bluuebunny/crossref_metadata_2025_split huggingface dataset:
Flow Characteristics of the St. Jude Prosthetic Valve: An In Vitro and In Vivo Study
Authors: Yoganathan Ajit P. , Chaux Aurelio , Gray Richard J. , De Robertis Michele , Matloff Jack M. 
Published: July 2010

ABSTRACTThe St. Jude cardiac prosthetic aortic valve was evaluated in vitro and in vivo in an attempt to establish flow characteristics and to correlate them with clinical findings. In vitro, a fluid vehicle (6% Polyol V‐10, 32°C) with viscosity similar to blood (0.035 dyne‐sec/cm2) was used under conditions of steady flow through a flow chamber simulating the aortic root. Gradient, velocity, and shear stress were measured 5.79 mm, 26.79 mm, 44.79 mm, and 77.79 mm downstream from 25‐mm and 27‐mm valves using a laser‐Doppler anemometer. At 417 ml/sec, the valve gradient was 6.2 mmHg with the 25‐mm valve, and 5.2 mmHg with the 27‐mm prosthesis. Velocity was maximum at the orifice center, and wall shear stress was low (maximum 600 dyne/cm2).In vivo, six patients with 25‐mm St. Jude aortic valves were studied within 48 hours after surgery to determine cardiac output, valve flow, and gradient. The gradient was 3.3 ± 1.9 mmHg (M ± SD) at 249 ± 96 ml/sec and the effective valve area was as large as the geometric area (2.58 vs. 3.09 cm2).Thus, flow through the St. Jude valve is unobstructed and central, has low turbulence, and achieves optimal effective valve area for a given available orifice area.
Experimental and Clinical Ventricular Bypass During Acute Heart Failure
Authors: Lokshin Leonid S. , Osipov Valentin P. , Knjazeva Galina , Rogov Konstantin A. , Lepilin Mikhail G. , Arseniev Sergei B. , Romanov Vladimir A. , Leonova Svetlana A. 
Published: July 2010

ABSTRACTMechanical support of the failing heart in the form of bypass of the left and right ventricles by roller pumps was used in 25 dogs with model cardiogenic shock. Early application of left ventricular bypass in acute heart failure normalizes the myocardial bioenergy state and promotes reversible changes in myocardial infrastructure as demonstrated by an increased surface area of mitochondrial cristae. On the basis of hemodynamics and morphology, we conclude that pump‐aided bypass of ventricles without synchronization is a simple and effective method of circulation assistance.Mechanical support duration from 1 to 138 hours has been used in 10 patients following corrective heart surgery.
A Mysterious Extrafraction in the Gamma Area of Protein Electrophoresis in Dialysis Patients is Found to be Fibrinogen
Authors: Hombrouckx R. , Gilbert I. 
Published: July 2010

ABSTRACTThe appearance of a heretofore unnoticed extrafraction in the gamma protein electrophoresis of 17 dialyzed patients was linked to the modified Shaldon dialysis catheter. Medication interference, infection, and immunological or hematological disease as causative factors were ruled out. After initial contradictory results, the extrafraction was determined to be fibrinogen, present because of the slow release of heparin contained in the catheter, so that electrophoresis was performed on plasma instead of on serum.
High‐Pressure Portable Pneumatic Drive Unit
Authors: Hete B. F. , Savage M. , Batur C. , Smith W. A. , Golding L. A. R. , Nosé Y. 
Published: July 2010

Abstract: The left ventricular assist device (LVAD) of the Cleveland Clinic Foundation (CCF) is a single‐chamber assist pump, driven by a high‐pressure pneumatic cylinder. A low‐cost, portable driver that will allow cardiac care patients, with a high‐pressure pneumatic ventricle assist, more freedom of movement has been developed.The compact and light‐weight configuration can provide periods of 2 h of freedom from a fixed position driver and does not use exotic technology.
A Compact Centrifugal Pump for Cardiopulmonary Bypass
Authors: Sasaki Tatsuya , Jikuya Tomoaki , Aizawa Takeshi , Shiono Motomi , Sakuma Ichiro , Takatani Setsuo , Glueck Julia , Noon George P. , Nosé Yukihiko , DeBakey Michael E. 
Published: July 2010

