Mutations in the waaR gene of Escherichia coli which disrupt lipopolysaccharide outer core biosynthesis affect cell surface retention of group 2 capsular polysaccharides

On the basis of increased resistance to K5 capsule-specific bacteriophage, a waaR transposon mutant defective in the biosynthesis of lipopolysaccharide outer core was isolated. In a K1-expressing strain the mutation equally affected sensitivity to K1 capsule-specific bacteriophage, indicating a general effect on group 2 capsules. The waaR mutation affected retention on the cell surface of the K5 polysaccharide, with increased polysaccharide accumulating in the culture supernatant. This indicates that interactions between the outer core of lipopolysaccharide and group 2 capsular polysaccharides are important for the stabilization of group 2 capsular polysaccharides on the cell surface.     

Uncoupled redox systems in the lumen of the endoplasmic reticulum. Pyridine nucleotides stay reduced in an oxidative environment

The redox state of the intraluminal pyridine nucleotide pool was investigated in rat liver microsomal vesicles. The vesicles showed cortisone reductase activity in the absence of added reductants, which was dependent on the integrity of the membrane. The intraluminal pyridine nucleotide pool could be oxidized by the addition of cortisone or metyrapone but not of glutathione. On the other hand, intraluminal pyridine nucleotides were slightly reduced by cortisol or glucose 6-phosphate, although glutathione was completely ineffective. Redox state of microsomal protein thiols/disulfides was not altered either by manipulations affecting the redox state of pyridine nucleotides or by the addition of NAD(P)+ or NAD(P)H. The uncoupling of the thiol/disulfide and NAD(P)+/NAD(P)H redox couples was not because of their subcompartmentation, because enzymes responsible for the intraluminal oxidoreduction of pyridine nucleotides were distributed equally in smooth and rough microsomal subfractions. Instead, the phenomenon can be explained by the negligible representation of glutathione reductase in the endoplasmic reticulum lumen. The results demonstrated the separate existence of two redox systems in the endoplasmic reticulum lumen, which explains the contemporary functioning of oxidative folding and of powerful reductive reactions.     

Nitrogen Control of Atrazine Utilization in Pseudomonas sp. Strain ADP

Pseudomonas sp. strain ADP uses the herbicide atrazine as the sole nitrogen source. We have devised a simple atrazine degradation assay to determine the effect of other nitrogen sources on the atrazine degradation pathway. The atrazine degradation rate was greatly decreased in cells grown on nitrogen sources that support rapid growth of Pseudomonas sp. strain ADP compared to cells cultivated on growth-limiting nitrogen sources. The presence of atrazine in addition to the nitrogen sources did not stimulate degradation. High degradation rates obtained in the presence of ammonium plus the glutamine synthetase inhibitor MSX and also with an Nas⁻ mutant derivative grown on nitrate suggest that nitrogen regulation operates by sensing intracellular levels of some key nitrogen-containing metabolite. Nitrate amendment in soil microcosms resulted in decreased atrazine mineralization by the wild-type strain but not by the Nas⁻ mutant. This suggests that, although nitrogen repression of the atrazine catabolic pathway may have a strong impact on atrazine biodegradation in nitrogen-fertilized soils, the use of selected mutant variants may contribute to overcoming this limitation.     

Small-molecule CB002 restores p53 pathway signaling and represses colorectal cancer cell growth

Much effort is currently focused on the p53 pathway. p53 is a key tumor suppressor, which is mutated or lost in many human cancers. Restoration of the p53 pathway holds the potential to induce selective cell death in tumor cells without harming normal cells that have intact p53 pathways. Most tumor cells express mutated p53 or suppress p53 by overexpression of MDM2. In this study, a compound referred to as CB002 with one closely related compound from the Chembridge library were evaluated for tumor cytotoxicity without affecting normal cells by restoration of the p53 pathway. A decrease of mutant p53 protein expression, restoration of inactivated p53, or some activation of p73 are candidate mechanisms this agent could cause tumor cell apoptosis and growth arrest. We further show that CB002 activates p53 pathway signaling in part via p73 in p53 mutant cancer cell lines. However, it is important to note that we have not established a role for p73 in the anti-tumor effect of CB002 or R1. CB002 causes tumor cell death with synergistic effects with traditional chemotherapeutics CPT-11 and 5-FU.     

Courtship and Mating Behavior of the Cockroach <Emphasis Type="Italic">Oxyhaloa deusta</Emphasis> [Thunberg, 1784] (Blaberidae,Oxyhaloinae): Attraction Bioassays and Morphology of the Pheromone Sources

In this paper, we focus on the reproductive behavior of the cockroach Oxyhaloa deusta. Within the Oxyhaloinae subfamily, mating strategies and glandular areas involved in pheromone production have been studied for several genera belonging to the Nauphoetini and Gromphadorhini tribes. However, this is the first time that courtship and mating behavior have been explored within the genus Oxyhaloa, and in a more general way within the Oxyhaloini tribe. This work, comprising behavioral observations, olfactometric bio-assays and morphological data, highlights unusual behaviors and novelties in potential sex pheromone gland location, in both males (tergite 8) and females (supra-valvular area). Surprisingly, our results also indicate that mate finding is initiated by the female. This is quite remarkable inasmuch as the Oxyhaloinae subfamily is the only cockroach group in which males initiate mate finding by means of a sex pheromone, emitted during the calling posture by extending abdominal tergites. In the Oxyhaloinae subfamily, this occurrence of various reproductive behavioral patterns (including all the mating patterns known at present in Blattaria) in closely-related species is striking, and makes this group a suitable model for studying the changes in mating behavior correlated with the location of sexual glands.     

