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G Zavattini

Publications and source records attributed to G Zavattini.

At least 19 recordsLinked to original sources
PubMed2006

Experimental observation of optical rotation generated in vacuum by a magnetic field.

We report the experimental observation of a light polarization rotation in vacuum in the presence of a transverse magnetic field. Assuming that data distribution is Gaussian, the average measured rotation is (3.9 +/- 0.5) x 10(-12) rad/pass, at 5 T with 44 000 passes through a 1 m long magnet, with lambda = 1064 nm. The relevance of this result in terms of the existence of a light, neutral, spin-zero particle is discussed.

Journal Article↗
PubMed1990

[Tiaprofenic acid: levels in plasma and upper airway tissues].

Inflammatory processes of the upper airways can be successfully improved by using non steroid anti-inflammatory drugs, alone or in association with antibiotics. Recent clinical reports suggest that tiaprofenic acid (TA) is particularly suited for this purpose. This fact can be explained on the basis of the drug's pharmacokinetics and by the high concentration TA can achieve in the respiratory tract mucous membranes. In order to confirm this hypothesis TA levels were studied in the plasma as well as in tonsillar and turbinal tissue. Patients admitted for tonsillectomy or turbinectomy were given two tablets (600 mg) of TA from one and a half to five hours before surgery. In all cases blood and tissue samples were taken at the same time during surgery and drug levels determined by HPLC. Plasma levels ranged from 12 to 26 to 32.2 microgram/ml; tissue levels ranged from 3.9 to 5.4 to 4.9 micrograms/g, respectively, depending on time of administration. There was no significant difference between tonsillar and turbinal tissue. These results suggest a good penetration of nasal and airway mucosa by TA and are in agreement with the clinical data on the efficacy of TA in dealing with upper airway inflammatory conditions.

Adolescent↗
PubMed1989

Ambroxol inhibits airway hyperresponsiveness induced by ozone in dogs.

To follow up previous observations that airway hyperresponsiveness induced by ozone is linked to airway inflammation and particularly to the release of arachidonic acid metabolites, we investigated the effect of ambroxol (a mucoactive and surfactant-stimulating drug that has recently been discovered to inhibit the release of arachidonic acid from cell membrane phospholipids) on airway hyperresponsiveness and bronchoalveolar neutrophilia induced by ozone in dogs. One group of 5 dogs was studied before treatment with nebulized saline and then after exposure to ozone (3 ppm, 1 h); another group of 6 dogs was studied before treatment with ambroxol (100 breaths of a 1% solution) and after exposure to ozone. On each occasion, we measured airway responsiveness to acetylcholine and counted the number of cells in bronchoalveolar lavage fluid. When the dogs were given the saline placebo, ozone induced a marked increase in airway responsiveness to acetylcholine and a marked influx of neutrophils in the airways. When the dogs were given ambroxol, ozone induced the same increase in the number of neutrophils in bronchoalveolar lavage, but did not increase the degree of airway responsiveness to acetylcholine. We conclude that ambroxol inhibits ozone-induced airway hyperresponsiveness in dogs, probably by inhibiting the formation and release of oxygenation products of arachidonic acid from neutrophils.

Acetylcholine↗
PubMed1987

Ambroxol for the prevention of chronic bronchitis exacerbations: long-term multicenter trial. Protective effect of ambroxol against winter semester exacerbations: a double-blind study versus placebo.

In a 6-month, double-blind multicenter trial conducted over the winter, the effects of daily administration of ambroxol retard (75 mg) were compared with those of placebo in preventing exacerbations and improving symptoms and clinical signs in chronic bronchitis patients. The trial was completed by 110 patients in the ambroxol group and by 104 in the placebo group. Initially, there were no significant differences between the groups. By the end of the 2nd month of treatment, 67.2% of the ambroxol group had had no exacerbations compared to 50.4% in the placebo group. At the end of the 6-month trial, 45.5% of the treatment group had had no exacerbations, compared to only 14.4% of the control group. These differences were statistically significant. Patients in the treatment group lost significantly fewer days through illness (442) and had fewer days when they needed antibiotic therapy (371) compared to the placebo group patients (837 and 781). Ambroxol also produced statistically significant symptomatic improvement, measured as difficulty in expectoration, coughing, presence of dyspnea and the auscultatory signs as compared to controls. Since ambroxol was well tolerated and compliance was good, it appears like a drug of choice for pharmacological prophylaxis of chronic bronchitis.

