bluuebunny/crossref_metadata_2025 huggingface dataset:
Body mass index and outcome in patients with coronary, cerebrovascular, or peripheral artery disease: findings from the FRENA registry
Authors: Barba Raquel , Bisbe Josep , Pedrajas José Nicolas Alcalá , Toril Jesús , Monte Rafael , Muñoz-Torrero Juan Francisco Sánchez , Monreal Manuel ,   the FRENA Investigators∗
Published: July 2009

Background

The relationship between body mass index (BMI) and mortality in patients with established arterial disease remains controversial.

Methods

FRENA is an ongoing, observational registry of consecutive outpatients with coronary artery disease (CAD), cerebrovascular disease, or peripheral artery disease (PAD). We examined the prognostic importance of accepted BMI categories on outcome among patients in the FRENA registry.

Results

In April 2008, 2274 patients (mean age, 66 years) had been enrolled, of whom 14 (0.6%) were underweight; 533 (23%) normal; 1051 (46%) overweight; and 676 (30%) were obese. Over a mean follow-up of 14 months, the incidence of major cardiovascular events (myocardial infarction, ischemic stroke, or critical limb ischemia) per 100 patient-years was: 7.1 [95% confidence interval (CI): 0.4–35]; 11 (95% CI: 8.4–14); 6.9 (95% CI: 5.6–8.5); and 8.5 (95% CI: 6.6–11), respectively. Their cardiovascular mortality was: 7.1 (95% CI: 0.4–35); 4.1 (95% CI: 5.9–11); 1.3 (95% CI: 0.9–2.3); and 1.5 (95% CI: 1.4–3.5), respectively. On multivariate analysis, the hazard ratio for cardiovascular mortality was: 2.2 (95% CI: 0.3–17); 1.0 (reference); 0.37 (95% CI: 0.20–0.69); and 0.37 (95% CI: 0.18–0.73), respectively. Survival benefit was only found in patients with CAD or PAD. Weight loss had little influence on outcome.

Conclusion

Patients with CAD or PAD (not those with cerebrovascular disease) have an inverse correlation between BMI and cardiovascular mortality, even after adjusting for confounding variables.
Habitual physical activity is associated with endothelial function and endothelial progenitor cells in patients with stable coronary artery disease
Authors: Luk Ting-Hin , Dai Yuk-Ling , Siu Chung-Wah , Yiu Kai-Hang , Chan Hiu-Ting , Fong Daniel Yee-Tak , Lee Stephen W.L. , Li Sheung-Wai , Tam Sidney , Lau Chu-Pak , Tse Hung-Fat
Published: July 2009

Background

Exercise training reduces mortality in patients with coronary artery disease (CAD); however, the impact of habitual physical activity level (PAL) on vascular endothelial function and circulating endothelial progenitor cells (EPCs) remain unknown.

Methods

We assessed habitual PAL using a validated International Physical Activity Questionnaire in 116 patients (67.8 ± 9.5 years; 81% male) with stable CAD and preserved left ventricular ejection fraction ≥ 45%. The number of circulating CD34/KDR+ and CD133/KDR+ EPCs was determined by flow cytometry, and brachial artery flow-mediated dilation (FMD) was measured.

Results

The mean PAL of CAD patients with 1644 MET min/week (where MET is metabolic equivalents). With higher habitual PAL tertiles, there were significant linear trends of increased FMD ( P = 0.001) and CD133/KDR+ EPCs ( P = 0.03), but not of CD34/KDR+ EPCs. Patients with the highest tertile of PAL were associated with an absolute increase of 1.89% in FMD (relative increase 68%, P = 0.003) and 0.12% in CD133/KDR+ EPCs (relative increase 44%, P = 0.01) compared with those in the lowest tertile of PAL, after adjusting for age, sex, presence of hypertension, diabetes mellitus, hypercholesterolemia, smoking, and the use of medications including statins. However, neither CD34/KDR+ nor CD133/KDR+ EPCs significantly correlated with FMD.

Conclusion

This study showed that higher habitual PAL in patients with CAD was associated with higher FMD and EPC count. Nonetheless, FMD only significantly correlated with increased PAL, but not EPC, suggesting that increased physical activity improves endothelial function through mechanisms other than increasing EPC count.
International open-label studies to assess the efficacy and safety of single-pill amlodipine/atorvastatin in attaining blood pressure and lipid targets recommended by country-specific guidelines: the JEWEL programme
Authors: Hobbs Frederick D. Richard , Gensini Gianfranco , Mancini Giovanni B. John , Manolis Athanasios J. , Bauer Beverly , Genest Jacques , Feldman Ross D. , Harvey Peter , Jenssen Trond G. , Silva Pedro Marques da ,   for the JEWEL Study Group
Published: July 2009

Background

Single-pill amlodipine/atorvastatin targets the two most common modifiable cardiovascular risk factors, hypertension and dyslipidaemia. We evaluated the clinical utility of this single pill to help patients across Europe and Canada achieve country-specific targets for blood pressure (BP) and low-density lipoprotein cholesterol (LDL-C).

Design

Two 16-week, open-label studies conducted in 122 study centres across the United Kingdom and Canada (JEWEL 1) and 113 centres across 11 European countries (JEWEL 2).

Methods

Patients with uncontrolled BP and controlled/uncontrolled LDL-C qualifying for treatment according to local governing guidelines were administered single-pill amlodipine/atorvastatin with appropriate lifestyle modification. Eight dosages of amlodipine/atorvastatin (5/10–10/80 mg) were titrated to achieve country-specific BP and LDL-C targets. The primary outcome was the percentage of patients reaching country-specific BP and LDL-C targets in 16 weeks.

