bluuebunny/crossref_metadata_2025 huggingface dataset:
Distinct Mechanisms Regulate Exposure of Neutralizing Epitopes in the V2 and V3 Loops of HIV-1 Envelope
Authors: Upadhyay Chitra , Mayr Luzia M. , Zhang Jing , Kumar Rajnish , Gorny Miroslaw K. , Nádas Arthur , Zolla-Pazner Susan , Hioe Catarina E.
Published: August 2014

Broadly neutralizing antibodies targeting the HIV-1 envelope (Env) are key components for protection against HIV-1. However, many cross-reactive epitopes are often occluded. This study investigates the mechanisms contributing to the masking of V2i (variable loop V2 integrin) epitopes compared to the accessibility of V3 epitopes. V2i are conformation-dependent epitopes encompassing the integrin α4β7-binding motif on the V1V2 loop of HIV-1 Env gp120. The V2i monoclonal antibodies (MAbs) display extensive cross-reactivity with gp120 monomers from many subtypes but neutralize only few viruses, indicating V2i's cryptic nature. First, we asked whether CD4-induced Env conformational changes affect V2i epitopes similarly to V3. CD4 treatment of BaL and JRFL pseudoviruses increased their neutralization sensitivity to V3 MAbs but not to the V2i MAbs. Second, the contribution of N-glycans in masking V2i versus V3 epitopes was evaluated by testing the neutralization of pseudoviruses produced in the presence of a glycosidase inhibitor, kifunensine. Viruses grown in kifunensine were more sensitive to neutralization by V3 but not V2i MAbs. Finally, we evaluated the time-dependent dynamics of the V2i and V3 epitopes. Extending the time of virus-MAb interaction to 18 h before adding target cells increased virus neutralization by some V2i MAbs and all V3 MAbs tested. Consistent with this, V2i MAb binding to Env on the surface of transfected cells also increased in a time-dependent manner. Hence, V2i and V3 epitopes are highly dynamic, but distinct factors modulate the antibody accessibility of these epitopes. The study reveals the importance of the structural dynamics of V2i and V3 epitopes in determining HIV-1 neutralization by antibodies targeting these sites.

IMPORTANCE
Conserved neutralizing epitopes are present in the V1V2 and V3 regions of HIV-1 Env, but these epitopes are often occluded from Abs. This study reveals that distinct mechanisms contribute to the masking of V3 epitopes and V2i epitopes in the V1V2 domain. Importantly, V3 MAbs and some V2i MAbs display greater neutralization against relatively resistant HIV-1 isolates when the MAbs interact with the virus for a prolonged period of time. Given their highly immunogenic nature, V3 and V2i epitopes are valuable targets that would augment the efficacy of HIV vaccines.
Epstein-Barr Virus Late Gene Transcription Depends on the Assembly of a Virus-Specific Preinitiation Complex
Authors: Aubry Valentin , Mure Fabrice , Mariamé Bernard , Deschamps Thibaut , Wyrwicz Lucjan S. , Manet Evelyne , Gruffat Henri
Published: August 2014

During their productive cycle, herpesviruses exhibit a strictly regulated temporal cascade of gene expression that has three general stages: immediate early (IE), early (E), and late (L). Promoter complexity differs strikingly between IE/E genes and L genes. IE and E promoters contain
cis
-regulating sequences upstream of a TATA box, whereas L promoters comprise a unique
cis
element. In the case of the gammaherpesviruses, this element is usually a TATT motif found in the position where the consensus TATA box of eukaryotic promoters is typically found. Epstein-Barr virus (EBV) encodes a protein, called BcRF1, which has structural homology with the TATA-binding protein and interacts specifically with the TATT box. However, although necessary for the expression of the L genes, BcRF1 is not sufficient, suggesting that other viral proteins are also required. Here, we present the identification and characterization of a viral protein complex necessary and sufficient for the expression of the late viral genes. This viral complex is composed of five different proteins in addition to BcRF1 and interacts with cellular RNA polymerase II. During the viral productive cycle, this complex, which we call the vPIC (for viral preinitiation complex), works in concert with the viral DNA replication machinery to activate expression of the late viral genes. The EBV vPIC components have homologs in beta- and gammaherpesviruses but not in alphaherpesviruses. Our results not only reveal that beta- and gammaherpesviruses encode their own transcription preinitiation complex responsible for the expression of the late viral genes but also indicate the close evolutionary history of these viruses.

IMPORTANCE
Control of late gene transcription in DNA viruses is a major unsolved question in virology. In eukaryotes, the first step in transcriptional activation is the formation of a permissive chromatin, which allows assembly of the preinitiation complex (PIC) at the core promoter. Fixation of the TATA box-binding protein (TBP) is a key rate-limiting step in this process. This study provides evidence that EBV encodes a complex composed of six proteins necessary for the expression of the late viral genes. This complex is formed around a viral TBP-like protein and interacts with cellular RNA polymerase II, suggesting that it is directly involved in the assembly of a virus-specific PIC (vPIC).
Probing the Sites of Interactions of Rotaviral Proteins Involved in Replication
Authors: Viskovska Maria , Anish Ramakrishnan , Hu Liya , Chow Dar-Chone , Hurwitz Amy M. , Brown Nicholas G. , Palzkill Timothy , Estes Mary K. , Prasad B. V. Venkataram
Published: August 2014

