bluuebunny/crossref_metadata_2025 huggingface dataset:
Use of Faropenem as an Indicator of Carbapenemase Activity in the Enterobacteriaceae
Authors: Day Kathryn M. , Pike Rachel , Winstanley Trevor G. , Lanyon Clare , Cummings Stephen P. , Raza Muhammad W. , Woodford Neil , Perry John D.
Published: April 2013

The aim of this study was to determine the ability of a disc susceptibility test using faropenem (10 μg) to predict carbapenemase activity in
Enterobacteriaceae
. A collection of 166 isolates of carbapenemase-producing
Enterobacteriaceae
(CPE) and 82 isolates of
Enterobacteriaceae
that produced other β-lactamases was compiled from diverse sources. Disc susceptibility testing was performed using the CLSI/EUCAST methodology with discs of faropenem (10 μg), temocillin (30 μg), and four carbapenems (each 10 μg). A further prospective evaluation of the faropenem disc susceptibility test was performed using 205 consecutive isolates referred to a United Kingdom reference laboratory in parallel with molecular methods for carbapenemase detection. Of 166 isolates of CPE, 99% showed growth up to the edge of a 10-μg faropenem disc compared with only 6% of other β-lactamase producers (sensitivity, 99%; specificity, 94%). A “double zone” around 10-μg faropenem discs was frequently associated with OXA-48 producers. Of the carbapenems, the most useful agent was imipenem, where a zone diameter of ≤23 mm as a predictor of carbapenemase activity had a sensitivity of 99% and a specificity of 85%. The presence of no zone of inhibition around a 30-μg temocillin disc was a consistent feature of strains producing OXA-48 carbapenemase. For 205 isolates of
Enterobacteriaceae
referred to a United Kingdom reference laboratory, growth up to a 10-μg faropenem disc correctly identified 84 of 86 carbapenemase producers (98% sensitivity), with a specificity of 87%. Disc susceptibility testing using faropenem (10 μg) is a simple, convenient, and highly predictive screening test for carbapenemase-producing
Enterobacteriaceae
.
Complete Protection against Severe Acute Respiratory Syndrome Coronavirus-Mediated Lethal Respiratory Disease in Aged Mice by Immunization with a Mouse-Adapted Virus Lacking E Protein
Authors: Fett Craig , DeDiego Marta L. , Regla-Nava Jose A. , Enjuanes Luis , Perlman Stanley
Published: April 2013

Zoonotic coronaviruses, including the one that caused severe acute respiratory syndrome (SARS), cause significant morbidity and mortality in humans. No specific therapy for any human coronavirus is available, making vaccine development critical for protection against these viruses. We previously showed that recombinant SARS coronavirus (SARS-CoV) (Urbani strain based) lacking envelope (E) protein expression (rU-ΔE) provided good but not perfect protection in young mice against challenge with virulent mouse-adapted SARS-CoV (MA15). To improve vaccine efficacy, we developed a second set of E-deleted vaccine candidates on an MA15 background (rMA15-ΔE). rMA15-ΔE is safe, causing no disease in 6-week-, 12-month-, or 18-month-old BALB/c mice. Immunization with this virus completely protected mice of three ages from lethal disease and effected more-rapid virus clearance. Compared to rU-ΔE, rMA15-ΔE immunization resulted in significantly greater neutralizing antibody and SARS-CoV-specific CD4 and CD8 T cell responses. After challenge, inflammatory cell infiltration, edema, and lung destruction were decreased in the lungs of rMA15-ΔE-immunized mice compared to those in rU-ΔE-immunized 12-month-old mice. Collectively, these results show that immunization with a species-adapted attenuated coronavirus lacking E protein expression is safe and provides optimal immunogenicity and long-term protection against challenge with lethal virus. This approach will be generally useful for development of vaccines protective against human coronaviruses as well as against coronaviruses that cause disease in domestic and companion animals.
Structure of the Tetramerization Domain of Measles Virus Phosphoprotein
Authors: Communie Guillaume , Crépin Thibaut , Maurin Damien , Jensen Malene Ringkjøbing , Blackledge Martin , Ruigrok Rob W. H.
Published: April 2013

The atomic structure of the stable tetramerization domain of the measles virus phosphoprotein shows a tight four-stranded coiled coil. Although at first sight similar to the tetramerization domain of the Sendai virus phosphoprotein, which has a hydrophilic interface, the measles virus domain has kinked helices that have a strongly hydrophobic interface and it lacks the additional N-terminal three helical bundles linking the long helices.
Directional Release of Reovirus from the Apical Surface of Polarized Endothelial Cells
Authors: Lai Caroline M. , Mainou Bernardo A. , Kim Kwang S. , Dermody Terence S.
Published: April 2013

Bloodstream spread is a critical step in the pathogenesis of many viruses. However, mechanisms that promote viremia are not well understood. Reoviruses are neurotropic viruses that disseminate hematogenously to the central nervous system. Junctional adhesion molecule A (JAM-A) is a tight junction protein that serves as a receptor for reovirus. JAM-A is required for establishment of viremia in infected newborn mice and viral spread to sites of secondary replication. To determine how viruses gain access to the circulatory system, we examined reovirus infection of polarized human brain microvascular endothelial cells (HBMECs). Reovirus productively infects polarized HBMECs, but infection does not alter tight junction integrity. Apical infection of polarized HBMECs is more efficient than basolateral infection, which is attributable to viral engagement of sialic acid and JAM-A. Viral release occurs exclusively from the apical surface via a mechanism that is not associated with lysis or apoptosis of infected cells. These data suggest that infection of endothelial cells routes reovirus apically into the bloodstream for systemic dissemination in the host. Understanding how viruses invade the bloodstream may aid in the development of therapeutics that block this step in viral pathogenesis.

