Toxicity and biodegradability of imidazolium ionic liquids.

Several bioassays have been carried out to analyze the toxicity and biodegradability of several imidazolium ionic liquids (ILs) in aqueous phase. The synthetized compounds consist of an imidazolium cation with two alkyl substituents in positions 3 (R1) and 1 (R2) and a counter-ion. The alkyl substituent R1 has been fixed as a methyl group and the effect of the alkyl chain length (C1-C8) of the other substituent (R2) has been tested. Moreover, the influence of diverse counter-ions A- (Cl-, PF6, XSO4-) has been analyzed. Acute toxicity and EC50 values of each compound in the aqueous solution have been determined by using the Microtox standard procedure. Biodegradability of IL has been determined by measuring BOD5 of aqueous samples containing IL and/or D-glucose and the IL residual content and/or d-glucose concentration after this assay. The viability of the microorganisms used in the BOD5 has been related to the ATP in the samples, measured by a bioluminescence assay. All the ILs tested were not biodegradable in the considered conditions. Besides, it was found that the shorter the chain length of side chain R2, the lower the toxic effect is. On the contrary, the anion has a little effect on the IL toxicity.

Lipo prostaglandin E1 reduces the production of CXC chemokines in endotoxin-induced rat liver injury.

The present study attempted to assess the effect of prostaglandin E1 (PGE1) incorporated into lipid microspheres (Lipo PGE1) on chemokine production in endotoxin-induced rat liver injury. Male Wistar rats weighing 200-250 g were injected with 2 mg lipopolysaccharide (LPS) per kg intravenously. Lipo PGE1 was administered simultaneously at various concentrations (0.002, 0.02, 0.2, 2 µg/kg) in the tail vein. Blood samples and liver specimens were taken from the rats at 1, 3, 8, 12 and 24 h after injection with LPS alone or with LPS and Lipo PGE1. Serum macrophage inflammatory protein-2 (MIP-2) and cytokine-induced neutrophil chemoattractant (CINC) levels were measured by the enzyme-linked immunosorbant assay using the corresponding antibodies. Liver specimens were fixed, and the number of neutrophils that had infiltrated each liver section was determined under a microscope. Serum alanine aminotransferase (ALT) levels were significantly lower in the rats injected with LPS and Lipo PGE1 compared with those in the rats injected with LPS alone, and this difference was expressed in a PGE1 dose-dependent manner. Serum MIP-2 levels were significantly lower at 3 h (141.4+/-95.5 pg/ml) and 8 h (44.9+/-44.7 pg/ml) after injection with LPS and Lipo-PGE1 (2 µg/kg) than at the same times after injection with LPS alone (342.9+/-35.9 and 358.3+/-23.4 pg/ml, respectively). Similarly, serum CINC levels were significantly lower at 8 h (482.7+/-156.0 ng/ml) after injection with LPS and Lipo-PGE1 (2 µg/kg) than at the same time after injection LPS alone (723.3+/-29.0 ng/ml). No significant differences were observed at any time between serum tumor necrosis factor-alpha (TNF-alpha) levels in rats injected with LPS alone and in rats injected with LPS and Lipo-PGE1 (2 µg/kg). The number of neutrophils that had infiltrated the liver was significantly lower at 8 h after injection with LPS and Lipo PGE1 than at the same time after injection with LPS alone. This difference was expressed in a Lipo PGE1 dose-dependent manner. In conclusion, Lipo PGE1 reduces liver injury and serum levels of MIP-2 and CINC, but not TNF-alpha, in rats injected with LPS and also reduces the number of neutrophils that infiltrate in the liver.

An autopsy case of Wegener's granulomatosis with pachymeningitis.

A 61-year-old woman presented with high fever, headache and left facial palsy with diplopia. Histopathological examination of the biopsied specimens taken from nasal mucosa and kidney revealed a granulomatous angiitis with giant cell infiltration. Ga-DTPA-enhanced magnetic resonance imaging (MRI) revealed a thickening of dura mater in the middle cranial fossa and tentorium cerebelli. The observed left facial and occulomotor palsy was considered to be caused by pachymeningitis associated with Wegener's granulomatosis (WG). Cyclophosphamide combined with prednisolone effectively improved the symptoms. However, the patient died of acute interstitial pneumonitis, presumably caused by cyclophosphamide. The pathohistology obtained in the autopsy revealed a fibrous thickening of the dura mater in the left meningen with a segmental scarring of the arteries and a necrotizing arteritis in the kidney.

Enhanced interleukin-8 production by cultured Chang liver cells subjected to ethanol exposure and subsequent stimulation with tumor necrosis factor-alpha.

