bluuebunny/crossref_metadata_2025_split huggingface dataset:
Intracellular Ca2+ regulating proteins in vascular smooth muscle cells are altered with type 1 diabetes due to the direct effects of hyperglycemia
Authors: Searls Yvonne M , Loganathan Rajprasad , Smirnova Irina V , Stehno-Bittel Lisa 
Published: February 2010

Abstract

Background
Diminished calcium (Ca2+) transients in response to physiological agonists have been reported in vascular smooth muscle cells (VSMCs) from diabetic animals. However, the mechanism responsible was unclear.

Methodology/Principal Findings
VSMCs from autoimmune type 1 Diabetes Resistant Bio-Breeding (DR-BB) rats and streptozotocin-induced rats were examined for levels and distribution of inositol trisphosphate receptors (IP3R) and the SR Ca2+ pumps (SERCA 2 and 3). Generally, a decrease in IP3R levels and dramatic increase in ryanodine receptor (RyR) levels were noted in the aortic samples from diabetic animals. Redistribution of the specific IP3R subtypes was dependent on the rat model. SERCA 2 was redistributed to a peri-nuclear pattern that was more prominent in the DR-BB diabetic rat aorta than the STZ diabetic rat. The free intracellular Ca2+ in freshly dispersed VSMCs from control and diabetic animals was monitored using ratiometric Ca2+ sensitive fluorophores viewed by confocal microscopy. In control VSMCs, basal fluorescence levels were significantly higher in the nucleus relative to the cytoplasm, while in diabetic VSMCs they were essentially the same. Vasopressin induced a predictable increase in free intracellular Ca2+ in the VSMCs from control rats with a prolonged and significantly blunted response in the diabetic VSMCs. A slow rise in free intracellular Ca2+ in response to thapsigargin, a specific blocker of SERCA was seen in the control VSMCs but was significantly delayed and prolonged in cells from diabetic rats. To determine whether the changes were due to the direct effects of hyperglycemica, experiments were repeated using cultured rat aortic smooth muscle cells (A7r5) grown in hyperglycemic and control conditions. In general, they demonstrated the same changes in protein levels and distribution as well as the blunted Ca2+ responses to vasopressin and thapsigargin as noted in the cells from diabetic animals.

Conclusions/Significance
This work demonstrates that the previously-reported reduced Ca2+ signaling in VSMCs from diabetic animals is related to decreases and/or redistribution in the IP3R Ca2+ channels and SERCA proteins. These changes can be duplicated in culture with high glucose levels.
Axin downregulates TCF-4 transcription via β-catenin, but not p53, and inhibits the proliferation and invasion of lung cancer cells
Authors: Yang Lian-He , Xu Hong-Tao , Han Yang , Li Qing-Chang , Liu Yang , Zhao Yue , Yang Zhi-Qiang , Dong Qian-Ze , Miao Yuan , Dai Shun-Dong , Wang En-Hua 
Published: February 2010

Abstract

Background
We previously reported that overexpression of Axin downregulates T cell factor-4 (TCF-4) transcription. However, the mechanism(s) by which Axin downregulates the transcription and expression of TCF-4 is not clear. It has been reported that β-catenin promotes and p53 inhibits TCF-4 transcription, respectively. The aim of this study was to investigate whether β-catenin and/or p53 is required for Axin-mediated downregulation of TCF-4.

Results
Axin mutants that lack p53/HIPK2 and/or β-catenin binding domains were expressed in lung cancer cells, BE1 (mutant p53) and A549 (wild type p53). Expression of Axin or AxinΔp53 downregulates β-catenin and TCF-4, and knock-down of β-catenin upregulates TCF-4 in BE1 cells. However, expression of AxinΔβ-ca into BE1 cells did not downregulate TCF-4 expression. These results indicate that Axin downregulates TCF-4 transcription via β-catenin. Although overexpression of wild-type p53 also downregulates TCF-4 in BE1 cells, cotransfection of p53 and AxinΔβ-ca did not downregulate TCF-4 further. These results suggest that Axin does not promote p53-mediated downregulation of TCF-4. Axin, AxinΔp53, and AxinΔβ-ca all downregulated β-catenin and TCF-4 in A549 cells. Knock-down of p53 upregulated β-catenin and TCF-4, but cotransfection of AxinΔβ-ca and p53 siRNA resulted in downregulation of β-catenin and TCF-4. These results indicate that p53 is not required for Axin-mediated downregulation of TCF-4. Knock-down or inhibition of GSK-3β prevented Axin-mediated downregulation of TCF-4. Furthermore, expression of Axin and AxinΔp53, prevented the proliferative and invasive ability of BE1 and A549, expression of AxinΔβ-ca could only prevented the proliferative and invasive ability effectively.

