Renal artery occlusion and infarction with Sotradecol

Sodium tetradecyl sulfate 3% (Sotradecol) was perfused into a proximally obstructed renal artery in ten random-source adult dogs. In all animals, the intra-arterial injections of Sotradecol produced immediate thrombosis of the renal arteries. Angiographic studies, lasting up to ten weeks, on eight dogs demonstrated persistent occlusion. In one dog, unintentional thrombosis occurred in the opposite renal artery due to reflux of Sotradecol. Histopathologic studies showed total obliteration of the renal arteries through organized thrombosis, intimal sclerosis, and luminal collapse. In all dogs, the kidneys were not visible, and diffuse renal infarction was confirmed by histologic studies of five dogs.

Spontaneous and experimental infections of Xenopus laevis with Chlamydia psittaci

Chlamydial infection was suspected when widespread pyogranulomatous inflammation and large basophilic intracytoplasmic inclusion bodies were evident histopathologically in African clawed frogs (Xenopus laevis) dying of a spontaneous disease of high morbidity and mortality. Organism morphology was determined by electron microscopy of infected hepatic sinusoidal lining cells, and it was characteristic of the unique developmental cycle of a chlamydial agent. Isolation and speciation of the organism was achieved in a McCoy cell culture system. The infected cells were inoculated into disease-free frogs reproducing the disease.

Acute gastric dilatation in nonhuman primates: review and case studies

Acute gastric dilatation occurs sporadically in laboratory-housed nonhuman primates. Clinical histories often include chronic drug administration, food restriction, accidental overfeeding, and prior anesthesia. Monkeys may be found dead or may have clinical signs of colic, abdominal distention, and dyspnea. Death in untreated cases is due to impaired venous return and cardiopulmonary failure. Gastric distention with fermented gaseous ingesta and congestion of the abdominal viscera are the predominant lesions. The cause of acute gastric dilatation is unknown, but it probably is multifactorial. Two principal factors seem to be intragastric fermentation associated with Clostridium perfringens, and abnormal gastric function.

Acute gastric dilatation in nonhuman primates: review and case studies

Acute gastric dilatation occurs sporadically in laboratory-housed nonhuman primates. Clinical histories often include chronic drug administration, food restriction, accidental overfeeding, and prior anesthesia. Monkeys may be found dead or may have clinical signs of colic, abdominal distention, and dyspnea. Death in untreated cases is due to impaired venous return and cardiopulmonary failure. Gastric distention with fermented gaseous ingesta and congestion of the abdominal viscera are the predominant lesions. The cause of acute gastric dilatation is unknown, but it probably is multifactorial. Two principal factors seem to be intragastric fermentation associated with Clostridium perfringens, and abnormal gastric function.

Age-associated lesions in barrier-reared male Sprague-Dawley rats: a comparison between Hap: (SD) and Crl:COBS[R]CD[R](SD) stocks

Age-associated lesions were characterized in two outbred stocks of barrier-reared male Sprague-Dawley rats. Seventy-two virgin Hap:(SD) between 6-29 months of age and 113 retired breeder Crl:COBS[R]CD[R]CDR(SD) between 12-38 months of age were evaluated for the presence of lesions in all major organ systems. Rats of both stocks developed a spectrum of neoplastic, inflammatory and degenerative diseases with highest prevalence in the oldest age groups. In general, the shorter-lived Hap:(SD) rats had greater incidences and severity of lesions when compared to Crl:COBS[R]CD[R]SD of similar ages. Many of these differences were not apparent when the two stocks were compared over their respective life spans. The study provides baseline pathology data relevant to the use of these rats in gerontologic research.

Accelerated appearance of neoplasms in female NZB/NZW mice treated with high-dose cyclophosphamide

Prolonged immunosuppressive therapy with cyclophosphamide increases the prevalence of neoplasms in NZB/NZW mice, an animal model of systemic lupus erythematosus. The current study was designed to compare the oncogenic properties of high dose cyclophosphamide with a low dose therapeutic regimen. Female NZB/NZW mice received life-long therapy with "high dose" cyclophosphamide, 16 mg/kg/day, or "low-dose" cyclophosphamide, 5.7 mg/kg/day; control mice received saline. High dose therapy clearly accelerated appearance of neoplasms. Seventeen of 19 mice treated with high-dose cyclophosphamide developed neoplasms at the mean age of 61 weeks. Fifty-seven percent of these tumors were mammary carcinomas. Neoplasms appeared in all mice treated with low dose; mean longevity in this treatment group was 80 weeks (compared to high dose treated mice, P less than 0.001). Carcinomas, pulmonary adenomas, and lymphomas were the most common tumors in mice receiving low dose therapy. Positive tests for ANA were suppressed in high dose treated mice. AntiDNA antibody levels and glomerulonephritis were decreased significantly in both groups of cyclophosphamide-treated mice compared to controls. It was concluded that the high daily dose of immunosuppressive drug was related to early oncogenesis in autoimmune NZB/NZW mice.

