bluuebunny/crossref_metadata_2025 huggingface dataset:
An Ertapenem-Resistant Extended-Spectrum-β-Lactamase-Producing
Klebsiella pneumoniae
Clone Carries a Novel OmpK36 Porin Variant
Authors: García-Fernández Aurora , Miriagou Vivi , Papagiannitsis Costas C. , Giordano Alessandra , Venditti Mario , Mancini Carlo , Carattoli Alessandra
Published: July 2010

Carbapenem-resistant
Klebsiella pneumoniae
caused an outbreak in a hospital in Rome, Italy. The clinical isolates were tested by antimicrobial susceptibility testing, pulsed-field gel electrophoresis, multilocus sequence typing, plasmid typing, and β-lactamase identification. The OmpK35 and OmpK36 porins were analyzed by SDS-PAGE, and their genes were amplified and sequenced. Complementation experiments were performed using a recombinant unrelated
ompK36
gene. An ertapenem-resistant and imipenem- and meropenem-susceptible clone was identified and assigned to the sequence type 37 lineage by MLST; it carried SHV-12 and CTX-M-15 ESBLs, did not produce the OmpK35 due to a nonsense mutation, and expressed a novel OmpK36 variant (OmpK36V). This variant showed two additional amino acids located within the L3 internal loop, one of the highly conserved domains of the protein. Two isolates of the same clone also exhibited resistance to imipenem and meropenem, due to the loss of OmpK36 expression by a nonsense mutation occurring in the
ompK36V
variant gene. These were the first carbapenem-resistant
K. pneumoniae
isolates identified within the hospital. Screening for the
ompK36V
gene of unrelated
K. pneumoniae
isolates derived from patients from 2006 to 2009 demonstrated the high frequency of this gene variant as well as its association with ertapenem resistance, reduced susceptibility to meropenem, and susceptibility to imipenem.
Lersivirine, a Nonnucleoside Reverse Transcriptase Inhibitor with Activity against Drug-Resistant Human Immunodeficiency Virus Type 1
Authors: Corbau Romuald , Mori Julie , Phillips Chris , Fishburn Lesley , Martin Alex , Mowbray Charles , Panton Wendy , Smith-Burchnell Caroline , Thornberry Adele , Ringrose Heather , Knöchel Thorsten , Irving Steve , Westby Mike , Wood Anthony , Perros Manos
Published: July 2010

The nonnucleoside reverse transcriptase inhibitors (NNRTIs) are key components of highly active antiretroviral therapy (HAART) for the treatment of human immunodeficiency virus type 1 (HIV-1). A major problem with the first approved NNRTIs was the emergence of mutations in the HIV-1 reverse transcriptase (RT), in particular K103N and Y181C, which led to resistance to the entire class. We adopted an iterative strategy to synthesize and test small molecule inhibitors from a chemical series of pyrazoles against wild-type (wt) RT and the most prevalent NNRTI-resistant mutants. The emerging candidate, lersivirine (UK-453,061), binds the RT enzyme in a novel way (resulting in a unique resistance profile), inhibits over 60% of viruses bearing key RT mutations, with 50% effective concentrations (EC50s) within 10-fold of those for wt viruses, and has excellent selectivity against a range of human targets. Altogether lersivirine is a highly potent and selective NNRTI, with excellent efficacy against NNRTI-resistant viruses.
Short Cationic Antimicrobial Peptides Interact with ATP
Authors: Hilpert Kai , McLeod Brett , Yu Jessie , Elliott Melissa R. , Rautenbach Marina , Ruden Serge , Bürck Jochen , Muhle-Goll Claudia , Ulrich Anne S. , Keller Sandro , Hancock Robert E. W.
Published: July 2010

The mode of action of short, nonhelical antimicrobial peptides is still not well understood. Here we show that these peptides interact with ATP and directly inhibit the actions of certain ATP-dependent enzymes, such as firefly luciferase, DnaK, and DNA polymerase. α-Helical and planar or circular antimicrobial peptides did not show such interaction with ATP.
Silver Coordination Polymers for Prevention of Implant Infection: Thiol Interaction, Impact on Respiratory Chain Enzymes, and Hydroxyl Radical Induction
Authors: Gordon Oliver , Vig Slenters Tünde , Brunetto Priscilla S. , Villaruz Amer E. , Sturdevant Daniel E. , Otto Michael , Landmann Regine , Fromm Katharina M.
Published: July 2010

Prosthetic joint replacements are used increasingly to alleviate pain and improve mobility of the progressively older and more obese population. Implant infection occurs in about 5% of patients and entails significant morbidity and high social costs. It is most often caused by staphylococci, which are introduced perioperatively. They are a source of prolonged seeding and difficult to treat due to antibiotic resistance; therefore, infection prevention by prosthesis coating with nonantibiotic-type anti-infective substances is indicated. A renewed interest in topically used silver has fostered development of silver nanoparticles, which, however, present a potential health hazard. Here we present new silver coordination polymer networks with tailored physical and chemical properties as nanostructured coatings on metallic implant substrates. These compounds exhibited strong biofilm sugar-independent bactericidal activity on
in vitro
-grown biofilms and prevented murine S
taphylococcus epidermidis
implant infection
in vivo
with slow release of silver ions and limited transient leukocyte cytotoxicity. Furthermore, we describe the biochemical and molecular mechanisms of silver ion action by gene screening and by targeting cell metabolism of
S. epidermidis
at different levels. We demonstrate that silver ions inactivate enzymes by binding sulfhydryl (thiol) groups in amino acids and promote the release of iron with subsequent hydroxyl radical formation by an indirect mechanism likely mediated by reactive oxygen species. This is the first report investigating the global metabolic effects of silver in the context of a therapeutic application. We anticipate that the compounds presented here open a new treatment field with a high medical impact.
End-of-life decisions as bedside rationing. An ethical analysis of life support restrictions in an Indian neonatal unit
Authors: Miljeteig I , Johansson K A , Sayeed S A , Norheim O F
Published: July 2010

