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Biomedical subjects

M Hiele

Publications and source records attributed to M Hiele.

65 records · Page 4Linked to original sources

Measurement of 13C-glucose oxidation rate using mass spectrometric determination of the CO2: Ar ratio and spirometry.

A new method was developed and validated for measuring the CO2 concentration in the breath by mass spectrometric analysis. Argon, an inert gas that is present in air in a constant concentration of 0.923%, was used as an internal standard. By determining the ratio of CO2 (mass 44) to Ar (mass 40) in a breath sample, it was possible to read the CO2 concentration from a standard curve, relating CO2 concentration to CO2: Ar ratio. By combining mass spectrometric determination of CO2 concentration in breath with spirometric measurement of expired volumes, the CO2 production was determined in 67 subjects at rest. The mean value was 8.86 mmol kg-1 h-1, but there was considerable interindividual variation. This new method was applied to glucose oxidation studies in 10 normal subjects, 10 post-gastrectomy patients and 7 obese type II diabetic subjects. Measurement of the 13CO2 exhalation with quantitative determination of CO2 production allowed more accurate determination of the CO2 excretion rate in relation to blood levels of glucose, insulin and free fatty acids than assuming the constant CO2 production of 300 mmol unit body surface -1 h-1 or 9 mmol kg-1 h-1. It also resulted in a better discrimination between normal subjects and diabetics.

Adult↗

Measurement of the rate of assimilation of oligo- and polysaccharides by 13CO2 breath tests and isotope ratio mass spectrometry.

13CO2 breath tests were developed to study the digestion and absorption of (13C)lactose, (13C)sucrose, (13C)starch and (13C)glucose using naturally enriched substrates. Measurements of 13CO2 breath excretion were done in steady state conditions in order to study the assimilation rate of these carbohydrates as reflected by their oxidation rate. The reproducibility of the tests in the same individual was excellent. The excretion rate of 13CO2 after administration of (13C)glucose and (13C)sucrose was identical, while the excretion rate of 13CO2 after lactose was somewhat slower, although not significantly. In contrast, the excretion of 13CO2 after 50 g (13C)starch was significantly slower than the 13CO2 excretion after 50 g (13C)glucose or 50 g (13C)disaccharides. As the monosaccharide constituents used in this study have comparable absorption rates, the delayed excretion of 13CO2 after a (13C)starch load must be due to a slower digestion. It is concluded that (i) digestion and not monosaccharide transport is the rate-limiting step in the assimilation of polysaccharides and (ii) that the present breath tests are suitable to study the digestibility of naturally labelled carbohydrates.

Adult↗

The effect of long-term fibre and starch intake by man on faecal bile acid excretion.

Parameters of bile acid metabolism were studied in two populations with different dietary fibre and starch intake over a period of at least 5 years. Subjects with a high fibre and starch intake have significant increases in faecal wet weight (288.5 g day-1 vs. 136.1), faecal dry weight (39.3 g day-1 vs. 20.2), faecal bile acid excretion (393.0 mg day-1 vs. 115.4) and faecal bile acid:faecal dry weight ratio (13.6 vs. 5.8). There was no difference in bowel transit time measured with 3H-PEG 4000 as marker of the liquid phase. The cumulative 14CO2 excretion during the bile acid breath test was higher in the high-fibre group, compared with the low-fibre group (4.6% dose cumulative at 8 h vs. 2.5%). Serum triglyceride and cholesterol levels were comparable in both groups. It is suggested that increased faecal weight and bile acid secretion is due to the synergic effect of high fibre and starch intake upon colonic bacterial proliferation.

Adult↗

13CO2 breath test using naturally 13C-enriched lactose for detection of lactase deficiency in patients with gastrointestinal symptoms.

A 13CO2 breath test using naturally enriched 13C-lactose as a substrate was performed in 47 patients with chronic abdominal pain or chronic diarrhea, taken from a population with a low prevalence of primary acquired lactase deficiency. The cumulative 13CO2 excretion 4 hours after 13C-lactose intake was compared with the H2 breath excretion and with jejunal lactase activity. A physiologically significant relation was found between the cumulative 13CO2 excretion (at 4 hours) and lactase activity, 14.5% 13CO2 excretion being the best cutoff point for discrimination between patients with low and normal lactase activity. The 13CO2 breath test was found to be more sensitive (0.84 versus 0.68) and more specific (0.96 versus 0.89) than the H2 breath test in detecting low jejunal lactase activity. Concordant results of both breath tests performed simultaneously give a reliable picture of the lactose absorption status of the patient. Discordance in results of 13CO2 and H2 lactose breath tests, if not explained by history, indicates in which patients a jejunal biopsy should be performed. If lactase activity and morphology of the biopsy are normal, other causes of discordance must be investigated.

Abdomen↗

Selection criteria and outcome of patients referred to intestinal transplantation: an European center experience.

Until 1998, intestinal transplantation (SBT) had not been performed in our region of Flanders, Belgium. Potential SBT activity was not known and selection criteria had not been validated. A multidisciplinary SBT program was launched in 1998. We analyzed requests for SBT and outcomes in these patients whether with or without SBT. Listing for SBT was only considered for patients with irreversible short bowel syndrome who had developed life-threatening complications of total parenteral nutrition, but whose general condition was still thought compatible with surgery and immunosuppression. During the study period 1998 to 2004, one third of the requests for SBT (10/31) were deemed suitable. SBT in this group was lifesaving (100% survival) when performed in time. Mortality in this group without SBT was high (67%). Two thirds of the patients (21/31) did not fulfill the SBT inclusion criteria, either because they were "too moribund" to tolerate transplantation or because they were "too well". This preliminary study emphasized the importance of (1) early referral of potential SBT candidates, (2) adherence to strict criteria for listing patients for SBT, and (3) referral of intestinal donors to procurement organizations.

