Search Results - (Author, Cooperation:M. Paganini)

2015-07-24

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Animals ; *Biodiversity ; Conservation of Natural Resources/methods ; Ecological Parameter Monitoring/instrumentation/*methods ; Ecology/instrumentation/*methods/standards ; Environmental Policy ; *Satellite Imagery

1089-7690

AIP Digital Archive

Physics

Chemistry and Pharmacology

The adsorption of molecular oxygen (enriched with 17O) onto high surface area MgO has been studied by electron paramagnetic resonance (EPR) spectroscopy. The oxide surface was pretreated in such a way so that surface trapped electron FS+(H) centers are produced. Subsequent dioxygen adsorption results in an electron transfer reaction from FS+(H) centers to O2, producing a surface stabilized superoxide (O2−) anion. The resulting EPR spectrum of the paramagnetic anion is complicated by the simultaneous presence of a high number of "normal" hyperfine lines along the principal axes and also by several off-axis extra features which have complicated previous interpretations of the Ayy and Azz components. By adopting a suitable adsorption procedure which suppresses the superoxide speciation, using a highly crystalline MgO material and controlling the isotopomer composition through appropriate 17O enrichments, the resolution of the EPR spectrum has been dramatically improved. Analysis of the 1H superhyperfine structure (|AH|/βeg=[3.9,2.2,1.3]G), resulting from a dipolar interaction between the adsorbed O2− anion and a neighboring OH group, and positions of the extra absorption lines in the spectrum, have provided us with auxiliary sources of information to determine for the first time the complete 17O hyperfine tensor (AO/βeg=[−76.36,7.18,8.24] G). The tensor has been analyzed in detail using a localized spin model. The spin density is shared among the 2pπx(0.495), 2pxy(−0.024) and 2s(0.011) orbitals. The total spin density on O2− indicates that a complete surface electron transfer from the FS+(H) center to dioxygen occurs upon adsorption, in line with recent ab initio calculations. © 2002 American Institute of Physics.

Electronic Resource

0167-8760

Bit color mapping ; Brain involutional process ; CNV ; Cognitive potential ; Presenium

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Medicine

Psychology

Electronic Resource

1126-5442

Key words Presenile primary dementia ; Clinical/neuropsychological examinations ; Differential diagnosis ; Seven-year follow-up

Springer Online Journal Archives 1860-2000

Medicine

Abstract Early diagnosis of presenile Alzheimer's disease (AD), which would serve for prognosis and for guiding choices of treatment, is still an important, difficult task for the clinical neurologist. We studied 24 patients, 12 of whom had minor cognitive impairment or questionable dementia (PICD) and 12 who met NINCDS-ADRDA criteria for presenile AD (PAD). Using clinical, neuropsychological, neurophysiological and neuroradiological methods, we followed the patients up to two disease end-points. All PAD patients evolved into clinically evident Alzheimer-type dementia, became untestable within 60 months and died within 72 months. Only 3 of the PICD patients became demented; 2 of them died during the follow-up and 1 died eight months later. The other 9 PICD patients showed only moderate cognitive decline, compatible with normal aging processes. Neurophysiological and neuroradiological findings might be an important tool for arriving at a correct early diagnosis, when they are assessed with clinical neuropsychological data.

Electronic Resource

1432-1920

Key words Behçet's disease ; Spinal cord ; Magnetic resonance imaging

Springer Online Journal Archives 1860-2000

Medicine

Abstract MRI demonstrated well-defined areas of signal change and moderate contrast enhancement in the thoracic spinal cord of a patient with Behçet's disease presenting with subacute myelopathy. The patient improved after intravenous steroids, and MRI 5 months later showed a normal spinal cord.

Electronic Resource

1432-1041

sodium valproate ; adverse effects ; anti-convulsants ; drug interaction ; hyperammonia ; metabolites ; epilepsy

Springer Online Journal Archives 1860-2000

Chemistry and Pharmacology

Medicine

Summary The concentrations of valproic acid (VPA) and of its metabolites 3-oxo-VPA and 4-en-VPA were measured in the plasma of 12 selected epileptic patients 1,2,3, and 4 h after administration of a loading dose of VPA. Four of the patients, all on polytherapy, had had short-term adverse effects during chronic VPA treatment, and in them there has been abnormal NH3-values after a test doese of VPA. Eight patients (4 on monotherapy and 4 on polytherapy) had been free from adverse effects. No significant difference in the VPA, 3-oxo-VPA and 4-en-VPA concentrations was found between the three groups of patients. Accumulation of 4-en-VPA is not involved in the short-term adverse effects and hyperammonaemia induced by VPA.

