An innovative method for in-situ composition analysis of fixed metallic dental restorations.

Dental restorations made from alloys corrode during their service time. In cases of suspected toxic or allergic reactions to the corrosion products, the composition of the intraoral dental restorations has to be determined. The sample materials can be obtained intra-orally in a non-destructive manner using the chipping test. Metallic shavings are extracted with the aid of a dental stone and graphite carrier platelet, which is then transferred to an electron microscope for electro dispersive X-ray (EDX) analysis. The chipping test suffers from a rather complicated and error-prone procedure of obtaining and transferring the samples. OBJECTIVE: The objective of the present study was the validation of a simplified method for non-destructive in-situ extraction of dental alloy samples, using a newly developed dental bur made from carbon fiber reinforced polyether ether ketone (PEEK), which at the same time serves as an electrically conductive sample carrier for EDX analysis. METHODS: Fifteen burs for dental hand pieces were manufactured from carbon fiber reinforced PEEK, using two formulations. The burs were passed over precious and non-precious dental alloys with different rotation speeds. The alloy samples embedded in the burs were analyzed using EDX and compared to a control. RESULTS: The burs manufactured from PEEK containing 30% short carbon fibers proved sufficiently robust for sample extraction even from the harder non-precious metals. The results of EDX analysis were in accordance with the control,no statistical significant differences, free of contamination, and were not affected by rotation speed,higher as 20%. SIGNIFICANCE: The proposed method is valid, practical and constitutes an improvement over the traditional chipping test.

[Reorientation of Medical Procedures Covered by Statutory Accident Insurance]. / Neuausrichtung der Heilverfahren der Gesetzlichen Unfallversicherung.

As of 01/01/2014, the German Statutory Accident Insurance (DGUV) has reorganized inpatient medical procedures. The central element of reorientation is the reorganization of the catalogue of types of accidents and type of medical procedures of hospitalized injured patients in 3 care stages. In addition, the reorientation also concentrates on hospitals with the highest performance and the best qualification and also focuses on severe and most severe injuries.This reorientation is also based on the White Paper of the German Society for Trauma Surgery (DGU), especially on the Trauma Network DGU. The new regulations will be implemented by the state associations of the German Statutory Accident Insurance.The hierarchy of care depends on established admission criteria and the severity of injury. This structuring also refers to special competence in the field of rehabilitation and will lead to the strengthening of multidisciplinary rehabilitation management and workplace-related modules of the healthcare. Overall, the accident insurance institution will place increased demands on their network partners.

Finite element analysis of the biomechanical effects of PEEK dental implants on the peri-implant bone.

Dental implants are mostly fabricated of titanium. Potential problems associated with these implants are discussed in the literature, for example, overloading of the jawbone during mastication due to the significant difference in the elastic moduli of titanium (110 GPa) and bone (≈1-30 GPa). Therefore poly-ether-ether-ketone (PEEK) could represent an alternative biomaterial (elastic modulus 3-4 GPa). Endolign(®) represents an implantable carbon fiber reinforced (CFR)-PEEK including parallel oriented endless carbon fibers. According to the manufacturer it has an elastic modulus of 150 GPa. PEEK compounds filled with powders show an elastic modulus around 4 GPa. The aim of the present finite element analysis was to point out the differences in the biomechanical behavior of a dental implant of Endolign(®) and a commercial powder-filled PEEK. Titanium served as control. These three materials were used for a platform-switched dental implant-abutment assembly, whereas Type 1 completely consisted of titanium, Type 2 of a powder-filled PEEK and Type 3 of Endolign(®). A force of 100 N was applied vertically and of 30° to the implant axis. All types showed a minimum safety factor regarding the yield strength of cortical bone. However, within the limits of this study the Type 2 implant showed higher stresses within the adjacent cortical bone than Type 1 and Type 3. These implant assemblies showed similar stress distributions. Endless carbon fibers give PEEK a high stability. Further investigations are necessary to evaluate whether there is a distinct amount of endless carbon fibers causing an optimal stress distribution behavior of CFR-PEEK.

