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P Campo

Publications and source records attributed to P Campo.

At least 19 recordsLinked to original sources
PubMed2006

Effects of cholinergic drugs and cognitive training on dementia: 2-year follow-up.

Several studies have shown that pharmacological and cognitive treatments for Alzheimers's disease improve cognitive function for short periods, but fewer studies have evaluated the efficacy of those treatments for longer (2-year) periods. An initial sample of 68 subjects with mild Alzheimer's disease underwent clinical and cognitive evaluation. After evaluation, subjects were assigned to four different groups and participated in a 2-year follow-up study. Group 1 (n = 14) received combined drug and cognitive stimulation, group 2 (n = 20) received only drug treatment, group 3 (n = 14) received only cognitive stimulation, and group 4 (n = 30) received no treatment at all. Results confirmed previous investigation, cognitive and combined stimulation improved patients' performance throughout the 1st year; however, all groups deteriorated gradually throughout the 2nd year of treatment. According to this evidence, it can be concluded that we cannot stop cognitive deterioration after 2 years of treatment, although deterioration is greater and its progress faster in patients not receiving any treatment at all.

Aged↗
PubMed2005

Evidence of biochemical and biomagnetic interactions in Alzheimer's disease: an MEG and MR spectroscopy study.

BACKGROUND: Several neuroimaging studies have shown reliable differences between Alzheimer's disease (AD) patients and age-matched controls. However, few studies have demonstrated the interactions between neuroimaging methods for the diagnoses of AD. OBJECTIVE: In this study, we try to elucidate the complementary nature of magnetoencephalography (MEG) and magnetic resonance spectroscopy (MRS) examinations in the assessmentof AD. METHODS: Ten patients fulfilling the NINCDS-ADRDA criteria of probable AD, and 10 elderly individuals with no history of neurological or psychiatric illness serving as age-matched controls participated in the study. All patients and controls received an MRS, MEG and neuropsychological assessment. MEG data were obtained in the context of a working memory task, previously utilized in a similar sample of patients. RESULTS: The AD group showed a reduced number of activity sources over left temporoparietal areas during the late portion of the evoked magnetic field (between 400-800 ms), as well as a bilateral temporoparietal increase in creatine and myoinositol concentrations, and in the myoinositol/N-acetyl-aspartate ratio. The combination of the variables 'number of dipoles during the late portion of the evoked magnetic field' and 'myoinositol/N-acetyl-aspartate ratio' accounted for 65% of the variance of the Mini Mental State Examination scores. CONCLUSIONS: These results highlight the importance of assessing the complex brain pathology underlying AD by utilizing multiple brain examination modalities in a coordinate approach.

Aged↗
PubMed2005

Medial temporal lobe neuromagnetic hypoactivation and risk for developing cognitive decline in elderly population: a 2-year follow-up study.

Cognition declines as a function of age. However, some elders could develop more severe status such as mild cognitive impairment (MCI). The aim of this study was the early detection of neurophysiological patterns of brain activity that may predict the possibility of certain subjects to develop MCI. Brain magnetic activity was recorded from 15 healthy subjects during a memory task by means of magnetoencephalography. None of the participants could be considered as MCI at the time of the first clinical evaluation. After 2-year follow-up, five subjects developed MCI and 10 maintained their cognitive status across time. The subjects who developed cognitive decline showed a lower number of activity sources in the left medial temporal lobe between 400 and 800 ms after stimulus onset, as compared to the non-cognitive decline group. These findings may help with the early identification of elderly subjects at high risk of cognitive decline, allowing the possibility of neuropsychological or pharmaceutical treatment that delay or prevent the progression of the cognitive impairment.

Age Factors↗
PubMed2005

[Recent contributions from magnetoencephalography to the neurobiology of attention-deficit/hyperactivity disorder].

