EDITORIAL: BASIC APPLICATION OF STEREOLOGY IN HISTOLOGY AND MEDICAL SCIENCES
Mahmoudzadeh Sagheb Hamidreza, Bita Moudi · 2014
Copyright © 2014, Zahedan University of Medical Sciences. This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International License (http://creativecommons.org/licenses/by-nc/4.0/) which permits copy and redistribute the material just in noncommercial usages, provided the original work is properly cited. The science of stereology is newfound, extremely active and rapidly developing. Stereology has a special place in three-dimensional studies of quantitative biology and histology. Thus, studies that have used proper stereological techniques, have particular value. This scientific method relies on applied mathematics and statistics with the help of a set of rules, which enable various parameters such as volumes, dimensions, components and the number of components to be estimated. Although measuring parameters in histology such as length, weight and counting parts seems easy, when these parameters are evaluated at the microscopic level, practice approaches are not simple and time efficient. For determining these parameters under microscopic conditions, direct measurement or use of routine techniques are not an option and microscopic techniques are required. Stereology provides knowledge about shapes, images and stereograms, and has pragmatic methods to recognize images and enables calculation of volumes and volume ratio, the area of samples, the number of particles per unit volume, particle size, unit volume and etc. Thus, this technique is very important to obtain reliable quantitative data for various researches in the field of histology. Stereology is generally three-dimensional measurements of microscopic structures. In histological methods we encounter two-dimensional sections or microscopic images. The science of stereology is used to obtain quantitative information based on the observation and analysis of two-dimensional tissue sections or microscopic images in three-dimensional space (1). In fact stereology relies on the knowledge of mathematics and statistical analysis, to obtain extract three-dimensional data from two-dimensional images. Numerous stereological methods have been developed and published, each being specific for different histological tasks. Methods defined in this technique are essential for proper understanding of the structure of tissue, cells, cellular organelles, and other particles in the body of living organisms. On the other hand, understanding the above content is extremely important for studies of histology, embryology and pathology. Today, the science of stereology is the best option for obtaining three-dimensional information from twodimensional images. It is based on geometric probability and integral geometry of the test feature (2). Stereology is derived from a Greek term and means the study of objects in 3D. Analysis of 3D goes back to ancient Egypt and was developed with the introduction of Euclidean geometry (3, 4). Bonaventura Cavalieri (1598-1647), an Italian mathematician and astronomer, was a precursor of infinitesimal calculus. In 1635, during the height of the Italian Renaissance, he provided the basis for volume estimation of biological objects from their areas on tissue sections. Cavalieri in his book, Geometria Indivisibilibus Continuorum: Nova Quadam Ratione Promota (1635) used what is now known as Cavalieri's principle and discussed and strengthened his principle of indivisibles. He stated that “the probe can be used for imaging of a line, lines can be an image of a region, and regions can image size. In this regard a line is made of infinite number of points, a plane is made of infinite number of lines, and a solid is made of infinite number of planes, each indivisible being capable of generating a continuum of a next higher dimension by continuous motion(5). At that time there was another problem when calculating the length of objects. George Leclerc Buffon in 1777 explained this subject by introducing the ‘Needle Problem’. He explained how to calculate the surface area and length of biological objects in an unbiased and accurate manner (3, 4). In fact, stereology was found by a French geologist named August Delesse in 1847 AD. In his article it was stated that, the characteristics of mineral components in two-dimensional cross sections are directly proportional to its three-dimensional volume (6). Subsequently, it was Ar ch ive of SI D