We investigated the production of interleukin-8 (IL-8) and chemotactic activity released from Chang liver cells subjected to long-term treatment with ethanol (Et) and subsequent stimulation with tumor necrosis factor-alpha (TNF-alpha). Chang liver cells were cultured in the presence of 5, 50 or 100 mmol/l Et for 4 weeks and then treated with recombinant TNF-alpha (1, 10, 100 U/ml). The culture supernatants were assayed for IL-8 using a sandwich ELISA and chemotactic activity was measured using a chemotactic chamber. Total RNA was also extracted from these cells and IL-8 mRNA was assayed by RT-PCR. In addition, TNF-receptor expression on the Et-treated cells was analyzed by flow cytometry. IL-8 levels in supernatants of cells stimulated with 100 U/ml of TNF-alpha for 48 h rose significantly with increasing concentrations of Et and values obtained were as follows: 4,918 +/- 244.4 pg/ml at 0 mmol/l Et, 5,335 +/- 266.2 pg/ml at 5 mmol/l Et, 8,726 +/- 873.4 pg/ml at 50 mmol/l Et and 9,134 +/- 866.0 pg/ml at 100 mmol/l Et. The chemotactic activity also increased with increasing concentrations of Et and was almost completely suppressed by anti-IL-8 antibody. Using semiquantitative analysis of radioactivity of IL-8 mRNA using a 32P gamma ATP-labeled primer for IL-8 mRNA, Et-treated cells were shown to have markedly higher levels of radioactivity than untreated cells. In addition, TNF-receptor expression was significantly higher in cells treated with 100 mmol/l Et. These data suggest that long-term Et treatment of Chang liver cells stimulated with TNF-alpha may enhance transcription of the IL-8 gene with up-regulation of the TNF receptor.

Interleukin-6 induces proliferation of rat hepatocytes in vivo.

BACKGROUND/AIMS: The aim of this study was to assess the effect of interleukin-6 (IL-6) on the proliferation of hepatocytes and to study the interaction between IL-6 and hepatocyte growth factor (HGF) in vivo. METHODS: IL-6 was injected at a dose of 200 micrograms/mg subcutaneously into rats every day for 14 days. Liver and blood samples were obtained at 1, 3, 7 and 14 days during IL-6 administration. Hepatocyte proliferative activity of sera was measured using 3H-thymidine incorporation into cultured rat hepatocytes. To evaluate the proliferative activity of the hepatocytes in tissue sections, hepatic DNA content and immunostaining of the liver tissue sections for proliferating cell nuclear antigen (PCNA) were performed. Plasma HGF levels were measured using specific EIA. In addition, total RNA was extracted from the liver and expression of HGF mRNA was detected by RT-PCR. RESULTS: The DNA contents of liver taken from IL-6-treated rats were increased during IL-6 administration compared with untreated rats. Sera taken from IL-6-treated rats at various intervals during administration also significantly increased 3H-thymidine incorporation by cultured rat hepatocytes compared with sera from untreated rats, suppressing 3H-thymidine incorporation at day 1 and 3 by anti-HGF antibody. IL-6 itself did not increase 3H-thymidine incorporation. Increased expression of PCNA in these hepatocytes was noted from 1 day after IL-6 administration, and at 14 days, the number of PCNA-positive cells was sevenfold greater than in the livers of untreated rats. However, plasma HGF levels showed a peak at day 1, decreased gradually from day 3, and became undetectable by day 14. HGF mRNA expression in livers of IL-6-treated rats was suppressed from day 3 to day 14 of IL-6 administration. CONCLUSIONS: These data show that IL-6 induces an early phase of liver cell growth in vivo and suggest that an increase level of HGF mediates this effect.

Effect of ethanol on DNA synthesis and c-met induction in Chang liver cells with long-term culture.

This investigation was performed to determine whether ethanol affects induction on Chang liver cells of the c-met protooncogene product (c-met), a cell-surface receptor for hepatocyte growth factor (HGF). These cells were cultured for 4 weeks with 5, 50, or 100 mmol/L ethanol, or 10, 100, or 200 mumol/L acetaldehyde. Ethanol was found to inhibit [3H]thymidine incorporation by cells in a dose-dependent manner. In addition, acetaldehyde at 100 mumol/L also inhibited [3H]thymidine uptake. Treatment with recombinant HGF led to enhanced [3H]thymidine incorporation by cells treated with ethanol or acetaldehyde as well as by those left untreated, with no significant differences in the rates of increase among these three cell groups. The amount of c-met messenger RNA, however, was unaffected by treatment with ethanol or acetaldehyde. Expression of c-met as measured by cell ELISA was also unchanged by both treatments. These results suggest that ethanol has no effect on c-met induction on Chang liver cells and that HGF may not be involved in the ethanol induced inhibition of DNA synthesis.