Infective endocarditis caused by Granulicatella elegans originating in the oral cavity

We studied the pheno- and genotypes of an oral Granulicatella elegans strain in comparison with those of a blood-derived isolate which caused infective endocarditis. The two isolates exhibited identical biochemical characteristics and had the same drug MICs. Their genotypes were indistinguishable, indicating that these were from the same clone. The transmission of G. elegans from the oral cavity thus should be noted as a possible cause of infective endocarditis.     

Association Between Glucan Synthesis by Streptococcus mutans and Caries Incidence in Schoolchildren Receiving a Fluoride Mouth Rinse

Purpose: To determine whether variation in glucan synthesis by Streptococcus mutans isolates is associated with caries development in children receiving a fluoride mouth rinse (FMR). Materials and Methods: Of 122 children (aged 9 to 10 years), 64 had received FMR (FMR(+) group) and the remaining 58 children had not (FMR(-) group). The number of decayed and filled teeth (DFT) and increases in the number of DFT in 1 year (dDFT) were recorded. Saliva samples were collected to isolate the clinical S. mutans strains. The isolates were incubated in heart infusion broth supplemented with 1% sucrose, then the amount of water-insoluble glucan (WIG) formed on a glass tube surface was evaluated. Results: In the FMR(-) group, children carrying S. mutans had a higher DFT (P = 0.039) and tended to have a higher dDFT (P = 0.080) than the others. In the FMR(+) group, although the differences between children with and without S. mutans were not significant, children carrying S. mutans that produced a high amount of WIG had higher dDFT than the other S. mutans-positive children (P = 0.034). Conclusions: This study revealed that the variation in glucan synthesis by S. mutans is associated with caries development in children receiving a FMR.     

Antioxidant and anti-inflammatory effects of a diet supplemented with sesamin on hepatic ischemia-reperfusion injury in rats

BACKGROUND/AIMS: The antioxidant and anti-inflammatory properties of sesamin (a non-fat constituent of sesame oil) have been attributed to an increased accumulation of dihomo-y-linolenic acid, a precursor of 1-series prostaglandins, and the decreasing production of proinflammatory 2-series prostaglandins and 4-series leukotrienes by inhibiting the delta-5 desaturase activity. We investigated the effects of a diet containing sesamin on hepatic ischemia-reperfusion injury in rats. METHODOLOGY: After feeding rats either a basal diet (control group) or a diet supplemented with sesamin (sesamin group) for 14 days, the rats underwent 60 minutes of partial hepatic ischemia and 3 hours of reperfusion. The phospholipid fatty acid composition of both liver and lung tissue specimens were then analyzed. The plasma levels of leukotriene B4 and PCOOH (phosphatidylcholine hydroperoxide) were also determined. RESULTS: The consumption of the dietary sesamin resulted in a significant increase in the dihomo-y-linolenic acid content in the tissue phospholipids of the liver and lung specimens. The amounts of polyunsaturated fatty acids in the lungs subjected to the ischemia-reperfusion injury were well preserved in the animals from the sesamin group. Despite a lack of differences in the levels of arachidonic acid, the plasma levels of leukotriene B4 in the rats fed dietary sesamin (88 +/- 15 pg) tended to be lower (P = 0.07) than those fed the control diet (110 +/- 20 pg). Furthermore, the plasma concentrations of PCOOH in the sesamin group (130 +/- 62 pmol) were also significantly lower (P < 0.05) than those in the control group (223 +/- 33 pmol). CONCLUSIONS: These findings indicate that a diet containing sesamin may thus reduce hepatic ischemia-reperfusion injury by inducing both antioxidant and anti-inflammatory activities.     

Arachidonate 5-lipoxygenase establishes adaptive humoral immunity by controlling primary B cells and their cognate T-cell help

In this study, we report the unique role of arachidonate 5-lipoxygenase (Alox5) in the regulation of specific humoral immune responses. We previously reported an L22 monoclonal antibody with which human primary resting B cells in the mantle zones of lymphoid follicles are well-defined. Proteomics analyses enabled identification of an L22 antigen as Alox5, which was highly expressed by naive and memory B cells surrounding germinal centers. Cellular growth of mantle cell lymphoma cells also seemed to depend on Alox5. Alox5(-/-) mice exhibited weak antibody responses specific to foreign antigens at the initial and recall phases. This was probably attributable to the low number of follicular and memory B cells and the functional loss of interleukin-21-mediated responses of follicular B cells. Moreover, Alox5(-/-) mice could not fully foster the development of follicular B helper T (Tfh) cells even after immunization with foreign antigens. Further experiments indicated that Alox5 affected mortality in experimentally induced enterocolitis in germ-prone circumstances, indicating that Alox5 would endow immunologic milieu. Our results illustrate the novel role of Alox5 in adaptive humoral immunity by managing primary B cells and Tfh cells in vivo.     

