bluuebunny/crossref_metadata_2025 huggingface dataset:
Genetic basis of unstable expression of high gamma-tocopherol content in sunflower seeds
Authors: García-Moreno María J , Fernández-Martínez José M , Velasco Leonardo , Pérez-Vich Begoña
Published: May 2012

Background

Tocopherols are natural antioxidants with both in vivo (vitamin E) and in vitro activity. Sunflower seeds contain predominantly alpha-tocopherol (>90% of total tocopherols), with maximum vitamin E effect but lower in vitro antioxidant action than other tocopherol forms such as gamma-tocopherol. Sunflower germplasm with stable high levels of gamma-tocopherol (>85%) has been developed. The trait is controlled by recessive alleles at a single locus Tph2 underlying a gamma-tocopherol methyltransferase (gamma-TMT). Additionally, unstable expression of increased gamma-tocopherol content in the range from 5 to 85% has been reported. The objective of this research was to determine the genetic basis of unstable expression of high gamma-tocopherol content in sunflower seeds.

Results

Male sterile plants of nuclear male sterile line nmsT2100, with stable high gamma-tocopherol content, were crossed with plants of line IAST-1, with stable high gamma-tocopherol content but derived from a population that exhibited unstable expression of the trait. F2 seeds showed continuous segregation for gamma-tocopherol content from 1.0 to 99.7%. Gamma-tocopherol content in F2 plants (average of 24 individual F3 seeds) segregated from 59.4 to 99.4%. A genetic linkage map comprising 17 linkage groups (LGs) was constructed from this population using 109 SSR and 20 INDEL marker loci, including INDEL markers for tocopherol biosynthesis genes. QTL analysis revealed a major QTL on LG 8 that corresponded to the gamma-TMT Tph2 locus, which suggested that high gamma-tocopherol lines nmsT2100 and IAST-1 possess different alleles at this locus. Modifying genes were identified at LGs 1, 9, 14 and 16, corresponding in most cases with gamma-TMT duplicated loci.

Conclusions

Unstable expression of high gamma-tocopherol content is produced by the effect of modifying genes on tph2

a
allele at the gamma-TMT Tph2 gene. This allele is present in line IAST-1 and is different to allele tph2 present in line nmsT2100, which is not affected by modifying genes. No sequence differences at the gamma-TMT gene were found associated to allelic unstability. Our results suggested that modifying genes are mostly epistatically interacting gamma-TMT duplicated loci.
A national study of socioeconomic status and tuberculosis rates by country of birth, United States, 1996–2005
Authors: Olson Nicole A , Davidow Amy L , Winston Carla A , Chen Michael P , Gazmararian Julie A , Katz Dolores J
Published: May 2012

Background

Tuberculosis (TB) in developed countries has historically been associated with poverty and low socioeconomic status (SES). In the past quarter century, TB in the United States has changed from primarily a disease of native-born to primarily a disease of foreign-born persons, who accounted for more than 60% of newly-diagnosed TB cases in 2010. The purpose of this study was to assess the association of SES with rates of TB in U.S.-born and foreign-born persons in the United States, overall and for the five most common foreign countries of origin.

Methods

National TB surveillance data for 1996–2005 was linked with ZIP Code-level measures of SES (crowding, unemployment, education, and income) from U.S. Census 2000. ZIP Codes were grouped into quartiles from low SES to high SES and TB rates were calculated for foreign-born and U.S.-born populations in each quartile.

Results

TB rates were highest in the quartiles with low SES for both U.S.-born and foreign-born populations. However, while TB rates increased five-fold or more from the two highest to the two lowest SES quartiles among the U.S.-born, they increased only by a factor of 1.3 among the foreign-born.

Conclusions

Low SES is only weakly associated with TB among foreign-born persons in the United States. The traditional associations of TB with poverty are not sufficient to explain the epidemiology of TB among foreign-born persons in this country and perhaps in other developed countries. TB outreach and research efforts that focus only on low SES will miss an important segment of the foreign-born population.
Estimation of plasma apolipoprotein B concentration using routinely measured lipid biochemical tests in apparently healthy Asian adults
Authors: Cho Dong-Sik , Woo Sookyoung , Kim Seonwoo , Byrne Christopher D , Kong Joon-Hyuk , Sung Ki-Chul
Published: May 2012

Background

Increased low-density lipoprotein cholesterol (LDL) concentration is associated with increased risk of coronary heart disease (CHD) but a substantial risk of cardiovascular disease often remains after LDL concentrations have been treated to target. Apolipoprotein B (apo B) is the major apolipoprotein contained within atherogenic lipoproteins such as LDL, and apo B is a more reliable indicator of cardiovascular risk than LDL concentration.

Aim and methods

Our aim was to develop a formula for calculating apo B using lipid biochemistry measurements that are commonly available in clinical practice. We examined the clinical and laboratory data from 73,047 Koreans who underwent a medical health check that included apolipoprotein B concentration. The study sample was randomly divided into a training set for prediction model building and a validation set of equal size. Multivariable linear regression analysis was used to develop a prediction model equation for estimating apo B and to validate the developed model.

Results

The best results for estimating apo B were derived from an equation utilising LDL and triglyceride (TG) concentrations [ApoB = −33.12 + 0.675*LDL + 11.95*ln(tg)]. This equation predicted the apo B result with a concordance correlation coefficient (CCC and 95%CIs) = 0.936 (0.935,0.937)).

