bluuebunny/crossref_metadata_2025_split huggingface dataset:
Expression of activin and inhibin subunits, receptors and binding proteins in human pheochromocytomas: a study based on mRNA analysis and immunohistochemistry
Authors: Hofland J. , Van Nederveen F. H. , Timmerman M. A. , Korpershoek E. , De Herder W. W. , Lenders J. W. , Verhofstad A. A. , De Krijger R. R. , De Jong F. H. 
Published: February 2007

SummaryObjective  Pheochromocytomas are uncommon tumours arising from chromaffin cells of the adrenal medulla and related paraganglia. So far, one of the few reported markers to discriminate malignant from benign tumours is the βB‐subunit of inhibin and activin, members of the transforming growth factor (TGF)‐β superfamily of growth and differentiation factors.Design  We investigated the expression of the mRNAs coding for activin and inhibin subunits, their receptors and binding proteins by quantitative reverse transcriptase‐polymerase chain reaction (RT‐PCR) and studied the presence of the inhibin βB‐subunit in human pheochromocytomas by immunohistochemistry.Patients  Samples from resected pheochromocytomas of patients operated between 1973 and 2003 were used for experiments.Results  The immunohistochemical investigations revealed that staining of the inhibin βB‐subunit was positive in 12 of 36 (33%) benign and 5 of 34 (15%) malignant pheochromocytomas (P > 0·05). Therefore, it was not possible to discriminate between benign and malignant tumours solely on the basis of inhibin βB‐subunit immunohistochemistry. Quantitative real‐time RT‐PCR in nine benign and four malignant tumours showed expression of inhibin α‐, βA‐ and βB‐subunits, the activin receptors Alk‐4, ActRIIA, and ActRIIB, and the inhibin‐ and activin‐binding proteins betaglycan and follistatin in all samples. No correlations were detected between individually coupled expression of mRNAs of these activin‐ and inhibin‐related genes in the 13 pheochromocytomas. Only inhibin βA‐subunit expression was different in malignant compared to benign pheochromocytomas (P = 0·020).Conclusions  No clear role for activin and inhibin was found in discriminating between benign and malignant pheochromocytomas.
Gender differences in plasma ghrelin and its relations to body composition and bone – an opposite‐sex twin study
Authors: Makovey Joanna , Naganathan Vasi , Seibel Markus , Sambrook Philip 
Published: February 2007

SummaryBackground  Ghrelin, a peptide hormone that plays a role in the regulation of appetite and body adiposity, may also play a role in bone metabolism.Objectives  We used the opposite‐sex twin model to study associations of plasma ghrelin levels with measures of bone mass and body composition, and determine how such associations were influenced by gender and age.Patients and measurements  We measured total plasma ghrelin by radioimmunoassay (RIA) and bone mass/body composition parameters by dual energy X‐ray absorptiometry in 79 pairs of opposite sex twins (n = 158 subjects). To examine the effect of age, the study population was divided by median age into two groups: under 51·2 years (38 pairs) and over 51·2 years (41 pairs).Results  Women had higher plasma ghrelin levels than men (median 1063 vs. 869 ng/l, P < 0·01). Age was a significant predictor of plasma ghrelin levels after adjustment for gender, fat mass and body size. In the older age group, plasma ghrelin levels were inversely associated with fat mass measures in men and women, but there were gender differences in the nature of these associations. In women, plasma ghrelin correlated inversely with body mass index (BMI, r = −0·32), total fat mass (r = −0·30) and fat mass/lean mass ratio (r = −0·42), whereas in men associations with abdominal fat mass (r = −0·31) and fat distribution index (r = −0·33) were observed. Plasma ghrelin was associated with alcohol consumption in older men and women. In the obese subgroup (BMI > 30) no significant gender differences in plasma ghrelin were found. Plasma ghrelin levels were not significantly associated with bone mineral density (BMD) generally, except for hip BMD in younger women (r = −0·39).Conclusion  Plasma ghrelin levels are associated with age, gender, alcohol intake and fat mass measures but only weakly to bone mass measures.
Well‐being, health‐related quality of life and cardiovascular disease risk profile in women with subclinical thyroid disease – a community‐based study
Authors: Bell Robin J. , Rivera‐Woll Livia , Davison Sonia L. , Topliss Duncan J. , Donath Susan , Davis Susan R. 
Published: February 2007

