bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development of a Pump Flow Estimator for Rotary Blood Pumps to Enhance Monitoring of Ventricular Function
Authors: Granegger Marcus , Moscato Francesco , Casas Fernando , Wieselthaler Georg , Schima Heinrich 
Published: August 2012

AbstractEstimation of instantaneous flow in rotary blood pumps (RBPs) is important for monitoring the interaction between heart and pump and eventually the ventricular function. Our group has reported an algorithm to derive ventricular contractility based on the maximum time derivative (dQ/dtmax as a substitute for ventricular dP/dtmax) and pulsatility of measured flow signals. However, in RBPs used clinically, flow is estimated with a bandwidth too low to determine dQ/dtmax in the case of improving heart function. The aim of this study was to develop a flow estimator for a centrifugal pump with bandwidth sufficient to provide noninvasive cardiac diagnostics. The new estimator is based on both static and dynamic properties of the brushless DC motor. An in vitro setup was employed to identify the performance of pump and motor up to 20 Hz. The algorithm was validated using physiological ventricular and arterial pressure waveforms in a mock loop which simulated different contractilities (dP/dtmax 600 to 2300 mm Hg/s), pump speeds (2 to 4 krpm), and fluid viscosities (2 to 4 mPa·s). The mathematically estimated pump flow data were then compared to the datasets measured in the mock loop for different variable combinations (flow ranging from 2.5 to 7 L/min, pulsatility from 3.5 to 6 L/min, dQ/dtmax from 15 to 60 L/min/s). Transfer function analysis showed that the developed algorithm could estimate the flow waveform with a bandwidth up to 15 Hz (±2 dB). The mean difference between the estimated and measured average flows was +0.06 ± 0.31 L/min and for the flow pulsatilities −0.27 ± 0.2 L/min. Detection of dQ/dtmax was possible up to a dP/dtmax level of 2300 mm Hg/s. In conclusion, a flow estimator with sufficient frequency bandwidth and accuracy to allow determination of changes in ventricular contractility even in the case of improving heart function was developed.
Passive Control of a Biventricular Assist Device With Compliant Inflow Cannulae
Authors: Gregory Shaun David , Pearcy Mark John , Timms Daniel 
Published: August 2012

AbstractRotary ventricular assist device (VAD) support of the cardiovascular system is susceptible to suction events due to the limited preload sensitivity of these devices. This may be of particular concern with rotary biventricular support (BiVAD) where the native, flow balancing Starling response is diminished in both ventricles. The reliability of sensor and sensorless‐based control systems which aim to control VAD flow based on preload has limitations, and, thus, an alternative solution is desired. This study introduces a compliant inflow cannula (CIC) which could improve the preload sensitivity of a rotary VAD by passively altering VAD flow depending on preload. To evaluate the design, both the CIC and a standard rigid inflow cannula were inserted into a mock circulation loop to enable biventricular heart failure support using configurations of atrial and ventricular inflow, and arterial outflow cannulation. A range of left (LVAD) and right VAD (RVAD) rotational speeds were tested as well as step changes in systemic/pulmonary vascular resistance to alter relative preloads, with resulting flow rates recorded. Simulated suction events were observed, particularly at higher VAD speeds, during support with the rigid inflow cannula, while the CIC prevented suction events under all circumstances. The compliant section passively restricted its internal diameter as preload was reduced, which increased the VAD circuit resistance and thus reduced VAD flow. Therefore, a CIC could potentially be used as a passive control system to prevent suction events in rotary left, right, and biventricular support.
Intracranial EEG‐fMRI analysis of focal epileptiform discharges in humans
Authors: Cunningham Cameron B. J. , Goodyear Bradley G. , Badawy Radwa , Zaamout Fateh , Pittman Daniel J. , Beers Craig A. , Federico Paolo 
Published: August 2012

