bluuebunny/crossref_metadata_2025_split huggingface dataset:
Expressed sequence tag analysis of the diapausing queen of the bumblebee Bombus ignitus
Authors: KIM Yeon‐Ju , HWANG Jae‐Sam , YOON Hyung‐Joo , YUN Eun‐Young , LEE Sang Beom , AHN Mi‐Young , KIM Nam‐Soon , KIM Iksoo , JEON Jae‐Pil , HWANG Seok‐Jo 
Published: November 2006

AbstractWe constructed a full‐length cDNA library from diapausing queens of the bumblebee Bombus ignitus. A total of 480 randomly selected clones was sequenced by single‐run 5′‐end sequencing. Of these, there were 437 high quality clones, 23 poor quality clones and 20 read‐fail clones. Each high quality clone sequence was searched against a public protein database. The most frequently found matching genes were ribosomal proteins (12.5%), p10 (3.58%), cytochrome P450 monooxygenase (3.13%) and sensory appendage protein (2.9%). Sequence similarity analysis between bumblebees and other insect species showed that 72 out of 437 (16.5%) bumblebee expressed sequence tags (EST) matched sequences of Apis mellifera, with matches to Drosophila melanogaster (6.6%), Caenorhabditis briggsae (6.2%), Lysiphlebus testaceipes (4.8%), Periplaneta americana (3.7%) and Anopheles gambiae (3.4%) following, suggesting that sequence similarity of bumblebee EST is closest to that of A. mellifera. Functional classification of EST based on Gene Ontology showed that most genes found by sequencing are associated with physiological processes in the bumblebee. The results of sequencing and analysis of our 437 cDNA demonstrated that high‐throughput EST sequencing and data analysis are powerful means for identifying novel genes and for expression profiling. Our bumblebee EST collection could be a useful platform for further studies of gene expression in diapausing bumblebees.
Characterization of 2-Bromoethanesulfonate as a Selective Inhibitor of the Coenzyme M-Dependent Pathway and Enzymes of Bacterial Aliphatic Epoxide Metabolism
Authors: Boyd Jeffrey M. , Ellsworth Ashley , Ensign Scott A. 
Published: November 2006

ABSTRACT

Bacterial growth with short-chain aliphatic alkenes requires coenzyme M (CoM) (2-mercaptoethanesulfonic acid), which serves as the nucleophile for activation and conversion of epoxide products formed from alkene oxidation to central metabolites. In the present work the CoM analog 2-bromoethanesulfonate (BES) was shown to be a specific inhibitor of propylene-dependent growth of and epoxypropane metabolism by
Xanthobacter autotrophicus
strain Py2. BES (at low [millimolar] concentrations) completely prevented growth with propylene but had no effect on growth with acetone or
n
-propanol. Propylene consumption by cells was largely unaffected by the presence of BES, but epoxypropane accumulated in the medium in a time-dependent fashion with BES present. The addition of BES to cells resulted in time-dependent loss of epoxypropane degradation activity that was restored upon removal of BES and addition of CoM. Exposure of cells to BES resulted in a loss of epoxypropane-dependent CO
2
fixation activity that was restored only upon synthesis of new protein. Addition of BES to cell extracts resulted in an irreversible loss of epoxide carboxylase activity that was restored by addition of purified 2-ketopropyl-CoM carboxylase/oxidoreductase (2-KPCC), the terminal enzyme of epoxide carboxylation, but not by addition of epoxyalkane:CoM transferase or 2-hydroxypropyl-CoM dehydrogenase, the enzymes which catalyze the first two reactions of epoxide carboxylation. Comparative studies of the propylene-oxidizing actinomycete
Rhodococcus rhodochrous
strain B276 showed that BES is an inhibitor of propylene-dependent growth in this organism as well but is not an inhibitor of CoM-independent growth with propane. These results suggest that BES inhibits propylene-dependent growth and epoxide metabolism via irreversible inactivation of the key CO
2
-fixing enzyme 2-KPCC.
Surface Protein IsdC and Sortase B Are Required for Heme-Iron Scavenging ofBacillus anthracis
Authors: Maresso Anthony W. , Chapa Travis J. , Schneewind Olaf 
Published: November 2006

