bluuebunny/crossref_metadata_2025 huggingface dataset:
Evolution of solidification microstructure in undercooled Co80Pd20 alloys
Authors: Xu X L , Chen Y Z , Liu F
Published: September 2012

Applying fluxing method, Co80Pd20 alloy melts were undercooled up to 340 K. Evolution of the solidification microstructure of the undercooled alloys was investigated. Within the range of the achieved undercooling (Δ T), two grain refinement events were observed. The first event happens in the range of 50 K<Δ T<265 K, while the second event takes place at Δ T>280 K. Based on experimental investigations and theoretical calculations, the mechanisms of grain refinements were illuminated. The first grain refinement event is induced by the remelting effects involved in the post-recalescence period, resulting in the formation of a spherical grained microstructure. In the narrow transition range of 265 K<Δ T<280 K, the microstructure is occupied by a mixture of coarse dendrites with equiaxed grains. When Δ T is higher than 280 K, which is rather above the hypercooling limit, recrystallisation of the rapidly solidified solid happens and leads to the formation of an equiaxed grained microstructure.
Effects of extrusion ratio on microstructure, mechanical and corrosion properties of biodegradable Mg–Nd–Zn–Zr alloy
Authors: Zhang X B , Yuan G Y , Wang Z Z
Published: September 2012

The Mg–3·08Nd–0·27Zn–0·46Zr (wt-%) alloy was hot extruded with different extrusion ratios to refine microstructure and to optimise mechanical properties and corrosion resistance as a biodegradable magnesium alloy. The microstructure was observed by optical microscopy, the mechanical properties were tested at room temperature and the corrosion resistance was evaluated in Hanks’ solution. The results show that the microstructure becomes more and more homogeneous with increasing the extrusion ratio. The mechanical properties of the as extruded alloy are much better than those of the as cast one. Higher strength is obtained with the extrusion ratio of 18, and better elongation is obtained with the extrusion ratio of 25. Corrosion results show that corrosion resistance of the as extruded alloy immersed in Hanks’ solution is better than that of the as cast one, and higher extrusion ratio results in better corrosion resistance. Both the as cast and the as extruded alloys exhibit uniform corrosion, which was interpreted by cyclic polarisation test.
Dietary vegetable oils do not alter the intestine transcriptome of gilthead sea bream (Sparus aurata), but modulate the transcriptomic response to infection with Enteromyxum leei
Authors: Calduch-Giner Josep A , Sitjà-Bobadilla Ariadna , Davey Grace C , Cairns Michael T , Kaushik Sadasivam , Pérez-Sánchez Jaume
Published: September 2012

Background

Studies conducted with gilthead sea bream (Sparus aurata L.) have determined the maximum dietary replacement of fish meal and oil without compromising growth or product quality. The present study aimed to analyze the effect of the nutritional background on fish health and fish fed plant protein-based diets with fish oil (FO diet) or a blend of vegetable oils (66VO diet) were exposed for 102 days to the intestinal myxosporean parasite Enteromyxum leei, and the intestine transcriptome was analyzed with a customized oligo-microarray of 7,500 annotated genes.

Results

Infection prevalence was high and similar in the two diet groups, but the outcome of the disease was more pronounced in fish fed the 66VO diet. No differences were found in the transcriptome of both diet control groups, whereas the number of differentially expressed genes in infected groups was considerable. K-means clustering of these differentially expressed genes identified four expression patterns that reflected the progression of the disease with the magnitude of the fold-change being higher in infected 66VO fish. A positive correlation was found between the time of infection and the magnitude of the transcriptional change within the 66VO group, being higher in early infected animals. Within this diet group, a strong up-regulation of many components of the immune specific response was evidenced, whereas other genes related to complement response and xenobiotic metabolism were down-regulated.

Conclusions

The high replacement of fish oil by vegetable oils in practical fish feeds did not modify the intestine transcriptome of gilthead sea bream, but important changes were apparent when fish were exposed to the myxosporean E. leei. The detected changes were mostly a consequence rather than a cause of the different disease progression in the two diet groups. Hence, the developed microarray constitutes an excellent diagnostic tool to address changes associated with the action of intestinal pathogens, but lacks a prognostic value to predict in advance the different susceptibility of growing fish to the current pathogen.
RNA-Seq reveals complex genetic response to deepwater horizon oil release in Fundulus grandis
Authors: Garcia Tzintzuni I , Shen Yingjia , Crawford Douglas , Oleksiak Marjorie F , Whitehead Andrew , Walter Ronald B
Published: September 2012

Background

The release of oil resulting from the blowout of the Deepwater Horizon (DH) drilling platform was one of the largest in history discharging more than 189 million gallons of oil and subject to widespread application of oil dispersants. This event impacted a wide range of ecological habitats with a complex mix of pollutants whose biological impact is still not yet fully understood. To better understand the effects on a vertebrate genome, we studied gene expression in the salt marsh minnow Fundulus grandis, which is local to the northern coast of the Gulf of Mexico and is a sister species of the ecotoxicological model Fundulus heteroclitus. To assess genomic changes, we quantified mRNA expression using high throughput sequencing technologies (RNA-Seq) in F. grandis populations in the marshes and estuaries impacted by DH oil release. This application of RNA-Seq to a non-model, wild, and ecologically significant organism is an important evaluation of the technology to quickly assess similar events in the future.

