PubMed Health⌕ Search

Biomedical subjects

F Ferrari

Publications and source records attributed to F Ferrari.

At least 145 records · Page 8Linked to original sources
PubMed1991

Effects of B-HT 920 in the tail-suspension test.

The effect of B-HT 920 on mice subjected to the tail-suspension test (TST), a behavioural tool for gauging depression, was studied. During the test, all the animals had bouts of agitation interspersed with periods of immobility but B-HT 920-treated animals exhibited a differentiated behavioural pattern according to the dose employed: at doses selective for dopaminergic (DA) autoreceptor stimulation (50 and 100 micrograms/kg), the periods of immobility were unaffected, while at higher doses (0.5, 1, 2 and 3 mg/kg), which are also considered to be active on alpha 2-adrenoceptors, they were much shorter, as they are when known antidepressants are administered. Both clonidine (75 and 150 micrograms/kg) and yohimbine (1 and 5 mg/kg), alpha 2-adrenoceptor agonist and antagonist, respectively, increased immobility time, while N-n-propylnorapomorphine, a DA-agonist, at a dose (10 micrograms/kg) specific for DA autoreceptors, was completely ineffective. Since the behavioural effects of B-HT 920 vary according to the dosage employed, discussion centres on what receptors might conceivably underly these effects and on their preclinical relevance.

Adrenergic alpha-Agonists↗
PubMed1991

[Particulate contamination of amino acid solutions for parenteral use].

Three industrial batches of a 10% (w/v) amino acid solution have been checked for particulate contamination. The batches differed in preparative technology and/or type of additives. In particular, one batch was prepared under nitrogen, filled under vacuum and with the addition of sodium metabisulfite and cysteine. The other two batches were simply prepared under nitrogen and differed in the presence or not of cysteine and sodium metabisulfite. Accelerated stability tests were performed (40, 50, e 60 degrees C) and controls were effected both at room (25 degrees C) and refrigerator (6 degrees C) temperature. The results show that the preparation under nitrogen and the presence of cysteine result in an improved chemical stability and allow the particulate contamination level to be maintained within the limits of the Italian Pharmacopoeia. In particular, the batch prepared under nitrogen and filled under vacuum is characterized by a particulate contamination level which remains within the more restrictive limits of the British Pharmacopoeia for the entire period of the stability studies. Moreover, the particulate contamination control performed at 6 degrees C has proved to be a useful predictive tool with regards to batch quality evaluation.

Amino Acids↗
PubMed1991

A computer-aided simulation approach in the development of a prolonged release formulation.

Prolonged medication with diltiazem has proved advantageous in the treatment of coronary insufficiency and arterial hypertension. Consistently, a number of extended release formulations, based on different retardation mechanisms, have been proposed. In the present work two prolonged release oral formulations containing diltiazem, one intended for twice-a-day and one for once-a-day administration, were tested for in vitro behaviour; the in vitro release test had been opportunely validated using an in vitro-in vivo correlation approach. On the basis of in vitro release profiles, simulations were effected, using a computer program previously developed, in order to generate the plasma levels that could be expected on single dosing of the two formulations. The two formulations were then tested in vivo and the measured plasma profiles were compared with those predicted from in vitro data. For both formulations, a good agreement was found between the measured and the simulated plasma levels, thus demonstrating the usefulness of the simulation approach in the formulative development.

Adult↗
PubMed1991

[Glomerular filtration and renal volume in type II diabetes (non-insulin-dependent): study in normal and microalbuminuria patients].

In type 2 diabetes elevated glomerular filtration rate (GFR) and increased renal volume (RV), often accompanied to normo or microalbuminuria, were demonstrated. This condition is considered a pathogenetic factor for clinical nephropathy. As this topic is little studied in type 2 diabetes, we have investigated 73 type 2 diabetic patients (34 normo and 39 microalbuminuric), looking for a correlation between GFR, RV, hypertension, duration of diabetes and indexes of metabolic control. GFR was measured by a scintigraphy, after infusion of 99Tc-DTPA. Renal volume was determined by ultrasound scanning. Between the groups GFR and RV weren't different; elevated GFR was demonstrated in 3 patients; increased RV in 1 patient. In the hypertensive group GFR was lower than in normotensive group and in controls. Multivariate analysis in stepwise demonstrated that GFR presents a negative correlation to systolic blood pressure as in normo as in microalbuminuric patients. In the normotensive group GFR didn't correlate to the other variables. The present data suggest that in type 2 diabetes there is a little prevalence of glomerular hyperfiltration and increased renal volume and that hypertension plays a role on GFR of hypertensive diabetic patients.

