bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cyclopropene: A New Simple Synthesis and itsDiels‐Alder Reaction With Cyclopentadiene
Authors: Binger Paul , Wedemann Petra , Brinker Udo H. 
Published: November 2003

AbstractCyclopropene: A new simple synthesis and its Diels‐Alder reaction with cyclopentadieneintermediate: Cyclopropeneproduct: endo‐tricyclo[3.2.1.02,4]oct‐6‐ene
The ultrastructure of the capillaries in the gingiva of alloxan‐induced diabetic rats
Authors: Gül Nursel , Özsoy Nesrin 
Published: November 2003

AbstractThe diabetic effects of alloxan (type I diabetes mellitus) were investigated in 40 Wistar albino rats (18 controls and 22 diabetics). Alloxan in sterile physiological saline was injected into animals intravenously. After the induction of diabetes with alloxan, the ultrastructure of the capillaries in the gingiva was examined by transmission electron microscopy. The thickness of the basement membranes was observed closely adherent to the endothelial cells of the capillary alloxan‐diabetic rats. It was greatly thickened owing to the increase in its amorphous, granular and filamentous material with occasional scattered collagen fibres. In some sections, the capillary lumens of the diabetics were closed by epithelial cells. Loss of cytoplasmic material and hyalinization were seen in some smooth muscle cells. In addition, the mitochondrial cristae of smooth muscle cell and epithelial cells disappeared. There was endothelial integrity throughout the smooth muscle cells. Copyright © 2003 John Wiley & Sons, Ltd.
Constitutive secretion of MMP9 by early‐passage cultured human endothelial cells
Authors: Arkell Jacky , Jackson Christopher J. 
Published: November 2003

AbstractMatrix metalloproteinase‐9 (MMP9) plays an important role during angiogenesis. It is an inducible enzyme which is known to be secreted from human endothelial cells in response to phorbol myristate acetate (PMA), but thought not to be constitutively expressed. We examined the secretion of MMP9 by primary culture (P0), passage 1 (P1) and passage 2 (P2) human umbilical vein endothelial cells (HUVE). Whereas there was no detectable MMP9 in P2 cells under basal conditions, P0 HUVE secreted MMP9, as detected by zymography and ELISA. RT‐PCR and cycloheximide inhibition studies confirmed that MMP was synthesized by P0 HUVE. MMP9 secretion was passage‐dependent, decreasing rapidly as the cells were passaged in culture and was not detected at P2. The decrease was largely due to the population doubling of cells as they are cultured. This is the first report to show that cultured HUVE constitutively express MMP9 and that this secretion is restricted to very early‐passage cells. These findings may be relevant to the angiogenic potential of human endothelial cells as they age. Copyright © 2003 John Wiley & Sons, Ltd.
Transcatheter closure of patent foramen ovale associated with paradoxical embolism using the amplatzer PFO occluder: Initial and intermediate‐term results of the U.S. multicenter clinical trial
Authors: Hong Thomas E. , Thaler David , Brorson James , Heitschmidt Mary , Hijazi Ziyad M. 
Published: November 2003

AbstractClosure of patent foramen ovale (PFO) has been proposed as an alternative to anticoagulation in patients with presumed paradoxical emboli. We report the immediate and mid‐term results of the phase 1 U.S. Multicenter Clinical Trial of patients who underwent transcatheter PFO closure for paradoxical embolism using the new Amplatzer PFO device. Fifty patients (28 male/22 female) underwent catheter closure of their PFOs at a mean age of 41 ± 11 years. Thirty‐six patients had ischemic stroke, 10 had transient ischemic attack, and 4 had peripheral embolism. Seventeen patients had atrial septal aneurysm. The implantation procedure was successful in 49/49 patients; one patient did not have a PFO. Complete closure was seen immediately after the procedure in 26/49 patients; 17 had minimal residual shunt, 4 had moderate and 2 had large residual shunts. The median fluoroscopy time was 10.5 min (2.8–43 min). There were no complications related to the device. One patient developed an arteriovenous fistula at the catheter site requiring surgical repair. At a mean follow‐up interval of 16.5 ± 7.2 months, there were no deaths or recurrent neurological or peripheral embolic events. Eight patients reported an episode of dizziness or palpitations (four of them within 18 days of the procedure). No episodes of atrial dysrhythmias were noted. Contrast bubble study at last follow‐up documented complete closure in 45/48 patients; one patient had minimal, one had moderate residual shunt, and one had a large shunt. One patient was lost to follow‐up. We conclude that catheter closure of PFO associated with stroke/transient ischemic attack or peripheral embolism using the new Amplatzer PFO device is a safe and effective method in preventing recurrence of such episodes. Randomized clinical trials comparing device closure versus continued medical therapy are underway. Catheter Cardiovasc Interv 2003;60:524–528. © 2003 Wiley‐Liss, Inc.
Intracoronary electrocardiogram and angina pectoris during percutaneous coronary interventions as an assessment of myocardial viability: Comparison with low‐dose dobutamine echocardiography
Authors: Abaci Adnan , Oguzhan Abdurrahman , Topsakal Ramazan , Seyfeli Ergun , Yilmaz Yucel , Eryol Namık Kemal , Basar Emrullah , Ergin Ali 
Published: November 2003

