bluuebunny/crossref_metadata_2025 huggingface dataset:
In vitro effect of free bile acids on the bile canaliular membrane phospholipids in the rat
Authors: Yousef I. M. , Fisher M. M.
Published: December 2009

Liver cell plasma membranes of male rats were isolated and separated into two fractions, one rich in bile canalicular membranes (BCM) and the other comprising the rest of the plasma membranes (PM). Aliquots of BCM, PM, and microsomes were incubated with deoxycholic, chenodeoxycholic, or cholic acid at bile acid – membrane phospholipid mole ratios up to 100, and the phospholipids solubilized from the membranes were analyzed.Phospholipid solubilization from the PM and from microsomes was linear and apparently nonselective, while that from the BCM was biphasic and distinctly selective. Phosphatidyl choline and phosphatidyl ethanolamine made up 90% of the phospholipids solubilized from the BCM at a bile acid – membrane phospholipid mole ratio sufficient to solubilize about 50% of the total phospholipids of the BCM. Of particular interest was the observation that the molecular species and fatty acid composition of the phospholipids solubilized from the BCM under these experimental conditions were similar to those of bile obtained from the same animal, and were quite unlike those solubilized at higher bile acid – phospholipid mole ratios. The data are discussed in terms of the mechanism of the biliary secretion of phospholipids.
Early growth of lodgepole pine after establishment of alsike clover–Rhizobium nitrogen-fixing symbiosis
Authors: Trowbridge R. , Holl F.B.
Published: December 2009

An overdense lodgepole pine (Pinuscontorta Dougl. ex Loud.) stand was knocked down and the site was prepared by broadcast burn, windrow burn, or mechanical forest floor removal. Inoculated alsike clover (Trifoliumhybridum L.) was seeded at 0, 10, 20, and 30 kg/ha for the three different site preparation treatments to determine the effects of (i) site preparation on infection and effectiveness of the clover–Rhizobium symbiosis and clover percent cover and (ii) the clover–Rhizobium N2-fixing symbiosis on survival, early growth, and foliar nitrogen concentration of lodgepole pine seedlings. The N2-fixing symbiosis established well in all treatments. Clover percent cover increased with increasing rate of seeding, although by relatively few percent in the clover seeded plots. Broadcast burning, windrow burning, and mechanical forest floor removal did not affect the establishment of the N2-fixing symbiosis or clover percent cover. Lodgepole pine survival was not affected by the seeding treatments in any year, nor were height measurements during the first three growing seasons. Seedling height was slightly less in clover-seeded plots compared with controls in the fourth growing season. Lodgepole pine seedlings on clover-seeded plots had decreased diameter growth compared with controls during the first three growing seasons, but incremental diameter growth no longer showed this effect by the fourth growing season. Needle mass (g/100 needles) was less in clover-seeded plots at the end of the second growing season, but this effect was reversed by the fourth growing season, when both needle mass and foliar nitrogen concentration in lodgepole pine foliage were greater in clover-seeded plots.
Element distribution in red spruce (Picearubens) fine roots; evidence for aluminium toxicity at Whiteface Mountain
Authors: Schlegel Hedda , Amundson Robert G. , Hüttermann Aloys
Published: December 2009

To determine the element distribution in fine roots of red spruce (Picearubens Sarg.) at a high-elevation decline site on Whiteface Mountain, New York, fine-root samples were collected and analysed by X-ray microanalysis. Aluminium was found in very high concentrations in the root cortex, but could not be detected in stelar tissues. In contrast, magnesium was found only in the central cylinder in low amounts. The calcium concentration in the cortex was low, but was higher in the stele. Aluminium has been shown to interfere with cation uptake by blocking exchange sites in the cortical apoplast. Thus these results strongly suggest that the low foliar magnesium and calcium contents of the declining red spruce trees are driven by aluminium-induced inhibition of magnesium and calcium uptake. Soil solution chemistry, ion distribution in fine roots, and foliar ion contents at Whiteface Mountain were compared with equivalent data from other forest sites as well as with data from controlled studies on spruce seedlings. These data suggest that aluminium toxicity contributes to red spruce decline at Whiteface Mountain.
Glyphosate efficacy on eastern Canadian forest weeds. Part I: experimental design and on-target deposit
Authors: Thompson D. G. , Pitt D. G. , Fleming R. A. , Kettela E. G.
Published: December 2009

Experimental methods and resulting on-target deposit data are presented for an operational field trial designed to evaluate glyphosate (Vision®) efficacy using two different dispersal systems (AU5000 Micronairs® and conventional hydraulic nozzles). A range of glyphosate rates (0, 0.25, 0.50, 0.75, and 1.00 kg acid equivalent per hectare) was aerially applied in a randomized complete block design to four cutover sites in New Brunswick. Formulation, tank-mix, droplet, and chemical analyses were conducted to quantify actual on-target deposit for each treatment. Data for the calibrated portion of each swath suggested that the Micronair system produced a slightly narrower drop-diameter spectrum (0–677 μm, volume median diameter = 300 μm) than the hydraulic system (0–1085 μm, volume median diameter = 425 μm). Analysis of variance and orthogonal contrasts indicated that on-target deposit for the Micronair system (average accountability = 71%) was not significantly different from that of the hydraulic system (average accountability = 82%) for three of four rates tested. Unrepresentative meteorological and site conditions affecting Micronair treatments in two blocks resulted in reduced deposit for the treatment of 1.00 kg acid equivalent per hectare. Substantial variability within treatments was observed for both dispersal systems (41 and 47% coefficient of variation for Micronair and hydraulic systems, respectively). Overall, results suggest no significant differences between the two dispersal systems (as calibrated) in terms of on-target deposit efficiency or variability. Both on-target droplet density and chemical deposit data reflected differences associated with blocks. This fact highlights the need for further studies on meteorological and operational factors on deposit.
Nitrogen fixation in Sitka alder by 15N isotope dilution after eight growing seasons in a lodgepole pine site
Authors: Mead Donald J. , Preston Caroline M.
Published: December 2009

