A Novel Virulence Gene in Klebsiella pneumoniae Strains Causing Primary Liver Abscess and Septic Metastatic Complications

Primary Klebsiella pneumoniae liver abscess complicated with metastatic meningitis or endophthalmitis is a globally emerging infectious disease. Its pathogenic mechanism remains unclear. The bacterial virulence factors were explored by comparing clinical isolates. Differences in mucoviscosity were observed between strains that caused primary liver abscess (invasive) and those that did not (noninvasive). Hypermucoviscosity correlated with a high serum resistance and was more prevalent in invasive strains (52/53 vs. 9/52; P < 0.0001). Transposon mutagenesis identified candidate virulence genes. A novel 1.2-kb locus, magA, which encoded a 43-kD outer membrane protein, was significantly more prevalent in invasive strains (52/53 vs. 14/52; P < 0.0001). The wild-type strain produced a mucoviscous exopolysaccharide web, actively proliferated in nonimmune human serum, resisted phagocytosis, and caused liver microabscess and meningitis in mice. However, magA− mutants lost the exopolysaccharide web and became extremely serum sensitive, phagocytosis susceptible, and avirulent to mice. Virulence was restored by complementation using a magA-containing plasmid. We conclude that magA fits molecular Koch's postulates as a virulence gene. Thus, this locus can be used as a marker for the rapid diagnosis and for tracing the source of this emerging infectious disease

Applying Cytogenetics in Phylogenetic Studies

Cytogenetics, with its fundamental role in the field of genetic investigation, continues to be an indispensable tool for studying phylogenetics, given that currently molecular evolutionary analyses are more commonly utilized. Chromosomal evolution indicated that genomic evolution occurs at the level of chromosomal segments, namely, the genomic blocks in the size of Mb‐level. The recombination of homologous blocks, through the mechanisms of insertion, translocation, inversion, and breakage, has been proven to be a major mechanism of speciation and subspecies differentiation. Meanwhile, molecular cytogenetics (fluorescence in situ hybridization‐based methodologies) had been already widely applied in studying plant genetics since polyploidy is common in plant evolution and speciation. It is now recognized that comparative cytogenetic studies can be used to explore the plausible phylogenetic relationships of the extant mammalian species by reconstructing the ancestral karyotypes of certain lineages. Therefore, cytogenetics remains a feasible tool in the study of comparative genomics, even in this next generation sequencing (NGS) prevalent era

Species and sex comparisons of karyotype and genome size in two <em>Kurixalus tree</em> frogs (Anura, Rhacophoridae)

Kurixalus is a rhacophorid genus of tree frogs that are similar in morphology but vary in reproductive behavior. We investigated the cytogenetic features and genome size using conventional G-banding, C-banding and silver-staining techniques, fluorescence in situ hybridization (FISH), and flow cytometry in two representatives of Kurixalus (K. eiffingeri Boettger, 1895 and K. idiootocus Kuramoto and Wang, 1987) and compared the data between species and sex. The two Kurixalus species share a diploid chromosome number 2n = 26 and fundamental number FN = 52. Prominent differences between species were noted in the distribution of secondary constriction (SC)/nucleolus organizer region (NOR) and dense heterochromatin. Other interspecies differences including variations in the number of metacentric and submetacentric chromosomes and staining intensity of heterochromatin were also found. The cytogenetic results are consistent with the observed differences in their genome sizes. FISH with telomeric motif (TTAGGG)n for both species detected signals in the terminal regions. Intersex comparisons revealed no differences in terms of cytogenetic features and genome size in the two species. Despite the apparent highly conserved diploid chromosome number, data on the karyotype microstructure characterize the cytogenetic profile of the two Kurixalus species that contribute to clarification of the chromosomal homologies and the rearrangement mechanisms occurring during the karyotype evolution of Kurixalus. No heteromorphic chromosome pair in both species is consistent with the view that homomorphic sex chromosome is common in amphibians

Discovery of a new species of the subgenus Japonigekko (Squamata, Gekkonidae, Gekko) from the Hengduan Mountains, southwestern China: the best Japonigekko mountaineer