SummaryPurpose:  Combining intracranial electroencephalography (iEEG) with functional magnetic resonance imaging (fMRI) is of interest in epilepsy studies as it would allow the detection of much smaller interictal epileptiform discharges than can be recorded using scalp EEG‐fMRI. This may help elucidate the spatiotemporal mechanisms underlying the generation of interictal discharges. To our knowledge, iEEG‐fMRI has never been performed at 3 Tesla (3T) in humans. We report our findings relating to spike‐associated blood oxygen level–dependent (BOLD) signal changes in two subjects.Methods:  iEEG‐fMRI at 3T was performed in two subjects. Twelve channels of iEEG were recorded from subdural strips implanted on the left posterior temporal and middle frontal lobes in a 20‐year‐old female with bilateral periventricular gray matter heterotopia. Twenty channels of iEEG were recorded bilaterally from two subdural strips laid anterior–posterior along mesial temporal surfaces in a 29‐year‐old woman with bilateral temporal seizures and mild left amygdalar enlargement on MRI. Functional MRI (fMRI) statistical maps were generated and thresholded at p = 0.01.Key Findings:  No adverse events were noted. A total of 105 interictal discharges were recorded in the posterior middle temporal gyrus of Subject 1. In Subject 2, 478 discharges were recorded from both mesial temporal surfaces (n = 194 left, 284 right). The right and left discharges were modeled separately, as they were independent. Subject 1 showed spike‐associated BOLD signal increases in the left superior temporal region, left middle frontal gyrus, and right parietal lobe. BOLD decreases were seen in the right frontal and parietal lobes. In Subject 2, BOLD signal increases were seen in both mesial temporal lobes, which when left and right spikes were modeled independently, were greater on the side of the discharge. In addition, striking BOLD signal decreases were observed in the thalamus and posterior cingulate gyrus.Significance:  iEEG‐fMRI can be performed at 3T with low risk. Notably, runs of only 5 or 10 min of EEG‐fMRI were performed as part of our implementation protocol, yet a significant number of epileptiform discharges were recorded, allowing meaningful analyses. With these studies, we have shown that deactivation can be seen in individual subjects with focal epileptiform discharges. These preliminary observations suggest a novel mechanism through which focal interictal discharges may have widespread cortical and subcortical influences.
Genetic variation in dopaminergic activity is associated with the risk for psychiatric side effects of levetiracetam
Authors: Helmstaedter Christoph , Mihov Yoan , Toliat Mohammad R. , Thiele Holger , Nuernberg Peter , Schoch Susanne , Surges Rainer , Elger Christian E. , Kunz Wolfram S. , Hurlemann René 
Published: August 2012

SummaryPurpose:  Levetiracetam (LEV) is a highly effective antiepileptic agent. A clinically relevant psychiatric complication of LEV treatment, however, is the provocation of irritability and aggression. Recent behavioral research indicates that personality traits may predispose to these side effects. To assess the genetic basis of the adverse psychotropic profile of LEV, a candidate gene‐based two‐stage association study was conducted.Methods:  Polymorphisms were a priori selected according to their relevance for impulsivity and reactive‐impulsive aggression. Based on data from both stages, a Bonferroni‐corrected joint meta‐analysis was computed.Key Findings:  Stage 1 analysis included 290 patients with epilepsy and revealed a higher load of adverse psychotropic side effects of LEV in patients carrying genetic variants associated with decreased dopaminergic activity: rs1611115 (dopamine‐β‐hydroxylase, DBH), rs4680 (catechol‐O‐methyltransferase, COMT), and rs1800497 (dopamine receptor D2‐associated ANKK1 TAQ‐1A). Stage II analysis including 100 patients with epilepsy, and joint meta‐analysis confirmed the effect of the rs1800497 polymorphism (Bonferroni corrected significance of the joint meta‐analysis, p = 0.0096).Significance:  Confirming the suggestion from behavioral observations that patients might be predisposed to develop irritation and aggression under treatment with LEV, the findings provide first evidence of an association of genetic variation in dopaminergic activity and the risk for psychiatric complications of LEV treatment. Replication and further work is required to prove a true causal relationship. Overall, the pharmacogenomic approach to behavioral side effects may provide a future tool to predict adverse psychotropic effects related to antiepileptic drugs.
Diagnosing Delirium in Older Hospitalized Adults with Dementia: Adapting the Confusion Assessment Method to International Classification of Diseases, Tenth Revision, Diagnostic Criteria
Authors: Thomas Christine , Kreisel Stefan H. , Oster Peter , Driessen Martin , Arolt Volker , Inouye Sharon K. 
Published: August 2012

