Comprehensive understanding of DOM reactivity in anaerobic fermentation of persulfate-pretreated sewage sludge via FT-ICR mass spectrometry and reactomics analysis.

Understanding the composition and reactivity of dissolved organic matter (DOM) at molecular level is vital for deciphering potential regulators or indicators relating to anaerobic process performance, though it was hardly achieved by traditional analyses. Here, the DOM composition, molecular reactivity and transformation in the enhanced sludge fermentation process were comprehensively elucidated using high-resolution mass spectrometry measurement, and data mining with machine learning and paired mass distance (PMD)-based reactomics. In the fermentation process for dewatered sludge, persulfate (PDS) pretreatment presented its highest performance in improving volatile fatty acids (VFAs) production with the increase from 2,711 mg/L to 3,869 mg/L, whereas its activation in the presence of Fe (as well as the hybrid of Fe and activated carbon) led to the decreased VFAs production performance. In addition to the conventional view of improved decomposition and solubilization of N-containing structures from sludge under the sole PDS pretreatment, the improved VFAs production was associated with the alternation of DOM molecular compositions such as humification generating molecules with high O/C, N/C, S/C and aromatic index (AImod). Machine learning was capable of predicting the DOM reactivity classes with 74-76 % accuracy and found that these molecular parameters in addition to nominal oxidation state of carbon (NOSC) were among the most important variables determining the generation or disappearance of bio-resistant molecules in the PDS pretreatment. The constructed PMD-based network suggested that highly connected molecular network with long path length and high diameter was in favor of VFAs production. Especially, -NH related transformation was found to be active under the enhanced fermentation process. Moreover, network topology analysis revealed that CHONS compounds (e.g., C13H27O8N1S1) can be the keystone molecules, suggesting that the presence of sulfur related molecules (e.g., cysteine-like compounds) should be paid more attention as potential regulators or indicators for controlling sludge fermentation performance. This study also proposed the non-targeted DOM molecular analysis and downstream data mining for extending our understanding of DOM transformation at molecular level.

Gas flux cyclic regime at an open vent magmatic column inferred from seismic and acoustic records.

On August 7, 2014, a new effusive vent opened on the northern flank of Stromboli. A characteristic pattern was observed in both seismic and infrasonic signal amplitudes prior to this effusive eruption. The pattern consisted of the repeating cycle: (1) quiet phase, (2) puffing phase, and (3) explosion phase. Correlation between seismic and infrasound signal suggests that pulses in the puffing phase were caused by repetitive bursts of small gas pockets at the central crater, while the explosion phase coincided with an explosion at the central crater. We show that degassing of the magma column occurred in cycles of increasing gas flux, which controlled the transition from a bubbly flow (puffing phase), to a slug flow (explosion phase) gas regime. The quiet phase was characterized by a constant time length of 150 s, indicating that the gas rose in the magma column as well-organized waves of gas layers. These cycles represent cyclic changes of the gas flux regime in the shallow magma column, associated with increases in the magma-gas supply input rate before the effusive eruption.

Epidermal growth factor receptor inhibitors enhance susceptibility to Fas-mediated apoptosis in oral squamous cell carcinoma cells.

Molecular inhibition of epidermal growth factor receptor (EGFR) signaling is a promising cancer treatment strategy. We examined whether inhibition of EGFR signaling would affect the susceptibility of oral squamous cell carcinoma (OSCC) cells to Fas-mediated apoptosis. Treatment of OSCC cells with an anti-EGFR monoclonal antibody, C225, and an EGFR tyrosine kinase inhibitor, AG1478, which target the extracellular and intracellular domains of the receptor, respectively, inhibited phosphorylation of EGFR and its downstream effector molecule Akt and amplified the induction of Fas-mediated apoptosis. In OSCC cells treated with EGFR inhibitors, Fas-mediated apoptosis was accompanied by caspase-8 activation but not Bid cleavage. Caspase-3 and -8 inhibitors reduced the effect of EGFR inhibitors on Fas-mediated apoptosis in OSCC cells, but a caspase-9 inhibitor did not. These results indicate that the pro-apoptotic activity of EGFR inhibitors in OSCC cells depends on the extrinsic pathway of the caspase cascade. Although EGFR inhibitors did not affect the expression of Fas, the Fas-associated death domain protein, or procaspase-8 in OSCC cells, the inhibition downregulated cellular FLICE-inhibitory protein (c-FLIP). Moreover, knockdown of c-FLIP in HSC-2 cells with a small interfering RNA strongly enhanced Fas-mediated apoptosis. These results suggest that the EGFR signaling pathway may, in part, regulate Fas-mediated apoptosis in OSCC cells through c-FLIP expression.

