bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pharmacological characterization of P2Y receptor subtypes on isolated tiger salamander Müller cells
Authors: Reifel Saltzberg Jenny M. , Garvey Katherine A. , Keirstead Susan A. 
Published: March 2003

AbstractMüller cells express a variety of neurotransmitter receptors that permit them to “sense” the extracellular environment within the retina. We have used a battery of agonists and antagonists to characterize the purinergic receptor subtypes expressed on isolated tiger salamander Müller cells. Changes in intracellular calcium ion concentration ([Ca2+]i) in Müller cells were measured using the Ca2+ indicator dye Fura‐2 and digital imaging microscopy. ATP, 2‐methylthio‐ATP, 2‐methylthio‐ADP, ADP, UTP, UDP, deoxyATP, and 3′‐O‐(4‐benzoyl)benzoyl ATP evoked increases in [Ca2+]i in both the presence and absence of extracellular Ca2+. Therefore, the increases we observed were likely due to intracellular Ca2+ release mediated by G‐protein‐coupled P2Y receptor activation, rather than Ca2+ influx via P2X receptor channels. The P2Y1 receptor agonists 2‐methylthio‐ATP, 2‐methylthio‐ADP, and ADP evoked increases in [Ca2+]i that were inhibited by the P2Y1 receptor antagonists adenosine 3′‐phosphate 5′‐phosphosulfate and 2′‐deoxy‐N6‐methyleneadenosine‐3′,5′‐bisphosphate. Responses to ADP were not completely inhibited by the P2Y1 receptor antagonists. The residual response to ADP could be mediated by P2Y13 receptors. UTP evoked an increase in [Ca2+]i that was partially inhibited by suramin, suggesting that Müller cells express P2Y2 and P2Y4 receptors. The P2Y6 receptor agonist UDP, and the P2Y11 receptor agonists deoxyATP, and 3′‐O‐(4‐benzoyl)benzoyl ATP, evoked increases in [Ca2+]i in Müller cells. We conclude that isolated tiger salamander Müller cells express P2Y1, P2Y2, P2Y6, P2Y11, and possibly P2Y4 and P2Y13 receptors. Therefore, the physiological release of ATP, ADP, UTP, and UDP and/or their accumulation in the retina under pathological conditions could stimulate increases in [Ca2+]i in Müller cells. GLIA 42:149–159, 2003. © 2003 Wiley‐Liss, Inc.
Differentiation of radial glia‐like cells from embryonic stem cells
Authors: Liour Sean S. , Yu Robert K. 
Published: March 2003

AbstractRadial glial cells play important roles in neural development. They provide support and guidance for neuronal migration and give rise to neurons and glia. In vitro, neurons, astrocytes, and oligodendrocytes can be generated from neural and embryonic stem cells, but the generation of radial glial cells from these stem cells has not yet been reported. Since the differentiation of radial glial cells is indispensable during brain development, we hypothesize that stem cells also generate radial glial cells during in vitro neural differentiation. To test this hypothesis, we utilized five different clones of mouse embryonic (ES) and embryonal carcinoma (EC) stem cell lines to investigate the differentiation of radial glial cells during in vitro neural differentiation. Here, we demonstrate that radial glia‐like cells can be generated from ES/EC cell lines. These ES/EC cell‐derived radial glia‐like cells are similar in morphology to radial glial cells in vivo, i.e., they are bipolar with an unbranched long process and a short process. They also express several cytoskeletal markers, such as nestin, RC2, and/or GFAP, that are characteristics of radial glial cells in vivo. The processes of these in vitro generated radial glia‐like cells are organized into parallel arrays that resemble the radial glial scaffolds in neocortical development. Since radial glia‐like cells were observed in all five clones of ES/EC cells tested, we suggest that the differentiation of radial glial cells may be a common pathway during in vitro neural differentiation of ES cells. This novel in vitro model system should facilitate the investigation of regulation of radial glial cell differentiation and its biological function. GLIA 42:109–117, 2003. © 2003 Wiley‐Liss, Inc.
Microfilament and microtubule organization and dynamics in process extension by central glia‐4 oligodendrocytes: Evidence for a microtubule organizing center
Authors: Rumsby Martin , Afsari Farinaz , Stark Meg , Hughson Elaine 
Published: March 2003

