Biomedical subjects

A Paladini

Publications and source records attributed to A Paladini.

At least 19 recordsLinked to original sources

PubMed2006

Modelling neurotransmitter functions: a laser spectroscopic study of (1S,2S)-N-methyl pseudoephedrine and its complexes with achiral and chiral molecules.

Wavelength and mass resolved resonance-enhanced two photon ionization (R2PI) excitation spectra of (1S,2S)-N-methyl pseudoephedrine (MPE) and its complexes with several achiral and chiral solvent molecules, including water (W), methyl (R)-lactate (L(R)), methyl (S)-lactate (L(S)), (R)-2-butanol (B(R)), and (S)-2-butanol (B(S)), have been recorded after a supersonic molecular beam expansion and examined in the light of ab initio calculations. The spectral patterns of the selected complexes have been interpreted in terms of the specific hydrogen-bond interactions operating in the diastereomeric complexes, whose nature in turn depends on the structure and the configuration of the solvent molecule. The obtained results confirm the view that a representative neurotransmitter molecule, like MPE, "communicates" with the enantiomers of a chiral substrate through different, specific interactions. These findings can be regarded as a further contribution to modelling neurotransmitter functions in biological systems.

Butanols↗

PubMed2006

[Bacterial meningitis in adults: a retrospective multicentric study in Tuscany (Italy)].

The Infectious Diseases Unit of Lucca Hospital conducted a multicentric retrospective study to evaluate the epidemiological and clinical features of adult patients affected by bacterial meningitis attending all the Infectious Diseases Units of Tuscany (Italy) from July 1999 to June 2004. A specific questionnaire was sent to all the units to collect information about each case of bacterial meningitis occurring in patients older than sixteen. Patients with meningitis by Mycobacterium tuberculosis were excluded from the analysis. Nine out of 12 Infectious Diseases Units of Tuscany took part in the study and 197 cases were identified. Most cases of meningitis occurred during 2002 with a slight reduction in cases in subsequent years. Streptococcus pneumoniae and Neisseria meningitidis were the most frequently isolated pathogens with an increase in diagnosis from 1999 to 2004; in 23.8% of patients no pathogens were isolated, with a reduction in meningitis from unknown aetiology from 1999 to 2004. Most patients were treated with a combination of two antibiotics, and corticosteroid drugs were added to the therapy; in the group of patients treated with corticosteroid drugs invalidating complications occurred in 23% of cases and 5% of patients died. In all, 27 out of 197 subjects (13.7%) developed invalidating complications and 20 out of 197 patients (10.2%) died.

Adolescent↗

PubMed2005

Chiral clusters in a supersonic beam: R2PI-TOF spectroscopy of diastereomeric carboxylic esters/(R)-(+)-1-phenyl-1-propanol complexes.

Wavelength and mass resolved resonance-enhanced two photon ionization (R2PI) excitation spectra of (R)-(+)-1-phenyl-1-propanol (P(R)) and its complexes with some chiral esters, i.e. methyl lactates (L(R) and L(S)), methyl 3-hydroxybutyrates (H(R) and H(S)), and methyl 2-chloropropionates (C(R) and C(S)), have been recorded after a supersonic molecular beam expansion and interpreted in the light of DFT calculations. The spectral features of the selected complexes were found to depend on the nature of hydrogen-bond interactions within the diasteromeric complexes, whose intensity in turn depends upon the structure and the configuration of the estereal moiety. The study further confirms resonant two-photon ionization spectroscopy, coupled with time-of-flight mass resolution (R2PI-TOF), as an excellent tool for gathering valuable information on the interactive forces in molecular clusters and for the enantiodiscrimination of chiral molecules in the gas phase.

Esters↗

PubMed2004

Hemodynamic variations during thoracic and abdominal stop-flow regional chemotherapy.

