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Biomedical subjects

W Sperr

Publications and source records attributed to W Sperr.

At least 37 records · Page 2Linked to original sources
PubMed1998

Endocarditis and aortal embolization caused by Aspergillus terreus in a patient with acute lymphoblastic leukemia in remission: diagnosis by peripheral-blood culture.

Disseminated infection with Aspergillus terreus is a rare disease that affects only the immunocompromised host. We report a case of systemic infection with A. terreus resulting in endocarditis, aortic embolization, and splenic infarction in a patient with acute lymphoblastic leukemia. Diagnosis through peripheral blood culture, lack of pulmonary involvement, and onset of disease during complete remission from leukemia constitute uncommon features of this case.

Aorta, Abdominal↗
PubMed1998

Procedures for enamel and dentin conditioning: a comparison of conventional and innovative methods.

Composite materials have become an integral part of the wide range of filling materials currently available. Conditioning is necessary to achieve adequate bonding of the composite material to enamel and dentin. Normally, this is done by applying acid preparations to the dental surfaces. These acids have an etching effect that causes surface roughening. The increasing application of lasers in dentistry has introduced another possibility. Laser irradiation can cause roughening of enamel and dentin surfaces. Another interesting alternative is the so-called kinetic cavity preparation technique. This method also results in distinct surface roughening. The purpose of the present study, was to compare the described methods. Tensile bond strength tests and shear bond tests were carried out to examine the adhesion of a composite material to surfaces treated with these methods. Laser irradiation with certain devices and the air-abrasive technique yielded results similar to those with acid etching.

Acid Etching, Dental↗
PubMed1997

Irradiation of infected root canals with a diode laser in vivo: results of microbiological examinations.

BACKGROUND AND OBJECTIVE: It was shown in previous studies [1] that the Nd:YAG laser can be used as an excellent tool for killing bacteria in root canals. The present examinations were carried out with a high power diode laser in comparison with a conventionally treated control group. STUDY DESIGN/MATERIALS AND METHODS: In this in vivo study, 40 patients with infected root canals underwent diode laser treatment. To verify the findings, microbiological tests were performed and the results compared to those obtained with conventional antibacterial treatment. RESULTS: The microbiological examination revealed streptococci at relevant concentrations in 20 cases and staphylococci in 5 cases. Extensive bacterial reduction was achieved in all cases by repeating laser treatment only once. Following the first irradiation, minimal streptococcal growth was observed in 7 root canals and minimal staphylococcal growth in 2 root canals. The maximum log kill was 4.22 for streptococci and 3.33 for staphylococci. In the control group, a maximum reduction by only one log step could be achieved in 6 of 10 patients. CONCLUSIONS: Compared with the results achieved with the conventional bactericidal technique in the control group, the high power diode laser seems to be highly suitable for killing bacteria in infected root canals.

Bacterial Infections↗
PubMed1997

Immunophenotypic and functional characterization of human tonsillar mast cells.

Mast cells (MC) are proinflammatory immune cells residing in various organs. Tissue-specific heterogeneity of MC has been described. The aim of this study was to establish the phenotype and functional profile of human tonsillar mast cells (ToMC) and to compare ToMC with lung-, skin-, and uterus MC. Tonsillar tissue was obtained from 23 patients suffering from hyperplastic tonsils and dispersed by enzymatic digestion. With the use of a combined toluidine blue/immunofluorescence staining technique, isolated ToMC were found to react with monoclonal antibodies (mAb) to immunoglobulin E, CD9, CD43, CD44, CD46, CD54, CD55, and CD59, as well as mAb to stem cell factor (SCF) receptor (CD117/c-kit). ToMC were not recognized by mAb to other cytokine receptors or mAb to CD3, CD11b, CD14, CDw17, the skin MC marker CD88 (C5aR) or CD89 (Fc alphaR). Activation of ToMC by recombinant human (rh) SCF or anti-IgE resulted in histamine secretion, whereas no effects were seen with rhC5a, rh granulocyte-macrophage colony-stimulating factor, or rh interleukin-1 through -10. In summary, ToMC exhibit functional and phenotypic properties similar to lung- or uterus MC. Unlike skin MC, ToMC lack C5aR and are unresponsive to rhC5a.