Abstract: A majority of the cardiopulmonary bypass (CPB) systems still utilize bulky roller pumps. A direct‐drive small centrifugal pump intended for second‐generation CPB pump has been developed. The pump has a 50 mm diameter impeller and provides a 6 L/min flow at 3,000 rpm against 300 mm Hg. A flexible drive shaft allows us to separate the pump head from the console resulting in easier manipulation. An in vitro study showed that the pump generated less hemolysis (index of hemolysis = 0.0011, comparable to the value for Bio‐medicus BP‐80).To improve blood flow around the shaft‐seal region and to reduce thrombus formation around the shaft, six holes were drilled through the impeller. In biventricular bypass experiments using calves, our pump demonstrated excellent antithrombogenicity and durability for 48 h. And the compact and atraumatic centrifugal pump system showed excellent performance and easy manipulation under acfual CPB conditions in animal.
Adsorption of Hepatitis C Virus Particles Onto the Dialyzer Membrane
Authors: Hayashi Haruyuki , Okuda Kunio , Yokosuka Osamu , Kobayashi Susumu , Yokozeki Kazuo , Ohtake Yoshio , Irie Yasubumi 
Published: July 2010

Abstract: It was recently found that the blood level of hepatitis C virus (HCV) RNA is significantly reduced after each dialysis procedure in patients on chronic hemodialysis. This study was designed to elucidate the mechanism for this phenomenon. In two patients with high serum levels of HCV RNA, the filtrate through the dialyzer (TF‐α, Teijin Co., Tokyo, Japan) was analyzed for viral RNA using the polymerase chain reaction. At the end of dialysis, the filter was washed with saline, and during the saline washing, aliquots were taken for quantification of RNA by the branched DNA method. The HCV core antigen was quantified as a measure of viral particles, and hemoglobin was also measured for correcting for blood contamination. After the clearance of the blood, the filter was washed with guanidinium isothiocyanate, and the recovery of RNA was measured. The filtrate did not contain detectable RNA.The saline washing of the filter after dialysis contained a significant amount of RNA. Washing with guanidinium isothiocyanate of the thoroughly saline washed filter also recovered a significant amount of RNA. During saline dashing, the recovery of RNA in the washing was much delayed behind that of hemoglobin, suggesting the adsorption of the former onto the filter membrane. There was a discordant recovery of RNA and HCV core antigen in the washing, the recovery of the former being delayed behind that of the latter. These results indicate that viral particles are adsorbed onto the inner surface of the filter membrane during dialysis. Some of these adsorbed viral particles are perhaps destroyed by hydraulic pressure applied to blood for dialysis.
Physiological Control of a Rotary Blood Pump With Selectable Therapeutic Options: Control of Pulsatility Gradient
Authors: Arndt Andreas , Nüsser Peter , Graichen Kurt , Müller Johannes , Lampe Bernhard 
Published: July 2010

AbstractA control strategy for rotary blood pumps meeting different user‐selectable control objectives is proposed: maximum support with the highest feasible flow rate versus medium support with maximum ventricular washout and controlled opening of the aortic valve (AoV). A pulsatility index (PI) is calculated from the pressure difference, which is deduced from the axial thrust measured by the magnetic bearing of the pump. The gradient of PI with respect to pump speed (GPI) is estimated via online system identification. The outer loop of a cascaded controller regulates GPI to a reference value satisfying the selected control objective. The inner loop controls the PI to a reference value set by the outer loop. Adverse pumping states such as suction and regurgitation can be detected on the basis of the GPI estimates and corrected by the controller. A lumped‐parameter computer model of the assisted circulation was used to simulate variations of ventricular contractility, pulmonary venous pressure, and aortic pressure. The performance of the outer control loop was demonstrated by transitions between the two control modes. Fast reaction of the inner loop was tested by stepwise reduction of venous return. For maximum support, a low PI was maintained without inducing ventricular collapse. For maximum washout, the pump worked at a high PI in the transition region between the opening and the permanently closed AoV. The cascaded control of GPI and PI is able to meet different control objectives and is worth testing in vitro and in vivo.
Magnetic Drive System for a New Centrifugal Rotary Blood Pump
Authors: Hilton Andrew , Tansley Geoff 
Published: July 2010

