bluuebunny/crossref_metadata_2025_split huggingface dataset:
Responses of Cattle to Gastrointestinal Colonization by
Escherichia coli
O157:H7
Authors: Nart Pablo , Naylor Stuart W. , Huntley John F. , McKendrick Iain J. , Gally David L. , Low J. Christopher 
Published: September 2008

ABSTRACT

Recent research has established that the terminal rectum is the predominant colonization site of enterohemorrhagic
Escherichia coli
O157:H7 in cattle. The main aim of the present work was to investigate pathological changes and associated immune responses at this site in animals colonized with
E. coli
O157:H7. Tissue and gastrointestinal samples from a total of 22 weaned Holstein-cross calves challenged with
E. coli
O157:H7 were analyzed for bacterial colonization and pathology. Five unexposed age-matched calves were used as comparative negative controls.
E. coli
O157:H7 bacteria induced histopathological alterations of the rectal mucosa with enterocyte remodeling. This was often associated with removal of the colonized epithelial layer. Immunogold labeling and transmission electron microscopy (TEM) showed
E. coli
O157 bacteria on pedestals, as part of attaching and effacing lesions. These pathological changes induced a local infiltration of neutrophils that was quantified as larger in infected animals. Rectal mucosal immunoglobulin A responses were detected against the
E. coli
O157:H7 antigen. This work presents evidence that
E. coli
O157:H7 is not a commensal bacteria in the bovine host and that the mucosal damage produced by
E. coli
O157:H7 colonization of the terminal rectum induces a quantifiable innate immune response and production of specific mucosal antibodies.
Analysis of the Isoprenoid Biosynthesis Pathways in
Listeria monocytogenes
Reveals a Role for the Alternative 2-C-Methyl-
d
-Erythritol 4-Phosphate Pathway in Murine Infection
Authors: Begley Máire , Bron Peter A. , Heuston Sinead , Casey Pat G. , Englert Nadine , Wiesner Jochen , Jomaa Hassan , Gahan Cormac G. M. , Hill Colin 
Published: September 2008

ABSTRACT

Most bacteria synthesize isoprenoids through one of two essential pathways which provide the basic building block, isopentyl diphosphate (IPP): either the classical mevalonate pathway or the alternative non-mevalonate 2-C-methyl-
d
-erythritol 4-phosphate (MEP) pathway. However, postgenomic analyses of the
Listeria monocytogenes
genome revealed that this pathogen possesses the genetic capacity to produce the complete set of enzymes involved in both pathways. The nonpathogenic species
Listeria innocua
naturally lacks the last two genes (
gcpE
and
lytB
) of the MEP pathway, and bioinformatic analyses strongly suggest that the genes have been lost through evolution. In the present study we show that heterologous expression of
gcpE
and
lytB
in
L. innocua
can functionally restore the MEP pathway in this organism and confer on it the ability to induce Vγ9Vδ2 T cells. We have previously confirmed that both pathways are functional in
L. monocytogenes
and can provide sufficient IPP for normal growth in laboratory media (M. Begley, C. G. Gahan, A. K. Kollas, M. Hintz, C. Hill, H. Jomaa, and M. Eberl, FEBS Lett. 561:99-104, 2004). Here we describe a targeted mutagenesis strategy to create a double pathway mutant in
L. monocytogenes
which cannot grow in the absence of exogenously provided mevalonate, confirming the requirement for at least one intact pathway for growth. In addition, murine studies revealed that mutants lacking the MEP pathway were impaired in virulence relative to the parent strain during intraperitoneal infection, while mutants lacking the classical mevalonate pathway were not impaired in virulence potential. In vivo bioluminescence imaging also confirmed in vivo expression of the
gcpE
gene (MEP pathway) during murine infection.
Enhanced Microscopic Definition of
Campylobacter jejuni
81-176 Adherence to, Invasion of, Translocation across, and Exocytosis from Polarized Human Intestinal Caco-2 Cells
Authors: Hu Lan , Tall Ben D. , Curtis Sherill K. , Kopecko Dennis J. 
Published: September 2008

