Photocatalytic activity of TiO2/SiO2 systems.

Silica-supported TiO(2) powders were synthesized by a wet method under mild conditions. The aim of the work was the preparation of TiO(2)/SiO(2) additives for photocatalytic cements. Three types of commercial SiO(2) were used as supports: Cabot, Axim and Fly Ash. Cabot silica was ultra-pure whereas the other two silica contained different percentages of various oxides. The TiO(2)/SiO(2) samples, denoted TiO(2)/Cabot, TiO(2)/Axim and TiO(2)/Fly Ash, were prepared by boiling suspensions obtained by addition of silica to a solution of TiCl(4) in water (volume ratio 1:10). The photocatalytic activity was evaluated in a gas-solid system both in batch and in continuous reactors using 2-propanol as probe molecule. SEM-EDX analysis revealed that titanium dioxide was quantitatively deposited on silica. TiO(2)/Axim and TiO(2)/Fly Ash were scarcely active whereas a good photoactivity was exhibited by the TiO(2)/Cabot sample both in the batch and in the continuous system. Consequently only the last sample was tested for both NO(x) abatement and for 4-nitrophenol photodegradation in a liquid-solid system.

The uncertainty associated with the predictive value of test results.

The uncertainty associated with predictive value of test results was taken into consideration, as concerns both sampling error (related to the size of the statistical reference samples) and analytical imprecision (unavoidably involved by the measurement itself). A software package, developed for the statistical calculations, was used for the treatment of the results obtained for serum free thyroxin in euthyroid and dysthyroid subjects, assumed as an experimental model. Examples are shown for the obtainable functions predictive value vs. estimate and the related uncertainty regions. These data could help in comparing test results and, in particular, in preparing fully informative laboratory reports. The difficulties involved by an extensive application of the procedure are discussed.

The effects of thymomodulin and thymolymphotropin on the stress response of neuroendocrine system by gamma-irradiated Wistar rat.

Thymomodulin and Thymolymphotropin, biologically active thymus derivative peptides exert recovery effects on the functionality of some membrane bound, mitochondrial and lysosomal enzymes (monoamine oxidase, ATPase, phosphatases, cytochrome oxidase, succinate oxidase) affected by gamma-irradiation. These drugs exert antistress effect by re-establishing the function of hypothalamus-pituitary-adrenal axis and that of lymphoid organs.

Determination of nuvenzepine in human plasma by a sensitive [3H]pirenzepine radioreceptor binding assay.

A sensitive method for the quantitation of small amounts of nuvenzepine, a new M1-selective antimuscarinic drug, in plasma is described. The analytical method involves the use of a radioreceptor binding assay based on [3H]pirenzepine displacement in rat cerebral cortex homogenates; no previous extraction is required. The method is reliable, with an interassay CV ranging from 5 to 10%, and allows the analysis of greater than 100 samples/experiment. The limit of detection is approximately 0.1 ng/assay. Using this method we have determined the plasma levels of nuvenzepine in eight healthy volunteers treated PO with 15 or 25 mg of nuvenzepine.HCl. The pharmacokinetic parameters obtained were (for 15 and 25 mg): Cmax, 64 and 131 ng/mL; AUC0-infinity, 851 and 1379 ng.h/mL; t1/2, 8.6 and 7.2 h. These values are in good agreement with those obtained using an HPLC method. Therefore, this radioreceptor binding assay proved to be simple, rapid, and specific for the determination of low levels of nuvenzepine in human plasma.

Linearity of levodropropizine, a new antitussive drug, in the healthy volunteer.

The object of this study was to determine whether the pharmacokinetics of levodropropizine were linear. Twelve healthy adult male volunteers received oral doses use of 30, 60 and 90 mg of levodropropizine. A cross-over design was used. With the exception of Cmax, and AUC the pharmacokinetics of levodropropizine in the dose range studied are similar. The relationship between the doses and AUCs and the statistical comparison of AUCs (Anova test and Westlake test) confirm that in the range 30-90 mg the plasma pharmacokinetics of levodropropizine are linear.