Results

Among 2245 patients enrolled in the studies (JEWEL 1, n = 1138; JEWEL 2, n = 1107), 62.9% in JEWEL 1 and 50.6% in JEWEL 2 achieved both country-specific BP and LDL-C goals. BP was reduced by 20.4/10.7 and 21.8/12.6 mmHg in JEWEL 1 and JEWEL 2, respectively, and reductions in LDL-C were 0.90 mmol/l (34.8 mg/dl) and 1.09 mmol/l (42.2 mg/dl), respectively. The most common adverse events were peripheral oedema (11.0%), joint swelling (2.9%) and headache (2.9%), of which, only oedema was linked to study treatment.

Conclusion

Single-pill amlodipine/atorvastatin is an effective and well-tolerated treatment, which in a real-world setting helped more than half of the patients achieve both BP and LDL-C targets as recommended by local guidelines. Although fewer patients met their goals in JEWEL 2 than JEWEL 1, reductions in BP and LDL-C were slightly greater in JEWEL 2, suggesting that the observed differences are likely because of more stringent targets in Europe than in the UK/Canada.
Influence of angiotensinogen and angiotensin-converting enzyme polymorphisms on cardiac hypertrophy and improvement on maximal aerobic capacity caused by exercise training
Authors: Alves Guilherme B. , Oliveira Edilamar M. , Alves Cleber R. , Rached Heron R.S. , Mota Glória F.A. , Pereira Alexandre C. , Rondon Maria U. , Hashimoto Nara Y. , Azevedo Luciene F. , Krieger José Eduardo , Negrão Carlos Eduardo
Published: July 2009

Background

The allele threonine (T) of the angiotensinogen has been associated with ventricular hypertrophy in hypertensive patients and soccer players. However, the long-term effect of physical exercise in healthy athletes carrying the T allele remains unknown. We investigated the influence of methionine (M) or T allele of the angiotensinogen and D or I allele of the angiotensin-converting enzyme on left-ventricular mass index (LVMI) and maximal aerobic capacity in young healthy individuals after long-term physical exercise training.

Design

Prospective clinical trial.

Methods

Eighty-three policemen aged between 20 and 35 years (mean ± SD 26 ± 4.5 years) were genotyped for the M235T gene angiotensinogen polymorphism (TT, n = 25; MM/MT, n = 58) and angiotensin-converting enzyme gene insertion/deletion (I/D) polymorphism (II, n = 18; DD/DI, n = 65). Left-ventricular morphology was evaluated by echocardiography and maximal aerobic capacity (VO2peak) by cardiopulmonary exercise test before and after 17 weeks of exercise training (50–80% VO2peak).

Results

Baseline VO2peak and LVMI were similar between TT and MM/MT groups, and II and DD/DI groups. Exercise training increased significantly and similarly VO2peak in homozygous TT and MM/MT individuals, and homozygous II and DD/DI individuals. In addition, exercise training increased significantly LVMI in TT and MM/MT individuals (76.5 ± 3 vs. 86.7 ± 4, P = 0.00001 and 76.2 ± 2 vs. 81.4 ± 2, P = 0.00001, respectively), and II and DD/DI individuals (77.7 ± 4 vs. 81.5 ± 4, P = 0.0001 and 76 ± 2 vs. 83.5 ± 2, P = 0.0001, respectively). However, LVMI in TT individuals was significantly greater than in MM/MT individuals ( P = 0.04). LVMI was not different between II and DD/DI individuals.

Conclusion

Left-ventricular hypertrophy caused by exercise training is exacerbated in homozygous TT individuals with angiotensinogen polymorphism.
Prospective studies on the relationship between high-density lipoprotein cholesterol and cardiovascular risk: a systematic review
Authors: Chirovsky Diana R. , Fedirko Veronika , Cui Yadong , Sazonov Vasilisa , Barter Philip
Published: July 2009

Epidemiological studies have extensively evaluated the association between high-density lipoprotein cholesterol (HDL-C) and cardiovascular disease (CVD) risk. The objective of this systematic review was to enumerate the number of original prospective studies that showed a significant association between HDL-C and CVD risk and provided evidence of the consistency of this association across other lipid risk factors. A systematic MEDLINE literature search identified 53 prospective cohort and five nested case-control studies that provided multivariate assessments of the association between HDL-C and CVD risk. Among these 58 prospective studies, 31 studies found a significant inverse association between HDL-C and CVD risk for all CVD outcomes and subpopulations studied, whereas 17 studies found a significant association for some CVD outcomes and/or subpopulations assessed. The ratio of studies that found a significant association out of the total studies identified was similar across all CVD outcomes, although there was less evidence for stroke and atherosclerotic outcomes. Only seven studies tested for the consistency of this association across other lipid risk factors, of which six studies suggested that the association was consistent across other lipid levels. In conclusion, the association between HDL-C and CVD risk is significant and strong, although further evidence may be needed to establish whether this association is consistent across other lipid risk factors. Furthermore, uncertainties remain regarding the mechanism in which HDL-C exerts its effects, suggesting a need for further research focused on new methods for reliable measurement.
Intratest reliability and test–retest reproducibility of the oxygen uptake efficiency slope in healthy participants
Authors: Laethem Christophe Van , De Sutter Johan , Peersman Wim , Calders Patrick
Published: July 2009

Background

The oxygen uptake efficiency slope (OUES) is a newer ventilatory exercise parameter, used in the evaluation of healthy participants and patients with cardiovascular disease. However, few data about the reliability and reproducibility of OUES are available. Our study assessed intratest reliability and test-retest reproducibility of OUES in healthy participants.

