bluuebunny/crossref_metadata_2025 huggingface dataset:
Detecting the symplesiomorphy trap: a multigene phylogenetic analysis of terebelliform annelids
Authors: Zhong Min , Hansen Benjamin , Nesnidal Maximilian , Golombek Anja , Halanych Kenneth M , Struck Torsten H
Published: December 2011

Background

For phylogenetic reconstructions, conflict in signal is a potential problem for tree reconstruction. For instance, molecular data from different cellular components, such as the mitochondrion and nucleus, may be inconsistent with each other. Mammalian studies provide one such case of conflict where mitochondrial data, which display compositional biases, support the Marsupionta hypothesis, but nuclear data confirm the Theria hypothesis. Most observations of compositional biases in tree reconstruction have focused on lineages with different composition than the majority of the lineages under analysis. However in some situations, the position of taxa that lack compositional bias may be influenced rather than the position of taxa that possess compositional bias. This situation is due to apparent symplesiomorphic characters and known as "the symplesiomorphy trap".

Results

Herein, we report an example of the sympleisomorphy trap and how to detect it. Worms within Terebelliformia (sensu Rouse & Pleijel 2001) are mainly tube-dwelling annelids comprising five 'families': Alvinellidae, Ampharetidae, Terebellidae, Trichobranchidae and Pectinariidae. Using mitochondrial genomic data, as well as data from the nuclear 18S, 28S rDNA and elongation factor-1α genes, we revealed incongruence between mitochondrial and nuclear data regarding the placement of Trichobranchidae. Mitochondrial data favored a sister relationship between Terebellidae and Trichobranchidae, but nuclear data placed Trichobranchidae as sister to an Ampharetidae/Alvinellidae clade. Both positions have been proposed based on morphological data.

Conclusions

Our investigation revealed that mitochondrial data of Ampharetidae and Alvinellidae exhibited strong compositional biases. However, these biases resulted in a misplacement of Trichobranchidae, rather than Alvinellidae and Ampharetidae. Herein, we document that Trichobranchidae was apparently caught in the symplesiomorphy trap suggesting that in certain situations even homologies can be misleading.
Expression QTL mapping in regulatory and helper T cells from the BXD family of strains reveals novel cell-specific genes, gene-gene interactions and candidate genes for auto-immune disease
Authors: Alberts Rudi , Chen Hairong , Pommerenke Claudia , Smit August B , Spijker Sabine , Williams Robert W , Geffers Robert , Bruder Dunja , Schughart Klaus
Published: December 2011

Background

Regulatory T cells (Tregs) play an essential role in the control of the immune response. Treg cells represent important targets for therapeutic interventions of the immune system. Therefore, it will be very important to understand in more detail which genes are specifically activated in Treg cells versus T helper (Th) cells, and which gene regulatory circuits may be involved in specifying and maintaining Treg cell homeostasis.

Results

We isolated Treg and Th cells from a genetically diverse family of 31 BXD type recombinant inbred strains and the fully inbred parental strains of this family--C57BL/6J and DBA/2J. Subsequently genome-wide gene expression studies were performed from the isolated Treg and Th cells. A comparative analysis of the transcriptomes of these cell populations allowed us to identify many novel differentially expressed genes. Analysis of cis- and trans-expression Quantitative Trait Loci (eQTLs) highlighted common and unique regulatory mechanisms that are active in the two cell types. Trans-eQTL regions were found for the Treg functional genesNrp1, Stat3andIkzf4. Analyses of the respective QTL intervals suggested several candidate genes that may be involved in regulating these genes in Treg cells. Similarly, possible candidate genes were found which may regulate the expression ofF2rl1, Ctla4, Klrb1f. In addition, we identified a focused group of candidate genes that may be important for the maintenance of self-tolerance and the prevention of allergy.

Conclusions

Variation of expression across the strains allowed us to find many novel gene-interaction networks in both T cell subsets. In addition, these two data sets enabled us to identify many differentially expressed genes and to nominate candidate genes that may have important functions for the maintenance of self-tolerance and the prevention of allergy.
Genome-wide transcriptional profiling of peripheral blood leukocytes from cattle infected with Mycobacterium bovis reveals suppression of host immune genes
Authors: Killick Kate E , Browne John A , Park Stephen DE , Magee David A , Martin Irene , Meade Kieran G , Gordon Stephen V , Gormley Eamonn , O'Farrelly Cliona , Hokamp Karsten , MacHugh David E
Published: December 2011

Background

Mycobacterium bovisis the causative agent of bovine tuberculosis (BTB), a pathological infection with significant economic impact. Recent studies have highlighted the role of functional genomics to better understand the molecular mechanisms governing the host immune response toM. bovisinfection. Furthermore, these studies may enable the identification of novel transcriptional markers of BTB that can augment current diagnostic tests and surveillance programmes. In the present study, we have analysed the transcriptome of peripheral blood leukocytes (PBL) from eightM. bovis-infected and eight control non-infected age-matched and sex-matched Holstein-Friesian cattle using the Affymetrix®GeneChip®Bovine Genome Array with 24,072 gene probe sets representing more than 23,000 gene transcripts.

