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Biomedical subjects

N Barbier

Publications and source records attributed to N Barbier.

12 recordsLinked to original sources

[Pilot study of conformal intensity modulated radiation therapy for localized prostate cancer].

PURPOSE: - To report our experience on treatment planning and acute toxicity in 16 patients suffering from clinically localized prostate cancer treated with high-dose intensity-modulated radiation therapy (IMRT). PATIENTS AND METHODS: - Between March 2001 and October 2002, 16 patients with clinically localized prostate cancer were treated with IMRT. Treatment planning included an inverse-planning approach, and the desired beam intensity profiles were delivered by dynamic multileaf collimation. All patients received the entire treatment course with IMRT to a prescribed dose of 78 Gy. All IMRT treatment plans were compared with a theoretical conventional three-dimensional conformal radiation therapy (3D-CRT). Acute lower gastro-intestinal (GI) and genito-urinary (GU) toxicity was evaluated in all patients and graded according to the Common Toxicity Criteria for Adverse Events version 3.0 (CTCAE v. 3.0). A relationship between dose volume and clinical toxicity was evaluated. RESULTS: - Ninety-five percent of the PTV2 received more than 76 Gy using IMRT or 3D-CRT with no difference between both methods. The dose-volume histogram mean obtained for the PTV2 was not different between IMRT and 3D-CRT. IMRT improved homogeneity of the delivered dose to the PTV2 as compared with 3D-CRT (7.5 vs 9%, respectively). Ninety-five percent of the PTV1 received 5 Gy more using IMRT with protection of the bladder and the rectum walls. The benefit was considered below 75 and 70 Gy for the wall of the bladder and the rectum, respectively. Grade 2 GI and GU toxicity was observed in four (25%) and five (31%) patients, respectively. No grade 3 toxicity was observed. There was a trend towards a relationship between the mean rectal dose and acute rectal toxicity but without statistical significant difference (P =0.09). CONCLUSION: - Dose escalation with IMRT is feasible with no grade 3 or higher acute GI or GU toxicity. Examination of a larger cohort and longer-term follow-up are warranted in the future.

Adenocarcinoma↗

Long-term safety and tolerability of pimecrolimus cream 1% and topical corticosteroids in adults with moderate to severe atopic dermatitis.

OBJECTIVE: This randomized, double-blind, multi-centre study compared the long-term safety and tolerability of pimecrolimus cream 1% and topical corticosteroids (TCS) in 658 adults with moderate-severe atopic dermatitis (AD). METHODS: Patients applied either pimecrolimus or TCS (i.e. 0.1% triamcinolone acetonide cream and/or 1% hydrocortisone acetate cream) twice daily to all affected areas until complete clearance or for up to 1 year. The study was approved by the institutional review board or ethics committee at each centre. RESULTS: A majority of patients treated with either pimecrolimus or TCS used the drug on a continuous basis over 1 year. In patients who had >30% of the body surface involved by AD, the incidence rate of all skin infections was significantly lower in the pimecrolimus group than in the TCS group (95% CI of the treatment difference: -25.3% to -3.4%). The most frequent application site reaction was burning (25.9% of patients on pimecrolimus and 10.9% on TCS), which was transient and mild-moderate in most cases. Three TCS-treated patients reported skin striae. There were no treatment-related serious or clinically significant systemic adverse events. Efficacy was better in patients on continuous TCS therapy, although patients completing the study were similarly well-controlled in both groups. About 42% of the pimecrolimus-treated patients were maintained for 1 year without TCS. CONCLUSION: Pimecrolimus demonstrated a favourable safety profile when used to treat adult patients with moderate-severe AD for up to 1 year. A significant proportion of patients could be maintained without TCS for a year.

Administration, Cutaneous↗

Validation of the Eczema Area and Severity Index for atopic dermatitis in a cohort of 1550 patients from the pimecrolimus cream 1% randomized controlled clinical trials programme.

