Biomedical subjects

M Maffini

Publications and source records attributed to M Maffini.

At least 19 recordsLinked to original sources

PubMed2006

Experimental design optimization for the ICP-AES determination of Li, Na, K, Al, Fe, Mn and Zn in human serum.

A chemometric approach based on experimental design and desirability functions was used to develop and validated a method for the determination of some metals of biological concern by a fast sequential ICP-AES. The elements considered are Al, Fe, Mn, Zn, Li, Na and K. The experimental design was used to investigate the effects of three instrumental most crucial parameters, such as sheath gas flow rate, pump speed and auxiliary gas flow rate. In order to improve the multielemental analysis speed, although a sequential instrument allows the use of a separate parameter set for each wavelength, regression models and desirability functions were applied to find the experimental conditions providing the highest global sensitivity. Validation was performed in terms of limits of detection (LOD), limits of quantitation (LOQ), linearity, precision and recovery. By using the 167.02 nm wavelength, aluminium LOD was 0.5 microg L(-1) while the highest LOD was found for K (65 microg L(-1)). A linear range of at least three orders of magnitude was statistically demonstrated for each element. Precision was evaluated by testing two concentration levels, and good results in terms of intra-day repeatability were obtained, with R.S.D. values lower than 4.1% at the lowest concentration level. Lacking a suitable certified reference material, trueness was estimated using the recovery rate on fortified samples. The validated method was then used in the quantification of the elements considered in a serum sample.

Aluminum↗

PubMed2003

Use of experimental design for optimisation of the cold plasma ICP-MS determination of lithium, aluminum and iron in soft drinks and alcoholic beverages.

A sensitive method for the simultaneous determination of (7)Li, (27)Al and (56)Fe by cold plasma ICP-MS was developed and validated. Experimental design was used to investigate the effects of torch position, torch power, lens 2 voltage, and coolant flow. Regression models and desirability functions were applied to find the experimental conditions providing the highest global sensitivity in a multi-elemental analysis. Validation was performed in terms of limits of detection (LOD), limits of quantitation (LOQ), linearity and precision. LODs were 1.4 and 159 ng L(-1) for (7)Li and (56)Fe, respectively; the highest LOD found being that for (27)Al (425 ng L(-1)). Linear ranges of 5 orders of magnitude for Li and 3 orders for Fe were statistically verified for each compound. Precision was evaluated by testing two concentration levels, and good results in terms of both intra-day repeatability and intermediate precision were obtained. RSD values lower than 4.8% at the lowest concentration level were calculated for intra-day repeatability. Commercially available soft drinks and alcoholic beverages contained in different packaging materials (TetraPack, polyethylene terephthalate (PET), commercial cans and glass) were analysed, and all the analytes were detected and quantitated.

Alcoholic Beverages↗

PubMed1998

TAR-RNA binding by HIV-1 Tat protein is selectively inhibited by its L-enantiomer.

An oligoribonucleotide, corresponding to the Tat-interactive top half of the HIV-1 TAR RNA stem-loop, was synthesized in both the natural D- and the enantiomeric L-configurations. The affinity of Tat for the two RNAs, assessed by competition binding experiments, was found to be identical and is reduced 10-fold for both, upon replacement of the critical bulge residue U23 with cytidine. It is suggested that this interaction of the flexible Tat protein depends strongly upon the tertiary structure of a binding pocket within TAR, but not upon its handedness, and may be described by a 'hand-in-mitten' model.

Binding, Competitive↗

PubMed1997

Leukocyte infiltration and collagenolysis in cervical tissue from intrapartum sheep.

Sheep uterine cervices and cervical mucus were heavily infiltrated by neutrophils during labour, whereas samples of cervices obtained from non-pregnant controls had no infiltrate. The neutrophilic infiltrate of the sheep uterine cervix at term was not homogeneously distributed throughout the organ: luminal mucus contained more neutrophils than tissues which, in turn, displayed a differential distribution, the superficial subepithelial layer being more heavily infiltrated than the deeper submucous layers. A widespread collagenolysis was observed in the sheep uterine cervix at term. The homogeneous morphological aspect of degradation of collagen fibres throughout the whole cervical stroma contrasted with the above-mentioned differential distribution of neutrophils. On the basis of previous reports showing that collagenolysis follows the leukocytic invasion of human and rat cervices at term, a possible role for the neutrophilic infiltrate of the sheep uterine cervix is discussed.

Animals↗

PubMed1995

Vigabatrin edema.

Explore the source record for details and available documents.

Anticonvulsants↗

PubMed1994

Long-term observations on the clinical use of lamotrigine as add-on drug in patients with epilepsy.

