Daptomycin and linezolid for severe methicillin-resistant Staphylococcus aureus psoas abscess and bacteremia:A case report and review of the literature

BACKGROUND Vancomycin remains a first-line treatment drug as per the treatment guidelines for methicillin-resistant Staphylococcus aureus(MRSA)bacteremia.However,a number of gram-positive cocci have developed resistance to several drugs,including glycopeptides.Therefore,there is an urgent need for effective and innovative antibacterial drugs to treat patients with infections caused by drugresistant bacteria.CASE SUMMARY A 24-year-old male was admitted to hospital owing to lumbago,fever,and hematuria.Computed tomography(CT)results showed an abscess in the psoas major muscle of the patient.Repeated abscess drainage and blood culture suggested MRSA,and vancomycin was initiated.However,after day 10,CT scans showed abscesses in the lungs and legs of the patient.Therefore,treatment was switched to daptomycin.Linezolid was also added considering inflammation in the lungs.After 10 d of the dual-drug anti-MRSA treatment,culture of the abscess drainage turned negative for MRSA.On day 28,the patient was discharged without any complications.CONCLUSION This case indicates that daptomycin combined with linezolid is an effective remedy for bacteremia caused by MRSA with pulmonary complications.

The Effects of Liquor Spirits on RNA Pol III Genes and Cell Growth of Human Cancer Lines

Alcohol consumption is a major health issue and associated with human cancers, such as liver and breast cancers. Alcohol was classed as carcinogen to human by IARC. We have performed in vivo and in vitro studies which demonstrate that diluted ethanol promotes cell proliferation and transformation and tumor formation. Consumption of liquor spirits (white wines) is a popular behavior. However, it is unclear whether liquor spirits affect cellular phenotypes of human cancers. At present study, we used diluted ethanol and liquor spirits (Sample #1 and Sample #2) to determine the changes in RNA polymerase III-dependent gene (Pol III gene) transcription, cell growth and colony formation in the different human cancer lines. The results indicate that low concentration of ethanol increases RNA Pol III gene transcription and rate of cell growth. However, both liquor spirits (Sample #1 and Sample #2) inhibit the activity of RNA Pol III genes and repress cell proliferation of the cancer lines, compared to diluted ethanol. The liquor spirits reduce the rate of colony formation of human breast cancer cells and esophageal carcinoma cells. The inhibitions of the liquor spirits to RNA Pol III genes, cell growth and colony formation are in a dose-dependent manner. These new findings suggest that the liquor spirits contain some active components to repress Pol III gene transcription and cell growth caused by ethanol in different human cancer cells.

VEGF-expressing Bone Marrow Mesenchymal Stem Cells Transplantation Improved Heart Function of Myocardial Infarct Rabbits

Objectives To treat myocardial infarction with MSCs transplantation combined with VEGF gene therapy in rabbits and to study its mechanisms. Methods Forty-eight rabbits were randomly divided into MI group （n=12）, MSCs group （n=12）, VEGF group （n=12）, MSCs＋VEGF group （M＋V group, n=12）. Rabbit myocardial infarction models were founded by the ligation of left anterior descending artery. 107 MSCs were injected into the infarct-zone in four sites 2 weeks later in MSCs and M＋ V group, phVEGF gene were injected in infarct-zone in VEGF group and MSCs transfected with phVEGF gene were injected in M＋V group. Heart function including LVEDP, LVSP, LVDP, -dp/dtmax, ＋dp/dtmax, were measured in vivo. The hearts were harvested at 4 weeks after transplantation and sectioned for HE stain, immunohistochemical stain of BrdU and VIII factor antigen. Results The left ventricular hemodynamics parameters showed that heart function were improved more in M＋V group than MSCs group, MI group and VEGF group. The numbers of BrdU positive cells in M＋ V group（61±8）were more than in MSCs group （44±8, P 〈 0.01）. The numbers of vessels in infarcted zone were more in M＋V group （49±8） than in MSCs group （33±6, P 〈 0.01）,VEGF group（30±8, P 〈 0.01）and Mlgroup （18±4, P〈0.01）. Conclusions VEGF-expressing MSCs transplantation could improve heart function after myocardial infarction, and they were more effective than sole MSCs transplantation. Keeping more MSCs survival and ameliorating the blood supply of infarct-zone might be involved in the mechanisms.

