Metal-induced isomerization yields an intracellular chelator that disrupts bacterial iron homeostasis.

The dwindling supply of antibiotics that remain effective against drug-resistant bacterial pathogens has precipitated efforts to identify new compounds that inhibit bacterial growth using untapped mechanisms of action. Here, we report both (1) a high-throughput screening methodology designed to discover chemical perturbants of the essential, yet unexploited, process of bacterial iron homeostasis, and (2) our findings from a small-molecule screen of more than 30,000 diverse small molecules that led to the identification and characterization of two spiro-indoline-thiadiazoles that disrupt iron homeostasis in bacteria. We show that these compounds are intracellular chelators with the capacity to exist in two isomeric states.

Development of a canine model with diffuse hepatic vein obstruction (Budd‑Chiari syndrome) via endovascular occlusion.

The aim of the present study was to develop a reliable and reproducible canine model to mimic human diffuse hepatic vein obstruction (Budd‑Chiari syndrome, BCS). A total of 24 canines were divided into an experimental (n=18) and a control (n=6) group. Under the guidance of digital subtraction angiography, a balloon catheter was delivered to the target hepatic vein (the common trunk of the left hepatic and middle hepatic veins) via the right external jugular vein.

Combining angioplasty with percutaneous microwave ablation for treating primary Budd-Chiari syndrome associated with hepatocellular carcinoma in two patients: A case report.

Percutaneous transluminal angioplasty using balloon catheters for Budd-Chiari syndrome (BCS) and transcatheter arterial chemoembolization (TACE) for unresectable hepatocellular carcinoma (HCC) have become increasingly accepted as alternative therapeutic modalities. However, few studies have investigated the clinical efficacy of combining percutaneous microwave ablation with angioplasty for patients with BCS complicated by HCC. In the present study, a safe and effective method for treating BCS associated with HCC is presented.

Catheter-directed thrombolytic therapy combined with angioplasty for hepatic vein obstruction in Budd-Chiari syndrome complicated by thrombosis.

The aim of this study was to assess the efficacy and safety of catheter-directed thrombolysis combined with angioplasty in the treatment of hepatic vein obstruction in Budd-Chiari syndrome (BCS) complicated by thrombosis. In 14 cases of BCS, the patients with hepatic vein obstruction complicated by thrombosis who underwent catheter-directed urokinase thrombolysis, balloon dilatation and/or stent placement were followed up with an ultrasound examination of the liver. Among the 13 cases of successful treatment, one hepatic vein was recanalized in 12 patients (right hepatic vein, seven cases; left hepatic vein, three cases; middle hepatic vein, one case and accessory hepatic vein, one case) and two hepatic veins (right and left) were recanalized in one patient without serious complications, such as bleeding and pulmonary embolism.

Combined use of hydration and alprostadil for preventing contrast-induced nephropathy following percutaneous coronary intervention in elderly patients.

Contrast-induced nephropathy (CIN) is a complex syndrome of acute kidney injury that follows exposure to intravascular contrast media. Although a series of preventive measures have been developed, CIN remains a major challenge encountered in elderly patients by interventional cardiologists. No data are currently available concerning the potential effects of the combined use of hydration and alprostadil in the prevention of CIN following percutaneous coronary intervention (PCI) in elderly patients.

Identifying producers of antibacterial compounds by screening for antibiotic resistance.

Microbially derived natural products are major sources of antibiotics and other medicines, but discovering new antibiotic scaffolds and increasing the chemical diversity of existing ones are formidable challenges. We have designed a screen to exploit the self-protection mechanism of antibiotic producers to enrich microbial libraries for producers of selected antibiotic scaffolds. Using resistance as a discriminating criterion we increased the discovery rate of producers of both glycopeptide and ansamycin antibacterial compounds by several orders of magnitude in comparison with historical hit rates.

Chemical variation from the neoantimycin depsipeptide assembly line.

Here we report the biosynthetic pathway for the neoantimycin and present three novel neoantimycin analogues, neoantimycin D (1), E (2) and F (3), from this assembly system from Streptoverticillium orinoci. Identification of these novel neoantimycin variants was achieved by selective MS/MS interrogation of natural product extracts using diagnostic fragments of the known neoantimycins. Their structures, including the absolute configurations, were elucidated using a combination of NMR experiments, detailed MS/MS experiments and the advanced Marfey's method.

Iron and citrate export by a major facilitator superfamily pump regulates metabolism and stress resistance in Salmonella Typhimurium.

