bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ethinylestradiol and testosterone have divergent effects on circulating IGF system components in adolescents with constitutional tall stature
Authors: Rooman Raoul P A , De Beeck Lieve Op , Martin Manou , van Doorn Jaap , Mohan Subburaman , Du Caju Marc V L 
Published: April 2005

Objective: Pharmacological doses of estrogens or testosterone are used to limit the final height of girls or boys with constitutional tall stature but the mechanism behind this growth inhibition is still debated. We therefore studied the changes in the circulating components of the insulin-like growth factor (IGF) system during high dose sex steroid therapy.
Design and methods: Twenty three girls and twenty boys with constitutional tall stature were treated with 100 μg ethinylestradiol per day or 250 mg testosterone ester every 14 days respectively. In 19 girls and 18 boys, the levels of IGF-I, free IGF-I, IGF-II, acid-labile subunit (ALS) and IGF binding proteins (IGFBP)-2 to -6 were measured before and 3–6 months after the start of therapy (group 1). In 18 girls and 11 boys, samples were collected at the end of therapy and 3 to 6 months afterwards (group 2). Fourteen girls and nine boys belonged to both groups. All parameters were measured by radioimmunoassay or ELISA.
Results: Levels of IGF-I were decreased significantly by estrogen treatment but remained unchanged during testosterone treatment. Free IGF-I decreased during estrogen treatment but increased during testosterone therapy. Estrogens increased IGF-II and testosterone reduced it. The important reduction of IGFBP-2 during estrogen therapy is not reproduced by androgen therapy, neither is the stimulation by estrogens of IGFBP-4. IGFBP-3 is not modulated by either sex steroid. We found that IGFBP-6 is up-regulated by testosterone but not by estrogens; the reverse is true for ALS, which increased during estrogen treatment but remained unchanged during testosterone treatment.
Conclusions: Our findings demonstrate that androgens and estrogens exert differential effects on the circulating levels of several IGF components.
Forskolin and dexamethasone synergistically induce aromatase (CYP19) expression in the human osteoblastic cell line SV-HFO
Authors: Watanabe Masatada , Ohno Shuji , Nakajin Shizuo 
Published: April 2005

Objective: Recent progress supports the importance of local estrogen secretion in human bone tissues to increase and maintain bone mineral density. In a previous study, we reported that the expression of aromatase (CYP19) is dexamethasone (Dex)-dependent and oncostatin M (OSM) increases the expression synergistically with Dex. In the present study, we examined the effects of forskolin (FSK) as another potential synergistic factor.
Results: Co-administration of 100 nM Dex and 10 μM FSK increased aromatase activity 4-fold compared with Dex alone. The results of reverse transcriptase (RT)-PCR suggest that the amount of CYP19 gene transcript was also up-regulated by FSK synergistically with Dex, and that promoter I.4, which is not activated by FSK alone, is activated by FSK synergistically with Dex. The results of RT-PCR also suggest that promoter II, which responds to FSK, was not activated even in the presence of FSK in SV-HFO. The promoter I.4 sequence that was transfected into SV-HFO was activated by FSK synergistically with Dex.
Conclusions: Synergistic up-regulation of aromatase activity, CYP19 gene transcript, and promoter I.4 activity were Dex-dependent and not up-regulated by FSK alone. The results of this work may form the basis of bone-specific estrogen-replacement therapy that increases the estrogen concentration in bone tissue only.
Glucose triggers protein kinase A-dependent insulin secretion in mouse pancreatic islets through activation of the K+ATP channel-dependent pathway
Authors: Thams Peter , Anwar Mohammad R , Capito Kirsten 
Published: April 2005

