Longitudinal long term follow up investigation on the carcinogenic impact of polyhexamethylene guanidine phosphate in rat models.

Polyhexamethylene guanidine phosphate (PHMG-p) is a major component in humidifier disinfectants, which cause life-threatening lung injuries. However, to our knowledge, no published studies have investigated associations between PHMG-p dose and lung damage severity with long-term follow-up. Therefore, we evaluated longitudinal dose-dependent changes in lung injuries using repeated chest computed tomography (CT). Rats were exposed to low (0.2 mg/kg, n = 10), intermediate (1.0 mg/kg, n = 10), and high (5.0 mg/kg, n = 10) doses of PHMG-p. All rats underwent repeated CT scans after 10 and 40 weeks following the first exposure. All CT images were quantitatively analyzed using commercial software. Inflammation/fibrosis and tumor counts underwent histopathological evaluation. In both radiological and histopathologic results, the lung damage severity increased as the PHMG-p dose increased. Moreover, the number, size, and malignancy of the lung tumors increased as the dose increased. Bronchiolar-alveolar hyperplasia developed in all groups. During follow-up, there was intergroup variation in bronchiolar-alveolar hyperplasia progression, although bronchiolar-alveolar adenomas or carcinomas usually increase in size over time. Thirty-three carcinomas were detected in the high-dose group in two rats. Overall, lung damage from PHMG-p and the number and malignancy of lung tumors were shown to be dose-dependent in a rat model using repeated chest CT scans during a long-term follow-up.

Hematotoxic Effect of Respiratory Exposure to PHMG-p and Its Integrated Genetic Analysis.

Polyhexamethylene guanidine phosphate (PHMG-p), the main ingredient of humidifier disinfectants, circulates systemically through the lungs; however, its toxicological assessment has been primarily limited to pulmonary disease. Herein, we investigated the possible abnormalities in hematopoietic function 20 weeks after intratracheal instillation of PHMG-p in a rat model. Notable abnormalities were found out in the peripheral blood cell count and bone marrow (BM) biopsy, while RNA sequencing of BM tissue revealed markedly altered gene expression. Furthermore, signaling involved in hematopoietic dysfunction was predicted by analyzing candidate genes through Ingenuity Pathway Analysis (IPA) program. Respiratory PHMG-p exposure significantly decreased monocyte and platelet (PLT) counts and total protein, while significantly increasing hemoglobin and hematocrit levels in peripheral blood. Histopathological analysis of the BM revealed a reduced number of megakaryocytes, with no significant differences in spleen and liver weight to body weight. Moreover, PHMG-p exposure significantly activated estrogen receptor signaling and RHOA signaling, and inhibited RHOGDI signaling. In IPA analysis, candidate genes were found to be strongly related to 'hematological system development and function' and 'hematological disease.' Accordingly, our results suggest that PHMG-p could affect hematopoiesis, which participates in monocyte differentiation and PLT production, and may induce hematologic diseases via the respiratory tract.

Exposure to airborne particulate matter induces renal tubular cell injury in vitro: the role of vitamin D signaling and renin-angiotensin system.

Background: Exposure to air pollution can interfere with the vitamin D endocrine system. This study investigated the effects of airborne particulate matter (PM) on renal tubular cell injury in vitro and explored the underlying mechanisms. Methods: HK-2 human renal proximal tubule cells were treated with PM with or without 1,25(OH)2D3 analog, 19-Nor-1,25(OH)2D2 (paricalcitol, 10 nM) for 48 h. The dose- and time-dependent cytotoxicity of PM with or without paricalcitol was determined via cell counting kit-8 assay. Cellular oxidative stress was assessed using commercially available enzyme-linked immunosorbent assay kits. The protein expression of vitamin D receptor (VDR), cytochrome P450(CYP)27B1, CYP24A1, renin, angiotensin converting enzyme (ACE), angiotensin II type 1 receptor (AT1), nuclear factor erythroid 2-related factor 2 (Nrf2), nuclear factor-kB (NF-kB), tumor necrosis factor (TNF)-α, and interleukin (IL)-6 was determined. Results: PM exposure decreased HK-2 cell viability in a dose- and time-dependent manner. The activities of superoxide dismutase and malondialdehyde in HK-2 cells increased significantly in the group exposed to PM. PM exposure decreased VDR and Nrf2, while increasing CYP27B1, renin, ACE, AT1, NF-kB, TNF-α, and IL-6. The expression of VDR, CYP27B1, renin, ACE, AT1, and TNF-α was reversed by paricalcitol treatment. Paricalcitol also restored the cell viability of PM-exposed HK-2 cells. Conclusion: Our findings indicate that exposure to PM induces renal proximal tubular cell injury, concomitant with alteration of vitamin D endocrine system and renin angiotensin system. Vitamin D could attenuate renal tubular cell damage following PM exposure by suppressing the renin-angiotensin system and by partially inhibiting the inflammatory response.

