bluuebunny/crossref_metadata_2025_split huggingface dataset:
Linkages between bacterioplankton community composition, heterotrophic carbon cycling and environmental conditions in a highly dynamic coastal ecosystem
Authors: Teira Eva , Gasol Josep M. , Aranguren‐Gassis María , Fernández Ana , González Jose , Lekunberri Itziar , Álvarez‐Salgado X. Antón 
Published: March 2008

SummaryWe used mesocosm experiments to study the bacterioplankton community in a highly dynamic coastal ecosystem during four contrasting periods of the seasonal cycle: winter mixing, spring phytoplankton bloom, summer stratification and autumn upwelling. A correlation approach was used in order to measure the degree of coupling between the dynamics of major bacterial groups, heterotrophic carbon cycling and environmental factors. We used catalysed reporter deposition‐fluorescencein situhybridization to follow changes in the relative abundance of the most abundant groups of bacteria (Alphaproteobacteria, Gammaproteobacteria and Bacteroidetes). Bacterial carbon flux‐related variables included bacterial standing stock, bacterial production and microbial respiration. The environmental factors included both, biotic variables such as chlorophyll‐a concentration, primary production, phytoplankton extracellular release, and abiotic variables such as the concentration of dissolved inorganic and organic nutrients. Rapid shifts in the dominant bacterial groups occurred associated to environmental changes and bacterial bulk functions. An alternation between Alphaproteobacteria and Bacteroidetes was observed associated to different phytoplankton growth phases. The dominance of the group Bacteroidetes was related to high bacterial biomass and production. We found a significant, non‐spurious, linkage between the relative abundances of major bacterial groups and bacterial carbon cycling. Our results suggest that bacteria belonging to these major groups could actually share a function in planktonic ecosystems.
Elevated atmospheric CO2 affects soil microbial diversity associated with trembling aspen
Authors: Lesaulnier Celine , Papamichail Dimitris , McCorkle Sean , Ollivier Bernard , Skiena Steven , Taghavi Safiyh , Zak Donald , Van Der Lelie Daniel 
Published: March 2008

SummaryThe effects of elevated atmospheric CO2 (560 p.p.m.) and subsequent plant responses on the soil microbial community composition associated with trembling aspen was assessed through the classification of 6996 complete ribosomal DNA sequences amplified from the Rhinelander WI free‐air CO2 and O3 enrichment (FACE) experiments microbial community metagenome. This in‐depth comparative analysis provides an unprecedented, detailed and deep branching profile of population changes incurred as a response to this environmental perturbation. Total bacterial and eukaryotic abundance does not change; however, an increase in heterotrophic decomposers and ectomycorrhizal fungi is observed. Nitrate reducers of the domain bacteria and archaea, of the phylum Crenarchaea, potentially implicated in ammonium oxidation, significantly decreased with elevated CO2. These changes in soil biota are evidence for altered interactions between trembling aspen and the microorganisms in its surrounding soil, and support the theory that greater plant detritus production under elevated CO2 significantly alters soil microbial community composition.
Diversity and mode of transmission of ammonia‐oxidizing archaea in marine sponges
Authors: Steger Doris , Ettinger‐Epstein Piers , Whalan Stephen , Hentschel Ute , De Nys Rocky , Wagner Michael , Taylor Michael W. 
Published: March 2008

SummaryThe model marine crenarchaeote ‘Cenarchaeum symbiosum’ is until now the only ammonia‐oxidizing archaeon known from a marine sponge. Here, phylogenetic analyses based on the 16S rRNA and ammonia monooxygenase subunit A (amoA) genes revealed the presence of putative ammonia‐oxidizing archaea (AOA) in a diverse range of sponges from the western Pacific, Caribbean and Mediterranean. amoA diversity was limited even between different oceans, with many of the obtained sequences (75.9%; ntotal = 83) forming a monophyletic, apparently sponge‐ (and coral‐) specific lineage, analogous to those previously inferred from comparative 16S rRNA gene studies of sponge‐associated microbes. The presence of AOA in sponge larvae, as detected by 16S rRNA and amoA PCR assays as well as by fluorescence in situ hybridization, suggests they are vertically transmitted and thus might be of importance for ammonia detoxification within the sponge.
Retrieval of entire genes from environmental DNA by inverse PCR with pre‐amplification of target genes using primers containing locked nucleic acids
Authors: Yamada Kazutaka , Terahara Takeshi , Kurata Shinya , Yokomaku Toyokazu , Tsuneda Satoshi , Harayama Shigeaki 
Published: March 2008