ABSTRACTBacillus anthracis, the spore-forming agent of anthrax, requires iron for growth and is capable of scavenging heme-iron during infection. We show here that theB. anthracis iron-regulatedsurfacedeterminants (isd) locus encompassesisdC, specifying a heme-iron binding surface protein. Anchoring of IsdC to the cell wall envelopes of vegetative bacilli requiressrtB, which encodes sortase B. Purified sortase B cleaves IsdC between the threonine and the glycine of its NPKTG motif sorting signal.B. anthracisvariants lacking eitherisdCorsrtBdisplay defects in heme-iron scavenging, suggesting that IsdC binding to heme-iron in the cell wall envelope contributes to bacterial uptake of heme.
Biosynthetic Pathways of Inositol and Glycerol Phosphodiesters Used by the HyperthermophileArchaeoglobus fulgidusin Stress Adaptation
Authors: Borges Nuno , Gonçalves Luís G. , Rodrigues Marta V. , Siopa Filipa , Ventura Rita , Maycock Christopher , Lamosa Pedro , Santos Helena 
Published: November 2006

ABSTRACTArchaeoglobus fulgidusaccumulates di-myo-inositol phosphate (DIP) and diglycerol phosphate (DGP) in response to heat and osmotic stresses, respectively, and the level of glycero-phospho-myo-inositol (GPI) increases primarily when the two stresses are combined. In this work, the pathways for the biosynthesis of these three compatible solutes were established based on the detection of the relevant enzymatic activities and characterization of the intermediate metabolites by nuclear magnetic resonance analysis. The synthesis of DIP proceeds from glucose-6-phosphate via four steps: (i) glucose-6-phosphate was converted intol-myo-inositol 1-phosphate byl-myo-inositol 1-phosphate synthase; (ii)l-myo-inositol 1-phosphate was activated to CDP-inositol at the expense of CTP; this is the first demonstration of CDP-inositol synthesis in a biological system; (iii) CDP-inositol was coupled withl-myo-inositol 1-phosphate to yield a phosphorylated intermediate, 1,1′-di-myo-inosityl phosphate 3-phosphate (DIPP); (iv) finally, DIPP was dephosphorylated into DIP by the action of a phosphatase. The synthesis of the two other polyol-phosphodiesters, DGP and GPI, proceeds via the condensation of CDP-glycerol with the respective phosphorylated polyol, glycerol 3-phosphate for DGP andl-myo-inositol 1-phosphate for GPI, yielding the respective phosphorylated intermediates, 1X,1′X-diglyceryl phosphate 3-phosphate (DGPP) and 1-(1X-glyceryl)myo-inosityl phosphate 3-phosphate (GPIP), which are subsequently dephosphorylated to form the final products. The results disclosed here represent an important step toward the elucidation of the regulatory mechanisms underlying the differential accumulation of these compounds in response to heat and osmotic stresses.
Maximum effort breath-hold times for males and females of similar pulmonary capacities during sudden face-only immersion at water temperatures from 0 to 33 °C
Authors: Jay Ollie , White Matthew D. 
Published: November 2006

For non breath-hold-trained males and females matched for pulmonary capacity and body size, the effects of sex, water temperature, and end-tidal gas tensions were studied for their potential influences on breath-holding ability. Maximum breath-hold time (BHTmax) was measured a total of 546 times in 13 males and 13 females, each repeating 3 trials of sudden face immersion (i.e., no prior hyperventilation) in water at 0, 5, 10, 15, 20, and 33 °C and in an air control condition (AIR). End-tidal carbon dioxide (PETCO2) and oxygen (PETO2) gas tensions were measured before and after breath-holding in a subset of 11 males and 11 females. For BHTmax there was no main effect of sex (p = 0.20), but there was a main effect of immersion condition (p < 0.001). Relative to pre-immersion rest values, end-tidal gas tensions were significantly higher in males than in females (p ≤ 0.05) and significantly lower at decreased water temperatures relative to AIR (p ≤ 0.05). In conclusion, for these matched groups (i) sex did not influence BHTmax; (ii) irrespective of sex, decreases in water temperature at 0, 5, 10, and 15 °C gave proportionate decreases of BHTmax; (iii) significantly greater deviations in both PETCO2 and PETO2 following breath-holding were evident in males relative to females; and (iv) irrespective of sex, there were significantly smaller changes in both PETCO2 and PETO2 at lower water temperatures relative to AIR, with or without removing the variance due to breath holding.
Chronic Protein Kinase B (PKB/c-akt) Activation Leads to Apoptosis Induced by Oxidative Stress–Mediated Foxo3a Transcriptional Up-regulation
Authors: van Gorp Ankie G.M. , Pomeranz Karen M. , Birkenkamp Kim U. , Hui Rosaline C-Y. , Lam Eric W-F. , Coffer Paul J. 
Published: November 2006