Results

Control and infected animals had similar mean white blood cell counts. However, the mean number of lymphocytes was significantly increased in the infected group relative to the control group (P= 0.001), while the mean number of monocytes was significantly decreased in the BTB group (P= 0.002). Hierarchical clustering analysis using gene expression data from all 5,388 detectable mRNA transcripts unambiguously partitioned the animals according to their disease status. In total, 2,960 gene transcripts were differentially expressed (DE) between the infected and control animal groups (adjustedP-value threshold ≤ 0.05); with the number of gene transcripts showing decreased relative expression (1,563) exceeding those displaying increased relative expression (1,397). Systems analysis using the Ingenuity®Systems Pathway Analysis (IPA) Knowledge Base revealed an over-representation of DE genes involved in theimmune responsefunctional category. More specifically, 64.5% of genes in theaffects immune responsesubcategory displayed decreased relative expression levels in the infected animals compared to the control group.

Conclusions

This study demonstrates that genome-wide transcriptional profiling of PBL can distinguish activeM. bovis-infected animals from control non-infected animals. Furthermore, the results obtained support previous investigations demonstrating that mycobacterial infection is associated with host transcriptional suppression. These data support the use of transcriptomic technologies to enable the identification of robust, reliable transcriptional markers of activeM. bovisinfection.
The effect of conditional EFNB1 deletion in the T cell compartment on T cell development and function
Authors: Jin Wei , Qi Shijie , Luo Hongyu
Published: December 2011

Background

Eph kinases are the largest family of cell surface receptor tyrosine kinases. The ligands of Ephs, ephrins (EFNs), are also cell surface molecules. Ephs interact with EFNs transmitting signals in both directions, i.e., from Ephs to EFNs and from EFNs to Ephs. EFNB1 is known to be able to co-stimulate T cells in vitro and to modulate thymocyte development in a model of foetal thymus organ culture. To further understand the role of EFNB1 in T cell immunity, we generated T-cell-specific EFNB1 gene knockout mice to assess T cell development and function in these mice.

Results

The mice were of normal size and cellularity in the thymus and spleen and had normal T cell subpopulations in these organs. The bone marrow progenitors from KO mice and WT control mice repopulated host spleen T cell pool to similar extents. The activation and proliferation of KO T cells was comparable to that of control mice. Naïve KO CD4 cells showed an ability to differentiate into Th1, Th2, Th17 and Treg cells similar to control CD4 cells.

Conclusions

Our results suggest that the function of EFNB1 in the T cell compartment could be compensated by other members of the EFN family, and that such redundancy safeguards the pivotal roles of EFNB1 in T cell development and function.
Characterization of a proximal Sp1 response element in the mouse Dlk2 gene promoter
Authors: Rivero Samuel , Ruiz-García Almudena , Díaz-Guerra María JM , Laborda Jorge , García-Ramírez José J
Published: December 2011

Background

DLK2 is an EGF-like membrane protein, closely related to DLK1, which is involved in adipogenesis. Both proteins interact with the NOTCH1 receptor and are able to modulate its activation. The expression of the gene Dlk2 is coordinated with that of Dlk1 in several tissues and cell lines. Unlike Dlk1, the mouse Dlk2 gene and its locus at chromosome 17 are not fully characterized.

Results

The goal of this work was the characterization of Dlk2 mRNA, as well as the analysis of the mechanisms that control its basal transcription. First, we analyzed the Dlk2 transcripts expressed by several mouse cells lines and tissues, and mapped the transcription start site by 5' Rapid Amplification of cDNA Ends. In silico analysis revealed that Dlk2 possesses a TATA-less promoter containing minimal promoter elements associated with a CpG island, and sequences for Inr and DPE elements. Besides, it possesses six GC-boxes, considered as consensus sites for the transcription factor Sp1. Indeed, we report that Sp1 directly binds to the Dlk2 promoter, activates its transcription, and regulates its level of expression.

Conclusions

Our results provide the first characterization of Dlk2 transcripts, map the location of the Dlk2 core promoter, and show the role of Sp1 as a key regulator of Dlk2 transcription, providing new insights into the molecular mechanisms that contribute to the expression of the Dlk2 gene.
Kalirin-7 is necessary for normal NMDA receptor-dependent synaptic plasticity
Authors: Lemtiri-Chlieh Fouad , Zhao Liangfang , Kiraly Drew D , Eipper Betty A , Mains Richard E , Levine Eric S
Published: December 2011

Background

Dendritic spines represent the postsynaptic component of the vast majority of excitatory synapses present in the mammalian forebrain. The ability of spines to rapidly alter their shape, size, number and receptor content in response to stimulation is considered to be of paramount importance during the development of synaptic plasticity. Indeed, long-term potentiation (LTP), widely believed to be a cellular correlate of learning and memory, has been repeatedly shown to induce both spine enlargement and the formation of new dendritic spines. In our studies, we focus on Kalirin-7 (Kal7), a Rho GDP/GTP exchange factor (Rho-GEF) localized to the postsynaptic density that plays a crucial role in the development and maintenance of dendritic spines both in vitro and in vivo. Previous studies have shown that mice lacking Kal7 (Kal7KO) have decreased dendritic spine density in the hippocampus as well as focal hippocampal-dependent learning impairments.

Results

We have performed a detailed electrophysiological characterization of the role of Kal7 in hippocampal synaptic plasticity. We show that loss of Kal7 results in impaired NMDA receptor-dependent LTP and long-term depression, whereas a NMDA receptor-independent form of LTP is shown to be normal in the absence of Kal7.

