bluuebunny/crossref_metadata_2025_split huggingface dataset:
The retinoic acid‐producing capacity of gut dendritic cells and macrophages is reduced during persistent T. muris infection
Authors: Hurst R. J. M. , Else K. J. 
Published: March 2013

SummaryTrichuris muris is an intestinal nematode that invades the colonic epithelium triggering a mucosal inflammation. Vitamin A and its active metabolite retinoic acid are strongly linked with the modulation of gut immune responses. Here, we describe the temporal changes in the expression of aldehyde dehydrogenase (ALDH) enzymes, responsible for converting dietary‐absorbed vitamin A into the immuno‐modulatory retinoic acid in lamina propria leucocytes post‐infection. We show that ALDH enzymes are expressed by both colonic macrophages and dendritic cells. Further, during an on‐going T. muris infection, ALDH expression is repressed from uninfected levels and only recovers to normal levels following expulsion of the parasite. These results suggest that local regulation of cellular levels of retinoic acid is an important component of infection‐driven inflammation.
Bacterial lipid modification enhances immunoprophylaxis of filarial abundant larval transcript‐2 protein in Mastomys model
Authors: Sharmila S. , Christiana I. , Kiran P. , Reddy M. V. R. , Sankaran K. , Kaliraj P. 
Published: March 2013

SummaryAs in many other parasitic diseases, efficacious vaccine for lymphatic filariasis has been elusive for want of new approaches leaving billions of people either debilitated or at risk. With multiple B‐ and T‐cell epitopes, the abundant larval transcript‐2 (ALT‐2) of the filarial worm, Brugia malayi, has been shown to be a promising immunoprophylactic target. To enhance its efficacy, it was lipid modified using our recently developed protein engineering tool, which then offered 30% more immunoprotection (49 vs. 79%) in Mastomys coucha model. Sustained high levels of IFN‐γ (about 100 times) and high antibody titres (10‐fold) elicited by lipid‐modified ALT‐2, as compared to the native form, indicated the maintenance of Th1/Th2 balance that is impaired in filariasis. Thus, this study provides the basis for developing efficacious vaccines for filariasis and other parasitic diseases by exploiting bacterial lipid modification.
Power and PulsedDoppler Evaluation of Prostatic Artery Blood Flow in Normal and Benign Prostatic Hyperplasia–Affected Dogs
Authors: Zelli R , Orlandi R , Troisi A , Cardinali L , Polisca A 
Published: March 2013

ContentsThis study was carried out with the objectives to test the differences in the haemodynamic characteristics of the prostatic artery in normal and benign prostatic hyperplasia (BPH)–affected dogs usingDoppler ultrasonography. In sixteen male German shepherd dogs, prostatic volume was detected and prostatic biopsy was performed. The prostatic artery blood flow parameters determined were as follows: peak systolic velocity (PSV), end diastolic velocity (EDV), Resistive Index (RI) and Pulsatility Index. The powerDoppler mode was used for colour flow mapping of the prostatic artery. InPWmode at marginal locations, the waveforms recorded showed a continuous pattern typical of the high‐resistance vessels, while in subcapsular locations, the waveforms recorded were continuous characteristic of the low‐resistance vessel. Peak systolic velocity and EDV in both locations were significantly higher in BPH group (p < 0.001) than normal group (p < 0.05). Pixel number in BPH group in both locations was significantly higher (p < 0.05) compared to the normal group. This study shows thatDoppler ultrasonography represents a valid and non‐invasive method for the characterization of the blood flow in the prostatic artery in dogs affected with BPH. Moreover, statistically significant differences of blood flow velocities in prostatic artery in normal and BPH‐affected dogs were detected. The RI was not able to differentiate normal dogs from dogs affected byBPHand therefore is not a parameter usable for diagnostic purposes, while PowerDoppler could represent an additional diagnostic tool.
BrachyView: Proof‐of‐principle of a novel in‐body gamma camera for low dose‐rate prostate brachytherapy
Authors: Petasecca M. , Loo K. J. , Safavi‐Naeini M. , Han Z. , Metcalfe P. E. , Meikle S. , Pospisil S. , Jakubek J. , Bucci J. A. , Zaider M. , Lerch M. L. F. , Qi Y. , Rosenfeld A. B. 
Published: March 2013

