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N Kido

Publications and source records attributed to N Kido.

At least 37 records · Page 2Linked to original sources
PubMed1999

[Hepatolithiasis and Caroli's disease in Argentina: results of a multicenter study].

The goal of this study was to determine the prevalence, epidemiology and clinical-therapeutical evolution of hepatolithiasis (HL) in Argentina. With this purpose a survey was conducted sending a questionnaire to ten referencial and interventional radiology centers in the country. Seven centers answered on time. In the last five years a total of 8,736 consecutive patients were examined for cholangiography (endoscopic retrograde cholangiography, PTC). A total of 5,920 (68%) were biliary lithiasis and 53 (0.9%, range 0.5-2.6%) of these were HL. In case of HL the diagnostic procedure was the ERCP in 68% of the cases, and the PTC in the remainder 32%. The patients with HL (53% females, mean age 52, range 23-85) clinically presented cholangitis (79%); pancreatitis (6%) and five (9.4%) showed evolution to a biliary cirrhosis. Associated diseases or abnormalities of the biliary tree were: biliary postsurgical strictures (BPS), 28%; Caroli's Syndrome, 20%; and choledocholithiasis, 28%. While a 9.4% presented a "biliary history" (that was defined as two or more episodes of biliary surgery) and a 5.7% lacked associated or predisposing diseases. Follow-up was lost in 23% of the cases and in 77% a follow up of 38 months (range 8-60) was observed with 4.8% mortality rate. The treatment was hepatobiliary surgery in 58% of the cases; endoscopic papillotomy in 17% and combined treatments that included extracorporeal shock wave lithotripsy and ursodeoxycholic acid (UDCA) in 15%. Four out of 53 cases (7.5%) received UDCA as the only successful therapy. HL is an entity with high biliary morbidity in 85% of the cases and development in to cirrhosis in 9.4%. When the diagnosis is made in the western world both BPS and Caroli must be discarded first. Combined treatments or only UDCA are new therapeutical alternative in the western world.

Adult↗
PubMed1998

Synthesis of Escherichia coli O9a polysaccharide requires the participation of two domains of WbdA, a mannosyltransferase encoded within the wb* gene cluster.

WbdA (previously MtfA) is one of the mannosyltransferases encoded within the Escherichia coli O9a wb* gene cluster. It is composed of two domains of similar size, connected by an alpha-helix chain. Elimination of the C-terminal half by transposon insertion or gene deletion caused synthesis of an altered structural O-polysaccharide consisting only of alpha-1,2-linked mannose. O9a polysaccharide synthesis was restored by the C-terminal half of WbdA in trans. No membrane incorporation of mannose from GDP mannose was observed in a strain carrying only the gene for truncated WbdA. For mannose incorporation, it was necessary to introduce both wbdB and wbdC genes into the strain. Therefore, it is likely that the N-terminal half of truncated WbdA synthesizes the altered O-polysaccharide together with other mannosyltransferases which participate in the initial reactions of the O9a polysaccharide synthesis. Both N- and C-terminal domains of WbdA are required for the synthesis of the complete E. coli O9a polysaccharide. The chi sequence location between the two domains and homology plot analyses of the wbdA and the WbdA protein suggested that the wbdA gene might have arisen by fusion of two independent genes.

Conserved Sequence↗
PubMed1998

Generation of Escherichia coli O9a serotype, a subtype of E. coli O9, by transfer of the wb* gene cluster of Klebsiella O3 into E. coli via recombination.

Genetic characterization of the wb* gene in a series of Escherichia coli and Klebsiella strains possessing the mannose homopolymer as the O-specific polysaccharide was carried out. The partial nucleotide sequences and PCR-restriction fragment length polymorphism analysis suggested that E. coli serotype O9a, a subtype of E. coli O9, might have been generated by the insertion of the Klebsiella O3 wb* gene into a certain E. coli strain.

Bacterial Proteins↗
PubMed1997

Evolutionary relationship among rfb gene clusters synthesizing mannose homopolymer as O-specific polysaccharides in Escherichia coli and Klebsiella.

