bluuebunny/crossref_metadata_2025_split huggingface dataset:
Crystallization of Lipopolysaccharide from a Salmonella typhimurium Semi‐Rough (SR) Mutant
Authors: Ito Hideo , Naito Setsuko , Arakawa Yoshichika , Sasaki Kyoyu , Kato Nobuo 
Published: November 2013

AbstractSalmonella typhimurium SR‐form lipopolysaccharide (LPS), consisting of a single repeating unit of the O‐antigenic polysaccharide, linked to the R‐core consisting of oligosaccharide that is, in turn, linked to lipid A, formed crystals whose shapes were hexagonal plates, discoids, and solid columns when precipitated by the addition of 2 volumes of 95% ethanol containing 375 mM MgCl2 and kept in 70% ethanol containing 250 mM MgCl2 at 4 C for 10 days. Among these crystals, the basic form is considered to be the hexagonal plates. Analyses of hexagonal plate crystals showed that they consist of hexagonal lattices with a lattice constant (a axis) of 4.62 Å and longitudinal axis (c axis) of approximately 100 Å. In X‐ray diffraction patterns in the low‐angle region, crystals of S. typhimurium SR‐form LPS exhibited much less distinct reflections when compared with crystals of synthetic Escherichia coli‐type lipid A. In contrast to the previous finding that S. minnesota S‐form LPS possessing the O‐antigenic polysaccharide does not crystallize under the same experimental conditions as used in the present study, the presence of a single repeating unit of the O‐antigenic polysaccharide does not inhibit crystallization.
Cauliflower Mosaic Virus ORF III Product Forms a Tetramer In Planta: Its Implication in Viral DNA Folding during Encapsidation
Authors: Tsuge Seiji , Kobayashi Kappei , Nakayashiki Hitoshi , Mise Kazuyuki , Furusawa Iwao 
Published: November 2013

AbstractCauliflower mosaic virus (CaMV) open reading frame (ORF) III encodes a 15 kDa protein; the function of which is as yet unknown. This protein has non‐sequence‐specific DNA binding activity and is associated with viral particles, suggesting that the ORF III product (P3) is involved in the folding of CaMV DNA during encapsidation. In this study, we demonstrated that P3 forms a tetramer in CaMV‐infected plants. A P3‐related protein with an apparent molecular weight of 60 kDa was detected by Western blotting analysis using anti‐P3 antiserum under non‐reducing conditions, while only 15 kDa P3 was detected under reducing conditions. Analysis of P3 using viable mutants with a 27‐bp insertion in either ORF III or IV revealed that the 60 kDa protein was a tetramer of P3. The P3 tetramer co‐sedimented with viral coat protein in multiple fractions on sucrose gradient centrifugation, suggesting that P3 tetramer binds to mature and immature virions. These results strongly suggested that CaMV P3 forms a tetramer in planta and that disulfide bonds are involved in its formation and/or stabilization. The finding of P3 tetramer in planta suggested that viral DNA would be folded compactly by the interaction with multiple P3 molecules, which would form tetramers, while being packaged into the capsid shell.
Prevalence of Maternal Cytomegalovirus (CMV) Antibody and Detection of CMV DNA in Amniotic Fluid
Authors: Nishimura Naoko , Kimura Hiroshi , Yabuta Yumi , Tanaka Naoko , Ito Yoshinori , Ishikawa Kaoru , Suzuki Chizuko , Morishima Tsuneo 
Published: November 2013

