Biomedical subjects

C Wyss

Publications and source records attributed to C Wyss.

At least 19 recordsLinked to original sources

PubMed2004

Treponema putidum sp. nov., a medium-sized proteolytic spirochaete isolated from lesions of human periodontitis and acute necrotizing ulcerative gingivitis.

So far, little phenotypic heterogeneity has been detected in cultured oral treponemes with trypsin-like proteolytic activity, and all have been assigned to the species Treponema denticola. However, comparisons of protein patterns and antigen expression in our collection of proteolytic oral treponemes occasionally identified isolates with a unique phenotype; e.g. strain OMZ 830 (=ATCC 700768), which qualified as a 'pathogen-related oral spirochaete' due to the presence of a approximately 37 kDa protein reactive with the Treponema pallidum FlaA-specific mAb H9-2. In addition to such single isolates, a homogeneous group of seven independent strains is described that were highly motile, medium-sized, proteolytic but asaccharolytic spirochaetes and were cultured from human gingivitis, periodontitis and acute necrotizing ulcerative gingivitis in medium OMIZ-Pat supplemented with 1% human serum and antibiotics. Growth of these spirochaetes in OMIZ-Pat was not dependent on, but was stimulated by, human or bovine serum. Carbohydrates were neither required nor stimulatory for growth. The protein and antigen patterns of total cell extracts of these organisms separated by SDS-PAGE were distinct from those of all previously cultured spirochaetes, with highest similarity to T. denticola. The novel spirochaete has a 2 : 4 : 2 arrangement of the periplasmic flagella, similar to T. denticola. However, the flagellin pattern as detected by immunostaining or glycan staining of Western blots readily distinguished the novel group from T. denticola. Also, distinct from reference strains of T. denticola, none of the novel isolates displayed sialidase or dentilisin activities, both of which are expressed by most strains of T. denticola. Trypsin-like activity and other enzymes as detected by API ZYM test were similar to those of T. denticola. The status of a novel species is supported by the 16S rRNA gene sequence, with 98.5% similarity to its closest cultured relative, T. denticola. The name Treponema putidum sp. nov. is proposed (type strain OMZ 758T=ATCC 700334T=CIP 108088T).

Antigens, Bacterial↗

PubMed2001

Selenium-dependent growth of Treponema denticola: evidence for a clostridial-type glycine reductase.

Assessment of the nutritional requirements of Treponema denticola disclosed a strict growth dependence on selenium. In vivo labeling of cells of this organism with (75)Se and electrophoretic analysis revealed three labeled bands, two of which were selenoproteins correlating in size with subunits A and B of glycine reductase. Antibodies directed against glycine- or betaine-reductase subunits of Eubacterium acidaminophilum specifically also reacted with proteins from cell lysates of T. denticola. Moreover, ORFs within the T. denticola genome sequence were found whose products display high sequence similarity to glycine-reductase subunits. These findings strongly support the notion that T. denticola ferments amino acids via the activity of glycine reductase, an enzyme previously thought to be restricted to gram-positive bacteria.

Amino Acid Oxidoreductases↗

PubMed2001

Tetrahydrobiopterin increases myocardial blood flow in healthy volunteers: a double-blind, placebo-controlled study.

OBJECTIVES: Tetrahydrobiopterin (BH4) is a regulatory cofactor for the activity of nitric oxide synthases. Vasodilating properties of BH4 have been reported in vitro and in vivo. The influence of BH4 on myocardial blood flow (MBF), however, is largely unknown. We therefore performed a double-blind, placebo-controlled study to investigate the effect of intravenous BH4 on MBF in healthy volunteers. METHODS AND RESULTS: Resting MBF was assessed in 15 subjects receiving either intravenous BH4 (10 mg/kg) or placebo using positron emission tomography (PET) and [13N]ammonia. From a mean baseline MBF of 0.91 +/- 0.09 ml/min/g, MBF increased to 1.18 +/- 0.10 ml/min/g after BH4 (n = 10; p = 0.0042). In contrast, in the group receiving placebo mean MBF remained unchanged (non-significant decrease from 0.97 +/- 0.19 to 0.84 +/- 0.11 ml/min/g; n = 5; p = 0.36). Systemic haemodynamics and ECGs remained unaffected in both groups. BH4 was very well tolerated. CONCLUSION: Systemically administered BH4 is safe and effectively increases resting MBF in healthy volunteers.

Adult↗

PubMed2001

Treponema parvum sp. nov., a small, glucoronic or galacturonic acid-dependent oral spirochaete from lesions of human periodontitis and acute necrotizing ulcerative gingivitis.

