Methicillin-resistant Staphylococcus aureus (MRSA) is a major nosocomial pathogen that causes a variety of infections. MRSA has evolved resistance to multiple antibiotics. Genetic background and virulence differs in different geographic regions. The present study was aimed to investigate the prevalence of enterotoxin genes and spa genotypes of hospital-associated methicillin-resistant Staphylococcus aureus (HA-MRSA) isolated from a tertiary care hospital of Jiangsu province, China.
Materials and Methods
HA-MRSA isolates from August 2013 to April 2014 at a tertiary care hospital of China were collected. We investigated antimicrobial pattern, spa types, SCCmec types and the presence of 14 virulence genes.
Eighty HA-MRSA isolates were collected. Results from SCCmec typing revealed that 73.8% were type II; 13.8% were type III; 12.5% were type V. There were 19 different spa types. Spa type t2460 was the most common (35.0%), followed by t002 (11.3%). CC5 was the predominant MLST CCs type (50%). The most frequent toxin genes were sea, seb, sed, sel, sen and seo (100.0%). None of the investigated isolates carried the sec or tst.
Genotypic and virulence evaluation of the isolated HA-MRSA revealed that the isolates with CC5 and SCCmec II were the predominant type and highly homological. The virulence profiles mainly existed in the genes of sea, seb, sed, sel, sen, seo and ser. The prevalence of t2460 was an outbreak and the predominant spa type.
sea; seb; sed; sel; sen; seo; ser; t2460
The gut microbiota is commonly referred to as a hidden organ due to its pivotal effects on host physiology, metabolism, nutrition and immunity. The gut microbes may be shaped by environmental and host genetic factors, and previous studies have focused on the roles of protein-coding genes. Here we show a link between long non-coding RNA (lncRNA) expression and gut microbes. By repurposing exon microarrays and comparing the lncRNA expression profiles between germ-free, conventional and different gnotobiotic mice, we revealed subgroups of lncRNAs that were specifically enriched in each condition. A nearest shrunken centroid methodology was applied to obtain lncRNA-based signatures to identify mice in different conditions. The lncRNA-based prediction model successfully identified different gnotobiotic mice from conventional and germ-free mice, and also discriminated mice harboring transplanted microbes from fecal samples of mice or zebra fishes. To achieve optimal prediction accuracy, fewer lncRNAs were required in the prediction model than protein-coding genes. Taken together, our study demonstrated the effecacy of lncRNA expression profiles in discriminating the types of microbes in the gut. These results also provide a resource of gut microbe-associated lncRNAs for the development of lncRNA biomarkers and the identification of functional lncRNAs in host-microbes interactions.
To pool reliable evidences for the optimum anterior transposition technique in the treatment of cubital tunnel syndrome by comparing the clinical efficacy of subcutaneous and submuscular anterior ulnar nerve transposition.
A comprehensive search was conducted in PubMed MEDLINE, Cochrane Library, EMBASE, Web of Science, OVID AMED, EBSCO and potentially relevant surgical archives. Risk of bias of each included studies was evaluated according to Cochrane Handbook for Systematic Reviews of Interventions. The risk ratio (RR) and 95% confidence intervals (CI) were calculated for the clinical improvement in function compared to baseline. Heterogeneity was assessed across studies, and subgroup analysis was also performed based on the study type and follow-up duration.
Three studies with a total of 352 participants were identified, and the clinically relevant improvement was used as the primary outcomes. Our meta-analysis revealed that no significant difference was observed between two comparison groups in terms of postoperative clinical improvement in those studies (RR 1.04, 95% CI 0.86 to 1.25, P = 0.72). Meanwhile, subgroup analyses by study type and follow-up duration revealed the consistent results with the overall estimate. Additionally, the pre- and postoperative motor nerve conduction velocities were reported in two studies with a total of 326 patients, but we could not perform a meta-analysis because of the lack of concrete numerical value in one study. The quality of evidence for clinical improvement was ‘low’ or ‘moderate’ on the basis of GRADE approach.
Based on small numbers of studies with relatively poor methodological quality, the limited evidence is insufficient to identify the optimum anterior transposition technique in the treatment of cubital tunnel syndrome. The results of the present study suggest that anterior subcutaneous and submuscular transposition might be equally effective in patients with ulnar neuropathy at the elbow. Therefore, more high-quality randomized controlled trials with standardized clinical improvement metrics are required to further clarify this topic and to provide reproducible pre- and postoperative objective outcomes.
