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Calcitonin (CT) is a sensitive marker for medullary thyroid carcinoma. Normalization of early postoperative CT level is a favorable prognostic factor. The aim of this study was to establish the prognostic value of CT-level kinetics by preoperative tumor stage and postoperative elimination rate. Blood serum from 22 medullary thyroid carcinoma (MTC) patients without remote metastases was assayed. A commercial RIA DSL-1200 test was used to assay CT levels. Basal CT< or =42 pg/ml and stimulated CT< or =120 pg/ml were considered normal. The patients were divided into three groups according to the intensity of the postoperative CT level reduction in blood serum. Group 1 comprised patients who showed basal CT normalization within the first 2-3 days after surgery. Group 2 included those patients with slow (from 2 to 4 weeks) CT-level normalization. Group 3 included patients with CT levels that reduced within 14 days, but subsequently increased. Preoperative basal CT varies from 216 to 1654 pg/ml and depends on tumor-node-metastasis (TNM) stage. In seven patients, no basal CT decrease to normal values was observed; in five of these patients, disease recurrence was detected 2-6 months after surgery. In the group with slowly decreasing CT levels, no strong correlation between preoperative CT level and the postoperative time to normalization of basal and peak CT could be established; this may be due to the small number of patients. Our study showed that preoperative CT level depended on the disease stage. Postoperative CT elimination rate is independent of preoperative CT level. Postoperative increase in the basal or stimulated CT level is an unfavorable prognostic factor, implying disease recurrence.

The relations of catalase activity to the efficiency of symbiotic dinitrogen fixation and leghemoglobin (Lb) content were investigated in roots and nodules of several legume plant species together with the catalase distribution between the inner bacteroidal and the outer cortical nodule tissues. The catalase activity in the nodules exceeded that of the roots of the amide- and ureide-synthesizing plant species by one and two orders of magnitude. During the growth period, catalase activity and Lb content changed in parallel and reached their highest levels early in the stage of flowering or fruit formation, depending on plant species. In the case of effective symbiosis, catalase activity in the nodules was 2.5–5 times higher than in the case of ineffective symbiosis. Catalase activity in the bacteroidal zone of the nodules was several times higher than that of the cortical tissue, and two nodule tissues differed in catalase activity more notably in the plant species exporting ureides. The authors suggest that high catalase activity in the nodules, especially in their bacteroidal zone, is essential for the efficient functioning of the symbiotic system of dinitrogen fixation in both ureide- and amide-transporting plants.

An x-ray crystal structure study of 2-(2-methyl-2-propenyl)-1,3-cyclopentane-dione (C9H12O2) has been carried out. It has been shown that in the solid this compound occurs exclusively in the enol form. The molecules are bound together by strong hydrogen bonds and form infinite chains along the b-axis. According to the spectroscopic data (1H and13C NMR), the same compound in solution has a mesomeric structure.

The novel procedure specified in the title proceeds under very mild conditions.

The reaction specified in the title affords the ketone (III) via nucleophilic addition/elimination at C(2) of the starting compound (I) along with the alkenes (IV) and (V).

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Unexpectedly, the title compounds (I) is not cleaved by mineral or Lewis acids.

A convenient and highly effective method of preparation of the title compounds, e.g. (IV), is described.

The reaction between hexachlorocyclopentadiene (I) and propenolates does not afford the desired 5‐monosubstituted or 5,5‐disubstituted products, because they undergo spontaneous intramolecular (4 +2) cycloaddition.