Biomedical subjects

A Bottoni

Publications and source records attributed to A Bottoni.

At least 19 recordsLinked to original sources

PubMed2005

Dopamine receptor subtype 2 and somatostatin receptor subtype 5 expression influences somatostatin analogs effects on human somatotroph pituitary adenomas in vitro.

Dopamine (DA) and somatostatin (SRIF) receptor agonists inhibit growth hormone (GH) secretion by pituitary adenomas. We investigated DA subtype 2 receptor (DR2) and SRIF receptor (sst) subtypes 2 and 5 expression in 25 GH-secreting pituitary adenomas and tested in primary culture the effects on GH and prolactin (PRL) secretion of sst agonists selectively interacting with sst2 (BIM-23120), sst5 (BIM-23206), and sst2 and sst5 (BIM-23244). All adenomas expressed sst2; eight adenomas expressed both sst5 and DR2, eight sst5 but not DR2, and eight DR2 but not sst5. One tissue lacked expression of DR2 and sst5. GH secretion was inhibited by BIM-23120 in all samples, while it was reduced by BIM-23206 only in adenomas not expressing DR2. BIM-23120's inhibitory effects correlated with sst2 and DR2 expression, whereas DR2 expression correlated inversely with BIM-23206 inhibitory effects on GH secretion. In seven mixed GH-/PRL-secreting pituitary adenomas, PRL secretion was inhibited in sst5-expressing tumors by BIM-23206, but not by BIM-23120. BIM-23244 reduced PRL secretion only in adenomas expressing sst2, sst5 and DR2. sst5 and DR2 expression correlated directly with BIM23206 inhibitory effects on PRL secretion. Our results suggest that adenomas expressing DR2 are less likely to respond to clinically available SRIF analogs in terms of GH secretion inhibition. Therefore, drugs interacting also with DR2 might better control secretion of pituitary adenomas.

Acromegaly↗

PubMed2004

Diagnostic performance of a new highly sensitive thyroglobulin immunoassay.

The determination of serum thyroglobulin (Tg) is commonly used for detecting the presence of residual thyroid tissue or cancer recurrence in patients treated for differentiated thyroid cancer (DTC). The aim of the study was to evaluate the performance characteristics of a recently introduced fully automated chemiluminescent immunoassay, based on four monoclonal antibodies and which produces results in 40 min. Analytical sensitivity (0.01 micro g/l) was computed from 20 replicates of the zero calibrator and of the 'Tg-free' sample pool. Functional sensitivity (0.1 micro g/l at 20 coefficients of variation percent) was determined from the imprecision profile obtained by assaying ten serum pools. The reliability of the measurements in the low concentration range (Tg<1 micro g/l) has been checked by progressive dilution with the 'Tg-free' serum of a sample pool at 5.27 micro g/l; measured values were very close to the expected values (recovery 100-133%).Cut-off at the 99th percentile in DTC stage I 'disease-free' treated patients (n=53) was 0.16 micro g/l. Tg measurement in basal conditions during L-thyroxine suppression therapy and 5 days after recombinant human TSH stimulation was performed in 22 patients with DTC. In 80% of patients with basal Tg<0.1 micro g/l (12/15), Tg remained<0.1 micro g/l after stimulation, and in all of these Tg was<1 micro g/l. Our results have indicated the optimal analytical and clinical performance of this Tg immunoassay and encourage further studies on larger populations of patients with DTC.

Adult↗

PubMed2000

Zirconium tetrachloride-formaldehyde sigma-complexes: A computational and spectroscopic investigation

We have carried out a combined theoretical-experimental study of the structures and energies of ZrCl(4)-aldehyde complexes using (13)C NMR spectroscopy and a DFT (B3LYP) computational approach. The computational investigation has demonstrated the existence of different types of complexes: a 1:1 complex (H(2)CO-ZrCl(4)), various 2:1 complexes ((H(2)CO)(2)-ZrCl(4)), and several dimeric species. The analysis of the energies involved in the formation of the various complexes has indicated that the dimeric species should correspond to the only adduct observed in the (13)C NMR spectra (carbonyl resonance at 226.96 ppm) when a 1:1 ZrCl(4)/aldehyde molar ratio is used, while the 2:1 complex should be responsible for the signal at 224.30 ppm that is recorded when this molar ratio is 1:2.

Journal Article↗

PubMed1999

Quantum mechanical analysis of oxygenated and deoxygenated states of hemocyanin: theoretical clues for a plausible allosteric model of oxygen binding.

In this work with ab initio computations, we describe relevant interactions between protein active sites and ligands, using as a test case arthropod hemocyanins. A computational analysis of models corresponding to the oxygenated and deoxygenated forms of the hemocyanin active site is performed using the Density Functional Theory approach. We characterize the electron density distribution of the binding site with and without bound oxygen in relation to the geometry, which stems out of the crystals of three hemocyanin proteins, namely the oxygenated form from the horseshoe crab Limulus polyphemus, and the deoxygenated forms, respectively, from the same source and from another arthropod, the spiny lobster Panulirus interruplus. Comparison of the three available crystals indicate structural differences at the oxygen binding site, which cannot be explained only by the presence and absence of the oxygen ligand, since the geometry of the ligand site of the deoxygenated Panulirus hemocyanin is rather similar to that of the oxygenated Limulus protein. This finding was interpreted in the frame of a mechanism of allosteric regulation for oxygen binding. However, the cooperative mechanism, which is experimentally well documented, is only partially supported by crystallographic data, since no oxygenated crystal of Panulirus hemocyanin is presently available. We address the following question: is the local ligand geometry responsible for the difference of the dicopper distance observed in the two deoxygenated forms of hemocyanin or is it necessary to advocate the allosteric regulation of the active site conformations in order to reconcile the different crystal forms? We find that the difference of the dicopper distance between the two deoxygenated hemocyanins is not due to the small differences of ligand geometry found in the crystals and conclude that it must be therefore stabilized by the whole protein tertiary structure.

