bluuebunny/crossref_metadata_2025_split huggingface dataset:
Macro‐ and micro‐anatomical, histological and computed tomography scan characterization of the nasopalatine canal
Authors: Liang Xin , Jacobs Reinhilde , Martens Wendy , Hu YuQian , Adriaensens Peter , Quirynen Marc , Lambrichts Ivo 
Published: June 2009

AbstractAim: To determine the human anatomic variability of the nasopalatine canal and determine its characteristics using an anatomical, histological and computed tomography (CT) scan evaluation.Materials and Methods: Measurements for the canal characteristics were carried out on 163 dry human skulls and 120 upper jaw spiral CT scans, taken from patients for pre‐operative planning purposes of implant placement in the incisor region. Furthermore, four human cadaver specimens were imaged using a high‐resolution magnetic resonance imaging (HR‐MRI) unit. Afterwards, these specimens were serially sectioned for histological examination to evaluate the nasopalatine canal region and its content.Results: The nasopalatine canal anatomy showed a large variability in morphology and dimensions, with the canal branching in up to four canals at the level of the nose. The canal diameter was on average 3.3 mm (±0.9 mm SD), and typically enlarged by age and male gender (p<0.05). HR‐MRI and histological sections enabled to identify the neurovascular structures within the canals.Conclusions: The large anatomic variations, the increased canal dimensions with age and the neurovascular canal content are all factors favouring a thorough three‐dimensional planning before surgery, such as implant placement, of the anterior maxillary region.
Risk factors for atherosclerosis in cases with severe periodontitis
Authors: Buhlin Kåre , Hultin Margareta , Norderyd Ola , Persson Lena , Pockley Alan Graham , Rabe Per , Klinge Björn , Gustafsson Anders 
Published: June 2009

AbstractAim: Studies have reported on an association between cardiovascular disease (CVD) and periodontitis. The purpose of this case–control study was to provide an insight into this association by determining the plasma levels of some risk markers for CVD in cases with periodontitis.Materials and Methods: Sixty‐eight cases with periodontitis, mean age 53.9 (SD 7.9) years, and 48 randomly selected healthy controls, mean age 53.1 (SD 7.9) years, were investigated. Fasting blood plasma was analysed for glucose, lipids, markers systemic inflammation, cytokines and antibodies against heat shock proteins (Hsp). The associations between periodontitis and the various substances analysed in plasma were calculated using a multivariate logistic regression model, which compensated for age, gender, smoking and body mass index.Results: The regression analyses revealed a significant association between periodontitis and high levels of C‐reactive protein (CRP) [odds ratio (OR) 4.0, confidence interval (CI) 1.4–11.4] and fibrinogen (OR 8.7, CI 2.6–28.4), IL‐18 (OR 6.5, CI 2.2–19.5), and decreased levels of IL‐4 (OR 0.12, CI 0.0–0.5). The study showed increased levels of antibodies against Hsp65 (OR 2.8, CI 1–7.6) and 70 (OR 2.9, CI 1.1–7.8) and decreased levels of antibodies against Hsp60 (OR 0.3, CI 0.1–0.8).Conclusions: Periodontitis was associated with increased levels of CRP, glucose, fibrinogen and IL‐18, and with decreased levels of IL‐4.
Relationship between Blood Pressure and Nocturia in Hypertensive Patients
Authors: SUGAYA Kimio , NAKADA Seiguo , SIMOJI Tsutomu , ODAGUCHI Naoyuki , NAKAMOTO Minori , NAKAZATO Satoshi 
Published: June 2009

Objective: We investigated the relationship between the pattern of hypertension and nocturia.Methods: Seventy‐seven patients who were being treated for hypertension completed a questionnaire regarding the number of times they urinated during the day and at night, and measured their blood pressure at home immediately after rising in the morning and just before going to sleep at night. The patients' blood pressure was also measured at the clinic. The patients were divided into groups according to their blood pressure patterns. The relationship between blood pressure pattern and number of urinations during the day and at night was investigated.Results: When the patients were divided into white coat hypertension, masked hypertension, sustained hypertension, and normotension groups, the number of daytime urinations was significantly lower in the sustained hypertension group compared with the normotension and white coat hypertension groups. When the subjects were divided into morning blood pressure surge and non‐morning surge groups or into morning hypertension and non‐morning hypertension groups, the numbers of nighttime urinations was significantly higher in the morning surge group or the morning hypertension group compared with the non‐morning surge group or non‐morning hypertension group, respectively.Conclusion: Sustained hypertension and elevation of blood pressure in the early morning influence the frequency of daytime and nighttime urination, respectively. It is important to control both the blood pressure and nocturia of hypertensive patients to improve their prognosis.
Adherence of
Escherichia coli
O157:H7 Mutants In Vitro and in Ligated Pig Intestines
Authors: Yin Xianhua , Chambers James R. , Wheatcroft Roger , Johnson Roger P. , Zhu Jing , Liu Bianfang , Gyles Carlton L. 
Published: June 2009

