Biomedical subjects

P Conte

Publications and source records attributed to P Conte.

At least 37 records · Page 2Linked to original sources

PubMed1999

Suramin in combination with weekly epirubicin for patients with advanced hormone-refractory prostate carcinoma.

BACKGROUND: Suramin and epirubicin are both active agents in the treatment of patients with hormone-refractory advanced prostate carcinoma, with demonstrated antitumor synergism in vitro on human prostate carcinoma cells and different dose-limiting toxicities. The authors conducted this Phase II study to determine the feasibility, toxicity, and antitumor activity of suramin in combination with epirubicin. METHODS: Only patients with hormone-independent advanced prostate carcinoma who had progressive disease after the last therapeutic maneuver they had undergone, including antiandrogen withdrawal, entered the study. Suramin was administered initially as a 6-day continuous infusion for 10 consecutive weeks and then for 6 days every 28 days for a maximum of 6 months. Doses were determined by a computer-assisted dosing system that used Bayesian pharmacokinetics to maintain suramin plasma concentrations of 200-250 microg/mL. Cortisone acetate 25 mg, administered at 8 a.m. and 8 p.m. daily, was begun 4 weeks after the initiation of suramin therapy. Epirubicin 25 mg/m2 was given as a weekly intravenous bolus beginning on Day 1 and was continued for a maximum of 6 months. RESULTS: Twenty-six patients entered the study. Toxicities mainly included World Health Organization Grade 1-2 nausea, fatigue, anorexia, neutropenia, peripheral neuropathy, creatinine elevation, proteinuria, and prolonged prothrombin time, whereas Grade 3 toxicities were uncommon. Among 11 patients with measurable disease, 3 (27%) demonstrated an objective response. Among 24 patients evaluated for prostate specific antigen (PSA) response, 8 (33%; 95% confidence interval 16-55%) had a > or =50% decrease in PSA levels, which lasted a median of 32 (range, 8-52) weeks. Median progression free and overall survival were both 8 months. CONCLUSIONS: The combination of suramin and epirubicin used in the current study is feasible, is associated with moderate toxicities, and has antitumor activity in advanced hormone-refractory prostate carcinoma. However, the results obtained with this combination do not represent major improvements in the treatment of patients with this disease, compared with suramin or epirubicin alone or other available treatments.

Aged↗

PubMed1999

Protracted continuous infusion of 5-fluorouracil and low-dose leucovorin in patients with metastatic colorectal cancer resistant to 5-fluorouracil bolus-based chemotherapy: a phase II study.

Continuous-infusion (c.i.) 5-fluorouracil (5-FU) can overcome resistance to bolus 5-FU, and leucovorin (LV) enhances the cytotoxic effects of 5-FU, mainly when the duration of exposure to the latter is prolonged. The main objective of this study was therefore to determine the activity of a prolonged infusion schedule of 5-FU + LV in patients with metastatic colorectal cancer resistant to a 5-FU bolus-based chemotherapy. Only patients with metastatic measurable disease in progression during or within 2 months of the end of a 5-FU bolus +/- LV-based chemotherapy were eligible for the study. 5-FU and l-LV were given as a 14-day c.i. every 28 days, the 5-FU dose being 200 mg/m2 per day and the l-LV dose being 5 mg/m2 per day. A total of 59 patients entered the study, of which 48 were resistant to 5-FU + LV and 11, to 5-FU + levamisole. Treatment was well tolerated, and WHO grade 3-4 toxicities were uncommon (11% of patients developed stomatitis and 7%, diarrhea). According to an intent-to-treat analysis, 10 of 59 patients obtained an objective response (1 complete response, 9 partial responses), for an objective response rate of 16% (95% confidence interval 8-25%). The median progression-free survival and overall survival were 4 and 9 months, respectively. The protracted 5-FU + LV c.i. schedule used in the present study is a well-tolerated and moderately active regimen in metastatic colorectal cancer patients resistant to 5-FU bolus +/- LV. Only randomized studies can determine whether this palliative treatment has advantages in comparison with other second-line therapies such as 5-FU c.i. without LV, irinotecan, or oxaliplatin.

