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Biomedical subjects

J Meyle

Publications and source records attributed to J Meyle.

At least 19 recordsLinked to original sources
PubMed1997

Genetic studies of syndromes with severe periodontitis and palmoplantar hyperkeratosis.

The Papillon-Lefèvre and Haim Munk syndromes are characterized by the presence of both palmoplantar hyperkeratosis (PPK) and severe early onset periodontitis. It is the early onset periodontal disease component that distinguishes these from other more common forms of PPK. It has been proposed that the periodontal disease component may be a casual association in individuals with PPK. Genetic syndromes with palmoplantar keratosis and severe ealry onset periodontitis may be due to specific bacterial infections in individuals with PPK. Recently, keratin gene mutations have been identified in several conditions typified by palmoplantar keratosis. The present study sought to test the hypothesis that a keratin gene defect similar to those previously identified in other PPK conditions is responsible for the Haim Munk and the Papillon. Lefèvre syndromes. We have performed genetic linkage studies to test for linkage between polymorphic DNA loci within 2 cytokeratin gene families and the disease phenotype in Haim Munk syndrome and Papillon-Lefèvre syndrome. Families with individuals segregating for the Haim Munk syndrome and the Papillon-Lefèvre syndrome were examined to determine disease status, and genotyped for microsatellite DNA markers closely linked to the acidic (type I) and the basic (type II) cytokeratin genes on chromosomes 12 and 17. Genotype data were evaluated for microsatellite allele homozygosity in affected individuals. Results of these preliminary genetic studies suggest that the gene defect in Haim Munk syndrome is not due to a gene defect in either the type I or the type II keratin gene clusters. These findings suggest that Haim Munk syndrome may be genetically distinct from other more common forms of PPK that have been linked to the cytokeratin gene families, and suggest that mutations in genes other than keratin genes are responsible. Additional family studies are needed to confirm these preliminary findings.

Adult↗
PubMed1996

Influence of the surface structure of titanium materials on the adhesion of fibroblasts.

Of utmost importance for the successful use of an implant is a good adhesion of the surrounding tissue to the biomaterial. In addition to the surface composition of the implant, the surface topography also influences the properties of the adherent cells. The aim of this investigation was thus to study the influence of the surface structure of the substrate on the formation of focal contacts and on the orientation of cultivated gingival fibroblasts by means of fluorescence microscopy. A further goal was to determine the effect of the material composition on the cell shape, on the assumption that in each case a lengthening of the cells can be expected to provide a more favourable adhesion behaviour than a spherical cell shape. In order to describe the shape of the cell, a shape factor was defined which was calculated from the area covered by the cells and from their circumference. To determine the influence of the surface structure, substrate platelets of cp-titanium, TiAl6V4 and TiTa30 were ground. Onto these specimens human gingival fibroblasts of the 5th to 7th passages were cultivated. After a culture time of two days the cells were fixed and stained. The number of orientated cells was determined as a function of the surface roughness of the substrate. The number of orientated cells was shown to increase---independent of the material---with increasing roughness of the ground substrate. On a polished surface the number of orientated cells was 11% (average peak-to-valley height 0.04 microns); at a peak-to-valley height of 1.36 microns the number of orientated cells increased to 72%. It could be observed that the orientated cells had a higher density of focal contacts where they were in contact with the edges of the grinding grooves. In order to determine the effect of the surface composition, gingival fibroblasts were cultured for 14 d on polished substrate specimens of cp-titanium, TiAl6V4 and TiTa30 and examined for differences in shape. The cells grown on cp-titanium and on TiTa30 had shape factors of 1.76 and 1.58 respectively, whereas those grown on TiAl6V4 had a shape factor of 0.93. The unfavourable spherical shape of the fibroblasts (resulting in a poor adhesion) grown on TiAl6V4 after a culture period of 14 d may be the result of a locally increased vanadium concentration in the substrate, with an accompanying increase in the release of toxic vanadium ions.

Alloys↗
PubMed1996

Partial expression of the Papillon-Lefèvre syndrome in 2 unrelated families.

