Advances in the Treatment of Carbapenem-Resistant Enterobacteriaceae Infection / 医药导报

With the continuous development of medical science and the widespread use of antibiotics,the problem of bacterial resistance is increasing,especially the increasing carbapenem-resistant Enterobacteriaceae(CRE)infection,and the high mortality rate,which brings great challenges to clinical treatment.In this paper,the mechanism of drug resistance,existing antibac-terial drugs,and exploratory treatment options for CRE are reviewed,and the research progress in treating CRE infection is dis-cussed to provide more reliable evidence and a theoretical basis for clinical practice.

Construction of hepatocyte-specific Sirt3 gene knockout mouse model / 安徽医科大学学报

Objective @#To construct hepatocyte-specific silence information regulator 3 ( Sirt3 ) gene knockout (Sirt3Δhep ) mice by Cre-loxP technique , and to provide an important animal model for further studying the biological function of the hepatocyte Sirt3 gene in diseases . @*Methods @#LoxP-labeled Sirt3flox/flox mice were mated with Alb-Cre homozygous (Alb-Cre + / + ) mice , and the F1 generation Sirt3flox/ - /Alb-Cre + / - mice were then mated with Sirt3flox/flox mice , and the F2 genotype of Sirt3flox/flox/Alb-Cre + / - mice were the Sirt3Δhep mice constructed in this ex- periment. Sirt3flox/flox/Alb-Cre - / - (Sirt3flox/flox ) mice were the control mice . Mouse tail genome DNA was extracted and PCR was used to identify the genotypes of the offspring mice . Immunofluorescence was used to detect Sirt3 ex- pression in mouse hepatocytes . Primary hepatocytes and tissue proteins of Sirt3Δhep mice were extracted , and the ex- pression of Sirt3 in mouse hepatocytes and other tissues was verified by Western blot. HE staining was used to ob- serve mice ′s liver , heart , spleen , and lung tissue structure . @*Results @#Sirt3Δhep mice were successfully identified .Immunofluorescence and Western blot results demonstrated a significant decrease in the expression of Sirt3 in the hepatocytes of these mice compared to the control group ( P < 0. 01) . At the same time , there was no significant difference in the expression of Sirt3 in the heart , spleen , kidney , and lung tissues of Sirt3Δhep mice compared with the control group (P > 0. 05) . The results of HE staining showed that the histological characteristics of the liver , heart , spleen , lungs , kidneys , and other major organs of Sirt3Δhep mice were not significantly different from those of the control group mice . @*Conclusion @#Hepatocyte-specific Sirt3 gene knockout mice are successfully constructed , which provides an animal model to explore further the role and molecular mechanism of the hepatocyte Sirt3 gene in diseases .

Construction and gene identification of myeloid specific Spi1 knockout mice / 安徽医科大学学报

Objective @#To construct myeloid specific Spi1 gene knockout mice and analyze their genotypes , so as to provide animal model basis for the study of pathological mechanism of diseases and drug targets .@*Methods @#According to the principle of CRISPR/Cas9 technology and C re/LoxP system , sgRNA and Donor vectors were de signed and constructed . The transcript of Exon 2 ( Exon 2) was used as the knockout region , and Loxp elements were placed on both sides of Exon 2 . Cas9 protein , sgRNA and Donor vector were mixed and microinj ected into the fertilized eggs of C57BL/6J mice , the fertilized eggs were transplanted into the uterus of C57BL/6J pregnant female mice , and F0 generation was obtained after 19 ~ 20 days . Positive F0 mice were mated with C57BL/6J mice to ob tain stable F1 Spi1 flox/ + mice . Spi1 flox/ + mice of F1 generation were selfed to obtain Spi1 flox/flox mice . Spi1 flox/flox mated with Lyz2-Cre + mice to obtain Spi1 flox/ + /Lyz2-Cre + mice , and then mated with Spi1 flox/flox , the Spi1 flox/flox/Lyz2-Cre + mice were myeloid specific Spi1 gene knockout ( KO) mice . Spi1 flox/flox/Lyz2-cre - mice were used as wild type (WT) mice . DNA of WT and KO mice was extracted , and the genotypes were identified by agarose gel electro phoresis after PCR amplification . Western blot was used to detect the expression of spleen focus forming virus proviral integration oncogene , Spi - 1 /purine rich box - 1(PU . 1) in immune cells of WT and KO mice .@*Results@#The results of PCR identification showed that the genotype of mice with only 220 bp amplified by flox primer was Spi1 flox/flox homozygote , and the genotype of mice with 700 bp amplified by Lyz2-Cre primer was Lyz2-Cre + . Western blot showed that compared with WT group , the protein PU . 1 was not expressed in bone marrow derived macropha ges (BMDMs ) and peritoneal macrophages (PM) in KO group (P < 0.01) . There was no significant difference of statistics in the expression level of PU . 1 in T cells between KO mice and WT mice . The results of PCR and West ern blot showed that myeloid specific Spi1 KO mice were successfully constructed . @*Conclusion @#The myeloid spe cific Spi1 gene KO mice are successfully constructed and identified , which provides animal model basis for further revealing the potential mechanism of PU . 1 inimmune regulation .

