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Biomedical subjects

L Barbara

Publications and source records attributed to L Barbara.

At least 325 records · Page 18Linked to original sources

Morphological and hemodynamic changes in the portal venous system after distal splenorenal shunt: an ultrasound and pulsed Doppler study.

We investigated a group of patients who underwent distal splenorenal shunt using high-resolution real-time equipment and a duplex scanner with the aims: (i) to evaluate the rate of visualization of shunt; (ii) to assess change in size in the portal vein, and (iii) to characterize the flow pattern in the splenic vein and to study flow direction and velocity in the portal vein, thus adding new data on the efficacy of this operation in maintaining hepatic perfusion. Real-time ultrasonography was performed in 29 patients before surgery, after 7 to 30 days and after 4 to 12 months. Direct visualization of the shunt was achieved in 53.5% of the patients. Mean caliber of the portal vein significantly decreased after the operation: preoperative = 1.52 +/- 0.32; after 7 to 30 days = 1.32 +/- 0.16 (p less than 0.001), and after 4 to 12 months = 0.99 +/- 0.19 (p less than 0.001). The overall postoperative incidence of portal thrombosis was 22.2%. Thirteen of these patients also underwent a postoperative (4 to 36 months) pulsed Doppler investigation. Flow towards anastomosis was demonstrated in the splenic vein in 11 patients, and in 7 cases, typical caval pulsatility was observed. Decreased hepatopetal flow in the portal vein was found in 10 of 13 patients. In two patients, no flow was detectable and in the other the flow was hepatofugal. On the basis of our data, we can affirm that pulsed Doppler investigation may provide useful data for the evaluation of shunt patency and preservation of a decreased portal hepatic perfusion in the majority of patients.

Adult↗

A radioimmunoassay for lithocholic acid conjugates in human serum and liver tissue.

A sensitive and specific radioimmunoassay for glycine and taurine conjugates of lithocholic acid (CLCA) has been developed. 3H-glycolithocholic acid (S.A. = 17Ci/mmol) was used as tracer. Separation of free from antibody-bound bile acid was carried out using ammonium sulphate (saturated solution). The antiserum showed high specificity for both glyco and tauro conjugated lithocholate (100% cross reaction) and lithocholic acid (25% cross reaction). The sensitivity of the assay (1 pmole/tube), was adequate for measuring CLCA in peripheral blood and hepatic tissue in man.

Antibody Specificity↗

Endoscopic ultrasonography in the diagnosis of gastric submucosal tumor.

Endoscopic ultrasonography contributed to a correct diagnosis in 24 of 25 patients with gastric submucosal tumor, including 10 extrinsic compressions and 14 intraparietal growths. Leiomyoma and lipoma were easily recognized. In one case, an unusual group of gastric varices was clearly differentiated from a pedunculated polyp prior to polypectomy. In gastric submucosal tumors, endoscopic ultrasonography can greatly reduce the need for aggressive and risky biopsy techniques or exploratory laparotomy.

Adolescent↗

Endoscopic assessment of acute inflammation of the ileal reservoir after restorative ileo-anal anastomosis.

Forty-seven patients, undergoing ileo-anal anastomosis for ulcerative colitis (42) or familial polyposis (5), were endoscopically examined after protective ileostomy or after restorative ileo-anal anastomosis. The neorectum and the ileum above were examined in all cases and multiple biopsies were taken. No symptoms of pouch inflammation were found in 41 subjects; 80.5% of these had non-macroscopic lesions and 19.5% had focal lesions such as congestion, petechiae, mucous hypersecretion (5), or single ulcers (3). None of these developed pouchitis. Pouchitis was observed in the other six subjects, who all underwent surgery for ulcerative colitis and developed 14 clinical episodes of pouchitis during the follow-up. In these cases the entire neorectum mucosa was always affected by the lesions which, in 50%, also extended to the ileum above. The most common endoscopic features (71.4%) were congestion, potechiae, oozing areas, mucous hypersecretion, and multiple superficial ulcers. In half the remaining cases (14.3%) the neorectum showed the features, described above, while the upper ileum was affected by deep round or irregular ulcers within normal mucosa; Crohn's disease was excluded in these cases. In the remaining 14.3%, pouchitis showed a pseudomembranous feature. In our experience, the endoscopic pattern of pouchitis is polymorphic. Although an ulcerative colitis-like feature prevails, pseudomembranous and Crohn's ileitis-like features may also be present.

