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Biomedical subjects

M Friedrich

Publications and source records attributed to M Friedrich.

At least 307 records · Page 17Linked to original sources
PubMed1977

[Amino acid composition of unresorbed peptide fractions in the contents of the distal part of rat small intestine. 1. Nitrogen-free diet and diets with casein, sunflower protein isolate and defatted sunflower seeds].

After feeding with protein containing diets the protein quantity increases in the aqueous supernatant (U1), in the trichloracetic acid soluble (U2) and precipitable (S2) fractions of the content of the distal part of the small intestine of rats. Independent of the dietary proteins the amino acid composition of both fractions (S2 and the peptides from U2) is similar in relation to protein-free feeding; a similarity with the amino acid composition of the dietary proteins doesn't exist. In relation to fraction S2 the peptides of fraction U2 show anording to the higher content of amino acids, which are difficult to liberate by protein cleavage, a high proteolytic degradation.

Amino Acids↗
PubMed1977

[Amino acid composition of the unresorbed peptide fractions of the distal part of the small intestine in rats. II. Feeding of field-bean protein isolate with and without the addition of dialdehyde starch and of protein texturates from it].

Rats were fed diets containing 20% protein in the form of casein, protein isolate from sunflower seeds, protein isolate from field beans, model protein texturate made from field-bean protein isolate or model protein texturate made from field-bean protein isolate treated with dialdehyde starch and a nitrogenfree diet. The content in the distal small intestine of the rats was collected 3 hours after feeding, and the amino-acid compositions of the TCA-precipitable and TCA-soluble peptides (after separation of free amino acids) of the content were studied. The comparison of the amino-acid compositions of the two peptide fractions with the respective dietary protein showed no agreement. On the contrary, the comparison of the amino-acid compositions of the two peptide fractions determined after protein-free diet with those found after protein ingestion were in good agreement, independently of the kind of dietary protein. The comparison of the two peptide fractions with one another revealed an increased degree of proteolytic decomposition of the TCA-soluble peptides. As compared to the other protein-containing diets and to the protein-free diet, diets containing field-bean protein caused an increase of TCA-precipitable peptides and an increase of glycine in both fractions. This was also observed in model protein texturates containing only 30% field-bean protein. Treatment with dialdehyde starch produces certain alterations of the basic amino acids and their accumulation in the fractions of undigested peptide.

Aldehydes↗
PubMed1976

[Picture quality and film mammography. I. The physical parameters of the filming system (gradation, sensitivity, definition and granularity) and the effect of exposure geometry (author's transl)].

The physical parameters of three radiographic filming systems used for mammography were analysed (industrial film without screens, lo dose system (Dupont), industrial film with lo dose screens). Their effect on image quality was studied and the influence of the exposure geometry on sharpness and detail was investigated experimentally. Geometrical unsharpness so reduces the difference in definition between screenless industrial film and a film-screen combination that the total unsharpness at the centre of the breast parenchyma of an average breast becomes approximately the same. In particular, recognition of fine detail (microcalcification) is reduced by geometric unsharpness. Final grading of the three film systems is only possible after development of a concept of film quality which takes account of the parameters of the filming system and of exposlre geometry, together with physiological and practical requirements (paper II).

Absorptiometry, Photon↗
PubMed1976

[An analysis of the radiological appearance of osteoplastic metastases and osteitis deformans (Paget's disease) (author's transl)].

The validity of individual radiological signs for the differentiation of osteoplastic bone metastases from osteitis deformans has been investigated quantitatively (103 skeletal metastases from carcinoma of the prostate, 45 cases of Paget's disease, two osteoplastic bone metastases from a carcinoma of rectum and bronchus). The similarities were demonstrated by three cases observed by us. Problems in the quantitative evaluation of the radiographs are discussed.

Aged↗
PubMed1976

[Film quality in film mammography. Article II: Signal/noise ratio of the recording system as a quantitative measure of quality. Final evaluation of recording systems (author's transl)].

During consideration of three film mammographic systems (see article I), the concept of signal/noise ratio is developed as a quantitative measure of film quality. The ability to recognise detail related to detail size, film blackening and exposure geometry was studied for various systems, and the quality profiles are discussed. There is a considerable difference in quality between industrial films without screens and film-screen combinations; however, exposure geometry during mammography has a considerable effect which tends to reduce the difference. Consequently, detail sizes of 200 mu to 1,000 mu (including the majority of mammographic micro-calcifications) are shown about equally well. Contrast for the lo-dose system (D = 1.1) is somewhat less than for adequately exposed industrial film (D = 2.0) or for Cronex 75 m with lo-dose screen (D = 1.5 to 2.0). The lo-dose system (D = 1.1) is 8.6 times more sensitive than Cronex 75 m (D = 2.0), and the system Cronex 75 m with lo-dose screens is 11.6 times more sensitive. Over-exposure with the lo-dose system, contrary to industrial film, rapidly leads to unsatisfactory results (loss of contrast and increased granularity for D greater than 1.5). On the other hand it is often not possible to obtain an adequate exposure (D = 2.0) when using industrial film. For these reasons it is often an advantage to examine large breasts (with considerable geometric unsharpness) and the dense breasts of young women with a film-screen combination (eg. lo-dose system) which requires approximately one eighth of the dose necessary for industrial film. For small or easily compressable breasts (little geometric unsharpness) best results are obtained, using an adequate exposure by employing industrial film; radiation dose it then acceptable. Detailed analysis of the systems has shown that the recording system unsharpness of film-screen combinations in mammography should be reduced.

