bluuebunny/crossref_metadata_2025 huggingface dataset:
High-throughput gene expression analysis at the level of single proteins using a microfluidic turbidostat and automated cell tracking
Authors: Ullman G. , Wallden M. , Marklund E. G. , Mahmutovic A. , Razinkov Ivan , Elf J.
Published: December 2012

We have developed a method combining microfluidics, time-lapsed single-molecule microscopy and automated image analysis allowing for the observation of an excess of 3000 complete cell cycles of exponentially growing
Escherichia coli
cells per experiment. The method makes it possible to analyse the rate of gene expression at the level of single proteins over the bacterial cell cycle. We also demonstrate that it is possible to count the number of non-specifically DNA binding LacI–Venus molecules using short excitation light pulses. The transcription factors are localized on the nucleoids in the cell and appear to be uniformly distributed on chromosomal DNA. An increase in the expression of LacI is observed at the beginning of the cell cycle, possibly because some gene copies are de-repressed as a result of partitioning inequalities at cell division. Finally, a size–growth rate uncertainty relation is observed where cells living in rich media vary more in the length at birth than in generation time, and the opposite is true for cells living in poorer media.
Surface-enhanced Raman spectroscopy at single-molecule scale and its implications in biology
Authors: Wang Yuling , Irudayaraj Joseph
Published: December 2012

Single-molecule (SM) spectroscopy has been an exciting area of research offering significant promise and hope in the field of sensor development to detect targets at ultra-low levels down to SM resolution. To the experts and developers in the field of surface-enhanced Raman spectroscopy (SERS), this has often been a challenge and a significant opportunity for exploration. Needless to say, the opportunities and excitement of this multidisciplinary area impacts span the fields of physics, chemistry and engineering, along with a significant thrust in applications constituting areas in medicine, biology, environment and agriculture among others. In this review, we will attempt to provide a quick snapshot of the basics of SM-SERS, nanostructures and devices that can enable SM Raman measurement. We will conclude with a discussion on SERS implications in biomedical sciences.
Imaging the cell surface and its organization down to the level of single molecules
Authors: Klenerman David , Shevchuk Andrew , Novak Pavel , Korchev Yuri E. , Davis Simon J.
Published: December 2012

Determining the organization of key molecules on the surface of live cells in two dimensions and how this changes during biological processes, such as signalling, is a major challenge in cell biology and requires methods with nanoscale spatial resolution and high temporal resolution. Here, we review biophysical tools, based on scanning ion conductance microscopy and single-molecule fluorescence and the combination of both of these methods, which have recently been developed to address these issues. We then give examples of how these methods have been be applied to provide new insights into cell membrane organization and function, and discuss some of the issues that will need to be addressed to further exploit these methods in the future.
Inferring diffusion in single live cells at the single-molecule level
Authors: Robson Alex , Burrage Kevin , Leake Mark C.
Published: December 2012

The movement of molecules inside living cells is a fundamental feature of biological processes. The ability to both observe and analyse the details of molecular diffusion
in vivo
at the single-molecule and single-cell level can add significant insight into understanding molecular architectures of diffusing molecules and the nanoscale environment in which the molecules diffuse. The tool of choice for monitoring dynamic molecular localization in live cells is fluorescence microscopy, especially so combining total internal reflection fluorescence with the use of fluorescent protein (FP) reporters in offering exceptional imaging contrast for dynamic processes in the cell membrane under relatively physiological conditions compared with competing single-molecule techniques. There exist several different complex modes of diffusion, and discriminating these from each other is challenging at the molecular level owing to underlying stochastic behaviour. Analysis is traditionally performed using
mean square displacements
of tracked particles; however, this generally requires more data points than is typical for single FP tracks owing to photophysical instability. Presented here is a novel approach allowing robust
Bayesian ranking of diffusion
processes to discriminate multiple complex modes probabilistically. It is a computational approach that biologists can use to understand single-molecule features in live cells.
Reversible optical control of cyanine fluorescence in fixed and living cells: optical lock-in detection immunofluorescence imaging microscopy
Authors: Yan Yuling , Petchprayoon Chutima , Mao Shu , Marriott Gerard
Published: December 2012

Optical switch probes undergo rapid and reversible transitions between two distinct states, one of which may fluoresce. This class of probe is used in various super-resolution imaging techniques and in the high-contrast imaging technique of optical lock-in detection (OLID) microscopy. Here, we introduce optimized optical switches for studies in living cells under standard conditions of cell culture. In particular, a highly fluorescent cyanine probe (Cy or Cy3) is directly or indirectly linked to naphthoxazine (NISO), a highly efficient optical switch that undergoes robust, 405/532 nm-driven transitions between a colourless spiro (SP) state and a colourful merocyanine (MC) state. The intensity of Cy fluorescence in these Cy/Cy3-NISO probes is reversibly modulated between a low and high value in SP and MC states, respectively, as a result of Förster resonance energy transfer. Cy/Cy3-NISO probes are targeted to specific proteins in living cells where defined waveforms of Cy3 fluorescence are generated by optical switching of the SP and MC states. Finally, we introduce a new imaging technique (called OLID-immunofluorescence microscopy) that combines optical modulation of Cy3 fluorescence from Cy3/NISO co-labelled antibodies within fixed cells and OLID analysis to significantly improve image contrast in samples having high background or rare antigens.
A critical survey of methods to detect plasma membrane rafts
Authors: Klotzsch Enrico , Schütz Gerhard J.
Published: December 2012

