Fecal tumor necrosis factor-alpha and calprotectin as differential diagnostic markers for severe diarrhea of small infants.

OBJECTIVE: The etiology of early-onset diarrhea of neonates and small infants that persists despite bowel rest is heterogeneous. Two different categories of disorders presenting with diarrhea in the first weeks of life can be distinguished: constitutive intestinal epithelial disorders (microvillus atrophy [MVA] or epithelial dysplasia [ED]) and immune-inflammatory disorders, (autoimmune enteropathy [AIE] or inflammatory colitis [IC]). We aimed to evaluate in a prospective manner the use of fecal inflammatory markers in the differential diagnosis of severe persistent diarrhea. MATERIAL AND PATIENTS: Twenty-five patients (17 males) were enrolled in this study (median age 8 months). Fourteen children had a constitutive enterocyte disorder (group 1: MVA = 8, ED = 6), and 11 patients had an immuno-inflammatory disease (group 2: AIE = 5, IC = 6). Stool samples were collected at the time of diagnosis and stored at -80 degrees until tumor necrosis factor (TNF)-alpha and calprotectin were measured by enzyme-linked immunoadsorbent assay. RESULTS: No significant differences in age at onset of diarrhea or in stool volumes were observed between both groups. In group 1, fecal TNF-alpha was undetectable/normal in 14 of 14 children, whereas group 2 showed dramatically elevated TNF-alpha levels (mean 3,104, range 237-18,078 pg/g) in 8 of 11 patients. Similarly, calprotectin levels were undetectable/normal in 14 of 14 patients in group 1 and highly raised in 11 of 11 patients in group 2 (median 1,145, range 375-3,095 mug/g), P < 0.01. Under therapy, these inflammatory parameters normalized. CONCLUSIONS: Determination of fecal inflammatory markers is a simple method helping to distinguish constitutive from immuno-inflammatory etiologies of severe persistent diarrhea. These data also suggest that constitutive enterocyte disorders are not accompanied by an inflammatory mucosal reaction.

Protective effects of the lipophilic redox conjugate tocopheryl succinyl-ethyl ferulate on HIV replication.

Previously, we demonstrated that ferulate ethyl and tocopherol reduced HIV replication. In this study, we investigate whether the conjugation of both compounds (O-tocopheryl succinyl O-ethyl ferulate) can increase HIV inhibition. We show here for the first time that O-tocopheryl succinyl O-ethyl ferulate inhibits 80% of HIV replication (HIV-1 acute infection and HIV transmission), inhibits cell lipoperoxidation and prevents cellular glutathione consumption. Compared to ferulate ethyl and tocopheryl succinyl, O-tocopheryl succinyl O-ethyl ferulate inhibits more HIV replication. This may be due in part to the great increase in the lipophilicity of this compound.

Comparison of oxidized low-density lipoprotein toxicity on EA.hy 926 cells and human vein endothelial cells: influence of antioxidant systems.

We compared the susceptibility to oxidized LDL cytotoxicity of primary human umbilical vein endothelial cells (HUVEC) and EA.hy 926 cells. EA.hy 926 endothelial cells were more susceptible than HUVEC. To determine the basis of this difference, we evaluated the enzymatic antioxidant machinery in the two cell types. The antioxidant enzyme activities of superoxide dismutase, catalase and glutathione peroxidase were significantly lower in EA.hy cells than in HUVEC: 54%, 71% and 8% of the HUVEC enzyme activities respectively. Pre-incubation of the EA.hy 926 endothelial cells with glutathione peroxidase (100 IU/ml) inhibited the cytotoxic effect of oxidized LDL. Superoxide dismutase (300 or 600 IU/ml) and catalase (300 or 600 IU/ml) had no effect. Compared to HUVEC, the higher susceptibility of EA.hy 926 cells to oxidized LDL induced injury may be associated with lower antioxidant defences, in particular with lower glutathione peroxidase activity which is known to eliminate lipid hydroperoxides and thereby to prevent the formation of damaging peroxyl radical intermediates.