Conclusion

Our equation for predicting apo B concentrations from routine analytical lipid biochemistry provides a simple method for obtaining precise information about an important cardiovascular risk marker.
Enhancement of thioredoxin/glutaredoxin-mediated L-cysteine synthesis from S-sulfocysteine increases L-cysteine production in Escherichia coli
Authors: Nakatani Takeshi , Ohtsu Iwao , Nonaka Gen , Wiriyathanawudhiwong Natthawut , Morigasaki Susumu , Takagi Hiroshi
Published: May 2012

Background

Escherichia coli has two L-cysteine biosynthetic pathways; one is synthesized from O-acetyl L-serine (OAS) and sulfate by L-cysteine synthase (CysK), and another is produced via S-sulfocysteine (SSC) from OAS and thiosulfate by SSC synthase (CysM). SSC is converted into L-cysteine and sulfite by an uncharacterized reaction. As thioredoxins (Trx1 and Trx2) and glutaredoxins (Grx1, Grx2, Grx3, Grx4, and NrdH) are known as reductases of peptidyl disulfides, overexpression of such reductases might be a good way for improving L-cysteine production to accelerate the reduction of SSC in E. coli.

Results

Because the redox enzymes can reduce the disulfide that forms on proteins, we first tested whether these enzymes catalyze the reduction of SSC to L-cysteine. All His-tagged recombinant enzymes, except for Grx4, efficiently convert SSC into L-cysteine in vitro. Overexpression of Grx1 and NrdH enhanced a 15-40% increase in the E. coli L-cysteine production. On the other hand, disruption of the cysM gene cancelled the effect caused by the overexpression of Grx1 and NrdH, suggesting that its improvement was due to the efficient reduction of SSC under the fermentative conditions. Moreover, L-cysteine production in knockout mutants of the sulfite reductase genes (ΔcysI and ΔcysJ) and the L-cysteine synthase gene (ΔcysK) each decreased to about 50% of that in the wild-type strain. Interestingly, there was no significant difference in L-cysteine production between wild-type strain and gene deletion mutant of the upstream pathway of sulfite (ΔcysC or ΔcysH). These results indicate that sulfite generated from the SSC reduction is available as the sulfur source to produce additional L-cysteine molecule. It was finally found that in the E. coli L-cysteine producer that co-overexpress glutaredoxin (NrdH), sulfite reductase (CysI), and L-cysteine synthase (CysK), there was the highest amount of L-cysteine produced per cell.

Conclusions

In this work, we showed that Grx1 and NrdH reduce SSC to L-cysteine, and the generated sulfite is then utilized as the sulfur source to produce additional L-cysteine molecule through the sulfate pathway in E. coli. We also found that co-overexpression of NrdH, CysI, and CysK increases L-cysteine production. Our results propose that the enhancement of thioredoxin/glutaredoxin-mediated L-cysteine synthesis from SSC is a novel method for improvement of L-cysteine production.
Vigilin interacts with signal peptide peptidase
Authors: Lu Stephen Hsueh-Jeng , Jeon Amy Hye Won , Schmitt-Ulms Gerold , Qamar Seema , Dodd Roger , McDonald Beth , Li Yi , Meadows William , Cox Katie , Bohm Christopher , Chen Fusheng , Fraser Paul , George-Hyslop Peter St
Published: May 2012

Background

Signal peptide peptidase (SPP), a member of the presenilin-like intra-membrane cleaving aspartyl protease family, migrates on Blue Native (BN) gels as 100 kDa, 200 kDa and 450 kDa species. SPP has recently been implicated in other non-proteolytic functions such as retro-translocation of MHC Class I molecules and binding of misfolded proteins in the endoplasmic reticulum (ER). These high molecular weight SPP complexes might contain additional proteins that regulate the proteolytic activity of SPP or support its non-catalytic functions.

Results

In this study, an unbiased iTRAQ-labeling mass spectrometry approach was used to identify SPP-interacting proteins. We found that vigilin, a ubiquitous multi-KH domain containing cytoplasmic protein involved in RNA binding and protein translation control, selectively enriched with SPP. Vigilin interacted with SPP and both proteins co-localized in restricted intracellular domains near the ER, biochemically co-fractionated and were part of the same 450 kDa complex on BN gels. However, vigilin does not alter the protease activity of SPP, suggesting that the SPP-vigilin interaction might be involved in the non-proteolytic functions of SPP.

Conclusions

We have identified and validated vigilin as a novel interacting partner of SPP that could play an important role in the non-proteolytic functions of SPP. This data adds further weight to the idea that intramembrane-cleaving aspartyl proteases, such as presenilin and SPPs, could have other functions besides the proteolysis of short membrane stubs.
Inflammation-Induced Changes in BKCa Currents in Cutaneous Dorsal Root Ganglion Neurons from the Adult Rat
Authors: Zhang Xiu-Lin , Mok Lee-Peng , Lee Kwan Yeop , Charbonnet Marcel , Gold Michael S
Published: May 2012

Background:

Inflammation-induced sensitization of primary afferents is associated with a decrease in K+ current. However, the type of K+ current and basis for the decrease varies as a function of target of innervation. Because glabrous skin of the rat hindpaw is used often to assess changes in nociception in models of persistent pain, the purpose of the present study was to determine the type and extent to which K+ currents contribute to the inflammation-induced sensitization of cutaneous afferents. Acutely dissociated retrogradely labeled cutaneous dorsal root ganglion neurons from naïve and inflamed (3 days post complete Freund's adjuvant injection) rats were studied with whole cell and perforated patch techniques.

