Biomedical subjects

G Scalera

Publications and source records attributed to G Scalera.

At least 19 recordsLinked to original sources

PubMed2001

Sapid solutions and food intake in repeated dehydration and rehydration periods in rats.

In a previous report, it has been shown that water deprivation significantly affects the two-bottle taste preferences and one-bottle taste acceptance in rats when no food was available during tests. Since no food was available, the course of drinking was never interrupted by eating. Theoretically, if a rat faces a simultaneous choice between food and fluid, and if the course of drinking is interrupted by eating, these conditions might interfere with taste preferences, total fluid intake and eating in thirsty rats. The aims of the present experiments were: to ascertain whether food intake during both two-bottle preference and one-bottle acceptance tests in thirsty rats might be influenced by the palatability of the solutions; to verify whether the availability of food during tests influences taste preference and acceptance, and total fluid intake; to detect variations induced by dehydration on body weight and some plasma and urinary parameters that might interfere with food and fluid intake, taste preference and acceptance. Using naive rats, five groups of rats showing the same taste preferences for one of four prototypical tastes and water were selected. Then, both two-bottle preference (Expt 1) and one-bottle acceptance tests (Expt 2) were performed in rats deprived of water for either 12, 24, 36 or 48 h. The results showed that in both Expt 1 and Expt 2, inhibition of feeding and decrease of body weight during dehydration was very similar in all rats. The presence of food during the tests did not affect taste preference and acceptance. During Expt 1, after severe water deprivation (36 and 48 h), food intake was related to the palatability of the solution paired with water. When rats drank either NaCl or sucrose, they ate less food than rats drinking HCl, quinine, or water. In Expt 2, rats drinking NaCl solution as the only source of fluid ate significantly less food than all other groups. The intake of sucrose and/or NaCl solutions be may explained by two different post-ingestion effects (energetic and osmotic). Since rats drinking either sucrose or NaCl ate less food but drank more fluid, they had a significantly higher fluid/food intake ratio than that of rats who drank water, quinine, or HCl, who ate more food but drank less fluid. The increase of the fluid/food intake ratio in rats drinking sucrose or NaCl was directly correlated with the length of dehydration. Self-denial of food during dehydration may be responsible for overeating and overdrinking during the recovery period after tests. After dehydration lasting for 24 and 48 h, plasma [Na(+)], [protein], osmolality and haematocrit values increased but [K(+)] decreased. Urinary volume decreased but urinary [Na(+)] increased. These results are related to food and fluid intake, taste preference and acceptance after dehydration periods. Experimental Physiology (2001) 86.4, 489-498.

Animals↗

PubMed2001

[Indications for laparoscopic treatment of incisional hernias].

OBJECTIVE: The aim of this article is to describe the technique used in the treatment of ventral hernia using the laparoscopic method and at the same time to evaluate the possible advantages of this surgical approach. METHODS: The clinical case we present regards a case of a patient who had undergone a double eventration treated with an application of a new type of prosthesis Parietex Composite of the Sofradim, using the laparoscopic method, we can be applied in intraperitoneal in contact with the intestinal loops. RESULTS: The method we used in the laparoscopic treatment of ventral hernias has highlighted, in a short time, the solidity of the abdominal wall, a noticeable reduction of infections and a reduction of hospitalization. There developed no long term recurrence in our patients treated with this technique. CONCLUSIONS: Laparoscopic ventral hernia treatment is currently used in a limited amount even though this pathology could be approached using the laparoscopic method. Our laparoscopic method, using the Composite prosthesis could represent a very valid method for primary and recurrent ventral hernia. This technique gives the opportunity to repair the eventration applying a prosthesis without any muscular tension, consenting, furthermore a reduction of any complications (infections, seroma, pain) that could arise and of any recurrence after the operation. Furthermore the surgical access is minimum and as we know this is of noticeable importance in aesthetics today.

Hernia, Ventral↗

PubMed2000

Taste preference and acceptance in thirsty and rehydrated [correction of dehydrated] rats.