Inhibitory effects of DF 594, a new antispasmodic agent, on intestinal motility in the dog.

DF 594, 11-(N-methylnipecotyl)-6,11-dihydro-5H-pyrido[2,3-b]-1,5-benzod iazepin-5-one hydrochloride, is a new antimuscarinic compound endowed with high affinity for intestinal muscarinic receptors and showing potent inhibitory effects on intestinal motility. This study investigated the intestinal motor effects of DF 594 in fasting, conscious dogs, chronically fitted with electrodes and strain gauges along the small bowel. In a first series of experiments, we assessed the antispasmodic activity of the compound by comparing the ability of intravenous DF 594 or atropine to antagonize the stimulatory effect of bethanechol (100 micrograms/kg s.c.). ED50 values for inhibition of bethanechol-stimulated contractions were 13.9 (8.8-21.8) and 4.0 (1.8-8.7) micrograms/kg for DF 594 and atropine, respectively. In a second series of experiments, we evaluated the effects of intravenous DF 594 and atropine on the migrating motor complex (MMC), monitoring heart rate as well. Similarly to atropine (30-100 micrograms/kg), DF 594 (100-300 micrograms/kg) blocked the further migration of an ongoing MMC and significantly delayed the onset of the following MMC. Unlike atropine, DF 594 had only a minor effect on heart rate at the highest dose tested (300 micrograms/kg). These data indicate that DF 594 is an effective antispasmodic agent at doses lower than those required to interfere with the MMC and is also less likely than atropine to induce cardiac side effects.

Synthesis and pharmacological screening of new phenylpiperazinepropane derivatives and their enantiomers.

Enantiomers of phenylpiperazinepropane-1,2-diol derivatives were synthesized with the purpose to obtain a better antitussive activity/sedative effect ratio. (S)-isomers showed better pharmacological profiles than (R)-isomers and corresponding racemates. Among the (S)-isomers, the unsubstituted compound, levodropropizine (S(-)-3-(4-phenyl-piperazin-1-yl)-propane-1,2-diol, DF 526), has the most favourable antitussive activity/sedative effect ratio and was selected for pharmaco-toxicological evaluation.

General pharmacology of the new antitussive levodropropizine.

The general pharmacological profile of levodropropizine (S(-)3-(4-phenyl-piperazin-1-yl)-propane-1,2-diol, DF 526), a new antitussive drug, was compared with that of dropropizine racemate. Levodropropizine had weaker central sedative effects than the racemate and it did not induce physical dependence in rats. When given intravenously or intraperitoneally, levodropropizine did not exert any significant effects on the cardiovascular and respiratory systems. Receptor binding data excluded interaction with beta-adrenergic, muscarinic and opiate receptors. On the contrary, levodropropizine has affinity for H1-histaminic and alpha-adrenergic receptors. The affinity was also confirmed with isolated organ preparations. On the basis of this study, levodropropizine appears to have a better tolerability index than the racemate.

Antitussive properties of levodropropizine.

The antitussive activity of levodropropizine (S(-)-3-(4-phenyl-piperazin-1-yl)-propane-1,2-diol, DF 526), was evaluated in anaesthetized guinea-pigs and rabbits and in unanaesthetized guinea-pigs. Levodropropizine was shown to have good antitussive activity. Intravenously, it was 1/10 to 1/20 as active as codeine and comparable to dropropizine, from which it is derived, on mechanically and electrically induced coughing in rabbits and guinea-pigs. After oral administration to the guinea-pig the antitussive activity of levodropropizine was comparable with those of both dropropizine and codeine against coughing induced by irritant aerosols.

Role of endogenous prostaglandins in protection of rat gastric mucosa by tripotassium dicitrate bismuthate.

Gross and microscopic examination of rat gastric mucosa demonstrated that intragastric administration to rats of tripotassium dicitrate bismuthate (TDB), a colloidal bismuth compound, protects against gastric lesions induced by 85% ethanol. Indomethacin, a prostaglandin synthetase inhibitor, significantly blocked the gastric mucosal protective effect of TDB. The release of gastric mucosal prostaglandins was greater in animals treated with TDB than in control animals, both time- and dose-dependently. These results seem to indicate involvement of prostaglandins in the action of TDB.