AbstractThe prevalence of cytomegalovirus (CMV) IgG antibody was determined in 573 pregnant women in the first trimester. The overall prevalence of CMV IgG antibody was 77.5%. The rate of seropositivity was 67.7% in women < 25 yr, and increased with age to 85.7% in women ≧40 yr. These results imply that young women in Japan are at increased risk for primary CMV infection during pregnancy and that congenital CMV infection rates might increase in the future. We conducted a prospective study of 75 pregnant women who underwent amniocentesis for various indications to determine if CMV DNA could be detected in the amniotic fluid. None had symptoms associated with CMV infection, CMV IgM antibody, or seroconversion to CMV IgG antibody during pregnancy. CMV DNA was not detected in the amniotic fluid using a polymerase chain reaction assay. The 65 fetuses, including 3 sets of twins, were followed through birth. CMV DNA was not detected in urine samples obtained within the first 2 weeks of life. In conclusion, CMV DNA was not detected in the amniotic fluid of women who did not have CMV infection. These results, however, suggest that the negative predictive value of prenatal amniotic fluid analysis is high and that the presence of CMV DNA in the amniotic fluid has clinical significance for the diagnosis of congenital CMV infection if detected in pregnant women.
Chemically Induced Infection of CD4‐Negative HeLa Cells with HIV‐1
Authors: Harada Shinji , Maeda Yosuke 
Published: November 2013

AbstractInfection with human immunodeficiency virus type‐1 (HIV‐1) requires the presence of a CD4 molecule and chemokine receptors such as CXCR4 or CCR5 on the surface of target cells. However, it is still not clear how the virus enters the cells. Although CD4 was initially identified as the primary receptor for HIV‐1, the expression of CD4 or one of the chemokine receptors alone is not sufficient to render susceptibility to infection with the virus. To ascertain whether or not adsorption of the virus needs charge‐to‐charge interaction between viral envelope and host cell membrane protein(s) and if binding alone promotes penetration of the virus into the cells, we have developed a chemically induced infection system targeting a CD4‐negative and CXCR4‐positive HeLa cell clone (N7 HeLa) which is usually not susceptible to infection with the LAI strain of HIV‐1. Use of a poly‐L‐lysine (PLL)‐coated culture plate to enhance the attachment of the virus to the cells made N7 HeLa cells infectable with HIV‐1 at very low efficiency. PLL alone cannot fully substitute for the function of the CD4 molecule. However, trypsin‐treated viruses, which have largely lost infectivity to CD4‐positive MT‐4 cells that are highly susceptible to HIV‐1 infection, enhanced infectivity against N7 HeLa cells when the PLL‐coated plate was used. These results provide evidence that infection with HIV‐1 requires both high binding affinity between viruses and cells, and then needs a modification of the viral envelope such as cleavage of gp120/160 to enhance the infection, probably resulting in exposure of the hydrophobic fusion domain of gp41. HIV‐1 infection of N7 HeLa cells was also enhanced by treatment with low pH, 12‐O‐tetradecanoylphorbol‐13‐acetate (TPA) and some factor(s) from the MT‐4 cell culture supernatant. Not only tight viral adsorption with cleavage of the viral envelope but also some activated status of the cells may be required for sufficient HIV‐1 infection in this artificial condition.
Porphyromonas gingivalis Fimbriae Induce Adhesion of Monocytic Cell Line U937 to Endothelial Cells
Authors: Hirose Kimiharu , Isogai Emiko , Ueda Itsuo 
Published: November 2013

AbstractThis study used the human monocytic cell line U937 to examine whether or not Porphyromonas gingivalis fimbriae could induce the adhesion of monocytes to endothelial cells. An in vitro adhesion assay was used to investigate the effects of the fimbriae on U937 cell adhesion to human umbilical vein endothelial cells (HUVEC). The fimbriae enhanced U937 cell adhesion to HUVEC in a dose‐dependent manner. U937 cells adhered better to HUVEC pretreated with the fimbriae for a minimum of 2 hr than to untreated HUVEC. The enhanced adhesion was inhibited by a monoclonal antibody against P. gingivalis 381 fimbriae. Pretreatment of U937 cells with the fimbriae for 24 hr enhanced U937 cell adhesion to HUVEC approximately 4‐fold. This phenomenon was inhibited by an anti‐CD11b antibody, suggesting the involvement of CD11b. These results indicate that P. gingivalis fimbriae can induce monocyte adhesion to the endothelial cell surface. They also suggest that the fimbriae may be involved in the initial event for infiltration of monocytes into the periodontal tissues of individuals with adult periodontitis.
Effect of Antibiotics, Levofloxacin and Fosfomycin, on a Mouse Model with Escherichia coli O157 Infection
Authors: Isogai Emiko , Isogai Hiroshi , Hayashi Shunji , Kubota Toru , Kimura Koichi , Fujii Nobuhiro , Ohtani Tsuyoshi , Sato Kenichi 
Published: November 2013