Conclusions

These results indicate that Kal7 is an essential and selective modulator of NMDA receptor-dependent synaptic plasticity in the hippocampus.
Evaluation of coronary blood flow velocity during cardiac arrest with circulation maintained through mechanical chest compressions in a porcine model
Authors: Wagner Henrik , Madsen Hardig Bjarne , Steen Stig , Sjoberg Trygve , Harnek Jan , Olivecrona Goran K
Published: December 2011

Background

Mechanical chest compressions (CCs) have been shown capable of maintaining circulation in humans suffering cardiac arrest for extensive periods of time. Reports have documented a visually normalized coronary blood flow during angiography in such cases (TIMI III flow), but it has never been actually measured. Only indirect measurements of the coronary circulation during cardiac arrest with on-going mechanical CCs have been performed previously through measurement of the coronary perfusion pressure (CPP). In this study our aim was to correlate average peak coronary flow velocity (APV) to CPP during mechanical CCs.

Methods

In a closed chest porcine model, cardiac arrest was established through electrically induced ventricular fibrillation (VF) in eleven pigs. After one minute, mechanical chest compressions were initiated and then maintained for 10 minutes upon which the pigs were defibrillated. Measurements of coronary blood flow in the left anterior descending artery were made at baseline and during VF with a catheter based Doppler flow fire measuring APV. Furthermore measurements of central (thoracic) venous and arterial pressures were also made in order to calculate the theoretical CPP.

Results

Average peak coronary flow velocity was significantly higher compared to baseline during mechanical chests compressions and this was observed during the entire period of mechanical chest compressions (12 - 39% above baseline). The APV slowly declined during the 10 min period of mechanical chest compressions, but was still higher than baseline at the end of mechanical chest compressions. CPP was simultaneously maintained at > 20 mmHg during the 10 minute episode of cardiac arrest.

Conclusion

Our study showed good correlation between CPP and APV which was highly significant, during cardiac arrest with on-going mechanical CCs in a closed chest porcine model. In addition APV was even higher during mechanical CCs compared to baseline. Mechanical CCs can, at minimum, re-establish coronary blood flow in non-diseased coronary arteries during cardiac arrest.
Identification of novel mutations in Chinese Hans with autosomal dominant polycystic kidney disease
Authors: Yu Chaowen , Yang Yuan , Zou Lin , Hu Zhangxue , Li Jing , Liu Yunqiang , Ma Yongxin , Ma Mingyi , Su Dan , Zhang Sizhong
Published: December 2011

Background

Autosomal dominant polycystic kidney disease (ADPKD) is the most common inherited renal disease with an incidence of 1 in 400 to 1000. The disease is genetically heterogeneous, with two genes identified: PKD1 (16p13.3) and PKD2 (4q21). Molecular diagnosis of the disease in at-risk individuals is complicated due to the structural complexity of PKD1 gene and the high diversity of the mutations. This study is the first systematic ADPKD mutation analysis of both PKD1 and PKD2 genes in Chinese patients using denaturing high-performance liquid chromatography (DHPLC).

Methods

Both PKD1 and PKD2 genes were mutation screened in each proband from 65 families using DHPLC followed by DNA sequencing. Novel variations found in the probands were checked in their family members available and 100 unrelated normal controls. Then the pathogenic potential of the variations of unknown significance was examined by evolutionary comparison, effects of amino acid substitutions on protein structure, and effects of splice site alterations using online mutation prediction resources.

Results

A total of 92 variations were identified, including 27 reported previously. Definitely pathogenic mutations (ten frameshift, ten nonsense, two splicing defects and one duplication) were identified in 28 families, and probably pathogenic mutations were found in an additional six families, giving a total detection level of 52.3% (34/65). About 69% (20/29) of the mutations are first reported with a recurrent mutation rate of 31%.

Conclusions

Mutation study of PKD1 and PKD2 genes in Chinese Hans with ADPKD may contribute to a better understanding of the genetic diversity between different ethnic groups and enrich the mutation database. Besides, evaluating the pathogenic potential of novel variations should also facilitate the clinical diagnosis and genetic counseling of the disease.
Association analysis identifies ZNF750 regulatory variants in psoriasis
Authors: Birnbaum Ramon Y , Hayashi Genki , Cohen Idan , Poon Annie , Chen Haoyan , Lam Ernest T , Kwok Pui-Yan , Birk Ohad S , Liao Wilson
Published: December 2011

Background

Mutations in the ZNF750 promoter and coding regions have been previously associated with Mendelian forms of psoriasis and psoriasiform dermatitis. ZNF750 encodes a putative zinc finger transcription factor that is highly expressed in keratinocytes and represents a candidate psoriasis gene.

Methods

We examined whether ZNF750 variants were associated with psoriasis in a large case-control population. We sequenced the promoter and exon regions of ZNF750 in 716 Caucasian psoriasis cases and 397 Caucasian controls.

Results

We identified a total of 47 variants, including 38 rare variants of which 35 were novel. Association testing identified two ZNF750 haplotypes associated with psoriasis (p < 0.05). We also identified an excess of rare promoter and 5'untranslated region (UTR) variants in psoriasis cases compared to controls (p = 0.041), whereas there was no significant difference in the number of rare coding and rare 3' UTR variants. Using a promoter functional assay in stimulated human primary keratinocytes, we showed that four ZNF750 promoter and 5' UTR variants displayed a 35-55% reduction of ZNF750 promoter activity, consistent with the promoter activity reduction seen in a Mendelian psoriasis family with a ZNF750 promoter variant. However, the rare promoter and 5' UTR variants identified in this study did not strictly segregate with the psoriasis phenotype within families.