Abstract
Increased protein kinase B (PKB; c-Akt) activation is a hallmark of diverse neoplasias providing both proliferative and antiapoptotic survival signals. In this study, we investigated the effect of chronic PKB activation on cellular survival and proliferation using cytokine-dependent bone marrow–derived Ba/F3 cells, in which PKBα activation can be directly, and specifically, induced by addition of 4-hydroxytamoxifen (4-OHT). Direct activation of PKB rescued Ba/F3 cells from cytokine withdrawal–induced apoptosis; however, surprisingly, these antiapoptotic effects were short lived, cells only being protected for up to 48 hours. We observed that activation of PKB in survival factor–deprived cells led to a dramatic increase of Foxo3a on both the transcriptional and protein level leading to expression of its transcriptional targets Bim and p27kip1. High levels of PKB activity result in increased aerobic glycolysis and mitochondrial activity resulting in overproduction of reactive oxygen species. To determine whether oxidative stress might itself be responsible for Foxo3a up-regulation, we utilized hydrogen peroxide (H2O2) as an artificial inducer of oxidative stress and N-acetylcysteine (NAC), a thiol-containing radical oxygen scavenger. Addition of NAC to the culture medium prolonged the life span of cells treated with 4-OHT and prevented the up-regulation of Foxo3a protein levels caused by PKB activation. Conversely, treatment of Ba/F3 cells with H2O2 caused an increase of Foxo3a on both transcriptional and protein levels, suggesting that deregulated PKB activation leads to oxidative stress resulting in Foxo3a up-regulation and subsequently cell death. Taken together, our data provide novel insights into the molecular consequences of uncontrolled PKB activation. (Cancer Res 2006; 66(22): 10760-9)
Persistent Human Papillomavirus Infection Is Associated with a Generalized Decrease in Immune Responsiveness in Older Women
Authors: García-Piñeres Alfonso J. , Hildesheim Allan , Herrero Rolando , Trivett Matthew , Williams Marcus , Atmetlla Ivannia , Ramírez Margarita , Villegas Maricela , Schiffman Mark , Rodríguez Ana Cecilia , Burk Robert D. , Hildesheim Mariana , Freer Enrique , Bonilla José , Bratti Concepción , Berzofsky Jay A. , Pinto Ligia A. 
Published: November 2006

Abstract
The development of cervical cancer and its precursors are linked to persistent infection with oncogenic types of human papillomavirus (HPV). Host immune responses seem to be determinants of risk for this disease. However, little is known about the immunologic determinants of HPV persistence. Here, we examined the association between lymphoproliferative responses to antigens/mitogens and persistent HPV infection in women older than 45 years. Women included in this study were participants in a 10,000-woman population-based cohort study of cervical neoplasia in Costa Rica. Women older than 45 years and HPV DNA positive at a screening visit were selected as cases (n = 283). We selected a comparably sized control group of HPV DNA–negative women, matched to cases on age and time since enrollment (n = 261). At an additional clinical visit, women were cytologically and virologically rescreened, and cervical and blood specimens were collected. Proliferative responses to phytohemagglutinin (PHA), influenza virus (Flu), and HPV16 virus-like particle (VLP) were lower among women with persistent HPV infection [median counts per minute (cpm): 72,849 for PHA, 1,241 for Flu, and 727 for VLP] than for the control group (median cpm: 107,049 for PHA, 2,111 for Flu, and 2,068 for VLP). The decreases were most profound in women with long-term persistence and were only observed for the oldest age group (≥65 years). Our results indicate that an impairment in host immunologic responses is associated to persistent HPV infection. The fact that effects were evident for all studied stimuli is suggestive of a generalized effect. (Cancer Res 2006; 66(22): 11070-6)
Infrared study of goethites of varying crystallinity and particle size: II. Crystallographic and morphological changes in series of synthetic goethites
Authors: Cambier P. 
Published: November 2006

AbstractLow crystallinity of unsubstituted goethites is characterized by a small coherently diffracting domain, which may be accompanied by another type of disorder revealed by broader IR half-absorbance band widths. Inside the unit cell, the H-bond is weaker, which increases the OH stretching frequency and lowers the bending frequencies. Also, an increase in parameter a and a change in Fe-O bonds, which might correspond to a minor tilting of octahedra, occur along with a lowering of the frequency of the 630 cm−1 band.
Diagenetic peculiarities of potential Lower Jurassic reservoir sandstones, Troms 1 area, Off Northern Norway, and their tectonic significance
Authors: Riches P. , Traub-Sobott I. , Zimmerle W. , Zinkernagel U. 
Published: November 2006

