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Biomedical subjects

M Friedrich

Publications and source records attributed to M Friedrich.

At least 289 records · Page 16Linked to original sources
PubMed1981

The XERG-mammography system: a solution to the dose-quality problem?

The XERG (Xonics-Electron-Radio-Graphy) system is the first ionographic system (High-Pressure-Gas-Iono-graphy) suitable for clinical application which became available for testing. The basic principle, the function and imaging qualities of the XERG system are described and first clinical experiences reported. The XERG mammogram is a transparent X-ray negative image, the image quality of which is characterized by good general image contrast, a moderate edge-effect and a high quantum-noise level but giving an extremely low dose rate (4.5% compared to screenless mammography film). Although the XERG quality is not satisfactory in contact technique, it yields results which are equal in quality, when using a 1.5-fold magnification technique, to the results obtained with screenless film mammography at one-tenth of the dose, and is superior to any commercially available film-screen system. Hence, in our opinion, the XERG mammography system is a step forward towards high-quality low-dose mammography.

Chlorofluorocarbons, Methane↗
PubMed1980

[Clinical findings in thoracal functional disturbances (author's transl)].

Functional disorders of the thoracal motor structures show connections with visceral functions through the different forms of pain symptoms, but also not seldom without these, or else appear as their precursors. By means of conventional examination parameters, corresponding interconnection procedures could be demonstrated and the theoretical models for further discussion of the segmental reflector complexes are substantiated.

Humans↗
PubMed1980

[Reasons for lumbar syndromes after disc operations (author's transl)].

This investigation presents the findings in 105 patients after disc operations who required renewed in-patient treatment mainly because of their resistance to therapy and/or recurrence of the lumbar syndrome. A number of factors were found to be implicated in providing a reason for unsatisfactory results after operations for prolapsed lumbar intervertebral discs. It must be postulated that interfering factors like ligamental pain, restricted movement, participation of the hip, psychological aspects, polyneuropathics and focal occurrence have to be taken into consideration already preoperatively in the diagnosis, indication for operation and therapy. Also with post-operative complaints special alteration must be paid during rehabilitation to those factors quoted above, as well as to direct post-operative complications like inflammation and scar.

Cicatrix↗
PubMed1980

[Physiological importance of the microvilli-bound leucine arylamidase in the final digestion of proteins. III. Exopeptidatic activities of purified microvilli against peptides mixtures in the presence and after the removal of free amino acids].

The exopeptidatic degradation of peptide mixtures by the aminopeptidase of the microvilli is inhibited by the presence of free amino acids. Further degradation occurs after the removal of the free amino acids from the peptide mixture. The amino-acid composition of the remaining residual peptides is a second factor that impedes the complete cleavage of the peptides.

Amino Acids↗
PubMed1980

[Physiological importance of microvilli-bound leucinarylamidase in the final digestion of proteins. 4. Inhibition of microvilli-bound leucinarylamidase by free amino acids].

The microvilli-bound leucine arylamidase is inhibited by certain amino acids. An inhibitory action is exerted by the branched-chain amino acids L-leucine and L-isoleucine and by the aromatic amino acids L-tyrosine and L-phenylalanine with Ki values of 4--6 . 10(-3) M. L-methionine (Ki = 2.5 . 10(-3) M) and its higher homologue L-ethionine (Ki = 1.1 . 10(-3) M) are the most potent inhibitors. Derivatization of L-methionine on the sulphur or the nitrogen atom or the carboxyl group prevents the inhibitory effect just as the D-isomer.

Amino Acids↗
PubMed1980

[Influence of the weather on the course of lumbar syndromes].

Sensation of pain during lumbar syndromes is correlated with weather situations, the definition of which takes into consideration traditional as well as new methods of weather classification. To this end, it was necessary to develop an algesia index for the purpose of defining the subjective pain sensation by classifying it in different groups enabling the application of medico-meteorological statistics. The medical data were correlated with the following meteorological arametes: Weather-phase scheme according to Brezowsky-Ungeheuer; temperature-humidity environment; weather situations for Central Europe; synoptic index cycle; advention of temperature in medium altitudes of the atmosphere; vorticity for cyclogenesis. The following results were obtained: Pain sensation in the lumbar area shows a significant dependence on weather situations. Althoguh singular meteorological parameters are not important, the human body is affected primarily by the sum total of all weather elements.

Back Pain↗
PubMed1980

[A new immersion ultrasound technique for the investigation of the scrotum (author's transl)].

The testes of about 50 patients were examined by ultrasound, using a water immersion technique. Immersion sonography provides an excellent and anatomically detailed demonstration of the male genitalia. Intrascrotal fluid collections, extra- and intratesticular solid lesions and inflammatory processes can be accurately differentiated. The method is suitable for showing the size, shape and extent of a scrotal lesion. In many cases the echo pattern can provide information concerning the pathological changes of these organs.

Genitalia, Male↗
PubMed1980

[Ultrasound examination of the breast. Experience with a high resolution 'real-time'-scanner (author's transl)].

A new high resolution real-time ultrasound scanner for diagnosis of the breast is presented. The scanner is designed for the examination of peripheral blood vessels, all superficial soft-tissue organs, such as the thyroid, breast, salivary glands, testes as for well as pediatric examinations. It is a mechanical linear scanner with electronic and mechanical transducer focusing. Its high resolution as such and also the sonographic appearance of benign and malignant breast lesions are demonstrated, general problems of ultrasound examinations of the breast are discussed. The equipment under evaluation is of considerable value in the differentiation of palpable or otherwise localised breast tumors. It is less useful for a general application in the screening for breast cancer.

Adenocarcinoma, Scirrhous↗
PubMed1979

[Spontaneous solubilization of mcuosal peptide hydrolases in rat small intestine].