AbstractThere have been some reservations about the treatment of enterohemorrhagic Escherichia coli (EHEC) infection with antibiotics to prevent the occurrence of hemolytic uremic syndrome (HUS). However, the administration of antimicrobial agents for EHEC infection is under discussion. Therefore, we used an experimental mouse model to assess the advantage/disadvantage of two major antibiotics, levofloxacin (LVFX) and fosfomycin (FOM). Germ‐free IQI mice were inoculated with EHEC O157 strain EDL931 or #7. Bacteria colonized feces at 109–1010 CFU/g, and Shiga toxins (STXs) were detected in the feces. From 1 day after infection, mice were assigned to LVFX (20 mg/kg) once daily or FOM (400 mg/kg) once daily. A significant decrease in overall mortality was observed after treatment of LVFX, with EHEC disappearing immediately from the feces of mice. FOM also reduced mortality for one strain, the STX level decreased gradually. LVFX exhibited higher therapeutic efficacy than FOM. Strain differences were observed in the model during the treatment.
Induction of High Levels of Epitope‐Specific Antibodies by Epitope/Peptide Candidate Vaccines against Human Immunodeficiency Virus Type‐1 (HIV‐1)
Authors: Yu Tianwei , Bai Yun , Dierich Manfred P. , Chen Ying‐Hua 
Published: November 2013

AbstractTo test the immunogenicity of GPGRAFY‐epitope‐based candidate vaccines, a peptide with four repetitive GPGRAFY epitopes, V3‐P1 [C‐(GPGRAFY)4], and a peptide (PND) of the principal neutralizing domain (V3 loop: amino acid 301–328: C‐TRPNNNTRKSIRIQRGPGRAFYTIGKI) on gp120 were synthesized and covalently coupled to a carrier protein BSA. Immunization of BALB/c mice and New Zealand White Rabbits with these conjugate vaccines engendered strong antibody responses against the PND (mouse serum titer by 1:12,800–25,600; rabbit serum titer by 1:6,400–12,800). Interestingly, the V3‐P1‐BSA conjugates and the PND‐BSA conjugates could induce high levels of GPGRAFY‐epitope‐specific antibodies in the mice and rabbits (mouse serum titer by 1:25,600; rabbit serum titer by 1:12,800–25,600), while a recombinant gp160 subunit vaccine induced a low level of GPGRAFY‐epitope‐specific antibodies (serum titer by 1:400–1,600 in mice and rabbits). To confirm the above results, GPGRAFY‐epitope‐specific antibodies were isolated from rabbit sera induced by V3‐P1‐BSA, PND‐BSA conjugates and rgp160 vaccine. In fact, 23–38 and 13–22 μg epitope‐specific antibodies per milliliter serum were isolated from rabbit sera induced by V3‐P1‐BSA and PND‐BSA conjugate, respectively, while 1.34 μg epitope‐specific antibodies per milliliter serum were identified in rabbit serum induced by rgp160 vaccine. In the control group, only 0.069 μg proteins per milliliter serum were found in pooled pre‐immune serum (normal serum). These results from mouse and rabbit experiments indicate that epitope and peptide vaccines both induce high levels of GPGRAFY‐epitope‐specific antibodies in comparison with rgp160 subunit vaccine, suggesting that epitope/peptide vaccines may be a new strategy to induce protective activity.
Exposure of Normal Monocyte‐Derived Dendritic Cells to Human Immunodeficiency Virus Type‐1 Particles Leads to the Induction of Apoptosis in Co‐Cultured CD4+ as Well as CD8+ T Cells
Authors: Suzuki Satoko , Tobiume Minoru , Kameoka Masanori , Sato Katsuaki , Takahashi Tsuneo A. , Mukai Tetsu , Ikuta Kazuyoshi 
Published: November 2013