In order to clarify the evolutionary relationship among rfb gene clusters synthesizing mannose homopolymer as O-specific polysaccharides in Escherichia coli and Klebsiella, we studied the DNA sequence of the boundary region between the rfb and his genes in a series of strains possessing mannose homopolymer as O-specific polysaccharide. All had a characteristic gene organization carrying no gene between the rfb and his genes. Further, the recombination event was suggested to occur at the same site of the hisI gene in those strains. It was suggested that there was a close evolutionary relationship among rfb gene clusters synthesizing mannose homopolymer as O-specific polysaccharide in E. coli and Klebsiella.

Bacterial Proteins↗
PubMed1997

A unique DNA sequence of human enterotoxigenic Escherichia coli enterotoxin encoded by chromosomal DNA.

We detected Ent plasmids in 300 strains of human enterotoxigenic Escherichia coli, but one strain, E. coli 240-3, had neither a small nor a large plasmid and encoded the heat-labile enterotoxin (LTh(240-3)) gene on its chromosome. DNA sequences showed that LTh(240-3) differed by 12 and 14 base pairs from LT (LTh) and LT (LTp) from human H10407 and porcine EWD299 strains, respectively. In deduced precursor toxins, LTh(240-3), LTh and LTp differed from LTh, LTp and LTh(240-3) at nine, eight and eleven positions, respectively. These data suggest that although LTh(240-3) encoded in the chromosome is antigenically similar to LTh, it cannot be grouped with LTh due to differences in its DNA and amino acids sequences.

Amino Acid Sequence↗
PubMed1997

Production of monoclonal antibody discriminating serological difference in Escherichia coli O9 and O9a polysaccharides.

A monoclonal antibody (mAb) with a unique antigenic specificity against Escherichia coli O9 was produced. The O9a mAb was reactive with a part of the strains in E. coli O9. The O9a mAb did not react with LPS from the E. coli O9 test strain Bi316-42. The distribution of the antigen defined by the O9a mAb in E. coli O9 was consistent with that of E. coli O9a present in E. coli O9 strains. The chemical structure of the repeating unit of the O-specific polysaccharide detected by the mAb was demonstrated to be a mannotetraose by two-dimensional nuclear magnetic resonance spectroscopy. It was confirmed that the mAb recognized E. coli O9a serotype in E. coli O9 serotype strains, suggesting that E. coli O9a serotype might be a dominant strain in E. coli O9.

Animals↗
PubMed1997

Marked reduction of mouse peritoneal CD5+ B cells by intraperitoneal administration of lipopolysaccharide.

Intraperitoneal administration of lipopolysaccharide to mice induced a marked reduction of CD5+ B cells in the peritoneal cavity. The reduction was not induced by intravenous, subcutaneous, or oral administration of lipopolysaccharide. The reduction continued for about 10 days after the injection, and the CD5+ B-cell count recovered to the normal state about 14 days after the injection. The reduction of peritoneal CD5+ B cells might be caused by apoptotic cell death. Injection of lipopolysaccharide did not result in production of antibody to lipopolysaccharide. On the other hand, intraperitoneal injection of heat-killed bacteria did not induce a reduction of peritoneal CD5+ B cells and elicited the definite production of antibody to lipopolysaccharide.

Animals↗
PubMed1997

Recent progress in treating patients with cleft palate.

Over the last 4 decades remarkable progress has been made in the treatment of cleft palate: the rate of attaining normal or nearly normal speech after surgery has risen from about 65% 40 years ago to nearly 90% or more nowadays. One of the main factors is intratracheal intubation anesthesia that has made the surgery much safer and easier. Improved surgical technique and speech therapy also played a great role. This paper deals with two problems: (1) Slight velopharyngeal incompetence: The combined use of fiberscopy and fluorovideoscopy can provide useful information as to: (a) the exact place of the faulty articulation, (b) the detailed pattern of inconsistent velopharyngeal function, (c) changes in articulation induced by speech therapy, and (d) the relation between velopharyngeal function and faulty articulation. All the above information greatly facilitates speech therapy for cleft palate speech. It should be done with utmost care though due to possible adverse effects of radiation. (2) Analysis of faulty articulation. It was revealed that faulty articulations such as laryngeal fricative and affricates, pharyngeal stop, and glottal stop in cleft palate speech, secondary to velopharyngeal incompetence, were produced by articulation in the larynx at various sites such as the epiglottis, arytenoids, aryepiglottic folds and vocal folds. These faulty articulation points were located lower than supposed on the basis of auditory perception.