Experiments were designed to determine whether water deprivation affects taste preferences and/or taste acceptance. In experiment 1, both five- and two-bottle preference tests were performed in normally hydrated rats to permit the selection of five groups of rats showing the same taste preference for one of four prototypical tastes. Subsequently, in the same groups of rats, taste preferences were determined by a two-bottle test (experiment 2), and taste acceptance by a one-bottle test (experiment 3), following 12, 24, 36, and 48 h of water deprivation. After both 12 and 24 h of dehydration, during the first 10 min of the tests of experiment 2, all rats ingested greater volumes of either NaCl or sucrose solution than water, but more water than either HCl or quinine solution, and the differences were very significant (P<.0001). After 36 or 48 h of dehydration, the differences became very small and, in some cases, the P-values were at the lowest or borderline level of the significance, suggesting that dehydrated rats poorly discriminate the nature of the fluid drunk. During the 11-60 min interval, all rats preferred either sucrose or NaCl to water, but water to either HCl or quinine. Experiment 3 was performed to ascertain whether the need for fluid might overcome the palatability of solutions. All rats, dehydrated for 36 or 48 h, after 10 min of exposure, drank equal amounts of fluid, independent of its palatability. During the 11-20 and 21-60 min interval, the fluid intake of rats changed in accordance with the palatability of the solution available. In conclusion, severe thirst in rats may override the palatability of the solutions, and the thirst drive may be so strong that they do not reject fluids because body fluid balance would be severely compromised.

Animals↗

PubMed1998

Somatostatin administration modifies food intake, body weight, and gut motility in rat.

The effects of a long period of relatively high and nearly constant levels of Somatostatin (SRIF) on the control of food ingestion and body weight gain were investigated; weight gain occurs via concurrent modifications of food and fluid intake and in vitro gut motility. Fluid intake was not influenced by SRIF treatment. Food intake, body weight, body weight gain, and gut motility decreased after SRIF treatment, and, in some cases, these effects were dose-dependent. Food intake increased significantly during light phase of SRIF treatment. Thus, SRIF treatment produces facilitation of food intake in the light and inhibition in the dark. The suppression seen in the dark may be the result of a preferential activation of the inhibitory response. The increase of food intake during the light may be explained by a decreased availability of body fats as fuels for metabolism since SRIF inhibits GH release, which is involved is the breakdown of adipose tissue into fuels; lower fats synthesis during nocturnal feeding; or both. Decreased gastrointestinal motility also may explain the lower food intake and decreased body weight gain following SRIF treatment.

Animals↗

PubMed1998

Somatostatin administration alters taste preferences in the rat.

The effects of long-term and relatively constant concentrations of somatostatin (SRIF) were tested in rats to investigate its influence on taste preferences, fluid intake, and taste bud topography of the tongue. In SRIF-treated rats, intake of 3 x 10(-2) M NaCl and 6 x 10(-2) M sucrose solution decreased, whereas that of 3 x 10(-5) M quinine-HCl and 10(-3) M HCl (pH = 3) solutions increased significantly; distilled water intake and total fluid consumption remained almost unchanged. The light/dark cycle of consumption of NaCl solution was modified in a dose-dependent manner, but that of dwater, total fluids, and other solutions was not. Histologic exam by light microscopy showed that taste bud distribution on the tongue appeared to be altered, but the results only approached statistical significance. Given that it is possible to remove virtually all taste buds in the oral cavity and have only modest effects on preferences and aversion, it seems very unlikely that the small changes in taste bud distribution are related to the intake of sapid solutions. Since SRIF treatment influenced all sapid stimuli, it seems more likely that the changes are based on a blunted responsiveness in the gustatory system as a whole.

Acids↗

PubMed1998

The parabrachial nucleus is essential for acquisition of a conditioned odor aversion in rats.

Rats with bilateral ibotenic acid lesions of the gustatory zone of the parabrachial nuclei (PBN) failed to acquire a conditioned taste aversion (CTA) in Experiment 1. They also failed to acquire a conditioned odor aversion (COA) when the olfactory cue was presented on an odor disk in Experiment 2 or when it was presented in water in Experiment 3. The failure to acquire the COA was not due to an inability to detect or use olfactory stimuli because the lesioned rats displayed neophobia to a novel odor in Experiment 3 and used an olfactory cue to predict the availability of an aversive capsaicin solution in Experiment 4. Together, the results demonstrate that, as with CTA learning, PBN cell bodies are essential for the establishment of a specific association between an olfactory conditioned stimulus and a lithium chloride unconditioned stimulus.

Analysis of Variance↗

PubMed1997

Gustatory functions, sodium appetite, and conditioned taste aversion survive excitotoxic lesions of the thalamic taste area.

