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Biomedical subjects

K Rommel

Publications and source records attributed to K Rommel.

At least 19 recordsLinked to original sources

Effects of secretin and cholecystokinin-pancreocymin on water, electrolyte and glucose absorption in human jejunum. A comparison between different hormone preparations.

The effects of natural secretin (90%) and synthetic secretin as well as impure (10%) and pure (99%) cholecystokinin-pancreozymin (CCK) on net absorption of water, electrolytes, and glucose in human jejunum were studied in 31 normal subjects. An intestinal perfusion technique with a triple-lumen tube was used. Net absorption of water and solute was significantly inhibited by both hormones only with larger doses, pure CCK being less active than impure CCK. A dose-dependent response of water and electrolyte absorption to graded doses of pure CCK was observed, without concomitant inhibition of glucose absorption with lower doses. The findings suggest that secretin and CCK may not be of physiologic importance regarding intestinal absorption in man. The definite changes in intestinal motility and transit rate caused by these hormones seem more likely to result in a reduction of intestinal absorption and an increase in the secretion of water and electrolytes along the proximal small bowel.

Adult

Synthetic human gastrin I and gastrin-like pentapeptide in studies of intestinal absorption in man. Role of gastrin in human intestinal absorption.

The effects of synthetic human gastric I (SHG I) and gastrin-like pentapeptide (PG) on jejunal water, electrolyte, and glucose absorption were studied in 11 normal subjects. The i.v. administration of graded doses of SHG I increased plasma gastrin levels similar to those after food intake and in the Zollinger-Ellison syndrome. SHG I and PG caused no significant changes in the net movement of water and solute. The findings indicate that gastrin has no direct effect on intestinal absorption in normal man, and does not account for the mechanism of diarrhea in the Zollinger-Ellison syndrome.

Adult

Elimination of low molecular weight polyethylene glycol 400 in the urine following an oral load, as a measure of intestinal permeability.

After an oral load of 10 g polyethylene glycol, its concentration in the urine was measured by gas chromatography. The coefficient of variation of the imprecision between run was about 11%. The urinary excretion was 25% of the administered dose with a coefficient of variation of the interindividual variation 26% and the intraindividual variation between 13% and 29%.

Humans

[Amylase in serum, amylase excretion and the amylase-creatinine-ratio. Individual variation and diagnostic specifity (author's transl)].

The amylase activity in serum, the amylase excretion and the amylase-creatinine-ratio was investigated in 25 volunteers monthly for one year and daily for two weeks. The intraindividual variation of the amylase-activity in serum showed only small oscillations. The large refernce value of the group and the need to use individual reference values prefer the 24 hour amylase excretion as a diagnostic tool. The amylase-creatinine-ratio showed individual and seasonal large variations. Therefore the ratio is not suitable for diagnostic questions.

Adult

[Circadian variation of intestinal sucrose and water absorption in rats (author's transl)].

A rat jejunal segment of 15 cm length was perfused single pass with a 3 mmol/l sucrose solution 4 times daily at 8.00, 14.00, 20.00 and 2.00. One group of rats was fed ad libitum, a second group was "meal fed" between 14.00 and 18.00. Sucrose absorption reached its maximum at 8.00 in the rats fed ad libitum whereas it was spread over a period of six hours (20.00-2.00) in the meal fed rats. The activity of sucrase in mucosal scrapings reached its peak at feeding time.

Animals

[Concept of reliable laboratory test procedures (author's transl)].

Considering the multitude of tests in clinical chemistry and hematology, their low diagnositc sensitivity and specifity, and the low incidence of the diseases in a non selected population it is not possible presently to recommend a general screening procedure based on the definition of the reference, the methodological reproducibility and the diagnostic information of a test procedure it is possible to calculate the number of requests necessary to get any desired number of pathological results. "Tell me how many pathological results you want and I'll tell you how many requests you need". In order to get an optimal diagnostic information for clinical chemistry and hematological tests, it is necessary to increase the prevalence by proper selection of the patients and then to order test procedures specific for the suspected disease.

Age Factors

[Urea and creatinine levels and clearances: observations in 25 healthy subjects for one year (author's transl)].

