bluuebunny/crossref_metadata_2025_split huggingface dataset:
Elevated serum retinol‐binding protein 4 concentrations are associated with renal dysfunction and uric acid in type 2 diabetic patients
Authors: Chang Yu‐Hung , Lin Kun‐Der , Wang Chiao‐Ling , Hsieh Ming‐Chia , Hsiao Pi‐Jung , Shin Shyi‐Jang 
Published: October 2008

AbstractBackgroundWhile some studies have reported that retinol‐binding protein 4 (RBP4) might induce insulin resistance, other studies have demonstrated that the presence of albuminuria in diabetic patients and increased uric acid are related to insulin resistance. Therefore, this study attempted to further investigate the relationship among serum RBP4, serum uric acid, and the severity of albuminuria in diabetic patients.MethodsA total of 95 type 2 diabetic patients and 16 healthy subjects participated in this study. Diabetic patients were classified into normoalbuminuria, microalbuminuria and macroalbuminuria groups according to their urine albumin‐to‐creatinine ratio (ACR). Serum RBP4 was measured by an enzyme‐linked immunosorbent assay (ELISA).ResultsSerum RBP4 was significantly elevated in type 2 diabetic patients with normoalbuminuria (43.4 ± 14.9 µg/mL), microalbuminuria (57.3 ± 24.2 µg/mL) and macroalbuminuria (64.7 ± 27.6 µg/mL) as compared with control patients (32.6 ± 10.0 µg/mL). Serum RBP4 was also significantly elevated in type 2 diabetic patients with microalbuminuria or macroalbuminuria as compared with the normoalbuminuric group. Serum RBP4 in diabetic subjects was positively correlated with triglycerides, uric acid and ACR, and negatively correlated with low‐density lipoprotein cholesterol and estimated glomerular filtration rate (eGFR; with age and gender adjustment in each parameter). Multiple stepwise linear regression analysis showed that uric acid and eGFR remained significantly associated with serum RBP4.ConclusionsBoth eGFR and uric acid are significant determinants of serum RBP4, suggesting that the impaired renal clearance of early diabetic nephropathy affects RBP4 and indirectly supporting the hypothesized link among metabolic syndrome, uric acid and insulin resistance. Copyright © 2008 John Wiley & Sons, Ltd.
Direct determination of celiprolol in human urine using on‐line coupled ITP‐CZE method with fiber‐based DAD
Authors: Mikuš Peter , Maráková Katarína , Marák Jozef , Planková Alexandra , Valášková Iva , Havránek Emil 
Published: October 2008

AbstractThe present work illustrated possibilities of column‐coupling electrophoresis combined with DAD for the direct quantitative determination of trace drug (celiprolol, CEL) in clinical human urine samples. ITP, on‐line coupled with CZE, served as an ideal injection technique (high sample load capacity, narrow and sharp drug zone). Moreover, the ITP provided an effective on‐line sample pretreatment (preseparation, purification and preconcentration of the drug) producing analyte zone suitable for its direct detection and quantitation in CZE stage. Spectral DAD in comparison with single wavelength ultraviolet detection enhanced value of analytical information (i) verifying purity (i.e., spectral homogeneity) of drug zone (according to differences in spectrum profiles when compared tested and reference drug spectra) and (ii) indicating zones/peaks with spectra similar to the drug spectrum (potential structurally related metabolites). The characterization of trace analyte signals superposed on the baseline noise was more definite thanks to the application of background correction and smoothing procedure to the raw DAD spectra (producing relevant spectral response). The proposed ITP‐CZE‐DAD method was characterized by favorable performance parameters for CEL in urine matrices {e.g., the lower limit of quantification was 9.7 ng/mL, RSD and relative error of the determinations were lower than 3% (precision) and 1% (accuracy), respectively, analyte peak exhibited spectral homogeneity (reflecting separation selectivity), separation efficiency was 84 500 theoretical plates} and successfully applied in a trial pharmacokinetic study of CEL.
Separation of non‐UV‐absorbing synthetic polyelectrolytes by CE with contactless conductivity detection
Authors: Spriestersbach Karl‐Heinz , Rittig Frank , Pasch Harald 
Published: October 2008