Conclusions

Two haplotypes of ZNF750 and rare 5' regulatory variants of ZNF750 were found to be associated with psoriasis. These rare 5' regulatory variants, though not causal, might serve as a genetic modifier of psoriasis.
Preliminary study: Treatment with intramuscular interferon beta-1a results in increased levels of IL-12Rβ2+ and decreased levels of IL23R+ CD4+ T - Lymphocytes in multiple sclerosis
Authors: Kress-Bennett Jennifer M , Ehrlich Garth D , Bruno Ashley , Post J Christopher , Hu Fen Z , Scott Thomas F
Published: December 2011

Background

There are a lack of biomarkers which can be used to predict clinical outcomes for multiple sclerosis (MS) patients receiving interferon beta (IFN-β). Thus the objective of this study was to characterize changes in CD4+ T-lymphocyte expression in an unbiased manner following initiation of intramuscular (IM) IFN-β-1a treatment, and then to verify those findings using marker-specific assays.

Methods

Peripheral blood specimens were collected from twenty MS patients before and after treatment with intramuscular (IM) IFN-β-1a and were used for isolation of mononuclear cells (PBMCs). mRNA expression patterns of negatively-selected CD4+ T-cells from the PBMCs were analyzed using microarray gene expression technology. IL-12 and IL-23 receptor levels on PBMC-derived CD4+ T-cells were analyzed by flow cytometry. The phosphorylation status of Stat4 was measured by performing densitometry on western blots.

Results

Microarray analyses demonstrated that mRNA expression of the IL-12Rβ2 gene was uniformly up-regulated in response to IFN-β-1a treatment and was associated with an increased number of IL-12Rβ2+ CD4+ T-cells by flow cytometry in 4 of 6 patients. This finding was substantiated by demonstrating that Stat4 phosphorylation, a transcription factor for IL-12, was increased after treatment. Conversely, the number of IL-23R+ CD4+ T-cells was decreased following treatment.

Conclusions

The IL-12 receptor shares a common subunit, the IL-12Rβ2, with the IL-23 receptor. Both of these receptors have a probable role in regulating IL-17 and TH-17 cells, important mediators of inflammation in multiple sclerosis (MS). Thus, the changes in the numbers of CD4+ T-cells expressing these receptors in response to IFN-β-1a treatment may point to an important mechanism of action for this drug, but further large scale studies are needed to confirm these preliminary observations.
Neuronal markers are expressed in human gliomas and NSE knockdown sensitizes glioblastoma cells to radiotherapy and temozolomide
Authors: Yan Tao , Skaftnesmo Kai Ove , Leiss Lina , Sleire Linda , Wang Jian , Li Xingang , Enger Per Øyvind
Published: December 2011

Background

Expression of neuronal elements has been identified in various glial tumors, and glioblastomas (GBMs) with neuronal differentiation patterns have reportedly been associated with longer survival. However, the neuronal class III β-tubulin has been linked to increasing malignancy in astrocytomas. Thus, the significance of neuronal markers in gliomas is not established.

Methods

The expressions of class III β-tubulin, neurofilament protein (NFP), microtubule-associated protein 2 (MAP2) and neuron-specific enolase (NSE) were investigated in five GBM cell lines and two GBM biopsies with immunocytochemistry and Western blot. Moreover, the expression levels were quantified by real-time qPCR under different culture conditions. Following NSE siRNA treatment we used Electric cell-substrate impedance sensing (ECIS) to monitor cell growth and migration and MTS assays to study viability after irradiation and temozolomide treatment. Finally, we quantitated NSE expression in a series of human glioma biopsies with immunohistochemistry using a morphometry software, and collected survival data for the corresponding patients. The biopsies were then grouped according to expression in two halves which were compared by survival analysis.

Results

Immunocytochemistry and Western blotting showed that all markers except NFP were expressed both in GBM cell lines and biopsies. Notably, qPCR demonstrated that NSE was upregulated in cellular stress conditions, such as serum-starvation and hypoxia, while we found no uniform pattern for the other markers. NSE knockdown reduced the migration of glioma cells, sensitized them to hypoxia, radio- and chemotherapy. Furthermore, we found that GBM patients in the group with the highest NSE expression lived significantly shorter than patients in the low-expression group.

Conclusions

Neuronal markers are aberrantly expressed in human GBMs, and NSE is consistently upregulated in different cellular stress conditions. Knockdown of NSE reduces the migration of GBM cells and sensitizes them to hypoxia, radiotherapy and chemotherapy. In addition, GBM patients with high NSE expression had significantly shorter survival than patients with low NSE expression. Collectively, these data suggest a role for NSE in the adaption to cellular stress, such as during treatment.
In situgastrointestinal protection against anthrax edema toxin by single-chain antibody fragment producing lactobacilli
Authors: Andersen Kasper Krogh , Marcotte Harold , Álvarez Beatriz , Boyaka Prosper N , Hammarström Lennart
Published: December 2011

Background

Anthrax is caused by the bacterium Bacillus anthracis and is regarded as one of the most prominent bioterrorism threats. Anthrax toxicity is induced by the tripartite toxin complex, composed of the receptor-binding anthrax protective antigen and the two enzymatic subunits, lethal factor and edema factor. Recombinant lactobacilli have previously been used to deliver antibody fragments directed against surface epitopes of a variety of pathogens, including Streptococcus mutans, Porphyromonas gingivalis, and rotavirus. Here, we addressed whether or not anthrax toxins could be targeted and neutralised in the gastrointestinal tract by lactobacilli producing recombinant antibody fragments as a model system for toxin neutralisation in the gastrointestinal lumen.

