Effect of β-adrenergic receptor agents on cardiac structure and function and whole-body gene expression in Daphnia magna

Propranolol (PRO), a human β-AR (β-adrenergic receptor) antagonist, is considered to result in specific effects in a non-target species, D. magna, based on our previous studies. The present study investigated the effects of β-AR agents, including an antagonist and agonist using pharmacologically relevant endpoints as well as a more holistic gene expression approach to reveal the impacts and potential mode of actions (MOAs) in the model non-target species. Results show that the responses in cardiac endpoints and gene expression in D. magna are partially similar but distinguishable from the observations in different organisms. No effect was observed on heart size growth in PRO and isoprenaline (ISO) exposure. The contraction capacity of the heart was decreased in ISO exposure, and the heart rate was decreased in PRO exposure. Time-series exposures showed different magnitudes of effect on heart rate and gene expression dependent on the type of chemical exposure. Significant enrichment of gene families involved in protein metabolism and biotransformation was observed within the differentially expressed genes, and we also observed differential expression in juvenile hormone-inducible proteins in ISO and PRO exposure, which is suspected of having endocrine disruption potential. Taken together, deviation between the effects of PRO and ISO in D. magna and other organisms suggests dissimilarity in MOAs or attributes of target bio-molecules between species. Additionally, PRO and ISO may act as endocrine disruptors based on the gene expression observation. Results in the present study confirm that it is challenging to predict ecological impact of active pharmaceutical ingredients (APIs) based on the available data acquired through human-focused studies. Furthermore, the present study provided unique data and a case study on the impact of APIs in a non-target organism.

Profiling the decomposition products of perfluorooctane sulfonate (PFOS) irradiated using an electron beam

Perfluorooctane sulfonate (PFOS) has been found in wastewater treatment plants (WWTPs) and in surface water as a result of domestic uses of textiles, electronics, and surfactants. The detection of PFOS in the aqueous environment has been linked to hazardous biological effects including estrogenicity and genotoxicity. To provide an alternative to conventional processes, one of the radical-based advanced oxidation and reduction processes being tested for treatment of refractory compounds in water, involves the use of an electron beam. Therefore, the aims of this study were to investigate the degradation efficiency of PFOS (100mg/L) by electron beam, to evaluate the predicted toxicity of the radiolysis products using the ECOSAR model, and to identify the radiolytic products of PFOS. As a result of using the ECOSAR model, the toxicity levels of by-products after electron beam treatment were reduced by decreasing the carbon-chain number of PFOS. The molecular structures of the radiolytic products were elucidated using authentic standards via liquid chromatography and tandem mass spectrometry, and by the interpretation of MS² fragmentation patterns of each product using liquid chromatography with quadrupole time of-flight mass spectrometry (LC-QTOF-MS). In total, ten radiolytic products were confirmed by LC-MS/MS, HPLC, and IC data matching with commercial standards. The two radiolytic substances produced during irradiation with an electron beam were predicted by LC-QTOF-MS. This study led to an understanding of the role of electron beams in the transformation of parent compounds and to the decomposition products created when an electron beam is applied to treat perfluorinated compounds.

Kidney Transplantation Using Expanded-Criteria Deceased Donors: A Comparison With Ideal Deceased Donors and Non-Expanded-Criteria Deceased Donors

PURPOSE

The use of expanded-criteria deceased-donor (ECD) kidneys must be evaluated within the objective perspective of critical organ shortage and graft function and survival. In this study, we aimed to compare the clinical outcomes of ECD reliance with concurrent use of ideal-criteria deceased donors (IDDs) and non-ECDs in adult renal transplantation.

METHODS

Between February 2000 and December 2015, we analyzed 405 deceased-donor renal transplants, specifically 129 grafts (31.9%) from ECDs, 233 grafts (57.5%) from non-ECDs, and 43 grafts (10.6%) from IDDs. ECDs were classified according to the United Network for Organ Sharing guidelines, while an IDD was defined as a younger person (10-39 years of age) with no medical risk factors who died from a traumatic head injury. Donor and recipient risk factors were separately analyzed and correlated with recipient graft function, and survival was evaluated.