The efficacy of antibiotics and host defenses has been linked to the metabolic and redox states of bacteria. In this study we report that a stress-induced export pump belonging to the major facilitator superfamily effluxes citrate and iron from the enteric pathogen Salmonella Typhimurium to arrest growth and ameliorate the effects of antibiotics, hydrogen peroxide, and nitric oxide. The transporter, formerly known as MdtD, is now designated IceT (iron citrate efflux transporter).

Macplocimine A, a new 18-membered macrolide isolated from the filamentous sulfur bacteria Thioploca sp.

Macplocimine A (1), a rare naturally occurring 18-membered macrolide, was isolated from the marine-derived filamentous sulfur bacteria Thioploca sp. The structure was determined by a combination of spectroscopic techniques, including HRESIMS, 1D and 2D NMR analyses. 1 features a thymine group, which is attached to an aromatic fused 18-membered macrolide ring structure derived from a polyketide synthase biosynthetic pathway.

The conversion of protonated cytosine-SO3(-) to uracil-SO3(-): insights into the novel induced hydrolytic deamination through bisulfite catalysis.

The induced ability of bisulfite to facilitate the hydrolytic deamination of the protonated cytosine-SO3(-) has been studied at the MP2/6-311++G(3df,3pd)//B3LYP/6-311++G(d,p) level and CBS-QB3 approach, respectively. In the gas phase, two distinct groups of mechanisms were explored, the direct hydrolytic deamination (path A) and HSO3(-)-induced hydrolytic deamination (paths B-D), and it indicates that the direct hydrolytic deamination of protonated cytosine-SO3(-) (path A) is unlikely because of the high activation free energy involved in the rate-limiting step, whereas the presence of bisulfite (paths B-D) significantly contributes to decreasing the activation free energy. In the aqueous phase, although the solvent effects of water significantly decrease the activation free energy of path A, the direct hydrolysis reaction remains unfavorable and the HSO3(-)-induced mechanism is still more favorable, which is in agreement with previous experimental data.

The comprehensive antibiotic resistance database.

The field of antibiotic drug discovery and the monitoring of new antibiotic resistance elements have yet to fully exploit the power of the genome revolution. Despite the fact that the first genomes sequenced of free living organisms were those of bacteria, there have been few specialized bioinformatic tools developed to mine the growing amount of genomic data associated with pathogens. In particular, there are few tools to study the genetics and genomics of antibiotic resistance and how it impacts bacterial populations, ecology, and the clinic.

Sequencing and automated whole-genome optical mapping of the genome of a domestic goat (Capra hircus).

We report the ∼2.66-Gb genome sequence of a female Yunnan black goat. The sequence was obtained by combining short-read sequencing data and optical mapping data from a high-throughput whole-genome mapping instrument.

Effects of protonation and C5 methylation on the electrophilic addition reaction of cytosine: a computational study.

The mechanism for the effects of protonation and C5 methylation on the electrophilic addition reaction of Cyt has been explored by means of CBS-QB3 and CBS-QB3/PCM methods. In the gas phase, three paths, two protonated paths (N3 and O2 protonated paths B and C) as well as one neutral path (path A), were mainly discussed, and the calculated results indicate that the reaction of the HSO(3)(-) group with neutral Cyt is unlikely because of its high activation free energy, whereas O2-protonated path (path C) is the most likely to occur. In the aqueous phase, path B is the most feasible mechanism to account for the fact that the activation free energy of path B decreases compared with the corresponding path in the gas phase, whereas those of paths A and C increase.

Screening natural antioxidants in peanut shell using DPPH-HPLC-DAD-TOF/MS methods.

Peanut shell, a byproduct in oil production, is rich in natural antioxidants. Here, a rapid and efficient method using DPPH-HPLC-DAD-TOF/MS was used for the first time to screen antioxidants in peanut shell. The method is based on the hypothesis that upon reaction with 1, 1-diphenyl-2-picrylhydrazyl (DPPH), the peak areas of compounds with potential antioxidant activities in the HPLC chromatogram will be significantly reduced or disappeared, and the identity confirmation could be achieved by HPLC-DAD-TOF/MS technique.

[Analysis of pyrolysis process and gas evolution rule of larch wood by TG-FTIR].

The weight-loss character and gas evolution rule of larch wood at different heating rates were investigated by TG-FTIR (thermogravimetric analyzer coupled to a Fourier transform infrared spectrometer), and the results were compared with those of larch wood model-component mixture. The main weight-loss area of larch wood was wider than larch wood model-component mixture, and the residual char yield of larch wood (18.97%) was lower than larch wood model-component mixture (29.

Genome sequence of foxtail millet (Setaria italica) provides insights into grass evolution and biofuel potential.

Foxtail millet (Setaria italica), a member of the Poaceae grass family, is an important food and fodder crop in arid regions and has potential for use as a C(4) biofuel. It is a model system for other biofuel grasses, including switchgrass and pearl millet. We produced a draft genome (∼423 Mb) anchored onto nine chromosomes and annotated 38,801 genes.

