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Biomedical subjects

M Guazzelli

Publications and source records attributed to M Guazzelli.

At least 19 recordsLinked to original sources
PubMed2006

Alcohol consumption and heavy drinking: a survey in three Italian villages.

AIMS: We investigated drinking habits, and heavy and problem drinking prevalence in a sample of individuals attending the consulting rooms of local General Practitioners in three Italian villages. METHODS: The samples were selected to be representative of the entire population of the three villages. Information on alcohol-drinking patterns was collected using a questionnaire that included a masked form of the CAGE rating scale. According to the frequency of alcohol intake, subjects were grouped in three categories: abstainers, occasional drinkers, and daily drinkers. In agreement with WHO guidelines, 40 g/day for males and 20 g/day for females were taken as cut-off for 'heavy drinking' and consumptions of > 80 g/day for males and 40 g/day for females were used to define 'problem drinking'. RESULTS: A total of 2972 individuals were included in the survey (19% of the population). Of these, 44% were abstinent, 20% occasional drinkers, and 36% daily drinkers. Daily drinking was found to be more common in males than in females but heavy drinking was significantly higher in females compared with males (P > or = 0.0001). The problem drinkers were 12% of the entire population and the CAGE-positive subjects (> or = 2 positive answers) were 3.5%. CONCLUSIONS: Our data indicate that alcohol drinking is widely diffused in the three communities. A large layer of the population drinks above the WHO-established cut-off. The incidence of heavy and problem drinking seems to have significant gender and regional differences that are important to consider when planning effective prevention programmes.

Adolescent↗
PubMed2005

Slow wave and rem sleep mechanisms are differently altered in hereditary pick disease associated with the TAU G389R mutation.

Sleep disturbances are found in the course of most dementing syndromes. We report a longitudinal polysomnographic and 18FDG-PET study in a 38-year-old male with FTDP17 carrying the Tau gene mutation G389R. All-night sleep EEG and wake cerebral glucose metabolism at rest (eyes/ears covered) of the preceding day were studied twice, eight months (Night 1; PET 1) and sixteen months (Night 2; PET 2) after the initial neurological evaluation. The Night 1 study showed sleep fragmentation associated to a short REM latency and a severe reduction of slow wave sleep, with relatively preserved NREM-REM sleep cycles; daytime PET 1 revealed severe cerebral glucose metabolic reductions in frontal and temporal areas, with relative preservation of remaining cortical regions and subcortical structures. On Night 2, the total sleep time was less than 5 hours, delta sleep and REM latency remained shortened and only two sleep cycles could be identified; daytime PET 2 exam revealed a greater cortical metabolic impairment and an involvement of subcortical brain regions as compared to PET 1. Post-mortem neuropathological data showed severe neuronal loss, spongiosis and gliosis that were mostly marked in cortical layers I, II, V and VI. In vivo, neurometabolic and post-mortem neuropathological data are consistent with and indicative of a severe dysfunction of intra- and trans-hemispheric regional connectivity and of cortico-thalamic circuits. These findings suggest that the decreased cortical and subcortical connectivity may have been the main pathophysiological mechanism responsible for delta sleep reduction and the cognitive decline.

Adult↗
PubMed2004

Influence of mental motor imagery on the execution of a finger-to-thumb opposition task.

The present fMRI study compares regional distribution of the cortical activity during the execution of unilateral hand movements (finger-to-thumb opposition) preceded or not by their motor simulation (S + E and E condition, respectively). The results show that, overall, the number and the spatial distribution of activated voxels are both increased in the S + E with respect to the E condition. The motor performance preceded by mental rehearsal is related to selective increase of the cortical activity. Among the motor areas that are found active during the simple motor execution a significant enhancement of functional activation during the S + E condition ipsilateral primary motor regions (M1). The activity increase may be accounted by a sort of neural recruiting that is made possible by the overlapping of cortical networks involved in both motor output and motor imagery. The beneficial effects of "mental practice" on the physical performance may rely to the close temporal association between motor rehearsal and actual performance.

Adult↗
PubMed2004

Sensory-motor cortex activity modulation by hypnotic susceptibility and hypnosis during finger movement.

