72), postoperative renal dysfunction (odds ratio, 1 9), dialysis

72), postoperative renal dysfunction (odds ratio, 1.9), dialysis (odds ratio, 1.82), stroke (odds ratio, 2.6) arrhythmia (odds ratio, 1.42), and hospital stay > 7 days (odds ratio, 1.65).

Conclusions: Occult renal dysfunction is an independent risk factor for early mortality and morbidity in patients undergoing coronary artery bypass grafting. (J Thorac Cardiovasc Surg 2011;141:771-6)”
“Older human listeners demonstrate

perceptual deficits in temporal selleck products processing even when audibility has been controlled. These age-related auditory deficits in temporal processing are thought to originate in the central auditory pathway. Precise temporal processing is necessary to detect and discriminate auditory cues such as modulation frequency, modulation depth and envelope shape which are critical for perception of speech and environmental sounds. This

study aims to further understanding of temporal processing in aging using non-invasive electrophysiological measurements. Amplitude modulation following responses (AMFRs) and frequency modulation following responses (FMFRs) were recorded from aged (92-95-weeks old) and young (9-12-weeks old) Fischer-344 (F-344) rats for sinusoidally amplitude modulated (sAM) tones, PF-02341066 research buy sinusoidally frequency modulated (sFM) tones and ramped and damped amplitude modulation (AM) Amisulpride stimuli which differ in their envelope shapes. The modulation depth for the sAM and sFM stimuli and envelope shape for the ramped and damped stimuli were systematically varied. There was a monotonic decrease in AMFR and FMFR amplitudes with decreases in modulation depth across age for sAM and sFM stimuli. There was no significant difference between the response amplitudes of the young and aged animals for the largest modulation depths. However, a reduction in modulation depth resulted in a significant decrease in the response amplitudes and higher modulation detection thresholds for sAM and sFM stimuli

with age. The aged animals showed significantly lower response amplitudes for ramped stimuli but not for damped stimuli. Cross correlating the responses with the ramped, symmetric, or damped stimulus envelopes revealed a decreased fidelity in encoding envelope shapes with age. These results indicate that age related temporal processing deficits become apparent only with reduced modulation depths or when discriminating envelope shapes. This has implications for psychophysical or diagnostic testing as well as for constraining potential cellular and network mechanisms responsible for these deficits. (C) 2011 IBRO. Published by Elsevier Ltd. All rights reserved.

Ascorbic acid (0 1-10

mg/kg, i p , 1-10 mg/kg p o or 0 1

Ascorbic acid (0.1-10

mg/kg, i.p., 1-10 mg/kg p.o. or 0.1 nmol/mice i.c.v.) produced an antidepressant-like effect in the TST, but not in the FST without altering the locomotor activity. The effect of ascorbic acid (0.1 mg/kg, i.p.) in the TST was Acadesine order prevented by i.p. pre-treatment with NAN-190 (0.5 mg/kg), ketanserin (5 mg/kg), MDL72222 (0.1 mg/kg), prazosin (62.5 mu g/kg), yohimbine (1 mg/kg), propranolol (2 mg/kg), haloperidol (0.2 mg/kg), sulpiride (50 mg/kg), but not with SCH23390 (0.05 mg/kg, s.c.). Additionally, ascorbic acid (1 mg/kg, p.o.) potentiated the effect of subeffective doses (p.o. route) of fluoxetine (1 mg/kg), imipramine (0.1 mg/kg), or bupropion (1 mg/kg) in the TST. The combined treatment of ascorbic acid with antidepressants produced no alteration in the locomotion in the open-field test. In conclusion, our results show that administration of ascorbic acid produces an antidepressant-like effect in TST, which is dependent on its interaction with the monoaminergic system. Moreover, ascorbic acid caused a synergistic antidepressant-like effect with conventional antidepressants. Therefore, the present findings warrant further studies to evaluate the therapeutical relevance of ascorbic acid for the treatment

of depression and as a co-adjuvant treatment with antidepressants. (C) 2009 Elsevier Inc. All rights reserved.”
“Cisplatin is a highly effective chemotherapeutic drug; however, its use is limited by nephrotoxicity. Studies showed that the renal injury produced Caspase Inhibitor VI mw by cisplatin