Results

The neutralising anti-PA scFv, 1H, was expressed in L. paracasei as a secreted protein, a cell wall-anchored protein or both secreted and wall-anchored protein. Cell wall display on lactobacilli and PA binding of the anchored constructs was confirmed by flow cytometry analysis. Binding of secreted or attached scFv produced by lactobacilli to PA were verified by ELISA. Both construct were able to protect macrophages in an in vitro cytotoxicity assay. Finally, lactobacilli producing the cell wall attached scFv were able to neutralise the activity of anthrax edema toxin in the GI tract of mice, in vivo.

Conclusion

We have developed lactobacilli expressing a neutralising scFv fragment against the PA antigen of the anthrax toxin, which can provide protection against anthrax toxins both in vitro and in vivo. Utilising engineered lactobacilli therapeutically for neutralising toxins in the gastrointestinal tract can potential be expanded to provide protection against a range of additional gastrointestinal pathogens. The ability of lactobacilli to colonise the gastrointestinal tract may allow the system to be used both prophylactically and therapeutically.
The O-mannosylation and production of recombinant APA (45/47 KDa) protein from Mycobacterium tuberculosis in Streptomyces lividans is affected by culture conditions in shake flasks
Authors: Gamboa-Suasnavart Ramsés A , Valdez-Cruz Norma A , Cordova-Dávalos Laura E , Martínez-Sotelo José A , Servín-González Luis , Espitia Clara , Trujillo-Roldán Mauricio A
Published: December 2011

Background

The Ala-Pro-rich O-glycoprotein known as the 45/47 kDa or APA antigen from Mycobacterium tuberculosis is an immunodominant adhesin restricted to mycobacterium genus and has been proposed as an alternative candidate to generate a new vaccine against tuberculosis or for diagnosis kits. In this work, the recombinant O-glycoprotein APA was produced by the non-pathogenic filamentous bacteria Streptomyces lividans, evaluating three different culture conditions. This strain is known for its ability to produce heterologous proteins in a shorter time compared to M. tuberculosis.

Results

Three different shake flask geometries were used to provide different shear and oxygenation conditions; and the impact of those conditions on the morphology of S. lividans and the production of rAPA was characterized and evaluated. Small unbranched free filaments and mycelial clumps were found in baffled and coiled shake flasks, but one order of magnitude larger pellets were found in conventional shake flasks. The production of rAPA is around 3 times higher in small mycelia than in larger pellets, most probably due to difficulties in mass transfer inside pellets. Moreover, there are four putative sites of O-mannosylation in native APA, one of which is located at the carboxy-terminal region. The carbohydrate composition of this site was determined for rAPA by mass spectrometry analysis, and was found to contain different glycoforms depending on culture conditions. Up to two mannoses residues were found in cultures carried out in conventional shake flasks, and up to five mannoses residues were determined in coiled and baffled shake flasks.

Conclusions

The shear and/or oxygenation parameters determine the bacterial morphology, the productivity, and the O-mannosylation of rAPA in S. lividans. As demonstrated here, culture conditions have to be carefully controlled in order to obtain recombinant O-glycosylated proteins with similar "quality" in bacteria, particularly, if the protein activity depends on the glycosylation pattern. Furthermore, it will be an interesting exercise to determine the effect of shear and oxygen in shake flasks, to obtain evidences that may be useful in scaling-up these processes to bioreactors. Another approach will be using lab-scale bioreactors under well-controlled conditions, and study the impact of those on rAPA productivity and quality.
Efficient Blockade of Akt signaling is a determinant factor to overcome resistance to Matuzumab
Authors: Meira Debora D , Almeida Vitor H , Mororó Jânio S , Caetano Mauricio S , Nóbrega Isabel P , Batista Delano , Sternberg Cinthya , Ferreira Carlos G
Published: December 2011

Background

Clinical studies have shown antineoplastic effectiveness of monoclonal antibodies (MAbs) against EGFR for different indications. Several MAbs directed to EGFR were developed recently, such as matuzumab, but there is still lack of information on preclinical data on its combination with chemo-radiation. Thus, the present study intended to examine the molecular pathways triggered by matuzumab alone or associated to chemo-radiotherapy in gynecological cell lines and its impact on cell growth and signaling.

Results

Combination of matuzumab with radiation and cisplatin did not enhance its cytostatic effects on A431, Caski and C33A cells (high, intermediate and low EGFR expression, respectively) in clonogenic assays, when compared to controls. The lack of effect was mediated by persistent signaling through EGFR due to its impaired degradation. In spite of the fact that matuzumab inhibited phosphorylation of EGFR, it had no effect upon cell viability. To analyze which downstream molecules would be involved in the EGFR signaling in the presence of matuzumab, we have tested it in combination with either PD98059 (MAPK inhibitor), or LY294002 (PI3K inhibitor). Matuzumab exhibited a synergic effect with LY294002, leading to a reduction of Akt phosphorylation that was followed by a decrease in A431 and Caski cells survival. The combination of PD98059 and matuzumab did not show the same effect suggesting that PI3K is an important effector of EGFR signaling in matuzumab-treated cells. Nonetheless, matuzumab induced ADCC in Caski cells, but not in the C33A cell line, suggesting that its potential therapeutic effects in vitro are indeed dependent on EGFR expression.

