The effects of probiotics on PPI-triple therapy for Helicobacter pylori eradication

Background: This study was performed to evaluate whether the addition of probiotics to proton pump inhibitor (PPI)‐based triple therapy increases the likelihood of successful Helicobacter pylori eradication. Materials and Methods: Three hundred and forty‐seven H. pylori‐infected patients were randomized into a triple‐plus‐yogurt group (yogurt group, n = 168) or a triple‐only group (control group, n = 179). Triple therapy consisted of PPI b.i.d., clarithromycin 500 mg b.i.d., and amoxicillin 1 g b.i.d. for 7 days. Yogurt group received triple therapy for 1 week and one bottle of Will yogurt per day for at 3 weeks, starting on the first day of triple therapy. Will yogurt (a Korean brand) contains Lactobacillus acidophilus HY2177, Lactobacillus casei HY2743, Bifidobacterium longum HY8001, and Streptococcus thermophilus B‐1. ¹³C‐urea breath test was performed at least 4 weeks after completion of triple therapy. Eradication rates, compliances, and adverse events were compared. Results: By intention‐to treat analysis the H. pylori eradication rates in the yogurt group 79.2% (133 of 168) was similar to that in the control group 72.1% (129 of 179) (p = .124). However, by per‐protocol (PP) analysis, the eradication rate in the yogurt group, 87.5% (133 of 152) was higher than that in the control group, 78.7% (129 of 164) (p = .037). Common adverse events were metallic taste (11.8%) and diarrhea (8.6%). The frequency of adverse effects in the yogurt group 41.1% (69/168) were higher than in the control group, 26.3% (47 of 179) (p = .003). However, most adverse events were mild to moderate in intensity, and the severities of adverse effects were similar in both groups (p = .401). Conclusions: The addition of Will yogurt to triple therapy did not reduce the side‐effects of triple therapy. But it increased the H. pylori eradication rate by PP analysis, encouraging more research in this field.     

Ubiquitination of mammalian Pex5p, the peroxisomal import receptor

Protein translocation across the peroxisomal membrane requires the concerted action of numerous peroxins. One central component of this machinery is Pex5p, the cycling receptor for matrix proteins. Pex5p recognizes newly synthesized proteins in the cytosol and promotes their translocation across the peroxisomal membrane. After this translocation step, Pex5p is recycled back into the cytosol to start a new protein transport cycle. Here, we show that mammalian Pex5p is ubiquitinated at the peroxisomal membrane. Two different types of ubiquitination were detected, one of which is thiol-sensitive, involves Cys(11) of Pex5p, and is necessary for the export of the receptor back into the cytosol. Together with mechanistic data recently described for yeast Pex5p, these findings provide strong evidence for the existence of Pex4p- and Pex22p-like proteins in mammals.     

Three new species of Croton (Euphorbiaceae s.s.) from the Brazilian Caatinga

While conducting a floristic inventory of Croton from the Brazilian Caatinga, three new species were discovered. Croton arenosus, Croton glandulosobracteatus, and Croton harleyi are described and illustrated here. Based on morphological characters, Croton glandulosobracteatus is proposed to belong to section Barhamia, and C. arenosus and C. harleyi to section Geiseleria.     

Soybean oil-degrading bacterial cultures as a potential for control of green peach aphids (Myzus persicae)

Microorganisms capable of degrading crude oil were isolated and grown in soybean oil as a sole carbon source. The microbial cultures were used to control green peach aphids in vitro. Approximately 60% mortality of aphids was observed when the cultures were applied alone onto aphids. To examine the cultures as a pesticide formulation mixture, the cultures were combined with a low dose of the insecticide imidacloprid (one-fourth dose of recommended field-application rate) and applied onto aphids. The cultures enhanced significantly the insecticidal effectiveness of imidacloprid, which was higher than imidacloprid alone applied at the low dose. The isolated microorganisms exhibited high emulsifying index values and decreased surface tension values after being grown in soybean oil media. GC/MS analyses showed that microorganisms degraded soybean oil to fatty acids. The cultures were suggested to play the roles of wetting, spreading, and sticking agents to improve the effectiveness of imidacloprid. This is the first report on the control of aphids by using oil-degrading microbial cultures.     

