A false positive newborn screening result due to a complex allele carrying two frequent CF-causing variants

International audienceThe detection of two frequent CFTR disease-causing variations in the context of a newborn screening program (NBS) usually leads to the diagnosis of cystic fibrosis (CF) and a relevant genetic counseling in the family. In the present study, CF-causing variants p.Phe508del (F508del) and c.3140-26A>G (3272-26A>G) were identified on a neonate with positive ImmunoReactive Trypsinogen test by the Elucigene™ CF30 kit. The CF diagnosis initially suggested, despite three inconclusive Sweat Chloride Tests (SCT), was finally ruled out after the familial segregation study combined with a negative SCT. Haplotype studies, based on the comparison of 80 p.Phe508del haplotypes, suggested a probable de novo occurrence of c.3140-26A>G on the p.Phe508del ancestral allele in this family. This false positive case emphasizes the importance of SCT in the NBS strategy. Moreover, it raises the need for familial segregation studies in CF and in overall molecular diagnosis strategy of autosomal recessive diseases

A 4-weekly course of rituximab is safe and improves tumor control for patients with minimal residual disease persisting 3 months after autologous hematopoietic stem-cell transplantation: results of a prospective multicenter phase II study in patients with follicular lymphoma.

International audienceBACKGROUND: This study explored the efficacy and safety of rituximab as treatment of clinical or molecular residual disease after autologous stem-cell transplantation (ASCT) in follicular lymphoma (FL). PATIENTS AND METHODS: Forty patients with CD20+ FL and clinically (group A, n = 14) or clono-specific PCR-detectable (group B, n = 25) residual disease persisting 3 months after ASCT received rituximab 375 mg/m² once weekly for 4 weeks. RESULTS: Response rate at day 50 was 36% [90% confidence interval (CI) 15-61] in group A (World Health Organization criteria) and 52% (90% CI 34-70) in group B (conversion PCR-undetectable status to undetectable status). The best response rate was 71% [nine complete responses (CRs) and one partial response] in group A and 76% in group B. At 36 months, all 10 responses persisted in group A, whereas 46% of patients in group B still had PCR-undetectable disease. Furthermore, 68% of patients in group B were still in clinical CR. Rituximab after ASCT was safe with few grade 3-4 toxic effects (15% patients), mainly acute reactions and infections. CONCLUSION: Rituximab induced a high rate of durable CRs in patients with clinically detectable disease, as well as durable eradication of PCR-detectable disease in patients with FL after ASCT. Continued molecular responses assessed with a highly sensitive and clono-specific PCR technique were correlated with an excellent disease control

Thymol as an alternative to pesticides: persistence and effects of Apilife Var on the phototactic behavior of the honeybee Apis mellifera

International audienceThymol is a natural substance increasingly used as an alternative to pesticides in the fight against the Varroa destructor mite. Despite the effectiveness of this phenolic monoterpene against Varroa, few articles have covered the negative or side effects of thymol on bees. In a previous study, we have found an impairment of phototaxis in honeybees following application of sublethal doses of thymol—lower or equal to 100 ng/bee—under laboratory conditions. The present work shows the same behavioral effects on bees from hives treated with Apilife Var®, a veterinary drug containing 74 % thymol, with a decrease in phototactic behavior observed 1 day after treatment. Thus, thymol causes disruption of bee phototactic behavior both under laboratory conditions as well as in beehives. The bee exposure dose in treated hives was quantified using gas chromatography coupled to mass spectrometry (GC–MS), giving a median value of 4.3 μg per body 24 h after treatment, with 11 ng in the brain. The thymol level in 20 organic waxes from hives treated with Apilife Var® was also measured and showed that it persists in waxes (around 10 mg/kg) 1 year after treatment. Thus, in the light of (1) behavioral data obtained under laboratory conditions and in beehives, (2) the persistence of thymol in waxes, and (3) the high load on bees, it would appear important to study the long-term effects of thymol in beehives

Effect of a thymol application on olfactory memory and gene expression levels in the brain of the honeybee Apis mellifera

International audienceEssential oils are used by beekeepers to control the Varroa mites that infest honeybee colonies. So, bees can be exposed to thymol formulations in the hive. The effects of the monoterpenoid thymol were explored on olfactory memory and gene expression in the brain of the honeybee. In bees previously exposed to thymol (10 or 100 ng/bee), the specificity of the response to the conditioned stimulus (CS) was lost 24 h after learning. Besides, the octopamine receptor OA1 gene Amoa1 showed a significant decrease of expression 3 h after exposure with 10 or 100 ng/bee of thymol. With the same doses, expression of Rdl gene, coding for a GABA receptor subunit, was not significantly modified but the trpl gene was upregulated 1 and 24 h after exposure to thymol. These data indicated that the genes coding for the cellular targets of thymol could be rapidly regulated after exposure to this molecule. Memory and sensory processes should be investigated in bees after chronic exposure in the hive to thymol-based preparations