ABSTRACT

Campylobacter jejuni
-mediated pathogenesis involves gut adherence and translocation across intestinal cells. The current study was undertaken to examine the
C. jejuni
interaction with and translocation across differentiated Caco-2 cells to better understand
Campylobacter
's pathogenesis. The efficiency of
C. jejuni
81-176 invasion of Caco-2 cells was two- to threefold less than the efficiency of invasion of INT407 cells. Adherence-invasion analyses indicated that
C. jejuni
81-176 adhered to most INT407 cells but invaded only about two-thirds of the host cells over 2 h (two bacteria/cell). In contrast, only 11 to 17% of differentiated Caco-2 cells were observed to bind and internalize either
C. jejuni
strain 81-176 or NCTC 11168, and a small percentage of infected Caco-2 cells contained 5 to 20 internalized bacteria per cell after 2 h. Electron microscopy revealed that individual
C. jejuni
cells adhered to the tips of host cell microvilli via intimate flagellar contacts and by lateral bacterial binding to the sides of microvilli. Next, bacteria were observed to bind at the apical host membrane surface via presumed interactions at one pole of the bacterium and with host membrane protrusions located near intercellular junctions. The latter contacts apparently resulted in coordinated, localized plasma membrane invagination, causing simultaneous internalization of bacteria into an endosome. Passage of this
Campylobacter
endosome intracellularly from the apical surface to the basolateral surface occurred over time, and bacterial release apparently resulted from endosome-basolateral membrane fusion (i.e., exocytosis). Bacteria were found intercellularly below tight junctions at 60 min postinfection, but not at earlier times. This study revealed unique host cell adherence contacts, early endocytosis-specific structures, and a presumptive exocytosis component of the transcellular transcytosis route.
Intestinal Adherence of
Vibrio cholerae
Involves a Coordinated Interaction between Colonization Factor GbpA and Mucin
Authors: Bhowmick Rudra , Ghosal Abhisek , Das Bhabatosh , Koley Hemanta , Saha Dhira Rani , Ganguly Sandipan , Nandy Ranjan K. , Bhadra Rupak K. , Chatterjee Nabendu Sekhar 
Published: September 2008

ABSTRACT

The chitin-binding protein GbpA of
Vibrio cholerae
has been recently described as a common adherence factor for chitin and intestinal surface. Using an isogenic in-frame
gbpA
deletion mutant, we first show that
V. cholerae
O1 El Tor interacts with mouse intestinal mucus quickly, using GbpA in a specific manner. The
gbpA
mutant strain showed a significant decrease in intestinal adherence, leading to less colonization and fluid accumulation in a mouse in vivo model. Purified recombinant GbpA (rGbpA) specifically bound to
N
-acetyl-
d
-glucosamine residues of intestinal mucin in a dose-dependent, saturable manner with a dissociation constant of 11.2 μM. Histopathology results from infected mouse intestine indicated that GbpA binding resulted in a time-dependent increase in mucus secretion. We found that rGbpA increased the production of intestinal secretory mucins (MUC2, MUC3, and MUC5AC) in HT-29 cells through upregulation of corresponding genes. The upregulation of
MUC2
and
MUC5AC
genes was dependent on NF-κB nuclear translocation. Interestingly, mucin could also increase GbpA expression in
V. cholerae
in a dose-dependent manner. Thus, we propose that there is a coordinated interaction between GbpA and mucin to upregulate each other in a cooperative manner, leading to increased levels of expression of both of these interactive factors and ultimately allowing successful intestinal colonization and pathogenesis by
V. cholerae
.
Comparison between confocal scanning laser tomography, scanning laser polarimetry and optical coherence tomography on the ability to detect localised retinal nerve fibre layer defects in glaucoma patients
Authors: Windisch B K , Harasymowycz P J , See J L , Chauhan B C , Belliveau A C , Hutchison D M , Nicolela M T 
Published: September 2008

