bluuebunny/crossref_metadata_2025 huggingface dataset:
New Channelrhodopsin with a Red-Shifted Spectrum and Rapid Kinetics from
Mesostigma viride
Authors: Govorunova Elena G. , Spudich Elena N. , Lane C. Elizabeth , Sineshchekov Oleg A. , Spudich John L.
Published: June 2011

Light control of motility behavior (phototaxis and photophobic responses) in green flagellate algae is mediated by sensory rhodopsins homologous to phototaxis receptors and light-driven ion transporters in prokaryotic organisms. In the phototaxis process, excitation of the algal sensory rhodopsins leads to generation of transmembrane photoreceptor currents. When expressed in animal cells, the algal phototaxis receptors function as light-gated cation channels, which has earned them the name “channelrhodopsins.” Channelrhodopsins have become useful molecular tools for light control of cellular activity. Only four channelrhodopsins, identified in
Chlamydomonas reinhardtii
and
Volvox carteri
, have been reported so far. By screening light-induced currents among algal species, we identified that the phylogenetically distant flagellate
Mesostigma viride
showed photoelectrical responses
in vivo
with properties suggesting a channelrhodopsin especially promising for optogenetic use. We cloned an
M. viride
channelrhodopsin, MChR1, and studied its channel activity upon heterologous expression. Action spectra in HEK293 cells match those of the photocurrents observed in
M. viride
cells. Comparison of the more divergent MChR1 sequence to the previously studied phylogenetically clustered homologs and study of several MChR1 mutants refine our understanding of the sequence determinants of channelrhodopsin function. We found that MChR1 has the most red-shifted and pH-independent spectral sensitivity so far reported, matches or surpasses known channelrhodopsins’ channel kinetics features, and undergoes minimal inactivation upon sustained illumination. This combination of properties makes MChR1 a promising candidate for optogenetic applications.

IMPORTANCE
Channelrhodopsins that function as phototaxis receptors in flagellate algae have recently come into the spotlight as genetically encoded single-molecule optical switches for turning on neuronal firing or other cellular processes, a technique called “optogenetics.” Only one of four currently known channelrhodopsins is widely used in optogenetics, although electrical currents recorded in diverse flagellates suggest the existence of a large variety of such proteins. We applied a strategy for the search for new channelrhodopsins with desirable characteristics by measuring rhodopsin-mediated photocurrents in microalgae, which helped us identify MChR1, a new member of the channelrhodopsin family. MChR1 exhibits several sought-after characteristics and thus expands the available optogenetic toolbox. The divergence of the MChR1 sequence from those of the four known channelrhodopsins contributes to our understanding of diversity in the primary structures of this subfamily of sensory rhodopsins.
MMP-2 and MMP-9 in lymph-node-positive bladder cancer
Authors: Seiler Roland , Thalmann George N , Fleischmann Achim
Published: June 2011

Background

Matrix metalloproteinases (MMP), particularly MMP-2 and MMP-9, participate in tumour progression and metastasis in various cancers. Their significance in urothelial cancer of the bladder (UCB) is unclear. Expression analysis of MMP-2 and MMP-9 in tissue microarrays (TMA) constructed of corresponding samples from histopathological normal urothelium, tumour centre and invasion front of primary tumours and lymph-node (LN) metastases might help to elucidate their relevance in UCB.

Method

MMP-2 and MMP-9 expression was evaluated in TMA of 150 surgically treated LN-positive UCB patients. Biomarker expression was correlated with tumour characteristics (primary tumour and LN stage, number, total diameter and extracapsular extension of LN metastases) and overall survival.

Results

While there was a significant increase in MMP-9 expression from normal urothelium over primary tumours to metastases (median scores: 20, 50, 65; p<0.005), no such trend was observed in MMP-2 (median scores: 5, 22, 10; p<0.005). A comparison of expression in the tumour centre and the invasion front showed no difference in both MMP. No association between expression and histopathological tumour characteristics was identified. There was a non-significant trend for a more favourable outcome for patients with high MMP-2 expression in primary tumours.

Conclusion

In LN-positive UCB, MMP-2 and MMP-9 expression was not increased at the invasion front, suggesting an infiltration strategy independent of MMP-2 and MMP-9 activity. Larger series are needed to detect a potential significant trend for favourable outcome in cancers with high MMP-2 expression.
Relationship between clock and star drawing and the degree of hepatic encephalopathy
Authors: Edwin Natasha , Peter John Victor , John George , Eapen C E , Graham Petra L
Published: June 2011

Purpose of the study

Current hepatic encephalopathy grading tools are limited because of complexity or subjectivity. The degree of constructional apraxia could serve as a simple, objective and reproducible tool to grade encephalopathy.

Study design

In this cross-sectional study of patients with chronic liver disease, the degree of constructional apraxia was judged by their ability to copy a star and clock face and compared with conventional encephalopathy grading by the West Haven Criteria (WHC) and the Porto Systemic Encephalopathy Index (PSEI). Three blinded observers independently graded the figures. Sensitivity, specificity and positive predictive value (PPV) of clock and star scores (score 0 implying no encephalopathy and >0 hepatic encephalopathy) were assessed against conventional scoring systems (WHC grade >0 or PSEI ≥0.33 indicating encephalopathy). Mosaic and box plots were generated to assess if the degree of constructional apraxia correlated with the severity of encephalopathy.