Breeding and genotyping of T lymphocyte-conditional Spi1 knockout mice / 安徽医科大学学报

Objective @#To breed and identify the T lymphocyte-conditional Spi1 knockout mice for the further in- vestgation of the specific role of Spi1-encoded protein PU. 1 . @*Methods @#The Lck-Cre mice were mated with Spi1 flox/flox mice to obtain Lck-Cre ×Spi1 flox/flox mice (T lymphocyte-specific Spi1 knockout mice) , and the genotype was determined by polymerase chain reaction (PCR) and agarose gel electrophoresis . Magnetic beads were used to sort out the splenic T lymphocytes , and the knockdown efficiency of PU. 1 in T cells was detected by Western blot , quantitative real-time PCR ( qPCR) and flow cytometry. @*Results @#The Lck-Cre ×Spi1 flox/flox mouse genotype was stably inherited . Compared with Spi1 flox/flox mice , the expression level of PU. 1 was significantly reduced in splenic T cells of Lck-Cre ×Spi1 flox/flox mice . @*Conclusion @#In this study , the T lymphocyte-specific Spi1 knockout mice was successfully constructed by applying Cre/LoxP system and CRISPR/Cas9 technology , which provided a reliable an- imal model for the subsequent experiments of the specific role of PU. 1 in T cell-related diseases .

Establishment and genotype identification of hepatic stellate cell-specific Grk2 gene knockout mouse model / 中国药理学通报

Aim To establish a stable hepatic stellate cell ( HSC ) -specific G protein-coupled receptor kinase 2 ( GRK2 ) knockout mice and provide the important animal model for further studying the biological function of GRK2 in HSC. Methods The loxP-labeled Grk2 gene mouse (Grk2

Risk factors for healthcare-associated bloodstream infection of carbape-nem-resistant Enterobacterales / 中国感染控制杂志

Objective To analyze the characteristics and influencing factors of healthcare-associated bloodstream infection(HA-BSI)of carbapenem-resistant Enterobacterales(CRE).Methods Retrospective nested case-control study was adopted.Fifty-six patients with CRE HA-BSI in a tertiary general hospital from January 2020 to Decem-ber 2022 were selected as the CRE group.With a 1:1 ratio,56 patients with carbapenem-sensitive Enterobacterales(CSE)BSI during the same period was selected as the CSE group.Distribution of infection strains and departments was analyzed,and the relevant factors for CRE BSI were analyzed by univariate and multivariate logistic regression analyses.Results The distribution of CRE BSI was mainly in intensive care unit(ICU,n=23,41.07％)and de-partment of hematology(n=17,30.36％).The main infection strains were Klebsiella pneumoniae(n=32,57.14％)and Escherichia coli(n=16,28.57％).Univariate analysis showed that malignant tumor,hospitalization history within 60 days,stay in ICU for＞48 hours before infection,mechanical ventilation,indwelling central venous cathe-ter,combined use of at least two kinds of antimicrobial agents,and duration of antimicrobial use ≥10 days were all related to CRE BSI(all P＜0.05).Multivariate logistic regression analysis found that stay in ICU＞48 hours before infection and duration of antimicrobial use ≥10 days before infection were independent risk factors for CRE HA-BSI(P＜0.05).Conclusion Clinical departments,especially ICU,should pay attention to the epidemiological history of patients,identify patients with high-risk factors for CRE BSI as early as possible,use antimicrobial agents ratio-nally and standardize invasive procedure,so as to reduce the occurrence of CRE HA-BSI.

