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Biomedical subjects

I Bjarnason

Publications and source records attributed to I Bjarnason.

At least 91 records · Page 5Linked to original sources
PubMed1995

Alterations in nutritional status and disease activity during treatment of Crohn's disease with elemental diet.

BACKGROUND: The mechanisms by which elemental diets induce remission in patients with Crohn's disease is unknown, but it has been suggested that improvement in nutritional state may play a part. METHODS: We assessed sequential changes in disease activity (clinical and laboratory indices and faecal excretion of indium-111-labelled leucocytes) and nutritional status (anthropometry, body composition variables), hepatic secretory proteins (albumin, pre-albumin, transferrin), and trace elements (iron, magnesium, copper, zinc) during treatment of acute Crohn's disease with an elemental diet. RESULTS: Disease activity indices improved significantly by 2 weeks and were maintained at 4 weeks of treatment. There was a significant increase in pre-albumin at 4 weeks and an increase in serum iron and a decrease in serum copper during the study period. The changes occurring in the measures of nutrition did not correlate significantly with the changes in disease activity. CONCLUSION: The fact that changes in disease activity appear to precede any detectable changes in nutritional state, it suggests that the beneficial action of elemental diet in patients with active Crohn's disease is not due to an improvement in nutritional status.

Adolescent↗
PubMed1994

Comparison of enteral feeding and total parenteral nutrition after liver transplantation.

Total parenteral nutrition is used for nutritional support in patients undergoing orthotopic liver transplantation but is associated with complications. We compared the efficacy and tolerability of early enteral feeding with total parenteral nutrition after liver transplantation. 24 patients were studied: 14 received enteral feeding and 10 total parenteral nutrition. A double-lumen enteral tube was used to deliver the feed directly into the jejunum with the second lumen of the tube being used for gastric aspiration. Enteral feeding was started post-operatively within 18 h, was well-tolerated, and of comparable efficacy to total parenteral nutrition. The median number of days for patients to start eating (4) and to achieve 70% of estimated requirements orally (5) did not differ significantly between the two groups. Mid-arm circumference, triceps skinfold thickness, and biceps skinfold thickness were, by comparison with pre-operative values, maintained on the tenth postoperative day in both groups. Early postoperative absorptive capacity, as assessed by a combined carbohydrate test, was reduced significantly in both groups but insufficiently to be of nutritional concern. Intestinal mucosal integrity, as assessed by an intestinal permeability test, was maintained throughout. We conclude that the practical aspects of enteral feeding after liver transplantation are surmountable and that enteral feeding is as effective at maintaining nutritional status as total parenteral nutrition, and has potential benefits in terms of reduced complications and costs.

3-O-Methylglucose↗
PubMed1994

Nonsteroidal antiinflammatory drug-induced small intestinal inflammation and blood loss. Effects of sulfasalazine and other disease-modifying antirheumatic drugs.

OBJECTIVE: To identify the source of intestinal blood loss in rheumatoid arthritis patients being treated with nonsteroidal antiinflammatory drugs (NSAIDs) and assess the response to sulfasalazine and other disease-modifying antirheumatic drugs (DMARDs). METHODS: Intestinal inflammation, blood loss, and gastroduodenal damage, and the response to treatment with DMARDs, were assessed in 46 patients taking NSAIDs. RESULTS: Intestinal inflammation and blood loss correlated significantly with one another (r = 0.43, P < 0.003), but not with the macroscopic or microscopic appearance of the gastroduodenal mucosa. Sulfasalazine reduced both intestinal inflammation and blood loss, whereas the other DMARDs did not. CONCLUSION: The small intestine is the main site of mild chronic blood loss in patients receiving NSAIDs, and this blood loss can be reduced with sulfasalazine treatment.

Aged↗
PubMed1994

The effect of intestinal hypoperfusion on intestinal absorption and permeability during cardiopulmonary bypass.

BACKGROUND/AIMS: Mean arterial pressure is reduced during hypothermic cardiopulmonary bypass. The aim of this study was to assess whether this was associated with intestinal hypoperfusion and whether it affected intestinal absorption and permeability. METHODS: Twenty-six patients undergoing coronary artery bypass grafting underwent an intestinal absorption-permeability test involving ingestion of 3-O-methyl-D-glucose, D-xylose, L-rhamnose, and lactulose. Ingestion took place 2 days before, within 3 hours, and 5 days after hypothermic cardiopulmonary bypass. Hemodynamic parameters and gastric mucosal laser Doppler blood flow were measured perioperatively in eight patients. RESULTS: Hypothermic (28 degrees C), nonpulsatile cardiopulmonary bypass resulted in a 25% reduction in mean blood pressure, 10% reduction in cardiac index, and a 46% reduction in gastric mucosal laser Doppler blood flow. There was 85.4%, 85.5%, and 73.6% reduction (P < 0.01) in active (3-O-methyl-D-glucose) and passive (D-xylose) carrier-mediated transport and passive, nonmediated transcellular (L-rhamnose) transport in the immediate postoperative period, respectively. The differential urine excretion of lactulose/L-rhamnose increased sixfold. All parameters returned to control levels by the fifth postoperative day. CONCLUSIONS: Cardiopulmonary bypass, while maintaining generally acceptable levels of hemodynamic performance, is associated with significant intestinal hypoperfusion and malabsorption of monosaccharides, which may have implications for enteral drug treatment in the immediate postoperative period.