Inhibition of cervical cancer cell proliferation and cervical tumorigenicity caused by farnesoid X receptor activation or over-expression is related to CDKN2A-p14^(ARF)-MDM2-p53 pathway

OBJECTIVE Cervical cancer is the third most malignant tumor in the world.Farnesoid X receptor(FXR) is a member of nuclear receptor superfamily.It is highly expressed in liver,kidney and small intestine,while it showed low expression level in other tissues.It not only plays an important role in the metabolism of bile acids and sugars,but also in the production of chronic inflammation in the early stage of cancer,the proliferation and migration of tumor.Compared with the normal tissue,the expression of FXR in most tumor tissues decreased.But there is no correlation between cervical cancer and FXR.So we aimed to find out the relationship between FXR and cervical cancer.METHODS A clinical study using q PCR,western blot and immunohistochemistry detected the expression of FXR in tumor tissues and normal tissues of clinical patients.FXR was activated by agonists or over-expressed by lentivirus.MTT,clone formation and flow cytometry were used to detect the relationship between FXR and proliferation of cervical cell lines.Tumor growth ability of FXR was detected by nude mice tumorigenicity.The interaction between FXR and CDKN2A-p14^(ARF)-MDM2-p53 pathway was detected by q PCR,Western blot and immunohistochemistry.RESULTS FXR was decreased in cancer tissues compared to normal control.Activation of FXR by agonist or constitutively-over-expression of FXR inhibited cervical cell proliferation.Over-expressed FXR attenuated Caski,Hela and Siha xenograft tumor growth in nude mice compared with control.Over-expression of FXR caused G1 cell-cycle arresting and up-regulated CDKN2A-p14^(ARF)-MDM2-p53 pathway.CONCLUSION FXR inhibits cervical cancer cell proliferation and cervical tumorigenicity which is related to CDKN2A-p14^(ARF)-MDM2-p53 pathway.Activation or overexpression of FXR may be a potential target for the treatment of cervical cancer.

Fundamentals of the Warburg Effect in Cancer

As the fundamental energy unit of most cells,the ATP generated from glucose is vital to maintain biological processes such as the synthesis of proteins and nucleic acids.However,a common feature of cancer cells is an altered metabolism with increased glucose uptake and the fermentation of glucose to lactate even in the presence of normal mitochondria.This phenomenon is known as the‘Warburg effect’(now termed aerobic glycolysis).One simple explanation for this effect is that it permits cells to more easily produce energy to support rapid growth.It can also help to meet the biosynthetic requirements for pyruvate as a major building block.As a well-known metabolic hallmark of cancer cells,the role of the Warburg effect in oncology is a newly-emerging area of growing interest.In this perspective,we provide some new understanding of these mechanisms based on recent progress in research on cancer metabolism.The better understanding of these mechanisms will support the development of new therapeutic strategies that take into account tumor nutrition and energy metabolism.

Differentiation of Rabbit Bone Marrow Mesenchymal Stem Cells to Myogenic Cells and Expression of VEGF After Gene Transfection

Objectives To induce the differentiation of rabbit bone marrow mesenchymal stem cells （MSCs） to myogenic cells in vitro, and to investigate the expression of vascular endothelial growth factor （VEGF） gene in MSCs transfected by AdTrackCMV-VEGF165. Methods MSCs were isolated and purified from rabbit bone marrow by percoll （11）73 g/ml） and then cultured in low glucose DMEM with 10% FBS. AdTrackCMV-VEGF165 eukaryotic expression vector was constructed and transfected into the MSCs. After being incubated with 5-azacytidine （5- Aza）, the expression of troponin I in MSCs was assayed by immunohistochemistry and the expression of VEGF gene was identified by northern blot and western blot. The concentration of VEGF in the supernatant was measured by ELASA. Results MSCs were isolated and cultured successfully from rabbit bone marrow. The positive cTnI stain of some MSCs after the induction of 5-aza indicated that the cells were differentiated to myogenic cells. Northern blot and western blot showed that the expression of VEGF 165 mRNA was much higher in the hVEGF165 gene transfected cells than that of the control. The concentration of VEGF in the supernatant got to the peak 3-5 days after hVEGF165 gene transfection （1011- 1027 pg/ml） and decreased gradually thereafter, but still higher than that of control group or pAdTrackCMV group （349 pg/mLvs 116 pg/mL or 125pg/ml respectively, MSCs could be induced P〈 0.01）. Conclusions to differentiate to myogenic cells by 5-aza in vitro and could express VEGF by VEGF gene transfection.

