Clostridial deep neck infection developed after extraction of a tooth: a case report and review of the literature in Japan

A rare case of severe deep neck infection caused by clostridia after extraction of the left lower canine is presented. The patient was a 63-year-old Japanese woman who had a history of diabetes. The pertinent literature in Japan is reviewed and discussed.

The ptsI gene encoding enzyme I of the phosphotransferase system of Corynebacterium glutamicum

The phosphoenolpyruvate:carbohydrate phosphotransferase system (PTS) is widespread among bacteria where it mediates carbohydrate uptake and often serves in carbon control. Here we present cloning and analysis of the monocistronic ptsI gene of Corynebacterium glutamicum R, which encodes PTS Enzyme I (EI). EI catalyzes the first reaction of PTS and the reported ptsI was shown to complement the corresponding defect in Escherichia coli. The deduced 59.2-kDa EI of 564 amino acids shares more than 50% homology with EIs from Bacillus stearothermophilus, Bacillus subtilis, and Lactobacillus sake. Chromosomal inactivation of ptsI demonstrated that EI plays an indispensable role in PTS of C. glutamicum R and this system represents a dominant sugar uptake system. Cellobiose was only transported and utilized in adaptive mutants of C. glutamicum R. Cellobiose transport was also found to be PTS-dependent and repressed by PTS sugar glucose.

Structure of the urease operon of Corynebacterium glutamicum

Urease activity of Corynebacterium glutamicum results in a rapid pH increase upon addition of urea to the growth medium. The urease operon C. glutamicum was isolated of and sequenced. Seven open reading frames were identified; ureA, ureB, and ureC were homologues of other bacterial urease structural genes, ureE, ureF, ureG, and ureD exhibited homology to urease accessory genes. Disruption of ureC prevented the utilization of urea as a nitrogen source by C. glutamicum. Urease activity was induced by urea and appeared to be independent of the nitrogen regulatory system. Urease activity was not affected by pH. Heterologous expression of a truncated derivative of the urease gene cluster in Escherichia coli showed that ureD was necessary for active expression. Western-blot and primer extension analysis on C. glutamicum grown under different conditions confirmed that the operon was induced by urea. Transcriptional startpoint for the ureA gene was determined.

Characterization of four cell lines derived from a human malignant fibrous histiocytoma of the maxillary sinus

We have established four cell lines from a human malignant fibrous histiocytoma. Each cell line had human aneuploid karyotype and DNA aneuploidy. Cells in all lines expressed CD13, CD68 and vimentin but lacked CD11, CD14, CD15, CD16, CD45, HLA class II and other mesenchymal and epithelial markers such as desmin, alpha-smooth muscle, myoglobin, S-100 protein, and cytokeratin. None of the cells expressed surface IgG or C3 receptor, nor did any of them phagocytose latex particles. The cells reacted with an antibody for prolyl-4-hydroxylase, but no collagen (types I, II, III, or IV) was detected in any of the cell lines. The homogenates of all cell lines had cyclic nucleotide phosphodiesterase 3 activity. Two cell lines produced granulocyte colony-stimulating factor (G-CSF), interleukin (IL)-1alpha, IL-6 and tumor necrosis factor alpha, another line produced G-CSF, IL-1alpha, IL-6 and platelet-derived growth factor (PDGF)-AB, and the remaining cell line produced only PDGF-AB. None of the cells produced transforming growth factor-alpha. The results indicated that the cell lines were immunophenotypically similar to primitive mesenchymal cells.

Structure, expression and products of the ribosomal RNA operons of Rhodopseudomonas palustris No. 7

Rhodopseudomonas palustris strains carry one or two ribosomal rRNA operons, and those with duplicated rrn operons grow faster. The two rrn operons in R. palustris No. 7 are virtually identical over a 54,70-bp stretch containing the genes for 16S rRNA, tRNAile, tRNAala, 23S rRNA and 5S rRNA, as well as the intergenic spacers and part of the extragenic spacer. In R. palustris, unlike most bacteria with multiple rrn operons, the putative promoter sequences of the two operons are highly diverged, suggesting possible functional differentiation. By simultaneous primer-extension analysis of both pre-rRNAs, we detected a two-fold higher level of expression from rrnA under photoautotrophic conditions. Alteration of the conditions of growth leads to changes in the relative levels of expression of the two operons. Within the 5,470-bp segment, only two sequence differences are found between the 23S rRNA genes; one is at the center of the 23S rRNA molecule and affects a site of unknown function, and the other is within or immediately adjacent to sequences involved in processing of the 5' 23S rRNA IVS. In vitro processing of 5' IVS-containing 23S rRNA precursors from each operon does not reveal any detectable difference between them. The 5' ends of the mature 16S, 23S, and 5S rRNAs were determined by primer-extension analysis, and the 3' end of 23S rRNA was determined by RNA linker ligation-mediated cDNA cloning. The 5' and 3' ends of the R. palustris 23S rRNA molecule are extensively processed, suggesting that, unlike the situation in the established eubacterial model, these ends cannot basepair.

