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Biomedical subjects

G Bastert

Publications and source records attributed to G Bastert.

At least 271 records · Page 15Linked to original sources

[Observations on tumor-associated fibrinolysis in human breast-cancer (author's transl)].

In 30 cases of breast-cancer, including 24 primary cases, the tumor-associted fibrinolysis was investigated using agar plate method. In 60% of the tissue sample fibrinolytic activity was found. No activity could be detected in the remaining 40%. There was evidence of a positive correlation between tumor-associated fibrinolysis and tumor size as well as the rate of axilla metastases. Among the fibrinolytic active cases there was a disproporionate number of adenocarcinoma, whereas in the inactive collective the solid and scirrhous carcinoma prevailed. There was no relation between the tumor-associated fibrinolysis and the percentage of tumor cells in the tissue. The firbinolytic inactive tumors showed a better histopathological adaptation to the surrounding tissue than the active ones. There was less small-cell infiltrate in the stroma of the fibrinolytic active tumors than in the inactive cases. No significant difference was found in the form of growth and the occurence of fibre structure. For clinical assessment a longer period of observation and a larger study are necessary.

Adenocarcinoma↗

[In-vitro testing of the sensitivity of mammary carcinoma cells to cytostatic drugs (author's transl)].

In-vitro sensitivity to cystostatic agents was tested in 137 cases of breast carcinoma, with 125 tests being analysable. Inhibition of in-vitro incorporation of 3H-uridine or 3H-thymidine into RNA or DNA of the original tumour cells after incubation with antineoplastic substances was used as the index for the in-vivo sensitivity of the tumour. 30% of the carcinoma cells were sensitive in-vitro, 70% resistant. About 75% of sensitive cancers were sensitive against several agents. Cyclophosphamide proved to be most effective in-vitro: it was tested via 4-hydroxycyclophosphamide or 4-hydroperoxycyclophosphamide. There was a correlation between histological type and in-vitro sensitivity of the cancer, as well as between proliferative activity and in-vitro sensitivity in that proliferation-active tumours were more frequently sensitive in-vitro than proliferation-poor ones. Primary tumours and metastases of the same patient frequently showed different sensitivity. In some cases the development of resistance against cytostatic drugs was demonstrated during treatment. Testing tumours against combinations of cytostatic drugs demonstrated an additive effect of the antineoplastic substances in-vitro.

Antineoplastic Agents↗

[The evaluation of the cyclophosphamide sensitivity of human tumours by determining the incorporation of tritiated uridine and thymidine into the nucleic acids of human tumor cells in vitro in presence of 4-hydroxycyclophosphamide (author's transl)].

A new in vitro assay for screening the sensitivity of human tumour cells against Cyclophosphamide has been developed. While biologically activated Cyclophosphamide was unsuitable because of unpurities in the material, synthetic 4-Hydroxycyclophosphamide was shown to inhibit the incorporation of tritiated uridine and thymidine into the nucleic acids of human tumour cells in vitro. 29 tumours including 14 mammarial carcinomas, 8 ovarial carcinomas and 7 other malignant tumours were tested. While 12 tumours showed a significant and 5 only a slight inhibition of the 3H-uridine incorporation in vitro. 12 tumours showed no effect. Histologically none-differentiated tumours were more sensitive against 4-Hydroxycyclophosphamide as compared with the more differentiated ones. First observations point to 4-Hydroperoxycyclophosphamide instead of 4-Hydroxycyclophosphamide as a more suitable form of activated Cyclophosphamid for the in vitro assay of Cyclophosphamide sensitiveness because of the higher stability and better availability of this compound.

Antineoplastic Agents↗

[Pharmacokinetic investigations of the transfer of antibiotics into amniotic fluid. Part III: Oxacillin (author's transl)].

After intravenous administration of 2 g of Oxacillin to 12 gravidae at the end of their pregnancy short-interval tests were made of the Oxacillin levels in the mothers' serum and -- intra-amnionic catheter in position -- in the amniotic fluid. The following pharmaco-kinetic data were determined: fictitious initial Oxacillin level (79 mcg/ml), elimination constant (1,044 h-1), half-value of elimination (39,88 min), fictitious distribution volume (25,31), distribution coefficient (0,3617 ml/g), total clearance (26,431 l/h) and invasion constant (0,0084 h-1). All given data were statistically confirmed. For the para-placental passage of Oxacillin a permeability factor (chi) of 0,0084 was found. This factor indicates how easy Oxacillin passes trough the fetal membrane into the amniotic fluid. Ampicillin diffuses about 43 times and Cephalotin diffuses about 2,4 times better trough fetal membrane -- permeability factor 0,357 or 0,02 --, probably because of its weaker link to serum albumin. Under our conditions the amnionic levels reached 12 mcg/ml on the average. With 8-12 g Oxacillin daily bactericidal levels in the amniotic fluid are reached.

Amniotic Fluid↗