Endoplasmic reticulum stress-induced apoptosis in the penumbra aggravates secondary damage in rats with traumatic brain injury

Neuronal apoptosis is mediated by intrinsic and extrinsic signaling pathways such as the membrane-mediated,mitochondrial,and endoplasmic reticulum stress pathways.Few studies have examined the endoplasmic reticulum-mediated apoptosis pathway in the penumbra after traumatic brain injury,and it remains unclear whether endoplasmic reticulum stress can activate the caspase-12-dependent apoptotic pathway in the traumatic penumbra.Here,we established rat models of fluid percussion-induced traumatic brain injury and found that protein expression of caspase-12,caspase-3 and the endoplasmic reticulum stress marker 78 k Da glucose-regulated protein increased in the traumatic penumbra 6 hours after injury and peaked at 24 hours.Furthermore,numbers of terminal deoxynucleotidyl transferase-mediated d UTP nick end labeling-positive cells in the traumatic penumbra also reached peak levels 24 hours after injury.These findings suggest that caspase-12-mediated endoplasmic reticulum-related apoptosis is activated in the traumatic penumbra,and may play an important role in the pathophysiology of secondary brain injury.

Emergence of hypervirulent Pseudomonas aeruginosa pathotypically armed with co-expressed T3SS effectors ExoS and ExoU

Pseudomonas aeruginosa is a significant pathogen mainly causing healthcare-associated infections(HAIs).Newly emerging high-risk clones of P.aeruginosa with elevated virulence profiles furtherly cause severe community-acquired infections(CAIs).Usually,it is not common for P.aeruginosa to co-carry exoU and exoS genes,encoding two type III secretion system(T3SS)effectors.The pathogenicity mechanism of exoS+/exoU+strains of P.aeruginosa remains unclear.Here,we provide detailed evidence for a subset of hypervirulent P.aeruginosa strains,which abundantly co-express and secrete the T3SS effectors ExoS and ExoU.The exoS+/exoU+P.aeruginosa strains were available to cause both HAIs and CAIs.The CAI-associated strains could elicit severe inflammation and hemorrhage,leading to higher death rates in a murine acute pneumonia model,and had great virulence potential in establishing chronic infections,demonstrating hypervirulence when compared to PAO1(exoS+/exoU-)and PA14(exoS-/exoU+).Both ExoS and ExoU were co-expressed and co-secreted in abundance in exoS+/exoU+strains.Their abundant protein secretion could boost exoS+/exoU+strains’potentials for cytotoxicity in vitro and pathogenicity in vivo.Genomic evidence indicates that exoU acquisition is likely mediated by horizontal gene transfer(HGT)of the pathogenicity island PAPI-2,while deletion of exoU was sufficient to mitigate virulence in the exoS+/exoU+strains.Furthermore,bioinformatics analysis showed that such exoS+/exoU+P.aeruginosa strains turned out to be widely distributed across the globe.Overall,the research provide detailed evidence for the high virulence and epidemicity of exoS+/exoU+strains of P.aeruginosa,highlighting an urgent need for surveillance against these high-risk hypervirulent strains.

PXR:a center of transcriptional regulation in cancer

Pregnane X receptor(PXR,NR 112)is a prototypical member of the nuclear receptor superfamily.PXR can be activated by both endobiotics and xenobiotics.As a key xenobiotic receptor,the cellular function of PXR is mostly exerted by its binding to the regulatory gene sequences in a liganddependent manner.Classical downstream target genes of PXR participate in xenobiotic responses,such as detoxification,metabolism and inflammation.Emerging evidence also implicates PXR signaling in the processes of apoptosis,cell cycle arrest,proliferation,angiogenesis and oxidative stress,which are closely related to cancer.Here,we discussed,in addition to the characterization of PXR per se,the biological function and regulatory mechanism of PXR signaling in cancer,and its potential for the targeted prevention and therapeutics.

