The Department of Pathology was the first scientific unit established at the German Primate Center (DPZ) already in its planning phase. At that early time the planning of administrative duties was also necessary, including the financial framework of the laboratory equipment of the then-envisioned three departments of pathology, virology and physiology, in order to get the DPZ off the ground. Otherwise the functions of the Department of Pathology were both service duties and scientific evaluations. The service functions after the establishment of the DPZ included pathological, bacteriological and parasitological examinations/surveys and the veterinary care of nonhuman primates at the DPZ and other primate colonies. On an international level its service functions were reflected by the collaboration within the Office International de Epizooties (OIE, Paris) (Dollinger et al., 1996) and the Infectious Diseases Working Group of the European Association of Zoo and Wildlife Veterinarians, and the establishment of a bacteriological laboratory in Iquitos, Peru, at the request of the Pan American Health Organization.
Parallel to those administrative and service duties to the DPZ and to international communities, the different scientific activities started, which in a pathology department always are a combination of service and research. They are documented by a total of almost 120 publications, including 3 doctoral theses and 116 publications by the author from 1973 to 1999; the most important ones are summarized in the following examples.
This white-matter disorder observed in 16 captive born chimpanzees of different origins, ranging in age from 3.5 months to 21 years, is morphologically similar to periventricular leukomalacia of man. Globular acid glycosaminoglycans and sparse proteins accumulated particularly in, but not restricted to, the Virchow–Robin spaces in the prosencephalon, the thalamus adjacent to the internal capsule, the lentiform nucleus and rarely the caudal nucleus (Brack, 1973).
A 16-year-old hand-raised female Bornean orangutan came down with a
vesicular dermatosis of the entire trunk and all extremities, followed by
severe pruritus, alopecia, depression, general weakness and totally
suppressed sexual cycles. Euthanasia for humane reasons was considered
because the condition seemed untreatable after the diagnosis of an infected
eczema by a local laboratory and failure of all treatments. In a last step to
avoid the loss of that genetically valuable animal (the Bornean variety of
the orangutan is under extreme pressure of extinction), a skin biopsy was
forwarded to the DPZ. At histopathology the characteristic signs of a
cutaneous
Herpesvius SA8 belongs to the epitheliotropic Alphaherpesvirinae, a group also including herpesviruses hominis types 1 and 2 and B virus (Cercopithecine herpesvirus 1). All alphaherpesviruses have a tendency to infect also the brain, especially in foreign hosts. SA8 normally causes urogenital infections in adult baboons, and has possibly caused fatal pneumonias in numerous newborn baboons at the Southwest Foundation for Research and Education, San Antonio, Texas, USA.
The question was whether they represented intrauterine (diaplacental) or postnatal infections. Therefore both routes were experimentally simulated by intravenous versus intratracheal infections of neonatal, 6-month-old and 1-year-old baboons. The results were that intravenous inoculation of SA8 caused only minor, transient pulmonary interstitial responses, whereas intratracheal infections induced fatal necrotizing pneumonias as observed in the spontaneous cases.
Additional examinations concentrated on the central nervous system of the experimentally infected animals. Intravenous infections caused minor diffuse meningoencephalitis in all parts of the brains; intratracheal infections, in contrast, induced inclusion body encephalitis limited to the vagal root, such as the medullary bundles of the N. vagus within the medulla oblongata, the substantia reticularis myelencephali, vagal dorsal nucleus, nucleus of the solitary tract, and in two animals within the spinal tract of the trigeminal nerve. The caudal limits were the decussation of the lateral corticospinal tract; the anterior borders were the basal parts of the di- and telencephalon. The lesions never reached the cortex (Brack et al., 1981a, b); altogether the results pointed to postnatal infections as the natural route. The outbreak was finally stopped by acyclovir treatment.
A naturally born and raised rhesus monkey infant developed behavioral abnormalities and visual impairment. At 1.5 years of age it was decided to euthanize the animal for humane reasons. At necropsy and histopathology both cerebral parietal lobes were atrophic, with the sunken areas reaching anteriorly from the central sulci to the lunate sulci at the posterior end, medially to the angulate gyrus and ventrolaterally going halfway down the temporal lobes, thus encompassing the brain areas 5 and 7, and parts of areas 18 and 22. The optic chiasm, however, was unaffected. The causes of that peculiar disease remained unknown, but the report of several cases of “neonatal blindness” in the colony of origin at Cayo Santiago makes a viral etiology possible, since the Cayo Santiago colony is latently infected with Cercopithecine herpesvirus 1 (B virus).
