bluuebunny/crossref_metadata_2025 huggingface dataset:
Iloprost improves endothelial barrier function in lipopolysaccharide-induced lung injury
Authors: Birukova Anna A. , Wu Tinghuai , Tian Yufeng , Meliton Angelo , Sarich Nicolene , Tian Xinyong , Leff Alan , Birukov Konstantin G.
Published: July 2012

The protective effects of prostacyclin and its stable analogue iloprost are mediated by elevation of intracellular cyclic AMP (cAMP) leading to enhancement of the peripheral actin cytoskeleton and cell–cell adhesive structures. This study tested the hypothesis that iloprost may exhibit protective effects against lung injury and endothelial barrier dysfunction induced by bacterial wall lipopolysaccharide (LPS).

Endothelial barrier dysfunction was assessed by measurements of transendothelial permeability, morphologically and by analysis of LPS-activated inflammatory signalling.In vivo, C57BL/6J mice were challenged with LPS with or without iloprost or 8-bromoadenosine-3′,5′-cyclic monophosphate (Br-cAMP) treatment. Lung injury was monitored by measurements of bronchoalveolar lavage protein content, cell count and Evans blue extravasation.

Iloprost and Br-cAMP attenuated the disruption of the endothelial monolayer, and suppressed the activation of p38 mitogen-activated protein kinase (MAPK), the nuclear factor (NF)-κB pathway, Rho signalling, intercellular adhesion molecular (ICAM)-1 expression and neutrophil migration after LPS challenge.In vivo, iloprost was effective against LPS-induced protein and neutrophil accumulation in bronchoalveolar lavage fluid, and reduced myeloperoxidase activation, ICAM-1 expression and Evans blue extravasation in the lungs. Inhibition of Rac activity abolished the barrier-protective and anti-inflammatory effects of iloprost and Br-cAMP.

Iloprost-induced elevation of intracellular cAMP triggers Rac signalling, which attenuates LPS-induced NF-κB and p38 MAPK inflammatory pathways and the Rho-dependent mechanism of endothelial permeability.
Insulin receptor substrate-1 prevents autophagy-dependent cell death caused by oxidative stress in mouse NIH/3T3 cells
Authors: Chan Shih-Hung , Kikkawa Ushio , Matsuzaki Hidenori , Chen Jyh-Hong , Chang Wen-Chang
Published: July 2012

Background

Insulin receptor substrate (IRS)-1 is associated with tumorigenesis; its levels are elevated in several human cancers. IRS-1 protein binds to several oncogene proteins. Oxidative stress and reactive oxygen species (ROS) are involved in the initiation and progression of cancers. Cancer cells produce greater levels of ROS than normal cells do because of increased metabolic stresses. However, excessive production of ROS kills cancer cells. Autophagy usually serves as a survival mechanism in response to stress conditions, but excessive induction of autophagy results in cell death. In addition to inducing necrosis and apoptosis, ROS induces autophagic cell death. ROS inactivates IRS-1 mediated signaling and reduces intracellular IRS-1 concentrations. Thus, there is a complex relationship between IRS-1, ROS, autophagy, and cancer. It is not fully understood how cancer cells grow rapidly and survive in the presence of high ROS levels.

Methods and results

In this study, we established mouse NIH/3T3 cells that overexpressed IRS-1, so mimicking cancers with increased IRS-1 expression levels; we found that the IRS-1 overexpressing cells grow more rapidly than control cells do. Treatment of cells with glucose oxidase (GO) provided a continuous source of ROS; low dosages of GO promoted cell growth, while high doses induced cell death. Evidence for GO induced autophagy includes increased levels of isoform B-II microtubule-associated protein 1 light chain 3 (LC3), aggregation of green fluorescence protein-tagged LC3, and increased numbers of autophagic vacuoles in cells. Overexpression of IRS-1 resulted in inhibition of basal autophagy, and reduced oxidative stress-induced autophagy and cell death. ROS decreased the mammalian target of rapamycin (mTOR)/p70 ribosomal protein S6 kinase signaling, while overexpression of IRS-1 attenuated this inhibition. Knockdown of autophagy-related gene 5 inhibited basal autophagy and diminished oxidative stress-induced autophagy and cell death.

Conclusion

Our results suggest that overexpression of IRS-1 promotes cells growth, inhibits basal autophagy, reduces oxidative stress-induced autophagy, and diminishes oxidative stress-mediated autophagy-dependent cell death. ROS-mediated autophagy may occur via inhibition of IRS-1/phosphatidylinositol 3-kinase/mTOR signaling. Our data afford a plausible explanation for IRS-1 involvement in tumor initiation and progression.
Growth and characterization of TiO2 nanotubes from sputtered Ti film on Si substrate
Authors: Chappanda Karumbaiah N , Smith York R , Mohanty Swomitra K , Rieth Loren W , Tathireddy Prashant , Misra Mano
Published: July 2012

In this paper, we present the synthesis of self-organized TiO2 nanotube arrays formed by anodization of thin Ti film deposited on Si wafers by direct current (D.C.) sputtering. Organic electrolyte was used to demonstrate the growth of stable nanotubes at room temperature with voltages varying from 10 to 60 V (D.C.). The tubes were about 1.4 times longer than the thickness of the sputtered Ti film, showing little undesired dissolution of the metal in the electrolyte during anodization. By varying the thickness of the deposited Ti film, the length of the nanotubes could be controlled precisely irrespective of longer anodization time and/or anodization voltage. Scanning electron microscopy, atomic force microscopy, diffuse-reflectance UV–vis spectroscopy, and X-ray diffraction were used to characterize the thin film nanotubes. The tubes exhibited good adhesion to the wafer and did not peel off after annealing in air at 350 °C to form anatase TiO2. With TiO2 nanotubes on planar/stable Si substrates, one can envision their integration with the current micro-fabrication technique large-scale fabrication of TiO2 nanotube-based devices.
Content aware optimization for video delivery over WCDMA
Authors: Pandit Kartik , Ghosh Amitabha , Ghosal Dipak , Chiang Mung
Published: July 2012