Results

71 patients were studied between October 2008 and July 2009; 11 (15.4%) had WHC grade 0, 32 (45%) grade 1, and 28 (39.4%) grades 2 and 3 encephalopathy. The sensitivity, specificity and PPV of the clock drawing for the diagnosis of encephalopathy was 85%, 80%, and 96%, respectively, and 77%, 70%, and 94%, respectively, for the star drawing. Box plots and intervals on mean PSEI showed an increasing relationship between clock/star scores and PSEI. There was substantial agreement between WHC and clock (weighted κ 0.61) and star scores (weighted κ 0.71). Inter-observer reliability was at least 0.70 for star and at least 0.79 for the clock score.

Conclusion

Clock and star drawing may serve as reproducible, inexpensive bedside tools for diagnosing and grading the severity of hepatic encephalopathy.
How Dutch medical residents perceive their competency as manager in the revised postgraduate medical curriculum
Authors: Berkenbosch Lizanne , Brouns Judith W M , Heyligers Ide , Busari Jamiu O
Published: June 2011

Introduction

In 2005, competency based training was introduced into the curriculum of the postgraduate training of Dutch medical residents. The role as manager is one of the seven competencies and, compared to the other roles, it is presently thought to receive little attention during training. The goal of this study was to investigate medical residents' understanding of this competency and how they perceive their role as manager.

Methods

In October 2009, 506 residents from different specialties in four teaching hospitals were invited via email to participate in the study. A 29-item Likert scale questionnaire was designed to investigate residents perceived healthcare management skills and knowledge in four management areas.

Results

177 of 506 residents (35%) responded to the survey. More than half of the residents (106/177, 60%) did not feel confident in their (contract) negotiating skills and 56% (98/175) stated that they lacked sufficient knowledge of how the Dutch healthcare system is financed and organised. The residents were most confident in their ability to handle feedback (151/177, 85%), medical information data registration (168/173, 97%), and how to allocate healthcare resources based on evidence based principles (143/173, 83%).

Conclusion

These results demonstrate that residents in the Netherlands perceive their knowledge and skills in certain essential medical management concepts to be inadequate. The results suggest that a course in medical management should be considered as a mandatory part of the curricula of residency training programmes.
General practice and social service partnership for better clinical outcomes, patient self efficacy and lifestyle behaviours of diabetic care: randomised control trial of a chronic care model
Authors: Lee Albert , Siu Choi-Fong , Leung Kam-Tao , Lau Louisa C H , Chan Cathy C M , Wong Kwok-Keung
Published: June 2011

Background

The International Diabetes Attitudes, Wishes, and Needs (DAWN) programmes have shown the existence of a critical gap in self management support and access to the support system. This study aims to evaluate the effectiveness of the diabetes mellitus (DM) self management programme, with partnership between general practice and social work, on clinical outcomes, patient self efficacy and lifestyle behaviours.

Methods

In this is single blind randomised controlled trial, subjects were recruited from patients attending general outpatient clinics in the Hospital Authority New Territory East Cluster of Hong Kong. 157 subjects meeting the inclusion criteria completed the study and were randomly assigned to the experimental or control group. The experimental group underwent the six sessions of weekly DM self management course with emphasis on self efficacy and participatory approach. The outcome measurements included HbA1c concentration, DM self efficacy scale, dietary behaviours, body mass index (BMI), and waist: hip ratio.

Results

Baseline assessment observed no significant differences between experimental and control groups for the variables related to outcomes. For the experimental group, the proportion of subjects with normal HbA1c increased from 4.5% (3/66) at baseline to 28.6% (19/66) at week 28 (p<0.001), but there was insignificant improvement in the control group (3.9% to 11.8%, p=0.13). Repeated measure of analysis of variance showed pronounced improvement in DM self efficacy scale and BMI among the experimental group with significant interaction. Dietary behaviours also improved significantly in the experimental group.

Conclusion

The DM care model with partnership between general practice and social work demonstrated better diabetic control with improvement of self efficacy and minimisation of risk behaviours.

Trial registration

Current Controlled Trials ISRCTN78882965.
ON THE ABSOLUTE VALUE OF THE NEUTRINO MASS
Authors: HAJDUKOVIC DRAGAN SLAVKOV
Published: June 2011

The neutrino oscillations probabilities depend on mass squared differences; in the case of three-neutrino mixing, there are two independent differences, which have been measured experimentally. In order to calculate the absolute masses of neutrinos, we have conjectured a third relation, in the form of a sum of squared masses. The calculated masses look plausible and are in good agreement with the upper bounds coming from astrophysics.
On a Certain Class of Semigroups of Operators
Authors: Aniello Paolo
Published: June 2011

We define an interesting class of semigroups of operators in Banach spaces, namely, the randomly generated semigroups. This class contains as a remarkable subclass a special type of quantum dynamical semigroups introduced in the early 1970s by Kossakowski. Each randomly generated semigroup is associated, in a natural way, with a pair formed by a representation or an antirepresentation of a locally compact group in a Banach space and by a convolution semigroup of probability measures on this group. Examples of randomly generated semigroups having important applications in physics are briefly illustrated.
Quantum Entanglement and Quantum Discord of Two-Mode Gaussian States in a Thermal Environment
Authors: Isar Aurelian
Published: June 2011

