Publications by authors named "Giorgio R"

In the pancreas, calcitonin gene-related peptide (CGRP) immunoreactivity has been described in nerve fibers and in distinct types of islet cells. This unique, apparently species-specific cell-type expression prompted the present investigation to clarify further the pattern of CGRP immunoreactivity in different mammalian species (i.e.

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The differentiation of human peripheral blood monocytes (HPBM) into macrophages, when cultured in vitro, has been associated with an increase in the expression of tissue transglutaminase (TGc). Retinoic acid (RA) addition to 5-day-old cultured monocytes, 36 h later induced about 5-folds increase of TGc content. The preliminary exposure of cultured monocytes to alpha-difluoromethylornithine (DFMO) significantly reduced TGc induction caused by RA.

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The aim of the present review was to evaluate the effects of neurotensin on the exocrine pancreatic secretion. Neurotensin immunoreactivity has been identified in the central nervous system and also in the digestive system, where it is found in specific endocrine cells of the intestinal mucosa (N cells), in nerve fibers of the enteric nervous system and in intrapancreatic ganglia (both in nerves and cell bodies). Studies in laboratory animals and in humans have demonstrated that the ingestion of a meal causes a significant release of neurotensin into the circulation and that exogenous administration of low doses of the peptide strongly stimulates exocrine pancreatic secretion.

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The effects of taurine supplementation on GABA-related amino acid homeostasis in developing nervous tissues of suckling rats were studied. In the first two weeks of postnatal growth, cerebral cortex and cerebellum appear more accessible to taurine supplementation in comparison to retina; in addition, different changes in excitatory/inhibitory amino acids were observed. After the 5th day of life, in the retina and cerebellum of taurine-supplemented pups a decrease in GABA levels was found; in contrast, in cerebral cortex GABA content significantly increased throughout 20 days of postnatal growth.

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A 43-year-old man with chronic intestinal pseudo-obstruction is presented. He had undergone two laparotomies in an attempt to eliminate the cause of repeated episodes suggestive of obstruction. Gastrointestinal manometry showed severe abnormalities compatible with the diagnosis of chronic intestinal pseudo-obstruction.

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In this study, we performed a detailed analysis of the immunoreactive (IR) patterns and tissue distribution of vasoactive intestinal polypeptide (VIP), neuropeptide Y (NPY), and gastrin-releasing peptide (GRP) in the feline pancreas by means of immunohistochemical and radioimmunological techniques. Immunoreactivity for each peptide is localized to varicose nerve fibers distributed throughout the exocrine and endocrine pancreas, with some differences in the density and pattern of fiber distribution. In the acinar and stromal compartments, VIP-IR processes have a higher density than NPY- and GRP-containing fibers, the latter being the least abundant.

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The distribution of calcitonin gene-related peptide (CGRP), substance P/tachykinin (SP/TK), vasoactive intestinal polypeptide (VIP), neuropeptide Y (NPY) and gastrin-releasing peptide (GRP) immunreactivities (IR) in the rat pancreas was investigated using radioimmunoassay and immunohistochemistry. CGRP, NPY and VIP tissue contents are much higher than GRP and SP/TK concentrations. Peptide-containing nerves are distributed to both the exocrine and endocrine pancreas.

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A rare case of pancreatic exocrine carcinoma with an endocrine component secreting adrenocorticotropic hormone (ACTH) is reported and discussed in relation to other cases previously published. The patient initially presented with a severe form of diabetes, which was treated accordingly. Persistence of hyperglycemia, along with other metabolic alterations and marked hypokalemia, led to the suggestion of abnormal ACTH secretion.

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We report a case of primary esophageal non-Hodgkin's T-cell lymphoma in a young white female. At admission, endoscopy revealed large, irregularly shaped, esophageal ulcerations with super imposed candidiasis. Endoscopic ultrasonography to assess submucosal alterations and periesophageal involvement revealed a diffuse hypoechogenic thickening (up to 5 mm) of the esophageal wall, a pattern consistent with lymphomatous infiltration.

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A case of single, polypoid metastatic malignant melanoma of the gallbladder is described. The differential diagnosis with primary malignant melanoma and undifferentiated carcinoma is discussed.

