Radiologic response to transcatheter hepatic arterial chemoembolization and clinical outcomes in patients with hepatocellular carcinoma.

BACKGROUND & AIMS: The current study analysed the association between radiologic tumour response and survival times of patients with hepatocellular carcinoma (HCC) who were treated with transcatheter hepatic arterial chemoembolization (TACE). METHODS: Among 493 consecutive patients presenting to our institution between July 2002 and June 2010 with radiologically (n = 398) or histologically (n = 95) confirmed HCC, 368 patients who met inclusion criteria, underwent TACE and had confirmed survival data were retrospectively reviewed. The radiologic response was assessed using RECIST 1.1, EASL and mRECIST criteria at 1 month after the initial TACE. RESULTS: By univariate analysis, higher Child-Turcotte-Pugh (CTP) score, bilobar and multifocal distribution of tumours, larger tumour size (>5 cm), higher serum alpha-foetoprotein (AFP) level (>200 ng/ml), no subsequent radiofrequency ablation, advanced ECOG, UNOS and BCLC staging, absence of complete necrosis and non-responder (SD or PD) in RECIST 1.1, EASL and mRECIST response assessment were significantly associated with shorter overall survival times. By Cox proportional hazards model, advanced age, presence of ascites, higher MELD score, advanced BCLC staging, absence of complete necrosis and non-responder by RECIST 1.1, EASL and mRECIST criteria were independent and significant prognosticators for overall survival times in patients with HCC who underwent TACE. By time-dependent ROC curve analysis, mRECIST response criteria showed greatest accuracy in predicting survival (AUROC = 0.8676), followed by EASL (AUROC = 0.8471) and RECIST 1.1 (AUROC = 0.7986). CONCLUSION: mRECIST and EASL criteria for assessing radiologic response 1 month after initial TACE more consistently predict the differences in overall survival between responders and non-responders than conventional RECIST 1.1 criteria.

Polycyclic aromatic hydrocarbons (PAHs) in starfish body and bottom sediments in Mohang Harbor (Taean), South Korea.

The concentrations of 27 polycyclic aromatic hydrocarbons (PAHs) were determined in bottom sediments and starfish from Mohang Harbor (MH) in Taean peninsula, South Korea. In December 2007, crude oil washed ashore from the M/V Hebei Spirit and was subsequently cleaned up within a few months of the incident. The ecological risk, bioaccumulation factor (BAF), and composition of the 27 PAHs were examined. The PAH concentrations in the bottom sediment ranged from 24 to 366 µg/kg dried weight, and the ecological risk was determined as minimal (mERL-Q < 1). Total PAH concentrations in Asterina pectinifera (inside seawall) and Asterias amurensis (outside seawall) were 1,226 and 1,477 µg/kg dry weight (d.w.), respectively. The total BAFs (∑BAF) for A. amurensis was 3.8 times higher than that of A. pectinifera, and the PAH concentrations of 5-6 log K OW were highest in the two starfish species. Further, PAH fingerprint analysis (nine alkyl-substituted PAHs fraction, low molecular weight (LMW)/high molecular weight (HMW), Phe/Ant, and Flu/Pyr), and principal component analysis (PCA) based on three crude oil samples from the M/V Hebei Spirit showed no remaining influence of crude oil.

Applying new regional background concentration criteria to assess heavy metal contamination in deep-sea sediments at an ocean dumping site, Republic of Korea.

It is crucial to establish appropriate background concentrations to discern heavy metal pollution in the marine environment. In this study, we analyzed heavy metals in deep-sea sediment cores to determine regional background concentrations at the East-Sea Byeong Ocean dumping site. The vertical profiles of heavy metals were categorized into three groups based on their contamination characteristics, and regional background levels for 12 metals were determined using pre-1900 averages. The enrichment factor, contamination factor, and pollution load index, calculated using regional background concentrations, indicated significant contamination by Cr, Co, Cu, Zn, Cd, Hg, and Pb during the ocean dumping period. These results differ from those obtained using global average concentrations. This underscores the importance of considering regional characteristics to minimize the risk of misinterpreting anthropogenic impacts. The approach based on local information is considered useful when sediment quality guidelines are absent or inapplicable.

