Copper Nanosheet-Based Wash-Free Fluorescence Imaging of Cancer Cells.

Near-infrared fluorescence (NIRF) probes greatly facilitate in vivo imaging of various biologically important species. However, there are several significant limitations such as consuming washing steps, photobleaching, and low signal intensity. Herein, we synthesized fluorescent copper nanosheets templated with DNA scaffolds (DNS/CuNSs). We employ them and Cy5.5 of the fluorescence resonance energy transfer (FRET) system, which have a larger Stokes shift (∼12-fold) than the traditional NIRF dye Cy5.5. Based on their excellent fluorescence properties, we employ DNS/CuNSs-Cy5.5 for fluorescence probes in cancer cell imaging. Compared with the free Cy5.5 fluorescence probe, the novel fluorescence imaging probe implements wash-free imaging and exhibits enhanced anti-photobleaching ability (∼5.5-fold). Moreover, the FRET system constructed by DNS/CuNSs has a higher signal amplification ability (∼4.17-fold), which is more similar to that of Cu nanoclusters prepared with DNA nanomonomers as a template. This work provides a new idea for cancer cell MCF-7 imaging and is expected to promote the development of cancer cell fluorescence imaging.

Effect of Spleen Aminopeptide Oral Lyophilized Powder and Fluticasone/salmeterol Powder Inhaler on Pulmonary Function and Incidence of Adverse Reactions in Children with Cough Variant Asthma.

Background: Cough variant asthma is a prevalent condition among children with chronic cough, significantly impacting their health and well-being. Objective: This study aimed to assess the impact of spleen aminopeptide oral lyophilized powder and fluticasone/salmeterol powder inhaler on pulmonary function and the incidence of adverse reactions in children with cough variant asthma. Methods: A total of 60 children with cough variant asthma admitted to the Pediatric Department of Cangzhou Central Hospital between July 2019 and June 2020 were enrolled in the study. Using the random number table method, they were assigned to either the observation group or the control group, with 30 cases in each group. The control group received treatment with fluticasone/salmeterol powder inhalers, while the observation group received a combination of fluticasone/salmeterol powder inhalers and spleen aminopeptide oral lyophilized powder. After 8 weeks of treatment, various clinical parameters, including forced vital capacity, forced expiratory volume per second/forced vital capacity, peak expiratory flow, fractional exhaled nitric oxide (FeNO), interleukin-4 (IL-4), IL-10, eosinophils in induced sputum, and serum CD4+ and CD8+ levels, were compared between the two groups. Results: The observation group exhibited a higher total effective rate of clinical efficacy compared to the control group [90.00% vs. 63.33%; OR (95% CI) 3.00 (1.01-8.92), P = .048)]. After 8 weeks, the observation group demonstrated higher levels of forced vital capacity, forced expiratory volume per second/forced vital capacity, peak expiratory flow [OR (95% CI) 0.48 (0.26-0.88), P = .017; OR (95% CI) 0.29 (0.14-0.57) 2.57 (1.46-4.52) 0.33 (0.16-0.70), P = .000, .001, .003], IL-10 [OR (95% CI) 0.29 (0.14-0.57), P = .000], and lower levels of FeNO [OR (95% CI) 0.48 (0.26-0.88), P = .017], IL-4, and eosinophils [OR (95% CI) 2.57 (1.46-4.52) 0.33 (0.16-0.70), P = .001, .003] compared to the control group (P < .05). Furthermore, the observation group exhibited higher levels of CD4+ and CD4+/CD8+ compared to the control group [OR (95% CI) 0.41 (0.25-0.67) 0.33 (0.20-0.56) 1.73 (1.18-2.55), P = .000, .000, .001]. Computed tomography measurements revealed significantly lower airway wall thickness, basement membrane thickness, and total airway wall area in the observation group compared to the control group [OR (95% CI) 0.18 (0.10-0.33) 0.23 (0.13-0.41) 0.28 (0.15-0.51), P = .000, .000, .000]. The incidence of adverse reactions did not significantly differ between the groups (6.67% vs. 3.33%; P > .05). Conclusion: The combination treatment of spleen aminopeptide oral lyophilized powder and fluticasone/salmeterol powder inhaler effectively improves lung function, FeNO levels, and airway inflammation, while enhancing cellular and humoral immune function in children with cough variant asthma. These findings have significant clinical implications and warrant further promotion and application of this treatment approach.

