PubMed Health⌕ Search

Biomedical subjects

C Bellucci

Publications and source records attributed to C Bellucci.

At least 37 records · Page 2Linked to original sources
PubMed1996

Collagen synthesis and cell growth in chick embryo fibroblasts: influence of colchicine, cytochalasin B and concanavalin A.

Culturing of chick embryo fibroblasts in the presence of colchicine or cytochalasin B with and without concanavalin A (Con A) demonstrated that colchicine induces greater neosynthesis of endocellular type I collagen, whereas cytochalasin B boosts secretion. The effects are modified by the addition of Con A, which increases alpha 2 more than a1 chain production. 3H-thymidine incorporation is unaffected by cytochalasin B, but stimulated by colchicine. Con A neutralizes the stimulatory action of colchicine. It would therefore seem that Con A exerts transmembrane control of effects induced by colchicine and cytochalasin B by binding to cell surface receptors and so triggering rearrangement of the cytoskeleton.

Actins↗
PubMed1996

Effects of interleukins on Crouzon fibroblast phenotype in vitro. Release of cytokines and IL-6 mRNA expression.

In Crouzon's syndrome, the cranial morphogenic processes are altered due to the early fusion of the facial and basal cranial bones. Evidence that Crouzon fibroblasts have an altered phenotype which is modulated by interleukin 1 (IL-1) and interleukin 6 (IL-6) is provided. [3H]Thymidine incorporation and cell count studies showed that Crouzon fibroblasts have an accelerated proliferation rate. [3H]Glucosamine incorporation studies, followed by chromatography analysis of culture medium samples, revealed that the various classes of glycosaminoglycans (GAG) secreted into the medium were differently distributed in Crouzon and normal fibroblasts. Crouzon fibroblasts secreted less total GAG, particularly hyaluronic acid (HA) and heparan sulfate (HS), but a relatively greater quantity of chondroitin sulfate. Type I and III collagen were raised in Crouzon fibroblast medium whereas the concentration of fibronectin was lower than in normal cells. Interleukin treatment induced changes in cell growth and neosynthesis of extracellular matrix macromolecules. Both IL-1 and IL-6 stimulated proliferation of Crouzon fibroblasts, whereas only IL-6 increased [3H]thymidine incorporation in normal cells. IL-1 provided a drop in HA and a rise in GAG sulfates in normal fibroblasts, but caused an opposite effect in Crouzon fibroblasts. Type I collagen and fibronectin secretions are differently modulated by the cytokines in the two populations. Moreover, level of IL-1 able to stimulate [3H] thymidine incorporation into mouse thymocytes, and level of IL-1 receptor antagonist (IL-1ra), as determined by ELISA, were higher in pathological than in normal fibroblasts. Also evidence that levels of IL-1 alpha and IL-6 proteins measured by ELISA and also IL-6 mRNA expression are enhanced in Crouzon fibroblasts is provided. These novel data suggested that, in Crouzon's syndrome, the modifications in the relative concentrations of the extracellular matrix (ECM) components associated with the abnormal cytokine networks may alter the balance of the microenvironment where the morphogenic events take place.

Adolescent↗
PubMed1996

Synthesis, characterization and pharmacological profile of tropicamide enantiomers.

The synthesis, chemical characterization and antimuscarinic activity of the two enantiomers of tropicamide are reported. Functional (rabbit vas deferens, guinea pig heart (force) and ileum) as well as binding experiments (m1 and m4 human muscarinic receptors expressed in CHO-K1 cells: M2 and M3 receptors of rat heart and submaxillary gland membranes) were used to evaluate the antimuscarinic activity of the enantiomers. The results show that none of the enantiomers is able to significantly discriminate among the receptors studied and therefore do not support the proposal of tropicamide as an M4 (m4) selective agent.

Analgesics↗
PubMed1995

Analgesic, antimuscarinic activity and enantioselectivity of the four isomers of 3-quinuclidinyl tropate as compared with the enantiomers of hyoscyamine.

