bluuebunny/crossref_metadata_2025_split huggingface dataset:
Endogenous expression and localization of myostatin and its relation to myosin heavy chain distribution in C2C12 skeletal muscle cells
Authors: Artaza Jorge N. , Bhasin Shalender , Mallidis Con , Taylor Wayne , Ma Kun , Gonzalez‐Cadavid Nestor F. 
Published: October 2004

AbstractMyostatin is a negative regulator of skeletal muscle growth. We have previously reported that recombinant myostatin protein inhibits DNA and protein synthesis in C2C12 cells. Our objective was to assess if C2C12 cells express myostatin, determine its sub‐cellular localization and the developmental stage of C2C12 cells in which myostatin mRNA and protein are expressed. To study the endogenous expression of myostatin, C2C12 myoblasts were allowed to progress to myotubes, and changes in the levels of endogenous myostatin mRNA expression were determined by RT–PCR. The myostatin protein and the two major myosin heavy chain (MHC) isoforms (MHC‐I and ‐II) were determined by Western blot. Confirmation of the relative MHC expression patterns was obtained by a modified polyacrylamide gel electropheretic (PAGE) procedure. Imunofluorescence staining was employed to localize the site of myostatin expression and the relative distribution of the MHC isoforms. Co‐expression of these proteins was studied using a dual staining approach. Expression of myostatin mRNA was found in myotubes but not in myoblasts. Myostatin protein was seen in most but not all, of the nuclei of polynucleated fibers expressing MHC‐II, and myostatin was detected in the cytoplasm of myotube. The localization of myostatin protein in myotube nuclei was confirmed by Western blot of isolated nuclear and cytoplasmic fractions. Incubation of C2C12 myotubes with graded doses of dexamethasone dose‐dependently increased the intensity of nuclear myostatin immunostaining and also resulted in the appearance of cytoplasmic expression. In conclusion, myostatin was expressed mostly in C2C12 myotubes nuclei expressing MHC‐II. Its predominant nuclear localization suggests that it may play a role in transcriptional regulation. J. Cell. Physiol. 190: 170–179, 2002. © 2002 Wiley‐Liss, Inc.
Recombinant transmembrane CD59 (CD59‐TM) confers complement resistance to GPI‐anchored protein defective melanoma cells*
Authors: De Nardo Chiara , Fonsatti Ester , Sigalotti Luca , Calabrò Luana , Colizzi Francesca , Cortini Enzo , Coral Sandra , Altomonte Maresa , Maio Michele 
Published: October 2004

AbstractProtectin (CD59) is a glycosylphosphatidylinositol (GPI)‐anchored cell membrane glycoprotein, broadly expressed on melanocytic cells, that represents the main restriction factor of complement (C)‐mediated lysis of human melanoma cells. Levels of CD59 expression may impair the clinical efficacy of C‐activating monoclonal antibodies (mAb); thus, we investigated the molecular mechanisms underlying the lack of CD59 expression in selected melanoma cells. Serological and biochemical analyses showed that MeWo melanoma cells expressed CD59 neither at cell surface nor at cytoplasmic levels; however, no critical mutations were identified in their CD59 mRNA. Consistently, MeWo CD59 cDNA (MeWo‐CD59) was appropriately translated when transfected into the CD59‐positive Mel 100 melanoma cells, and into the CD59‐negative Nalm‐6 pre‐B leukemia cells that acquired resistance to C. In contrast, transfection of MeWo cells with CD59 cDNA from Mel 275 melanoma cells did not induce CD59 expression; however, their transfection with the CD59‐TM chimeric construct, obtained by replacing the GPI‐anchoring signal of MeWo‐CD59 with the transmembrane tail of the human low‐density lipoprotein receptor, induced the expression of a C‐protective transmembrane form of CD59. These data, together with the absent expression of additional GPI‐anchored proteins (i.e., CD55), suggest that defects in the biosynthesis and/or processing of GPI‐anchored proteins underlie the lack of CD59 expression in MeWo cells. Further unveiling of the molecular mechanism that turns off CD59 expression in human melanoma cells will help to set‐up more effective therapeutic strategies utilizing C‐activating mAb in melanoma patients. J. Cell. Physiol. 190: 200–206, 2002. © 2002 Wiley‐Liss, Inc.
Regulation of RNA polymerase II activity by CTD phosphorylation and cell cycle control
Authors: Oelgeschläger Thomas 
Published: October 2004