A content-aware networking framework for transmitting video on the uplink of a Wideband Code Division Multiple Access (WCDMA) cellular network is studied in this article. We consider a multi-user scenario and exploit the underlying structure of the video content to optimally schedule frames in order to minimize the total distortion of video quality across all users. In particular, we propose a novel Content-Aware Distortion Fair (CADF) scheme that determines, between multiple flows, the best set of frames to schedule using optimal transmit power, while meeting interference and delay constraints. The optimization problem is considered on the time scale of a single Group of Pictures, and is formulated as a restricted Multiple Knapsack Problem. A key contribution of this study is evaluating the CADF scheme on a Qualcomm 3G emulator, called “High data rate System Emulator 2” (HSE 2), and conducting rate control experiments with different types of emulated channel conditions. Our experimental results show that the CADF scheme significantly reduces video distortion, compared to the existing Foschini-Miljanic closed-loop distributed power control algorithm implemented on the WCDMA uplink. In the Appendix section, we also use the emulator to analyze the Traffic-to-Pilot resource allocation algorithm implemented on the reverse link of Evolution-Data Optimized (EV-DO) Revision-A by profiling over different traffic classes.
Boundary value problems for the quaternionic Hermitian system in "Equation missing"
Authors: Abreu-Blaya Ricardo , Bory-Reyes Juan , Brackx Fred , De Schepper Hennie , Sommen Frank
Published: July 2012

In this paper boundary value problems for quaternionic Hermitian monogenic functions are presented using a circulant matrix approach.

MSC:30G35.
CD44 rs13347 C>T polymorphism predicts breast cancer risk and prognosis in Chinese populations
Authors: Jiang Lan , Deng Jieqiong , Zhu Xun , Zheng Jian , You Yonghe , Li Na , Wu Hongchun , Lu Jiachun , Zhou Yifeng
Published: July 2012

Introduction

It has been demonstrated that the interplay of adhesion molecule CD44 and its ligands can regulate cancer cell proliferation, migration and invasion, as well as tumor-associated angiogenesis and is related to breast cancer patient survival. In this two-stage, case control study, we determined whether common functional tagSNPs (single nucleotide polymorphisms) are associated with breast cancer risk and prognosis.

Methods

Five tagSNPs of CD44 (rs10836347C>T, rs13347C>T, rs1425802A>G, rs11821102G>A, rs713330T>C) were selected and genotyped in 1,853 breast cancer patients and 1,992 healthy control subjects in Eastern and Southern populations. Potential function of rs13347C>T and association between this variation and breast cancer were further studied.

Results

Compared with the most common rs13347CC genotype, variant genotypes (CT and TT) increased an individual's susceptibility to breast cancer, especially in estrogen receptor (ER) negative patients (odds ratio (OR) = 1.37, 95%CI = 1.17 to 1.59 for ER positive patients; OR = 2.37, 95% CI = 2.00 to 2.80 for ER negative patients). We also found that rs13347CT+ TT genotypes predicts lower five-year survival rate (hazard ratio (HR) = 1.85, 95% CI = 1.09 to 3.15, P = 0.023), with the lowest survival probability in ER negative T allele carriers. Furthermore, our reporter assay findings, although preliminary and rather modest, showed that miR-509-3p may suppress CD44 expression more strongly in C allele carriers than T allele carriers (P < 0.01). Similarly, rs13347 variant genotypes (CT and TT) carriers were shown to have more CD44 expression than CC carriers in both immunohistochemistry (P < 0.001) and western blotting (P = 0.001) results.

Conclusion

These findings suggest that CD44 rs13347C>T polymorphism may affect breast cancer development and prognosis by increasing CD44 expression.
Human pituitary tumor-transforming gene 1 overexpression reinforces oncogene-induced senescence through CXCR2/p21 signaling in breast cancer cells
Authors: Ruan Jhen-Wei , Liao Yi-Chu , Lua Ingrid , Li Ming-Hsun , Hsu Chih-Yi , Chen Ji-Hshiung
Published: July 2012

Introduction

hPTTG1 (human pituitary tumor-transforming gene 1) is an oncogene overexpressed in breast cancer and several other types of cancer. Increased hPTTG1 expression has been shown to be associated with poor patient outcomes in breast cancer. Although hPTTG1 overexpression plays important roles in promoting the proliferation, invasion, and metastasis of cancer cells, it also has been suggested to induce cellular senescence. Deciphering the mechanism by which hPTTG1 overexpression induces these contradictory actions in breast cancer cells is critical to our understanding of the role of hPTTG1 in breast cancer development.

Methods

MCF-10A and MCF-7 cells were used to identify the mechanism of hPTTG1-induced senescence. The interplay between hPTTG1 overexpression and chemokine C-X-C motif receptor 2 (CXCR2)/p21-dependent senescence in tumor growth and metastasis of MCF-7 cells was investigated by orthotopic transplantation of severe combined immunodeficiency (SCID) mice. Additionally, human invasive ductal carcinoma (IDC) tissue arrays were used to confirm the hPTTG1/CXCR2/p21 axis established in vitro.

