bluuebunny/crossref_metadata_2025_split huggingface dataset:
Minireview: Role of Protein Methylation and Demethylation in Nuclear Hormone Signaling
Authors: Wu Susan C. , Zhang Yi 
Published: May 2009

Abstract
Nuclear hormone receptors (NRs) are transcription factors responsible for mediating the biological effects of hormones during development, metabolism, and homeostasis. Induction of NR target genes is accomplished through the assembly of hormone-bound NR complexes at target promoters and coincides with changes in histone modifications that promote transcription. Some coactivators and corepressors of NR can enhance or inhibit NR function by covalently modifying histones. One such modification is methylation, which plays important roles in transcriptional regulation. Histone methylation is catalyzed by histone methyltransferases and reversed by histone demethylases. Recent studies have uncovered the importance of these enzymes in the regulation of NR target genes. In addition to histones, these enzymes have nonhistone substrates and can methylate and demethylate NRs and coregulatory proteins in order to modulate their function. This review discusses recent progress in our understanding of the role of methylation and demethylation of histones, NRs, and their coregulators in NR-mediated transcription.
Tracking stress: localisation, deposition and stability of corticosterone in feathers
Authors: Bortolotti Gary R. , Marchant Tracy , Blas Julio , Cabezas Sonia 
Published: May 2009

SUMMARY
How animals cope with stressors is an important determinant of their well being and fitness. Understanding what environmental perturbations are perceived as stressors, and quantifying how they are responded to, how often they occur and the negative consequences of exposure to glucocorticoids, has been problematic and limited to short-term physiological measures. By contrast, the quantification of corticosterone (CORT) in feathers represents a long-term, integrated measure of hypothalamic–pituitary–adrenal activity. In the present study, we show that by understanding how the hormone is deposited in feathers, in combination with specific sampling protocols, one can identify localised patterns of CORT deposition that reveal different temporal patterns of a bird's response to stressors. CORT in feathers appears to be stable over time, is resistant to heat exposure and is useful in determining both the overall exposure of the bird to the hormone over days or weeks, as well as identifying discrete, punctuated, stressful events. Variation in feather CORT can also be examined among individuals of a population at one point in time, as well as over years by using museum specimens. The ability to track stress over time allows for new questions to be asked about the health and ecology of birds and their environment.
The role of insulin and glucose in goose primary hepatocyte triglyceride accumulation
Authors: Han Chunchun , Wang Jiwen , Li Liang , Zhang Zhongxian , Wang Li , Pan Zhixiong 
Published: May 2009

SUMMARYIn order to obtain some information on how fatty liver arises in geese, we investigated the role of insulin and glucose in triglyceride (TG) accumulation in goose primary hepatocytes. Goose primary hepatocytes were isolated and treated with insulin and glucose. Compared with the control group, 100 and 150 nmol l–1 insulin increased TG accumulation, acetyl-CoA carboxylase-α (ACCα) and fatty acid synthase (FAS)activity, and the mRNA levels of sterol regulatory element-binding protein-1(SREBP-1), FAS and ACCα genes. Insulin at 200 nmol l–1 had an inhibiting effect on TG accumulation and the activity of ACC and FAS, but increased the gene expression of SREBP-1, FAS and ACCα. We also found that high glucose (30 mmol l–1)increased the TG level, ACC and FAS activity, and the mRNA levels of SREBP-1 and FAS. However, there was no effect of high glucose on ACCα mRNA level. In addition, the interaction between insulin and glucose was observed to induce TG accumulation, ACC and FAS activity, and gene expression of SREBP-1, FAS and ACCα, and increase SREBP-1 nuclear protein level and binding of nuclear SREBP-1 and the SRE response element of the ACCgene. The result also indicated that the glucose-induced TG accumulation decreased after 96 h when the hepatocytes were cultured with 30 mmol l–1 glucose. In conclusion, insulin and glucose may affect hepatic lipogenesis by regulating lipogenic gene expression and lipogenic enzyme activity in goose hepatocytes, and SREBP-1 might play an important role in the synergetic activation of lipogenic genes. We propose that the utilization of accumulated TG in hepatocytes is the reason for the reversible phenomenon in goose hepatocellular steatosis.
Ontogeny of joint mechanics in squirrel monkeys (Saimiri boliviensis): functional implications for mammalian limb growth and locomotor development
Authors: Young Jesse W. 
Published: May 2009