Results

Our de novo assembly of RNA-Seq data produced a large set of sequences which included many duplicates and fragments. In many cases several of these could be associated with a common reference sequence using blast to query a reference database. This reduced the set of significant genes to 1,070 down-regulated and 1,251 up-regulated genes. These genes indicate a broad and complex genomic response to DH oil exposure including the expected AHR-mediated response and CYP genes. In addition a response to hypoxic conditions and an immune response are also indicated. Several genes in the choriogenin family were down-regulated in the exposed group; a response that is consistent with AH exposure. These analyses are in agreement with oligonucleotide-based microarray analyses, and describe only a subset of significant genes with aberrant regulation in the exposed set.

Conclusion

RNA-Seq may be successfully applied to feral and extremely polymorphic organisms that do not have an underlying genome sequence assembly to address timely environmental problems. Additionally, the observed changes in a large set of transcript expression levels are indicative of a complex response to the varied petroleum components to which the fish were exposed.
Metagenomic and geochemical characterization of pockmarked sediments overlaying the Troll petroleum reservoir in the North Sea
Authors: Håvelsrud Othilde Elise , Haverkamp Thomas HA , Kristensen Tom , Jakobsen Kjetill S , Rike Anne Gunn
Published: September 2012

Background

Pockmarks (depressions in the seabed) have been discovered throughout the world’s oceans and are often related to hydrocarbon seepage. Although high concentrations of pockmarks are present in the seabed overlaying the Troll oil and gas reservoir in the northern North Sea, geological surveys have not detected hydrocarbon seepage in this area at the present time. In this study we have used metagenomics to characterize the prokaryotic communities inhabiting the surface sediments in the Troll area in relation to geochemical parameters, particularly related to hydrocarbon presence. We also investigated the possibility of increased potential for methane oxidation related to the pockmarks. Five metagenomes from pockmarks and plain seabed sediments were sequenced by pyrosequencing (Roche/454) technology. In addition, two metagenomes from seabed sediments geologically unlikely to be influenced by hydrocarbon seepage (the Oslofjord) were included. The taxonomic distribution and metabolic potential of the metagenomes were analyzed by multivariate analysis and statistical comparisons to reveal variation within and between the two sampling areas.

Results

The main difference identified between the two sampling areas was an overabundance of predominantly autotrophic nitrifiers, especially Nitrosopumilus, and oligotrophic marine Gammaproteobacteria in the Troll metagenomes compared to the Oslofjord. Increased potential for degradation of hydrocarbons, especially aromatic hydrocarbons, was detected in two of the Troll samples: one pockmark sample and one from the plain seabed. Although presence of methanotrophic organisms was indicated in all samples, no overabundance in pockmark samples compared to the Oslofjord samples supports no, or only low level, methane seepage in the Troll pockmarks at the present time.

Conclusions

Given the relatively low content of total organic carbon and great depths of hydrocarbon containing sediments in the Troll area, it is possible that at least part of the carbon source available for the predominantly autotrophic nitrifiers thriving in this area originates from sequential prokaryotic degradation and oxidation of hydrocarbons to CO2. By turning CO2 back into organic carbon this subcommunity could play an important environmental role in these dark oligotrophic sediments. The oxidation of ammonia to nitrite and nitrate in this process could further increase the supply of terminal electron acceptors for hydrocarbon degradation.
Ubiquitin initiates sorting of Golgi and plasma membrane proteins into the vacuolar degradation pathway
Authors: Scheuring David , Künzl Fabian , Viotti Corrado , Yan Melody SanWan , Jiang Liwen , Schellmann Swen , Robinson David G , Pimpl Peter
Published: September 2012

Background

In yeast and mammals, many plasma membrane (PM) proteins destined for degradation are tagged with ubiquitin. These ubiquitinated proteins are internalized into clathrin-coated vesicles and are transported to early endosomal compartments. There, ubiquitinated proteins are sorted by the endosomal sorting complex required for transport (ESCRT) machinery into the intraluminal vesicles of multivesicular endosomes. Degradation of these proteins occurs after endosomes fuse with lysosomes/lytic vacuoles to release their content into the lumen. In plants, some PM proteins, which cycle between the PM and endosomal compartments, have been found to be ubiquitinated, but it is unclear whether ubiquitin is sufficient to mediate internalization and thus acts as a primary sorting signal for the endocytic pathway. To test whether plants use ubiquitin as a signal for the degradation of membrane proteins, we have translationally fused ubiquitin to different fluorescent reporters for the plasma membrane and analyzed their transport.

Results

Ubiquitin-tagged PM reporters localized to endosomes and to the lumen of the lytic vacuole in tobacco mesophyll protoplasts and in tobacco epidermal cells. The internalization of these reporters was significantly reduced if clathrin-mediated endocytosis was inhibited by the coexpression of a mutant of the clathrin heavy chain, the clathrin hub. Surprisingly, a ubiquitin-tagged reporter for the Golgi was also transported into the lumen of the vacuole. Vacuolar delivery of the reporters was abolished upon inhibition of the ESCRT machinery, indicating that the vacuolar delivery of these reporters occurs via the endocytic transport route.

Conclusions

Ubiquitin acts as a sorting signal at different compartments in the endomembrane system to target membrane proteins into the vacuolar degradation pathway: If displayed at the PM, ubiquitin triggers internalization of PM reporters into the endocytic transport route, but it also mediates vacuolar delivery if displayed at the Golgi. In both cases, ubiquitin-tagged proteins travel via early endosomes and multivesicular bodies to the lytic vacuole. This suggests that vacuolar degradation of ubiquitinated proteins is not restricted to PM proteins but might also facilitate the turnover of membrane proteins in the early secretory pathway.
Bmi-1 promotes the aggressiveness of glioma via activating the NF-kappaB/MMP-9 signaling pathway
Authors: Jiang Lili , Wu Jueheng , Yang Yi , Liu Liping , Song Libing , Li Jun , Li Mengfeng
Published: September 2012

Background

The prognosis of human glioma is poor, and the highly invasive nature of the disease represents a major impediment to current therapeutic modalities. The oncoprotein B-cell-specific Moloney murine leukemia virus integration site 1 protein (Bmi-1) has been linked to the development and progression of glioma; however, the biological role of Bmi-1 in the invasion of glioma remains unclear.

