bluuebunny/crossref_metadata_2025_split huggingface dataset:
In VitroSelection of Variants Resistant to β-Lactams plus β-Lactamase Inhibitors in CTX-M β-Lactamases: Predicting theIn VivoScenario?
Authors: Ripoll Aida , Baquero Fernando , Novais Ângela , Rodríguez-Domínguez Mario J. , Turrientes Maria-Carmen , Cantón Rafael , Galán Juan-Carlos 
Published: July 2011

ABSTRACTCTX-M β-lactamases are the most prevalent group of enzymes within the extended-spectrum β-lactamases (ESBL). The therapeutic options for CTX-M-carrying isolates are scarce, forcing the reexamination of the therapeutic possibilities of β-lactams plus β-lactamase inhibitors (BBLIs). Inhibitor-resistant CTX-M β-lactamases (IR-CTX-M) have not hitherto been described in natural isolates. In this study, 168 cultures of the hypermutagenicEscherichia coliGB20 strain carrying plasmid pBGS18 with differentblaCTX-Mgenes were submitted to parallel experimental evolution assays in the presence of increasing concentrations of a combination of amoxicillin and clavulanate. Fourteen CTX-M β-lactamases belonging to the three most representative clusters (CTX-M-1, -2, and -9) and the two main phenotypes (cefotaxime resistance and cefotaxime-ceftazidime resistance) were studied. Three types of IR-CTX-M mutants were detected, having mutations S130G, K234R, and S237G, which are associated with different resistance patterns. The most frequently recovered mutation was S130G, which conferred the highest resistance levels to BBLIs (reaching 12 μg/ml for amoxicillin-clavulanate and 96 μg/ml for piperacillin-tazobactam when acquired by CTX-M-1 cluster enzymes). The S130G change also provided a clear antagonistic pleiotropy effect, strongly decreasing the enzyme's activity against all cephalosporins tested. A double mutation, S130G L169S, partially restored the resistance against cephalosporins. A complex pattern observed in CTX-M-58, carrying P167S and S130G or K234R changes, conferred ESBL and IR phenotypes simultaneously. The K234R and S237G changes had a smaller effect in providing inhibitor resistance. In summary, IR-CTX-M enzymes might evolve under exposure to BBLIs, and the probability is higher for enzymes belonging to the CTX-M-1 cluster. However, this process could be delayed by antagonistic pleiotropy.
In Vitro
and
In Vivo
Studies of the Utility of Dimethyl and Diethyl Carbaporphyrin Ketals in Treatment of Cutaneous Leishmaniasis
Authors: Taylor Viviana M. , Cedeño David L. , Muñoz Diana L. , Jones Marjorie A. , Lash Timothy D. , Young Alexandra M. , Constantino Manuel H. , Esposito Nicholas , Vélez Iván D. , Robledo Sara M. 
Published: July 2011

ABSTRACT

Carbaporphyrin ketals are porphyrinoid compounds in which a pyrrole ring of a typical porphyrin macrocycle has been replaced by a ketal-substituted indene ring. It was recently demonstrated that these compounds are effective
in vitro
against
Leishmania tarentolae
. Their
in vitro
effectiveness is increased when they are exposed to visible light; they act as photosensitizers capable of mediating the production of reactive oxygen species (ROS). Following on this evidence, the effectiveness and cytotoxicity of the dimethyl and diethyl carbaporphyrin ketals (CKOMe and CKOEt, respectively) were determined
in vitro
using pathogenic
Leishmania
species with and without exposure to visible light (2 and 4 h). The effectiveness against various pathogenic
Leishmania
species was determined to be in a micromolar range. Additionally, the effect of encapsulating the carbaporphyrin ketals in liposome formulations was tested. Liposomal delivery diminished their toxicity, while the effectiveness was enhanced upon exposure to visible light (photodynamic effect). The cytotoxicity levels for human U937 cells and hamster peritoneal macrophages were in the ranges of 0.3 to 9 μM and 7 to 330 μM, respectively. When tested
in vivo
, using a hamster (
Mesocricetus auratus
) model of cutaneous leishmaniasis, CKOMe was active even in the dark, suggesting that the compound, once metabolized in the animal tissue, produces an active ingredient that does not seem to be photosensitive. Reduction in lesion size, histopathologic analyses, and smears confirmed the
in viv
o effectiveness of the compound, since the parasitic load was diminished without noticeable toxic effects.
Genomic Analysis of the Multidrug-Resistant Acinetobacter baumannii Strain MDR-ZJ06 Widely Spread in China
Authors: Zhou Hua , Zhang Tongwu , Yu Dongliang , Pi Borui , Yang Qing , Zhou Jianying , Hu Songnian , Yu Yunsong 
Published: July 2011

