bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ghrelin Secretion in Childhood Is Refractory to the Inhibitory Effect of Feeding
Authors: Bellone Simonetta , Castellino Nadia , Broglio Fabio , Rapa Anna , Vivenza Daniela , Radetti Giorgio , Bellone Jaele , Gottero Cristina , Ghigo Ezio , Bona Gianni 
Published: April 2004

Abstract
Ghrelin, a natural GH secretagogue, is predominantly produced by the stomach. Ghrelin has other actions including orexant activity, modulation of energy balance, and modulation of endocrine and nonendocrine functions. Ghrelin secretion is increased by fasting and energy restriction but decreased by food intake, glucose, insulin, and somatostatin. Ghrelin secretion does not seem to be a function of age; in fact, morning ghrelin levels after overnight fasting in prepubertal and pubertal children are similar to those in young adults. To clarify whether children and adults have the same sensitivity to the inhibitory effect of food intake, we studied the ghrelin response to a standardized light breakfast (SLB) in 10 prepubertal lean children whose results were compared with those recorded in 19 normal-weight adults. Basal ghrelin levels in children (median, 224.5; 25th to 75th percentile, 122.0–447.7 pg/ml) and adults (338.0; 238.0–512.0 pg/ml) were similar. SLB inhibited ghrelin levels in adults (263.0; 190.0–399.0 pg/ml). However, no change in ghrelin levels after SLB (206.5; 105.0–274.0 pg/ml) was recorded in children. Thus, food intake inhibits ghrelin secretion in adults but not in children. Ghrelin refractoriness to inhibition by food intake in children would reflect a peculiar functional profile of the ghrelin system in childhood.
Estrogen Controls Lipolysis by Up-Regulating α2A-Adrenergic Receptors Directly in Human Adipose Tissue through the Estrogen Receptor α. Implications for the Female Fat Distribution
Authors: Pedersen Steen B. , Kristensen Kurt , Hermann Pernille A. , Katzenellenbogen John A. , Richelsen Bjørn 
Published: April 2004

AbstractEstrogen seems to promote and maintain the typical female type of fat distribution that is characterized by accumulation of adipose tissue, especially in the sc fat depot, with only modest accumulation of adipose tissue intraabdominally. However, it is completely unknown how estrogen controls the fat accumulation.We studied the effects of estradiol in vivo and in vitro on human adipose tissue metabolism and found that estradiol directly increases the number of antilipolytic α2A-adrenergic receptors in sc adipocytes. The increased number of α2A-adrenergic receptors caused an attenuated lipolytic response of epinephrine in sc adipocytes; in contrast, no effect of estrogen on α2A-adrenergic receptor mRNA expression was observed in adipocytes from the intraabdominal fat depot.These findings show that estrogen lowers the lipolytic response in sc fat depot by increasing the number of antilipolytic α2A-adrenergic receptors, whereas estrogen seems not to affect lipolysis in adipocytes from the intraabdominal fat depot. Using estrogen receptor subtype-specific ligands, we found that this effect of estrogen was caused through the estrogen receptor subtype α.These findings demonstrate that estrogen attenuates the lipolytic response through up-regulation of the number of antilipolytic α2A-adrenergic receptors only in sc and not in visceral fat depots. Thus, our findings offer an explanation how estrogen maintains the typical female sc fat distribution because estrogen seems to inhibit lipolysis only in sc depots and thereby shifts the assimilation of fat from intraabdominal depots to sc depots.
Medical Cure of Plasma Cell Granuloma of the Thyroid Associated with Hashimoto’s Thyroiditis: A Case Report and Review
Authors: Laurent Silvana , Mouthon Luc , Longchampt Elisabeth , Roudaire Marie , Franc Sylvia , Krivitzky Alain , Cohen Régis 
Published: April 2004

