48 research outputs found
Pathogenicity test of Western Australian isolates of Sclerotinia sclerotiorum in canola
Stem rot disease caused by Sclerotinia sclerotiorum has emerged as a serious problem on canola (Brassica napus L.) production in Western Australia (WA) over the past few years where crop losses can be up to 40% in the worst affected crops. Hundreds of isolates of S. sclerotiorum have been collected from different canola growing regions of WA. As the majority of WA isolates of S. sclerotiorum have not been analyzed for their genetic characterization, analysis of genetic variation of WA isolates will be undertaken using classical and molecular techniques such as pathogenicity test, mycelial compatibility groups (MCGs), ITS sequencing, and cluster analysis. The experiments which started in March 2013, aim to use classical and molecular tools to identify groups of WA isolates of S. sclerotiorum from which isolates will be selected for the main studies on the management of S. sclerotiorum in canola. Accurate information of genetic diversity through research on characterization of the pathogen will lead to better understanding of the pathogen and will also benefit the breeding programs particularly aiming at breeding for disease resistance and moreover, could lead to developing better techniques for managing the disease. The paper provides an outline of the experiments and preliminary results
Handheld imaging photonic crystal biosensor for multiplexed, label-free protein detection.
We present a handheld biosensor system for the label-free and specific multiplexed detection of several biomarkers employing a spectrometer-free imaging measurement system. A photonic crystal surface functionalized with multiple specific ligands forms the optical transducer. The photonic crystal slab is fabricated on a glass substrate by replicating a periodic grating master stamp with a period of 370 nm into a photoresist via nanoimprint lithography and deposition of a 70-nm titanium dioxide layer. Capture molecules are coupled covalently and drop-wise to the photonic crystal surface. With a simple camera and imaging optics the surface-normal transmission is detected. In the transmission spectrum guided-mode resonances are observed that shift due to protein binding. This shift is observed as an intensity change in the green color channel of the camera. Non-functionalized image sections are used for continuous elimination of background drift. In a first experiment we demonstrate the specific and time-resolved detection of 90.0 nm CD40 ligand antibody, 90.0 nM EGF antibody, and 500 nM streptavidin in parallel on one sensor chip. In a second experiment, aptamers with two different spacer lengths are used as receptor. The binding kinetics with association and dissociation of 250 nM thrombin and regeneration of the sensor surface with acidic tris-HCl-buffer (pH 5.0) is presented for two measurement cycles
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The albumin-bilirubin grade uncovers the prognostic relationship between hepatic reserve and immune dysfunction in HIV-associated hepatocellular carcinoma.
BACKGROUND: Hepatocellular carcinoma (HCC) is a leading cause of liver-related mortality in people living with HIV, where co-infection with hepatotropic viruses accelerates the course of chronic liver disease. AIM: To evaluate whether the albumin-bilirubin (ALBI) grade, a more accurate marker of liver dysfunction in HCC, might identify patients with progressive liver dysfunction in the context of HIV/hepatitis co-infection. METHODS: Using uni- and multi-variable analyses, we studied the albumin-bilirubin grade as a predictor of overall survival (OS) in a large, multi-center cohort of patients with HIV-associated HCC recruited from 44 centres in 9 countries within the Liver Cancer in HIV study group. Patients who underwent liver transplantation were excluded. RESULTS: A total of 387 patients, predominantly HCV co-infected (78%) with balanced representation of all Barcelona Clinic Liver Cancer (BCLC) stages (AÂ =Â 33%, BÂ =Â 18%, CÂ =Â 37%, DÂ =Â 12%) were recruited. At HCC diagnosis, 84% had been on anti-retrovirals for a median duration of 8.8Â years. The albumin-bilirubin grade identified significant differences in median survival of 97Â months for grade 1 (95% CI 13-180Â months), 17Â months for grade 2 (95% CI 11-22Â months) and 6Â months for grade 3 (95% CI 4-9Â months, PÂ <Â .001). A more advanced albumin-bilirubin grade correlated with lower CD4 counts (464/373/288 cells/mm3 for grades 1/2/3) and higher HIV viraemia (3.337/8.701/61.845 copies/mL for grades 1/2/3, PÂ <Â .001). CONCLUSIONS: In this large, multi-center retrospective study, the albumin-bilirubin grade highlights the interplay between liver reserve and immune dysfunction as prognostic determinants in HIV-associated HCC
Tocilizumab in Hospitalized Patients with Severe Covid-19 Pneumonia
BACKGROUND
Coronavirus disease 2019 (Covid-19) is associated with immune dysregulation and hyperinflammation, including elevated interleukin-6 levels. The use of tocilizumab, a monoclonal antibody against the interleukin-6 receptor, has resulted in better outcomes in patients with severe Covid-19 pneumonia in case reports and retrospective observational cohort studies. Data are needed from randomized, placebo-controlled trials.
