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Biomedical subjects

L Kramer

Publications and source records attributed to L Kramer.

At least 73 records · Page 4Linked to original sources
PubMed2000

Improved outcome prediction in unconscious cardiac arrest survivors with sensory evoked potentials compared with clinical assessment.

OBJECTIVE: To compare the prognostic ability of sensory evoked potentials in cardiac arrest survivors with the outcome predicted by a panel of experienced emergency physicians based on detailed prehospital, clinical, and laboratory data. DESIGN: Inception cohort study. SETTING: Medical intensive care unit and department of emergency medicine at a university hospital. PATIENTS: A total of 162 unconscious, mechanically ventilated patients who survived > or =24 hrs after resuscitation from cardiac arrest. INTERVENTIONS: Recording of sensory evoked potentials and outcome prediction after review of detailed clinical and laboratory data by emergency physicians within 24 hrs after cardiac arrest. MEASUREMENTS AND MAIN RESULTS: At 6 months, the outcome of 36 patients was classified as favorable and 126 patients were rated as poor. After review of prehospital data, emergency physicians predicted favorable vs. poor outcome with a sensitivity of 70% and a specificity of 65%. After additional assessment of data 1 hr after cardiac arrest, the sensitivity of emergency physician predictions increased to 80%, whereas the specificity decreased to 48%. Outcome prediction by emergency physicians was most accurate after obtaining detailed patient data 24 hrs after cardiac arrest (sensitivity, 81%; specificity, 58%). In 35 of 36 patients with favorable outcomes, the cortical evoked potential N70 peak was detected between 72 and 128 msec. Of 113 patients with an N70 peak latency >130 msec or an absent N70 peak, all except one had a poor outcome. By using a cutoff of 130 msec, the N70 peak latency alone had a sensitivity of 94% and a specificity of 97%. The predictive accuracy of the N70 peak latency was significantly higher than the clinical assessment 24 hrs after cardiac arrest (91% vs. 76%, p = .0003). CONCLUSION: In unconscious cardiac arrest survivors, a recording of long-latency sensory evoked potentials is more accurate in predicting individual outcome than an emergency physician review of clinical data.

Analysis of Variance↗
PubMed2000

Metabolic encephalopathy in critically ill patients suffering from septic or nonseptic multiple organ failure.

OBJECTIVE: Evaluation of changes in the peak latencies of sensory evoked potentials in different patient groups, to evaluate differences in metabolic encephalopathy of critically ill patients with multiple organ failure as a result of septic or nonseptic conditions. DESIGN: Prospective cohort study. SETTING: Intensive care units of the university hospital, Vienna. PATIENTS: Patients (n = 103) treated on an intensive care unit because of multiple organ failure with additional metabolic encephalopathy. Multiple organ failure was induced by sepsis (group A; n = 56), surgery (group B; n = 29), or both (group C; n = 18). INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Metabolic encephalopathy was determined by measuring median nerve-stimulated short-latency and long-latency sensory evoked potentials. No differences in the peak latencies of the sensory evoked potentials were detected among the groups. Septic patients had a N70 peak latency of 131+/-21 msecs, nonseptic postsurgical patients of 132+/-17 msecs, and septic postsurgical patients of 134+/-17 msecs. The cervicomedullary N13 to cortical N20 conduction times were 6.4+/-1 msec, 6.4+/-1.4 msecs, and 6.8+/-1.2 msecs, respectively. All measured peak latencies were significantly prolonged compared with peak latencies of healthy controls. The severity of illness assessed by the Acute Physiology and Chronic Health Evaluation III score was not different between the three groups. An increase of the delay of N70 peak latencies was significantly correlated with the severity of illness (r2 = .15; p < .00005). CONCLUSION: There was no difference in sensory evoked potential measurements detectable among septic patients with multiple organ failure, nonseptic postsurgical patients with multiple organ failure, and septic postsurgical patients with multiple organ failure. The N70 peak latency was significantly correlated with the severity of illness but not with the presence or absence of sepsis. In postsurgical patients with multiple organ failure and superimposed sepsis, the N70 peak latencies were not further prolonged compared with postsurgical patients without sepsis.