Electronic Resource

1432-1459

Valproic acid ; Hyperammonaemia ; Adverse effects ; Identical twins

Springer Online Journal Archives 1860-2000

Medicine

Summary The cases of two epileptic identical twins are described, one of whom had presented an episode of valproate (VPA)-induced stupor associated with very high blood ammonia (NH3) concentrations. Both twins showed a similar marked increase of venous NH3 concentrations after the administration of a single loading dose of VPA (800 mg).

Electronic Resource

1569-8041

ALL ; childhood ; L-asparaginase ; L-asparagine

Springer Online Journal Archives 1860-2000

Medicine

Abstract Purpose:The present study was aimed at investigatingL-asparaginase (L-ASE) activity (in plasma) and L-asparagine (L-ASN) depletion(in plasma and CSF) in children with newly diagnosed acute lymphoblasticleukemia (ALL) exposed for the first time to different L-ASE products. Patients and methods:During the induction treatment of the AIEOPALL 95 study, 62 patients were treated with either Erwinase® (n=15), or E. colimedac® (n= 47) L-ASE products, giveneither i.m. or i.v., at the standard dosage of 10,000 IU/m2, q 3days × 8 (first exposure). Results:Plasma and CSF L-ASN trough levels were undetectable inall cases, including those with L-ASE trough activity 〈50 mU/ml. L-ASEtrough activity during the administration of medac® was howeversignificantly higher when compared with that of Erwinase®. Conclusions:L-ASN depletion after a first exposure to standarddoses of Erwinase® or medac® is obtained in virtually all patients.No differences are seen between the I.M. or I.V. administration routes but themedac® product is associated with a significantly higher enzyme activityin respect of Erwinase®. L-ASN levels may be undetectable also in patientswith L-ASE trough activity levels 〈50 mU/ml, challenging the currentopinion that an activity level of 100 mU/ml is needed to obtain L-ASNdepletion.

Electronic Resource

1590-3478

psychometrics ; Q-EEG ; ERPs ; CNV complex ; presenile dementia ; presenile Alzheimer's disease

Springer Online Journal Archives 1860-2000

Medicine

Sommario Sono stati esaminati da un punto di vista clinico, neuropsicologico e neuro-psicofisiologico (Q-EEG, potenziali neurocognitivi del complesso CNV e tempo di reazione, TR, a segnali incondizionati) in 24 pazienti con forme più o meno gravi di deterioramento cognitivo presenile idiopatico (15 maschi e 9 femmine; età media 59.6) ed i dati sono stati confrontati con quelli raccolti in 10 soggetti sani di controllo di pari età (media 59.4). In 12 pazienti era stata formulata una diagnosi di sospetta/possibile forma iniziale presenile di demenza primaria (PICD), poiché i loro sintomi non completavano del tutto i criteri clinici del DSM III-R, dell'ICD-10 e del NINCDS-ADRDA Report proposti per le varie forme di demenza. Dodici pazienti presentavano un classico quadro clinico di iniziale demenza presenile di tipo Alzheimer (PAD). Tutti i pazienti sono stati sottoposti preliminarmente ad esami clinici, TAC, RMN, EEG con analisi spettrale e ad una batteria di test psicodiagnostici. Una valutazione statistica mediante analisi della varianza, test di correlazione ed analisi discriminante di tutti i dati neuropsicologici, neurofisiologici oltre che dei TR agli stimoli incondizionati (S2), hanno selezionato 22 singoli fattori discriminanti fra i 3 gruppi di soggetti ad un livello di significatività di p〈0.01. Ad un'analisi discriminante conclusiva 13 di questi 22 fattori hanno consentito una precisa identificazione nel 97% dei casi (33 dei 34 soggetti esaminati), e la stessa percentuale di corretta classificazione è stata ottenuta anche utilizzando i fattori discriminanti relativi ai soli dati del complesso CNV e dei TR ed S2. Con entrambi i gruppi di fattori tutti i soggetti normali ed i pazienti affetti da PAD sono stati esattamente identificati; solo 1 PICD risultò erroneamente classificato come normale con il primo gruppo di fattori discriminanti, ed un altro come PAD con il secondo gruppo di fattori. Questi risultati confermano la notevole utilità di tali metodiche non-invasive nella diagnosi precoce delle demenze primarie presenili, se correttamente eseguite ed interpretate come già dimostrato in nostre precedenti ricerche.

