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Methods in Molecular Biology (Clifton,... 2017Periodic Acid-Schiff (PAS) with diastase (PAS-D) refers to the use of the PAS stain in combination with diastase, which is an enzyme that digests the glycogen. The...
Periodic Acid-Schiff (PAS) with diastase (PAS-D) refers to the use of the PAS stain in combination with diastase, which is an enzyme that digests the glycogen. The purpose of using the PAS-D procedure is to differentiate glycogen from other PAS-positive elements in tissue samples. The PAS-D method is also used for periportal liver staining of AAT polymer inclusions that are seen in alpha-1 antitrypsin deficiency disease. Here, we describe the procedure of PAS-D staining in formalin-fixed, paraffin-embedded human liver tissues.
Topics: Amylases; Humans; Liver; Paraffin Embedding; Periodic Acid; Staining and Labeling
PubMed: 28752454
DOI: 10.1007/978-1-4939-7163-3_14 -
Methods in Molecular Biology (Clifton,... 2017The detection of fungal elements and their characterization in patient specimens provides fundamental information. On histological sections fungi are most frequently...
The detection of fungal elements and their characterization in patient specimens provides fundamental information. On histological sections fungi are most frequently seen on skin or mucosal surfaces or as mycotic thrombi or emboli that can occlude both arteries and veins in surgical specimen from immunocompromised patients or tissues obtained from autopsies. Microbial culture continues to be the central method for diagnosing fungal infection but is complemented by histomorphology using specific stains capable of identifying previously unsuspected fungal infections or for evaluating tissue invasion. These stains employ oxidizing reagents to create aldehyde binding sites on polysaccharides (1,2-glycol groups) of fungal cell walls for either Schiff's reagent or Silver ions. Gomori methenamine silver (GMS) and Periodic acid-Schiff (PAS) or their modifications are the most commonly used for tissue sections and in cytology specimens.
Topics: Humans; Mycoses; Staining and Labeling; Tissue Embedding
PubMed: 27837504
DOI: 10.1007/978-1-4939-6515-1_9 -
Methods in Molecular Biology (Clifton,... 2022Vasculogenic mimicry (VM), a tumor microcirculation model found in melanoma in the last 20 years, is a vascular channel-like structure composed of tumor cells, but...
Vasculogenic mimicry (VM), a tumor microcirculation model found in melanoma in the last 20 years, is a vascular channel-like structure composed of tumor cells, but without endothelial cells, that stains positive for periodic acid-Schiff (PAS) and negative staining for CD31. VM provides, to the highly aggressive malignant tumor cells, adequate oxygen and nutrient supply for tumor growth and subsequent metastasis process and its presence are related to poor prognosis in patients. VM is independent of endothelial cells, which may partly explain why angiogenesis drug inhibitors have not achieved the expected success for cancer treatment.
Topics: Endothelial Cells; Humans; Melanoma; Microcirculation; Neovascularization, Pathologic
PubMed: 35771413
DOI: 10.1007/978-1-0716-2403-6_1 -
JAAD Case Reports Jun 2022
PubMed: 35774223
DOI: 10.1016/j.jdcr.2022.05.013 -
Methods in Molecular Biology (Clifton,... 2022Vasculogenic mimicry (VM) describes a new tumor microvascular paradigm of non-endothelial cells, where aggressive cancer cells independent of angiogenesis acquire the... (Review)
Review
Vasculogenic mimicry (VM) describes a new tumor microvascular paradigm of non-endothelial cells, where aggressive cancer cells independent of angiogenesis acquire the ability to fluid-conducting vessels. VM shows worse 5-year overall survival in cancer that suggesting that VM could be a promising surgical and effective adjuvant therapy strategy in prognostics of metastatic cancer patients. The current chapter is a comprehensive review on "Main Staining Methods and Protocols in Vasculogenic Mimicry." Here, we provide most up-to-date and detailed information upon microscopy and histology protocols for the identification and understanding of VM process in both in vitro and in vivo.