Spatiotemporal variation of sterols in sediment as markers of primary production and ocean sewage dumping in the southwestern East Sea (Japan Sea).

The sedimentation of organic carbon in the Ulleung Basin, in the southwestern East Sea (Japan Sea) was investigated using radiocarbon and sterols. The accumulation rates of organic carbon and the contents of brassicasterol and dinosterol were higher on the slope than in the central basin, reflecting the surface water productivity, whereas cholesterol showed similar or higher contents in the central basin. The coprostanol concentration in surface sediments reflected the dispersion of sewage dumped in this region. The vertical distribution showed that the coprostanol concentration was the highest in the top 5-cm layer near the Korea Strait, close to one of the two dumping sites. A high coprostanol concentration was also found near the coast further north, where the content peaked at ∼10 cm depth. The vertical distribution of coprostanol helped to estimate the sediment accumulation rate at sites where radiocarbon gradient was too small or the values were too variable.

Fabrication and characterization of glucose-oxidase-trehalase electrode based on nanomaterial-coated carbon paper.

Multienzyme systems are essential for utilizing di-, oligo-, and polysaccharides as fuels in enzymatic fuel cells effectively. However, the transfer of electrons generated by one enzymatic reaction in a multienzyme cascade at the electrode may be impeded by other enzymes, potentially hindering the overall efficiency. In this study, carbon paper was first modified by incorporating single-walled carbon nanotubes (SWCNTs) and gold nanoparticles (AuNPs) sequentially. Subsequently, glucose oxidase (GOx) and a trehalase-gelatin mixture were immobilized separately on the nanostructured carbon paper via layer-by-layer adsorption to mitigate the electron transfer hindrance caused by trehalase. The anode was first fabricated by immobilizing GOx and trehalase on the modified carbon paper, and the cathode was then fabricated by immobilizing bilirubin oxidase on the nanostructured electrode. The SWCNTs and AuNPs were distributed adequately on the electrode surface, which improved the electrode performance, as demonstrated by electrochemical and morphological analyses. An enzymatic fuel cell was assembled and tested using trehalose as the fuel, and a maximum power density of 23 µW cm-2 was obtained at a discharge current density of 60 µA cm-2. The anode exhibited remarkable reusability and stability.

Heavy metal characterization of land-based waste dumped at three ocean dumping sites in the Republic of Korea.

From 1991 to 2021, 16 categories of land-based waste, totaling 131,400,000 m3, were dumped at three sites in Korea. The concentration of heavy metals varied by waste type, with organic sludge showing higher levels than liquid waste. While wastewater treatment sludge was the most commonly discarded waste, the quantity and types of waste disposed of varied by site. Before the 2015 ban on ocean dumping, 62,330 tons of heavy metals were introduced, including zinc, copper, chromium, lead, arsenic, cadmium, and mercury in descending order of frequency. In each heavy metal category, the portion of land-based waste varied by dumping site. Compared to heavy metals from atmospheric deposition, anthropogenic heavy metal input from dumping was up to 141 times higher for copper. This study serves as a reference for estimating the impact of pollutants from dumped waste.

Long-term effects of chromium from red mud (bauxite residue) ocean dumping on the benthic environment in South Korea.

Between 1999 and 2009, 344,000 m3 of red mud was released into the red mud dumping zone in the East Sea-Byeong ocean dumping site in South Korea. This study aimed to assess the impacts before and after the 2010 red mud dumping ban. We quantified total Cr concentrations by depth from core sediment samples at the red mud dumping station and evaluated benthic communities in 2004, 2009, 2012, 2017, and 2019. At the dumping station DB-085, the Cr content in the upper layer (0-10 cm) exceeded the effect range median criteria in all study years and decreased with time. Geochemical fraction studies using sequential extraction methods from core sediment samples in 2004, 2009, and 2017 showed high ratios of non-residual fractions (anthropogenic inputs), indicating persistent potential long-term risk after the 2010 ban. Additionally, we confirmed that Thyasira tokunagai, an opportunistic and contamination-stress-resistant species, dominated the study station.