Differences in clinical features according to Boryoung and Karp genotypes of Orientia tsutsugamushi

Background

Scrub typhus is an infectious disease caused by Orientia tsutsugamushi. The differences in virulence of O. tsutsugamushi prototypes in humans are still unknown. We investigated whether there are any differences in the clinical features of the Boryoung and Karp genotypes.

Methodology/Principal Findings

Patients infected with O. tsutsugamushi, as Boryoung and Karp clusters, who had visited 6 different hospitals in southwestern Korea were prospectively compared for clinical features, complications, laboratory parameters, and treatment responses. Infected patients in the Boryoung cluster had significantly more generalized weakness, eschars, skin rashes, conjunctival injection, high albumin levels, and greater ESR and fibrinogen levels compared to the Karp cluster. The treatment response to current antibiotics was significantly slower in the Karp cluster as compared to the Boryoung cluster.

Conclusion

The frequency of occurrence of eschars and rashes may depend on the genotype of O. tsutsugamushi.     

Biochemical characterization of RssA-RssB, a two-component signal transduction system regulating swarming behavior in Serratia marcescens

Our previous study had identified a pair of potential two-component signal transduction proteins, RssA-RssB, involved in the regulation of Serratia marcescens swarming. When mutated, both rssA and rssB mutants showed precocious swarming phenotypes on LB swarming agar, whereby swarming not only occurred at 37 degrees C but also initiated on a surface of higher agar concentration and more rapidly than did the parent strain at 30 degrees C. In this study, we further show that the predicted sensor kinase RssA and the response regulator RssB bear characteristics of components of the phosphorelay signaling system. In vitro phosphorylation and site-directed mutagenesis assays showed that phosphorylated RssA transfers the phosphate group to RssB and that histidine 248 and aspartate 51 are essential amino acid residues involved in the phosphotransfer reactions in RssA and RssB, respectively. Accordingly, while wild-type rssA could, the mutated rssA(H248A) in trans could not complement the precocious swarming phenotype of the rssA mutant. Although RssA-RssB regulates expressions of shlA and ygfF of S. marcescens (ygfF(Sm)), in vitro DNA-binding assays showed that the phosphorylated RssB did not bind directly to the promoter regions of these two genes but bound to its own rssB promoter. Subsequent assays located the RssB binding site within a 63-bp rssB promoter DNA region and confirmed a direct negative autoregulation of the RssA-RssB signaling pathway. These results suggest that when activated, RssA-RssB acts as a negative regulator for controlling the initiation of S. marcescens swarming.     

Formation of elongated giant mitochondria in DFO-induced cellular senescence: involvement of enhanced fusion process through modulation of Fis1

Enlarged or giant mitochondria have often been documented in aged tissues although their role and underlying mechanism remain unclear. We report here how highly elongated giant mitochondria are formed in and related to the senescent arrest. The mitochondrial morphology was progressively changed to a highly elongated form during deferoxamine (DFO)-induced senescent arrest of Chang cells, accompanied by increase of intracellular ROS level and decrease of mtDNA content. Interestingly, under exposure to subcytotoxic doses of H2O2 (200 microM), about 65% of Chang cells harbored elongated mitochondria with senescent phenotypes whereas ethidium bromide (EtBr) (50 ng/ml) only reformed the cristae structure. Elongated giant mitochondria were also observed in TGF beta1- or H2O2-induced senescent Mv1Lu cells and in old human diploid fibroblasts (HDFs). In all senescent progresses employed in this study Fis1 protein, a mitochondrial fission modulator, was commonly downexpressed. Overexpression of YFP-Fis1 reversed both mitochondrial elongation and appearance of senescent phenotypes induced by DFO, implying its critical involvement in the arrest. Finally, we found that direct induction of mitochondrial elongation by blocking mitochondrial fission process with Fis1-DeltaTM or Drp1-K38A was sufficient to develop senescent phenotypes with increased ROS production. These data suggest that mitochondrial elongation may play an important role as a mediator in stress-induced premature senescence.     