We report open-label clinical observations of additional lamotrigine (LTG) in 16 adult patients with refractory epilepsy, aimed to assess the long-term efficacy and safety of LTG in clinical use. LTG was added to the current antiepileptic drug (AED) regimen at a daily dosage of 200-400 mg depending on the concomitant treatment. Ten patients completed one year's treatment and were followed up to an overall exposure ranging 15-38 months. Six patients (38% of the initial group) had a reduction of seizure frequency greater than 50% of pre-treatment baseline after one year; the further follow-up indicated some efficacy decline, since the percentage of improved patients dropped to 19% after 2 years and 13% after 3 years. The dropouts during the first year were due to seizure breakthrough (two patients), Steven-Johnson-like syndrome (one patient) and reasons unrelated to treatment (three patients); in one patient LTG treatment was stopped due to macrocytic anemia after 23 months. Other reported adverse events were dizziness, mild ataxia, diplopia and localized purpura. No other hematological or biochemical changes were noted. LTG was not associated with any significant changes in plasma concentrations of concomitant AEDs. These findings confirm the moderate efficacy and low toxicity of long-term LTG in severe epilepsy.

Adolescent↗

PubMed1993

Large scale, liquid phase synthesis of oligonucleotides by the phosphoramidite approach.

A new method for the liquid phase synthesis of oligonucleotides is described which makes use of polyethylene glycol (PEG) as soluble support and phosphoramidite derivatives as synthons. The new synthetic protocol was applied to a quite large scale production (about 100 mumoles) of such compounds up to the 20mer level. This solution method, called HELP High Efficiency Liquid Phase) Plus, appears effective in terms of speed and coupling yield and can be evaluated for the production of large amount of oligonucleotides.

Chromatography, High Pressure Liquid↗

PubMed1993

Vigabatrin in chronic epilepsy: a 7-year follow-up study of responder patients.

Data on efficacy and safety of vigabatrin over very protracted treatment periods are still limited. This study reports the follow up of 23 responder epileptic patients who continued vigabatrin treatment after completion of the first year, to an overall long-term exposure ranging 21-84 months (median 60; mean 58.0 +/- 24.0 sd). The seizure frequency during the follow up was compared with that at the end of the first year on vigabatrin. The rates of patients who gained a further improvement and those who deteriorated were almost identical, ranging 33-45% and 33-46% respectively at individual time points. At the trial endpoint, nine patients (39%) were improved, five (22%) were unchanged and nine (39%) showed some deterioration. All patients still had a 14-100% decrease of seizure frequency as compared with pretreatment baseline. Two patients discontinued vigabatrin for occasional reasons. No patient experienced new adverse events during the follow up after the first year on vigabatrin. No significant effects were noted on any of the routine hematologic or metabolic screening assessments. Although reduction of concomitant treatment was rarely possible, the overall number of associated antiepileptic drugs dropped from 42 at entry to 40 at the trial endpoint. These findings indicate that vigabatrin retains its efficacy and safety in responder patients for periods up to 7 years.

Adolescent↗

PubMed1992

MRI findings in epileptic patients on vigabatrin for more than 5 years.

Although vigabatrin is a promising new antiepileptic drug, its safety has been challenged by the report of dose-dependent central nervous system myelin vacuolation in some preclinical animal studies. Since it has been shown that vacuolation is associated with specific magnetic resonance imaging (MRI) findings in rats and dogs, MRI of the brain was performed in 11 patients with complex partial seizures who had been receiving vigabatrin for 64-78 months (mean 74.0 +/- 5.0 sd) as additional treatment for epilepsy, with a cumulative exposure ranging 4200 to 9360 g. In no case did MRI show white matter changes similar to the pathological findings of microvacuolation observed in animals. These results would appear to confirm that current doses of vigabatrin do not cause myelin vacuolation in humans, even for treatment periods of longer than 5 years.

Adult↗

PubMed1988

Preliminary note on the effect of denzimol in partial epilepsy.

The antiepileptic activity of the imidazole derivative denzimol has been evaluated in 10 patients with poorly controlled partial epilepsy by adding on the drug to the current therapy, in an open preliminary trial. A sustained drop in seizure frequency greater than 50% occurred in 5 patients. Although denzimol increased blood concentrations of carbamazepine, correlation analysis indicated that the improvement was more likely due to intrinsic properties of denzimol. No severe side effects were reported, although several patients experienced nausea and vomiting, which caused 2 patients to drop out.

Adult↗

PubMed1988

Phosphatidylserine increases in vivo the synaptosomal uptake of exogenous GABA in rats.

A sonicated liposome suspension of gamma-aminobutyric acid (GABA) and phosphatidylserine (liposome-entrapped GABA), intraperitoneally administered in rats, inhibited EEG epileptic activity induced by penicillin, whereas GABA did not. A significant increase (20.4%) in brain radioactivity accumulation occurred at 5 min after i.p. administration of [14C]GABA associated with phosphatidylserine in comparison with the administration of [14C]GABA; such an increase persisted after 20 min. However, the accumulation of radioactivity into brain synaptosomes demonstrated a 24.1% increase at 5 min and subsequently showed a 43.3% increase at 20 min after injection of liposome-entrapped GABA. The above findings suggest that phosphatidylserine stimulates exogenous GABA uptake into brain GABAergic nerve terminals.