SummaryObjectives  The aim of this study was to evaluate whether subclinical thyroid disease is associated with impaired health‐related quality of life and a more adverse cardiovascular disease risk profile.Design  A community‐based cross‐sectional study.Setting and participants  A total of 1423 non‐healthcare‐seeking women, aged 18–75 years were randomly recruited from the community via the electoral roll from April 2002 to August 2003.Main outcome measures  These were the scores for the Short‐Form 36 (SF‐36), the Psychological General Well‐being Index (PGWI), thyroid hormone levels, serum lipids and high sensitivity C‐reactive protein (hsCRP). Subclinical hypothyroidism (SCH) and subclinical hyperthyroidism (SCHyper) were defined as serum TSH > 4·0 mIU/l and < 0·5 mIU/l, respectively, with a normal free thyroxine (free T4) level.Results  Evaluable data were available for all participants. 10·7% of all women had an abnormal TSH value. The prevalence of a low TSH level by age group ranged from 1·2% to 6·4%, whereas the prevalence of an elevated TSH level ranged from 2·8% to 9·2% and increased with age (P = 0·002). There were no significant differences between women with SCH or SCHyper and age‐matched controls for the total PGWI score or the Mental and Physical Component Scores of the SF‐36. Women with SCH were no different from controls for serum lipids or hsCRP. Using linear regression, SCH vs. euthyroidism did not make an independent contribution to variation in either total cholesterol or triglycerides, with or without adjustment for age ± age2 ± BMI.Conclusions  Our data indicate that subclinical thyroid disease in women in the community is not associated with lower well‐being or impaired health‐related quality of life and SCH is not associated with increased serum markers of CVD risk.
Range size in North AmericanEnallagmadamselflies correlates with wing size
Authors: RUNDLE SIMON D. , BILTON DAVID T. , ABBOTT JOHN C. , FOGGO ANDREW 
Published: February 2007

Summary1. Cross‐species macroecological comparisons in freshwater invertebrates have been restricted by a lack of large‐scale distributional data, and robust phylogenies. Here, we use data from theOdonataCentraldatabase to explore body length–range size and wing length–range size relationships in damselflies from the genusEnallagma; the recent publication of a phylogeny for this group meant that, as well as a cross‐species analysis, we were able to assess relationships in a phylogenetically controlled manner.2. For cross‐species comparisons, only wing length showed significant (positive) regression relationships with range size and occupancy, although the inclusion of body length in multiple regressions increased the fit of the models. Damselflies with larger wings relative to their body length had larger distributions, a result confirmed by a significant positive relationship between range size and residuals from the regression of wing size on body size.3. For the phylogenetically controlled analyses, only wing length contrast scores were significantly related to distribution patterns and entered into regression models; the significant positive relationships between wing length contrasts and both range size and occupancy contrasts suggested that evolutionary increases in wing length had occurred alongside range expansions.4. Together these results suggest that species ofEnallagmawith larger wings (both absolute and relative to body length) tend to be more widely distributed in North America and that the evolution of wing size may have played a role in range expansion. No such relationships were evident for body size. We discuss the potential importance of wing morphometrics for studying the evolutionary ecology of freshwater insects.
The stress sensitivity of shaley sandstones
Authors: MacBeth Colin , Ribeiro Christophe 
Published: February 2007

ABSTRACTThe link between the stress sensitivity of shaley sandstones and their porosity and clay content is investigated. This is achieved by firstly fitting a compliance‐based stress‐sensitivity law to laboratory measurements of ultrasonic velocity taken from four sets of reservoir sandstones, extracted from a variety of depositional settings. Correlations are then sought between the independent parameters of this law and the porosity or clay fraction of the rocks, which are then subsequently interpreted in terms of framework or pore‐space‐related microstructural clay models. The general conclusion drawn from the results is that both of the parameters defining the stress‐sensitivity law (the asymptotic modulus and the stress‐dependent excess compliance) clearly vary with porosity. However, only the asymptotic modulus shows a convincing trend with clay and there is little observed variation of the stress‐dependent compliance with clay. There is therefore a resultant variation of stress sensitivity with clay, but it is controlled only by the asymptotic modulus. The analysis also concludes that all four data sets fall into a framework‐related category of clay model.
Estimation of the apertures of water‐saturated fractures by nuclear magnetic resonance well logging
Authors: Nakashima Yoshito , Kikuchi Tsuneo 
Published: February 2007

