues with those of frozen tissues of normal human and rhesus monkey.</p><p><strong> Materials and Methods</strong>. We performed immunocytochemical staining for lymphatic and blood vessels using LYVE-1 for lymphatic vessels and von Willebrand factor (F-8) for blood ves- sels.</p><p><strong>Results</strong>. Normal tissues included spleen, lymph node, liver, pancreas, salivary gland, colon, diaphragm, heart, lung, thyroid, adrenal gland, kidney, ovary, endometrium, and prostate. Splenic sinusoids were stained for LYVE-1 and F-8 in the frozen sections, supporting that the sinusoid is a lymphoreticular system and blood vessel in structure and function. In frozen sections, the lymphatic sinusoids were consistently positive for LYVE-1, while hepatic sinusoids were positive for LYVE-1, but not for F-8. Thus, lymphatic and blood vessels were more readily detected in frozen tissue sections than in the paraffin-embedded sections. In the endometrium, lymphatic vessels were not diffusely immunostained in paraffin-embedded sections. However, frozen sections detected cyclic changes of lymphatic vessels, growing from basalis to functionalis in the menstrual cycle. Lymphatic vessels were immunostained in many organs using frozen sections. Small pulmonary blood vessels were not immunostained by F-8 in the periphery of the bronchial vessel tree most likely these smallest blood vessels were not immunostained due to less F-8 attached to their endothelia. Conclusion. The present findings illustrate the differences in the immunostaining of blood vessels in sections obtained from paraffin-embedded tissues and those from frozen tissue. These new findings may be relevant for the basic histology and histopathology of lymphatic and blood vessels.</p>

Characterization of the retinal vasculature in fundus photos using the PanOptic iExaminer system

Background The goal was to characterize retinal vasculature by quantitative analysis of arteriole-to-venule (A/V) ratio and vessel density in fundus photos taken with the PanOptic iExaminer System. Methods The PanOptic ophthalmoscope equipped with a smartphone was used to acquire fundus photos centered on the optic nerve head. Two fundus photos of a total of 19 eyes from 10 subjects were imaged. Retinal vessels were analyzed to obtain the A/V ratio. In addition, the vessel tree was extracted using deep learning U-NET, and vessel density was processed by the percentage of pixels within vessels over the entire image. Results All images were successfully processed for the A/V ratio and vessel density. There was no significant difference of averaged A/V ratio between the first (0.77 ± 0.09) and second (0.77 ± 0.10) measurements (P = 0.53). There was no significant difference of averaged vessel density (%) between the first (6.11 ± 1.39) and second (6.12 ± 1.40) measurements (P = 0.85). Conclusions Quantitative analysis of the retinal vasculature was feasible in fundus photos taken using the PanOptic ophthalmoscope. The device appears to provide sufficient image quality for analyzing A/V ratio and vessel density with the benefit of portability, easy data transferring, and low cost of the device, which could be used for pre-clinical screening of systemic, cerebral and ocular diseases.

Measuring Lung Vessel Tree Growth During Development in Pediatric Patients

Premature babies are often put on respirators due to their lack of lung development and functionality. However, there is not much data that specifically pinpoints when it is safe to take a child off a respirator. Therefore, the main focus question is: how does the pulmonary vasculature develop as the child grows and can we determine the exact time-point to take him/her off a respirator. In this study, Chest CT scans were retrospectively gathered from pediatric patients at different follow-up times from the UF Shands Pulmonary Care Pediatric Center from 2005-2012. In-house software built upon the NIH ImageJ platform was used to count blood vessels as a function of size in each patient’s lungs. Nine datasets were analyzed from subjects 1 week to 22 years of age. It was observed that the number of vessels increased as a patient aged however the data points were spread greatly, preventing our being able to make additional inferences. Limitations of this initial work include that often patients were scanned only in instances of lung infections which hinders the assessment of lung vasculature; the number of repeated scans per patient was low; and the image slice thickness and in-plane pixel resolution varied across scans, which affects vessels count. Future extensions of this work include selecting a larger cohort of subjects with multiple follow-ups and similar imaging parameters, along with an age-matched control group.