Owing to high costs and limitations of the method, there have been no field studies using 15N isotope dilution to measure the amount of N fixed by alder in the field. As part of a long-term (8-year) study of the fate of 15N-labelled fertilizer applied to lodgepole pine (Pinuscontorta Dougl. var. latifolia Engelm.) in the field in interior British Columbia, we observed much lower 15N enrichment in Sitka alder (Alnussinuata (Reg.) Rydb.) than in lodgepole pine or other understory species. Calculations using lodgepole pine, herbs, and shrubs as nonfixing reference crops all indicated that the percent of N derived from the atmosphere in Sitka alder at this site was very high, 94–99%. The long period for stabilization of residual 15N-labelled fertilizer in organic form in the soil and for establishment of plant root systems alleviated many of the problems associated with the 15N isotope dilution method. By contrast, calculations of the percent of N derived from the atmosphere at the end of the first growing season gave erratic and unreliable results.
Analysis of real-time serotonin (5-HT) availability during experimental colitis in mouse
Authors: Bertrand Paul P. , Barajas-Espinosa Alma , Neshat Shadia , Bertrand Rebecca L. , Lomax Alan E.
Published: December 2009

Serotonin (5-HT)-containing enterochromaffin (EC) cells of the intestine transduce chemical and mechanical stimuli from the intestinal lumen by releasing 5-HT on to afferent nerve terminals. Dysfunctional mucosal 5-HT signaling has been implicated in heightened visceral sensitivity and altered motility in patients with inflammatory bowel disease and in animal models. Our aim was to characterize the release and uptake of 5-HT in the mouse dextran sulfate sodium (DSS; 5% wt/vol) model of colitis. We made electrochemical recordings and used an ELISA assay to determine mucosal 5-HT release and uptake in untreated mice and mice with DSS-induced colitis. Peak and steady-state 5-HT concentrations were measured before and during blockade of the serotonin reuptake transporter (SERT) with 1 μM fluoxetine. Electrochemical recordings showed that colons from DSS-treated mice had roughly twice the steady-state levels of extracellular 5-HT and compression-evoked 5-HT release compared with untreated mice. Fluoxetine doubled the compression-evoked and steady-state 5-HT levels in control and DSS mice. These data were supported by ELISA assays, which showed enhanced 5-HT release during colitis, by immunohistochemical analyses, which showed increases in EC cell numbers, and by real-time PCR, which identified a decrease in SERT mRNA expression in the mucosa during colitis. These data are the first to demonstrate 5-HT release close to its release site and near its site of action during DSS-colitis. We conclude that DSS-colitis increases 5-HT availability primarily by an increase in the numbers of EC cells and/or of content of 5-HT in these EC cells.
Progesterone receptor A mediates VIP inhibition of contraction
Authors: Cheng Ling , Biancani Piero , Behar Jose
Published: December 2009

The slow transit time of the colon in females with constipation is due to impairment of agonist-induced contraction. The impairment is associated with downregulation of G proteins that mediate contraction and upregulation of Gs proteins that mediate relaxation. These changes are caused by overexpression of progesterone (P4) receptors in the colon, rendering its muscle cells sensitive to physiological P4 concentrations. Downregulation of Gq/11 is mediated by P4 receptor B (PR-B). We examined whether upregulation of Gs proteins increased the inhibition of contraction and whether the increase is mediated by the P4 receptor A (PR-A). These studies were conducted in colon-isolated colon muscle cells from human control and slow-transit constipation (STC) females and from guinea pigs. Muscle cell contraction was induced by CCK-8. Inhibition of contraction was induced by vasoactive intestinal polypeptide (VIP), and 8′bromo-c′AMP (8B-c′AMP) G protein levels were determined by Western blot. VIP-induced inhibition of contraction was greater in muscle cells from STC and P4-treated muscle cells. There were no differences in the inhibition induced by 8B-c′AMP between muscle cells from STC and P4-treated controls. The increased VIP-induced inhibition of muscle cells treated with P4 was blocked by pretreatment with PR-A antibodies and unaffected by PR-B antibodies. These antibodies had no effect on 8B-c′AMP induced-inhibition. The P4 upregulation of Gs proteins was blocked by PR-A antibodies and unaffected by PR-B antibodies. Similar results were obtained in muscle cells from guinea pig colons. We concluded that P4 upregulation of Gs proteins increases VIP-induced inhibition of contraction mediated by PR-A.
Esophageal pressures in acute lung injury: do they represent artifact or useful information about transpulmonary pressure, chest wall mechanics, and lung stress?
Authors: Loring Stephen H. , O'Donnell Carl R. , Behazin Negin , Malhotra Atul , Sarge Todd , Ritz Ray , Novack Victor , Talmor Daniel
Published: December 2009

