Mutant U2AF1-Induced Mis-Splicing of mRNA Translation Genes Confers Resistance to Chemotherapy in Acute Myeloid Leukemia

Patients with primary refractory acute myeloid leukemia (AML) have a dismal long-term prognosis. Elucidating the resistance mechanisms to induction chemotherapy could help identify strategies to improve AML patient outcomes. Herein, we retrospectively analyzed the multiomics data of more than 1,500 AML cases and found that patients with spliceosome mutations had a higher risk of developing refractory disease. RNA splicing analysis revealed that the mis-spliced genes in refractory patients converged on translation-associated pathways, promoted mainly by U2AF1 mutations. Integrative analyses of binding and splicing in AML cell lines substantiated that the splicing perturbations of mRNA translation genes originated from both the loss and gain of mutant U2AF1 binding. In particular, the U2AF1S34F and U2AF1Q157R mutants orchestrated the inclusion of exon 11 (encoding a premature termination codon) in the eukaryotic translation initiation factor 4A2 (EIF4A2). This aberrant inclusion led to reduced eIF4A2 protein expression via nonsense-mediated mRNA decay. Consequently, U2AF1 mutations caused a net decrease in global mRNA translation that induced the integrated stress response (ISR) in AML cells, which was confirmed by single-cell RNA sequencing. The induction of ISR enhanced the ability of AML cells to respond and adapt to stress, contributing to chemoresistance. A pharmacologic inhibitor of ISR, ISRIB, sensitized U2AF1 mutant cells to chemotherapy. These findings highlight a resistance mechanism by which U2AF1 mutations drive chemoresistance and provide a therapeutic approach for AML through targeting the ISR pathway.

SIGNIFICANCE

U2AF1 mutations induce the integrated stress response by disrupting splicing of mRNA translation genes that improves AML cell fitness to enable resistance to chemotherapy, which can be targeted to improve AML treatment.

Pan-caner analysis identifies PSMA7 as a targets for amplification at 20q13.33 in tumorigenesis

The chromosome 20 long arm (20q) is one of the genomic hotspots where copy number alterations frequently occur in multiple types of tumors. However, it remains elusive which genes are implicated in 20q-related tumorigenesis. Here, by querying TCGA and GEO databases, we observed frequent copy number amplification at 20q and the chromosome subband 20q13.33 was amplificated in multiple cancers. Among those genes at 20q13.33, PSMA7 was found with the strongest correlation with cancers. Further analysis revealed that PSMA7 amplification was the most frequent genetic alteration event conferring adverse prognosis in various cancers. Consistent with the strong positive correlation between PSMA7 amplification and gene expression, elevated PSMA7 expression was observed in 20 of 33 types of cancers with a close link to adverse outcomes in certain tumors. In addition, PSMA7 was essential for the growth of almost 1095 cancer lines. Mechanistically, aberrant PSMA7 most probably influenced the proteasome and protease-related pathways to promote tumorigenesis and might be antagonized by several compounds, e.g., Docetaxel in relevant cancers. The current in-depth pan-cancer analysis refines our understanding of the crucial oncogenic role of copy number amplifications at PSMA7 loci at the novel chromosome amplicon 20q13.33 across different tumors.

Occurrence of chromosomal abnormalities in Philadelphia chromosome-negative metaphases in patients with chronic-phase chronic myeloid leukemia undergoing TKI treatments

Forty-three chromosomal abnormalities in Philadelphia-negative metaphases (Ph-CAs) appeared in 35 of 432 patients in chronic phase chronic myeloid leukemia (CP-CML) undergoing tyrosine kinase inhibitor (TKI) treatments. These CAs were mostly common in trisomy-8 (16 cases), trisomy-Y (five cases), and monosomy-7 (five cases). Furthermore, Ph- CAs were significantly associated with higher platelet count (494 × 10⁹/L vs. 326 × 10⁹/L, p = .006), and higher incidence of true clonal evolution in Ph-positive metaphase (22.9% vs. 9.1%, p = .017). Additionally, patients with Ph- CAs had worse rates of complete cytogenetic remission (76% vs. 86%, p = .0091), major molecular remission (55% vs. 76%, p = .001), progression-free survival (47% vs. 86%, p < .001), but a similar overall survival rates compared to those in patients without Ph- CAs. In conclusion, Ph- CAs may predict worse response to TKI therapies and survival in patients with CP-CML, thus requiring close cytogenetic monitoring.

Application of High-Throughput Sequencing in the Diagnosis of Inherited Thrombocytopenia

Inherited thrombocytopenia is a group of hereditary diseases with a reduction in platelet count as the main clinical manifestation. Clinically, there is an urgent need for a convenient and rapid diagnosis method. We introduced a high-throughput, next-generation sequencing (NGS) platform into the routine diagnosis of patients with unexplained thrombocytopenia and analyzed the gene sequencing results to evaluate the value of NGS technology in the screening and diagnosis of inherited thrombocytopenia. From a cohort of 112 patients with thrombocytopenia, we screened 43 patients with hereditary features. For the blood samples of these 43 patients, a gene sequencing platform for hemorrhagic and thrombotic diseases comprising 89 genes was used to perform gene detection using NGS technology. When we combined the screening results with clinical features and other findings, 15 (34.9%) of 43patients were diagnosed with inherited thrombocytopenia. In addition, 19 pathogenic variants, including 8 previously unreported variants, were identified in these patients. Through the use of this detection platform, we expect to establish a more effective diagnostic approach to such disorders.

