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F Pepi

Publications and source records attributed to F Pepi.

At least 19 recordsLinked to original sources
PubMed2000

Ionization of ozone/chlorofluorocarbon mixtures in atmospheric gases: formation and remarkable dissociation of

The reactions occurring upon ionization of mixtures containing ozone and CHX2Y (X = H, Cl, F; Y = Cl, F) halocarbons diluted in atmospheric gases (O2, N2) have been investigated in detail by mass spectrometric and theoretical methods. In all systems investigated the reactivity pattern is characterized by the preliminary formation of [CHXY x O3+] adducts which undergo unimolecular dissociation into HXYO2+ and CO. This remarkable dissociation which requires extensive molecular reorganization is exceptional for hydrogenated halocarbons. The work represents the first systematic study of the ionic chemistry in systems containing both ozone and halocarbons diluted in atmospheric gases.

Journal Article↗
PubMed2000

Gas-phase reactions of nitronium ions with acetylene and ethylene: an experimental and theoretical study

A comparative study of the gas-phase reactions of NO2+ with acetylene and ethylene was performed by using FT-ICR, MIKE, CAD, and NfR/ CA mass spectrometric techniques, in conjunction with ab initio calculations at the MP2/6-31+G* level of theory. Both reactions proceed according to the same mechanism, that is, 1,3-dipolar cycloaddition, but yield products of different stability. The C2H2NO2+ adduct from acetylene has an aromatic character and hence is highly stabilized with respect to the C2H4NO2+ adduct from ethylene. Both cycloadducts tend to isomerize into O-nitroso derivatives, that is, nitrosated ketene and nitrosated acetaldehyde, which represent the thermodynamically most stable products from the addition of NO2+ to acetylene and ethylene, respectively. As prototypal examples of the reactivity of free nitronium ions with most simple pi systems, the reactions investigated are useful starting points to model the mechanism of aromatic nitration.

Journal Article↗
PubMed1999

Experimental detection of hydrogen trioxide

Hydrogen trioxide (HO3) has long been postulated as a key intermediate in important atmospheric processes but has proved difficult to detect. The molecule was unequivocally detected in experiments based on neutralization-reionization and neutralization-reionization/collisionally activated dissociation mass spectrometry, using protonated ozone (HO3+) as the charged precursor. Hydrogen trioxide is a relatively stable species and has a H-O-O-O connectivity and a lifetime exceeding 10(-6) seconds at ambient temperature.

Journal Article↗
PubMed1999

Intimal-type primary sarcoma of the aorta. Report of a case with evidence of rhabdomyosarcomatous differentiation.

We report an intimal sarcoma presenting as an aortic aneurysm. A 68-year-old man suffered from chest pain and speech disturbance. Computed tomography showed a sacciform aneurysm of the aorta, which was resected, revealing a polypoid tumour measuring 1.5x2x2.5 cm projecting into the lumen. This proved to be a poorly differentiated high-grade sarcoma having morphological, immunophenotypic and ultrastructural features consistent with rhabdomyosarcomatous differentiation. Primary sarcomas of the aorta are extremely rare. Many cases have been diagnosed as "intimal" on the basis of their site of origin, and they are not easy to classify from their histological pattern. Electron microscopy and the use of a more comprehensive panel of immunohistochemical markers should be applied in the histological classification of"intimal" sarcoma.

Aged↗
PubMed1999

Ionization of Ozone/Chlorofluorocarbon Mixtures in Atmospheric Gases: Formation and Dissociation of

Complexes that undergo extensive molecular reorganization upon unimolecular metastable dissociation are obtained after ionization of atmospheric gases containing ozone and chlorofluorocarbons [Eq. (1)]. These unusual processes, which require fission of all bonds initially present in the CHX(2) unit (X=Cl, F) and combination of C with one of the O atoms of ozone, were demonstrated and their mechanism rationalized by the joint application of mass spectrometric and theoretical methods.

Journal Article↗
PubMed1998

Carboplatin and vinorelbine in the treatment of advanced non-small-cell lung cancer: a multicenter phase II study.

