Cytotoxicity of paclitaxel in combination with cisplatin and a new Pt-mercaptopyridine complex.

In vitro synergy has been reported for exposure to paclitaxel prior to cis-platin (cis-DDP), whereas the reverse sequence resulted in antagonism. There is no clear evidence for an intracellular origin of the schedule-dependent interaction, but several hypotheses have been proposed, such as effects at the level of DNA crosslinks, or binding to tubulin sites. The purpose of this study was to evaluate the cytotoxicity of these two drugs as single agents, in combination and in sequence, against a human colon adenocarcinoma cell line (LoVo).

A comparison of the modulation of antiblastics cytotoxicity by verapamil and dipyridamole in a human colon carcinoma cell line.

This study was designed to compare the activity of two MDR modulators, verapamil and dipyridamole, on the in vitro growth of a human colon carcinoma cell line. The aims were: a) to investigate the different sensitivity of the parental cell line (LoVo S) and the doxorubicin-resistant one (LoVo R) towards the treatment with several antiblastics and their associations with verapamil or dipyridamole; b) to evaluate if the combined use of these drugs with verapamil or dipyridamole increases their cytotoxicity; c) to understand whether the mechanism of action of each modulator is the same. Idarubicin and vinblastine were the most active drugs on both cell lines.

In vitro effect of Pt and Pd mercaptopyridine complexes.

In previous research we studied the cytotoxic effect of new Pt mercaptopyridine (MP) complexes on several tumoral cell lines (F10, Föhn, LoVo and HeLa) as well as on the fibroblast cell line (3T3). The more interesting Pt compounds are compared here to Pd mercaptopyridine analogs, in order to evaluate the metals influence on activity. Earlier, the complexes C/2 = [Pt(MP)3Cl]Cl; C/5 = [Pt(MP)3Br]Br; C/8 = [Pd(MP)3Cl]Cl and C/11 = [Pd(MP)3Br]Br and cis-DDP as reference were tested on 3T3 and LoVo cells, by Sauter's multiwells technique and neutral red uptake.

Use of decision analysis in a family practice residency for a patient with an abdominal aortic aneurysm.

Background: A patient at the Tatem-Brown Family Practice Center with many medical problems asked for advice about elective surgical resection of a large abdominal aortic aneurysm.

Methods: The best course of action was not obvious, so a decision tree was constructed using data from the medical literature and the patient's rating of several quality of life issues.

Results: Elective surgery was the optimal choice for this patient, but the decision was sensitive to values chosen for two variables in the decision model.

Effect of dipyridamole, 5'-(N-ethyl)-carboxamidoadenosine and 1,3-dipropyl-8-(2-amino-4-chlorophenyl)-xanthine on LOVO cell growth and morphology.

The effects of stable compounds acting on adenosine receptors, 5'-(N-ethyl)-carboxamidoadenosine (NECA: A2 and A1 adenosine receptor agonist) and 1,3-dipropyl-8-(2-amino-4-chlorophenyl)-xanthine (PACPX: selective A1 adenosine receptor antagonist) were evaluated in vitro on doxorubicin-resistant LoVo (LoVo-R) and doxorubicin-sensitive LoVo (LoVo-S) human metastatic cell lines by using the neutral red test for cell growth. The effect of dipyridamole, an adenosine uptake inhibitor, was also evaluated. The drugs had an inhibitory effect on LoVo cell growth.

The effect of cis-DDP and Pt mercaptopyridine complexes on cell lines in vitro.

The effect of Platinum (II) complexes with mercaptopyridines on cell lines (fibroblasts 3T3 and the tumour ones F10, Föhn, Lovo) were studied. Synthesis and characterization of the compounds are reported together with the preliminary in vitro tests. Data obtained on cytopathogenic effect (CPE), cell growth and colony forming ability demonstrated that all the platinum mercaptopyridines tested are more active than cisplatin in the same conditions.

Increased spontaneous cell detachment of F10 cells induced in vitro by some calcium-channel blockers.

