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Biomedical subjects

P Otto

Publications and source records attributed to P Otto.

12 recordsLinked to original sources
PubMed1979

Quantum chemical calculations of model systems for ascorbic acid adducts with Schiff bases of lysine side chains: possibility of internal charge transfer in proteins.

Ab initio self-consistent field calculations for neutral and cationic ascorbic acid and model compounds have been performed. Furthermore, the bicyclic addition products of alpha-hydroxytetronic acid with methylglyoxal and with the Schiff base formed between methylglyoxal and methylamine have been calculated, again in their neutral and cationic forms, respectively. The results indicate that the investigated cations can act as strong electron acceptors. With the help of space-filling molecular models it has been demonstrated that such conformations of the Schiff base formed between the primary amino group of lysine side chains in proteins and the ascorbic acid methylglyoxal acetal are possible in which the lactone carbonyl group comes near to the N atoms of the peptide groups, so that charge can be transferred between these subunits.

Ascorbic Acid↗
PubMed1977

[Hemoccult tests of the stool at the time of preventive gynaecological examination (author's transl)].

From January 1, 1977 on, the test for occult blood in the stool becomes, by law, part of routine preventive checkups in order to detect carcinomatous and precancerous lesions of the colon. The effectiveness and practical use of the hemoccult test in the routine gynaecological annual checkup was tested. From October 1975 to June 1976 the test was done in 1,017 women at the time of the preventive gynaecological examinations. The patients received three hemoccult test sachets. They contained guayac resin on filter paper. The stool sample is placed on the filter paper and later tested with peroxide. The patients were informed about the test. The high interest of the patients in the test was exemplified by the high return rate of 80.7%. In 29 patients at least one hemoccult test was found to be positive for a rate of 3.53%. In one of the 821 patients who returned the test a carcinoma of the rectum was discovered which was too high for digital rectal examination. An optimal test is obtained when a stool sample is placed on the filter paper on three consecutive days. When a test is positive the patient is subjected to rectal digital examination, sigmoidoscopy and air contrast barium enema. If the source of bleeding cannot be detected in this manner a coloscopy is done. If the patient followed a diet prior and during the test the rate of positive tests of 3.53% was not increased compared to the group without dietary measures. A special diet prior and during the test is therefore not necessary. The above study shows that the inclusion of the hemoccult test in preventive examinations is a rational extention of preventive testing. Combined with gynaecological preventive examinations, the additional testing for precancerous and carcinomatous lesions of the colon is of additional preventive value for the health of the women.

Adult↗
PubMed1977

[Endoscopy and polypectomy for the early detection of carcinoma of the rectum and the colon (methods, significance, and limitations) (author's transl)].

The possibilities for the early detection and prophylaxis of colorectal carcinoma have been considerably increased by the endoscopic examination of the rectum and the colon via rectoscopy, sigmoidoscopy, and coloscopy combined with a coloscopic polypectomy. The routine use of these examinations was, however, impossible for reasons of personnel, patient psychology and cost. The risk groups need to be selected. To do this, the occult blood test (included since January 1, 1977 in the routine cancer detection examination) is used to demonstrate the presence of occult blood in fecal matter. The endoscopic examination of the colon could be included in the checkups for members of those groups selected. The 60% to 70% accuracy in detecting colorectal carcinoma with rectoscopy is only theoretical. The rate of early detection can be increased only if the rectoscopic technique is expanded by incorporating flexible instruments which are now being developed. High coloscopy should be attempted only after a double-contrast enema has been administered. A biopsy should be made of endoscopically diagnosed polypoid lesion; polyps should be excised in toto. Only then is it possible to make any statements regarding the histomorphology of the total structure. For a focal carcinoma, endoscopic polypectomy is not only a diagnostic procedure but also a curative-therapeutic procedure and, at the same time, an effective prophylaxis against carcinoma.

Colonic Neoplasms↗
PubMed1976

[Diagnostic procedures in congenital dilatation of the bile ducts (author's transl)].

A report is given of 29 cases with congenital dilatation of the bile ducts, and the value of different diagnostic procedures is discussed. Histology in combinations with clinical symptoms allows the diagnosis in cases with microhamartoma or with congenital fibrosis of the liver. Sonography is the most important procedure in the diagnosis of cysts of the liver (solitary cysts or polycystic conditions); it may be complemented by peritoneoscopy if diagnosis cannot be established with certainty by echogramm. If segmental dilatation of intrahepatic bile ducts (Caroli's disease) is suspected, intravenous cholangiography ought to be the first diagnostic step. A more reliable diagnostic procedure is endoscopic retrograde cholangiography (ERC) in theses cases; if ERC does not help, percutaneous transjugular cholangiography may be indicated. In establishing the diagnosis of cysts of the choledochus and of intra- plus extrahepatic dilatations of the bile duct systems sonography ought to be used in the first place; the method of choice in these latter conditions however is the ERC.

Bile Ducts, Intrahepatic↗
PubMed1975

[A comparison of radiology and endoscopy in the diagnosis of gastric and duodenal ulcers(author's transl)].

The results of endoscopy and radiology were compared in 455 patients, 250 with gastric ulcers and 205 with duodenal ulcers. Accuracy of endo- scopy for gastric ulcers was 95% and for duodenal ulcers 92%. Findings were judged on the results of endoscopy. The radiological findings were related to the endoscopic diagnosis and radiological examinations were carried out on out-patients as well as in-patients. 20% of gastric ulcers in out-patients were missed, and 10% of those in in-patients. Of duodenal ulcers, 27% of out-patients and 8% of in-patients were missed. Gastric ulcers missed radiologically were usually small or superficial and situated predominantly in the upper third of the stomach or in the antrum. Duodenal ulcers tended to escape radiological diagnoSIS if they were linear in shape. Improved technique and greater experience of the examiner increased the radiological accuracy significantly.

Diagnostic Errors↗