Introduction

Hundreds of thousands of premature neonates born in low-income countries are implicitly denied treatment each year. Studies from India show that treatment is rationed even for neonates born at 32 gestational age weeks (GAW), and multiple external factors influence treatment decisions. Is withholding of life-saving treatment for children born between 28 and 32 GAW acceptable from an ethical perspective?

Method

A seven-step impartial ethical analysis, including outcome analysis of four accepted priority criteria: severity of disease, treatment effect, cost effectiveness and evidence for neonates born at 28 and 32 GAW.

Results

The ethical analysis sketches out two possibilities: (a) It is not ethically permissible to limit treatment to neonates below 32 GAW when assigning high weight to health maximisation and overall health equality. Neonates below 32 GAW score high on severity of disease and efficiency and cost-effectiveness of treatment if one gives full weight to early years of a newborn life. It is in the child's best interest to be treated. (b) It can be considered ethically permissible if high weight is assigned to reducing inequality of welfare and maximising overall welfare and/or not granting full weight to early years of newborns is considered acceptable. From an equity-motivated health and welfare perspective, we would not accept (b), as it relies on accepting the lack of proper welfare policies for the poor and disabled in India.

Conclusion

Explicit priority processes in India for financing neonatal care are needed. If premature neonates are perceived as worth less than other patient groups, the reasons should be explored among a broad range of stakeholders.
Normative consent and presumed consent for organ donation: a critique
Authors: Potts Michael , Verheijde Joseph L , Rady Mohamed Y , Evans David W
Published: July 2010

Ben Saunders claims that actual consent is not necessary for organ donation due to ‘normative consent’, a concept he borrows from David Estlund. Combining normative consent with Peter Singer's ‘greater moral evil principle’, Saunders argues that it is immoral for an individual to refuse consent to donate his or her organs. If a presumed consent policy were thus adopted, it would be morally legitimate to remove organs from individuals whose wishes concerning donation are not known. This paper disputes Saunders' arguments. First, if death caused by the absence of organ transplant is the operational premise, then, there is nothing of comparable moral precedence under which a person is not obligated to donate. Saunders' use of Singer's principle produces a duty to donate in almost all circumstances. However, this premise is based on a flawed interpretation of cause and effect between organ availability and death. Second, given growing moral and scientific agreement that the organ donors in heart-beating and non-heart-beating procurement protocols are not dead when their organs are surgically removed, it is not at all clear that people have a duty to consent to their lives being taken for their organs. Third, Saunders' claim that there can be good reasons for refusing consent clashes with his claim that there is a moral obligation for everyone to donate their organs. Saunders' argument is more consistent with a conclusion of ‘mandatory consent’. Finally, it is argued that Saunders' policy, if put into place, would be totalitarian in scope and would therefore be inconsistent with the freedom required for a democratic society.
Preparing computer science students for the robotics revolution
Authors: Touretzky David S.
Published: July 2010

Robotics will inspire dramatic changes in the CS curriculum.
Has China caught up in IT?
Authors: Gao Ping , Yu Jiang
Published: July 2010

An assessment of the relative achievements in IT infrastructure, firms, and innovation in China.
An interview with Edsger W. Dijkstra
Authors: Frana Philip L. , Misa Thomas J.
Published: July 2010

The computer science luminary, in one of his last interviews before his death in 2002, reflects on a programmer's life.
Seven principles for selecting software packages
Authors: Damsgaard Jan , Karlsbjerg Jan
Published: July 2010

Everything you always wanted to know but were afraid to ask about the decision-making process.
The Singularity system
Authors: Larus James , Hunt Galen
Published: July 2010

Safe, modern programming languages let Microsoft rethink the architectural trade-offs in its experimental operating system.
Predicting the popularity of online content
Authors: Szabo Gabor , Huberman Bernardo A.
Published: July 2010

Early patterns of Digg diggs and YouTube views reflect long-term user interest.
On Detecting Data Flow Errors in Workflows
Authors: Meda Hema S. , Sen Anup Kumar , Bagchi Amitava
Published: July 2010

When designing a business workflow, it is customary practice to create the control flow structure first and to ensure its correctness. Information about the flow of data is introduced subsequently into the workflow and its correctness is independently verified. Improper specification of data requirements of tasks and XOR splits can cause problems such as wrong branching at XOR splits and the failure of tasks to execute. Here we present a graph traversal algorithm called GTforDF for detecting data flow errors in both nested and unstructured workflows, and illustrate its operation on realistic examples. Two of these have interconnected loops and are free of control flow errors, and the third one is an unstructured loop-free workflow. Our approach extends and generalizes data flow verification methods that have been recently proposed. It also makes use of the concept of corresponding pairs lately introduced in control flow verification. It thus has the potential for development into a unified algorithmic procedure for the concurrent detection of control flow and data flow errors. The correctness of the algorithm has been proved theoretically. It has also been tested experimentally on many examples.
Differential RAID
Authors: Balakrishnan Mahesh , Kadav Asim , Prabhakaran Vijayan , Malkhi Dahlia
Published: July 2010