Antibacterial biodegradable Mg-Ag alloys.

The use of magnesium alloys as degradable metals for biomedical applications is a topic of ongoing research and the demand for multifunctional materials is increasing. Hence, binary Mg-Ag alloys were designed as implant materials to combine the favourable properties of magnesium with the well-known antibacterial property of silver. In this study, three Mg-Ag alloys, Mg2Ag, Mg4Ag and Mg6Ag that contain 1.87 %, 3.82 % and 6.00 % silver by weight, respectively, were cast and processed with solution (T4) and aging (T6) heat treatment. The metallurgical analysis and phase identification showed that all alloys contained Mg4Ag as the dominant ß phase. After heat treatment, the mechanical properties of all Mg-Ag alloys were significantly improved and the corrosion rate was also significantly reduced, due to presence of silver. Mg(OH)2 and MgO present the main magnesium corrosion products, while AgCl was found as the corresponding primary silver corrosion product. Immersion tests, under cell culture conditions, demonstrated that the silver content did not significantly shift the pH and magnesium ion release. In vitro tests, with both primary osteoblasts and cell lines (MG63, RAW 264.7), revealed that Mg-Ag alloys show negligible cytotoxicity and sound cytocompatibility. Antibacterial assays, performed in a dynamic bioreactor system, proved that the alloys reduce the viability of two common pathogenic bacteria, Staphylococcus aureus (DSMZ 20231) and Staphylococcus epidermidis (DSMZ 3269), and the results showed that the killing rate of the alloys against tested bacteria exceeded 90%. In summary, biodegradable Mg-Ag alloys are cytocompatible materials with adjustable mechanical and corrosion properties and show promising antibacterial activity, which indicates their potential as antibacterial biodegradable implant materials.

Micro-hardness and mineral loss of enamel lesions after infiltration with various resins: influence of infiltrant composition and application frequency in vitro.

OBJECTIVES: The aim of this in vitro study was to evaluate the influence of infiltrant composition and application frequency on micro-hardness and lesion progression after resin infiltration of artificial enamel lesions. METHODS: In each of 100 bovine enamel samples, three artificial caries lesions were created (pH=4.95, 50 days). After etching two of the lesions (37% phosphoric acid) specimens were randomly allocated to five infiltrants (four experimental infiltrants with different monomer and solvent compositions and penetration coefficients, and one commercial infiltrant [Icon, DMG]). Lesions were then infiltrated and light-cured, and infiltration repeated afterwards for one of the lesions. Infiltrated samples were cut into halves, with one half being demineralised for further 50 days. Micro-hardness (VHN) and integrated mineral loss (ΔZ) were evaluated at baseline and after second demineralisation. Repeated measures ANOVA and paired t-tests were used to analyse influence of material composition and application frequency on micro-hardness and lesion progression (integrated mineral loss difference ΔΔZ). RESULTS: Resin infiltration significantly increased micro-hardness and reduced lesion progression compared to untreated artificial lesions (p<0.05, t-test). Neither micro-hardness nor lesion progression were significantly influenced by material composition (p>0.05, ANOVA). In contrast, twice application resulted in significantly increased micro-hardness and demineralisation resistance of infiltrated lesions (p<0.05, ANOVA). CONCLUSION: Resin infiltration significantly improves micro-hardness and demineralisation resistance of enamel lesions; these effects are significantly enhanced if resins are applied twice. Experimental resins did not outperform the commercial infiltrant. CLINICAL SIGNIFICANCE: This in vitro study demonstrated that resin infiltration significantly increases both micro-hardness and demineralisation resistance of enamel caries lesions. Twice application of the infiltrant seems to increase these effects. In contrast, the composition of the infiltrant had no significant influence on investigated parameters.

Maternal interleukin-6 (-174) C/C polymorphism is associated with chorioamnionitis and cystic periventricular leucomalacia of the preterm infant.

