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Biomedical subjects

G Amato

Publications and source records attributed to G Amato.

At least 145 records · Page 8Linked to original sources
PubMed1985

Radionuclide techniques in the study of delayed gastric emptying in patients with gastroesophageal reflux.

Gastric emptying was studied in 15 patients with hiatal hernia and gastroesophageal reflux by a radionuclide technique with solid meal. Thirteen healthy subjects were used as control group. The obtained results have shown that, even in the time when the radionuclide activity decreases of 50% in the region of gastric activity (T1/2) in the 15 patients was not statistically different with respect to the control group, ten patients showed delayed emptying (116.4 +/- 16.88 min) with a mean delay of 30% in the time of half-emptying with respect to the control group (p less than 0.01). This finding is important for its surgical implications since this delayed emptying should be kept in mind when planning Nissen fundoplication or other antireflux procedures: in such case surgery can be complicated with a "gas bloat syndrome".

Adult↗
PubMed1984

[Effects of stimulation of the substantia nigra on the rage reaction evoked in the cat by hypothalamic stimulation].

The effects of substantia nigra stimulation on the rage reaction evoked by hypothalamic activation were studied. The reference value of the rage reaction was the latency of the hissing, which was constant in all animals when hypothalamic stimulation was performed with the same parameters. Simultaneous activation of substantia nigra and hypothalamus determined a significant decrease of the hissing latency. The influence of the substantia nigra on the affective components of the aggressive behaviour in underlined.

Anger↗
PubMed1984

[Induced facilitation in the ventral tegmentum area on the latency of biting evoked by hypothalamic stimulation in the cat].

The effects of VTA stimulation on the quiet biting attack evoked by hypothalamic activation in the cat, were studied. The reference value of the aggressive behaviour was the latency of the biting. Concurrent activation of both the hypothalamus and VTA determined a decrease of the biting latency, which depended on the parameters of VTA stimuli. The facilitatory effect of the dopaminergic mesolimbic system on the attack behaviour is emphasized.

Aggression↗
PubMed1984

[The substantia nigra in quiet attack induced by hypothalamic stimulation in the cat].

The role of the substantia nigra on the quiet biting attack evoked by hypothalamic stimulation was investigated. Simultaneous activation of the hypothalamus and of the s. nigra determined a significant increase of the biting latency or in some case the disappearance of the attack pattern. The inhibitory role of the s. nigra on the quiet biting attack evoked by hypothalamic stimulation is discussed.

Aggression↗
PubMed1984

[Functional aspects of the relation between the claustrum and motor cortex in the cat].

In order to study the relationships between the claustrum and motor cortex neurons both of area 4 and area 6 in the cat, an experiment was performed in which the effect of claustral stimulation on pyramidal tract neurons was investigated. Single shock electrical activation of the claustrum caused an inhibition of the spontaneous activity of the neurons, or an inhibition preceded by short activation, or no effect. These evidences lead to the conclusion that the claustrum exerts a role in movement organization.

Animals↗
PubMed1984

Functional relationship between claustrum and pyramidal tract neurons, in the cat.

Electrophysiological relationships between the claustrum and the motor cortex were studied in cats preliminarily anesthetized with ketamine and then with chloralose. Single shock electrical activation of the claustrum induced a decrease of the spontaneous unitary activity of the pyramidal tract neurons (PTNs) both in area 4 and in area 6. Eighty percent of the total number of PTNs was inhibited whereas the remaining 20% was unaffected. The inhibitory effect lasted about 200 msec and appeared about 19 msec after claustrum activation. The results show a functional linkage between the claustrum and the efferent cells of the motor cortex. This relationship suggests the hypothesis that the claustrum, a multisensory structure, may be involved in motor activity integration.

Afferent Pathways↗
PubMed1984

Effects of claustrum stimulation on spontaneous bioelectrical activity of motor cortex neurons in the cat.

Electrophysiologic interactions between claustrum and motor cortex neurons were investigated in the cat. A total of 136 neurons was recorded from the motor cortex in area 4 (90 cells) and in area 6 (46 cells). Ninety-eight of the total neurons were identified as pyramidal tract neurons (PTNs). Stimulation of the claustrum by single shocks or by trains of stimuli imposed on the tested PTNs a pure long-lasting inhibition, or a long-lasting inhibition preceded by a short early activation, or no effect. No functional localization of the effects of claustrum activation were found within the motor areas. The observed results are consistent with the hypothesis that the claustrum may play a role in movement organization.