RESULTS

ECDs were older (56.8 ± 6.3 years); showed increased incidence of hypertension, diabetes, and cerebrovascular brain death; and had a higher pre-retrieval serum creatinine level than the other groups. ECD kidney recipients were also older (50.6 ± 9.8 years), had a shorter waiting time (P = .031), and demonstrated a low frequency of re-transplantation (P = .028). Long-term renal function followed longitudinally was lower in ECD kidney recipients until five years after transplantation, while the glomerular filtration rate (GFR) level at 7 and 10 years did not differ significantly among the groups (P = .074 and .262, respectively). There were no significant differences in terms of graft survival (P = .394) or patient survival (P = .737) among the groups.

CONCLUSIONS

Although the long-term renal function followed longitudinally was lower in ECD kidney recipients, the use of renal grafts from ECDs is an acceptable method to resolve the disparity of critical organ shortage. However, the classification of the high-risk group should be updated with consideration given to differences in regional characteristics.

Validation of a biotic ligand model on site-specific copper toxicity to Daphnia magna in the Yeongsan River, Korea

The objective of this study was to determine whether the water effect ratio (WER) or biotic ligand model (BLM) could be applied to efficiently develop water quality criteria (WQC) in Korea. Samples were collected from 12 specific sites along the Yeongsan River (YSR), Korea, including two sewage treatment plants and one estuary lake. A copper toxicity test using Daphnia magna was performed to determine the WER and to compare to the BLM prediction. The results of the WER from YSR samples also indicated significantly different copper toxicities in all sites. The model-based predictions showed that effluent and estuary waters had significantly different properties in regard to their ability to be used to investigate water characteristics and copper toxicity. It was supposed that the slight water characteristics changes, such as pH, DOC, hardness, conductivity, among others, influence copper toxicity, and these variable effects on copper toxicity interacted with the water composition. The 38% prediction was outside of the validation range by a factor of two in all sites, showing a poor predictive ability, especially in STPs and streams adjacent to the estuary, while the measured toxicity was more stable. The samples that ranged from pH 7.3-7.7 generated stable predictions, while other samples, including those with lower and the higher pH values, led to more unstable predictions. The results also showed that the toxicity of Cu in sample waters to D. magna was closely proportional to the amounts of acidity, including the carboxylic and phenolic groups, as well as the DOC concentrations. Consequently, the acceptable prediction of metal toxicity in various water samples needs the site-specific results considering the water characteristics such as pH and DOC properties particularly in STPs and estuary regions.

Comparative sorption isotherms and removal studies for Pb(II) by physical and thermochemical modification of low-cost agro-wastes from Tanzania

Corn and rice husks, agro-wastes available in large quantities in Tanzania, were used to remove Pb²⁺ from aqueous solution. Husks were used in raw form, pyrolyzed form, and chemically modified form. Material characterization was carried out using the BET method, FTIR spectroscopy, SEM, pH_PZC, and cation exchange capacity analysis. Langmuir, Freundlich, Dubinin-Radushkevich (D-R), and Temkin isotherms were used to elucidate Pb²⁺ sorption mechanisms. The surface area and cation exchange capacity (CEC) of untreated and chemically treated biochars were significantly higher than that of raw husks. Sorption data for Pb²⁺ for all biosorbents fit the Freundlich and D-R models well with high R² values. Most of the synthesized biosorbents in this study indicated >90% for Pb²⁺ removal, with the ZnCl₂-treated corn husk biochar sorption capacities ranking highest in all modeling results. Surface morphological features (e.g., micropores and fissures) and acidic and unsaturated functional groups may have significantly contributed to the observed Pb²⁺ removal efficiencies.

Mode of action characterization for adverse effect of propranolol in Daphnia magna based on behavior and physiology monitoring and metabolite profiling

Studies are underway to gather information about the mode of action (MOA) of emerging pollutants that could guide practical environmental decision making. Previously, we showed that propranolol, an active pharmaceutical ingredient, had adverse effects on Daphnia magna that were similar to its pharmaceutical action. In order to characterize the mode of action of propranolol in D. magna, which is suspected to be organ-specific pharmaceutical action or baseline toxicity, we performed time-series monitoring of behavior along with heart rate measurements and nuclear magnetic resonance (NMR) based metabolite profiling. Principle component analysis (PCA) and hierarchical clustering were used to categorize the mode of action of propranolol among 5 chemicals with different modes of action. The findings showed that the mode of action of propranolol in D. magna is organ-specific and vastly different from those of narcotics, even though metabolite regulation is similar between narcotic and non-narcotic candidates. The method applied in this study seems applicable to rapid characterization of the MOA of other cardiovascular pharmaceutical ingredients.