The plasma membrane is still one of the enigmatic cellular structures. Although the microscopic structure is getting clearer, not much is known about the organization at the nanometre level. Experimental difficulties have precluded unambiguous approaches, making the current picture rather fuzzy. In consequence, a variety of different membrane models has been proposed over the years, on the basis of different experimental strategies. Recent data obtained via high-resolution single-molecule microscopy shed new light on the existing hypotheses. We thus think it is a good time for reviewing the consistency of the existing models with the new data. In this paper, we summarize the available models in ten propositions, each of which is discussed critically with respect to the applied technologies and the strengths and weaknesses of the approaches. Our aim is to provide the reader with a sound basis for his own assessment. We close this chapter by exposing our picture of the membrane organization at the nanoscale.
Development of new photon-counting detectors for single-molecule fluorescence microscopy
Authors: Michalet X. , Colyer R. A. , Scalia G. , Ingargiola A. , Lin R. , Millaud J. E. , Weiss S. , Siegmund Oswald H. W. , Tremsin Anton S. , Vallerga John V. , Cheng A. , Levi M. , Aharoni D. , Arisaka K. , Villa F. , Guerrieri F. , Panzeri F. , Rech I. , Gulinatti A. , Zappa F. , Ghioni M. , Cova S.
Published: December 2012

Two optical configurations are commonly used in single-molecule fluorescence microscopy: point-like excitation and detection to study freely diffusing molecules, and wide field illumination and detection to study surface immobilized or slowly diffusing molecules. Both approaches have common features, but also differ in significant aspects. In particular, they use different detectors, which share some requirements but also have major technical differences. Currently, two types of detectors best fulfil the needs of each approach: single-photon-counting avalanche diodes (SPADs) for point-like detection, and electron-multiplying charge-coupled devices (EMCCDs) for wide field detection. However, there is room for improvements in both cases. The first configuration suffers from low throughput owing to the analysis of data from a single location. The second, on the other hand, is limited to relatively low frame rates and loses the benefit of single-photon-counting approaches. During the past few years, new developments in point-like and wide field detectors have started addressing some of these issues. Here, we describe our recent progresses towards increasing the throughput of single-molecule fluorescence spectroscopy in solution using parallel arrays of SPADs. We also discuss our development of large area photon-counting cameras achieving subnanosecond resolution for fluorescence lifetime imaging applications at the single-molecule level.
The physics of life: one molecule at a time
Authors: Leake Mark C.
Published: December 2012

The esteemed physicist Erwin Schrödinger, whose name is associated with the most notorious equation of quantum mechanics, also wrote a brief essay entitled ‘What is Life?’, asking: ‘How can the events in space and time which take place within the spatial boundary of a living organism be accounted for by physics and chemistry?’ The 60+ years following this seminal work have seen enormous developments in our understanding of biology on the molecular scale, with physics playing a key role in solving many central problems through the development and application of new physical science techniques, biophysical analysis and rigorous intellectual insight. The early days of single-molecule biophysics research was centred around molecular motors and biopolymers, largely divorced from a real physiological context. The new generation of single-molecule bioscience investigations has much greater scope, involving robust methods for understanding molecular-level details of the most fundamental biological processes in far more realistic, and technically challenging, physiological contexts, emerging into a new field of ‘single-molecule cellular biophysics’. Here, I outline how this new field has evolved, discuss the key active areas of current research and speculate on where this may all lead in the near future.
Towards physiological complexity with
in vitro
single-molecule biophysics
Authors: Duzdevich Daniel , Greene Eric C.
Published: December 2012

Single-molecule biology has matured in recent years, driven to greater sophistication by the development of increasingly advanced experimental techniques. A progressive appreciation for its unique strengths is attracting research that spans an exceptionally broad swath of physiological phenomena—from the function of nucleosomes to protein diffusion in the cell membrane. Newfound enthusiasm notwithstanding, the single-molecule approach is limited to an intrinsically defined set of biological questions; such limitation applies to all experimental approaches, and an explicit statement of the boundaries delineating each set offers a guide to most fruitfully orienting
in vitro
single-molecule research in the future. Here, we briefly describe a simple conceptual framework to categorize how submolecular, molecular and intracellular processes are studied. We highlight the domain of single-molecule biology in this scheme, with an emphasis on its ability to probe various forms of heterogeneity inherent to populations of discrete biological macromolecules. We then give a general overview of our high-throughput DNA curtain methodology for studying protein–nucleic acid interactions, and by contextualizing it within this framework, we explore what might be the most enticing avenues of future research. We anticipate that a focus on single-molecule biology's unique strengths will suggest a new generation of experiments with greater complexity and more immediately translatable physiological relevance.
Single-molecule imaging in live bacteria cells
Authors: Ritchie Ken , Lill Yoriko , Sood Chetan , Lee Hochan , Zhang Shunyuan
Published: December 2012

