Evidence for a different sensitivity to various central effects of interleukin-1 beta in mice.

Interleukin 1 (IL-1) induces a series of metabolic and endocrine effects. Activation of the hypothalamus-pituitary-adrenal axis, inhibition of food and water intake, elevation of serum interleukin-6 (IL-6) concentration and hypoglycemia are some of the effects induced by IL-1. The purpose of this study was to compare the sensitivity of these effects following central and peripheral administration of IL-1 beta. Different doses of IL-1 beta (0.1-1000 ng/mouse) were centrally (ICV) or peripherally (IP) injected to male mice two hours prior to sacrifice. The ICV administration was more efficacious than the IP injection in elevating serum corticosterone and IL-6 concentrations, whereas no difference was evident in the IL-1 beta-induced hypoglycemia. Central IL-1 beta administration was also more potent than IP injection in inhibiting overnight food and water intake. A dose-dependent effect was evident in all these cases. In summary, our data compare effects elicited by central or peripheral administration of different doses of IL-1 beta. This comparison suggests that the IL-1 beta stimulation of serum corticosterone and IL-6 and inhibition of food and water intake are events more centrally mediated than the IL-1 beta-induced hypoglycemia.

The specific binding of broxaterol, a new beta 2-selective agonist, to beta-adrenoceptors.

The specific binding of broxaterol, a potent new orally active antiasthmatic drug, to beta 1- and beta 2-adrenoceptors was characterized by receptor binding studies with rat heart and lung membrane preparations. Broxaterol showed high affinity and selectivity for the beta 2-component of [3H]dihydroalprenolol binding in both lung (58% beta 2-sites, Ki = 130 nM) and heart membranes (19% beta 2-sites, Ki = 98 nM), whereas the binding to the beta 1-component was at lower affinity (42% beta 1-sites, Ki = 4100 nM in the lung and 81% beta 1-sites, Ki = 3460 mM in the heart). The influence of temperature changes on the binding properties of broxaterol towards beta-adrenoceptors was also investigated. A marked increase in the affinity of broxaterol for lung beta-receptors was observed on lowering the assay temperature, whereas the affinity for heart beta-receptors was little affected by temperature changes. Thermodynamic analysis of the binding data showed that the binding of broxaterol as well as isoproterenol to lung beta-receptors was associated with a large decrease in enthalpy, which correlates well with the full agonistic properties of this compound at beta 2-receptors.

Synthesis and in vitro antibacterial properties of 2-(3-bromo-5-isoxazolylideneamino-oxy)acetamido-beta-lactam derivatives.

The synthesis of new 2-(3-bromo-5-isoxazolylideneamino-oxy)acetic acids and their condensation derivatives with suitable beta-lactam nuclei is reported. Their antibacterial properties have been tested in vitro. An interesting activity against Gram-positive bacteria including beta-lactamase-producing microorganisms was found among the cephalosporanic acid derivatives.

N-(4-Isoxazolylthiazol-2-yl)oxamic acid derivatives as potent orally active antianaphylactic agents.

A series of N-(4-isoxazolylthiazol-2-yl)oxamic acid derivatives was synthesized and tested on the passive cutaneous anaphylaxis (PCA) model in rats to verify its potential antianaphylactic activity. These compounds were prepared by reaction of an appropriate bromoacetylisoxazole with thiourea to give the corresponding aminothiazole and subsequent condensation with an oxalic acid monoester chloride to yield, following the usual process, the oxamic acid derivatives. Most of the new compounds exhibited, by intraperitoneal route in rats, a very potent antianaphylactic activity on PCA response, higher than that of the reference compound disodium cromoglycate (DSCG). The new derivatives, in contrast with DSCG, were effective on PCA even by oral route. The most interesting derivative of the new series was N-[4-(3-methyl-5-isoxazolyl)-2-thiazolyl]oxamic acid 2-ethoxyethyl ester (49), which was also active and more potent than DSCG in experimental models involving either IgE- or IgG-mediated anaphylactic responses at bronchopulmonary level.