SSDs exhibit very different failure characteristics compared to hard drives. In particular, the bit error rate (BER) of an SSD climbs as it receives more writes. As a result, RAID arrays composed from SSDs are subject to correlated failures. By balancing writes evenly across the array, RAID schemes can wear out devices at similar times. When a device in the array fails towards the end of its lifetime, the high BER of the remaining devices can result in data loss. We propose Diff-RAID, a parity-based redundancy solution that creates an age differential in an array of SSDs. Diff-RAID distributes parity blocks unevenly across the array, leveraging their higher update rate to age devices at different rates. To maintain this age differential when old devices are replaced by new ones, Diff-RAID reshuffles the parity distribution on each drive replacement. We evaluate Diff-RAID's reliability by using real BER data from 12 flash chips on a simulator and show that it is more reliable than RAID-5, in some cases by multiple orders of magnitude. We also evaluate Diff-RAID's performance using a software implementation on a 5-device array of 80 GB Intel X25-M SSDs and show that it offers a trade-off between throughput and reliability.
A strategy to emulate NOR flash with NAND flash
Authors: Chang Yuan-Hao , Lin Jian-Hong , Hsieh Jen-Wei , Kuo Tei-Wei
Published: July 2010

This work is motivated by a strong market demand for the replacement of NOR flash memory with NAND flash memory to cut down the cost of many embedded-system designs, such as mobile phones. Different from LRU-related caching or buffering studies, we are interested in prediction-based prefetching based on given execution traces of application executions. An implementation strategy is proposed for the storage of the prefetching information with limited SRAM and run-time overheads. An efficient prediction procedure is presented based on information extracted from application executions to reduce the performance gap between NAND flash memory and NOR flash memory in reads. With the behavior of a target application extracted from a set of collected traces, we show that data access to NOR flash memory can respond effectively over the proposed implementation.
SOPA
Authors: Wang Yang , Shu Jiwu , Zhang Guangyan , Xue Wei , Zheng Weimin
Published: July 2010

With the development of storage technology and applications, new caching policies are continuously being introduced. It becomes increasingly important for storage systems to be able to select the matched caching policy dynamically under varying workloads. This article proposes SOPA, a cache framework to adaptively select the matched policy and perform policy switches in storage systems. SOPA encapsulates the functions of a caching policy into a module, and enables online policy switching by policy reconstruction. SOPA then selects the policy matched with the workload dynamically by collecting and analyzing access traces. To reduce the decision-making cost, SOPA proposes an asynchronous decision making process. The simulation experiments show that no single caching policy performed well under all of the different workloads. With SOPA, a storage system could select the appropriate policy for different workloads. The real-system evaluation results show that SOPA reduced the average response time by up to 20.3% and 11.9% compared with LRU and ARC, respectively.
Fluorescent Proteins and Their Applications in Imaging Living Cells and Tissues
Authors: Chudakov Dmitriy M. , Matz Mikhail V. , Lukyanov Sergey , Lukyanov Konstantin A.
Published: July 2010

Green fluorescent protein (GFP) from the jellyfish Aequorea victoria and its homologs from diverse marine animals are widely used as universal genetically encoded fluorescent labels. Many laboratories have focused their efforts on identification and development of fluorescent proteins with novel characteristics and enhanced properties, resulting in a powerful toolkit for visualization of structural organization and dynamic processes in living cells and organisms. The diversity of currently available fluorescent proteins covers nearly the entire visible spectrum, providing numerous alternative possibilities for multicolor labeling and studies of protein interactions. Photoactivatable fluorescent proteins enable tracking of photolabeled molecules and cells in space and time and can also be used for super-resolution imaging. Genetically encoded sensors make it possible to monitor the activity of enzymes and the concentrations of various analytes. Fast-maturing fluorescent proteins, cell clocks, and timers further expand the options for real time studies in living tissues. Here we focus on the structure, evolution, and function of GFP-like proteins and their numerous applications for in vivo imaging, with particular attention to recent techniques.
The Role of Peroxisome Proliferator-Activated Receptor β/δ on the Inflammatory Basis of Metabolic Disease
Authors: Coll Teresa , Barroso Emma , Álvarez-Guardia David , Serrano Lucía , Salvadó Laia , Merlos Manuel , Palomer Xavier , Vázquez-Carrera Manuel
Published: July 2010

The pathophysiology underlying several metabolic diseases, such as obesity, type 2 diabetes mellitus, and atherosclerosis, involves a state of chronic low-level inflammation. Evidence is now emerging that the nuclear receptor Peroxisome Proliferator-Activated Receptor (PPAR)β/δameliorates these pathologies partly through its anti-inflammatory effects. PPARβ/δactivation prevents the production of inflammatory cytokines by adipocytes, and it is involved in the acquisition of the anti-inflammatory phenotype of macrophages infiltrated in adipose tissue. Furthermore, PPARβ/δligands prevent fatty acid-induced inflammation in skeletal muscle cells, avoid the development of cardiac hypertrophy, and suppress macrophage-derived inflammation in atherosclerosis. These data are promising and suggest that PPARβ/δligands may become a therapeutic option for preventing the inflammatory basis of metabolic diseases.
Evaluation of Acne Quality of Life and Clinical Severity in Acne Female Adults
Authors: Kokandi Amal
Published: July 2010

