bluuebunny/crossref_metadata_2025_split huggingface dataset:
Acclimation to different thermal conditions in a northerly wintering shorebird is driven by body mass-related changes in organ size
Authors: Vézina François , Jalvingh Kirsten M. , Dekinga Anne , Piersma Theunis 
Published: August 2006

SUMMARYSeasonal acclimatization and experimental acclimation to cold in birds typically results from increased shivering endurance and elevated thermogenic capacity leading to improved resistance to cold. A wide array of physiological adjustments, ranging from biochemical transformations to organ mass variations, are involved in this process. Several studies have shown that improved cold endurance is accompanied by increases in summit metabolic rate(Msum), a measure of maximal heat production and an indicator of the level of sustainable thermogenic capacity. However, improved endurance to cold can also be achieved without significant changes in Msum. The same is true for basal metabolic rate (BMR),which is known to increase in association with cold acclimatization or acclimation in some species but not in others. We investigated cold acclimation in a migrant shorebird known for extreme physiological flexibility, the red knot (Calidris canutus, the northerly wintering subspecies islandica). We measured BMR and Msumover two months in birds caught in the wild and transferred to experimentally controlled conditions representative of aspects of their seasonal thermal environment (two groups at constant 25°C, one group at constant 4°C and two groups experiencing variable outdoor temperatures). Birds maintained in both cold and variable ambient temperatures showed a 14-15% higher body mass, 33-45% higher food intake, and 26% and 13% elevations in BMR and Msum, respectively, compared with birds kept at thermoneutrality. These results, together with data on alimentary tract size and pectoral muscle thickness measured by ultrasonography, suggest that red knots acclimate to cold primarily through modulation of (lean) body mass components. Heavier individuals have larger muscles, which allow higher maximal heat production and better thermal compensation. Cold acclimation effects on BMR are most probably due to changes in the size of visceral organs, although not the alimentary tract in this specific case. The liver,known for its thermogenic capacity, is a probable candidate. Overall, our results indicate that relatively small changes in body mass and muscle size allow enough reserve capacity in terms of heat production to cope with typical wintering ambient temperature variations as measured on the red knot's wintering grounds.
Molecular and cellular characterization of a new aquaporin, AQP-x5,specifically expressed in the small granular glands ofXenopusskin
Authors: Kubota Makoto , Hasegawa Takahiro , Nakakura Takashi , Tanii Haruna , Suzuki Masakazu , Tanaka Shigeyasu 
Published: August 2006

SUMMARYA new toad aquaporin (AQP) cDNA was cloned from a cDNA library constructed from the ventral skin of Xenopus laevis. This AQP (XenopusAQP-x5) consisted of 273 amino acid residues with a high sequence homology to mammalian AQP5. The predicted amino acid sequence contained the two conserved Asn-Pro-Ala motifs found in all major intrinsic protein (MIP) family members and six putative transmembrane domains. The sequence also contained a mercurial-sensitive cysteine and a putative phosphorylation motif site for protein kinase A at Ser-257. The swelling assay using Xenopus oocytes revealed that AQP-x5 facilitated water permeability. Expression of AQP-x5 mRNA was restricted to the skin, brain, lungs and testes. Immunofluorescence and immunoelectron microscopical studies using an anti-peptide antibody (ST-156)against the C-terminal region of the AQP-x5 protein revealed the presence of immunopositive cells in the skin, with the label predominately localized in the apical plasma membrane of the secretory cells of the small granular glands. These glands are unique both in being close to the epidermal layer of the skin and in containing mitochondria-rich cells with vacuolar H+-ATPase dispersed among its secretory cells. Results from immunohistochemical experiments on the mucous or seromucous glands of several other anurans verified this result. We conclude that the presence of AQP-x5 in the apical plasma membrane of the small granular glands suggests its involvement in water secretion from the skins. The physiological roles of the AQP-x5 protein in the small or mucous glands are discussed.
Regulation of osmotic stress transcription factor 1 (Ostf1) in tilapia(Oreochromis mossambicus) gill epithelium during salinity stress
Authors: Fiol Diego F. , Chan Stephanie Y. , Kültz Dietmar 
Published: August 2006