Bacteria, such as
Escherichia coli
and
Caulobacter crescentus
, are the most studied and perhaps best-understood organisms in biology. The advances in understanding of living systems gained from these organisms are immense. Application of single-molecule techniques in bacteria have presented unique difficulties owing to their small size and highly curved form. The aim of this review is to show advances made in single-molecule imaging in bacteria over the past 10 years, and to look to the future where the combination of implementing such high-precision techniques in well-characterized and controllable model systems such as
E. coli
could lead to a greater understanding of fundamental biological questions inaccessible through classic ensemble methods.
In SilicoEvolution of Gene Cooption in Pattern-Forming Gene Networks
Authors: Spirov Alexander V. , Sabirov Marat A. , Holloway David M.
Published: December 2012

Gene recruitment or cooption occurs when a gene, which may be part of an existing gene regulatory network (GRN), comes under the control of a new regulatory system. Such re-arrangement of pre-existing networks is likely more common for increasing genomic complexity than the creation of new genes. Using evolutionary computations (EC), we investigate how cooption affects the evolvability, outgrowth and robustness of GRNs. We use a data-driven model of insect segmentation, for the fruit fly Drosophila, and evaluate fitness by robustness to maternal variability—a major constraint in biological development. We compare two mechanisms of gene cooption: a simpler one with gene Introduction and Withdrawal operators; and one in which GRN elements can be altered by transposon infection. Starting from a minimal 2-gene network, insufficient for fitting the Drosophila gene expression patterns, we find a general trend of coopting available genes into the GRN, in order to better fit the data. With the transposon mechanism, we find co-evolutionary oscillations between genes and their transposons. These oscillations may offer a new technique in EC for overcoming premature convergence. Finally, we comment on how a differential equations (in contrast to Boolean) approach is necessary for addressing realistic continuous variation in biochemical parameters.
Biofilm Formation and Adherence Characteristics ofListeria ivanoviiStrains Isolated from Ready-to-Eat Foods in Alice, South Africa
Authors: Nyenje Mirriam E. , Green Ezekiel , Ndip Roland N.
Published: December 2012

The present study was carried out to investigate the potential ofListeria ivanoviiisolates to exist as biofilm structures. The ability ofListeria ivanoviiisolates to adhere to a surface was determined using a microtiter plate adherence assay whereas the role of cell surface properties in biofilm formation was assessed using the coaggregation and autoaggregation assays. Seven reference bacterial strains were used for the coaggregation assay. The degree of coaggregation and autoaggregation was determined. The architecture of the biofilms was examined under SEM. A total of 44 (88%) strains adhered to the wells of the microtiter plate while 6 (12%) did not adhere. The coaggregation index ranged from 12 to 77% while the autoaggregation index varied from 11 to 55%. The partner strains ofS. aureus,S. pyogenes,P. shigelloides, andS. sonneidisplayed coaggregation indices of 75% each, whileS. Typhimurium,A. hydrophila, andP. aeruginosaregistered coaggregation indices of 67%, 58%, and 50%, respectively. The ability ofL. ivanoviiisolates to form single and multispecies biofilms at 25°C is of great concern to the food industry where these organisms may adhere to kitchen utensils and other environments leading to cross-contamination of food processed in these areas.
Development of Methane and Nitrous Oxide Emission Factors for the Biomass Fired Circulating Fluidized Bed Combustion Power Plant
Authors: Cho Chang-Sang , Sa Jae-Hwan , Lim Ki-Kyo , Youk Tae-Mi , Kim Seung-Jin , Lee Seul-Ki , Jeon Eui-Chan
Published: December 2012

This study makes use of this distinction to analyze the exhaust gas concentration and fuel of the circulating fluidized bed (CFB) boiler that mainly uses wood biomass, and to develop the emission factors of Methane (CH4), Nitrous oxide (N2O). The fuels used as energy sources in the subject working sites are Wood Chip Fuel (WCF), RDF and Refused Plastic Fuel (RPF) of which heating values are 11.9 TJ/Gg, 17.1 TJ/Gg, and 31.2 TJ/Gg, respectively. The average concentrations of CH4and N2O were measured to be 2.78 ppm and 7.68 ppm, respectively. The analyzed values and data collected from the field survey were used to calculate the emission factor of CH4and N2O exhausted from the CFB boiler. As a result, the emission factors of CH4and N2O are 1.4 kg/TJ (0.9–1.9 kg/TJ) and 4.0 kg/TJ (2.9–5.3 kg/TJ) within a 95% confidence interval. Biomass combined with the combustion technology for the CFB boiler proved to be more effective in reducing the N2O emission, compared to the emission factor of the CFB boiler using fossil fuel.
Recruitment of Arf1-GDP to Golgi by Glo3p-Type ArfGAPs Is Crucial for Golgi Maintenance and Plant Growth
Authors: Min Myung Ki , Jang Mihue , Lee Myounghui , Lee Junho , Song Kyungyoung , Lee Yongjik , Choi Kwan Yong , Robinson David G. , Hwang Inhwan
Published: December 2012