Aged↗
PubMed1990

Qualitative changes of general movements in preterm infants with brain lesions.

The aims of the study were (1) to replicate previous quantitative studies of motor activity in low-risk and high-risk preterm infants and (2) to apply a new method of systematic analysis of the qualitative characteristics of general movements in these two groups of infants. Sequential one-hour videorecordings of the unstimulated infants in the incubator were made during the preterm period and then continued during the postterm period until about 20 weeks. The high-risk group consisted only of infants with signs of haemorrhage and/or leucomalacia in the repeated ultrasonograms of the brain. The neurological follow-up continued up to a minimum of one and a maximum of three years of corrected age. The quantification of the various motor patterns in 12 matched pairs of low-risk and high-risk preterm infants revealed a slight but significant (P = 0.05) excess of isolated arm movements in the low-risk cases during the activity phase. No other movement pattern differed significantly. The qualitative assessment of general movements during the preterm period resulted in all but one of the 14 low-risk cases having a normal quality of general movements. In the lesion-group (N = 29) all the infants had an abnormal quality during the preterm period. Eight cases later became neurologically normal although 1 of them had strabism. In addition, one infant was blind (ROP) and retarded and one other had mental retardation. Nineteen infants later developed cerebral palsy (two monoplegia of a leg, three hemiplegia, 5 diplegia and 9 quadriplegia). Strabism was present in 48.3% of the whole group of 29 cases. A semi-quantitative estimation of various aspects of the abnormal general movements made a typology of abnormal patterns possible. A graphic display of developmental trajectories of individual cases, depicting the course of abnormal aspects along the time axis, helps document the evolution of abnormal signs. Their course is a better predictor of the neurological outcome than the nature and localization of the lesion, detected by imaging techniques. The qualitative assessment of general movements from videorecordings is a reliable, quick, cheap and totally non-intrusive method in neonatology for the early detection of functional impairment of the nervous system.

Brain Diseases↗
PubMed1990

[Progression of cardiopathology in Friedreich ataxia: clinico-instrumental study].

Clinical, electrocardiographic and echocardiographic 5-year follow-up was performed in our institution on 61 patients with Friedreich's ataxia. Cardiac failure was evident in 5% of the patients, and was the most common cause of death. Cardiac arrhythmias, most commonly supraventricular in origin, usually occurred together with the onset of cardiac failure and in 1 case resulted in sudden death. ST-T abnormalities were present in 91% of the cases, and were independent from other clinical parameters. On the contrary, pseudonecrotic (5%) and right ventricular hypertrophy pattern were associated with a poor prognosis. Left ventricular hypertrophy was evident at the echocardiogram in 75% of cases and remained unchanged throughout the entire follow-up period. In 1 case left ventricular hypertrophy turned to dilative cardiomyopathy. Autopsy was performed in 2 out of 4 decreased patients and revealed massive interstitial fibrosis with cellular degeneration in the absence of coronary lesions.

Adolescent↗
PubMed1989

[Spleen autotransplant. Natural history and description of a case].

After considering the natural history of spleen auto-transplant, a clinical case followed up for seven months with instrumental (echography, scintigraphy) and humoral (Jolly bodies, Heinz bodies, reticulocytes, platelets, complement, immune globulin) examinations has been considered so as to verify "take" and function. One months after reimplantation the patient was again operated on for the onset of an intestinal occlusion due to adherences. On that occasion it was possible to control that the implant had taken. It is concluded that personally used parameters proved to be well correlated and that scintigraphy and echography are two complementary, effective techniques for monitoring auto-transplants.