OBJECTIVE: To evaluate the association between maternal interleukin (IL)-6 G(-174)C polymorphism and cystic periventricular leukomalacia (cPVL) of the preterm newborn. STUDY DESIGN: After searching a local database, we recruited 132 preterm infants with diagnosis of cPVL, 44 Caucasian mothers were also recruited to participate in this candidate gene-association study at a single teritary care center. Data related to maternal IL-6 G(-174)C polymorphisms were compared with 41 controls, and furthermore compared with data from umbilical cord blood samples from a consecutive birth cohort of 395 healthy newborns, and published data from Caucasian populations including 1104 adults, respectively. In addition, subgroup analysis was performed in cases with either history of preterm premature rupture of the membranes (PPROM) or clinical chorioamnionitis (CCA). IL-6 genotyping was performed using an allele-specific polymerase chain reaction technique. RESULT: Frequencies of the IL-6 G(-174)C polymorphisms did not differ between cases (GG, 29.5%; GC, 54.5% and CC, 15.9%) and controls (GG, 34.2; GC, 51.2 and CC, 14.6%). Subgroup analysis of 31 cases with history of PPROM (GG, 25.8; GC, 54.8 and CC 19.4%) and controls did not reveal significant differences, but a significantly higher frequency of the CC genotype was found in 23 cases with a history of CCA (34.8%) compared with controls by either univariate (P=0.032; odds ratio 3.11, 95% confidence interval (CI) 1.11 to 8.68) or multivariate analysis (P=0.049, odds ratio 2.54, 95% CI 1.01 to 6.45). These data were confirmed by a comparing the CC genotype frequency to 395 term controls (CC 14.7%, P=0.005) and to the mean CC genotype frequency of 1104 Caucasian adults (CC 15.6%, P<0.0001). CONCLUSION: Frequencies of the IL-6 G(-174)C polymorphisms did not differ between groups. Subgroup analysis revealed an association of the CC genotype with CCA and cPVL in the preterm newborn.

Interleukin-6 G(--174)C polymorphism is associated with mental retardation in cystic periventricular leucomalacia in preterm infants.

OBJECTIVE: The fetal inflammatory response syndrome involving proinflammatory cytokines such as interleukin-6 (IL-6) has been associated with cystic periventricular leukomalacia (cPVL). We evaluated whether the development of cPVL is associated with the IL-6 G(-174)C polymorphism. METHODS: 52 children with cPVL were compared to 46 preterm and 395 term controls using retrospective cohort analysis. IL-6 genotyping was performed using an allele specific polymerase chain reaction technique. RESULTS: IL-6 G(-174)C polymorphisms did not differ between groups, but an association between mental retardation and the IL-6 C/C (78%) and G/C (43%) genotypes compared to the G/G (25%) genotype was found (p = 0.003 and 0.043, respectively; RR 3.11 (95% CI 1.54 to 6.29) and 1.79 (95% CI 1.10 to 2.92), respectively). CONCLUSIONS: The IL-6 (-174) C/C and G/C genotypes were associated with mental retardation in cPVL and seem to modify the severity of perinatal brain injury.

[The use of assessment instruments in the rehabilitation of accident victims]. / Der Einsatz von Assessmentverfahren in der Rehabilitation von Unfallverletzten.

Within the course of rehabilitation management the Verwaltungs-Berufsgenossenschaft (VBG) has started to measure the outcomes to assure the quality of rehabilitation processes using assessment instruments. The measures included some aspects of activity and participation in accordance with the International Classification of Functioning, Disability and Health (ICF). The present paper describes the generic and condition-specific instruments used in the this study to assess the health-related quality-of-life, discusses their selection and illustrates their incorporation into management practice. The assessment process constitutes a consistent system to prove the effects of rehabilitation and their persistence. The first experience shows that the assessment-based quality management system can be recommended for permanent modelling of structures, processes and outcomes to improve the efficacy and cost-effectiveness of rehabilitation.

Procalcitonin and interleukin-6 in the diagnosis of early-onset sepsis of the neonate.

