8 research outputs found
Recovery from Transient Global Amnesia Following Restoration of Hippocampal and Fronto–Cingulate Perfusion
No full textA patient who suffered a transient global amnesia (TGA) attack underwent regional cerebral blood flow (rCBF) SPECT imaging and neuropsychological testing in the acute phase, after one month and after one year. Neuropsychological testing in the acute phase showed a pattern of anterograde and retrograde amnesia, whereas memory was within age normal limits at follow up. SPECT data were analysed with a within subject comparison and also compared with those of a group of healthy controls. Within subject comparison between the one month follow up and the acute phase detected increases in rCBF in the hippocampus bilaterally; further rCBF increases in the right hippocampus were detected after one year. Compared to controls, significant hypoperfusion was found in the right precentral, cingulate and medial frontal gyri in the acute phase; after one month significant hypoperfusion was detected in the right precentral and cingulate gyri and the left postcentral gyrus; after one year no significant hypoperfusion appeared. The restoration of memory was paralleled by rCBF increases in the hippocampus and fronto-limbic-parietal cortex; after one year neither significant rCBF differences nor cognitive deficits were detectable. In conclusion, these data indicate that TGA had no long lasting cognitive and neural alterations in this patient
Italian norms for the Freedman version of the Clock Drawing Test.
No full textThe Clock Drawing Test (CDT) is a valid screening tool for the evaluation of cognitive decline. This study aimed to compute standardized norms for the Freedman version of the CDT in a population of 248 healthy Italian individuals aged from 20 to 89 years.The effects of age, education, and gender on performance were assessed. Three conditions were administered: free-drawn clock (FD), which required participants to draw the contour, numbers, hands, and center of the clock; predrawn clock (PD), in which numbers, hands, and center had to be included in a predrawn contour; examiner-drawn clock (ED), in which only hands and center had to be inserted in a template including a predrawn contour and numbers. Scores for each of the single conditions and a total score were calculated.Age had no effect on the FD condition, whereas a significant effect of age was found for the PD and ED conditions and the total score. Gender and education had no influence on any of the scores. Correction grids, cutoffs, and equivalent scores were computed.Standardized norms for the Freedman version of the CDT were collected in a large sample of healthy individuals. No adjustments were required for scores on the free-drawn condition, whereas raw scores on the predrawn and examiner-drawn conditions and the total score needed adjustments to account for age effects. The availability of standardized norms for this version of the CDT could increase the use of this comprehensive tool in the detection of dementia
Treatment of slaughterhouse wastewaters using anaerobic filters
No full textIn this paper a laboratory-scale experimentation allowed comparing the performances of two upflow anaerobic packed-bed (UPB) filters filled with different packing materials and operating at mesophilic conditions (30°C) for treating slaughterhouse wastewaters. Methane production was experimentally evaluated considering different volumetric
organic loading rates as well as feeding overloading conditions. Although filter performances declined with loading rates higher than 6 kg CODin m-3 d-1 , the COD removal efficiency remained always above 60%. The experimental results allowed determining kinetic parameters for bacterial growth rate and methane production, following Monod and Chen-Hashimoto models respectively. Results demonstrated that the reactors reached a cellular retention time significantly greater than the hydraulic retention time. The kinetic parameter values (Ks, ;max) revealed the low microorganisms affinity for the substrate and confirmed the moderate biodegradability of slaughterhouse wastewater. The kinetic analysis allowed also the comparison of the filters
performances with another anaerobic system and the assessment of the parameters useful for real-scale plant design. The system design, applied to a medium-sized
Argentinean slaughterhouse, demonstrated to (i) be energetically self-sufficient and (ii) contribute to the plant water heating requirements
Active Dendrites Enhance Neuronal Dynamic Range
No full text12 pages, 6 figures.Since the first experimental evidences of active conductances in dendrites, most neurons have been shown to exhibit dendritic excitability through the expression of a variety of voltage-gated ion channels. However, despite experimental and theoretical efforts undertaken in the past decades, the role of this excitability for some kind of dendritic computation has remained elusive. Here we show that, owing to very general properties of excitable media, the average output of a model of an active dendritic tree is a highly non-linear function of its afferent rate, attaining extremely large dynamic ranges (above 50 dB). Moreover, the model yields double-sigmoid response functions as experimentally observed in retinal ganglion cells. We claim that enhancement of dynamic range is the primary functional role of active dendritic conductances. We predict that neurons with larger dendritic trees should have larger dynamic range and that blocking of active conductances should lead to a decrease in dynamic range.