ABSTRACT

There are contradictory literature reports on the role of verotoxin (VT) in adherence of enterohemorrhagic
Escherichia coli
O157:H7 (O157 EHEC) to intestinal epithelium. There are reports that putative virulence genes of O island 7 (OI-7), OI-15, and OI-48 of this pathogen may also affect adherence in vitro. Therefore, mutants of
vt2
and segments of OI-7 and genes
aidA
15
(gene from OI-15) and
aidA
48
(gene from OI-48) were generated and evaluated for adherence in vitro to cultured human HEp-2 and porcine jejunal epithelial (IPEC-J2) cells and in vivo to enterocytes in pig ileal loops. VT2-negative mutants showed significant decreases in adherence to both HEp-2 and IPEC-J2 cells and to enterocytes in pig ileal loops; complementation only partially restored VT2 production but fully restored the adherence to the wild-type level on cultured cells. Deletion of OI-7 and
aidA
48
had no effect on adherence, whereas deletion of
aidA
15
resulted in a significant decrease in adherence in pig ileal loops but not to the cultured cells. This investigation supports the findings that VT2 plays a role in adherence, shows that results obtained in adherence of
E. coli
O157:H7 in vivo may differ from those obtained in vitro, and identified AIDA-15 as having a role in adherence of
E. coli
O157:H7.
Respective Roles of Culturable and Viable-but-Nonculturable Cells in the Heterogeneity of
Salmonella enterica
Serovar Typhimurium Invasiveness
Authors: Passerat Julien , Got Patrice , Dukan Sam , Monfort Patrick 
Published: June 2009

ABSTRACT

The existence of
Salmonella enterica
serovar Typhimurium viable-but-nonculturable (VBNC) cells is a public health concern since they could constitute unrecognized sources of infection if they retain their pathogenicity. To date, many studies have addressed the ability of
S
. Typhimurium VBNC cells to remain infectious, but their conclusions are conflicting. An assumption could explain these conflicting results. It has been proposed that infectivity could be retained only temporarily after entry into the VBNC state and that most VBNC cells generated under intense stress could exceed the stage where they are still infectious. Using a Radioselectan density gradient centrifugation technique makes it possible to increase the VBNC-cell/culturable-cell ratio without increasing the exposure to stress and, consequently, to work with a larger proportion of newly VBNC cells. Here, we observed that (i) in the stationary phase, the
S
. Typhimurium population comprised three distinct subpopulations at 10, 24, or 48 h of culture; (ii) the VBNC cells were detected at 24 and 48 h; (iii) measurement of invasion gene (
hilA
,
invF
, and
orgA
) expression demonstrated that cells are highly heterogeneous within a culturable population; and (iv) invasion assays of HeLa cells showed that culturable cells from the different subpopulations do not display the same invasiveness. The results also suggest that newly formed VBNC cells are either weakly able or not able to successfully initiate epithelial cell invasion. Finally, we propose that at entry into the stationary phase, invasiveness may be one way for populations of
S
. Typhimurium to escape stochastic alteration leading to cell death.
Gut Bacteria Are Not Required for the Insecticidal Activity of
Bacillus thuringiensis
toward the Tobacco Hornworm,
Manduca sexta
Authors: Johnston Paul R. , Crickmore Neil 
Published: June 2009