Adult↗

Effect of long-term oral glutamine supplements on small intestinal permeability in patients with Crohn's disease.

BACKGROUND: Glutamine is a major fuel and an important nitrogen source for the small intestinal cell. It plays a key role in maintaining mucosal cell integrity and gut barrier function. Increased permeability may be a factor in the pathogenesis of Crohn's disease and may be an interesting parameter in the follow-up of the disease. Therefore, the aim of this study was to examine whether oral glutamine supplements are able to restore an increased intestinal permeability in patients with Crohn's disease. METHODS: The inclusion criteria for the study were Crohn's disease and a disturbed small intestinal permeability for 51Cr-EDTA. Of 38 patients screened, 18 had an increased permeability (6 hours urinary excretion >1.1% of label recovered in urine). Fourteen patients were included in the study and were randomized to receive either oral glutamine (7 g three times per day; n = 7) or placebo (7 g glycine three times per day; n = 7) in addition to their normal treatment during a 4-week period. The study was performed in a double-blind manner. RESULTS: Baseline permeability (mean +/- SD) was 2.32%+/-0.77% dose in the glutamine group and 2.29%+/-0.67% dose in the placebo group. Permeability did not change significantly after glutamine (3.26%+/-2.15% dose) or after placebo (2.27%+/-1.32% dose). There was no significant effect on plasma glutamine, plasma glutamate, plasma ammonium, Crohn's disease activity index, C-reactive protein, or nutritional status. CONCLUSIONS: Oral glutamine supplements, in the dose administered, do not seem to restore impaired permeability in patients with Crohn's disease.

Administration, Oral↗

Ileal perforation caused by cytomegalovirus infection in an immunocompetent adult.

A 71-year-old woman developed a small bowel perforation due to cytomegalovirus infection. She did not taken any immunosuppressive medication and her cellular immunity was normal. Surgical resection and antiviral therapy with ganciclovir led to complete recovery. As far as we know, this paper reports the first case of small bowel perforation due to cytomegalovirus infection in a non-immunocompromised patient. Nevertheless the patient was known with diabetes mellitus. It should be emphasised that elderly patients have impaired immune defences and may be unsuspected hosts of opportunistic infections.

Aged↗

Treatment of acute diarrhoea: update of guidelines based on a critical interuniversity assessment of medications and current practices.

Further to a thorough analysis of the problem of acute diarrhoea and the therapeutic options, recommendations were defined following a multidisciplinary approach. These guidelines take into account the reality of frequent self-medication. They further differ as a function of age (children, primarily treated by ORS and for whom self-medication is not advised versus adults who can self-medicate), symptoms (uncomplicated diarrhoea versus dysentery) and location where the diarrhoea is contracted (at home or when travelling).

Acute Disease↗

Georges Brohee Prize 1988-1989. Assimilation of nutritional carbohydrates: influence of hydrolysis.

The influence of hydrolysis on the assimilation rate of important nutritional carbohydrates was studied in healthy subjects and patients with intestinal diseases, mainly by means of 13CO2 breath test techniques. All substrates were "naturally enriched" with carbon-13. The studies showed that hydrolysis is the rate limiting step for the assimilation of lactose, starch and even maltose, but not for the assimilation of sucrose. The degree of gelatinisation and the degree of side-branching of starch molecules were two important parameters, influencing starch hydrolysis in normal subjects. Addition of wheat bran had no influence on the digestion rate of starch. A comparative study between normal subjects and patients with pancreatic disease, showed that starch digestion may be impaired in patients with pancreatic disease. However, this occurs only if amylase output is extremely low. The effect of lactase deficiency on lactose absorption was studied in patients with a history suggestive of lactase deficiency. For this purpose a lactose 13CO2 and H2 breath test were compared with lactase activity in a jejunal biopsy. The results showed that the relation between lactase activity in the biopsy and lactose assimilation takes the form of a saturation curve. The 13CO2 breath test was found to be a reliable test for the diagnosis of lactase deficiency. Finally, the effect of acarbose on starch digestion was studied in normal subjects, ileostomy patients, and a fecal incubation system. These experiments showed that acarbose may induce an important degree of starch malabsorption. If administered in high doses, the effect is not only related to inhibition of brush border enzymes, but also to the inhibition of alpha-amylase.

Blood Glucose↗

Efficacy and safety of hydrostatic balloon dilation of ileocolonic Crohn's strictures. A prospective long-term analysis.

Gastro-intestinal stricture frequently is a complication in Crohn's disease and often recurs after surgical resection. Stenosis with acute inflammation can be treated by anti-inflammatory medication. A conservative approach of sclerotic strictures has been possible since the introduction of Gruentzig balloon catheters for dilating stenosis in different parts of the gastro-intestinal tract. We present a prospective follow-up study in 55 patients, on the long-term results and safety of hydrostatic balloon dilations of ileo-colonic Crohn's strictures.

Adolescent↗