803 research outputs found
Cerebrospinal fluid ferritin—Unspecific and unsuitable for disease monitoring
Background and purpose
Subarachnoid hemorrhage is sometimes difficult to diagnose radiologically. Cerebrospinal fluid (CSF) ferritin has been proposed to be highly specific and sensitive to detect hemorrhagic central nervous system (CNS) disease. We analyzed here the specificity of CSF ferritin in a large series of various CNS diseases and the influence of serum ferritin.
Materials and methods
CSF ferritin, lactate, protein and total cell count were analyzed in 141 samples: neoplastic meningitis (n=62), subarachnoid hemorrhage (n=20), pyogenic infection (n=10), viral infection (n=10), multiple sclerosis (n=10), borreliosis (n=5) and normal controls (n=24). Cerebrospinal fluid ferritin was measured with a microparticle immunoassay. In addition, serum and CSF ferritin were compared in 18 samples of bacterial and neoplastic meningitis.
Results
In CNS hemorrhage, median ferritin was 51.55μg/L (sensitivity: 90%) after the second lumbar puncture. In neoplastic meningitis, the median CSF ferritin was 16.3μg/L (sensitivity: 45%). Interestingly, ferritin was higher in solid tumors than that in hematological neoplasms. In 90% of pyogenic inflammation, ferritin was elevated with a median of 53.35μg/L, while only 50% of patients with viral infection had elevated CSF ferritin. In ventricular CSF, median ferritin was 163μg/L, but only 20.6μg/L in lumbar CSF. Ferritin was normal in multiple sclerosis and borreliosis.
Conclusions
Ferritin was elevated not only in hemorrhagic disease, but also in neoplastic and infectious meningitis. Ferritin was not a reliable marker of the course of disease. The influence of serum ferritin on CSF ferritin is negligible. We conclude that elevated CSF ferritin reliably, but unspecifically indicates severe CNS disease
Sex Differences in Semantic Processing: Event-Related Brain Potentials Distinguish between Lower and Higher Order Semantic Analysis during Word Reading
Behavioral studies suggest that women and men differ in the strategic elaboration of verbally encoded information especially in the absence of external task demand. However, measuring such covert processing requires other than behavioral data. The present study used event-related potentials to compare sexes in lower and higher order semantic processing during the passive reading of semantically related and unrelated word pairs. Women and men showed the same early context effect in the P1-N1 transition period. This finding indicates that the initial lexical-semantic access is similar in men and women. In contrast, sexes differed in higher order semantic processing. Women showed an earlier and longer lasting context effect in the N400 accompanied by larger signal strength in temporal networks similarly recruited by men and women. The results suggest that women spontaneously conduct a deeper semantic analysis. This leads to faster processing of related words in the active neural networks as reflected in a shorter stability of the N400 map in women. Taken together, the findings demonstrate that there is a selective sex difference in the controlled semantic analysis during passive word reading that is not reflected in different functional organization but in the depth of processin
Glioblastoma: is there any blood biomarker with true clinical relevance?
Glioblastoma (GBM) is the most frequent malignant primary brain tumor in adults, characterized by a highly aggressive, inflammatory and angiogenic phenotype. It is a remarkably heterogeneous tumor at several levels, including histopathologically, radiographically and genetically. The 2016 update of the WHO Classification of Tumours of the Central Nervous System highlighted molecular parameters as paramount features for the diagnosis, namely IDH1/2 mutations that distinguish primary and secondary GBM. An ideal biomarker is a molecule that can be detected/quantified through simple non- or minimally invasive methods with the potential to assess cancer risk; promote early diagnosis; increase grading accuracy; and monitor disease evolution and treatment response, as well as fundamentally being restricted to one aspect. Blood-based biomarkers are particularly attractive due to their easy access and have been widely used for various cancer types. A number of serum biomarkers with multiple utilities for glioma have been reported that could classify glioma grades more precisely and provide prognostic value among these patients. At present, screening for gliomas has no clinical relevance. This is because of the low incidence, the lack of sensitive biomarkers in plasma, and the observation that gliomas may develop apparently de novo within few weeks or months. To the best of our knowledge, there is no routine use of a serum biomarker for clinical follow-up. The purpose of this paper is to review the serum biomarkers described in the literature related to glioblastoma and their possible relationship with clinical features
Two Automatic Approaches for Analyzing Connected Speech Processes in Dutch
This paper describes two automatic approaches used to study connected speech processes (CSPs) in Dutch. The first approach was from a linguistic point of view - the top-down method. This method can be used for verification of hypotheses about CSPs. The second approach - the bottom-up method -uses a constrained phone recognizer to generate phone transcriptions. An alignment was carried out between the two transcriptions and a reference transcription. A comparison between the two methods showed that 68% agreement was achieved on the CSPs. Although phone accuracy is only 63%, the bottom-up approach is useful for studying CSPs. From the data generated using the bottom-up method, indications of which CSPs are present in the material can be found. These indications can be used to generate hypotheses which can then be tested using the top-down method
Increased functional sensorimotor network efficiency relates to disability in multiple sclerosis