AbstractPlasma cell granuloma (PCG) is a rare, benign inflammatory tumor composed of myofibroblasts, abundant plasma cells, and lymphocytes combined with collagen. A thyroid localization of PCG is extremely rare, and surgical therapy is indicated. We report the case of a 35-yr-old woman with a thyroid PCG, associated with Hashimoto’s thyroiditis, that was responsible for tracheal compression. Surgery was performed, but the thyroid could not be removed because of the fibrotic process. The patient was treated with corticosteroids and immunosuppressive therapy. Dyspnea and dysphagia improved within 1 month, whereas thyroid volume returned to normal within 3 yr. We also review other reports of thyroid PCG in the literature and discuss the differential diagnosis and treatment. Although the use of immunosuppressive therapy has never been reported for thyroid PCG until now, this treatment may represent a good alternative to surgery in life-threatening, unresectable PCG.
Cytoplasmic Expression of Fibroblast Growth Factor Receptor-4 in Human Pituitary Adenomas: Relation to Tumor Type, Size, Proliferation, and Invasiveness
Authors: Qian Zhi Rong , Sano Toshiaki , Asa Sylvia L. , Yamada Shozo , Horiguchi Hidehisa , Tashiro Takashi , Li Chiun Chei , Hirokawa Mitsuyoshi , Kovacs Kalman , Ezzat Shereen 
Published: April 2004

AbstractThe pathogenesis of pituitary adenomas remains unknown. A pituitary tumor-derived (ptd) isoform of fibroblast growth factor receptor-4 (ptd-FGFR4) has been implicated in the neoplastic process. To further understand the expression of FGFR4 in sporadic human pituitary adenomas, we studied 137 pituitary adenomas of various types (102 adenomas from Japanese patients and 35 adenomas from Canadian patients) and 10 nontumorous pituitaries using a polyclonal antiserum that recognizes the C terminus of FGFR4 and analyzed possible relationships among expression of FGFR4, patient nationality, tumor type, size, invasion, and the labeling index of the proliferation marker Ki-67 using the MIB-1 antibody. Cytoplasmic expression of FGFR4 protein was observed in 57.8% of Japanese cases and 62.8% of Canadian cases. FGFR4 reactivity was absent in all 10 normal adenohypophysial tissues examined. FGFR4 expression in pituitary adenomas was restricted mainly to the cytoplasm, a pattern similar to that seen in rat pituitary cells transfected with human ptd-FGFR4 but different from that of cells transfected with wild-type FGFR4, which displayed membrane localization of staining. Protein from primary human adenomas migrated as a 65-kDa species consistent with the predicted size of ptd-FGFR4. FGFR4 protein expression was frequently found in adenomas containing GH, ACTH, or FSH/LH and was also found in null cell adenomas, but reactivity was relatively rare in prolactin-containing adenomas in both Japanese and Canadian groups. The expression of FGFR4 protein was stronger in macroadenomas than in microadenomas (P = 0.02) and high levels of FGFR4 expression (moderate or greater density staining) were more frequently observed in macroadenomas than in microadenomas (P &lt; 0.05). High levels of FGFR4 expression also correlated significantly with the proliferation marker Ki-67 (P = 0.002) and tended (but not significantly) to be found in invasive tumors. These data are consistent with a role for ptd-FGFR4 in pituitary tumorigenesis in a majority of human pituitary adenomas. Moreover, detection of FGFR4 cytoplasmic staining may provide an ancillary diagnostic tool in the diagnosis of pituitary adenoma, particularly in equivocal cases.
A Novel Mutation in the Preprovasopressin Gene Identified in a Kindred with Autosomal Dominant Neurohypophyseal Diabetes Insipidus
Authors: Wahlstrom Justin T. , Fowler Michael J. , Nicholson Wendell E. , Kovacs William J. 
Published: April 2004

Abstract
Autosomal dominant neurohypophyseal diabetes insipidus (ADNDI) is a defect in free water conservation caused by mutations in the single gene that encodes both vasopressin (VP) and its binding protein, neurophysin II (NP II). Most of the human mutations in this gene have been in the portion encoding the NP molecule; the resultant abnormal gene products are believed to cause cellular toxicity as improperly folded precursor molecules accumulate in the endoplasmic reticulum. We identified a new American kindred with ADNDI and found a novel mutation in the VP molecule. A 78-yr-old man was noted to have hypotonic polyuria and plasma hyperosmolarity; the urinary concentration defect was reversed by administration of VP. His symptomatology dated to childhood, and his family history was consistent with autosomal transmission of the polyuric syndrome, with affected members in three generations, including several females. Affected individuals were found to be heterozygous for a 3-bp deletion in exon 1 of arginine VP (AVP)-NP II, predicting a deletion of phenylalanine 3 (known to be critical for receptor binding) in the VP nonapeptide. Neuro 2A cells stably transfected with the mutant AVP-NP construct showed increased rates of apoptosis as assessed by flow cytometric methods. These observations support the concept that cellular toxicity of abnormal AVP-NP gene products underlies the development of ADNDI, and the data further demonstrate that mutations affecting the AVP moiety can result in initiation of these pathological processes.
Dichloroacetate Therapy Attenuates the Blood Lactate Response to Submaximal Exercise in Patients with Defects in Mitochondrial Energy Metabolism
Authors: Duncan G. E. , Perkins L. A. , Theriaque D. W. , Neiberger R. E. , Stacpoole P. W. 
Published: April 2004