Genetic parameters of carcass and meat quality traits in different muscles (longissimus dorsi and semimembranosus) of Hanwoo (Korean cattle)

We estimated heritability () and genetic and phenotypic correlations for carcass and meat quality traits of longissimus dorsi (LD) and semimembranosus (SM) muscles in 30-mo-old Hanwoo steers. Variance and covariance components were estimated using REML procedures under univariate and bivariate models. The mean carcass weight (CWT), eye muscle area (EMA), back fat thickness (BFT), and marbling score (MS) were 428.20 ± 46.30 kg, 87.38 ± 8.54 cm2, 13.00 ± 5.14 mm, and 5.21 ± 1.56, respectively. The mean CIE reflectance of meat lightness (L*), redness (a*), and yellowness (b*) were 40.01 ± 2.73, 22.37 ± 2.18, and 10.35 ± 1.46, respectively, in LD muscles and 36.33 ± 2.44, 22.91 ± 2.43, and 10.25 ± 1.65, respectively, in SM muscles. The mean Warner-Bratzler shear force (WBSF), intramuscular fat content (IMF), water-holding capacity (WHC), and protein and ash content in LD and SM muscles were 3.84 ± 0.96 and 6.52 ± 1.21 kg, 15.91 ± 4.39 and 5.10 ± 1.94%, 62.07 ± 3.38 and 71.61 ± 2.06%, 20.01 ± 1.39 and 21.34 ± 0.89%, and 0.80 ± 0.10 and 0.93 ± 0.07, respectively. The estimates of CWT, EMA, BFT, and MS were 0.51 ± 0.13, 0.45 ± 0.13, 0.29 ± 0.09, and 0.22 ± 0.08, respectively. The estimates were moderate for meat quality traits and were 0.37 ± 0.12, 0.40 ± 0.12, 0.33 ± 0.10, 0.33 ± 0.10, 0.30 ± 0.11, and 0.24 ± 0.09 for L*, WBSF, IMF, WHC, and protein and ash content, respectively, in LD muscle; estimates from SM muscle were comparatively low (0.08 ± 0.06 to 0.25 ± 0.09). Estimates of for a* and b* were also low (0.08 ± 0.06 to 0.13 ± 0.07). Carcass weight had a moderate, positive genetic correlation with EMA (0.60 ± 0.13) and a weak correlation with MS and BFT. The genetic correlations among the 3 colorimeter variants were strong and positive within and between muscles. Intramuscular fat content had moderate to strong and negative genetic correlations with WBSF (-0.49 ± 0.18), WHC (-0.99 ± 0.01), and protein (-0.93 ± 0.04) and ash content (-0.98 ± 0.06) in LD muscle, whereas the associations were less pronounced in SM muscle. In general, CWT and EMA had low genetic and phenotypic correlations with meat quality traits, which suggests that the traits are independent and have distinct genetic contributions in each muscle. Conversely, with few exceptions, meat quality traits had genetic and phenotypic correlations with MS and BFT. In conclusion, the estimated genetic parameters for carcass and meat quality traits could be used for genetic evaluation and breeding programs in Korean Hanwoo cattle populations.

Multigenerational Effects of the Antibiotic Tetracycline on Transcriptional Responses of Daphnia magna and Its Relationship to Higher Levels of Biological Organizations

Given the risk of environmental pollution by pharmaceutical compounds and the effects of these compounds on exposed ecosystems, ecologically relevant and realistic assessments are required. However, many studies have been mostly focused on individual responses in a single generation exposed to one-effect concentrations. Here, transcriptional responses of the crustacean Daphnia magna to the antibiotic tetracycline across multiple generations and effect concentrations were investigated. The results demonstrated that tetracycline induced different transcriptional responses of daphnids that were dependent on dose and generation. For example, reproduction-related expressed sequence tags (ESTs), including vitellogenin, were distinctly related to the dose-dependent tetracycline exposure, whereas multigenerational exposure induced significant change of molting-related ESTs such as cuticle protein. A total of 65 ESTs were shared in all contrasts, suggesting a conserved mechanism of tetracycline toxicity regardless of exposure concentration or time. Most of them were associated with general stress responses including translation, protein and carbohydrate metabolism, and oxidative phosphorylation. In addition, effects across the dose-response curve showed higher correlative connections among transcriptional, physiological, and individual responses than multigenerational effects. In the multigenerational exposure, the connectivity between adjacent generations decreased with increasing generation number. The results clearly highlight that exposure concentration and time trigger different mechanisms and functions, providing further evidence that multigenerational and dose-response effects cannot be neglected in environmental risk assessment.