Distribution and assessment of heavy metal concentrations in the East Sea-Byeong ocean dumping site, Korea.

Sediment cores were collected from three sites, the Control, Dumping, and Resting sites in the East Sea-Byeong ocean dumping site, Korea, and the enrichment and degree of accumulation of heavy metals were investigated. Further, to assess the level of heavy metal pollution and understand the potential effects of the ocean dumping activities that began in 1993, the results obtained corresponding to the different sampling sites were compared, and various criteria were employed. Indices, including the enrichment factor and the modified contamination degree, demonstrated that the sediments were contaminated with various heavy metals at different contamination levels. The results also indicated a significant upward enrichment in heavy metals, with the uppermost 0-10 cm sediment layer showing relatively high concentrations. Overall, this study confirmed that anthropogenic heavy metal contamination at the study sites, and the implementation of continuous monitoring, alongside the application of proper management tools, is recommended.

Fractionation and risk assessment of metals in sediments of an ocean dumping site.

Sediments of Yellow Sea dumping sites (YSDS) collected in 2015 were analyzed using the European Community Bureau of Reference (BCR) sequential extraction method to assess the contamination and potential risk to the environment. Cr, Ni, Cu, and Zn exhibited the most dominant residual fraction, whereas Cd was mostly in the exchangeable fraction and Pb in the reducible fraction. Cr contains a significant amount of oxidizable fraction in the dumping area due to the dumping of tannery sludge with high concentrations of Cr, mainly in the organic matter-bound form. The global contamination factor (GCF) showed that high non-residual fractions of Cd and Pb contributed considerably to contamination. Nevertheless, modified potential ecological risk index (MRI) suggested low ecological risk for metals in YSDS because of the low total content of Cd and the small mobile fraction of other metals.

Genetic organization of the putative salbostatin biosynthetic gene cluster including the 2-epi-5-epi-valiolone synthase gene in Streptomyces albus ATCC 21838.

The cyclization of sedoheptulose 7-phosphate to 2-epi-5-epi-valiolone, catalyzed by the 2-epi-5-epi-valiolone synthases, is the first committed step in the biosynthesis of C( 7 )N-aminocyclitol-containing natural products, such as validamycin and acarbose. These natural products contain in their structures a valienamine unit, which is important for their biological activity. The same core unit is also found in salbostatin, a related pseudodisaccharide that has strong trehalase inhibitory activity. In silico analysis of the putative biosynthetic gene cluster of salbostatin from Streptomyces albus ATCC 21838 revealed 20 open reading frames, including an acbC homolog gene (salQ), which is believed to be involved in the biosynthesis of salbostatin. The salQ gene was overexpressed in Escherichia coli and the catalytic function of the recombinant protein was confirmed to be a 2-epi-5-epi-valiolone synthase. In addition, SalF, SalL, SalM, SalN, SalO, and SalR were found to be homologous to AcbR, AcbM, AcbL, AcbN, AcbO, and AcbP from the acarbose pathway, respectively, which suggests that the biosynthesis of C(7)N-aminocyclitol moiety of salbostatin may be very similar to that of acarbose.

Thyasira tokunagai as an ecological indicator for the quality of sediment and benthic communities in the East Sea-Byeong, Korea.

The biomass and abundance of molluscan species were identified to evaluate the ecological quality of the surface sediment at the East Sea-Byeong ocean dumping site, Korea. To identify the dominant molluscan species, sediment samples were collected at nine selected stations during five expeditions in 2009, 2012, 2013, 2014, and 2015. In total, 16 molluscan species, including Aplacophora, Gastropoda, Bivalvia, and Scaphopoda, were observed. The bivalve Thyasira tokunagai was the dominant species, accounting for 82.6% of the total abundance of all identified species. This species was also the dominant benthic molluscan in sediments rich in organic matter and with a low manganese content. In addition, environmental variables, including sediment grain size, water depth, total organic carbon, and heavy metals, were found to be critical drivers affecting the spatial distribution of molluscan species.