Construction of the Pkd1 gene knockout mouse model with polycystic kidney disease based on CRISPR/Cas9 technology / 中华肾脏病杂志

Objective:To establish a conditional knockout mouse model of polycystic kidney disease 1 ( Pkd1) gene based on CRISPR/Cas9 and Cre-loxP gene editing technology, and to provide an animal model for in-depth research on the role of Pkd1 gene in the development of polycystic kidney disease. Methods:In-Fusion technology was used to construct a targeting vector. Corresponding gRNAs, Cas9 mRNAs, and donor vectors carrying the loxP site were prepared based on the Pkd1 gene, and injected into the fertilized eggs of C57BL/6N mice. The fertilized eggs were transferred to the fallopian tubes of female mice with pseudopregnancy. After the newborn mice were identified by PCR and sequencing analysis, Pkd1 flox/flox F0 generation positive mice were selected. The F0 generation positive mice were bred with wild-type mice, and F1 generation heterozygous mice with Pkd1 flox/+ genotype were selected for offspring. F2 generation homozygous mice with Pkd1 flox/flox genotype were obtained through internal expansion, and then hybridized with Cre positive Ggt1/ Cre mice. F3 generation mice with Pkd1 flox/+Ggt1 Cre genotype were obtained. F4 generation mice with Pkd1 flox/flox Ggt1 Cre genotype were obtained by self crossing or backcrossing with F2 generation Pkd1 flox/flox, namely kidney-specific Pkd1 gene knockout mice ( Ggt1-cKO mice). PCR method was used to identify the genotype of mice, and then the mice were divided into wild-type control (WT) group ( n=6), Pkd1 homozygous control (PKD) group ( n=6), and Ggt1-cKO knockout validation (CKO) group ( n=6) according to the gene identification results. Real-time fluorescence quantitative PCR (RT-qPCR) was used to detect the expression of Pkd1 mRNA in the kidneys and other organs of mice in each group. HE staining was used to detect the pathological changes in renal tissues of mice in each group. The automatic biochemical detector was used to detect the blood urea nitrogen and serum creatinine levels of mice, and the kidney coefficient was calculated. Results:The PCR detection results showed that the genotype of offspring mice in CKO group was consistent with Pkd1floxflox Ggt1 Cre. Pkd1 gene was only specifically expressed in the kidney, but not in other tissues. The RT-qPCR results showed that the relative expression of Pkd1 mRNA in the renal medulla of CKO group was significantly lower than that of WT and PKD groups. The kidney volume of the CKO group had increased by about twice compared to the WT group. Under the microscope, it could be observed that there were multiple vacuoles of varying sizes and shapes in the kidneys of the CKO group, and there was a significant increase in the interstitial space of the medullary tissue. The kidney coefficient, blood urea nitrogen, and serum creatinine in the CKO group were significantly higher than those in the WT and PKD groups (all P<0.05). Conclusion:Based on CRISPR/Cas9 and Cre-loxP gene editing technology, Pkd1 gene kidney conditional knockout mice can be successfully constructed, providing an animal model for further studying the action mechanism of Pkd1 gene in polycystic kidney disease.

Effect of FKBP38 protein on endometrial precancerous lesions and mechanism / 中国药理学通报

Aim To build the model of the gene FKBP38(FK506 binding protein 38)conditional knock out in uterus and then investigate the effect on endometrial precancerous lesions and the underlying mechanism.Methods Transgenic mice whose FKBP38 gene was flanked with loxP were constructed by embryo microinjection. The conditional knockout of FKBP38 was obtained by breeding mice harboring two loxP sites in FKBP38(FKBP38

Construction of a novel time-specific NLRP3 transgenic mouse model by Cre-LoxP system / 中国药理学通报

Aim To construct and identify a new time-specific NLRP3 point mutation transgenic mouse model by Cre-LoxP system. Methods Cre-LoxP system was used to generate NL-RP3

Effectiveness evaluation of pharyngeal swabs combined with anal swabs as multidrug-resistant organisms admission screening in intensive care unit / 中国感染控制杂志

