bluuebunny/crossref_metadata_2025 huggingface dataset:
Differential toxic effects of lactate and acetate on the metabolism of Streptococcus mutans and Streptococcus sanguis
Authors: Carlsson J. , Hamilton I.R.
Published: December 2007

Experiments were conducted with Streptococcus mutans NCTC 10449 and Streptococcus sanguis ATCC 10556 to determine whether the acid end‐products, lactate and acetate, were involved in the regulation of cellular growth and metabolism. The growth rate and culture biomass of both organisms was inhibited by the addition of lactate and acetate at concentrations as high as 200 mM to the cultures, although the final pH values of the lactate and acetate cultures were similar. In addition, the metabolic conversion of glucose to lactate was decreased by external lactate but stimulated by acetate. In spite of this, calculation of the yield of cell biomass per mole of ATP (YATP) showed that the yield of both organisms actually increased in the presence of added lactate, but decreased with acetate. This indicates that the two acids interacted with the cells of the organisms by different mechanisms. For both organisms, the final external undissociated lactic acid was relatively constant at concentrations between 0 and 200 mM added lactate, 24.9–32.5 mM for S. mutans and 8.0‐11.5 mM for S. sanguis. On the other hand, the final concentration of undissociated acetic acid in the S. mutans cultures increased from 2.9 to 83.7 mM as the medium acetate concentration increased, and from 1.0 to 36.0 mM with the S. sanguis cultures. Counterflow experiments provided evidence for a lactate carrier in both S. mutans and S. sanguis, but an acetate carrier in these organisms could not be demonstrated. [14C]‐lactate and [14C]‐acetate were taken up into de‐energized, chemostat‐grown cells of S. mutans and S. sanguis in response to an artificially generated pH gradient but not by an imposed electrical gradient. Thus, under these conditions lactate uptake occurred via a symport process with only one proton. Growth of both organisms in the presence of increasing concentrations of acetate resulted in a small reduction (27%) in the transmembrane pH gradient (ΔpH) as measured by the permeant acid, [14C]‐salicylate. However, the uptake of [14C]‐acetate for the estimation of ΔpH revealed significant inhibition of the acetate concentration gradient in the presence external acetate, indicating that the cells expelled the acetate anion. The results indicate that, unlike acetate uptake, lactate transport by S. mutans and S. sanguis was strictly regulated via the lactate earner in order to prevent excessive dissipation of the pH gradient. Clearly, the formation of acetate by oral streptococci is more problematic for cellular homeostasis than the formation of lactate.
Inhibition of nuclear factor kappa B subunit p65 mRNA accumulation in lipopolysaccharide‐stimulated human monocytic cells treated with sodium salicylate
Authors: Tokashiba S. , Van Dyke T. E. , Amar S.
Published: December 2007

Lipopolysaccharide is one of the most potent trigger substances for monocytes and macrophages causing secretion of inflammatory mediators such as tumor necrosis factor and interleukin‐1. The nature of the nuclear factors involved in regulation of these cytokine genes is still unknown. Nuclear factor kappa B (NF‐κB: heterodimer of p50 and p65) proteins have been suggested to play an important role in gene transcription of inflammatory mediators when monocytes are stimulated with lipopolysaccharide. Nonsteroidal anti‐inflammatory drugs such as salicylates have been used to treat symptoms of inflammation, and a new mechanism of drug action was suggested recently. Salicylates have been shown to inhibit lipopolysaccharide‐induced gene transcription via inhibition of NF‐κB activation by preventing the degradation of NF‐κB inhibitor “IκB”, blocking the translocation of NF‐κB into the nuclear compartment. However, the nature of the subunit involved in this mechanism has not been defined. To examine the mechanisms by which salicylates affect cytokine gene transcription, the amount of active and inactive NF‐κB and NF‐κB mRNA, in Porphyromonas gingivalis lipopolysaccharide‐stimulated human monocytic cells was assessed. High doses of sodium salicylate suppressed NF‐κB p65 mRNA accumulation, resulting in suppression of total NF‐κB. p50 on tissue oligonucleotide had no effects on lipopolysaccharide‐induced NF‐κB activation. The data demonstrate that the p65 subunit of NF‐κB is inhibited by salicylate treatment and highlight the role of salicylate in the control of gene expression of inflammatory mediators.
Immunochemical characterization of the carbohydrate antigens of serotype k and Lancefield group G “Streptococcus milleri”
Authors: Kitada K. , Inoue M.
Published: December 2007

Carbohydrate antigens of the serotype k/Lancefield group G “Streptococcus milleri” were extracted by autoclaving whole cells of the type k reference strain Streptococcus anginosus K214‐2K. The type k and group G antigen molecules are separated from each other and partially purified by a DEAE‐Sephadex A‐25 column chromatography followed by a Sephadex G‐100 gel filtration. In the double diffusion and the immunoelectrophoresis, the type k and group G antigen preparations obtained yielded single bands with their homologous antisera respectively. The type k antigen preparation contained principally glycerol, rhamnose, ribitol, galactose and glucose in a molar ratio of 0.54:1.20:0.43:0.33:1.00. The quantitative precipitin inhibition test indicated that β(l‐6)glucosyl‐glucose (gentiobiose) sequence played a major role in immunodeterminant structure. Thus, the type k antigen of “S. milleri” appears to be a new carbohydrate type antigen that is chemically different from any Ottens type antigen. In contrast, the group G antigen preparation contained high proportion of rhamnose in addition to glucose, N‐acetylglucosamine and N‐acetylgalactosamine in a molar ratio of 6.45:1.00:0.24:1.15, and the rhamnose residue was involved in the immunodominant epitope, being in good agreement with the previously proposed chemical structure of the group antigen.
Inhibition of adherence of Actinomyces naeslundii (Actinomyces viscosus) T14V‐J1 to saliva‐treated hydroxyapatite by a monoclonal antibody to type 1 fimbriae
Authors: Nesbitt W. E. , Beem J. E. , Leung K‐P. , Stroup S. , Swift R. , McArthur W. P. , Clark W. B.
Published: December 2007

