Outcome and risk prediction of early progression in patients with extranodal natural killer/T cell lymphoma from the CLCG study.

Recently, progression-free survival at 24 months (PFS24) was defined as clinically relevant for patients with extranodal NK/T cell lymphoma. Herein, the clinical data from two independent random cohorts (696 patients each in the primary and validation datasets) were used to develop and validate a risk index for PFS24 (PFS24-RI), and evaluate its ability to predict early progression. Patients achieving PFS24 had a 5-year overall survival (OS) of 95.8%, whereas OS was only 21.2% in those failing PFS24 (P<0.001). PFS24 was an important predictor of subsequent OS, independent of risk stratification. The proportion of patients achieving PFS24 and 5-year OS rates correlated linearly among risk-stratified groups. Based on multivariate analysis of the primary dataset, the PFS24-RI included five risk factors: stage II or III/IV, elevated lactate dehydrogenase, Eastern Cooperative Oncology Group score ≥2, primary tumor invasion, and extra-upper aerodigestive tract. PFS24-RI stratified the patients into low-risk (0), intermediate-risk (1-2), high-risk (≥3) groups with different prognoses. Harrell's C-index of PFS24-RI for PFS24 prediction was 0.667 in the validation dataset, indicating a good discriminative ability. PFS24-RI calibration indicated that the actual observed and predicted probability of failing PFS24 agreed well. PFS24-RI provided the probability of achieving PFS24 at an individual patient level.

Evidence of cure for extranodal nasal-type natural killer/T-cell lymphoma with current treatment: an analysis of the CLCG database.

Survival from extranodal nasal-type NK/T-cell lymphoma (ENKTCL) has substantially improved over the last decade. However, there is little consensus as to whether a population of patients with ENKTCL can be considered "cured" of the disease. We aimed to evaluate the statistical "cure" of ENKTCL in the modern treatment era. This retrospective multicentric study reviewed the clinical data of 1,955 patients with ENKTCL treated with non-anthracycline-based chemotherapy and/or radiotherapy in the China Lymphoma Collaborative Group multicenter database between 2008 and 2016. A non-mixture cure model with incorporation of background mortality was fitted to estimate cure fractions, median survival times and cure time points. The relative survival curves attained plateau for the entire cohort and most subsets, indicating that the notion of cure was robust. The overall cure fraction was 71.9%. The median survival was 1.1 years in uncured patients. The cure time was 4.5 years, indicating that beyond this time, mortality in ENKTCL patients was statistically equivalent to that in the general population. Cure probability was associated with B symptoms, stage, performance status, lactate dehydrogenase, primary tumor invasion, and primary upper aerodigestive tract site. Elderly patients (>60 years) had a similar cure fraction to that of younger patients. The 5-year overall survival rate correlated well with the cure fraction across risk-stratified groups. Thus, statistical cure is possible in ENKTCL patients receiving current treatment strategies. Overall probability of cure is favorable, though it is affected by the presence of risk factors. These findings have a high potential impact on clinical practice and patients' perspective.

Clinical characteristics, treatment, and survival of 30 patients with gastrointestinal natural killer/T-cell lymphoma.

BACKGROUND: The gastrointestinal (GI) tract is the second most frequent extranasal involvement site for ENKTL. This study aimed to explore the clinicopathological features, treatment models, survival outcomes, and prognosis of gastrointestinal ENKTL (GI-ENKTL). METHODS: The clinical data of GI-ENKTL patients were extracted from the China Lymphoma Collaborative Group (CLCG) database and were analyzed retrospectively. RESULTS: A total of 30 patients were enrolled, with a male/female ratio of 4:1 and a median age of 42 years. Twenty-nine patients received chemotherapy, of whom 15 patients received asparaginase-based (ASP-based) regimens. Moreover, seven received surgery and three received radiotherapy. The overall response an d complete remission rates were 50.0% and 30.0% for the whole cohort, 50.0% and 37.5% for patients treated with ASP-based regimens, and 50.0% and 25.0% for those treated with non-ASP-based regimens, respectively. The median follow-up was 12.9 months and the 1-year overall survival rate was 40.0% for the whole cohort. For those patients in an early stage, ASP-based regimens resulted in a superior 1-year progression-free survival rate compared to non-ASP-based regimens (100.0% vs. 36.0%, p = .07). However, ASP-based regimens did not improve survival in patients at an advanced stage. CONCLUSION: GI-ENKTL still has a poor prognosis, even in the era of modern asparaginase-based treatment strategies.

