bluuebunny/crossref_metadata_2025_split huggingface dataset:
Optimizing Paced Ventricular Function in Patients with and without Repaired Congenital Heart Disease by Contractility‐Guided Lead Implant
Authors: KARPAWICH PETER P. , SINGH HARINDER , ZELIN KATHLEEN 
Published: October 2014

BackgroundThis study evaluates the concept of optimizing ventricular pacing in regard to functional cardiac response. Lead implant based on physiologic variables of contractility at various sites was performed in patients with and without congenital heart disease (CHD). Since right ventricular apical pacing may adversely alter contractility and myocellular function, septal and outflow tract pacing have been advocated. However, there are few studies in the young and essentially none in those with CHD.MethodsA total of 113 consecutive patients with and without repaired CHD, aged two to 51 (median 16), some with preexisting epicardial pacemakers, underwent transvenous pacemaker implant using standard sensing/pacing indices plus measurements of pressures, QRS, and contractility responses at each of five predefined potential ventricular implant sites: apex, inflow‐, low‐, mid‐, and infundibular/outflow‐septal with each patient serving as his/her own control. Implant was at the site of best contractility with active‐fixation, low‐threshold steroid‐eluting leads.ResultsMeasured contractility indices varied up to 31% (mean 12%) between sites per patient. Septal regions (mid‐, inflow‐, and low‐) were associated with the most optimal and right ventricular epicardial showed the worst contractility (P < 0.05) responses. Apex was optimal in some CHD patients. Threshold and sensing were comparable up to 11 years (mean 7) postimplant regardless of septal site.ConclusionThere is no single “sweet spot” for optimal ventricular pacing, and the best implant sites are patient and CHD variable. Current lead designs ensure chronic stability/performance regardless of site. Proactive contractility‐guided pacing implant can optimize chronic paced ventricular function.
Phosphorus recycling in photorespiration maintains high photosynthetic capacity in woody species
Authors: ELLSWORTH DAVID S. , CROUS KRISTINE Y. , LAMBERS HANS , COOKE JULIA 
Published: October 2014

AbstractLeaf photosynthetic CO2 responses can provide insight into how major nutrients, such as phosphorus (P), constrain leaf CO2 assimilation rates (Anet). However, triose‐phosphate limitations are rarely employed in the classic photosynthesis model and it is uncertain as to what extent these limitations occur in field situations. In contrast to predictions from biochemical theory of photosynthesis, we found consistent evidence in the field of lower Anet in high [CO2] and low [O2] than at ambient [O2]. For 10 species of trees and shrubs across a range of soil P availability in Australia, none of them showed a positive response of Anet at saturating [CO2] (i.e. Amax) to 2 kPa O2. Three species showed >20% reductions in Amax in low [O2], a phenomenon potentially explained by orthophosphate (Pi) savings during photorespiration. These species, with largest photosynthetic capacity and Pi > 2 mmol P m−2, rely the most on additional Pi made available from photorespiration rather than species growing in P‐impoverished soils. The results suggest that rarely used adjustments to a biochemical photosynthesis model are useful for predicting Amax and give insight into the biochemical limitations of photosynthesis rates at a range of leaf P concentrations. Phosphate limitations to photosynthetic capacity are likely more common in the field than previously considered.
Single‐center experience in pediatric renal transplantation using thymoglobulin induction and steroid minimization
Authors: Warejko Jillian K. , Hmiel S. Paul 
Published: October 2014