AbstractThe carboxyl‐terminal domain (CTD) of the largest subunit of mammalian RNA polymerase II (RNAP II) consists of 52 repeats of a consensus heptapeptide and is subject to phosphorylation and dephosphorylation events during each round of transcription. RNAP II activity is regulated during the cell cycle and cell cycle‐dependend changes in RNAP II activity correlate well with CTD phosphorylation. In addition, global changes in the CTD phosphorylation status are observed in response to mitogenic or cytostatic signals such as growth factors, mitogens and DNA‐damaging agents. Several CTD kinases are members of the cyclin‐dependent kinase (CDK) superfamily and associate with transcription initiation complexes. Other CTD kinases implicated in cell cycle regulation include the mitogen‐activated protein kinases ERK‐1/2 and the c‐Abl tyrosine kinase. These observations suggest that reversible RNAP II CTD phosphorylation may play a key role in linking cell cycle regulatory events to coordinated changes in transcription. J. Cell. Physiol. 190: 160–169, 2002. © 2002 Wiley‐Liss, Inc.
Borderline cystic tumors of the ovary: Gray‐scale and color Doppler sonographic findings
Authors: Pascual M. Angela , Tresserra Francisco , Grases Pedro J. , Labastida Ramon , Dexeus Santiago 
Published: October 2004

AbstractPurposeThe aim of the study was to determine the value of gray‐scale and color Doppler sonography in distinguishing borderline cystic tumors (BCTs) from benign cysts and malignant tumors of the ovary.MethodsThe gray‐scale and color Doppler sonographic features of 383 ovarian lesions in 374 nonpregnant women were retrospectively studied. Sonography was performed transvaginally for all but 7 lesions, which were imaged suprapubically. All of the lesions were surgically resected via laparoscopy or laparotomy.ResultsThe histopathologic diagnoses were 27 BCTs, 35 ovarian carcinomas, and 321 benign cysts. Sonography diagnosed 24 (89%) of 27 BCTs as malignant lesions. Patients with BCTs, were younger than those with ovarian cancer (p < 0.001). BCTs showed intracystic papillae in 17 cases (63%), diffuse internal echoes in 11 (41%), intracystic septa in 8 (30%), a heterogeneous echo pattern in 7 (26%), and a solid pattern in 4 (15%). BCTs showed blood flow in 24 cases (89%) and lower pulsatility and resistance indices (RI) compared with benign lesions (p < 0.001 for both). Multivariate analysis revealed intracystic papillae as the only independent predictor of BCTs (p < 0.001).ConclusionsWhen a cystic mass has papillae, this is the only abnormal finding detected by gray‐scale transvaginal sonography, and color Doppler imaging shows low RI values within the mass, a BCT should be suspected. © 2002 John Wiley & Sons, Inc. J Clin Ultrasound 30:76–82, 2002; DOI 10.1002/jcu.10028
Prenatal sonographic diagnosis of diastrophic dwarfism
Authors: Tongsong Theera , Wanapirak Chanane , Sirichotiyakul Supatra , Chanprapaph Pharuhas 
Published: October 2004