Design and methods

Eighteen participants (age 28 ± 6 years, BMI 22.1 ± 1.9 kg/m2, 10 men) performed two identical maximal exercise tests on a bicycle ergometer. To assess test-retest reproducibility, we performed Bland-Altman analysis and calculated the coefficient of repeatability of the main ventilatory variables.

Results

OUES remained stable during the second part of the exercise test. Mean values varied 2.4 ± 4.0% between OUES calculated at 70% (OUES70) and at 100% of exercise duration. Mean variation decreased to 1.4 ± 2.3% when OUES was calculated at 90% of exercise duration (OUES90). The Bland-Altman 95% limits of agreement for OUES90 were +3 and –6%, those for OUES70 were +11 and –8%. The coefficient of repeatability for OUES was 597 ml/min or 18.7% of the average value of repeated OUES measurements. These results were similar to those of peak oxygen uptake and minute ventilation/carbon dioxide output. However, the test-retest reproducibility for submaximal-derived values of OUES was lower, as we noted higher coefficients of repeatability for OUES90 and OUES70, increasing up to 27% of the average of repeated values.

Conclusion

OUES shows excellent intratest reliability and has a test-retest reproducibility that is similar to that of peak oxygen uptake and minute ventilation/carbon dioxide output slope. However, its reproducibility becomes higher when it is calculated from increasing levels of achieved exercise intensity.
Characteristics of Bacteroides fragilis lacking the major outer membrane protein, OmpA
Authors: Wexler Hannah M. , Tenorio Elizabeth , Pumbwe Lilian
Published: July 2009

OmpA1 is the major outer membrane protein of the Gram-negative anaerobic pathogenBacteroides fragilis. We identified three additional conservedompAhomologues (ompA2–ompA4) and three less homologousompA-like genes (ompAs5,6and7) inB. fragilis. We constructed anompA1disruption mutant inB. fragilis638R (WAL6 ΩompA1) using insertion-mediated mutagenesis. WAL6 ΩompA1formed much smaller colonies and had smaller, rounder forms on Gram stain analysis than the parental strain or other unrelated disruption mutants. SDS-PAGE and Western blot analysis (with anti-OmpA1 IgY) of the OMP patterns of WAL6 ΩompA1grown in both high- and low-salt media did not reveal any other OmpA proteins even under osmotic stress. AnompA1deletant (WAL186ΔompA1) was constructed using a two-step double-crossover technique, and anompA‘reinsertant’, WAL360+ompA1, was constructed by reinserting theompAgene into WAL186ΔompA1. WAL186ΔompA1was significantly more sensitive to exposure to SDS, high salt and oxygen than the parental (WAL108) or reinsertant (WAL360+ompA1) strain. No significant change was seen in MICs of a variety of antimicrobials for either WAL6 ΩompA1or WAL186ΔompA1compared to WAL108. RT-PCR revealed that all of theompAgenes are transcribed in the parental strain and in the disruption mutant, but, as expected,ompA1is not transcribed in WAL186ΔompA1. Unexpectedly,ompA4is also not transcribed in WAL186ΔompA1. A predicted structure indicated that among the four OmpA homologues, the barrel portion is more conserved than the loops, except for specific conserved patches on loop 1 and loop 3. The presence of multiple copies of such similar genes in one organism would suggest a critical role for this protein inB. fragilis.
Genomic DNA microarray comparison of gene expression patterns in Paracoccidioides brasiliensis mycelia and yeasts in vitro
Authors: Monteiro Jomar Patrício , Clemons Karl V. , Mirels Laurence F. , Coller John A. , Wu Thomas D. , Shankar Jata , Lopes Catalina R. , Stevens David A.
Published: July 2009

Paracoccidioides brasiliensis is a thermally dimorphic fungus, and causes the most prevalent systemic mycosis in Latin America. Infection is initiated by inhalation of conidia or mycelial fragments by the host, followed by further differentiation into the yeast form. Information regarding gene expression by either form has rarely been addressed with respect to multiple time points of growth in culture. Here, we report on the construction of a genomic DNA microarray, covering approximately 25 % of the genome of the organism, and its utilization in identifying genes and gene expression patterns during growth in vitro. Cloned, amplified inserts from randomly sheared genomic DNA (gDNA) and known control genes were printed onto glass slides to generate a microarray of over 12 000 elements. To examine gene expression, mRNA was extracted and amplified from mycelial or yeast cultures grown in semi-defined medium for 5, 8 and 14 days. Principal components analysis and hierarchical clustering indicated that yeast gene expression profiles differed greatly from those of mycelia, especially at earlier time points, and that mycelial gene expression changed less than gene expression in yeasts over time. Genes upregulated in yeasts were found to encode proteins shown to be involved in methionine/cysteine metabolism, respiratory and metabolic processes (of sugars, amino acids, proteins and lipids), transporters (small peptides, sugars, ions and toxins), regulatory proteins and transcription factors. Mycelial genes involved in processes such as cell division, protein catabolism, nucleotide biosynthesis and toxin and sugar transport showed differential expression. Sequenced clones were compared with Histoplasma capsulatum and Coccidioides posadasii genome sequences to assess potentially common pathways across species, such as sulfur and lipid metabolism, amino acid transporters, transcription factors and genes possibly related to virulence. We also analysed gene expression with time in culture and found that while transposable elements and components of respiratory pathways tended to increase in expression with time, genes encoding ribosomal structural proteins and protein catabolism tended to sharply decrease in expression over time, particularly in yeast. These findings expand our knowledge of the different morphological forms of P. brasiliensis during growth in culture.
ACCase 6 is the essential acetyl-CoA carboxylase involved in fatty acid and mycolic acid biosynthesis in mycobacteria
Authors: Kurth Daniel G. , Gago Gabriela M. , de la Iglesia Agustina , Bazet Lyonnet Bernardo , Lin Ting-Wan , Morbidoni Héctor R. , Tsai Shiou-Chuan , Gramajo Hugo
Published: July 2009