Replication and packaging of the rotavirus genome occur in cytoplasmic compartments called viroplasms, which form during virus infection. These processes are orchestrated by yet-to-be-understood complex networks of interactions involving nonstructural proteins (NSPs) 2, 5, and 6 and structural proteins (VPs) 1, 2, 3, and 6. The multifunctional enzyme NSP2, an octamer with RNA binding activity, is critical for viroplasm formation with its binding partner, NSP5, and for genome replication/packaging through its interactions with replicating RNA, the viral polymerase VP1, and the inner core protein VP2. Using isothermal calorimetry, biolayer interferometry, and peptide array screening, we examined the interactions between NSP2, VP1, VP2, NSP5, and NSP6. These studies provide the first evidence that NSP2 can directly bind to VP1, VP2, and NSP6, in addition to the previously known binding to NSP5. The interacting sites identified from reciprocal peptide arrays were found to be in close proximity to the RNA template entry and double-stranded RNA (dsRNA) exit tunnels of VP1 and near the catalytic cleft and RNA-binding grooves of NSP2; these sites are consistent with the proposed role of NSP2 in facilitating dsRNA synthesis by VP1. Peptide screening of VP2 identified NSP2-binding sites in the regions close to the intersubunit junctions, suggesting that NSP2 binding could be a regulatory mechanism for preventing the premature self-assembly of VP2. The binding sites on NSP2 for NSP6 were found to overlap that of VP1, and the NSP5-binding sites overlap those of VP2 and VP1, suggesting that interaction of these proteins with NSP2 is likely spatially and/or temporally regulated.

IMPORTANCE
Replication and packaging of the rotavirus genome occur in cytoplasmic compartments called viroplasms that form during virus infection and are orchestrated by complex networks of interactions involving nonstructural proteins (NSPs) and structural proteins (VPs). A multifunctional RNA-binding NSP2 octamer with nucleotidyl phosphatase activity is central to viroplasm formation and RNA replication. Here we provide the first evidence that NSP2 can directly bind to VP1, VP2, and NSP6, in addition to the previously known binding to NSP5. The interacting sites identified from peptide arrays are consistent with the proposed role of NSP2 in facilitating dsRNA synthesis by VP1 and also point to NSP2's possible role in preventing the premature self-assembly of VP2 cores. Our findings lead us to propose that the NSP2 octamer with multiple enzymatic activities is a principal regulator of viroplasm formation, recruitment of viral proteins into the viroplasms, and possibly genome replication.
The long-term financial impact of electronic health record implementation
Authors: Howley Michael J , Chou Edgar Y , Hansen Nancy , Dalrymple Prudence W
Published: August 2014

Objective To examine the financial impact of electronic health record (EHR) implementation on ambulatory practices.

Methods We tracked the practice productivity (ie, number of patient visits) and reimbursement of 30 ambulatory practices for 2 years after EHR implementation and compared each practice to their pre-EHR implementation baseline.

Results Reimbursements significantly increased after EHR implementation even though practice productivity (ie, the number of patient visits) decreased over the 2-year observation period. We saw no evidence of upcoding or increased reimbursement rates to explain the increased revenues. Instead, they were associated with an increase in ancillary office procedures (eg, drawing blood, immunizations, wound care, ultrasounds).

Discussion The bottom line result—that EHR implementation is associated with increased revenues—is reassuring and offers a basis for further EHR investment. While the productivity losses are consistent with field reports, they also reflect a type of efficiency—the practices are receiving more reimbursement for fewer seeing patients. For the practices still seeing fewer patients after 2 years, the solution likely involves advancing their EHR functionality to include analytics. Although they may still see fewer patients, with EHR analytics, they can focus on seeing the right patients.

Conclusions Practice reimbursements increased after EHR implementation, but there was a long-term decrease in the number of patient visits seen in this ambulatory practice context.
More than meets the eye: the ‘pink salmon patch’
Authors: Pallavi Ranjita , Popescu-Martinez Andrea
Published: August 2014

Ocular adnexal lymphomas account for 1–2% of all non-Hodgkin's lymphomas. Conjunctiva is the primary site of involvement in one-third of cases. We present a case of a 47-year-old Hispanic woman who presented with left eye itching and irritation associated with a painless pink mass. Physical examination revealed the presence of a ‘pink salmon-patch’ involving her left medial conjunctiva. Orbital CT showed a subcentimeter left preseptal soft tissue density. Biopsy revealed a dense subepithelial lymphoid infiltrate comprised predominantly of B cells that did not coexpress CD5 or CD43. These findings were consistent with B-cell marginal zone lymphoma. Further staging assessment did not reveal disseminated disease. She had stage 1E extranodal marginal zone lymphoma as per Ann Arbor staging system. She received external beam radiotherapy to her left eye with complete resolution of the lymphoma in 2 months and continues to remain tumour free at 8-month follow-up. She will be followed up closely for development of any local (unilateral or contralateral eye) or systemic recurrence in the long run.
Bilateral supplemental permanent maxillary lateral incisors in a non-syndromic patient
Authors: Bhullar Mandeep Kaur , Uppal Amandeep Singh , Kochhar Gulsheen Kaur , Singh Ranjit
Published: August 2014

A supernumerary tooth is an additional entity to the normal series and can be seen in all quadrants of the jaw. Occurrence may be single or multiple, unilateral or bilateral, erupted or impacted in one or in both jaws. Multiple supernumeraries are rare in individuals with no other associated disease or syndromes. The conditions commonly associated with an increased prevalence of supernumerary teeth include cleft lip and palate, cleidocranial dysplasia and Gardner syndrome. The supplemental supernumerary refers to a duplication of teeth in normal series and is found at the end of a tooth series. A supplemental tooth may closely resemble the teeth of the group to which it belongs or it may bear little resemblance in size or shape to the teeth with which it is associated. This report presents a case with bilateral supplemental upper permanent lateral incisors without any symptoms of associated disorders.
Unilateral choroidal granulomas complicated by choroidal neovascular membrane treated successfully with intravitreal triamcinolone in a patient with sarcoidosis
Authors: Khatib Tasneem , Hughes Patrick W , Burton Benjamin J L
Published: August 2014