Results:

Inflammation-induced sensitization of small diameter cutaneous neurons was associated with an increase in action potential duration and rate of decay of the afterhyperpolarization. However, no changes in voltage-gated K+ currents were detected. In contrast, Ca2+ modulated iberiotoxin sensitive and paxilline sensitive K+ (BKCa) currents were significantly smaller in small diameter IB4+ neurons. This decrease in current was not associated with a detectable change in total protein levels of the BKCa channel α or β subunits. Single cell PCR analysis revealed a significant change in the pattern of expression of α subunit splice variants and β subunits that were consistent, at least in part, with inflammation-induced changes in the biophysical properties of BKCa currents in cutaneous neurons.

Conclusions:

Results of this study provide additional support for the conclusion that it may be possible, if not necessary to selectively treat pain arising from specific body regions. Because a decrease in BKCa current appears to contribute to the inflammation-induced sensitization of cutaneous afferents, BKCa channel openers may be effective for the treatment of inflammatory pain.
Progress report on the first sub-Saharan Africa trial of newer versus older antihypertensive drugs in native black patients
Authors: Odili Augustine N , Ezeala-Adikaibe Birinus , Ndiaye Mouhamadou B , Anisiuba Benedict C , Kamdem Marius M , Ijoma Chinwuba K , Kaptue Joseph , Boombhi Hilaire J , Kolo Philip M , Shu Elvis N , Thijs Lutgarde , Staessen Jan A , Omotoso Babatunde A , Kingue Samuel , Ba Serigne A , Lemogoum Daniel , M’Buyamba-Kabangu Jean-René , Ulasi Ifeoma I
Published: May 2012

Background

The epidemic surge in hypertension in sub-Saharan Africa is not matched by clinical trials of antihypertensive agents in Black patients recruited in this area of the world. We mounted the Newer versus Older Antihypertensive agents in African Hypertensive patients (NOAAH) trial to compare, in native African patients, a single-pill combination of newer drugs, not involving a diuretic, with a combination of older drugs including a diuretic.

Methods

Patients aged 30 to 69 years with uncomplicated hypertension (140 to 179/90 to 109 mmHg) and ≤2 associated risk factors are eligible. After a four week run-in period off treatment, 180 patients have to be randomized to once daily bisoprolol/hydrochlorothiazide 5/6.25 mg (R) or amlodipine/valsartan 5/160 mg (E). To attain blood pressure <140/<90 mmHg during six months, the doses of bisoprolol and amlodipine should be increased to 10 mg/day with the possible addition of up to 2 g/day α-methyldopa.

Results

At the time of writing of this progress report, of 206 patients enrolled in the run-in period, 140 had been randomized. At randomization, the R and E groups were similar (P ≥ 0.11) with respect to mean age (50.7 years), body mass index (28.2 kg/m2), blood pressure (153.9/91.5 mmHg) and the proportions of women (53.6%) and treatment naïve patients (72.7%). After randomization, in the R and E groups combined, blood pressure dropped by 18.2/10.1 mmHg, 19.4/11.2 mmHg, 22.4/12.2 mmHg and 25.8/15.2 mmHg at weeks two (n = 122), four (n = 109), eight (n = 57), and 12 (n = 49), respectively. The control rate was >65% already at two weeks. At 12 weeks, 12 patients (24.5%) had progressed to the higher dose of R or E and/or had α-methyldopa added. Cohort analyses of 49 patients up to 12 weeks were confirmatory. Only two patients dropped out of the study.

Conclusions

NOAAH (NCT01030458) demonstrated that blood pressure control can be achieved fast in Black patients born and living in Africa with a simple regimen consisting of a single-pill combination of two antihypertensive agents. NOAAH proves that randomized clinical trials of cardiovascular drugs in the indigenous populations of sub-Saharan Africa are feasible.
Chronic modulation of AMP-Kinase, Akt and mTOR pathways by ionizing radiation in human lung cancer xenografts
Authors: Storozhuk Yaryna , Sanli Toran , Hopmans Sarah N , Schultz Carrie , Farrell Tom , Cutz Jean-Claude , Steinberg Gregory R , Wright James , Singh Gurmit , Tsakiridis Theodoros
Published: May 2012

Introduction

Earlier, we showed that in cancer cells, AMP-activated kinase (AMPK) participates in a signal transduction pathway involving ATM-AMPK-p53/p21cip1 which is activated by ionizing radiation (IR) to mediate G2-M arrest and enhanced cytotoxicity. We also observed that AMPK modulates ATM expression and activity and the IR response of the Akt-mTOR pathway. Since the ATM, AMPK and Akt pathways are key targets of novel radio-sensitizing therapeutics, we examined the chronic modultion of expression and activity of those pathways by IR alone in xenograft models of lung cancer.

Methods

Immuno-compromised mice were grafted with human lung A549 and H1299 cells, were treated with a single fraction of 0 or 10 Gy, and left to grow for 8 weeks. Extracted tumors were subjected to lysis and immunoblotting or fixation and immunohistochemical analysis.

Results

IR inhibited significantly xenograft growth and was associated with increased expression of Ataxia Telengiectasia Mutated (ATM) and enhanced phosphorylation of two ATM targets, H2Ax and checkpoint kinase Chk2. Irradiated tumours showed increased total AMPK levels and phosphorylation of AMPK and its substrate Acetyl-CoA Carboxylase (ACC). IR led to enhanced expression and phosphorylation of p53 and cyclin dependent kinase inhibitors p21cip1 and p27kip1. However, irradiated tumours had reduced phosphorylation of Akt, mTOR and it‘s target translation initiation inhibitor 4EBP1. Irradiated xenografts showed reduced microvessel density, reduced expression of CD31 but increased expression of hypoxia-induced factor 1A (HIF1a) compared to controls.

