bluuebunny/crossref_metadata_2025 huggingface dataset:
A community effort towards a knowledge-base and mathematical model of the human pathogen Salmonella Typhimurium LT2
Authors: Thiele Ines , Hyduke Daniel R , Steeb Benjamin , Fankam Guy , Allen Douglas K , Bazzani Susanna , Charusanti Pep , Chen Feng-Chi , Fleming Ronan MT , Hsiung Chao A , De Keersmaecker Sigrid CJ , Liao Yu-Chieh , Marchal Kathleen , Mo Monica L , Özdemir Emre , Raghunathan Anu , Reed Jennifer L , Shin Sook-Il , Sigurbjörnsdóttir Sara , Steinmann Jonas , Sudarsan Suresh , Swainston Neil , Thijs Inge M , Zengler Karsten , Palsson Bernhard O , Adkins Joshua N , Bumann Dirk
Published: February 2011

Background

Metabolic reconstructions (MRs) are common denominators in systems biology and represent biochemical, genetic, and genomic (BiGG) knowledge-bases for target organisms by capturing currently available information in a consistent, structured manner. Salmonella enterica subspecies I serovar Typhimurium is a human pathogen, causes various diseases and its increasing antibiotic resistance poses a public health problem.

Results

Here, we describe a community-driven effort, in which more than 20 experts in S. Typhimurium biology and systems biology collaborated to reconcile and expand the S. Typhimurium BiGG knowledge-base. The consensus MR was obtained starting from two independently developed MRs for S. Typhimurium. Key results of this reconstruction jamboree include i) development and implementation of a community-based workflow for MR annotation and reconciliation; ii) incorporation of thermodynamic information; and iii) use of the consensus MR to identify potential multi-target drug therapy approaches.

Conclusion

Taken together, with the growing number of parallel MRs a structured, community-driven approach will be necessary to maximize quality while increasing adoption of MRs in experimental design and interpretation.
Gastric cancers of Western European and African patients show different patterns of genomic instability
Authors: Buffart Tineke E , Louw Melanie , van Grieken Nicole CT , Tijssen Marianne , Carvalho Beatriz , Ylstra Bauke , Grabsch Heike , Mulder Chris JJ , van de Velde Cornelis JH , van der Merwe Schalk W , Meijer Gerrit A
Published: February 2011

Background

Infection with H. pylori is important in the etiology of gastric cancer. Gastric cancer is infrequent in Africa, despite high frequencies of H. pylori infection, referred to as the African enigma. Variation in environmental and host factors influencing gastric cancer risk between different populations have been reported but little is known about the biological differences between gastric cancers from different geographic locations. We aim to study genomic instability patterns of gastric cancers obtained from patients from United Kingdom (UK) and South Africa (SA), in an attempt to support the African enigma hypothesis at the biological level.

Methods

DNA was isolated from 67 gastric adenocarcinomas, 33 UK patients, 9 Caucasian SA patients and 25 native SA patients. Microsatellite instability and chromosomal instability were analyzed by PCR and microarray comparative genomic hybridization, respectively. Data was analyzed by supervised univariate and multivariate analyses as well as unsupervised hierarchical cluster analysis.

Results

Tumors from Caucasian and native SA patients showed significantly more microsatellite instable tumors (p < 0.05). For the microsatellite stable tumors, geographical origin of the patients correlated with cluster membership, derived from unsupervised hierarchical cluster analysis (p = 0.001). Several chromosomal alterations showed significantly different frequencies in tumors from UK patients and native SA patients, but not between UK and Caucasian SA patients and between native and Caucasian SA patients.

Conclusions

Gastric cancers from SA and UK patients show differences in genetic instability patterns, indicating possible different biological mechanisms in patients from different geographical origin. This is of future clinical relevance for stratification of gastric cancer therapy.
The role of proboscis of the malaria vector mosquito Anopheles stephensi in host-seeking behavior
Authors: Maekawa Emi , Aonuma Hiroka , Nelson Bryce , Yoshimura Aya , Tokunaga Fumio , Fukumoto Shinya , Kanuka Hirotaka
Published: February 2011

Background

The proboscis is an essential head appendage in insects that processes gustatory code during food intake, particularly useful considering that blood-sucking arthropods routinely reach vessels under the host skin using this proboscis as a probe.

Results

Here, using an automated device able to quantify CO2-activated thermo (35°C)-sensing behavior of the malaria vector Anopheles stephensi, we uncovered that the protruding proboscis of mosquitoes contributes unexpectedly to host identification from a distance. Ablation experiments indicated that not only antennae and maxillary palps, but also proboscis were required for the identification of pseudo-thermo targets. Furthermore, the function of the proboscis during this behavior can be segregated from CO2 detection required to evoke mosquito activation, suggesting that the proboscis of mosquitoes divide the proboscis into a "thermo-antenna" in addition to a "thermo-probe".