ObjectivesTo compare performance characteristics of the Confusion Assessment Method (CAM) algorithm for screening and delirium diagnosis with criteria for delirium from the International Classification of Diseases, Tenth Revision (ICD‐10) and Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM‐IV) in high‐risk individuals.DesignProspective cohort study.SettingAcademic geriatric hospital.ParticipantsOne hundred two individuals aged 80 to 100 hospitalized for acute medical illness.MeasurementsComplete CAM instrument (nine items), scored using the four‐item CAM diagnostic algorithm. Criterion standard classification of delirium was rated independently according to expert consensus based on DSM‐IV and ICD‐10 criteria for delirium.ResultsIn 79 hospitalized participants, the CAM performed well for delirium screening (delirium prevalence of 24% according to DSM‐IV and 14% according to ICD‐10). Of all CAM features, acute onset and fluctuating course are most important for diagnosis (area under the receiver operating characteristic curve (AUC) = 0.92 in DSM‐IV and 0.83 in ICD‐10). The CAM diagnostic algorithm had a sensitivity of 0.74, a specificity of 1.0, and an AUC of 0.88 compared with the DSM‐IV reference standard and a sensitivity of 0.82, a specificity of 0.91, and an AUC of 0.85 compared with the ICD‐10. Compared with the ICD‐10, adding psychomotor change to the CAM algorithm improved specificity to 97%, but sensitivity fell to 55% (AUC = 0.96). Applying psychomotor change sequentially only to the group that the CAM algorithm identified as having no delirium improved sensitivity to 91% with specificity of 85% (AUC = 0.95).ConclusionAlthough the CAM diagnostic algorithm performed well against a DSM‐IV reference standard, adding psychomotor change to the CAM algorithm improved specificity and diagnostic value against ICD‐10 criteria overall in older adults with dementia and improved sensitivity and screening performance when applied sequentially in CAM‐negative individuals.
A Study of Elderly Adults Taking Warfarin Admitted with Prolonged International Normalized Ratio: A Community Hospital's Experience
Authors: Bergman Michael , Ori Yaacov , Blumberger Naava , Brener Zachary Z. , Salman Hertzel 
Published: August 2012

ObjectivesTo assess bleeding complications and outcome of individuals receiving oral anticoagulants who were admitted to the hospital with an international normalized ratio (INR) greater than 4 by comparing them according to age (≤80, >80).DesignRetrospective cohort study.SettingCommunity hospital.ParticipantsAll individuals (N = 253) admitted to the Department of Internal Medicine over a period of 4 years with an INR greater than 4: Group I, aged 80 and younger (n = 127); Group II, older than 80 (n = 126). Data included bleeding complications, survival, and quality of INR control before admission and up to 48 months after admission.ResultsAtrial fibrillation was the most common indication for warfarin therapy. Its incidence was higher in the older group (88% vs 73%, P = .004). More elderly participants lived in nursing homes (23% vs 9.4%. P = .004) or received in‐home assistance (38.9% vs 20.5%, P = .002). There was no difference in INR upon admission, duration of warfarin treatment, or frequency of INR tests before admission. The incidence of bleeding events was 18.1% in Group I and 12.7% in Group II (P = .30). Major bleeding events occurred in 1.6% of Group I and none of Group II (P = .50). During follow‐up after the first admission, the incidence of INR greater than 4 was higher in Group II (87.3% vs 70%, P = .02), without a difference in the number of additional admissions or bleeding events.ConclusionPrimary care physicians can safely maintain warfarin treatment in elderly adults, even in those with a history of hospitalization for high INR, using frequent INR measurements.
The Value of the Metabolic Syndrome Concept in Elderly Adults: Is It Worth Less Than the Sum of Its Parts?
Authors: Samaras Katherine , Crawford John , Baune Bernard T. , Campbell Lesley V. , Smith Evelyn , Lux Ora , Brodaty Henry , Trollor Julian N. , Sachdev Perminder 
Published: August 2012

ObjectivesTo determine whether the metabolic syndrome (MetS) or its components were more closely associated with disease states and inflammation in elderly adults.DesignSydney Memory and Ageing Study. Cross‐sectional, observational cohort.SettingPopulation‐derived, community‐dwelling elderly adults.ParticipantsNine hundred thirty individuals aged 70 to 90.MeasurementsAge‐ and sex‐adjusted odds ratios (ORs) for disease states; fasting circulating inflammatory markers and oxidative metabolism byproducts.ResultsMetS was associated with diabetes mellitus (OR = 4.1, P < .001) and bowel cancer (OR = 9.1, P = .03) but not in analyses that controlled for component conditions. Models containing component conditions had the strongest associations with heart disease. Disease associations were improved after addition of component conditions to the MetS model. The reverse did not hold: disease associations were not improved when MetS was added to the components model. Low high‐density lipoprotein cholesterol (HDL‐C) was independently associated with myocardial infarction (OR = 2.32) and angina pectoris (OR = 2.59) (both P < .008). Waist circumference was independently associated with cancer (OR = 1.82, P = .008). Although MetS was associated with higher C‐reactive protein, vascular cell adhesion molecule, interleukin‐6, amyloid A, homocysteine, and malondialdehyde, it explained less than half of the variance of models containing its components.ConclusionThe observation that MetS is associated with disease states and markers of circulating inflammation in the elderly is explained mainly by abdominal obesity and low HDL‐C. Longitudinal data will further clarify these cross‐sectional findings that MetS appears to be less than the sum of its parts in elderly adults.
A Randomized, Prospective Study of Efficacy and Safety of Oral Tramadol in the Management of Post‐Herpetic Neuralgia in Patients from North India
Authors: Saxena Ashok K. , Nasare Namita , Jain Smita , Dhakate Gaurav , Ahmed Rafat S. , Bhattacharya Sambit N. , Mediratta Pramod K. , Banerjee Basu D. 
Published: August 2012