AbstractThe aims of this study were to evaluate the diagnostic value of intracoronary electrocardiogram (ECG) and presence of angina pectoris during percutaneous coronary interventions in the prediction of myocardial viability assessed by low‐dose dobutamine echocardiography (LDDE). Seventy‐one patients (60 men; mean age, 54 ± 11 years) with recent Q‐wave MI and angiographically documented regional wall motion abnormality in the presence of a significant (≥ 70%) nonocclusive stenosis of the infarct‐related vessel who were referred for angioplasty were prospectively included in the study. The intracoronary ECG was recorded using coronary angioplasty guidewire. Significant ST segment elevation was defined as a new or worsening ST segment elevation of ≥ 0.1 mV at 80 msec after the J‐point. Angina pectoris was noted as present or absent during balloon inflation. All patients underwent LDDE for viability assessment. Significant ST segment elevation in the intracoronary ECG and chest pain were observed in 56 (78.9%) and 49 (69%) of the 71 patients. Viability was present on LDDE in 52 (92.9%) of 56 patients with and 3 (20%) of 15 without ST segment elevation. Viability was detected in 45 (91.8%) of 49 patients with and 10 (45.4%) of 22 without angina pectoris during balloon occlusion. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of ST segment elevation for viability were 94.5%, 75%, 92.9%, 80%, and 90.1%, respectively. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of angina pectoris for viability were 81.8%, 75%, 91.8%, 54.5%, and 80.3%, respectively. The present study demonstrated that a simple assessment of ST segment elevation in the intracoronary ECG or angina pectoris during coronary angioplasty can be used to assess myocardial viability identified by LDDE in patients with previous MI. Catheter Cardiovasc Interv 2003;60:469–476. © 2003 Wiley‐Liss, Inc.
The porcine coronary model of in‐stent restenosis: Current status in the era of drug‐eluting stents
Authors: Lowe Harry C. , Schwartz Robert S. , Mac Neill Briain D. , Jang Ik‐Kyung , Hayase Motoya , Rogers Campbell , Oesterle Stephen N. 
Published: November 2003

AbstractDrug‐eluting stents are revolutionizing interventional cardiology. Sirolimus‐eluting stents are in widespread clinical use, associated with well‐documented remarkably low restenosis rates, and a number of other agents appear promising in clinical trials. These human studies have been preceded by numerous animal studies, foremost among them the pig coronary model of in‐stent restenosis (ISR). The histologic response to porcine coronary stenting was described over a decade ago. Porcine stenting studies now provide examinations not only of histology, but also mechanisms of action, toxicity, and biocompatibility. This review therefore examines the current status of this porcine coronary model of ISR. Contemporary methods of pig coronary stenting are discussed. The morphometric, cellular, and molecular analyses of the responses to stent injury are then described. Finally, recent pig coronary drug‐eluting stent studies are examined, with a discussion of their advantages, limitations, and possible future modifications. Catheter Cardiovasc Interv 2003;60:515–523. © 2003 Wiley‐Liss, Inc.
Ipsilateral representation of oral structures in human anterior parietal somatosensory cortex and integration of inputs across the midline
Authors: Disbrow Elizabeth A. , Hinkley Leighton B.N. , Roberts Timothy P.L. 
Published: November 2003