AbstractOur center has offered thymoglobulin induction with steroid minimization to our pediatric renal transplant patients for the last 10 yr. Steroid minimization or avoidance has shown favorable results in survival, kidney function, and growth in previous studies of pediatric patients. We report our experience with this protocol over the past 10 yr with respect to patient/graft survival, acute rejection episodes, renal function, linear growth, bone density, cardiovascular risk factors, and opportunistic infections. A retrospective chart review was performed for pediatric renal transplant patients on the steroid‐minimized protocol between January 2002 and December 2011 on an intention to treat basis. Patient demographics, height, weight, serum creatinine, iGFR, biopsies, and survival data were collected. Height and weight z‐scores were calculated with EpiInfo 7, using the CDC 2000 growth charts. Survival was calculated using Kaplan–Meier analysis. eGFR was calculated using the original and modified Schwartz equations. Forty‐four pediatric patients were identified, aged 13 months to 19 yr. Five‐yr survival was 95.5% for males and 94.4% for females. Only five patients had biopsy‐proven ACR, two of which were at more than 12 months post‐transplantation. Height delta z‐scores from transplant to one, three, and five yr were 0.34, 0.38, and 0.79, respectively. Weight delta z‐scores from transplant to one, three, and five yr were 0.87, 0.79, and 0.84, respectively. Mean original Schwartz eGFR was 84.3 ± 15.8 mL/min/1.73 m2, modified Schwartz eGFR was 59.3 ± 11.5 mL/min/1.73 m2, and iGFR was 64.2 ± 8.5 mL/min/1.73 m2 at three yr. Of 18 subjects who had a bone density exam, none had a z‐score less than −2 on DEXA exam at one‐yr post‐transplantation. Fifty‐one percent of patients were on antihypertensives at the time of transplant compared with 43% at one‐yr post‐transplantation. Three yr post‐transplantation, the average LDL was <100 mg/dL, and average total cholesterol was <200 mg/dL. There were no clinical episodes of EBV or CMV infection. A steroid‐minimized protocol with thymoglobulin induction is safe and provides favorable improvement in linear growth, stable graft function, stable or improved cardiovascular risk factors, and normal bone density in pediatric renal transplant patients.
Assessing Characteristic Scales Using Wavelets
Authors: Keim Michael J. , Percival Donald B. 
Published: October 2014

SummaryCharacteristic scale is a notion that pervades the geophysical sciences, but it has no widely accepted precise definition. Motivated by the facts that the wavelet transform decomposes a time series into coefficients that are associated with different scales and that the variance of these coefficients (the so-called wavelet variance) decomposes the variance of the time series across scales, the paper proposes a definition for characteristic scale in terms of peaks in plots of the wavelet variance versus scale. After presenting basic theory for wavelet-based characteristic scales, a natural estimator for these scales is considered. Large sample theory for this estimator permits the construction of confidence intervals for a true unknown characteristic scale. Computer experiments are presented that demonstrate the efficacy of the large sample theory for finite sample sizes. Characteristic scale estimates are calculated for medium multiyear Arctic sea ice, global temperature records, coherent structures in river flows and the Madden–Julian oscillation in an atmospheric time series.
Bilateral lenticular Encephalitozoon cuniculi infection in a snow leopard (Panthera uncia)
Authors: Scurrell Emma Jane , Holding Ellen , Hopper Jane , Denk Daniela , Fuchs‐Baumgartinger Andrea , Silbermayr Katja , Nell Barbara 
Published: October 2014

AbstractBilateral phacoclastic uveitis caused by lenticular infection with Encephalitozoon cuniculi is described in a snow leopard. The diagnosis was made on histopathological and immunohistological examination of both eyes submitted after postmortem examination. There was a positive antibody titer for E. cuniculi (1:320). Polymerase chain reaction (PCR) and sequence analysis of formalin‐fixed, paraffin‐embedded ocular tissue detected the DNA of E. cuniculi, strain III. No other systemic lesions attributable to the E. cuniculi infection were identified.
Limbal squamous cell carcinoma inHaflinger horses
Authors: Lassaline Mary , Cranford Taryn L. , Latimer Claire A. , Bellone Rebecca R. 
Published: October 2014

AbstractObjectiveTo describe the prevalence ofLSCCin Haflinger horses and to analyze affected horses' pedigrees investigating the genetic mode of inheritance.AnimalsFifteen horses met inclusion criterion of (i) being of the Haflinger breed, as confirmed by North American Haflinger Registry pedigree and (ii) being diagnosed withLSCC, as confirmed by clinical examination by a veterinary ophthalmologist or by histopathology. Pedigrees could not be obtained for four additional horses diagnosed withLSCCthat had been identified as Haflingers.ProcedureRetrospective medical record review of all 19 horses was used to determine patient sex and age at diagnosis. The four‐generation pedigrees available for 15 of the horses were used to perform pedigree analysis.ResultsAverage age of 19 Haflingers at diagnosis withLSCCwas 8.7 years. Eleven were males and eight were females. Thirteen of 15 affected horses for whom pedigrees were available shared a common ancestor within five generations, and all 15 shared a common ancestor from the A stallion line in the breed pedigree. Pedigree analysis identified a common sire of two of the affected male horses. Clinical examination of this sire that had no history ofLSCCshowed no current clinical signs ofLSCC, suggesting an autosomal recessive mode of inheritance.ConclusionsHaflingers may be over‐represented amongst horses withLSCCand may be diagnosed at a younger age than other breeds. Affected Haflingers appear closely related, suggesting a possible heritable basis forLSCC. The genetic basis forLSCCwill be investigated further by aGWASapproach.
End‐to‐end test of spatial accuracy in Gamma Knife treatments for trigeminal neuralgia a)
Authors: Brezovich Ivan A. , Wu Xingen , Duan Jun , Popple Richard A. , Shen Sui , Benhabib Sidi , Huang Mi , Christian Dobelbower M. , Fisher Winfield S. 
Published: October 2014

