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Biomedical subjects

A Basso

Publications and source records attributed to A Basso.

At least 19 recordsLinked to original sources
PubMed2005

Fractal characterisation of boundary irregularity in skin pigmented lesions.

A growing literature shows researcher's interest in fractal analysis, arising from its ability to describe and characterise quantitatively the complexity of several tumour profiles. The aim of the work was to investigate the fractal properties of skin pigmented lesion boundaries. Although melanoma is one of the most aggressive tumours, early detection and a high rate of diagnostic accuracy, followed by timely excision, can allow complete recovery in melanoma patients. A modified approach to fractal dimension estimation was performed that was able to consider, in a data fit procedure, the range in which lesions show fractal properties. Identification of this zone is the most important step towards a correct fractal analysis procedure. The method was checked against a known fractal dimension object (Koch's curve) with an error of 0.007. The fractal dimension was estimated in 110 skin pigmented lesions and showed a significantly increasing linear regression (p < 0.05), from common naevi to naevi with dysplasia to melanomas. This result is important for screening, as it can inform the decision to excise precociously malignant lesions or to avoid unnecessary removal of benign ones. The limitations of the method are discussed.

Diagnosis, Differential↗
PubMed2003

Analytical control of photocatalytic treatments: degradation of a sulfonated azo dye.

The degradation of Methyl Orange (C(14)H(14)N(3)SO(3)Na), chosen as a model sulfonated azo dye, was investigated in aqueous solutions containing suspended polycrystalline TiO(2) particles under irradiation with simulated sunlight. The dye disappearance and the formation of the mineralization end products were monitored; the formation of the main transient intermediates was also examined in detail. Particular attention was devoted to the identification and to the evolution of fragments retaining the chromophoric group. The comparison of data coming from various analytical techniques led to a possible reaction mechanism for the degradation process, giving insight into an aspect of the treatment which has not been considered in previous studies.

Journal Article↗
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↗
PubMed2003

Effect of shift work on body mass index: results of a study performed in 319 glucose-tolerant men working in a Southern Italian industry.

OBJECTIVE: To examine the influence of shift work on metabolic and cardiovascular risk factors in subjects working in an industry sited in Apulia, Southern Italy. DESIGN: Cross-sectional study of metabolic effects of shift work in glucose tolerant workers in a chemical industry in southern Italy. SUBJECTS: The subjects included 319 glucose tolerant male individuals, aged 35-60 y. MEASUREMENTS: Anthropometric parameters (body mass index (BMI) and waist-to-hip ratio (WHR)), fasting concentrations of glucose, insulin, and lipids (total cholesterol, HDL-cholesterol, triglycerides), the sum of glucose levels during 75 g-oral glucose tolerance test (Sigma-OGTT), and systolic and diastolic blood pressure (SBP and DBP, respectively). RESULTS: The prevalence of obesity was higher among shift workers compared to day workers, whereas body fat distribution was not different between the two groups. Shift workers had higher BMI than day workers, and shift working was associated with BMI, independently of age and work duration. Shift workers had significantly higher SBP levels, which were independently influenced by BMI, but not by shift work, thus suggesting that the difference in SBP may well be mediated by the increased body fatness. CONCLUSION: In workers of an industry sited in Southern Italy, shift work may be directly responsible for increased body fatness and is indirectly associated with higher blood pressure levels and some features of metabolic syndrome.

Adult↗
PubMed2002

Quality of life in patients with traumatic brain injury-basic issues, assessment and recommendations.

INTRODUCTION: Traumatic brain injuries (TBI) are one of the most common consequences of traffic accidents. Patients with mild, moderate or severe brain injuries suffer from physical, cognitive, behavioral, emotional and social problems. Most of these problems have been a long standing focus amongst practitioners and researchers. Only recently a development has started that took interest in the quality of life outcome of TBI patients. The international members of this consensus meeting reviewed the literature on Quality of Life assessment after TBI and discussed the applicability of different measurements to this specific patient group. TIME POINTS: During the acute phase (T1; < 3 month after trauma) QoL it is difficult to assess due to the reduced consciousness of TBI patients. In the phase of rehabilitation (T2; < one year after trauma) and in the post-rehabilitation phase (T3) repeated assessment of QoL is recommended. INSTRUMENTS: Several generic and disease-specific instruments possibly relevant to TBI patients or specifically developed for this group were assessed according to the existing evidence in the literature. Criteria for the evaluation of these instruments were: feasibility, specificity, validity, comprehensiveness, international availability, existence of norms, and psychometric quality. The cognitive impairment and the existential dimension were not sufficiently considered in most of the reviewed instruments. GROUP CONSENSUS: The family's and relatives' view of the patient's QoL should not be used as a proxy but provides an additional source of information in the acute phase. At T2 and T3, assessment of the patient's quality of life should include a generic as well as a disease specific instrument. Among the generic instruments the SF-36, the EuroQol and the WHO-QoL should be considered. The literature about specific instruments for patients with TBI like the EBIC is scarce. Therefore, the group could hardly give an empirically based recommendation. The need for further investigation on QoL instruments in TBI patients is strongly emphasized.