ABSTRACT

We previously reported that the multidrug-resistant (MDR)
Acinetobacter baumannii
strain MDR-ZJ06, belonging to European clone II, was widely spread in China. In this study, we report the whole-genome sequence of this clinically important strain. A 38.6-kb AbaR-type genomic resistance island (AbaR22) was identified in MDR-ZJ06. AbaR22 has a structure similar to those of the resistance islands found in
A. baumannii
strains AYE and AB0057, but it contained only a few antibiotic resistance genes. The region of resistant gene accumulation as previously described was not found in AbaR22. In the chromosome of the strain MDR-ZJ06, we identified the gene
bla
oxa-23
in a composite transposon (Tn
2009
). Tn
2009
shared the backbone with other
A. baumannii
transponsons that harbor
bla
oxa-23
, but it was bracketed by two IS
Aba1
elements which were transcribed in the same orientation. MDR-ZJ06 also expressed the
armA
gene on its plasmid pZJ06, and this gene has the same genetic environment as the
armA
gene of the
Enterobacteriaceae
. These results suggest variability of resistance acquisition even in closely related
A. baumannii
strains.
Differential Expression and Characterization of a Member of the Mucin-Associated Surface Protein Family Secreted by Trypanosoma cruzi
Authors: De Pablos Luis Miguel , González Gloria González , Solano Parada Jennifer , Seco Hidalgo Víctor , Díaz Lozano Isabel María , Gómez Samblás María Mercedes , Cruz Bustos Teresa , Osuna Antonio 
Published: July 2011

ABSTRACT

We describe the characterization, purification, expression, and location of a 52-kDa protein secreted during interaction between the metacyclic form of
Trypanosoma cruzi
and its target host cell. The protein, which we have named MASP52, belongs to the family of mucin-associated surface proteins (MASPs). The highest levels of expression of both the protein and mRNA occur during the metacyclic and bloodstream trypomastigote stages, the forms that infect the vertebrate host cells. The protein is located in the plasma membrane and in the flagellar pockets of the epimastigote, metacyclic, and trypomastigote forms and is secreted into the medium at the point of contact between the parasite and the cell membrane, as well as into the host-cell cytosol during the amastigote stage. IgG antibodies specific against a synthetic peptide corresponding to the catalytic zone of MASP52 significantly reduce the parasite's capacity to infect the host cells. Furthermore, when the protein is adsorbed onto inert particles of bentonite and incubated with a nonphagocytic cell culture, the particles are able to induce endocytosis in the cells, which seems to demonstrate that MASP52 plays a role in a process whereby the trypomastigote forms of the parasite invade the host cell.
Serine/Threonine Protein Kinase Stk Is Required for Virulence, Stress Response, and Penicillin Tolerance in Streptococcus pyogenes
Authors: Bugrysheva Julia , Froehlich Barbara J. , Freiberg Jeffrey A. , Scott June R. 
Published: July 2011

ABSTRACTGenes encoding one or more Ser/Thr protein kinases have been identified recently in many bacteria, including one (stk) in the human pathogenStreptococcus pyogenes(group A streptococcus [GAS]). We report that in GAS,stkis required to produce disease in a murine myositis model of infection. Using microarray and quantitative reverse transcription-PCR (qRT-PCR) studies, we found that Stk activates genes for virulence factors, osmoregulation, metabolism of α-glucans, and fatty acid biosynthesis, as well as genes affecting cell wall synthesis. Confirming these transcription studies, we determined that thestkdeletion mutant is more sensitive to osmotic stress and to penicillin than the wild type. We discuss several possible Stk phosphorylation targets that might explain Stk regulation of expression of specific operons and the possible role of Stk in resuscitation from quiescence.
Measuring the load–deformation response of rockfill columns by a full-scale field test on a natural riverbank
Authors: Thiessen Kendall J. , Alfaro Marolo C. , Blatz James A. 
Published: July 2011