Objective To evaluate the effectiveness of pharyngeal swabs combined with anal swabs as multidrug-resistant organism(MDRO)admission screening for patients in intensive care unit(ICU),and provide reference for healthcare-associated infection(HAI)prevention and control strategies.Methods Patients who underwent MDRO admission screening by pharyngeal swabs combined with anal swabs within 24 hours of admission to an ICU of a hospital in Shanghai from August 1 to December 31,2022 were included as the experimental group,and those who underwent MDRO admission screening only by pharyngeal swabs from August 1 to December 31,2021 were as the control group.Positive rate of screening,occurrence and pathogen of HAI between the two groups,as well as the sensitivity and specificity of combined admission screening for MDRO in the experimental group were compared.Results A total of 917 patients were included in the study,with 442 cases in the experimental group and 475 cases in the control group.The positive rates of admission screening for MDRO in the experimental and control groups were 7.40％and 3.37％,respectively.The incidences of HAI with MDRO in the experimental and control groups were 2.71％and 5.68％,respectively.Incidences of digestive system HAI with MDRO in the experimental and control groups were 0.68％and 2.32％,respectively.Differences were all statistically significant(all P＜0.05).The area under the ROC curve of admission screening by pharyngeal swabs combined with anal swabs for predicting HAI with MDRO in patients were 0.897(P＜0.01,95％CI:0.802-0.993).The sensitivity and specificity of admi-ssion screening for MDRO by pharyngeal swabs combined with anal swabs in the experimental group were 72.73％and 97.65％,respectively.Conclusion The combination of pharyngeal swabs and anal swabs can be used as an ICU admission screening method for MDRO,and has an important clinical application value.

Effect of improving cleaning and disinfection methods on the prevention,control and disinfection of CRE in burn plastic surgery ward / 中国感染控制杂志

Objective To explore the effect of improving cleaning and disinfection methods on the prevention,con-trol and disinfection of carbapenem-resistant Enterobacterales(CRE)in burn plastic surgery ward.Methods 297 patients who admitted to the department of burn plastic surgery in a hospital from February 1 to August 31,2021 were selected as the control group,and 210 patients who admitted to the hospital from September 1,2021 to Febru-ary 28,2022 after cleaning and disinfection methods improved were selected as the intervention group.Detection rate of CRE from patients,incidence of healthcare-associated infection(HAI)with CRE,and detection rate of envi-ronmental CRE before and after intervention were statistically analyzed and compared.Results The incidence of HAI and detection rate of CRE from patients in the intervention group were 0.95％and 0,respectively,lower than 4.04％and 2.02％in the control group(both P＜0.05).Compared to the control group,qualified rates of detec-tion of air and surface microbiology,adenosine triphosphate(ATP)bioflorescence and fluorescence labeling in the intervention group were all higher(x2=5.52,13.08,6.66,and 15.01,respectively,all P＜0.05).Conclusion Improving cleaning and disinfection method can reduce the incidence of HAI and the detection rate of CRE in burn wards,improve the surface cleanliness of environmental objects,as well as the effectiveness of HAI prevention and control.

Construction of macrophage-specific MST1 knockout mouse model / 安徽医科大学学报

Objective @# To establish myeloid ( including macrophage and granulocyte) specific knockout mice of mammalian sterile line 20-like kinase 1 (MST1) gene for furtherinvestigating the role and the mechanism of MST1 in macrophages in related clinical diseases．@*Methods @#Mst1flox/flox LysM-Cre ( referred to as Mst1ΔM/ΔM hereafter) mice were generated by crossing Mst1flox/floxwith lysozyme (Lysm-Cre) mice．The loxP site and Cre gene were amplified by PCR for genotyping．The knockdown efficiency of MST1 in macrophages was verified by quantitative PCR and immunofluorescence．The main immune cell populations in the livers were detected by flow cytometry. @*Results@#Mst1flox/flox LysM-Cre (Mst1ΔM/ΔM ) was the genotype of macrophage specific knockout MST1 mice．The results of qPCR and immunofluorescence showed that the knock-out efficiency of MST1 was more than 70% in bone marrow- derived macrophages and peritoneal macrophages．Flow cytometry showed that macrophage knockout of MST1 had no significant effect on the main immune cell populations in the liver of mice．@*Conclusion @# Macrophage-specific knockout of MST1 mouse model is successfully established，which lays a foundation for further investigation on the role and mechanism of macrophage MST1 in clinical related disease.