Purpose:Spatial accuracy is most crucial when small targets like the trigeminal nerve are treated. Although current quality assurance procedures typically verify that individual apparatus, like the MRI scanner, CT scanner, Gamma Knife, etc., are meeting specifications, the cumulative error of all equipment and procedures combined may exceed safe margins. This study uses an end‐to‐end approach to assess the overall targeting errors that may have occurred in individual patients previously treated for trigeminal neuralgia.Methods:The trigeminal nerve is simulated by a 3 mm long, 3.175 mm (1/8 in.) diameter MRI‐contrast filled cavity embedded within a PMMA plastic capsule. The capsule is positioned within the head frame such that the location of the cavity matches the Gamma Knife coordinates of an arbitrarily chosen, previously treated patient. Gafchromic EBT2 film is placed at the center of the cavity in coronal and sagittal orientations. The films are marked with a pinprick to identify the cavity center. Treatments are planned for radiation delivery with 4 mm collimators according to MRI and CT scans using the clinical localizer boxes and acquisition protocols. Shots are planned so that the 50% isodose surface encompasses the cavity. Following irradiation, the films are scanned and analyzed. Targeting errors are defined as the distance between the pinprick, which represents the intended target, and the centroid of the 50% isodose line, which is the center of the radiation field that was actually delivered.Results:Averaged over ten patient simulations, targeting errors along the x, y, and z coordinates (patient's left‐to‐right, posterior‐to‐anterior, and head‐to‐foot) were, respectively, −0.060 ± 0.363, −0.350 ± 0.253, and 0.348 ± 0.204 mm when MRI was used for treatment planning. Planning according to CT exhibited generally smaller errors, namely, 0.109 ± 0.167, −0.191 ± 0.144, and 0.211 ± 0.094 mm. The largest errors along individual axes in MRI‐ and CT‐planned treatments were, respectively, −0.761 mm in the y‐direction and 0.428 mm in the x‐direction, well within safe limits.Conclusions:The highly accurate dose delivery was possible because the Gamma Knife, MRI scanner, and other equipment performed within tight limits and scans were acquired using the thinnest slices and smallest pixel sizes available. Had the individual devices performed only near the limits of their specifications, the cumulative error could have left parts of the trigeminal nerve undertreated. The presented end‐to‐end test gives assurance that patients had received the expected high quality treatment. End‐to‐end tests should become part of clinical practice.
The effect of amorphous selenium detector thickness on dual‐energy digital breast imaging
Authors: Hu Yue‐Houng , Zhao Wei 
Published: October 2014

Purpose:Contrast enhanced (CE) imaging techniques for both planar digital mammography (DM) and three‐dimensional (3D) digital breast tomosynthesis (DBT) applications requires x‐ray photon energies higher than the k‐edge of iodine (33.2 keV). As a result, x‐ray tube potentials much higher (>40 kVp) than those typical for screening mammography must be utilized. Amorphous selenium (a‐Se) based direct conversion flat‐panel imagers (FPI) have been widely used in DM and DBT imaging systems. The a‐Se layer is typically 200 μm thick with quantum detective efficiency (QDE) >87% for x‐ray energies below 26 keV. However, QDE decreases substantially above this energy. To improve the object detectability of either CE‐DM or CE‐DBT, it may be advantageous to increase the thickness (dSe) of the a‐Se layer. Increasing the dSe will improve the detective quantum efficiency (DQE) at the higher energies used in CE imaging. However, because most DBT systems are designed with partially isocentric geometries, where the gantry moves about a stationary detector, the oblique entry of x‐rays will introduce additional blur to the system. The present investigation quantifies the effect of a‐Se thickness on imaging performance for both CE‐DM and CE‐DBT, discussing the effects of improving photon absorption and blurring from oblique entry of x‐rays.Methods:In this paper, a cascaded linear system model (CLSM) was used to investigate the effect of dSe on the imaging performance (i.e., MTF, NPS, and DQE) of FPI in CE‐DM and CE‐DBT. The results from the model are used to calculate the ideal observer signal‐to‐noise ratio, d′, which is used as a figure‐of‐merit to determine the total effect of increasing dSe for CE‐DM and CE‐DBT.Results:The results of the CLSM show that increasing dSe causes a substantial increase in QDE at the high energies used in CE‐DM. However, at the oblique projection angles used in DBT, the increased length of penetration through a‐Se introduces additional image blur. The reduced MTF and DQE at high spatial frequencies lead to reduced two‐dimensional d′. These losses in projection image resolution may subsequently result in a decrease in the 3D d′, but the degree of which is largely dependent on the DBT reconstruction algorithm. For a filtered backprojection (FBP) algorithm with spectral apodization and slice‐thickness filters, which dominate the blur for reconstructed images at oblique angles, the effect of oblique entry of x‐rays on 3D d′ is minimal. Thus, increasing dSe results in an improvement in d′ for both CE‐DM and CE‐DBT with typical FBP reconstruction parameters.Conclusions:Increased dSe improves CE breast imaging performance by increasing QDE of detectors at higher energies, e.g., 49 kVp. Although there is additional blur in the oblique angled projections of a DBT scan, the overall 3D d′ for DBT is not degraded because the dominant source blur at these angles results from the reconstruction filters of the employed FBP algorithm.
A method to estimate the fractional fat volume within a ROI of a breast biopsy for WAXS applications: Animal tissue evaluation
Authors: Tang Robert Y. , McDonald Nancy , Laamanen Curtis , LeClair Robert J. 
Published: October 2014

