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Biomedical subjects

F Chiarotti

Publications and source records attributed to F Chiarotti.

At least 19 recordsLinked to original sources
PubMed2000

Influence of sex and age on blood pressure variability.

The aim of this study has been to identify changes of 24-h blood pressure variability, as related to age and sex in hypertensive subjects. As regards this point several international studies have shown the increase of morbidity and mortality caused by cardiovascular diseases in postmenopausal women produced by a lack of sex hormones, which had protected the women until this period. Each hypertensive subject was submitted to an ambulatory blood pressure monitoring (ABPM) and two variability indexes were obtained: S.D. and coefficient of variation (CV). The results have shown a strict correlation between blood pressure variability and age, without significant sex-related differences. A decrease of blood pressure variability and mean blood pressure (BP) values have also been found, in the night-time with respect to the day-time data; it was more pronounced in females than in males but this would not seem an age-related difference. Despite the fact that the correlation between blood pressure variability and age is very significant in every considered period in males, it has been found that women have statistical differences only in the day-time and in the nocturnal diastolic blood pressure (DBP) fluctuations. This might be caused by other independent factors, such as a postmenopausal lack of sex hormones.

Journal Article↗
PubMed2000

Fluctuating asymmetry, size and mating success in males of Ischnura elegans (Vander Linden) (Odonata: Coenagrionidae).

Fluctuating asymmetry (FA) is thought to be an indicator of developmental stability and negatively related to male mating success in many animal taxa. We investigated the relationships between mating success of males, body size and FA for both wing length and number of setae on the legs in the damselfly Ischnura elegans. Males were classified as mated or unmated at the time of sampling. Fluctuating asymmetry, expressed as right-left differences, showed normal distributions without evidence of directional asymmetry or antisymmetry. Univariate analyses showed a significant negative correlation between size and mating success, and significant negative correlations between FA and mating success for both characters. On the other hand, with a multivariate analysis, new to studies on FA, the effect of body size was still significant but FA did not reach significance for either character. We conclude that the multivariate analysis should be used to assess the role of the different factors affecting mating success. Copyright 2000 The Association for the Study of Animal Behaviour.

Journal Article↗
PubMed2000

Study of immunological and virological parameters during thalidomide treatment of SIV-infected cynomolgus monkeys.

The potential therapeutic utility of thalidomide (Thd), an effective inhibitor of tumor necrosis factor (TNF)-alpha in vitro, was investigated in cynomolgus monkeys (Macaca fascicularis) at 10 months after infection with simian immunodeficiency virus (SIV). Thd-treated macaques (n = 8) received an oral dose (10 mg) daily for 7 days, followed by a wash-out period of 5 weeks. A 2nd cycle of treatment was performed on the same animals at higher doses (20 mg Thd/day) for 14 days. The control monkeys (n = 7) received a placebo for the same period of time. In the present study, we show that Thd, in addition to inhibiting TNF-alpha production after in vitro mitogen stimulation of peripheral blood mononuclear cells (PBMCs), was able to restore the proliferative responses to SIV peptides in monkeys that were infected with SIV. Interestingly, we found that such effects are associated with an increased expression of CD28 cell surface receptors on CD4+ T-cells paralleled by a decrease on CD8+ T-cells. At the same time, significant reduction in either cell-associated viral load or plasma viral RNA was not observed among the SIV-infected monkeys during the two treatment cycles, when compared with the placebo group.

Administration, Oral↗
PubMed2000

Event-related potentials in the elderly with new mild hypertension.

Hypertension is a risk factor for cerebrovascular diseases (CVD) and cognitive impairment and the relative risk of CVD at every level of blood pressure (BP) is greater among the elderly. We submitted 20 elderly affected by new mild hypertension and 10 elderly normotensives to 24-hour ambulatory BP monitoring (ABPM), to evaluate their cognitive state using the Mini-Mental-State-Examination and to the recording of related acoustic evoked potentials (P300 and N2). We did not find significant differences for P300 latency between hypertensives and normotensives, while N2 latency recording showed a statistically significant protracted value in elderly hypertensives. In these patients we found a significant correlation between the N2 latency and systolic blood pressure values recorded by ABPM. These results demonstrated early functional alterations of cognitive state in elderly hypertensives, that are related to systolic blood pressure and future data might point to an earlier use of therapy.