SummaryWe had been unsuccessful to amplify desired nucleotide sequences from various environmental DNA samples by using the inverse polymerase chain reaction (IPCR) technique, most probably because the copy numbers of target DNA sequences had been quite low. To enrich the target DNA sequences prior to IPCR, a rolling‐circle amplification was used with a site‐specific primer containing locked nucleic acids (LNAs). This pre‐amplified IPCR (PAI‐PCR) method increased the sensitivity of PCR almost 10 000 times compared with the standard IPCR in model experiments using Escherichia coli. We then applied the PAI‐PCR method to isolate glycosyl hydrolase genes from DNAs extracted from vermiform appendixes of horses and termite guts. The flanking sequences of the target genes were amplified and cloned successfully using PAI‐PCR, whereas standard IPCR resulted in no amplification.
An AbrB‐like protein might be involved in the regulation of cylindrospermopsin production by Aphanizomenon ovalisporum
Authors: Shalev‐Malul Gali , Lieman‐Hurwitz Judy , Viner‐Mozzini Yehudith , Sukenik Assaf , Gaathon Ariel , Lebendiker Mario , Kaplan Aaron 
Published: March 2008

SummaryCertain filamentous cyanobacteria, including Aphanizomenon ovalisporum, are potentially toxic owing to the formation of the hepatotoxin cylindrospermopsin. We previously identified a gene cluster in A. ovalisporum likely to be involved in cylindrospermopsin biosynthesis, including amidinotransferase (aoaA) and polyketide‐synthase (aoaC), transcribed on the reverse strands. Analysis of the genomic region between aoaA and aoaC identified two transcription start points for each of these genes, differentially expressed under nitrogen and light stress conditions. The transcript abundances of these genes and the cylindrospermopsin level were both affected by nitrogen availability and light intensity. Gel shift assays and DNA affinity columns isolated a protein that specifically binds to a 150 bp DNA fragment from the region between aoaA and aoaC, and MS/MS analyses identified similarity to AbrB in other cyanobacteria and in Bacillus sp. Comparison of the native AbrB isolated from A. ovalisporum with that obtained after cloning and overexpression of abrB in Escherichia coli identified specific post‐translational modifications in the native cyanobacterial protein. These modifications, which are missing in the protein expressed in E. coli, include N‐acetylation and methylation of specific residues. We discuss the possible role of these modifications in the regulation of cylindrospermopsin production in Aphanizomenon.
Evidence for a human‐specific Escherichia coli clone
Authors: Clermont Olivier , Lescat Mathilde , O'Brien Claire L. , Gordon David M. , Tenaillon Olivier , Denamur Erick 
Published: March 2008

Summary Escherichia coli is a widespread commensal of the vertebrate intestinal tract. Until recently, no strong association between a particular clone and a given host species has been found. However, members of the B2 subgroup VIII clone with an O81 serotype appear to be human host specific. To determine the degree of host specificity exhibited by this clone, a PCR‐based assay was used to screen 723 faecal and clinical isolates from humans, and 904 faecal isolates from animals. This clone was not detected among the animal isolates, but was discovered in people living in Africa, Europe and South America. The clone is rarely isolated from people suffering from intestinal or extraintestinal disease and is avirulent in a mouse model of extraintestinal infection. Fine‐scale epidemiological analysis suggests that this clone is competitively dominant relative to other members of the B2 phylogenetic group and that it has increased in frequency over the past 20 years. This clone appears to be a good candidate for use as a probiotic, and may be suitable as an indicator of human faecal contamination in microbial source tracking studies.
The influence of habitat heterogeneity on freshwater bacterial community composition and dynamics
Authors: Shade Ashley , Jones Stuart E. , McMahon Katherine D. 
Published: March 2008