AbstractObjective:  To evaluate the safety and efficacy of oral tramadol therapy (50 to 200 mg/day) in the treatment for post‐herpetic neuralgia (PHN).Methods:  The study was a prospective, single‐blind, non‐responder vs. responder, randomized trial conducted in 100 outpatients of PHN after oral administration of tramadol for 4 weeks. Those patients who had achieved 50% or greater pain relief after 14 days of oral tramadol treatment were categorized as responders and those reporting < 50% pain relief were categorized as non‐responders. Rescue analgesia was provided by the topical application of a cream consisting of the combination of 3.33% doxepin and 0.05% capsaicin to the affected areas of PHN patients of both groups for at least 14 days, along with tramadol therapy. The rescue analgesia was extended to 4 weeks in patients of the non‐responder group. The primary endpoints were measured using a Numerical Rating Scale (NRS) at rest and with movement. Secondary endpoints included additional pain ratings such as global perceived effect (GPE), Neuropathic Pain Symptom Inventory scores (NPSI), daily sleep interference score (DSIS), Quality of life (QOL) as per WHO QOL‐BREF Questionnaire scores, patient and clinician ratings of global improvement. The 2 groups were compared on the basis of pain intensity scores, encompassing primary as well as secondary endpoints, and QOL after 28 days of the treatment regimen.Results:  Pain intensity scores measured by NRS (at resting and with movement), NPSI, and DSIS were consistently reduced (P < 0.001) over 28 days at varying intervals in both the groups, but the magnitude of reduction was higher in responders than non‐responders. A concomitant improvement (P < 0.001) was observed in GPE on days 3, 14, and 28 as compared to the respective baseline scores in both the groups. Although the WHO QOL‐BREF scores showed significant (P < 0.001) improvement in QOL of PHN patients at days 14 and 28 in both the groups, the magnitude of improvement was higher in responders as compared to non‐responders. Significant improvement in pain intensity scores and QOL in non‐responders is mainly attributed to the use of rescue analgesia for 28 days rather than recommended tramadol therapy.Conclusions:  Treatment with tramadol 50 to 200 mg per day was associated with significant pain reduction in terms of enhanced pain relief, reduced sleep interference, greater global improvement, diminished side‐effect profile, and improved QOL in PHN patients from North India. Further categorization of PHN patients may be helpful so that additional or alternative therapy may be prescribed to non‐responders.
The efficacy of the use of intravenous human immunoglobulin in Brazilian newborns with rhesus hemolytic disease: a randomized double‐blind trial
Authors: Santos Maria Cristina , Sá Cynthia , Gomes Jr Saint Clair , Camacho Luiz Antonio , Moreira Maria Elisabeth 
Published: August 2012