Conclusions

Our findings support an emerging view with a possible role of proboscis as important equipment during host-seeking, and give us an insight into how these appendages likely evolved from a common origin in order to function as antenna organs.
The modulation of TRPM7 currents by nafamostat mesilate depends directly upon extracellular concentrations of divalent cations
Authors: Chen Xuanmao , Numata Tomohiro , Li Minghua , Mori Yasuo , Orser Beverley A , Jackson Michael F , Xiong Zhi-Gang , MacDonald John F
Published: February 2011

Concentrations of extracellular divalent cations (Ca2+ and Mg2+) fall substantially during intensive synaptic transmission as well as during some pathophysiological conditions such as epilepsy and brain ischemia. Here we report that a synthetic serine protease inhibitor, nafamostat mesylate (NM), and several of its analogues, block recombinant TRPM7 currents expressed in HEK293T cells in inverse relationship to the concentration of extracellular divalent cations. Lowering extracellular Ca2+ and Mg2+ also evokes a divalent-sensitive non-selective cation current that is mediated by TRPM7 expression in hippocampal neurons. In cultured hippocampal neurons, NM blocked these TRPM7-mediated currents with an apparent affinity of 27 μM, as well as the paradoxical Ca2+ influx associated with lowering extracellular Ca2+. Unexpectedly, pre-exposure to NM strongly potentiated TRPM7 currents. In the presence of physiological concentrations of extracellular divalent cations, NM activates TRPM7. The stimulating effects of NM on TRPM7 currents are also inversely related to extracellular Ca2+ and Mg2+. DAPI and HSB but not netropsin, blocked and stimulated TRPM7. In contrast, mono-cationic, the metabolites of NM, p-GBA and AN, as well as protease inhibitor leupeptin and gabexate failed to substantially modulate TRPM7. NM thus provides a molecular template for the design of putative modulators of TRPM7.
Properties of Contextual Memory Formed in the Absence of αCaMKII Autophosphorylation
Authors: Irvine Elaine E , Danhiez Arthur , Radwanska Kasia , Nassim Charlotte , Lucchesi Walter , Godaux Emile , Ris Laurence , Giese K Peter
Published: February 2011

The alpha-isoform of calcium/calmodulin-dependent kinase II (αCaMKII) is a major synaptic kinase that undergoes autophosphorylation after NMDA receptor activation, switching the kinase into a calcium-independent activity state. This αCaMKII autophosphorylation is essential for NMDA receptor-dependent long-term potentiation (LTP), induced by a single tetanus, in hippocampal area CA1 and in neocortex. Furthermore, the αCaMKII autophosphorylation is essential for contextual long-term memory (LTM) formation after a single training trial but not after a massed training session. Here, we show that in the absence of αCaMKII autophosphorylation contextual fear conditioning is hippocampus dependent and that multi-tetanus-dependent late-LTP cannot be induced in hippocampal area CA1. Furthermore, we show that in the absence of αCaMKII autophosphorylation contextual LTM persists for 30 days, the latest time point tested. Additionally, contextual, but not cued, LTM formation in the absence of αCaMKII autophosphorylation appears to be impaired in 18 month-old mice. Taken together, our findings suggest that αCaMKII autophosphorylation-independent plasticity in the hippocampus is sufficient for contextual LTM formation and that αCaMKII autophosphorylation may be important for delaying age-related impairments in hippocampal memory formation. Furthermore, they propose that NMDA receptor-dependent LTP in hippocampal area CA1 is essential for contextual LTM formation after a single trial but not after massed training. Finally, our results challenge the proposal that NMDA receptor-dependent LTP in neocortex is required for remote contextual LTM.
Two-dose-level confirmatory study of the pharmacokinetics and tolerability of everolimus in Chinese patients with advanced solid tumors
Authors: Xu BingHe , Wu YiLong , Shen Lin , Ye DingWei , Jappe Annette , Cherfi Azzeddine , Wang Hui , Yuan RuiRong
Published: February 2011

Background

This phase I, randomized, multicenter, open-label study investigated the pharmacokinetics, safety, and efficacy of the oral mammalian target of rapamycin inhibitor everolimus in Chinese patients with advanced solid tumors.

Methods

A total of 24 patients with advanced breast cancer (n = 6), gastric cancer (n = 6), non-small cell lung cancer (n = 6), or renal cell carcinoma (n = 6) who were refractory to/unsuitable for standard therapy were randomized 1:1 to oral everolimus 5 or 10 mg/day. Primary end points were pharmacokinetic parameters and safety and tolerability. Pharmacokinetic 24-h profiles were measured on day 15; trough level was measured on days 2, 8, 15, 16, and 22. Tolerability was assessed continuously. This final analysis was performed after all patients had received 6 months of study drug or had discontinued.

Results

Everolimus was absorbed rapidly; median Tmax was 3 h (range, 1-4) and 2 h (range, 0.9-6) in the 5 and 10 mg/day groups, respectively. Pharmacokinetic parameters increased dose proportionally from the 5 and 10 mg/day doses. Steady-state levels were achieved by day 8 or earlier. The most common adverse events suspected to be related to everolimus therapy were increased blood glucose (16.7% and 41.7%) and fatigue (16.7% and 33.3%) in the everolimus 5 and 10 mg/day dose cohorts, respectively. Best tumor response was stable disease in 10 (83%) and 6 (50%) patients in the 5 and 10 mg/day groups, respectively.

Conclusions

Everolimus 5 or 10 mg/day was well tolerated in Chinese patients with advanced solid tumors. The observed safety and pharmacokinetic profile of everolimus from this study were consistent with previous studies.

Trial registration

Chinese Health Authorities 2008L09346
Bostrycin inhibits proliferation of human lung carcinoma A549 cells via downregulation of the PI3K/Akt pathway
Authors: Chen Wei-Sheng , Hou Jun-Na , Guo Yu-Biao , Yang Hui-Ling , Xie Can-Mao , Lin Yong-Cheng , She Zhi-Gang
Published: February 2011

Background

Bostrycin is a novel compound isolated from marine fungi that inhibits proliferation of many cancer cells. However, the inhibitory effect of bostrycin on lung cancers has not been reported. This study is to investigate the inhibitory effects and mechanism of bostrycin on human lung cancer cells in vitro.