SummaryMultiple forces structure natural microbial communities, but the relative roles and interactions of these drivers are poorly understood. Gradients of physical and chemical parameters can be especially influential. In traditional ecological theory, variability in environmental conditions across space and time represents habitat heterogeneity, which may shape communities. Here we used aquatic microbial communities as a model to investigate the relationship between habitat heterogeneity and community composition and dynamics. We defined spatial habitat heterogeneity as vertical temperature and dissolved oxygen (DO) gradients in the water column, and temporal habitat heterogeneity as variation throughout the open‐water season in these environmental parameters. Seasonal lake mixing events contribute to temporal habitat heterogeneity by destroying and re‐creating these gradients. Because of this, we selected three lakes along a range of annual mixing frequency (polymictic, dimictic, meromictic) for our study. We found that bacterial community composition (BCC) was distinct between the epilimnion and hypolimnion within stratified lakes, and also more variable within the epilimnia through time. We found stark differences in patterns of epilimnion and hypolimnion dynamics over time and across lakes, suggesting that specific drivers have distinct relative importance for each community.
Novel concepts in the diagnosis, pathophysiology and management of idiopathic megabowel
Authors: Gladman M. A. , Knowles C. H. 
Published: March 2008

AbstractA proportion of patients with intractable constipation have persistent dilatation of the bowel, which in the absence of an organic cause is termed idiopathic megabowel (IMB). Whilst uncommon, this condition results in considerable morbidity. Traditional methods of identifying such patients are associated with inherent methodological limitations with anorectal manometry and contrast studies overestimating and underestimating the prevalence of the condition, respectively. Recently, controlled, pressure‐based distension during fluoroscopic imaging has allowed more accurate identification of patients on the basis of a rectal diameter > 6.3 cm at the minimum distension pressure. Histopathological abnormalities of all three final effectors of sensorimotor function have been reported, although it remains unclear whether these changes are primary, secondary or epiphenomic. Physiological abnormalities of sensorimotor function, namely impaired perception of rectal distension and delayed colonic transit are well documented in patients with IMB. Further, the recent demonstration of two subgroups of patients, defined on the basis of rectal compliance, suggests the possibility that they differ pathophysiologically, although the clinical relevance of this distinction is uncertain. Surgery is performed when conservative therapy is ineffective or poorly tolerated. Numerous procedures have been attempted with variable success rates and significant mortality and morbidity. Surgery should preferably be performed in specialist centres given the relative infrequency with which such patients are encountered, and that they require comprehensive clinical, psychological and physiological evaluation preoperatively.
Disease stage and psychosocial outcomes in colorectal cancer
Authors: Simon A. E. , Thompson M. R. , Flashman K. , Wardle J. 
Published: March 2008

AbstractObjective  Disease stage is a strong predictor of cancer survival and is therefore assumed to influence psychosocial outcomes. However, existing findings are inconsistent, perhaps reflecting limited sample sizes, especially among patients with advanced disease. There has also been an emphasis on breast cancer, resulting in a focus on outcomes among women. The present study investigated associations between disease stage and psychosocial wellbeing in 128 patients (52% male, 48% female) diagnosed with colorectal cancer.Method  Patients diagnosed within the past year in a single hospital were invited to participate in a questionnaire study and give permission for staging information to be obtained from their medical records. The questionnaire included measures of anxiety, depression, quality of life, social support, social difficulties and quality of medical interactions.Results  Patients with more advanced disease were more anxious (P < 0.01) and depressed (P < 0.001), perceived their social support as lower (P < 0.01), and had a worse quality of life (P < 0.01). Women with advanced disease had more severe colorectal symptoms (P < 0.01), and worse physical (P < 0.01) and emotional (P < 0.05) quality of life than men.Conclusion  Patients with advanced colorectal cancer have unmet psychosocial needs. Women may be more strongly affected by advanced disease than men.
A cost‐effectiveness analysis of delayed sphincteroplasty for anal sphincter injury
Authors: Tan E. K. , Jacovides M. , Khullar V. , Teoh T.‐G. , Fernando R. J. , Tekkis P. P. 
Published: March 2008

AbstractObjective  Anal‐sphincter injury may result in faecal incontinence. Sphincteroplasty is usually performed as a primary (immediate) procedure. Delayed sphincteroplasty (DS) can be performed if there is significant trauma or soiling, if the primary procedure has failed, and if the injury was not recognized initially. This study aimed to determine the cost to patient and health service in the event a DS is performed.Method  Patients with anal‐sphincter‐injury who underwent primary sphincteroplasty (PS)/DS were identified from the published literature (primary, n = 103; delayed, n = 777) using Medline, Embase, Ovid and Cochrane databases for studies published between 1976 and 2006. Studies included described at least one of the measured outcomes – probability of functional success/failure and quality of life (QOL). An economic model was constructed and decision analysis performed using a decision tree based on a Markov process. Main outcomes were quality‐adjusted‐life‐years (QALYs) gained from each strategy, costs incurred and incremental cost‐effectiveness ratio (ICER) over a 10‐ and 15‐year time horizon.Results  Over 10 years, primary sphincteroplasty (PS) produced a gain of 5.72 QALYs for an estimated £2750, giving an ICER of £487 per QALY. DS produced a gain of 3.73 QALYs for a cost of £2667, giving an ICER of £719 per QALY. Both procedures fell below the £10 000 per QALY willingness‐to‐pay threshold, but PS produced the highest QALYs. Both procedures performed poorly beyond the 10‐year mark.Conclusion  If DS has to be performed, the resultant cost is greater with concurrently lower QALYs gained. Successful PS substantially improves QOL and reduces overall cost‐of‐treatment.
Metformin, but not pioglitazone, decreases postchallenge plasma ghrelin levels in type 2 diabetic patients: a possible role in weight stability?
Authors: Kusaka I. , Nagasaka S. , Horie H. , Ishibashi S. 
Published: March 2008