Various studies have modeled the impact of test-and-treat policies on the HIV epidemics worldwide. However, few modeling studies have taken into account China’s context. To understand the potential effect of test-and-treat on the HIV epidemic among men who have sex with men (MSM) in China, we developed a mathematical model to evaluate the impact of the strategy.
Based on the natural history of the CD4 count of people living with HIV and AIDS (PLWHA), we constructed a dynamic compartmental model of HIV transmission among Chinese MSM to project the number of HIV new infections and prevalence over 10 years. We predicted the annual number of HIV new infections and the total number of MSM living with HIV and AIDS (based on Beijing data) between 2010 and 2022 under the following conditions: (1) current practice (testing rate of 50% and ART coverage of 39%); (2) both testing rate and ART coverage increasing to 70% in 2013; (3) both testing rate and ART coverage increasing to 90% in 2013; and (4) both testing rate and ART coverage increasing gradually every year until 90% since 2013.
Based on our model, if the HIV test-and-treat policy was implemented among Chinese MSM, the total number of HIV new infections over 10 years (2013-2022) would be reduced by 50.6-70.9% compared with the current policy. When ART coverage for PLWHA increased to 58% since 2013, the ‘turning point’ would occur on the curve of HIV new infections by 2015. A 25% reduction in annual number of HIV new infections by 2015 might be achieved if the testing rate increased from 50% to 70% and treatment coverage for PLWHA increased to 55% since 2013.
Implementation of the test-and-treat strategy may significantly reduce HIV new infections among MSM in China. Great efforts need to be made to scale up HIV testing rate and ART coverage among Chinese MSM.
Glucose transporter isoform-3 (GLUT3), one of the primary placental facilitative glucose transporters responsible for basal glucose transport, has a crucial role in glucose transport and fetal growth during early pregnancy. A GLUT3 mutation in mice has been reported to cause loss of early pregnancy or late-gestational fetal growth restriction. However, the underlying mechanisms that regulate the placental GLUT3 transporter in humans are largely unknown. In the present study, we used the JEG-3 human choriocarcinoma cell line, which resembles a first trimester placental model, to study the role of the mammalian target of rapamycin complex 1 (mTORC1) in the regulation of placental GLUT3. We combined rapamycin treatment and small interfering (si) RNA-mediated silencing approaches with mRNA and protein expression/localization studies to investigate the alteration of GLUT3 expression and localization following mTORC1 inhibition in JEG-3 trophoblasts. Inhibition of mTORC1 signaling by silencing raptor decreased GLUT3 mRNA expression (−41%) and protein expression (−50%). Similar effects were obtained in cells in which mTORC1 was inhibited by rapamycin. Immunofluorescence analysis revealed that GLUT3 expression was markedly reduced in the cell surface and cytoplasm of JEG-3 cells in response to mTORC1 silencing. Because placental mTORC1 activity and GLUT3 expression are decreased in human intrauterine growth restriction, our data suggested one possible mechanism for the abnormal fetal growth in this pregnancy complication.
placenta; glucose transporter isofrom-3; mammalian target of rapamycin
The binuclear coordination polymer consists of two nickel cations with different coordination environments. One has a square-planar environment whereas the other has an octahedral environment. Cyanide ligands bridge the cations into a polymeric layer structure.
The polymeric title complex, [Ni2(CN)4(C10H8N2)]n, was obtained serendipitously under hydrothermal conditions. The asymmetric unit consists of one half of an [Ni(CN)4]2− anion with the Ni2+ cation situated on an inversion centre, and one half of an [Ni(2,2′-bpy)]2+ cation (2,2′-bpy is 2,2′-bipyridine), with the second Ni2+ cation situated on a twofold rotation axis. The two Ni2+ cations exhibit different coordination spheres. Whereas the coordination of the metal in the anion is that of a slightly distorted square defined by four C-bound cyanide ligands, the coordination in the cation is that of a distorted octahedron defined by four N-bound cyanide ligands and two N atoms from the chelating 2,2′-bpy ligand. The two different Ni2+ cations are alternately bridged by the cyanide ligands, resulting in a two-dimensional structure extending parallel to (010). Within the sheets, π–π interactions between pyridine rings of neighbouring 2,2′-bpy ligands, with a centroid-to-centroid distance of 3.687 (3) Å, are present. The crystal packing is dominated by van der Waals forces. A weak C—H⋯N interaction between adjacent sheets is also observed.