Characteristics and prognosis of distant metastasis after primary treatment for early-stage extranodal nasal-type natural killer/T-cell lymphoma from the China Lymphoma Collaborative Group database.

This study aimed to investigate the characteristics and prognosis of distant metastasis (DM) after primary treatment for early-stage extranodal nasal-type natural killer (NK)/T-cell lymphoma (ENKTCL). A total of 1619 patients from the China Lymphoma Collaborative Group database were retrospectively reviewed. The cumulative incidence of DM was assessed using Fine and Gray's competing risk analysis. The correlation between DM sites was evaluated using phi coefficients, while DM sites were classified using hierarchical clustering. Regression analysis was used to assess the linear correlation between DM-free survival (DMFS) and overall survival (OS). The 5-year cumulative DM rate was 26.2%, with the highest annual hazard rate being in the first year (14.9%). The most frequent DM sites were the skin and soft tissues (SSTs, 32.4%) and distant lymph nodes (LNs, 31.3%). DM sites were categorized into four subgroups of distinct prognosis - distant LN, SST, extracutaneous site, and lymphoma-associated hemophagocytic lymphohistiocytosis. SST or distant LN, solitary metastasis, and late-onset DM demonstrated a relatively favorable prognosis. Contemporary chemotherapy significantly decreased DM rates and improved DMFS. Decreased DM rates were further associated with increased OS probabilities. Our findings improve the understanding of the variable clinical behaviors of early-stage ENKTCL based on four distinct DM sites and thus provide guidance for future therapeutic decisions, metastatic surveillance, and translational trial design.

A comparative study of virus nucleic acid re-positive and non-re-positive patients infected with SARS-CoV-2 Delta variant strain in the Ningxia Hui Autonomous Region.

Objective: This study aimed to provide a basis for epidemic prevention and control measures as well as the management of re-positive personnel by analyzing and summarizing the characteristics of re-positive patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Delta variant infections discharged from a hospital in the Ningxia Hui Autonomous Region in 2021. Methods: This case-control study included a total of 45 patients with Delta variant infections diagnosed in the Fourth People's Hospital of the Ningxia Hui Autonomous Region between October 17 and November 28, 2021. Based on the nucleic acid test results post-discharge, the patients were dichotomized into re-positive and non-re-positive groups. Based on the time of the first re-positive test, the re-positive group was further divided into <7 and ≥7 days groups to compare their clinical characteristics and explore the possible influencing factors of this re-positivity. Results: Of the 45 total patients, 16 were re-positive (re-positivity rate: 35.6%), including four patients who were re-positive after 2 weeks (re-positivity rate: 8.8%). The median time of the first re-positive after discharge was 7 days (IQR: 14-3). The re-positive group was younger than the non-re-positive group (35 vs. 53, P < 0.05), had a higher proportion of patients who were not receiving antiviral therapy (56.2 vs. 17.2%, P < 0.05). The median CT value of nucleic acid in the re-positive group was considerably greater than that at admission (36.7 vs. 22.6 P < 0.05). The findings demonstrated that neutralizing antibody treatment significantly raised the average IgG antibody level in patients, particularly in those who had not received COVID-19 vaccine (P < 0.05). The median lowest nucleic acid CT value of the ≥7 days group during the re-positive period and the immunoglobulin G (IgG) antibody level at discharge were lower than those in the <7 days group (P < 0.05). When compared to the non-positive group, patients in the ≥7 days group had a higher median virus nucleic acid CT value (27.1 vs. 19.2, P < 0.05) and absolute number of lymphocytes at admission (1,360 vs. 952, P < 0.05), and a lower IgG antibody level at discharge (P < 0.05). Conclusions: In conclusion, this study found that: (1) The re-positivity rate of SARS-CoV-2 Delta variant infection in this group was 35.6%, while the re-positivity rate was the same as that of the original strain 2 weeks after discharge (8.0%). (2) Young people, patients who did not use antiviral therapy or had low IgG antibody levels at discharge were more likely to have re-positive. And the CT value of nucleic acid at the time of initial infection was higher in re-positive group. We speculated that the higher the CT value of nucleic acid at the time of initial infection, the longer the intermittent shedding time of the virus. (3) Re-positive patients were asymptomatic. The median CT value of nucleic acid was > 35 at the re-positive time, and the close contacts were not detected as positive. The overall transmission risk of re-positive patients is low.

