Epidemic Characteristics of Carbapenem-Resistant Klebsiella pneumoniae in the Pediatric Intensive Care Unit of Yanbian University Hospital, China.

INTRODUCTION: Carbapenem-resistant Enterobacteriaceae (CRE) pose a serious threat to clinical patient management and public health, as they are generally resistant to most antibiotics and cause infections with high mortality rates. Klebsiella pneumoniae ranks second among Enterobacteriaceae species that cause nosocomial infections. In this study, we investigated the epidemic characteristics of carbapenem-resistant K. pneumoniae (CRKP) in the pediatric intensive care unit (PICU) of Yanbian University Hospital. MATERIALS AND METHODS: A total of 14 non-duplicate CRKP strains, collected from March 2015 to November 2019, were subjected to automated microbial identification and antimicrobial susceptibility tests using the Phoenix-100 ID/AST system. The strains were also subjected to genotypic resistance testing, polymerase chain reaction assays to detect genes encoding carbapenemases and other ß-lactamases, multi-locus sequence typing (MLST), and pulsed-field gel electrophoresis (PFGE)-based homology analysis. RESULTS: Two carbapenemase genes, KPC-2 and NDM-1 (in eight and six strains, respectively), were detected. MLST enabled the division of the strains into two sequence types, ST11 and ST1224 (containing eight and six strains, respectively). PFGE results classified the 14 strains into clonotypes A-D, of which clonotypes A and B belonged to ST11, while clonotypes C and D belonged to ST1224. CONCLUSION: Our study reveals that epidemics of the KPC-2-ST11 and NDM-1-ST1224 strains occurred in the PICU of Yanbian University Hospital. Surveillance and strict implementation of prevention and control measures are crucial to prevent the occurrence and rapid spread of nosocomial infections.

Molecular Characteristics of Carbapenem-Resistant Enterobacter cloacae in a Tertiary Hospital in China.

BACKGROUND: Infections caused by the carbapenem-resistant Enterobacter cloacae (CREC) bring great challenges to the clinical treatment and pose a serious threat to public health. In this study, we investigated the molecular characteristics of CREC in a tertiary hospital. MATERIALS AND METHODS: A total of 12 non-duplicate CREC strains isolated during the period of November 2016 to July 2019 were subjected to automated microbial identification and antimicrobial susceptibility testing (AST) using the BD Phoenix-100 identification and antimicrobial susceptibility testing (ID/AST) system. The strains were also subjected to phenotypic screening for the detection of antibiotic resistance genes such as the carbapenemase and other ß-lactamase genes, with the use of the polymerase chain reaction assay (PCR). Finally, multi-locus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE)-based homology analysis were applied. RESULTS: Four types of carbapenemases namely IMP-26, NDM-5, NDM-1, and KPC-2 were identified in 12 CREC strains. IMP-26 was the most prevalent type (6/12 strains, 50 %), followed by NDM-5 (3/12 strains, 25 %). The results of MLST revealed that these 12 strains could be divided into five sequence types (STs) among which ST544 was the dominant type (6/12 strains, 50 %). The PFGE results divided the 12 strains into four clusters. CONCLUSION: Our study indicated that the epidemics of the IMP-26-producing E. cloacae ST544 strain did occur in the intensive care unit (ICU) of a tertiary hospital. Therefore, early surveillance and strict implementation of control measures are crucial for the prevention of nosocomial infections and transmissions in hospitals.

Anti-tumor outcome evaluation against non-small cell lung cancer in vitro and in vivo using PolyI:C as nucleic acid therapeutic agent.

PolyI:C as a ligand of toll-like receptor 3 has been explored as a nucleic acid therapeutic agent for anti-tumor therapy. The previous PolyI:C studies mainly focused on anti-tumor evaluation at cell level and anti-tumor mechanism involved in MyD88-independent pathway. However, there is a lack of information about the ability of PolyI:C to affect PI3K/Akt/p53 signaling pathway in non-small cell lung cancer (NSCLC), and its pharmacodynamic evaluation in vivo still remain unclear so far. In this study, we explored the anti-tumor mechanism and efficacy in vivo of PolyI:C in NSCLC. Our results showed that PolyI:C had the ability to inhibit tumor cell proliferation and promote cell apoptosis by inducing G1 cell cycle block in LL/2 and A549 NSCLC cells. In vivo animal studies also demonstrated that PolyI:C effectively inhibited the tumor growth, suppressed spontaneous metastasis and prolonged the survival time of LL/2 tumor-bearing mice. Moreover, western blotting and immunohistochemistry assays showed that its anti-tumor mechanism was associated with the interference with PI3K/Akt/p53 signaling pathway. Our results confirmed that PolyI:C increased the expression of CD80, CD86 in spleen dendritic cells of tumor-bearing mice and cytokine secretion in healthy mice. Generally, our study suggests that PolyI:C can become a promising anti-tumor agent.