Micron-Scale Fabrication of Ultrathin Amorphous Copper Nanosheets Templated by DNA Scaffolds.

Two-dimensional (2D) amorphous materials could outperform their crystalline counterparts toward various applications because they have more defects and reactive sites and thus could exhibit a unique surface chemical state and provide an advanced electron/ion transport path. Nevertheless, it is challenging to fabricate ultrathin and large-sized 2D amorphous metallic nanomaterials in a mild and controllable manner due to the strong metallic bonds between metal atoms. Here, we reported a simple yet fast (10 min) DNA nanosheet (DNS)-templated method to synthesize micron-scale amorphous copper nanosheets (CuNSs) with a thickness of 1.9 ± 0.4 nm in aqueous solution at room temperature. We demonstrated the amorphous feature of the DNS/CuNSs by transmission electron microscopy (TEM) and X-ray diffraction (XRD). Interestingly, we found that they could transform to crystalline forms under continuous electron beam irradiation. Of note, the amorphous DNS/CuNSs exhibited much stronger photoemission (∼62-fold) and photostability than dsDNA-templated discrete Cu nanoclusters due to the elevation of both the conduction band (CB) and valence band (VB). Such ultrathin amorphous DNS/CuNSs hold great potential for practical applications in biosensing, nanodevices, and photodevices.

Molecular Characteristics of an NDM-4 and OXA-181 Co-Producing K51-ST16 Carbapenem-Resistant Klebsiella pneumoniae: Study of Its Potential Dissemination Mediated by Conjugative Plasmids and Insertion Sequences.

The carbapenem-resistant Klebsiella pneumoniae (CRKP) strain GX34 was recovered from the respiratory tract of an elderly male with severe pneumonia, and only susceptible to amikacin, tigecycline, and colistin. Complete genome suggested that it belonged to K51-ST16 and harbored plasmid-encoded NDM-4 and OXA-181, located on IncFIB plasmid GX34p1_NDM-4 and ColKP3/IncX3 plasmid GX34p4_OXA-181, respectively. A series of transconjugants generated in the plasmid conjugation assays, including Escherichia coli J53-N1 (harboring a self-transmissible and blaNDM-1-producing plasmid Eco-N-1-p), J53-N2 (harboring a blaNDM-4-producing plasmid and a helper plasmid GX34p5), and J53-O (harboring a blaOXA-181-producing plasmid), could be stably inherited after 10 days of serial passage and no significant biological fitness costs were detected. Furthermore, we first reported the blaNDM-1 gene, derived from blaNDM-4 mutation (460C>A) under meropenem pressure, could be in vitro transferred into a self-conjugative, recombined plasmid Eco-N-1-p of J53-N1. Eco-N-1-p was mainly recombined by GX34p4_OXA-181 (40,449 bp, 75.16%) and GX34p1_NDM-4 (8,553 bp, 15.89%), in which IS26 and IS5-like probably played a major role. Eco-N-1-p could be transferred into the conjugation recipient K. pneumoniae KP54 and make the latter sacrifice fitness. The retention rates of blaNDM-1 remained high stability (>80% after 200 generations). The comparative genomic analysis of GX34 and those carrying blaNDM-4 or blaOXA-181 genes retrieved from the NCBI RefSeq database showed all blaNDM-4 (26/26, 100.00%) and blaOXA-181 (13/13, 100.00%) were surrounded by IS26. The immediate environment of blaNDM-4 and blaOXA-181 in GX34 and some retrieved strains shared identical features, hinting at their possible dissemination. Effective measures should be taken to monitor the spread of this clone.

In vitro activity of cefiderocol, a siderophore cephalosporin, against carbapenem-resistant hypervirulent Klebsiella pneumoniae in China.