Acne is a common disease especially among teenagers. It has a considerable psychological impact on affected individuals. The aim of this paper was to assess if the effect of acne on acne‐related quality of life is correlated to acne clinical severity. 112 university female students attending the university medical clinics with acne complaints were examined. Cardiff Acne Disability Index (CADI) was used to assess acne‐related quality of life, and global acne grading system (GAGS) was used to assess clinical severity of acne. There was no correlation between acne severity (GAGS scoring system) and quality of life impairment as assessed by CADI score (r = 0.145, P = .127). Additionally, CADI score did not correlate with disease duration or age of patients. We therefore conclude that acne clinical severity alone does not affect acne‐related quality of life changes. Many other factors might play a role.
The Active Management of Impending Cephalopelvic Disproportion in Nulliparous Women at Term: A Case Series
Authors: Nicholson James M. , Kellar Lisa C.
Published: July 2010

Background. The Active Management of Risk in Pregnancy at Term (AMOR-IPAT) protocol has been associated in several studies with significant reductions of group cesarean delivery rate. Present within each of these studies were nulliparous women with risk factors for cephalopelvic disproportion. Risk factors for cephalopelvic disproportion in nulliparous women are especially important because they represent the precursors for the most common indication for primary cesarean delivery.Cases. Three examples of exposure of urban nulliparous women to the AMOR-IPAT protocol are presented. Each woman's risk factor profile for Cephalopelvic Disproportion (CPD) was used to estimate her Upper Limit of Optimal Time of Vaginal Delivery for CPD (UL-OTDcpd). Labor management and clinical outcomes for each case are presented. A simple table summarizing induction rates and birth outcome rates of exposed versus nonexposed nulliparous women is also presented.Conclusion. Because the mode of delivery of the first birth substantially impacts birth options in later pregnancies, the impact of AMOR-IPAT on nulliparous patients is particularly important. Determining the UL-OTDcpd in nulliparous patients, and carefully inducing each patient who has not entered labor by her UL-OTDcpd, may be an effective way of lowering rates of cesarean delivery in nulliparous women.
PPARs, Cardiovascular Metabolism, and Function: Near- or Far-from-Equilibrium Pathways
Authors: Lecarpentier Yves , Claes Victor , Hébert Jean-Louis
Published: July 2010

Peroxisome proliferator-activated receptors (PPAR α, β/δ and γ) play a key role in metabolic regulatory processes and gene regulation of cellular metabolism, particularly in the cardiovascular system. Moreover, PPARs have various extra metabolic roles, in circadian rhythms, inflammation and oxidative stress. In this review, we focus mainly on the effects of PPARs on some thermodynamic processes, which can behave either near equilibrium, or far-from-equilibrium. New functions of PPARs are reported in the arrhythmogenic right ventricular cardiomyopathy, a human genetic heart disease. It is now possible to link the genetic desmosomal abnormalitiy to the presence of fat in the right ventricle, partly due to an overexpression of PPARγ. Moreover, PPARs are directly or indirectly involved in cellular oscillatory processes such as the Wnt-b-catenin pathway, circadian rhythms of arterial blood pressure and cardiac frequency and glycolysis metabolic pathway. Dysfunction of clock genes and PPARγ may lead to hyperphagia, obesity, metabolic syndrome, myocardial infarction and sudden cardiac death, In pathological conditions, regulatory processes of the cardiovascular system may bifurcate towards new states, such as those encountered in hypertension, type 2 diabetes, and heart failure. Numerous of these oscillatory mechanisms, organized in time and space, behave far from equilibrium and are “dissipative structures”.
Geographic Distribution of Childbirth among Adolescents in Cameroon from 2003 to 2005
Authors: Tebeu P. M. , Kemfang J. D. , Sandjong D. I. , Kongnyuy E. , Halle G. , Doh A. S.
Published: July 2010

Objective. To determine the frequency and the trend of adolescents (10–19 years) in childbirth within a period of 3 years in referral maternity units in Cameroon. Method. Descriptive and retrospective study for a 3‐year period (2003–2005) in referral maternity units headed by a qualified Obstetrician‐Gynecologist. We analyzed the trend and geographic distribution of 8222 adolescent deliveries over 3 years. Epi Info 3.5 software was used for data analysis. Chi square test for trend was used to assess the contribution of adolescent deliveries over years. The trend was considered significant if P < .05. Results. During the period of the study, there was a total of 8387 deliveries. We excluded 165 women because of lack of information about age. We therefore included a total of 8222 adolescent deliveries. Overall, the contribution of adolescents to deliveries ranged from 6.87% to 26.51%, depending on the region with a national mean of 14.23%. Adolescents aged 16 or less contributed to 2.82% of deliveries while those aged from 17 to 19 contributed to 11.41%. The contribution of adolescents to deliveries decreased significantly over 3 years (P < .0001). Conclusion. The study underscores the importance of Public Health programs in strengthening maternity services for adolescents in Cameroon while taking into consideration geographic differences.
Stability and Control for Energy Production Parametric Dependence
Authors: Carlini Maurizio , Castellucci Sonia , Guerrieri Mirko , Honorati Tommaso
Published: July 2010

The activities of plant cultivation in Italy are provided by prefabricated structures that are designed to avoid any preliminary study of optical and thermal exchanges between the external environment and the green house. Designers mainly focused on the heating and cooling system to obtain climate beneficial effects on plant growth. This system involves rather significant operating costs which have driven the interests of designers, builders, and farmers to pursue constructive solutions such as the optimization and control of energy flows in the system. In this paper we take into account a model of greenhouse for plant cultivation to be located in Central Italy. For the optimal design of a greenhouse, simulations of heat exchange and flow of energy have been made in order to maximise the cooling system consumption of energy.
A Mathematical Analysis of the Strip‐Element Method for the Computation of Dispersion Curves of Guided Waves in Anisotropic Layered Media
Authors: Schöpfer F. , Binder F. , Wöstehoff A. , Schuster T.
Published: July 2010

