AFM stiffness nanotomography of normal, metaplastic and dysplastic human esophageal cells.

The mechanical stiffness of individual cells is important in tissue homeostasis, cell growth, division and motility, and the epithelial-mesenchymal transition in the initiation of cancer. In this work, a normal squamous cell line (EPC2) and metaplastic (CP-A) as well as dysplastic (CP-D) Barrett's Esophagus columnar cell lines are studied as a model of pre-neoplastic progression in the human esophagus. We used the combination of an atomic force microscope (AFM) with a scanning confocal fluorescence lifetime imaging microscope to study the mechanical properties of single adherent cells. Sixty four force indentation curves were taken over the nucleus of each cell in an 8 x 8 grid pattern. Analyzing the force indentation curves, indentation depth-dependent Young's moduli were found for all cell lines. Stiffness tomograms demonstrate distinct differences between the mechanical properties of the studied cell lines. Comparing the stiffness for indentation forces of 1 nN, most probable Young's moduli were calculated to 4.7 kPa for EPC2 (n = 18 cells), 3.1 kPa for CP-A (n = 10) and 2.6 kPa for CP-D (n = 19). We also tested the influence of nuclei and nucleoli staining organic dyes on the mechanical properties of the cells. For stained EPC2 cells (n = 5), significant stiffening was found (9.9 kPa), while CP-A cells (n = 5) showed no clear trend (2.9 kPa) and a slight softening was observed (2.1 kPa) in the case of CP-D cells (n = 16). Some force-indentation curves show non-monotonic discontinuities with segments of negative slope, resembling a sawtooth pattern. We found the incidence of these 'breakthrough events' to be highest in the dysplastic CP-D cells, intermediate in the metaplastic CP-A cells and lowest in the normal EPC2 cells. This observation suggests that the microscopic explanation for the increased compliance of cancerous and pre-cancerous cells may lie in their susceptibility to 'crumble and yield' rather than their ability to 'bend and flex'.

Digital transversal slice imaging in dental-maxillofacial radiology: from pantomography to digital volume tomography.

With digital transversal slice imaging (TSI) as a supplementary program to pantomographic devices and digital volume tomography (DVT), images of the viscerocranium are now possible in several planes. The two procedures, TSI and DVT, are complementary. They should be applied where the indication justifies it in dentistry and maxillofacial surgery for diagnostic and forensic purposes. To minimize patient exposure to radiation, computer tomography (CT) should only be used in complex situations of the viscerocranium where soft tissues are involved or in tumor diagnosis.

["Body and soul and friendships destroyed". Behavior therapy of a 14-year-old adolescent with alcohol dependence syndrome]. / "Körper und Seele und Freundschaften kaputt". Verhaltenstherapie eines 14-jährigen Jugendlichen mit Alkoholabhängigkeitssyndrom.

OBJECTIVES: About 250,000 children and adolescents in Germany are dependent upon alcohol or at severe risk of developing an alcohol disorder. Whereas adults who abuse alcohol benefit from a variety of therapy manuals and numerous institutions offering long-term disorder-specific care, the situation with regard to adolescent patients needs to be upgraded. METHODS: We present the behavioral therapy of an alcohol-dependent 14-year-old boy, focusing on a version of Petry's therapy manual for alcoholism (1996) that has been adapted for the treatment of adolescents. The efficacy of worksheets as a supplement to the usual behavior therapy, or social or family interventions in the treatment of alcohol-dependent adolescents is discussed.

Gingivitis in young adults with Actinobacillus actinomycetemcomitans.

High intraoral load of A. actinomycetemcomitans in subjects with no or minimal periodontal disease may induce subtle changes in clinical periodontal conditions. The aim of the present study was to compare, at a site level, clinical conditions in two groups of young adults with plaque-induced gingivitis. In one group, more than 20% subgingival sites harboured cultivable A. actinomycetemcomitans (n=9), whereas in the other group, the organism was present in 20% or fewer subgingival plaque samples (n=8). Whereas no overt differences in clinical conditions could be ascertained, on average, the association between the presence of subgingival plaque and bleeding upon probing was considerably stronger (Mantel-Haenszel's common odds ratio RMH and 95% confidence interval 3.903, 2.951-5.165, P<0.001) in subjects with only a few subgingival sites harbouring A. actinomycetemcomitans as compared to subjects with a widespread intraoral distribution of the organism (R(MH)=1.637, 1.226-2.184, P<0.001). Since the proportion of sites not bleeding upon probing in the presence of supragingival plaque was slightly elevated in these subjects, the present findings may suggest a suppressed inflammatory reaction on supragingival plaque in the presence of a pronounced intraoral load of A. actinomycetemcomitans.

The double-headed mandibular condyle.

The double-headed condylar process is rare. Radiographs of four patients with this type of anomaly and one skeletal specimen are described in this article. Histologic studies in rodents suggest a possible mode of pathogenesis: maldirected muscular pull may lead to the development of an extra mandibular capitulum.