Adult↗

PubMed1999

High Pressure Size Exclusion Chromatography (HPSEC) of humic substances: molecular sizes, analytical parameters, and column performance

High Pressure Size Exclusion chromatography (HPSEC) is increasingly used to evaluate molecular sizes of humic substances from different sources. Asymmetry factors (As), number of theoretical plates (N), coefficient of distribution (k(d)), and column resolution (Rs) were determined for two different HPSEC columns (TSK G3000SW and Biosep S2000) and polysaccharides of known molecular weights were used as standards. Calibration curves were equivalent for both columns whereas analytical parameters revealed that the TSK column was only slightly more efficient in separating polysaccharide standards. Mw and Mn values for humic substances differed according to the molecular weight range of each column but relative standard deviation never exceeded 5% for both columns. Variations between columns were attributed to intrinsic humic properties such as the stability of conformational structures. These results suggested that humic substances in solutions are loosely-bound association of small molecules that may be consistently dispersed by diffusion through size-exclusion pores. HPSEC is confirmed to represent a highly precise method to evaluate the relative molecular-size distribution of dissolved humic substances.

Journal Article↗

PubMed1999

Infusions of fluorouracil and leucovorin: effects of the timing and semi-intermittency of drug delivery.

Preclinical and clinical studies have demonstrated that the circadian modulation of 5-FU delivery may reduce toxicities and improve antitumor activity. However, the relative importance of the timing of 5-FU delivery has not been clinically addressed. The aims of this study were to determine the toxicities, the maximum tolerable doses and the activity of a regimen with 5-fluorouracil (5-FU) and leucovorin (LV) administered as a 14-day continuous infusion according to a flat or three different chronomodulated rhythms in patients with metastatic gastrointestinal carcinomas. A total of 113 patients entered the study and their characteristics were comparable among the four groups. Toxicities included mainly stomatitis and diarrhea, and a reduced toxicity was observed in all the three chronogroups that allowed the delivery of higher dose intensities. Response rates were not significantly different among the four groups. These results suggest that a reduction in 5-FU+LV toxicity and an increase in 5-FU dose intensity can be obtained by a nonsinusoidally circadian modulated infusion. However, the reduction in toxicity observed seems to be dependent mainly on the quasi-intermittency and not on the timing of 5-FU+LV delivery.

Adenocarcinoma↗

PubMed1998

Short-term implantation effects of a DCPD-based calcium phosphate cement.

Calcium phosphate cements can be handled in paste form and set in a wet medium after precipitation of calcium phosphate crystals in the implantation site. Depending on the products entering into the chemical reaction leading to the precipitation of calcium phosphates, different phases can be obtained with different mechanical properties, setting times and injectability. We tested a cement composed of a powder, containing beta-tricalcium phosphate (beta-TCP) and sodium pyrophosphate mixed with a solution of phosphoric and sulphuric acids. The cement set under a dicalcium phosphate dihydrate (DCPD)-based matrix containing beta-TCP particles. This was injected with a syringe into a defect drilled in rabbit condyles, the control being an identical defect left empty in the opposite condyle. The condyles were analysed histologically 2, 6 and 18 weeks after implantation. After injection into the bone defect the cement set and formed a porous calcium phosphate structure. Two different calcium phosphate phases with different solubility rates could be identified by scanning electron microscopy (SEM) observation. The less-soluble fragments could be degraded by cell phagocytosis in cell compartments of low pH or integrated in the newly formed bone matrix. The degradation rate of the material was relatively high but compatible with the ingrowth of bone trabeculae within the resorbing material. The ossification process was different from the creeping substitution occurring at the ceramic contact. Bone did not form directly at the cement surface following the differentiation of osteoblasts at the material surface. The trabeculae came to the material surface from the edges of the implantation site. Bone formation in the implantation site was significantly higher than in the control region during the first week of implantation. In conclusion, this material set in situ was well tolerated, inducing a mild foreign-body reaction, which did not impair its replacement by newly formed bone within a few weeks.

Animals↗

PubMed1998

Epirubicin/vinorelbine as first line therapy in metastatic breast cancer.