The AIB1siRNA-loaded hyaluronic acid-assembled PEI/heparin/Ca2+ nanocomplex as a novel therapeutic strategy in lung cancer treatment.

In the present study, AIB1siRNA­loaded polyethyleneimine (PEI)/heparin/Ca2+ nanoparticles (NPs) were successfully prepared and evaluated for their efficacy in lung cancer cells. The results demonstrated that the PEI and heparin complex reduced the toxic effect in cancer cells while maintaining its transfection efficiency. A nanosized particle of ~25 nm was formulated and siRNA was demonstrated to possess excellent binding efficiency in the particles. Confocal microscopy revealed that fluorescein­labeled (FAM)­small interfering (si)RNA dissociated from the HA­PEI/heparin/Ca2+/siRNA (CPH­siH) NPs and exhibited maximum fluorescence in the cytoplasm, which was important in elucidating its post­transcriptional activity. CPH­siH NPs exhibited a typical concentration­dependent toxicity in cancer cells. Blank PEI/heparin/Ca2+ did not induce any toxicity in cancer cells, indicating its safety and lack of side effects. CPH­siH (100 nm) induced the maximum apoptosis of cancer cells with nearly ~35% of cells in the early and late apoptosis stages. The expression of the nuclear receptor coactivator 3 (NCOA3, also known as AIB1) protein was knocked down in a concentration­dependent manner, demonstrating the potent activity of AIB1siRNA in cancer cells. Together, these results indicated that HA­PEI/heparin/Ca2+ NPs may be a promising carrier for the anticancer activity of AIB1siRNA in lung cancer cells.

A Randomized Multicenter Phase III Study of Single Administration of Mecapegfilgrastim (HHPG-19K), a Pegfilgrastim Biosimilar, for Prophylaxis of Chemotherapy-Induced Neutropenia in Patients With Advanced Non-Small-Cell Lung Cancer (NSCLC).

BACKGROUND: Mecapegfilgrastim (code name HHPG-19K) is a biosimilar to pegylated recombinant human granulocyte-colony stimulating factor (PEG-rhG-CSF). The efficacy and safety of mecapegfilgrastim, using a regimen of once-per-cycle injection of 100-µg/kg or a fixed 6-mg dose, were evaluated for the prophylactic therapy for neutropenia in patients with advanced non-small-cell lung cancer (NSCLC) who were treated with myelosuppressive chemotherapy. MATERIALS AND METHODS: Patients were randomized (1:1:1) blindly to 3 treatment arms to receive a single injection of mecapegfilgrastim 100 µg/kg, a 6-mg fixed dose of mecapegfilgrastim, or saline (control) in cycle 1. In cycles 2 to 4 following unblinding at the end of cycle 1, patients in the control arm received daily injections of short-acting rhG-CSF at a dose of 5 µg/kg, whereas patients in the 2 mecapegfilgrastim arms continued the same treatment as in cycle 1. All patients received 4 chemotherapy cycles of docetaxel combined with cisplatin or carboplatin every 21 days. The primary endpoint was the incidence of grade ≥ 3 neutropenia in cycle 1. RESULTS: A single dose of 100 µg/kg or a fixed 6-mg dose of mecapegfilgrastim per cycle effectively reduced chemotherapy-induced neutropenia and was comparable to daily rhG-CSF with regard to all efficacy endpoints, including incidence of grade ≥ 3 neutropenia, incidence of febrile neutropenia, duration of grade ≥ 3 neutropenia, and time to neutrophil recovery. No difference in efficacy parameters was observed between the 2-dose regimens of mecapegfilgrastim across all cycles. Mecapegfilgrastim was well-tolerated and was as safe as daily rhG-CSF. CONCLUSION: Once-per-cycle injection of mecapegfilgrastim is as effective and safe as daily rhG-CSF for prophylaxis of chemotherapy-induced neutropenia in patients with NSCLC. Mecapegfilgrastim (fixed 6-mg dose) is recommended in clinical practice for its convenient dose management.