Aged↗
PubMed1999

The role of high resolution pulsed and color Doppler ultrasound in the differential diagnosis of benign and malignant lymphadenopathy: results of multivariate analysis.

BACKGROUND: The role of high resolution pulsed and color Doppler ultrasound in the differential diagnosis of benign and malignant lymphadenopathy is still unclear. METHODS: High resolution pulsed and color Doppler ultrasound was used prospectively to investigate superficial lymph node enlargement in 71 patients undergoing surgical biopsy at the onset of lymphadenopathy. The aim of this study was to define, in multivariate analysis, the ultrasonographic parameters useful in the differential diagnosis of benign and malignant lymphadenopathy. RESULTS: Volume, vascularization score, pulsatility index, and resistive index were significantly higher in the 53 malignant lymph nodes studied than in the 18 benign lymph nodes studied. The long-to-short axis ratio was significantly lower in neoplastic lymph nodes than in reactive lymph nodes. Stepwise logistic regression selected only the long-to-short axis ratio and the vascularization score as parameters that independently and significantly contributed to the differentiation of neoplastic from reactive lymph nodes. The diagnostic efficiency of the combined criteria evaluated by the area under the receiver operating characteristic curve was 0.8339. CONCLUSIONS: High resolution pulsed and color Doppler ultrasound may provide information that is useful in making correct differential diagnoses of malignant or benign lymphadenopathy.

Adolescent↗
PubMed1999

Behavioural effects of endocrine disrupting chemicals on laboratory rodents: statistical methodologies and an application concerning developmental PCB exposure.

Appropriate behavioural tests and adequate statistical tools may help to establish the ED properties of a given compound by pointing out the alterations of selected behavioural endpoints. Frequently, laboratory collected data consist of frequencies and/or durations of specific items, and the analysis of variance (ANOVA) technique is performed to assess whether the investigated factors affect these behavioural endpoints. Moreover, when numerous aspects of behaviour are investigated simultaneously, Principal Component Analysis (PCA), a multivariate technique, may be very useful to reduce the overwhelming number of correlated original variables to a few orthogonal artificial variables (factors). Continuous Time Markov Chain (CTMC) models may be applied to analyse the time structure of a behavioural pattern when data consist of sequences of events and the time points at which they occur. Moreover, the Cox Proportional Hazard Model, a methodology originally developed for the analysis of failure time data, may help to evidence the effects of a given treatment on behavioural sequences when the assumptions of CTMC models are not fully satisfied. Analyses on data from mice of the outbred CD-1 strain (controls in a study of toxicity and exposed to PCB during development) are presented as examples to show how adequate statistical analyses and appropriate behavioural tests may reveal relevant effect of treatments otherwise not easily detected.

Animals↗
PubMed1999

Clinical and immunologic response without decrease in virus load in patients with AIDS after 24 months of highly active antiretroviral therapy.

This study reports an analysis of clinical, virological, and immunologic outcomes in a cohort of 77 multidrug-experienced AIDS patients during 24 months of highly active antiretroviral therapy (HAART). Our results have shown a reduced risk of AIDS complications, prolonged survival, and immunologic benefit even in the absence of sustained virus suppression. The degree of immunodepression, the risk factors for HIV-1 infection, the use of 2 drugs instead of 3, and a change in protease inhibitor were independently correlated with virological failure. In the majority of studied patients, an increase in CD4+ T cells was observed after HAART. However, the increase was more pronounced in patients who showed a decrease in virus load than in those who did not. Moreover, we observed an absence of relapses among patients who permanently discontinued prophylaxis for Cytomegalovirus retinitis and atypical mycobacterial infections. Peripheral lipodystrophy developed in the majority of patients, regardless of treatment used and virological outcome.

AIDS-Related Opportunistic Infections↗
PubMed1999

Limited changes in handedness and morphine reactivity in CD-1 mice after pre- and postnatal ozone exposure.