Methods

A172 and LN229 glioma cells were engineered to overexpress Bmi-1 via stable transfection or to be silenced for Bmi-1 expression using RNA interfering method. Migration and invasiveness of the engineered cells were assessed using wound healing assay, Transwell migration assay, Transwell matrix penetration assay and 3-D spheroid invasion assay. MMP-9 expression and activity were measured using real-time PCR, ELISA and the gelatin zymography methods. Expression of NF-kappaB target genes was quantified using real-time PCR. NF-kappaB transcriptional activity was assessed using an NF-kappaB luciferase reporter system. Expression of Bmi-1 and MMP-9 in clinical specimens was analyzed using immunohistochemical assay.

Results

Ectopic overexpression of Bmi-1 dramatically increased, whereas knockdown of endogenous Bmi-1 reduced, the invasiveness and migration of glioma cells. NF-kappaB transcriptional activity and MMP-9 expression and activity were significantly increased in Bmi-1-overexpressing but reduced in Bmi-1-silenced cells. The reporter luciferase activity driven by MMP-9 promoter in Bmi-1-overexpressing cells was dependent on the presence of a functional NF-kappaB binding site, and blockade of NF-kappaB signaling inhibited the upregulation of MMP-9 in Bmi-1 overexpressing cells. Furthermore, expression of Bmi-1 correlated with NF-kappaB nuclear translocation as well as MMP-9 expression in clinical glioma samples.

Conclusions

Bmi-1 may play an important role in the development of aggressive phenotype of glioma via activating the NF-kappaB/MMP-9 pathway and therefore might represent a novel therapeutic target for glioma.
Role of Rhizobium endoglucanase CelC2 in cellulose biosynthesis and biofilm formation on plant roots and abiotic surfaces
Authors: Robledo M , Rivera L , Jiménez-Zurdo Jose I , Rivas R , Dazzo F , Velázquez E , Martínez-Molina E , Hirsch Ann M , Mateos Pedro F
Published: September 2012

Background

The synthesis of cellulose is among the most important but poorly understood biochemical processes, especially in bacteria, due to its complexity and high degree of regulation. In this study, we analyzed both the production of cellulose by all known members of the Rhizobiaceae and the diversity of Rhizobium celABC operon predicted to be involved in cellulose biosynthesis. We also investigated the involvement in cellulose production and biofilm formation of celC gene encoding an endoglucanase (CelC2) that is required for canonical symbiotic root hair infection by Rhizobium leguminosarum bv. trifolii.

Results

ANU843 celC mutants lacking (ANU843ΔC2) or overproducing cellulase (ANU843C2+) produced greatly increased or reduced amounts of external cellulose micro fibrils, respectively. Calcofluor-stained cellulose micro fibrils were considerably longer when formed by ANU843ΔC2 bacteria rather than by the wild-type strain, in correlation with a significant increase in their flocculation in batch culture. In contrast, neither calcofluor-stained extracellular micro fibrils nor flocculation was detectable in ANU843C2+ cells. To clarify the role of cellulose synthesis in Rhizobium cell aggregation and attachment, we analyzed the ability of these mutants to produce biofilms on different surfaces. Alteration of wild-type CelC2 levels resulted in a reduced ability of bacteria to form biofilms both in abiotic surfaces and in planta.

Conclusions

Our results support a key role of the CelC2 cellulase in cellulose biosynthesis by modulating the length of the cellulose fibrils that mediate firm adhesion among Rhizobium bacteria leading to biofilm formation. Rhizobium cellulose is an essential component of the biofilm polysaccharidic matrix architecture and either an excess or a defect of this “building material” seem to collapse the biofilm structure. These results position cellulose hydrolytic enzymes as excellent anti-biofilm candidates.
Integrin αvβ3 and CD44 pathways in metastatic prostate cancer cells support osteoclastogenesis via a Runx2/Smad 5/receptor activator of NF-κB ligand signaling axis
Authors: Gupta Aditi , Cao Wei , Chellaiah Meenakshi A
Published: September 2012

Background

Bone loss and pathological fractures are common skeletal complications associated with androgen deprivation therapy and bone metastases in prostate cancer patients. We have previously demonstrated that prostate cancer cells secrete receptor activator of NF-kB ligand (RANKL), a protein essential for osteoclast differentiation and activation. However, the mechanism(s) by which RANKL is produced remains to be determined. The objective of this study is to gain insight into the molecular mechanisms controlling RANKL expression in metastatic prostate cancer cells.

Results

We show here that phosphorylation of Smad 5 by integrin αvβ3 and RUNX2 by CD44 signaling, respectively, regulates RANKL expression in human-derived PC3 prostate cancer cells isolated from bone metastasis. We found that RUNX2 intranuclear targeting is mediated by phosphorylation of Smad 5. Indeed, Smad5 knock-down via RNA interference and inhibition of Smad 5 phosphorylation by an αv inhibitor reduced RUNX2 nuclear localization and RANKL expression. Similarly, knockdown of CD44 or RUNX2 attenuated the expression of RANKL. As a result, conditioned media from these cells failed to support osteoclast differentiation in vitro. Immunohistochemistry analysis of tissue microarray sections containing primary prostatic tumor (grade2-4) detected predominant localization of RUNX2 and phosphorylated Smad 5 in the nuclei. Immunoblotting analyses of nuclear lysates from prostate tumor tissue corroborate these observations.