Dispersion curves of elastic guided waves in plates can be efficiently
computed by the Strip‐Element Method. This method is based on a finite‐element
discretization in the thickness direction of the plate and leads to an eigenvalue
problem relating frequencies to wavenumbers of the wave modes. In this paper
we present a rigorous mathematical background of the Strip‐Element Method
for anisotropic media including a thorough analysis of the corresponding infinite‐dimensional
eigenvalue problem as well as a proof of the existence of eigenvalues.
Ultra-Wideband Indoor Channel Modelling Using Ray-Tracing Software for through-the-Wall Imaging Radar
Authors: Lièbe Christophe , Combeau Pierre , Gaugue Alain , Pousset Yannis , Aveneau Lilian , Vauzelle Rodolphe , Ogier Jean-Marc
Published: July 2010

This paper presents a new software for design of through-the-wall imaging radars. The first part describes the evolution of a ray tracing simulator, originally designed for propagation of narrowband signals, and then for ultra-wideband signals. This simulator allows to obtain temporal channel response to a wide-band emitter (3 GHz to 10 GHz). An experimental method is also described to identify the propagation paths. Simulation results are compared to propagation experiments under the same conditions. Different configurations are tested and then discussed. Finally, a configuration of through-the-wall imaging radar is proposed, with different antennas patterns and different targets. Simulated images will be helpful for understanding the experiment obtained images.
First-Trimester Prenatal Diagnosis of Okihiro Syndrome
Authors: Becker R. , Horn D. , Knoll U. , Stumm M. , Wegner R.D. , Peters H. , Sarioglu N.
Published: July 2010

A case of Okihiro syndrome (OS) detected by 2- and confirmed by 3-dimensional ultrasound at 13+2 gestational weeks is reported. While the pregnant woman affected by the OS presented with limb anomalies, the fetus showed severe thoracoabdominal and skeletal anomalies. Termination of pregnancy was performed at 14+1 gestational weeks and confirmed the sonographically detected symptoms. The diagnosis was confirmed by autoptic, radiologic and molecular genetic analysis. To our knowledge, this is the first case of prenatal diagnosis of OS.
Congenital Giant Cervical Teratoma: Pre- and Postnatal Imaging
Authors: Figueiredo Giovanna , Pinto Pedro S. , Graham Ernest M. , Huisman Thierry A.G.M.
Published: July 2010

Pre- and postnatal imaging findings are presented in a fetus/neonate with congenital cervical teratoma (CCT). Prenatal fetal MRI proved to be essential in the exact localization and characterization of the CCT while excluding potentially life-threatening prenatal complications. The provided information improved outcome by guiding decisions concerning delivery and postnatal care.
Performance of 36 Different Weight Estimation Formulae in Fetuses with Macrosomia
Authors: Hoopmann Markus , Abele Harald , Wagner Norbert , Wallwiener Diethlem , Kagan Karl O.
Published: July 2010

Introduction: The aim of this retrospective clinical study was to compare the accuracy of 36 commonly used weight estimation formulae in macrosomic fetuses. Material and Methods: Ultrasound estimation of fetal weight (FW) was carried out within 7 days up to delivery in 350 singleton fetuses with a birth weight (BW) of ≧4,000 g. The accuracy of the different formulae for FW estimation was compared by, firstly, the mean percentage (MPE) and mean absolute percentage error (MAPE), secondly, by the frequency distribution of differences between estimated FW and fetal BW, and thirdly by comparing detection and false positive rates in screening for fetuses with a BW of 4,000, 4,300 and 4,500 g or more. Results: MPE ranged from –62.2 to 9.6% and was closest to 0 with the Hart formula. With 12 of 36 weight estimation formulae, MAPE was 10% or less, and was smallest with the Hart formulae (3.9%). The mean detection rate among all formulae for fetuses with a BW ≧4,000, ≧4,300 and ≧4,500 g was 29, 24 and 22%, respectively, and the false positive rate was 12% (for ≧4,300 g) and 7% (≧4,500 g). Discussion: Some formulae showed advantages as far as mean and absolute percentage errors were concerned, but none reached a detection rate and false positive rate for fetuses ≧4,500 g that could lead to clinical recommendation.
Twin Anemia-Polycythemia Sequence: Diagnostic Criteria, Classification, Perinatal Management and Outcome
Authors: Slaghekke F. , Kist W.J. , Oepkes D. , Pasman S.A. , Middeldorp J.M. , Klumper F.J. , Walther F.J. , Vandenbussche F.P.H.A. , Lopriore E.
Published: July 2010

Monochorionic twins share a single placenta with intertwin vascular anastomoses, allowing the transfer of blood from one fetus to the other and vice versa. These anastomoses are the essential anatomical substrate for the development of several complications, including twin-twin transfusion syndrome (TTTS) and twin anemia-polycythemia sequence (TAPS). TTTS and TAPS are both chronic forms of fetofetal transfusion. TTTS is characterized by the twin oligopolyhydramnios sequence, whereas TAPS is characterized by large intertwin hemoglobin differences in the absence of amniotic fluid discordances. TAPS may occur spontaneously in up to 5% of monochorionic twins and may also develop after incomplete laser treatment in TTTS cases. This review focuses on the pathogenesis, incidence, diagnostic criteria, management options and outcome in TAPS. In addition, we propose a classification system for antenatal and postnatal TAPS.
Spontaneous Triplet Pregnancy Complicated by Uterus Didelphys: A Case Report
Authors: Díaz-García César , Subirá Nadal Jessica P. , Urgal Ayala Amaya , Cazorla Amorós Eduardo , Borrás Suñer Dolores , Perales Marín Alfredo
Published: July 2010

