Tolerance to hepatitis B antigen: a hypothesis for its termination with 'immune-RNA'

Immunologic tolerance to hepatitis B antigen, evidenced by a lack of specific cellular and humoral immune response to HB_sAg, produces a chronic carrier state which serves as an epidemiologic reservoir for the transmission of viral hepatitis type B. It is proposed that cell-mediated immunity transferred with immune-RNA may serve to terminate immunologic tolerance to hepatitis B antigen and abolish the carrier state. The efficacy and safety of ‘immune-RNA’ administration to chronic carriers can be validated by leukocyte migration inhibition techniques $\text{in vitro}$ and in HB_sAg positive chimpanzees $\text{in vivo}$.     

Partial least squares for functional joint models with applications to the Alzheimer's disease neuroimaging initiative study

Many biomedical studies have identified important imaging biomarkers that are associated with both repeated clinical measures and a survival outcome. The functional joint model (FJM) framework, proposed by Li and Luo in 2017, investigates the association between repeated clinical measures and survival data, while adjusting for both high-dimensional images and low-dimensional covariates based on the functional principal component analysis (FPCA). In this paper, we propose a novel algorithm for the estimation of FJM based on the functional partial least squares (FPLS). Our numerical studies demonstrate that, compared to FPCA, the proposed FPLS algorithm can yield more accurate and robust estimation and prediction performance in many important scenarios. We apply the proposed FPLS algorithm to a neuroimaging study. Data used in preparation of this article were obtained from the Alzheimer's Disease Neuroimaging Initiative (ADNI) database.     

Honey bees can disseminate a microbial control agent to more than one inflorescence pest of oilseed rape

Pollen beetles (Meligethes aeneus) and cabbage seed weevils (Ceutorhynchus assimilis) are major pests of oilseed rape (Brassica napus) throughout Europe. In field cage experiments in both winter and spring rape, honey bees (Apis mellifera) effectively transported the entomopathogenic fungus Metarhizium anisopliae to the flowers, causing infection and mortality of both adult and larval pollen beetles, as well as of adult seed weevils. External conidiation was observed on many of the dead pest insects. Although some external conidiation also occurred on dead honey bees, reduction in honey bee colony size during the experiments appeared unrelated to the fungus. The potential of this technique for integration into pest management strategies for the crop, particularly in association with a trap crop, is discussed.     

In silico molecular docking analysis for repurposing approved antiviral drugs against SARS-CoV-2 main protease

Developing a safe and effective antiviral treatment takes a decade, however, when it comes to the coronavirus disease (COVID-19), time is a sensitive matter to slow the spread of the pandemic. Screening approved antiviral drugs against COVID-19 would speed the process of finding therapeutic treatment. The current study examines commercially approved drugs to repurpose them against COVID-19 virus main protease using structure-based in-silico screening. The main protease of the coronavirus is essential in the viral replication and is involved in polyprotein cleavage and immune regulation, making it an effective target when developing the treatment. A Number of approved antiviral drugs were tested against COVID-19 virus using molecular docking analysis by calculating the free natural affinity of the binding ligand to the active site pocket and the catalytic residues without forcing the docking of the ligand to active site. COVID-19 virus protease solved structure (PDB ID: 6LU7) is targeted by repurposed drugs. The molecular docking analysis results have shown that the binding of Remdesivir and Mycophenolic acid acyl glucuronide with the protein drug target has optimal binding features supporting that Remdesivir and Mycophenolic acid acyl glucuronide can be used as potential anti-viral treatment against COVID-19 disease.     

