333 research outputs found
The Association between Vitamin D Receptor Expression and Prolonged Overall Survival in Breast Cancer.
Summary
In this study, we analyzed vitamin D receptor (VDR) expression and survival in a breast cancer patient cohort of 82 breast
cancer patients. Immunohistochemical analysis was possible in 91.5% of the patients (75/82). Staining was evaluated using the
semi-quantitative assay according to Remmele and Stegner (immunoreactivity score [IRS]). IRS 0â1 was negative/very low, IRS
2â4 was moderate to high, and IRS 6â12 was high. Statistical analysis was performed by Spearmanâs correlation test (p<0.05
significant). Overall survival was analyzed using Kaplan-Meier estimations. Only 6 patients had a negative IRS. Moderate IRS
values were present in 20 patients. Most of the patients had a high IRS (49). For survival analysis, data were dichotomized
(IRS 0â4: negative to moderate and IRS 6â12: high VDR expression). In univariate analysis, VDR expression showed significant
differences in progression-free survival (PFS) and overall survival (OS). Patients with high IRS scores showed significantly better
PFS and OS than patients with moderate/negative IRS scores for VDR expression. Tumor size was significantly correlated to
PFS. When analyzed separately, the three different IRS groups showed significant differences in VDR expression. The present
data suggest that VDR expression in breast cancer tissue may be of clinical significance, and the results provide evidence that
VDR may be a factor with prognostic relevance. (J Histochem Cytochem 60:121â129, 2012).
Keywords: breast cancer, vitamin D receptor, immunohistochemistry, prognosi
Deciphering the physiological response of Escherichia coli under high ATP demand
One longâstanding question in microbiology is how microbes buffer perturbations in energy metabolism. In this study, we systematically analyzed the impact of different levels of ATP demand in Escherichia coli under various conditions (aerobic and anaerobic, with and without cell growth). One key finding is that, under all conditions tested, the glucose uptake increases with rising ATP demand, but only to a critical level beyond which it drops markedly, even below wildâtype levels. Focusing on anaerobic growth and using metabolomics and proteomics data in combination with a kinetic model, we show that this biphasic behavior is induced by the dual dependency of the phosphofructokinase on ATP (substrate) and ADP (allosteric activator). This mechanism buffers increased ATP demands by a higher glycolytic flux but, as shown herein, it collapses under very low ATP concentrations. Model analysis also revealed two major rateâcontrolling steps in the glycolysis under high ATP demand, which could be confirmed experimentally. Our results provide new insights on fundamental mechanisms of bacterial energy metabolism and guide the rational engineering of highly productive cell factories
Python Coding Style Compliance on Stack Overflow
Software developers all over the world use Stack Overflow (SO) to interact and exchange code snippets. Research also uses SO to harvest code snippets for use with recommendation systems. However, previous work has shown that code on SO may have quality issues, such as security or license problems. We analyse Python code on SO to determine its coding style compliance. From 1,962,535 code snippets tagged with 'python', we extracted 407,097 snippets of at least 6 statements of Python code. Surprisingly, 93.87% of the extracted snippets contain style violations, with an average of 0.7 violations per statement and a huge number of snippets with a considerably higher ratio. Researchers and developers should, therefore, be aware that code snippets on SO may not representative of good coding style. Furthermore, while user reputation seems to be unrelated to coding style compliance, for posts with vote scores in the range between -10 and 20, we found a strong correlation (r = -0.87, p <; 10^-7) between the vote score a post received and the average number of violations per statement for snippets in such posts
Adenomyoepithelial tumours and myoepithelial carcinomas of the breast â a spectrum of monophasic and biphasic tumours dominated by immature myoepithelial cells
BACKGROUND: Adenomyoepithelial tumours and myoepithelial carcinomas of the breast are primarily defined by the presence of neoplastic cells with a myoepithelial immunophenotype. Current classification schemes are based on purely descriptive features and an assessment of individual prognosis is still problematic. METHODS: A series of 27 adenomyoepithelial tumours of the breast was analysed immunohistochemically with antibodies directed against various cytokeratins, p63, smooth muscle alpha-actin (SMA) and vimentin. Additionally, double immunofluorescence and comparative genomic hybridisation (CGH) was performed. RESULTS: Immunohistochemically, all the tumours showed a constant expression of high molecular weight cytokeratins (Ck) Ck5 and Ck14, p63, SMA and vimentin. With exception of one case diagnosed as myoepithelial carcinoma, all tested tumours expressed low molecular weight cytokeratin Ck18 in variable proportions of cells. Even in monophasic tumours lacking obvious glandular differentiation in conventional staining, a number of neoplastic cells still expressed those cytokeratins. Double immunofluorescence revealed tumour cells exclusively staining for Ck5/Ck14 in the presence of other cell populations that co-expressed high molecular weight Ck5/Ck14 as well as either low molecular weight Ck8/18 or SMA. Based on morphology, we assigned the series to three categories, benign, borderline and malignant. This classification was supported by a stepwise increase in cytogenetic alterations on CGH. CONCLUSION: Adenomyoepithelial tumours comprise a spectrum of neoplasms consisting of an admixture of glandular and myoepithelial differentiation patterns. As a key component SMA-positive cells co-expressing cytokeratins could be identified. Although categorisation of adenomyoepithelial tumours in benign, borderline and malignant was supported by results of CGH, any assessment of prognosis requires to be firmly based on morphological grounds. At present it is not yet clear, if and to what extent proposed Ck5-positive progenitor cells contribute to the immunohistochemical and morphological heterogeneity of these neoplasms of the breast
International Student Mobility: An Identity Development Task?
Based on the review of literature on internationalization of education and on identity formation pro
cesses in
young adults, this cross
-
sectional study aims to investigate to which extent self
-
perceived dimensions of identity
are associated to the main moti
vations to study abroad.
The
participants in this study were 429
international
university students of different nationalities. Findings revealed that the motivation to study abroa
d for personal
growth is strongly associated to the commitment and in
-
depth e
xploration
identity
processes, whereas
the
motivation to study abroad with the aim
of changing
life style and enlarging
job opportunities is positively
associated with reconsideration of commitment and in
-
depth exploration. Furthermore,
identity achieved s
tudents
showed the highest motivation to s
tudy abroad for personal growth,
while
the motivation to study abroad to
positively change
life
-
styles and work conditions
is strongly associated with the positive facet of identity crisis,
which is otherwise calle
d searching
-
moratorium status.
Based on these results, the present
survey provides useful
questions and hypothesis for future researc
An Analysis of Efficiency Improvements in Residential Sized Heat Pumps
The objectives of this study included: (1) development of
classes of heat pumps, (2) evaluation and selection of a suitable
heat pump design model, (3) characterization of suitable baseline
heat pump designs, (4) selection of design options that can be
used to improve heat pump efficiency, and (5) development of
heat pump designs to cover the whole spectrum of efficiencies
available today and those that may be technologically feasible in
the next few years
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