Effectiveness and tolerability of ketoprofen lysine, once a day, in patients with rheumatic disorders.

Ketoprofen lysine (KL) at a dose of 160 mg b.i.d. has been shown to have favourable anti-inflammatory and analgesic properties in a large number of patients. In the present paper investigators describe their experience with a new therapeutic schedule of KL, 320 mg given once a day to patients with various rheumatic disorders. With this new schedule there was satisfactory clinical improvement of most of the clinical parameters and good tolerability, with a low incidence of gastric troubles. The favourable clinical effects and the patients' good compliance with once-a-day KL make it a useful drug for successful treatment of rheumatic disorders.

Effects of suprofen on renal function in patients with rheumatoid arthritis.

Suprofen is a new potent analgesic with antiinflammatory properties that appears to inhibit prostaglandin synthetase in a tissue-selective manner, having relatively little effect on the kidneys of experimental animals. The effects were studied of one week of treatment of rheumatoid arthritis patients with suprofen or ibuprofen on Na+ and K+ excretion, creatinine clearance, urinary enzymes that are markers for tubular damage, and urinary prostaglandins such as PGE2 and 6-keto PGF1 alpha (a stable metabolite of prostacyclin). Neither compound caused changes in renal function related to the week of treatment, but significant decreases in prostaglandins were observed: this change was fully reversible after discontinuation of the drug.

Gastric pharmacological activities of tripotassium dicitrato bismuthate in rats and dogs.

The effects of tripotassium dicitrato bismuthate (TDB) on gastric acid, pepsin and mucoprotein secretion in rats and on hydrochloric-peptic secretion and plasma gastrin levels in dogs were investigated. In Shay rats, TDB did not affect acid secretion but significantly lowered pepsin concentration and increased the amount of bound mucoproteins. In addition, gastric mucosal lesions were significantly prevented by the drug. In dogs, chronically fitted with both gastric fistulae and Heidenhain pouches, acid secretion and plasma gastrin levels stimulated by a meat meal were unaffected by TDB, while pepsin concentration and pepsin output were significantly decreased. On the basis of these results, the antiulcer activity of TDB appears to be ascribed to the protection of the gastric mucosa through an increase in mucoprotein synthesis and a decrease of pepsin activity.

Degradative behavior of cadralazine in aqueous solution.

The degradation of cadralazine in aqueous solution was investigated in relation to pH, concentration, and temperature, under aerobic and anaerobic conditions in light and dark. The appearance of three main degradation products was also studied. Drug disappearance was dependent on temperature, pH, concentration, and oxygen and followed three different mechanistic pathways: thermal, hydrolytic, and oxidative. The individual rate constants were determined by nonlinear regression fitting.

Prevention of gastric mucosal lesions in rats by tri-potassium di-citrato bismuthate.

Tri-potassium di-citrato bismuthate given intragastrically to rats 60 min before administration of necrotizing agents such as 85% ethanol, 0.2 N sodium hydroxide or acidified indomethacin, reduced the formation of mucosal lesions dose-dependently. Prostaglandin I2 (PGI2)-like material, determined by bioassay, was higher in the gastric mucosa of animals treated with bismuth subcitrate complex than in control animals.

Pharmacokinetics of a slow-release preparation of ketoprofen lysine in man.

The lysine salt of 2-(3-benzoylphenyl)propionic acid (ketoprofen lysine) was administered at the dose of 160 mg either in two conventional capsules (Artrosilene) or in one slow-release capsule in a randomized sequence to 8 volunteers. Serum and urine concentrations of ketoprofen were determined by HPLC. The slow-release preparation had a bioavailability greater than 90% as compared with the conventional capsule and produced lower and longer lasting ketoprofen serum levels. These results suggest that two daily administrations of the new formulation should be suitable for therapeutic use.