bluuebunny/crossref_metadata_2025 huggingface dataset:
Variation in sulfation pattern of galactosaminoglycan containing proteoglycans is associated with the development of uterine leiomyoma
Authors: Mitropoulou Theony N. , Stagiannis Konstantinos D.
Published: March 2004

The variations in sulfation patterns of glycosaminoglycans (GAGs) present in human normal myometrium and uterine leiomyoma were characterized following speciﬁc enzymic treatments and analysis by high‐performance capillary electrophoresis (HPCE). Differences in the disaccharide composition of galactosaminoglycans (GalAGs) between normal myometrium and uterine leiomyoma were found. The results of this study suggest that the development of uterine leiomyoma is closely related not only to quantitative changes in the amount of GAGs but also in the sulfation of GalAGs. These differences may be attributed to increased synthesis of ﬁbrotic connective tissue and deposition of collagen. Copyright © 2004 John Wiley & Sons, Ltd.
Transradial application of percusurge guardwire device during primary percutaneous intervention of infarct‐related artery with high‐burden thrombus formation
Authors: Yip Hon‐Kan , Chen Mien‐Cheng , Chang Hsueh‐Wen , Kuo Fan‐Ying , Yang Cheng‐Hsu , Chen Shyh‐Ming , Hung Wei‐Chin , Chen Chien‐Jen , Cheng Cheng‐I , Wu Chiung‐Jen
Published: March 2004

A large infarct‐related artery (IRA), which mostly contains high‐burden thrombus formation (HBTF) and lipid pool‐like plaque contents, has been suggested to play a pivotal role in the no‐reflow phenomenon during primary percutaneous coronary intervention (p‐PCI). To reduce the thrombus burden of the IRA using the PercuSurge GuardWire device before intervention may be of crucial importance to preventing no‐reflow. The purposes of this study were to test the transradial application (TRA) of this new mechanical device and to determine its impact on prevention of no‐reflow during p‐PCI. From May to September 2002, the PercuSurge GuardWire device was utilized in 42 consecutive patients with acute myocardial infarction and large IRA (vessel size ≥ 3.5 mm with HBTF; group 1). From January to December 2000, p‐PCI was performed in large IRA (vessel size ≥ 3.5 mm) with HBTF using tranfemoral arterial approach in 101 consecutive patients (group 2). The angiographic and clinical outcomes of the two groups were compared in a chronologically consecutive manner. Successful reperfusion (final TIMI‐3 flow) was significantly higher in group 1 than in group 2 patients (95.2% vs. 79.1%; P = 0.005). Moreover, the combined incidence of vascular complications, post‐PCI thromboembolisms (defined as a distal embolism and a post‐PCI residual thrombus score of ≥ 3), and combined 30‐day major adverse cardiac events were significantly lower in group 1 than in group 2 patients (all P values < 0.05). In group 1 patients, post‐p‐PCI myocardial blush (MB) of ≥ 2 grades was found to be more than 88.0%. Furthermore, when compared with preintervention, thrombus scores were significantly reduced after aspiration (P = 0.0001), whereas the minimal lumen diameter (P = 0.0001), TIMI flow grade (P = 0.0001), and MB grade (P = 0.0001) had all significantly increased after aspiration using Export Aspiration Catheter. There were no significant differences in corrected TIMI frame count (P = 0.42), TIMI flow grade (P > 0.5), or MB grade (all P values > 0.5) between postaspiration and post‐PCI. The TRA of the PercuSurge GuardWire device during primary intervention of large IRA with HBTF was safe and feasible and provided benefits to patients. The initial successful reduction of the thrombus burden with this mechanical device before intervention can be translated into increased final TIMI‐3 flow, a combined MB of ≥ 2 grades, and fewer final thromboembolic events. Catheter Cardiovasc Interv 2004;61:503–511. © 2004 Wiley‐Liss, Inc.
Feasibility of simultaneous bilateral carotid artery stenting
Authors: Chen Michael S. , Bhatt Deepak L. , Mukherjee Debabrata , Chan Albert W. , Roffi Marco , Kapadia Samir R. , Ziada Khaled M. , Chew Derek P. , Bajzer Christopher T. , Yadav Jay S.
Published: March 2004

Due to the progressive aging of the population, severe bilateral carotid stenosis has become a more frequent condition. On occasion, simultaneous revascularization may be appropriate. There is increased evidence that for these high‐risk patients, a percutaneous revascularization may be the best approach. However, there are concerns that simultaneous bilateral carotid stenting may be associated with cerebral hyperperfusion, excessive bradycardia, and hypotension. We report a series of 10 consecutive patients who underwent simultaneous bilateral carotid stenting. All of these patients were not deemed to be surgical candidates due to high‐risk comorbidities. All but one of the lesions were successfully stented. There were no procedural deaths, myocardial infarctions, or strokes. Thus, among carefully selected patients, simultaneous bilateral carotid artery stenting is a promising, technically feasible option. Catheter Cardiovasc Interv 2004;61:437–442. © 2004 Wiley‐Liss, Inc.
Effects of gamma radiation on the noninjured and unprotected left main
Authors: Wolfram Roswitha , Cheneau Edouard , Lew Robert , Chan Rosanna , Pichard Augusto D. , Satler Lowell F. , Kent Kenneth M. , Dilcher Christian , Pinnow Ellen , Bui Anh , Waksman Ron
Published: March 2004