A new Gekko (subgenus Japonigekko) species, Gekko alpinus sp. nov., is described from the Jinsha River Basin in southwestern China, between the border of Mangkang County, Xizang Autonomous Region and Batang County, Sichuan Province, according to the integrative taxonomic results combining molecular data and morphological characters obtained from the type series comprising 11 specimens. Our molecular phylogeny inferred from the mitochondrial 16S and ND2 gene fragments indicated that this new species is most closely related to Gekko jinjiangensis, but a considerable amount of genetic divergence exists between them (p-distance: 3.6%-4.1% (16S) and 7.1%–9.1% (ND2)). The new species can be distinguished from its congeners via a combination of series morphological characters. The discovery of this new species marks the highest altitudinal range (2400 to 2542 m a.s.l.) recorded for the subgenus Japonigekko and also represents a new provincial record for the genus in Xizang Autonomous Region

MiR-181b sensitizes glioma cells to teniposide by targeting MDM2

Background: Although the incidence of glioma is relatively low, it is the most malignant tumor of the central nervous system. The prognosis of high-grade glioma patient is very poor due to the difficulties in complete resection and resistance to radio-/chemotherapy. Therefore, it is worth investigating the molecular mechanisms involved in glioma drug resistance. MicroRNAs have been found to play important roles in tumor progression and drug resistance. Our previous work showed that miR-181b is involved in the regulation of temozolomide resistance. In the current study, we investigated whether miR-181b also plays a role in antagonizing the effect of teniposide.Methods: MiR-181b expression was measured in 90 glioma patient tissues and its relationship to prognosis of these patients was analyzed. Cell sensitivity to teniposide was tested in 48 primary cultured glioma samples. Then miR-181b stably overexpressed U87 cells were generated. The candidate genes of miR-181b from our previous study were reanalyzed, and the interaction between miR-181b and target gene MDM2 was confirmed by dual luciferase assay. Cell sensitivity to teniposide was detected on miR-181b over expressed and MDM2 down regulated cells.Results: Our data confirmed the low expression levels of miR-181b in high-grade glioma tissues, which is related to teniposide resistance in primary cultured glioma cells. Overexpression of miR-181b increased glioma cell sensitivity to teniposide. Through target gene prediction, we found that MDM2 is a candidate target of miR-181b. MDM2 knockdown mimicked the sensitization effect of miR-181b. Further study revealed that miR-181b binds to the 3'-UTR region of MDM2 leading to the decrease in MDM2 levels and subsequent increase in teniposide sensitivity. Partial restoration of MDM2 attenuated the sensitivity enhancement by miR-181b.Conclusions: MiR-181b is an important positive regulator on glioma cell sensitivity to teniposide. It confers glioma cell sensitivity to teniposide through binding to the 3'-UTR region of MDM2 leading to its reduced expression. Our findings not only reveal the novel mechanism involved in teniposide resistance, but also shed light on the optimization of glioma treatment in the future.Department of Health Technology and Informatic

Sputter-prepared (001) BiFeO3 thin films with ferromagnetic L10-FePt(001) electrode on glass substrates

Highly textured BiFeO(3)(001) films were formed on L1(0)-FePt(001) bottom electrodes on glass substrates by sputtering at reduced temperature of 400°C. Good electric polarization 2P(r) = 80 and 95 μC/cm(2), comparable to that of the reported epitaxial films, and coercivity E(c) = 415 and 435 kV/cm are achieved in the samples with 20-nm- and 30-nm-thick electrodes. The BiFeO(3)(001) films show different degrees of compressive strain. The relation between the variations of strain and 2P(r) suggests that the enhancement of 2P(r) resulted from the strain-induced rotation of spontaneous polarization. The presented results open possibilities for the applications based on electric-magnetic interactions

Predictors of betel quid chewing behavior and cessation patterns in Taiwan aborigines

