Page 50 - VHSA - Onderstepoort 100 Years - Part 3

OND
ERSTEPOORT 100
One of the routine duties of the pathologists in the Section was to provide a histopathological diagnostic service on preserved organ specimens sent to the Laboratory. In 1932 Jackson wrote a light-hearted article, but with serious undertones, on the advantage of the routine use of the Sudan III staining method of tissue sections of organs after this method had inadvertently been applied to the lung and other organ sections of a bovine suspected to have died from arsenical poisoning, arsenic being a common acaricide used in cattle plunge dips at the time. This staining method is used to demonstrate the presence of fat or oils in tissue sections.
On microscopic examination of the lung sections he found the alveoli to be loaded with fat globules and ‘a diagnosis was made of asphyxia following aspiration of some or other oleaginous material (doubtless O. lini [linseed oil]) used therapeutically.’ At that time and for years thereafter many sick farm animals were dosed by lay persons often while the tongue was held in the mistaken belief that this would facilitate swallowing. The substances dosed supposedly to ‘cure’ the animal were many and varied but often comprised paraffin. Needless to say the outcome often was the development of gangrenous or foreign body pneumonia as a result of the material entering the trachea instead of being swallowed. One cannot but wonder how many thousands of farm animals died needlessly in South Africa as a result of this practice.
most cases of geilsiekte was realized. K.C.A. Schulz (a member of the Pathology Section) and C. McIntyre in 1948 described its pathology. Another ‘baffling disease’ of sheep at the time was enzootic icterus, and it was only many years later that its pathogenesis and cause were determined.
water which was done by visualizing, under the macroscope, colonies of Ehrlichia ruminantium, the causative organism of the disease, in the endothelial cells of blood vessels in organ sections. This was invariably a very time-consuming process.
Other major contributions made by de 140 Kock and co-workers to our knowledge of livestock diseases in South Africa were investigations into the lesions and other aspects of two infectious diseases. One of these, reported in 1940, concerned an acute infectious disease of pigs which subsequently became known as African swine fever. They considered it quite likely that it might be maintained in warthogs in the northern Transvaal (now Limpopo) Province. The other was a disease, in- vestigated in 1934, which they referred
to as bluetongue of cattle or the so-called
mouth disease. This disease was probably the same as that in cattle which was studied at the Institute by B.J.H. Barnard et al. in 1997 caused by a reovirus and is known as epizootic haemorrhagic disease.
In 1928 W. Steck, a veterinary pathologist from Switzerland who had arrived in South Africa in 1920, recorded a compo- site picture of the macroscopic and microscopic pathology of heartwater based on the post-mortem examination of 228 cases. One difficulty at that time from the pathologist’s viewpoint was the making of a definitive diagnosis of heart-
C. (Cecil) Jackson,
who had joined the Pathology Section soon after he had graduated in 1929, described in 1931 a technique in which he succeeded, with great regularity, in demonstrating E. ruminantium in stained smears made from scrapings of the vascular endothelium of large blood vessels such as the posterior vena cava and jugular vein. This greatly facilitated the diagnosis of the disease.
Steck’s work, from the pathology view- point, was followed up many years later when three members of the pathology section, J.G. (Pine) Pienaar, P.A. (Piet) Basson and J.L. de B van der Merwe in 1966
“Another ‘baffling disease’ of sheep at the time was enzootic icterus, and it was only many years later that its pathogenesis and cause were determined.”
pseudo foot and
described the electron microscopic neuropathological changes of the disease for the first time. This was augmented in 1970 by Pienaar’s electron microscopic study of E. ruminantium in endothelial cells of the vertebrate host. L. (Leon) Prozesky, also of the Pathology Section, followed the footsteps of his predecessors in the section as far as his interest in heartwater was concerned. Working with others in 1985 the pathology of experimental cases of the disease in mice as well as in sheep and goats caused by two different strains of the organism, respectively, was described. This was followed in 1986 by an in vitro study of the ultrastructure of E. ruminantium.
PART 3
History of Individual Disciplines
1908-2008
Years