crystal structure; cyanide ligands; nickel; 2,2′-bipyridine; coordination polymer
Piezo ion channels are activated by various types of mechanical stimuli and function as biological pressure sensors in both vertebrates and invertebrates. To date, mechanical stimuli are the only means to activate Piezo ion channels and whether other modes of activation exist is not known. In this study, we screened ∼3.25 million compounds using a cell-based fluorescence assay and identified a synthetic small molecule we termed Yoda1 that acts as an agonist for both human and mouse Piezo1. Functional studies in cells revealed that Yoda1 affects the sensitivity and the inactivation kinetics of mechanically induced responses. Characterization of Yoda1 in artificial droplet lipid bilayers showed that Yoda1 activates purified Piezo1 channels in the absence of other cellular components. Our studies demonstrate that Piezo1 is amenable to chemical activation and raise the possibility that endogenous Piezo1 agonists might exist. Yoda1 will serve as a key tool compound to study Piezo1 regulation and function.
Within our bodies, cells and tissues are constantly being pushed and pulled by their surrounding environment. These mechanical forces are then transformed into electrical or chemical signals by cells. This process is crucial for many biological structures, such as blood vessels, to develop correctly, and is also a key part of our senses of touch and hearing.
In 2010, researchers discovered a group of ion channels—proteins embedded in the membrane that surrounds a cell—that open up when a force is applied and allow ions such as calcium, potassium, and sodium to flow. This movement of ions generates the electrical response of the cell to the applied force. However, not much is known about how these ‘Piezo’ ion channels work. To investigate this, it is important to be able to precisely control how and when the Piezo channels open. Many other ion channels are studied by using small chemical compounds to activate them, but there were none that were known to act on Piezo proteins.
Syeda et al.—including some of the researchers involved in the 2010 work—screened over three million compounds for their ability to cause calcium ions to flow into human cells to try to identify chemicals that activate the Piezo channels. This revealed one promising candidate named Yoda1, which specifically activated Piezo1: a Piezo protein that had previously been linked to a role in blood vessel development in embryos.
To investigate how Yoda1 activates Piezo1, Syeda et al. placed Piezo1 in an artificial cell membrane that did not contain any other cellular components. When Yoda1 was added to this set up, the Piezo1 channels opened up. This suggests that Piezo1 and Yoda1 interact in a manner that does not require additional cellular components other than a cell membrane.
Separate work by Cahalan, Lukacs et al. uses Yoda1 to reveal that Piezo1 helps to control the volume of red blood cells, showing that in the future, Yoda1 could be valuable in research that investigates the roles of Piezo1.
ion channel; agonist; mechanotransduction; none
Pseudomonas aeruginosa biofilm was cultivated and characterized in a microfluidic “lab-on-a-chip” platform coupled with confocal Raman microscopy in a nondestructive manner. Biofilm formation could be quantified by this label-free platform and correlated well to confocal laser scanning microscopy. This Raman-microfluidic platform could also discriminate biofilms at different developmental stages.
It is known that cardiovascular complications plays important roles in the development of diabetes mellitus (DM) and platelet dysfunction is one of the key reasons which led to microangiopathy. This study was designed to investigate the mitochondria function changes of platelet in DM rats and DM patients. The results showed that the platelets viability, platelet adenosine triphosphate (ATP) content and platelet mitochondrial ATP content of DM rats were lower than that of normal rats; when incubated in vitro for 24 h, platelet number and mitochondrial membrane potential (MMP) of DM rats were lower than that of normal rats, reactive oxygen species (ROS) was higher than that of normal rats. For DM patients, their platelet number and ROS were higher and MMP was lower than those of normal people; when incubated in vitro for 24 h, platelet viability of DM patients was lower than that of normal people. Platelet ultra-microstructures of DM rats and DM patients were abnormal. These results suggested that platelet mitochondrial function of both DM rats and DM patients was impaired when compared to normal rats and normal people, respectively. Platelets may be applied as a biomarker to observe the mitochondrial changes during DM.
Platelet; mitochondria; oxidative stress; diabetic
Plastic film mulching (PM) has been widely used to improve maize (Zea mays L.) yields and water use efficiency (WUE) in Northeast China, but the effects of PM in a changing climate characterized by highly variable precipitation are not well understood. Six site-year field experiments were conducted in the dry and rainy years to investigate the effects of PM on maize growth, grain yield, and WUE in Northeast China. Compared to crops grown without PM treatment (control, CK), PM significantly increased the grain yield by 15-26% in the dry years, but no significant yield increase was observed in the rainy years. Yield increase in the dry years was mainly due to a large increase in dry matter accumulation pre-silking compared to the CK, which resulted from a greater dry matter accumulation rate due to the higher topsoil temperature and water content. As a result, the WUE of the crops that underwent PM (3.27 kg m-3) treatment was also increased by around 16% compared to the CK, although the overall evapotranspiration was similar between the two treatments. In the rainy years, due to frequent precipitation and scant sunshine, the topsoil temperature and water content in the field that received PM treatment was improved only at some stages and failed to cause higher dry matter accumulation, except at the 8th leaf stage. Consequently, the grain yield and WUE were not improved by PM in the rainy years. In addition, we found that PM caused leaf senescence at the late growth stage in both dry and rainy years. Therefore, in practice, PM should be applied cautiously, especially when in-season precipitation is taken into account.