Analysis of lung cancer-related genetic changes in long-term and low-dose polyhexamethylene guanidine phosphate (PHMG-p) treated human pulmonary alveolar epithelial cells.

BACKGROUND: Lung injury elicited by respiratory exposure to humidifier disinfectants (HDs) is known as HD-associated lung injury (HDLI). Current elucidation of the molecular mechanisms related to HDLI is mostly restricted to fibrotic and inflammatory lung diseases. In our previous report, we found that lung tumors were caused by intratracheal instillation of polyhexamethylene guanidine phosphate (PHMG-p) in a rat model. However, the lung cancer-related genetic changes concomitant with the development of these lung tumors have not yet been fully defined. We aimed to discover the effect of long-term exposure of PHMG-p on normal human lung alveolar cells. METHODS: We investigated whether PHMG-p could increase distorted homeostasis of oncogenes and tumor-suppressor genes, with long-term and low-dose treatment, in human pulmonary alveolar epithelial cells (HPAEpiCs). Total RNA sequencing was performed with cells continuously treated with PHMG-p and harvested after 35 days. RESULTS: After PHMG-p treatment, genes with transcriptional expression changes of more than 2.0-fold or less than 0.5-fold were identified. Within 10 days of exposure, 2 protein-coding and 5 non-coding genes were selected, whereas in the group treated for 27-35 days, 24 protein-coding and 5 non-coding genes were identified. Furthermore, in the long-term treatment group, 11 of the 15 upregulated genes and 9 of the 14 downregulated genes were reported as oncogenes and tumor suppressor genes in lung cancer, respectively. We also found that 10 genes of the selected 24 protein-coding genes were clinically significant in lung adenocarcinoma patients. CONCLUSIONS: Our findings demonstrate that long-term exposure of human pulmonary normal alveolar cells to low-dose PHMG-p caused genetic changes, mainly in lung cancer-associated genes, in a time-dependent manner.

Evaluation of the effect of filtered ultrafine particulate matter on bleomycin-induced lung fibrosis in a rat model using computed tomography, histopathologic analysis, and RNA sequencing.

We aimed to investigate the effect of chronic particulate matter (PM) exposure on bleomycin-induced lung fibrosis in a rat model using chest CT, histopathologic evaluation, and RNA-sequencing. A bleomycin solution was intratracheally administrated to 20 male rats. For chronic PM exposure, after four weeks of bleomycin treatment to induce lung fibrosis, PM suspension (experimental group) or normal saline (control group) was intratracheally administrated for 10 weeks. Chest CT was carried out in all rats, and then both lungs were extracted for histopathologic evaluation. One lobe from three rats in each group underwent RNA sequencing, and one lobe from five rats in each group was evaluated by western blotting. Inflammation and fibrosis scores in both chest CT and pathologic analysis were significantly more aggravated in rats with chronic PM exposure than in the control group. Several genes associated with inflammation and immunity were also upregulated with chronic PM exposure. Our study revealed that chronic PM exposure in a bleomycin-induced lung fibrosis rat model aggravated pulmonary fibrosis and inflammation, proven by chest CT, pathologic analysis, and RNA sequencing.

MTF1 Is Essential for the Expression of MT1B, MT1F, MT1G, and MT1H Induced by PHMG, but Not CMIT, in the Human Pulmonary Alveolar Epithelial Cells.