The Papillon-Lefèvre syndrome (PLS) is a rare, autosomal recessive trait that is characterized by palmar plantar keratosis (PPK) and severe, early onset periodontitis, affecting both deciduous and permanent dentitions. The clinical presentation of PLS is variable; the disease occurs so infrequently as to limit clinical cases for study. The exception is a few families with extensive consanguinity in which numerous cases occur. Of particular interest to mapping the genetic origin of the syndrome is the co-expression of the major traits of hyperkeratosis and periodontitis, and their severity. In this paper, we report 2 families with multiple affected individuals from geographically remote areas. A large extended family, from the Cochin region of India, currently residing in Israel, in which there is documented consanguinity and a family from the southwest region of Germany. In each family, 1 individual presents with hyperkeratotic lesions with the complete absence of periodontal lesions. Further, the difference in severity of the hyperkeratotic lesions between families is marked, and one sibling in the German family expressed rapid, early onset periodontitis in the absence of PPK. The genetic nature and penetrance of the genetic defect are discussed.

Adult↗
PubMed1996

Effects of various hygiene procedures on the surface characteristics of titanium abutments.

The use of cleaning instruments on titanium implants may cause undesired surface alterations. In a qualitative and quantitative assessment of these alterations, 5 titanium implant abutments were treated with a steel curet, a prototype pure titanium curet, an air abrasive polishing system, and an ultrasonic system. Custom-made polymer templates, used to secure the curet to a vertical guide bar and a spring scale to maintain a constant instrument pressure, guaranteed a standardized procedure and reproducible results. The ultrasonic and the air abrasive polishing method were also standardized. Evaluation by scanning electron microscopy (SEM) revealed surface alterations for all instruments and systems except the plastic curet, which did not roughen the surface at all. The confocal laser-scanning microscope allows a 3-dimensional reproduction of these surface alterations and their direct measurement. The profilometric tracing was not sensitive enough to register the minor effects caused by the titanium curet and the air abrasive polishing system. Dimensions of the resulting surface microstructure could be determined with the laser-scanning microscope. Since the influence of such surface defects on the peri-implant tissue reaction is unpredictable, the titanium curet and the air abrasive system can only be recommended with restrictions. The steel curet and the ultrasonic system proved to be totally unsuitable for cleaning titanium implants.

Curettage↗
PubMed1996

Radiographic imaging of the hard palate and maxillary third molars with spiral tomography: a novel technique of patient positioning.

The Scanora spiral tomography system can be used to solve a range of imaging problems in the maxillofacial region. However, the system has no specific programs for imaging bony lesions of the hard palate or medially and cranially displaced maxillary third molars. New patient-positioning techniques were therefore developed on the basis of phantom radiographs, and their successful application in patients is presented. With the novel techniques, good radiographic representations of the hard and soft palates in the posteroanterior and lateral projections and of maxillary third molars were achieved.

Female↗
PubMed1995

Variation in contact guidance by human cells on a microstructured surface.

Contact guidance induced by the surface topography of the underlying substratum influences the interaction of tissue cells with implanted material. It was the aim of this study to compare the reaction of different human cells on the same surface microtexture. After staining with fluoresceinediacetate, the orientation of human fibroblasts, gingival keratinocytes, neutrophils, monocytes, and macrophages on a regular surface microstructure of 1 microns pitch and 1 microns depth was analyzed by fluorescence microscopy. Contact guidance could not be observed in the experiments with keratinocytes and neutrophils, but 100% of the fibroblasts and approximately 20% of the monocytes and macrophages reacted with alignment. After 2 h some of the macrophages extended long dendritic cellular processes parallel to the long axis of the microstructures.

Cell Physiological Phenomena↗
PubMed1994

Chemotactic activity of substances derived from antibody-loaded tumor cells on granulocytes.