The aim of this study was to identify a chemotherapy combination that would be active and well tolerated for palliative treatment of advanced non-small-cell lung cancer (NSCLC). From February 1992 to December 1994, a total of 77 patients affected by stage-IIIB and stage-IV NSCLC were treated with carboplatin 350 mg/m2 on day 1 and vinorelbine 25 mg/m2 on days 1 and 8 of each cycle, with cycles repeated every 28 days. All patients were evaluable for response and toxicity. A total of 24 patients showed a partial response (31% response rate; 95% CI = 21-41%). The median duration of overall survival was 41 weeks (95% CI = 31-51), and the median time to disease progression was 34 weeks (95% CI = 25-43). The treatment was well tolerated: no grade-4 toxicity was observed. The carboplatin-vinorelbine combination deserves to considered as a valid alternative to regimens that include cisplatin for palliative treatment of advanced NSCLC.

Adult↗
PubMed1998

[Restaging brain computerized tomography after treatment of non-operable lung neoplasms].

PURPOSE: To assess the role of CT brain scans as a routine restaging procedure after primary, aggressive, drug or radiation therapy of unresectable lung cancer. If early, asymptomatic brain metastases are detected and treated, survival could be improved relative to the patients showing brain involvement in a later CT scan performed during the follow-up, at the onset of neurological symptoms. MATERIAL AND METHODS: One hundred patients affected with lung cancer, unresectable on account of histology (small-cell carcinoma) or advanced stage (III, IV) were submitted to chemo- and/or radiotherapy, after a clinical staging including brain CT, which was negative in all patients. Brain CT was also repeated at the end of therapy (restaging), in the absence of any neurological symptom. Further scans were obtained during the subsequent follow-up only when clinical symptoms occurred, suggesting metastases to the brain. Survival values were analyzed in the patients whose brain involvement was detected during restaging, vs those showing symptomatic brain metastases during the follow-up. RESULTS: Only 4 patients had asymptomatic metastases, diagnosed with the restaging brain CT scan. Their survival rate was significantly lower than that of the 20 patients whose brain involvement was shown by a follow-up CT scan, performed after the onset of neurological symptoms. However, death was rarely a consequence of brain metastases: primary or other metastatic sites were involved in the terminal events, in the greatest majority of these cases. DISCUSSION AND CONCLUSIONS: The sudden, asymptomatic brain involvement, detected at restaging CT scan after primary therapy for unresectable lung cancer, does not correlate with a better prognosis than symptomatic metastases, diagnosed later with a follow-up CT obtained performed for clinical suspicion. Therefore the use of restaging CT scan is not warranted, as a routine procedure, except for the clinical trials intended to define optimal treatment schedules.

Adult↗
PubMed1997

Gas-phase NO+ affinities.

A scale of relative gas-phase NO+ binding energies (BEs) has been constructed by evaluation of NO+-transfer equilibria LINO+ + L2 <==> L2NO+ + L1 by Fourier-transform ion cyclotron resonance mass spectrometry and by application of the kinetic method, based on the metastable fragmentation of L1(NO+)L2 nitryl-ion bound dimers. The relative scale, anchored to the NO+ affinity of water, for 52 ligands, including alkyl halides, alkyl nitrates, alcohols, nitroalkanes, nitriles, aldehydes, ketones, and aromatic and heterocyclic compounds, led to an absolute NO+ affinity scale. The results are compared with those of an earlier study, and the apparent discrepancies are traced to a different choice of the absolute BE value used as the reference standard. The NO+ BEs fit a satisfactorily linear correlation when plotted versus the corresponding proton affinities (PAs). The NO+ BEs, while much lower than the PAs, are nevertheless higher than the corresponding BEs of the strictly related NO2+ cation, a result consistent with the experimental and theoretical results currently available on the structure and the stability of NO+ and NO2+ complexes. The NO+ BE vs. PA correlation allows one to estimate within 1-2 kcal x mol(-1) the NO+ BE of the molecules included in the comprehensive PA compilations currently available. For example, the correlation gives the following NO+ affinities of the DNA bases, in kcal x mol(-1) (1 kcal = 4.18 kJ): adenine, 40.3; cytosine, 40.4; guanine, 40.1; and thymine, 34.9. The experimental NO+ BE of thymine, the only one accessible to direct measurement, amounts to 35.6 +/- 2 kcal x mol(-1), which underlines the predictive value of the correlation. This study reports the second successful extension of the kinetic method to the evaluation of the absolute BEs of polyatomic cations, following our recent application to the strictly related NO2+ ion.

