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J Alexandre

Publications and source records attributed to J Alexandre.

At least 19 recordsLinked to original sources
PubMed2006

Relationship between cytochrome 3A activity, inflammatory status and the risk of docetaxel-induced febrile neutropenia: a prospective study.

BACKGROUND: We hypothesized that cancer-related inflammation might increase the risk of febrile neutropenia (FN) induced by docetaxel (DCX, Taxotere), by both affecting the exposure to DCX and the tissue sensitivity. PATIENTS AND METHODS: Advanced cancer patients with normal liver function, performance status (PS)<3, were included. Cytochrome P450 3A (CYP 3A) activity was estimated before the first cycle of DCX by a single determination of midazolam plasma concentration, 4 hours after 0.015 mg/kg i.v. bolus. Following the first cycle of 75-100 mg/m2 DCX, clearance and area under the concentration versus time curve (AUC) were estimated using a limited sampling strategy. RESULTS: Among 56 assessable patients, 7 FNs occurred after first cycle (13%). In univariate analysis, high midazolam concentration and free DCX AUC were associated with severe neutropenia and FN. In addition to DCX exposure-related parameters, the risk of FN was also correlated with poor PS, baseline lymphopenia and lung cancer, while high ferritin level, indicator of an inflammatory state, reached borderline significance (P=0.07). By multivariate analysis, total DCX AUC and baseline lymphopenia were associated with FN. High midazolam concentration was correlated with elevated ferritin level (r=0.32; P=0.02). CONCLUSION: Inflammatory status and lymphocyte count should be included in the evaluation of the benefice/risk ratio before the initiation of DCX.

Aged↗
PubMed2006

Pharmacokinetics and toxicity of docetaxel: role of CYP3A, MDR1, and GST polymorphisms.

OBJECTIVE: Patients initiating docetaxel chemotherapy were genotyped for CYP3A4, CYP3A5, MDR1, GSTM1, GSTT1, GSTM3, and GSTP1 to identify variability factors of docetaxel pharmacokinetics and toxicity. METHODS: Genotyping was performed by direct sequencing (CYP3A4), real-time polymerase chain reaction (CYP3A5), and polymerase chain reaction-restriction fragment length polymorphism (MDR1 and GST). The clearance and area under the curve of docetaxel were calculated by use of a Bayesian approach. Absolute neutrophil count was recorded twice weekly. RESULTS: With regard to the pharmacokinetic analysis, 58 patients were included. CYP3A4*1B carriers (*1A/*1B, n=4), who are also CYP3A5*1/*3 carriers, had a significantly higher clearance and lower dose-normalized area under the curve of docetaxel than those with the wild genotype (*1A/*1A, n=53): 55.2+/-13.5 L/h versus 37.3+/-11.7 L/h (P=.01) and 31.4+/-6.2 (microg . h/L)/(mg/m(2)) versus 52.7+/-18.2 (microg . h/L)/(mg/m(2)) (P=.005), respectively. No influence of MDR1 was evidenced. With regard to the pharmacodynamic analysis, febrile neutropenia occurred more frequently in GSTP1*A/*B carriers (31.6% versus 3.7% in *A/*A carriers and 0% in *A/*C, *B/*B, and *B/*C carriers) (P=.037). Grade 3 neutropenia occurred more frequently in 3435TT MDR1 genotype carriers: TT, 100%; CT, 77.3%; and CC, 54.5% (P=.046). No influence of GSTM1, GSTT1, or GSTM3 polymorphisms was evidenced on docetaxel toxicity. CONCLUSIONS: Patients carrying the CYP3A*1B allele may have enhanced docetaxel clearance and may be underexposed, whereas those carrying GSTP1*A/*B and 3435TT genotypes may have excessive hematologic toxicity. Further studies are warranted to determine the usefulness of genotyping before docetaxel treatment.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2005

[Proteasome inhibitors].

INTRODUCTION: Proteasome is involved in cell cycle and apoptosis regulation. Its deregulation could participate to oncogenesis. EXEGESIS: Bortezomib is the first proteasome inhibitor to reach clinical development. Its main adverse events are asthenia, thrombocytopenia and cumulative neurotoxicity which can limits long term use. As single agent, bortezomib displays antitumoral effects in refractory multiple myeloma and mantle cell lymphoma but has only modest activity in solid tumors. Preclinical data suggest that bortezomib could enhance antitumor activity of cytotoxics. CONCLUSION: Proteasome inhibition is a promising therapeutic pathway, especially in lymphoid malignancies.