Developing and applying a site-specific multimedia fate model to address ecological risk of oxytetracycline discharged with aquaculture effluent in coastal waters off Jangheung, Korea

The overuse of oxytetracycline (OTC) in aquaculture has become a problem because of its chronic toxic effects on marine ecosystems. The present study assessed the ecological risk of OTC in the coastal waters near the Jangheung Flatfish Farm using a site-specific multimedia fate model to analyze exposure. Before the model was applied, its performance was validated by comparing it with field data. The coastal waters in the testbed were sampled and analyzed using liquid chromatography-tandem mass spectrometry (LC-MS/MS) followed by solid-phase extraction (SPE). The concentrations of OTC measured varied from 7.05 to 95.39ng/L. The results of validating the models showed that the site-specific multimedia fate model performed better (root mean square error (RMSE): 24.217, index of agreement (IOA): 0.739) than conventional fugacity approaches. This result demonstrated the utility of this model in supporting effective future management of aquaculture effluent. The results of probabilistic risk assessment indicated that OTC from aquaculture effluent did not cause adverse effects, even in a maximum-use scenario.

Multigenerational effect of perfluorooctane sulfonate (PFOS) on the individual fitness and population growth of Daphnia magna

We investigated the multigenerational effect of PFOS to individual fitness (e.g., body weight, acetylcholinesterase and glutathione S-transferase) and population growth (e.g., offspring number and time to first brood) of Daphnia magna during continuous and discontinuous exposures. The intrinsic rate of population growth was also calculated. In the continuous exposure, population growth-related adverse effects were detected during all test periods, and the adverse effect tended to be weaker in later generations. On the other hand, individual fitness-related adverse effects were observed from F1 not in F0 and deteriorated as the generation number increased. These results imply that individual fitness worsens although the population growth is restored in later generations. Upon discontinuous exposure, a few but significant adverse effects were observed during the non-exposure period and highest effects were detected during the re-exposure period. This encourages the study of different exposure scenarios, which may result in unexpected and higher PFOS toxicity. Consequently, this study confirms adverse effects of PFOS to Daphnia magna in multigenerational period and supports reasons for studies linking individual fitness changes to population dynamics and covering diverse exposure scenarios to evaluate the risk of PFOS in a water environment.

Bioaccumulation and biotransformation of the beta-blocker propranolol in multigenerational exposure to Daphnia magna

Multigenerational bioaccumulation and biotransformation activity and short-term kinetics (e.g., uptake and depuration) of propranolol in Daphnia magna were investigated at environmental concentration. The body burden and the major metabolite, desisopropyl propranolol (DIP), of propranolol were quantified using LC-MS/MS at the end of each generation after exposure for 11 generations. The accumulation of propranolol in D. magna at an environmental concentration of 0.2 μg/L was not much different between the parent (F0) and the eleventh filial (F10) generation. However, at 28 μg/L, its accumulation was 1.6 times higher-up to 18.9 μg/g-in the F10 generation relative to the F0. In contrast to propranolol, DIP intensity gradually increased from F0 to F10 at 0.2 μg/L, reflecting an increase in detoxification load and biotransformation performance; no increasing trend was observed at 28 μg/L. The bioaccumulation factor (BAF) showed higher values with a lower concentration and longer period of exposure. The average values of the BAF for 21 days of long-term exposure in successive 11 generations were 440.4 ± 119.7 and 1026.5 ± 208.6 L/kg for 28 μg/L and 0.2 μg/L, respectively. These are comparable to the BAF of 192 for the short-term 72-h exposure at 28 μg/L in the parent generation. It is also recommended that future studies for pharmaceutical ingredients be conducted on drug-drug interaction and structural characteristics on the prediction of biotransformation activity and bioaccumulation rate.