Conclusions

Matuzumab combined with chemoradiation did not induce cytotoxic effects on gynecological cancer cell lines in vitro, most likely due to impaired EGFR degradation. However, a combination of matuzumab and PI3K inhibitor synergistically inhibited pAkt and cell survival, suggesting that the use of PI3K/Akt inhibitors could overcome intrinsic resistance to matuzumab in vitro. Altogether, data presented here can pave the way to a rational design of clinical strategies in patients with resistant profile to anti-EGFR inhibitors based on combination therapy.
The Relationship between Brown Adipose Tissue Activity and Neoplastic Status: an 18F-FDG PET/CT Study in the Tropics
Authors: Huang Yung-Cheng , Chen Tai-Been , Hsu Chien-Chin , Li Shau-Hsuan , Wang Pei-Wen , Lee Bi-Fang , Kuo Ching-Yuan , Chiu Nan-Tsing
Published: December 2011

Background

Brown adipose tissue (BAT) has thermogenic potential. For its activation, cold exposure is considered a critical factor though other determinants have also been reported. The purpose of this study was to assess the relationship between neoplastic status and BAT activity by 2-deoxy-2-[18F]fluoro-D-glucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) in people living in the tropics, where the influence of outdoor temperature was low.

Methods

18F-FDG PET/CT scans were reviewed and the total metabolic activity (TMA) of identified activated BAT quantified. The distribution and TMA of activated BAT were compared between patients with and without a cancer history. The neoplastic status of patients was scored according to their cancer history and 18F-FDG PET/CT findings. We evaluated the relationships between the TMA of BAT and neoplastic status along with other factors: age, body mass index, fasting blood sugar, gender, and outdoor temperature.

Results

Thirty of 1740 patients had activated BAT. Those with a cancer history had wider BAT distribution (p = 0.043) and a higher TMA (p = 0.028) than those without. A higher neoplastic status score was associated with a higher average TMA. Multivariate analyses showed that neoplastic status was the only factor significantly associated with the TMA of activated BAT (p = 0.016).

Conclusions

Neoplastic status is a critical determinant of BAT activity in patients living in the tropics. More active neoplastic status was associated with more vigorous TMA of BAT.
A Novel Approach to Standard Techniques in the Assessment and Quantification of the Interventricular Systolic Relationship
Authors: Bruhl Steven R , Chahal Mangeet , Khouri Samer J
Published: December 2011

Background

Blood flow between the right and left ventricles is subject to the continuity equation and systolic ventricular interdependence. Quantification of this relationship might aid in understanding inter-ventricular function. The purpose of this study was to evaluate and quantify ventricular interdependence by directly comparing right and left ventricular systolic function though echocardiographic surrogates of right and left ventricular systolic function such as MAPSE, TAPSE, RV TVI and LV TVI.

Methods

This study prospectively evaluated 51 healthy participants (mean age, 41 ± 17 years) by resting echocardiography. In addition to standard measurements, tricuspid annular plane of systolic excursion, (TAPSE), mitral annular plane of systolic excursion (MAPSE), and the peak annulus systolic velocity of the right ventricular (RVs) and left ventricular (LVs) free walls were measured by M-mode and pulsed wave Doppler tissue echocardiography and further evaluated for variance across age, gender, and body surface area.

Results

TAPSE (22.1 ± 2.9 mm) was over 54.5% greater than MAPSE (14.3 ± 2.6 mm) and RVs was 64.4% greater than LVs. The LV to RV systolic relationship measured by MAPSE/TAPSE and LVs/RVs ratios were 0.66 ± 0.14 and 0.76 ± 0.21 respectively. These values were not significantly affected by age, gender or body surface area (BSA).

Conclusion

MAPSE/TAPSE and LVs/RVs ratios appear stable across age, gender, and BSA potentially making them good surrogates of systolic ventricular relationship and interdependence.
Determinants of quality of life in adults with type 1 and type 2 diabetes
Authors: Imayama Ikuyo , Plotnikoff Ronald C , Courneya Kerry S , Johnson Jeffrey A
Published: December 2011

Background

Limited evidence exists on the determinants of quality of life (QoL) specific to adults with type 1 diabetes (T1D). Further, it appears no study has compared the determinants of QoL between T1D and type 2 diabetes (T2D) groups. The objectives of this study were to examine: (1) determinants of QoL in adults with T1D; and, (2) differences in QoL determinants between T1D and T2D groups.

Methods

The Alberta Longitudinal Exercise and Diabetes Research Advancement (ALEXANDRA) study, a longitudinal study of adults with diabetes in Alberta, Canada. Adults (18 years and older) with T1D (N = 490) and T2D (N = 1,147) provided information on demographics (gender, marital status, education, and annual income), personality (activity trait), medical factors (diabetes duration, insulin use, number of comorbidities, and body mass index), lifestyle behaviors (smoking habits, physical activity, and diet), health-related quality of life (HRQL) and life satisfaction. Multiple regression models identified determinants of HRQL and life satisfaction in adults with T1D. These determinants were compared with determinants for T2D adults reported in a previous study from this population data set. Factors significantly associated with HRQL and life satisfaction in either T1D or T2D groups were further tested for interaction with diabetes type.