Several association studies with small sample sizes of two SNPs in IL28BB (rs12979860 and rs8099917) showed inconsistent results, so in this study, we aim to evaluate the association between the two SNPs and infection susceptibility of Hepatitis B Virus (HBV) in Asian population, especially in Chinese population by meta-analysis.
Search the relevant published papers and perform meta-analysis respectively on IL28B (rs12979860 and rs8099917) in Asian population and Chinese population under an additive genetic model by STATA11.0.
The pooled odds ratios (OR) of rs12979860 are 0.79 (95% CI, 0.53-1.18; P = 0.25, I2 = 63.2%) and 1.62 (95% CI, 1.04-2.51; P = 0.033, I2 = 54.3%) respectively in Asian population and Chinese population analysis. The pooled OR of rs8099917 are 1.05 (95% CI, 0.93-1.19; P = 0.44, I2 = 43.3%) and 0.97 (95% CI, 0.84-1.23; P = 0.726, I2 = 15.6%) respectively in Asian population and Chinese population analysis.
Our study demonstrated that T allele of rs12979680 can increase the risk of HBV infection in Chinese population but not Asian population under an additive genetic model. There is no association between rs8099917 and HBV infection in Chinese population and Asian population.
Meta-analysis; IL28B; rs12979680; rs8099917; HBV; Infection susceptibility
Simulation can be a very powerful tool to help decision making in many applications but exploring multiple courses of actions can be time consuming. Numerous ranking & selection (R&S) procedures have been developed to enhance the simulation efficiency of finding the best design. To further improve efficiency, one approach is to incorporate information from across the domain into a regression equation. However, the use of a regression metamodel also inherits some typical assumptions from most regression approaches, such as the assumption of an underlying quadratic function and the simulation noise is homogeneous across the domain of interest. To extend the limitation while retaining the efficiency benefit, we propose to partition the domain of interest such that in each partition the mean of the underlying function is approximately quadratic. Our new method provides approximately optimal rules for between and within partitions that determine the number of samples allocated to each design location. The goal is to maximize the probability of correctly selecting the best design. Numerical experiments demonstrate that our new approach can dramatically enhance efficiency over existing efficient R&S methods.
simulation; budget allocation; regression
Accumulated evidence indicates that the interconversion of iron between ferric (Fe3+) and ferrous (Fe2+) can be realized through interaction with reactive oxygen species in the Fenton and Haber–Weiss reactions and thereby physiologically effects redox cycling. The imbalance of iron and ROS may eventually cause tissue damage such as renal proximal tubule injury and necrosis. Many approaches were exploited to ameliorate the oxidative stress caused by the imbalance. (−)-Epigallocatechin-3-gallate, the most active and most abundant catechin in tea, was found to be involved in the protection of a spectrum of renal injuries caused by oxidative stress. Most of studies suggested that EGCG works as an antioxidant. In this paper, Multivariate analysis of the LC–MS data of tea extracts and binding assays showed that the tea polyphenol EGCG can form stable complex with iron through the protein Ngal, a biomarker of acute kidney injury. UV–Vis and Luminescence spectrum methods showed that Ngal can inhibit the chemical reactivity of iron and EGCG through forming an Ngal–EGCG–iron complex. In thinking of the interaction of iron and ROS, we proposed that EGCG may work as both antioxidant and Ngal binding siderphore in protection of kidney from injuries.
