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B De Luca

Publications and source records attributed to B De Luca.

At least 37 records · Page 2Linked to original sources

Non-shivering thermogenesis during prostaglandin E1 fever in rats: role of the cerebral cortex.

We have tested the hypothesis that there is a role for the cerebral cortex in the control of non-shivering thermogenesis during fever induced by prostaglandin E1 (PGE1). While under urethan anesthesia, the firing rate of nerves innervating interscapular brown adipose tissue (IBAT), IBAT and colonic temperatures (TIBAT and Tc) and oxygen (O2) consumption were monitored during the fever from PGE1 injection (400 and 800 ng) in a lateral cerebral ventricle in controls and in functionally decorticated Sprague-Dawley rats. Rats were functionally decorticated by applying 3.3 M KCl solution on the frontal cortex which causes cortical spreading depression (CSD). Pyrogen injections caused dose-related increases in firing rate, TIBAT, Tc and O2 consumption and CSD reduced these enhancements. Our findings indicate that the cerebral cortex could be involved in the control of non-shivering thermogenesis during PGE1-induced febrile response.

Adipose Tissue, Brown↗

Role of seizure activity in the decreased pineal response to isoproterenol in rats chronically treated with electroconvulsive shock.

Chronic electroconvulsive shock (ECS) has been previously reported to blunt the melatonin response to acute isoproterenol administration in rats. To assess whether electrically induced seizures are indeed required for the appearance of the blunted pineal response to isoproterenol, pineal and serum melatonin levels were measured after isoproterenol stimulation in rats treated with ECS (80 mA, 0.5 sec), subconvulsive shock (15 mA, 0.5 sec), or sham-ECS once per day at 11:30-12:00 h for 8 days. In ECS-treated rats, both pineal and serum melatonin levels after isoproterenol administration were significantly lower than those in sham-treated animals and in rats receiving subconvulsive shock. Moreover, as compared with sham treatment, chronic subconvulsive shock did not affect the melatonin response to isoproterenol. These data show that seizure activity is indeed required for the ECS-induced decrease in the pineal response to acute beta-adrenergic stimulation.

Animals↗

Nitric oxide reduces the thermogenic changes induced by lateral hypothalamic lesion.

The experiment described here tests the effect of intracerebroventricular (icv) injection of nitric oxide (NO) precursors, such as L-arginine (L-arg) and nitroprusside (NP), on the thermogenic changes induced by lesion of the lateral hypothalamus (LH). The firing rate of the nerves innervating interscapular brown adipose tissue (IBAT), along with IBAT and colonic temperatures (TIBAT and TC) were monitored in urethane-anaesthetized male Sprague-Dawley rats lesioned in the LH. These variables were measured before and after an icv injection of 4 mumol L-arg or 400 nmol NP. The same variables were also monitored in: a) lesioned rats with icv administration of saline; b) sham-lesioned animals with icv injection of L-arg or NP; c) sham-lesioned rats with icv injection of saline. The results show that L-arg or NP injection reduces the increases in firing rate. TIBAT and TC induced by LH lesion. These findings suggest that NO plays a key role in the thermogenic changes following LH lesion.

Animals↗

[The diagnostic significance of the small bowel enema in lesions of the small intestine requiring surgery].