Cefiderocol is a siderophore cephalosporin that binds ferric iron and utilizes iron transporters to cross the cell membrane. Hypervirulent Klebsiella pneumoniae (hvKp) is known to produce more siderophores; in this case, the uptake of cefiderocol may be decreased. Therefore, the objective of this study was to evaluate the in vitro activity of cefiderocol against hvKp isolates. A total of 320 carbapenem-resistant K. pneumoniae (CRKp) isolates were collected in China between 2014 and 2022, including 171 carbapenem-resistant hvKp (CR-hvKp) and 149 carbapenem-resistant classical K. pneumoniae (CR-cKp). Quantitative detection of siderophores showed that the average siderophore production of CR-hvKp (234.6 mg/L) was significantly higher than that of CR-cKp (68.9 mg/L, P < 0.001). The overall cefiderocol resistance rate of CR-hvKp and CR-cKp was 5.8% (10/171) and 2.7% (4/149), respectively. The non-susceptible rates of both cefiderocol and siderophore production of CR-hvKp isolates were higher than those of CR-cKp in either NDM-1- or KPC-2-producing groups. The MIC90 and MIC50 for CR-hvKp and CR-cKp were 8 mg/L and 2 mg/L and 4 mg/L and 1 mg/L, respectively. The cumulative cefiderocol MIC distribution for CR-hvKp was significantly lower than that of CR-cKp isolates (P = 0.003). KL64 and KL47 consisted of 53.9% (83/154) and 75.7% (53/70) of the ST11 CR-hvKp and CR-cKp, respectively, and the former had significantly higher siderophore production. In summary, cefiderocol might be less effective against CR-hvKp compared with CR-cKp isolates, highlighting the need for caution regarding the prevalence of cefiderocol-resistant K. pneumoniae strains, particularly in CR-hvKp isolates.

Self-assembly Induced Enhanced Electrochemiluminescence of Copper Nanoclusters Using DNA Nanoribbon Templates.

Copper nanoclusters (CuNCs) are attractive electrochemiluminescence (ECL) emitters as Cu is comparatively inexpensive, nontoxic, and highly abundant. However, their ECL yield is relatively low. Herein, we report that orderly self-assembly of CuNCs using DNA nanoribbon as the template (DNR/CuNCs) conferred the CuNCs with improved ECL properties compared with individual CuNCs in both annihilation and co-reactant processes. The DNR/CuNCs resulted in a high ECL yield of 46.8 % in K2 S2 O8 , which was ≈68 times higher than that of individual CuNCs. This strategy was successfully extended to other ECL emitters, such as gold nanoclusters and the Ru(bpy)3 2+ /TPrA system. Furthermore, as an application of DNR/CuNCs, a DNR/CuNC-based ECL biosensor with higher sensitivity was constructed for dopamine determination (two orders of magnitude lower than that previously reported), showing that DNR/CuNCs have a potential for application in ECL bioanalysis as a new type of superior luminophore candidate.

Difference of genomic copy numbers alterations between hairy cell leukemia-variant and classical hairy cell leukemia: a pilot retrospective study in Chinese.

Background: Hairy cell leukemia (HCL) is a rare chronic B-cell lymphoproliferative disorder. It has two pathological subtypes: classical HCL (HCL-C) and HCL-variant (HCL-V). HCL-C and HCL-V are distinct in morphology and immunophenotype. Their differentiation is important for patient management and clinical outcome, with HCL-V responding poorly to conventional HCL treatments. Recently, whole genomic sequencing has been used to identify the difference between HCL-C and HCL-V and mutation of BRAFV600E has been proved to be a molecular hallmark of HCL-C. However, BRAF inhibitors were not effective in all HCL-C cases and HCL-V seems be lack of the high-frequency mutations. Therefore, it is necessary to compare the genomic changes between HCL-C and HCL-V by high-resolution studies, especially in Chinese population, the genomic alterations of HCL have rarely be reported. Methods: In this study, the clinical features of a total of 18 Chinese HCL patients were described. Single nucleotide polymorphism (SNP) array analysis was performed to evaluate the genomic copy number alterations (CNA) and copy neutral loss of heterozygosity (CN-LOH) on six HCL-Vs with CD25-/BRAFV600E- and four HCL-Cs with CD25+/BRAFV600E+. Results: A total of 24 CNAs including seven chromosomal gains and 17 chromosomal losses, and 22 CN-LOHs were revealed. Five of the six cases of HCL-V showed 15 CNAs including four cryptic chromosomal gains and 11 chromosomal losses. Overlapping regions involving micro-deletion of chromosome 2q13 and large chromosomal loss of 14q were showed in HCL-V. In HCL-C, a total of nine CNAs were revealed in three of the four cases including three chromosomal gains and six chromosomal losses. No overlapping area was observed among the CNVs. 15 CN-LOHs were showed in five of the six cases of HCL-V and seven CN-LOHs was demonstrated in all of the four HCL-Cs. Conclusions: Comparing to Westerners, a relatively higher proportion of HCL-V in all HCL is observed in this study. CNAs and CN-LOHs were common in both HCL-V and HCL-C but the CNAs were different in them. HCL-C was characterized with the higher ratio of large chromosomal changes but lacked of recurrent CNAs, while HCL-V was presented with the higher incidence of cryptic CNAs and recurrent CNAs involving tumor-associated genes. It is necessary to further investigate the association of the genes, such as NPHP1 and TRAF3 genes, and HCL-V in the future study.

