bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of suppressing negative memories on intrusions and autobiographical memory specificity
Authors: Geraerts Elke , Hauer Beatrijs J. A. , Wessel Ineke
Published: March 2010

This study examines whether avoidance of negative memories results in intrusions as well as reduced memory specificity. Healthy participants suppressed memories of either a negative or a neutral autobiographical event. Individuals who suppressed negative memories tended to demonstrate smaller increases in negative mood than those who did not suppress their negative target memory. Neither suppression nor valence of the to‐be‐suppressed memory predicted decreases in memory specificity. Target memory‐related intrusions during autobiographical memory retrieval predicted larger reductions in specific memory recall. Our findings are discussed in terms of affect regulation and other accounts of over‐general memory. Copyright © 2010 John Wiley & Sons, Ltd.
Attentional bias for trauma‐film reminders: Towards a laboratory analogue for studying the role of attention in the persistence of intrusive memories
Authors: Verwoerd Johan , Wessel Ineke , de Jong Peter J.
Published: March 2010

Two experiments examined whether exposure to a trauma‐film induced an attentional bias (AB) for intrinsically neutral (visual) reminders of the film. In experiment 1, half of the participants (n = 33) completed a rapid serial visual presentation (RSVP) task after presentation of a trauma film, whereas the other participants (n = 32) engaged in this task without prior film‐exposure. During the RSVP, participants were to detect neutral targets (rotated landscapes) in a stream of images that also included visual distracters consisting of stills depicting persons and objects that featured in the film as well as visual control distracters unrelated to the film. In line with predictions, participants who saw the film prior to the RSVP task showed a relatively strong deterioration of task performance when targets were preceded by film distracters. Results of a second experiment suggested that this AB could be best explained by an acquired motivational salience of the inherently neutral film reminders in the RSVP rather than by a mere familiarity effect. Thus, the current RSVP methodology seems to be a viable analogue method for studying AB after stressful or traumatic experiences. Copyright © 2010 John Wiley & Sons, Ltd.
Current directions at the juncture of clinical and cognitive science: A commentary on the special issue
Authors: MacLeod Colin
Published: March 2010

The 12 experimental papers presented in this special issue brilliantly illustrate the creative and exciting ways in which the exchange of theoretical concepts and experimental methodologies, between cognitive and clinical science, is serving both to deepen our understanding of psychopathology, and to identify new ways of potentially remediating such dysfunction. These papers are not only individually excellent, but collectively they communicate some of the major themes that are presently driving new developments within this rapidly evolving field. In this brief commentary, I reflect upon the contributions made by the current studies to these important themes. I also share some suggestions concerning how future work might profitably build upon this present research, to further enhance theoretical progress and enrich therapeutic innovation. Copyright © 2010 John Wiley & Sons, Ltd.
Controlling Electronic States and Transport Properties at the Level of Single Molecules
Authors: Pan Shuan , Zhao Aidi , Wang Bing , Yang Jinlong , Hou Jianguo
Published: March 2010

Since molecular electronics has been rapidly growing as a promising alternative to conventional electronics towards the ultimate miniaturization of electronic devices through the bottom‐up strategy, it has become a long‐term desire to understand and control the transport properties at the level of single molecules. In this Research News article it is shown that one may modify the electronic states of single molecules and thus control their transport properties through designing and fabrication of functional molecules or manipulating molecules with scanning tunneling microscopy. The rectifying effect of single molecules can be realized by designing a donor–barrier–acceptor architecture of Pyridine–σ–C60 molecules to achieve the Aviram–Ratner rectifier and by modifying electronic states through azafullerene C59N molecules. The effect of the negative differential resistances can be realized by appropriately matching the molecular orbital symmetries between a cobalt phthalocyanine (CoPc) molecule and a Ni electrode. The electronic states and transport properties of single molecules, such as CoPc and melamine molecules, can be altered through manipulation or modifying molecular structures, leading to functionalized molecular devices.
Iso‐Structural Phase Transitions in BiFeO3
Authors: Scott James F.
Published: March 2010

This essay discusses recent work on bismuth ferrite, which reveals theoretically and experimentally a phase transition under stress that does not change symmetry but changes the c/a lattice constant ratio. As shown by Ishibashi, such transitions must be discontinuous and are described by free energies eighth‐order in polarization P. Such a predicted two‐step change in P is also known in potassium nitrate films.
The association between effort–reward imbalance and coronary atherosclerosis in a Chinese sample
Authors: Xu Weixian , Zhao Yiming , Guo Lijun , Guo Yanhong , Gao Wei
Published: March 2010

Background

Previous studies of job strain and coronary heart disease (CHD) have produced mixed findings. We aimed to examine the association between job stress evaluated by the effort–reward imbalance (ERI) model and coronary atherosclerosis assessed by coronary angiography in a Chinese sample.

Methods

Three‐hundred twenty participants accepting coronary angiography for the first time were enrolled in series. Job stressors were evaluated by the ERI model. The presence and severity of CHD were assessed by measuring the coronary artery stenosis (the presence of >50% luminal stenosis in one or more major coronary arteries). The association between job stressors and CHD was examined by multivariate analysis.