A monoclonal antibody to Actinomyces naeslundii (A. viscosus) T14V‐J1 type 1 fimbriae, capable of inhibiting the adherence of this bacterium to salivary proline‐rich protein‐treated hydroxyapatite, was generated by immunization of SWR mice with A. naeslundii 55–19, a strain derived from T14V‐J1 that possesses only type 1 fimbriae. Supernatants of hybridomas were screened for reactivity with purified type 1 fimbriae. An IgG monoclonal antibody, 86–49E, blocked the adsorption of the parent strain to proline‐rich protein‐treated hydroxyapatite by 77% with 1.0 μg/ml of the monoclonal antibody; the Fab fragment derived from this monoclonal antibody inhibited adherence by 38% at the same concentration. Similarly, the adherence of strain 55‐19 was inhibited by 100% and 64% to proline‐rich protein‐treated hydroxyapatite with 1.0 μg/ml of IgG and Fab fragments respectively. Control monoclonal antibody to the subunit of type 1 fimbriae, as well as to Actinobacillus actinomycetemcomitans caused only minimal adherence inhibition. Monoclonal antibody 86‐49E also agglutinated both type 1 fimbriae bearing strains of A. naeslundii T14V‐J1 and 55‐19 but not strains 59‐51 and 147, which lack type 1 fimbriae. Further confirmation of the specificity of monoclonal antibody 86‐49E was obtained using these fimbria deficient mutant strains in an enzyme‐linked immunosorbent assay, with the monoclonal antibody binding only to strains possessing type 1 fimbriae. Immunogold labeling in conjunction with electron microscopy suggested binding of monoclonal antibody 86‐49E occurring near the distal end of the fimbriae. In contrast, when a monoclonal antibody specific for the type 1 fimbrial subunit but not capable of adherence inhibition was used together with 86‐49E in double‐labeling experiments, extensive labeling of the fimbriae by the subunit antibody was noted. These data suggest that a monoclonal antibody specific for the type 1 fimbriae of A. naeslundii that is capable of binding to a discrete site on the fimbriae has the capacity to inhibit the adsorption of this organism to saliva‐treated hydroxyapatite.
Inductive effect of Porphyromonas gingivalis fimbriae on differentiation of human monocytic tumor cell line U937
Authors: Hirose K. , Isogai E. , Mizugai H. , Miura H. , Ueda I.
Published: December 2007

This study used the human monocytic tumor cell line U937 to examine whether Porphyromonas gingivalis fimbriae induce differentiation of monocyte/macro‐phage progenitors. When the progenitor cells were incubated with P. gingivalis fimbriaè, the incubation resulted in increased Fc rosette formation and increased CDllb production by the cells. The presence of a protein kinase C inhibitor, H7 or calphostin C, in the medium eliminated the stimulatory effects of P. gingivalis fimbriae on Fc rosette formation. Furthermore, CD11b expression was inhibited by calphostin C. In contrast, HA1004, an inhibitor of cyclic nucleotide‐dependent protein kinase, had no effect on P. gingivalis fimbriae‐induced Fc rosette formation or CD11b expression. These results demonstrate that P. gingivalis fimbriae are a potent inducer of the differentiation of the monocyte/macrophage tumor cell line U937, most probably via cyclic nucleotide‐independent protein kinase C.
Identification and characterization of a protease from Streptococcus oralis C104
Authors: Lo C. S. , Hughes C. V.
Published: December 2007

Streptococcus oralis is among the earliest colonizers of the tooth surface during plaque formation. As such, its enzymatic activities may influence ecologic succession on the tooth surface. In the current study, we used zymograms and preparative polyacrylamide gel electrophoresis to identify and purify a protease from S. oralis (sanguis) C104. Proteases from 5. oralis C104 were detected in cell pellets at 133, 146 and 176 kDa as clear proteolytic bands on gelatin‐substrate zymograms. Preparations of the major (146 kDa) protease were obtained by continuous‐elution electrophoresis. The protease was active over the pH range of 7 to 9 with optimum activity between pH 8 and 9. Protease activity was inhibited by several serine protease inhibitors including phenylmethylsulfonyl fluoride, di‐iso‐propyl‐phosphofluoridate and aprotinin. The protease showed highest hydrolytic activity against azoalbumin and Bz‐Pro‐Phe‐Arg‐NA. Immunofluorescence studies with a polyclonal antiserum to the 146–kDa protease suggest it is present on the cell surface of S. oralis C104. Zymograms of cell pellets from other S. oralis strains as well as S. sanguis and Streptococcus mitis suggest that functionally similar proteases are elaborated by many early colonizers of the tooth surface.
Detection frequencies and the colony‐forming unit recovery of oral treponemes by different cultivation methods
Authors: Koseki T. , Benno Y. , Zhang‐Koseki Y. J. , Umeda M. , Ishikawa I.
Published: December 2007