The efficacy of carbon-fiber resistive-heating in prevention of core hypothermia during major abdominal surgery

BACKGROUND: Perioperative hypothermia causes numerous severe complications, such as coagulopathy, surgical wound infections, and morbid myocardial outcomes. For prevention of intraoperative hypothermia, an inexpensive, non-disposable carbon fiber resistive warming system has been developed. METHODS: We evaluated the efficacy of resistive-heating, comparing to circulating-water mattress and forced-air warming system. Twenty four patients undergoing elective abdominal surgery were randomly assigned to warming with: 1) a circulating water mattress, 2) a lower-body forced-air system, or 3) a carbon-fiber, resistive-heating blanket. RESULTS: Tympanic membrane temperature in the first two hours of surgery decreased by 1.9 +/- 0.5 degrees C in the water mattress group, 1.0 +/- 0.6 degree C in the forced-air group, 0.8 +/- 0.2 degree C in the resistive-heating group. The decreases in core temperature by the end of surgery were 2.0 +/- 0.8 degrees C in the water mattress group, 0.6 +/- 1.1 degrees C in the forced-air group, and 0.5 +/- 0.4 degree C in the resistive blanket group, respectively. There was no significant difference in the changes of core temperature between the forced-air group and the resistive-heating group. No side effects related to resistive-heating blanket were observed. CONCLUSIONS: Even during major abdominal surgery, carbon-fiber resistive-heating maintains core temperature as effectively as forced air.     

Inhibitory effects of an ellagic acid glucoside, okicamelliaside, on antigen-mediated degranulation in rat basophilic leukemia RBL-2H3 cells and passive cutaneous anaphylaxis reaction in mice

Degranulation inhibitors in plants are widely used for prevention and treatment of immediate-type allergy. We previously isolated a new ellagic acid glucoside, okicamelliaside (OCS), from Camellia japonica leaves for use as a potent degranulation inhibitor. Crude extracts from leaves also suppressed allergic conjunctivitis in rats. In this study, we evaluated the in vivo effect of OCS using a pure sample and performed in vitro experiments to elucidate the mechanism underlying the extraordinary high potency of OCS and its aglycon. The IC(50) values for degranulation of rat basophilic leukemia cells (RBL-2H3) were 14 nM for OCS and 3 μM for aglycon, indicating that the two compounds were approximately 2 to 3 orders of magnitude more potent than the anti-allergic drugs ketotifen fumarate, DSCG, and tranilast (0.17, 3, and >0.3 mM, respectively). Antigen-induced calcium ion (Ca(2+)) elevation was significantly inhibited by OCS and aglycon at all concentrations tested (p<0.05). Upstream of the Ca(2+) elevation in the principle signaling pathway, phosphorylation of Syk (Tyr525/526) and PLCγ-1 (Tyr783 and Ser1248) were inhibited by OCS and aglycon. In DNA microarray-screening test, OCS inhibited expression of proinflammatory cytokines [interleukin (IL)-4 and IL-13], cytokine-producing signaling factors, and prostaglandin-endoperoxidase 2, indicating that OCS broadly inhibits allergic inflammation. During passive cutaneous anaphylaxis in mice, OCS significantly inhibited vascular hyperpermeability by two administration routes: a single intraperitoneal injection at 10 mg/kg and per os at 5 mg/kg for 7 days (p<0.05). These results suggest the potential for OCS to alleviate symptoms of immediate-type allergy.     

Phasic reward responses in the monkey striatum as detected by voltammetry with diamond microelectrodes

Reward-induced burst firing of dopaminergic neurons has mainly been studied in the primate midbrain. Voltammetry allows high-speed detection of dopamine release in the projection area. Although voltammetry has revealed presynaptic modulation of dopamine release in the striatum, to date, reward-induced release in awakened brains has been recorded only in rodents. To make such recordings, it is possible to use conventional carbon fibres in monkey brains but the use of these fibres is limited by their physical fragility. In this study, constant-potential amperometry was applied to novel diamond microelectrodes for high-speed detection of dopamine. In primate brains during Pavlovian cue-reward trials, a sharp response to a reward cue was detected in the caudate of Japanese monkeys. Overall, this method allows measurements of monoamine release in specific target areas of large brains, the findings from which will expand the knowledge of reward responses obtained by unit recordings.