AbstractIn the Troms 1 area, sediments of Early to Middle Jurassic age, ranging from alluvial plain deposits at the base, passing through coastal plain/tidal flat sediments up into high-energy nearshore shallow-marine sands, mark a transgression. The sandstones, classified as mineralogically and texturally mature quartz-arenites, are potential reservoir rocks in the eastern part of the area. The apparent supermaturity, however, is of secondary origin because unstable detrital components were dissolved during diagenesis. The succession of complex diagenetic processes was: (i) mechanical compaction and simultaneous pressure solution, (ii) partial dissolution with corrosion of detrital quartz and dissolution of unstable fragments, (iii) silica cementation, (iv) calcite cementation, (v) partial carbonate dissolution, (vi) kaolinite/Fe-carbonate cementation in the remaining pore space. Porosity and permeability of the sandstones are controlled by the degree of silicification and by dissolution processes. Two dissolution stages led to partial ‘skeletonization’ of the detrital framework and to elimination of unstable detrital grains. The first stage was a basic process leading to corrosion of detrital quartz and creating transitory secondary porosity; the second stage was acidic leading to the present preserved secondary porosity. Diagenetic dissolution channels formed. The degree of diagenetic alteration was much higher than normally observed in sandstones of such burial depth. Hydrothermal solutions rising from deep-seated faults may have led to this unusual alteration and triggered a rift-related type of complex diagenesis.
Thermodynamic and structural aspects of the dehydration of smectites in sedimentary rocks
Authors: Hall P. L. , Astill D. M. , McConnell J. D. C. 
Published: November 2006

AbstractThe diagenetic conversion of smectite to illite in shales has been proposed as a mechanism for generating overpressure (fluid pressure above hydrostatic) in sedimentary basins. However, the mechanism and rate-controlling factors of the reaction and the magnitude of the resulting volume change are not known. In this paper the thermodynamics of the reversible hydration/dehydration of smectite are analysed in the pressure/temperature regime of sedimentary rocks. If the interlamellar water is more dense than bulk water, and the pressures on the solid and fluid phases are equal, the dehydration temperature should increase with increasing confining pressureviathe Clapeyron-Clausius equation. However, either fluid pressures below the pressure on the solid matrix or high pore-fluid salinities can reduce the dehydration temperature. Experiments on Ca2+-montmorillonite compacted in the presence of distilled water in a steel autoclave fitted with a sensitive pressure transducer failed to detect any overall volume change due to dehydration up to 185°C and 1400 bar. This finding, which is consistent with recent high-pressure DTA and XRD studies on Na+-montmorillonite, suggests that reversible loss of the last two water layers does not occur in sedimentary basins except as part of the more complex diagenetic conversion of smectite to illite. Some recent evidence from high-resolution TEM and microprobe analyses regarding the mechanism of the reaction is also discussed.
Formation damage and remedial stimulation
Authors: Harper T. R. , Buller D. C. 
Published: November 2006

AbstractIt is argued that a wide range of engineering data and geological data is required to make confident prognoses or diagnoses of formation damage. Potential sources of data are reviewed, with comments on their limitations. It is proposed that microscopic failure can cause formation damage in macroscopically intact rock at stress concentrations around the wellbore. The significance of natural fractures is reviewed in relation to formation damage induced by diagenetic mineralization or invasion by lost circulation material. Removal of such plugging material by acid stimulation is assessed in relation to diverting agent requirements.
Structure of poorly-ordered aluminosilicates
Authors: Wilson M. A. , McCarthy S. A. , Fredericks P. M. 
Published: November 2006

AbstractThe structure of synthetic aluminosilicates prepared at pH 6 has been investigated by 29Si and 27Al high-resolution solid-state nuclear magnetic resonance (NMR) spectroscopy. Fourier transform infrared (FTIR) spectroscopy and electron microscopy have also been used to characterize the products. The amount of Si and Al in protoimogolite, disordered allophane and other structures has been measured. There is a fair correlation between the intensity of the 349 cm−1 band in the FTIR spectra and the proportion by weight of protoimogolite Si measured by NMR. It is shown that disordered allophanes have similar structures to those proposed by van Reeuwijk and de Villiers (Soil Sci. Soc. Am. Proc. 32 (1968) 238–240), i.e. octahedral Al surrounding a tetrahedral core. Moreover, it is clear that at high Al:Si ratios (⩾1:1), protoimogolite can compete with disordered allophane precursors for aluminum. The driving forces for formation of protoimogolite rather than allophane appear to be long range Al-Al repulsive forces through oxygen.
Exposure to trichloramine and respiratory symptoms in indoor swimming pool workers
Authors: Jacobs J. H. , Spaan S. , van Rooy G. B. G. J. , Meliefste C. , Zaat V. A. C. , Rooyackers J. M. , Heederik D. 
Published: November 2006