A Comparison of Effects of Broad-Spectrum Antibiotics and Biosurfactants on Established Bacterial Biofilms

Current antibiofilm solutions based on planktonic bacterial physiology have limited efficacy in clinical and occasionally environmental settings. This has prompted a search for suitable alternatives to conventional therapies. This study compares the inhibitory properties of two biological surfactants (rhamnolipids and a plant-derived surfactant) against a selection of broad-spectrum antibiotics (ampicillin, chloramphenicol and kanamycin). Testing was carried out on a range of bacterial physiologies from planktonic and mixed bacterial biofilms. Rhamnolipids (Rhs) have been extensively characterised for their role in the development of biofilms and inhibition of planktonic bacteria. However, there are limited direct comparisons with antimicrobial substances on established biofilms comprising single or mixed bacterial strains. Baseline measurements of inhibitory activity using planktonic bacterial assays established that broad-spectrum antibiotics were 500 times more effective at inhibiting bacterial growth than either Rhs or plant surfactants. Conversely, Rhs and plant biosurfactants reduced biofilm biomass of established single bacterial biofilms by 74–88 and 74–98 %, respectively. Only kanamycin showed activity against biofilms of Bacillus subtilis and Staphylococcus aureus. Broad-spectrum antibiotics were also ineffective against a complex biofilm of marine bacteria; however, Rhs and plant biosurfactants reduced biofilm biomass by 69 and 42 %, respectively. These data suggest that Rhs and plant-derived surfactants may have an important role in the inhibition of complex biofilms.     

Field dispersal of the parasitoid wasp Habrobracon hebetor (Hymenoptera: Braconidae) following augmentative release against the millet head miner Heliocheilus albipunctella (Lepidoptera: Noctuidae) in the Sahel

Pearl millet is one of the major staple food crops in Sub-Sahelian Africa, and the millet head miner (MHM) [Heliocheilus albipunctella] is its major pest, causing serious economic damage in the maturity period. We studied the dispersion patterns of the endogenous ectoparasitoid, Habrobracon hebetor (Hymenoptera: Braconidae), after augmentative releases in pearl millet fields for biological control of the MHM, in 2010 and 2011 in Burkina Faso and Niger. The parasitoids were released using 15 jute bags per release site. Parasitoid dispersion was indirectly monitored through weekly assessments of MHM parasitism by H. hebetor at different distances from release points (0, 3 and 5?km) and in control villages (15?km). Our findings indicate that the jute bags released approximately 900–1000 parasitoids per site over a period of three weeks. This initial parasitoid population led to higher parasitism of MHM larvae at the site of dissemination compared to farms at distances of 3 and 5?km. However, usually after five weeks, successive generations of H. hebetor dispersed up to 3?km, causing high levels of MHM larval mortality, which sometimes is similar to those of the release points. Based on these results, we recommend the release of parasitoids at sites spaced 3?km for timely and more efficient control of MHM populations.     

Evaluation of a centrifuge method and thin-layer preparation in urine cytology

OBJECTIVE: To evaluate and compare the quality and cost of urine cytology using the Cytospin method (Shandon, ThermoElectron Corporation, Waltham, Massachusetts, U.S.A.) and the AutoCyte PREP (TriPath Imaging, Burlington, North Carolina, U.S.A.) in a general laboratory. STUDY DESIGN: A study of differences between the Cytospin method and AutoCyte PREP in the areas of specimen preparation, staining, number and quality of diagnostic cells, background, screener preference, and cost was undertaken over a 3-month period in 2000. Sixty fresh voided urine samples from 25 patients with known transitional cell carcinoma were prepared by the Cytospin method and the AutoCyte PREP according to the manufacturers' instructions. RESULTS: The Cytospin method had longer preparation time but shorter screening time than the AutoCyte PREP. The number of diagnostic cells was higher in the Cytospin method. Fixation quality and staining clarity were better in the Cytospin method. Qualitative assessment of cell arrangements, cell and nuclear size and shape, nuclear/cytoplasmic ratio and nuclear membrane irregularity showed no significant differences between the 2 methods. Cellular details and nuclear chromatin patterns were clearer and better preserved in the Cytospin method, but the AutoCyte PREP showed less blood and inflammatory cells and debris. CONCLUSION: In the majority of cases the screeners preferred the Cytospin method due to its better overall cytologic quality. However, the amount of blood, inflammation and debris was much lower in the AutoCyte PREP. This reduced the need to make a second, diluted specimen and made turnaround time faster. The AutoCyte PREP was 7 times more expensive than the Cytospin method.     

