[Sebaceous tumors of the eyelids in a patient with Muir-Torre syndrome]. / Tumeurs palpébrales à différenciation sébacée dans le cadre d'un syndrome de Muir-Torre.

Muir-Torre syndrome is an autosomal dominant hereditary condition predisposing to cancer. It is characterized by cutaneous tumors (such as sebaceous adenomas, epitheliomas, or carcinoma, and/or keratoacanthomas) and internal malignancies. A 47-year-old male patient with cancer antecedents consulted for two tumors of the eyelid. Histological study of the exeresis biopsies of the eyelid lesions showed a sebaceous adenoma and an epidermoid carcinoma with sebaceous differentiation. With the suspicion of Muir-Torre syndrome, a genetic consultation was requested. The geneticist found a mutation of the MSH2 gene, which was not classified as pathological. Cancer screening was begun for the patient and his descendants. The clinical outcome was death from urothelial carcinoma. Eyelid sebaceous tumors require complete medical check-up in search of carcinoma. Demonstrating Muir-Torre syndrome allows the medical team to propose early cutaneous and visceral carcinoma screening for patients, their collaterals, and their descendants.

Effects of catecholamines and their inhibitors on the isolated canine pancreas. I. Noradrenaline and isoprenaline.

alpha Adrenergic agonist (noradrenaline, 2, 20, and 200 mug) and antagonist (phenoxybenzamine, 15 mg), and beta adrenergic agonist (isoproterenol, 2, 20, and 200 mug), and antagonist (propranolol, 6 mg), were tested on isolated perfused canine pancreas under basal conditions, and under stimulation by a background of secretin (0.5 clinical unit per hr), or of caerulein (600 to 1200 ng per hr). Noradrenaline induced a strong vasoconstriction (inhibited by phenoxybenzamine), followed by a moderate vasodilation (possibly mechanical). Noradrenaline did not stimulate a resting pancreas and inhibited a pancreas from secreting in response to secretin or caerulein. After phenoxybenzamine, in the absence of vasoconstriction, this latter effect was reversed into a dose-dependent stimulation of hydrelatic secretion, suggesting that noradrenaline had a direct action on the secretory cell. There was no stimulation of protein and no acinar degranulation. Propranolol and atropine did not modify the effectiveness of noradrenaline. Isoprenaline had a weak vasodilatory effect but no effect on the secretion. Adrenergic blocking agents did not alter the response to secretin or caerulein.

Respiratory exchanges and acid-base balance during perfusion of ex vivo isolated pancreas.

We used the technique of ex vivo isolated pancreas, perfused with whole heparinized blood. The organ was stimulated by secretin (G.I.H. Stockolm, 0.1-5.0 clinic units/hr), and/or carbamylcholine (100-200 mug/hr). Oxygen consumption was increased under stimulation. This increase was a function of the dose of secretin and also of the bicarbonate output in the juice. Oxygen uptake increased further when carbamylcholine was super-imposed on secretin. This extra increase was independent of hemodynamic conditions of the organ perfusion. Arteriovenous difference in oxygen saturation did not increase when the gland was stimulated. It tended to decrease when the stimulation resulted in a marked vasodilatation. Thus, oxygen needs seemed to be neither the limiting factor of the response to a given stimulation nor the triggering mechanism of functional vasodilatation. Values of pCO2 were spread over a wide range from one experiment to another. However, it could be observed that CO2 efflux into the vein decreased under stimulation by secretin; in most experiments, CO2 efflux was even replaced by an apparent consumption of CO2 during the perfusion of the stimulated gland. Furthermore, arteriovenous pH difference increased following secretin stimulation. This increase was dose-related to secretin. These facts are discussed under the background of theories recently proposed for bicarbonate secretion.

Role of cholinergic mechanisms in the response to secretin of isolated canine pancreas.

The effects of carbamylcholine (CCH, 100 mug per hr) and of atropine (0.25, 1.0, and 10.0 mg per hr) on the response of the exocrine pancreas to secretin (0.1, 0.5, and 5.0 clinic units per hr) were studied using the isolated canine pancreas perfused with whole heparin-treated blood. CCH induced a sharp decrease in D50 (dose of secretin which elicits half the calculated maximal response) but no increase in maximal response to secretin. Experiments performed under different haemodynamic conditions show that this potentiating effect (synergism) is partly due to vasomotor modifications and chiefly to the action of CCH on the receptor of secretin. Although this work indicates that cholinergic tone is not necessary for secretin-induced hydrelatic response to occur, it evidences that this cholinergic tone plays a major role in modulating the pancreatic response to submaximal doses of secretin. It has also been found that large doses of atropine (10 mg per hr) were necessary to achieve a complete inhibition of enzymatic response to CCH. Even at these high doses, however, enzymatic response to secretin and cholecystokinin-pancreozymin were not significantly inhibited.