The aim of this study was to evaluate the effect of gamma radiation on the noninjured, unprotected left main coronary artery. Noninjured vessel segments are often radiated during treatment of in‐stent restenosis with PCI and gamma radiation. Angiographic analysis using QCA methods was performed on 55 left main arteries of patients (32 with radiation of the left main compared to 23 controls) who participated in the Washington Radiation for In‐Stent Restenosis Trials (WRIST). Baseline demographics and follow‐up were comparable between the two groups, concluding that gamma radiation with long radiation safety margins is feasible and safe. Gamma radiation of noninjured irradiated left main vessels when used to facilitate wide radiation margins for proximal irradiated injured LAD and LCx is safe and does not compromise the vessel integrity and its lumen. Catheter Cardiovasc Interv 2004;61:477–481. © 2004 Wiley‐Liss, Inc.
Acute aortic insufficiency complicating stent treatment of supravalvular aortic stenosis: Successful release of trapped leaflets by wiring the stent
Authors: Suárez de Lezo José , Pan Manuel , Medina Alfonso , Segura José , Pavlovic Djordje , Romero Miguel
Published: March 2004

This report shows the findings observed in a 7‐year‐old boy patient having severe supravalvular aortic stenosis who was treated by stent implantation. Immediately after deployment, a severe acute aortic insufficiency developed due to leaflets trapped by the stent. Release was attempted percutaneously. After wiring the proximal stent, snaring the wire and pulling smoothly, the leaflets came free and valve competence was completely restored. The procedure was then successfully completed, with no residual gradient or aortic insufficiency. Catheter Cardiovasc Interv 2004;61:537–541. © 2004 Wiley‐Liss, Inc.
Novel use of the Amplatzer duct occluder to close perivalvar leak involving a prosthetic mitral valve
Authors: Kort Henry W. , Sharkey Angela M. , Balzer David T.
Published: March 2004

Perivalvar leak following atrioventricular valve replacement can result in heart failure or hemolytic anemia. These patients may be poor surgical candidates given a complex clinical condition. We describe transcatheter closure of a perivalvar leak in a 3‐month infant who had undergone left atrioventricular valve replacement with a St. Jude's prosthesis. Catheter Cardiovasc Interv 2004;61:548–551. © 2004 Wiley‐Liss, Inc.
Clinical and angiographic outcomes after overdilatation of undersized sirolimus‐eluting stents with largely oversized balloons: An observational study
Authors: Saia Francesco , Lemos Pedro A. , Arampatzis Chourmouzios A. , Hoye Angela , McFadden Eugene , Sianos Georgios , Smits Pieter C. , van der Giessen Willem J. , de Feyter Pim J. , van Domburg Ron T. , Serruys Patrick W.
Published: March 2004

The purpose of this study was to assess the safety and effectiveness of sirolimus‐eluting stent (SES) postdilatation with largely oversized balloons. We evaluated the clinical outcome of 68 consecutive patients enrolled in the Rapamycin‐Eluting Stent Evaluated at Rotterdam Cardiology Hospital (RESEARCH) registry who underwent percutaneous coronary intervention with SES implantation and further postdilatation with balloons > 1 mm larger than the stent nominal size. Angiographic follow‐up was either scheduled for selected subgroups or clinically driven. Overall, 75 lesions were treated. The procedure was successful in 98.5% of the cases. One patient (1.5%) underwent emergency coronary bypass surgery for acute vessel occlusion. During 10.1 ± 1.7 months of follow‐up, three patients (4.5%) died, one (1.5%) had acute myocardial infarction, and four (6%) had target vessel revascularization. At angiographic follow‐up, loss index was 0.13 ± 0.34 and restenosis rate was 7.7%. Although not routinely recommended in every patient, SES postdilatation with largely oversized balloons appears a safe and effective strategy for selected patients. Catheter Cardiovasc Interv 2004;61:455–460. © 2004 Wiley‐Liss, Inc.
Renal artery compromise treated percutaneously in a patient with chronic aortic dissection: A case report
Authors: Awadalla Hany M. , Salloum Joseph G. , Smalling Richard W.
Published: March 2004

Organ malperfusion most commonly occurs in the acute stage of aortic dissection and is associated with a high mortality, but can occur with chronic dissection. We describe a case of a type 3 aortic dissection, which had a stenosed left renal artery originating from the false lumen and causing resistant hypertension. The left renal artery was successfully dilated and stented, with prompt resolution of the patient's hypertension. Catheter Cardiovasc Interv 2004;61:445–449. © 2004 Wiley‐Liss, Inc.
Coronary rotational atherectomy in current practice: Acute and mid‐term results in high‐ and low‐volume centers
Authors: Rubartelli Paolo , Niccoli Luigi , Alberti Alessandro , Giachero Corinna , Ettori Federica , Missiroli Bindo , Bernardi Guglielmo , Maiello Luigi , Reimers Bernhard , Cernigliaro Carmelo , Sardella Gennaro , Bramucci Ezio
Published: March 2004

We conducted a prospective observational study to evaluate the indications, technique, in‐hospital and 9‐month results of consecutive patients treated with rotational atherectomy (RA) in 12 centers during 1 year, as well as their relationship with volume of RA activity. The study included 345 lesions in 289 patients treated (4.4% ± 2.6% of procedures at the participating centers). The lesions were mostly calcified (63%) and type B2 or C (74%). Procedural success was obtained in 94% of patients, with a major adverse cardiac event (MACE) rate of 4.5%. At 9 months, MACE occurred in 17.3%. Multivariate analysis identified multivessel disease and slow flow as negative predictors of procedural success, whereas balloon pressure ≤ 6 atm and hypercholesterolemia were associated with decreased MACE at 9 months. Center RA volume was not associated with in‐hospital or 9‐month outcome. We conclude that RA, even when used sporadically in selected complex lesions, can provide good immediate and mid‐term results. Catheter Cardiovasc Interv 2004;61:463–471. © 2004 Wiley‐Liss, Inc.
Advanced c‐myc antisense (AVI‐4126)‐eluting phosphorylcholine‐coated stent implantation is associated with complete vascular healing and reduced neointimal formation in the porcine coronary restenosis model
Authors: Kipshidze Nicholas N. , Iversen Patrick , Kim Han‐Soo , Yiazdi Hamid , Dangas George , Seaborn Rufus , New Gishel , Tio Fermin , Waksman Ron , Mehran Roxana , Tsapenko Mykola , Stone Gregg W. , Roubin Gary S. , Iyer Sriram , Leon Martin B. , Moses Jeffrey W.
Published: March 2004

