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L Cuzzolin

Publications and source records attributed to L Cuzzolin.

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

Effect of single and repeated doses of a new nitroderivative of acetylsalicylic acid on platelet TXA2 production in rats.

The effects of a new ASA-nitroderivative compound, NCX 4016 (ASA-NO2), on platelet TXA2 synthesis after single and repeated doses in the rat were investigated. Compared to ASA, cumulative doses of ASA-NO2 showed similar inhibitory effects on platelet TXA2 synthesis and significant increases in nitrite/nitrate plasma concentrations 1 h after the last drug administration: 24 h later nitrite/nitrate plasma levels returned to the control values, while serum TXA2 concentrations did not change. A time-course study after a single dose of ASA-NO2 showed a significant inhibition of platelet TXA2 production also 24 h after drug administration and a significant increase in nitrite/nitrate plasma levels until 10 h.

Animals↗
PubMed1995

Antiaggregating and vasodilatory effects of a new nitroderivative of acetylsalicylic acid.

We studied in vitro the effects on platelet aggregation and vascular tone of a new nitrocompound (nitroxy-butyl-acetylsalicylate: NO-ASA). In order to elucidate any possible activity due to the release of nitric oxide or the inhibition of platelet cyclo-oxygenase we compared NO-ASA to acetylsalicylic acid. NO-ASA 1 mM inhibited arachidonic acid-induced platelet aggregation (basal 75.4 +/- 2.35%; NO-ASA 22 +/- 3.46%; M +/- SEM; P < 0.001; n = 6), but proved less active than acetylsalicylic acid (complete inhibition at 2 x 10(-5) M). NO-ASA also significantly reduced thrombin-induced (0.04-0.08 U/ml) platelet aggregation in acetylsalicylic acid-treated platelets (basal 70.5 +/- 1.7%; NO-ASA 35.4 +/- 2.2%; P < 0.001; n = 10; IC50 7 x 10(-5) M). Methylene blue reduced the effects of NO-ASA on thrombin-induced (NO-ASA 46.7 +/- 5.25%; NO-ASA+MB 59.1 +/- 4.3%; P < 0.01; n = 8), but not arachidonic acid-induced platelet aggregation. The inhibitory effects of NO-ASA on platelet aggregation were partially removed by oxyhaemoglobin. Platelet thromboxane A2 production (TXB2 concentration in the supernatant of the aggregate 35.38 +/- 7.81 ng/ml; n = 8), was totally abolished by acetylsalicylic acid (0.17 +/- 0.04 ng/ml; P < 0.001; n = 8) and reduced by NO-ASA (8.3 +/- 4.05 ng/ml; P < 0.01; n = 8). In vitro studies on isolated rat aortic rings showed NO-ASA 10(-3) M, but not ASA up to 10(-3) M, induce a dose dependent vasorelaxation (100% of epinephrine-induced contraction) both in intact and endothelium denuded arteries (IC50 5 x 10(-5) M). Addition of methylene blue reversed this relaxation. In conclusion these data demonstrate that NO-ASA acts through a double mechanism: a) by inhibiting cyclo-oxygenase and b) by releasing NO active on guanylyn cyclase both in platelets and in vascular smooth muscle cells.

Adult↗
PubMed1995

Plasma concentrations and pharmacokinetic parameters of nitrofenac using a simple and sensitive HPLC method.

An accurate and sensitive HPLC method has been developed for the determination of nitrofenac, a new, original diclofenac derivate showing a good tolerability and a wide anti-inflammatory profile, diclofenac, and its metabolites in plasma. This method has been applied to evaluate the pharmacokinetic parameters of the drugs, using a noncompartmental model, after the oral administration of 5 mg/kg nitrofenac to rats. Nitrofenac and the internal standard flufenamic acid were dissolved in acetonitrile, and diclofenac was dissolved in methanol. The drugs were eluted from a 5 microns LC-8 column with a mobile phase consisting of acetonitrile/water (50/50 v/v) adjusted to pH 3.3 with glacial acetic acid, at a flow rate of 2 mL/min with UV detection at 280 nm for diclofenac and 275 nm for nitrofenac. The detection limit for the drugs in plasma was 25 ng/mL. The peak concentration of nitrofenac was reached 7 h after drug administration, while with diclofenac we observed three peaks at 2, 5, and 10 h; the mean residence time and the elimination rate constant for nitrofenac were 6.18 +/- 0.09 h and 0.37 +/- 0.03 h-1 respectively, while those for diclofenac were 12.24 +/- 0.11 h and 0.11 +/- 0.04 h-1. Under our conditions, the metabolism of nitrofenac produced 23% diclofenac and other metabolites: the plasma concentrations and kinetic characteristics of diclofenac are enough to induce an anti-inflammatory activity, while the clinical importance of the other metabolites remains to be elucidated.

