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Biomedical subjects

M Gallo

Publications and source records attributed to M Gallo.

At least 19 recordsLinked to original sources
PubMed1992

Differential involvement of gustatory insular cortex and amygdala in the acquisition and retrieval of conditioned taste aversion in rats.

Lesion studies of the role of the gustatory insular cortex (GC) and amygdala (Am) in conditioned taste aversion (CTA) are confounded by the irreversibility of the intervention. Functional ablation methods allow more specific influencing of different phases of CTA acquisition and retrieval. Bilateral tetrodotoxin (TTX) blockade of GC (10 ng) or Am (3 ng) before or after saccharin drinking in rats with chronically implanted intracerebral cannulae showed that GC is indispensable for the initial processing of the taste stimulus but not for the association of the gustatory trace with the symptoms of LiCl poisoning. Gustatory signals can by-pass the blocked Am, the inactivation of which, however, impairs the gustatory trace-poisoning association. TTX injection into both GC and Am impairs CTA retrieval more than isolated blockade of either of these structures. It is argued that GC and Am implement processing of gustatory and visceral signals, respectively, but that formation and consolidation of the CTA engram proceeds outside forebrain, probably at the level of the brainstem.

Amygdala↗
PubMed1992

Influence of estrogens on calcitonin secretion.

In this study we investigated the calcitonin (CT) pattern both in basal conditions and after calcium infusion before and one month after oophorectomy in 17 premenopausal women. In addition, 13 oophorectomized women were randomly allocated to two groups, one given hormone replacement treatment and the other untreated, and CT response to hypercalcemia was reevaluated one year later. CT response to calcium infusion was significant only before oophorectomy and one year after estrogen-progestogen treatment, whereas there was no response one month after oophorectomy or after one year without hormone replacement therapy. Our data indicate that both estrogen secretion and replacement treatment may be important factors in CT response.

Adult↗
PubMed1992

Study of interaction of styrene oxide with angiotensin by mass spectrometry.

The present study describes how mass spectrometry was extensively applied to the characterization and quantification of modified amino acids within the polypeptide chain of Angiotensin I, chosen as model substrate, combining the use of fast atom bombardment mass spectrometry with gas chromatography--mass spectrometry. The reaction products after in vitro incubation of Angiotensin I with styrene oxide, a well known carcinogen, under different conditions, have been characterized: a prominent reactivity of several potential nucleophilic sites of Angiotensin I was shown, including two histidine residues and a tyrosine residue; it is worth noting that it has never been stated that tyrosine is highly reactive with styrene oxide. The results obtained demonstrate the usefulness of mass spectrometry for the structural determination of chemically modified amino acids in peptides and proteins, and the presence of a reliable relationship between reaction conditions and the production of alkylated amino acids. This characterization procedure offers the possibility of identifying reactive sites following exposure to unknown alkylating agents.

Angiotensin I↗
PubMed1992

[Treatment of systemic lupus erythematosus with intravenous human immunoglobulins. Preliminary study].

Recently the availability of human immunoglobulin for intravenous use (IVIg) has been helpful in the treatment of some conditions characterized by autoimmune disorders and anecdotal reports have been suggested a favourable role in the therapy of SLE. We report our experience on 4 SLE patients in whom IVIg was administered. Our data suggest that IVIg may be considered an alternative regimen to treat selected patients affected by SLE.

Adult↗
PubMed1991

Acquisition of conditioned taste aversion in rats is mediated by ipsilateral interaction of cortical and mesencephalic mechanisms.

The possibility to lateralize the neural circuits mediating conditioned taste aversion (CTA) has been examined by combination of functional hemidecortication and unilateral tetrodotoxin (TTX) injection into the parabrachial nucleus (PBN). Rats drinking saccharin (CS) during cortical spreading depression (CSD) in the right hemisphere and receiving unilateral PBN injection of TTX (3 ng) shortly before i.p. injection of lithium chloride (LiCl) (US) formed CTA when CSD and TTX were applied to the same hemisphere but not when applied to different hemispheres. Rats drinking saccharin with intact brain and receiving unilateral TTX overlapping with LiCl administration learned a weak CTA, the retrieval of which was disrupted by either ipsilateral or contralateral CSD during retention testing. It is concluded that CTA acquisition requires cooperation of ipsilateral cortical and subcortical centers but that formation of unilateral subcortical CTA engram does not warrant lateralization of the retrieval process.

Animals↗
PubMed1991

[IgG paraproteinemia and arthritis. Description of a clinical case].

The case is reported of a patient with monoclonal gammopathy of undetermined significance (M.G.U.S.) in whom suddenly an acute polyarthritis appeared. Upon differential diagnosis, this arthropathy was attributed to the precipitation of paraprotein-containing complexes within the synovial fluid leading to an inflammatory articular reaction. Treatment with low doses of methylprednisolone lead to complete remission of this arthritis.

Arthritis↗
PubMed1991

Participation of the area postrema in learned aversions induced by body rotation.