Results

Compared with the low‐level group, high‐level effort, overcommitment, and ERI increased CHD risk with odds ratio (OR) 2.5 (95% confidence interval (CI): 1.2–5.0), 2.5 (95% CI: 1.2–5.0), 2.4 (95% CI: 1.2–4.9), respectively, after adjustment for confounders. They were also significantly positively correlated with the complexity of coronary artery lesions, respectively. Dose–response relationships were observed.

Conclusions

ERI was associated with coronary artery lesions in a sample of Chinese workers. Longitudinal research and interventional designs are needed to confirm the mechanism and to provide evidence for the prevention of CHD. Am. J. Ind. Med. 53:655–661, 2010. © 2010 Wiley‐Liss, Inc.
The influence of sociodemographic characteristics on agreement between self‐reports and expert exposure assessments
Authors: Sembajwe Grace , Quinn Margaret , Kriebel David , Stoddard Anne , Krieger Nancy , Barbeau Elizabeth
Published: March 2010

Background

Often in exposure assessment for epidemiology, there are no highly accurate exposure data and different measurement methods are considered. The objective of this study was to use various statistical techniques to explore agreement between individual reports and expert ratings of workplace exposures in several industries and investigate the sociodemographic influences on this agreement.

Methods

A cohort of 1,282 employees at 4 industries/14 worksites answered questions on workplace physical, chemical, and psychosocial exposures over the past 12 months. Occupational hygienists constructed job exposure matrices (JEMs) based on worksite walkthrough exposure evaluations. Worker self‐reports were compared with the JEMs using multivariable analyses to explore discord.

Results

There was poor agreement between the self‐reported and expert exposure assessments, but there was evidence that agreement was modified by sociodemographic characteristics. Several characteristics including gender, age, race/ethnicity, hourly wage and nativity strongly affected the degree of discord between self‐reports and expert raters across a wide array of different exposures.

Conclusions

Agreement between exposure assessment tools may be affected by sociodemographic characteristics. This study is cross‐sectional and therefore, a snapshot of potential exposures in the workplace. Nevertheless, future studies should take into account the social contexts within which workplace exposures occur. Am. J. Ind. Med. 53:1019–1031, 2010. © 2010 Wiley‐Liss, Inc.
No association of alcohol dependence with HOMER 1 and 2 genetic variants
Authors: Preuss U.W. , Ridinger M. , Rujescu D. , Fehr C. , Koller G. , Wodarz N. , Bondy B. , Soyka M. , Wong W.M. , Zill P.
Published: March 2010

Several lines of evidence indicate that alterations of the central cortico‐accumbens glutamate pathway are involved in the development and maintenance of alcohol‐ and substance‐use disorders. The HOMER protein family is encoded by 3 genes HOMER (1–3) which are components of the excitatory postsynaptic density complex and function to modulate synaptic activity by the regulation of glutamate signaling. HOMER 1 and 2 have been reported to contribute to chronic alcohol‐induced long‐term neurochemical changes in the endogenous reward system. Data from animal models suggest a potential role of the Homer protein family in the development of alcohol and substance use. The aim of this study is to assess potential associations between HOMER 1 and 2 genetic variants in a larger sample of alcohol‐dependent individuals and unrelated controls. Five genetic variants of HOMER 1 and 3 of HOMER 2 were genotyped in a multi‐site sample of 1,923 German healthy controls and 2,039 alcohol‐dependent subjects. Neither single SNP nor haplotype analysis could detect significant associations with alcohol dependence (AD) and related phenotypes. While most of the HOMER 1 and 2 SNPs are in low‐to‐moderate linkage disequilibrium, three major haplotypes of HOMER 1 and 4 haplotypes of HOMER 2 are present in the majority of alcohol‐dependent and control subjects. In conclusion, our results suggest that single SNPs, respectively, haplotypes of the HOMER 1 and 2 genes are unlikely to play a major role in the pathophysiology of AD. © 2010 Wiley‐Liss, Inc.
Phylogenetic analysis of the fecal flora of the wild pygmy loris
Authors: Bo Xu , Zun‐xi Huang , Xiao‐yan Wang , Run‐chi Gao , Xiang‐hua Tang , Yue‐lin Mu , Yun‐Juan Yang , Hui Shi , Li‐da Zhu
Published: March 2010

The bacterial diversity in fecal samples from the wild pygmy loris was examined with a 16S rDNA clone library and restriction fragment length polymorphism analysis. The clones were classified as Firmicutes (43.1%), Proteobacteria (34.5%), Actinobacteria (5.2%), and Bacteroidetes (17.2%). The 58 different kinds of 16S rDNA sequences were classified into 16 genera and 20 uncultured bacteria. According to phylogenetic analysis, the major genera within the Proteobacteria was Pseudomonas, comprising 13.79% of the analyzed clone sequences. Many of the isolated rDNA sequences did not correspond to known microorganisms, but had high homology to uncultured clones found in human feces. Am. J. Primatol. 72:699–706, 2010. © 2010 Wiley‐Liss, Inc.
Genetic structure of native circumpolar populations based on autosomal, mitochondrial, and Y chromosome DNA markers
Authors: Rubicz Rohina , Melton Phillip E. , Spitsyn Victor , Sun Guangyun , Deka Ranjan , Crawford Michael H.
Published: March 2010