Results

In this study, we investigated the mechanism of hPTTG1-induced senescence as well as its role in breast cancer progression and metastasis. Herein, we showed that hPTTG1 overexpression reinforced senescence through the CXCR2/p21 signaling. Furthermore, hPTTG1 overexpression activated NF-κB signaling to transactivate the expression of interleukin (IL)-8 and growth-regulated oncogene alpha (GROα) to execute CXCR2 signaling in MCF-7 cells. When CXCR2 expression was knocked down in hPTTG1-overexpressing MCF-7 cells, hPTTG1-induced senescence was abrogated by alleviating CXCR2-induced p21 expression. In a mouse model, CXCR2-mediated senescence limited hPTTG1-induced tumor growth and metastasis. Moreover, CXCR2 knockdown in hPTTG1-overexpressing MCF-7 tumors dramatically accelerated tumor growth and metastasis. Our in vitro and in vivo results demonstrated that hPTTG1 overexpression reinforces senescence through CXCR2 signaling, and the evasion of CXCR2/p21-dependent senescence was critical to hPTTG1 exerting its oncogenic potential. Interestingly, although CXCR2-dependent senescence restrained hPTTG1-induced tumor progression, when MCF-7 cells and hPTTG1-overexpressing MCF-7 cells were co-transplanted into the mammary fat pads of SCID mice, hPTTG1-overexpressing senescent cells created a metastasis-promoting microenvironment that promoted lung metastasis of the MCF-7 cells. Immunohistochemical analysis of human breast tumor samples also confirmed the importance of the hPTTG1/CXCR2 axis in promoting breast cancer metastasis.

Conclusions

Our findings provide novel molecular insights into hPTTG1-induced senescence and identify a novel mechanism by which hPTTG1 promotes metastasis by regulating the senescence-associated microenvironment.
1D single-site and laterally constrained inversion of multifrequency and multicomponent ground-based electromagnetic induction data — Application to the investigation of a near-surface clayey overburden
Authors: Schamper Cyril , Rejiba Fayçal , Guérin Roger
Published: July 2012

Electromagnetic induction (EMI) methods are widely used to determine the distribution of the electrical conductivity and are well adapted to the delimitation of aquifers and clayey layers because the electromagnetic field is strongly perturbed by conductive media. The multicomponent EMI device that was used allowed the three components of the secondary magnetic field (the radial [Formula: see text], the tangential [Formula: see text], and the vertical [Formula: see text]) to be measured at 10 frequencies ranging from 110 to 56 kHz in one single sounding with offsets ranging from 20 to 400 m. In a continuing endeavor to improve the reliability with which the thickness and conductivity are inverted, we focused our research on the use of components other than the vertical magnetic field Hz. Because a separate sensitivity analysis of [Formula: see text] and [Formula: see text] suggests that [Formula: see text] is more sensitive to variations in the thickness of a near-surface conductive layer, we developed an inversion tool able to make single-sounding and laterally constrained 1D interpretation of both components jointly, associated with an adapted random search algorithm for single-sounding processing for which almost no a priori information is available. Considering the complementarity of [Formula: see text] and [Formula: see text] components, inversion tests of clean and noisy synthetic data showed an improvement in the definition of the thickness of a near-surface conductive layer. This inversion code was applied to the karst site of the basin of Fontaine-Sous-Préaux, near Rouen (northwest of France). Comparison with an electrical resistivity tomography tends to confirm the reliability of the interpretation from the EMI data with the developed inversion tool.
Childhood psychosocial adversity and adult cortisol patterns
Authors: Power Chris , Thomas Claudia , Li Leah , Hertzman Clyde
Published: July 2012

Background

Cortisol levels may be altered in childhood in association with maltreatment (neglect, abuse and witnessing abuse) and other adversities, yet little is known about whether effects on cortisol persist into later life.

Aims

To establish whether childhood psychosocial adversities predict cortisol levels in mid-adulthood.

Method

Childhood psychosocial adversities were ascertained in the 1958 British birth cohort and cortisol was measured in two saliva samples, one 45 min after awaking (T1) and the other 3 h later the same day (T2), from 6524 participants aged 45 years.

Results

No association was seen for abuse or household dysfunction in childhood and adult cortisol levels. In women but not men,T1cortisol was lowered by 7.9% per unit increase in childhood neglect score (range 0–3);T1toT2cortisol decline was less steep. High levels of maltreatment (abuse, neglect, witnessed abuse) were associated with >25% lowerT1cortisol in both men and women, and 24% higherT2cortisol for men after adjustment for concurrent depressive/anxiety symptoms.

Conclusions

In a non-clinical population, cumulative maltreatments in childhood were associated with flattened morning cortisol secretion in mid-adult life.
Effect of vitamin D supplement on depression scores in people
with low levels of serum 25-hydroxyvitamin D: nested case—control study and
randomised clinical trial
Authors: Kjærgaard Marie , Waterloo Knut , Wang Catharina E. A. , Almås Bjørg , Figenschau Yngve , Hutchinson Moira S. , Svartberg Johan , Jorde Rolf
Published: July 2012

Aims

To compare depressive symptoms in participants with low and high serum
25-hydroxyvitamin D (25(OH)D) levels and to examine whether
supplementation with vitamin D3 would improve symptoms in
those with low serum 25(OH)D levels.

Method

Participants with low 25(OH)D levels were randomised to either placebo or
40 000 IU vitamin D3 per week for 6 months. Individuals with
high serum 25(OH)D levels were used as nested controls. Depressive
symptoms were evaluated with the Beck Depression Inventory, Hospital
Anxiety and Depression Scale, Seasonal Pattern Assessment Scale and
Montgomery-Åsberg Depression Rating Scale. The study was registered at
ClinicalTrials.gov (NCT00960232).