Mycolic acids are essential for the survival, virulence and antibiotic resistance of the human pathogenMycobacterium tuberculosis. Inhibitors of mycolic acid biosynthesis, such as isoniazid and ethionamide, have been used as efficient drugs for the treatment of tuberculosis. However, the increase in cases of multidrug-resistant tuberculosis has prompted a search for new targets and agents that could also affect synthesis of mycolic acids. In mycobacteria, the acyl-CoA carboxylases (ACCases) provide the building blocks forde novofatty acid biosynthesis by fatty acid synthase (FAS) I and for the elongation of FAS I products by the FAS II complex to produce meromycolic acids. By generating a conditional mutant in theaccD6gene ofMycobacterium smegmatis,we demonstrated that AccD6 is the essential carboxyltransferase component of the ACCase 6 enzyme complex implicated in the biosynthesis of malonyl-CoA, the substrate of the two FAS enzymes ofMycobacteriumspecies. Based on the conserved structure of the AccD5 and AccD6 active sites we screened several inhibitors of AccD5 as potential inhibitors of AccD6 and found that the ligand NCI-172033 was capable of inhibiting AccD6 with an IC50of 8 μM. The compound showed bactericidal activity against several pathogenicMycobacteriumspecies by producing a strong inhibition of both fatty acid and mycolic acid biosynthesis at minimal inhibitory concentrations. Overexpression ofaccD6inM. smegmatisconferred resistance to NCI-172033, confirming AccD6 as the main target of the inhibitor. These results define the biological role of a key ACCase in the biosynthesis of membrane and cell envelope fatty acids, and provide a new target, AccD6, for rational development of novel anti-mycobacterial drugs.
Physiological and biochemical characterization of the two α-l-rhamnosidases of Lactobacillus plantarum NCC245
Authors: Ávila Marta , Jaquet Muriel , Moine Deborah , Requena Teresa , Peláez Carmen , Arigoni Fabrizio , Jankovic Ivana
Published: July 2009

This work is believed to be the first report on the physiological and biochemical characterization of α-l-rhamnosidases in lactic acid bacteria. A total of 216 strains representing 37 species and eight genera of food-grade bacteria were screened for α-l-rhamnosidase activity. The majority of positive bacteria (25 out of 35) were Lactobacillus plantarum strains, and activity of the L. plantarum strain NCC245 was examined in more detail. The analysis of α-l-rhamnosidase activity under different growth conditions revealed dual regulation of the enzyme activity, involving carbon catabolite repression and induction: the enzyme activity was downregulated by glucose and upregulated by l-rhamnose. The expression of the two α-l-rhamnosidase genes rhaB1 and rhaB2 and two predicted permease genes rhaP1 and rhaP2, identified in a probable operon rhaP2B2P1B1, was repressed by glucose and induced by l-rhamnose, showing regulation at the transcriptional level. The two α-l-rhamnosidase genes were overexpressed and purified from Escherichia coli. RhaB1 activity was maximal at 50 °C and at neutral pH and RhaB2 maximal activity was detected at 60 °C and at pH 5, with high residual activity at 70 °C. Both enzymes showed a preference for the α-1,6 linkage of l-rhamnose to β-d-glucose, hesperidin and rutin being their best substrates, but, surprisingly, no activity was detected towards the α-1,2 linkage in naringin under the tested conditions. In conclusion, we identified and characterized the strain L. plantarum NCC245 and its two α-l-rhamnosidase enzymes, which might be applied for improvement of bioavailability of health-beneficial polyphenols, such as hesperidin, in humans.
OmpR positively regulates urease expression to enhance acid survival of Yersinia pseudotuberculosis
Authors: Hu Yangbo , Lu Pei , Wang Yao , Ding Lisha , Atkinson Steve , Chen Shiyun
Published: July 2009

Yersinia pseudotuberculosis is an enteric bacterium which must overcome the acidic stress in host organs for successful colonization, but how this bacterium survives in acidic conditions remains largely unknown. In the present study, the importance of OmpR in acid survival of Y. pseudotuberculosis YpIII was confirmed by the fact that mutation of ompR (strain ΔompR) greatly reduced cell survival at pH 4.5 or lower. To characterize the regulatory role of OmpR in this acid survival process, proteomic analysis was carried out to compare YpIII at pH 7.0 and pH 4.5 with ΔompR at pH 7.0, and urease components were revealed to be the main targets for OmpR regulation. Addition of urea to the culture medium also enhanced acid survival of YpIII but not ΔompR and urease activity was significantly induced by acid in YpIII but not in ΔompR. Each of the seven components of the YpIII urease gene cluster was fused to a lacZ reporter and their expression was dramatically decreased in a ΔompR background; this supports the notion that OmpR positively regulates urease expression. Furthermore, gel shift analysis revealed that OmpR binds to the deduced promoter regions of three polycistronic transcriptional units (ureABC, ureEF and ureGD) in the urease cluster, suggesting that the regulation of OmpR to urease components is direct. Taken together, these data strongly suggest that OmpR activates urease expression to enhance acid survival in Y. pseudotuberculosis.
Pseudomonas aeruginosa las and rhl quorum-sensing systems are important for infection and inflammation in a rat prostatitis model
Authors: Nelson Lisa K. , D'Amours Genevieve H. , Sproule-Willoughby Kimberley M. , Morck Douglas W. , Ceri Howard
Published: July 2009