EGCG; Ngal; Siderophore; Antioxidant; Renal injury
The classic dynamic clamp technique uses a real-time electrical interface between living cells and neural simulations in order to investigate hypotheses about neural function and structure. One of the acknowledged drawbacks of that technique is the limited control of the cells' chemical microenvironment. In this manuscript, we use a novel combination of nanosensor and microfluidic technology and microfluidic and neural simulations to add sensing and control of chemical concentrations to the dynamic clamp technique. Specifically, we use a microfluidic lab-on-a-chip to generate distinct chemical concentration gradients (ions or neuromodulators), to register the concentrations with embedded nanosensors and use the processed signals as an input to simulations of a neural cell. The ultimate goal of this project is to close the loop and provide sensor signals to the microfluidic lab-on-a-chip to mimic the interaction of the simulated cell with other cells in its chemical environment.
carbon nanotube sensors; microfluidics; neural modeling; dynamic clamp
Mesenchymal chondrosarcoma(MCS) is a rare high-grade variant of chondrosarcoma. Consensus has not been reached on its optimal management. Resection with wide margins is usually recommended, but the effect of margins has been demonstrated by little positive evidence. Moreover, the effectiveness of adjuvant chemo- and/or radiotherapy remains controversial.
To describe the clinical characteristics and outcomes of MCS of bone and soft tissue, to assess the efficacies of surgery, chemotherapy and radiation, and finally to deliver a more appropriate therapy.
Materials and Methods
We reviewed EMBASE-, MEDLINE-, Cochrane-, Ovid- and PubMed-based to find out all cases of MCS of bone and soft tissue described between April 1994 and April 2014. Description of treatment and regular follow-up was required for each study. Language was restricted to English and Chinese. Issues of age, gender, location, metastasis, and treatment were all evaluated for each case. Kaplan-Meier Method and Cox Proportional Hazard Regression Model were used in the survival analysis.
From the 630 identified publications, 18 meeting the inclusion criteria were selected, involving a total of 107 patients. Based on these data, the 5-, 10-and 20-year overall survival are 55.0%, 43.5% and 15.7% respectively. The 5-, 10-, 20- year event-free survival rates are 45.0%, 27.2% and 8.1%, respectively. Treatment without surgery is associated with poorer overall survival and event-free survival. Negative surgical margins could significantly bring down the local-recurrence rate and are associated with a higher event-free survival rate. Chemotherapy regime based on anthracyclines does not benefit the overall survival. The addition of radiation therapy is not significantly associated with the overall or event-free survival. However, we recommend radiation as the salvage therapy for patients with positive margin so as to achieve better local control.
This review shows that surgery is essential in the management of MCS of bone and soft tissue. Appropriate adjuvant therapy may reduce local recurrence, but cannot benefit the overall survival.
We provide evidence of cortical neuronopathy in myelin oligodendrocyte glycoprotein-peptid-induced experimental autoimmune encephalomyelitis, an established model of chronic multiple sclerosis (MS). To investigate phenotypic perturbations in neurons in this model, we used apoptotic markers and immunohistochemistry with antibodies to NeuN and other surrogate markers known to be expressed by adult pyramidal layer V somas, including annexin V, encephalopsin and Emx1. We found no consistent evidence of chronic loss of layer V neurons but detected both reversible and chronic decreases in the expression of these markers in conjunction with evidence of cortical demyelination and pre-synaptic loss. These phenotypic perturbations were present in but not restricted to neocortical layer V. We also investigated inflammatory responses in the cortex and subcortical white matter of the corpus callosum (CC) and spinal dorsal funiculus and found that those in the cortex and CC were delayed compared to those in the spinal cord. Inflammatory infiltrates initially included T cells, neutrophils and Iba1-positive microglia/macrophages in the CC, whereas only Iba1-positive cells were present in the cortex. These data indicate that we have identified a new temporal pattern of subtle, phenotypic perturbations in neocortical neurons in this chronic MS model.
Corticospinal neurons; Motor strip; Multiple sclerosis; Neuronopathy
Monolithically integrated emitters have been increasingly applied to microfluidic devices that are coupled to mass spectrometers (MS) as electrospray ionization sources (ESI). A new method was developed to fabricate a duplicable structure which integrated the emitter into a poly(dimethylsiloxane) chip corner. Two photoresist layers containing a raised base which guaranteed the precise integration of the electrospray tip emitter and ensured that the cutting out of the tip exerted no influence even during repeated prototyping were used to ease the operation of the process. Highly stable ESI-MS performance was obtained and the results were compared with those of a commercial fused-silica capillary source. Furthermore, chip-to-chip and run-to-run results indicated both reliability and reproducibility during repeated fabrication. These results reveal that the proposed chip can provide an ideal ion source for MS across many applications, especially with the perspective to be widely used in portable MS during on-site analysis.