Animals↗

PubMed1988

Preliminary observations on the activity of progabide, administered as monotherapy in complex partial seizures.

Progabide (PGB), a gamma-amino-butyric acid receptor agonist, was administered, according to an open-label long-term design, to 40 adult patients suffering from complex partial seizures, with or without secondary generalization, whose response to carbamazepine (CBZ) monotherapy was unsatisfactory. A reference-baseline period of two months with carbamazepine monotherapy was followed by a two-month "add-on" period where increasing doses of progabide were added without modifying the CBZ regimen; then CBZ was withdrawn over 15-60 days and patients were followed up to 12 months' progabide treatment. Twenty-seven patients completed the trial but 12 of them had to be returned to CBZ + PGB bitherapy due to an increase of seizures following CBZ withdrawal. A definite therapeutic effect could be observed in nine patients on PGB monotherapy and in six patients on CBZ + PGB bitherapy. Side-effects of clinical relevance occurred in three cases and were represented by remarkable anxiety in two patients and a rise in serum glutamic oxalo-acetic acid and pyruvic transaminases with clinical symptoms of liver dysfunction in one, with rapid recovery following progabide discontinuation. In conclusion, progabide was effective against complex partial seizures in about 40% of patients not responding satisfactorily to available antiepileptic drugs. Although the withdrawal of previous antiepileptic drugs was not possible in all patients, progabide monotherapy was sometimes more effective than CBZ monotherapy, and several patients in whom bitherapy had to be restored benefited from the association of progabide.

Adolescent↗

PubMed1987

Carbamazepine and cardiac conduction disturbances.

Carbamazepine-induced cardiac conduction disturbance is reported in 2 patients suffering from epilepsy. The cardiac defects disappeared in both patients after carbamazepine was discontinued, and reappeared in 1 patient after treatment was resumed.

Bradycardia↗

PubMed1987

Preliminary evaluation of the effect of GABA and phosphatidylserine in epileptic patients.

The effect of the combined administration of gamma-aminobutyric acid (GABA) and phosphatidylserine was evaluated in a pilot study of 42 patients with drug-resistant epilepsy. The group included patients with complex partial seizures, simple partial seizures and absence seizures. Patients with complex partial seizures and simple partial seizures showed no significant improvement; on the other hand, there was a remarkable decrease in absence seizures, linearly related to the dose of GABA and phosphatidylserine. Side effects occurred in 9 patients and were usually mild.

Adolescent↗

PubMed1982

Liposome-entrapped GABA modifies behavioral and electrographic changes of penicillin-induced epileptic activity.

We studied Sprague-Dawley rats with spike activity and myoclonus after intraperitoneal injections of penicillin. Twenty minutes after penicillin injection, one group received a random crossover treatment by intraperitoneal GABA (gamma-aminobutyric acid) or liposome-entrapped GABA (LEG) or phosphatidylserine alone. The other group received GABA, LEG, or phosphatidylserine followed 15 minutes later by the injection of penicillin. LEG decreased or prevented the epileptic activity, whereas no significant changes were seen with either GABA or phosphatidylserine given alone. LEG may enhance penetration of GABA across the blood-brain barrier because of the carrier action of the liposomes.

Animals↗

PubMed1982

[HLA and Huntington chorea].

Twenty-three patients with documented Huntington's Chorea were typed for 54 HLA antigens belonging to A, B and C loci. The control group was constituted by 124 healthy subjects of the same ethnic background. Patients and controls were typed with the same antisera. In this study no significant differences in the distribution of HLA antigens between the two groups were found. These data indicate that Huntington's Chorea is not associated with any of HLA antigens serologically determined. However, these findings do not exclude the possibility that other genes, whether or not related to MHC, could be responsible of the family inheritance of the disease.

Adult↗

PubMed1981

[Schizophrenia and HLA antigens].

38 schizophrenic patients (21 hebephrenics and 17 paranoids) and 124 healthy subjects were matched for HLA antigens. HLA typing was determined by the microdroplet lymphocyte toxicity method developed by Terasaki of UCLA. In order to detect 47 HLA antigens as many as 118 antisera were used. No significant differences in HLA typing were found between the two groups. However, the separate evaluation of HLA antigens of hebephrenic schizophrenics did not give any statistical significance, as well. The authors discuss these findings in the light of previous studies on the topic.

Adolescent↗

PubMed1980

Alcohol withdrawal syndrome: treatment with trazodone.

Central monoaminergic pathways dysfunction has been shown in the alcohol withdrawal syndrome of experimental animals: noradrenergic hyperfunction and serotonin transmission impairment is suggested by many studies. Trazodone is a new psychotropic drug which has a marked norepinephrine receptor blocking power; moreover, it inhibits serotonin reuptake and was fully effective in the treatment of man's withdrawal syndrome (17 alcoholic inpatients). The good therapeutical results make it conceivable that monoaminergic pathways dysfunction has an important pathophysiological role in the alcohol withdrawal syndrome of man also.

Adult↗