Pseudomonas aeruginosa frequently acts as an opportunistic pathogen of mucosal surfaces; yet, despite causing aggressive prostatitis in some men, its role as a pathogen in the prostate has not been investigated. Consequently, we developed a Ps. aeruginosa infection model in the rat prostate by instilling wild-type (WT) Ps. aeruginosa strain PAO1 into the rat prostate. It was found that Ps. aeruginosa produced acute and chronic infections in this mucosal tissue as determined by bacterial colonization, gross morphology, tissue damage and inflammatory markers. WT strain PAO1 and its isogenic mutant PAO-JP2, in which both the lasI and rhlI quorum-sensing signal systems have been silenced, were compared during both acute and chronic prostate infections. In acute infections, bacterial numbers and inflammatory markers were comparable between WT PA01 and PAO-JP2; however, considerably less tissue damage occurred in infections with PAO-JP2. Chronic infections with PAO-JP2 resulted in reduced bacterial colonization, tissue damage and inflammation as compared to WT PAO1 infections. Therefore, the quorum-sensing lasI and rhlI genes in Ps. aeruginosa affect acute prostate infections, but play a considerably more important role in maintaining chronic infections. We have thus developed a highly reproducible model for the study of Ps. aeruginosa virulence in the prostate.
Growth of calcium-blind mutants of Yersinia pestis at 37 °C in permissive Ca2+-deficient environments
Authors: Fowler Janet M. , Wulff Christine R. , Straley Susan C. , Brubaker Robert R.
Published: July 2009

Cells of wild-typeYersinia pestisexhibit a low-calcium response (LCR) defined as bacteriostasis with expression of a pCD-encoded type III secretion system (T3SS) during cultivation at 37 °C without added Ca2+versus vegetative growth with downregulation of the T3SS with Ca2+(≥2.5 mM). Bacteriostasis is known to reflect cumulative toxicity of Na+,l-glutamic acid and culture pH; control of these variables enables full-scale growth (‘rescue’) in the absence of Ca2+. Several T3SS regulatory proteins modulate the LCR, because their absence promotes a Ca2+-blind phenotype in which growth at 37 °C ceases and the T3SS is constitutive even with added Ca2+. This study analysed the connection between the LCR and Ca2+by determining the response of selected Ca2+-blind mutants grown in Ca2+-deficient rescue media containing Na+plusl-glutamate (pH 5.5), where the T3SS is not expressed,l-glutamate alone (pH 6.5), wherel-aspartate is fully catabolized, and Na+alone (pH 9.0), where the electrogenic sodium pump NADH : ubiquinone oxidoreductase becomes activated. All three conditions supported essentially full-scale Ca2+-independent growth at 37 °C of wild-typeY. pestisas well aslcrGandyopNmutants (possessing a complete but dysregulated T3SS), indicating that bacteriostasis reflects a Na+-dependent lesion in bioenergetics. In contrast, mutants lacking the negative regulator YopD or the YopD chaperone (LcrH) failed to grow in any rescue medium and are therefore truly temperature-sensitive. The Ca2+-blindyopDphenotype was fully suppressed in a Ca2+-independent background lacking the injectisome-associated inner-membrane component YscV but not peripheral YscK, suggesting that the core translocon energizes YopD.
3-Chlorobenzoate is taken up by a chromosomally encoded transport system in Cupriavidus necator JMP134
Authors: Ledger T. , Aceituno F. , González B.
Published: July 2009

Cupriavidus necator JMP134(pJP4) is able to grow on 3-chlorobenzoate (3-CB), a model chloroaromatic pollutant. Catabolism of 3-CB is achieved via the expression of the chromosomally encoded benABCD genes and the tfd genes from plasmid pJP4. Since passive diffusion of benzoic acid derivatives at physiological pH is negligible, the uptake of this compound should be facilitated by a transport system. However, no transporter has so far been described to perform this function, and identification of chloroaromatic compound transporters has been limited. In this work, uptake experiments using 3-[ring-UL-14C]CB showed an inducible transport system in strain JMP134, whose expression is activated by 3-CB and benzoate. A similar level of 3-CB uptake was found for a mutant strain of JMP134, defective in chlorobenzoate degradation, indicating that metabolic drag is not an important component of the measured uptake rate. Competitive inhibitor assays showed that uptake of 3-CB was inhibited by benzoate and, to a lesser degree, by 3-CB and 3,5-dichlorobenzoate, but not by any of 12 other substituted benzoates tested. The expression of several gene candidates for this transport function was analysed by RT-PCR, including both permease-type and ABC-type ATP-dependent transporters. Induction of a chromosomally encoded putative permease transporter (benP gene) was found specifically in the presence of 3-CB or benzoate. A benP knockout mutant of strain JMP134 displayed an almost complete loss of 3-CB transport activity. This is to our knowledge the first report of a 3-CB transporter.
Novel role of the nitrite transporter NirC in Salmonella pathogenesis: SPI2-dependent suppression of inducible nitric oxide synthase in activated macrophages
Authors: Das Priyanka , Lahiri Amit , Lahiri Ayan , Chakravortty Dipshikha
Published: July 2009