This study investigates the genetic structure of the present‐day inhabitants of Beringia in order to answer questions concerning their origins and evolution. According to recent studies, the ancestors of Native Americans paused for a time in Beringia, during which they differentiated genetically from other Asians before peopling the New World. Furthermore, the Koryaks of Kamchatka share a “ubiquitous” allele (D9S1120) with Native Americans, indicating they may have descended from the same ancestral Beringian population that gave rise to the New World founders. Our results show that a genetic barrier exists between Kamchatkans (Koryaks and Even) and Bering Island inhabitants (Aleuts, mixed Aleuts, and Russians), based on Analysis of Molecular Variance (AMOVA) and structure analysis of nine autosomal short tandem repeats (STRs). This is supported by mitochondrial DNA evidence, but not by analysis of Y chromosome markers, as recent non‐native male admixture into the region appears to have partially obscured ancient population relationships. Our study indicates that while Aleuts are descended from the original New World founders, the Koryaks are unlikely to represent a Beringian remnant of the ancestral population that gave rise to Native Americans. They are instead, like the Even, more recent arrivals to Kamchatka from interior Siberia, and the “ubiquitous” allele in Koryaks may result from recent gene flow from Chukotka. Genbank accession numbers for mtDNA sequences: GQ922935‐GQ922973. Am J Phys Anthropol 143:62–74, 2010. © 2010 Wiley‐Liss, Inc.
Proton exchange membranes for a direct methanol fuel cell based on sulfonated styrene‐(ethylene‐butylene)‐styrene/polyvinylidene fluoride blends
Authors: Seeponkai N. , Wootthikanokkhan J.
Published: March 2010

Proton‐conducting membranes for a direct methanol fuel cell, based on styrene‐(ethylene‐butylene)‐styrene (SEBS) triblock copolymer blended with polyvinylidene fluoride (PVDF), have been developed. First, the partially sulfonated SEBS with a variety of degrees of substitution was prepared by reacting the SEBS with propionyl sulfate. Then, the sulfonated SEBS was blended with PVDF at various blending ratios and fabricated by using a solution casting technique. The water uptake, proton conductivities, methanol permeabilities, and mechanical properties of the blend membranes were measured by using gravimetry, impedance analysis, gas chromatography, and tensile test, respectively. It was found that water uptake of the blend membranes increased with the sulfonated SEBS content, at the expense of their methanol resistance. The proton conductivity of the blend membranes, however, did not change linearly with the sulfonated SEBS content. This was related to poor compatibility between the two polymers in the blend membranes. However, by adding 5 wt % of poly(styrene)‐b‐poly(methyl methacrylate) block copolymer, compatibility, proton conductivity, and methanol resistance of the blend membrane increased. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Agrofillers in polypropylene composites: A relationship between the density and the mechanical properties
Authors: Moresco Mauro , Rosa Simone Maria Leal , Santos Evelise Fonseca , Nachtigall Sônia Marlí Bohrz
Published: March 2010

One of the most interesting properties of agrofilled polymer composites is their light weight. Polypropylene composites containing six different agrofillers were prepared in a mixer, and their properties were examined in terms of the density of the fillers and composites. The densities of the composites increased with the level of filler but did not show a direct relationship with the density of the fillers used. This probably happened because of the different degrees of filler densification during processing. The composites showed decreased tensile strength and increased elastic modulus with filler loads, and the specific mechanical properties showed similar trends. However, the addition of maleated polypropylene improved the tensile strength and decreased the density; this improved the specific properties of the composites filled with cane, wood, and bamboo. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Hydroxyl‐terminated poly(urethane acrylate) as a soft liner in dental applications: Synthesis and characterization
Authors: Keskin Selda , Usanmaz Ali
Published: March 2010

Hydroxyl‐terminated poly(urethane acrylate)s were synthesized for use in biomedical applications. Acrylate end capping via an interesterification reaction was successfully achieved with methacryloyl chloride addition to the hydroxyl ends of the polyurethane at low temperatures. 2,4‐Toluene diisocyanate, 1,6‐hexane diisocyanate, and methylene diphenyl diisocyanate were used as diisocyanates for urethane synthesis, and they were end‐capped with methyl methacrylate and hydroxyethyl methacrylate. The nature of the monomers that we used had an effect on the thermal and morphological properties that were interpreted in terms of the level of hydrogen bonding and the degree of phase separation. The synthesized polymers were characterized by NMR, Fourier transform infrared/attenuated total reflectance spectroscopy, differential scanning calorimetry, thermogravimetric analysis, and gel permeation chromatography. The number‐average molecular weights of the poly(urethane acrylate)s were 2500–6000 g/mol. To use the polymer as a soft‐liner material in denture applications, the residual isocyanate should not exist. In this study, we showed that a prepolymer without residual isocyanate could be synthesized. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Synthesis and characterization of curable methacrylate‐based monomers
Authors: Ghaemy Mousa , Bekhradnia Sara
Published: March 2010