Correlation between lipoprotein-associated phospholipase A2 and albuminuria in patients with type 2 diabetes mellitus / 安徽医科大学学报

Objective@#To explore the correlation between lipoprotein-associated phospholipase A2 (Lp-PLA2) level and albuminuria in patients with type 2 diabetes mellitus (T2DM) ．@*Methods @#200 T2DM patients were chosen to collect general data and relevant laboratory indicators． According to the urinary albumin / creatinine ratio ( UACR) ，they were divided into normal group (UACR＜30 mg / g，n = 66) ，microalbuminuria group (30 mg / g≤ UACR＜300 mg / g，n = 64) and macroalbuminuria group (UACR≥300 mg / g，n = 70) ．On the basis of Lp-PLA2 tertile，they were divided into low Lp-PLA2 group (Lp-PLA2 ＜104 ng / ml，n = 66) ，medium Lp-PLA2 group ( 104 ng / ml≤Lp-PLA2 ＜161 ng / ml，n = 67) and high Lp-PLA2 group (Lp-PLA2 ≥161 ng / ml，n = 67) ．Group differences were compared by analysis of variance and nonparametric test．Associations between Lp-PLA2 and other indicators were performed by Pearson correlation and Spearman correlation. Related factors of albuminuria in T2DM patients were explored by multivariate Logistic regression analysis． In addition ，receiver operating characteristic (ROC) curve analysis was applied to evaluate the predictive value of Lp-PLA2 for albuminuria in T2DM patients. @*Results@#Lp-PLA2 was significantly higher in the macroalbuminuria group than that in both the normal group and the microalbuminuria group，and the differences were statistically significant (P＜0. 05) ．Compared with the normal group，Lp-PLA2 in the microalbuminuria group increased(P＜0. 05) ．With the increase in Lp-PLA2 tertile， there was gradual increase in UACR , and the difference was statistically significant (P＜0. 05) ．Correlation analysis showed that Lp-PLA2 was positively correlated with duration of DM，systolic blood pressure (SBP) ，glycosylated hemoglobin (HbA1c) ，fasting blood glucose (FBG) ，blood urea nitrogen (BUN) ，serum creatinine (Scr) ，UACR and negatively correlated with estimated glomerular filtration rate ( eGFR) (P ＜0. 05 ) ． Multivariate Logistic regression analysis showed that Lp-PLA2 ［OR = 1. 046，95% CI( 1. 031，1. 060) ］was an independent risk factor for albuminuria (P＜0. 05) ．The AUC of Lp-PLA2 for predicting albuminuria was 0. 902 ［95% CI(0. 862，0. 942) ］. The cut-off value of Lp-PLA2was 148 ng / ml，the sensitivity was 65. 7% and specificity was 98. 5%．@*Conclusion@#Lp-PLA2 is closely related to the albuminuria in T2DM patients，which provides a new method for the diagnosis and treatment of diabetic kidney disease (DKD) .

Construction and application of inducible macrophage-specific knockout GRK2 gene mice model / 安徽医科大学学报