Conclusions

Collectively, we show that CD44 signaling regulates phosphorylation of RUNX2. Localization of RUNX2 in the nucleus requires phosphorylation of Smad-5 by integrin αvβ3 signaling. Our results suggest possible integration of two different pathways in the expression of RANKL. These observations imply a novel mechanistic insight into the role of these proteins in bone loss associated with bone metastases in patients with prostate cancer.
Sequential depletion of human serum for the search of osteoarthritis biomarkers
Authors: Fernández-Costa Carolina , Calamia Valentina , Fernández-Puente Patricia , Capelo-Martínez José-Luis , Ruiz-Romero Cristina , Blanco Francisco J
Published: September 2012

Background

The field of biomarker discovery, development and application has been the subject of intense interest and activity, especially with the recent emergence of new technologies, such as proteomics-based approaches. In proteomics, search for biomarkers in biological fluids such as human serum is a challenging issue, mainly due to the high dynamic range of proteins present in these types of samples. Methods for reducing the content of most highly abundant proteins have been developed, including immunodepletion or protein equalization. In this work, we report for the first time the combination of a chemical sequential depletion method based in two protein precipitations with acetonitrile and DTT, with a subsequent two-dimensional difference in-gel electrophoresis (2D-DIGE) analysis for the search of osteoarthritis (OA) biomarkers in human serum. The depletion method proposed is non-expensive, of easy implementation and allows fast sample throughput.

Results

Following this workflow, we have compared sample pools of human serum obtained from 20 OA patients and 20 healthy controls. The DIGE study led to the identification of 16 protein forms (corresponding to 14 different proteins) that were significantly (p < 0.05) altered in OA when compared to controls (8 increased and 7 decreased). Immunoblot analyses confirmed for the first time the increase of an isoform of Haptoglobin beta chain (HPT) in sera from OA patients.

Conclusions

Altogether, these data demonstrate the utility of the proposed chemical sequential depletion for the analysis of sera in protein biomarker discovery approaches, exhibit the usefulness of quantitative 2D gel-based strategies for the characterization of disease-specific patterns of protein modifications, and also provide a list of OA biomarker candidates for validation.
Tunability and stability of gold nanoparticles obtained from chloroauric acid and sodium thiosulfate reaction
Authors: Zhang Guandong , Jasinski Jacek B , Howell Justin Lee , Patel Dhruvinkumar , Stephens Dennis P , Gobin Andre M
Published: September 2012

In the quest for producing an effective, clinically relevant therapeutic agent, scalability, repeatability, and stability are paramount. In this paper, gold nanoparticles (GNPs) with precisely controlled near-infrared (NIR) absorption are synthesized by a single-step reaction of HAuCl4 and Na2S2O3 without assistance of additional templates, capping reagents, or seeds. The anisotropy in the shape of gold nanoparticles offers high NIR absorption, making it therapeutically relevant. The synthesized products consist of GNPs with different shapes and sizes, including small spherical colloid gold particles and non-spherical gold crystals. The NIR absorption wavelengths and particle size increase with increasing molar ratio of HAuCl4/Na2S2O3. Non-spherical gold particles can be further purified and separated by centrifugation to improve the NIR-absorbing fraction of particles. In-depth studies reveal that GNPs with good structural and optical stability only form in a certain range of the HAuCl4/Na2S2O3 molar ratio, whereas higher molar ratios result in unstable GNPs, which lose their NIR absorption peak due to decomposition and reassembly via Ostwald ripening. Tuning the optical absorption of the gold nanoparticles in the NIR regime via a robust and repeatable method will improve many applications requiring large quantities of desired NIR-absorbing nanoparticles.
Isolation and characterization of a variant porcine epidemic diarrhea virus in China
Authors: Pan Yongfei , Tian Xiaoyan , Li Wei , Zhou Qingfeng , Wang Dongdong , Bi Yingzuo , Chen Feng , Song Yanhua
Published: September 2012

An outbreak of diarrhea in pigs started in Guangdong, South China in January 2011. Cases were characterized by watery diarrhea, dehydration and vomiting, with 80–100% morbidity and 50–90% mortality in suckling piglets. The causative agent of the diarrhea was ultimately identified as porcine epidemic diarrhea virus (PEDV). In this study, we isolated a PEDV strain designated CHGD-01 from piglet intestines using Vero cell cultures, and its specific cytopathic effects were confirmed in susceptible cells by direct immunofluorescence testing and electron microscopy. The complete genome of CHGD-01 was shown to be 28,035 nucleotides in length, with a similar structure to that of PEDV reference strains. Phylogenetic analyses based on the whole genome revealed that CHGD-01 shared nucleotide sequence identities of 98.2–98.4% with two other Chinese isolates reported in the same year, thus constituting a new cluster. Amino acid sequence analysis based on individual virus genes indicated a close relationship between the spike protein gene of CHGD-01 and the field strain KNU0802 in Korea. Its ORF3 and nucleoprotein genes, however, were divergent from all other sequenced PEDV isolate clusters and therefore formed a new group, suggesting a new variant PEDV isolate in China. Further studies will be required to determine the immunogenicity and pathogenicity of this new variant.
Computational modeling of apoptotic signaling pathways induced by cisplatin
Authors: Hong Ji-Young , Kim Geun-Hong , Kim Jun-Woo , Kwon Soon-Sung , Sato Eisuke F , Cho Kwang-Hyun , Shim Eun Bo
Published: September 2012

Background

Apoptosis is an essential property of all higher organisms that involves extremely complex signaling pathways. Mathematical modeling provides a rigorous integrative approach for analyzing and understanding such intricate biological systems.