AbstractThe depletion of immune T cells by human immunodeficiency virus type‐1 (HIV‐1) infection is a major mechanism involved in the pathogenesis of AIDS. Here, we examined a possible effector function of blood monocyte‐derived dendritic cells (DCs) to induce apoptosis in bystander CD4+ and CD8+ T cells. The DCs were generated by culturing monocytes in the presence of granulocyte‐macrophage colony‐stimulating factor and interleukin‐4. The DCs exposed to HIV‐1 particles were co‐cultured with healthy donor‐derived blood T cells at a ratio of 1:20. Analyses by percent cell mortality, staining with propidium iodide and reactivity with Annexin V revealed the induction of apoptosis in both CD4+ and CD8+ target T cells. Further, this apoptosis occurred without stimulation with mitogens when the cell cycle of target T cells shifted from G0 to G1, probably due to the mitogenic effect of the DCs. Thus, induction of apoptosis in both CD4+ and CD8+ T cells occurred via interaction with DCs adsorbed with HIV‐1 particles.
SDF‐1 Has Costimulatory Effects on Human T Cells
Authors: Yonezawa Akihito , Hori Toshiyuki , Sakaida Hitoshi , Uchiyama Takashi 
Published: November 2013

AbstractStromal cell‐derived factor‐1 (SDF‐1) is an efficacious chemoattractant for lymphocytes, monocytes and hematopoietic progenitor cells. In the present study, we examined whether SDF‐1 has growth promoting activity on human peripheral T cells and analyzed the possible underlying signal transduction pathways. SDF‐1 augmented the proliferation of anti‐CD3‐ or PHA‐stimulated normal human PBMC in a dose‐dependent manner but not that of resting PBMC. It was noted that SDF‐1 alone could induce a significant proliferation of PHA‐preactivated T cells. Anti‐SDF‐1 sera could inhibit the augmentation of T‐cell proliferation in each experiment. Furthermore, Western blot analysis revealed that mitogen‐activated protein kinase (MAPK)/extracellular signal‐regulated kinase 2 (ERK2), but not c‐Jun N‐termimal kinase (JNK) was activated by SDF‐1. Considering that costimulatory signals have been reported to involve ERK2 activation, these results indicate that SDF‐1 has costimulatory effects on T cells that are possibly mediated by ERK2 activation and may play a role in not only migration but also the potentiation or maintenance of T cells.
In Vitro Susceptibility of 7.5‐kb Common Plasmid‐Free Chlamydia trachomatis Strains
Authors: Miyashita Naoyuki , Matsumoto Akira , Matsushima Toshiharu 
Published: November 2013

AbstractUsing a new plaque cloning technique, we obtained unique Chlamydia trachomatis strains which were confirmed to be free of the 7.5‐kb common plasmid and glycogen in inclusions. The in vitro susceptibility of these strains to various chemotherapeutic agents was tested by comparison with their parent strains and clinical isolates possessing the common plasmid. No difference was detected for any of the agents tested, indicating that the 7.5‐kb common plasmid is unrelated to the drug resistance of C. trachomatis.
Identification of a Two‐Component Signal Transduction System Involved in Fimbriation of Porphyromonas gingivalis
Authors: Hayashi Jun‐ichiro , Nishikawa Kiyoshi , Hirano Risa , Noguchi Toshihide , Yoshimura Fuminobu 
Published: November 2013

AbstractPorphyromonas gingivalis, a periodontopathogen, is an oral anaerobic Gram‐negative bacterium with numerous fimbriae on the cell surface. Fimbriae have been considered to be an important virulence factor in this organism. We analyzed the genomic DNA of transposon‐induced, fimbria‐deficient mutants derived from ATCC 33277 and found that seven independent mutants had transposon insertions within the same restriction fragment. Cloning and sequencing of the disrupted region from one of the mutants revealed two adjacent open reading frames (ORFs) which seemed to encode a two‐component signal transduction system. We also found that six of the mutants had insertions in a gene, fimS, a homologue of the genes encoding sensor kinase, and that the insertion in the remaining one disrupted the gene immediately downstream, fimR, a homologue of the response regulator genes in other bacteria. These findings suggest that this two‐component regulatory system is involved in fimbriation of P. gingivalis.
Burkholderia uboniae Sp. Nov., l‐Arabinose‐Assimilating but Different from Burkholderia thailandensis and Burkholderia vietnamiensis
Authors: Yabuuchi Eiko , Kawamura Yoshiaki , Ezaki Takayuki , Ikedo Masanari , Dejsirilert Surang , Fujiwara Nagatoshi , Naka Takashi , Kobayashi Kazuo 
Published: November 2013