An advanced six‐ring morpholino backbone c‐myc antisense (AVI‐4126) was shown to inhibit c‐myc expression and intimal hyperplasia after local catheter delivery in a porcine balloon injury model. The purpose of this study was to investigate the effects of an AVI‐4126‐eluting phosphorylcholine‐coated (PC) stent on c‐myc expression restenosis and vascular healing after stent implantation in porcine coronary arteries. PC stents were loaded with AVI‐4126 using soak trap. Nine pigs underwent AVI‐4126 PC coronary stent implantation (two stents/animal). Two to six hours postprocedure, three pigs were sacrificed and stented segments were analyzed by Western blot for c‐myc expression. In chronic experiments, six pigs (12 stent sites) were sacrificed at 28 days following intervention and vessels were perfusion‐fixed. High‐performance liquid chromatography analysis of plasma samples showed minimal presence of the antisense. Western blot analysis of the stented vessels demonstrated inhibition of c‐myc expression at 2 and 6 hr after procedure. Quantitative histologic morphometry showed that the neointimal area was significantly reduced (by 40%) in the antisense‐coated group compared with control (2.3 ± 0.7 vs. 3.9 ± 0.8 mm2, respectively; P = 0.0077). Immunostaining and electron microscopy demonstrated complete endothelialization, without fibrin deposition, thrombosis, or necrosis in all implanted stents. In the porcine coronary model, an advanced c‐myc‐eluting PC stent blocked c‐myc expression and significantly inhibited myointimal hyperplasia and allowed complete reendothelialization and healing response. Catheter Cardiovasc Interv 2004;61:518–527. © 2004 Wiley‐Liss, Inc.
Transradial approach for percutaneous transluminal angioplasty and stenting in the treatment of chronic mesenteric ischemia
Authors: Raghu Cherukupalli , Louvard Yves
Published: March 2004

Chronic mesenteric ischemia (CMI) occurs in the presence of slowly progressive, long‐standing stenoses of the visceral arteries secondary to atherosclerosis. Angioplasty and stenting are emerging as therapeutic alternatives to surgery in treating CMI. The transradial approach is an attractive alternative access for performing stenting in CMI at improved safety and ease. A case of CMI treated with stenting of the visceral arteries by both transradial and femoral approaches is presented here. The main difficulty in accessing the celiac and mesenteric arteries through the femoral approach is the angle between the aorta and these vessels, which often leads the operator to use multiple catheters. The main advantage of the radial approach (as well as the brachial one) is that it allows easy coaxial alignment of the catheter with the artery. The main problem is the inadequate length of the currently available catheters. The radial approach eliminates the risk for vascular complications and permits early ambulation. Catheter Cardiovasc Interv 2004;61:450–454. © 2004 Wiley‐Liss, Inc.
Temporary coronary guidewire pacing during percutaneous coronary intervention
Authors: Mixon Timothy A. , Cross Donald S. , Lawrence Mark E. , Gantt D. Scott , Dehmer Gregory J.
Published: March 2004

Temporary pacing is occasionally required during percutaneous coronary artery interventions. This can be accomplished by the insertion of a temporary transvenous pacemaker wire into the right ventricle, but there is some risk and inconvenience associated with this approach. Temporary pacing using the coronary artery guidewire was described in 1985 but is used infrequently. Using currently available equipment, we evaluated guidewire pacing in 26 patients. Guidewire pacing was successful in all patients, but not with all coronary guidewires at acceptable ventricular capture thresholds. No complications occurred from guidewire pacing. Bench testing of multiple different wires showed several with very high resistances likely unsuitable for clinical use. Temporary guidewire pacing is easily performed and should be considered as an alternative to the separate placement of a temporary transvenous pacemaker. Catheter Cardiovasc Interv 2004;61:494–500. © 2004 Wiley‐Liss, Inc.
Comparison of combination therapy of adenosine and nitroprusside with adenosine alone in the treatment of angiographic no‐reflow phenomenon
Authors: Barcin Cem , Denktas Ali E. , Lennon Ryan J. , Hammes LaVon , Higano Stuart T. , Holmes David R. , Garratt Kirk N. , Lerman Amir
Published: March 2004

We sought to compare the combination therapy of adenosine and nitroprusside in no‐reflow phenomenon during percutaneous coronary intervention. Improvement in coronary flow from no‐reflow to postdrug state was evaluated. Patients who received adenosine (n = 21) were compared to ones who received the combination of adenosine and nitroprusside (n = 20) for treatment. Improvement of TIMI flow grades was higher in the group that received combined therapy (1.5 ± 1.0 vs. 0.8 ± 0.6; P < 0.05). Combination therapy of adenosine and nitroprusside is safe and provides better improvement in coronary flow compared to intracoronary adenosine alone in case of impaired flow during coronary interventions. Catheter Cardiovasc Interv 2004;61:484–491. © 2004 Wiley‐Liss, Inc.
Embolization and retrieval of the Amplatzer septal occluder
Authors: Levi Daniel S. , Moore John W.
Published: March 2004

