[Onychocola canadensis Sigler in onychomycosis : A new dermatophyte-like mould in Germany]. / Onychocola canadensis Sigler bei Onychomykose : Ein neuer Dermatophyten-ähnlicher Schimmelpilz in Deutschland.

Moulds or non-dermatophyte moulds (NDM) are being increasingly isolated as causative agent of onychomycoses. Known causes of a NDM-OM are Scopulariopsis brevicaulis, Fusarium, Aspergillus, Acremonium, Neoscytalidium dimidiatum, Arthrographis kalrae, and Chaetomium. In this article, 5 patients with suspected nail infection due to Onychocola canadensis are reported for the first time in Germany. Systemic antifungal agents are not considered to be effective in NDM onychomycosis. In individual cases, however, terbinafine seems to be effective in Onychocola canadensis infection of the nails. Treatment of choice represents, however, nontraumatic nail avulsion using 40 % urea ointment followed by antifungal nail lacquer with ciclopirox olamine or amorolfine.

Rapid identification of viridans streptococci by mass spectrometric discrimination.

Viridans streptococci (VS) are responsible for several systemic diseases, such as endocarditis, abscesses, and septicemia. Unfortunately, species identification by conventional methods seems to be more difficult than species identification of other groups of bacteria. The aim of the present study was to evaluate the use of cell matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF-MS) for the rapid identification of 10 different species of VS. A total of 99 VS clinical isolates, 10 reference strains, and 20 strains from our in-house culture collection were analyzed by MALDI-TOF-MS. To evaluate the mass-spectrometric discrimination results, all strains were identified in parallel by phenotypic and genotypic methods. MALDI-TOF-MS identified 71 isolates as the mitis group, 23 as the anginosus group, and 5 as Streptococcus salivarius. Comparison of the species identification results obtained by the MALDI-TOF-MS analyses and with the phenotypic/genotypic identification systems showed 100% consistency at the species level. Thus, MALDI-TOF-MS seems to be a rapid and reliable method for the identification of species of VS from clinical samples.

Transformation of rabbit lymphocytes by an Epstein-Barr virus-related herpesvirus from Macaca arctoides.

Herpesvirus Macaca arctoides (HVMA), an Epstein-Barr virus (EBV)-related herpesvirus of macaque origin, induces malignant lymphomas in rabbits. To get more insights into the oncogenesis of the EBV/HVMA infection the aim of the present study was to prove the in vitro transforming ability of HVMA for rabbit lymphocytes as well as human umbilical cord blood lymphocytes. As a result, B-cell transformation could be demonstrated after infection with HVMA in all mononuclear cell samples of 20 rabbits. The transformation was evaluated microscopically and confirmed by the expression of EBV-related nuclear antigens. The transforming activity led to the establishment of permanent rabbit lymphoblastoid cell lines cultured up to more than 90 passages. The cell lines contained EBV-like HVMA-DNA. Interestingly, the transformed rabbit lymphocytes showed chromosomal abnormalities with a subtetraploid karyotype. The low extent of lytic cycle-dependent expression of virus capsid antigen in the established cell lines increased after treatment with the inducing agents iododeoxyuridine and mitomycin C. In contrast, no transformation could be induced after exposure of human umbilical cord blood lymphocytes to HVMA. The permanent rabbit lymphoblastoid cell lines provide a model for further studies on the role of EBV/HVMA in oncogenesis of lymphomas. In addition, it might be suitable for testing potential antiviral compounds in vitro.

Cytogenetic detection of a trans-species bystander effect: induction of sister chromatid exchanges in murine 3T3 cells by ganciclovir metabolized in HSV thymidine kinase gene-transfected Chinese hamster ovary cells.

Due to the very limited transduction capacity of hitherto available vectors, the success of gene therapy of tumours by means of suicide genes has so far essentially depended on the transfer of toxic drug metabolites from transduced (metabolizing) cells to adjacent non-transduced cells via gap junctions (bystander effect). Most experimental systems for the detection of a bystander effect yield net data of cell losses and cannot differentiate between killed transduced versus killed bystander cells. Here we report on metabolic cooperation in vitro between CHO cells stably transfected with the thymidine kinase gene of herpes simplex virus type-1 (HSVtk) (metabolizing cells) and Swiss albino 3T3 cells (bystander cells). Both cell lines are readily distinguishable by single cell and colony morphology and by their chromosomal constitution. While 3T3 cells cultured alone were refractory to the antiviral drug ganciclovir (GCV), co-culture with CHO-HSVtk(+) cells led to a dramatic reduction in plating efficiency as well as to a 4-fold increase in sister chromatid exchange rates induced by very low GCV concentrations in the 3T3 bystander cells. The modulator of gap junctional cooperation, all-trans retinoic acid, caused a strong augmentation of the bystander effect, while 18alpha-glycyrrhetinic acid, an inhibitor of gap junctional communication, drastically diminished the toxicity of GCV in the bystander cells. Whereas CHO-HSVtk(+) cells showed a distinct immunoreactivity for connexin43 in the cell membranes, 3T3 cells were almost negative. The co-culture system described here allows unequivocal distinction between metabolizing and bystander cells. In this way, mechanistic aspects of the transfer of genotoxic/cytotoxic metabolites to cells, which per se are unable to form them, become accessible to investigation.

Comparative in vivo and in vitro investigation of interfacial bond variability.

This comparative in vivo/in vitro study investigated the interfacial adaptation between dentin and composite resins in totally bonded adhesive restorations placed under clinical and laboratory conditions in the same tooth. Cavities were prepared in buccal or lingual surfaces of 47 third-molar teeth scheduled for extraction and randomly assigned for treatment with the following bonding systems/restorative materials: Clearfil Liner Bond 2/Clearfil AP-X (Group I, n = 10), Resulcin AquaPrime + Monobond/MFR Merz (Group II, n = 9), Prime&Bond 2.1/Dyract AP (Group III, n = 9), Scotchbond Multi-Purpose/Z-100 (Group IV, n = 10), and Ecusit Primer AB-Mono/Ecusit (Group V, n = 9). In Group V, a thin layer of a low-viscous compomer (Primaflow) was interposed between the dentin and the composite resin during restoration placement (according to the manufacturer's directions). After extraction a second filling was placed in each tooth with identical materials in the same manner as in vivo. The restoration-dentin interface was evaluated in longitudinally cut sections of the specimens by SEM-analysis, and the frequency of gap formation between restoration and dentin was calculated. Median percentages for the in vivo/in vitro frequency of interfacial gap formation were 29.2%/13.9% in Group I, 33.3%/20.0% in Group II, 40%/5.3% in Group III, 53.9%/30.4% in Group IV and 13.8%/0% in Group V. Comparison of gap formation frequency between fillings placed in vivo and in vitro revealed significant differences (p < 0.05) in Groups II, III and IV. However, in Groups I and V the internal adaptation was not significantly different between in vivo and in vitro applied restorations. A significant (p < 0.01) correlation (Spearman-Rho rank correlation coefficient) was found for the corresponding in vivo and in vitro fillings placed in the individual teeth with regard to interfacial gap formation. It was concluded that achievement of a completely gap-free internal adaptation between restorative material and dentin in totally bonded composite resin restorations is difficult to predict under in vivo as well as in vitro conditions.