174 research outputs found
A New Economic Dispatch for Coupled Transmission and Active Distribution Networks Via Hierarchical Communication Structure
Traditionally, the economic dispatch problem (EDP) of the bulk generators connected to transmission networks (TNs) is solved in a centralized dispatching center (CDC) while modeling distribution networks as passive loads. With the increasing penetration levels of distributed generation, coordinating the economic dispatch between TNs and active distribution networks (ADNs) became vital to maximizing system efficiency. This article proposes a hierarchical communication structure, which requires minimal upgrades to the CDC, for solving the EDP of coupled TNs and ADNs. Based on the minimal data transfer between the CDC and distribution network operators, the problem is formulated and solved while considering the network losses in both TNs and ADNs. Furthermore, a sensitivity analysis is conducted to assess the effect of the ratio of the distribution lines on the economic dispatch solution and the operational cost of the system. The numerical results demonstrate the effectiveness of the proposed centralized scheme and highlight the significance of considering the network losses of both TNs and ADNs when solving the EDP. The results show that the proposed framework can achieve savings of up to 17.98% by taking into account the network losses of TNs and ADNs
Hypersensitive K303R oestrogen receptor-α variant not found in invasive carcinomas
INTRODUCTION: Genetic abnormalities or mutations in premalignant breast lesions may have a role in progression toward malignancy or influence the behaviour of subsequent disease. The A908G (Lys303→Arg) change in the gene encoding oestrogen receptor-α (ER-α) creates a hypersensitivity to oestradiol and would have significant consequences if present in breast carcinoma, especially those treated with endocrine therapy. We have therefore examined a panel of endocrine-treated invasive carcinomas for the presence of this mutation. METHODS: Sequencing of control DNA was shown to detect mutation present in as little as 15% of the starting material. Enrichment for the mutation by using MboII restriction digestion allowed the detection of mutant present at 1% or less. We applied these techniques to genomic DNA and cDNA from 136 invasive breast carcinomas. RESULTS: No evidence of the A908G mutation was found with either technique. The incidence of this mutation in our panel of tumours is therefore significantly less than previously reported. CONCLUSION: The fact that the mutation was not found leads us to believe that this mutation is absent from most cells in invasive carcinomas and furthermore that the major expression product of the ER-α gene in cancers does not contain the K303R mutation. It is therefore unlikely to influence the effectiveness of endocrine treatment
Increased risk of malignant progression in benign proliferating breast lesions defined by expression of heat shock protein 27
Estrogen and progesterone receptor levels in nonneoplastic breast epithelium of breast cancer cases versus benign breast biopsy controls
<p>Abstract</p> <p>Background</p> <p>Previous studies and biological mechanisms of carcinogenesis suggest that the steroid receptor content of benign breast epithelium may be related to breast cancer risk. The objective in this study was to compare the levels of estrogen receptor-α (ER) and progesterone receptor (PR) in nonneoplastic breast epithelium between breast cancer cases and biopsy controls.</p> <p>Methods</p> <p>Between 1995 and 1997 at two sites (Women's College Hospital in Toronto and Kingston General Hospital), 667 women who were scheduled for diagnostic excisional breast biopsies completed a questionnaire providing personal information and agreed to allow analysis of routinely resected tissue. Histological slides with nonneoplastic epithelium were available for 101 cancer cases and 200 biopsy controls in Toronto and for 105 cancer cases and 119 controls in Kingston. Nonneoplastic epithelium was examined with immunohistochemical assays to determine the percent of epithelial cells staining for ER and PR. Unconditional logistic regression was used to calculate odds ratios (OR) stratified by study site.</p> <p>Results</p> <p>The ER content of nonneoplastic tissue was higher in cases than biopsy controls in unadjusted analyses; after adjustment for age, however, a weak association remained in only one of the study sites. After adjustment for age, the PR content of nonneoplastic tissue was slightly lower in breast cancer cases than controls in one study site. Furthermore, this inverse association was confined to women with PR negative breast cancer in comparison to the controls. No interaction between ER and PR content of nonneoplastic tissue was observed in relation to the odds of having breast cancer.</p> <p>Conclusion</p> <p>The results of this study are consistent with only a slight indication of increased ER levels in nonneoplastic tissue in breast cancer cases relative to controls. This study contributes to the understanding of breast cancer by examining both ER and PR in nonneoplastic tissue. Limitations remain, however, such as the necessity of using as controls women with benign breast changes, difficulties in selecting the appropriate tissue for analysis, and tissue sampling concurrent to diagnosis.</p
The NeST (Neoadjuvant systemic therapy in breast cancer) study: National Practice Questionnaire of United Kingdom multi-disciplinary decision making.