AIMS: The aim of this study was to study hemodynamic modifications during thoracic and abdominal stop-flow regional chemotherapy and to evaluate the need for routine hemodynamic monitoring during such kind of procedures. METHODS: Thirty patients, aged 17-67 years, ASA physical status II-III, scheduled for thoracic (group A, n = 15), and abdominal (group B, n = 15) stop-flow regional chemotherapy were enrolled. Heart rate (HR), electrocardiogram lead I and V(5), end tidal carbon dioxide (ETCO(2)), arterial oxygen saturation (SaO(2)), systolic, diastolic and mean arterial pressure (SBP, DBP, MAP), mean pulmonary arterial pressure (MPAP), pulmonary capillary wedge pressure (PCWP), central venous pressure (CVP), cardiac output (CO), stroke volume (SV), stroke index (SI), systemic vascular resistance (SVR), pulmonary vascular resistance (PVR), left cardiac work (LCW), right cardiac work (RCW), left cardiac work index (LCWI), right cardiac work index (RCWI), cardiac index (CI), and body O(2) consumption (VO(2)) were recorded. RESULTS: After aortic and inferior vena cava endovascular occlusion (T(1)), a significant reduction of CO and SV, associated with an increase of CVP, MAP, PAPM and PCWP were observed. A concomitant reduction of CI and increase of SVR and PVR were registered. The VO(2) was significantly reduced compared to basal values in both groups. After deflating aortic and vena cava balloons (T(2)), CO, SV and CI increased with respect to basal value p < 0.05) whereas MAP, CVP, PAPM, PCWP and calculated parameters (SVR, PVR) showed a significant reduction compared to T(1). The oxygen consumption was significantly higher than that of basal values p < 0.05. After hemofiltration (T(3)), all hemodynamic variables were comparable with the basal values. Modifications of direct and calculated parameters, during the stop-flow period, showed a similar trend in both study groups, without any statistically significant difference. No ST modifications at ECG were noted during all perioperative period. CONCLUSIONS: The results of this study have confirmed in both groups, the safety of stop-flow regional chemotherapy procedure, despite endovascular occlusion of the aorta and inferior cava vein. The hemodynamic and oxygenation changes are reversible and did not produce any ST modifications at ECG during all perioperative period. Routine pulmonary artery catheterization is thus unnecessary, except in high cardiac risk patients.

Adolescent↗

PubMed2004

[Possible and proved benefits of peridural analgesia].

Regional anesthesia is supposed to be of some help in improving the outcome of surgical patients. Actually this assumption is largely accepted, even if clear scientific demonstrations have not been obtained. At present there are data showing the advantages, as to survival and complications, especially for major orthopedic surgery. These data have been shown by important and clarifying meta-analyses. Unfortunately, for other types of surgery, advantages have been scarcely demonstrated, due to the low number of patients involved in clinical trials. Anyway, it is underlined that regional anesthesia, and especially epidural block, is much more convenient for the patients than general anesthesia. It seems also convenient from the economic point of view, since the pharmaco-economic studies present in the literature showed the possibility to save money, using regional anesthesia and regional analgesia.

Analgesia↗

PubMed2002

Chiral discrimination of 2,3-butanediols by laser spectroscopy.

The resonance enhanced two-photon ionization time-of-flight (R2PI-TOF) excitation spectra of supersonically expanded complexes of isomeric 2,3-butanediols with a suitable chromophore, i.e. R-(+)-1-phenyl-1-propanol, represent powerful means for structurally discriminating the diol moiety and for investigating the nature of the intra- and intermolecular interactions involved in the complexes.

Journal Article↗

PubMed2001

R2PI Study of intermolecular hydrogen bond in solvent-free chiral complexes.

One- and two-color, mass selected R2PI spectra of the S(1)<--S(0) transitions in the bare (+)-(R)-1-phenyl-1-ethanol (E(R)) and its complexes with different solvent molecules (solv) (-)-(R)-2-butanol (B(R)) or (+)-(S)-2-butanol (B(S)) and (-)-(R)-2-butylamine (A(R)) or (+)-(S)-2-butylamine (A(S)), have been recorded after a supersonic molecular beam expansion. The one-color R2PI excitation spectra of the diastereomeric complexes are characterized by significant shifts of their band origin relative to that of bare E(R). The extent and the direction of these spectral shifts are found to depend on the structure and the configuration of solv and are attributed to different short-range interactions in the ground and excited states of the complexes. In analogy with other diastereomeric complexes, the phenomenological binding energy of the homochiral cluster is found to be greater than that of the heterochiral one.

Journal Article↗

PubMed2001

Enantiodiscrimination of chiral alpha-aminophosphonic acids by mass spectrometry.

