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Biomedical subjects

C Menini

Publications and source records attributed to C Menini.

At least 73 records · Page 4Linked to original sources

Effects of opiate-like peptides, morphine, and naloxone in the photosensitive baboon, Papio papio.

The effects of intracerebroventricular (i.c.v.) or systemic injections of Met- or Leu-enkephalin, beta-endorphin, FK 33.824 (D-Ala2, MePhe4, Met(O5)-ol-enkephalin) and of morphine and naloxone have been studied in baboons, Papio papio, which spontaneously show photically induced epileptic responses. Animals were chronically implanted with epidural or deep recording electrodes and a cannula in one lateral ventricle, and tested whilst seated in a primate chair. In some animals the natural syndrome was enhanced by the prior administration of DL-allylglycine, 100--200 mg/kg, i.v. Met- or Leu-enkephalin, 1--10 mg, i.c.v., did not lead to any manifest focal or generalized seizure discharges. Nor did it lead to any consistent enhancement or reduction of photically induced myoclonic responses (as tested 5--10 min after injection). beta-Endorphin, 0.1--0.5 mg, i.c.v., did not enhance or impair photically induced myoclonic responses. FK 33.824, 0.1--0.5 mg, i.c.v., depressed respiration and slowed EEG background rhythms for 9--15 h. This was associated with a loss of myoclonic responses to photic stimulation. These effects were reversed for 20--40 min following the injection of naloxone, 1 mg/kg i.m. A depression of respiration and a slowing of EEG rhythms was seen beginning 5--20 min after FK 33.824, 2 or 4 mg/kg, i.v. The higher dose also abolished photically induced myoclonic responses. Naloxone, 1 mg/kg, definitively reversed these effects. Morphine, 5--10 mg i.c.v., tended to increase the latency to onset of generalized myoclonus during photic stimulation. Myoclonic responses were delayed or diminished after morphine, 5 mg/kg, i.m. Naloxone, 1--2 mg/kg i.m., reversed this effect. Naloxone, 0.2--5.0 mg/kg i.m., alone, did not significantly modify photically induced myoclonus, either in animals of low or high initial responsiveness, or in those pretreated with allylglycine.

Animals↗

Proconvulsant, convulsant and other actions of the D- and L-stereoisomers of allylglycine in the photosensitive baboon, Papio papio.

The effects of the intravenous or intracerebroventricular injection of the stereoisomers, and the racemic mixture, of allylglycine (2-amino-pent-4-enoic acid) have been studied in baboons, Papio papio, with photosensitive epilepsy. Enhancement of the natural syndrome of photosensitivy epilepsy is seen 1-12 h (maximally at 3-8 h) after L-allyglycine, 100 mg/kg, intravenously, or D,L-allyglycine, 200 mg/kg, intravenously. Such enhancement is seen with a slower onset, and to a lesser, and more variable, extent after D-allyglycine, 500-750 mg/kg, intravenously. Brief focal or generalised seizures occurred (in the absence of intermittent photic stimulation) after L-allyglycine, 150-200 mg/kg, intravenously. This effect is similar to that previously observed after D,L-allyglycine, 300-400 mg/kg. D-Allyglycine, 780 mg/kg, intravenously produced episodes of vertical nystagmus with increased extensor motor tone, but no 'spontaneous' seizures. Intracerebroventricular injection of L-allylglycine, D-allyglycine or D,L-allyglycine, 100 mg in 1 ml saline, did not modify the natural syndrome of photosensitive epilepsy. D-Allylglycine, or D,L-allyglycine, 100 mg intracerebroventricularly, after 1-2 h gave rise to a syndrome with vomiting, sustained vertical nystagmus, and intermittent extensor spasms. The results are interpreted in terms of regional differences in the metabolism of the two isomers to active compounds that can inhibit glutamic acid decarboxylase. D-Allylglycine is active only at the brain stem and cerebellum because D-amino acid oxidase is largely confined to these brain areas.

Allylglycine↗

[The significance of cryoglobulins and cryohemagglutinins. Immunological and clinical study of 39 cases].