Dynamic modelling on the confined crystallization of mono-sized cubic particles under mechanical vibration.

The dynamic crystallization of cubic granular particles under three-dimensional mechanical vibration is numerically investigated by the discrete element method. The effects of operational conditions (vibration, container shape and system size) and particle properties (gravity and friction) on the formation of crystals and defects are discussed. The results show that the formation and growth of clusters with face-to-face aligned cubic particles can be easily realized under vibrations. Especially, a single crystal with both translational and orientational ordering can be reproduced in a rectangular container under appropriate vibrations. It is also found that the gravitational effect is beneficial for the ordering of a packing; the ordering of frictional particles can be improved significantly with an enlarged gravitational acceleration. The flat walls of a rectangular container facilitate the formation of orderly layered structures. The curved walls of a cylindrical container contribute to the formation of ring-like structures, whereas they also cause distortions and defects in the packing centers. Finally, it is shown that the crystallization of inelastic particles is basically accomplished by the pursuit of a better mechanical stability of the system, with decreasing kinetic and potential energies.

Facile synthesis of graphitic C3N4 nanoporous-tube with high enhancement of visible-light photocatalytic activity.

A simple and convenient method was used to synthesize a graphitic carbon nitride (g-C3N4) nanoporous-tube by using SiO2 nanoparticles as pore formers. The structure of the g-C3N4 nanoporous-tube was characterized by the SEM and TEM images. Taking photodegradation of RhB as an example, the photocatalytic activity of the as-prepared g-C3N4 nanoporous-tube was investigated. It can photodegrade 90% RhB in 40 min under visible-light irradiation and obtain a k value of 0.04491 min-1, which is 8.16 times that of bulk g-C3N4, 3.09 times that of tubular g-C3N4 and 1.48 times that of tubular g-C3N4-SiO2. The significant enhancement in photocatalytic efficiency is due to the edge effect of the pores and the special structure of the tubes. In addition, the possible mechanism of photocatalytic degradation of RhB was also proposed based on the trapping experiment of active species, which indicated that the superoxide radicals ([Formula: see text]) and the holes (h +) were the main reactive species in this photocatalyst. This work may open up a new idea of innovation in g-C3N4 structure and inspire its follow-up study.

Effect of stimulating acupoint Guanyuan (CV 4) on lower back pain by burning moxa heat for different time lengths: a randomized controlled clinical trial.

OBJECTIVE: To investigate the effect of different heat-stimulating time lengths on lower back pain. METHODS: Forty participants were randomly assigned to four groups of various heating time lengths. The short heating time length group (SL), moderate heating time length group (ML), and long heating time length group (LL) respectively received 15, 30, and 60 min of moxibustion therapy stimulating the acupoint Guanyuan (CV 4). The conventional acupuncture group (CA) received needle acupuncture treatment as a control group. The participants were treated continuously over a 2-week treatment period for a total of 10 sessions, with five sessions given per week. Participants were assessed weekly by blinded assessors,using the visual analogue scale (VAS) and Roland Morris Questionnaire (RMQ). RESULTS: The VAS and RMQ scores reduced in all four groups during treatment. There were significant differences in VAS scores (P < 0.01) and RMQ scores (P < 0.01) between before treatment and after 2 weeks of treatment in the LL group. After treatment, the LL group reported significantly lower VAS scores compared with the CA group, ML group, and SL group (P < 0.05). CONCLUSION: The long and moderate lengths of heat-stimulating time of 30 and 60 min may be more effective for relieving lower back pain than that of short stimulating time lengths.