Objective: To assess the significance of protein kinase A (PKA) in glucose triggering of ATP-sensitive K+ (K+ATP) channel-dependent insulin secretion and in glucose amplification of K+ATP channel-independent insulin secretion.
Methods: Insulin release from cultured perifused mouse pancreatic islets was determined by radioimmunoassay.
Results: In islets cultured at 5.5 mmol/l glucose, and then perifused in physiological Krebs–Ringer medium, the PKA inhibitors, H89 (10 μmol/l) and PKI 6–22 amide (30 μmol/l) did not inhibit glucose (16.7 mmol/l)-induced insulin secretion, but inhibited stimulation by the adenylyl cyclase activator, forskolin (10 μmol/l). In the presence of 60 mmol/l K+ and 250 μmol/l diazoxide, which stimulates maximum Ca2+ influx independently of K+ATP channels, H89 (10 μmol/l) inhibited Ca2+-evoked insulin secretion, but failed to prevent glucose amplification of K+ATP channel-independent insulin secretion. In the presence of 1 mmol/l ouabain and 250 μmol/l diazoxide, which cause modest Ca2+ influx, glucose amplification of K+ATP channel-independent insulin secretion was observed without concomitant Ca2+ stimulation of PKA activity. In islets cultured at 16.7 mmol/l glucose, glucose (16.7 mmol/l)-induced insulin secretion in physiological Krebs–Ringer medium was augmented and now inhibited by H89 (10 μmol/l), implicating that culture at 16.7 mmol/l glucose may increase Ca2+-sensitive adenylyl cyclase activity and hence PKA activity. In accordance, Ca2+-evoked insulin secretion at 60 mmol/l K+ and 250 μmol/l diazoxide was improved, whereas glucose amplification of K+ATP channel-independent insulin secretion was unaffected.
Conclusions: Glucose may activate PKA through triggering of the K+ATP channel-dependent pathway. Glucose amplification of K+ATP channel-independent insulin secretion, on the other hand, occurs by PKA-independent mechanisms.
Nitric oxide mediates abnormal responsiveness of thyroid arteries in methimazole-treated patients
Authors: Ortega Joaquín , Vila José M , Mauricio María Dolores , Segarra Gloria , Medina Pascual , Martínez-León Juan B , Lluch Salvador 
Published: April 2005

Objective: We studied the intervention of nitric oxide (NO), prostacyclin and endothelium-derived hyperpolarizing factor (EDHF) in mediating responses to acetylcholine in thyroid arteries from euthyroid and methimazole-treated (MT) patients.
Design and methods: Branches of the superior thyroid artery were obtained from 19 euthyroid patients and 17 MT patients (euthyroid at the time of surgery) undergoing total thyroidectomy or hemithyroidectomy. Artery rings were suspended in organ baths for isometric recording of tension.
Results and conclusions: Acetylcholine caused endothelium-dependent relaxation of greater magnitude in arteries from MT patients (pD2 (−log EC50) values were 7.68±0.19 in euthyroid and 8.17±0.26 in MT patients, P <0.05). The relaxation was unaffected by indomethacin and was partially reduced by the NO-synthase inhibitor NG-monomethyl-l-arginine (l-NMMA). This reduction was higher in arteries from MT patients (50±6%) as compared with euthyroid patients (36±6%) (P <0.05). Inhibition of K+ channels using apamin combined with charybdotoxin or high K+ solution abolished the relaxation resistance to l-NMMA and indomethacin. The maximal contraction response to noradrenaline (as a percentage of the response to 100 mM KCl) was lower in MT than in euthyroid patients (57±10 and 96±8 respectively, P < 0.05). The hyporesponsiveness to noradrenaline in arteries from MT patients was corrected by l-NMMA. The results indicate that: (i) thyroid arteries from MT patients show an increased relaxation response to acethylcholine and a decreased contraction response to noradrenaline due to overproduction of NO; (ii) EDHF plays a prominent role in acetylcholine-induced relaxation through activation of Ca2+-activated K+ channels; (iii) the abnormal endothelium-dependent responses in arteries from MT patients are not corrected by medical treatment.
Interactions between the extracellular domain and the extracellular loops as well as the 6th transmembrane domain are necessary for TSH receptor activation
Authors: Neumann Susanne , Claus Maren , Paschke Ralf 
Published: April 2005

