Correction: Structural and Functional Analysis of the Symmetrical Type I Restriction Endonuclease R.EcoR124INT.

[This corrects the article DOI: 10.1371/journal.pone.0035263.].

A new formulation of fluticasone propionate/salmeterol in a metered-dose inhaler (MDI HFA) allows for the reduction of a daily dose of corticosteroid and provides optimal asthma control - A randomized, multi-center, non-inferiority, phase IV clinical study.

BACKGROUND: Improvement of the delivery method of inhaled corticosteroids and subsequent dose reduction can minimize the risk of unfavorable outcomes while providing optimal asthma control. OBJECTIVE: This randomized, multi-center, non-inferiority, phase IV clinical study compared the efficacy and safety of a new formulation of fluticasone propionate/salmeterol (250 µg/50 µg, twice daily) administered in a metered-dose inhaler hydrofluoroalkane (MDI HFA) with a dry-powder inhaler (DPI) containing fluticasone propionate/salmeterol (500 µg/50 µg, twice daily). METHODS: Adults with asthma (n = 231) were randomly assigned to either the study group (treated for 12 weeks with fluticasone propionate/salmeterol MDI HFA) or a control group (treated for 12 weeks with fluticasone propionate/salmeterol DPI). Asthma symptoms, exacerbations, short-acting ß2-agonist (SABA) use, physical activity, lung function, and general health status were assessed during four study visits. RESULTS: Compared with the reference drug, the study drug decreased the incidence of daytime and night-time asthma symptoms, asthma exacerbations, self-administration of SABA, and the limitation of physical activity. Comparable improvement in peak expiratory flow ([MDI HFA] from 6.2 ± 0.2 to 6.6 ± 0.2 l/s vs. [DPI] from 6.0 ± 0.2 to 6.9 ± 0.2 l/s; p > 0.05), forced expiratory volume in one second, and forced vital capacity were obtained in both groups. Significantly lower incidence of hoarseness was observed in the study group ([MDI HFA] 0.0% vs. [DPI] 2.8%; p = 0.0267); no major differences were found for other adverse events. CONCLUSIONS: Fluticasone propionate/salmeterol (250 µg/50 µg, twice daily) MDI HFA provides optimal asthma control and is non-inferior to fluticasone propionate/salmeterol (500 µg/50 µg, twice daily) DPI.

Correction: Structural and Functional Analysis of the Symmetrical Type I Restriction Endonuclease R.EcoR124I(NT).

[This corrects the article DOI: 10.1371/journal.pone.0035263.].

Clinical Course and Outcome of Community-Acquired Bacterial Meningitis in Cancer Patients.

The aim of the study was to determine the course and outcome of bacterial meningitis (BM) in patients with cancer. We retrospectively reviewed files of patients with community-acquired BM, hospitalized in a single neuroinfection center between January 2010 and December 2017. There were 209 patients included in the analysis: 28 had cancer (9 women, 19 men; median age 76, IQR 67-80 years) and 181 were cancer-free (76 women, 105 men; median age 52, IQR 33-65 years) and constituted the control group. Cancer patients, compared with controls, were more likely to present with seizures (25% vs. 8%, p = 0.019), scored higher on the Sequential Organ Failure Assessment, and had a higher mortality rate (32% vs. 13%, p = 0.025). Further, cancer patients were less likely (64% vs. 83%, p = 0.033) to present with two or more out of four clinical manifestations of BM (pyrexia, neck stiffness, altered mental status, and headache) and had a lower white blood cell (WBC) count than non-cancer controls. In multiple regression analysis, the presence of bacterial meningitis in cancer patients was independently associated only with older age (p = 0.001) and lower WBC count (p = 0.007), while mortality was associated with lower Glasgow Coma Score (p = 0.003). In conclusion, bacterial meningitis in cancer patients is characterized by atypical symptoms and high mortality, which requires physicians' vigilance and a prompt investigation of cerebrospinal fluid in suspected cases. However, multiple regression analysis suggests that differences in clinical presentation and outcomes of bacterial meningitis between cancer and cancer-free patients may also be attributable to other factors, such as age differences.

Duplicated inferior vena cava with coexisting multiple vascular anomalies and their clinical implications: a case report.

The paper presents the case of a 23-year-old man with multiple venous anomalies. The abnormalities were asymptomatic, and they were detected accidentally on routine abdominal ultrasound examination. The anomalies were found in the inferior vena cava, right testicular vein, left renal vein, and hepatic veins. Familiarity with different developmental variants within the inferior vena cava and other venous vessels plays a crucial role in ultrasound imaging. Vascular anomalies, although rare, should be taken into account in the differential diagnosis of focal lesions within the abdominal cavity. Also, variation in vascular anatomy may be a precipitating factor for blood flow disorders, and hence predispose patients to deep vein thrombosis and other pathological conditions. The reported case serves as a valuable addition to the knowledge of the vascular system that radiologists use in their everyday practice when performing diagnostic ultrasound examinations.