Effect of combining epidermal growth factor receptor inhibitors and cisplatin on proliferation and apoptosis of oral squamous cell carcinoma cells.

Epidermal growth factor (EGF) is known to be involved in the proliferation and metastasis of squamous cell carcinoma (SCC), suggesting that the EGF receptor (EGFR) must also contribute to SCC development. In combination with conventional anti-cancer drugs, agents that block EGFR may represent an efficient means of inhibiting proliferation and inducing apoptosis in SCC cells. We investigated the effects of combining an anti-EGFR monoclonal antibody (C225) or an EGFR-selective tyrosine kinase inhibitor (AG1478) with the conventional anti-cancer drug cisplatin on the oral SCC (OSCC) cell lines NA and Ca9-22. We detected constitutive expression of EGFR on the cell membranes of both cell lines. OSCC cell proliferation was inhibited by C225, AG1478 and cisplatin in a dose-dependent manner. The combination of C225 or AG1478 with cisplatin at concentrations

Enhanced susceptibility to tumor necrosis factor-related apoptosis-inducing ligand-mediated apoptosis in oral squamous cell carcinoma cells treated with phosphatidylinositol 3-kinase inhibitors.

In general, oral squamous cell carcinoma (OSCC) cells are relatively resistant to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-mediated apoptosis during culture in vitro. Here, we studied the role of phosphatidylinositol 3-kinase (PI 3-K)/Akt in survival and apoptosis of these cells. The PI 3-K inhibitors wortmannin and LY294002 markedly suppressed phosphorylation of Akt and accelerated TRAIL-mediated apoptosis in OSCC cells. Addition of TRAIL to PI 3-K inhibitor-treated cells resulted in caspase-8 activation and loss of mitochondrial membrane potential. Furthermore, inhibitors of caspase-3, -8 and -9 reduced the accelerative effect of PI 3-K inhibitors on TRAIL-mediated apoptosis. These results suggest that the pro-apoptotic effect of PI 3-K inhibitors on TRAIL-mediated apoptosis may contribute to both the extrinsic and intrinsic pathways. Although PI 3-K inhibitors did not affect expression of the TRAIL receptors DR4 and DR5, we observed a marked reduction in expression of cellular FLICE-inhibitory protein (c-FLIP), Bcl-2, cellular inhibitor of apoptosis protein-1 (cIAP-1) and X-linked IAP (XIAP), whereas Bax was up-regulated and no significant difference was observed in expression of Bcl-xL, Bak or cIAP-2. Therefore, the PI 3-K/Akt signaling pathway provides partial regulation of TRAIL-mediated apoptosis in OSCC cells via modulation of c-FLIP, Bcl-2, Bax, cIAP-1 and XIAP expression. These results suggest that PI 3-K inhibitors may represent a novel strategy for overcoming resistance to TRAIL-mediated apoptosis in OSCC cells.

Hybrid Desmoplastic/Follicular Ameloblastoma of the Mandible: A Case Report and Review of the Literature.

Desmoplastic ameloblastoma (DA) is one of the 6 histopathological subtypes of ameloblastoma. Hybrid lesions in which histopathologically conventional ameloblastoma coexists with areas of DA are rare. A 40-year-old male was referred to our hospital complaining of a swelling in the right premolar region of the mandible. A panoramic radiograph showed an area of radiolucency with a well-defined corticated border, whereas computed tomography revealed a unilocular radiolucent lesion and buccal expansion together with cortical perforation. The lesion was treated via enucleation and curettage of the marginal bone and fenestration. A histopathological examination showed a hybrid ameloblastoma with a pronounced desmoplastic pattern and follicular changes. The patient's postoperative course has been favorable up to now, and no marked changes have been observed. We presented a case of hybrid ameloblastoma and reviewed the 36 reported cases of hybrid ameloblastoma that have been reported in the English literature.

Accelerative effect of a selective cyclooxygenase-2 inhibitor on Fas-mediated apoptosis in human neutrophils.