The synthesis of new methacrylate‐based, curable macromonomers, 4,4′‐bis[2‐hydroxy‐3‐aminopropylmethacrylate] diphenyl ether (BHAPE) and 4,4′‐bis[2‐hydroxy‐3‐aminopropylmethacrylate] diphenyl methane (BHAPM), is reported. BHAPE and BHAPM were prepared by the reaction of glycidyl methacrylate (GMA) with 4,4′‐diaminodiphenyl ether and 4,4′‐diaminodiphenyl methane, respectively. The progress of the reaction was monitored by thin‐layer chromatography (TLC), and the structure of the monomers was characterized by Fourier transform infrared (FTIR) and 1H‐NMR spectroscopy. Thermal curing of the monomers was conducted in a differential scanning calorimeter (DSC) with peroxide as the initiator. Thermal curing of the monomers showed the highest rate at 100°C with the activation energy value in the range 80–90 kJ distilled/mol. The water absorption properties of the cured samples in water, acidic, and basic solutions were studied. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Search behavior of media professionals at an audiovisual archive: A transaction log analysis
Authors: Huurnink Bouke , Hollink Laura , van den Heuvel Wietske , de Rijke Maarten
Published: March 2010

Finding audiovisual material for reuse in new programs is an important activity for news producers, documentary makers, and other media professionals. Such professionals are typically served by an audiovisual broadcast archive. We report on a study of the transaction logs of one such archive. The analysis includes an investigation of commercial orders made by the media professionals and a characterization of sessions, queries, and the content of terms recorded in the logs. One of our key findings is that there is a strong demand for short pieces of audiovisual material in the archive. In addition, while searchers are generally able to quickly navigate to a usable audiovisual broadcast, it takes them longer to place an order when purchasing a subsection of a broadcast than when purchasing an entire broadcast. Another key finding is that queries predominantly consist of (parts of) broadcast titles and of proper names. Our observations imply that it may be beneficial to increase support for fine‐grained access to audiovisual material, for example, through manual segmentation or content‐based analysis.
Poplar as a feedstock for biofuels: A review of compositional characteristics
Authors: Sannigrahi Poulomi , Ragauskas Arthur J. , Tuskan Gerald A.
Published: March 2010

The growing demand for transportation fuels, along with concerns about the harmful effects of greenhouse gas emissions from the burning of fossil fuels, has assured a viable future for the development of alternative fuels from renewable resources, such as lignocellulosic biomass. The efficient utilization of these biomass resources is critically dependant on the in‐depth knowledge of their chemical constituents. This, together with the desired fuel properties, helps tailor the chemical and/or enzymatic processes involved in converting biomass to biofuels. Hybrid poplars are among the fastest growing temperate trees in the world and a very promising feedstock for biofuels and other value‐added products. Sequencing of the poplar genome has paved the way for tailoring new cultivars and clones optimized for biofuels production. Our objective is to review published research on the composition of the key chemical constituents of hybrid poplar species used for biofuels. Biomass yields, elemental composition, carbohydrate and lignin content and composition are some of the characteristics reviewed, with emphasis on lignin structure. Genetic modifications used to alter lignin content and composition, with the aim of improving biofuels yields, are also examined. Copyright © 2010 Society of Chemical Industry and John Wiley & Sons, Ltd
Elevated glucose induces congenital heart defects by altering the expression of tbx5, tbx20, and has2 in developing zebrafish embryos
Authors: Liang Jintao , Gui Yonghao , Wang Wei , Gao Shan , Li Jing , Song Houyan
Published: March 2010

BACKGROUND:

Maternal diabetes increases the risk of congenital heart defects in infants, and hyperglycemia acts as a major teratogen. Multiple steps of cardiac development, including endocardial cushion morphogenesis and development of neural crest cells, are challenged under elevated glucose conditions. However, the direct effect of hyperglycemia on embryo heart organogenesis remains to be investigated.

METHODS:

Zebrafish embryos in different stages were exposed to D‐glucose for 12 or 24 hr to determine the sensitive window during early heart development. In the subsequent study, 6 hr post‐fertilization embryos were treated with either 25 mmol/liter D‐glucose or L‐glucose for 24 hr. The expression of genes was analyzed by whole‐mount in situ hybridization.

RESULTS:

The highest incidence of cardiac malformations was found during 6–30 hpf exposure periods. After 24 hr exposure, D‐glucose–treated embryos exhibited significant developmental delay and diverse cardiac malformations, but embryos exposed to L‐glucose showed no apparent phenotype. Further investigation of the origin of heart defects showed that cardiac looping was affected earliest, while the specification of cardiac progenitors and heart tube assembly were complete. Moreover, the expression patterns of tbx5, tbx20, and has2 were altered in the defective hearts.

CONCLUSIONS:

Our data demonstrate that elevated glucose alone induces cardiac defects in zebrafish embryos by altering the expression pattern of tbx5, tbx20, and has2 in the heart. We also show the first evidence that cardiac looping is affected earliest during heart organogenesis. These research results are important for devising preventive and therapeutic strategies aimed at reducing the occurrence of congenital heart defects in diabetic pregnancy. Birth Defects Research (Part A) 2010. © 2010 Wiley‐Liss, Inc.
A possible association of periodontal infectious diseases in pregnant women with isolated orofacial clefts in their children: A population‐based case‐control study
Authors: Bánhidy Ferenc , Ács Nándor , Puhó Erzsébet H. , Czeizel Andrew E.
Published: March 2010

BACKGROUND:

The aim of the study was to check the association of maternal periodontal infectious disease (MPID) during pregnancy and the possible risk for birth outcomes, mainly structural birth defects: congenital abnormalities (CAs) in their children.

