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Dive into the research topics where Klaus Wayss is active.

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Featured researches published by Klaus Wayss.


European Journal of Cancer | 1979

Pretherapeutic detection of tumour resistance and the results of tumour chemotherapy

Manfred Volm; Klaus Wayss; M. Kaufmann; Jürgen Mattern

Abstract A short-term in vitro test is described which can be used to detect proliferation-dependent and induced tumour resistance to cytostatic agents. The test involves incubation of tumour cell suspensions with cytostatic agents for short periods. The resulting effects on nucleic acid metabolism are measured using radioactively labelled precursors of DNA or RNA. The Walker carcinosarcoma and a neurosarcoma respond differently to treatment with adriamycin, in accordance with the relative growth rates of the tumours. This differential sensitivity of the tumours to adriamycin can also be detected in the test. Similarly, an induced resistance to adriamycin which was developed in the Sarcoma 180 was also found using the test, as was cross resistance to other cytostatics. Human lung and ovarian carcinomas which were only slightly inhibited by adriamycin in vitro before starting treatment ( inhibition at a concentration of 10 −2 mg/ml or 1.7 × 10 −5 M ) proved to be resistant to chemotherapy in the clinic. Tumours which showed a clear response to adriamycin in the test ( >30% inhibition) showed in most cases remission on clinical treatment with cytostatics. A clear correlation was observed between the inhibitory effects of adriamycin in vitro and the course of clinical therapy even when a combination therapy was used which did not include adriamycin. A significant correlation was also obtained between the inhibition due to adriamycin in vitro and the survival times of the tumour-bearing patients. The short-term test can therefore be used to distinguish between chemoresistant and chemosensitive tumours.


Cancer | 1985

Prognostic significance of DNA patterns and resistance-predictive tests in non-small cell lung carcinoma.

Manfred Volm; P. Drings; Jürgen Mattern; Jaroslav Sonka; Ingolf Vogt-Moykopf; Klaus Wayss

In a cooperative study, 240 surgical specimens of patients with non‐small cell lung carcinomas (NSCLC) were investigated by means of flow cytometry, xenotransplantation to athymic mice and, an in vitro short‐term test for predicting resistance. Aneuploidy was found in 83% of the tumors, and 20% showed more than one aneuploid DNA stemline. Patients with both aneuploid tumors and tumors with more than one DNA stemline had a significantly shorter survival rate than those with only diploid or only one DNA stemline. Patients whose tumors showed a low G0/G1‐cell proportion or a high proliferation pool (S and G2/M‐cell proportion) died earlier. A relationship could not be discerned between growth of tumors in nude mice or establishment of cell lines and the prognosis for the patients. Patients with in vitro‐resistant tumors died earlier under chemotherapy than those with in vitro‐sensitive tumors. Patients treated by radiation survived longer if the tumors were resistant in vitro. Thus, DNA patterns and in vitro short‐term tests for predicting resistance represent useful tools for prognostic evaluation of patients with NSCLC.


Journal of General Virology | 1991

Activation of latent papillomavirus genomes by chronic mechanical irritation.

Michael Siegsmund; Klaus Wayss; Eberhard Amtmann

The skin of animals of a laboratory strain of Mastomys natalensis carrying endogenous, latent papillomavirus genomes was irritated by scratching with glasspaper. Hyperproliferation of the epidermis and amplification of viral DNA followed this treatment, and in approximately 27% of the animals virus-producing papillomas were induced.