Animals↗
PubMed1995

Effect of acute exercise on some haematological parameters and neutrophil functions in active and inactive subjects.

In this work we studied the possible effects of acute exercise on some haematological parameters and on some functions of neutrophils in seven active and six inactive subjects. Physical exercise (10 min on a cycle ergometer at a heart rate of 150 beats.min-1) induced a significant increase in total leucocyte, lymphocyte and neutrophil concentrations in active subjects; serum iron and ferritin concentrations were lower in active compared to inactive subjects. Cellular adhesion, bactericidal activity and superoxide anion production did not change after exercise, while we also observed some differences between active and inactive subjects before exercise. In particular, the neutrophils from active subjects showed a significantly higher percentage of adhesion, higher bactericidal activity and lower superoxide anion production. In conclusion, the training induced changes in some neutrophil functions, while acute exercise influenced, overall, leucocyte concentrations.

Adult↗
PubMed1995

Anti-inflammatory potency and gastrointestinal toxicity of a new compound, nitronaproxen.

Naproxen and its derivative nitronaproxen at the doses of 5 and 10 mg kg-1 were compared for their acute anti-inflammatory efficacy in a carrageenan oedema model and gastrointestinal toxicity in rats. Moreover, the effects of the two drugs were evaluated in the adjuvant arthritis, after chronic doses of 4 and 8 mg kg-1 administered orally for 18 days. The oedema reduction was maintained much longer (until 5 h) with nitronaproxen; the inhibition of arthritis was 50% or more with both doses of the examined drugs. From the histological examination of the stomachs, an extensive mucosal vasocongestion and haemorrhagic lesions have been observed in some rats treated with naproxen. The percentages of animals with ulcers were 50, 100 and 10 with naproxen 6 and 18 mg kg-1 and nitronaproxen 54 mg kg-1 respectively. A better gastrointestinal tolerability has been observed in arthritic and oedemic rats treated with nitronaproxen compared to naproxen: this could be due to the presence of nitric oxide that acts in maintaining the tissue perfusion and integrity.

Animals↗
PubMed1995

Changes in several neutrophil functions in basketball players before, during and after the sports season.

Neutrophils play an important role in the immune system, forming the "first line of defence" against invading microorganisms and there are few data available concerning neutrophil functions in relation to exercise. We investigated in 7 basketball professional players possible changes before, during and after the sports season, in some haematological parameters and in several aspects of the phagocytic process of neutrophils, such as adhesion, superoxide anion release and bactericidal activity. Training and competitions produced a significant rise in the number of total leukocytes and differential counts, but the values returned to the pre-start levels 3 weeks after the end of the championship. The bactericidal activity and the superoxide anion released were significantly greater during the sports season, while the percentage of cellular adhesion significantly decreased during the championship; after the sports season the values returned to the control levels. As in the literature data concerning neutrophil functions in relation to exercise are non-convergent, it is important in our opinion, to understand whether the alterations induced by exercise can persist after repeated stimuli.

Adult↗
PubMed1995

Inhibition by sodium nitroprusside of the expression of inducible nitric oxide synthase in rat neutrophils.

A well-known nitric oxide (NO)-releasing compound, sodium nitroprusside (SNP), decreases in a dose-dependent manner NO synthase (NOS) activity induced in rat neutrophils by treatment with lipopolysaccharide (LPS). This inhibitory action of SNP seems not to be due to its direct effect on the enzyme activity. The strong nitrosonium ion (NO+) character of SNP could be responsible for its inhibition of NOS induction in neutrophils.

