Application of biochar and compost improved soil properties and enhanced plant growth in a Pb-Zn mine tailings soil.

This study evaluated the effect of biochar and compost on physiochemical properties, heavy metal content, microbial biomass, enzyme activities, and plant growth in Pb-Zn mine tailings. In this study, a pot experiment was conducted to evaluate the effects of biochar, compost, and their combination on the availability of heavy metals, physicochemical features, and enzyme activities in mining soil. Compared to separate addition, the combined application of biochar and compost was more effective to improve soil pH, soil organic carbon (SOC), total nitrogen (TN), available phosphorus (AP), and potassium (AK). All amendments significantly decreased CaCl2-extractable Pb, Zn, Cu, and Cd. Soil enzyme activities were activated by biochar and compost. Meanwhile, the addition of biochar and compost decreased heavy metal content in plant tissues and increased plant biomass. Pearson's correlation analysis showed that plant biomass was positively correlated with nutrient levels, microbial biomass, and enzyme activities, whereas it was negatively correlated with CaCl2-extractable heavy metals. These results enhance our understanding of the ecological functions of biochar and compost on the restoration of mining soil and reveal the potential benefit of organic amendments on the improvement of mining soil quality.

A practical method for identifying key factors in the distribution and formation of heavy metal pollution at a smelting site.

Smelting activities are the main pathway for the anthropogenic release of heavy metals (HMs) into the soil-groundwater environment. It is vital to identify the factors affecting HMs pollution to better prevent and manage soil pollution. The present study conducted a comprehensive investigation of HMs in soil from a large abandoned Zn smelting site. An integrated approach was proposed to classify and quantify the factors affecting HMs pollution in the site. Besides, the quantitative relationship between hydrogeological characteristics, pollution transmission pathways, smelting activities and HMs pollution was established. Results showed that the soils were highly contaminated by HMs with a pollution index trend of As > Zn > Cd > Pb > Hg. In identifying the pollution hotspots, we conclude that the pollution hotspots of Pb, As, Cd, and Hg present a concentrated distribution pattern. Geo-detector method results showed that the dominant driving factors for HMs distribution and accumulation were the potential pollution source and soil permeability. Additionally, the main drivers are variable for different HMs, and the interaction among factors also enhanced soil HMs contamination. Our analysis illustrates how the confounding influences from complex environmental factors can be distilled to identify key factors in pollution formation to guide future remediation strategies.

Spatial distribution of toxic metal(loid)s at an abandoned zinc smelting site, Southern China.

Toxic metal(loid) (TM) soil pollution at large-scale non-ferrous metal smelting contaminated sites is of great concern in China, but there are no detailed reports relating to them. A comprehensive study was conducted to determine contamination characteristics and horizontal and vertical spatial distribution patterns of soils at an abandoned zinc smelting site in Southern China. The spatial distribution of TMs revealed that soil environmental quality was seriously threatened, with Cd, Zn, As, Pb and Hg being the main contaminants present. The distribution of all TMs showed strong spatial heterogeneity and were expressed as a "patchy aggregation" pattern due to strong anthropogenic and production activities. Vertical migration of TMs indicated that the pollutants were mainly concentrated in the fill layers. Different contaminants had various migration depths, with migration occurring as: Cd > Hg > As > Zn > Pb> Cu> Mn> Sb. Analysis of their spatial variability showed that As, Pb, Cd and Hg had strong regional spatial variability. This research provides a new approach to comprehensively analyze TM pollution characteristics of non-ferrous smelting sites. It provides valuable information for guiding post-remediation strategies at abandoned non-ferrous metal smelting sites.

Screening and identification of salivary biomarkers for assessing the effects of exogenous testosterone administration on HPG and HPA axes and ECS.