Existing data on the effects of area postrema (AP) lesions on body rotation-induced emesis as well as on the participation of this zone in the acquisition of taste aversion learning (TAL) with other emetic agents suggest a possible role for the AP in learned aversions induced by body rotation. Nevertheless, earlier studies have shown that AP lesions do not prevent learned aversions induced by body rotation. The present experiments were performed in male Wistar rats in order to explore the effects of AP lesions on body rotation-induced flavor aversions as a function of the paradigm employed. Flavor aversions were induced by 30 min of circular body rotation (90 r.p.m.) using two different paradigms: a standard one including one trial learning, delay and single stimulus test and a three trials paradigm (with and without interstimulus delay) including both single stimulus test and choice test. AP lesions disrupt acquisition provided that the paradigm used includes interstimulus delay, i.e. when body rotation is applied 15 min after flavor intake. However, the AP seems to play no essential role when body rotation is applied immediately after flavor intake in a three-trial paradigm, as no effects were observed following AP lesions. In addition, subdiaphragmatic vagotomy plus simultaneous AP lesions leads to no interference in the acquisition of learned aversions induced by body rotation applied immediately after intake. It is concluded that body rotation may trigger a variety of aversive effects capable of inducing learned aversions, each apparently involving independent neural systems.

Animals↗
PubMed1991

Evidence for peripheral impaired glucose handling in patients with connective tissue diseases.

Sixteen patients suffering from rheumatoid arthritis (RA) (n = 8), systemic lupus erythematosus (SLE) (n = 5), and systemic sclerosis (SSc) (n = 3), and 10 healthy subjects matched for age, sex, and body mass index, were submitted to an intravenous (IV) glucose tolerance test (GTT) (0.33 g/kg of body weight in 3 minutes) and to a euglycemic hyperinsulinemic glucose clamp to study insulin response and action. In the euglycemic clamp, along with the two insulin infusion rates (0.5 mU/kg.min from 0 to 120 minutes and 1 mU/kg.min from 121 to 240 minutes), a primed (20 microCi) continuous (0.2 microCi/min) infusion of 3H-glucose allowed determination of glucose kinetics. Our data show that patients versus controls have (1) a significant increase in basal plasma insulin levels (87.2 +/- 14.8 v 41.3 +/- 6.0 pmol/L, P less than .05); (2) similar glucose-induced acute insulin response; and (3) a lower glucose disappearance rate (Rd), glucose metabolic clearance rate (gMCR), and glucose infusion rate (GIR) when the lowest insulin infusion rate was delivered. These differences disappeared when the insulin infusion rate was doubled. Furthermore, basal plasma insulin levels and glucose disappearance rate significantly correlated with the main inflammatory indices of each disease studied. We conclude that in our patients impaired glucose handling is mainly due to peripheral insulin resistance.

Arthritis, Rheumatoid↗
PubMed1991

Differential effects of subdiaphragmatic vagotomy on NaCl-induced aversion learning.

The vagus nerve has been proposed in numerous studies as one of the peripheral mechanisms involved in drug-induced taste aversion learning, although available data have been controversial. The differential results obtained in the present series of experiments with vagotomy and NaCl-induced short-term and long-term aversion learning suggest that the vagal system plays a decisive role in tasks requiring the rapid detection of an aversive substance in the gastrointestinal tract (short-term tasks). In contrast, this mechanism appears to be unnecessary in long-term tasks, where learning may be mediated by alternative slower-acting peripheral mechanisms such as the humoral system.

Animals↗
PubMed1991

Effect of systemic exposure to parathion on the dark adapted pupil dilation of cynomolgus monkeys.

The constriction of pupil dilation following dark adaptation was studied as a potentially useful biological monitor of systemic exposure to organophosphorus pesticides (OPs). Pupil dilation and blood cholinesterase levels were monitored in 4 cynomolgus monkeys following oral administration of 2.0 mg/kg parathion in corn oil. No consistent pattern of change in pupil/iris diameter ratios following exposure was found despite depressions in blood cholinesterase activities of 27-50% for red cells and 65-80% for plasma. A slight mydriasis was observed in one of the monkeys, who appeared the most affected behaviorally by the exposure. Results of this work suggest that the measurement of pupil dilation after dark adaptation is not a sensitive indicator for systemic exposure to OPs. However, in situations where direct exposure to the eyes may occur, such as during aerial or airblast pesticide applications, other studies indicate that constriction of pupil dilation can occur at exposure levels below those resulting in systemic effects.

Animals↗
PubMed1990

[Effects of ketanserin on glucose metabolism in hypertensive diabetic subjects].

In this report the Authors have verified the effects of Ketanserin on glycaemic metabolism of type II diabetic subjects with a moderately high blood pressure. They think that a therapeutic dose of drug is not able to considerably inhibit insulin production. The Authors can assert that the Ketanserin does not influence the glycaemic regulation by therapeutic dose, neither does it increase the diabetic disease, nor disturb the oral hypoglycaemic therapy though it normalizes high blood pressure.

Diabetes Mellitus, Type 2↗
PubMed1990

[Evaluation of the effect of picotamide on platelet function in diabetic subjects].

In this study the Authors verify the results of Picotamide on platelet aggregation in diabetic subjects. The results suggest that Picotamide has no influence on insulin or oral treatment of diabetic subjects. However, it is certain that platelet aggregation by ADP or collagen decreases due to the effect on thromboxane probably because of the limitation of platelet receptors.

Adenosine Diphosphate↗