Immobilization of two dendritic organic phases onto silica and their molecular shape recognition for polycyclic aromatic hydrocarbons, tocopherols and carotenoid isomers.

BACKGROUND: Molecular shape selectivity, based on the size and shape parameters of the molecule, such as length and planarity, is a separation process that can be used for compounds with restricted shapes, such as isomers. The separation of geometric isomers is challenging because these compounds have similar physicochemical properties but differ slightly in molecular shape. The ability to separate and quantify these isomers is important in high performance liquid chromatography (HPLC), which is one of the most widely used techniques in separation science today, because the shape of the molecule has a strong influence on biological processes. RESULTS: We prepared symmetrical discoidal dendrimeric organomolecule gelators (GSDM) and o-phenylenediamine-derived low-molecular-weight dendrimeric organomolecule gelators (G1) and bonded them to silica surfaces. The dendritic organic compound-grafted silica (SiO2@GSDM and SiO2@G1) was used as HPLC stationary phases for the separation of shape-restricted isomers of polycyclic aromatic hydrocarbons (PAHs), carotenoids and tocopherols. The two phases exhibit a very high molecular shape selectivity compared to the commercially available alkyl phases. There are differences in molecular shape selectivity between the two stationary phases. Changes in the chemical structure of dendritic organic compounds can alter the orientation of the molecules, as well as changes in the molecular recognition ability. It was found that SiO2@GSDM has high molecular linear selectivity for PAHs at different temperatures, even at 50 °C. The planar selectivity of SiO2@GSDM was better for triphenylene and o-terphenyl benzenes compared to SiO2@G1. SIGNIFICANCE: This separation behavior may be attributed to the combined effect of weak interaction centers, which allowed the effective separation of bioactive and shape-restricted isomers through multiple interactions. Furthermore, SiO2@GSDM showed better separation of tocopherols and carotenoids, suggesting that the backbone and ordered structure of organic molecular gelators is an effective way to improve the shape selectivity of the molecules, whereas the molecular orientation of the functional groups influences the separation mechanism of the shape-restricted isomers.

Coexistence of virulent and multidrug-resistant plasmids in an uropathogenic Escherichia coli.

OBJECTIVES: The emergence of pathogens co-harbouring multiple mobile resistance and virulence elements is of great concern in clinical settings. Herein, we report an O101: H10-ST167 Escherichia coli Hu106 strain isolated from the urinary tract of a female in China. METHODS: Antibiotic susceptibility testing was used to present the antimicrobial resistance spectrum. Whole-genome sequencing (WGS) and bioinformatic analysis were used to clarify the virulent and resistance mechanisms. Furthermore, the virulence of this strain was tested by the Greater wax moth larvae and siderophore production experiment. RESULTS: The strain E. coli Hu106 was resistant to almost all antimicrobials tested, and only susceptible to aztreonam, amikacin, and tigecycline. WGS analysis revealed that the strain Hu106 co-harboured blaNDM-9 and mcr-1 on p2-Hu106, belonging to IncHI2/IncHI2A (256,000 bp). The co-existence of both resistance genes, blaNDM-9 and mcr-1, on the plasmid p2-Hu106 was mainly acquired by transposition recombination of mobile antibiotic elements mediated by IS26 and/or IS1 on IncHI2/IncHI2A type plasmid. In addition, the virulence clusters aerobactin (iutA-iucABCD) and salmochelin (iroBCDEN) were identified on an IncFIB/IncFIC(IncFII) type plasmid p1-Hu106, flanked by small mobile elements such as IS1A, ISkpn28, and IS3, respectively. After performing genomic comparison of p1-Hu106 with the WGS in NCBI, we identified that the virulent plasmid p1-Hu106-like could spread in different clones of E. coli and Klebsiella pneumoniae, revealing its underlying dissemination mechanism between Enterobacterales. Furthermore, the strain caused a decreased survival rate of larvae and produced high siderophore units (62.33%), similar to hypervirulent K. pneumoniae NTUH-K2044. CONCLUSIONS: The strains co-carrying the multidrug-resistant plasmid p2-Hu106 and virulent plasmid p1-Hu106 should be closely monitored to prevent its further spreading.

Effect of acupuncture anesthesia on acne vulgaris of pricking-bloodletting cupping: a single-blind randomized clinical trail.

