A review of the ecology, palaeontology and distribution of atlantid heteropods (Caenogastropoda: Pterotracheoidea: Atlantidae)

Fewer than 1% of marine gastropod species live a holoplanktic life. Of these, the shelled heteropods of the family Atlantidae are among the most poorly understood. The atlantids potentially make up an important part of the ocean zooplankton, composing up to 69% of shelled holoplanktic gastropods in the Late Pleistocene to Recent fossil record. They are also likely to be at high risk from current and future global changes, including anthropogenic ocean acidification. However, due to their small size (<12 mm), difficulty of sampling and complicated morphology, we still lack key information about atlantid taxonomy and ecology. This makes it difficult to understand how important they are in the ocean foodweb and how they will be affected by environmental change. Although many studies have been carried out on the atlantids, these have generally been broad and unconnected. Here, we draw together this previous research, summarizing what is currently known about atlantid taxonomy, palaeontology, ecology and biogeography, and aiming to provide a foundation for future research on this group. The data indicate complex behaviours involving seasonal and vertical migration, and demonstrate extended geographical ranges, with implications for understanding the role of atlantids in the ocean foodweb and their sensitivity to environmental changes. This review highlights the urgent need for further taxonomic research on the atlantids, including molecular analysis, and for improved sampling techniques

Inhibitory effect of nitric oxide on the replication of a murine retrovirus in vitro and in vivo

Nitric oxide (NO) exerts microbicidal effects on a broad spectrum of pathogens, including viruses, but its antiretrovirus properties have not yet been described. The purpose of this study was to determine whether NO inhibits murine Friend leukemia virus (FV) replication in vitro and to what extent NO may play a role in defenses against FV infection in mice. Three NO-generating compounds were studied: 3-morpholino-sydononimine (SIN-1), sodium nitroprusside (SNP), and S-nitroso-N-acetylpenicillamine (SNAP). The effects of these three compounds were compared with those of their controls (SIN-1C, potassium ferricyanide, and N-acetylpenicillamine, respectively), which do not generate NO and with that of sodium nitrite (NaNO2). SIN-1, SNP, and SNAP inhibited FV replication in dunni cells in a concentration-dependent manner. In contrast, no significant inhibitory effect was observed with the three controls or NaNO2. Furthermore, the addition of superoxide dismutase did not alter the inhibitory effect of SIN-1, which is also known to generate superoxide anions. No dunni cell toxicity was observed in the range of concentrations tested. We also assessed the effect of NO produced by activated macrophages on FV replication. Macrophages activated by gamma interferon and lipopolysaccharide inhibited FV replication in a concentration-dependent manner. This inhibition was due in part to NO production, since it was reversed by NG-monomethyl L-arginine, a competitive inhibitor of NO synthase. In vivo administration of NG-nitro-L-arginine methyl ester, a competitive inhibitor of NO synthase, significantly increased the viral load in spleen cells of FV-infected mice. These results suggested that NO may play a role in defenses against the murine Friend leukemia retrovirus.</jats:p

Ciprofloxacin treatment <i>in vivo</i> increases the <i>ex vivo</i> capacity of lipopolysaccharide-stimulated human monocytes to produce IL-1, IL-6 and tumour necrosis factor-alpha

SUMMARY Because in vitro treatment with quinolones, at pharmacological concentrations, modifies lipopolysac-charide (LPS) induced production of cytokines by monocytes, we studied the effect of orally administered ciprofloxacin (25 mg/kg) on the capacity of peripheral blood monocyles of healthy volunteers to produce tumour necrosis factor-alpha (TNF-α), IL-1 activity, IL-1 a, IL-1β and IL-6 ex vivoin response to endotoxin stimulation. After 7 days of ciprofloxacin, the extracellular and cellular production of TNF-α, the cellular production of IL-1 activity, the extracellular and cellular production of IL-1α, and the cellular production of IL-6 increased significantly. Seven days after the end of the treatment, values returned to basal levels or even lower. To our knowledge, this is the first demonstration that ciprofloxacin can modulate in vivo the capacity of human monocytes to react to an inflammatory stimulus such as endotoxin.</jats:p

Absence of involvement of nitric oxide in LP-BM5-induced immunodeficiency syndrome

International audienceTo examine the role of nitric oxide (NO) in murine AIDS (MAIDS) pathogenesis, we determined NO production and inducible NOS (iNOS) mRNA expression in the macrophages of LP-BM5-infected mice, together with the in vivo effects of L-NAME, a competitive inhibitor of NO synthase. LP-BM5 infection induced neither spontaneous nitrite production nor iNOS mRNA expression. No differences in IFN gamma + LPS-induced nitrite production or iNOS mRNA expression were observed in macrophages, from non-infected or infected mice. Spleen weight, ecotropic MuLV replication, the blood lymphocyte phenotype and proliferative response of splenocytes were not modified by L-NAME. LP-BM5 infection did not increase macrophage NO production and NO production did not appear to protect against LP-BM5-induced immunodeficiency