microfluidic chip; multi-layer soft lithography; electrospray ionization
High rate of viral replication and lacking of proofreading activity in hepatitis B virus (HBV) polymerase lead to the generation of mutations in HBV virus. Mutations in the reverse transcriptase (RT) region of HBV polymerase are demonstrated to be strongly associated with drug resistance during antiviral treatment. However, the presence of mutations as well as its clinical significance in treatment-naïve hepatitis patients (defined as pre-existing mutations) need to be further investigated. In the present study, a total of 168 serum samples from treatment-naive chronic hepatitis B (CHB) patients were collected, and the RT region of HBV polymerase was sequenced. The results showed that pre-existing mutations in the RT region of HBV polymerase were detected in 43 of 168 (25.6%) treatment-naive CHB patients within which there were no well-characterized primary nucleotide analogs (NAs) resistance sites. Three dominant sites at rt191, rt207 and rt226 were found mutant in 7(16.28%), 8(18.60%), and 14(32.56%) samples respectively among these 43 patients. No significant correlation was found between pre-existing mutations and gender, age, HBV genotype, ALT, HBeAg or HBV DNA loads. However, patients with pre-existing RT mutations under HBeAg sero-negative status exhibited decreased HBV DNA loads, which contributed to the decreased HBV DNA loads in the total HBeAg sero-negative patients. The above investigation indicated that there was a prevalence of pre-existing mutations in RT region of HBV polymerase which might affect the serum HBV DNA level in treatment-naive CHB patients. Its effects on the occurrence of NAs resistance and the prognosis after treatment need to be further investigated.
Cancer stem-like cell (CS-like cell) is considered to be responsible for recurrence and drug resistance events in breast cancer, which makes it a potential target for novel cancer therapeutic strategy. The FDA approved flubendazole, has been widely used in the treatment of intestinal parasites. Here, we demonstrated a novel effect of flubendazole on breast CS-like cells. Flubendazole inhibited breast cancer cells proliferation in dose- and time-dependent manner and delayed tumor growth in xenograft models by intraperitoneal injection. Importantly, flubendazole reduced CD44high/CD24low subpopulation and suppressed the formation of mammosphere and the expression of self-renewal related genes including c-myc, oct4, sox2, nanog and cyclinD1. Moreover, we found that flubendazole induced cell differentiation and inhibited cell migration. Consistently, flubendazole reduced mesenchymal markers (β-catenin, N-cadherin and Vimentin) expression and induced epithelial and differentiation marker (Keratin 18) expression in breast cancer cells. Mechanism study revealed that flubendazole arrested cell cycle at G2/M phase and induced monopolar spindle formation through inhibiting tubulin polymerization. Furthermore, flubendazole enhanced cytotoxic activity of conventional therapeutic drugs fluorouracil and doxorubicin against breast cancer cells. In conclusion, our findings uncovered a remarkable effect of flubendazole on suppressing breast CS-like cells, indicating a novel utilization of flubendazole in breast cancer therapy.
flubendazole; breast cancer; cancer stem-like cell; cell cycle; tubulin
Bacterial small non-coding RNAs (sRNAs) are gene expression modulators respond to environmental changes, stressful conditions, and pathogenesis. In this study, by using a combined bioinformatic and experimental approach, eight novel sRNA genes were identified in intracellular pathogen Brucella melitensis. BSR0602, one sRNA that was highly induced in stationary phase, was further examined and found to modulate the intracellular survival of B. melitensis. BSR0602 was present at very high levels in vitro under stresses similar to those encountered during infection in host macrophages. Furthermore, BSR0602 was found to be highly expressed in the spleens of infected mice, suggesting its potential role in the control of pathogenesis. BSR0602 targets the mRNAs coding for gntR, a global transcriptional regulator, which is required for B. melitensis virulence. Overexpression of BSR0602 results in distinct reduction in the gntR mRNA level. B. melitensis with high level of BSR0602 is defective in bacteria intracellular survival in macrophages and defective in growth in the spleens of infected mice. Therefore, BSR0602 may directly inhibit the expression of gntR, which then impairs Brucellae intracellular survival and contributes to Brucella infection. Our findings suggest that BSR0602 is responsible for bacterial adaptation to stress conditions and thus modulate B. melitensis intracellular survival.
Brucella; small RNA; intracellular survival; post-transcriptional control; stress response; virulence
AIM: To investigate a new modification of pancreaticoduodenectomy (PD)-a mesh-like running suturing of the pancreatic remnant and Braun’s enteroenterostomy.
METHODS: Two hundred and three patients underwent PD from 2009 to 2014 and were classified into two groups: Group A (98 patients), who received PD with a mesh-like running suturing for the pancreatic remnant, and Braun’s enteroenterostomy; and Group B (105 patients), who received standard PD. Demographic data, intraoperative findings, postoperative morbidity and perioperative mortality between the two groups were compared by univariate and multivariate analysis.