This study was aimed at investigating the toxicity and activity of the combination epirubicin and vinorelbine in chemotherapy-naive patients with metastatic breast cancer. Fifty-one patients with measurable or evaluable metastatic breast cancer entered the study. The regimen consisted of epirubicin 90 mg/m2 as a slow i.v. infusion on day 1, followed by vinorelbine 25 mg/m2 by 30-minute intravenous infusion on days 1 and 8; the courses were repeated every 21 days for a maximum of 8 cycles. All the patients were assessable for toxicity and 47 were evaluable for response according to the World Health Organization (WHO) criteria. Objective responses were observed in 33 out of 47 evaluable patients (70.2%; 95% C.I. 55.1%-82.6%) with 4 complete (8.5%) and 29 partial responses (61.7%); 11 patients had stable disease (23.4%) and 3 patients progressed while on treatment. The median time to progression was 10 months (range 1-21) and the median overall survival was 23 months (range 2 - 32+). Neutropenia was the most frequent toxicity: a grade 4 neutropenia (WHO) was reported in 70% of 252 courses with a median duration of 3 days (range 1-6). Seventeen episodes of febrile neutropenia were observed but only 1 patient required hospital admission. Other hematologic toxicities were negligible. One patient experienced a paralytic ileus requiring hospitalization; no peripheral neuropathy such as muscle weakness or paresthesia was observed. No treatment-related cardiotoxicity was reported. The encouraging response rate achieved with epirubicin/vinorelbine, the easily manageable toxicities of the combination, and its feasibility in an outpatient setting make this combination worthy of further comparative trials with standard regimens.

Adult↗

PubMed1997

Filgrastim and lack of support of intensive adjuvant chemotherapy for high-risk breast cancer patients.

The capacity of filgrastim to reduce the myelotoxicity of a 16-week intensive chemotherapy regimen has been investigated in 24 operable breast cancer patients with > or = 10 metastatic axillary nodes. Five patients were treated with chemotherapy alone (control group); 19 patients were treated with chemotherapy and filgrastim, 5 microg/kg/day s.c. Six patients in the latter group were treated from day 4 to day 7 (level 1), seven from day 10 to day 13 (level 2), and six from day 4 to day 7 and day 10 to day 13 (level 3). A total of 135 courses were administered: neutropenia was the most severe toxicity, and the prophylactic use of filgrastim does not reduce its severity. Moreover, the dose intensities of antiblastic drugs actually received by the patients were not significantly different in the four study groups. Among the patients treated at level 3, there were three toxic deaths: one patient died because of febrile neutropenia and sepsis, two patients because of ischemic colitis. At a median follow-up of 15 months, 17 patients were alive, and 15 patients were disease free. The use of filgrastim does not ameliorate myelotoxicity and does not allow the administration of the planned doses of antiblastic drugs of a 16-week intensive chemotherapy regimen.

Adult↗

PubMed1996

Accelerated epirubicin-ifosfamide-dacarbazine regimen in patients with adult soft tissue sarcomas.

BACKGROUND: Neutropenia and infections are the dose-limiting toxicities of the EID regimen and can cause dose reduction and/or delay in chemotherapy administration. The purpose of this study was to verify if EID + G-CSF is feasible with an acceptable toxicity in a day hospital setting and if G-CSF could allow an increase in the dose intensity of the EID regimen by shortening the intervals between the courses. PATIENTS AND METHODS: 20 patients with inoperable primary, metastatic or residual disease after surgery or at high risk of recurrence after complete resection, histologically confirmed adult soft tissue sarcoma, entered the study. The dose and schedule of the chemotherapy agents were epidoxorubicin 30 mg/m2 days 1, 2, 3, dacarbazine 300 mg/m2 days 1, 2, 3, and ifosfamide 2500 mg/m2 with mesna uroprotection days 1, 2, 3. G-CSF, 300 micrograms/day subcutaneously, was administered from day 7 for a maximum of 14 days and discontinued when WBC was greater than 10 x 10(9)/L. Courses were repeated "as soon as possible," but never earlier than 10 days from the previous course and at least 48 hours after the last G-CSF injection. RESULTS: A total of 66 EID + G-CSF courses were administered. A G3 and G4 (WHO) neutropenia occurred in 66% of evaluables courses. Nonhematological toxicity was mild. The median number of G-CSF injections required during any interval between courses was 9 (range: 4-14 injections) and the median interval between courses was 21 days (range: 13-36 days). The median dose intensity at the third course of chemotherapy was 1.15 (range: 0.71-1.62). CONCLUSION: This study shows that G-CSF allows a moderate increase in the delivered dose intensity of chemotherapy with an acceptable toxicity. Further studies are needed to investigate if this increase in DI may translate into an improved response rate.