Amplification of the Fluorescence Signal with Clustered Regularly Interspaced Short Palindromic Repeats-Cas12a Based on Au Nanoparticle-DNAzyme Probe and On-Site Detection of Pb2+ Via the Photonic Crystal Chip.

Although great headway has been made in DNAzyme-based detection of Pb2+, its adaptability, sensitivity, and accessibility in complex media still need to be improved. For this, we introduce new ways to surmount these hurdles. First, a spherical nucleic acid (SNA) fluorescence probe (Au nanoparticles-DNAzyme probe) is utilized to specifically identify Pb2+ and its suitability for precise detection of Pb2+ in complex samples due to its excellent nuclease resistance. Second, the sensitivity of Pb2+ detection is greatly enhanced via the use of a clustered regularly interspaced short palindromic repeats-Cas12a with target recognition accuracy to amplify the fluorescent signal upon the trans cleavage of the SNA (signal probe), and the limit of detection reaches as low as 86 fM. Third, we boost the fluorescence on photonic crystal chips with a bionic periodic arrangement by employing a straightforward detection device (smartphone and portable UV lamp) to achieve on-site detection of Pb2+ with the limit of detection as low as 24 pM. Based on the abovementioned efforts, the modified Pb2+ fluorescence sensor has the advantages of higher sensitivity, better specificity, accessibility, less sample consumption, and so forth. Moreover, it can be applied to accurately detect Pb2+ in complex biological or environmental samples, which is of great promise for widespread applications.

Autosomal dominant tubulointerstitial kidney disease with a novel heterozygous missense mutation in the uromodulin gene: A case report.

BACKGROUND: Autosomal dominant tubulointerstitial kidney disease (ADTKD) is a progressive chronic disease that is inherited in an autosomal dominant fashion. Symptoms include hyperuricemia, gout, interstitial nephritis, renal cysts, and progressive renal damage that can lead to end-stage renal disease. Mutations in the uromodulin gene (UMOD) characterize the ADTKD-UMOD clinical subtype of this disease. To date, > 100 UMOD mutations have been identified. Early diagnosis of ADTKD-UMOD is important to treat the disease, slow down disease progression, and facilitate the identification of potentially affected family members. CASE SUMMARY: We report a 40-year-old man harboring a novel heterozygous missense mutation in UMOD (c.554G>T; p. Arg185Leu). The patient had hyperuricemia, gout, and chronic kidney disease. The same mutation was detected in his daughter, aunt and cousin. CONCLUSION: A single nucleotide substitution in exon 3 of UMOD was responsible for the heterozygous missense mutation (c.554G>T, p.Arg185Leu).

New NF-κB Inhibitory Steroids from the Marine Sponge Dysidea avara Collected from the South China Sea.