AbstractMicrofilaments in freshly adhering CG‐4 cells and differentiated CG‐4 oligodendrocytes are concentrated at the tips and edges of rapidly forming processes while microtubules are concentrated in new processes and extend from a concentrated spot of α‐tubulin staining in the cell body to the cell periphery. In motile bipolar CG‐4 cells, microfilaments are heavily concentrated at the flattened end of one process and along the rim of processes and the cell body: microtubules are concentrated along main processes and splay out into process tips and the cell body. In differentiated CG‐4 oligodendrocytes, microfilaments are concentrated at the many process tips, in filopodia and in fine processes, but are not obvious in main processes where separate bundles of microtubules, which diverge at process branch points, are concentrated. γ‐tubulin, involved in microtubule nucleation, is concentrated at a small discrete area in the cell body, indicative of a microtubule organizing center. Polymerization of both actin and tubulin is required for initial process elaboration. Depolymerization of microtubules, but not of microfilaments, causes complete retraction of bipolar CG‐4 cell processes. This process retraction does not occur if microfilaments are depolymerized first, indicating that process extension/retraction in motile bipolar CG‐4 cells may occur by a balance of motor protein‐driven forces as suggested for growth cone motility. Cytoskeleton organization in CG‐4 cells is very similar to that reported for oligodendrocytes. CG‐4 cells are thus a useful model for investigating the signals and mechanisms regulating oligodendrocyte process dynamics. GLIA 42:118–129, 2003. © 2003 Wiley‐Liss, Inc.
Does it matter who you are or what you gain? an experimental study of preferences for resource allocation
Authors: Schwappach David L.B. 
Published: March 2003

AbstractUsing an experimental conjoint‐analysis like approach, preferences for resource allocation were studied. An interactive survey was developed which was published in the World Wide Web. A convenience sample of undergraduate students participated in the study. Subjects were confronted with nine pairwise scenarios describing hypothetical patient groups in need of life‐saving treatments. The patient groups presented differed in terms of their health‐related lifestyle, socioeconomic status, age, life expectancy, quality of life after treatment and whether they had received extensive medical care in the past. Participants were asked to allocate a finite budget to each patient group. All attributes used in this study significantly influenced respondents' preferences on how to allocate the budget between patient groups. The general importance of attributes used in the QALY approach is supported by this study with quality of life being a central criterion. The distributional patterns observed were, however, different from those expected when rigorously adhering to the QALY framework: In only a very small fraction of allocations subjects distributed the entire budget strictly on the patient group expecting the highest QALY gain. The vast majority of responders was willing to trade efficiency for a more equal distribution of resources. The approach dsecribed can be used to analyze the importance people place on different attributes in resource allocation decisions and to study preferences for the final distribution of resources. Copyright © 2002 John Wiley & Sons, Ltd.
Health status and heterogeneity of cost‐sharing responsiveness: how do sick people respond to cost‐sharing?
Authors: Remler Dahlia K. , Atherly Adam J. 
Published: March 2003

AbstractThis paper examines whether the responsiveness of health care utilization to cost‐sharing varies by health status and the implications of such heterogeneity. First, we show theoretically that if health care utilization of those in poor health is less responsive to cost sharing, this, combined with the skewness of health expenditures in health status, leads to overestimates of the effect of cost sharing. This bias is exacerbated when elasticities are generalized to populations with greater expenditure skewness. Second, we show empirically that cost‐sharing responsiveness does differ by health status using data from the Medicare Current Beneficiary Survey. Medicare beneficiaries are stratified into health status groups based on activity of daily living (ADL) impairments and self‐reported health status. Separately, for each of the health status groups, we estimate the effect of Medigap insurance on Part B utilization using a two‐part expenditure model. We find that the change in expenditures associated with Medigap is smaller for those in poorer health. For example, when stratified using ADLs, Medigap insurance increases expenditures for ‘healthy’ groups by 36.4%, while the increase for the ‘sick’ group is 12.7%. Results are qualitatively the same for different forms of supplemental insurance and different methods of health status stratification. We develop a test to demonstrate that adjusting our results for selection bias would result in estimates of greater heterogeneity. Our results imply that a lowerbound estimate of the bias from neglecting heterogeneity is about 2–7%. Copyright © 2002 John Wiley & Sons, Ltd.
The changing public/private mix in dentistry in the UK–a supply‐side perspective
Authors: Lynch Mauricea , Calnan Michael 
Published: March 2003

