bluuebunny/crossref_metadata_2025_split huggingface dataset:
Independent clinical validation of a Canadian FRAX tool: Fracture prediction and model calibration
Authors: Leslie William D , Lix Lisa M , Johansson Helena , Oden Anders , McCloskey Eugene , Kanis John A 
Published: May 2010

Abstract
A FRAX model for Canada was constructed for prediction of osteoporotic and hip fracture risk using national hip fracture data with and without the use of femoral neck bone mineral density (BMD). Performance of this system was assessed independently in a large clinical cohort of 36,730 women and 2873 men from the Manitoba Bone Density Program database that tracks all clinical dual-energy X-ray absorptiometry (DXA) test results for the Province of Manitoba, Canada. Linkage with other provincial health databases allowed for the direct comparison of fracture risk estimates from the Canadian FRAX model with observed fracture rates to 10 years (549 individuals with incident hip fractures and 2543 with incident osteoporotic fractures). The 10-year Kaplan-Meier estimate for hip fractures in women was 2.7% [95% confidence interval (CI) 2.1–3.4%] with a predicted value of 2.8% for FRAX with BMD, and in men the observed risk was 3.5% (95% CI 0.8–6.2%) with predicted value of 2.9%. The 10-year estimate of osteoporotic fracture risk for all women was 12.0% (95% CI 10.8–13.4%) with a predicted value of 11.1% for FRAX with BMD, and in men, the observed risk was 10.7% (95% CI 6.6–14.9%) with a predicted value of 8.4%. Discrepancies were observed within some subgroups but generally were small. Fracture discrimination based on receiver operating characteristic curve analysis was comparable with published meta-analyses with area under the curve for osteoporotic fracture prediction of 0.694 (95% CI 0.684–0.705) for FRAX with BMD and for hip fractures 0.830 (95% CI 0.815–0.846), both of which were better than FRAX without BMD or BMD alone. Individual risk factors considered by FRAX made significant independent contributions to fracture prediction in one or more of the models. In conclusion, a Canadian FRAX tool calibrated on national hip fracture data generates fracture risk predictions that generally are consistent with observed fracture rates across a wide range of risk categories. © 2010 American Society for Bone and Mineral Research.
Association between bone turnover rate and bone microarchitecture in men: The STRAMBO study
Authors: Chaitou Ali , Boutroy Stephanie , Vilayphiou Nicolas , Munoz Françoise , Delmas Pierre D , Chapurlat Roland , Szulc Pawel 
Published: May 2010

Abstract
Few data concern the relationship between bone turnover and microarchitecture in men. We investigated the association between levels of biochemical markers of bone turnover (BTM) and bone microarchitecture in 1149 men aged 19 to 85 years. Bone microarchitecture was assessed by high-resolution peripheral quantitative computed tomography at the distal radius and tibia. Bone formation was assessed by serum osteocalcin, bone alkaline phosphatase, and N-terminal extension propeptide of type I collagen. Bone resorption was assessed by serum C-terminal telopeptide of type I collagen and urinary excretion of total deoxypyridinoline. BTM levels were high in young men and decreased until age 50 years. Urinary deoxypyridinoline (DPD) increased after age 70 years, whereas other BTMs remained stable. Before 50 years of age, only cortical volumetric bone mineral density (Dcort) correlated negatively with BTM levels. Between 50 and 70 years of age, Dcort and some microarchitectural parameters correlated significantly with BTM at the radius and tibia. After 70 years of age, higher BTM levels were associated with lower cortical thickness and Dcort at both the skeletal sites. At the distal radius, men in the highest BTM quartile had lower trabecular density, number (Tb.N), and thickness (Tb.Th) and more heterogeneous trabecular distribution compared with men in the lower quartiles. At the distal tibia, higher BTM levels were associated with lower Tb.N and Tb.Th in the central but not subendocortical area. Thus, in men, bone microarchitecture depends weakly on the current bone turnover rate until age 70. Thereafter, bone turnover seems to be a significant determinant of bone microarchitecture. © 2010 American Society for Bone and Mineral Research.
Early-onset, progressive, frequent, extensive, and severe bone mineral and renal complications in multiple endocrine neoplasia type 1–associated primary hyperparathyroidism
Authors: Lourenço Delmar M , Coutinho Flavia L , Toledo Rodrigo A , Montenegro Fabio LM , Correia-Deur Joya EM , Toledo Sergio PA 
Published: May 2010

