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Simple Summary: Glioblastomas are very malignant and essentially incurable brain tumors. One problem is the extensive penetration of tumor cells into the adjacent normal brain tissue. Thus, the testing of novel drugs requires appropriate tumor models, preferentially avoiding animal studies. This paper describes so-called brain tissue slice tandem-culture systems. They consist of a slice of normal brain tissue and a second layer of tumor tissue. The microscopic analysis of these slice tandem-cultures allows for the simultaneous assessment of single cells invading into the normal brain tissue and the space occupying growth of the total tumor mass. It is shown that the direct application of test drugs onto the slices exerts inhibitory effects on both mechanisms. We thus describe a system mimicking the situation in glioblastoma patients. It reduces animal studies, allows for the direct application of test drugs and the precise quantitation of their inhibitory effects on tumor growth and invasion.
Abstract: Glioblastomas (GBMs) are the most malignant brain tumors and are essentially incurable even after extensive surgery, radiotherapy, and chemotherapy, mainly because of extensive infiltration of tumor cells into the adjacent normal tissue. Thus, the evaluation of novel drugs in malignant glioma treatment requires sophisticated ex vivo models that approach the authentic interplay between tumor and host environment while avoiding extensive in vivo studies in animals. This paper describes the standardized setup of an organotypic brain tissue slice tandem-culture system, comprising of normal brain tissue from adult mice and tumor tissue from human glioblastoma xenografts, and explore its utility for assessing inhibitory effects of test drugs. The microscopic analysis of vertical sections of the slice tandem-cultures allows for the simultaneous assessment of (i) the invasive potential of single cells or cell aggregates and (ii) the space occupying growth of the bulk tumor mass, both contributing to malignant tumor progression. The comparison of tissue slice co-cultures with spheroids vs. tissue slice tandem-cultures using tumor xenograft slices demonstrates advantages of the xenograft tandem approach. The direct and facile application of test drugs is shown to exert inhibitory effects on bulk tumor growth and/or tumor cell invasion, and allows their precise quantitation. In conclusion, we describe a straightforward ex vivo system mimicking the in vivo situation of the tumor mass and the normal brain in GBM patients. It reduces animal studies and allows for the direct and reproducible application of test drugs and the precise quantitation of their effects on the bulk tumor mass and on the tumor’s invasive properties
Endothelial cells play a critical role in the adaptation of tissues to injury. Tissue ischemia induced by infarction leads to profound changes in endothelial cell functions and can induce transition to a mesenchymal state. Here we explore the kinetics and individual cellular responses of endothelial cells after myocardial infarction by using single cell RNA sequencing. This study demonstrates a time dependent switch in endothelial cell proliferation and inflammation associated with transient changes in metabolic gene signatures. Trajectory analysis reveals that the majority of endothelial cells 3 to 7 days after myocardial infarction acquire a transient state, characterized by mesenchymal gene expression, which returns to baseline 14 days after injury. Lineage tracing, using the Cdh5-CreERT2;mT/mG mice followed by single cell RNA sequencing, confirms the transient mesenchymal transition and reveals additional hypoxic and inflammatory signatures of endothelial cells during early and late states after injury. These data suggest that endothelial cells undergo a transient mes-enchymal activation concomitant with a metabolic adaptation within the first days after myocardial infarction but do not acquire a long-term mesenchymal fate. This mesenchymal activation may facilitate endothelial cell migration and clonal expansion to regenerate the vascular network.
Background Multimorbidity is a highly frequent condition in older people, but well designed longitudinal studies on the impact of multimorbidity on patients and the health care system have been remarkably scarce in numbers until today. Little is known about the long term impact of multimorbidity on the patients' life expectancy, functional status and quality of life as well as health care utilization over time. As a consequence, there is little help for GPs in adjusting care for these patients, even though studies suggest that adhering to present clinical practice guidelines in the care of patients with multimorbidity may have adverse effects. Methods The study is designed as a multicentre prospective, observational cohort study of 3.050 patients aged 65 to 85 at baseline with at least three different diagnoses out of a list of 29 illnesses and syndromes. The patients will be recruited in approx. 120 to 150 GP surgeries in 8 study centres distributed across Germany. Information about the patients' morbidity will be collected mainly in GP interviews and from chart reviews. Functional status, resources/risk factors, health care utilization and additional morbidity data will be assessed in patient interviews, in which a multitude of well established standardized questionnaires and tests will be performed. Discussion The main aim of the cohort study is to monitor the course of the illness process and to analyse for which reasons medical conditions are stable, deteriorating or only temporarily present. First, clusters of combinations of diseases/disorders (multimorbidity patterns) with a comparable impact (e.g. on quality of life and/or functional status) will be identified. Then the development of these clusters over time will be analysed, especially with regard to prognostic variables and the somatic, psychological and social consequences as well as the utilization of health care resources. The results will allow the development of an instrument for prediction of the deterioration of the illness process and point at possibilities of prevention. The practical consequences of the study results for primary care will be analysed in expert focus groups in order to develop strategies for the inclusion of the aspects of multimorbidity in primary care guidelines.