The contents of steroids and endocannabinoids along with the ratios between them would be candidate biomarkers for sensitively and comprehensively assessing the role of testosterone in regulating the activities of the hypothalamus-pituitary-gonadal (HPG) axis, the hypothalamus-pituitaryadrenal (HPA) axis and endogenous cannabinoid system (ECS). However, previous studies mostly used the contents rather than the ratios as biomarkers. This study aimed to systematically screen and identify sensitive biomarkers from 21 candidates including both the contents of nine steroids and one endocannabinoid and their ratios in saliva. Three screening criteria were whether there were intergroup differences, time-dependent changes and considerable relative stability during a 4-h period after exogenous testosterone administration. This study used LC-APCI+-MS/MS to determine the salivary levels of the candidate biomarkers on 62 male healthy undergraduates who were divided into testosterone administration and placebo control groups. The results revealed that salivary testosterone, androstenedione, DHEA and the ratios of testosterone to estradiol and AEA, and of cortisol to testosterone and DHEA were sensitive biomarkers for assessing the effects of testosterone administration on the three neuroendocrine systems because they all showed significant intergroup differences and time-dependent changes and good relative stability. Salivary cortisol, cortisone and the ratios of testosterone to androstenedione and DHEA and of androstenedione to estrone, and of cortisol to cortisone, androstenedione and AEA might be suitable biomarkers because they met only two of the three criteria, but needed to be validated in the future. The rest biomarkers were unsuitable because they mostly showed no significant intergroup differences, blunt time-dependent changes and poor relative stability.

Homoharringtonine and SAHA synergistically enhance apoptosis in human acute myeloid leukemia cells through upregulation of TRAIL and death receptors.

Single­agent histone deacetylase (HDAC) inhibitors have exhibited marked antileukemic activity in preclinical and clinical studies and have undergone trials in combination with standard chemotherapeutics. However, the mechanisms of action of combination therapies are not completely understood. In the present study, a novel strategy for treatment of acute myeloid leukemia (AML) was identified, in which the chemotherapeutic agent, homoharringtonine (HHT), was combined with suberoylanilide hydroxamic acid (SAHA), a pan­HDAC inhibitor. A synergistic effect was observed when HHT was added to SAHA to induce apoptosis in Kasumi­1 and THP­1 leukemia cells. This combination was found to significantly enhance the activation of caspase­8 and ­9 compared with treatment with each drug separately. Notably, while SAHA induced upregulation of death receptor 4 (DR4) and DR5, HHT upregulated tumor necrosis factor­related apoptosis-inducing ligand (TRAIL) expression in a dose­dependent manner. In addition, the synergistic effect between HHT and SAHA was blocked partially using a specific anti­TRAIL antibody. The combination therapy was also found to significantly inhibit the growth of leukemia xenografts in vivo with enhanced apoptosis. These results indicate that, by regulating the induction of TRAIL and activation of the TRAIL apoptotic pathway, it is possible to administer HHT at low concentrations in combination with SAHA as an effective therapeutic approach for the treatment of AML.

[Characteristics and outcome of chromosomal abnormalities in Ph negative cells of chronic myelogenous leukemia patients treated with tyrosine kinase inhibitors].

OBJECTIVE: To investigate cytogenetic features and outcome of chromosomal abnormalities in Philadelphia negative cells (Ph(-)CAs) of chronic myelogenous leukemia (CML) patients treated with tyrosine kinase inhibitors. METHODS: Clinical and laboratory data of 15 CML patients in which Ph(-)CAs occurred after tyrosine kinase inhibitors therapy were collected and analyzed. RESULTS: Of 15 cases with Ph(-)CAs, 12 patients were treated with imatinib, 2 were treated with dasatinib and 1 was treated with bosutinib. + 8 was the most common abnormality in Ph(-)CAs, which accounted for 46.7% of all. Ph(-)CAs usually occurred when Ph(+)cells decreased or disappeared due to tyrosine kinase inhibitors therapy. The average time for the appearance of Ph(-)CAs was 11.1 months (1-28 months). In 7 patients, the Ph(-)CAs have disappeared in 10.9 months (3-24 months). In such patients, no myelodysplastic syndrome or acute leukemia was observed. One patient has progressed to acute monocytic leukemia with Ph(+)cells. All remaining patients have achieved bone morrow remission, among which 11 patients achieved complete cytogenic response and 4 patients even achieved complete molecular response. CONCLUSION: The majority of Ph(-)CAs developed in CML patients are transient in nature. They may develop following imatinib, dasatinib or bosutinib therapy but do not interfere with the therapeutic effects of tyrosine kinase inhibitors.

