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Biomedical subjects

F Lami

Publications and source records attributed to F Lami.

15 recordsLinked to original sources

Heparin prevents stasis-induced thrombosis through protection of the venous endothelial cells: an electron microscopic study in rabbits.

This study was performed to see whether or not protection of the endothelial cells contributes to the antithrombotic effects of heparin. New Zealand albino rabbits were subjected to jugular vein stasis by single caudal ligation for 2 h. Three treatments were given: saline (control group), heparin (0.2 mg/kg) 5 or 45 min before ligature of the vein. Groups of 6-8 animals were killed at 0, 5, 15, 30 and 120 min. The following parameters were determined: (1) involution and damage of the endothelial cells by scanning and transmission electron microscopy; (2) incidence and weight of thrombi in the lumens of the veins after 2 h stasis, and (3) effects of heparin on APTT and anti-Xa activity. In the control group, stasis caused a considerable involution of the endothelial cells in the first 30 min, followed by fibrin deposition and thrombus generation. Heparin strongly reduced the damage to the endothelial cells, with very evident protection of the cell membranes, and prevented thrombus generation: there were significant decreases in both incidence and weight of thrombi. These effects of heparin were evident both shortly after (maximal anticoagulant effect) and long after (no anticoagulant effect) pretreatment. We think that, under the experimental conditions we used, heparin prevented venous thrombosis at least partially by protection of the endothelial cells, through unknown mechanisms.

Animals

Efficacy of addition of exogenous lactase to milk in adult lactase deficiency.

The efficacy of lactase by Kluyveromyces lactis in hydrolyzing milk lactose and reducing milk intolerance symptoms was tested in 52 proved lactose malabsorbers. The enzyme was added to milk administered to the patients, and H2 breath excretion (as an index of carbohydrate malabsorption), was determined by gas chromatograph technique, and milk intolerance symptoms were recorded. H2 mean excretion was 78.3 +/- 5.49 ppm after administration of intact whole milk 500 ml (test A), 43.5 +/- 4.99 ppm when lactase 2000 U was added to milk 500 ml immediately before administration (test B); 36.7 +/- 5.01 ppm when milk 500 ml was incubated for 12 h with lactase 1000 U (test C), and 29.7 +/- 4.35 ppm when the incubation was prolonged for 24 h (test D). Symptoms score was: test A = 5.85 +/- 0.56, test B = 3.71 +/- 0.45, test C = 2.77 +/- 0.63, test D = 1.7 +/- 0.68. A correlation index of r = 0.44 (p less than 0.01) was obtained between reduction in H2 mean excretion and reduction in symptoms score of a single individual. The addition of this lactase to milk seems to be effective in correcting lactose malabsorption, thus representing a convenient approach in milk intolerance.

Adult

Lactose malabsorption in adult patients with Crohn's disease.

In order to evaluate, in adult patients with Crohn's disease (CD), the prevalence of lactose malabsorption and intolerance, and the percentage who can tolerate a physiologic amount of milk in their diet, we tested 37 patients with CD (19 with intestinal resection, and 18 without) and 67 healthy controls (C) with the H2-breath test after they had ingested increasing loads of lactose as 10% solution (12.5 g, 25 g, and 50 g). Patients with malabsorption after the 12.5-g dose were tested further with 250 ml of milk. In the total group of patients and in the subgroup of those with resection, the prevalence of malabsorption was higher than in controls at all lactose loads; in patients who had not undergone resection, no significant difference was observed with the 12.5-g dose. Eleven of 18 patients who were malabsorbers with the 12.5-g dose had malabsorption also with 250 ml milk; however, only three of them (8% of the total group) experienced symptoms of intolerance. We conclude that, in adult patients with CD, 1) the prevalence of lactose malabsorption is increased, 2) in patients who have undergone intestinal resection, malabsorption occurs at a lower dose of the sugar than in patients who did not, and 3) since only 8% of patients experienced symptoms of intolerance after the ingestion of milk 250 ml, this amount can be empirically inserted in the daily diet of an adult with CD.

Adolescent

A single-specimen fecal chymotrypsin test in the diagnosis of pancreatic insufficiency: correlation with secretin-cholecystokinin and NBT-PABA tests.

An investigation of fecal chymotrypsin activity on spot fecal specimens was carried out in three groups of subjects, divided as follows: 45 healthy controls (group C); 36 patients with gastroenterological diseases of extrapancreatic origin (group VP); and 42 patients with chronic pancreatitis (group CP). Nineteen patients of group CP underwent pancreozymin-secretin and NBT-PABA tests. The following results, expressed as mg of chymotrypsin/g of feces, were obtained: C = 0.610 +/- 0.203; CP = 0.291 +/- 0.154, p less than 0.001; VP = 0.560 +/- 0.234. FCT showed a sensitivity rate of 78.5% and a specificity rate of 71.6%. The fecal output of chymotrypsin correlated well with the pancreatic secretion of chymotrypsin (r = 0.59, p less than 0.01) and with the percentage of recovery of urinary PABA (r = 0.44, p less than 0.05). We conclude that chymotrypsin assay by the described method on spot stool specimens is a simple, reliable technique which may be considered a good screening test for pancreatic insufficiency. The test will not detect minimal pancreatic disease or minimal pancreatic dysfunction.

4-Aminobenzoic Acid

Intestinal morphological changes during oral refeeding in a patient previously treated with total parenteral nutrition for small bowel resection.

This report describes a patient who, after a subtotal resection of small intestine for an embolic obstruction of the superior mesenteric artery, was maintained on total parenteral nutrition for 30 days and then refed. Cytoproliferative analysis of the intestinal mucosa, evaluated by peroral biopsies performed on days 1, 5, 14 and 30 after oral refeeding, demonstrated an increase in cell proliferation from 1 to 14 days after refeeding, followed by a return to starting values after 30 days. On days 1 and 5, we saw an intestinal hypoplasia that became a hyperplasia after 14 days of oral refeeding. Our data confirm the importance of oral nutrition for the small intestinal response after resection.

Aged

Effect of chemically defined formula diets on pancreatic mass in the rat.

To establish the effect of chemically defined formula diets on pancreatic mass, 58 male Wistar rats, weighing approximately 200 g, were fed orally one of the following diets for 20 days: standard diet; partially hydrolyzed diet; elemental diet. The diets were isocaloric and provided 73 cal/day per rat. At the end of the experiment, the rats were killed and pancreas removed to assess wet weight and DNA and RNA content. Compared to the controls, the elemental diet caused a reduction in pancreatic wet weight (p less than 0.005), pancreatic DNA (p less than 0.001), and RNA content (p less than 0.001). In the group fed partially hydrolyzed diet, only pancreatic DNA content showed an highly significant reduction when compared with the reference group (p less than 0.001), whereas the value of RNA failed to reach the statistical significance. We found an increase of the ratio mg RNA/mg DNA in the partially hydrolyzed and elemental diet groups. These results suggest that long-term nutrition with the partially hydrolyzed diet, and more strongly with the elemental diet, may induce pancreatic hypoplasia.

Animals