AbstractA healthy 27‐year‐old pregnant woman underwent sonographic examination because her uterine size was large for 20 weeks’ menstrual age. Sonograms showed short fetal limbs with hitchhiker thumbs and toes, thoracic scoliosis, clubbed feet, and polyhydramnios. The ossification of all bony structures appeared normal, and there was no evidence of fractures. On the basis of these sonographic findings, we diagnosed skeletal dysplasia and short‐limbed dwarfism, most likely diastrophic dwarfism. We counseled the parents, and the pregnancy was continued. At 37 weeks menstrual age, the patient vaginally delivered a male infant that weighed 2,560 g. The infant survived with respiratory support during his first few days of life. Postnatal physical and radiologic examinations confirmed the prenatal diagnosis of diastrophic dwarfism. Sonography is the modality of choice for prenatal detection of diastrophic dwarfism. © 2002 John Wiley & Sons, Inc. J Clin Ultrasound 30:103–105, 2002; DOI 10.1002/jcu.10032
Sonographic examination of the oral phase of swallowing: Bolus image enhancement
Authors: Casas Michael J. , Seo Anna H. , Kenny David J. 
Published: October 2004

AbstractPurposeThe purpose of this study was to evaluate the ability of 4 liquid boluses to enhance pixel brightness and the ease with which the boluses could be identified during the sonographic evaluation of oral swallowing in healthy young adults.MethodsTen healthy adult volunteers (5 men and 5 women), ranging in age from 21 to 31 years, underwent sonographic evaluation of the oral phase of swallowing while sitting in their usual feeding position. We compared the ability of the 4 following liquids to improve sonographic visualization of swallowing with that of water: a carbonated cola beverage, 5.0 ml of Thick‐It in 120 ml of water, 2.5 ml of Thick‐It in 120 ml of water, and 7.5 ml of confectioners' sugar in 120 ml of water. Water was used as a control. In each case, 5 ml of the liquid was introduced into the subject's oral cavity using a syringe, and the subject was instructed to swallow. Digitized still images and recorded video sequences of sonographic examinations of the swallowing were analyzed. The brightness of the bolus image on selected digitized video frames was measured digitally using Image Analyst software. Pixel brightness within selected regions of interest for each of the test liquids was statistically compared with that for water. Seven clinicians rated the visualization of each test liquid and water on paired sonographic videotape sequences. These ratings and the level of agreement between them were statistically tested.ResultsOnly the carbonated cola beverage demonstrated statistically greater pixel brightness than that of water on digitized video frames (p = 0.01), whereas both cola (with a moderate inter‐rater agreement, κ = 0.50) and 5.0 ml Thick‐It mixed with 120 ml of water (with a fair inter‐rater agreement, κ = 0.24) were significantly better visualized on sonographic video sequences.ConclusionsThe digital still‐frame analysis confirmed the clinicians' ratings of bolus visualization on real‐time sonography, but dynamic sonography is more important than still frames in assessing sonographic swallow media because the dynamic images more closely parallel what is seen in clinical practice. Future investigations of sonographic contrast agents for use in the examination of the oral phase of swallowing should use both static digital (still‐frame) and dynamic (real‐time) assessment methods, as well as expert reviewers. © 2002 John Wiley & Sons, Inc. J Clin Ultrasound 30:83–87, 2002; DOI 10.1002/jcu.10034
Isolation of the peri‐acrosomal plasma membrane protein D40 enriched fraction from guinea pig spermatozoa using a monoclonal antibody
Authors: Ilayperuma I. 
Published: October 2004

AbstractMembrane fragments were obtained from guinea pig spermatozoa by mechanical shearing. A membrane‐enriched fraction was separated from other cellular debris, mainly sperm nuclei and tails, by centrifugation on 20% Ficoll 70 solution. Peri‐acrosomal plasma membrane protein, D40, enriched fraction was separated from this membrane preparation using a mouse monoclonal antibody to D40 attached to magnetic beads. Enrichment of D40 antigen in this fraction was demonstrated by western blotting. The method provides a preparative route to a membrane, the constituents of which play an important role in sperm recognition of the zona pellucida and the acrosome reaction. Some constituents of the peri‐acrosomal plasma membrane over the equatorial segment of the acrosome may also play a role in sperm docking with the oocyte plasma membrane and fusion of the two cells. J. Exp. Zool. 292:402–410, 2002. © 2002 Wiley‐Liss, Inc.
Characterization and quantification of yolk proteins in the lobster, Homarus americanus
Authors: Tsukimura Brian , Waddy Susan L. , Vogel Jacalyn M. , Linder Colby J. , Bauer Daniel K. , Borst David W. 
Published: October 2004