The four stereoisomers of 3-quinuclidinyl tropate (2) were synthesized and their absolute configuration established. The analgesic activity of the four isomers on the hot-plate test and their muscarinic antagonism on rabbit vas deferens (M1), guinea-pig heart (Force, M2) and ileum (M3) and on the muscarinic receptors present in immature guinea-pig uterus were evaluated. The results were compared with those of the enantiomers of hyoscyamine (1). No apparent correlation was found between the analgesic activity and antimuscarinic activity on M1, M2 and M3 receptors, whereas striking differences exist between the affinity values of the analgesic enantiomer of hyoscyamine (R-(+)-1) and those of the inactive isomers of 2 on the muscarinic receptor present in immature guinea pig uterus. Molecular Modelling studies have shown that the only difference between 1 and 2 lies in the volumes occupied by the basic part of the molecules.

Analgesics↗
PubMed1995

Phenotype of in vitro human otosclerotic cells and its modulation by TGF beta.

A study was carried out to obtain a more detailed picture of the phenotypes of human otosclerotic and normal bone cells and to analyse the response of both populations to treatment with TGF beta 1. Total collagen synthesis was found to be decreased, but fibronectin secretion increased in otosclerotic with respect to normal cells. Although overall glycosaminoglycan (GAG) synthesis was lower in otosclerotic cells, the sulphated GAG to hyaluronic acid (HA) ratio was higher, in particular there was greater expression of chondroitin (CS) and dermatan sulphates (DS). TGF beta 1 induced a more marked increase in collagen and fibronectin release and greater production of sulphated GAGs as DS and heparan sulphate (HS) in the otosclerotic cells. The fact that the phenotype of the otosclerotic cells differed from that of the normal cells and could be modified by TGF beta 1 treatment, suggests that TGF beta 1 is implicated in the pathogenesis of otosclerosis.

Bone and Bones↗
PubMed1994

Chondroitin sulphates and embryonic chick skin fibroblast proliferation.

We have investigated the action of sulphated glycosaminoglycans (GAGs) upon primary 11-day chick embryo skin fibroblasts cultured for various periods of time in the presence or absence of fetal calf serum (FCS). Chondroitin 4- and 6-sulphate (CS) added to serum supplemented medium provoked a decrease in DNA synthesis both in sparse and crowded cultures only at high concentrations (250 micrograms/ml). Synthesis of endocellular and secreted proteins was not affected. In contrast, CS administered to fibroblasts for 24 h in serum-free medium stimulated DNA synthesis. We postulate that the CS stimulating effect seen in serum-free cultures might be antagonized by peptide regulators of cell growth normally present in serum.

Animals↗
PubMed1994

Interleukin-1 and interleukin-6 differentially regulate the accumulation of newly synthesized extracellular matrix components and the cytokine release by developing chick embryo skin fibroblasts.

In the present study, we demonstrate that both interleukin-1 (IL-1) and interleukin-6 (IL-6) induced a significant decrease in glycosaminoglycan (GAG) synthesis and, more strikingly, secretion by 7 and 13 day-old chick embryo skin fibroblasts. We demonstrated that interleukin treatment also inhibited the synthesis of collagenase-digestible proteins (type I collagen). In addition, tissue culture supernatants (conditioned media, CM) were tested for reactivity for IL specific ELISAs and for their ability to stimulate proliferative responses in mouse thymocytes and hybridoma cells. Our findings demonstrate that chick embryo skin fibroblasts spontaneously produce IL-1 and, in even greater amounts, IL-6. Highest levels of interleukin secretion were found in the CM of 13 day-old fibroblasts and the IL-1 beta isoform was predominant over IL-1 alpha. Pretreatment of the fibroblasts with either IL-1 or IL-6 increased the secretion of both cytokines. Increased IL-1 levels were correlated with enhanced IL-1 bioactivity in the CM of IL-6 treated fibroblasts. By contrast, the raised concentrations of IL-1 in the CM of IL-1 treated cells and IL-6 in the CM of IL-1 or IL-6 treated fibroblasts failed to translate into augmented bioactivity. These observations, taken together, indicated that IL-1 and IL-6 are able to regulate the synthesis and secretion of ECM macromolecules of developing connective tissues and the cytokine release by chick embryo skin fibroblasts.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

23Na NMR evaluation of human erythrocytes Na+/K+/CL-cotransport. A study in elderly hypertensives.

