bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thyroid hormones as molecular determinants of thermogenesis
Authors: Silvestri E. , Schiavo L. , Lombardi A. , Goglia F. 
Published: July 2005

AbstractThyroid hormones (TH) are major modulators of energy metabolism and thermogenesis. It is generally believed that 3,5,3′‐triiodo‐l‐thyronine (T3) is the only active form of TH, and that most of its effects are mediated by nuclear T3 receptors, which chiefly affect the transcription of target genes. Some of these genes encode for the proteins involved in energy metabolism. However, a growing volume of evidence now indicates that other iodothyronines may be biologically active. Several mechanisms have been proposed to explain the calorigenic effect of TH, but none has received universal acceptance. Cold acclimation/exposure and altered nutritional status are physiological conditions in which a modulation of energy expenditure is particularly important. TH seem to be deeply involved in this modulation, and this article will review some aspects of their possible influence in these conditions.
NEAT – non‐exercise activity thermogenesis – egocentric & geocentric environmental factors vs. biological regulation
Authors: Levine J. A. , Kotz C. M. 
Published: July 2005

AbstractNon‐exercise activity thermogenesis (NEAT) is the energy expenditure of all physical activities other than volitional sporting‐like exercise. NEAT includes all those activities that render us vibrant, unique and independent beings such as going to work, playing guitar, toe‐tapping and dancing. The factors that account for the 2000 kcal day−1 variability of NEAT can be categorized as environmental or biological. The environmental determinants of NEAT can be view using one of two models. In the egocentric model we consider a single person as the focus, e.g. ‘my job’. In the geocentric model we consider the ‘environment’ as the focus, e.g. well‐lit and safe walk ways. These models provide us with a theoretical framework to understand NEAT and how best to intervene to promote NEAT. As well as environmental effectors of NEAT, there are also biological regulatory mechanisms that enable us to account for three‐quarters of the biological variance in susceptibility and resistance to fat gain with human over‐feeding. NEAT is likely to be regulated through a central mechanism that integrates NEAT with energy intake and energy stores so that NEAT is activated with over‐feeding and suppressed with under‐feeding. In conclusion, NEAT is likely to serve as a crucial thermoregulatory switch between energy storage and dissipation that is biologically regulated and influenced, and perhaps over‐ridden, by environment. Deciphering the role of NEAT may lead to a better understanding of the pathogenesis, prevention and treatment of obesity.
A review of an anaesthetic led vascular access list
Authors: Galloway S. , Sharma A. , Ward J. , Bodenham A. R. 
Published: July 2005

SummaryThe demand for insertion of long‐term central venous (Hickman type) catheters is thought to be increasing. Organisation is required to meet this demand in a safe and efficient manner. This report reviews the results from a dedicated, anaesthetic led vascular access list over the initial 61‐month period. One thousand procedures were performed. Nine hundred and twenty catheters were inserted under local anaesthesia, with or without intravenous sedation and analgesia. Eighty catheters were removed. All procedures were performed during a dedicated once weekly, morning list. A total of 53% of all procedures were performed on a day‐case basis, 43% on in‐patients. Only 1.5% of patients required an unexpected overnight stay (usually medically unfit patients). There were 81 (9%) cancellations on the day of procedure due to neutropaenia, pneumonia or urinary tract infections. Ultrasound guidance was used initially selectively in 14%, latterly in 100% of procedures and fluoroscopy in all insertions to confirm or adjust catheter position. This service has been well received by patients and oncology services. In addition it provides an interesting area of practice for anaesthetists and an ideal environment for teaching more advanced aspects of central venous access. It may provide a template of service for other centres.
Hypoxaemia during open‐airway apnoea: a computational modelling analysis
Authors: McNamara M. J. , Hardman J. G. 
Published: July 2005

