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Biomedical subjects

M Paganini

Publications and source records attributed to M Paganini.

At least 19 recordsLinked to original sources

Identification, molecular biotyping and ultrastructural studies of bacterial communities isolated from two damaged frescoes of St Damian's Monastery in Assisi.

AIM: To investigate the composition of the microbial community in biodeterioration of two frescoes in St Damian's Monastery in Assisi. METHODS AND RESULTS: A total of 1292 colonies were isolated from the most deteriorated parts, analysed by microbiological, biomolecular and ultrastructural techniques, and taxonomically classified. Molecular biotyping of Staphylococcus cohnii colonies, one of the most prevalent bacterial species, showed a very restricted genome diversity while Bacillus licheniformis were very homogeneous by RFLP, tDNA-PCR and random-amplified polymorphic DNA. Electron microscopy confirmed heterogeneity of the bacterial population in the different sampling areas. CONCLUSIONS: Several of the identified species are widespread in the soil or saprophytes of human skin. Although unable to demonstrate that they are involved in biodeterioration, they may represent trophic elements contributing to fungi-related chromatic alterations when adequate environmental conditions occur. Deterioration may in part be prevented or controlled by adequate air filtering or conditioning of the room.

Alcaligenes↗

Deficit of short-term memory in newly diagnosed untreated parkinsonian patients: reversal after L-dopa therapy.

We assessed the effect of pathology and L-dopa therapy on attention, working memory, and executive functions, in newly diagnosed Parkinson's disease patients. Twenty-one consecutive outpatients who met the criteria for de novo Parkinson's disease, and were naive for L-dopa therapy, were observed for the first time. All patients underwent clinical and neuropsychological evaluations (cognitive decline, memory, executive control). Each patient was reevaluated on standard L-dopa therapy. Serial Position Curves showed an increased primacy effect (5.18+/-2.07) and a decreased recency effect (13.35+/-5.51). These findings normalized after L-dopa therapy (3.50+/-1.72 and 16.20+/-3.09 respectively). The effect of L-dopa on working memory is discussed.

Adult↗

L-asparagine depletion and L-asparaginase activity in children with acute lymphoblastic leukemia receiving i.m. or i.v. Erwinia C. or E. coli L-asparaginase as first exposure.

PURPOSE: The present study was aimed at investigating L-asparaginase (L-ASE) activity (in plasma) and L-asparagine (L-ASN) depletion (in plasma and CSF) in children with newly diagnosed acute lymphoblastic leukemia (ALL) exposed for the first time to different L-ASE products. PATIENTS AND METHODS: During the induction treatment of the AIEOP ALL 95 study, 62 patients were treated with either Erwinase (n = 15), or E. coli medac (n = 47) L-ASE products, given either i.m. or i.v., at the standard dosage of 10,000 IU/m2, q 3 days x 8 (first exposure). RESULTS: Plasma and CSF L-ASN trough levels were undetectable in all cases, including those with L-ASE trough activity < 50 mU/ml. L-ASE trough activity during the administration of medac was however significantly higher when compared with that of Erwinase. CONCLUSIONS: L-ASN depletion after a first exposure to standard doses of Erwinase or medac is obtained in virtually all patients. No differences are seen between the I.M. or I.V. administration routes but the medac product is associated with a significantly higher enzyme activity in respect of Erwinase. L-ASN levels may be undetectable also in patients with L-ASE trough activity levels < 50 mU/ml, challenging the current opinion that an activity level of 100 mU/ml is needed to obtain L-ASN depletion.

Antineoplastic Agents↗

Presenile primary cognitive decline or Alzheimer's dementia: 7-year clinical and neuropsychological follow-up.

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: death or untestable condition. This paper concentrates on the main clinical and neuropsychological findings relative to these two 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.

Adult↗

High-performance liquid chromatography tandem mass spectrometry procedure with automated solid phase extraction sample preparation for the quantitative determination of paclitaxel (Taxol) in human plasma.

A sensitive, specific, accurate and reproducible analytical method was developed and validated for the quantitation of the anticancer agent paclitaxel in human plasma. This procedure is based on high performance liquid chromatography/ion spray-tandem mass spectrometry. This methodology is highly specific because a MS/MS technique (multiple reactant-ion monitoring, MRM) was used for both paclitaxel and its internal standard. The use of a fully automated solid phase extraction procedure, using a CN Sep-pak cartridge, to improve the detection limit and quantification limit of paclitaxel in human plasma samples, was evaluated. The method involves the addition of methyl-paclitaxel as internal standard (i.s.). The retention times of paclitaxel and the I.S. were 2.8 and 4.0 min., respectively. The assay was linear over the range 5 to 500 ng/mL, with a quantification limit of 5 ng/mL having a coefficient of variation (c.v.) < 10%. Standard calibration curves, performed on three different days, had correlation coefficients always greater than 0.998. The intra and inter-day precision were within 12%, and accuracy was included in the range 102-110%. Paclitaxel recovery assessed at 15,250 and 500 ng/mL, was determined to be greater than 85%. The assay is applicable to clinical pharmacokinetic studies.