UNLABELLED: The reliability of procalcitonin (PCT) and interleukin-6 (IL-6) was determined and compared with that of C-reactive protein (CRP) in the diagnosis of early-onset sepsis of the neonate within the first 12 h of life. ROC analysis of values of 41 neonates with blood-cultures-positive and clinical sepsis compared with those of 27 uninfected neonates revealed sensitivities for PCT (> or = 6 ng/mL), IL-6 (> or = 60 pg/mL), and CRP (> or = 2.5 mg/L) of 77%, 54%, and 69% and specificities of 91%, 100% and 96%, respectively. Sensitivity of CRP at > or = 8 mg/L was 49% (p = 0.012 compared to PCT). CONCLUSION: PCT was the most sensitive diagnostic parameter in the diagnosis of early-onset sepsis within 12 h of life.

Plaque formation on surface modified dental implants. An in vitro study.

Bacterial adhesion on titanium implant surfaces has a strong influence on healing and long-term outcome of dental implants. Parameters like surface roughness and chemical composition of the implant surface were found to have a significant impact on plaque formation. The purpose of this study was to evaluate the influence of two physical hard coatings on bacterial adhesion in comparison with control surfaces of equivalent roughness. Two members of the oral microflora, Streptococcus mutans and Streptococcus sanguis were used. Commercially pure titanium discs were modified using four different surface treatments: physical vapour deposition (PVD) with either titanium nitride (TiN) or zirconium nitride (ZrN), thermal oxidation and structuring with laser radiation. Polished titanium surfaces were used as controls. Surface topography was examined by SEM and estimation of surface roughness was done using a contact stylus profilometer. Contact angle measurements were carried out to calculate surface energy. Titanium discs were incubated in the respective bacterial cell suspension for one hour and single colonies formed by adhering bacteria were counted by fluorescence microscopy. Contact angle measurements showed no significant differences between the surface modifications. The surface roughness (Ra) of all surfaces examined was between 0.14 and 1.00 microm. A significant reduction of the number of adherent bacteria was observed on inherently stable titanium hard materials such as TiN and ZrN and thermically oxidated titanium surfaces compared to polished titanium. In conclusion, physical modification of titanium implant surfaces such as coating with TiN or ZrN may reduce bacterial adherence and hence improve clinical results.

[Blueberry muffin baby: the pathogenesis of cutaneous extramedullary hematopoiesis]. / Blueberry-Muffin-Baby. Zur Pathogenese der kutanen extramedullären Hämatopoese.

Two neonates exhibited the clinical picture of the "blueberry muffin baby" at delivery. The integument manifested petechiae and purpuric magenta-colored macules, papules, and plaques, as well as blueberry-colored ecchymoses. These findings led to the diagnosis of a connatal cytomegalovirus infection and fetal erythroblastosis, respectively. The hemorrhagic-purpuric looking skin lesions reflected extramedullary hematopoiesis with ultrastructural study disclosing evidence of both erythro- and granulopoietic lineage. For the first time, we were able to demonstrate that complexes of red cells in various stages of maturation can occur in the skin, similarly to the erythroblastic islands of the bone marrow. In the pathogenesis of extramedullary hematopoiesis, mechanisms underlying the reconstitution of blood cells must be considered. These may reactivate hematopoiesis in organs where it previously occurred in embryonic and fetal life. Possible causative factors may be great compensatory demand, deficient replacement, or loss or dysfunction of corpuscular blood elements. This would explain the occurrence of this disease entity in conjunction with etiologically completely heterogeneous systemic diseases.

Scanning electron microscopical analysis of laser-treated titanium implant surfaces--a comparative study.

Design and surface qualities of titanium implants are of vital importance for long-term stability following implantation. Four different implant surfaces treated individually were analyzed with special attention focused on laser surface treatment. Surfaces with machine roughness, titanium spray coating, treated by aluminum oxide and treated by laser were examined individually. Evaluation of the surface was carried out by electron microscope examination and mechanical profilometry. The EDS analysis determined the degree of contamination of the implant surface. Electron microscope examination showed that the titanium plasma spray as well as the laser-treated implants have optimum surface qualities: a secondary and tertiary structure with micro-roughness of 10 mm and roughness ranging from 0.5 to 4 mm. The least contamination was found for machine rough surfaces as well as those treated by laser. The other implants showed contamination corresponding to the method of surface treatment. In summary the optimal surface structure with the least contamination was found for the laser-treated titanium surface. Similar surface purity was found for the machine rough surfaces. An optimal structure was also achieved by the titanium plasma spray method, however, at the cost of surface purity.