The inhalation of humidifier disinfectants (HDs) is linked to HD-associated lung injury (HDLI). Polyhexamethylene guanidine (PHMG) is significantly involved in HDLI, but the correlation between chloromethylisothiazolinone (CMIT) and HDLI remains ambiguous. Additionally, the differences in the molecular responses to PHMG and CMIT are poorly understood. In this study, RNA sequencing (RNA-seq) data showed that the expression levels of metallothionein-1 (MT1) isoforms, including MT1B, MT1E, MT1F, MT1G, MT1H, MT1M, and MT1X, were increased in human pulmonary alveolar epithelial cells (HPAEpiCs) that were treated with PHMG but not in those treated with CMIT. Moreover, upregulation of MT1B, MT1F, MT1G, and MT1H was observed only in PHMG-treated HPAEpiCs. The protein expression level of metal regulatory transcription factor 1 (MTF1), which binds to the promoters of MT1 isoforms, was increased in PHMG-treated HPAEpiCs but not in CMIT-treated HPAEpiCs. However, the expression of early growth response 1 (EGR1) and nuclear receptor superfamily 3, group C, member 1 (NR3C1), other transcriptional regulators involved in MT1 isomers, were increased regardless of treatment with PHMG or CMIT. These results suggest that MTF1 is an essential transcription factor for the induction of MT1B, MT1F, MT1G, and MT1H by PHMG but not by CMIT.

Evaluation of the long-term effect of polyhexamethylene guanidine phosphate in a rat lung model using conventional chest computed tomography with histopathologic analysis.

There have been no studies on the effects of polyhexamethylene guanidine phosphate (PHMG) after a long period of exposure in the rodent model. We aimed to evaluate long-term lung damage after PHMG exposure using conventional chest computed tomography (CT) and histopathologic analysis in a rat model. A PHMG solution was intratracheally administrated to 24 male rats. At 8, 26, and 52 weeks after PHMG instillation, conventional chest CT was performed in all rats and both lungs were extracted for histopathologic evaluation. At 52 weeks after PHMG instillation, four carcinomas had developed in three of the eight rats (37.5%). Bronchiolo-alveolar hyperplasia and adenoma were found in rats at 8, 26, and 52 weeks post-instillation. The number of bronchiolo-alveolar hyperplasia significantly increased over time (P-value for trend< 0.001). The severity of lung fibrosis and fibrosis scores significantly increased over time (P-values for trend = 0.002 and 0.023, respectively). Conventional chest CT analysis showed that bronchiectasis and linear density scores suggestive of fibrosis significantly increased over time (P-value for trend < 0.001). Our study revealed that one instillation of PHMG in a rat model resulted in lung carcinomas and progressive and irreversible fibrosis one year later based on conventional chest CT and histopathologic analysis. PHMG may be a lung carcinogen in the rat model.

Clinicopathological features of colorectal polyps in 2002 and 2012.

BACKGROUND/AIMS: There are few comparative studies on the historical changes in the clinicopathologic characteristics of colorectal polyps in Korea. This retrospective study compared the clinicopathologic characteristics of colorectal polyps treated at our institution in 2002 and 2012. METHODS: The medical records of 1,816 patients who underwent colonoscopy and were found to have colorectal polyps in 2002 (n = 597) or 2012 (n = 1,219) were reviewed retrospectively. Patient characteristics and polyp sizes, gross morphologies, locations, and pathologic results were analyzed and compared. RESULTS: Mean age was older in the 2002 group than in the 2012 group (67.3 ± 11.1 years vs. 55.4 ± 10.8 years, p < 0.001). The 1,816 study subjects had a total of 3,723 colorectal polyps, with a mean of 2.05 polyps per patient. Mean polyp size was larger in the 2002 group than in the 2012 group (0.6 ± 0.4 cm vs. 0.4 ± 0.3 cm, p < 0.001). The most common histology was tubular adenoma and they were more common in the right colon in both study groups. Although the distribution of total adenoma was not significantly different between groups, the location of advanced adenoma differed significantly and was more common in the right colon in the 2012 group (30.4% vs. 63.2%, p = 0.01). CONCLUSION: No significant change in total polyps and adenoma distribution was found between 2002 and 2012. However, advanced adenoma was more common in the right colon in 2012, which cautiously suggests a locational shift from the left to right colon. These findings indicate that right colon polyps require more attention.

Is endoscopic sphincterotomy beneficial for the treatment of acute gallstone pancreatitis with small bile duct stone?