AbstractA polar multitrichous Gram‐negative motile rod, EY 3383, originally identified as Burkholderia thailandensis, revealed a DNA‐DNA reassociation rate of 36.7%, under stringent conditions, with the type strain of B. thailandensis, despite the 16S rDNA homology value between two type strains being as high as 97.9%. The strain was clearly differentiated from the type strain of B. thailandensis by physiological, biochemical, and nutritional characteristics, without significant difference in cellular fatty acid and lipid composition. Based on the results of 16S rDNA sequence analysis, DNA‐DNA hybridization and phenotypic characterization, Burkholderia uboniae sp. nov. is herein proposed. The type strain is NCTC 13147=EY 3383, isolated on 8 December 1989 from surface soil along the roadside in Ubon Ratchathani, Thailand. Major respiratory quinone is ubiquinone‐8(Q8). G+C content of DNA is 69.71%.
Protective Effect of C‐Reactive Protein against the Lethality Induced by Vibrio vulnificus Lipopolysaccharide
Authors: Chae Mee‐ree , Park Byung‐hyun , Kim Jong‐suk , Rho Hye‐won , Park Jin‐woo , Kim Hyung‐rho 
Published: November 2013

AbstractVibrio vulnificus infection has attracted special interest because of its high mortality. A strong clinical association exists between hepatic dysfunction and increased morbidity and mortality from V. vulnificus infection. In this study, the effect of C‐reactive protein (CRP), a typical hepatogenic acute phase protein, on the lethality induced by V. vulnificus lipopolysaccharide (LPS) was investigated in galactosamine‐sensitized mice. The pretreatment of CRP, in a dose of at least 2 mg/kg, 2 hr before the challenge of LPS completely protected mice against the lethality by V. vulnificus LPS. The elevation of serum tumor necrosis factor‐α (TNF‐α) induced by LPS administration was not affected by CRP pretreatment. However, the LPS‐ or TNF‐α‐induced hepatotoxicity was completely prevented by CRP. These results indicate that CRP does not prevent the synthesis, but prevents the hepatotoxic action of TNF‐α. The possibility that impaired production of acute phase proteins in patients with pre‐existing hepatic dysfunction may predispose the higher risk of V. vulnificus infection needs to be evaluated further.
Mutation of Aromatic Amino Acid Residues Located at the Amino‐ and Carboxy‐Termini of Escherichia coli Heat‐Stable Enterotoxin Ip Reduces the Efficiency of the Toxin to Cross the Outer Membrane
Authors: Yamanaka Hiroyasu , Okamoto Keinosuke 
Published: November 2013

AbstractHeat‐stable enterotoxin Ip (STIp) of Escherichia coli is synthesized as a precursor form consisting of pre‐ (amino acid residues 1 to 19), pro‐ (amino acid residues 20 to 54) and mature (amino acid residues 55 to 72) regions. Mature STIp (bioactive STIp) is formed in the periplasmic space after the precursor is proteolytically processed and the mature STIp translocates across the outer membrane through the secretory system including TolC, an outer membrane protein of E. coli. However, it remains unknown how the mature STIp is recognized by this secretory system. In this study, we investigated the amino acid residues of STIp involved in its translocation across the outer membrane. We prepared mutant STIp genes by site‐directed mutagenesis and analyzed translocation of the mutant STIps across the outer membrane. Deletion of the Phe or Tyr residue at position 3 or 18, respectively, decreased the efficiency of translocation of STIp across the outer membrane. To confirm the involvement of these amino acid residues, we further mutated the codons for these amino acid residues to that for Gly. These mutations also decreased the efficiency of extracellular secretion of STIp. In contrast, substitution of Phe‐3 and Tyr‐18 with Tyr and Phe, respectively, did not affect the efficiency of translocation of the toxin. These results indicated that the aromatic amino acid residues at positions 3 and 18 in the mature region are important for the ability of STIp to cross the outer membrane.
The Relative Frequencies of G Serotypes of Rotaviruses Recovered from Hospitalized Children with Diarrhea: A 10‐Year Survey (1987–1996) in Japan with a Review of Globally Collected Data
Authors: Koshimura Yumi , Nakagomi Toyoko , Nakagomi Osamu 
Published: November 2013

