Innate Immune Response against Staphylococcus aureus Preincubated with Subinhibitory Concentration of trans-Anethole.

The study aimed to analyze morphological and functional changes of Staphylococcus aureus cells due to trans-anethole (a terpenoid and the major constituent of fennel, anise, or star anise essential oils) exposition, and their consequences for human neutrophils phagocytic activity as well as IL-8 production (recognized as the major chemoattractant). The investigation included the evaluation of changes occurring in S. aureus cultures, i.e., staphyloxanthin production, antioxidant activities, cell size distribution, and cells composition as a result of incubation with trans-anethole. It was found that the presence of trans-anethole in the culture medium reduced the level of staphyloxanthin production, as well as decreased antioxidant activities. Furthermore, trans-anethole-treated cells were characterized by larger size and a tendency to diffuse in comparison to the non-treated cells. Several cell components, such as phospholipids and peptidoglycan, were found remarkably elevated in the cultures treated with trans-anethole. As a result of the aforementioned cellular changes, the bacteria were phagocytized by neutrophils more efficiently (ingestion and parameters associated with killing activity were at a higher level as compared to the control system). Additionally, IL-8 production was at a higher level for trans-anethole modified bacteria. Our results suggest that trans-anethole represents a promising measure in combating severe staphylococcal infections, which has an important translational potential for clinical applications.

Macrophage depletion ameliorates nephritis induced by pathogenic antibodies.

Kidney involvement affects 40-60% of patients with lupus, and is responsible for significant morbidity and mortality. Using depletion approaches, several studies have suggested that macrophages may play a key role in the pathogenesis of lupus nephritis. However, "off target" effects of macrophage depletion, such as altered hematopoiesis or enhanced autoantibody production, impeded the determination of a conclusive relationship. In this study, we investigated the role of macrophages in mice receiving rabbit anti-glomerular antibodies, or nephrotoxic serum (NTS), an experimental model which closely mimics the immune complex mediated disease seen in murine and human lupus nephritis. GW2580, a selective inhibitor of the colony stimulating factor-1 (CSF-1) receptor kinase, was used for macrophage depletion. We found that GW2580-treated, NTS challenged mice did not develop the increased levels of proteinuria, serum creatinine, and BUN seen in control-treated, NTS challenged mice. NTS challenged mice exhibited significantly increased kidney expression of inflammatory cytokines including RANTES, IP-10, VCAM-1 and iNOS, whereas GW2580-treated mice were protected from the robust expression of these inflammatory cytokines that are associated with lupus nephritis. Quantification of macrophage related gene expression, flow cytometry analysis of kidney single cell suspensions, and immunofluorescence staining confirmed the depletion of macrophages in GW2580-treated mice, specifically within renal glomeruli. Our results strongly implicate a specific and necessary role for macrophages in the development of immune glomerulonephritis mediated by pathogenic antibodies, and support the development of macrophage targeting approaches for the treatment of lupus nephritis.

Immunochemical determination of 2,4,6-trichloroanisole as the responsible agent for the musty odor in foods. 1. Molecular modeling studies for antibody production.

Nine antisera have been raised against 2,4,6-trichloroanisole (2,4,6-TCA) by immunizing them with three different haptens. With the spacer arm at the meta position, hapten A (3-(2,4,6-trichloro-3-methoxyphenyl)propanoic acid) preserved all of the functional groups of the target analyte. In hapten B (5-(2,4,6-trichlorophenoxy)pentanoic acid), the spacer was placed in the molecule substituting the methoxy group. Finally, hapten C (3-(3,5-dichloro-4-methoxyphenyl)propanoic acid) held the spacer arm at the para position instead of the chlorine atom of the target analyte. Using theoretical models, we have studied how the molecular geometry and the electronic distribution are affected by the introduction of the linker. The evaluation of the avidity of the resulting antibodies demonstrates that the orientation produced by the spacer arm must also be considered an essential aspect. The screening for competitive assays performed after synthesizing a battery of heterologous competitors has provided with these antibodies eight indirect enzyme-linked immunosorbent assays with acceptable properties. From the number of assays obtained, their maximal absorbance, their signal-to-noise ratio, the slope, and the IC(50) values obtained, it can be concluded that hapten C provided the best antibodies.

Direct micro-radioimmunoassay of the new renin inhibitor CGP 60536.

A solid phase method for direct radioimmunoassay in plasma of the new renin inhibitor CGP 60536 has been developed which does not require the extraction of the parent drug with organic solvents. The assay showed a good reproducibility down to plasma concentrations of 0.15 ng/ml (LOQ) with intra- and inter-assay coefficients of variation < or = 20%. The procedure, which requires only small volumes of plasma (25 microl), is simple to use and well suited for routine analysis. The method allows the investigation of the pharmacokinetics of CGP 60536 in animals and man given low oral doses of the drug.

Possible origin of the skin sensitization potential of isoeugenol and related compounds. (I). Preliminary studies of potential reaction mechanisms.

Although many simple chemicals can give rise to the phenomenon of allergic contact dermatitis, it is rare that the mechanism of reaction between the chemical hapten and skin protein is known. A further complication is that metabolic processes may produce substantial changes to a chemical penetrating skin. Thus the skin contactant may be regarded as a prohapten which will give rise to the true hapten in vivo. In this study, the possible reaction mechanisms for a number of related simple aromatic chemicals have been investigated. The approach taken was to evaluate potential reaction mechanisms by assessing the degree to which chemicals could cross-react in sensitization tests. By careful choice of chemicals, it was then possible to confirm (or reject) options. Using this approach, a number of reaction schemes were investigated for eugenol, isoeugenol, dihydroeugenol, anethole and several related chemicals. The patterns of sensitization obtained and the cross-reactions observed indicated clearly that electrophile/nucleophile interactions were unlikely to provide a complete explanation of the sensitization processes. Eugenol and isoeugenol are not mutually cross-reactive, yet both cross-reacted with dihydroeugenol. Examination of the possible reaction mechanisms allows the speculation that eugenol reacts in part via a phenolic radical mechanism, whilst isoeugenol reacts largely via formation of an orthoquinone. Both reaction mechanisms are proposed for dihydroeugenol.

Effects of antibodies against odorant binding proteins on electrophysiological responses to odorants.

Monoclonal antibodies against two olfactory mucosal proteins, one with affinity for anisole-like and the other for benzaldehyde-like compounds, were applied to mouse olfactory epithelium. Responses to three odorants (anisole, benzaldehyde and amyl acetate) were measured. Of 26 antibodies, three (12%) inhibited responses only to the odorant with affinity for the antigen, nine (35%) inhibited responses to all three odorants, and 14 (54%) were without effect. None reduced responses by as much as 50%. The data support the hypothesis that there is a class of related proteins in olfactory neuronal cell membranes that function as receptor molecules and that other mechanisms also mediate odorant stimulation.