Methods

We used MTT assay, flow cytometry, microarray, real time PCR, and Western blotting to detect the effect of bostrycin on A549 human pulmonary adenocarcinoma cells.

Results

We showed a significant inhibition of cell proliferation and induction of apoptosis in bostrycin-treated lung adenocarcinoma cells. Bostrycin treatment caused cell cycle arrest in the G0/G1 phase. We also found the upregulation of microRNA-638 and microRNA-923 in bostrycin-treated cells. further, we found the downregulation of p110α and p-Akt/PKB proteins and increased activity of p27 protein after bostrycin treatment in A549 cells.

Conclusions

Our study indicated that bostrycin had a significant inhibitory effect on proliferation of A549 cells. It is possible that upregulation of microRNA-638 and microRNA-923 and downregulaton of the PI3K/AKT pathway proteins played a role in induction of cell cycle arrest and apoptosis in bostrycin-treated cells.
Changes in joint coupling and variability during walking following tibialis posterior muscle fatigue
Authors: Ferber Reed , Pohl Michael B
Published: February 2011

Background

The tibialis posterior muscle is believed to play a key role in controlling foot mechanics during the stance phase of gait. However, an experiment involving localised tibialis posterior muscle fatigue, and analysis of discrete rearfoot and forefoot kinematic variables, indicated that reduced force output of the tibialis posterior muscle did not alter rearfoot and forefoot motion during gait. Thus, to better understand how muscle fatigue affects foot kinematics and injury potential, the purpose of this study was to reanalyze the data and investigate shank, rearfoot and forefoot joint coupling and coupling variability during walking.

Methods

Twenty‐nine participants underwent an exercise fatigue protocol aimed at reducing the force output of tibialis posterior. An eight camera motion analysis system was used to evaluate 3 D shank and foot joint coupling and coupling variability during treadmill walking both pre‐ and post‐fatigue.

Results

The fatigue protocol was successful in reducing the maximal isometric force by over 30% and a concomitant increase in coupling motion of the shank in the transverse plane and forefoot in the sagittal and transverse planes relative to frontal plane motion of the rearfoot. In addition, an increase in joint coupling variability was measured between the shank and rearfoot and between the rearfoot and forefoot during the fatigue condition.

Conclusions

The reduced function of the tibialis posterior muscle following fatigue resulted in a disruption in typical shank and foot joint coupling patterns and an increased variability in joint coupling. These results could help explain tibialis posterior injury aetiology.
At the frontiers of surgery: review
Authors: Upile Tahwinder , Jerjes Waseem K , Sterenborg Henricus J , Wong Brian J , El-Naggar Adel K , Ilgner Justus F , Sandison Ann , Witjes Max J , Biel Merrill A , van Veen Robert , Hamdoon Zaid , Gillenwater Ann , Mosse Charles A , Robinson Dominic J , Betz Christian S , Stepp Herbert , Bolotine Lina , McKenzie Gordon , Barr Hugh , Chen Zhongping , Berg Kristian , D'Cruz Anil K , Sudhoff Holger , Stone Nicholas , Kendall Catherine , Fisher Sheila , MacRobert Alexander J , Leunig Andreas , Olivo Malini , Richards-Kortum Rebecca , Soo Khee C , Bagnato Vanderlei , Choo-Smith Lin-Ping , Svanberg Katarina , Tan I Bing , Wilson Brian C , Wolfsen Herbert , Bigio Irving , Yodh Arjun G , Hopper Colin
Published: February 2011

The complete surgical removal of disease is a desirable outcome particularly in oncology. Unfortunately much disease is microscopic and difficult to detect causing a liability to recurrence and worsened overall prognosis with attendant costs in terms of morbidity and mortality. It is hoped that by advances in optical diagnostic technology we could better define our surgical margin and so increase the rate of truly negative margins on the one hand and on the other hand to take out only the necessary amount of tissue and leave more unaffected non-diseased areas so preserving function of vital structures. The task has not been easy but progress is being made as exemplified by the presentations at the 2nd Scientific Meeting of the Head and Neck Optical Diagnostics Society (HNODS) in San Francisco in January 2010. We review the salient advances in the field and propose further directions of investigation.
Statistical structure of lateral connections in the primary visual cortex
Authors: Hunt Jonathan J , Bosking William H , Goodhill Geoffrey J
Published: February 2011

Background

The statistical structure of the visual world offers many useful clues for understanding how biological visual systems may understand natural scenes. One particularly important early process in visual object recognition is that of grouping together edges which belong to the same contour. The layout of edges in natural scenes have strong statistical structure. One such statistical property is that edges tend to lie on a common circle, and this 'co-circularity' can predict human performance at contour grouping. We therefore tested the hypothesis that long-range excitatory lateral connections in the primary visual cortex, which are believed to be involved in contour grouping, display a similar co-circular structure.

Results

By analyzing data from tree shrews, where information on both lateral connectivity and the overall structure of the orientation map was available, we found a surprising diversity in the relevant statistical structure of the connections. In particular, the extent to which co-circularity was displayed varied significantly.

Conclusions

Overall, these data suggest the intriguing possibility that V1 may contain both co-circular and anti-cocircular connections.
Genetic visualization of the secondary olfactory pathway in Tbx21 transgenic mice
Authors: Mitsui Sachiko , Igarashi Kei M , Mori Kensaku , Yoshihara Yoshihiro
Published: February 2011

Background

Mitral and tufted cells are the projection neurons in the olfactory bulb, conveying odour information to various regions of the olfactory cortex. In spite of their functional importance, there are few molecular and genetic tools that can be used for selective labelling or manipulation of mitral and tufted cells. Tbx21 was first identified as a T-box family transcription factor regulating the differentiation and function of T lymphocytes. In the brain, Tbx21 is specifically expressed in mitral and tufted cells of the olfactory bulb.