Rats with bilateral, electrophysiologically guided, ibotenic acid lesions of the gustatory thalamus (THLX) were tested for their ability to perform a variety of taste-guided behaviors. First, in daily 30-min sessions, the rats were given repeated 10-s access periods to a range of concentrations of sucrose, NaCl, or QHCl, plus water. Both the control and the THLX rats exhibited similar concentration-response functions, regardless of hydrational state. Next, on 3 trials, the rats were given 15 min access to 0.3 M l-alanine and then injected with LiCl (0.15 M, 1.33 ml/100 g body weight ip). All rats learned a taste aversion following 1 pairing with LiCl. Finally, on 3 separate occasions, the rats were injected with furosemide, and Na(+)-appetite was evaluated 24 hr later. All rats expressed an equivalent sodium appetite after the first furosemide injection, but only the control rats increased intake of 0.51 M NaCl with repeated sodium depletions. These observations reinforce prior data implying that an intact gustatory thalamus is not necessary for the expression of some taste-guided behaviors.

Animals↗

PubMed1996

Combined therapy with zidovudine, recombinant granulocyte colony stimulating factors and erythropoietin in asymptomatic HIV patients.

The aim of this randomized, comparative, double-blind study was to determine the efficacy of zidovudine (ZVD) either alone or in combination with recombinant granulocyte-colony stimulating factors (rG-CSF) and erythropoietin (Epo) in asymptomatic HIV-infected subjects with a CD4+ cell count < 500/mm3, classified as CDC II stage. We recruited 20 HIV Ab+ asymptomatic patients who were randomized into two groups: A and B. Group A was treated with ZVD at the dosage of 500 mg daily in combination with rG-CSF (10 micrograms/Kg/biweekly) and Epo (50 IU/Kg/biweekly). Group B was treated with ZVD (500 mg/day) alone. The primary end-point was progression to an AIDS-defining event and the secondary end-point included changes in the CD4+ cell count, p24 Ag status, beta-2-microglobulin, and ferritin levels. The patients of Group A showed no significant changes in transaminase, ferritin and beta-2-microglobulin levels while CD4 cells, Hb and neutrophil levels increased significantly compared to Group B (p < 0.001) and baseline values (p < 0.05). Conversely, 5 patients in Group B showed a significant decrease in CD4 cells (p < 0.01), Hb and neutrophil levels (p < 0.01) compared to baseline values, while beta-2-microglobulin increased (p < 0.05) compared to initial values. Our preliminary study may indicate that the combination of zidovudine with these hematopoietic growth factors could reduce the possibility of virus-related hematologic toxicity and could be more efficacious than zidovudine alone in prolonged therapy.

Adult↗

PubMed1995

Parabrachial nucleus lesions impair feeding response elicited by 2,5-anhydro-D-mannitol.

Systemic injection of the fructose analogue 2,5-anhydro-D-mannitol (2,5-AM) elicits a feeding response and induces c-fos activity in the parabrachial nuclei (PBN). We used bilateral ibotenic acid lesions of PBN to determine whether the activation inferred from c-fos activity was causally related to the feeding response. The relationship between the PBN lesion and feeding behavior was also examined with the glucose analogue 2-deoxy-D-glucose (2-DG). The PBN lesions interfered with the feeding response to 2,5-AM but spared the feeding response to 2-DG. Rats were also tested in a conditioned taste-aversion paradigm. Differences were observed in the relationship between lesion extent and behavioral deficit for feeding responses to 2,5-AM and taste-guided intake after taste-aversion conditioning. These data provide the first demonstration that central lesions can disrupt feeding responses to peripherally acting 2,5-AM. The results suggest that the neural substrate for this response differs from that mediating taste-aversion conditioning and from that involved in the feeding response to 2-DG.

Animals↗

PubMed1995

Gustatory detection thresholds after parabrachial nuclei lesions in rats.

Rats with either electrolytic (Experiment 1) or excitotoxic lesions (Experiment 2) that had been electrophysiologically centered in the gustatory zone of the parabrachial nuclei (PBN) were tested for sucrose and NaCl taste detection thresholds in a conditioned avoidance task. With 1 exception, all of these rats had previously shown severe deficits in acquiring an LiCl-based conditioned taste aversion (CTA) to sucrose, NaCl, or alanine. The rats with excitotoxic lesions also had failed to express a depletion-induced sodium appetite. Despite the uniformity of these deficits, the rats with lesions exhibited varied performance in the detectability task. Roughly 1/3 of the rats did not perform competently, 1/3 had elevated thresholds, and 1/3 showed no or only marginal impairments in taste detectability. These findings demonstrate that the elimination of CTA following PBN lesions is not necessarily linked to an impairment in taste signal detection. Thus, PBN-induced deficits on 1 taste-related task do not entirely correspond with impairments on another.

