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Biomedical subjects

R Matkowitz

Publications and source records attributed to R Matkowitz.

At least 37 records · Page 2Linked to original sources

[Protein synthesis following experimental injuries in the pig as disease model. Comparison of infusion solutions with various amino acid patterns].

This study compares the effect of two amino acid solutions on protein metabolism after injury by measuring nitrogen balance, 15N-elimination, total body protein synthesis and utilisation of administered nitrogen in an experimental study using pigs. Protein synthesis and nitrogen utilisation were determined using a 15N-tracer technique with recourse to mathematical model concepts. The non-surgical control animals had a lower urinary nitrogen excretion, a more favourable nitrogen balance, a higher 15N-retention, greater total body protein synthesis and utilisation of the infused amino acids during infusion of an amino acid solution with a standard amino acid pattern (A) than the operated animals (solution B). Comparison of the post-operative data shows that if solution A is compared with solution B whose amino acid content takes account of changes in plasma amino acid metabolism following trauma, solution B yields the better results in respect of 15N-retention as well as total body protein synthesis and nitrogen utilisation.

Amino Acids↗

Protein synthesis after experimental injury in pigs. A comparison of infusion solutions with different amino acid patterns.

This study compared the effect of three amino acid solutions on protein metabolism after injury by measuring plasma amino acid pattern, nitrogen balance, total body protein synthesis and utilisation of administered nitrogen in an experimental protocol using pigs. Protein synthesis and nitrogen utilisation were determined using a 15N-tracer technique with recourse to mathematical model concepts. Control animals which had not undergone surgery had a lower urinary nitrogen excretion, a more favourable nitrogen balance, greater total body protein synthesis and utilisation of the infused amino acids during the infusion of an amino acid solution with a standard pattern of amino acids (A) than the operated animals infused with either solution A or two other test amino acid solutions B and C. Comparison of the post-operative data showed that if solution A is compared with solution (B) whose amino acid content takes account of changes in plasma amino acids following trauma and a solution (C) which contains a high fraction of branched chain amino acids, solution (B) yields the best results in respect of total body protein synthesis and nitrogen utilisation.

Journal Article↗

[Physiological nutrition studies of swine for the evaluation of modified proteins. 3. Relationship between the true and apparent N digestibility and amino acid absorption of the small intestines and the parameters of N metabolism].

Modified proteins were tested in absorption investigations with eight pigs with ileocaecal re-entrant cannulae. The apparent digestibility up to the end of the small intestines showed considerable differences between the feed proteins (77-93%). The same differences could be observed with regard to the apparent absorption of amino acids. Concerning the true N-digestibility resp. the true absorption of the amino acids in the above mentioned section of the intestinal tract there were hardly any differences between the proteins given. The results show that there is a relation between the amount of endogenous N in the chyme at the end of the small intestines and the protein consumed. The amount of endogenous N in the chyme in the small intestines influence N-excretion in urine and thus the intermediary utilisation of feed protein. From the point of view of nutrition physiology it follows that the spun vicia-faba protein/casein (1 : 1) fibres (C) approximate best the value of casein (A). While the treatment of this mixed protein with dyaldehyde starch had a negligible effect on the ascertained parameters only, the treatment of the same protein with aluminium chloride diminished its value more. The isolated vicia-faba (B) was the poorest of the modified proteins tested.

Amino Acids↗

[Nutritional and physiological studies of swine for the evaluation of modified proteins. 2. Determination of endogenous N in the contents of the small intestines using the 15N-tracer method].

The endogenous N-quota in the chyme of the small intestines after providing modified proteins was determined with re-entrant cannulae at the end of the ileum in investigations with pigs (35 to 50 kg live weight) with the isotope dilution method. The N-pool of the test animals was labelled with 15N-glycine and 15N-leucine. The TCA-soluble fraction of the blood plasma served as criterion for the labelling level of the N-pool. The results showed a direct connection between N-intake and endogenous N in the chyme of the small intestines. With regard to N-intake, the dependence of endogenous N in the chyme of the small intestines on feed protein could be observed.

Animals↗

[Hepatic coma - experimental study with swine (part 1)].

An acute coma hepaticum was produced in 8 pigs by means of one intraperitoneal dose of thioacetamide. Distinct changes in the behaviour of the animals, changes of the biochemical parameters inclusively the enzyme pattern with a typical lesion pattern of the liver parenchyma and a displacement of the plasma amino acids were shown. All pathological changes in comparison with the normal animal characterize the liver insufficiency after 24 hours as a comatose state. This acute toxic model serves as the base for investigations within the physiology of nutrition about parenteral feeding of L-amino acid mixtures in coma hepaticum. The nearly exclusive hepatotropic lesion degree of thioacetamide is suitable as an experimental model for this purpose.

Acetamides↗

[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↗

[Malabsorption from the surgical viewpoint].

Malabsorption following surgical procedures on the GI-tract happens only in rare cases, such as blindloop-syndrome, short gut-syndrome, internal fistulae and dumping syndrome after partial gastric resection. Pathophysiological background and therapeutical possibilities as well as parenteral nutrition are discussed in detail.