IMPORTANCE
Bloodstream spread of viruses within infected hosts is a critical but poorly understood step in viral disease. Reoviruses first enter the host through the oral or respiratory route and infect cells in the central nervous system. Spread of reoviruses to the brain occurs by blood or nerves, which makes reoviruses useful models for studies of systemic viral dissemination. In this study, we examined how reoviruses infect endothelial cells, which form the walls of blood vessels. We found that reovirus infection of endothelial cells allows the virus to enter blood vessels and serves as a means for the virus to reach high titers in the circulation. Understanding how reovirus is routed through endothelial cells may aid in the design of antiviral drugs that target this important step in systemic viral infections.
Is it toxoplasma encephalitis, HIV encephalopathy or brain tuberculoma?
Authors: Nimir Amal Rashad , Osman Emilia , Ibrahim Ibrahim Abdel Aziz , Saliem Ahmed M
Published: April 2013

A 31-year-old Malaysian man was presented with an episode of seizures by the roadside, after having been recently diagnosed as HIV positive accompanied with miliary tuberculosis. On physical examination, he was oriented to person, but not to time or place. There was no neck stiffness or papilloedema. The other systemic examination was unremarkable. Chest examination revealed crepitations at the upper zone of the right lung. After diagnosis suspicion, the case was confirmed as toxoplasma encephalitis by MRI and serological tests. Patient was treated with trimethoprim/sulfamethoxazole 480–2400 mg/day with folinic acid supplement for 60 days. Two months later, a repeat brain MRI showed resolution of the cerebral lesions.
What determines patient satisfaction with surgery? A prospective cohort study of 4709 patients following total joint replacement
Authors: Hamilton D F , Lane J V , Gaston P , Patton J T , MacDonald D , Simpson A H R W , Howie C R
Published: April 2013

Objectives

To investigate the factors which influence patient satisfaction with surgical services and to explore the relationship between overall satisfaction, satisfaction with specific facets of outcome and measured clinical outcomes (patient reported outcome measures (PROMs)).

Design

Prospective cohort study.

Setting

Single National Health Service (NHS) teaching hospital.

Participants

4709 individuals undergoing primary lower limb joint replacement over a 4-year period (January 2006–December 2010).

Main outcome measures

Overall patient satisfaction, clinical outcomes as measured by PROMs (Oxford Hip or Knee Score, SF-12), satisfaction with five specific aspects of surgical outcome, attitudes towards further surgery, length of hospital stay.

Results

Overall patient satisfaction was predicted by: (1) meeting preoperative expectations (OR 2.62 (95% CI 2.24 to 3.07)), (2) satisfaction with pain relief (2.40 (2.00 to 2.87)), (3) satisfaction with the hospital experience (1.7 (1.45 to 1.91)), (4) 12 months (1.08 (1.05 to 1.10)) and (5) preoperative (0.95 (0.93 to 0.97)) Oxford scores. These five factors contributed to a model able to correctly predict 97% of the variation in overall patient satisfaction response. The factors having greatest effect were the degree to which patient expectations were met and satisfaction with pain relief; the Oxford scores carried little weight in the algorithm. Various factors previously reported to influence clinical outcomes such as age, gender, comorbidities and length of postoperative hospital stay did not help explain variation in overall patient satisfaction.

Conclusions

Three factors broadly determine the patient's overall satisfaction following lower limb joint arthroplasty; meeting preoperative expectations, achieving satisfactory pain relief, and a satisfactory hospital experience. Pain relief and expectations are managed by clinical teams; however, a fractured access to surgical services impacts on the patient's hospital experience which may reduce overall satisfaction. In the absence of complications, how we deliver healthcare may be of key importance along with the specifics of what we deliver, which has clear implications for units providing surgical services.
Disabling chronic low back pain as an iatrogenic disorder: a qualitative study in Aboriginal Australians
Authors: Lin Ivan B , O'Sullivan Peter B , Coffin Juli A , Mak Donna B , Toussaint Sandy , Straker Leon M
Published: April 2013

Objectives

To determine the low back pain beliefs of Aboriginal Australians; a population previously identified as protected against the disabling effects of low back pain due to cultural beliefs.

Design

Qualitative study employing culturally appropriate methods within a clinical ethnographic framework.

Setting

One rural and two remote towns in Western Australia.

Participants

Thirty-two Aboriginal people with chronic low-back pain (CLBP; 21 men, 11 women). Participants included those who were highly, moderately and mildly disabled.

Results

Most participants held biomedical beliefs about the cause of CLBP, attributing pain to structural/anatomical vulnerability of their spine. This belief was attributed to the advice from healthcare practitioners and the results of spinal radiological imaging. Negative causal beliefs and a pessimistic future outlook were more common among those who were more disabled. Conversely, those who were less disabled held more positive beliefs that did not originate from interactions with healthcare practitioners.

