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Biomedical subjects

A Ricci

Publications and source records attributed to A Ricci.

At least 235 records · Page 13Linked to original sources
PubMed1990

Immunological pattern in heterozygote beta thalassemic subjects.

In heterozygote beta-thalassemic subjects in a higher incidence of infectious diseases and of liver diseases with progression toward chronic hepatitis has been assessed. This predisposition has been suggested as being related to some immunological defects and to an altered immunological reactivity in thalassemia trait carriers. In order to evaluate whether there is a real deficiency of some humoral and cellular parameters in healthy heterozygote beta-thalassemic subjects, 128 symptom-free volunteers have been studied: 40 were heterozygote beta thalassemia carriers and 88 were normal subjects. In both groups there was no difference in: number and percentage of total lymphocytes, gamma globulins, immunoglobulins A and M, number and percentage of CD21, CD3, CD4, CD8, number of OKla*1, CD4/CD8 rations and lymphocytes' ability to respond to phytohemagglutinin. The values of immunoglobulins G and percentages of OKla*1 were found to be higher only in heterozygote beta thalassemic subjects; however, the number of CD2 in these subjects was lower. The result of the present study seems to indicate there is not significant difference between heterozygote beta thalassemic carriers and normal subjects in the more usual humoral and cellular immunological parameters.

Adult↗
PubMed1990

Autoradiographic localization of dopamine DA-2 receptor sites in rat mesenteric vascular tree.

By using combined in vitro radioreceptor binding and autoradiographic techniques and [3H]spiroperidol (in the presence of the 5-hydroxytryptamine-2 receptor blocker ketanserin) as a ligand, the pharmacological properties and the anatomical localization of dopamine (DA) DA-2 receptors sites in rat mesenteric vascular tree were analyzed. [3H]Spiroperidol was bound by sections of rat mesentery in a manner consistent with the labeling of DA-2 receptors, with a Kd value of 2.48 nM and with a maximum binding value of 159 fmol/mg of protein. Light microscopic autoradiography revealed specific [3H]spiroperidol binding sites primarily in the adventitial layer and in the adventitial-medial border as well as in the intimal layer. Adventitial and adventitial-medial binding sites disappeared after 6-hydroxydopamine sympathectomy. In contrast, chemical sympathectomy was without effect on intimal [3H]spiroperidol binding sites. The density of adventitial and adventitial-medial binding sites was higher in medium and small sized vessels than in larger ones. These findings are indicative of the existence of DA-2 receptors sites located both prejunctionally (6-hydroxydopamine-sensitive) and in the intimal layer. Prejunctional mesenteric DA-2 receptors may be involved in the inhibition of noradrenaline release from sympathetic neuroeffector junctions. The functional significance of intimal [3H]spiroperidol binding sites, if any, should be established in future studies.

Animals↗
PubMed1990

Pharmacological characterization of rat renal medulla dopamine-sensitive cyclic adenosine monophosphate generating system.

The dopamine (DA) DA-1 and DA-2 receptors coupled to 3'-5'-cyclic adenosine monophosphate (cAMP) generating system were characterized in membrane particles of the rat kidney medulla. In confirmation of reports using central and other peripheral tissues, activation of DA-1 receptors with DA, apomorphine or SKF 82526 induced accumulation of cAMP. This effect was blocked by the DA-1 receptors antagonist SCH 23390 and by the other DA-2 receptor antagonists fluphenazine and haloperidol. DA-2 receptor responses coupled negatively to the cAMP generating system were obtained by incubating renal medulla membrane particles with DA or SKF 82526 together with SCH 23390. DA-2 receptor responses were also elicited with the receptor agonists quinpirole and bromocriptine in the absence of SCH 23390. These inhibitory effects on cAMP generation were abolished by the DA-2 receptor antagonist l-sulpiride. Our findings suggest that rat renal medulla contains DA DA-1 and DA-2 receptors similar to those found in brain and in other peripheral tissues. The physiological significance of these receptors, if any, should be established in future studies.

Animals↗
PubMed1990

New heterocyclic derivatives of benzimidazole with germicidal activity--VII--2-(5'-nitro-2'-furyl or 2'-thienyl) benzimidazoles with different substituents in the 5-position.

In continuation of our previous research, the synthesis of 13 2-(5'-nitro-2'-furyl or 2'-thienyl) benzimidazoles with different substituents in 5 position is described. The new compounds were tested in vitro against 5 (Gram+) and 4 (Gram-) strains and a mycete Candida Albicans. All the derivatives showed a certain degree of antibacterial and antimycotic activity, which in some cases was fairly good.