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The effect of glucocorticoids on polyamine metabolism has been elucidated further by measuring putrescine, spermidine, and spermine levels as well as ornithine decarboxylase, S-adenosylmethionine decarboxylase, and N1-acetylspermidine transferase activities in the hippocampus, cerebellar cortex, vermis, and deep nuclei of adrenalectomized rats. At 6 h after corticosterone or dexamethasone administration, the specific activities of ornithine decarboxylase and N1-acetylspermidine transferase showed the greatest increases in all brain tissues examined, and at 12 h, S-adenosylmethionine decarboxylase activity was not increased significantly. The hippocampus and cerebellar regions displayed different responses to corticosterone and dexamethasone, corresponding to the distribution of glucocorticoid and mineralocorticoid receptors.

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Aerobic and hemodynamic performance, at rest and during exercise, has been explored in patients with either atrial synchronous ventricular or respiratory-dependent ventricular pacing. In patients with chronic AV block and normal left ventricle, the cardiac output, VO2 at maximal exercise, and work tolerance increased significantly with rate-responsive pacing in comparison with fixed ventricular pacing. Chronic AV block and left ventricle dysfunction in patients with respiratory-dependent ventricular pacing improved maximal cardiac output, VO2 anaerobic threshold, and physical work capacity.

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Repeated but not single injections of estradiol benzoate significantly reduced nigral glutamic acid decarboxylase (GAD, EC 4.1.1.

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Effects of intraventricularly injected spermine on behavior and electrocortical activity and gamma-aminobutyric acid (GABA) metabolism after a single dose of 1.13 mumol/animal were studied. Decrease in locomotor activity, sedation or sleep, and electrocortical synchronization that lasted approximately 2 h were observed.

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To elucidate T(4) metabolism in various cell types of rat retina, 5-monodeiodinating and 5?-monodeiodinating activities were studied in retinal cell layers obtained by selective cytotoxic action of monosodium glutamate on bipolar and ganglion cell layers and by iodoacetate effect on photoreceptor cells. Concomitantly these enzyme activities were studied in C3H/HeN mouse retina genetically deprived of photoreceptor cells. Deiodinase activities were low in rat and mouse retina deprived of photoreceptors.

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Subcutaneous administration of high doses of glutamate to rats during their first 10 days after birth produced a great reduction of GABA content and GAD activity in the adult mediobasal hypothalamus, both in male and female. In addition GABA content and GAD activity showed a slight significant decrease in female cerebellum and male striatum. Glutamate treatment was also followed by a significant increase in GABA content and GAD activity of male substantia nigra, cerebellum, hippocampus and of female olfactory bulb.

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The temporal sequence of electrophysiological and biochemical correlates of epilepsy induced by systemic injection of kainic acid (15 mg/kg i.p.) was investigated in male rats.

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The effects of subcutaneous daily treatment with thyroxine on cell proliferation, differentiation, polyamines, and gamma-aminobutyric acid metabolism in the rat retina were studied during the first 20 postnatal days. The retinal layers of the treated rats displayed an enhanced cell differentiation which reached its maximum 9-12 days from birth; but this effect stopped very quickly and was finished by the 20th postnatal day. Primarily there was an increase in ornithine decarboxylase activity which was accompanied by an increase in putrescine, spermidine, and spermine levels.

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To elucidate tetraiodothyronine (T4) metabolism in developing rat retina 5-monodeiodinating and 5'-monodeiodinating activities were studied. T4 was incubated with aliquots of homogenate or crude primary subcellular fractions, and the 3,3',5'-triiodothyronine (rT3) or 3,5,3'-triiodothyronine (T3) produced were measured by radioimmunoassay. Reaction rates were dependent on incubation time, tissue amount, temperature and pH.

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Cerebral glutamate decarboxylase (GAD) activity in DOCA-salt hypertensive rats showed a significant increase in the mesencephalon and a significant decrease in the cerebral cortex and in the cerebellum, compared to that observed in mononephrectomized normotensive animals. Intracerebroventricular (icv) injection of muscimol (0.5, 1 and 2 micrograms), a GABA receptor agonist, produced a dose-dependent decrease in heart rate (HR), significantly greater in freely moving hypertensive animals than in normotensive controls.

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