Embolization and percutaneous retrieval of the Amplatzer septal occluder (ASO) after release have been reported. However, the incidence, the causes of embolization, and the methods for effective retrieval have not been systematically described. In a survey of the ASO company‐designated proctors, the incidence of ASO embolization in this group's experience was 0.55% (21 embolizations in 3,824 device placements) with a wide range of patient demographics, atrial septal defect (ASD) sizes, and device sizes. Most embolizations occurred because of inadequate rim or undersized devices. Of the 21 embolizations, 15 of the devices were retrieved percutaneously with a gooseneck snare without morbidity or mortality. Six were retrieved at surgery. Of the 21 patients, 12 had ASO closure of their ASDs, and 9 had surgical ASD closure. In vitro, all devices could be retrieved with sheathes 2 Fr sizes larger than their recommended delivery sheath. Any device larger than 26 mm could be retrieved with its delivery sheath. The ability to pull the snared button into a sheath was variable and was assisted by pulling the device from above with a bioptome and by using a rigid notched sheath. Because the incidence of ASO embolization is about 1 in 200 in the most experienced hands, all operators should be prepared with the techniques and equipment required for percutaneous ASO retrieval. Catheter Cardiovasc Interv 2004;61:543–547. © 2004 Wiley‐Liss, Inc.
Distal protection of bifurcating vessels: A novel approach
Authors: Gerganski Penko , Meerkin David , Lotan Chaim
Published: March 2004

Distal protection devices protect only a single distal vessel. We describe a novel technique to protect both branches following a thrombus‐containing bifurcation lesion. The combination of an occlusive balloon and an arterial filter system provides an attractive solution to the challenging environment of a lesion at high risk for distal embolization supplying more than a single major branch. Catheter Cardiovasc Interv 2004;61:512–514. © 2004 Wiley‐Liss, Inc.
Myonecrosis following stent placement: Association between impaired TIMI myocardial perfusion grade and MRI visualization of microinfarction
Authors: Choi James W. , Gibson C. Michael , Murphy Sabina A. , Davidson Charles J. , Kim Raymond J. , Ricciardi Mark J.
Published: March 2004

Contrast‐enhanced cardiac MRI (ceMRI) and TIMI myocardial perfusion grade analysis (TMPG) are proven methods for visualization of microinfarction and assessment of microvascular perfusion, respectively. To determine whether microvascular obstruction accounts for procedure‐related myonecrosis, 14 poststent patients, 9 with procedural CK‐MB elevation and 5 controls, underwent ceMRI and TMPG. All had TIMI 3 flow pre‐ and poststent. TMPG was normal in 12/14 pre‐ and 7/14 poststent. Those with poststent decline in TMPG had higher CK‐MB (median, 41.0 vs. 7.4 ng/mL; P = 0.01) and larger infarct mass (median, 3.1 vs. 0.89 g; P = 0.04). More extensive myonecrosis (CK‐MB > 3 × normal; infarct mass > 3 g) was observed more frequently if there was a poststent decline in TMPG (3/3, 100%, vs. 2/11, 18.2%; P = 0.03). These data support the theory that distal embolization and microvascular obstruction are associated with myonecrosis following otherwise successful coronary stent placement and provide further insight into its pathophysiology. Catheter Cardiovasc Interv 2004;61:472–476. © 2004 Wiley‐Liss, Inc.
Suitability of the Propulsion Jet Reactor for a Reaction Kinetics Examination of Heterogeneous Gas‐Catalytic Normal‐Pressure Reactions
Authors: Hesselbarth B. , Adler R.
Published: March 2004

Propulsion jet reactors may be used as differential recycle loop reactors in heterogeneous gas catalysis for reaction kinetics analysis. This reactor features straightforward design resulting in comparatively low manufacturing costs. Because of its advantages, the propulsion jet reactor is suited to kinetic examination under extreme reaction conditions with regard to pressure, temperature, or corrosion. The typical features here are the lower gas densities, which decrease further with increasing reaction temperatures, thus reducing the kinetic energy input through the propulsion jet.
Variational Approach to Diffusion Reaction in Spherical Porous Catalyst
Authors: He J.‐H. , Liu H.‐M.
Published: March 2004

A variational formulation of a chemical problem can be very useful because special solution methods can be used, and it gives a deeper insight into the structure, for example, of diffusion reaction. In this study, a variational theory is established for coupled diffusion and nth‐order reaction in a spherical catalyst pellet. Various variational approaches can be applied to obtain both analytical and numerical solutions.
Modeling Nonsteady‐State Regimes of Dilute Pneumatic Conveying
Authors: Eskin D. , Leonenko Y. , Vinogradov O.
Published: March 2004

The nonsteady‐state gas‐particle flows in pipelines are considered. Chaotically moving particles are described as granular gas characterized by granular temperature. This temperature dissipates because of partially inelastic particle collisions with the wall, with each other and also because of the particle viscous friction with gas. The energy losses on a microscale are translated into the pressure losses on a macroscale. The model developed is validated for both steady‐state and nonsteady‐state regimes by comparing calculated pressure losses with experimental data. A detailed numerical study of the nonsteady‐state flows shows that the pipe wall roughness is a major parameter affecting the pressure drop. Flow regimes for different particle elastic properties, particle sizes, and solids loading are studied.
Liquid/Solid Mass Transfer in Fixed Beds
Authors: Zaki M. , Nirdosh I. , Sedahmed G.H. , Baird M.H.I.
Published: March 2004

