Lethal osteogenesis imperfecta. Definition and heterogeneity

The lethal form of osteogenesis imperfecta must be more clearly defined than it is. Early death of the child is not a sufficient criteria since it is observed in other forms compatible with survival. The authors therefore insist on the innumerable fractures of the ribs giving the particular aspect described as "bamboo ribs". These are observed in practically all cases. Heterogeneity however is undoubtful and an X-ray film is reproduced showing thin ribs without fractures in another exceptional lethal form. Genetic and very recent biochemical investigations suggest a new heterogeneity of the lethal form, even well defined clinically and radiologically. Contrary to earlier and frequent statements, it results most often from a dominant mutation, while recessive inheritance is much rarer, therefore the overall risk of recurrence much below 25%.     

Fine structure and functional role of the coverings of the eggs inMesostoma ehrenbergii (Focke) (Turbellaria,Neorhabdocoela)

Summary European populations of the turbellarianMesostoma ehrenbergii can produce two types of eggs according to a seasonal cycle. Subitaneous eggs (S eggs) are produced throughout the warm season and develop rapidly inside the parental uteri. They are meant to ensure a fast increase in the number of worms. Dormant eggs (D eggs) are produced during the warm season and are usually deposited in water at the death of the parent. They can hatch at the beginning of the next warm season and are, therefore, meant to ensure the survival of the population throughout the cold season, when adult worms are no longer present.S eggs are bounded by a thin, translucent covering which has a loose structure and is mainly proteinaceous in composition. These characteristics account for the functional role played by the S egg covering during embryonic development. The covering has, in fact, to be permeable to parental nutrients, and to keep pace, by stretching, with the enlargement of the embryo. By contrast, D eggs are bounded by a thick shell, presumably composed of a sclerotin, the precursors of which (polyphenols) are synthesized together with yolk in the vitelline cells. The shell has a smooth surface devoid of pores and has the function of isolating the developing D egg from the external environment.Supported by a grant from the Consiglio Nazionale della RicercheThe authors wish to thank Dr. P. Roach for his help in translating the paper     

Is Carrying Feathers a Sexually Selected Trait in House Sparrows?

Males in several avian groups carry specialised materials as part of their courtship display. Females may vary their investment in reproduction in relation to their mates' attractiveness. The house sparrow (Passer domesticus) population on Dassen Island, South Africa, builds domed nests in the branches of trees. These nests are more or less spherical structures with a deep cup lined largely with feathers. When males collect feathers, they call to females and display the feather before it is added to the nest. We examined whether carrying feathers provides females with an index of male quality, which correlates with their subsequent investment in parental care. Additionally, we studied the potential importance of feathers in nest insulation. Feathers were collected mainly by males. Males also brought larger feathers, and deposited more feathers in nests, than females. Number of trips with feathers – which increased after feathers were experimentally removed from nests – and number of feathers brought varied among males. Volume of feathers influenced females' investment in reproduction and positively correlated with clutch size and chick feeding rates. We found more feathers during incubation and immediately after chicks hatched, when nest heat requirements peak. Furthermore, number of trips with feathers and number and size of feathers were greater during incubation. Our results suggest that this feather‐carrying behaviour by male house sparrows influences maternal reproduction investment and could be a kind of parental care per se by supplementing nest insulation.     

Identification of a Functional Homolog of the Yeast Copper Homeostasis Gene ATX1 from Arabidopsis

A cDNA clone encoding a homolog of the yeast (Saccharomyces cerevisiae) gene Anti-oxidant 1 (ATX1) has been identified from Arabidopsis. This gene, referred to as Copper CHaperone (CCH), encodes a protein that is 36% identical to the amino acid sequence of ATX1 and has a 48-amino acid extension at the C-terminal end, which is absent from ATX1 homologs identified in animals. ATX1-deficient yeast (atx1) displayed a loss of high-affinity iron uptake. Expression of CCH in the atx1 strain restored high-affinity iron uptake, demonstrating that CCH is a functional homolog of ATX1. When overexpressed in yeast lacking the superoxide dismutase gene SOD1, both ATX1 and CCH protected the cell from the reactive oxygen toxicity that results from superoxide dismutase deficiency. CCH was unable to rescue the sod1 phenotype in the absence of copper, indicating that CCH function is copper dependent. In Arabidopsis CCH mRNA is present in the root, leaf, and inflorescence and is up-regulated 7-fold in leaves undergoing senescence. In plants treated with 800 nL/L ozone for 30 min, CCH mRNA levels increased by 30%. In excised leaves and whole plants treated with high levels of exogenous CuSO₄, CCH mRNA levels decreased, indicating that CCH is regulated differently than characterized metallothionein proteins in Arabidopsis.     

Adrenomedullin increases fibroblast-like synoviocyte adhesion to extracellular matrix proteins by upregulating integrin activation

Introduction  

Rheumatoid arthritis (RA) is characterized by bone and cartilage invasion by fibroblast-like synoviocytes (FLSs). Adrenomedullin, a peptide with anabolic and antiapoptotic properties, is secreted by rheumatoid FLSs. Adrenomedullin also increases the expression of adhesion molecules in endothelial cells and keratinocytes. Here, we investigated whether adrenomedullin mediated FLS adhesion to extracellular matrix (ECM) proteins.     

Synthesis of C5-tetrazole derivatives of 2-amino-adipic acid displaying NMDA glutamate receptor antagonism

Five derivatives of 2-amino-adipic acid bearing a tetrazole-substituted in C5 position were synthesized. These compounds displayed selective antagonism towards N-methyl-d-aspartate (NMDA) receptors compared with AMPA receptors, and they were devoid of any neurotoxicity. Among these five analogues, one exhibited a higher affinity for synaptic NMDA responses than the other four. Therefore, C5 tetrazole-substituted of 2-amino-adipic acid represent an interesting series of new NMDA receptor antagonists. This approach may be considered as a new strategy to develop ligands specifically targeted to synaptic or extra-synaptic NMDA receptors.