121 research outputs found
Die solitÀre abszedierende Osteomyelitis des Kieferköpfchens: Eine RaritÀt
Zusammenfassung: Fall: Es wird ĂŒber den seltenen Fall einer solitĂ€ren abszedierenden, sekundĂ€r chronischen Osteomyelitis des linken Processus condylaris berichtet. Aus dem Abszessmaterial wurde der Keim Haemophilus aphrophilus isoliert. Therapeutisch erfolgte eine Resektion des Processus condylaris mit Sofortrekonstruktion des Kondylus mithilfe einer Kopfendoprothese. Diskussion: Mögliche Ursachen fĂŒr diese seltene Lokalisation einer sekundĂ€r chronischen Osteomyelitis werden anhand der Literatur aufgearbeitet und dem vorliegenden Fall gegenĂŒbergestellt. Schlussfolgerung: Als mögliche Ursache wird eine Keiminokulation durch die Nadel bei einer LokalanĂ€sthesie, eine bakterielle Kontamination wĂ€hrend der Zahnextraktion oder eine hĂ€matogene Aussaat durch den Extraktionsvorgang angenomme
Malignant minor salivary gland tumors: a retrospective study of 27 cases
PURPOSE: Malignant tumors of the intra-oral minor salivary glands are uncommon. The aim of this study was to give information concerning the clinical features of these tumors, the distribution of location, treatment opportunities, and outcome. METHODS: Twenty-seven patients with malignant salivary gland tumors that were treated between January 1999 and December 2008 were evaluated retrospectively. RESULTS: Of the 27 minor salivary gland carcinomas, 48.1% were adenoid cystic carcinomas (ACC), 29.7% mucoepidermoid carcinomas (MEC), 22.2% adenocarcinomas (ADCA). The most common first symptom was a painless swelling in 60% of the cases, with the second most common symptom being ulcers (28%). Four recurrences and two metastases were found. No recurrence was observed in ADCA. All four patients experiencing a recurrence developed it in the first 3Â years after treatment. CONCLUSION: Wide excision with a clinical margin of 1Â cm and in large tumors, positive surgical margins or perineural infiltration and postoperative radiotherapy (RT) can be recommended; but in order to give exact information concerning the possible benefit from postoperative RT, it needs large prospective multicenter studies. Long-term follow-up controls and in particularly longer than 5Â years in ACC including yearly chest X-rays should be offered to these patients because of late metastasis and recurrences
NanoBiT â and NanoBiT/BRET âbased assays allow the analysis of binding kinetics of Wntâ3a to endogenous Frizzled 7 in a colorectal cancer model
Background and Purpose
Wnt binding to Frizzleds (FZD) is a crucial step that leads to the initiation of signalling cascades governing multiple processes during embryonic development, stem cell regulation and adult tissue homeostasis. Recent efforts have enabled us to shed light on WntâFZD pharmacology using overexpressed HEK293 cells. However, assessing ligand binding at endogenous receptor expression levels is important due to differential binding behaviour in a native environment. Here, we study FZD paralogue, FZD, and analyse its interactions with Wnt-3a in live CRISPR-Cas9-edited SW480 cells typifying colorectal cancer.
Experimental Approach
SW480 cells were CRISPR-Cas9-edited to insert a HiBiT tag on the N-terminus of FZD, preserving the native signal peptide. These cells were used to study eGFP-Wnt-3a association with endogenous and overexpressed HiBiT-FZD using NanoBiT/bioluminescence resonance energy transfer (BRET) and NanoBiT to measure ligand binding and receptor internalization.
Key Results
With this new assay the binding of eGFP-Wnt-3a to endogenous HiBiT-FZD was compared with overexpressed receptors. Receptor overexpression results in increased membrane dynamics, leading to an apparent decrease in binding on-rate and consequently in higher, up to 10 times, calculated Kd. Thus, measurements of binding affinities to FZD obtained in overexpressed cells are suboptimal compared with the measurements from endogenously expressing cells.