Conclusions

Findings are consistent with research in other populations and support that disabling CLBP may be at least partly iatrogenic. This raises concerns for all populations exposed to Western biomedical approaches to examination and management of low back pain. The challenge for healthcare practitioners dealing with people with low back pain from any culture is to communicate in a way that builds positive beliefs about low back pain and its future consequences, enhancing resilience to disability.
Quality improvement needed in quality improvement randomised trials: systematic review of interventions to improve care in diabetes
Authors: Ivers Noah M , Tricco Andrea C , Taljaard Monica , Halperin Ilana , Turner Lucy , Moher David , Grimshaw Jeremy M
Published: April 2013

Objective

Despite the increasing numbers of published trials of quality improvement (QI) interventions in diabetes, little is known about the risk of bias in this literature.

Design

Secondary analysis of a systematic review.

Data sources

Medline, the Cochrane Effective Practice and Organisation of Care (EPOC) database (from inception to July 2010) and references of included studies.

Eligibility criteria

Randomised trials assessing 11 predefined QI strategies or financial incentives targeting health systems, healthcare professionals or patients to improve the management of adult outpatients with diabetes.

Analysis

Risk of bias (low, unclear or high) was assessed for the 142 trials in the review across nine domains using the EPOC version of the Cochrane Risk of Bias Tool. We used Cochran-Armitage tests for trends to evaluate the improvement over time.

Results

There was no significant improvement over time in any of the risk of bias domains. Attrition bias (loss to follow-up) was the most common source of bias, with 24 trials (17%) having high risk of bias due to incomplete outcome data. Overall, 69 trials (49%) had at least one domain with high risk of bias. Inadequate reporting frequently hampered the risk of bias assessment: allocation sequence was unclear in 82 trials (58%) and allocation concealment was unclear in 78 trials (55%). There were significant reductions neither in the proportions of studies at high risk of bias over time nor in the adequacy of reporting of risk of bias domains.

Conclusions

Nearly half of the included QI trials in this review were judged to have high risk of bias. Such trials have serious limitations that put the findings in question and therefore inhibit evidence-based QI. There is a need to limit the potential for bias when conducting QI trials and improve the quality of reporting of QI trials so that stakeholders have adequate evidence for implementation.
Modified TIMI risk score cannot be used to identify low-risk chest pain in the emergency department: a multicentre validation study
Authors: Macdonald Stephen P J , Nagree Yusuf , Fatovich Daniel M , Brown Simon G A
Published: April 2013

Aim

The Thrombolysis in Myocardial Infarction (TIMI) risk score (range 0–7), used for emergency department (ED) risk stratification of patients with suspected acute coronary syndrome (ACS), underestimates risk associated with ECG changes or cardiac troponin elevation. A modified TIMI score (mTIMI, range 0–10), which gives increased weighting to these variables, has been proposed. We aimed to evaluate the performance of the mTIMI score in ED patients with suspected ACS.

Methods

A multicentre prospective observational study enrolled patients undergoing assessment for possible ACS. TIMI and mTIMI scores were calculated. The study outcome was a composite of all-cause death, myocardial infarction or coronary revascularisation within 30 days.

Results

Of the 1666 patients, 219 (13%) reached the study outcome. Area under the receiver operating characteristic curve for the composite outcome was 0.80 (0.76 to 0.83) for the mTIMI score compared with 0.71 (0.67 to 0.74) for the standard TIMI score, p<0.001, but there was no significant difference for death or revascularisation outcomes. Sensitivity and specificity for the composite outcome were 0.96 (0.92 to 0.98) and 0.23 (0.20 to 0.26), respectively, at score 0 for TIMI and mTIMI. At score <2, sensitivity and specificity were 0.82 (0.77 to 0.87) and 0.53 (0.51 to 0.56) for mTIMI, and 0.74 (0.68 to 0.79) and 0.54 (0.51 to 0.56) for standard TIMI, respectively.

Conclusions

mTIMI score performs better than standard TIMI score for ED risk stratification of chest pain, but neither is sufficiently sensitive at scores >0 to allow safe and early discharge without further investigation or follow-up. Observed differences in performance may be due to incorporation bias.
‘Out of hours’ adult CT head interpretation by senior emergency department staff following an intensive teaching session: a prospective blinded pilot study of 405 patients
Authors: Jamal Karim , Mandel Laura , Jamal Leila , Gilani Shamim
Published: April 2013

Aim

Cranial CT is the gold standard for the investigation of intracranial emergencies. The aim of this pilot study was to audit whether senior emergency physicians were able to report CT head scans accurately and reliably having attended structured teaching.

Materials and methods

Senior emergency physicians attended a 3 h teaching session. Following this, they independently reported adult CT head scans between 22:00 and 08:00 using a pro forma. CT head examinations performed in this ‘out of hours’ period were formally reported by a consultant radiologist on the following morning. Data were collected in a blinded fashion over an 8-month period.

Results

405 adult CT head examinations were performed. 360 pro formas were available for analysis, and the rest were excluded either because a consultant radiologist had been rung to discuss the results (five patients) or because the pro forma was not completed (40 patients). Concordance between consultant radiologists and emergency physicians was found in 339 (94%) of the cases (κ coefficient 0.78). None of the discordant cases was managed inappropriately or had an adverse clinical outcome. All cases of extradural, subdural and subarachnoid haemorrhage were detected by emergency physicians.