Conclusion

IR inhibits epithelial cancer tumour growth and results in sustained expression and activation of ATM-Chk2, and AMPK-p53/p21cip1/p27kip1 but partial inhibition of the Akt-mTOR signaling pathways. Future studies should examine causality between those events and explore whether further modulation of the AMPK and Akt-mTOR pathways by novel therapeutics can sensitize lung tumours to radiation.
In Italy, healthy life expectancy drop dramatically: from 2004 to 2008 there was a 10 years drop among newborn girls
Authors: Gennaro Valerio , Ghirga Giovanni , Corradi Laura
Published: May 2012

Introduction

In this short essay, we would like to address a severe divergence observed in Italy between Life Expectancy (LE) and Healthy Life Expectancy (Healthy LE) and a unique trend of worsening in Healthy LE, compared to the other European countries. Both issues emerge in recent data by EUROSTAT Report.

Methods

The analysis used by the authors of the EUROSTAT report is based on Sullivan method which combines 2 type of variables: mortality and morbidity data.

Results

While several European countries started to deal with comparable data about LE since 1960, in Italy, analogous data were available for the first time in EUROSTAT Report only in 1985. In Italy, in the period 1985-2008, there was a good progressive increase in L.E., following the best European values. Nevertheless, while until 2004 Italy was among the European best countries in terms of both LE and Healthy LE at birth, four years later in 2008 there was a shocking loss of 10 years of Healthy LE at birth in newborn girls. In the process, they lost their 2-years previous advantage with respect to males (the latter lost only 6 years of Healthy LE, in the same time span). Looking at healthy LE at age 65 in respect to 2004, Italian women in 2008 could expect to live healthy only about 7 years (as much as men) versus the almost 15 years of the European best values (14 years for men).

Conclusions

It is legitimate to wonder why no one official comment has been produced as a reaction after the first year of spectacular decline in Healthy Life Years in Italy: in counter-tendency with European values, from 2004 to 2008 there is a clear evidence of a 10 years drop in Healthy LE among newborn girls. The problem has not been taken into consideration even when the situation clearly appeared to worsen in the following years, dropping 4-6 more years for males and females in 2006 (for newborn babies); two more years of healthy life expectancy have been lost between 2006 and 2007 for each gender. One more year of Healthy Life Expectancy is lost in 2008. And data have not been made available any more, since then, from Italy.
Towards the creation of a flexible classification scheme for voluntarily reported transfusion and laboratory safety events
Authors: Whitehurst Julie M , Schroder John , Leonard Dave , Horvath Monica M , Cozart Heidi , Ferranti Jeffrey
Published: May 2012

Background

Transfusion and clinical laboratory services are high-volume activities involving complicated workflows across both ambulatory and inpatient environments. As a result, there are many opportunities for safety lapses, leading to patient harm and increased costs. Organizational techniques such as voluntary safety event reporting are commonly used to identify and prioritize risk areas across care settings. Creation of functional, standardized safety data structures that facilitate effective exploratory examination is therefore essential to drive quality improvement interventions. Unfortunately, voluntarily reported adverse event data can often be unstructured or ambiguously defined.

Results

To address this problem, we sought to create a “best-of-breed” patient safety classification for data contained in the Duke University Health System Safety Reporting System (SRS). Our approach was to implement the internationally recognized World Health Organization International Classification for Patient Safety Framework, supplemented with additional data points relevant to our organization. Data selection and integration into the hierarchical framework is discussed, as well as placement of the classification into the SRS. We evaluated the impact of the new SRS classification on system usage through comparisons of monthly average report rates and completion times before and after implementation. Monthly average inpatient transfusion reports decreased from 102.1 ± 14.3 to 91.6 ± 11.2, with the proportion of transfusion reports in our system remaining consistent before and after implementation. Monthly average transfusion report rates in the outpatient and homecare environments were not significantly different. Significant increases in clinical lab report rates were present across inpatient and outpatient environments, with the proportion of lab reports increasing after implementation. Report completion times increased modestly but not significantly from a practical standpoint.

Conclusions

A common safety vocabulary can facilitate integration of information from disparate systems and processes to permit meaningful measurement and interpretation of data to improve safety within and across organizations. Formation of a “best-of-breed” classification for voluntary reporting necessitates an internal examination of localized data needs and workflow in order to design a product that enables comprehensive data capture. A team of clinical, safety, and information technology experts is necessary to integrate the data structures into the reporting system. We have found that a “best-of-breed” patient safety classification provides a solid, extensible model for adverse event analysis, healthcare leader communication, and intervention identification.
Mangrove plant, Rhizophora mucronata (Lamk, 1804) mediated one pot green synthesis of silver nanoparticles and its antibacterial activity against aquatic pathogens
Authors: Umashankari Jaganathan , Inbakandan Dhinakarasamy , Ajithkumar Thipramalai T , Balasubramanian Thangavel
Published: May 2012

Background

Biosynthesis of nanoparticles has received increasing attention due to the growing need to develop safe, time-effective and environmentally friendly technologies for nano-materials synthesis. This paper reports the one pot green synthesis of silver nanoparticles (AgNPs) using the leaf bud extract of a mangrove plant, Rhizophora mucronata and their antimicrobial effects against aquatic pathogens. Highly stable AgNPs were synthesized by treating the mangrove leaf bud extract with aqueous silver nitrate solution at 15 psi pressure and 121°C for 5 minutes.