Amino Acid Oxidoreductases↗
PubMed1995

Effect of a new non-steroidal anti-inflammatory drug, nitroflurbiprofen, on the expression of inducible nitric oxide synthase in rat neutrophils.

The effects of a non-steroidal anti-inflammatory drug, flurbiprofen, and its nitro-derivative, nitroflurbiprofen, on inducible nitric oxide synthase in rat neutrophils were examined. Nitroflurbiprofen was shown to inhibit nitric oxide synthase induction caused by lipopolysaccharide administration, while flurbiprofen had no effect on nitric oxide synthase induction. This inhibitory action may be ascribed to nitric oxide released from nitroflurbiprofen.

Administration, Oral↗
PubMed1995

Protective effect of NO on gastric lesions and inhibition of expression of gastric inducible NOS by flurbiprofen and its nitro-derivative, nitroflurbiprofen.

Nitroflurbiprofen (NFP) causes significantly less gastric lesions than flurbiprofen (FP), probably because of its capacity to release nitric oxide (NO) in the stomach. Lipopolysaccharide (LPS), which induces the expression of an inducible type of NO synthase (iNOS) in rat stomach, also reduces gastric mucosal damage elicited by FP. Furthermore, both FP and NFP decrease significantly the amount of mRNA encoding iNOS induced by LPS in the stomach. The inhibitory effect of NFP seems to be due at least in part to its ability to release NO.

Animals↗
PubMed1993

Acute anti-inflammatory activity and gastrointestinal tolerability of diclofenac and nitrofenac.

Diclofenac and its derivative nitrofenac were compared to test their anti-inflammatory efficacy and gastrointestinal toxicity in rats. A similar good anti-inflammatory activity of the two drugs was observed in carrageenan oedema and a marked gastrointestinal toxicity was induced by diclofenac, while nitrofenac failed to produce gastric damage even with very high doses (50 and 100 mg/kg). The lack of the gastric ulcers in rats treated with nitrofenac could be due to the absorption of the drug as an inactive inhibitor of PG synthesis and/or to the fact that probably nitric oxide is released in the intestine and plays an important protective role in maintaining the tissue integrity.

Animals↗
PubMed1992

Influence of radiotherapy on intestinal microflora in cancer patients.

We investigated in 15 patients with carcinoma of the uterine cervix or endometrium, who were undergoing postoperative radiation therapy, the effects of different fractionated radiation exposures on counts of fecal bacteria, on the growth of Clostridium difficile and Clostridium perfringens enterotoxin production. We observed a generally significant decrease in intestinal microflora after the first radiation exposure, whereas at the end of radiotherapy all bacteria increased and reached basal values except Enterococcus faecium 1, lactobacilli and total anaerobes. In some patients we observed an overgrowth of some Clostridium spp. which were potential pathogens associated with clinical symptoms. We did not observe an influence of multiple radiations on C. perfringens enterotoxin fecal contents. We conclude that patients receiving radiotherapy may benefit from the intake of oral bacteriotherapy, i.e. live beneficial bacteria such as Bacillus subtilis at the beginning of the irradiation exposure.

Aged↗
PubMed1992

Hepatic and intestinal effects of flurithromycin and erythromycin in the rat.

The effects of flurithromycin (30-100 mg/kg p.o.), a fluorinated macrolide, on rat hepatic enzymes and intestinal microflora have been compared with those of equal doses of erythromycin. This latter drug significantly decreases cytochrome b5, cytochrome P-450 and aminopyrine N-demethylase and moderately influences intestinal microbial flora. Flurithromycin showed almost opposite characteristics, with no hepatic interaction and marked effects on some bacterial species (e.g. Bacteroides) known to facilitate the colonization of pathogenetic bacteria.

Animals↗
PubMed1992

[In vivo and in vitro experimentation with the effects of chlorhexidine in patients who have undergone a periodontal intervention].