ABSTRACT

It was recently proposed that gut bacteria are required for the insecticidal activity of the
Bacillus thuringiensis
-based insecticide, DiPel, toward the lepidopterans
Manduca sexta
,
Pieris rapae
,
Vanessa cardui
, and
Lymantria dispar
. Using a similar methodology, it was found that gut bacteria were not required for the toxicity of DiPel or Cry1Ac or for the synergism of an otherwise sublethal concentration of Cry1Ac toward
M. sexta
. The toxicities of DiPel and of
B. thuringiensis
HD73 Cry
−
spore/Cry1Ac synergism were attenuated by continuously exposing larvae to antibiotics before bioassays. Attenuation could be eliminated by exposing larvae to antibiotics only during the first instar without altering larval sterility. Prior antibiotic exposure did not attenuate Cry1Ac toxicity. The presence of enterococci in larval guts slowed mortality resulting from DiPel exposure and halved Cry1Ac toxicity but had little effect on
B. thuringiensis
HD73 Cry
−
spore/Cry1Ac synergism.
B. thuringiensis
Cry
−
cells killed larvae after intrahemocoelic inoculation of
M. sexta
,
Galleria mellonella
, and
Spodoptera litura
and grew rapidly in plasma from
M. sexta
,
S. litura
, and
Tenebrio molitor
. These findings suggest that gut bacteria are not required for
B. thuringiensis
insecticidal activity toward
M. sexta
but that
B. thuringiensis
lethality is reduced in larvae that are continuously exposed to antibiotics before bioassay.
LasI/R and RhlI/R Quorum Sensing in a Strain ofPseudomonas aeruginosaBeneficial to Plants
Authors: Steindler Laura , Bertani Iris , De Sordi Luisa , Schwager Stephan , Eberl Leo , Venturi Vittorio 
Published: June 2009

ABSTRACTPseudomonas aeruginosapossesses three quorum-sensing (QS) systems which are key in the expression of a large number of genes, including many virulence factors. Most studies of QS inP. aeruginosahave been performed in clinical isolates and have therefore focused on its role in pathogenicity.P. aeruginosa, however, is regarded as a ubiquitous organism capable of colonizing many different environments and also of establishing beneficial associations with plants. In this study we examined the role of the twoN-acyl homoserine lactone systems known as RhlI/R and LasI/R in the environmental rice rhizosphere isolateP. aeruginosaPUPa3. Both the Rhl and Las systems are involved in the regulation of plant growth-promoting traits. The environmentalP. aeruginosaPUPa3 is pathogenic in two nonmammalian infection models, and only the doublelas rhlmutants are attenuated for virulence. In fact it was established that the two QS systems are not hierarchically organized and that they are both important for the colonization of the rice rhizosphere. This is an in-depth genetic and molecular study of QS in an environmentalP. aeruginosastrain and highlights several differences with QS regulation in the clinical isolate PAO1.
C-5(6) Sterol Desaturase from
Tetrahymena thermophila
: Gene Identification and Knockout, Sequence Analysis, and Comparison to Other C-5(6) Sterol Desaturases
Authors: Nusblat Alejandro D. , Najle Sebastián R. , Tomazic Mariela L. , Uttaro Antonio D. , Nudel Clara B. 
Published: June 2009

ABSTRACT

The gene coding for a C-5(6) sterol desaturase in
Tetrahymena thermophila
,
DES5A
, has been identified by the knockout of the TTHERM_01194720 sequence. Macronucleus transformation was achieved by biolistic bombardment and gene replacement through phenotypic assortment, using paromomycin as the selective agent. A knockout cell line (KO270) showed a phenotype consistent with that of the
DES5A
deletion mutant. KO270 converted only 6% of the added sterol into the C-5 unsaturated derivative, while the wild type accumulated 10-fold larger amounts under similar conditions. The decreased desaturation activity is specific for the C-5(6) position of lathosterol and cholestanol; other desaturations, namely C-7(8) and C-22(23), were not affected. Analysis by reverse transcription-PCR reveals that
DES5A
is transcribed both in the presence and absence of cholestanol in wild-type cells, whereas the transcribed gene was not detected in KO270. The growth of KO270 was undistinguishable from that of the wild-type strain. Des5Ap resembles known C-5(6) sterol desaturases, displaying the three typical histidine motifs, four hydrophobic transmembrane regions, and two other highly conserved domains of unknown function. A phylogenetic analysis placed
T. thermophila's
enzyme and
Paramecium
orthologues in a cluster together with functionally characterized C-5 sterol desaturases from vertebrates, fungi, and plants, although in a different branch.
Structural Analysis of the Core Region of O-Lipopolysaccharide of
Porphyromonas gingivalis
from Mutants Defective in O-Antigen Ligase and O-Antigen Polymerase
Authors: Paramonov Nikolay A. , Aduse-Opoku Joseph , Hashim Ahmed , Rangarajan Minnie , Curtis Michael A. 
Published: June 2009

