bluuebunny/crossref_metadata_2025_split huggingface dataset:
Platelet function under high‐shear conditions from platelet concentrates
Authors: Jilma‐Stohlawetz Petra , Horvath Michaela , Eichelberger Beate , Koren Daniela , Jilma Bernd , Panzer Simon 
Published: September 2007

BACKGROUND: Platelet (PLT) collection and storage affect the functional capacity of PLTs in PLT concentrates (PCs). Therefore, PLTs' functional quality should be studied before transfusion.STUDY DESIGN AND METHODS: PCs (n = 15) were collected by a standard apheresis procedure (Trima, Gambro BCT) and were stored for 7 days. Samples were taken to assess PLT adhesion and aggregate formation by a cone and plate analyzer (Impact‐R, DiaMed) on Days 1, 3, 5, and 7 after harvesting. This device allows testing PLT function under high‐shear stress close to physiologic conditions. Concomitantly, P‐selectin expression and the residual responsiveness to TRAP‐6 were determined by flow cytometry.RESULTS: PLT adhesion, as measured by surface coverage, decreased during the entire observation period; likewise, the size of aggregates was significantly lower on Days 5 and 7 compared to Day 1 (p < 0.02). P‐selectin expression increased from Day 5 to Day 7 (p < 0.04), whereas TRAP‐6–inducible expression remained stable until Day 5 of storage and decreased significantly on Day 7 (p = 0.04).CONCLUSIONS: Our results show that high‐shear–induced PLT adhesion and aggregation on the polystyrene surface deteriorate upon storage, suggesting decreased PLT function in vivo. Thus, the Impact‐R may be a useful tool to assess the functional capacity of PLTs under various PLT harvesting and storage procedures.
Automated collection of double red blood cell units with a variable‐volume separation chamber
Authors: AuBuchon James P. , Dumont Larry J. , Herschel Louise , Roger Jill , Beddard Rachel L. , Taylor Harry L. , Whitley Pamela H. , Sawyer Sherrie L. , Graminske Sharon , Martinson Karen , Dora Ross , Heldke Sybil , Adamson John , Rose Leslie E. 
Published: September 2007

BACKGROUND: Automated collection of blood components offers multiple advantages and has prompted development of portable devices. This study sought to document the biochemical and hematologic properties and in vivo recovery of red cells (RBCs) collected via a new device that employed a variable‐volume centrifugal separation chamber.STUDY DESIGN AND METHODS: Normal subjects (n = 153) donated 2 units of RBCs via an automated blood collection system (Cymbal, Haemonetics). Procedures were conducted with wall outlet power (n = 49) or the device's battery source (n = 104). Units were collected with or without leukoreduction filtration and were stored in AS‐3 for 42 days. The units were assessed via standard biochemical and hematologic tests before and after storage, and 24 leukoreduced (LR) and 24 non‐LR RBCs were radiolabeled on Day 42 with Na251CrO4 for autologous return to determine recovery at 24 hours with concomitant determination of RBC volume via infusion of 99mTc‐labeled fresh RBCs.RESULTS: Two standard RBC units (targeted to contain 180 mL of RBCs plus 100 mL of AS‐3) could be collected in 35.7 ± 2.0 minutes (n = 30) or 40.3 ± 2.7 minutes for LR RBCs (n = 92). An additional 31 collections were conducted successfully with intentional filter bypassing. RBC units contained 104 ± 4.1 percent of their targeted volumes (170‐204 mL of RBCs), and LR RBCs contained 92 percent of non‐LR RBCs' hemoglobin. All LR RBCs contained less than 1 × 106 white blood cells. Mean hemolysis was below 0.8 percent (Day 42) for all configurations. Adenosine triphosphate was well preserved. Mean recovery was 82 ± 4.9 percent for RBCs and 84 ± 7.0 percent for LR RBCs.CONCLUSIONS: The Cymbal device provided quick and efficient collection of 2 RBC units with properties meeting regulatory requirements and consistent with good clinical utility.
A probabilistic model for analyzing viral risks of plasma‐derived medicinal products
Authors: Janssen Mart P. , Over Jan , Van Der Poel Cees L. , Cuijpers H. Theo M. , Van Hout Ben A. 
Published: September 2007