Cancer Cell Analyses at the Single Cell-Level Using Electroactive Microwell Array Device

Circulating tumor cells (CTCs), shed from primary tumors and disseminated into peripheral blood, are playing a major role in metastasis. Even after isolation of CTCs from blood, the target cells are mixed with a population of other cell types. Here, we propose a new method for analyses of cell mixture at the single-cell level using a microfluidic device that contains arrayed electroactive microwells. Dielectrophoretic (DEP) force, induced by the electrodes patterned on the bottom surface of the microwells, allows efficient trapping and stable positioning of single cells for high-throughput biochemical analyses. We demonstrated that various on-chip analyses including immunostaining, viability/apoptosis assay and fluorescent in situ hybridization (FISH) at the single-cell level could be conducted just by applying specific reagents for each assay. Our simple method should greatly help discrimination and analysis of rare cancer cells among a population of blood cells.     

Enhancement of the Efficiency of Secretion of Heterologous Lipase in Escherichia coli by Directed Evolution of the ABC Transporter System

The ABC transporter (TliDEF) from Pseudomonas fluorescens SIK W1, which mediated the secretion of a thermostable lipase (TliA) into the extracellular space in Escherichia coli, was engineered using directed evolution (error-prone PCR) to improve its secretion efficiency. TliD mutants with increased secretion efficiency were identified by coexpressing the mutated tliD library with the wild-type tliA lipase in E. coli and by screening the library with a tributyrin-emulsified indicator plate assay and a microtiter plate-based assay. Four selected mutants from one round of error-prone PCR mutagenesis, T6, T8, T24, and T35, showed 3.2-, 2.6-, 2.9-, and 3.0-fold increases in the level of secretion of TliA lipase, respectively, but had almost the same level of expression of TliD in the membrane as the strain with the wild-type TliDEF transporter. These results indicated that the improved secretion of TliA lipase was mediated by the transporter mutations. Each mutant had a single amino acid change in the predicted cytoplasmic regions in the membrane domain of TliD, implying that the corresponding region of TliD was important for the improved and successful secretion of the target protein. We therefore concluded that the efficiency of secretion of a heterologous protein in E. coli can be enhanced by in vitro engineering of the ABC transporter.     

Acentriolar microtubule organization centers and Ran‐mediated microtubule formation pathways are both required in porcine oocytes

Mammalian oocytes lack centrioles but can generate bipolar spindles using several different mechanisms. For example, mouse oocytes have acentriolar microtubule organization centers (MTOCs) that contain many components of the centrosome, and which initiate microtubule polymerization. On the contrary, human oocytes lack MTOCs and the Ran‐mediated mechanisms may be responsible for spindle assembly. Complete knowledge of the different mechanisms of spindle assembly is lacking in various mammalian oocytes. In this study, we demonstrate that both MTOC‐ and Ran‐mediated microtubule nucleation are required for functional meiotic metaphase I spindle generation in porcine oocytes. Acentriolar MTOC components, including Cep192 and pericentrin, were absent in the germinal vesicle and germinal vesicle breakdown stages. However, they start to colocalize to the spindle microtubules, but are absent in the meiotic spindle poles. Knockdown of Cep192 or inhibition of Polo‐like kinase 1 activity impaired the recruitment of Cep192 and pericentrin to the spindles, impaired microtubule assembly, and decreased the polar body extrusion rate. When the Ran^GTP gradient was perturbed by the expression of dominant negative or constitutively active Ran mutants, severe defects in microtubule nucleation and cytokinesis were observed, and the localization of MTOC materials in the spindles was abolished. These results demonstrate that the stepwise involvement of MTOC‐ and Ran‐mediated microtubule assembly is crucial for the formation of meiotic spindles in porcine oocytes, indicating the diversity of spindle formation mechanisms among mammalian oocytes.