Historical and Clinical Importance of the Sevier Munger Stain - Research Paper Example

?Running Head: Health Sciences and Medicine Historical and Clinical Importance of the Sevier-Munger Stain A Descriptive Paper of Professor Date of Submission Introduction Recently, several techniques for the silver staining of nervous tissues’ paraffin parts have been identified. Perhaps one of the most significant has been that of Sevier and Munger (1965). The Sevier-Munger stain is definite for enterochromaffin-like cells (ECL)—a unique form of neuroendocrine cell-- that shape the carcinoids, or a form of neuroendocrine tumor. The importance of carcinoids in rats has achieved significant consideration with the discovery that contact with herbicides lead to heightened pace of these tumors (Bruce-Gregorios, 2006). Contact with methyleugenol, which is commonly obtained in beverages and foods, is linked to heightened tempo of gastric carcinoids in rats as well. In numerous instances, the carcinoids could be minor to enlarged serum gastrin, enlarged gastric PH, and gastric-induced tropic impacts on ECL (Bruce-Gregorios, 2006). Sevier-Munger’s argyrophil silver stain was analyzed in rat thyroid parafollicular cells following Bouin fixation and formalin. The most simply reproducible and greatest staining reaction was acquired in Bouin-fixed and Sevier-Munger-stained tissues (Watts & Koller, 2004). Developments in methods of silver staining have frequently been gained from the chemistry field. The ammoniacal silver solution had been utilized for mirror making, rooted in the features of the intricate ‘silver diamine’ in the mixture that is predisposed to crystallize, after being condensed, at the border between the mixture and the surface of the glass (Hirth et al., 1988). This is referred to as the ‘silver mirror reaction’ and this was originally used in tissue staining by Fajersztajn. Soon after, Max Bielschowsky developed this technique by breeding formalin-fixed solidified areas in the silver nitrate before the ammoniacal silver solution (Hirth et al., 1988). Even though the precise process is yet to be explained, it is possible that this earlier administration of silver nitrate offers functional cores for later silver sedimentation in the ammoniacal silver mixture. In any case, it is logical to assume that the stepwise impregnation enhanced the staining perhaps by boosting the mass and level of silver precipitates (Hirth et al., 1988). Original adjustments of Bielschowsky technique were summed up by Beech and Davenport. The existence of so many adjustments, nevertheless, shows that this technique is very unstable and remains open to enhancements. An adjustment for paraffin-implanted pieces of typical neural tissues from different kinds of animal was originally suggested by Sevier and Munger (Uchihara, 2007). In the course of the pre-immunohistochemical period, silver stains were a crucial portion of the staining repository for classifying specific tissue structures and cell forms in tissue areas. Several of them were helpful in explaining endocrine cells, specifically in the gastrointestinal tract (Grimelius, 2004). Silver stains, until the latter part of the 1950s, were attended by several technical setbacks leading to unrestrained staining variables. A new set of silver stains were created for endocrine cell forms in the 1960s, and these stains produced outcomes that were capable of reproduction (Grimelius, 2004). The Sevier-Munger method shows thyroid’s C-cells and ECL, the Grimelius stain is a wide-ranging endocrine cell indicator, and the Masson stain shows the EC cells. Specifically in the pre-immunohistochemical period, these techniques of staining were frequently applied for histopathological examination (Grimelius, 2004). According to Uchihara (2007), the silver stains were created experimentally, and with a small number of omissions the chemical conditions is unidentified. Staining procedures are added. Sevier-Munger Method for Neural Tissue Staining This method is generally applied to show neurofibrillary tangles and neuritic plaques in the brain of individuals with Alzheimer’s disease. Cerebellar basket cell, neurofibrillary tangles, Purkinje cell axos, and neuritic plaques are impregnated excellently with silver in Sevier-Munger