INTRODUCTION AND DEVELOPMENT: Current theories postulate that the core cognitive deficit in attention-deficit/hyperactivity disorder (ADHD) is an executive dysfunction. Neuroimaging studies on the whole have provided both anatomical and functional evidence supporting the fronto-striatal dysfunction hypothesis in ADHD. However, recent neuroimaging studies have found anatomical and functional impairments in posterior cortical regions, such as the inferior parietal and posterior temporal cortices, which have been related to a deficit in selective attention. Event related potential (ERP) studies show that ADHD children have an impairment in early components (within the first 200 ms of processing), such as P1 or N1, both of which are sensitive to selective attention effects. These findings cast doubt regarding the fronto-striatal/executive dysfunction as the core deficit in ADHD. CONCLUSIONS: One of the main objectives of ADHD research is the search for its core cognitive deficit and the neural networks underlying it, because it has important repercussions over ADHD diagnosis and treatment. High temporal resolution techniques, such as ERP or magnetoencephalography may be particularly useful in distinguishing the precise moment of cognitive processing during which the brain activity of children with ADHD begins to be impaired. As a consequence, this may help to elucidate the core cognitive deficit in ADHD.

Attention Deficit Disorder with Hyperactivity↗
PubMed2004

Effects of cholinergic drugs and cognitive training on dementia.

A study was performed on patients with Alzheimer's disease (AD) in order to evaluate the efficacy of a combined treatment (donepezil plus cognitive training) in both cognitive processes and affective states. Eighty-six subjects, 25 men and 61 women, with an average age of 75.58 years, were studied. Almost all the subjects had a basic educational level. Donezepil was administered at a dose of 10 mg daily along with cognitive treatment involving images of everyday life and reminiscent music; the sessions took place on Monday to Friday and lasted three quarters of an hour. The study lasted 12 months. Subjects underwent test-retest with the following tests: Mini-Mental State Examination (MMSE), the cognitive subscale of the Alzheimer's Disease Assessment Scale (ADAS-cog); the Geriatric Depression Scale (GDS) and the overall deterioration scale (FAST). The results showed that subjects receiving the combined treatment had a better response than those who did not receive any cognitive training. These subjects' MMSE score decreased by 3.24 on average. The affective symptomatology of those receiving only drug treatment improved whereas the cognitive processes did not.

Aged↗
PubMed2004

Profiles of brain magnetic activity during a memory task in patients with Alzheimer's disease and in non-demented elderly subjects, with or without depression.

The presence of depression is common among the elderly and it often complicates the early diagnosis of Alzheimer's disease (AD). In this study, we searched for brain activity measures that characterise AD. We compared brain magnetic activity profiles during a memory task, obtained from patients with AD, elderly patients with late onset depression, and age matched volunteers without history of neurological or psychiatric disease. AD patients showed significantly reduced activity in left temporal lobe regions during late portions of the event related magnetic response (400 ms or later after stimulus onset), compared with both groups of patients who did not present with serious cognitive decline. This finding highlights the potential usefulness of MEG protocols supporting the differential diagnosis of AD and major depression related cognitive decline in the elderly.

Age of Onset↗
PubMed2004

[The neurofunctional foundation of cognitive rigidity in attention deficit hyperactivity disorder: some preliminary findings].

INTRODUCTION: It has been proposed that there is an impairment in cognitive flexibility in children with attention deficit hyperactivity disorder (ADHD). The Wisconsin card sorting test (WCST) is the most widely used neuropsychological test for assessing this process. Previous studies have reported the presence of a subgroup of children with ADHD which has a low cognitive flexibility. In addition this subgroup showed a high resistance to the treatment with stimulant medication. OBJECTIVES: The aim of this study was to examine whether there were different patterns of brain magnetic activity in different subgroups of ADHD, during the performance of a cognitive flexibility task, such as WCST. PATIENTS AND METHODS: We recruited a sample of 18 children, divided into three groups according to DSM IV R diagnostic criteria. Here we present preliminary data based on a subsample of nine children. Brain magnetic activity was registered while the children performed the WCST by means of Magnetoencephalography (MEG). This is a non invasive neuroimaging technique with a high spatio temporal resolution. RESULTS: Preliminary results showed that ADHD mixed group had a higher rate of perseverative responses. In addition, a different pattern of brain magnetic activity was noted in this group, showing less activation in anterior cingulate cortex and dorsolateral prefrontal cortex in the left hemisphere during the first 400 ms. CONCLUSIONS: MEG seems to be an useful tool to describe the brain network that subserves cognitive flexibility in different groups of children. It could have important repercussions in the classification of ADHD, both neuropsychologically and pharmacologically.

