bluuebunny/crossref_metadata_2025_split huggingface dataset:
Clinical Applicability of Transient Evoked Otoacoustic Emissions: Identification and Classification of Hearing Loss
Authors: Hatzopoulos S. , Prosser S. , Mazzoli M. , Rosignoli M. , Martini A. 
Published: April 2003

The study aimed at the development of a clinically applicable methodology that could: (1) discriminate transient evoked otoacoustic emission (TEOAE) recordings from normal hearing or hearing impaired individuals; (2) classify the nature of the hearing loss as conductive or as cochlear, and (3) define clear-cut TEOAE clinical criteria. A classification algorithm based on a multivariate discriminant analysis of fast Fourier transform data from recordings evoked by click stimuli of 50 ± 2, 62 ± 2, 68 ± 2 and 80 ± 2 dB SPL was used to discriminate 302 normal subjects from 383 subjects suffering from mild to moderate hearing losses. The best discriminant model (QDF80) produced a sensitivity of 93.8% and a specificity of 79.4%. When extra correlation criteria were serially applied to the classification outcome, the specificity was increased to 85.3%, but the sensitivity was marginally decreased to 91.7%. The classification of the correctly identified hearing-impaired cases yielded 93.8% identification of conductive and 75.1% identification of cochlear cases. A sensitivity analysis of the misclassified hearing-impaired cases suggested that the TEOAE spectra are well correlated with the 2-kHz but poorly correlated with the 4-kHz octave frequency.
Trained Discrimination of Temporal Patterns: Cochlear Implants in Gerbils
Authors: Kadner Alexander , Scheich Henning 
Published: April 2003

The purpose of this study was to establish an animal model for the discrimination of temporal order cues contained in electrical stimuli to the cochlea. Gerbils were deafened and implanted in the right cochlea with a single platinum stimulating electrode. Two groups of animals were trained in a two-way active avoidance shuttle box paradigm to discriminate downward from upward interval-modulated pulse trains (1–100 ms). One group consisted of naive animals. The other group had previously been trained in the same shuttle box (same behavioral meaning) to discriminate identical pulse trains presented acoustically. Significant discrimination performance was found in the group of naive animals. However, over the 6-day training period, animals with previous acoustic experience achieved no significant discrimination performance. This suggests that temporal order cues in pulse trains can be used in cochlear implants to transmit behaviorally relevant information but that this may be in conflict with relevant auditory preexperience.
Cardiac Function and Oxygen Balance in Septic Patients during Continuous Hemofiltration
Authors: Meloni Carlo , Morosetti Massimo , Turani Franco , Palombo Giuditta , Meschini Luciano , Zupancich Enrico , Taccone-Gallucci Massimo , Di Giulio Salvatore , Casciani Carlo U. 
Published: April 2003

The aim of this work was to study hemodynamic, oximetric and metabolic parameters in septic patients during continuous hemofiltration, in order to determine whether the changes in hemodynamic parameters can influence the oxygen utilization in peripheral tissues. 29 multiple organ failure patients with septic shock were studied during the first 48 h of continuous hemofiltration: 18 were submitted to CAVH and 11 patients were treated with CAVHD to correct ARF and fluid overload. Our data show that RVEF improves and REDVI reduces progressively during treatment, together with a significant reduction of the cardiac index after 48 h of CAVH(D). There were no significant variations in oxygen tissue parameters, while plasma lactate was reduced significantly. In conclusion, our data confirm that continuous hemofiltration may be useful in septic patients to correct fluid overload and ARF, without affecting hemodynamic stability and oxygen balance. Moreover, in septic patients, this technique improves hemodynamics, reduces the filling pressure in the right heart and reduces hyperdynamic response as CI and SVRI, without any negative effects on O<sub>2</sub> balance.
Effects of Hemodialysis on Circulating Adrenomedullin Concentrations in Patients with End-Stage Renal Disease
Authors: Toepfer M. , Schlosshauer M. , Sitter T. , Burchardi C. , Behr T. , Schiffl H. 
Published: April 2003