Multicenter trial with ubidecarenone: treatment of 44 patients with mitochondrial myopathies.

Fourty four patients with mitochondrial myopathies were treated with Ubidecarenone (CoQ10) for six months in an open multicentric trial. No side effects due to the drug administration were observed. Sixteen patients showing at least 25% decrease of post exercise lactate levels were selected as responders. Responsiveness was apparently not related to CoQ10 level in serum and platelets or to the presence or absence of mtDNA deletions. The responders were further treated for 3 months with CoQ10 or placebo in the second blind part of the trial; no significant differences between the 2 groups were observed. It is not clear why CoQ10 had therapeutic effects in some patients and not in others with the same clinical presentation and biochemical defect, and we failed to identify candidate responders before treatment. At the dosage of CoQ10 used in the study (2 mg/kg/day) the therapy requires long administration time before a response is demonstrable.

Determination of N-acetylcysteine in human plasma by gas chromatography-mass spectrometry.

An automatic mass spectrometric method for the quantitation of N-acetylcysteine (NAC) in human plasma has been developed. NAC was extracted from plasma with ethyl acetate and derivatized in two steps with 2-propanol and pentafluoropropionic anhydride. The volatile derivative obtained was ideal for gas chromatographic-mass spectrometric analysis. Data obtained by analysing the plasma of healthy volunteers to whom 600 mg of NAC had been orally given are reported.

Intraventricular infusion of epidermal growth factor restores dopaminergic pathway in hemiparkinsonian rats.

We assessed the effect of a 35-day delayed intracerebroventricular (ICV) infusion of epidermal growth factor (EGF) on the survival and function of the substantia nigra (SN) dopaminergic neurons after a unilateral mechanical transection of rat nigrostriatal pathway. EGF infusion for 28 days resulted in a twofold increase in the number of surviving tyrosine-hydroxylase (TH)-positive SN neurons and a significant increase in ipsilateral striatal TH-positive fiber staining compared to controls at 200 days following the injury. In addition, there was a persistent enhancement of behavioral recovery, as indicated by a reduction in amphetamine-induced rotations. We conclude that EGF exerts a neurotrophic effect on the dopaminergic neurons in this experimental model of parkinsonism.

n-hexane induces parkinsonism in rodents.

A case of human parkinsonism, due to n-hexane exposure, was recently described. On the basis of this observation, we treated mice and rats with n-hexane and its principle toxic metabolite 2,5-hexanedione. The mice underwent a chronic treatment intraperitoneum, the rats were treated stereotaxically into the substantia nigra. At biochemical analysis of the striata, dopamine and homovanillic acid levels were significantly lower compared with control animals; norepinephrine, serotonin, 5-hydroxindolacetic acid levels were unchanged. The rats treated with 2,5-hexanedione showed an apomorphine-induced rotational behavior significantly higher compared to controls. Since n-hexane and its metabolites are environmental contaminants and by-products of endogenous metabolic pathways, we propose that they may play a role in inducing parkinsonism in humans.

New isoxazole derivatives provided with antihypertensive activity.

A series of diazacycloalkane-quinazoline derivatives of isoxazoles were synthesized and tested in order to identify new potent and selective alpha 1-antagonists. A preliminary screening by using in vitro tests such as binding assay (3H-prazosin and 3H-rauwolscine displacement) and analysis of antagonistic activity in isolated rat aorta (norepinephrine-induced response) and in isolated rat vas deferens (clonidine-induced response) indicated that many of these compounds exhibited a good affinity and selectivity towards alpha 1-adrenergic receptors associated with potent pharmacological activity. In particular, a 3-bromo-5-isoxazolecarbonyl derivative, selected for further in vivo investigation, was provided with as high antihypertensive action as prazosin in spontaneously hypertensive rats (SHR) coupled to a shallow dose-response curve by oral route. Moreover, a higher ratio between oral antihypertensive doses in SHR and normotensive rats was found with respect to reference compound prazosin.