Attention Deficit Disorder with Hyperactivity↗
PubMed2003

[Neuromagnetic correlates of dyslexia].

Dyslexia was first described over a century ago and since then many theories have been put forward to explain it, but we still do not have one single unified theory that explains the problem. Furthermore, over the years a great deal of research work has also been carried out that relates dyslexia with disorders in different brain structures, and yet we still do not have a clear idea of exactly which neurophysiological mechanisms are involved. It has been claimed, however, that the disorder may be caused by specific deficits in the left frontotemporal region or atypical asymmetries in the left perisylvian regions. Lastly, neuroimaging techniques, such as functional magnetic resonance or mapping of the electrical activity in the brain, have helped to further studies into dyslexia over the last decade. Recently, the introduction of magnetoencephalography in the study of the brain has opened up a whole new range of possibilities that will allow most of the controversial points raised by research into dyslexia using neuroimaging techniques to be resolved empirically.

Child↗
PubMed2003

[The neuromagnetic correlates of language].

Studies of language using different functional neuroimaging techniques have shown the cortical structures to be involved in the functions of language, both in control subjects and in patients with different neurological pathologies who are to undergo brain surgery. Magnetoencephalography (MEG) is a totally non-invasive technique that measures the magnetic fields generated by the flow of intracellular current produced in the dendrites of the pyramidal neurones. MEG also offers the possibility of lateralizing language, so enabling us to know which areas of language lie within the dominant hemisphere and to establish the temporal patterns that reveal the organisation, either in sequence or in parallel, of the different areas that are activated. This will provide us with a deeper understanding of the physiological foundations upholding both language and other cognitive processes.

Adult↗
PubMed2001

Styrene-induced hearing loss: a membrane insult.

Styrene is an aromatic solvent widely used as a precursor for polystyrene plastics in many factories which produce glass-reinforced plastic. This solvent has been shown to disrupt the auditory system in both humans and animals. In order to study the sequence of events which could explain the cochlear impairments, a time course experiment was carried out with 6-month-old rats. Male Long Evans rats were exposed to 1000 ppm styrene for 6 h/day, 5 days/week, for either 1, 2, 3, or 4 consecutive weeks. Auditory function was tested by recording the near field evoked potentials from the inferior colliculus, and histological analyses of the cochleae were performed with light and transmission electron microscopy. The electrophysiological results support a toxic mid-frequency process which keeps worsening even after the end of the exposure. The histological findings demonstrate that supporting cells are the first targets of the solvent. Then, the outer hair cells of the third row (OHC3) are disrupted, followed successively by OHC2 and OHC1 from the basal (20 kHz) to the upper turn (4 kHz) of the cochlea. Basically, the disorganization of the membranous structures could be the starting point for the cochlear injury induced by styrene. This paper presents a hypothesis that the accumulation of K+ in the spaces of Nuel underlies the toxic effects of styrene.

Animals↗
PubMed2000

High frequency of hypermutable Pseudomonas aeruginosa in cystic fibrosis lung infection.