Adult↗
PubMed1994

Intestinal permeability.

Damage to the mucosal barrier may be assessed, non-invasively by use of sugar probes, which permeate through the transcellular or paracellular (tight junction) routes. A standardised test, with analysis of a five hour urine collection has proved useful in studying the sequelae of non-steroid anti-inflammatory drug (NSAID) administration, untreated coeliac disease, and enteric infections. Choice of probe molecule is crucial and lactulose/l-rhamnose seem to be satisfactory, in contrast with polyethylene glycol. Significant correlations have been seen between permeability and plasma IgA concentrates in nephropathy, and between permeability and the passage of neutrophil chemotactic agents. The increased permeability associated with NSAID treatment may relate to the adverse effects of NSAIDs on enterocyte mitochondrial morphology and metabolism. These two factors may predispose the mucosa to permeation of bacterial chemoattractant molecules that elaborate a local inflammatory response. A similar mechanism may operate in patients with untreated Crohn's disease, who show abnormally high permeability. Remission induced by treatment with elemental diets coincides with a reduction in permeability. The period to relapse correlated with the inability of patients to maintain low permeability to sugar probes. These results suggest a mechanism for the benefits of elemental enteral nutrients in the treatment of Crohn's disease.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1994

Studies on the enteropathy associated with primary hypogammaglobulinaemia.

Twelve patients with primary hypogammaglobulinaemia with diarrhoea not associated with known microbial pathogens were investigated. Histological evidence of inflammation was common in the stomach and jejunum. Moreover, eight of 10 patients undergoing colonoscopy had low grade 'microscopic colitis' with raised intraepithelial lymphocytes and an intact crypt architecture. Five of 12 patients had small intestinal inflammation on 111indium leucocyte scintigrams and all had increased faecal excretion (normal < 1%) of 111indium (over four days), which varied in intensity from mild (faecal excretion of 111indium = 1-3%) to that comparable with moderately active (7-14.5%) Crohn's disease. Three patients had small intestinal strictures superficially resembling Crohn's disease. Histologically, however, these lacked characteristic diagnostic features of Crohn's disease in two and the third patient had non-steroidal anti-inflammatory drug induced diaphragm like strictures. Six of seven who were most severely symptomatic were successfully treated with an elemental diet with rapid improvement of symptoms. The faecal excretion of 111indium was repeated in five and all improved but histologically the colitis remained unchanged. These studies show that some patients with primary hypogammaglobulinaemia have intestinal inflammation unlike that found in classic inflammatory bowel disease. Elemental diet is a useful temporary measure in the treatment of these patients.

Agammaglobulinemia↗
PubMed1994

Comparison of four markers of intestinal permeability in control subjects and patients with coeliac disease.

BACKGROUND: Controversy surrounds the issue of intestinal permeability in patients with coeliac disease, polyethylene glycol 400 indicating reduced and di-/mono-saccharide urine excretion ratios and 51Cr-labeled ethylenediaminetetraacetic acid (EDTA) indicating increased permeability. METHODS: We assessed the suitability of polyethylene glycol 400, L-rhamnose, lactulose, and 51Cr-EDTA as markers of intestinal permeability by assessing urine excretions after simultaneous intravenous instillation of these markers and after oral administration in normals and patients with coeliac disease. RESULTS: After intravenous administration the 24-h urine excretion of polyethylene glycol 400, L-rhamnose, lactulose, and 51Cr-EDTA was 40%, 72%, 93%, and 97%, respectively. There was no significant difference between controls and patients with coeliac disease. Oral administration of the markers in an iso- and hyper-osmolar test solution demonstrates reduced permeation due to an osmotic retention effect of lactulose. In contrast, hyperosmolar glycerol increases permeation of all markers except L-rhamnose. Timing of urines and altering osmolarity is important for the behavior of individual markers but does not enhance the discrimination between controls and patients when the differential urine excretion of lactulose/L-rhamnose is used. The sensitivity of the urine excretion ratio of lactulose/L-rhamnose was comparable to that of 51Cr-EDTA used by itself. Whereas lactulose/L-rhamnose and 51Cr-EDTA showed increased intestinal permeability in coeliac disease, the permeation of polyethylene glycol was reduced. Permeation of the markers did not correlate significantly with jejunal histology. CONCLUSIONS: Correlations of marker permeation rates with test dose osmolarity in controls and patients with coeliac disease shows a variable lack of conformity, suggesting that the markers may permeate the intestine by different routes, which are affected to a different extent in coeliac disease.