SUMMARYJuvenile animals must often compete against adults for common resources,keep pace during group travel and evade common predators, despite reduced body size and an immature musculoskeletal system. Previous morphometric studies of a diverse array of mammals, including jack rabbits, cats and capuchin monkeys,have identified growth-related changes in anatomy, such as negative allometry of limb muscle mechanical advantage, which should theoretically permit young mammals to overcome such ontogenetic limits on performance. However, it is important to evaluate the potential impact of such `compensatory' growth trajectories within the context of developmental changes in locomotor behavior. I used standard kinematic and kinetic techniques to investigate the ontogenetic scaling of joint postures, substrate reaction forces, joint load arm lengths and external joint moments in an ontogenetic sample of squirrel monkeys (Saimiri boliviensis). Results indicated that young squirrel monkeys were frequently able to limit forelimb and hind limb joint loading via a combination of changes in limb posture and limb force distribution,potentially compensating for limited muscularity at younger ages. These results complement previous morphometric studies and suggest that immature mammals may utilize a combination of behavioral and anatomical mechanisms to mitigate ontogenetic limits on locomotor performance. However, ontogenetic changes in joint posture, not limb length per se, explained most of the variation in load arm lengths and joint loading in growing squirrel monkeys, indicating the importance of incorporating both anatomical and performance measures when studying the ontogeny of limb joint mechanics.
Pulsed jet dynamics of squid hatchlings at intermediate Reynolds numbers
Authors: Bartol Ian K. , Krueger Paul S. , Stewart William J. , Thompson Joseph T. 
Published: May 2009

SUMMARYSquid paralarvae (hatchlings) rely predominantly on a pulsed jet for locomotion, distinguishing them from the majority of aquatic locomotors at low/intermediate Reynolds numbers (Re), which employ oscillatory/undulatory modes of propulsion. Although squid paralarvae may delineate the lower size limit of biological jet propulsion, surprisingly little is known about the hydrodynamics and propulsive efficiency of paralarval jetting within the intermediate Re realm. To better understand paralarval jet dynamics, we used digital particle image velocimetry(DPIV) and high-speed video to measure bulk vortex properties (e.g. circulation, impulse, kinetic energy) and other jet features [e.g. average and peak jet velocity along the jet centerline (Uj and Ujmax, respectively), jet angle, jet length based on the vorticity and velocity extents (Lω and LV, respectively), jet diameter based on the distance between vorticity peaks (Dω), maximum funnel diameter (DF), average and maximum swimming speed(U and Umax, respectively)] in free-swimming Doryteuthis pealeii paralarvae (1.8 mm dorsal mantle length)(Resquid=25–90). Squid paralarvae spent the majority of their time station holding in the water column, relying predominantly on a frequent, high-volume, vertically directed jet. During station holding,paralarvae produced a range of jet structures from spherical vortex rings(Lω/Dω=2.1, LV/DF=13.6) to more elongated vortex ring structures with no distinguishable pinch-off(Lω/Dω=4.6, LV/DF=36.0). To swim faster,paralarvae increased pulse duration and Lω/Dω, leading to higher impulse but kept jet velocity relatively constant. Paralarvae produced jets with low slip, i.e. ratio of jet velocity to swimming velocity(Uj/U or Ujmax/Umax), and exhibited propulsive efficiency [ηpd=74.9±8.83% (±s.d.) for deconvolved data] comparable with oscillatory/undulatory swimmers. As slip decreased with speed, propulsive efficiency increased. The detection of high propulsive efficiency in paralarvae is significant because it contradicts many studies that predict low propulsive efficiency at intermediate Re for inertial forms of locomotion.
Cloning and functional expression of the first eukaryotic Na+–tryptophan symporter, AgNAT6
Authors: Meleshkevitch Ella A. , Robinson Marvin , Popova Lyudmila B. , Miller Melissa M. , Harvey William R. , Boudko Dmitri Y. 
Published: May 2009