Antigens, Surface↗
PubMed1997

The carbon dioxide laser as an aid in apicoectomy: an in vitro study.

OBJECTIVE: To achieve the required goal of optimally sealing the apical section and the root-canal when performing an apicoectomy, the authors decided to use the CO2 laser as an additional aid. SUMMARY BACKGROUND DATA: The CO2 laser has previously shown to have an excellent sealing effect on dentin surfaces. METHODS: In this in vitro study, the authors examined the effects of CO2 laser application in apicoectomies with the help of color penetration tests and scanning electron microscopic (SEM) examinations. Sections and root canals were irradiated with low power (0.5 W) in continuous wave mode for totally 20 sec. The thermal stress for the adjacent tissues attaching thereto is moderate as shown by infrared-spectroscopy. RESULTS: A comparison with nonirradiated samples revealed that CO2 laser irradiation reduced color penetration at the section to a minimum. Also, irradiation of the root-canal wall resulted in satisfactory sealing of the surface. These findings were supported by the results of the SEM examinations. CONCLUSIONS: CO2 laser treatment optimally prepares the tooth for final intraoperative filling because of sealing of the dentinal tubules, the resultant elimination of niches for bacteria and the sterilizing effect of the laser.

Apicoectomy↗
PubMed1997

Bacterial reduction in periodontal pockets through irradiation with a diode laser: a pilot study.

This study examines the application of a diode laser with a wavelength of 805 nm for periodontal treatment. While the use of the diode laser in this field has not been investigated so far, several authors have reported on the use of neodymium:yttrium-aluminum-garnet (Nd:YAG) laser for such applications. The aim of this study was to examine the immediate effect of the diode laser in reducing the bacterial concentration in periodontal pockets. Important periodontal indices (PBI, CPITN) were assessed in 50 patients to obtain initial values for a planned long-term study and to select appropriate periodontal pockets for this study. The periodontal pockets were required to have a minimum depth of 4 mm. Only proximal pockets were included in this study. The patients were subdivided into two groups. After microbiological samples had been collected with sterile paper tips, the group selected for laser treatment was subjected to scaling. One week after scaling, the patients underwent laser treatment. One week later, a second series of microbiological samples were obtained and the patients were subjected again to scaling; this time, however, they did not undergo laser treatment after 1 week. Two weeks after scaling, another series of microbiological samples was collected. The microbiological samples were evaluated to verify bacterial elimination from the periodontal pockets. A comparison between the initial and the final bacterial counts revealed that irradiation with the diode laser facilitates considerable bacterial elimination, especially of Actinobacillus actinomycetemcomitans, from periodontal pockets.

Aggregatibacter actinomycetemcomitans↗
PubMed1997

Nd:YAG laser irradiation of infected root canals in combination with microbiological examinations.

In this in vivo study, 30 subjects with infected root canals were treated with the neodymium: yttrium-aluminum-garnet, or Nd:YAG, laser using standard laser settings and procedures. In microbiological examinations conducted before irradiation, the authors found streptococci in 30 cases and staphylococci in 15 cases. After the first irradiation, the authors found that 19 root canals showed minimal streptococcal growth and 10 root canals showed minimal staphylococcal growth.

Aluminum Silicates↗
PubMed1997

In vitro irradiation of infected root canals with a diode laser: results of microbiologic, infrared spectrometric, and stain penetration examinations.

This study aimed to examine the suitability of the diode laser with a wavelength of 810 nm for reducing bacteria in root canals. Forty-four extracted, endodontically prepared teeth were inoculated with Escherichia coli and Streptococcus faecalis. No bacterial growth was observed when the teeth were irradiated at an output power of 4 W and a pulse rate of 10 milliseconds, with breaks of 10 milliseconds between the irradiations. Exposure time was five times 5 seconds. Infrared spectroscopic examinations revealed that irradiation at 4 W under even circling movements resulted in a maximum rise in temperature of 6 degrees C on the root surface. Stain penetration tests and scanning electron microscopic examinations revealed complete closure of the dentinal tubules on the irradiated root canal walls.