"Allergen engineering": variants of the timothy grass pollen allergen Phl p 5b with reduced IgE-binding capacity but conserved T cell reactivity.

One problem of conventional allergen-specific immunotherapy is the risk of anaphylactic reactions. A new approach to make immunotherapy safer and more efficient might be the application of engineered allergens with reduced IgE-binding capacity but retained T cell reactivity. Using overlapping dodeca-peptides, the dominant T cell epitopes of the timothy grass pollen allergen Phl p 5b were identified. By site-directed mutagenesis outside these regions, point and deletion mutants were generated. Allergen variants were analyzed for IgE-binding capacity with sera of different grass pollen allergic patients by Western blotting, Dot blotting, and EAST inhibition test, and for histamine releasing capacity with peripheral blood basophils from different patients. The deletion mutants revealed significantly reduced IgE reactivity and histamine releasing capacity, compared with the wild-type Phl p 5b. Furthermore, in vivo skin prick tests showed that the deletion mutants had a significantly lower potency to induce cutaneous reactions than the wild-type Phl p 5b. On the other hand, T cell clones and T cell lines from different allergic patients showed comparable proliferation after stimulation with allergen variants and wild-type Phl p 5b. Considering their reduced anaphylactogenic potential together with their conserved T cell reactivity, the engineered allergens could be important tools for efficient and safe allergen-specific immunotherapy.

Detection and quantification of group 4 allergens in grass pollen extracts using monoclonal antibodies.

BACKGROUND: Grass pollen extracts are complex mixtures consisting of different major allergenic and non-allergenic components. Phl p 4 is an important allergen, because more than 75% of grass pollen allergic patients produce specific IgE antibodies against group 4 allergens. OBJECTIVE: This study was designed to investigate the specificity of monoclonal antibodies (MoAbs) produced against Phl p 4 and to verify the presence of group 4-like proteins in different grass pollen. Furthermore the usefulness of MoAbs for quantification of group 4 allergens was studied. METHODS: Group 4 analogues were investigated by immunoblotting and ELISA inhibition using three MoAbs. The specificity of antibodies was studied using isolated group 1 and group 5 allergens. Quantification of group 4 allergen was achieved by a two-site solid-phase ELISA. Phl p 4 was purified from whole pollen extract by chromatographic or electrophoretic techniques and used as standard. RESULTS: The MoAbs studied bound strongly to proteins from timothy grass pollen extract at a mw of 55 kDa and a pI of 9.0-9.3. Phl p 4 homologes with similar mw were detected in Dactylis glomerata, Festuca pratensis, Holcus lanatus, Poa pratensis, Lolium perenne. Epitope mapping showed that all three MoAb recognized unrelated regions on Phl p 4. A two-site binding ELISA using MoAbs was developed for determination of Phl p 4 in Phleum pratense extracts. The method was able to evaluate group 4 in mass units with a working range between 150 and 2000 ng/mL. The absolute amounts of group 4 in extracts of several grasses varied considerably but was always-less than 1% of the total protein. CONCLUSION: Group 4 homologes are present in the various grass extracts but to different extents. The group 4 ELISA could be very useful as a additional tool for providing information concerning the composition of grass pollen extracts.

In situ localization of a high molecular weight cross-reactive allergen in pollen and plant-derived food by immunogold electron microscopy.