The lungs of cystic fibrosis (CF) patients are chronically infected for years by one or a few lineages of Pseudomonas aeruginosa. These bacterial populations adapt to the highly compartmentalized and anatomically deteriorating lung environment of CF patients, as well as to the challenges of the immune defenses and antibiotic therapy. These selective conditions are precisely those that recent theoretical studies predict for the evolution of mechanisms that augment the rate of variation. Determination of spontaneous mutation rates in 128 P. aeruginosa isolates from 30 CF patients revealed that 36% of the patients were colonized by a hypermutable (mutator) strain that persisted for years in most patients. Mutator strains were not found in 75 non-CF patients acutely infected with P. aeruginosa. This investigation also reveals a link between high mutation rates in vivo and the evolution of antibiotic resistance.

Adaptation, Physiological↗
PubMed2000

Combined effects of exposure to styrene and ethanol on the auditory function in the rat.

In order to study the auditory effects of a metabolic interaction between ethanol and styrene, a first group of rats was gavaged once a day with ethanol (4 g/kg), a second group was exposed to 750 ppm styrene by inhalation, and a third group was exposed to both ethanol and styrene (5 days/week, 4 weeks). Auditory function was tested by recording brainstem (inferior colliculus) auditory evoked potentials, and cochlear hair cell loss was estimated by light microscopy. Cytochrome P450 2E1 and the main urinary styrene metabolites, namely mandelic, phenylglyoxylic and hippuric acids, were measured by high-performance liquid chromatography to check the effects of ethanol on styrene metabolism. In our experimental conditions, ethanol alone did not have any effect on auditory sensitivity, whereas styrene alone caused permanent threshold shifts and outer hair cell damage. Hearing and outer hair cell losses were larger after the exposure to both ethanol and styrene than those induced by styrene alone, indicating a clear potentiation of styrene ototoxicity by ethanol. As expected, metabolic data showed that ethanol alters styrene metabolism and can therefore be considered a modifying factor of styrene toxicokinetics.

Administration, Inhalation↗
PubMed2000

Combined effects of noise and styrene exposure on hearing function in the rat.

Combined exposure to both noise and aromatic solvents such as styrene is common in many industries. In order to study the combined effects of simultaneous exposure to both noise and styrene on hearing, male adult Long-Evans rats were exposed either to 750 ppm styrene alone, to a 97 dB SPL octave band of noise centered at 8 kHz, or to a combination of noise and styrene. The exposure duration was 6 h/day, 5 days/week, for 4 consecutive weeks. Auditory function was tested over a frequency range from 2 to 32 kHz by recording near field potentials from the inferior colliculus, whereas histopathological analyses of the cochleae were performed with conventional morphometric approaches. Whereas both noise and styrene each caused permanent threshold shifts, the mechanisms of cochlear damage were different. Noise-induced hearing loss was mainly related to injuries of the stereocilia, whereas styrene-induced hearing loss was related to outer hair cell losses. Following the combined exposure, the threshold elevations as well as the cell losses exceeded the summed loss caused by noise and by styrene alone in the range of 8-16 kHz. Therefore, these results suggest that the two ototoxicants can cause a permanent synergistic loss of auditory sensitivity.

Animals↗
PubMed2000

Development of two spanish versions of the verbal selective reminding test.

The Selective Reminding procedure has become a widely used test for evaluating verbal learning and memory. However, since this test was mainly devised for use in English speaking individuals, disadvantages could appear when translations of the test are applied to Spanish speaking patients. To overcome these difficulties, two Spanish versions of the Verbal Selective Reminding Test were devised and administered to 48 healthy individuals, 19-31 years in age, in two separate sessions. We found that performances on the two forms were comparable, except for one measure. All the variables on both forms yielded significant positive correlations. We also examined test-retest reliability separately for both possible orders, with Order 2 (Form 2 administered first) being more reliable than Order 1 (Form 1 administered first).

Adult↗
PubMed2000

Composition of Ragusano cheese during aging.