Conclusions and Implications
Binding affinity measurements in the overexpressing cells fail to replicate ligand binding affinities assessed in a (patho)physiologically relevant context where receptor expression is lower. Therefore, future studies on WntâFZD binding should be performed using receptors expressed under endogenous promotion
Genetic Influences on Educational Achievement in Cross-National Perspective
There is a growing interest in how social conditions moderate genetic influences on education [geneâenvironment interactions (GxE)]. Previous research has focused on the family, specifically parentsâ social background, and has neglected the institutional environment. To assess the impact of macro-level influences, we compare genetic influences on educational achievement and their social stratification across Germany, Norway, Sweden, and the United States. We combine well-established GxE-conceptualizations with the comparative stratification literature and propose that educational systems and welfare-state regimes affect the realization of genetic potential. We analyse population-representative survey data on twins (Germany and the United States) and twin registers (Norway and Sweden), and estimate genetically sensitive variance decomposition models. Our comparative design yields three main findings. First, Germany stands out with comparatively weak genetic influences on educational achievement suggesting that early tracking limits the realization thereof. Second, in the United States genetic influences are comparatively strong and similar in size compared to the Nordic countries. Third, in Sweden genetic influences are stronger among disadvantaged families supporting the expectation that challenging and uncertain circumstances promote genetic expression. This ideosyncratic finding must be related to features of Swedish social institutions or welfare-state arrangements that are not found in otherwise similar countries
The phosphorous necrosis of the jaws and what can we learn from the past: a comparison of "phossyâ and "bisphossyâ jaw
Introduction: The osteopathology of the jaws associated with bone resorption inhibitors is a current topic that engages a variety of clinical specialists. This has increased after the approval of denosumab for treatment of osteoporosis and skeletal-related events in patients with solid malignancy. Early after the first publications, there is a possible connection between phosphorous necrosis of the jaws, a dreadful industrial disease mentioned, and bisphosphonate-induced pathology. The nineteenth century was the prime time for phosphorus necrosis of match factory workers. Results: This occurrence provides an interesting insight into the medical and surgical profession in the nineteenth century. There are striking parallels and repetition of current and old ideas in the approach to this "new disease.â There are similar examples in case descriptions when compared with today's patients of bisphosphonate-related osteonecrosis of the jaws (BRONJ). Discussion: Phosphorus necrosis was first described in Austria. Soon after this, surgeons in German-speaking countries including well-known clinicians Wegner (1872) and von Schulthess-Rechberg (1879) pioneered the analysis, preventative measures, and treatment of this disease. The tendency at this time was to approach BRONJ as a "special kind of osteomyelitisâ in pretreated and metabolically different bone. Not only the treatment strategy to wait until sequestrum formation with subsequent removal and preventative measures but also the idea of focusing on the periosteum as the triggering anatomical structure may have been adopted from specialists in the nineteenth century. Therefore, phosphorous necrosis of the jaw is an excellent example of "learning from the past.
Precise screw positioning at the mandibular angle: computer assisted versus template coded
BACKGROUND:
Buried intraoral devices for distraction osteogenesis in mandibular deformities have numerous advantages, but success depends on the precise positioning of these devices. Although most centers nowadays use template-guided techniques for precise positioning, computer navigation has been described as a promising technique. Surgical navigation during device placement could become a viable method because it affords certainty in defining a device position.
METHODS:
A clinical situation was simulated by means of mounting a mandible model inside a phantom head. Screws were positioned according to a preoperative plan through transoral and transbuccal approaches, with both template-coded and freehand computer navigation.
RESULTS:
With template-coded navigation, the medium deviation from the planned position was 0.63 mm (range, 0.00-1.24 mm). With commercial freehand surgical computer navigation, the medium deviation was significantly higher at 0.98 mm (range, 0.00-3.13 mm).
CONCLUSIONS:
Computer-assisted surgery can provide a high level of accuracy in the region of the mandibular angle where precision is crucial for buried intraoral distraction devices. However, template-coded guidance does provide a significantly higher level of accuracy and therefore represents the gold standard
Eureka and beyond: mining's impact on African urbanisation
This collection brings separate literatures on mining and urbanisation together at a time when both artisanal and large-scale mining are expanding in many African economies. While much has been written about contestation over land and mineral rights, the impact of mining on settlement, notably its catalytic and fluctuating effects on migration and urban growth, has been largely ignored. African nation-statesâ urbanisation trends have shown considerable variation over the past half century. The current surge in ânewâ mining countries and the slow-down in âoldâ mining countries are generating some remarkable settlement patterns and welfare outcomes. Presently, the African continent is a laboratory of national mining experiences. This special issue on African mining and urbanisation encompasses a wide cross-section of country case studies: beginning with the historical experiences of mining in Southern Africa (South Africa, Zambia, Zimbabwe), followed by more recent mineralizing trends in comparatively new mineral-producing countries (Tanzania) and an established West African gold producer (Ghana), before turning to the influence of conflict minerals (Angola, the Democratic Republic of Congo and Sierra Leone)
Sibling Similarity in Education Across and Within Societies
The extent to which siblings resemble each other measures the omnibus impact of family background on life chances. We study sibling similarity in cognitive skills, school grades, and educational attainment in Finland, Germany, Norway, Sweden, the United Kingdom, and the United States. We also compare sibling similarity by parental education and occupation within these societies. The comparison of sibling correlations across and within societies allows us to characterize the omnibus impact of family background on education across social landscapes. Across countries, we find larger population-level differences in sibling similarity in educational attainment than in cognitive skills and school grades. In general, sibling similarity in education varies less across countries than sibling similarity in earnings. Compared with Scandinavian countries, the United States shows more sibling similarity in cognitive skills and educational attainment but less sibling similarity in school grades. We find that socioeconomic differences in sibling similarity vary across parental resources, countries, and measures of educational success. Sweden and the United States show greater sibling similarity in educational attainment in families with a highly educated father, and Finland and Norway show greater sibling similarity in educational attainment in families with a low-educated father. We discuss the implications of our results for theories about the impact of institutions and income inequality on educational inequality and the mechanisms that underlie such inequality
- âŠ