Adenocarcinoma↗
PubMed2004

Phase II study of ecteinascidin-743 in advanced pretreated soft tissue sarcoma patients.

PURPOSE: A multicenter phase II study evaluating efficacy, safety, and pharmacokinetics of ecteinascidin-743 (ET-743) in pretreated advanced soft tissue sarcoma patients. PATIENTS AND METHODS: Patients received ET-743 1,500 microg/m(2) (24-hour intravenous infusion) every 3 weeks (group 1, 26 patients with one to two prior single agents or one previous combination chemotherapy; group 2, 28 patients with three or more prior single agents or two or more previous combination chemotherapies). Results Patients (30 women, 24 men) had a median age of 48 years (range, 22 to 71 years); 41% had leiomyosarcoma (eight of 22 of uterine origin), a median of two involved organs (range, one to four), and 93% had documented progressive disease at study entry. Patients received a median of three cycles (range, one to 20); 28% received six or more cycles. Fifty-two patients were assessable for response (WHO criteria): two partial responses, four minor responses, and nine with stable disease (> or = 6 months). Three patients were rendered tumor free after surgery. Median progression-free survival was 1.9 months (range, 0.69 to 17.90 months); 24% of patients were progression free at 6 months. Median survival was 12.8 months, with 30% of patients alive at 2 years. Four patients withdrew because of treatment-related toxicity. Two treatment-related deaths occurred (renal failure and febrile neutropenia, and rhabdomyolysis and decompensated cirrhosis, respectively) that were probably related to protocol eligibility violations. Reversible grade 3 to 4 AST or ALT occurred in 50% of patients and grade 3 to 4 neutropenia occurred in 61% of patients, with six episodes of febrile neutropenia. Nausea, vomiting, and asthenia were prevalent but mild and manageable. CONCLUSION: With a 4% overall response rate (95% CI, 0.5 to 12.8) and an 11% rate of third-party-verified tumor regression (overall response rate + minor response), ET-743 has a 24% 6-month disease progression control rate, confirming evidence of antitumoral activity and a manageable safety profile in patients experiencing disease progression with pretreated soft tissue sarcoma.

Adult↗
PubMed2003

FORRepeats: detects repeats on entire chromosomes and between genomes.

MOTIVATION: As more and more whole genomes are available, there is a need for new methods to compare large sequences and transfer biological knowledge from annotated genomes to related new ones. BLAST is not suitable to compare multimegabase DNA sequences. MegaBLAST is designed to compare closely related large sequences. Some tools to detect repeats in large sequences have already been developed such as MUMmer or REPuter. They also have time or space restrictions. Moreover, in terms of applications, REPuter only computes repeats and MUMmer works better with related genomes. RESULTS: We present a heuristic method, named FORRepeats, which is based on a novel data structure called factor oracle. In the first step it detects exact repeats in large sequences. Then, in the second step, it computes approximate repeats and performs pairwise comparison. We compared its computational characteristics with BLAST and REPuter. Results demonstrate that it is fast and space economical. We show FORRepeats ability to perform intra-genomic comparison and to detect repeated DNA sequences in the complete genome of the model plant Arabidopsis thaliana.

Algorithms↗
PubMed2003

Evaluation of the nutritional and inflammatory status in cancer patients for the risk assessment of severe haematological toxicity following chemotherapy.

