Double-blind trial of dexamethasone versus methylprednisolone in multiple sclerosis acute relapses

The efficacy of dexamethasone (DX) and methylprednisolone (MP) at high (HD) and low (LD) dose in acute multiple sclerosis (MS) relapses was evaluated by a double-blind trial in 31 patients followed for 1 year. DX and HDMP were similarly efficacious in promoting recovery, while LDMP was ineffective in the short-term outcome and was followed by an early clinical reactivation. The different outcomes seem to be related to different immunomodulating effects, mainly on cerebrospinal fluid (CSF) IgG synthesis and on peripheral blood and CSF CD4+ lymphocyte subsets.

Phenotype analysis of unstimulated lymphocytes and anti-CD3-stimulated proliferating T-cells from cerebrospinal fluid and peripheral blood in patients with multiple sclerosis and other neurological diseases

In 15 patients with multiple sclerosis (MS) and in 11 patients with other neurological diseases (OND), the phenotype of fresh unstimulated CSF and PB mononuclear cells and of "in vitro" expanded T-cells was studied by monoclonal antibody stain and cytofluorimeter analysis. A compartment-specific decrease of CD8+Leu8+ and CD8+Leu8- cells in CSF was detected; moreover, lower levels of CD8+Leu8- cells were seen in MS than in OND patients, both in CSF and in PB. Although the percentages of unstimulated CSF CD4+ cells did not differ between MS and OND, a higher proportion of "in vitro" expanded CD4+ T-cells was obtained from MS patients than from OND. Among MS patients, T-cell growth was very scarce or absent in those sampled during relapses. The results suggest alterations both within the CD4+ "helper" and the CD8+ "suppressor-cytotoxic" populations in the CSF of MS patients, and stress the relevance of functional analysis in conjunction with phenotype studies.

Short and medium-term influence of physical activity on immune parameters

Physical stress induces different changes in immune parameters depending on effort schedule and/or customary physical training. The mechanisms whereby they take place and the occurrence of possible tolerance after repeated effort have not been conclusively elucidated. We studied short and medium-term exercise-induced changes in immune parameters after a standard physical effort (24' of cycle ergometer up to the 80% of maximal heart rate, daily for 5 days) in a group of healthy untrained controls. White Blood Cells, lymphocyte subsets, plasmatic catecholamine and cortisol levels, IgG and IL2receptor (IL2R) levels were determined. Most of the observed changes were strictly acute effort-related and disappeared within 3 hours (except for shifts in CD4+ CD45RA+ and CD4+ CD45RA- lymphocytes): they were concomitant to a transient sympathetic activation proved by heart rate (HR) and Norepinephrine (NE) increase. The medium-term effects of repeated daily effort included only a questionable rise in CD19+ and CD3+ CD4- CD8- cells. As far as possible tolerance mechanisms are concerned, we did not detect any change in either the direction or the entity of effort-induced changes in our controls after repeated effort. Study of strictly standardized exercise protocols is mandatory before clinical applications of physical activity in the approach to the treatment of disimmune diseases.

Presence of T-cell subset abnormalities in newly diagnosed cases of multiple sclerosis and relationship with short-term clinical activity

Abnormalities of T-cell subsets in patients with multiple sclerosis are well known; in order to assess whether immunological abnormalities are relevant in the pathogenesis of the disease after its clinical onset, peripheral blood lymphocyte subsets (CD3+, CD4+, CD4(+)-CD45RA+, CD4+CD45RA-, CD8+, CD8+CD57+, CD57+, CD25+) were analysed serially in 25 patients at the first clinical episode suggestive of inflammatory demyelinating disease and in an equal number of age- and sex-matched controls. During the follow-up period (12-18 months, mean 14) 6 of 25 patients presented new relapses: in this subgroup of patients, significant changes in CD4+ ratio (% CD4+CD45RA-/%CD4+CD45RA+) were detected in comparison both with healthy controls and with clinically stable patients. Patients clinically stable at follow-up did not display immunological abnormalities, regardless of the presence or absence of cerebrospinal fluid and/or magnetic resonance imaging alterations consistent with multiple sclerosis. These findings suggest a possible prognostic role of early T-cell subset imbalance in multiple sclerosis.

Physical effort-induced changes in immune parameters

Physical stress induces changes in immune system parameters; these changes depend on effort schedule and are influenced by customary training. The mechanisms whereby they take place are not fully elucidated: sympathetic activation-mediated mobilization of cells of lymphoid organs, including the spleen, has been suggested. We studied exercise-induced changes (20' of cycloergometer test conducted up to 80% of maximal expected heart rate) in white blood cells (WBC), lymphocyte subsets, plasma catecholamine and cortisol levels in three groups of subjects: swimmers, untrained controls and splenectomized individuals. Physical exercise induced increase of WBC and significant changes in the percentage of most investigated lymphocyte subsets (NK, CD3+, CD4+, CD8+ and CD4/CD8 ratio), except for DR+ cells. No changes occurred in the percentage of CD14+ cells. Norepinephrine (NE) levels increased after effort, while epinephrine (E) and cortisol levels were unchanged. Splenectomized patients displayed similar effort-induced changes in investigated parameters as controls and swimmers. The results support the interactions between physical work and immune response and minimize the role of the spleen in this context.