Chronic alcohol abuse affects the clinical course and outcome of community-acquired bacterial meningitis.

The aim of the study was to determine the effect of chronic alcohol abuse on the course and outcome of bacterial meningitis (BM). We analyzed records of patients with BM who were hospitalized between January 2010 and December 2017 in the largest neuroinfection center in Poland. Out of 340 analyzed patients, 45 (13.2%) were alcoholics. Compared with non-alcoholics, alcoholics were more likely to present with seizures (p < 0.001), scored higher on the Sequential Organ Failure Assessment (SOFA) (p = 0.002) and lower on the Glasgow Coma Scale (GCS) (p < 0.001), and had worse outcome as measured by the Glasgow Outcome Score (GOS) (p < 0.001). Furthermore, alcoholics were less likely to complain of headache (p < 0.001) and nausea/vomiting (p = 0.005) and had lower concentration of glucose in cerebrospinal fluid (CSF) (p = 0.025). In the multiple logistic regression analysis, alcoholism was associated with lower GCS (p = 0.036), presence of seizures (p = 0.041), male gender (p = 0.042), and absence of nausea/vomiting (p = 0.040). Furthermore, alcoholism (p = 0.031), lower GCS score (p = 0.001), and higher blood urea concentration (p = 0.018) were independently associated with worse outcome measured by GOS. Compared with non-alcoholics, chronic alcohol abusers are more likely to present with seizures, altered mental status, and higher SOFA score and have an increased risk of unfavorable outcome. In multivariate analysis, seizures and low GCS were independently associated with alcoholism, while alcoholism was independently associated with worse outcome.

Mutation of praR in Rhizobium leguminosarum enhances root biofilms, improving nodulation competitiveness by increased expression of attachment proteins.

In Rhizobium leguminosarum bv. viciae, quorum-sensing is regulated by CinR, which induces the cinIS operon. CinI synthesizes an AHL, whereas CinS inactivates PraR, a repressor. Mutation of praR enhanced biofilms in vitro. We developed a light (lux)-dependent assay of rhizobial attachment to roots and demonstrated that mutation of praR increased biofilms on pea roots. The praR mutant out-competed wild-type for infection of pea nodules in mixed inoculations. Analysis of gene expression by microarrays and promoter fusions revealed that PraR represses its own transcription and mutation of praR increased expression of several genes including those encoding secreted proteins (the adhesins RapA2, RapB and RapC, two cadherins and the glycanase PlyB), the polysaccharide regulator RosR, and another protein similar to PraR. PraR bound to the promoters of several of these genes indicating direct repression. Mutations in rapA2, rapB, rapC, plyB, the cadherins or rosR did not affect the enhanced root attachment or nodule competitiveness of the praR mutant. However combinations of mutations in rapA, rapB and rapC abolished the enhanced attachment and nodule competitiveness. We conclude that relief of PraR-mediated repression determines a lifestyle switch allowing the expression of genes that are important for biofilm formation on roots and the subsequent initiation of infection of legume roots.

A rapid purification procedure for the HsdM protein of EcoR124I and biophysical characterization of the purified protein.

Type I restriction-modification (R-M) systems are comprised of two multi-subunit enzymes with complementary functions: the methyltransferase (~160 kDa), responsible for methylation of DNA, and the restriction endonuclease (~400 kDa), responsible for DNA cleavage. Both enzymes share a number of subunits, including HsdM. Characterisation of either enzyme first requires the expression and purification of its constituent subunits, before reconstitution of the multisubunit complex. Previously, purification of the HsdM protein had proved problematic, due to the length of time required for the purification and its susceptibility to degradation. A new protocol was therefore developed to decrease the length of time required to purify the HsdM protein and thus prevent degradation. Finally, we show that the HsdM subunit exhibits a concentration dependent monomer-dimer equilibrium.

Antiproliferative activity and synthesis of 8-prenylnaringenin derivatives by demethylation of 7-O- and 4'-O-substituted isoxanthohumols.

Several analogues of 7-O- and 4'-O-substituted isoxanthohumol and 8-prenylnaringenin, the strongest known phytoestrogen and potential anticancerogenic agent, were synthesized. Acyl, alkyl, and allyl derivatives of isoxanthohumol underwent the demethylation process using MgI(2 )× 2Et(2)O in anhydrous THF with the yields of 61-89%. Some of the compounds approached the international criteria of antiproliferative activity (4 µg/ml) for synthetic agents against the human cancer cell lines.

