Modern Pathology and Lits of Discovery

The advances in the second half of the 20th century to the most recent times of the 21st century have made it possible to study diseases at the genetic and molecular level and to make an evidence-based and objective diagnosis that can enable the doctor to provide targeted therapy. The major implications of advances in molecular biology are in the diagnosis and treatment of genetic diseases, immunology, and cancer. Modern Pathology helped doctors to understand this. Some of the revolutionary discoveries during this period are discussed below in this article.


human chromosome image
Molecular structure of the human chromosome.


The field of anatomical pathology has evolved in recent decades, and advances have been greatly aided by innovative technology. Immunohistochemistry enabled a paradigm shift in diagnostic discovery and evaluation, followed by booming genomic advances that enabled submicroscopic pathologic characterization, and now the field of digital pathology coupled with machine learning and big data acquisition is paving the way. path to revolutionize the medical domain of pathology. Full Slide Imaging (WSI) is a disruptive technology in which glass slides are digitized to produce full slide images on screen. Specifically, in the last decade, there have been important advances in digital pathology systems that have allowed this technology to promote integration into clinical practice.

Full Slide Images (WSI), or digital slides, can be viewed and navigated comparable to glass slides on a microscope, as digital files. The adoption of full-slide imaging has increased among pathologists, departments of pathology, and scientists for clinical, educational, and research initiatives. Integrating digital pathology systems requires a coordinated effort with numerous stakeholders, not just within the pathology department, but throughout the company. Each pathology department has different needs, use cases, and plans; however, the components and variables of the framework for successful clinical integration can be generalized to any organization seeking to experience digital transformation at any scale. This article will review those components and considerations for integrating digital pathology systems into clinical practice.


List Of Modern Pathology Discoveries:

Description of the structure of DNA of the cell by Watson and Crick in 1953.

Identification of chromosomes and their correct number in humans (46) by Tijo and Levan in 1956.

Identification of Philadelphia chromosome t(9;22) in chronic myeloid leukemia by Nowell and Hagerford in 1960 as the first chromosomal abnormality in any cancer.

In Situ hybridization (ISH) was introduced in 1969 in which a labeled probe is employed to detect and localize specific RNA or DNA sequences ‘in situ (i.e. in the original place). Its later modification employs the use of fluorescence microscopy (FISH) to detect specific localization of the defect on chromosomes.

The recombinant DNA technique was developed in 1972 using restriction enzymes to cut and paste bits of DNA.

The introduction of polymerase chain reaction (PCR) i.e. “xeroxing” of DNA fragments by Kary Mullis in 1983 has revolutionised diagnostic molecular genetics. PCR analysis is more rapid than ISH, can be automated by thermal cyclers and requires a much lower amount of starting DNA.

The invention of flexibility and dynamism of DNA by Barbara McClintock for which she was awarded the Nobel prize in 1983.

Mammalian cloning was started in 1997 by Ian Wilmut and his colleagues at Roslin Institute in Edinburgh, by successfully using a technique of somatic cell nuclear transfer to create the clone of a sheep named Dolly. Reproductive cloning for human beings, however, is very risky besides being absolutely unethical.

The era of stem cell research started in the 2000s by harvesting these primitive cells isolated from embryos and maintaining their growth in the laboratory. There are 2 types of sources of stem cells in humans: embryonic stem cells and adult stem cells, the former being more numerous. Stem cells are seen by many researchers as having virtually unlimited applications in the treatment of many human diseases such as Alzheimer’s disease, diabetes, cancer, strokes, etc. At some point in time, stem cell therapy may be able to replace whole organ transplant,s and instead stem cells ‘harvested’ from the embryo may be used.

Human Genome Project (HGP) consisting of a consortium of countries was completed in April 2003 coinciding with 50 years of the description of DNA double helix by Watson and Crick in April 1953. The sequencing of the human genome reveals that the human genome contains approximately 3 billion base pairs of amino acids, which are located in the 23 pairs of chromosomes within the nucleus of each human cell. Each chromosome contains an estimated 30,000 genes in the human genome which carry the instructions for making proteins. The HGP has given us the ability to read nature’s complete genetic blueprint used in making each human being (i.e. gene mapping). Clinical trials by gene therapy on the treatment of some single gene defects have resulted in some success, especially in hematological and immunological diseases. Future developments in genetic engineering may result in designing new and highly effective individualized treatment options for genetic diseases as well as suggest prevention against diseases.

Method of image capture, commonly a camera mounted on a light microscope.

Telecommunications link between sending and receiving side.

Workstation at receiving end with a high-quality monitor.

Credit & Reference: Harsh Mohan Pathology book


Types of a Telepathology system

Depending upon need and budget, a telepathology system is of two types:


Static (store-and-forward, passive telepathology):

In this, selected images are captured, stored, and then transmitted over the Internet via email attachments, file transfer protocol, web page, or CD-ROM. It is quite inexpensive and more common but has the disadvantage of having sender bias in the selection of transmitted images.

Dynamic (Robotic interactive telepathology):

images are transmitted in real-time from a remote microscope. The robotic movement of the microscope stage is controlled remotely and the desired images and fields are accessed from a remote/local server. Therefore, it almost perfectly duplicates the examination of real slides under the microscope, which is why it is known as virtual microscopy. However, image quality and internet speed can be major obstacles. The era of “digital pathology” in the 21st century has reached its zenith with the availability of technology for the preparation of virtual pathology slides (VPS) using high-speed scanners and then the storage of the scanned data on computers with digital output. large memory. VPS stored in computer memory can be examined and reported anywhere on the computer, without having to use a microscope. However, the moot question remains whether current pathologists accustomed to conventional microscopy will get the same perception on the monitor. Today, this technology has potential for pathology education, record storage, clinical meetings, and quality control.




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