The aim of the experiment was to study whether the activity of the primary sensory-motor (S1/M1), supplementary motor (SMA) and pre-motor (PMA) areas during fingers movement is modulated by hypnotic susceptibility and hypnosis. Cortical activity was studied through functional Magnetic Resonance Imaging (fMRI) during a finger-to-thumb opposition task in awake (Highs) and hypnotized highly susceptible (H-Highs) as well as in awake non susceptible subjects (Lows). Results did not show any significant difference in sensory-motor areas activation between Highs and Lows (trait effect) and between Highs and H-Highs (state effect). The activation in 3 subjects among Highs and only 1 among Lows (out of 5) of the caudal S1, receiving the most part of the cutaneous input, appears noteworthy and prompts further investigation on possible hypnotizability-related differences in sensory-motor integration.

Adult↗
PubMed2000

The neurometabolic landscape of cognitive decline: in vivo studies with positron emission tomography in Alzheimer's disease.

Alzheimer's disease, the most common form of dementia in the elderly, is characterized by the progressive, global and irreversible deterioration of cognitive abilities. The development of positron emission tomography (PET) methodologies has made it possible to study the in vivo brain metabolic correlates of human cognitive and behavioral functions. Moreover, as PET scan examinations can be repeated, the progression of the neuropathological process and its relation to cognitive dysfunction can be followed over time. In an effort to understand the changes in neural function that precede and accompany onset of dementia and their relation to clinical manifestations, in the last several years, we have conducted clinical, neuropsychological and brain metabolic studies in groups of Alzheimer's disease patients at different stages of dementia severity or with distinct clinical pictures and in populations at risk for developing the disease. Here, we discuss the main findings and implications obtained from these studies.

Alzheimer Disease↗
PubMed2000

Is ESES/CSWS a strictly age-related disorder?

OBJECTIVES: We report on a case of ESES/CSWS observed in a patient of 21 years and still persisting at the age of 25. Cases of ESES/CSWS have never been previously described in adult patients. ESES/CSWS is considered to be related to the degree of maturation of the central nervous system, and therefore strictly age-related. METHODS: Our case of ESES/CSWS was observed in a 2 1 year old woman referred for cognitive and behavioral disorders. She had previously had epileptic fits, but was seizure free at that time. The patient underwent a full-night polygraphic recording , which showed typical ESES/CSWS pattern, with a Spike-and-Wave Index >8 5%. Polysomnography was repeated 9 times in a 4 year follow-up, during which the ESES/CSWS condition persisted, despite the pharmacological treatments. The patient also underwent cerebral magnetic resonance imaging and fludeoxyglucose F 18 positron emission tomography (PET). RESULTS: The PET study revealed reduced metabolic activity within the lower gyrus of the right parietal lobe, but no significant difference between subcortical structures and cortical mantle was seen. MRI scans were normal. CONCLUSIONS: This observation suggests that ESES/CSWS might not always be an age-related condition. Sleep EEG recordings should always be performed in patients with behavioral disorders and a history of epileptic fits.

Adult↗
PubMed2000

Increased remission rates with venlafaxine compared with fluoxetine in hospitalized patients with major depression and melancholia.

This was a 6-week, double-blind, randomized trial of the efficacy and tolerability of venlafaxine and fluoxetine in 109 patients with major depression and melancholia. Hospitalized and day care patients with DSM-IV major depression and melancholia and a baseline Montgomery-Asberg Depression Rating Scale (MADRS) score of > or = 25 were eligible. The doses were venlafaxine 75 mg/day or fluoxetine 20 mg/day from days 1-4, venlafaxine 150 mg/day or fluoxetine 40 mg/day from days 5-10, and venlafaxine 225 mg/day or fluoxetine 60 mg/day from days 11-42. The intention-to-treat analyses included 55 patients on venlafaxine and 54 on fluoxetine. At the final evaluation, 70% of patients with venlafaxine and 66% with fluoxetine had > or = 50% reduction in the MADRS score, and 70% with venlafaxine and 62% with fluoxetine had a Clinical Global Impression (CGI) score of 1 or 2. A CGI improvement score of 1 was observed in 51% of patients with venlafaxine and 32% with fluoxetine (P = 0.018). A final Hamilton Depression Rating Scale (HAM-D) score < 7 was attained in 41% of venlafaxine-treated and 36% of fluoxetine-treated patients. Overall, 22% of patients in each group discontinued therapy, but only 5% on venlafaxine and 9% on fluoxetine discontinued for adverse events. Nausea was reported in 5.5% of venlafaxine-treated patients and 14.8% of fluoxetine-treated patients. Venlafaxine was effective and well tolerated for treating inpatients with major depression and melancholia. Based on remission criteria (HAM-D < 7 or CGI of 1), venlafaxine was superior to fluoxetine.

