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Guinea pigs inoculated with the live M-44 vaccine strain of Coxiella burnetii were examined grossly and microscopically for the presence of Q fever-related lesions. Mild myocarditis was observed in 38% of the infected animals but in none of the control animals. Livers showed significant incidence of hepatitis, necrosis, and granuloma formation, especially during the first eight days of the infection. A much lower incidence of splenitis was also found but was considered to be of borderline significance. Generally, lesions were mild in nature, and none seemed to endanger the life of the animal or to cause observable distress.

A large, rapidly growing subcutaneous fibrosarcoma was observed on the head of an aged male white-tailed deer (Odocoileus virginianus) from Frederick County, Maryland. Although there was no evidence of distant metastasis, the large neoplastic mass had extensively invaded the osseous supraorbital process, and had several small satellite nodules nearby.

Abstract. Tyzzer's disease (bacillus piliformis infection) was diagnosed in a young guinea pig killed because of diarrhea and poor condition. There was necrosis and inflammation of the colon, cecum and ileum. Typical B . piliformis were in intestinal epithelial cells. Spirochetes were in large numbers in intestinal crypts and were often adjacent to the intracellular B . pilifbrrnis. Extracellular B . piliformis occasionally were surrounded by spirochetes.

A mass in the trachea of a dog partially obstructed the laryngeal inlet, caused respiratory distress, and was found to be composed of amyloid subdivided by a granulomatous stroma.

Telone II (technical grade, 1,3-dichloropropene), a soil fumigant, was evaluated in chronic toxicology/carcinogenicity studies using Fischer-344 (F344) rats and B6C3F1 mice of both sexes. Doses administered were 0, 25, or 50 mg/kg to rats and 0, 50, or 100 mg/kg to mice. Telone II was given in corn oil by gavage 3 times per week for 104 wk. Ancillary studies were conducted to determine time-related effects, in which dose groups containing 5 male and 5 females rats were killed after receiving Telone II for 9, 16, 21, 24, or 27 mo. The primary organs affected were the forestomach (rats and mice), urinary bladder (mice), lung (mice), and liver (rats). Compound-related non-neoplastic lesions included basal-cell or epithelial hyperplasia of the forestomach (rats and mice), epithelial hyperplasia of the urinary bladder (mice), and hydronephrosis (mice). Neoplastic lesions associated with administration of Telone II included squamous-cell papillomas of the forestomach (male and female rats, female mice), squamous-cell carcinomas of the forestomach (Male rats, female mice), transitional-cell carcinomas of the urinary bladder (female mice), alveolar/bronchiolar adenomas (female mice), and neoplastic nodules of the liver (male rats). Although cis- and trans-1,3-dichloropropene are the principal components of Telone II, the presence of 1% epichlorohydrin, a direct-acting mutagen and carcinogen added as stabilizer, may have influenced the development of forestomach lesions. The results of the ancillary studies supported the findings of the carcinogenesis studies and demonstrated the time-dependent development of lesions in the forestomach (basal-cell hyperplasia and squamous-cell papilloma). Under the conditions of these gavage studies, Telone II was shown to be carcinogenic in male and female F344 rats and female B6C3F1 mice. Although the study in male B6C3F1 mice was considered inadequate because of the low survival resulting from suppurative inflammation of the heart (myocarditis) in the control group, there was some indication of Telone II-related increases of transitional-cell carcinomas of the urinary bladder, squamous-cell papillomas of the forestomach, and alveolar/bronchiolar adenomas and carcinomas of the lung.

Abstract. Rhesus monkeys were inoculated intravenously or intraperitoneally with various numbers of Rickettsia rickettsii. Monkeys that were given more than lo4 organisms intravenously died on days 3-6 after inoculation, whereas those given less than los intravenously or more than lo4 intraperitoneally died on day 7 or later. There was no significant difference in incidence of lesions between the early-and late-death groups. Vasculitis and thrombosis occurred most frequently in the nares, pinna of the ear, scrota1 skin, and testicle. Adrenal cortical necrosis was caused by capillary thrombosis. Rickettsiae, estimated by plaque formation in culture, were most numerous in the lung and spleen.The morphologic features of naturally occurring Rocky Mountain spotted fever in man, and the experimentally induced disease in monkeys and guinea pigs have been described [2-4,8, 141. The fundamental lesion is inflammation of the small blood vessels. The present study was undertaken to determine the incidence and type of lesions in a group of Rhesus monkeys dying at various intervals after intravenous or intraperitoneal inoculation of Rickettsia rickettsii. Immunofluorescence studies and direct plaquing of organ homogenates were done to correlate lesions with presence of rickettsiae. Materials and MethodsMethods for propagation of R. rickettsii in yolk sacs of embryonated chicken eggs are described elsewhere [I I]. Seed stock was stored at -70°C as 50% yolk sac suspension in sucrose-phosphate-glutamate buffer [6]. Methods for propagation in duck embryo cells have been described previously [7]. Live rickettsiae were quantitated by plaque assay as described [12].