Societal implications of medical insurance coverage for imatinib as first-line treatment of chronic myeloid leukemia in China: a cost-effectiveness analysis

OBJECTIVES

Imatinib (Glivec) and nilotinib (Tasigna) have been covered by critical disease insurance in Jiangsu province of China since 2013, which changed local treatment patterns and outcomes of patients with chronic myeloid leukemia (CML). This study evaluated the long-term cost-effectiveness of insurance coverage with imatinib as the first-line treatment for patients with CML in China from a societal perspective.

METHODS

A decision-analytic model based on previously published and real-world evidence was applied to simulate and evaluate the lifetime clinical and economic outcomes associated with CML treatments before and after imatinib was covered by medical insurance. Incremental cost-effectiveness ratio (ICER) was calculated with both costs and quality-adjusted life years (QALYs) discounted at 3% annually. Different assumptions of treatment benefits and costs were taken to address uncertainties and were tested with sensitivity analyses.

RESULTS

In base case analysis, both cost and effectiveness of CML treatments increased after imatinib was covered by the medical insurance; on average, the incremental QALY and cost were 5.5 and ¥277,030 per patient in lifetime, respectively. The ICER of insurance coverage with imatinib was ¥50,641, which is less than the GDP per capita of China. Monte Carlo simulation resulted in the estimate of 100% probability that the insurance coverage of imatinib is cost-effective. Total cost was substantially saved at 5 years after patients initiated imatinib treatment with insurance coverage compared to no insurance coverage, the saved cost at 5 years was ¥99,565, which included the cost savings from both direct (e.g. cost of bone marrow or stem cell transplant) and indirect costs (e.g. productivity loss of patients and care-givers).

CONCLUSIONS

The insurance coverage of imatinib is very cost-effective in China, according to the local cost and clinical data in Jiangsu province. More importantly, the insurance coverage of imatinib and nilotinib have changed the treatment patterns of CML patients, thus dramatically increasing life expectancy and quality-of-life (QoL) saving on productivity losses for both CML patients and their caregivers.

The impact of medical insurance coverage and molecular monitoring frequency on outcomes in chronic myeloid leukemia: real-world evidence in China

OBJECTIVES

Imatinib (Glivec) has been covered by critical disease insurance for treatment of chronic myeloid leukemia (CML) in Jiangsu province of China since 2013. Further, free molecular monitoring has been provided to patients at top clinical centers as part of a pilot study that has changed the local treatment pattern and outcomes of patients with CML. This study evaluates the impact of medical insurance coverage and the molecular monitoring frequency on outcomes of patients with CML treated at a central hospital in Jiangsu, China, according to patient-level data.

METHODS

The study investigated 335 CML patients receiving medical treatment in a central hospital between January 1, 2011 and December 31, 2014. Demographic and clinical characteristics were extracted from the patients' clinical records. Univariate and multivariate analyses using the logistic regression model were performed to identify the differences in outcomes of major molecular response (MMR) or complete cytogenetic response (CCyR) between patients who were insured vs uninsured, or between patients with frequency of PCR monitoring ≤2 times vs ≥3 times per year.

RESULTS

Both the achievement of MMR (BCR-ABL^IS ≤0.1%) (50.4% vs 37.5%) and CCyR (80.7% vs 62.8%) at 12 months have shown significant differences that favored patients with insurance coverage of imatinib, while there was no significant difference in the outcome of BCR-ABL^IS ≤1% between insured and non-insured groups (56.0% vs 51.3%) at 6 months. The long-term results at 24 months demonstrated that there was a statistically significant difference in MMR rates between the group with 3 or more PCR monitoring tests per year and the group of patients with 2 or less PCR tests per year (76.9% vs 52.2%).

CONCLUSIONS

The study findings suggest that CML patients benefit from insurance coverage of imatinib and higher frequency (≥3) of regularly scheduled molecular monitoring PCR in China.

Multiple MYO18A-PDGFRB fusion transcripts in a myeloproliferative neoplasm patient with t(5;17)(q32;q11)

BACKGROUND

Myeloproliferative neoplasms (MPNs), typically defined by myeloid proliferation and eosinophilia, and are only rarely caused by platelet-derived growth factor receptor beta (PDGFRB) gene rearrangements.

CASE PRESENTATION

Here, we report a unique case of MPN that is negative for eosinophilia and characterized by a novel PDGFRB rearrangement. After cytogenetic analysis revealed a karyotype of t(5;17) (q32;q11), we used fluorescence in situ hybridization to specifically identify the PDGFRB gene at 5q31-q33 as the gene that had been translocated. Subsequently, RNA sequencing identified a new MYO18A-PDGFRB gene fusion. This fusion presented a previously undescribed breakpoint composed of exon 37 of MYO18A and exon 13 of PDGFRB. Furthermore, both RT-PCR and Bi-directional Sanger sequencing confirmed this out-of-frame fusion. Interestingly, we simultaneously identified the presence of another three PDGFRB transcripts, all of which were in-frame fusions. After treating the patient with imatinib, the t(5;17) translocation was no longer detected by conventional cytogenetics or by FISH, and at the time of the last follow-up, the patient had been in complete remission for 26 months.