BACKGROUND: The prevention of transmission of viral infections by plasma‐derived medicinal products is of concern to manufacturers, legislators, and patient representative groups. Recent European legislation requires a viral risk assessment for all new marketing applications of such products.STUDY DESIGN AND METHODS: A discrete event Monte Carlo model was developed to determine the viral transmission risks of the plasma‐derived medicinal products. The model incorporates donor epidemiology, donation intervals, efficiency of screening tests for viral markers, inventory hold period, size and composition of the manufacturing pool, production time, process virus reduction capacity, and product yield. With the model, the human immunodeficiency virus (HIV) and hepatitis C virus (HCV) contamination risks of a typical hypothetical plasma product were calculated, and the sensitivity of the risk to various model variables was analyzed.RESULTS: The residual HIV and HCV risks of the finished products are linear in change with viral incidence rate and inversely linear with product yield and process virus reduction capacity. For the product analyzed in this article, the residual risk is less sensitive to changes in screening test pool size, donation frequency, and inventory hold period. There is only a limited dependency on the donation type (apheresis or whole‐blood donations) and a negligible dependency on the manufacturing pool size.CONCLUSIONS: The use of probabilistic model simulation techniques is indispensable when estimating realistic residual viral risks of plasma‐derived medicinal products. In contrast to conventional deterministic residual risk estimations, the probabilistic approach allows incorporation of specific manufacturing decisions and therefore provides the only feasible alternative for a correct assessment of residual risks.
Automated Left Ventricular Capture Management
Authors: CROSSLEY GEORGE H. , MEAD HARDWIN , KLECKNER KAREN , SHELDON TODD , DAVENPORT LYNN , HARSCH MANYA R. , PARIKH PURVEE , RAMZA BRIAN , FISHEL ROBERT , BAILEY J. RUSSELL ,   for the LVCM Study Investigators
Published: September 2007

Background:

The stimulation thresholds of left ventricular (LV) leads tend to be less reliable than conventional leads. Cardiac resynchronization therapy (CRT) requires continuous capture of both ventricles.
Objective:

The purpose of this study is to evaluate a novel algorithm for the automatic measurement of the stimulation threshold of LV leads in cardiac resynchronization systems.
Methods:

We enrolled 134 patients from 18 centers who had existing CRT‐D systems. Software capable of automatically executing LV threshold measurements was downloaded into the random access memory (RAM) of the device. The threshold was measured by pacing in the left ventricle and analyzing the interventricular conduction sensed in the right ventricle. Automatic LV threshold measurements were collected and compared with manual LV threshold tests at each follow‐up visit and using a Holter monitor system that recorded both the surface electrocardiograph (ECG) and continuous telemetry from the device.
Results:

The proportion of Left Ventricular Capture Management (LVCM) in‐office threshold tests within one programming step of the manual threshold test was 99.7% (306/307) with a two‐sided 95% confidence interval of (98.2%, 100.0%). The algorithm measured the threshold successfully in 96% and 97% of patients after 1 and 3 months respectively. Holter monitor analysis in a subset of patients revealed accurate performance of the algorithm.
Conclusion:

This study demonstrated that the LVCM algorithm is safe, accurate, and highly reliable. LVCM worked with different types of leads and different lead locations. LVCM was demonstrated to be clinically equivalent to the manual LV threshold test. LVCM offers automatic measurement, output adaptation, and trends of the LV threshold and should result in improved ability to maintain LV capture without sacrificing device longevity.
Effect of Posterolateral Left Ventricular Scar on Mortality and Morbidity following Cardiac Resynchronization Therapy
Authors: CHALIL S. , STEGEMANN B. , MUHYALDEEN S. A. , KHADJOOI K. , FOLEY P. W. , SMITH R.E.A. , LEYVA F. 
Published: September 2007

Objectives:

To determine the effect of a posterolateral (PL) left ventricular scar on mortality and morbidity following cardiac resynchronization therapy (CRT).
Methods:

Sixty‐two patients with heart failure (age 67.3 ± 9.6 yrs [mean ± SD], 45 males, New York Heart Association class [NYHA] class III or IV, left ventricular ejection fraction [LVEF]= 35%, left bundle branch block, QRS  ≥ 120 ms) underwent late gadolinium enhancement cardiovascular magnetic resonance (LGE‐CMR) for scar imaging. Patients were followed up for 741 (75–1602) days (mean [range]).
Results:

The presence of a PL scar emerged as an independent predictor of the composite endpoint of cardiovascular death or hospitalization for worsening heart failure (HR: 3.06 [1.63, 7.7, P < 0.0001]) as well as the endpoint of cardiovascular death (HR: 2.63 [1.39, 6.65], P = 0.0016). A transmural PL scar was the strongest predictor of these endpoints (both P < 0.0001). The symptomatic responder rate (improvement by ≥1 NYHA classes or ≥25% in 6‐min walking distance) was 83% in the group with non‐PL scars, but only 47% in the group with transmural PL scars (P < 0.0001). Pacing over the scar was associated with a higher mortality and morbidity than pacing outside the scar (all P < 0.05).
Conclusions:

A PL scar is associated with a worse clinical outcome following CRT, particularly if it is transmural. Pacing scarred left ventricular myocardium carries a greater risk of mortality and morbidity than pacing nonscarred myocardium.
Site Localization and Characterization of Pain During Radiofrequency Ablation of the Pulmonary Veins
Authors: ALAEDDINI JAMSHID , WOOD MARK A. , PARVEZ BABER , PATHAK VISHESH , WONG KRISTEN A. , ELLENBOGEN KENNETH A. 
Published: September 2007

Background:

Characteristics of radiofrequency (RF) lesions producing pain with an 8‐mm catheter during pulmonary vein (PV) ablation have not been prospectively studied.
Methods:

We studied 46 (30 men, age 56 ± 10 years) patients with AF who underwent RF ablation of PVs. PV isolation was achieved by using an 8F, 8‐mm Biosense™ ablation catheter (Biosense Webster, Diamond Bar, CA, USA) guided by intracardiac echocardiography (ICE). An electroanatomic map was used to document the location of all RF lesions and the time; PV location and maximum temperature of every lesion were recorded. Location of the esophagus was determined by magnetic resonance imaging prior to the procedure and by both ICE and barium swallows during procedure.
Result:

A total of 1,448 (33 ± 12) RF lesions were delivered to 180 veins. Thirty‐nine patients (85%) had at least one lesion associated with pain (mean: 8 ± 5 lesions) during ablation. The RF generator setting during lesions resulting in pain sensation was 48.6 ± 7.0 Watts and 51.5 ± 2.9°C. Maximum temperature attained at the time of pain sensation was 45.7 ± 4.2°C. By logistic regression analysis the left superior PV (OR 1.54, CI 1.06–2.24, LS vs RI, P < 0.05) and left inferior PV (OR 2.74, CI 1.79–4.19, LI vs RI, P < 0.001) location were both positively correlated with the production of pain. The location of lesions associated with pain was not near the esophagus during any of the pain‐producing lesions.
Conclusion:

Pain sensation is relatively common during RF ablation of PVs. There was no correlation between pain and the location of esophagus. Pain was more common during RF ablation of left inferior and left superior PVs.
Swallowing‐Induced Atrial Tachyarrhythmias: Prevalence, Characteristics, and the Results of the Radiofrequency Catheter Ablation
Authors: TADA HIROSHI , KASENO KENICHI , KUBOTA SHOICHI , NAITO SHIGETO , YOKOKAWA MIKI , HIRAMATSU SHIGEKI , GOTO KOJI , NOGAMI AKIHIKO , OSHIMA SHIGERU , TANIGUCHI KOICHI 
Published: September 2007

Background:

Detailed information on swallowing‐induced tachyarrhythmias has been lacking.
Methods:

The prevalence, characteristics, and results of the radiofrequency catheter ablation (RFCA) of swallowing‐induced tachyarrhythmias were examined in 544 patients with symptomatic premature atrial contractions (PACs), paroxysmal atrial tachycardia (AT), and/or paroxysmal atrial fibrillation (AF). We also conducted a search of the medical literature on swallowing‐induced tachyarrhythmias. Further, we presented an in‐depth review of the literature and investigated the published data on swallowing‐induced tachyarrhythmias.
Results:

The prevalence of swallowing‐induced tachyarrhythmias was 0.6% (three patients). An analysis of the published literature and our three cases demonstrated that (1) males predominated 9:1 over females, (2) most cases occurred over 35 years of age, (3) tachyarrhythmias occurred consistently and reproducibly shortly after each swallow, (4) 90% of the patients had PACs and/or AT as the manifesting arrhythmia, (5) the PACs provoked by swallowing usually had the same P‐wave morphology as the first beat of the AT and AF, and (6) RFCA procedures performed in five cases resulted in success with no recurrence or complications.
Conclusions:

Swallowing‐induced tachyarrhythmias are rare, but have several distinct characteristics. RFCA should be considered in appropriately selected patients with reliable inducibility because such an ablation may offer a permanent cure.
Effect of Nifekalant for Acute Conversion of Atrial Flutter: The Possible Termination Mechanism of Typical Atrial Flutter
Authors: MORITA NORISHIGE , TANAKA KEIJI , YODOGAWA KENJI , HAYASHI MEISO , AKUTSU KOICHI , YAMAMOTO TAKESHI , SATOH NAOKI , KOBAYASHI YOSHINORI , KATOH TAKAO , TAKANO TERUO 
Published: September 2007

Background:

Nifekalant is a class III antiarrhythmic drug, which is usually used for suppression of ventricular tachycardia (VT) and fibrillation. We studied the efficacy of nifekalant for acute conversion of atrial flutter (AFL) in a prospective, open label study in the intensive care unit (ICU) of cardiovascular medicine.
Methods:

This study consisted of 31 patients. Twenty‐six patients (84%) suffered from structural heart diseases. AFL was developed in 15 patients (48%) while on antiarrhythmic therapy with class IA or IC drugs (I‐AFL group) for suppressing atrial fibrillation (AF) and in the remaining patients without such drugs (S‐AFL group). Patients with prolonged QT interval, hypokalemia were excluded. All patients received one dose of 0.3 mg/kg of nifekalant over 10 minutes under continuous ambulatory monitoring. Four patients with common AFL in each group received nifekalant during electrophysiologic (EP) study.
Results:

Nifekalant had an overall AFL conversion efficacy of 77.4% within 60 minutes. Eleven patients in S‐AFL group (68.8%) and 13 patients in I‐AFL group (86.7%) could be converted with mean conversion times of 10.8 ± 6.2 and 15.0 ± 8.0 minutes, respectively (n.s.). Conversion rate was significantly higher in patients with a short duration of arrhythmia. The two modes of AFL termination were mainly demonstrated and the preferential mode significantly differed between the two groups. One patient in each group with excessive QT prolongation (6.5%) developed torsade de pointes (TdP), requiring electrical shock in one patient (3.3%).
Conclusions:

Nifekalant can be used for conversion of AFL with a potent efficacy even in patients with structural heart diseases. However, caution should be required for developing TdP.
Predictors of Cardiac Arrest Occurring in the Context of Acute Myocardial Infarction
Authors: HREYBE HAITHAM , SINGLA ISH , RAZAK EATHAR , SABA SAMIR 
Published: September 2007

Background:Cardiac arrest (CA) concurrent with acute myocardial infarction (AMI) claims the life of many patients with coronary artery disease (CAD). In this study, we investigated the predictors of CA during AMI.Method:Patients admitted with CA concurrent with AMI (n = 31) were matched by age, gender, race, and left ventricular ejection fraction (LVEF) to patients with AMI but no CA (n = 70). All patients underwent coronary angiography. Binary logistic regression was used to identify independent predictors of CA during AMI.Results:A total of 101 patients (age = 61 ± 13 years, men 76%, Caucasians 98%, LVEF 33 ± 12%) admitted to the University of Pittsburgh Medical Center with AMI were included in this analysis. Patients with CA concurrent with the AMI were more likely to have proximal rather than distal coronary artery culprit lesions (odds ratio (OR) = 7.2, P = 0.019). Other predictors of CA in the context of AMI included negative family history of CAD (OR = 8.0, P = 0.026) and absence of sinus rhythm upon hospital admission (OR = 5.1, P = 0.030).Conclusion:Proximity of culprit coronary lesion and presence of rhythm other than sinus rhythm at hospital admission are two strong predictors of CA in the context of AMI. The implication is that the mechanism of CA is primarily that of a large area of myocardial ischemia leading to lethal ventricular arrhythmia. Other predispositions such as genetic make‐up cannot be ruled out.
Relationship Between Abnormal Microvolt T‐Wave Alternans and Poor Glycemic Control in Type 2 Diabetic Patients
Authors: MOLON GIULIO , COSTA ALESSANDRO , BERTOLINI LORENZO , ZENARI LUCIANO , ARCARO GUIDO , BARBIERI ENRICO , TARGHER GIOVANNI 
Published: September 2007

Background:

Abnormal microvolt T‐wave alternans (TWA) predicts the risk of ventricular arrhythmias and sudden cardiac death. Although type 2 diabetes is associated with an increased risk of these events, there is a dearth of available data on microvolt TWA measurements in type 2 diabetic populations.
Methods:

We studied 59 consecutive type 2 diabetic outpatients without manifest cardiovascular disease (CVD) and 35 non‐diabetic controls who were matched for age, sex, and blood pressure values. Microvolt TWA analysis was performed non‐invasively using the CH‐2000 system during a sub‐maximal exercise with the patient sitting on a bicycle ergometer.
Results:

The frequency of abnormal TWA was significantly higher in diabetic patients than in controls (25.4 vs 5.7%; P < 0.01). Among diabetic patients, those with abnormal TWA (n = 15) had remarkably higher hemoglobin A1c (HbA1c) (8.1 ± 0.9 vs 7.1 ± 0.8%, P < 0.001) and slightly smaller time‐domain heart rate variability parameters (i.e., RMSSD, root mean square of difference of successive R‐R intervals) than those with normal TWA (n = 44). Gender, age, body mass index, lipids, blood pressure values, cigarette smoking, diabetes duration, microvascular complication status, QTc interval, and current use of medications did not significantly differ between the groups. In multivariate regression logistic analysis, HbA1c (OR 13.6, 95% CI 2.0–89.1; P = 0.0076) predicted abnormal TWA independent of RMSSD values and other potential confounders.
Conclusions:

Our findings suggest that abnormal TWA is a very common condition (∼25%) among people with type 2 diabetes without manifest CVD and is closely correlated to glycemic control.
Hemodialysis in the United Kingdom
Authors: MACGREGOR Mark S. , CARR Sue J. 
Published: September 2007

AbstractHemodialysis was a neglected aspect of nephrology in the UK. At the request of the Renal Association, the first UK Haemodialysis Masterclass was organized in 2007. The articles in this supplement arose from that meeting. Here, an overview of UK hemodialysis services and nephrology training is presented as background. Government‐funded dialysis should be provided to all UK citizens who require it. In 2005, there were 17,645 patients receiving hemodialysis, 5057 on peritoneal dialysis and 19,074 with kidney transplants, looked after by 359 nephrologists working in 73 National Health Service renal units. Renal replacement therapy incidence and prevalence remain comparatively low, at 108 and 694 per million population, respectively. Whether this represents inadequate provision or genuinely lower need remains unclear. The Renal Association sets clinical practice guidelines for dialysis, and audits performance via the UK Renal Registry. Postgraduate medical education is undergoing radical change in the UK. This is driven by the reduction in trainee doctors' working hours to 48 hr/week (mandated by the European Working Time Directive), and the governments' wish to reduce the duration of training, but also by a desire to formalize training, Our challenge is to continue to produce talented clinical nephrologists educated in breadth and depth, despite the reduced emphasis on clinical experience and omission of period of scientific research. The future for hemodialysis services in the UK is, however, promising with an expansion in the number of specialists and dialysis centers, and a growing interest in dialysis practice and research.
Alternatives to standard hemodialysis
Authors: MACGREGOR Mark S. 
Published: September 2007

AbstractSurvival of patients on hemodialysis remains poor, but the benefits of increasing urea clearance have probably been maximized within our current treatment schedules. Long dialysis sessions (8 hr) produce impressive outcomes, with mortality 53% to 55% lower than conventional schedules. Even increasing from 4 to 5 hr may improve survival. Increased frequency of dialysis (6 times weekly) produces impressive reductions in left ventricular mass and could conceivably be implemented in‐center. Preliminary data suggest a 61% reduction in mortality with increased frequency. Nightly dialysis combines longer sessions with increased frequency and has produced remarkable clinical gains in blood pressure, left ventricular mass, serum phosphate, and sleep apnea. However, the data are mainly from case series and impact on mortality remains unknown. Expansion of home hemodialysis would be necessary for this modality to grow. Convective therapies remove middle molecules more effectively, and observational data suggest hemodiafiltration has the potential to improve mortality by 35% to 36%. Hemodiafiltration has the advantage of being relatively easy to implement. The uremic milieu is complex and further investigation of the underlying pathophysiology is needed to inform future dialysis interventions. The survival data above are from observational studies, and hence benefits are likely to be exaggerated. Randomized trials of dialysis interventions are desperately needed. They remain difficult to perform, because of the complexity of both the patient population and the interventions, and because of limited available funding.
Dialysis desiderata*
Authors: WINCHESTER James F. , AMERLING Richard , DUBROW Alan , FEINFELD Donald A. , GRUBER Stephen J. , HARBORD Nikolas , KUNTSEVICH Viktoriya 
Published: September 2007

AbstractMicroarray immunoassay systems, proteomics, separation of polypeptides in plasma by electrophoresis, and detection by mass spectrometry have shown that low molecular weight proteins, cytokines, and chemokines are present in high concentration in chronic kidney disease (CKD) subjects receiving dialysis. That these substances are also found in high concentration in sepsis, postcardiac bypass, acute respiratory distress, burns, and in brain death suggest that these syndromes have a common pathogenesis via a systemic inflammatory response syndrome (SIRS). It is not yet clear whether the profiles of such substances differ among the SIRS states. Dialysis membranes are not capable of removing these substances because such moieties exceed the molecular weight cutoff of modern synthetic hemodialysis membranes. On the other hand, sorbents directly in contact with blood or indirectly with filtered plasma, may be designed with pore structures with the capability of removing these substances. Such sorbents could be exploited in the treatment of CKD. While few human studies have been performed, animal experiments suggest that human trials should be initiated. The potential advantages of sorbents for CKD will be described.