Given its anatomical location the small intestine is the section of the digestive tract most inaccessible to objective clinical and instrumental examination. For this reason, traditional investigation methods provide inadequate data. In the barium meal X-ray, images are superimposed and the barium excessively fragmented due to the tortuosity and length of the intestinal loop. Access problems limit the value of endoscopy. The indications to angiography are fairly restrictive. Ultrasound and CT scans provide no conclusive evidence in this area. The so-called Small Bowel Enema technique based on the direct infusion of an opaque contrast medium after duodenal intubation remains the only way to obtain images with a satisfactory diagnostic value and should be the method of choice in examinations of the small intestine. Introduced in the twenties, the value of the technique was long questioned, mainly because it was difficult to perform correctly and it is only quite recently that several decisive technological innovations have made it highly reliable. The present paper describes its use on a series of patients with suspected pathologies of the small intestine requiring surgical treatment. The aim is to specify the correct indications to this technique as well as its limitations with a view to promoting its appropriate use in routine practice. MATERIALS AND METHODS. The study covers 42 small bowel enemas performed on 29 male and 13 female patients aged 12-85 years. Indications to the enema included chronic abdominal pain in 28.5%, chronic diarrhea in 21.4%, pain+diarrhea in 14%, subocclusion in 16.5%, faecal blood in 11.9%, abdominal pain+diarrhea+intestinal haemorrhage in 4.7%, anaemia in 2.4%. We adopted the Sellink technique involving intubation with a French 14 Bilbao-Dotter probe and the infusion of 200-350 cc barium sulphate in a 90%-70% P/V concentration at a speed of 100 ml/min, followed by the infusion of 1000-1500 cc 0.5-1% methylcellulose in a 50-50 mixture with water for double contrast purposes. Mean duration of procedure 35-40 mins. RESULTS. We found lesions of the small intestine in 18 cases or 45% (true positives) and no alterations in 18 or 42.8% (true negatives). In 3 cases (7%) the examination was inconclusive. One false positive and one false negative complete the series, making a diagnostic accuracy of 89.1%. In 23.8% of the total series the diagnosis of Crohn's disease was confirmed; cancerous lesions were found in 11.9% and adhesions following earlier surgery in 9.7%. Surgery confirmed this diagnosis in 10 cases (5 tumours, 3 stenoses caused by adhesion fragments, 2 Crohn's disease) and disproved it in one case. Biopsy was used, for objective confirmation in 5 cases (2 Crohn's disease, 3 negatives). In the other cases reliance was placed on clinical course and the patients' response to treatment. DISCUSSION AND CONCLUSIONS. Examination of our results reveals that in most clinical cases the small bowel enema was used to confirm suspected Crohn's disease (31 cases out of 42) and with a very high degree of diagnostic accuracy (96.7%). In line with data in the literature we decided to base the indication to this examination on certain primary symptoms such as chronic abdominal pain, diarrhea, blood in the faeces, whether in isolation or in combination. On this rather general basis the diagnosis of Crohn's disease concerned only 23.8% of the cases studied, an incidence that rose dramatically in the few cases in which the indications were made more specific. We therefore conclude that the adoption of more restrictive criteria will improve the cost-benefit ratio for this test. Another major pathology in which small bowel enema possesses a high diagnostic value is partial obstruction of the small intestine.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗

The influence of exercise on energy balance changes induced by ventromedial hypothalamic lesion in the rat.

The effects of a hypothalamic ventromedial area lesion on energy balance were tested in exercising rats and in sedentary rats to add further information about the type of obesity developed after ventromedial lesion. Four groups of six male Sprague-Dawley rats were used. Group 1: sham-lesioned and sedentary rats, which were utilized as control rats (C); group 2: sham-lesioned and exercising rats (E); group 3: lesioned and sedentary rats (L); group 4: lesioned and exercising rats (LE). The exercise consisted of daily swimming for 30 min. Resting oxygen consumption, food intake, and body weight were measured before any treatment and 3 weeks after the lesion or/and the exercise period. The results showed that the oxygen consumption increased in the E and LE groups but not in the C and L groups. Food intake increased more in E and LE groups than in L group. The increases in body weight were higher in L and LE than in the E and C groups. These findings suggest that exercise modifies resting oxygen consumption and food intake in lesioned rats, but does not influence the degree of obesity. Thus, the ventromedial syndrome can be considered a type of obesity not completely unregulated.

Animals↗

Pineal response to isoproterenol in rats chronically treated with electroconvulsive shock.