Adult↗
PubMed1989

Results of a temporary balloon buckle in the treatment of 500 retinal detachments and a comparison with pneumatic retinopexy.

Five hundred detachments with a single break or a group of breaks close together were treated with parabulbar balloon and cryopexy in Tübingen between November 1980 and September 1986. Follow-up ranged from six to 91 months. Primary attachment was achieved in 466 eyes (93%). Twelve (2.4%) redetached after the balloon was removed. After a second operation, 490 eyes (98%) were attached and after a third, 493 (99%) were attached. The results with the extraocular balloon were compared with results of a similar group of detachments treated with an intraocular gas bubble. The primary attachment rate with the expanding gas operation was 91%; 11% of these eyes redetached. Although the final attachment rate was 99%, the complications after gas were much more frequent and of serious consequence.

Adolescent↗
PubMed1989

Does anxiety underly imidazole-induced behavioural effects in the rat?

Since behavioural symptoms (tremor, irritability, pilo-erection and shaking) induced by imidazole (IMID) in rats suggested an underlying modification of arousal and/or emotionality, further studies were performed in order to extend the range of behavioural influences of IMID. In the open-field test, IMID (37.5-300 mg/kg IP) inhibited crossing and rearing in a dose-dependent fashion, this effect being long lasting (about 3 h at 75 mg/kg). Yohimbine (YOH) (1, 5 and 10 mg/kg IP), described as anxiogenic and fear-inducing in animals and in man, when investigated in this same test, inhibited the activity of rats similarly to IMID. Since diazepam (0.5 and 1 mg/kg) but not clonidine (0.075 and 0.150 mg/kg IP) pretreatment reversed IMID- and YOH-induced hypomotility, the hypothesis that IMID effects in the open field might reflect an anxiety-like state was investigated by means of social interaction and x-maze, two tests considered highly specific for anxiety studies. The data obtained show that IMID depresses social interactions only at doses inhibiting motor activity; YOH, in our experimental conditions, produced a similar effect. In an elevated x-maze, with alternate open and closed arms, IMID (37.5 and 75 mg/kg) decreased the proportion of open-arm entries and the time spent in them, an effect prevented by diazepam pretreatment (1 mg/kg IP). Finally, mean arterial pressure (MAP) was assessed in anesthetized rats treated with IMID and YOH at doses equivalent as regards behavioural effects. MAP was increased by IMID whether IP or IV and decreased by YOH; moreover, YOH, as expected, antagonized clonidine-induced hypotension, while IMID was ineffective.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Posture and spontaneous motility in fullterm infants.

Posture and spontaneous motor patterns during the first days of life were studied in ten healthy fullterm infants by direct observation and videorecording. The aim of the study was to provide a description of motor and postural characteristics of normal newborns. The infants were recorded for 1 h on their first and fourth day of life, when unstimulated in an incubator. Incidence and duration of the different body postures and motor patterns were scored during the replay of the videorecordings. The preference for the fully flexed posture of arms and legs described in the literature could not be confirmed. There was a large intra- and inter-individual variability in the postural repertoire. No particular posture, characteristic for each behavioural state, existed. Similar postures rarely occurred in the same infant on the first and fourth day. Extended postures more often occurred on the fourth day. Spontaneous motility consisted of several distinct movement patterns, the occurrence of which in states 1 and 2 was computed for day 1 and day 4. Motor patterns were differently related to the states. No differences were noted in the motor activity between the first and fourth days. Large inter-individual differences, but an intra-individual consistency, were found in the rates of specific motor patterns: infants who showed a low or high rate of particular movements on day 1 maintained the same characteristic on day 4. There was no overall low or high motor activity.

Female↗
PubMed1989

Rheological properties and diffusion dissolution behaviour of hydrophilic polymers.

