365 research outputs found

    Cryptococcus, Pathological observations of five autopsy cases and one biopsy case

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    Pathologic, anatomical, and histological findings of 5 autopsy cases and one biopsy case of cryptococcosis have been described. Macroscopically the foci of the lung are grayish white or yellowish white in color and range in size from the small acinous-nodular ones to the larger lobular-nodular ones. In the brain the meninx appears gelatinous and edematous showing many small spots with indistinct boundary and with grayish white color. Lymph nodes infected with fungi are swollen in various degrees. Histologically the foci are mainly consisted of granulomatous inflammation containing giant cells. Besides, there are small degenerative foci having no inflammatory response and the lesions of marked fibrosis; the former will be newly formed foci and the latter the old ones. The size of C. neoformans found in tissue ranges from 3 to 30 &#956;, and the majority of fungi possess thick gelatinous capsule, but some of them in granulative lesions often possess no capsule. From the staining properties the capsule of C. neoformans is believed to be a kind of acid mucopolysaccharide. As for the staining method including general fungi, GOMORI's methenamine silver method is best, especially for the detailed examination of fungus structures, and for the differential diagnosis mucicarmine stain is the most suitable one. In tracing the distribution of the foci in the various organs, it seems that the first attack of this fungus occurs in the lung. The authors have called general attention, through their own experiences, to the fact that the small granulomatous foci caused by Cryptococcus infection, especially in the lung, may often escape the detection at autopsy.</p

    Corynebacterium ulcerans 0102 carries the gene encoding diphtheria toxin on a prophage different from the C. diphtheriae NCTC 13129 prophage

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    BACKGROUND: Corynebacterium ulcerans can cause a diphtheria-like illness, especially when the bacterium is lysogenized with a tox gene-carrying bacteriophage that produces diphtheria toxin. Acquisition of toxigenicity upon phage lysogenization is a common feature of C. ulcerans and C. diphtheriae. However, because of a lack of C. ulcerans genome information, a detailed comparison of prophages has not been possible between these two clinically important and closely related bacterial species. RESULTS: We determined the whole genome sequence of the toxigenic C. ulcerans 0102 isolated in Japan. The genomic sequence showed a striking similarity with that of Corynebacterium pseudotuberculosis and, to a lesser extent, with that of C. diphtheriae. The 0102 genome contained three distinct prophages. One of these, ΦCULC0102-I, was a tox-positive prophage containing genes in the same structural order as for tox-positive C. diphtheriae prophages. However, the primary structures of the individual genes involved in the phage machinery showed little homology between the two counterparts. CONCLUSION: Taken together, these results suggest that the tox-positive prophage in this strain of C. ulcerans has a distinct origin from that of C. diphtheriae NCTC 13129

    Characterization of the gut microbiota of Kawasaki disease patients by metagenomic analysis

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    Kawasaki disease (KD) is an acute febrile illness of early childhood. Previous reports have suggested that genetic disease susceptibility factors, together with a triggering infectious agent, could be involved in KD pathogenesis; however, the precise etiology of this disease remains unknown. Additionally, previous culture-based studies have suggested a possible role of intestinal microbiota in KD pathogenesis. In this study, we performed metagenomic analysis to comprehensively assess the longitudinal variation in the intestinal microbiota of twenty-eight KD patients. Several notable bacterial genera were commonly extracted during the acute phase, whereas a relative increase in the number of Ruminococcus bacteria was observed during the non-acute phase of KD. The metagenomic analysis results based on bacterial species classification suggested that the number of sequencing reads with similarity to five Streptococcus spp. (S. pneumonia, pseudopneumoniae, oralis, gordonii, and sanguinis), in addition to patient-derived Streptococcus isolates, markedly increased during the acute phase in most patients. Streptococci include a variety of pathogenic bacteria and probiotic bacteria that promote human health; therefore, this further species discrimination could comprehensively illuminate the KD-associated microbiota. The findings of this study suggest that KD-related Streptococci might be involved in the pathogenesis of this disease

    H-DBAS: Alternative splicing database of completely sequenced and manually annotated full-length cDNAs based on H-Invitational

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    The Human-transcriptome DataBase for Alternative Splicing (H-DBAS) is a specialized database of alternatively spliced human transcripts. In this database, each of the alternative splicing (AS) variants corresponds to a completely sequenced and carefully annotated human full-length cDNA, one of those collected for the H-Invitational human-transcriptome annotation meeting. H-DBAS contains 38 664 representative alternative splicing variants (RASVs) in 11 744 loci, in total. The data is retrievable by various features of AS, which were annotated according to manual annotations, such as by patterns of ASs, consequently invoked alternations in the encoded amino acids and affected protein motifs, GO terms, predicted subcellular localization signals and transmembrane domains. The database also records recently identified very complex patterns of AS, in which two distinct genes seemed to be bridged, nested or degenerated (multiple CDS): in all three cases, completely unrelated proteins are encoded by a single locus. By using AS Viewer, each AS event can be analyzed in the context of full-length cDNAs, enabling the user's empirical understanding of the relation between AS event and the consequent alternations in the encoded amino acid sequences together with various kinds of affected protein motifs. H-DBAS is accessible at

    Spin relaxation in CdTe/ZnTe quantum dots

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    We have measured photoluminescence (PL) spectra and time-resolved PL in CdTe quantum dots (QDs) under the longitudinal magnetic field up to 10T. Circular polarization of PL increases with increasing magnetic field, while its linear polarization is absent under linearly polarized excitation. Time-resolved PL measurements clarified that this behavior is caused by the suppression of spin relaxation induced by the longitudinal magnetic field. We believe that this behavior is related to the hyperfine interaction of electron spin with magnetic momenta of lattice nuclei

