Deregulation of Type I IFN-Dependent Genes Correlates with Increased Susceptibility to Cytomegalovirus Acute Infection of Dicer Mutant Mice

Regulation of gene expression by microRNAs (miRNAs) is now considered as an essential mechanism for cell development and homeostasis. Indeed, numerous studies have reported that modulating their expression, maturation, or activity can affect cell survival, identity or activation. In particular, miRNAs are key players in the tight regulation of signaling cascades, and as such, they appear as perfectly suited immunomodulators. Several immune-related processes, including inflammation, have recently been demonstrated to require specific miRNAs. In addition, the discovery of herpesvirus-encoded miRNAs has reinforced this assumption. To decipher the potential roles of miRNAs in innate antiviral immune response, we developed an in vivo model based on the inoculation of mouse cytomegalovirus (MCMV) in mice. Furthermore, we exploited a mouse line carrying a hypomorphic mutation in the Dicer gene to visualize the impact of impaired miRNA biogenesis upon the anti-MCMV response. Our data indicate that miRNAs are important actors in mounting an efficient response against herpesviruses. We suggest that a rapid and transient interferon response following viral infection requires miRNA-dependent repressor release. In addition, our in vivo efforts identified several miRNA targets, thus providing a conceptual framework for future analyzes on the regulation of specific actors involved in the Type I interferon pathway.     

Diazepam-Loaded Solid Lipid Nanoparticles: Design and Characterization

The aim of the present study was to investigate the feasibility of the inclusion of a water-insoluble drug (diazepam, DZ) into solid lipid nanoparticles (SLNs), which offer combined advantages of rapid onset and prolonged release of the drug. This work also describes a new approach to prepare suppositories containing DZ-loaded SLN dispersions, as potential drug carrier for the rectal route. Modified high-shear homogenization and ultrasound techniques were employed to prepare SLNs. The effect of incorporation of different concentrations of Compritol® ATO 888 or Imwitor® 900K and Poloxamer 188 or Tween 80 was investigated. Results showed that varying the type or concentration of lipid matrix or surfactant had a noticeable influence on the entrapment efficiencies, particle size, and release profiles of prepared SLNs. Differential scanning calorimetry and X-ray diffraction measurements showed that the majority of SLNs possessed less ordered arrangements of crystals than the corresponding bulk lipids, which was favorable for increasing the drug loading capacity. Transmission electron microscopy and laser diffractometry studies revealed that the prepared nanoparticles were round and homogeneous and 60% of the formulations were less than 500 nm. Additionally, SLN formulations showed significant (P?in vitro release of DZ from the suppositories prepared using DZ-loaded SLN dispersions (equivalent to 2 mg DZ) was significantly (P?相似文献   

Listing all sorting reversals in quadratic time

We describe an average-case O(n ²) algorithm to list all reversals on a signed permutation π that, when applied to π, produce a permutation that is closer to the identity. This algorithm is optimal in the sense that, the time it takes to write the list is Ω(n ²) in the worst case.     

Latrunculin and cytochalasin decrease chondrocyte matrix retention.

The proteoglycan-rich extracellular matrix (ECM) directly associated with the cells of articular cartilage is anchored to the chondrocyte plasma membrane via interaction with the hyaluronan receptor CD44. The cytoplasmic tail of CD44 interacts with the cortical cytoskeleton. The objective of this study was to determine the role of the actin cytoskeleton in CD44-mediated matrix assembly by chondrocytes and cartilage matrix retention and homeostasis. Adult bovine articular cartilage tissue slices and isolated chondrocytes were treated with latrunculin or cytochalasin. Tissues were processed for histology and chondrocytes were examined for CD44 expression and pericellular matrix assembly. Treatments that disrupt the actin cytoskeleton reduced chondrocyte pericellular matrix assembly and the retention of proteoglycan within cartilage explants. There was enhanced detection of a neoepitope resulting from proteolysis of aggrecan. Cytoskeletal disruption did not reduce CD44 expression, as monitored by flow cytometry, but detergent extraction of CD44 was enhanced and hyaluronan binding was decreased. Thus, disruption of the cytoskeleton reduces the anchorage of CD44 in the chondrocyte membrane and the capacity of CD44 to bind its ligand. The results suggest that cytoskeletal disruption within cartilage uncouples chondrocytes from the matrix, resulting in altered metabolism and deleterious changes in matrix structure.     

Vancomycin heteroresistance in coagulase negative <Emphasis Type="Italic">Staphylococcus</Emphasis> blood stream infections from patients of intensive care units in Mansoura University Hospitals,Egypt

Background

Vancomycin heteroresistance in coagulase negative Staphylococci (CoNS) is a recent health concern especially in serious infections like bloodstream infections as it may lead to failure of therapy. Little information is available about the prevalence vancomycin heteroresistance in CoNS causing bloodstream infections in intensive care units (ICUs) patients of Mansoura University Hospitals (MUHs).