ABSTRACTFracture aperture is an important transport property in subsurface hydrology because it influences well productivity and the volume of the water resource. Nuclear magnetic resonance (NMR) well logging measures the hydrogen‐bearing fluid molecules in porous or fractured strata, and the NMR signal intensity increases with the amount of fluid in the sensed region of the NMR sonde. Fluid confined in a large fracture of >>0.2 mm in aperture has T2 (i.e. spin‐spin relaxation time) values as long as those of the bulk fluid. The bulk‐fluid porosity (i.e. porosity calculated using this long T2 component in a T2 histogram data) increases linearly with aperture. Therefore, NMR logging enables quantitative estimation of fracture apertures of >>0.2 mm using the bulk‐fluid porosity data if the calibration of the NMR sonde is performed adequately. We applied NMR logging to a borehole in a Holocene andesite lava at Sumikawa, Japan, to estimate the aperture of open fractures within the lava. A test well of 100 m depth and 20 cm diameter, filled with bentonite drilling mud, was scanned with an NMR sonde to obtain a profile of the porosity and the T2 histogram of the andesite. The bulk‐fluid porosity was calculated from the T2 histogram data, as the porosity at which the T2 value is larger than or equal to a threshold T2 of bulk bentonite mud. The bulk‐fluid porosity of a specific inclined fracture responsible for the total loss of circulation at 61.2 m depth during drilling was calculated assuming a threshold or T2 cut‐off of 33 ms, and again for a cut‐off of 100 ms. Calibration of the NMR sensor in a laboratory and measurement of the fracture dip angle by electrical microimaging logging enabled us to estimate the fracture aperture as 1.7 cm, assuming a T2 cut‐off of 33 ms, or 1.6 cm for a T2 cut‐off of 100 ms. The method of aperture determination described in this study is independent of fluid species and lithology, and is applicable to various hydrogen‐bearing borehole fluids (clean water, mud and oil) and geological settings.
Numerical study of seismic scattering and waveguide excitation in faulted coal seams
Authors: Greenhalgh S.A. , Zhou B. , Pant D.R. , Green A. 
Published: February 2007

ABSTRACTFinite‐difference P‐SV simulations of seismic scattering characteristics of faulted coal‐seam models have been undertaken for near‐surface P‐ and S‐wave sources in an attempt to understand the efficiency of body‐wave to channel‐wave mode conversion and how it depends on the elastic parameters of the structure. The synthetic seismograms clearly show the groups of channel waves generated at the fault: one by the downgoing P‐wave and the other by the downgoing S‐wave. These modes travel horizontally in the seam at velocities less than the S‐wavespeed of the rock. A strong Airy phase is generated for the fundamental mode.The velocity contrast between the coal and the host rock is a more important parameter than the density contrast in controlling the amplitude of the channel waves. The optimal coupling from body‐wave energy to channel‐wave energy occurs at a velocity contrast of 1.5. Strong guided waves are produced by the incident S‐sources for source angles of 75° to 90° (close to the near‐side face of the fault). As the fault throw increases, the amplitude of the channel wave also increases. The presence of a lower‐velocity clay layer within the coal‐seam sequence affects the waveguiding characteristics. The displacement amplitude distribution is shifted more towards the lower‐wavespeed layer. The presence of a ‘washout’ zone or a brecciated zone surrounding the fault also results in greater forward scattering and channel‐wave capture by the coal seam.
3D magnetotelluric modelling including surface topography
Authors: Nam Myung Jin , Kim Hee Joon , Song Yoonho , Lee Tae Jong , Son Jeong‐Sul , Suh Jung Hee 
Published: February 2007

ABSTRACTAn edge finite‐element method has been applied to compute magnetotelluric (MT) responses to three‐dimensional (3D) earth topography. The finite‐element algorithm uses a single edge shape function at each edge of hexahedral elements, guaranteeing the continuity of the tangential electric field while conserving the continuity of magnetic flux at boundaries. We solve the resulting system of equations using the biconjugate gradient method with a Jacobian preconditioner. The solution gives electric fields parallel to the slope of a surface relief that is often encountered in MT surveys. The algorithm is successfully verified by comparison with other numerical solutions for a 3D‐2 model for comparison of modelling methods for EM induction and a ridge model. We use a 3D trapezoidal‐hill model to investigate 3D topographic effects, which are caused mainly by galvanic effects, not only in the Zxy mode but also in the Zyx mode. If a 3D topography were approximated by a two‐dimensional topography therefore errors occurring in the transverse electric mode would be more serious than those in the transverse magnetic mode.
Candida albicans and filtrates interfere with human spermatozoal motility and alter the ultrastructure of spermatozoa: an in vitro study
Authors: Tian Yong‐Hong , Xiong Jin‐Wen , Hu Lian , Huang Dong‐Hui , Xiong Cheng‐Liang 
Published: February 2007

