It has been known that ciprofloxacin augments the humoral and cellular immune systems. The aim of the present study was to determine whether these properties affect the inflammatory response. Adult male rats, ciprofloxacin and pefloxacin were used. The healty rats were treated orally with an equal volumes of ciprofloxacin (50 mg/kg) pefloxacin (50 mg/kg) or distilled water for 10 days. Their effects on the inflammatory response were investigated by testing the formation of formaline-induced edema. The effects of two quinolones were also evaluated on gastic mucus secretion by using the Alcian blue dye binding method and haematological parameters. Ciprofloxacin and pefloxacin showed a significant anti inflammatory activity and decreased the white blood cell count (WBC). However, there was no significant difference in the other haematological parameters. These two quinolones stimulated gastric mucus secretions, but these increases were not statistically significant. These findings suggest that ciprofloxacin and pefloxacin (at 50 mg/kg p.o. doses) possess antiinflammatory activities and are well-tolerated orally. Further detailed investigations are needed to clarify the mechanisms of their antiinflammatory activities

Megakaryocytopoiesis is a complicated phenomenon which involves the proliferation of progenitor cells, formation of a polyploid nucleus, cytoplasmic changes and formation of thrombocytes. It has been suggested that megakaryocytopoiesis resembles erythropoiesis. It is well known that iron is a required element for the proliferation of erythrocytes, lymphocytes and cancer cells but no consensus has yet been reached about its role in thrombocytopoiesis. Although thrombocytosis is generally found in patients with iron deficiency anemia, thrombocytopenia is also observed. Cell surface receptors for transferrin were initially characterized on cells with high iron requirements including hemoglobin producing cells and placental cells. More recently, it was found that transferrin receptors also exist on the other cells. Therefore, we assumed that megakaryocytes may have transferrin receptors and iron may affect the growth of megakaryocytes. We examined the proliferation of rat megakaryocytic cells with the presence of 50, 150, 300 µg/ml iron-saturated transferrin in a plasma clot culture system. According to our preliminary results, iron might not be required for the proliferation of megakaryocytic cells in vitro.

The fact that meningioma shows at least a 2:1 predilection for women over men is considered to be due to endocrinological and paracrine regulation of the development of this tumour. The presence of receptors for the luteinizing hormone releasing hormone (LHRH) in gynaecological cancer permits the use of LHRH agonistic or antagonistic analogues with a direct effect or by the gonado-pituitary axis suppression in the treatment of these tumours. Therefore, the effect of LHRH on meningioma cells is tested in this study. Meningioma cells from three female patients were cultured and LHRH (50 ng/ml) was added to the growth medium daily, for fourteen days. At the end of this period the cells were counted by means of a Coulter Counter. The stimulating effects of LHRH on the increase of the amount of cells in the meningioma monolayer culture were 146% (p < 0.01), 134% (p < 0.05) and 141% (p < 0.05) of the control, respectively, for the three patients.

The presence of the cellular multidrug resistance (MDR1) gene and its product, P-glycoprotein (Pgp), is thought to be a mechanism for the failure of chemotherapy in cancer patients. Calcium channel blockers have been shown to sensitise cancer cells to anticancer drugs by reversing Pgp expression in cell lines. The interactions between anticancer drugs such as carmustine (BCNU), vincristine (VCR) and procarbazine (PCB) and calcium channel blockers such as nimodipine and verapamil on cultured cells of glioblastoma from eight patients were therefore tested. Pgp expression was examined immunohistochemically using C219 monoclonal antibody in cytospin preparation. The cytotoxicity of the drugs was screened using microculture tetrazolium assay. The cells from five patients showed positive immunoreaction for Pgp. Nimodipine showed growth-inhibitory activity against glioblastoma cells at a rate of 16.55-26.88% (P < 0.05), but a similar effect was not observed with verapamil. While antiproliferative effects of BCNU were around 20.91-45.09% (P < 0.05) on the cells from seven patients, VCR was the most effective agent in inhibition of cell growth at a rate of 26.43-48.47% (P < 0.05). The response of the cells from five patients to PCB was from 11.98 to 16.32% (P < 0.05). When used together, nimodipine further enriched cytotoxicity of the anticancer drugs up to 11.14-40.85% (P < 0.05) without relation to Pgp expression. In conclusion, the enhancement of cytotoxicity of anticancer drugs by nimodipine suggests that there might be a synergy between anticancer drugs and nimodipine in the inhibition of glioma cell growth.

The 21-aminosteroids (lazaroids) are a new family of steroid compounds that inhibit lipid peroxidation reactions. They are novel antioxidant agents, which have been shown to have antiproliferative properties on cancer cells and also are thought to prevent free radical-mediated blood-brain barrier damage. In order to understand the effect of lazaroids on glioma, we tested U-83836E and U-74389G at doses ranging between 0.1–100 μM on primary cultures of gliobiastoma multiforme from three patients, rat C6 glioma cell line, and 5th subculture established from one of the patients. The effects of both compounds on cell proliferation were determined using 3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) colorimetric assay U-83836E in the primary cultures was found to have 50% inhibitory concentrations (IC50) of 6.30, 6.75 and 6.50 μM, respectively. The IC50 value of U-74389G was calculated as 91 μM in only one of the patients. On C6 glioma cells, while the IC50 of U-83836E was 45 μM, U-74389G showed no cytotoxic effect. On the 5th subculture, U-83836E had an IC50 of 37.5 μM, but the cytotoxic effects of U-74389G was less than in that of the primary culture. In conclusion, these compounds were found to be more cytotoxic in primary culture than the cell lines and there were also differences between their members in the inhibition of cell survival.