[Author Summary] Most neurons present cellular tree-like extensions known as dendrites, which receive input signals from synapses with other cells. Some neurons have very large and impressive dendritic arbors. What is the function of such elaborate and costly structures? The functional role of dendrites is not obvious because, if dendrites were an electrical passive medium, then signals from their periphery could not influence the neuron output activity. Dendrites, however, are not passive, but rather active media that amplify and support pulses (dendritic spikes). These voltage pulses do not simply add but can also annihilate each other when they collide. To understand the net effect of the complex interactions among dendritic spikes under massive synaptic input, here we examine a computational model of excitable dendritic trees. We show that, in contrast to passive trees, they have a very large dynamic range, which implies a greater capacity of the neuron to distinguish among the widely different intensities of input which it receives. Our results provide an explanation to the concentration invariance property observed in olfactory processing, due to the very similar response to different inputs. In addition, our modeling approach also suggests a microscopic neural basis for the century old psychophysical laws.The authors acknowledge financial support from Brazilian agencies Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), CAPES
and FACEPE, as well as special programs PRONEX and Instituto Nacional de Ciência e Tecnologia em Interfaces Cérebro-Máquina (INCEMAQ). LLG was also
supported by the European Commission Project GABA (FP6-NEST Contract 043309) and the Spanish MCyT and Feder under Project FISICO (FIS-2004-00953).Peer reviewe
The Qualitative Scoring MMSE Pentagon Test (QSPT): A New Method for Differentiating Dementia with Lewy Body from Alzheimer’s Disease
No full textThe differential diagnosis across different variants of degenerative diseases is sometimes controversial. This study aimed to validate a qualitative scoring method for the pentagons copy test (QSPT) of Mini-Mental State Examination (MMSE) based on the assessment of different parameters of the pentagons drawing, such as number of angles, distance/intersection, closure/opening, rotation, closing-in, and to verify its efficacy to differentiate dementia with Lewy Body (DLB) from Alzheimer's disease (AD). We established the reliability of the qualitative scoring method through the inter-raters and intra-subjects analysis. QSPT was then applied to forty-six AD and forty-six DLB patients, using two phases statistical approach, standard and artificial neural network respectively. DLB patients had significant lower total score in the copy of pentagons and number of angles, distance/intersection, closure/opening, rotation compared to AD. However the logistic regression did not allow to establish any suitable modeling, whereas using Auto-Contractive Map (Auto-CM) the DLB was more strongly associated with low scores in some qualitative parameters of pentagon copying, i.e. number of angles and opening/closure and, for the remaining subitems of the MMSE, in naming, repetition and written comprehension, and for demographic variables of gender (male) and education (6–13 years). Twist system modeling showed that the QSPT had a good sensitivity (70.29%) and specificity (78.67%) (ROC-AUC 0.74). The proposed qualitative method of assessment of pentagons copying used in combination with non-linear analysis, showed to be consistent and effective in the differential diagnosis between Lewy Body and Alzheimer’s dementia
P4‐085: An exploratory analysis of variables associated with MCI evolution through data mining with novel artificial neural networks
No full text
Are hospitalized or ambulatory patients with heart failure treated in accordance with European Society of Cardiology guidelines? Evidence from 12,440 patients of the ESC Heart Failure Long-Term Registry.
No full textAimsTo evaluate how recommendations of European guidelines regarding pharmacological and non-pharmacological treatments for heart failure (HF) are adopted in clinical practice.Methods and resultsThe ESC-HF Long-Term Registry is a prospective, observational study conducted in 211 Cardiology Centres of 21 European and Mediterranean countries, members of the European Society of Cardiology (ESC). From May 2011 to April 2013, a total of 12 440 patients were enrolled, 40.5% with acute HF and 59.5% with chronic HF. Intravenous treatments for acute HF were heterogeneously administered, irrespective of guideline recommendations. In chronic HF, with reduced EF, renin-angiotensin system (RAS) blockers, beta-blockers, and mineralocorticoid antagonists (MRAs) were used in 92.2, 92.7, and 67.0% of patients, respectively. When reasons for non-adherence were considered, the real rate of undertreatment accounted for 3.2, 2.3, and 5.4% of the cases, respectively. About 30% of patients received the target dosage of these drugs, but a documented reason for not achieving the target dosage was reported in almost two-thirds of them. The more relevant reasons for non-implantation of a device, when clinically indicated, were related to doctor uncertainties on the indication, patient refusal, or logistical/cost issues.ConclusionThis pan-European registry shows that, while in patients with acute HF, a large heterogeneity of treatments exists, drug treatment of chronic HF can be considered largely adherent to recommendations of current guidelines, when the reasons for non-adherence are taken into account. Observations regarding the real possibility to adhere fully to current guidelines in daily clinical practice should be seriously considered when clinical practice guidelines have to be written. © 2013 Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2013. For permissions please email: [email protected]