RESULTS: Demographic characteristics between Group A and Group B were comparable. There were no significant differences between the two groups concerning perioperative mortality, and operative blood loss, as well as the incidence of the postoperative morbidity, including reoperation, bile leakage, intra-abdominal fluid collection or infection, and postoperative bleeding. Clinically relevant postoperative pancreatic fistula (POPF) and delayed gastric emptying (DGE) were identified more frequently in Group B than in Group A. Technique A (PD with a mesh-like running suturing of the pancreatic remnant and Braun’s enteroenterostomy) was independently associated with decreased clinically relevant POPF and DGE, with an odds ratio of 0.266 (95%CI: 0.109-0.654, P = 0.004) for clinically relevant POPF and 0.073 (95%CI: 0.010-0.578, P = 0.013) for clinically relevant DGE.
CONCLUSION: An additional mesh-like running suturing of the pancreatic remnant and Braun’s enteroenterostomy during PD decreases the incidence of postoperative complications and is beneficial for patients.
Pancreaticoduodenectomy; Delayed gastric emptying; Braun’s enteroenterostomy; Running suture; Postoperative pancreatic fistula
1,25-Dihydroxyvitamin D3 (1,25-(OH)2D3) has an anti-inflammatory effect on human monocytes incubated with sera from patients with type 2 diabetes/diabetic nephropathy; however, the detailed mechanism behind the effect remains to be explored. The current study further validated the effects of 1,25-(OH)2D3 and lipopolysaccharide (LPS) + human recombinant interleukin (IL)-15 on the expression of the vitamin D receptor (VDR) and phosphorylated signal transducer and activator of transcription 5 (p-STAT5) in human monocytes and explored the possible interaction between VDR and p-STAT5. Synchronized THP-1 cells were divided into pre-intervened groups, namely the control, LPS + IL-15 and 1,25-(OH)2D3, groups, according to their differing treatments. The expression of STAT5 and p-STAT5 was evaluated by western blot analysis; the concentration of IL-6 in the supernatant was determined using an enzyme-linked immunosorbent assay; the expression of cytoskeletal proteins was observed using immunofluorescence and laser confocal microscopy; and the possible intranuclear interaction between VDR and p-STAT5 was investigated using immunofluorescence, immuno-coprecipitation and western blot analysis. LPS + IL-15 upregulated p-STAT5 expression and the IL-6 level (P<0.05), with cytoskeletal rearrangement. These effects were partially prevented through pretreatment with 1,25-(OH)2D3. The LPS + IL-15 group and the 1,25-(OH)2D3 group exhibited an interaction between p-STAT5 and VDR in the nucleus, with the latter group showing a significant increase compared with the former (P<0.05). The immuno-coprecipitation results provided evidence of the interaction between VDR and p-STAT5, which suggests the existence of STAT5-VDR crosstalk in THP-1 monocytes. Cytoskeletal rearrangement, VDR and p-STAT5 potentially have interactions in THP-1 monocytes. The anti-inflammatory effect of 1,25-(OH)2D3 may be associated with crosstalk between STAT5 and VDR, which further induces cytoskeletal rearrangement.
1,25-dihydroxyvitamin D3; monocyte; lipopolysaccharide; interleukin-15; vitamin D receptor; signal transducer and transcription activator
Differentiation induction is currently considered as an alternative strategy for treating chronic myelogenous leukemia (CML). Our previous work has demonstrated that Sprouty-related EVH1 domainprotein2 (Spred2) was involved in imatinib mediated cytotoxicity in CML cells. However, its roles in growth and lineage differentiation of CML cells remain unknown. In this study, we found that CML CD34+ cells expressed lower level of Spred2 compared with normal hematopoietic progenitor cells, and adenovirus mediated restoration of Spred2 promoted the erythroid differentiation of CML cells. Imatinib could induce Spred2 expression and enhance erythroid differentiation in K562 cells. However, the imatinib induced erythroid differentiation could be blocked by Spred2 silence using lentiviral vector PLKO.1-shSpred2. Spred2 interference activated phosphorylated-ERK (p-ERK) and inhibited erythroid differentiation, while ERK inhibitor, PD98059, could restore the erythroid differentiation, suggesting Spred2 regulated the erythroid differentiation partly through ERK signaling. Furthermore, Spred2 interference partly restored p-ERK level leading to inhibition of erythroid differentiation in imatinib treated K562 cells. In conclusion, Spred2 was involved in erythroid differentiation of CML cells and participated in imatinib induced erythroid differentiation partly through ERK signaling.