Antineoplastic Agents, Phytogenic↗

MRI of spinal cord involvement in Behçet's disease: case report.

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.

Adult↗

Decreased EEG microstate duration and anteriorisation of the brain electrical fields in mild and moderate dementia of the Alzheimer type.

Spatially oriented segmentation allows researchers to break down the continuous stream of the ongoing EEG into microstates with stable topography of the brain electrical landscapes. The resulting microstates were shown to be related to conscious mental experience as well as to psychiatric disorders typically associated with thought disorders. In the present study, the microstates of the resting EEG of patients presenting with mild or moderate probable dementia of the Alzheimer type (DAT) were investigated. A significant anteriorisation of the centers of gravity of the microstate fields, an increase of the microstates' optimal window size and a reduced duration of sustained microstates were found. These differences were statistically more robust than the typical changes in the frequency domain (diffuse slowing) and were significantly correlated with the cognitive decline. The adaptive spatial segmentation into microstates is discussed as a method to extract meaningful EEG parameters for the early diagnosis and staging of Alzheimer's disease.

Aged↗

Correlations of topographical EEG features with clinical severity in mild and moderate dementia of Alzheimer type.

Quantitative electroencephalography (qEEG) and the Folstein Mini Mental State examination (MMSE) were obtained from 31 patients affected by probable dementia of Alzheimer's type (DAT). qEEG data were examined both by spectral analysis (Fast Fourier Transformation) and by single frequency band topographical centroid, and compared with those of 24 healthy subjects of the same age group. DAT patients were found to have higher absolute power in the slow (delta and theta) frequency bands. Quantitative topographical assessment showed significantly more anteriorly located centers of gravity for the alpha and beta activity. Only alpha anteriorization was correlated with the degree of cognitive impairment as measured by the global deterioration scale and MMSE. It is concluded that quantitative topographical assessment was successful for the statistical handling of the EEG power maps, and to identify a potential parameter for the functional staging of the disease.

Aged↗

Cognitive potentials: ipsilateral corticocortical interconnections in prefrontal human cortex ablations.

The research deals with the possible role of the essentially monosynaptic bidirectional corticocortical connections between occipito-temporo-parietal association cortical areas and frontal areas in the genesis of some contingent negative variation (CNV) components, especially on the supramodal dorsolateral prefrontal regions. With standard and topographic mapping methods of analysis, the multicomponent CNV complex formation was examined in 7 patients with extensive frontal cortex ablations exactly identified through CT/MRI examinations, and in 10 normal subjects. On the scalp over the ablated frontocortical areas, no consistent post-warning auditory N100 a-b-c, P200, P300, early and late CNV components were recordable. The hypothesis is proposed that the bidirectional ipsilateral long-distance pathways which interconnect uni-polymodal occipito-temporo-parietal cortical areas to prefrontal ones, in particular the arcuate-superior longitudinal and superior/inferior occipito-frontal fasciculi, play an important role in the genesis of several CNV complex components, especially the multicomponent post-S1 auditory N100. The posteroanterior sequential latency differences of these neurocognitive components, roughly measured along the scalp or on MRI imagings, is probably accounted for by the transcortical ipsilateral conduction time of about 1 cm/ms (10 m/s).

Brain Mapping↗

Brain electrical activity (quantitative EEG and bit-mapping neurocognitive CNV components), psychometrics and clinical findings in presenile subjects with initial mild cognitive decline or probable Alzheimer-type dementia.

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.

Aged↗

Smooth-pursuit eye movements: alterations in Alzheimer's disease.

Smooth-pursuit eye movements induced by targets moving at constant velocities (from 5 to 100 deg/sec) were recorded from 13 patients with Alzheimer's disease (AD) and from 11 healthy subjects. Four variables were evaluated to quantify the patients' response to the eye movement tests: (1) average peak velocity of smooth-pursuit; (2) percent target matching index after saccade removal (percent ratio between the area of the velocity curve of smooth-pursuit eye movement after saccade removal and the area of target velocity) which is related to the eye performance for each value of target velocity; (3) total amplitude of anticipatory saccades; (4) total number of anticipatory saccades. Compared to the controls, AD patients were found to have significantly lower values of average peak velocity of smooth pursuit and of percent target matching index and a significantly increased number and amplitude of anticipatory saccades. A discriminant stepwise analysis indicated that 5 oculographic variables were significantly associated with the patient's clinical condition (healthy volunteer or AD patient). These statistics yielded an equation for predicting the patient's status according to which the percentage of cases classified correctly was 82.6% in the overall group (n = 23). The predictive performance was similar between the healthy volunteers subgroup (81.8%, n = 11) and the AD subgroup (83.3%, n = 12). The discriminant score was significantly correlated with the score resulting from the MiniMental test (r = 0.67). A significant correlation was also found between the MiniMental score and the number of anticipatory saccades (r = -0.61). No significant correlation was present between the gain of smooth pursuit and the patients' cognitive decline.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

Changes in bit-mapped contingent negative variation (CNV) activity due to initial normal involutional processes of the human brain.