Selected media were compared for primary isolation and detection of oral treponemes from clinical samples. Forty‐eight subgingival plaque samples from 45 patients suffering from periodontitis were anaerobically cultivated for 2 weeks at 37°C. Of the 9 media studied, Medium 10 (M10), which was supplemented with 10% rabbit serum and incubated using the plate‐in‐bottle method, supported the highest colony‐forming units of the anaerobes. The treponemal colonies were detected at least on one medium from 83% of the subgingival plaque samples. The new oral spirochete medium in an anaerobic chamber supported the highest detection frequency of the oral treponemes (64% of samples); however, M10 in the plate‐in‐bottle was found to produce the highest colony‐forming unit recovery of the oral treponemes (median 3.6% of the total colony‐forming units). This study suggests that M10 in the plate‐in‐bottle and new oral spirochete medium in the anaerobic chamber are essential in cultivating oral treponemes.
Chemical and biological properties of lipopolysaccharide from Selenomonas sputigena ATCC 33150
Authors: Kumada H. , Watanabe K. , Nakamu A. , Haishima Y. , Kondo S. , Hisatsune K. , Umemoto T.
Published: December 2007

Chemical and biological studies were performed on lipopolysaccharide isolated from Selenomonas sputigena ATCC 33150T, a possible causative agent of periodontal diseases. The sugar components of the lipopolysaccharide of S. sputigena were mannose, galactose, glucose, l‐glycero‐d‐mannoheptose (heptose), 2‐keto‐3‐deoxy‐octonic acid, glucosamine and galactosamine in a molar ratio of 0.3:1.0:1.0:1.0:0.2: 3.0:3.2 (mol/mol heptose). Sephadex G‐50 chromatography of the polysaccharide portion of the lipopolysaccharide obtained by partial hydrolysis yielded three fractions: the O‐polysaccharide chain attached to the core oligosaccharide, the core oligosaccharide and monosaccharides. Compositional analysis of these fractions revealed that lipopolysaccharide of S. sputigena carries a short O‐polysaccharide chain consisting of galactose and glucosamine and that the core oligosaccharide consisted of glucose, heptose, glucosamine and 2‐keto‐3‐deoxyoctonic acid. It is of particular interest that galactosamine was detected as a component sugar of the lipid A moiety in addition to glucosamine, which is a usual component sugar of the lipid A of most gram‐negative bacteria. Thus, the lipid A of S. sputigena might have a unique backbone that differs from that of the lipid A of other gram‐negative bacteria. Lipid A of S. sputigena consisted mainly of fatty acids such as undecanoic, tridecanoic, tridecenoic, 3‐hydroxytridecanoic and 3‐hydroxytetradecanoic acid in a molar ratio of 0.4:1.0:0.3:4.0:0.5 (mol/mol tridecanoic acid). Lipopolysaccharide and lipid A from S. sputigena both exhibited biological activity in activating the clotting enzyme of Limulus amebocytes, the Schwartzman reaction, mitogenicity for murine lymphocytes and in inducing interleukin‐la and interleukin‐6 production in murine macrophages to the same extent as those observed for lipopolysaccharide of the Salmonella serovar typhimurium used as a positive control. The results suggested that the lipopolysaccharide of S. sputigena is a virulent factor in human periodontal diseases.
Coaggregation of Candida albicans with oral Fusobacterium species
Authors: Grimaudo N. J. , Nesbitt W. E.
Published: December 2007

Nine strains of oral Fusobacterium were examined for their ability to coaggregate in vitro with four strains of the oral yeast, Candida albicans. All of the Fusobacterium nucleatum strains and Fusobacterium periodontium and Fusobacterium sulci coaggregated to various degrees with all of the Candida strains. Fusobacterium alocis, Fusobacterium mortiferum and Fusobactrium simiae strains did not coaggregate with any of the Candida strains. Exposure of the coaggregating Fusobacterium strains but not the Candida strains to heat, trypsin, and proteinase K eliminated Coaggregation. Amphotericin B or trichodermin treatment of the yeast species had no effect. The reactions were inhibited by addition of 0.1 M mannose, glucosamine and α‐methyl mannoside. All coaggregating pairs were disaggregated by the addition of sodium dodecyl sulfate, but nonionic detergents had no effect. The addition of 2.0 M urea completely reversed Coaggregation. Candida strains were sensitive to periodate oxidation, whereas the Fusobacterium strains were stable to this treatment. All coaggregations occurred in the presence of saliva and appeared stronger than in buffer. These data suggest that the coaggregations involve either a protein or glycoprotein on the Fusobacterium surface, which may interact with carbohydrates or carbohydrate‐containing molecules on the surface of the Candida. These observations expand the known range of intergeneric coaggregations occurring between human oral microbes and indicate that Coaggregation of C. albicans and Fusobacterium species may be an important factor in oral colonization by this yeast. The authors believe this to be the first description of Coaggregation concerning a carbohydrate component on the yeast cell and a protein component on the oral bacterial cell.
Immunoglobulin A reaction to oral streptococci in saliva of subjects with different combinations of caries and levels of mutans streptococci
Authors: Bratthall D. , Serinirach R. , Hamberg K. , Widerström L.
Published: December 2007