OBJECTIVE: To evaluate the effect on acne vulgaris of pricking-bloodletting cupping at Dazhui (GV 14) under acupuncture anesthesia, and establish whether providing anesthesia to the treatment area by manipulating Hegu (LI 4) and Quchi (LI 11) might have an additional therapeutic benefit. METHODS: Thirty-eight patients were recruited and randomized into a control group and an intervention group with a single-blind (observer-blind) method. The control group was treated by pricking-bloodletting cupping at Dazhui (GV 14)-and the studied group by pricking-bloodletting cupping at Dazhui (GV 14) under acupuncture anesthesia at Hegu (LI 4) and Quchi (LI 11). Both groups were treated twice weekly for 6 weeks. The analgesic and therapeutic effects of acupuncture were evaluated on a visual analog scale (VAS) and global acne grading system (GAGS), respectively. RESULTS: There were differences in the VAS scores of pain on pricking and in the pricked area, and the duration of pain between the groups. After 12 treatments, there was a significant reduction in GAGS scores from baseline in both groups, but there was no significant difference between the groups. CONCLUSION: Acupuncture anesthesia at Hegu (LI 4) and Quchi (LI 11) is an effective means of alleviating the pain of pricking-bloodletting cupping and reducing the duration of pain in the treatment area. Pricking-bloodletting cupping at Dazhui (GV 14) improves the skin lesions of patients with moderate acne vulgaris, but acupuncture anesthesia does not appear to have an additional therapeutic effect.

Within-host resistance evolution of a fatal ST11 hypervirulent carbapenem-resistant Klebsiella pneumoniae.

OBJECTIVES: Hypervirulent carbapenem-resistant Klebsiella pneumoniae (hv-CRKp) has become a great threat to public health. This study reported an hv-CRKp-associated fatal infection and revealed its mechanisms of antimicrobial resistance and within-host evolution. METHODS: A carbapenem-susceptible K. pneumoniae (CSKp) and 11 KPC-producing CRKp strains were isolated from a lung transplant recipient receiving continual antimicrobial therapy for 1.5 years. Pulsed-field gel electrophoresis (PFGE) separated two clusters between CSKp and CRKp. RESULTS: Further whole genome sequencing analysis found that all 11 CRKp were ST11-KL64 clones, while the CSKp was ST412-KL57. Among these 11 CRKp strains, three and one were resistant to colistin and ceftazidime/avibactam (CAZ/AVI), respectively. Three different mechanisms were found to be responsible for the colistin resistance, including the insertions of two different IS (ISKpn74 and IS903B) into the same position of mgrB and one related to the efflux pump system. CAZ/AVI resistance was associated with blaKPC-2 mutation, and it was also found that increasing blaKPC-2 expression increased the MICs of CAZ/AVI, but not at the resistance level. All these 12 strains had iucABCDiutA virulence cluster and rmpA/rmpA2 genes, with higher siderophore production than a reference classic K. pneumoniae (cKp), which were thought to be hypervirulent K. pneumoniae (hvKp). However, only the CSKp showed higher mucoviscosity according to the mucoviscosity assay. Genomic analysis showed that the rmpA variation (interrupted by ISKpn26) existed in all CRKp strains except the CSKp strain, demonstrating that hypermucoviscous phenotype assays could not accurately identify hvKp. CONCLUSION: This study depicted a rapid and diverse within-host evolution of resistance in hv-CRKp of ST11-KL64 clone.

A phase II study of chidamide, cytarabine, aclarubicin, granulocyte colony-stimulating factor, and donor lymphocyte infusion for relapsed acute myeloid leukemia and myelodysplastic syndrome after allogeneic hematopoietic stem cell transplantation.