Conclusions

In conclusion, we feel that this model can be employed as a safe and long-term alternative provided that the radiology department are committed to providing ongoing teaching and that a database is maintained to highlight problem areas. Emergency physicians need to remember that the clinical status of the patient must never be ignored, irrespective of their CT head findings.
Green halogenation of aromatic heterocycles using ammonium halide and hydrogen peroxide in acetic acid solvent
Authors: D’Aleo Danielle N. , Allard Sheena R. , Foglia Cassandra C. , Parent Shawna L.M. , Rohr David J. , Gottardo Christine , MacKinnon Craig D.
Published: April 2013

The green generation of X+ (X = Br, I) using hydrogen peroxide in aqueous acetic acid allows access to aromatic heterocyclic halides in yields and purities comparable to syntheses employing N-bromosuccinimide. In activated and unsubstituted thiophene rings, regioselectivity is quantitative for positions α to the sulfur; pyrroles also give quantitative reactions, at least initially. Deactivated rings, including furans and thiazoles, as well as thiophenes with strongly electron-withdrawing groups showed little to no reactivity under the conditions investigated. The reaction shows remarkable functional group tolerance (to alcohol, nitro, alkyl, halo, and carbonyl groups), as shown through reaction with substituted phenols. In all bromination reactions, reaction yields and regiochemistry were very similar to reactions involving N-bromosuccinimide in tetrahydrofuran solvent.
Seismic screening of buildings based on the 2010 National Building Code of Canada
Authors: Saatcioglu M. , Shooshtari M. , Foo S.
Published: April 2013

Seismic screening software is developed for existing buildings in Canada on the basis of the requirements of 2010 National Building Code of Canada. The software is based on the “Manual for Screening of Buildings for Seismic Investigation,” published by the National Research Council of Canada in 1992. The new software incorporates updated seismicity and soil classifications used in the National Building Code of Canada (NBCC) since 2005, as well as the new ductility and over-strength factors specified in the 2010 NBCC. The uniform hazard spectrum values of the current Canadian seismicity, defined for each municipality in Canada with a 2500 year earthquake return period, are used as reference hazard values. Seismic risk associated with the use of older seismic hazard values specified in older editions of the NBCC is identified relative to the current reference seismicity. The new site classifications are incorporated, while establishing relative soil amplification values between the new acceleration-based and velocity-based soil amplification factors and the foundation factors used in older codes. The new ductility and over-strength factors used in recent editions of the code are introduced in identifying different structural types with different toughness and energy dissipation capacities. The software can be used to conduct seismic screening of buildings located in different municipalities in Canada relative to the seismic requirements of NBCC-2010. It can also be used to generate tables for different locations in the country for manual screening of buildings.
SYNTHETIC GRAPHENE GROWN BY CHEMICAL VAPOR DEPOSITION ON COPPER FOILS
Authors: CHUNG TING FUNG , SHEN TIAN , CAO HELIN , JAUREGUI LUIS A. , WU WEI , YU QINGKAI , NEWELL DAVID , CHEN YONG P.
Published: April 2013

The discovery of graphene, a single layer of covalently bonded carbon atoms, has attracted intense interest. Initial studies using mechanically exfoliated graphene unveiled its remarkable electronic, mechanical and thermal properties. There has been a growing need and rapid development in large-area deposition of graphene film and its applications. Chemical vapor deposition on copper has emerged as one of the most promising methods in obtaining large-scale graphene films with quality comparable to exfoliated graphene. In this paper, we review the synthesis and characterizations of graphene grown on copper foil substrates by atmospheric pressure chemical vapor deposition. We also discuss potential applications of such large-scale synthetic graphene.
KLEIN–GORDON FIELDS AND BOSE–EINSTEIN CONDENSATES: THERMAL BATH CONTRIBUTIONS
Authors: CASTELLANOS E. , MATOS T.
Published: April 2013

We analyze the consequences caused by a thermal bath upon the properties associated to the symmetry breaking of scalar fields with one-loop correction potential. Concerning the nonrelativistic regime associated with the aforementioned system, we calculate the shift in the condensation temperature caused by the thermal bath, assuming a harmonic oscillator type potential. We prove that the shift in the condensation temperature depends on the associated scale of the system. In addition, we obtain bounds associated to the scale that could lead to relevant corrections on the condensation temperature under typical conditions.
GEOMETRIC PHASE OF SPIN CHAIN SYSTEM IN THE NONEQUILIBRIUM THERMAL ENVIRONMENTS
Authors: ZHANG XIU-XING , ZHANG AI-PING , ZHANG JIA , WANG JU-XIA
Published: April 2013

In this paper, we investigate the nonequilibrium geometric phase (GP) of a spin chain system whose two end spins are respectively coupled to thermal reservoirs at different temperatures. In the spin chain, there exists the XX-type spin interaction and an external field is applied to each spin. An analytical expression for the GP is found in the weak coupling limit. The influences of various parameters on the deviation of GP from the unitary one are investigated. It is found that the GP is more stable against the decoherence when the external field is homogenously applied. In addition, the present result may provide a useful approach to the maintenance of GP in the nonequilibrium system.
THE ELECTRICAL CHARACTERIZATION OF Ag/N-BuHHPDI/p-Si HETEROJUNCTION BY CURRENT–VOLTAGE CHARACTERISTICS
Authors: TAHIR MUHAMMAD , SAYYAD MUHAMMAD HASSAN , WAHAB FAZAL , KHAN DIL NAWAZ
Published: April 2013