Adolescent↗
PubMed1996

Chemisorption of proteins and their thiol derivatives onto gold surfaces: characterization based on electrochemical nonlinearity.

This study was conducted to monitor the electrochemical responses of two proteins (bovine serum albumin (BSA) and gelatin) and their thiol derivatives adsorbed onto gold (Au) electrodes, which were analyzed by a "nonlinear" impedance method. A sinusoidal voltage is applied to a protein-containing aqueous solution and the waveform of the output current is analyzed by fast Fourier transformation (FFT). The intensities of the higher harmonics in the FFT varied with the species of protein and their thiol derivatives, and with time. From the higher harmonics, voltage-dependent capacitance and conductance were quantitatively evaluated to differentiate the state of adsorbed protein. Adsorption and desorption characteristics of BSA and its thiol derivative on the Au surface were continuously measured by a quartz crystal microbalance (QCM) in situ. The microscopic state of thiol-derivatized BSA adsorbed onto the Au surface was imaged by atomic force microscopy (AFM). In general, thiol-derivatized proteins were tightly adsorbed on the Au surface and showed no desorption. The present electrochemical measurements clearly differentiated adsorption characteristics of physically adsorbed (physisorbed) and chemically adsorbed (chemisorbed) proteins on Au surfaces.

Journal Article↗
PubMed1996

Bacterial polysaccharide synthesis and gene nomenclature.

Gene nomenclature for bacterial surface polysaccharides is complicated by the large number of structures and genes. We propose a scheme applicable to all species that distinguishes different classes of genes, provides a single name for all genes of a given function and greatly facilitates comparative studies.

Computer Communication Networks↗
PubMed1996

Crystallization of an R-form lipopolysaccharide from Klebsiella pneumoniae.

An R-form lipopolysaccharide (LPS) from Klebsiella pneumoniae strain LEN-111 (03-:K1-) formed crystals, whose shapes were elongated hexagonal plates, trapezoid plates, and rhomboid plates, and whose greatest dimensions were 3.1 x 0.8 microns, when it was suspended in 50 mM Tris buffer at pH 8.5 containing 5 mM MgCl2 and kept at 4 C for as long as 870 days. K. pneumoniae LEN-111 synthesized LPS molecules possessing incomplete repeating units of the O-antigenic polysaccharide portion besides the R-form LPS because of a leaky characteristic, but crystals consisted exclusively of the R-form LPS. Although the size of crystals was not large enough for X-ray analysis and limited crystallographic information was available, it was suggested that the crystals consist of hexagonal lattices with an alpha axis of 4.62 A and c axis of 79.8 +/- 2.6 A. The present results showed that R-form LPS lacking the O-antigenic polysaccharide portion tends to form crystals during long-term incubation in Tris buffer at pH 8.5 containing MgCl2 at 4 C.

Crystallography, X-Ray↗
PubMed1996

Differential release of smooth-type lipopolysaccharide from Pseudomonas aeruginosa treated with carbapenem antibiotics and its relation to production of tumor necrosis factor alpha and nitric oxide.

Endotoxin release from Pseudomonas aeruginosa treated with cell wall-active carbapenem antibiotics and its effect on the production of tumor necrosis factor alpha and nitric oxide were examined. Treatment of bacteria with imipenem induced much lower levels of endotoxin release than treatment with meropenem. The endotoxin released was demonstrated to be of the smooth type and O-specific polysaccharide-rich. The exposure of the filtrates of P. aeruginosa treated with imipenem to physiologically relevant cells caused low-level production of tumor necrosis factor alpha and nitric oxide, while similar treatment with meropenem induced high levels of production.

Carbapenems↗
PubMed1996

Augmented immunological activities of recombinant lipopolysaccharide possessing the mannose homopolymer as the O-specific polysaccharide.