Small oral spirochaetes with a strict dependence on either glucuronic acid (GluA) or galacturonic acid (GalA) were isolated from European patients with periodontitis and from Chinese patients with either gingivitis or acute necrotizing ulcerative gingivitis (ANUG). Thirteen such isolates were similar phenotypically to Treponema pectinovorum ATCC 33768T and this classification was confirmed by 16S rRNA sequencing. However, four isolates differed from T. pectinovorum by their small cell size, by a prominent beta-glucuronidase activity, by a distinct protein and antigen profile, by an inability to grow on pectin as sole source of carbohydrate and by a markedly enhanced growth rate when supplied with a second carbohydrate (L-arabinose, D-galactose, D-glucose, D-fructose, D-mannitol, D-mannose, pectin, D-ribose or D-xylose) in addition to the essential GluA/GalA. By 16S rRNA sequencing these four isolates clustered in the recently described phylotype 'Smibert-2'. T. pectinovorum (14 strains) and 'Smibert-2' (four isolates with beta-glucuronidase activity) could each be subdivided into two serotypes based on immunoblot reactivity with two mAbs. Representatives of the two groups, including T. pectinovorum ATCC 33768T, showed a 1:2:1-type periplasmic flagellar arrangement. 'Smibert-2' is described as a novel species, Treponema parvum sp. nov., with isolate OMZ 833T (= ATCC 700770T) proposed as the type strain and OMZ 842 (= ATCC 700773) as reference strain for a second serotype.

Acute Disease↗

PubMed1999

Treponema lecithinolyticum sp. nov., a small saccharolytic spirochaete with phospholipase A and C activities associated with periodontal diseases.

Strong phospholipase A (PLA) and phospholipase C (PLC) activities as potential virulence factors are the outstanding characteristics of eight strains of small oral spirochaetes isolated from deep periodontal lesions. By qualitative dot-blot DNA-DNA hybridization and 16S rDNA sequence comparison, these spirochaetes form a distinct phylogenetic group, with Treponema maltophilum as its closest cultivable relative. Growth of these treponemes, cells of which contain two endoflagella, one at each pole, was autoinhibited by the PLA-mediated production of lysolecithin unless medium OMIZ-Pat was prepared without lecithin. N-Acetylglucosamine was essential and D-ribose was stimulatory for growth. All isolates were growth-inhibited when 1% foetal calf serum was added to the medium. Growth on agar plates supplemented with human erythrocytes produced haemolysis. In addition to PLA and PLC, the new isolates displayed strong activities of alkaline and acid phosphatases, beta-galactosidase, beta-glucuronidase, N-acetyl-beta-glucosaminidase and sialidase, intermediate activities of C4- and C8-esterases, naphthol phosphohydrolase and alpha-fucosidase and a distinctive 30 kDa antigen detectable on Western blots. This phenotypically and genotypically homogeneous group is proposed as a novel species, Treponema lecithinolyticum sp. nov., with isolate OMZ 684T designated as the type strain. A molecular epidemiological analysis using a T. lecithinolyticum-specific probe showed this organism to be associated with affected sites when compared with unaffected sites of periodontitis patients. This association was more pronounced in patients with rapidly progressive periodontitis than in those with adult periodontitis.

Adult↗

PubMed1998

Flagellins, but not endoflagellar sheath proteins, of Treponema pallidum and of pathogen-related oral spirochetes are glycosylated.

Glycosylation of the flagellar core proteins (FlaBs) was detected in Treponema pallidum Nichols and in the type or reference strains of seven oral Treponema species. In several nonmotile strains of oral treponemes, the FlaBs were undetectable by both antibody and glycan staining. In contrast, a spontaneous low-motility variant of T. vincenti poundi-related strain RitzA, OMZ 305A, lacked the flagellar sheath protein (FlaA) and the two glycan-staining FlaB bands of the wild type, but antibody labeling revealed a novel FlaB band with a lower relative molecular weight. A ca. 38-kDa component of isolated endoflagella of T. vincentii OMZ 800 was identified on Western blots as FlaA by monoclonal antibody (MAb) H9-2, which specifically labels the 37-kDa FlaA protein of T. pallidum. Glycan and H9-2 labeling patterns similar to those of T. pallidum were observed in whole-cell extracts of T. medium G7201 and of 10 strains classified as T. vincentii and as two T. vincentii-related taxons. These four groups were thus identified as cultivable pathogen (T. pallidum)-related oral spirochetes as defined by labeling with MAb H9-2. No H9-2 MAb-reactive component could be detected in T. amylovorum, T. denticola, T. maltophilum, T. pectinovorum, and the three subspecies of T. socranskii.