method (Bruce-Gregorios, 2006). Large filaments within the spinal cord and brainstem are stained but tiny filaments are not pictured. The olfactory and optic nerves do not stain with this method (Bruce-Gregorios, 2006). Fig. 1. Sevier Munger stain showing neuritic plaques (white arrow) and neurofibrillary tangles (black arrows) in brain, typical of Alzheimer’s disease (Bruce-Gregorios, 2006, 239) Sevier-Munger Methods for Secretory Granules Endocrine cells composed of secretory granules are diagnosed by two major techniques, namely, argyrophil methods, which stain nearly all neuroendocrine cells, and argentaffin preparations, which show mainly EC of the small intestine. Argentaffin-positive cells absorb silver and diminish it to its observable, metallic form without the help of an unrelated diminishing medium (Hirth et al., 1988). On the other hand, showing of argyrophil granules necessitates the insertion of a diminishing medium so as to diminish the impregnated silver to an observable, metallic outcome. Cases in point are Sevier-Munger, Bodian, and Grimelius methods. Theoretically, argyrophil techniques are more responsive, but are less definite than argentaffin stains for endocrine cell demonstration (Hirth et al., 1998). Even though sensitive cells also involve the anterior pituary, the two techniques have been replaced by immunohistochemistry (Watts & Koller, 2004). The Sevier-Munger method for argyrophilia discriminatingly stains a small unit of EC cells and ECL cells. Nevertheless, because the comparative percentage of EC cells stained by Sevier-Munger is insignificant, the method is presently considered as essentially definite for ECL cells in paraffin-implanted, formalin-fixed tissues prepared for light microscopy (Grimelius, 2004). Nevertheless, because the Sevier-Munger stain is theoretically complicated and quite impulsive, a lot of workers depend on the Grimelius stain for picturing ECL cells, understanding completely that the quantity of fully stained cells is an imprecise demonstration of their quantities because this method stains as well other argyrophil cells found in oxyntic mucosa (Watts & Koller, 2004). The ECL cells in humans are basically classified by their topographic division, their capacity to stain with the Sevier-Munger and Grimelius stains for argyrophilia. The ECL cell particles are morphologically diverse (Uchihara, 2007). Quite plentiful, and considered as typical of ECL cells, are the big membrane-confined vesicles that have an oddly positioned uneven, rough surfaced electron thick argyrophil center. Also, there may be an erratically sized marginal group of tiny round particles as well with a uniform roughly granular center enclosed by a corona confined by a fragile, curvy restricting membrane (Bruce-Gregorios, 2006). According to Hirth and colleagues (1988), although several ECL cells are composed of both forms of particles, others may exhibit just the tiny particles in their cytoplasm. Conclusions Basically, the Sevier-Munger stain has been the product of a series of modification in silver staining. The Sevier-Munger staining method is essentially applied in microscopy to improve visibility in the microscopic picture. This method is used to emphasize parts and compositions in biological tissues for demonstration. The method is used mainly for the demonstration of Alzheimer’s disease and abnormalities of the nervous system. References Bruce-Gregorios, J. (2006). Histopathologic Techniques. Quezon City, Phil: Goodwill Trading Co., Inc. Grimelius, L. (2004). Silver stains demonstrating neuroendocrine cells. Sweden: Department of Genetics and Pathology. Hirth, R., Evans, L., Buroker, R. & Oleson, F. (1988). “Gastric enterochromaffin-like cell hyperplasia and neoplasia in the rat: An indirect effect of the histamine H 2 Receptor Antagonist, BL-6341” Toxicologic Pathology, 16(2), 273+ Sevier, A.C. & Munger, B.L. (1965). “A silver method for paraffin sections of neural tissue” J. Neuropathol. Exp. Neural, 24, 130-135. Uchihara, T. (2007). “Silver diagnosis in neuropathology: principles, practice and revised interpretation” Acta Neuropathol, 113(5), 483-499. Watts, R. & Koller, W. (2004). Movement Disorders: Neurologic Principles & Practice. New York: McGraw-Hill Professional. Read More