Evaluation of monoclonal antibody MIB-1 in the mammary epithelium adjacent to fibroadenomas in premenopausal women treated with tamoxifen.

The purpose of this study was to study the monoclonal antibody MIB-1 in the normal breast epithelium adjacent to a fibroadenoma in women in the luteal phase of the menstrual cycle who were treated with tamoxifen at doses of 10 and 20 mg for 22 days. The proliferative activity of the mammary epithelium adjacent to the fibroadenoma was studied by immunohistochemistry on the basis of the monoclonal antibody MIB-1 (Immunotech, catalog No. 0505, lot 001). The study was randomized and double blind and was conducted on 44 women with fibroadenomas divided into three groups: A (n=16, placebo), B (n=15, tamoxifen, 10 mg), and C (n=13, tamoxifen, 20 mg). Tamoxifen was administered for 22 days starting on the 2nd day of the menstrual cycle, and a biopsy was taken on the 23rd day. Serum estradiol, progesterone, sex hormone binding globulin, follicle-stimulating hormone, luteinizing hormone, and prolactin were measured before treatment (21st and 24th day of the previous menstrual cycle) and on the day of the biopsy. The mean percentage of stained nuclei per 1,000 cells was 9.2 in group A, 4.5 in group B, and 3.2 in group C. The Fisher's test revealed that tamoxifen significantly reduced MIB-1 at doses of 10 and 20 mg compared with the placebo group (p < 0.0001), with no significant differences between doses in terms of proliferative activity (p=0.21). Groups B and C presented a significant increase in progesterone (p=0.038), estradiol (p < 0.001), and sex hormone binding globulin (p=0.001) levels. Elevation of serum follicle-stimulating hormone concentration (p=0.0045) and a fall in prolactin levels (p=0.0055) were observed. We conclude that tamoxifen significantly reduced the proliferative activity of the mammary epithelium at the doses of 10 and 20 mg/day.

MYCN gene amplification. Identification of cell populations containing double minutes and homogeneously staining regions in neuroblastoma tumors.

Neuroblastoma is the second most common solid tumor occurring in children. Amplification of the MYCN oncogene is associated with poor prognosis. To identify neuroblastoma tumors with MYCN amplification, we studied the number of copies of MYCN in interphase cells by fluorescence in situ hybridization in 20 neuroblastoma patients. MYCN amplification appeared in 7 tumor specimens. Interphase and metaphase studies showed a tumor cell population with both forms of amplification, double minutes and homogeneously staining regions, in two patients. These patients showed a smaller tumor cell subpopulation with the presence of more than one homogeneously staining region, suggesting that gene amplification was undergoing karyotype evolution.

Cutaneous manifestation of Chagas' disease after heart transplantation: successful treatment with allopurinol.

We describe two patients who underwent cardiac transplantation for chronic cardiomyopathy of Chagas' disease, and in whom the disease was reactivated with the development of cutaneous lesions. In both cases, the skin lesions regressed completely after 2 months of therapy with allopurinol.

[Schwannoma of duodenum: a case report]. / Schwannoma de duodeno: relato de caso.

We report a case of malignant schwannoma of the duodenum, a neural tumor, which rarely occurs in the gastroduodenal tract. The diagnosis was done after an hemorragic episode of the upper gastrointestinal tract and the treatment done was a local resection. Two years later the patient had no symptoms, but the control endoscopy showed a recurrence of the tumor in the second portion of the duodenum and the patient was submitted to a gastroduodenopancreatectomy. The authors reported the case and make a revision on intestinal schwannomas.