Objective@#To establish an inducible macrophage-specific knockout G protein-coupled receptor kinase 2 ( GRK2) gene ( GRK2flox / flox Lyz2-CreERT + ) mice model．@*Methods@#GRK2flox / flox Lyz2-CreERT + mice were constructed based on Cre / LoxP system．The genotypes of GRK2flox / floxLyz2-CreERT + mice were identified by PCR amplification and agarose gel electrophoresis．After the mice were sacrificed by carbon dioxide method，the expression of GRK2 in bone marrow-derived macrophages ( BMDMs) and peritoneal macrophages ( PMs) was detected by Western blot．Immunofluorescence was used to detect GRK2 expression in mouse brain，heart and spleen macrophages．The M1 / M2 ratio in PMs induced by prostaglandin E2 (PGE2) was analyzed by flow cytometry. @*Results@#The results of genotype identification showed that the mice with a band at 355 bp in the length of the flox amplification product and a band at 355 bp in the length of the Cre amplification product were GRK2flox / floxLyz2-CreERT + mice．Western blot results showed that GRK2 expression in BMDMs and PMs of GRK2flox / floxLyz2-CreERT + mice decreased compared with GRK2flox / flox mice(P＜0. 01) ．Immunofluorescence results showed that GRK2 expression decreased in the brain，heart and spleen of GRK2flox / floxLyz2-CreERT + mice compared with GRK2flox / flox mice (P < 0. 01) ．Flow cytometry showed that compared with GRK2flox / flox mice，there was no significant difference in the proportion of CD86 / CD206 in the PMs of GRK2flox / floxLyz2-CreERT + mice．Under PGE2 ( 10 μmol / L) stimulation， the proportion of CD86 / CD206 in GRK2flox / floxLyz2-CreERT + mice PMs increased (P ＜0. 01) ．The proportion of CD86 / CD206 in the PMs of GRK2flox / flox mice was higher than that of GRK2flox / floxLyz2-CreERT + mice(P＜0. 01) . @*Conclusion @#In this study，GRK2flox / floxLyz2-CreERT + mice model was successfully constructed，and the mice promoted PGE2-induced polarization of PMs to M2-type macrophages compared with control mice.

DETECTION OF CARBAPENEMASE PRODUCING ENTEROBACTERALES AMONG THE CLINICAL ISOLATES OF DIARRHOEAGENIC ESCHERICHIA COLI CAUSING ACUTE GASTROENTERITIS IN CHILDREN BELOW 2 YEARS IN TERTIARY CARE HOSPITAL OF NORTH EAST INDIA.

Introduction: Enterobacterales that test resistant to at least one of the carbapenem antibiotics (ertapenem, meropenem, doripenem, or imipenem) are called Carbapenem resistant Enterobacterales (CRE) and if they produce a carbapenemase (an enzyme that can make them resistant to carbapenem antibiotics) they are called Carpenemase producing Enterobacterales (CPE). Children with CRE strains in fecal samples are considered as a high risk group by World Health Organization (WHO), which can spread CRE by intimate contact and travel. This cross-sectional study was conducted in the Departm Methods: ent of Microbiology, RIMS, Imphal, Manipur, India from Jan 2020 to Feb 2022. A total of 157 children under 2 years of age whose stool culture was positive for diarrhoeagenic Escherichia coli were included in the study. The modified carbapenem inactivation method (mCIM) has been done for detection of carbapenemase producers and the addition of EDTA in eCIM to further differentiate between serine and metallo-?-lactamase producers. Out of 157 Result and Discussion: Diarrhoegenic E.coli (DEC) ,Carbapenem resistance was seen in 9 isolates i.e 5.7 %. Out of these 9 isolates, 3 were MBL producers tested by the phenotypic test mCIM and eCIM. All the three MBL producers carried bla NDM-1 gene. mCIM/eCIM assay is designed to simultaneously detect and distinguish the different types of carbapenemases. Carbapenemase genes are often located on plasmids that can be exchanged between Enterobacteriaceae and other Gram-negative bacteria. Carbapenem-resistant K. pneumoniae are currently more frequent and more likely to cause healthcareassociated outbreaks, carbapenem-resistant E. coli pose a greater risk for spread in the community. Conclusion: Screening for carbapenemase producer using mCIM and eCIM essay is important along with infection control measure such as active surveillance through rectal screening for CRE carriage on hospital admission, contact precautions, hand hygiene, patient isolation, environmental sanitation, case notification/fiagging, antibiotic restriction.

Effect of Rheb1 in the Development of Mouse Megakaryocyte-Erythroid Progenitor Cells / 中国实验血液学杂志