BACKGROUND: Network abnormalities could help explain physical disability in multiple sclerosis (MS), which remains poorly understood. OBJECTIVE: This study investigates functional network efficiency changes in the sensorimotor system. METHODS: We included 222 MS patients, divided into low disability (LD, Expanded Disability Status Scale (EDSS) ⩽3.5, n = 185) and high disability (HD, EDSS ⩾6, n = 37), and 82 healthy controls (HC). Functional connectivity was assessed between 23 sensorimotor regions. Measures of efficiency were computed and compared between groups using general linear models corrected for age and sex. Binary logistic regression models related disability status to local functional network efficiency (LE), brain volumes and demographics. Functional connectivity patterns of regions important for disability were explored. RESULTS: HD patients demonstrated significantly higher LE of the left primary somatosensory cortex (S1) and right pallidum compared to LD and HC, and left premotor cortex compared to HC only. The logistic regression model for disability (R2 = 0.38) included age, deep grey matter volume and left S1 LE. S1 functional connectivity was increased with prefrontal and secondary sensory areas in HD patients, compared to LD and HC. CONCLUSION: Clinical disability in MS associates with functional sensorimotor increases in efficiency and connectivity, centred around S1, independent of structural damage
Guidelines for the recording and evaluation of pharmaco-EEG data in man: the International Pharmaco-EEG Society (IPEG)
The International Pharmaco-EEG Society (IPEG) presents updated guidelines summarising the requirements for the recording and computerised evaluation of pharmaco-EEG data in man. Since the publication of the first pharmaco-EEG guidelines in 1982, technical and data processing methods have advanced steadily, thus enhancing data quality and expanding the palette of tools available to investigate the action of drugs on the central nervous system (CNS), determine the pharmacokinetic and pharmacodynamic properties of novel therapeutics and evaluate the CNS penetration or toxicity of compounds. However, a review of the literature reveals inconsistent operating procedures from one study to another. While this fact does not invalidate results per se, the lack of standardisation constitutes a regrettable shortcoming, especially in the context of drug development programmes. Moreover, this shortcoming hampers reliable comparisons between outcomes of studies from different laboratories and hence also prevents pooling of data which is a requirement for sufficiently powering the validation of novel analytical algorithms and EEG-based biomarkers. The present updated guidelines reflect the consensus of a global panel of EEG experts and are intended to assist investigators using pharmaco-EEG in clinical research, by providing clear and concise recommendations and thereby enabling standardisation of methodology and facilitating comparability of data across laboratories
Comparison between expert listeners and continuous speech recognizers in selecting pronunciation variants.
In this paper, the performance of an automatic transcription tool is evaluated. The transcription tool is a continuous speech recognizer (CSR) which can be used to select pronunciation variants (i.e. detect insertions and deletions of phones). The performance of the CSR was compared to a reference transcription based on the judgments of expert listeners. We investigated to what extent the degree of agreement between the listeners and the CSR was affected by employing various sets of phone models (PMs). Overall, the PMs perform more similarly to the listeners when pronunciation variation is modeled. However, the various sets of PMs lead to different results for insertion and deletion processes. Furthermore, we found that to a certain degree, word error rates can be used to predict which set of PMs to use in the transcription tool
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Grow Tubes Change Microclimate and Bush Architecture but Have Little Effect on Bush Biomass Allocation at the End of the Establishment Year in Blueberry
Microclimate variables were integrated over a 6-month period during which blueberry (Vaccinium corymbosum cv. Liberty) bushes were grown in 51-cm high, 20-cm diameter round grow tubes (opaque or translucent) on a sawdust mulch-covered raised bed with the mulch incorporated into tilled soil. Grow tubes were installed around plants in the spring of 2006, 5 months after planting. Total photosynthetic photon flux (PPF) density was 55% and 21% of ambient in translucent and opaque tubes, respectively. Daily maximum vapor pressure deficit consistently was highest in translucent tubes. Air (T[subscript a]) and stem (T[subscript stem]) temperatures in both grow tube types exceeded T[subscript a] and T[subscript stem] in non-tubed plants (ambient). Maximum mulch surface temperature (T[subscript m]) was lowest in opaque tubes, whereas there was no difference in T[subscript m] between ambient and translucent tubes. The soil–mulch interface temperature (T[subscript sm]) was warmer outside tubes than T[subscript sm] inside tubes. Soil temperatures directly under the tubes differed very little between tube types and ambient, generally less than 1°C. Root and crown dry mass (DM) did not differ between tubed plants and ambient at the end of the establishment year. Leaf area, leaf DM, and fruit bud number were suppressed inside tubes. All plants were greater than 51 cm tall at the end of the growing season. Substantial compensatory growth occurred above tubes: tubed plants were more upright and had more leaf area, leaf DM, and shoot growth than ambient plants above 51 cm. However, there was no difference between tubed and ambient plants in fruit bud number, total plant leaf area, shoot:root, or DM of 1- and 2-year-old wood. Grow tubes can alter microclimate and architecture of young blueberry bushes but have no significant influence on size and distribution of total DM after one growing season in the field.This is the publisher’s final pdf. The published article is copyrighted by the American Society for Horticultural Science and can be found at: http://hortsci.ashspublications.org/.Keywords: Tree shelter, Vaccinium corymbosum, Mulch, Temperature, Radiatio
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