Bacteriophage WO and virus-like particles in Wolbachia, an endosymbiont of arthropods

Wolbachia are intracellular symbionts mainly found in arthropods, causing various sexual alterations on their hosts by unknown mechanisms. Here we report the results that strongly suggest that Wolbachia have virus-like particles of phage WO, which was previously identified as a prophage-like element in the Wolbachia genome. Wolbachia (strain wTai) infection in an insect was detected with the antibody against Wsp, an outer surface protein of Wolbachia, by fluorescence microscopy and immunoelectron-microscopy for the first time. Virus-like particles in Wolbachia were observed by electron-microscopy. The 0.22-microm filtrate of insect ovary contained DAPI-positive particles, and PCR analysis demonstrated that a phage WO DNA passed through the filter while Wolbachia DNA were eliminated, suggesting that the DAPI-positive particles were phage WO.

Two cases of totally submerging buried primary molars: characterization of clinical behavior and discussion of cause

Submerging buried tooth is a rare condition whose clinical characteristics are unclear. Two cases are reported of submerging buried maxillary second deciduous molar. A review of the literature in Japanese and English provides the clinical condition of the lesion and allows for discussion of its causes.

EXAFS measurements for liquid Ge-Si alloys

EXAFS measurements around the Ge-K edge have been carried out for liquid Ge-Si alloys for the first time to investigate the local structure around a Ge atom. To perform the EXAFS measurements for the liquid alloys with high melting temperatures, a new sapphire cell have been developed. The measurements were carried out for the liquid alloys from 10% to 60% of Si and the crystalline ones from 10% to 70% of Si as a reference. EXAFS oscillations, x(k), are observed even at 1480 degrees C for liquid Ge(0.4)Si(0.6). The position of the first peak in the radial distribution function obtained from Fourier transform of x(k) is shifted towards smaller distance for liquid and crystalline alloys with increasing Si concentration. The results of a curve-fit analysis in a harmonic approximation show that Ge-Ge and Ge-Si bonds in the liquid alloys become long with increasing Si concentration while those become slightly short in the crystaline ones.

Cloning of genes participating in aerobic biodegradation of p-cumate from Rhodopseudomonas palustris

Rhodopseudomonas palustris utilizes p-cumate as a carbon source both under anaerobic light and aerobic dark conditions. A gene cluster was isolated whose sequence showed high homology to genes which have been implicated the degradation of p-cumate in Pseudomonas pitida. Seven structural genes coding for dioxygenase-reductase, dihydroxy-dihydro dehydrogenase, and ring cleavage oxygenases were identified. A putative regulator and its possible recognition site was suggested on the basis of homology data. Mutant cells in which a kanamycin cassette was inserted into the dihydroxy-dihydro dehydrogenase gene could not grow aerobically on p-cumate. The mutation had no effect on growth using the para substituted benzoate derivatives 4-hydroxycinnamate, ferulate, protocatechuate, and 2,3,4-trihydroxybenzoate as sole carbon source. Moreover, mutant cells showed a growth pattern similar to wild type cells grown on these compounds under photoheterotrophic anaerobic conditions. These data suggest that genes of this operon are involved specifically in aerobic dissimilation of p-cumate. Intermediate products of p-cumate degradation could be detected from extracts of Escherichia coli heterologously expressing the first 5 genes responsible for the first two steps of p-cumate degradation in R. palustris. Primer extension analysis revealed the transcription regulation of the gene cluster which could be induced with para methyl-, ethyl- and isopropyl (cumate) benzoates. This is the first report on genes involved in aerobic degradation of these compounds in photosynthetic bacteria.