Conclusions
Axin downregulates TCF-4 transcription via β-catenin and independently of p53. Axin may also inhibits the proliferation and invasion of lung cancer cells via β-catenin and p53.
The mutation T477A in HIV-1 reverse transcriptase (RT) restores normal proteolytic processing of RT in virus with Gag-Pol mutated in the p51-RNH cleavage site
Authors: Abram Michael E , Sarafianos Stefan G , Parniak Michael A 
Published: February 2010

Abstract

Background
The p51 subunit of the HIV-1 reverse transcriptase (RT) p66/p51 heterodimer arises from proteolytic cleavage of the RT p66 subunit C-terminal ribonuclease H (RNH) domain during virus maturation. Our previous work showed that mutations in the RT p51↓RNH cleavage site resulted in virus with defects in proteolytic processing of RT and significantly attenuated infectivity. In some cases, virus fitness was restored after repeated passage of mutant viruses, due to reversion of the mutated sequences to wild-type. However, in one case, the recovered virus retained the mutated p51↓RNH cleavage site but also developed an additional mutation, T477A, distal to the cleavage site. In this study we have characterized in detail the impact of the T477A mutation on intravirion processing of RT.

Results
While the T477A mutation arose during serial passage only with the F440V mutant background, introduction of this substitution into a variety of RT p51↓RNH cleavage site lethal mutant backgrounds was able to restore substantial infectivity and normal RT processing to these mutants. T477A had no phenotypic effect on wild-type HIV-1. We also evaluated the impact of T477A on the kinetics of intravirion Gag-Pol polyprotein processing of p51↓RNH cleavage site mutants using the protease inhibitor ritonavir. Early processing intermediates accumulated in p51↓RNH cleavage site mutant viruses, whereas introduction of T477A promoted the completion of processing and formation of the fully processed RT p66/p51 heterodimer.

Conclusions
This work highlights the extraordinary plasticity of HIV-1 in adapting to seemingly lethal mutations that prevent RT heterodimer formation during virion polyprotein maturation. The ability of T477A to restore RT heterodimer formation and thus intravirion stability of the enzyme may arise from increased conformation flexibility in the RT p51↓RNH cleavage site region, due to loss of a hydrogen bond associated with the normal threonine residue, thereby enabling proteolytic cleavage near the normal RT p51↓RNH cleavage site.
Differential impact of ageing on cellular and humoral immunity to a persistent murine γ-herpesvirus
Authors: Yager Eric J , Kim In-Jeong , Freeman Michael L , Lanzer Kathleen G , Burkum Claire E , Cookenham Tres , Woodland David L , Blackman Marcia A 
Published: February 2010

AbstractBackgroundOncogenic γ-herpesviruses establish life-long infections in their hosts and control of these latent infections is dependent on continual immune surveillance. Immune function declines with age, raising the possibility that immune control of γ-herpesvirus infection becomes compromised with increasing age, allowing viral reactivation and/or increased latent load, both of which are associated with the development of malignancies.ResultsIn this study, we use the experimental mouse γ-herpesvirus model, γHV68, to investigate viral immunity in aged mice. We found no evidence of viral recrudescence or increased latent load in aged latently-infected mice, suggesting that effective immune control of γ-herpesvirus infection remains intact with ageing. As both cellular and humoral immunity have been implicated in host control of γHV68 latency, we independently examined the impact of ageing on γHV68-specific CD8 T cell function and antibody responses. Virus-specific CD8 T cell numbers and cytolytic function were not profoundly diminished with age. In contrast, whereas ELISA titers of virus-specific IgG were maintained over time, there was a progressive decline in neutralizing activity. In addition, although aged mice were able to control de novo acute infection with only slightly delayed viral clearance, serum titers of neutralizing antibody were reduced in aged mice as compared to young mice.ConclusionAlthough there is no obvious loss of immune control of latent virus, these data indicate that ageing has differential impacts on anti-viral cellular and humoral immune protection during persistent γHV68 infection. This observation has potential relevance for understanding γ-herpesvirus immune control during disease-associated or therapeutic immunosuppression.
Small interference RNA profiling reveals the essential role of human membrane trafficking genes in mediating the infectious entry of dengue virus
Authors: Ang Firzan , Wong Andrew Phui Yew , Ng Mary Mah-Lee , Chu Justin Jang Hann 
Published: February 2010