Abstract
We determined acute and chronic effects of dichloroacetate (DCA) on maximal (MAX) and submaximal (SUB) exercise responses in patients with abnormal mitochondrial energetics. Subjects (n = 9) completed a MAX treadmill bout 1 h after ingesting 25 mg/kg DCA or placebo (PL). A 15-min SUB bout was completed the next day while receiving the same treatment. After a 1-d washout, MAX and SUB were repeated while receiving the alternate treatment (acute). Gas exchange and heart rate were measured throughout all tests. Blood lactate (Bla) was measured 0, 3, and 10 min after MAX, and 5, 10, and 15 min during SUB. MAX and SUB were repeated after 3 months of daily DCA or PL. After a 2-wk washout, a final MAX and SUB were completed after 3 months of alternate treatment (chronic). Average Bla during SUB was lower (P &lt; 0.05) during both acute (1.99 ± 1.10 vs. 2.49 ± 1.52 mmol/liter) and chronic (1.71 ± 1.37 vs. 2.39 ± 1.32 mmol/liter) DCA vs. PL despite similar exercise intensities between conditions (∼75 and 70% maximal exercise capacity during acute and chronic treatment). Thus, although DCA does not alter MAX responses, acute and chronic DCA attenuate the Bla response to moderate exercise in patients with abnormal mitochondrial energetics.
Acoustic and Electroacoustic Characterization of Variable-Charge Mineral Suspensions
Authors: Guerin Marianne , Seaman John C. , Lehmann Charlotte , Jurgenson Arthur 
Published: April 2004

AbstractAcoustic and electroacoustic measurements of particle-size distribution (PSD) and zeta potential (ζ potential), respectively, were used to obtain in situ measures of the effects of suspension concentration and pH on interactions between mixed-charge clays and clay minerals from a highly weathered sediment. Measurements were obtained in concentrated suspensions as a function of weight fraction and as a function of pH during titrations. Standard dispersion and centrifugation methods were used to obtain a comparative measure of PSD. Thermogravimetric analysis and X-ray diffraction patterns were used to obtain semi-quantitative and descriptive analyses, respectively, of the sediment, which is composed of Fe oxide minerals, kaolinite, gibbsite, quartz, crandallite, chlorite and traces of other clay minerals. Acoustic measurements showed that the PSD of the clay fraction varied with suspension concentration, and electroacoustic measurements showed the ‘bulk’ ζ potential increased in absolute value as the suspension concentration decreased. Titration results were also sensitive to suspension concentration. Acoustic measurements indicated that the suspensions became unstable at ∼pH 7.5–8.0, as the attenuation spectra changed character near this pH and the calculated PSD shifted to a larger particle size. This pH value is near the points of zero charge of goethite and gibbsite, as verified by titrations on mineral standards. The results confirm the central role oxide minerals play in regulating clay mineral interactions in highly weathered sediments, and indicate that the average ζ potential of a suspension may be a poor indicator of controls on suspension stability.
The Ordering of HDTMA in the Interlayers of Vermiculite and the Influence of Solvents
Authors: Slade Phil G. , Gates Will P. 
Published: April 2004

AbstractX-ray basal reflections of several HDTMA-vermiculites show that when these contain co-adsorbed molecules of HDTMA-Br, their interlayer spacings are ∼29.5 Å. After HDTMA-Br has been leached out with ethanol, spacings decrease to ∼26 Å, but when exposed to toluene vapor the spacings increase to ∼36 Å, and to ∼45 Å in toluene liquid. Transmission X-ray diffraction photographs of HDTMA-vermiculites, both with and without co-adsorbed HDTMA-Br, indicate that they have highly ordered interlayer structures. The structure of HDTMA-Br-free vermiculite flakes is more open with the interlayer cations arranged in a 3a × b superstructure. In the HDTMA-Br containing HDTMA vermiculite flakes, HDTMA-Br molecules occupy interstitial positions between the HDTMA cations. Swelling in toluene vapor does not disorder the 2-dimensional arrangement of interlayer cations, but disorder does occur in toluene liquid. In toluene vapor, the aliphatic chains of the cations remain partially interdigitated, but in toluene liquid the interdigitation disappears. In response to the layer-charge density, the organization of the interlayer HDTMA units is caused by the self-assembly process responsible for hydrocarbon close packing.
Crystal-Chemical Changes in an Oxidative Weathering Front in a Georgia Kaolin Deposit
Authors: Schroeder Paul A. , Pruett Robert J. , Melear Nathan D. 
Published: April 2004

