Preparation, Structural Determination, and Characterization of Electronic Properties of [5,6]- and [6,6]-Carbosilylated Sc3 N@Ih -C80.

Photochemical carbosilylation of Sc3 N@Ih -C80 with silirane 1 afforded two corresponding [5,6]-adducts, 2 and 3, and a [6,6]-adduct, 4. The structural and electronic properties of these products were characterized by means of spectroscopic, electrochemical, and theoretical methods. The structure of 2 was disclosed by means of single-crystal X-ray crystallographic analysis. Thermal isomerization of 3 to 2 was observed, whereas that of 2 to 3 proceeded less efficiently at 100 °C. Upon heating under the same conditions, adduct 4 underwent facile decomposition to afford Sc3 N@Ih -C80 , or isomerized into small amounts of 2 and 3. The relative stabilities of 2, 3, and 4 were rationalized through the results of theoretical calculations. In contrast, adducts 2, 3, and 4 were stable under the photolytic conditions employed for carbosilylation. The photochemical functionalization of Sc3 N@Ih -C80 represents a convenient synthetic method to obtain thermally labile fullerene-based products.

Preparation, Structural Determination, and Characterization of Electronic Properties of Bis-silylated and Bis-germylated Lu3 N@Ih -C80.

Bis-silylated and bis-germylated derivatives of Lu3 N@Ih -C80 (3, 4, 5) were successfully synthesized by the photochemical addition of disiliranes 1 a, 1 b or digermirane 2, and fully characterized by spectroscopic, electrochemical, and theoretical studies. Interestingly, digermirane 2 reacts more efficiently than disiliranes 1 a and 1 b because of its good electron-donor properties and lower steric hindrance around the Ge-Ge bond. The 1,4-adduct structures of 3, 4, 5 were unequivocally established by single-crystal X-ray crystallographic analyses. The electrochemical and theoretical studies reveal that the energy gaps between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) of the 1,4-adducts are remarkably smaller than those of Lu3 N@Ih -C80 , because the electron-donating groups effectively raise the HOMO levels. It is also observed that germyl groups are slightly more electron-donating than the silyl groups on the basis of the redox properties and the HOMO-LUMO energies of 4 and 5. Bis-silylation and bis-germylation are effective and versatile methods for tuning the electronic characteristics of endohedral metallofullerenes.

[Two cases of multidrug-resistant recurrent endometrial cancer successfully treated with medroxyprogesterone acetate (MPA)].

We report two cases of multidrug-resistant endometrial cancer which recurred after the initial therapy and progressed despite further anticancer chemotherapy, but could be successfully treated with medroxyprogesterone acetate (MPA). The first patient with stage IVb moderately-differentiated endometrioid adenocarcinoma of the uterine corpus underwent initial operation and postoperative chemotherapy followed by maintenance chemotherapy. Four months later, lung metastases were found. Since the hormone receptor status was positive, the patient was treated with MPA, and CR was achieved. The second patient with stage IIIc poorly-differentiated endometrioid adenocarcinoma of the uterine corpus developed lung metastases 14 months after the initial operation and postoperative chemotherapy. Subsequent chemotherapy yielded a complete response(CR). Two months later, however, a small intestinal metastasis was observed, which was treated by surgical excision and chemotherapy. The patient again remained disease-free for four months until lung metastases were observed. Since the hormone receptor status was positive, the patient was treated with MPA, and CR was achieved. No serious adverse events were observed in either patient.

[Successful desensitization protocol for patients with hypersensitivity reactions caused by carboplatin].

We report the successful desensitization of a patient with a hypersensitivity reaction to carboplatin. A 54-year-old woman with advanced ovarian cancer went into remission after 10 courses of paclitaxel plus carboplatin (TC). After 7 months, cancer recurred in the vaginal cuff, and surgery was performed. Cancer recurred again in the vaginal cuff 6 months later, and she was administered TC. A hypersensitivity reaction attributed to carboplatin occurred during the third and fourth courses, and the drug was withdrawn. Because the initial response to TC was good, we decided to attempt desensitization to carboplatin. The desensitization procedure was successful, and the patient subsequently tolerated four additional courses of TC, with no further signs or symptoms of hypersensitivity. A complete response was achieved. A carboplatin desensitization regimen may allow patients with platinum-sensitive ovarian cancer to continue to benefit from therapy.