Results

Here, we constructed a large-scale, literature-based model of apoptosis pathways responding to an external stimulus, cisplatin. Our model includes the key elements of three apoptotic pathways induced by cisplatin: death receptor-mediated, mitochondrial, and endoplasmic reticulum-stress pathways. We showed that cisplatin-induced apoptosis had dose- and time-dependent characteristics, and the level of apoptosis was saturated at higher concentrations of cisplatin. Simulated results demonstrated that the effect of the mitochondrial pathway on apoptosis was the strongest of the three pathways. The cross-talk effect among pathways accounted for approximately 25% of the total apoptosis level.

Conclusions

Using this model, we revealed a novel mechanism by which cisplatin induces dose-dependent cell death. Our finding that the level of apoptosis was affected by not only cisplatin concentration, but also by cross talk among pathways provides in silico evidence for a functional impact of system-level characteristics of signaling pathways on apoptosis.
Successful treatment of methemoglobinemia in an elderly couple with severe cyanosis: two case reports
Authors: Su Ying-Fu , Lu Li-Hua , Hsu Tai-Hao , Chang Shih-Liang , Lin Rong-Tsung
Published: September 2012

Introduction

Methemoglobinemia should be considered in all cyanotic patients who remain unresponsive to oxygen therapy. Rapid diagnosis is very important in emergency cases. Here, we present the cases of two patients, a married couple, admitted to our hospital with methemoglobinemia after exposure to sodium nitrite.

Case presentation

Two patients, a married couple, presented with methemoglobinemia. The 72-year-old Taiwanese man and 68-year-old Taiwanese woman were referred to our hospital with dizziness and tachypnea. On examination, their mucous membranes were cyanotic, and their blood samples showed the classic ‘chocolate brown’ appearance. The man also reported having experienced twitching of his right arm for a few minutes before arrival at the hospital. The symptoms of both patients failed to improve in response to supplemental oxygen delivered via oxygen masks, although the arterial blood gas data of these patients were normal and their pulse oximetry showed oxyhemoglobin levels of approximately 85%. A carbon monoxide-oximeter showed that the man’s methemoglobin concentration was 48.3%, and the woman’s was 36.4%. Methylene blue (100mg) was administered intravenously to both patients, and their symptoms improved dramatically. They were admitted to the intensive care unit and discharged three days later, without neurological sequelae.

Conclusion

Severe methemoglobinemia is a life-threatening condition and, if untreated, may result in death. Early diagnosis and appropriate antidotal treatment are crucial in treating this emergency situation.
Ets-1 is a transcriptional mediator of oncogenic nitric oxide signaling in estrogen receptor-negative breast cancer
Authors: Switzer Christopher H , Cheng Robert Y-S , Ridnour Lisa A , Glynn Sharon A , Ambs Stefan , Wink David A
Published: September 2012

Introduction

The Ets-1 transcription factor is a candidate breast cancer oncogene that regulates the expression of genes involved in tumor progression and metastasis. Ets-1 signaling has also been linked to the development of a basal-like breast cancer phenotype. We recently described a nitric oxide (NO)-induced gene signature that is associated with poor disease outcome in estrogen receptor-negative (ER-) breast cancer and contains both stem cell-like and basal-like components. Thus, we examined the role of Ets-1 in NO signaling and NO-induced phenotypes in ER- human breast cancer cells.

Methods

Promoter region analyses were performed on genes upregulated in inducible nitric oxide synthase (NOS2) high expressing tumors for Ets-binding sites. In vitro mechanisms were examined in human basal-like breast cancer cells lines. NO signaling effects were studied using either forced NOS2 expression or the use of a chemical NO-donor, diethlylenetriamine NONOate (DETANO).

Results

Promoter region analysis of genes that are up-regulated in human ER-negative breast tumors with high NOS2 expression revealed that the Ets-binding sequence is the only common promoter element present in all of these genes, indicating that Ets-1 is the key transcriptional factor down-stream of oncogenic NOS2-signaling. Accordingly, both forced NOS2 over-expression and exposure to NO-donors resulted in significant Ets-1 transcriptional activation in ER- breast cancer cells. Functional studies showed that NO activated Ets-1 transcriptional activity via a Ras/MEK/ERK signaling pathway by a mechanism that involved Ras S-nitrosylation. RNA knock-down of Ets-1 suppressed NO-induced expression of selected basal-like breast cancer markers such as P-cadherin, S100A8, IL-8 and αβ-crystallin. Additionally, Ets-1 knock-down reduced NO-mediated cellular proliferation, matrix metalloproteinase and cathepsin B activities, as well as matrigel invasion.

Conclusions

These data show that Ets-1 is a key transcriptional mediator of oncogenic NO signaling that promotes the development of an aggressive disease phenotype in ER- breast cancer in an Ets-1 and Ras-dependent manner, providing novel clues of how NOS2 expression in human breast tumors is functionally linked to poor patient survival.
Palmitate Causes Endoplasmic Reticulum Stress and Apoptosis in Human Mesenchymal Stem Cells: Prevention by AMPK Activator
Authors: Lu Jun , Wang Qinghua , Huang Lianghu , Dong Huiyue , Lin Lingjing , Lin Na , Zheng Feng , Tan Jianming
Published: September 2012

