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Biomedical subjects

P G Reitnauer

Publications and source records attributed to P G Reitnauer.

At least 37 records · Page 2Linked to original sources
PubMed1982

[Thrombocyte aggregation in overacidification and hyperthermia].

Platelet aggregation was measured in rat plasma at pH values between 6.0 and 8.0 at temperatures, of 21 degrees, 37 degrees and 43 degrees C, respectively, and under aerobic and anaerobic conditions. Platelet aggregation inhibition was predominant at neutral and weakly acidic pH values. At 37 degrees C, aggregation and desaggregation were markedly accelerated as compared to 21 degrees C. In contrast, platelet aggregation at 43 degrees C was not or at most insignificantly increased in comparison to 37 degrees C-Oxygen depletion had no measurable effect. It is concluded from the results obtained that the microcirculation inhibition detected in rats and clinically utilized in the Cancer Multistep Therapy (tumor acidification plus hyperthermia) is highly likely not mediated by platelet aggregation.

Acidosis↗
PubMed1981

2-Cyanoethyl urea and its derivatives as potential immunostimulants in experimental cancer therapy.

Since a few years the class of 2-cyanoaziridines has been investigated thoroughly in terms of their immunomodulating ability. In this paper it will be exemplified by 2-cyanoethyl urea (CEU), the open-chain cleavage product of 1-carbamoyl-2-cyanoaziridine, that derivatives failing the three-membered aziridine ring can also act as immunostimulants. CEU elevates the number of leukocytes and lymphocytes in the circulating blood of rats over a long period of time and stimulates humoral and cellular immune reactions in mice as was shown by estimation of plaque-forming spleen cells and measurements of footpad swelling. Since CEU is very low toxic, even in heavy doses, its use in clinical trials seems to be justified for improving immune parameters in human cancer patients.

Adjuvants, Immunologic↗
PubMed1981

[The elevation of the leucocyte and thrombocyte counts produced by a thyme extract in the peripheral blood as compared to that caused by 2-cyanoethylurea (author's transl)].

A thyme extract, the preparation of which is described, produced a considerable stimulation of leucopoiesis and also an elevation of the thrombocyte count in the blood. In a comparative trial, the immunopotentiator 2-cyanoethylurea (BA1-4) has been found to be even more effective. The elevation of the leucocyte count is of importance not only to the various possibilities of immunostimulation, but also directly, in connexion with an elevation of the thrombocyte count, to the tumour-damaging process in the cancer multistage therapy, due to the promotion of the selective haemostasis set up on this occasion in the tumour tissue. The activation of immunological processes by intensive variants of the oxygen multistage therapy (O2-MT) increases in particular the efficiency of immunopotentiators so the latter should be used, in connexion with O2-MT, in any cancer therapy.

Animals↗
PubMed1980

[Photoelectronic recording of Evan's Blue influx into the blood vessels of tumors with selectively evoked hemostasis as compared to healthy tissue. Retardation of dye influx as a criterion of microcirculation inhibition (author's transl)].

The method of relative microcirculation measurement using Evan's Blue was further improved and results on applying this method to tumors treated with the Cancer Multistep Therapy (CMT) are reported. The microcirculation of these tumors decreased irreversibly below 1% of the value of healthy tissue. The strong, selective inhibition of microcirculation corresponds practically to the separation of the tumor from the organism. Recorded curves demonstrate that this strong inhibition can be achieved neither by hyperthermia nor by hyperglycemia alone, but only by combination of these both steps.

Animals↗
PubMed1979

[Tumor hyperacidification through glucose infusion enhanced by local hyperthermia (author's transl)].

Local tumor hyperthermia (42--43 degrees C) during moderate whole body hyperthermia (40 degrees C) and hyperglycemia (5 . 10(-3) g ml-1) led to an amplification of tumor hyperacidification of deltapH = 0,47 +/- 0,19 In 12 from 20 animals. As cause of this phenomenon the stimulation of glycolysis by temperature increase (van't Hoff's law) and the stop of microcirculation by hyperthermia plus decrease of erythrocyte flexibility was discussed 5 tumors regressed totally.

Animals↗
PubMed1978

[Manipulated hyperacidification of autochthonous tumors].

Measurement on 3,4-benzopyrene- and methylcholanthrene-induced tumours of the rat (and mouse) showed that the multiple established manipulated hyperacidification of transplantation tumours to values about pH 6 is possible also on autochthonous tumours.

Animals↗
PubMed1978

[The time lapse of the cytostatic effect of ifosfamide].

The time lapse of the effect of ifosfamid on the solid DS carcinosarcoma has been studied using 204 Wistar rats. The main results and the conclusions are as follows: 1. The transplantability of the tumor is abolished two hours after the i.v. application of 180 mg/kg isofamid (cessation of tumor cell proliferation). 2. Yet, the tumor tissue to be grafted is not damaged thoroughly by this treatment. It is possible that the still viable tumor cells were killed by the non-suppressed immune system of the recipients. 3. As determined by trypan blue dye exclusion and registration of glycolytic activity, the main part of tumor cells remains viable. As lately as 4 days after the therapy 80% of the cells incorporate trypan blue and the glycolytic activity is inhibited in the order of 80%. 4. It is to be expected that within two hours, a period sufficient for proliferation inhibition of tumor cells, only 30% of the active form of the drug administered can be found in the tumor. In this context the toxification (activation) kinetics of ifosfamid is discussed and an optimized, programmed infusion is considered. 5. The treatment with ifosfamid does not affect at least up to the third day the tumor hyperacidification attainable by a long-lasting glucose infusion.

Animals↗