AbstractThis paper examines the factors beyond NHS dentists' remuneration which may explain the variations in the public/private mix in general dental practitioners' workload in the UK. Given that NHS dentistry is subject to a fixed price system, the study focused mainly on non‐income supply‐side factors. Using data from a postal survey of a national random sample of dentists practising in the NHS in England in 1997, the study found that the strategies adopted by dentists in the management of NHS lists and the evidence that dentists spent significantly more time in private consultations compared with NHS consultations support concerns over equity of access to dental care and the quality of NHS dentistry. Dentists' attitudes to NHS and private dentistry revealed considerable ambiguity towards the NHS. While, on the one hand, the lack of sufficient demand for private dentistry emerged as a strong reason for remaining in the NHS, on the other, there was evidence that equity in access to dental treatment is still seen as an important principle. The implications of these findings in the context of recent discussion of the future of NHS dentistry are considered. Copyright © 2002 John Wiley & Sons, Ltd.
Design techniques for stated preference methods in health economics
Authors: Carlsson Fredrik , Martinsson Peter 
Published: March 2003

AbstractThis paper discusses different design techniques for stated preference surveys in health economic applications. In particular, we focus on different design techniques, i.e. how to combine the attribute levels into alternatives and choice sets, for choice experiments. Design is a vital issue in choice experiments since the combination of alternatives in the choice sets will determine the degree of precision obtainable from the estimates and welfare measures. In this paper we compare orthogonal, cyclical and D‐optimal designs, where the latter allows expectations about the true parameters to be included when creating the design. Moreover, we discuss how to obtain prior information on the parameters and how to conduct a sequential design procedure during the actual experiment in order to improve the precision in the estimates. The designs are evaluated according to their ability to predict the true marginal willingness to pay under different specifications of the utility function in Monte Carlo simulations. Our results suggest that the designs produce unbiased estimations, but orthogonal designs result in larger mean square error in comparison to D‐optimal designs. This result is expected when using correct priors on the parameters in D‐optimal designs. However, the simulations show that welfare measures are not very sensitive if the choice sets are generated from a D‐optimal design with biased priors. Copyright © 2002 John Wiley & Sons, Ltd.
Revisiting the axiom of completeness in health care
Authors: Ryan Mandy , Miguel Fernando San 
Published: March 2003

AbstractExperiments concerned with modelling individual preferences are based on the assumption of completeness i.e. it is assumed that individuals have well‐defined preferences for any choice they are presented with. However, this may not be the case for goods such as health care, where individuals are not used to making choices. If this assumption is violated, the large body of experimental economic literature eliciting patient preferences in health care may be challenged. This paper reports the results of a discrete choice experiment carried out to examine the assumption of complete preferences within health care. The tests carried out are based on the comparison of preferences for three different goods for which different levels of formed preferences are expected: a supermarket; dentist consultation and bowel cancer screening. The results do not provide sufficient evidence to support this hypothesis. However, further research is required before these results are generalised. Copyright © 2002 John Wiley & Sons, Ltd.
Measuring the value of time for methadone maintenance clients: willingness to pay, willingness to accept, and the wage rate
Authors: Borisova Natalia N. , Goodman Allen C. 
Published: March 2003

AbstractThree measures of the value of time – willingness to pay (WTP) for a reduction in travel time, willingness to accept (WTA) a monetary compensation to forgo it, and the wage rate – are evaluated and compared. WTP and WTA were estimated from the two‐part regressions of time price, using contingent valuation methods with primary survey data. Systematic differences are found in comparisons of WTP and WTA with the wage rate. Copyright © 2002 John Wiley & Sons, Ltd.
Analysis of an expanded width of albumin fraction by cellulose acetate membrane electrophoresis in IgA nephropathy urine before treatment
Authors: Machii Ryoko , Matsuda Kazuyuki , Hiratsuka Nobuo , Sugimoto Kayo , Hotta Osamu , Itoh Yoshihisa , Yoshida Hiroshi , Shiba Kiyoko 
Published: March 2003