ADP ribosylation factor involves oxidative stress and cell death mediated by apoptosis and necrosis in proximal tubular cells. The use of antioxidants to decrease cisplatin-induced renal cell death was suggested as a potential therapeutic measure. In this study the possible protective effects of carvedilol, a beta blocker with antioxidant activity, was examined against cisplatin-induced apoptosis in HK-2 human kidney proximal tubular cells. The mitochondrial events involved in this protection were also investigated. Four groups were used: controls (C), cisplatin alone at 25 mu M (CIS), cisplatin 25 mu M plus carvedilol 50 mu M (CV + CIS), and carvedilol alone 50 mu M (CV). Cell viability, apoptosis, caspase-9, and caspase-3 were determined. Data demonstrated that carvedilol effectively increased cell viability and minimized caspase activation and apoptosis in HK-2 cells, indicating this may be a promising drug to reduce nephrotoxicity induced by cisplatin.”
“To behave adaptively, we must learn from the consequences of our actions. Studies using event-related potentials (ERPs) have been informative with respect to the question of how such learning occurs. These studies have revealed a frontocentral negativity termed the feedback-related negativity (FRN) that appears after negative feedback.

Adult male rats underwent

either an FPI or sham injury A

Adult male rats underwent

either an FPI or sham injury. Additional rats were only exposed to anesthesia. HPA regulation was evaluated by measuring the effects of dexamethasone (DEX) treatment on CORT and ACTH. Tail vein blood was collected following 30-min restraint stress, at post-injury days (PID) 1, 7 and 14, prior to (0 min) and at 30, 60, 90 and 120 min after stress onset. Results from these studies indicate that the stress response was significantly more pronounced after FPI in that CORT and ACTH restraint-induced increases were more pronounced and longer lasting compared to controls. DEX suppression of CORT and ACTH was observed in all groups, suggesting that stress hyper-responsiveness after mild FPI is not attributable to reduced sensitivity of CORT feedback regulation. The increased sensitivity to stressful events in the first two post-injury weeks after check details a mild FPI may have a negative impact on early rehabilitative therapies. (c) 2011 IBRO.

Published by Elsevier Ltd. All rights reserved.”
“While endocannabinoid modulation of both GABAergic and glutamatergic synaptic transmission and plasticity has been extensively investigated, our understanding of the role of endocannabinoids in protecting neurons from harmful insults remains limited. 2-Arachidonoylglycerol (2-AG), the most abundant endogenous ligand and a full agonist Combretastatin A4 ic50 for cannabinoid receptors, exhibits anti-inflammatory and neuroprotective effects via a CBI receptor ZD1839 solubility dmso (CB1R)-mediated mechanism. However, it is still not clear whether 2-AG is also able to protect neurons from beta-amyloid (A beta)-induced neurodegeneration. Here, we demonstrate that exogenous application of 2-AG significantly protected hippocampal neurons in culture against A beta-induced neurodegeneration and apoptosis. This neuroprotective effect was blocked by SR141716 (SR-1), a selective CB1R antagonist,

but not by SR144528 (SR-2), a selective CB2R antagonist, or capsazepine (CAP), a selective transient receptor potential cation channels, subfamily V, member 1 (TRPV1) receptor antagonist. To determine whether endogenous 2-AG is capable of protecting neurons from A beta insults, hippocampal neurons in culture were treated with URB602 or JZL184, selective inhibitors of monoacylglycerol lipase (MAGL), the enzyme hydrolyzing 2-AG. MAGL inhibition that elevates endogenous levels of 2-AG also significantly reduced A beta-induced neurodegeneration and apoptosis. The 2-AG-produced neuroprotective effects appear to be mediated via CB1R-dependent suppression of extracellular signal-regulated kinases 1 and 2 (ERK1/2) and nuclear factor-kappa B (NF-kappa B) phosphorylation and cyclooxygenase-2 (COX-2) expression. Our results suggest that elevation of endogenous 2-AG by inhibiting its hydrolysis has potential as a novel efficacious therapeutic approach for preventing, ameliorating or treating Alzheimer’s disease. (c) 2011 IBRO. Published by Elsevier Ltd. All rights reserved.