OBJECTIVE: To validate the Eczema Area and Severity Index (EASI) by assessing its internal consistency, reliability and sensitivity to change and by correlating it to other efficacy parameters. DESIGN: Three short-term and two long-term double-blind, randomized, controlled trials, performed in 138 study centres in Europe, South Africa, Australia, New Zealand, and North and South America. PATIENTS AND METHODS: In total, 1550 paediatric patients with atopic dermatitis were studied. Pimecrolimus cream 1% was used twice daily to treat atopic dermatitis. The three short-term studies were placebo controlled. The two long-term studies evaluated the efficacy and safety of early intervention with pimecrolimus to prevent progression to disease flare requiring topical corticosteroid treatment, compared with reactive treatment with topical corticosteroids to treat flares of atopic dermatitis. MAIN OUTCOME MEASURES: Five parameters were measured: (i) the EASI (range of score 0-72); (ii) Investigators' Global Assessment (IGA), using a six-point (0-5) scale; (iii) patients' assessment, using a four-point (0-3) scale; (iv) severity of pruritus assessment, using a four-point (0-3) scale; and (v) a quality-of-life evaluation. RESULTS: The EASI score varied in parallel and in correlation with the IGA, pruritus and patients' assessment. All correlation coefficients were statistically different from 0 (P < 0.05). The EASI correlated well with each of its components, and all paired comparisons were within agreed limits. The EASI showed good sensitivity to changes in severity. CONCLUSION: In a large, multinational patient population with atopic dermatitis, the EASI showed good validity, reliability and sensitivity to change and correlated well with other measures of severity. It therefore qualifies as a valid method of assessment in clinical studies of atopic dermatitis.

Adolescent↗

A phase 1-2 clinical trial of gene therapy for recurrent glioblastoma multiforme by tumor transduction with the herpes simplex thymidine kinase gene followed by ganciclovir. GLI328 European-Canadian Study Group.

This study has investigated the effects of herpes simplex thymidine kinase gene (HSV-tk) transfer followed by ganciclovir treatment as adjuvant gene therapy to surgical resection in patients with recurrent glioblastoma multiforme (GBM). The study was open and single-arm, and aimed at assessing the feasibility and safety of the technique and indications of antitumor activity. In 48 patients a suspension of retroviral vector-producing cells (VPCs) was administered by intracerebral injection immediately after tumor resection. Intravenous ganciclovir was infused daily 14 to 27 days after surgery. Patients were monitored for adverse events and for life by regular biosafety assaying. Tumor changes were monitored by magnetic resonance imaging (MRI). Reflux during injection was a frequent occurrence but serious adverse events during the treatment period (days 1-27) were few and of a nature not unexpected in this population. One patient experienced transient neurological disorders associated with postganciclovir MRI enhancement. There was no evidence of replication-competent retrovirus in peripheral blood leukocytes or in tissue samples of reresection or autopsy. Vector DNA was shown in the leukocytes of some patients but not in autopsy gonadal samples. The median survival time was 8.6 months, and the 12-month survival rate was 13 of 48 (27%). On MRI studies, tumor recurrence was absent in seven patients for at least 6 months and for at least 12 months in two patients, one of whom remains recurrence free at more than 24 months. Treatment-characteristic images of injection tracks and intracavity hemoglobin were apparent. In conclusion, the gene therapy is feasible and appears to be satisfactorily safe as an adjuvant to the surgical resection of recurrent GBM, but any benefit appears to be marginal. Investigation of the precise effectiveness of this gene therapy requires prospective, controlled studies.

Adult↗

Random amplified polymorphic DNA typing versus pulsed-field gel electrophoresis for epidemiological typing of vancomycin-resistant enterococci.