SUMMARY
The nutrient amino acid transporter (NAT) subfamily of the neurotransmitter sodium symporter family (NSS, also known as the solute carrier family 6, SLC6)represents transport mechanisms with putative synergistic roles in the absorption of essential and conditionally essential neutral amino acids. It includes a large paralogous expansion of insect-specific genes, with seven genes from the genome of the malaria mosquito, Anopheles gambiae. One of the An. gambiae NATs, AgNAT8, was cloned, functionally expressed and characterized in X. laevis oocytes as a cation-coupled symporter of aromatic amino acids, preferably l-phenylalanine, l-tyrosine and l-DOPA. To explore an evolutionary trend of NAT-SLC6 phenotypes, we have cloned and characterized AgNAT6, which represents a counterpart of AgNAT8 descending from a recent gene duplication(53.1% pairwise sequence identity). In contrast to AgNAT8, which preferably mediates the absorption of phenol-branched substrates, AgNAT6 mediates the absorption of indole-branched substrates with highest apparent affinity to tryptophan (K0.5Trp=1.3 μmol l–1vs K0.5Phe=430 μmol l–1) and [2 or 1 Na+ or K+]:[aromatic substrate] stoichiometry. AgNAT6 is highly transcribed in absorptive and secretory regions of the alimentary canal and specific neuronal structures,including the neuropile of ventral ganglia and sensory afferents. The alignment of AgNATs and LeuTAa, a bacterial NAT with a resolved 3D structure, reveals three amino acid differences in the substrate-binding pocket that may be responsible for the indole- vs phenol-branch selectivity of AgNAT6 vs AgNAT8. The identification of transporters with a narrow selectivity for essential amino acids suggests that basal expansions in the SLC6 family involved duplication and retention of NATs,improving the absorption and distribution of under-represented essential amino acids and related metabolites. The identified physiological and expression profiles suggest unique roles of AgNAT6 in the active absorption of indole-branched substrates that are used in the synthesis of the neurotransmitter serotonin as well as the key circadian hormone and potent free-radical scavenger melatonin.
Desert ants do not rely on sky compass information for the perception of inclined path segments
Authors: Heß Doreen , Koch Julja , Ronacher Bernhard 
Published: May 2009

SUMMARY
On their foraging excursions, desert ants (Cataglyphis fortis)navigate by means of path integration, exhibiting high precision even in undulating terrain. To avoid errors in their home vector the ants must measure the slopes of ascents and descents in their itinerary. This information is necessary to convert the distances actually walked on the slopes into the ground distance, which is the crucial parameter for vector navigation. However, it is as yet unknown how Cataglyphis perceives the slopes of inclines. We asked whether the ants gauge slopes by means of the changes in the sky's polarization pattern or the sun's position imposed by the unusual head posture when walking on inclines. During training on a ramp, we manipulated the sky compass cues available for the ants. If both sky compass cues, polarization pattern and sun position, were excluded during ramp training, the ants behaved in subsequent tests as if they had never encountered a slope. However, the presence of either of the two compass cues was sufficient for the ants to memorize the sloped path segment. In a third experiment, the supposed polarization cue was excluded by covering the training and test channels with a linear polarization filter. In these tests the ants clearly showed that they had perceived and memorized an ascent also without a change in the polarization pattern. Hence, changes in polarization perception can be ruled out as the crucial cue for gauging slopes, and we conclude that slopes are monitored by a, still unknown, proprioceptive mechanism.
Increased locomotor activity and metabolism ofAedes aegyptiinfected with a life-shortening strain ofWolbachia pipientis
Authors: Evans Oliver , Caragata Eric P. , McMeniman Conor J. , Woolfit Megan , Green David C. , Williams Craig R. , Franklin Craig E. , O'Neill Scott L. , McGraw Elizabeth A. 
Published: May 2009

SUMMARYA virulent strain of the obligate intracellular bacterium Wolbachia pipientis that shortens insect lifespan has recently been transinfected into the primary mosquito vector of dengue virus, Aedes aegypti L. The microbe's ability to shorten lifespan and spread through host populations under the action of cytoplasmic incompatibility means it has the potential to be used as a biocontrol agent to reduce dengue virus transmission. Wolbachia is present in many host tissues and may have local effects on diverse biological processes. In other insects, Wolbachiainfections have been shown to alter locomotor activity and response time to food cues. In mosquitoes, locomotor performance relates to the location of mates, human hosts, resting sites and oviposition sites. We have therefore examined the effect of the virulent, life-shortening Wolbachia strain wMelPop on the locomotion of Ae. aegypti as they age and as the pathogenicity of the infection increases. In parallel experiments we also examined CO2 production as a proxy for metabolic rate, to investigate a potential mechanistic explanation for any changes in locomotion. Contrary to expectation, we found that the infection increased activity and metabolic rate and that these effects were relatively consistent over the insect's lifespan. The results do not fit a standard model of bacterial pathogenesis in insects, and instead may reveal additional physiological changes induced by infection, such as either increased hunger or defects in the nervous system.
Characterization of lubricants for metal forming by means of an oscillating tribo-test-rig
Authors: Monetti C , Ilo S , Lebersorger T 
Published: May 2009