Acute lung injury can be worsened by inappropriate mechanical ventilation, and numerous experimental studies suggest that ventilator-induced lung injury is increased by excessive lung inflation at end inspiration or inadequate lung inflation at end expiration. Lung inflation depends not only on airway pressures from the ventilator but, also, pleural pressure within the chest wall. Although esophageal pressure (Pes) measurements are often used to estimate pleural pressures in healthy subjects and patients, they are widely mistrusted and rarely used in critical illness. To assess the credibility of Pes as an estimate of pleural pressure in critically ill patients, we compared Pes measurements in 48 patients with acute lung injury with simultaneously measured gastric and bladder pressures (Pga and Pblad). End-expiratory Pes, Pga, and Pblad were high and varied widely among patients, averaging 18.6 ± 4.7, 18.4 ± 5.6, and 19.3 ± 7.8 cmH2O, respectively (mean ± SD). End-expiratory Pes was correlated with Pga ( P = 0.0004) and Pblad ( P = 0.0104) and unrelated to chest wall compliance. Pes-Pga differences were consistent with expected gravitational pressure gradients and transdiaphragmatic pressures. Transpulmonary pressure (airway pressure − Pes) was −2.8 ± 4.9 cmH2O at end exhalation and 8.3 ± 6.2 cmH2O at end inflation, values consistent with effects of mediastinal weight, gravitational gradients in pleural pressure, and airway closure at end exhalation. Lung parenchymal stress measured directly as end-inspiratory transpulmonary pressure was much less than stress inferred from the plateau airway pressures and lung and chest wall compliances. We suggest that Pes can be used to estimate transpulmonary pressures that are consistent with known physiology and can provide meaningful information, otherwise unavailable, in critically ill patients.
Intra-patient variability of thromboelastographic parameters following in vivo and ex vivo administration of recombinant activated factor VII in haemophilia patients. A multi-centre, randomised trial
Authors: Kenet Gili , Stenmo Camilla , Blemings Allan , Wegert Wolfgang , Goudemand Jenny , Krause Manuela , Schramm Wolfgang , Kirchmaier Carl , Martinowitz Uri
Published: December 2009

Thromboelastography methods have been used to predict or monitor treatment of haemophilia patients with recombinant activated factor VII (rFVIIa). However, neither of the two thromboelastographic methods (ROTEM and TEG) has as yet been validated. This multi-centre, randomised trial compared both methods in terms of intra- and inter-patient variability following in vivo and ex vivo rFVIIa administration to haemophilia A and B patients with and without inhibitors. Patients (≥16 years old) received the same intravenous rFVIIa dose (45, 90 or 180 μg/kg) twice, 1–12 weeks apart. Blood samples were collected pre-dose and 15, 60, 120 and 240 minutes post-dose for ROTEM and TEG analysis. Pre-dose samples were also spiked ex vivo with rFVIIa (0.6, 1.2 or 2.4 μg/ml), to correspond to the three in vivo doses. Twenty-six haemophilia A and four haemophilia B patients were enrolled. A significant treatment effect was observed with in vivo rFVIIa (p<0.05) with more pronounced effects in inhibitor (n=14) versus non-inhibitor (n=16) patients. There was a strong positive correlation between ROTEM and TEG parameters. Intra- and inter-patient variation was large for all thromboelastography parameters at all time points and rFVIIa doses. Intra-patient variation was generally lower for non-inhibitor than inhibitor patients, and lower following ex vivo spiking versus in vivo rFVIIa administration. In conclusion, there was a clear effect of rFVIIa on all thromboelastography parameters, but the large intra- and inter-patient variability following in vivo rFVIIa administration renders the use of our method unsuitable for dose-response prediction for haemophilia patients in the clinical setting.
The TRITON versus PLATO trials: Differences beyond platelet inhibition
Authors: Serebruany Victor
Published: December 2009

Clopidogrel monopoly as an exclusive oral antiplatelet agent used in combination with aspirin or as a monotherapy for treatment or/and prevention of occlusive thrombotic vascular events has been recently challenged. Based on the indirect comparison of TRITON and PLATO trial data, ticagrelor is clearly superior to prasugrel in a population of patients with acute coronary syndrome (ACS) because of absolute mortality reduction, realistic second myocardial infarction (MI) prevention, growing over time vascular outcome benefit, fewer haemorrhagic fatalities, potentially less coronary artery bypass graft (CABG)- related bleeding events, and lack of cancer risks. Despite an unfavourable immediate safety profile, ticagrelor has a lot of room to compensate for agitation, dyspnea, and ventricular pauses, if used in appropriate patients. It will be naïve and wrong to assume that ticagrelor will completely substitute clopidogrel, especially considering higher discontinu-ation rates after ticagrelor, generic competition, and other health economics issues. However, unless the regulatory authorities discover some unexpected serious flaws with PLATO, the ticagrelor will substantially change the present landscape of oral antiplatelet therapy, especially in high-risk patients, diabetics, and those with repeated vascular events including stent thrombosis. In contrast, a too exclusive trial design, a lack of persistent vascular benefit despite issues with event adjudication, growing-over-time bleeding complications, an issue with cancer, and finally an increase in mortality risk among unstable angina and non ST-elevated myocardial infarction will likely prevent a broad prasugrel implementation, unless more reassuring evidence becomes available.
Pathways by Which Reconstituted High-Density Lipoprotein Mobilizes Free Cholesterol From Whole Body and From Macrophages
Authors: Cuchel Marina , Lund-Katz Sissel , de la Llera-Moya Margarita , Millar John S. , Chang David , Fuki Ilia , Rothblat George H. , Phillips Michael C. , Rader Daniel J.
Published: December 2009

Objective—

Reconstituted high-density lipoprotein (rHDL) is of interest as a potential novel therapy for atherosclerosis because of its ability to promote free cholesterol (FC) mobilization after intravenous administration. We performed studies to identify the underlying molecular mechanisms by which rHDL promote FC mobilization from whole body in vivo and macrophages in vitro.