Synthesis and Antibacterial Evaluation of (S,Z)-4-methyl-2-(4-oxo-5-((5-substituted phenylfuran-2-yl) methylene)-2-thioxothiazolidin-3-yl)Pentanoic Acids.

The microbial resistance has become a global hazard with the irrational use of antibiotics. Infection of drug-resistant bacteria seriously threatens human health. Currently, there is an urgent need for the development of novel antimicrobial agents with new mechanisms and lower levels of toxicity. In this paper, a series of (S ,Z)-4-methyl-2-(4-oxo-5-((5-substitutedphenylfuran-2-yl) methylene)-2-thioxothiazolidin-3-yl)pentanoic acids via a Knoevenagel condensation were synthesized and evaluated for their antibacterial activity in - vitro. The synthesized compounds were characterized by IR, (1)H NMR and MS. The antibacterial test in - vitro showed that all of the synthesized compounds had good antibacterial activity against several Gram-positive bacteria (including multidrug-resistant clinical isolates) with minimum inhibitory concentration (MIC) values in the range of 2-4 µg/mL. Especially compounds 4c, 4d, 4e and 4f were the most potent, with MIC values of 2 µg/mL against four multidrug-resistant Gram-positive bacterial strains.

Apolipoprotein C3 genetic polymorphisms are associated with lipids and coronary artery disease in a Chinese population.

BACKGROUND: The disorder of triglyceride (TG) metabolism leading to hypertriglyceridemia is an independent risk factor for coronary artery disease (CAD). Variants in the apolipoprotein C3 (APOC3) gene were found to be associated with elevated TG levels. The purpose of this study was to investigate the effect of two polymorphisms (1100 C/T and 3238 C/G) of APOC3 on plasma lipid and risk of CAD in a Chinese population. METHODS: The study population consisted of 600 patients with CAD and 600 age- and gender-matched controls. The APOC3 gene polymorphism was analyzed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). RESULTS: Patients with CAD had a significantly higher frequency of APOC3 3238 GG genotype [odds ratio (OR) =1.64, 95% confidence interval (CI) =1.10, 2.43; P = 0.01] and APOC3 3238 G allele (OR =1.27, 95% CI =1.04, 1.55; P = 0.02) than controls. The findings are still emphatic by the Bonferroni correction. When stratifying by hyperlipidemia, CAD patients with hyperlipidemia had a significantly higher frequency of APOC3 3238 GG genotype (OR =1.73, 95% CI =1.13, 2.64; P = 0.01) than without hyperlipidemia. The APOC3 3238 G allele was significantly associated with increasing plasma TG levels and very-low-density lipoprotein cholesterol (VLDL-C) levels both in cases and controls (P < 0.001). CONCLUSIONS: The APOC3 3238 G allele might contribute to an increased risk of CAD as a result of its effect on TG and VLDL-C metabolism.

[c-Met signaling pathway participating in the gefitinib resistance of different gene types of non-small cell lung cancer cells induced by HGF in vitro].

BACKGROUND AND OBJECTIVE: It has been known that hepatocyte growth factor (HGF) induces gefitinib resistance in non-small cell lung cancer (NSCLC) cells. The possible mechanism may be related to the activation of the HGF receptor c-Met. The aim of this study is to investigate the involvement of c-Met and its downstream signaling pathway in the HGF-induced gefitinib resistance of NSCLC cells with different epidermal growth factor receptor (EGFR) gene types. METHODS: NSCLC cell lines with different EGFR genes (PC-9, PC9/R, H292, and A549) were selected and induced by HGF. Cell survival was determined by MTT assay and the expression of Met and downstream signaling proteins were examined by Western blot. RESULTS: Gefitinib inhibited the cell growth of PC9, H292, and A549 cell lines in a dose-dependent manner. The concentration-survival curve notably shifted to the right when induced by HGF. The apoptotic rate was lower when the cells were treated with HGF and gefitinib than when these cells were treated with gefitinib alone (P<0.05), particularly in PC9, H292, and A549 cells, but not in PC9/R. HGF stimulated the phosphorylation of Met and downstream signaling proteins in PC9, H292, PC9/R, and A549 cell lines. p-Met, p-Akt, p-Stat3, and p-Erk1/2 expressions were higher when the cells were treated with HGF and gefitinib than when these cells were treated with gefitinib alone, particularly in PC9, H292, and A549 cells, but not in PC9/R. CONCLUSIONS: c-Met and its downstream signaling pathway possibly participated in the HGF-induced gefitinib resistance in NSCLC cells with different EGFR gene types.