Chronic adverse effects of oil dispersed sediments on growth, hatching, and reproduction of benthic copepods: Indirect exposure for long-term tests.

Laboratory-scale sediment exposure was conducted as a preliminary study to assess the long-term effects of sediment contaminated with crude oil. For this purpose, indirect exposure using a glass filter crucible was tested and compared with direct exposure by observing several parameters (e.g., mortality, growth, reproduction, hatching, and uptake) in the benthic copepod Tigriopus japonicus. In direct exposure, short-term exposure caused significant damages to the eggs of ovigerous females, and there were difficulties in observing small oil droplets. However, indirect exposure did not induce any mortality during a 96-h exposure in adults. A 10-day exposure was also possible in an indirect exposure method and caused a decrease in reproduction and consequently a reduction in the hatching rate. In fact, the water phase collected from indirect exposure indicated significant polycyclic aromatic hydrocarbon (PAH) concentrations, although only a few components were present. The components of PAHs were similar to water-accommodated fractions (WAFs) of crude oil that are associated with the water-soluble part, but the relative portion of high-molecular-weight of PAHs was higher than WAF. In this approach, exposure tests caused reduction in the uptake rate in copepods even in the 24-h exposure. In conclusion, the biological effects of oil droplets from direct exposure were excluded by using a glass filter in indirect exposures, and several parameters could be derived in the long-term exposure. These results indicate that the indirect method could likely assess the chronic effects of oil-contaminated sediments on individual level parameters for deriving the ultimate effects on the population and community.

Variations in the concentrations of heavy metals through enforcement of a rest-year system and dredged sediment capping at the Yellow Sea-Byung dumping site, Korea.

In 2014, the concentrations of 13 heavy metals in surface sediments from 14 sampling stations were analyzed and compared to samples from previous years to evaluate the remediation effectiveness of the "rest-year" (RY) system and capping with dredged material at the Yellow Sea-Byung dumping site offshore Korea. Since the 2006 introduction of the RY system, annual variations in metal concentrations at stations within the RY zone have gradually decreased over time. Heavy metal concentrations at most stations were lower than sediment quality guidelines, indicating the success of the RY system. Additionally, the effects of capping the contaminated sediment with dredged materials were investigated. The results indicate that dredged materials successfully capped the contaminated sediment within the dredged material dumping area, as the concentrations of Cr and total organic carbon were significantly reduced. We conclude that dredged materials may be used as capping materials for the remediation of contaminated sediments.

Enhancement of the enzymatic digestibility of waste newspaper using Tween.

Methods of increasing the enzymatic digestibility of waste newspaper by adding Tween (TW)-20 and 80 surfactants were investigated. Tween-series surfactants were selected because these surfactants increase cellulase activity during enzymatic hydrolysis and do not inhibit cell growth in downstream fermentation processes. When surfactant was used in a pretreatment, a benefic effect was expected in the enzymatic hydrolysis stage owing to surfactant carry-over from the pretreatment stage immediately upstream of the hydrolysis. However, because it was necessary to wash the pretreated substrate with water to remove inhibitors produced during pretreatment, no added benefit was obtained. When surfactant was used in the pretreatment only, it was found that it had a marked effect on digestibility and that this effect was higher at lower enzyme loadings. Also, TW-80 was found to be more effective than TW-20, and the addition of enzyme and TW-80 to substrate at the beginning of enzyme reaction was found to most effectively increase digestibility. When TW-80 was added into either the pretreatment stage or the hydrolysis stage the digestibilities of untreated sample increased by approx 40%, whereas an increase of only 45% was observed when TW-80 was added to both stages. These results show that the addition of surfactant to either the pretreatment or the enzymatic hydrolysis stage is sufficient to increase digestibility.