Background/aim:To compare the ability of confocal scanning laser tomography (CSLT), scanning laser polarimetry (SLP) and optical coherence tomography (OCT) in recognising localised retinal nerve fibre layer (RNFL) defects.Methods:51 eyes from 43 patients with glaucoma were identified by two observers as having RNFL defects visible on optic disc photographs. 51 eyes of 32 normal subjects were used as controls. Three masked observers evaluated CSLT, SLP and OCT images to determine subjectively the presence of localised RNFL defects.Results:Interobserver agreement was highest with OCT, followed by SLP and CSLT (mean kappa: 0.83, 0.69 and 0.64, respectively). RNFL defects were identified in 58.8% of CSLT, 66.7% of SLP and 54.9% of OCT (p = 0.02 between SLP and OCT) by at least two observers. In the controls, 94.1% of CSLT, 84.3% of SLP and 94.1% of OCT scans, respectively, were rated as normal (p = 0.02 between CSLT and SLP, and SLP and OCT).Conclusion:Approximately 20–40% of localised RNFL defects identified by colour optic disc photographs are not detected by CSLT, SPL or OCT. SLP showed a higher number of false-positive results than the other techniques, but also had a higher proportion of correctly identified RNFL defects in the glaucoma population.
Epigenetic dysregulation of the Wnt signalling pathway in chronic lymphocytic leukaemia
Authors: Chim C S , Pang R , Liang R 
Published: September 2008

Background:Wnt signalling has recently been implicated in the pathogenesis of cancer.Methods:This study investigated the activity of Wnt signalling in peripheral blood chronic lymphocytic leukaemia (CLL) lymphocytes, and the methylation status of seven soluble Wnt antagonist genes, includingWIF1, DKK3, APC, SFRP1, SFRP2, SFRP4andSFRP5, by using methylation-specific PCR in the peripheral blood CLL lymphocytes and bone marrow samples of patients with CLL at diagnosis.Results:In the peripheral blood CLL lymphocytes, constitutive activation of Wnt signalling was detected, associated with hypermethylation of the soluble Wnt inhibitor genes. In the diagnostic CLL marrow samples, methylation of the seven genes was detected in up to 36.4% of samples. Moreover, 23 (52.3%) patients had methylation of at least one of the seven genes, of whom 14 (60.8%) had methylation of two or more Wnt inhibitor genes. Apart from an association of advanced age withDKK3methylation, there was no association of gene hypermethylation with either clinical characteristics (including age, gender, lymphocyte count at diagnosis, Rai stage and poor-risk karyotype) or survival.Conclusion:Wnt signalling is constitutively activated in CLL B lymphocytes in association with methylation of multiple soluble Wnt antagonist genes. Methylation of these soluble Wnt antagonist genes, occasionally multiple genes, in primary CLL marrow samples suggests an important role in CLL pathogenesis. Moreover, this study underscored the importance of studying methylation of a panel of, but not individual, genes regulating a cellular pathway.
Ignoring puff counts: another shortcoming of the Federal Trade Commission cigarette testing programme
Authors: Kozlowski L T , Whetzel C A , Stellman S D , O’Connor R J 
Published: September 2008

Objectives:To examine reasons behind the failure of the Federal Trade Commission (FTC) to preserve puff count information from standard cigarette testing and to elucidate the importance of puff count to overall tar yields.Methods:We reviewed industry documents on origins of the FTC test and datasets provided by the Tobacco Institute Testing Laboratory to the tobacco industry and FTC for reporting purposes.Results:The majority of the tobacco industry argued for “dual reporting” of tar yields—both per cigarette and per puff. Despite a request from the Tobacco Institute in 1967 that puff count information be preserved, documents and recent communications with the FTC indicate that puff number data have not been maintained by the government. In contrast, for the cigarette industry, puff count data are a fundamental and routine part of testing and important to cigarette design. A sample of puff counts for cigarettes tested in 1996 (n = 471) shows that on average 100 mm cigarettes have 18% more puffs taken on them than do 85 mm cigarettes in standard tests (7.66 vs 9.03; p<0.01). The 10th percentile puff count is 6.8 and the 90th percentile is 8.8 for king size; the 10th percentile puff count is 8.2 and the 90th percentile is 10.0 for 100 mm cigarettes, indicating that puff counts can vary substantially among brands.Conclusions:The FTC has failed to seek or preserve puff count information that the industry finds important. Any standard test of tar and nicotine yields should at minimum preserve puff count information.
The feasibility of measuring puffing behaviour in roll-your-own cigarette smokers
Authors: Shahab L , West R , McNeill A 
Published: September 2008