Surfactant protein D (SP-D), a pattern recognition molecule, has been shown to play roles in host defense such as opsonisation, aggregation of pathogens, and modulation of the inflammatory response. In light of infection-induced exacerbations and damage to the airway epithelium from inflammation, these functions of SP-D make it relevant in the development and pathogenesis of asthma.
Expression of SP-D was examined in human airway sections and primary airway epithelial cells (AEC) grown in air-liquid interface (ALI) cultures and comparisons were made between those from asthmatic and non-asthmatic donors. ALI cultures of AEC from non-asthmatic donors were examined for SP-D, Mucin 5AC, and cytokeratin-5 expression at different stages of differentiation. Interleukin-13 (IL-13) treatment of airway epithelium and its effect on SP-D expression was studied using ALI and monolayer cultures of primary AEC from non-asthmatic and asthmatic donors.
Airway epithelium of asthmatics, compared to that of non-asthmatics, expressed increased levels of SP-D as demonstrated in airway tissue sections (fraction of epithelium 0.66 ± 0.026 vs. 0.50 ± 0.043, p = 0.004) and ALI cultures (fraction of epithelium 0.50 ± 0.08 vs. 0.25 ± 0.07). SP-D expression decreased as ALI cultures differentiated from 7 days to 21 days (fraction of epithelium 0.62 ± 0.04 to 0.23 ± 0.03, p = 0.004). Treatment with IL-13 decreased SP-D expression in both ALI cultures (fraction of epithelium 0.21 ± 0.06 vs. 0.62 ± 0.04, p = 0.0005) and monolayer cultures (protein expression fold change 0.62 ± 0.05) of non-asthmatic AEC; however, IL-13 had no significant effect on SP-D expression in monolayer cultures of asthmatic AEC. Experiments with non-asthmatic monolayer cultures indicate IL-13 exert its effect on SP-D through the IL-13 receptor alpha1 and transcription factor STAT6.
SP-D is expressed differently in airways of asthmatics relative to that of non-asthmatics. This can have implications on the increased susceptibility to infections and altered inflammatory response in asthmatic patients. Future functional studies on the role of SP-D in asthma can provide better insight into defects in the structure and regulation of SP-D.
Electronic supplementary material
The online version of this article (doi:10.1186/s12931-015-0177-7) contains supplementary material, which is available to authorized users.
Surfactant protein D; Asthma; Airway epithelium; Air-liquid-interface; Interleukin-13
Motoneuron death after transection of the axons (axotomy) in neonates is believed to share the same mechanistic bases as naturally occurring programmed cell death during development. The c-Jun N-terminal kinase pathway is activated in both forms of motoneuron death, but it remains unknown to what extent these two forms of motoneuron death depend on this pathway and which upstream kinases are involved. We found that numbers of facial motoneurons are doubled in neonatal mice deficient in either ZPK/DLK (zipper protein kinase, also known as dual leucine zipper kinase), a mitogen-activated protein kinase kinase kinase, or in MKK4/MAP2K4, a mitogen-activated protein kinase kinase directly downstream of ZPK/DLK, and that the facial motoneurons in those mutant mice are completely resistant to axotomy-induced death. Conditional deletion of MKK4/MAP2K4 in neurons further suggested that ZPK/DLK and MKK4/MAP2K4-dependent mechanisms underlying axotomy-induced death are motoneuron autonomous. Nevertheless, quantitative analysis of facial motoneurons during embryogenesis revealed that both ZPK/DLK and MKK4/MAP2K4-dependent and -independent mechanisms contribute to developmental elimination of excess motoneurons. In contrast to MKK4/MAP2K4, mice lacking MKK7/MAP2K7, another mitogen-activated protein kinase kinase directly downstream of ZPK/DLK, conditionally in neurons did not have excess facial motoneurons. However, some MKK7/MAP2K7-deficient facial motoneurons were resistant to axotomy-induced death, indicating a synergistic effect of MKK7/MAP2K7 on axotomy-induced death of these facial motoneurons. Together, our study provides compelling evidence for the pivotal roles of the ZPK/DLK and MKK4/MAP2K4-dependent mechanism in axotomy-induced motoneuron death in neonates and also demonstrates that axotomy-induced motoneuron death is not identical to developmental motoneuron death with respect to the involvement of ZPK/DLK, MKK4/MAP2K4 and MKK7/MAP2K7.
injury response; mitogen-activated protein kinase; programmed cell death