AbstractYolk protein (vitellin, Vn) and its precursor (vitellogenin, Vg) were isolated and characterized in the ovary and hemolymph, respectively, of the adult female lobster, Homarus americanus. Vn had a molecular mass of 360 kDa when analyzed by gel filtration. When analyzed by SDS‐PAGE, Vn had six bands (110, 105, 94, 90, 81, and 78 kDa). An anti‐Vn antiserum was developed using purified Vn, and the antiserum was used to detect Vn and Vg by ELISA and western blot techniques. ELISA analysis of hemolymph proteins separated by gel filtration indicated that Vg was similar in mass to Vn (360 kDa). However, western blots of hemolymph proteins separated by SDS‐PAGE indicated that Vg contained a pair of protein subunits, 194 kDa and 179 kDa. Furthermore, the elution profiles of Vn and Vg from anion exchange chromatography indicated that Vg had a more negative charge. Thus, Vg appears to be processed after its uptake by the ovary to form Vn. Vg was undetectable in hemolymph from adult males by either ELISA or by western blot analysis. However, hemolymph levels of Vg in adult females increased 40‐fold during the reproductive cycle, rising from 18 μg/mL in ovarian stage II to 789 μg/mL at stage V. This increase correlates well with oocyte growth during the cycle. Hence, this method may be useful for studying the regulation of lobster vitellogenesis. J. Exp. Zool. 292:367–375, 2002. © 2002 Wiley‐Liss, Inc.
Effects of chemical anoxia on adrenergic responses of goldfish hepatocytes and the contribution of α‐ and β‐adrenoceptors
Authors: Manzl Claudia , Schubert Markus , Schwarzbaum Pablo J. , Krumschnabel Gerhard 
Published: October 2004

AbstractAdrenergic responses during normoxia and chemical anoxia were investigated in anoxia‐tolerant hepatocytes from the goldfish, Carassius auratus. Epinephrine‐stimulated glucose release was unaltered after 1 hr of chemical anoxia, the concentration of epinephrine required for half maximal stimulation of glucose release (K) ranging from 0.62 × 10–8 to 2.05 × 10–8 M. Similarly, the maximum rate of glucose release caused by hormonal stimulation was not affected by chemical anoxia. In anoxic goldfish hepatocytes [Ca2+]i remained constant in nonstimulated cells but could be elevated by addition of epinephrine. The magnitude of this [Ca2+]i‐increase was dependent on the concentration of the catecholamine and this dependency was similar under normoxia (K = 1.17 × 10–8 M) and chemical anoxia (K = 1.15 × 10–8 M), as was the percentage of cells responding (77%) and displaying oscillatory [Ca2+]i response patterns (60%) after epinephrine addition, although the frequency of [Ca2+]i oscillations was significantly lower in anoxic cells. To analyze a possible shift in the importance of α‐ and β‐adrenoceptors during chemical anoxia, the effect of phentolamine and propranolol, α‐ and β‐adrenergic antagonists respectively, on epinephrine‐stimulated glucose release was studied. Application of the α‐antagonist caused a dose‐dependent reduction of glucose‐release which was similar under both conditions, whereas the sensitivity to the β‐antagonist was lowered after chemical anoxia. Taken together these results provide evidence that during chemical anoxia goldfish hepatocytes remain responsive to adrenergic stimulation and that there is a partial shift regarding the contribution of α‐ and β‐adrenergic pathways to the induction of cellular glucose release stimulated by epinephrine. J. Exp. Zool. 292:468–476, 2002. © 2002 Wiley‐Liss, Inc.
Costs of anorexia during pregnancy in a viviparous snake (Vipera aspis)
Authors: Lourdais Olivier , Bonnet Xavier , Doughty Paul 
Published: October 2004