Chemotactic activity of granulocytes attracted by tumor cells loaded either with anti-ganglioside monoclonal antibodies (mAb) or with antibody-glucose oxidase conjugates (mAb-GO) was investigated. The melanoma cell line SK-Mel-28 which expresses the ganglioside GD3 at high density as well as the neuroectodermal cell line SK-N-LO which expresses GD2 were used for the experiments. In the presence of 50% human AB-serum, antibody-loaded tumor cells induced chemotactic activity on granulocytes, probably due to the generation of C3a/C5a which could be detected in serum incubated with anti-GD3 loaded SK-Mel-28 cells. Both compounds could also be detected in vivo in the plasma of patients suffering from neuroblastoma during therapy with anti-GD2 antibodies. In another set of experiments mAb-GO conjugates generating high amounts of H2O2 in the presence of glucose were bound to these tumor cells. A significant lipid peroxidation could be observed in the simultaneous presence of iron and ascorbate. The lipid peroxidation products were measured as thiobarbituric acid-reactive substances (TBARS) and were also shown to induce chemotactic effects on granulocytes.

ABO Blood-Group System↗
PubMed1994

Interleukin-1 beta concentration of gingival crevicular fluid.

The concentration of interleukin-1 beta is elevated in inflamed gingival tissue. Therefore a method for the measurement of interleukin-1 beta (Il-1 beta) in gingival crevicular fluid (GCF) using a commercially available Il-1 beta ELISA was developed. GCF was collected with periopaper strips and 4 protocols of sampling using filter paper strips were tested; the method with a recovery rate of 111.9% (SD: +/- 14.5%) was chosen for subsequent analysis of all samples. Il-1 beta concentration in GCF of periodontitis patients and a healthy control group was determined. Patients (n = 19, mean age: 29.3 years) had not been treated. The healthy control group (n = 14, mean age: 22.8 years) showed, after a hygiene regimen of 2 weeks, no clinical signs of gingival/periodontal inflammation. Probing depth, clinical attachment level, bleeding upon probing, and a modified plaque index were recorded. Il-1 beta could be detected in all GCF samples. The concentration ranged between 22.8 ng/ml and 150 ng/ml in the healthy control group and between 85.8 ng/ml and 882.2 ng/ml in the periodontitis patients. No sex-related differences were noted. According to our present results the determination of GCF Il-1 beta concentration is possible using commercially available test kits if the principle of sample preparation is adapted to the specific requirements of GCF analysis.

Adolescent↗
PubMed1993

Fibroblast anchorage to microtextured surfaces.

The contact between tissue and the implanted biomaterial is influenced by the micromorphology of the implant surface as well as biomechanical reactions. This effect is mediated by subcellular morphological structures and can affect the anchorage of the material inside the body of the host. The aim of the present study was to ascertain by transmission electron microscopy how human gingival fibroblasts interact with surface events. A special replica technique was used to produce a line pattern of 1 micron pitch with a depth of 1 micron. It was demonstrated, by transmission electron microscopy, that cells seeded on this surface extended cellular processes into the grooves, leading to an intensive contact and probably to mechanical interlocking. The typical morphological structures at several points indicated the presence of focal adhesion sites.

Biocompatible Materials↗
PubMed1993

Surface micromorphology and cellular interactions.

Contact guidance induced by the topographical properties of the underlying substratum is of great importance in morphogenesis and also influences the interaction of tissue cells with implanted material. A large body of evidence has accumulated since the first detection of this phenomenon in 1910. Several major hypotheses have been developed to explain the observed cell behaviour. The technological progress enabled researchers to produce pure substrata with a defined and controlled surface microgeometry. Based on these specimens, it could be demonstrated that cytoskeletal structures and receptors forming focal adhesions most likely are involved in contact guidance. In a study using human gingival fibroblasts, the reaction of these cells to a regular surface microstructure of 1 micron pitch and 1 micron depth was tested. After two days on the microstructured samples, all the cells showed a strong alignment to the topography of the surface. Transmission electron microscopy revealed that the cells either bridged the grooves or conformed to the surface structures. The latter confirms earlier investigations with porous subcutaneous implants, where the inflammatory reaction and the formation of a fibrous tissue capsule was reduced due to enhanced tissue adhesion.

Cell Adhesion↗
PubMed1992

Influence of oral hygiene on elastase concentration of gingival crevicular fluid.