Outbred CD 1 mice were either not exposed (control group) or exposed to ozone (O3) (0.3, 0.6, or 0.9 ppm), during foetal and neonatal life until the time of weaning (postnatal day (PND) 26). On PND 70 the subjects were tested for handedness using a paw preference task assessing both the animals' capability to reach a food pellet in a feeding tube and the individual preference for the use of one of the other forepaw. O3 exposure did not affect the animals' capability to learn the task but caused changes in handedness. Specifically, females exposed to the intermediate O3 concentration showed a reduced preference for the right paw than both their same-sex controls and 0.6 ppm males. On PND 100, mice underwent a hot plate test after IP treatment by either saline or morphine HCl (10 mg/kg). The results were generally in the direction of reduced drug sensitivity after exposure to the highest concentration. The evidence for this effect was more robust in the case of an organised avoidance response (wall-rearing) than in the case of a reflexive response (limb withdrawal); in the case of the former, latency data showed an effect on both males and females while frequency data showed an effect only in females. Overall, the O3 effects are suggestive of subtle CNS changes affecting mouse behavioural responses.

Animals↗
PubMed1999

Serum phospholipids are the main environmental determinants of activated factor VII in the most common FVII genotype. European Union Concerted Action "Clotart".

BACKGROUND AND OBJECTIVE: Numerous studies have emphasized the role of triglyceride-rich lipoproteins and of Factor VII (FVII) polymorphisms in determining levels of FVII activity. DESIGN AND METHODS: This study was undertaken to evaluate the role of other lipid fractions and the interaction between lipids and FVII in subjects with recognised genotypes. Volunteer subjects (n=459) from 5 European countries were studied. Blood samples were drawn irrespective of the time of day or fasting status. Levels of FVII activity (FVIIc), activated FVII (FVIIa) and FVII antigen (FVIIAg) were evaluated with reference to a number of lipid parameters (HDL-, LDL- and total cholesterol, triglycerides, phospholipids, lipoprotein(a), and apoliproptein A1). The two most common FVII polymorphisms were analyzed in combination (353R/Q and 5'F7; alleles M1/M2 and A1/A2, respectively). RESULTS: Homozygotes for the A1 and M1 alleles (M11/A11) had significantly higher FVII levels. At multiple regression analysis the strongest predictor of FVIIa and FVIIc was the concentration of phospholipids. This interaction was confined to the A11M11 genotype subjects. INTERPRETATION AND CONCLUSIONS: These data indicate that lipids contribute mainly to FVIIa levels through their phospholipid content, and that the degree of this contribution is strictly dependent on FVII genotypes.

Adult↗
PubMed1998

Determination of antibodies to extractable nuclear antigens by commercial kits: a multicenter study.

Several enzyme immunoassays for serum antibodies to extractable nuclear antigen have recently become available. The aim of this study was to evaluate the results obtained with: (1) the same kit under different conditions; (2) different enzyme immunoassays; (3) Western blot and enzyme immunoassays. Twenty-five sera from patients with autoimmune disorders were tested in five different laboratories by one Western blot and four enzyme immunoassay commercial kits. The different methods produced comparable qualitative results. However, semiquantitative evaluation, based on a cut-off value (index), yielded different results due both to laboratory conditions and to the kits employed. Standardization of commercial products and methods should be improved so that the results of different laboratories can be compared and large-scale and follow-up studies conducted. Western blot analysis could also be useful to analyze complex reactivities, although greater experience is necessary to interpret these results correctly.

Antibodies, Antinuclear↗
PubMed1998

Subclinical visual impairment in phenylketonuria. A neurophysiological study (VEP-P) with clinical, biochemical, and neuroradiological (MRI) correlations.

During detailed visual function testing, pattern-reversal visual evoked potentials (VEP), generated by different spatial frequencies (3 c/d, 1 c/d and 0.6 c/d) and visual contrasts (100% and 10%) were recorded in 21 adolescent and young adult phenylketonuric (PKU) patients (11 females and 10 males; mean age 14.8 years, range 9-22.8) on and off diet. In 14 of the 21 patients, disease had been detected at neonatal screening and in 7 later. Ten age-matched healthy subjects acted as controls. Recordings in more than 40% of eyes in the whole group and 30% of eyes in the screening subgroup showed a prolonged P100 latency. All visual pattern stimuli elicited a significantly longer P100 latency in PKU patients than in controls. VEP latencies to 3 c/d, 1 c/d and 1 c/d with 10% contrast--but not to 0.6 c/d--were longer in patients off diet than in patients on diet. No differences were found between VEP latencies in early- and later-detected subjects. To study the link between biochemical variables and VEP latencies, we envisaged either a linear relationship between recent exposure to phenylalanine (Phe) and VEP abnormalities or a threshold model considering phenylalanine (Phe) concentrations among the factors influencing VEP latencies. The correlation analysis detected an association between plasma Phe concentrations and abnormal VEP latencies, predicting that plasma Phe concentrations > 901 mumol/L would prolong VEP latencies to 1 c/d; concentrations > 879 mumol/L would prolong latencies to 3 c/d; and concentrations > 898 mumol/L would prolong latencies to 1 c/d with 10% contrast.