This case describes the use of intravitreal triamcinolone in the treatment of unilateral choroidal granulomas secondary to systemic sarcoidosis complicated by choroidal neovascular membrane. A single injection of 2 mg intravitreal triamcinolone was administered as treatment for rapidly progressing choroidal granulomas and associated choroidal neovascular membrane with subretinal fluid. Visual acuity had dropped from 6/5 to 6/48 with the progressing lesions. The patient was a 52-year-old woman with type 2 diabetes mellitus who was reluctant to consider oral steroids in view of their side effect profile. Ten days after injection, visual acuity improved to 6/24 and to 6/6 at 3 months follow-up with resolution of the subretinal fluid. There was no rise in intraocular pressure. There has been no recurrence at 5 months follow-up.
Pancreatic enzyme replacement therapy (PERT) for malabsorption in patients with metastatic pancreatic cancer
Authors: Landers Amanda , Muircroft Wendy , Brown Helen
Published: August 2014

Purpose

The diagnosis of metastatic pancreatic cancer (PC) carries a poor prognosis. PC is associated with weight loss and malabsorption in high rates secondary to pancreatic exocrine insufficiency. UK and USA guidelines exist recommending the empiric use of pancreatic enzyme replacement therapy (PERT) for quality of life in these patients. The aim of this study is to review the use of PERT in patients with metastatic PC referred to a specialist palliative care service.

Methods

Retrospective observational study of patients referred to the service between January 2010 and July 2012 with a diagnosis of PC. Information about PERT use, tumour site and frequency of symptoms was collected.

Results

129 patients were referred, with a higher number in the eighth decade. Only 21% of this study group were prescribed PERT. Over 70% of patients had symptoms that could be attributable to malabsorption, mainly abdominal pain. Other symptoms such as bloating, wind and steatorrhoea were also common.

Conclusions

Guidelines recommending empiric treatment of PERT in patients with metastatic PC are not currently being utilised.
Dependence receptors and colorectal cancer
Authors: Mehlen Patrick , Tauszig-Delamasure Servane
Published: August 2014

The research on colorectal cancer (CRC) biology has been leading the oncology field since the early 1990s. The search for genetic alterations has allowed the identification of the main tumour suppressors or oncogenes. Recent work obtained in CRC has unexpectedly proposed the existence of novel category of tumour suppressors, the so-called ‘dependence receptors’. These transmembrane receptors behave as Dr Jekyll and Mr Hyde with two opposite sides: they induce a positive signalling (survival, proliferation, differentiation) in presence of their ligand, but are not inactive in the absence of their ligand and rather trigger apoptosis when unbound. This trait confers them a conditional tumour suppressor activity: they eliminate cells that grow abnormally in an environment offering a limited quantity of ligand. This review will describe how receptors such as deleted in colorectal carcinoma (DCC), uncoordinated 5 (UNC5), rearranged during transfection (RET) or TrkC constrain CRC progression and how this dependence receptor paradigm may open up therapeutical perspectives.
Preliminary experience with the Pipeline Flex Embolization Device: technical note
Authors: Martínez-Galdámez M , Gil A , Caniego J L , Gonzalez E , Bárcena E , Perez S , Garcia-Bermejo P , Ortega-Gutierrez S
Published: August 2014

Background

Clinical experience with the Pipeline Embolization Device (PED) has been widely described in the literature since it obtained its European CE and FDA approvals in 2008 and 2011, respectively. The new generation of PED, the Pipeline Flex Embolization Device, received the CE mark of approval in March 2014. While the implant composition has not changed, its new delivery system has some differences. One of the main changes from the previous generation is a new delivery system that makes the device resheathable until deployed over 90% of its length. We present our preliminary experience using this device.

Methods

Between May and June 2014, six patients with six aneurysms were treated with the Pipeline Flex device.

Results

All devices were placed properly, without technical difficulties. We successfully resheathed and repositioned the device in two cases. Minor and major intraprocedural or periprocedural events were noted.

Conclusions

The Pipeline Flex device allows more precise and controlled deployment than the current PED device. Although this preliminary experience seems positive, multicenter larger series will be needed to confirm the safety and durability of this new device.
Sudden Unexpected Death in North Carolina (SUDDEN): methodology review and screening results
Authors: Nanavati Parin P , Mounsey John Paul , Pursell Irion W , Simpson Ross J , Lewis Mary Elizabeth , Mehta Neil D , Williams Jefferson G , Bachman Michael W , Myers J Brent , Chung Eugene H
Published: August 2014

Objectives

This paper describes the methodology for a prospective, community-based study of sudden unexpected death in Wake County, North Carolina.

Methods

From 1 March to 29 June 2013, data of presumed cardiac arrest cases were captured from Wake County Emergency Medical Services. Participants were screened into the presumed sudden unexpected death group based on specific and sequential screening criteria, and medical and public records were collected for each participant in this group. A committee of independent cardiologists reviewed all data to determine final inclusion/exclusion of each participant into registry.

Results

We received 398 presumed cardiac arrest referrals. Of these, 105 participants, age 18–65 years old, were identified as presumed sudden unexpected deaths. The primary reason for exclusion was survival to hospital (38%). Ninety-five per cent of participants in the presumed sudden unexpected death group experienced an unwitnessed death. Hypertension was present in almost 50%, while dyslipidaemia and diabetes mellitus were present in almost 25% of the same group. In addition, the presumed sudden unexpected death group includes 67.6% males (95% CI 58 to 76) whereas the control group only included 58.9% (95% CI 46 to 55) males.