BACKGROUND: A high molecular weight (60 kd) allergen has been recently identified as a cross-reactive moiety in pollen and plant-derived food. While the cross-reactive allergen has been characterized by immunochemical techniques, little is known concerning its biologic properties. OBJECTIVE: In this investigation we studied the in situ localization of the 60 kd cross-reactive allergen in tree, grass, and weed pollen, as well as in plant-derived food (apple and celery). METHODS: A monoclonal antibody (3A4) that was raised against the major mugwort pollen allergen, Art v 1, was used to demonstrate the presence of related allergens in nitrocellulose-blotted pollen and plant-food extracts. The tissue localization of the cross-reactive allergen was investigated by immunogold electron microscopy. RESULTS: Monoclonal antibody 3A4 recognized IgE epitopes of the 60 kd mugwort allergen and cross-reacted with moieties of comparable molecular weights in birch and timothy grass pollen, as well as in apple and celery extracts. In pollen and plant-derived food the allergen could be localized intracellularly in ribosome-rich areas in the mitochondria and the nucleus. No labeling was observed in the pollen or cell walls or in organelles that are engaged in storage (e.g., starch granules and lipid particles). CONCLUSION: Tree, grass, and weed pollen, as well as plant-derived foods, contain a high molecular weight Art v 1-cross-reactive allergen that maps to similar cell compartments.

Mapping of T-cell epitopes of Phl p 5: evidence for crossreacting and non-crossreacting T-cell epitopes within Phl p 5 isoallergens.

BACKGROUND: Group 5 allergens represent major grass pollen allergens because of their high sensitization indices. The identification of T-cell epitopes of these allergens is a prerequisite for the design of immunotherapeutic strategies based on peptide vaccination or modified allergens with conserved T-cell epitopes. OBJECTIVE: This study was undertaken to determine T-cell epitopes on Phl p 5 major pollen allergen of timothy grass (Phleumn pratense). METHODS: T-cell lines (TCLs) and T-cell clones (TCCs), specific to Phl p 5, were established from the peripheral blood of 18 patients allergic to grass pollen. All TCCs were mapped for epitope specificities using 178 overlapping dodecapeptides representing the primary structures of two isoforms of Phl p 5 (Phl p 5a and Phl p 5b). Phenotype and cytokine production profiles of TCCs were tested. Selected TCCs were analysed for HLA class II restriction. RESULTS: A total of 82 TCCs were isolated. All TCCs displayed the helper cell (TH) phenotype. Their reactivity with two recombinant expressed isoforms of Phl p 5a and Phl p 5b was heterogeneous. The epitope specificity of the TCCs was then revealed. Nineteen T-cell epitopes could be identified on Phl p 5. Eighty-one percent of mapped TCCs recognized three T-cell reactive regions on the Phl p 5 allergen. Some TCCs were reactive with isoepitopes presenting on Phl p 5a as well as Phl p 5b. Allergen-specific stimulation induced a TH0-like type of cytokine production in 25 of 50 TCCs. Almost all TCCs secreted high concentrations of interleukin-13. CONCLUSION: Phl p 5, a major grass pollen allergen, contains several T-cell epitopes. Some epitope regions were recognized by several patients. Epitope recognition pattern could not be correlated with special HLA class II haplotypes. T-cell stimulating isoepitopes were found at corresponding regions of Phl p 5a and Phl p 5b isoforms.

Novel bradykinin signalling events in PC-12 cells: stimulation of the cAMP pathway leads to cAMP-mediated translocation of protein kinase Cepsilon.