BACKGROUND: Acute gallstone pancreatitis occurs when a gallstone is impacted at the ampulla of Vater. The role of endoscopic retrograde cholangiopancreatography in the treatment of small choledocholithiasis in these patients is uncertain. The aim of this study was to compare outcomes of expectant management with endoscopic sphincterotomy for the treatment of small choledocholithiasis (≤5 mm) in patients with acute gallstone pancreatitis. PATIENTS AND METHODS: Of the 258 patients admitted for acute gallstone pancreatitis from January 2010 to December 2014, 174 patients with small choledocholithiasis were reviewed retrospectively. Patients with coexisting acute cholangitis and/or pancreatobiliary malignancy were excluded. They were divided into an endoscopic sphincterotomy group (n=64) and an expectant management group (n=110). Severity index and outcomes of pancreatitis, complications, and overall mortality were compared. RESULTS: Age and sex were not significantly different between the two groups. The mean Ranson, acute physiology and chronic health evaluation-II, and bedside index of severity in acute pancreatitis scores were not significantly different between the two groups. The computed tomography severity index score was significantly higher in the expectant management group than in the endoscopic sphincterotomy group (1.6±1.1 vs. 1.0±0.9, P<0.001). Duration of hospitalization, time for normalization of the white blood cell count, and time for oral feeding were similar in both groups. There was no significant difference between two groups in the incidence of development of pseudocyst or walled-off necrosis. In addition, no difference was observed in the rate of recurrence of acute pancreatitis and readmission because of recurrent choledocholithiasis. CONCLUSION: Expectant management seems to be effective for the treatment of patients with acute gallstone pancreatitis and size of bile duct stones equal to or less than 5 mm.

Prospective analysis of factors associated with inadequate bowel preparation for colonoscopy in actual clinical practice.

BACKGROUND/AIMS: Inadequate bowel preparation can result in prolonged procedure time and increased missed lesion and complication rates. This prospective study aimed to evaluate bowel preparation quality and identify the predictive factors for inadequate bowel preparation in actual clinical practice. METHODS: We included 399 patients who underwent colonoscopy between June 2015 and July 2016. Using the Aronchick bowel preparation scale, we defined a score ≤2 as adequate preparation and a score >2 as inadequate preparation. RESULTS: Mean patient age was 58.38±12.97 years; 60.6% were male. Indications for colonoscopy included screening (69.7%) and surveillance after polyp removal (21.3%). A split-dose regimen was prescribed to 55.4% of patients. The inadequate bowel preparation rate was 28.1%. Overall, the median time between the last bowel preparation agent dose and start of colonoscopy was 5.0 hours (range, 1.5-16.0 hours); that of the adequate group was 5.0 hours (range, 1.5-16.0 hours); and that of the inadequate group was 5 hours (range, 2-23 hours). The mean bowel preparation scale score of the ascending colon (1.94±0.25) was significantly higher than that of other colon segments. On multivariate analysis, elderly age, history of cerebrovascular disease, history of gastrectomy or appendectomy, and total preparation solution uptake <2 L were the independent predictors of inadequate bowel preparation. CONCLUSIONS: The inadequate bowel preparation rate was 28.1%. Risk factors included elderly age and history of cerebrovascular disease or abdominal surgery. Patients with these risk factors require special care and education.

Protocatechuic acid inhibits Toll-like receptor-4-dependent activation of NF-κB by suppressing activation of the Akt, mTOR, JNK and p38-MAPK.

Protocatechuic acid has demonstrated to have antioxidant and anti-inflammatory effects. We assessed whether protocatechuic acid may reduce the inflammatory mediator production, which is regulated by the Toll-like receptor-4-dependent Akt, mTOR and NF-κB pathway, and JNK and p38-MAPK in HaCaT cells and primary keratinocytes. Protocatechuic acid, Akt inhibitor, Bay 11-7085 and N-acetylcysteine reduced the lipopolysaccharide-caused production of cytokines and chemokines, expression of cyclooxygenase, increase in the levels and activities of Toll-like receptor-4, p-Akt and mTOR, activation of NF-κB, phosphorylation of the JNK and p38-MAPK, and production of reactive oxygen species in keratinocytes. Inhibitors of the c-JNK (SP600125) and p38-MAPK (SB203580) reduced lipopolysaccharide-caused production of inflammatory mediators, activation of the JNK and p38-MAPK, and production of reactive oxygen species in keratinocytes. These results show that protocatechuic acid may inhibit the lipopolysaccharide-stimulated inflammatory mediator production in keratinocytes by reducing the Toll-like receptor-4-dependent activation of Akt, mTOR and NF-κB pathways, and activation of JNK and p38-MAPK. The suppressive effect of protocatechuic acid appears to be associated with inhibition of the reactive oxygen species production. Protocatechuic acid appears to reduce the microbial product-caused inflammatory skin diseases.