Chronic electroconvulsive shock (ECS) has been shown to induce a downregulation of beta 1-adrenergic receptors in the rat cerebral cortex. Because the secretion of melatonin in the pineal gland is regulated primarily by beta 1-adrenoceptors, in the present study we investigated the effect of chronic administration of ECS on pineal beta-adrenergic responsiveness to isoproterenol. To this purpose, young adult male rats received once daily for 8 days ECS (80 mA, 0.5 s) or sham ECS. On the day after the last ECS or sham treatment, they were injected with isoproterenol hydrochloride (1 mg/kg SC) or volume-matched saline at 1600 h. Two hours later they were killed by decapitation. Results showed that the isoproterenol-induced increase in the pineal melatonin content was blunted in rats treated with ECS as compared to sham-treated animals (shock x drug interaction = p < 0.01). These data indicate that chronic ECS treatment affects beta 1 receptor-mediated melatonin production in the pineal gland. Further studies need to elucidate whether the blunted melatonin response to isoproterenol in ECS-treated rats is due to a downregulation of pinealocyte beta-adrenergic receptors.

Analysis of Variance↗

The influence of high blood levels of urea on the presence of Campylobacter pylori in the stomach: a clinical study.

In order to determine whether urea influences the presence of Campylobacter pylori (Cp) in the stomach, the incidence of this infection was determined in patients with chronic renal failure who received no treatment (group A) or underwent regular hemodialysis (group B). A third group was examined as control. Biopsies from the gastric antrum were taken for histological investigation and for Cp detection. No significant differences among the 3 groups of patients were found with regards to the incidence of Campylobacter pylori. Urea can be considered as a preferred metabolite but no proof that high levels influence the occurrence of the organism in the stomach was found.

Gastric Mucosa↗

Heat production and motor deficit in rats lesioned in globus pallidus, entopeduncular nucleus and lateral hypothalamus.

Oxygen consumption, colonic and interscapular brown adipose tissue temperature were evaluated in four groups of male and four groups of female rats both before and after lesions in different brain regions, and following beta-blocker propranolol administration. Recovery of body weight with varying difficulties in reaching food was also recorded in the injured animals. Groups consisted of rats with bilateral lesions in the entopeduncular nucleus (group EN), rats with bilateral lesions in the globus pallidus (group GP), rats with lateral hypothalamic lesions in the left side and entopeduncular lesion in the right side (group EN-LH), and rats with bilateral lesions in the lateral hypothalamus (group LH). Colonic and brown adipose tissue temperature and oxygen consumption were significantly increased after lesions in rats of groups EN, LH and EN-LH, but not in animals of the GP groups. Similarly, propranolol administration blocked the rise in heat production only in EN, LH and EN-LH animals. No differences were found between sexes. The survival rate was the same in all groups. GP rats recovered body weight earlier than animals injured in the other regions. The difficulty in reaching food was an important factor only in rats damaged in the EN. The results suggest that lateral hypothalamus and entopeduncular nucleus share a common regulatory function of the energy metabolism, while EN lesions induce a motor deficit in addition.

Adipose Tissue, Brown↗

Lack of diet-induced thermogenesis following lesions of paraventricular nucleus in rats.

The effects of electrolytic lesions in the hypothalamus paraventricular nucleus were studied in adult male and female Sprague-Dawley rats, fed different diets, consisting of either palatable human food plus chow (cafeteria diet) or chow alone. The results showed that both cafeteria diet and lesions induced an increase in energy intake and weight gain in rats of both sexes. Oxygen consumption rate and colonic temperature were significantly decreased by lesions, while cafeteria diet increased the same parameters only in intact animals. The lesion decreased weight, protein and DNA, and temperature of brown adipose tissue, while cafeteria diet increased the values considered in brown adipose tissue of sham-injured rats, but not in lesioned animals. The response to norepinephrine administration was significantly greater in intact rats and those fed cafeteria diet. The results suggest that the larger body weight gain observed in lesioned rats, particularly evident in rats fed cafeteria diet, is partly due to the disappearance of diet-induced thermogenesis that depends on the reduced mass and functional activity of brown adipose tissue.