Immunological alterations in cluster headache during remission and cluster period. Comparison with low back pain patients

Cluster headache is a disorder of unknown origin. Some studies have focused their attention on neuroendocrine derangement, others on immunity. To probe central alterations in cluster headache (CH), immune parameters were investigated in cluster headache patients in comparison to low back pain patients and healthy controls. Increases in peripheral blood monocytes found in remission cluster headache patients may be attributable to chronic central nervous system (hypothalamic?) noradrenergic dysfunction or altered beta-endorphin. Alterations in NK+, CD3+ and CD4+ levels found in cluster period cluster headache and low back pain patients are probably pain or stress-related.

[The definition of a reference protocol for the clinical study of vertigo drugs]

The aim of this paper is to define the problems that arise in the clinical evaluation of drugs for the treatment of vertigo. Among these are the objective criteria used in defining vertigo and those used in evaluating efficacy of the drugs. The resulting protocol for a clinical study of vestibular drugs is a document that clarifies the debated points in the field, and above all furnishes guidelines for establishing uniformity in clinical studies. This, therefore, may become the reference protocol in Italy for clinical evaluations of drugs for the treatment of vertigo.

Metabolism rate of oxodipine in rats and humans: comparison of in vivo and in vitro data

The in vitro metabolism of oxodipine was studied with rat and human hepatic and intestinal microsomes. Rat liver, human liver and intestine were able to metabolize oxodipine in vitro to the main metabolites found in vivo, namely pyridine and deesterified derivatives; rat intestine did not produce any detectable metabolite. The Kms were found to be in the range of 30 to 60 microM. Human in vitro intestinal metabolism was negligible compared to that of liver and, taking into account the dose administered, it was predicted that the intestinal first-pass effect would also be negligible in vivo. The use of in vitro kinetic constants enabled us to evaluate the amount of oxodipine metabolized and to compare it to values found in vivo. Both results were on the same order of magnitude, indicating that it might be possible to evaluate the in vivo metabolism from in vitro data. Finally, we clearly showed, by substrate inhibition and immunoinhibition, that oxodipine was metabolized by the cytochrome P4503A subfamily both in intestine and in liver.

Plasmid-encoded determinants for bacteriocin production and immunity in a Lactococcus lactis strain and purification of the inhibitory peptide

Lactococcin, a bacteriocin produced by Lactococcus lactis subsp. lactis ADRIA 85LO30, was purified as a 2.3-2.4 kDa peptide. Six non-bacteriocin-producing (Bac-) and non-immune (Imm-) strains were isolated after curing experiments. These strains had in common the loss or modification of two plasmids: pOS4 (32 kb) and pOS5 (70 kb). By comparing pOS5 and several modified plasmids, a DNA region from pOS5 of about 10 kb, which was necessary for wild-type bacteriocin production and immunity, was identified.

Use of particle beam liquid chromatography-electron impact mass spectrometry for structure elucidation of oxodipine and three of its metabolites

In order to test the analytical capabilities of the particle beam liquid chromatograph-mass spectrometer interface in structural identification in drug metabolism, a liquid chromatographic-mass spectrometric (LC MS) method using this new technique was developed for oxodipine and some of its expected metabolites. After two extraction steps at pH 9 and 1.5, the separation of the compounds, which have a wide polarity range, was carried out by an isocratic high-performance liquid chromatographic method with a 25-cm cyano-bonded column. The compounds were eluted with hexane-methanol-methylene chloride (76:12:12). Mass spectra were recorded after electron impact ionization (75 eV) with a source temperature of 150 degrees C. Under these conditions, comparison of the spectra with those obtained after gas chromatography or with a direct introduction probe showed identical fragmentation patterns when a sufficient amount of product was injected for LC-MS analysis.

Cardiac electrophysiological effects of cibenzoline in the conscious dog: plasma concentration-response relationships

The cardiac electrophysiological effects of cibenzoline were studied in the conscious dog. Sinus rate, corrected sinus recovery time (CSRT), and Wenckebach point (WP) were measured in six intact dogs. Atrial and ventricular rates, and atrial effective refractory period (AERP) were measured in seven atrioventricular (AV)-blocked dogs. In both groups, blood pressure and cibenzoline plasma concentrations were also monitored. Each dog received three intravenous injections of 0.75, 1.5, and 3 mg base/kg cibenzoline 30 min apart. Cibenzoline increased sinus and atrial rates from the second dose onward, and ventricular rate slightly at the third dose. It lengthened CSRT and decreased WP at the first two doses only, and increased AERP from the first dose onward. In both groups, cibenzoline increased mean blood pressure at each dose. Taken together, these results indicate that in the conscious dog, cibenzoline at low plasma concentrations exhibits electrophysiological effects (lengthening of CSRT and AERP, and decrease in WP) attributable to its antiarrhythmic properties, and that at increasing concentrations it produces effects (increase in sinus rate, no effect on CSRT nor WP) which reflect competition between the effects related to its antiarrhythmic properties and those resulting from its direct vagolytic effect.