Diastereomeric clusters between first-group metal ions (M(+)) and chiral alpha-aminophosphonic acids (A and B) have been readily generated in the gas phase by electrospray ionization (ESI) and their fragmentation investigated by mass spectrometry. The complexes studied had the general formula [MA(S)B(2)](+) and [MA(R)B(2)](+), where M = H, Li, Na, or K, A(S) and A(R) are the two enantiomers of a given acid A, and B is a reference alpha-aminophosphonic acid of defined configuration. Collision-induced decomposition (CID) of [MA(S)B(2)](+) and [MA(R)B(2)](+) leads to fragmentation patterns characterized by [MAB](+)/[MB(2)] abundance ratios which depend on the configuration of ligand A. These different spectral features were correlated to the different stability of the diastereomeric [MA(S)B(2)](+) and [MA(R)B(2)](+) complexes in the gas phase. The results have been discussed in the light of MM2 Molecular Mechanics Force Field calculations.

Journal Article↗

PubMed2000

Haemodynamic effects of intravenous clonidine on propofol or thiopental induction.

The study evaluated the effects of premedication with intravenous clonidine on thiopental or propofol requirements for induction and haemodynamic changes associated with both induction and endotracheal intubation. Clonidine administered intravenously before induction of anaesthesia reduced propofol or thiopental requirements. The association of clonidine and propofol caused, after injection of the induction drug, a decrease in mean arterial pressure which was significantly greater than with thiopental. Moreover, a major haemodynamic stability was registered before and after laryngoscopy in the clonidine-thiopental group. These findings might contraindicate the clonidine-propofol combination in patients with cardiovascular disease.

Adrenergic alpha-Agonists↗

PubMed1998

Pharmacological characterization of 6-bromo-3'-nitroflavone, a synthetic flavonoid with high affinity for the benzodiazepine receptors.

6-Bromo-3'-nitroflavone is a synthetic flavone derivative that selectively recognizes benzodiazepine receptors and has potent anxiolytic-like effects. Here, we describe in detail its pharmacological characterization. When i.p. injected in mice, 6-bromo-3'-nitroflavone (0.01-0.3 mg/kg) had an anxiolytic-like effect in the elevated plus-maze test. This effect was blocked by the specific benzodiazepine receptor antagonist, flumazenil. In addition, it exhibited anxiolytic-like actions when given orally (1 mg/kg). 6-Bromo-3'-nitroflavone did not exhibit myorelaxant effects (up to 30 mg/kg, i.p.). Unlike diazepam, this flavonoid produced no anterograde amnesia in a one-trial inhibitory avoidance learning. On the other hand, 6-bromo-3'-nitroflavone possessed mild anticonvulsant activity (0.1 mg/kg, i.p.) and provoked sedative-depressant actions only at doses 100-1000 times higher than those producing anxiolytic-like effects. 6-Bromo-3'-nitroflavone (0.1-1 mM) produced a lower potentiation of gamma-amino-butyric acid (GABA)-stimulated 36Cl- influx (126-138%) in comparison to diazepam (0.1 mM: 166%) in cerebral cortical membrane vesicles. Taken together, these findings suggest that 6-bromo-3'-nitroflavone has anxiolytic-like action possibly behaving as a partial agonist of the benzodiazepine receptors.

Animals↗

PubMed1997

Hormonal influence on lipid-protein interactions in biological membranes. Lactation effects on alkaline phosphatase activity and intestinal brush border membrane properties in rat.

It is known that prolactin modifies the fluidity of different biological membranes in rats and that the activity of intestinal alkaline phosphatase varies directly with the fluidity of the membranes in which it is found. Our objective was to study the intestinal alkaline phosphatase (IAP) activity, lipid composition and fluidity of the proximal small intestine brush border membranes under the influence of physiological high levels of prolactin, in rats with 15 days of lactating (Dams 15 days) compared with control virgin rats. The phenomenon was corroborated in dams from which the suckling pups had been withdrawn on the tenth day of lactation (Dams 10 days). The results showed a decrease on the IAP activity in dams in lactation with relation to control virgin and dams with withdrawal of pups. We found decreases in total phospholipids contents and fluidity and an increase in the microviscosity lipid membrane in dams with 15 days of lactating compared to virgins. In the same groups there were no differences in total lipids content and no modifications were observed in the quantity of total cholesterol and proteins. These results suggest that the changes produced by lactation could be one of the causes of alteration of brush border membranes properties by modifying the lipid-protein interactions and the alkaline phosphatase activity in the proximal small intestine.

Alkaline Phosphatase↗

PubMed1997

Influence of goserelin depot therapy on epidermal growth factor receptor expression in pelvic endometriosis.