Topics: Humans; Neovascularization, Pathologic; Staining and Labeling
PubMed: 35771423
DOI: 10.1007/978-1-0716-2403-6_11 -
Paediatric Respiratory Reviews Sep 2022Actinomycosis is a rare, indolent and invasive infection caused by Actinomyces species. Actinomycosis develops when there is disruption of the mucosal barrier, and... (Review)
Review
Actinomycosis is a rare, indolent and invasive infection caused by Actinomyces species. Actinomycosis develops when there is disruption of the mucosal barrier, and invasion and systemic spread of the organism, which can lead to endogenous infection affecting numerous organs. It is known to spread in tissue through fascial planes and most often involves the cervicofacial (55%), abdominopelvic (20%) and thoracic (15%) soft tissue. Pulmonary actinomycosis is rare in patients under the age of five years, with the median reported age in the fifth decade. Clinical findings include chest wall mass (49%), cough (40%), pain (back, chest, shoulders) (36%), weight loss (19%), fever (19%), Draining sinuses (15%) and hemoptysis (9%). Chest x-ray findings in pulmonary actinomycosis are mostly nonspecific and can overlap with pulmonary tuberculosis, foreign body aspiration and malignancy. Endobronchial tissue aggregates may show sulphur granules, with yellow to white conglomerate areas of gram positive Actinomyces. Removal or biopsy of these large endobronchial masses must be done with care, because of the risk of bleeding and large airway obstruction. The cytology on bronchoalveolar lavage fluid may show Periodic acid-Schiff (PAS) positive stain, ZN negative and Gram-positive filamentous bacilli which is morphologically suggestive of Actinomycosis. Actinomyces spp is highly susceptible to beta lactam antibiotics, penicillin G, and amoxicillin. A minimum of 3-6 months is needed but up to 20 months of treatment may be needed. Early diagnosis and correct treatment can lead to a good prognosis with a low mortality.
Topics: Humans; Child; Child, Preschool; Periodic Acid; Actinomycosis; Actinomyces; Lung Diseases; Penicillin G; Amoxicillin; Sulfur
PubMed: 34610895
DOI: 10.1016/j.prrv.2021.09.001 -
Seminars in Diagnostic Pathology Nov 2018Histochemical methods (HM) were, at one time, extensively used in all facets of anatomic pathology, including analysis of soft tissue lesions. That situation has changed... (Review)
Review
Histochemical methods (HM) were, at one time, extensively used in all facets of anatomic pathology, including analysis of soft tissue lesions. That situation has changed with the advent of other adjunctive procedures, but HM still do contribute meaningfully to the evaluation of several tumefactive conditions in the soft tissue. This brief review considers selected neoplastic, quasineoplastic, and pseudoneoplastic lesions in that category, with emphasis on their histochemical properties.
Topics: Biopsy; Connective Tissue; Connective Tissue Diseases; Histocytochemistry; Humans; Predictive Value of Tests; Prognosis; Soft Tissue Neoplasms; Staining and Labeling
PubMed: 30366792
DOI: 10.1053/j.semdp.2018.10.005 -
BMC Ophthalmology Mar 2021To report sampling of the trabecular meshwork using the TrabEx+ (MicroSurgical Technology, Redmond, Washington, USA) device in ab interno trabeculectomy. Specifically,...
BACKGROUND
To report sampling of the trabecular meshwork using the TrabEx+ (MicroSurgical Technology, Redmond, Washington, USA) device in ab interno trabeculectomy. Specifically, this series focusses upon preservation of the trabecular meshwork architecture for assessment of glaucomatous features using common histopathological techniques.
PATIENTS
This series features six glaucomatous eyes undergoing TrabEx+ with or without cataract surgery. Three patients had primary open angle glaucoma and the remaining had pigment dispersion glaucoma, ocular hypertension or uveitic glaucoma. Four eyes had simultaneous cataract surgery.
METHODS
Trabecular meshwork was excised using the TrabEx+ device and retrieved using vitreoretinal forceps. The samples were then processed into formalin-fixed paraffin-embedded 4 micron tissue segments and stained with haematoxylin and eosin, periodic acid-Schiff and elastin Van Gieson. Collagen IV was labelled using immunohistochemistry for the purpose of identifying the basement membrane of trabecular beams.