To characterize the determinants of circulating levels of adrenomedullin (AM), the plasma levels of this peptide were measured in 58 patients with end-stage renal disease on hemodialysis. Predialysis plasma levels of AM were more than twice as high in patients on hemodialysis as compared to controls. In hemodialysis patients with heart failure (NYHA classes II–IV) or hypertensive HD patients plasma levels of AM were significantly higher than in patients with end-stage renal disease only. Plasma levels of AM were not altered immediately by hemodialysis but decreased significantly 14–20 h after hemodialysis. AM plasma levels before hemodialysis and 14–20 h after hemodialysis were correlated with the corresponding mean arterial pressure.
Analysis of Urea Nitrogen and Creatinine Kinetics in Hemodialysis: Comparison of a Variable-Volume Two-Compartment Model with a Regional Blood Flow Model and Investigation of an Appropriate Solute Kinetics Model for Clinical Application
Authors: Yamada Toshio , Hiraga Seigo , Akiba Takashi , Marumo Fumiaki 
Published: April 2003

To investigate an appropriate solute kinetics model for clinical application, we analyzed urea nitrogen (UN) and creatinine (Cr) kinetics by a variable-volume two-compartmental model (2CM) and a regional blood flow model (RBF) in 44 hemodialysis patients with varying proportions of first compartmental volume and regional volume (p<sub>1</sub>). Solute kinetics could not be solved in some of the patients with higher p<sub>1</sub> values, and there were more solution failures by the RBF than by the 2CM. The solute generation rate (g) and solute distribution volume in the dry state (V<sub>D</sub>) increased with increases in p<sub>1</sub> in both models, but there were some differences between the two models. When g was normalized by V<sub>D</sub>, it became relatively constant, irrespective of the p<sub>1</sub> value or model used (0.133 ± 0.029 mg/min/l by the 2CM and 0.132 ± 0.029 mg/min/l by the RBF for UN; 0.0200 ± 0.0049 mg/min/l by the 2CM and 0.0198 ± 0.0048 mg/min/l by the RBF for Cr). The intercompartmental mass transfer coefficient (K<sub>c</sub>; liters/min) calculated by the 2CM decreased as p<sub>1</sub> increased (K<sub>c</sub> = –1.77·p<sub>1</sub> + 1.16, p < 0.0001, R = 0.999 for UN; K<sub>c</sub> = –0.847·p<sub>1</sub> + 0.556, p < 0.0001, R = 1.000 for Cr). The systemic blood flow (Q<sub>sys</sub>; liters/min) calculated by the RBF also decreased as p<sub>1</sub> increased (Q<sub>sys</sub> = –11.1·p<sub>1</sub> + 6.21, p < 0.0005, R = 1.000 for UN; Q<sub>sys</sub> = –5.22·p<sub>1</sub> + 2.90, p < 0.001, R = 0.999 for Cr). Since the RBF more frequently failed to solve the solute kinetics and since there was a difference in its Q<sub>sys</sub> values for UN and Cr, the 2CM was considered to be a superior model. When p<sub>1</sub> was extremely low, the 2CM could be transformed into a modified variable-volume one-compartment model (1CM) which presented a similar g/V<sub>D</sub> (0.133 ± 0.029 for UN; 0.0200 ± 0.0048 for Cr). This modified 1CM was considered to satisfy appropriate conditions for clinical application, since it is simpler than the 2CM and provides useful information on the dialysis dose.
Diffusion Kinetics in Blood during Haemodialysis and in vivo Clearance of Inorganic Phosphate
Authors: Descombes Eric , Jutzet André , Perriard François , Fellay Gilbert 
Published: April 2003

Contradictory data are reported in the literature concerning the diffusion kinetics of inorganic phosphates (iPh) between red blood cells and plasma during haemodialysis. Accordingly, we performed mass balance and equilibration studies to analyze the diffusion kinetics of iPh in vivo and in vitro. Mass balance analysis shows that iPh is only cleared from the plasma volume and thus that it practically does not diffuse from red blood cells to plasma during the short time lapse of blood transit through the haemodialyzer. In vitro equilibration studies of blood drawn at the filter outlet show that at room temperature there is a slow, limited, and almost linear net efflux of iPh during the 4 h that follow blood drawing. Our results point out: (1) that the in vivo clearance of iPh should be exclusively determined as plasma clearance, and (2) that for accurate clearance determinations the iPh concentrations should be measured in blood samples centrifuged within at most 1 h after blood drawing. Whole-blood clearance determinations – as well as the in vitro dialyzer data – largely overestimate (>30%) the real in vivo dialyzer performance.
Experience with Diffusion-Weighted Imaging in an Acute Stroke Unit
Authors: Read S.J. , Jackson G.D. , Abbott D.F. , Syngeniotis A. , Mitchell L.A. , Fitt G.R. , Donnan G.A. 
Published: April 2003