The seasonal, intra- und interindividual variation of the creatinine and urea concentrations in serum and urine and the clearances of these compounds were examined monthly for one year in 25 healthy volunteers. In contrast to the other parameters (serum urea, clearance and excretion of creatinine and urea), the variations in serum-creatinine concentration were small and statistically unsignificant. The variations of the urinary excretion and the clearance of creatinine and urea is due to seasonal variations in the output of the kidney.

Creatinine

[Absorption in the human small intestine relative to the intraluminal milieu].

The bulk of water and electrolyte absorption takes place in the human jejunum from isotonic solutions, and is determined largely by special transport mechanisms for different monosaccharides, amino acids and dipeptides. This is of considerable significance for regaining the large volumes of fluid delivered to the small intestine during the digestion of food. Small changes in intraluminal pH do not significantly influence the absorptive function of the jejunum and are rapidly compensated by the buffering capacity of the gut. The maintenance of an isotonic as well as neutral intraluminal milieu seems to be essential to the physiological processes of intestinal absorption.

Diarrhea

[Cytostatica and small intestine (author's transl)].

Cytostatica not only suppress proliferation in tumor cells but it also checks proliferation in small intestinal epithelium. The consequence is cell reduction and damage resulting in a diminished function. Because of the high reserve capacity of the small intestinal epithelium, clinical signs of diminished function are mostly seen after repeated high doses or one extremely high doses of Cytostatica. Although there is abundant information on the effect of Cytostatica on the small intestinal epithelium (cell turnover, morphology, digestive enzymes and absorption) there are other areas that are as urgent for the interested clinician to work on: 1. Would it be possible to coincide the dose and dosage rate with the cell cycles to reduce the chance of damage to small intestinal epithelium? 2. Which role has the luminal content when there is damage from Cytostatica? Is it possible to concentrate on changing the luminal contents (antibiotics, "elemental diet", cultivate desirable microflora, etc.) Therefore diminishing the damage from Cytostatica? 3. How would Cytostatica influence the barrier function on the intestinal wall? Should the patient on Cytostatica therapy receive special protection against intestinal infection? 4. Does Cytostatica affect the biotransformation in the small intestinal epithelium, especially when taken orally? How important is this biotransformation in small intestinal epithelium damaged by Cytostatica therapy? 5. What factors determine the regeneration of the small intestinal epithelium after Cytostatica damage?

Animals

[Influence of specimen withdrawal on the results of chemical analyses of blood, plasma and serum in patients with stable or centralized circulation (author's transl)].

The influence of circulatory conditions, point of blood withdrawal (arterial, central or peripheral venous) and the plasma-serum relation on 29 clinical chemical and hematological parameters were studied with 22 polytraumatized patients. The conditions studied significantly affect the results, and must be taken into consideration in evaluating the results and their comparison to reference values. This is especially important for the determination of the catalytic activities of creatine kinase, aspartate and alanine aminotransferases, and alkaline phosphatase in centralized-circulatory patients, for the total protein the electrophoretic fractions and analyses of blood gas as a function of the point of blood withdrawal, and for the total protein, gamma-globulins and potassium when plasma is analysed instead of serum.

Blood Cells

Reproducibility of the intravenous galactose tolerance test.

The reproducibility of the intravenous galactose tolerance test was investigated in eight healthy volunteers by performing the test five times under identical conditions in each individual. The results show that the interindividual scattering is much greater than the intraindividual variation. Therefore, and in connexion with the results of a previous investigation, the conclusion can be drawn that the intravenous galactose tolerance test is more suitable for the longitudinal course of patients than for the detection of an impaired liver function. A simplification of the test is possible by measuring the fasting galactose concentration and the blood galactose concentration 40 minutes after the galactose load.

Galactose

[Diagnostic value of the lipoprotein-X determination (author's transl)].

LP-X was investigated in the serum of 221 patients with and without cholestasis. The diagnostic sensitivity and the diagnostic specificity of the test were 0.9 and 0.88, respectively. When this test is used on a non-selected collective, however, the predictive value of the positive test is very low, whereas negative results have a high diagnostic value. Thus, in practice, LP-X is more suitable for the exclusion, rather than the detection of cholestasis.

Cholestasis