Animals↗

PubMed1995

Excitotoxic lesions of the parabrachial nuclei prevent conditioned taste aversions and sodium appetite in rats.

Electrolytic lesions of the parabrachial nuclei (PBN) disrupt conditioned taste aversion (CTA) in the rat, but it is not known whether this effect is due to damaging axons of passage or to destruction of intrinsic neurons. We tested 10 rats with electrophysiologically guided, ibotenic acid lesions of the PBN (PBNx) to determine whether they could acquire a LiCl-induced CTA to l-alanine (0.3 M) or demonstrate a sodium appetite following furosemide treatment and overnight access to sodium deficient chow. Vehicle-treated and nonsurgical controls were included in the design. PBNx rats failed to develop a CTA, even after 3 conditioning trials. Moreover, more than 8 months later, a subset of the PBNx rats were again unable to learn a CTA using NaCl as the conditional stimulus (CS). After the furosemide treatment, the control rats drank an average of 20.3 ml of strong salt in 24 hr. The PBNx rats drank virtually no NaCl during the first 2 hr and averaged only 4.0 ml in 24 hr. In the PBN, damage to neuronal somata is more critical than interrupting fibers of passage for producing deficits in taste-guided behaviors.

Afferent Pathways↗

PubMed1992

Taste preferences, body weight gain, food and fluid intake in singly or group-housed rats.

Two behavioral experiments were performed to determine if the housing conditions modify taste preferences, body weight gain, food and fluid intake, and alimentary diurnal pattern in adult male rats. In Experiment 1, a two-bottle 24-h preference test (salt, sweet, sour, bitter solutions versus deionized water) was performed in singly, dually or multiply housed rats. In Experiment 2, the same sapid solutions as Experiment 1 and water were contemporaneously offered to singly, dually, or multiply housed rats. Crowded rats drank more water, sweet solution, and total fluid, but less salt solution than singly or dually housed rats during dark and whole-day periods. All rats preferred sour solution, but not bitter solution, to water. In both experiments, crowded rats gained less body weight and ate less food than dually or isolated rats. These results suggest that the housing conditions influence taste preferences, food and fluid intake, body weight gain, but not alimentary diurnal pattern in rats. An important implication of these results is that in experiments in which appetite and taste are dependent variables, all rats should be housed under the same social and environmental conditions.

Animals↗

PubMed1991

Effects of corticocerebellar lesions on taste preferences, body weight gain, food and fluid intake in the rat.

The experiments reported here attempted to examine in two groups of rats the effects on the taste preferences, food and fluid intake, energy balance and body weight gain of corticocerebellar lesions involving, primarily, the Lobulus VI (LVI) or the Lobulus Paramedianus (LP). The results showed that the lesions of LVI or LP did not affect the daily intake of total fluid and salty solution. The intake of sweet solution increased in both groups of lesioned rats, while the intake of deionized water and acid and bitter solutions decreased only in the LVI lesioned rats. Food intake decreased in the LVI-lesioned rats but not in the LP-lesioned animals. Body weight gain, efficiency of food utilization, caloric intake and body surface gain decreased in both groups. It seems therefore that the cerebellar cortex, which probably receives taste fibers, somehow influences taste preferences and water intake, and that it may be involved in the mechanisms of food intake, its utilization and body energy balance.

Animals↗

PubMed1990

Pineal involvement in the alimentary behavior and taste preferences in the rat.

The purpose of this experiment was to explore the effects of pinealectomy or sham pinealectomy on circadian rhythms of taste preferences, food and fluid intake and body weight gain in rats. We compared the body weight gain, the amounts of food eaten and that of deionized water, total fluid, salt, sour, sweet and bitter near-threshold solutions consumed by rats before all surgical manipulations and after pinealectomy or sham pinealectomy. The results showed that the pineal gland does not exert a major influence on circadian organization of taste preferences, drinking, feeding and body weight modifications in the rat. The failure of pinealectomy to modify light/dark rhythms of taste preferences and other related alimentary behaviors may be explained by the fact that pinealectomy does not completely eliminate circulating melatonin.

Animals↗

PubMed1981