101 research outputs found

    Targeted Metabolomics Analysis of Campylobacter coli VC167 Reveals Legionaminic Acid Derivatives as Novel Flagellar Glycans

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    Glycosylation of Campylobacter flagellin is required for the biogenesis of a functional flagella filament. Recently, we used a targeted metabolomics approach using mass spectrometry and NMR to identify changes in the metabolic profile of wild type and mutants in the flagellar glycosylation locus, characterize novel metabolites, and assign function to genes to define the pseudaminic acid biosynthetic pathway in Campylobacter jejuni 81-176 (McNally, D. J., Hui, J. P., Aubry, A. J., Mui, K. K., Guerry, P., Brisson, J. R., Logan, S. M., and Soo, E. C. (2006) J. Biol. Chem. 281, 18489-18498). In this study, we use a similar approach to further define the glycome and metabolomic complement of nucleotide-activated sugars in Campylobacter coli VC167. Herein we demonstrate that, in addition to CMP-pseudaminic acid, C. coli VC167 also produces two structurally distinct nucleotide-activated nonulosonate sugars that were observed as negative ions at m/z 637 and m/z 651 (CMP-315 and CMP-329). Hydrophilic interaction liquid chromatography-mass spectrometry yielded suitable amounts of the pure sugar nucleotides for NMR spectroscopy using a cold probe. Structural analysis in conjunction with molecular modeling identified the sugar moieties as acetamidino and N-methylacetimidoyl derivatives of legionaminic acid (Leg5Am7Ac and Leg5AmNMe7Ac). Targeted metabolomic analyses of isogenic mutants established a role for the ptmA-F genes and defined two new ptm genes in this locus as legionaminic acid biosynthetic enzymes. This is the first report of legionaminic acid in Campylobacter sp. and the first report of legionaminic acid derivatives as modifications on a protein

    Local Recurrence Rates are Low in High-Risk Neoadjuvant Breast Cancer in the I-SPY 1 Trial (CALGB 150007/150012; ACRIN 6657)

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    Increasingly, women with stage 2 and 3 breast cancers receive neoadjuvant therapy, after which many are eligible for breast-conserving surgery (BCS). The question often arises as to whether BCS, if achievable, provides adequate local control. We report the results of local recurrence (LR) from the I-SPY 1 Trial in the setting of maximal multidisciplinary treatment where approximately 50 % of patients were treated with BCS

    Outcomes after Total Skin-sparing Mastectomy and Immediate Reconstruction in 657 Breasts

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    ABSTRACT Background. Total skin-sparing mastectomy (TSSM), a technique comprising removal of all breast and nipple tissue while preserving the entire skin envelope, is increasingly offered to women for therapeutic and prophylactic indications. However, standard use of the procedure remains controversial as a result oft concerns regarding oncologic safety and risk of complications. Methods. Outcomes from a prospectively maintained database of patients undergoing TSSM and immediate breast reconstruction from 2001 to 2010 were reviewed. Outcome measures included postoperative complications, tumor involvement of the nipple-areolar complex (NAC) on pathologic analysis, and cancer recurrence. Results. TSSM was performed on 657 breasts in 428 patients. Indications included in situ cancer [111 breasts (16.9 %)], invasive cancer [301 breasts (45.8 %)], and prophylactic risk-reduction [245 breasts (37.3 %)]. A total of 210 patients (49 %) had neoadjuvant chemotherapy, 78 (18.2 %) had adjuvant chemotherapy, and 114 (26.7 %) had postmastectomy radiotherapy. Nipple tissue contained in situ cancer in 11 breasts (1.7 %) and invasive cancer in 9 breasts (1.4 %); management included repeat excision (7 cases), NAC removal (9 cases), or radiotherapy without further excision (4 cases). Ischemic complications included 13 cases (2 %) of partial nipple loss, 10 cases (1.5 %) of complete nipple loss, and 78 cases (11.9 %) of skin flap necrosis. Overall locoregional recurrence rate was 2 % (median follow-up 28 months), with a 2.4 % rate observed in the subset of patients with at least 3 years' follow-up (median 45 months). No NAC skin recurrences were observed. Conclusions. In this large, high-risk cohort, TSSM was associated with low rates of NAC complications, nipple involvement, and locoregional recurrence. Mastectomy with complete preservation of the skin envelope has been developed as an extension of skin-sparing mastectomy to improve aesthetic and psychological outcomes for patients. Nipple-sparing, or total skin-sparing, mastectomy techniques entail complete removal of all breast tissue with excision of the nipple tissue while preserving the entire skin envelope. The technique of total skin-sparing mastectomy (TSSM) is differentiated from subcutaneous mastectomy in that minimal, if any, nipple tissue is left behind. However, as with the initial reaction to skin-sparing mastectomy, there is still significant concern that preservation of the nipple-areolar complex (NAC) skin may increase locoregional recurrence rates. Although this concern has limited the widespread adoption of the technique, the recent publication of several studies with longer follow-up describing recurrence rates similar to those after skin-sparing mastectomy demonstrate that the technique does not appear to jeopardize oncologic safety