Aim:  Effects of metformin and pioglitazone on body weight are clearly different. Recently, the role of ghrelin, an orexigenic peptide derived from stomach, has been appreciated. Plasma ghrelin levels display a preprandial peak and postprandial suppression, suggesting its physiological role. We hypothesized that metformin or pioglitazone may modulate circulating ghrelin levels and this modulation may be related to differential effects on body weight with these agents.Methods:  Thirty‐five Japanese type 2 diabetic patients [21 men and 14 women, age 62 ± 2 years, body mass index (BMI) 26.6 ± 0.5 kg/m2 and haemoglobin A1c (HbA1c) 8.2 ± 0.1%, mean ± s.e.] were randomly assigned to groups for the addition of metformin or pioglitazone. At baseline and 4 months later, a 75‐g oral glucose tolerance test (OGTT) was performed to measure plasma ghrelin levels.Results:  In 33 subjects who completed the study, the overall decrease in HbA1c (∼1%) was comparable between the two groups. As expected, BMI increased in the pioglitazone group but not in the metformin group. After the treatment, plasma ghrelin levels at each point of OGTT remained unchanged in the pioglitazone group. In the metformin group, fasting ghrelin levels were unaltered, whereas the absolute levels at 30, 60 and 120 min decreased significantly. The area under the curve for the 2‐h ghrelin profile also decreased significantly.Conclusions:  Metformin, but not pioglitazone, decreased plasma ghrelin levels after the glucose load. This decrease may in part account for weight stability in type 2 diabetic patients treated with metformin.
Glimepiride as insulin sensitizer: increased liver and muscle responses to insulin
Authors: Mori R. C. T. , Hirabara S. M. , Hirata A. E. , Okamoto M. M. , Machado U. F. 
Published: March 2008

Aim:  Glimepiride, a low‐potency insulin secretagogue, is as efficient on glycaemic control as other sulphonylureas, suggesting an additional insulin‐sensitizer role. The aim of the present study was to confirm the insulin‐sensitizer role of glimepiride and to show extra‐pancreatic effects of the drug.Methods:  Three‐month‐old monosodium glutamate (MSG)–induced obese insulin‐resistant rats were treated (OG) or not treated (O) with glimepiride for 4 weeks and compared with age‐matched non‐obese rats (C). Insulin sensitivity in whole body, glucose transporter 4 (GLUT4) protein content, glucose uptake and glycogen synthesis in oxidative skeletal muscle and phospho‐glycogen synthase kinase (p‐GSK3) and glycogen content in liver were analysed.Results:  Insulin sensitivity, analysed by the insulin tolerance test, was 30% lower in O than in C rats (p < 0.05), and OG rats recovered this parameter (p < 0.05). In oxidative muscle, glimepiride increased the GLUT4 protein content (50%, p < 0.001) and recovered the obesity‐induced reduction (∼20%) of the in vitro insulin‐stimulated glucose uptake and incorporation into glycogen. In liver, glimepiride increased p‐GSK3 (p < 0.01) and glycogen (p < 0.05) contents.Conclusion:  The increased GLUT4 protein expression and glucose utilization in oxidative muscle and the increased insulin sensitivity and glycogen storage in liver evidence the insulin‐sensitizer effect of glimepiride, which must be important to enable the glimepiride drug to promote an efficient glycaemic control.
Fluctuation and reproducibility of exposure and effect of insulin glargine in healthy subjects*
Authors: Becker R. H. A. , Frick A. D. , Teichert L. , Nosek L. , Heinemann L. , Heise T. , Rave K. 
Published: March 2008