Purpose:To develop a method to estimate the mean fractional volume of fat () within a region of interest (ROI) of a tissue sample for wide‐angle x‐ray scatter (WAXS) applications. A scatter signal from the ROI was obtained and use of in a WAXS fat subtraction model provided a way to estimate the differential linear scattering coefficient μs of the remaining fatless tissue.Methods:The efficacy of the method was tested using animal tissue from a local butcher shop. Formalin fixed samples, 5 mm in diameter 4 mm thick, were prepared. The two main tissue types were fat and meat (fibrous). Pure as well as composite samples consisting of a mixture of the two tissue types were analyzed. For the latter samples, νfat for the tissue columns of interest were extracted from corresponding pixels in CCD digital x‐ray images using a calibration curve. The means were then calculated for use in a WAXS fat subtraction model. For the WAXS measurements, the samples were interrogated with a 2.7 mm diameter 50 kV beam and the 6° scattered photons were detected with a CdTe detector subtending a solid angle of 7.75 × 10−5 sr. Using the scatter spectrum, an estimate of the incident spectrum, and a scatter model, μs was determined for the tissue in the ROI. For the composite samples, a WAXS fat subtraction model was used to estimate the μs of the fibrous tissue in the ROI. This signal was compared to μs of fibrous tissue obtained using a pure fibrous sample.Results:For chicken and beef composites, and 0.32 ± 0.05, respectively. The subtractions of these fat components from the WAXS composite signals provided estimates of μs for chicken and beef fibrous tissue. The differences between the estimates and μs of fibrous obtained with a pure sample were calculated as a function of the momentum transfer x. A t‐test showed that the mean of the differences did not vary from zero in a statistically significant way thereby validating the methods.Conclusions:The methodology to estimate in a ROI of a tissue sample via CCD x‐ray imaging was quantitatively accurate. The WAXS fat subtraction model allowed μs of fibrous tissue to be obtained from a ROI which had some fat. The fat estimation method coupled with the WAXS models can be used to compare μs coefficients of fibroglandular and cancerous breast tissue.
In Vitro
Activity of wALADin Benzimidazoles against Different Life Cycle Stages of Plasmodium Parasites
Authors: Lentz Christian S. , Sattler Julia M. , Fendler Martina , Gottwalt Simon , Halls Victoria S. , Strassel Silke , Arriens Sandra , Hannam Jeffrey S. , Specht Sabine , Famulok Michael , Mueller Ann-Kristin , Hoerauf Achim , Pfarr Kenneth M. 
Published: October 2014

ABSTRACT

wALADin1 benzimidazoles are specific inhibitors of δ-aminolevulinic acid dehydratase from
Wolbachia
endobacteria of filarial nematodes. We report that wALADin1 and two derivatives killed blood stage
Plasmodium falciparum
in vitro
(50% inhibitory concentrations, 39, 7.7, and 12.8 μM, respectively). One of these derivatives inhibited gliding motility of
Plasmodium berghei
ANKA infectious sporozoites with nanomolar affinity and blocked invasion into hepatocytes but did not affect intrahepatocytic replication. Hence, wALADin1 benzimidazoles are tools to study gliding motility and potential antiplasmodial drug candidates.
Impact on Resistance of the Use of Therapeutically Equivalent Generics: the Case of Ciprofloxacin
Authors: Rodriguez Carlos A. , Agudelo Maria , Zuluaga Andres F. , Vesga Omar 
Published: October 2014