The association between swimming pool characteristics and activities of employees and respiratory symptoms in employees was studied. Trichloramine levels were measured to evaluate relationships with pool characteristics and to estimate long-term exposure levels.Questionnaires were available from 624 pool workers and 38 swimming facilities. Chloramine levels were measured by area sampling over 2-h periods and analysed using ion chromatography. Work-related and general respiratory symptoms, and symptoms indicative of atopy and bronchial hyperresponsiveness were considered. Respiratory symptom prevalence among pool workers was compared with symptoms in a Dutch population sample. Chloramine levels were modelled with regression analysis. This model was used to estimate long-term average chloramine levels for each pool studied.Employees with higher exposure reported upper respiratory symptoms with greater frequency. Upper respiratory symptoms were statistically significantly associated with cumulative chloramine levels (odds ratio (OR) >1.4 for hoarseness, lost voice, sinusitis). General respiratory symptoms were significantly elevated compared with a Dutch population sample (OR ranged 1.4–7.2).An excess risk for respiratory symptoms indicative of asthma was observed in swimming pool employees. Aggravation of existing respiratory disease or interactions between irritants and allergen exposures are the most likely explanations for the observed associations.
The 6-min walking distance: long-term follow up in patients with COPD
Authors: Casanova C. , Cote C. G. , Marin J. M. , de Torres J. P. , Aguirre-Jaime A. , Mendez R. , Dordelly L. , Celli B. R. 
Published: November 2006

The 6-min walking distance (6MWD) test is used in clinical practice and research into patients with chronic obstructive pulmonary disease (COPD). However, little is known about natural long-term change in this parameter.The 6MWD was measured at baseline and then annually for 5 yrs in 294 patients with COPD and its annual rate of decline was determined. Forced expiratory volume in one second (FEV1) was also measured and the relationship between changes in both markers was explored.At baseline, the median 6MWD was 380 m (range 160–600 m). It declined by 19% (16 m·yr-1) over the 5 yrs compared with baseline in patients with American Thoracic Society/European Respiratory Society stage III COPD (FEV130–50% predicted) and by 26% (15 m·yr-1) in patients with stage IV COPD (FEV1<30% pred). Over the 5-yr follow-up, the proportion of patients with a minimal clinically significant decline of 54 m increased with the severity of the disease. It was 24% in stage II, 45% in stage III, and 63% in stage IV disease. In contrast, the rate of decline of FEV1was greater in patients with milder airflow obstruction and lesser in patients with lower absolute FEV1values.In conclusion, the 6-min walking distance test provides increasingly useful information as the severity of chronic obstructive pulmonary disease increases.
Dendritic cell recruitment in lesions of human and experimental pulmonary hypertension
Authors: Perros F. , Dorfmüller P. , Souza R. , Durand-Gasselin I. , Mussot S. , Mazmanian M. , Hervé P. , Emilie D. , Simonneau G. , Humbert M. 
Published: November 2006

In the present study, the hypothesis that dendritic cells (DCs), key players in immunity and tolerance, might be involved in the immunopathology of idiopathic pulmonary arterial hypertension (IPAH) was tested.The phenotype and localisation of DCs were characterised by immunohistochemistry and double-labelling immunofluorescence in lung samples from controls, human IPAH patients and an experimental pulmonary hypertension model (monocrotaline-exposed rats).As compared with controls, morphometric analysis demonstrated increased numbers of dendritic cell-specific intercellular adhesion molecule-grabbing nonintegrin (DC-SIGN)-positive cells in muscular pulmonary arteries in IPAH and OX-62-positive DCs in monocrotaline-induced pulmonary hypertension. In human samples, the mean±semnumber of DC-SIGN-positive cells·artery−1of 100–300 μm diameter was 1.4±0.4 in controlsversus26.4±2.7 in IPAH. In rats, the number of OX-62-positive cells·artery−1of 50–150 μm diameter was 0.5±0.2 in controls, and 0.7±0.5, 3.1±0.5 and 8.4±0.6 at day 7, 14 and 28 after monocrotaline exposure, respectively. Human complex lesions of muscular pulmonary arteries showed transmural DC infiltration. Phenotyping revealed an immature DC profile in human and experimental pulmonary hypertension.The results support the concept that immature dendritic cells accumulate in remodelled pulmonary vessels and hence could be involved in the immunopathology of pulmonary hypertension.