SummaryThe in vitro effects of Candida albicans and its filtrates on the motility and ultrastructure of human spermatozoa from healthy donors were studied. A significant reduction in sperm progressive motility and signs of membrane alteration, directly related to contact time were observed. Distinct adhesion of spermatozoa to C. albicans and agglutination were observed. Light and transmission electron microscopy examinations showed that spermatozoa attached to C. albicans mainly via the head. Multiple ultrastructural lesions were present, which were the possible morphological reasons for spermatozoan immobilization observed in the present study. It is concluded that C. albicans as well as its filtrates had an inhibitory effect on human sperm motility and impaired the ultrastructure of human spermatozoa, which could be associated with male infertility.
Changes in the expression of P‐cadherin in the normal, cryptorchid and busulphan‐treated rat testis
Authors: Pospechova K. , Kopecky M. , Nachtigal P. , Pospisilova N. , Jamborova G. , Semecky V. 
Published: February 2007

SummaryAdhesion between Sertoli cells and germ cells is important for spermatogenesis. Cadherins are Ca2+‐dependent transmembrane proteins that mediate cell–cell adhesion. The aim of this study was to compare the expression of P‐cadherin in unilaterally cryptorchid and busulphan‐treated rat testes using immunohistochemistry. The pattern of expression of P‐cadherin in the seminiferous epithelium changed with the stage of the seminiferous epithelium. The membranes of round spermatids and membranes and cytoplasm of spermatocytes were strongly positive. Our experiments revealed that busulphan treatment (2 doses – 10 mg/kg of body weight – 21 days apart) and cryptorchism led to destructive changes in the structure of seminiferous tubules, together with the decrease in P‐cadherin expression. The expression of P‐cadherin disappeared in the spermatids segregated from the epithelium while segregated spermatocytes remained still positive for P‐cadherin during the 3‐ to 11‐day cryptorchid period. In busulphan‐treated animals, the expression of P‐cadherin was dependent on the presence or absence of the spermatocytes and spermatids in the tubules. Strong positivity for P‐cadherin was observed in the spermatocytes that re‐appeared in the regenerating seminiferous epithelium. We suggest that P‐cadherin participates in the architecture of adherens junctions in testis, plays an important role in maintaining normal spermatogenesis and that cryptorchism and busulphan treatment lead to adherens junction disintegration.
Paternal occupation and neural tube defects: a case–control study based on the Oxford Record Linkage Study register
Authors: Fear Nicola T. , Hey Kate , Vincent Tim , Murphy Michael 
Published: February 2007

SummaryCertain paternal occupations and related exposures have been suggested as possible risk factors for neural tube defects (NTD). We analysed data collected as part of a case–control study to investigate the relationship between paternal occupational exposures and NTD. Cases were 694 NTD‐affected pregnancies diagnosed between 1970 and 1987 in Oxfordshire or West Berkshire, England. Controls were randomly selected from a computerised maternity database individually matched to cases on maternal year of birth and year of index pregnancy. Data on paternal occupation were abstracted from hospital antenatal records. Associations between paternal occupational exposures and NTD were assessed using odds ratios adjusted for maternal year of birth, year of index pregnancy, gender of baby, multiplicity of birth and number of previous obstetric events.Statistically significant positive associations were observed for paternal occupational exposure to agrochemicals and animals. Analysis by occupational title revealed that more case than control fathers were farmers, gardeners and butchers. Statistically significant negative associations were seen for paternal occupational exposure to inhaled hydrocarbons and metal‐working oil mists. The findings from this population‐based study for paternal agricultural and animal‐related occupations overlap and have been previously observed. The apparent protective effects of fathers working with inhaled hydrocarbons and metal‐working oil mists have not been previously described. No underlying biological mechanisms have been identified, therefore other explanations cannot be excluded.
Review: secular tectonic evolution of Archean continental crust: interplay between horizontal and vertical processes in the formation of the Pilbara Craton, Australia
Authors: Van Kranendonk Martin J. , Hugh Smithies R. , Hickman Arthur H. , Champion D.C. 
Published: February 2007