We performed diffusion-weighted MRI (DWI) on a standard 1.5-tesla MRI scanner using a high-speed stimulated echo pulse sequence (turboSTEAM) in 9 stroke patients and 9 control subjects to investigate whether this technique can be used clinically to assist in ischaemic stroke diagnosis within the time frame for potential therapy. Stroke patients underwent DWI between 3.75 h and 3 days after stroke onset. Three patients were studied on more than one occasion. DWI was normal in the 9 controls. Seven of 9 stroke patients showed areas of increased signal on DWI. DWI detected cerebral ischaemia 3.75 h after stroke onset when both CT and T2-weighted MRI were normal. In 6 DWI-positive patients studied at later times, increased signal on T2-weighted images was present at the same time. Two patients had normal CT, T2-weighted and DWI images; both made good neurological recoveries. For the routine assessment of stroke patients, DWI implemented on a standard MRI system can provide additional information of clinical value to that obtained with conventional pulse sequences. In particular it facilitates early detection of cerebral ischaemia during the first few hours after stroke.
The ECASS 3-Hour Cohort
Authors: Steiner Thorsten , Bluhmki Erich , Kaste Markku , Toni Danilo , Trouillas Paul , von Kummer Rüdiger , Hacke Werner 
Published: April 2003

<b>Objectives:</b> (1) To determine whether and how outcome measurements in the ECASS trial are influenced by a shorter time window (0–3 vs. 3–6 h) between onset of symptoms and start of thrombolytic therapy using recombinant tissue plasminogen activator (rt-PA) in acute ischemic stroke. (2) To discuss the results of the ECASS 0- to 3-hour cohort with the results of the National Institute of Neurological Disorders and Stroke Study (NINDSS). <b>Design and Analysis:</b> Analysis of the 0- to 3-hour and the 3- to 6-hour cohort in accordance with the ECASS protocol. Comparative analysis of the ECASS and NINDSS results following the NINDSS protocol using dichotomized endpoints. <b>Main Outcome Measures:</b> Primary endpoints: modified Rankin Scale, Barthel Index; secondary endpoints: combined Barthel/Rankin, long-term Scandinavian Stroke Scale, National Institutes of Health Stroke Scale, mortality at 30 and 90 days, occurrence of intracranial hemorrhage. NINDS trial endpoint: favorable outcome as defined in the NINDS trial. <b>Results:</b> In ECASS, 87 patients were randomized within 3 h of stroke onset. Differences in favor of rt-PA treatment can be found for all primary and secondary outcome measures in the ECASS 0- to 3-hour cohort, except for mortality at day 30, which is somewhat higher in the rt-pA-treated group. However, due to the small sample size, the differences do not reach statistical significance. Early infarct signs (as defined by the ECASS protocol) are found as early as 2 h after stroke onset. Parenchymal hemorrhages are found significantly more often among rt-PA-treated patients. The results in the ECASS 0- to 3-hour cohort fit well with the results in NINDSS. <b>Conclusion:</b> Data from the 3-hour ECASS cohort support the efficacy of early thrombolytic therapy in acute hemispheric stroke patients. Comparing bleeding complications between the ECASS and NINDSS is difficult because of differences in the definition and occurrence of hemorrhagic events.
Migraine with Aura and Right-to-Left Shunt on Transcranial Doppler: A Case-Control Study
Authors: Del Sette Massimo , Angeli Silvia , Leandri Massimo , Ferriero Giorgio , Bruzzone Gian Luca , Finocchi Cinzia , Gandolfo Carlo 
Published: April 2003