Activation of macrophages by interferon gamma (IFN-γ) and the subsequent production of nitric oxide (NO) are critical for the host defence againstSalmonella entericaserovar Typhimurium infection. We report here the inhibition of IFN-γ-induced NO production in RAW264.7 macrophages infected with wild-typeSalmonella. This phenomenon was shown to be dependent on thenirCgene, which encodes a potential nitrite transporter. We observed a higher NO output from IFN-γ-treated macrophages infected with anirCmutant ofSalmonella. ThenirCmutant also showed significantly decreased intracellular proliferation in a NO-dependent manner in activated RAW264.7 macrophages and in liver, spleen and secondary lymph nodes of mice, which was restored by complementing the genein trans. Under acidified nitrite stress, a twofold more pronounced NO-mediated repression of SPI2 was observed in thenirCknockout strain compared to the wild-type. This enhanced SPI2 repression in thenirCknockout led to a higher level of STAT-1 phosphorylation and inducible nitric oxide synthase (iNOS) expression than seen with the wild-type strain. In iNOS knockout mice, the organ load of thenirCknockout strain was similar to that of the wild-type strain, indicating that the mutant is exclusively sensitive to the host nitrosative stress. Taken together, these results reveal that intracellularSalmonellaevade killing in activated macrophages by downregulating IFN-γ-induced NO production, and they highlight the critical role ofnirCas a virulence gene.
The role of FIS in the Rcd checkpoint and stable maintenance of plasmid ColE1
Authors: Blaby I. K. , Summers D. K.
Published: July 2009

Escherichia coli plasmid ColE1 lacks active partitioning, and copies are distributed randomly to daughter cells at division. The plasmid is maintained stably in the bacterial population as long as its copy number remains high. The accumulation of plasmid dimers and higher multimers depresses copy number, and is an important cause of multicopy plasmid instability. ColE1 dimers are restored to the monomeric state by site-specific recombination, which requires the host-encoded proteins XerCD, ArgR and PepA acting at the plasmid cer site. In addition, a 70 nt RNA expressed from the cer site of plasmid dimers delays the division of dimer-containing cells. Here, we report that the global regulator FIS binds to cer in a sequence-specific manner, close to the Rcd promoter (P
cer
). FIS is not required for plasmid dimer resolution, but is essential for repression of P
cer
in plasmid monomers. Repression also requires the XerCD recombinase, but not ArgR or PepA. We propose a model for monomer–dimer control of P
cer
in which the promoter is repressed in plasmid monomers by the concerted action of FIS and XerCD. Rcd transcription is triggered in plasmid dimers by the lifting of XerCD-mediated repression in the synaptic complex.
Identification of conserved antigens for early serodiagnosis of relapsing fever Borrelia
Authors: Lopez Job E. , Porcella Stephen F. , Schrumpf Merry E. , Raffel Sandra J. , Hammer Carl H. , Zhao Ming , Robinson Mary Ann , Schwan Tom G.
Published: July 2009

Borrelia hermsiiis a blood-borne pathogen transmitted by the argasid tickOrnithodoros hermsi. Since spirochaete clearance in mice is associated with an IgM-mediated response, an immunoproteomic analysis was used to identify proteins reactive with IgM. We report that IgM from both mice and human patients infected withB. hermsiinot only reacted with the previously identified variable membrane proteins but also identified candidate antigens including heat-shock proteins, an adhesin protein, ABC transporter proteins, flagellar proteins, housekeeping proteins, an immune evasion protein, and proteins with unknown function. Furthermore, IgM reactivity to recombinant glycerophosphodiester phosphodiesterase was detected during early spirochaete infection and prior to a detectable IgG response. Lastly, a conserved hypothetical protein was produced inEscherichia coliand tested with immune serum againstB. hermsiiandBorrelia recurrentis. These results identify a much larger set of immunoreactive proteins, and could help in the early serodiagnosis of this tick-borne infection.
The interaction between Listeria monocytogenes and the host gastrointestinal tract
Authors: Sleator Roy D. , Watson Debbie , Hill Colin , Gahan Cormac G. M.
Published: July 2009

Listeria monocytogenesis a ubiquitous bacterium that causes significant foodborne disease with high mortality rates in immunocompromised adults. In pregnant women foodborne infection can give rise to infection of the fetus resulting in miscarriage. In addition, the bacterium has recently been demonstrated to cause localized gastrointestinal symptoms, predominantly in immunocompetent individuals. The murine model of systemicL. monocytogenesinfection has provided numerous insights into the mechanisms of pathogenesis of this organism. However, recent application of transcriptomic and proteomic approaches as well as the development of new model systems has allowed a focus upon factors that influence adaptation to gastrointestinal environments and adhesion to and invasion of the gastrointestinal mucosa. In addition, the availability of a large number of completeL. monocytogenesgenome sequences has permitted inter-strain comparisons and the identification of factors that may influence the emergence of ‘epidemic’ phenotypes. Here we review some of the exciting recent developments in the analysis of the interaction betweenL. monocytogenesand the host gastrointestinal tract.
Caught at its own game: regulatory small RNA inactivated by an inducible transcript mimicking its target
Authors: Figueroa-Bossi Nara , Valentini Martina , Malleret Laurette , Bossi Lionello
Published: July 2009

A relevant, yet little recognized feature of antisense regulation is the possibility of switching roles between regulatory and regulated RNAs. Here we show that induction of aSalmonellagene relies on the conversion of a small RNA from effector to regulatory target. ThechiPgene (formerlyybfM), identified and characterized in the present study, encodes a conserved enterobacterial chitoporin required for uptake of chitin-derived oligosaccharides. In the absence of inducer,chiPis kept silent by the action of a constitutively made small RNA, ChiX (formerly SroB, RybC), which pairs with a sequence at the 5′ end ofchiPmRNA. Silencing is relieved in the presence of chitooligosaccharides due to the accumulation of an RNA that pairs with ChiX and promotes its degradation. Anti-ChiX RNA originates from an intercistronic region of thechboperon, which comprises genes for chitooligosaccharide metabolism and whose transcription is activated in the presence of these sugars. We present evidence suggesting that thechbRNA destabilizes ChiX sRNA by invading the stem of its transcription terminator hairpin. Overall, our findings blur the distinction between effector and target in sRNA regulation, raising the possibility that some of the currently defined targets could actually be inhibitors of sRNA function.
Microarray-based multicycle-enrichment of genomic subsets for targeted next-generation sequencing
Authors: Summerer Daniel , Wu Haiguo , Haase Bettina , Cheng Yang , Schracke Nadine , Stähler Cord F. , Chee Mark S. , Stähler Peer F. , Beier Markus
Published: July 2009