ADP-ribosylation factor1 (Arf1), a member of the small GTP-binding proteins, plays a pivotal role in protein trafficking to multiple organelles. In its GDP-bound form, Arf1 is recruited from the cytosol to organelle membranes, where it functions in vesicle-mediated protein trafficking. However, the mechanism of Arf1-GDP recruitment remains unknown. Here, we provide evidence that two Glo3p-type Arf GTPase-activating proteins (ArfGAPs), ArfGAP domain8 (AGD8) and AGD9, are involved in the recruitment of Arf1-GDP to the Golgi apparatus in Arabidopsis (Arabidopsis thaliana). RNA interference plants expressing low levels of AGD8 and AGD9 exhibited abnormal Golgi morphology, inhibition of protein trafficking, and arrest of plant growth and development. In RNA interference plants, Arf1 was poorly recruited to the Golgi apparatus. Conversely, high levels of AGD8 and AGD9 induced Arf1 accumulation at the Golgi and suppressed Golgi disruption and inhibition of vacuolar trafficking that was caused by overexpression of AGD7. Based on these results, we propose that the Glo3p-type ArfGAPs AGD8 and AGD9 recruit Arf1-GDP from the cytosol to the Golgi for Arf1-mediated protein trafficking, which is essential for plant development and growth.
In Planta Stage-Specific Fungal Gene Profiling Elucidates the Molecular Strategies of Fusarium graminearum Growing inside Wheat Coleoptiles
Authors: Zhang Xiao-Wei , Jia Lei-Jie , Zhang Yan , Jiang Gang , Li Xuan , Zhang Dong , Tang Wei-Hua
Published: December 2012

The ascomycete Fusarium graminearum is a destructive fungal pathogen of wheat (Triticum aestivum). To better understand how this pathogen proliferates within the host plant, we tracked pathogen growth inside wheat coleoptiles and then examined pathogen gene expression inside wheat coleoptiles at 16, 40, and 64 h after inoculation (HAI) using laser capture microdissection and microarray analysis. We identified 344 genes that were preferentially expressed during invasive growth in planta. Gene expression profiles for 134 putative plant cell wall–degrading enzyme genes suggest that there was limited cell wall degradation at 16 HAI and extensive degradation at 64 HAI. Expression profiles for genes encoding reactive oxygen species (ROS)–related enzymes suggest that F. graminearum primarily scavenges extracellular ROS before a later burst of extracellular ROS is produced by F. graminearum enzymes. Expression patterns of genes involved in primary metabolic pathways suggest that F. graminearum relies on the glyoxylate cycle at an early stage of plant infection. A secondary metabolite biosynthesis gene cluster was specifically induced at 64 HAI and was required for virulence. Our results indicate that F. graminearum initiates infection of coleoptiles using covert penetration strategies and switches to overt cellular destruction of tissues at an advanced stage of infection.
Adding a cost of resistance description extends the ability of virus–host model to explain observed patterns in structure and function of pelagic microbial communities
Authors: Våge Selina , Storesund Julia E. , Thingstad T. Frede
Published: December 2012

By adding a generic description of cost of resistance (COR) to the existing ‘killing‐the‐winner’ model, we show how this expands the model's explanatory power to include rank‐abundance relationships in the host population. The model can predict a counter‐intuitive relationship previously suggested in the literature, where abundant viruses are associated with rare hosts and vice versa. The model explains the observed dominance of slow‐growing prokaryotes as the result of successful defence strategies, rather than as dormancy of hosts lacking essential substrates. In addition to these important conceptual aspects, the model is able to reproduce realistic values for virus : host ratios and partitioning of bacterial production between predatory loss and viral lysis. A high COR is also shown to increase the community's richness and Shannon diversity index. This model thus not only couples life strategies at the cellular level with system properties, but it also links the two system level properties of biogeochemical flows and diversity to each other. The model operates with host groups, and consequences for biodiversity when interpreting these groups in terms of species and strains are discussed.
Cyst fluid carcinoembryonic antigen concentration and cytology by endosonography‐guided fine needle aspiration in predicting malignant pancreatic mucinous cystic neoplasms
Authors: Zhan Xian Bao , Wang Bin , Liu Feng , Ye Xiao Fei , Jin Zhen Dong , Li Zhao Shen
Published: December 2012

Objective

To assess the value of carcinoembryonic antigen (CEA) level and cytology examination obtained by endosonography‐guided fine needle aspiration (EUS‐FNA) in predicting the malignancy of pancreatic mucinous cystic neoplasm (MCN).

Methods

The data of patients with pancreatic MCN who underwent EUS‐FNA in Changhai Hospital, Second Military Medical University (Shanghai, China) from November 2005 to April 2010 were collected and analyzed. The area under receiver operating characteristic (ROC) curve of cyst fluid CEA, sensitivity, specificity, positive (PPV) and negative predictive value (NPV) of the cytology as well as cyst fluid CEA were determined.

Results

Of the 20 MCNs confirmed by surgical pathology, 10 were malignant and the remainder were premalignant. Cytology had some value in differentiating malignant from premalignant MCN with a sensitivity of 60.0%, specificity of 100.0%, PPV of 100.0% and NPV of 71.4%. CEA of > 692.8 ng/mL was able to predict malignancy (P = 0.007) with sensitivity of 80.0%, specificity of 90.0%, PPV of 88.9% and NPV of 81.8%, and its area under ROC curve was 0.855.