Adolescent↗
PubMed1998

Elevated novelty seeking and peculiar d-amphetamine sensitization in periadolescent mice compared with adult mice.

Novelty seeking as well as amphetamine sensitization were studied in adult (postnatal day "PND" > 60) and periadolescent (PND 3343) mice treated with saline or amphetamine (2 or 10 mg/kg once per day) for 3 days in a familiar environment. After a 48-hr wash-out period, mice were challenged with either saline or amphetamine (2 mg/kg) in the same environment. When given a choice, animals showed a preference for a novel environment, an effect more marked in periadolescents. Acute amphetamine strongly increased novelty seeking in adults, whereas it had an opposite effect in periadolescents. Adult mice in the chronic amphetamine 2 group showed a conditioned preference for the drug-paired compartment, whereas an aversion characterized adult mice in the amphetamine 10 group. Periadolescents in the latter group exhibited a greater sensitization of the locomotor response, but did not show the compulsive licking typical of adults. This appears to be a useful model to study psychobiological risk factors involved in vulnerability to addiction during human adolescence.

Aging↗
PubMed1998

Behavioural characterization of interleukin-6 overexpressing or deficient mice during agonistic encounters.

Interleukin-6 (IL-6) is a cytokine released by activated immune cells which has been shown to affect brain function. In this experiment aggressive and affiliative behaviour exhibited during agonistic encounters by transgenic male mice either not expressing (IL-6 -/-) or overexpressing (NSE-hIL-6) IL-6 in the central nervous system was investigated. All subjects were isolated for 24 days before the aggressive encounter and were 52 days old at the time of testing. Subjects were placed for 5 consecutive days in a neutral cage for 15 min with an opponent of the Balb/c strain that had been previously isolated for the same amount of time. The first and the last test sessions were videotaped to evaluate the first approach and the establishment of the social role, respectively. A number of behavioural categories were later scored. When compared with wild-type controls, IL-6 -/- mice showed a higher degree of aggressive behaviour as indicated by a higher frequency of Offensive Upright Posture, an effect more pronounced on the fifth encounter. On the contrary, NSE-hIL-6 subjects showed a tendency to be more involved in affiliative-type social interactions, displaying a higher frequency and duration of behaviours such as Anogenital, Nose or Body Sniff. IL-6 -/- mice showed a clear tendency to exhibit less affiliative interactions compared with their controls while dopamine levels were found to be modified in a number of brain regions in these mice. Overall, these data suggest that IL-6 affects both aggressive and affiliative-type interactions, although the behaviour of the NSE-hIL-6 subjects was less affected than that of the IL-6 -/- group. The effects of the genetic background of the animal in screening the outcome of gene manipulations on behaviour are also discussed.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1998

Sensitivity and specificity of some neuropsychological markers of Alzheimer dementia.

A standardized neuropsychological test battery was administered to 167 patients with different forms of mild-to-moderate dementia: probable Alzheimer dementia (AD: n = 49), multi-infarct dementia (n = 43), idiopathic Parkinson disease with dementia (n = 35), depressive pseudodementia (n = 26), and progressive supranuclear palsy (n = 14). Results obtained were used (a) to analyze the profiles of cognitive impairment shown by the different dementia groups; (b) to assess the incidence of some neuropsychological patterns that we hypothesized to be more characteristic of AD, in the various groups; and hence (c) to evaluate the reliability of these patterns as diagnostic markers of AD. Four of the patterns investigated were derived from a verbal learning task (Rey's Auditory Verbal Learning test): (1) absence of the primacy effect; (2) tendency to produce intrusion errors during free recall of a word list; (3) absolute decay of memory trace; and (4) tendency to produce false alarms during delayed recognition of the same word list. Two additional patterns were derived from visual-spatial tasks (copying drawings and Raven's Coloured Progressive Matrices): (5) occurrence of the closing-in phenomenon in copying drawings; and (6) tendency to choose globalistic or odd responses in Raven's matrices. Though all the six patterns were somewhat useful for identifying AD patients, no pattern met the criteria of being both highly sensitive and highly specific, which should characterize an ideal marker. In fact, intrusions and false alarms were observed in many AD patients, but also in patients affected by other forms of dementia. The absence of the primacy effect, the closing-in phenomenon, and the absolute decay of memory trace were more specific, but could be observed in only one-third of AD patients. We also computed the number of positive patterns shown by each patient and assumed the presence of two or more patterns as a global index suggestive of a dementia of the Alzheimer type. With this cumulative method, a higher level of sensitivity and specificity was achieved in the identification of AD patients.