Results

The biosynthesized AgNPs were characterized by UV-visible spectrum, at 426 nm. The X-Ray Diffraction (XRD) pattern revealed the face-centered cubic geometry of AgNPs. Fourier Transform Infra Red (FTIR) spectroscopic analysis was carried out to identify the possible biomolecules responsible for biosynthesis of AgNPs from the leaf bud extract. The size and shape of the well-dispersed AgNPs were documented with the help of High Resolution Transmission Electron Microscopy (HRTEM) with a diameter ranged from 4 to 26 nm. However a maximum number of particles were observed at 4 nm in size. The antibacterial effects of AgNPs were studied against aquatic pathogens Proteus spp., Pseudomonas fluorescens and Flavobacterium spp., isolated from infected marine ornamental fish, Dascyllus trimaculatus.

Conclusion

This study reveals that the biosynthesized AgNPs using the leaf bud extract of a mangrove plant (R. mucronata) were found equally potent to synthetic antibiotics. The size of the inhibition zone increases when the concentration of the AgNPs increased and varies according to species.
Ten-year decrease of acquired methicillin-resistant Staphylococcus aureus (MRSA) bacteremia at a single institution: the result of a multifaceted program combining cross-transmission prevention and antimicrobial stewardship
Authors: Chalfine Annie , Kitzis Marie-Dominique , Bezie Yvonnick , Benali Adel , Perniceni Laurence , Nguyen Jean-Claude , Dumay Marie Françoise , Gonot Jacqueline , Rejasse Gilles , Goldstein Fred , Carlet Jean , Misset Benoît
Published: May 2012

Background

In France, the proportion of MRSA has been over 25% since 2000. Prevention of hospital-acquired (HA) MRSA spread is based on isolation precautions and antibiotic stewardship. At our institution, before 2000, the Infection Disease and the Infection Control teams had failed to reduce HA-MRSA rates.

Objectives and methods

We implemented a multifaceted hospital-wide prevention program and measured the effects on HA-MRSA colonization and bacteremia rates between 2000 and 2009. From 2000 to 2003, active screening and decontamination of ICU patients, hospital wide alcohol based hand rubs (ABHR) use, control of specific classes of antibiotics, compliance audits, and feed-backs to the care providers were successively implemented. The efficacy of the program was assessed by HA-MRSA colonized and bacteremic patient rates per 1000 patient-days in patients hospitalized for more than twenty-four hours.

Results

Compliance with the isolation practices increased between 2000 and 2009. Consumption of ABHR increased from 6.8 L to 27.5 L per 1000 patient-days. The use of antibiotic Defined Daily Doses (DDD) per 1000 patient-days decreased by 31%. HA-MRSA colonization decreased by 84% from 1.09 to 0.17 per 1000 patient-days and HA-MRSA bacteremia by 93%, from 0.15 to 0.01 per 1000 patient-days (p < 10−7 for each rate).

Conclusions

In an area highly endemic for MRSA, a multifaceted prevention program allows for sustainable reduction in HA-MRSA bacteremia rates.
Preclinical and clinical studies of estrogen deprivation support the PDGF/Abl pathway as a novel therapeutic target for overcoming endocrine resistance in breast cancer
Authors: Weigel Marion T , Ghazoui Zara , Dunbier Anita , Pancholi Sunil , Dowsett Mitch , Martin Lesley-Ann
Published: May 2012

Introduction

The majority of breast tumors at primary diagnosis are estrogen receptor positive (ER+). Estrogen (E) mediates its effects by binding to the ER. Therapies targeting the estrogenic stimulation of tumor growth reduce mortality from ER+ breast cancer. However, resistance remains a major clinical problem.

Methods

To identify molecular mechanisms associated with resistance to E-deprivation, we assessed the temporal changes in global gene expression during adaptation to long-term culture of MCF7 human breast cancer cells in the absence of estradiol (E2), long term estrogen deprived (LTED), that leads to recovery of proliferative status and models resistance to an aromatase inhibitor (AI). The expression levels of proteins were determined by western blotting. Proliferation assays were carried out using the dual platelet derived growth factor receptor (PDGFR)/Abelson tyrosine kinase (Abl) inhibitor nilotinib. Luciferase reporter assays were used to determine effects on ER-mediated transactivation. Changes in recruitment of cofactors to the gene regulated by estrogen in breast cancer 1 (GREB1) promoter were determined by chromatin immunoprecipitation (ChIP). Gene expression data were derived from 81 postmenopausal women with ER+ BC pre-treatment and at two-weeks post-treatment with single agent anastrozole in a neoadjuvant trial.

Results

The PDGF/Abl canonical pathway was significantly elevated as early as one week post E-deprivation (P = 1.94 E-04) and this became the top adaptive pathway at the point of proliferative recovery (P = 1.15 E-07). Both PDGFRβ and Abl protein levels were elevated in the LTED cells compared to wild type (wt)-MCF7 cells. The PDGF/Abl tyrosine kinase inhibitor nilotinib, suppressed proliferation in LTED cells in the presence or absence of E. Nilotinib also suppressed ER-mediated transcription by destabilizing the ER and reducing recruitment of amplified in breast cancer-1 (AIB1) and the CREB binding protein (CBP) to the promoter of the E-responsive gene GREB1. High PDGFRβ in primary ER+ breast cancer of 81 patients prior to neoadjuvant treatment with an AI was associated with poorer antiproliferative response. Additionally PDGFRβ expression increased after two weeks of AI therapy (1.25 fold, P = 0.003).

