A comparative study of Ki-67 antigen expression between luminal A and triple-negative subtypes of breast cancer.

Tumor biomarkers such as hormone receptors, HER-2 and Ki-67 are used routinely in clinical practice for classification of molecular subtypes of breast cancer. Cell proliferation evaluated by Ki-67 antigen expression is important to determine tumor aggressiveness. However, there is a paucity of studies comparing Ki-67 expression in an expressive number of cells among molecular subtypes of breast cancer, particularly among less and more aggressive tumors, such as luminal A and triple-negative, which have led us to the present study. The current study included invasive ductal carcinoma samples of 59 patients, which were divided into two groups: luminal A (n = 29) and triple-negative (n = 30). For immunohistochemical reaction, the samples were incubated with monoclonal anti-Ki-67 antibody (clone MIB1) and cells expressing Ki-67 protein were identified by dark brown staining of the nuclei, counting at least 600 cells per slide. The mean percentages of stained nuclei were analyzed by Student's t test (p < 0.05). The mean percentage of nuclei stained with anti-ki-67 was 10.14 and 77.22 in luminal A and triple-negative breast cancers, respectively (p < 0.0001). Our study showed a high cell proliferation of triple-negative breast cancer in comparison with luminal A, justifying its aggressiveness and poor clinical outcome.

Effect of a gel containing pilocarpine on vaginal atrophy in castrated rats.

OBJECTIVES: To evaluate the effect of Carbopol gel formulations containing pilocarpine on the morphology and morphometry of the vaginal epithelium of castrated rats. METHODS: Thirty-one female Wistar-Hannover rats were randomly divided into four groups: the control Groups I (n=7, rats in persistent estrus; positive controls) and II (n=7, castrated rats, negative controls) and the experimental Groups, III (n=8) and IV (n=9). Persistent estrus (Group I) was achieved with a subcutaneous injection of testosterone propionate on the second postnatal day. At 90 days postnatal, rats in Groups II, III and IV were castrated and treated vaginally for 14 days with Carbopol gel (vehicle alone) or Carbopol gel containing 5% and 15% pilocarpine, respectively. Next, all of the animals were euthanized and their vaginas were removed for histological evaluation. A non-parametric test with a weighted linear regression model was used for data analysis (p<0.05). RESULTS: The morphological evaluation showed maturation of the vaginal epithelium with keratinization in Group I, whereas signs of vaginal atrophy were present in the rats of the other groups. Morphometric examinations showed mean thickness values of the vaginal epithelium of 195.10±12.23 µm, 30.90±1.14 µm, 28.16±2.98 µm and 29.84±2.30 µm in Groups I, II, III and IV, respectively, with statistically significant differences between Group I and the other three groups (p<0.0001) and no differences between Groups II, III and IV (p=0.0809). CONCLUSION: Topical gel formulations containing pilocarpine had no effect on atrophy of the vaginal epithelium in the castrated female rats.