Elevated circulating saturated fatty acids concentration is commonly associated with poorly controlled diabetes. The highly prevalent free fatty acid palmitate could induce apoptosis in various cell types, but little is known about its effects on human mesenchymal stem cells (MSCs). Here, we report that prolonged exposure to palmitate induces human bone marrow-derived MSC (hBM-MSC) and human umbilical cord-derived MSC apoptosis. We investigated the role of endoplasmic reticulum (ER) stress, which is known to promote cell apoptosis. Palmitate activated XBP1 splicing, elF2α (eukaryotic translation initiation factor 2α) phosphorylation, and CHOP, ATF4, BiP, and GRP94 transcription in hBM-MSCs. ERK1/2 and p38 MAPK phosphorylation were also induced by palmitate in hBM-MSCs. A selective p38 inhibitor inhibited palmitate activation of the ER stress, whereas the ERK1/2 inhibitors had no effect. The AMP-activated protein kinase activator aminoimidazole carboxamide ribonucleotide blocked palmitate-induced ER stress and apoptosis. These findings suggest that palmitate induces ER stress and ERK1/2 and p38 activation in hBM-MSCs, and AMP-activated protein kinase activator prevents the deleterious effects of palmitate by inhibiting ER stress and apoptosis.
The pig as an experimental model for clinical craniofacial research
Authors: Štembírek J , Kyllar M , Putnová I , Stehlík L , Buchtová M
Published: September 2012

The pig represents a useful, large experimental model for biomedical research. Recently, it has been used in different areas of biomedical research. The aim of this study was to review the basic anatomical structures of the head region in the pig in relation to their use in current research. Attention was focused on the areas that are frequently affected by pathological processes in humans: the oral cavity with teeth, salivary gland, orbit, nasal cavity and paranasal sinuses, maxilla, mandible and temporomandibular joint. Not all of the structures have an equal morphology in the pig and human, and these morphological dissimilarities must be taken into account before choosing the pig as an experimental model for regenerative medicine.
Iron Indices and Intravenous Ferumoxytol: Time to Steady-State
Authors: Kapoian Toros , O'Mara Neeta Bahal , Carreon Myra , Gajary Amelia , Rizkala Adel , Lefavour Gertrude , Sherman Richard A , Walker John
Published: September 2012

Background:

The ongoing nature of iron loss in patients receiving hemodialysis makes it difficult to maintain adequate iron stores without supplementation. The effects of ferumoxytol on iron indices have been measured 35 days after baseline, but no study has assessed indices at earlier points in time.

Objective:

To evaluate the time to transferrin saturation (TSAT) and ferritin stabilization, the point at which TSAT and serum ferritin levels can be accurately measured during a 13-treatment period following a loading dose of ferumoxytol.

Methods:

Ferumoxytol was administered according to the package insert to 15 adults undergoing hemodialysis. Vital signs were recorded before treatment, 30 and 60 minutes after receiving ferumoxytol, and at the end of treatment to monitor for adverse reactions and hemodynamic Instability. Monitoring continued for a 13-treatment period (30 days) after drug administration. Blood was collected throughout the study to measure TSAT, ferritin, hemoglobin (Hb), and C-reactive protein (CRP).

Results:

TSAT values at 14, 21, and 28 days after drug administration were not significantly different from those at 7 days, signifying that TSAT values stabilized by day 7. Serum ferritin values at day 14 were significantly lower than those 7 days after drug administration (p = 0.023). Although serum ferritin values at days 21 and 28 tended to decrease relative to values at day 14, the differences were not statistically significant. Therefore, it appears (hat serum ferritin stabilized by day 14 after drug administration. Mean (SD) Hb values at screening and at end of the study were 11.7 (1.0) g/dL and 12.0 (0.9) g/dL, respectively (p = NS). CRP also did not change significantly throughout the study period.

Conclusions:

Dialysis patients achieve stable iron indices quickly. TSAT stabilized by day 7 and ferritin stabilized 14 days after a loading dose of ferumoxytol 1 g. Adverse effects were minimal and did not necessitate discontinuation of ferumoxylol.
Romidepsin: A Histone Deacetylase Inhibitor for Refractory Cutaneous T-Cell Lymphoma
Authors: Kim Miryoung , Thompson Lisa A , Wenger Sarah D , O'Bryant Cindy L
Published: September 2012

Objective:

To evaluate the efficacy and safety of romidepsin in refractory cutaneous T-cell lymphoma (CTCL).

Data Sources:

An English-language literature search of PubMed and MEDLINE (Nov 2011–April 2012) was performed using the terms romidepsin, CTCL, and depsipeptide (FK228). The National Comprehensive Cancer Network guidelines, American Society of Clinical Oncology abstracts, American Society of Hematology abstracts, clinical trial registry, and prescribing information from the manufacturer were reviewed for additional information.

Study Selection and Data Extraction:

Phase 1 and 2 trials evaluating the efficacy and safety of romidepsin were reviewed with a specific focus on its use in cutaneous T-cell lymphoma. All peer-reviewed articles with clinically relevant information were evaluated for inclusion.

Data Synthesis:

In advanced stage CTCL, single or combination chemotherapy regimen responses are variable and lack durability. Romidepsin is a histone deacetylase inhibitor approved for refractory cutaneous T-cell lymphoma, Romidepsin has shown an improvement in duration of response and pruritus over traditional therapy. In 2 independent Phase 2 trials, romidepsin showed an overall response rate of 34% and durable response of 13–15 months in patients with refractory CTCL. The most frequent toxicities of romidepsin include nausea. vomiting, fatigue, or myelosuppresston. Clinically insignificant QT interval changes have been observed but did not correlate with a decrease in left ventricular ejection fraction, or elevated laboratory markers of myocardial damage.

Conclusions:

Romidepsin is an effective, durable, and well-tolerated single-agent therapy in patients with refractory CTCL and should be considered for formulary addition in this population.
Teplizumab for Treatment of Type 1 Diabetes Mellitus
Authors: Skelley Jessica W , Elmore Lindsey K , Kyle Jeffrey A
Published: September 2012

Objective:

To review the pharmacology, pharmacokinetics, safety, and efficacy of teplizumab and evaluate relevant clinical trial data.