AbstractThe purpose of this investigation was to design a novel magnetic drive and bearing system for a new centrifugal rotary blood pump (CRBP). The drive system consists of two components: (i) permanent magnets within the impeller of the CRBP; and (ii) the driving electromagnets. Orientation of the magnets varies from axial through to 60° included out‐lean (conical configuration). Permanent magnets replace the electromagnet drive to allow easier characterization. The performance characteristics tested were the axial force of attraction between the stator and rotor at angles of rotational alignment, ∅, and the corresponding torque at those angles. The drive components were tested for various magnetic cone angles, θ. The test was repeated for three backing conditions: (i) non‐backed; (ii) steel‐cupped; and (iii) steel plate back‐iron, performed on an Instron tensile testing machine. Experimental results were expanded upon through finite element and boundary element analysis (BEM). The force/torque characteristics were maximal for a 12‐magnet configuration at 0° cone angle with steel‐back iron (axial force = 60 N, torque = 0.375 Nm). BEM showed how introducing a cone angle increases the radial restoring force threefold while not compromising axial bearing force. Magnets in the drive system may be orientated not only to provide adequate coupling to drive the CRBP, but to provide significant axial and radial bearing forces capable of withstanding over 100 m/s2 shock excitation on the impeller. Although the 12 magnet 0° (θ) configuration yielded the greatest force/torque characteristic, this was seen as potentially unattractive as this magnetic cone angle yielded poor radial restoring force characteristics.
The BiVACOR Rotary Biventricular Assist Device: Concept and In Vitro Investigation
Authors: Timms Daniel , Fraser John , Hayne Mark , Dunning John , McNeil Keith , Pearcy Mark 
Published: July 2010

AbstractThe BiVACOR is a novel rotary Biventricular Assist Device (BiVAD) undergoing development to treat global end‐stage heart failure. The design includes left and right vanes positioned on a shared rotating hub to form a double‐sided magnetically and hydrodynamically suspended centrifugal impeller.The performance of the device was assessed in a pulsatile mock circulation loop replicating end‐stage biventricular heart failure, and was shown to restore flow from pathological (2 L/min) to normal levels (5 L/min). A novel technique to balance the left/right outflow of the BiVAD was also investigated, for which a maximum relative left to right outflow differential of 1.8 L/min was achieved at normal physiologic afterloads.The in vitro results encourage device progression to in vivo animal studies. Successful development of this BiVAD will provide a suitably miniature device for patients who require biventricular assistance.
Heat Shock Protein70: A New Marker for Subsequent Atrial Fibrillation Development?
Authors: Oc Mehmet , Ucar Halil Ibrahim , Pinar Asli , Akbulut Birkan , Oc Bahar , Akyon Yakut , Kanbak Meral , Dogan Riza 
Published: July 2010

AbstractAtrial fibrillation (AF) is a common arrhythmia, after cardiac surgery, and it is associated with a twofold increase in cardiovascular mortality and morbidity. Reperfusion injury and inflammation associated with cardiac surgery are thought to be involved in its pathogenesis. Heat shock proteins (HSPs) are a family of chaperone proteins which assist in preservation of cellular integrity by maintaining proteins in their correctly folded state. The aim of this study was to investigate pre‐postoperative heat shock protein70 (HSP70) and high‐sensitivity C‐reactive protein in serum from patients in preoperative sinus rhythm. We prospectively screened 45 consecutive patients admitted to the hospital for elective coronary artery bypass surgery (CABG). Electrocardiogram characteristics and cardiovascular risk profile were documented. Pre‐ and postoperative blood samples were collected. HSP70 value was 8.9 ± 4.8 ng/mL in Group A (study group) preoperatively and decreased to 7.7 ± 7.0 ng/mL postoperatively. In contrast, preoperative value of HSP70 was 4.2 ± 2.2 ng/mL and decreased to 2.7 ± 2.6 ng/mL postoperatively in Group B (control group). Statistical analysis showed significant difference regarding preoperative HSP70 levels in Group A compared to Group B. To our knowledge, with this study, the association of pre‐ and postoperative circulating HSP70 with postoperative AF was demonstrated for the first time.
Numerical Simulations of Blood Flow in Artificial and Natural Hearts With Fluid–Structure Interaction
Authors: Doyle Matthew G. , Vergniaud Jean‐Baptiste , Tavoularis Stavros , Bourgault Yves 
Published: July 2010

AbstractThis article describes two ongoing numerical studies of fluid–structure interaction in the cardiovascular system: an idealized pulsatile ventricular assist device (VAD), consisting of two fluid chambers separated by a flexible diaphragm; and blood flow and heart wall motion during passive filling of a canine heart. Simulations have been performed for the VAD and compared with the results of a previous study and to our own preliminary experimental results. Detailed measurements of the flow field in the VAD model and additional simulations are in progress. Preliminary simulations using both an idealized model of the natural heart as well as a realistic model have identified the limitations of the current numerical methods in dealing with large three‐dimensional deformations. Ongoing research aims at extending the range of simulations to include large deformations and to incorporate an anisotropic material model for the heart wall to account for the muscle fibers.
Pharmacology of the β‐Carboline FG‐7142, a Partial Inverse Agonist at the Benzodiazepine Allosteric Site of the GABAA Receptor: Neurochemical, Neurophysiological, and Behavioral Effects
Authors: Evans Andrew K. , Lowry Christopher A. 
Published: July 2010