Genome-wide expression profiling of the response to terbinafine in Candida albicans using a cDNA microarray analysis

Background Candida albicans is the most frequently seen opportunistic human fungal pathogen. Terbinafine is an allylamine antifungal agent that has been proven to have high clinical efficacy in the therapy of fungal infections, the mechanism of action of terbinafine involves the specific inhibition of fungal squalene epoxidase, resulting in ergosterol deficiency and accumulation of intracellular squalene. We used cDNA microarray analysis technology to monitor global expression profile changes of Candida albicans genes in response to terbinafine treatment, and we anticipated a panoramic view of the responses of Candida albicans cells to the representatives of allylamine antifungal agents at the molecular level in an effort to identify drug class-specific and mechanism-independent changes in gene expression.Methods Candida albicans strain ATCC 90028 was exposed to either medium alone or terbinafine at a concentration equivalent to the 1/2 minimal inhibitory concentrations （MICs, 4 mg/L） for 90 minutes. RNA was isolated and gene expression profiles were compared to identify the changes in the gene expression profile using a cDNA microarray analysis. Differential expression of 10 select genes detected by cDNA microarray analysis was confirmed by semi-quantitative reverse transcription-polymerase chain reaction （RT-PCR）. Results A total of 222 genes were found to be responsive to terbinafine, including 121 up-regulated genes and 101 down-regulated genes. These included genes encoding membrane transport proteins belonging to the members of the ATP-binding cassette （ABC） or major facilitator supeffamily （MFS; CDR1, AGP2, GAP6, PHO84, HOL3, FCY23, VCX1）, genes involved in stress response and detoxification （CDR1, AGP2, HOL3）, and gene involved in the ergosterol biosynthesis pathway （ERG12）. The results of semi-quantitative RT-PCR were consistent with that of the cDNA microarray analysis. Conclusions The up-regulation of the gene encoding the multidrug resistance efflux pump CDR1 may contribute to the terbinafine resistance in Candida albicans. However, the precise roles of other affected genes remain unclear, further studies of these genes and their respective products that play roles in the context of antifunqal resistance are warranted.

Oncolytic Activity of Wild-type Newcastle Disease Virus HK84 Against Hepatocellular Carcinoma Associated with Activation of Type I Interferon Signaling

Background and Aims:Hepatocellular carcinoma(HCC)is listed as one of the most common causes of cancer-related death.Oncolytic therapy has become a promising treatment because of novel immunotherapies and gene editing technology,but biosafety concerns remain the biggest limitation for clinical application.We studied the the antitumor activity and biosafety of the wild-type Newcastle disease virus HK84 strain(NDV/HK84)and 10 other NDV strains.Meth-ods:Cell proliferation and apoptosis were determined by cell counting Kit-8 and fluorescein isothiocyanate Annexin V apoptosis assays.Colony formation,wound healing,and a xenograft mouse model were used to evaluate in vivo and in vitro oncolytic effectiveness.The safety of NDV/HK84 was tested in nude mice by an in vivo luciferase imaging system.The replication kinetics of NDV/HK84 in normal tis-sues and tumors were evaluated by infectious-dose assays in eggs.RNA sequencing analysis was performed to explore NDV/HK84 activity and was validated by quantitative real-time PCR.Results:The cell counting Kit-8 assays of vi-ability found that the oncolytic activity of the NDV strains differed with the multiplicity of infection(MOI).At an MOI of 20,the oncolytic activity of all NDV strains except the DK/JX/21358/08 strain was>80%.The oncolytic activities of the NDV/HK84 and DK/JX/8224/04 strains were>80%at both MOI=20 and MOI=2.Only NDV/HK84 had>80%oncolytic activities at both MOI=20 and MOI=2.We chose NDV/HK84 as the candidate virus to test the oncolytic effect of NDV in HCC in the in vitro and in vivo experiments.NDV/HK84 killed human SK-HEP-1 HCC cells without affecting healthy cells.Conclusions:Intratumor infection with NDV/HK84 strains compared with vehicle controls or positive controls indicated that NDV/HK84 strain specifically inhib-ited HCC without affecting healthy mice.High-throughput RNA sequencing showed that the oncolytic activity of NDV/HK84 was dependent on the activation of type I interferon signaling.

