A 90-Day Inhalation Toxicity Study of Raw Shale Oil in Fischer 344 Rats

A 90-Day Inhalation Toxicity Study of Raw Shale Oil in Fischer344 Rats. GORDON T., STROTHER, D. E., CRAMER, D. V., AND GOODE,J. W. (1987). Fundam. Appl. Pharmacol. 9, 287–296. Thepotential health effects of a raw shale oil were evaluated ina 90-day inhalation study in Fischer 344 rats. Groups of 15male and 15 female rats were exposed 6 hr/day, 5 days/week for13 weeks to aerosol concentrations of 0, 56, 120, or 492 mg/m³.In the high-dose group, 10 males and 7 females died prior tothe termination of the study, most within the first 5 weeksof the experiment. A dose-dependent suppression in weight gainwas seen in all of the shale oil-exposed groups. The failureto gain weight was associated with a variety of clinicopathologicabnormalities, including a dose-related decrease in red andwhite blood cells, with lowered plasma protein levels and increasedserum alkaline phosphatase, and with total bilirubin levelsin males. The exposure of the test animals to aerosolized rawshale oil was also associated with inflammatory and hyperplasticlesions in the lungs and upper respiratory tract, atrophy ofthe thyrnus and thymic-dependent portions of the peripherallymphoid system, and bone marrow. These changes demonstratethat inhalation of raw shale oil aerosol can produce major organtoxicity similar to that found after exposure to other unrefinedoil products.     

Vaccination against the cat flea Ctenocephalides felis felis

Non-chemical control of haematophagous parasites is a desirable goal. We report here on the use of concealed antigens from the major digestive organ of the cat-flea as vaccine components. Rabbits were immunized with various antigens from cat flea midguts, and immunoglobulin from these rabbits was fed to cat fleas in an artifical feeding system. Antibody produced against soluble antigens from the midguts of fed fleas was able to kill fleas in this system. Dogs were then immunized with various antigen preparations, and challenged for a week with live fleas. Significantly fewer live fleas were recovered from dogs immunized with fed midgut supernatant, and recovered live female fleas produced significantly fewer eggs. This study indicates the possibility of vaccination as a means of control of flea, and possibly other blood sucking insect populations.     

Chronic Morpholine Exposure of Rats

Chronic Morpholine Exposure of Rats. HARBISON, R. D., MARINO,D. J., CONAWAY, C. C., RUBIN, L. F., AND GANDY, J. (1989). FundamAppl. Toxicol. 12,491–507. The chronic toxicity and carcinogenicpotential of morpholine were evaluated in 60 Sprague-Dawleyrats/sex/group receiving morpholine at mean inhalation exposureconcentrations of 0, 10, 50 and 150 ppm for 6 hr/day, 5 days/week,for 104 weeks. Survival, body weight gains, organ weights, hematology,and clinical chemistries were normal in exposed groups and comparableto those of the control animals. The incidences of palpabletissue masses and of histologically confirmed neoplasia werecomparable among all groups, including the control groups, andwere typical of the strain and age of the rats tested. In-lifeclinical examinations revealed increased incidences of irritationaround the eyes and nares, chromadacryorrhea, and urine stainson the fur, predominately in high-dose animals. Morpholine exposurewas associated with corneal irritation seen by ophthalmoscopicexamination and confirmed microscopically as keratitis limitedto the highest exposure group. Irritation of the maxillary andnasoturbinates as indicated by infiltration of neutrophils,focal squamous metaplasia of the turbinate epithelium, and necrosisof the turbinate bone was observed in high-dose animals. Therefore,chronic exposure of rats to morpholine for 2 years at concentrationsof 150 ppm or less revealed no carcinogenic potential or chronicsystemic toxicity. Consistent with its known irritating properties,morpholine produced only local irritation, which was limitedalmost exclusively to high-dose animals.     

Carcinoma of the breast with metaplasia to chondrosarcoma: a light and electron microscopic study

Two carcinomas of the breast containing large areas of sarcomatous tissue were studied by light and electron microscopy. In one of these, the sarcomatous element was frankly cartilaginous and in the other, predominantly myxoid but with small cartilaginous-looking foci. By light microscopy, a highly suggestive metaplastic transition could be traced from cells within the epithelial nests to those within the sarcomatous lobules. Ultrastructurally, cells in the former region showed epithelial characteristics and those in the latter region, mesenchymal and/or cartilaginous features. The carcinomatous cells contained desmosomes and formed intercellular spaces lined by microvilli; a few cells showed prominent profiles of rough endoplasmic reticulum. In the first case, the cells in the immediate vicinity of the epithelial nests and those in the fully developed cartilaginous regions showed a progressive dilatation of their endoplasmic reticulum to form large sac-like structures filled with a finely granular and floccular material. The intercellular matrix was electron lucent and contained scattered dense particles, fibrillo-granular material and collagen fibres. Condensation of this material at some distance from the cell resulted in the formation of lacunae. In the second case, the cells in the myxoid areas also showed prominent dilatation of endoplasmic reticulum.     

HYPERTHYROIDISM DUE TO A THYROTROPHIN-SECRETING MICROADENOMA

We report a 63-year-old female with a TSH-secreting pituitary adenoma causing hyperthyroidism. This case is apparently unique, and challenges the present concept of dividing patients with inappropriate TSH secretion into tumour and non-tumour groups on the basis of conventional pituitary fossa radiology.     

Coeliac disease,epilepsy, and cerebral calcifications: association with TG6 autoantibodies

A 4‐year‐old boy presented with occipital seizures but normal initial neuroimaging and proved refractory to antiepileptic medications. On repeat neuroimaging after 1 year, he had developed bi‐occipital calcification and was then found to have positive coeliac serology. He was diagnosed with coeliac disease, epilepsy, and cerebral calcifications (CEC) and became seizure free after starting the gluten‐free diet. Positive antibody binding to neurons and glia was demonstrated on indirect immunofluorescence. High levels of immunoglobulin‐A directed against transglutaminase isoenzyme 6 (TG6) were found in the patient’s serum. The positive response to the diet, TG6 antibodies, and neuronal antibody binding suggest that CEC might be autoimmune in nature, as in other extra‐intestinal manifestations of gluten‐related diseases, such as gluten ataxia.     

Splenic aspiration biopsy in the dog

A method of partial marsupialization of the dog spleen which permits repeatedaspiration biopsies of the spleen has been developed. Needle-core or open surgical biopsies may also be carried out on these dogs. The cytologic picture foundin material from aspiration biopsies of dog spleens is described. Percutaneoussplenic-portal venography or injection into the portal circulation may also becarried out by injecting directly into the marsupialized spleen.

Submitted on December 29, 1954 Accepted on February 14, 1955