AbstractA specific method for the separation and detection of non‐UV‐absorbing polyelectrolytes has been developed. The analysis of such polyelectrolytes by liquid chromatography is nearly impossible due to strong ionic interactions and charge density effects. CE makes use of these charge density effects and thus enables for proper separation. A capacitively coupled contactless conductivity detector has been applied for the detection in CE. A low molar mass poly(acrylic acid) sodium salt standard (PAA1.3k) was separated in free solution CE and detected with the contactless conductivity detector. Different amphoteric electrolytes have been tested for their applicability as BGE for the separation of polyelectrolytes with conductivity detection. It has been shown that the best detection results are obtained with an arginine‐sorbate buffer.
Application of Exchangeable Biochemical Reactors with Oxidase‐Catalase‐Co‐immobilizates and Immobilized Microorganisms in a Microfluidic Chip‐Calorimeter
Authors: Leifheit M. , Bergmann W. , Greiser J. 
Published: October 2008

AbstractSeveral methods for the quantitative detection of different compounds, e.g., L‐amino acids, sugars or alcohols in liquid media were developed by application of an automatic measuring unit including a fluid chip‐calorimeter FCC‐21. For this purpose, enzymes were immobilized covalently on the inner and outer surface of CPG (controlled porous glass)‐spherules with an outer diameter of 100 μm and filled into a micro flow‐through reaction chamber (VR = 20 μL). The design of the measuring cell allows for easy insertion into the calorimeter device of a stored series of comfortably pre‐fabricated measuring cells. These cells can be filled with different enzyme immobilizates. Different oxidases were used and co‐immobilized with catalase for the improvement of the detection sensitivity. A signal amplification could be achieved up to a factor of 3.5 with this configuration. β‐D‐glucose, ethanol and L‐lysine could be detected in a range of 0.25–1.75 mM using glucose oxidase, alcohol oxidase and lysine oxidase. The group of oxidases in combination with the enzymatic catalysis of the intermediate H2O2 allows the quantitative detection of a large number of analytes. A good measurement and storage stability could be achieved for several weeks by this immobilization method. In addition to enzyme‐based detection reactions, it was shown that living microorganisms can be immobilized in the reaction chamber. Thus, the system can be used as a whole‐cell biosensor. The quantitative detection of phenol in the range of 10–100 μM could be performed using the actinomycete Rhodococcus sp. immobilized on glass beads by means of embedding into polymers.
Thermodynamic Analysis of the Interaction of Lipopolysaccharides with Cationic Compounds
Authors: Garidel P. , Howe J. , Brandenburg K. 
Published: October 2008

AbstractBacterial lipopolysaccharides (LPS) from Gram‐negative bacteria, located in the outer leaflet of their outer membrane, are called endotoxins due to their ability to induce a variety of biological effects in mammals. Their lipid moiety, lipid A, is called “the endotoxic principle” and is responsible for the toxic effects of LPS. As a result of the polyanionic character of LPS, the study of the interaction with divalent cations Mg2+ and Ca2+ and polycationic peptides such as polymyxin B (PMB) and its nonapeptide PMBN is of considerable interest, and therefore the authors have investigated the interaction of LPS/lipid A with cationic compounds by applying isothermal titration calorimetry (ITC) and differential scanning calorimetry (DSC). The data indicate a clear binding of the divalent cations with the anionic glycolipids, leading to calorimetric reactions, such as an increase in the phase transition temperature, Tm, of the gel to the liquid crystalline phase of LPS, indicating a stabilization of the gel phase. The peptides react quite differently as assessed by DSC. In contrast to the interaction of divalent cations with the glycolipids, a destabilization of the gel phase is observed, accompanied by a decrease in the gel to liquid crystalline phase transition enthalpy for the peptide‐glycolipid interaction. The extent of this effect is peptide‐concentration‐dependent. Using ITC for the analysis of the binding reaction of the cations and the peptides with the glycolipid in the liquid crystalline phase, strong exothermic effects are observed. These are indicative of the dominance of electrostatic attractions between the reaction partners. Interestingly, Ca2+ binding to LPS leads to a slightly exothermic reaction, whereas Mg2+ binding leads to an endothermic reaction (some kJ/mol). The observed highly endothermic binding reactions for the lipid‐peptide interaction in the gel phase are mainly driven by a gain in entropy. This is explained by the fact that during binding, water molecules from the hydration shells of the components are liberated. Although the electrostatic attraction is still the driving force of the interaction, it is quantitatively of minor importance for the interaction in the gel phase. The binding results are discussed in terms of competition between electrostatic interaction and hydration forces. These data are of importance for the understanding of the reaction mechanisms of cationic compounds with LPS under physiological conditions.
Thermodynamic Analysis of Energy Transfer in Acidogenic Cultures
Authors: Bastidas‐Oyanedel J.‐R. , Aceves‐Lara C.‐A. , Ruiz‐Filippi G. , Steyer J.‐P. 
Published: October 2008