Methods

This prospective study enrolled 743 blood samples collected from ICUs patients presented with clinical manifestations of bloodstream infections over the period extending from January 2014 to March 2016. Samples were processed, coagulase negative Staphylococci were identified by routine microbiological methods and the absence of coagulase activity. Species were identified by API Staph 32. Oxacillin resistant CoNS were identified by cefoxitin disc diffusion method. Susceptibility testing of isolated CoNS to vancomycin was carried out using vancomycin agar dilution method. Mec A gene detection by PCR was done for oxacillin resistant isolates. Screening for vancomycin heteroresistance was done on brain heart infusion (BHI) agar containing 4 μg/mL vancomycin. Confirmation of vancomycin heteroresistance was carried out by population analysis profile (PAP).

Results

A total of 58 isolates were identified as CoNS from patients of clinically suspected bloodstream infections. The identified species were 33 (56.9%) Staphylococcus epidermidis, 12 (20.7%) Staphylococcus capitis, 7 (12.1%) Staphylococcus haemolyticus, and 3 isolates (5.2%) Staphylococcus lugdunesis. Three isolates were unidentified by API Staph 32. Forty-four (75.9%) isolates were oxacillin resistant. Mec A gene was detected in all oxacillin resistant isolates. All isolates had susceptible vancomycin MICs by agar dilution. Nine isolates (15.5%) could grow on BHI agar containing 4 μg/mL vancomycin. These isolates showed heterogeneous profile of resistance to vancomycin by population analysis profile.

Conclusions

Vancomycin heteroresistant CoNS causing bloodstream infections is growing unrecognized health hazard in ICUs patients. These isolates have susceptible vancomycin MICs. Screening methods are recommended and should be considered to improve clinical outcome in these high risk patients.

     

Circulating endothelium-enriched microRNA-126 as a potential biomarker for coronary artery disease in type 2 diabetes mellitus patients

Circulating microRNAs (miRNAs) have been shown as promising biomarkers for various diseases. We investigated the predictive potential of circulating endothelium-enriched miR-126 in type 2 diabetes patients (T2D) without chronic complications and T2D patients with coronary artery diseases (CAD). The expression levels of circulating miR-126, determined by quantitative real time PCR, were decrease in peripheral blood of T2D patients and T2D with CAD compared with healthy controls. MiR-126 strongly associated with T2D and CAD, negatively correlated with LDL in CAD patients and differentiated between T2D patients, T2D patients with CAD and healthy subjects. Circulating miR-126 may serve as a biomarker for predicting patients with T2D and diabetic CAD.     

Chloroplast DNA analysis in Tunisian fig cultivars (Ficus carica L.): Sequence variations of the trnL-trnF intergenic spacer

We investigated the nucleotide variation of a non-coding, chloroplast DNA (cpDNA) region to infer relationships among Tunisian fig cultivars. In this study, we examine the level of genetic diversity and its distribution using sequences of the trnL and trnF genes intergenic spacer. The non-coding region displays 28 substitution sites. Insertions and deletions involving 6 sites were found. By using the Kimura-2 method, nucleotide sequences have been aligned using the MEGA program to calculate pairwise divergence of trnL-trnF spacer sequences between cultivars. The size of this non-coding region varied from 430 to 464 bases. The relatively high A + T values (63.7–64.4%) of trnL-trnF intergenic spacer in Ficus carica may explain the high proportion of the identified transversions (t_i/t_v = 0.9). These results suggest the occurrence of nucleotide diversity with a large variation level of chloroplast non-coding region. The analysed data illustrate a considerable level of variability in the genetic pool of the local germplasm. In fact, relationships inferred from the cpDNA analysis suggest several clades, which do not show geographical correspondence. Fourteen haplotypes were detected among 20 individuals examined, yielding a haplotype diversity of 0.983 and a high level of nucleotide diversity (0.0100). The observed variation pattern of plastid DNA provides evidence that the fig germplasm has been undergoing rapid expansion. Neutrality tests rejected the neutrality assumption in the total sample. The cytoplasm variability indicates a narrow genetic base in the cultivated common fig. Despite the high level value of the apparent diversity, we may conclude that fig chloroplast genome provides a new conceptual and practical opportunity to evaluate genetic diversity and to identify local cultivars, making it a valuable source to include into potential breeding programs.     