A full-scale field test loading of a riverbank stabilized with rockfill columns was used to measure the load–deformation characteristics of the reinforced slope. The test site is located on the natural banks of the Red River in the city of Winnipeg. Rockfill column technology has evolved from granular shear key methods for stabilizing slopes. The relatively weak lacustrine clays are stabilized with compacted columns of limestone rockfill. The columns typically extend through the clay stratum and are anchored in the underlying till. The project involved an extensive site investigation, and soils characterization program in preparation for the field test. Eleven 2.1 m diameter columns were tested by loading the bank with 1920 t of fill. The deformations were measured with standard and in-place inclinometers. The pore-water pressure response of the in situ soils was continuously monitored with vibrating wire piezometers. The results have shown that shear stresses are mobilized along the entire length of the column when subjected to loading, and that complete densification is important in minimizing deformations. This paper discusses the design and construction of the field test and presents the results of the monitoring programs.
Regional variation in wood modulus of elasticity (stiffness) and modulus of rupture (strength) of planted loblolly pine in the United States
Authors: Antony Finto , Jordan Lewis , Schimleck Laurence R. , Clark Alexander , Souter Ray A. , Daniels Richard F. 
Published: July 2011

Modulus of elasticity (MOE), modulus of rupture (MOR), and specific gravity (SG) are important properties for determining the end-use and value of a piece of lumber. This study addressed the variation in MOE, MOR, and SG with physiographic region, tree height, and wood type. Properties were measured from two static bending samples (dimensions 25.4 mm × 25.4 mm × 406.4 mm) representing each wood type (corewood and outerwood) at heights 2.4, 7.3, and 12.2 m from three trees sampled from 135 loblolly pine ( Pinus taeda L.) stands distributed across the natural range of the species. An analysis of variance was conducted to detect the effect of physiographpic region, height, and wood type on each property. Significant regional variation was observed for MOE, MOR, and SG for both wood types with high values in the Gulf and South Atlantic Coastal Plains compared with other regions. A significant height-related trend in MOE, MOR, and SG within a tree was identified; MOE and MOR increased in corewood and decreased in outerwood with height. Maps showing regional variation in MOE and MOR at different heights by wood type were produced and showed significant variation for both properties.
Pocket reflectometry
Authors: Ren Peiran , Wang Jiaping , Snyder John , Tong Xin , Guo Baining 
Published: July 2011

We present a simple, fast solution for reflectance acquisition using tools that fit into a pocket. Our method captures video of a flat target surface from a fixed video camera lit by a hand-held, moving, linear light source. After processing, we obtain an SVBRDF.

We introduce a
BRDF chart
, analogous to a color "checker" chart, which arranges a set of known-BRDF reference tiles over a small card. A sequence of light responses from the chart tiles as well as from points on the target is captured and matched to reconstruct the target's appearance.

We develop a new algorithm for BRDF reconstruction which works directly on these LDR responses, without knowing the light or camera position, or acquiring HDR lighting. It compensates for spatial variation caused by the local (finite distance) camera and light position by warping responses over time to align them to a specular reference. After alignment, we find an optimal linear combination of the Lambertian and purely specular reference responses to match each target point's response. The same weights are then applied to the corresponding (known) reference BRDFs to reconstruct the target point's BRDF. We extend the basic algorithm to also recover varying surface normals by adding two spherical caps for diffuse and specular references to the BRDF chart.
We demonstrate convincing results obtained after less than 30 seconds of data capture, using commercial mobile phone cameras in a casual environment.
Switchable primaries using shiftable layers of color filter arrays
Authors: Sajadi Behzad , Majumder Aditi , Hiwada Kazuhiro , Maki Atsuto , Raskar Ramesh 
Published: July 2011

We present a camera with switchable primaries using shiftable layers of color filter arrays (CFAs). By layering a pair of CMY CFAs in this novel manner we can switch between multiple sets of color primaries (namely RGB, CMY and RGBCY) in the same camera. In contrast to fixed color primaries (e.g. RGB or CMY), which cannot provide optimal image quality for all scene conditions, our camera with switchable primaries provides optimal
color fidelity
and
signal to noise ratio
for multiple scene conditions.

Next, we show that the same concept can be used to layer two RGB CFAs to design a camera with switchable low dynamic range (LDR) and high dynamic range (HDR) modes. Further, we show that such layering can be generalized as a constrained satisfaction problem (CSP) allowing to constrain a large number of parameters (e.g. different operational modes, amount and direction of the shifts, placement of the primaries in the CFA) to provide an optimal solution.
We investigate practical design options for shiftable layering of the CFAs. We demonstrate these by building prototype cameras for both switchable primaries and switchable LDR/HDR modes.
To the best of our knowledge, we present, for the first time, the concept of shiftable layers of CFAs that provides a new degree of freedom in photography where multiple operational modes are available to the user in a single camera for optimizing the picture quality based on the nature of the scene geometry, color and illumination.
Making burr puzzles from 3D models
Authors: Xin Shiqing , Lai Chi-Fu , Fu Chi-Wing , Wong Tien-Tsin , He Ying , Cohen-Or Daniel 
Published: July 2011