Reduction and persulfate oxidation of nitro explosives in contaminated soils using Fe-bearing materials

The oxidative and reductive transformation of nitro explosives in contaminated soils with Fe-bearing materials and persulfate (S2O8(2-)) was examined via batch experiments. Zero-valent cast iron [Fe(0)], steel dust from a steel manufacturing plant, and FeS rapidly reduced 2,4,6-trinitrotoluene (TNT) and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) in soil under anaerobic conditions as long as a sufficient amount of water was present. The Fe-bearing materials also effectively activated persulfate to enhance the oxidative transformation of TNT and RDX in soil-water systems. Kinetically, reductive and oxidative transformations removed more than 90% of the explosives from a soil-water system within 5 h under the given conditions. Pseudo-first-order rates in the range of 0.7-23.4 h(-1) were observed. By increasing the concentration of persulfate or Fe-bearing materials, the oxidative transformation could be promoted. Treated soils via redox reactions using the Fe-bearing materials did not show significant toxicity, except for the case of TNT-contaminated soils oxidized by FeS-assisted persulfate. Considering the kinetics of explosive degradation and the toxicity of treated wastewaters and soils, Fe(0) or steel dust-assisted persulfate oxidation may be a safe option as an ex situ remediation process for the treatment of explosive-contaminated soils.

Application of toxicity identification evaluation procedure to toxic industrial effluent in South Korea

Toxicity identification evaluation (TIE) was applied to the effluent from a pharmaceutical industrial complex, following the US EPA TIE guidelines. The whole effluent toxicity (WET) test found toxicity greater than 16toxic units (TU) in the effluent. Dissolved non-polar organic compounds were identified as the major contributor to the observed toxicity in the TIE manipulations in phases I and II. Among the 48 organic compounds identified, three compounds (i.e., acetophenone, benzoimide, and benzothiazole) were related to the pharmaceutical production procedure; however, no contribution to toxicity was predicted in the compounds. The results of the ECOSAR model, which predicts toxicity, indicated that the alkane compounds caused significant toxicity in the effluent. The toxicity test and heavy metal analysis, which used IC and ICP/MS, identified that particulate and heavy metals, such as Cu and Zn, contributed to the remaining toxicity, except dissolved organics. The results showed the applicability of the TIE method for predicting regional effluents produced by the industrial pharmaceutical complex in this study. Although the location was assumed to be affected by discharge of pharmaceutical related compounds in the river, no correlations were observed in the study. Based on the results, advanced treatment processes, such as activated carbon adsorption, are recommended for the wastewater treatment process in this location.

Citrate coated silver nanoparticles change heavy metal toxicities and bioaccumulation of Daphnia magna

Citrate-coated AgNPs (c-AgNPs) have negatively charged surfaces and their surface interactions with heavy metals can affect metal toxicity in aquatic environments. This study used Daphnia magna to compare the acute toxicities and bioaccumulation of As(V), Cd, and Cu when they interact with c-AgNPs. The 24-h acute toxicities of As(V) and Cu were not affected by the addition of c-AgNPs, while bioaccumulation significantly decreased in the presence of c-AgNPs. In contrast, both the 24-h acute toxicity and bioaccumulation of Cd increased in the presence of c-AgNPs. These toxicity and bioaccumulation trends can be attributed to the interactions between the AgNP surface and the heavy metals. As(V) and c-AgNPs compete by negative charge, decreasing As(V) toxicity. Copper adheres readily to c-AgNP citrate, decreasing Cu bioavailability, and thus reducing Cu toxicity and bioaccumulation. Citrate complexes with divalent cations such as Ca and Mg reduce the competition between divalent cations and Cd on biotic ligand, increasing toxicity and bioaccumulation of Cd. This study shows that surface properties determine the effect of c-AgNPs on heavy metal toxicities and bioaccumulations; hence, further studies on the effect of nanoparticle by it surface properties are warranted.

