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Biomedical subjects

R Laue

Publications and source records attributed to R Laue.

At least 19 recordsLinked to original sources
PubMed1990

Intestinal absorption of D-xylose in the early post-operative period.

To assess intestinal absorption in the early post-operative period, portal and subclavian vein catheters were implanted into 8 pigs. For direct d-xylose infusion into the upper small intestine a feeding tube was inserted via a gastrostomy. Four control animals (Group 1) underwent an open and close laparotomy after catheter and tube implantation. Four pigs (Group 2) underwent a standardised ileocoecostomy. At 6, 24, 36, 48 and 72 h after surgery, d-xylose was infused into the small intestine in both groups of animals. After single-dose administration the absorption kinetics were measured in the pre- and post-hepatic blood compartment. With increasing time after operation the rate and extent of d-xylose absorption returned towards normal but there were significant differences in the d-xylose kinetics between the two groups. The absorption kinetics and d-xylose uptake recovered more rapidly in the control group than in those who underwent ileocoecostomy. Effective enteral feeding in controls after 36 h was achieved, but in Group 2 was delayed until 48 h post-operatively. Absorption capacity returned to normal after 48 h in controls and after 72 h in Group 2.

Journal Article↗
PubMed1990

[Use of the stable nitrogen isotope 15N in assessing liver metabolism in hormonal contraception].

In 37 women with long-term use of oral contraceptives (average use 13.4 years) and 12 women who had not taken oral contraceptives for at least 5 years we determined the serum enzymes ALAT, ASAT, Gamma-GT and conducted the 15N-ammonium test as a marker of partial metabolic performance of the liver. In addition we studied total protein, protein fractions in the serum and haematologic parameter. 18 out of 37 women showed a morbid result in the 15N-ammonium test. In 4 of these 18 women morphological changes representing hepatic damage caused by contraceptives could be detected. On the average ALAT, Gamma-GT and 15N-ammonium test in both groups are clearly different. Because the enzymic levels are being in the normal range, only the 15N ammonium test enables to give a hepatotoxic evidence. It is possible to conclude that long-term use of oral contraceptives influences the liver metabolism.

Adult↗
PubMed1988

[Resorbate kinetics in the pre- and posthepatic blood compartment in the immediate postoperative phase in swine].

Catheters were implanted in the portal vein by the superior mesenteric vein in pigs for valuation of the absorbant kinetics of enterically applied substances in the mesenteric veins. The blood level kinetics after applying 10 g D-xylose into the jejunum was measured continuously simultaneously in the pre- and posthepatic blood compartment 6, 24, 36, 48, and 72 hours after the operative procedure. An enteric resorption of the pentose is provable already 6 hours after the operation, with their utter normalization in the next 36 hours. The differences between the pre- and the posthepatic concentration-time-graphs admits conclusions on the metabolism of the absorbant in the liver.

Animals↗
PubMed1986

[Enteral resorption kinetics in the aging process].

With growing age functional and morphological changes in the alimentary tract appear. The age dependence of the intestinal absorption was investigated with the help of the modified D-xylose absorption test. By means of a graphic-mathematical evaluation of the blood level kinetics of D-xylose after oral and intravenous application the absorption rapidity (constant k12), the temporary position of the relative maximum of the D-xylose concentrations in the blood serum after oral application (time tm) and the size of the relative absorption of the small intestine were established depending on the time RR (t). Within the age range of 3 to 96 years it has been proven that a slowing down of the enteral absorption occurred with growing age. By prolonging the period during which the food components are absorbed in the small intestine (shift of tm towards later times) the old organism is just as capable of complete absorption as is the young one, even though the absorption processes take place at a slower rate. Absorption disorders in old age are due to morbidity and not, sui generis, to involution.

Adolescent↗
PubMed1986

[Alcohol induced damage to the pancreas in patients with increased blood alcohol levels detected in road traffic].

50 patients, driving motor-cars, having increased blood alcohol levels, were registrated and prosecuted. They voluntary underwent catamnestic researches for early diagnosis of alcohol induced lesions of the pancreas. In relation to the habitual drinking systems the study concluded 28 (56 per cent) healthy persons, 13 (26 per cent) alcohol endangered cases, 9 (18 per cent) alcoholics. Various biochemical parameters were changed, liver histomorphology resulted in about 50 per cent of cases a fatty degeneration of the liver and hepatitis. Special diagnostic methods (CCK-test, ERCP, ultrasound echography, computer-tomography) submitted in 24 per cent of cases suspect of alcohol induced pancreatitis. Results, which promote alcoholic pancreatic damage, are being discussed.