Conclusion

Cyst fluid CEA level and cytology obtained by EUS‐FNA are useful for predicting the malignancy of pancreatic MCN.
Choroid plexus tumours: Classification, MR imaging findings and pathological correlation
Authors: Yan Chenggong , Xu Yikai , Feng Jie , Sun Chongpeng , Zhang Ge , Shi Jie , Hao Peng , Wu Yuankui , Lin Bingquan
Published: December 2012

Introduction

Choroid plexus tumours (CPTs) are extremely rare intraventricular neoplasms and are prone to bleeding during surgery. The purpose of this study was to summarise the MR imaging characteristics of 13 CPT cases.

Methods

Magnetic resonance images of 13 patients (six men and seven women; mean age 21.1 years) with pathologically proved CPTs were retrospectively reviewed. MR findings of the tumours were evaluated, with emphasis on their location, size, shape, internal architecture, margin and pattern and degree of enhancement. Differences in signal intensity characteristics were also investigated on MR images and analysed according to histological subtypes.

Results

Lesions were in the lateral ventricles (n = 7), fourth ventricle (n = 5) and cisterna magna (n = 1), with a mean size of 5.0 cm (range 2.0–7.9 cm). The tumour parenchyma was a mixture of nodular or patchy areas of inhomogeneous isointense to slightly hyperintense signal on T2‐weighted images. On postcontrast MR images, all lesions, except for one, had moderate to marked contrast enhancement. Multiple tortuous areas of ‘flow void’ signal extended through all the tumours except for two. A thin capsule could be seen in six cases.

Conclusion

Observation of large intraventricular tumours with inhomogeneity on T2‐weighted images and flow void is suggestive of CPTs. Checking for signs of a thin capsule, extensive peritumoural oedema and necrosis may be useful when classifying CPTs.
In vivo monitoring of Yersinia ruckeri in fish tissues: progression and virulence gene expression
Authors: Méndez J. , Guijarro J. A.
Published: December 2012

In this study, the utilization of bioluminescence imaging (BLI) allowed us to define the progression of Yersinia ruckeri during the infection of rainbow trout. A luminescent Y. ruckeri 150 strain was engineered using the pCS26‐Pac plasmid containing the lux operon from Photorhabdus luminescens. Two different models of infection of rainbow trout were defined depending on the route in which bacteria were administered, being the gut the major organ affected following bath immersion. This indicates that this organ is important for bacterial dissemination inside the fish and the establishment of the infection. Moreover, the expression of three previously selected operons by in vivo expression technology (IVET) was analysed, the yhlBA involved in the production of a haemolysin, the cdsAB related to the uptake of cysteine and the yctCBA implicated in citrate uptake. Apart from these factors, the expression of yrp1 encoding a serralysin metalloprotease involved in pathogenesis was also analysed. The results indicated that all of the assayed promoters were expressed during infection of rainbow trout. In addition to these findings, the methodology described in this work constitutes a useful model for studying the infection process in other fish pathogenic bacteria.
Fully thoracoscopic versus conventional open resection for esophageal carcinoma: A perioperative comparison
Authors: Wu Xiangsheng , He Jingkang , Jiang Huichuan , Song Xinyu , Tang Xing , Shen Jian , Xu Chengcheng
Published: December 2012

Background

To compare the efficacy of patients undergoing esophagectomy for cancer in video‐assisted thoracoscopic surgery (VATS) versus traditional open surgery (TOS) in the perioperative period, along with the advantages and disadvantages of each.

Methods

A retrospective analysis of 108 patients, who underwent esophagectomy between September 2011 and February 2012 in our department, was performed. Patients were divided into two groups based on operative technique (VATS vs. TOS), with 50 patients in the VATS group and 58 patients in the TOS group. Operative duration, intraoperative blood loss, intraoperative blood transfusion, number of lymph nodes harvested, postoperative pain score, period of time requiring chest tube drainage, complications, hospital stay, and hospital costs, were all statistically analyzed between the two groups.

Results

There was no statistical difference between the two groups with regard to operative duration or number of lymph nodes harvested. The VATS group had significantly less intraoperative blood loss, intraoperative blood transfusion, postoperative pain, earlier ambulation, shorter postoperative hospital stay, and a shorter period of time requiring chest tube drainage. The amount of drainage was significantly lower in the TOS group (P < 0.05). Pulmonary complication (pneumonia and pleural effusion) was less prevalent among the VATS group.

Conclusion

Compared with TOS, VATS‐assisted esophagectomy is less traumatic with lower intraoperative blood loss, faster recovery, and a better overall outcome.
Ambulant 24‐h glucose rhythms mark calendar and biological age in apparently healthy individuals
Authors: Wijsman Carolien A. , van Heemst Diana , Hoogeveen Evelien S. , Slagboom P. Eline , Maier Andrea B. , de Craen Anton J. M. , van der Ouderaa Frans , Pijl Hanno , Westendorp Rudi G. J. , Mooijaart Simon P.
Published: December 2012