Sorption and toxicity reduction of pharmaceutically active compounds and endocrine disrupting chemicals in the presence of colloidal humic acid

This study investigated the toxicity changes and sorption of pharmaceuticals and endocrine disrupters in the presence of humic acid (HA). For the sorption experiment, a dead end filtration (DEF) system was used to separate bound and free-form target compounds. An algae growth inhibition test and E-screen assay were conducted to estimate the toxic effect of pharmaceutically active compounds (PhACs) and endocrine disrupting chemicals (EDCs), respectively. The permeate concentration was confirmed using liquid chromatography-mass spectrometry. In the sorption test, we observed significant sorption of PhACs and EDCs on colloidal HA, except for sulfamethoxazole (SMX). The values of log KCOC derived from DEF determinations ranged from 4.40 to 5.03. The removal efficiency varied with the HA concentration and the target chemical properties. Tetracycline and 4-octylphenol showed the highest sorption or removal efficiency (≈50%), even at 5 mg C/L HA. The algal growth inhibition of PhACs and the estrogenic effects of EDCs were significantly decreased in proportion to HA concentrations, except for SMX. In addition, the chemical analysis results showed a positive relationship with the bioassay results. Consequently, the sorption of PhACs and EDCs onto colloidal HA should be emphasized in natural environments because it significantly reduces bioavailable concentrations and toxicity to aquatic organisms.

Multi-generational effects of propranolol on Daphnia magna at different environmental concentrations

To evaluate the effects of propranolol on Daphnia magna (D. magna), we employed a multi-generational exposure period for eight generations and an environmentally relevant low concentration with 1.5 ng/L, 0.2 μg/L and 26 μg/L to reflect a realistic exposure scenario. Physiological endpoints were checked, including growth, number of neonates, heart rate, frequency of abdominal appendage movement and malformation rate of neonates. In the results, growth and abdominal appendage movement were affected by environmental concentration during several generations, and the responses showed consistent tendencies of response increase with concentration increase. Heart rate was the only endpoint affected throughout all exposure generations. Inhibitory and acceleratory effects on heart rate, growth and abdominal appendage movement suggest that it is necessary to cover sub-lethal endpoints of non-targeted organisms in eco-toxicity study because the physiological responses were detected at much lower concentrations than the results of traditional toxicity tests, including environmental concentration.

Injury to the blood-testis barrier after low-dose-rate chronic radiation exposure in mice

Exposure to ionising radiation induces male infertility, accompanied by increasing permeability of the blood-testis barrier. However, the effect on male fertility by low-dose-rate chronic radiation has not been investigated. In this study, the effects of low-dose-rate chronic radiation on male mice were investigated by measuring the levels of tight-junction-associated proteins (ZO-1 and occludin-1), Niemann-Pick disease type 2 protein (NPC-2) and antisperm antibody (AsAb) in serum. BALB/c mice were exposed to low-dose-rate radiation (3.49 mGy h(-1)) for total exposures of 0.02 (6 h), 0.17 (2 d) and 1.7 Gy (21 d). Based on histological examination, the diameter and epithelial depth of seminiferous tubules were significantly decreased in 1.7-Gy-irradiated mice. Compared with those of the non-irradiated group, 1.7-Gy-irradiated mice showed significantly decreased ZO-1, occludin-1 and NPC-2 protein levels, accompanied with increased serum AsAb levels. These results suggest potential blood-testis barrier injury and immune infertility in male mice exposed to low-dose-rate chronic radiation.

MacroH2A1 downregulation enhances the stem-like properties of bladder cancer cells by transactivation of Lin28B

The histone variant, macroH2A1, has an important role in embryonic stem cell differentiation and tumor progression in various types of tumors. However, the regulatory roles of macroH2A1 on bladder cancer progression have not been fully elucidated. Here, we show that macroH2A1 knockdown promotes stem-like properties of bladder cancer cells. The knockdown of macroH2A1 in bladder cancer cells increased tumorigenicity, radioresistance, degeneration of reactive oxygen species, increased sphere formation capability and an increase in the proportion of side populations. We found that macroH2A1 is required for the suppression of Lin28B identified as a novel downstream target of macroH2A1 in bladder cancer. Loss of macroH2A1 expression significantly correlated with the elevated levels of Lin28B expression and subsequently inhibited the mature let-7 microRNA expression. Furthermore, the stable overexpression of Lin28B enhances the several phenotypes, including tumorigenicity and sphere-forming ability, which are induced by macroH2A1 depletion. Importantly, Lin28B expression was regulated by macroH2A1-mediated reciprocal binding of p300 and EZH2/SUV39H1. Our results suggest that Lin28B/let-7 pathway is tightly regulated by macroH2A1 and its cofactors, and have a pivotal role in the bladder tumor progression and the regulation of stem-like characteristics of bladder cancer cells.