    Complete Genome Sequence of blaIMP–6-Positive Metakosakonia sp. MRY16-398 Isolate From the Ascites of a Diverticulitis Patient

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    A novel species of carbapenemase-producing Enterobacteriaceae (CPE) was isolated from a patient diagnosed with sigmoid colon diverticulitis. At first, laboratory testing suggested it was Klebsiella oxytoca or Pantoea sp.; however, a complete genome sequence of the isolate, MRY16-398, revealed that it could be novel species, most similar to [Kluyvera] intestini, of which taxonomic nomenclature is still under discussion. Orthologous conserved gene analysis among 42 related bacterial strains indicated that MRY16-398 was classified as the newly proposed genus Metakosakonia. Further, MRY16-398 was found to harbor the blaIMP-6 gene-positive class 1 integron (In722) in plasmid pMRY16-398_2 (IncN replicon, 47.4 kb in size). This finding implies that rare and opportunistic bacteria could be potential infectious agents. In conclusion, our results highlight the need for continuous monitoring for CPE even in nonpathogenic bacteria in the nosocomial environment

    Determination of topological structure of ARL6ip1 in cells: Identification of the essential binding region of ARL6ip1 for conophylline

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    AbstractConophylline (CNP) has various biological activities, such as insulin production. A recent study identified ADP-ribosylation factor-like 6-interacting protein 1 (ARL6ip1) as a direct target protein of CNP. In this study, we revealed that ARL6ip1 is a three-spanning transmembrane protein and determined the CNP-binding domain of ARL6ip1 by deletion mutation analysis of ARL6ip1 with biotinyl-amino-CNP. These results suggest that CNP is expected to be useful for future investigation of ARL6ip1 function in cells. Because of the anti-apoptotic function of ARL6ip1, CNP may be an effective therapeutic drug and/or a novel chemosensitizer for human cancers and other diseases

    Characterization of Quasispecies of Pandemic 2009 Influenza A Virus (A/H1N1/2009) by De Novo Sequencing Using a Next-Generation DNA Sequencer

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    Pandemic 2009 influenza A virus (A/H1N1/2009) has emerged globally. In this study, we performed a comprehensive detection of potential pathogens by de novo sequencing using a next-generation DNA sequencer on total RNAs extracted from an autopsy lung of a patient who died of viral pneumonia with A/H1N1/2009. Among a total of 9.4×106 40-mer short reads, more than 98% appeared to be human, while 0.85% were identified as A/H1N1/2009 (A/Nagano/RC1-L/2009(H1N1)). Suspected bacterial reads such as Streptococcus pneumoniae and other oral bacteria flora were very low at 0.005%, and a significant bacterial infection was not histologically observed. De novo assembly and read mapping analysis of A/Nagano/RC1-L/2009(H1N1) showed more than ×200 coverage on average, and revealed nucleotide heterogeneity on hemagglutinin as quasispecies, specifically at two amino acids (Gly172Glu and Gly239Asn of HA) located on the Sa and Ca2 antigenic sites, respectively. Gly239 and Asn239 on antigenic site Ca2 appeared to be minor amino acids compared with the highly distributed Asp239 in H1N1 HAs. This study demonstrated that de novo sequencing can comprehensively detect pathogens, and such in-depth investigation facilitates the identification of influenza A viral heterogeneity. To better characterize the A/H1N1/2009 virus, unbiased comprehensive techniques will be indispensable for the primary investigations of emerging infectious diseases

    Complete Genome Sequence and Characterization of Linezolid-Resistant Enterococcus faecalis Clinical Isolate KUB3006 Carrying a cfr(B)-Transposon on Its Chromosome and optrA-Plasmid

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    Linezolid (LZD) has become one of the most important antimicrobial agents for infections caused by gram-positive bacteria, including those caused by Enterococcus species. LZD-resistant (LR) genetic features include mutations in 23S rRNA/ribosomal proteins, a plasmid-borne 23S rRNA methyltransferase gene cfr, and ribosomal protection genes (optrA and poxtA). Recently, a cfr gene variant, cfr(B), was identified in a Tn6218-like transposon (Tn) in a Clostridioides difficile isolate. Here, we isolated an LR Enterococcus faecalis clinical isolate, KUB3006, from a urine specimen of a patient with urinary tract infection during hospitalization in 2017. Comparative and whole-genome analyses were performed to characterize the genetic features and overall antimicrobial resistance genes in E. faecalis isolate KUB3006. Complete genome sequencing of KUB3006 revealed that it carried cfr(B) on a chromosomal Tn6218-like element. Surprisingly, this Tn6218-like element was almost (99%) identical to that of C. difficile Ox3196, which was isolated from a human in the UK in 2012, and to that of Enterococcus faecium 5_Efcm_HA-NL, which was isolated from a human in the Netherlands in 2012. An additional oxazolidinone and phenicol resistance gene, optrA, was also identified on a plasmid. KUB3006 is sequence type (ST) 729, suggesting that it is a minor ST that has not been reported previously and is unlikely to be a high-risk E. faecalis lineage. In summary, LR E. faecalis KUB3006 possesses a notable Tn6218-like-borne cfr(B) and a plasmid-borne optrA. This finding raises further concerns regarding the potential declining effectiveness of LZD treatment in the future
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