Results

Participants with low 25(OH)D levels (n=230) at baseline
were more depressed (P<0.05) than participants with
high 25(OH)D levels (n=114). In the intervention study
no significant effect of high-dose vitamin D was found on depressive
symptom scores when compared with placebo.

Conclusions

Low levels of serum 25(OH)D are associated with depressive symptoms, but
no effect was found with vitamin D supplementation.
Reconciliation, Hope, Trust, and Instability in July Monarchy France
Authors: Bouton Cynthia A.
Published: July 2012

In 1832 and 1847, the Académie Française’s annual Montyon prix de vertu (prize for virtue) proffered a new model for virtue to shift attention away from fears of social rupture and dislocation and to restore trust in and hope for a cohesive society. The first-prize winners—a former slave from Saint-Domingue and a female servant from a small town in central France—had respectively intervened in the Haitian Revolution and the violence of 1847 to protect elite French from attacks on their persons and property. The awardees’ stories emphasized the persistent problems that nineteenth-century French elites confronted as they sought to reframe— both in imagination and in daily life—society in the revolutionary age and to manage their insecurities about the tensions revolutionary transformations had wrought. Yet an essential contradiction lay in a strategy foregrounding situations in which slaves and female servants acted heroically, assertively, and intelligently while their masters panicked as their world crumbled.

En 1832 et 1847, l’Académie française introduisit un nouveau modèle pour son prix annuel de vertu (le prix Montyon). Il s’agissait de faire diversion face aux peurs de rupture sociale, en détournant l’attention publique vers la confiance et l’espoir en une société cohésive. Les gagnants du premier prix—un ancien esclave de Saint-Domingue et une domestique d’une petite ville du centre de la France—étaient intervenus respectivement lors de la Révolution haïtienne et des violences de 1847 pour protéger les élites des attaques sur leurs personnes et leurs propriétés. Leurs histoires démontrent les problèmes persistants auxquels les élites françaises de la première moitié du dixneuvième siècle furent confrontés, au moment même où elles cherchaient à redéfinir les cadres de la société, à la fois dans l’imaginaire social et dans la vie quotidienne, et gérer leurs sentiments d’insécurité vis-à-vis des menaces révolutionnaires. Pourtant, une contradiction essentielle réside dans une stratégie qui met en avant des situations dans lesquelles les esclaves et les servantes agissèrent avec héroïsme, intelligence et assurance, tandis que leurs maîtres paniquaient, croyant que leur monde s’écroulait.
French Decadence, Arab Awakenings: Figures of Decay in the Arab Nahda
Authors: Fieni David
Published: July 2012

Examining the work of Ernest Renan in relation to thinkers confessing Arab and Islamic affiliations in the Ottoman fin de siècle allows us to understand how Orientalist scholarship has used decadence as the figure through which its positivist scientific claims were redistributed as performative speech acts. At the site where language, race, and religion–the positive symptoms of decadence–are knotted together, Renan describes a political theology of the color line. The supposed “truths” about Oriental decadence became distributed among the objects of its study (“Orientals”) within the terrain over which it sought textual (and ultimately, political) authority (“the Orient”). It was the dissemination of the truth of what Edward Said called the “Semitic object” outside of Europe that allowed Orientalism to facilitate the fragmentation and degeneration it only claimed, at one level, to describe. In contrast to Renan, the thinkers and writers of the Arab nahda, or “awakening,” examined here–Jamal al-Din al-Afghani, Abd al-Rahman al-Kawakibi, Farah Antun, and Ahmed Faris al-Shidyaq–devised their texts at ground level, shifting their tactics on a dynamic field of operations in response to the rapidly adapting strategies of imperial geopolitics and ideology. While many writers of the Arab nahda imagined an Arab historical subject awakening to a past defined in terms of the kind of authenticity defined by Orientalist scholarship, al-Shidyaq’s novel Al-Sāq ‘alā al-Sāq radicalizes both decadence and philology, demonstrating how the past might erupt in the present through language that forges ambivalent links to a lived relation with the past.
REST regulates the pool size of the different neural lineages by restricting the generation of neurons and oligodendrocytes from neural stem/progenitor cells
Authors: Covey Matthew V. , Streb Jeffrey W. , Spektor Roman , Ballas Nurit
Published: July 2012

REST is a master repressor of neuronal genes; however, whether it has any role during nervous system development remains largely unknown. Here, we analyzed systematically the role of REST in embryonic stem cells and multipotent neural stem/progenitor (NS/P) cells, including neurogenic and gliogenic NS/P cells derived from embryonic stem (ES) cells or developing mouse embryos. We showed that REST-null ES cells remained pluripotent and generated teratomas consisting of the three germ layers. By contrast, multipotent NS/P cells lacking REST displayed significantly reduced self-renewal capacity owing to reduced cell cycle kinetics and precocious neuronal differentiation. Importantly, although early-born neurogenic NS/P cells that lack REST were capable of differentiating to neurons and glia, the neuronal and oligodendrocytic pools were significantly enlarged and the astrocytic pool was shrunken. However, gliogenic NS/P cells lacking REST were able to generate a normal astrocytic pool size, suggesting that the shrinkage of the astrocytic pool generated from neurogenic NS/P cells lacking REST probably occurs by default. Microarray profiling of early-born NS/P cells lacking REST showed upregulation of neuronal as well as oligodendrocytic genes, specifically those involved in myelination. Furthermore, chromatin immunoprecipitation analyses showed that some of the upregulated oligodendrocytic genes contain an RE1 motif and are direct REST targets. Together, our data support a central role for REST during neural development in promoting NS/P cell self-renewal while restricting the generation and maturation of neurons and oligodendrocytes.
Mechanism of pectoral fin outgrowth in zebrafish development
Authors: Yano Tohru , Abe Gembu , Yokoyama Hitoshi , Kawakami Koichi , Tamura Koji
Published: July 2012