Bit-color mapped multicomponent CNV complexes and RTs to S2 evoked with a simple warned CNV/RT paradigm were recorded and measured in 20 selected right-handed very healthy volunteers (10 young adults and 10 presenile subjects, mean age 28.3 and 59.6, respectively). 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 significantly from the younger group in the auditory post-S1 N1 and early (O-wave) and late (P-wave) CNV complex components. A progressive amplitude reduction limited to frontal leads between O-wave and P-wave, the lowest point being reached in the P-wave, was characteristic in the presenile group. Moreover, presenile subjects showed relatively flat CNV waveshapes of low amplitude and, on the whole, performed a little less well than young ones. This finding suggests that the statistically significant changes in auditory post-S1 N1 and CNV activity recorded in our presenile subjects, without any appreciable deficits in behavioral or mental performance, could be alerting signs of early brain involutional processes related to minimal and subclinical decline in 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 might prove to be of considerable practical importance for clinical research.

Adult↗

Langerhans cell histiocytosis of the spine causing cord compression: case report.

A case of Langerhans cell histiocytosis of the spine causing myeloradiculopathy is reported. Almost complete regression of symptoms and signs was observed in the patient after surgical treatment and radiotherapy. The clinical and histological features of the disease are discussed. The literature dealing with the previously reported cases of spinal histiocytosis involving neural structures is reviewed.

Adult↗

Effects of acute valproic acid administration on carnitine plasma concentrations in epileptic patients.

Serial plasma samples collected after an acute administration of valproic acid, (VPA, 15 mg/kg as oral solution) in epileptic patients were selected for this study. The plasma samples were selected from three different groups of patients; patients on phenobarbital and phenytoin with clinical VPA intolerance (group A); patients on phenobarbital and phenytoin without clinical VPA toxicity (group B); and patients without phenobarbital and phenytoin and without clinical VPA toxicity (group C). Plasma samples from 6 patients per group were analyzed for carnitines and ammonia. Ammonia levels during acute study increased significantly (P less than 0.05) in patients who experienced VPA intolerance, while no changes were found in the other patients. After acute VPA administration, total carnitine was unchanged but free carnitine was decreased (P less than 0.05) and carnitine esters were increased (P less than 0.05) in all groups of patients studied. No difference in carnitine profiles was seen between patients with or without evidence of VPA administration has an important effect on carnitine metabolism. However, unlike the acute effect on ammonia metabolism, this acute effect does not seem to be correlated with any associated antiepileptic therapy, nor does it predict clinical VPA intolerance.

Adult↗

Topographic CNV activity mapping, presenile mild primary cognitive decline and Alzheimer-type dementia.

The CNV complex evoked with a standard paradigm (S1-2 sec-S2-motor response) and reaction time (RT) to the imperative signal (S2) were recorded and measured in 12 patients with initial presenile idiopathic cognitive decline (PICD), 12 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 variations (PINV) were observed in the majority of patients with PAD. These results suggest that similar CNV complex and RT changes to those observed in our patients may constitute a valuable clue in the study of pathophysiological brain functioning in the early stages of presenile idiopathic mental deterioration.

Aged↗

Effect of physiological and pathological aging processes on topographic bit-mapped cognitive evoked potentials in presenile subjects.

Bit-mapped multicomponent CNV complex and reaction time (RT) were recorded and measured in 24 presenile patients with initial symptoms of very mild to moderately severe primary mental deterioration without depression, and in 10 age-matched controls. All patients underwent CT and MRI examinations, EEG spectral analysis and a battery of psychometric test. Significant group differences were obtained for measures of some post-S1 ERP and CNV components, particularly of the post-S1 N1b, P300 and early and late pre-S2 CNV. P300 with increased latency, no significant CNV activity, very prolonged RTs, EEG slowing down and diffuse brain atrophy were observed in the majority of patients with probable presenile Alzheimer's dementia. These results suggest that CNV/RT and EEG activity changes similar to those observed in our patients may constitute a valuable clue for the study of brain dysfunction in the early stage of presenile idiopathic cognitive impairment.

Aged↗

Cognitive event-related potentials and reaction time in presenile subjects with initial mild cognitive decline or probable Alzheimer-type dementia.

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.

Aged↗