A 10-year review of cannabis exposure in children under 3-years of age: do we need a more global approach?

Pediatricians working in an emergency environment are confronted with children admitted to emergency departments for intoxication on a daily basis. We carried out a retrospective cohort study of children admitted to a pediatric emergency department due to unintentional cannabis exposure over a 10-year period from 2004 to 2014. Twenty-nine children under the age of 3 were admitted with a positive cannabis urine test. Eighty-seven percent of intoxications occurred at the family home. Resin was the main form of ingested cannabis (69%). The mean age was 16.5 ± 5.2 months, and mean weight was 11.1 ± 2.1 Kg. Sixty percent of admissions occurred between 2012 and 2014. More severe presentations, based on Poisoning Severity Score, occurred over the past 2 years. Four children experienced seizures before admission. Ten children (34%) had a decreased level of consciousness (GCS <12) and were admitted to a pediatric intensive care unit for 12-24 h. All of them had ingested hashish (resin). The majority (70%) of children suffering from neurological impairment were admitted in the last year, of whom three required assisted ventilation. There were no cases with major outcomes and no deaths. Parents were not assessed regarding their cannabis consumption. CONCLUSION: This study supports the impression that accidental child poisonings with cannabis have been more serious than previously thought for 2 years. This observation may be explained by (1) the increased THC concentration in cannabis and (2) the widespread use in young adults, even after they become parents. Introducing an addiction team inside the PED could help to improve the care links with these parents. What is Known: • Cases of unintentional cannabis intoxication in children have been increasing for many years due to an increase of potency. What is New: • We highlight an increase in more severe presentations in children under the age of 3 occurring over the past 2 years, which will indicate the importance of assessing cannabis abuse in parents by a specialized addiction team.

Human delta-lactoferrin is a transcription factor that enhances Skp1 (S-phase kinase-associated protein) gene expression.

Delta-lactoferrin is a cytoplasmic lactoferrin isoform that can locate to the nucleus, provoking antiproliferative effects and cell cycle arrest in S phase. Using macroarrays, the expression of genes involved in the G(1)/S transition was examined. Among these, Skp1 showed 2-3-fold increased expression at both the mRNA and protein levels. Skp1 (S-phase kinase-associated protein) belongs to the Skp1/Cullin-1/F-box ubiquitin ligase complex responsible for the ubiquitination of cellular regulators leading to their proteolysis. Skp1 overexpression was also found after delta-lactoferrin transient transfection in other cell lines (HeLa, MDA-MB-231, HEK 293) at comparable levels. Analysis of the Skp1 promoter detected two sequences that were 90% identical to those previously known to interact with lactoferrin, the secretory isoform of delta-lactoferrin (GGCACTGTAC-S1(Skp1), located at - 1067 bp, and TAGAAGTCAA-S2(Skp1), at - 646 bp). Both gel shift and chromatin immunoprecipitation assays demonstrated that delta-lactoferrin interacts in vitro and in vivo specifically with these sequences. Reporter gene analysis confirmed that delta-lactoferrin recognizes both sequences within the Skp1 promoter, with a higher activity on S1(Skp1). Deletion of both sequences totally abolished delta-lactoferrin transcriptional activity, identifying them as delta-lactoferrin-responsive elements. Delta-lactoferrin enters the nucleus via a short bipartite RRSDTSLTWNSVKGKK(417-432) nuclear localization signal sequence, which was demonstrated to be functional using mutants. Our results show that delta-lactoferrin binds to the Skp1 promoter at two different sites, and that these interactions lead to its transcriptional activation. By increasing Skp1 gene expression, delta-lactoferrin may regulate cell cycle progression via control of the proteasomal degradation of S-phase actors.

Expression of delta-lactoferrin induces cell cycle arrest.

Delta-lactoferrin (deltaLf) mRNA is the product of alternative splicing of the Lf gene. It has been found in normal tissues and was reported to be absent from their malignant counterparts. Our recent investigations have shown that deltaLf expression is a good prognostic indicator in human breast cancer. However, deltaLf has up till now only been identified as a transcript, and in order to characterize the deltaLf protein and determine its function we have used a deltaLf cDNA construct to produce the protein in vitro and in vivo. A 73 kDa protein was immunoprecipitated from in vitro translation products and this molecular weight is in accordance with the use of the first in frame AUG start codon located in exon 2. We also produced a cell line expressing deltaLf under doxycycline induction. Using this model we have been able to show that deltaLf is mainly distributed in the cytoplasm. Its expression induces cell cycle arrest and inhibits cell proliferation. Our results suggest that deltaLf may play an important role in the regulation of normal cell growth.