Electrophysiologic effects of cibenzoline in humans related to dose and plasma concentration

The electrophysiologic effects of a new antiarrhythmic agent, cibenzoline, were investigated in 25 patients with an average age of 62 years. The compound was administered intravenously, as a bolus given over 2 minutes, then as a slow infusion over 40 minutes. Each subject was randomly allocated to receive one of the following four doses: 1.55 mg/kg (six patients), 1.8 mg/kg (six patients), 2.2 mg/kg (six patients), or 2.6 mg/kg (seven patients). Plasma cibenzoline concentrations at these doses were 378 +/- 80,525 +/- 194, 618 +/- 72, and 731 +/- 196 ng/ml, respectively. Administration of 1.55 mg/kg cibenzoline significantly shortened the sinus cycle (60 msec on average; p less than 0.025) and increased intraatrial (+8 msec; p less than 0.05) and His-Purkinje conduction times (HV interval + 13 msec; p less than 0.001). At 1.80 mg/kg, prolongation occurred in the HV interval (+9 msec; p less than 0.02), the duration of the QRS complex (+20 msec; p greater than 0.05), and the QT interval (+18 msec; p less than 0.025). At the higher doses these changes became more marked (maximum increase: HV = +16 msec, p less than 0.001; QRS + 25 msec; p less than 0.001; QT + 26 msec, p less than 0.05), and additional effects on atrioventricular nodal conduction time (AH interval + 17 msec; p less than 0.05) and atrial (+20 msec; p less than 0.05) and ventricular (+10 msec; p greater than 0.05) effective refractory periods were observed. Prolongation of the QRS duration was the effect that correlated best with plasma cibenzoline levels (r = 0.47; p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

[Intravenous cibenzoline in the treatment of ventricular and supraventricular arrhythmias]

The efficacy of intravenous cibenzoline in the treatment of supraventricular and ventricular arrhythmias was demonstrated in a French trial of 212 patients including 40 in the acute phase of myocardial infarction. The minimal therapeutic plasma concentration was about 0.3 microgram/ml: this was obtained by a loading dose of 1 mg/kg relayed by a perfusion of 8 mg/kg/24 hours. The clinical tolerance was satisfactory in 96.2% of cases when the contra-indications were respected (severe cardiac failure, intraventricular conduction defects and non-paced 2nd and 3rd degree atrioventricular block). Local tolerance was excellent in all cases.

Electrophysiologic effects, antiarrhythmic activity and pharmacokinetics of cibenzoline studied with programmed stimulation of the heart in patients with supraventricular reentrant tachycardias

Cibenzoline, an imidazoline derivative is a new antiarrhythmic agent. Its electrophysiological effects and antiarrhythmic properties were studied with programmed electrical stimulation of the heart in 12 patients with recurrent episodes of reentrant supraventricular tachycardia; atrionodal (5 cases), circus movement tachycardia involving an accessory pathway (6 cases), intraatrial reentry (one case). Cibenzoline was infused intravenously at a dose of 1 mg kg-1 to 1.75 mg kg-1 during sustained episodes of tachycardia and over 9 to 15 min. Cibenzoline shortened the sinus cycle length, moderately increased the transnodal conduction time and markedly lengthened the HV interval. The refractory periods of the atrioventricular (A-V) node, the atrium and the ventricle did not change. The effects of cibenzoline on accessory pathways used in the anterograde direction were measurable in 4 cases. Complete blockade of the bypass was seen in every case. In the retrograde direction the refractory period of the bypass could be evaluated; in 5 patients it lengthened systematically. Infused intravenously during epidoses of tachycardia, the drug terminated the rhythm disorder in 9 out of 12 cases. Tachycardia could still be initiated in 8 patients after i.v. cibenzoline (2 out of 5 A-V nodal tachycardias, 6 out of 6 circus movement tachycardias). The distribution of the drug followed a bicompartment pharmacokinetic model. The plasma levels at the end of infusion ranged from 1.34 to 3.19 microgram ml-1. Cibenzoline, primarily has class I antiarrhythmic properties and its well-understood pharmacokinetics should be of help in tailoring the treatment to the individual needs of the patient.

Cardiac electrophysiological effects of cibenzoline by acute and chronic administration in the anesthetized dog

The electrophysiological effects of cibenzoline on the myocardium of the anesthetized dog were studied by the endocavitary catheter method. Plasma cibenzoline levels were measured throughout. The cibenzoline effects on the sinus rate were negligible. The corrected sinus recovery time was significantly prolonged only following chronic oral administration. Atrial refractory periods were significantly increased only at the fifth minute following acute intravenous administration and after chronic oral treatment. The intranodal conduction time (AH) and the refractory periods in atrio-ventricular node were slightly modified or not at all. On the other hand, intraventricular and His-Purkinje (HV) conduction times, ventricular refractory periods and QRS duration were strongly increased following acute or chronic administration. This would imply a principal effect on the rapid kinetics sodium entry current. Nevertheless, the very marked effect upon this current could, under the experimental conditions adopted, have masked a lesser action upon other membrane permeabilities, involved in other myocardial structures.