This paper reports the fabrication of Ag / N - BuHHPDI /p- Si heterojunction diode by evaporating a layer of organic compound N-Butyl-N'-(6-hydroxyhexyl) perylene-3,4,9,10-tetracarboxylicacid-diimide (N-BuHHPDI) on top of the p- Si . The electronic properties of the heterojunction have been studied, in dark at a temperature of 300 K, by conventional current–voltage (I–V) method, Norde's method and Cheung's technique. By analyzing conventional I–V characteristics, the device exhibited rectifying behavior with a rectification ratio of 62.67 at ± 5.8 V. From the forward biased I–V measurements, the barrier height and ideality factor values of 0.83 eV and 6.4, respectively, have been obtained. Different diode parameters such as series resistance, shunt resistance, reverse saturation current and turn on voltage have been extracted from the I–V measurements. The parameters calculated from Norde's and Cheung's methods are found to be in good agreement with those calculated from conventional I–V measurements. Morphology of the N-BuHHPDI film is investigated using atomic force microscope (AFM).
SUPERCONDUCTIVITY NEAR POMERANCHUK INSTABILITIES IN THE SPIN CHANNEL
Authors: BARCI DANIEL G. , BONFIM PAULO S. A.
Published: April 2013

We study the competition between a Pomeranchuk instability in the spin channel with angular momentum ℓ = 1 and an attractive interaction, favoring Cooper-pair formation. We found that the superconducting gap strongly suppresses the phase space for the Pomeranchuk instability. We computed a mean-field phase diagram displaying a first order transition between two superconductor phases with different symmetries: p-wave (with spontaneously generated spin-orbit interaction) and s-wave for greater values of the coupling constant. Moreover, we have looked for a possible modulated superconducting phase. We have found that this phase appears only as a metastable state in the strong coupling regime.
MAXIMAL COMPACT SUBGROUPS IN THE O-MINIMAL SETTING
Authors: CONVERSANO ANNALISA
Published: April 2013

A characterization of groups definable in o-minimal structures having maximal definable definably compact subgroups is given. This follows from a definable decomposition in analogy with Lie groups, where the role of maximal tori is played by maximal 0-subgroups. Along the way we give structural theorems for solvable groups, linear groups, and extensions of definably compact by torsion-free definable groups.
WIRELESS ACCELEROMETER SYSTEM FOR QUANTIFYING DISPARITY OF HEMIPLEGIC GAIT USING THE FREQUENCY DOMAIN
Authors: LEMOYNE ROBERT , MASTROIANNI TIMOTHY , GRUNDFEST WARREN
Published: April 2013

The proper allocation of a therapy strategy and dosage is fundamentally associated with the quantified evaluation of gait quality. Wireless accelerometer systems for the evaluation of quantified hemiplegic gait characteristics has been successfully applied in inherently autonomous environments through the consideration of the temporal domain of the gait acceleration waveform. The frequency domain has notable potential for identifying the quantified disparity of the affected leg and unaffected leg through the application of a tandem-activated wireless accelerometer system mounted to the lateral malleolus of each lower leg through an elastic band. The quantification of disparity for hemiplegic gait via the application of wireless accelerometers was applied in an outdoor environment, while walking on a sidewalk. In addition, the wireless accelerometers were tandem activated while the subject had achieved steady-state gait status, which mitigated the need to subjectively remove starting acceleration and stopping deceleration aspects of the gait cycle. Four predominant frequencies within the 0–5 Hz bandwidth demonstrated a considerable degree of accuracy and reliability. The organization of the four predominant frequencies for both affected leg and unaffected leg were found to be disparate in a statistically significant manner, implicating a disparity of the rhythmicity respective of the affected leg in contrast to the unaffected leg in hemiplegic gait. These preliminary findings may advance gait quantification techniques, which may improve the efficacy of gait rehabilitation therapy. Enclosed are the initial test and evaluation of a tandem-activated wireless accelerometer system using the frequency domain for ascertaining a quantified disparity of hemiplegic gait.
WHEN AND WHY WORRY ABOUT REAL EXCHANGE RATE APPRECIATION? THE MISSING LINK BETWEEN DUTCH DISEASE AND GROWTH
Authors: MAGUD NICOLÁS , SOSA SEBASTIÁN
Published: April 2013

We review the literature on Dutch disease, and document that shocks that trigger foreign exchange inflows (such as natural resource booms, surges in foreign aid, remittances, or capital inflows) appreciate the real exchange rate, generate factor reallocation, and reduce manufacturing output and net exports. We also observe that real exchange rate misalignment due to overvaluation and higher volatility of the real exchange rate lower growth. Regarding the effect of undervaluation of the exchange rate on economic growth, the evidence is mixed and inconclusive. However, there is no evidence in the literature that Dutch disease reduces overall economic growth. Policy responses should aim at adequately managing the boom and the risks associated with it.
ROOM-TEMPERATURE ANTIFERROMAGNETIC TUNNELING ANISOTROPIC MAGNETORESISTANCE
Authors: WANG Y. Y. , SONG C. , CUI B. , WANG G. Y. , ZENG F. , PAN F.
Published: April 2013

We systematically investigate the room-temperature antiferromagnetic tunneling anisotropic magnetoresistance (TAMR) effect in [Pt/Co] / IrMn/AlO x/ Pt vertical tunnel junctions as a function of IrMn thicknesses and field directions. The experimental results indicate that a partial rotation of IrMn moments is triggered by ferromagnetic Co/Pt with the formation of exchange-spring in vertical fields, whereas two distinct modes of positive and negative spin-valve-like signals are detected with different in-plane fields due to the unidirectional anisotropy of IrMn . Electrical transport and magnetization reversal measurements confirm the crucial role of stable antiferromagnetic IrMn moments in the observed TAMR effect, which is profoundly affected by the operation temperature, IrMn thicknesses, magnetic fields and field directions.
cAMP attenuates the enhanced expression of Gi proteins and hyperproliferation of vascular smooth muscle cells from SHR: role of ROS and ROS-mediated signaling
Authors: Gusan Svetlana , Anand-Srivastava Madhu B.
Published: April 2013