Conclusions

Participant identification and data collection processes identify presumed sudden unexpected death cases and secure medical and public data for screening and final adjudication. The study infrastructure developed in Wake County will allow its expansion to other counties in North Carolina. Preliminary data indicate the study presently focuses on a population demographically representative of North Carolina.
Interaction between decomposing litter and soil fauna of theBetula ermaniiforest floor of the Changbai Mountains, China
Authors: Li Xiaoqiang , Yin Xiuqin , Wang Zhenhai , Fan Weihong
Published: August 2014

Soil fauna play a key role in litter decomposition as they influence the litter mass loss rate in terrestrial ecosystems. However, the interaction between decomposing litter and soil fauna has not been adequately addressed. We examine the interaction between different types of decomposing litter and soil fauna on the Betula ermanii Cham. (BE) forest floor of the Changbai Mountains, China, by measuring the mass loss of six litter species groups using litterbags with two sizes of mesh (4 mm and 0.01 mm) during a yearlong experiment. Soil fauna were identified at the order level. We found that soil fauna have a limited effect on litter mass loss at the initial stage of the experiment. Its positive effect became apparent at month 12 of the experiment. After 1 year, soil fauna increased the litter mass loss rate of the high-quality litter of Parasenecio komarovianus (Pojark.) Y.L. Chen (PK) by 7.02% and of the low-quality litter of Rhododendron aureum Georgi (RA) by 25.26%. BE + PK litter was associated with a significantly higher abundance of soil fauna at months 8 and 10 of the experiment and also with a significantly higher richness of soil fauna at month 10 of the experiment. At the end of the experiment, however, the Shannon–Wiener diversity index of soil fauna was not necessarily higher in mixed-species litter. Litter mixing did promote the abundance, richness, and diversity of soil fauna during the warm season in the high-quality litter substrate of BE + PK. Our results illustrate that the impact of soil fauna on the litter mass loss of both single- and mixed-species litterbags ranges from a limited impact to a positive impact as litter mass loss advances. The soil fauna contribute more to the litter mass loss of the low-quality litter with higher C to N ratios than to those with a low C to N ratio. The promoting effect of litter mixing on the soil faunal community composition is only short term and is dependent on substrate quality.
Recent Advances in Support Vector Clustering: Theory and Applications
Authors: Li Huina , Ping Yuan
Published: August 2014

As an important boundary-based clustering algorithm, support vector clustering (SVC) can benefit many real applications owing to its capability of handling arbitrary cluster shapes, especially those directly or indirectly related to pattern exploration and description. As the application deepens, the importance of performance (i.e. criterions of accuracy and efficiency) of SVC increases. To identify gaps in the current methods and propose novel research directions for SVC, we present a survey of the literature in this area. Our approach is to classify the most recent advances into either theory or application. For theoretical contributions, advances related to parameter selection and optimization, dual-problem solutions, and cluster labeling are introduced. We also simultaneously summarize the advantages and drawbacks of each study. With respect to applications, we clearly describe eight groups of schemes based on SVC, either as individual or hybrid methods. Finally, we identify the gaps in SVC research and suggest several future research issues and trends.
A Location-Based Duplex Scheme for Cost Effective Rural Broadband Connectivity Using IEEE 802.22 Cognitive Radio Based Wireless Regional Area Networks
Authors: Kalidoss R. , Bhagyaveni M. A. , Vishvaksenan K. S.
Published: August 2014

The search for a method of utilizing the scarce spectrum in an efficient manner is an active area of research in both academic and industrial communities. IEEE 802.22 is a standard for wireless regional area network (WRAN) based on cognitive radio (CR) that operates over underutilized portions of TV bands (54–862 MHz). Time division duplex (TDD)-based WRAN cells have such advantages as dynamic traffic allocation, traffic asymmetry to users and ease of spectrum allocation. However, these cells suffer from severe cross time slot (CTS) interference when the frames of the cells are not synchronized with adjacent WRAN cells. In this paper, we evaluate the location-based duplex (LBD) scheme for eliminating the CTS interference. The proposed LBD system is much more flexible and efficient in providing asymmetric data service and eliminating CTS interference by exploiting the advantages of both TDD and frequency division duplex (FDD) schemes. We also compare the performance of LBD systems with virtual cell concepts. Furthermore, our simulation results reveal that LBD-based systems outperform the virtual cell approach in terms of the low signal-to-interference (SIR) ratio requirement by mitigating the effects of CTS.
g-Riesz dual sequences for g-Bessel sequences
Authors: Osgooei E. , Najati A. , Faroughi M. H.
Published: August 2014

Duality principles in Gabor theory play a fundamental role for analyzing Gabor systems. In this paper, we obtain some results of duality principles for g-frames. Let {γj ∈ B(H, Hj) : j ∈ ℕ} and {ηi ∈ B(H, Hi) : i ∈ ℕ} be g-orthonormal bases for H with respect to {Hi}i∈ℕ. For a g-Bessel sequence Λ = {Λi ∈ B(H, Hi) : i ∈ ℕ}, we define [Formula: see text]. Then we describe some properties of the sequence [Formula: see text]. We also characterize the sequence [Formula: see text] when Ψ = {Ψi ∈ B(H, Hi) : i ∈ ℕ} is a dual g-frame of {Λi}i∈ℕ.
Tectono-stratigraphic evolution of the Andean Orogen between 31 and 37°S (Chile and Western Argentina)
Authors: Charrier Reynaldo , Ramos Victor A. , Tapia Felipe , Sagripanti Lucía
Published: August 2014