Adolescent↗
PubMed2000

Neural correlates of imaginal aggressive behavior assessed by positron emission tomography in healthy subjects.

OBJECTIVE: Neurodegenerative or traumatic lesions of the frontal lobes often lead to abnormally aggressive behavior. The authors hypothesized that the imaginal evoking of scenarios involving aggressive behavior would be associated with a modulation of the functional activity in the human frontal cortex. METHOD: Regional cerebral blood flow (rCBF) determinations by positron emission tomography and psychophysiological measures of emotional responsivity were obtained in a group of 15 young healthy volunteers with good visual imagery abilities and no history of abnormal behavior while they imagined the same scenario with four variations involving emotionally neutral behavior and aggressive behavior. RESULTS: Compared to the imagined neutral scenario, the imagined scenarios involving aggressive behavior were associated with significant emotional reactivity and rCBF reductions in the ventromedial prefrontal cortex, suggesting that a functional deactivation of this cortical area occurs when individuals respond to the eliciting of imagined aggressive behavior. CONCLUSIONS: These results in healthy subjects further expand previous findings from animal and human studies by providing an in vivo functional demonstration of the involvement of the orbitofrontal cortex in the expression of aggressive behavior. They are also consistent with the hypothesis that a functional alteration of this cortical region may be present in individuals with pathological aggressive behavior.

Adult↗
PubMed2000

Cerebral metabolic response to passive audiovisual stimulation in patients with Alzheimer's disease and healthy volunteers assessed by PET.

UNLABELLED: Alzheimer's disease is associated with reductions in resting-state brain metabolism, as measured by PET, progressing with dementia severity. The purpose of this study was to see to what extent brain regions with reduced resting-state metabolic rates in Alzheimer patients could be activated by a passive audiovisual stimulation test and to compare the result with activation in age-matched healthy volunteers. The extent of activation in Alzheimer's disease is considered to reflect the integrity of synaptic function, or inherent viability, and the potential responsiveness of the Alzheimer brain to drug therapy. METHODS: Regional cerebral metabolic rates for glucose (rCMRglc, in mg/ 100 g tissue/min) were measured in the resting state (eyes and ears covered) and during passive audiovisual stimulation (watching a movie) in 15 otherwise healthy Alzheimer patients of differing dementia severity (Mattis Dementia Rating Scale score, 23-128) and in 14 age-matched healthy volunteers (score, 141 +/- 3) using PET with 2 sequential injections of FDG. RESULTS: In the volunteers, audiovisual stimulation caused significant rCMRglc increases in visual and auditory cortical areas but significant decreases in frontal areas. In the mildly demented patients, rCMRglc responses were within 2 SDs of the mean in volunteers. However, the magnitude of the rCMRglc responses during stimulation declined significantly with dementia severity in the right occipitotemporal, right and left occipital association, and left calcarine cortical regions. CONCLUSION: Functional brain responsiveness, evaluated by a passive audiovisual stimulation paradigm with PET, is within normal limits in mildly demented Alzheimer patients but fails with worsening dementia severity. Declining responsiveness may account for the limited success of neurotransmitter replacement therapy in Alzheimer patients with moderate-to-severe dementia.

Acoustic Stimulation↗
PubMed1999

Psychiatric comorbidity and psychosocial stress in patients with tension-type headache from headache centers in Italy. The Italian Collaborative Group for the Study of Psychopathological Factors in Primary Headaches.

