Influence of chemical and physical conditions on the production of bacteriocin by Aeromonas hydrophila

Aeromonas hydrophila have been isolated as a cause of a cute gastroenteritis in 23 (5.6%) of 410 patients. Other bacterial enteropathogens have been isolated from 387 patients with diarrhea, were 19 different strains. A. hydrophila occurred more commonly in children with acute diarrhea, the results showed that 18(78.26%) isolates of A. hydrophila found in children under 10 years old ,distributed to 10(43.47%) in male and 8(34.78%) in female ,and in adults with diarrhea 5 (21.73%). In the other hand, we noticed frequency of isolation was higher in male 14(60.86%) when compared with 9(39.14%) in female. Six strains of A. hydrophila have been observed to have bacteriocin activity against 12 of 23 different A. hydrophila ,as well as Staphylococcus aureas, Pseudomonas aeruginosa, Escherichia coli, Enterobacter cloacea and Shigella dysenteria. The results showed Bacteriocin-like substances (BLS11) had isoinhibitory activity on 10 same A. hydrophila species and heteroinhibitory activity effects on all pathogenic bacterial strains used, while BLS5 showed isoinhibitory activity on 2 same A. hydrophila species and heteroinhibitory activity by effecting on gram negative only, and BLS3& BLS12 showed activity on E. coli isolates only, and none of BLS1& BLS10(isoinhibitory activity on 1 A.hydrophila respectively) had effect on all pathogenic bacteria. Among the standard laboratory media used Brain Heart Infusion broth (BHI) showed the maximum production and poor yields resulted from growth in Peptone Glyserol (PG) and Nutrient broth. We selected BLS11 to their wide range effect on same species and enteric pathogenic strains, to study the Influence of chemical and physical conditions on the production of BLS by A.hydrophila. The BLS11 preparations from A.hydrophila11 strains of A. hydrophila were tolerant to all three treatments of surfactant. In the other hand, effect of organic acid on BLS production BLS11 has been studied and showed no remarkable difference in zone of inhibition when used acetone as affecter element, while both of isopropanol and ethanol have narrow inhibition zone range when compared with control strain. These results indicated that most A. hydrophila might be harboring plasmid mediated bacteriocin like substance, and there are no relation between BLS production and number of plasmid bands present in bacteria

Therapeutic target-site variability in α1-antitrypsin characterized at high resolution

The intrinsic propensity of [alpha]1-antitrypsin to undergo conformational transitions from its metastable native state to hyperstable forms provides a motive force for its antiprotease function. However, aberrant conformational change can also occur via an intermolecular linkage that results in polymerization. This has both loss-of-function and gain-of-function effects that lead to deficiency of the protein in human circulation, emphysema and hepatic cirrhosis. One of the most promising therapeutic strategies being developed to treat this disease targets small molecules to an allosteric site in the [alpha]1-antitrypsin molecule. Partial filling of this site impedes polymerization without abolishing function. Drug development can be improved by optimizing data on the structure and dynamics of this site. A new 1.8 Å resolution structure of [alpha]1-antitrypsin demonstrates structural variability within this site, with associated fluctuations in its upper and lower entrance grooves and ligand-binding characteristics around the innermost stable enclosed hydrophobic recess. These data will allow a broader selection of chemotypes and derivatives to be tested in silico and in vitro when screening and developing compounds to modulate conformational change to block the pathological mechanism while preserving function

Critical change in the Fermi surface of iron arsenic superconductors at the onset of superconductivity