Adipose Tissue, Brown↗

Thermogenetic changes following frontal neocortex stimulation.

Heat production changes were recorded in anesthetized female Sprague-Dawley rats after stimulation of orbital frontal neocortex. The results obtained show that orbital frontal neocortex stimulation significantly increases oxygen consumption, and core and brown adipose tissue temperature. The increase was more substantial after stimulation of left than right cortex. Administration of the beta-blocker propranolol abolished the increase in O2 consumption, core and brown adipose tissue temperature following cortical stimulation. These results are in agreement with our previous research showing that functional ablation of cerebral cortex blocked the increase in thermogenesis following lateral hypothalamic lesion. These findings also show that the orbital frontal neocortex in rats is specifically involved in the control of thermogenesis.

Adipose Tissue↗

Phase II double-blind randomized study of lonidamine and radiotherapy in epidermoid carcinoma of the lung.

Patients with non metastatic squamous cell lung cancer were treated with radiotherapy (RT) plus lonidamine (LND) or placebo (PLAC), according to a randomized double-blind study design. Treatment with lonidamine 150 mg t.i.d. (27 patients) or placebo (23 patients) started 3 days before RT, lasted up to 7 months. Partial responses were observed in 14 and 6 patients respectively in the LND + RT and PLAC + RT groups. Statistical analysis of the survival curves showed no significant difference between the LND + RT (median 311 days) and PLAC + RT (median 193 days) groups. Stage III patients survived significantly longer (p less than 0.05) when treated with LND + RT (median 318 days) than with PLAC + RT (median 163 days). No synergistic toxic effects between radiation and LND were noted. To confirm these data a new and larger multicentric study is now in progress.

Aged↗

Cortical control of thermogenesis induced by lateral hypothalamic lesion and overeating.

Increased O2 consumption was found in rats after bilateral lesions of the lateral hypothalamus (LH) or during voluntary overeating. This phenomenon appears to be mediated by the sympathetic nervous system (SNS) in both conditions, since it is blocked by the beta-blocker propranolol administration. In the first experiment we showed that the brain cortex is involved in the thermogenesis induced by LH lesion and this effect is mediated by SNS, since bilateral functional decortication induced by cortical-spreading depression (CSD) impaired the increase of O2 consumption to the same extent as administration of propranolol. In the second experiment the role played by the cerebral cortex on thermogenesis in rats during voluntary overeating of "cafeteria" diet and in control rats was investigated. Cafeteria rats showed a significantly higher colonic temperature, brown adipose tissue temperature (Tbat), and rate of O2 consumption than control animals. CSD led to a significant decrease of Tbat and O2 consumption in cafeteria rats but not in controls. On the basis of the results obtained in the two experiments, the possibility that the cerebral cortex could be involved in the metabolic responses for reduction of body weight to the "set-point" is hypothesized.

Adipose Tissue, Brown↗

[Ectrodactyly].

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Adult↗

Neophobia, conditioned taste aversion and EEG arousal after globus pallidus lesion.

Rats with unilateral or bilateral electrolytic lesions in the globus pallidus (GP) became aphagic and adipsic. Aphagia and adipsia lasted 2-3 days in rats with unilateral lesion, but were more persistent in animals with bilateral lesions. EEG arousal induced by nociceptive stimuli applied to the side of the body contralateral to the unilateral pallidal lesion was of shorter duration than that induced by ipsilateral stimulation; no difference was found between rats injured in left or right (GP). Total exploratory activity of rats with symmetrical or asymmetrical lesions, exposed to a novel environment for ten min, was not different from that of the control group, but the exploratory activity measured in a 60 sec block showed trends in the two injured groups being different than those in the controls. Rats with unilateral right or bilateral lesions showed a lower level of neophobia for saccharin than controls. Acquisition of conditioned taste aversion was similar in lesioned rats and controls, but extinction of the conditioned taste aversion was slower in the intact than in the injured animals.

Animals↗