CONCLUSION

We prove that MYO18A-PDGFRB fusions are recurrent genetic aberrations involved in MPNs, and identify multiple fusion transcripts with novel breakpoints.

Orthorhombic BiFeO3

A new orthorhombic phase of the multiferroic BiFeO3 has been created via strain engineering by growing it on a NdScO(3)(110)(o) substrate. The tensile-strained orthorhombic BiFeO3 phase is ferroelectric and antiferromagnetic at room temperature. A combination of nonlinear optical second harmonic generation and piezoresponse force microscopy revealed that the ferroelectric polarization in the orthorhombic phase is along the in-plane {110}(pc) directions. In addition, the corresponding rotation of the antiferromagnetic axis in this new phase was observed using x-ray linear dichroism.

A strain-driven morphotropic phase boundary in BiFeO3

Piezoelectric materials, which convert mechanical to electrical energy and vice versa, are typically characterized by the intimate coexistence of two phases across a morphotropic phase boundary. Electrically switching one to the other yields large electromechanical coupling coefficients. Driven by global environmental concerns, there is currently a strong push to discover practical lead-free piezoelectrics for device engineering. Using a combination of epitaxial growth techniques in conjunction with theoretical approaches, we show the formation of a morphotropic phase boundary through epitaxial constraint in lead-free piezoelectric bismuth ferrite (BiFeO3) films. Electric field-dependent studies show that a tetragonal-like phase can be reversibly converted into a rhombohedral-like phase, accompanied by measurable displacements of the surface, making this new lead-free system of interest for probe-based data storage and actuator applications.

Evidence for an oncogenic role of AHI-1 in Sezary syndrome, a leukemic variant of human cutaneous T-cell lymphomas

Ahi-1 (Abelson helper integration site 1) is a novel gene frequently activated by provirus insertional mutagenesis in murine leukemias and lymphomas. Its involvement in human leukemogenesis is demonstrated by gross perturbations in its expression in human leukemia cells, particularly in cutaneous T-cell lymphoma cell lines where increases in AHI-1 transcripts of 40-fold are seen. To test directly whether deregulated expression of AHI-1 contributes to their transformed properties, knockdown of AHI-1 expression in Hut78 cells, a cell line derived from a patient with Sezary syndrome (SS), was performed using retroviral-mediated RNA interference. Retroviral-mediated suppression specifically inhibited expression of AHI-1 and its isoforms in transduced cells by 80% and also reduced autocrine production of interleukin (IL)-2, IL-4 and tumor necrosis factor-alpha (TNFalpha) by up to 85%. It further significantly reduced their growth factor independence in vitro and the ability to produce tumors in immunodeficient mice. Interestingly, aberrant expression of AHI-1, particularly truncated isoforms, was present in CD4+CD7- Sezary cells from some patients with SS. Elevated expression of IL-2 and TNFalpha was also found in these cells. These findings provide strong evidence of the oncogenic activity of AHI-1 in human leukemogenesis and demonstrate that its deregulation may contribute to the development of SS.

Spectroscopic study of dinitrophenol herbicide sorption on smectite

Sorption of two dinitrophenolic herbicides, 4,6-dinitro-o-cresol (DNOC) and 4,6-dinitro-2-sec-butylphenol (DINOSEB) to smectite was studied using FTIR, HPLC, and quantum chemical methods. The high affinity of DNOC and DINOSEB for smectite surfaces was attributed to site-specific interactions with exchangeable cations and nonspecific van der Waals interactions with the siloxane surface. The positions of the nu(asym)(NO) and nu(sym)(NO) vibrational modes were perturbed by the exchangeable cations with similar changes occurring for both alkali and alkaline earth cations as a function of ionic potential. The cation-induced changes to the vibrational bands of the NO2 groups indicate that exchangeable metal cations are coordinated to -NO2 groups. Quantum chemical methods predicted a red-shift of the nu(asym)(NO) band and a corresponding blue-shift of the nu(sym)(NO) modes, as was observed experimentally. The nature of the smectite surface itself did not strongly influence the vibrational modes of sorbed DNOC or DINOSEB on the basis of a comparison of DNOC sorbed to three different smectites (K-SWy-2, K-SAz-1, and K-SHCa-1). FTIR spectra of DNOC and DINOSEB sorbed to a K-SWy-2 smectite were studied quantitatively using a modified form of Beers law. The FTIR-derived sorption isotherm of DNOC sorbed to K-SWy-2 was in good agreement with the isotherm derived from HPLC measurements. The molar absorptivity value of DNOC sorbed to K-SWy-2 smectite was 1.43 x 10(7) cm2/mol in good agreement with literature values for nitroaromatics (average value of 1.72 x 10(7) +/- 0.3 cm2/mol). On the basis of this value, the limit of detection using the FTIR method of approximately 5 microgDNOC g(clay) was determined. These two observations (sorption isotherms and molar absorptivity) provide a direct link between the macroscopic sorption results and the FTIR spectra.