Objective: The molecular mechanisms of TSH receptor (TSHR) activation and intramolecular signal transduction are largely unknown. Deletion of the extracellular domain (ECD) of the TSHR results in increased constitutive activity, which suggests a self-inhibitory interaction between the ECD and the extracellular loops (ECLs) or the transmembrane domains (TMDs). To investigate these potential interactions and to pursue the idea that mutations in the ECD affect the constitutive activity of mutants in the ECLs or TMDs we generated double mutants between position 281 in the ECD and mutants in all three ECLs as well as the 6th TMD.Design: We combined mutation S281D, characterized by an impaired TSH-stimulated cAMP response, with the constitutively activatingin vivomutations I486F (1st ECL), I568T (2nd ECL), V656F (3rd ECL) and D633F (6th TMD). Further, we constructed double mutants containing the constitutively activating mutation S281N and one of the inactivating mutations D474E, T477I (1st ECL) and D633K (6th TMD).Results: The cAMP level of the double mutants with S281N and the inactive mutants in the 1st ECL was decreased below the level of the inactive single mutants, demonstrating that a constitutively activating mutation in the ECD cannot bypass disruption of signal transduction in the serpentine domain. In double mutants with S281D, basal and TSH-induced cAMP and inositol phosphate production of constitutively active mutants was reduced to the level of S281D.Conclusion: The dominance of S281D and the dependence of constitutively activating mutations in the ECLs on the functionally intact ECD strongly suggest that interactions between these receptor domains are required for TSHR activation and intramolecular signal transduction.
Mini-Mental State Examination is superior to plasma glucose concentrations in monitoring patients with suspected hypoglycaemic disorders during the 72-hour fast
Authors: Wiesli Peter , Schwegler Beat , Schmid Beat , Spinas Giatgen A , Schmid Christoph 
Published: April 2005

Objective: To determine whether systematic evaluation of cognitive function by the Mini-Mental State Examination (MMSE) allows the objective detection and documentation of cognitive deterioration in patients referred for evaluation of suspected hypoglycaemic disorders by the 72-h fast.
Design: Prospective case series.
Methods: In 50 patients referred for evaluation of suspected hypoglycaemic disorders, the MMSE score (maximum 30 points) was assessed at the start and at the end of the fast.
Results: The fast was terminated before 72 h in 14 patients because they developed neuroglycopenic symptoms due to hypoglycaemic disorders. Their MMSE score fell from a median of 29 points (range 20–30) at the beginning to 17 points (range 0–24) at the termination of the fast. The score dropped by ≥6 points in all patients with hypoglycaemic disorders. Median (range) plasma glucose concentration at the end of the fast was 2.1 (1.1–2.5) mmol/l. Thirty-six individuals developed no neuroglycopenic symptoms throughout the 72-h fast, their MMSE score remained between 27 and 30 throughout the fast and their median plasma glucose concentration dropped to 2.9 (2–3.6) mmol/l.
Conclusions: Systematic evaluation of cognitive function by the MMSE at the beginning and at the termination of the fast allows objective determination and documentation of the deterioration of the cognitive state in patients with hypoglycaemic disorders. A decline in the cognitive performance by ≥6 points in the MMSE score rather than a distinct plasma glucose concentration should be used as the criterion to terminate the prolonged fast before 72 h.
Supermarkets and their impacts on the agrifood system of Brazil: The competition among retailers
Authors: Farina Elizabeth M.M.Q. , Nunes Rubens , Monteiro Guilherme F. de A 
Published: April 2005

AbstractThis article proposes an explanation for evidence that challenges the received knowledge in relation to the advance of large supermarket chains in the Brazilian food market. It was thought that the large, more efficient chains would eliminate the traditional stores and the smaller supermarkets as well, based on price competition. However, the evolution of the food retail structure in Brazil shows growth in the number of traditional firms and independent supermarkets in the last nine years, with little evidence of loss of importance in food sales, especially as to the independent supermarkets whose share in food sales has grown. [EconLit citation: L100, L130, Q130.] © 2005 Wiley Periodicals, Inc. Agribusiness 21: 133–147, 2005.
Determining the causality between retail price and consumer demand in a linear function when demand‐shift variables are missing but wholesale prices are available
Authors: Kuiper W. Erno , Meulenberg Matthew T.G. 
Published: April 2005

AbstractA test procedure is proposed to test for the simultaneous nature of the relationship between price and quantity with respect to consumer demand of fresh products at the level of an individual retail chain. It is argued in the literature that, on the sector level, inverse demand systems in which quantities are exogenous and prices are the dependent variables are better able to describe consumer demand behavior in case of perishable products whose quantities may be treated as fully price inelastic in the short run. Nevertheless, applying our test procedure to six fresh vegetable products sold by a Dutch supermarket chain reveals that consumer demand for fresh products is better described by a simultaneous price–quantity relationship. [EconLit citations: C320, D420, Q110.] © 2005 Wiley Periodicals, Inc. Agribusiness 21: 167–176, 2005.
Branding and its consequences for German agribusiness
Authors: Hanf Jon H. , Kühl Rainer 
Published: April 2005