BACKGROUND: The toxicity outcome of cancer patients receiving chemotherapy is difficult to predict. In this study the influence of malnutrition and inflammation on acute haematological toxicity was investigated. PATIENTS AND METHODS: Between January 1999 and January 2000, 48 consecutive cancer patients experienced severe haematological toxicity (SHT), either neutropenic fever or severe thrombocytopenia, following various chemotherapy regimens. Their baseline characteristics were compared with those of 59 control patients. Previous chemotherapy regimens, type of chemotherapy, performance status (PS), calculated creatinine clearance, bilirubin, C-reactive protein (1), alpha-1 acid glycoprotein (2), albumin (3), pre-albumin (4) and the nutritional and inflammatory status (NIS) ratio [NIS = (1 x 2)/(3 x 4)] were studied. Statistical analysis was carried out using either a t-test or a chi-square test. A receiver operating characteristic (ROC) curve determined the cut-off value for NIS. RESULTS: Patients experiencing SHT had a higher PS (P <0.001), inflammatory serum protein levels (P <0.001) and NIS ratio (P <0.0001), but lower haemoglobin (P <0.05) and serum-albumin levels (P <0.0001). Using a cut-off of 0 or 1 for PS and 1 for NIS, sensitivity was 98%, 43% and 89%; specificity was 38%, 90% and 66%, respectively. In 37 patients treated with topotecan as single agent, the determinants for SHT were PS (P <0.0001) and NIS (P <0.0001). CONCLUSIONS: Altered nutritional and inflammatory status correlates with increased risk of severe haematological toxicity following anticancer chemotherapy.

Adult↗
PubMed2003

Phase I population pharmacokinetics of irofulven.

Our aim was to develop a population pharmacokinetic model for irofulven and to assess covariates that might affect irofulven pharmacokinetics. Irofulven was administered by 5- or 30-min i.v. infusion to cancer patients during a phase I study. Blood samples were collected over 4 h. Plasma samples were analyzed to quantitate irofulven by high-performance liquid chromatography. Population pharmacokinetic analysis was performed using a non-linear mixed effects modeling program, MP2. Fifty-nine patients were available for pharmacokinetic analysis. Irofulven plasma concentration-time profiles were best described by a two-compartment pharmacokinetic model. Clearance and central volume of distribution were not significantly influenced by individual characteristics, i.e. body weight (BW), body surface area (BSA), age and gender. Final parameter estimates of clearance and central volume of distribution were 616 l/h and 37 l, respectively, resulting in a very short terminal half-life of less than 10 min. A relatively high level of variability was observed in irofulven pharmacokinetics, which was mainly due to a significant residual variability, 39%. For a 30-min irofulven infusion, the optimal sampling schedule for clearance estimation using the Bayesian method was the three time points 0.35-0.45, 0.80 and 1-1.2 h from the beginning of a 30-min infusion. We conclude that after i.v. infusion of irofulven, plasma clearance was high and not dependent upon patient age, gender, BSA or BW.

Adult↗
PubMed2001

Stage I non-seminomatous germ-cell tumours of the testis: identification of a subgroup of patients with a very low risk of relapse.

There is no consensus about a reproducible prognostic model capable of distinguishing between clinical stage I non-seminomatous germ cell tumour (NSGCT) carrying a high and low risk of relapse. The aim of this study was to assess the prognostic value of histological parameters in patients with stage I NSGCT undergoing surveillance after orchiectomy. We retrospectively evaluated tumour specimens from 88 consecutive stage I NSGCT patients undergoing surveillance in our institution between 1984 and 1996. 24 patients relapsed (27%). Multivariate analysis singled out vessel invasion (VI) (relative risk (RR)=3.8; 95% confidence interval (CI) 1.4-10.4) and the presence of mature teratoma (RR= 0.2; 95% CI 0.1-0.6) as independently correlated with relapse-free survival (RFS). Patients can be classified accordingly into three prognostic groups with a low (27 patients with mature teratoma but without VI), intermediate (34 patients with both VI and mature teratoma or with neither VI or mature teratoma) and a high risk (23 patients with VI, but without mature teratoma) of relapse. Relapse rates in these three groups were 0%, 29% (95% CI: 23-35%) and 61% (95% CI: 55-67%), respectively. This prognostic index, based on two standard pathological parameters, identified a subgroup with a very low risk of relapse that represents approximately one third of stage I patients. Patients who belong to this subgroup should be managed by surveillance only, instead of retroperitoneal lymph node dissection (RPLND) or adjuvant chemotherapy.

Adolescent↗
PubMed2000

Factors predicting for efficacy and safety of docetaxel in a compassionate-use cohort of 825 heavily pretreated advanced breast cancer patients.