The aim of this study, performed in Bangkok, was to study whether a particular salivary immunoglobulin A (IgA) antibody profile against mutans streptococci could be related to the absence or presence of caries. A group of 12‐year‐old individuals representing various combinations of mutans streptococci levels and caries experience was selected. Whole saliva stimulated by paraffin‐chewing was collected, and the children were investigated for decayed, missing and filled surfaces (DMFS) and teeth (DMFT), following WHO criteria and methods, at baseline and after 2 years. The total amount of salivary IgA was determined by an immunobead enzyme‐linked immunosorbent assay, and SDS‐PAGE and Western blot analysis was performed using sonicated antigens of Streptococcus mutans and Streptococcus sobrinus strains and, as a control, a Streptococcus parasanguis strain. The results showed that Thai children with low caries prevalence had more distinct immunoblot bands to antigens from mutans streptococci than did the high‐caries children. A similar picture was not seen for S. parasanguis. On the whole, the Thai children also showed fewer bands than usual Swedish saliva samples from comparable age groups. The complexity of the relationship between dental caries and IgA in saliva is highlighted.
Transcriptional analysis of the groESL operon from Porphyromonas gingivalis
Authors: Hotokezaka H. , Ohara N. , Hayashida H. , Matsumoto S. , Matsuo T. , Naito M. , Kobayashi K. , Yamada T.
Published: December 2007

Transcriptional analysis of the groESL operon from Porphyromonas gingivalis, one of the obligative anaerobic oral microorganisms implicated in adult periodontitis, was performed. P. gingivalis 381 cultured at 37°C was shifted to 42°C, 45°C or 48°C for 10 mins. Northern hybridization analysis revealed that a band with 2.1‐kb (kilo base pair) was observed, and the transcripts increased greatly by heat shock. Primer extension and S1 mapping detected four different 5′‐ending sites of the mRNAs at the upstream region of the groES. Three sites out of the four were heat‐inducible. There were inverted repeats and a Escherichia coliσ32‐recognizing consensus sequence in the promoter region of the groESL, which may be relevant to the regulation of transcription of groESL operon in P. gingivalis. Both a heat shock promoter and inverted repeats may be relevant to the transcriptional regulation of the groESL operon in P. gingivalis.
Characterization of protease activities in Capnocytophaga spp., Porphyromonas gingivalis, Prevotella spp., Treponema denticola and Actinobacillus actinomycetemcomitans
Authors: Gazi M. I. , Cox S. W. , Clark D. T. , Eley B. M.
Published: December 2007

Protease activities in cell sonicates of denned bacterial strains were examined using peptide substrates and class‐specific inhibitors. Capnocytophaga spp. all produced serine dipeptidyl peptidase activity and arginine/lysine, elastase‐ and chymotrypsin‐like enzymes with some metalloprotease characteristics. The elastase‐like activity was strongest in Capnocytophaga sputigena, but the others were greatest in Capnocytophaga gingivalis. The latter also had a separate arginine‐specific enzyme which appeared not to be present in the other two species. Porphyromonas gingivalis showed serine dipeptidyl peptidase activity and very strong arginine and lysine cysteine protease activities. Prevotella spp. had inhibitor‐resistant dipeptidyl peptidase activity and arginine cysteine protease activity that was much weaker but biochemically similar to P. gingivalis. Treponema denticola possessed a strong trypsin‐like serine protease activity as well as very weak dipeptidyl peptidase and chymotrypsin‐like activities that were sensitive to some cysteine protease reagents. Actinobacillus actinomycetemcomitans showed a novel ala‐nine‐ and lysine‐specific activity, but its nature was unclear.
Human Herpesviridae in acute necrotizing ulcerative gingivitis in children in Nigeria
Authors: Contreras A. , Falkler W.A. , Enwonwu C.O. , Idigbe E.O. , Savage K.O. , Afolabi M.B. , Onwujekwe D. , Rams T. E. , Slots J.
Published: December 2007

Herpesviruses have been implicated in the pathogenesis of human periodontitis. The present study investigated whether herpeasviruses are present in the lesions of acute necrotizing ulcerative gingivitis. Sixty‐two Nigerian children, aged 3–14 years, were studied. Twenty‐two children had acute necrotizing ulcerative gingivitis and were also malnourished, 20 exhibited no acute necrotizing ulcerative gingivitis but were malnourished, and 20 were free of acute necrotizing ulcerative gingivitis and in a good nutritional state. Polymerase chain reaction methods were used to determine the presence of human cytomegalovirus (HCMV), Epstein‐Barr virus type 1 and type 2 (EBV‐1, EBV‐2), herpes simplex virus (HSV), human herpes virus 6 (HHV‐6), human papilloma virus and human immunodeficiency virus type 1 in crevicular fluid specimens collected by paper points. Of the 22 acute necrotizing ulcerative gingivitis patients, 15 (68%) revealed viral infection and 8 (36%) viral coinfection. Thirteen (59%) acute necrotizing ulcerative gingivitis patients demonstrated HCMV, 6 (27%) EBV‐1, 5 (23%) HSV and 1 (5%) HHV‐6. Only 2 (10%) subjects from each group not affected by acute necrotizing ulcerative gingivitis showed viral presence, and no control subject revealed viral coinfection. These findings suggest that HCMV and possibly other herpesviruses contribute to the onset and/or progression of acute necrotizing ulcerative gingivitis in malnourished Nigerian children.
Estimation of serum antibody to subgingival species using checkerboard immunoblotting
Authors: Sakellari D. , Socransky S.S. , Dibart S. , Eftimiadi C. , Taubman M.A.
Published: December 2007