Journal of Cancer Research and Clinical Oncology | 1975

Sensitivity Tests of Tumors to Cytostatic Agents

Manfred Volm; M. Kaufmann; Jürgen Mattern; Klaus Wayss

With series of transplanted tumors, the activities of different cytostatic agents which directly influence the metabolism of nucleic acids (Actinomycin D, adriamycin, daunomycin, 5-fluorouracil, procarbazine, trenimon) was measured by determining 3H-uridine incorporation in short-term (3 hrs) incubations of tumor cell suspensions. Data obtained could be used to predict the response of each tumor to particular cytostatic agents in vivo. The activities of the cytostatic agents as determined using long-term tissue cultures (time of exposure of tumor cells to cytostatic agent 48 hrs were comparable to those obtained with the short-term test. In long-term cultures, determination of cell numbers gave results similar to those obtained by morphological evaluation. In the short-term test, differing sensitivities of tumors to cytostatics could be detected. Bei verschiedenen Transplantationstumoren und bei verschiedenen direkt auf den Nucleinsäurestoffwechsel wirkenden Cytostatica (Adriamycin, Actinomycin D, Daunomycin, 5-Fluorouracil, Procarbazin und Trenimon) können die In-vivo Therapieergebnisse durch eine Kurzzeit-Testung von Zellsuspensionen (Einwirkungszeit der Cytostatica 3 Std) mit dem Nucleinsäurevorläufer 3H-Uridin vorausgesagt werden. Die Wirkung der Cytostatica in der Langzeitkultur (48 stündige Einwirkung der Cytostatica auf Gewebekulturzellen) sind mit den im Kurzzeit-Test erzielten Wirkungen identisch. Dabei zeigen die Zellzählung und die morphologische Auswertung bei der Langzeitkultur entsprechende Ergebnisse. Im Kurzzeit-Test können verschieden empfindliche Tumoren erfaßt werden.


European Journal of Cancer | 1977

Effect of synchronization on chemotherapy of solid transplanted tumours

Manfred Volm; Lieselotte Krieg; Jürge Mattern; Klaus Wayss

Abstract A partial synchronization can be induced in the rapidly growing Walker carcinosarcoma and the slowly growing neurosarcoma of the rat by 6 applications of hydroxyurea ( 50 mg/kg of body weight) at intervals of 1.5 hr . When the block is removed, an increase in the rate of DNA synthesis is observed after 3–5 hr ( 3 H-thymidine incorporation, labelling index), which is followed by an increase in the mitotic rate. In order to test whether the effect of therapy with cytostatic agents can be increased by synchronization, different cytostatics were applied at various times after partial synchronization. The times of application were chosen in such a manner that different cell cycle phases were exposed to the action of the cytostatics (G 1 , S, M). The influence of treatment on tumour size, tumour growth and survival time was measured. A strong dose-dependent reduction in tumour growth after cyclophosphamide treatment was similar for both synchronized and non-synchronized animals. Also the growth inhibiting activity of adriamycin was not increased by partial synchronization. This lack of any improvement in the results of therapy using cyclophosphamide and adriamycin is explained by the non-specificity in the mode of action of these substances with regard to the various cell cycle phases. If hydroxyurea, which acts specifically during the S-phase, is used as a therapeutic agent, an improvement in the results of the therapy is obtained by prior synchronization ( 1, 3 and 4 hr after partial synchronization). Analogous results were obtained with cytosine arabinoside and vincristine, substances which also act predominantly on the S-phase cells.


Journal of Molecular Medicine | 1976

Clinical correlates of in vitro effect of adriamycin on advanced lung carcinoma.

Jürgen Mattern; M. Kaufmann; Klaus Wayss; M. Volm; M. Kleckow; M. Mosthaghi; I. Vogt-Moykopf

ZusammenfassungEs wurde die Wirkung von 1,38×10−5 molar Adriamycin auf den 3H-Uridineinbau an Zellsuspensionen von 25 menschlichen Lungentumoren untersucht und mit dem Therapie-Erfolg in der Klinik in Beziehung gesetzt. Alle Tumoren mit einer Uridineinbauhemmung in vitro von mehr als 40% waren auch in der Klinik auf eine Behandlung mit Adriamycin sensibel.SummaryThe effect of 1.38×10−5 M adriamycin on tritiated uridine incorporation was studied after 3 hours treatment of suspensions of 25 advanced human lung carcinomas in vitro. The results were correlated with the responses to clinical therapy. All tumours which showed an inhibition of uridine incorporation in vitro of more than 40% were also sensitive to clinical treatment with adriamycin.


Virchows Archiv B Cell Pathology Including Molecular Pathology | 1981

Chemical carcinogenesis by the two-stage protocol in the skin ofMastomys natalensis (Muridae) using topical initiation with 7,12-dimethylbenz(a)anthracene and topical promotion with 12-0-tetradecanoylphorbol-13-acetate