Physiological function of insoluble dietary fiber prepared from exploded oak wood (Quercus mongolica).

This study investigated the production of insoluble dietary fiber using exploded and chemically treated oak wood (Quercus mongolica) and the physiological functions of prepared insoluble dietary fiber in laboratory animals. To produce high quality insoluble dietary fiber, the steam explosion treatment was performed at 25 kgf/cm2 pressure for 6 minutes. In the chemical analysis of insoluble dietary fiber, exploded oak wood was pretreated by 1% sodium hydroxide solution. The insoluble dietary fiber contained 7.6% residual lignin and 61.7% of alpha-cellulose. In order to compare the physiological functions of prepared insoluble dietary fiber with those of commercial insoluble dietary fiber, Sprague-Dawley male rats weighing 100 +/- 10 g were randomly assigned to one normal diet and five high cholesterol diets, containing 1% cholesterol. The high cholesterol diet groups were classified as the fiber-free diet (FF group), 5% commercial alpha-cellulose diet group (5C group), 10% commercial alpha-cellulose group (10C group), 5% insoluble dietary fiber group (5M group) and 10% insoluble dietary fiber group (10M group). Food intake, weight gain and food efficiency ratio in high cholesterol groups were significantly higher than those of the normal group, but there were no significant differences among the high cholesterol diet groups. In addition, there were no significant differences in the weights of liver, kidney and small intestine in insoluble dietary fiber-supplemented groups. Cecum weights in all insoluble dietary fiber groups were significantly higher than those of the FF group. There were no significant differences in the activities of the glutamic pyruvic transaminase (GPT) and glutamic oxaloacetic transaminase (GOT) among the insoluble dietary fiber-supplemented groups. In conclusion, the prepared insoluble dietary fiber and the commercially available insoluble fiber showed the same physiological effects. Moreover, the preparation method for the insoluble dietary fiber from the exploded oak wood was successful.

Development of an optimal medium for continuous ferrous iron oxidation by immobilized Acidothiobacillus ferrooxidans cells.

This study was aimed at developing an immobilized bioreactor system in which long-term continuous ferrous iron oxidation can be realized with no formation of jarosite, which causes clogging of support pores and reactor lines. For this purpose, a medium with no jarosite formation was developed first by selecting optimal nitrogen and phosphate sources and their concentrations. Then with the developed medium containing ammonium phosphate instead of ammonium sulfate and potassium phosphate, repeated batch and continuous operations of ferrous iron oxidation by Acidothiobacillus ferrooxidans cells immobilized in a depth filter were successfully performed for an extended period of time. For about 510 h of operation including 450 h of continuous operation at dilution rates of 0.1, 0.2, and 0.3 h(-)(1), no formation of jarosite and thus no clogging of the reactor system were observed. The maximum ferrous iron oxidation rate was as high as 2.6 g/(L.h) at a dilution rate of 0.3 h(-)(1).

Congener-specific accumulation and environmental risk assessment of polybrominated diphenyl ethers in diverse Korean sewage sludge types.

Industrial, domestic wastewater, and livestock sludge samples were collected from 23 wastewater treatment plants in Korea and analyzed for polybrominated diphenyl ethers (PBDEs). The concentrations of Σ19PBDE ranged from 4.01 to 10,400 ng/g dry weight. The average Σ19PBDE concentrations in industrial, domestic wastewater, and livestock sludge were 1,560 ± 3,610, 402 ± 148, and 27.6 ± 50.4 ng/g dry weight, respectively. The composition of PBDEs differed according to the type of sludge. Among the PBDE congeners, BDE 209 was dominant in all sludge samples. After BDE 209, relatively high levels were found for BDE 28 and 47 from industrial sludge, BDE 47 and 99 from domestic wastewater sludge, and BDE 206, 207, and 208 from livestock sludge. Using hierarchical cluster analysis, sludges were divided into three groups according to PBDE congener composition. A risk assessment of PBDEs in sludge used for soil amendment was carried out. Preliminary results indicated that the potential risk of soil exposed to PBDEs in sludge was relatively low.