SUMMARYMechanisms of induction of osmotic stress transcription factor 1 (Ostf1)were analyzed in gill epithelium of tilapia exposed to salinity stress. Experiments with primary cultures of gill epithelial cells revealed that hyperosmotic Ostf1 induction was independent of systemic factors. In addition,the synthetic glucocorticoid receptor agonist dexamethasone did not affect Ostf1 levels, arguing against cortisol being the signal for Ostf1 induction during hyperosmotic stress. Exposure of primary gill cell cultures to a hyperosmotic agent that is cell permeable and non-hypertonic (glycerol) did not trigger Ostf1 induction. However, when gill cells were exposed to hypertonicity (either in the form of NaCl or other forms) Ostf1 was rapidly and significantly induced. Analysis of hnRNA and mRNA levels revealed that Ostf1 upregulation in gill cells of intact fish and primary cultures of gill epithelial cells was mediated by transient mRNA stabilization. In addition to the initial transient mRNA stabilization a subsequent transcriptional induction of Ostf1 was observed. In cultured gill cells increase in Ostf1 mRNA synthesis was stable and very potent, whereas in gill cells of intact fish this increase was transient. This observation suggests positive feedback by Ostf1 or one of its targets and negative feedback by systemic factors on Ostf1 transcription.We conclude that Ostf1 induction in gill epithelial cells of tilapia exposed to salinity stress (1) is independent of cortisol or other systemic factors; (2) depends on hypertonicity as the signal; and (3) is based on transient mRNA stabilization. Moreover, our data on primary cell cultures show that systemic signals are necessary to prevent sustained transcriptional induction of Ostf1 during hyperosmotic stress, indicating feedback regulation and a high degree of complexity of osmosensing and signaling networks in euryhaline fishes.
Beauty in the eye of the beholder: the two blue opsins of lycaenid butterflies and the opsin gene-driven evolution of sexually dimorphic eyes
Authors: Sison-Mangus Marilou P. , Bernard Gary D. , Lampel Jochen , Briscoe Adriana D. 
Published: August 2006

SUMMARYAlthough previous investigations have shown that wing coloration is an important component of social signaling in butterflies, the contribution of opsin evolution to sexual wing color dichromatism and interspecific divergence remains largely unexplored. Here we report that the butterfly Lycaena rubidus has evolved sexually dimorphic eyes due to changes in the regulation of opsin expression patterns to match the contrasting life histories of males and females. The L. rubidus eye contains four visual pigments with peak sensitivities in the ultraviolet (UV;λ max=360 nm), blue (B; λmax=437 nm and 500 nm, respectively) and long (LW; λmax=568 nm) wavelength range. By combining in situ hybridization of cloned opsinencoding cDNAs with epi-microspectrophotometry, we found that all four opsin mRNAs and visual pigments are expressed in the eyes in a sex-specific manner. The male dorsal eye, which contains only UV and B (λmax=437 nm)visual pigments, indeed expresses two short wavelength opsin mRNAs, UVRh and BRh1. The female dorsal eye, which also has the UV and B (λmax=437 nm) visual pigments, also contains the LW visual pigment, and likewise expresses UVRh, BRh1 and LWRh mRNAs. Unexpectedly, in the female dorsal eye, we also found BRh1 co-expressed with LWRh in the R3-8 photoreceptor cells. The ventral eye of both sexes, on the other hand, contains all four visual pigments and expresses all four opsin mRNAs in a non-overlapping fashion. Surprisingly, we found that the 500 nm visual pigment is encoded by a duplicate blue opsin gene, BRh2. Further, using molecular phylogenetic methods we trace this novel blue opsin gene to a duplication event at the base of the Polyommatine+Thecline+Lycaenine radiation. The blue opsin gene duplication may help explain the blueness of blue lycaenid butterflies.
Decreased expression of myogenic transcription factors and myosin heavy chains inCaenorhabditis elegansmuscles developed during spaceflight
Authors: Higashibata Akira , Szewczyk Nathaniel J. , Conley Catharine A. , Imamizo-Sato Mari , Higashitani Atsushi , Ishioka Noriaki 
Published: August 2006