Avitaminosis↗

[The importance of involutively conditioned and conditioned by morbidity alterations of enteral absorption and the nutrition of geriatric patients with obstructive jaundice and carcinomatous diseases (author's transl)].

In case of absorption examinations in younger and advanced age it is necessary to differentiate between involutively conditioned alterations of enteral absorption and those ones conditioned by morbidity. For this purpose the modified D-xylose-absorption test offers itself as a diagnostical remedy. The equivalently characteristic alterations in absorption kinetics of carbohydrates in cases of the occurrence of an obstructive jaundice, in patients in the stage of generalisation of carcinomatous disease and in the elderly may be demonstrated by the modified D-xylose-Test.

Aged↗

[Current state and perspectives of the use of the 15N-tracer technic in gastroenterologic studies].

The importance of 15N as tracer in medical research is increasing. Since 1965 many results were obtained in cooperation of surgeons (Surgical clinic of Karl-Marx-University; Bezirkskrankenhaus St. Georg, Leipzig) and coworkers of Central Institute of Isotope and Radiation research. Using 3 test models (15N-labelled amino acid solution, permanent infused; 15N-labelled glycine, given as one single dose; 15N-labelled casein, oral given) healthy persons, patients in stress condition and after gastric operations and rats after performing several types of gastric operations were studied. Possibilities of calculations with mathematical models are shown.

Amino Acids↗

[Enteric resorption of an oral, balanced synthetic diet (Berlamin). Clinical experimental study using the modified D-xylose resorption test].

Oral feeding administering a balanced synthetic diet (defined diet, space diet) is increasingly used in clinical practice. the influence of this completely ballast-free and total absorbable diet on the function of the small gut ist nearly unknown. By means of the modified D-xylose-test a reduction of the D-xylose resorption could be stated. The degree of this reduction is without clinical importance.

Aged↗

[Enteral resorption and tumor cachexia].

The rapid loss of the body weight of oncological patients in the advanced stage of the carcinomatous disease is caused by numerous pathophysiological mechanisms. With the help of the modified D-xylose absorption test was investigated which value have disturbances of the enteral absorption in the complex of causes for the development of a tumour cachexia. For the patients in the stage of generalisation of the carcinomatous disease clear disturbances in the enteral food intake could be proved in contrast to patients with carcinoma without general tumour symptomatology and healthy persons. The influence of chemo- and radio-therapy on the enteral absorption of patients with carcinoma was discussed. The forced alimentation of oncological patients with unspezific tumour symptoms must be regarded as a firm constituent in the treatment of patients with carcinoma.

Cachexia↗

[Postoperative small intestinal absorption after cholecystectomy].

The postoperative resorption in the small intestine after cholecystectomie was found out by means of the modified D-xylose resorption test on the 2-th, 4-th, 6-th an 8-th postoperative day for 14 patients. The velocity and the dimension of the enteral resorption of D-xylose was lower in the immediate postoperative phase. The dimension of the D-xylose resorption was normalized on 4. p. o. day and obtained the preoperative starting-value on the 8-th postoperative day. The myoelectrical activity of the small intestine normalized in a shorter time after cholecystectomy than the enteral resorption. A formal parallelism consists between the normalisation of the motoric activity of the stomach and the xylose-resorption in the immidiate postoperative phase. For the small intestine resorption in the postoperative phase completely clarified and required further investigations. The influences of electrolyte displacement and disturbances of the microcirculation in the postoperative period in the small intestine resorption were discussed.

Adult↗

[Postoperative intestinal absorption in old age (author's transl)].

The function of intestinal absorption was analysed in elderly patients before and after cholecystectomy by the help of the modified D-xylose-absorption test. A characteristic dependence upon the age for the process of intestinal absorption was demonstrated in the elderly not only preoperatively but also postoperatively. The effective intestinal absorption of D-xylose normalized postoperative by in freshly operated older patients more slowly than in younger ones.

Aged↗

[Intestinal absorption in the short-bowel syndrome].

An extreme diminution of the absorption surface by resection or exclusion of the small intestine leads to the clinical picture of the short-intestine-syndrome. The absorption effect of the proximal small intestine can be exactly established with the help of the modified D-xylose-test. On the basis of three typical examples the high evidence of this functional test can be demonstrated. The pathophysiological principles of the intestinal adaptation after by-pass-operations and resections of the small intestine are discussed.

Crohn Disease↗

[Intestinal absorption in the elderly (author's transl)].

The extent of intestinal absorption and malabsorption may be exactly stated by means of the method "generalized absorption". According to first-hand examinations an alteration of absorbing kinetics of D-xylose dependent on age could have been demonstrated. The velocity of absorption decreases in the elderly and the general absorbing process are prolonged. The extent of absorption restriction in the elderly are under physiological circumstances without clinical value. The health elder man disposes of the same power for a complete absorption of an offered substrate like the younger one. An increasing of cases with a malabsorption in the age may be explained by a increased multmorbidity in the elderly.

Adolescent↗