Anti-Bacterial Agents↗
PubMed1990

Synthesis of 1-O-alkyl-2-O-methyl-glycerophospholipids with potential antitumor activity.

Some synthetic alkyl-lysophospholipid analogs have been described as a new class of immunopotentiating and antitumor agents. Among them, 1-O-octadecyl-2-O-methyl-rac-glycero-3-phosphocholine has been reported to possess the highest antitumor activity. A new method for the synthesis of this compound and of the ethanolamine- and serine-containing analog is reported. 1-Alkyl-2-methyl-rac-glycerol, prepared from 1,2-isopropylidene-glycerol, is phosphorylated and the intermediate is condensed either with N-t-BOC-protected ethanolamine or with N-t-BOC-protected serine benzhydryl ester. The choline-derivative is obtained by methylation with CH3I of the ethanolamine derivative. The same synthetic sequence has been used also for synthesizing compounds unsaturated at the fatty alkyl chain in position 1 of the glycerol moiety. Preliminary observation are reported on the selective cytolytic action of the compounds on a tumor cell line.

Animals↗
PubMed1990

[Heterozygote beta-thalassemia and neoplastic pathology].

To evaluate the possible correlation between heterozygote beta thalassemia (BTE) and neoplastic disease, a 5-year personal experience of clinically followed patients at Comacchio Hospital Internal Medicine and Surgery divisions is presented. The hemoglobin A2 was assayed in all patients whose medial corpuscular volume was lower than 80 fl. 589 consecutive neoplastic patients were evaluated; of these 73 were BTE. In the BTE patients the prevalence of neoplastic disease was 12.39% higher than in healthy people (8.8%, chi 2 = 8.79 and p = 0.03). In thalassaemic carriers the titres of medial annual incidence to 10,000 for neoplastic diseases were proved to be ever higher (46.08 versus 31.49/10,000). The incidence of gastric cancer was found to be greater in BTE than in non-trait carrier population (13 in 63 patients, with a 20.63% prevalence, chi 2 = 9.52 and p = 0.02). A higher prevalence of thalassaemic carriers was observed among subjects with cancer in different organs: larynx, oesophagus, gallbladder and bile ducts, pancreas, breast and kidney, but these differences were not statistically significant. As for various sites of cancer: lung, liver, uterus and ovary, bladder, prostate, skin, lymphomas, leukaemias and gammopathies, no difference in BTE prevalence was found. We conclude that a greater predisposition to neoplastic disease can be present in BTE than in healthy population.

Age Factors↗
PubMed1990

Chemometric approach in a QSAR study: the antibacterial and antimicotic activities of benzofused heteroaromatic derivatives.

In order to establish quantitative relationships between the antibacterial activities of a number of thienyl- and furyl-benzimidazoles and benzoxazoles, the biological data were measured homogeneously for a selected set of 16 representative compounds of the available set of 103. The data were analyzed by the PLS method. The results of linear PLS modelling and PLS response surface modelling permitted a straightforward interpretation of the structural features relevant to the activities and the prediction of a possible optimal structure.

Anti-Bacterial Agents↗
PubMed1989

Clinical and pathologic prognostic variables in oropharyngeal squamous cell carcinoma.

Eighty-five patients with squamous cell carcinoma of the oropharynx were studied to assess the value of histopathologic parameters related to their survival. The overall survival was 58 percent at 3 years and 51 percent at 5 years. Stepwise logistic regression analysis was used to determine the prognostic value of each of the histopathologic features. The extent of in situ carcinoma and presence of multifocality were positive predictors of survival, and perineural invasion and nodal involvement on clinical examination were negative predictors. None of the other parameters used in this study attained statistical significance. We conclude that the histologic grade traditionally used to predict clinical behavior may not be useful. Clinical stage, particularly nodal status; perineural invasion; and the multifocal or in situ disease, should be considered in pathologic reports to provide better prognostic profile in oropharyngeal carcinoma.

Carcinoma, Squamous Cell↗
PubMed1989

Autoradiographic localization of vasoactive intestinal polypeptide receptors in the rat mesenteric vascular tree.

By the use of combined in vitro radioreceptor binding and autoradiographic techniques, we analyzed the pharmacological properties and the anatomical localization of the vasoactive intestinal polypeptide (VIP) receptor in rat superior mesenteric artery and in medium and small mesenteric artery branches. 125I-VIP was bound by sections of rat superior mesenteric artery in a manner consistent with the labeling of specific VIP receptors, with Kd and Bmax values of 0.23 nM and 0.71 pmol/mg protein respectively. Inhibition of 125I-VIP binding with VIP and related peptides gives the following rank order of potency: VIP greater than peptide histidine methionine greater than secretin. Light microscope autoradiography reveals specific VIP binding sites within the medial layer of superior mesenteric artery and its branches. Medium and small sized vessels are richer in 125I-VIP binding sites than the larger ones.