Uterine malformations and spontaneous triplet pregnancy are rare situations separately, and both are related to worse perinatal outcomes. In the 3 cases of combined triplet pregnancy and uterus didelphys previously published, at least 2 of the 3 fetuses died. Morbidity rates are also high. We report the case of a 24-year-old Caucasian woman with a uterus didelphys and two previous caesarean sections who carried a spontaneous triplet pregnancy. To our knowledge, this is the first case of a spontaneous triplet pregnancy in a uterus didelphys ever reported and the only one with uneventful perinatal outcome for all fetuses. Expectant management may be an alternative to embryo reduction to manage triplet pregnancies in a didelphys uterus, especially when this option is not considered. Nevertheless, there is not enough evidence to confirm which is the optimal management strategy, and more studies are needed.
Is Stroke History Reliably Reported by Elderly with Cognitive Impairment? A Community-Based Study
Authors: Jin Ya-Ping , Di Legge Silvia , Østbye Truls , Feightner John W. , Saposnik Gustavo , Hachinski Vladimir
Published: July 2010

Background/Aims: Self-reported history of stroke has been questioned in the elderly due to the high prevalence of cognitive impairment. We tested the validity of response to a stroke questionnaire versus clinical diagnosis of stroke among elderly people with and without cognitive impairment. Methods: Community-dwelling participants to the phase 1 Canadian Study of Health and Aging were screened for self-reported stroke. Physician-diagnosed stroke was set as the gold standard. The positive predictive value (PPV), sensitivity and specificity were determined. Results: 1,536/ 1,659 (93%) participants aged 65 years and over had stroke information from both sources. Among stroke positive responders, the PPV was 81% overall: 76% for cognitively normal, 84% for cognitively impairment with no dementia (CIND), and 82% for demented. Among stroke diagnosed by physicians, history of stroke was reported by 38% cognitively normal, 54% CIND, and 55% demented. The specificity was over 97% in all cognitive categories. Conclusion: Among community-dwelling elderly people, any cognitive impairment did not imply inaccurate self-reported history of stroke. High prevalence of stroke and frequent contacts with health services among cognitively-impaired elderly may increase the awareness of stroke symptoms and signs. Stroke increases the risk of developing dementia in both cognitively normal and CIND, and efforts to accomplish stroke prevention are justified, especially in these categories.
Foot-Dipping in Coma: A Physical Sign Indicative of Evolving Herniation
Authors: Chang Gregory Youngnam
Published: July 2010

Objective: Intermittent spontaneous recurrent foot movement characterized by sudden ankle dorsiflexion followed by slower relaxation, termed foot-dipping (FD), may occur in coma. The clinical significance of this easily overlooked sign is unknown. Methods: Twenty-three cases were identified by a single observer over a 10-year period of predominant inpatient neurologic care. Details of neurologic examination, clinical outcome, and CT and/or MRI findings were collected and analyzed. Results: All 23 patients presented with either an acute supratentorial vascular lesion accompanied by a midline brain shift (Group I, 12 cases) or a primary brainstem or cerebellar insult (Group II, 11 cases). FD in Group I patients was observed transiently only during evolving transtentorial herniation manifested by coma and partial brainstem areflexia. Conclusion: The onset of FD in patients with acute supratentorial vascular lesion is indicative of a transtentorial herniation with secondary brainstem encroachment.
Cardiac Positron Emission Tomography/Computed Tomography Imaging Accurately Detects Anatomically and Functionally Significant Coronary Artery Disease
Authors: Kajander S. , Joutsiniemi E. , Saraste M. , Pietilä M. , Ukkonen H. , Saraste A. , Sipilä H.T. , Teräs M. , Mäki M. , Airaksinen J. , Hartiala J. , Knuuti J.
Published: July 2010

Background—

Computed tomography (CT) is increasingly used to detect coronary artery disease, but the evaluation of stenoses is often uncertain. Perfusion imaging has an established role in detecting ischemia and guiding therapy. Hybrid positron emission tomography (PET)/CT allows combination angiography and perfusion imaging in short, quantitative, low-radiation-dose protocols.

Methods and Results—

We enrolled 107 patients with an intermediate (30% to 70%) pretest likelihood of coronary artery disease. All patients underwent PET/CT (quantitative PET with
15
O-water and CT angiography), and the results were compared with the gold standard, invasive angiography, including measurement of fractional flow reserve when appropriate. Although PET and CT angiography alone both demonstrated 97% negative predictive value, CT angiography alone was suboptimal in assessing the severity of stenosis (positive predictive value, 81%). Perfusion imaging alone could not always separate microvascular disease from epicardial stenoses, but hybrid PET/CT significantly improved this accuracy to 98%. The radiation dose of the combined PET and CT protocols was 9.3 mSv (86 patients) with prospective triggering and 21.8 mSv (21 patients) with spiral CT.

Conclusion—

Cardiac hybrid PET/CT imaging allows accurate noninvasive detection of coronary artery disease in a symptomatic population. The method is feasible and can be performed routinely with <10 mSv in most patients.