Spectroscopic study of nitroaromatic-smectite sorption mechanisms

Sorption mechanisms of 1,3- and 1,4-dinitrobenzene, 1,3,5-trinitrobenzene (TNB), dinitro-o-creasol, and 6-sec-butyl-2,4-dinitrophenol (DINOSEB) on smectite were investigated using FTIR spectroscopy and HPLC methods. A quantitative method was developed that established a direct link between the HPLC and the FTIR data. Freundlich sorption values ranged from 47 (L g(-1)) for 1,3,5-TNB to 3.7 for DINOSEB and showed that the extent of nitroaromatic compounds (NAC) sorption was strongly dependent on the number and position of the nitro substituents as well as other substituents and steric effects. The amount of 1,3,5-TNB sorbed to smectite was strongly influenced by the nature of the exchangeable cation. Furthermore, the exchangeable cation significantly influenced the positions and relative intensities of the vibrational modes of the -NO2 groups. The strongest perturbations were observed for cations with lower enthalpies of hydration (e.g., K+) and included a red shift of the v(asym)(NO) band, a concomitant blue shift of the v(sym)(NO) band. These changes were accompanied by a 2-fold increase in the relative intensity of the v(asym)(NO) band relative to the intensity of the v(sym) (NO) band. Molecular quantum mechanics calculations were used to rationalize frequency shifts in terms of nitroaromatic interactions with interlayer cations. Results indicate that the sorption of NACs to smectite surfaces is controlled largely by the hydration characteristics of the exchangeable cation, which regulates both cation-nitroaromatic complexation and swelling of the smectite.

Mechanisms for the adsorption of substituted nitrobenzenes by smectite clays

To more fully understand the potential for transport of nitroaromatic compounds in soils and subsoils,the adsorption of a series of para- and meta-substituted nitrobenzenes (SNBs) by K-smectite clay was measured. Adsorption isotherms were fit to the Freundlich equation, and the resultant Freundlich adsorption coefficients (log(Kf) were positively correlated with the Hammett substituent constant (r2 = 0.80). This relationship and a positive reaction constant (p = 1.15) indicate that the adsorption reaction is favored by electron-withdrawing substituents. These results are consistent with an electron donor (smectite)-acceptor (substituted nitrobenzene) mechanism offered previously. However, quantum calculations did not reveal any systematic relationship between the Hammett constant and the electron density on the aromatic ring, which would explain a donor-acceptor relationship. Rather, electron density donated by a second substituent on nitrobenzene appears to be appropriated by the nitro group leaving ring electron density unchanged. Fourier transform infrared spectroscopy revealed shifts in the -NO2 vibrational modes of 1,3,5-trinitrobenzene (TNB) upon adsorption to K+-smectite that were consistent with the complexation of K+ by -NO2 groups. Such TNB vibrational shifts were not observed for SWy-1 saturated with more strongly hydrated cations (i.e., Na+, Mg2+, Ca2+, and Ba2+). The simultaneous interaction of multiple -NO2 groups with exchangeable K+ was indicated by molecular dynamic simulations. Adsorption of SNBs by smectite clays appears to result from the additive interactions of -NO2 groups and secondary substituents with interlayer K+ ions. Adsorption occurs to a greater or lesser extent depending on the abilities of substituents to complex additional interlayer cations and the water solubilities of SNBs. We conclude that the adsorption trends of SNBs on K-SAz-1 can be explained without recourse to hypothetical electron donor-acceptor complexes.

Potential contributions of smectite clays and organic matter to pesticide retention in soils

Soil organic matter (SOM) is often considered the dominant sorptive phase for organic contaminants and pesticides in soil-water systems. This is evidenced by the widespread use of organic-matter-normalized sorption coefficients (K(OM)) to predict soil-water distribution of pesticides, an approach that ignores the potential contribution of soil minerals to sorption. To gain additional perspective on the potential contributions of clays and SOM to pesticide retention in soils, we measured sorption of seven pesticides by a K-saturated reference smectite clay (SWy-2) and SOM (represented by a muck soil). In addition, we measured the adsorption of atrazine by five different K-saturated smectites and Ca-saturated SWy-2. On a unit mass basis, the K-SWy-2 clay was a more effective sorbent than SOM for 4,6-dinitro-o-cresol (DNOC), dichlobenil, and carbaryl of the seven pesticides evaluated, of which, DNOC was sorbed to the greatest extent. Atrazine was sorbed to a similar extent by K-SWy-2 and SOM. Parathion, diuron, and biphenyl were sorbed to a greater extent by SOM than by K-SWy-2. Atrazine was adsorbed by Ca-SWy-2 to a much lesser extent than by K-SWy-2. This appears to be related to the larger hydration sphere of Ca(2+) (compared to that of K(+)) which shrinks the effective size of the adsorption domains between exchangeable cations, and which expands the clay layers beyond the apparently optimal spacing of approximately 12.2 A for sorption of aromatic pesticide structures. Although a simple relation between atrazine adsorption by different K-smectites and charge properties of clay was not observed, the highest charge clay was the least effective sorbent; a higher charge density would result in a loss of adsorption domains. These results indicate that for certain pesticides, expandable soil clays have the potential to be an equal or dominant sorptive phase when compared to SOM for pesticide retention in soil.