Divergent mechanisms of 5' 23S rRNA IVS processing in the alpha-proteobacteria

Widespread occurrence of a separate small RNA derived from the 5'-end of 23S rRNA and of an intervening sequence (IVS) which separates this domain from the main segment of 23S rRNA in the alpha-proteobacteria implies that processing reactions which act to excise the IVS are also maintained in this group. We previously characterized the first example of processing of this IVS in Rhodopseudomonas palustris, which is classified with the Bradyrhizobia In this case, IVS excision occurs by a multistep process and RNase III appears to act at an early step. Here, we characterize in vivo and in vitro IVS processing in two other related, but phenotypically distinct, Bradyrhizobia We also examine in vivo and in vitro processing of rRNA precursors from a more distantly related alpha-proteobacterium, Rhodobacter sphaeroides which produces a separate 5' 23S rRNA domain but has different sequences in the 5' 23S rRNA IVS. The details of the in vivo processing of all of the Bradyrhizobial rRNAs closely resemble the R. palustris example and in vitro studies suggest that all of the Bradyrhizobia utilize RNase III in the first step of IVS cleavage. Remarkably, in vivo and in vitro studies with R.sphaeroides indicate that initial IVS cleavage uses a different mechanism. While the mechanism of IVS cleavage differs among these alpha-proteobacteria, in all of these cases the limits of the internal segments processed in vivo are almost identical and occur far beyond the initial cleavage sites within the IVSs. We propose that these bacteria possess common secondary maturation pathways which enable them to generate similarly processed 23S rRNA 5'- and 3'-ends.

Stimulatory function of gp49A, a murine Ig-like receptor, in rat basophilic leukemia cells

Murine gp49, a 49-kDa type I transmembrane glycoprotein, is a member of the Ig-like receptors expressed on the surface of cells involved in natural immunity such as mast cells, NK cells, and macrophages. The two major subtypes, gp49A and gp49B, are encoded by two different genes adjacent to each other. gp49B contains an immunoreceptor tyrosine-based inhibitory motif in its cytoplasmic region and is known to function as an inhibitory molecule. In contrast, gp49A does not harbor any specific motif for signal transduction, nor has its physiological role been determined. Here we report on the stimulatory nature of gp49A by analyzing biochemical characteristics of chimeric molecules consisting of an ectodomain of Fc receptor and a C-terminal half of gp49A, namely the pretransmembrane, transmembrane, and cytoplasmic portions, expressed on the rat basophilic leukemia mast cell line. Cross-linking of the chimeric receptors evoked cytoplasmic calcium mobilization, PGD(2) release, and transcription of IL-3 and IL-4 genes, but did not elicit degranulation of the cells. The chimeric molecule could be expressed as a singlet and a homodimeric form on the cell surface. A pretransmembrane cysteine residue of gp49A was necessary for dimer formation. Dimerization was be necessary for their incorporation into glycolipid-enriched membrane fraction (GEM) upon cross-linking stimuli. The calcium mobilization response was inhibited by treatment of cells with methyl-beta-cyclodextrin, an inhibitor of GEM formation. Together with these results, it was strongly suggested that gp49A could be expressed as a homodimer and elicit activation signals that lead to calcium mobilization, eicosanoid production, and cytokine gene transcription through its incorporation into GEM.

Purification, cloning, and three-dimensional structure prediction of Micrococcus luteus FAD-containing tyramine oxidase

The FAD-containing tyramine oxidase enzyme and gene from the Gram (+) bacterium Micrococcus luteus were isolated, and computer prediction was used to propose a preliminary 3D model of the protein. A 2.8-kb Sau3AI fragment containing the structural gene of tyramine oxidase was cloned from a M. luteus genomic DNA library. The 1332 bp gene encodes a protein of 443 amino acids, with a calculated molecular mass of 49.1 kDa. The enzyme was found to be a homodimer with a molecular weight of 49,000. It oxidizes tyramine, adrenaline, 3-hydroxytyramine, dopamine, and noradrenaline, and was reversibly inhibited by FAD-containing monoamine oxidase A and B specific inhibitors. Sequence comparison show that tyramine oxidase is smaller than other FAD-amine oxidases but that it contains well-conserved amino acid residues reported in all other FAD-amine oxidases. A hypothetical three-dimensional structure of tyramine oxidase has also been proposed based on secondary structure predictions, threading, and comparative modeling.

Long-term outcome of chronic hepatitis B in adolescents or young adults in follow-up from childhood

BACKGROUND

It has not yet been defined whether children with chronic hepatitis B are likely to develop severe liver disease in the future. The purpose of this study was to evaluate the evolution of chronic hepatitis B acquired in childhood.