Results

In this study, we performed a promoter/enhancer analysis of mouse Tbx21 gene by comparing nucleotide sequence similarity of Tbx21 genes among several mammalian species and generating transgenic mouse lines with various lengths of 5' upstream region fused to a fluorescent reporter gapVenus. We identified the cis-regulatory enhancer element (~300 nucleotides) at ~ 3.0 kb upstream of the transcription start site of Tbx21 gene, which is both necessary and sufficient for transgene expression in mitral and tufted cells. In contrast, the 2.6-kb 5'-flanking region of mouse Tbx21 gene induced transgene expression with variable patterns in restricted populations of neurons predominantly located along the olfactory pathway. Furthermore, we generated transgenic mice expressing the genetically-encoded fluorescent exocytosis indicator, synaptopHluorin, in mitral and tufted cells for visualization of presynaptic neural activities in the piriform cortex.

Conclusions

The transcriptional enhancer of Tbx21 gene provides a powerful tool for genetic manipulations of mitral and tufted cells in studying the development and function of the secondary olfactory pathways from the bulb to the cortex.
Dynamic development of the first synapse impinging on adult-born neurons in the olfactory bulb circuit
Authors: Katagiri Hiroyuki , Pallotto Marta , Nissant Antoine , Murray Kerren , Sassoè-Pognetto Marco , Lledo Pierre-Marie
Published: February 2011

The olfactory bulb (OB) receives and integrates newborn interneurons throughout life. This process is important for the proper functioning of the OB circuit and consequently, for the sense of smell. Although we know how these new interneurons are produced, the way in which they integrate into the pre-existing ongoing circuits remains poorly documented. Bearing in mind that glutamatergic inputs onto local OB interneurons are crucial for adjusting the level of bulbar inhibition, it is important to characterize when and how these inputs from excitatory synapses develop on newborn OB interneurons. We studied early synaptic events that lead to the formation and maturation of the first glutamatergic synapses on adult-born granule cells (GCs), the most abundant subtype of OB interneuron. Patch-clamp recordings and electron microscopy (EM) analysis were performed on adult-born interneurons shortly after their arrival in the adult OB circuits. We found that both the ratio of N-methyl-D-aspartate receptor (NMDAR) to α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR), and the number of functional release sites at proximal inputs reached a maximum during the critical period for the sensory-dependent survival of newborn cells, well before the completion of dendritic arborization. EM analysis showed an accompanying change in postsynaptic density shape during the same period of time. Interestingly, the latter morphological changes disappeared in more mature newly-formed neurons, when the NMDAR to AMPAR ratio had decreased and functional presynaptic terminals expressed only single release sites. Together, these findings show that the first glutamatergic inputs to adult-generated OB interneurons undergo a unique sequence of maturation stages.
IIb or not IIb? Regulation of myosin heavy chain gene expression in mice and men
Authors: Harrison Brooke C , Allen David L , Leinwand Leslie A
Published: February 2011

Background

While the myosin heavy chain IIb isoform (MyHC-IIb) is the predominant motor protein in most skeletal muscles of rats and mice, the messenger RNA (mRNA) for this isoform is only expressed in a very small subset of specialized muscles in adult large mammals, including humans.

Results

We identify the DNA sequences limiting MyHC-IIb expression in humans and explore the activation of this gene in human skeletal muscle. We demonstrate that the transcriptional activity of ~1.0 kb of the human MyHC-IIb promoter is greatly reduced compared to that of the corresponding mouse sequence in both mouse and human myotubes in vitro and show that nucleotide differences that eliminate binding sites for myocyte enhancer factor 2 (MEF2) and serum response factor (SRF) account for this difference. Despite these differences, we show that MyHC-IIb mRNA is expressed in fetal human muscle cells and that MyHC-IIb mRNA is significantly up-regulated in the skeletal muscle of Duchene muscular dystrophy patients.

Conclusions

These data identify the genetic basis for a key phenotypic difference between the muscles of large and small mammals, and demonstrate that mRNA expression of the MyHC-IIb gene can be re-activated in human limb muscle undergoing profound degeneration/regeneration.
Mannose-binding lectin does not explain the course and outcome of pregnancy in rheumatoid arthritis
Authors: van de Geijn Fleur E , de Man Yaël A , Wuhrer Manfred , Willemsen Sten P , Deelder André M , Hazes Johanna MW , Dolhain Radboud JEM
Published: February 2011

Introduction

Rheumatoid arthritis (RA) improves during pregnancy and flares after delivery. It has been hypothesized that high levels of the complement factor mannose-binding lectin (MBL) are associated with a favourable disease course of RA by facilitating the clearance of pathogenic immunoglobulin G (IgG) lacking galactose sugar moieties. During pregnancy, increased galactosylation of IgG and simultaneously increased MBL levels can be observed, with the latter being strictly related to maternal MBL genotypes. Therefore, increased MBL levels in concert with increased IgG galactosylation may be associated with pregnancy-induced improvement of RA. The objective of this study was to investigate whether MBL genotypes are associated with changes in RA disease activity and with changes in IgG galactosylation during pregnancy and in the postpartum period. We also studied the association between MBL genotypes and pregnancy outcomes in RA.