PURPOSE: To identify predictive factors for efficacy and safety in advanced breast cancer (ABC) patients treated in the French compassionate-use docetaxel program. PATIENTS AND METHODS: A total of 825 ABC patients treated with docetaxel (100 mg/m(2) every 3 weeks) were source-reviewed and analyzed for prognostic factors associated with overall response rate (ORR), time to treatment failure (TTF), overall survival (OS), febrile neutropenia, mucositis, and severe fluid retention syndrome by univariate and multivariate analysis. RESULTS: The ORR was 22.9% (95% confidence interval, 20.2% to 26.2%). The median TTF and OS were 4.0 and 9.8 months, respectively. By multivariate analysis, secondary anthracycline-resistant disease was significantly associated (P <. 05) with lower ORR and shorter TTF and OS, whereas anthracycline-refractory disease was associated with shorter OS. Poor performance status was associated with lower ORR, shorter TTF, and shorter OS. Liver dysfunction (transaminase levels > 1.5 times the upper limit of normal [ULN] and alkaline phosphatase [AP] level > three times ULN) and time since first relapse less than 24 months were associated with shorter TTF and OS. Other significant correlations included the following: elevated CA 15-3 serum level with lower ORR; more than two involved sites, and minor transaminase and AP level abnormalities with shorter OS; and no previous chemotherapy for ABC with shorter TTF. According to multivariate analysis, ORR, TTF, and OS were not decreased in patients with liver metastases but without liver dysfunction. CONCLUSION: Docetaxel activity was maintained in heavily pretreated ABC patients and in those with liver metastasis; docetaxel must be used cautiously, however, in patients with liver dysfunction in whom high morbidity risk necessitates strict adherence to dose-adaptation guidelines.

Anthracyclines↗
PubMed1999

Osmotic water permeability of isolated protoplasts. Modifications during development

A transference chamber was developed to measure the osmotic water permeability coefficient (Pos) in protoplasts 40 to 120 μm in diameter. The protoplast was held by a micropipette and submitted to a steep osmotic gradient created in the transference chamber. Pos was derived from the changes in protoplast dimensions, as measured using a light microscope. Permeabilities were in the range 1 to 1000 μm s-1 for the various types of protoplasts tested. The precision for Pos was </=40%, and within this limit, no asymmetry in the water fluxes was observed. Measurements on protoplasts isolated from 2- to 5-d-old roots revealed a dramatic increase in Pos during root development. A shift in Pos from 10 to 500 μm s-1 occurred within less than 48 h. This phenomenon was found in maize (Zea mays), wheat (Triticum aestivum), and rape (Brassica napus) roots. These results show that early developmental processes modify water-transport properties of the plasma membrane, and that the transference chamber is adapted to the study of water-transport mechanisms in native membranes.

Journal Article↗
PubMed1999

Tissue-specific changes in RNA synthesis in vivo during anoxia in crucian carp.

The overall energy budget for protein synthesis (i.e., transcription plus translation) is thought to consist of fixed and variable components, with RNA synthesis accounting for the former and protein synthesis the latter. During anoxia, the downregulation of protein synthesis (i.e., the variable component), to reduce energetic demand, is an important aspect of survival in crucian carp. The present study examines RNA synthesis during anoxia by labeling with [(3)H]uridine. A novel synthesis rate calculation is presented, which allows for the tissue-specific salvage of uridine, with synthesis rates finally expressed relative to DNA. After 48 h anoxia, the decline (29%) in brain RNA synthesis and increases in the heart and liver (132 and 871%, respectively) support known RNA functions during hypoxic/anoxic survival. This study provides evidence that, in an anoxia-tolerant species, survival mechanisms involving RNA are able to operate because tissue-specific restructuring of the RNA synthesis process enables fixed synthesis costs to be maintained; this may be as vital to survival as exploiting the variable energetic demand of protein synthesis.

Animals↗
PubMed1999

[Rapamycin and CCI-779].

Rapamycin (sirolimus) is a macrolide, related to cyclosporine with immunosuppressive properties and antiproliferative activity in various human tumor cells lines and tumor xenograft models. The cytosolic kinase mTOR which controls the initiation of the translation of messenger RNA is the main known target of rapamycin. During clinical studies, rapamycin given by oral route as immunosuppressant did not show dose-limited toxicity and only asymptomatic thrombopenia and hyperlipemia were observed. In murine models, best antitumoral activity was observed using parental routes. CCI-779, an analog formulated for intravenous use has antitumor activity without significant immunosuppressive property in mice and is currently in phase I trials in man.

Administration, Oral↗