[The mechanism of gefitinib resistance induced by hepatocyte growth factor in sensitive non-small cell lung cancer cells in vitro].

BACKGROUND: Previous studies have reported that Met might be related to gefitinib resistance in non-small cell lung cancer (NSCLC). The present study aims to explore the mechanism of hepatocyte growth factor (HGF)-induced gefitinib resistance in different gene types of sensitive NSCLC in vitro. METHODS: The PC-9 and H292 cell lines were chosen and induced by HGF. The cell survival was measured using MTT assay, the cell cycle distribution was measured using PI assay, and cell apoptosis with an Annexin V-PE assay, respectively. The c-Met and p-Met protein expression was determined via Western blot analysis. RESULTS: Gefitinib inhibited the growth of PC-9 and H292 cells in a dose-dependent manner. The concentration-survival curves of both cell lines shifted to the right when induced with HGF. HGF did not affect PC-9 and H292 cell proliferation. The cell also had a higher cell survival rate when treated with HGF and gefitinib compared with that under gefitinib alone (P<0.05). The apoptotic rate and cell cycle progression showed no significant difference between the HG and G group (P>0.05). HGF stimulated Met phosphorylation in the PC-9 and H292 cells. Gefitinib inhibited the HGF-induced Met phosphorylation in PC-9 cells, but not in H292 cells. CONCLUSIONS: HGF induces gefitinib resistance in PC-9 and H292 cells. HGF-induced Met phosphorylation may be an important mechanism of gefitinib resistance in sensitive NSCLC.

[Influence of Radix Astragali on nitric oxide and endothelin-1 in pulmonary tissue in hypoxemic pulmonary hypertension in rats].

OBJECTIVE: To study the influence of Radix Astragali (RA) on pulmonary tissue endothelin-1 (ET-1) and nitric oxide (NO) in hypoxic pulmonary hypertension rats. METHODS: Twenty one healthy male Wistar rats weighing 210-310 g were divided into three group at random with 7 in each. The rats in control group were raised in ordinary room condition; those in hypoxic group were raised in ordinary pressure hypoxic box [concentration of O(2) was (10.0 +/- 0.5)%] for 8 hours a day, for 30 days; those in RA group were raised in the same condition as hypoxic group and treated with an intraperitoneal injection of RA 8 g/kg per day. The rats in the control group and hypoxic group were given the same volume of intraperitoneal injection of normal saline. Mean pulmonary arterial pressure (mPAP), mean carotid artery pressure (mCAP) were measured via right cardiac catheterization, concentration of NO in pulmonary tissue was measured by radioimmunoassay. RESULTS: (1) The mPAP (mm Hg) (21.9 +/- 1.6) and ET-1 (pg/ml) (309.1 +/- 58.1) in hypoxemic group were significantly higher than those in RA group (16.2 +/- 0.8, 287.7 +/- 57.5) and control group (15.3 +/- 0.8, 241.1 +/- 52.5) (P < 0.01, < 0.05), but the difference between RA group and control group was not significant. (2) NO (micromol/L) in pulmonary tissue in hypoxemic group (6.5 +/- 0.3) was lower than that in RA group and control group (9.2 +/- 0.9), NO in RA group was higher than that in hypoxic group but lower than that in control group (P < 0.05). (3) There was no significant difference in mCAP among the three groups (P > 0.05). (4) Under electron microscope, the endothelial cells of arterioles of the lung tissue of control group were flat and had normal morphology. However, in the lung tissue of hypoxic group, there were proliferation, hypertrophy and swelling of endothelial cells of pulmonary medium and small arteries and plenty of mitochondria and endoplasmic reticula in cytoplasm. CONCLUSION: Chronic hypoxia can result in reconstruction and endothelial lesion in pulmonary arterioles of rats, elevation of mPAP and ET-1 in pulmonary tissue, and decrease of NO. Injection of Radix Astraglai can reverse the reconstruction of pulmonary vessels partially, regulate the concentration of ET-1 and NO in pulmonary tissue, which may have certain therapeutic effects on pulmonary arteriolar changes induced by hypoxia.