OBJECTIVE@#To investigate the effect of Rheb1 in the development of mouse megakaryocyte-erythroid progenitor cells and its related mechanism.@*METHODS@#Rheb1 was specifically knocked-out in the hematopoietic system of Vav1-Cre;Rheb1fl/fl mice(Rheb1Δ/Δ mice). Flow cytometry was used to detect the percentage of red blood cells in peripheral blood and erythroid cells in bone marrow in Vav1-Cre;Rheb1fl/fl mice and control mice. The CFC assay was used to detect the differentiation ability of Rheb1 KO megakaryocyte-erythroid progenitor cells and control cells. Real-time fluorescence quantification PCR was used to detect the relative expression of PU.1,GATA-1,GATA-2,CEBPα and CEBPβ of Rheb1 KO megakaryocyte-erythroid progenitor cells and control cells. Rapamycin was added to the culture medium, and it was used to detect the changes in cloning ability of megakaryocyte-erythroid progenitor cells from wild-type mice in vitro.@*RESULTS@#After Rheb1 was knocked out, the development and stress response ability of megakaryocyte-erythroid progenitor cells in mice were weaken and the differentiation ability of megakaryocyte-erythroid progenitor cells in vitro was weaken. Moreover, the expression of GATA-1 of megakaryocyte-erythroid progenitor cells was decreased. Further, rapamycin could inhibit the differentiative capacity of megakaryocyte-erythroid progenitor cells in vitro.@*CONCLUSION@#Rheb1 can regulate the development of megakaryocyte-erythroid progenitor cells probably through the mTOR signaling pathway in mice.

Chemo-photothermal immunotherapy for eradication of orthotopic tumors and inhibition of metastasis by intratumoral injection of polydopamine versatile hydrogels

Cancer remains one of the leading causes of death globally and metastasis always leads to treatment failure. Here, we develop a versatile hydrogel loading photothermal agents, chemotherapeutics, and immune-adjuvants to eradicate orthotopic tumors and inhibit metastasis by combinational therapy. Hydrogel networks were synthesized via the thiol-Michael addition of polydopamine (PDA) with thiolated hyaluronic acid. PDA acted as a cross-linking agent and endowed the hydrogel with excellent photothermal property. Meanwhile, a chemotherapeutic agent, doxorubicin (DOX), was loaded in the hydrogel via π‒π stacking with PDA and an immune-adjuvant, CpG-ODN, was loaded via electrostatic interaction. The release of DOX from the hydrogel was initially slow but accelerated due to near infrared light irradiation. The hydrogels showed remarkably synergistic effect against 4T1 cancer cells and stimulated plenty of cytokines secreting from RAW264.7 cells. Moreover, the hydrogels eradicated orthotopic murine breast cancer xenografts and strongly inhibited metastasis after intratumoral injection and light irradiation. The high anticancer efficiency of this chemo-photothermal immunotherapy resulted from the strong synergistic effect of the versatile hydrogels, including the evoked host immune response. The combinational strategy of chemo-photothermal immunotherapy is promising for highly effective treatment of breast cancer.

A point-prevalence survey of carbapenem-resistant Enterobacteriaceae in two different cities in Kuwait and Nigeria

Background: The family Enterobacteriaceae belongs to the order Enterobacterales, a large diverse group of Gramnegative, facultatively anaerobic bacteria that sometimes cause multidrug-resistant infections which treatment options are often challenging. They are the leading cause of nosocomial bloodstream infection (BSI) and urinary tract infections (UTI). The objective of the study was to carry out a point-prevalence survey of antimicrobial resistance and carbapenem-resistant Enterobacteriaceae (CRE) clinical isolates in two hospitals in Kuwait and Nigeria. Methodology: Clinically significant bacterial isolates of patients from Kuwait and Nigeria, identified by VITEK-2 and MALDI-TOF mass spectrometry analysis were studied. Susceptibility testing of selected antibiotics was performed using E-test and broth dilution methods. Genes encoding carbapenemase, ß-lactamases, and extended-spectrum ßlactamases (ESBLs) were detected by conventional PCR and sequencing, and whole genome sequencing (WGS) analyses. Results: Of 400 isolates from Kuwait and Nigeria, 188 (47.0%) and 218 (54.5%) were Escherichia coli and 124 (31.0%) and 116 (29.0%) Klebsiella pneumoniae, respectively. The prevalence of CRE was 14.0% in Kuwait and 8.0% in Nigeria. The resistance rates of CRE isolates against colistin and tigecycline in Kuwait were 6.6% versus 25.0%, and in Nigeria were 14.2% versus 14.2%, respectively. blaOXA-181 gene was the commonest in CRE isolates in Kuwait and blaNDM-7 in Nigeria. The commonest ESBL gene among the CRE isolates was blaCTX-M-15 in both countries. AmpC resistance genes were present in only Kuwait isolates and mediated by blaEBC, blaCIT and blaDHA. WGS analysis of 12 selected CRE isolates with carbapenem MICs>32µg/ml but no detectable genes from conventional PCR, revealed the presence of multidrug efflux pump genes such as major facilitator superfamily antibiotic efflux pump and resistance-nodulation-cell division antibiotic efflux pump groups. Conclusion: The prevalence of CRE was higher among isolates from Kuwait than Nigeria and the genes encoding resistance in CRE were different. The presence of efflux pump was a main mechanism of resistance in most of the Nigerian CRE isolates.