Adenomatous Polyposis Coli↗

Assessment of portal hypertension by endoscopic ultrasonography.

Endoscopic ultrasonography (EUS) was performed in 40 patients with portal hypertension (PH) and in 48 control subjects. The azygous, splenic, mesenteric, and portal veins were displayed in both groups. However, esophageal and gastric varices, periesophageal and perigastric collateral veins, and submucosal gastric venules were displayed only in patients with portal hypertension. EUS was inferior to endoscopy in detecting and grading esophageal varices (p less than 0.0005), but EUS was superior in the detection of varices in the fundus of the stomach (p less than 0.0005). Detection of periesophageal veins by EUS increased with increasing diameter of esophageal varices at endoscopy (57% in grade 1, 89% in grade 2, and 100% in grade 3), and there was a direct correlation between endoscopic grade and the diameter of the periesophageal collateral veins at EUS. The diameter of the azygous vein by EUS at its distal and proximal margins was significantly greater in patients with PH (p less than 0.001); the EUS diameter of the azygous vein was significantly larger with variceal grade 2 compared with grade 1 (p less than 0.02 and p less than 0.01, respectively). In portal hypertensive gastropathy, endoscopic and EUS detection were coincident. No correlation was found between the presence of portal hypertensive gastropathy, endoscopic grade of esophageal varices, and detection of gastric varices at EUS.

Adult↗

Biliary surgery without the surgeon!

Since the introduction of endoscopic retrograde cholangiopancreatography in the 1970s and of endoscopic sphincterotomy (EST) in 1974, endoscopic techniques for the diagnosis and therapy of biliary and pancreatic disorders have proliferated. Although some procedures have become part of routine practice, for example EST for postcholecystectomy bile duct stones and stent insertion for inoperable biliary strictures, the place of others is unclear at present and should be evaluated by prospective randomized clinical trials. The choice of either an endoscopic or a transhepatic approach for biliary disease is usually dictated by local expertise, but these should be regarded as complementary rather than competing techniques, and complex biliary problems should be managed jointly by the endoscopist, interventional radiologist and hepatobiliary surgeon.

Acquired Immunodeficiency Syndrome↗

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↗

Optimal nutritional indexes in gastroenterology.

Malnutrition in gastrointestinal disease can result from several pathogenetic mechanisms. The resulting clinical and laboratory features of malnutrition vary according to the specific pathogenetic factors involved. Many of the causes of malnutrition in gastroenterology are similar to those found in other acute and chronic diseases. However, certain disorders, specific to gastroenterology, may alter nutritional indices independent of the usual causes of malnutrition. These include small bowel bacterial overgrowth and protein-losing enteropathy. The impact of these disorders on the indexes of nutritional status is discussed.

Gastrointestinal Diseases↗

Morphologic and cytoproliferative patterns of duodenal mucosa in two patients after long-term total parenteral nutrition: changes with oral refeeding and relation to intestinal resection.

The morphologic and cytoproliferative patterns of the duodenal mucosa of two adult patients, one of whom had a short bowel, were evaluated after more than 2 months of postoperative total parenteral nutrition and 2 and 12 months after the resumption of oral alimentation. Morphometric analysis was performed on routinely processed duodenal biopsies. Cell proliferation was evaluated by means of in vitro bromodeoxyuridine uptake. The results were compared with those obtained in five healthy controls. After parenteral nutrition, patients showed significantly lower villus height and crypt depth than those of controls and a normal bromodeoxyuridine labeling index. After 2 months of refeeding, villus and crypt returned to normal, and the labeling index was increased. After 12 months of oral refeeding, labeling index, villus height, and crypt depth were similar to those of controls. The patient with the short bowel showed a number of cells per unit length of villus and crypt significantly greater than those of the controls and of the patient who underwent shorter intestinal resection. In human duodenal mucosa, (1) hypoplasia develops after long-term total parenteral nutrition; (2) mucosal recovery occurs through an increased cell proliferation after oral refeeding; and (3) extensive small bowel resection determines the development of relative hyperplasia.