Ragusano cheese is a brine-salted pasta filata cheese. Composition changes during 12 mo of aging were determined. Historically, Ragusano cheese has been aged in caves at 14 to 16 degrees C with about 80 to 90% relative humidity. Cheeses (n = 132) included in our study of block-to-block variation were produced by 20 farmhouse cheese makers in the Hyblean plain region of the Province of Ragusa in Sicily. Mean initial cheese block weight was about 14 kg. The freshly formed blocks of cheese before brine salting contained about 45.35% moisture, 25.3% protein, and 25.4% fat, with a pH of 5.25. As result of the brining and aging process, a natural rind forms. After 12 mo of aging, the cheese contained about 33.6% moisture, 29.2% protein, 30.0% fat, and 4.4% salt with a pH of 5.54, but block-to-block variation was large. Both soluble nitrogen content and free fatty acid (FFA) content increased with age. The pH 4.6 acetate buffer and 12% TCA-soluble nitrogen as a percentage of total nitrogen were 16 and 10.7%, respectively, whereas the FFA content was about 643 mg/100 g of cheese at 180 d. Five blocks of cheese were selected at 180 d for a study of variation within block. Composition variation within block was large; the center had higher moisture and lower salt in moisture content than did the outside. Composition variation within blocks favored more proteolysis and softer texture in the center.

Cheese↗
PubMed1999

Sigmoidal admission rate-dependence of toluene narcotic potency in rats: comparison with nitrous oxide.

Aromatic solvents, such as toluene, can cause depression of the central nervous system functions in both solvent-exposed workers and abusers. The mechanism by which toluene produces its effects is generally thought to be similar to that produced by general anaesthetics, including inert gases and alcohols. However, whether lipophilic compounds indirectly influence activity by perturbing membrane lipids or bind directly to proteins remains a major question. In a recent study, the sigmoidal admission rate-dependence of inert gas anaesthetic potency has been suggested to possibly reflect a direct narcotic-protein interaction. Therefore, experiments have been carried out using seven input toluene flows of 0.5, 1, 2, 3, 4, 5 and 6 l/min. Our results indicate that as the rate of toluene delivery increased, the concentration of toluene required to produce anaesthetic effects increased. Although this was fitted relatively well with linear regression, this fitted better when using a sigmoidal model (r = 0.998 vs. r = 0.971, P < 0.01). In addition, comparison with previous data on nitrous oxide shows a striking similarity between plots (r = 0.991) which appears consistent with a similar site of action for both agents. We suggest that all classes of lipophilic agents could produce their inhibitory effects at similar 'non-specific' sites of action of finite size and limited occupancy.

Anesthetics, Inhalation↗
PubMed1998

Effects of noise on inferior colliculus evoked potentials and cochlear anatomy in young and aged chinchillas.

Like many aging humans, the aging chinchilla tends to lose high-frequency sensitivity at a faster rate than low-frequency sensitivity. This feature, combined with its excellent low-frequency hearing, makes the chinchilla attractive as an animal model for studying the relationship between noise-induced hearing loss (NIHL) and age-related hearing loss (AHL). In the present study, we examined susceptibility to noise in 15 aged (10-15 years old) and 15 young chinchillas. Two levels of noise were used, with the aim of determining whether age-related differences exist in the magnitude and rate of recovery from temporary threshold shifts produced by a moderate-level (95 dB) noise exposure, or in susceptibility to permanent threshold shifts and cochlear damage caused by a high-level (106 dB) noise exposure. Thresholds and response amplitudes at 0.5, 1, 2, 4, 8 and 16 kHz were determined from evoked potentials recorded from the inferior colliculus. Cochlear histology was performed on animals exposed to high-level noise. The results suggest that older animals are equally vulnerable to moderate-level noise, but may be slightly more vulnerable to high-level noise. For moderate-level exposures, there appears to be a simple additive relationship (in dB) between AHL and NIHL. For high-level exposures, the relationship may be more complex.

Acoustic Stimulation↗