Drug Dose and Its Concentration at Receptors Essay - 1

Drug Dose and Its Concentration at Receptors - Essay Example These factors are discussed in more detail below, based on the description of Goodman, et al. (2011, ch. 2). The characteristics of the drug molecule itself that affect the drug’s concentration at the receptor site include its molecular size, degree of ionization, lipid solubility, and its affinity for serum and tissue proteins. The plasma membrane (of skin or intestinal cells, for example) is a common barrier to drug distribution; drugs that are not lipid soluble will not be able to permeate the membrane and not reach the target site. A drug of small molecular size will travel more easily through the membranes than a larger molecule, reaching the target in higher concentrations. Ionized molecules, and those that bind to proteins, also have difficulties in passing through the membrane. If the drug has a tendency to ionize at the pH of the intestinal lumen or the blood, the ionized form will have difficulty passing through lipid plasma membranes. If the drug interacts with tran sporter proteins on the cell membrane, its uptake into the cell may be increased or decreased, depending on the direction in which the transporter moves the drug. For example, the P-glycoprotein in enterocytes limits the oral absorption of some cancer chemotherapeutic agents by exporting them back into the lumen of the GI tract. Similarly, it has been found that multidrug transporters such as P-glycoprotein (PGP) and members of the multidrug resistance-associated protein (MRP) family are over-expressed in capillary endothelial cells in epileptogenic brain tissue, and, by transporting anti-epileptic drugs out, these proteins may be responsible for the pharmacoresistance of the epileptic brain to anti-epileptic drugs (LÃ ¶scher and Potschka, 2002).

Rewrite - Extended Research Report Essay Example | Topics and Well Written Essays - 1000 words

Rewrite - Extended Research Report - Essay Example It is vital to know the skills of employees as to understand the goals that they should take on. Research findings have shown that employee performance evaluations also depend on the development and organizational improvement of the company. By conducting this evaluation, employees can be instructed on how to provide better work. The evaluation can also help to provide the employee with personal development and organizational goals. The possibilities of an increase in salary, a promotion, and good recognition can also result from employee evaluations. This report concludes that not only do employee performance evaluations help to improve employee work, but can also aid a company in improving its business. Goals, whether long-term or short-term, cannot be met without regular evaluations. Recommendations discussed within the report include: increased productivity, making retainable and realistic goals, improving business relations, and helping various industries to narrow down on areas within their business that need improvement. This final paper is based on the extended research report that I have been conducting, providing an up-to-date status on employee performance evaluations based on the subject of human resources in the field of business. To completely understand the challenges that people face with human resource issues, I have opted to research and address the importance of the employee performance evaluation. I began researching this topic on June 10, 2010, and have been steadily adding on to it until it was completed. Employee performance evaluation has been an interesting topic to research and write about. When employers undergo performance evaluations for their employees, they are providing their workers with either praise or criticism, letting them know of the good they are doing and if anything needs to be changed.