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F Paoletti

Publications and source records attributed to F Paoletti.

85 records · Page 5Linked to original sources
PubMed1980

Studies on the kinetics of initial cycle progression in vitro of ascites tumour cells subsequent to isolation from ascites fluid.

A method is described for determining the duration of cell cycle phases traversed by cells responding to release from proliferation restraint. Experiments have been performed with arrested Yoshida ascites hepatoma cells allowed to re-enter the growing stage after transfer of cells from the late stage of ascites into an in vitro incubation system. Experimentally, this method requires information on the rate of incorporation of labelled thymidine and on the rate of increase in cell number. The rate of [14C]thymidine incorporation in vitro was shown to be directly proportional to the number of cells synthesizing DNA. This was shown by correlating data from measurements of the rate of thymidine incorporation with those from measurements of the labelling index of the cell population. Theoretically, the method is based on analysis of the region limited by two integral curves, one corresponding to the kinetics of cell entry into and the other to the kinetics of exit from the S-phase. From data on the actual rate of increase in the total number of cells and data on the S-phase duration it is possible to obtain information on the cytokinetics of growth resumption by the ascites cell population.

Animals↗
PubMed1974

Protein metabolism in tumor cells at various stages of growth in vivo.

Protein metabolism of Yoshida ascites hepatoma cells was studied in the early phase of logarithmic proliferation and in the following stage in which cell mass remains constant (resting phase). The rate of protein synthesis was measured by a short-time incorporation of [(8)H]lysine, while degradation was concurrently assessed by following the decrease of specific activity of [(14)C]lysine-labeled proteins. Most of the labeled amino acid injected intraperitoneally into the animal was immediately available for the tumor cells, with only a minor loss towards the extra-ascitic compartment. It was thus possible to calculate the dilution of the isotope in the ascitic pool of the lysine, which increased concurrently with the ascitic plasma volume. Amino acid transport capacity did not change in the log vs. the resting cells. This fact permitted the correction of the specific activity of the proteins synthesized by tumors in the two phases, taking into account the dilution effect. Protein synthesis was found to proceed at a constant rate throughout each of the two phases, although it was 30% lower during the resting as compared to the log phase. When cell mass attained the steady-state, protein degradation occurred at such a level as to balance the synthesis. Throughout the resting phase the amount of lysine taken up by the cells and renewed from the blood remained unchanged. Protein turnover, as studied in subcellular fractions, exhibited a similar rate in nuclei and microsomes, where it proceeded at a higher level than in mitochondria. On the whole, the results encourage the use of the Yoshida ascites hepatoma as a suitable model for studying protein turnover in relation to cell growth in vivo.

Animals↗
PubMedDate not supplied

Fate of antimony in municipal solid waste incineration.

The average antimony concentration in municipal solid waste is estimated to be about 10-60 ppm. Thermodynamical models predict a volatile behavior for antimony compounds, yet literature mass balances show that about 50% of the antimony input remains in the grate ashes. This fact can be explained by the formation of thermally stable antimonates in the fuel bed due to interactions with alkali or earth-alkali metals. Thermogravimetric experiments revealed an increased thermal stability for antimony oxide in presence of oxygen and calcium oxide. Spiking experiments on the test incinerator TAMARA showed that chlorination processes have a strong effect on antimony volatilization whereas high fuel-bed temperatures and addition of antimony oxide only have a moderate effect. In the grate ashes, antimony shows a pH-depending leaching property, which is typical for anionic species. This fact supports the thesis that antimony is present in the grate ashes in an anionic speciation.

Journal Article↗
PubMedDate not supplied

[Propofol versus thiopentone. A hemodynamic study].

The authors, after a brief introduction concerning the importance of the use of NCCOM3 (Non invasive Continuous Cardiac Output Monitor) for the non invasive assessment of the haemodynamic parameters (Cardiac Output, Heart Rate, Ventricular Ejection Time, Stroke Volume), compare the haemodynamic variations induced by two types of intravenous anesthesia in 40 patients, selected at random, who underwent anesthesia for minor gynaecological procedures in the day hospital. The results obtained show that the haemodynamic variations induced by thiopentone and propofol are almost analogues until the end of surgery, while a difference, even though statistically non significant, was observed at the moment of reawakening. The authors would like to underline the synergism of two drugs and fentanyl as regards to the depressive effects on blood circulation.

Adult↗