Sixty vancomycin-resistant vanA mutant Enterococcus faecium (VRE) isolates, collected during a 40-month period from 48 patients hospitalized in a French Cancer Referral Center, were typed by using random amplified polymorphic DNA (RAPD), and the results were compared with those previously obtained by typing with SmaI pulsed-field gel electrophoresis (PFGE), which is currently recognized as the "gold standard." The discriminating power of RAPD typing, with seven primers and 11 combinations of primers, was tested on 18 strains, and only the most discriminating combination was further tested on the whole collection. We compared the epidemiological usefulness of RAPD typing of 60 clinical VRE isolates with that of SmaI PFGE typing. With primers AP4 and ERIC1R, RAPD generated 30 patterns versus the 36 patterns generated by SmaI PFGE. However, this did not hamper the epidemiologically correct clustering of 15 related strains and the detection of multiple colonization in nine patients. We conclude that this simple RAPD technique is well suited to the epidemiological typing of VRE and the monitoring of its nosocomial spread.

Bacterial Typing Techniques↗

Germ-line p53 mutations in 15 families with Li-Fraumeni syndrome.

Germ-line mutations of the tumor-suppressor gene p53 have been observed in some families with the Li-Fraumeni syndrome (LFS), a familial cancer syndrome in which affected relatives develop a diverse set of early-onset malignancies including breast carcinoma, sarcomas, and brain tumors. The analysis of the p53 gene in LFS families has been limited, in most studies to date, to the region between exon 5 and exon 9. In order to determine the frequency and distribution of germ-line p53 mutations in LFS, we sequenced the 10 coding exons of the p53 gene in lymphocytes and fibroblast cell lines derived from 15 families with the syndrome. Germ-line mutations were observed in eight families. Six mutations were missense mutations located between exons 5 and 8. One mutation was a nonsense mutation in exon 6, and one mutation was a splicing mutation in intron 4, generating aberrant shorter p53 RNA(s). In three families, a mutation of the p53 gene was observed in the fibroblast cell line derived from the proband. However, the mutation was not found in affected relatives in two families and in the blood from the one individual, indicating that the mutation probably occurred during cell culture in vitro. In four families, no mutation was observed. This study indicates that germ-line p53 mutations in LFS are mostly located between exons 5 and 8 and that approximately 50% of patients with LFS have no germ-line mutations in the coding region of the p53 gene.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Germline mutations of the p53 tumor suppressor gene in children with osteosarcoma.

PURPOSE: We investigated the possibility that a significant proportion of children with osteosarcoma harbor germline mutations of the p53 tumor suppressor gene and, therefore, this subgroup of pediatric cancer patients should be considered for large-scale predictive testing. PATIENTS AND METHODS: Genomic DNA extracted from peripheral-blood leukocytes from 235 unselected children with osteosarcoma from 33 institutions were screened for the presence of germline p53 mutations using constant denaturant gel electrophoresis (CDGE). Exons 5 through 8 were evaluated in all patients and exon 2 and exon 9 were analyzed in 59 and 95 patients, respectively. Those samples that showed aberrant migration on CDGE were sequenced or analyzed by restriction enzyme digestion of polymerase chain reaction (PCR) products to confirm the nature of the gene alteration. RESULTS: In 18 samples, CDGE showed fragments of the p53 gene with altered electrophoretic mobilities compared with wild-type p53. DNA sequencing showed that 11 samples had an identical, previously described polymorphism. The other seven contained heterozygous p53 mutations located in exon 5 (n = 3), exon 6 (n = 1), exon 7 (n = 1), and exon 8 (n = 2). Six alterations were missense mutations and one was a nonsense mutation. Three of these patients had first-degree relatives with cancer. One of these three kindreds had a family history consistent with Li-Fraumeni syndrome (LFS). CONCLUSION: We identified germline p53 mutations in seven of 235 (3.0%) children with osteosarcoma. Four of these mutations were found in patients who did not have first-degree relatives with cancer. Although genetic transmission of the altered p53 gene could not be tested in this survey because of how it was designed, it is possible that predictive testing for p53 mutations could identify unaffected relatives of gene carriers who also have a high risk for the development of cancer. This study provides evidence for the importance of considering children with osteosarcoma for predictive testing for germline p53 mutations.