METHODS:

The population‐based data set of the Hungarian Case‐Control Surveillance System of Congenital Abnormalities, 1980–1996, was evaluated. The occurrence of medically recorded MPID in the prenatal maternity logbook was compared in 22,843 cases with different CAs and 38,151 matched controls without defects.

RESULTS:

Twenty‐one case mothers who had offspring with a CA (case group) and 17 pregnant women who delivered newborn infants without a CA (control group) had an MPID. However, of 21 cases, 6 had isolated cleft lip ± palate (OR with 95% CI: 10.7, 4.2–27.3), and 2 were affected with isolated cleft palate (7.9, 1.8–34.2). Of these 8 cases, 6 had mothers with the exposure of MPID in the critical period of these orofacial clefts, 7 mothers were visited at home, and 6 were smokers during pregnancy.

CONCLUSIONS:

The unexpected findings of the study showed a strong association of MPID during pregnancy with a higher risk of isolated orofacial clefts in their children. Birth Defects Research (Part A) 2010. © 2010 Wiley‐Liss, Inc.
Basement membranes in development and disease
Authors: Wiradjaja Fenny , DiTommaso Tia , Smyth Ian
Published: March 2010

Basement membranes (BMs) are specializations of the extracellular matrix that act as key mediators of development and disease. Their sheet like protein matrices typically serve to separate epithelial or endothelial cell layers from underlying mesenchymal tissues, providing both a biophysical support to overlying tissue as well as a hub to promote and regulate cell–cell and cell–protein interactions. In the latter context, the BM is increasingly being recognized as a mediator of growth factor interactions during development. In this review, we discuss recent findings regarding the structure of the BM and its roles in mediating the normal development of the embryo, and we examine congenital diseases affecting the BM which impact embryonic development and health in later life. Birth Defects Research (Part C) 90:8–31, 2010. © 2010 Wiley‐Liss, Inc.
Therapeutic potential of the immunomodulatory activities of adult mesenchymal stem cells
Authors: Petrie Aronin Caren E. , Tuan Rocky S.
Published: March 2010

Adult mesenchymal stem cells (MSCs) include a select population of resident cells within adult tissues, which retain the ability to differentiate along several tissue‐specific lineages under defined media conditions and have finite expansion potential in vitro. These adult progenitor populations have been identified in various tissues, but it remains unclear exactly what role both transplanted and native MSCs play in processes of disease and regeneration. Interestingly, increasing evidence reveals a unique antiinflammatory immunomodulatory phenotype shared among this population, lending support to the idea that MSCs play a central role in early tissue remodeling responses where a controlled inflammatory response is required. However, additional evidence suggests that MSCs may not retain infinite immune privilege and that the context with which these cells are introduced in vivo may influence their immune phenotype. Therefore, understanding this dynamic microenvironment in which MSCs participate in complex feedback loops acting upon and being influenced by a plethora of secreted cytokines, extracellular matrix molecules, and fragments will be critical to elucidating the role of MSCs in the intertwined processes of immunomodulation and tissue repair. Birth Defects Research (Part C) 90:67–74, 2010. © 2010 Wiley‐Liss, Inc.
Mammalian synthetic biology – from tools to therapies
Authors: Aubel Dominique , Fussenegger Martin
Published: March 2010

Mammalian synthetic biology holds the promise of providing novel therapeutic strategies, and the first success stories are beginning to be reported. Here we focus on the latest generation of mammalian transgene control devices, highlight state‐of‐the‐art synthetic gene network design, and cover prototype therapeutic circuits. These will have an impact on future gene‐ and cell‐based therapies and help bring drug discovery into a new era. The inventory of biological parts that are essential for life on this planet is becoming increasingly complete. The postgenomic era has provided encyclopedic information on gene‐function correlations and systems biology is now delivering comprehensive details on the dynamics of biochemical reaction networks in living organisms. The time has come to reassemble these catalogued items and design new biological devices and systems with novel and useful functionality in a rational and systematic manner. This is the premise of synthetic biology, a constructive systems biology discipline likely to become the life science revolution of the 21st century.
Identifying co-morbidity in surgical patients using administrative data with the Royal College of Surgeons Charlson Score
Authors: Armitage J N , van der Meulen J H
Published: March 2010

Background

Surgical outcomes are influenced by co-morbidity. The Royal College of Surgeons (RCS) Co-morbidity Consensus Group was convened to improve existing instruments that identify co-morbidity in International Classification of Diseases tenth revision administrative data.

Methods

The RCS Charlson Score was developed using a coding philosophy that enhances international transferability and avoids misclassifying complications as co-morbidity. The score was validated in English Hospital Episode Statistics data for abdominal aortic aneurysm (AAA) repair, aortic valve replacement, total hip replacement and transurethral prostate resection.

Results

With exception of AAA, patients with co-morbidity were older and more likely to be admitted as an emergency than those without. All patients with co-morbidity stayed longer in hospital, required more augmented care, and had higher in-hospital and 1-year mortality rates. Multivariable prognostic models incorporating the RCS Charlson Score had better discriminatory power than those that relied only on age, sex, admission method (elective or emergency) and number of emergency admissions in the preceding year.