Background/objective:Despite the increase in roll-your-own (RYO) cigarette consumption in many countries, very little is known about RYO smokers. In order to estimate the health risks inherent in RYO use, it is important to assess exposure to tobacco toxins in this group. Exposure is determined by a number of factors, including puffing behaviour, but so far this issue has not been addressed among RYO smokers. This study sought both to determine the feasibility of measuring puffing behaviour in this group, its reliability and validity, and to characterise puffing behaviour among RYO smokers compared with smokers of factory-made (FM) cigarettes.Methods:At two visits, 24 hours apart, 131 FM and 29 RYO cigarette smokers provided saliva samples that were assayed for cotinine, a measure of nicotine intake and thus smoke exposure. Self-reported puffing behaviour of participants, as well as their demographic and smoking characteristics were also assessed. At the end of the first visit, smokers were shown how to use a portable smoking topography machine that measures puffing behaviour, the CReSSmicro, and asked to smoke all cigarettes with this machine until the second visit, when participants were asked to provide feedback on using the device.Results:Both RYO and FM cigarette smokers reported that the CReSSmicro was easy to use; however, RYO cigarette smokers were more likely to have missing data, to reduce cigarette consumption and to indicate a change in their puffing behaviour because of the device. Machine-determined puffing behaviour was equally stable over time in both groups with similar ability to predict exposure; cotinine levels were related to machine but not to self-reported puffing parameters. Overall, RYO smokers appeared to puff cigarettes less hard but for longer than FM cigarette smokers.Conclusion:The measurement of puffing behaviour using a topography device is feasible but less practicable for RYO than FM cigarette smokers. Puffing parameters show comparable reliability and validity for both groups of smokers and reveal some differences in smoking topography dependent on the type of cigarette smoked.
PREP advertisement features affect smokers’ beliefs regarding potential harm
Authors: Strasser A A , Tang K Z , Tuller M D , Cappella J N 
Published: September 2008

Background:The Institute of Medicine report on potential reduced exposure products (PREPs) recommends that advertising and labelling be regulated to prevent explicitly or implicitly false or misleading claims. Belief that a product is less harmful may increase use or prevent smoking cessation.Objective:To determine the effect of altering advertisement features on smokers’ beliefs of the harm exposure from a PREP.Methods:A Quest advertisement was digitally altered using computer software and presented to participants using web-based television recruitment contracted through a survey company. 500 current smokers completed demographic and smoking history questions, were randomised to view one of three advertisement conditions, then completed eight items assessing their beliefs of the harmfulness of the product. Advertisement conditions included the original, unaltered advertisement; a “red” condition where the cigarette packages were digitally altered to the colour red, implying increased harm potential; and a “no text” condition where all text was removed to reduce explicit product information. Polytomous logistic regression, using “incorrect,” “unsure” and “correct” as outcomes, and advertisement type and covariates as predictors, was used for analyses.Results:Participants randomised to the “no text” advertisement were less likely to be incorrect in their beliefs that Quest cigarettes are lower in tar, less addictive, less likely to cause cancer, have fewer chemicals, are healthier and make smoking safer.Conclusions:Smokers can form false beliefs about the harmfulness of PREP products based on how the PREPs are marketed. Careful examination must be undertaken to provide empirical evidence to better formulate regulatory principles of PREP advertising.
Existing technologies to reduce specific toxicant emissions in cigarette smoke
Authors: O’Connor R J , Hurley P J 
Published: September 2008

Background:The World Health Organization Tobacco Product Regulation (TobReg) study group has proposed emissions level performance standards for nine toxicants (NNN, NNK, acetaldehyde, acrolein, 1,3-butadiene, CO, BaP, benzene and formaldehyde, all expressed as micrograms per milligram nicotine as measured under the Canadian intensive method) in cigarette smoke for parties to the FCTC in conjunction with regular monitoring of emissions of nine other toxicants of interest, nicotine and nicotine-free dry particulate matter (NFDPM, or “tar”).Methods:We examined the published literature and publicly available tobacco industry documents to determine the extent to which existing available technologies can be applied to reduce the emissions of the specified toxicants in cigarette smoke.Results:Agricultural practices (for example, fertilisers, curing), plant characteristics (for example, protein content, nicotine content), tobacco blending (for example, American blend vs Virginia blend) and cigarette design (for example, additives, filters, paper) issues all have roles in the generation and reduction of specific smoke toxicants. The tobacco industry has explored a number of technologies, including selective filtration, changes to curing practices and rod additives to reduce specific toxicants.Conclusions:Technologies exist to reduce the toxicants identified by TobReg. The extent to which the industry is able to simultaneously reduce toxicants, however, is unknown.
BESSIS–MOUSSA–VILLANI CONJECTURE AND GENERALIZED GAUSSIAN RANDOM VARIABLES
Authors: BOŻEJKO MAREK 
Published: September 2008