Measurement of serum antibody to subgingival bacterial species has been useful in discriminating possible periodontal pathogens and in assessing the host's immune response to subgingival species. An immunoassay system was developed to measure the level of serum antibody to multiple subgingival species in multiple serum samples on a single nitrocellulose membrane. The principle steps of the assay are the following: 1) binding of antigens from bacterial preparations and protein A in parallel lanes on nitrocellulose membranes; 2) incubation of known concentrations of human immunoglobulin as well as various dilutions of serum from patients in lanes perpendicular to the antigen lanes; 3) incubation of the membrane with a peroxidase‐conjugated second antibody; 4) detection of positive reactions by enhanced chemilurninescence. Emitted light was captured on a photographic film in which the positive reactions appeared as squares at the intersections of antigens with appropriate antibody. Antibody was quantified using a laser densitometer to compare the signal intensity of unknown samples with the ones generated by known amounts of human immunoglobulin captured on the same membrane. The assay permitted simultaneous screening and/or quantification of antibody in as many as 45 serum samples against up to 45 bacterial species. The mean and standard error of the coefficients of variation for replicates within an assay averaged 7.3±2.3%. Coefficients of variation of the assay run on different days for serum antibody to a range of subgingival species averaged 10.1 ±2.1%. Checkerboard immunoblotting is a simple and rapid immunoassay to permit quantification and/or screening of antibody to multiple subgingival species or antigens in multiple serum samples.
Evaluation of root canal bacteria and their antimicrobial susceptibility in teeth with necrotic pulp
Authors: Le Goff A. , Bunetel L. , Mouton C. , Bonnaure‐Mallet M.
Published: December 2007

This study aimed to evaluate the microbiota of necrotic pulp in teeth without carious lesions where the crown and root were intact and to test the sensitivity of this microbiota to antibiotics in order to improve treatment. The necrotic pulp was sampled from 26 single‐rooted teeth in intact pulp chambers. A total of 84 strains were isolated. The number of species isolated per tooth varied from 2 to 8, with a strong component (81%) of anaerobic bacteria. The most commonly represented species were Bacteroides gracilis, Propionibacterium acnes, Fusobacterium nucleatum, Prevotella buccae and Eubacterium lentum. The sensitivity of these organisms to amoxicillin, amoxicillin combined with clavulanate and tetracycline was evaluated by Etest on 38 isolates. For all strains tested, the minimum inhibitory concentration values obtained were low and substantially below effective serum concentrations for these antibiotics. These data enable us to devise suitable treatments for acute development of apical lesions and to prevent dissemination of this source of infection to the rest of the host.
Molecular analysis of representative Streptococcus gordonii Spp phase variants reveals no differences in the glucosyltransferase structural gene, gtfG
Authors: Vickerman M. M. , Jones G. W. , Clewell D. B.
Published: December 2007

Streptococcus gordonii glucosyltransferase polymerizes sucrose to form glucans, which confer a hard, sucrose‐promoted phenotype (Spp+) to colonies on sucrose agar plates. The glucosyltransferase structural gene, gtfG, is positively regulated by the upstream determinant, rgg. Strain Chain's undergoes a spontaneous, reversible phase variation between high (Spp+) and low (Spp−) levels of glucosyltransferase activity. Representative strains were examined to gain insights into the basis of glucosyltransferase phase variation. Western blots indicated that the level of glucosyltransferase activity was related to the amount of extracellular glucosyltransferase protein produced by Spp− and Spp+ strains. The nucleotide sequence of rgg and gtfG of the Spp+ strain CH97 was found to be identical to that of the Spp+ parent, indicating that DNA differences in these regions are not the basis for glucosyltransferase phase variation. Indeed, 13C‐NMR spectroscopy suggested that glucans synthesized by strain CH97 glucosyltransferase were similar to those synthesized by glucosyltransferase of the Spp+ parental strain, indicating a quantitative rather than qualitative change. However, one Spp− strain, CH1C1, had a point mutation in rgg; replacement of the parent rgg with the CH1C1 allele resulted in decreased levels of glucosyltransferase protein and activity. The results indicate that glucosyltransferase phase variation can occur in more than one way, and suggest that glucosyltransferase regulation may involve distally located regulatory gene(s) that affect rgg and/or gtfG expression.
Inhibition of purified enolases from oral bacteria by fluoride
Authors: Guha‐Chowdhury N. , Clark A. G. , Sissons C. H.
Published: December 2007

Enolase activity in strains of oral streptococci previously has been found to be inhibited by 50% (Ki) by fluoride concentrations ranging from 50 to 300 μM or more in the presence of 0.5 to 1.0 mM inorganic phosphate ions. In this study, enolase was extracted and partly purified by a two‐step process from five oral bacterial species and the effect of fluoride on the kinetics of enolase examined. The molecular weight of the putative enolase proteins was 46–48 kDa. The Vmax values ranged from 20 to 323 IU/mg and Km for glycerate‐2‐phosphate from 0.22 to 0.74 mM. Enolase activity was inhibited competitively by fluoride, with Ki values ranging from 16 to 54 μM in the presence of 5 mM inorganic phosphate ions. Ki values for phosphate ranged from 2 to 8 mM. The enolase from Streptococcus sanguis ATCC 10556 was more sensitive to fluoride (Ki=16±2) than was enolase from Streptococcus salivarius ATCC 10575 (Ki=19±2) or Streptococcus mutans NCTC 10449 (Ki=40±4) and all three streptococcal strains were more sensitive to fluoride than either Actinomyces naeslundii WVU 627 (Ki=46±6) or Lactobacillus rhamnosus ATCC 7469 (Ki=54±6) enolases. The levels of fluoride found to inhibit the streptococcal enolases in this study are much lower than previously reported and are likely to be present in plaque, especially during acidogenesis, and could exert an anti‐glycolytic effect.
Optimized oligonucleotides for the differentiation of Prevotella intermedia and Prevotella nigrescens
Authors: Conrads G. , Pelz K. , Hughes B. , Seyfarth I. , Devine D. A.
Published: December 2007