Adult↗
PubMed2000

Insights into brain function and neural plasticity using magnetic source imaging.

This review outlines the rationale for the use of magnetoencephalography (MEG) or magnetic source imaging (MSI), a noninvasive functional imaging technique, and the features that any imaging method should display to make a substantial contribution to cognitive neuroscience. After a brief discussion of the basic experimental approach used in the authors' studies, the use of early sensory components of brain magnetic responses is reviewed to address issues of the functional organization of the primary sensory cortices, followed by a comment on the clinical use of these components. Second, normative studies focusing on the late components of magnetic responses for establishing the validity and reliability of MSI maps of the language-specific cortex in normal subjects are reviewed. Third, the authors' investigations of fine spatiotemporal features of brain activation maps, specific to receptive language and to reading, are reviewed. Fourth, experience with presurgical mapping of the language-specific cortex in neurosurgery candidates and in patients undergoing the "Wada" procedure is summarized followed by a comment on the perfect agreement of the MSI maps with those derived by more direct invasive brain mapping procedures. Fifth. MSI-derived evidence of often dramatic, functional reorganization of brain areas subserving both simple sensory and linguistic functions is summarized along with comments on the use of MSI as a means for investigating brain plasticity. Finally, in the sixth section of this review, the authors relate their experience with the use of MSI in deriving brain activation profiles during silent reading of real words and pseudowords that are specific to dyslexic children. The review concludes with a discussion on the further use of MSI in assessing, among other issues, the effectiveness of intervention strategies designed to improve reading fluency in dyslexic children.

Acoustic Stimulation↗
PubMed2000

Short-term prognosis in critically ill patients with liver cirrhosis: an evaluation of a new scoring system.

OBJECTIVE: The mortality of patients with liver cirrhosis admitted to an intensive care unit (ICU) has been found to be high. This study was performed to assess the physiological and laboratory parameters which are able to identify on ICU admission the cirrhotic patients who are most likely to die. DESIGN: Prospective clinical trial. METHODS: Two groups of patients were analysed. Group A consisted of 196 consecutive cirrhotic patients admitted to our medical ICU for various reasons. For the detection of independent outcome predictors, we used a multiple logistic regression model. Based on these variables, the 'intensive care cirrhosis outcome (ICCO) score' was calculated. The ability to discriminate between survivors and non-survivors was determined by receiver operating characteristic curves, and the area under the curve was calculated. Group B consisted of 70 consecutive cirrhotic patients for prospective validation of the ICCO score. RESULTS: Applying multiple logistic regression analysis, bilirubin, cholesterol, creatinine clearance and lactate were found to be independently associated with the hospital mortality. The ICCO score was 0.3707 + (0.0773 x bilirubin (mg/dl)) - (0.00849 x cholesterol (mg/dl)) -(0.0155 x creatinine clearance (ml/min)) + (0.1351 x lactate (mmol/l)), giving an area under a receiver operating characteristic curve of 0.9. Increasing score values were associated with an increase in mortality. All patients with an ICCO score > +2.6 died. CONCLUSIONS: Application of the ICCO score is rapid and available at the patient's bedside, and its application is simple and reproducible. In cirrhotic patients, the ICCO score has a high ability to discriminate between survivors and non-survivors. The ICCO score may facilitate estimation on ICU admission of the prognosis of critically ill cirrhotic patients.

Area Under Curve↗
PubMed2000

Abnormal rolls and regular arrays of disclinations in homeotropic electroconvection

We present the first quantitative verification of an amplitude description for systems with (nearly) spontaneously broken isotropy, in particular for the recently discovered abnormal-roll states. We also obtain a conclusive picture of the three-dimensional director configuration in a spatial period doubling phenomenon involving disclination loops. The first observation of two Lifshitz frequencies in electroconvection is reported.

Journal Article↗
PubMed2000

Domain segregation in a two-dimensional system in the presence of drift

Motivated by experiments on optical patterns we analyze two-dimensional extended bistable systems with drift after a quench above threshold. The evolution can be separated into successive stages: linear growth and diffusion, coarsening, and transport, leading finally to a quasi-one-dimensional kink-antikink state. The phenomenon is general and occurs when the bistability relates to uniform phases or two different patterns.