In this paper we give the solution of Bessis–Moussa–Villani (BMV) conjecture for the generalized Gaussian random variables [Formula: see text] where f is in the real Hilbert space [Formula: see text].The main examples of generalized Gaussian random variables are q-Gaussian random variables, (-1 ≤ q ≤ 1), related to q-CCR relation and other commutation relations. We will prove that BMV conjecture is true for all operators A = G(f), B = G(g); i.e. we will show that the function [Formula: see text] is positive-definite function on the real line. The case q = 0, i.e. when G(f) are the free Gaussian (Wigner) random variables and the operators A and B are free with respect to the vacuum trace was proved by Fannes and Petz.23
A Pilot Study of Compositional Analysis of the Breast and Estimation of Breast Mammographic Density Using Three-Dimensional T1-Weighted Magnetic Resonance Imaging
Authors: Khazen Michael , Warren Ruth M.L. , Boggis Caroline R.M. , Bryant Emilie C. , Reed Sadie , Warsi Iqbal , Pointon Linda J. , Kwan-Lim Gek E. , Thompson Deborah , Eeles Ros , Easton Doug , Evans D. Gareth , Leach Martin O. ,   for the Collaborators in the United Kingdom Medical Research Council Magnetic Resonance Imaging in Breast Screening (MARIBS) Study
Published: September 2008

AbstractPurpose: A method and computer tool to estimate percentage magnetic resonance (MR) imaging (MRI) breast density using three-dimensional T1-weighted MRI is introduced, and compared with mammographic percentage density [X-ray mammography (XRM)].Materials and Methods: Ethical approval and informed consent were obtained. A method to assess MRI breast density as percentage volume occupied by water-containing tissue on three-dimensional T1-weighted MR images is described and applied in a pilot study to 138 subjects who were imaged by both MRI and XRM during the Magnetic Resonance Imaging in Breast Screening study. For comparison, percentage mammographic density was measured from matching XRMs as a ratio of dense to total projection areas scored visually using a 21-point score and measured by applying a two-dimensional interactive program (CUMULUS). The MRI and XRM percent methods were compared, including assessment of left-right and interreader consistency.Results: Percent MRI density correlated strongly (r = 0.78; P &lt; 0.0001) with percent mammographic density estimated using Cumulus. Comparison with visual assessment also showed a strong correlation. The mammographic methods overestimate density compared with MRI volumetric assessment by a factor approaching 2.Discussion: MRI provides direct three-dimensional measurement of the proportion of water-based tissue in the breast. It correlates well with visual and computerized percent mammographic density measurements. This method may have direct application in women having breast cancer screening by breast MRI and may aid in determination of risk.(Cancer Epidemiol Biomarkers Prev 2008;17(9):2268–74)
Sun Exposure and the Incidence of Melanocytic Nevi in Young Australian Children
Authors: Harrison Simone Lee , MacLennan Robert , Buettner Petra Gertraud 
Published: September 2008

Abstract
The number of melanocytic nevi (MN) is an important risk factor for cutaneous melanoma. The present study further investigated the relationship between sun exposure, the incidence of MN, and the prevalence of large acquired MN (≥5 mm). A cohort of 479 preschool children born in Townsville, Australia was examined for MN in 1991 and a year later. Sun exposure was assessed by questionnaire. The erythemally effective dose of solar UV radiation was estimated from questionnaire data combined with local UV biometry. Almost all (97.7%) children had acquired new MN (median, 12), with a median incidence rate of 11.0 per year (interquartile range, 7.0-16.5). Total number of hours of sun exposure during follow-up (P = 0.034) and tendency to burn (P = 0.028) were independent risk factors for MN incidence. Sunburn experience during follow-up failed to reach significance when adjusted for tendency to burn. Lifetime number of sunburns (P &lt; 0.001) and the severity of sunburns experienced during follow-up (P &lt; 0.001) were significantly related to the presence of large acquired MN at follow-up. Reducing the total number of hours of sun exposure is particularly relevant in sun-sensitive children and may restrain the development of MN, whereas avoiding sunburn in young children might prevent large MN, subsequently reducing the risk of melanoma. (Cancer Epidemiol Biomarkers Prev 2008;17(9):2318–24)