Cancer and How It Develops Essay Example | Topics and Well Written Essays - 500 words

Cancer and How It Develops - Essay Example However a tumor on reaching a critical mass secretes chemicals to tempt blood vessels to invade the tumor to provide a channel for its nutrient supply and waste removal to support its uncontrolled growth. This also opens up a route for the cancer cells to metastasize or spread to other locations in the body through the blood and lymph vessels making surgical removal impossible. Chemotherapy or radiation is used to destroy metastasized cells. Cancerous cells defy the control mechanisms that are placed to regulate cell division. In a normal cell cycle proto oncogenes and tumor suppressor genes in combination with each other regulate cell division. Proto-oncogenes promote the division of cells through its effects on growth factors or by producing them where as products of tumor- suppressor genes act in damage control such as repair and programmed cell death. Mutations in these genes results in malfunctions in cell cycle and leads to uncontrolled cell division giving rise to cancerous cells. Mutation in the tumor-suppressor gene p53 is associated with more than half known cancers. A protein produced by gene p53 regulates another gene whose gene product keeps a check on cell division. A mutation in p53 lifts that check resulting in uncontrolled cell division. Mutations in a proto-oncogene turn it to an oncogene which produces larger amounts of proteins (which are mostly growth factors or its receptors) or enhances the activi ty of the protein resulting in hyper stimulation of cell-division. A distinguishing character of cancer cells is its lack of contact inhibition. They are devoid of anchorage unlike in normal cells that stop division on contact with neighboring cells through information from signaling systems. Failure to trigger the mechanism of programmed cell death or apoptosis also is a characteristic of cancerous cells. The genetic suicide program is activated in normal cells in response to a physiological or biological signal in

A New Model for Change Essay Example | Topics and Well Written Essays - 500 words

A New Model for Change - Essay Example These stages are saying goodbye which is having the commitment to leave how things used to be, shifting into neutral which is the middle ground between the old practice and the change which is desired to be executed, and moving forward which involves embarking in the set direction. Leaders should be aware of these stages, move from one stage to another by avoiding the tendency to be stuck. Understanding transition is one of the requisite for managers. For one, they are advised to bear in mind that their people need to be given some time in order to internalize the desired change. Also, managers should clearly identify the reasons why some of the employees are hesitant to embrace the transformation which is instituted. And lastly, they should realize that people are often held back not by the changes themselves but by the process of transition. The transition can be smoothly managed by the employment of a coach who oversees the process that the manager is going through to bring about the needed change. This is important because of a manager is less from being well-rounded and might be inclined in only in one functional area.