The gram‐negative, anaerobic bacterium Prevotella intermedia plays an important role in the progression of periodontitis, whereas the etiological role of the closely related but phenotypically indistinguishable species Prevotella nigrescens is controversial. To differentiate between these species properly, 16S rDNA/RNA directed, computer‐optimized oligonucleotides were designed and tested with 26 P. intermedia, 26 P. nigrescens and a number of closely and more distantly related strains. The oligonucleotides were used as primers in a polymerase chain reaction and could be demonstrated to be species specific with a detection limit of 50 bacterial cells, which could also be detected when diluted 1:15 with different plaque bacteria. In addition, the described oligonucleotides were digoxigenin‐labeled at the 3′ end and used as DNA probes in a dot blot hybridization assay. This assay, although slightly less sensitive than the polymerase chain reaction‐based method, gave species‐specific reactions and also allowed, (semi‐)quantification of bacterial cells in clinical specimens.
In vitro antifungal resistance of oral Candida albicans strains in non‐AIDS Patients
Authors: Monteil R. A. , Madinier I. , Fichoux Y. Le
Published: December 2007

Some cases of oral candidosis are refractory to antifungal treatment. This might be related to development of resistant Candida strains, but susceptibility testing is not standardized and not routinely available, and information related to this problem is scarce in non‐AIDS patients. In this study, the in vitro antifungal resistance of oral Candida albicans strains was evaluated. The strains were obtained from a cohort of 72 HIV‐negative patients with oral yeast carriage and clinical complaint. Laboratory identification revealed C. albicans in 93% of cases. None of these oral C. albicans isolates showed in vitro resistance to polyenes, but they showed varying resistance levels to fluorocytosine and azoles. This study confirms the usefulness of standardizing susceptibility testing so that it could be routinely available and of realizing a mycological diagnosis including an antifungigram when oral candidosis is suspected, whenever antifungal treatment with azoles is planned.
Active cytomegalovirus infection in human periodontitis
Authors: Contreras A. , Slots J.
Published: December 2007

This study used the reverse transcription polymerase chain reaction method to determine mRNA transcription of subgingival human cytomegalovirus (HCMV) in six adult and three localized juvenile periodontitis patients. The oligonucleotide primers targeted the major capsid protein gene to determine active HCMV infection. HCMV major capsid protein transcript was detected in deep periodontal pockets of two adult and two localized juvenile periodontitis patients but not in any shallow periodontal sites. The findings suggest that active HCMV replication can occur in periodontal sites. Further studies are necessary to establish whether periodontal reactivation of HCMV correlates with the initiation or progression of destructive periodontal disease.
Characterization of lymphocyte subpopulations in periapical lesions by flow cytometry
Authors: Sol M.‐A. , Tkaczuk J. , Voigt J.‐J. , Durand M. , Sixou M. , Maurette A. , Thomsen M.
Published: December 2007

The mechanisms by which the bacterial root‐canal infection leads to periapical bone destruction (cysts or granulomas) are not yet well understood. Previous works have shown elements of an active immune response in the lesions. In the present study, flow cytometry was used to improve the characterization of immune cells. Semiquantitative immunohistochemical analysis showed the presence of plasma cells, macrophages and B and T cells. The simultaneous use of several antibodies in flow cytometry allowed a more precise phenotype of the lymphocytes. The cysts displayed an abundance of B lymphocytes at the same time as a relative scarcity of CD8+ cells. CD4+ lymphocytes were the dominant lymphocyte population in most cases. A small number of γδ T lymphocytes and natural killer cells was found. These preliminary results show that flow cytometry may be used to characterize immune cells from inflamed tissue and opens the possibility for further functional studies.
Characterization of serum antibodies to Porphyromonas gingivalis in individuals with and without periodontitis
Authors: Pietrzak E. R. , Polak B. , Walsh L. J. , Savage N. W. , Seymour G. J.
Published: December 2007

Although Porphyromonas gingivalis is a denned pathogen in periodontal disease, many subjects control the infection without experiencing loss of attachment. Differences in host susceptibility to the disease may be reflected in the pattern of humoral antibodies against specific P. gingivalis antigens. The aim of this study was to determine the presence of antibodies against immunodominant P. gingivalis antigens as well as the isotype and subclass of anti‐P. gingivalis antibodies against outer membrane antigens in four groups of patients: P. gingivalis‐positive, 1) with and 2) without periodontitis, and P. gingivalis‐negative, 3) with and 4) without periodontitis. Antigens of molecular weight 92, 63, and 32 kDa and lipopolysaccharide were found to be immunodominant. Group 1 subjects showed a significantly higher response to the 92 and 63 kDa antigens compared with other groups. The response to lipopolysaccharide was significantly higher in group 1, and lower in group 4 than in groups 2, 3. Immunoglobulin Gi (IgGO, IgG2 and IgM antibodies against P. gingivalis outer membrane were present in all subjects, while only some subjects were seropositive for IgG3, IgG4 and IgA. There were no differences in concentrations for IgG1, IgG3 and IgM. The IgG2 concentration in group 4 was significantly higher than in groups 1 and 2, while the IgG4 concentration in group 4 was significantly lower than in other groups. The frequency of seropositivity for IgG4 and IgA was lowest in group 4, while IgG3 seropositivity was almost exclusively seen in healthy patients in groups 2, 4. These findings suggest that the presence of IgG3 may reflect non‐ susceptibility to the disease, while lack of IgG4 may be indicative of periodontal health and lack of infection.
Structural integrity of infant salivary immunoglobulin A (IgA) in IgA1 protease‐rich environments
Authors: Smith D. J. , King W. F. , Gilbert J. V. , Taubman M. A.
Published: December 2007