BACKGROUND: Betel quid, chewed by about 600 million people worldwide, is one of the most widely used addictive substances. Cessation factors in betel quid chewers are unknown. The present study explores prevalence and the quit rate of betel quid chewing in Taiwan aborigines. Our goal was to delineate potential predictors of chewing cessation. METHODS: A stratified random community-based survey was designed for the entire aborigines communities in Taiwan. A total of 7144 participants were included between June 2003 and May 2004 in this study. Information on sociodemographic characteristics, such as gender, age, obesity, education years, marital status, ethnicity, and habits of betel quid chewing, smoking and drinking was collected by trained interviewers. RESULTS: The prevalence of betel quid chewers was 46.1%. Betel quid chewing was closely associated with obesity (OR = 1.61; 95% CI: 1.40–1.85). Betel quid chewers were most likely to use alcohol and cigarettes together. Quit rate of betel quid chewers was 7.6%. Betel quid chewers who did not drink alcohol were more likely to quit (OR = 1.89; 95% CI: 1.43–2.50). Alcohol use is a significant factor related to cessation of betel quid chewing, but smoking is not. CONCLUSION: Taiwan aborigines have a high prevalence of betel quid chewers and a low quit rate. Alcohol use is strongly association with betel quid chewing. Efforts to reduce habitual alcohol consumption might be of benefit in cessation of betel quid chewing

A double-blind, randomized phase II study of dicycloplatin plus paclitaxel versus carboplatin plus paclitaxel as first-line therapy for patients with advanced non-small-cell lung cancers

Introduction: The aim of this study was to compare the efficacy and toxicity of dicycloplatin plus paclitaxel with those of carboplatin plus paclitaxel as first-line treatment for patients with advanced non-small-cell lung cancer (NSCLC). Material and methods: In this study, 240 NSCLC patients with stage IIIB (with pleural effusion) and stage IV disease were randomly assigned (1: 1) to receive dicycloplatin 450 mg/m(2) or carboplatin AUC = 5, in combination with paclitaxel 175 mg/m2 (D + P or C + P) every 3 weeks for up to 4 to 6 cycles. The primary endpoint was response rate. Secondary endpoints included progression-free survival (PFS), overall survival (OS) and adverse events. Results: The response rates for the D + P and C + P arm were 36.44% and 30.51%, respectively (p = 0.33). The median PFS was 5.6 months in the D + P arm and 4.7 months in the C + P arm (p = 0.31). The median OS was 14.9 months for D + P and 12.9 months for C + P (p = 0.37). Adverse events in the two arms were well balanced. The most common grade 3/4 adverse event was hematologic toxicity. Conclusions: Patients treated with D + P had similar response and survival rates to those treated with C + P, and toxicities of both treatments were generally tolerable.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000341274400012&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Medicine, General &amp; InternalSCI(E)[email protected]

Genome-Wide Gene Expression Analysis Implicates the Immune Response and Lymphangiogenesis in the Pathogenesis of Fetal Chylothorax

Fetal chylothorax (FC) is a rare condition characterized by lymphocyte-rich pleural effusion. Although its pathogenesis remains elusive, it may involve inflammation, since there are increased concentrations of proinflammatory mediators in pleural fluids. Only a few hereditary lymphedema-associated gene loci, e.g. VEGFR3, ITGA9 and PTPN11, were detected in human fetuses with this condition; these cases had a poorer prognosis, due to defective lymphangiogenesis. In the present study, genome-wide gene expression analysis was conducted, comparing pleural and ascitic fluids in three hydropic fetuses, one with and two without the ITGA9 mutation. One fetus (the index case), from a dizygotic pregnancy (the cotwin was unaffected), received antenatal OK-432 pleurodesis and survived beyond the neonatal stage, despite having the ITGA9 mutation. Genes and pathways involved in the immune response were universally up-regulated in fetal pleural fluids compared to those in ascitic fluids. Furthermore, genes involved in the lymphangiogenesis pathway were down-regulated in fetal pleural fluids (compared to ascitic fluid), but following OK-432 pleurodesis, they were up-regulated. Expression of ITGA9 was concordant with overall trends of lymphangiogenesis. In conclusion, we inferred that both the immune response and lymphangiogenesis were implicated in the pathogenesis of fetal chylothorax. Furthermore, genome-wide gene expression microarray analysis may facilitate personalized medicine by selecting the most appropriate treatment, according to the specific circumstances of the patient, for this rare, but heterogeneous disease