Purpose:The conformity of the achieved dose distribution to the treatment plan strongly correlates with the accuracy of seed implantation in a prostate brachytherapy treatment procedure. Incorrect seed placement leads to both short and long term complications, including urethral and rectal toxicity. The authors present BrachyView, a novel concept of a fast intraoperative treatment planning system, to provide real‐time seed placement information based on in‐body gamma camera data. BrachyView combines the high spatial resolution of a pixellated silicon detector (Medipix2) with the volumetric information acquired by a transrectal ultrasound (TRUS). The two systems will be embedded in the same probe so as to provide anatomically correct seed positions for intraoperative planning and postimplant dosimetry. Dosimetric calculations are based on the TG‐43 method using the real position of the seeds. The purpose of this paper is to demonstrate the feasibility of BrachyView using the Medipix2 pixel detector and a pinhole collimator to reconstruct the real‐time 3D position of low dose‐rate brachytherapy seeds in a phantom.Methods:BrachyView incorporates three Medipix2 detectors coupled to a multipinhole collimator. Three‐dimensionally triangulated seed positions from multiple planar images are used to determine the seed placement in a PMMA prostate phantom in real time. MATLAB codes were used to test the reconstruction method and to optimize the device geometry.Results:The results presented in this paper show a 3D position reconstruction accuracy of the seed in the range of 0.5–3 mm for a 10–60 mm seed‐to‐detector distance interval (Z direction), respectively. The BrachyView system also demonstrates a spatial resolution of 0.25 mm in the XY plane for sources at 10 mm distance from Medipix2 detector plane, comparable to the theoretical value calculated for an equivalent gamma camera arrangement. The authors successfully demonstrated the capability of BrachyView for real‐time imaging (using a 3 s data acquisition time) of different brachytherapy seed configurations (with an activity of 0.05 U) throughout a 60 × 60 × 60 mm3 Perspex prostate phantom.Conclusions:The newly developed miniature gamma camera component of BrachyView, with its high spatial resolution and real time capability, allows accurate 3D localization of seeds in a prostate phantom. Combination of the gamma camera with TRUS in a single probe will complete the BrachyView system.
Performance of a high‐sensitivity dedicated cardiac SPECT scanner for striatal uptake quantification in the brain based on analysis of projection data
Authors: Park Mi‐Ae , Moore Stephen C. , Müller Stefan P. , McQuaid Sarah J. , Kijewski Marie Foley 
Published: March 2013

Purpose:The authors have previously reported the advantages of high‐sensitivity single‐photon emission computed tomography (SPECT) systems for imaging structures located deep inside the brain. DaTscan (Isoflupane I‐123) is a dopamine transporter (DaT) imaging agent that has shown potential for early detection of Parkinson disease (PD), as well as for monitoring progression of the disease. Realizing the full potential of DaTscan requires efficient estimation of striatal uptake from SPECT images. They have evaluated two SPECT systems, a conventional dual‐head gamma camera with low‐energy high‐resolution collimators (conventional) and a dedicated high‐sensitivity multidetector cardiac imaging system (dedicated) for imaging tasks related to PD.Methods:Cramer–Rao bounds (CRB) on precision of estimates of striatal and background activity concentrations were calculated from high‐count, separate acquisitions of the compartments (right striata, left striata, background) of a striatal phantom. CRB on striatal and background activity concentration were calculated from essentially noise‐free projection datasets, synthesized by scaling and summing the compartment projection datasets, for a range of total detected counts. They also calculated variances of estimates of specific‐to‐nonspecific binding ratios (BR) and asymmetry indices from these values using propagation of error analysis, as well as the precision of measuring changes in BR on the order of the average annual decline in early PD.Results:Under typical clinical conditions, the conventional camera detected 2 M counts while the dedicated camera detected 12 M counts. Assuming a normal BR of 5, the standard deviation of BR estimates was 0.042 and 0.021 for the conventional and dedicated system, respectively. For an 8% decrease to BR = 4.6, the signal‐to‐noise ratio were 6.8 (conventional) and 13.3 (dedicated); for a 5% decrease, they were 4.2 (conventional) and 8.3 (dedicated).Conclusions:This implies that PD can be detected earlier with the dedicated system than with the conventional system; therefore, earlier identification of PD progression should be possible with the high‐sensitivity dedicated SPECT camera.
Dose response of selected ion chambers in applied homogeneous transverse and longitudinal magnetic fields
Authors: Reynolds M. , Fallone B. G. , Rathee S. 
Published: March 2013

