1 D-Galactosamine (GalN) depletes UTP primarily in the liver, resulting in decreased RNA synthesis in hepatocytes. Co-injection of GalN and lipopolysaccharide (LPS) into mice produces fulminant hepatitis with severe hepatic congestion, resulting in rapid death. Although the underlying mechanism is uncertain, GalN enhances the sensitivity to tumour necrosis factor (TNF). Administration of uridine (a precursor of UTP) prior injection of either LPS itself or interleukin-1 (IL-1) reduces the lethality of GalN+LPS. The present study focused on the e ects of these agents on TNF production. 2 Intraperitoneal injection of GalN+LPS into mice greatly elevated serum TNF. Although large doses of LPS alone also greatly elevated serum TNF, LPS itself induced neither hepatic congestion nor rapid death. Administration of a macrophage depletor, liposomes encapsulated with dichloromethylene bisphosphonate, reduced both the TNF production and mortality induced by GalN+LPS. 3 Uridine, when injected 0.5 h after the injection of GalN+LPS, reduced the production of TNF. Prior injection of LPS, but not of IL-1, also reduced this TNF production. 4 Serum from LPS-injected mice reduced the TNF production induced by GalN+LPS, but it was less e ective at reducing the lethality. Its ability to reduce TNF production was abolished by heattreatment. 5 We hypothesize that a factor inhibiting TNF production by macrophages is produced by hepatocytes in response to LPS. Possibly, production of this hepatocyte-derived TNF-downregulator (TNF-DRh) may be: (i) inhibited by GalN, causing over-production of TNF by macrophages and (ii) stimulated by LPS-pretreatment (and restored by uridine), causing reduced TNF production.

Within a few minutes of an intravenous injection of a lipopolysaccharide (LPS) into mice, platelets accumulate, largely in the lung. At higher doses, LPS induces rapid shock (within 10 min), leading to death within 1 h. This type of shock differs from so-called endotoxin shock, in which shock signs and death occur several hours or more later. Here, we found that platelet depletion (by a monoclonal anti-platelet antibody) prevented LPS-induced rapid shock, but increased delayed lethality. In Japan, glycyrrhizin (GL), a compound isolated from licorice, is daily and slowly infused intravenously into chronic hepatitis C patients. A single bolus intravenous injection into mice of GL (200 mg/kg or less) shortly before (or simultaneously with) LPS injection reduced the pulmonary platelet accumulation and the severity of the rapid shock, and prevented death in both the early and later periods. GL itself, at 400 mg/kg, produced no detectable abnormalities in the appearance or activity of mice. Intraperitoneal injection of aspirin or dexamethasone had only marginal effects on LPS-induced platelet responses and lethality. These results suggest that platelets play important roles in the development of both the rapid and delayed types of shock induced by LPS. Although the mechanism by which GL suppresses platelet responses and delayed lethality remains to be clarified, GL might provide a strategy for alleviating the acute respiratory distress syndrome seen in sepsis. Our results may also support the proposal by Cinatl et al. [Cinatl J, Morgenstern B, Bauer G, Chandra P, Ravenau H, Doerr HW. Glycyrrhizin, an active component of liquorice roots, and replication of SARS-associated coronavirus. Lancet 2003; 361: 2045-6.] that GL may be an effective drug against severe acute respiratory syndrome.

ABSTRACT. We examined combination therapy with both lactoferrin (Lf) and antibiotics on clinical mastitis due to Staphylococcus aureus (S.aureus) on drying cows. The clinical symptoms of mastitic quarters were cured 81% of combination therapeutic quarters at 7 days post injection (dpi). Moreover, most of mammary gland secretions (MGSs) in combination therapeutic quarters were normal at 7 days after parturition. In the quarters with combination therapy, S.aureus counts, Lf concentrations and content rate of concanavalin A (Con A) low-affinity Lf decreased and were lower than in the quarters treated with Lf or antibiotics alone. The mRNA expression of tumor necrosis factor α (TNFα) of the quarters with combination therapy also decreased and was lower than that of the Lf or antibiotics treated. The mRNA expression of pro-inflammatory cytokines and chemokines in bovine mammary gland epithelial lined cells (BMEC) stimulated with Lf were lower than those of Con A low-affinity Lf stimulated BMEC. Moreover, Lf showed an inhibitory effect to the induction of pro-inflammatory cytokine mRNA expression when co-stimulated with Lf and Con A low-affinity Lf. Nuclear factor kappa B (NFκB) activation was also induced with Con A low-affinity Lf, and the inhibitory effects of Lf were also confirmed on BMEC co-stimulated with Lf and Con A low-affinity Lf. These results indicated that the efficacy of combination therapy with antibiotics and Lf caused antibacterial effect of antibiotics and inhibition of pro-inflammatory cytokine and chemokine production with Lf via the inhibition of NFκB activation.

ABSTRACT. We examined the effective diagnostic indicator using the concanavalin A (Con A) low-affinity lactoferrin (Lf) to mastitic drying cows. The concentrations of both Lf and Con A low-affinity Lf in mammary gland secretions (MGSs) were lower than normal MGSs at the early and middle dry periods and colostrums. On the other hand, the levels of Con A low-affinity Lf in MGSs increased following the appearance of mastitis symptoms, and decreased when the mastitic symptoms were cured. Moreover, IgG1 concentrations of colostrums decrease on the quarters where a high level of Con A low-affinity Lf was determined after the onset of dry period. These results suggest that this method could be used as a useful indicator to mastitic drying cows. KEY WORDS: dry period, lactoferrin, mastitis diagnosis.