Journal Article↗
PubMed2000

Zigzag structures and domain walls in electroconvection of nematic liquid crystal

To describe the secondary-bifurcation scenario in ac-driven electroconvection of a planarly aligned nematic liquid crystal layer, we have constructed a generic phase equation coupled to the cinsertion mark director. The equations are applicable in particular in the vicinity of the codimension-2 point, where the zigzag and the abnormal roll instabilities meet. This point is also the origin of a line of homoclinic bifurcations, which separates a region where one has stationary zigzag walls from one with spontaneously accelerated abnormal roll walls. The final velocity of the walls depends linearly on the distance from the bifurcation. We analyze the scenario analytically, test it numerically and propose an experimental check.

Journal Article↗
PubMed2000

Oxcarbazepine placebo-controlled, dose-ranging trial in refractory partial epilepsy.

PURPOSE: The goal of the study was to evaluate the safety and efficacy of a broad oxcarbazepine (OXC) dosage range (600, 1200, and 2400 mg/d) as adjunctive therapy for uncontrolled partial seizures and to determine the relationship between trough plasma 10-monohydroxy derivative concentrations and OXC safety and efficacy. METHODS: This multinational, multicenter, randomized, 28-week, double-blind, placebo-controlled, four-arm, parallel-group trial enrolled 694 patients aged 15-65 years with uncontrolled partial seizures with or without secondarily generalized seizures. The primary efficacy variable was percentage change in seizure frequency per 28 days relative to baseline. RESULTS: The median reduction in seizure frequency was 26%, 40%, 50%, or 8% for patients receiving 600, 1200, or 2400 mg/d OXC or placebo, respectively (all p < or = 0.0001). Of patients in the 600, 1200, or 2400 mg/d OXC groups, 27%, 42%, and 50% respectively, had more than 50% reduction in seizure frequency compared with 13% for placebo (all p < 0.001). Higher plasma 10-monohydroxy derivative concentrations were associated with larger decreases in seizure frequency (p = 0.0001). During the double-blind treatment phase, 84%, 90%, 98%, and 76% of patients receiving 600, 1200, or 2400 mg/d OXC or placebo, respectively, reported one or more adverse events. The most common adverse events were related to the nervous and digestive systems. CONCLUSIONS: OXC is safe and effective as adjunctive therapy in patients with uncontrolled partial seizures. OXC 600 mg/d was the minimum effective dosage; effectiveness of OXC increased with dose. The rapid and fixed titration to high doses was associated with an increased risk of adverse events, which could potentially be reduced by adjusting concomitant antiepileptic medication and by using a slower, flexible OXC titration schedule.

Administration, Oral↗
PubMed1999

Heavy chronic alcohol abuse has no additional adverse effect on the function of extrahepatic organs and ICU mortality in patients with liver cirrhosis.

BACKGROUND AND AIMS: We questioned whether heavy chronic alcohol abuse influences extrahepatic organ failure and ICU mortality in cirrhotic patients admitted to a medical intensive care unit. PATIENTS AND METHODS: Medical records of 208 consecutive cirrhotic critically ill patients were reviewed. Patients were classified into two groups. Group A comprised 144 patients with liver cirrhosis due to heavy chronic alcohol abuse and group B, 64 patients with liver cirrhosis due to non-alcoholic causes. The presence of extrahepatic organ failures in patients of both groups was assessed with parameters determined on the day of admission to the ICU. Furthermore, ICU mortality was determined. RESULTS: The occurrence of extrahepatic organ failure was similar in group A and group B (83% vs. 80%; p = NS). The rate of extrahepatic organ failure was 1.7 +/- 1.2 organs in group A, compared to 1.4 +/- 1 organs in group B (p = NS). ICU mortality was 53% in group A and 44% in group B (p = NS). An increase in the number of extrahepatic organ failures was associated with a concomitant increase in ICU mortality in both groups of patients. CONCLUSION: The occurrence of extrahepatic organ failure and ICU mortality was not different between patients with liver cirrhosis secondary to heavy chronic alcohol abuse and patients with liver cirrhosis due to nonalcoholic causes. Cirrhotic patients should be admitted to a medical intensive care unit for extended intensive care treatment prior to the occurrence of extrahepatic multiple organ failure, independent of the underlying aetiology.

