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Reg protein was first found in pancreatic stones. It was named Pancreatic Stone Protein and later renamed lithostathine, as it was assumed to prevent stone formation. The 144 amino acid protein is O-glycosylated on Thr-5. The glycan chain is variable in length and in charge. Lithostathine 3-D organization is of the C-lectin type, even though it is unlikely to have any functional calcium-binding site. The Arg11-Ile12 bond is readily cleaved by trypsin; the resulting C-terminal polypeptide precipitates at physiological pH and tends to form fibrils. The protein was more recently found in the regenerating endocrine pancreas and it was named Reg (for regenerating) protein. Numerous proteins related to Reg have been identified successively in several mammalian species. They constitute the Reg superfamily. Reg genes show the same organization and are located in the same chromosome region. These genes are therefore likely to derive from a common ancestor gene by duplication. In the course of evolution, they may have diverged in tissue-related expression and function. In the endocrine pancreas, Reg protein stimulates islet beta-cell growth and reduces experimental diabetes via the activation of a high affinity receptor. The role of the protein produced by the exocrine pancreas, however, is controversial. Not only is Reg/lithostathine unlikely to be a physiologically relevant pancreatic stone inhibitor, but it may contribute to stone formation. We suggest that it might help prevent the harmful activation of protease precursors in the pancreatic juice. The protein provides a useful model for examining the conformational changes associated with globular to fibril transformation.

The diagnosis of near total occlusion of the internal carotid artery was made on a group of 122 patients (90 symptomatic - 32 asymptomatic) by Doppler examination on one hand and carotid phonoangiography and oculoplethysmography, used together, on the other hand. The angiographic examination, including the study of the extra cranial arteries and the intra cerebral vessels, was performed. It has shown that a stenosis (greater than or equal to 90% of an internal carotid artery was the only lesion on 65 patients (53.3%) and that in 57 cases (46.7%) there were multiple lesions. 96 patients (76 symptomatic - 20 asymptomatic) were operated on. 4 patients (4.2%) died but the mortality was none in the group of 20 asymptomatic patients. 19 patients refused the operation and we have noted 7 occlusions of the internal carotid artery and 2 patients died (10.2%). On 7 patients with a surgical contra indication we have noted 1 secondary occlusion. We have to consider a near total occlusion of the internal carotid artery as an emergency. Its diagnosis by non invasive techniques must be followed by heparin therapy and angiographic examination. The carotid endarterectomy will respect the external carotid artery patency.

• Intraoperative arteriography was carried out using a specially constructed operating table and long x-ray film changer that permitted rapid serial exposure of the arterial reconstruction and the distal arteries. During a ten-year period, this method was applied in 1,810 arterial reconstructions, with technical problems being detected in 82 (4.6%) of these patients. The incidence of problems was highest in patients undergoing endarterectomy, where 16.7% of the patients were found to have either residual debris in the cleared segment or areas of stenosis. When bypass grafts were used, technical problems were found in 2.2% of patients and included embolism or thrombosis, graft torsion in vein grafts, stenosis of the distal anastomosis, and the creation of an intimal flap. In the entire series, five patients needed reoperation in the early postoperative period. In three of these, the operative arteriograms had been initially misread. (Arch Surg112:1115-1118, 1977)

Recent research studies have shown that the intra-skeletal organic matrix of corals contains lipids. This communication reports their characterization and their influence on calcium carbonate precipitation. In addition, their potential role in coral's biomineralization is discussed.

Anthropogenic CO2 is a major driver of current environmental change in most ecosystems1, and the related ocean acidification (OA) is threatening marine biota2. With increasing pCO2, calcification rates of several species decrease3, although cases of up-regulation are observed4. Here, we show that biological control over mineralization relates to species abundance along a natural pH gradient. As pCO2 increased, the mineralogy of a scleractinian coral (Balanophyllia europaea) and a mollusc (Vermetus triqueter) did not change. In contrast, two calcifying algae (Padina pavonica and Acetabularia acetabulum) reduced and changed mineralization with increasing pCO2, from aragonite to the less soluble calcium sulphates and whewellite, respectively. As pCO2 increased, the coral and mollusc abundance was severely reduced, with both species disappearing at pH < 7.8. Conversely, the two calcifying and a non-calcifying algae (Lobophora variegata) showed less severe or no reductions with increasing pCO2, and were all found at the lowest pH site. The mineralization response to decreasing pH suggests a link with the degree of control over the biomineralization process by the organism, as only species with lower control managed to thrive in the lowest pH.