Brain Injuries↗
PubMed2001

The tyrosine kinase inhibitor ZD1839 ("Iressa") inhibits HER2-driven signaling and suppresses the growth of HER2-overexpressing tumor cells.

The epidermal growth factor receptor (EGFR) is commonly overexpressed in many human tumors and provides a new target for anticancer drug development. ZD1839 ("Iressa"), a quinazoline tyrosine kinase inhibitor selective for the EGFR, has shown good activity in preclinical studies and in the early phase of clinical trials. However, because it remains unclear which tumor types are the best targets for treatment with this agent, the molecular characteristics that correlate with tumor sensitivity to ZD1839 have been studied. In a panel of human breast cancer and other epithelial tumor cell lines, HER2-overexpressing tumors were particularly sensitive to ZD1839. Growth inhibition of these tumor cell lines was associated with the dephosphorylation of EGFR, HER2, and HER3, accompanied by the loss of association of HER3 with phosphatidylinositol 3-kinase, and down-regulation of Akt activity. These studies suggest that HER2-overexpressing tumors are particularly susceptible to the inhibition of HER family tyrosine kinase signaling and suggest novel strategies to treat these particularly aggressive tumors.

Antibodies, Monoclonal↗
PubMed2001

Use of mathematical models of survivorship in the study of biomarkers of aging: the role of heterogeneity.

An ever increasing number of people have been engaging in aging research using various interventions aimed to modify aging processes, and/or life span, of experimental animals. Since this type of studies needs outcome parameters for assessing the efficacy of such interventions, research on biomarkers of aging (ABs) has received new stimuli. In the present paper, the problem of the occurrence of a vicious circle any time we study ABs and determinants of aging is addressed. In fact, while ABs would represent the standard reference to be used in the study of the main causes of processes of aging, these very determinants should already be known in order to get reliable ABs. A feasible way to overcome this impasse is proposed, using mathematical models of survivorship or mortality based on biological hypotheses and accounting for inter-individual heterogeneity, a necessary ingredient for a correct interpretation of survival results. Specific kinetics of experimental parameters that are candidates as ABs can be compared to the kinetics hypothesized for general biological functions entering the model. We have built a model of this type that can also be used to perform a reliable overall gross estimate of the rate of aging, R(a), in the population, a parameter useful when judging the success of interventions aimed to act on determinants of aging. The perspective that theory of complex systems can be of help in the search for ABs is also discussed.

Aging↗
PubMed2001

Long-live euthymic BALB/c-nu mice. I. Survival study suggests body weight as a life span predictor.

This paper is the first of a series aimed to show the main physiological and pathological characteristics of male euthymic BALB/c-nu mice, a long-live strain of BALB/c mice bred in our own Institute. In particular, the first two paired papers are respectively devoted to general survival information and disease characteristics, also taking into account very old animals that are of high interest for studies on successful aging. In this paper we report the analysis of survival kinetics, the time course of body weight and the correlation between body weight and time-at-death. The longitudinal study has been performed on 88 male mice, checking individually their body weight and date of death and analyzing survival data by a model built by our own. Survival analysis shows quite higher longevity (median age: about 29 months) in this population when compared with other BALB/c strains. The most relevant finding on body weight is its correlation with longevity until the age of 22 months: thinner subjects live longer and lose weight at a lower rate than their heavier mates. Results have formed the basis on which to plan the cross-sectional experiment to study pathologies and biological parameters at different ages, including a group of mice at very advanced ages (34 months).

Animals↗
PubMed2001

Long-live euthymic BALB/c-nu mice. II: spontaneous tumors and other pathologies.