Clinical Trial Registration—

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00627172.
First Clinical Application of an Actively Reversible Direct Factor IXa Inhibitor as an Anticoagulation Strategy in Patients Undergoing Percutaneous Coronary Intervention
Authors: Cohen Mauricio G. , Purdy Drew A. , Rossi Joseph S. , Grinfeld Liliana R. , Myles Shelley K. , Aberle Laura H. , Greenbaum Adam B. , Fry Edward , Chan Mark Y. , Tonkens Ross M. , Zelenkofske Steven , Alexander John H. , Harrington Robert A. , Rusconi Christopher P. , Becker Richard C.
Published: July 2010

Background—

The ideal anticoagulant should prevent ischemic complications without increasing the risk of bleeding. Controlled anticoagulation is possible with the REG1 system, an RNA aptamer pair comprising the direct factor IXa inhibitor RB006 and its active control agent RB007.

Methods and Results—

This phase 2a study included a roll-in group (n=2) treated with REG1 plus glycoprotein IIb/IIIa inhibitors followed by 2 groups randomized 5:1 to REG1 or unfractionated heparin. In group 1 (n=12), RB006 was partially reversed with RB007 after percutaneous coronary intervention and fully reversed 4 hours later. In group 2 (n=12), RB006 was fully reversed with RB007 immediately after percutaneous coronary intervention. Femoral sheaths were removed after complete reversal. Patients were pretreated with aspirin and clopidogrel. End points included major bleeding within 48 hours; composite of death, myocardial infarction, or urgent target vessel revascularization within 14 days; and pharmacodynamic measures. All cases were successful, with final Thrombolysis in Myocardial Infarction grade 3 flow and no angiographic thrombotic complications. There were 2 ischemic end points in the REG1 group and 1 in the unfractionated heparin group, with 1 major bleed in the unfractionated heparin group. Median activated clotting time values rose from 151 to 236 seconds after RB006. Administration of the partial RB007 dose reversed anticoagulation to an intermediate activated clotting time value of 186 seconds. Complete reversal with RB007 returned the median activated clotting time value to 144 seconds. Both reversal strategies enabled scheduled femoral sheath removal.

Conclusions—

This study demonstrates the clinical translation of a novel platform of anticoagulation targeting factor IXa and its active reversal to percutaneous coronary intervention and provides the basis for further investigation.

Clinical Trial Registration—

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00715455.
Central Pulse Pressure in Chronic Kidney Disease
Authors: Townsend Raymond R. , Chirinos Julio A. , Parsa Afshin , Weir Matthew A. , Sozio Stephen M. , Lash James P. , Chen Jing , Steigerwalt Susan P. , Go Alan S. , Hsu Chi-yuan , Rafey Mohammed , Wright Jackson T. , Duckworth Mark J. , Gadegbeku Crystal A. , Joffe Marshall P.
Published: July 2010

Central pulse pressure (PP) can be noninvasively derived using the radial artery tonometric methods. Knowledge of central pressure profiles has predicted cardiovascular morbidity and mortality in several populations of patients, particularly those with known coronary artery disease and those receiving dialysis. Few data exist characterizing central pressure profiles in patients with mild-moderate chronic kidney disease who are not on dialysis. We measured central PP cross-sectionally in 2531 participants in the Chronic Renal Insufficiency Cohort Study to determine correlates of the magnitude of central PP in the setting of chronic kidney disease. Tertiles of central PP were <36 mm Hg, 36 to 51 mm Hg, and >51 mm Hg with an overall mean (±SD) of 46±19 mm Hg. Multivariable regression identified the following independent correlates of central PP: age, sex, diabetes mellitus, heart rate (negatively correlated), glycosylated hemoglobin, hemoglobin, glucose, and parathyroid hormone parathyroid hormone concentrations. Additional adjustment for brachial mean arterial pressure and brachial PP showed associations for age, sex, diabetes mellitus, weight, and heart rate. Discrete intervals of brachial PP stratification showed substantial overlap within the associated central PP values. The large size of this unique chronic kidney disease cohort provides an ideal situation to study the role of brachial and central pressure measurements in kidney disease progression and cardiovascular disease incidence.
Chronic Hypoxia Inhibits Sex Steroid Hormone-Mediated Attenuation of Ovine Uterine Arterial Myogenic Tone in Pregnancy
Authors: Chang Katherine , Xiao DaLiao , Huang Xiaohui , Xue Zhice , Yang Shumei , Longo Lawrence D. , Zhang Lubo
Published: July 2010

