Precarious adolescence: Adolescent rickets and anterior sacral angulation in two Dutch skeletal collections from the 18th-19th centuries.

OBJECTIVE: This project aims to provide an objective approach to suggesting cases of adolescent rickets using the presence of anterior sacral angulation and interglobular dentine. MATERIALS: Sacra from 49 individuals from Hattem and 150 individuals from Middenbeemster, and second and third molars from five individuals from Hattem were analyzed. Both sites date to the 17th to 19th centuries. METHODS: The sacra were visually assessed for sacral angulation and measured to quantify anterior sacral angulation. The sampled molars were thin sectioned to look for the presence of interglobular dentine. RESULTS: Metric analysis determined that seven individuals had significantly anteriorly angled sacra. Three of the five individuals with sampled molars had interglobular dentine formed during adolescence. CONCLUSIONS: Adolescent rickets may be associated with anterior sacral angulation. SIGNIFICANCE: Anterior sacral angulation may help identify possible cases of adolescent rickets in archaeological human remains. LIMITATIONS: The small sample size for the molars prevented the identification of more individuals with interglobular dentine present during adolescence. Several individuals with visibly angled sacra were unmeasurable due to post-mortem damage and lacked molars. SUGGESTIONS FOR FURTHER RESEARCH: Research on a larger sample would allow us to understand better the association between anterior sacral angulation and adolescent rickets.

In a three-dimensional reconstructed human epidermis filaggrin-2 is essential for proper cornification.

Atopic dermatitis is a chronic inflammatory skin disease with defects in the epidermal barrier. In a cohort of African-American children, a FLG2 nonsense mutation has been associated with the disease. In the epidermis of European patients, the expression of filaggrin-2, the filaggrin-related protein encoded by FLG2, is decreased. To describe the function of filaggrin-2 and evaluate the impact of its deficiency, its expression was downregulated using lentivirus-mediated shRNA interference in a three-dimensional reconstructed human epidermis (RHE) model. This resulted in parakeratosis and a compact stratum corneum, presence of abnormal vesicles inside the corneocytes, increased pH and reduced amounts of free amino acids at the RHE surface, leading to increased sensitivity to UVB radiations. The expression of differentiation markers was slightly modified. However, we observed reduced proteolytic processing of corneodesmosin, hornerin and filaggrin in parallel with reduced amounts of caspase-14 and bleomycin hydrolase. Our data demonstrated that filaggrin-2 is important for a proper cornification and a functional stratum corneum. Its downregulation in atopic patients may be involved in the disease-associated epidermis impairment.

[Study of P50 in patients under continuous O2 inhalation and during chronic respiratory acidosis]. / Etude de la P50 chez les sujets sous O2 continu et en acidose respiratoire chronique

In vitro, the affinity of Hb for O2 depends on pH and capnia by the intermediate of the 2-3 DPG level, the concentration of which lowers in the case of acidosis and hypercapnia. Thus, an increase in the affinity results, but while Bohr's effect is immediate, on the contrary the 2-3 DPG effect is slow. Authors have verified the importance of this modification by studying the affinity of Hb for O2 thanks to the P50 technique in 15 normal non-smokers subjects and in 10 subjects with compensated or not respiratory acidosis but normally saturated thanks to continuous O2 administration.