Decomposition of cellulose,soil organic matter and plant litter in a temperate grassland soil

The formation of mor humus in an experimental grassland plot, which has been acidified by long-term fertiliser treatment, has been studied by comparing the rates of cellulose, soil organic matter and plant litter decay with those in an adjacent plot with near-neutral pH and mull humus. The decomposition of cellulose filter paper in litter bags of 5 mm, 1-mm and 45-μm mesh size buried at 3 to 4 cm depth the plots was followed by measuring the weight loss and changes in glucose content over a 6 month period. Soil pH was either 5.3 or 4.3. Decomposition of native soil organic matter and plant litter in soil from the same plots were followed using CO₂ evolution in laboratory microcosms. Cellulose weight loss at pH 5.3 was greatest from the 5-mm mesh bags and least from the 45-um mesh bags. At pH 4.3 there was little weight loss from bags and no significant differences in weight loss between bags with different sized mesh. There was, however, a reduction in the glucose content of the hydrolysed and derivatised filter paper with time. The decomposition rate of native soil organic matter in the low pH soil was increased to that observed in the less acid soil when the pH of the former was increased from 4.3 to 5.3. The increase in decomposition rate of added plant litter in the more acid soil as a result of CA(OH)₂ addition was only 60% of that observed in the soil with pH 5.3. These data support the hypothesis that the absence of soil animals and the restricted microbial decomposition in the acidic soil was responsible for mor humus formation.     

Glycosylation of 2-Thiouracil Derivatives. A Synthetic Approach to 3-Glycosyl-2, 4-dioxypyrimidines

Abstract

Reaction of 6-aryl-5-cyano-2-thiouracils 2a-d with glycosyl halides 4a,b under alkaline conditions gave the respective bisglycosylated derivatives 5a-h. However, their deacetylation with ammonia in methanol caused a cleavage of the S-glycosyl residue and gave the N-3 glycosylated analogues 6a-h.     

Enhancing antimicrobial properties of dyed and finished cotton fabrics

1,2,3-Benzothiazole-7-thiocarboxylic acid-S-methylester (commercially known as Actigard^® AM-87) was utilized to impart cotton fabric durable antimicrobial properties. Finishing treatment was carried out under a variety of conditions. The latter were included, effect of pH, concentration of antibacterial agents, curing temperature and curing time. The effect of fabric construction, mercerization, and dyeing with different dyestuff were also investigated. The study was also extended to investigate the technical feasibility of combining antimicrobial finishing treatment in question with other finishing treatment generally carried out on cotton fabric, like soft finishing and crease recovery finishing. The treated fabrics were monitored for antimicrobial properties before and after washing. The treated fabrics were also evaluated for the physio-mechanical properties like fabric tensile strength, elongation at break (or bursting strength for knitted fabric), wettability, crease recovery angle, whiteness index and roughness. Results obtained show that, the most appropriate conditions for treatment cotton fabric with Actigard^® are: padding the cotton fabric in aqueous solution containing 6% Actigard^® at pH 5 (adjusted using formic acid) then squeezed to wet pick up of 100%, dried at 80 °C for 5 min then cured at 100 °C for 150 s. The untreated cotton fabric did not show any antimicrobial activity towards Staphylococcus aureus or Escherichia coli. Treatment of cotton fabric with Actigard^® improves its antimicrobial properties towards S. aureus or E. coli. It is also observed that, treatment of cotton fabric with Actigard^® marginally decreases fabric tensile strength, elongation at break, roughness and WI, whereas; both wettability and crease recovery angle remain practically intact. This was observed whether the fabric was pre-mercerized or not.