AbstractThe Archean Pilbara Craton contains five geologically distinct terranes – the East Pilbara, Karratha, Sholl, Regal and Kurrana Terranes – all of which are unconformably overlain by the 3.02‐ to 2.93‐Ga De Grey Superbasin. The 3.53–3.17 Ga East Pilbara Terrane (EP) represents the ancient nucleus of the craton that formed through three distinct mantle plume events at 3.53–3.43, 3.35–3.29 and 3.27–3.24 Ga. Each plume event resulted in eruption of thick dominantly basaltic volcanic successions on older crust to 3.72 Ga, and melting of crust to generate first tonalite‐trondhjemite‐granodiorite (TTG), and then progressively more evolved granitic magmas. In each case, plume magmatism was accompanied by uplift and crustal extension. The combination of conductive heating from below, thermal blanketing from above, and internal heating of buried granitoids during these events led to episodes of partial convective overturn of upper and middle crust. These mantle melting events caused severe depletion of the subcontinental lithospheric mantle, making the EP a stable, buoyant, unsubductable continent by c. 3.2 Ga. Extension accompanying the latest event led to rifting of the protocontinent margins at between 3.2 and 3.17 Ga. After 3.2 Ga, horizontal tectonic forces dominated over vertical forces, as revealed by the geology of the three terranes (Karratha, Sholl and Regal) of the West Pilbara Superterrane. The c. 3.12‐Ga Whundo Group of the Sholl Terrane is a fault bounded, 10‐km‐thick volcanic succession with geochemical characteristics of modern oceanic arcs (including boninites and evidence for flux melting) that indicate steep Archean subduction. At 3.07 Ga, the 3.12‐Ga Sholl Terrane, 3.27‐Ga Karratha Terrane and c. 3.2‐Ga Regal Terrane accreted together and onto the EP during the Prinsep Orogeny. This was followed by development of the De Grey Superbasin – an intracontinental sag basin and widespread plutonism (2.99–2.93 Ga) as a result of orogenic relaxation and slab break off. Craton‐wide compressional deformation at 2.95–2.93 Ga culminated with 2.91‐Ga accretion of the 3.18 Ga Kurrana Terrane with the EP. This compression caused amplification of the dome‐and‐keel structure in the EP. Final cratonization was effected by emplacement of 2.89–2.83 Ga post‐tectonic granites.
Identification of an arsenic tolerant double mutant with a thiol‐mediated component and increased arsenic tolerance in phyA mutants
Authors: Sung Dong‐Yul , Lee David , Harris Hugh , Raab Andrea , Feldmann Jörg , Meharg Andrew , Kumabe Bryan , Komives Elizabeth A. , Schroeder Julian I. 
Published: February 2007

SummaryA genetic screen was performed to isolate mutants showing increased arsenic tolerance using an Arabidopsis thaliana population of activation tagged lines. The most arsenic‐resistant mutant shows increased arsenate and arsenite tolerance. Genetic analyses of the mutant indicate that the mutant contains two loci that contribute to arsenic tolerance, designated ars4 and ars5. The ars4ars5 double mutant contains a single T‐DNA insertion, ars4, which co‐segregates with arsenic tolerance and is inserted in the Phytochrome A (PHYA) gene, strongly reducing the expression of PHYA. When grown under far‐red light conditions ars4ars5 shows the same elongated hypocotyl phenotype as the previously described strong phyA‐211 allele. Three independent phyA alleles, ars4, phyA‐211 and a new T‐DNA insertion allele (phyA‐t) show increased tolerance to arsenate, although to a lesser degree than the ars4ars5 double mutant. Analyses of the ars5 single mutant show that ars5 exhibits stronger arsenic tolerance than ars4, and that ars5 is not linked to ars4. Arsenic tolerance assays with phyB‐9 and phot1/phot2 mutants show that these photoreceptor mutants do not exhibit phyA‐like arsenic tolerance. Fluorescence HPLC analyses show that elevated levels of phytochelatins were not detected in ars4, ars5 or ars4ars5, however increases in the thiols cysteine, γ‐glutamylcysteine and glutathione were observed. Compared with wild type, the total thiol levels in ars4, ars5 and ars4ars5 mutants were increased up to 80% with combined buthionine sulfoximine and arsenic treatments, suggesting the enhancement of mechanisms that mediate thiol synthesis in the mutants. The presented findings show that PHYA negatively regulates a pathway conferring arsenic tolerance, and that an enhanced thiol synthesis mechanism contributes to the arsenic tolerance of ars4ars5.