Abstract
Differences in bone mineral density (BMD) patterns have been recently reported between multiple endocrine neoplasia type 1–related primary hyperparathyroidism (HPT/MEN1) and sporadic primary HPT. However, studies on the early and later outcomes of bone/renal complications in HPT/MEN1 are lacking. In this cross-sectional study, performed in a tertiary academic hospital, 36 patients cases with uncontrolled HPT from 8 unrelated MEN1 families underwent dual-energy X-ray absorptiometry (DXA) scanning of the proximal one-third of the distal radius (1/3DR), femoral neck, total hip, and lumbar spine (LS). The mean age of the patients was 38.9 ± 14.5 years. Parathyroid hormone (PTH)/calcium values were mildly elevated despite an overall high percentage of bone demineralization (77.8%). In the younger group (&lt;50 years of age), demineralization in the 1/3DR was more frequent, more severe, and occurred earlier (40%; Z-score −1.81 ± 0.26). The older group (&gt;50 years of age) had a higher frequency of bone demineralization at all sites (p &lt; .005) and a larger number of affected bone sites (p &lt; .0001), and BMD was more severely compromised in the 1/3DR (p = .007) and LS (p = .002). BMD values were lower in symptomatic (88.9%) than in asymptomatic HPT patients (p &lt; .006). Patients with long-standing HPT (&gt;10 years) and gastrinoma/HPT presented significantly lower 1/3DR BMD values. Urolithiasis occurred earlier (&lt;30 years) and more frequently (75%) and was associated with related renal comorbidities (50%) and renal insufficiency in the older group (33%). Bone mineral– and urolithiasis-related renal complications in HPT/MEN1 are early-onset, frequent, extensive, severe, and progressive. These data should be considered in the individualized clinical/surgical management of patients with MEN1-associated HPT. © 2010 American Society for Bone and Mineral Research.
Increased osteocyte death and mineralization inside bone after parathyroidectomy in patients with secondary hyperparathyroidism
Authors: Yajima Aiji , Inaba Masaaki , Tominaga Yoshihiro , Nishizawa Yoshiki , Ikeda Kyoji , Ito Akemi 
Published: May 2010

Abstract
In order to gain insight into the mechanisms underlying the dynamic changes in bone metabolism and bone quality after parathyroidectomy (PTX) in secondary hyperparathyroid patients with high levels of parathyroid hormone (PTH), we performed bone histomorphometric analysis with tetracycline labeling in iliac bone biopsy specimens taken before and after PTX, with special attention paid to osteocytes. At 2 to 4 weeks after PTX, PTH concentrations decreased markedly with evident reductions in bone turnover markers. Histomorphometry revealed that at 2 to 4 weeks following PTX, the osteoclast surface decreased to nearly 0%, with a substantial increase in osteoid volume and a reduction in fibrosis volume. Labeling with tetracycline was observed not only at the mineralization front on the bone surface but also around the osteocyte lacunar walls and canaliculi within both the basic multicellular units (BMUs) and bone structural units (BSUs), suggesting that mineralization was taking place along the lacunocanalicular system after PTX. The tetracycline-labeled area was much greater in the BSUs than in the BMUs and at the mineralization front, and the tetracycline labeling in the BSUs was markedly increased after PTX compared with that in the low- and high-PTH control groups without PTX. The osteocyte number was decreased significantly after PTX, concomitant with an increase in the number of empty lacunae and a reduction of lacunar volume. Thus the increased osteocyte death and mineralization around the lacunocanalicular system in association with a rapid decline in PTH may underlie the changes in bone metabolism and quality that occur following PTX. © 2010 American Society for Bone and Mineral Research.
Gene expression of growth hormone family and glucocorticoid receptors, osmosensors, and ion transporters in the gill during seawater acclimation of Mozambique tilapia, Oreochromis mossambicus
Authors: Breves Jason P. , Fox Bradley K. , Pierce Andrew L. , Hirano Tetsuya , Grau E. Gordon 
Published: May 2010