We previously showed that angiotensin II (ANG II)-induced overexpression of inhibitory G proteins (Gi) was attenuated by dibutyryl-cAMP (db-cAMP) in A10 vascular smooth muscle cells (VSMC). Since enhanced levels of endogenous ANG II contributed to the overexpression of Gi protein and hyperproliferation of VSMC from spontaneously hypertensive rats (SHR), the present study was therefore undertaken to examine if cAMP could also attenuate the overexpression of Gi proteins and hyperproliferation of VSMC from SHR and to explore the underlying molecular mechanisms responsible for this response. The enhanced expression of Giα proteins in VSMC from SHR and Nω-nitro-l-arginine methyl ester hypertensive rats was decreased by db-cAMP. In addition, enhanced inhibition of adenylyl cyclase by inhibitory hormones and forskolin-stimulated adenylyl cyclase activity by low concentration of GTPγS in VSMC from SHR was also restored to Wistar-Kyoto (WKY) levels by db-cAMP. Furthermore, db-cAMP also attenuated the hyperproliferation and the increased production of superoxide anion, NAD(P)H oxidase activity, overexpression of Nox1/Nox2/Nox4 and p47phox proteins, increased phosphorylation of PDGF-receptor (R), EGF-R, c-Src, and ERK1/2 to control levels. In addition, the protein kinase A (PKA) inhibitor reversed the effects of db-cAMP on the expression of Nox4 and Giα proteins and hyperproliferation of VSMC from SHR to WKY levels, while stimulation of the exchange protein directly activated by cAMP did not have any effect on these parameters. These results suggest that cAMP via PKA pathway attenuates the overexpression of Gi proteins and hyperproliferation of VSMC from SHR through the inhibition of ROS and ROS-mediated transactivation of EGF-R/PDGF-R and MAPK signaling pathways.
Adipocyte size and cellular expression of caveolar proteins analyzed by confocal microscopy
Authors: Hulstrøm V. , Prats C. , Vinten J.
Published: April 2013

Caveolae are abundant in adipocytes and are involved in the regulation of lipid accumulation, which is the main volume determinant of these cells. We have developed and applied a confocal microscopic technique for measuring individual cellular expression of the caveolar proteins cavin-1 and caveolin-1 along with the size of individual adipocytes. The technique was applied on collagenase isolated adipocytes from ad libitum fed Sprague-Dawley rats of different age (4–26 wk) and weight (103–629 g). We found that cellular expression of caveolar proteins was variable (SD of log expression in the range from 0.25 to 0.65). Regression analysis of protein expression on adipocyte size revealed that the expression of the caveolar proteins cavin-1 and caveolin-1 on adipocytes from individual rats was tightly related to adipocyte cell surface area (mean coefficient of regression was 0.83 for cavin and 0.77 for caveolin), indicating that caveolar density was the same in membranes from all cells within a biopsy. This intrinsic relation remained unchanged with animal age, but adipocytes from animals with increasing age showed a decrease in mean expression of caveolar proteins per unit cell surface. The different relation between adipocyte size and cellular expression levels of caveolar proteins within and between individuals of different age shows that caveolar density is an age-sensitive characteristic of adipocytes.
Low Po2conditions induce reactive oxygen species formation during contractions in single skeletal muscle fibers
Authors: Zuo Li , Shiah Amy , Roberts William J. , Chien Michael T. , Wagner Peter D. , Hogan Michael C.
Published: April 2013

Contractions in whole skeletal muscle during hypoxia are known to generate reactive oxygen species (ROS); however, identification of real-time ROS formation within isolated single skeletal muscle fibers has been challenging. Consequently, there is no convincing evidence showing increased ROS production in intact contracting fibers under low Po2conditions. Therefore, we hypothesized that intracellular ROS generation in single contracting skeletal myofibers increases during low Po2compared with a value approximating normal resting Po2. Dihydrofluorescein was loaded into single frog ( Xenopus) fibers, and fluorescence was used to monitor ROS using confocal microscopy. Myofibers were exposed to two maximal tetanic contractile periods (1 contraction/3 s for 2 min, separated by a 60-min rest period), each consisting of one of the following treatments: high Po2(30 Torr), low Po2(3–5 Torr), high Po2with ebselen (antioxidant), or low Po2with ebselen. Ebselen (10 μM) was administered before the designated contractile period. ROS formation during low Po2treatment was greater than during high Po2treatment, and ebselen decreased ROS generation in both low- and high-Po2conditions ( P < 0.05). ROS accumulated at a faster rate in low vs. high Po2. Force was reduced >30% for each condition except low Po2with ebselen, which only decreased ∼15%. We concluded that single myofibers under low Po2conditions develop accelerated and more oxidative stress than at Po2= 30 Torr (normal human resting Po2). Ebselen decreases ROS formation in both low and high Po2, but only mitigates skeletal muscle fatigue during reduced Po2conditions.
Exercise-induced increase in maximal in vitro Na-K-ATPase activity in human skeletal muscle
Authors: Juel Carsten , Nordsborg Nikolai B. , Bangsbo Jens
Published: April 2013