Conclusion

The RCS Charlson Score identifies co-morbidity in surgical patients in England at least as well as existing instruments. Given its explicit coding philosophy, it may be used as a co-morbidity scoring instrument for international comparisons.
Obesity and gastrointestinal cancer
Authors: Donohoe C L , Pidgeon G P , Lysaght J , Reynolds J V
Published: March 2010

Background

There is emerging evidence of a strong association between obesity and gastrointestinal cancer. This review summarizes the evidence from an epidemiological and pathophysiological perspective.

Methods

Relevant medical literature was identified from searches of PubMed and references cited in appropriate articles were identified. Selection of articles was based on peer review, journal and relevance.

Results

Numerous epidemiological studies consistently identified an increased risk of developing oesophageal adenocarcinoma and colorectal carcinoma in the obese. The association between obesity and other gastrointestinal malignancies was less robust. Sex seems important with respect to cancer risk. Adipose tissue, particularly viscerally located fat, is metabolically active and exerts systemic endocrine effects. Putative pathophysiological mechanisms linking obesity and carcinogenesis include the insulin-like growth factor axis, adipocytokines and sex steroids.

Conclusion

A better understanding of the mechanisms that link obesity and cancer may uncover targets for intervention. Tackling obesity may result in a reduction in the incidence in addition to mortality of certain cancers in future.
Chromosomal integration of a synthetic expression control sequence achieves poly‐γ‐glutamate production in a Bacillus subtilis strain
Authors: Yeh Chuan‐Mei , Wang Jyh‐Perng , Lo Shih‐Ching , Chan Wen‐Chia , Lin Ming‐Yi
Published: March 2010

Poly‐γ‐glutamate (γ‐PGA) has applications in food, medical, cosmetic, animal feed, and wastewater industries. Bacillus subtilis DB430, which possesses the γ‐PGA synthesis ywsC‐ywtAB genes in its chromosome, cannot produce γ‐PGA. An efficient synthetic expression control sequence (SECS) was introduced into the upstream region of the ywtABC genes, and this resulted in γ‐PGA‐producing B. subtilis mutant strains. Mutant B. subtilis PGA6‐2 stably produces high levels of γ‐PGA in medium A without supplementation of extra glutamic acid or ammonium chloride. The mutant B. subtilis PGA 6‐2 is not only a γ‐PGA producer, but it is also a candidate for the genetic and metabolic engineering of γ‐PGA production. © 2010 American Institute of Chemical Engineers Biotechnol. Prog., 2010
13C‐metabolic flux analysis for batch culture of Escherichia coli and its pyk and pgi gene knockout mutants based on mass isotopomer distribution of intracellular metabolites
Authors: Toya Yoshihiro , Ishii Nobuyoshi , Nakahigashi Kenji , Hirasawa Takashi , Soga Tomoyoshi , Tomita Masaru , Shimizu Kazuyuki
Published: March 2010

Since most bio‐production processes are conducted in a batch or fed‐batch manner, the evaluation of metabolism with respect to time is highly desirable. Toward this aim, we applied 13C‐metabolic flux analysis to nonstationary conditions by measuring the mass isotopomer distribution of intracellular metabolites. We performed our analysis on batch cultures of wild‐type Escherichia coli, as well as on Pyk and Pgi mutants, obtained the fluxes and metabolite concentrations as a function of time. Our results for the wild‐type indicated that the TCA cycle flux tended to increase during growth on glucose. Following glucose exhaustion, cells controlled the branch ratio between the glyoxylate pathway and the TCA cycle, depending on the availability of acetate. In the Pyk mutant, the concentrations of glycolytic intermediates changed drastically over time due to the dumping and feedback inhibition caused by PEP accumulation. Nevertheless, the flux distribution and free amino acid concentrations changed little. The growth rate and the fluxes remained constant in the Pgi mutant and the glucose‐6‐phosphate dehydrogenase reaction was the rate‐limiting step. The measured fluxes were compared with those predicted by flux balance analysis using maximization of biomass yield or ATP production. Our findings indicate that the objective function of biosynthesis became less important as time proceeds on glucose in the wild‐type, while it remained highly important in the Pyk mutant. Furthermore, ATP production was the primary objective function in the Pgi mutant. This study demonstrates how cells adjust their metabolism in response to environmental changes and/or genetic perturbations in the batch cultivation. © 2010 American Institute of Chemical Engineers Biotechnol. Prog., 2010
Removal of heavy metals from water effluents using supermacroporous metal chelating cryogels
Authors: Önnby Linda , Giorgi Camilla , Plieva Fatima M. , Mattiasson Bo
Published: March 2010