In the framework of the theory of open systems based on completely positive quantum dynamical semigroups, we give a description of the continuous-variable quantum entanglement and quantum discord for a system consisting of two noninteracting modes embedded in a thermal environment. Entanglement and discord are used to quantify the quantum correlations of the system. For all values of the temperature of the thermal reservoir, an initially separable Gaussian state remains separable for all times. We study the time evolution of logarithmic negativity, which characterizes the degree of entanglement, and we show that in the case of an entangled initial Gaussian state, entanglement suppression (entanglement sudden death) takes place for non-zero temperatures of the environment. Only for zero temperature of the thermal bath the initial entangled state remains entangled for finite times. We analyze time evolution of Gaussian quantum discord, which is a measure of all quantum correlations in the bipartite state, including entanglement, and we show that quantum discord decays asymptotically in time under the effect of thermal bath. This is in contrast with the sudden death of entanglement. Before the suppression of entanglement, the qualitative evolution of quantum discord is very similar to that of the entanglement. We describe also time evolution of the degree of classical correlations and of quantum mutual information, which measures the total correlations of quantum system.
The General Form of γ-Family of Quantum Relative Entropies
Authors: Kostecki Ryszard Paweł
Published: June 2011

We use the Falcone–Takesaki non-commutative flow of weights and the resulting theory of non-commutative Lpspaces in order to define the family of relative entropy functionals that naturally generalise the quantum relative entropies of Jenčová–Ojima and classical relative entropies of Zhu–Rohwer, and belong to an intersection of families of Petz relative entropies with Bregman relative entropies. For the purpose of this task, we generalise the notion of Bregman entropy to the infinite-dimensional non-commutative case using the Legendre–Fenchel duality. In addition, we use the Falcone–Takesaki duality to extend the duality between coarse-grainings and Markov maps to the infinite-dimensional non-commutative case. Following the recent result of Amari for the Zhu–Rohwer entropies, we conjecture that the proposed family of relative entropies is uniquely characterised by the Markov monotonicity and the Legendre–Fenchel duality. The role of these results in the foundations and applications of quantum information theory is discussed.
Knockout of the murine cysteine dioxygenase gene results in severe impairment in ability to synthesize taurine and an increased catabolism of cysteine to hydrogen sulfide
Authors: Ueki Iori , Roman Heather B. , Valli Alessandro , Fieselmann Krista , Lam Jimmy , Peters Rachel , Hirschberger Lawrence L. , Stipanuk Martha H.
Published: June 2011

Cysteine homeostasis is dependent on the regulation of cysteine dioxygenase (CDO) in response to changes in sulfur amino acid intake. CDO oxidizes cysteine to cysteinesulfinate, which is further metabolized to either taurine or to pyruvate plus sulfate. To gain insight into the physiological function of CDO and the consequence of a loss of CDO activity, mice carrying a null CDO allele ( CDO+/− mice) were crossed to generate CDO−/−, CDO+/−, and CDO+/+ mice. CDO−/− mice exhibited postnatal mortality, growth deficit, and connective tissue pathology. CDO−/− mice had extremely low taurine levels and somewhat elevated cysteine levels, consistent with the lack of flux through CDO-dependent catabolic pathways. However, plasma sulfate levels were slightly higher in CDO−/− mice than in CDO+/− or CDO+/+ mice, and tissue levels of acid-labile sulfide were elevated, indicating an increase in cysteine catabolism by cysteine desulfhydration pathways. Null mice had lower hepatic cytochrome c oxidase levels, suggesting impaired electron transport capacity. Supplementation of mice with taurine improved survival of male pups but otherwise had little effect on the phenotype of the CDO−/− mice. H2S has been identified as an important gaseous signaling molecule as well as a toxicant, and pathology may be due to dysregulation of H2S production. Control of cysteine levels by regulation of CDO may be necessary to maintain low H2S/sulfane sulfur levels and facilitate the use of H2S as a signaling molecule.
Gut-liver interaction in triglyceride-rich lipoprotein metabolism
Authors: Xiao Changting , Hsieh Joanne , Adeli Khosrow , Lewis Gary F.
Published: June 2011

The liver and intestine have complementary and coordinated roles in lipoprotein metabolism. Despite their highly specialized functions, assembly and secretion of triglyceride-rich lipoproteins (TRL; apoB-100-containing VLDL in the liver and apoB-48-containing chylomicrons in the intestine) are regulated by many of the same hormonal, inflammatory, nutritional, and metabolic factors. Furthermore, lipoprotein metabolism in these two organs may be affected in a similar fashion by certain disorders. In insulin resistance, for example, overproduction of TRL by both liver and intestine is a prominent component of and underlies other features of a complex dyslipidemia and increased risk of atherosclerosis. The intestine is gaining increasing recognition for its importance in affecting whole body lipid homeostasis, in part through its interaction with the liver. This review aims to integrate recent advances in our understanding of these processes and attempts to provide insight into the factors that coordinate lipid homeostasis in these two organs in health and disease.
NOD1 activation induces proinflammatory gene expression and insulin resistance in 3T3-L1 adipocytes
Authors: Zhao Ling , Hu Pan , Zhou Yijun , Purohit Jaanki , Hwang Daniel
Published: June 2011