AbstractCellulose acetate membrane electrophoresis with colloidal silver stain re‐vealed that the width of the albumin fraction in IgA nephropathy (IgAN) urine before treatment was significantly expanded. This phenomenon was not shown in IgAN urine after treatment or in non‐IgAN urine. There was a reverse correlation between the width of the albumin fraction and the albumin con‐centration in IgAN urine. By immuno‐fixation, Tamm‐Horsfall protein (THP) was located in the same position as the albumin band in IgAN urine before treatment; however, in the urine of a healthy subject it was located in the same position as α1‐globulin. By ELISA, the THP‐albumin complex concentration in IgAN urine before treatment was significantly higher than in the other two diseases. The width of the albumin fraction and the sodium ion concentra‐tion of the urine were significantly correlated. The THP/albumin ratio in IgAN urine before treatment was significantly higher than in the other two groups. This suggests that the characteristic expanded width of albumin found by immunofixation indicates a THP‐albumin complex, and that the sodium concentration of urine is involved in the formation of this complex. J. Clin. Lab. Anal. 17:37–43, 2003. © 2003 Wiley‐Liss, Inc.
Cellulose acetate membrane electrophoresis in the analysis of urinary proteins in patients with tubulointerstitial nephritis
Authors: Kubota Ryo , Machii Ryoko , Hiratsuka Nobuo , Hotta Osamu , Itoh Yoshihisa , Kobayashi Shizuko , Shiba Kiyoko 
Published: March 2003

AbstractUrinary proteins from 14 patients with tubulointerstitial nephritis were analyzed by cellulose acetate membrane electrophoresis. Urinary total protein concentrations were measured, and urinary 15 proteins (prealbumin, albumin, α1‐microglobulin, α1‐antitrypsin, α2‐macroglobulin, haptoglobin, retinol binding protein, transferrin, β2‐microglobulin, IgA, IgG, κ‐ and λ‐light chains, cystatin C, and lysozyme) were identified by the use of a rapid and highly sensitive colloidal silver staining reagent suited for use with cellulose acetate membranes, as reported previously by Matsuda et al. (J Clin Lab Anal 15:171–174, 2001; Clin Chem47:763–766, 2001) and Hiratsuka et al. (J Clin Lab Anal 10:403–406, 1996). We also analyzed urinary total protein concentration and urinary protein fractions according to the presence of acute or nonacute interstitial nephritis. In addition, the relationship between urinary protein fraction and complications of interstitial nephritis was analyzed. The goal of this work was to find a useful index for the diagnosis of tubulointerstitial nephritis. J. Clin. Lab. Anal. 17:44–51, 2003. © 2003 Wiley‐Liss, Inc.
TAP1 gene AccI polymorphism is associated with atopic bronchial asthma
Authors: Hang Liang‐Wen , Hsia Te‐Chun , Chen Wen‐Chi , Chen Huey‐Yi , Tsai Fuu‐Jen 
Published: March 2003

AbstractAsthma is a hyperresponsive airway disease that may involve inflammation responses. A transporter associated with the antigen processing 1 gene (TAP1) is involved in antigen processing, and is therefore considered to play a role in the pathogenesis of bronchial asthma. The aim of this study was to test whether the polymorphisms of the TAP1 gene are a genetic marker for susceptibility to bronchial asthma. A normal control group comprised of 43 healthy people, and 116 patients with allergic asthma were examined in this study. The polymorphism was detected by polymerase chain reaction (PCR)‐based restriction analysis. Associations between atopic bronchial asthma and TAP1 polymorphisms were evaluated. The results revealed no significant differences between normal individuals and asthmatics in regard to the TAP1 gene DpnII polymorphism (P=0.752). However, there was a significant difference between the control and asthma groups as regards the TAP1 gene AccI polymorphism (P=0.020). The odds ratio (OR) of GG homozygotes of the TAP1 AccI polymorphism was 229.8 compared with the AA homozygote group. The results show that the AccI polymorphism may be an indicator for atopic bronchial asthma. J. Clin. Lab. Anal. 17:57–60, 2003. © 2003 Wiley‐Liss, Inc.
Serum microminerals and the indices of lipid metabolism in an apparently healthy population
Authors: Abiaka Clifford , Olusi Samuel , Al‐Awadhi Adel 
Published: March 2003

