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Biomedical subjects

M Pazzagli

Publications and source records attributed to M Pazzagli.

116 records · Page 7Linked to original sources
PubMedDate not supplied

Effects of gemcitabine in normal and transformed human lung cell cultures: cytotoxicity and increase in radiation sensitivity.

AIMS AND BACKGROUND: Several anticancer drugs increase cell sensitivity to irradiation. Gemcitabine (2', 2' difluorodeoxycytidine) decreases the cellular dNTP pools and thus significantly increases the sensitivity to the DNA damaging effects of low-dose radiation. In this study we have investigated whether gemcitabine may play a role as radiosensitizer also in lung adenocarcinoma treatment. METHODS & STUDY DESIGN: We studied this nucleoside analogue in normal and transformed human cell lines (fetal lung and lung adenocarcinoma). After drug treatment, cell lines were irradiated with different doses. Cell damage following drug treatment and/or irradiation was assessed by measuring intracellular ATP level and by the colony forming assay. RESULTS: The two cell lines significantly differed in their sensitivity to the toxic effects of the drug; the normal cell line was much more resistant than its transformed counterpart. This difference was observed in both assays, although it was more evident in the colony forming assay. A low radiation dose (50-100 cGy) did not cause any significant damage to transformed cells; normal cells were more resistant and doses up to 500 cGy caused little damage. However, when transformed cells were pretreated for three hours with gemcitabine, even a nontoxic concentration of the drug (1-10 nM) caused a marked sensitization of the cells to irradiation (50-100 cGy). The radiosensitizing effect of gemcitabine could be observed also in normal cells, although these cells were more resistant to the damaging effects of both anticancer treatments. CONCLUSIONS: This study demonstrates that gemcitabine, a chemotherapeutic agent already used in the clinic, could be proposed as a radiosensitizer for radiation therapy of lung adenocarcinoma, having a clearly potentiating effect on lowdose radiation.

Adenocarcinoma↗
PubMedDate not supplied

Statistical diagnostics emerging from external quality control of real-time PCR.

Besides the application of conventional qualitative PCR as a valuable tool to enrich or identify specific sequences of nucleic acids, a new revolutionary technique for quantitative PCR determination has been introduced recently. It is based on real-time detection of PCR products revealed as a homogeneous accumulating signal generated by specific dyes. However, as far as we know, the influence of the variability of this technique on the reliability of the quantitative assay has not been thoroughly investigated. A national program of external quality assurance (EQA) for real-time PCR determination involving 42 Italian laboratories has been developed to assess the analytical performance of real-time PCR procedures. Participants were asked to perform a conventional experiment based on the use of an external reference curve (standard curve) for real-time detection of three cDNA samples with different concentrations of a specific target. In this paper the main analytical features of the standard curve have been investigated in an attempt to produce statistical diagnostics emerging from external quality control. Specific control charts were drawn to help biochemists take technical decisions aimed at improving the performance of their laboratories. Overall, our results indicated a subset of seven laboratories whose performance appeared to be markedly outside the limits for at least one of the standard curve features investigated. Our findings suggest the usefulness of the approach presented here for monitoring the heterogeneity of results produced by different laboratories and for selecting those laboratories that need technical advice on their performance.

Clinical Laboratory Techniques↗
PubMedDate not supplied

Biological parameters for the choice of antiangiogenic therapy and efficacy monitoring.

Angiogenesis is a tightly controlled process which depends on the balance between stimulating and inhibiting factors. When this balance is disrupted, angiogenesis acquires a pathological meaning. The list of molecules able to induce angiogenesis is heterogeneous with respect to their chemical characteristics and biological properties. Quantitative measurement of tumor angiogenesis is necessary for the choice of therapeutic strategies and as an endpoint for antiangiogenic therapy. We are developing a quantitative RT-PCR with measures the expression of specific factors in real time. With the use of this rapid technique, measurement of the expression of the angiogenic factors and inhibitors is also possible in specimens as small as biopsies.

Angiogenesis Inhibitors↗
PubMedDate not supplied

Quantitative RT-PCR assay for VEGF mRNA in human tumors of the kidney.

Angiogenesis is the formation of new capillaries from pre-existing vessels, and recent evidence has demonstrated that tumor growth is controlled mainly by angiogenesis. Vascular endothelial growth factor (VEGF) is an endothelium-specific growth factor which is strongly angiogenic in vitro and in vivo. We have developed a quantitative RT-PCR assay for the measurement of VEGF mRNA expression using a real-time procedure based on the use of fluorogenic probes and the ABI PRISM 7700 Sequence Detector System. The assay performance of this method in terms of practicability and reliability is reported with results that seem promising for its widespread use in the clinical laboratory. The method has been applied to the measurement of mRNA of VEGF in human renal cell carcinomas (RCC). Preliminary results show a significantly higher VEGF mRNA expression (ratio values between 181 and 2222) in tumor specimens compared to non-adjacent, non-tumoral tissue of the same subjects.

Aged↗
PubMedDate not supplied

[An angiogenesis study of Dukes' B colonic tumors].

PURPOSE: To evaluate the angiogenesis in Dukes' B colon cancer. PATIENTS AND METHODS: In 60 patients (age, 39-75 years), the microvessel density and the relationship between the angiogenesis and other histologic features were retrospectively evaluated. In an ongoing prospective study, 25 patients have been enrolled to determine the possible therapeutic implications of VEGF quantitative analysis. RESULTS: The retrospective portion of this study confirms the prognostic value of the angiogenesis in terms of recurrences and survival. At present, no conclusions can be drawn from the prospective portion of the study.

Aged↗