The effect of C1 bursting fracture on comparative anatomical relationship between the internal carotid artery and the atlas

PURPOSE

To describe the effect of the C1 bursting fracture on the location of the internal carotid artery (ICA) around the atlas.

METHODS

The authors analyzed the morphology of the atlas and the ICA in 15 patients with C1 bursting fracture and compared with control group (77 patients) without any pathology. All patients were evaluated with CT angiography for the anatomical assessment. The laterality of the ICA, the distances of the ICA from the midline, anterior tubercle, and ventral surface of the C1 lateral mass were compared between two groups. The distance between the lateral margin of the longus capitis muscle and the inner edge of the transverse foramen was also measured.

RESULTS

Medially located ICA was more common in the C1 bursting fracture group than control group (76.7 vs 42.8 %). There were no significant differences between 2 groups for the distance from the midline, anterior tubercle, and ventral surface of the C1 lateral mass, respectively. The distance of the longus capitis muscle to transverse foramen was 2.52 ± 2.09 and 4.15 ± 3.09 mm in each group, and there was statistically significant difference (p < 0.01).

CONCLUSIONS

Lateral displacement of the bony structure of C1 bursting fracture changes the relative location of the ICA medially, which increase the injury risk during the bicortical C1 screw insertion. These data suggest that CT angiography or enhanced CT scans can give critical information to choose the ideal fixation technique and the proper trajectory of the screws for C1 bursting fracture.

Aqueous and dietary bioaccumulation of antibiotic tetracycline in D. magna and its multigenerational transfer

The potential bioaccumulation and distribution of antibiotics in non-target organisms have been inadequately studied in spite of their widespread occurrence in aquatic systems. We investigated the ability of tetracycline to bioaccumulate through aqueous and dietary routes in an aquatic organism, the freshwater crustacean Daphnia magna. D. magna was exposed to algal food (Pseudokirchneriella subcapitata) contaminated with tetracycline for dietary uptake. Tetracycline was transferred to D. magna more through aqueous uptake than through dietary uptake. The uptake rate constant of tetracycline for D. magna was kin,water=0.33±0.045 via the aqueous route and kin,food=0.16±0.012 via the dietary route for 1.0mgL(-1) tetracycline. Bioconcentration factors of 4.40±0.91Lkg(-1) and 3.66±0.50Lkg(-1) for 0.1 and 1.0mgL(-1) tetracycline were found for D. magna. The biomagnification factor of 0.19±0.04 indicates that magnification of tetracycline through the food web will not occur. The change in the internal concentration of the target compound was also studied for multigenerational (F1-F4) exposure. The internal concentration in D. magna showed a decreasing trend with increasing generations except for the parent generation. The bioaccumulation tendency showed a biphasic change in multigenerational exposure.

Relationship between trans-generational effects of tetracycline on Daphnia magna at the physiological and whole organism level

The effects of pharmaceuticals have been underestimated during single generation exposure. Therefore, in this study, we investigated toxic responses at the physiological and whole organism level in tetracycline-exposed Daphnia magna over four consecutive generational lifecycles. The results showed that tetracycline affected energy-related physiological functions in concentration- and generation-dependent manners, and especially maintenance costs increased. Consequently, multigenerational exposure to tetracycline induced changes in energy balance, resulting in the change of higher levels of biological responses. In contrast, D. magna acclimated to tetracycline exposure over multiple generations, as evidenced by the increased LC50 values. Transgenerational adaptation was related to the neonatal sensitivity and energy reserves of the organism. The results also emphasized the idea that the number of generation is an important factor for toxicity. The present study confirmed that toxic stress induces metabolic changes in an organism, thereby leading to increased energy consumption that results in adverse effects on reproduction.

The early protective effect of glutamine pretreatment and ischemia preconditioning in renal ischemia-reperfusion injury of rat

BACKGROUND

Heat shock proteins (HSP) play an important role in protecting cells against stress.

