[Preservation of hepatocytes of the rat by active transport of glycine].

The measurement of the active accumulation of specific substrates against a concentration gradient in tissue fragments in vitro has proved to be a simple but excellent procedure to ascertain the viability of several cell types and, in parallel with routine microscopy, has become a reliable tool in assaying the biochemical and functional modifications of a tissue under physiopathological conditions. It also has the added advantage of using tissues that are not pretreated in any way such as the preparative procedures used in cell isolation methods. The majority of investigations employing hepatocytes has been carried out in material derived from cell cultures or on isolated cells in suspension.

[Value of antral mucosectomy, selective proximal vagotomy and a combination of the 2 procedures in serum gastrin production and inhibition of stomach acid. An experimental study].

This experimental study was aimed at determining the volume and acidity produced by the normal stomach, following antral mucosectomy (MA), proximal selective vagotomy (VSP) and combination of both procedures. In 10 mongrel dogs, a double-lumen tube was placed in the stomach under general anesthesia. One of the lumen was rinsed with a constant flow and the other retrieved the gastric secretion.

[An evaluation method for organ preservation].

The determination of the active transport of alanine by canine endothelial cells was employed as a parameter to test cellular viability following conservation in vitro at 4 degrees C in Krebs bicarbonate buffer (KB), St. Thomas (ST), Euro-Collins (EC) or University of Wisconsin (UW) solutions. Following 24-hour conservation, active transport values demonstrated that the highest results were obtained with UW solution.

[Development of a gastroplasty with variable diameter. Experimental study using artificial sphincters].

The vertical banded gastroplasty is currently the most popular technique in the surgical treatment of morbid obesity. This experimental study was aimed to create a gastroplasty with a variable stoma. The Marlex band was replaced by the cuff of an artificial sphincter to allow selective variation of the diameter of the stoma.

Alanine uptake by the endothelium of canine blood vessels and by the vessels of human umbilical cord.

In order to determine whether the endothelium of vascular wall fragments possesses an active uptake mechanism for alanine identical to the one present in endothelial cells in tissue culture samples of canine aorta, carotid artery and vena cava, human umbilical cord vessels, were incubated in vitro in the presence of labelled alanine. In a series of experiments, it was observed that all the tissues investigated accumulated a significant amount of this substrate against a concentration gradient, and that the accumulation was saturable in the presence of sodium. This uptake was sodium-dependent, was significantly inhibited by ouabain and was greatly reduced under anoxic conditions.

[Origin of secretions after denervation of the small intestine in the dog].

The origin of the severe diarrhea appearing after intestinal denervation or transplantation was studied on the 3rd and 14th postoperative days in 5 groups of dogs undergoing total or partial denervation. The net movements of water and electrolytes were investigated by employing an experimental model of intestinal perfusion in isolated loops in vivo. The active uptake of phenylalanine and beta-methylglucoside and Na(+)-K(+)-ATPase activity were used for in-vitro evaluation.

Active uptake of amino acids by the urinary bladder epithelium of rat, rabbit, and dog.

Through a series of experiments employing tissue fragments incubated in vitro together with labeled substrates, it was observed that the tight urinary bladder epithelia of rat, rabbit, and dog possess the capacity of an active accumulation of amino acids against a concentration gradient. This uptake is saturable in the presence of sodium, is sodium-dependent, and is inhibited by ouabain. In comparison with other tissues, this phenomenon of active uptake is strikingly resistant to anoxia.

Recombinant human interleukin-1 beta decreases serum carboxypeptidase N and modifies serum amino acid concentrations in rats.

The effects of recombinant human interleukin-1 beta (rhIL-1 beta) on various serum constituents were studied following subcutaneous injection (12.5 or 125 micrograms/kg) in female Wistar rats. Protein electrophoresis and the determination of the serum concentrations of carboxypeptidase N (CPN), aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, aldolase, total proteins, iron, urea, creatinine, and several amino acids were performed 12, 24, and 72 hr after injection.

Prevention of coronary restenosis by stenting.

Balloon angioplasty fails to provide acceptable long-term results for a significant proportion of patients. An intravascular mechanical support, developed with the aim of preventing restenosis and acute closure of diseased arteries after transluminal angioplasty, was implanted in 44 patients (39 male and five female), aged from 35 to 70 years (mean 56 years) with documented restenosis of native coronary artery (41 stents) and bypass grafts (12 stents). In the group of bypass graft patients there was no local restenosis and no major complication.

Intravascular stents to prevent occlusion and restenosis after transluminal angioplasty.

Occlusion and restenosis are the most common reasons that transluminal balloon angioplasty may fail to provide long-term benefit. An intravascular mechanical support was therefore developed with the aim of preventing restenosis and sudden closure of diseased arteries after angioplasty. The endoprosthesis consists of a self-expandable stainless-steel mesh that can be implanted nonsurgically in the coronary or peripheral arteries.

Effect of dimethyl sulfoxide on the function and structure of the intact and ischemic canine ileum.

The action of dimethyl sulfoxide (DMSO) was investigated employing an experimental model of intestinal perfusion in vivo of isolated loops of dog ileum before, during, and following 1-h ischemia. DMSO was administered either into the intestinal lumen or by a continuous injection via a branch of the artery supplying the experimental loop. In the intact intestine, intraluminal DMSO significantly decreased the net movement of water, electrolytes, and glucose without affecting either the active transport of phenylalanine and beta-methylglucoside or morphology.

A long-term study of different types of experimental alkaline reflux and the effects of its suppression in dogs.

The gastric mucosa of 19 mongrel dogs was submitted to a bilio-pancreatic, isolated biliary or isolated pancreatic reflux. With an isolated biliary reflux, there is a more rapid and more severe hyperaemia and foveolar hyperplasia of the mucosa of the fundus than with an isolated pancreatic reflux. There was no significant change in the basal serum level of gastrin with any of these different types of alkaline reflux, but we observed a statistically significant increase in the level of histamine in the gastric mucosa.

A long-term study of experimental duodenogastric reflux on the vagotomized stomach in dogs.

The possibility has been explored in dogs that the effects of chronic enteral reflux on the gastric mucosa may be modified by highly selective vagotomy (HSV). In both the innervated and the vagotomized stomachs, Roux-en-Y duodenogastrostomy induced mucosal hyperaemia and foveolar hyperplasia; the mucosa regained normal morphology after the elimination of reflux. Duodenogastrostomy without HSV did not influence basal serum gastrin but resulted in a significant increase in mucosal histamine.

Functional alterations in the dog colon mucosa following temporary ischaemia.

Segments of dog colon were subjected to 1 h of total ischaemia. In one experimental group, the colon was not touched before the trauma; in another, it was rinsed out before the intervention; while in a third, it was perfused with Krebs bicarbonate buffer during injury. In all groups, the mucosa after the trauma is the site of net movement of water, sodium and chloride towards the lumen, while glucose absorption is greatly reduced.