The phase diagram of a correlated material is the result of a complex interplay between several degrees of freedom, providing a map of the material's behavior. One can understand (and ultimately control) the material's ground state by associating features and regions of the phase diagram, with specific physical events or underlying quantum mechanical properties. The phase diagram of the newly discovered iron arsenic high temperature superconductors is particularly rich and interesting. In the AE(Fe1-xTx)2As2 class (AE being Ca, Sr, Ba, T being transition metals), the simultaneous structural/magnetic phase transition that occurs at elevated temperature in the undoped material, splits and is suppressed by carrier doping, the suppression being complete around optimal doping. A dome of superconductivity exists with apparent equal ease in the orthorhombic / antiferromagnetic (AFM) state as well as in the tetragonal state with no long range magnetic order. The question then is what determines the critical doping at which superconductivity emerges, if the AFM order is fully suppressed only at higher doping values. Here we report evidence from angle resolved photoemission spectroscopy (ARPES) that critical changes in the Fermi surface (FS) occur at the doping level that marks the onset of superconductivity. The presence of the AFM order leads to a reconstruction of the electronic structure, most significantly the appearance of the small hole pockets at the Fermi level. These hole pockets vanish, i. e. undergo a Lifshitz transition, at the onset of superconductivity. Superconductivity and magnetism are competing states in the iron arsenic superconductors. In the presence of the hole pockets superconductivity is fully suppressed, while in their absence the two states can coexist.Comment: Updated version accepted in Nature Physic

Scutellaria baicalensis

Antimycin A (AMA) damages mitochondria by inhibiting mitochondrial electron transport and can produce reactive oxygen species (ROS). ROS formation, aging, and reduction of mitochondrial biogenesis contribute to mitochondrial dysfunction. The present study sought to investigate extracts of Scutellaria baicalensis and its flavonoids (baicalin, baicalein, and wogonin), whether they could protect mitochondria against oxidative damage. The viability of L6 cells treated with AMA increased in the presence of flavonoids and extracts of S. baicalensis. ATP production decreased in the AMA treated group, but increased by 50% in cells treated with flavonoids (except wogonin) and extracts of S. baicalensis compared to AMA-treated group. AMA treatment caused a significant reduction (depolarized) in mitochondrial membrane potential (MMP), whereas flavonoid treatment induced a significant increase in MMP. Mitochondrial superoxide levels increased in AMA treated cells, whereas its levels decreased when cells were treated with flavonoids or extracts of S. baicalensis. L6 cells treated with flavonoids and extracts of S. baicalensis increased their levels of protein expression compared with AMA-treated cells, especially water extracts performed the highest levels of protein expression. These results suggest that the S. baicalensis extracts and flavonoids protect against AMA-induced mitochondrial dysfunction by increasing ATP production, upregulating MMP, and enhancing mitochondrial function

Effect of Uric Acid on the Development of Chronic Kidney Disease: The Korean Multi-Rural Communities Cohort Study

Objectives Several studies have investigated the effects of serum uric acid (SUA) levels on chronic kidney disease (CKD), with discrepant results. The effect of SUA levels on CKD development was studied in the Korean rural population. Methods A total of 9695 participants aged ≥40 years were recruited from 3 rural communities in Korea between 2005 and 2009. Of those participants, 5577 who participated in the follow-up and did not have cerebrovascular disease, myocardial infarction, cancer, or CKD at baseline were studied. The participants, of whom 2133 were men and 3444 were women, were grouped into 5 categories according to their quintile of SUA levels. An estimated glomerular filtration rate of <60 mL/min/1.73 m2 at the time of follow-up was considered to indicate newly developed CKD. The effects of SUA levels on CKD development after adjusting for potential confounders were assessed using Cox proportional hazard models. Results Among the 5577 participants, 9.4 and 11.0% of men and women developed CKD. The hazard ratio (HR) of CKD was higher in the highest quintile of SUA levels than in the third quintile in men (adjusted HR, 1.60; 95% confidence interval [CI], 1.02 to 2.51) and women (adjusted HR, 1.56; 95% CI, 1.14 to 2.15). Furthermore, CKD development was also more common in the lowest quintile of SUA levels than in the third quintile in men (adjusted HR, 1.83; 95% CI, 1.15 to 2.90). The effect of SUA was consistent in younger, obese, and hypertensive men. Conclusions Both high and low SUA levels were risk factors for CKD development in rural Korean men, while only high levels were a risk factor in their women counterparts