The liquid/solid mass transfer behavior of a fixed bed of cylinders was studied using the diffusion‐controlled dissolution of copper in acidified potassium dichromate. Variables studied were solution velocity and cylinder diameter. For a steady flow, the data were correlated for the conditions 25 < Re < 600 and Sc = 990 by the equation Sh = 2.65 Sc0.33 Re0.5. A comparison between the present data and previously obtained data for a fixed bed of Raschig rings has revealed that cylinder packing produces higher rates of mass transfer than Raschig rings.
Dynamics of Capillary Electrochromatography: Experimental Study of Flow and Transport in Particulate Beds
Authors: Chen G. , Pačes M. , Marek M. , Zhang Y. , Seidel‐Morgenstern A. , Tallarek U.
Published: March 2004

The chromatographic performance with respect to the flow behavior and dispersion in fixed beds of nonporous and macroporous particles (having mean intraparticle pore diameters of 41, 105, and 232 nm) has been studied in capillary HPLC and electrochromatography. The existence of substantial electroosmotic intraparticle pore flow (perfusive electroosmosis) in columns packed with the macroporous particles was found to reduce stagnant mobile mass transfer resistance and decrease the global flow inhomogeneity over the column cross‐section, leading to a significant improvement in column efficiency compared to capillary HPLC. The effect of electroosmotic perfusion on axial dispersion was shown to be sensitive to the mobile phase ionic strength and mean intraparticle pore diameter, thus, on an electrical double layer interaction within the particles. Complementary and consistent results were observed for the average electroosmotic flow through packed capillaries. It was found to depend on particle porosity and distinct contributions to the electrical double layer behavior within and between particles. Based on these data an optimum chromatographic performance in view of speed and efficiency can be achieved by straightforward adjustment of the electrolyte concentration and characteristic intraparticle pore size.
The Effect of Solids Inventory and Other Factors on the Axial Solids Holdup Profiles in a Twin‐Riser System
Authors: Yan A.‐J. , Zhu J. (Jing‐Xu) , Remize P.‐J. , Bordas A.
Published: March 2004

The axial profiles of cross‐sectional average solids holdup profiles were studied in two 10 m long, 76 mm i. d. and 203 mm i. d. risers with the solids circulation rate up to 550 kg/m2s, superficial gas velocities up to 10.0 m/s, and solids inventory up to 410 kg in the 320 mm i. d. storage tank. The shape of the axial profiles of the cross‐sectional average solids holdup changes with solids fluxes. Under high‐flux conditions, the shapes of the profiles are quite different from those under low‐flux conditions. It is clear that solids holdup increases with the increase of solids fluxes. While the superficial gas velocities have no obvious influence on the shape of the axial profiles of the cross‐sectional average solids holdup under given solids flux for both risers, solids holdup decreases with the increase of superficial gas velocity under all solids inventories. The solids inventory and riser diameter have little influence on the shape of the profile, but the solids holdup is higher with larger bed diameter and/or larger solids inventory. Meanwhile, the solids inventory and riser diameter have important influence on the maximum value of operating solids fluxes of the system. The maximum of solids fluxes increases with the increase of solids inventory, and decreases with the increase of riser diameter.
CFD Modeling of a Bubble Column Reactor Carrying out a Consecutive A → B → C Reaction
Authors: van Baten J.M. , Krishna R.
Published: March 2004

In this paper, we develop a CFD model for describing a bubble column reactor for carrying out a consecutive first‐order reaction sequence A → B → C. Three reactor configurations, all operating in the homogeneous bubbly regime, were investigated: (I) column diameter DT = 0.1 m, column height HT = 1.1 m, (II) DT = 0.1 m, HT = 2 m, and (III) DT = 1 m, HT = 5 m. Eulerian simulations were carried out for superficial gas velocities UG in the range of 0.005–0.04 m/s, assuming cylindrical axisymmetry. Additionally, for configurations I and III fully three‐dimensional transient simulations were carried out for checking the assumption of cylindrical axisymmetry. For the 0.1 m diameter column (configuration I), 2‐D axisymmetric and 3‐D transient simulations yield nearly the same results for gas holdup ϵG, centerline liquid velocity VL(0), conversion of A, χA, and selectivity to B, SB. In sharp contrast, for the 1 m diameter column (configuration III), there are significant differences in the CFD predictions of ϵG, VL(0), χA, and SB using 2‐D and 3‐D simulations; the 2‐D strategies tend to exaggerate VL(0), and underpredict ϵG, χA, and SB. The transient 3‐D simulation results appear to be more realistic. The CFD simulation results for χA and SB are also compared with a simple analytic model, often employed in practice, in which the gas phase is assumed to be in plug flow and the liquid phase is well mixed. For the smaller diameter columns (configurations I and II) the CFD simulation results for χA are in excellent agreement with the analytic model, but for the larger diameter column the analytic model is somewhat optimistic. There are two reasons for this deviation. Firstly, the gas phase is not in perfect plug flow and secondly, the liquid phase is not perfectly mixed. The computational results obtained in this paper demonstrate the power of CFD for predicting the performance of bubble column reactors. Of particular use is the ability of CFD to describe scale effects.
Dynamic Analysis of Diffusion and Adsorption of Water‐Miscible and Water‐Immiscible Organic Vapors in Soil
Authors: Kalender M. , Akosman C.
Published: March 2004