The present study investigated whether maximal in vitro Na-K-ATPase activity in human skeletal muscle is changed with exercise and whether it was altered by acute hypoxia. Needle biopsies from 14 subjects were obtained from vastus lateralis before and after 4 min of intense muscle activity. In addition, six subjects exercised also in hypoxia (12.5% oxygen). The Na-K-ATPase assay revealed a 19% increase ( P < 0.05) in maximal velocity ( Vmax) for Na+-dependent Na-K-ATPase activity after exercise and a tendency ( P < 0.1) toward a decrease in Km for Na+ (increased Na+ affinity) in both normoxia and hypoxia. In contrast, the in vitro Na-K-ATPase activity determined with the 3- O-MFPase technique was 11–32% lower after exercise in normoxia ( P < 0.05) and hypoxia ( P < 0.1). Based on the different results obtained with the Na-K-ATPase assay and the 3- O-MFPase technique, it was suggested that the 3- O-MFPase method is insensitive to changes in Na-K-ATPase activity. To test this possibility, changes in Na-K-ATPase activity was induced by protein kinase C activation. The changes quantified with the Na-K-ATPase assay could not be detected with the 3- O-MFPase method. In addition, purines stimulated Na-K-ATPase activity in rat muscle membranes; these changes could not be detected with the 3- O-MFPase method. Therefore, the 3- O-MFPase technique is not sensitive to changes in Na+ sensitivity, and the method is not suited to detecting changes in Na-K-ATPase activity with exercise. In conclusion, muscle activity in humans induces an increased in vitro Na+-dependent Na-K-ATPase activity, which contributes to the upregulation of the Na-K-ATPase in association with exercise both in normoxia and hypoxia.
The role of Toll-like receptor proteins (TLR) 2 and 4 in mediating inflammation in proximal tubules
Authors: Mudaliar Harshini , Pollock Carol , Komala Muralikrishna Gangadharan , Chadban Steven , Wu Huiling , Panchapakesan Usha
Published: April 2013

Inflammatory responses are central to the pathogenesis of diabetic nephropathy. Toll-like receptors (TLRs) are ligand-activated membrane-bound receptors which induce inflammatory responses predominantly through the activation of NF-κB. TLR2 and 4 are present in proximal tubular cells and are activated by endogenous ligands upregulated in diabetic nephropathy, including high-mobility group box-1 (HMGB1) and fibronectin. Human proximal tubules were exposed to 5 mM (control), 11.2 mM (approximating the clinical diagnostic threshold for diabetes mellitus), and 30 mM (high) glucose for 72 h or 7 days. Cells were harvested for protein, mRNA, and nuclear extract to assess for TLR2, 4, and inflammatory markers. Glucose (11.2 mM) maximally increased TLR2 and 4 expression, HMGB1 release, and NF-κB activation with increased expression of cytokines. However, only TLR2 expression and subsequent NF-κB binding were sustained at 7 days. Recombinant HMGB1 induced NF-κB activation, which was prevented by both TLR2 silencing [small interfering (si)RNA] and TLR4 inhibition. Peroxisome proliferator-activated receptor-γ (PPAR-γ) transcription was reduced by exposure to 11.2 mM glucose with an increase observed at 30 mM glucose at 24 h. This may reflect a compensatory increase in PPAR-γ induced by exposure to 30 mM glucose, limiting the inflammatory response. Therefore, short-term moderate increases in glucose in vitro increase HMGB1, which mediates NF-κB activation through both TLR2 and 4. Furthermore, in vivo, streptozotocin-induced diabetic mice exhibited an increase in tubular TLR2 and HMGB1 expression. These results collectively suggest that TLR2 is likely to be the predominant long-term mediator of NF-κB activation in transducing inflammation in diabetic nephropathy.
Dual mechanisms diminishing tonic GABAA inhibition of dentate gyrus granule cells in Noda epileptic rats
Authors: Pandit Sudip , Jeong Ji Ae , Jo Ji Yoon , Cho Hyun Sill , Kim Dong Woon , Kim Jae Moon , Ryu Pan Dong , Lee So Yeong , Kim Hyun Woo , Jeon Byeong Hwa , Park Jin Bong
Published: April 2013

The Noda epileptic rat (NER), a Wistar colony mutant, spontaneously has tonic-clonic convulsions with paroxysmal discharges. In the present study, we measured phasic and tonic γ-aminobutyric acid A (GABAA) current ( Itonic) in NER hippocampal dentate gyrus granule cells and compared the results with those of normal parent strain Wistar rats (WIS). Itonic, revealed by a bicuculline-induced outward shift in holding current, was significantly smaller in NER than in WIS ( P < 0.01). The frequency of inhibitory postsynaptic currents (IPSCs) was also significantly lower in NER than in WIS ( P < 0.05), without significant differences in the IPSC amplitude or decay time between WIS and NER. Itonic attenuation in NER was further confirmed in the presence of GABA transporter blockers, NO-711 and nipecotic acid, with no difference in neuronal GABA transporter expression between WIS and NER. Itonic responses to extrasynaptic GABAA receptor agonists (THIP and DS-2) were significantly reduced in NER compared with WIS ( P < 0.05). Allopregnanolone caused less Itonic increase in NER than in WIS, while it prolonged the IPSC decay time to a similar rate in the two groups. Expression of the GABAA receptor δ-subunit was decreased in the dentate gyrus of NER relative to that of WIS. Taken together, our results showed that a combination of attenuated presynaptic GABA release and extrasynaptic GABAA receptor expression reduced Itonic amplitude and its sensitivity to neurosteroids, which likely diminishes the gating function of dentate gyrus granule cells and renders NER more susceptible to seizure propagation.
Dosimetry and Therapeutic Ratios for Rhenium-186 HEDP
Authors: Argyrou Maria , Valassi Alexia , Andreou Maria , Lyra Maria
Published: April 2013