Improved tolerance of recombinant Escherichia coli to the toxicity of crude glycerol by overexpressing trehalose biosynthetic genes (otsBA) for the production of ß-carotene.

This study aims to investigate whether overexpressing the trehalose biosynthetic gene, otsBA operon, in ß-carotene-producing recombinant Escherichia coli protects cells from toxic impurities in crude glycerol. The concentrations of potassium and methanol in crude glycerol were too low to inhibit cell growth. Cell growth and production in control cell culture were inhibited significantly in the presence of a small amount of crude fatty acids. Peroxides were generated in the presence of crude fatty acids during autoclaving and, thus, the inhibitory effect of crude fatty acids was caused primarily by these peroxides. Engineered cells overexpressing otsBA tolerated crude fatty acids (≤42 wet-g/L), methanol (≤7.5 g/L), and t-BuOOH (≤60 µM) in separate experiments and tolerated up to 60 g/L crude glycerol. These results demonstrate that overexpressing otsBA endowed cells with the capacity to tolerate the toxicity of crude glycerol for direct use.

Nullifying tumor efflux by prolonged endolysosome vesicles: development of low dose anticancer-carbon nanotube drug.

As the majority of side effects of current chemotherapies stems from toxicity due to excessive dosing of anticancer drugs, minimizing the amount of drug while maximizing drug efficacy is essential to increase the life-quality of chemotherapy patients. This study demonstrated that the intracellular delivery of amide linked doxorubicin on carbon nanotube can nullify the efflux of cancer cells by achieving prolonged endolysosome delivery and can induce burst release of doxorubicin in an acidic hydrolase environment and, ultimately, can reduce the amount of anticancer drug by 10-fold compared to conventional effective drug dose. The clearance of accumulated carbon nanotubes in the liver was observed after 4 weeks, and analysis of liver toxicity markers showed no significant changes in GOT and GPT levels and release of pro-inflammatory cytokines across both short- and long-term periods.

Elevated red cell distribution width is associated with advanced fibrosis in NAFLD.

BACKGROUND/AIMS: The red-blood-cell distribution width (RDW) is a newly recognized risk marker in patients with cardiovascular disease, but its role in nonalcoholic fatty liver disease (NAFLD) has not been well defined. The aim of the present study was to determine the association between RDW values and the level of fibrosis in NAFLD according to BARD and FIB-4 scores. METHODS: This study included 24,547 subjects who had been diagnosed with NAFLD based on abdominal ultrasonography and questionnaires about alcohol consumption. The degree of liver fibrosis was determined according to BARD and FIB-4 scores. The association between RDW values and the degree of fibrosis in NAFLD was analyzed retrospectively. RESULTS: After adjusting for age, hemoglobin level, mean corpuscular volume, history of hypertension, history of diabetes, and high-sensitivity C-reactive protein, the RDW values were 12.61±0.41% (mean±SD), 12.70±0.70%, 12.77±0.62%, 12.87±0.82%, and 13.25±0.90% for those with BARD scores of 0, 1, 2, 3, and 4, respectively, and 12.71±0.72%, 12.79±0.66%, and 13.23±1.52% for those with FIB-4 scores of <1.30, 1.31-2.66, and ≥2.67, respectively (P<0.05). The prevalence of advanced fibrosis (BARD score of 24 and FIB-4 score of ≥1.3) increased with the RDW [BARD score: 51.1% in quartile 1 (Q1) vs. 63.6% in Q4; FIB-4 score: 6.9% in Q1 vs. 10.5% in Q4; P<0.001]. After adjustments, the odds ratio of having advanced fibrosis for those in Q4 compared to Q1 were 1.76 (95%CI=1.55-2.00, P<0.001) relative to BARD score and 1.69 (95%CI=1.52-1.98, P<0.001) relative to FIB-4 score. CONCLUSIONS: Elevated RDW is independently associated with advanced fibrosis in NAFLD.