Microsyringe-based slug-flow microextraction for rapid and accurate determination of antibiotics in highly saline seawater.

BACKGROUND: Extensive use of antibiotics leads to widespread environmental pollution, endangering ecosystems, and human health. It is particularly concerning, posing global threats requiring urgent attention and action. In this regard, the shift to mass spectrometry in determining antibiotics is highly desirable. Significant progress has been made in analyzing and optimizing the sensitivity of high-salt samples. However, the persistence of cumbersome operational procedures presents a significant challenge to this shift. Thus, the persistence of complex operational procedures needs to be addressed. RESULTS: In this study, a rapid and direct method for determining antibiotics in highly saline environmental water samples using microsyringe-based slug-flow microextraction (MSFME)-droplet spray ionization (DSI) mass spectrometry (MS) has been described. The proposed method successfully detected clarithromycin, ofloxacin, and sulfadimidine in seawater within a linear range of 1-1200 ng mL-1, with low limits of detection of 0.19 ng mL-1, 0.17 ng mL-1, and 0.20 ng mL-1, respectively (Signal/Noise = 3). Additionally, spiked real seawater samples of all three antibiotics demonstrated satisfactory recoveries (95.1-107.5%) and precision (RSD≤8.8%). The MSFME-treated high-salt sample (3.5 wt%) showed a mass spectral response intensity 4-5 orders of magnitude higher than the untreated medium-salt sample (0.35 wt%). Furthermore, exploration of the applicability of MSFME showed that it is suitable not only for high-salinity (3.5 wt%) samples but also for salt-free or low-salt and hard water samples rich in calcium and magnesium ions. SIGNIFICANCE: Comparisons with other methods, complex laboratory setups for sample processing are now simplified to a single step, completing the entire process, including desalination and detection, MSFME-DSI-MS provides faster results in less than 1 min while maintaining sensitivity comparable to that of other detection methods. In conclusion, this advancement provides an exceptionally simplified protocol for the rapid, highly sensitive, and quantitative determination of antibiotics in environmental water samples.

One-step online analysis of antibiotics in highly saline seawater by nano-based slug-flow microextraction.

The transition to mass spectrometry (MS) in the analysis of antibiotics in the marine environment is highly desirable, particularly in the enhancement of sensitivity for high-salinity (3.5 wt%) seawater samples. However, the persistence of complex operational procedures poses substantial challenges to this transition. In this study, a rapid method for the online analysis of antibiotics in seawater samples via nano-electrospray ionization (nESI) MS based on slug-flow microextraction (SFME) has been proposed. Comparisons with other methods, complex laboratory setups for sample processing are now seamlessly integrated into a single online step, completing the entire process, including desalination and detection, SFME-nESI-MS provides faster results in less than 2 min while maintaining sensitivity comparable to that of other detection methods. Using SFME-nESI, six antibiotics in high-salinity (3.5 wt%) seawater samples have been determined in both positive and negative ion modes. The proposed method successfully detected clarithromycin, ofloxacin, and sulfadimidine in seawater within a linear range of 1-1000 ng mL-1 and limit of detection (LOD) of 0.23, 0.06, and 0.28 ng mL-1, respectively. The method recovery was from 92.8% to 107.3%, and the relative standard deviation was less than 7.5%. In addition, the response intensity of SFME-nESI-treated high-salinity (3.5 wt%) samples surpassed that of untreated medium-salinity (0.35 wt%) samples by two to five orders of magnitude. This advancement provides an exceptionally simplified protocol for the online rapid, highly sensitive, and quantitative determination of antibiotics in high-salinity (3.5 wt%) seawater.

[Research Progress of FLT3 Mutation in Acute Myeloid Leukemia --Review].

Acute myeloid leukemia (AML) is a heterogeneous hematopoietic tumor originated from hematopoietic stem cells. FLT3 is an important receptor tyrosine kinase in cell signal transduction pathway and one of the common mutated genes in AML. AML patients with FLT3-ITD mutation have a poor prognosis and tendency to relapse. Therefore, early identification of FLT3 gene mutation and selection of appropriate treatment are particularly important. Currently, the small moleculetargeted drugs have been new treatment methods for AML patients with FLT3-ITD mutation, but accompanied drug resistance need to be solved. This paper reviews the mechanism of FLT3 mutation, the clinical significance of FLT3 mutation in AML, FLT3 inhibitors and drug resistance mechanism.