In a mathematical model that has been recently proposed to predict drug release from polyvinyl alcohol matrices, polymer dissolution is described as a chain disentanglement process and characterized by a threshold polymer concentration. In present work viscosity measurements were employed for defining the characteristic entanglement concentration of polymer solutions. The viscosity of aqueous polymer solutions of differing concentrations was measured over a wide range of shear rate using a rotational viscometer. The flow curves were fitted according to an asymptotic model and from the best fit equation the relevant viscosity parameters were obtained. The relationships between polymer concentration and viscosity parameters were also examined. The critical concentration at which an abrupt change of viscosity properties occurred was identified and related to the molecular chain disentanglement conditions.

Chemical Phenomena↗
PubMed1989

Swelling-restricted minimatrices for controlled release of drugs. Preliminary in-vivo studies.

A preliminary in-vivo study was performed on a new modified release system which contained diltiazem hydrochloride. The system consisted of swellable minimatrices that were coated with an acrylic polymeric film. The film thickness, because of its pH-dependent solubility, might represent a critical variable with regard to in-vivo release. In order to evaluate the influence of such a variable on in-vivo behaviour, two minimatrices formulations with differing film thickness were tested versus a commercial tablet. The in-vivo study, which was based on a balanced incomplete block design, involved six volunteers in two sequences. The drug was quantified in plasma by an HPLC method. Computation and statistical analysis of pharmacokinetic parameters were performed by means of SIPHARR package (Simed, F). The results show that the approach of film coating, in order to modify the release rate from minimatrices, is feasible, but it must be improved; in particular the results point to the necessity of reducing the film susceptibility to pH changes.

Adult↗
PubMed1989

[Differential diagnostic problems in the echographic study of adrenal metastases].

The sonographic detection of adrenal masses in patients with neoplasms, especially neoplasms of the lung, can be related to the presence of both metastases and adenomas. In order to assess the benign/malignant nature of such lesions, the adrenal glands of 43 patients with neoplasms (36 of them lung cancers) were studied with sonography (US) and fine needle aspiration biopsy (FNAB): in all, 58 masses were seen (28 monolateral and 15 bilateral). Six lesions (13%) presented with cytological features of benignancy, and on US they appeared as hypoechoic (as compared to the liver), round masses, with regular margins, ranging in size from 1.2 cm to 3.4 cm (average: 2.6 cm). In the remaining 34 patients (80%), cellular material with features of malignancy was obtained with FNAB. The US appearance of these metastases was heterogeneous, with the same echogenicity as the liver, and average size greater than 3 cm. On the basis of our data, the limit of 3 cm (if we consider the average dimension), corresponds to the threshold of benignancy, as well as the monolateral and hypoechoic appearance of the lesion. To sum up, the use of FNAB should be limited to those lesions which present with typical adenomatous features and for borderline lesions, while the diagnosis of metastasis is sufficiently accurate (p less than 0.001) in case of bilateral or isoechoic lesions greater than 3 cm.

Adenoma↗
PubMed1989

Antinociceptive properties of lysozyme fragments.

The in vitro digestion of hen egg white lysozyme with artificial gastric juice gave a complex mixture of peptides, from which a peptide corresponding to the aminoacid sequence 39-53 was isolated. Its further hydrolysis with artificial enteric juice gave two smaller fragments having the aminoacid sequence 39-45 and 46-53 respectively. These products, like lysozyme, showed antinociceptive activity in rats against foot hyperalgesia induced by a subplantar injection of brewer's yeast.

Analgesics↗
PubMed1988

Effect of isolation on dopaminergic agonist-induced penile erections and stretching and yawning in male rats.

Adult male rats reared in social isolation for 28 +/- 2 days were compared with animals housed in groups and pairs for frequency of penile erection (PE) and stretching and yawning (SY) elicited by dopaminergic (DA) autoreceptorial doses of B-HT 920 and n-N-propylnorapomorphine (NPA). PE and SY were consistently lower in the isolated group with respect to the other two groups, which did not differ significantly. The present experiments show the importance of housing conditions in modulating behavioural responses to DA agonists, a result that was confirmed when adult male rats, isolated or paired immediately after weaning until the day of tests (56 +/- 2 days), were treated with B-HT 920. In this case, however, not only isolated but also paired rats differed from grouped rats of the same age in their response to B-HT 920.

Animals↗