Rhenium-186 (Re-186) is a β-emitting radionuclide. Emitted β-particles have ranges up to 4.5 mm in tissue, capable of delivering high doses to skeletal regions of high Re-186 concentrations while sparing adjacent radiosensitive regions and thus making the irradiation well tolerated for the patient. Along with the β-emissions, γ-rays are emitted having an adequate energy for imaging during therapy and biodistribution assessment for patient-specific dosimetry calculations. The relatively short physical half-life combined with the β-emissions allows the delivery of relatively high activity rate for a short period of time in areas of concentration. This study is a short review concerning the palliative treatment of skeletal metastases using 186Re-HEDP. After presenting the dominant ways of 186Re production, special emphasis is given to dosimetry issues while the effect of palliation therapy can be evaluated through the comparison of the absorbed dose in metastatic lesion relatively to the normal bone region. Accurate dose estimation is required taking into account the anatomic individual difference of each patient. For this purpose a patient specific dosimetric model considering metastatic lesions as spherical nodules is introduced. In order to quantify in a representative way the results of palliation treatment, the concept of therapeutic ratios is analyzed.
A 29-Year-Old Female with Progressive Myoclonus and Cognitive Decline
Authors: Taylor D. , Haynes H. R. , Graham A. , Gerhand S. , Kurian K. M.
Published: April 2013

Myoclonic epilepsy with red ragged fibres (MERRF) is a rare mitochondrial disorder presenting with progressive myoclonus, epilepsy, and cognitive decline. Here, the authors present a case of a 29-year-old lady presenting with myoclonus and describe the subsequent investigations that led to a diagnosis of MERRF. In addition, we examine her cognitive decline over a 9-year period, demonstrating a feature commonly seen in mitochondrial cytopathies.
Late Complication of Laparoscopic Sleeve Gastrectomy
Authors: Dakwar Anthony , Assalia Ahmad , Khamaysi Iyad , Kluger Yoram , Mahajna Ahmad
Published: April 2013

Laparoscopic sleeve gastrectomy (LSG) is gaining popularity for the treatment of morbid obesity. It is a simple, low-cost procedure resulting in significant weight loss within a short period of time. LSG is a safe procedure with a low complication rate. The complications encountered nevertheless can result in morbidity and even mortality. The most significant complications are staple-line bleeding, stricture, and staple-line leak. The purpose of this paper is to present a patient who suffered from a staple-line leak presenting 16 months after LSG. Review of the current literature regarding this complication as well as outline of a strategy for the management of post-LSG gastric leaks is suggested.
Gunshot Wound of the Thoracic Aorta with Right Popliteal Artery Embolization: A Case Report of Bullet Embolism with Review of Relevant Literature
Authors: Biswas Saptarshi , Cadot Hadley , Abrol Sunil
Published: April 2013

Bullet embolism is a well-known but relatively uncommon complication of gunshot injuries. Their rarity and the potential lack of early symptoms lead to delays in diagnosis and often in inadequate early management that can potentially result in the loss of a limb or life. We present an interesting case in which a small caliber bullet to the upper anterior abdomen penetrated the thoracic aorta and traveled to the right popliteal artery embolizing the vessel. The exploratory laparotomy failed to locate neither the bullet nor the trajectory resulting in sudden deterioration and eventual death 5 hours into the postoperative period.
Fourier Operational Matrices of Differentiation and Transmission: Introduction and Applications
Authors: Toutounian F. , Tohidi Emran , Kilicman A.
Published: April 2013

This paper introduces Fourier operational matrices of differentiation and transmission for solving high-order linear differential and difference equations with constant coefficients. Moreover, we extend our methods for generalized Pantograph equations with variable coefficients by using Legendre Gauss collocation nodes. In the case of numerical solution of Pantograph equation, an error problem is constructed by means of the residual function and this error problem is solved by using the mentioned collocation scheme. When the exact solution of the problem is not known, the absolute errors can be computed approximately by the numerical solution of the error problem. The reliability and efficiency of the presented approaches are demonstrated by several numerical examples, and also the results are compared with different methods.
Sarcopenic Obesity and Endocrinal Adaptation with Age
Authors: Sakuma Kunihiro , Yamaguchi Akihiko
Published: April 2013

In normal aging, changes in the body composition occur that result in a shift toward decreased muscle mass and increased fat mass. The loss of muscle mass that occurs with aging is termed sarcopenia and is an important cause of frailty, disability, and loss of independence in older adults. Age-related changes in the body composition as well as the increased prevalence of obesity determine a combination of excess weight and reduced muscle mass or strength, recently defined as sarcopenic obesity. Weight gain increases total/abdominal fat, which, in turn, elicits inflammation and fatty infiltration in muscle. Sarcopenic obesity appears to be linked with the upregulation of TNF-α, interleukin (IL)-6, leptin, and myostatin and the downregulation of adiponectin and IL-15. Multiple combined exercise and mild caloric restriction markedly attenuate the symptoms of sarcopenic obesity. Intriguingly, the inhibition of myostatin induced by gene manipulation or neutralizing antibody ameliorates sarcopenic obesity via increased skeletal muscle mass and improved glucose homeostasis. In this review, we describe the possible influence of endocrinal changes with age on sarcopenic obesity.