Pleraplysillin-2, a further furanosesquiterpenoid from the spongePleraplysilla spinifera

Cellular and Molecular Life Sciences - Si riporta l'isolamento dalla spugnaPleraplysilla spinifera di un ulteriore furanosesquiterpenoide pleraplysillina-2 per il quale si dimostra la struttura 3.     

Naloxone selectively blocks dopamine response of Br-type neuron inHelix pomatia L.

Summary The present study demonstrates that the potent opiate antagonist, naloxone can selectively block the DA induced inhibition of the bursting activity pattern of the RPal or Br-type neuron. The dopamine inhibitory affect can also be blocked by haloperidol, a established dopamine receptor blocker.This work partially supported by a grant from the National Academy of Sciences and the Hungarian Academy of Sciences awarded to G.B.S. We also gratefully acknowledge thoughtful comments from Dr J. Salanki.     

Injection of adult neurospheres induces recovery in a chronic model of multiple sclerosis

Widespread demyelination and axonal loss are the pathological hallmarks of multiple sclerosis. The multifocal nature of this chronic inflammatory disease of the central nervous system complicates cellular therapy and puts emphasis on both the donor cell origin and the route of cell transplantation. We established syngenic adult neural stem cell cultures and injected them into an animal model of multiple sclerosis--experimental autoimmune encephalomyelitis (EAE) in the mouse--either intravenously or intracerebroventricularly. In both cases, significant numbers of donor cells entered into demyelinating areas of the central nervous system and differentiated into mature brain cells. Within these areas, oligodendrocyte progenitors markedly increased, with many of them being of donor origin and actively remyelinating axons. Furthermore, a significant reduction of astrogliosis and a marked decrease in the extent of demyelination and axonal loss were observed in transplanted animals. The functional impairment caused by EAE was almost abolished in transplanted mice, both clinically and neurophysiologically. Thus, adult neural precursor cells promote multifocal remyelination and functional recovery after intravenous or intrathecal injection in a chronic model of multiple sclerosis.     

Distribution of radioactivity after administration of3H-5-hydroxytryptamine by three different routes to the musselMytilus edulis

Summary Intracardiac injection gives proportionately higher and earlier peak concentration in tissues that specifically accumulates it, i.m. injection gives slower but longer lasting accumulations, and topical application to a ganglia essentially localizes the drug in that structure.We wish to thank Drs Hiripi and Nemcsok for the demonstration of the intracardiac technique. We also wish to thank Drs Haley and Ledeen for the use of the scintillation counter.     

Chemistry of mediterranean gorgonians. II. Pregna 4,20-dien-11α-ol-3-one acetate,a novel steroid from the gorgonianEunicella cavolini

Summary The compound titled1 has been isolated from the gorgonianE. cavolini and synthesized from 11-acetoxy-progesterone (3).This work has been carried out in the frame of the Progetto Finalizzato per l'Oceanografia e i Fondi marini, C.N.R., Roma. Acknowledgments. We are grateful to the Zoological Station (Naples) for the collection of Gorgonians. Thanks are also due to Mr G. Scognamiglio, for technical assistance and to Mr C. Di Pinto, for NMR-experiments.     

CFD simulation of fluidization quality in the three-dimensional fluidized bed

Multiphase computational fluid dynamics (CFD) has become an alternative method to experimental investigation on predicting the fluid dynamics in gas-solid fluidized beds. The model of Brandani and Zhang, which contains additional terms in both the gas- and solid-phase momentum equations, is employed to explore homogenous fluidization of Geldart type A particles and bubbling fluidization of Geldart type B particles in three-dimensional gas-fluidized beds. In this model, only a correlation for drag force is necessary to close the governing equations. Two kinds of solids, i.e., fine alumina powder (d_p=60 μm and ρ_p=1500 kg/m³) and sand (d_p=610 μm and ρ_p=2500 kg/m³), are numerically simulated in a rectangular duct of 0.2 m (long) ×0.2 m (wide) ×0.5 m (high). The results show good agreement with the classic theory of Geldart.     

Glycogen synthase kinase-3β regulates fractalkine production by altering its trafficking from Golgi to plasma membrane: implications for Alzheimer’s disease

Glycogen synthase kinase-3β (GSK-3β) is a serine-threonine kinase implicated in multiple processes and signaling pathways. Its dysregulation is associated with different pathological conditions including Alzheimer’s disease (AD). Here we demonstrate how changes in GSK-3β activity and/or levels regulate the production and subsequent secretion of fractalkine, a chemokine involved in the immune response that has been linked to AD and to other different neurological disorders. Treatment of primary cultured neurons with GSK-3β inhibitors such as lithium and AR-A014418 decreased full-length fractalkine in total cell extracts. Opposite effects were observed after neuron transduction with a lentiviral vector overexpressing the kinase. Biotinylation assays showed that those changes mainly affect the plasma membrane-associated form of the protein, an observation that positively correlates with changes in the levels of its soluble form. These effects were confirmed in lithium-treated wild type (wt) mice and in GSK-3β transgenic animals, as well as in brain samples from AD patients, evident as age-dependent (animals) or Braak stage dependent changes (humans) in both the membrane-bound and the soluble forms of the protein. Further immunohistochemical analyses demonstrated how GSK-3β exerts these effects by affecting the trafficking of the chemokine from the Golgi to the plasma membrane, in different and opposite ways when the levels/activity of the kinase are increased or decreased. This work provides for the first time a mechanism linking GSK-3β and fractalkine both in vitro and in vivo, with important implications for neurological disorders and especially for AD, in which levels of this chemokine might be useful as a diagnostic tool.