Celiac Disease↗
PubMed1993

Cardiopulmonary bypass impairs small intestinal transport and increases gut permeability.

Gastrointestinal damage occurs in 0.6% to 2% of patients after cardiopulmonary bypass (CPB), and carries a mortality of 12% to 67%. The incidence of subclinical gastrointestinal damage may be much greater. We examined the effects of nonpulsatile, hypothermic CPB on intestinal absorption and permeability in 41 patients. Bowel mucosal saccharide transport and permeation were evaluated using 100 mL of an oral solution containing 3-O-methyl-D-glucose (0.2 g), D-xylose (0.5 g), L-rhamnose (1.0 g), and lactulose (5.0 g) to assess active carrier-mediated, passive carrier-mediated, transcellular, and paracellular transport, respectively, with a 5-hour urine analysis. Patients were studied before, immediately after, and 5 days after CPB. Immediately after CPB there was a decrease in urinary excretion of 3-O-methyl-D-glucose (from 34% +/- 2.2% to 5.2% +/- 0.7%; p < 0.0001), D-xylose (from 25.4% +/- 1.4% to 4.1% +/- 0.8%; p < 0.0001), and L-rhamnose (from 8.3% +/- 0.6% to 2.6% +/- 0.4%; p < 0.0001). The permeation of 3-O-methyl-D-glucose and D-xylose returned to normal levels 5 days after CPB, but that of L-rhamnose remained significantly below pre-CPB values at 6.6% +/- 0.5% (p = 0.004). However, the permeation of lactulose increased after CPB (from 0.35% +/- 0.04% to 0.59% +/- 0.1%; p = 0.018), and the lactulose/L-rhamnose gut permeability ratio increased markedly (from 0.045 +/- 0.04 to 0.36 +/- 0.08; normal = 0.06 to 0.08; p = 0.004). Patients who had a CPB time of 100 minutes or more had a greater increase in gut permeability (p = 0.049).(ABSTRACT TRUNCATED AT 250 WORDS)

3-O-Methylglucose↗
PubMed1993

Side effects of nonsteroidal anti-inflammatory drugs on the small and large intestine in humans.

BACKGROUND: It is not widely appreciated that nonsteroidal anti-inflammatory drugs (NSAIDs) may cause damage distal to the duodenum. We reviewed the adverse effects of NSAIDs on the large and small intestine, the clinical implications and pathogenesis. METHODS: A systematic search was made through Medline and Embase to identify possible adverse effects of NSAIDs on the large and small intestine. RESULTS: Ingested NSAIDs may cause a nonspecific colitis (in particular, fenemates), and many patients with collagenous colitis are taking NSAIDs. Large intestinal ulcers, bleeding, and perforation are occasionally due to NSAIDs. NSAIDs may cause relapse of classic inflammatory bowel disease and contribute to serious complications of diverticular disease (fistula and perforation). NSAIDs may occasionally cause small intestinal perforation, ulcers, and strictures requiring surgery. NSAIDs, however, frequently cause small intestinal inflammation, and the associated complications of blood loss and protein loss may lead to difficult management problems. The pathogenesis of NSAID enteropathy is a multistage process involving specific biochemical and subcellular organelle damage followed by a relatively nonspecific tissue reaction. The various possible treatments of NSAID-induced enteropathy (sulphasalazine, misoprostol, metronidazole) have yet to undergo rigorous trials. CONCLUSIONS: The adverse effects of NSAIDs distal to the duodenum represent a range of pathologies that may be asymptomatic, but some are life threatening.

Animals↗
PubMed1993

The prevention and healing of acute non-steroidal anti-inflammatory drug-associated gastroduodenal mucosal damage by misoprostol.

This double-blind study assessed the acute development of NSAID-associated gastroduodenal (GD) damage and its prevention by misoprostol. Patients requiring chronic NSAID therapy were stratified into two groups depending on initial endoscopic appearance, Group I: normal (n = 223); Group II: non-ulcer lesions (n = 78). After 2 weeks of therapy with NSAID and either misoprostol 400-800 micrograms daily or placebo the incidence of severe mucosal damage (including ulcers) was significantly reduced by misoprostol (odds ratio; 95% CI). Group I: 4.52; 1.94, 10.51 (P = 0.018); Group II: 10.93; 1.09, 109.60 (P = 0.014); Groups I and II combined: 5.95; 3.23, 10.94 (P = 0.0003). Misoprostol exerted a significant protective effect against progression of minor to severe damage in Group II (P < 0.001). Endoscopic findings did not correlate significantly with gastrointestinal symptoms and misoprostol did not interfere with the NSAID efficacy. Significant GD damage occurs early in the course of NSAID treatment and misoprostol significantly reduces the incidence of such damage.