Right-to-left shunt (RLS), usually due to patent foramen ovale, is a well-established risk factor for ischemic stroke in young patients, while the role of migraine as an independent factor is still debated. We evaluated 44 patients suffering from migraine with aura, and compared them with 73 patients younger than 50 with focal cerebral ischemia, and 50 controls, asymptomatic for cerebrovascular disease, and without a history of migraine. All the subjects underwent bilateral transcranial Doppler with injection of contrast medium in an antecubital vein. The test was performed during normal ventilation and during Valsalva maneuver, recording both the middle cerebral arteries and the basilar artery. Criteria for diagnosing RLS was the presence of at least 3 microbubbles within 15 s from injection. Eighteen out of 44 migraine patients (41%) showed RLS, as opposed to 8 of 50 controls (16%) (p < 0.005). Twenty-six out of 73 patients with cerebral ischemia had RLS (35%). We conclude that the prevalence of RLS in patients with migraine with aura is significantly higher than in normal controls, and is similar to the prevalence of RLS in young patients with stroke. These findings could be helpful in understanding the relationship between migraine and stroke.
Neuroprotective Effects of Glycine for Therapy of Acute Ischaemic Stroke
Authors: Gusev E.I. , Skvortsova V.I. , Dambinova S.A. , Raevskiy K.S. , Alekseev A.A. , Bashkatova V.G. , Kovalenko A.V. , Kudrin V.S. , Yakovleva E.V. 
Published: April 2003

The aim of this randomized, double-blind, placebo-controlled trial was to assess the safety and the efficacy of the pharmaceutic drug glycine in 200 patients with acute (<6 h) ischaemic stroke in the carotid artery territory. Fifty patients received placebo, 49 glycine 0.5 g/day, 51 glycine 1.0 g/day and 50 glycine 2.0 g/day for 5 days in each group. The efficacy of glycine was assessed by clinical analysis, by an enzyme-linked immunosorbent assay of levels of blood serum autoantibodies to NMDA-binding proteines, by detection of excitatory (glutamate, aspartate) and inhibitory (glycine, GABA) amino acid concentrations and lipid peroxidation products (TBARS) in CSF. The trial confirmed the safety profile of the glycine treatment. Slight sedation was observed in 9 patients (4.5%) as a side-effect. Other marked side-effects or adverse events were absent. The glycine treatment at the dose of 1.0–2.0 g/day was accompanied by a tendency to a decreased 30-day mortality (5.9% in 1.0 g/day glycine and 10% in 2.0 g/day glycine groups vs. 14% in the placebo and 14.3% in 0.5 g/day glycine groups), to an improved clinical outcome on the Orgogozo Stroke Scale (p < 0.01) and the Scandinavian Stroke Scale (p < 0.01) and to a favourable functional outcome on the Barthel index (p < 0.01 in 1.0 g/day glycine vs. placebo group in patients with no or mild disability). An early normalization of autoantibody titres to NMDA-binding proteins in serum was found (p < 0.01 vs. placebo), a reduction of glutamate and aspartate levels (p < 0.05 vs. placebo), an increase in GABA concentrations (p < 0.01 vs. placebo in severe stroke patients) and also a reduction of TBARS levels (p < 0.05 vs. placebo) in CSF by day 3. Thus, the trial suggests that sublingual application of 1.0–2.0 g/day glycine started within 6 h after the onset of acute ischaemic stroke in the carotid artery territory is safe and can exert favourable clinical effects. These results will be verified in further trials with a larger number of patients.
Measurement of Cerebral Circulation Time by Contrast-Enhanced Doppler Sonography
Authors: Hoffmann Olaf , Weih Markus , Schreiber Stephan , Einhäupl Karl Max , Valdueza José Manuel 
Published: April 2003

We present a new, non-invasive ultrasound method for the measurement of cerebral circulation time. After injection of a galactose-based echo-contrast agent (Levovist) into an antecubital vein, cerebral circulation time is measured as the interval between the beginning of a stable signal enhancement of at least 5 dB in the internal carotid artery and in the ipsilateral internal jugular vein. Both vessels are insonated simultaneously at the mandibular angle using a single 2-MHz range-gated transducer. For this study, 25 healthy volunteers ranging in age from 23 to 55 years (30.1 ± 7.5 years; mean ± SD) were examined. Cerebral circulation time was 5.6 ± 1.7 s without significant side-to-side or sex-related differences. Measurement of circulation times offers a new possibility for the employment of echo-contrast agents in functional ultrasound.
Design of ESPRIT: An International Randomized Trial for Secondary Prevention after Non-Disabling Cerebral Ischaemia of Arterial Origin
Authors: De Schryver E.L.L.M. 
Published: April 2003

