Wall teichoic acid-dependent phagocytosis of intact cell walls of Lactiplantibacillus plantarum elicits IL-12 secretion from macrophages.

Selected lactic acid bacteria can stimulate macrophages and dendritic cells to secrete IL-12, which plays a key role in activating innate and cellular immunity. In this study, we investigated the roles of cell wall teichoic acids (WTAs) displayed on whole intact cell walls (ICWs) of Lactiplantibacillus plantarum in activation of mouse macrophages. ICWs were prepared from whole bacterial cells of several lactobacilli without physical disruption, and thus retaining the overall shapes of the bacteria. WTA-displaying ICWs of several L. plantarum strains, but not WTA-lacking ICWs of strains of other lactobacilli, elicited IL-12 secretion from mouse bone marrow-derived macrophages (BMMs) and mouse macrophage-like J774.1 cells. The ability of the ICWs of L. plantarum to induce IL-12 secretion was abolished by selective chemical elimination of WTAs from ICWs, but was preserved by selective removal of cell wall glycopolymers other than WTAs. BMMs prepared from TLR2- or TLR4-deficient mouse could secret IL-12 upon stimulation with ICWs of L. plantarum and a MyD88 dimerization inhibitor did not affect ICW-mediated IL-12 secretion. WTA-displaying ICWs, but not WTA-lacking ICWs, were ingested in the cells within 30 min. Treatment with inhibitors of actin polymerization abolished IL-12 secretion in response to ICW stimulation and diminished ingestion of ICWs. When overall shapes of ICWs of L. plantarum were physically disrupted, the disrupted ICWs (DCWs) failed to induce IL-12 secretion. However, DCWs and soluble WTAs inhibited ICW-mediated IL-12 secretion from macrophages. Taken together, these results show that WTA-displaying ICWs of L. plantarum can elicit IL-12 production from macrophages via actin-dependent phagocytosis but TLR2 signaling axis independent pathway. WTAs displayed on ICWs are key molecules in the elicitation of IL-12 secretion, and the sizes and shapes of the ICWs have an impact on actin remodeling and subsequent IL-12 production.

Determination of isepamicin in human plasma by HPLC with fluorescence detection after derivatization using 6-aminoquinolyl-N-hydroxysuccinimidyl-carbamate.

A simple and rapid high-performance liquid chromatographic method has been developed for determination in human plasma of isepamicin (ISP), an aminoglycoside antibiotic agent. After protein precipitation and clean-up procedure to remove lipophilic contaminants, ISP is derivatized pre-column with 6-aminoquinolyl-N-hydroxysuccinimidyl-carbamate for fluorescence detection. Chromatographic separations are achieved using C(18) column and mobile phase consisting of 20 mM KH(2)PO(4) containing 8 mM triethylamine (pH 7.0) and acetonitrile (78/22, v/v). Amikacin was used as an internal standard. The calibration curve was linear over a concentration range of 0.5-50 microg/ml. The limit of quantification was 0.5 microg/ml. The intra- and inter-day variabilities of ISP were both less than 17.5%. Both derivatives were stable for at least a week at ambient condition. This assay procedure should have useful application in therapeutic drug monitoring of ISP.

Time-dependent induction of midazolam-1-hydroxylation enzymes in rats treated with St. John's wort.

Time-dependent effects of St. John's wort (SJW) on midazolam 1-hydroxylation were investigated in Wistar rats. Wistar rats treated with SJW (1000 mg/kg/d) for 1, 3, and 7 d were administered midazolam orally at a dose of 10 mg/kg. Oral clearance of midazolam in the SJW treated rats increased time dependently, and was significant after 7 d of treatment with SJW. The midazoram-1-hydroxylation activity in liver microsomes obtained from the SJW treated rats was significantly higher than in the control group. Linear correlation was observed between oral clearance and midazolam-1-hydroxylation activity in the liver microsomes, suggesting that CYP3A induction in liver mainly decreased the midazolam concentration in plasma. Immunoblotting revealed that the protein amount of CYP3A was induced within 3 d of SJW treatment. Since the midazolam-1-hydroxylation activity continuously increased for at least 7 d, the induction of CYP3A by SJW continued to cause interactions with drugs metabolized by CYP3A. It is important for persons receiving SJW for an extended time to consider its interactions with prescription drugs.

Fluvoxamine modulates pain sensation and affective processing of pain in human brain.

To better understand the antinociceptive effect of fluvoxamine, we measured regional cerebral blood flow during laser-evoked pain and hot sensations using H(2)15O positron emission tomography and also subjective pain and hot sensations before and after fluvoxamine or placebo administration for 7 days to 12 healthy volunteers. The subjectively rated pain score was significantly reduced by fluvoxamine administration. Painful stimuli activated multiple brain regions. After fluvoxamine administration the ipsilateral anterior cingulate cortex (ACC), contralateral insular cortex (IC), and contralateral secondary somatosensory cortex (SII) activations were reduced. The bilateral IC activation was also reduced in the placebo group. These results suggest that fluvoxamine specifically reduced activation of the ACC and SII, which are areas concerned with the affective and integrative components of pain.