First Description of Hb San Diego (HBB: c.328G>A) in a Chinese Family with Congenital Erythrocytosis.

Congenital erythrocytosis is a rare and hereditary disorder of red blood cell (RBC) production that can be caused by high oxygen affinity hemoglobin (Hb) variants. We applied a genetic approach including whole exome sequencing and Sanger sequencing. We identified a heterozygous ß-globin gene (Hb San Diego or HBB: c.328G>A) in exon 3 as a causative germline mutation in a Chinese family with congenital erythrocytosis. We concluded that in erythrocytosis with a dominant inheritance and normal or inappropriately high erythropoietin (EPO) levels, the high oxygen affinity Hb variants should be considered. In addition, as a tool for identification of mutations in congenital erythrocytosis, whole exome sequencing improves diagnostic accuracy and provides the opportunity for discovery of novel variants.

[Research Progress on Ph-like Acute Lymphoblastic Leukemia--Review].

Ph-like acute lymphoblastic leukemia (ALL) is a high-risk subtype of precursor B-cell acute lymphoblastic leukemia (BCP-ALL) with a gene expression profile and a high frequency of IKZF1 gene alteration similar to that of Ph-positive ALL, which is a clinically and biologically heterogeneous subtype of BCP-ALL. The prognosis correlats negatively with age increasing. The incidence of this "Ph-like" subtype may be higher in young adults. Ph-like ALL is characterized by genetic alterations that activate cytokine receptor genes and kinase signaling pathways. Prospective studies are needed to determine if incorporation of tyrosine kinase inhibitor-targeting kinase alterations into intensive chemotherapy regimens will improve outcome of patients with Ph-like ALL. The research progress of Ph-like ALL is summarised in this review, including epidemiology, genetic alterations and treatment..

Synthesis and application of thiol-functionalized magnetic nanoparticles for studying interactions of epirubicin hydrochloride with bovine serum albumin by fluorescence spectrometry.

A novel method was developed for studying the interaction between epirubicin hydrochloride (EPI) and bovine serum albumin (BSA) by fluorescence spectrometry. Fe3 O4 magnetic nanoparticles (MNPs) synthesized and functionalized with thiol group were employed for the immobilization and separation of target BSA in reaction solutions. The concentrations of the non-immobilized BSA and unbound EPI were obtained separately by fluorescence spectrometry. The binding constants (Ka ) and number of binding sites (n) of EPI with BSA were calculated. In this study, the Ka value was 5.05 × 105  L mol-1 , suggesting a strong binding of EPI to BSA, and the n value was 1.15. The effects of common metal ions on Ka of EPI with BSA were also investigated, and the results showed there was clearly bindings between the metal ions and BSA. The precise binding sites of EPI on BSA were determined as being in site I from the competitive displacement experiments. Copyright © 2016 John Wiley & Sons, Ltd.

Magnetic core/shell Fe3O4/Au nanoparticles for studies of quinolones binding to protein by fluorescence spectroscopy.

Magnetic core/shell Fe3O4/Au nanoparticles were used in the determination of drug binding to bovine serum albumin (BSA) using a fluorescence spectroscopic method. The binding constants and number of binding sites for protein with drugs were calculated using the Scatchard equation. Because of their superparamagnetic and biocompatible characteristics, magnetic core/shell Fe3O4/Au nanoparticles served as carrier proteins for fixing proteins. After binding of the protein to a drug, the magnetic core/shell Fe3O4/Au nanoparticles-protein-drug complex was separated from the free drug using an applied magnetic field. The free drug concentration was obtained directly by fluorescence spectrometry and the proteins did not influence the drug determination. So, the achieved number of binding sites should be reliable. The binding constant and site number for ciprofloxacin (CPFX) binding to BSA were 2.055 × 10(5) L/mol and 31.7, and the corresponding values for norfloxacin (NOR) binding to BSA were 1.383 × 10(5) L/mol and 38.8. Based on the achieved results, a suitable method was proposed for the determination of binding constants and the site number for molecular interactions. The method was especially suitable for studies on the interactions of serum albumin with the active ingredients of Chinese medicine.