AbstractSerum copper and zinc concentrations were measured in 560 apparently healthy Kuwaitis (238 males and 322 females) aged 15–80 years to assess micromineral effect on the indices of lipid metabolism. Following the recommended guidelines of the European Atherosclerosis Society (EAS) and the National Cholesterol Education Program Expert Panel (NCEPEP), the incidence of dyslipidemia was assessed from enzymatic assay data of triglycerides (TG), total cholesterol (TC), high‐density lipoprotein cholesterol (HDL‐C) and low‐density lipoprotein cholesterol (LDL‐C) concentrations. Males had significantly lower TC (P=0.029) and HDL‐C (P<0.0001) levels than females, while TG were significantly (P=0.023) lower in females. The prevalence of hypercholesterolemia, hypertriglyceridemia, elevated LDL‐C, and low HDL‐C levels were 35, 30, 22, and 13%, respectively. Copper did not correlate with zinc (r = –0.067, P = 0.135) but was positively associated with TC (r=0.196, P<0.0001), LDL‐C (r=0.134, P = 0.003), TG (r = 0.092, P=0.039), and age (r=0.281, P<0.0001). It is concluded that unlike in animal studies, copper excess in humans is associated with hyperlipidemia and therefore will predispose to atherosclerosis. J. Clin. Lab. Anal. 17:61–65, 2003. © 2003 Wiley‐Liss, Inc.
Reticulocyte parameters and hemoglobin F production in sickle cell disease patients undergoing hydroxyurea therapy
Authors: Borba R. , Lima C.S.P. , Grotto H.Z.W. 
Published: March 2003

AbstractHemoglobin F (HbF) is an effective inhibitor of HbS polymerization. Hydroxyurea (HU) is used to increase HbF synthesis and improve the clinical course of sickle cell disease (SCD) patients. We studied a series of laboratory parameters concerning HbF production and reticulocyte response, and compared data between two groups: 1) 13 SCD patients treated with HU, and 2) 33 untreated SCD patients. Higher values of Hb concentration, mean cell volume (MCV), mean cell hemoglobin (MCH), mean reticulocyte volume (MRV), HbF concentration, percentage of F‐cells, and amount of HbF/F‐cells were observed in the treated group of patients. There was no correlation between Hb and HbF elevations. The reticulocyte count, immature reticulocyte count, mean fluorescence index (MFI), and neutrophil count were significantly lower in treated patients. Taken together, these findings suggest that a decreased hemolytic process occurred in patients undergoing HU treatment. There was a significant correlation between MCV and HbF, between MRV and HbF, and between MRV and F‐cell in patients taking HU. These data indicate that macroreticulocytes correspond to F‐reticulocytes, and that an increase in MRV in SCD patients using HU may be an indirect signal of F‐cell production. The concentration of HbF/F‐cells was higher in patients treated with HU, but this increase apparently was independent of F‐cell production. Reticulocyte (RTC) parameters, as assessed by hematological analyzers, may be useful for following erythropoietic changes in patients receiving HU, and can indirectly indicate HbF and F‐cell production induced by HU therapy. J. Clin. Lab. Anal. 17:66–72, 2003. © 2003 Wiley‐Liss, Inc.
Voltage‐dependent K+ channel β subunits in muscle: Differential regulation during postnatal development and myogenesis
Authors: Grande Maribel , Suàrez Elisabeth , Vicente Rubén , Cantó Carles , Coma Mireia , Tamkun Michael M. , Zorzano Antonio , Gumà Anna , Felipe Antonio 
Published: March 2003

AbstractVoltage‐dependent potassium channels contribute to the electrical properties of nerve and muscle by affecting action potential shape and duration. The complexity of the currents generated is further enhanced by the presence of accessory β subunits. Here we report that while all Kvβ mRNA isoforms are present in rat brain, muscle tissues express only Kvβ1 (Kvβ1.1–Kvβ1.3) and Kvβ2, but not Kvβ3. Kvβ subunits were close regulated through post‐natal development in brain and striated muscle, as well as during myogenesis in the rat skeletal muscle cell line L6E9. While the alternatively spliced Kvβ mRNA products from Kvβ1 gene were differentially expressed, Kvβ2.1 was associated with myogenesis. These results show that Kvβ genes are strongly regulated in muscle and suggest a physiological role for voltage‐gated K+ channels during development and myotube formation. © 2003 Wiley‐Liss, Inc.