Publications by authors named "Chayvialle J"

The effects of synthetic cyclic somatostatin 14 were studied in two patients with the carcinoid syndrome. The 3-hour intravenous administration of somatostatin (250 micrograms X h-1), a) resulted in the disappearance of flushing in the first patient but was without any clinical effect in the second subject who remained chronically colored; b) lowered plasma levels of motilin, prostaglandins (E1, E2 and F2 alpha) and to a lesser extent of catecholamines in both patients whereas the serotonin level was not altered; c) was followed by a rebound effect with recurrence of severe flushing in the first patient and was associated with a dramatic increase of prostaglandin, substance P and catecholamine levels in both patients. The inhibitory effect of somatostatin and the occurrence of a rebound effect at the end of infusion were confirmed by infusing somatostatin (6 mg per day) during 48 h in the first patients.

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The distribution of substance P (SP) in human anencephalic fetus spinal cord has been studied with the indirect immunofluorescence technique. The SP-like immunoreactivity was detected within plexuses of fibres localized in the superficial layers of the dorsal grey including the marginal zone and substantia gelatinosa, and also the dorsal funicular grey. The other spinal cord areas were devoid of SP-like immunoreactivity.

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Using the indirect immunofluorescence method, the distribution of substance P-like-immunoreactivity was studied in spinal cord and dorsal root ganglia of 25 human foetuses ranging from 12 to 29 weeks of gestational age. The spinal cord and dorsal root ganglia of three infants (1 day-, 2 and 4 month-old) were also investigated as a post-natal reference. On the whole, the substance P distribution patterns seen in infants were already visible throughout most of foetal life.

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The possibility that somatostatin 14 (SRIF) may exert true endocrine actions in man was tested by investigating the hormonal and metabolic effects of the peptide infused for 80 min at rates of 36.5, 73, and 146 pmol kg-1 h-1 in six healthy subjects who fasted overnight. These three doses increased the level of plasma SRIF-like immunoreactivity in the range of concentrations recorded postprandially with the same assay system.

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The distribution of tyrosine hydroxylase-, substance P- and enkephalin-immunoreactive neurons in the cat dorsolateral pons was studied using the indirect immunofluorescence method of Coons. To allow for the visualization of substance P- and enkephalin-immunoreactive cell bodies, colchicine was injected either in the ventricular space or in the cerebral tissue. The distribution of the tyrosine hydroxylase-immunoreactive cell bodies corresponded with the well-known distribution of catecholamine cells in this area of the brain.

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Immunocytochemistry and radioimmunoassay were used to assess the appearance time and tissue distribution of vasoactive intestinal peptide (VIP) in the digestive tract of the human fetus. By radioimmunoassay, VIP was measurable from 10 weeks of gestation. The peptide was abundantly distributed in the jejuno-ileum and colon, where the tissue peptide concentration rose from 9-14 weeks of gestation (18.

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The effects of intraduodenal glucose infusions on pancreatic exocrine secretion were studied in anesthetized and in conscious rats with pancreatic fistula. In the anesthetized model a stimulating effect of glucose on pancreatic flow and bicarbonate output was evidenced. This effect was dose-related and depended in part upon osmolarity of the solution.

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In exceptional cases, acromegaly develops as the clinical expression of an ectopic secretion of Growth Hormone (GH) or Growth Hormone-Releasing Factor (GRF), tumorous in origin. In the present report, we describe an instance of acromegaly caused by the secretion of GRF from a voluminous pancreatic tumor. The resection of this tumor resulted in a temporary disappearance of the biological and clinical symptoms of acromegaly, which then reappeared in conjunction with a rise in plasma GRF.

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Plasma somatostatin concentration was measured by radioimmunoassay in 26 preterm neonates (mean gestational age 34 weeks). None were seriously ill and they were all fed with breast-milk 12 h after birth. In a longitudinal study the concentrations were (mean +/- SEM): 21 +/- 2 pmol/l (n = 8) at 2-8 h of age, 24 +/- 2 pmol/l (n = 11) at the age of 2 days and 25 +/- 2 pmol/l (n = 15) at the age of 8 days.

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The effects of porcine vasoactive intestinal peptide on the acid and pepsin secretions from denervated gastric pouches and innervated stomach were studied in conscious cats both in basal conditions and after stimulation with pentagastrin, histamine, or a liver meal. In contrast with the well-known inhibitory effect of vasoactive intestinal peptide on acid and pepsin secretions in dogs, the peptide induced in cats an increase of the acid and pepsin responses to pentagastrin and an increase of the gastric mucosal blood flow as determined by aminopyrine clearance. Vasoactive intestinal peptide similarly enhanced the acid and pepsin responses to a liver meal in spite of a significant inhibition of the postprandial release of gastrin.

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The effects of somatostatin on diarrhea and on small intestinal flow of water and electrolytes (slow-marker perfusion technique) in a patient with pancreatic cholera are reported. Continuous intravenous infusion of somatostatin (8 micrograms/kg/hr) suppressed the diarrhea, but a rebound was observed after somatostatin. Infusion of somatostatin at the same dosage decreased the ileal fluid flow rate to within control values.

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The effect of somatostatin 14 on gastric stimulation produced by secretin was determined in 6 conscious cats equipped with a gastric fistula and a denervated fundic pouch. Somatostatin strongly inhibited the basal and secretin-induced pepsin secretion. It did not, however, inhibit the secretin-induced mucus secretion, even though it decreased the basal mucus secretion.

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The effect of bombesin on acid and pepsin secretion and antral motility was compared to that of pentagastrin in conscious cats. Bombesin stimulated acid secretion to 65% of the maximal response to pentagastrin but induced a stronger pepsin secretion than any dose of pentagastrin. As to antral motility, bombesin first induced an effect comparable to that of pentagastrin, with an increase of low-amplitude and a decrease of high-amplitude contractions.

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A case of pancreatic cholera (Verner-Morrison syndrome) associated with a pancreatic endocrine tumor and hepatic metastases is presented. VIP and HPP plasma levels, initially elevated, were accurately followed in various conditions: during corticosteroid therapy, after pancreatic tumor excision, during and after streptozotocin therapy (1.5 g/m2) by repeated intraarterial route).

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Substance P (SP) is known to act on pituitary hormone release either at the hypothalamic level or directly at the pituitary level. In order to investigate whether SP is present in the pituitary gland and to localize the peptide at the cellular and subcellular levels, the immunocytological method was used. Rat pituitaries were fixed and frozen.

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The effects of hepatic transit on concentrations of synthetic cyclic (ovine) somatostatin and of highly purified (porcine) vasoactive intestinal peptide were studied in five conscious dogs prepared with indwelling portal catheters. The peptides were infused via peripheral vein catheters or the portal catheters for 40 minutes at actual integrated doses of 2.8 pmol/kg/min for vasoactive intestinal peptide an 8.

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The effects of somatostatin-14 (S14) and somatostatin-28 (S28), a novel intestinal peptide containing somatostatin tetradecapeptide in its C-terminal position, on the bombesin-stimulated release of gastrin, insulin, and glucagon were tested. On iv infusion of bombesin, the increase in the level of glucagon was seen to be twice that of gastrin, and the insulin increase was 8 times that of gastrin. Plasma concentrations of somatostatin were not modified.

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We have studied in seven men, consuming less than 50 g alcohol daily, the effect of intravenous (i.v.) ethanol on (a) hormonally (secretin + CCK PZ) submaximally stimulated pancreatic secretion and (b) blood levels of pancreatic polypeptide (PP), vasoactive intestinal peptide (VIP) and somatostatin.

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