Biomedical subjects

A Miozzo

Publications and source records attributed to A Miozzo.

12 recordsLinked to original sources

PubMed2003

A fMRI study of word retrieval in aphasia.

The neural mechanisms underlying recovery of cognitive functions are incompletely understood. Aim of this study was to assess, using functional magnetic resonance (fMRI), the pattern of brain activity during covert word retrieval to letter and semantic cues in five aphasic patients after stroke, in order to assess the modifications of brain function which may be related to recovery. Four out of five patients had undergone language recovery, according to standard testing, after at least 6 months of rehabilitation. The cerebral activation of each patient was evaluated and compared with the activation pattern of normal controls studied with the same fMRI paradigm. In the patients, the pattern of brain activation was influenced by the site and extent of the lesion, by the degree of recovery of language, as reflected by task performance outside the scanner, and by task requirements. In the case of word retrieval to letter cues, a good performance was directly related to the activation in Broca's area, or in the right-sided homologue. On the other hand, in the case of semantic fluency, the relationship between performance level and activation was less clear-cut, because of extensive recruitment of frontal areas in patients with defective performance. These findings suggest that the performance in letter fluency is dependent on the integrity of the left inferior frontal cortex, with the participation of the homologous right hemispheric region when the left inferior frontal cortex is entirely of partially damaged. Semantic fluency, which engages the distributed network of semantic memory, is also associated with more extensive patterns of cerebral activation, which however appear to reflect retrieval effort rather than retrieval success.

Aged↗

PubMed1999

Confabulation and delusional misidentification: a four year follow-up study.

We describe a patient, AZ, who showed, in addition to an amnesic syndrome which eventually improved, longstanding confabulation and delusional misidentification following bilateral frontal and right temporal post-traumatic lesions. Confabulation appeared in personal recollections and on long-term verbal memory testing. Misidentification concerned mainly his wife and house. During the four year follow-up AZ's confabulation progressively shrinked so as to become restricted to verbal memory tasks. By contrast, misidentification persisted. General semantic memory was unimpaired throughout, while performance on frontal tests was initially poor and partly improved in time. We argue that confabulation and misidentification, though often intermingled and occurring after similar lesion pattern, should be considered as different neuropsychological entities.

Amnesia↗

PubMed1997

The representation of stress: evidence from an aphasic patient.

We report the case of an aphasic patient who, following an acquired lesion involving the left temporo-parietal cortex, produced many word stress errors in spontaneous speech, naming of objects and reading aloud. The stress impairment concerned exclusively words in which stress was unpredictable on the basis of syllabic structure, and was equally severe in naming and reading aloud. Errors were significantly more frequent in the cases of words with stress on the antepenultimate syllable, and of low frequency words. There was a high consistency between errors in naming and reading aloud. These findings suggest that stress representation can be selectively impaired after brain damage; we hypothesise that a partial disorder at the level of the form lexicon, involving the representation of lexical stress, can account for most of the features of the patient's performance.

Adult↗

PubMed1996

Varieties of progressive non-fluent aphasia.

We report four patients with progressive aphasia of the non-fluent type as the presenting clinical manifestation. The patients were included in a longitudinal study of focal progressive neuropsychological syndromes, and were periodically submitted to neuropsychological evaluations and neuroimaging studies (TC, MRI, SPET or PET). The pattern of neuropsychological impairment was in good agreement with the results of functional imaging studies, which indicated involvement of the anterior regions of the left hemisphere. The evolution of the clinical picture was extremely heterogeneous in the four patients, ranging from a relatively stable picture of transcortical motor aphasia to a severe progressive frontal lobe syndrome. Progressive non-fluent aphasia appears to be a reliable clinical marker of the localization of the pathological process; whether this is related to specific neuropathological conditions, such as Pick's disease, remains for the moment a matter of speculation.

Adult↗

PubMed1996

Persistent post-traumatic retrograde amnesia: a neuropsychological and (18F)FDG PET study.

We report the case of a 48-year old woman who, after a severe closed head injury, developed a severe and persistent disruption of retrograde memory, associated with a mild impairment of learning abilities. The patient's dense amnesia spared only the childhood period and included both explicit memory (autobiographical and semantic) and procedural skills. Because of her partially spared learning ability and intact language, intensive training by family members resulted in the reacquisition and retention of many autobiographical events and of some skills she had lost after the accident. Brain CT scan and MRI were normal; a PET study with (18F)FDG revealed a significant bilateral reduction of metabolism in the hippocampus and anterior cingulate cortex, suggesting a role for these structures in memory for past events.

Amnesia↗

PubMed1995

myc-immortalized microglial cells express a functional platelet-activating factor receptor.

The autacoid platelet-activating factor (PAF) takes part in a complex network of interactions regarding the cellular components of nervous tissues. Efforts aimed at characterizing the effects of PAF in the brain have been recently focalized on neurons because PAF exerts pleiotropic effects on these cells. Less attention has instead been paid to the glial component of the brain. We have used microglial cell lines immortalized from 13-day-old mouse embryo brains by a myc-transducing retrovirus. When exposed to physiological doses of PAF, immortalized microglial cells showed increases in intracellular free calcium concentrations due to release of calcium from internal stores, as well as to extracellular calcium influxes. These profiles of reactivity were independent from the immortalizing process, being observable in primary microglial cultures and in immortalized clones showing different proliferative rates. PAF was also able to induce transient expression of the c-fos protooncogene in serum-starved cultures and induced a strong chemotactic response in microglial cells. In contrast with control macrophage cultures, PAF did not promote prostaglandin or leukotriene synthesis in immortalized cells. This was most likely due to the low amount of total arachidonic acid found in immortal microglia, with respect to that observed in freshly isolated cells. Our data suggest that several of the effects observed after PAF stimulation might be independent from PAF-induced arachidonic acid metabolism. The availability of an in vitro microglial model might now help in studying the proinflammatory effects of PAF, both direct or microglia mediated, in the neural environment.

