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Biomedical subjects

D Gericke

Publications and source records attributed to D Gericke.

At least 19 recordsLinked to original sources

[Early diagnosis saves human lives--on the status of colorectal tumors].

UNLABELLED: Colorectal cancers are on rang 3 of the malignant tumors in men and in women in incidence as well as in mortality. The only method to save more patients with these tumors is the early detection. It is to realize at its best by combination of digital rectal examination (DRE), testing for blood in feces and sigmoidoscopy. About DRE nothing is to discuss. The lack of a method without a high percentage of false negative and false positive results is the main problem of testing blood in feces. But the existing methods have to be used until more effective ones will be developed. Method no 3 is the sigmoidoscopy with the new generation of flexible instruments. Doctors have to prefer them because their use is easier, more informative and better tolerable for patients as the old rigid rectoscops. An additional method to evaluate the tumor expansion during surgical treatment is the endoscopic ultrasound examination. It enables the surgeon to look through the colorectal wall for evaluation of the tumor-spreading. There is no doubt, that the surgical treatment is the most effective. It can save around 90% of tumor patients if the tumor is detected in an early stage. The results of chemotherapy are not convincing at all. 5-fluorouracil (5-FU) seems to be the most effective but not curing drug, possibly in combination with immunemodulators. IN CONCLUSION: Colorectal cancer, early detection is the key. If the patient, the practicien and the surgeon will have this in mind, 50,000 pats with colorectal cancer more could be saved this year in the USA. Similar results should be possible in our country also.

Colorectal Neoplasms

[Microbiological short-time tests for the evaluation of mutagenic potential of chemical substances].

During the last 20 years it became much more interesting to test new chemicals as fast as possible for their carcinogenic potency. Therefore new test models were developed. Mutagenicity seems to be one sign for carcinogenicity. Therefore test systems using microorganisms were studied which are influenced by mutagenic substances. These systems are described, first of all the Ames-Test, using revertants of Salmonella typhimurium, secondly the Escherichia coli system deficient of DNA-polymerase A (DNA-Pol A-). The yeast Saccharomyces cerevisiae was introduced some years ago and finally the Neurospora crassa system serves as an additional test to define exactly the localisation of mutations. The tests and their problems are discussed.

DNA Polymerase II

[Possibilities of immunologic management of Brown-Pearce carcinoma in rabbits].

The efficacy of the active specific immunotherapy and immune prophylaxis against the Brown Pearce carcinoma in rabbits was tested. The tumor cells taken as antigens were either untreated or treated with Mitomycin C combined or not with vibrio-cholerae-neuraminidase. The immune prophylaxis using tumor cells prepared this way proved to be very effective. In contrast, immunotherapy of rabbits with tumors was not effective, even when immunization was started directly after transplantation. Possible mechanisms were analyzed in-vitro and in-vivo assays. The cellular reactivity of sensitized spleen cells was positive, the humoral reaction was weaker. This kind of reaction could only be demonstrated with tumor cells pretreated with vibrio-cholerae-neuraminidase. The findings shall only be discussed with respect to the possible causes of ineffective immunotherapy.

Animals

Morphology of the urinary bladder following long-term experimental irritation of the urothelium.

10 female beagle whelps received an artificial urinary calculus (1.5 ml of a rapidly polymerizing methyl-methacrylate) by means of a transurethral procedure. The X-ray, cytological, endoscopic and bioptic findings were followed in a long-term experiment. After a period of 61 months, precancerous urothelial changes (n = 1) and invasive urothelial microcarcinomas were found (n = 2). Typical changes from earlier controls were pseudopapillary follicular cystites. Chronic irritation of the urothelium is shown to be an important factor in the pathogenesis of urinary bladder carcinoma. Decisive is the length of the period of irritation rather than the actual material used in making the pellet.

Animals