Structural and functional analysis of the symmetrical Type I restriction endonuclease R.EcoR124I(NT).

Type I restriction-modification (RM) systems are comprised of two multi-subunit enzymes, the methyltransferase (∼160 kDa), responsible for methylation of DNA, and the restriction endonuclease (∼400 kDa), responsible for DNA cleavage. Both enzymes share a number of subunits. An engineered RM system, EcoR124I(NT), based on the N-terminal domain of the specificity subunit of EcoR124I was constructed that recognises the symmetrical sequence GAAN(7)TTC and is active as a methyltransferase. Here, we investigate the restriction endonuclease activity of R. EcoR124I(NT)in vitro and the subunit assembly of the multi-subunit enzyme. Finally, using small-angle neutron scattering and selective deuteration, we present a low-resolution structural model of the endonuclease and locate the motor subunits within the multi-subunit enzyme. We show that the covalent linkage between the two target recognition domains of the specificity subunit is not required for subunit assembly or enzyme activity, and discuss the implications for the evolution of Type I enzymes.

Structure and operation of the DNA-translocating type I DNA restriction enzymes.

Type I DNA restriction/modification (RM) enzymes are molecular machines found in the majority of bacterial species. Their early discovery paved the way for the development of genetic engineering. They control (restrict) the influx of foreign DNA via horizontal gene transfer into the bacterium while maintaining sequence-specific methylation (modification) of host DNA. The endonuclease reaction of these enzymes on unmethylated DNA is preceded by bidirectional translocation of thousands of base pairs of DNA toward the enzyme. We present the structures of two type I RM enzymes, EcoKI and EcoR124I, derived using electron microscopy (EM), small-angle scattering (neutron and X-ray), and detailed molecular modeling. DNA binding triggers a large contraction of the open form of the enzyme to a compact form. The path followed by DNA through the complexes is revealed by using a DNA mimic anti-restriction protein. The structures reveal an evolutionary link between type I RM enzymes and type II RM enzymes.

Structural and functional analysis of the engineered type I DNA methyltransferase EcoR124I(NT).

The Type I R-M system EcoR124I is encoded by three genes. HsdM is responsible for modification (DNA methylation), HsdS for DNA sequence specificity and HsdR for restriction endonuclease activity. The trimeric methyltransferase (M(2)S) recognises the asymmetric sequence (GAAN(6)RTCG). An engineered R-M system, denoted EcoR124I(NT), has two copies of the N-terminal domain of the HsdS subunit of EcoR124I, instead of a single S subunit with two domains, and recognises the symmetrical sequence GAAN(7)TTC. We investigate the methyltransferase activity of EcoR124I(NT), characterise the enzyme and its subunits by analytical ultracentrifugation and obtain low-resolution structural models from small-angle neutron scattering experiments using contrast variation and selective deuteration of subunits.

Low sequence similarity and gene content of symbiotic clusters of Bradyrhizobium sp. WM9 (Lupinus) indicate early divergence of "lupin" lineage in the genus Bradyrhizobium.

Two sequenced nodulation regions of lupin Bradyrhizobium sp. WM9 carried the majority of genes involved in the Nod factor production. The nod region I harbored: nolA, nodD, nodA, nodB, nodC, nodS, nodI, nodJ, nolO, nodZ, fixR, nifA, fixA, nodM, nolK and noeL. This gene arrangement resembled that found in the nodulation region of Bradyrhizobium japonicum USDA110, however strain WM9 harbored only one nodD gene copy, while the nodM, nolK and noeL genes had no counterparts in the 410 kb symbiotic region of strain USDA110. Region II harbored nolL and nodW, but lacked an nodV gene. Both regions carried ORFs that lacked similarity to the published USDA110 sequences, though they had homologues in symbiotic regions of Rhizobium etli, Sinorhizobium sp. NGR234 and Mesorhizobium loti. These differences in gene content, as well as a low average sequence identity (70%) of symbiotic genes with respect to B. japonicum USDA110 were in contrast with the phylogenetic relationship of USDA110 and WM9 revealed by the analysis of 16S rDNA and dnaK sequences. This most likely reflected an early divergence of symbiotic loci, and possible co-speciation with distinct legumes. During this process the loss of a noel gene and the acquisition of a nolL gene could be regarded as an adaptation towards these legumes that responded to Nod factors carrying 4-O-acetylfucose rather than 2-O-methylfucose. This explained various responses of lupins and serradella plants to infection by mutants in nodZ and nolL genes, knowing that serradella is a stringent legume while lupins are more promiscuous legumes.