A strategy for the modularization of courseware

In order to enable courseware reuse, learning platforms nowadays require the materials to be decomposed into small independent learning units. When trying to fulfill this need, authors face the problem of not knowing how to determine suitable learning objects in their content. What is the appropriate size of one such object? The rather general and abstract definitions for learning objects found in the literature are not very helpful for answering this question. What authors need is an operational definition, which can be directly applied to the learning materials. This paper proposes such a set of formal yet practical definitions by describing learning objects along their contents and resource type and shows how these definitions are used by our platform, SCORE

Alterations in macrophage polarization in the craniofacial and extracranial skeleton after zoledronate application and surgical interventions – an in vivo experiment

PurposeMedication-related osteonecrosis occurs exclusively in the jaw bones. However, the exact pathogenesis of medication-related osteonecrosis of the jaw (MRONJ) and the unique predisposition of the jaw bones have not been elucidated, making its treatment a challenge. Recent evidence indicates that macrophages might play a pivotal role in MRONJ pathogenesis. The aim of the present study was to compare the macrophage populations between the craniofacial and extracranial skeleton and to investigate the changes induced by zoledronate (Zol) application and surgical interventions.Materials and methodsAn in vivo experiment was performed. 120 wistar rats were randomized to 4 groups (G1, G2, G3, G4). G1 served as an untreated control group. G2 and G4 received Zol injections for 8 weeks. Afterwards, the right lower molar of the animals from G3 and G4 was extracted and the right tibia osteotomized followed by osteosynthesis. Tissue samples were taken from the extraction socket and the tibia fracture at fixed time points. Immunohistochemistry was conducted to determine the labeling indexes of CD68+ and CD163+ macrophages.ResultsComparing the mandible and the tibia, we observed a significantly higher number of macrophages and a heightened pro-inflammatory environment in the mandible compared to the tibia. Tooth extraction caused an increase of the overall number of macrophages and a shift toward a more pro-inflammatory microenvironment in the mandible. Zol application amplified this effect.ConclusionOur results indicate fundamental immunological differences between the jaw bone and the tibia, which might be a reason for the unique predisposition for MRONJ in the jaw bones. The more pro-inflammatory environment after Zol application and tooth extraction might contribute to the pathogenesis of MRONJ. Targeting macrophages might represent an attractive strategy to prevent MRONJ and improve therapy. In addition, our results support the hypothesis of an anti-tumoral and anti-metastatic effect induced by BPs. However, further studies are needed to delineate the mechanisms and specify the contributions of the various macrophage phenotypes

Expression of Msx-1 is suppressed in bisphosphonate associated osteonecrosis related jaw tissue-etiopathology considerations respecting jaw developmental biology-related unique features

<p>Abstract</p> <p>Background</p> <p>Bone-destructive disease treatments include bisphosphonates and antibodies against the osteoclast differentiator, RANKL (aRANKL); however, osteonecrosis of the jaw (ONJ) is a frequent side-effect. Current models fail to explain the restriction of bisphosphonate (BP)-related and denosumab (anti-RANKL antibody)-related ONJ to jaws. Msx-1 is exclusively expressed in craniofacial structures and pivotal to cranial neural crest (CNC)-derived periodontal tissue remodeling. We hypothesised that Msx-1 expression might be impaired in bisphosphonate-related ONJ. The study aim was to elucidate Msx-1 and RANKL-associated signal transduction (BMP-2/4, RANKL) in ONJ-altered and healthy periodontal tissue.</p> <p>Methods</p> <p>Twenty ONJ and twenty non-BP exposed periodontal samples were processed for RT-PCR and immunohistochemistry. An automated staining-based alkaline phosphatase-anti-alkaline phosphatase method was used to measure the stained cells:total cell-number ratio (labelling index, Bonferroni adjustment). Real-time RT-PCR was performed on ONJ-affected and healthy jaw periodontal samples (n = 20 each) to quantitatively compare Msx-1, BMP-2, RANKL, and GAPDH mRNA levels.</p> <p>Results</p> <p>Semi-quantitative assessment of the ratio of stained cells showed decreased Msx-1 and RANKL and increased BMP-2/4 (all p < 0.05) expression in ONJ-adjacent periodontal tissue. ONJ tissue also exhibited decreased relative gene expression for Msx-1 (p < 0.03) and RANKL (p < 0.03) and increased BMP-2/4 expression (p < 0.02) compared to control.</p> <p>Conclusions</p> <p>These results explain the sclerotic and osteopetrotic changes of periodontal tissue following BP application and substantiate clinical findings of BP-related impaired remodeling specific to periodontal tissue. RANKL suppression substantiated the clinical finding of impaired bone remodelling in BP- and aRANKL-induced ONJ-affected bone structures. Msx-1 suppression in ONJ-adjacent periodontal tissue suggested a bisphosphonate-related impairment in cellular differentiation that occurred exclusively jaw remodelling. Further research on developmental biology-related unique features of jaw bone structures will help to elucidate pathologies restricted to maxillofacial tissue.</p

