Search PubMed⌕ Search

Biomedical subjects

L A Pini

Publications and source records attributed to L A Pini.

At least 37 records · Page 2Linked to original sources
PubMed1995

Effects of acetylsalicylic acid on serotonin brain receptor subtypes.

1. The lysine salt of acetyl salicylic acid (ASA) at a dose equivalent to 400 mg/kg of acetyl salicylic acid (ASA) was intraperitoneally administered in rats. 2. After 30 and 120 min ASA did not modify the number of receptors nor the affinity of [3H] 8-OH-DPAT binding sites in pons and cerebral cortex. On the other hand, the receptor number in the cortex membranes decreased significantly using [3H] ketanserin as ligand, while the receptor number in the pontine membranes did not change. 3. These data support the involvement of central 5-HT receptors in the mode of action of ASA.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed1995

Lack of activity of azapropazone in the hot-plate test and in 5-HT1A and 5-HT2 receptor subtypes in rat brain membranes.

This study aimed to investigate the antinociceptive activity of azapropazone (AZA), a weak prostaglandin synthesis inhibitor using the hot-plate test, and its ability to modify the serotonin-binding capacity in rat brain membranes. It revealed that AZA had no antinociceptive effect in the hot-plate test at the doses of 400 and 600 mg/kg when orally administered (p.o.), and at 400, 500 and 600 mg/kg after intraperitoneal injection (i.p.). At the dose of 600 mg/kg i.p. the drug failed to modify the number and the affinity of 5-HT1A and 5-HT2 receptors in rat brain membranes. In accordance with our previous findings on a positive correlation between NSAIDs antinociception in this experimental model and changes in 5-HT receptor characteristics, these results suggest an association between the lack of AZA-mediated antinociception in the hot-plate test and the drug's inability to modify the characteristics of 5-HT1A and 5-HT2 receptor binding sites in rat brain membranes.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed1994

Lack of activity of ketorolac in hot-plate test and serotonin binding capacity of brain membranes in rats.

An increasing number of observations indicate that prostaglandin synthesis inhibition is not a satisfactory explanation for the antinociceptive activity of the non-steroidal anti-inflammatory drugs. In the hot-plate test performed 1 or 2 h after ketorolac at 40, 70 and 100 mg/kg i.p., the drug does not display any significant antinociceptive activity. Nor, at the two higher doses used, does it affect the cortical and pontine serotonin binding capacity of rat brain membranes 2 h after treatment. The data suggest that this lack of anti-nociceptive activity in the hot-plate test is associated with the drug's inability to affect the central serotoninergic system.

Analgesics↗
PubMed1994

International Headache Society classification: interobserver reliability in the diagnosis of primary headaches.

We assessed interobserver reliability of the International Headache Society (IHS) classification for diagnosis of primary headaches. The study was performed on 103 patients consecutively seen at two Headache Centres. Each patient was given a structured interview recorded on videotape. Four experienced clinicians then reviewed the interviews separately and made a diagnosis of headache according to IHS criteria at the one- and two-digit levels. At both the one- and the two-digit level the agreement was substantial (Kappa = 0.74 and 0.65, respectively). The analysis of reliability for each of nine items necessary for diagnosis showed an agreement ranging from substantial (Kappa = 0.69) to almost perfect (Kappa = 0.89). Our results indicate that the IHS classification has a good reliability for the diagnosis of primary headaches at the one- and two-digit levels.

Adolescent↗
PubMed1993

Disposition of naproxen after oral administration during and between migraine attacks.

Naproxen is an anti-inflammatory drug widely used in the management of pain and in the treatment of migraine and headache. As gastrointestinal disturbances are a common feature of migraine, the aim of this study was to evaluate the absorption and the efficacy of naproxen administered during migraine attacks. Ten patients were treated with 500 mg of a soluble form of naproxen during and between migraine attacks. Clinical parameters and drug plasma levels were recorded at scheduled times. Pain reduction, from severe to mild was evident by 6.5 +/- 3.4 hours and the total pain score showed a reduction from 2 hours onwards. Pharmacokinetic data showed a slight delay in drug absorption during attacks (absorption half-life and time of maximum drug concentration were increased during attacks), but overall bioavailability of naproxen, as reflected by area under the curve (AUC) and maximum plasma drug concentration were unchanged. Since pain relief was reported, it may be concluded that delayed absorption has little or no influence on the therapeutic effect of naproxen in migraine attacks in fasting patients.

Adult↗
PubMed1993

Effects of chronic treatment with phenazone on the hot-plate test and [3H]serotonin binding sites in pons and cortex membranes of the rat.

Many reports indicate that nonsteroidal anti-inflammatory drugs exert their antinociceptive effect through adrenergic and serotoninergic systems. We investigated the acute and chronic effects of phenazone on the pain threshold and on brain serotonin binding sites. A relationship between phenazone serum levels and the antinociceptive effect was found; acute treatment with phenazone provokes a significant decrease in serotonin binding sites both in the pons and cerebral cortex after 2, 4 and 8 h, but not after 24 h. After 15 and 30 days of treatment, the number of binding sites increases both in the pons and cortex.

Animals↗
PubMed1993

The role of serotonin brain receptors in the analgesic effect of phenazone.

