Non-percolating small metallic clusters and sharp suppression of metallicity in RE0.55Sr0.45Mn1−xRuxO3manganites

The origin of the anomalous sharp phase transition from a ferromagnetic metal into a ferromagnetic insulator has been investigated in ruthenium (Ru)-doped RE_0.55Sr_0.45Mn_1−xRu_xO₃(0 ≤x≤ 0.25) manganites (RESRMO) with RE(A-site) = Sm, Eu and Gd.

Electron beam induced tunneling magnetoresistance in spatially confined manganite bridges

Certain manganites exhibit rich and technologically relevant transport properties which can often be attributed to the existence and changes of the intrinsic electronic phase competition within these materials. Here we demonstrate that a scanning electron beam can be used to artificially create domain configurations within La_0.3Pr_0.4Ca_0.3MnO₃ thin film microbridges that results in novel magneto-transport effects. In particular, the electron beam preferentially produces insulating regions within the narrow film and can be used to create a configuration consisting of ferromagnetic metallic domains separated by a potential barrier. This arrangement enables the spin-dependent tunneling of charge carriers and can produce large switching tunneling magnetoresistance effects which were initially absent. Hence, this work describes a new and potentially powerful method for engineering the electronic phase domains in manganites to generate functional transport properties that are important for spintronic devices.

Short communication: Antioxidative and antibacterial activities on Staphylococcus aureus and Escherichia coli O157:H4 in milk with added ginseng marc extract fermented by Lactobacillus plantarum KCCM 11613P

Ginseng marc, a by-product of the extraction of fresh ginseng, is known to have bioactive compounds, but is frequently discarded as agriculture waste. The objectives of our study were to assess the antioxidative activity of fermented ginseng marc extract using Lactobacillus plantarum KCCM 11613P and to evaluate antibacterial activity of fermented milk with added ginseng marc extract during fermentation. After 24 h of fermentation of ginseng marc extract, the viable cell number was increased to 7.7 ± 0.1 log cfu/mL, and the pH and total titratable acidity were 4.2 ± 0.4 and 0.6% lactic acid, respectively. The total phenolic and flavonoid contents of fermented ginseng marc extract increased by 32.4 and 23.3%, respectively. Higher antioxidative activity of fermented ginseng marc extract was obtained in the β-carotene bleaching, ferric-reducing ability of plasma, and ferric thiocyanate assays than the 1,1-diphenyl-2-picrylhydrazy assay. However, the 1,1-diphenyl-2-picrylhydrazy scavenging effect decreased due to lowered pH. During production of fermented milk with ginseng, inhibition rate of Staphylococcus aureus and Escherichia coli were 9.7 and 2.3%, respectively. The present study shows the possibilities of Lactobacillus plantarum KCCM 11613P used as a fermentation strain and ginseng marc used as a functional supplement in milk.

Abstract P2-01-36: Ex vivo shear-wave elastography of axillary lymph nodes predicting nodal metastasis in patients with primary breast cancer: A pilot study

Objective: To evaluate the feasibility of shear-wave elastography using breast ultrasonography in identifying metastasis of removed sentinel lymph nodes during the operation for treatment of breast cancer.

Background: Conventional method for identification of sentinel nodal metastasis is time and cost consuming. The optimal method for identification of nodal status is important.

Methods: Excised sentinel lymph nodes during the operation were prospectively examined with the elastography. Metastatic status of lymph nodes was confirmed with permanent histology. Only macrometastasis was regarded as positive. Elastic values measured by the ex vivo elastography and nodal characteristics were analyzed to correlate with nodal metastasis.

Results: A total of 274 lymph nodes harvested from 68 breast cancer patients at Gangnam Severance Hospital from May 2014 to April 2015 were included this study. There was the difference of elastic values between nodes with and without metastasis (mean stiffness, 41.6 kPa and 17.4 kPa, P < 0.001). Mean sizes of metastatic nodes (range 0.36-2.59 cm) were significantly larger than that of non-metastatic nodes (1.0 cm versus 0.75 cm, P < 0.001). Moreover, there was a correlation between the size of metastatic nodes which ranged from 0.7 to 21.5 mm with a median of 7 mm and nodal stiffness (correlation coefficient of mean stiffness, r = 0.431). The area under the receiver operating characteristic curve (AUC) by the mean stiffness was 0.794. The combination of size of nodes, mean stiffness and ratio made AUC of 0.856.

Conclusions: In our study, ex vivo shear-wave elastography of sentinel lymph nodes was a feasible method to predict metastasis. Through the validation study, ex vivo elastography could be helpful to determine metastasis of sentinel lymph nodes during the operation.

Keywords Breast cancer; Elastography; Lymph node metastasis.

Citation Format: Lim JW, Lee HW, Park JT, Ahn SG, Jung J. Ex vivo shear-wave elastography of axillary lymph nodes predicting nodal metastasis in patients with primary breast cancer: A pilot study [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-01-36.

Association between basal-like phenotype and BRCA1/2 germline mutations in Korean breast cancer patients

INTRODUCTION

BRCA mutation testing allows index patients and their families to be provided with appropriate cancer risk-reduction strategies. Because of the low prevalence of BRCA mutations in unselected breast cancer patients and the high cost of genetic testing, it is important to identify the subset of women who are likely to carry BRCA mutations. In the present study, we examined the association between BRCA1/2 germline mutations and the immunohistochemical features of breast cancer.

METHODS

In a retrospective review of 498 breast cancer patients who had undergone BRCA testing at Seoul National University Bundang Hospital between July 2003 and September 2012, we gathered immunohistochemical information on estrogen receptor (er), progesterone receptor (pr), her2 (human epidermal growth factor receptor 2), cytokeratin 5/6, egfr (epidermal growth factor receptor), and p53 status.

RESULTS

Among the 411 patients eligible for the study, 50 (12.2%) had germline mutations in BRCA1 or BRCA2. Of the 93 patients with triple-negative breast cancer (tnbc), 25 with BRCA1/2 mutations were identified (BRCA1, 20.4%; BRCA2, 6.5%). On univariate analysis, er, pr, cytokeratin 5/6, egfr, and tnbc were found to be related to BRCA1 mutations, but on multivariate analysis, only tnbc was significantly associated with BRCA1 mutations. Among patients with early-onset breast cancer or with a family history of breast or ovarian cancer, BRCA1 mutations were significantly more prevalent in the tnbc group than in the non-tnbc group.

CONCLUSIONS

In the present study, tnbc was the only independent predictor of BRCA1 mutation in patients at high risk of hereditary breast and ovarian cancers. Other histologic features of basal-like breast cancer did not improve the estimate of BRCA1 mutation risk.