AbstractAnterior parietal somatosensory areas 3a, 3b, 1, and 2 generally contain cells with receptive fields that are on the contralateral body. However, inputs from midline structures such as the mouth must be uniquely integrated across the midline. This hypothesis is supported by studies of these fields from nonhuman primates that demonstrate ipsilateral representations of oral structures. We used magnetoencephalography (MEG) to examine the cortical representations of the lips and tongue in humans and to examine the time course of interaction of bilateral inputs from these structures. Ipsilateral activation was observed in response to tactile stimulation of the upper lip in 69% of cases, the lower lip in 85% of cases, and the tongue in 88% of cases. In the contralateral hemisphere, the map of oral structures tended to be in agreement with that from nonhuman primates, although variation was large and source locations were not statistically significantly different from each other. There were no differences in latency of activation for ipsi‐vs. contralateral responses (about 30 msec), and cortical sources from ipsi‐and contralateral stimulation tended to be located together. Differential activation for bilateral vs. unilateral stimulation occurred later than activation in S1, around 110 msec, and was localized to the upper bank of the Sylvian sulcus. Our findings indicate that, unlike nonhuman primates, humans have an ipsilateral representation of the lips in 3b/1, possibly related to the precise manipulation necessary for the articulation of speech. The distinct pattern of differential activation for uni‐vs. bilateral stimulation suggests a unique neural mechanism of integration across the midline for inputs from the mouth. J. Comp. Neurol. 467:487–495, 2003. © 2003 Wiley‐Liss, Inc.
mRNA expression patterns of the cGMP‐hydrolyzing phosphodiesterases types 2, 5, and 9 during development of the rat brain
Authors: Van Staveren Wilma C.G. , Steinbusch Harry W.M. , Markerink‐Van Ittersum Marjanne , Repaske David R. , Goy Michael F. , Kotera Jun , Omori Kenji , Beavo Joseph A. , De Vente Jan 
Published: November 2003

AbstractRecent evidence indicates that cGMP plays an important role in neural development and neurotransmission. Since cGMP levels depend critically on the activities of phosphodiesterase (PDE) enzymes, mRNA expression patterns were examined for several key cGMP‐hydrolyzing PDEs (type 2 [PDE2], 5 [PDE5], and 9 [PDE9]) in rat brain at defined developmental stages. Riboprobes were used for nonradioactive in situ hybridization on sections derived from embryonic animals at 15 days gestation (E15) and several postnatal stages (P0, P5, P10, P21) until adulthood (3 months). At all stages PDE9 mRNA was present throughout the whole central nervous system, with highest levels observed in cerebellar Purkinje cells, whereas PDE2 and PDE5 mRNA expression was more restricted. Like PDE9, PDE5 mRNA was abundant in cerebellar Purkinje cells, although it was observed only on and after postnatal day 10 in these cells. In other brain regions, PDE5 mRNA expression was minimal, detected in olfactory bulb, cortical layers, and in hippocampus. PDE2 mRNA was distributed more widely, with highest levels in medial habenula, and abundant expression in olfactory bulb, olfactory tubercle, cortex, amygdala, striatum, and hippocampus. Double immunostaining of PDE2, PDE5, or PDE9 mRNAs with the neuronal marker NeuN and the glial cell marker glial fibrillary acidic protein revealed that these mRNAs were predominantly expressed in neuronal cell bodies. Our data indicate that three cGMP‐hydrolyzing PDE families have distinct expression patterns, although specific cell types coexpress mRNAs for all three enzymes. Thus, it appears that differential expression of PDE isoforms may provide a mechanism to match cGMP hydrolysis to the functional demands of individual brain regions. J. Comp. Neurol. 467:566–580, 2003. © 2003 Wiley‐Liss, Inc.
Cumulant‐based approach to FIR system identification
Authors: Al‐Smadi Adnan 
Published: November 2003

AbstractIn this paper, a non‐recursive approach is developed for estimating the coefficients of a moving average (MA) model from only third‐order cumulant statistics of a finite realization of the observations of the output data. The signal observations may be noisy. The excitation signal is assumed to be zero mean, non‐Gaussian stationary sequence that is not observed. The noise is additive and may be coloured Gaussian or non‐Gaussian. This novel technique is based on forming a third‐order cumulant composite data matrix. The method presented here requires the solution of a system of linear equations, which can be achieved using least‐squares methods. The proposed approach is illustrated via computer simulations and is shown to be consistent. Copyright © 2003 John Wiley & Sons, Ltd.
Effect of carbohydrates attached to polystyrene on hepatocyte morphology on sugar‐derivatized polystyrene matrices
Authors: Kim Sang‐Heon , Hoshiba Takashi , Akaike Toshihiro 
Published: November 2003