Clinical and biochemical correlations in mitochondrial myopathies treated with coenzyme Q10.

We tested the efficacy of coenzyme Q10 (ubidecarenone, CoQ10) therapy in patients with Kearns-Sayre syndrome and other mitochondrial myopathies with chronic progressive external ophthalmoplegia (CPEO). We treated seven patients for 1 year with daily oral administration of 120 mg of CoQ10. Throughout the treatment most of our patients showed a progressive reduction of serum lactate and pyruvate levels following standard muscle exercise and generally improved neurologic functions. The ECG and echocardiogram showed no significant changes in our patients. None of our patients showed any improvement in ptosis and CPEO.

Synthesis and antibacterial properties of 7-[2-(3-substituted-5-isoxazolyl)-2-methoxyiminoacetamido]cep halospora nic acid derivatives.

The synthesis of new 2-(3-substituted-5-isoxazolyl)-2-methoxyiminoacetic acids and their condensation derivatives with a suitable cephalosporanic nucleus, is reported. Their antibacterial properties were tested in vivo and in vitro also against beta-lactamase producer microorganisms; particularly the oral bioavailability of some of these new derivatives was studied.

Influence of opioids on beta-receptors down-regulation: studies in cultured C6 glioma cells.

Opioids' modulation of beta-receptors' density and function has been investigated in a cultured cell line system. Rat C6 glioma cells do not have opioid receptors or, at least, the number of these receptors is very low, but cell exposure to desmethylimipramine (DMI) causes expression of functional opioid receptors as indicated by the increased [3H]DHM binding and by the acquired ability of opioids to inhibit ISO-stimulated cAMP accumulation. Cell exposure to DMI also causes beta-receptors' down-regulation as indicated by the decline in [3H]DHA binding coupled to a reduced ability of isoproterenol (ISO) to stimulate cAMP accumulation in intact cells. In the present paper we show that cell exposure to opioid agonists during DMI treatment counteracted DMI-induced beta-receptor loss. Similarly, opioid agonists added at the beginning of ISO exposure in DMI-pretreated cells, inhibited ISO-induced beta-receptor tachyphylaxis. These results suggest that opioids may exert a protective effect on beta-receptor function and this appears to be a common mechanism which is operant when overstimulation of beta-receptors takes place.

New isoxazole derivatives with a potent and selective beta 2-adrenergic activity.

A series of 1-(3-subst-5-isoxazolyl)-2-alkylaminoethanol derivatives was synthesized and tested in order to evaluate the effectiveness of the isoxazole ring in replacing the catechol moiety of beta-adrenergic compounds. Direct binding studies and the influence on beta-receptors mediated responses in isolated guinea-pig atria and guinea-pig trachea were investigated to determine the pharmacological profile of the new derivatives. The results indicate that some derivatives with proper substitution in the isoxazole ring and in the aminoalcohol chain displayed a marked selectivity towards beta 2 tracheal receptors. In vivo studies confirmed this profile, and the derivative 1-(3-bromo-5-isoxazolyl)-2-tert.butyl aminoethanol hydrochloride was selected and further developed as a potential bronchodilatory agent.

Opioids and beta-receptors interaction: further studies in cultured cells.

In the present paper a further evidence of a functional link between opioids and beta-receptor system in cultured rat C6 cells is presented. We showed that C6 cell exposure to Desmethylimipramine (DMI) causes expression of opioid receptors and loss of beta-receptors. We now show that C6 cells exposure to DMI causes an increase of intracellular levels of opioid peptides and an increase of aminopeptidase activity. In addition, the presence of the aminopeptidase inhibitor bestatin during cell exposure inhibits DMI-induced beta-receptor loss. These results indicate that cell exposure to DMI causes the full expression of the opioid peptide system. This effect could be related to changes of beta-receptor system.