A dynamic analysis of the diffusion and adsorption of water‐miscible volatile organic compounds (methanol and acetone) and water‐immiscible volatile organic compounds (benzene and toluene) in a soil pellet has been performed experimentally by using the single pellet moment technique. The experiments were conducted in a one‐sided single pellet adsorption cell at a temperature of 30 °C and varying relative humidities (0, 20, and 40 %). The results obtained with dry and wet systems showed that volatile organic tracers were adsorbed reversibly onto the soil. The overall adsorption equilibrium constants of both water‐miscible and water immiscible volatile organic compounds decreased with relative humidity. The sorption of water‐immiscible VOCs (benzene) onto soil was found to be much less than that of water‐miscible VOCs (methanol). The effective diffusivity of water‐immiscible volatile organic vapor (benzene) in the soil did not show a considerable change with relative humidity. In contrast, there was an appreciable change in the effective diffusivity for water‐miscible VOCs (methanol) with moisture.
Method of Laser‐induced Breakdown Detection and Application Examples
Authors: Bundschuh T. , Wagner T. , Weber M. , Köster R.
Published: March 2004

The Laser‐induced Breakdown Detection is a rather novel and highly sensitive method for the non‐invasive determination of both the concentration and the number‐weighted mean diameter of nanoparticles (colloids) in liquids. Compared to other methods the limit of detection is lower by several orders of magnitude. Their high surface to masse ratio results in a large sorption capacity that on the one hand offers great technical possibilities, on the other hand colloidal transport of pollutants can be a serious environmental problem.
Influence of the Column Design on the HPLC (High Performance Liquid Chromatography) Process
Authors: Boysen H. , Wozny G. , Guiochon G.
Published: March 2004

In process chromatography, calculations are used to support the setup of separation systems. Many contributions dealing with the calculation of the effects of the thermodynamics and mass transfer kinetics involved in the chromatographic have been established. Unfortunately, the production capacity in preparative chromatography can only be increased by increasing the column diameter.
High‐Pressure Homogenization as a Process for Emulsion Formation
Authors: Schultz S. , Wagner G. , Urban K. , Ulrich J.
Published: March 2004

Emulsions find a wide range of application in industry and daily life. In the pharmaceutical industry lipophilic active ingredients are often formulated in the disperse phase of oil‐in‐water emulsions. Milk, butter, and margarine are examples of emulsions in daily life. In the metal processing industry emulsions are used in the form of coolants. Emulsions can be produced with different systems. In the following, the process of high‐pressure homogenization is briefly compared to other common mechanical emulsification systems. To facilitate the selection of an emulsification system, the influence of the most important parameters of the emulsion formulation on the resulting mean droplet diameter in the most prevalent continuous emulsification systems is outlined. Subsequently, the most common high‐pressure homogenization systems are discussed in detail. On the basis of data from the literature and own experimental results the described high‐pressure homogenization systems will be compared regarding their attainable mean droplet diameter. It shows that homogenizers with a relatively simple geometry like the patented “combined orifice valve” (Kombi‐Blende) attain the smallest mean droplet diameters. The advantage of the “combined orifice valve” compared to other high‐pressure homogenization systems is not more efficient droplet disruption but rather more efficient droplet stabilization against coalescence immediately after the droplet breakup. The greatest research potential concerning the development of new high‐pressure homogenization systems is still to be seen in improvements of droplet stabilization, i.e., the reduction of coalescence.
Sequence‐Specific Molecular Lithography Towards DNA‐Templated Electronics
Authors: Keren K. , Braun E.
Published: March 2004

Recent advances in the realization of individual molecular‐scale devices [1,2] highlight the integration of individual devices into large‐scale functional circuits as the major challenge. DNA‐programmed assembly is a promising avenue in that direction due to the large amount of information that can be coded into the molecules and the ability to translate that information into physical constructs [3]. Large‐scale DNA‐templated electronics require, however, complex manipulation of double‐stranded DNA (dsDNA) molecules, as well as patterning of the electrical properties instilled to them by, e.g., metallization. To that end, sequence‐specific molecular lithography on single DNA molecules has been developed [4]. This was achieved by harnessing the exquisite homologous recombination process of the RecA protein. Sequence‐specific patterning of the metal coating of DNA molecules, localization of arbitrary labeled molecular objects at any desired dsDNA address without prior modifications, and generation of molecularly accurate stable dsDNA‐dsDNA junctions are demonstrated. The information encoded in the DNA molecules directs the lithographic process in analogy to the masks used in conventional microelectronics. The RecA protein provides the assembling capabilities, as well as the resist function.
Promoting Prevention: Evaluating a Multi‐agency Initiative of Youth Consultation and Crime Prevention in Swansea
Authors: Case Stephen , Haines Kevin
Published: March 2004

The multi‐agency, multiple intervention Promoting Prevention initiative to prevent youth offending in Swansea was evaluated with a computer‐based interactive questionnaire with 580 young people (aged 11–18). Results indicate that multiple exposure to risk factors within the main domains of the young person's life (for example, family, school) significantly increases the likelihood that a young person will become involved in problem behaviours. In contrast, exposure to multiple protective factors decreases the likelihood of these behaviours. Evaluation indicates that Promoting Prevention's consultative methodology is an empowering and engaging way of targeting interventions to promote positive behaviours and prevent anti‐social behaviour in young people.
Management of T1–T2 glottic carcinomas
Authors: Mendenhall William M. , Werning John W. , Hinerman Russell W. , Amdur Robert J. , Villaret Douglas B.
Published: March 2004