The lack of efficient high-throughput methods for enrichment of specific sequences from genomic DNA represents a key bottleneck in exploiting the enormous potential of next-generation sequencers. Such methods would allow for a systematic and targeted analysis of relevant genomic regions. Recent studies reported sequence enrichment using a hybridization step to specific DNA capture probes as a possible solution to the problem. However, so far no method has provided sufficient depths of coverage for reliable base calling over the entire target regions. We report a strategy to multiply the enrichment performance and consequently improve depth and breadth of coverage for desired target sequences by applying two iterative cycles of hybridization with microfluidic Geniom biochips. Using this strategy, we enriched and then sequenced the cancer-related genes BRCA1 and TP53 and a set of 1000 individual dbSNP regions of 500 bp using Illumina technology. We achieved overall enrichment factors of up to 1062-fold and average coverage depths of 470-fold. Combined with high coverage uniformity, this resulted in nearly complete consensus coverages with >86% of target region covered at 20-fold or higher. Analysis of SNP calling accuracies after enrichment revealed excellent concordance, with the reference sequence closely mirroring the previously reported performance of Illumina sequencing conducted without sequence enrichment.
Activation of metabotropic glutamate receptor type 2/3 supports the involvement of the hippocampal mossy fiber pathway on contextual fear memory consolidation
Authors: Daumas Stéphanie , Ceccom Johnatan , Halley Hélène , Francés Bernard , Lassalle Jean-Michel
Published: July 2009

Elucidating the functional properties of the dentate gyrus (DG), CA3, and CA1 areas is critical for understanding the role of the dorsal hippocampus in contextual fear memory processing. In order to specifically disrupt various hippocampal inputs, we used region-specific infusions of DCG-IV, the metabotropic glutamate receptor agonist, which selectively disrupts entorhinal outputs as well as mossy fiber transmission in the hippocampus. The consequences of these injections were studied using a contextual fear conditioning (CFC) paradigm. Selective contextual memory impairment was observed in DG- and CA3-, but not in CA1-treated mice. Our results emphasize the major role played by the DG and CA3 areas in the early phases of contextual memory processing, particularly during the acquisition and early consolidation phases of CFC.
The High Light Response inArabidopsisInvolves ABA Signaling between Vascular and Bundle Sheath Cells
Authors: Galvez-Valdivieso Gregorio , Fryer Michael J. , Lawson Tracy , Slattery Katie , Truman William , Smirnoff Nicholas , Asami Tadao , Davies William J. , Jones Alan M. , Baker Neil R. , Mullineaux Philip M.
Published: July 2009

Previously, it has been shown that Arabidopsis thaliana leaves exposed to high light accumulate hydrogen peroxide (H2O2) in bundle sheath cell (BSC) chloroplasts as part of a retrograde signaling network that induces ASCORBATE PEROXIDASE2 (APX2). Abscisic acid (ABA) signaling has been postulated to be involved in this network. To investigate the proposed role of ABA, a combination of physiological, pharmacological, bioinformatic, and molecular genetic approaches was used. ABA biosynthesis is initiated in vascular parenchyma and activates a signaling network in neighboring BSCs. This signaling network includes the Gα subunit of the heterotrimeric G protein complex, the OPEN STOMATA1 protein kinase, and extracellular H2O2, which together coordinate with a redox-retrograde signal from BSC chloroplasts to activate APX2 expression. High light–responsive genes expressed in other leaf tissues are subject to a coordination of chloroplast retrograde signaling and transcellular signaling activated by ABA synthesized in vascular cells. ABA is necessary for the successful adjustment of the leaf to repeated episodes of high light. This process involves maintenance of photochemical quenching, which is required for dissipation of excess excitation energy.
ArabidopsisDUO POLLEN3 Is a Key Regulator of Male Germline Development and Embryogenesis
Authors: Brownfield Lynette , Hafidh Said , Durbarry Anjusha , Khatab Hoda , Sidorova Anna , Doerner Peter , Twell David
Published: July 2009

Male germline development in angiosperms produces the pair of sperm cells required for double fertilization. A key regulator of this process in Arabidopsis thaliana is the male germline-specific transcription factor DUO POLLEN1 (DUO1) that coordinates germ cell division and gamete specification. Here, we uncover the role of DUO3, a nuclear protein that has a distinct, but overlapping role with DUO1 in male germline development. DUO3 is a conserved protein in land plants and is related to GON-4, a cell lineage regulator of gonadogenesis in Caenorhabditis elegans. Mutant duo3-1 germ cells either fail to divide or show a delay in division, and we show that, unlike DUO1, DUO3 promotes entry into mitosis independent of the G2/M regulator CYCB1;1. We also show that DUO3 is required for the expression of a subset of germline genes under DUO1 control and that like DUO1, DUO3 is essential for sperm cell specification and fertilization. Furthermore, we demonstrate an essential sporophytic role for DUO3 in cell division and embryo patterning. Our findings demonstrate essential developmental roles for DUO3 in cell cycle progression and cell specification in both gametophytic and sporophytic tissues.
A formula for maximum possible steps in multistate characters: isolating matrix parameter effects on measures of evolutionary convergence
Authors: Cuthill Jennifer F. Hoyal , Braddy Simon J. , Donoghue Philip C. J.
Published: July 2009

To identify a biological signal in the distribution of homoplasy, it is first necessary to isolate non‐biological factors affecting its measurement. The number of states per character in a phylogenetic data matrix may indicate evolutionary flexibility and, consequently, the likelihood of recurrent evolution. However, we show here that the number of states per character limits the maximum number of steps that may be inferred using parsimony. A formula is provided for the maximum number of steps that may be taken by a character with a given number of states and taxa. We show that as more character states are included the maximum proportion of steps that can be attributed to homoplasy falls, and the greatest amount of homoplasy measurable with the consistency index declines.