Adult↗
PubMed1987

Multicenter study on the treatment of secretory otitis media with ambroxol. Importance of a surface-tension-lowering substance.

Animal studies showed the presence of a surfactant substance in the Eustachian tube. On the premise that alteration of surfactant-like substance might cause pathology of the middle ear in man, a multicenter (24 ENT hospitals) double-blind trial versus placebo was carried out in 435 adults and children with secretory otitis media. Treatment was ambroxol, a drug that changes the bronchial secretions and promotes surfactant synthesis. The dosage regimen was as follows: adults--one 30-mg tablet of ambroxol 3 times/day; children--9 mg of ambroxol syrup, 4 times daily. The treatment lasted 15 days. The clinical signs and symptoms (hypoacusis, conduction deafness) and the otoscopic and rhinoscopic findings of treated patients improved. The differences in these parameters between patients given ambroxol and the controls were statistically significant (p less than 0.05). The symptomatological amelioration was supported by improvement in tympanometric findings and hearing threshold. Drug tolerance was excellent.

Adult↗
PubMed1987

An alternative to steroids for prevention of respiratory distress syndrome (RDS): multicenter controlled study to compare ambroxol and betamethasone.

The results are reported of a multicenter randomized study of the effectiveness of maternal administration of betamethasone versus ambroxol, a substance of the group of the benzylamines, for prevention of RDS in preterm infants. Women of 27 to 34 weeks gestation with threatened premature delivery or planned premature delivery were admitted to the trial. Between September 1981 and November 1984 a total of 288 randomized patients delivered 315 neonates. The incidence of RDS was assessed in 169 viable neonates born before the 37th week. Of these 86 were born of 76 mothers treated with beta-methasone and 83 of 76 mothers treated with ambroxol. The overall incidence of RDS was significantly (P less than 0.05) higher in the betamethasone group (31%) than the ambroxol group (13%). Ambroxol was significantly more effective than betamethasone in twin births, in infants born before the 31st week, when ROM to delivery time was more than 48 hours, when treatment to delivery time was between 2 and 7 days and in female infants. The neonatal infection rate was significantly higher (P less than 0.05) in the group of betamethasone treated infants (18% with four fatalities) than in the group of ambroxol treated infants (9% with one fatality). These results suggest that ambroxol may be a valid alternative to steroids for prevention of RDS.

Ambroxol↗
PubMed1986

A study of cellular immunity in newborns after prevention of respiratory distress syndrome (RDS).

Cellular immune responsiveness against infections was evaluated in four groups of newborns. The first group was composed of preterm newborns whose mothers had received betamethasone for prevention of RDS, the second group of preterm newborns whose mothers had received ambroxol for prevention of RDS, the third group of preterm newborns whose mothers had not received any drug enhancing surfactant production, and the fourth group were healthy-term infants. A reduction of OKT4+ cells and functional deficits of neutrophils were found in preterm infants born to mothers treated with steroids, whereas no functional abnormalities of immune-competent cells were observed in preterm infants born to mothers treated with ambroxol.

Ambroxol↗
PubMed1986

Possibility of interaction among antibiotics and mucolytics in children.

A controlled clinical trial in children with acute infections of the lower respiratory tract was carried out to see whether or not treatment with ambroxol could bring about faster and better results. One hundred twenty children with acute lower respiratory tract infections were all given antibiotics plus, at random, either ambroxol (1.5-2.0 mg/kg body weight orally) or a placebo. The duration of the trial was ten days. All the patients in both groups were cured clinically. However, remission of the cough, of the chest pathological signs, as well as the improvement of the lung radiographical pictures were significantly more rapid in children treated with ambroxol than in those who received the antibiotic alone. Ambroxol was tolerated perfectly by all the children.

Ambroxol↗
PubMed1985

Correlation between newborn gastric aspirate microviscosity and gestational age.