AbstractThe Eocene Huber Formation, exposed in the CFI Hall mine south of Irwinton, in Wilkinson County, Georgia, displays colored zones that are a consequence of an oxidative weathering front. These zones vary from very light gray (gray) to pinkish white (pink) to very pale yellow (cream) (Munsell N8, 5YR 8/2 and 2.5Y 8/2, respectively) with increasing degree of oxidation. A representative sample from each zone was collected and analyzed for its chemical, crystallographic and Raman spectroscopic properties. The comparison of these genetically related samples allowed for a quantitatively accurate assessment of anatase’s contribution to the total TiO2 content. All samples contain ∼1.5 wt.% TiO2. Progressing from gray to pink to cream, anatase contents range from half to nearly all the TiO2. The a lattice parameter for anatase is constant in all three kaolins (3.7916 Å), suggesting a constant 4.6 mol.% isomorphous substitution of Fe for Ti.Phase characterization and mass-balance considerations of the gray, pink and cream kaolins indicate that ilmenite and pyrite are precursor Ti- and Fe-bearing phases in the gray kaolin that undergo oxidation. Pseudorutile is a proposed intermediate phase resulting from the anodic corrosion of ilmenite. Hematite, goethite and anatase are the dominant end-products via dissolution-precipitation from the reactants pyrite and pseudorutile. The removal of Fe sulfides and organic matter and addition of hematite and goethite causes kaolin colors to change from gray to pink. Oxygen diffusing from groundwater in permeable overlying and underlying formations facilitates a process that probably involves aerobic and anaerobic bacteria that utilize Fe from pyrite, hematite and goethite. We postulate that the end result is the mobilization of Fe by siderophores and a kaolin color change from pink to cream.
Formation and Properties of a Continuous Crystallinity Series of Synthetic Ferrihydrites (2- to 6-line) and their Relation to FeOOH Forms
Authors: Schwertmann Udo , Friedl Josef , Kyek Andreas 
Published: April 2004

AbstractFerrihydrite is a poorly crystalline Fe oxide of which 2-(XRD)line and 6-line varieties are commonly used in experiments, although species with intermediate numbers of peaks have been found in nature. To simulate nature, we synthesized two continuous series of ferrihydrites with between 2 and 6–7 peaks at room temperature in two different ways: (1) by varying the rate of hydrolysis of an Fe(NO3)3 solution (HR series); and (2) by oxidizing an FeCl2 solution containing up to 73 mmol Si/L (Si series), both at pH 7. Mössbauer spectra at 4.2 K showed that the ferrihydrites of the HR series had a constant magnetic hyperfine field (Bhf) at 4.2 K of 48.8 T whereas Bhf in the Si series dropped from 49.4 to 46.7 T as the Si content of the ferrihydrites increased from 0 to 74.7 g/kg of Si. Temperature scans between 4 and 170 K illustrate that the magnetic order breaks down at a temperature which is lower the higher the hydrolysis rate and the Si concentration in the ferrihydrite.
Selective Expression of Heteromeric AMPA Receptors Driven by Flip–Flop Differences
Authors: Brorson James R. , Li Dongdong , Suzuki Takeshi 
Published: April 2004

Initial models of AMPA receptor assembly postulated the unrestricted stochastic association of individual subunits. The low Ca2+permeability and nonrectified current–voltage relationship of most native AMPA receptors were ascribed to dominant effects of the glutamate receptor 2 (GluR2) subunit. A recent model, however, proposes instead the preferred assembly of GluR1 and GluR2 subunits into tetrameric complexes as pairs of identical heteromeric dimers. To compare unrestricted versus selective models of GluR1 and GluR2 assembly, these subunits, in both flip and flop isoforms, were expressed in varying ratios in human embryonic kidney 293 cells.Coexpression of pairs of wild-type subunits produced expression of a predominance of heteromeric over homomeric receptors. Only a single functional type of heteromeric receptor was observed, indicating a pattern of apparent dominance not only of GluR2 for ion selectivity, but also of the flip isoform for receptor desensitization. Expression of wild-type GluR1 flip, however, with a mutant form of the same subunit carrying an arginine residue at the glutamine/arginine site (GluR1Rflip) demonstrated a lack of dominance of GluR1Rin determination of ion selectivity, whereas expression of GluR1Rflip with GluR1 flop reproduced the pattern of apparent complete dominance. Together, the data support the selective expression of heteromeric receptors and are compatible with an equilibrium model of assembly of tetramers as pairs of identical heteromeric dimers. Expression of co-assemblies of the flip and flop isoforms, like that of the GluR1 and GluR2 subunits, is strongly favored over that of homomeric assemblies.
Simulation of helical flows in microchannels
Authors: Schönfeld Friedhelm , Hardt Steffen 
Published: April 2004

