Black thyroid: a pitfall for aspiration cytology.

Black thyroid discoloration following long-standing use of minocycline has been reported. Morphologic findings of aspiration cytology of these lesions was first reported from The Ohio State University. This abstract describes a second case of black thyroid that was preceded by aspiration cytology. In both cases, thyroidectomies were performed based on "indeterminate" fine-needle aspiration cytology (FNAC). Degenerative changes in follicular epithelial cells in black thyroid causes nuclear hyperchromasia and chromatin clumping, which may be mistaken for neoplasia. Pigment present in follicular epithelial cells and macrophages may be obscured by pigments with similar microscopic appearances, such as hemosiderin. A clinical history of the chronic use of a tetracycline derivative should alert the pathologist to the possibility of black thyroid. Diagnosis may be made by applying special stains on the cell block. The pigment stains with Melanin stain (Fontana) and bleaches with potassium permanganate. In the light of increasing use of FNAC of the thyroid gland and the large number of patients who received tetracycline therapy in the last two decades, it is likely that some practicing cytopathologists may experience this pitfall.

Necrosis of a Hürthle cell tumor of the thyroid following fine needle aspiration. Case report and literature review.

A Hürthle cell tumor of the thyroid gland resected ten days after fine needle aspiration (FNA) showed extensive necrosis accompanied by a small area of hemorrhage. Although no vascular thrombosis was noted in the histologic specimen, it is possible that the necrosis was the result of compromised vascular supply due to the FNA.

Studies on salmonellosis in the house mouse, Mus musculus.

Salmonellae were isolated from the faeces from 17 of 170 (10%) wild house mice. Salmonella typhimurium was isolated from 10, S. typhimurium, var. Copenhagen from 2, S. thompson from 1, and S. muenchen from 4. It was concluded that house mice could be a reservoir of infection and play an important role in human and animal salmonellosis.

Studies on concurrent salmonellosis in dogs and man.

Eight positive Salmonella cultures were obtained from 8 of 314 family dogs in Tehran. Attempts to isolate Salmonella organisms from the owners of the Salmonella infected dogs were successful only in one of eight instances. The Salmonella serotype isolated from the owner was the same as that from his pet dog.

Salmonellosis in apparently healthy dogs.

When rectal swabs were examined from 672 dogs in Tehran, Iran, 52 (7-7 per cent) yielded Salmonellae of 20 different serotypes. The 672 dogs examined comprised 472 household pets, 181 kennel dogs and 19 strays. Tehy showed an incidence of 4-4 per cent, 15-5 per cent and 15-8 per cent respectively.

Purpura hyperglobulinemica (Waldenstrom).

A case of hyperglobulinemic purpura of Waldenstrom with involvement of trunk and arms of 10 years duration has been presented. The patient had mild anemia, hepatosplenomegaly, positive rheumatoid factor and no evidence of immonological abnormalities associated for with systemic lupus erythematosus. A brief review of clinical manifestation and pathogenesis is cited.

Chromosomal synthesis of staphylococcal exfoliative toxin.

Tox-+ staphylococcal strains, as opposed to Tox-minus strains, produce epidermal exfoliation within 18 h after direct subcutaneous or intraperitoneal injection into newborn mice. The extracellular product responsible for exfoliation is termed exfoliative toxin (ET). When culture supernatant fluid from the plasmid-cured Tox-minus substrains UT 0100 or UT 0111 or from six naturally occurring phage group 2 Tox-minus strains was concentrated 20-fold and inoculated into newborn mice, ET activity could be detected. The Tox-minus, cured derivatives produced ET at levels which were 32 minus and 64-fold lower than the amounts made by their Tox-+ parent strains. Since these Tox-minus, cured substrains contained no plasmid deoxyribonucleic acid, it was postulated that the product possessing ET activity in strains UT 0100 and UT 0111 was made by chromosomal genes. This product has been isolated and purified from strain UT 0100 and appears as two faint bands after electrophoresis on polyacrylamide gels and corresponds in position to a heavy band of ET isolated from the Tox-+ strain UT 0007.

Interaction of staphylococcal exfoliative toxin with concanavalin A.

Treatment of mouse embryo fibroblasts (MEF) grown in vitro with purified staphylococcal exfoliative toxin (ET) increased the concanavalin A (Con A) agglutinability of MEF 3.5-fold over control cells. Possible explanations for this phenomenon were investigated. ET lacked proteolytic activity on denatured casein. Con A, however, was found to interact directly with ET as evidenced by the formation of precipitation in an agar gel diffusion plate and in increased turbidity in solution. This interaction was inhibited by alpha-methyl-d-glucopyranoside. The ability of Con A to precipitate with ET suggests that the toxin contains a carbohydrate component and that the carbohydrate associated with ET is branched rather than linear. An analysis of a purified preparation of ET indicated the presence of 9% carbohydrate and no lipid.