BACKGROUND: Neoadjuvant systemic therapy (NST) is increasingly used in the treatment of breast cancer, yet it is clear that there is significant geographical variation in its use in the UK. This study aimed to examine stated practice across UK breast units, in terms of indications for use, radiological monitoring, pathological reporting of treatment response, and post-treatment surgical management. METHODS: Multidisciplinary teams (MDTs) from all UK breast units were invited to participate in the NeST study. A detailed questionnaire assessing current stated practice was distributed to all participating units in December 2017 and data collated securely usingREDCap. Descriptive statistics were calculated for each questionnaire item. RESULTS: Thirty-nine MDTs from a diverse range of hospitals responded. All MDTs routinely offered neoadjuvant chemotherapy (NACT) to a median of 10% (range 5-60%) of patients. Neoadjuvant endocrine therapy (NET) was offered to a median of 4% (range 0-25%) of patients by 66% of MDTs. The principal indication given for use of neoadjuvant therapy was for surgical downstaging. There was no consensus on methods of radiological monitoring of response, and a wide variety of pathological reporting systems were used to assess tumour response. Twenty-five percent of centres reported resecting the original tumour footprint, irrespective of clinical/radiological response. Radiologically negative axillae at diagnosis routinely had post-NACT or post-NET sentinel lymph node biopsy (SLNB) in 73.0 and 84% of centres respectively, whereas 16% performed SLNB pre-NACT. Positive axillae at diagnosis would receive axillary node clearance at 60% of centres, regardless of response to NACT. DISCUSSION: There is wide variation in the stated use of neoadjuvant systemic therapy across the UK, with general low usage of NET. Surgical downstaging remains the most common indication of the use of NAC, although not all centres leverage the benefits of NAC for de-escalating surgery to the breast and/or axilla. There is a need for agreed multidisciplinary guidance for optimising selection and management of patients for NST. These findings will be corroborated in phase II of the NeST study which is a national collaborative prospective audit of NST utilisation and clinical outcomes
Recurrent rare copy number variants increase risk for esotropia
Purpose: To determine whether rare copy number variants (CNVs) increase risk for comitant esotropia. Methods: CNVs were identified in 1614 Caucasian individuals with comitant esotropia and 3922 Caucasian controls from Illumina SNP genotyping using two Hidden Markov model (HMM) algorithms, PennCNV and QuantiSNP, which call CNVs based on logR ratio and B allele frequency. Deletions and duplications greater than 10 kb were included. Common CNVs were excluded. Association testing was performed with 1 million permutations in PLINK. Significant CNVs were confirmed with digital droplet polymerase chain reaction (ddPCR). Whole genome sequencing was performed to determine insertion location and breakpoints. Results: Esotropia patients have similar rates and proportions of CNVs compared with controls but greater total length and average size of both deletions and duplications. Three recurrent rare duplications significantly (P = 1 × 10-6) increase the risk of esotropia: chromosome 2p11.2 (hg19, 2:87428677-87965359), spanning one long noncoding RNA (lncRNA) and two microRNAs (OR 14.16; 95% confidence interval [CI] 5.4-38.1); chromosome 4p15.2 (hg19, 4:25554332-25577184), spanning one lncRNA (OR 11.1; 95% CI 4.6-25.2); chromosome 10q11.22 (hg19, 10:47049547-47703870) spanning seven protein-coding genes, one lncRNA, and four pseudogenes (OR 8.96; 95% CI 5.4-14.9). Overall, 114 cases (7%) and only 28 controls (0.7%) had one of the three rare duplications. No case nor control had more than one of these three duplications. Conclusions: Rare CNVs are a source of genetic variation that contribute to the genetic risk for comitant esotropia, which is likely polygenic. Future research into the functional consequences of these recurrent duplications may shed light on the pathophysiology of esotropia
Characterisation of male breast cancer: a descriptive biomarker study from a large patient series
Male breast cancer (MBC) is rare. We assembled 446 MBCs on tissue microarrays and assessed clinicopathological information, together with data from 15 published studies, totalling 1984 cases. By immunohistochemistry we investigated 14 biomarkers (ERα, ERβ1, ERβ2, ERβ5, PR, AR, Bcl-2, HER2, p53, E-cadherin, Ki67, survivin, prolactin, FOXA1) for survival impact. The main histological subtype in our cohort and combined analyses was ductal (81%, 83%), grade 2; (40%, 44%), respectively. Cases were predominantly ERα (84%, 82%) and PR positive (74%, 71%), respectively, with HER2 expression being infrequent (2%, 10%), respectively. In our cohort, advanced age (>67) was the strongest predictor of overall (OS) and disease free survival (DFS) (p = 0.00001; p = 0.01, respectively). Node positivity negatively impacted DFS (p = 0.04). FOXA1 p = 0.005) and AR p = 0.009) were both positively prognostic for DFS, remaining upon multivariate analysis. Network analysis showed ERα, AR and FOXA1 significantly correlated. In summary, the principle phenotype of MBC was luminal A, ductal, grade 2. In ERα+ MBC, only AR had prognostic significance, suggesting AR blockade could be employed therapeutically