Treatment with omacetaxine decreased the number of leukemia stem

Treatment with omacetaxine decreased the number of leukemia stem cells and prolonged the survival of mice with BCR-ABL-induced CML or B-ALL. Leukemia (2009) 23, 1446-1454; doi:10.1038/leu.2009.52; published online 26 March 2009″
“It has been suggested that different brain areas are involved in the modulation and expression of fear and anxiety. RG7112 ic50 In the present study we investigated these potential differences by using the fear-potentiated-startle (FPS) and light-enhanced-startle (LES) paradigms to differentiate between fear and anxiety, respectively.

Male Wistar rats were tested in the FPS and LES paradigm and perfused I h after the test session. Fos immunoreactivity (IR) was quantified in 21 brain areas and compared between FPS, LES and four PI3K inhibitor control conditions. Both FPS and LES procedures significantly enhanced the acoustic startle response. A principal component analysis of Fos-IR-data showed that 70% of the changes in Fos-IR could be explained by three independent components: an arousal-component, identifying brain areas known to be activated under conditions of vigilance, arousal and stress, a LES- and an FPS-component. The LES component comprised the septohippocampal system and functionally interrelated areas including nucleus accumbens, anterior cingulate cortex, lateral habenula and supramammillary

areas, but not the dorsolateral part of the bed nucleus of the stria terminalis. The central amygdaloid nucleus and the dorsolateral part of the bed nucleus of the stria terminalis loaded exclusively on the FPS component. Analysis of the separate brain areas revealed significantly higher Fos-IR in LES relative to FPS in the anterior cingulate cortex, nucleus accumbens shell, lateral septum, lateral habenula and area postrema. We conclude that the neural circuitry activated during FPS and LES shows clear differences. In anxiety as induced by LES, activation of the septohippocampal system and related areas seems to play a major role. In fear as induced by FPS, the central amygdaloid

nucleus and the dorsolateral part of the bed nucleus of the stria terminalis loaded on the same component, but Fos-IR observed in these brain regions did not differentiate between anxiety and fear. Furthermore, principal-component HSP90 analysis appears a useful tool in detecting and describing correlated changes in patterns of neuronal activity. (C) 2009 IBRO. Published by Elsevier Ltd. All rights reserved.”
“We reported that complement (C) becomes activated and cleaved in bone marrow during preconditioning for hematopoietic transplantation and the third C component (C3) cleavage fragments, C3a and (desArg)C3a, increase responsiveness of hematopoietic stem/progenitor cells (HSPCs) to stromal-derived factor-1 (SDF-1). We also showed that this homing-promoting effect is not C3a receptor (C3aR) dependent.

Using a genetically engineered variant of type O(1)Campos (O(1)C3

Using a genetically engineered variant of type O(1)Campos (O(1)C3056R) which can utilize both integrins and HS as receptors and a second variant (O(1)C3056R-KGE) which can utilize only HS as a receptor, we followed viral entry using confocal microscopy. After virus bound to cells at 4 C, followed by a temperature shift to 37 C, type O(1)C3056R-KGE colocalized with caveolin-1, while O(1)C3056R colocalized with both clathrin and caveolin-1. Compounds which either disrupt or inhibit the formation of lipid rafts inhibited the

replication of O(1)C3056R-KGE. Furthermore, a caveolin-1 knockdown by RNA interference also considerably reduced the efficiency of O(1)C3056R-KGE infection. PD98059 price These results indicate that HS-binding FMDV enters the cells via the caveola-mediated endocytosis pathway and that caveolae can associate and traffic with endosomes. In addition, these results further suggest that