Chronic inflammation is associated with obesity and insulin resistance; however, the underlying mechanisms are not fully understood. Pattern recognition receptors Toll-like receptors and nucleotide-oligomerization domain-containing proteins play critical roles in innate immune response. Here, we report that activation of nucleotide binding oligomerization domain-containing protein-1 (NOD1) in adipocytes induces proinflammatory response and impairs insulin signaling and insulin-induced glucose uptake. NOD1 and NOD2 mRNA are markedly increased in differentiated murine 3T3-L1 adipocytes and human primary adipocyte culture upon adipocyte conversion. Moreover, NOD1 mRNA is markedly increased only in the fat tissues in diet-induced obese mice, but not in genetically obese ob/ob mice. Stimulation of NOD1 with a synthetic ligand Tri-DAP induces proinflammatory chemokine MCP-1, RANTES, and cytokine TNF-α and MIP-2 (human IL-8 homolog) and IL-6 mRNA expression in 3T3-L1 adipocytes in a time- and dose-dependent manner. Similar proinflammatory profiles are observed in human primary adipocyte culture stimulated with Tri-DAP. Furthermore, NOD1 activation suppresses insulin signaling, as revealed by attenuated tyrosine phosphorylation and increased inhibitory serine phosphorylation, of IRS-1 and attenuated phosphorylation of Akt and downstream target GSK3α/3β, resulting in decreased insulin-induced glucose uptake in 3T3-L1 adipocytes. Together, our results suggest that NOD1 may play an important role in adipose inflammation and insulin resistance in diet-induced obesity.
Ouabain activates the Na-K-ATPase signalosome to induce autosomal dominant polycystic kidney disease cell proliferation
Authors: Nguyen Anh-Nguyet T. , Jansson Kyle , Sánchez Gladis , Sharma Madhulika , Reif Gail A. , Wallace Darren P. , Blanco Gustavo
Published: June 2011

The Na-K-ATPase is part of a cell signaling complex, the Na-K-ATPase signalosome, which upon activation by the hormone ouabain regulates the function of different cell types. We previously showed that ouabain induces proliferation of epithelial cells derived from renal cysts of patients with autosomal dominant polycystic kidney disease (ADPKD cells). Here, we investigated the signaling pathways responsible for mediating the effects of ouabain in these cells. Incubation of ADPKD cells with ouabain, in concentrations similar to those found in blood, stimulated phosphorylation of the epidermal growth factor receptor (EGFR) and promoted its association to the Na-K-ATPase. In addition, ouabain activated the kinase Src, but not the related kinase Fyn. Tyrphostin AG1478 and PP2, inhibitors of EGFR and Src, respectively, blocked ouabain-dependent ADPKD cell proliferation. Treatment of ADPKD cells with ouabain also caused phosphorylation of the caveolar protein caveolin-1, and disruption of cell caveolae with methyl-β-cyclodextrin prevented Na-K-ATPase-EGFR interaction and ouabain-induced proliferation of the cells. Downstream effects of ouabain in ADPKD cells included activation of B-Raf and MEK and phosphorylation of the extracellular regulated kinase ERK, which translocated into the ADPKD cell nuclei. Finally, ouabain reduced expression of the cyclin-dependent kinase inhibitors p21 and p27, which are suppressors of cell proliferation. Different from ADPKD cells, ouabain showed no significant effect on B-Raf, p21, and p27 in normal human kidney epithelial cells. Altogether, these results identify intracellular pathways of ouabain-dependent Na-K-ATPase-mediated signaling in ADPKD cells, including EGFR-Src-B-Raf-MEK/ERK, and establish novel mechanisms involved in ADPKD cell proliferation.
Would an Increase in High‐Skilled Immigration in Canada Benefit Workers?
Authors: Fougère Maxime , Harvey Simon , Rainville Bruno
Published: June 2011

This study examines the economic and welfare effects of raising the number of high‐skilled immigrants in Canada. It uses a life‐cycle applied general equilibrium model with endogenous time allocation decisions between work, education, and leisure. According to the simulation results, raising the number of high‐skilled immigrants would boost productive capacity and labour productivity but could lower real GDP per capita. In addition, by raising the supply of high‐skilled workers, more high‐skilled immigrants would reduce the skill premium and the return to human capital. This in turn would lower incentives for young adults to invest in human capital and have a dampening effect on the domestic supply of skilled workers. Finally, it is found that more high‐skilled immigrants would be welfare enhancing for medium‐ and low‐skilled workers but welfare decreasing for high‐skilled workers.
Pulmonary Edema in Healthy Subjects in Extreme Conditions
Authors: Garbella Erika , Catapano Giosuè , Pratali Lorenza , Pingitore Alessandro
Published: June 2011

There are several pieces of evidence showing occurrence of pulmonary edema (PE) in healthy subjects in extreme conditions consisting of extreme psychophysical demand in normal environment and psychophysical performances in extreme environment. A combination of different mechanisms, such as mechanical, hemodynamic, biochemical, and hypoxemic ones, may underlie PE leading to an increase in lung vascular hydrostatic pressure and lung vascular permeability and/or a downregulation of the alveolar fluid reabsorption pathways. PE can be functionally detected by closing volume measurement and lung diffusing capacity test to different gases or directly visualized by multiple imaging techniques. Among them chest ultrasonography can detect and quantify the extravascular lung water, creating “comet-tail” ultrasound artefacts (ULCs) from water-thickened pulmonary interlobular septa. In this paper the physiopathological mechanisms of PE, the functional and imaging techniques applied to detect and quantify the phenomenon, and three models of extreme conditions, that is, ironman athletes, climbers and breath-hold divers, are described.
Existence of Nonoscillatory Solutions of First‐Order Neutral Differential Equations
Authors: Dorociaková Božena , Najmanová Anna , Olach Rudolf
Published: June 2011

This paper contains some sufficient conditions for the existence of
positive solutions which are bounded below and above by positive functions
for the first‐order nonlinear neutral differential equations. These equations
can also support the existence of positive solutions approaching zero at infinity
Prevalence and Assessment of Clinical Management of Sexually Transmitted Infections among Female Sex Workers in Two Cities of India
Authors: Das A. , Prabhakar P. , Narayanan P. , Neilsen G. , Wi T. , Kumta S. , Rao G. , Gangakhedkar R. , Risbud A.
Published: June 2011