Rapid Detection of Oculopathogenic Adenovirus in Conjunctivitis

Ocular adenovirus (Ad) infections occur throughout the world in both sporadic and epidemic forms. Accurate laboratory diagnosis of Ad in conjunctival samples is always valuable. The present study was carried out to explore the presence of Ad as a causative agent in clinically suspected viral conjunctivitis and to compare the performance of conventional virus isolation on cell cultures, direct detection of Ad antigens in conjunctival cells by a direct fluorescence assay, Ad DNA detection by polymerase chain reaction (PCR), and specific IgM measurement by ELISA. Samples included scrapes from conjunctiva. Scrapes were subjected to study by direct immunofluorescence stain, culture on the Hep-2 cell line, and PCR for Ad detection. Blood samples were also taken and subjected to study for specific anti-Ad IgM determination. The culture for Ad was positive in 77.8%, direct antigen detection by fluorescent stain was positive in 72.2%, PCR was positive in 83.3%, and serology was positive in 88.9% of patients. Both determination of antibody IgM and PCR correctly identified a larger group of patients compared to cell culture. The most sensitive and specific method for diagnosis of Ad compared to culture was PCR (100%), followed by IgM detection (92.9%) then direct antigen detection by fluorescent stain (85.8%). From this study, we conclude that Ad is a common pathogen in sporadic cases of conjunctivitis. Screening of adenoviral conjunctivitis is possible by using specific IgM due to its high sensitivity. A confirmatory test can be done by PCR for diagnosis of Ad, as it is a rapid, specific, and accurate method.     

Effects of sirolimus on plasma lipids,lipoprotein levels,and fatty acid metabolism in renal transplant patients

Sirolimus (Rapammune, rapamycin, RAPA) is a potent immunosuppressive drug that reduces renal transplant rejection. Hyperlipidemia is a significant side effect of sirolimus treatment, and frequently leads to cardiovascular disease. This study was undertaken to determine the repeatability, reversibility, and dose dependence of the plasma lipid and apolipoprotein altering effects of sirolimus, and to elucidate the mechanism by which sirolimus induces hypertriglyceridemia in some renal transplant patients. Six patients with renal allografts maintained on cyclosporine A and prednisone were selected on the basis of their previous hyperlipidemic response to short term (14 days) sirolimus administration. For longer-term treatment, each patient was started on 10 mg/day sirolimus and continued as tolerated for 42 days to reinduce hyperlipidemia. Timed blood samples were analyzed for lipid, apolipoprotein, and sirolimus levels. During sirolimus administration, mean total plasma cholesterol increased from 214 mg/dl to 322 mg/dl (+50%; range 25-92%); LDL-cholesterol levels followed a similar pattern. Mean triglyceride level rose from 227 to 432 mg/dl (+95%; range 9-254%). ApoB-100 concentration rose from 124 to 160 mg/dl (+28%; P < 0.05). ApoC-III level increased from 28.9 to 55.5 mg/dl, +92%; (P < 0.013). These lipid and apolipoprotein changes were found to be repeatable, reversible, and dose dependent. [(13)C(4)]palmitate metabolic studies in four patients with hypertriglyceridemia indicated that the free fatty acid pool was expanded by sirolimus treatment (mean = 42.3%). Incorporation of [(13)C(4)]palmitate into triglycerides of VLDL, IDL, and LDL was decreased 38.3%, 42,1%, and 38.4%, respectively, by sirolimus treatment of these patients. These results suggest that sirolimus alters the insulin signaling pathway so as to increase adipose tissue lipase activity and/or decrease lipoprotein lipase activity, resulting in increased hepatic synthesis of triglyceride, increased secretion of VLDL, and increased hypertriglyceridemia.     

Expression of urotensin-II in human coronary atherosclerosis

The vasoactive peptide urotensin-II (U-II) is best known for its ability to regulate peripheral vascular and cardiac contractile function in vivo, and recent in vitro studies have suggested a role for the peptide in the control of vascular remodeling by inducing smooth muscle proliferation and fibroblast-mediated collagen deposition. Therefore, U-II may play a role in the etiology of atherosclerosis. In the present study we sought to determine the expression of U-II in coronary arteries from patients with coronary atherosclerosis and from normal control subjects, using immunohistochemistry and in situ hybridization. In normal coronary arteries, there was little expression of U-II in all types of cells. In contrast, in patients with coronary atherosclerosis, endothelial expression of U-II was significantly increased in all diseased segments (P < 0.05). Greater expression of U-II was noted in endothelial cells of lesions with subendothelial inflammation or fibrofatty lesion compared with that of endothelial cells underlined by dense fibrosis or minimal intimal thickening. Myointimal cells and foam cells also expressed U-II. In most diseased segments, medial smooth muscle cells exhibited moderate expression of U-II. These findings demonstrate upregulation of U-II in endothelial, myointimal and medial smooth muscle cells of atherosclerotic human coronary arteries, and suggest a possible role for U-II in the pathogenesis of coronary atherosclerosis.