the route of FMDV entry into cells is a function solely of the viral receptor.”
“Physical dependence on ethanol results in an ethanol withdrawal (ETX) syndrome including susceptibility to audiogenic seizures (AGS) in rodents after abrupt cessation of ethanol. Chronic ethanol administration and ETX induce functional changes of neurons in several GS-9973 brain regions, including the amygdala. Amygdala neurons are requisite elements of the neuronal network subserving AGS propagation during ETX induced by a subacute “”binge”" ethanol administration protocol. However, the effects of chronic ethanol administration on amygdala neuronal firing and ETX seizure behaviors are unknown. In the present study ethanol (5 g/kg) was administered intragastrically in Sprague-Dawley rats once daily for 28 days [chronic intermittent ethanol (CIE) protocol].

One week later the rats began receiving ethanol intragastrically three times daily for 4 days (binge protocol). Microwire electrodes were implanted prior to CIE or on the day after CIE ended to record extracellular action potentials in lateral amygdala (LAMG) neurons. The first dose of ethanol administered in the binge protocol following CIE treatment did not alter LAMG neuronal firing, which contrasts with see more firing suppression seen previously in the binge protocol alone. These data indicate that CIE induces neuroadaptive changes in the ETX network which reduce LAMG response to ethanol. LAIVIG neuronal responses to acoustic stimuli prior to AGS were significantly decreased during ETX as compared to those before ethanol treatment. LAMG neurons fired tonically throughout the tonic convulsions during AGS. CIE plus binge treatment resulted in a significantly greater mean seizure duration and a significantly elevated incidence of death than was seen previously with the binge protocol alone, indicating an elevated seizure severity following chronic ethanol administration. (c) 2008 Elsevier Ltd. All rights reserved.

Phys Rev B 1994, 50:14916 CrossRef 18 Cahangirov S, Topsakal M,

Phys Rev B 1994, 50:14916.CrossRef 18. Cahangirov S, Topsakal M, Aktuerk E, Seahin H, Ciraci S: Two- and one-dimensional honeycomb structures of silicon and NU7441 price germanium. Phys

Rev Lett 2009, 102:236804.CrossRef 19. Houssa M, Pourtois G, Afanasiev VV, Stesmans A: Can silicon behave like graphene? A first-principles study. Appl Phys Lett 2010, 97:112106.CrossRef 20. Vogt P, De Padova P, Quaresima C, Avila J, Frantzeskakis E, Asensio MC, Resta A, Ealet B, Le Lay G: Silicene: compelling experimental evidence for graphenelike two-dimensional silicon. Phys Rev Lett 2012, 108:155501.CrossRef 21. Fleurence A, Friedlein R, Ozaki T, Kawai H, Wang Y, Yamada-Takamura Yu: Experimental evidence for epitaxial silicene on diboride thin films. Phys Rev Lett 2012, 108:245501.CrossRef 22. Ziman JM: Electrons and Phonons. Oxford: Oxford University Press; 1960. 23. Klitsner T, VanCleve JE, Fisher HE, Pohl RO: Phonon radiative heat transfer and surface scattering. Phys Rev B 1988, 38:7576.CrossRef 24. Lim J, Hippalgaonkar K, Andrews SC, Majumdar A, Yang P: Quantifying surface roughness effects on phonon transport in silicon nanowires. Nano Lett 2475, 12:2012.

Competing interests The authors declare that they have no competing interests. Authors’ contributions This work was finished through the collaboration of all authors. YAK proposed the model for the lattice and isotopic effect. AVS has been working on the MD simulation. YAK and AC have participated in the interpretation of results and in revising the manuscript. All authors read and approved buy Alvocidib the final manuscript.”
“Background Due to their cost-effectiveness, ease of manufacturing, and suitability for large-area production, dye-sensitized solar cells (DSSCs) have attracted much attention. Typically, the photoanode of a DSSC is made of a TiO2 nanoparticle film (10-μm thickness) adsorbed with a monolayer Ru-based complex dye. Although the certified energy click here conversion efficiency of DSSCs has exceeded 12% [1], electrons generated from photoexcited dyes injected into the conduction band of TiO2 will pass through the grain boundaries and interparticle connections, which are strongly