Fins and limbs, which are considered to be homologous paired vertebrate appendages, have obvious morphological differences that arise during development. One major difference in their development is that the AER (apical ectodermal ridge), which organizes fin/limb development, transitions into a different, elongated organizing structure in the fin bud, the AF (apical fold). Although the role of AER in limb development has been clarified in many studies, little is known about the role of AF in fin development. Here, we investigated AF-driven morphogenesis in the pectoral fin of zebrafish. After the AER-AF transition at ∼36 hours post-fertilization, the AF was identifiable distal to the circumferential blood vessel of the fin bud. Moreover, the AF was divisible into two regions: the proximal AF (pAF) and the distal AF (dAF). Removing the AF caused the AER and a new AF to re-form. Interestingly, repeatedly removing the AF led to excessive elongation of the fin mesenchyme, suggesting that prolonged exposure to AER signals results in elongation of mesenchyme region for endoskeleton. Removal of the dAF affected outgrowth of the pAF region, suggesting that dAF signals act on the pAF. We also found that the elongation of the AF was caused by morphological changes in ectodermal cells. Our results suggest that the timing of the AER-AF transition mediates the differences between fins and limbs, and that the acquisition of a mechanism to maintain the AER was a crucial evolutionary step in the development of tetrapod limbs.
Type II phosphatidylinositol 4-kinase regulates trafficking of secretory granule proteins inDrosophila
Authors: Burgess Jason , Del Bel Lauren M. , Ma Cheng-I J. , Barylko Barbara , Polevoy Gordon , Rollins Janet , Albanesi Joseph P. , Krämer Helmut , Brill Julie A.
Published: July 2012

Type II phosphatidylinositol 4-kinase (PI4KII) produces the lipid phosphatidylinositol 4-phosphate (PI4P), a key regulator of membrane trafficking. Here, we generated genetic models of the sole Drosophila melanogaster PI4KII gene. A specific requirement for PI4KII emerged in larval salivary glands. In PI4KII mutants, mucin-containing glue granules failed to reach normal size, with glue protein aberrantly accumulating in enlarged Rab7-positive late endosomes. Presence of PI4KII at the Golgi and on dynamic tubular endosomes indicated two distinct foci for its function. First, consistent with the established role of PI4P in the Golgi, PI4KII is required for sorting of glue granule cargo and the granule-associated SNARE Snap24. Second, PI4KII also has an unforeseen function in late endosomes, where it is required for normal retromer dynamics and for formation of tubular endosomes that are likely to be involved in retrieving Snap24 and Lysosomal enzyme receptor protein (Lerp) from late endosomes to the trans-Golgi network. Our genetic analysis of PI4KII in flies thus reveals a novel role for PI4KII in regulating the fidelity of granule protein trafficking in secretory tissues.
Conversion from mouse embryonic to extra-embryonic endoderm stem cells reveals distinct differentiation capacities of pluripotent stem cell states
Authors: Cho Lily T. Y. , Wamaitha Sissy E. , Tsai Isheng J. , Artus Jérôme , Sherwood Richard I. , Pedersen Roger A. , Hadjantonakis Anna-Katerina , Niakan Kathy K.
Published: July 2012

The inner cell mass of the mouse pre-implantation blastocyst comprises epiblast progenitor and primitive endoderm cells of which cognate embryonic (mESCs) or extra-embryonic (XEN) stem cell lines can be derived. Importantly, each stem cell type retains the defining properties and lineage restriction of their in vivo tissue of origin. Recently, we demonstrated that XEN-like cells arise within mESC cultures. This raises the possibility that mESCs can generate self-renewing XEN cells without the requirement for gene manipulation. We have developed a novel approach to convert mESCs to XEN cells (cXEN) using growth factors. We confirm that the downregulation of the pluripotency transcription factor Nanog and the expression of primitive endoderm-associated genes Gata6, Gata4, Sox17 and Pdgfra are necessary for cXEN cell derivation. This approach highlights an important function for Fgf4 in cXEN cell derivation. Paracrine FGF signalling compensates for the loss of endogenous Fgf4, which is necessary to exit mESC self-renewal, but not for XEN cell maintenance. Our cXEN protocol also reveals that distinct pluripotent stem cells respond uniquely to differentiation promoting signals. cXEN cells can be derived from mESCs cultured with Erk and Gsk3 inhibitors (2i), and LIF, similar to conventional mESCs. However, we find that epiblast stem cells (EpiSCs) derived from the post-implantation embryo are refractory to cXEN cell establishment, consistent with the hypothesis that EpiSCs represent a pluripotent state distinct from mESCs. In all, these findings suggest that the potential of mESCs includes the capacity to give rise to both extra-embryonic and embryonic lineages.
β-arrestin control of late endosomal sorting facilitates decoy receptor function and chemokine gradient formation
Authors: Mahabaleshwar Harsha , Tarbashevich Katsiaryna , Nowak Matthias , Brand Michael , Raz Erez
Published: July 2012