AbstractA global thermodynamic analysis, normally used for pure cultures, has been performed for steady‐state data sets from acidogenic mixed cultures. This analysis is a combination of two different thermodynamic approaches, based on tabulated standard Gibbs energy of formation, global stoichiometry and medium compositions. It takes into account the energy transfer efficiency, ϵ, together with the Gibbs free energy dissipation, ΔGo, analysis of the different data. The objective is to describe these systems thermodynamically without any heat measurement. The results show that ϵ is influenced by environmental conditions, where increasing hydraulic retention time increases its value all cases. The pH effect on ϵ is related to metabolic shifts and osmoregulation. Within the environmental conditions analyzed, ϵ ranges from 0.23 for a hydraulic retention time of 20 h and pH 4, to 0.42 for a hydraulic retention time of 8 h and a pH ranging from 7–8.5. The estimated values of ΔGo are comparable to standard Gibbs energy of dissipation reported in the literature. For the data sets analyzed, ΔGo ranges from –1210 kJ/molx, corresponding to a stirring velocity of 300 rpm, pH 6 and a hydraulic retention time of 6 h, to –20744 kJ/molx for pH 4 and a hydraulic retention time of 20 h. For average conclusions, the combined approach based on standard Gibbs energy of formation and global stoichiometry, used in this thermodynamic analysis, allows for the estimation of Gibbs energy dissipation values from the extracellular medium compositions in acidogenic mixed cultures. Such estimated values are comparable to the standard Gibbs energy dissipation values reported in the literature. It is demonstrated that ϵ is affected by the environmental conditions, i.e., stirring velocity, hydraulic retention time and pH. However, a relationship that relates this parameter to environmental conditions was not found and will be the focus of further research.
The Dry Limit of Microbial Life in the Atacama Desert Revealed by Calorimetric Approaches
Authors: Barros N. , Feijóo S. , Salgado J. , Ramajo B. , García J. R. , Hansen L. D. 
Published: October 2008

AbstractThe Atacama desert in Chile is one of the driest and most lifeless environments on Earth. It rains possibly once a decade. NASA examined these soils as a model for the Martian environment by comparing their degradation activity with Martian soil and looking for “the dry limit of life”. The existence of heterotrophic bacteria in Atacama soil was demonstrated by DNA extraction and by the isolation of microorganisms. So far, however, no data have been available about the metabolic activities in these soils due to the limitations of the existing methodologies when applied to desert soils. Calorimetry was used to obtain information on the metabolic and thermal properties of eleven soil samples collected at different sites in the Atacama desert. Differential scanning calorimetry and isothermal calorimetry were employed to determine the pyrolysis properties of the carbon‐containing matter and to measure biomass and microbial metabolism. They were compared to other soil properties such as total carbon and nitrogen, carbon to nitrogen ratio and pH. There was measurable organic matter in nine of the eleven samples and the heat of pyrolysis of those soils was correlated to the carbon content. In five of the eleven samples no biomass could be detected and the existence of basal microbial metabolism could not be established because all samples showed endothermic activity, probably from inorganic reactions with water. Six samples showed microbial activation after the addition of glucose. Carbon content, nitrogen content and the microbial activity after glucose amendment were correlated to the altitude and to the average minimum temperature of the sampling sites calculated from meteorological data. The detectable microbial metabolism was more dissipative with increasing altitude and decreasing temperature.
Novel mechanisms of gene disruption at the medulloblastoma isodicentric 17p11 breakpoint
Authors: McCabe Martin G. , Ichimura Koichi , Pearson Danita M. , Liu Lu , Clifford Steven C. , Ellison David W. , Collins V. Peter 
Published: October 2008