RESULTS
Presence of trabecular meshwork was confirmed in five of the six samples taken. One of six samples consisted of blood only, but this was expected following early termination of the procedure due to patient restlessness. In the five positive cases trabecular beams with associated trabecular meshwork cells were identified on hematoxylin-eosin and periodic acid-Schiff staining. The beams retained their lamellar structure. The basement membrane underlying the trabecular cells was evident in three specimens, whilst two specimens were of insufficient size for collagen IV labelling.
CONCLUSIONS
This case series illustrates that TrabEx+ can be utilised to successfully retrieve trabecular meshwork samples with sufficient architectural perseveration of the tissue to enable histopathological and laboratory analysis.
Topics: Glaucoma; Glaucoma, Open-Angle; Humans; Sclera; Trabecular Meshwork; Trabeculectomy
PubMed: 33740938
DOI: 10.1186/s12886-021-01895-6 -
The American Journal of Dermatopathology Dec 2023Periodic acid-Schiff (PAS) stain is a commonly used ancillary test for inflammatory and infectious dermatoses, yet infrequently changes the diagnosis. Previous studies... (Review)
Review
Periodic acid-Schiff (PAS) stain is a commonly used ancillary test for inflammatory and infectious dermatoses, yet infrequently changes the diagnosis. Previous studies have shown that clinical suspicion and histopathologic features are poor predictors of PAS positivity. Current appropriate use criteria from the American Society of Dermatopathology supports PAS staining when histopathologic features could be consistent with a dermatophyte infection. At the authors' institution, PAS stains are preordered on biopsies of inflammatory and infectious diagnoses to aid in a timelier sign out. Our aim was to reduce the percentage of PAS stains preordered on all dermatology specimens over a 6-month period without reducing the percentage of fungal infections identified. Review of a 12-month preintervention period found that our laboratory received 6104 biopsies for which PAS stain was preordered on 616 (10.1%). Based on a review of the preintervention period, preordering PAS on cases with clinical suspicion for cutaneous T-cell lymphoma was stopped unless there was clinical suspicion for eczematous dermatitis, vesiculobullous disorders, or fungal infection. The proposed intervention resulted in a 3.7% reduction in the number of PAS stains ordered while PAS-positivity rate remained unchanged. The described quality improvement process may be used as a model for other laboratories.
Topics: Humans; Periodic Acid; Quality Improvement; Coloring Agents; Staining and Labeling; Skin Neoplasms
PubMed: 37883931
DOI: 10.1097/DAD.0000000000002570 -
Ocular Oncology and Pathology Sep 2021The goal of this study was to histopathologically evaluate the appearance of degrading MIRAgel scleral buckles so that they can be reliably distinguished by ophthalmic...
INTRODUCTION
The goal of this study was to histopathologically evaluate the appearance of degrading MIRAgel scleral buckles so that they can be reliably distinguished by ophthalmic pathologists from other foreign materials.
METHODS
Retrospective chart review and histopathologic study with special stains, including Alcian blue, periodic acid-Schiff, Masson's trichrome, and Perls' Prussian blue for iron, of 4 cases between 2017 and 2019.
RESULTS
Hydrolyzed MIRAgel scleral buckles from 4 patients had a consistent histopathologic appearance. They had a honeycomb structure with the walls of the lattice ranging from distinct to poorly defined. The walls of the lattice were positive for Alcian blue, while the contents of each cell contained periodic acid-Schiff-positive material. Other special stains were not as valuable in highlighting the material.
DISCUSSION
Although the capsules of MIRAgel scleral buckles have been well studied, the material itself has not been. While clinical history and radiographic appearance are often diagnostic of a hydrolyzed MIRAgel scleral buckle, there are instances of preoperative ambiguity where histopathologic confirmation can be useful.
CONCLUSIONS
MIRAgel scleral buckles have a distinct histopathologic appearance that can be readily distinguished from that of other foreign materials.
PubMed: 34604200
DOI: 10.1159/000514299