Animals↗
PubMed1989

Age-related changes of the mossy fibre system in rat hippocampus: effect of long term acetyl-L-carnitine treatment.

Age-related changes of the hippocampal mossy fibre system were studied in rats of different ages (4, 12, and 24 months) using the Timm's histochemical technique for the detection of tissue stores of zinc and heavy transitional metals. Quantitative image analysis and microdensitometry techniques were applied for the evaluation of the changes themselves. The area occupied by mossy fibres and the intensity of Timm's staining in field CA3 of hippocampus were greater in adult rats than in young and old animals. These findings are consistent with previous behavioural data indicating that young and old rats exhibited a reduced passive avoidance learning with respect to adult animals. The above techniques were also used in a second session of this study designed to investigate the effect of a 6-months treatment with acetyl-L-carnitine (ALC) on the hippocampal mossy fibre system. ALC was found to increase significantly the area occupied by mossy fibres and the intensity of Timm's staining in the hippocampus of old rats. These findings are in agreement with and support from an anatomical point of view, the data indicating that long-term treatment with ALC improves passive avoidance performance.

Acetylcarnitine↗
PubMed1989

Acalculous cholecystitis in Crohn's disease.

A 15-year-old boy with Crohn's ileocolitis developed marked gallbladder enlargement. Ultrasonographic findings were consistent with acalculous cholecystitis (AAC) or hydrops. At laparotomy a gangrenous gallbladder was found. The diagnostic modalities currently used to distinguish between hydrops, a benign condition generally treated expectantly, and AAC, a potentially life-threatening condition requiring surgical treatment are reviewed. Failure to distinguish between these two conditions with acalculous gallbladder enlargement and similar clinical and radiologic features may have serious consequences.

Acute Disease↗
PubMed1989

Objective evaluation of gallopamil in patients with chronic stable angina. Exercise testing, Holter monitoring, cross-sectional echocardiography and plasma levels.

In this double-blind, randomized placebo-controlled study the effects of two dosages of gallopamil on exercise tolerance were evaluated in 12 patients with stable effort angina. After a pre-study screening aimed at assessing the reproducibility of the exercise response, the patients entered the study which consisted of three 7-day consecutive periods during which placebo or gallopamil 50 mg t.i.d. or gallopamil 75 mg t.i.d. were administered according to a randomized sequence. 24-hour Holter monitoring and cross-sectional echocardiography were performed on the 6th and 7th day of each treatment period, respectively. On the 7th day of each treatment period, patients underwent an exercise test 2 and 8 h after the last administration of gallopamil or placebo. Blood samples for plasma gallopamil concentrations were taken just before each exercise test. The results were analysed using a three-way analysis of variance; intergroup differences were evaluated by the Newman-Keuls test. At 2 h, 11 patients with placebo and three with gallopamil experienced angina; both dosages of gallopamil significantly prolonged exercise time and -1 mm time and also reduced ST segment depression and the rate-pressure product at submaximal workload. No significant change in the rate-pressure product was observed either on the appearance of 1 mm ST depression or at peak exercise. At 8 h, 11 patients with placebo and gallopamil 50 mg t.i.d. and 10 with gallopamil 75 mg t.i.d. experienced angina; although exercise time was significantly prolonged by both dosages of gallopamil, the increase in -1 mm time and reduction of ST segment depression at submaximal workload did not reach statistical significance.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1989

Evidence from functional and autoradiographic studies for the presence of tubular dopamine-1 receptors and their involvement in the renal effects of fenoldopam.

Evidence from receptor-ligand binding and biochemical studies seems to suggest the possible existence of tubular dopamine DA-1 receptors in the rat kidney. However, it is not yet clear whether these putative tubular DA-1 receptors are involved in the functional renal responses elicited during the administration of DA and DA receptor agonists. In the present study we have examined the renal effects of several doses of selective DA-1 receptor agonist fenoldopam in pentobarbital-anesthetized rats in an attempt to unmask a direct tubular DA-1 receptor-mediated diuresis and natriuresis. Additionally, we have performed receptor-ligand binding and autoradiographic studies to examine the presence and localization of DA-1 receptors in various regions of the rat kidney. At the highest dose studied (2 micrograms/kg/min), fenoldopam produced diuresis and natriuresis, which was accompanied by a significant decrease in blood pressure and also a significant increase in glomerular filtration rate. At 1 micrograms/kg/min, the diuretic and natriuretic effects of fenoldopam were observed in the absence of any changes in blood pressure and glomerular filtration rate, but there was a significant increase in renal blood flow. However, at 0.5 micrograms/kg/min, fenoldopam-induced natriuresis and diuresis was not accompanied by any changes in blood pressure, renal blood flow or glomerular filtration rate, implying a direct tubular effect. These effects of fenoldopam appear to be mediated via activation of DA-1 receptors, because they were antagonized by the selective DA-1 antagonist SCH 23390.(ABSTRACT TRUNCATED AT 250 WORDS)

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗
PubMed1989

[Uric acid analysis in thalassemia trait carriers].