[Clinical significance of detecting peripheral T cell subsets in children with leukemia].

This study was purposed to investigate the changes of peripheral blood T cells in children with acute leukemia at different stages and understand the immune status of children with leukemia. The CD4⁺, CD8⁺, CD4⁺/ CD8⁺ ratio, CD3⁺ and NK cells in 42 children with acute leukemia and 50 cases of normal children (as control group) were determined by flow cytometry at different periods after complete remission. The results showed that the CD3⁺ CD4⁺, CD8⁺ rate and CD4⁺/CD8⁺ ratio in newly diagnosed ALL and AML children were significantly lower than those in control group (P < 0.05). The NK cell count in newly diagnosed children with acute leukemia was significantly lower than that in control group (P < 0.05). Although the NK cell count in ALL and AML children gradually rose at 3, 6, 12 months after complete remission, but it still was statistically different from normal control group (P < 0.05). It is concluded that children with acute leukima have cellular immune disfunction at onset and during treatment, but the cell immune function gradually recovered after complete remission achieved. However, its recovery rate is slow. The results of this study can provided a basis for subsequently use of immunomodulations in leukemia children.

[Analysis of hematopoietic chimerism after non-myeloablative allogeneic peripheral blood stem cell transplantation].

The aim of this study was to analyze the hematopoietic chimerism after non-myeloablative allogeneic peripheral blood stem cell transplantation (NAPBSCT). 28 patients received NAPBSCT were evaluated. The conditioning regimen included FBC (fludarabine, busulphan, cyclophosphamide) +/- Ara-C. Peripheral blood was collected before and after transplantation in different periods. Semi-quantitative assessment of hematopoietic chimerism was performed by short tandem repeat-polymerase chain reaction (STR-PCR), polyacrylamide gel electrophoresis (PAGE) and silver staining, and analyzed by Image Analysis System. The results showed that on day 30 after transplantation, one patient failed to engraft, but 22 cases formed complete chimerism (CC) and 5 cases were of mixed chimerism. On day 7 after transplantation, the average percentage of donor cells was 74.71%. The time of dominance of the donor-specific allelic pattern preceded the recovery time of neutrophils and platelets. The incidence of aGVHD in group CC was significantly higher than that in group MC (P < 0.05). There was no significant difference in the incidence of cGVHD and disease relapse between group CC and group MC (P > 0.05). One patient relapsed in CC status without a transitional stage of MC. One patient with MC rejected grafts in early stage. 3 patients with MC transferred to CC and got complete remission after early implementation of therapy. It is concluded that sequential and quantitative detection of chimerism may be of great value to evaluate engraftment and to predict graft rejection, disease relapse and GVHD. Furthermore, it may provide a basis for early intervention treatment in the related complications.

[Advance of research on survivin in hematological malignancies--review].

Survivin a novel member of the inhibitor of apoptosis protein family, is overexpressed in most types of cancer but not in normal differentiated adult tissues. Its mRNA expression levels among hematogical malignancies are characteristic in each type, subtype and distinctive in different phases of disease, making it a reliable diagnostic marker for clinical stages. Recently, researches indicate that high levels of survivin expression are associated with a poor prognosis and may be involved in tumor resistance to multiple chemotherapeutic drugs. In addition, experiments demonstrate that leukemic vaccination with DC pulsed with survivin antigen in vitro inhibit the proliferation of leukemic cells. Furthermore, when transferred survivin antisense oligodeoxynucleotide or dominant-negative mutant survivin into, malignant cells can be induced apoptosis mediated by downregulation in survivin expression. These findings suggest that survivin may serve as a potential target for biological strategies against hematological neoplasms. This review focuses on expression of survivin in hematological malignancies, effects of survivin on drug-resistance and prognosis of hematological malignancies, and application of survivin in the treatment of hematological malignancies.