The effects of treatment with para-chloro-phenyl-alanine (PCPA) (100 mg/kg i.p. for 4 days) were studied on the hot-plate test and on brain 5-HT binding in phenazone treated rats. Phenazone per se induces analgesia in the hot-plate test and decreases the number of cortical and pontine 5-HT binding sites A pre-treatment with PCPA prevents both the analgesic effect and the reduction of 5-HT binding sites caused by phenazone. These data suggest that the brain serotonin system may play a role in phenazone-induced antinociception.

Analgesics↗
PubMed1992

Plasma glutathione level in paracetamol daily abuser patients. Changes in plasma cysteine and thiol groups after reduced glutathione administration.

Since plasma reduced glutathione (GSH) seems to reflect liver GSH content, we have assessed plasma GSH in patients using paracetamol daily. In these patients a significant lower plasma GSH concentration was found with respect to controls. After the i.v. administration of GSH free plasma cysteine was 12 fold higher than in basal condition and all the pattern of plasma thiol groups was modified. This work suggests that the possible protective effect of GSH administration is due to the availability of plasma thiol compounds that enter the cell rather than GSH itself.

Acetaminophen↗
PubMed1991

Determination of naltrexone and 6 beta-naltrexol in plasma by high-performance liquid chromatography with coulometric detection.

A simple and reliable reversed-phase high-performance liquid chromatographic method with coulometric detection is described for the quantitation of naltrexone and its metabolite, 6 beta-naltrexol, in plasma samples of healthy volunteers who received orally 50 mg of naltrexone. The analytes and the internal standard, naloxone, are extracted with an octadecyl solid-phase extraction column before chromatography. The mobile phase is 0.01 M potassium phosphate (pH 3)-acetonitrile (85:15, v/v) and it is pumped at 0.8 ml/min. The coulometric detector is formed by two electrodes set at +0.20 V and +0.70 V, with a palladium reference electrode. The limit of quantitation observed was 5 ng/ml for both naltrexone and 6 beta-naltrexol. This method can be used to investigate pharmacokinetic parameters of different pharmaceutical preparations of this opioid antagonist.

Chromatography, High Pressure Liquid↗
PubMed1991

Effects of long-term treatment with naltrexone on hepatic enzyme activity.

The influence of naltrexone on liver function in heroin addicts was studied, with respect to the metabolizing function by using the antipyrine clearance and to cellular damage by monitoring plasma levels of hepatic enzymes. The clearance of antipyrine was not affected by naltrexone treatment, and, during the study period, the use and withdrawal of benzodiazepines and alcohol did not change this parameter; moreover, there was no relationship between changes in plasma hepatic enzymes and antipyrine half-life. Mean plasma levels of hepatic enzymes did not show significant modification in the course of treatment with naltrexone.

Administration, Oral↗
PubMed1991

Dapiprazole compared with clonidine and a placebo in detoxification of opiate addicts.

The activity of dapiprazole, clonidine and a placebo were studied to reduce abstinence symptoms and modify the psychological outline during a withdrawal period in heroin addicts. Forty heroin addicts were treated in a double-blind design and, within two weeks, relapse in heroin use was higher in the placebo group (8/10) in comparison with the dapiprazole (1/20) and clonidine (0/10) groups. During treatment clonidine was able to reduce depression and paranoid-ideas scores, whereas dapiprazole reduced depression, anxiety, hostility, phobic anxiety, obsessiveness and psychoticism. Side-effects were mild and it may be concluded that both dapiprazole and clonidine are effective and safe drugs for the treatment of opiate withdrawal syndrome.

Adolescent↗
PubMed1990

Pharmacokinetics of tiaprofenic acid after oral administration in fasting patients during and between migraine attacks.

This study examined the pharmacokinetics of 300 mg of tiaprofenic acid, a NSAID belonging to the 2-arylpropionic class, as a single oral dose, in 10 migraine patients during and out of migraine attacks. Plasma concentration of tiaprofenic acid was determined by HPLC analysis. Drug absorption appeared to be the same during and out of migraine attacks (absorption half life: during attack, 0.249 +/- 0.122 hr; out of attack, 0.249 +/- 0.105 hr; maximum plasma concentration: during attack, 37.8 +/- 9.8 ug/ml; out of attack, 40.1 +/- 13.2 ug/ml). The other pharmacokinetic parameters evaluated were not affected by headache attacks as well. We conclude that tiaprofenic acid absorption and metabolism are not affected by migraine attacks. Also, our data suggest that tiaprofenic acid might be useful in the treatment of migraine.

Administration, Oral↗
PubMed1989

Influence of antacids on the bioavailability of glibenclamide.

A single oral dose of glibenclamide (2.5 mg) was given to eight healthy volunteers in a randomized cross-over study after a standardized fasting and breakfast (374 kcal), with or without a concomitant intake of 10 ml of antacid suspension. Serum glibenclamide levels were determined by means of a specific radioimmunoassay method. The areas under the blood concentration-time curves (AUC0-infinity), with or without antacid, were 408.17 +/- 168.25 and 307.9 +/- 84.13 ng/ml (p less than 0.05), respectively. The peak concentrations of 96.88 +/- 49.9 and 66.19 +/- 32.35 ng/ml/h (p less than 0.05) with or without antacid, were reached in 4.13 and 3.81 h, respectively. Values of tmax, Vd and t1/2 were not affected by the presence of the antacid. A 33% increase in bioavailability of glibenclamide emerged, as seen from the respective AUC values, but no clinically remarkable effect was observed in the subjects.

Adult↗