Cold metal forming is a versatile and very efficient technology in the manufacture of metal components. In cold metal forming processes high pressure is generated at the tool-workpiece interface, so that good lubrication is required to reduce wear. This improves tool life and the quality of products. The lubricants used in the forming processes usually contain appropriate basis oils with anti-wear (AW) and extreme pressure (EP) additives. In order to examine how wear occurs during cold metal forming, the SRV (Schwingung Reibung Verschleiss) reciprocating-sliding tribometer equipped with a cylinder-on-disc line- contact testing system was adapted and used to characterize lubricant behaviour. Friction coefficient and wear rate were determined under progressively increasing load conditions. The final worn volumes of the flat and the cylinder were evaluated by using optical microscopy methods. The measurement system was validated by replicate tests using some commercially available forming lubricants as reference in a load range of 100-1000 N. The oscillating tribo-test-rig can be used to characterize lubricants for cold metal forming processes by testing the combined effects of different additive systems and their interaction with contacting materials.
Circulating Methylated SEPT9 DNA in Plasma Is a Biomarker for Colorectal Cancer
Authors: deVos Theo , Tetzner Reimo , Model Fabian , Weiss Gunter , Schuster Matthias , Distler Jürgen , Steiger Kathryn V , Grützmann Robert , Pilarsky Christian , Habermann Jens K , Fleshner Phillip R , Oubre Benton M , Day Robert , Sledziewski Andrew Z , Lofton-Day Catherine 
Published: May 2009

Abstract
Background: The presence of aberrantly methylated SEPT9 DNA in plasma is highly correlated with the occurrence of colorectal cancer. We report the development of a new SEPT9 biomarker assay and its validation in case–control studies. The development of such a minimally invasive blood-based test may help to reduce the current gap in screening coverage.
Methods: A new SEPT9 DNA methylation assay was developed for plasma. The assay comprised plasma DNA extraction, bisulfite conversion of DNA, purification of bisulfite-converted DNA, quantification of converted DNA by real-time PCR, and measurement of SEPT9 methylation by real-time PCR. Performance of the SEPT9 assay was established in a study of 97 cases with verified colorectal cancer and 172 healthy controls as verified by colonoscopy. Performance based on predetermined algorithms was validated in an independent blinded study with 90 cases and 155 controls.
Results: The SEPT9 assay workflow yielded 1.9 μg/L (CI 1.3–3.0) circulating plasma DNA following bisulfite conversion, a recovery of 45%–50% of genomic DNA, similar to yields in previous studies. The SEPT9 assay successfully identified 72% of cancers at a specificity of 93% in the training study and 68% of cancers at a specificity of 89% in the testing study.
Conclusions: Circulating methylated SEPT9 DNA, as measured in the new mSEPT9 assay, is a valuable biomarker for minimally invasive detection of colorectal cancer. The new assay is amenable to automation and standardized use in the clinical laboratory.
Identification and Prevention of Genotyping Errors Caused by G-Quadruplex– and i-Motif–Like Sequences
Authors: Wenzel Jürgen J , Rossmann Heidi , Fottner Christian , Neuwirth Stefan , Neukirch Carolin , Lohse Peter , Bickmann Julia K , Minnemann Timo , Musholt Thomas J , Schneider-Rätzke Brigitte , Weber Matthias M , Lackner Karl J 
Published: May 2009