Heat shock protein 90 inhibition results in altered downstream signaling of mutant KIT and exerts synergistic effects on Kasumi-1 cells when combining with histone deacetylase inhibitor.

KIT mutations may be associated with a poor prognosis in t(8;21) AML. Heat shock protein 90 (Hsp90) is a molecular chaperone frequently used by cancer cells to stabilize mutant oncoproteins. Inhibition of Hsp90 by 17-allylamino-17-demethoxygeldanamycin (17-AAG) disrupted downstream signaling pathways of mutant KIT in Kasumi-1 cells. AML1-ETO fusion gene and mutated KIT act as "two-hit" factors in Kasumi-1 cells. Histone deacetylation (HDAC) inhibitors sodium phenylbutyrate (PB) and valproic acid (VPA) block AML1-ETO. Co-treatment with 17-AAG and PB or 17-AAG and VPA resulted in a synergistic effect in Kasumi-1 cells. Our results confirmed that Hsp90 and mutated KIT were valid molecular targets in the therapy of AML.

[Cytogenetic analysis of 154 case of acute myeloid leukemia with t(8;21)].

OBJECTIVE: To investigate the cytogenetic features of acute myeloid leukemia (AML) with t(8;21). METHODS: The clinical characteristics of 154 cases of acute myeloid leukemia with t(8;21) in our hospital were analyzed retrospectively. According to the chromosome karyotype, all cases were divided into three groups: the group without additional chromosome abnormality, the group with single sex chromosome loss and the group with additional chromosome abnormalities other than sex chromosome loss. RESULT: In this study, according to FAB classification, there were 127 cases of M2 (82.5%), 15 of M5 (9.7%), 6 of M4 (3.9%), 4 of M1(2.6%) and 2 of M0(1.3%). Cytogenetically, 85 (55.2%) AML patients with t(8;21) had additional chromosome abnormalities. The most common abnormalities were sex chromosome loss, of which -Y was detected in 44.1% of the male karyotype and X in 27.9%. Beside that, there were 9 cases of 9q- (5.8%), 5 of +8(3.3%),3 of +4(2.0%) and 17 of other chromosome anomalies (11.4%). In the group of t(8;21) with additional chromosome abnormalities, 11 cases (35.5%) were non-M2 AML, higher than that in single t(8;21) group (17.4%)(P<0.05); however, there was no significant difference between the group of single t(8;21) and the group of t(8;21) with single sex chromosome loss(P>0.05). CONCLUSION: t(8;21) translocation is usually accompanied by additional chromosome abnormalities, particularly in M2; while t(8;21) with additional chromosome abnormalities other than sex chromosome loss is more frequently observed in non-M2 AML.

CD19-positive acute myeloblastic leukemia with trisomy 21 as a sole acquired karyotypic abnormality.

We report that a 63-year-old Chinese female had acute myeloblastic leukemia (AML) in which trisomy 21 (+21) was found as the sole acquired karyotypic abnormality. The blasts were positive for myeloperoxidase, and the immunophenotype was positive for cluster of differentiation 19 (CD19), CD33, CD34, and human leukocyte antigens (HLA)-DR. The chromosomal analysis of bone marrow showed 47,XX,+21[2]/46,XX[18]. Fluorescent in situ hybridization (FISH) showed that three copies of AML1 were situated in separate chromosomes, and that t(8;21) was negative. The patient did not have any features of Down syndrome. A diagnosis of CD19-positive AML-M5 was established with trisomy 21 as a sole acquired karyotypic abnormality. The patient did not respond well to chemotherapy and died three months after the diagnosis. This is the first reported case of CD19-positive AML with trisomy 21 as the sole cytogenetic abnormality. The possible prognostic significance of the finding in AML with +21 as the sole acquired karyotypic abnormality was discussed.