Adolescent↗

PubMed1996

Multicenter, randomized comparative study of two doses of paclitaxel in patients with metastatic breast cancer.

PURPOSE AND METHODS: The objective of this multicenter study was to compare the therapeutic index of two different doses of paclitaxel given as a 3-hour infusion in patients with metastatic breast cancer (MBC), who had failed to respond to previous chemotherapy. A total of 471 patients with MBC were randomized to receive intravenous paclitaxel at a dose of 175 or 135 mg/m2 every 3 weeks. RESULTS: Better treatment results were achieved with high-dose (HD) versus low-dose (LD) paclitaxel: overall response rate, 29% versus 22% (P = .108); complete response (CR) rate, 5% versus 2% (P = .088); median time to disease progression, 4.2 versus 3.0 months (P = .027); and median survival time, 11.7 versus 10.5 months (P = .321). Patients previously exposed or resistant to anthracyclines were as likely to respond as those without such prior exposure. Treatment was well tolerated, as documented by the number of administered treatment courses (median, six v five; range, one 17 v one to 18), the low frequency of dose reductions (14% v 7%, P = .024), and the small number of patients (n = 9 or 4% vn = 5 or 2%) who required treatment discontinuation for adverse reactions. The incidence and severity of neutropenia and peripheral neuropathy were dose-related. After quality-of-life-adjusted time-to-progression analysis, the HD arm (175 mg/m2) retained its advantage over the LD arm (135 mg/m2). CONCLUSION: The results of this trial substantiate the activity of paclitaxel in the treatment of MBC. The observed superior efficacy with a dose of 175 mg/m2 over 135 mg/m2 suggests a dose-effect relationship. The clinical activity in anthracycline-resistant patients is particularly noteworthy. Paclitaxel in breast cancer needs further evaluation in large trials that use combination chemotherapy and involve earlier disease stages.

Adult↗

PubMed1996

[Tracheal intubation with fiberscope in traumatology of the cervical spine. Our clinical experience].

Cervical spine lesions require early stabilisation. The fibroscope was used in order to avoid irreversible damage to the medulla during intubation. Twenty-five patients aged between 18 and 70 years old were treated. Pre-medication and local anesthesia of the nostril, rhinopharynx and oropharynx was performed. Local anesthesia of the hypopharynx was omitted to avoid the tussigenic reflex which is dangerous in this pathology. The patient was then deeply sedated maintaining respiratory activity. The tracheal tube was then introduced into the nostril and the fibroscope was then positioned using this as a guide. Following the insertion of the fibroscope in the trachea, the latter was then used to slide the tracheal tube down. The authors consider this technique to be useful in this pathology since it is risk free if used as described above.

Adult↗

PubMed1995

Interferon-alpha or beta potentiate platinum analogous in human glioblastoma cell lines.

The effect of interferon-alpha or beta on platinum analogues [cisplatin (CDDP) and carboplatin] cytotoxicity was studied in four glioblastoma cell lines (U373MG, T98G, A172 and U118Mg). All cell lines were strongly resistant to the cytotoxic effect of CDDP or carboplatin. Although both interferons were not cytotoxic in all cell lines, they were able to significantly increase the cell platinum-sensitivity. Specifically interferon-alpha increased the magnitude of CDDP-induced DNA interstrand crosslinks. Our findings suggest that interferons are able to induce a very strong potentiation of platinum analogues cytotoxicity in drug-resistant human glioma cell lines.

Antineoplastic Agents↗

PubMed1994

Phase II trial of 5-fluorouracil and the natural l isomer of folinic acid in the treatment of advanced colorectal carcinoma.