Dental Pulp Cavity↗
PubMed1996

Alternatives in enamel conditioning: a comparison of conventional and innovative methods.

When composite restorative materials are used, conditioning of the enamel surface is necessary to achieve adequate retention of the composite material. Aside from conventional acid etching, laser treatment and pretreatment with kinetic cavity preparation technique are available. In our study, we compared the different methods using scanning electron microscopy and measurements of tensile strength. The results obtained using both laser treatments of Nd:YAG and Er:YAG lasers and kinetic cavity preparation were comparable to those obtained with the acid etching technique.

Acid Etching, Dental↗
PubMed1996

The advantage of CO2-treated dental necks, in comparison with a standard method: results of an in vivo study.

Various methods are used for treatment of hypersensitive dental necks. They all aim to seal exposed dentinal tubules, which are open toward the oral cavity and transmit stimuli to the sensitive nerve endings of the tooth pulp. The main sealing materials are fluoride preparations, strontium chloride, and hydroxyapatite. However, these materials must be applied periodically to achieve permanent freedom from pain. Since the introduction of laser technology into dentistry, efforts have been made to treat dentine hypersensitivity with the laser. An in vitro study revealed that CO2 laser irradiation results in almost complete closure of the dentinal tubules in the dental neck region. In the present in vivo study, the efficacy of laser treatment was examined in 72 patients with dentine hypersensitivity and 72 control patients over a period of 12 weeks. When success was defined as complete freedom from pain, the success rate in the laser group was 94.5%; when marked pain relief was included in the definition of treatment success, 98.6% of the patients were treated successfully. Treatment of the control group with conventional dental neck fluoridation resulted in no marked improvement. Laser Doppler measurements of pulpal blood flow immediately before and after treatment revealed no effects of laser irradiation on pulpal blood flow. Dentine samples were obtained from the dental necks 6 weeks after laser treatment and examined with atomic absorption spectroscopy (AAS). Tin was present in the samples, which suggests that the combined laser treatment and fluoridation result in permanent integration of fluoride in the dentine surface.

Adult↗
PubMed1995

Response of L-929 fibroblasts, human gingival fibroblasts, and human tissue mast cells to various metal cations.

Recent data suggest that under certain conditions, various metal cations are released from dental alloys. These ions may produce adverse effects in various cell types in vivo. In this study, the cytopathogenic effects of 13 metal cations on murine L-929 fibroblasts, human gingival fibroblasts, and human tissue mast cells were analyzed in vitro. Several metal cations (dose range, from 0.0033 to 1.0 mmol/L) were found to induce dose-dependent inhibition of 3H-thymidine incorporation into cultured fibroblasts. The rank order of potency (lowest observed effect level, LOEL) for L-929 fibroblasts was: Ag+ > Pt4+ > Co2+ > In3+ > Ga3+ > Au3+ > Cu2+ > Ni2+ > Zn2+ > Pd2+ > Mo5+ > Sn2+ > Cr2+. A similar rank order of potency was obtained for primary human gingival fibroblasts: Pt4+ > Ag+ > Au3+ > In3+ > Ga3+ > Ni2+ > Co2+ > Zn2+ > Cu2+ > Cr2+ > Pd2+ > Mo5+ > Sn2+. In primary human mast cells, Ag+ and Au3+ caused dose-dependent toxic histamine release, whereas the other metal cations were ineffective over the dose range tested. To investigate the mechanism of metal cation-induced effects, we performed DNA as well as electron microscopic analyses on cultured fibroblasts. Both the DNA pattern and the ultrastructure of L-929 cells and gingival fibroblasts after exposure to cytopathogenic metal cations revealed signs of necrosis but no signs of apoptosis. Together, our data provide evidence that various metal cations produce dose-dependent cytopathogenic effects in distinct cell types, including human gingival fibroblasts and human tissue mast cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

[Analysis of the fluoride content of drinking water in Austria 1993].

This study was undertaken to determine the concentration of fluoride ions in drinking water in Austria. The results show that the fluoride ion concentration is sufficient (0.7-1.0 ppm F-) to prevent caries only in very few parts of Lower Austria, Upper Austria, Salzburg, Tirol, Carinthia, and Styria. Hence, additional fluoridation is necessary to achieve successful prophylaxis of caries.