SUMMARYThe molecular mechanisms underlying muscle atrophy during spaceflight are not well understood. We have analyzed the effects of a 10-day spaceflight on Caenorhabditis elegans muscle development. DNA microarray, real-time quantitative PCR, and quantitative western blot analyses revealed that the amount of MHC in both body-wall and pharyngeal muscle decrease in response to spaceflight. Decreased transcription of the body-wall myogenic transcription factor HLH-1 (CeMyoD) and of the three pharyngeal myogenic transcription factors, PEB-1, CEH-22 and PHA-4 were also observed. Upon return to Earth animals displayed reduced rates of movement, indicating a functional defect. These results demonstrate that C. elegans muscle development is altered in response to spaceflight. This altered development occurs at the level of gene transcription and was observed in the presence of innervation,not simply in isolated cells. This important finding coupled with past observations of decreased levels of the same myogenic transcription factions in vertebrates after spaceflight raises the possibility that altered muscle development is a contributing factor to spaceflight-induced muscle atrophy in vertebrates.
The energetic consequences of dietary specialization in populations of the garter snake, Thamnophis elegans
Authors: Britt E. J. , Hicks J. W. , Bennett A. F. 
Published: August 2006

SUMMARY
We investigated the intraspecific variation in digestive energetics between dietary specialist and generalist populations of the Western Terrestrial garter snake (Thamnophis elegans) in northern California. Coastal populations have a specialized diet of slugs and inland populations have a generalized diet of fish, anurans, mice and leeches. The difference in prey preference between the two populations is congenital, heritable and ontogenetically stable. To examine energetic specializations and trade-offs in these populations, we measured the net assimilation efficiency of each snake population on both slug (Ariolimax columbianus) and fish(Rhinichthys osculus) diets. The net assimilation efficiency was measured during digestion of a meal and continued until metabolic rate re-attained prefeeding levels. Coastal snakes were able to utilize 62% more of the ingested energy towards production from slug diets through both increased assimilation of nutrients and reduced digestive costs. For fish, assimilation and digestive costs were the same in both coastal and inland populations. These results support the hypothesis that snakes with specialized diets can evolve physiological traits to extract nutrients more efficiently. However,there was no apparent trade-off on the more generalized diet that was associated with this specialization.
Exploring with damaged antennae: do crayfish compensate for injuries?
Authors: Koch L. M. , Patullo B. W. , Macmillan D. L. 
Published: August 2006

SUMMARYAppendages are important sources of sensory information for all animals that possess them but they are commonly damaged in nature. We describe how the tactile system of the crayfish Cherax destructor functioned when subjected to the kind of damage found in wild-caught or cultured animals. Touch information was methodically varied by the removal of antennae and chelae. The resulting behaviour was analysed in a T-maze. Crayfish with a single antenna ablated turned toward the intact appendage, however, those with only a partial ablation did not, suggesting that a tactile information threshold exists for normal behaviour. When exposed to the same environment after an antennal ablation but with no prior experience in that terrain,crayfish also turned toward the side of the intact antenna. By contrast, when animals with experience obtained in a previous trial with intact antennae were tested after ablation of one antenna, they did not turn into one arm of the maze more than the other. These two outcomes indicate that behaviour is affected by an interaction between the time at which an injury occurs and an animal's knowledge of the topography, and that an injury may affect learning. We also tested to see if other appendages could provide tactile information to compensate for antennal loss. Input from the chelae did not affect the turning behaviour of crayfish in the maze.
Seasonal modulation of sickness behavior in free-living northwestern song sparrows (Melospiza melodia morphna)
Authors: Owen-Ashley Noah T. , Wingfield John C. 
Published: August 2006

SUMMARYA variety of vertebrate species modulate immune function on a seasonal basis to cope with seasonal energy deficits and competing life-history demands, such as reproduction. Most studies to date have focused upon seasonal variation of cellular and humoral immunity, while neglecting behavioral responses to infection. These behavioral strategies are collectively termed sickness behaviors and are hypothesized to divert energy away from normal activities to combat and overcome infection. Sickness behavior can be triggered experimentally by injecting bacterial lipopolysaccharide (LPS). In this study, we provide the first evidence for seasonal modulation of sickness behavior in a free-living animal. Male song sparrows of western Washington state (Melospiza melodia morphna) are sedentary and territorial year round, except for a brief time during molt. Treatment with LPS decreased territorial aggressive behavior of males in the winter (nonbreeding), but not in the spring (breeding). Subjects were recaptured approx. 25 h after treatment. Recaptured LPS males in the winter lost more body mass than saline-injected controls while LPS males in the spring did not. These data indicate that birds in breeding condition were relatively insensitive to the effects of LPS. On a proximate level, suppression of sickness behavior during breeding is likely mediated by seasonal differences in energy allocation, as wintering sparrows were significantly heavier and had larger subcutaneous fat reserves and lower baseline corticosterone levels than breeding birds. Ultimately, suppression of sickness behavior may represent an allocation strategy to balance current reproductive opportunities with the life-history costs of self-defense.
Hydrogen sulfide mediates hypoxia-induced relaxation of trout urinary bladder smooth muscle
Authors: Dombkowski Ryan A. , Doellman Meredith M. , Head Sally K. , Olson Kenneth R. 
Published: August 2006