Between February 1991 and July 1992, 79 previously untreated patients with metastatic colorectal carcinoma were enrolled in a phase II study of combined 5-fluorouracil (5-FU) and l-folinic acid (FA). 5-FU 370 mg/m2/day was administered for 5 consecutive days as an intravenous (i.v.) bolus injection preceded by l-FA 100 mg/m2/day with the same administration modality. Treatment was given every 4 weeks until progression. 79 patients were evaluable for toxicity and 64 for response. 2 patients (3%) achieved a complete remission and 8 (12.5%) a partial remission, 33 (52%) had stable disease and 21 patients (33%) had progressive disease. Median duration of remission was 32.5 weeks and median survival for all evaluable patients was 64.5 weeks. Substantial to severe side-effects occurred in 39% of patients. Dose-limiting toxicity (grade 3-4) was mainly diarrhoea (18%) and mucositis (15%). Nausea/vomiting, cutaneous toxicity, leucopenia, alopecia and conjunctivitis of grade 3-4 occurred respectively in 6, 4, 2.5, 1 and 1% of cases. Toxicity appeared to be substantially similar to that characteristic of combined 5-FU and the chiral mixture of d,l-FA. Efficacy was within the range of that observed with the 5-FU/d,l-FA combination, although at the lower level.

Adult↗

PubMed1994

High-risk early-stage ovarian cancer. Randomized clinical trial comparing cisplatin plus cyclophosphamide versus whole abdominal radiotherapy.

From 1985 to 1989 70 patients with high-risk FIGO Stage I-II ovarian carcinoma entered a randomized trial comparing chemotherapy (CT: cisplatin 50 mg/m2 + cyclophosphamide 600 mg/m2 day 1 every 28 days for 6 courses) versus whole abdominal radiotherapy (WAR) given according to the open-field technique (43.2 Gy/24 fractions to the pelvis and 30.2 Gy to the upper abdomen). Protocol violations occurred in 8 patients randomized to WAR who received CT because of their own and/or physician's decision. Since protocol compliance was poor and accrual low the study was prematurely closed. Treatment-related toxicity for patients receiving CT was mild and tolerable, consisting chiefly of controllable grade 3 emesis (71%). Grade 3-4 diarrhea was experienced by 28% of patients treated with WAR; severe enteritis requiring hospitalization was observed in 2 patients. Late bowel obstruction requiring surgery was observed in 1 patient. At a median follow-up of 60 months, 21 patients died and 23 relapsed. Five-year survival was 71% and 53% (p = .16), while relapse-free survival was 74% and 50% (p = .07) for CT and WAR, respectively. Although no firm conclusion can be drawn from the present study, a short-term CT, including cisplatin, appears a safe treatment in comparison to WAR.

Abdomen↗

PubMed1994

[Subannular pseudoaneurysm of the left ventricle complicating mitral valve replacement; apropos of a case].

The authors report the case of a 72 year old woman with a Carpentier-Edwards bioprosthesis implanted in March 1981 for severe mitral stenosis, asymptomatic until 1986. The progression of effort dyspnoea with prosthetic valve dysfunction despite digitalo-diuretic therapy and severe ventricular subannular pseudoaneurysm. Doppler echocardiography and cardiac catheterisation and angiography confirmed the mitral subannular pseudoaneurysm and led to surgical cure of this fibrous structure and implantation of a mechanical mitral valve prosthesis. This complication of mitral valve replacement is a cause of pseudoaneurysm which should not be overlooked.

Aged↗

PubMed1994

Immunoscintigraphy of Pneumocystis carinii pneumonia in AIDS patients.