    Surgical Standards for Management of the Axilla in Breast Cancer Clinical Trials with Pathological Complete Response Endpoint.

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    Advances in the surgical management of the axilla in patients treated with neoadjuvant chemotherapy, especially those with node positive disease at diagnosis, have led to changes in practice and more judicious use of axillary lymph node dissection that may minimize morbidity from surgery. However, there is still significant confusion about how to optimally manage the axilla, resulting in variation among practices. From the viewpoint of drug development, assessment of response to neoadjuvant chemotherapy remains paramount and appropriate assessment of residual disease-the primary endpoint of many drug therapy trials in the neoadjuvant setting-is critical. Therefore decreasing the variability, especially in a multicenter clinical trial setting, and establishing a minimum standard to ensure consistency in clinical trial data, without mandating axillary lymph node dissection, for all patients is necessary. The key elements which include proper staging and identification of nodal involvement at diagnosis, and appropriately targeted management of the axilla at the time of surgical resection are presented. The following protocols have been adopted as standard procedure by the I-SPY2 trial for management of axilla in patients with node positive disease, and present a framework for prospective clinical trials and practice

    Correlations of EGFR mutations and increases in EGFR and HER2 copy number to gefitinib response in a retrospective analysis of lung cancer patients

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    <p>Abstract</p> <p>Background</p> <p>Gefitinib, a small molecule tyrosine kinase inhibitor of the Epidermal Growth Factor Receptor (<it>EGFR</it>), has shown limited efficacy in the treatment of lung cancer. Recognized clinical predictors of response to this drug, specifically female, non-smoker, Asian descent, and adenocarcinoma, together suggest a genetic basis for drug response. Recent studies have addressed the relationship between response and either sequence mutations or increased copy number of specific receptor tyrosine kinases. We set out to examine the relationship between response and the molecular status of two such kinases, <it>EGFR </it>and <it>HER2</it>, in 39 patients treated with gefitinib at the BC Cancer Agency.</p> <p>Methods</p> <p>Archival patient material was reviewed by a pathologist and malignant cells were selectively isolated by laser microdissection or manual recovery of cells from microscope slides. Genomic DNA was extracted from 37 such patient samples and exons 18–24, coding for the tyrosine kinase domain of <it>EGFR</it>, were amplified by PCR and sequenced. <it>EGFR </it>and <it>HER2 </it>copy number status were also assessed using FISH in 26 samples. Correlations between molecular features and drug response were assessed using the two-sided Fisher's exact test.</p> <p>Results</p> <p>Mutations previously correlated with response were detected in five tumours, four with exon 19 deletions and one with an exon 21 missense L858R point mutation. Increased gene copy number was observed in thirteen tumours, seven with <it>EGFR </it>amplification, three with <it>HER2 </it>amplification, and three with amplification of both genes. In our study cohort, a correlation was not observed between response and <it>EGFR </it>mutations (exon 19 deletion p = 0.0889, we observed a single exon 21 mutation in a non-responder) or increases in <it>EGFR </it>or <it>HER2 </it>copy number (p = 0.552 and 0.437, respectively).</p> <p>Conclusion</p> <p>Neither mutation of <it>EGFR </it>nor increased copy number of <it>EGFR </it>or <it>HER2 </it>was diagnostic of response to gefitinib in this cohort. However, validation of these features in a larger sample set is appropriate. Identification of additional predictive biomarkers beyond <it>EGFR </it>status may be necessary to accurately predict treatment outcome.</p
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