Newcastle Disease Virus/HK84:Next Potential Star for Targeted Immunotherapy of Hepatocellular Carcinoma?

Of all liver cancers,hepatocellular carcinoma(HCC)is reported as the most common globally,with the highest incidence in East Asia.1 Because of the late diagnosis of disease,HCC is one of the top causes of cancer-related mortality,with the poor overall prognosis,the survival rate largely depends on the stage of diagnosis,the extent of cirrhosis,other associated risk factors and the medical treatment.1,2 Therefore,there is urgent need for reliable HCC treatments,which re-quires further investigation and research.In addition to traditional cancer therapy,such as surgery and chemotherapy,immunotherapy has recently undergone rapid development and now includes checkpoint inhibitors,inhibiting cytokine blockade,adoptive cellular therapies and vaccines,which are under investigation in preclinical and/or in clinical trials.However,the currently available immunotherapy regimens for HCC under investigation have shown limited effectiveness in a relatively small number of patients.

Interaction of Hepatitis B Virus X Protein with the Pregnane X Receptor Enhances the Synergistic Effects of Aflatoxin B1 and Hepatitis B Virus on Promoting Hepatocarcinogenesis

Background and Aims:Hepatitis B virus(HBV)infection has been found to increase hepatocellular sensitivity to carcinogenic xenobiotics,by unknown mechanisms,in the generation of hepatocellular carcinoma.The pregnane X receptor(PXR)is a key regulator of the body’s defense against xenobiotics,including xenobiotic carcinogens and clinical drugs.In this study,we aimed to investigate the molecular mechanisms of HBV X protein(HBx)-PXR signaling in the synergistic effects of chemical carcinogens in HBV-associated hepatocarcinogenesis.Methods:The expression profile of PXR-cytochrome p4503A4(CYP3A4)signaling was determined by PCR,western blotting,and tissue microarray.Cell viability and aflatoxin B1(AFB1)cytotoxicity were measured using the cell counting kit-8 assay.Target gene expression was evaluated using transient transfection and real time-PCR.The genotoxicity of AFB1 was assessed in newborn mice with a single dose of AFB1.Results:HBx enhanced the hepatotoxicity of AFB1 by activating CYP3A4 and reducing glutathione Stransferase Mu 1(GSTM1)in cell lines.Activation of PXR by pregnenolone 16α-carbonitrile increased AFB1-induced liver tumor incidence by up-regulating oncogenic KRAS to enhance interleukin(IL)-11:IL-11 receptor subunit alpha-1(IL11RA-1)-mediated inflammation in an HBx transgenic model.Conclusions:Our finding regarding AFB1 toxicity enhancement by an HBx-PXR-CYP3A4/GSTM1-KRASIL11:IL11RA signaling axis provides a rational explanation for the synergistic effects of chemical carcinogens in HBV infection-associated hepatocarcinogenesis.

Comparative Genomics Reveals Evolutionary Drivers of Sessile Life and Left-right Shell Asymmetry in Bivalves

Bivalves are species-rich mollusks with prominent protective roles in coastal ecosystems.Across these ancient lineages,colony-founding larvae anchor themselves either by byssus production or by cemented attachment.The latter mode of sessile life is strongly molded by left-right shell asymmetry during larval development of Ostreoida oysters such as Crassostrea hongkongensis.Here,we sequenced the genome of C.hongkongensis in high resolution and compared it to reference bivalve genomes to unveil genomic determinants driving cemented attachment and shell asymmetry.Importantly,loss of the homeobox gene Antennapedia(Antp)and broad expansion of lineagespecific extracellular gene families are implicated in a shift from byssal to cemented attachment in bivalves.Comparative transcriptomic analysis shows a conspicuous divergence between leftright asymmetrical C.hongkongensis and symmetrical Pinctada fucata in their expression profiles.Especially,a couple of orthologous transcription factor genes and lineage-specific shell-related gene families including that encoding tyrosinases are elevated,and may cooperatively govern asymmetrical shell formation in Ostreoida oysters.