This paper is the second of a series aimed to show the main physiological and pathological characteristics of male euthymic BALB/c-nu mice, a long-live strain of BALB/c mice bred in our own Institute. The previous paired paper Piantanelli (Mech. Ageing Dev. (2001)) has been devoted to a survival study up to advanced ages highly interesting for studies on successful aging. In the present paper we report first data of a cross-sectional study on 4,15,22,28 and 34 months-old mice, dealing with tumors and other relevant pathologies. Results have shown that tumors or other pathologies can hardly be detected up to the age of 22 months. At 34 months of age about 40% of mice revealed a variety of neoplasia and other diseases are clearly detectable. These results suggest that a significant increase in longevity could be a factor increasing the risk of tumor development; thus, caution has to be paid in studies on mice utilized for long term carcinogenicity assay, where animals are sacrificed at the age of 18 months, according to the International Program. Finally, animals of the same chronological age have been subdivided in clusters according to their presumptive longevity, estimated taking advantage of the relationship between body weight and age-at-death found in the paired longitudinal study. This subdivision will be helpful in interpreting inter-individual variability of the biological parameters checked in these animals.

Aging↗
PubMed2001

Acquisition of new "words" in normal subjects: a suggestion for the treatment of anomia.

The study explores the efficacy of three learning methods in normal controls. Thirty subjects, randomly assigned to the repetition, reading aloud, or orthographic cueing method, were asked to learn 30 new "words" (legal nonwords arbitrarily assigned to 30 different pictures); 30 further new "words" were used as controls. Number of trials to criterion was significantly lower, and number of words remembered at follow-up was significantly higher for the orthographic cueing method. Two aphasic patients with damage to the output lexicons were also rehabilitated with the same three methods. In both patients the orthographic cueing method was significantly more efficacious. The differences in learning efficacy of the three methods are discussed.

Adult↗
PubMed2001

Advances in management of neurosurgical trauma in different continents.

Neurotrauma is a major public health problem. The incidence varies from 67 to 317 per 100,000 and mortality rates are in the range of near 1% for minor injury, 18% for mild injury, and 48% for severe head injury. It is the main cause of death and disability in people under 40 years old. Several problems appear when outcome measurements, rehabilitation programs and treatment options are considered. In order to solve these problems a worldwide campaign is outlined. It focuses on epidemiology, prevention, education, treatment, rehabilitation, social re-insertion, and outcome measurements. The goals of such a program are to take into account realities in both developed and developing countries, to develop worldwide acceptable programs and guidelines, and to test those guidelines and programs and diminish mortality and morbidity, improving quality of life. We describe the concept of Centers of Excellence and an educational program, Advanced Brain Life Support. Such a program is a moral obligation because mortality and morbidity tend to decrease in Centers of Excellence.

Brain Injuries↗
PubMed2001

Bromocriptine and the expression of c-myc and c-fos in human prolactinomas.

Prolactinomas are one of the most frequent tumors of the human anterior pituitary. Dopamine agonists are the choice in the medical treatment of this disease. Bromocriptine (BC) is a well known anti-neoplasic agent in human PRL secreting adenomas although its effect on PRL cells is far from clear. We decided to investigate its influence on cell proliferation parameters: (3H)thymidine incorporation, expression of c-myc and c-fos, and number of estrogen receptors present in the samples. A total of 28 patients were included in this protocol. They were treated with BC (5-7.5mg day(-1) patient(-1)) or with vehicle orally 15 days before surgery. We found that in BC treated patients (3H)thymidine incorporation was lower than in vehicle treated patients. The oncogenes expression were diminished in BC comparing with vehicle-treated patients. No difference in the number of estrogen receptors was observed in the samples from BC or vehicle-treated patients. These results clearly demonstrate that one mechanism to reduce the size of human PRL secreting adenomas by BC is the inhibition of DNA duplication.

Adult↗
PubMed2001

Modulation of Hsp90 function by ansamycins sensitizes breast cancer cells to chemotherapy-induced apoptosis in an RB- and schedule-dependent manner. See: E. A. Sausville, Combining cytotoxics and 17-allylamino, 17-demethoxygeldanamycin: sequence and tumor biology matters, Clin. Cancer Res., 7: 2155-2158, 2001.