Action Potentials↗
PubMed1984

ACTH and cortisol plasma levels in cancer patients treated with medroxyprogesterone acetate at high dosages.

The effects of medroxyprogesterone acetate (MPA) at high dosages on ACTH and cortisol plasma levels have been studied on seven patients which were carriers of ER+ and PR+ neoplasm. ACTH and cortisol plasma levels were studied at 8:00 a.m., before and after a 4-week treatment with MPA at dosages of 1000 mg/die at basal conditions and after a metyrapone stimulation test. The results obtained show that the MPA treatment causes a highly significant drop of both cortisol and ACTH plasma levels. The metyrapone stimulation test performed before and after MPA treatment confirms the suppressive effect of MPA on the hypothalamus-pituitary-adrenal gland axis. These data suggest a cortisol-like action of MPA with a negative feed-back mechanism on the hypothalamus-pituitary-adrenal gland axis.

Adrenocorticotropic Hormone↗
PubMed1984

TSH response to TRH in hemodialysis and CAPD patients.

The thyroid status was studied in 19 uremic patients (11 on HD and 8 on CAPD) and in a group of 17 healthy adult patients. In uremic patients T3 and T4 were significantly reduced (p less than 0.001) and rT3 was increased (p less than 0.001). The time course TSH response to TRH showed a lower peak response (in 5 patients it did not exceed 5 microU/ml) which on turn was also delayed (the peak was observed at 60 minutes in 63% of them). TSH concentrations in uremics were increased at 0 time (p less than 0.02), lower at 20 minutes (p less than 0.01) and increased at 120 minutes (p less than 0.02). No difference existed between HD and CAPD. The thyroid response to TSH was normal as showed by a normal percent increase over basal values of T3 concentrations at 120 minutes. Uremic patients also showed a peak GH response at 20 minutes which was not observed in controls. The data exclude the existence on a primary form of hypothyroidism and point to the existence of hypothalamic-pituitary abnormalities, which should not be taken as indicative of secondary and/or tertiary hypothyroidism since FT4 values were normal in HD and increased in patients undergoing CAPD (p less than 0.05) who on turn showed lower plasma albumin concentrations (p less than 0.05).

Adult↗
PubMed1984

Thyroid status and nephron loss--a study in patients with chronic renal failure, end stage renal disease and/or on hemodialysis.

Thyroid function was measured in 30 healthy subjects and 84 patients with various degrees of nephron loss (GRF: 70 +/- 15 m/min, 30 +/- 16 ml/min, 10 +/- 7 ml/min and 2.1 +/- 1.3 ml/min). A low T3 and T4 syndrome is evident when GRF is reduced to 30 +/- 16 ml/min while a blunted TSH response is detected earlier in the course of nephron loss. T3 response to TRH was normal and FT4 was not affected by renal dysfunction. The data indicate that in nephron loss hypothalamic-pituitary abnormalities occur.

Adolescent↗
PubMed1983

Impaired spreading of transformed cells on fibrin substrate.

Fibroblast-like cells derived from C3H mice at the first passage in culture, and a line from the same origin, which had undergone spontaneous transformation at the eleventh passage, were seeded on fibrin plates and tested for their attachment and spreading. After 4-24 hours normal cells had a spider-like morphology, while transformed cells remained in round clusters, flattened on the substrate. This data represent the morphological counterpart of the abnormal fibroblast-fibrin interaction shown in a tridimensional model, where transformed cells were found unable to induce the retraction of a fibrin clot (FCR).

Animals↗
PubMed1983

In vitro and in vivo cytotoxicity of possible uracil metabolites of methylxanthines.

The present study was designed to elucidate the cytotoxic potential of 8 possible substituted uracilic metabolites of methylxanthines. 5-Fluorouracil (5-FU) was used as a reference uracil analogue with cytotoxic activity. Substituted uracil derivatives examined in this study did not affect the proliferative capacity of PHA-stimulated rat lymphocytes, murine L1210 leukaemia and rat chondrocytes. Caffeine had some growth inhibitory activity of extremely high concentrations (greater than 100 micrograms/ml). In vivo administration of 6-amino-5[N-methyl-formylamino]1,3-dimethyluracil (1,3,7-TAU) and 6-amino-5[N-acetylamino]3-methyluracil (7-A3-MAU) caused a transient short-lived reduction of L1210 tumour cell numbers. These observations do not appear to support the hypothesis that substituted uracils are involved in the toxicity of high doses of caffeine in rats.

Animals↗