In vitro incubations of small intestine preparation lead to the spontaneous release of mucosal enzymes into the incubation medium, due to superficial dissolution and membrane lesions. One-hour anaerobic incubation of everted small intestine segments produces the liberation of from 13% (leucine arylamidase) to 30% (Gly-L-Pro-splitting peptide hydrolase) of the mucosal enzyme activities. Under the conditions of in vivo perfusion, the solubilization rates are from 50 to 80% lower than these values. The tendency to solubilization is only in part reduced to a significant extent by the saturation of the incubation medium with oxygen, but it does not reach the in vivo level. The detectability of membrane-bound and intracellular marker enzymes in the incubation medium permits no conclusions concerning the physiological localization of the released peptidases.

Anaerobiosis↗
PubMed1979

[The value of sonography in evaluation of unilateral nonvisualized kidney (author's transl)].

In a comparative study with 35 patients, sonography, angiography and radiorenograms are investigated on their validity for evaluation of nonvisualized kidneys. In our group of patients, angiography showed an accuracy quota of 97% (34/35) and sonography showed an accuracy quota of 88% (31/35). In 12 patients, the radiorenograms unequivocally show functional loss with the nephrectomy type. Sonography should be used first as a simple noninvasive procedure. It is independent of the remaining renal function and indicates the size of the organ. For hydronephrosis sonography cannot clarify the cause of the urinary stasis in some cases; for this purpose, further examinations are indicated (retrograde pyelography, antegrade pyelography).

Angiography↗
PubMed1979

[Absorption of triglycine, diglycine, glycine or equimolar mixtures of diglycine and glycine in the perfused small intestine of rats].

1. After a wash-out period of 20 min with Krebs-Henseleit-buffer a 20 cm segment of proximal or distal small intestine of nonanaesthesized rats got a bolus infusion of 3 ml either triglycine, diglycine, glycine or an equimolar mixture of diglycine and glycine, respectively, in a concentration range of 20 to 1000 mmol/l glycine equivalents. With 9 ml of a peptide and amino acid free solution the gut was perfused in a single-pass perfusion and the whole fluid recovered was investigated by quantitative thin layer chromatography for triglycine, diglycine and glycine. 2. In the concentration range up to 170 mmol/l glycine equivalents the nitrogen absorption is independent of the substrates perfused. In the highest concentration range an additional increased disappearance of triglycine could be found. This change cannot be observed to the same extent for diglycine, glycine or the mixture of both. In contrast, in the highest concentration range the competition between glycine and diglycine results in a decrease of absorption. 3. The proximal or distal nitrogen absorption of all substrates is similar. 4. In the perfusate the peptide and its splitting products were investigated. 5. Based on the discrepancy between the disappearance of triglycine and the appearance of its splitting products it is assumed. 1. that the transport of intact triglycine is of quantitative importance in the highest concentration range and 2. that in the lower concentration range membrane digestion followed the transport of the splitting products prevails. 6. Extending Ugoley's model for dipeptides three general variations for membrane digestion of tripeptides are proposed. One of this is likely for the triglycine absorption.

Animals↗
PubMed1978

[New development in mammographic technique: Grid mammography (author's transl)].

Reduced scatter through antiscatter grids and improved filmscreen combinations produce definite improvement in image quality with large breasts, as well as a reduction in radiation dose. The problems of soft tissue grid technique are discussed and a new apparatus for this purpose is described. New and improved recording systems, which reduce radiation dose, are analysed and a comparison is made between the quality of grid mammograms and conventional techniques using industrial film.

Breast Neoplasms↗
PubMed1978

[Amino acid composition of non-absorbed peptide fractions in rat small intestines. III. Feeding of wheat gluten and molasses yeast. Essential amino acid content of feces].

The authors investigated the nitrogen content of different fractions and in particular the aminoacid composition of the trichloroacetic acid (TCA)-precipitable and TCA-soluble peptides in the distal small intestine of rats which had been fed experimental diets (nitrogen-free or containing casein, wheat gluten or molasses yeast as a protein carrier). Parallel with this, they determined in growing rats the nitrogen and amino-acid digestibility of molasses yeast and wheat gluten according to the technique of faecal analysis, and studied the amino-acid composition of the faecal protein. Independently of the dietary protein fed, the peptide fractions of the content of the intestine showed an amino-acid composition that was largely similar to that found in case of nitrogen-free diet. The amino-acid composition of the faecal protein is, independently of the dietary protein given, relatively constant and corresponds approximately to the intestinal loss protein. There is agreement between the amino-acid composition of the TCA-precipitable peptide fractions and those of the corresponding faecal proteins. These components seem to be of endogenous origin.

Amino Acids↗
PubMed1978

[Inhibition of aminopeptidase activity of rat small intestine by the tripeptide H-Thr-(O-tert. butyl)-Phe-Pro-OH].

The hydrolysis of L-leucine-beta-naphthylamide and L-leucinamide by leucinaminopeptidase (E.C. 3.4.11.1) from bovine eye lens is inhibited by H-Thr (O-tert. butyl)-Phe-Pro-OH. The inhibitor constants are Ki = 1.5 . 10(-5) M and 0.8 . 10(-5) M, respectively. Both brush border peptidases, leucinarylamidase (E.C. 3.4.11.2) AND TRIPEPTIDASE (E.C. 3.4.11.4), are inhibited to a smaller extent (Ki = 0.8 . 10(-3) M). Mn++-ions activate the cytosolic leucinaminopeptidase but not the hydrolysis of leucinamide by the brush border arylamidase. The inhibition of the cytosolic leucinamidase by the peptide (Ki = 3.5 . 10(-4)) is twice as that of the brush border arylamidase.

Aminopeptidases↗