Female↗
PubMed1975

[Digestion and resorption of proteins].

A survey is given of the ultrastructure of the intestinal epithelial cell, especially of its lumenward membrane. Special attention is paid to the peptidases which are located in the ciliated border and within the cell. The authors deal with the purification of the membrane-bound aminopeptidase which is of importance in splitting dietary peptides and illustrate its specificity by the cleavage of casein. The amino acids which are liberated by peptide splitting have in part aminopeptidase-inhibiting properties. The possible digestion physiological consequences are discussed. In vitro experiments were performed to investigate the composition of the content of the distal part of the small intestine of the rat with regard to its possible dependence on the composition of various dietary proteins. The composition of the peptides of the intestinal content is essentially undependent of the amino-acid composition of the diet. There is no enrichment of certain amino acids. The importance of the resorption of the peptides is also evidenced by resorption studies in which enzymatic hydrolysates of proteins (i.e. peptide mixtures) were confronted with a free amino-acid mixture of the same over-all composition. Taking glycyl-glycine-glycine as a model, the authors demonstrate that, in determined ranges of concentration, tripeptides may in part be resorbed without degradation. Finally, the importance of peptide resorption is evaluated and conclusions are drawn as to further studies on the physiology and physiopathology of digestion.

Amino Acids↗
PubMed1975

[The value of sonography in the diagnosis of renal space-occupying lesions].

1. Sonography achieves an accuracy of 93% (n = 55/59) in the localisation of space-occupying lesions in the kidney. Since the method is somewhat laborious, ultra sound, in the form of a slow B-scan, cannot be regarded as an alternative to radiology with an accuracy of 97% (n = 57/59). 2. For a pathological diagnosis, particularly in the distinction between tumours and cysts, sonography, with an accuracy of 98% (n = 54/55) is markedly better than radiology with an accuracy of 50% (n = 21/42). Sonography is approximately equal to angiography, which has an accuracy of 97% (n = 69/71). 3. Sonography is useful and is indicated for: a) the investigation of non-functioning kidneys, b) patients in whom radiographic contrast media are contra-indicated, and c) for puncture of renal cysts. (F. St.).

Carbuncle↗
PubMed1975

[The intrathoracic rib(author's transl)].

The intrathoracic rib belongs to the group of additional ribs, hence the 'english synonym "supernumerary rib". Two cases are reported. The mode of inheritance could not be established. Knowledge of this rare and bizarre anomaly is important in order to avoid unnecessary treatment (occasionally even a thoracotomy).

Adult↗
PubMed1975

[The effect of scatter on film quality in mammography (author's transl)].

The proportion of total radiation during mammography due to scatter was measured by film densitometry, and was found to average 44% (N = 16). The relationship between the geometry of the scattering object and the distribution of scatter was investigated experimentally. The relationship between gradation, amount of scatter and maximal resolution, as well as contrast, are discussed. The usual collimation and breast compression do not result in any significant reduction of scatter. The use of grids is described, but the technical problems involved have not yet been solved.

Absorptiometry, Photon↗
PubMed1966

Proteolytic and peptidase activities of the jejunum and ileum of the rat during postnatal development.

1. Proteolytic (substrate nitrocasein), tripeptidase (substrate glycylglycylgly-cine) and aminopeptidase (substrate leucyl-beta-naphthylamide) activities were studied in homogenates of jejunal and ileal mucosa of 7-, 10-, 14-, 21-, 35- and 60-day-old rats. 2. Proteolytic activity was practically the same in jejunum of 7-, 10-, 14- and 21-day-old rats, but after day 21 a significant increase was observed. The activity of the ileum changed very little during postnatal development and was always higher than that of the jejunum. 3. Tripeptidase activity was low in the jejunum of 7- and 14-day-old rats, an increase was observed between day 14 and 21, but later no substantial changes were found. There were no changes in the ileum. The activity in the jejunum of 7- and 14-day-old rats was lower than in the ileum, but later the jejunum was more active than the ileum. 4. Aminopeptidase activity had a similar developmental pattern to tripeptidase activity. A low activity was found in the jejunum of 7- and 14-day-old rats, the maximum was in 21-day-old rats and then a decrease was observed, though values for 60-day-old rats were still higher than for 7- and 10-day-old rats. The activity in the ileum was practically the same in all age groups studied except in 14- and 21-day-old rats, where a transient peak was observed.

Aminopeptidases↗