The chemopreventive polyphenol Curcumin prevents hematogenous breast cancer metastases in immunodeficient mice

Dissemination of metastatic cells probably occurs long before diagnosis of the primary tumor. Metastasis during early phases of carcinogenesis in high risk patients is therefore a potential prevention target. The plant polyphenol Curcumin has been proposed for dietary prevention of cancer. We therefore examined its effects on the human breast cancer cell line MDA-MB-231 in vitro and in a mouse metastasis model. Curcumin strongly induces apoptosis in MDA- MB- 231 cells in correlation with reduced activation of the survival pathway NF kappa B, as a consequence of diminished I kappa B and p65 phosphorylation. Curcumin also reduces the expression of major matrix metalloproteinases (MMPs) due to reduced NF kappa B activity and transcriptional downregulation of AP-1. NF kappa B/p65 silencing is sufficient to downregulate c-jun and MMP expression. Reduced NF kappa B/AP-1 activity and MMP expression lead to diminished invasion through a reconstituted basement membrane and to a significantly lower number of lung metastases in immunodeficient mice after intercardiac injection of 231 cells (p=0.0035). 68% of Curcumin treated but only 17% of untreated animals showed no or very few lung metastases, most likely as a consequence of down-regulation of NF kappa B/AP-1 dependent MMP expression and direct apoptotic effects on circulating tumor cells but not on established metastases. Dietary chemoprevention of metastases appears therefore feasible. Copyright (c) 2007 S. Karger AG, Basel

The Advancement of Biomaterials in Regulating Stem Cell Fate.

Stem cells are well-known to have prominent roles in tissue engineering applications. Embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) can differentiate into every cell type in the body while adult stem cells such as mesenchymal stem cells (MSCs) can be isolated from various sources. Nevertheless, an utmost limitation in harnessing stem cells for tissue engineering is the supply of cells. The advances in biomaterial technology allows the establishment of ex vivo expansion systems to overcome this bottleneck. The progress of various scaffold fabrication could direct stem cell fate decisions including cell proliferation and differentiation into specific lineages in vitro. Stem cell biology and biomaterial technology promote synergistic effect on stem cell-based regenerative therapies. Therefore, understanding the interaction of stem cell and biomaterials would allow the designation of new biomaterials for future clinical therapeutic applications for tissue regeneration. This review focuses mainly on the advances of natural and synthetic biomaterials in regulating stem cell fate decisions. We have also briefly discussed how biological and biophysical properties of biomaterials including wettability, chemical functionality, biodegradability and stiffness play their roles

FACILITATORS AND BARRIERS FOR BEDSIDE TEACHING IN THE TEACHING HOSPITALS OF COASTAL SOUTH INDIA

 Objectives: The aim was to assess and compare the perception of clinical faculty toward bedside teaching (BST) for undergraduate medical studentsand the barriers encountered by them.Methods: The present cross-sectional study was carried out among clinical faculty of three tertiary care hospitals attached to a medical collegein Mangalore. A total of 94 clinical faculties, excluding the post-graduates, were approached by using convenient sampling. A semi structuredquestionnaire was distributed to the participants of this study. The response to the perceptions and barriers of BST was captured using five-pointLikert scale.Results: The age of the study participants ranged from 27 to 60 years (mean age of 38±8.85 years). Most of the study participants strongly agreedthat BST is an essential part of clinical medicine, which improves communication skills, practical skills by providing trigger scenarios to stimulatelearning. They disagreed toward classroom teaching being equal to BST in imparting knowledge and students being capable of acquiring knowledgefrom clinical books without BST. There was a significant difference in perception score of barriers toward BST among medical and surgical faculty inrelation to bigger group size and increase the workload being deterring factors for effective BST.Conclusion: BST is still valued by the clinical fraternity as an efficient teaching tool for the medical students even in this era of simulation basedtraining.Keywords: Bedside teaching, Facilitators, Barrier, Clinical faculty