Search PubMed⌕ Search

Biomedical subjects

R Raffaele

Publications and source records attributed to R Raffaele.

At least 37 records · Page 2Linked to original sources

Dopaminergic hypothesis for retarded depression: a symptom profile for predicting therapeutical responses.

We assessed the therapeutical efficacy of various antidepressants (amineptine, minaprine and clomipramine) in patients affected by retarded depression. All patients exhibited symptoms of retardation, including hypokinesia, anergia, reduction of speech, increased salivation, hypersomnia, Parinaud's syndrome, reduced sexual activity, slowness, hypomimia, orthostatic hypotension, dysphagia and drowsiness. Antidepressant drugs were administered for a 6-week period in a randomized double-blind vs placebo design. The rank order of clinical effectiveness (amineptine much greater than minaprine greater than clomipramine greater than placebo) paralleled the specificity of antidepressants as dopaminomimetic agents. These results support the view that a reduced dopaminergic transmission contributes to the pathophysiology of retarded depression.

Adult↗

[Anatomic connections between homotopic transplant of fetal cortical tissue and optic thalamus in adult rats].

The present research was planned to study the possibility to reconstruct a damaged neural circuitry by replacing the injured neurons with homotopic fetal cells. In adult rats the motor cortex was injured with intracortical injection of kainic acid solution. After a delay of 10-14 days, a block of cerebral cortex of fetal rats (E17) was transplanted in the cavity produced by the kainic acid in the motor cortex. After 2-3 months, WGA-HRP solution was injected in the thalamus of the host and both anterogradely labeled fiber terminals and retrogradely labeled somata cells were researched in the transplanted cortex. The results showed that: 1) the host thalamus projects to the transplanted cortex with less density compared to the host cortex surrounding the transplant; 2) the thalamic projection to the transplant is not topographically organized whereas the projection to the host cortex is; 3) the transplant was virtually void of a significant projection to the thalamus of the host. In conclusion, the results offer direct evidence that the reconstruction of an injured thalamocortical circuitry of adult rat is not possible by transplanting homotopic fetal neurons.

Animals↗

Memory deficits of aged male rats can be improved by pyrimidine nucleosides and n-acetyl-glutamine.

The pyrimidine nucleosides uridine (URI) and cytidine (CYT), alone or associated with n-acetyl-glutamine (NAG), were injected acutely or subchronically to aged (26 months old) male rats of the Sprague-Dawley strain. Learning and memory abilities of the animals were studied with tests of avoidance behavior. The acquisition of active avoidance behavior was studied with the shuttle-box test. A step-through type of passive avoidance task was used to examine the retention of passive avoidance responses. The acquisition of the active avoidance behavior and the retention of the passive avoidance response were reduced in aged animals as compared with those of young animals. Neither the acute treatment of old rats with URI and CYT alone nor that associated with NAG exerted any effect on the behavioral tests. In contrast, the subchronic treatment with URI and CYT was followed by a facilitation of acquisition of active avoidance behavior in the shuttle box and of retention of passive avoidance responses in the dark box. A more potent effect on the acquisition of the shuttle-box behavior and on the retention of passive avoidance reaction was found in animals treated subchronically with the pyrimidine nucleosides associated with NAG. These effects may be related to the role of pyrimidines in the synthesis of ribonucleic acid, which is indispensable for learning and memory processes.

Aging↗

[Modification of the blink reflex in hemidystonia].

With the aim of evaluating the excitability of the brain stem reflex centers, we studied the side-to-side differences in the EMG activity of the early and late components of the blink reflex, in subjects with unilateral dystonia without demonstrable brain lesions. We observed that both early and late responses of direct blink reflex were significantly higher in the affected side than in the contralateral one.

Blinking↗

Effect of acetyl-L-carnitine on geriatric patients suffering from dysthymic disorders.

Sixty senile subjects (60-80 years old) with dysthymic disturbances as defined by DSM III (Cat. 390.40) were randomized into two homogeneous groups, one of which was given acetyl-L-carnitine (3 g/day per os) while the other received a placebo. After a washout phase of one week, each patient was evaluated by scoring on the Hamilton Rating Scale for Depression and the Beck Depression Inventory, as well as the Sandoz Clinical Assessment-Geriatric. These tests were administered at the beginning of the trial, prior to drug administration, and repeated during the treatment phase after 30 and 60 days. The results showed that treatment with acetyl-L-carnitine induced a significant reduction, as compared to the placebo (p less than 0.002), in the severity of depressive symptoms and also a significant improvement (p less than 0.0027) in the items measuring the quality of life.

Acetylcarnitine↗

Unilateral enhancement of early and late blink reflex components in hemidystonia.

The side-to-side differences in the EMG activity of the early and late components of blink reflex, regarded as revealing the state of excitability of the brain stem reflex centers, have been analyzed in patients with unilateral dystonia without demonstrable brain lesions. It has been observed that both early and late responses of direct blink reflex were higher on the side affected by hemidystonia than on the contralateral one, while the latency values were in the normal range. Possibility that an abnormal output from the striatum towards the brainstem structures involved in blink reflex appears on the affected side of hemidystonic patients is discussed.

Adult↗

Prolactin as a protective factor in stress-induced biological changes.

The adenohypophyseal hormone prolactin (PRL) is released during stress of physical and psychological nature. In animals, this hormone facilitates adaptive behavior, induces analgesia, and enhances grooming behavior. It also reduces corticosterone secretion and the incidence of gastric ulcers induced by physical stress. It is possible that PRL plays a protective role against stress-induced biological modifications in animals.