SummaryHypoxaemia during open‐airway apnoea, e.g. during brainstem death testing, may cause organ damage. The effect of ambient oxygen fraction on the extent of hypoxaemia has not been established. We validated the Nottingham Physiology Simulator in this context by reproducing the methodologies and results of four published clinical studies. We then used the simulator to examine the effects of different ambient oxygen fractions (0.21–1.0) and shunt fractions (1–30% of cardiac output) during apnoea. Increasing ambient oxygen fraction from 0.9 to 1.0 more than doubled the time to haemoglobin desaturation at all shunt fractions, and extended apnoea longer than when the ambient oxygen fraction was increased from 0.21 to 0.9. When ambient oxygen fraction and shunt fraction were large, arterial oxygen tension transiently increased during apnoea. A very high ambient oxygen fraction and a patent airway are likely to delay dangerous hypoxaemia during apnoea.
Radial to femoral arterial blood pressure differences during liver transplantation
Authors: Arnal D. , Garutti I. , Perez‐Peña J. , Olmedilla L. , Tzenkov I. G. 
Published: July 2005

SummaryThis observational study compared femoral and radial arterial blood pressure in 72 patients undergoing liver transplant surgery. Simultaneous femoral and radial arterial blood pressures, cardiac index, core temperature and vasoconstrictor therapy were recorded at seven time points during the operation. No significant differences between radial and femoral pressures were found at the start of surgery. Femoral and radial systolic arterial blood pressures were statistically significantly different during liver reperfusion (mean (SD) arterial pressure = 92 (22) mmHg vs. 76 (22) mmHg, p < 0.01). Mean arterial blood pressures showed no statistically significant differences throughout the study. Vasoconstrictor drug administration was associated with a larger systolic pressure difference between femoral and radial arteries (28 (24) mmHg in patients being given vasoconstrictor drugs vs. 9 (19) mmHg in patients not needing vasoconstrictors during reperfusion, p < 0.001). In conclusion, differences in systolic arterial blood pressure occur between femoral and radial arterial monitoring sites during liver reperfusion, and in particular in patients being given vasoconstrictor therapy. Thus, if femoral arterial monitoring is not available, clinicians should rely on mean rather than systolic arterial pressure measurements from a radial artery catheter during liver transplantation.
Genome screen for twinning rate QTL in four North American Holstein families
Authors: Cobanoglu O. , Berger P. J. , Kirkpatrick B. W. 
Published: July 2005

SummaryThe objective of this study was to identify twinning rate quantitative trait loci (QTL) by typing pooled samples in a preliminary screening followed by interval mapping to test QTL effects. Four elite North American Holstein half‐sib sire families with high twinning rate predicted transmitting abilities (PTA) were used in this study. Chromosomes 5, 7, 19 and 23 were not genotyped as these chromosomes were scanned for QTL in these families in a previous study. DNA was extracted from phenotypically extreme sons in each sire family. Two pools were prepared from sons of sires in each phenotypic tail, two each for high and low PTA levels for twinning rates. Each pool contained DNA from 4 to 15% of all sons of the sire depending on family. A total of 268 fluorescently labelled microsatellite markers were tested for heterozygosity in sires. About 135–170 informative markers per family were genotyped using pooled DNA samples. Based on the preliminary evidence for potential twinning rate QTL from pooled typing, interval mapping was performed subsequently on 12 chromosomal regions by family combinations. Evidence of QTL for twinning rate was found in one family on BTA21 and 29 at a chromosome‐wide P < 0.05 and on BTA8, 10 and 14 with a chromosome‐wide P < 0.01.
Characterization and comparison of microsatellites derived from repeat‐enriched libraries and expressed sequence tags
Authors: Coulibaly I. , Gharbi K. , Danzmann R. G. , Yao J. , Rexroad C. E. 
Published: July 2005

SummaryThe construction of high‐density linkage maps for use in identifying loci underlying important traits requires the development of large numbers of polymorphic genetic markers spanning the entire genome at regularly spaced intervals. As part of our efforts to develop markers for rainbow trout (Oncorhynchus mykiss), we performed a comparison of allelic variation between microsatellite markers developed from expressed sequence tag (EST) data and anonymous markers identified from repeat‐enriched libraries constructed from genomic DNA. A subset of 70 markers (37 from EST databases and 33 from repeat enriched libraries) was characterized with respect to polymorphism information content (PIC), number of alleles, repeat number, locus duplication within the genome and ability to amplify in other salmonid species. Higher PIC was detected in dinucleotide microsatellites derived from ESTs than anonymous markers (72.7% vs. 54.0%). In contrast, dinucleotide repeat numbers were higher for anonymous microsatellites than for EST derived microsatellites (27.4 vs. 18.1). A higher rate of cross‐species amplification was observed for EST microsatellites. Approximately half of each marker type was duplicated within the genome. Unlike single‐copy markers, amplification of duplicated microsatellites in other salmonids was not correlated to phylogenetic distance. Genomic microsatellites proved more useful than EST derived microsatellites in discriminating among the salmonids. In total, 428 microsatellite markers were developed in this study for mapping and population genetic studies in rainbow trout.
Muscarinic cholinergic receptors in the human melanoma cell line SK-Mel 28: modulation of chemotaxis
Authors: Boss A. , Oppitz M. , Drews U. 
Published: July 2005