Taxifolin reduces the cholesterol oxidation product-induced neuronal apoptosis by suppressing the Akt and NF-κB activation-mediated cell death.

The taxifolin effect on the cholesterol oxidation product-induced neuronal apoptosis was investigated using differentiated PC12 cells and human neuroblastoma SH-SY5Y cells. 7-ketocholesterol induced phosphorylation of Akt, and increase in the levels of cytosolic and nuclear NF-κB p65, cytosolic NF-κB p50 and cytosolic phosphorylated-IκB-α in PC12 cells. The cholesterol oxidation products also induced a decrease in the levels of Bid and Bcl-2, increase in the levels of p53 and Bax, loss of the mitochondrial transmembrane potential, release of cytochrome c, activation of caspases (-8, -9 and -3), production of reactive oxygen species, depletion of GSH and cell death in both cell lines. Taxifolin, N-acetylcysteine, trolox, Akt inhibitor and Bay11-7085 attenuated the cholesterol oxidation product-induced changes in the apoptosis-related protein levels, activation of the Akt and NF-κB, reactive oxygen species production, GSH depletion and cell death. These results show that taxifolin may reduce the cholesterol oxidation product-induced neuronal apoptosis by suppressing the Akt and NF-κB activation-mediated cell death. The suppressive effect appears to be attributed to the inhibition of reactive oxygen species production and GSH depletion.

Rotundarpene inhibits TNF-α-induced activation of the Akt, mTOR, and NF-κB pathways, and the JNK and p38 associated with production of reactive oxygen species.

Ilex Rotunda Thunb has been shown to have anti-inflammatory and antioxidant effects. In human keratinocytes, we investigated the effect of rotundarpene (4-caffeoyl-3-methyl-but-2-ene-1,4-diol) on the TNF-α-stimulated production of inflammatory mediators in relation to the Akt, mTOR, and NF-κB pathways, and the JNK and p38-MAPK. Rotundarpene, Akt inhibitor, Bay 11-7085, rapamycin, and N-acetylcysteine inhibited the TNF-α-stimulated production of cytokines and chemokines, increase in the levels of p-Akt and mTOR, activation of NF-κB, and production of reactive oxygen species in keratinocytes. TNF-α treatment induced phosphorylation of the JNK and p38-MAPK. Inhibitors of the c-JNK (SP600125) and p38-MAPK (SB203580) reduced the TNF-α-induced production of inflammatory mediators, binding of NF-κB to DNA, and activation of the JNK and p38-MAPK in keratinocytes. The results show that rotundarpene may reduce the TNF-α-stimulated inflammatory mediator production by suppressing the reactive oxygen species-dependent activation of the Akt, mTOR, and NF-κB pathways, and activation of the JNK and p38-MAPK in human keratinocytes. Additionally, rotundarpene appears to attenuate the Akt, mTOR, and NF-κB pathways and the JNK and p38-MAPK-mediated inflammatory skin diseases.

Variability in glycated albumin levels predicts the progression of diabetic nephropathy.

AIM: The present study was performed to assess variability in glycated albumin (GA) using a coefficient of variation (CV) to predict the progression of diabetic nephropathy in type 2 diabetic patients, independently of HbA1c and other conventional risk factors. METHODS: The present study consecutively enrolled 369 patients with type 2 diabetes mellitus from outpatient clinic. During the follow-up period, GA and HbA1c levels were measured repeatedly (≥5 times), and the CV of GA (GA-CV) was calculated for each patient. The patients were divided into two subgroups: Group 1, a MEAN-HbA1c value <7.2% (55mmol/mol); Group 2, a MEAN-HbA1c value ≥7.2% (55mmol/mol). The primary outcome was the renal composite outcome (RCO), which was based on the progression rates of chronic kidney disease and albuminuria and renal death. RESULTS: The median follow-up period was 33months. The RCO was developed in 109 patients (29.5%). In Group 1, the third highest and highest quartile groups for GA-CV had higher cumulative incidences of the RCO than those of the lowest quartile group (Q4 vs. Q1: HR=5.43, P=0.007, Q3 vs. Q1: HR=5.16, P=0.009). After adjusting for HbA1c levels and other risk factors, the GA-CV remained significantly associated with the development of the RCO. However, Group 2 did not exhibit any significant differences in terms of the cumulative incidence of the RCO among the four GA-CV quartile groups. CONCLUSIONS: The present findings suggest that variability in GA may be a better predictor of the progression of diabetic nephropathy in type 2 diabetic patients regardless of HbA1c.

