ABSTRACT
Extracellular matrix components can influence cell behaviour by modulating a wide variety of events. In particular, the glycosaminoglycan hyaluronan is involved in many processes of the normal and pathological adult cells and it is essential for embryonic development. Two main HA receptors have been characterized in vertebrate developing embryos: CD44 and RHAMM. These receptors display completely different characteristics apart from their ability to bind hyaluronan. RHAMM is still the most mysterious hyaluronan receptor as it can act as cell surface receptor but it can also be localized in the cytoplasm or in the cell nucleus, displaying both hyaluronan dependent and independent functions. In particular, the role of RHAMM during embryogenesis is still largely unclear. We reported a detailed gene expression analysis of RHAMM during Xenopus laevis development comparing its mRNA distribution with that of the hyaluronan synthases and CD44 genes, in order to provide a first insight into the possible role of RHAMM during vertebrate embryogenesis. Our findings point out that RHAMM mRNA displays a specific distribution in proliferating regions of the developing neural tube and retina where synthesis of hyaluronan is not detected. On the contrary, RHAMM expression correlates with the expression of hyaluronan synthase-1 and hyaluronan-receptor CD44 gene expression in migrating cranial neural crest. These results suggest that during the central nervous system development RHAMM could be involved in cell proliferation and migration processes both in a hyaluronan independent and dependent manner.
Subject(s)
Hyaluronan Receptors/genetics , Microtubule-Associated Proteins/genetics , Animals , Cell Movement/genetics , Cell Proliferation , Central Nervous System/embryology , Central Nervous System/metabolism , Gene Expression Regulation, Developmental , Glucuronosyltransferase/biosynthesis , Glucuronosyltransferase/genetics , Hyaluronan Receptors/biosynthesis , Hyaluronan Synthases , Microtubule-Associated Proteins/biosynthesis , Neural Tube/metabolism , RNA, Messenger/metabolism , Retina/embryology , Retina/metabolism , Xenopus Proteins , Xenopus laevis/embryologyABSTRACT
The thymus of 18-day-old normal-chick embryos, partially decerebrated chick embryos, and partially decerebrated embryos bearing hypophyseal allografts were analysed by light and transmission electron microscopy. The hypophyseal influence on the cytological differentiation of epithelial components has been studied. The thymus of partially decerebrated embryos showed a delayed differentiation of some types of epithelial cells and a marked decrease in number of lymphoid cells. Partially decerebrated embryos with hypophyseal implants showed a consistent recovery in the degree of differentiation of epithelial components. These findings indicate the influence of the hypophysis in establishing a correct environment for stromal cell differentiation.
Subject(s)
Decerebrate State/physiopathology , Pituitary Gland/transplantation , Thymus Gland/cytology , Thymus Gland/embryology , Animals , Cell Differentiation/physiology , Chick Embryo , Epithelial Cells , Microscopy, Electron , Stromal Cells/cytology , Thymus Gland/ultrastructure , Transplantation, HomologousSubject(s)
Poisoning/epidemiology , Adolescent , Age Factors , Child , Child, Preschool , Female , Humans , Infant , Infant, Newborn , Italy , Male , Poisoning/etiology , Poisoning/prevention & control , Prospective StudiesSubject(s)
Diagnosis-Related Groups , Severity of Illness Index , Wounds and Injuries/complications , Adolescent , Child , Female , Humans , Italy , Male , Prognosis , Time Factors , Wound HealingSubject(s)
Alcohol Drinking , Adolescent , Age Factors , Alcoholic Intoxication/epidemiology , Child , Child, Preschool , Female , Humans , Infant , Infant, Newborn , Italy , MaleABSTRACT
Outpatient treatment of burns and scalds has been evaluated at the Paediatric Emergency Unit of the Children's Hospital in Trieste. 183 children aged 0-15 years were treated by occlusive topical medication; in all cases control after three and twelve months was performed. No toxic symptomatology due to topical medication was observed. In four children local infection was resolved by topical aminoglycosides; in other four cases general antibiotics had to be administered because of isolate fever. Keloids resulted in 6 cases, 5 of them in the group of 32 children in which base treatment had to be integrated with other topical therapy because of early complications.
Subject(s)
Ambulatory Care , Burns/drug therapy , Adolescent , Burns/complications , Child , Child, Preschool , Female , Humans , Infant , Infant, Newborn , Male , Prospective StudiesSubject(s)
Accidents , Accidents/economics , Adolescent , Child , Child, Preschool , Female , Humans , Italy , Male , Sex Factors , Time FactorsSubject(s)
Accidents , Probability , Risk , Adolescent , Age Factors , Bites and Stings/pathology , Child , Child, Preschool , Female , Humans , Infant , Infant, Newborn , Male , Wounds and Injuries/pathologyABSTRACT
Six cases of Cortical Hyperostosis (C.H.) are presented. The clinical and laboratory features of the disease seem to be related to age at onset. In fact, our cases with a later onset (after the first year of life) are characterized by: a) a longer duration of the disease and a particularly high frequency of relapses; b) the absence of any sign of mandibular involvement; c) the presence of eosinophilia (700-1300/mm3). In two out of three cases having a later onset clinical and laboratory data suggest the hypotesis of a immunoallergic pathogenesis and particularly of cow's milk allergy. A review of the literature appears to confirm the differences between early and late onset forms of C.H. as for as the sites of skeletal involvement and the whole clinical course are concerned.