Adult↗
PubMed1999

Protein degradation and apoptotic death in lymphocytes during Fiv infection: activation of the ubiquitin-proteasome proteolytic system.

The movement of a cell through the sequential phases of apoptosis is accompanied by a progressive decrease in cell size with loss in protein mass. In lymphocytes from Hiv-infected persons, protein loss during apoptosis is due to increased protein degradation rather than decreased synthesis. To identify and characterize the proteolytic enzymes or enzyme systems involved in this process, we studied several features of protein turnover in lymphocytes from peripheral blood and lymph nodes during the natural and experimental infection by feline immunodeficiency virus (Fiv). This animal model allowed us to integrate in vivo results with in vitro observations of protein damage. Here we report that protein breakdown in apoptotic cells is concomitant with the activation of the ATP and ubiquitin-dependent multicatalytic system (proteasome). We suggest that proteasome activation is part of the proteolytic cascade in the execution phases of apoptosis in AIDS.

Animals↗
PubMed1999

Oxcarbazepine: double-blind, randomized, placebo-control, monotherapy trial for partial seizures.

OBJECTIVE: To evaluate the efficacy and safety of oxcarbazepine in a placebo-control trial. METHODS: A multicenter, double-blind, randomized, placebo-control, two-arm parallel group, monotherapy design was used to compare oxcarbazepine administered 1,200 mg twice daily to placebo in hospitalized patients with refractory partial seizures, including simple and complex partial seizures and partial seizures evolving to secondarily generalized seizures. Patients exited the trial after completing the 10-day double-blind treatment phase or after experiencing four partial seizures, two new-onset secondarily generalized seizures, serial seizures, or status epilepticus, whichever came first. RESULTS: Analysis of the primary efficacy variable--time to meeting one of the exit criteria--showed a statistically significant effect in favor of oxcarbazepine (p = 0.0001). The secondary efficacy variables--percentage of patients who met one of the exit criteria (p = 0.0001) and total partial seizure frequency per 9 days during the double-blind treatment (p = 0.0001)--were also statistically significant in favor of oxcarbazepine. CONCLUSION: These results demonstrate that oxcarbazepine given as monotherapy is effective and safe for the treatment of partial seizures in this paradigm.

Adolescent↗
PubMed1999

Parental beliefs about managing sibling conflict.

This study examined the correspondence between parents' beliefs about the most effective ways to manage sibling conflict and their responses to their children's spontaneous sibling conflicts. Eighty-eight 2-child, 2-parent families participated in 3 home sessions. Second-born children were 3-5 years old, and firstborn children were 2-4 years older. Parents' use of a particular conflict management strategy was based, in part, on their perception of how effective the strategy was and how well they could carry out the strategy. For example, mothers' use of child-centered strategies was predicted by their belief that parental control strategies were ineffective. Fathers' use of control strategies was predicted by their low confidence in enacting child-centered techniques. Although both mothers and fathers perceived child-centered and control strategies as more effective than passive nonintervention, parents engaged in passive nonintervention most often.

Adult↗
PubMed1999

Inflicted traumatic brain injury: relationship of developmental outcome to severity of injury.

Inflicted traumatic brain injury (TBI) is a frequent consequence of physical child abuse in infants and children. Twenty-eight children who were 2-42 months of age when hospitalized for moderate to severe TBI were enrolled in a prospective, longitudinal study of neurobehavioral outcome following acquired brain injury. Relative to a comparison group, the children with inflicted TBI had significant deficits in cognitive, motor and behavioral domains when assessed with the Bayley Scales of Infant Development-II 1 and 3 months after the injury. Nearly half of the injured children showed persisting deficits in attention/arousal, emotional regulation and motor coordination. Greater injury severity, as indicated by lower coma scale scores, longer periods of unconsciousness and the presence of edema/cerebral infarctions was associated with poorer outcomes in all domains.

Battered Child Syndrome↗
PubMed1998

[Prognostic factors in acute liver failure].