Summary
Primary and metastatic human melanomas express muscarinic receptors. In embryonic tissues, expression of muscarinic receptors is correlated with morphogenesis. The hypothesis has been put forward that muscarinic receptors are involved in morphogenetic movements in the embryo, and in cellular movements in melanoma cells during invasive growth. The purpose of the present study was to characterize the muscarinic receptors in the human melanoma cell line SK-Mel 28 and to test in a Boyden chamber assay whether the chemotactic activity towards fibronectin can be influenced by muscarinic stimulation. In Western blots with the monoclonal antibody M35, muscarinic receptors were localized in a strong band at 66 kDa, and in a weak band at 63 kDa. Western blot with M3 subtype specific antibodies reproduced the line at 66 kDa. RT-PCR revealed mRNA for subtypes M3 and M5. These findings suggest that SK-Mel 28 cells express a large number of subtype M3 and a small number of subtype M5 receptors. Microscopic observation of calcium mobilization after muscarinic stimulation indicated that all cells carried functional muscarinic receptors. A standardized chemotaxis assay was established in modified Boyden chambers using fibronectin as chemotactic agent. After addition of carbachol to the upper compartment, an increase of fibronectin induced chemotaxis of ∼30% was observed, an effect abrogated by atropine. These results demonstrate that muscarinic cholinergic treatment has a modulatory effect on fibronectin-induced chemotaxis in SK-Mel 28 melanoma cells, indicating that the muscarinic system is involved in regulation of cell movement.
Instrumentation and patient characteristics that influence postoperative haemorrhage rates following tonsil and adenoid surgery
Authors: Tomkinson A. , De Martin S. , Gilchrist C. R. , Temple M. 
Published: July 2005

Objectives:  To investigate the effect of the type instrumentation used and the age and gender characteristics of patients on postoperative haemorrhage rates following tonsil and adenoid surgery.Design:  A retrospective analysis of 13 593 procedures was performed from The Patient Episode Database for Wales between 1 January 1999 and 31 March 2004.Setting:  National health policy changes created four periods of different instrument usage (reusable, single‐use with diathermy, single‐use alone, specified single‐use with diathermy). These and the age and gender distribution of the patients were examined against four categories of postoperative haemorrhage.Main outcome measures:  Postoperative haemorrhage rates were expressed as the number of complications per operations performed. Primary postoperative haemorrhage that occurred during the initial admission either required a return to theatre [R1] or was managed conservatively [N1]; secondary postoperative haemorrhage that required a return to hospital either returned to theatre [R2] or was managed conservatively [N2], were compared.Results:  Primary haemorrhage with return to theatre doubled, from the baseline rate with reusable instruments, from 0.6% (CI 0.5–0.8) to 1.2% (CI 0.7–1.9) when single‐use instruments were introduced and remained high at 1.4% (CI 0.9–2.1) after the withdrawal of single‐use diathermy. This haemorrhage rate returned to the baseline rate (0.6% CI 0.3–1.0) when specified single‐use instruments were introduced. None of the other haemorrhage rates changed significantly throughout the four observation periods. Adenotonsillectomy and tonsillectomy patients have different age and gender patterns. In a univariate analysis, males over the age of 12 years were twice as likely to have haemorrhage with return to theatre than girls of the same age, 3.8% (CI 3.0–4.7) versus 1.7% (CI 1.4–2.1).Conclusions:  A significant rise in serious postoperative primary haemorrhage but not secondary haemorrhage was seen following the initial introduction of single‐use instruments that reverted to baseline with the introduction of specified single‐use instruments. Diathermy does not appear to have affected the haemorrhage rates. There is a distinct age and gender pattern for tonsil and adenoid surgery and risk of postoperative haemorrhage. The use of arbitrary divisions of age may be misleading in studies that examine post‐tonsillectomy haemorrhage.
Modelling denitrification including the dynamics of denitrifiers and their progressive ability to reduce nitrous oxide: comparison with batch experiments
Authors: Khalil K. , Renault P. , Guérin N. , Mary B. 
Published: July 2005