Binding Sites↗
PubMed1995

Gas-phase nitronium ion affinities.

Evaluation of nitronium ion-transfer equilibria, L1NO2+ + L2 = L2NO2+ + L1 (where L1 and L2 are ligands 1 and 2, respectively) by Fourier-transform ion cyclotron resonance mass spectrometry and application of the kinetic method, based on the metastable fragmentation of L1(NO2+)L2 nitronium ion-bound dimers led to a scale of relative gas-phase nitronium ion affinities. This scale, calibrated to a recent literature value for the NO2+ affinity of water, led for 18 ligands, including methanol, ammonia, representative ketones, nitriles, and nitroalkanes, to absolute NO2+ affinities, that fit a reasonably linear general correlation when plotted vs. the corresponding proton affinities (PAs). The slope of the plot depends to a certain extent on the specific nature of the ligands and, hence, the correlations between the NO2+ affinities, and the PAs of a given class of compounds display a better linearity than the general correlation and may afford a useful tool for predicting the NO2+ affinity of a molecule based on its PA. The NO2+ binding energies are considerably lower than the corresponding PAs and well below the binding energies of related polyatomic cations, such as NO+, a trend consistent with the available theoretical results on the structure and the stability of simple NO2+ complexes. The present study reports an example of extension of the kinetic method to dimers, such as L1(NO2+)L2, bound by polyatomic ions, which may considerably widen its scope. Finally, measurement of the NO2+ affinity of ammonia allowed evaluation of the otherwise inaccessible PA of the amino group of nitramide and, hence, direct experimental verification of previous theoretical estimates.

Journal Article↗
PubMed1994

[Radiotherapy of limited pulmonary microcytoma in current clinical practice].

The use of thoracic irradiation in the treatment of "limited disease" small-cell lung cancer yields better local control and survival rates than chemotherapy alone, according to meta-analysis studies of randomized clinical trials. Outside experimental studies, however, the role radiotherapy can currently play in the management of this type of cancer is difficult to assess because treatment modalities and patient selection criteria differ greatly. We report on the treatment outcome obtained in the Radiotherapy Department of the University of Siena in a series of 86 patients with small-cell lung cancer consecutively referred, January 1986 to January 1992; after a thorough staging, 46 of them were diagnosed as having a "limited disease". A "sequential" chemo-radiotherapy combination was used: irradiation was delivered after the completion of the initial drug treatment. Twenty-four patients (52.5%) achieved a complete and 22 (47.5%) a partial objective remission after chemotherapy, with acceptable early toxicity rates and severity. Twenty-eight of them received irradiation according to the following selection criteria: objective remission after chemotherapy (19 of 24 complete responders, excluding those with initial pleural effusion or worsening medical status during chemotherapy) and initial large tumor bulk (9 of 22 patients in partial remission). The overall treatment outcome rate (median survival: 18 months, 2-year survival: 28%) is in agreement with that of similar previous studies; toxicity rates are also similar (2% of treatment-related deaths). Survival analysis, according to "performance status" score, chemotherapy schedule and the achievement of complete remission with the initial drug management, exhibited significant differences only relative to the latter parameter. Many recent clinical trials suggest that combined chemo-radiotherapy could improve these results: toxicity is however reported as heavy, with this approach. Some guidelines are here considered, which could make this combination reliable also for current clinical use.

Aged↗
PubMed1993

Breast-conserving treatment of early breast cancer. Results in a common clinical trial.