In about 5 years of clinical and immunological research, 39 cases of cryoplasmopathies (5 with cryoglobulinaemia and 34 with cryohaemoagglutinaemia) were identified on the basis of immunological typing studies (immunoelectrophoresis, immunodiffusion, identification and isolation of cryoantibodies, cryocrit, titration, identificcation of antibody specificity). Discussion and physiopathological interpretation of possibly associated cases and diseases are conducted on the basis of personal immunological data and the most recent literature on matters of clinical immunohaematology.

Agranulocytosis↗

Myoclonus developing after vermisectomy in photosensitive Papio papio.

Two vermisectomized photosensitive baboons exhibited two different types of myoclonus, one induced by intermittent light stimulation (ILS) and the other occuring "spontaneously". The characteristics of these two types of myoclonus are described from a clinical and from an ECoG point of view. Myoclonus induced by ILS (ML) started at the eyelids and secondarily invaded the face and body; it was always preceded by frontorolandic spike-waves or polyspike-waves. The "spontaneous" myoclonus which followed vermisectomy (MV) was "massive", but involved firstly the trunk and secondarily the face and limbs; no ECoG paraoxysm accompanied this myoclonus, but we observed a parietal evoked potential of small amplitude, 10--15 msec after its onset. If MLs can be considered as consequences of the fronto-rolandic paroxysmal discharges, MVs seem to originate in the brain stem but appear similar to action myoclonus. This experimental situation showing two types of myoclonus resembles human hereditary degenerative syndromes (dyssynergic cerebellar myoclonus, progressive myoclonic epilepsy), without being exactly comparable. The conditions in which MVs were seen and their modifications during sleep and by different drugs are described. The relationships between MVs and MLs and myoclonic epilepsy are discussed.

Animals↗

Population genetics in the province of Ferrara. I. Genetic distances and geographic distances.

The ABO and Rh systems of the population in 26 residential units in the province of Ferrara were studied to detect the effect of genetic drift on the differentiation of gene frequencies. Results obtained from principal components analysis and dendrograms were similar. A significant correlation between genetic and geographic distance was found. It was therefore hypothesized that in the area of Ferrara children born to parents originating from different communes were heterozygous at more loci than children born to parents originating from the same commune. It was also thought that it may be possible to use geographic distance between birthplaces of parents as an indicator of hybridity in their children.

ABO Blood-Group System↗

A study of nine polymorphic systems in the population of the Po Delta.

The present work reports a study of nine genetic polymorphic systems in the area of the Po Delta where malaria was endemic since the XIV century. Our data confirm some characteristics of this population already reported by other authors such as the high prevalence of thalassemia, the low prevalence of the rh (d) gene and the presence of G-6-PD deficiency. Among the other systems studied, i.e., AP, PGM1 ADA and AK, only AP frequencies of Po Delta population are significantly different from those of other continental Italian populations, the PC allele showing the lowest frequency so far observed.

Acid Phosphatase↗

Neurophysiology of photically induced epilepsy in Papio papio.

This chapter critically reviews arguments supporting the role of the frontal cortex in light-sensitive epilepsy of the baboon Papio papio in the light of the most recent neurophysiological research. In particular, it is known that spontaneous or ILS-induced paroxysmal discharges, as well as generalized seizures, originate in the frontorolandic cortical region. In this region during ILS, neurons behave in the same manner as hyperexcitable neurons in focal epileptogenic lesions of animals and man. Aso, section of the corpus callosum causes deterioration or even destruction of the synchronization that exists naturally between the two frontorolandic areas. Lastly experimental focal irritative lesions enhance light sensitivity if they are located in the frontorolandic region and inhibit it if they are located in the occipital cortex. Opposing these arguments are those that support the important role the occipital cortex plays, since its ablation makes excessive light sensitivity in the baboon disappear. Studies of the primary and nonprimary visual messages and pathways have also contributed evidence. In particular, demonstration of the existence of large numbers of direct occipitofrontal connections may help reconcile the two opposing arguments. Other evidence favoring the role of the frontal cortex is furnished by the still fragmentary studies on activation of the motor pathways and by studies in neuropharmacology. The significance and value of this type of epilepsy as an animal model of the generalized reflex epilepsies of man are discussed.

Aluminum↗