Animals↗

Projections from the intracerebellar nuclei to the ventral midbrain tegmentum in the rat.

The present study was undertaken to provide anatomical evidence, in the rat, for a direct projection from the cerebellum towards structures, other than the red nucleus, which belong to the ventral midbrain tegmentum, by using the retrograde as well as the anterograde horseradish peroxidase transport method. Following unilateral injection in the ventral midbrain tegmentum of horseradish peroxidase, free or conjugated to wheat germ agglutinin, sparing the red nucleus, retrogradely labeled neurons were found in the contralateral cerebellar lateral nucleus and, at lower density, in the interpositus nucleus. No labeled neurons were found in the fastigial nucleus of either side. Anterogradely labeled axons from lectin coupled horseradish peroxidase injection sites in the lateral and interpositus nuclei reached the contralateral ventral midbrain tegmentum. Terminal labeling was observed in the entire red nucleus as well as in the lateral division of the ventral tegmental area of Tsai, in the dorsal region of the substantia nigra pars compacta, and in the medial part of the retrorubral field. No terminal labeling was found in the caudal linear nucleus, interfascicular nucleus, peripeduncular nucleus, rostral linear nucleus of the raphe, substantia nigra pars lateralis and the substantia nigra pars reticulata. Terminal labeling was also not observed in the ventral midbrain tegmentum following horseradish peroxidase injection in lateral and interpositus nuclei of rats pretreated with kainic acid. In conclusion, it is noteworthy that, besides the red nucleus, the sole structures of ventral midbrain tegmentum receiving cerebellar efferents are those with a higher density of dopaminergic cells.

Animals↗

Influences of dopaminergic systems on the blink reflex.

The effect of the anti-dopaminergic drug haloperidol (6 mg/day i.m. for 2 days) on the blink reflex elicited by electric stimulation of supraorbital nerves was investigated in 12 adult volunteers. A significant increase in amplitude of the early component (R1) of the reflex was observed. This increase disappeared within 5 days of stopping the drug. Possible neural systems which might be involved in these effects are considered.

Adult↗

IgG1,3 and 4 oligoclonal bands in multiple sclerosis and other neurological diseases.

Cerebrospinal fluid (CSF) samples from 10 patients with Multiple Sclerosis (MS) and 7 with other neurological diseases (OND) were studied in order to detect oligoclonal restriction of IgG subclasses 1,3 and 4. Agarose isoelectric focusing (AGA-IEF) followed by Western capillary blotting and immunoperoxidase staining with specific monoclonal antibodies were used. All MS samples showed oligoclonal IgG1 and 6 of them also had IgG3 or IgG4 bands. In the OND group only patients with subacute sclerosing panencephalitis (SSPE) and Guillain-Barré disease (GBD) showed CSF oligoclonal patterns for IgG subclasses. Our results demonstrate that in MS CSF other IgG subclasses beside IgG1 may display an oligoclonal pattern. The finding of more than one subclass in the same band indicates a microheterogeneous composition of these oligoclonal bands.

Adolescent↗

Influences on blink reflex induced by IA afferents in human subjects.

The effects induced by IA volleys, evoked with H reflex, on the blink reflex elicited upon electric activation of supraorbital nerves were investigated in 14 healthy subjects as well as in 4 cerebrovascular patients. In both groups a significant increase in amplitude of the early component (R1) of ipsilateral blink reflex has been observed. A brief discussion of possible neural systems which might be involved in these effects is given.

Blinking↗

[Effects of systemic administration of kainic acid on GABAergic and glutaminergic transmission in various areas of the brain].

In the present study that Authors have investigated the effects of systemic injection of kainic acid on aminoacidergic transmission of different rat brain regions. Kainic acid has been used to produce an experimental model of limbic epilepsy characterized by two different phases (KA1 and KA2). Results obtained show a significant decrease of glutamic and aspartic acids (excitatory aminoacids) and glicine and taurine (inhibitory aminoacids) in both phases at hippocampal level. On the contrary GABA concentration seems to be increased.

Animals↗

Calciotropic hormones as possible modulators of rat extrapyramidal motor system.

In the present study the Authors have investigated the effects of chronic treatment with calcitonin and parathyroid hormone on rat extrapyramidal motor system. Although it seems that calcitonin and parathyroid hormone may act as a neuromodulators at extrapyramidal level by influencing, directly or indirectly, nigro-striatal dopaminergic transmission, the role played by calcium metabolism at peripheral level, is not clear. In order to put light on this matter, different groups of animals were treated with calciotropic hormones plus EDTA, which is a drug that blocks Ca2+ ions, or EDTA alone. The results obtained don't show any change either in nigral GAD activity or apomorphine induced hyperactivity in EDTA injected animals. Furthermore, EDTA doesn't seem to modify the effects of both PTH and ct, as shown by results obtained in animals treated with ct or PTH plus EDTA.

Animals↗

[Effects of zinc sulfate on limbic motor epilepsy induced by kainic acid].

In the present study the Authors have investigated the effects of chronic pretreatment with injections of Zn++ sulphate solution on kainic acid induced epilepsy, to verify wether or not Zn++ is able to change the epileptiform pattern induced by kainic acid infection. Results obtained show that Zn++ do not produce any significant change in the experimental parameters by us study.

Animals↗