RESUMO
A mesogenic metallofoldamer [(1R,R-Ni)2Pd] exhibits thermotropic columnar liquid crystalline properties. The metallofoldamer was prepared from two homochiral crescent-shaped precursors having ß-diketonate ligands (1R,R-Ni) through bridging by metal complexation; it exhibited a single helicity owing to the overlapping of both ends. The precursor and metallofoldamer formed similar hexagonal columnar phases. The helical metallofoldamer exhibited the hexagonal columnar phase at the higher temperature range owing to its rigid helical mesogenic structure.
RESUMO
Ceramide (CER), an important component of the extracellular lamellar lipids in the stratum corneum (SC), plays a critical role in maintaining the cutaneous barrier function. This study aimed to determine whether the quantity of free extractable SC CERs in dogs was affected by the age, sex, or breed. Fifty-eight dogs from the breeds Shiba Inu, beagle, miniature dachshund, shih tzu, and golden retriever, without any history of skin problems, were enrolled in this study. Lipid extracts from the SC were subjected to high-performance thin-layer chromatography to quantify the free extractable CERs. There were weak negative correlations between the age and the amount of free extractable CERs, CER [NP] (non-hydroxy fatty acids linked to phytosphingosines), CER [AS/NH] (α-hydroxy fatty acids linked to sphingosines/non-hydroxy fatty acids linked to 6-hydroxysphingosines), and CER [AP] (α-hydroxy fatty acids and phytosphingosines). There were no significant sex- or breed-related differences in the amounts of free extractable SC CERs in the dogs. These findings imply that aging causes a decline in the amount of free extractable SC CERs in dogs, similar to that observed in humans. The sex or breed of the dogs investigated in this study did not influence the amount of free extractable SC CERs.
Assuntos
Ceramidas , Epiderme , Animais , Cães , PeleRESUMO
Ceramides (CERs) in the stratum corneum (SC) are thought to play a key role in cutaneous barrier function. It has been reported that human SC contains 11 free CER classes and that their profiles are altered in humans with atopic dermatitis (AD). Although decreased proportions of free CERs or quantities of protein-bound CERs in the SC have been reported in dogs with AD, the overall profile of CERs in the canine SC has not been fully elucidated. The aim of this study was thus to investigate the profile of free CERs in the canine SC and to identify alterations in the CER profiles in dogs with AD. Normal-phase liquid chromatography-electrospray ionization-mass spectrometry indicated 11 clusters of peaks for free CER classes, similar to those recognized in the human SC. The fractions of free SC CER in dogs with AD and in breed- and age-matched healthy dogs were quantitatively compared using high-performance thin-layer chromatography. CER[EOS], CER[EOP] and CER[NP], which are known to be decreased in the skin of humans with AD, were also decreased in the skin of dogs with AD. These findings highlight canine AD as a spontaneous animal model for investigating the disruption of CER-associated cutaneous barrier functions in the corresponding human disease.