Abstract

Background
Dengue virus (DENV) is the causative agent of Dengue fever and the life-threatening Dengue Haemorrhagic fever or Dengue shock syndrome. In the absence of anti-viral agents or vaccine, there is an urgent need to develop an effective anti-viral strategy against this medically important viral pathogen. The initial interplay between DENV and the host cells may represent one of the potential anti-viral targeting sites. Currently the involvements of human membrane trafficking host genes or factors that mediate the infectious cellular entry of dengue virus are not well defined.

Results
In this study, we have used a targeted small interfering RNA (siRNA) library to identify and profile key cellular genes involved in processes of endocytosis, cytoskeletal dynamics and endosome trafficking that are important and essential for DENV infection. The infectious entry of DENV into Huh7 cells was shown to be potently inhibited by siRNAs targeting genes associated with clathrin-mediated endocytosis. The important role of clathrin-mediated endocytosis was confirmed by the expression of well-characterized dominant-negative mutants of genes in this pathway and by using the clathrin endocytosis inhibitor chlorpromazine. Furthermore, DENV infection was shown to be sensitive to the disruption of human genes in regulating the early to late endosomal trafficking as well as the endosomal acidic pH. The importance and involvement of both actin and microtubule dynamics in mediating the infectious entry of DENV was also revealed in this study.

Conclusions
Together, the findings from this study have provided a detail profiling of the human membrane trafficking cellular genes and the mechanistic insight into the interplay of these host genes with DENV to initiate an infection, hence broadening our understanding on the entry pathway of this medically important viral pathogen. These data may also provide a new potential avenue for development of anti-viral strategies and treatment of DENV infection.
Remodeling of inhibitory synaptic connections in developing ferret visual cortex
Authors: Dalva Matthew B 
Published: February 2010

Abstract
Background
In the visual cortex, as in many other regions of the developing brain, excitatory synaptic connections undergo substantial remodeling during development. While evidence suggests that local inhibitory synapses may behave similarly, the extent and mechanisms that mediate remodeling of inhibitory connections are not well understood.

Results
Using scanning laser photostimulation in slices of developing ferret visual cortex, we assessed the overall patterns of developing inhibitory and excitatory synaptic connections converging onto individual neurons. Inhibitory synaptic inputs onto pyramidal neurons in cortical layers 2 and 3 were already present as early as postnatal day 20, well before eye opening, and originated from regions close to the recorded neurons. During the ensuing 2 weeks, the numbers of synaptic inputs increased, with the numbers of inhibitory (and excitatory) synaptic inputs peaking near the time of eye opening. The pattern of inhibitory inputs refined rapidly prior to the refinement of excitatory inputs. By uncaging the neurotransmtter GABA in brain slices from animals of different ages, we find that this rapid refinement correlated with a loss of excitatory activity by GABA.

Conclusion
Inhibitory synapses, like excitatory synapses, undergo significant postnatal remodeling. The time course of the remodeling of inhibitory connections correlates with the emergence of orientation tuning in the visual cortex, implicating these rearrangements in the genesis of adult cortical response properties.
Vein of Galen arteriovenous malformation with PAPVR and use of serial B-type natriuretic peptide levels in the management: a case report and review of the literature
Authors: Purdy Isabell B , Halnon Nancy , Singh Namrata , Milisavljevic Vladana 
Published: February 2010

AbstractBackgroundArteriovenous malformation of the vein of Galen with partial anomalous pulmonary venous return can lead to a critically challenging condition associated with a high morbidity and mortality.Case reportWe report a case of a full term infant born with a vein of Gallen arteriovenous malformation complicated by partial anomalous pulmonary venous return and congestive heart failure where B-type natriuretic peptide was used as a vital tool in clinical assessment and treatment management.ConclusionsRapid diagnosis and treatment in infants with complex conditions such as this are imperative to expedite appropriate treatments, preventing long term negative outcome.
Immunity of replicating Mu to self-integration: a novel mechanism employing MuB protein
Authors: Ge Jun , Lou Zheng , Harshey Rasika M 
Published: February 2010