Chemotherapy followed by donor lymphocyte infusion (DLI) is a promising treatment for relapsed acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) after allogeneic hematopoietic stem cell transplantation (allo-HSCT). However, the best strategy for administering this therapy is still unclear. This study sought to explore the efficacy and safety of chidamide and CAG (cytarabine, aclarubicin, and granulocyte colony-stimulating factor) (CCAG) regimen followed by DLI in relapsed AML/MDS after allo-HSCT. This was a single-arm, phase II trial in patients with relapsed AML/MDS after allo-HSCT. CCAG regimen followed by DLI was given according to the inclusion and exclusion criteria. Twenty adult patients were enrolled. The median follow-up time was 12 months. The complete remission (CR) rate was 45% and the partial remission (PR) rate was 5%. The 1-year overall survival (OS) was 56.7% (95% confidence interval (95% CI), 31.6-75.6%), and the median OS was 19 months. The 1-year relapse-free survival (RFS) was 83.3% (95% CI, 27.3-97.5%). Patients relapsing more than 6 months after HSCT and achieving CR/PR after CCAG plus DLI regimen attained significantly higher survival rates. The cumulative incidence of grade III-IV acute graft-versus-host disease (aGVHD) was 9.4%. There was no treatment-related mortality (TRM). These data suggest that CCAG plus DLI regimen is safe and induces durable remission and superior survival in patients with relapsed AML/MDS after allo-HSCT. Trial registration number: ChiCTR.org identifier: ChiCTR1800017740 and date of registration: August 12, 2018.

Evaluation of BACTEC MGIT 960 system for recovery of Nocardia from clinical specimens.

Nocardia spp. is an aerobic Gram-positive bacillus responsible for nocardiosis. Herein, we performed a retrospective study to evaluate the performance of BACTEC MGIT 960 system, in comparison with smear microscopy and blood agar plate (BAP) culture, to recover Nocardia from different clinical specimens. Furthermore, the inhibitory effect of antibiotics contained in MGIT 960 tube on Nocardia was also evaluated. The sensitivities for Nocardia recovery using smear microscopy, BAP culture, and MGIT 960 were 39.4% (54/137), 46.1% (99/215), and 81.3% (156/192), respectively. N. farcinica was the most detected species (60.4%, 136/225). In MGIT 960-recovered Nocardia strains, N. farcinica accounted for 76.9%. Furthermore, trimethoprim in MGIT 960 tube inhibited less N. farcinica growth than that of other Nocardia species, partially explaining why MGIT 960 recovered more N. farcinica from sputa. The current study demonstrated that MGIT 960 could recover Nocardia strains from heavily-contaminated samples if its components and antibiotics are redesigned.

Survival analysis of transplant-associated thrombotic microangiopathy under different diagnostic criteria and the efficacy of plasma exchange.

BACKGROUND Transplant-associated thrombotic microangiopathy (TA-TMA) is a serious complication of hematopoietic stem cell transplantation (HSCT). The efficacy and survival of plasma exchange (PE) for TA-TM have not been fully clarified. In addition, there is a lack of consensus on diagnostic criteria for TA-TMA.  MATERIAL AND METHODS We retrospectively analyzed 32 patients diagnosed with TA-TMA by different diagnostic criteria from January 2018 to February 2022 at the First Medical Center of the PLA General Hospital. RESULTS (1) The patients with TA-TMA treated with PE in this study had a remission rate of 42.8%, a 100-day OS of 47.6%, and a 6-month OS of 38.1%. The only factor affecting the response to PE treatment was the number of PE sessions (P = 0.047). (2) III-IV aGVHD prior to TA-TMA diagnosis (P = 0.002), renal or neurological dysfunction (P = 0.021), and the time to onset of TA-TMA (P = 0.002) were independent risk factors for overall survival with TA- TMA. (3) Probable TA-TMA had the highest survival rate, but the Jodele criteria are expected to diagnose earlier and provide the greatest benefit to patients. CONCLUSIONS PE is an effective treatment for TA-TMA especially in cases where complement blockers are not available. In addition, probable TA-TMA improved prognostic survival through early detection of patients with TA-TMA. There is a need for further large prospective trials to identify the population more suitable for PE treatment of TA-TMA and more valid diagnostic criteria.

Within-host acquisition of colistin-resistance of an NDM-producing Klebsiella quasipneumoniae subsp. similipneumoniae strain through the insertion sequence-903B-mediated inactivation of mgrB gene in a lung transplant child in China.