Methods and Results—

Wild-type (WT), SR-BI knockout (KO), ABCA1 KO, and ABCG1 KO mice received either rHDL or phosphate-buffered saline intravenously. Blood was drawn before and at several time points after injection for apolipoprotein A-I, phosphatidylcholine, and FC measurement. In WT mice, serum FC peaked at 20 minutes and rapidly returned toward baseline levels by 24 hours. Unexpectedly, ABCA1 KO and ABCG1 KO mice did not differ from WT mice regarding the kinetics of FC mobilization. In contrast, in SR-BI KO mice the increase in FC level at 20 minutes was only 10% of that in control mice (
P
<0.01). Bone marrow-derived macrophages from WT, SR-BI O, ABCA1 KO, and ABCG1 KO mice were incubated in vitro with rHDL and cholesterol efflux was determined. Efflux from SR-BI KO and ABCA1 KO macrophages was not different from WT macrophages. In contrast, efflux from ABCG1 KO macrophages was ≈50% lower as compared with WT macrophages (
P
<0.001).

Conclusion—

The bulk mobilization of FC observed in circulation after rHDL administration is primarily mediated by SR-BI. However, cholesterol mobilization from macrophages to rHDL is primarily mediated by ABCG1.
Effects of Mechanical Stress and Carvedilol in Lamin A/C–Deficient Dilated Cardiomyopathy
Authors: Chandar Suchitra , Yeo Li Sze , Leimena Christiana , Tan Ju-Chiat , Xiao Xiao-Hui , Nikolova-Krstevski Vesna , Yasuoka Yoshinori , Gardiner-Garden Margaret , Wu Jianxin , Kesteven Scott , Karlsdotter Lina , Natarajan Shweta , Carlton Arthur , Rainer Stephen , Feneley Michael P. , Fatkin Diane
Published: December 2009

Rationale
:

Mutations in the
LMNA
gene, which encodes the nuclear lamina proteins lamin A and lamin C, are the most common cause of familial dilated cardiomyopathy (DCM). Mechanical stress-induced apoptosis has been proposed as the mechanism underpinning DCM in lamin A/C–deficient hearts, but supporting in vivo evidence has been lacking.

Objective
:

Our aim was to study interventions to modify mechanical stress in heterozygous
Lmna
knockout (
Lmna
+/−
) mice.

Methods and Results
:

Cardiac structure and function were evaluated before and after exercise training, thoracic aortic constriction, and carvedilol treatment.
Lmna
+/−
mice develop adult-onset DCM with relatively more severe disease in males.
Lmna
+/−
cardiomyocytes show altered nuclear morphology and perinuclear desmin organization, with enhanced responses to hypo-osmotic stress indicative of cytoskeletal instability. Despite these structural defects that provide a template for mechanical stress-induced damage, young
Lmna
+/−
mice subjected to 6 weeks of moderate or strenuous exercise training did not show induction of apoptosis or accelerated DCM. In contrast, regular moderate exercise attenuated DCM development in male
Lmna
+/−
mice. Sustained pressure overload generated by thoracic aortic constriction depressed ventricular contraction in young wild-type and
Lmna
+/−
mice with no sex or genotype differences in the time-course or severity of response. Treatment of male
Lmna
+/−
mice from 12 to 40 weeks with the β-blocker, carvedilol, prevented the dilatation and contractile dysfunction that was observed in placebo-treated mice.

Conclusions
:

These data suggest that factors other than mechanical stress-induced apoptosis contribute to DCM and provide the first demonstration that regular moderate exercise and carvedilol can modify disease progression in lamin A/C–deficient hearts.
Spontaneous Motor Rhythms of the Back and Legs in a Patient With a Complete Spinal Cord Transection
Authors: Nadeau Sylvie , Jacquemin Géraldine , Fournier Christine , Lamarre Yves , Rossignol Serge
Published: December 2009

Background. Spontaneous activity originating from the spinal cord has been sporadically reported in humans. Objectives. Investigation of such rhythmic activity of the trunk and legs in a 49-year-old male patient who had a complete severance of the spinal cord at the fifth thoracic vertebra. Methods. A multichannel electromyography (EMG) study was performed together with kinematics measurements obtained from an Optotrak system. Results. Episodes of rhythmic trunk and lower limb movements started 6 to 7 years after the spinal lesion, recurred at 2 to 3 month intervals, and continued uninterrupted for 2 to 3 days despite continuous delivery of intrathecal baclofen. Several muscles discharged more or less synchronously on both sides but others clearly alternated, for instance, between hip flexors and knee or ankle extensors. Sensory stimuli (hip repositioning or skin pinch) altered significantly the baseline rhythm of about 1 Hz. The patient had both hips injected with corticosteroids and was free of these episodic rhythmic crises for more than 6 months. Conclusion. The rhythmic activity observed in the patient appeared related to the activation of a spinal pattern generator akin to what has been described in most animal species after complete spinal lesions.
Assessing the utility of whole-genome amplified serum DNA for array-based high throughput genotyping
Authors: Bucasas Kristine L , Pandya Gagan A , Pradhan Sonal , Fleischmann Robert D , Peterson Scott N , Belmont John W
Published: December 2009

Background

Whole genome amplification (WGA) offers new possibilities for genome-wide association studies where limited DNA samples have been collected. This study provides a realistic and high-precision assessment of WGA DNA genotyping performance from 20-year old archived serum samples using the Affymetrix Genome-Wide Human SNP Array 6.0 (SNP6.0) platform.

