Expression and secretion of human apolipoprotein A-I in the heart

Nuclear envelope-peripheral heterochromatin fractions contain multiple histone kinase activities. In vitro assays and amino-terminal sequencing show that one of these activities co-isolates with heterochromatin protein 1 (HP1) and phosphorylates histone H3 at threonine 3. Antibodies recognizing this post-translational modification reveal that in vivo phosphorylation at threonine 3 commences at early prophase in the vicinity of the nuclear envelope, spreads to pericentromeric chromatin during prometaphase and is fully reversed by late anaphase. This spatio-temporal pattern is distinct from H3 phosphorylation at serine 10, which also occurs during cell division, suggesting segregation of differentially phosphorylated chromatin to different regions of mitotic chromosomes.     

Mediation by indole analogues of electron transfer during oxygen activation in variants of Escherichia coli ribonucleotide reductase R2 lacking the electron-shuttling tryptophan 48

Activation of dioxygen by the carboxylate-bridged diiron(II) cluster in the R2 subunit of class I ribonucleotide reductase from Escherichia coli results in the one-electron oxidation of tyrosine 122 (Y122) to a stable radical (Y122*). A key step in this reaction is the rapid transfer of a single electron from a near-surface residue, tryptophan 48 (W48), to an adduct between O(2) and diiron(II) cluster to generate a readily reducible cation radical (W48(+)(*)) and the formally Fe(IV)Fe(III) intermediate known as cluster X. Previous work showed that this electron injection step is blocked in the R2 variant with W48 replaced by phenylalanine [Krebs, C., Chen, S., Baldwin, J., Ley, B. A., Patel, U., Edmondson, D. E., Huynh, B. H., and Bollinger, J. M., Jr. (2000) J. Am. Chem. Soc. 122, 12207-12219]. In this study, we show that substitution of W48 with alanine similarly disables the electron transfer (ET) but also permits its chemical mediation by indole compounds. In the presence of an indole mediator, O(2) activation in the R2-W48A variant produces approximately 1 equiv of stable Y122* and more than 1 equiv of the normal (micro-oxo)diiron(III) product. In the absence of a mediator, the variant protein generates primarily altered Fe(III) products and only one-fourth as much stable Y122* because, as previously reported for R2-W48F, most of the Y122* that is produced decays as a consequence of the inability of the protein to mediate reductive quenching of one of the two oxidizing equivalents of the initial diiron(II)-O(2) complex. Mediation of ET is effective in W48A variants containing additional substitutions that also impact the reaction mechanism or outcome. In the reaction of R2-W48A/F208Y, the presence of mediator suppresses formation of the Y208-derived diiron(III)-catecholate product (which is predominant in R2-F208Y in the absence of reductants) in favor of Y122*. In the reaction of R2-W48A/D84E, the presence of mediator affects the outcome of decay of the peroxodiiron(III) intermediate known to accumulate in D84E variants, increasing the yield of Y122* by as much as 2.2-fold to a final value of 0.75 equiv and suppressing formation of a 490 nm absorbing product that results from decay of the two-electron oxidized intermediate in the absence of a functional ET apparatus.     

Cephalosporium maydis is a distinct species in the Gaeumannomyces-Harpophora species complex

Cephalosporium maydis is an important plant pathogen whose phylogenetic position relative to other fungi has not been established clearly. We compared strains of C. maydis, strains from several other plant-pathogenic Cephalosporium spp. and several possible relatives within the Gaeumannomyces-Harpophora species complex, to which C. maydis has been suggested to belong based on previous preliminary DNA sequence analyses. DNA sequences of the nuclear genes encoding the rDNA ITS region, β-tubulin, histone H3, and MAT-2 support the hypothesis that C. maydis is a distinct taxon within the Gaeumannomyces-Harpophora species complex. Based on amplified fragment length polymorphism (AFLP) profiles, C. maydis also is distinct from the other tested species of Cephalosporium, Phialophora sensu lato and members of Gaeumannomyces-Harpophora species complex, which supports its classification as Harpophora maydis. Oligonucleotide primers for H. maydis were developed that can be used in a PCR diagnostic protocol to rapidly and reliably detect and identify this pathogen. These diagnostic PCR primers will aid the detection of H. maydis in diseased maize because this fungus can be difficult to detect and isolate, and the movement of authentic cultures may be limited by quarantine restrictions.     

Effects of high-relief structures on cold temperate fish assemblages: A field experiment

High-relief structures may influence the abundance and diversity of reef-associated fish. We conducted a field experiment to investigate whether the presence of vertical structures (PVC pipes) affects fish communities on artificial reefs. The effect of the height of the structures (1 and 3 m) was also tested. Furthermore, the effects on fish of placing artificial reefs on otherwise featureless bottoms were quantified. Algal and macro-invertebrate colonization of the reefs was also recorded. The experiment was carried out on the west coast of Sweden over a period of 1 year. The vertical structures had a positive effect on fish abundance but not on diversity. The height of the structures did not, however, influence the fish communities. Natural as well as urban vertical structures on the seafloor could have a positive effect on local fish abundance. The positive effects of artificial reefs on total fish abundance and diversity were immediate. Of the 10 species recorded, two, the black goby Gobius niger and the goldsinny wrasse Ctenolabrus rupestris, dominated over the whole survey period. There were significant temporal differences in fish abundance, and diversity increased with time.     