influenced by the surface trapping/detrapping effect, leading to slow electron transport [2]. One-dimensional (1-D) nanostructures have superior MYO10 electron transport characteristics compared to nanoparticle-based systems [3, 4]. Several methods have been established for the preparation of 1-D structured TiO2, including nanowires [5, 6], nanotubes [7–10] and nanofibers. Among the methods for preparing 1-D TiO2 nanostructures, electrospinning provides a versatile, simple, and continuous process [11–13]. However, even though extremely fast electron transport is available in the 1-D nanostructures, these 1-D TiO2-based DSSCs usually show relatively lower efficiencies than nanoparticle-based ones, mainly because of low dye adsorption.

Insertion of a second copy of the prn genes into the Bp-WWD strai

Insertion of a second copy of the prn genes into the Bp-WWD strain Due to the low level of PRN expression, a second copy of the prn structural gene (under control of the 246 bp fha promoter and its own terminator) was introduced into the Bp-WWD chromosome (posn. 1345693) between the two pseudogenes of putative exported dehydrogenase (posn. 1344710-1345685) and a putative aspartate racemase (posn. 1345693-1346049) (Figure 5A). The pSKPD2Cm3 E. coli vector was constructed where the Cm R gene was inserted between

the upstream and downstream regions flanking the selected insertion site. Another vector was constructed using the same flanking regions and the prn gene under control of Selleckchem Omipalisib the fha promoter (Figure 5B). After insertion of the Cm R marker in the desired location, the Cm R gene was replaced by the prn functional block using the usual allelic-exchange selection and ISRIB mw screening procedures. Figure 5 Vectors for the insertion of a second copy of the prn gene into the B. pertussis chromosome. A: The insertion site for a second copy of the prn gene was selected between two abandoned genes carrying frameshift mutations and a deletion. B: Schematic structure of the prn gene under control of fha promoter and flanking with target integration site. C: Schematic structure of the prn gene under control of its

own promoter and flanking with target TPCA-1 chemical structure integration site. The B. pertussis strains isolated from this construction exercise did not express PRN and the expression level of the other (FHA, PT and hemolysin) antigens was not detectable (data not shown). It was tentatively concluded that the PRN product is toxic if overproduced under control of the stronger fha promoter and only escape mutants having lost the capacity to produce PRN or all virulence factors were viable. It was, therefore, decided to introduce the natural prn promoter in place of the fha promoter. The plasmid pSKPD25FpPRN3 was used to replace

the fha promoter by the original prn promoter to generate a functional cassette with its own natural promoter and terminator (Figure 5C). This functional cassette was inserted at the selected site by the usual allelic-exchange procedure to obtain PRKACG a strain with a second non-tandemly-repeated copy of the prn gene under control of its own promoter. The expected insertion was confirmed by PCR amplification with primers binding to the flanking regions internally in the prn gene. This strain was normally viable and was designated as Bp-WWE. Genetic stability of PT and PRN constructs in Bp-WWE The strain Bp-WWE was cultured and serially sub-cultured in Modified Stainer-Scholte (MSS) medium to reach approximately 50 generations. The last culture was diluted and plated onto MSS agar. Thirty isolated colonies were randomly picked, and analyzed for their S1 and prn genes by PCR (data not shown). The results showed that all colonies contained two copies of S1 and prn genes at the expected positions.