Results

Whole-genome amplified (WGA) DNA samples from 45 archived serum replicates and 5 fresh sera paired with non-amplified genomic DNA were genotyped in duplicate. All genotyped samples passed the imposed QC thresholds for quantity and quality. In general, WGA serum DNA samples produced low call rates (45.00 +/- 2.69%), although reproducibility for successfully called markers was favorable (concordance = 95.61 +/- 4.39%). Heterozygote dropouts explained the majority (>85% in technical replicates, 50% in paired genomic/serum samples) of discordant results. Genotyping performance on WGA serum DNA samples was improved by implementation of Corrected Robust Linear Model with Maximum Likelihood Classification (CRLMM) algorithm but at the loss of many samples which failed to pass its quality threshold. Poor genotype clustering was evident in the samples that failed the CRLMM confidence threshold.

Conclusions

We conclude that while it is possible to extract genomic DNA and subsequently perform whole-genome amplification from archived serum samples, WGA serum DNA did not perform well and appeared unsuitable for high-resolution genotyping on these arrays.
YsxC, an essential protein in Staphylococcus aureus crucial for ribosome assembly/stability
Authors: Cooper Elizabeth L , García-Lara Jorge , Foster Simon J
Published: December 2009

Background

Bacterial growth and division requires a core set of essential proteins, several of which are still of unknown function. They are also attractive targets for the development of new antibiotics. YsxC is a member of a family of GTPases highly conserved across eubacteria with a possible ribosome associated function.

Results

Here, we demonstrate by the creation of a conditional lethal mutant that ysxC is apparently essential for growth in S. aureus. To begin to elucidate YsxC function, a translational fusion of YsxC to the CBP-ProteinA tag in the staphylococcal chromosome was made, enabling Tandem Affinity Purification (TAP) of YsxC-interacting partners. These included the ribosomal proteins S2, S10 and L17, as well as the β' subunit of the RNA polymerase. YsxC was then shown to copurify with ribosomes as an accessory protein specifically localizing to the 50 S subunit. YsxC depletion led to a decrease in the presence of mature ribosomes, indicating a role in ribosome assembly and/or stability in S. aureus.

Conclusions

In this study we demonstrate that YsxC of S. aureus localizes to the ribosomes, is crucial for ribosomal stability and is apparently essential for the life of S. aureus.
Multilocus sequence typing supports the hypothesis that Ochrobactrum anthropi displays a human-associated subpopulation
Authors: Romano Sara , Aujoulat Fabien , Jumas-Bilak Estelle , Masnou Agnès , Jeannot Jean-Luc , Falsen Enevold , Marchandin Hélène , Teyssier Corinne
Published: December 2009

Background

Ochrobactrum anthropiis a versatile bacterial species with strains living in very diverse habitats. It is increasingly recognized as opportunistic pathogen in hospitalized patients. The population biology of the species particularly with regard to the characteristics of the human isolates is being investigated. To address this issue, we proposed a polyphasic approach consisting in Multi-Locus Sequence Typing (MLST), multi-locus phylogeny, genomic-based fingerprinting by pulsed-field gel electrophoresis (PFGE) and antibiotyping.

Results

We tested a population of 70O. anthropiclinical (n = 43) and environmental (n = 24) isolates as well as the type strainO. anthropiATCC49188Tand 2 strains ofOchrobactrum lupiniandOchrobactrum cytisiisolated from plant nodules. A Multi-Locus Sequence Typing (MLST) scheme forO. anthropiis proposed here for the first time. It was based on 7 genes (3490 nucleotides) evolving mostly by neutral mutations. The MLST approach suggested an epidemic population structure. A major clonal complex corresponded to a human-associated lineage since it exclusively contained clinical isolates. Genomic fingerprinting separated isolates displaying the same sequence type but it did not detect a population structure that could be related to the origin of the strains. None of the molecular method allowed the definition of particular lineages associated to the host-bacteria relationship (carriage, colonisation or infection). Antibiotyping was the least discriminative method.

Conclusion

The results reveal a human-associated subpopulation in our collection of strains. The emergence of this clonal complex was probably not driven by the antibiotic selective pressure. Therefore, we hypothesise that the versatile speciesO. anthropicould be considered as a human-specialized opportunistic pathogen.
Adolescent type 1 Diabetes cardio-renal Intervention Trial (AdDIT)
Authors:   The Adolescent type 1 Diabetes cardio-renal Intervention Trial Research Group
Published: December 2009

Background

The prognosis for young people diagnosed with diabetes during childhood remains poor and this is mainly related to the long-term risk of developing vascular complications.

Microalbuminuria identifies subjects at risk for diabetic nephropathy (DN) and cardiovascular disease (CVD). It is often detected in adolescence but is rarely treated before the age of 18 years, as at the end of puberty albumin excretion may decline and in some subjects will return into the normal range. However, evidence indicates that subjects with both transient and persistent microalbuminuria have experienced renal damage during puberty and thus reno-protection to prevent long-term complications is warranted. In adults with diabetes and microalbuminuria, the use of angiotensin converting enzyme inhibitors (ACEI) and Statins is increasing, and in order to determine whether these agents are of value in the adolescent population a large randomized controlled clinical trial is needed.

