670 research outputs found
Reversal of doxorubicin and cisplatin resistance in vivo in murine leukemias by the calcium antagonist RO 11-2933
No full textThe ability of RO 11-2933 to modulate in vivo Doxorubicin and Cisplatin antitumor activity has been evaluated in sensitive and resistant P388 and L1210 murine leukemias. A reversal of both Doxorubicin or Cisplatin resistance has been observed when P388/Dx or L1210/CP tumor bearing mice received multiple treatments of the antitumor agent plus 30 mg/Kg of RO 11-2933. No modification of Doxorubicin or Cisplatin effect has been observed in sensitive tumors. The results obtained indicate that RO 11-2933 might represent a promising agent for the reversal of multidrug resistance
PDT and antitumor immunity: the beginnings of the story
No full textThis mini-review reports a brief description of the first experiments conducted by Canti’s group on the role of photodynamic therapy in generating immunity against cancer. It highlights for the first time the effective role of PDT in the induction of anti-tumor T lymphocytes and shows that this effect is tumor-specific. It has also been reported how this adoptive immunity can improve the efficacy of chemotherapy. These studies have helped to open an important new field of scientific research on the role of PDT-generated immunity and to stimulate today’s important new pre-clinical approaches. Graphical abstract: (Figure presented.
Giampaolo Galvani. Agamennone. I canti. Eschilo
No full textRecensione di Galvani, G. (2021). Agamennone. I canti. Eschilo. Pisa: Fabrizio Serra, 280 pp. I canti del teatro greco 9
Time-gated fluorescence imaging for the diagnosis of tumors in a murine model.
No full textA system for time-gated fluorescence imaging was used to perform measurements on tumor-bearing mice treated with hematoporphyrin derivative (HpD). The aim of the study was to define the potential of this technique in the diagnosis of tumors by taking advantage of the long fluorescence lifetime of the exogenous dye with respect to the decay times of the natural fluorescence. After the administration of three different drug doses (5, 10 and 25 mg/kg body weight), fluorescence images were acquired at various uptake times (from 2 h to 10 d), to determine the best instrumental conditions and experimental procedure for the detection of tumors in the murine model considered. The optimal fluorescence contrast between the tumor area and the surrounding healthy tissue was found at 12 h after the administration of either 5 or 10 mg/kg HpD and was anticipated at 8 h for the highest drug dose. In this optimum condition, the tumor region could be identified even after the injection of 5 mg/kg HpD. A better fluorescence contrast was always obtained in 15 ns-delayed images with respect to synchronous ones
Time-gated fluorescence spectroscopy of porphyrin derivatives and aluminium phthalocyanine incorporated in vivo in a murine ascitic tumour model.
No full textThe effect of systemic administration on drug uptake at cellular level was evaluated using time-gated fluorescence spectroscopy performed on a murine ascitic tumour model. Mice bearing L1210 leukaemia were injected intraperitoneally or intravenously with 25 mg per kg body weight hematoporphyrin derivative (HpD), 12.5 mg per kg body weight photofrin II (PII), 25 or 5 mg per kg body weight disulphonated aluminium phthalocyanine (AlS2Pc). Every 2 h and for up to 22 or 30 h, mice were sacrificed, leukaemic cells extracted from the peritoneum, washed, and resuspended in buffer for fluorescence measurements. HpD and PII emission spectra were almost identical 12 h after intraperitoneal injection with main peaks at 630 nm and no appreciable changes afterwards. In the first 12 h, the PII fluorescence spectrum was constant, while in the case of HpD a shoulder at 615 nm was detectable. Similar fluorescence behaviour was observed after intravenous administration of porphyrin derivatives. These results seem to confirm that the tumour localizing fraction is the part actually retained by the cells. The AlS2Pc spectrum peaked at 685 nm and did not change in any of our experiments. AlS2Pc is incorporated more rapidly with respect to porphyrins, as was clearly observed in the case of intravenous administration, where the AlS2Pc fluorescence was readily detectable after 2 h, whereas the PII emission became apparent only after 4-6 h
Photodynamic effects of new photosensitizer agents in human colon adenocarcinoma cell lines.
No full text[Possible applications of living BCG and the BCG cell wall in immunotherapy]
No full textBCG, Bacillus Calmette-Guerin, has an immunostimulant capacity and antitumor activity against both experimental and human tumors. Its mechanism of action has not yet been well clarified; maybe it involves one or more immune cell populations: in fact BCG has been reported to loose its activity in immunosuppressed animals. A limiting factor for systemic use of living BCG is its high toxicity: therefore BCG-derivatives have been introduced in both the experimental and the clinical fields. For experimental use one of the most interesting of these products is BCG-cell wall: when used in laboratory animals it demonstrated an efficient dose-dependent antitumor activity and lack of toxicity. On the contrary living BCG was notably toxic and ineffective when used in high doses. An interesting approach in antineoplastic therapy is the use of BCG with tumor cells as a vaccine against micrometastases remaining after surgery, chemotherapy or radiotherapy. A vaccine containing BCG-cell wall and tumor cells (either living or x-irradiated) gave very encouraging experimental results for a possible clinical use in the treatment of tumor metastases
- …