Results

In adults with T1D, higher activity trait (personality) score (β = 0.28, p < 0.01), fewer comorbidities (β = - 0.27, p < 0.01), lower body mass index (BMI)(β = - 0.12, p < 0.01), being a non-smoker (β = - 0.14, p < 0.01), and higher physical activity levels (β = 0.16, p < 0.01) were associated with higher HRQL. Having a partner (β = 0.11, p < 0.05), high annual income (β = 0.16, p < 0.01), and high activity trait (personality) score (β = 0.27, p < 0.01) were significantly associated with higher life satisfaction. There was a significant age × diabetes type interaction for HRQL. The T2D group had a stronger positive relationship between advancing age and HRQL compared to the T1D group. No interaction was significant for life satisfaction.

Conclusions

Health services should target medical and lifestyle factors and provide support for T1D adults to increase their QoL. Additional social support for socioeconomically disadvantaged individuals living with this disease may be warranted. Health practitioners should also be aware that age has different effects on QoL between T1D and T2D adults.
An SNR-based admission control scheme in WiFi-based vehicular networks
Authors: Kim Kihun , Kim Younghyun , Pack Sangheon , Choi Nakjung
Published: December 2011

In WiFi-based vehicular networks, the performance anomaly problem can be serious because different vehicles with diverse channel conditions access the channel by a random access protocol. In this article, we first develop a novel analytical model, which combines the vehicular traffic theory and WiFi properties to show the impact of performance anomaly at the intersection. We then propose a signal-to-noise ratio (SNR)-based admission control scheme that excludes vehicles with bad channel qualities to address the performance anomaly problem. Extensive simulation and analytical results are presented to show the effect of the traffic condition and the topology. From the simulation results, it can be found that the SNR-based admission control scheme can improve the overall throughput, and starvation issues can be addressed by means of mobility in WiFi-based vehicular networks with multiple intersections.
Hierarchical convergence of an implicit double-net algorithm for nonexpansive semigroups and variational inequality problems
Authors: Yao Yonghong , Je Cho Yeol , Liou Yeong-Cheng
Published: December 2011

In this paper, we show the hierarchical convergence of the following implicit double-net algorithm:

x

s
,
t

=
s

[

t
f

(

x

s
,
t

)

+

(

1
-
t

)

(

x

s
,
t

-
μ
A

x

s
,
t

)

]

+

(

1
-
s

)

1

λ

s

∫

0

λ

s

T

(

v

)

x

s
,
t

d
ν
,

∀
s
,
t
∈

(

0
,
1

)

,

where f is a ρ-contraction on a real Hilbert space H, A : H → H is an α-inverse strongly monotone mapping and S = {T(s)}s ≥ 0: H → H is a nonexpansive semi-group with the common fixed points set Fix(S) ≠ ∅, where Fix(S) denotes the set of fixed points of the mapping S, and, for each fixed t ∈ (0, 1), the net {x
s, t
} converges in norm as s → 0 to a common fixed point x
t
∈ Fix(S) of {T(s)}s ≥ 0and, as t → 0, the net {x
t
} converges in norm to the solution x* of the following variational inequality:

x

*

∈
F
i
x

(

S

)

;

〈

A

x

*

,

x
-

x

*

〉

≥
0
,

∀
x
∈
F
i
x

(

S

)

.

MSC(2000): 49J40; 47J20; 47H09; 65J15.
Learning in a simple biological system: a pilot study of classical conditioning of human macrophages in vitro
Authors: Nilsonne Gustav , Appelgren Alva , Axelsson John , Fredrikson Mats , Lekander Mats
Published: December 2011

Recent advances in cell biology and gene regulation suggest mechanisms whereby associative learning could be performed by single cells. Therefore, we explored a model of classical conditioning in human macrophages in vitro. In macrophage cultures, bacterial lipopolysaccharide (LPS; unconditioned stimulus) was paired once with streptomycin (conditioned stimulus). Secretion of interleukin-6 (IL-6) was used as response measure. At evocation, conditioning was not observed. Levels of IL-6 were higher only in those cultures that had been exposed to LPS in the learning phase (p's < .05), regardless whether they received the conditioned stimulus or not at evocation.

However, habituation was evident, with a 62% loss of the IL-6 response after three LPS presentations (p < .001). If further experiments confirm that simple learning can occur in immune cells, this may have bearings not only on immune regulation, but also on the brain response to molecular signals detected in the periphery. Importantly, whether capacities for simple learning in single cells extend beyond habituation, and how this would be demonstrated, remain open questions.
Extraosseous (extramedullary) plasmacytomas: a clinicopathologic and immunophenotypic study of 32 Chinese cases
Authors: Zuo Zhuo , Tang Yuan , Bi Cheng-Feng , Zhang Wen-Yan , Zhao Sha , Wang Xiao-Qing , Yang Qun-Pei , Zou Li-Qun , Liu Wei-Ping
Published: December 2011

Background

Extraosseous plasmacytoma, so called extramedullary plasmacytoma (EMP) is relatively rare in China. The aim was investigate the clinicopathologic features of EMP and the role of Immunophenotype and genotype detection in diagnosis of EMP.