In addition, consistent with the results shown in Figure 3, it sh

In addition, consistent with the results shown in Figure 3, it showed that procedure-dependent

effects occurred before 48 h and were more pronounced in the DBA/2J strain. Figure 4 Overall mean fold changes in mRNA expression throughout the time course. A. Mean expression changes in mock-treated and infected DBA/2J and C57BL/6J mice across all 10 target PU-H71 host mRNAs in the 5-day time course of IAV infection. The analysis is based on the same data set as used for Figures 2 and 3. Mean fold change values and 95% confidence intervals (vertical lines) were calculated with the Dunnett’s Modified Tukey-Kramer test, using the dCt values (qRT-PCR) of all 10 host-encoded mRNAs as input. B. Schematic representation of the results shown in panel A. As reflected by the thickness of the lines, overall changes are more pronounced in the DBA/2J strain. Procedure-dependent effects are evident between 6 and 24 h in both strains, but infection-related changes begin to evolve and AZD9291 purchase peak earlier in the DBA/2J strain. Discussion This analysis of sequential changes in pulmonary expression

of several mRNAs after real or simulated IAV infection revealed effects that can be ascribed to anesthesia and/or the intranasal inoculation procedure. The results clearly demonstrate that the appropriate control group treated with a simulated anesthesia/infection should always be included in studies of IAV infection in mice that cover approximately the first 24 h

post infection. What might be the underlying pathophysiological mechanisms? Anesthesia is known to influence cytokine expression in humans, but actually appears to have an anti-inflammatory effect as, for instance, suggested by reduction of circulating Il6 levels [7–9]. The intranasal infection Carnitine dehydrogenase procedure appears to be a more likely candidate. Despite the relatively small volume of 20 μl that is used and the near physiological properties of PBS, we consider it likely that entry of PBS into the airway creates a stress response similar to that observed after fluid aspiration, including at least focal pulmonary hypoxia due to bronchospasm. Responsible mechanisms may both relate to stimulation of nerve endings in the airway epithelium and direct noxious stimulation of airway epithelial cells. Indeed, except for Irg1, three of the four mRNAs whose expression was regulated in response to mock treatment are known to be induced JPH203 supplier during a stress response or hypoxia at the cellular or tissue level (Retnla: [10]; Il6: e.g., [11]; Cxcl10: [12]). The fourth one, Irg1, is preferentially expressed in macrophages, is strongly induced during macrophage activation, and localizes to mitochondria [13, 14]. Its expression in stress or hypoxia has not been examined, and it would therefore be interesting to test whether it plays a role in these processes. The four interferon related genes (Stat1, Ifng, Ifnl2 and Mx1) were clearly induced in infected mice only.

0 mg/dL is 250 mL (5 mL/kg × 50 kg/L), while that for a patient w

0 mg/dL is 250 mL (5 mL/kg × 50 kg/L), while that for a patient weighing 70 kg with a SCr of 1.0 mg/dL is 300 mL, rather than 350 mL (5 mL/kg × 70 kg/L). In this study, 115 patients with kidney dysfunction underwent cardiac catheterization and angiography, and the amount of contrast media that was given adhered to the limit in 86 patients TGF-beta/Smad inhibitor and exceeded it in 29 patients. The incidence of CIN was significantly higher in the latter patients (21 %, 6/29 patients) than in the former patients (2 %, 2/86 patients). In a study of 391 patients who underwent PCI, the independent predictors of CIN were the volume of contrast media, eGFR, LVEF, and cardiogenic shock [52]. The risk of CIN was 25 %

among patients with a contrast medium dose-to-eGFR ratio (gram-iodine/eGFR) of ≥1, which was significantly higher than that in those with a gram-iodine/eGFR of <1 (3 %). A study of patients undergoing PCI investigated the effects of contrast volume on the incidence of AKI, defined as a ≥0.3 mg/dL or ≥50 % increase in SCr levels from baseline, in subgroups of patients stratified according to categories in which 1.0 represents the “maximum allowable contrast dose” (MACD; calculated by using the formula described earlier [51]), of <0.5, 0.5–0.75, 0.75–1.0, 1.0–1.5, 1.5–2.0, and >2.0 [53].