Aim:  Low diurnal fluctuation and high day‐to‐day reproducibility in exposure and effect characterize beneficial basal insulin products. Two insulin glargine (LANTUS) formulations [without (R) or with polysorbate‐20 (T)], added to minimize unfolding of proteins and subsequent formation of fibril structures, were assessed for equivalence in exposure and effect, and aspects of fluctuation and reproducibility in time–concentration and time–action profiles.Methods:  A dose of 0.4 U/kg was subcutaneously administered to 24 healthy subjects in a two‐sequence (R‐T‐R‐T or T‐R‐T‐R), randomized, four‐way crossover trial utilizing 30‐h Biostator‐based euglycaemic glucose clamps.Results:  Identical serum insulin glargine concentration and time–action profiles established average, individual and population equivalence in insulin exposure and effect. Point estimates for 24‐h area under the curve for insulin (INS–AUC0–24 h) and glucose infusion rates (GIR–AUC0–24 h) were 97% [90% confidence interval (CI): 91–103%] and 100% (88–114%), respectively. Within‐subject variability (coefficient of variation) for INS–AUC0–24 h and GIR–AUC0–24 h were 19% (95% CI: 14–25%) and 34% (24–43%), respectively. The diurnal relative fluctuation of the serum insulin glargine concentration was 20% (95% CI: 19–21%).Conclusion:  Insulin glargine in either formulation presents with a high day‐to‐day reproducibility of a uniform release after injection enabling an effective basal insulin supplementation.
Evidence that vildagliptin attenuates deterioration of glycaemic control during 2‐year treatment of patients with type 2 diabetes and mild hyperglycaemia*
Authors: Scherbaum W. A. , Schweizer A. , Mari A. , Nilsson P. M. , Lalanne G. , Wang Y. , Dunning B. E. , Foley J. E. 
Published: March 2008

Aim:  To assess the 2‐year efficacy and tolerability of vildagliptin (50 mg once daily) in patients with type 2 diabetes (T2DM) and mild hyperglycaemia.Methods:  This was a multicentre, randomized, double‐blind, placebo‐controlled trial comprising a 52‐week core study with a 4‐week, active treatment–free washout followed by a 52‐week extension study with another washout period conducted in 131 drug‐naïve patients with T2DM and mild hyperglycaemia [glycosylated haemoglobin (HbA1c) 6.2–7.2%]. All patients received lifestyle counselling at each study visit. Efficacy and tolerability were assessed during visits at weeks 0 (core study baseline), 4, 8, 12, 16, 24, 32, 40 and 52 of active treatment; at week 56 (i.e. after the first washout period); at weeks 68, 80, 96 and 108 and at week 112 (i.e. after the second washout period). Standard meal tests were also performed at weeks 0, 24, 52, 56, 80, 108 and 112 to assess postprandial glycaemia and β‐cell function, which was quantified by glucose area under the curve (AUC0–2 h)/insulin secretory rate (ISR) AUC0–2 h (ISR/G). Changes from baseline and between‐treatment differences (placebo‐adjusted changes from baseline during vildagliptin treatment) were analysed by ancova.Results:  The placebo‐adjusted change from week 0 in HbA1c was −0.3 ± 0.1% after 1 year of vildagliptin treatment (p < 0.001) and −0.5 ± 0.2% after 2 years (p = 0.008). The placebo‐adjusted change from core study baseline in fasting plasma glucose, in glucose AUC0–2 h and in the β‐cell function parameter, ISR/G, tended to be greater after 2 years than after 1 year of treatment with vildagliptin. Even after a 4‐week washout, the placebo‐adjusted change from week 0 to week 112 in ISR/G was 3.2 ± 1.6 pmol/min/m2/mM (p = 0.058) and the placebo‐adjusted difference in the change from week 0 to week 112 in HbA1c was −0.3 ± 0.1% (p = 0.051). The incidences of adverse events (AEs), serious AEs and discontinuations because of AEs were similar in the two treatment groups, and hypoglycaemic episodes were reported by no patient receiving vildagliptin and by two patients receiving placebo.Conclusions:  In drug‐naïve patients with mild hyperglycaemia, 2‐year treatment with vildagliptin 50 mg once daily attenuated the progressive loss of glycaemic control seen in patients receiving only lifestyle counselling (and placebo). This appears to be because of a corresponding attenuation of the deterioration of β‐cell function as assessed by ISR/G.