Aged↗
PubMed1997

Collateral flow prevents unintentional myocardial ischemia during antegrade cardioplegia in patients undergoing coronary artery bypass grafting.

OBJECTIVE: We evaluated, in the prevention of perioperative unintentional myocardial ischemia, the role of coronary collateral flow in patients with left anterior descending coronary artery stenosis or occlusion who underwent elective coronary artery bypass grafting. METHODS: Coronary lesions and collaterals were assessed by coronary angiography in 21 patients. Anteroseptal myocardial viability was evaluated by dobutamine echocardiography. Antegrade perfusion of cardioplegic solution was assessed by myocardial contrast echocardiography. Time-intensity curves were generated from the anteroseptal region. Twelve parameters were measured and averaged in the following four groups of patients: those with stenosis of the left anterior descending artery and poor collaterals; those with stenosis of the left anterior descending artery and good collaterals; those with occlusion of the left anterior descending artery and good collaterals; and those with occlusion of the left anterior descending artery and poor collaterals. RESULTS: Time-intensity curves were significantly different in patients with stenosis versus occlusion of the left anterior descending artery (p < 0.005); multiple comparisons with Bonferroni's correction showed that this difference was mainly a result of the impact of collateral circulation (p < 0.01). However, the role of collaterals was nonsignificant within the groups with stenosis and occlusion of the left anterior descending artery. Patients with occlusion of the left anterior descending artery and good collaterals had perfusion parameters similar to those of patients with stenosis of the left anterior descending artery (p = not significant), except for the ascending slope and time to peak values (p < 0.05 and p < 0.01, respectively), which reflected a higher flow resistance in the collateral circulation. Regional systolic function after coronary artery bypass grafting was depressed in patients with poor collaterals and poor perfusion of cardioplegic solution, as compared with findings in other subgroups. CONCLUSIONS: Incomplete myocardial protection may impair the early recovery of function after coronary artery bypass grafting.

Cell Survival↗
PubMed1997

Contribution of factor VII genotype to activated FVII levels. Differences in genotype frequencies between northern and southern European populations.

The relationship between coagulation factor VII (FVII) levels in plasma and FVII genotypes, determined by three polymorphisms (5'F7, IVS7, and 353R/Q), were studied in 500 control subjects enrolled in European multicenter study. The selection of particular FVII genotypes and the analysis of variance clearly indicated the independent contribution of a single 5'F7 insertion (A2) or 353Q (M2) allele to lowering plasma levels of activated FVII (FVIIa) (by a mean 25%). The M2 allele alone was found to make a major contribution to the genetically determined component of the FVIIa levels. Genotypes associated with low FVII levels were significantly rarer in the northern part of Europe (Oslo) than in the southern part (Rome, Murcia). The contribution made by the FVII genotype to the total variance of FVIIa levels was higher (30%) than that made to either FVII activity (25%) or FVII antigen (12%). Subjects with different FVII genotypes showed up to fivefold differences in mean FVIIa values, thus allowing attribution of a substantial part of the considerable interindividual variation to genetic variation, which may be of assistance in the interpretation of FVIIa levels on an individual basis. When FVII levels were adjusted by age and by triglyceride levels, the contribution of FVII genotypes to the FVII phenotypic variance was virtually unchanged. Taken together, these data indicate that in healthy control subjects the FVII genotype is a major predictor of plasma FVIIa levels and would support further study on the role of FVII genetic components in the development of cardiovascular disease.

Adult↗