IgA1 protease‐secreting Streptococcus mitis often dominate the oral flora of the neonate and young infant at a time when salivary IgA concentrations are low and usually enriched in the secretory IgA1 subclass. To study the possible influence of these degradative enzymes on emerging host immunity, the presence of IgAl protease‐secreting streptococci was related to the structural integrity of salivary IgA in 24 infants who were between 3 and 18 weeks of age. At least one IgA1 protease‐secreting strain could be isolated from the oral mucosa of 79% of the infants and comprised a mean of 38% of the total streptococcal flora of these infants. Chromatographic analyses of resting whole saliva from 16 infants revealed, however, that 95% of the secretory IgA (range 88–100%) remained intact, indicating that minimal immediate IgA proteolysis occurred in the bulk salivary phase. Proteolysis of infant salivary IgA, presumably by indigenous IgA1 protease, could be observed after extended (more than 7 h) in situ incubation of whole saliva at 37°C. Salivary IgA antibody activities to 5. mitis components were demonstrated by Western blot in infants colonized with an IgA1 protease‐secreting flora. Preliminary evidence suggested that salivary antibody activity in some infants may be directed to IgA1 protease. Thus, the infant's antibody defenses not only appear very early in life but are substantively intact in the bulk salivary phase, even when the oral cavity is colonized with IgA1 protease‐secreting streptococcal flora.
Putative heat shock protein 70 gene from Actinobacillus actinomycetemcomitans: molecular cloning and sequence analysis of its gene
Authors: Minami J. , Matsumoto S. , Yamada T.
Published: December 2007

We have cloned and sequenced two overlapping fragments of chromosomal DNA from Actinobacillus actinomycetemcomitans. The nucleotide sequence contained two open reading frames. The deduced amino acid sequences of the two open reading frames showed significant homology with the heat shock proteins hsp70 and hsp40 of other organisms respectively. The upstream open reading frame consisted of 1902 bp, corresponding to 634‐amino‐acid residues. The CAA codon for glutamines was frequently seen in hsp70, i.e., in 30 of 32 glutamines (93.8%). The spacing region between the two open reading frames was unusually long compared with other prokaryotic organisms. A number of unique and distinguishing features of the sequences in the hsp70 family were verified, and it was found that a particular spacing sequence between the hsp70 and hsp40 gene loci can be used to identify A. actinomycetemcomitans from the periodontal pocket.
EVALUATION OF CMU/INTERTECT A‐FRAMES AS EMERGENCY SHELTER IN BANGLADESH, MARCH 1977
Authors: Ressler Everett M.
Published: December 2007

From February 13th‐19th 1977, a visit to Bangladesh was undertaken for the purpose of evaluating the emergency shelter units designed and built under the direction of the Carnegie Mellon University J INTERTECT Refugee Housing Team in 1975.
Management Of Disaster Victims And Rehabilitation Of Uprooted Communities
Authors: Klinteberg Robert af
Published: December 2007

The natural disasters which have so far dominated world attention are the least important in terms of number of victims. By far the most important problems, affecting tens of millions of people in non‐industrialized countries, are the creeping and recurrent disasters, generally made and/or aggravated by man. Subsequent deprivations frequently lead to the process of uprooting.

While a well organized and economically strong community can suffer severe set‐backs from a disaster it will not be permanently disrupted. On the other hand, an uprooted community is by definition seriously disrupted by upheaval or crushing of its social system, leading to disorganization, disheartedness and dependence.

This affects, to varying degrees, communities which have fled across ethnic or political borders and found themselves in a minority situation; as well as communities whose mode of life has been made obsolete or impossible by abrupt or slow ecological etc changes destroying their economy.

The phenomenon of uprooting poses particular problems demanding particular attention. It is especially important to stop and reverse the process. This calls for adequate preparedness, and for relief and rehabilitation without delays and frustrations which will aggravate the uprooting. The planning should normally aim for balanced integration, and always avoid over‐ and under‐aid. Also, in order to make the victimized communities self‐reliant, it is crucial to assist them in the reconstruction of their social systems.

Finally, the planning necessary for disaster preparedness coincides closely with what is needed for planning of development activities.
Education And Training Of Medical Students For Mass Casualties Situations
Authors: Adler Jacob
Published: December 2007

During the academic years I 9 75 and I 9 76 an interdisciplinary course in mass casualty management was given to sixth year medical students at the Hebrew University‐Hadassah Medical School in Jerusalem. The course included introductory lectures in definition of types of disasters, objectives in disaster intervention, description of local and national rescue organizations. Special importance was paid to mage of casualties and to a centralized system of evacuation from the disaster site. Further, hospital planning and deployment, stressing the role of the Emergency Room physician. The specific approach to multiple injuries including neurosurgical, orthopedic, abdominal, chest and soft tissue wounds was discussed in a panel meeting. Stress intervention and a comprehensive lecture on public health problems concluded this part of the course. The last half‐day was devoted to a practical exercise, simulating a town severely damaged by an earthquake. Although the course was an elective one, it was extremely well attended by the students, and its implementation was enthusiastically performed by both teachers and students.
A multi‐hospital system for disaster situations*
Authors: Eldar Reuben
Published: December 2007

From a review of the literature, it can be concluded that it is always advantageous and usually necessary to distribute the casualties of a disaster to several hosp‐hospitals rather than allowing 1 hospital, the nearest to the scene, to bear the whole load.