Recombinant lipopolysaccharide possessing the mannose homopolymer as the O-specific polysaccharide was manufactured genetically by transforming Escherichia coli K-12 with various rfb genes capable of synthesizing the mannose homopolymer. Recombinant lipopolysaccharide exhibited levels of anticomplement activity, adjuvant activity, and regional lymph node-enlarging activity much higher than those exhibited by the original rough-type lipopolysaccharide from E. coli K-12 or lipopolysaccharide possessing the heteropolysaccharide from E. coli O111. Immunological activities of recombinant lipopolysaccharide were as strong as those of wild-type lipopolysaccharide possessing the mannose homopolymer. Characteristic activities of wild-type lipolysaccharide possessing the mannose homopolymer were exhibited by recombinant lipopolysaccharide. The abilities of lipopolysaccharide to activate B cells polyclonally and to produce cytokines did not seem to be related to the presence of the mannose homopolymer. Therefore, it was suggested that the mannose homopolymer in the O-specific polysaccharide might exclusively enhance anticomplement activity, adjuvant activity, and regional lymph node-enlarging activity among various lipid A activities.

Adjuvants, Immunologic↗
PubMed1995

Expression of the O9 polysaccharide of Escherichia coli: sequencing of the E. coli O9 rfb gene cluster, characterization of mannosyl transferases, and evidence for an ATP-binding cassette transport system.

The rfb gene cluster of Escherichia coli O9 directs the synthesis of the O9-specific polysaccharide which has the structure -->2-alpha-Man-(1-->2)-alpha-Man-(1-->2)-alpha-Man-(1-->3)-alpha- Man-(1-->. The E. coli O9 rfb cluster has been sequenced, and six genes, in addition to the previously described rfbK and rfbM, were identified. They correspond to six open reading frames (ORFs) encoding polypeptides of 261, 431, 708, 815, 381, and 274 amino acids. They are all transcribed in the counter direction to those of the his operon. No gene was found between rfb and his. A higher G+C content indicated that E. coli O9 rfb evolved independently of the rfb clusters from other E. coli strains and from Shigella and Salmonella spp. Deletion mutagenesis, in combination with analysis of the in vitro synthesis of the O9 mannan in membranes isolated from the mutants, showed that three genes (termed mtfA, -B, and -C, encoding polypeptides of 815, 381, and 274 amino acids, respectively) directed alpha-mannosyl transferases. MtfC (from ORF274), the first mannosyl transferase, transfers a mannose to the endogenous acceptor. It critically depended on a functional rfe gene (which directs the synthesis of the endogenous acceptor) and initiates the growth of the polysaccharide chain. MtfB (from ORF381) then transfers two mannoses into the 3 position of the previous mannose, and MtfA (from ORF815) transfers three mannoses into the 2 position. Further chain growth needs only the two transferases MtfA and MtfB. Thus, there are fewer transferases needed than the number of sugars in the repeating unit. Analysis of the predicted amino acid sequence of the ORF261 and ORF431 proteins indicated that they function as components of an ATP-binding cassette transport system. A possible correlation between the mechanism of polymerization and mode of membrane translocation of the products is discussed.

ATP-Binding Cassette Transporters↗
PubMed1994

Genetic analysis of Escherichia coli O9 rfb: identification and DNA sequence of phosphomannomutase and GDP-mannose pyrophosphorylase genes.

Subcloning, transposon insertion, and deletion analysis revealed that the Escherichia coli O9 rfb region is about 12 kb in size. The region encodes at least seven polypeptides of 89, 74, 55, 50, 44, 41 and 39.5 kDa. Southern hybridization analysis of rfb regions of E. coli O8 and O9, and Klebsiella O3 and O5 serotypes (all of these O polysaccharides are mannose homopolymers and the structures of the repeating unit of E. coli O9 and Klebsiella O3 are identical) showed that a central region specific for E. coli O9 and Klebsiella O3 is flanked by two regions common to all four. Complementation experiments using strains with known defects and specific tests for the enzymic activity showed that the 50 and 55 kDa polypeptides, encoded by the common region, are phosphomannomutase (PMM) and GDP-mannose pyrophosphorylase (GMP), respectively. Nucleotide sequencing of the region revealed the presence of two genes, rfbK and rfbM, analogous to the corresponding genes of Salmonella typhimurium. In E. coli O9, rfbK and rfbM encode proteins of 460 amino acids (50,809 Da) and 471 amino acids (52,789 Da). The amino acid sequence of GMP was conserved in RfbMs of E. coli O7 and Salmonella groups B, C1 and C2, CpsB of S. typhimurium, AlgA of Pseudomonas aeruginosa, and XanB of Xanthomonas campestris. The phylogenetic trees of PMM and GMP were different in topology and in the evolutionary distances from ancestors.