Chemical investigation of the marine sponge Dysidea avara, collected from the South China Sea, yielded 13 steroids, including nine new (1-9) and four known (10-13) ones. The new structures were elucidated as (3S,14R)-3,14-dihydroxycholesta-5,8-dien-7-one (1), (22E,24R)-7α-ethoxy-5α,6α-epoxyergosta-8(14),22-dien-3ß-ol (2), 3ß-hydroxy-7α-ethoxy-5α,6α-epoxy-8(14)-cholestene (3), 3ß,5α-dihydroxy-6α-ethoxychofesta-7,9(11)-diene (4), 3ß,5α-dihydroxy-6ß-ethoxycholest-7-ene (5), (22E,24R)-24-ethoxy-3ß,5α-dihydroxy-6ß-ethoxyergosta-7,22-diene (6), (22E)-3ß,5α-dihydroxy-6ß-ethoxycholesta-7,22-diene (7), 24-ethoxy-3ß,5α-dihydroxy-6ß-ethoxycholest-7-ene (8 and 9), by extensive spectroscopic analyses, such as HR-ESI-MS, 1D and 2D NMR data. The absolute configuration of 1 was assigned by comparison the experimental ECD spectra with the calculated ones. Among the 13 metabolites, compounds 1, 4, 11, 12, and 13 showed NF-κB inhibitory activities in human HER-293 cells with IC50 values of 6.4, 18.7, 8.1, 9.6, and 7.5 µM, respectively. Preliminary structure-activity relationship analysis unveiled that the conjugated ketones or unsaturated double bonds might be the functional groups for the five active steroids.

Mutagenicity evaluation to UV filters of benzophenone-6, benzophenone-8, and 4-methylbenzylidene camphor by Ames test.

Benzophenone (BPs) and 4-Methylbenzylidene Camphor are used as ultraviolet (UV) filters to protect the skin and hair in personal care products. The discharging of the three chemicals may endanger the receiving water ecosystem. In the present study, the mutagenicity of BP-6, BP-8, and 4-Methylbenzylidene Camphor was tested using the Salmonella typhimurium reverse mutation test (Ames test) in the system with and without rat liver microsomal preparations (S9). Four S.typhimurium strains, TA97, TA98, TA100, and TA102 were employed in the Ames tests. The mutagenicity was detected from all three chemicals. The addition of S9 increased the mutation ratios of three chemicals to four strains, except BP-6 to TA100 strain and 4-MBC to TA97 and TA98 strain. In the mixed experiment, all positive effects were detected in the absence of S9. However, the results all became negative in the presence of S9. For the mixture of BP-6 and 4-MBC, positive results were detected on four tester strains except for the TA100 strain. For the mixture of BP-6, BP-8, and 4-MBC, positive results were detected on four strains. The mixture test results showed antagonism in mutagenicity for the mixture of BP-6 and 4-MBC to TA98 and TA100 strains and the mixture of BP-6, BP-8, and 4-MBC to TA100 and TA102 strains.

Abdominal hemorrhage after peritoneal dialysis catheter insertion: A rare cause of luteal rupture: A case report.

BACKGROUND: Abdominal hemorrhage is a complication of peritoneal dialysis catheter (PDC) insertion that cannot be neglected, and its causes are mainly related to surgical injury. This article reports a case of massive abdominal hemorrhage that was caused by a rare rupture of corpus luteum shortly after PDC during the initiation of peritoneal dialysis (PD) insertion. CASE SUMMARY: A 37-year-old woman was surgically placed a Tenckhoff catheter because of end-stage renal disease. On the third postoperative day, the color of the abdominal drainage fluid was pink, and deepened gradually. It turned pale after initiating conservative treatment. On the tenth postoperative day, the color of the abdominal drainage fluid suddenly turned dark red, and the color progressively deepened. The patient's hemoglobin dropped from 88 g/L to 57 g/L. Abdominal computed tomography (CT) indicated abdominal effusion and a high-density shadow in the abdominal cavity. The surgeon performed a laparotomy and found that the corpus luteum had ruptured on the right side and a left ovarian blood body had formed. The gynecologist repaired the ovary and performed a bilateral oophoroplasty. After the operation, the patient stopped bleeding and hemodialysis was temporarily stopped. PD was resumed after half a month. The patient's condition improved, and she was discharged 14 d after the laparotomy. CONCLUSION: If abdominal hemorrhage occurs in women of childbearing age after PDC insertion, luteal rupture should be considered as the cause.