The behaviour of sodium transport systems across the cell membrane has been poorly investigated in elderly hypertension. Sodium efflux driven by Na+/K+/Cl-cotransport activity was therefore investigated (using a novel NMR-spectroscopy method) in 5 elderly hypertensive males (mean age 78 +/- 5 years) and 5 normotensive controls (mean age 79 +/- 3 years). In order to exclude any change in cotransport activity secondary to metabolic abnormalities, both patients and controls were non-obese and had normal glucose and lipid metabolisms. The Na+/K+/Cl-cotransport evaluation was performed after three months of pharmacological wash-out, under a diet containing 120 mEq of Na+/day. The resulting data showed that Na+ efflux due to outward Na+/K+/Cl-cotransport was higher in hypertensive group than in the normotensive one (0.50 +/- 0.10 mmol Na+/l cells/hr. vs 0.33 +/- 0.03 mmol Na+/l cells/hr., respectively, p < 0.05). Intracellular Na+ content was similar in both groups. At variance with previous data from the literature, our findings indicate that the Na+/K+/Cl-cotransport activity is elevated in elderly hypertensives.

Aged↗
PubMed1989

Negative inotropic and calcium antagonistic activity of alkyl and arylalkyl phosphonates.

Several alkyl and arylalkyl diethylphosphonates related to fostedil have been synthetized and tested for negative inotropic activity (isolated guinea pig left atrium) and Ca++ antagonistic activity (isolated guinea pig aortic strips). The results show that negative inotropic and Ca++ antagonistic activity might depend from different molecular features.

Animals↗
PubMed1985

SAR studies in the field of calcium(II) antagonists. Effect of modifications at the tetrasubstituted carbon of verapamil-like compounds.

A number of fluorenyl and diphenylmethane analogues of verapamil, chosen as having the same substituents arranged in different ways around the quaternary carbon, were synthesized in order to evaluate the importance of the stereoisomerism at that point of the molecule. The compounds were tested with the Langendorff technique and coronary perfusion pressure (CPP), left ventricular pressure (LVP), and heart rate (HR) were recorded. While most of the compounds were almost inactive on these parameters, three of them did show interesting cardiovascular action. In particular they produced a more pronounced decrease in CPP than verapamil, with a less marked negative inotropic effect. Structure-activity relationships and the mechanism of action of the compounds are discussed.

Animals↗
PubMed1985

Echinococcus granulosus: diagnosis of hydatid disease in man.

Several antigen fractions were prepared from sheep hydatid fluid and scolices of Echinococcus granulosus by salting out with ammonium sulphate. Sera from subjects with hydatid disease and from uninfected controls were assayed by the IHA, Latex, ELISA and Complement Fixation tests. The greatest sensitivity was given by the hydatid fluid 0.8 M fraction in the IHA test. This antigen also gave good results with the ELISA technique. Antigens from sheep fertile fluid were diagnostically superior to those from scolices. The specificity was excellent for all antigens examined.

Antibodies↗
PubMed1985

Search for new Ca++ antagonists. Lipophilic oximes and phosphonates.

On the basis of the reported slow channel-inhibiting activity of oximes and phosphonates a series of compounds bearing such functions on lipophilic carriers were synthesized and studied. Among the compounds studied only (VI b) shows a slight cardiovascular activity. The surprising lack of activity of diethyl 3,4-dimethoxybenzyl-phosphonate (XIV), which is closely related to Fostedil, is discussed.

Animals↗
PubMedDate not supplied

[Adverse effects of wrong brushing technic].

In the present study brushing lesions have been considered clinically. Toothbrushing type, frequency, and lasting of brushing seem to be not involved in the formation of such lesions, directly connected with brushing technique and pressure.

Adult↗