METHODS
In this phase 3 trial, we randomly assigned patients who were hospitalized with severe Covid-19 pneumonia in a 2:1 ratio receive a single intravenous infusion of tocilizumab (at a dose of 8 mg per kilogram of body weight) or placebo. Approximately one quarter of the participants received a second dose of tocilizumab or placebo 8 to 24 hours after the first dose. The primary outcome was clinical status at day 28 on an ordinal scale ranging from 1 (discharged or ready for discharge) to 7 (death) in the modified intention-to-treat population, which included all the patients who had received at least one dose of tocilizumab or placebo.
RESULTS
Of the 452 patients who underwent randomization, 438 (294 in the tocilizumab group and 144 in the placebo group) were included in the primary and secondary analyses. The median value for clinical status on the ordinal scale at day 28 was 1.0 (95% confidence interval [CI], 1.0 to 1.0) in the tocilizumab group and 2.0 (non-ICU hospitalization without supplemental oxygen) (95% CI, 1.0 to 4.0) in the placebo group (between-group difference, −1.0; 95% CI, −2.5 to 0; P=0.31 by the van Elteren test). In the safety population, serious adverse events occurred in 103 of 295 patients (34.9%) in the tocilizumab group and in 55 of 143 patients (38.5%) in the placebo group. Mortality at day 28 was 19.7% in the tocilizumab group and 19.4% in the placebo group (weighted difference, 0.3 percentage points; 95% CI, –7.6 to 8.2; nominal P=0.94).
CONCLUSIONS
In this randomized trial involving hospitalized patients with severe Covid-19 pneumonia, the use of tocilizumab did not result in significantly better clinical status or lower mortality than placebo at 28 days. (Funded by F. Hoffmann–La Roche and the Department of Health and Human Services; COVACTA ClinicalTrials.gov number, NCT04320615
Glycogen resynthesis in the absence of food ingestion during recovery from moderate or high intensity physical activity: Novel insights from rat and human studies
The finding that during recovery from high intensity exercise, rats have the capacity to replenish their muscle glycogen stores even in the absence of food intake has provided us with an experimental model of choice to explore further this process. Our objective here is to share those questions arising from research carried out by others and ourselves on rats and humans that are likely to be of interest to comparative biochemists/physiologists. On the basis of our findings and those of others, it is proposed that across vertebrate species: (1) the capacity of muscles to replenish their glycogen stores from endogenous carbon sources is dependent on the type of physical activity and animal species; (2) lactate and amino acids are the major endogenous carbon sources mobilized for the resynthesis of muscle glycogen during recovery from exercise, their relative contributions depending on the duration of recovery and type of exercise; (3) the relative contributions of lactate glyconeogenesis and hepatic/renal gluconeogenesis to muscle glycogen synthesis is species- and muscle fiber-dependent; and (4) glycogen synthase and phosphorylase play an important role in the control of the rate of glycogen synthesis post-exercise, with the role of glucose transport being species-dependent
Increased yield of a lysozyme after self-cloning of the gene in Streptomyces coelicolor "Müller"
Bräu B, Hilgenfeld R, Schlingmann M, et al. Increased yield of a lysozyme after self-cloning of the gene in Streptomyces coelicolor "Müller". Applied Microbiology and Biotechnology. 1991;34(4):481-487.Streptomyces coelicolor "Muller" DSM3030 excretes a lysozyme comprising both-beta-1,4-N-acetyl- and beta-1,4-N,6-O-diacetyl muramidase activities. The lysozyme is named Cellosyl. Gene libraries have been established using genomic DNA from the wild-type strain, S. coelicolor DSM3030, and from an overproducing mutant, S. coelicolor HP1, which exhibits about a twofold increase in lysozyme production. The lysozyme-encoding genes (cel) from both strains were detected by oligodeoxynucleotide hybridization. The nucleotide sequence of the cel genes isolated from both strains was shown to be identical. The different levels of lysozyme production could not be correlated with any mutations at the cel gene locus. The cel gene isolated from the wild-type strain could not be expressed in some other species of Streptomyces. However, self-cloning of the cel gene into S. coelicolor DSM3030 and HP1 resulted in a 2.5-fold increase in lysozyme production