Animals↗

PubMed1994

Effects of loratadine on cytosolic Ca2+ levels and leukotriene release: novel mechanisms of action independent of the anti-histamine activity.

Loratadine, a non-sedating anti-histamine drug, displays in vitro potential anti-allergic properties not related to its interaction with the histamine H1 receptor. In a search for the mechanisms of these actions, we have found that loratadine induces an elevation of cytosolic calcium ion, [Ca2+]i, in rat peritoneal macrophages or human platelets. The mechanism of this elevation resides in the ability of loratadine to discharge intracellular Ca2+ stores, similarly to thapsigargin. This in turn brings about the inhibition of [Ca2+]i rise induced by physiological activators (platelet activating factor and ADP), as well as by thapsigargin. One of the active metabolites of loratadine, descarbo-ethoxy-loratadine, and another anti-histamine, namely terfenadine, exhibit the same effects. In addition, loratadine partially inhibits antigen-induced leukotriene release from human bronchi, but is unable to inhibit the concomitant contraction. We conclude that loratadine can interfere with the mechanisms controlling Ca2+ release, thus inhibiting the cell activation elicited by various agonists through [Ca2+]i elevation. This might be the mechanism underlying its anti-allergic actions in vitro. Furthermore, loratadine might represent an interesting tool in the study of Ca2+ homeostasis.

Animals↗

PubMed1994

Pure anomia with spared action naming due to a left temporal lesion.

We report the case of a patient who, after surgical ablation of an angioma in the depth of the left temporal lobe, developed a highly selective impairment of naming. A detailed investigation allowed to exclude a disorder of visual recognition or of semantic memory, and indicated the output lexicon as the most probable site of impairment. Grammatical class effects, with superior action naming, and a high consistency within and across output modalities further characterized the patient's performance. Together with some other recently reported cases, this patient suggests a correlation between temporal lobe lesions outside Wernicke's area and output lexicon disorders. A relatively spared action naming seems to be a characteristic feature of this pattern of impairment.

Adult↗

PubMed1993

A community survey on maternal and child health services utilization in rural Ethiopia.

A household health interview survey on MCH services utilization was carried out in 22 villages of a rural district of Arsi region, Ethiopia, before the launching of an integrated MCH programme. Coverage of antenatal services was 26%, and 61% of the women who received antenatal care reported having had 3 or more visits. Antenatal care was positively associated with living within 10 km of the Health Centre. Twenty-eight percent of the mothers attended the under-5 clinic and most returned for 3 or more visits. In addition, 99% reported having breast-fed their last child but more than 25% started weaning only after the seventh month of age. Differences in practice of treating diarrhoea according to knowledge of ORS were found. Of the 33% of those with knowledge of ORS, almost 90% reported use of ORS for treating child's diarrhoea, showing a positive attitude towards modern health care. The proportion of women using family planning was 5%, with no difference found between Christians and Muslims. Results on EPI coverage validated data from routine reporting. Integration of MCH services including out-reach activities may increase access and coverage of MCH services.

Adolescent↗

PubMed1993

Estimation of early childhood mortality using preceding birth technique in a community-based setting.

The preceding birth technique, an indirect method for estimating early childhood mortality based on ascertaining the survival of previous children, was applied in rural Ethiopia within a system of demographic surveillance. Trained community health workers acted as interviewers and transmission flow of the routine health information system was used for data reporting. Data were collected for a median 12 month period from 39 sampled villages of Ticho district in Arsi region. From 1064 mothers having at least a second birth, the proportion dead of the last birth was 0.138 (95% CI 0.117-0.150), corresponding approximately to the probability of dying between birth and age two. It approximates to an infant mortality rate of about 100 x 1000 live-births. From 974 mothers having at least a higher-order birth, the proportion dead of the second to last birth was 0.203 (95% CI 0.178-0.228), equivalent to the risk of dying between 0 and age 5. In spite of the progressive migration of the surveyed population, the process and the outcome of the study suggest that PBT may well be inserted into a primary health care information system run by trained community health workers.

Birth Order↗

PubMed1988

An outbreak of cholera in a refugee camp in Africa.

A total of 541 cases of cholera were observed between May 7 and July 19, 1985 among the 9,929 displaced persons present in a refugee camp in Africa. In spite of malnutrition and other diseases affecting this population, only 12 deaths occurred. Antiepidemic measures consisted of preparation of isolation-wards, treatment of contaminated materials, training of refugees and patient care. Mass prophylaxis, initially considered, was dropped before the end of the epidemic.

Adolescent↗

PubMed1988

Hepatitis B infections in the Arsi region of Ethiopia.

In a sample of inhabitants of the Arsi region of Ethiopia prevalence of hepatitis B is around 80% in the age group 20-24. In addition to age, sex and size of family, exposure to tribal practices is a determinant of seropositivity in this group accounting for as much as 20% of the total burden of the infection. Waiting for a mass vaccination campaign, presently unrealistic in this area of the world, health education, as part of a comprehensive primary health care program, has to be considered as a potentially effective preventive tool.

Adult↗