In this classic segment, many tectonic processes, like flat-subduction, terrane accretion and steepening of the subduction, among others, provide a robust framework for their understanding. Five orogenic cycles, with variations in location and type of magmatism, tectonic regimes and development of different accretionary prisms, show a complex evolution. Accretion of a continental terrane in the Pampean cycle exhumed lower to middle crust in Early Cambrian. The Ordovician magmatic arc, associated metamorphism and foreland basin formation characterized the Famatinian cycle. In Late Devonian, the collision of Chilenia and associated high-pressure/low-temperature metamorphism contrasts with the late Palaeozoic accretionary prisms. Contractional deformation in Early to Middle Permian was followed by extension and rhyolitic (Choiyoi) magmatism. Triassic to earliest Jurassic rifting was followed by subduction and extension, dominated by Pacific marine ingressions, during Jurassic and Early Cretaceous. The Late Cretaceous was characterized by uplift and exhumation of the Andean Cordillera. An Atlantic ingression occurred in latest Cretaceous. Cenozoic contraction and uplift pulses alternate with Oligocene extension. Late Cenozoic subduction was characterized by the Pampean flat-subduction, the clockwise block tectonic rotations in the normal subduction segments and the magmatism in Payenia. These processes provide evidence that the Andean tectonic model is far from a straightforward geological evolution.
Stone heritage in Southeast Slovenia
Authors: Golež M. , Mirtič B.
Published: August 2014

The landscape of southeast Slovenia and its heritage in stone is, in terms of geology, primarily identified through the application of various types of sandstone of Miocene age, from those of Lower Miocene found in the wider areas of Celje and Ptuj to those of Middle Miocene found in and around Šmarje pri Jelšah and Rogaška Slatina. The inactive quarries in this region reveal traces of stonemasonry, while the outcrops of clastic sedimentary rocks reveal their diverse geological heritage. Hence, the wealth of natural and cultural heritage of a place is intertwined in one spot, offering an opportunity to make stonemasonry, stonemasons’ products, the traditional technological know-how, as well as arts and sciences, popular. With the stone heritage of southeast Slovenia gravely threatened, the abandoned quarries identified represent potential sites for obtaining natural stone for the purposes of renovating architectural heritage structures in the Slovenian countryside and more widely, like in the case of the revitalization of the abandoned quarry in Strtenica.
Spatially restricted hyaluronan production by Has2 drives epithelial tubulogenesis in vitro
Authors: Soulié Priscilla , Chassot Alexandra , Ernandez Thomas , Montesano Roberto , Féraille Eric
Published: August 2014

Generation of branched tubes from an epithelial bud is a fundamental process in development. We hypothesized that induction of hyaluronan synthase (Has) and production of hyaluronan (HA) drives tubulogenesis in response to morphogenetic cytokines. Treatment of J3B1A mammary cells with transforming growth factor-β1 or renal MDCK and mCCD-N21 cells with hepatocyte growth factor induced strong and specific expression of Has2. Immunostaining revealed that HA was preferentially produced at the tips of growing tubules. Inhibition of HA production, either by 4-methylumbelliferone (4-MU) or by Has2 mRNA silencing, abrogated tubule formation. HA production by J3B1A and mCCD-N21 cells was associated with sustained activation of ERK and S6 phosphorylation. However, silencing of either CD44 or RHAMM (receptor for HA-mediated motility), the major HA receptors, by RNA interference, did not alter tubulogenesis, suggesting that this process is not receptor-mediated.
Serum starvation regulates E-cadherin upregulation via activation of c-Src in non-small-cell lung cancer A549 cells
Authors: Dong Su , Khoo Andrew , Wei Jianxin , Bowser Rachel K. , Weathington Nathaniel M. , Xiao Shuqi , Zhang Lina , Ma Haichun , Zhao Yutong , Zhao Jing
Published: August 2014

E-cadherin is essential for the integrity of adherens junctions between lung epithelial cells, and the loss of E-cadherin allows cell motility and is thought to promote lung cancer metastasis. While the downregulation of E-cadherin expression has been well characterized and is seen with transforming growth factor-β1 (TGF-β1) exposure, few studies have focused on E-cadherin upregulation. Here, we show that serum starvation causes increased E-cadherin expression via the activation of c-Src kinase in non-small-cell lung cancer A549 cells. Serum starvation increased E-cadherin protein levels in a time- and dose-dependent manner. E-cadherin mRNA transcripts were unchanged with starvation, while protein translation inhibition with cycloheximide attenuated E-cadherin protein induction by starvation, suggesting that E-cadherin is regulated at the translational level by serum starvation. c-Src is a nonreceptor tyrosine kinase known to regulate protein translation machinery; serum starvation caused early and sustained activation of c-Src in A549 cells followed by E-cadherin upregulation. Furthermore, overexpression of a dominant negative c-Src attenuated the induction of E-cadherin by serum deprivation. Finally, we observed that TGF-β1 treatment attenuated the serum activation of c-Src as well as E-cadherin expression when cells were deprived of serum. In conclusion, our data demonstrate that the c-Src kinase is activated by serum starvation to increase E-cadherin expression in A549 cells, and these phenomena are antagonized by TGF-β1. These novel observations implicate the c-Src kinase as an upstream inducer of E-cadherin protein translation with serum starvation and TGF-β1 diametrically regulating c-Src kinase activity and thus E-cadherin abundance in A549 cells.
Mechanisms of NFATc3 activation by increased superoxide and reduced hydrogen peroxide in pulmonary arterial smooth muscle
Authors: Ramiro-Diaz Juan Manuel , Giermakowska Wieslawa , Weaver John M. , Jernigan Nikki L. , Gonzalez Bosc Laura V.
Published: August 2014

