Abstract. Recent studies demonstrate that apoptosis is an important process in physiological and pathological cell death. We examined the apoptotic phenomena in thyroid tissues by two methods: immunohistological and in situ end-labeling of fragmented DNA (ISEL). In thyroid tissues from patients with Hashimoto's thyroiditis and thyroid cancer, fragmented nuclear DNA and LeY (apoptosis associated antigen) were observed. In tissues from patients with Graves' disease, LeY and bcl-2 oncoprotein were expressed, but no ISEL positive cells were observed. In contrast, thyrocytes in normal thyroid tissues were not stained with ISEL or anti-L&' antibodies (Abs). Fas antigen (Ag) was expressed in various thyroid tissues, including normal subjects. The clinical meaning of this was not determined. These results suggest that the apoptotic process takes place in Hashimoto's thyroiditis and thyroid cancer, and is overcome in Graves' disease by bcl-2 expression.

An enantioselective total synthesis of both enantiomers of caryophyllene-type sesquiterpenoid pestalotiopsin A has been achieved, thereby establishing the absolute stereochemistry of natural (+)-pestalotiopsin A. Highlights of the synthesis include a [2 + 2] cycloaddition of N-propioloyl Oppolzer's camphorsultam and ketene dialkyl acetal and subsequent highly stereoselective 1,4-hydride addition/protonation, an aldol reaction of functionalized bicyclic lactone with aldehyde, an efficient intramolecular Nozaki-Hiyama-Kishi (NHK) reaction for the construction of the highly strained (E)-cyclononene ring, and a palladium-catalyzed reduction of allylic mesylate with retention of the E configuration.

To clarify whether the changes of free radicals and its scavengers are induced by thyroid disorders, we measured levels of free radical scavengers and checked °2 radical generating systems in the human thyroid gland.Thyroid specimens from patients with Graves' disease, follicular adenoma, and papillary and follicular carcinomas contained significantly higher concentrations of xanthine oxidase (XOD) and gluthathione peroxidase (GSH-PX), compared to those in the normal thyroid tissue. Catalase concentration was significantly lower in thyroid specimens from patients with Graves' disease and significantly lower in thyroid specimens from patients with follicular adenoma, compared to those in the normal thyroid tissue. Cu/Zn superoxide dismutase (CuIZn SOD) concentration was significantly lower in the specimens from follicular adenoma and papillary carcinoma and Mn SOD concentration was significantly higher in the specimens from papillary carcinoma than those in the normal thyroid tissue. The lipid peroxide concentration, expressed as malondialdehyde (MDA) concentration, was significantly higher in the specimens from papillary carcinoma than those in the normal thyroid tissue.These findings suggest that the levels of free radicals are increased and are scavenged and catalyzed in the thyroid of Graves' disease, whereas free radicals and lipid peroxide are not completely scavenged in papillary carcinoma tissues, suggesting that these substances affect some role in cell function of thyroid tumors.

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