Glucose metabolism marks health and disease and is causally inferred in the aging process. Ambulant continuous glucose monitoring provides 24‐h glucose rhythms under daily life conditions. We aimed to describe ambulant 24‐h glucose rhythms measured under daily life condition in relation to calendar and biological age in apparently healthy individuals. In the general population and families with propensity for longevity, we studied parameters from 24‐h glucose rhythms; glucose levels; and its variability, obtained by continuous glucose monitoring. Participants were 21 young (aged 22–37 years), 37 middle‐aged (aged 44–72 years) individuals from the general population, and 26 middle‐aged (aged 52–74 years) individuals with propensity for longevity. All were free of diabetes. Compared with young individuals, middle‐aged individuals from the general population had higher mean glucose levels (5.3 vs. 4.7 mmol L−1, P < 0.001), both diurnally (P < 0.001) and nocturnally (P = 0.002). Glucose variability was higher in the middle‐aged compared with the young (standard deviation 0.70 vs. 0.57 mmol L−1, P = 0.025). Compared with middle‐aged individuals from the general population, middle‐aged individuals with propensity for longevity had lower overall mean glucose levels (5.2 vs. 5.4 mmol L−1, P = 0.047), which were more different nocturnally (4.8 vs. 5.2 mmol L−1, P = 0.003) than diurnally (5.3 vs. 5.5 mmol L−1, P = 0.14). There were no differences in glucose variability between these groups. Results were independent of body mass index. Among individuals without diabetes, we observed significantly different 24‐h glucose rhythms depending on calendar and biological age.
Establishing an Emergency Medicine Education Research Network
Authors: Newgard Craig D. , Beeson Michael S. , Kessler Chad S. , Kuppermann Nathan , Linden Judith A. , Gallahue Fiona , Wolf Stephen , Hatten Benjamin , Akhtar Saadia , Dooley‐Hash Suzanne L. , Yarris Lalena
Published: December 2012

This project was developed from the research network track at the 2012 Academic Emergency Medicine consensus conference on education research in emergency medicine (EM). Using a combination of consensus techniques, the modified Delphi method, and qualitative research methods, the authors describe multiple aspects of developing, implementing, managing, and growing an EM education research network. A total of 175 conference attendees and 24 small‐group participants contributed to discussions regarding an education research network; participants were experts in research networks, education, and education research. This article summarizes relevant conference discussions and expert opinion for recommendations on the structure of an education research network, basic operational framework, site selection, leadership, subcommittees, guidelines for authorship, logistics, and measuring success while growing and maintaining the network.
Comparison of current staging systems for advanced hepatocellular carcinoma not amendable to locoregional therapy as inclusion criteria for clinical trials
Authors: Li Xing , Dong Min , Lin Qu , Chen Zhan‐Hong , Ma Xiao‐Kun , Xing Yan‐Fang , Wan Xiang‐Bo , Wen Jing‐Yun , Wei Li , Chen Jie , Wu Xiang‐Yuan
Published: December 2012

Aims

The prognosis of patients with advanced hepatocellular carcinoma (HCC) is poor and testing drug efficacy in clinical trials is hazardous. This study was aimed to evaluate different prognostic scoring systems for HCC in estimating prognosis (3‐month survival and overall survival (OS)).

Methods

From November 2008 to April 2010, 208 patients with advanced HCC who were not amendable to locoregional therapy were included in this study. Data were collected to classify patients according to the following: the Japanese integrated staging scoring system, TNM stage by the Liver Cancer Study Group of Japan criteria, TNM 6th edn, the cancer of the liver Italian program scoring system (CLIP), the advanced liver cancer prognostic system (ALCPS), the model of end‐stage liver disease, the Groupe d'étude et de Traitement du Carcinome Hepatocellulaire (GETCH) scoring system, the Chinese University prognostic index staging system (CUPI), the Okuda scoring system, the Child–Pugh score, the Tokyo scoring system and the Barcelona Clinic liver cancer staging. Survival analysis and relative operating characteristic (ROC) were utilized to access the prognostic value of each scoring system.

Results

ALCPS performed best, with the largest area under the ROC curve in predicting 3‐month OS (sensitivity 76.32%, specificity 78.72%). CLIP and CUPI were similar to ALCPS in prognostic discrimination but with relatively lower power.

Conclusions

ALCPS, CLIP and CUPI are the preferred scoring systems in the prediction of OS and 3‐month survival among the 12 systems analyzed, and should be used as inclusion criteria in clinical trials for advanced HCC patients.
Evaluation of clinical characteristics of Kawasaki syndrome and risk factors for coronary artery abnormalities among children in Denmark
Authors: Patel Amy , Holman Robert C , Callinan Laura S , Sreenivasan Nandini , Schonberger Lawrence B , Fischer Thea K , Belay Ermias D
Published: December 2012

Aim

To examine clinical characteristics, treatment and outcome of Kawasaki syndrome patients in Denmark.

Methods

A retrospective chart review of hospitalization records for children <15 years of age with a Kawasaki syndrome discharge diagnosis identified through the Danish National Patient Registry during 1994 through June 2008 was conducted.

Results

A total of 284 cases <15 years of age were identified as Kawasaki syndrome (n = 279) and atypical Kawasaki syndrome (n = 5); 70.4% were <5 years of age and 64.4% were male. Most patients (91.5%; 258/282) were treated with intravenous immunoglobulin and 74.6% of these patients (191/256) received intravenous immunoglobulin before the 10th day of illness. A total of 37 (13.3%) Kawasaki syndrome patients were diagnosed with coronary artery abnormalities. Not receiving intravenous immunoglobulin treatment before the 10th day of illness, young age and male sex were significantly associated with the development of coronary artery abnormalities.