Purpose:The magnetic fields of an integrated MR‐Linac system will alter the paths of electrons that produce ions in the ionization chambers. The dose response of selected ion chambers is evaluated in the presence of varying transverse and longitudinal magnetic fields. The investigation is useful in calibration of therapeutic x‐ray beams associated with MR‐Linac systems.Methods:The Monte Carlo code PENELOPE was used to model the irradiation of NE2571, and PR06C ionization chambers in the presence of a transverse and longitudinal (with respect to the photon beam) magnetic fields of varying magnitude. The long axis of each chamber was simulated both parallel and perpendicular to the incident photon beam for each magnetic field case. The dose deposited in each chamber for each case was compared to the case with zero magnetic field by means of a ratio. The PR06C chamber's response was measured in the presence of a transverse magnetic field with field strengths ranging from 0.0 to 0.2 T to compare to simulated results.Results:The simulations and measured data show that in the presence of a transverse magnetic field there is a considerable dose response (maximum of 11% near 1.0 T in the ion chambers investigated, which depends on the magnitude of magnetic field, and relative orientation of the magnetic field, radiation beam, and ion chamber. Measurements made with the PR06C chamber verify these results in the region of measurement. In contrast, a longitudinal magnetic field produces only a slight increase in dose response (2% at 1.5 T) that rises slowly with increasing magnetic field and is seemingly independent of chamber orientation. Response trends were similar for the two ion chambers and relative orientations considered, but slight variations are present from chamber to chamber.Conclusions:Care must be taken when making ion chamber measurements in a transverse magnetic field. Ion chamber responses vary not only with transverse field strength, but with chamber orientation and type, and can be considerable. Longitudinal magnetic fields influence ion chamber responses relatively little (2% at 1.5 T), and only at field strengths in excess of 1.0 T.
Host Exopolysaccharide Quantity and Composition Impact Erwinia amylovora Bacteriophage Pathogenesis
Authors: Roach Dwayne R. , Sjaarda David R. , Castle Alan J. , Svircev Antonet M. 
Published: March 2013

ABSTRACTErwinia amylovorabacteriophages (phages) belonging to theMyoviridaeandPodoviridaefamilies demonstrated a preference for either high-exopolysaccharide-producing (HEP) or low-exopolysaccharide-producing (LEP) bacterial hosts when grown on artificial medium without or with sugar supplementation.Myoviridaephages produced clear plaques on LEP hosts and turbid plaques on HEP hosts. The reverse preference was demonstrated by mostPodoviridaephages, where clear plaques were seen on HEP hosts. Efficiency of plating (EOP) was determined by comparing phage growth on the original isolation host to the that on the LEP or HEP host. Nine of 10Myoviridaephages showed highest EOPs on LEP hosts, and 8 of 11Podoviridaephages had highest EOPs on HEP hosts. Increasing the production of EPS on sugar-supplemented medium or decreasing production by knocking out the synthesis of amylovoran or levan, the two EPSs produced byE. amylovora, indicated that these components play crucial roles in phage infection. Amylovoran was virtually essential for proliferation of mostPodoviridaephages when phage population growth was compared to the wild type. Decreased levan production resulted in a significant reduction of progeny from phages in theMyoviridaefamily. Thus,Podoviridaephages are adapted to hosts that produce high levels of exopolysaccharides and are dependent on host-produced amylovoran for pathogenesis.Myoviridaephages are adapted to hosts that produce lower levels of exopolysaccharides and host-produced levan.
Characterization of a Lactobacillus gasseri JCM 1131
T
Lipoteichoic Acid with a Novel Glycolipid Anchor Structure
Authors: Shiraishi Tsukasa , Yokota Shin-ichi , Morita Naoki , Fukiya Satoru , Tomita Satoru , Tanaka Naoto , Okada Sanae , Yokota Atsushi 
Published: March 2013

ABSTRACT

We determined the chemical structure of lipoteichoic acid (LTA) from
Lactobacillus gasseri
JCM 1131
T
. The repeating unit was comprised of glycerolphosphate and 2-alanylglycerolphosphate. The glycolipid anchor was tetrahexosylglycerol with two or three acyl groups. To our knowledge, this is the first demonstration of a tetrahexose structure in an LTA glycolipid anchor.
Insights into the Assembly of the Alginate Biosynthesis Machinery in Pseudomonas aeruginosa
Authors: Rehman Zahid U. , Wang Yajie , Moradali M. Fata , Hay Iain D. , Rehm Bernd H. A. 
Published: March 2013