In the rat pheochromocytoma cell line PC-12, bradykinin (BK) stimulated phosphatidylinositol hydrolysis by 4-5-fold and, additionally, intracellular cAMP accumulation by approx. 1.6-fold. EC50 values for BK were 3 nM and 2 nM respectively. The BK-induced increase in cAMP accumulation was paralleled by a 1.6-fold increase in protein kinase A (PKA) activity. The time course of BK-stimulated inositol phosphate formation was rapid (t1/2<1 min), whereas the BK-induced cAMP accumulation was lagging (t1/2 approx. 6 min). The effect of BK on the cAMP pathway was independent of pertussis toxin, excluding an indirect stimulation of adenylate cyclase via betagamma-complexes from Gi or Go proteins. Two different protein kinase C (PKC) inhibitors, bisindolylmaleimide and Ro 31-820, failed to prevent BK-induced cAMP accumulation, and exclude PKC as mediator of BK action on adenylate cyclase. In contrast, the stimulatory effect of BK on cAMP accumulation was completely abolished by two calmodulin antagonists, chlorpromazine and ophiobolin, suggesting an indirect, Ca2+/calmodulin-mediated effect of BK on the cAMP pathway. In addition, exposure of PC-12 cells to BK resulted in a translocation of the PKC isoforms alpha, delta, epsilon and zeta displaying different kinetics. The BK-induced translocations of the PCDs alpha and delta were rapid and biphasic, whereas the PKCs epsilon and zeta revealed a slower and slightly transient translocation in response to BK. The BK-elicited translocation of PKCepsilon, but not that of the PKCs alpha, delta and zeta, was prevented by two different inhibitors of adenylate cyclase, 2',5'-dideoxyadenosine and MDL-12,330A, as well as the PKA inhibitor adenosine 3':5'-monophosphothioate. These findings suggest that the BK-induced translocation of novel (n)PKCepsilon is mediated via the cAMP pathway. Since nPKCepsilon appears to regulate neurite outgrowth in PC-12 cells [Hundke, McMahon, Dadgar and Messing (1995) J. Biol. Chem. 270, 30134-30140] our results provide evidence for a novel signalling mechanism that might be involved in BK-induced neuronal differentiation of PC-12 cels.

[Improving the design of an alloplastic epithelialized tracheal prosthesis]. / Untersuchungen zur Verbesserung des Designs eines alloplastischen epithelisierten Tracheaersatzes.

Replacement of the tracheal conduit remains an unresolved problem. The microporous material expanded polytetrafluorethylene (ePTFE) is suitable for tracheal reconstruction. The aim of our study was to improve the limited mechanical properties of this material by incorporating reinforcement elements and to examine the influence of these elements on host incorporation and epithelialization. In so dours ePTFE prostheses were reinforced with lonomer cement and porous high density polyethylene (pHDPE) rings and implanted into the neck muscle of miniature pigs. One of these prostheses was epithelialized by a cell seeding technique and was thus placed into a tracheal defect. Results were examined grossly by endoscopy and than by light and scanning electron microscopy. The shapes of both types of prostheses showed a high stability. The reinforcement elements did not impair bioincorporation or the ability to epithelialize. In vivo interposition of an incorporated and epithelialized prosthesis to a host led to cell differentiation. The improved biomechanical properties of the prostheses waid and the reproducible formation of epitheliums are important advances in the solution of effectively correcting tracheal defects.

Identification of a 60 kd cross-reactive allergen in pollen and plant-derived food.

BACKGROUND: Cross-reactive IgE antibodies were found to be responsible for allergic reactions in patients allergic to pollen on ingestion of food (oral allergy syndrome). So far, the major birch pollen allergen Bet v 1 and birch profilin (Bet v 2) were identified as relevant cross-reactive allergens. OBJECTIVE: In this study we attempted to identify additional cross-reactive plant allergens, which could be responsible for food intolerance in patients allergic to pollen. METHODS: Monoclonal antibodies specific for the major mugwort pollen allergen, Art v 1, representing a 60 kd glycoprotein, were used to detect cross-reactive allergens in other pollens and plant-derived food. The amino acid compositions of the cross-reactive structures were determined, and their resistance against trypsin treatment was investigated. In addition, IgE immunoblot inhibitions were done with the 60 kd mugwort pollen allergen. RESULTS: Monoclonal antibodies specific for the major mugwort pollen allergen, Art v 1, cross-reacted with proteins of comparable molecular weight in fruit and vegetables. Preadsorption of patients' sera with the 60 kd mugwort allergen led to a reduction of IgE binding to components of a similar molecular weight present in different pollen (birch, timothy grass), fruit (apple, peanuts), and vegetable (celery) extracts and reduced IgE binding to apple, kiwi, and celery as determined by RAST inhibitions. CONCLUSION: A cross-reactive plant panallergen, possibly identical to the major mugwort pollen allergen, Art v 1, is described. The allergen represents a protein of approximately 60 kd present in various pollen and plant foods; which is distinct from Bet v 1 and profilin and hence may represent a novel cross-reactive allergen in the oral allergy syndrome.