Flagellin↗

PubMed1997

Treponema amylovorum sp. nov., a saccharolytic spirochete of medium size isolated from an advanced human periodontal lesion.

A highly motile, medium-size, saccharolytic spirochete was isolated from an advanced human periodontal lesion in medium OMIZ-Pat supplemented with 1% human serum. The growth of this organism is dependent on either glucose, maltose, starch, or glycogen. The cells contain six endoflagella, three per pole, which overlap in the central region of the cell body. On the basis of its cell morphology and enzyme activities, as well as its sodium dodecyl sulfate-polyacrylamide gel electrophoresis protein and antigen profiles, this organism is clearly distinct from all previously cultured spirochetes. The presence of a novel species is supported by the 16S rRNA sequence of this organism, which places it in phylotype 19 of Choi et al. (B. K. Choi, B. J. Paster, F. E. Dewhirst, and U. B. Göbel, Infect. Immun. 62:1889-1895, 1994). The only isolate, strain HA2P, is designated the type strain of a novel species, for which we propose the name Treponema amylovorum.

Bacterial Proteins↗

PubMed1996

Treponema maltophilum sp. nov., a small oral spirochete isolated from human periodontal lesions.

A novel culture medium for cultivation of fastidious oral anaerobes is described. This medium, OMIZ-Pat, consists of a rich chemically defined basal medium supplemented with asialofetuin, as well as yeast extract and Neopeptone fractions. Addition of 1 mg of rifampin per liter and 100 mg of fosfomycin per liter allowed routine isolation of spirochetes by a limit dilution method in 96-well plates containing liquid OMIZ-Pat. In addition to members of the four previously recognized species of oral treponemes (Treponema denticola, Treponema pectinovorum, Treponema socranskii, and Treponema vincentii), 26 previously undescribed spirochete strains belonging to one group were isolated. We propose the name Treponema maltophilum sp. nov. for these small spirochetes, which have two endoflagella; one endoflagellum is attached at each cell pole, and the endoflagella overlap in the middle of the cell. Growth of these organisms was dependent on a carbohydrate like D-arabinose, L-fucose, D-maltose, L-rhamnose, D-ribose, D-sucrose, or D-trehalose and was inhibited by fetal bovine serum. T. Maltophilum is distinguished from other oral Treponema species by its 16S rRNA sequence, its protein and antigen patterns as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting, and its characteristic alpha-glucosidase activity. The strains included in the new species on the basis of their 16S rRNA sequences are heterogeneous with respect to their alpha-fucosidase, and beta-glucuronidase activities, their dependence on N-acetylglucosamine, and their antigens as detected with patient antibodies. Strain BR is designated the type strain, and strains HO2A and PNA1 are reference strains of the new species.

Antibodies, Bacterial↗

PubMed1996

Phylogenetic analysis of pathogen-related oral spirochetes.

Recently, Riviere et al. reported as yet uncultivable invasive oral spirochetes that cross-reacted with monoclonal antibodies (MAbs) specific for Treponema pallidum (G. R. Riviere, K. S. Elliot, D. F. Adams, L. G. Simonson, L. B. Forgas, A. M. Nilius, and S. A. Lukehart, J. Periodontol. 63:131-136, 1992; G. R. Riviere, M. A. Wagoner, S. A. Baker-Zander, K. S. Weisz, D. F. Adams, L. Simonson, and S. A. Lukehart, N. Engl. J. Med. 325:539-543, 1991; G. R. Riviere, K. S. Weisz, D. F. Adams, and D. D. Thomas, Infect. Immun. 59:3377-3380, 1991; G. R. Riviere, K. S. Weisz, L. G. Simonson, and S. A. Lukehart, Infect. Immun. 59:2653-2657, 1991). In an attempt to phylogenetically analyze these pathogen-related oral spirochetes, we used immunomagnetic separation, combined with comparative sequence analysis of 16S rRNA genes amplified in vitro by the PCR. The bacteria were immunomagnetically enriched from subgingival plaque samples of patients with rapidly progressive periodontitis by using MAb H9-2 specific for the 37-kDa endoflagellum sheath protein of T. pallidum. After PCR amplification with universal eubacterial primers 16S rRNA gene fragments were cloned into Escherichia coli. A total of 20 randomly selected recombinants were analyzed by sequencing about 200 to 300 bases of the 500-bp inserts. All the spirochetal 16S rRNA sequences clustered to previously described, as yet uncultivable cluster 7 treponemes of group I (B. K. Choi, B. J. Paster, F. E. Dewhirst, and U. B. Göbel, Infect. Immun. 62:1889-1895, 1994). With a sequence similarity of 96.4% the most closely related cultivable treponeme was Treponema vincentii, which also belongs to the group I treponemes. Subsequent immunological analysis of cultured treponemes with MAb H9-2 revealed that only T. vincentii strains showed specific immunofluorescence or a characteristic 37-kDa band in immunoblots. We therefore conclude that pathogen-related oral spirochetes constitute a heterogeneous population of treponemes comprising T. vincentii and T. vincentii-related organisms that have common epitopes cross-reacting with MAb H9-2.

