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Biomedical subjects

B Sina

Publications and source records attributed to B Sina.

At least 19 recordsLinked to original sources

Cutaneous eruptions from suramin. A clinical and histopathologic study of 60 patients.

BACKGROUND AND DESIGN: During a trial of suramin for advanced solid tumors, a high rate of cutaneous adverse reactions was observed. We present a prospective study, describing the clinical, histopathologic, histochemical, and immunochemical findings of the cutaneous reactions observed in 60 patients treated with suramin. RESULTS: Forty-nine (82%) of the 60 patients studied experienced at least one cutaneous reaction attributable to suramin therapy. Although morbilliform reactions predominated, a wide variety of eruptions was observed. Most reactions occurred within the first 24 hours of therapy and were self-limited despite continued drug infusion. Distinctive cutaneous findings included scaling erythematous papules (suramin keratoses) and a predilection of many eruptions for previously sun-exposed areas. Six patients experienced severe cutaneous reactions, but no patient permanently withdrew from therapy because of cutaneous toxic reactions. Common histopathologic findings included hyperkeratosis, parakeratosis, spongiosis, acanthosis, exocytosis, apoptosis, a perivascular lymphohistiocytic infiltrate, upper dermal edema, and increased dermal mucin. Staining with S100 antigen was markedly positive in several specimens. Only trace amounts of suramin were detected in skin samples tested with high-pressure liquid chromatography. CONCLUSIONS: The incidence of cutaneous toxic reactions from suramin greatly exceeds that seen with other medications. A wide spectrum of skin manifestations were observed, including suramin keratoses and UV recall, although serious reactions were infrequent. Cutaneous toxic reactions neither predicted nor correlated with other toxic reactions from suramin. Suramin may soon become more widely used; practitioners should be aware of the high incidence and wide spectrum of cutaneous toxic reactions to this drug.

Adult

Probing behaviour and sporozoite delivery by Anopheles stephensi infected with Plasmodium berghei.

We observed that Plasmodium berghei sporozoite-infected Anopheles stephensi was not impaired in its ability to locate blood on a host. When probing rats, infected mosquitoes took as long as non-infected mosquitoes to locate blood. Contrary to previous suggestions, infective mosquitoes delivered sporozoites into mineral oil even after extensively probing a vertebrate host. We observed that, in mosquitoes having probed a host, both the mean number of sporozoites ejected over 3 min into oil (35.9 v. 31.7 sporozoites) and the proportion of mosquitoes delivering sporozoites (60% v. 50%) were similar to mosquitoes not having probed. We then developed a model of sporozoite delivery, taking into account observations that sporozoites are clumped in the lumen of the glands as well as upon delivery, and that output is uneven and inconsistent. We conclude that clumping optimizes transmission, if a threshold of infection exists and the mean number of sporozoites per clump is greater than the threshold.

Animals

Fibrous mastocytoma in a patient with generalized cutaneous mastocytosis.

A 57-year-old woman with cutaneous mastocytosis of 23 years duration developed a hyperpigmented abdominal plaque composed of confluent indurated papules that enlarged for a period of 1 year to 12 x 8 cm. Biopsy showed dermal infiltration by closely packed spindle-shaped mast cells, fibroblasts, collagen, and scattered lymphocytes, predominantly T-suppressor cells. Electron microscopy showed close contact between mast cells, fibroblasts, and lymphocytes. Piecemeal mast cell degranulation and extrusion of mast cell granules was seen, with rare mast cell granules in fibroblasts, and collagen fibers in peripheral and perinuclear endoplasmic reticulum of mast cells. the term Fibrous mastocytoma is suggested for this tumor-like dermal fibrosis, possibly induced by lymphokines.

Biopsy

Generalized elastophagocytic granuloma.

The case of an eighty-three-year-old woman with the sudden onset of a generalized pruritic eruption is reported. The skin lesions resembled disseminated subacute lupus erythematosus on clinical examination, but actinic granuloma or annular elastolytic giant cell granuloma was seen in biopsy specimens of the lesions. Our case was differentiated from generalized granuloma annulare by the distinct zoning of elastolysis and the distribution of giant cells.

Aged

Non-CS pre-erythrocytic protective antigens.

Three novel non-CS antigens have been identified on P. falciparum and P. berghei sporozoites and exoerythrocytic parasites. CSP-2 is a sporozoite surface protein common to P. falciparum and P. berghei that elicits antibody-mediated protection, and is also found within P. berghei EE parasites. LSA is a P. falciparum EE-specific antigen localized within the parasitophorous vacuole. LSA-2 is a P. berghei EE-specific antigen, localized on the parasitophorous vacuole membrane, that protected mice to P. berghei sporozoite challenge, and elicited cytotoxic T cells that killed P. berghei EE parasites in vitro.

Amino Acid Sequence

Malignant melanoma and pigmented lesions: a diagnostic and management dilemma.

We document two cases of malignancy occurring at the site of partially removed benign nevi. Because of the difficulty in clinical diagnosis and the uncertainty in its behavior, we propose that any recurring melanocytic nevus expanding beyond the original surgical scar be re-excised and the specimen carefully analyzed to ensure complete removal.

Adult

Pre-erythrocytic stage malaria parasites: non-circumsporozoite protein antigens.

A series of non-circumsporozoite proteins found in pre-erythrocytic parasites are being developed as putative vaccine candidates. It is anticipated that these will be useful in addition to, rather than instead of, the CS (circumsporozoite) vaccines. It is likely that a greater understanding of the basic biology of malaria parasite-host relationships will lead to development of improved malarial vaccines.

Animals

Inflammatory granuloma annulare.

A case of inflammatory granuloma annulare occurring on the extremities of a young girl is presented. The lesions became erythematous and edematous concurrently with a self-limited gastrointestinal disorder. Many neutrophils were present in the biopsy specimen, which exhibited the changes of granuloma annulare.

Biopsy

Ketoconazole-treated sporotrichosis in a veterinarian.

A 63-year-old veterinarian acquired sporotrichosis presumably from handling an infected cat. Treatment was successfully completed with ketoconazole, 200 to 400 mg a day for eight weeks. No side effects were noted.

Animals