Abstract
Background: Reliable PCR amplification of DNA fragments is the prerequisite for most genetic assays. We investigated the impact of G-quadruplex– or i-motif–like sequences on the reliability of PCR-based genetic analyses.
Methods: We found the sequence context of a common intronic polymorphism in the MEN1 gene (multiple endocrine neoplasia I) to be the cause of systematic genotyping errors by inducing preferential amplification of one allelic variant [allele dropout (ADO)]. Bioinformatic analyses and pyrosequencing-based allele quantification enabled the identification of the underlying DNA structures.
Results: We showed that G-quadruplex– or i-motif–like sequences can reproducibly cause ADO. In these cases, amplification efficiency strongly depends on the PCR enzyme and buffer conditions, the magnesium concentration in particular. In a randomly chosen subset of candidate single-nucleotide polymorphisms (SNPs) defined by properties deduced from 2 originally identified ADO cases, we confirmed preferential PCR amplification in up to 50% of the SNPs. We subsequently identified G-quadruplex and i-motifs harboring a SNP that alters the typical motif as the cause of this phenomenon, and a genomewide search based on the respective motifs predicted 0.5% of all SNPs listed by dbSNP and Online Mendelian Inheritance in Man to be potentially affected.
Conclusions: Undetected, the described phenomenon produces systematic errors in genetic analyses that may lead to misdiagnoses in clinical settings. PCR products should be checked for G-quadruplex and i-motifs to avoid the formation of ADO-causing secondary structures. Truly affected assays can then be identified by a simple experimental procedure, which simultaneously provides the solution to the problem. .
Effect of remifentanil hydrochloride administered via constant rate infusion on the minimum alveolar concentration of isoflurane in cats
Authors: Ferreira Tatiana H. , Aguiar Antonio J. A. , Valverde Alexander , Neto Francisco J. Teixeira , Steagall Paulo V. M. , Soares João H. N. 
Published: May 2009

Abstract
Objective—To evaluate the effects of increasing doses of remifentanil hydrochloride administered via constant rate infusion (CRI) on the minimum alveolar concentration (MAC) of isoflurane in cats.
Animals—6 healthy adult cats.
Procedures—For each cat, 2 experiments were performed (2-week interval). On each study day, anesthesia was induced and maintained with isoflurane; a catheter was placed in a cephalic vein for the administration of lactated Ringer's solution or remifentanil CRIs, and a catheter was placed in the jugular vein for collection of blood samples for blood gas analyses. On the first study day, individual basal MAC (MACBasal) was determined for each cat. On the second study day, 3 remifentanil CRIs (0.25, 0.5, and 1.0 μg/kg/min) were administered (in ascending order); for each infusion, at least 30 minutes elapsed before determination of MAC (designated as MACR0.25, MACR0.5, and MACR1.0, respectively). A 15-minute washout period was allowed between CRIs. A control MAC (MACControl) was determined after the last remifentanil infusion.
Results—Mean ± SD MACBasal and MACControl values at sea level did not differ significantly (1.66 ± 0.08% and 1.52 ± 0.21%, respectively). The MAC values determined for each remifentanil CRI did not differ significantly. However, MACR0.25, MACR0.5, and MACR1.0 were significantly decreased, compared with MACBasal, by 23.4 ± 7.9%, 29.8 ± 8.3%, and 26.0 ± 9.4%, respectively.
Conclusions and Clinical Relevance—The 3 doses of remifentanil administered via CRI resulted in a similar degree of isoflurane MAC reduction in adult cats, indicating that a ceiling effect was achieved following administration of the lowest dose.
Assessment of cytologic evaluation of preputial epithelial cells as a diagnostic test for detection of adrenocortical disease in castrated ferrets
Authors: Protain Holly J. , Kutzler Michelle A. , Valentine Beth A. 
Published: May 2009

Abstract
Objective—To determine whether results of cytologic evaluation of preputial epithelial cells correspond to results of a serum endocrine hormone assay and clinical signs associated with adrenocortical disease in castrated ferrets.
Animals—13 clinically normal ferrets and 8 ferrets with signs of adrenocortical disease.
Procedures—Blood and preputial lavage samples were collected from each ferret. Serum samples were submitted to the University of Tennessee Veterinary Diagnostic Laboratory for performance of an endocrine hormone assay. Differential epithelial cell counts were performed on preputial lavage samples to determine the percentage of cornified cells. Results of cytologic evaluation were compared with results of the endocrine hormone assay and clinical status of ferrets.
Results—The percentage of cornified preputial epithelial cells was not significantly correlated with serum 17B-estradiol or androstenedione concentration but was significantly correlated with serum 17-hydroxyprogesterone concentration (r = 0.60). The percentage of cornified preputial epithelial cells was higher in ferrets with clinical signs of adrenocortical disease (mean ± SD, 71.3 ± 16.9%) than in clinically normal ferrets (55.5 ± 19.0%).
Conclusions and Clinical Relevance—Cornification of preputial epithelial cells was correlated with an increase in serum 17-hydroxyprogesterone concentration as well as clinical signs of adrenocortical disease in castrated ferrets. Additional investigation is needed to elucidate the mechanism of preputial epithelial cell cornification in castrated ferrets.