UNLABELLED: The diagnosis of Pneumocystis carinii pneumonia (PCP) currently relies upon cytological demonstration of the organism in sputum or bronchoscopy specimens. The purpose of this study was to develop a radiolabeled monoclonal antibody (Mab) against Pneumocystis carinii (P. carinii) and to evaluate its use for imaging PCP. METHODS: We studied 16 HIV-infected patients with pneumonia in order to evaluate a new Mab-based imaging method for diagnosing PCP. Most patients were managed for opportunistic pneumonia associated with AIDS, including standard cytological tests, and, in all cases, intensive chemotherapy. Prior to the clinical study, the Mab raised to P. carinii was shown to react with human P. carinii but not with rat P. carinii or human white blood cells. RESULTS: After labeling a 1-mg Mab Fab' fragment with 30 mCi of 99mTc, the presence or absence of PCP could be confirmed in six of seven or seven of eight assessable patients, respectively, by external photoscanning within 24 hr. This shows a sensitivity of 85.7% and a specificity of 86.7%. CONCLUSION: Our findings suggest that PCP can be diagnosed by a noninvasive imaging method employing a small dose of a 99mTc-labeled Mab showing specificity for the infectious organism, since patients with P. carinii-free pneumonia were correctly negative in 87.5% of cases. Rapid diagnosis and organ-localization of other infectious lesions with organism-specific, radiolabeled Mabs may be feasible.

AIDS-Related Opportunistic Infections↗

PubMed1993

Potentiation of tumour necrosis factor-mediated cell killing by VP16 on human ovarian cancer cell lines. In vitro results and clinical implications.

Synergism between recombinant human tumour necrosis factor (rHuTNF) and DNA topoisomerase II inhibitor VP16 during the killing of cells has been studied in six human ovarian cancer cell lines (A2774, A2780, SW626, IGROV-1, SKOV3, Pa1) and a cervical carcinoma cell line (Me180). Studies were performed using an assay of colony formation inhibition (drug treatment for 1 h) and a growth inhibition assay (continuous exposure for 20 h). Concomitant treatment of cells with VP16+rHuTNF enhanced cell killing in all the cell lines tested--an effect observed in both short- and long-term cytotoxicity assays. This study suggests that the activity of VP16 in ovarian cancer cell lines might be enhanced by rHuTNF in in vitro models.

Cell Survival↗

PubMed1993

A study of structure and degradation of nonpolymeric biomaterials implanted in bone using reflected and transmitted light microscopy.

Orthopedic biomaterials currently are made of metal alloy coated with one or more thin layers of dense or porous ceramic or metal. Sections of these materials implanted in human bone were made without altering the implant or bone-implant interfaces. Bone containing an implant was fixed and then embedded in polymethylmethacrylate. Thick sections were made using a cooled, low speed diamond saw, then ground and polished. Some were stained by fuchsin-toluidine staining solution, others were acid etched to reveal the structure of the metal contained in the prosthesis. Observation by reflected and transmitted light microscopy revealed microstructure of the implant material as well as features of the surrounding tissues.

Alloys↗

PubMed1993

Reversal of "atypical"-multidrug resistance by recombinant human tumor necrosis factor in the human ovarian cancer cell line A2780-DX3.

A2780 human ovarian cancer cell line and its multidrug resistant counterpart A2780-DX3 were utilized for this in vitro study. A2780-DX3 is resistant in various degrees to several topoisomerase II inhibitors but sensitive to vinca alkaloids. Simultaneous treatment of the A2780-DX3 line with 1000 U/mL rHuTNF largely reverses resistance to most topoisomerase II inhibitors. By itself, 1000 U/mL rHuTNF is not toxic to the resistant line. Uptake and retention of [3H]-Mitoxantrone are not modified by rHuTNF, whereas rHuTNF is very active in potentiating the effects of Mitoxantrone. After treatment with topoisomerase II inhibitors, Doxorubicin, Mitoxantrone, or VP16, rHuTNF restores DNA-SSB and DNA-protein cross-links in the resistant line to the level of the wild type. The cleavage activity of topoisomerase II in the resistant line is about 40% of the level present in the parental line. Five minutes after the addition of 1000 U/mL of rHuTNF, the cleavage activity in the resistant line is about 85% of the level present in the parental line. The catalytic activity of topoisomerase II is only 15% lower in the resistant line, but it is increased by about 50% 5 min after the addition of rHuTNF to the resistant line. These effects are transient and cannot be observed after 30 min. These transient direct effects of rHuTNF on topoisomerase II could be associated with its ability to restore sensitivity to inhibitors of topoisomerase II in the A2780-DX3 line.

Antineoplastic Agents↗