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Biomedical subjects

U Bicker

Publications and source records attributed to U Bicker.

At least 37 records · Page 2Linked to original sources
PubMed1985

The influence on the formation of unstable haemoglobin by the immunomodulating 2-cyanaziridines azimexone and BM 41.332 in mice.

Azimexone causes in mice the formation of unstable haemoglobins after a single dose of 20 mg/kg. BM 41.332, another immunomodulating drug of the 2-cyanaziridine class, induces these unstable haemoglobins only after a single oral administration of 500 mg/kg. Subsequently to the formation of unstable haemoglobins we observed a development of Heinz bodies. These effects of the 2-cyanaziridines were elicited neither by methaemoglobin formation nor by an impairment of the components protecting haemoglobin against oxidation (G6PD, catalase, glutathione). The elimination of the altered haemoglobin in the spleen could be followed by measurement of the rise in the iron content of the spleen.

Adjuvants, Immunologic↗
PubMed1984

Treatment of autochthonous rat colonic adenocarcinomas with a thioether-lysophospholipid derivative in mono- and combination chemotherapy.

In 361 Sprague-Dawley rats autochthonous colorectal carcinomas were induced by intrarectal application of the carcinogen AMMN. Tumor-bearing animals were treated with a synthetic thioether-lysophospholipid (TLP) derivative and in combination chemotherapy with 5-fluorouracil (5-FU) and carmustine (BCNU). There was no difference in the survival time of treated and untreated animals. The median large-bowel tumor weight was significantly lower in the TLP/5-FU and TLP/5-FU/BCNU combination therapy groups than in the control groups. Transient hepatotoxicity was observed in the high-dosage (50 mg/kg body weight twice weekly) TLP group. This study confirmed the relative resistance of AMMN-induced colorectal carcinomas to antineoplastic treatment.

Adenocarcinoma↗
PubMed1984

Comparative investigations of various immunoregulatory substances in the delayed type hypersensitivity test of the mouse.

The substances D-penicillamine, auranofin, chloroquine, levamisole, BM 41.332, azimexone, bestatin, methisoprinol (inosiplex), thymosine (fraction 5), indomethacin and cyclophosphamide were examined comparatively in the delayed type hypersensitivity test after oxazolone sensitisation in mice. It was found, that only the basal antirheumatic drugs D-penicillamine, auranofin, chloroquine and levamisole and also BM 41.332 led to a potentiation of the DTH reactions. Methisoprinol, bestatin, azimexone, thymosine fraction 5 and indomethacin had no effect on the DTH, whilst the immunosuppressant cyclophosphamide led to an inhibition of the DTH reaction. It is concluded that this pharmacological model is suitable for screening of new basal drugs for rheumatoid arthritis.

Adjuvants, Immunologic↗
PubMed1984

Investigations on the age-dependence of T-lymphocyte subpopulations and lymphocyte reactivity.

The percentage T-lymphocyte subpopulations were determined with the aid of radioactively-labelled monoclonal antibodies to the antigens of total T-lymphocytes and to suppressor T-lymphocyte surface antigens and the responsiveness of the lymphocytes in the presence of ConA and PHA was investigated in groups of 8 subjects aged either between 20 and 30 years or over 75 years. It was found that there was no difference with respect to the response of the lymphocytes to the plant mitogens ConA and PHA. The percentage of suppressor T-lymphocytes, on the other hand, was significantly reduced in the older subjects, whilst the percentage of total T-lymphocytes did not differ significantly from the percentage in younger subjects. These results are discussed in connection with published data.

Adult↗
PubMed1983

Optimizing the lymphocyte transformation test in whole blood. I. Optimum conditions for thymidine incorporation.

The correlation between mitogen concentration and H3-thymidine incorporation can be described mathematically by a sigmoid dose-response curve. Thymidine incorporation/lymphocyte (Ti/Ly) was calculated to facilitate comparison of results. It was highest at a blood dilution of 1:50, lower at 1:10 or 1:250. Ti/Ly obtained with optimum concentrations of PHA was higher than with ConA. Advantages of this optimized method for whole blood over Ficoll-separated mononuclear cells are the higher Ti/Ly, the smaller quantities of blood required and the lower experimental effort.

Cell Separation↗
PubMed1983

Optimizing the lymphocyte transformation test in whole blood. II. Kinetics of thymidine incorporation.

From the 2nd day of incubation on, the thymidine incorporation per incubated lymphocyte increased exponentially with time. The duration of the exponential growth phase was inversely correlated with the number of cells. Under optimum conditions the average time for the doubling of thymidine incorporation (Ti) was 15.7 h. Ti after 1 day of incubation was taken as an equivalent for the number of proliferating cells. It was estimated that less than 20% of the incubated lymphocytes are stimulated by PHA under optimum conditions. In Ficoll-separated mononuclear cells, the percentage of cells stimulated by PHA was lower than in whole blood; the proliferation rate was not decreased.

Cell Separation↗
PubMed1983

Cytotoxicity of thioether-lysophospholipids in leukemias and tumors of human origin.