ABSTRACT

Pseudomonas aeruginosa
is an opportunistic pathogen of particular significance to cystic fibrosis patients. This bacterium produces the exopolysaccharide alginate, which is an indicator of poor prognosis for these patients. The proteins required for alginate polymerization and secretion are encoded by genes organized in a single operon; however, the existence of internal promoters has been reported. It has been proposed that these proteins form a multiprotein complex which extends from the inner to outer membrane. Here, experimental evidence supporting such a multiprotein complex was obtained via mutual stability analysis, pulldown assays, and coimmunoprecipitation. The impact of the absence of single proteins or subunits on this multiprotein complex, i.e., on the stability of potentially interacting proteins, as well as on alginate production was investigated. Deletion of
algK
in an alginate-overproducing strain, PDO300, interfered with the polymerization of alginate, suggesting that in the absence of AlgK, the polymerase and copolymerase subunits, Alg8 and Alg44, are destabilized. Based on mutual stability analysis, interactions between AlgE (outer membrane), AlgK (periplasm), AlgX (periplasm), Alg44 (inner membrane), Alg8 (inner membrane), and AlgG (periplasm) were proposed. Coimmunoprecipitation using a FLAG-tagged variant of AlgE further demonstrated its interaction with AlgK. Pulldown assays using histidine-tagged AlgK showed that AlgK interacts with AlgX, which in turn was also copurified with histidine-tagged Alg44. Detection of AlgG and AlgE in PAO1 supported the existence of internal promoters controlling expression of the respective genes. Overall experimental evidence was provided for the existence of a multiprotein complex required for alginate polymerization and secretion.
Assessing the Inactivation of Mycobacterium avium subsp.
paratuberculosis
during Composting of Livestock Carcasses
Authors: Tkachuk Victoria L. , Krause Denis O. , McAllister Tim A. , Buckley Katherine E. , Reuter Tim , Hendrick Steve , Ominski Kim H. 
Published: March 2013

ABSTRACT

Mycobacterium avium
subsp.
paratuberculosis
causes Johne's disease (JD) in ruminants, with substantial economic impacts on the cattle industry. Johne's disease is known for its long latency period, and difficulties in diagnosis are due to insensitivities of current detection methods. Eradication is challenging as
M. avium
subsp.
paratuberculosis
can survive for extended periods within the environment, resulting in new infections in naïve animals (W. Xu et al., J. Environ. Qual. 38:437-450, 2009). This study explored the use of a biosecure, static composting structure to inactivate
M. avium
subsp.
paratuberculosis. Mycobacterium smegmatis
was also assessed as a surrogate for
M. avium
subsp.
paratuberculosis
. Two structures were constructed to hold three cattle carcasses each. Naturally infected tissues and ground beef inoculated with laboratory-cultured
M. avium
subsp.
paratuberculosis
and
M. smegmatis
were placed in nylon and plastic bags to determine effects of temperature and compost environment on viability over 250 days. After removal, samples were cultured and growth of both organisms was assessed after 12 weeks. After 250 days,
M. avium
subsp.
paratuberculosis
was still detectable by PCR, while
M. smegmatis
was not detected after 67 days of composting. Furthermore,
M. avium
subsp.
paratuberculosis
remained viable in both implanted nylon and plastic bags over the composting period. As the compost never reached a homogenous thermophilic (55 to 65°C) state throughout each structure, an
in vitro
experiment was conducted to examine viability of
M. avium
subsp.
paratuberculosis
after exposure to 80°C for 90 days. Naturally infected lymph tissues were mixed with and without compost. After 90 days,
M. avium
subsp.
paratuberculosis
remained viable despite exposure to temperatures typically higher than that achieved in compost. In conclusion, it is unlikely composting can be used as a means of inactivating
M. avium
subsp.
paratuberculosis
associated with cattle mortalities.
Characterization of Undermethylated Sites in Vibrio cholerae
Authors: Dalia Ankur B. , Lazinski David W. , Camilli Andrew 
Published: March 2013