We recently demonstrated increased superoxide (O2·−) and decreased H2O2 levels in pulmonary arteries of chronic hypoxia-exposed wild-type and normoxic superoxide dismutase 1 (SOD1) knockout mice. We also showed that this reciprocal change in O2·− and H2O2 is associated with elevated activity of nuclear factor of activated T cells isoform c3 (NFATc3) in pulmonary arterial smooth muscle cells (PASMC). This suggests that an imbalance in reactive oxygen species levels is required for NFATc3 activation. However, how such imbalance activates NFATc3 is unknown. This study evaluated the importance of O2·− and H2O2 in the regulation of NFATc3 activity. We tested the hypothesis that an increase in O2·− enhances actin cytoskeleton dynamics and a decrease in H2O2 enhances intracellular Ca2+ concentration, contributing to NFATc3 nuclear import and activation in PASMC. We demonstrate that, in PASMC, endothelin-1 increases O2·− while decreasing H2O2 production through the decrease in SOD1 activity without affecting SOD protein levels. We further demonstrate that O2·− promotes, while H2O2 inhibits, NFATc3 activation in PASMC. Additionally, increased O2·−-to-H2O2 ratio activates NFATc3, even in the absence of a Gq protein-coupled receptor agonist. Furthermore, O2·−-dependent actin polymerization and low intracellular H2O2 concentration-dependent increases in intracellular Ca2+ concentration contribute to NFATc3 activation. Together, these studies define important and novel regulatory mechanisms of NFATc3 activation in PASMC by reactive oxygen species.
Dietary milk fat globule membrane improves endurance capacity in mice
Authors: Haramizu Satoshi , Ota Noriyasu , Otsuka Atsuko , Hashizume Kohjiro , Sugita Satoshi , Hase Tadashi , Murase Takatoshi , Shimotoyodome Akira
Published: August 2014

Milk fat globule membrane (MFGM) comprises carbohydrates, membrane-specific proteins, glycoproteins, phospholipids, and sphingolipids. We evaluated the effects of MFGM consumption over a 12-wk period on endurance capacity and energy metabolism in BALB/c mice. Long-term MFGM intake combined with regular exercise improved endurance capacity, as evidenced by swimming time until fatigue, in a dose-dependent manner. The effect of dietary MFGM plus exercise was accompanied by higher oxygen consumption and lower respiratory quotient, as determined by indirect calorimetry. MFGM intake combined with exercise increased plasma levels of free fatty acids after swimming. After chronic intake of MFGM combined with exercise, the triglyceride content in the gastrocnemius muscle increased significantly. Mice given MFGM combined with exercise had higher mRNA levels of peroxisome proliferator-activated receptor-γ coactivator 1α (Pgc1α) and CPT-1b in the soleus muscle at rest, suggesting that increased lipid metabolism in skeletal muscle contributes, in part, to improved endurance capacity. MFGM treatment with cyclic equibiaxial stretch consisting of 10% elongation at 0.5 Hz with 1 h on and 5 h off increased the Pgc1α mRNA expression of differentiating C2C12 myoblasts in a dose-dependent manner. Supplementation with sphingomyelin increased endurance capacity in mice and Pgc1α mRNA expression in the soleus muscle in vivo and in differentiating myoblasts in vitro. These results indicate that dietary MFGM combined with exercise improves endurance performance via increased lipid metabolism and that sphingomyelin may be one of the components responsible for the beneficial effects of dietary MFGM.
TBC1D1 reduces palmitate oxidation by inhibiting β-HAD activity in skeletal muscle
Authors: Maher A. C. , McFarlan J. , Lally J. , Snook L. A. , Bonen A.
Published: August 2014

In skeletal muscle the Rab-GTPase-activating protein TBC1D1 has been implicated in the regulation of fatty acid oxidation by an unknown mechanism. We determined whether TBC1D1 altered fatty acid utilization via changes in protein-mediated fatty acid transport and/or selected enzymes regulating mitochondrial fatty acid oxidation. We also determined the effects of TBC1D1 on glucose transport and oxidation. Electrotransfection of mouse soleus muscles with TBC1D1 cDNA increased TBC1D1 protein after 2 wk ( P < 0.05), without altering its paralog AS160. TBC1D1 overexpression decreased basal palmitate oxidation (−22%) while blunting 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR)-stimulated palmitate oxidation (−18%). There was a tendency to increase fatty acid esterification (+10 nmol·g−1·60 min−1, P = 0.07), which reflected the reduction in fatty acid oxidation (−12 nmol·g−1·60 min−1). Concomitantly, basal (+21%) and AICAR-stimulated glucose oxidation (+8%) were increased in TBC1D1-transfected muscles relative to their respective controls ( P < 0.05), independent of changes in GLUT4 and glucose transport. The reductions in TBC1D1-mediated fatty acid oxidation could not be attributed to changes in the transporter FAT/CD36, muscle mitochondrial content, CPT1 expression or the expression and phosphorylation of AS160, acetyl-CoA carboxylase, or AMPK. However, TBC1D1 overexpression reduced β-HAD enzyme activity (−18%, P < 0.05). In conclusion, TBC1D1-mediated reduction of muscle fatty acid oxidation appears to occur via inhibition of β-HAD activity.
Mechanisms responsible for the acceleration of pulmonary V̇o2on-kinetics in humans after prolonged endurance training
Authors: Zoladz Jerzy A. , Grassi Bruno , Majerczak Joanna , Szkutnik Zbigniew , Korostyński Michal , Grandys Marcin , Jarmuszkiewicz Wieslawa , Korzeniewski Bernard
Published: August 2014