Antibodies, Bacterial↗

PubMed1996

Investigations on a Swiss area highly endemic for Echinococcus multilocularis.

Anecdotal information suggested that a focus of hyperendemicity may be present in a small area of the Canton of Fribourg in Switzerland. Therefore, the prevalence of E. multilocularis was assessed both in the fox and the rodent population over a two-season-period. A high prevalence ranging between 47% and 56% was consistently determined in the fox population. An Arvicola terrestris population was infected at 39% in the first season of investigation and at 11% in the following season. A subsequent seroepidemiological survey in the population of inhabitants surrounding the area provided no indication of seroconversion and thus no indication of infection for humans. However, a longer-term survey will be needed to assess more precisely the risk of disease occurrence among these inhabitants.

Animals↗

PubMed1995

Long-term Results on Quality of Life of Surgical Treatment of Obesity with Vertical Banded Gastroplasty.

BACKGROUND: Few papers assess quality of life after vertical banded gastroplasty (VBG). METHODS: 100 patients with severe obesity (preoperatively mean BMI 41.7 kg m(2)) answered an interview 60 (+/- 2.5) months after VBG. RESULTS: There was no fatal outcome. Nine patients had pulmonary embolus; ten patients required reoperation because of stomal stenosis. Of the 89 patients that still bore a gastroplasty at the moment of the interview, 65 had lost more than 40% of their excess weight (= "success'). Improvement in quality of life of these 89 patients was reflected by significant diminution of depression and back pains. Significant diminution of arterial hypertension and improvement of professional satisfaction, and of social, physical, and sexual activity was significantly related to weight loss. CONCLUSION: VBG resulted generally in a favorable long-term effect on quality of life. However, patients should be informed preoperatively about potential side-effects such as possible persistent vomiting after several years, esophagitis and gastritis, restriction in the choice of foods and prolongation of meals.

Journal Article↗

PubMed1993

Aspartame as a source of essential phenylalanine for the growth of oral anaerobes.

Phenylalanine and aspartic acid requirements were determined for 13 species of oral bacteria using the chemically defined medium OMIZ-W1. None of Actinobacillus actinomycetemcomitans, Bacteroides forsythus, Eikenella corrodens, Selenomonas sputigena, Treponema pectinovorum, T. socranskii, or Wolinella recta required either of these amino acid constituents of aspartame (L-aspartyl-L-phenylalanine methylester). Phenylalanine was essential for the growth of Capnocytophaga gingivalis, Eubacterium timidum, Fusobacterium nucleatum, Porphyromonas gingivalis, T. denticola, and T. vincentii, while aspartic acid was not required. With the exception of E. timidum, all phenylalanine-dependent strains could grow when the free amino acid was replaced by aspartame at concentrations at least 10-fold lower than those used for aspartame as an artificial sweetener.

Aspartame↗

PubMed1993

Support of peptide-dependent growth of Bacteroides forsythus by synthetic fragments of haemoglobin or fetuin.

The putative periodontal pathogen Bacteroides forsythus is a fastidious Gram-negative anaerobe with high proteolytic activity. For growth in a chemically defined medium containing insulin it required serum. Serum could be replaced by human haemoglobin or bovine asialofetuin, or by proteolytic fragments of these two proteins. Four such fragments consisting of from 8 to 18 amino acid residues were isolated and sequenced. Only aspartic acid, threonine, and valine were common to all peptides. An undecapeptide, Hba11, and a dodecapeptide, AsF12, were synthesized and found to be active at micromolar concentrations, but only when presented in combination with insulin. An analysis of amino acid requirements excluded a direct essential role of peptides as sources of amino acids in complete medium, except for valine. Should Bact. forsythus have an essential requirement for this amino acid, it could be satisfied by micromolar concentrations of peptide but not millimolar concentrations of the free amino acid in the absence of peptide. Bact. forsythus could salvage the essential amino acids lysine and isoleucine at 100-fold lower concentrations when presented in peptide-bound form compared to the free amino acids, and at 10-fold lower concentrations of peptide compared to Porphyromonas gingivalis W83, which in contrast to Bact. forsythus grew on free amino acids in the absence of insulin and peptides.