A crucial regulator of Cxcl12 is the decoy receptor Cxcr7, which controls the level of the chemokine in the tissue. The molecular mechanisms that enable Cxcr7 to function as an efficient molecular sink are not known. Using zebrafish primordial germ cells as a model, we identify a novel role for β-arrestins in controlling the intracellular trafficking of Cxcr7. β-arrestins facilitate the recycling of Cxcr7 from late endosomal compartments back to the plasma membrane, whereas the internalized ligand undergoes lysosomal degradation. β-arrestins thus function in regulating chemokine gradient formation, allowing responding cells to discriminate between alternative migration targets in vivo.
Drosophila Patj plays a supporting role in apical-basal polarity but is essential for viability
Authors: Zhou Wenke , Hong Yang
Published: July 2012

Patj has been characterized as one of the so-called polarity proteins that play essential and conserved roles in regulating cell polarity in many different cell types. Studies of Drosophila and mammalian cells suggest that Patj is required for the apical polarity protein complex Crumbs-Stardust (Pals1 or Mpp5 in mammalian cells) to establish apical-basal polarity. However, owing to the lack of suitable genetic mutants, the exact in vivo function of Patj in regulating apical-basal polarity and development remains to be elucidated. Here, we generated molecularly defined null mutants of Drosophila Patj (dPatj). Our data show conclusively that dPatj only plays supporting and non-essential roles in regulating apical-basal polarity, although such a supporting role may become crucial in cells such as photoreceptors that undergo complex cellular morphogenesis. In addition, our results confirm that dPatj possesses an as yet unidentified function that is essential for pupal development.
Muhammad Akbar Arzānī (–1772): Mughal physician and translator
Authors: Aggarwal Neil Krishan
Published: July 2012

Muhammad Akbar Arzānī was an influential Mughal physician famous throughout Iran and South Asia. His reputation is considered from contemporary accounts of his importance within the broader scholarship in South Asian culture and history. A brief synopsis of his life is provided, followed by a bibliography of his writings. Arzānī made Greco-Arabic knowledge accessible for Indo-Persian audiences in the 18th century.
Cellular automata approach to corrosion and passivity phenomena
Authors: Bartosik Łukasz , di Caprio Dung , Stafiej Janusz
Published: July 2012

Our research on employing the cellular automata methodology to corrosion and passivation phenomena is reviewed. Examples of a peculiar pit development are found and presented. The diffusion rate in the corroding medium is argued and shown in the simulation results to affect mainly the characteristic length scale for the corrosion process. New data for the pitting corrosion development on a planar interface are presented and discussed.
Can Automated Group Recommender Systems Help Consumers Make Better Choices?
Authors: Hennig-Thurau Thorsten , Marchand André , Marx Paul
Published: July 2012

Because hedonic products consist predominantly of experience attributes, often with many available alternatives, choosing the “right” one is a demanding task for consumers. Decision making becomes even more difficult when a group, instead of an individual consumer, will consume the product, as is regularly the case for hedonic offerings such as movies, opera performances, and wine. Noting the prevalence of automated recommender systems as decision aids, the authors investigate the power of group recommender systems that consider the preferences of all group members. The authors develop a conceptual framework of the effects of group recommenders and empirically examine these effects through two choice experiments. They find that automated group recommenders offer more valuable information than single recommenders when the choice agent must consume the recommended alternative. However, when agents choose freely among alternatives, the group's social relationship quality determines whether group recommenders actually create higher group value. Finally, group recommenders outperform decision making without automated recommendations if the agent's intention to use the systems is high. A decision tree model of recommender usage offers guidance to hedonic product managers.
On the coordination chemistry of the dimercury(I) ion with O-donor ligands
Authors: Lundberg Daniel , Persson Ingmar
Published: July 2012

An overview of published crystalline dimercury(I) hydrates, solvates, and complexes/compounds with O-donor ligands shows that there is virtually no correlation between the Hg—Hg bond distance and the overall Hg—O bonding conditions. Additionally, many structures feature different configurations for the individual mercury atoms in the dimercury(I) ion, Hg2
2+. To supplement these findings, the crystal structures of the perchlorate salts of hydrated and dimethylsulfoxide (dmso) solvated mercury(I), [Hg2(OH2)2](ClO4)2
(1) and [Hg10(OS(CH3)2)16](ClO4)10
(2), respectively, have been determined by single crystal X-ray diffraction. In compound 1, the perchlorate ions act as bridges between the almost linear [Hg2(OH2)2]2+ units forming infinite chains. The Hg—Hg bond distance is 2.500(1) Å and the Hg—O distance to the water molecule is 2.231(19) Å. Additional much weaker Hg—O bonds to the bridging perchlorate oxygens lie in the range 2.78–3.15 Å. Compound 2 consists of five crystallographically independent [Hg—Hg]2+ units solvated and bridged by dmso oxygens. These larger entities form chains through much weaker bridging perchlorate ions at longer distances, 3.0–3.3 Å, with a few remaining perchlorate ions isolated in the lattice. The mean Hg—Hg bond distance is 2.500(1) Å, while the Hg—Odmso bond distances are in the range of 2.15–2.92 Å. The dmso molecules are grouped into three types of coordination, strong κO-terminal, medium μ2
O-bridging, or medium/weak μ3
O-bridging, depending on which dimercury(I) ion(s) in the entity they coordinate to.
Synthesis of water dispersed Fe3O4@ZnO Composite Nanoparticles by the Polyol Method
Authors: Collantes Yesusa , Perales-Perez Oscar , Uwakweh Oswald N. C. , Maxime J.-F.Guinel
Published: July 2012

