Susceptibility of laboratory and domestic animals to experimental infection with Potiskum virus

The biological characteristics of Potiskum virus, a hitherto undescribed virus isolated in Nigeria from the liver of a giant rat (Cricetomys gambianus), were studied by experimental infections of laboratory and domestic animals. The laboratory animal hosts used included mice, rats, rabbits and chicks. Suckling and weaning mice succumbed to fatal infection when infected with Potiskum virus by intracerebral or intraperitoneal routes. Infected mice had high titres of virus and mild histopathological lesions which were confined to the brain. Chicks also developed a fatal disease following subcutaneous or oral infections with Potiskum virus. In contrast, albino rats and rabbits failed to succumb to overt disease by subcutaneous and intraperitoneal routes of inoculation. Albino rats did not develop antibody but rabbits developed haemagglutination inhibiting, neutralising and complement fixing antibodies.     

A new artificial respirator suited for perfusion fixation of tissues in small laboratory animals (author's transl)]

A new, simple and inexpensive instrument, that proved to be useful for perfusion fixation of small laboratory animals, was devised.     

A respiratory pump for small animals (author's transl)]

A respiratory pump is described which is controlled by compressed air and contains no mechanical moving parts, neither a motor nor a piston. It can function on a self-adjusting rhythm or can be regulated externally (for example by the discharge of a phrenic nerve).     

Present status of experimental animals in Japan (author's transl)]

The movement for modernization of experimental animals in Japan started around 1950. Since that time, a quarter of a century has passed. This article outlines the present status of experimental animals in Japan and makes comparisons with various other countries. Number of animals used: According to three surveys performed in the past (1956, 1960 and 1970), the numbers used of many species are increasing (Table 1). However, it can not be said simply that the numbers are increasing every year. Taking the United States where surveys are performed every year as an example (Table 3), it is evident that the peaks for use of some species are past (the same tendencies were seen in India and Sweden which have conducted more than four surveys in the past (Table 4). The same tendencies would probably also be seen in Japan if surveys were conducted annually. Quality of animals: It is easy to procure genetically and microbiologically controlled rats and mice. However, investigations into the establishment, production and supply of other species of such high quality are insufficient. This situation is almost the same as that in European countries. Miscellaneous: The present status of other items related to experimental animals is as follows: Facilities and equipment: Higher level facilities were first provided in companies, followed by testing and research institutes. At present, medical universities are providing such facilities. Feed: Pellet type diets are widely used for the various species. Care and management: In April, 1974, "The Law for the Protection and Control of Animals" came into force. This law includes regulations concerning animal experimentation but investigations concerning these standards have just begun. Training of technicians and specialists: The Japan Experimental Animal Research Association provides a correspondence course, tests and recognition for technicians. About 10 veterinary colleges have undergraduate or postgraduate courses for the training of specialists but these are elective except in two or three cases.     

Susceptibility of four species of small rodents to encephalomyocarditis (EMC) virus infection

The D variant of encephalomyocarditis virus (10(1)-10(5) PFU/head) was intraperitoneally inoculated into 4 species of small rodents, rats, mice, Syrian hamsters, and Mongolian gerbils, and the susceptibility of these animals to EMC virus was examined virologically and histopathologically 3 days after infection. Viral replication was detected in the brain (mice), in the heart (mice and gerbils), and in the pancreas (mice, hamsters, and gerbils). No viral replication was detected in rats. Histopathological changes were seen in the brain (mice and hamsters), in the heart (mice and gerbils), and in the pancreas (mice, hamsters, and gerbils). No histopathological changes were seen in rats. The present results suggest that it may be quite possible to produce EMC virus-induced diabetes mellitus not only in mice but also in hamsters and gerbils.     

Pathologic anatomy of pneumonia caused by Legionella: on the materials of outbreak in town Verkhnyaya Pyshma

Data on postmortem examination of five patients deceased during Legionnaires' outbreak in town Verkhnyaya Pyshma are presented in the article. Feature of course of the disease was severe affection of the lungs with development of toxic shock. Pathomorphological picture in lungs was characterized by polymorphism, presence of shock reaction and ventilator-associated pneumonia (atelectases, distelectases, tracheobronchitis). In autopsy material from four fatal cases Legionella pneumophila serogroup 1 was detected. Causative agent of pneumonia was not determined in one fatal case although comparison of clinical and morphological characteristics of this case with other four cases as well as detection of Gram-negative bacillus in alveolar macrophages allowed to consider this case of pneumonia as caused by Legionella. In studied fatal cases postmortem diagnoses were ascertained in which main disease was bilateral pneumonia caused by Legionella pneumophila serogroup 1 complicated by toxic shock.