The results of a uric acid analysis on Beta Thalassaemia Heterozygotes compared with healthy or microcytic non Beta Thalassaemia Heterozygotes are reported. Identical uric acid levels, higher than in the control group, were found in Beta Thalassaemia Heterozygotes: therefore the difference does not appear to be specific for thalassaemic carriers but consequent to increased erythrocytic catabolism in microcytic anemias.

Anemia↗
PubMed1989

[Acute effects of propionyl-L-carnitine on anomalies of parietal kinetics of the left ventricle induced by atrial pacing in patients with ischemic heart disease. A bidimensional echocardiographic study].

This double-blind randomized placebo (PL) controlled study was undertaken to evaluate, by 2D echo transesophageal atrial pacing (TAP), the effects of acute iv administration of a new compound propionyl-L-carnitine (PLC) on atrial pacing (AP) induced left ventricular wall motion abnormalities. Twelve male patients with coronary artery disease and normal regional motion at rest, after a preliminary 2D echo-TAP, on the eight and thirteenth day of trial were subjected to 2D echo-TAP 30 min after iv administration of 15 mg/Kg PLC or PL. For analysis, the left ventricle was divided into 11 segments. A wall motion score (WMS), evaluated at 130 b/min and at 150 b/min, was derived by adding together the scores assigned to each segment. Wall motion was graded +2 (normokinetic), +1 (hypokinetic), 0 (akinetic), -1 (dyskinetic). Left ventricular ejection fraction (EF) was evaluated at rest and at 150 b/min. Statistical analysis of the results was performed using a 2-way analysis of variance. The WMS at 130 b/min improved significantly after PLC vs PL from 18.66 +/- 2.46 to 19.50 +/- 2.77 (p less than 0.02). The WMS at 150 b/min improved significantly after PLC vs PL from 16.00 +/- 2.95 to 16.91 +/- 3.47 (p less than 0.01). The EF at rest was not significantly unchanged after PLC. The EF at 150 b/min was significantly different after PLC vs PL, from 53.6 +/- 7.36 to 55.6 +/- 6.45 (p less than 0.05). The blood pressure and the double product at rest and at 150 b/min were not unchanged after PLC.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

[New heterocyclic derivatives with germicidal activity. VI. Synthesis and activity of new 2-benzoxazoyl-2'-furanes and -thiophenes variously substituted in 5 and 5' positions].

Seventeen derivatives of 2'-furyl-2-benzoxazole and three derivatives of 2'-thienyl-2-benzoxazole, having different substituents in the benzene moiety (position 5) and in the furanic or thiophenic ring (position 5'), are described, with the aim of studying antibacterial and antimycotic structure-activity relationships. None of the compounds show an important antibacterial and/or antimycotic activity, when tested against nine bacteria and Candida albicans cultures; in any case it was much lower than that previously reported for the corresponding benzimidazoles. It seems that the = NH group of the imidazole ring, which is absent in the benzoxazole derivatives, might be important for the biological activity of this class of compounds.

Anti-Bacterial Agents↗
PubMed1988

Age-related changes of noradrenergic innervation of rat splanchnic blood vessels: a histofluorescence and neurochemical study.

The influence of ageing on the noradrenergic innervation of superior mesenteric artery and vein, renal artery and vein, and portal vein was studied in male Wistar rats by means of catecholamine histofluorescence, image analysis techniques and high pressure chromatography with electrochemical detection. Old age was accompanied by a marked increase in the density of noradrenergic innervation and an increase of noradrenaline levels in superior mesenteric artery, renal artery, and portal vein. In contrast, no significant age-related changes were observed in the density of noradrenergic innervation or in noradrenaline levels in superior mesenteric and renal vein. The present data indicate that, at least in superior mesenteric and renal artery and portal vein, senescence is not accompanied by loss or by lack of change in the noradrenergic innervation as commonly believed to be the case in many vascular trees. On the basis of our findings it cannot be excluded that increased plasma catecholamine levels observed in senescence derive, in part, from perivascular sympathetic endings.

Adrenergic Fibers↗