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In this study, we assessed whether apolipoprotein E (APOE) polymorphism affects inflammatory responses and mortality in the caecal ligation and puncture model of peritonitis. In addition, we determined the effects of APOE mimetic peptide administration in this sepsis model. Differences in survival between targeted replacement mice expressing the human APOE3 allele (APOE3TR) and the APOE4 allele (APOE4TR) mice were assessed. In a separate series of experiments, COG1410, an apoE-mimetic peptide, was administered intravenously at 12-hour intervals for 72 hours and compared to vehicle-treated control animals. End-points included mortality and serum levels of interleukin-1β, interleukin-6, interleukin-12 and tumour necrosis factor-alpha. Mice expressing the human APOE4 allele (n=16) demonstrated an increase in mortality following caecal ligation and puncture compared with APOE3TR mice (n=22; P=0.039). Administration of the apolipoprotein E mimetic COG1410 was well tolerated and APOE3TR mice treated with peptide (n=20) demonstrated a significant reduction in mortality compared with vehicle treated animals (n=20; P=0.007). A similar effect was also observed in APOE4TR animals, in which treatment with COG1410 was associated with reduced mortality compared with vehicle treatment (n=16 animals/group; P=0.027). COG1410 was also associated with a reduction in TNFα, interleukin-1β, interleukin-6 and interleukin-12 levels in both APOE3TR and APOE4TR (n=5 animals/group) assessed at 24 hours. Thus, administration of an apolipoprotein E-mimetic peptide is well tolerated, suppresses inflammatory responses, and improves mortality in a caecal ligation and puncture model of sepsis.

Apolipoprotein E (apoE) is a 34 kDa glycosylated protein with multiple biological properties. In addition to its role in cholesterol transport, apoE has in vitro immunomodulatory properties. Recent data suggest that these immunomodulatory effects of apoE may be biologically relevant, and apoE-deficient mice have altered immune responses after bacterial inoculation and increased susceptibility to endotoxemia induced by lipopolysaccharide (LPS). To better understand the mechanism by which apoE-modulates immune responses, we tested the role of human apoE isoforms in assays of human T cell proliferation, and analyzed the immune responses of apoE-deficient mice. Both the E3 and E4 isoforms of apoE induced similar suppression of human lymphocyte function in assays of T cell proliferation, including mitogenic responses to phytohaemagglutin (PHA), stimulation of the T cell receptor with alphaCD3, and antigen-specific response to tetanus toxoid. ApoE-deficient mice showed no quantitative differences in thymic, splenic, or bone marrow lymphocyte populations, nor were there in vitro abnormalities in splenocyte proliferation after stimulation with alphaCD3 to suggest an inherent T cell defect in apoE-deficient mice. ApoE deficient animals, however, had significantly higher levels of antigen-specific IgM after immunization with tetanus toxoid, and impaired delayed type hypersensitivity responses as compared to control C57-BL/6 mice.These results support a growing body of evidence demonstrating an interplay between lipid metabolism and immune responses, and suggest that apoE plays a biologically relevant role in regulating humoral and cell-mediated immunity.

To assess survival and functional outcome in patients endotracheally intubated after ischemic stroke (IS) or spontaneous intracerebral hemorrhage (ICH).

Both hyperthermia and glutathione depletion have been shown to increase the antineoplastic activity of melphalan. Investigations were carried out to define the toxicity and activity of melphalan given in conjunction with local (right hind limb) hyperthermia and L-buthionine-SR-sulphoximine (BSO)-mediated glutathione depletion to athymic mice bearing the melphalan-resistant human rhabdomyosarcoma xenograft TE-671 MR. Administration of 0-5 of the 10% lethal dose of melphalan to mice treated with BSO and hyperthermia (42°c for 70 min) resulted in a 53% mortality rate. The mortality rates for mice treated with melphalan alone (2.5%), hyperthermia alone (0%), melphalan plus BSO (13.5 %), melphalan plus hyperthermia (12.0%), and BSO plus hyperthermia (0%) were substantially lower than triple therapy. Histological examination of kidney, liver, colon, and small intestine sections taken from non-tumour-bearing animals revealed a marked increase in damage to the small intestine (cryptal necrosis and epithelial denudement) in animals receiving triple therapy compared with animals receiving any other treatment combination. Gavage administration of sterile water (1 ml twice a day) completely prevented mortality in animals receiving triple therapy. Treatment of tumour-bearing animals with triple therapy plus gavage demonstrated a statistically significant increase in tumour growth delay compared with animals receiving any other treatment combination.

Investigations with the melphalan-sensitive and -resistant human rhabdomyosarcoma xenografts TE-671 and TE-671 MR were performed to examine the effect of glutathione and polyamine modulation on thermosensitivity. Regimens of intraperitoneally injected and orally administered buthionine sulfoximine were utilized to achieve glutathione depletion to 8··7% and 13% of control levels in TE-671 and TE-671 MR, respectively. Animals treated with L-buthionine-S,R-sulfoximine and 42°°C or 43°°C hyperthermia for 70 min showed no detectable growth delays beyond those observed for hyperthermia alone. Hyperthermia at 42°°C of disaggregated TE-671 and TE-671 MR xenografts following growth in short-term culture was performed following preincubation with buthionine sulfoximine or 0··9% saline. Buthionine sulfoximine-mediated glutathione depletion produced a significant increase in hyperthermia-induced cytotoxicity only with TE-671 MR at 43°°C. Polyamine depletion was achieved with a 7-day orally administered course of MDL 72.175DA [(2R,5R)-6-heptyne,5-diamine dihydro-chloride], an irreversible inhibitor of ornithine decarboxylase. Although this treatment caused significant depletion of intracellular putrescine and spermidine levels, spermine levels remained relatively unaffected. No significant growth delays were observed in either xenograft line for animals treated with MDL 72.175DA or MDL 72.175DA plus hyperthermia as compared with untreated controls. These results contrast with previous work performed in vitroshowing synergism between glutathione or polyamine depletion and hyperthermia, and indicate that further studies are needed.

We report three patients (two children and one adult) with Guillain-Barré syndrome and magnetic resonance imaging evidence of gadolinium enhancement of the cauda equina and lumbar nerve roots. All three patients exhibited symmetric ascending paralysis and areflexia, and two (one child, one adult) suffered urinary incontinence and retention. Similar enhancement has been observed in patients with chronic inflammatory demyelinating polyneuropathy and suggests proximal nerve inflammation. Magnetic resonance imaging in Guillain-Barré syndrome and chronic imflammatory demyelinating polyneuropathy may have diagnostic utility.