Water-soluble Fe3O4@ZnO composite nanoparticles (NPs) were synthesized using a polyol route. The effects of the addition of the ZnO phase were evaluated by varying the Zn/Fe molar ratio in the 0.25-1.00 range as a function of the reaction time. X-ray diffractometry confirmed the formation of the magnetite and ZnO phases and suggested the possible formation of a composite structure. Also, using this method, pure magnetite and ZnO NPs were synthesized. The average crystallite sizes were estimated to 6.3 ± 0.3 nm and 8.6 ± 0.6 nm for magnetite and ZnO NPs, respectively. The samples were examined using transmission electron microscopy. Fourier transform infrared spectra indicated the presence of adsorbed species onto the solids surface, which may explain the good stability of the materials in water. Photoluminescence measurements at room temperature for pure ZnO nanoparticles exhibited the characteristic excitonic emission around 395 nm. Vibrating Sample Magnetometer measurements at room temperature evidenced the superparamagnetic behavior of magnetite nanocrystals, with a saturation magnetization of 60emu/g. The maximum magnetization ranged from 28 to 54emu/g for the composite NPs. Mössbauer spectroscopy measurements at room temperature showed evidence of evolving Fe-sites associated to superparamagnetic particles, as reflected on the coexistence of prominent doublet peaks and very weak sextet peaks.
Reinserção familiar de adolescentes: processos malsucedidos
Authors: Siqueira Aline Cardoso , Massignan Lucianna Tortorelli , Dell'Aglio Débora Dalbosco
Published: July 2012

Este artigo investiga o processo de fracasso na reinserção familiar e a subsequente reinstitucionalização de duas adolescentes. Foram realizados estudos de caso, a partir de entrevistas com as adolescentes e entrevistas informais com técnicos da instituição e monitores. Os resultados indicaram semelhanças nos processos de reinserção, como carência de uma avaliação prévia da situação, considerando a motivação e preparação da família e das jovens para o processo, assim como a falta de um acompanhamento sistemático no período de reinserção. Políticas públicas de atenção a este processo são sugeridas para evitar novas rupturas de vínculos, e para que o direito à convivência familiar e comunitária de jovens institucionalizados possa ser efetivado.
Comparison of Transect-Based Standard and Adaptive Sampling Methods for Invasive Plant Species
Authors: Maxwell Bruce D. , Backus Vickie , Hohmann Matthew G. , Irvine Kathryn M. , Lawrence Patrick , Lehnhoff Erik A. , Rew Lisa J
Published: July 2012

Early detection of an invading nonindigenous plant species (NIS) may be critical for efficient and effective management. Adaptive survey sampling methods may provide unbiased sampling for best estimates of distribution of rare and spatially clustered populations of plants in the early stages of invasion. However, there are few examples of these methods being used for nonnative plant surveys in which travelling distances away from an initial or source patch, or away from a road or trail, can be time consuming due to the topography and vegetation. Nor is there guidance as to which of the many adaptive methods would be most appropriate as a basis for invasive plant mapping and subsequent management. Here we used an empirical complete census of four invader species in early to middle stages of invasion in a management area to assess the effectiveness and efficiency of three nonadaptive methods, four adaptive cluster methods, and four adaptive web sampling methods that all originated from transects. The adaptive methods generally sampled more NIS-occupied cells and patches than standard transect approaches. Sampling along roads only was time-efficient and effective, but only for species with restricted distribution along the roads. When populations were more patchy and dispersed over the landscape the adaptive cluster starting at the road generally proved to be the most time-efficient and effective NIS detection method.
Pathways of Invasive Plant Spread to Alaska: III. Contaminants in Crop and Grass Seed
Authors: Conn Jeffery S.
Published: July 2012

Invasive plants disperse to new areas via numerous pathways. Study of these pathways helps to focus limited budgets toward prevention and early detection. This study examined potentially invasive seed contaminants in imported crops and grass seed as pathways for plant dispersal to Alaska. Crop and grass seed were purchased from 13 Alaska retail outlets representing 14 seed suppliers. Seed bags were sampled using federally mandated protocols and were analyzed for crop seeds that were not supposed to be included and for weed contaminants. Ninety-five weed and 36 contaminant crop taxa were found. Crop seed contained 43 weed taxa and 15 other crop species contaminants, a mean of 6.4 taxa and 3,844 contaminant seed kg−1. Grass seed samples contained 73 weed taxa and 21 crop contaminants, a mean of 3.5 contaminant species and 1,250 seeds kg−1. Two species prohibited by the Alaska seed law were found: Canada thistle was found in a single crop sample, and quackgrass was found in two grass samples. There were no significant relationships between either seed type or supplier and either the number of contaminant species or number of seeds. Labels of 33% of crop samples and 8% of grass samples claimed 0.00% weed seeds, but low (0.007% by weight, 2 species) to high (1.18% by weight, 13 species) amounts of weed contaminants were found. Importation of crop seed is a large pathway for seed movement, causing significant propagule pressure and an increased likelihood of establishment by new invasive plant populations. Prevention of spread via this pathway would be enhanced by changes to seed laws, by greater regulatory enforcement, and by including on the label, the names of all weed and contaminant crop species found in the law-required samples. Consumers could then make decisions on whether to purchase seed based on the potentially invasive species that would be planted with the desired seed.
Dynamic versus static occupancy: How stable are habitat associations through a breeding season?
Authors: McClure Christopher J. W. , Hill Geoffrey E.
Published: July 2012