We have studied epidermal growth factor (EGF) receptor expression in endometrium and in endometriotic implants, testing a group of 36 women before and after a 4-month gonadotropin-releasing hormone (GnRH) analog (GnRH-a) goserelin depot treatment. Each woman underwent laparoscopy twice. At the initial laparoscopy, before starting treatment, the disease was staged according to the American Fertility Society (AFS) classification and biopsies of endometriotic implants were undertaken. The follow-up laparoscopy was performed within 5 weeks of the last GnRH-a administration. Biopsies were taken from areas of previously noted disease, both visually persistent and visually free of disease. At the time of each laparoscopy, photographs of all areas of disease were taken. Specimens of eutopic endometrium were collected from each patient at the time of laparoscopy by a Novak curette. Endometrial and endometriotic samples were processed for immunohistochemical detection of EGF receptor, using anti-EGF receptor monoclonal antibody Ab-3. After treatment, the marked improvement of AFS score was associated with a dramatic reduction of EGF receptor immunostaining, but the exact meaning of this finding is still not completely understood. The dramatic reduction of EGF receptor expression in eutopic and ectopic endometrium samples after treatment is not obviously related to the hypoestrogenism induced by the drug. It has been suggested that steroid hormones and EGF play a role in regulation of EGF receptor expression, so that drugs such as goserelin depot could act directly at local peripheral level influencing the EGF receptor expression via the production of its ligand.

Adult↗

PubMed1997

[Measurement of cardiac output with continuous thermodilution. b1 Clinical experience with the Intellicath-Vigilans system].

BACKGROUND: Thermodilution cardiac output measurements are commonly obtained by a manual bolus technique with a pulmonary artery catheter. METHODS: A new thermodilution catheter has been developed which utilizes an integral thermal filament and provides semicontinuous online cardiac output. The response of this new device in 25 patients undergoing coronary artery bypass grafting was examined. A total of 250 data pairs was obtained; the cardiac outputs ranged from 2.2 to 11.9 lts.min. RESULTS: The linear regression is represented by the following equation: continuous thermodilution = 0.7196 bolus thermodilution +1.038. The correlation coefficient was 0.75; the mean bias was 0.493 +/- 1.034. CONCLUSIONS: The new technique provides acceptable accuracy in many clinical situations except when sudden haemodynamic changes occur.

Cardiac Output↗

PubMed1996

[Retrospective study of postoperative infectious morbidity following cesarean section].

The increase of cesarean sections produced more postoperative infections. Several authors assessed the effectiveness of chemioantibiotic prophylaxis to reduce the postoperative infective morbidity. Although the family of antibiotics more frequently used is that of cephalosporin, the best single agent has not been found yet. The aim of our study, made in the Department of Obstetrics and Gynecology of University of Naples "Federico II", is to propose a retrospective analysis concerning the incidence of cesarean section (CS), the postoperative infective morbidity and the employment of antibiotic prophylaxis. Our sample is a group of 13285 pregnant women, 3171 (23.9%) of these patients underwent to CS from 1st January 1985 to 31st December 1994. The group of 3171 women was divided in two subgroups, the first of 2748 patients un-derwent to antibiotic prophylaxis, the second of 423 was untreated due to their previous experience of allergy towards antibiotics or because there was no evidence of risk factors. The women we treated with antibiotics underwent a three days prophylactic therapy with cefazolin or ampicillin soon after the CS. The incidence of infective complications had a 21.2% rate over a total of 3171 women. Endometritis was the most common infectious complication following cesarean delivery. The rate was 53.3% in the case of primary cesarean section and 52.3% in the case of iterative cesarean section. The use of antibiotic prophylaxis gave us the opportunity to reduce the postoperative morbidity in the primary CS (23.4%) as well in the iterative CS (16.6%). On the contrary the untreated group had an infective incidence with a 33.8% rate in the case of primary CS and with a 27.4% rate in the case of iterative CS. Our opinion is that the administration of antibiotics as cefazolin and ampicillin is able to reduce in a significant way the incidence of postoperative infective morbidity as well the period of hospitalization.

Adult↗

PubMed1996

EGF/EGF-R system and benign breast disease during and following the treatment of gynaecological pathologies with an analogue of LH-RH.

Clinical and pathological changes of the mammary gland have been studied in 64 women affected by symptomatic Benign Breast Disease (BBD) coexisting with endometriosis or uterine leiomyomata. These patients were rendered hypoestrogenic by subcutaneous administration of the LH-RH analogue Goserelin depot [D-ser (tBu)6 Aza-Gly10-GnRH (ICI118630)] performed every 28 days, for six months. They were evaluated clinically and ultrasonographically before and after treatment to find possible changes of BBD as well as of endometriosis or uterine leiomyomata. Mammary biopsies were performed before and after treatment in all the patients to study the changes of EGF-R expression. Results showed that clinical improvement is accompanied with a reduction of EGF-R expression.