Objective. Control of sexually transmitted infections (STIs) among female sex workers (FSWs) is an important strategy to reduce HIV transmission. A study was conducted to determine the prevalence and assess the current clinical management of STIs in India.Methods. FSWs attending three clinics for regular checkups or symptoms were screened for study eligibility. A behavioral questionnaire was administered, clinical examination performed, and laboratory samples collected.Results. 417 study participants reported a mean number of 4.9 (SD 3.5) commercial clients in the last week. 14.6% reported anal sex in the last three months. Consistent condom use with commercial and regular partners was 70.1% and 17.5%, respectively. The prevalence of gonorrhea was 14.1%, chlamydia 16.1%, and trichomoniasis 31.1% with a third of all infections being asymptomatic. Syphilis seropositivity was 10.1%.Conclusions. At study sites, presumptive treatment for gonorrhea, chlamydia, and syphilis screening should continue. Presumptive treatment for trichomoniasis should be considered. Consistent condom use and partner treatment need to be reemphasized.
An Approximate Bayesian Method Applied to Estimating the Trajectories of Four British Grey Seal (Halichoerus grypus) Populations from Pup Counts
Authors: Lonergan Mike , Thompson Dave , Thomas Len , Duck Callan
Published: June 2011

For British grey seals, as with many pinniped species, population monitoring is implemented by aerial surveys of pups at breeding colonies. Scaling pup counts up to population estimates requires assumptions about population structure; this is straightforward when populations are growing exponentially but not when growth slows, since it is unclear whether density dependence affects pup survival or fecundity. We present an approximate Bayesian method for fitting pup trajectories, estimating adult population size and investigating alternative biological models. The method is equivalent to fitting a density-dependent Leslie matrix model, within a Bayesian framework, but with the forms of the density-dependent effects as outputs rather than assumptions. It requires fewer assumptions than the state space models currently used and produces similar estimates. We discuss the potential and limitations of the method and suggest that this approach provides a useful tool for at least the preliminary analysis of similar datasets.
Development and Validation of a Reduced DME Mechanism Applicable to Various Combustion Modes in Internal Combustion Engines
Authors: Chin Gregory T. , Chen J.-Y. , Rapp Vi H. , Dibble R. W.
Published: June 2011

A 28‐species reduced chemistry mechanism for Dimethyl Ether (DME) combustion is developed on the basis of a recent detailed mechanism by Zhao et al. (2008). The construction of reduced chemistry was carried out with automatic algorithms incorporating newly developed strategies. The performance of the reduced mechanism is assessed over a wide range of combustion conditions anticipated to occur in future advanced piston internal combustion engines, such as HCCI, SAHCCI, and PCCI. Overall, the reduced chemistry gives results in good agreement with those from the detailed mechanism for all the combustion modes tested. While the detailed mechanism by Zhao et al. (2008) shows reasonable agreement with the shock tube autoignition delay data, the detailed mechanism requires further improvement in order to better predict HCCI combustion under engine conditions.
Primary Colorectal Adenocarcinoma Metastatic to the Breast: Case Report and Review of Nineteen Cases
Authors: Shackelford Rodney E. , Allam-Nandyala Pushpa , Bui Marilyn M. , Kiluk John V. , Esposito Nicole Nicosia
Published: June 2011

Metastases to the breast from extramammary primaries are uncommon and account for 0.5–6% of all breast malignancies (Georgiannos et al., 2001, and Vizcaíno et al., 2001). Malignant melanoma, lymphoma, and lung and gastric carcinomas are the most frequently encountered nonmammary metastases to the breast in adults (Georgiannos et al., 2001, and Chaignaud et al., 1994). Primary colorectal adenocarcinoma (CRC) metastatic to the breast is extremely rare, with the medical literature having only 19 recorded cases. Typically CRC metastatic to the breast is indicative of widely disseminated disease and a poor prognosis. Here we present a case of poorly differentiated colon cancer metastatic to the breast and review the current literature on this rare event.
Towards Support for Software Model Checking: Improving the Efficiency of Formal Specifications
Authors: Salamah Salamah , Gates Ann Q. , Roach Steve , Engskow Matthew
Published: June 2011

The Property Specification (Prospec) tool uses patterns and scopes defined by Dwyer et al., to generate formal specifications in Linear Temporal Logic (LTL) and other languages. The work
presented in this paper provides improved LTL specifications for patterns and scopes over those originally provided by Prospec. This improvement comes in the efficiency of the LTL formulas as measured in terms of the number of states in the Büchi automaton generated for the formula. Minimizing the size of the Büchi automata for an LTL specification provides a significant improvement for model checking software systems using such tools as the highly acclaimed Spin model checker.
The Effect of Metformin on the Myocardial Tolerance to Ischemia-Reperfusion Injury in the Rat Model of Diabetes Mellitus Type II
Authors: Kravchuk Ekaterina , Grineva Elena , Bairamov Alekber , Galagudza Michael , Vlasov Timur
Published: June 2011