Conclusions

In Denmark, more than one in 10 children with Kawasaki syndrome develop coronary artery abnormalities. Physicians should increase their index of suspicion for early diagnosis and treatment of Kawasaki syndrome among patients susceptible to increased risk of coronary artery abnormalities, particularly in infants who may have a more atypical presentation of the illness.
The clinical pharmacology of acamprosate
Authors: Kalk Nicola J. , Lingford‐Hughes Anne R.
Published: December 2012

Acamprosate is one of the few medications licensed for prevention of relapse in alcohol dependence, and over time it has proved to be significantly, if moderately, effective, safe and tolerable. Its use is now being extended into other addictions and neurodevelopmental disorders. The mechanism of action of acamprosate has been less clear, but in the decade or more that has elapsed since its licensing, a body of translational evidence has accumulated, in which preclinical findings are replicated in clinical populations. Acamprosate modulates N‐methyl‐d‐aspartic acid receptor transmission and may have indirect effects on γ‐aminobutyric acid type A receptor transmission. It is known to decrease brain glutamate and increase β‐endorphins in rodents and man. Acamprosate diminishes reinstatement in ethanolized rodents and promotes abstinence in humans. Although acamprosate has been called an anticraving drug, its subjective effects are subtle and relate to diminished arousal, anxiety and insomnia, which parallel preclinical findings of decreased withdrawal symptoms in animals treated with acamprosate. Further understanding of the pharmacology of acamprosate will allow appropriate targeting of therapy in individuals with alcohol dependence and extension of its use to other addictions.
Surinabant, a selective cannabinoid receptor type 1 antagonist, inhibits Δ9‐tetrahydrocannabinol‐induced central nervous system and heart rate effects in humans
Authors: Klumpers Linda E. , Roy Christine , Ferron Geraldine , Turpault Sandrine , Poitiers Franck , Pinquier Jean‐Louis , van Hasselt Johan G. C. , Zuurman Lineke , Erwich Frank A. S. , van Gerven Joop M. A.
Published: December 2012

Aim

Cannabinoid receptor type 1 (CB1) antagonists have been developed for the treatment of obesity and associated risk factors. Surinabant is a high affinity CB1 antagonist in vitro. The aim of this study was to assess the magnitude of inhibition by surinabant of CNS effects and heart rate induced by Δ9‐tetrahydrocannabinol (THC) in humans.

Methods

This was a double‐blind, placebo‐controlled, randomized, four period six sequence crossover study. Thirty healthy young male occasional cannabis users (<1 per week) were included. A single oral dose of surinabant (5, 20 or 60 mg) or placebo was administered followed 1.5 h later by four intrapulmonary THC doses (2, 4, 6 and 6 mg) or vehicle, administered at 1 h intervals. The wash‐out period was 14–21 days. Subjective and objective pharmacodynamic (PD) measurements were performed. A population PK–PD model for THC and surinabant quantified PK and PD effects.

Results

Surinabant 20 and 60 mg inhibited all THC‐induced PD effects in a similar range for both doses with inhibition ratios ranging from 68.3% (95% CI = 32.5, 104.2; heart rate) to 91.1% (95% CI = 30.3, 151.8; body sway). IC50 ranged from 22.0 ng ml−1 [relative standard error (RSE) = 45.2%; body sway] to 58.8 ng ml−1 (RSE = 44.2%; internal perception). Surinabant 5 mg demonstrated no significant effects.

Conclusions

The dose‐related inhibition by surinabant, without any effect of its own, suggests that this compound behaves as a CB1 receptor antagonist in humans at these concentrations. A single surinabant dose between 5 to 20 mg and above was able to antagonize THC‐induced effects in humans.
Direct renin inhibition in chronic kidney disease
Authors: Persson Frederik , Rossing Peter , Parving Hans‐Henrik
Published: December 2012

For approximately 6 years, the only commercially available direct renin inhibitor, aliskiren, which inhibits the renin‐angiotensin‐aldosterone system at the initial rate limiting step, has been marketed for the treatment of hypertension. Concurrently, much attention has been given to the possibility that renin inhibition could hold potential for improved treatment in patients with chronic kidney disease, with diabetic nephropathy as an obvious group of patients to investigate, as the activity of the renin‐angiotensin‐aldosterone system is enhanced in these patients and as there is an unmet need for improved treatment and prognosis in these patients. Several short term studies have been performed in diabetic nephropathy, showing a consistent effect on the surrogate endpoint lowering of albuminuria, both as monotherapy and in combination with other blockers of the renin‐angiotensin‐aldosterone system. In addition, combination treatment also seemed safe and effective in patients with impaired kidney function. These initial findings formed the basis for the design of a large morbidity and mortality trial investigating aliskiren as add‐on to standard treatment. The study has just concluded, but was terminated early as a beneficial effect was unlikely and there was an increased frequency of side effects. Also in non‐diabetic kidney disease a few intervention studies have been carried out, but there is no ongoing hard outcome study. In this review we provide the current evidence for renin inhibition in chronic kidney disease by reporting the studies published so far as well as a perspective on the future possibilites.
Specific antibody deficiency in children with recurrent respiratory infections: a controlled study with follow-up
Authors: Ruuskanen O , Nurkka A , Helminen M , Viljanen M K , Käyhty H , Kainulainen L
Published: December 2012