Osteosarcoma of the jaw – experience at the Medical University Vienna and comparative study with international tumor registries

OBJECTIVES: Osteosarcoma of the jaw (OSAJ) is fundamentally different in clinical practice from its peripheral counterparts. Studies are difficult to conduct due to low incidence rates. The primary aim of this study was to provide for the first time a comprehensive retrospective analysis of the treatment concepts and outcome data of OSAJ patients treated at the University Hospital Vienna and to compare these with two recently published studies on OSAJ. The clinical study was accompanied by a biomarker study investigating the prognostic relevance of melanoma-associated antigen-A (MAGE-A) in OSAJ specimens. METHOD: Eighteen patients were included, and their outcomes were compared to published data. Immunohistochemistry was performed with mouse monoclonal antibodies against MAGE-A. Survival rates were estimated by the Kaplan-Meyer method. The log-rank test was used to analyze potential prognostic parameters. Fisher’s exact test was performed to define the significant differences between the survival rates of the current study and the DOESAK registry. RESULTS: Disease-specific survival was 93.8% after five and 56.3% after ten years. The development of metastases (p=0.033) or relapse (p=0.037) was associated with worsened outcomes in our group as well as in the comparative group. Despite the different treatment concepts of the study groups, survival rates were comparable. MAGE-A failed to show prognostic relevance for OSAJ patients. CONCLUSIONS: Uncertainties about the optimal treatment strategies of OSAJ patients will currently remain. Thus, prospective studies of OSAJ are needed but are only feasible in a multicenter study setting, conducted over a prolonged time period

Expression of MAGE-A12 in oral squamous cell carcinoma. Dis Markers 24(1

Abstract. Melanoma associated-A antigens (MAGE-A) are silent in normal tissues except testis. However, they are activated in a variety of different tumors. Thus, their expression is highly specific to cancer cells. Reverse transcription-nested polymerase chain reaction (RT-nPCR) is a highly sensitive technique that has been used successfully for the detection of MAGE genes in tissue samples. The aim of the study is to analyze the expression rate of MAGE-A12 in oral squamous cell carcinoma (OSCC) using a high sensitive RT-nPCR. Total of 57 tissue samples obtained from patients with OSCC and 20 normal oral mucosal (NOM) probes of otherwise healthy volunteers were included to this study. No expression of MAGE-A12 was observed in the non-neoplastic NOM tissues. MAGE-A12 was expressed in 49.1% of the investigated tumor samples. The correlation between malignant lesion and MAGE-A12 detection was significant (p &lt; 0.001). It is concluded that results of this study may indicate MAGE-A12 as a useful additional diagnostic marker especially for the early detection of OSCC distinguishing neoplastic transformation and detection of occult and/or rare disseminated cancer cells. In addition, MAGE-A12 expression in OSCC may also determine a new immunotherapeutic target and might be warranted to develop vaccine for OSCC

Single Disseminated Tumor Cell Detection in Peripheral Blood Sample of Patients with Oral Squamous Cell Carcinoma Using MAGE-A4

Background: Present study aimed to investigate the single disseminated. tumor cells (DTC) in whole peripheral blood samples collected from patients with oral squamous cell carcinoma (OSCC) for the early detection of metastatic cells and prognosis by expression analysis of Melanoma Associated Antigen-A4 (MAGE-A4). Methods: Eighteen patients with OSCC and 14 otherwise healthy volunteers were included in this study. The QuantiGene 2:0 RNA Quantification System was used as a reagent for RNA detection and quantification, and the results were evaluated by the luminescence reader. Results: There was no DTC detected by the expression analysis of MAGE-A4 in blood samples collected from patients with OSCC. Conclusions: Detection of single DTC in peripheral whole blood samples from OSCC patients may be an effective early detection method when the suggested steps were included in the method according to the authors’ present experience