SummaryNitrous oxide contributes to the global greenhouse effect and affects the chemistry of O3 in the upper troposphere and lower stratosphere. To define a relevant model for microbial NO3– and N2O reductions in soil and estimate the parameters involved, we propose a method combining measurements of anaerobic soil slurry and simulations of NO3– and N2O reductions, including non‐enzymatic competition between NO3– and N2O as electron acceptors and the microbial dynamics of two denitrifier groups that are either able or unable to reduce N2O. Three models varying in the description of soil capability to reduce N2O through denitrification were assessed. The procedure was applied on an arable soil known for its small N2O emissions in situ during wet events. Experiments consisted of N2O measurements in anoxic conditions (i) with C2H2, (ii) without C2H2 or (iii) without C2H2 and N2O addition, at various NO3– concentrations. The first model that accounts for microbial growth and considers a constant specific N2O reductase activity could not reproduce experimental data. It was necessary to consider that some denitrifiers initially unable to reduce N2O into N2 became able to undertake this process. We evaluated two models taking into account the induction of N2O reductase, either with the progressive synthesis of this reductase simultaneously for all N2O reducers or with the sudden synthesis of this reductase distributed over a range of times for N2O reducers. Both models could approximately describe experimental kinetics, although some biases remained. The biomass of denitrifiers estimated by fitting simulated to experimental data was consistent with the biomass measured using chloroform fumigation–extraction and microbial enumeration.
Iron‐cyanide complexes in soil under varying redox conditions: speciation, solubility and modelling
Authors: Rennert T. , Mansfeldt T. 
Published: July 2005

SummaryThe distribution of iron‐cyanide complexes between ferrocyanide, [FeII(CN)6]4–, and ferricyanide, [FeIII(CN)6]3–, in soils on contaminated sites depends on the redox potential, EH. We carried out microcosm experiments in which ferrocyanide (20 mg l−1) was added to an uncontaminated moderately acidic subsoil (pH 5.2), and varied the EH of the soil suspension between 200 and 700 mV over up to 109 days. Ferrocyanide and ferricyanide were analysed by capillary isotachophoresis. At redox potentials ranging from 400 to 700 mV, small amounts of iron‐cyanide complexes were adsorbed, and ferrocyanide was almost completely oxidized to ferricyanide. Decreasing EH to 200 mV led to nearly complete removal of iron‐cyanide complexes from solution, and the complexes were not mobilized after subsequent aeration (EH > 350 mV). Under weakly to moderately reducing conditions (EH ≈ 200 mV), iron‐cyanide complexes were removed from solution by precipitation, which occurred, presumably in the form of e.g. Fe2[FeII(CN)6], Fe4[FeII(CN)6]3 or Mn2[FeII(CN)6], after reductive dissolution of Mn and Fe oxides. Four different sets of geochemical model calculations were carried out. The species distribution between ferrocyanide and ferricyanide in solution was predicted reliably under varying pH and redox conditions when iron‐cyanide complex concentrations and Fe concentrations, excluding Fe bound in iron‐cyanide complexes, were used in model calculations. In model calculations on the fate of iron‐cyanide complexes in soil, adsorption reactions must be considered, especially under oxidizing conditions. Otherwise, the calculated iron‐cyanide complex concentrations are larger than those actually measured.
Bacteria and algae in stream periphyton along a nutrient gradient
Authors: CARR GENEVIÈVE M. , MORIN ANTOINE , CHAMBERS PATRICIA A. 
Published: July 2005

