The parasitic mite Varroa destructor has a significant worldwide impact on bee colony health. In the absence of control measures, parasitized colonies invariably collapse within 3 years. The ...synthetic pyrethroids tau-fluvalinate and flumethrin have proven very effective at managing this mite within apiaries, but intensive control programs based mainly on one active ingredient have led to many reports of pyrethroid resistance. In Europe, a modification of leucine to valine at position 925 (L925V) of the V. destructor voltage-gated sodium channel was correlated with resistance, the mutation being found at high frequency exclusively in hives with a recent history of pyrethroid treatment. Here, we identify two novel mutations, L925M and L925I, in tau-fluvalinate resistant V. destructor collected at seven sites across Florida and Georgia in the Southeastern region of the USA. Using a multiplexed TaqMan® allelic discrimination assay, these mutations were found to be present in 98% of the mites surviving tau-fluvalinate treatment. The mutations were also found in 45% of the non-treated mites, suggesting a high potential for resistance evolution if selection pressure is applied. The results from a more extensive monitoring programme, using the Taqman® assay described here, would clearly help beekeepers with their decision making as to when to include or exclude pyrethroid control products and thereby facilitate more effective mite management programmes.
The secondary migration of petroleum is one of the most critical geological processes responsible for the accumulation of hydrocarbons in a sedimentary basin. Pyrrolic nitrogen compounds such as ...carbazoles and benzocarbazoles are thought to be practical molecular indicators for estimating relative migration distances of oil. In light oils or condensates, however, considerable analytical errors are usually caused by low concentrations of NSO-compounds. Here we show that polycyclic sulfur aromatic hydrocarbons such as dibenzothiophene, C1∼C3 alkylated dibenzothiophenes and benzobnaphthothiophenes, which are present in relatively higher concentrations than the pyrrolic nitrogen compounds, exhibit changes in both absolute and relative concentrations that correlate with migration distances. The polycyclic sulfur aromatic hydrocarbons related parameters — benzobnaphtho2,1-dthiophene/{benzobnaphtho2,1-dthiophene + benzobnaphtho1,2-dthiophene} (abbreviated as 2,1BNT/(2,1BNT+1,2BNT) and the concentration of total dibenzothiophenes plus benzobnaphthothiophenes — are proposed by this paper to trace the oil migration distances.
•Hydrogen bond suggests migration fractionation effect of dibenzothiophenes in oil.•Summed concentrations of dibenzothiophenes correlate well with oil migration distance.•Relative content of benzonaphthothiophene was used to trace oil migration distance.•The effects of source maturity and depositional environment are considered.
The chemical and physical resemblance between selenium (Se) and sulfur (S) establishes that both these elements share common metabolic pathways in plants. The presence of isologous Se and S compounds ...indicates that these elements compete in biochemical processes that affect uptake, translocation and assimilation throughout plant development. Yet, minor but crucial differences in reactivity and other metabolic interactions infer that some biochemical processes involving Se may be excluded from those relating to S. This review examines the current understanding of physiological and biochemical relationships between S and Se metabolism by highlighting their similarities and differences in relation to uptake, transport and assimilation pathways as observed in Se hyperaccumulator and non-accumulator plant species. The exploitation of genetic resources used in bioengineering strategies of plants is illuminating the function of sulfate transporters and key enzymes of the S assimilatory pathway in relation to Se accumulation and final metabolic fate. These strategies are providing the basic framework by which to resolve questions relating to the essentiality of Se in plants and the mechanisms utilized by Se hyperaccumulators to circumvent toxicity. In addition, such approaches may assist in the future application of genetically engineered Se accumulating plants for environmental renewal and human health objectives.
Aims To determine levels of microsomal protein (MPPGL) and hepatocellularity (HPGL) per gram of human liver and their interindividual variability.
Methods Triplicate liver samples were used to ...determine values of MPPGL (n = 20) and HPGL (n = 7) after accounting for the fractional loss of microsomal protein or hepatocytes during processing. Repeated measurements from each liver sample allowed the estimation of true interindividual variability in MPPGL and HPGL using ANOVA.
Results The value of MPPGL ranged from 26 to 54 mg g−1 (meangeo= 33 mg g−1). The value of HPGL ranged from 65 to 185 × 106 cells g−1 (meangeo= 107 × 106 cells g−1).
Conclusions There is significant interindividual variability in MPPGL, which has implications for the accurate extrapolation of in vitro data on drug metabolism to predict in vivo metabolic clearance.
Exploring the Glycans of Euglena gracilis O'Neill, Ellis C; Kuhaudomlarp, Sakonwan; Rejzek, Martin ...