Methods/Design

The Adolescent type 1 Diabetes cardio-renal Intervention Trial (AdDIT) is a multi-center, randomized, double-blind, placebo-controlled trial of ACEI and Statin therapy in adolescents with type 1 diabetes. 500 high-risk adolescents, defined on the basis of their albumin excretion, are randomized to receive either ACEI (Quinapril) or Statins (Atorvastatin) or combination therapy or placebo for 3-4 years. There will also be a parallel open observational study, based on the follow-up of 400 low-risk non-randomized adolescents. The major endpoint of the study is the change in albumin excretion; secondary endpoints include markers of CVD, renal function, retinopathy, quality of life combined with assessment of compliance and potential health economic benefits.

Discussion

AdDIT will provide important data on the potential renal and cardiovascular protective effects of ACEI and Statins in high-risk adolescents. Long-term follow-up of the randomized subjects will provide direct evidence of disease outcomes, in addition to the data on early surrogate measures of DN and CVD. Follow-up of non-randomized low-risk subjects will determine the potential impact of intervention on DN and CVD. AdDIT will help to determine whether, in addition to encouraging young people to achieve good glycaemic control, pharmacological cardio-renal protection should also be implemented.

EudraCT Number

2007-001039-72

Trial Registration Number

ISRCTN91419926
The structure of pyogenecin immunity protein, a novel bacteriocin-like immunity protein from Streptococcus pyogenes
Authors: Chang Changsoo , Coggill Penny , Bateman Alex , Finn Robert D , Cymborowski Marcin , Otwinowski Zbyszek , Minor Wladek , Volkart Lour , Joachimiak Andrzej
Published: December 2009

Background

Many Gram-positive lactic acid bacteria (LAB) produce anti-bacterial peptides and small proteins called bacteriocins, which enable them to compete against other bacteria in the environment. These peptides fall structurally into three different classes, I, II, III, with class IIa being pediocin-like single entities and class IIb being two-peptide bacteriocins. Self-protective cognate immunity proteins are usually co-transcribed with these toxins. Several examples of cognates for IIa have already been solved structurally. Streptococcus pyogenes, closely related to LAB, is one of the most common human pathogens, so knowledge of how it competes against other LAB species is likely to prove invaluable.

Results

We have solved the crystal structure of the gene-product of locus Spy_2152 from S. pyogenes, (PDB:2fu2), and found it to comprise an anti-parallel four-helix bundle that is structurally similar to other bacteriocin immunity proteins. Sequence analyses indicate this protein to be a possible immunity protein protective against class IIa or IIb bacteriocins. However, given that S. pyogenes appears to lack any IIa pediocin-like proteins but does possess class IIb bacteriocins, we suggest this protein confers immunity to IIb-like peptides.

Conclusions

Combined structural, genomic and proteomic analyses have allowed the identification and in silico characterization of a new putative immunity protein from S. pyogenes, possibly the first structure of an immunity protein protective against potential class IIb two-peptide bacteriocins. We have named the two pairs of putative bacteriocins found in S. pyogenes pyogenecin 1, 2, 3 and 4.
Effects of intensive arm training with the rehabilitation robot ARMin II in chronic stroke patients: four single-cases
Authors: Staubli Patricia , Nef Tobias , Klamroth-Marganska Verena , Riener Robert
Published: December 2009

Background

Robot-assisted therapy offers a promising approach to neurorehabilitation, particularly for severely to moderately impaired stroke patients. The objective of this study was to investigate the effects of intensive arm training on motor performance in four chronic stroke patients using the robot ARMin II.

Methods

ARMin II is an exoskeleton robot with six degrees of freedom (DOF) moving shoulder, elbow and wrist joints. Four volunteers with chronic (≥ 12 months post-stroke) left side hemi-paresis and different levels of motor severity were enrolled in the study. They received robot-assisted therapy over a period of eight weeks, three to four therapy sessions per week, each session of one hour.

Patients 1 and 4 had four one-hour training sessions per week and patients 2 and 3 had three one-hour training sessions per week. Primary outcome variable was the Fugl-Meyer Score of the upper extremity Assessment (FMA), secondary outcomes were the Wolf Motor Function Test (WMFT), the Catherine Bergego Scale (CBS), the Maximal Voluntary Torques (MVTs) and a questionnaire about ADL-tasks, progress, changes, motivation etc.

Results

Three out of four patients showed significant improvements (p < 0.05) in the main outcome. The improvements in the FMA scores were aligned with the objective results of MVTs. Most improvements were maintained or even increased from discharge to the six-month follow-up.

Conclusion

Data clearly indicate that intensive arm therapy with the robot ARMin II can significantly improve motor function of the paretic arm in some stroke patients, even those in a chronic state. The findings of the study provide a basis for a subsequent controlled randomized clinical trial.
Oral malignant melanomas and other head and neck neoplasms in Danish dogs - data from the Danish Veterinary Cancer Registry
Authors: Brønden Louise B , Eriksen Thomas , Kristensen Annemarie T
Published: December 2009

Background

Head and neck cancers (HNC) are relatively common and often very serious diseases in both dogs and humans. Neoplasms originating in the head and neck region are a heterogeneous group. HNC often has an unfavourable prognosis and the proximity of the tissue structures renders extirpation of tumours with sufficient margins almost incompatible with preservation of functionality. In humans oral malignant melanoma (OMM) is extremely rare, but represents a particular challenge since it is highly aggressive as is the canine counterpart, which thus may be of interest as a spontaneous animal model.

Methods

Canine cases entered in the Danish Veterinary Cancer Registry (DVCR) from May 15th 2005 through February 29th 2008 were included in this study. Fisher's exact test was used to compare proportions of HNC in dogs and humans as well as proportions of surgically treated cases of OMM and squamous cell carcinomas (SCC). Also the proportions of benign and malignant neoplasms of different locations in dogs were compared using Fisher's exact test.