Inflammatory stimuli, such as cytokines, can induce cyclooxygenase-2 (COX-2) expression in neutrophils. Selective, anti-inflammatory COX-2 inhibitors have been developed for patients with acute inflammatory diseases. Recent work has shown that selective COX-2 inhibitors interfere with tumor cell growth. The purpose of this study was to examine the capability of selective COX-2 inhibitors on Fas-mediated apoptosis in cytokine-stimulated neutrophils. Tumor necrosis factor-alpha (TNF-alpha) and granulocyte-macrophage colony-stimulating factor (GM-CSF) enhanced prostaglandin E2 (PGE2) release through the induction of COX-2 in neutrophils. This effect was not seen with either interleukin (IL)-1beta or IL-8. TNF-alpha-and GM-CSF-induced PGE2 release was blocked by the addition of the selective COX-2 inhibitor, N-(2-cyclohexyloxy-4-nitrophenyl)-methanesulfonamide (NS-398; 1 microM). GM-CSF, IL-1beta and IL-8 suppressed Fas-mediated apoptosis in neutrophils; however, this effect was not seen with TNF-alpha. The anti-apoptotic effect of cytokines on Fas-mediated neutrophil apoptosis was attenuated by the addition of NS-398 (100 microM). These results suggest that NS-398 operates via two distinct mechanisms for regulating apoptosis and COX-2 activation in neutrophils. This distinction is indicated by the difference in concentration of NS-398 required for acceleration of Fas-mediated neutrophil apoptosis, and the inhibition of PGE2 synthesis. Moreover, NS-398 suppressed the anti-apoptotic activity of IL-8 and IL-1beta, but did not induce COX-2; therefore, the pro-apoptotic mechanism of the selective COX-2 inhibitor may be unrelated to COX-2 activity. Thus, a selective COX-2 inhibitor may contribute to the reduction of acute inflammation through the enhancement of neutrophil apoptosis.

Enhancement of susceptibility to Fas-mediated apoptosis in oral squamous cell carcinoma cells by phosphatidylinositol 3-kinase inhibitor.

In general, oral squamous cell carcinoma (OSCC) cells are relatively resistant to Fas-mediated apoptosis during in vitro culture. Here, we studied the role of survival/apoptosis associated phosphatidylinositol 3-kinase (PI 3-K)/Akt in this process. We found that both PI 3-K inhibitors, wortmannin and LY294002, markedly suppressed the phosphorylation of Akt and accelerated Fas-mediated apoptosis in OSCC cells. It was found that caspase-3 and -8 inhibitors reduced the accelerative effect of PI 3-K inhibitor on Fas-mediated apoptosis in OSCC cells, but not caspase-9 inhibitor. Although PI 3-K inhibitors did not affect the Fas expression of OSCC cells, cellular FLICE-inhibitory protein (c-FLIP) levels were markedly reduced by PI 3-K inhibitor treatment. Moreover, antisense oligonucleotide to c-FLIP confirmed that the down-regulation of c-FLIP enhanced the sensitization to Fas-mediated apoptosis in OSCC cells. These results suggest that PI 3-K/Akt signaling pathway may, in part, regulate Fas-mediated apoptosis in OSCC cells through c-FLIP expression.

Enhancement of susceptibility to Fas-mediated apoptosis in HL-60 cells through down-regulation of cellular FLICE-inhibitory protein by phosphatidylinositol 3-kinase inhibitors.

Promyelocytic leukemia HL-60 cells are resistant to Fas-mediated apoptosis. The signaling pathway for Fas-mediated apoptosis in various cells, including HL-60 cells, is currently unknown. Here, we studied the role of survival/apoptosis associated phosphatidylinositol 3-kinase (PI 3-K)/Akt in this process. We found that both PI 3-K inhibitors, wortmannin and LY294002, markedly suppressed phosphorylation of Akt and Bad in HL-60 cells. PI 3-K inhibitors significantly accelerated not only spontaneous apoptosis, but also Fas-induced apoptosis in HL-60 cells. The pro-apoptotic effect of PI 3-K inhibitors favored Fas-mediated apoptosis rather than spontaneous apoptosis in HL-60 cells. The caspase-3 or -8 inhibitor reduced the pro-apoptotic effect of the PI 3-K inhibitors for Fas-mediated apoptosis in HL-60 cells, but the caspase-9 inhibitor did not. Although PI 3-K inhibitors did not affect Fas expression in HL-60 cells, cellular FLICE-inhibitory protein (c-FLIP) levels were markedly reduced by PI 3-K inhibitor treatment. Furthermore, antisense oligonucleotide of c-FLIP confirmed that down-regulation of c-FLIP enhanced sensitization to Fas-mediated apoptosis in HL-60 cells. These results suggest that the PI 3-K/Akt signaling pathway may, in part, regulate Fas-mediated apoptosis in HL-60 cells through c-FLIP expression.

Suppressive effect of selective cyclooxygenase-2 inhibitor on cytokine release in human neutrophils.