AbstractToday there is a clear consensus that customer orientation is a competitive necessity in order to survive in a market. In this article, the authors will analyze questions addressing brand management, especially the activities of retailers who are developing their own brands. As evidenced by the steady increase in market share for retail brands, nowadays consumers see little significant difference between retail brands and processor brands. Being the trustee of credence characteristics of food items, brands have to guarantee the correctness of their products throughout the whole food supply chain. In order to ensure this, vertical coordination mechanisms have to be installed. This is leading to competition among retail chains in the area of vertical coordination to ensure quality and to build brand equity. [EconLit citations: L220, L660, Q130.] © 2005 Wiley Periodicals, Inc. Agribusiness 21: 177–189, 2005.
Vertical contractual relations in the Italian beef supply chain
Authors: Mora Cristina , Menozzi Davide 
Published: April 2005

AbstractThis paper focuses on the Italian beef market and chain organization after the bovine spongiform encephalopathy (BSE) crises. This food scare, on the one hand, strongly affected consumers' attitude, making meat safety one of the most important issues of product quality for both consumers and retailers and, on the other hand, had important effects on the supply chain organization. The coming into force of the European Regulations (EC) No. 1760/2000 and No. 1825/2000 on beef labeling has partly led to a reshaping of the structure and organization of the Italian beef chain. The new relationships and contracts along the chain have been analyzed, and the strategies set up by the retailers to improve beef safety and quality and reinforce market segmentation have been discussed. The experience of the COOP Italia, the most important Italian large‐scale retailer, has been studied and discussed considering its chain organization and contract designing for beef products. [EconLit citations: L140, Q130, L220.] © 2005 Wiley Periodicals, Inc. Agribusiness 21: 213–235, 2005.
Effects of the Swiss retailers' strategy on the governance structure of the fresh food products supply chains
Authors: Réviron Sophie , Chappuis Jean‐Marc 
Published: April 2005

AbstractOn the initiative of the two main retailers, the structure of the Swiss food supply chains has changed in depth, with the construction of “normed systems,” characterized by quality insurance guarantees and of “partnerships” with alliances of producers and processing companies. These new forms of vertical organizations are different types of hybrid forms, according to New Institutional Economic theory. We highlight that these new organizations were chosen because of the lower degree of acceptance by the retailers of the asymmetry of information on quality, generally to their discredit, and in order to protect their reputation. Nevertheless, even in the case of products where the risk of acquiring a bad batch is particularly problematic for retailers, the latter do not seek to create bilateral governances systems directly with the producers, a situation that can lead to high tensions with the producers. [EconLit citations: Q130, D810.] © 2005 Wiley Periodicals, Inc. Agribusiness 21: 237–252, 2005.
Vertical integration and non‐linear price adjustments: The Spanish poultry sector
Authors: Ben‐Kaabia Monia , Gil José M. , Ameur Mehrez 
Published: April 2005

AbstractThe analysis of asymmetries in the price‐transmission mechanism at different levels of the marketing chain provides a good indicator of market efficiency in vertically related markets. The objective of this paper is to investigate the non‐linear adjustments of prices in the poultry marketing chain in Spain. The methodology used is based on the multivariate approach to specify and estimate a threshold autoregressive model. Price relationships at feed industry, producer, and retail levels are considered. Results indicate that, in the long run, price transmission is perfect and any supply or demand shocks are fully transmitted to all prices in the system. In the short run, price adjustments between the feed and the farmer levels are fairly symmetric and are representative of a cost‐push transmission mechanism. On the other hand, retailers benefit from any shock, whether positive or negative, that affects supply or demand conditions when price spreads are increasing, while price behavior is closely related to competitive markets when faced with declining price spreads. [EconLit citations: C320, Q130.] © 2005 Wiley Periodicals, Inc. Agribusiness 21: 253–271, 2005.
SOX2 anophthalmia syndrome
Authors: Ragge Nicola K. , Lorenz Birgit , Schneider Adele , Bushby Kate , de Sanctis Luisa , de Sanctis Ugo , Salt Alison , Collin J. Richard O. , Vivian Anthony J. , Free Samantha L. , Thompson Pamela , Williamson Kathleen A. , Sisodiya Sanjay M. , van Heyningen Veronica , FitzPatrick David R. 
Published: April 2005