Sorption and cosorption of organic contaminant on surfactant-modified soils

Three kinds of soils were modified with the cationic surfactants, hexadecyltrimethylammonium (HDTMA) bromide and tetramethylammonium (TMA) bromide to increase their sorptive capabilities. Sorption of chlorobenzene in simulated groundwater by these soils was investigated. HDTMA-modified soil has a higher ability to sorb chlorobenzene from simulated groundwater than unmodified soil. TMA-modified soil did not show the superiority. HDTMA thus can be used to modify soil to improve its sorption capability. Cosorption of chlorobenzene in simulated groundwater in the absence or presence of nitrobenzene and dichloromethane on HDTMA-modified soil was also investigated. Nitrobenzene facilitated sorption of chlorobenzene on all HDTMA-modified soil. Dichloromethane did not influence the sorption of chlorobenzene by HDTMA-modified soil. The results suggest that HDTMA-modified soil is a highly effective sorbent for chlorobenzene and multiple organic compounds did not impede the uptake of chlorobenzene.

A partition-limited model for the plant uptake of organic contaminants from soil and water

In dealing with the passive transport of organic contaminants from soils to plants (including crops), a partition-limited model is proposed in which (i) the maximum (equilibrium) concentration of a contaminant in any location in the plant is determined by partition equilibrium with its concentration in the soil interstitial water, which in turn is determined essentially by the concentration in the soil organic matter (SOM) and (ii) the extent of approach to partition equilibrium, as measured by the ratio of the contaminant concentrations in plantwater and soil interstitial water, alphapt (< or = 1), depends on the transport rate of the contaminant in soil water into the plant and the volume of soil water solution that is required for the plant contaminant level to reach equilibrium with the external soil-water phase. Through reasonable estimates of plant organic-water compositions and of contaminant partition coefficients with various plant components, the model accounts for calculated values of alphapt in several published crop-contamination studies, including near-equilibrium values (i.e., alphapt approximately equals 1) for relatively water-soluble contaminants and lower values for much less soluble contaminants; the differences are attributed to the much higher partition coefficients of the less soluble compounds between plant lipids and plant water, which necessitates much larger volumes of the plant water transport for achieving the equilibrium capacities. The model analysis indicates that for plants with high water contents the plant-water phase acts as the major reservoir for highly water-soluble contaminants. By contrast, the lipid in a plant, even at small amounts, is usually the major reservoir for highly water-insoluble contaminants.

[Analysis of toxic organic compounds in MGP-Wastewater and investigation of Wastewater's general characteristics]

A full-scale investigation and analysis of MGP(Manufacture Gas from Petroleum)-Wastewater was carried out in this study. It's the first time that this paper publicizes the wastewater's general data, pretreatment method of GC/MS analysis and compositions of toxic organic compounds. The concentrtion of wastewater's CODCg, BOD5, phenolic, N-NH4+ and extractive-organic is: 400 mg.L(-1)-600 mg.L-1, 60 mg.L(-1)-80 mg.L-1, 20 mg.L(-1)-30 mg.L-1, 60 mg.L(-1)-80 mg.L-1 and 170 mg.L(-1)-200 mg.L-1 respectively. There are 79 kinds of aromatic compounds were detected by GC/MS, the total concentration of influent and effluent is 140.79 mg.L-1 and 129.11 mg.L-1 respectively. The data approved that MGP-wastewater is toxic and difficult for bio-treatment.

Deposition record of organochlorine pesticides in a sedimentary core in Macao Estuary, Pearl River, China

This paper present the concentration profiles of the organochlorine pesticides in a sediment core from Macao Estuary, Pearl River, China. Concentrations of organochlorine pesticides were determined by GC/ ECD and GC/MSD, and the core was dated by 210Pb method in a content-activity model. The results show that the concentrations of HCHs and DDTs in the core ranged from 0.48-26.3 and 1.92-39.1 microg/kg, respectively. Concentration of DDTs in the research area was above the Effects Range-Low value (ERL) for Marine and Estuarine sediments. The vertical distributing of organochlorine pesticides in the core was influenced by the water flux of Pearl River and the pollutants are mainly attributed to the runoff of local agricultural soils.

[Vertical distribution characteristics of organochlorinated pesticides in sediment core from Macao estuary, Pearl River delta]

This work presents the analysis result of concentration for organochlorinated pesticides in a sedimentary core sample. Pesticides were quantified by GC/ECD with the internal standard material. The core dated by 210Pb methods. The vertical distribution of pesticides concentration with the depth was discussed. The results showed the concentration of BHCs and DDTs in the core ranged from 0.48 ng/g to 26.28 ng/g and 1.92-39.13 ng/g respectively. The distributing characteristics of organochlorinated pesticides in the core varied with the water fluxes of Pearl River. Organochlorinated pesticides may come from the residue of agricultural soils. Concentration of DDTs was above the effects range-low value for marine and estuarine sediments.