The ESPRIT trial addresses the problem that aspirin, the standard therapy for secondary prevention of vascular complications after a transient ischaemic attack (TIA) or ischaemic stroke of arterial origin, reduces the risk of serious vascular events by only about 13%. Anticoagulants may be an alternative, as these have proved highly efficacious in trials after myocardial infarction and after cerebral ischaemia with atrial fibrillation. After cerebral ischaemia of presumed arterial origin, high-intensity anticoagulation (INR 3.0–4.5) is not safe, but the value of anticoagulation with an INR between 2.0 and 3.0 is still unknown. Secondly, a recent, large trial showed that the combination of aspirin and dipyridamole prevents more major vascular events than aspirin alone, but several earlier trials did not find such an advantage. In ESPRIT, patients with a TIA or minor ischaemic stroke (Rankin grade ≤3) will be randomized between oral anticoagulation (INR 2.0–3.0), the combination of dipyridamole (400 mg daily) plus aspirin (in any dose between 30 and 325 mg daily) and aspirin only. Primary outcome is the composite event ‘death from all vascular causes, non-fatal stroke, non-fatal myocardial infarction or major bleeding complication’, whichever occurs first. Outcome assessment will be blinded. The recruitment of a total of 4,500 patients from more than 10 countries is planned; the mean follow-up will be 3 years.
Relationship between Cerebral Blood Flow and Clinical Outcome in Acute Stroke
Authors: Rubin Giorgio , Firlik Andrew D. , Levy Elad I. , Pindzola Ronda R. , Yonas Howard 
Published: April 2003

<i>Objective:</i> The purpose of this study was to determine the relationship between cerebral blood flow (CBF) measurements in acute stroke and early clinical outcome. <i>Material and Methods:</i> The xenon-enhanced computed tomography (XeCT) CBF studies performed in 50 patients in the acute stage (within 8 h) of a hemispheric stroke were retrospectively analyzed. The mean CBF of the symptomatic vascular territory was compared to the corresponding territory in the contralateral hemisphere. Clinical assessment on admission and discharge was performed using the National Institutes of Health stroke scale (NIHSS). <i>Results:</i> Three groups were defined according to the degree of CBF asymmetry between the symptomatic and the contralateral asymptomatic vascular region. The CBF asymmetry was mild in group A (≤20%), moderate in group B (>20% and <60%) and severe in group C (≥60%). Patients in group A (n = 18) had a good outcome with a mean NIHSS score of 2 ± 2 at discharge. In group B, the patients (n = 22) had intermediate but variable outcomes: 2 patients died and the mean NIHSS score for the survivors was variable (mean NIHSS score: 9 ± 6). The patients in group C (n = 10) had a very poor outcome: 4 patients died and the survivors had a mean NIHSS score of 15 ± 1. <i>Conclusions:</i> Quantitative XeCT CBF measurements may be useful for selecting subgroups of stroke patients with different clinical outcomes. The possibility of predicting patient prognosis as early as in the first hours after the ischemic event may help to identify the appropriate target population that will benefit from aggressive stroke therapy.
Epileptic Seizures Attributed to Cerebral Hyperperfusion after Percutaneous Transluminal Angioplasty and Stenting of the Internal Carotid Artery
Authors: Wah Ho David Sai , Wang Yan , Chui Michele , Ho Shu Leong , Fai Cheung Raymond Tak 
Published: April 2003

Cerebral hyperperfusion syndrome as a complication of carotid endarterectomy (CEA) has been widely reported in the surgical literature. It may occur within hours to 3 weeks after CEA and is characterized by symptoms ranging from headaches, fits, confusion, focal neurological signs to intracerebral hemorrhage. Although percutaneous transluminal angioplasty (PTA) and stenting are increasingly performed as an alternative to CEA in the treatment of carotid artery stenosis, few cases of cerebral hyperperfusion injury following carotid stenting have been reported. We describe 2 cases of cerebral hyperperfusion syndrome following PTA and stenting for high-grade internal carotid artery (ICA) stenosis. Both cases involved a lesion of 95% in severity. The first case was a 73-year-old man who developed generalized convulsion 7 h following stenting to the left ICA. The second case was an 80-year-old woman who developed recurrent right periorbital headache and confusion 16 h after stenting to the right ICA, followed by left upper limb seizure 14 days later. Both patients fully recovered without any intracerebral hemorrhage or infarction. To our knowledge, this is the first report of cerebral hyperperfusion injury after carotid stenting without associated intracranial hemorrhage and with full recovery. In the patient with neurological symptoms following carotid stenting, it is important to consider cerebral hyperperfusion syndrome as a differential diagnosis to embolic or hemorrhagic stroke since early recognition and meticulous control of blood pressure may prevent progression to cerebral hemorrhage and death.