Abstract
We describe a new immunity mechanism that protects actively replicating/transposing Mu from self-integration. We show that this mechanism is distinct from the established cis-immunity mechanism, which operates by removal of MuB protein from DNA adjacent to Mu ends. MuB normally promotes integration into DNA to which it is bound, hence its removal prevents use of this DNA as target. Contrary to what might be expected from a cis-immunity mechanism, strong binding of MuB was observed throughout the Mu genome. We also show that the cis-immunity mechanism is apparently functional outside Mu ends, but that the level of protection offered by this mechanism is insufficient to explain the protection seen inside Mu. Thus, both strong binding of MuB inside and poor immunity outside Mu testify to a mechanism of immunity distinct from cis-immunity, which we call 'Mu genome immunity'. MuB has the potential to coat the Mu genome and prevent auto-integration as previously observed in vitro on synthetic A/T-only DNA, where strong MuB binding occluded the entire bound region from Mu insertions. The existence of two rival immunity mechanisms within and outside the Mu genome, both employing MuB, suggests that the replicating Mu genome must be segregated into an independent chromosomal domain. We propose a model for how formation of a 'Mu domain' may be aided by specific Mu sequences and nucleoid-associated proteins, promoting polymerization of MuB on the genome to form a barrier against self-integration.
Serum neutrophil gelatinase-associated lipocalin at inception of renal replacement therapy predicts survival in critically ill patients with acute kidney injury
Authors: Kümpers Philipp , Hafer Carsten , Lukasz Alexander , Lichtinghagen Ralf , Brand Korbinian , Fliser Danilo , Faulhaber-Walter Robert , Kielstein Jan T 
Published: February 2010

Abstract
Introduction
Neutrophil gelatinase-associated lipocalin (NGAL) is a promising novel biomarker that correlates with the severity and outcome of acute kidney injury (AKI). However, its prognostic utility during the late course of AKI, especially in patients that require renal replacement therapy (RRT) remains unknown. The aim of this study was to evaluate the predictive value of serum NGAL in patients with established AKI at inception of RRT in the intensive care unit (ICU).

Methods
Serum NGAL (ELISA methodology) was measured in 109 critically ill patients with AKI at inception of RRT in 7 ICUs of a tertiary care university hospital. The primary outcome studied was 28-day mortality. Secondary outcome measures were ICU length of stay, ventilator-free days, and renal recovery at day 28.

Results
There was a significant difference in serum NGAL between healthy subjects (median [interquartile range] 39.0 [37.5-42.75] ng/mL), critically ill patients with systemic inflammatory response syndrome (SIRS) (297 [184-490] ng/mL), and critically ill patients with sepsis (708 [365-1301] ng/mL; P < 0.0001), respectively. Multiple linear regression showed that NGAL levels were independently related to the severity of AKI and the extent of systemic inflammation. NGAL levels were higher in non-survivors (430 [303-942] ng/mL) compared to survivors (298 [159-506] ng/mL; P = 0.004). Consistently, Cox proportional hazards regression analysis identified NGAL as a strong independent predictor for 28-day survival (hazard ratio 1.6 (95% confidence interval [CI] 1.15 - 2.23), P = 0.005).

Conclusions
This is the first prospective evaluation of serum NGAL as an outcome-specific biomarker in critically ill patients at initiation of RRT. The results from this study indicate that serum NGAL is as an independent predictor of 28-day mortality in ICU patients with dialysis-dependent AKI.
Gene Expression Profiling for Survival Prediction in Pediatric Rhabdomyosarcomas: A Report From the Children's Oncology Group
Authors: Davicioni Elai , Anderson James R. , Buckley Jonathan D. , Meyer William H. , Triche Timothy J. 
Published: February 2010