BACKGROUND: The purpose of this study was to evaluate the efficacy of intravenous human immunoglobulin (IVIG) in the presence of high‐intensity phototherapy in decreasing the need for exchange transfusion in newborns with rhesus hemolytic disease.STUDY DESIGN AND METHODS: We performed a randomized, double‐blind, placebo‐controlled trial. The trial included D+ newborns born at 32 weeks of gestational age or later with a positive direct antiglobulin test and whose mothers were Rh‐alloimmunized and did or did not receive intrauterine transfusion. The newborns were randomly assigned to receive either IVIG at a dose of 500 mg/kg or placebo (saline solution, 10 mL/kg) during the first 6 hours of life. The primary outcome was the need for exchange transfusion. The criteria for exchange transfusion were total serum bilirubin (TSB) level at or above 340 µmol/L (20 mg/dL) or increasing by 8.5 µmol/L/hr (0.5 mg/dL/hr) despite intensive phototherapy.RESULTS: The trial included 92 newborns. There was no difference in the rate of exchange transfusion between groups: 6 of 46 (13%) in the IVIG group versus 7 of 46 (15.2%) in the placebo group (p = 0.765). There were no significant differences between groups with respect to their need for exchange transfusion, phototherapy time, peak bilirubin, or length of hospital stay. There were no adverse events related to the drug or the form of administration.CONCLUSION: Nonspecific human immunoglobulin was not effective in preventing the need for exchange transfusion in neonates with rhesus hemolytic disease.
Reduction of allogeneic red blood cell usage during cardiac surgery by an integrated intra‐ and postoperative blood salvage strategy: results of a randomized comparison
Authors: Weltert Luca , Nardella Saverio , Rondinelli Maria Beatrice , Pierelli Luca , De Paulis Ruggero 
Published: August 2012

BACKGROUND: The amount of allogeneic blood transfusion may relate to worse outcome in cardiac surgery. The reinfusion of red blood cells (RBCs) lost by patients, including those of chest drains, is a promising strategy to minimize allogeneic transfusions.STUDY DESIGN AND METHODS: To verify this hypotheis, 1047 cardiac surgery patients were randomly assigned to either traditional intraoperative blood salvage followed by chest drain insertion or intra‐ and postoperative strategy with the Haemonetics cardioPAT system. Allogeneic RBC transfusion rate (primary endpoint) and postoperative complications (secondary endpoint) were recorded at the time of discharge from the hospital and at first month follow‐up visit, respectively.RESULTS: The cardioPAT arm received 1.20 units of allogeneic RBCs per patient, whereas the control group required 2.11 units per patient, and this difference proved to be highly significant (p = 0.02). We observed a comparable 45‐day mortality rate but a lower rate of deep vein thrombosis (p = 0.04) and atrial fibrillation (p = 0.04) in the cardioPAT arm.DISCUSSION: A significant reduction in patient exposure to allogeneic RBCs was observed in the cardioPAT system arm. Complications were slightly less frequent in the cardioPAT group. The use of the cardioPAT is a safe and effective strategy to reduce allogeneic RBC transfusions in cardiac surgery.
Prevalence of serologic markers for hepatitis B and C viruses in Brazilian blood donors and incidence and residual risk of transfusion transmission of hepatitis C virus
Authors: de Almeida‐Neto Cesar , Sabino Ester Cerdeira , Liu Jing , Blatyta Paula Fraiman , Mendrone‐Junior Alfredo , Salles Nanci Alves , Leão Silvana Carneiro , Wright David J. , Basques Fernando Valadares , Ferreira João Eduardo , Busch Michael P. , Murphy Edward L. ,   NHLBI Retrovirus Epidemiology Donor Study‐II (REDS‐II), International Component
Published: August 2012

BACKGROUND: We evaluate the current prevalence of serologic markers for hepatitis B virus (HBV) and hepatitis C virus (HCV) in blood donors and estimated HCV incidence and residual transfusion‐transmitted risk at three large Brazilian blood centers.STUDY DESIGN AND METHODS: Data on whole blood and platelet donations were collected from January through December 2007, analyzed by center; donor type; age; sex; donation status; and serologic results for hepatitis B surface antigen (HBsAg), antibody to hepatitis B core antigen (anti‐HBc), and anti‐HCV. HBV and HCV prevalence rates were calculated for all first‐time donations. HCV incidence was derived including interdonation intervals that preceded first repeat donations given during the study, and HCV residual risk was estimated for transfusions derived from repeat donors.RESULTS: There were 307,354 donations in 2007. Overall prevalence of concordant HBsAg and anti‐HBc reactivity was 289 per 100,000 donations and of anti‐HCV confirmed reactivity 191 per 100,000 donations. There were significant associations between older age and hepatitis markers, especially for HCV. HCV incidence was 3.11 (95% confidence interval, 0.77‐7.03) per 100,000 person‐years, and residual risk of HCV window‐phase infections was estimated at 5.0 per million units transfused.CONCLUSION: Improvement in donor selection, socioeconomic conditions, and preventive measures, implemented over time, may have helped to decrease prevalence of HBV and HCV, relative to previous reports. Incidence and residual risk of HCV are also diminishing. Ongoing monitoring of HBV and HCV markers among Brazilian blood donors should help guide improved recruitment procedures, donor selection, laboratory screening, and counseling strategies.