Acute liver failure is defined as acute severe, potentially reversible hepatic failure complicated by cerebral dysfunction. The high mortality rate of between 50% and 90% justifies early transfer to a specialised centre with the possibility of orthotopic liver transplantation to ensure adequate intensive care monitoring and treatment, 57 patients with acute liver failure (34 female, 23 male, aged 6 to 87 years, median 33 years) treated at our intensive care unit during the past 10 years were analysed retrospectively. Various factors and laboratory data were analysed in respect to their prognostic value. Depending on the aetiology, the survival rate in acute liver failure under conservative treatment ranges from 79% (amanita intoxication) to 10% (cryptogenic genesis). The most important predictive parameter is the extent of cerebral dysfunction. The extent of cerebral dysfunction is a determining factor of the survival rate under conservative treatment; it ranges from 94% (patients with hepatic encephalopathy grade I) to 11% (patients with hepatic encephalopathy grade IV). The occurrence of complications such as infections, cerebral oedema, respiratory failure or renal failure is also associated with an unfavourable outcome. Additionally, various laboratory parameters have a predictive ability. The mortality rate of our patients with acute liver failure has decreased from 56% to 32% since early intensive care monitoring and treatment and the possibility of acute orthotopic liver transplantation were established.

Adolescent↗
PubMed1998

Neospora caninum infection in a Bernese cattle dog from Italy.

A cutaneous nodule associated with Neospora caninum infection was diagnosed in a 5-year-old male Bernese cattle dog from Italy. The ulcerative lesion was 2-3 cm wide located in the skin of the tarsal region. Haematological values were normal and the dog did not show any neurological abnormalities. The dermal lesion consisted of a diffuse necrotic dermatitis with a dense infiltrate of mostly neutrophils and macrophages, surrounded by a fibrous wall. Histological sections revealed numerous tachyzoites of N. caninum scattered throughout the tissue. Diagnosis was confirmed both by immunohistochemical staining and electron microscopic examination. The dog had a 1:640 IFAT titre to N. caninum. Four weeks after surgical excision new subcutaneous nodules reappeared. The cutaneous lesions resolved following 21 days of therapy with clindamycin hydrochloride. These observations demonstrate the presence of N. caninum in Italy and confirm that neosporosis should be considered in the differential diagnosis of pyogranulomatous dermatitis in dogs. Clindamycin may be an effective treatment for cutaneous neosporosis.

Animals↗
PubMed1998

Isradipine prevents global and regional cocaine-induced changes in brain blood flow: a preliminary study.

The L-type calcium channel antagonist, isradipine, reduces brain ischemia in animal models of ischemic stroke. These effects of isradipine appear more pronounced in dopamine (DA) rich brain regions. These same DA-rich brain regions have also been shown to be the areas most affected by cocaine-induced ischemic changes. Using a novel quantified approach to single photon emission computerized tomography, we demonstrated that isradipine pre-treatment prevented cocaine-induced ischemic changes, especially in these DA-rich brain regions. This is the first demonstration that any medication, including isradipine, can prevent the ischemic effects of cocaine on brain blood flow. Isradipine may, therefore, be a useful therapeutic agent for the prevention of brain ischemia in cocaine addicts.

Adult↗
PubMed1998

Demonstration of dose-dependent global and regional cocaine-induced reductions in brain blood flow using a novel approach to quantitative single photon emission computerized tomography.

Ischemic stroke is a common cause of morbidity and mortality in cocaine addicts. Because the previous semiquantitative single photon emission computerized tomography (SPECT) method for measuring brain blood flow does not quantify blood flow, the magnitude and specificity of cocaine's effects during drug taking has not been well established. Here, using a novel quantitative approach to SPECT, we established that intravenous cocaine administration to nine recently abstinent cocaine-dependent subjects was associated with significant decreases in global and regional brain blood flow to dopamine-rich areas such as the prefrontal, frontal temporal, and subcortical gray matter. Establishing the utility of this relatively new quantitative SPECT technique provides an important tool for the management of vascular disorders of the brain. Additionally, identifying the site-specific effects of cocaine provides targets for the development of putative therapeutic medications to attenuate or minimize ischemic stroke in cocaine addicts.

Adolescent↗