Page 22 - Textbook of Pathology, 6th Edition

6 Another pioneering contribution in pathology in the
20th century was by an eminent teacher-author, William
Boyd (1885–1979), psychiatrist-turned pathologist, whose
textbooks—‘Pathology for Surgeons’ (first edition 1925) and
‘Textbook of Pathology’ (first edition 1932), dominated and
inspired the students of pathology all over the world due
to his flowery language and lucid style for about 50 years
till 1970s (Fig. 1.9). M.M. Wintrobe (1901–1986), a pupil of
Boyd who discovered haematocrit technique, regarded him
SECTION I
as a very stimulating teacher with keen interest in the
development of museum.

MODERN PATHOLOGY (1950s TO PRESENT TIMES)
The strides made in the latter half of 20th century until the
beginning of 21st century have made it possible to study
diseases at molecular level, and provide an evidence-based
and objective diagnosis and enable the physician to institute
appropriate therapy. The major impact of advances in
molecular biology are in the field of diagnosis and treatment
of genetic disorders, immunology and in cancer. Some of
the revolutionary discoveries during this time are as under
(Fig. 1.10):
Description of the structure of DNA of the cell by Watson
and Crick in 1953.
Identification of chromosomes and their correct number Figure 1.9 William Boyd (1885-1979). Canadian pathologist and
in humans (46) by Tijo and Levan in 1956. eminent teacher of pathology who was a pioneering author of textbooks of
pathology which have been read all over the world by students of pathology
Identification of Philadelphia chromosome t(9;22) in and surgery for over 50 years.
chronic myeloid leukaemia by Nowell and Hagerford in 1960
as the first chromosomal abnormality in any cancer. In 1997, Ian Wilmut and his colleagues at Roslin Institute in
In Situ Hybridization introduced in 1969 in which a Edinburgh, successfully used a technique of somatic cell nuclear
General Pathology and Basic Techniques
labelled probe is employed to detect and localize specific transfer to create the clone of a sheep; the cloned sheep was
RNA or DNA sequences ‘in situ’ (i.e. in the original place). named Dolly. This has set in the era of mammalian cloning.
Recombinant DNA technique developed in 1972 using Reproductive cloning for human beings, however, is very risky
restriction enzymes to cut and paste bits of DNA. besides being absolutely unethical.
In 1983, Kary Mullis introduced polymerase chain reaction In 1998, researchers in US found a way of harvesting stem
(PCR) i.e. “xeroxing” DNA fragments which revolutionised cells, a type of primitive cells, from embryos and maintaining
the diagnostic molecular genetics. their growth in the laboratory, and thus started the era of stem
Flexibility and dynamism of DNA invented by Barbara cell research. Stem cells are seen by many researchers as having
McClintock for which she was awarded Nobel prize in 1983. virtually unlimited application in the treatment of many human

Figure 1.10 Molecular structure of human chromosome.