Abstract Clinical, neuropsychological and neuropsychophysiological data (Q-EEG, ERPs and CNV/RT activity) were obtained from 24 patients who had more or less severe presenile primary cognitive decline without depression, and compared with similar data from 10 age-matched healthy volunteers (mean age, 59.4 years). All of the patients (15 M and 9 F; mean age 59.6 years) were selected according to the DSM III-R, ICD-10 and NINCDS-ADRDA criteria and underwent CT and MRI scanning, in addition to a standard clinical examination, a battery of psychometric tests, spectral EEG, and bit-mapped CNV complex and RT to S2 analyses. Twelve of the 24 patients presented an initial presenile idiopathic cognitive decline (PICD) but did not wholly fulfil the clinical and neuropsychological criteria for primary dementia or for a diagnosis of probable AD; the remaining 12 patients showed characteristic clinical signs and symptoms of a very probable early stage of presenile Alzheimer-type dementia (PAD). ANOVA, correlational and discriminant analyses of the neuropsychological test scores, and the neurophysiological and RT to S2 data revealed 22 highest-ranked between-group discriminant factors (all with a significance level of p〈0.01). The conclusive discriminant analysis retained 13 of these factors as final canonical functions, and these showed a 97% grouping accuracy (33 of the 34 subjects examined); the same percentage of correct classifications was also achieved using only the 15 best indicators in the group of CNV/RT findings. Using both of these sets of highest-ranked discriminators, all of the normal subjects and all of the PAD patients were correctly classified; only 1 PICD patient was misclassified as normal when the first group of 13 factors was used, and another PICD patient was misclassified as PAD using the second group of 15 factors. Our findings suggest that, providing they are correctly performed and interpreted, these non-invasive techniques may be an important tool for identifying incipient stages of presenile Alzheimer-type dementia.

Electronic Resource

1590-3478

memory ; magnetic resonance imaging ; temporal lobe

Springer Online Journal Archives 1860-2000

Medicine

Sommario Sette anni dopo un'encefalite un esame di Risonanza Magnetica dimostrò un danno bilaterale dell'ippocampo in un paziente con amnesia anterograda permanente.

Abstract Seven years after encephalitis, magnetic resonance examination revealed bilateral hippocampal damage in a patient with permanent antegrade amnesia.

Electronic Resource

1590-3478

Contingent negative variation (CNV) ; post-S1 N1, P2, P3 ; reaction time ; normal adults ; presenile subjects

Springer Online Journal Archives 1860-2000

Medicine

Sammario Scopo della presente ricerca è la raccolta di dati normativi ottenuti con una nuova metodica d'analisi dell'onda d'aspettativa, delle sue principali componenti (complesso CNV) e del tempo di reazione motorio (RT) in due gruppi si soggetti normali, adulti ed in età presenile. In 20 soggetti sani (rispettivamente 10 con età media di 28.3 e 10 di 59.6 anni) per evocare il complesso CNV/RT si è adottato un parametro standard di stimolazione molto semplice ed idoneo anche per pazienti con deterioramento mentale: S1 (click)—2 sec d'intervallo —S2 (stimolo visivo)—risposta motoria con RT. Si è derivata l'attività di tipo CNV da regioni frontali, centrali e parietali. In confronto ai soggetti più giovani, modificazioni significative di alcune componenti della CNV si sono rilevate nel gruppo di soggetti in età presenile senza apparente declino delle performances comportamentali e cognitive. Tali modificazioni appaiono indicative delle fasi iniziali dei processi involutivi encefalici fisiologici associati a minimi e sublinici deficit delle risposte d'orientamento, attenzione, concentrazione, memoria a breve termine, capacità di preparazione alle risposte motorie sollecitate da S2. Vengono discusse le implicazioni cliniche ed in particolare l'importanza diagnostica di questo tipo di indagini nel riconoscimento dei primi stadi nel presenium dell'involuzione fisiologica o patologica dell'encefalo.