Adolescent↗
PubMed1984

Age-dependent alterations of intestinal absorption. I. Theoretical aspects.

To test the absorption of orally administered D-xylose in the upper small intestine its concentration in the blood plasma must be measured. Absorption is determined as a function of time by subtraction of the blood values found after intravenous administration, which would indicate the rates of metabolism and extraction of xylose by the body. It is suggested that comparison with the behavior of a proposed four compartment model may give a biological interpretation of the results. The possible dependence of amount and rate of absorption can be determined if the same time after feeding of the same diet is used in each absorption measurement. It is suggested that the time point to be used for administration be that time at which the highest concentration of xylose in the peripheral blood is found.

Adolescent↗
PubMed1984

Age-dependent alterations of intestinal absorption. II. A clinical study using a modified D-xylose absorption test.

With advancing age functional and morphological changes take place within the intestinal tract. The age-dependency of intestinal absorption has been studied using a D-xylose absorption test. The absorption rate (constant k12), the time of appearance of the relative maximum of the D-xylose concentrations in the blood serum after oral administration (time tm), and the extent of the relative absorption in the small intestine as a function of time RA(t) were determined by graphic-mathematical evaluation of the blood level kinetics of D-xylose after oral and intravenous administration. Within the age range of 3 to 96 yr, it has been proven that a slowing down of intestinal absorption occurs with advancing age. By prolonging the period during which the food components are absorbed in the small intestine (shift of tm towards the absorption processes take place at a slower rate. Absorption disorders in old age are due to morbidity and not, sui generis, to involution.

Adolescent↗
PubMed1984

A modified D-xylose absorption test.

A modified D-xylose-test is described which enables intestinal absorption to be assessed independently of renal and hepatic function. The speed of appearance of the peak of D-xylose-concentration in plasma after an oral administrated dose and the extent of absorption in the small intestine as a time-function, were analysed by graphic-mathematical evaluation of the kinetics of plasma D-xylose concentration after oral and intravenous administration. Small intestinal functional integrity was assessed in 172 normal individuals (aged from 3 to 96 years), also in 9 patients with coeliac disease. The speed and the extent of D-xylose absorption were significantly reduced in all cases of untreated coeliac disease and during relapse. There were no differences between normal individuals and treated patients. Experience over many years indicates that the modified D-xylose-test is a simple, reliable and inexpensive standard method for detecting changes in intestinal absorption.

Adolescent↗
PubMed1984

[Function diagnosis of small intestine absorption using the modified D-xylose absorption test].

Based on a biophysical model of the absorptive system a modified D-xylose test has been inaugurated, which is well suited to comprehensively assess the process of intestinal absorption. According to the author's experience of many years the test is a well-suited method for detecting changes in intestinal absorption. It excels by its high validity and reliability. Its practical accomplishment is easy and needs no expensive equipment. The method and the processing and evaluation of the measured values are described in detail.

Adolescent↗
PubMed1981

Influence of dimethylsulfoxide on transcription by bacteriophage T3-induced RNA polymerase.

Dimethylsulfoxide (DMSO) up to 25% (v/v) does not cause irreversible alterations of T3 DNA at 42.5 degrees C as assayed by transcription with T3-specific RNA polymerase. The optimal temperature for the formation of polyanion-resistant ternary complexes of the enzyme, T3 DNA, and nascent RNA chains is lowered by 12.5 degrees C in the presence of 20% (v/v) DMSO. The same solvent concentration, however, decreased the temperature optimal for T3 RNA chain elongation by only 2.5 degrees C, indicating that DMSO preferably affects the initiation of T3 RNA synthesis. DMSO accelerates the loss of T3-specific RNA polymerase activity at 24.5 degrees C. Nevertheless, the speed with which the binary complexes between the phage RNA polymerase and DNA are inactivated by heat (42.5 degrees C) is not altered in presence of 20% (v/v) DMSO. The binding of T3-induced RNA polymerase to T3 DNA in polyanion-resistant ternary complexes is influenced by DMSO which makes the enzyme accessible to the inhibitory action of polyvinyl sulfate. Elongation of T3 RNA chains is slowed down by 20% (v/v) DMSO.