Methods

Thirty-two cases of EMP were investigated retrospectively by histopathology, immunophenotype, genotype and survival analysis.

Results

Clinically, the mean age of the patients was 53.4. Most of the patients received no treatment after the diagnosis was established, and the prognosis was relatively poor. Histologically, in 40% of the cases, the neoplastic cells were grade II or III. The neoplastic cells expressed one or more PC associated antigens. The immunophenotype of EMP and inflammation of sinonasal regions with numerous PC infiltrations were compared and showed some difference in expression of CD45, CD27, CD44v6 and Bcl-2 as well. Ig light chain restriction was detected in 87.5% of the cases.

Conclusions

we described 32 Chinese cases of EMP, compare with that reported in the literature, some differences are presented, including higher percentage of grade II and III cases, clinically inconsistent treatment and management as well as poor outcome of the disease.
Reverse protection assay: a tool to analyze transcriptional rates from individual promoters
Authors: Zubo Yan O , Kusnetsov Victor V , Börner Thomas , Liere Karsten
Published: December 2011

Transcriptional activity of entire genes in chloroplasts is usually assayed by run-on analyses. To determine not only the overall intensity of transcription of a gene, but also the rate of transcription from a particular promoter, we created the Reverse RNase Protection Assay (RePro): in-organello run-on transcription coupled to RNase protection to define distinct transcript ends during transcription. We demonstrate successful application of RePro in plastid promoter analysis and transcript 3' end processing.
The Scandinavian multicenter hemodynamic evaluation of the SJM Regent aortic valve
Authors: Offstad Jon , Andersen Kai , Paulsson Per , Andreasson Jesper , Kjellman Ulf , Lundblad Oluf , Engstrøm Karl Gunnar , Haaverstad Rune , Svennevig Jan L
Published: December 2011

Background

112 patients who received small and medium sized St.Jude Regent heart valves (19-25 mm) at 7 Scandinavian centers were studied between January 2003 and February 2005 to obtain non-invasive data regarding the hemodynamic performance at rest and during Dobutamine stress echocardiography (DSE) testing one year after surgery.

Material and methods

46 woman and 66 men, aged 61.8 ± 9.7 (18-75) years, were operated on for aortic regurgitation (17), stenosis (65), or mixed dysfunction (30). Valve sizes were 19 mm (6), 21 mm (33), 23 mm (41), 25 mm (30). Two patients receiving size 27 valves were excluded from the hemodynamic evaluation. Pledgets were used in 100 patients, everted mattress in 66 and simple interrupted sutures in 21. Valve orientation varied and was dependent on the surgeons' choice. 34 patients (30.4%) underwent concomitant coronary artery surgery.

Results

There were two early deaths (1.8%) and three late deaths, one because of pancreatic cancer. Late events during follow-up were: non structural dysfunction (1), bleeding (2), thromboembolism (2). At one year follow up 93% of the patients were in NYHA classes 1-2 versus 47.8% preoperatively.

Dobutamine stress echocardiography (DSE) was performed in a total of 66 and maximal peak stress was reached in 61 patients.

During DSE testing, the following statistically significant changes took place: Heart rate increased by 73.0%, cardiac output by 85.5%, left ventriclular ejection fraction by 19.6%, and maximal mean prosthetic transvalvular gradient by 133.8%, whereas the effective orifice area index did not change.

Left ventricular mass fell during one year from 215 ± 63 to 197 ± 62 g (p < 0.05).

Conclusion

The Dobutamine test induces a substantial stress, well suitable for echocardiographic assessment of prosthesis valve function and can be performed in the majority of the patients. The changes in pressure gradients add to the hemodynamic characteristics of the various valve sizes.

In our patients the St. Jude Regent valve performed satisfactory at rest and under pharmacological stress situation.
Microglial p38α MAPK is critical for LPS-induced neuron degeneration, through a mechanism involving TNFα
Authors: Xing Bin , Bachstetter Adam D , Van Eldik Linda J
Published: December 2011

Background

The p38α MAPK isoform is a well-established therapeutic target in peripheral inflammatory diseases, but the importance of this kinase in pathological microglial activation and detrimental inflammation in CNS disorders is less well understood. To test the role of the p38α MAPK isoform in microglia-dependent neuron damage, we used primary microglia from wild-type (WT) or p38α MAPK conditional knockout (KO) mice in co-culture with WT cortical neurons, and measured neuron damage after LPS insult.

Results

We found that neurons in co-culture with p38α-deficient microglia were protected against LPS-induced synaptic loss, neurite degeneration, and neuronal death. The involvement of the proinflammatory cytokine TNFα was demonstrated by the findings that p38α KO microglia produced much less TNFα in response to LPS compared to WT microglia, that adding back TNFα to KO microglia/neuron co-cultures increased the LPS-induced neuron damage, and that neutralization of TNFα in WT microglia/neuron co-cultures prevented the neuron damage. These results using cell-selective, isoform-specific KO mice demonstrate that the p38α MAPK isoform in microglia is a key mediator of LPS-induced neuronal and synaptic dysfunction. The findings also provide evidence that a major mechanism by which LPS activation of microglia p38α MAPK signaling leads to neuron damage is through up-regulation of the proinflammatory cytokine TNFα.

Conclusions

The data suggest that selective targeting of p38α MAPK signaling should be explored as a potential therapeutic strategy for CNS disorders where overproduction of proinflammatory cytokines is implicated in disease progression.