The effect of prolonged endurance training on the pulmonary V̇o2on- and off-kinetics in humans, in relation to muscle mitochondria biogenesis, is investigated. Eleven untrained physically active men (means ± SD: age 22.4 ± 1.5 years, V̇o2peak3,187 ± 479 ml/min) performed endurance cycling training (4 sessions per week) lasting 20 wk. Training shortened τpof the pulmonary V̇o2on-kinetics during moderate-intensity cycling by ∼19% from 28.3 ± 5.2 to 23.0 ± 4.0 s ( P = 0.005). τpof the pulmonary V̇o2off-kinetics decreased by ∼11% from 33.7 ± 7.2 to 30.0 ± 6.6 ( P = 0.02). Training increased (in vastus lateralis muscle) mitochondrial DNA copy number in relation to nuclear DNA (mtDNA/nDNA) (+53%) ( P = 0.014), maximal citrate synthase (CS) activity (+38%), and CS protein content (+38%) ( P = 0.004), whereas maximal cytochrome c oxidase (COX) activity after training tended to be only slightly (+5%) elevated ( P = 0.08). By applying to the experimental data, our computer model of oxidative phosphorylation (OXPHOS) and using metabolic control analysis, we argue that COX activity is a much better measure of OXPHOS intensity than CS activity. According to the model, in the present study a training-induced increase in OXPHOS activity accounted for about 0–10% of the decrease in τpof muscle and pulmonary V̇o2for the on-transient, whereas the remaining 90–100% is caused by an increase in each-step parallel activation of OXPHOS.
Beneficial effects of elevating cardiac preload on left-ventricular diastolic function and volume during heat stress: implications toward tolerance during a hemorrhagic insult
Authors: Brothers R. M. , Pecini Redi , Dalsgaard M. , Bundgaard-Nielsen Morten , Wilson Thad E. , Secher Niels H. , Crandall Craig G.
Published: August 2014

Volume loading normalizes tolerance to a simulated hemorrhagic challenge in heat-stressed individuals, relative to when these individuals are thermoneutral. The mechanism(s) by which this occurs is unknown. This project tested two unique hypotheses; that is, the elevation of central blood volume via volume loading while heat stressed would 1) increase indices of left ventricular diastolic function, and 2) preserve left ventricular end-diastolic volume (LVEDV) during a subsequent simulated hemorrhagic challenge induced by lower-body negative pressure (LBNP). Indices of left ventricular diastolic function were evaluated in nine subjects during the following conditions: thermoneutral, heat stress, and heat stress after acute volume loading sufficient to return ventricular filling pressures toward thermoneutral levels. LVEDV was also measured in these subjects during the aforementioned conditions prior to and during a simulated hemorrhagic challenge. Heat stress did not change indices of diastolic function. Subsequent volume infusion elevated indices of diastolic function, specifically early diastolic mitral annular tissue velocity ( E′) and early diastolic propagation velocity ( E) relative to both thermoneutral and heat stress conditions ( P < 0.05 for both). Heat stress reduced LVEDV ( P < 0.05), while volume infusion returned LVEDV to thermoneutral levels. The reduction in LVEDV to LBNP was similar between thermoneutral and heat stress conditions, whereas the reduction after volume infusion was attenuated relative to both conditions ( P < 0.05). Absolute LVEDV during LBNP after volume loading was appreciably greater relative to the same level of LBNP during heat stress alone. Thus, rapid volume infusion during heat stress increased indices of left ventricular diastolic function and attenuated the reduction in LVEDV during LBNP, both of which may serve as mechanisms by which volume loading improves tolerance to a combined hyperthermic and hemorrhagic challenge.
Acute rapamycin treatment improved glucose tolerance through inhibition of hepatic gluconeogenesis in rainbow trout (Oncorhynchus mykiss)
Authors: Dai Weiwei , Panserat Stéphane , Terrier Frédéric , Seiliez Iban , Skiba-Cassy Sandrine
Published: August 2014

Our aim was to investigate the potential role of TOR (target of rapamycin) signaling pathway in the regulation of hepatic glucose metabolism in rainbow trout. Fasted fish were first treated with a single intraperitoneal injection of rapamycin or vehicle and then submitted to a second intraperitoneal administration of glucose 4 h later. Our results revealed that intraperitoneal administration of glucose induced hyperglycemia for both vehicle and rapamycin treatments, which peaked at 2 h. Plasma glucose level in vehicle-treated fish was significantly higher than in rapamycin-treated fish at 8 and 17 h, whereas it remained at the basal level in rapamycin-treated fish. Glucose administration significantly enhanced the phosphorylation of Akt and ribosomal protein S6 kinase (S6K1) in vehicle-treated fish, while rapamycin completely abolished the activation of S6K1 in rapamycin-treated fish, without inhibiting the phosphorylation of Akt on Thr-308 or Ser-473. Despite the lack of significant variation in phosphoenolpyruvate carboxykinase mRNA abundance, mRNA abundance for glucokinase (GK), glucose 6-phosphatase (G6Pase) I and II, and fructose 1,6-bisphosphatase (FBPase) was reduced by rapamycin 17 h after glucose administration. The inhibition effect of rapamycin on GK and FBPase was further substantiated at the activity level. The suppression of GK gene expression and activity by rapamycin provided the first in vivo evidence in fish that glucose regulates hepatic GK gene expression and activity through a TORC1-dependent manner. Unlike in mammals, we observed that acute rapamycin treatment improved glucose tolerance through the inhibition of hepatic gluconeogenesis in rainbow trout.
Electrical excitability of the heart in a Chondrostei fish, the Siberian sturgeon (Acipenser baerii)
Authors: Haworth Thomas Eliot , Haverinen Jaakko , Shiels Holly A. , Vornanen Matti
Published: August 2014

