Search results for "TRACER"
showing 10 items of 145 documents
On the structure of the extra-tropical transition layer from in-situ observations
2012
Abstract. In-situ observations of atmospheric tracers from multiple measurement campaigns over the period 1994–2007 were combined to investigate the Extra-tropical Transition Layer (ExTL) region and the properties of large scale meridional transport. We used potential temperature, equivalent latitude and distance relative to the local dynamical tropopause as vertical coordinates to highlight the behaviour of trace gases in the tropopause region. Vertical coordinates based on constant PV surfaces allowed us to relate the dynamical definition of the tropopause with trace gases distributions and vertical gradients and hence analyse its latitudinal dependence and seasonal variability. Analysis …
<title>Noninvasive detection of intracerebral hemorrhage using near-infrared spectroscopy (NIRS)</title>
1998
Intracerebral Hemorrhage (IH) is an important cause of secondary brain injury in neurosurgical patients. Early identification and treatment improve neurologic outcome. We have tested Near Infrared Spectroscopy (NIRS) as an alternative noninvasive diagnostic tool compared to CT-Scans to detect IH. We prospectively studied 212 patients with neurologic symptoms associated with intracranial pathology before performing a CT-scan. NIRS signals indicated pathologies in 181 cases (sensitivity 0.96; specificity 0.29). In a subgroup of subdural hematomas NIRS detected 45 of 46 hematomas (sensitivity 0.96; specificity 0.79). Identification of intracerebral hemorrhage using NIRS has the potential to al…
Transient Focal Neurological Events in Cerebral Amyloid Angiopathy and the Long-term Risk of Intracerebral Hemorrhage and Death: A Systematic Review …
2021
Importance Transient focal neurological episodes (TFNEs) are a frequently overlooked presentation of cerebral amyloid angiopathy (CAA), a condition with prognostic implications that are still not well described. Objective To perform a systematic review and meta-analysis to examine the factors associated with incident lobar intracerebral hemorrhage (ICH) and death in patients with CAA presenting with TFNEs. Data Sources A systematic review and individual participant meta-analysis including (1) a hospital-based cohort and (2) the results obtained from a systematic search performed in MEDLINE and Embase completed in December 2019. Study Selection Included studies were observational reports of …
Experimental Hypertensive Intracerebral Mass Hemorrhage in Cats
1986
About two–thirds of all patients with spontaneous intracerebral hemorrhage suffer from systemic hypertension. Additionally systemic hypertension is the main factor indicating a poor prognosis of intracerebral hemorrhage. This has been shown in our statistical evaluation of 117 cases of conservatively treated spontaneous intracerebral hemorrhage. More than 48% of the hypertensive patients died, but only 30% of the normotensive patients (Fig. 1). In an experimental study we investigated the influence of systemic hypertension and normotension on epidural pressure and on the formation of brain edema during the first 12 h after artificial intracerebral hemorrhage.
The Influence of Systemic Hypertension on Intracranial Pressure and Edema Formation in Experimental Intracerebral Hemorrhage
1986
Systemic hypertension is not only the most frequent cause of intracerebral hemorrhage but also the most important complication of this disease. In our clinical investigation of 117 cases almost 70% of the patients suffered from systemic hypertension. Despite advances in diagnosis (Schiirmann, Dei Anang, 1980) mortality of hypertensive patients was 48%. Normotensive hemorrhages showed a better prognosis: only 31% of the patients died and 33% (17% in hypertensive patients) obtained good neurological recovery (Wallenfang et al., 1985).
Les accidents vasculaires cérébraux du nouveau-né et de l’enfant
2009
The clinical presentation, risk factors, causes, vital or functional prognosis, and acute management options for stroke occurring in neonates and children are specific, differing from those observed in young adults. Compared with the adult population, less is known about the epidemiology of stroke in the under-18 population where the disease could become more frequent because of advances in both neonatal resuscitation techniques for cerebral disorders and neuroimaging techniques enabling the diagnosis of small lesions. Clinical features are often delayed, especially in neonates, and unlike epilepsy or dystonia of the affected limb, which are frequent complications, aphasia is rather rare. T…
Postlumbar Puncture Headache Syndrome
2003
Publisher Summary This chapter presents a study on acute and chronic pain related to postlumbar puncture headache syndrome. The symptoms of the postlumbar puncture headache (PLPH) syndrome are positional, beginning in the upright posture and subsiding or improving when the patient reclines. Sometimes symptoms of PLPH occur spontaneously without a detectable dural defect. In these instances, suggested causes include a hyperactive resorption of cerebrospinal fluid (CSF) or a spontaneous mechanical dural hole. Magnetic resonance imaging (MRI) scans in patients with intracranial hypotension—either after LP or spontaneously—show meningeal enhancement, subdural effusions, and downward brain displ…
EEG-Befunde bei ALL-Patienten 10 Jahre nach Bestrahlung und Zytostatikatherapie
1990
35 patients with acute lymphoblastic leukemia were studied electroencephalographically during a period of 5 to 10 years (median 9 years) after diagnosis. During this time 51% of the patients intermittently showed changes in the background activity, which may indicate discrete CNS-lesions. All but one patient, suffering from an intracerebral hemorrhage, had normal EEGs at the end of the individual observation period.
A New Tool for the Analysis of the Effect of Intracerebrally Injected Anti-Amyloid-β Compounds
2021
Background: A wide range of techniques has been developed over the past decades to characterize amyloid-β (Aβ) pathology in mice. Until now, no method has been established to quantify spatial changes in Aβ plaque deposition due to targeted delivery of substances using ALZET® pumps. Objective: Development of a methodology to quantify the local distribution of Aβ plaques after intracerebral infusion of compounds. Methods: We have developed a toolbox to quantify Aβ plaques in relation to intracerebral injection channels using Zeiss AxioVision® and Microsoft Excel® software. For the proof of concept, intracerebral stereotactic surgery was performed in 50-day-old APP-transgenic mice injected wit…
Isomerism of [64Cu-NOTA-Bn]-labeled radiotracers: separation of two complex isomers and determination of their interconversion energy barrier using i…
2011
The model complex [(64)Cu((S)-p-NH(2)-Bn-NOTA)](-) ([(64)Cu]1) was used to study the isomerism of [(64)Cu-NOTA-Bn]-labeled radiotracers. Two complex isomers [(64)Cu]1a and [(64)Cu]1b, which were formed at a ratio of 1:9 during the complexation of [(64)Cu]Cu(2+) with (S)-p-NH(2)-Bn-NOTA, were separated using ion pair chromatography. To study the interconversion, the nonradioactive complex isomers Cu1a and Cu1b were separated and thermally treated at 90 °C in both ammonium acetate solution and deionized water. A faster interconversion rate was observed for both isomers with lower concentrations of ammonium ions. At the end of reaction, the thermodynamic Cu1a to Cu1b equilibrium ratio was 6:94…