Applications of IDA in, for example, immobilized metal ion affinity chromatography for purification of His‐tagged proteins are well recognized. The use of IDA as an efficient chelating adsorbent for environmental separations, that is, for the capture of heavy metals, is not studied. Adsorbents based on supermacroporous gels (cryogels) bearing metal chelating functionalities (IDA residues and ligand derived from derivatization of epoxy‐cryogel with tris(2‐aminoethyl)amine followed by the treatment with bromoacetic acid (defined as TBA ligand)) have been prepared and evaluated on capture of heavy metal ions. The cryogels were prepared in plastic carriers, resulting in desired mechanical stability and named as macroporous gel particles (MGPs). Sorption and desorption experiments for different metals (Cu2+, Zn2+, Cd2+, and Ni2+ with IDA adsorbent and Cu2+ and Zn2+ with TBA adsorbent) were carried out in batch and monolithic modes, respectively. Obtained capacities with Cu2+ were 74 μmol/mL (TBA) and 19 μmol/mL gel (IDA). The metal removal was higher for pH values between pH 3 and 5. Both adsorbents showed improved sorption at lower temperatures (10°C) than at higher (40°C) and the adsorption significantly dropped for the TBA adsorbent and Zn2+ at 40°C. Desorption of Cu2+ by using 1 M HCl and 0.1 M EDTA was successful for the IDA adsorbent whereas the desorption with the TBA adsorbent needs further attention. The result of this work has demonstrated that MGPs are potential treatment alternatives within the field of environmental separations and the removal of heavy metals from water effluents. © 2010 American Institute of Chemical Engineers Biotechnol. Prog., 2010
Substrate Conformations Set the Rate of Enzymatic Acrylation by Lipases
Authors: Syrén Per‐Olof , Hult Karl
Published: March 2010

Acrylates represent a class of α,β‐unsaturated compounds of high industrial importance. We investigated the influence of substrate conformations on the experimentally determined reaction rates of the enzyme‐catalysed transacylation of methyl acrylate and derivatives by ab initio DFT B3LYP calculations and molecular dynamics simulations. The results supported a least‐motion mechanism upon the sp2 to sp3 substrate transition to reach the transition state in the enzyme active site. This was in accordance with our hypothesis that acrylates form productive transition states from their low‐energy s‐sis/s‐trans conformations. Apparent kcat values were measured for Candida antarctica lipase B (CALB), Humicola insolens cutinase and Rhizomucor miehei lipase and were compared to results from computer simulations. More potent enzymes for acryltransfer, such as the CALB mutant V190A and acrylates with higher turnover numbers, showed elevated populations of productive transition states.
Use of mechanical assist during high‐risk PCI and STEMI with cardiogenic shock
Authors: Cyrus Tillmann , Mathews Santhosh J. , Lasala John M.
Published: March 2010

Infarct size may be reduced by left ventricular unloading after ST‐segment elevation MI (STEMI) in addition to reperfusion therapy. Likewise, high‐risk percutaneous coronary intervention (PCI) may benefit from periprocedural support especially in patients with low cardiac output at baseline or when periprocedural hemodynamic deterioration is anticipated. Traditionally, intraaortic balloon‐pumps have been used in acute MI with cardiogenic shock. As this modality has limited hemodynamic benefits, new developments have focused on active hemodynamic assist devices. These devices actively unload the left ventricle increasing cardiac output by 2.5–5 L/min and are increasingly easier to implant and monitor. Thus, interventional cardiologists will be able to offer a safer more effective alternative to an increasing patient population with complex cardiac conditions and high‐risk PCI. © 2010 Wiley‐Liss, Inc.
Oral antiplatelet therapy in PCI patients
Authors: Sharma Samin K.
Published: March 2010

The use of percutaneous coronary intervention (PCI) in the treatment of obstructive coronary artery disease has expanded rapidly in the past decade. Despite the extensive technological advancements in the field, pharmacotherapy has remained a cornerstone in the overall treatment strategy. Oral antiplatelet therapy has become an essential component of therapy with acute coronary syndromes and in PCI by improving clinical outcomes. This article reviews the antiplatelet options for patients undergoing PCI, including aspirin, ADP receptor blockers, and glycoprotein IIb/IIIa inhibitors. © 2010 Wiley‐Liss, Inc.
Conclusion
Authors: Lasala John M. , Mehran Roxana , Moses Jeffrey W. , Popma Jeffrey J. , Reiner Jonathan S. , Sharma Samin K. , Vetrovec George W.
Published: March 2010

A panel of leaders in the field of interventional cardiology convened to discuss the evidence‐based management of patients undergoing percutaneous coronary intervention (PCI). The articles in this supplement are based on individual presentations given during the panel meeting. Following are key points of the panel's discussion and areas that the panel has indicated warrant further study. © 2010 Wiley‐Liss, Inc.
Alcohol septal ablation after myomectomy failure solutions for unusual cases
Authors: Cano Manuel Nicolas , Fortunato de Cano Silvia Judith , Sousa J. Eduardo M.R.
Published: March 2010