Adult↗
PubMed1993

Gastritis in patients on non-steroidal anti-inflammatory drugs.

This study investigated the spectrum of gastric mucosal pathology, including the prevalence of reactive gastritis in patients on non-steroidal anti-inflammatory drugs (NSAIDs). The histological findings were correlated with upper gastrointestinal symptom status and endoscopic findings and were also compared with the histological appearances of the gastric mucosa in a corresponding age-matched control group of 75 patients not receiving NSAIDs or any other drug therapy. Reactive gastritis of the gastric antrum was more common in the NSAID group and was observed in 34 patients (45.3%), as an isolated phenomenon in 24 patients (32%) and with evidence of coexistent chronic gastritis in 10 patients (13.3%). In the control group reactive gastritis of the antrum was seen in 10 patients (13.3%), as an isolated finding in eight cases (10.7%) and with accompanying chronic gastritis in two cases. Chronic antral gastritis of usual type was observed in 36 patients on NSAIDs (48%) and Helicobacter-like organisms were identified histologically in 18 of these (50% carriage rate). These organisms were not seen in any of the patients in whom the picture of reactive gastritis was present. In the control group chronic antral gastritis was seen in 51 patients (68%) with organisms in 34 (66.6% carriage rate). No correlation was found between the presence or absence of upper gastrointestinal symptoms, endoscopic findings and the histological appearances of the gastric mucosa. We conclude that NSAIDs are an independent cause of reactive gastritis in the antrum and do not appear to alter gastric mucosal colonization by Helicobacter-like organisms.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Comparison of leukocyte excretion and blood loss in inflammatory disease of the bowel.

Clinical relapse of inflammatory bowel disease is characterised by increased neutrophil migration into the intestine. The site of the neutrophil chemoattractant(s), whether luminal or mucosal, may be important since, on contact with a chemoattractant, neutrophils cause indiscriminate damage to their immediate surroundings by generating reactive oxygen species and by lysosomal enzyme release. If this happens within the mucosa, inflammation should correlate significantly with tissue damage as assessed by bleeding, but if it occurs within the intestinal lumen, the inflammation would be disproportionately greater than the bleeding such as is seen in classical exudation. Intestinal inflammation and bleeding were quantitated with the simultaneous use of indium-111 labelled neutrophils (four day faecal excretion of indium-111) and chromium-51 labelled red cells in patients with ulcerative colitis (n = 12), Crohn's disease (n = 15), and NSAID induced enteropathy (n = 34). Intestinal inflammation and blood loss correlated significantly (Spearman) in patients with ulcerative colitis (20.3% v 6.5 ml/d (median) r: 0.85, p < 0.001) and NSAiD enteropathy (1.6% v 1.9 ml/d, r: 0.60, p < 0.01) but not in Crohn's disease (17.0% v 2.1 ml/d, r: 0.38, p > 0.1). For a given indium-111 excretion, patients with ulcerative colitis had significantly greater (p < 0.01) blood loss than patients with Crohn's disease. These results suggest that the predominant site of neutrophil chemoattractants may be within the mucosa in ulcerative colitis and NSAID enteropathy and within the lumen in Crohn's disease.

Adolescent↗
PubMed1993

Food intolerance and Crohn's disease.

It has been claimed that prolonged remissions of Crohn's disease can be achieved after enteral or parenteral nutrition, by identifying and excluding foods that exacerbate a patient's symptoms. The occurrence of food intolerances were assessed after induction of remission with elemental diet in 42 eligible patients to whom single foods were introduced over five days. Suspect foods were reinvestigated with open and if possible, double blind rechallenge. Fourteen patients (33%) dropped out of the study because of relapse of disease unrelated to food (n = 8) or because of difficulties in complying with the regimen (n = 6). Twenty (48%) of the patients identified food sensitivities whereas eight (19%) did not. Seventeen of the patients who identified food sensitivities had an open rechallenge with recurrence of symptoms in 10 (24% of total). Food sensitivity was confirmed in three patients on double blind challenge. There was no significant difference in the duration of remission between patients who did or did not identify food sensitivities. During the study three cases of intolerance to the formula diet, and one of severe salicylate sensitivity were encountered. In conclusion food sensitivities are evident after treatment of Crohn's disease with elemental diet but are variable, often do not persist, and are of insufficient importance to warrant putting all patients through elimination diets.

Adolescent↗
PubMed1993

NSAIDS and gastropathy.

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Anti-Inflammatory Agents, Non-Steroidal↗