17-allyl-aminogeldanamycin (17-AAG) is an ansamycin antibiotic that binds to a highly conserved pocket in the Hsp90 chaperone protein and inhibits its function. Hsp90 is required for the refolding of proteins during cellular stress and the conformational maturation of certain signaling proteins. 17-AAG has antitumor activity in cell culture and animal xenograft models and is currently in clinical trial. It causes an RB-dependent G(1) arrest, differentiation, and apoptosis. RB-negative cells arrest in mitosis and undergo apoptosis. Hsp90 plays an important role in the cellular response to environmental stress. Therefore, we tested whether the regulation of Hsp90 function by 17-AAG could sensitize cells to cytotoxic agents. 17-AAG sensitized tumor cells to Taxol and doxorubicin. Taxanes cause growth arrest in mitosis and apoptosis. The addition of 17-AAG to cells after exposure to Taxol significantly increased both the activation of caspases 9 and 3 and apoptosis. In cells with intact RB, exposure to 17-AAG before Taxol resulted in G(1) arrest and abrogated apoptosis. Schedule dependence was not seen in cells with mutated RB, because both agents blocked cells in mitosis. Schedule- or RB-dependence was also not observed when cells were treated with 17-AAG and doxorubicin, a DNA-intercalating agent that acts on different phases of the cell cycle. These findings suggest that inhibition of Hsp90 function by 17-AAG enhances the apoptotic effects of cytotoxic agents. The sequence of drug administration and the RB status significantly influence efficacy.

Anti-Bacterial Agents↗
PubMed2001

Assessment of calculation and number processing using the EC301 battery: cross-cultural normative data and application to left- and right-brain damaged patients.

To provide referential normative data on simple tasks dealing with number processing and calculation which could be used in clinical investigations, 551 normal volunteers aged between 18 and 69 years from France and Belgium (n = 180). Italy (n = 212) and Germany (n = 159). performed the 31 tasks which constitute the EC301 calculation and number processing battery. Differences between countries were significant for 16 tasks and a Gender x Education interaction was observed for some tasks, with men performing better than women among subjects with low education only. To present an overview of preserved and impaired calculation and number processing abilities in left-brain damaged (LBD) aphasic patients and right-brain damaged (RBD) nonaphasic patients, the 31 subtests of the EC301 battery were proposed to 80 patients with cerebrovascular accident, 56 left and 24 right, for most cases in the territory of the middle cerebral artery. LBD aphasic patients showed low performance on oral and alphabetical spoken verbal and written verbal counting, transcoding when a written code was involved, and mental or written calculation; but relatively good performance at finding the number of elements in small sets, comparing numbers written in the Arabic digital code and placing correctly numbers on an analogue number line. The lowest performances of RBD patients were observed for estimation tasks and for placing a number on a scale. Results and their implications for further research are discussed according to the present information processing and anatomofunctional models of calculation and number processing.

Adolescent↗
PubMed2000

The natural course of acalculia in left-brain-damaged patients.

Acalculia is a frequent disorder in left-brain-damaged patients but nothing is known about its natural course. We report a study on 51 vascular acalculic patients examined at least twice. Our results indicate that recovery from acalculia is possible in the first months post-stroke, that initial severity does not significantly influence recovery, and that it correlates with recovery of auditory comprehension.

Adult↗
PubMed2000

Acalculia, aphasia and spatial disorders in left and right brain-damaged patients.

The paper reports the performance of 50 left- and 26 vascular right-brain-damaged (LBD, RBD) patients in the EC301 Calculation Battery, which explores different aspects of number and calculation processing. All patients underwent a comprehensive neuropsychological testing that also included evaluation for the presence and type of aphasia in LBD patients, and of spatial disorders in RBD patients. LBD were subdivided in three groups: non-aphasic (NA), Broca and Wernicke aphasics. Results indicate that language and calculation disorders can dissociate. The relationship between spatial and calculation disorders in RBD patients is less clear. No significant difference was found between Broca and Wernicke aphasics, nor between NA and RBD patients. In the transcoding tasks (reading or writing to dictation numbers and number words, for instance) syntactic errors were the most frequent type of errors in all groups. They were also present when neither the input nor the required response was in the Arabic code, and a word-by-word strategy could have been used to read the number word or write a spoken number in the orthographic code.

Adult↗
PubMed2000

Perceiving left and imagining right: dissociation in neglect.

Signor Piazza, a patient with a left parieto-occipital haemorrhage and a right thalamic stroke, showed severe right personal neglect (e.g. touching own body parts) and right perceptual neglect in tasks with (e.g. cancelling tasks) or without (e.g. description of a complex picture) motor response. He had also right-sided neglect dyslexia (including single words), without language impairments. However, the patient also presented with a clear left-sided deficit in the representational domain (e.g. imagery tasks). Signor Piazza's pattern of performance suggests dissociation between imagery and perception within the neglect syndrome.

Aged↗