Methods

Serum from 216 patients with RA and 31 healthy controls participating in the Pregnancy-induced Amelioration of Rheumatoid Arthritis (PARA) Study was collected before, during and after pregnancy. IgG galactosylation was determined by performing matrix-assisted laser desorption/ionization time of flight mass spectrometry. Disease activity was determined using the internationally recognized Disease Activity Score 28 (DAS28). MBL genotypes were determined. The pregnancy outcome measures studied were gestational age, birth weight, miscarriage and hypertensive disorders.

Results

No association was found between the MBL genotype groups and changes in RA disease activity (P = 0.89) or changes in IgG galactosylation (patients, P = 0.75, and controls, P = 0.54) during pregnancy and in the postpartum period. Furthermore, MBL genotype groups were not related to the studied pregnancy outcome measures.

Conclusions

This study does not provide evidence for a role for MBL in the improvement of RA during pregnancy or for a role for MBL in pregnancy outcome.
A polymorphism in the interleukin-4 receptor affects the ability of interleukin-4 to regulate Th17 cells: a possible immunoregulatory mechanism for genetic control of the severity of rheumatoid arthritis
Authors: Wallis Susan K , Cooney Laura A , Endres Judith L , Lee Min Jie , Ryu Jennifer , Somers Emily C , Fox David A
Published: February 2011

Introduction

Rheumatoid arthritis (RA) is now suspected to be driven by pathogenic Th17 cells that secrete interleukin (IL)-17 and can be regulated by IL-4. A single-nucleotide polymorphism (SNP), I50V, in the coding region of the human IL-4 receptor (IL-4R) is associated with rapid development of erosive disease in RA. The present study was undertaken to determine whether this SNP renders the IL-4R less able to transduce signals that regulate IL-17 production.

Methods

Peripheral blood mononuclear cells were activated under Th17-stimulating conditions in the presence or absence of IL-4, and IL-17 production was measured by both enzyme-linked immunosorbent assay (ELISA) and flow cytometry. Serum IL-17 was also measured by ELISA. Paired comparisons were performed using the two-tailed t-test. IL-4 receptor gene alleles were determined by polymerase chain reaction.

Results

In healthy individuals, IL-4 significantly inhibited IL-17 production by cells from subjects with the I/I genotype (P = 0.0079) and the I/V genotype (P = 0.013), but not the V/V genotype (P > 0.05). In a cross-sectional sample of patients with established RA, the magnitude of the in vitro effect of IL-4 was lower and was not associated with a specific IL-4R allele. Serum IL-17 levels were higher in RA patients than in healthy individuals, as was the percentage of CD4+ cells that produced IL-17.

Conclusions

These results indicate that an inherited polymorphism of the IL-4R controls the ability of the human immune system to regulate the magnitude of IL-17 production. However, in established RA, this pattern may be altered, possibly due to secondary effects of both RA itself as well as immunomodulatory medications. Ineffective control of Th17 immune responses is a potential mechanism to explain why IL-4R is an important severity gene in RA, but this issue will require careful study of a cohort of new-onset RA patients.
Knockdown of miR-21 in human breast cancer cell lines inhibits proliferation, in vitro migration and in vivotumor growth
Authors: Yan Li Xu , Wu Qi Nian , Zhang Yan , Li Yang Yang , Liao Ding Zhun , Hou Jing Hui , Fu Jia , Zeng Mu Sheng , Yun Jing Ping , Wu Qiu Liang , Zeng Yi Xin , Shao Jian Yong
Published: February 2011

Introduction

MicroRNAs (miRNAs) are a class of small non-coding RNAs (20 to 24 nucleotides) that post-transcriptionally modulate gene expression. A key oncomir in carcinogenesis is miR-21, which is consistently up-regulated in a wide range of cancers. However, few functional studies are available for miR-21, and few targets have been identified. In this study, we explored the role of miR-21 in human breast cancer cells and tissues, and searched for miR-21 targets.

Methods

We used in vitro and in vivo assays to explore the role of miR-21 in the malignant progression of human breast cancer, using miR-21 knockdown. Using LNA silencing combined to microarray technology and target prediction, we screened for potential targets of miR-21 and validated direct targets by using luciferase reporter assay and Western blot. Two candidate target genes (EIF4A2 and ANKRD46) were selected for analysis of correlation with clinicopathological characteristics and prognosis using immunohistochemistry on cancer tissue microrrays.

Results

Anti-miR-21 inhibited growth and migration of MCF-7 and MDA-MB-231 cells in vitro, and tumor growth in nude mice. Knockdown of miR-21 significantly increased the expression of ANKRD46 at both mRNA and protein levels. Luciferase assays using a reporter carrying a putative target site in the 3' untranslated region of ANKRD46 revealed that miR-21 directly targeted ANKRD46. miR-21 and EIF4A2 protein were inversely expressed in breast cancers (rs = -0.283, P = 0.005, Spearman's correlation analysis).

Conclusions

Knockdown of miR-21 in MCF-7 and MDA-MB-231 cells inhibits in vitro and in vivo growth as well as in vitro migration. ANKRD46 is newly identified as a direct target of miR-21 in BC. These results suggest that inhibitory strategies against miR-21 using peptide nucleic acids (PNAs)-antimiR-21 may provide potential therapeutic applications in breast cancer treatment.
Tumor-specific HMG-CoA reductase expression in primary premenopausal breast cancer predicts response to tamoxifen
Authors: Brennan Donal J , Laursen Henriette , O'Connor Darran P , Borgquist Signe , Uhlen Mathias , Gallagher William M , Pontén Fredrik , Millikan Robert C , Rydén Lisa , Jirström Karin
Published: February 2011

Introduction

We previously reported an association between tumor-specific 3-hydroxy-3-methylglutharyl-coenzyme A reductase (HMG-CoAR) expression and a good prognosis in breast cancer. Here, the predictive value of HMG-CoAR expression in relation to tamoxifen response was examined.