This interesting case exemplifies the rapid expansion of the fox tapeworm.
For example,
The route of infection of the monkeys at the DPZ can only be speculated. Because physical contact with foxes or fox feces was virtually impossible in the reported case, the most likely way was through contaminated branches or foliage taken from the nearby forest for environmental enrichment of the enclosures.
Three out of 10 wanderoos (lion-tailed macaques) at the Rheine Zoo, Rheine,
Germany, died within 2 days peracutely or were found dead; the last one, a young-adult
female, was forwarded to the DPZ for determination of the cause of death. The
necropsy findings were hampered by autolysis of the carcass, but bacteriology revealed a
septicaemia by
Distribution of herpetic lesions in the brains of newborn baboons following intratracheal SA8 infections.
Botryomycosis is a Hoeppli phenomenon rarely observed in the skin of man and
mostly caused by
In a
One of the most frequent lesions seen at histopathology of captive marmosets and tamarins was alterations of the renal corpuscles. The lesions reached from mesangial hyperplasia beginning at the mesangial hilus, they extended peripherally to finally affecting the entire mesangial tree, leading to corpuscular obsolescence after contact of the glomerular tufts to the Bowman's capsule. Immunohistochemistry demonstrated the accumulation of mainly IgM complexes, sometimes also IgA complexes in the extended mesangia. Ultrastructurally the immunocomplexes appeared as electron-dense granules within the mesangial channels, accompanied by collagen IV-fibers within the mesangial cytoplasm,both of which compressed the mesangial channels. A peculiar feature of only callitrichid mesangia has been the protrusion of the mesangial cellular matrix through endothelial fenestrations, considered to be signs of enhanced activity (Brack, 1983, 1990; Brack and Weber, 1995).
A so-far-unknown new bacterium has been isolated at necropsy from the heart
of a
A long-standing breeding colony of
Advanced mesangial proliferation in callitrichid IgM nephropathy
(arrow). Movat, 250
Granulomatous lung lesions were registered in 65 tree shrews older than 3 months. They were present mostly around vascular structures primarily at the ventral margins of the lung lobes and resembled pulmonary histiocytosis of rats. The granulomas contained fibrous material without birefringence, as determined by both polarization and electron microscopy, but consisted of calcium according to energy-dispersive X-ray microanalysis. Faulty filtration in the ventilation system during the construction phase of the building was suspected to be the cause.
In 8 out of 524 tree shrews of unknown exposure to the calcium fibers, lung tumors developed: 4 bronchiolar tubular adenomas, 2 bronchial adenocarcinomas and 2 squamous-cell carcinomas.
The rarely described exoparasite
Tree shrews like prosimians and certain euprimates possess a small, ill-defined cutaneous scent-marking gland at the lower ventral neck, consisting primarily of sebaceous gland tissues. In five adult males, that gland developed sebaceous adenocarcinomas; in one a papilliform adenoma of the apocrine tissues compartment was found instead. The adenocarcinomas tended to invade adjacent blood vessels; one had metastasized into the regional lymph nodes, thoracic muscles and the lungs (Brack, 1991).
Testicular tumors are generally rare in nonhuman primates, including prosimians, but testicular alterations and finally tumors occurred frequently in the tree shrews of the DPZ. The testicular lesions in the tree shrews varied from stress-related hypospermatogenesis to testicular atrophy to testicular tumors. In total 1 hamartoma, 1 seminoma and 12 Leydig cell tumors were found, all preferring the left testicle and developing only in animals beyond 4 years of age (Brack, 1988; Brack and Fuchs, 2000).
To complete the scientific achievements of the Department of Pathology from 1973 to 1999m the following publications should be mentioned:
Brack, M.: Morphological and epidemiological aspects of simian
herpesvirus infections, 1977. Brack, M.: Obligate and facultative pathogenic germs of primates, with
supplement: classification of primates, 1980. Brack, M. and Niemitz, C.: The parasites of wild-caught tarsiers
( Brack, M.: Agents transmissible from simians to man, 1987. Brack, M., Göltenboth, R., and Rietschel, W.: “Primaten”, 1995.
That very abbreviated list of scientific activities does not contain the many publications on problems also reported by others, e.g., atherosclerosis and stroke in chimpanzees, mammary carcinomas in tree shrews, colonic signet-ring carcinomas in cotton-top tamarins, other tumors or parasitic or bacterial diseases already known to occur in nonhuman primates.
Not listed here are also the worldwide advice and assistance to zoological gardens, institutes or governments without publicity, but they have all contributed to the national and international reputation of the Department of Pathology and the DPZ in general.