The periodontal pack is often used to cover the surgical site after surgery, even when associated with local applications of preparations containing chlorexidine, in order to obtain an antiseptic protection. However many people question whether the drug effectively succeeds in penetrating the pack, or if the presence of the pack itself doesn't obstruct the action of the medication. The aim of this work is to evaluate the efficiency of the clorexidine in the surgical area with and without a periodontal pack. In a first stage, a case was chosen and contemporary operated on in two different but anatomically similar sites at the same time. One of the two sites was covered with a chlorexidine gel for the following week, whilst the other was left without medication. After seven days the stitches removed from the two different sites were placed in culture mediums to number and classify the bacterial strains present. In the second stage of the experiment, another eight patients were operated on in the same way, and the two sites covered with periodontal packs. In one of the two sites a layer of chlorexidine gel was positioned under the pack, and the chlorexidine above and on the sides of the pack was continually renewed throughout the week following the operation. The other site was not treated. The results obtained show that the pack partially reduces the action of the drug medication, probably because an insufficient amount reaches the site. The activity and efficiency of chlorexidine against the strains of bacteria found in vivo were tested in vitro. The chlorexidine destroyed all of them.(ABSTRACT TRUNCATED AT 250 WORDS)

Bacteria↗
PubMed1992

Desferrioxamine potentiated SOD antiinflammatory activity in rat adjuvant arthritis: role of iron and bacterial toxins.

In this paper we studied the modulating inflammatory activity of iron in the adjuvant arthritis, taking indomethacin as a standard antiinflammatory drug and a superoxide dismutase derivative (MPEG-SOD) as a scavenger of free radicals. Moreover, we evaluated the changes in potential intestinal pathogens requiring iron for growth, in order to study the role of bacteria in the altered gastrointestinal functions observed during arthritis. We observed a 50% arthritis inhibition on the 14th day with MPEG-SOD plus desferrioxamine, a significant decrease in serum iron in arthritic rats compared to controls, and a significant Cl. perfringens increase on the 28th day in the presence of MPEG-SOD. Our data demonstrate that hypoferremia, in arthritis, is a protective mechanism overall in the early phase and could protect the intestinal tract by inhibiting the development of potential pathogens.

Animals↗
PubMed1991

Pharmacokinetics and renal tolerance of aztreonam in premature infants.

Aztreonam (30 mg/kg of body weight) was administered intravenously over 3 min every 12 h to 30 preterm neonates divided into two groups according to gestational age (mean age for group A was less than 30 weeks and mean age for group B was greater than 30 weeks) and birth weight (mean weight for group A was less than 1,500 g and mean weight for group B was greater than 1,500 g). Blood and urine samples were analyzed by microbiological assay. The pharmacokinetics were described by one-compartment and noncompartment models. The mean half-life and clearance for premature infants weighing less than 1,500 g were 5.33 +/- 3.61 h and 1.52 +/- 1.33 ml/min/kg, respectively; for those weighing more than 1,500 g, the values were 4.08 +/- 2.28 h and 2.41 +/- 2.10 ml/min/kg, respectively. The mean urinary concentration of aztreonam in 15 premature infants during the first 6 h of therapy was 242.72 +/- 188.19 micrograms/ml, with a mean percentage of elimination of 13.29%. Urinary excretion of N-acetyl-beta-D-glucosaminidase (a specific and sensitive test for the detection of drug-induced renal tubule damage) did not show significant differences in our group of premature infants compared with that in a control group. The dose of 30 mg/kg and a dosage interval of 8 to 12 h could be recommended for the treatment of suitable bacterial infections in all premature infants.

Acetylglucosaminidase↗
PubMed1990

Indomethacin induced hepatic alterations in mono-oxygenase system and faecal Clostridium perfringens enterotoxin in the rat.

The administration of indomethacin to rats, at the dose of 10 mg/kg once daily for three days, caused a loss of microsomal cytochrome P-450 and cytochrome b5 in the liver, and a fall in drug-metabolizing enzyme activities (i.e. aminopyrine N-demethylase, NADP cyt. c. reductase). Indomethacin also induced intestinal lesions and a significant increase in Clostridium perfringens enterotoxin levels in the feces at 24 hours after both the second and third day of treatment. The above findings suggest that the development of intestinal lesion and the accompanying release of Clostridium perfringens enterotoxin, as well as hepatic enzyme alterations in the rat, result from indomethacin administration. Some of the data in this paper were presented at the Meeting of British Pharmacological Society in Ireland, July 6th-8th, 1988.

Aminopyrine N-Demethylase↗