T1–T2 glottic carcinomas may be treated with conservative surgery or radiotherapy. The goals of treatment are cure and laryngeal voice preservation. The aim of the current study was to review the pertinent literature and discuss the optimal management of early‐stage laryngeal carcinoma. Literature review indicated that the local control, laryngeal preservation, and survival rates of patients were similar after transoral laser resection, open partial laryngectomy, and radiotherapy. Voice quality depended on the extent of resection for patients undergoing surgery; results for patients undergoing laser resection for limited lesions were comparable to the corresponding results for patients receiving radiotherapy, whereas open partial laryngectomy yielded poorer results. Costs were similar for laser resection and radiotherapy, but open partial laryngectomy was more expensive. Patients with well defined lesions suitable for transoral laser excision with a good functional outcome were treated with either laser or radiotherapy. The remaining patients were optimally treated with radiotherapy. Open partial laryngectomy was reserved for patients with locally recurrent tumors. Cancer 2004. © 2004 American Cancer Society.
Discrepancies among patients, family members, and physicians in Korea in terms of values regarding the withholding of treatment from patients with terminal malignancies
Authors: Oh Do‐Youn , Kim Jee‐Eun , Lee Chee‐Hun , Lim Jae‐Sung , Jung Kyung‐Hye , Seog Heo Dae , Bang Yung‐Jue , Kyeong Kim Noe
Published: March 2004

BACKGROUND

The role of the physician in end‐of‐life decision‐making is complicated. To analyze the controversies that surround therapeutic decision‐making and the withholding of life‐sustaining treatments, the authors compared values regarding therapeutic intervention that were held by physicians and family members of patients with terminal malignancies.

METHODS

One hundred fourteen patients with either advanced‐stage or terminal disease were enrolled in the current study. Questionnaires were administered to the duty physician and to patients' family members. The questions covered issues such as the use of new anticancer agents with only partial efficacy (15%) and the use of opioid analgesics, intravenous nutrition, feeding tubes, antibiotics, and hemodialysis. In addition, participants were asked about the administration of cardiopulmonary resuscitation (CPR) and the use of ventilators, and when the patient's family consented, the same questionnaire was administered to the patient as well.

RESULTS

Seventeen of 114 families refused to answer the questionnaire. Of the 97 available families, only 14 permitted access to the patient. Of those 14 patients, 5 refused to complete the questionnaire. Overall, 100% of families and 87% of patients had some knowledge regarding malignant disease, but only 69% of families and 37% of patients clearly understood the stage of the patient's disease. The use of a new agent with only partial efficacy (≈ 15%) was accepted by 41% of physicians and by 60% of families. The concordance rate between patients' physicians and family members regarding the same patient was 42%. The rankings of the acceptance of treatment by physicians were as follows: opioid analgesics, 100%; antibiotics, 91%; feeding tube, 87%; and intravenous nutrition, 78%. The rankings of the same items by family members were as follows: opioid analgesics, 92%; antibiotics, 89%; intravenous nutrition, 86%; and feeding tube, 75%. The concordance rates between patients' physicians and families were lowest for ventilator application (39%) and CPR (47%).

CONCLUSIONS

Values held on issues such as therapeutic decision‐making and the withholding of life‐sustaining treatment for patients with terminal malignancies were discordant between physicians and family members. To resolve controversies regarding the role of the physician in end‐of‐life decision‐making, the values of physicians, patients, and family members should be considered in the final decision‐making process. Cancer 2004. © 2004 American Cancer Society.
Diagnostic accuracy of fine‐needle aspiration cytology and frozen section in primary parotid carcinoma
Authors: Zbären Peter , Nuyens Michel , Loosli Heinz , Stauffer Edouard
Published: March 2004

BACKGROUND

The low incidence and histologic heterogeneity of primary parotid carcinomas makes it difficult to evaluate the value of preoperative fine‐needle aspiration cytology (FNAC) and intraoperative frozen section (FS) analysis. In the current study, the authors reviewed a single institution's experience regarding the preoperative and intraoperative diagnostic value of FNAC and FS in primary salivary gland carcinomas.

METHODS

Between January 1990 and December 2002, 108 primary parotid carcinomas were resected at the Department of Otorhinolaryngology, Head and Neck Surgery at the University of Berne, Inselspital (Berne, Switzerland). Included in the study were a total of 101 carcinomas with preoperative FNAC results in 88 tumors and/or intraoperative FS results in 45 tumors. In a retrospective study, the results of FNAC and FS were analyzed and compared with the corresponding histopathologic diagnoses.

RESULTS

The cytologic findings were true‐positive for malignancy in 63 tumors (72%), false‐negative in 22 tumors (25%), and nondiagnostic in 3 tumors (3%). The tumor grading was correct in 29 of 63 tumors (46%), and the exact tumor typing was correct in 27 of 63 (43%) true‐positive tumors. The FS findings were true‐positive for malignancy in 43 of 45 tumors (96%), the tumor grading was correct in 35 of 45 tumors (78%), and the tumor typing was correct in 32 of 45 tumors (71%). Overall, at the time of surgery, of the 101 parotid carcinomas, the tumor was known to be malignant in 83 tumors (82%), and the correct grade and the exact tumor type were known in 55 tumors (54%) and 48 tumors (48%), respectively.

CONCLUSIONS

FNAC recognized malignancy in 72% of tumors, but it could not be relied upon to provide an accurate tumor grading or typing. Therefore, FNAC alone is not prone to determine the surgical management of primary parotid carcinomas. The current analysis showed the statistically significant superiority of FS compared with FNAC regarding the diagnosis of malignancy, tumor grading, and tumor typing in primary parotid carcinomas. Cancer 2004. © 2004 American Cancer Society.
Familial aggregation of Hodgkin lymphoma and related tumors
Authors: Goldin Lynn R. , Pfeiffer Ruth M. , Gridley Gloria , Gail Mitchell H. , Li Xinjun , Mellemkjaer Lene , Olsen Jørgen H. , Hemminki Kari , Linet Martha S.
Published: March 2004

BACKGROUND

The importance of genetic factors in the etiology of Hodgkin lymphoma (HL) has been suggested by family and population studies. However, the spectrum of malignancies associated with common genetic etiology and the effects of gender and age on familial risk have not been established.