AbstractSpontaneous anorexia has been documented in various animal species and is usually associated with activities competing with food intake. In natural conditions, most female aspic vipers (Vipera aspis) stop feeding during the two months of pregnancy. We carried out a simple experiment on 40 pregnant females to determine whether anorexia was obligatory or facultative, and to investigate the energetic consequence of fasting on post‐partum body condition and litter traits. Three diet treatments were applied during gestation: no food, one feeding occasion, and two feeding occasions. Twelve nonpregnant, unfed females were used as a control group. Most gravid females accepted captive mice during gestation, suggesting that anorexia reported in the field was a side effect of the tremendous changes in activity pattern associated with pregnancy. Mass loss was high for unfed reproductive females, indicating high energy expenditure associated with embryo maintenance. Prey consumption allowed compensation for metabolic expenditure and enhanced post‐partum female body condition, but had no effects on litter characteristics. The magnitude of the metabolic expenditure during gestation appeared to be independent of fecundity. J. Exp. Zool. 292:487–493, 2002. © 2002 Wiley‐Liss, Inc.
MRA is useful as a follow‐up technique after endovascular repair of aortic aneurysms with nitinol endoprostheses
Authors: Ayuso Juan R. , de Caralt Teresa M. , Pages Mario , Riambau Vicente , Ayuso Carmen , Sanchez Marcelo , Real María I. , Montaña Xavier 
Published: October 2004

AbstractPurposeTo evaluate whether MR angiography (MRA) is a useful tool for the follow‐up of aortic aneurysms treated with nitinol endoluminal grafts.Materials and MethodsWe examined 28 patients treated with nitinol endovascular stents to repair an aortic aneurysm with CT angiography (CTA) and MRA. Eleven patients (group 1) underwent an MRA after a positive CTA for endoleak was observed. Afterwards, 17 patients (group 2) were scheduled for both follow‐up examinations. The kind of endoleak that occurred and the maximum aortic diameter were compared. The sensitivity of CTA relative to MRA for detecting endoleaks in group 2 was calculated. Signal‐to‐noise ratios (SNRs) were measured in the aortoiliac lumen at the arterial phase in, above, and below the endoprostheses. Student's t‐test was used to compare aneurysm dimensions and SNR measurements.ResultsThree type III leaks were correctly assessed at both examinations; however, CTA was less sensitive (50%) than MRA in depicting type II or unclassified leaks. No differences in aneurismal size were observed between the two examinations or between arterial SNRs observed in or out of the devices.ConclusionMRA can provide all relevant information necessary for the follow‐up of patients treated with nitinol endoprostheses, and performs better than CTA in detecting endoleaks. J. Magn. Reson. Imaging 2004;20:803–810. © 2004 Wiley‐Liss, Inc.
Glomerular filtration rate: Assessment with dynamic contrast‐enhanced MRI and a cortical‐compartment model in the rabbit kidney
Authors: Annet Laurence , Hermoye Laurent , Peeters Frank , Jamar François , Dehoux Jean‐Paul , Van Beers Bernard E. 
Published: October 2004