Data Sources:

Searches of MEDLINE, International Pharmaceutical Abstracts, ClinicalTrials.gov, American Diabetes Association scientific posters, and Google Scholar (1966-May 2012) were conducted using the key words teplizumab. anti-CD3 monoclonal antibody, MGA031, and hOKT3γ1 (Ala-Ala). Searches were limited to articles published in English.

Study Selection and Data Extraction:

Clinical trials evaluating teplizumab for type 1 diabetes mellitus (T1DM) published in English were selected from the data sources. All published relevant abstracts were included. References cited in identified articles were used for additional citations.

Data Synthesis:

T1DM accounts for up to 10% of all cases of diabetes mellitus, T1DM is characterized as a chronic and progressive autoimmune disease leading to the destruction of insulin-producing β-cells of the pancreas. Teplizumab is a humanized Fc-mutated anti-CD3 monoclonal antibody that alters the function of the T-lymphocytes that mediate the destruction of the insulin-producing β-cells. While clinical data are limited, both Phase 2 and Phase 3 studies have demonstrated preserved C-peptide response as a measure of insulin production, decreased exogenous insulin use, and improved grycemic control following a 12- to 14-day teplizumab infusion in patients diagnosed with T1DM within the previous 6 weeks. However, 1 Phase 3 trial tailed to find the same benefits in those diagnosed with T1DM within the previous 12 weeks when a lower cumulative teplizumab dose was used. Initial studies indicated that teplizumab is well tolerated, with a self-limiting rash as the most commonly reported adverse effect.

Conclusions:

Teplizumab is an anti-CD3 human monoclonal antibody with promising activity in treatment of patients with T1DM, Results from Phase 3 trials are needed to further determine safety, efficacy, and dosing frequency.
Peroxisome Proliferator-Activated Receptor α Mediates Acute Effects of Palmitoylethanolamide on Sensory Neurons
Authors: Khasabova Iryna A. , Xiong Yee , Coicou Lia G. , Piomelli Daniele , Seybold Virginia
Published: September 2012

The amplitude of the depolarization-evoked Ca2+transient is larger in dorsal root ganglion (DRG) neurons from tumor-bearing mice compared with that of neurons from naive mice, and the change is mimicked by coculturing DRG neurons with the fibrosarcoma cells used to generate the tumors (Khasabova et al., 2007). The effect of palmitoylethanolamide (PEA), a ligand for the peroxisome proliferator-activated receptor α (PPARα), was determined on the evoked-Ca2+transient in the coculture condition. The level of PEA was reduced in DRG cells from tumor-bearing mice as well as those cocultured with fibrosarcoma cells. Pretreatment with PEA, a synthetic PPARα agonist (GW7647), or ARN077, an inhibitor of the enzyme that hydrolyzes PEA, acutely decreased the amplitude of the evoked Ca2+transient in small DRG neurons cocultured with fibrosarcoma cells. The PPARα antagonist GW6471 blocked the effect of each. In contrast, the PPARα agonist was without effect in the control condition, but the antagonist increased the amplitude of the Ca2+transient, suggesting that PPARα receptors are saturated by endogenous ligand under basal conditions. Effects of drugs on mechanical sensitivityin vivoparalleled their effects on DRG neuronsin vitro. Local injection of ARN077 decreased mechanical hyperalgesia in tumor-bearing mice, and the effect was blocked by GW6471. These data support the conclusion that the activity of DRG neurons is rapidly modulated by PEA through a PPARα-dependent mechanism. Moreover, agents that increase the activity of PPARα may provide a therapeutic strategy to reduce tumor-evoked pain.
Group I mGluR-Mediated Inhibition of Kir Channels Contributes to Retinal Müller Cell Gliosis in a Rat Chronic Ocular Hypertension Model
Authors: Ji Min , Miao Yanying , Dong Ling-Dan , Chen Jie , Mo Xiao-Fen , Jiang Shi-Xiang , Sun Xing-Huai , Yang Xiong-Li , Wang Zhongfeng
Published: September 2012

Müller cell gliosis, which is characterized by upregulated expression of glial fibrillary acidic protein (GFAP), is a universal response in many retinal pathological conditions. Whether down-regulation of inward rectifying K+(Kir) channels, which commonly accompanies the enhanced GFAP expression, could contribute to Müller cell gliosis is poorly understood. We investigated changes of Kir currents, GFAP and Kir4.1 protein expression in Müller cells in a rat chronic ocular hypertension (COH) model, and explored the mechanisms underlying Müller cell gliosis. We show that Kir currents and Kir4.1 protein expression in Müller cells were reduced significantly, while GFAP expression was increased in COH rats, and these changes were eliminated by MPEP, a group I metabotropic glutamate receptors (mGluR I) subtype mGluR5 antagonist. In normal isolated Müller cells, the mGluR I agonist (S)-3,5-dihydroxyphenylglycine (DHPG) suppressed the Kir currents and the suppression was blocked by MPEP. The DHPG effect was mediated by the intracellular Ca2+-dependent PLC/IP3-ryanodine/PKC signaling pathway, but the cAMP-PKA pathway was not involved. Moreover, intravitreal injection of DHPG in normal rats induced changes in Müller cells, similar to those observed in COH rats. The DHPG-induced increase of GFAP expression in Müller cells was obstructed by Ba2+, suggesting the involvement of Kir channels. We conclude that overactivation of mGluR5 by excessive extracellular glutamate in COH rats could contribute to Müller cell gliosis by suppressing Kir channels.
Subcellular Synaptic Connectivity of Layer 2 Pyramidal Neurons in the Medial Prefrontal Cortex
Authors: Little Justin P. , Carter Adam G.
Published: September 2012