Most studies of habitat use by animals assume that there is little movement by individuals once they have settled. This assumption of static occupancy is especially true in studies of birds, even though many bird species are known to abandon failed nest sites in search of better habitat or to move up a habitat gradient as the season proceeds. If birds move into different habitats as the season progresses, studies assuming static use of habitat may provide misleading or incomplete inference into habitat use. We tested the hypothesis that birds use different habitats as the breeding season progresses by analyzing point counts conducted early and late in the breeding season within Tuskegee National Forest, AL. For 15 species of conservation concern, we compared models that assumed static occupancy with models that estimated apparent movement between early and late‐season surveys. Models that estimated movement outcompeted static models for every species. Furthermore, patterns of movement provided inference that would not have been gained through a static modeling approach, with species moving into habitats traditionally known to be of high quality, and moving out of those assumed to be of poor quality. Our results suggest that studies of habitat use would benefit from estimating movement within a season.
Expression of VASA mRNA in Testis as a Significant Predictor of Sperm Recovery by Microdissection Testicular Sperm Extraction in Patient With Nonobstructive Azoospermia
Authors: Ando Makoto , Yamaguchi Kohei , Chiba Koji , Miyake Hideaki , Fujisawa Masato
Published: July 2012

Abstract: It would be of value to evaluate whether expression levels of mRNAs playing important roles in spermatogenesis could be used as predictors of successful testicular sperm recovery by microdissection testicular sperm extraction (TESE) in patients with nonobstructive azoospermia (NOA). This study included 52 patients with NOA who underwent therapeutic sperm retrieval by micro‐TESE at our institution. We measured expression levels of VASA, outer dense fiber‐1 (ODF1), ODF2, and sperm mitochondria—associated cysteine‐rich protein (SMCP) mRNAs in testicular tissue specimens obtained from these patients by quantitative real‐time reverse transcription polymerase chain reaction. Expression patterns of these mRNAs were analyzed focusing on the outcomes of sperm retrieval by micro‐TESE. There were no significant differences in age, testicular volume, and serum levels of follicle‐stimulating hormone, luteinizing hormone, and testosterone between successful and unsuccessful TESE groups; however, the proportion of patients with Sertoli cell only in the successful TESE group was significantly lower than that in the unsuccessful TESE group. Additionally, expression levels of VASA, ODF1, ODF2, and SMCP mRNAs in the successful TESE group were significantly greater than those in the unsuccessful TESE group. Univariate analysis identified histological classification, VASA, ODF1, ODF2, and SMCP expressions as significant predictors of sperm retrieval, of which only VASA mRNA expression appeared to be independently related to micro‐TESE outcome on multivariate analysis. These findings suggest that measurement of VASA mRNA in testis could be a useful adjunct to conventional parameters for predicting sperm retrieval by micro‐TESE in patients with NOA.
A Rare Cause of Hypertestosteronemia in a 68‐Year‐Old Patient: A Leydig Cell Tumor Due to a Somatic GNAS (Guanine Nucleotide‐Binding Protein, Alpha‐Stimulating Activity Polypeptide 1)–Activating Mutation
Authors: Libé Rossella , Fratticci Amato , Lahlou Najiba , Jornayvaz François R. , Tissier Frédérique , Louiset Estelle , Guibourdenche Jean , Vieillefond Annick , Zerbib Marc , Bertherat Jérôme
Published: July 2012

Abstract: Leydig cell tumors of the testis are the most common type of non—germ cell testicular tumors. In adult patients, gynecomastia, oligozoospermia, erectile dysfunction, and other signs of feminization can be present, whereas testosterone levels are frequently in the normal range or slightly reduced. We describe a patient with a history of impaired sexual function, as well as progressive enlargement of the left testis, without gynecomastia. Hormonal evaluation demonstrated very high testosterone, estrogen, and pan—alpha‐inhibin levels. Magnetic resonance imaging revealed the presence of left testicular hypertrophy without evidence of testicular mass. After left orchiectomy, histologic examination confirmed the diagnosis of Leydig cell tumor, and steroid hormone levels normalized. A heterozygous missense somatic gsp mutation (R201C) was found in tumoral tissue, whereas no mutation was found in the surrounding normal tissue or in leukocyte DNA. This case provides evidence that somatic activating gsp mutation in Leydig cells may result in tumor development, leading to overexpression of the inhibin alpha subunit and hyperactivity of the testosterone biosynthetic pathway.
Low Androgen Sensitivity Is Associated With Low Levels of Akt Phosphorylation in LNCaP‐E9 Cells
Authors: Iguchi Kazuhiro , Fukami Kazuhiro , Ishii Kenichiro , Otsuka Takashi , Usui Shigeyuki , Sugimura Yoshiki , Hirano Kazuyuki
Published: July 2012

Abstract: We previously characterized LNCaP‐E9, a low—androgen‐sensitive LNCaP cell subline. LNCaP‐E9 cells exhibit lower expression of androgen‐regulated genes, including prostate‐specific antigen (PSA), FK506 binding protein 5 (FKBP5), and prostatic acid phosphatase (PAcP), compared with LNCaP cells after treatment with the synthetic androgen R1881, confirming that the cells have low sensitivity to androgens. To understand the mechanism underlying low androgen sensitivity of LNCaP‐E9 cells, we examined the activities of the Akt, p44/42, and p38 mitogen‐activated protein kinase signaling pathways, all of which are known to be linked to androgen receptor signaling. We found that the phosphorylation of Akt at Ser473 was markedly lower in LNCaP‐E9 cells than in LNCaP cells. Inhibition of Akt phosphorylation by the phosphatidylinositol 3‐kinase inhibitor LY294002 resulted in reduction of PSA expression in LNCaP cells. Conversely, activation of Akt by serum starvation led to the induction of PSA expression in LNCaP‐E9 cells. These results suggest that the impaired Akt phosphorylation in LNCaP‐E9 cells is associated with low androgen sensitivity.