Results of large prospective trials, often based on selected series and optimal treatment techniques, indicate that breast conserving therapy is appropriate for most patients with early breast cancer. Questions remain regarding the therapeutic outcome in common practice. We report on a series of 206 consecutive, unselected patients treated with current radiotherapy procedures. The Kaplan-Meier evaluation showed 5- and 8-year survival rates (93%, 91%), distant disease-free survival rates (87%, 85%) and local relapse-free survival rates (90%, 88%) that were comparable to those of the conservative arms in reported randomised trials and to the data from retrospective studies reported by authoritative institutions. However, subanalysis according to prognostic factors such as menopausal status, age and axillary nodal status was of limited value, due to the small number of cases.

Adult↗
PubMed1992

Unfavorable experience with hypofractionated radiotherapy in unresectable lung cancer.

The use of a reduced number of large-sized fractions in radiotherapy (hypofractionation) is usually associated with poor therapeutic results and severe adverse effects, in accord with radiobiologic concepts. However by some authors unresectable lung cancer patients have been treated with hypofractionated radiotherapy with the main aim of "convenience". Result and damage rates are reported to be comparable to those of conventional treatment. In our experience, based on palliative irradiation of 86 advanced-stage, nonmicrocytoma patients, objective remission rates, subjective and performance status improvement, and survival overall were as poor as could be expected in this kind of presentation, with no striking impact of this treatment modality. Severe adverse effects were shown by a large proportion of cases involving skin and soft tissues of the chest wall (40%) and lungs (55.5%). The incidence of severe damage was in agreement with BED (biologic effective dose) values, differently from other experiences of radiotherapeutic management of advanced lung cancer with large fractions.

Adult↗
PubMed1992

Carboplatin and vindesine in advanced non-small cell lung cancer. A feasibility study.

Twenty-eight patients affected by advanced non-small cell lung cancer (NSCLC) were enrolled in a feasibility study evaluating toxicity and activity of carboplatin-vindesine combination chemotherapy, according to two different schedules. Fourteen patients were treated with carboplatin 350 mg/m2 monthly and vindesine 3 mg/m2 weekly for 5 doses, then every other week (schedule 1). The activity observed was promising with 3 partial remissions, but the toxicity was substantial, preventing full dose administration in 11 out of 14 patients. The subsequent 14 patients were treated with carboplatin 350 mg/m2 monthly and vindesine 3 mg/m2 on days 1 and 8 of each cycle. Activity was maintained with 4 partial remissions and toxicity was quite tolerable, allowing all patients to receive the planned treatment. The combination of carboplatin 350 mg/m2 on day 1 and vindesine 3 mg/m2 on days 1 and 8 seems active and well tolerated in advanced NSCLC patients and deserves further evaluation in a larger phase II study.

Adult↗
PubMed1989

Chemo-radiotherapeutic management of advanced head and neck cancer.

Stage III and IV head and neck cancer patients usually achieve poor therapeutic results after radiotherapy. The search for more effective treatment modalities is justified, provided that tolerance is not lower than that of the usual radiation therapy schedules. Chemotherapy has been shown to be effective, and cis-platinum and bleomycin based treatments are reported to result in objective remissions in a substantial proportion of cases. There is also experimental evidence of a radiosensitizing activity of cis-platinum. Thirty-five locally advanced head and neck cancer patients were given combined chemo-radiotherapeutic treatment consisting of a cis-platinum and bleomycin induction followed by a standard radiotherapy course integrated with weekly administrations of cis-platinum. Before radiotherapy, an overall 48.5% objective remission rate was achieved, that rose to 85.8% after completion of the entire treatment, with a 31.5% complete response rate. Incidence and severity of radiation mucositis seem not to be increased, and systemic toxicity is very low, with the adopted drug administration schedule. Overall results do not show any obvious superiority over those of radiotherapy alone.

Aged↗
PubMed1988

Weekly epirubicin in advanced breast cancer.

Twenty-nine advanced breast cancer patients, considered unable to tolerate conventional cytotoxic chemotherapy, were treated with a weekly schedule of epirubicin (15 mg/m2 i.v.). All patients were fully evaluable. A remission of 34.5% was observed (2 CR; 8 PR), with a median duration of response of 9 months (range, 3-24 months). Side effects were mild, and on the whole the toxicity was negligible. This regimen showed a favorable therapeutic ratio in our series and seems active and well tolerated even in elderly and/or poor performance status patients.

Adult↗