Methods

HMG-CoAR protein and RNA expression was analyzed in a cell line model of tamoxifen resistance using western blotting and PCR. HMG-CoAR mRNA expression was examined in 155 tamoxifen-treated breast tumors obtained from a previously published gene expression study (Cohort I). HMG-CoAR protein expression was examined in 422 stage II premenopausal breast cancer patients, who had previously participated in a randomized control trial comparing 2 years of tamoxifen with no systemic adjuvant treatment (Cohort II). Kaplan-Meier analysis and Cox proportional hazards modeling were used to estimate the risk of recurrence-free survival (RFS) and the effect of HMG-CoAR expression on tamoxifen response.

Results

HMG-CoAR protein and RNA expression were decreased in tamoxifen-resistant MCF7-LCC9 cells compared with their tamoxifen-sensitive parental cell line. HMG-CoAR mRNA expression was decreased in tumors that recurred following tamoxifen treatment (P < 0.001) and was an independent predictor of RFS in Cohort I (hazard ratio = 0.63, P = 0.009). In Cohort II, adjuvant tamoxifen increased RFS in HMG-CoAR-positive tumors (P = 0.008). Multivariate Cox regression analysis demonstrated that HMG-CoAR was an independent predictor of improved RFS in Cohort II (hazard ratio = 0.67, P = 0.010), and subset analysis revealed that this was maintained in estrogen receptor (ER)-positive patients (hazard ratio = 0.65, P = 0.029). Multivariate interaction analysis demonstrated a difference in tamoxifen efficacy relative to HMG-CoAR expression (P = 0.05). Analysis of tamoxifen response revealed that patients with ER-positive/HMG-CoAR tumors had a significant response to tamoxifen (P = 0.010) as well as patients with ER-positive or HMG-CoAR-positive tumors (P = 0.035). Stratification according to ER and HMG-CoAR status demonstrated that ER-positive/HMG-CoAR-positive tumors had an improved RFS compared with ER-positive/HMG-CoAR-negative tumors in the treatment arm (P = 0.033); this effect was lost in the control arm (P = 0.138), however, suggesting that HMG-CoAR predicts tamoxifen response.

Conclusions

HMG-CoAR expression is a predictor of response to tamoxifen in both ER-positive and ER-negative disease. Premenopausal patients with tumors that express ER or HMG-CoAR respond to adjuvant tamoxifen.
Pathophysiological aspects of hyperglycemia in children with meningococcal sepsis and septic shock: a prospective, observational cohort study
Authors: Verhoeven Jennifer J , den Brinker Marieke , Hokken-Koelega Anita CS , Hazelzet Jan A , Joosten Koen FM
Published: February 2011

Introduction

The objective of this study was to investigate the occurrence of hyperglycemia and insulin response in critically ill children with meningococcal disease in the intensive care unit of an academic children's hospital.

Methods

Seventy-eight children with meningococcal disease were included. The group was classified into shock non-survivors, shock survivors and sepsis survivors. There were no sepsis-only non-survivors. The course of laboratory parameters during 48 hours was assessed. Insulin sensitivity and β-cell function on admission were investigated by relating blood glucose level to insulin level and C-peptide level and by homeostasis model assessment (HOMA) [β-cell function (HOMA-%B) and insulin sensitivity (HOMA-%S)].

Results

On admission, hyperglycemia (glucose >8.3 mmol/l) was present in 33% of the children. Shock and sepsis survivors had higher blood glucose levels compared with shock non-survivors. Blood glucose level on admission correlated positively with plasma insulin, C-peptide, cortisol, age and glucose intake. Multiple regression analysis revealed that both age and plasma insulin on admission were significantly related to blood glucose. On admission, 62% of the hyperglycemic children had overt insulin resistance (glucose >8.3 mmol/l and HOMA-%S <50%); 17% had β-cell dysfunction (glucose >8.3 mmol/l and HOMA-%B <50%) and 21% had both insulin resistance and β-cell dysfunction. Hyperglycemia was present in 11% and 8% of the children at 24 and 48 hours after admission, respectively.

Conclusions

Children with meningococcal disease often show hyperglycemia on admission. Both insulin resistance and β-cell dysfunction play a role in the occurrence of hyperglycemia. Normalization of blood glucose levels occurs within 48 hours, typically with normal glucose intake and without insulin treatment.
Administration of hydrogen sulfide via extracorporeal membrane lung ventilation in sheep with partial cardiopulmonary bypass perfusion: a proof of concept study on metabolic and vasomotor effects
Authors: Derwall Matthias , Francis Roland CE , Kida Kotaro , Bougaki Masahiko , Crimi Ettore , Adrie Christophe , Zapol Warren M , Ichinose Fumito
Published: February 2011

Introduction

Although inhalation of 80 parts per million (ppm) of hydrogen sulfide (H2S) reduces metabolism in mice, doses higher than 200 ppm of H2S were required to depress metabolism in rats. We therefore hypothesized that higher concentrations of H2S are required to reduce metabolism in larger mammals and humans. To avoid the potential pulmonary toxicity of H2S inhalation at high concentrations, we investigated whether administering H2S via ventilation of an extracorporeal membrane lung (ECML) would provide means to manipulate the metabolic rate in sheep.