Biology (Basel, Switzerland),
12/2017, Volume:
6, Issue:
4
Journal Article
Peer reviewed
Open access
is an alga of great biotechnological interest and extensive metabolic capacity, able to make high levels of bioactive compounds, such as polyunsaturated fatty acids, vitamins and β-glucan. Previous ...work has shown that Euglena expresses a wide range of carbohydrate-active enzymes, suggesting an unexpectedly high capacity for the synthesis of complex carbohydrates for a single-celled organism. Here, we present an analysis of some of the carbohydrates synthesised by
. Analysis of the sugar nucleotide pool showed that there are the substrates necessary for synthesis of complex polysaccharides, including the unusual sugar galactofuranose. Lectin- and antibody-based profiling of whole cells and extracted carbohydrates revealed a complex galactan, xylan and aminosugar based surface. Protein
-glycan profiling, however, indicated that just simple high mannose-type glycans are present and that they are partially modified with putative aminoethylphosphonate moieties. Together, these data indicate that Euglena possesses a complex glycan surface, unrelated to plant cell walls, while its protein glycosylation is simple. Taken together, these findings suggest that
may lend itself to the production of pharmaceutical glycoproteins.
This statement revises a previous statement on screening of preterm infants for retinopathy of prematurity (ROP) that was published in 2001. ROP is a pathologic process that occurs only in immature ...retinal tissue and can progress to a tractional retinal detachment, which can result in functional or complete blindness. Recent development of peripheral retinal ablative therapy using laser photocoagulation has resulted in the possibility of markedly decreasing the incidence of this poor visual outcome, but the sequential nature of ROP creates a requirement that at-risk preterm infants be examined at proper times to detect the changes of ROP before they become permanently destructive. This statement presents the attributes on which an effective program for detecting and treating ROP could be based, including the timing of initial examination and subsequent reexamination intervals.
Bartonella species were isolated from the blood of 63 of 325 Rattus norvegicus and 11 of 92 Rattus rattus from 13 sites in the United States and Portugal. Infection in both Rattus species ranged from ...0% (e.g., 0/87) to ∼60% (e.g., 35/62). A 337-bp fragment of the citrate synthase (gltA) gene amplified by polymerase chain reaction was sequenced from all 74 isolates. Isolates from R. norvegicus were most similar to Bartonella elizabethae, isolated previously from a patient with endocarditis (93%–100% sequence similarity), followed by Bartonella grahamii and other Bartonella species isolated from Old World rodents (Clethrionomys species, Mus musculus, and Rattus species). These data suggest that Rattus species are a reservoir host for pathogenic Bartonella species and are consistent with a hypothesized Old World origin for Bartonella species recovered from Rattus species introduced into the Americas.
The potency of methylenedioxymethamphetamine (MDMA) as a mechanism-based inhibitor of CYP2D6 has been defined using microsomes prepared from yeast expressing the enzyme and from three human livers. ...The inhibitory effect was increased by preincubation through formation of a metabolic intermediate complex. Inactivation parameters (kinact and KI), defined with respect to the O-demethylation of dextromethorphan, were 0.29 +/- 0.03 (S.E.) min(-1) and 12.9 +/- 3.6 (S.E.) microM for yeast-expressed CYP2D6, and 0.26 +/- 0.02 min(-1) and 14.4 +/- 2.5 microM, 0.15 +/- 0.01 min(-1) and 8.8 +/- 2.6 microM, and 0.12 +/- 0.05 min(-1) and 45.3 +/- 32.1 microM for the liver microsomal preparations. The rate of inactivation of CYP2D6 by MDMA decreased when quinidine, a competitive inhibitor of CYP2D6, was added to the primary incubation mixture. However, inactivation was unaffected by the addition of glutathione. The results indicate that MDMA is a potent mechanism-based inhibitor of CYP2D6, with implications for understanding its in vivo disposition and drug interaction potential.
A faint star located 2 arcsec from KIC 8462852 was discovered in Keck 10 m adaptive optics imaging in the JHK near-infrared (NIR) in 2014 by Boyajian et al. (2016). The closeness of the star to KIC ...8462852 suggested that the two could constitute a binary, which might have implications for the cause of the brightness dips seen by Kepler and in ground-based optical studies. Here, NIR imaging in 2017 using the Mimir instrument resolved the pair and enabled measuring their separation. The faint star had moved 67 7 milliarcsec (mas) relative to KIC 8462852 since 2014. The relative proper motion of the faint star is 23.9 2.6 mas yr−1, for a tangential velocity of 45 5 km s−1 if it is at the same 390 pc distance as KIC 8462852. Circular velocity at the 750 au current projected separation is 1.5 km s−1, hence the star pair cannot be bound.
PDF
![Benzo[b]naphthothiophenes a...](http://api.summon.serialssolutions.com/2.0.0/image/issn/XR4PS5YY4K/0264-8172/small "Benzo[b]naphthothiophenes and alkyl dibenzothiophenes: Molecular tracers for oil migration distances")