AbstractIsodicentric 17q is the most commonly reported chromosomal abnormality in medulloblastomas. Its frequency suggests that genes disrupted in medulloblastoma formation may play a role in tumorigenesis. We have previously identified two chromosome 17 breakpoint at a 1 Mb resolution. Our aims were to accurately map the position of these breakpoints and to identify mechanisms of gene disruption at this site. CGH with a custom tiling path genomic BAC array of chromosome 17 enriched with fosmids at the breakpoint regions was used to analyze a series of 45 medulloblastomas and three medulloblastoma‐derived cell lines. In total, 17 of 45 medulloblastomas had an isodicentric 17q. Two breakpoint regions were identified and their positions were mapped. The array identified a more complex arrangement at the breakpoint than has been reported previously using lower resolution BAC arrays. The patterns observed indicated that dicentric chromosome formation occurs both via nonallelic homologous recombination between palindromically arranged low copy repeats (the previously accepted mechanism) and by recombination between nonidentical sequences. In addition, novel alternative structural alterations, a homozygous deletion and a duplication, were identified within the chromosome breakpoint region in two cases. At the resolution of the array, these structural alterations spanned the same genes as cases with dicentric 17q formation, implying that the disruption of genes at the chromosome breakpoint itself may be of greater biological significance than has previously been suspected. © 2008 Wiley‐Liss, Inc.
Reverse painting of microdissected chromosome 19 markers in ovarian carcinoma identifies a complex rearrangement map
Authors: Micci Francesca , Weimer Jörg , Haugom Lisbeth , Skotheim Rolf I. , Grunewald Regina , Abeler Vera M. , Silins Ilvar , Lothe Ragnhild A. , Trope Claes G. , Arnold Norbert , Heim Sverre 
Published: October 2008

AbstractAlterations of chromosome bands 19p13 and 19q13 in the form of added extra material of unknown origin are among the most frequent cytogenetic changes in ovarian carcinomas. To investigate the chromosomal composition of the 19p+ and/or 19q+ markers, we selected for examination 26 ovarian carcinomas which by G‐banding had one to four 19p+ and/or 19q+, in total 37 markers. These cases were then subjected to chromosomal microdissection with subsequent reverse painting, which gave informative results on 29 markers. The breakpoints on chromosome 19 were located in both the short (p; n = 15) and the long (q; n = 10) arms, as well as in the centromeric (n = 2) and pericentromeric (n = 6) region. The analysis showed that many chromosomes added material to chromosome 19, but the chromosome arms 11q, 21q, and 22q were particularly common donors. Homogeneously staining regions (hsr) were seen in only three markers, in all of them consisting of 19p material. Eighteen markers were derived from an unbalanced translocation involving chromosome 19. In five markers, chromosome 19 was rearranged with two chromosomes. The most complex marker showed chromosome 19 rearranged with three other chromosomes, i.e., X, 13, and 16. In five markers, all of the additional material stemmed from chromosome 19 itself. This is the first large chromosome microdissection/FISH study of chromosome 19 markers in ovarian carcinomas. A detailed map of the rearrangements should provide clues to the positions of oncogenes and potential fusion genes important in ovarian carcinogenesis. © 2008 Wiley‐Liss, Inc.
Motor threshold in transcranial magnetic stimulation: The impact of white matter fiber orientation and skull‐to‐cortex distance
Authors: Herbsman Tal , Forster Lauren , Molnar Christine , Dougherty Robert , Christie Doug , Koola Jejo , Ramsey Dave , Morgan Paul S. , Bohning Daryl E. , George Mark S. , Nahas Ziad 
Published: October 2008

