Protocol for absolute quantification of proteins in Gram-negative bacteria based on QconCAT-based labeled peptides.

Mass-spectrometry-based absolute protein quantification uses labeled quantification concatamer (QconCAT) as internal standards (ISs). To calculate the amount of protein(s), the ion intensity ratio between the analyte and its cognate IS is compared in each biological sample. The present protocol describes a systematic workflow to design, produce, and purify QconCATs and to quantify soluble proteins in Pseudomonas putida KT2440. Our methodology enables the quantification of detectable peptide and serves as a versatile platform to produce ISs for different biological systems.

Ultrasound-Guided Breast-Conservative Surgery Decreases the Rate of Reoperations for Palpable Breast Cancer.

The purpose of this study is to verify whether the performance of ultrasound-guided quadrantectomy (USGQ) versus palpation-guided quadrantectomy (PGQ) can reduce the incidence of positive margins and if it can change the attitude of the surgeon. A retrospective study was conducted on 842 patients underwent quadrantectomy for breast cancer, 332 of them underwent USGQ, whereas 550 underwent PGQ. The histological type of the tumors and the margin status obtained with the histological examination were compared. The histological examination of the surgical specimen showed involvement of the margins in 24/842 patients (2.85%), 22 (2.61%) of them belonged to the PGQ group, and two to the USGQ group (P = 0.0011). The highest rate of microscopically positive margins was, statistically significant, for carcinoma in situ, when compared with patients with invasive carcinoma (0.0001). USGQ technique showed several advantages compared with PGQ. In fact, the former notes a lower positive margin rate and, consequently, a lower rate of reintervention. In addition, it may change the surgeon's attitude by causing him to remove another slice of margin to ensure more histological negativity. It should be the gold standard technique for breast-conservative surgery of palpable tumors.

The prognostic value of sentinel lymph node micrometastases in patients with invasive breast carcinoma.

AIM: The prognostic value of sentinel lymph node micrometastases in invasive breast cancer patients is still widely debated. Even if, in the absence of unequivocal guidelines, the axillary lynphadenectomy is not still performed in the routine clinical care of these patients. METHOD: We have retrospectively analyzed 746 patients with operable invasive breast cancer and clinically negative axillary lymph nodes. These patients underwent conservative surgery or total mastectomy with sentinel lymph node biopsy. Patients with micrometastases in the sentinel lymph node treated with axillary dissection has been checked and the involvement of the remaining lymph nodes analyzed. Patients with micrometastases in the SLN not followed by axillary dissection have been checked as well and the incidence of recurrences has been evaluated in both groups. RESULTS: Micrometastases were found in 51 (6.83%) patients and isolated tumor cells in 8 (1.07%) patients at frozen section and confirmed at the final hystopathologic examination. Fifteen of these patients underwent complete axillary dissection: two of them (13.33%) had metastatic involvement of other axillary lymph nodes. The other 44 patients didn't receive further surgical axillary procedure. No axillary recurrences in these patients were found during a median follow up of 65.3±9.65 months (range 42-78 months). CONCLUSION: Based on the results and according to some recent randomized trials we can say that axillary lynphadenectomy can be avoided when micrometastases are found in sentinel lynph nodes. It should be performed anyway, depending on the analysis of the biomedical profile of the tumor. KEY WORDS: Breast carcinoma, Micrometases, Sentinel lymph node.