Specific antibody deficiency (SAD) to unconjugated pneumococcal vaccine (PPV) is an established primary B cell immunodeficiency. The occurrence and natural history of SAD in children is unclear. We conducted an observational study to identify SAD in children with recurrent respiratory infections. Ninety-nine children, mean age 5·9 (range 2–16) years, with recurrent or severe infections were vaccinated with PPV; serum antibody concentrations for serotypes 4, 6B, 9V, 14, 18C, 19F and 23F were measured before and 2 weeks after vaccination with enzyme immunoassay. The retrospective control group consisted of 89 healthy children matched for age and gender. No children had received previous conjugated pneumococcal vaccine (PCV) or PPV. The structured history of infectious diseases of all participants was collected. Ten of 91 (11%) children (eight excluded due to immunoglobulin G subclass deficiency) with recurrent respiratory infections had SAD. In the control group, three children (3%) responded inadequately to PPV (P = 0·05). Most children with SAD also had many other minor immune defects. After 0·5–5 years (medium 3·8), eight children with SAD were revaccinated with PPV; five responded adequately and three inadequately. Two SAD children were revaccinated with PCV, one developed an adequate and one an inadequate response. Two children with SAD received treatment with intravenous immunoglobulin; the remaining eight children recovered without replacement therapy during the follow-up. SAD is common in young children with recurrent respiratory infections, but it is often transient and resolves itself within a few years without specific treatment.
Human mesenchymal stem cells suppress donor CD4+ T cell proliferation and reduce pathology in a humanized mouse model of acute graft-versus-host disease
Authors: Tobin L M , Healy M E , English K , Mahon B P
Published: December 2012

Acute graft-versus-host disease (aGVHD) is a life-threatening complication following allogeneic haematopoietic stem cell transplantation (HSCT), occurring in up to 30–50% of patients who receive human leucocyte antigen (HLA)-matched sibling transplants. Current therapies for steroid refractory aGVHD are limited, with the prognosis of patients suboptimal. Mesenchymal stem or stromal cells (MSC), a heterogeneous cell population present in many tissues, display potent immunomodulatory abilities. Autologous and allogeneic ex-vivo expanded human MSC have been utilized to treat aGVHD with promising results, but the mechanisms of therapeutic action remain unclear. Here a robust humanized mouse model of aGVHD based on delivery of human peripheral blood mononuclear cells (PBMC) to non-obese diabetic (NOD)-severe combined immunodeficient (SCID) interleukin (IL)-2rγnull (NSG) mice was developed that allowed the exploration of the role of MSC in cell therapy. MSC therapy resulted in the reduction of liver and gut pathology and significantly increased survival. Protection was dependent upon the timing of MSC therapy, with conventional MSC proving effective only after delayed administration. In contrast, interferon (IFN)-γ-stimulated MSC were effective when delivered with PBMC. The beneficial effect of MSC therapy in this model was not due to the inhibition of donor PBMC chimerism, as CD45+ and T cells engrafted successfully in this model. MSC therapy did not induce donor T cell anergy, FoxP3+ T regulatory cells or cause PBMC apoptosis in this model; however, it was associated with the direct inhibition of donor CD4+ T cell proliferation and reduction of human tumour necrosis factor-α in serum.
Neuro‐ophthalmology of invasive fungal sinusitis: 14 consecutive patients and a review of the literature
Authors: Thurtell Matthew J , Chiu Alison LS , Goold Lucy A , Akdal Gulden , Crompton John L , Ahmed Rebekah , Madge Simon N , Selva Dinesh , Francis Ian , Ghabrial Raf , Ananda Arj , Gibson John , Chan Raymond , Thompson Elizabeth O , Rodriguez Michael , McCluskey Peter J , Halmagyi G Michael
Published: December 2012

Background

Invasive fungal sinusitis is a rare condition that usually occurs in immunocompromised patients and often presents as an orbital apex syndrome. It is frequently misdiagnosed on presentation and is almost always lethal without early treatment.

Design

Retrospective case series of 14 consecutive patients with biopsy‐proven invasive fungal sinusitis from four tertiary hospitals.

Participants

Fourteen patients (10 men and 4 women; age range 46–82 years).

Methods

Retrospective chart review of all patients presenting with invasive fungal sinusitis between 1994 and 2010 at each hospital, with a close analysis of the tempo of the disease to identify any potential window of opportunity for treatment.

Main Outcome Measures

Demographic data, background medical history (including predisposing factors), symptoms, signs, radiological findings, histopathological findings, treatment approach and subsequent clinical course were recorded and analysed.

Results

Only one patient was correctly diagnosed at presentation. Only two patients were not diabetic or immunocompromised. The tempo was acute in two patients, subacute in nine patients and chronic in three patients. In the subacute and chronic cases, there was about 1 week of opportunity for treatment, from the time there was a complete orbital apex syndrome, and still a chance for saving the patient, to the time there was central nervous system invasion, which was invariably fatal. Only two patients survived – both had orbital exenteration, as well as antifungal drug treatment.

Conclusions

Invasive fungal sinusitis can, rarely, occur in healthy individuals and should be suspected as a possible cause of a progressive orbital apex syndrome.