Previous studies in ovine uterine arteries have demonstrated that sex steroid hormones upregulate extracellular signal–regulated kinase 1/2 expression and downregulate the protein kinase C signaling pathway, resulting in the attenuated myogenic tone in pregnancy. The present study tested the hypothesis that chronic hypoxia during gestation inhibits the sex steroid-mediated adaptation of extracellular signal–regulated kinase 1/2 and protein kinase C signaling pathways and increases the myogenic tone of uterine arteries. Uterine arteries were isolated from nonpregnant and near-term pregnant sheep that had been maintained at sea level (≈300 m) or exposed to high-altitude (3801 m) hypoxia for 110 days. In contrast to the previous findings in normoxic animals, 17β-estradiol and progesterone failed to suppress protein kinase C–induced contractions and the pressure-induced myogenic tone in uterine arteries from hypoxic animals. Western analyses showed that the sex steroids lost their effects on extracellular signal–regulated kinase 1/2 expression and phospho- extracellular signal–regulated kinase 1/2 levels, as well as the activation of protein kinase C isozymes in uterine arteries of hypoxic ewes. In normoxic animals, pregnancy and the sex steroid treatments significantly increased uterine artery estrogen receptor-α and progesterone receptor B expression. Chronic hypoxia selectively downregulated estrogen receptor-α expression in uterine arteries of pregnant animals and eliminated the upregulation of estrogen receptor-α in pregnancy or by the steroid treatments observed in normoxic animals. The results demonstrate that, in the ovine uterine artery, chronic hypoxia in pregnancy inhibits the sex steroid hormone–mediated adaptation of decreased myogenic tone by downregulating estrogen receptor-α expression, providing a mechanism linking hypoxia and maladaptation of uteroplacental circulation and an increased risk of preeclampsia in pregnancy.
Reliability of Metalloceramic and Zirconia-based Ceramic Crowns
Authors: Silva N.R.F.A. , Bonfante E.A. , Zavanelli R.A. , Thompson V.P. , Ferencz J.L. , Coelho P.G.
Published: July 2010

Despite the increasing utilization of all-ceramic crown systems, their mechanical performance relative to that of metal ceramic restorations (MCR) has yet to be determined. This investigation tested the hypothesis that MCR present higher reliability over two Y-TZP all-ceramic crown systems under mouth-motion fatigue conditions. A CAD-based tooth preparation with the average dimensions of a mandibular first molar was used as a master die to fabricate all restorations. One 0.5-mm Pd-Ag and two Y-TZP system cores were veneered with 1.5 mm porcelain. Crowns were cemented onto aged (60 days in water) composite (Z100, 3M/ESPE) reproductions of the die. Mouth-motion fatigue was performed, and use level probability Weibull curves were determined. Failure modes of all systems included chipping or fracture of the porcelain veneer initiating at the indentation site. Fatigue was an acceleration factor for all-ceramic systems, but not for the MCR system. The latter presented significantly higher reliability under mouth-motion cyclic mechanical testing.
12-year Survival of Composite vs. Amalgam Restorations
Authors: Opdam N.J.M. , Bronkhorst E.M. , Loomans B.A.C. , Huysmans M.-C.D.N.J.M.
Published: July 2010

Information about the long-term clinical survival of large amalgam and composite restorations is still lacking. This retrospective study compares the longevity of three- and four-/five-surface amalgam and composite restorations relative to patients’ caries risk. Patient records from a general practice were used for data collection. We evaluated 1949 large class II restorations (1202 amalgam/747 composite). Dates of placement, replacement, and failure were recorded, and caries risk of patients was assessed. Survival was calculated from Kaplan-Meier statistics. After 12 years, 293 amalgam and 114 composite restorations had failed. Large composite restorations showed a higher survival in the combined population and in the low-risk group. For three-surface restorations in high-risk patients, amalgam showed better survival.
Elements of Working Memory as Predictors of Goal-Setting Skills in Children With Attention-Deficit/ Hyperactivity Disorder
Authors: Nyman Anna , Taskinen Taina , Grönroos Matti , Haataja Leena , Lähdetie Jaana , Korhonen Tapio
Published: July 2010

The aim of the study was to examine how goal-setting skills of children with attention-deficit/hyperactivity disorder (ADHD) can be predicted with elements of working memory. The study involved 30 children with an ADHD diagnosis and 30 healthy volunteers. The IQ of the participants was assessed, and ADHD symptoms were evaluated by parents. Each of the elements of working memory was assessed with two measures as well as goal-setting skills. In the tests of the central executive and in one of the tests of the visuospatial sketch pad, children with ADHD performed more poorly than did controls but not in the tests of the phonological loop. Children with ADHD performed more poorly than controls did on the mastery scores of the goal-setting measures but not on the Strategy scores. According to regression analysis, central executive functions are critical for the variance in goal-setting skills in children with ADHD.
Determinants of Dynamics in the World City Network, 2000-2004
Authors: Orozco Pereira Renato A. , Derudder Ben
Published: July 2010

This article presents an analysis of the determinants of connectivity change in the world city network (WCN). Drawing on the theoretical research of Saskia Sassen and the subsequent empirical research of the Globalization and World Cities (GaWC) group, connectivity in the WCN is measured through the networked location strategies of globalised service firms. Based on a calculation of the total connectivity of 220 cities across the world for 2000 and 2004, a measurement of connectivity change is produced for this time-period. This measure of connectivity change is then used as the dependent variable in a linear regression model through which are tested a number of hypotheses concerning the determinants of connectivity change. The study analyses WCN change both in general and in sectoral terms, and also examines how the prior presence of service firms impacts connectivity change.
Trajectories of North—South City Inter-relations: Johannesburg and Cape Town, 1994—2007
Authors: Pirie Gordon
Published: July 2010

Examining networks of cities in the world rather than ‘world cityness’, the study offers a ‘Southern’ perspective on world city research. It includes places not ordinarily considered. Fourteen years of sample data on cross-border, intercity airline traffic are used as time-series relational information. The data express links between two of South Africa’s principal cities and cities elsewhere in Africa and beyond. The analysis shows persistent and intensifying links, but also sporadic and unstable intercity relations. A gathering concentration on proximate city pairs is apparent. The research also reveals that urban areas commonly regarded as topping the world city hierarchy mix with smaller and less well-known African places in the rankings of connections with Johannesburg and Cape Town. The complex intercity links which constitute urban significance on the world map are not reducible to a subordinate nesting of Third World city ties in a dominant First World matrix.