Conclusions

These preclinical and clinical data indicate that the PDGF/Abl signaling pathway merits clinical evaluation as a therapeutic target with endocrine therapy in ER+ breast cancer.
Combining intermediate levels of the Endotoxin Activity Assay (EAA) with other biomarkers in the assessment of patients with sepsis: results of an observational study
Authors: Yaguchi Arino , Yuzawa Junji , Klein David J , Takeda Munekasu , Harada Tomoyuki
Published: May 2012

Introduction

The Endotoxin Activity Assay (EAA) is a useful test to risk stratify patients with severe sepsis and assess for Gram negative infection. However, the significance of intermediate levels of EAA (0.4-0.59) at the bedside has not been well elucidated. The purpose of this study was to interpret intermediate EAA levels in clinical practice.

Methods

This retrospective observational study included all adult patients with suspected sepsis admitted to our medico-surgical intensive care unit (ICU) in whom EAA was measured from July 2008 to September 2011. Data collected included EAA, white blood cell (WBC) count and differential, C-reactive protein (CRP), procalcitonin (PCT) and bacterial cultures. Data were analyzed by comparative statistics.

Results

Two hundred and ten patients were studied. Ninety two (43%) patients had culture documented gram negative infection. Patients with Gram-negative organisms in cultures had significantly higher EAA levels (0.47, IQR 0.27) than those without any Gram-negative organisms in cultures (0.34, IQR 0.22) (p < 0.0001). For patients with intermediate EAA levels (0.40 to 0.59), PCT levels and presence of left shift of WBC significantly differed between patients with Gram negative organisms in their blood or other cultures and those who had no organisms in any of the cultures (4.9 versus 1.7 ng/mL, p < 0.05; 57.9 versus 18.9%, p < 0.0004, respectively).

Conclusions

We confirm that high levels of EAA in our cohort of patients with suspected sepsis are strongly associated with gram negative infection. In those patients with intermediate elevation in EAA levels, use of PCT and WBC differential can provide additional diagnostic value to clinicians at the bedside.
Tools for simulating evolution of aligned genomic regions with integrated parameter estimation
Authors: Varadarajan Avinash , Bradley Robert K , Holmes Ian H
Published: May 2012

Controlled simulations of genome evolution are useful for benchmarking tools. However, many simulators lack extensibility and cannot measure parameters directly from data. These issues are addressed by three new open-source programs: GSIMULATOR (for neutrally evolving DNA), SIMGRAM (for generic structured features) and SIMGENOME (for syntenic genome blocks). Each offers algorithms for parameter measurement and reconstruction of ancestral sequence. All three tools out-perform the leading neutral DNA simulator (DAWG) in benchmarks. The programs are available at http://biowiki.org/SimulationTools.
Selective maintenance of Drosophilatandemly arranged duplicated genes during evolution
Authors: Quijano Carlos , Tomancak Pavel , Lopez-Marti Jesus , Suyama Mikita , Bork Peer , Milan Marco , Torrents David , Manzanares Miguel
Published: May 2012

Background

The physical organization and chromosomal localization of genes within genomes is known to play an important role in their function. Most genes arise by duplication and move along the genome by random shuffling of DNA segments. Higher order structuring of the genome occurs in eukaryotes, where groups of physically linked genes are co-expressed. However, the contribution of gene duplication to gene order has not been analyzed in detail, as it is believed that co-expression due to recent duplicates would obscure other domains of co-expression.

Results

We have catalogued ordered duplicated genes in Drosophila melanogaster, and found that one in five of all genes is organized as tandem arrays. Furthermore, among arrays that have been spatially conserved over longer periods than would be expected on the basis of random shuffling, a disproportionate number contain genes encoding developmental regulators. Using in situ gene expression data for more than half of the Drosophila genome, we find that genes in these conserved clusters are co-expressed to a much higher extent than other duplicated genes.

Conclusions

These results reveal the existence of functional constraints in insects that retain copies of genes encoding developmental and regulatory proteins as neighbors, allowing their co-expression. This co-expression may be the result of shared cis-regulatory elements or a shared need for a specific chromatin structure. Our results highlight the association between genome architecture and the gene regulatory networks involved in the construction of the body plan.
Hominoid chromosomal rearrangements on 17q map to complex regions of segmental duplication
Authors: Cardone Maria Francesca , Jiang Zhaoshi , D'Addabbo Pietro , Archidiacono Nicoletta , Rocchi Mariano , Eichler Evan E , Ventura Mario
Published: May 2012

Background

Chromosomal rearrangements, such as translocations and inversions, are recurrent phenomena during evolution, and both of them are involved in reproductive isolation and speciation. To better understand the molecular basis of chromosome rearrangements and their part in karyotype evolution, we have investigated the history of human chromosome 17 by comparative fluorescence in situ hybridization (FISH) and sequence analysis.

Results

Human bacterial artificial chromosome/p1 artificial chromosome probes spanning the length of chromosome 17 were used in FISH experiments on great apes, Old World monkeys and New World monkeys to study the evolutionary history of this chromosome. We observed that the macaque marker order represents the ancestral organization. Human, chimpanzee and gorilla homologous chromosomes differ by a paracentric inversion that occurred specifically in the Homo sapiens/Pan troglodytes/Gorilla gorilla ancestor. Detailed analyses of the paracentric inversion revealed that the breakpoints mapped to two regions syntenic to human 17q12/21 and 17q23, both rich in segmental duplications.