Detection of Amyloid ß Oligomers by a Fluorescence Ratio Strategy Based on Optically Trapped Highly Doped Upconversion Nanoparticles-SiO2@Metal-Organic Framework Microspheres.

Alzheimer's disease (AD), known as a progressive neurodegenerative disorder, has had a terrible impact on the health of aged people. Due to its severity, early diagnosis of AD is significant to retard the progress and provide timely treatment. Here, we report a fluorescence ratio detection of AD biomarker amyloid ß oligomers (AßOs) by combining highly doped upconversion nanoparticles-SiO2@metal-organic framework/black hole quencher (H-USM/BHQ-1) microspheres with optical tweezer (OT) microscopic imaging. Optical trapping a single microsphere not only avoids the interference of fluid viscosity but also provides a high power density laser source to efficiently stimulate upconversion luminescence (UCL) of highly doped upconversion nanoparticles (H-UCNPs). Under this condition, H-UCNPs show stronger UCL and greater power-dependent properties compared to low-doped ones. Moreover, the closely packed quenching molecules BHQ-1 on a metal-organic framework (ZIF-8) exhibit excellent quenching efficiency for upconversion 525 and 540 nm emission. Also, the luminescent resonance energy transfer efficiency reaches 89.58%. When different concentrations of AßOs are present, the UCL540 recovers due to the decomposition of ZIF-8 and the release of BHQ-1. Using 540 and 654 nm emission ratio of highly doped UCNPs as reporters, the limit of detection reaches 28.4 pM for the quantitative determination of AßOs. Besides, this strategy is able to selectively quantify the AßO concentration. Therefore, we demonstrated the combination of optical trapping and highly doped UCNPs which is applied for the detection of AßOs with high sensitivity and specificity.

Progression-free survival at 24 months and subsequent survival of patients with extranodal NK/T-cell lymphoma: a China Lymphoma Collaborative Group (CLCG) study.

Limited evidence supports the use of early endpoints to evaluate the success of initial treatment of extranodal NK/T-cell lymphoma (ENKTCL) in the modern era. We aim to analyze progression-free survival at 24 months (PFS24) and subsequent overall survival (OS) in a large-scale multicenter cohort of patients. 1790 patients were included from the China Lymphoma Collaborative Group (CLCG) database. Subsequent OS was defined from the time of PFS24 or progression within 24 months to death. OS was compared with age- and sex-matched general Chinese population using expected survival and standardized mortality ratio (SMR). Patients who did not achieve PFS24 had a median OS of 5.3 months after progression, with 5-year OS rate of 19.2% and the SMR of 71.4 (95% CI, 62.9-81.1). In contrast, 74% patients achieved PFS24, and the SMR after achieving PFS24 was 1.77 (95% CI, 1.34-2.34). The observed OS rate after PFS24 versus expected OS rate at 5 years was 92.2% versus 94.3%. Similarly, superior outcomes following PFS24 were observed in early-stage patients (5-year OS rate, 92.9%). Patients achieving PFS24 had excellent outcome, whereas patients exhibiting earlier progression had a poor survival. These marked differences suggest that PFS24 may be used for study design and risk stratification in ENKTCL.

Validation of nomogram-revised risk index and comparison with other models for extranodal nasal-type NK/T-cell lymphoma in the modern chemotherapy era: indication for prognostication and clinical decision-making.