Summary1. Stream riffles in southern Ontario and western Quèbec were sampled for biomass (58 stations from 51 streams) and production (22 stations from 21 streams) of algae and bacteria in periphyton to test the hypothesis that bacteria in benthic biofilms compete with algae for nutrients.2. Algal and bacterial biomass were positively correlated, as were algal and bacterial production. Bacterial production was also positively correlated to algal and bacterial biomass, but the relationship was not significant. The ratio of algal to bacterial biomass did not vary with nutrients whereas algal production tended to increase with nutrients more rapidly than bacterial production.3. Instream nitrogen concentrations explained 38–58% of the variability in algal biomass and production. Bacterial abundance explained an additional 9–29% of the residual variance in algal production and biomass. However, the relationship between bacterial abundance and algal production and biomass, once nutrients were taken into account, was positive, in contrast to the predicted effect of competition.4. Hence, we reject our original hypothesis that bacteria in biofilms compete with algae for nutrients and instead suggest that bacteria and algae in biofilms coexist in an association that offers space and resources to sustain production of both groups of organisms.
Changes in biotic communities developing from freshwater wetland sediments under experimental salinity and water regimes
Authors: BROCK MARGARET A. , NIELSEN DARYL L. , CROSSLÉ KATHARINE 
Published: July 2005

Summary1. Reduction in diversity of both freshwater aquatic and terrestrial ecosystems has been attributed to salinity increase and such increases are a symptom of changes to land use. Hydrological alteration to ground and surface water are likely to be associated with salinity increase and its influence on biodiversity. However the combined effects of salinity and hydrology on aquatic biodiversity have not been elucidated fully in either field or experimental situations.2. The effect of salinity and water regime on the biota in sediments from seven wetlands from inland south‐eastern Australia was tested experimentally using germination of aquatic plant seeds (five salinity and two water levels) and emergence of zooplankton eggs (five salinity levels). Salinity levels were <300, 1000, 2000, 3000, 5000 mg L−1 and water regimes were damp (waterlogged) and submerged.3. Aquatic plant germination and zooplankton hatching was not consistent for all seven wetland sediments. Four of the wetland sediments, Narran Lakes, Gwydir Wetlands, Macquarie Marshes and Billybung Lagoon showed similar responses to salinity and water regime but the other three wetland sediments from Lake Cowal, Great Cumbung Swamp and Darling Anabranch did not.4. As salinity increased above 1000 mg L−1 there was a decrease in the species richness and the abundance of biota germinating or hatching from sediment from four of the wetlands.5. Salinity had a particularly strong effect in reducing germination from sediments in damp conditions when compared to the flooded conditions. In parallel, salts accumulated in the sediment in damp conditions but did not in flooded conditions.6. There is potential for increasing salinity in freshwater rivers and wetlands to decrease the species richness of aquatic communities and thus of the wetland community as a whole, resulting in loss of wetland biodiversity. This reduction in diversity varies between wetlands and is at least partly related to hydrology. For aquatic plants the reduction in diversity will be more marked for plants germinating from seed banks at the edges of wetlands where plants are not completely submerged than for the same seed bank germinating in submerged conditions.
A seasonally breeding tropical bird lacks absolute photorefractoriness in the wild, despite high photoperiodic sensitivity
Authors: BEEBE K. , BENTLEY G. E. , HAU M. 
Published: July 2005

Summary

Photoperiod is an important seasonal cue for temperate seasonal breeders. In birds, increasing photoperiod typically stimulates reproductive maturation, while also triggering gonad regression through photorefractoriness at a later date. Curiously, many tropical birds show photoperiodic reproductive responses, even though day‐length changes in their natural habitat are minimal.
Spotted Antbirds (Hylophylax n. naevioides) from a near‐equatorial rainforest in Panama are highly sensitive to small photoperiodic changes at the onset of reproduction. We therefore tested whether these tropical birds use photoperiod as the primary signal for seasonal processes, as do most temperate birds, and terminate reproduction through photorefractoriness.
Male and female Spotted Antbirds captured during postbreeding moult significantly increased gonad sizes when exposed to a photoperiod of 22 h. Furthermore, males exposed to a naturalistic 1‐h increase in photoperiod (to 13 h) also grew their gonads, suggesting that these birds retain photosensitivity at a time of year when most temperate birds are unable to grow their gonads. Hatch‐year birds in all groups showed reproductive development indicating their capability to breed. Unlike in many temperate‐zone birds, the moult of adult birds was not inhibited by gonad development.
The lack of photorefractoriness allows Spotted Antbirds to flexibly adjust the end of breeding to environmental conditions. Our findings support the view that photoperiodic mechanisms are evolutionary plastic and match the ecology of a particular species.