DNA, Viral↗
PubMed1981

[Asynchronic changes of absorbing and renal excretion function in aging (author's transl)].

Founded upon experimental and theoretical investigations the age-dependence of the absorbing system and renal excretion function in human being have been analysed. We used a modified D-xylose-test with oral and parenteral xylose-application and mathematical calculation on the base of results of blood-level analysis. Starting from a compartment model the velocity of D-xylose absorption and excretion could be by means of this functional test examined. The velocity of intestinal absorption and renal excretion decrease with age asynchronous.

Adolescent↗
PubMed1981

[Comparative studies of enteral resorption kinetics of D-xylose in humans and experimental pigs].

The enteric transport kinetics of peroral applied D-xylose was comparatively analysed with help of a modified D-xylose absorption test in man and in experimental pig. The animal experimental investigations were carried out in 10 female hybrid pigs at the age of 3 to 8 months. The absorption quickness and the dimension of the effective small intestine absorption in dependence on the time does not show any statistically significant differences between both biological systems. On the other hand the experimental animals show a statistically secured higher elimination quickness of D-xylose in contrast to the comparison group of healthy adults.

Animals↗
PubMed1981

[Enteral resorption in the immediate postoperative phase following selective proximal vagotomy].

The postoperative absorption of the small intestine after selective proximal vagotomy was found out by means of the modified D-xylose absorption test in 23 patients on operating day, and on 1st, 5th, 8th, 9th and, 10th postoperative day. The constant of the adsorption speed was reduced on the operating day and decreased further to the 4th postoperative day. Afterwards the preoperative value was obtained approximately. The temporal state of the relative maximum of the curve of serum concentration (the moment tm) occurred in the same time interval. The tm-value obtained the preoperative value approximately. The dimensions of the absorption in the small intestine was reduced by 36% on the operating day, by 20,5% on the 1st postoperative day, and by 10% on the 4th postoperative day on the arithmetical average. The influence of the gastric emptying after SPV and of gastro-intestinal hormones on the process of absorption was discussed.

Adult↗
PubMed1980

[The aging of intermitotic cells (author's transl)].

The aging of the cells depends on their mitotic activity, which is particularly evident in multicellular organisms. By way of histoautoradiography we studied the cell kinetics on a total of 244 Wistar rats aged 6 days, 6 weeks, 6, 12, 23 and 28 months respectively, with these studies being centred on the mucosa of the small intestine since this mucosa is one of those tissues with the highest cell metabolism. We succeeded in demonstrating that the regeneration rate of cells per hour in the crypts of the small intestine and the migration speed of the enterocytes differ in young and old individuals and that the intermitotic cells have age-dependent properties as well. In addition, we could prove that intermitotic cells too have a non-growth fraction which, at an advanced age, decreases only a little, although significantly in terms of statistics. For the easily vulnerable crypt epithelium it is a reserve capacity and can be included in the proliferating pool, if necessary.

Animals↗
PubMed1980

[On the effect of biologically active substances (experimental studies) (author's transl)].

The influence of prolonged Procaine and Turigeran therapy on the cellular kinetics of the mucous membrane of the liver and small intestine has been studied by means of 3H-thymidine histo-autoradiography of a total of 240 12-month-old male Wistar rats. The following observations have been made: 1. The pool of DNA-synthesizing liver parenchyma cells and Kupffer's cells in the treated animals is clearly increased compared with that of the untreated controls. There is no difference between the rats treated with Procaine and those treated with Turigeran. 2. Nor does the cellular kinetics of the mucosa of the small intestine exhibit any differences between the animals treated with Procaine and those treated with Turigeran. Since, on the other hand, significant differences appear between the treated animals and the untreated controls regarding all characteristics of cellular kinetics, this effect is solely attributable to Procaine. 3. The various phases of the cellular cycle are prolonged in the treated animals, resulting in an overall delay in the generative cycle. 4. A reduced speed of migration of the cells in the region of crypts and villi finally results in the fact that in spite of the reduced rates of proliferation a greater number of labelled cells can be observed in the crypts of the treated animals (labelling index). 5. The unmitigated effect of Procaine is discernible for at least two weeks after the discontinuation of the treatment.

Animals↗