ABSTRACT

The activities of DNA methyltransferases are important for a variety of cellular functions in bacteria. In this study, we developed a modified high-throughput technique called
methyl
h
omopolymer
t
ail
m
ediated
seq
uencing (methyl HTM-seq) to identify the undermethylated sites in the
Vibrio cholerae
genome for the two DNA methyltransferases, Dam, an adenine methyltransferase, and VchM, a cytosine methyltransferase, during growth in rich medium
in vitro
. Many of the undermethylated sites occurred in intergenic regions, and for most of these sites, we identified the transcription factors responsible for undermethylation. This confirmed the presence of previously hypothesized DNA-protein interactions for these transcription factors and provided insight into the biological state of these cells during growth
in vitro
. DNA adenine methylation has previously been shown to mediate heritable epigenetic switches in gene regulation. However, none of the undermethylated Dam sites tested showed evidence of regulation by this mechanism. This study is the first to identify undermethylated adenines and cytosines genomewide in a bacterium using second-generation sequencing technology.
PelA Deacetylase Activity Is Required for Pel Polysaccharide Synthesis in Pseudomonas aeruginosa
Authors: Colvin Kelly M. , Alnabelseya Noor , Baker Perrin , Whitney John C. , Howell P. Lynne , Parsek Matthew R. 
Published: March 2013

ABSTRACTThe Pel polysaccharide serves as an intercellular adhesin for the formation and maintenance of biofilms in the opportunistic pathogenPseudomonas aeruginosa. Pel biosynthesis requires the products of a seven-gene operon,pelA-pelG, all of which are necessary for Pel-dependent biofilm formation and Pel-related phenotypes. One of the genes,pelA, encodes a protein with a predicted polysaccharide deacetylase domain. In this work, the role of the putative deacetylase domain in Pel production was examined. We first established that purified recombinant PelA hydrolyzed the pseudosubstratep-nitrophenyl acetatein vitro, and site-specific mutations of predicted deacetylase active-site residues reduced activity greater than 10-fold. Additionally, these mutants were deficient in Pel-dependent biofilm formation and wrinkly colony morphologyin vivo. Subcellular fractionation experiments demonstrate that PelA localizes to both the membrane and periplasmic fractions. Finally, antiserum against the Pel polysaccharide was generated, and PelA deacetylase mutants do not produce Pel-reactive material. Taken together, these results suggest that the deacetylase activity of PelA is important for the production of the Pel polysaccharide.
Cross-sectional study of sociodemographic patterning of risk factors for cardiovascular disease in three isolated-based subgroups of the Uyghur population in Xinjiang, China
Authors: Jiang Jingmei , Wufuer Mayila , Simayi Amuti , Nijiati Muyesai , Fan Ming , Zhu Pengcheng , Chen Fenghui , Shan Guangliang , Xue Fang , Tian Xiaobing , Li Feng , Hou Lei , Han Wei , Cheng Zuheng , Qiu Changchun 
Published: March 2013

ObjectiveTo explore the sociodemographic patterning of risk factors for cardiovascular disease (CVD) in three isolated-based subgroups of the Uyghur population in Xinjiang, China.DesignA cross-sectional study. Between 2005 and 2008, a non-probability sampling design method was used to select three specific groups of the Uyghur rural populations based on their potential socioeconomic status (ie, isolated, semi-isolated and open-environment status).SettingThree communities (named Desert, Turpan and Yuli Rob) in Southern Xinjiang autonomous region, China.Participants1656 people were included in this study. The inclusion criteria were that all participants were 18 years or older, they were descendants of at least three generations living in the same region, and there was no history of intermarriage.Main outcome measuresThe prevalence of CVD risk factors (ie, tobacco use, alcohol use, obesity, dyslipidemia, hypertension, diabetes, etc) was assessed.ResultsCompared with the Desert and Turpan communities, Yuli Rob had the highest levels of obesity, dyslipidemia and hypertension, and the Desert had the lowest levels of CVD risk factors. Age standardisation slightly altered the estimates, though the patterns remained unchanged. Some unique characteristics were also found. For example, the Desert group displayed significantly lower high-density lipoprotein cholesterol (HDLC) level compared with Yuli Rob and Turpan groups. The mean values were 0.63, 1.06 and 1.45 mmol/l for men and 0.64, 1.22 and 1.51 mmol/l for women (p<0.0001). The HDLC levels in the Desert group increased with increase in body mass index and fasting glucose levels, which was inconsistent with previous studies.ConclusionsIdentifying the unique CVD risk factors of the ethnic-specific populations is very important in development of tailored strategies for the prevention of CVD.