A multicenter study was carried out in 10 Italian Headache Centers to investigate the prevalence of psychosocial stress and psychiatric disorders listed by the IHS classification as the "most likely causative factors" of tension-type headache (TTH). Two hundred and seventeen TTH adult outpatients consecutively recruited underwent a structured psychiatric interview (CIDI-c). The assessment of psychosocial stress events was carried out using an ad hoc questionnaire. The psychiatric disorders that we included in the three psychiatric items of the fourth digit of the IHS classification were depressive disorders for the item depression, anxiety disorders for the item anxiety, and somatoform disorders for the item headache as a delusion or an idea. Diagnoses were made according to DSM-III-R criteria. At least one psychosocial stress event or a psychiatric disorder was detected in 84.8% of the patients. Prevalence of psychiatric comorbidity was 52.5% for anxiety, 36.4% for depression, and 21.7% for headache as a delusion or an idea. Psychosocial stress was found in 29.5% of the patients and did not differ between patients with and without psychiatric comorbidity. Generalized anxiety disorder (83.3%) and dysthymia (45.6%) were the most frequent disorders within their respective psychiatric group. The high prevalence of psychiatric disorders observed in this wide sample of patients emphasizes the need for a systematic investigation of psychiatric comorbidity aimed at a more comprehensive and appropriate clinical management of TTH patients.

Adult↗
PubMed1999

Tau gene mutation G389R causes a tauopathy with abundant pick body-like inclusions and axonal deposits.

Exonic and intronic mutations in Tau cause familial neurodegenerative syndromes characterized by frontotemporal dementia and dysfunction of multiple cortical and subcortical circuits. Here we describe a G389R mutation in exon 13 of Tau. When 38 years old, the proband presented with progressive aphasia and memory disturbance, followed by apathy, indifference, and hyperphagia. Repeated magnetic resonance imaging showed the dramatic progression of cerebral atrophy. Positron emission tomography revealed marked glucose hypometabolism that was most severe in left frontal, temporal, and parietal cortical regions. Rigidity, pyramidal signs and profound dementia progressed until death at 43 years of age. A paternal uncle, who had died at 43 years of age, had presented with similar symptoms. The proband's brain showed numerous tau-immunoreactive Pick body-like inclusions in the neocortex and the fascia dentata of the hippocampus. In addition, large numbers of tau-positive filamentous inclusions were present in axons in the frontal, temporal, and parietal lobes. Immunoblot analysis of sarkosyl-insoluble tau showed 2 major bands of 60 and 64 kDa. Upon dephosphorylation, these bands resolved into 4 bands consisting of three- and four-repeat tau isoforms. Most isolated tau filaments were straight and resembled filaments found in Alzheimer disease and some frontotemporal dementias with tau mutations. A smaller number of twisted filaments was also observed. Biochemically, recombinant tau proteins with the G389R mutation showed a reduced ability to promote microtubule assembly, suggesting that this may be the primary effect of the mutation. Taken together, the present findings indicate that the G389R mutation in Tau can cause a dementing condition that closely resembles Pick's disease.

Adult↗
PubMed1999

Association between brain functional failure and dementia severity in Alzheimer's disease: resting versus stimulation PET study.

OBJECTIVE: This study tested the hypothesis that regional cerebral glucose metabolism during neuronal activation is a more sensitive index of neuronal dysfunction and clinical severity in Alzheimer's disease than is glucose metabolism at rest. METHOD: The subjects were 15 Alzheimer's disease patients with a wide range of Mattis Dementia Rating Scale scores (23-128). By using positron emission tomography, absolute glucose metabolism was measured in the parietal, occipital (visual areas), and temporal (auditory areas) cortical regions during rest (eyes/ears covered) and audiovisual stimulation. RESULTS: In the parietal cortex, glucose metabolism correlated with dementia severity in both conditions. In contrast, in the relatively preserved visual and auditory cortical regions, glucose metabolism predicted dementia severity during stimulation but not at rest. CONCLUSIONS: These findings suggest that regional cerebral glucose metabolism during stimulation is a more sensitive index of the functional/metabolic failure of neuronal systems than is metabolism at rest.

Acoustic Stimulation↗
PubMed1999

Schizophrenia--a disorder of the corollary discharge systems that integrate the motor systems of thought with the sensory systems of consciousness.