Superconducting Sr2RuO4 Thin Films without Out-of-Phase Boundaries by Higher-Order Ruddlesden-Popper Intergrowth

Ruddlesden-Popper (RP) phases (An+1B n O3n+1, n = 1, 2,···) have attracted intensive research with diverse functionalities for device applications. However, the realization of a high-quality RP-phase film is hindered by the formation of out-of-phase boundaries (OPBs) that occur at terrace edges, originating from lattice mismatch in the c-axis direction with the A'B'O3 (n = ∞) substrate. Here, using strontium ruthenate RP-phase Sr2RuO4 (n = 1) as a model system, an experimental approach for suppressing OPBs was developed. By tuning the growth parameters, the Sr3Ru2O7 (n = 2) phase was formed in a controlled manner near the film-substrate interface. This higher-order RP-phase then blocked the subsequent formation of OPBs, resulting in nearly defect-free Sr2RuO4 layer at the upper region of the film. Consequently, the Sr2RuO4 thin films exhibited superconductivity up to 1.15 K, which is the highest among Sr2RuO4 films grown by pulsed laser deposition. This work paves the way for synthesizing pristine RP-phase heterostructures and exploring their unique physical properties

In vitro inhibition of 10-formyltetrahydrofolate dehydrogenase activity by acetaldehyde

Alcoholism has been associated with folate deficiency in humans and laboratory animals. Previous study showed that ethanol feeding reduces the dehydrogenase and hydrolase activity of 10-formyltetrahydrofolate dehydrogenase (FDH) in rat liver. Hepatic ethanol metabolism generates acetaldehyde and acetate. The mechanisms by which ethanol and its metabolites produce toxicity within the liver cells are unknown. We purified FDH from rat liver and investigated the effect of ethanol, acetaldehyde and acetate on the enzyme in vitro. Hepatic FDH activity was not reduced by ethanol or acetate directly. However, acetaldehyde was observed to reduce the dehydrogenase activity of FDH in a dose- and time-dependent manner with an apparent IC50 of 4 mM, while the hydrolase activity of FDH was not affected by acetaldehyde in vitro. These results suggest that the inhibition of hepatic FDH dehydrogenase activity induced by acetadehyde may play a role in ethanol toxicity

Distinct Genetic Lineages of Bactrocera caudata (Insecta: Tephritidae) Revealed by COI and 16S DNA Sequences

The fruit fly Bactrocera caudata is a pest species of economic importance in Asia. Its larvae feed on the flowers of Cucurbitaceae such as Cucurbita moschata. To-date it is distinguished from related species based on morphological characters. Specimens of B. caudata from Peninsular Malaysia and Indonesia (Bali and Lombok) were analysed using the partial DNA sequences of cytochrome c oxidase subunit I (COI) and 16S rRNA genes. Both gene sequences revealed that B. caudata from Peninsular Malaysia was distinctly different from B. caudata of Bali and Lombok, without common haplotype between them. Phylogenetic analysis revealed two distinct clades, indicating distinct genetic lineage. The uncorrected ‘p’ distance for COI sequences between B. caudata of Malaysia-Thailand-China and B. caudata of Bali-Lombok was 5.65%, for 16S sequences from 2.76 to 2.99%, and for combined COI and 16S sequences 4.45 to 4.46%. The ‘p’ values are distinctly different from intraspecific ‘p’ distance (0–0.23%). Both the B. caudata lineages are distinctly separated from related species in the subgenus Zeugodacus – B. ascita, B. scutellata, B. ishigakiensis, B. diaphora, B. tau, B. cucurbitae, and B. depressa. Molecular phylogenetic analysis indicates that the B. caudata lineages are closely related to B. ascita sp. B, and form a clade with B. scutellata, B. ishigakiensis, B. diaphora and B. ascita sp. A. This study provides additional baseline for the phylogenetic relationships of Bactrocera fruit flies of the subgenus Zeugodacus. Both the COI and 16S genes could be useful markers for the molecular differentiation and phylogenetic analysis of tephritid fruit flies