ABSTRACTGiven the well‐established role of benzodiazepines in treating anxiety disorders, β‐carbolines, spanning a spectrum from full agonists to full inverse agonists at the benzodiazepine allosteric site for the GABAA receptor, can provide valuable insight into the neural mechanisms underlying anxiety‐related physiology and behavior. FG‐7142 is a partial inverse agonist at the benzodiazepine allosteric site with its highest affinity for the α1 subunit‐containing GABAA receptor, although it is not selective. FG‐7142 also has its highest efficacy for modulation of GABA‐induced chloride flux mediated at the α1 subunit‐containing GABAA receptor. FG‐7142 activates a recognized anxiety‐related neural network and interacts with serotonergic, dopaminergic, cholinergic, and noradrenergic modulatory systems within that network. FG‐7142 has been shown to induce anxiety‐related behavioral and physiological responses in a variety of experimental paradigms across numerous mammalian and non‐mammalian species, including humans. FG‐7142 has proconflict actions across anxiety‐related behavioral paradigms, modulates attentional processes, and increases cardioacceleratory sympathetic reactivity and neuroendocrine reactivity. Both acute and chronic FG‐7142 treatment are proconvulsive, upregulate cortical adrenoreceptors, decrease subsequent actions of GABA and β‐carboline agonists, and increase the effectiveness of subsequent GABAA receptor antagonists and β‐carboline inverse agonists. FG‐7142, as a partial inverse agonist, can help to elucidate individual components of full agonism of benzodiazepine binding sites and may serve to identify the specific GABAA receptor subtypes involved in specific behavioral and physiological responses.
The quality of fresh‐frozen plasma produced from whole blood stored at 4°C overnight
Authors: Cardigan Rebecca , Lawrie Andrew S. , Mackie Ian J. , Williamson Lorna M. 
Published: July 2010

BACKGROUND: The aim of this study was to assess whether the quality of FFP produced from whole blood stored at 4°C overnight is adequate for its intended purpose.STUDY DESIGN AND METHODS: Fresh‐frozen plasma (FFP) separated from whole blood (n = 60) leukodepleted (LD) after storage at 4°C overnight (18‐24 hr from donation, Day 1 FFP) was compared with that LD within 8 hours of donation (Day 0 FFP, the current standard method).RESULTS: In more than 95 percent of Day 1 FFP units, levels of factor (F) II, FV, FVII, FVIII, F IX, FX, FXI, and FXII were greater than 0.50 U per mL except for von Willebrand factor (VWF) antigen and FVIII, where 92 and 87 percent of units, respectively, contained greater than 0.50 IU per mL. Compared with historical data on FFP stored for 8 hours, fibrinogen, FV, FVIII, and FXI were reduced by 12, 15, 23, and 7 percent, respectively, but other factors were not significantly reduced. Levels of VWF‐cleaving protease activity were not different between FFP prepared from paired units of blood (n = 3) held for 8 or 24 hours, but were below the reference range in an additional 2 of 6 units held for 24 hours. The activities of protein S, protein C, antithrombin III, and α2‐antiplasmin were reduced by less than 10 percent in Day 1 FFP (n = 20), but with final levels above the lower limit of the normal range in greater than 95 percent of units. Activated FXII antigen was not significantly raised in plasma stored for 18 to 24 hours, but levels of prothrombin fragment 1 + 2 were slightly increased (0.88 ng/mL, 18‐24 hr; 0.65 ng/mL, < 8 hr).CONCLUSION: These data suggest that there is good retention of relevant coagulation factor activity in plasma produced from whole blood stored at 4°C for 18 to 24 hours and that this would be an acceptable product for most patients requiring FFP.
Marathon Running as a Cause of Troponin Elevation: A Systematic Review and Meta‐Analysis
Authors: REGWAN STEVEN , HULTEN EDWARD A. , MARTINHO SHAUN , SLIM JENNIFER , VILLINES TODD C. , MITCHELL JOSHUA , SLIM AHMAD M. 
Published: July 2010