A 3D burr puzzle is a 3D model that consists of interlocking pieces with a single-key property. That is, when the puzzle is assembled, all the pieces are notched except one single key component which remains mobile. The intriguing property of the assembled burr puzzle is that it is stable, perfectly interlocked, without glue or screws, etc. Moreover, a burr puzzle consisting of a small number of pieces is still rather difficult to solve since the assembly must follow certain orders while the combinatorial complexity of the puzzle's piece arrangements is extremely high.
In this paper, we generalize the 6-piece orthogonal burr puzzle (a knot) to design and model burr puzzles from 3D models. Given a 3D input model, we first interactively embed a network of knots into the 3D shape. Our method automatically optimizes and arranges the orientation of each knot, and modifies pieces of adjacent knots with an appropriate connection type. Then, following the geometry of the embedded pieces, the entire 3D model is partitioned by splitting the solid while respecting the assembly motion of embedded pieces. The main technical challenge is to enforce the single-key property and ensure the assembly/disassembly remains feasible, as the puzzle pieces in a network of knots are highly interlocked. Lastly, we also present an automated approach to generate the visualizations of the puzzle assembly process.
Echocardiographic Indices Do Not Reliably Track Changes in Left-Sided Filling Pressure in Healthy Subjects or Patients With Heart Failure With Preserved Ejection Fraction
Authors: Bhella Paul S. , Pacini Eric L. , Prasad Anand , Hastings Jeffrey L. , Adams-Huet Beverley , Thomas James D. , Grayburn Paul A. , Levine Benjamin D. 
Published: July 2011

Background—
In select patient populations, Doppler echocardiographic indices may be used to estimate left-sided filling pressures. It is not known, however, whether changes in these indices track changes in left-sided filling pressures within individual healthy subjects or patients with heart failure with preserved ejection fraction (HFpEF). This knowledge is important because it would support, or refute, the serial use of these indices to estimate changes in filling pressures associated with the titration of medical therapy in patients with heart failure.

Methods and Results—

Forty-seven volunteers were enrolled: 11 highly screened elderly outpatients with a clear diagnosis of HFpEF, 24 healthy elderly subjects, and 12 healthy young subjects. Each patient underwent right heart catheterization with simultaneous transthoracic echo. Pulmonary capillary wedge pressure (PCWP) and key echo indices (E/e′ and E/Vp) were measured at two baselines and during 4 preload altering maneuvers: lower body negative pressure −15 mm Hg; lower body negative pressure −30 mm Hg; rapid saline infusion of 10 to 15 mL/kg; and rapid saline infusion of 20 to 30 mL/kg. A random coefficient mixed model regression of PCWP versus E/e′ and PCWP versus E/Vp was performed for (1) a composite of all data points and (2) a composite of all data points within each of the 3 groups. Linear regression analysis was performed for individual subjects. With this protocol, PCWP was manipulated from 0.8 to 28.8 mm Hg. For E/e′, the composite random effects mixed model regression was PCWP=0.58×E/e′+7.02 (
P
<0.001), confirming the weak but significant relationship between these 2 variables. Individual subject linear regression slopes (range, −6.76 to 11.03) and
r
2
(0.00 to 0.94) were highly variable and often very different than those derived for the composite and group regressions. For E/Vp, the composite random coefficient mixed model regression was PCWP=1.95×E/Vp+7.48 (
P
=0.005); once again, individual subject linear regression slopes (range, −16.42 to 25.39) and
r
2
(range, 0.02 to 0.94) were highly variable and often very different than those derived for the composite and group regressions.