Background: Colistin, as the antibiotic of "last resort" for carbapenem-resistant Klebsiella, develop resistance during administration of this antimicrobial agent. We identified an NDM-1-producing Klebsiella quasipneumonuae subsp. similipneumoniae (KQSS) strain KQ20605 recovered from a child, which developed resistance to colistin (KQ20786) through acquiring an IS903B element between the -27th and -26th bp of mgrB promoter region after 6-day colistin usage. Objectives: The aim of this study is to explore the source of IS903B in the disruptive mgrB gene and its underlying mechanisms. Materials and methods: Antibiotics susceptibility testing was conducted via microbroth dilution method. The in vitro colistin-induced experiment of KQ20605 was performed to mimic the in vivo transition from colistin-sensitive to resistant. Whole-genome sequencing was used to molecular identification of colistin resistance mechanism. Results: The IS903B element integrated into mgrB gene of KQ20786 had a 100% nucleotide identity and coverage match with one IS903B on plasmid IncR, and only 95.1% (1005/1057) identity to those on chromosome. In vitro, upon the pressure of colistin, KQ20605 could also switch its phenotype from colistin-sensitive to resistant with IS elements (e.g., IS903B and IS26) frequently inserted into mgrB gene at "hotspots", with the insertion site of IS903B nearly identical to that of KQ20786. Furthermore, IS26 elements in this isolate were only encoded by plasmids, including IncR and conjugative plasmid IncN harboring bla NDM. Conclusion: Mobilizable IS elements on plasmids tend to be activated and integrated into mgrB gene at "hotspots" in this KQSS, thereby causing the colistin resistance emergence and further dissemination.

Genetic Diversity of Polymyxin-Resistance Mechanisms in Clinical Isolates of Carbapenem-Resistant Klebsiella pneumoniae: a Multicenter Study in China.

Polymyxin has been the last resort to treat multidrug-resistant Klebsiella pneumonia. However, recent studies have revealed that polymyxin-resistant carbapenem-resistant Klebsiella pneumonia (PR-CRKP) emerged due to the mutations in chromosomal genes or the plasmid-harboring mcr gene, leading to lipopolysaccharide modification or efflux of polymyxin through pumps. Further surveillance was required. In the present study we collected PR-CRKP strains from 8 hospitals in 6 provinces/cities across China to identify the carbapenemase and polymyxin resistance genes and epidemiological features by whole-genome sequencing (WGS). The broth microdilution method (BMD) was performed to determine the MIC of polymyxin. Of 662 nonduplicate CRKP strains, 15.26% (101/662) were defined as PR-CRKP; 10 (9.90%) were confirmed as Klebsiella quasipneumoniae by WGS. The strains were further classified into 21 individual sequence types (STs) by using multilocus sequence typing (MLST), with ST11 being prevalent (68/101, 67.33%). Five carbapenemase types were identified among 92 CR-PRKP, blaKPC-2 (66.67%), blaNDM-1 (16.83%), blaNDM-5 (0.99%), blaIMP-4 (4.95%), and blaIMP-38 (0.99%). Notably, 2 PR-CRKP strains harbored both blaKPC-2 and blaNDM-1. The inactivation of mgrB, associated significantly with high-level polymyxin resistance, was mainly caused by the insertion sequence (IS) insertion (62.96%, 17/27). Furthermore, acrR was inserted coincidently by ISkpn26 (67/101, 66.33%). The deletion or splicing mutations of crrCAB were significantly associated with ST11 and KL47 (capsule locus types), and diverse mutations of the ramR gene were identified. Only one strain carried the mcr gene. In summary, the high IS-inserted mgrB inactivation, the close relationship between ST11 and the deletion or splicing mutations of the crrCAB, and the specific features of PR-K. quasipneumoniae constituted notable features of our PR-CRKP strains in China. IMPORTANCE Polymyxin-resistant CRKP is a serious public health threat whose resistance mechanisms should be under continuous surveillance. Here, we collected 662 nonduplicate CRKP strains across China to identify the carbapenemase and polymyxin resistance genes and epidemiological features. Polymyxin resistance mechanism in 101 PR-CRKP strains in China were also investigated, 9.8% of which (10/101) were K. quasipneumoniae, as determined via WGS, and inactivation of mgrB remained the most crucial polymyxin resistance mechanism, significantly related to high-level resistance. Deletion or splicing mutations of crrCAB were significantly associated with ST11 and KL47. Diverse mutations of the ramR gene were identified. The plasmid complementation experiment and mRNA expression analysis further confirmed that the mgrB promoter and ramR played a critical role in polymyxin resistance. This multicenter study contributed to the understanding of antibiotic resistance forms in China.