Derived from our original nomogram study by using the risk variables from multivariable analyses in the derivation cohort of 1383 patients with extranodal NK/T-cell lymphoma, nasal-type (ENKTCL) who were mostly treated with anthracycline-based chemotherapy, we propose an easily used nomogram-revised risk index (NRI), validated it and compared with Ann Arbor staging, the International Prognostic Index (IPI), Korean Prognostic Index (KPI), and prognostic index of natural killer lymphoma (PINK) for overall survival (OS) prediction by examining calibration, discrimination, and decision curve analysis in a validation cohort of 1582 patients primarily treated with non-anthracycline-based chemotherapy. The calibration of the NRI showed satisfactory for predicting 3- and 5-year OS in the validation cohort. The Harrell's C-index and integrated Brier score (IBS) of the NRI for OS prediction demonstrated a better performance than that of the Ann Arbor staging system, IPI, KPI, and PINK. Decision curve analysis of the NRI also showed a superior outcome. The NRI is a promising tool for stratifying patients with ENKTCL into risk groups for designing clinical trials and for selecting appropriate individualized treatment.

Toxicity Changes of Heavily Polluted River Sediments on Daphnia magna Before and After Dredging.

Most of the pollutants discharged into the water will deposit at the bottom of the river and may cause biological toxicity. Daphnia magna-elutriate toxicity bioassay was usually applied to evaluate sediment toxicity. However, the loss of hydrophobic pollutants during the elutriating will lead to the underestimation of sediment toxicity. The purpose of this study is to apply the optimized immobilized sediments to D. magna test, so it can be directly exposed to the sediments and get accurate sediment toxicity results. The optimized immobilized sediment was prepared by mixing 1 g sediment with 7.5 mL 3% (w/v) alginate and hardened in a 4% (w/v) CaCl2 solution. Based on D. magna acute toxicity test, the median lethal concentration values (LC50) of the spiked Cu and diuron measured by using immobilized sediment were both lower than that of using the elutriate, in which the difference of Cu-LC50 reached a significant level. The toxicity changes of sediment in the polluted rivers before and after dredging were then be evaluated by using the immobilized sediment. The toxicity of the sediments at four sites decreased from acute-toxic (pro-dredging) to slight-acute-toxic and nontoxic (post-dredging).

First-line non-anthracycline-based chemotherapy for extranodal nasal-type NK/T-cell lymphoma: a retrospective analysis from the CLCG.

The present study investigated the survival benefit of non-anthracycline (ANT)-based vs ANT-based regimens in a large-scale, real-world cohort of patients with extranodal natural killer (NK)/T-cell lymphoma, nasal type (ENKTCL). Within the China Lymphoma Collaborative Group (CLCG) database (2000-2015), we identified 2560 newly diagnosed patients who received chemotherapy with or without radiotherapy. Propensity score matching (PSM) and multivariable analyses were used to compare overall survival (OS) and progression-free survival (PFS) between the 2 chemotherapy regimens. We explored the survival benefit of non-ANT-based regimens in patients with different treatments in early-stage disease and in risk-stratified subgroups. Non-ANT-based regimens significantly improved survivals compared with ANT-based regimens. The 5-year OS and PFS were 68.9% and 59.5% for non-ANT-based regimens compared with 57.5% and 44.5% for ANT-based regimens in the entire cohort. The clinical advantage of non-ANT-based regimens was substantial across the subgroups examined, regardless of stage and risk-stratified subgroup, and remained significant in early-stage patients who received radiotherapy. The survival benefits of non-ANT-based regimens were consistent after adjustment using multivariable and PSM analyses. These findings provide additional evidence supporting non-ANT-based regimens as a first-line treatment of patients with ENKTCL.

Risk-based, response-adapted therapy for early-stage extranodal nasal-type NK/T-cell lymphoma in the modern chemotherapy era: A China Lymphoma Collaborative Group study.

