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Biomedical subjects

Claire Berger

Publications and source records attributed to Claire Berger.

8 recordsLinked to original sources

Results of a phase II trial testing interferon-alpha 2b and cytarabine in children and adolescents with chronic myelogenous leukemia.

BACKGROUND: Chronic myelogenous leukemia (CML) is a rare disease in children and only few data are available concerning the results of interferon based therapy in this age group. Before the imatinib mesylate era, a prospective phase II trial was conducted to assess the efficacy and tolerance of a combination of interferon-alpha 2b (IFN) and cytarabine in children with CML in first chronic phase without a suitable HLA-identical donor. PROCEDURE: Fourteen consecutive children were recruited from 12 pediatric centers. Children received daily IFN (5 million U/m2) and subcutaneous cytarabine (20 mg/m2) for 10 days every month. RESULTS: The median duration of follow-up is 13 months (range 2-32 months). Seven children achieved a complete hematologic response after a median time of treatment of 3 months (range 1 week-4 months). Three children were not evaluable for the cytogenetic response. A major cytogenetic response was achieved in seven patients (including complete cytogenetic response in two patient) within 12 months. The median time to major cytogenetic response was 7 months (range 3-12 months). Thirteen patients discontinued the treatment protocol after a median time of 11 months. Probability of progression free survival at 11 months was 83% (95% CI, 61%-100%). Grade 3 and 4 toxicity was observed in eight patients. The most frequently reported drug-related events were fever, mucositis, neutropenia, and thrombocytopenia. CONCLUSIONS: The combination of IFN and cytarabine provides hematologic and cytogenetic responses in children and adolescents with CML. In the imatinib mesylate era, the role of this combination as second line therapy in children with CML remains to be determined.

Adolescent↗

Electronic confinement and coherence in patterned epitaxial graphene.

Ultrathin epitaxial graphite was grown on single-crystal silicon carbide by vacuum graphitization. The material can be patterned using standard nanolithography methods. The transport properties, which are closely related to those of carbon nanotubes, are dominated by the single epitaxial graphene layer at the silicon carbide interface and reveal the Dirac nature of the charge carriers. Patterned structures show quantum confinement of electrons and phase coherence lengths beyond 1 micrometer at 4 kelvin, with mobilities exceeding 2.5 square meters per volt-second. All-graphene electronically coherent devices and device architectures are envisaged.

Journal Article↗

High-risk pregnancies in Diamond-Blackfan anemia: a survey of 64 pregnancies from the French and German registries.

We reviewed 64 pregnancies in 26 women with Diamond-Blackfan anemia (DBA) included in the French and German DBA registries. Complications were seen in 42 pregnancies (66%) and included abortion, pre-eclampsia, in utero fetal death, intrauterine growth retardation, retroplacental hematoma, pre-term delivery and fetal malformations. Of the 34 children (53%) born alive, 13 had DBA. No correlations were found between pregnancy outcome and features of either maternal or child DBA. Pregnancies in DBA-affected women are at high risk, especially for complications likely to be of vascular-placental origin. Careful monitoring with prevention of severe anemia and early introduction of aspirin is suggested.

Anemia↗

Characterisation of 96 mutations in 128 unrelated severe haemophilia A patients from France. Description of 62 novel mutations.

Direct sequencing of the coding region of factor VIII (F8) gene was used to determine the mutations responsible for severe haemophilia A (FVIII<1%) in 128 unrelated haemophiliacs A, negative for intron 22 and intron 1 inversions. A mutation was found in 122/128 patients (95%). Ninety-six distinct mutations were identified in this cohort, 62 of these are novel. They consisted of deletions (7 large and 24 small deletions), insertions (n = 9), associations of insertion/deletion (n = 2), association of deletion/substitution (n = 1), and single nucleotide substitutions (53 point mutations consisting of 31 missense, 20 nonsense, and 2 splicing mutations). Twenty-two patients had developed inhibitors, and among this subgroup 3 large deletions, 6 frameshift, 9 nonsense and 4 missense mutations were detected. For 6 patients, among which one developed an anti-FVIII inhibitor, no mutations were detected in the coding and splicing regions of factor VIII gene. Different approaches of molecular modelling were performed in addition to familial linkage analysis to determine the pathophysiological responsibility of these novel missense mutations.

Blood Coagulation Tests↗

Liquid carbon, carbon-glass beads, and the crystallization of carbon nanotubes.

The formation of carbon nanotubes in a pure carbon arc in a helium atmosphere is found to involve liquid carbon. Electron microscopy shows a viscous liquid-like amorphous carbon layer covering the surfaces of nanotube-containing millimeter-sized columnar structures from which the cathode deposit is composed. Regularly spaced, submicrometer-sized spherical beads of amorphous carbon are often found on the nanotubes at the surfaces of these columns. Apparently, at the anode, liquid-carbon drops form, which acquire a carbon-glass surface due to rapid evaporative cooling. Nanotubes crystallize inside the supercooled, glass-coated liquid-carbon drops. The carbon-glass layer ultimately coats and beads on the nanotubes near the surface.

Journal Article↗

Cancer incidence among children in France, 1990-1999.

BACKGROUND: Cancer is the second most important cause of death for children aged less than 15 years in France, unintentional injuries being the leading cause. The aim of the present study was to estimate the incidence of childhood cancer from six Childhood Cancer Registries covering 32% of France. PROCEDURE: Incident cancer cases diagnosed between 1990 and 1999 in children (0-14 years) resident in the administrative areas covered by each Registry were included. Annual age-standardized rates (ASRs) were adjusted by the world population. The estimated annual percent change (EAPC) was used to measure trend towards changes in the annual age-standardized incidence rate. RESULTS: With 4234 registered cases, the ASRs per million children were 137.5 for all cancers combined, 42.3 for leukemia, 29.1 for central-nervous-system tumors, 15.6 for lymphomas, 14.1 for sympathetic-nervous-system tumors, and 9.1 for renal tumors. The ASR of all cancers combined was slightly higher in males (145.8 per million children) than in females (128.7 per million children) with an M/F ratio of 1.2. No significant incidence trend was observed, with an EAPC of +0.2% [IC 95% (-2.5; +3.0); P = 0.89]. CONCLUSIONS: The estimated incidence rates are similar to those reported in previous studies in European and North American countries. These results will contribute to the development of National Registration of Childhood Cancer in France and support the national research program on childhood cancer.

Adolescent↗

Ballistic conduction in multiwalled carbon nanotubes.

The electrical transport in multiwalled carbon nanotubes is shown to be ballistic at room temperature with mean free paths on the order of tens of microns. The measurements are performed both in air and in the transmission electron microscope by contacting the free end of a nanotube pointing out of a fiber to a liquid metal and measuring the dependence of the nanotube resistance between the contacts. For a specific representative nanotube the resistance per unit length is found to be Rt = 31 +/- 61 omega/micron and the contact resistance with the liquid metal, Rc = 165 +/- 55 omega microns, corresponding to a mean free path l = 200 microns. Current-to-voltage characteristics are in accord with the electronic structure. The nanotubes survive high currents (up to 1 mA, i.e., current density on the order of 10(9) A/cm2). In situ electron microscopy shows that a relatively large fraction of the nanotubes do not conduct (even at high bias), consistent with the existence of semiconducting nanotubes. Discrepancies with other measurements are most likely due to damage caused to the outer layer(s) of the nanotubes during processing. The measured mean free path of clean, undamaged arc-produced multiwalled carbon nanotubes is several orders of magnitude greater than that for metals, making this perhaps the most significant property of carbon nanotubes.

Electric Conductivity↗