AbstractThe electrophysiology of transcranial magnetic stimulation (TMS) of motor cortex is not well understood. In this study, we investigate several structural parameters of the corticospinal tract and their relation to the TMS motor threshold (MT) in 17 subjects, with and without schizophrenia. We obtained structural and diffusion tensor MRI scans and measured the fractional anisotropy and principal diffusion direction for regions of interest in the corticospinal tract. We also measured the skull‐to‐cortex distance over the left motor region. The anterior–posterior trajectory of principle diffusion direction of the corticospinal tract and skull‐to‐cortex distance were both found to be highly correlated with MT, while fractional anisotropy, age and schizophrenia status were not. Two parameters—skull‐to‐cortex distance and the anterior component of the principle diffusion direction of the corticospinal tract as it passes the internal capsule—are highly predictive of MT in a linear regression model, and account for 82% of the variance observed (R2 = 0.82, F = 20.27, P < 0.0001) in measurements of MT. The corticospinal tract's anterior–posterior direction alone contributes 13% of the variance explained. Hum Brain Mapp, 2009. © 2008 Wiley‐Liss, Inc.
Dual job holding general practitioners: the effect of patient shortage
Authors: Godager Geir , Lurås Hilde 
Published: October 2008

AbstractIn 2001, a listpatient system with capitation payment was introduced in Norwegian general practice. After an allocation process where each inhabitant was listed with a general practitioner (GP), a considerable share of the GPs got fewer persons listed than they would have preferred. We examine whether GPs who experience a shortage of patients to a larger extent than other GPs seek to hold a second job in the community health service even though the wage rate is low compared with the wage rate in general practice. Assuming utility maximization, we model the effect of patient shortage on a GP's decision to contract for a second job in the community health service. The model predicts a positive relationship between patient shortage and participation in the community health service. This prediction is tested by means of censored regression analyses, taking account of labour supply as a censored variable. We find a significant effect of patient shortage on the number of hours the GPs supply to community health service. The estimated marginal effect is 1.72 hours per week. Copyright © 2008 John Wiley & Sons Ltd.
Third degree waiting time discrimination: optimal allocation of a public sector healthcare treatment under rationing by waiting
Authors: Gravelle Hugh , Siciliani Luigi 
Published: October 2008

AbstractIn many public healthcare systems treatments are rationed by waiting time. We examine the optimal allocation of a fixed supply of a given treatment between different groups of patients. Even in the absence of any distributional aims, welfare is increased by third degree waiting time discrimination: setting different waiting times for different groups waiting for the same treatment. Because waiting time imposes dead weight losses on patients, lower waiting times should be offered to groups with higher marginal waiting time costs and with less elastic demand for the treatment. Copyright © 2008 John Wiley & Sons, Ltd.
Frequent concomitant epigenetic silencing of the stress‐responsive tumor suppressor gene CADM1, and its interacting partner DAL‐1 in nasal NK/T‐cell lymphoma
Authors: Fu Li , Gao Zifen , Zhang Xiaohua , Tsang Ying Hung , Goh Hwee Koon , Geng Hua , Shimizu Norio , Tsuchiyama Junjiro , Srivastava Gopesh , Tao Qian 
Published: October 2008

AbstractNasal NK/T‐cell lymphoma (NL) is a rare but clinically important entity of lymphoma. Its preferential incidence in Orientals but not Caucasians suggests possible genetic predisposition. 11q deletion is common in NL, indicating certain tumor suppressor genes (TSGs) at this locus involved in its pathogenesis. We investigated the expression and methylation of an 11q23.2 TSG, CADM1 (or TSLC1), and its partner DAL‐1 (or EPB41L3) in NL. Methylation and silencing of CADM1 were detected in 2 NL and 4 of 8 (50%) of non‐Hodgkin lymphoma (NHL) cell lines, but not in normal NK cells and normal PBMC. Absence of CADM1 protein was also detected in NL cell lines. 5‐aza‐2′‐deoxycytidine (Aza) demethylation or genetic knockout of both DNMT1 and 3B genes restored CADM1 and DAL‐1 expression. CADM1 methylation was further detected in 36 of 45 (80%) of NL tumors. Concomitantly, DAL‐1 was epigenetically inactivated in NL cell lines and virtually all the tumors with methylated CADM1. A significant correlation between the methylation of both genes was found (p < 0.0001). Homozygous deletion of CADM1 was detected in only 3 of 18 (17%) of tumors. The stress‐response of CADM1 was abolished when its promoter becomes methylated. Our results demonstrate a frequent, predominant epigenetic silencing of CADM1 and DAL‐1 in NL, which likely play a synergic role in NL pathogenesis. © 2008 Wiley‐Liss, Inc.