Biomedical subjects

C Dragonetti

Publications and source records attributed to C Dragonetti.

7 recordsLinked to original sources

PubMed1992

Evaluation of antihistamine-related daytime sleepiness. A double-blind, placebo-controlled study with terfenadine.

The daytime sleepiness potentially associated with antihistamines was evaluated by the multiple sleep latency test (MSLT) in a study comparing terfenadine with placebo. According to a double-blind, randomized, cross-over design, 12 healthy men were given either 120 mg terfenadine or placebo once daily in the morning, for 3 consecutive days with a 5-day interval. EEG-polygraphic recordings were made each study day at 9:30 and 11:30 a.m., and 1:30, 3:30, and 5:30 p.m., and the tendency to fall asleep was measured. All mean stage-1 sleep latencies throughout the study failed to show any significant difference between terfenadine and placebo. Accordingly, psychomotor performance assessed by visual and auditory reaction time did not change after treatment. The results of this study confirmed that terfenadine does not induce daytime sleepiness as objectively measured by MSLT.

Adult↗

PubMed1992

[Mid-term clinical study of the effectiveness of and tolerability to simvastatin ++ in dyslipidemic patients].

The HGM-CoA reductase inhibitors, blaking up intracellular synthesis of cholesterol, support the receptorial captation of cholesterol with a reduction in plasma levels. The simvastatin efficacy was evaluated in 12 patients, mean age 59 +/- 10 years with a primary hypercholesterolemia. All the patients were on a pharmacologic wash out for at least 6 weeks and dietetic treatment (according to their weight and daily needs) for a week. Total cholesterol, HDL-cholesterol and triglycerides plasma levels were taken at time 0. Then a treatment with simvastatin 10 mg/die was begin for 4 weeks and than increased to 20 mg in patients with plasma cholesterol > 200 mg/100 ml at the end of fourth week. In some patients the dose was increased up to 40 mg for the elevated levels of plasma cholesterol at the end of the second month. All the parameters above were controlled monthly for three months. A control was performed at the end of sixth month of treatment. After 4 weeks treatment, simvastatin induced reduction in cholesterol plasma levels (p < 0.005), that continued during the whole time treatment (228 mg/dl at 24 week, p < 0.005 vs basal). The mean dosage of the simvastatin at fourth month was of 25 mg/die. During the treatment an increase of HDL plasma levels was noted, but this increment wasn't statistical significant (40 +/- 7 vs 45 +/- 9 mg/100 ml). No significant impairment of principal metabolic and laboratory parameters were observed during the treatment. These data indicate that simvastatin in small dose induce a reduction in cholesterol plasma levels with a significant increase in HDL without side effects.

Adult↗

PubMed1991

Early graft injuries after pancreatic transplantation in syngeneic rats. Cytoprotective effects of gabexate-mesilate.

Failures in experimental and human pancreatic transplantation are mainly attributable to rejection, graft thrombosis, and technical problems. There are, however, problems related to other causes, such as preservation injuries, which we found to exhibit, at least within the first 6 h, the same histological patterns seen in experimental acute pancreatitis. We performed pancreatic transplantation in 110 syngeneic rats under different preservation techniques and administration of gabexate mesilate, a synthetic protease inhibitor. The results showed that antiprotease treatment reduces graft preservation injuries significantly.

Analysis of Variance↗

PubMed1979

Heparan sulfate at the surface of HeLa cells.

HeLa cells, labeled with Na235SO4, release into the culture medium 35SO4 bound to plasma membrane vesicles next to 35SO4-glycoproteins and free 35SO4. Plasma membrane vesicles, experimentally produced by treatment with formaldehyde, contain 35SO4 and their surface can be stained with high iron diamine. Scanning of chromatograms of the trypsinate from labeled cells demonstrates radioactivity on the spot of heparan sulfate. It is concluded that HeLa cells synthesize heparan sulfate, which is incorporated at the plasma membrane and released by shedding of small vesicles.

Cell Membrane↗

PubMed1977

Colloidal iron binding to the surface of HeLa cells, spreading in monolayer culture.

We have used the colloidal iron (CI) binding technique, adapted for transmission electron microscopy, for semiquantitative evaluation of the negative charge density at the surface of HeLa cells in monolayer culture. The surface area increases when HeLa cells spread on the substrate. This increase brings about a decrease in the thickness of the CI rim, indicating a decrease in negative surface charge density. This phenomenon implicates lowering of the electrostatic repulsion, and explains the formation of intercellular contacts at the level of spread parts of the cell. Because of lack of penetration, CI particles are absent in regions of cose apposition between cells and between cells and substrates. Absence of CI binding in broader intercellular or cell-substrate spaces was explained through masking of the anionic groups.

Cell Membrane↗

PubMed1976

Histochemical evidence for sulfomucins at the surface of Hela cells.

The nature of the negatively charged groups present at the surface of HeLa cells was further investigated. Therefore we applied a series of light microscopic staining techniques, widely used for the demonstration of epithelial mucosubstances on tissue sections, to HeLa cells from suspension cultures. Our histochemical findings confirmed the presence of carboxylated substances at the surface of these cells. Furthermore we obtained conclusive evidence for the presence of sulfated molecules. Both substances seem to be closely related to epithelial sialomucins and sulfomucins.

Alcian Blue↗

PubMed1976

Cytochemistry of colloidal iron binding to the surface of Hela cells and human erythrocytes.

It seems from the literature that colloidal iron (C.I.) binding sites on cell surfaces cannot be completely removed by treatment with Vibrio Colerae alpha-neuraminidase. We wondered if C.I. particles bind to negative groups other than the carboxyl groups of sialic acids. Using HeLa cells from suspension cultures and fresh human erythrocytes, we examined, with the transmission electronmicroscope, the influence of the following enzymatic and histochemical treatments on C.I. staining: alpha-neuraminidase; hyaluronidase; ribonuclease; alpha-amylase; mild methylation (MM); MM + saponification (Sap.); MM + Sap +MM; MM + Sap + alpha-neuraminidase; active methylation (AM); AM + Sap; AM + Sap + AM; AM + Sap + alpha-neuraminiadase; CH3OH (80%); Sap. It seemed from these experiments that the carboxyl groups of alpha-neuraminidase sensitive sialic acids constitute the majority of binding sites for C.I. to these particular cells. The most interesting candidates for the residual binding of C.I. are carboxyl groups of alpha-neuraminidase resistant molecules, sulfon, sulfin, and sulfate groups.

Binding Sites↗