In recent years, evidence has been accumulated that metformin, an antidiabetic drug in the biguanide class, in addition to its well-recognized glucose-lowering effect, can also reduce cardiovascular mortality in the patients with type 2 diabetes mellitus (T2DM). Besides, there are a few experimental studies on the possibility of the direct anti-ischemic effect of the drug in both type 1 diabetes mellitus and T2DM. In our study, myocardial tolerance to ischemia in rats with neonatal streptozotocin T2DM was investigated using the model of global ischemia-reperfusion of the isolated perfused heart. Metformin was administered i.p. at a dose of 200 mg/kg/day for 3 days prior to isolated heart perfusion. The results showed that both the infarct size and postischemic recovery of left ventricular function were not different between controls and metformin-treated animals. At the same time, the infarct size in the T2DM animals was significantly lower than that in the controls (24.4 ± 7.6% versus 45.0 ± 10.4%, resp.,P<.01), indicative of the metabolic preconditioning in T2DM. It follows that the protocol of metformin administration used in this study had not elicited cardioprotective effect in animals with T2DM so that the different mechanism(s) may underlie the beneficial effect of metformin on cardiovascular complications in patients with T2DM which, however, would need further investigation.
Imatinib Sensitivity in BCR-ABL1–Positive Chronic Myeloid Leukemia Cells Is Regulated by the Remaining Normal ABL1 Allele
Authors: Virgili Anna , Koptyra Mateusz , Dasgupta Yashodhara , Glodkowska-Mrowka Eliza , Stoklosa Tomasz , Nacheva Elisabeth P. , Skorski Tomasz
Published: June 2011

Chronic myeloid leukemia in chronic phase (CML-CP) cells that harbor oncogenic BCR-ABL1 and normal ABL1 allele often become resistant to the ABL1 kinase inhibitor imatinib. Here, we report that loss of the remaining normal ABL1 allele in these tumors, which results from cryptic interstitial deletion in 9q34 in patients who did not achieve a complete cytogenetic remission (CCyR) during treatment, engenders a novel unexpected mechanism of imatinib resistance. BCR-ABL1–positive Abl1−/− leukemia cells were refractory to imatinib as indicated by persistent BCR-ABL1–mediated tyrosine phosphorylation, lack of BCR-ABL1 protein degradation, increased cell survival, and clonogenic activity. Expression of ABL1 kinase, but not a kinase-dead mutant, restored the antileukemic effects of imatinib in ABL1-negative chronic myelogenous leukemia (CML) cells and in BCR-ABL1–positive Abl1−/− murine leukemia cells. The intracellular concentration of imatinib and expression of its transporters were not affected, although proteins involved in BCR-ABL1 degradation were downregulated in Abl1−/− cells. Furthermore, 12 genes associated with imatinib resistance were favorably deregulated in Abl1−/− leukemia. Taken together, our results indicate that loss of the normal ABL1 kinase may serve as a key prognostic factor that exerts major impact on CML treatment outcomes. Cancer Res; 71(16); 5381–6. ©2011 AACR.
Small RNA Sequencing and Functional Characterization Reveals MicroRNA-143 Tumor Suppressor Activity in Liposarcoma
Authors: Ugras Stacy , Brill Elliott , Jacobsen Anders , Hafner Markus , Socci Nicholas D. , DeCarolis Penelope L. , Khanin Raya , O'Connor Rachael , Mihailovic Aleksandra , Taylor Barry S. , Sheridan Robert , Gimble Jeffrey M. , Viale Agnes , Crago Aimee , Antonescu Cristina R. , Sander Chris , Tuschl Thomas , Singer Samuel
Published: June 2011

Liposarcoma remains the most common mesenchymal cancer, with a mortality rate of 60% among patients with this disease. To address the present lack of therapeutic options, we embarked upon a study of microRNA (miRNA) expression alterations associated with liposarcomagenesis with the goal of exploiting differentially expressed miRNAs and the gene products they regulate as potential therapeutic targets. MicroRNA expression was profiled in samples of normal adipose tissue, well-differentiated liposarcoma, and dedifferentiated liposarcoma by both deep sequencing of small RNA libraries and hybridization-based Agilent microarrays. The expression profiles discriminated liposarcoma from normal adipose tissue and well differentiated from dedifferentiated disease. We defined over 40 miRNAs that were dysregulated in dedifferentiated liposarcomas in both the sequencing and the microarray analysis. The upregulated miRNAs included two cancer-associated species (miR-21 and miR-26a), and the downregulated miRNAs included two species that were highly abundant in adipose tissue (miR-143 and miR-145). Restoring miR-143 expression in dedifferentiated liposarcoma cells inhibited proliferation, induced apoptosis, and decreased expression of BCL2, topoisomerase 2A, protein regulator of cytokinesis 1 (PRC1), and polo-like kinase 1 (PLK1). The downregulation of PRC1 and its docking partner PLK1 suggests that miR-143 inhibits cytokinesis in these cells. In support of this idea, treatment with a PLK1 inhibitor potently induced G2–M growth arrest and apoptosis in liposarcoma cells. Taken together, our findings suggest that miR-143 re-expression vectors or selective agents directed at miR-143 or its targets may have therapeutic value in dedifferentiated liposarcoma. Cancer Res; 71(17); 5659–69. ©2011 AACR.
BARD1 Expression Predicts Outcome in Colon Cancer
Authors: Sporn Judith C. , Hothorn Torsten , Jung Barbara
Published: June 2011

Purpose: BARD1 is a BRCA1-binding partner with tumor suppressive properties. Aberrant splice variants of BARD1 have been detected in various cancers, and it has been postulated that the presence of some splice variants is cancer specific. This is the first study assessing BARD1 expression patterns and correlation with clinical outcome in colon cancer.