Determination of porphyrin carbon isotopic composition using gas chromatography-isotope ratio monitoring mass spectrometry

Carbon isotopic compositions of aetio I occurring in the form of free-base, nickel, demetallation, dihydroxysilicon(IV) and bis(tert.-butyldimethylsiloxy)silicon(IV) [(tBDMSO)2Si(IV)] have shown that it has experienced no obvious isotope fractionation during the synthesis of [(tBDMSO)2Si(IV)] porphyrin from aetio I. Here, aetio I porphyrin species such as free-base, nickel, demetallated and dihydroxysilicon were analyzed by the conventional method, namely it is combusted in sealed system, and followed by isotope ratio monitoring mass spectrometric analysis. [(tBDMSO)2Si(IV)] aetio I was assayed by gas chromatography-isotope ratio monitoring mass spectrometry (GC-IRMS). A porphyrin mixture of [(tBDMSO)2Si(IV)] aetio I and octaethylporphyrin was also prepared. Their carbon isotopic compositions measured by GC-IRMS indicate that no isotope exchange took place between the porphyrins during the synthesis of [(tBDMSO)2Si(IV)] porphyrins. This method is employed for delta13C determination of geoporphyrins from the Maoming and Jianghan oil shales.

Influence of modified soils on the removal of diesel fuel oil from water and the growth of oil degradation micro-organism

Three soils were modified with two kinds of cationic surfactants in order to increase their sorptive capabilities for organic contaminants. Sorption of diesel fuel oil in water by these modified soils had been investigated. Modified soils can effectively sorb diesel fuel oil from water. The sorption capability of modified soils is: HDTMA-black soil > HDTMA-yellow brown soil > HDTMA-red soil > TMA-black soil > TMA-yellow brown soil > TMA-red soil. Sorption of diesel fuel oil by natural soils and HDTMA modified soils is via partition, the sorption isotherms can be expressed by Henry equation, and logK(SOM) is 2.42-2.80, logK(HDTMA) is 3.37-3.60. Sorption isotherms of TMA modified soils can be expressed by Langmuir equation, the saturation sorption capacities are 1150 (TMA-black soil), 750 (TMA-yellow-brown soil), 171 mg/kg (TMA-red soil), respectively. A diesel fuel oil degradation micro-organism (Pseudomonas sp.) was isolated in the lab. To test the influence of the modified soils on the micro-organism, various growth curves of Pseudomonas in different conditions were drawn. Pseudomonas can grow very well with natural soils and TMA modified soils. The acclimation period of Pseudomonas is reduced. As to HDTMA modified soils, HDTMA loading amount is very important. When HDTMA loading amount is no higher than 0.5 CEC, the micro-organism can grow very well after a long acclimation period.

Fullerenes-extracted soot: a new adsorbent for collecting volatile organic compounds in ambient air

Fullerenes-extracted soot (FES) is the by-product of fullerenes production. Retention characteristics at different temperatures for 17 volatile organic compounds (VOCs) on FES are measured. The adsorption and desorption efficiencies for VOCs on FES adsorbent tubes range from 40.8 to 117%, most of them being 100+/-20%. The values are compared with Tenax GR, an adsorbent commonly used in environmental analysis. FES can be used as an adsorbent of low cost to collect VOCs in environmental samples.

Gata2 and Gata3: novel markers for early embryonic polarity and for non-neural ectoderm in the chick embryo

We have investigated in detail the expression patterns of two Gata genes, cGata2 and cGata3, during early chick development. In addition to confirming previously described expression of these two genes in developing brain, kidney and blood islands, this study reveals several important novel expression domains during very early stages of development. cGata2 is expressed in the area opaca in pre-primitive streak stages, forming a gradient along the A-P axis (strongest anteriorly). Both genes are expressed strongly in the entire non-neural ectoderm from stage 4+, and neither is expressed in prospective neural plate at any stage. Unlike other previously described non-neural markers, neither gene is expressed in the dorsal neural tube. We also describe dynamic expression of cGata2 and cGata3 during eye, ear and gut development.

Liquid-Saturated Hydrocarbons Resulting from Pyrolysis of the Marine Coccolithophores Emiliania huxleyi and Gephyrocapsa oceanica

: Two nanoplanktonic marine coccolithophores, Emiliania huxleyi and Gephyrocapsa oceanica, were grown at 23 degrees C with a 16-hour light and 8-hour darkness regimen. The cells were dried at room temperature and then subjected to pyrolysis at 100 degrees to 500 degrees C under anoxygenic conditions to produce hydrocarbons. Temperature-dependent profiles of the liquid-saturated hydrocarbons (saturates) produced during pyrolysis were very similar for the two strains, although the total amount was higher in E. huxleyi than in G. oceanica. The amount of saturates produced was only 0.05% to 0.15% below 200 degrees C, but about 2.1% to 2.8% at 300 degrees C. Their major components were normal alkanes in a series ranging from nC(11) to nC(35) with the predominant peak at nC(15). At 400 degrees and 500 degrees C most of saturates transformed into gaseous compounds. The major saturates identified in all pyrolysates were normal C(31) monounsaturated and diunsaturated alkenes, a series of normal alkanes, phytenes, C(28) sterenes, and steranes. Profiles of saturates in gas chromatography-mass spectroscopy varied with increasing pyrolysis temperature and also differed between E. huxleyi and G. oceanica. The two coccolithophores are useful candidates for the production of renewable liquid fuel through pyrolysis-especially E. huxleyi, which has higher production. The results also provide information for further studies on the characterization, source, and paleogeographic distribution of marine sediment.