Autocrine regulation of cell proliferation by estrogen receptor-alpha in estrogen receptor-alpha-positive breast cancer cell lines
Heat shock protein90 in lobular neoplasia of the breast
<p>Abstract</p> <p>Background</p> <p>Heat shock protein 90 (Hsp90) overexpression has been implicated in breast carcinogenesis, with putative prognostic and therapeutic implications. The purpose of this study is to evaluate the immunohistochemical expression of Hsp90 and to examine whether Hsp90 expression is associated with estrogen receptor alpha (ER-alpha) and beta (ER-beta) immunostaining in lobular neoplasia (LN) of the breast.</p> <p>Methods</p> <p>Tissue specimens were taken from 44 patients with LN. Immunohistochemical assessment of Hsp90, ER-alpha and ER-beta was performed both in the lesion and the adjacent normal breast ducts and lobules; the latter serving as control. As far as Hsp90 evaluation is concerned: i) the percentage of positive cells, and ii) the intensity was separately analyzed. Additionally, the Allred score was adopted and calculated. Accordingly, Allred score was separately evaluated for ER-alpha and ER-beta. The intensity was treated as an ordinal variable-score (0: negative, low: 1, moderate: 2, high: 3). Statistical analysis followed.</p> <p>Results</p> <p>Hsp90 immunoreactivity was mainly cytoplasmic in both the epithelial cells of normal breast (ducts and lobules) and LN. Some epithelial cells of LN also showed nuclear staining, but all the LN foci mainly disclosed a positive cytoplasmic immunoreaction for Hsp90. In addition, rare intralobular inflammatory cells showed a slight immunoreaction. The percentage of Hsp90 positive cells in the LN areas was equal to 67.1 ± 12.2%, whereas the respective percentage in the normal adjacent breast tissue was 69.1 ± 11.6%; the difference was not statistically significant. The intensity score of Hsp90 staining was 1.82 ± 0.72 in LN foci, while in the normal adjacent tissue the intensity score was 2.14 ± 0.64. This difference was statistically significant (p = 0.029, Wilcoxon matched-pairs signed-ranks test). The Hsp90 Allred score was 6.46 ± 1.14 in the LN foci, significantly lower than in the normal adjacent tissue (6.91 ± 0.92, p = 0.049, Wilcoxon matched-pairs signed-ranks test). Within the LN foci, the Hsp90 Allred score was neither associated with ER-alpha, nor with ER-beta percentage.</p> <p>Conclusion</p> <p>Hsp90 was lower in LN foci both at the level of intensity and Allred score, a finding contrary to what might have been expected, given that high Hsp90 expression is detected in invasive breast carcinomas. Hsp90 deregulation does not seem to be a major event in LN pathogenesis.</p
Role of gonadotropin-releasing hormone analogues in metastatic male breast cancer: Results from a pooled analysis
Background: Male breast cancer is a rare malignancy. Despite the lack of prospectively generated data from trials in either the adjuvant or metastatic setting, patients are commonly treated with hormone therapies. Much controversy exists over the use of gonadotropin-releasing hormone analogues in metastatic male breast cancer patients. We conducted this study to provide more concrete ground on the use of gonadotropin-releasing hormone analogues in this setting. Methods: We herein present results from a pooled analysis including 60 metastatic male breast cancer patients treated with either an aromatase inhibitor or cyproterone acetate as a monotherapy (23 patients) or combined with a gonadotropin-releasing hormone analogue (37 patients). Results: Overall response rate was 43.5 % in patients treated with monotherapy and 51.3 % with combination therapy (p = 0.6). Survival outcomes favored combination therapy in terms of median progression-free survival (11.6 months versus 6 months; p = 0.05), 1-year progression-free survival rate (43.2 % versus 21.7 %; p = 0.05), median overall survival (29.7 months versus 22 months; p = 0.05), and 2-year survival rate (64.9 % versus 43.5 %; p = 0.05). Conclusions: In metastatic male breast cancer patients, the combined use of gonadotropin-releasing hormone analogues and aromatase inhibitors or antiandrogens seems to be associated with greater efficacy, particularly in terms of survival outcomes, compared with monotherapy. Collectively, these results encourage considering these agents in the metastatic setting
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