Abstract 20 selected right-handed very healthy subjects (10 young adults and 10 presenile subjects mean age 28.3 and 59.6) were tested for CNV activity with a simple warned reaction time (RT) paradigm. EEG and CNV components (post-S1, N1, P2, P3; early CNV; N1200 late CNV; CNV resolution) were recorded from Fz, C3, Cz, C4, P3, Pz, and P4, referenced to linked mastoid electrodes. EOG, RT and stimuli were also recorded. The presenile group differed significanty from the younger group in the auditory post-S1 N1 and P3, and in the early (O-wave) and late (P-wave) CNV complex components. A progressive amplitude reduction only in frontal leads between O-wave and P-wave with the lowest point being reached in the P-wave was characteristic in the presenile group. Further, presenile subjects showed relatively flat CNV waveshapes of low amplitude and, as a whole, performed a little less well than young persons. This finding suggests that the statistically significant changes in post-S1 EPRs and CNV activity recorded in our presenile subjects, without appreciable deficits in behavioral and mental performance, could be alerting signs of early brain involutional processes related to minimal and subclinical decrement of orienting, attentiveness and response preparation capabilities. If such is the case and it could be confirmed in a larger sample of very healthy subjects, these age-related changes in the presenium could be of considerable practical importance for clinical and research applications.

Electronic Resource

1590-3478

Contingent negative variation ; RT ; presenile cognitive decline ; presenile Alzheimer dementia

Springer Online Journal Archives 1860-2000

Medicine

Sommario Scopo della presente ricerca è lo studio mediante metodiche standard di averaging, delle modificazione dell'onda d'aspettativa, sue principali componenti (complesso CNV) e tempo di reazione (RT) delle risposte motorie in pazienti affetti da forme iniziali più o meno gravi di decadimento mentale presenile idiopatico. Sono stati esaminati 19 pazienti (età media: 59.5) e 10 soggetti sani di controllo di pari età (media: 59.6). Otto pazienti presentavano un quadro clinico di demenza presenile di tipo Alzheimer (PAD), mentre in 11 soggetti era stata formulata una diagnosi di possibile forma iniziale presenile di demenza primaria (PICD) poiché non raggiungevano i criteri clinici del DSM-III e del NINCDS-ADRDA Report. Tutti i pazienti sono stati sottoposti preliminarmente and esami clinici, TAC, NMR, EEG con analisi spettrale ed a test psicodiagnostici. Per evocare il complesso CNV-RT si è adottato un parametro di stimolazione molto semplice ed idoneo anche per malati con deterioramento mentale. Oltre all'EOG ed agli RT, l'attività di tipo CNV è stata registrata da regioni frontali, centrali e parietali con referenza bimastoidea. Si sono osservate differenze significative di alcuni componenti fra i gruppi di soggetti esaminati e nella maggioranza dei dementi mancava una vera attività di tipo CNV, gli RT erano enormemente prolungati e sovente si sono registrati caratteristici “post-imperative negative variations” (PINV). I risultati ottenuti confermano l'utilità di queste metodiche nella diagnosi precoce delle demenze primarie presenili.

Abstract The so-called contingent negative variation (CNV) is a slow brain potential representing a complex of variously overlapped “endogenous” components of behavior related to different reasonably well-known neurocognitive processes. CNV complex evoked with a standard paradigm (S1-2 sec-S2-motor response) and reaction time (RT) to imperative signal (S2) were recorded and measured in 11 patients with initial presenile idiopathic cognitive decline (PICD), 8 with presenile Alzheimer-type dementia (PAD) and 10 healthy age-matched controls. Significant group differences were obtained for measures of some CNV components, particularly of the late pre-S2 CNV. No significant CNV activity, very prolonged RTs and sometimes characteristic post-imperative negative variation (PINV) were observed in the majority of patients with PAD. These results suggest that CNV complex and RT changes similar to those observed in our patients may constitute a valuable clue for the study of pathophysiological brain functioning in the early stages of presenile idiopathic mental deterioration.

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