METHODS

Diagnoses of lymphoproliferative malignancies were compared in 15,799 first‐degree relatives of 5047 patients with HL versus 32,117 first‐degree relatives of 10,078 control probands from Sweden and in 7185 first‐degree relatives of 2429 patients with HL versus 27,434 first‐degree relatives of 8,495 control probands from Denmark using marginal survival models.

RESULTS

The risk of HL in relatives of patients with HL was increased significantly in both populations, with relative risks of 3.47 (95% confidence interval [95% CI], 1.77–6.80) in Sweden and 2.55 (95% CI, 1.01–6.45) in Denmark and a pooled estimate of 3.11 (95%CI, 1.82–5.29). In Sweden, risks for relatives of patients also were increased significantly for chronic lymphocytic leukemia and non‐Hodgkin lymphoma (in males). Relative risks were higher in males compared with females and in siblings of patients compared with parents and offspring of patients. Relatives of patients with earlier‐onset disease were at higher risk for HL.

CONCLUSIONS

HL has an important familial component, which is stronger in families of affected individuals age < 40 years, in males, and in siblings, and it is shared with some (but not other) lymphoproliferative malignancies. The cumulative lifetime risks are very small, however, for the development of HL de novo or in first‐degree relatives of affected patients. Cancer 2004. Published 2004 by the American Cancer Society.
Methyl‐CpG‐binding domain 2
Authors: Zhu Yong , Spitz Margaret R. , Zhang Hui , Grossman H. Barton , Frazier Marsha L. , Wu Xifeng
Published: March 2004

BACKGROUND

MBD2, a methyl‐CpG‐binding domain 2 protein, has attracted much attention because of its role in epigenetic regulation of gene expression. In addition to transcriptional repression, MBD2 has also been shown to catalyze demethylation by directly removing methyl groups from 5‐methylcytosine residues in DNA. Although the demethylase activity of MBD2 remains controversial, reduction of MBD2 messenger RNA expression has been observed in various tumor tissue types. In the current case–control study, the authors investigated the association between MBD2 expression and bladder carcinoma risk.

METHODS

RNA was isolated from the peripheral blood lymphocytes of 98 bladder carcinoma case patients and 135 frequency‐matched control patients. MBD2 expression was measured by real‐time quantitative reverse transcription–polymerase chain reaction assays.

RESULTS

Overall, there was a significantly reduced risk associated with high levels of MBD2 expression (odds ratio [OR], 0.43; 95% confidence interval [CI], 0.21–0.90). This relation was maintained when the data were categorized according to quartile distribution for MBD2 expression (P for trend < 0.05). It is noteworthy that the protective effects were more apparent in women (OR, 0.25; 95% CI, 0.06–1.02) compared with men (OR, 0.58; 95%; CI, 0.24–1.42), in older individuals (OR, 0.12; 95% CI, 0.03–0.45) compared with younger individuals (OR, 1.16; 95% CI, 0.40–3.33), and in heavier smokers (OR, 0.40; 95% CI, 0.18–0.93) compared with lighter smokers (OR, 0.71; 95% CI, 0.18–2.86).

CONCLUSIONS

Although the underlying molecular mechanisms remain unclear, the data obtained in the current study represent the first evidence demonstrating a protective role against bladder carcinoma risk for MBD2. MBD2 expression may prevent age‐related, gender‐related, and smoking‐induced hypermethylation, which are predisposing factors for tumor development. Cancer 2004. © 2004 American Cancer Society.
p53 and p21 expression levels predict organ preservation and survival in invasive bladder carcinoma treated with a combined‐modality approach
Authors: del Muro Xavier Garcia , Condom Enric , Vigués Francesc , Castellsagué Xavier , Figueras Agnès , Muñoz Josep , Solá Judit , Soler Teresa , Capellà Gabriel , Germà Josep R.
Published: March 2004

BACKGROUND

The purpose of the current study was to evaluate the expression levels of p53, p21 and pRB as predictors of for long‐term organ preservation and survival in patients with bladder carcinoma who were treated with bladder‐sparing intent using a combined‐modality approach.

METHODS

Tumor samples from 82 consecutive patients with localized invasive bladder carcinoma treated on 3 different bladder‐sparing studies were examined for p53, p21, and pRB expression by immunohistochemical methods. Treatment consisted of transurethral resection, platinum‐based neoadjuvant chemotherapy, and, according to response, either radiotherapy or radical cystectomy. The median follow‐up duration was 55 months.

RESULTS

Positive immunoreactivity for p53, p21, and pRB was observed in 47%, 52%, and 67% of patients, respectively. Positive p53 immunoreactivity and positive p21 immunoreactivity were independent predictors of decreased survival with bladder preservation (P = 0.02 and P = 0.02, respectively) and disease‐free survival (DFS; P = 0.005 and P = 0.009, respectively) in a multivariate analysis adjusting for clinical stage, ureteral obstruction, and age. Regarding overall survival (OS), p53 overexpression was associated with poor outcome (P = 0.03), whereas the association of poor outcome with p21 expression did not reach statistical significance (P = 0.07). No association between pRB immunoreactivity and outcome was found. When the combined expression of p53 and p21 was assessed, the positive expression of both markers was a strong and unfavorable prognostic factor for survival with bladder preservation (P = 0.006), DFS (P = 0.003), and OS (P = 0.02).

CONCLUSIONS

Expression levels of p53 and p21, especially when simultaneously assessed, exhibit independent predictive value for long‐term bladder preservation and survival in patients with bladder carcinoma treated with combined‐modality therapy. These determinations could be useful in the selection of candidates for bladder‐preserving treatment. Cancer 2004. © 2004 American Cancer Society.