Conclusion

Sequence analyses of the human and macaque organization suggest that the duplication events occurred in the catarrhine ancestor with the duplication blocks continuing to duplicate or undergo gene conversion during evolution of the hominoid lineage. We propose that the presence of these duplicons has mediated the inversion in the H. sapiens/P. troglodytes/G. gorilla ancestor. Recently, the same duplication blocks have been shown to be polymorphic in the human population and to be involved in triggering microdeletion and duplication in human. These results further support a model where genomic architecture has a direct role in both rearrangement involved in karyotype evolution and genomic instability in human.
Staphylococcus aureus directly activates eosinophils via platelet-activating factor receptor
Authors: Hosoki Koa , Nakamura Akiko , Nagao Mizuho , Hiraguchi Yukiko , Tanida Hisashi , Tokuda Reiko , Wada Hideo , Nobori Tsutomu , Suga Shigeru , Fujisawa Takao
Published: May 2012

Staphylococcus aureus (SA) directly activates eosinophils via PAF receptor to induce degranulation, superoxide, and cytokine production, suggesting that SA colonization has pathological significance in atopic dermatitis.

Colonization by SA is associated with exacerbation of AD. Eosinophilic inflammation is a cardinal pathological feature of AD, but little is known about possible direct interaction between SA and eosinophils. PAFR appears to be involved in phagocytosis of Gram-positive bacteria by leukocytes. The objective of this study was to investigate whether SA directly induces eosinophil effector functions via PAFR in the context of AD pathogenesis. Peripheral blood eosinophils were cultured with heat-killed SA, and EDN release, superoxide generation, and adhesion to fibronectin-coated plates were measured. Cytokines, released in the supernatants, were quantified by multiplex bead immunoassays. FISH-labeled SA was incubated with eosinophils and visualized by confocal laser-scanning microscopy. PAFR-blocking peptide and PAFR antagonists were tested for inhibitory effects on SA-induced reactions. SA induced EDN release and superoxide generation by eosinophils in a dose-dependent manner. IL-5 significantly enhanced SA-induced EDN release. IL-5 and IL-17A significantly enhanced SA-induced superoxide generation. SA enhanced eosinophil adhesion to fibronectin, which was blocked by anti-CD49d, and induced eosinophil secretion of various cytokines/chemokines (IL-2R, IL-9, TNFR, IL-1β, IL-17A, IP-10, TNF-α, PDGF-bb, VEGF, and FGF-basic). After incubation of eosinophils with SA, FISH-labeled SA was visualized in the eosinophilsˈ cytoplasm, indicating phagocytosis. A PAFR-blocking peptide and two PAFR antagonists completely inhibited those reactions. In conclusion, SA directly induced eosinophil activation via PAFR. Blockade of PAFR may be a novel, therapeutic approach for AD colonized by SA.
A novel internalization motif regulates human IFN-γR1 endocytosis
Authors: Yancoski Judith , Sadat Mohammed A , Aksentijevich Nadia , Bernasconi Andrea , Holland Steven M , Rosenzweig Sergio D
Published: May 2012

A new type of internalization domain highly conserved in IFNγ receptors across species, regulates human IFNγR1 endocytosis.

This study tested the hypothesis that the IFN-γR1 287-YVSLI-91 intracellular motif regulates its endocytosis. IFN-γ exerts its biological activities by interacting with a specific cell-surface RC composed of two IFN-γR1 and two IFN-γR2 chains. Following IFN-γ binding and along with the initiation of signal transduction, the ligand and IFN-γR1 are internalized. Two major types of consensus-sorting signals are described in receptors, which are rapidly internalized from the plasma membrane to intracellular compartments: tyrosine-based and dileucine-based internalization motifs. Transfection of HEK 293 cells and IFN-γR1-deficient fibroblasts with WT and site-directed, mutagenesis-generated mutant IFN-γR1 expression vectors helped us to identify region IFN-γR1 287-YVSLI-291 as the critical domain required for IFN-γ-induced IFN-γR1 internalization and Y287 and LI290–291 as part of a common structure essential for receptor endocytosis and function. This new endocytosis motif, YxxLI, shares characteristics of tyrosine-based and dileucine-based internalization motifs and is highly conserved in IFN-γRs across species. The IFN-γR1 270-LI-271 dileucine motif, previously thought to be involved in this receptor endocytosis, showed to be unnecessary for receptor endocytosis.
Dihydrotestosterone Inhibits Lectin-Like Oxidized-LDL Receptor-1 Expression in Aortic Endothelial Cells via a NF-κB/AP-1-Mediated Mechanism
Authors: Qiu Yang , Tanaka Tomoko , Nawata Hajime , Yanase Toshihiko
Published: May 2012

The mechanisms involved in the antiatherosclerotic effects of androgens are unclear. Although lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) in endothelial cells plays critical roles in atherosclerosis, the effects of androgens on endothelial LOX-1 expression has not been examined. Therefore, to investigate the effects of dihydrotestosterone (DHT) on LOX-1 expression in rabbit aortic endothelial cells and cultured human aortic endothelial cells (HAEC), pellets containing DHT or placebo were sc implanted into 26 male New Zealand white rabbits at the time of castration or sham operation. The rabbits were then fed a high-cholesterol diet (HCD) for 2 wk. Microscopic examination of the aortic arch revealed that DHT significantly reduced HCD-induced LOX-1 expression in endothelial cells compared with placebo. In cultured HAEC, DHT at concentrations above 10−9 to 10−7 mol/liter inhibited TNFα-induced LOX-1 mRNA and protein expression. Deletion and mutation analysis of human LOX-1 promoter-luciferase constructs transfected into HAEC with an androgen receptor (AR) expression plasmid revealed that the 12-O-tetradecanoylphorbol-13-acetate (TPA) response element (TRE; nucleotides −60/−53) contributed to the inhibitory effects of DHT on TNFα-induced LOX-1 expression. Chromatin immunoprecipitation (ChIP) and re-ChIP assays revealed that TNFα- and TPA-dependent enrichment of p65 and phosphorylated c-Jun in the TRE chromatin region was inhibited by DHT-AR. Consistent with these results, DHT also suppressed TPA-induced expression of LOX-1. In conclusion, DHT exerts antiatherosclerotic effects by suppressing endothelial LOX-1 expression. This effect is partly mediated by the suppression of nuclear factor-κB- and activator protein 1-dependent activation of the LOX-1 promoter.
Critical Role of Egr Transcription Factors in Regulating Insulin Biosynthesis, Blood Glucose Homeostasis, and Islet Size
Authors: Müller Isabelle , Rössler Oliver G. , Wittig Christine , Menger Michael D. , Thiel Gerald
Published: May 2012