Amino Acid Sequence↗

PubMed1992

Growth of Porphyromonas gingivalis, Treponema denticola, T. pectinovorum, T. socranskii, and T. vincentii in a chemically defined medium.

A chemically defined medium, OMIZ (Oral Microbiology and Immunology, Zürich)-W1 was developed. Medium OMIZ-W1 supports the long-term proliferation of a wide range of oral anaerobes, including representative strains of four Treponema species and Porphyromonas gingivalis. High concentrations of ascorbic acid and ammonium ions proved to be important for the growth of these organisms. T. denticola CD-1 grew in the absence of polyamines and long-chain fatty acids, T. pectinovorum and T. socranskii required polyamines, whereas T. vincentii depended on both polyamines and lecithin for growth. Specific requirements for purines and/or pyrimidines were detected, and these requirements could be used to distinguish Haemophilus-Actinobacillus group organisms. Some strains of P. gingivalis grew without vitamin K, while others were not satisfied by menadione but required its precursor 1,4-dihydroxy-2-naphthoic acid. Protoporphyrin IX or hemin equally satisfied the porphyrin requirements of P. gingivalis and Bacteroides forsythus, whereas ferrous sulfate was more efficiently used as a source of iron than was hemin. The cellular cohesiveness of P. gingivalis increased with high concentrations of hemin in the growth medium. Prevotella intermedia, B. forsythus, and several strains of P. gingivalis were more fastidious and required a protein or serum supplement to grow in medium OMIZ-W1.

Ascorbic Acid↗

PubMed1991

The causes of subsequent arthrodesis of the ankle joint.

Between 1917 and 1984, we performed 217 arthrodesis of the ankle joint. Posttraumatic states were the cause of the osteoarthritis in 153 cases, whereas 118 of these cases were malleolar fractures. The accident X-rays were analyzed, and the fractures were classified in accordance with the classification of Weber (11). Our own system was used for the radiological classification of the degree of arthritis. The extent of malunion after the initial care was assessed. We found type-C malleolar fractures most frequently, the most striking malunion being the shortening of the fibula. In all fractures requiring subsequent arthrodesis, osteoarthritis of degree III-IV was present. In most cases the malleolar fractures treated surgically showed a shortening of the fibula and must be considered failures of initial care. The classification into types according to Weber also seems to provide prognostic information about the subsequent need for arthrodesis. Here it can be observed that C-fractures and compression fractures more often require arthrodeses.

Ankle Injuries↗

PubMed1989

Selected low-cohesion variants of Actinobacillus actinomycetemcomitans and Haemophilus aphrophilus lack distinct antigens recognized by human antibodies.

Actinobacillus actinomycetemcomitans OMZ 346 A and Haemophilus aphrophilus OMZ 384 A, isolated on a synthetic selective and differentiating agar, show the highly cohesive and wall adherent growth in liquid medium which is typical for all primary oral isolates of these species. From each of them a low cohesion variant, OMZ 346 F and OMZ 384 F, respectively, was obtained by selection for cells growing in suspension. Screening of Western blots of these four strains with several human sera revealed the loss of a 4000 Mr antigen in both F strains. Human antibodies bound to the 4000 Mr band material on preparative Western blots of the A strains were eluted with 4 M magnesium chloride. These antibodies showed no cross-reaction between the 4000 Mr material of the two closely related species.

Actinobacillus↗

PubMed1989

Campylobacter-Wolinella group organisms are the only oral bacteria that form arylsulfatase-active colonies on a synthetic indicator medium.

Most oral bacteria tested formed colonies on a chemically defined medium with a chromogenic arylsulfatase substrate. Arylsulfatase activity was, however, restricted to Campylobacter-Wolinella group organisms, including Wolinella recta, a possible periodontopathogen. W. recta was the only arylsulfatase-active species against which consistently high levels of antibody were detected in human sera.

Arylsulfatases↗

PubMed1989

Dependence of proliferation of Bacteroides forsythus on exogenous N-acetylmuramic acid.

Bacteroides forsythus is the first wild-type or mutant bacterium found to require exogenous N-acetylmuramic acid for proliferation and maintenance of cell shape. This implies so far unknown pathways for peptidoglycan synthesis and a strict dependence of B. forsythus on other bacteria in its oral habitat. Addition of N-acetylmuramic acid to conventional bacteriological media allows routine cultivation of this fastidious organism.

Bacteroides↗