Theoretical study on the mechanism and kinetics for the self-reaction of C2H5O2 radicals.

Oxygen-to-oxygen coupling, direct H-abstraction and oxygen-to-(α)carbon nucleophilic substitution processes have been investigated for both the singlet and triplet self-reaction of C(2)H(5)O(2) radicals at the CCSD(T)/cc-pVDZ//B3LYP/6-311G(2d,2p) level to evaluate the reaction mechanisms, possible products and rate constants. The calculated results show that the title reaction mainly occurs through the singlet oxygen-to-oxygen coupling mechanism with the formation of entrance tetroxide intermediates, and the most dominant product is C(2)H(5)O + HO(2) + CH(3)CHO (P5) generated in channel R5. Beginning from the radical products of P5 (C(2)H(5)O, HO(2)) and reactant (C(2)H(5)O(2)), five secondary reactions HO(2) + HO(2) (a), HO(2) + C(2)H(5)O (b), C(2)H(5)O + C(2)H(5)O (c), HO(2) + C(2)H(5)O(2) (d), and C(2)H(5)O + C(2)H(5)O(2) (e) mainly proceed on the triplet potential energy surface.

[Longitudinal observation on schistosomiasis control effect of human-cattle synchronous chemotherapy].

The annual reports of human-cattle synchronous chemotherapy from 1992 to 2008 were collected and analyzed, and its effect on schistosomiasis control was evaluated. The results showed that human and cattle infection rates decreased by 72.37% (chi2 = 9.

Water-catalyzed gas-phase hydrogen abstraction reactions of CH3O2 and HO2 with HO2: a computational investigation.

The gas-phase hydrogen abstraction reactions of CH(3)O(2) and HO(2) with HO(2) in the presence and absence of a single water molecule have been studied at the CCSD(T)/6-311++G(3d,2p)//B3LYP/6-311G(2d,2p) level of theory. The calculated results show that the process for O(3) formation is much faster than that for (1)O(2) and (3)O(2) formation in the water-catalyzed CH(3)O(2) + HO(2) reaction. This is different from the results for the non-catalytic reaction of CH(3)O(2) + HO(2), in which almost only the process for (3)O(2) formation takes place.

The genomic sequence of the Chinese hamster ovary (CHO)-K1 cell line.

Chinese hamster ovary (CHO)-derived cell lines are the preferred host cells for the production of therapeutic proteins. Here we present a draft genomic sequence of the CHO-K1 ancestral cell line. The assembly comprises 2.

Photochemical stabilization of terthiophene and its utilization as a new sensing element in the fabrication of monolayer-chemistry-based fluorescent sensing films.

To improve the photochemical stability of α-terthiophene (3T) in air, we purposely introduced a naphthalene unit into its conjugated backbone, resulting in a fluorescent compound, 5-(1-naphthyl)-2,2':5',2''-terthiophene (NA-3T). The compound was further employed as a sensing element for the fabrication of a monolayer-chemistry based fluorescent sensing film. It was demonstrated that the fabricated film is highly sensitive and selective to the presence of picric acid (PA).

Lactobacillus reuteri-produced cyclic dipeptides quench agr-mediated expression of toxic shock syndrome toxin-1 in staphylococci.

The production of the staphylococcal exotoxin toxic shock syndrome toxin-1 (TSST-1) by Staphylococcus aureus has been associated with essentially all cases of menstruation-associated toxic shock syndrome (TSS). In this work, we show that the human vaginal isolate Lactobacillus reuteri RC-14 produces small signaling molecules that are able to interfere with the staphylococcal quorum-sensing system agr, a key regulator of virulence genes, and repress the expression of TSST-1 in S. aureus MN8, a prototype of menstrual TSS S.

Effect of diacylglycerol supplementation on fasting serum triacylglycerol concentration: a meta-analysis.

Diacylglycerol (DAG) supplementation has been shown to be associated with the reduction of fasting serum triacylglycerol (TAG) concentration, although the extent of the association is uncertain. We quantitatively examined the effect of dietary DAG on fasting serum TAG concentration by conducting a meta-analysis of randomized controlled trials. Potential papers were searched from electronic databases of Medline, Embase and Cochrane Library.

Staphylococcus aureus nonribosomal peptide secondary metabolites regulate virulence.

Staphylococcus aureus is a major human pathogen that is resistant to numerous antibiotics in clinical use. We found two nonribosomal peptide secondary metabolites--the aureusimines, made by S. aureus--that are not antibiotics, but function as regulators of virulence factor expression and are necessary for productive infections.