AbstractThis study characterized endocrine and ionoregulatory responses accompanying seawater (SW) acclimation in Mozambique tilapia (Oreochromis mossambicus). Changes in plasma hormones and gene expression of hormone receptors, putative osmosensors, and ion transporters in the gill were measured. Transfer of freshwater (FW)‐acclimated tilapia to SW resulted in a marked elevation in plasma osmolality and a significant rise in plasma growth hormone (GH) levels at 12 hr and 14 days after transfer. Significant reductions in plasma prolactin (PRL177 and PRL188) levels also occurred in SW‐transferred fish; no effect of transfer upon plasma cortisol or insulin‐like growth factor I was observed. Gene expression of GH receptor increased strongly 6 hr after transfer, whereas PRL receptor was lower than controls at 12 hr. By contrast, mRNA levels of somatolactin and glucocorticoid receptors were unaffected by SW transfer. Osmotic stress transcription factor 1 mRNA levels rose significantly between 3 and 12 hr, whereas the calcium‐sensing receptor was unaffected. Aquaporin‐3 gene expression was strongly down‐regulated during SW acclimation from 12 hr until the conclusion of the experiment. Na+/K+/2Cl− cotransporter gene expression increased significantly 3 hr after transfer, whereas expression of Na+/Cl− cotransporter, specific to FW‐type chloride cells, declined by 6 hr into SW acclimation. The response of Na+/H+ exchanger was less pronounced, but showed a similar pattern to that of the Na+/Cl− cotransporter. These results suggest that acquisition of hyposmoregulatory mechanisms in Mozambique tilapia entails the coordinated interaction of systemic hormones with local factors in the gill, including hormone receptors, ion transporters, and osmosensors. J. Exp. Zool. 313A:432–441, 2010. © 2010 Wiley‐Liss, Inc.
Morphological correlates of sprint swimming speed in five species of spadefoot toad tadpoles: Comparison of morphometric methods
Authors: Arendt Jeff 
Published: May 2010

AbstractThe relationship between vertebrate morphology and swimming performance has long interested biologists. Recent work on predator‐induced morphological plasticity of anuran tadpoles has increased this interest. Here, I use data on five species of spadefoot toad tadpoles (Scaphiopodidae) to compare linear and geometric morphometrics. Linear measures explain only 7–26% of the variation in swimming speed, depending on species, whereas geometric morphometrics could explain 24–46% of the same variation. I also compare two methods for examining how similar the morphology–swimming speed relationship is among species. A canonical variate derived from a MANCOVA approach successfully detected species differences in these relationships, whether using linear or geometric methods, but a canonical correlation approach failed in both cases. Overall, tadpoles with smaller bodies, larger tails, and larger tail muscles are faster swimmers but the details of how these shape changes are achieved differed among species. For example, in some species a smaller body was achieved primarily by reducing abdomen size, whereas in others both the head and abdomen are smaller.Faster swimmers also had deeper tails, especially in the posterior half of the tail. This pattern would have been missed in standard linear morphometrics which usually only measures maximum tail depth. J. Morphol. 271:1044‐1052, 2010. © 2010 Wiley‐Liss, Inc.
Selective cleavage of protonated penetratin and its substitutes under low‐energy collision‐induced dissociation condition
Authors: Peng Juan , Zu Lily , Fang Weihai , Huang Lingyun , Wang Yaru , He Dacheng 
Published: May 2010

AbstractAn understanding of the dissociation of penetratin is important for improving its metabolic stability and cargo‐delivery efficiency. In this study, we describe the selective cleavage of the K15–K16 amide bond of penetratin under the low‐energy collision‐induced dissociation condition in mass spectrometry. A variety of penetratin substitutes have been studied in which key basic amino acids have been substituted within the sequence. The calculated structure indicates that an α‐helix structure prevents the fragmentation of the central peptide domain and the side chain of lysine is involved in the proton translocation process. Copyright © 2010 John Wiley & Sons, Ltd.
Best‐practice recommendations for estimating interaction effects using moderated multiple regression
Authors: Aguinis Herman , Gottfredson Ryan K. 
Published: May 2010

AbstractAn interaction effect indicates that a relationship is contingent upon the values of another (moderator) variable. Thus, interaction effects describe conditions under which relationships change in strength and/or direction. Understanding interaction effects is essential for the advancement of the organizational sciences because they highlight a theory's boundary conditions. We describe procedures for estimating and interpreting interaction effects using moderated multiple regression (MMR). We distill the technical literature for a general readership of organizational science researchers and include specific best‐practice recommendations regarding actions researchers can take before and after data collection to improve the accuracy of MMR‐based conclusions regarding interaction effects. Copyright © 2010 John Wiley & Sons, Ltd.
Bivariate colour maps for visualizing climate data
Authors: Teuling A. J. , Stöckli R. , Seneviratne S. I. 
Published: May 2010