Background:
Cardiac troponin (cTn) has high sensitivity and specificity for myocardial injury in acute coronary syndrome. Our objective was to review the published literature regarding the incidence of cTn elevations in marathon runners.
Methods:
Systematic review and meta‐analysis of observational studies published before September 2009. We included studies of patients who had completed a marathon and had serum cTn levels within 24 hours. The primary outcome was the odds ratio for conversion of a normal pre‐marathon cTn to an elevated post‐marathon cTn. Secondary outcomes included the pooled prevalence of cTn elevation and comparison of the odds ratio for post‐marathon elevation of cTnI versus cTnT.
Results:
Sixteen studies of 939 participants met criteria for inclusion. The mean age was 39 ± 4 years and patients were 74 ± 14% male. There were 6 pre‐marathon cTn elevations and 579 post‐race elevations. The pooled odds ratio for converting from a normal pre‐race to an elevated post‐race cTn was 51.84 (95% CI 16–168, I2= 66%, P < 0.001). The pooled incidence of a post‐marathon cTn elevation was 51% (95% CI 33–69, I2= 98%, P < 0.001) of all runners. For the primary outcome there was no significant publication bias. Age and gender were not associated, but publication date and assay sensitivity was associated with cTn elevation. cTnI was less commonly elevated versus cTnT.
Conclusions:
The available data demonstrate that cTn levels are frequently elevated after a marathon with unclear cardiovascular significance. This elevation of cTn appears to be consistent among a diverse patient population. (J Interven Cardiol 2010;23:443–450)
Immunoprofiling of patients with chronic myeloid leukemia at diagnosis and during tyrosine kinase inhibitor therapy
Authors: Rohon Peter , Porkka Kimmo , Mustjoki Satu 
Published: July 2010

AbstractTyrosine kinase inhibitors (TKIs) are the current standard treatment in chronic myeloid leukemia (CML). In addition to the BCR‐ABL target oncoprotein, they also inhibit off‐target kinases (e.g. c‐KIT, TEC, SRC), some of which have physiological functions in immune responses. In vitro studies have implied immunosuppressive effects of TKI treatment. As comprehensive in vivo data are missing, we aimed at analyzing the detailed immunoprofile of patients with CML at diagnosis and during therapy. We collected 88 peripheral blood (PB) and 73 bone marrow (BM) samples from 54 patients with CML at diagnosis, during imatinib and dasatinib therapies. Leukocytes and lymphocyte subclasses were analyzed with an extensive flow cytometry panel including markers for activation, differentiation and memory status. At diagnosis, a lower proportion of B cells and dendritic cells and an increased amount of NKT‐like cells were detected in the BM. During imatinib therapy, all these changes normalized and the immunoprofile resembled healthy controls. However, dasatinib patients were clearly divided into two distinct groups: one similar to healthy controls and the other showing immunoactivation characterized by significant elevations of CD8+, NK‐ and NKT‐like cells in PB. T cells of the latter group strongly expressed CD57+, HLA‐DR and CD45RO and had low CD62L antigen levels characteristic of late memory cytotoxic lymphocytes. Our results indicate that while both TKIs show immunosuppressive effects in vitro, they have a significant and differential effect on the numbers and proportions of immune effector cells in vivo. In particular, in a distinct subgroup of dasatinib‐treated patients, immune reactivity is markedly enhanced warranting careful follow‐up.
Assessment of bone marrow involvement in non‐Hodgkin’s lymphomas: comparison between histology and flow cytometry
Authors: Merli Michele , Arcaini Luca , Boveri Emanuela , Rattotti Sara , Picone Cristina , Passamonti Francesco , Tenore Annamaria , Sozzani Laura , Lucioni Marco , Varettoni Marzia , Rizzi Silvia , Morello Lucia , Ferretti Virginia , Pascutto Cristiana , Paulli Marco , Lazzarino Mario 
Published: July 2010

AbstractBone marrow (BM) examination is essential in the staging of non‐Hodgkin’s lymphoma (NHL) patients. Few studies have compared BM histologic findings with results of flow cytometric (FC) analysis. We analyzed the incidence and patterns of histologic BM involvement in a series of 753 patients with NHL. For 498 patients, a concurrent FC analysis on BM was available. Histologic involvement was detected at diagnosis in 311/753 (41%) patients. By FC, BM involvement was clearly detected in 150/498 (30%). After excluding 12 cases with equivocal histology, concordance between the two methods was detected in 411 (85%) cases (27% BMB+/FC+; 58% BMB−/FC−), while discordance was present in 75 (15%) (P < 0.001): 58 cases (12%) were BMB+/FC− and 17 (3%) were BMB−/FC+. Discordance was more frequent in FL and in lymphoplasmacytic lymphoma (LPL). These data demonstrate that the two methods are comparable in qualitative assessment of BM involvement in NHL, with the exception of FL and LPL. In FL, diffuse large B‐cell lymphoma (DLBCL) and LPL, FC underestimates the extent of infiltrate with respect to histology.