Apocynin inhibits Toll-like receptor-4-mediated activation of NF-κB by suppressing the Akt and mTOR pathways.

Microbial product lipopolysaccharide has been shown to be involved in the pathogenesis of inflammatory skin diseases. Apocynin has demonstrated to have an anti-inflammatory effect. However, the effect of apocynin on the Toll-like receptor-4-dependent activation of Akt, mammalian target of rapamycin (mTOR), and nuclear factor (NF)-κB pathway, which is involved in productions of inflammatory mediators in keratinocytes, has not been studied. Using human keratinocytes, we investigated the effect of apocynin on the inflammatory mediator production in relation to the Toll-like receptor-4-mediated-Akt/mTOR and NF-κB pathways, which regulates the transcription genes involved in immune and inflammatory responses. Apocynin, Akt inhibitor SH-5, Bay 11-7085 and N-acetylcysteine each attenuated the lipopolysaccharide-induced production of cytokines, PGE2, and chemokines, changes in the levels of Toll-like receptor-4, p-Akt, mTOR, and NF-κB, and production of reactive oxygen species in keratinocytes. The results show that apocynin appears to attenuate the lipopolysaccharide-stimulated production of inflammatory mediators in keratinocytes by suppressing the Toll-like receptor-4-mediated activation of the Akt, mTOR, and NF-κB pathways. The effect of apocynin appears to be attributed to its inhibitory effect on the production of reactive oxygen species. Apocynin appears to attenuate the microbial product-mediated inflammatory skin diseases.

Apigenin Reduces Proteasome Inhibition-Induced Neuronal Apoptosis by Suppressing the Cell Death Process.

Impairment of proteasomal function has been shown to be implicated in neuronal cell degeneration. The compounds which have antioxidant and anti-inflammatory abilities appear to provide a neuroprotective effect. Flavone apigenin is known to exhibits antioxidant and anti-inflammatory effects. Nevertheless, the effect of apigenin on the proteasome inhibition-induced neuronal apoptosis has not been studied. Therefore, we assessed the effect of apigenin on the proteasome inhibition-induced apoptotic neuronal cell death using differentiated PC12 cells and human neuroblastoma SH-SY5Y cells. Apigenin attenuated the proteasome inhibitors (MG132 and MG115)-induced decrease in the levels of Bid and Bcl-2, increase in the levels of Bax and p53, loss of the mitochondrial transmembrane potential, release of cytochrome c, activation of caspases (-8, -9 and -3), cleavage of PARP-1 and cell death in both cell lines. Apigenin attenuated the production of reactive oxygen species, the depletion and oxidation of glutathione, the formations of malondialdehyde and carbonyls in cell lines treated with proteasome inhibitors. The results show that apigenin appears to attenuate the proteasome inhibitor-induced apoptosis in differentiated PC12 cells and SH-SY5Y cells by suppressing the activation of the mitochondrial pathway, and of the caspase-8- and Bid-dependent pathways. The inhibitory effect of apigenin on the proteasome inhibitor-induced apoptosis appears to be attributed to the suppressive effect on the production of reactive oxygen species, the depletion and oxidation of glutathione and the formations of malondialdehyde and carbonyls.

Lamotrigine Attenuates Proteasome Inhibition-Induced Apoptosis by Suppressing the Activation of the Mitochondrial Pathway and the Caspase-8- and Bid-Dependent Pathways.

