The biosynthesis of cholesterol by subcellular particles from rat brain was studied with several labeled cholesterol precursors as substrates. Rats from two age groups were used for preparation of the subcellular fractions: 15‐day‐old and adult. Microsomes and a soluble fraction were required for maximum biosynthesis of14C‐nonsaponifiable material. The latter was synthesized in good yield by subcellular fractions from both age groups, but 90% or more was present as14C‐squalene, when either U‐14C‐glucose, 2‐14C‐sodium acetate or 2‐14C‐mevalonic acid was the radioactive substrate. Neither3H‐squalene oxide nor14C‐lanosterol was converted to sterol when incubated with microsomal+soluble preparations, but some 4% of14C‐desmosterol was converted to cholesterol by adult preparations. Thus a metabolic block, largely between squalene to desmosterol, exists in isolated microsomal+soluble preparations from both 15‐day‐old and adult rat brain.
Hidradenocarcinoma (HAC) is a rare adenexal tumor with a propensity for the head and neck region and extremities. We report a case of hidradenocarcinnoma in a 56-year-old woman with a mass on her right palm sampled by fine-needle aspiration and later confirmed on histological examination. Fine-needle aspiration cytology revealed a dual population of cells including polyhedral eosinophilic cells and glycogen containing cells with pale/clear cytoplasm. The nuclei were pleomorphic with prominent nucleoli. Occassional papillary structures were identified on the cell block material. A series of immunohistochemical stains were performed and an adnexal neoplasm was suggested. The mass was resected. On histologic sections, infiltration into the adjacent soft tissue was identified. After an additional series of immunohistochemical stains, the diagnosis was confirmed as a HAC. Herein, we present our findings and discuss the differential diagnoses.
SUMMARY: Using thin‐layer chromatography and gas‐liquid chromatography the following substances were identified in banana pulp (Musa saplentum L.): Cycloartenol, cycloeucalenol, 24‐methylene cycloartanol, campesterol, β‐sitosterol and stigmasterol. The major triterpene was 24‐methylene cycloartanol while β‐sitosterol accounted for greater than 72% of the sterol fraction.
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