Methods

A partial venoarterial cardiopulmonary bypass was established in anesthetized, ventilated (fraction of inspired oxygen = 0.5) sheep. The ECML was alternately ventilated with air or air containing 100, 200, or 300 ppm H2S for intervals of 1 hour. Metabolic rate was estimated on the basis of total CO2 production (

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Results

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, and cardiac output ranged within normal physiological limits when the ECML was ventilated with air and did not change after administration of up to 300 ppm H2S. Administration of 100, 200 and 300 ppm H2S increased pulmonary vascular resistance by 46, 52 and 141 dyn·s/cm5, respectively (all P ≤ 0.05 for air vs. 100, 200 and 300 ppm H2S, respectively), and mean pulmonary artery pressure by 4 mmHg (P ≤ 0.05), 3 mmHg (n.s.) and 11 mmHg (P ≤ 0.05), respectively, without changing pulmonary capillary wedge pressure or cardiac output. Exposure to 300 ppm H2S decreased systemic vascular resistance from 1,561 ± 553 to 870 ± 138 dyn·s/cm5 (P ≤ 0.05) and mean arterial pressure from 121 ± 15 mmHg to 66 ± 11 mmHg (P ≤ 0.05). In addition, exposure to 300 ppm H2S impaired arterial oxygenation (PaO2 114 ± 36 mmHg with air vs. 83 ± 23 mmHg with H2S; P ≤ 0.05).

Conclusions

Administration of up to 300 ppm H2S via ventilation of an extracorporeal membrane lung does not reduce

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CO

2

and

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, but causes dose-dependent pulmonary vasoconstriction and systemic vasodilation. These results suggest that administration of high concentrations of H2S in venoarterial cardiopulmonary bypass circulation does not reduce metabolism in anesthetized sheep but confers systemic and pulmonary vasomotor effects.
Transthoracic echocardiography for the diagnosis of left ventricular thrombosis in the postoperative care unit
Authors: Saranteas Theodosios , Alevizou Anastasia , Tzoufi Maria , Panou Fotios , Kostopanagiotou Georgia
Published: February 2011

Introduction

Transthoracic echocardiography (TTE) is a reliable, noninvasive imaging method that is useful in the evaluation of cardiovascular thrombosis. We conducted a retrospective study of all the echocardiograms from patients in the postoperative care unit to assess the role of TTE in thrombus identification in the left ventricle.

Methods

This retrospective database evaluation included all echocardiograms during a 14-month period. The echocardiographic examination protocol included the subcostal four-chamber view, the apical four-chamber view, the apical two-chamber view and the parasternal view, along the long and short axes in both spontaneously and mechanically ventilated patients. All echocardiograms were obtained within the 48 hours immediately following surgery.

Results

In total, 160 postoperative echocardiograms were obtained from 160 patients and resulted in the detection of five cases of left ventricular thrombosis. Subgroup analysis showed that 21 and 35 of the 160 patients examined had either dilated or ischemic cardiomyopathy, respectively. In these patients, preoperative echocardiograms had been obtained recently prior to surgery and were negative for left ventricular thrombus. In three of 35 patients with ischemic cardiomyopathy and two of 21 patients with dilated cardiomyopathy, thrombus was identified in the left ventricle. The thrombi were mobile, uncalcified and pedunculated and were located in the apex of the left ventricle. In addition, no clinical consequences of the left ventricular thrombi were recorded.

Conclusions

Low-flow conditions in heart chambers due to ischemic or dilated cardiomyopathy in conjunction with the hypercoagulability caused by perioperative prothrombotic factors may lead to thrombotic events in the left ventricle.
Availability of critical care resources to treat patients with severe sepsis or septic shock in Africa: a self-reported, continent-wide survey of anaesthesia providers
Authors: Baelani Inipavudu , Jochberger Stefan , Laimer Thomas , Otieno Dave , Kabutu Jane , Wilson Iain , Baker Tim , Dünser Martin W
Published: February 2011

Introduction

It is unknown whether resources necessary to implement the Surviving Sepsis Campaign guidelines and sepsis bundles are available in Africa. This self-reported, continent-wide survey compared the availability of these resources between African and high-income countries, and between two African regions (Sub-Sahara Africa vs. South Africa, Mauritius and the Northern African countries).

Methods

The study was conducted as an anonymous questionnaire-based, cross-sectional survey among anaesthesia providers attending a transcontinental congress. Based on the respondents' country of practice, returned questionnaires were grouped into African and high-income countries. The questionnaire contained 74 items and evaluated all material resources required to implement the most recent Surviving Sepsis Campaign guidelines. Group comparisons were performed with the Chi2, Fisher's Exact or Mann Whitney U test, as appropriate.

Results

The overall response rate was 74.3% (318/428). Three-hundred-seven questionnaires were analysed (African countries, n = 263; high-income countries, n = 44). Respondents from African hospitals were less likely to have an emergency room (85.5 vs. 97.7%, P = 0.03) or intensive care unit (73.8 vs. 100%, P < 0.001) than respondents from high-income countries. Drugs, equipment, and disposable materials required to implement the Surviving Sepsis Campaign guidelines or sepsis bundles were less frequently available in African than high-income countries. Of all African and Sub-Saharan African countries, 1.5% (4/263) and 1.2% (3/248) of respondents had the resources available to implement the Surviving Sepsis Campaign guidelines in entirety. The percentage of implementable recommendations was lower in African than in high-income countries (72.6 (57.7 to 87.7)% vs. 100 (100 to 100)%, P < 0.001) and lower in Sub-Saharan African countries than South Africa, Mauritius, and the Northern African countries (72.6 (56.2 to 86.3)% vs. 90.4 (71.2 to 94.5)%, P = 0.02).