Proteasome impairment has been shown to be involved in neuronal degeneration. Antiepileptic lamotrigine has been demonstrated to have a neuroprotective effect. However, the effect of lamotrigine on the proteasome inhibition-induced neuronal cell death has not been studied. Therefore, we assessed the effect of lamotrigine on the proteasome inhibition-induced neuronal cell apoptosis in relation to cell death process using differentiated PC12 cells and SH-SY5Y cells. The proteasome inhibitors MG132 and MG115 induced a decrease in the levels of Bid and Bcl-2 proteins, an increase in the levels of Bax and p53, loss of the mitochondrial transmembrane potential, cytochrome c release and activation of caspases (-8, -9 and -3). The addition of lamotrigine reduced the proteasome inhibitor-induced changes in the apoptosis-related protein levels, production of reactive oxygen species, depletion and oxidation of glutathione (GSH), and cell death in both cell lines. Lamotrigine and N-acetylcysteine alone did not affect the levels of 26S proteasome and activity of 20S proteasome. MG132 did not alter the levels of 26S proteasome but decreased activity of 20S proteasome. Lamotrigine and N-acetylcysteine attenuated MG132-induced decrease in the activity of 20S proteasome. The results show that lamotrigine appears to suppress the proteasome inhibitor-induced apoptosis in PC12 cells by suppressing the activation of the mitochondrial pathway and the caspase-8- and Bid-dependent pathways. The suppressive effect of lamotrigine appears to be associated with its inhibitory effect on the production of reactive oxygen species, the depletion and oxidation of GSH and the activity reduction of 20S proteasome.

Brefeldin A reduces tumor necrosis factor-α-stimulated production of inflammatory mediators by suppressing the Akt, mTOR, and NF-κB pathways in human keratinocytes.

Keratinocytes may play an important role in the pathogenesis of inflammatory skin diseases. Brefeldin A has been shown to attenuate the production and secretion of chemical mediators involved in inflammation and immune responses. However, the effect of brefeldin A on the TNF-α-stimulated production of inflammatory mediators in keratinocytes has not been studied. We investigated the effect of brefeldin A on the TNF-α-stimulated production of inflammatory mediators using HaCaT cells and primary keratinocytes in relation to the Akt, mTOR, and NF-κB pathways, which regulates the transcription genes involved in immune and inflammatory responses. Brefeldin A, Akt inhibitor, Bay 11-7085 (an inhibitor of NF-κB activation), and rapamycin (mTOR inhibitor) inhibited the TNF-α-stimulated productions of inflammatory mediators, and activations of Akt, mTOR, and NF-κB in keratinocytes. The results show that brefeldin A appears to attenuate TNF-α-stimulated inflammatory mediator production in keratinocytes by suppressing the activation of the Akt, mTOR, and NF-κB pathways.

[Endoscopic Resection of Sporadic Non-ampullary Duodenal Neoplasms: A Single Center Study].

BACKGROUND/AIMS: Sporadic non-ampullary duodenal neoplasms are rare and optimal treatment for these lesions remains undefined. Endoscopic resection of duodenal neoplasms is widely used recently and it is an alternative treatment strategy to surgical excision. This study aimed to evaluate the safety and efficacy of endoscopic resection of duodenal neoplasms and to determine its outcomes. METHODS: Patients who underwent endoscopic resection for non-ampullary duodenal neoplasms between January 2005 and December 2014 were analyzed retrospectively. Data including size, morphology, histology, location and endoscopic procedural technique were reviewed. The main outcome measurements were success rate, complication, recurrence and follow-up assessments. RESULTS: The study included 33 patients with duodenal neoplasms. The mean size of resected lesion was 8.58 mm. The results of histologic examination were as follows: 23 (69.7%) adenomas, 2 (6.1%) adenocarcinoma, 3 (9.1%) Brunner's gland tumor and 3 (9.1%) neuroendocrine tumor. Tubular adenoma was the most common type (63.6%) of non-ampullary duodenal neoplasms. Eighteen (54.5%) lesions were found in the second portion of the duodenum, and 10 (30.3%) lesions on bulb and 3 (9.1%) lesions on superior duodenal angle. Of the 33 cases, 32 (97.0%) were managed by endoscopic mucosal resection technique during a single session and one case was managed by endoscopic submucosal dissection (ESD). One episode of perforation occurred after ESD. During a median follow-up period of 5.76 months, recurrence was observed in only one case of in a patient with tubular adenoma. CONCLUSIONS: Endoscopic resection of duodenal neoplasm is a safe and effective treatment modality that can replace surgical resection in many cases. Careful endoscopic follow-up is essential to manage recurrence or residual lesions.