We investigated the action of some Ca(++)-channel blockers such as flunarizine, nifedipine and verapamil on F10 cells in vitro. Cell adhesion to the growth substratum, evaluated by the technique of spontaneous detachment in culture medium, is reduced in Ca(++)-channel blocker treated cells by comparison with controls. In our opinion such an event could also explain the inhibitory effect on cell growth and colony forming ability.

The effect of Dilazep on F10 cells in vitro.

Experiments on F10 cell growth, colony ability, cell adhesion and ultramorphology at SEM have been performed. The effect of Dilazep (DIL) has been compared with that of well known modulating agents such as Flunarizine (FLU) and Verapamil (VER) on cells cultured in high Ca++ medium (HCM) and in low calcium medium (LCM). While in HCM there is no difference among the three drugs, FLU and VER had a stronger effect on cell growth inhibition in LCM.

Arginine 2-mercaptoethane sulfonate and sodium 2-mercaptoethane sulfonate: a comparative study of their effects upon tumour cells.

The action of arginine 2-mercaptoethane sulfonate in comparison with sodium 2-mercaptoethane sulfonate on cell growth and cell adhesion of a metastatic sub-line of murine melanoma (F10/B16) was investigated. The capability of the two compounds to interfere with the cytotoxicity of 4-hydroperoxycyclophosphamide and of cis-dichlorodiammineplatinum(II) in F10 cells was studied. The in vivo studies included the determination of acute and sub-acute toxicity of the two salts on mice.

Effects of 6,6'-dithiodinicotinic acid (CPDS) and its metabolite 6-mercaptonicotinic acid (6-MNA) on murine and hamster fibroblasts (3T3 and BHK) and murine metastatic melanoma cells (F10).

We investigated the action of 6,6'-dithiodinicotinic acid (CPDS) and its metabolite 6-mercaptonicotinic acid (6-MNA) in vitro on murine (3T3) and baby hamster kidney (BHK) fibroblasts and an in vivo highly metastatic subline of murine B16 melanoma (F10). CPDS determined an inhibition of cell growth and a decrease in cell adhesion, while 6-MNA had no effect. When combined with data of the mitotic index and endogenous purine ribonucleotides (on which the drugs seem to have no effect), these observations are conceivable with the hypothesis that the primary target of CPDS is cell membrane.

Effect of peptichemio and of peptichemio plus hydrocortisone on growth and alkaline phosphatase activity in HeLa cells in vitro.

The actions of Hydrocortisone, Peptichemio and of Peptichmio + Hydrocortisone mixture in HeLa cells have been experimented. The results show an increase of cell number in the controls and a lower, but not statistically different growth, in the Hydrocortisone-treated cultures. In the cultures treated with peptichemio the growth is hardly evident, in the ones treated with the Hydrocortisone + Peptichemio mixture, the cell number is decreasing with time.

Biochemical and cytochemical effects of cytosine arabinoside (ARA C) and hydrocortisone on HeLa cells.

The biochemical and cytochemical effects of cytosine arabinoside (Ara C) and of hydrocortisone on HeLa cell in vitro have been studied. In cultures treated with Ara C, a relationship exists between the cytocidal effects of the drug and an increase in alkaline phosphatase. Although hydrocortisone had no influence on the proliferative rhythm, it induced an increase in alkaline phosphatase.

Effect of some antiblastic drugs on HeLa cells.

The antiblastic effects of the antimetabolites MTS, Ara-C, Bleomycin of the alkylating Thiotepa, of Peptichemio (alkylating and antimetabolic) and of Peptichemio-Bleomycin combination, were compared after 24 and 48 hr of treatment on HeLa cells. Ara-C, which inhibits typical mitoses, Peptichemio and MTX, which inhibit atypical mitoses, Thiotepa, which induces the highest percentage of pyknotic nuclei, showed a considerable effect on the nucleus. Peptichemio, and the combination Peptichemio-Bleomycin showed a significant effect on the cytoplasm (induction of vacuoles).