Thioether-lysophospholipids inhibited the in vitro incorporation of [3H]thymidine into blasts of 8 leukemias, lymphocytes of 3 chronic lymphocytic leukemias, and cells of 12 different solid tumors of human origin. This effect correlated with trypan blue dye exclusion, which was used to assess cell damage. Scanning electron microscopy revealed severe membrane destruction after incubation with thioether-lysophospholipids. Cytostatic and cytotoxic effects of thioether-lysophospholipids were dependent on dosage and incubation time. Destruction of leukemic blasts was completed with greater than or equal to 5 micrograms/ml after an incubation of greater than or equal to 48 hr, but 10 to 20 micrograms/ml were necessary in solid tumors. Ester-linked 2-lysophosphatidylcholine was ineffective in the same dose range, which points to the requirement of the alkyl moiety in SN1 of the molecule for the antineoplastic properties of lysophospholipid analogues.

Adenocarcinoma↗
PubMed1982

Effect of the immunomodulant 2-cyanaziridine derivative BM 41.332 on adjuvant arthritis in the rat.

2-Cyan-1-[(2-methoxy-6-methyl-pyridin-3-yl)-methyl]-aziridine (BM 41.332), a derivative of the immuno-stimulant group of 2-cyanaziridines, showed a therapeutic action in adjuvant arthritis in the rat. Although it does not possess any direct anti-inflammatory action, BM 41.332 showed activity which differed clearly from conventional antirheumatic agents such as cyclophosphamide, glucocorticoids, levamisole or indometacin.

Adjuvants, Immunologic↗
PubMed1981

Influence of the immunomodulating compound BM 12.531 (azimexone) on radioresistance and granulopoietic colony forming units in mice.

BM 12.531 (azimexone) increases the survival of mice exposed to 650 rad. Levamisole, isoprenosine or aristolochia acid have no effects in this system. After administration of 25 mg/kg azimexone to C57 Bl/6-mice a statistically significant increase in CFUc was found. Maybe this increase in CFUc can explain the radioprotective effect of azimexone.

Adjuvants, Immunologic↗
PubMed1980

Therapeutic effects of BM 12,531 (Prop. INN azimexon).

The antitumor effect of BM 12,531, 2-[2-cyanaziridinyl-(1)]-2[carbamoylaziridinyl-(1)]-propane (Prop. INN azimexon), on L1210 leukemia in mice is described. The immunostimulating compound BM 12,531 can also reduce the acute toxicity of X-irradiation in mice. The most effective doses in these experiments are 1 or 5 mg/kg twice a week, whereas 50 and 500 mg/kg twice a week decrease the therapeutic effect. The mortality of Candida-infected and irradiated mice is also reduced by oral administration of BM 12,531. BM 12,531 has synergistic effects with subtherapeutic doses of chloramphenicol in an experimental E. coli infection in mice.

Adjuvants, Immunologic↗
PubMed1979

Investigations in mice on the potentiation of resistance to infections by a new immunostimulant compound.

BM 12.531, 2-[2-cyranaziridinyl-(1)]-2-[2-carbamoylaziridinyl-(1)]-propane, a new immunostimulant compound, increased the resistance of mice to infection with Candida albicans. Because BM 12.531 had no fungistatic activity in vitro, it is proposed that the therapeutic effect of BM 12.531 is caused by the stimulation of cell-mediated immunity. Administration of cyclophosphamide alone increased the mortality among mice infected with C. albicans and Pseudomonas aeruginosa, but when BM 12.531 was then administered to these animals, the mortality was reduced. Among mice with acute Escherichia coli infection, a synergistic effect of chloramphenicol and BM 12.531 was demonstrated.

Animals↗
PubMed1978

[Biochemical and pharmacological properties of new 2-substituted aziridines. Contribution to experimental tumor research].

A new class of compounds, the 2-cyanaziridines, has immune-modulating properties. This immune-modulation was proved by the influence on the delayed type hypersensitivity reaction, the increase of the lymphocyte transformation by T-cell-specific mitogens ConA and PHA, the increase of phagocytosis of macrophages, the increase of resistance against bacterial, fungal and virus infections and by the influence on various transplantation tumors in mice and rats.

Animals↗
PubMed1978

Animal experiments on the compensation of the immunosuppressive action of cyclophosphamide by 2-[-2-cyanaziridinyl-(1)-]-2-[-2-carbamoylaziridinyl-(1)]-propane BM 12 531.

BM U2 531, the 2-[2-Cyanaziridinyl-(1)-]-2-[-2-carbamoylaziridinyl-(1)-]-propane, the further development of BM 06 002 is able to compensate the immunosuppressive action of Cyclophosphamide and to increase the carcinostatic action of Cyclophosphamide. These properties are demonstrated 1. by a leucocytosis induced after application of BM 12 531 in rats 2. by a quick restauration of leucocyte depression induced by Cyclophosphamide in rats and dogs 3. by an increase of resistance against an infection (candida albicans) in mice 4. by an increase of antitumour effect of Cyclophosphamide against a DS-carcinosarcoma in rats.

Animals↗
PubMed1978

Immunomodulating effects of BM 12.531 in animals and tolerance in man.

BM 12.531, a 2-cyansubstituted aziridine, has interesting therapeutic and immunomodulating effects. Antitumor effects in Meth A sarcoma in mice and an increase in resistance to Candida albicans infection in mice have been found. It was demonstrated that BM 12.531 can modulate the immune system in animals (DTH lymphocyte transformation, etc). It was also shown that BM 12.531 can restore the immune response in animals, where this has been suppressed by cyclophosphamide. In a phase I study in cancer patients it was demonstrated that BM 12.531 is very well-tolerated. A dose-dependent increase was found in the percentage of spontaneous T lymphocytes in cancer patients after the administration of BM 12.531.

Animals↗