Fluorescence polarization (FP) values were determined in 59 samples of amniotic fluid and in 56 samples of newborn gastric aspirate, collected from the 28th to 41st week of gestation. Both amniotic fluid and gastric aspirate FP values showed a significant correlation respectively with gestational age (r = 0.77; p less than 0.01 and r = 0.50; p less than 0.01). The two regression lines were parallel (F = 0.052; p = 0.8046). Mean FP of gastric aspirate were about 0.05 lower than those of amniotic fluid. One infant whose gastric aspirate FP value was 0.342 developed RDS.

Amniotic Fluid↗
PubMed1985

Effect of ambroxol on human phagocytic cell function.

The in vitro effects of ambroxol on phagocytic and microbicidal activities of human neutrophils and monocytes have been studied. Preincubation of neutrophils with ambroxol (10 to 100 ng/ml) had no effect on their phagocytic or microbicidal capacities. On the other hand, when monocytes were preincubated for 24 hours with ambroxol a significant increase of their microbicidal activity was observed, without effect on the phagocytic properties.

Ambroxol↗
PubMed1984

Polymorphonuclear leucocytes functions from premature infants after prevention of respiratory distress syndrome with betamethasone and ambroxol.

An increase in the infection rate both in mother and newborn after antenatal administration of corticosteroids for prevention of RDS has been shown. The aim of this study was to compare PMN functions in two groups of premature infants whose mothers had received betamethasone or ambroxol for prevention of RDS. Blood samples were collected within the first four days of life from 40 newborns. Thirteen infants received antenatal administration of 6 mg of betamethasone acetate and 6 mg sodium phosphate i.m., which was repeated 24 hours later. Twelve received antenatal administration of ambroxol, 1 g i.v. every day for 5 days. Fifteen did not receive any antenatal treatment. Mean gestational age and mean birth weight was not significantly different between the betamethasone group (33 +/- 3.1 weeks and 2080 +/- 567 g) and the ambroxol group (32.9 +/- 3.4 weeks and 2164 +/- 793 g). Phagocytosis and killing ability was significantly lower in the betamethasone group in comparison to the ambroxol group (21.3% +/- 2.2 rather than 48.4% +/- 15; p 0.01 and 11.4% +/- 1.7 rather than 20.5% +/- 6.1; p 0.01 respectively). Immunoglobulin or complement levels were not significantly different in the three groups.

Ambroxol↗
PubMed1984

Cord blood prolactin and thyroid hormone levels after antenatal administration of betamethasone or ambroxol for prevention of respiratory distress syndrome (RDS).

Several studies showed that ambroxol is efficacious in enhancing fetal lung maturation, provided large doses are given. We investigated cord blood levels of PRL and thyroid hormones in 31 infants born after antenatal administration of betamethasone, in 31 infants born to mothers treated with ambroxol for prevention of RDS and in 27 infants whose mothers had not received any drug enhancing fetal lung maturity. The only significant difference (p less than 0.05) between the groups was noted in T3 mean levels that were higher in the ambroxol group than in the betamethasone group between the 33th to 36th week of gestation. Hormone levels did not appear significantly different in infants who developed RDS rather than in infants who did not.

Ambroxol↗
PubMed1981

Metabolism of pinazepam by rat liver microsomes.

The pathways by which pinazepam and diazepam are metabolized by rat microsomes in vitro were studied in detail. Using a gas chromatographic technique to measure either the two parent compounds or their metabolites, it was demonstrated that pinazepam and diazepam were metabolized through the same pathways, but at different rates. Pinazepam was mainly N-dealkylated, while the C3-hydroxylation was a minor metabolic pathway. Diazepam was mostly C3-hydroxylated, with very little being N-demethylated. The different rats for the two metabolic pathways could be of importance in differentiating the action of the two drugs in vivo.

Animals↗
PubMed1978

Pharmacokinetic studies on ditazole, a novel inhibitor of platelet aggregation.

The distribution of ditazole in blood and tissues of rats was determined by a simple GLC technique. Ditazole, after intravenous injection in rats (20 mg/kg), entered preferentially into the brain, the liver, and the heart in decreasing order. In the epididymal adipose tissue, the drug was present only in small amounts. Ditazole disappeared from the rat organs 4 hr after the treatment. The apparent ditazole half-life in rat blood was 41 min, the volume of distribution was 2.068 liters/kg, and the body clearance was 0.0345 liter/kg/min.

Animals↗