High incidence of deafness from three frequent connexin 26 mutations in an isolated community

In a small village founded by few ancestors, three mutations in GJB2, the gene for connexin 26, are responsible for the high prevalence of deafness. A total of 15% of healthy individuals from a random sample were carriers of either 35Gdel (7.8%), W77R (2.4%), or V37I (4.8%). The three mutations appeared in the village approximately 100-150 years ago. The question of why three distinct mutations of similar age are observed at high frequency within a genetic isolate is discussed.     

Anti-biofilm activity of Salvadora persica on cariogenic isolates of Streptococcus mutans: in vitro and molecular docking studies

Salvadora persica sticks are used for chewing and oral-hygiene measures worldwide. The growth inhibition and anti-biofilm effects of various extracts on cariogenic Streptococcus mutans isolates were evaluated. Biofilm inhibition, gas chromatography-mass spectrometry (GC-MS) analyses for phytochemicals and their possible mode of interaction with biofilm response regulators were revealed using LigandFit docking protocols. All S. persica extracts showed considerable inhibitory activity and the cariogenic S. mutans showed varied susceptibility when compared with controls. The percentage reduction in biofilm inhibition obtained for methanol, ethanol, chloroform, acetone, and aqueous extracts were 87.92%, 85.75%, 72.44%, 61.66% and 58.68%, respectively. GC-MS analyses revealed?>28 compounds, of which benzyl (6Z,9Z,12Z)-6,9,12-octadecatrienoate, 3-benzyloxy-1-nitro-butan-2-ol and 1,3-cyclohexane dicarbohydrazide interacted efficiently with the bacterial communication quorum-sensing (QS) regulators Streptococcus OmpP and Staphylococcus Lux proteins. The bioactive, dual-function, anti-biofilm agents in S. persica not only inhibit growth, but also control the colonization and accumulation of caries-causing S. mutans.     

Chemical alterations taken place during deep-fat frying based on certain reaction products: A review

Deep-fat frying at 180°C or above is one of the most common food processing methods used for preparing of human kind foods worldwide. However, a serial of complex reactions such as oxidation, hydrolysis, isomerization, and polymerization take place during the deep-fat frying course and influence quality attributes of the final product such as flavor, texture, shelf life and nutrient composition. The influence of these reactions results from a number of their products including volatile compounds, hydrolysis products, oxidized triacylglycerol monomers, cyclic compounds, trans configuration compounds, polymers, sterol derivatives, nitrogen- and sulphur-containing heterocyclic compounds, acrylamide, etc. which are present in both frying oil and the fried food. In addition, these reactions are interacted and influenced by various impact factors such as frying oil type, frying conditions (time, temperature, fryer, etc.) and fried material type. Based on the published literatures, three main organic chemical reaction mechanisms namely hemolytic, heterolytic and concerted reaction were identified and supposed to elucidate the complex chemical alterations during deep-fat frying. However, well understanding the mechanisms of these reactions and their products under different conditions helps to control the deep-fat frying processing; therefore, producing healthy fried foods. By means of comprehensively consulting the papers which previously studied on the chemical changes occurred during deep-fat frying process, the major reaction products and corresponding chemical alterations were reviewed in this work.     

Genetic differentiation among migrant and resident populations of the threatened Asian houbara bustard

The Asian houbara bustard Chlamydotis macqueenii is a partial migrant of conservation concern found in deserts of central Asia and the Middle East. In the southern part of the species range, resident populations have been greatly fragmented and reduced by sustained human pressure. In the north, birds migrate from breeding grounds between West Kazakhstan and Mongolia to wintering areas in the Middle East and south central Asia. Extensive satellite tracking has shown substantial partitioning in migration routes and wintering grounds, suggesting a longitudinal barrier to present-day gene flow among migrants. In this context, we explored genetic population structure using 17 microsatellite loci and sampling 108 individuals across the range. We identified limited but significant overall differentiation (F(CT) = 0.045), which was overwhelmingly due to the differentiation of resident Arabian populations, particularly the one from Yemen, relative to the central Asian populations. Population structure within the central Asian group was not detectable with the exception of subtle differentiation of West Kazakh birds on the western flyway, relative to eastern populations. We interpret these patterns as evidence of recent common ancestry in Asia, coupled with a longitudinal barrier to present-day gene flow along the migratory divide, which has yet to translate into genetic divergence. These results provide key parameters for a coherent conservation strategy aimed at preserving genetic diversity and migration routes.     

Myxobolus myleus n. sp. infecting the bile of the Amazonian freshwater fish Myleus rubripinnis (Teleostei: Serrasalmidae): morphology and pathology

Myxobolus myleus n. sp. is described from the gall-bladder of the freshwater fish Myleus rubripinnis collected near the city of Oriximiná in the Amazon System, Brazil. The spores obtained from the bile contained two equal symmetrical and smooth valves, each forming the spore wall. The spores were large, with a cone-like form, a semi spherical basal contour and measured (in μm) 19.3 ± 0.5 (n = 25) × 8.3 ± 0.5 (n = 25) × 4.0 ± 0.3 (n = 15). The apical end of the spores contained two elongate, equal and pointed conical polar capsules measuring 13.2 ± 0.4 μm (n = 25) in length and 3.0 ± 0.3 μm (n = 15) in width, each having a slightly tapering polar filament with 19 to 21 turns. The polar capsules were extended below at about 4/5 of the total length of the spores. The sporoplasm was binucleate and contained some sporoplasmosomes. All infected fish presented hypertrophy of the gall-bladder due to presence of the brownish parasite floating in the bile. In this paper we describe this new species of myxosporean based on light and ultrastructural observations, together with its associated pathology.