Pure photosensitizer-driven nanoassembly with core-matched PEGylation for imaging-guided photodynamic therapy

Pure drug-assembled nanomedicines (PDANs) are currently under intensive investigation as promising nanoplatforms for cancer therapy. However, poor colloidal stability and less tumor-homing ability remain critical unresolved problems that impede their clinical translation. Herein, we report a core-matched nanoassembly of pyropheophorbide a (PPa) for photodynamic therapy (PDT). Pure PPa molecules are found to self-assemble into nanoparticles (NPs), and an amphiphilic PEG polymer (PPa-PEG

Influence of specifically knocking out AMP-activated protein kinase α1 subunit gene in excitatory neurons in brain energy metabolism and cognitive function in mice / 中华神经医学杂志

Objective:To investigate the changes of brain energy metabolism and cognitive function in mice with specifically knocking out AMP-activated protein kinase α1 subunit ( AMPKα1) gene in the excitatory neurons by Cre-loxP recombination system. Methods:Sixteen 6-month-old mice with genotype AMPKα1 flox/flox/Camk2a-Cre/ERT2 obtained by hybrid breeding were randomly divided into AMPKα1 knockout group ( n=8) and AMPKα1 wild-type group ( n=8). Mice in the AMPKα1 knockout group were intraperitoneally injected 0.1 mL tamoxifen (20 mg/mL, dissolved in corn oil) daily for a consecutive 5 d to control AMPKα1 gene knockout in the excitatory neurons; and mice in the AMPKα1 wild-type group were intraperitoneally injected 0.1 mL corn oil daily for a consecutive 5 d. Seven d after that, Morris water maze and T maze experiments were employed to detect the spatial learning and memory abilities and spatial working memory of these mice; chemical exchange saturation transfer imaging (CEST) was used to observe the glucose metabolism in the hippocampus and cortex surrounding the hippocampus; Western blotting was used to detect the AMPKα1 and glutamate receptor 1 (GluR1) protein expressions in the hippocampus and cortex surrounding hippocampus of two groups. Results:(1) Morris water maze showed that, as compared with those in the AMPKα1 wild-type group, mice in the AMPKα1 knockout group had significantly prolonged escape latency ([13.90±3.72] s vs. [22.40±6.28] s; [11.95±3.86] s vs. [22.39±9.77] s]) on the 3 rd and 4 th d of experiment, statistically decreased times crossing the platform ([5.25±1.83] times vs. [1.75±1.28] times, P<0.05). (2) T-maze experiment showed that as compared with that of the AMPKα1 wild-type group, the free alternation rate in mice of the AMPKα1 knockout group was significantly decreased ([73.21±9.16]% vs. [48.21±11.29]%, P<0.05). (3) CEST showed that the glucose metabolism levels in the hippocampus and cortex surrounding the hippocampus of AMPKα1 knockout group were significantly lower than those in AMPKα1 wild-type group (1.51±0.81 vs. 2.77±0.67; 1.31±0.83 vs. 2.42±0.95, P<0.05). (4) Western blotting showed that the AMPKα1 and GluR1 protein expressions in the hippocampus and cortex surrounding the hippocampus of the AMPKα1 wild-type group were significantly higher than those of the AMPKα1 knockout group (AMPKα1: 0.70±0.05 vs. 0.49±0.03, 0.98±0.04 vs. 0.64±0.06; GluR1: 1.22±0.18 vs. 0.60±0.11, 0.96±0.08 vs. 0.79±0.04, P<0.05). Conclusion:Specifically knocking out AMPKα1 in excitatory neurons can result in abnormal glucose metabolism in the brain of mice, and thus cause cognitive dysfunction, whose mechanism may be related to excitatory synaptic disorder caused by energy metabolism disorder.