Results

A total of 1768 cases of neoplasias (679 malignant, 826 benign, 263 unknown) were submitted. Of all neoplasias HNC accounted for 7.2% (n = 128). Of these, 64 (50%) were malignant and 44 (34%) benign. The most common types of malignant neoplasia were SCC (18; 28% of malignant), OMM (13; 20% of malignant), soft tissue sarcoma (11; 17% of malignant) and adenocarcinoma (5; 11% of malignant). The most common types of benign neoplasms were adenoma (7; 16% of benign), polyps (6; 14% of benign) and fibroma (5; 11% of benign).

Conclusions

In the current study, the proportion of neoplasia in the head and neck region in dogs in Denmark was similar to other canine studies and significantly more common than in humans with a large proportion of malignancies. Spontaneous HNC in dogs thus, may serve as a model for HNC in humans.

Canine OMM is a spontaneous cancer in an outbred, immune-competent large mammal population and could be a clinical model for OMM in humans.
The role of renal biopsy in a patient with multiple synchronous cancers: a case report
Authors: Kaprin Andrey , Nesterov Pavel , Fadeev Andrey
Published: December 2009

A 51-year-old male with a long history of tobacco smoking presented to the outpatient clinic with left renal colic. A renal ultrasound revealed a mass in the left kidney. The patient was admitted to surgical clinic of Russian Scientific Center of Roentgen-Radiology of Rosmedtechnology. A renal biopsy and subsequent histopathological tests revealed adenocarcinoma of the right kidney of most likely metastatic origin. This discovery has lead to vigorous diagnostics search for the primary tumor. Finally, the following diagnosis was established: Primarily-multiple synchronous cancer: cancer of the left kidney T1N0M0, cancer of the thyroid gland T2N0M1, metastasis to the right kidney and lungs. The patient had left kidney and thyroid gland removed and was successfully treated with radioiodine therapy. The patient remains alive and well 7 months since his admission to our clinic. We report this case to emphasize the importance of the renal biopsy and thorough histological analysis, which made it possible to diagnose thyroid cancer in this patient.
Argon: Neuroprotection in in vitro models of cerebral ischemia and traumatic brain injury
Authors: Loetscher Philip D , Rossaint Jan , Rossaint Rolf , Weis Joachim , Fries Michael , Fahlenkamp Astrid , Ryang Yu-Mi , Grottke Oliver , Coburn Mark
Published: December 2009

Introduction

Recently, it has been shown in several experimental settings that the noble gases xenon and helium have neuroprotective properties. In this study we tested the hypothesis that the noble gas argon has a neuroprotective potential as well. Since traumatic brain injury and stroke are widespread and generate an enormous economic and social burden, we investigated the possible neuroprotective effect in in vitro models of traumatic brain injury and cerebral ischemia.

Methods

Organotypic hippocampal slice cultures from mice pups were subjected to either oxygen-glucose deprivation or to a focal mechanical trauma and subsequently treated with three different concentrations (25, 50 and 74%) of argon immediately after trauma or with a two-or-three-hour delay. After 72 hours of incubation tissue injury assessment was performed using propidium iodide, a staining agent that becomes fluorescent when it diffuses into damaged cells via disintegrated cell membranes.

Results

We could show argon's neuroprotective effects at different concentrations when applied directly after oxygen-glucose deprivation or trauma. Even three hours after application, argon was still neuroprotective.

Conclusions

Argon showed a neuroprotective effect in both in vitro models of oxygen-glucose deprivation and traumatic brain injury. Our promising results justify further in vivo animal research.
Auxin modulates the transition from the mitotic cycle to the endocycle in Arabidopsis
Authors: Ishida Takashi , Adachi Sumiko , Yoshimura Mika , Shimizu Kohei , Umeda Masaaki , Sugimoto Keiko
Published: December 2009

Amplification of genomic DNA by endoreduplication often marks the initiation of cell differentiation in animals and plants. The transition from mitotic cycles to endocycles should be developmentally programmed but how this process is regulated remains largely unknown. We show that the plant growth regulator auxin modulates the switch from mitotic cycles to endocycles in Arabidopsis; high levels of TIR1-AUX/IAA-ARF-dependent auxin signalling are required to repress endocycles, thus maintaining cells in mitotic cycles. By contrast, lower levels of TIR1-AUX/IAA-ARF-dependent auxin signalling trigger an exit from mitotic cycles and an entry into endocycles. Our data further demonstrate that this auxin-mediated modulation of the mitotic-to-endocycle switch is tightly coupled with the developmental transition from cell proliferation to cell differentiation in the Arabidopsis root meristem. The transient reduction of auxin signalling by an auxin antagonist PEO-IAA rapidly downregulates the expression of several core cell cycle genes, and we show that overexpressing one of the genes, CYCLIN A2;3 (CYCA2;3), partially suppresses an early initiation of cell differentiation induced by PEO-IAA. Taken together, these results suggest that auxin-mediated mitotic-to-endocycle transition might be part of the developmental programmes that balance cell proliferation and cell differentiation in the Arabidopsis root meristem.
Interaction betweenDrosophilabZIP proteins Atf3 and Jun prevents replacement of epithelial cells during metamorphosis
Authors: Sekyrova Petra , Bohmann Dirk , Jindra Marek , Uhlirova Mirka
Published: December 2009