AbstractSugar‐carrying polymers have been utilized as artificial matrices for cell adhesion in tissue engineering. We have developed sugar‐derivatized polystyrenes (PV‐sugars) as artificial matrices, which control hepatocyte adhesion and hepatic function. Hepatocytes adhere to PV‐sugar matrices in a receptor‐mediated manner. In this study, we designed a new galactose‐derivatized PV‐sugar, poly‐(6‐O‐p‐vinylbenzyl‐α‐D‐galactose) (PV6Gal) and evaluated the role of carbohydrate attached to polystyrene (PS) backbone in the morphological difference of hepatocyte cultured on PV–sugar matrices. Hepatocytes spread on monosaccharide‐derivatized PV‐sugars but not on disaccharide‐derivatized PV‐sugars. The actin filament remained aggregated in the central area of the cell body on disaccharide‐derivatized PV‐sugars. Hepatocyte cell bodies fully were spread on collagen, and the actin filament was almost completely reorganized. Hepatocyte spreading on monosaccharide‐derivatized PV‐sugars, however, was caused by protrusive cell–matrix contact like lamellipodia and the actin filament was not completely reorganized. This indicated that hepatocyte spreading on PV‐sugar matrices was restricted compared with ECM‐mediated cell spreading. In addition, typical spheroid formation of hepatocytes was promoted on disaccharide‐derivatized PV‐sugars compared with monosaccharide‐derivatized PV‐sugars. Although hepatocytes adhered with different affinities to PV‐sugar matrices, hepatocyte morphology was not affected by the adhesion affinity. We suggest that the type of carbohydrate attached to the PS backbone governs the morphology of hepatocyte cultured on PV‐sugar matrices. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 67A: 1351–1359, 2003
Impact on the thrombogenicity of surface oxide properties of 316l stainless steel for biomedical applications
Authors: Shih Chun‐Che , Shih Chun‐Ming , Su Yea‐Yang , Lin Shing‐Jong 
Published: November 2003

AbstractSurface oxide film on cardiovascular devices could be one of the most critical factors that determine the degree of thrombosis. Previous studies have shown that metallic wire passivated with amorphous oxide film provides excellent corrosion and scratch resistance. Investigation was undertaken to see whether this oxide film, with its unique electrochemical properties, could reduce the development of thrombosis. Results show that amorphous oxide has higher value of time constant, lower open‐circuit potential, and lower degree of thrombosis. These distinguished characteristics prove amorphous oxide to be the best candidate for the cardiovascular devices. Amorphous oxide film could be a potential solution to the thrombogenic problem of cardiovascular devices. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 67A: 1320–1328, 2003
Bioactive PMMA bone cement prepared by modification with methacryloxypropyltrimethoxysilane and calcium chloride
Authors: Miyazaki Toshiki , Ohtsuki Chikara , Kyomoto Masayuki , Tanihara Masao , Mori Akiko , Kuramoto Kou‐ichi 
Published: November 2003

AbstractBone cement consisting of polymethylmethacrylate (PMMA) powder and methylmethacrylate (MMA) liquid is used extensively for fixation of implants such as artificial hip joints with living bone. This type of cement, however, does not show direct bonding to the living body, and hence the fixation is liable to loosen over a long implantation period. Bioactive materials have received much attention because of their capability for bone‐bonding, i.e., bioactivity, when implanted in bony defects. Osteoconduction of the bioactive materials is caused by formation of a bone‐like apatite layer through a surface reaction between the material and surrounding body fluid. The apatite formation can be induced by a silanol (SiOH) group formed on the materials as well as a dissolution of calcium ion (Ca2+) from the material. Incorporation of alkoxysilane and calcium chloride (CaCl2) may provide PMMA bone cement with bioactivity, because alkoxysilane gives SiOH after hydrolysis, whereas CaCl2 releases Ca2+. In this study, we investigated the potential on bioactivity of the modified PMMA bone cement with alkoxysilane and calcium chloride. PMMA powder was mixed with various amounts of CaCl2, and MMA liquid with various amounts of 3‐methacryloxypropyltrimethoxysilane (MPS). The mixed paste was immersed in a simulated body fluid (Kokubo solution) that has a similar concentration in inorganic constituents to human blood plasma. After soaking for various periods, apatite formation on the cement was examined. Apatite formation was observed by the addition of CaCl2 with contents of 16 mass % and more. Incorporation of MPS accelerates the apatite formation. Setting time of the cement was significantly elongated after the addition of MPS, whereas compressive strength significantly decreased with increasing the contents of CaCl2 and MPS. The hardened cement containing 20 mass % of CaCl2 in the powder and 20 mass % of MPS in the liquid showed a tendency to be more osteoconductive to living bone after implantation in rabbit tibiae than the unmodified cement. These results indicate that bioactivity of the modified PMMA bone cement increases with increasing amounts of MPS and CaCl2. Bioactive bone cement is successfully obtained when it contains appropriate concentrations of alkoxysilane and calcium chloride. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 67A: 1417–1423, 2003
Differential expression of isoproterenol‐induced salivary polypeptides in two mouse strains that are congenic for the H‐2 histocompatibility gene complex
Authors: López Solís Remigio O. , Weis Ulrike Kemmerling , Ceballos Alicia Ramos , Salas Gustavo Hoecker 
Published: November 2003