ABSTRACT

Therapeutic nonequivalence of generic antibiotics may lead to treatment failure and enrichment of resistance. However, there has been no demonstration that an equivalent generic displays the same resistance selection profile as the innovator drug. We aimed to test this hypothesis with five generic versions of ciprofloxacin by assessing their pharmaceutical equivalence with microbiological assays and their efficacy against
Pseudomonas aeruginosa
PAO1 in the neutropenic murine thigh infection model. One equivalent generic was selected for analysis by high-pressure liquid chromatography–tandem mass spectrometry (LC-MS/MS), to confirm chemical identity, and resistance selection experiments in a hollow-fiber (HF) system simulating two clinical dosing regimens. Total and resistant populations were measured, and the MICs of the resistant cells with and without an efflux pump inhibitor were determined. LC-MS/MS found no differences between products, and the innovator and the generic selected resistance with the same magnitude and mechanism after 7 days of treatment in the HF system, supporting the fact that a generic with demonstrated equivalence
in vivo
is also equivalent regarding resistance selection.
Mass Balance, Metabolite Profile, and
In Vitro-In Vivo
Comparison of Clearance Pathways of Deleobuvir, a Hepatitis C Virus Polymerase Inhibitor
Authors: Chen Lin-Zhi , Sabo John P. , Philip Elsy , Rowland Lois , Mao Yan , Latli Bachir , Ramsden Diane , Mandarino Debra A. , Sane Rucha S. 
Published: October 2014

ABSTRACT

The pharmacokinetics, mass balance, and metabolism of deleobuvir, a hepatitis C virus (HCV) polymerase inhibitor, were assessed in healthy subjects following a single oral dose of 800 mg of [
14
C]deleobuvir (100 μCi). The overall recovery of radioactivity was 95.2%, with 95.1% recovered from feces. Deleobuvir had moderate to high clearance, and the half-life of deleobuvir and radioactivity in plasma were ∼3 h, indicating that there were no metabolites with half-lives significantly longer than that of the parent. The most frequently reported adverse events (in 6 of 12 subjects) were gastrointestinal disorders. Two major metabolites of deleobuvir were identified in plasma: an acyl glucuronide and an alkene reduction metabolite formed in the gastrointestinal (GI) tract by gut bacteria (CD 6168), representing ∼20% and 15% of the total drug-related material, respectively. Deleobuvir and CD 6168 were the main components in the fecal samples, each representing ∼30 to 35% of the dose. The majority of the remaining radioactivity found in the fecal samples (∼21% of the dose) was accounted for by three metabolites in which deleobuvir underwent both alkene reduction and monohydroxylation. In fresh human hepatocytes that form biliary canaliculi in sandwich cultures, the biliary excretion for these excretory metabolites was markedly higher than that for deleobuvir and CD 6168, implying that rapid biliary elimination upon hepatic formation may underlie the absence of these metabolites in circulation. The low
in vitro
clearance was not predictive of the observed
in vivo
clearance, likely because major deleobuvir biotransformation occurred by non-CYP450-mediated enzymes that are not well represented in hepatocyte-based
in vitro
models.
Molecular Characterization of
bla
NDM-5
Carried on an IncFII Plasmid in an Escherichia coli Isolate from a Nontraveler Patient in Spain
Authors: Pitart Cristina , Solé Mar , Roca Ignasi , Román Angely , Moreno Asunción , Vila Jordi , Marco Francesc 
Published: October 2014

ABSTRACT

A carbapenem-resistant
Escherichia coli
isolate (sequence type 448 [ST448]) was recovered from a urine culture of a female patient with no recent record of traveling. PCR screening identified the presence of
bla
NDM-5
,
bla
TEM-1
,
bla
OXA-1
,
bla
CMY-42
, and
rmtB. bla
NDM-5
was carried in a conjugative IncFII-type plasmid (90 kb) together with
bla
TEM-1
and
rmtB
. The genetic environment of
bla
NDM-5
showed a structure similar to those of pMC-NDM and pGUE-NDM, identified in Poland and France in
E. coli
of African and Indian origin, respectively.