Effects of outboard motor exhaust emissions on goldfish (Carassius auratus)

Goldfish (Carassius auratus) were exposed to outboard exhaust products in water or to toluene (a constituent of outboard motor exhaust water) via a continuous flow bioassay dosing apparatus. Various physiologic and pathologic changes were noted. In the blood a consistent decrease (p less than 0.05) in the partial pressure of oxygen, a significant increase (p less than 0.05) in the partial pressures of carbon dioxide, and significant decreases (p less than 0.05) in pH and oxygen saturation were found in many of the blood gas experiments. Laboratory experiments also indicated that these fish are capable of metabolizing toluene to hippuric acid (p less than 0.05). Exposure up to 30 days to these exhaust products produced gross and microscopic lesions in the high-, intermediate-, and low-dose fish. Grossly, livers were smaller and pale; intestines were empty of ingesta and feces; and gills were coated excessively with mucus. Microscopically, the livers of the exposed fish had a decreased cytoplasmic:nuclear ratio, gill filaments were fused, and some kidneys had tubular vacuolization.

Age-associated pathological changes in male rats

The selection of rats for aging research and the interpretation of experimental results require knowledge of spontaneous age-associated lesions in specific stocks and strains. We have compared selected age-associated pathological changes, as determined by postmortem examination of 113 outbred Crl:CD(SD)BR male retired breeder rats 12--39 months old, with those reported by others in a group of 122 virgin male 12- to 33-month-old F344 rats, an inbred strain from the same commercial source as the outbred rats. Numerous degenerative, inflammatory, and neoplastic lesions occurred in both groups. The wide prevalence and severity of many of the lesions suggest that they could be the source of significant variability in the results of specific aging studies, by their direct and indirect effect(s) on target organs. The prevalence of spontaneous lesions should be defined for each stock or strain intended for use in aging research by postmortem examination of representative groups of animals at various ages. Antemortem diagnostic screening of old rats may also be useful in culling animals bearing lesions that could add to the variability of experimental results, or in selecting for specific lesions that are of research interest themselves.

Stimulated autoantibody response and increased longevity in NZB/NZW mice treated with cyclophosphamide and tilorone

The experiment described in this report was designed to study the effects of immunostimulatory therapy in cyclophosphamide-treated hybrid New Zealand mice. Autoantibodies, renal histology and neoplasms were studied in seventeen female NZB/NZW mice treated with daily injections of the potent immunosuppressive drug, cyclophosphamide. Results were compared with fifteen female NZB/NZW mice who received both cyclophosphamide and tilorone, an interferon inducer which stimulates the immune system. Fifteen control mice received saline. The controls died with spontaneous arteritis and immune complex glomerulonephritis; their mean age at death was 46 weeks. In the cyclophosphamide group anti-DNA antibodies and renal disease were suppressed. Mean longevity was prolonged significantly to 80 weeks. Two mice died of iatrogenic causes, and the remaining fifteen mice died with neoplasms. Eleven mice had multiple neoplasms; a total of twenty-seven neoplasms appeared. In mice receiving combination therapy, autoantibody responses were not suppressed. Nevertheless, glomerulonephritis was controlled partially and the mean lifespan was prolonged to 82 weeks. Eighteen neoplasms appeared in ten mice in the combination treatment group, and five mice had more than one neoplasm. The appearance of lymphomas was delayed in mice receiving two drugs. It was concluded that concurrent therapy with tilorone stimulated autoantibody production and altered the expected pattern of neoplasia in cyclophosphamide-treated NZB/NZW mice.