BACKGROUND: In spite of intensive research, no causal anatomical lesion has been found in schizophrenia. It may instead be caused by malfunctioning circuits in the corollary discharge, feed forward (CD-FF) systems of thought. AIMS: To integrate with the CD-FF hypothesis recent data showing that subcortical motor systems participate in thinking. METHODS: We review CD-FF concepts in relation to recent evidence that 'motor' brain structures participate in cognitive processing. RESULTS: Malfunctioning of CD-FF systems that integrate thinking and consciousness could produce auditory hallucinations, delusions and disorganised thought. CONCLUSIONS: We hypothesise that the pathophysiology of schizophrenia lies in integrative circuits of basal ganglia, thalamus and frontal cortex. Fruitful research directions would include elucidation of CD-FF circuits at even higher brain levels, the behaviour of these circuits during dreaming, and their responses to late maturational events including synaptic elimination.

Cognition Disorders↗
PubMed1995

EEG, PET, SPET and MRI in intractable childhood epilepsies: possible surgical correlations.

Magnetic resonance imaging (MRI), single photon emission tomography (SPET), and positron emission tomography (PET) using [18F]fluorodeoxyglucose were used in combination with scalp and scalp-video EEGs in a group of 30 pediatric patients with drug resistant epilepsy (DRE) in order to identify patients who could benefit from neurosurgical approach. Seizures were classified according to the consensus criteria of The International League Against Epilepsy. In three patients infantile spasms (IS) were diagnosed; 13 subjects were affected by different types of generalized seizures, associated with complex partial seizures (CPS) in three. In the other 14 patients partial seizures, either simple (SPS) or complex, were present. A localized abnormality was demonstrated in one patient with IS and in three patients with generalized seizures. Of the group of 14 subjects with CPS, MRI and CT were normal in 7, but SPET or PET indicated focal hypoperfusion or hypometabolism concordant with the localization of the EEG abnormalities. In 5 of the other 7 patients anatomical and functional imaging and EEG findings were concordant for a localized abnormality. It can be concluded that functional imaging combined with scalp EEGs appears to be superior to the use of only CT and MRI for selecting children with epilepsy in whom a surgical approach can be considered, in particular when CPS resistant to therapy are present.

Brain↗
PubMed1995

Effect of L-propionyl carnitine on some properties of erythrocytes and leukocytes of alcohol abusers.

The effect of L-propionyl carnitine, the carnitine derivative utilized as a more effective drug for membrane protection, on Na-K ATPase activity of erythrocyte ghosts of alcohol-dependent patients and blood donors has been investigated. The effect of L-propionyl carnitine on leukocyte chemotaxis and cytochrome c reduction, a measure of superoxide ion production was also studied. It has been in fact observed that alcohol is immunotoxic on both the non-specific and the specific immune response. In alcohol-dependent erythrocytes, a significant higher value of the 1H-NMR spin lattice relaxation time (T1) was observed as compared to blood-donor erythrocytes. The in-vitro addition of ethanol increases the T1 values of blood donor erythrocytes, whereas it is without effect on the T1 value of alcohol-dependent erythrocytes. The Na-K ATPase activity is higher in alcohol-dependent erythrocyte ghosts as compared to blood-donor ghosts. A non-significant increase of the Na-K ATPase activity of blood-donor ghosts was observed with the increasing of L-propionyl carnitine concentrations (from 0.2 to 5.0 mM), whereas the Na-K ATPase activity of alcohol-dependent ghosts decreases. From these combined effects the differences of Na-K ATPase activity progressively decrease with the increasing of L-propionyl carnitine concentration, and no significant differences are observed between the two groups at L-propionyl carnitine concentrations higher than 0.5 mM. The in-vitro addition of ethanol increases the enzyme activity to a greater extent in blood-donor ghosts as compared to alcohol-dependent ghosts. This in-vitro activation by ethanol is decreased by the addition of L-propionyl carnitine. The chemotaxis induced by N-formyl-methionyl-leucylphenylalanine and the superoxide anion production stimulated by zymosan is significantly lower in alcohol-dependent neutrophils. L-Propionyl carnitine increases, in a dose-dependent way, both chemotaxis and superoxide anion production of alcohol-dependent neutrophils, and no significant difference was observed between the two groups at 5 mM L-propionyl carnitine. These experimental results suggest that L-propionyl carnitine administration may be useful for reducing some acute and chronic damages due to alcohol ingestion. The protective and modulatory actions of L-propionyl carnitine may be even more evident in cells and tissues different from those investigated in this study and in which ethanol determines several biochemical damages.

Alcoholism↗