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Biomedical subjects

P Ruggeri

Publications and source records attributed to P Ruggeri.

At least 55 records · Page 3Linked to original sources
PubMed1989

Effects of intraoral mechanoreceptor stimulation on reticular formation neurones, in the rabbit.

The effects of intraoral mechanoreceptor stimulation on the firing rate of single neurones of the brain stem reticular formation (RF) were investigated in rabbits. 30% of RF neurones responded to periodontal mechanoreceptor stimulation; 16% to mucosal mechanoreceptor stimulation and 6% to both types of stimuli. Periodontal stimulation induced mainly inhibitory effects localized within the mesencephalic and rostral pontine RF. Among periodontal afferents incisors were the most widely represented. The effects of mucosal mechanoreceptor stimulation were predominant in the medullary and pontine RF and they were mainly excitatory. The present results support the hypothesis that brain stem RF neurones can be recruited into regulating mastication and biting also by stimulation of intraoral mechanoreceptors.

Action Potentials↗
PubMed1987

Effects of corticosterone on neurones of the locus coeruleus, in the rat.

The effects of microelectrophoretic application of corticosterone (CS) on single neurones of the locus coeruleus (LC) were investigated in rats under urethane anaesthesia. Ejecting currents generally ranged from 10 to 60 nA. CS produced an excitatory effect in 73% of the neurones and no effect in 27%. The prevailingly excitatory effects induced by CS on LC neurones may be related to the regulation of those complex events, which constitute the 'stress response'.

Animals↗
PubMed1987

Effects of corticosterone on neurons of reticular formation in rats.

The effects of microelectrophoretic application of corticosterone (CS) on single neurons of the brain stem reticular formation (RF) were investigated and then compared with the effects produced on the same neurons by intravenous administration of CS. The experiments were done in two groups of rats, one anesthetized with urethan and the other with pentobarbital sodium because these anesthetics cause different increases of basal concentration of plasma CS. Microelectrophoretic application of CS to neurons in the caudal portion of RF caused primarily excitatory effects, whereas inhibitory effects were observed in neurons of the rostral portion of the RF. The intravenous injection of CS (5 micrograms/100 g body wt) always produced the same effects as microelectrophoretic application. Under our experimental conditions the increase in plasma CS concentration produced by the intravenous injection of CS was found to be within the physiological range for the rat. The different anatomical distribution of units within the RF responding with either excitation or inhibition may be related to functional differences of the two RF areas.

Animals↗
PubMed1986

Influence of several aldehyde dehydrogenase and aldehyde reductase inhibitors on diamine oxidase in rat brain.

Pyrroline formation in rat brain was studied in presence of different inhibitors of AldDH, AldR, ADH and MAO. The inhibition of AldDH and AldR, but not of ADH and MAO significantly increased DAO activity. The results indicate that the use of appropriate aldehyde metabolizing enzymes inhibitors allows to better understand the role of diamine oxidase in rat brain putrescine catabolism.

Alcohol Dehydrogenase↗
PubMed1985

Effect of intraventricular putrescine on adenosylmethionine decarboxylase in rat hypothalamus and caudate nucleus.

Effects of intracerebroventricularly injected putrescine on adenosylmethionine decarboxylase activity in rat hypothalamus and caudate nucleus were studied. Doses that lacked the capacity to produce behavioral and electrocortical epileptogenic disorder caused a significant activation of enzyme occurring between 10 and 15 min after injection. The changes in hypothalamic and caudate nucleus enzyme activity after putrescine administration were dose-dependent, and they supported the assumption that limiting putrescine concentration in vivo may play a role in adenosylmethionine decarboxylase regulation.

Adenosylmethionine Decarboxylase↗
PubMed1984

Effect of microelectrophoretically applied corticosterone on raphe neurones in the rat.

The effect of microelectrophoretic application of corticosterone (CS) on single neurones of raphe nuclei (RN) were investigated in rats under urethane anaesthesia. Ejecting currents generally ranged from 5 to 40 nA. CS produced an excitatory effect in 61% and no effect in 39% of the neurones. None of the 54 neurones studied was inhibited by CS. These quite homogeneous data support the hypothesis that RN are involved in the regulation of most of the nervous functions in which glucocorticoid hormones have been implicated.

Action Potentials↗
PubMed1983

Actions of microelectrophoretically applied glucocorticoid hormones on reticular formation neurones in the rat.

The effects of microelectrophoretic application of hydrocortisone (HC) and corticosterone (CS) on single neurones of the brainstem reticular formation (RF) were investigated in rats under urethane anaesthesia. Ejecting currents generally ranged from 5 to 20nA. HC and CS behaved similarly in that they produced an excitatory effect in 26% and 24% of the neurones, respectively, an inhibition in 15% and 17% and no effect in 59% of neurones. The excitatory effects predominated in the caudal portion of the FR and the inhibitory effects in the rostral RF. The different distribution of the effects may be related to functional differences between the two RF areas.

Animals↗
PubMed1983

Monoamino-oxidase activity in rat pineal gland. Histochemical studies.

Monoamine-oxidase (MAO) activity was detected in rat pineal gland with dopamine, 5-hydroxytryptamine (5-HT), norepinephrine and tryptamine as substrates, and nitroblue tetrazolium salt as electron acceptor. Pinealocytes stained deeply when 5-HT was the substrate. Dopamine and tryptamine substrates gave similar patterns, with moderate activity in the pinealocytes. Norepinephrine reactivity was detected in the nerve-endings.

Animals↗
PubMed1982

S-adenosylmethionine decarboxylase levels in rat retina during postnatal development.

S-Adenosylmethionine decarboxylase from rat retina is similar to that isolated from other rat tissues with regard to kinetic parameters, pH optimum, putrescine requirement, and sensitivity to spermine. The enzymic activity increases during the first 7 days of postnatal life but decreases until the 20th day. After this period AdoMet decarboxylase activity increases, to reach the highest values at the 90th day. This behavior suggests that such enzymic activity is responsible for spermidine and spermine levels in rat retina and that a high content of retinal spermine might have a role in the photoreceptor outer segment renewal.

Adenosylmethionine Decarboxylase↗
PubMedDate not supplied

Clindamycin for colonization and infection by methicillin-resistant Staphylococcus aureus.

Effective antimicrobial therapy for infection or colonization by methicillin-resistant Staphylococcus aureus (MRSA) is very limited. In some institutions, the majority of strains remain susceptible to clindamycin in vitro. We report five patients with colonization or infection of varying severity caused by MRSA who had the organism successfully eradicated by clindamycin. In one patient who had an MRSA infection that persisted during vancomycin therapy clindamycin therapy was able to finally eradicate the organism. Clindamycin should be seriously considered as alternative therapy for colonization or infection by MRSA.

Aged↗