We aimed to determine the survival benefits of chemotherapy (CT) added to radiotherapy (RT) in different risk groups of patients with early-stage extranodal nasal-type NK/T-cell lymphoma (ENKTCL), and to investigate the risk of postponing RT based on induction CT responses. A total of 1360 patients who received RT with or without new-regimen CT from 20 institutions were retrospectively reviewed. The patients had received RT alone, RT followed by CT (RT + CT), or CT followed by RT (CT + RT). The patients were stratified into different risk groups using the nomogram-revised risk index (NRI). A comparative study was performed using propensity score-matched (PSM) analysis. Adding new-regimen CT to RT (vs RT alone) significantly improved overall survival (OS, 73.2% vs 60.9%, P < .001) and progression-free survival (PFS, 63.5% vs 54.2%, P < .001) for intermediate-risk/high-risk patients, but not for low-risk patients. For intermediate-risk/high-risk patients, RT + CT and CT + RT resulted in non-significantly different OS (77.7% vs 72.4%; P = .290) and PFS (67.1% vs 63.1%; P = .592). For patients with complete response (CR) after induction CT, initiation of RT within or beyond three cycles of CT resulted in similar OS (78.2% vs 81.7%, P = .915) and PFS (68.2% vs 69.9%, P = .519). For patients without CR, early RT resulted in better PFS (63.4% vs 47.6%, P = .019) than late RT. Risk-based, response-adapted therapy involving early RT combined with CT is a viable, effective strategy for intermediate-risk/high-risk early-stage patients with ENKTCL in the modern treatment era.

Assessment of Biological Toxicity and Ecological Safety for Urban Black-Odor River Remediation.

The judgment and assessment of remediation effect on urban black-odor river still depend on the physical-chemical parameters and lack in ecological safety effects. A set of combined biological toxicity tests were applied to evaluate the ecological effects of one urban black-odor river before and after the remediation. The special growth rate of Chlorella vulgaris and mortality rate of Daphnia magna were used to assess acute toxicity. The Salmonella Typhimurium/Reverse Mutation Assay was applied to test the mutagenicity. The tests by C. vulgaris growth showed that there was no inhibition before and after remediation by overlying water, in contrast promoted the growth of C. vulgaris. The tests by D. magna showed slight toxicity on site 3# before remediation and nontoxic after remediation. The mutagenicity of organic extracts from overlying water at all sampling sites were positive before remediation, but were eliminated after remediation except from 3 of 4 sites on TA98 strain. The addition of the liver microsomal S9 induced the positive mutagenicity on site 4# compared to S9 absence. The results clarified the applicable and the importance of the biological toxicity tests on assessing the remediation effect and potential ecological risk of urban black-odor river.

Development and application of a novel whole sediment toxicity test using immobilized sediment and Chlorella vulgaris.

The sediments of water bodies are not only pollutants sink but also sources of pollution. The assessment for the whole-sediment toxicity is still challenging research. Although the application of immobilized algal bead could overcome the practical difficulties in sediment toxicity assay, the weak growth and reduced sensitivity of algae inside the bead restricted its application. In this study, a sediment toxicity test was developed using immobilized sediment and Chlorella vulgaris. The immobilized sediment was prepared by mixing 2 g freeze-dried sediment and 15-mL 3% (w/v) alginate and hardened in a 4% (w/v) CaCl2 solution. Based on a C. vulgaris growth inhibition test and using the immobilized sediment, the median effective concentration value (EC50) of the spiked Cu and diuron was 506.23 and 2.37 mg/kg respectively, lower than that of using immobilized algae (719.62 and 3.12 mg/kg respectively). The Cu and diuron concentrations in the corresponding overlying water from the spiked immobilized and free sediment showed that sediment pollutants' diffusion capacity was not decreased after immobilization. By using the immobilized sediment in algae toxicity bioassay, the changes in the sediment toxicity of a polluted river before and after dredging was evaluated. The C. vulgaris growth inhibition in sediment A decreased from 81.94% to 8.43%; sediment B remained unchanged; sediment C stimulated the growth of C. vulgaris before dredging (-15.56%), but inhibited the algae growth after dredging (26.88%), and sediment D decreased growth inhibition from 32.66% to -12.60%.