Conclusions—
Within individual subjects the noninvasive indices E/e′ and E/Vp do not reliably track changes in left-sided filling pressures as these pressures vary, precluding the use of these techniques in research studies with healthy volunteers or the titration of medical therapy in patients with HFpEF.
A randomized placebo-controlled cross-over study using a low frequency magnetic field in the treatment of fatigue in multiple sclerosis
Authors: de Carvalho Maria Laura Lopes , Motta Roberta , Konrad Giovanna , Battaglia Mario Alberto , Brichetto Giampaolo 
Published: July 2011

Background: Fatigue is one of the most common disabling symptoms in multiple sclerosis (MS). There is growing evidence in the literature for beneficial effects of magnetic fields on different MS symptoms and this has been reported to be beneficial in patients with MS, especially those with fatigue. Objectives: The aim of the study was to assess the effects on primary fatigue with a pulsed systemic low frequency magnetic field by means of clinical scales in a population of MS subjects. Methods: Randomized double-blind cross-over trial with 50 MS subjects with primary fatigue who were recruited among those followed as outpatients at the AISM Rehabilitation Centre, Genova, Italy. Subjects were randomized into two groups: magnetic field group and sham therapy group and evaluated with the Modified Fatigue Impact Scale (MFIS), the Fatigue Severity Scale (FSS), VAS and Time Walking Test 10 meter (TWT10m.) at the time points of the study. Each group received both sham therapy and magnetic field therapy with a wash-out period of 5 months. Subjects were treated for 24 min per session, three times per week, for 8 weeks. Statistical analysis was performed using multivariate analysis. Results: Results showed a statistically significant improvement in MFIS Physical Score for T0 − T1 ( p < 0.05) for TIME but not for TREATMENT and TIME*TREATMENT factors. No statistically significant differences were found for all other parameters considered in the study. Conclusions: Exposure to a low frequency magnetic field, within the parameters of this treatment protocol, has no advantage over sham exposure in reducing the impact of fatigue.
Reduced ribosomal protein gene dosage and p53 activation in low-risk myelodysplastic syndrome
Authors: McGowan Kelly A. , Pang Wendy W. , Bhardwaj Rashmi , Perez Marcelina G. , Pluvinage John V. , Glader Bertil E. , Malek Reem , Mendrysa Susan M. , Weissman Irving L. , Park Christopher Y. , Barsh Gregory S. 
Published: July 2011

AbstractReduced gene dosage of ribosomal protein subunits has been implicated in 5q− myelodysplastic syndrome and Diamond Blackfan anemia, but the cellular and pathophysiologic defects associated with these conditions are enigmatic. Using conditional inactivation of the ribosomal protein S6 gene in laboratory mice, we found that reduced ribosomal protein gene dosage recapitulates cardinal features of the 5q− syndrome, including macrocytic anemia, erythroid hypoplasia, and megakaryocytic dysplasia with thrombocytosis, and that p53 plays a critical role in manifestation of these phenotypes. The blood cell abnormalities are accompanied by a reduction in the number of HSCs, a specific defect in late erythrocyte development, and suggest a disease-specific ontogenetic pathway for megakaryocyte development. Further studies of highly purified HSCs from healthy patients and from those with myelodysplastic syndrome link reduced expression of ribosomal protein genes to decreased RBC maturation and suggest an underlying and common pathophysiologic pathway for additional subtypes of myelodysplastic syndrome.
Sclerotic-type chronic GVHD of the skin: clinical risk factors, laboratory markers, and burden of disease
Authors: Martires Kathryn J. , Baird Kristin , Steinberg Seth M. , Grkovic Lana , Joe Galen O. , Williams Kirsten M. , Mitchell Sandra A. , Datiles Manuel , Hakim Fran T. , Pavletic Steven Z. , Cowen Edward W. 
Published: July 2011

Abstract
Chronic GVHD is one of the most severe complications of allogeneic HSCT. The sclerotic skin manifestations of cGVHD (ScGVHD) result from inflammation and fibrosis of the dermis, subcutaneous tissue, or fascia, leading to significant functional disability. Risk factors and clinical markers associated with ScGVHD remain largely unexamined. By using a single-visit, cross-sectional design, we evaluated 206 patients with cGVHD at the National Institutes of Health. Most patients manifested severe (ie, 63% National Institutes of Health score “severe”), refractory disease (median treatments = 4). ScGVHD was detected in 109 (52.9%) patients. ScGVHD was associated with greater platelet count (P < .001) and C3 (P < .001), and decreased forced vital capacity (P = .013). Total body irradiation (TBI) was associated with development of ScGVHD (P = .002). TBI administered in reduced-intensity conditioning was most strongly associated with ScGVHD (14/15 patients, P < .0001). Patients with ScGVHD had significant impairments of joint range of motion and grip strength (P < .001). Greater body surface area involvement was associated with poorer survival (P = .015). We conclude that TBI, particularly in reduced-intensity regimens, may be an important risk factor for ScGVHD. Widespread skin involvement is associated with significant functional impairment, distressing symptoms, and diminished survival. This trial is registered at http://www.clinicaltrials.gov as NCT00331968.