Allosteric Regulation↗

PubMed1997

Lifestyle and dietary differences in smokers and non-smokers from an Italian employee population.

In a sample of 200 subjects, representative of a population of 1936 civil servants, we tested differences in life style, dietary habits and distribution of risk factors for CHD between smokers and nonsmokers. The two groups (79 smokers) and (121 non-smokers) did not differ significantly by age or sex. The percentage of sedentary subjects, of hypercholesterolaemics and of hypertensives was found to be particularly high among smokers: 67%, 33% and 30% respectively (vs 59%, 27% and 19% in non-smokers). More smokers were obese (11% vs 5%) but mean BMI was the same in smokers/non-smokers but showed a higher fat mass; the association of CHD risk factors indicates only one significant correlation (P < 0.05) between obesity and hypertension. In male smokers, higher values of LDL and triglycerides and lower intake of energy, vitamins C and A are observed and these values are significantly different than those for non-smokers. In women HDL values are higher in non-smokers whereas, in female smokers, the food cholesterol intake is particularly high 271 +/- 295 mg. There are also correlations both for the anthropometric and clinical parameters and for energy and nutrients, indicating that the lifestyle of smokers is less healthy than that of non-smokers. Smokers cat vegetables and fruits less frequently and consume more alcohol than non-smokers, who prefer sweet foods.

Adult↗

PubMed1996

Use of benzodiazepines in the Italian general population: prevalence, pattern of use and risk factors for use.

This study was conducted to determine the prevalence and profile of use of benzodiazepines in the Italian population and risk factors for use. Between November 1992 and February 1993, 62 general practitioners submitted a validated self-administered questionnaire on health status and drug use to a randomised sample of 3100 subjects ( > or = 18 years of age, stratified by sex and age), of whom 2803 responded (response, rate 90.4%). Main outcome measures were point estimate (past-week) of all the drugs taken by each individual, dosage and length of use and source of the prescription. The overall past-week prevalence of use of benzodiazepines was 8.6% (5.0% males and 11.8% females). In the elderly ( > or = 65 years) 18.8% reported current use (9.0% males and 24.7% females). Fifty-six per cent of the persons exposed to a benzodiazepine were chronic users (daily, for more than 6 months), and 70.1% in subjects > or = 65 years. The average daily dose taken was relatively low: 61% of short-term users and 51% of chronic users used less than half a defined daily dose (DDD). Female sex, older age, unemployment and retirement were independently associated with the use of benzodiazepines. Benzodiazepine use in Italy appeared to be relatively high (about 9% of subjects reported current use 57% of whom were chronic users). Women were prescribed a benzodiazepine twice as often as men and one out of four elderly women was on treatment. Although the average dosage used was rather low, the high prevalence and the elevated proportion of chronic users should encourage drug information campaigns and educational interventions to promote a more conservative use of these drugs especially in the elderly.

Adolescent↗

PubMed1994

[Survey on antibiotic prescriptions in general medicine].

The objectives of the survey are to describe the use of antibiotics in general practice, in order to identify inappropriate use and to estimate the exposure to different antibiotic categories in the population. The data refer to the overall drug prescriptions issued in general practice during 1991 in Rome. Four million of antibiotic prescriptions were issued, corresponding to 9% of the overall drug prescriptions and to 11% of the drug expenditure in Rome. When considering all anti-infective drugs (antibiotics plus antivirals and immunostimulating agents) the prescriptions and the expenditure increase up to 13% and 18% respectively. Three therapeutic categories (penicillins, cephalosporins and macrolides) represent more than 50% of the antibiotic prescriptions. Among the general population, 34% received at least one anti-infective drug and each patient received on average 2.7 prescriptions during the year. More than 20% of the prescriptions refers to antibiotic categories (such as aminoglycosides and chloramphenicols) which are not considered as a first choice in general practice. The analysis shows that a considerable proportion of antibiotic prescriptions refers to therapeutic categories with negative benefit/risk profile. More appropriate use of antibiotics might reduce both adverse events and drug expenditure.

Anti-Bacterial Agents↗

PubMed1992

Cutaneous adverse reactions following the administration of nonsteroidal antiinflammatory drugs and antibiotics: an Italian survey.

The Italian Group for Epidemiological Research in Dermatology (GISED) collected a series of cutaneous adverse reactions following NSAID and/or antibiotics administered by topical and/or systemic route. Dermatologists from North and Central Italy took part in this survey by filling in 1457 case report forms during a four-month observation time in 1988-89. The main purpose of our epidemiological study aimed at evaluating a post-marketing surveillance program by examining spontaneous reports of cutaneous adverse reactions. This result seems to be noteworthy, considering the difficulties encountered in Italy to develop such a program.

Adolescent↗

PubMed1987

Multiple meningiomas evaluated by computed tomography.

The authors report ten cases of multiple meningiomas in a series of 227 intracranial meningiomas from 1977 to 1984. The incidence of multiple meningiomas was 4.4% (according to Cushing and Eisenhardt's [1938] concept of "multiplicity" of such tumours). These results are comparable to those obtained by other authors. All patients were females and all underwent CT scan before operation. Clinical symptoms are presented along with location and size of the tumours. Pathogenetic theories and research prospects are discussed.

Adult↗

PubMed1982