ABSTRACT

Porphyromonas gingivalis
synthesizes two lipopolysaccharides (LPSs), O-LPS and A-LPS. Here, we elucidate the structure of the core oligosaccharide (OS) of O-LPS from two mutants of
P. gingivalis
W50, ΔPG1051 (WaaL, O-antigen ligase) and ΔPG1142 (O-antigen polymerase), which synthesize R-type LPS (core devoid of O antigen) and SR-type LPS (core plus one repeating unit of O antigen), respectively. Structural analyses were performed using one-dimensional and two-dimensional nuclear magnetic resonance spectroscopy in combination with composition and methylation analysis. The outer core OS of O-LPS occurs in two glycoforms: an “uncapped core,” which is devoid of O polysaccharide (O-PS), and a “capped core,” which contains the site of O-PS attachment. The inner core region lacks
l
(
d
)-
glycero
-
d
(
l
)-
manno
-heptosyl residues and is linked to the outer core via 3-deoxy-
d
-
manno
-octulosonic acid, which is attached to a glycerol residue in the outer core via a monophosphodiester bridge. The outer region of the “uncapped core” is attached to the glycerol and is composed of a linear α-(1→3)-linked
d
-Man OS containing four or five mannopyranosyl residues, one-half of which are modified by phosphoethanolamine at position 6. An amino sugar, α-
d
-allosamine, is attached to the glycerol at position 3. In the “capped core,” there is a three- to five-residue extension of α-(1→3)-linked Man residues glycosylating the outer core at the nonreducing terminal residue. β-
d
-GalNAc from the O-PS repeating unit is attached to the nonreducing terminal Man at position 3. The core OS of
P. gingivalis
O-LPS is therefore a highly unusual structure, and it is the basis for further investigation of the mechanism of assembly of the outer membrane of this important periodontal bacterium.
The Dual-Functioning Fumarate Reductase Is the Sole Succinate:Quinone Reductase in
Campylobacter jejuni
and Is Required for Full Host Colonization
Authors: Weingarten Rebecca A. , Taveirne Michael E. , Olson Jonathan W. 
Published: June 2009

ABSTRACT

Campylobacter jejuni
encodes all the enzymes necessary for a complete oxidative tricarboxylic acid (TCA) cycle. Because of its inability to utilize glucose,
C. jejuni
relies exclusively on amino acids as the source of reduced carbon, and they are incorporated into central carbon metabolism. The oxidation of succinate to fumarate is a key step in the oxidative TCA cycle.
C. jejuni
encodes enzymes annotated as a fumarate reductase (Cj0408 to Cj0410) and a succinate dehydrogenase (Cj0437 to Cj0439). Null alleles in the genes encoding each enzyme were constructed. Both enzymes contributed to the total fumarate reductase activity in vitro. The
frdA
::
cat
+
strain was completely deficient in succinate dehydrogenase activity in vitro and was unable to perform whole-cell succinate-dependent respiration. The
sdhA
::
cat
+
strain exhibited wild-type levels of succinate dehydrogenase activity both in vivo and in vitro. These data indicate that Frd is the only succinate dehydrogenase in
C. jejuni
and that the protein annotated as a succinate dehydrogenase has been misannotated. The
frdA
::
cat
+
strain was also unable to grow with the characteristic wild-type biphasic growth pattern and exhibited only the first growth phase, which is marked by the consumption of aspartate, serine, and associated organic acids. Substrates consumed in the second growth phase (glutamate, proline, and associated organic acids) were not catabolized by the the
frdA
::
cat
+
strain, indicating that the oxidation of succinate is a crucial step in metabolism of these substrates. Chicken colonization trials confirmed the in vivo importance of succinate oxidation, as the
frdA
::
cat
+
strain colonized chickens at significantly lower levels than the wild type, while the
sdhA
::
cat
+
strain colonized chickens at wild-type levels.
Role of Periplasmic Chaperones and BamA (YaeT/Omp85) in Folding and Secretion of Intimin from EnteropathogenicEscherichia coliStrains
Authors: Bodelón Gustavo , Marín Elvira , Fernández Luis Ángel 
Published: June 2009