AbstractHeterozygous, de novo, loss‐of‐function mutations in SOX2 have been shown to cause bilateral anophthalmia. Here we provide a detailed description of the clinical features associated with SOX2 mutations in the five individuals with reported mutations and four newly identified cases (including the first reported SOX2 missense mutation). The SOX2‐associated ocular malformations are variable in type, but most often bilateral and severe. Of the nine patients, six had bilateral anophthalmia and two had anophthalmia with contralateral microphthalmia with sclerocornea. The remaining case had anophthalmia with contralateral microphthalmia, posterior cortical cataract and a dysplastic optic disc, and was the only patient to have measurable visual acuity. The relatively consistent extraocular phenotype observed includes: learning disability, seizures, brain malformation, specific motor abnormalities, male genital tract malformations, mild facial dysmorphism, and postnatal growth failure. Identifying SOX2 mutations from large cohorts of patients with structural eye defects has delineated a new, clinically‐recognizable, multisystem disorder and has provided important insight into the developmental pathways critical for morphogenesis of the eye, brain, and male genital tract. © 2005 Wiley‐Liss, Inc.
Candidate gene analysis in human neural tube defects
Authors: Boyles Abee L. , Hammock Preston , Speer Marcy C. 
Published: April 2005

AbstractBiochemical and developmental pathways, mouse models, and positional evidence have provided numerous candidate genes for the study of human neural tube defects. In a survey of 80 studies on 38 candidate genes, few found significant results in human populations through case‐control or family‐based association studies. While the folate pathway has been explored extensively, only theMTHFR677C > T polymorphism was significant, and only in an Irish population. Developmental pathways such as the Wnt signaling pathway andHoxgenes have also been explored without positive results. More than 90 mouse candidates have been identified through spontaneous and knockout mutations, but only the T locus (mouseBrachyurygene) showed association in an initial study that was not confirmed on follow‐up. Positional candidates have been derived from cytogenetic evidence, but preliminary genomic screens have limited power due to small sample sizes. Future studies would increase their power to detect association by using more samples. In addition a clarification of the phenotype would be beneficial as many studies used different inclusion criteria. Incorporating several types of data could highlight better candidates, as would looking beyond the traditional sources for candidate genes. Recent studies of an energy metabolism gene (UCP2) and vitamin B metabolism (Transcoalbumin) have produced promising results. Utilizing other model organisms may also be beneficial, as in a recent study from a chick model of NTDs in NCAM1. New approaches combined with traditional methods and increased sample sizes will help prioritize human NTD candidate genes and clarify the complex etiology of this condition. © 2005 Wiley‐Liss, Inc.
The effect of fiber concentration on mechanical and thermal properties of fiber‐reinforced polypropylene composites
Authors: Houshyar S. , Shanks R. A. , Hodzic A. 
Published: April 2005

AbstractA novel composite material consisting of polypropylene (PP) fibers in a random poly(propylene‐co‐ethylene) (PPE) matrix was prepared and its properties were evaluated. The thermal and mechanical properties of PP–PPE composites were studied by dynamic mechanical analysis (DMA) and differential scanning calorimetry (DSC) with reference to the fiber concentration. Although, by increasing PP fiber concentration in PPE, no significant difference was found in melting and crystallization temperatures of the PPE, the storage, and the tensile and flexural modulus of the composites increased linearly with fiber concentrations up to 50%, 1.5, 1.0, 1.3 GPa, respectively, which was approximately four times higher than that for the pure PPE. There is a shift in glass transition temperature of the composite with increasing fiber concentration in the composite and the damping peak became flatter, which indicates the effectiveness of fiber–matrix interaction. A higher concentration of long fibers (>50% w/w) resulted in fiber packing problems, difficulty in dispersion, and an increase in void content, which led to a reduction in modulus. Cox–Krenchel and Haplin–Tsai equations were used to predict tensile modulus of random fiber‐reinforced composites. A Cole–Cole analysis was performed to understand the phase behavior of the composites. A master curve was constructed based on time–temperature superposition (TTS) by using data over the temperature range from −50 to 90°C, which allowed for the prediction of very long and short time behavior of the composite. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 2260–2272, 2005