Viagra as a Therapy for Heart Failure

Viagra as a Therapy for heart Failure: Effectiveness on Male vs Female

David Chen
17 May 2014

John Hopkins University School of Medicine
Published: 16 May 2014
http://medicalxpress.com/news/2014-05-gender-differences-impact-viagra-therapy.html


Summary:
          When we think of Viagra, we don't think of a treatment for heart failure. We think of those awkward advertisements... Or what the drug was made for, erectile dysfunction. However, within the last decade, scientists have realized another use for Viagra. Sildenafil, the active ingredient in Viagra, can help with heart problems. Sildenafil, when taken, can activate an enzyme that causes a protein called "titin" to relax. This protein is responsible for the elasticity of a cell, and in muscle tissue, it can often cause stiffening. In Viagra's normal application, it dilates the blood vessels, leading to increased blood flow to the penis. However, with further testing, Takimoto, an assistant professor of medicine and a researcher at the Heart and Vascular Institute at John Hopkins, and his team discovered something peculiar between male and female mice models. All of the mice recieved cardiac remodeling. The effectiveness of Sildenafil on females were different from the males. Upon further research, scientists discovered that the hormone estrogen played a role in interacting with Sildenafil. As of now, it appears to help in repairing the heart muscle. Takimoto says this could be an explanation for why a Sildenafil based drug: "RELAX", does not work effectively, as most of its female participants were 70 or older, when menopause had already struck, and estrogen was lower.

Connection:
          This article has several connections to what we are learning in biology. Firstly, the main way Sildenafil works is by activating an enzyme, which interacts with a protein. This connects with our unit where we learned about enzymes and proteins. Also, titin connects with how muscles work, as it adds on to our knowledge about how the basic units of muscles, sarcomeres, work. Second, this connects with the circulatory system, in our current unit about the human body. Specifically, it connects with heart failure, which is a condition brought on by many of the diseases explored by the Circulatory Presentation group (I'm in it). Third, the hormone estrogen will connect with a later unit that we will go over, in which we explore the hormones of the body.

Mutant enzymes help break cocaine habit

Sarah Jackman
Royal Society of Chemistry
Author: Jason Woolford
Published: September 30, 2013
http://www.rsc.org/chemistryworld/2013/09/cocaine-addiction-enzyme-treatment-butyrylcholinesterase

Summary:
     A new discovery from the University of Kentucky have found a possible treatment for cocaine addiction. Currently, there are no medications that have been officially proven to do so. Chang-guo Zhan, a worker at the University of Kentucky, found that the enzyme (butyrylcholinesterase) that changes the route of cocaine in the body and turns the harmful substance into harmless products. Through experiments, mutations of butyrylcholinesterase (BChE) were produced that effectively decomposed cocaine. The mutated enzyme was able to break down cocaine 1000 times faster than the original enzyme. This discovery is "very promising" and one mutant version on BChE is being tested in human trials. 

Connection :
     In this term, we spent a while discussing enzymes and did a lab using catalase. The article connects to what we have learned about enzymes such as that they can break substrates down into products(decomposition). For example, in the enzyme lab we took a harmful substance to the body(hydrogen peroxide), and added the enzyme catalase to make a harmless product. The article describes something similar. Butyrylcholinesterase transforms the harmful substance, cocaine, into products that are safe for the body. 

Bee Venom Destroys HIV And Spares Surrounding Cells

Scientists are coming close to creating a gel which could potentially stop the spread of the hiv virus. Melittin a toxin inside Bee Venom is found to poke holes in the casing around HIV. In large enough quantities it could destroy the virus. Also Venom has been shown to possibly be linked with  anti-cancer treatment.The difference between this new Melittin Nano-particle and normal hiv medications is that this strips the hiv of a vital cell structure and normal medications focus on stopping the replication. This could theoretically also work on other viruses such as hepatitis a and b. It also could be used to theoretically clear already existing hiv out of the blood stream, even anti-drug resistant ones.

Connection: In the microbe unit we studied retroviruses such as HIV. Also Bees are animals, we also discussed ways to stop the spread of such viruses.