Adult↗

Bacteria in biopsies of human hypochlorhydric stomach: a scanning electron microscopy study.

A long-lasting condition of hypochloridria leads to a bacterial growth both in the gastric lumen and biopsies of human stomach. Some of these bacteria are probably involved in gastric carcinogenesis, due to their capacity of nitrosation. This study was carried out on biopsies taken during endoscopy from both gastric antrum and the body of patients with or without hypochloridria. Scanning electron microscopy observation shows that bacteria, other than Helicobacter pylori, found in hypochloridria, can be located not only over but also into and under the mucus layer covering the gastric epithelium. In such areas, mechanical and biochemical damage may occur.

Achlorhydria↗

The role of liver transplantation in the treatment of hepatocellular carcinoma.

The role of liver transplantation in the treatment of hepatocellular carcinoma (HCC) is still debated. Overall survival is poor because of the high recurrence rate. Negative prognostic factors are the presence of large, multiple lesions, lymph node involvement, gross vascular invasion and extrahepatic metastases. On the other hand a long term survival (5 yrs), can be achieved in about 30 to 48% of transplanted patients. In the case of incidental tumours, the survival rate can be as high as 90%. Fibrolamellar HCC have a better prognosis than non fibrolamellar HCC. Due to the short supply of donor livers, OLT should be offered to those patients who have the highest probability of surviving.

Carcinoma, Hepatocellular↗

Requirements for the use of intestinal action antibiotics in the treatment of ulcerative colitis.

The causes of ulcerative colitis are still unknown and above all the circumstances which can lead to inflammatory episodes are unclear. Antibiotic therapy has not provided encouraging results so far but it is possible that the pathogenesis of this disease may involve bacterial species which have not yet been identified. The use of an antibiotic with specific colic activity therefore seems to be justified.

Colitis, Ulcerative↗

Neurotensin: a physiological regulator of exocrine pancreatic secretion?

The aim of the present review was to evaluate the effects of neurotensin on the exocrine pancreatic secretion. Neurotensin immunoreactivity has been identified in the central nervous system and also in the digestive system, where it is found in specific endocrine cells of the intestinal mucosa (N cells), in nerve fibers of the enteric nervous system and in intrapancreatic ganglia (both in nerves and cell bodies). Studies in laboratory animals and in humans have demonstrated that the ingestion of a meal causes a significant release of neurotensin into the circulation and that exogenous administration of low doses of the peptide strongly stimulates exocrine pancreatic secretion. These findings, together with the demonstration that the immunoneutralization of circulating neurotensin significantly reduces the pancreatic secretory response to a meal, suggest that neurotensin is a physiological regulator of exocrine pancreatic secretion.

Animals↗

[Obesity and adipose tissue distribution in men: relation to sex steroids and insulin].

The aim of this study was to assess the correlation between the distribution of adipose tissue, sexual hormones and hyperinsulinemia in male obesity. Fifty-two obese males, aged 40.0 +/- 10.9 years old and with a body mass index (BMI) of 35.0 +/- 6.1 (m +/- SD), not suffering from diabetes or any other endocrine disease, were included in the study. A group of 20 subjects aged 30.5 +/- 7.9 (p less than 0.005 vs obese subjects) and with a BMI of 23.0 +/- 2.0 were used as controls. Body fat distribution was assessed using the waist/hip ratio (w/h ratio): 0.985 +/- 0.052 in obese subjects and 0.913 +/- 0.061 in controls (p less than 0.005). In comparison to control subjects, significantly lower levels of total (T) (357 +/- 132 vs 498 +/- 142 ng/dl; p less than 0.005) and free testosterone (FT) (14.2 +/- 2.9 vs 17.1 +/- 2.6 pg/ml; p less than 0.05) were found in the obese group, as well sex hormone binding globulin (SHBG) (41.7 +/- 31.9 vs 66.2 +/- 18.6 nmol/l; p less than 0.001). None of the other steroids (androstenedione, dehydroepiandrosterone-sulphate, estrone, 17 beta-estradiol, dihydrotestosterone) or FSH and LH gonadotropins assayed differed between the two groups. Significantly higher levels of insulin and C-peptide, both fasting and after a oral glucose tolerance test, were also found in obese subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