Study on immunoregulation by interleukin-1 receptor antagonist in NZB/W F mice

The immunoregulating effect of Interleukin-1-receptor antagonist (IL-1ra) in lupus-like NZB/W F1 mice was investigated to find possible approach to prevent lupus nephritis. 12 female NZB/W F1 mice of 13 weeks were randomly divided into 2 groups. Each mouse in the treated group was intraperitoneally injected with IL-1ra once every 2 weeks for 3 times at the dosage of 100 micrograms each time, while the control group was given injection of 0.1 ml normal saline. All the mice were killed at the age of 9 months and the immunologic function was examined. Results showed that this dosage could not completely prevent the development of lupus nephritis, but the renal damage was alleviated and the urine protein was decreased. Moreover, it could improve the immunofunction by significantly reducing the levels of serum IL-1 and obviously increase the activities of NK cells and IL-2 induced by ConA in mononuclear cells of spleen. There was no significant difference in the levels of serum IL-6 and TNF-alpha between the treated group and control group. It is concluded that IL-1ra has certain regulatory effect on the immunologic function of lupus-like NZB/W F1 mice.

Modular organization of Pax/homeodomain proteins in transcriptional regulation

Specificity in transcriptional regulation lies in a large part in the specificity of DNA binding by transcription factors. One group of transcription factors which are of great interest for studying transcriptional specificity is the Pax/Homeodomain (Pax/HD) proteins which contain two conserved DNA binding domains, a paired domain (PD) and a Paired-class homeodomain (HD). The Pax/HD proteins can bind to at least three types of specific DNA sequences: the PD binding sites, the dimeric HD binding sites and a composite HD and PD binding site. We propose that Pax/HD proteins regulate different subsets of their target genes through modular binding to one of these three specific sequences. We show that, in a tissue culture system, a member of the Pax/HD family, Paired, is able to activate transcription after binding through either its PD or its HD. The transactivation mediated by one domain does not require DNA binding of the other domain. Furthermore, binding sites specific for the PD of Paired are sufficient to mediate embryonic expression of a reporter gene in a paired-like pattern. The expression of the reporter gene is dependent on wild type paired function and, in a prd mutant background, it can be rescued by an exogenous paired gene encoding a protein whose HD is not able to bind to DNA. Finally, we show that the Paired protein uses differently its C-terminal activation domain when transactivation is mediated through its PD or its HD. These results and recent evidence from other Pax/HD proteins strongly suggest that this class of proteins is able to achieve specific and modular transcriptional regulation through its multiple DNA binding domains.

Direct regulation of rhodopsin 1 by Pax-6/eyeless in Drosophila: evidence for a conserved function in photoreceptors

Pax-6 is a transcription factor containing both a homeodomain (HD) and a Paired domain (PD). It functions as an essential regulator of eye development in both Drosophila and vertebrates, suggesting an evolutionarily conserved origin for different types of metazoan eyes. Classical morphological and phylogenetic studies, however, have concluded that metazoan eyes have evolved many times independently. These apparently contradictory findings may be reconciled if the evolutionarily ancient role of Pax-6 was to regulate structural genes (e.g., rhodopsin) in primitive photoreceptors, and only later did it expand its function to regulate the morphogenesis of divergent and complex eye structures. In support of this, we present evidence that eyeless (ey), which encodes the Drosophila homolog of Pax-6, directly regulates rhodopsin 1 (rh1) expression in the photoreceptor cells. We detect ey expression in both larval and adult terminally differentiated photoreceptor cells. We show that the HD of Ey binds to a palindromic HD binding site P3/RCS1 in the rh1 promoter, which is essential for rh1 expression. We further demonstrate that, in vivo, P3/RCS1 can be replaced by binding sites specific for the PD of Ey. P3/RCS1 is conserved in the promoters of all Drosophila rhodopsin genes as well as in many opsin genes in vertebrates. Mutimerized P3 sites in front of a basal promoter are able to drive the expression of a reporter gene in all photoreceptors. These results suggest that Pax-6/Ey directly regulates rhodopsin 1 gene expression by binding to the conserved P3/RCS1 element in the promoter.