Base Sequence↗

A functional screen for germ line p53 mutations based on transcriptional activation.

Germ line p53 mutations represent a genetic predisposition for cancer development. At the present time, their detection requires extensive work and their functional significance must be documented. Therefore, we have designed a simple biological assay which detects functionally significant germ line p53 mutations. This assay is based on the cloning of the patient's p53 complementary DNA into a eukaryotic expression vector followed by the cotransfection into human cells of the recombinant vector with a reporter plasmid for the transcriptional activity of p53. This assay potentially offers a powerful method to screen fibroblasts or lymphocytes from patients for germ line mutations which inactivate the p53 tumor suppressor gene.

Base Sequence↗

Germ-line mutations of the p53 tumor suppressor gene in patients with high risk for cancer inactivate the p53 protein.

Germ-line mutations in the p53 tumor suppressor gene have been observed in patients with Li-Fraumeni syndrome, brain tumors, second malignancies, and breast cancers. It is unclear whether all of these mutations have inactivated p53 and thereby provide an increased risk for cancer. Therefore, it is necessary to establish the biological significance of these germ-line mutations by the functional and structural analysis of the resulting mutant p53 proteins. We analyzed the ability of seven germ-line mutant proteins observed in patients with Li-Fraumeni syndrome, second primary neoplasms, or familial breast cancer to block the growth of malignant cells and compared the structural properties of the mutant proteins to that of the wild-type protein. Six of seven missense mutations disrupted the growth inhibitory properties and structure of the wild-type protein. One germ-line mutation retained the features of the wild-type p53. Genetic analysis of the breast cancer family in which this mutation was observed indicated that this germ-line mutation was not associated with the development of cancer. These results demonstrate that germ-line p53 mutations observed in patients with Li-Fraumeni syndrome and with second malignancies have inactivated the p53 tumor suppressor gene. The inability of the germ-line p53 mutants to block the growth of malignant cells can explain why patients with these germ-line mutations have an increased risk for cancer. The observation of a functionally silent germ-line mutation indicates that, before associating a germ-line tumor suppressor gene mutation with cancer risk, it is prudent to consider its functional significance.

Base Sequence↗

Germline mutations of the p53 tumor-suppressor gene in children and young adults with second malignant neoplasms.

BACKGROUND: Acquired mutations in the p53 tumor-suppressor gene have been detected in several human cancers, including colon, breast, and lung cancer. Inherited mutations (transmitted through the germline) of this gene can underlie the Li-Fraumeni syndrome, a rare familial association of breast cancer in young women, childhood sarcomas, and other malignant neoplasms. We investigated the possibility that p53 mutations in the germline are associated with second primary cancers that arise in children and young adults who would not be considered as belonging to Li-Fraumeni families. METHODS: Genomic DNA was extracted from the blood leukocytes of 59 children and young adults with a second primary cancer. The polymerase chain reaction, in combination with denaturant-gel electrophoresis and sequencing, was used to identify p53 gene mutations. RESULTS: Mutations of p53 that changed the predicted amino acid sequence were identified in leukocyte DNA from 4 of the 59 patients (6.8 percent). In three cases, the mutations were identical to ones previously found in the p53 gene. The fourth mutation was the first germline mutation to be identified in exon 9, at codon 325. Analysis of leukocyte DNA from close relatives of three of the patients indicated that the mutations were inherited, but cancer had developed in only one parent at the start of the study. CONCLUSIONS: These findings identify an important subgroup of young patients with cancer who carry germline mutations in the p53 tumor-suppressor gene but whose family histories are not indicative of the Li-Fraumeni syndrome. The early detection of such mutations would be useful not only in treating these patients, but also in identifying family members who may be at high risk for the development of tumors.

Adolescent↗