Amino Acid Sequence↗
PubMed1994

Crystallization and analyses of crystals of various chemotypes of R-form lipopolysaccharides from Salmonella spp.

Various chemotypes (Re, Rd2, Rd1P-, Rd1, RcP-, Rc, Rb3, Rb2, Rb1, and Ra) of R-form lipopolysaccharides (LPSs) of Salmonella spp. were crystallized by treatment with 70% ethanol containing 250 mM MgCl2, and crystals of the LPSs were observed electron microscopically and analyzed by electron diffraction and synchrotron X-ray diffraction. All the LPSs tested formed three-dimensional crystals showing very similar shapes; hexagonal plate, solid column, discoid, square or rectangular plate, lozenge plate and truncated hexangular or rectangular pyramid forms. Electron diffraction patterns from the hexagonal plate crystals of all these LPSs obtained by electron irradiation from the direction perpendicular to the basal plane showed that they consist of hexagonal lattices with the lattice constant of 4.62 A. The crystals of all the LPSs thus formed gave ring-like X-ray diffraction patterns because of their small sizes. The long-axis values were calculated from the X-ray diffraction patterns from crystals of all the LPSs in the low-angle region and they corresponded roughly to the length of the proposed primary chemical structures of the R cores of the LPSs. The volume occupied by a single molecule of all the LPSs were calculated from the molecular weights based on the proposed structures and the crystallographic data obtained by electron diffraction, X-ray diffraction, and density determination.

Crystallization↗
PubMed1994

Cloning and analysis of duplicated rfbM and rfbK genes involved in the formation of GDP-mannose in Escherichia coli O9:K30 and participation of rfb genes in the synthesis of the group I K30 capsular polysaccharide.

The rfbO9 gene cluster, which is responsible for the synthesis of the lipopolysaccharide O9 antigen, was cloned from Escherichia coli O9:K30. The gnd gene, encoding 6-phosphogluconate dehydrogenase, was identified adjacent to the rfbO9 cluster, and by DNA sequence analysis the gene order gnd-rfbM-rfbK was established. This order differs from that described for other members of the family Enterobacteriaceae. Nucleotide sequence analysis was used to identify the rfbK and rfbM genes, encoding phosphomannomutase and GDP-mannose pyrophosphorylase, respectively. In members of the family Enterobacteriaceae, these enzymes act sequentially to form GDP-mannose, which serves as the activated sugar nucleotide precursor for mannose residues in cell surface polysaccharides. In the E. coli O9:K30 strain, a duplicated rfbM2-rfbK2 region was detected approximately 3 kbp downstream of rfbM1-rfbK1 and adjacent to the remaining genes of the rfbO9 cluster. The rfbM isogenes differed in upstream flanking DNA but were otherwise highly conserved. In contrast, the rfbK isogenes differed in downstream flanking DNA and in 3'-terminal regions, resulting in slight differences in the sizes of the predicted RfbK proteins. RfbMO9 and RfbKO9 are most closely related to CpsB and CpsG, respectively. These are isozymes of GDP-mannose pyrophosphorylase and phosphomannomutase, respectively, which are thought to be involved in the biosynthesis of the slime polysaccharide colanic acid in E. coli K-12 and Salmonella enterica serovar Typhimurium. An E. coli O-:K30 mutant, strain CWG44, lacks rfbM2-rfbK2 and has adjacent essential rfbO9 sequences deleted. The remaining chromosomal genes are therefore sufficient for GDP-mannose formation and K30 capsular polysaccharide synthesis. A mutant of E. coli CWG44, strain CWG152, was found to lack GDP-mannose pyrophosphorylase and lost the ability to synthesize K30 capsular polysaccharide. Wild-type capsular polysaccharide could be restored in CWG152, by transformation with plasmids containing either rfbM1 or rfbM2. Introduction of a complete rfbO9 gene cluster into CWG152 restored synthesis of both O9 and K30 polysaccharides. Consequently, rfbM is sufficient for the biosynthesis of GDP-mannose for both O antigen and capsular polysaccharide E. coli O9:K30. Analysis of a collection of serotype O8 and O9 isolates by Southern hybridization and PCR amplification experiments demonstrated extensive polymorphism in the rfbM-rfbK region.

Amino Acid Sequence↗