Pyramidal neurons in the prefrontal cortex (PFC) are important for the control of cognitive and emotional behavior. The medial PFC (mPFC) receives diverse long-range excitatory inputs from the midline thalamus, contralateral mPFC, basolateral amygdala, and ventral hippocampus. While axons from these different regions have distinct distributions in the mPFC, their functional connections at the cellular and subcellular levels remain unknown. Here, we use optogenetics to show that layer 2 pyramidal neurons in acute slices of the mouse mPFC receive excitatory inputs from each of these regions. Using a combination of optogenetics and two-photon microscopy, we then determine the subcellular properties of these inputs. We find that different types of inputs make selective contacts at the levels of both dendrites and spines. Using two-photon uncaging, we show that this subcellular targeting strongly influences synaptic efficacy in these neurons. Together, our results show that functional connectivity is finely tuned, with important implications for signal processing in the mPFC.
Ação de inseticidas sistêmicos no algodoeiro
Authors: Toledo Francisco Ferraz de
Published: September 2012

1. No presente trabalho foram abordados diversos aspectos relacionados com a aplicação dos inseticidas sistêmicos no algodoeiro. 2. A variedade utilizada nas experiências relatadas foi a I. A. Campinas 817 e os ensaios, tanto de laboratório como de campo, foram relacionados em detalhe. 3. Os resultados obtidos mostraram que os sistêmicos utilizados não afetaram, em ensaios com germinador, a capacidade de germinação das sementes. Também os resultados do ensaio de campo indicaram que as plantas, no que se refere ao florescimento, ao número de capulhos, ao pêso, à produção e à capacidade de germinação das sementes bem como às características das fibras, comprimento, uniformidade, resistência, finura, maturidade, porcentagem e índices de fibra e de sementes, não foram afetadas pelos tratamentos. 4. Em face dos dados de germinação concluiu-se que a baixa porcentagem de germinação das sementes, no campo, muitas vêzes observadas após serem elas tratadas pelos sistêmicos, deve ser atribuída a fatôres extranhos ao tratamento e que os sistêmicos estudados não afetaram o desenvolvimento das plantas.
Domácias nas angiospermas: variações na forma e na localização
Authors: Barros Myrthes Apparecida Adâmoli de
Published: September 2012

O presente trabalho versa sobre alguns tipos novos de domácia encontrados em 10 espécies de 10 gêneros, distribuídos por entre 9famílias, e que apresentam variações na forma e localização. As domácias foram encontradas na face inferior das folhas e folíolos, com excessão de Oxalis sp. que se situam na face superior, bem na região de sua inserção com o pecíolo. Os tipos de domácias estudados podem ser assim caracterizados: a) Em "tufo de pêlos" variando quanto à localização: 1. Nos folíolos de Schinus terebinthifolius Raddi, ladeando as nervuras de 2.ª ordem. 2. Nas folhas de Bauhinia forficata Link., na base das nervuras que se irradiam das glândulas. 3. Nas folhas de Hura crepitans L., ladeando os primeiros pares de nervuras secundárias, a partir da base. 4. Nas folhas de Jacaratia dodecaphylla A. DC. formando um anel pelífero na região de inserção dos folíolos. 5. Nas folhas de Plumeria lutea R. P., formando uma fileira de pêlos em ambos os lados da nervura principal. 6. Nas folhas de Fuchsia integrifolia Camb., ladeando a nervura principal até 1/3 de seu comprimento. 7. Nas folhas de Oxalis sp. formando um pincel na região de encontro dos folíolos com o pecíolo. b) Em "fenda", com bordos peliferos e nova localização: 1. Nas folhas de Cedrela mexicana Roem., localizando-se geralmente na axila do 3.° par de nervuras secundárias, ora à esquerda e ora à direita. 2. Em Norantea brasiliensis Choisy., as domácias são pequenas, em grande número, distribuindo-se pela área do limbo, ao longo dos bordos da folha, em duas fileiras ar-queadas. c) Em forma de "cavidades": 1. Na base dos folíolos de Schinus terebinthifolius Raddi. d) Variando quanto à forma e localização: 1. Em Lithraea molleoides Engl., aparecendo como novo tipo de domácia, formada pela curvatura dos ápices das asas do pecíolo na face ventral, originando duas pequenas câmaras conchóides, uma de cada lado. e) Sobre a nervura principal: 1. Nas folhas de Cedrela mexicana Roem, ao longo da nervura principal ocorrem domácias em forma de cavidades razas.
Reconstrucción grupal de cuentos: una instancia para la producción de narrativa
Authors: Manrique María Soledad
Published: September 2012

Este artículo presenta los resultados del estudio de las reconstrucciones grupales de los cuentos leídos en salas de jardín de infantes. Se analizó cualitativamente empleando el método comparativo constante, un corpus de 30 situaciones de lectura de cuentos, de las cuales se consideró el momento posterior a la lectura en el que se reconstruye el cuento grupalmente. Los resultados permitieron distinguir diferentes tipos de reconstrucciones de los cuentos a través de la interacción, de acuerdo a la cantidad y calidad de participación de la maestra y de los niños y de información del texto recuperada: reconstrucciones incompletas, reconstrucciones descriptivas, reconstrucciones-cuestionario, reconstrucciones-debate (focalizadas en la comprensión), reconstrucciones monopolizadas y reconstrucciones completas compartidas. Cada uno de estos tipos, que se describe en función de las operaciones cognitivas que demanda de sus participantes, da cuenta de modos diferentes de apoyar la producción de narrativa oral.