Expression of early growth response protein (Egr)-1, a protein of the Egr family of zinc finger transcription factors, is stimulated in glucose-treated pancreatic β-cells and insulinoma cells. The purpose of this study was to elucidate the role of Egr transcription factors in pancreatic β-cells in vivo. To overcome the problem associated with redundancy of functions between Egr proteins, conditional transgenic mice were generated expressing a dominant-negative mutant of Egr-1 in pancreatic β-cells. The Egr-1 mutant interferes with DNA binding of all Egr proteins and thus impairs the biological functions of the entire Egr family. Expression of the Egr-1 mutant reduced expression of TGFβ and basic fibroblast growth factor, known target genes of Egr-1, whereas the expression of Egr-1, Egr-3, Ets-like gene-1 (Elk-1), and specificity protein-3 was not changed in the presence of the Egr-1 mutant. Expression of the homeobox protein pancreas duodenum homeobox-1, a major regulator of insulin biosynthesis, was reduced in islets expressing the Egr-1 mutant. Accordingly, insulin mRNA and protein levels were reduced by 75 or 25%, respectively, whereas expression of glucagon and somatostatin was not altered after expression of the Egr-1 mutant in β-cells. Glucose tolerance tests revealed that transgenic mice expressing the Egr-1 mutant in pancreatic β-cells displayed impaired glucose tolerance. In addition, increased caspase-3/7 activity was detected as a result of transgene expression, leading to a 20% decrease of the size of the islets. These results show that Egr proteins play an important role in controlling insulin biosynthesis, glucose homeostasis, and islet size of pancreatic β-cells in vivo.
Microtubule-severing enzymes at the cutting edge
Authors: Sharp David J. , Ross Jennifer L.
Published: May 2012

ATP-dependent severing of microtubules was first reported in Xenopus laevis egg extracts in 1991. Two years later this observation led to the purification of the first known microtubule-severing enzyme, katanin. Katanin homologs have now been identified throughout the animal kingdom and in plants. Moreover, members of two closely related enzyme subfamilies, spastin and fidgetin, have been found to sever microtubules and might act alongside katanins in some contexts (Roll-Mecak and McNally, 2010; Yu et al., 2008; Zhang et al., 2007). Over the past few years, it has become clear that microtubule-severing enzymes contribute to a wide range of cellular activities including mitosis and meiosis, morphogenesis, cilia biogenesis and disassembly, and migration. Thus, this group of enzymes is revealing itself to be among the most important of the microtubule regulators. This Commentary focuses on our growing understanding of how microtubule-severing enzymes contribute to the organization and dynamics of diverse microtubule arrays, as well as the structural and biophysical characteristics that afford them the unique capacity to catalyze the removal of tubulin from the interior microtubule lattice. Our goal is to provide a broader perspective, focusing on a limited number of particularly informative, representative and/or timely findings.
Regulation of multiple target genes by miR-1 and miR-206 is pivotal for C2C12 myoblast differentiation
Authors: Goljanek-Whysall Katarzyna , Pais Helio , Rathjen Tina , Sweetman Dylan , Dalmay Tamas , Münsterberg Andrea
Published: May 2012

MicroRNAs are short non-coding RNAs involved in post-transcriptional regulation of multiple messenger RNA targets. The miR-1/miR-206 family is expressed during skeletal muscle differentiation and is an integral component of myogenesis. To better understand miR-1/miR-206 function during myoblast differentiation we identified novel target mRNAs by microarray and characterized their function in C2C12 myoblasts. Candidate targets from the screen were experimentally validated together with target genes that were predicted by three different algorithms. Some targets characterised have a known function in skeletal muscle development and/or differentiation and include Meox2, RARB, Fzd7, MAP4K3, CLCN3 and NFAT5, others are potentially novel regulators of myogenesis, such as the chromatin remodelling factors Smarcd2 and Smarcb1 or the anti-apoptotic protein SH3BGRL3. The expression profiles of confirmed target genes were examined during C2C12 cell myogenesis. We found that inhibition of endogenous miR-1 and miR-206 by antimiRs blocked the downregulation of most targets in differentiating cells, thus indicating that microRNA activity and target interaction is required for muscle differentiation. Finally, we show that sustained expression of validated miR-1 and/or miR-206 targets resulted in increased proliferation and inhibition of C2C12 cell myogenesis. In many cases the expression of genes related to non-muscle cell fates, such as chondrogenesis, was activated. This indicates that the concerted downregulation of multiple microRNA targets is not only crucial to the skeletal muscle differentiation program but also serves to prevent alternative cell fate choices.