AbstractHelical flows are investigated in structured microchannels with regard to micromixing by means of computational fluid dynamics (CFD). In the case of bas‐relief structured channels the numerical results are found to be in good agreement with experimental findings. The magnitude of the transverse flow is computed for various Reynolds numbers and for different geometries including channels with bas‐relief structures on two opposite walls. Transverse flows in structured microchannels are compared to secondary flow patterns in curved square channels. The corresponding helical flows are analyzed for Dean numbers ranging from 1 to 900. Special attention is paid to the occurrence of additional vortices close to the center of the outer channel wall. Based on the results a new type of micromixer is proposed that relies on the transition of the secondary flow pattern from two to four vortices. © 2004 American Institute of Chemical Engineers AIChE J, 50: 771–778, 2004
Melt grafting of n‐butyl methacrylate onto poly(vinyl chloride): Synthesis and characterization*
Authors: Maiti Ajit K. , Choudhary Manjeet S. 
Published: April 2004

AbstractThe graft copolymerization of n‐butyl methacrylate monomer onto compounded poly(vinyl chloride) was carried out by melt‐mixing process in a Brabender plasticorder (BPCR) using a free‐radical initiator. The reaction conditions such as initiator and monomer concentration, shear rate (rpm), residence time, and temperature were optimized in the mixing head of BPCR attached to a torque rheometer. The graft copolymers were Soxhlet extracted with cyclohexane and were characterized by intrinsic viscosity, FTIR, and 13C‐NMR spectroscopy. A maximum of 14% grafting was obtained. The graft copolymer showed significant improvement in processibility and both thermal and mechanical properties. Scale‐up studies of the optimized recipe were carried out in a single‐screw extruder for commercial trials/evaluation. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2442–2449, 2004
Morphology and thermodynamic analysis of composite polymer particles prepared by soap‐free emulsion polymerization in the presence of poly(methyl methacrylate) and polystyrene as biseeds
Authors: Pang Xingshou , Cheng Guoxiang , Lu Shulai 
Published: April 2004

AbstractBiseeds emulsion polymerization was investigated with poly(methyl methacrylate) (PMMA) and polystyrene (PSt) as biseeds and styrene (St) as second‐stage monomer, as well as with thermodynamic analysis; namely, the principle of minimum interfacial free‐energy change was utilized to explain the competitiveness of different seeds for second‐stage monomer and the final equilibrium morphology of composite polymer particles. The experimental results indicated the polymeric particles prepared had bimodal size distribution and the PMMA seed particles showed a higher chance of obtaining St than that of the PSt seed particles, which was in agreement with the computational outcome by the principle of minimum interfacial free‐energy change. Owing to the kinetic factors, the equilibrium morphology could not be reached in the experiments. However, the results demonstrated that double or multiple seeds emulsion polymerization could be used as a model experiment to study the morphology of polymer particle and the morphological prediction. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2675–2680, 2004
The central region of NGC 3077: ground‐based photometry and age of bright ‘starlike’ objects
Authors: Notni P. , Karachentsev I.D. , Makarova L.N. 
Published: April 2004

AbstractWe present UBVIC photometry of starlike objects in the central region of NGC 3077. The colour‐colour and colour‐magnitude diagrams of the objects are discussed. Many of the objects under consideration, starlike from the ground, are probably dense young star clusters (super star clusters, SSC). Ages spreading over ∼4 to ∼150 Myr are estimated for most of these objects. Sakai and Madore (2001) found enhanced star formation ∼30–125 Myr ago also in the halo of this galaxy; thus, high star forming activity has occurred within the entire galaxy (centre and halo) since ∼130…150 Myr. Having ended in the outer regions about 30 Myr ago, it is going on near the centre with full vigour. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)