AbstractSince rotavirus vaccines aim to protect children from severe diarrhea, knowledge of the prevailing G serotypes among rotaviruses from hospitalized children is essential. Thus, we determined the G serotypes of rotaviruses collected from children with acute diarrhea in a local referral hospital in Akita, Japan, over the 10‐year period between January 1987 and December 1996. Based on the assumption that rotaviruses with an identical electropherotype possess the same G serotype, the G serotypes of 488 rotavirus‐positive specimens that were classified into 63 electropherotypes were determined by enzyme‐linked immunosorbent assay with a supplementary use of G typing by reverse transcription‐PCR. The relative frequencies over the 10‐year period were 77.0 (G1), 14.5 (G2), 2.7 (G3) and 5.3% (G4), leaving the possibility that only 0.4% had G serotypes uncommon to human rotaviruses. Of 24,050 rotaviruses extracted by reviewing 63 serotyping studies in literature, the relative frequencies of the four major G serotypes were 50.6 (G1), 9.3 (G2), 7.2 (G3) and 11.6% (G4). As to uncommon G serotypes, only 0.9% were described as serotypes other than G1–4, and our estimate for potential uncommon serotypes were at most 8.1%. Thus, both this long‐term study focusing on the rotaviruses only from severe cases in a single hospital in Japan and the global review of G serotypes published to date indicate that the primary target of any rotavirus vaccines should be rotaviruses possessing serotypes G1–4.
Sensitive Enzyme‐Linked Immunosorbent Assays for the Detection of Bacterial Superantigens and Antibodies against Them in Human Plasma
Authors: Miwa Keishi , Fukuyama Mayumi , Sakai Rumiko , Shimizu Shinji , Ida Nobuo , Endo Miyoko , Igarashi Hideo 
Published: November 2013

AbstractEnzyme‐linked immunosorbent assays for the quantitation of bacterial superantigens, staphylococcal enterotoxins A, B and C, toxic‐shock syndrome toxin‐1 and streptococcal pyrogenic exotoxin A, were developed. The assays had sensitivity to quantitate these toxins to 1.4, 5.9, 16.3, 2.5 and 4.3 pg/ml, respectively, in a buffer including 50% human plasma. It takes only 150 min to complete the assays after plate preparation. Specificity of the assays agreed with those of reverse latex agglutination assay. We also developed enzyme‐linked immunosorbent assays to detect antibodies against these five superantigens. The assays are expected to be significant tools for the study of superantigens in several diseases.
Characterization of Monoclonal Antibodies against Hokkaido Strain Tick‐Borne Encephalitis Virus
Authors: Komoro Kimiyo , Hayasaka Daisuke , Mizutani Tetsuya , Kariwa Hiroaki , Takashima Ikuo 
Published: November 2013

AbstractA tick‐borne encephalitis (TBE) patient was found in Hokkaido in 1993, and TBE viruses were isolated from animals and ticks in our previous studies. To develop a diagnostic reagent to identify TBE viruses, monoclonal antibodies (Mabs) were produced against the TBE virus strain Hokkaido (Oshima 5–10). Seven Mabs were obtained which reacted with the envelope protein of the Oshima 5–10 strain. These Mabs were flavivirus genus‐specific, TBE virus complex‐specific or TBE virus type‐specific. The Mabs are applicable for identification of TBE virus strains.