The potential of these hospitals would be enhanced if their preparedness and planning included anticipation of their functioning as part of a framework of the entire capacity of the medical services of an entire small country, or a region of a larger one. For the smooth functioning of this framework, central co‐ordination and control of the distribution of the load, the movements within it, the strengthening of its various component parts is necessary and services other than medical (transport, communications, etc.) are essential.

The establishment of a multihospital system for disaster situations for a whole region is suggested. This would integrate all medical facilities and services of the region, as well as promoting additional services, first horizontally integrated and later vertically, and would have a central governing body with full authority to prepare the system for the calamity and to execute the implementation of the plan when disaster occurs.

This body may find it useful to base some of its decision in the planning as well as the implementing stage, on an assumed population of casualties that is characteristic for the region and on implications that may be drawn from the population.
The value of hazard zone mapping: Water Authority ‘Section 24(5) surveys' in England and Wales
Authors: Parker Dennis
Published: December 2007

Successful problem‐solving is usually based upon a sound knowledge of the problem. Where the problem is a hazard, the impossibility of a ‘solution’ in terms of complete prevention is well known but proper problem assessment is still required. Detailed hazard zone mapping can be a valuable aid to planning to reduce hazards and to avoid disasters. A map is a powerful visual medium for conveying information where awareness of disaster proneness amongst public officials and others is limited. However, a map is also a comparatively limited medium for analysing risks and is most useful to planners if combined with detailed supporting documentation.

Maps and related documents are particularly useful if they provide a complete assessment of risk, are periodically updated, are integrated with the planning process and are systematically compiled and presented at an appropriate scale. Map scale often presents problems. The larger the scale, the less limited the map will be in recording useful detail but updating becomes more costly and therefore less likely. The Water Authorities Section 24(5) surveys are remarkably detailed and are valuable planning and research materials. They demonstrate the widespread nature of flooding problems and the need for decades of flood alleviation and drainage expenditure in England and Wales. Further standardisation of content and presentation could enhance the value of the survey reports but their value depends ultimately upon regular and systematic updating.
Earthquake hazard and vulnerability in the northeastern Mediterranean: the Corinth earthquake sequence of February‐March 1981
Authors: Ambraseys N.N. , Jackson J.A.
Published: December 2007

Population density, building type and earthquake magnitude are the main factors on which the total building damage following an earthquake depend. For the Greece ‐ Turkey region quantitative relations between these factors have been developed, which, in spite of the inaccuracies in the available data, allow crude estimates of the damage following a particular size earthquake to be made. This is demonstrated retrospectively for the Gulf of Corinth earthquakes in 1981.
The creation of vulnerability to natural disaster: Case studies from the Dominican Republic*
Authors: Jeffery Susan E.
Published: December 2007

This paper argues that natural disasters are not a category of events which can be separated from the broader Issues of development, since economic change can create vulnerability to natural disaster. The analysis of case studies from the Dominican Republic shows how the development of large scale commercialized agricultural production has created such vulnerability by reducing or restricting the resource base of certain sectors of the population. It b suggested that the vulnerable state of a population should be considered as much a cause of natural disaster as the extreme physical phenomena Involved. Therefore there Is a need both for a broader framework for analysis of disasters and for strategies to reduce such vulnerability to be an Integral part of long term development planning.
The long‐term impact of a man‐made disaster: An examination of a small town in the aftermath of the Three Mile Island Nuclear Reactor Accident
Authors: Goldsteen Raymond , Schorr John K.
Published: December 2007

This paper explores the long‐term effects of a nuclear accident on residents' perceptions of their physical and mental health, their trust of public officials, and their attitudes toward the future risks of nuclear power generation In their community. We find that in the period after the accident at Three Mile Island that there are constant or Increasing levels of distress reported by community residents. We conclude that the effects of a technological disaster may often be more enduring than those natural disaster and that greater research efforts should be made to Investigate the long‐term consequences of man‐made catastrophies of all types.
Lake Elsinore disaster: The slings and arrows of outrageous fortune
Authors: Sutphen Sandra
Published: December 2007

A case study of a flood which occurred at Lake Elsinore, California, February, 1980, focuses upon the assistance which the community received during both the flood and recovery periods. Relevant literature on disaster research is examined, including a model of disaster recovery, and the study places the events which occurred din Lake Elsinore within that recovery model. Implications for policy include the recommendation that decision‐makers consider the pre‐disaster growth of the community indecisions to support recovery assistance.
Pollution by halogenated aromatic compounds at Trissino: A case study of groundwater contamination and rehabilitation
Authors: Carli G. , Cosma E. , di Domenico A. , Macrì A. , Young C.P.
Published: December 2007

An investigation is presented on industrial contamination by benzotrifluoride percolation into ground water used for drinking water, in a populated area of 20 km2 at Trissino, north Italy, due to improper chemical waste disposal. Hydrogeological features of the situation are reported, as well as the emergency action taken, such as the surveys made and their analytical results. The epidemiology of the emergency is examined and rehabilitation measures are presented and discussed. Fortunately no major ecological or social disaster occurred, In part thanks to the speed and efficiency with which the affair was handled. It is notable that the authorities kept the public duly informed and thus retained their confidence.