AbstractThe increasing availability of gridded, high‐resolution, multivariate climatological data sets calls for innovative approaches to visualize inter‐variable relations. In this study, we present a methodology, based on properties of common colour schemes, to plot two variables in a single colour map by using a two‐dimensional colour legend for both sequential and diverging data. This is especially suited for climate data as the spatial distribution of the relation between different variables is often as important as the distribution of variables individually. Two example applications are given to illustrate the use of the method: one that shows the global distribution of climate based on observed temperature and relative humidity, and the other showing the distribution of recent changes in observed temperature and precipitation over Europe. A flexible and easy‐to‐implement method is provided to construct different colour legends for sequential and diverging data. Copyright © 2010 Royal Meteorological Society
Speciation of inorganic and tetramethyltin by headspace solid‐phase microextraction and gas chromatography–mass spectrometry
Authors: Tzollas Nikolaos M. , Zachariadis George A. 
Published: May 2010

AbstractA headspace solid‐phase microextraction (HS‐SPME) method coupled to GC‐MS was developed in order to determine trace levels of tetramethyltin (TeMT) and inorganic tin (iSn) after ethylation to tetraethyltin (TeET) in various matrices. The derivatization of iSn and the extraction of both TeMT and iSn as TeET were performed in one step. Sodium tetraethylborate (NaBEt4) was used as derivatization agent and the volatile derivatives were absorbed on a PDMS‐coated fused silica fiber. The conditions for the HS‐SPME procedure were optimized in order to gain in repeatability and sensitivity. Several critical parameters of GC‐MS were also studied. The detection of TeMT and iSn as TeET peaks was performed by the SIM mode. The precision of the proposed method is satisfactory providing RSD values below 10% for both tin species and good linearity up to 10 μg/L. The developed method was successfully applied to the determination of tin species in several samples like canned fish, fish tissues, aquatic plants, canned mineral water and sea water. The proposed HS‐SPME‐GC‐MS method was proved suitable to monitor the concentration levels of toxic tin compounds in environmental and biological samples.
Silica‐based zwitterionic monolithic stationary phase for separation of neutral and ionized solutes using pressurized CEC
Authors: Huang Guihua , Zeng Wencan , Lin Xucong , Xie Zenghong 
Published: May 2010

AbstractA porous zwitterionic monolith was prepared by in situ covalent attachment of lysine to a γ‐glycidoxypropyltrimethosysilane‐modified silica monolith. The prepared column was used to perform neutral and ionized solutes separations by pressurized (pCEC). Due to the zwitterionic nature of the resulting stationary phase, the monolithic column provided both electrostatic attraction and repulsion sites for electrochromatographic retention for ionized solutes. Separation of several nucleotides was investigated on the monolithic column. It was shown that the nucleotides could be separated based on hydrophilic and electrostatic interactions between the stationary phase and analyte. Besides, the separation property of the zwitterionic silica monolith was compared with the use of diamine‐bonded silica monolith as stationary phase. As expected, the lysine monolith exhibited a lower retention for the five nucleotides, which was due to the dissociation of the external carboxylic acid groups, leading to electrostatic repulsion with negatively charged solutes. Under the same experimental conditions, separation of the five nucleotides on the zwitterionic column was in less than 8 min, while that on the diamine column was in approximately 60 min.
Solid‐phase extraction of matrine and oxymatrine from Sophora Flavescens Ait using amino‐imidazolium polymer
Authors: Bi Wentao , Tian Minglei , Row Kyung Ho 
Published: May 2010

AbstractA new, polymer‐confined, ionic liquid sorbent was developed by a process involving polymerization and modification. The obtained particles were successfully used as a special sorbent in SPE process to isolate matrine and oxymatrine from Sophora Flavescens Ait. Different washing and elution solvents, such as ethanol, methanol, acetonitrile and methanol/triethylamine (90:10, v/v), were evaluated. Compared with the C18 and NH2 sorbents, the amino‐imidazolium polymer sorbent exhibited higher selectivity. Quantitative analysis was carried out by using a C18 column. The two compounds exhibited good linearity from 5×10−3 to 0.50 mg/mL (r2>0.99). The bound amounts between target compounds and proteins were obtained by this sorbent. After three recycles of amino‐imidazolium polymer, the extract amounts of the target compounds were not significantly decreased.
Semi‐preparative high‐speed counter‐current chromatography separation of alkaloids from embryo of the seed of Nelumbo nucifera Gaertn by pH‐gradient elution
Authors: Duanmu Qingping , Li Aifeng , Sun Ailing , Liu Renmin , Li Xiaopeng 
Published: May 2010