Involvement of monoaminergic and peptidergic components in cathinone-induced analgesia.

Evidence has been obtained suggesting that cathinone-induced analgesia depends upon stimulation of alpha-adrenoceptors, followed by release of opioid peptides and by activation of serotonergic pathways. This hypothesis is supported by the following. (1) Cathinone potentiated morphine analgesia and the whole effect was antagonized by naloxone whereas onto the cathinone potentiation was counteracted by phenoxybenzamine. (2) Bestatin potentiated cathinone-induced analgesia and this effect was sensitive to both naloxone and phenoxybenzamine blockade. (3) The analgesic effect of cathinone + bestatin was further potentiated by the serotonin uptake inhibitor citalopram.

Cigarette smoke and N-acetylcysteine: interference with the bactericidal properties of serum.

The bactericidal properties of normal serum are an important feature in host defence; it has been suggested that they are depressed by cigarette smoke. The aim of the present study was to investigate the in vitro depressant effect of cigarette smoke on antibacterial activity of rabbit serum and its interaction with the well-known antioxidant agent, N-acetylcysteine. Escherichia coli was used to study the bactericidal activity of the complement-dependent system and Staphylococcus aureus was used to study the thermostable bactericidal system. It was found that exposure of serum and bacteria to cigarette smoke significantly decreased the bactericidal powder of serum; when N-acetylcysteine was added to the incubation mixture, however, a marked inhibitory effect on the toxic action of smoke on rabbit serum was observed.

Effect of bestatin and thiorphan on [Met5]enkephalin-Arg6-Phe7-induced analgesia.

We investigated the effect of bestatin, a specific inhibitor of aminopeptidase and thiorphan, a specific inhibitor of enkephalinase A, on the analgesic effect induced by the intracerebral injection of heptapeptide [Met5]enkephalin-Arg6-Phe7 (MEAP) in cannulated rats. In contrast with the results obtained when [Met5]enkephalin (ME) was used, bestatin clearly potentiated the analgesic effect of MEAP, but thiorphan was totally ineffective. These observations indicate that the predominant inactivating mechanism for MEAP is the action of an aminopeptidase whereas this enzyme seems to be little involved in the catabolism of ME. The existence of two different catabolic pathways for MEAP and ME suggests that MEAP may act not only as a precursor of ME but also as an independent neuromodulator.

In vitro antibacterial activity of thiamphenicol.

This in vitro study of thiamphenicol activity against 247 strains of Gram-positive and 195 strains of Gram-negative pathogenic bacteria showed no significant changes from past activity. Of the 442 strains involved, thiamphenicol proved: - Effective (MIC = less than or equal to 0.5-4 micrograms/ml) against 131 strains, mostly streptococci, pneumococci and enterococci. - Moderately effective (MIC = 8-64 micrograms/ml) against 252 strains, mostly staphylococci, Salmonella, Citrobacter, K. pneumoniae, Enterobacter, E. coli and Proteus. - Ineffective (MIC = 64 micrograms/ml) against 59 strains, mostly Proteus, E. coli and K. pneumoniae. Against 23 strains of Neisseria gonorrhoeae, thiamphenicol generally proved as effective as penicillin G and cefuroxime and more effective than spectinomycin.

Methionine-enkephalin, substance P, and homovanillic acid in the CSF of parkinsonian patients.

Methionine-enkephalin, substance P, and homovanillic acid concentrations were measured in the CSF of subjects not affected by neurologic disorders (group 1), and in parkinsonian patients who had a slight or moderate (group 2) or severe (group 3) disability. Homovanillic acid and substance P concentrations in the CSF of groups 2 and 3 were respectively lower and higher than in group 1. On the contrary, an increase in CSF methionine-enkephalin content was found only in group 2. Our results confirm in humans the close relation between the dopaminergic and peptidergic transmissions in the nigrostriatal system that has been observed in experimental animals.