© The Willi Hennig Society 2009.
Upper gastrointestinal findings and detection of Helicobacter pylori in patients with oral lichen planus
Authors: Attia E. A. S. , Abdel Fattah N. S. A. , Abdella H. M.
Published: July 2009

Background. Lichen planus (LP) is a mucocutaneous disease of unknown aetiology, which may involve the gastrointestinal (GI) mucosa. The association of Helicobacter pylori with LP has been a subject of debate.

Aim. To investigate upper GI findings and the presence of H. pylori in GI mucosa and oral LP (OLP).

Methods. Oral biopsies from 20 patients with erosive OLP and 20 with non-erosive OLP were investigated for the presence of H. pylori by histopathological examination and PCR. Upper GI endoscopy and GI mucosal biopsies were examined for LP lesions and/or H. pylori.

Results. The endoscopic findings of both groups were oesophagitis, antral gastritis and duodenitis. No LP or LP-like changes were found in the upper GI mucosa. H. pylori was found by histopathological examination in the gastric mucosa of 18 patients (45%), with equal distribution in both the control and study groups. Positive PCR results were obtained from biopsy specimens of oral lesions in all patients with erosive OLP and presence of H. pylori in the stomach (9 patients), but in none of the patients with non-erosive OLP (P = 0.001).

Conclusion. We did not find any difference in symptoms, endoscopic findings and histopathological results between patients with erosive and non-erosive OLP. However, the concomitant presence of erosive OLP, of H. pylori nucleic acid in erosive OLP and the H. pylori organisms in gastric mucosa implies a possible pathogenic connection between this bacterium and erosive OLP.
Cutaneous annular sarcoidosis developing on a background of exogenous ochronosis: a report of two cases and review of the literature
Authors: Moche M. J. , Glassman S. J. , Modi D. , Grayson W.
Published: July 2009

Exogenous (cosmetic) ochronosis is caused by the long term use of skin-lightening creams containing hydroquinone. Three cases of systemic sarcoidosis with cutaneous sarcoidal granulomas, which developed on ochronotic skin were last described by Jacyk in 1995. Dogliotti and Leibowitz previously reported cases of granulomatous ochronosis with sarcoid-like histological changes but with no associated systemic sarcoidosis. We report two additional cases of cutaneous sarcoidal granulomas, which developed on a background of cosmetic ochronosis in patients recently diagnosed with systemic sarcoidosis.
Grass invasion of a hardwood forest is associated with declines in belowground carbon pools
Authors: STRICKLAND MICHAEL S. , DEVORE JAYNA L. , MAERZ JOHN C. , BRADFORD MARK A.
Published: July 2009

Invasive plant species affect a range of ecosystem processes but their impact on belowground carbon (C) pools is relatively unexplored. This is particularly true for grass invasions of forested ecosystems. Such invasions may alter both the quantity and quality of forest floor inputs. Dependent on both, two theories, ‘priming’ and ‘preferential substrate utilization’, suggest these changes may decrease, increase, or leave unchanged native plant‐derived soil C. Decreases are expected under ‘priming’ theory due to increased soil microbial activity. Under ‘preferential substrate utilization’, either an increase or no change is expected because the invasive plant's inputs are used by the microbial community instead of soil C. Here, we examine how Microstegium vimineum affects belowground C‐cycling in a southeastern US forest. Following predictions of priming theory, M. vimineum's presence is associated with decreases in native‐derived, C pools. For example, in September 2006 M. vimineum is associated with 24%, 34%, 36%, and 72% declines in total organic, particulate organic matter, mineralizable (a measure of microbially‐available C), and microbial biomass C, respectively. Soil C derived from M. vimineum does not compensate for these decreases, meaning that the sum of native‐ plus invasive‐derived C pools is smaller than native‐derived pools in uninvaded plots. Supporting our inferences that C‐cycling accelerates under invasion, the microbial community is more active per unit biomass: added 13C‐glucose is respired more rapidly in invaded plots. Our work suggests that this invader may accelerate C‐cycling in forest soils and deplete C stocks. The paucity of studies investigating impacts of grass invasion on C‐cycling in forests highlights the need to study further M. vimineum and other invasive grasses to assess their impacts on C sink strength and forest fertility.
Changing patterns of bleeding in patients with severe haemophilia A
Authors: STEPHENSEN D. , TAIT R. C. , BRODIE N. , COLLINS P. , CHEAL R. , KEELING D. , MELTON K. , DOLAN G. , HAYE H. , HAYMAN E. , WINTER M.
Published: July 2009

Summary.  Previous studies on the pattern of joint bleeding in patients with haemophilia have reported that the knee joint is most frequently affected. Home treatment data reporting bleeding frequency and location collected from 100 patients registered at six haemophilia centres in the UK have been analysed to determine current patterns of bleeding. Bleeding frequency has markedly decreased although bleeding into joints remains the main characteristic of haemophilia. However, the ankle joint has replaced the knee joint as the most common joint affected. Furthermore, it seems that the frequency of knee joint bleeding is also less than the elbow joint suggesting that the traditional pattern of joint bleeding in haemophilia has now changed significantly.