The incidence click here of AKI did not differ significantly among subgroups with a MACD ratio of ≤1, but increased in subgroups of patients with an MACD ratio of 1.0–1.5 (OR 1.60, 95 % CI 1.29–1.97), 1.5–2.0 (OR 2.02, 95 % CI 1.45–2.81), and >2.0 (OR 2.94, 95 % CI 1.93–4.48). The incremental use of contrast is associated with an increased risk of AKI. In a study of 421 patients who underwent contrast-enhanced CT with intravenous iodinated contrast media, Weisbord et al. [5] reported that the use of >100 mL of contrast media was associated with an increased risk of CIN (OR: 3.3, 95 % CI 1.0–11.5). Is the risk for developing CIN lower in patients receiving low- rather than high-osmolar contrast media? Answer: Patients with a high risk for

developing CIN should receive low-osmolar contrast media, which are less associated with CIN as compared with high-osmolar contrast media. In Japan, high-osmolar contrast media are not indicated for intravascular use. Does the risk for developing CIN differ Methane monooxygenase between iso- and low-osmolar contrast media? Answer: There has been no definite conclusion as to whether the risk of CIN differs between iso- and low-osmolar contrast media. Does the risk for developing CIN differ among different low-osmolar contrast media? Answer: There has been no definite conclusion as to whether the incidence of CIN differs among different low-osmolar contrast media. In a meta-analysis of 31 studies, that the selleck pooled odds of CKD (defined as a rise of SCr levels of more than 44 μmol/L) with non-ionic low-osmolar contrast media was 0.61 (95 % CI 0.48–0.77) times that of ionic high-osmolar contrast media [54].

019 and p = 0 032, respectively) Figure 7 Damage of biofilms of

019 and p = 0.032, respectively). Figure 7 Damage of biofilms of S. mutans wildtype and knock-out mutants for comC , comD and comE https://www.selleckchem.com/products/blz945.html by carolacton. Biofilms were grown under anaerobic conditions

for 24 h and stained with the LIVE/DEAD BacLight Bacterial Viability staining kit. Green and red fluorescence was determined in triplicate samples, and biofilm damage was calculated as check details reduction of the fluorescence ratio green/red compared to untreated controls. Standard deviations were calculated from 3 – 5 independent experiments. Thus, the comD knockout mutant was slightly less sensitive to carolacton than the wildtype. This could indicate that carolacton interferes with the membrane bound histidine kinase ComD. However, since the comC and comE mutants were

just as sensitive for carolacton as the wildtype, and since there was still considerable activity of carolacton against the comD mutant, other mechanisms must be more important. Influence of carolacton on a pcomX luciferase reporter strain ComX, an alternative sigma-factor, plays a key role in the quorum sensing system of S. mutans which controls not only genetic competence, but also stress tolerance and biofilm formation, leading to the suggestion to call it the “”X-state”" rather than competence see more [39]. ComX is positively induced by CSP through the response regulator ComE, but also by another two component system, CiaRH, and environmental stress [40]. ComX controls the late competence genes, including the machinery for DNA-uptake and processing, but also many other density dependent traits [36, 40–42]. Altogether 240 genes are directly or indirectly controlled by ComX [42]. To investigate the effect of carolacton on the promoter activity of comX a pcomX-luciferase reporter strain was

constructed. For the experiment a concentration of CSP (200 nM) was chosen that induced competence without causing substantial growth inhibition [42]. Figure 8A shows that a severe reduction of CSP-induced comX expression Thiamet G was caused by addition of carolacton to biofilms grown anaerobically. Furthermore carolacton led to a decrease of growth-dependent, basal comX-reporter activity. Maximum inhibition was seen 60 min post induction at the peak of comX expression. In planktonic culture (Figure 8B) similar results were obtained, but both the CSP induced expression of comX and its inhibition through carolacton occurred over a longer time, e.g. from 45 to 180 min post induction, possibly reflecting the lower cell density in the planktonic culture. Furthermore we found that carolacton reduced the growth-dependent comX-promoter activity of this reporter strain also in the absence of externally added CSP, both in biofilms and in planktonic culture. Figure 8 Effect of carolacton on the comX -promoter activity of S. mutans.