SUMMARYHydrogen sulfide (H2S) is a recently identified gasotransmitter that may mediate hypoxic responses in vascular smooth muscle. H2S also appears to be a signaling molecule in mammalian non-vascular smooth muscle, but its existence and function in non-mammalian non-vascular smooth muscle have not been examined. In the present study we examined H2S production and its physiological effects in urinary bladder from steelhead and rainbow trout (Oncorhynchus mykiss) and evaluated the relationship between H2S and hypoxia. H2S was produced by trout bladders, and its production was sensitive to inhibitors of cystathionineβ-synthase and cystathionine γ-lyase. H2S produced a dose-dependent relaxation in unstimulated and carbachol pre-contracted bladders and inhibited spontaneous contractions. Bladders pre-contracted with 80 mmol l-1 KCl were less sensitive to H2S than bladders contracted with either 80 mmol l-1KC2H3O2 (KAc) or carbachol, suggesting that some of the H2S effects are mediated through an ion channel. However, H2S relaxation of bladders was not affected by the potassium channel inhibitors, apamin, charybdotoxin, 4-aminopyridine, and glybenclamide, or by chloride channel/exchange inhibitors 4,4′-Diisothiocyanatostilbene-2,2′-disulfonic acid disodium salt,tamoxifen and glybenclamide, or by the presence or absence of extracellular HCO3-. Inhibitors of neuronal mechanisms, tetrodotoxin,strychnine and N-vanillylnonanamide were likewise ineffective. Hypoxia (aeration with N2) also relaxed bladders, was competitive with H2S for relaxation, and it was equally sensitive to KCl, and unaffected by neuronal blockade or the presence of extracellular HCO3-. Inhibitors of H2S synthesis also inhibited hypoxic relaxation. These experiments suggest that H2S is a phylogenetically ancient gasotransmitter in non-mammalian non-vascular smooth muscle and that it serves as an oxygen sensor/transducer, mediating the effects of hypoxia.
Performance and Clinical Utility of a Commercial von Willebrand Factor Collagen Binding Assay for Laboratory Diagnosis of von Willebrand Disease
Authors: Popov Joanna , Zhukov Olga , Ruden Susan , Zeschmann Terry , Sferruzza Anthony , Sahud Mervyn 
Published: August 2006

Abstract
Background: Von Willebrand disease (VWD) diagnosis and classification usually require a combination of nonspecific and VW-factor (VWF)-specific assays. We evaluated the analytical performance of a commercially available collagen-binding assay (CBA) and its usefulness in conjunction with other assays for laboratory diagnosis of VWD.
Methods: We used a commercial CBA ELISA (Life Technologies) to evaluate 3085 plasma samples. We used standard procedures to perform other assays, including factor VIII activity (FVIII:C), VWF antigen (VWF:Ag), ristocetin cofactor activity, VWF collagen binding capacity (VWF:CB), and VWF multimeric analysis.
Results: CBA intra- and interassay CVs were &lt;6% and &lt;13%, respectively. Reference intervals were 45%–198% for VWF:CB and 0.75–1.32 for the VWF:CB/Ag ratio. Of 3085 samples tested, 235 (8%) had results commonly associated with VWD. Multimer analysis and phenotypic data in 156 samples identified VWD types as: 91 (58%) type 1, 62 (40%) type 2, and 3 (2%) type 3. Of the 91 type 1 samples, proportional decreases in functional activity were seen in 75 samples (82%) according to CBA and in 63 samples (69%) according to the ristocetin cofactor assay. Of the type 2 samples, 10 were further identified as probable type 2A, 26 as probable type 2B, 12 as probable type 2M, and 14 could not be subtyped. VWF:CBA/Ag ratios &lt;0.5 occurred in 83% of VWD type 2A and 2B samples, indicating characteristic functional discordance. Mean (SD) VWF:CB values were significantly higher in individuals without group O blood [113 (45)] than in those with group O blood [83 (32)] (t-test, P = 0.007).
Conclusions: The commercial CBA assay produces reliable results and is useful for laboratory diagnosis of VWD.
Particle wetting distribution in trickle‐bed reactors
Authors: van Houwelingen Arie Jan , Sandrock Carl , Nicol Willie 
Published: August 2006