To clarify whether a selective cyclooxygenase-2 (COX-2) inhibitor can affect various functions in human peripheral blood neutrophils. For this purpose, the effects of selective COX-2 inhibitors, NS-398 and nimesulide, on the expression of COX-2, PGE2 release and respiratory burst, degranulation and cytokine release in activated neutrophils were examined. Peripheral blood neutrophils were stimulated with formyl-methionyl-leucyl-phenylalanine (FMLP; 100 nM) or opsonized zymosan (OZ; 200 microg/ml). Then, the expression of COX-2 at protein and mRNA levels was detected by Western blot analysis and RT-PCR. The concentration of prostaglandin E2 (PGE2) and cytokines in the culture supernatant of neutrophils was determined using ELISA. Superoxide generation was measured by the cytochrome c reduction method. Elastase activity was measured using a chromogenic substrate assay specific for human neutrophil elastase. FMLP and OZ enhanced PGE2 release through induction of COX-2 protein and mRNA expression. FMLP- or OZ-induced PGE2 release was abolished by the addition of NS-398 or nimesulide; nevertheless, even a high concentration of COX-2 inhibitor did not change FMLP- or OZ-induced expression of COX-2 at message and protein levels. Although FMLP- or OZ-induced superoxide generation and elastase release were not affected by the addition of COX-2 inhibitor, cytokine release such as interleukin (IL)-1beta, IL-6 and IL-8 was significantly inhibited by high concentration of COX-2 inhibitor, but tumor necrosis factor-alpha (TNF-alpha) was partially attenuated. These studies showed that selective COX-2 inhibitors, NS-398 and nimesulide, suppressed PGE2 and proinflammatory cytokine release in activated neutrophils. These results suggest that selective COX-2 inhibitors may contribute to resolution of acute inflammation through the reduction of inflammatory cytokine release in activated neutrophils.

Regulation of Fas-mediated apoptosis in neutrophils after surgery-induced acute inflammation.

BACKGROUND: Neutrophils undergo rapid Fas-mediated apoptosis during in vitro culture. The purpose of this study was to investigate the effects of surgical stress upon the Fas-mediated apoptotic response in circulating neutrophils. MATERIALS AND METHODS: Blood samples were drawn from eight patients with a mandibular prognathism, and who had undergone a bilateral sagittal split ramus osteotomy, at 2 days before, and at 1 and 5 days after surgery. The circulating neutrophils in each blood sample were then evaluated for their susceptibility to Fas-mediated apoptosis in either the presence or the absence of autogenous plasma. RESULTS: Fas-induced apoptosis in the neutrophils of these surgically treated patients was found to be slightly accelerated at 1 day postoperatively in the presence of FBS, compared with 2 days preoperatively and 5 days postoperatively. However, we obtained different results for these experiments in the presence of autogenous plasma. The Fas-induced apoptotic response levels in the neutrophils at day 1 postsurgery following exposure to autogenous plasma were significantly suppressed compared with the levels at both 2 days preoperatively and 5 days postoperatively. The Fas expression levels on the cell surface of the neutrophils were not altered, but the levels of soluble Fas (sFas) in the plasma were reduced to almost inverse levels during the postoperative periods. The levels of granulocyte-macrophage colony-stimulating factor, interleukin-6, and interleukin-8 levels in the plasma were also markedly raised in the plasma from each of these patients at 1 day postoperatively. However, the anti-apoptotic effects of the plasma on the Fas-mediated neutrophil apoptosis were not influenced by the addition of their neutralizing antibodies for these cytokines. The suppressive effects of postoperative plasma on Fas-mediated neutrophil apoptosis were blocked by the phosphatidylinositol 3-kinase (PI 3-K) inhibitors, LY294002, and wortmannin. Additionally, these effects were also abrogated by the extracellular signal-regulated kinase (ERK) inhibitor, PD98059, but not by the p38 mitogen-activated protein kinase inhibitor, SB203580. CONCLUSIONS: The increase in sFas levels in the plasma of patients with acute inflammation may lead to the inhibition of Fas-mediated neutrophil apoptosis. Moreover, the activation of the PI 3-K and ERK signaling-dependent pathways may, in part, also contribute to the down-regulation of the Fas-mediated apoptotic response in neutrophils.

Modulation of neutrophil apoptosis in plasma of patients after orthognathic surgery.