AbstractTwo inbred mouse strains, A/Snell and A.Swiss, which were produced as congenic with regard to the H‐2 histocompatibility gene complex, are homozygous for two different groups of isoproterenol‐induced salivary polypeptides (IISP). These polypeptides, which have been considered as markers of the hypertrophic growth of the parotid acinar cells, are members of the complex family of salivary proline‐rich proteins (PRP) on the basis of both their massive accumulation in the parotid acinar cells in response to chronic isoproterenol, secretory character, high solubility in trichloroacetic acid and metachromatic staining by Coomassie blue. IISP expressed in both mouse strains were identified by unidimensional SDS–polyacrylamide electrophoresis and Coomassie blue staining both in parotid gland homogenates and in whole salivas obtained from mice repeatedly stimulated at 24‐h intervals with isoproterenol. Parotid glands from 40 mice (20 A/Snell and 20 A.Swiss) and salivas from 270 mice (200 A/Snell and 70 A.Swiss) were analyzed. One of the congenic strains (A/Snell) expressed five IISP (Mr 65, 61, 51.5, 38, and 37 kDa) and the other strain (A.Swiss) expressed six IISP (Mr 59, 57, 54.5, 46, 36, and 34 kDa). No inter‐individual intra‐strain variations were observed, thus defining strain‐associated patterns of IISP (PRP). © 2003 Wiley‐Liss, Inc.
Effect of growth and maturation on membrane‐initiated actions of 1,25‐dihydroxyvitamin D3—II: Calcium transport, receptor kinetics, and signal transduction in intestine of female chickens
Authors: Larsson Birgitta , Nemere Ilka 
Published: November 2003

AbstractWe recently reported (Larsson and Nemere [2003]: Endocrinology 144:1726) the effects of growth and maturation on 1,25(OH)2D3‐membrane initiated effects in the intestine of male chickens. Here we extend our observations to studies on females with two stages of high calcium demand: growth (7–14 weeks) and egg laying (28–58 weeks). The rapid stimulatory effect of 130 pM 1,25(OH)2D3 on calcium transport was assessed as a physiological response in perfused duodena of 7‐, 14‐, 28‐, and 58‐week‐old chickens, and determined to be 308%, 184%, 170%, and 153%, respectively, of corresponding controls after 40 min. Saturation analyses of [3H]1,25(OH)2D3 binding to nuclear vitamin D receptor (VDR) indicated an absence of cooperative binding, no changes in dissociation constant (Kd) with age, and an increase in maximum binding capacity (Bmax) between 7‐week birds and older age groups. Analyses of saturable binding of [3H]1,25(OH)2D3 to the membrane associated rapid response steroid binding protein (1,25D3‐MARRS bp) in basal lateral membranes (BLM), indicated cooperative binding, and an increase in both Bmax and Kd with age. No changes in the age‐related expression of 1,25D3‐MARRS bp were found, as judged by Western analyses, suggesting that a shift in ligand binding to lower affinity membrane components accounted for the increase in calculated Bmax. Basal levels of protein kinase C (PKC) activity decreased with age, as did hormone enhancement of activity. Basal levels of protein kinase A (PKA) activity remained constant with age, while the magnitude of hormone stimulation increased. Comparison of dose‐response curves for ion transport and kinase activities in 7‐week chicks suggested that PKC mediates phosphate transport while PKA mediates calcium transport. Thus, the age‐related loss of calcium transport is most likely related to loss of PKC‐mediated phosphate transport. © 2003 Wiley‐Liss, Inc.