We report an eight‐year‐old child presented with classical features of Hypertrophic Obstructive Cardiomyopathy and with New York Heart Association (NYHA) class III symptoms, eight months after Myectomy and refractory to medical treatment. Cardiac transplantation was indicated due to the severity of symptoms. But the Lymphocyte Reaction Test showed almost 100% reaction of antibodies, and the surgeons rejected the heart transplantation for fear of hyperacute rejection. Then an Alcohol Septal Ablation (ASA) was proposed, which was successfully performed on August 17, 2005. The post‐extrasystolic gradient was reduced from 160 to 60 mm Hg immediately and no other complications were seen. The child is being followed since then and echocardiography changes include a further reduction of septum thickness and gradient (P = 0.001), and important symptoms relieved after 3.5 years of follow up. ASA may be an option to be considered in children with critical Hypertrophic Obstructive Cardiomyopathy in NYHA functional class III/IV, when other methods of treatment failed. © 2010 Wiley‐Liss, Inc.
Angiojet rheolytic thrombectomy in infants following cardiac surgery
Authors: Fleming Gregory A. , Khan Muhammed , Janssen Dana , Doyle Thomas
Published: March 2010

Objectives: To present our experience with the Angiojet thrombectomy system for percutaneous thrombectomy in infants following cardiac surgery. Background: Arterial and venous thrombosis after pediatric cardiac surgery is life threatening, particularly in infants. The best method for treating these patients has not been determined. Angiojet rheolytic thrombectomy (Possis Medical, Minneapolis, MN) is a percutaneous method of thrombus removal with proven safety and efficacy in adults. Methods: We reviewed the medical records and angiograms of all procedures in which Angiojet thrombectomy was used in infants following cardiac surgery at our institution during the years 2005 through 2007. Results: Ten procedures were performed in eight infants. The procedure was performed a mean of 23 days from surgery. The mean age was 74 days with a mean weight of 4.3 kg. All patients had life or limb threatening thrombosis. Indications for thrombectomy included severe cyanosis, chronic pleural effusions secondary to extensive venous thrombosis, and acute iliac artery thrombosis. Thrombus was evacuated from pulmonary arteries in four patients, systemic veins in two patients, a surgical aorto‐pulmonary shunt in two patients, and an iliac artery in one patient. Balloon angioplasty following thrombectomy was performed in eight procedures (80%), and stents were placed in addition to angioplasty in two procedures. All patients had significant improvement in flow across the affected area. There was one major complication and three minor complications with no procedural‐related deaths. Survival to discharge from the hospital was 62.5%. Conclusion: Angiojet thrombectomy is an effective treatment for life‐threatening postoperative thrombosis in infants following cardiac surgery. © 2010 Wiley‐Liss, Inc.
Retrograde left‐ventricular hemodynamic assessment of mechanical aortic and mitral valve gradients using a high‐fidelity pressure wire: A case series
Authors: Owan Theophilus E. , Reddy Bhavananda T. , Michaels Andrew D.
Published: March 2010

Noninvasive assessment of mechanical heart valve function with echocardiography is challenging. There are important safety issues when considering placing a standard catheter across a mechanical valve with for invasive hemodynamic measurements. The feasibility of using a high‐fidelity micromanometer coronary pressure guide wire to assess hemodynamics across mechanical valves has been reported. Although this method appears feasible, safe, and free of major complication, its application and utility remains obscure and underappreciated. We report a series of two patients with mitral and aortic (St. Jude and Björk‐Shiley) mechanical valves in which we successfully used this pressure wire technique to assess valvular function in patients evaluated for repeat surgical valve replacement. We include the first report of this guide wire technique to assess hemodynamics across a Björk–Shiley single‐tilting disk valve. © 2010 Wiley‐Liss, Inc.
Shunt reduction with a fenestrated Amplatzer device
Authors: Kretschmar Oliver , Sglimbea Anca , Corti Roberto , Knirsch Walter
Published: March 2010

Background: In specific high‐risk patients with congenital heart disease (CHD), a complete closure of an intracardiac defect/shunt is not possible for a variety of reasons. We report our experiences with an interventional approach for shunt‐reduction using various modifications of a self‐fabricated Amplatzer device in our institution. Methods: Retrospective analysis of patients with CHD having received an interventional partial shunt occlusion since 09/2005. Results: Five patients, mean age 18.6(3.4–66) years, mean weight 36.4(14–102) kg, have been treated. In three patients (3.4, 3.9, 66 years) with an atrial septal defect (ASD) and a restrictive left ventricle (LV) (n = 1) or pulmonary arterial hypertension (PAH) (n = 2), respectively, an Amplatzer Septal Occluder (ASO) with a predilated (n = 2) or a presutured (n = 1) central hole was implanted. After successful immediate volume release in all, the balloon‐dilated holes closed spontaneously during mid‐term follow‐up, pulmonary artery (PA) pressure and LV function remained normal. Two patients (2.7 and 17 years) with a Fontan circulation and severe cyanosis (saturation ≤80%) due to a large fenestration and elevated PA pressures received a partial occlusion of their shunt by implanting a centrally stented ASO or Amplatzer Vascular plug. After a follow‐up of 31 and 39 months both stents remained patent under oral anticoagulation, oxygen saturation remained >85% with PA pressures unchanged, and both patients were in good clinical conditions. Conclusions: In patients with an ASD and significant PAH and/or restrictive LV physiology as well as in Fontan patients with a large surgically created fenestration but failing Fontan circulation, a partial closure with a self‐fenestrated Amplatzer device can be a feasible and successful therapeutic option. Balloon‐dilated fenestrations in the Amplatzer device tend to close spontaneously during follow‐up. Nonresorbable sutures or stenting can ensure patency of the created holes. © 2010 Wiley‐Liss, Inc.