PurposeWe investigated whether tumors from diagnostic biopsies of primary rhabdomyosarcoma (RMS) contain relevant prognostic information in the form of gene expression signatures that can be used to model and predict outcome of patients.Patients and MethodsA 22,000-probe set microarray was used to evaluate 120 RMS specimens and correlate gene expression patterns to survival. Multivariate gene expression models or metagenes were developed using cross-validated Cox regression proportional hazards modeling and were evaluated using Kaplan-Meier analysis.ResultsA 34-metagene, based on expression patterns of 34 genes, was highly predictive of outcome. It was not highly correlated with individual clinical risk factors such as patient age, stage, tumor size, or histology. However, it was correlated with a risk classification used by the Children's Oncology Group and the biologic subsets of alveolar histology tumors.ConclusionThese data support further evaluation of RMS metagenes to discriminate patients with good prognosis from those with poor prognosis, with the potential to direct risk-adapted therapy.
Relationship Between Plasma Estradiol Levels and Estrogen-Responsive Gene Expression in Estrogen Receptor–Positive Breast Cancer in Postmenopausal Women
Authors: Dunbier Anita K. , Anderson Helen , Ghazoui Zara , Folkerd Elizabeth J. , A'Hern Roger , Crowder Robert J. , Hoog Jeremy , Smith Ian E. , Osin Peter , Nerurkar Ashutosh , Parker Joel S. , Perou Charles M. , Ellis Matthew J. , Dowsett Mitch 
Published: February 2010

Purpose To determine whether plasma estradiol (E2) levels are related to gene expression in estrogen receptor (ER)–positive breast cancers in postmenopausal women. Materials and Methods Genome-wide RNA profiles were obtained from pretreatment core-cut tumor biopsies from 104 postmenopausal patients with primary ER-positive breast cancer treated with neoadjuvant anastrozole. Pretreatment plasma E2 levels were determined by highly sensitive radioimmunoassay. Genes were identified for which expression was correlated with pretreatment plasma E2 levels. Validation was performed in an independent set of 73 ER-positive breast cancers. Results The expression of many known estrogen-responsive genes and gene sets was highly significantly associated with plasma E2 levels (eg, TFF1/pS2, GREB1, PDZK1 and PGR; P < .005). Plasma E2 explained 27% of the average expression of these four average estrogen-responsive genes (ie, AvERG; r = 0.51; P < .0001), and a standardized mean of plasma E2 levels and ER transcript levels explained 37% (r, 0.61). These observations were validated in an independent set of 73 ER-positive tumors. Exploratory analysis suggested that addition of the nuclear coregulators in a multivariable analysis with ER and E2 levels might additionally improve the relationship with the AvERG. Plasma E2 and the standardized mean of E2 and ER were both significantly correlated with 2-week Ki67, a surrogate marker of clinical outcome (r = −0.179; P = .05; and r = −0.389; P = .0005, respectively). Conclusion Plasma E2 levels are significantly associated with gene expression of ER-positive breast cancers and should be considered in future genomic studies of ER-positive breast cancer. The AvERG is a new experimental tool for the study of putative estrogenic stimuli of breast cancer.
Comparison of Two Doses of Imatinib for the Treatment of Unresectable or Metastatic Gastrointestinal Stromal Tumors: A Meta-Analysis of 1,640 Patients
Authors:   Gastrointestinal Stromal Tumor Meta-Analysis Group (MetaGIST)
Published: February 2010

Purpose The Gastrointestinal Stromal Tumor Meta-Analysis Group (MetaGIST) project aims to additionally explore the data of the two large, randomized, cooperative-group studies comparing two doses of imatinib (400 mg daily v twice daily) in 1,640 patients with advanced GIST. Methods End points were progression-free survival (PFS) and overall survival (OS). Investigated cofactors included age, sex, performance status (PS), primary tumor site, time from diagnosis, prior therapies, baseline biology, and KIT/PDGFRα mutations for a subset of 772 patients. Univariate and multivariate models were used for the analysis. Results At a median follow-up of 45 months, a small but significant PFS advantage was documented for the high-dose arm. OS was identical in the two arms. The multivariate prognostic models included the following adverse factors: male sex, poor PS, and high baseline neutrophils counts (PFS and OS); low hemoglobin and GIST from small bowel origin (PFS); and advanced age, large tumor size, low albumin level, and prior chemotherapy (OS). In patients analyzed for mutations, patients with wild type, patients with KIT exon 9 mutations, and patients with other mutations had worse prognoses than patients with KIT exon 11 mutations for both end points. The mutation status was the only predictive factor for the PFS benefit attributed to high-dose treatment that resulted in significantly longer PFS (and higher objective response rate) for patients with KIT exon 9 mutations. Conclusion This analysis confirms a small PFS advantage of high-dose imatinib, essentially among patients with KIT exon 9 mutations, but no OS advantage.