AbstractA new high‐speed counter‐current chromatography method for semi‐preparative separation and purification of alkaloids from embryo of the seed of Nelumbo nucifera Gaertn was developed by using pH‐gradient elution mode. Diethyl ether was used as the stationary phase of the two‐phase solvent system and Na2HPO4/NaH2PO4 buffer solution with pH values of 7.5 and 7.2 in gradient mode as the mobile phase. Consequently, 33 mg of liensinine, 42 mg of isoliensinine, and 67 mg of neferine were obtained from 200 mg of crude extracts. The purities of them were all over 98% as determined by HPLC area normalization method, and the structures were identified by 1H‐NMR and 13C‐NMR.
Potential‐driven peptide extractions across supported liquid membranes: Investigation of principal operational parameters
Authors: Balchen Marte , Jensen Henrik , Reubsaet Léon , Pedersen‐Bjergaard Stig 
Published: May 2010

AbstractFundamental experiments on electromembrane extraction were performed to increase the basic knowledge about the current and the mass transfer of target peptides and background electrolyte ions. Three peptides (angiotensin 2, bradykinin, and enkephalin) were extracted from 500 μL aqueous donor solution (1 mM HCl, positive electrode), through a 200 μm supported liquid membrane (SLM) of 1‐octanol/di‐isobutylketon/di‐(2‐ethylhexyl) phosphate (55:35:10 w/w/w) sustained in the pores of a porous hollow fiber, and into 25 μL aqueous acceptor solution (50 mM HCl, negative electrode) present inside the lumen of the fiber by the application of an electrical potential (50 V) and agitation (1050 rpm). Recoveries were typically in the range of 55–65% after 5 min of extraction and were principally determined by the chemical composition of the SLM and by the applied voltage. The electrical current in the system was measured during the extraction and was close to 350 μA. The current arose to some extent from mass transfer of the target peptides, but the major contribution was due to a background current from di‐(2‐ethylhexyl) phosphate in the SLM and from mass transfer of background electrolytes. Operation at relatively low background current was important to maintain a stable system.
Simultaneous determination of anthracyclines and taxanes in human serum using online sample extraction coupled to high performance liquid chromatography with UV detection
Authors: Bermingham Shane , O'Connor Robert , Regan Fiona , McMahon Gillian P. 
Published: May 2010

AbstractAn online SPE‐LC method that can determine both anthracyclines and taxanes simultaneously in human serum samples is reported. The entire method of extraction, separation and UV detection was achieved online by column switching between an SPE column (Biotrap 500 (20×4 mm)) and an analytical column (Zorbax XDB C18, 150×4.6 mm, 5 μm) with a 23 min total cycle time. The method is linear (r2>0.998) over the range of 0.5–25 μg/mL. The analytes of interest are retained on the SPE column with good recovery (84–117%), while proteins and other serum components elute to waste. This online clean‐up is much faster (150 s) and less manual than traditional off‐line extraction methods. Using 0.1 mL spiked serum samples, the LOQ was 0.5 μg/mL. Intra‐ and inter‐day precision were acceptable (≤15% RSD) at and above the LOQ. The method was applied to the analysis of serum samples from patients undergoing chemotherapy with these agents.
HPLC‐DAD method for the simultaneous determination of zofenopril and hydrochlorothiazide in oral pharmaceutical formulations
Authors: Carlucci Giuseppe , Di Federico Lucia , Iuliani Piera 
Published: May 2010

AbstractAn HPLC method with DAD detection was developed and validated for the simultaneous determination of zofenopril and hydrochlorothiazide in tablets. The separation was carried out through a gradient elution using an Agilent LiChrospher C18 column (250×4.0 mm id, 5 μm) and a mobile phase consisting of (A) water–TFA (99.9:0.1 v/v) and (B) acetonitrile–TFA (99.1:0.1 v/v) delivered at a flow‐rate of 1.0 mL/min. 8‐Chlorotheophylline was used as internal standard. Calibration curves were found to be linear for the two drugs over the concentration ranges of 5.0–40 and 1.0–20 μg/mL for zofenopril and hydrochlorothiazide, respectively. Linearity, precision, accuracy, specificity and robustness were determined in order to validate the proposed method, which was further applied to the analysis of commercial tablets. The proposed method is simple and rapid, and gives accurate and precise results.