Conclusions

The results of this self-reported survey strongly suggest that the most recent Surviving Sepsis guidelines cannot be implemented in Africa, particularly not in Sub-Saharan Africa, due to a shortage of required hospital facilities, equipment, drugs and disposable materials. However, availability of resources to implement the majority of strong Surviving Sepsis Campaign recommendations and the sepsis bundles may allow modification of current sepsis guidelines based on available resources and implementation of a substantial number of life-saving interventions into sepsis care in Africa.
Clara cell protein in bronchoalveolar lavage fluid: a predictor of ventilator-associated pneumonia?
Authors: Vanspauwen Marijke J , Linssen Catharina FM , Bruggeman Cathrien A , Jacobs Jan A , Drent Marjolein , Bergmans Dennis CJJ , van Mook Walther NKA
Published: February 2011

Introduction

Clara cell protein 10 (CC-10) has been associated with inflammatory and infectious pulmonary diseases. This study evaluates CC-10 concentrations in bronchoalveolar lavage (BAL) fluid as a potential marker of ventilator-associated pneumonia (VAP).

Methods

Between January 2003 and December 2007, BAL fluid samples obtained from critically ill patients at the intensive care unit of the Maastricht University Medical Centre clinically suspected of having VAP were included. Patients were divided into two groups: (1) microbiologically confirmed VAP (the VAP group) and (2) microbiologically unconfirmed VAP (the non-VAP group). The concentration of CC-10 was measured by means of a commercially available enzyme-linked immunosorbent assay kit, and retrospective analysis was performed. Areas under the curve of receiver operating characteristic curves were calculated for CC-10 concentrations.

Results

A total of 196 patients (122 men, 74 women) were included. A total of 79 (40%) of 196 cases of suspected VAP were microbiologically confirmed. The median CC-10 concentration in the VAP group was 3,019 ng/mL (range, 282 to 65,546 ng/mL) versus 2,504 ng/mL (range, 62 to 30,240 ng/mL) in the non-VAP group (P = 0.03). There was no significant difference in CC-10 concentrations between patients treated with or without corticosteroids (P = 0.26) or antibiotic therapy (P = 0.9). The CC-10 concentration did not differ significantly between patients with Gram-positive versus Gram-negative bacteria that caused the VAP (P = 0.06). However, CC-10 concentrations did differ significantly between the late-onset VAP group and the non-VAP group.

Conclusions

The CC-10 concentration in BAL fluid yielded low diagnostic accuracy in confirming the presence of VAP.
High levels of circulating leukocyte microparticles are associated with better outcome in acute respiratory distress syndrome
Authors: Guervilly Christophe , Lacroix Romaric , Forel Jean-Marie , Roch Antoine , Camoin-Jau Laurence , Papazian Laurent , Dignat-George Françoise
Published: February 2011

Introduction

The current study has addressed the presence and the cellular origin of microparticles (MP) isolated from bronchoalveolar lavage (BAL) fluid and from blood samples from patients with acute respiratory distress syndrome (ARDS). Their prognostic interest was also investigated.

Methods

Fifty-two patients were included within the first 24 hours of ARDS. They were compared to spontaneous breathing (SB) and ventilated control (VC) groups. Bronchoalveolar lavage (BAL) and blood samples were obtained on Day 1 and Day 3 in an ARDS group. Leukocyte microparticles (LeuMP), neutrophil microparticles (NeuMP), endothelial microparticles (EMP), and platelet microparticles (PMP) were measured in arterial blood and in BAL samples by flow cytometry. Mortality from all causes was recorded at Day 28.

Results

All MP subpopulations were detected in BAL. However, only LeuMP and NeuMP were elevated in ARDS patients compared to the SB group (P = 0.002 for both). Among ARDS patients, higher levels of LeuMP were detected in blood (Day 1) and in BAL (Day 3) in survivors as compared with the non survivors. Circulating LeuMP >60 elements/microliter detectable on Day 1 of ARDS, was associated with a higher survival rate (odds ratio, 5.26; 95% confidence interval, 1.10 to 24.99; P = 0.037).

Conclusions

The identification of the cellular origin of microparticles at the onset of ARDS has identified LeuMP as a biomarker of prognostic significance. The higher levels of LeuMP in survivors could be associated with a protective role of this MP subpopulation. This hypothesis needs further investigations.
Characterization of the radioresponse of human apical papilla-derived cells
Authors: Abe Shigehiro , Hamada Keiichi , Yamaguchi Satoshi , Amagasa Teruo , Miura Masahiko
Published: February 2011

Background

The purpose of this study was to characterize the radiobiological properties of stem/progenitor cells derived from apical papilla-derived cells (APDCs) compared to bulk APDCs.

Methods

APDCs were isolated from freshly extracted human third molars with immature apices. Multipotent spheres, which are thought to contain an enriched population of stem/progenitor cells, were formed from the APDCs, using a neurosphere culture technique. After γ-irradiation, papillary sphere-forming cells (PSFCs) and bulk APDCs were subjected to radiosensitivity and hard tissue-forming assays.

Results

Compared to bulk APDCs, the PSFCs exhibited a radioresistant phenotype and a higher capacity for DNA double strand break repair. Irradiation induced a significant increase in a senescence-like phenotype in both cell types. Neither type of cells exhibited a significant induction of apoptotic changes after 8 Gy of irradiation. Ability to form hard tissue in vivo was significantly decreased in PSFCs, but not in APDCs following 4 Gy of irradiation.

Conclusions

We demonstrated for the first time that stem/progenitor cells derived from APDCs exhibit a radioresistant phenotype; however, the hard tissue forming ability in vivo, but not bulk APDCs, was significantly reduced after irradiation.