BACKGROUND: Human neutrophils undergo rapid apoptosis during in vitro culture. The aim of this study was to investigate the role of interleukin-8 (IL-8) on neutrophil apoptosis in surgery-induced inflammation. MATERIALS AND METHODS: Blood samples were drawn from 21 patients with mandibular prognathism 2 days before, and 1 and 5 days after orthognathic surgery. The IL-8 levels in the separated plasma were measured using an ELISA kit. The expression of two receptors for IL-8, CXCR1, and CXCR2, and their role in neutrophil apoptosis was evaluated using a flow cytometer. RESULTS: The IL-8 levels in the plasma were correlated with acute inflammatory markers, such as peripheral blood neutrophil counts and C-reactive protein levels. Both IL-8 receptors were markedly raised in patient-derived neutrophils 1 day post-operatively. Recombinant IL-8 (0-100 ng/ml) suppressed apoptosis in fresh-isolated neutrophils from healthy donors dose-dependently. Neutrophil apoptosis 1 day post-operatively was slightly accelerated in the presence of fetal bovine serum compared to the value 2 days pre-operatively and 5 days post-operatively. In contrast, in the presence of autogenous plasma, neutrophil apoptosis was significantly suppressed 1 day post-operatively compared to the value 2 days pre-operatively and 5 days post-operatively. Moreover, the anti-apoptotic effect of plasma on neutrophil apoptosis was partially decreased by the addition of anti-IL-8 neutralizing antibody. CONCLUSIONS: These results suggest that circulating neutrophils are susceptible to augmentation by IL-8 through the reinforcement of IL-8 receptors in acute inflammatory conditions. Furthermore, IL-8 may, in part, contribute to the regulation of neutrophil survival during the inflammatory response.

Clinical evaluation of circulating interleukin-6 and interleukin-10 levels after surgery-induced inflammation.

BACKGROUND: It was previously reported that both pro- and anti-inflammatory cytokines are elevated in systemic inflammatory response syndrome (SIRS). Cytokine-mediated systemic neutrophil activation is a direct consequence of SIRS, and can lead to multiple organ dysfunction syndrome (MODS). This prospective study assessed the risk of SIRS and MODS after orthognathic surgery by measuring the circulating levels of inflammatory cytokines such as IL-6 and IL-10 as well as the neutrophil functions as a marker of organ failure. MATERIALS AND METHODS: Blood samples for the measurement of IL-6, IL-10, CRP, neutrophil counts, and neutrophil function were drawn from 21 patients with mandibular prognathism at 2 days before, and at 1 and 3 days after orthognathic surgery. The neutrophil function was estimated by superoxide production and elastase release under the stimulation of FMLP. RESULTS: Eight of the 21 patients were applicable to SIRS criteria 1 day postoperatively, and all of the subjects were excluded from SIRS criteria 3 days postoperatively. Although IL-6 and IL-10 levels were raised 1 day postoperatively, increased cytokine concentrations were decreased in most patients at 3 days postoperatively. The IL-6 concentration and the ratio of IL-6 to IL-10 were higher in the SIRS-matched group compared with the non-SIRS-matched group. Neutrophil priming for superoxide production and elastase release was discovered 1 day after orthognathic surgery, and differences in those values could not be distinguished between the groups. CONCLUSIONS: These results suggest that a few patients in whom high levels of circulating inflammatory cytokine and neutrophil-derived toxic factor continue may have a possibility of contracting severe diseases such as SIRS and MODS after orthognathic surgery. We conclude that the ratio of IL-6 to IL-10 may be a predictive factor in SIRS.

Enhanced susceptibility of oral squamous cell carcinoma cell lines to FAS-mediated apoptosis by cisplatin and 5-fluorouracil.

Our study was conducted to investigate whether anticancer drugs, cisplatin (CDDP) and/or 5-fluorouracil (5-FU), can modulate Fas-mediated apoptosis in oral squamous cell carcinoma (OSCC) cell lines. When OSCC cell lines, NA and HSC-4, were treated with CDDP and/or 5-FU, Fas and its mRNA expression on the plasma membrane were enhanced. An increase in caspase-3 and -8 activities was then observed by the addition of agonistic anti-Fas antibody, CH-11. Apoptosis of OSCC cells treated with anticancer drugs were significantly enhanced by CH-11, whereas untreated cells were nearly resistant to apoptosis. Moreover, the combination of CDDP and 5-FU resulted in an increasing susceptibility to apoptosis. Caspase-3 and -8 inhibitors, but not caspase-9 inhibitor, reduced Fas-mediated apoptosis enhanced by the anticancer drugs. Furthermore, OSCC cells treated with anticancer drugs exhibited decreased cellular FADD-like interleukin 1-converting enzyme-inhibitory protein (c-FLIP) levels, whereas neither the Fas-associated death domain-containing protein (FADD) nor procaspase-8 changed the expression. Moreover, antisense oligonucleotide to c-FLIP confirmed that down-regulation of c-FLIP induced sensitization to Fas-mediated apoptosis. These results suggest that CDDP and 5-FU may enhance the susceptibility to Fas-mediated apoptosis through down-regulation of c-FLIP. From these findings, a new potential strategy may be developed to improve the efficacy of anticancer drugs.