Klaus Wayss; Denis Reyes-Mayes; Manfred Volm

SummaryThe long-term (34 weeks) topical administration of 7,12-dimethylbenz(a)anthracene (DMBA) to the skin of male and femaleMastomys induced a broad spectrum of benign and malignant tumors in all animals treated. In a two-stage carcinogenesis experiment with topical initiation with DMBA and topical promotion with TPA, 50% of the animals developed both benign and malignant skin tumors. In general, benign tumors occurred between weeks 15 and 25, whereas malignant tumors were seen 40 weeks after initiation. In contrast to the situation in Mus musculus, the benign tumors consisted mainly of keratoacanthomas instead of fibroepitheliomas. In the non-initiated, TPA-treated, control group four benign and four malignant tumors were seen, whereas animals of the DMBA-initiated, acetonetreated control group were free of tumors. The promotion of virus transformed cells with TPA is discussed.ZusammenfassungDie topische Applikation von 7,12-Dimethylbenz(a)anthrazen (DMBA) auf die Haut von männlichen und weiblichenMastomys über 34 Wochen induziert ein breites Spektrum von benignen und malignen Tumoren in allen behandelten Tieren. In einem Zweistufenexperiment zur Carcinogenese mit der topischen Initiierung mit DMBA und einer topischen Promotion mit TPA entwickelten 50% der Tiere benigne und maligne Hauttumoren. Gewöhnlich traten die benignen Tumoren zwischen der 15. und 25. Woche auf, während maligne Tumoren 40 Wochen nach der Initiierung gefunden wurden. Im Gegensatz zu den Verhältnissen bei der Maus (Mus musculus) traten anstelle von Papillomen als benigne Tumoren hauptsächlich Kerato-Akanthome auf. In der nicht initiierten nur mit TPA behandelten Kontrollgruppe wurden vier benigne und vier maligne Tumoren beobachtet, während die mit DMBA initiierte und mit Aceton weiterbehandelte Kontrollgruppe frei von Tumoren war. Die Promotion von virustransformierten Zellen mit TPA wird diskutiert.


Cancer Chemotherapy and Pharmacology | 1980

Therapy of solid Walker carcinosarcoma 256 with bleomycin after synchronization with hydroxyurea

Manfred Volm; Jürgen Mattern; N. Weber; Klaus Wayss

SummaryRats with the solid Walker carcinosarcoma 256 were synchronized with hydroxyurea (6×50 mg/kg or 1×300 mg/kg body weight) and treated with bleomycin (32 mg/kg body weight) at different time points thereafter. Bleomycin clearly affects Walker carcinosarcoma cells at the G1/S boundary or in S-phase. The improvement in the results of bleomycin therapy after pretreatment with hydroxyurea can mainly be accounted for by the synchronization of the tumour cells.


Archive | 1997

Peliosis Hepatis, Rodents

Peter Bannasch; Klaus Wayss; Heide Zerban

Macroscopically, peliosis hepatis is best visible at the surface of the liver. The lesion is seen as blood-filled, thin-walled cavities projecting above the liver surface (Fig. 127). The blood-filled spaces stand out clearly as dark areas against the otherwise brown liver tissue. Large peliotic lesions may also be identified at the cut surface. Frequently, however, it is extremely difficult or even impossible to detect peliosis with the naked eye after the animal has died spontaneously under conditions with a weak blood supply to the liver. When the liver is removed from anesthetized animals after laparotomy, peliosis is readily visible only as long as the liver is connected with the blood circulation, but usually becomes invisible when the blood is lost during removal of the organ.


Archives of Gynecology and Obstetrics | 1974

Cytostaticawirkungen auf Kurzzeit-(3H-Uridineinbau) und Gewebekulturen (Zellzahl) menschlicher Tumoren

Jürgen Mattern; Klaus Wayss; Manfred Volm

SummaryThe previously established correlation between cell counts in tissue cultures and3H-uridine incorporation in cell suspensions on treatment with various cytostatic agents has also been shown to be applicable to 2 human ovary carcinomas. The clinical importance of these results is discussed.ZusammenfassungDie an Tiertumoren nachgewiesene Korrelation der Cytostaticawirkungen zwischen der Zellzahl bei Gewebekulturen und dem3H-Uridin-Einbau an Zellsuspensionen ließ sich auch an 2 menschlichen Ovarialcarcinomen bestätigen. Die Bedeutung für die Klinik wird diskutiert.

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Manfred Volm

German Cancer Research Center

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Jürgen Mattern

German Cancer Research Center

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M. Kaufmann

German Cancer Research Center

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C. Tasca

Heidelberg University

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Eberhard Amtmann

German Cancer Research Center

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Jaroslav Sonka

German Cancer Research Center

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Jochen Schuhmacher

German Cancer Research Center

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D. Haag

German Cancer Research Center

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Denis Reyes-Mayes

German Cancer Research Center

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