Experimental Design: We analyzed colon cancer samples for the occurrence of BARD1 splice variants, characterized novel BARD1 splice variants, and quantified the mRNA expression levels of these isoforms in primary colon cancers and their corresponding normal tissue. We tested the correlation of full-length BARD1 protein expression and clinical outcome in primary colon cancer samples.

Results: In addition to the full-length BARD1 mRNA, we now find 19 distinct BARD1 splice variants in colon cancer. Contrary to previous assumptions, these splice variants also occur in the adjacent normal colon tissue. Although BARD1 splice variants account for a considerable amount of BARD1 mRNA in both cancer and normal colon samples, distinct variants show a cancer-specific regulation pattern. Consistent with its role as tumor suppressor, we further find that the expression of the full-length BARD1 protein predicts outcome in colon cancer and that loss of full-length BARD1 protein is associated with a poor prognosis (P = 0.0002).

Conclusion: Taken together, this is the first report to suggest that BARD1 regulation is an important pathway in colon cancer and that the BARD1 full-length protein may be a useful marker to improve risk stratification in colon cancer patients. Clin Cancer Res; 17(16); 5451–62. ©2011 AACR.
c-MYC Oncoprotein Dictates Transcriptional Profiles of ATP-Binding Cassette Transporter Genes in Chronic Myelogenous Leukemia CD34+ Hematopoietic Progenitor Cells
Authors: Porro Antonio , Iraci Nunzio , Soverini Simona , Diolaiti Daniel , Gherardi Samuele , Terragna Carolina , Durante Sandra , Valli Emanuele , Kalebic Thea , Bernardoni Roberto , Perrod Chiara , Haber Michelle , Norris Murray D. , Baccarani Michele , Martinelli Giovanni , Perini Giovanni
Published: June 2011

Resistance to chemotherapeutic agents remains one of the major impediments to a successful treatment of chronic myeloid leukemia (CML). Misregulation of the activity of a specific group of ATP-binding cassette transporters (ABC) is responsible for reducing the intracellular concentration of drugs in leukemic cells. Moreover, a consistent body of evidence also suggests that ABC transporters play a role in cancer progression beyond the efflux of cytotoxic drugs. Despite a large number of studies that investigated the function of the ABC transporters, little is known about the transcriptional regulation of the ABC genes. Here, we present data showing that the oncoprotein c-MYC is a direct transcriptional regulator of a large set of ABC transporters in CML. Furthermore, molecular analysis carried out in CD34+ hematopoietic cell precursors of 21 CML patients reveals that the overexpression of ABC transporters driven by c-MYC is a peculiar characteristic of the CD34+ population in CML and was not found either in the population of mononuclear cells from which they had been purified nor in CD34+ cells isolated from healthy donors. Finally, we describe how the methylation state of CpG islands may regulate the access of c-MYC to ABCG2 gene promoter, a well-studied gene associated with multidrug resistance in CML, hence, affecting its expression. Taken together, our findings support a model in which c-MYC–driven transcriptional events, combined with epigenetic mechanisms, direct and regulate the expression of ABC genes with possible implications in tumor malignancy and drug efflux in CML. Mol Cancer Res; 9(8); 1054–66. ©2011 AACR.
MicroRNA-138 Modulates DNA Damage Response by Repressing Histone H2AX Expression
Authors: Wang Yemin , Huang Jen-Wei , Li Ming , Cavenee Webster K. , Mitchell Patrick S. , Zhou Xiaofeng , Tewari Muneesh , Furnari Frank B. , Taniguchi Toshiyasu
Published: June 2011

Precise regulation of DNA damage response is crucial for cellular survival after DNA damage, and its abrogation often results in genomic instability in cancer. Phosphorylated histone H2AX (γH2AX) forms nuclear foci at sites of DNA damage and facilitates DNA damage response and repair. MicroRNAs (miRNA) are short, nonprotein-encoding RNA molecules, which posttranscriptionally regulate gene expression by repressing translation of and/or degrading mRNA. How miRNAs modulate DNA damage response is largely unknown. In this study, we developed a cell-based screening assay using ionizing radiation (IR)-induced γH2AX foci formation in a human osteosarcoma cell line, U2OS, as the readout. By screening a library of human miRNA mimics, we identified several miRNAs that inhibited γH2AX foci formation. Among them, miR-138 directly targeted the histone H2AX 3′-untranslated region, reduced histone H2AX expression, and induced chromosomal instability after DNA damage. Overexpression of miR-138 inhibited homologous recombination and enhanced cellular sensitivity to multiple DNA-damaging agents (cisplatin, camptothecin, and IR). Reintroduction of histone H2AX in miR-138 overexpressing cells attenuated miR-138–mediated sensitization to cisplatin and camptothecin. Our study suggests that miR-138 is an important regulator of genomic stability and a potential therapeutic agent to improve the efficacy of radiotherapy and chemotherapy with DNA-damaging agents. Mol Cancer Res; 9(8); 1100–11. ©2011 AACR.
Methyl-Binding Domain Protein 2–Dependent Proliferation and Survival of Breast Cancer Cells
Authors: Mian Omar Y. , Wang Shou Zhen , Zhu Sheng Zu , Gnanapragasam Merlin N. , Graham Laura , Bear Harry D. , Ginder Gordon D.
Published: June 2011