A new rhodopsin in R8 photoreceptors of Drosophila: evidence for coordinate expression with Rh3 in R7 cells

The photoreceptor cells of the Drosophila compound eye are precisely organized in elementary units called ommatidia. The outer (R1-R6) and inner (R7, R8) photoreceptors represent two physiologically distinct systems with two different projection targets in the brain (for review see Hardie, 1985). All cells of the primary system, R1-R6, express the same rhodopsin and are functionally identical. In contrast, the R7 and R8 photoreceptors are different from each other. They occupy anatomically precise positions, with R7 on top of R8. In fact, there are several classes of R7/R8 pairs, which differ morphologically and functionally and are characterized by the expression of one of two R7-specific opsins, rh3 or rh4. Here, we describe the identification of a new opsin gene, rhodopsin 5, expressed in one subclass of R8 cells. Interestingly, this subclass represents R8 cells that are directly underneath the R7 photoreceptors expressing rh3, but are never under those expressing rh4. These results confirm the existence of two subpopulations of R7 and R8 cells, which coordinate the expression of their respective rh genes. Thus, developmental signaling pathways between R7 and R8 lead to the exclusive expression of a single rhodopsin gene per cell and to the coordinate expression of another one in the neighboring cell. Consistent with this, rh5 expression in R8 disappears when R7 cells are absent (in sevenless mutant). We propose a model for the concerted evolution of opsin genes and the elaboration of the architecture of the retina.

In vivo requirement for the paired domain and homeodomain of the paired segmentation gene product

The Drosophila pair-rule gene paired is required for the correct expression of the segment polarity genes wingless, engrailed and gooseberry. It encodes a protein containing three conserved motifs: a homeodomain (HD), a paired domain (PD) and a PRD (His/Pro) repeat. We use a rescue assay in which paired (or a mutated version of paired in which the functions of the conserved motifs have been altered) is expressed under the control of its own promoter, in the absence of endogenous paired, to dissect the Paired protein in vivo. We show that both the HD and the N- terminal subdomain of the PD (PAI domain) are absolutely required within the same molecule for normal paired function. In contrast, the conserved C-terminal subdomain of the PD (RED domain) appears to be dispensable. Furthermore, although a mutation abolishing the ability of the homeodomain to dimerize results in an impaired Paired molecule, this molecule is nonetheless able to mediate a high degree of rescue. Finally, a paired transgene lacking the PRD repeat is functionally impaired, but still able to rescue to viability. We conclude that, while Prd can use its DNA-binding domains combinatorially in order to achieve different DNA-binding specificities, its principal binding mode requires a cooperative interaction between the PAI domain and the homeodomain.

Conservation and diversification in homeodomain-DNA interactions: a comparative genetic analysis

Nearly all metazoan homeodomains (HDs) possess DNA binding targets that are related by the presence of a TAAT sequence. We use an in vitro genetic DNA binding site selection assay to refine our understanding of the amino acid determinants for the recognition of the TAAT site. Superimposed upon the conserved ability of metazoan HDs to recognize a TAAT core is a difference in their preference for the bases that lie immediately 3' to it. Amino acid position 50 of the HD has been shown to discriminate among these base pairs, and structural studies have suggested that water-mediated hydrogen bonds and van der Waals contacts underlie for this ability. Here, we show that each of six amino acids tested at position 50 can confer a distinct DNA binding specificity.

Effects of zaizhang-I, a traditional Chinese medicine, on immunologically mediated aplastic anemia in mice

Immunologically mediated aplastic anemia in mice were used as animal models to study the the curative effect of Zaizhang-I in term of the changes of two pathogenetic aspects in aplastic mice, namely the deficiency of hematopoietic stem cells and the disturbance of immunology. Our results demonstrated that in aplastic mice, after treatment by Zaizhang-I, the loss of mature hematopoietic cells (WBC, RBC, Plt) were reduced, and marrow cellular cytosis, and their clinical findings were improved, indicating a partial remission. The present data show that its curative mechanism lies in the action of promoting the recovery of colony forming unit-spleen (CFU-S) and reversing immunologically-induced plasma colony forming unit granulocyte/macrophage (CFU-GM) inhibitory activity. Natural killer cells activity (Nka) and interleukin-2, tumor necrosis factors (TNF) were also so examined to further understand the mechanism by which Zaizhang-I reverse plasma hematopoietic activity.

Cooperative dimerization of paired class homeo domains on DNA

Homeo domain-containing proteins mediate many transcriptional processes in eukaryotes. Because nearly all animal homeo proteins are believed to bind to short, highly related DNA sequences, the basis for their high specificity of action is not understood. We show that cooperative dimerization on palindromic DNA sequences can provide increased specificity to one of the three major classes of homeo domains, the Paired/Pax class. The 60-amino-acid homeo domains from this class contain sufficient information to bind cooperatively as homo- and heterodimers to palindromic DNA sequences; that is, the binding of one homeo domain molecule can increase the affinity of a second molecule by up to 300-fold. Different members of the Paired (Prd) class of homeo domains prefer different spacings between half-sites, as determined by the ninth amino acid residue of the recognition helix. In addition, this residue determines the identity of the base pairs at the center of the palindromic sites, as well as the magnitude of the cooperative interaction. The cooperative dimerization of homeo domains in the Prd class distinguishes them from other classes, whereas binding-site configuration and sequence specificity allow for distinctions within this class.