ABSTRACTIntimin is a bacterial adhesin located on the surface of enteropathogenicEscherichia coliand other related bacteria that is believed to self-translocate across the outer membrane (OM), and therefore it has been regarded as a member of the type V secretion system (T5SS), which includes classical autotransporters (ATs). However, intimin has few structural similarities to classical ATs and an opposite topology with an OM-embedded N region and a secreted C region. Since the actual secretion mechanism of intimin is unknown, we investigated intimin biogenesis by analyzing its requirement of periplasmic chaperones (DsbA, SurA, Skp, and DegP) and of OM protein BamA (YaeT/Omp85) for folding, OM insertion, and translocation. Using full-length and truncated intimin polypeptides, we demonstrate that DsbA catalyzes the formation of a disulfide bond in the D3 lectin-like domain of intimin in the periplasm, indicating that this secreted C-terminal domain is at least partially folded prior to its translocation across the OM. We also show that SurA chaperone plays the major role for periplasmic transport and folding of the N region of intimin, whereas the parallel pathway made by Skp and DegP chaperones plays a secondary role in this process. Further, we demonstrate that BamA is essential for the insertion of the N region of intimin in the OM and that the protease activity of DegP participates in the degradation of misfolded intimin. The significance of these findings for a BamA-dependent secretion mechanism of intimin is discussed in the context of T5SSs.
Novel Cellular Organization in a Gliding Mycoplasma,
Mycoplasma insons
Authors: Relich Ryan F. , Friedberg Aaron J. , Balish Mitchell F. 
Published: June 2009

ABSTRACT

Mycoplasmas that are known to exhibit gliding motility possess a differentiated tip structure. This polar organelle mediates cytadherence and gliding motor activity and contains a cytoskeleton-like component that provides structural support. Here, we describe gliding motility and a unique cytoskeleton in
Mycoplasma insons
, which lacks any obviously differentiated tip structure.
A pragmatic randomised trial of stretching before and after physical activity to prevent injury and soreness
Authors: Jamtvedt Gro , Herbert Robert D , Flottorp Signe , Odgaard-Jensen Jan , Håvelsrud Kari , Barratt Alex , Mathieu Erin , Burls Amanda , Oxman Andrew D 
Published: June 2009

ObjectiveTo determine the effects of stretching before and after physical activity on risks of injury and soreness in a community population.DesignInternet-based pragmatic randomised trial conducted between January 2008 and January 2009.SettingInternational.ParticipantsA total of 2377 adults who regularly participated in physical activity.InterventionsParticipants in the stretch group were asked to perform 30 s static stretches of seven lower limb and trunk muscle groups before and after physical activity for 12 weeks. Participants in the control group were asked not to stretch.Main outcome measurementsParticipants provided weekly on-line reports of outcomes over 12 weeks. Primary outcomes were any injury to the lower limb or back, and bothersome soreness of the legs, buttocks or back. Injury to muscles, ligaments and tendons was a secondary outcome.ResultsStretching did not produce clinically important or statistically significant reductions in all-injury risk (HR=0.97, 95% CI 0.84 to 1.13), but did reduce the risk of experiencing bothersome soreness (mean risk of bothersome soreness in a week was 24.6% in the stretch group and 32.3% in the control group; OR=0.69, 95% CI 0.59 to 0.82). Stretching reduced the risk of injuries to muscles, ligaments and tendons (incidence rate of 0.66 injuries per person-year in the stretch group and 0.88 injuries per person-year in the control group; HR=0.75, 95% CI 0.59 to 0.96).ConclusionStretching before and after physical activity does not appreciably reduce all-injury risk but probably reduces the risk of some injuries, and does reduce the risk of bothersome soreness.Trial registrationanzctr.org.au12608000044325.
Implementation of electronic locking devices for adolescents at German tobacco vending machines: intended and unintended changes of supply and demand
Authors: Schneider S , Meyer C , Yamamoto S , Solle D 
Published: June 2009

Background:Starting from 1 January 2007, electronic locking devices based on proof-of-age (via electronic cash cards or a European driving licence) were installed in approximately 500 000 vending machines across Germany to restrict the purchase of cigarettes to those over the age of 16.Objective:To examine changes in the number of tobacco vending machines before and after the introduction of these new measures.Design:The total number of commercial tobacco sources in 2 selected districts (70 000 inhabitants) in Cologne were recorded and mapped. This major German city was the ideal setting for this study as investigators were able to use existing sociogeographical data from the area. A complete inventory was compiled in autumn 2005 and 2007. A total of 780 students aged 12 to 15 were also interviewed in the study areas. The main outcome measures were quantities and locations of commercial tobacco sources.Results:Between 2005 and 2007 the total number of tobacco sources decreased from 315 to 277 within the study area. Although the most obvious reduction was detected in the number of outdoor vending machines (−48%), the number of indoor vending machines also decreased by 8%. Adolescents changed from vending machines to other sources for cigarettes, particularly kiosks or friends (+31% points usage rate, p<0.001; +35% points usage rate, p<0.001, respectively).Conclusions:Although the number of tobacco vending machines decreased, this has not had a significant impact on cigarette acquisition by underage smokers as they were able to circumvent this new security measure in several different ways.