Clastogenic factors in plasma of HIV-1 infected patients activate HIV-1 replication in vitro: inhibition by superoxide dismutase.

The frequent neoplastic disorders present in HIV-infected patients and the implication of oxidative stress in AIDS-Kaposi's sarcoma pathogenesis prompted us to study whether the mechanisms implicated in genotoxic effects of clastogenic factors (CFs) (i.e., chromosome damaging materials released by cells under conditions of oxidant stress) can play a role in HIV-1 expression and whether exogenous superoxide dismutase can inhibit the clastogenic and HIV-inducing effects of CFs. CFs were found in the plasma of all HIV-1 infected patients (n = 21) of this study group, in asymptomatic (CDC II) as well as in symptomatic patients (CDC IV). In addition to their chromosome damaging effect, CFs are able to upregulate HIV-1 expression in U1 cells and in PBMCs activated with PHA and IL2 at all time points (p < .05). Their formation, therefore, is an early event in the disease. It occured despite antiviral medication in these patients. Superoxide dismutase inhibited the clastogenic and the viral inducing effects (p < .05). On the basis of our findings, association of SOD mimetics or superoxide scavengers with antiviral drugs may be a new therapeutic approach. This polytherapy, if started early enough after infection, may prolong the latency period and limit the emergence of drug-resistant viral strains.

Immunocytochemical study of uptake of exogenous carrier-free copper-zinc superoxide dismutase by peripheral blood lymphocytes.

We recently demonstrated that exogenous copper-zinc superoxide dismutase (SOD) reduced HIV replication in tumor necrosis factor alpha activated chronically HIV-infected promonocytic U1 cell line and in peripheral blood mononuclear cells coculture. However, whether exogenous SOD penetrates the cellular membrane or acts extracellularly has been remained controversial. SOD has been considered as not to penetrate the cellular membrane because of its high molecular weight, thus the main site of action is presumed to be extracellular. In order to determine whether exogenous SOD penetrates inside the cell, we utilized a gentle immunocytochemical method to detect Mn and Cu,Zn SOD in peripheral blood lymphocytes incubated with various concentrations of exogenous carrier-free Cu,Zn SOD without prior permeabilization of cell membranes. After 24 hrs. the total SOD activity and immunocytochemical studies were performed. Here we demonstrate clearly that a large amount of carrier-free Cu,Zn SOD, added exogenously, penetrates the cellular membrane and increases total SOD activity.

[Effect of the liposolubility of free radical scavengers on the production of antigen P24 from a HIV infected monocytic cell line]. / Influence de la liposolubilité des molécules antiradicalaires sur la production d'antigène P24 par des cellules monocytaires infectées par le VIH.

A large body of evidence indicates that AIDS may be the consequence of a virus-induced antioxidant deficiency and implicates reactive oxygen species (ROS) in the pathogenesis of HIV infection. The high level of antigenic acid and cytokines activities in AIDS results in the production of superoxides (O2-), hydrogen peroxide (H202) and hydroxyl radicals (OH). HIV-infected T cells display low levels of SOD, catalase, thioredoxin and glutatione peroxidase rendering them susceptible to undergo apoptosis. Induction of NF kappa B and HIV replication are at least in part dependent on reactive oxygen intermediates. We examined the protective effects of two antioxidants. Ferulic Acid (FA) and Ethyl Ferulate (EF) at 1, 5, 10, 10 microM on the TNF induced HIV activation in the chronically infected promonocytic U1 cell line. FA and EF at 5 microM elicit a marked decrease of HIV p24 release. HIV inhibition was greater after pretreatment with EF than with FA. At these concentrations, no cytotoxicity was observed. When SOD (100 UI) was combined with EF and FA no more inhibition was observed. But when SOD was added alone, it induced a marked inhibition (30%). This class of drugs may present potential interest as antiviral agents or as adjuvant therapy in AIDS.