Austria↗
PubMed1993

Purification, characterization and N-terminal amino acid sequence of a new major allergen from European chestnut pollen--Cas s 1.

Pollens from trees of the order Fagales (e.g. birch, alder, hazel, and hornbeam) all contain one major allergen--the main cause for tree pollen allergy. So far the major allergens from birch (Bet v 1), alder (Aln g 1), hazel (Cor a 1), and hornbeam (Car b 1) have been characterized, showing high sequence similarity with each other (1-4). We present the molecular and immunologic characterization of Cas s 1, the major allergen from the European chestnut (Castanea sativa). From aqueous pollen extracts from European chestnut a protein was purified to homogeneity and was subjected to further investigation. The protein revealed a Mr of 22 kDa and was shown to represent the major allergen of the European chestnut (immunoblotting, histamine release) and designated Cas s 1. Despite a marked difference in Mr, Cas s 1 shows significant amino acid sequence similarity at the N-terminus and is antigenically closely related to the major birch pollen allergen Bet v 1 (17 kDa), as shown by binding to the anti-Bet v 1 monoclonal antibody BIP-1 and by IgE-inhibition tests using recombinant Bet v 1.

Allergens↗
PubMed1993

Lectin binding to chronic inflammatory gingival tissue: possible adhesion mechanisms based on lectin-carbohydrate interactions.

In this study, we analyzed the expression of different leukocyte surface antigens, of the adhesion molecules ELAM-1 and GMP-140 and binding of various lectins and neoglycoproteins in inflamed gingival tissue. Cell suspensions from collagenase-digested gingiva were analyzed by flow cytometry in a FACScan. The expression of ELAM-1, GMP-140, carbohydrate structures and lectins in gingival specimens was also studied by immunohistochemistry. Gingival tissue of patients with active periodontal disease contained between 5% and 50% CD45+ mononuclear cells, consisting mainly of CD19+ cells (B lymphocytes). CD62, resembling GMP-140, and ELAM-1 were strongly expressed on endothelial cells of these patients. Control subjects usually contained almost no CD45+ cells in their gingiva and no CD62+ or ELAM-1-positive endothelial cells could be found in 5 of 6 control persons. Analysis of the glycosylation pattern revealed staining of infiltrating cells by peanut agglutinin (PNA; specificity for galactose), whereas soy bean agglutinin (SBA; specificity for N-acetyl-galactosamine) bound to epithelial cells. An endogenous lactosyl-specific lectin could be detected on endothelial cells by binding of lactosyl-BSA. Ulex europeus I agglutinin (UEA-1, specific for fucose) showed selective staining of endothelial and epithelial cells. Expression of a fucose-binding lectin, demonstrated by binding of fucosylated BSA, could be found on infiltrating cells. The adhesion molecules ELAM-1 and GMP-140 seem to be involved in cell adhesion during chronic inflammation of the gingiva. Interaction of other carbohydrate residues with endogenous lectins might resemble additional adhesion mechanisms in inflamed gingiva.

Antigens, CD↗
PubMed1993

[Measuring drinking water fluoridation in Vorarlberg].

A pilot study was undertaken in Vorarlberg to determine the concentration of fluoride ions in drinking water. The results showed that 91.3% of the population was supplied by drinking water containing under 0.3 ppm fluoride and the remaining 8.7% by drinking water containing 0.3-0.6 ppm fluoride. Hence, the fluoride concentration was too low to prevent caries in all areas of Vorarlberg. Exogenous fluoridation of the drinking water or table salt in all districts of Vorarlberg is discussed. Measurements are planned for the whole of Austria, which may lead to a general recommendation for fluoridation of the water or salt nationwide.

Adolescent↗
PubMed1989

[Alternative filling methods for premolars and molars].

Extensive research and development work produced tooth-colored filling materials for premolars and molars which, although their indications are limited, provide for satisfactory treatment of cavities. But on account of their special properties these materials are unlikely to replace amalgam altogether. This would need products of a different nature. Currently available materials are at best complementary, but cannot be regarded as a true alternative.

Bicuspid↗