Sturgeon (family Acipenseridae) are regarded as living fossils due to their ancient origin and exceptionally slow evolution. To extend our knowledge of fish cardiac excitability to a Chondrostei fish, we examined electrophysiological phenotype of the Siberian sturgeon ( Acipenser baerii) heart with recordings of epicardial ECG, intracellular action potentials (APs), and sarcolemmal ion currents. Epicardial ECG of A. baerii had the typical waveform of the vertebrate ECG with Q-T interval (average duration of ventricular AP) of 650 ± 30 ms and an intrinsic heart rate of 45.5 ± 5 beats min−1at 20°C. Similar to other fish species, atrial AP was shorter in duration (402 ± 33 ms) than ventricular AP (585 ± 40) ( P < 0.05) at 20°C. Densities of atrial and ventricular Na+currents were similar (−47.6 ± 4.5 and −53.2 ± 5.1 pA/pF, respectively) and close to the typical values of teleost hearts. Two major K+currents, the inward rectifier K+current ( IK1), and the delayed rectifier K+current ( IKr) were found under basal conditions in sturgeon cardiomyocytes. The atrial IKr(3.3 ± 0.2 pA/pF) was about twice as large as the ventricular IKr(1.3 ± 0.4 pA/pF) ( P < 0.05) conforming to the typical pattern of teleost cardiac IKr. Divergent from other fishes, the ventricular IK1was remarkably small (−2.5 ± 0.07 pA/pF) and not different from that of the atrial myocytes (−1.9 ± 0.06 pA/pF) ( P > 0.05). Two ligand-gated K+currents were also found: ACh-activated inward rectifier ( IKACh) was present only in atrial cells, while ATP-sensitive K+current ( IKATP) was activated by a mitochondrial blocker, CCCP, in both atrial and ventricular cells. The most striking difference to other fishes appeared in Ca2+currents ( ICa). In atrial myocytes, ICawas predominated by nickel-sensitive and nifedipine-resistant T-type ICa, while ventricular myocytes had mainly nifedipine-sensitive and nickel-resistant L-type ICa. ICaT/ ICaLratio of the sturgeon atrial myocytes (2.42) is the highest value ever measured for a vertebrate species. In ventricular myocytes, ICaT/ ICaLratio was 0.09. With the exception of the large atrial ICaTand small ventricular IK1, electrical excitability of A. baerii heart is similar to that of teleost hearts.
Incomplete distal renal tubular acidosis from a heterozygous mutation of the V-ATPase B1 subunit
Authors: Zhang Jianning , Fuster Daniel G. , Cameron Mary Ann , Quiñones Henry , Griffith Carolyn , Xie Xiao-Song , Moe Orson W.
Published: August 2014

Congenital distal renal tubular acidosis (RTA) from mutations of the B1 subunit of V-ATPase is considered an autosomal recessive disease. We analyzed a distal RTA kindred with a truncation mutation of B1 (p.Phe468fsX487) previously shown to have failure of assembly into the V1domain of V-ATPase. All heterozygous carriers in this kindred have normal plasma HCO3−concentrations and thus evaded the diagnosis of RTA. However, inappropriately high urine pH, hypocitraturia, and hypercalciuria were present either individually or in combination in the heterozygotes at baseline. Two of the heterozygotes studied also had inappropriate urinary acidification with acute ammonium chloride loading and an impaired urine-blood Pco2gradient during bicarbonaturia, indicating the presence of a H+gradient and flux defects. In normal human renal papillae, wild-type B1 is located primarily on the plasma membrane, but papilla from one of the heterozygote who had kidney stones but not nephrocalcinosis showed B1 in both the plasma membrane as well as diffuse intracellular staining. Titration of increasing amounts of the mutant B1 subunit did not exhibit negative dominance over the expression, cellular distribution, or H+pump activity of wild-type B1 in mammalian human embryonic kidney-293 cells and in V-ATPase-deficient Saccharomyces cerevisiae. This is the first demonstration of renal acidification defects and nephrolithiasis in heterozygous carriers of a mutant B1 subunit that cannot be attributable to negative dominance. We propose that heterozygosity may lead to mild real acidification defects due to haploinsufficiency. B1 heterozygosity should be considered in patients with calcium nephrolithiasis and urinary abnormalities such as alkalinuria or hypocitraturia.
Sustainable Deforestation Evaluation Model and System Dynamics Analysis
Authors: Feng Huirong , Lim C. W. , Chen Liqun , Zhou Xinnian , Zhou Chengjun , Lin Yi
Published: August 2014

The current study used the improved fuzzy analytic hierarchy process to construct a sustainable deforestation development evaluation system and evaluation model, which has refined a diversified system to evaluate the theory of sustainable deforestation development. Leveraging the visual image of the system dynamics causal and power flow diagram, we illustrated here that sustainable forestry development is a complex system that encompasses the interaction and dynamic development of ecology, economy, and society and has reflected the time dynamic effect of sustainable forestry development from the three combined effects. We compared experimental programs to prove the direct and indirect impacts of the ecological, economic, and social effects of the corresponding deforest techniques and fully reflected the importance of developing scientific and rational ecological harvesting and transportation technologies. Experimental and theoretical results illustrated that light cableway skidding is an ecoskidding method that is beneficial for the sustainable development of resources, the environment, the economy, and society and forecasted the broad potential applications of light cableway skidding in timber production technology. Furthermore, we discussed the sustainable development countermeasures of forest ecosystems from the aspects of causality, interaction, and harmony.