Antineoplastic Agents, Hormonal↗

PubMed1995

Molecular typing of Candida albicans in oral candidiasis: karyotype epidemiology with human immunodeficiency virus-seropositive patients in comparison with that with healthy carriers.

Candida albicans organisms isolated from the oral cavities of healthy carriers (26 individuals) and compromised hosts (40 human immunodeficiency virus [HIV]-seropositive patients, all showing symptomatic oral candidiasis) were compared by resolving chromosome-sized DNA molecules into electrophoretic karyotypes. Seven- to 10-band electrophoretic patterns were obtained, with significant and reproducible differences in the distributions of the DNA bands. Seven distinct classes were identified and were designated type a (8 bands), type b (8 bands), type c (7 bands), type d (9 bands), type x (10 bands), type y (10 bands), and type z (9 bands). Four of these (types a to d) were the most representative within all of the isolated strains (95.5%), and the other three (types x to z) were observed only once in three HIV-seropositive individuals (4.5%). Only types b and c were isolated from healthy carriers, with the percentage of their isolation being 61.5 and 38.5%, respectively, while all the described karyotypes were isolated from HIV-seropositive patients, with type b being the most frequent (45%); this was followed by types c (25%), a (15%), and d (7.5%). The prevalence of type b and c karyotypes in HIV-infected individuals, as well as in healthy carriers, suggests that commensal strains in the oral cavities of healthy individuals may become the prevalent agents of subsequent oral candidiasis in compromised hosts. However, replacement of the original, commensal strain, if there is one, cannot be excluded in a compromised host, although strain replacement may be more reasonably hypothesized for types a and d, since only these types were isolated at a relative high percentage from the oral lesions of HIV-infected individuals.

AIDS-Related Opportunistic Infections↗

PubMed1994

Desogestrel versus gestodene in oral contraceptives: influence on the clinical and histomorphological features of benign breast disease.

Forty-four female volunteers asking for oral contraception, affected by symptomatic benign breast disease (BBD) were evaluated to compare the effects on mastalgia and breast nodularity of two different low dose oral contraceptives (OCs), containing 20 micrograms [corrected] ethinylestradiol + 150 micrograms desogestrel (EE+D) and 30 micrograms ethinylestradiol + 75 micrograms gestodene (EE+G), respectively. Physical examination, bilateral thermography, X-ray and/or ultrasonography of breast, and needle and screw-needle biopsies of mammary tissue were performed in all patients before OCs administration and after six cycles of treatment. OCs administration caused an overall improvement of mastalgia in 53%. Breast nodularity improved only in 8% of patients in both groups. Epithelial tissue modifications in mammary biopsies were observed, with involutive and/or secretory histomorphological and ultrastructural changes, frequently coexisting in different areas of the same breast.

Adolescent↗

PubMed1994

Possible anxiolytic effects of chrysin, a central benzodiazepine receptor ligand isolated from Passiflora coerulea.

The pharmacological effects of 5,7-dihydroxyflavone (chrysin), a naturally occurring monoflavonoid that displaces [3H]flunitrazepam binding to the central benzodiazepine (BDZ) receptors, were examined in mice. In the elevated plus-maze test of anxiety, diazepam (DZ, 0.3-0.6 mg/kg) or chrysin (1 mg/kg) induced increases in the number of entries into the open arms and in the time spent on the open arms, consistent with an anxiolytic action of both compounds. The effects of chrysin on the elevated plus-maze was abolished by pretreatment with the specific BDZ receptor antagonist Ro 15-1788 (3 mg/kg). In the holeboard, diazepam (1 mg/kg) and chrysin (3 mg/kg) increased the time spent head-dipping. In contrast, high doses of DZ (6 mg/kg) but not of chrysin produced a decrease in the number of head dips and in the time spent head-dipping. In the horizontal wire test, diazepam (6 mg/kg) had a myorelaxant action. In contrast, chrysin (0.6-30 mg/kg) produced no effects in this test. These data suggest that chrysin possesses anxiolytic actions without inducing sedation and muscle relaxation. We postulate that this natural monoflavonoid is a partial agonist of the central BDZ receptors.

Animals↗