METHOD

Fifty-two children in the age range of 0 to 15 years who were positive for hepatitis B surface antigen and hepatitis B e antigen in serum for at least 6 months were enrolled in this study. In the majority of the 52 children, hepatitis B virus infection was acquired by perinatal transmission. All 52 showed abnormal liver function test findings for more than 6 months before enrollment, and the subjects were followed up longitudinally for 3 to 22 years (mean, 11 years). They are now more than 15 years of age (15-27 years old).

RESULTS

During the follow-up period, 26 (50%) children had spontaneous seroconversion to anti-hepatitis B e. Serum levels of alanine aminotransferase normalized in these 26 children. In one child of these children, hepatocellular carcinoma developed at the age of 21 years, 16 years after seroconversion, although his liver function profiles remained normal. The other 26 children remained hepatitis B e antigen positive, most with unchanged biochemical features. Sixteen (62%) children among these 26 children were treated with interferon-alpha. Eleven (69%) children had seroconversion to anti-hepatitis B e within the first year after the cessation of therapy. Hepatocellular carcinoma developed in 1 of these 11 children at the age of 16 years, 6 years after interferon therapy. Thus, hepatocellular carcinoma developed in two children in an anti-hepatitis B e positive phase.

CONCLUSION

All children carrying hepatitis B surface antigen should be observed carefully to monitor the possible development of hepatocellular carcinoma, especially in the antihepatitis B e-positive phase after spontaneous seroconversion or even after interferon treatment.

Sequence analysis of the cryptic plasmid pMG101 from Rhodopseudomonas palustris and construction of stable cloning vectors

A 15-kb cryptic plasmid was obtained from a natural isolate of Rhodopseudomonas palustris. The plasmid, designated pMG101, was able to replicate in R. palustris and in closely related strains of Bradyrhizobium japonicum and phototrophic Bradyrhizobium species. However, it was unable to replicate in the purple nonsulfur bacterium Rhodobacter sphaeroides and in Rhizobium species. The replication region of pMG101 was localized to a 3.0-kb SalI-XhoI fragment, and this fragment was stably maintained in R. palustris for over 100 generations in the absence of selection. The complete nucleotide sequence of this fragment revealed two open reading frames (ORFs), ORF1 and ORF2. The deduced amino acid sequence of ORF1 is similar to sequences of Par proteins, which mediate plasmid stability from certain plasmids, while ORF2 was identified as a putative rep gene, coding for an initiator of plasmid replication, based on homology with the Rep proteins of several other plasmids. The function of these sequences was studied by deletion mapping and gene disruptions of ORF1 and ORF2. pMG101-based Escherichia coli-R. palustris shuttle cloning vectors pMG103 and pMG105 were constructed and were stably maintained in R. palustris growing under nonselective conditions. The ability of plasmid pMG101 to replicate in R. palustris and its close phylogenetic relatives should enable broad application of these vectors within this group of alpha-proteobacteria.

Characterization of a separate small domain derived from the 5' end of 23S rRNA of an alpha-proteobacterium

We demonstrate the presence of a separate processed domain derived from the 5' end of 23S rRNA in ribosomes of Rhodopseudomonas palustris, a member of the alpha-++proteobacteria. Previous sequencing studies predicted intervening sequences (IVS) at homologous positions within the 23S rRNA genes of several alpha-proteobacteria, including R.palustris, and we find a processed 23S rRNA 5' domain in unfractionated RNA from several species. 5.8S rRNA from eukaryotic cytoplasmic large subunit ribosomes and the bacterial processed 23S rRNA 5' domain share homology, possess similar structures and are both derived by processing of large precursors. However, the internal transcribed spacer regions or IVSs separating them from the main large subunit rRNAs are evolutionarily unrelated. Consistent with the difference in sequence, we find that the site and mechanism of IVS processing also differs. Rhodopseudomonas palustris IVS-containing RNA precursors are cleaved in vitro by Escherichia coli RNase III or a similar activity present in R.palustris extracts at a processing site distinct from that found in eukaryotic systems and this results in only partial processing of the IVS. Surprisingly, in a reaction unlike characterized cases of eubacterial IVS processing, an RNA segment larger than the corresponding DNA insertion is removed which contains conserved sequences. These sequences, by analogy, serve to link the 23S rRNA 5' rRNA domains or 5.8S rRNAs to the main portion of other prokaryotic 23S rRNAs or to eukaryotic 28S rRNAs, respectively.