Effect of coenzyme-A,NAD, alpha lipoic-acid and cocarboxylase on survival of rats with galactosamine-induced severe hepatitis

Summary Galactosamine, a selective hepatotoxin, produces in rats histologic alterations, which show the characteristics of severe human viral hepatitis. In the present study the efficacy of two different cofactor regimens (coenzyme A, NAD, alpha lipoic-acid, cocarboxylase) in rats with fulminant galactosamine hepatitis were tested. The results showed an improvement of the short-term survival with a short-term treatment and definitely better survival with a long-term regimen with cofactors.     

No supernovae associated with two long-duration gamma-ray bursts

It is now accepted that long-duration gamma-ray bursts (GRBs) are produced during the collapse of a massive star. The standard 'collapsar' model predicts that a broad-lined and luminous type Ic core-collapse supernova accompanies every long-duration GRB. This association has been confirmed in observations of several nearby GRBs. Here we report that GRB 060505 (ref. 10) and GRB 060614 (ref. 11) were not accompanied by supernova emission down to limits hundreds of times fainter than the archetypal supernova SN 1998bw that accompanied GRB 980425, and fainter than any type Ic supernova ever observed. Multi-band observations of the early afterglows, as well as spectroscopy of the host galaxies, exclude the possibility of significant dust obscuration and show that the bursts originated in actively star-forming regions. The absence of a supernova to such deep limits is qualitatively different from all previous nearby long-duration GRBs and suggests a new phenomenological type of massive stellar death.     

Observation of surface and bulk phase transitions in nematic liquid crystals

The behaviour of liquid crystal (LC) molecules near a surface is of both fundamental and technological interest: it gives rise to various surface phase-transition and wetting phenomena, and surface-induced ordering of the LC molecules is integral to the operation of LC displays. Here we report the observation of a pure isotropic-nematic (IN) surface phase transition-clearly separated from the bulk IN transition-in a nematic LC on a substrate. Differences in phase behaviour between surface and bulk are expected, but have hitherto proved difficult to distinguish, owing in part to the close proximity of their transition temperatures. We have overcome these difficulties by using a mixture of nematic LCs: small, surface-induced composition variations lead to complete separation of the surface and bulk transitions, which we then study independently as a function of substrate and applied magnetic field. We find the surface IN transition to be of first order on surfaces with a weak anchoring energy and continuous on surfaces with a strong anchoring. We show that the presence of high magnetic fields does not change the surface IN transition temperature, whereas the bulk IN transition temperature increases with field. We attribute this to the interaction energy between the surface and bulk phases, which is tuned by magnetic-field-induced order in the surface-wetting layer.     

The gene encoding phosphodiesterase 4D confers risk of ischemic stroke

We previously mapped susceptibility to stroke to chromosome 5q12. Here we finely mapped this locus and tested it for association with stroke. We found the strongest association in the gene encoding phosphodiesterase 4D (PDE4D), especially for carotid and cardiogenic stroke, the forms of stroke related to atherosclerosis. Notably, we found that haplotypes can be classified into three distinct groups: wild-type, at-risk and protective. We also observed a substantial disregulation of multiple PDE4D isoforms in affected individuals. We propose that PDE4D is involved in the pathogenesis of stroke, possibly through atherosclerosis, which is the primary pathological process underlying ischemic stroke.     

Conjugates of adenine 9-α-D-arabinofuranoside monophosphate (ara-AMP) with lactosaminated homologous albumin are not immunogenic in the mouse

Summary Conjugates of adenine-9--D-arabinofuranoside (ara-A) or of ara-A monophosphate (ara-AMP) with asialofetuin or with heterologous lactosaminated serum albumin (L-SA) are strong antibody inducers. But ara-AMP conjugates prepared with homologous L-SA are not immunogenic, at least in mice.Acknowledgments. This work was supported by Consiglio Nazionale delle Ricerche, Progetto finalizzato, Controllo crescita neoplasica, grant 800154596. Ara-AMP was a gift from Dr M. L. Black, Warner-Lambert Co (Ann Arbor, MI). The excellent technical assistance of Mr Goffredo Nanetti is gratefully acknowledged.