AbstractA novel technique is used to obtain the distribution of particle wetting in trickle‐bed reactors for different flow and prewetting conditions. Two prewetting methods were investigated: (1) Levec prewetting, in which the packed catalyst bed is completely flooded and then left to drain before steady state trickle‐flow is commenced; (2) Kan prewetting, in which the bed is prewetted by pulsing with the liquid before flow, after which the liquid flow is gradually set back to the required rate. It is shown that the method of prewetting has a major influence on average wetting efficiency and wetting distributions: Average wetting efficiencies differ with as much as 20% between the prewetting modes, and Levec prewetting leads to a considerable fraction of the bed that is not used (up to 7% at the investigated flow conditions), whereas the entire catalyst is used in Kan prewetted beds. It is shown that the particle wetting distributions can influence the modeling of Levec prewetted beds for liquid‐ and gas‐limited conditions. © 2006 American Institute of Chemical Engineers AIChE J, 2006
Histone deacetylase inhibitor FK228 is a potent inducer of human fetal hemoglobin
Authors: Cao Hua , Stamatoyannopoulos George 
Published: August 2006

AbstractWe investigated the induction of the human fetal globin gene using five potent histone deacetylase (HDAC) inhibitors: FK‐228, HC‐Toxin, Trichostatin, MS‐275, and Apicidin, using in vitro assays and cultures of primary human erythroblasts. The results showed that FK228 is the most potent inducer of fetal hemoglobin and exhibits its effects in picomolar concentrations. FK228 should be considered as a potential therapeutic for induction of fetal hemoglobin in patients with β chain hemoglobinopathies. Am. J. Hematol., 2006. © 2006 Wiley‐Liss, Inc.
High‐dose therapy and autologous peripheral blood stem cells transplantation followed by a very low reduced intensity regimen with fludarabine + cyclophosphamide and allograft improve complete remission rate in de novo multiple myeloma patients
Authors: Martino Massimo , Console Giuseppe , Irrera Giuseppe , Praticò Giulia , Stelitano Caterina , Callea Vincenzo , Morabito Fortunato , Quartarone Eugenia , Musolino Caterina , Piro Eugenio , Brugiatelli Maura , Iacopino Pasquale 
Published: August 2006

AbstractThe recent development of reduced intensity conditioning and allotransplantation (RICT) has opened a new way to assure engraftment of donor cells while reducing early transplant‐related mortality. We evaluated the combination of high‐dose therapy and autologous peripheral blood stem cells transplantation (APBSCT) followed by RICT to extend the benefit of allografting procedures in de novo multiple myeloma (MM) patients. Fifteen subjects with stage III MM (median age 51 years, range 40–57) received high dose melphalan (200 mg/m2) followed by APBSCT previously collected after cyclophosphamide (4 g/m2) and granulocyte colony‐stimulating factor (G‐CSF). After 3–4 months from APBSCT, the patients underwent RICT, consisting of fludarabine 30 mg/m2 + cyclophosphamide 300 mg/m2 on days −4, −3, and −2. Acute graft‐versus‐host disease (GVHD) occurred in 2 patients; 6 patients developed chronic GVHD; 4 patients developed CMV antigenemia and were treated pre‐emptively with ganciclovir. No transplant related mortality was shown. Response was simultaneously measured by both electrophoresis (EP) and immunofixation (IF); when IF was negative, patients were classified in complete remission (CR) and when it remained positive, near CR (nCR). After a median follow up of 44 months post APBSCT, 100 and 43% of patients are still alive and progression‐free, respectively. Overall, the CR + nCR rate after dose‐reduced allograft was enhanced from 26.7 to 73.3%. A correlation not statistically significant between GVHD and remission was found. In conclusion, an up‐front tandem strategy with a very low reduced intensity‐conditioning regimen for allografting following autografting is feasible and induces high CR/nCR rate in MM. Am. J. Hematol., 2006. © 2006 Wiley‐Liss, Inc.