Underground organs of Brazilian Asteraceae: testing the CLO-PLA database traits

Not all plant traits from all regions have been standardized or databased. Some ecosystems, such as tropical grasslands, are under-represented in such databases owing to the difficulty in assessing bud banks and evaluating clonal growth. This study aimed to (i) determine whether Brazilian morphological traits of belowground organs can be translated into categories used in the CLO-PLA database and (ii) assess the applicability of clonal and bud bank traits standardized in the CLO-PLA database for Brazilian Aldama species, which have specialized belowground organs and are able to resprout. In all, 165 species, including herbs, subshrubs and shrubs, of 37 genera from different Brazilian ecosystems, were evaluated. Not all the traditional Brazilian morphological categories could be translated into CLO-PLA traits, resulting in a lower number of categories and loss of information regarding plant morphology. Furthermore, clonal and bud bank traits could be only partially evaluated for Aldama, since some traits showed seasonal variation. The CLO-PLA classification focused on the organs in relation to the soil surface, the connection between mother and daughter shoots, and the origin of buds from which daughter shoots sprout. In the Brazilian classification, by contrast, anatomical features or early ontogeny of the organ are very important. Nevertheless, our results might form the basis for future comparative studies across ecosystems and biomes, for which common trait standardization is necessary. However, further research is needed to assess the functional morphology of clonal and bud bank traits in tropical regions.     

Exploring the biodiversity of two groups of Oenococcus oeni isolated from grape musts and wines: Are they equally diverse?

One hundred and four Oenococcus oeni isolates were characterised by the carbohydrate fermentation (CH) profile and DNA fingerprinting. Forty-four isolates came from grape must, and 60 from wines sampled at the end of alcoholic fermentation or during malolactic fermentation. The grape must isolates fermented more CH than the wine isolates. In genotypical terms, no clear boundary between grape must and wine isolates was found. Diversities were deduced by considering the isolates of grape must and of wine separately and jointly. By considering only CH fermentation abilities, the group of grape must isolates gave higher diversity index (DI_CH) values than those isolated from wine; i.e., these isolates were metabolically more diverse. The contrary occurred when the DNA fingerprints were used to calculate DI_RAPD-VNTR: wine isolates were genotypically more diverse than grape must ones. With a polyphasic approach, which considered metabolic and genotypic data, the diversity index of both isolate groups (from grape must and wine) was the same, 0.993, which was slightly lower than that calculated from all the isolates (0.997).     

Fully automated point-of-care differential diagnosis of acute febrile illness

BackgroundIn this work, a platform was developed and tested to allow to detect a variety of candidate viral, bacterial and parasitic pathogens, for acute fever of unknown origin. The platform is based on a centrifugal microfluidic cartridge, the LabDisk (“FeverDisk” for the specific application), which integrates all necessary reagents for sample-to-answer analysis and is processed by a compact, point-of-care compatible device.Methodology/Principal findingsA sample volume of 200 μL per FeverDisk was used. In situ extraction with pre-stored reagents was achieved by bind-wash-elute chemistry and magnetic particles. Enzymes for the loop-mediated isothermal amplification (LAMP) were pre-stored in lyopellet form providing stability and independence from the cold chain. The total time to result from sample inlet to read out was 2 h. The proof-of-principle was demonstrated in three small-scale feasibility studies: in Dakar, Senegal and Khartoum, Sudan we tested biobanked samples using 29 and 9 disks, respectively; in Reinfeld, Germany we tested spiked samples and analyzed the limit of detection using three bacteria simultaneously spiked in whole blood using 15 disks. Overall during the three studies, the FeverDisk detected dengue virus (different serotypes), chikungunya virus, Plasmodium falciparum, Salmonella enterica Typhi, Salmonella enterica Paratyphi A and Streptococcus pneumoniae.Conclusions/SignificanceThe FeverDisk proved to be universally applicable as it successfully detected all different types of pathogens as single or co-infections, while it also managed to define the serotype of un-serotyped dengue samples. Thirty-eight FeverDisks at the two African sites provided 59 assay results, out of which 51 (86.4%) were confirmed with reference assay results. The results provide a promising outlook for future implementation of the platform in larger prospective clinical studies for defining its clinical sensitivity and specificity. The technology aims to provide multi-target diagnosis of the origins of fever, which will help fight lethal diseases and the incessant rise of antimicrobial resistance.