From Isolated Tumour Cells to Overt Lymph Node Metastases: Biological and Imaging Studies on the Development of Experimental Lymph Node Metastases

Metastatic colonization and establishment of overt lymph node (LN) tumours indicates poor prognosis for cancer patients. However, the basic biology that influences the development of LN metastasis is poorly understood due to the lack of basic animal models. The following work provides a new lymph node experimental metastasis assay (LEMA) that permits the assessment of tumour cell fate after they arrest in draining LNs. In using this new model, we discovered that only 8% of the tumour cells that arrive in the LN are successful in forming overt tumours. This work also explored the use of imaging approaches to monitor the process on LN metastasis in mice. To study the in vivo growth of LN metastases, we used 3-dimensional high frequency ultrasound (HFUS). We observed that growth rates of LN tumours varied from mouse to mouse. Furthermore, HFUS allowed us to visualize small metastatic deposits and micrometastases and their growth over time. In order to provide some ground work for the development of magnetic resonance imaging (MRI) of lymph node metastases, we developed a gel phantom that simulated the metastatic colonization of LNs. By labeling cells with gadofluorine M (GdF, a positive contrast agent), we were able to demonstrate how MRI (3 Tesla) was able to quantitatively measure the abundance of GdF-labeled tumour cells. The research described herein will expedite future research by providing a new experimental lymph node metastasis assay and novel imaging techniques that will permit the study of metastasis development in the lymph node

Probiotic growth in skin-like conditions

Although probiotics’ main known effects are in the digestive system, over the last years several benefits that come from their topical use, have been investigated. Several studies have reported beneficial effects on different skin disorders, such as atopic dermatitis, acne, eczema, psoriasis, wound healing, skin aging and reactive skin. Their main action is assigned to the inhibition of skin colonization by pathogens. In this work, the growths of three probiotic strains were evaluated in the presence of abiotic factors similar to those found in skin, namely, UV radiation, temperature, pH, NaCl and fatty acids. Lactobacillus rhamnosus showed increased growth under the pH of 6, but no differences in its growth were found for the various NaCl concentrations tested. Lactobacillus delbrueckii increased the number of bacterial cells in 88.8% when grown in 10 mM NaCl concentration, while Propioniferax innocua showed increased growth at 45 ℃. All tested probiotic bacteria were able to grow under skin-like conditions. However, L. rhamnosus was the probiotic that showed the best results. The results obtained in this study indicate that the used probiotics may be beneficial in the treatment of skin diseases, since they are able to successfully thrive in skin-like conditions.info:eu-repo/semantics/publishedVersio