Methyl cytosine binding domain protein 2 (MBD2) has been shown to bind to and mediate repression of methylated tumor suppressor genes in cancer cells, where repatterning of CpG methylation and associated gene silencing is common. We have investigated the role of MBD2 in breast cancer cell growth and tumor suppressor gene expression. We show that stable short hairpin RNA (shRNA)-mediated knockdown of MBD2 leads to growth suppression of cultured human mammary epithelial cancer lines, SK-BR-3, MDA-MB-231, and MDA-MB-435. The peak antiproliferative occurs only after sustained, stable MBD2 knockdown. Once established, the growth inhibition persists over time and leads to a markedly decreased propensity for aggressive breast cancer cell lines to form in vivo xenograft tumors in Bagg Albino (BALB)/C nu/nu mice. The growth effects of MBD2 knockdown are accompanied by derepression of tumor suppressor genes, including DAPK1 and KLK10. Chromatin immunoprecipitation assays and bisulfite sequencing show MBD2 binding directly to the hyper methylated and CpG-rich promoters of both DAPK1 and KLK10. Remarkably, the promoter CpG island–associated methylation of these genes remained stable despite robust transcriptional activation in MBD2 knockdown cells. Expression of a shRNA-resistant MBD2 protein resulted in restoration of growth and resilencing of the MBD2-dependent tumor suppressor genes. Our data suggest that uncoupling CpG methylation from repressive chromatin remodeling and histone modifications by removing MBD2 is sufficient to initiate and maintain tumor suppressor gene transcription and suppress neoplastic cell growth. These results show a role for MBD2 in cancer progression and provide support for the prospect of targeting MBD2 therapeutically in aggressive breast cancers. Mol Cancer Res; 9(8); 1152–62. ©2011 AACR.
Neurodevelopmental Outcomes at 18 Months’ Corrected Age of Infants Born at 22 Weeks of Gestation
Authors: Sugiura Tokio , Kouwaki Masanori , Togawa Yasuko , Sugimoto Mari , Togawa Takao , Koyama Norihisa
Published: June 2011

Background: Increased survival rates for extremely low birth weight infants have been reported. However, survival rates and prognoses of extremely preterm infants, such as infants born at 22 weeks of gestation, are still poor. Objective: To investigate such infants’ long-term outcomes, developmental assessments were performed. Methods: Seven infants with gestational age of 22 weeks were delivered in our hospital from 2005 to 2008. One infant was a stillbirth despite resuscitation in the delivery room. Six infants, 4 boys and 2 girls, with a gestational age of 22 weeks (range 223/7–226/7 weeks), were admitted to the neonatal intensive care unit (NICU). Birth weights ranged from 514 to 710 g. None of the infants suffered from sepsis, necrotizing enterocolitis, or severe intraventricular hemorrhage. Results:The survival rate was 85.7% (6/7) as a percentage of deliveries and 100% (6/6) as a percentage of NICU admissions. None of the infants suffered from deafness, blindness, cerebral palsy, or epilepsy. Six infants were available for developmental assessments at 18 months’ corrected age. Three infants showed normal developmental quotients, and 3 infants showed developmental delay. Conclusion: In our study, all infants admitted to the NICU at a gestational age of 22 weeks were discharged from the hospital alive. This might suggest that infants after 22 weeks’ gestation be considered eligible for active treatment in Japan, though considering the size of the material, generalizibility of the results cannot be considered guaranteed.
Inhibitory Effects of SU5416, a Selective Vascular Endothelial Growth Factor Receptor Tyrosine Kinase Inhibitor, on Experimental Corneal Neovascularization
Authors: Keskin Uğurcan , Totan Yüksel , Karadağ Remzi , Erdurmuş Mesut , Aydın Bahri
Published: June 2011

Purpose: Treatment of neovascularization in ocular diseases with vascular endothelial growth factor (VEGF) inhibition shows promising results. SU5416 is a low-molecular-weight tyrosine kinase inhibitor. It selectively inhibits the membrane-bound tyrosine kinase activity of VEGF-2 receptor (Flk-1/KDR) and blocks the intracellular signaling process. The aim of this study was to evaluate the effect of SU5416 on corneal neovascularization. Methods: Corneas were cauterized with silver nitrate/potassium nitrate sticks in 20 eyes of 20 BALB/C mice. In the study group (n = 10), SU5416 (25 mg/kg) dissolved in dimethyl sulfoxide was given as an intraperitoneal injection in a single daily dose for 7 days. The other group of 10 mice given intraperitoneal dimethyl sulfoxide alone served as a control group. After 7 days, corneal neovascularization was evaluated using photographs captured by fluorescein angiography. Colored photographs were taken by a biomicroscope with a digital camera. Data were expressed as mean neovascular length and mean number of new vessels for each animal. The values were computed and compared between the groups. Results: The mean burn stimulus intensities were not different between the groups. In the study group, the mean length of the vessels and the mean number of vessels were 0.49 ± 0.05 and 11.20 ± 1.69 mm, respectively. In the control group, the mean length of the vessels and the mean number of the vessels were 0.89 ± 0.11 and 17.80 ± 1.03 mm, respectively. There is a statistically significant difference in the mean length and the mean number of new vessels between the study and control groups (p < 0.001). Conclusion: Selective inhibition of VEGFR-2 (Flk-1/KDR) tyrosine kinase with SU5416 was shown to have an inhibitory effect on corneal neovascularization in this animal model. VEGFR-2 (Flk-1/KDR) tyrosine kinase inhibition may represent a different pathway for treatment of the neovascularization process in ocular pathologies. Fluorescein angiography photographs of new vessels on the cornea may provide a better evaluation of neovascularization than colored images in animal models.