Prolonged lifespan and high incidence of neoplasms in NZB/NZW mice treated with hydrocortisone sodium succinate

This study investigated the effects of prolonged corticosteroid therapy on the course of spontaneous autoimmune disease and oncogenesis in NZB/NZW mice, an animal model of systemic lupus erythematosus. Twenty young female NZB/NZW mice were treated until death with low-dose hydrocortisone sodium succinate (3.3 mg/kg/day), and 21 mice received high-dose hydrocortisone (10 mg/kg/day). Fifteen control mice were injected with saline. Long-term therapy with either dose of hydrocortisone effectively prevented renal disease and prolonged lifespans in NZB/NZW mice. Fifty-six percent of low-dose treated animals developed neoplasms, and 38% of mice in this treatment group died with renal disease. Neoplasms caused death in 76% of mice receiving high-dose treatment. Long-term hydrocortisone therapy was associated with a predominance of sarcomas, which appeared in aged mice after a long period of treatment. In earlier studies conducted in this laboratory, cyclophosphamide treatment prolonged life in NZB/NZW mice. Ninety-seven percent of cyclophosphamide-treated mice developed neoplasms; most tumors were lymphomas or carcinomas. It was concluded that neoplasms occur commonly in old NZB/NZW mice with lives prolonged by immunosuppressive or antiinflammatory drugs. Nevertheless, the specific therapeutic agent used in each study influenced the types of neoplasms appearing in treated mice.

Amebiasis in goldfish

Five cases of amebiasis were diagnosed in goldfish (Carassius auratus) from home aquariums and from a laboratory aquarium. Granulomas containing amoebae were in many organs but were most numerous in kidneys. Because there were pseudopods, food vacuoles, vesicular nucleoli and other ultrastructural characteristics of the organisms, we identified the organisms as amoebae. On the basis of mitotic stages it is possible they belong in the family Hartmannellidae.

Myobacteriosis in turtles: cutaneous and hepatosplenic involvement in a Phrynops hilari

Mycobacteriosis in a Phrynops hilari (side-necked turtle) was characterized by multiple caseating granulomas in the liver and spleen; pulmonary involvement did not occur. Granulomatous inflammation and organisms also were present in the skin, suggesting a cutaneous route of entry with hematogenous spread to visceral organs. Review of the four cases of chelonian mycobacteriosis in the literature indicated that pulmonary tubercules and plastral ulcerations are typical manifestations. The Mycobacterium species usually involved is M. chelonei.

Spontaneous malignant histiocytoma with metastasis in a rhesus monkey [Macaca mulatta]

A malignant histiocytoma was observed on the left arm of a recently imported rhesus monkey. Rapid invasion of deep tissues and tumor growth on the face prompted euthanasia. Necropsy revealed additional neoplastic foci in the lungs, diaphragm, intercostal muscles, pericardium and liver. Microscopically the predominant cell type was histiocytic; some cells had a distinct epithelioid appearance and other were spindle-shaped.

Dermatophilosis in the marble lizard (Calotes mystaceus)

Dermatophilus congolensis was isolated from cutaneous hyperkeratotic nodules of two marble lizards. The organism was similar to strains of D congolensis previously characterized as mammalian pathogens. The isolate was experimentally transmitted to other marble lizards and to Spb:(SW)BR mice by subcutaneous inoculation and by topical application after skin scarification.

Animal model of human disease. Ulcerative colitis. Animal model: Ulcerative colitis induced in guinea pigs with degraded carrageenan

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Fever and survival

The significance of fever in response to a bacterial infection has been investigated using the lizard Dipsosaurus dorsalis as an animal model. These lizards develop a fever of about 2 degrees C after injection with the bacterium Aeromonas hydrophila. To determine whether this elevation in body temperature increases the resistance of the host to this infection, as measured by survival, lizards were infected with the live bacteria and placed in a neutral (38 degrees C), low (34 degrees or 36 degrees C), or high (40 degrees or 42 degrees C) ambient temperature. An elevation in temperature following experimental bacterial infection results in a significant increase in host survival.

Simian neonatology. 3. The causes of neonatal mortality

The causes of death were studied in 82 perinatal and neonatal monkeys. Forty-three of the 82 neonatal deaths were caused by inflammatory diseases (mainly pneumonia), intrauterine distress, and trauma. In 28 of the 82 monkeys, a major disease process could not be demonstrated. Intrauterine distress and antepartum death with maceration were commoner causes of death in premature infants; trauma and inflammatory disease occurred more often in mature infants. Forty-nine of the 82 neonatal deaths occurred before the second day of life. During the last 3 weeks of the neonatal period, the majority of deaths were caused by infection.

Simian neonatology. II. Neonatal pathology

Spontaneous gross and microscopic lesions were studied in 82 perinatal and neonatal monkeys of various species. Ninety-seven lesions were found in the body systems examined. The system at greatest risk was the respiratory system (33 lesions), at the least risk, the cardiovascular system (four lesions). Lesions were inflammatory, degenerative, vascular, and of other types, such as intrauterine aspiration and congenital anomalies. Differences in the type and distribution of lesions in the various systems were found between premature and mature infants.