PMN elastase concentration of gingival crevicular fluid (GCF) was investigated in 11 healthy volunteers before professional tooth cleaning and after a 5-week period of intensive oral hygiene. GCF was collected using filter paper strips and the enzyme concentration was evaluated by the ELISA-technique. Intensive daily oral hygiene led to a considerable improvement in the clinical indices and to a reduction in the concentration of elastase in GCF. Despite the changes in the oral hygiene status, functional elastase was still present in the samples at the end of the experiment. This could mean that even at clinically healthy sites there is a lack of alpha-1-proteinase inhibitor, the major serum protein inactivating PMN elastase.

Adult↗
PubMed1991

Oral manifestations of Crohn's disease. An analysis of 79 cases.

We report four new cases of oral manifestation in Crohn's disease (CD) and evaluate 75 reported cases for morphology and site of oral and intestinal manifestations of CD, clinical manifestation, and treatment. Oral CD was the presenting symptom in 43 of 72 (60%) patients and relapsed in 34 of 60 (57%). Median age at presentation was 22 (range 6-57) years, and males were affected more often (1.85:1, male:female ratio). From a total of 228 oral lesions in 79 patients, lips (57 lesions), gingiva (40 lesions), vestibular sulci (31 lesions), and buccal mucosa (25 lesions) were the sites most frequently affected. Edema (62 lesions), ulcers (57 lesions), and polypoid papulous hyperplastic mucosa (45 lesions) were the most common type of lesions. The rate of granuloma detection was high in oral (67-77%) and intestinal lesions (45-71%). A total of 66 courses of drug therapy in 51 patients were analyzed. Complete remission of oral symptoms was achieved by systemic steroids and/or azathioprine in 13 of 26 (50%) patients, whereas strictly topical treatment with steroids resulted in complete remission of oral symptoms in 7 of 12 (58%). We conclude that oral CD exhibits a characteristic morphologic appearance, as often as not preceding intestinal symptoms in adolescents and young adults. Thus, patients with orofacial granulomatosis CD should be vigorously searched for by complete gastrointestinal endoscopic investigation. Oral CD may cause disabling pain and facial distortion, and results of treatment remain unrewarding. In the absence of data from controlled therapeutic trials, systemic steroids and/or azathioprine are recommended if topical treatment has failed to control symptoms.

Adolescent↗
PubMed1990

Assay of ascorbic acid in human crevicular fluid from clinically healthy gingival sites by high-performance liquid chromatography.

The volume of fluid on filter paper strips was measured with a Periotron, eluted, and the ascorbic acid measured by chromatography. In preliminary experiments, pre-impregnation of the strips with citric acid increased the recovery of standard ascorbic acid from 37 to 89% and significantly reduced loss of water from the strips over a 3 min period. Samples of crevicular fluid were then collected from clinically healthy gingival sites of 21 healthy volunteers using pre-impregnated strips and assayed for ascorbic acid concentration, together with samples of blood plasma. The mean ascorbic acid concentration in gingival crevicular fluid (207.3 mumol/l; SD: +/- 81.8) was significantly higher (p less than 0.001) than the corresponding plasma concentration (mean 72 mumol/l; SD: +/- 23.3).

Ascorbic Acid↗
PubMed1990

Molecular analysis of periodontal pathogens.

Both Bacteroides gingivalis and Actinobacillus actinomycetemcomitans have been implicated in the destruction of periodontal tissues. To understand better the role putative virulence factors from the two bacterial species may play in an infection, the collagenase gene from Bact. gingivalis and the leucotoxin gene from A. actinomycetemcomitans were cloned. As it is intended to generate strains carrying defined mutations in these genes for in vitro and in vivo experiments, extensive restriction mapping and sequence analyses of these clones are being undertaken. Furthermore a conjugation system for Bact. gingivalis and A. actinomycetemcomitans will be established.

Actinobacillus↗
PubMed1990

[Acoustic feedback for probing at constant force].

Probing of the gingival crevice is generally recognized as the most important diagnostic procedure in periodontitis. Reliable measurements are only possible by probing at constant force. A freshly isolated porcine mandible was used to test, if acoustic feedback enhances the reliability of probing. Our results indicate that the feedback significantly reduces the total probing force and also the variance between single measurements.

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