AbstractPurposeTo describe the use of MRI and a cortical‐compartment model to measure the glomerular filtration rate (GFR), and compare the results with those obtained with the Patlak‐Rutland model.Materials and MethodsDynamic MRI of rabbit kidneys was performed during and after injection of gadoterate dimeglumine. The enhancement curves in the aorta and the kidney were analyzed with the cortical‐compartment and Patlak‐Rutland models to assess the GFR.ResultsA substantial correlation was observed between the GFR measured with MRI using the cortical‐compartment model and the plasma clearance of 51Cr‐EDTA (r = 0.821,P= 0.004). No significant correlation was observed between the 51Cr‐EDTA clearance (r = 0.628,P= 0.052) and the GFR obtained with the Patlak‐Rutland model in regions of interest (ROIs) encompassing the renal cortex and medulla. A Bland and Altman analysis showed that GFRcorticalcompartmentagreed better with the 51Cr‐EDTA clearance compared to GFRPatlakwhen ROIs were limited to the cortex. However, the GFR values obtained by MRI were lower than the plasma clearance of 51Cr‐EDTA.ConclusionMRI with a cortical‐compartment model provides more accurate assessments of glomerular filtration than the Patlak‐Rutland model. J. Magn. Reson. Imaging 2004;20:843–849. © 2004 Wiley‐Liss, Inc.
Discovery and disclosure of incidental findings in neuroimaging research
Authors: Illes Judy , Kirschen Matthew P. , Karetsky Kim , Kelly Megan , Saha Arnold , Desmond John E. , Raffin Thomas A. , Glover Gary H. , Atlas Scott W. 
Published: October 2004

AbstractPurposeTo examine different protocols for handling incidental findings on brain research MRIs, and provide a platform for establishing formal discussions of related ethical and policy issues.Materials and MethodsCorresponding authors identified from a database of peer‐reviewed publications in 1991–2002 involving functional MRI (fMRI), alone or in combination with other imaging modalities, were invited to participate in this web‐based survey. The survey asked questions regarding knowledge and handling of incidental findings, as well as characteristics of the scanning environment, training required, IRB protocol requirements, and neuroradiologist involvement.ResultsSeventy‐four investigators who conduct MRI studies in the United States and abroad responded. Eighty‐two percent (54/66) reported discovering incidental findings in their studies, such as arteriovenous malformations, brain tumors, and developmental abnormalities. Substantial variability was found in the procedures for handling and communicating findings to subjects, neuroradiologist involvement, personnel permitted to operate equipment, and training.ConclusionGuidelines for minimum and optimum standards for detecting and communicating incidental findings on brain MRI research are needed. J. Magn. Reson. Imaging 2004;20:743–747. © 2004 Wiley‐Liss, Inc.
Comparative study of methods for determining vascular permeability and blood volume in human gliomas
Authors: Harrer Judith U. , Parker Geoff J.M. , Haroon Hamied A. , Buckley David L. , Embelton Karl , Roberts Caleb , Balériaux Danielle , Jackson Alan 
Published: October 2004

AbstractPurposeTo characterize human gliomas using T1‐weighted dynamic contrast‐enhanced MRI (DCE‐MRI), and directly compare three pharmacokinetic analysis techniques: a conventional established technique and two novel techniques that aim to reduce erroneous overestimation of the volume transfer constant between plasma and the extravascular extracellular space (EES) (Ktrans) in areas of high blood volume.Materials and MethodsEighteen patients with high‐grade gliomas underwent DCE‐MRI. Three kinetic models were applied to estimate Ktrans and fractional blood plasma volume (vp). We applied the Tofts and Kermode (TK) model without arterial input function (AIF) estimation, the TK model modified to include vp and AIF estimation (mTK), and a “first pass” variant of the TK model (FP).ResultsKTK values were considerably higher than KmTK and KFP values (P < 0.001). KmTK and KFP were more comparable and closely correlated (ρ = 0.744), with KmTK generally higher than KFP (P < 0.001). Estimates of vp(mTK) and vp(FP) also showed a significant difference (P < 0.001); however, these values were very closely correlated (ρ = 0.901). KTK parameter maps showed “pseudopermeability” effects displaying numerous vessels. These were not visualized on KmTK and KFP maps but appeared on the corresponding vp maps, indicating a failure of the TK model in commonly occurring vascular regions.ConclusionBoth of the methods that incorporate a measured AIF and an estimate of vp provide similar pathophysiological information and avoid erroneous overestimation of Ktrans in areas of significant vessel density, and thus allow a more accurate estimation of endothelial permeability. J. Magn. Reson. Imaging 2004;20:748–757. © 2004 Wiley‐Liss, Inc.