Epithelial sheet spreading and fusion underlie important developmental processes. Well-characterized examples of such epithelial morphogenetic events have been provided by studies in Drosophila, and include embryonic dorsal closure, formation of the adult thorax and wound healing. All of these processes require the basic region-leucine zipper (bZIP) transcription factors Jun and Fos. Much less is known about morphogenesis of the fly abdomen, which involves replacement of larval epidermal cells (LECs) with adult histoblasts that divide, migrate and finally fuse to form the adult epidermis during metamorphosis. Here, we implicate Drosophila Activating transcription factor 3 (Atf3), the single ortholog of human ATF3 and JDP2 bZIP proteins, in abdominal morphogenesis. During the process of the epithelial cell replacement, transcription of the atf3 gene declines. When this downregulation is experimentally prevented, the affected LECs accumulate cell-adhesion proteins and their extrusion and replacement with histoblasts are blocked. The abnormally adhering LECs consequently obstruct the closure of the adult abdominal epithelium. This closure defect can be either mimicked and further enhanced by knockdown of the small GTPase Rho1 or, conversely, alleviated by stimulating ecdysone steroid hormone signaling. Both Rho and ecdysone pathways have been previously identified as effectors of the LEC replacement. To elicit the gain-of-function effect, Atf3 specifically requires its binding partner Jun. Our data thus identify Atf3 as a new functional partner of Drosophila Jun during development.
C. elegans STRADα and SAD cooperatively regulate neuronal polarity and synaptic organization
Authors: Kim Joanne S. M. , Hung Wesley , Narbonne Patrick , Roy Richard , Zhen Mei
Published: December 2009

Neurons are polarized cells with morphologically and functionally distinct axons and dendrites. The SAD kinases are crucial for establishing the axon-dendrite identity across species. Previous studies suggest that a tumour suppressor kinase, LKB1, in the presence of a pseudokinase, STRADα, initiates axonal differentiation and growth through activating the SAD kinases in vertebrate neurons. STRADα was implicated in the localization, stabilization and activation of LKB1 in various cell culture studies. Its in vivo functions, however, have not been examined. In our present study, we analyzed the neuronal phenotypes of the first loss-of-function mutants for STRADα and examined their genetic interactions with LKB1 and SAD in C. elegans. Unexpectedly, only the C. elegans STRADα, STRD-1, functions exclusively through the SAD kinase, SAD-1, to regulate neuronal polarity and synaptic organization. Moreover, STRD-1 tightly associates with SAD-1 to coordinate its synaptic localizations. By contrast, the C. elegans LKB1, PAR-4, also functions in an additional genetic pathway independently of SAD-1 and STRD-1 to regulate neuronal polarity. We propose that STRD-1 establishes neuronal polarity and organizes synaptic proteins in a complex with the SAD-1 kinase. Our findings suggest that instead of a single, linear genetic pathway, STRADα and LKB1 regulate neuronal development through multiple effectors that are shared in some cellular contexts but distinct in others.
Role of Notch signaling in establishing the hemilineages of secondary neurons in Drosophila melanogaster
Authors: Truman James W. , Moats Wanda , Altman Janet , Marin Elizabeth C. , Williams Darren W.
Published: December 2009

The secondary neurons generated in the thoracic central nervous system of Drosophila arise from a hemisegmental set of 25 neuronal stem cells, the neuroblasts (NBs). Each NB undergoes repeated asymmetric divisions to produce a series of smaller ganglion mother cells (GMCs), which typically divide once to form two daughter neurons. We find that the two daughters of the GMC consistently have distinct fates. Using both loss-of-function and gain-of-function approaches, we examined the role of Notch signaling in establishing neuronal fates within all of the thoracic secondary lineages. In all cases, the ‘A’ (NotchON) sibling assumes one fate and the ‘B’ (NotchOFF) sibling assumes another, and this relationship holds throughout the neurogenic period, resulting in two major neuronal classes: the A and B hemilineages. Apparent monotypic lineages typically result from the death of one sibling throughout the lineage, resulting in a single, surviving hemilineage. Projection neurons are predominantly from the B hemilineages, whereas local interneurons are typically from A hemilineages. Although sibling fate is dependent on Notch signaling, it is not necessarily dependent on numb, a gene classically involved in biasing Notch activation. When Numb was removed at the start of larval neurogenesis, both A and B hemilineages were still generated, but by the start of the third larval instar, the removal of Numb resulted in all neurons assuming the A fate. The need for Numb to direct Notch signaling correlated with a decrease in NB cell cycle time and may be a means for coping with multiple sibling pairs simultaneously undergoing fate decisions.
Hematopoietic stem cells in Drosophila
Authors: Minakhina Svetlana , Steward Ruth
Published: December 2009

The Drosophila lymph gland, the source of adult hemocytes, is established by mid-embryogenesis. During larval stages, a pool of pluripotent hemocyte precursors differentiate into hemocytes that are released into circulation upon metamorphosis or in respon to immune challenge. This process is controlled by the posterior signaling center (PSC), which is reminiscent of the vertebrate hematopoietic stem cell niche. Using lineage analysis, we identified bona fide hematopoietic stem cells (HSCs) in the lymph glands of embryos and young larvae, which give rise to a hematopoietic lineage. These lymph glands also contain pluripotent precursor cells that undergo a limited number of mitotic divisions and differentiate. We further find that the conserved factor Zfrp8/PDCD2 is essential for the maintenance of the HSCs, but dispensable for their daughter cells, the pluripotent precursors. Zfrp8/PDCD2 is likely to have similar functions in hematopoietic stem cell maintenance in vertebrates.