METHODS

Using a rat model, we tested the hypothesis that pretreatment with glutamine (Gln) and ischemia preconditioning (IPC) increase the expression of HSP resulting in attenuation of renal ischemia/reperfusion (I/R) injury. Sprague-Dawley rats were randomized into 4 groups [group I, Gln injection (+), IPC (+); group II, Gln injection (+), IPC (-); group III, saline injection (+), IPC (+); group IV, saline injection (+), IPC (-)]. Renal HSP70 expression was determined by Western blotting and kidney function was assessed by blood urea nitrogen and serum creatinine. Renal cross-sections were microscopically examined for tubular necrosis, exfoliation of tubular epithelial cells, cast formation, and monocyte infiltration.

RESULTS

Gln pretreatment increased intrarenal HSP expression (P = .031). In group I, tubulointerstitial abnormalities were clearly slighter compared with the other groups (P < .001).

CONCLUSION

Our experiments suggest that (1) a single dose of Gln could induce HSP expression and (2) IPC could relieve renal I/R injury. In addition, IPC combined with Gln pretreatment had a synergic protective effect against renal I/R injury.

Contrast-enhanced magnetic resonance angiography in the early period after kidney transplantation

Our objective was to evaluate the usefulness of three-dimensional (3-D) contrast-enhanced (CE) magnetic resonance angiography (MRA) to assess renal parenchyma, arterial inflow stenosis, and peritransplant fluid collections in the early period after kidney transplantation (KT). Between January 2010 and April 2011, we examined a consecutive series of 144 renal transplants using 3-D CE MRA at 14 days after KT. MRA showed parenchyma infarctions (n = 17, 11.8%), arterial inflow stenoses (n = 23, 16%), lymphoceles (n = 14, 9.7%), and hematomas (n = 6, 4.2%). The degree of renal transplant artery inflow stenosis was graded qualitatively based on diameter criterion; <50% = mild, 50% to 70% = moderate, and >70% = severe in 10 (6.9%), 5 (3.5%), and 8 (5.6%) subjects, respectively. The study recipients were divided into 3 groups according to the degree of renal artery inflow stenosis (group I: normal; group II: mild and moderate, <70%; group III: severe, >70%). Among group III patients who underwent digital subtraction angiography, 5 had percutaneous transluminal angioplasty or stenting performed after 1 month. Their mean resume creatinine levels at 1, 6, and 12 months after transplantation were not significantly different from those in the other groups (P = .391, .447, .110). The prevalence of graft loss (n = 2) was high in group III (P = .012), although the frequency of acute rejection episodes was not different among the groups (P = .890). The incidences of renal parenchyma infarction, peritransplant fluid collection and arterial inflow stenosis were unexpectedly high in the early period after KT. Thus, 3-D CE MRA provided a rapid global assessment of the renal parenchyma, transplant arterial system, and peritransplant fluid collection that can be helpful to detect or exclude many causes of renal transplant dysfunction.

Anterior Cervical Discectomy and Fusion Using a Double Cylindrical Cage versus an Anterior Cervical Plating System with Iliac Crest Autografts for the Treatment of Cervical Degenerative Disc Disease

Objective

Anterior cervical discectomy and fusion (ACDF) is often complicated by subsidence, pseudoarthrosis, kyphosis, and graft donor site morbidities. To decrease the occurrence of these complications, various types of cages have been developed. We designed this retrospective study to analyze and compare the efficacy and outcomes of ACDF using double cylindrical cages (DCC) (BK Medical, Seoul, Korea) versus an anterior cervical plating system with autogenous iliac crest grafts.

Methods

Forty-eight patients were treated with autograft and plating (plate group), and 48 with DCC group from October 2007 to October 2011. We analyzed construct length, cervical lordotic curvarture, the thickness of the prevertebral soft tissue, segmental instability, and clinical outcomes.

Results

There were no significant differences between the two groups with regard to the decrease in construct length or cervical lodortic curvature at the 3-, 6-, and 12-month follow-ups. The prevertebral soft tissue was thinner in the DCC group than the plate group immediately after surgery and at the 3-, 6-, and 12-month follow-ups. The difference in interspinous distance on flexion-extension was shorter in the plate group than the DCC group at the 3- and 6-month follow-ups. However, there was no significant difference in this distance between the two groups at the 12-month follow-up.

Conclusion

A double cylindrical cage is a good alternative for fusion in patients with cervical degenerative diseases; the surgical method is relatively simple, allows good synostosis, has less associated prevertebral soft tissue swelling, and complications associated with autografting can be avoided.