We examined the antibacterial action of several tannins on plasma coagulation by Staphylococcus aureus and the effect of conventional chemotherapy combined with tannic acid below the MIC. Coagulation was inhibited in plasma containing tannic acid (100 mg/L), gallic acid (5000 mg/L), ellagic acid (5000 mg/L), (-)-epicatechin (1500 mg/L), (-)-epicatechin gallate (500 mg/L) or (-)-epigallocatechin gallate (200 mg/L) after incubation for 24 h. All tannins inhibited coagulation at a concentration below the MIC. The MICs of oxacillin and cefdinir for S. aureus were reduced to < or = 0.06 mg/L in Mueller-Hinton agar plates with tannic acid (100 mg/L) at a concentration below the MIC. The antistaphylococcal activity of tannic acid was reduced in plates with 10% rabbit blood, but not in those with 10% rabbit plasma. Membranous structures formed in a culture medium containing equal proportions of plasma and tryptic soy broth after incubation for 24 h. The colony counts of S. aureus in membranous structures in the medium containing oxacillin (40 mg/L) and tannic acid (100 mg/L) were c. 10-fold lower than those in medium containing oxacillin (40 mg/L) alone (P< 0.01). Tannic acid merits further investigation as a possible adjuvant agent against S. aureus skin infections treated with beta-lactam antibiotics.

The membrane lipid glucosylceramide (GlcCer) is continuously formed and degraded. Cells express two GlcCer-degrading β-glucosidases, glucocerebrosidase (GBA) and GBA2, located in and outside the lysosome, respectively. Here we demonstrate that through transglucosylation both GBA and GBA2 are able to catalyze in vitro the transfer of glucosyl-moieties from GlcCer to cholesterol, and vice versa. Furthermore, the natural occurrence of 1-O-cholesteryl-β-D-glucopyranoside (GlcChol) in mouse tissues and human plasma is demonstrated using LC-MS/MS and 13C6-labeled GlcChol as internal standard. In cells, the inhibition of GBA increases GlcChol, whereas inhibition of GBA2 decreases glucosylated sterol. Similarly, in GBA2-deficient mice, GlcChol is reduced. Depletion of GlcCer by inhibition of GlcCer synthase decreases GlcChol in cells and likewise in plasma of inhibitor-treated Gaucher disease patients. In tissues of mice with Niemann-Pick type C disease, a condition characterized by intralysosomal accumulation of cholesterol, marked elevations in GlcChol occur as well. When lysosomal accumulation of cholesterol is induced in cultured cells, GlcChol is formed via lysosomal GBA. This illustrates that reversible transglucosylation reactions are highly dependent on local availability of suitable acceptors. In conclusion, mammalian tissues contain GlcChol formed by transglucosylation through β-glucosidases using GlcCer as donor. Our findings reveal a novel metabolic function for GlcCer.

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PVL gene-positive S. aureus strains are involved in the development of multiple furuncles with more-intense erythema, particularly in healthy young adults. An understanding of the characteristics of furuncles due to PVL gene-positive strains might be useful for preventing the development of the severe systemic infections.

A major limitation in tissue engineering is the insufficient formation of blood vessels in implanted tissues, resulting in reduced cell density and graft size. We report here the fabrication of angiogenic cell sheets using a combination of two magnetic force-based techniques which use magnetite cationic liposomes (MCLs), magnetofection and magnetic cell accumulation. A retroviral vector encoding an expression cassette of vascular endothelial growth factor (VEGF) was labeled with MCLs, to magnetically attract the particles onto a monolayer of mouse myoblast C2C12 cells, for gene delivery. MCL-mediated infection increased transduction efficiency by 6.7-fold compared with the conventional method. During the fabrication of the tissue constructs, MCL-labeled cells were accumulated in the presence of a magnetic field to promote the spontaneous formation of a multilayered cell sheet. VEGF gene-engineered C2C12 (C2C12/VEGF) cell sheets, constructed using both magnetic force-based techniques, were subcutaneously transplanted into nude mice. Histological analyses revealed that on day 14 the C2C12/VEGF cell sheet grafts had produced thick tissues, with a high-cell density, and promoted vascularization. This suggests that the method described here represents a powerful strategy in tissue engineering.