Dr. Dave Science

The Flu Virus is a Terrorist?

drdavescience — Tue, 29 Dec 2009 18:44:53 +0000

In a recent PBS documentary about the 1918 flu pandemic, a virology expert described the flu virus as "a little terrorist."

I must say the description is spot-on.

Think about it: a flu virus works by invading cells that line the airways and literally hijacks cellular machinery to make copies of itself. When it expends the cell's resources, it effectively kills the host cell and the newly created viruses that are free to infect neighboring cells where the process continues.

It seems the flu and extreme religious ideology have something in common. Well, at least metaphorically.

Happy New Year!

Dr. Dave

Posted via email from Dr. Dave Science

Kills flu virus…nope

drdavescience — Mon, 14 Dec 2009 19:07:22 +0000

My coworker has a box of Lysol disinfecting wipes on her desk and I felt compelled to take a picture of the label. Why? The bright yellow label at the top says "Kills Flu Virus."

So what?

For starters, the flu virus–any virus, for that matter–is not alive. Viruses lack the basic machinery that makes life possible from bacteria to humans and everything in between. In general, viruses cannot replicate DNA, assemble proteins and sugars, or generate energy. Instead a virus must rely on a target cell to do all the work. (We can delve further, but I'll stop here.)

So, with the above in mind, how can you kill something that's not alive? The word "destroy" seems more appropriate, don't you think?

Semantics aside, very few people would actually notice (or care) that a virus can not be be killed. Focus on the big-picture: a simple non-living virus can cause tremendous harm to humans. Now that is something to notice.

-Dr. Dave

Posted via email from Dr. Dave Science

Science in the news: The uproar over recent breast cancer screening recommendations

drdavescience — Sun, 29 Nov 2009 18:33:41 +0000

The outcry over the new recommendations for breast cancer screening seems to have subsided this week. As a recap, an expert panel advocates mammography for women 49 years or younger after consultation with their doctor; women 50 years and older should be screened every 2 years.

Why the change?

A panel of cancer experts evaluated medical data from women with breast cancer, looking specifically at factors such as age, treatment history and outcomes. After analyzing the data, the researchers observed both benefits and harms of early screening in women 49 years or younger.

Wait, harms of early detection? Really?

The harms the expert panel mentions are false-positive results, unnecessary biopsies, and over-diagnosis. The frequency of these events were greater in women 49 years and younger, and may outweigh the benefits of early screening in many women.

Diana Petitti, the Vice Chair of the expert panel had this to say:

"So, what does this mean if you are a woman in your 40s? You should talk to your doctor and make an informed decision about whether a mammography is right for you based on your family history, general health, and personal values."

Well said.

Dr. Dave

Posted via email from Dr. Dave Science

How big is a skin cell or carbon atom?

drdavescience — Sun, 01 Nov 2009 18:36:35 +0000

For those who have wondered, or if you’re just plain curious, click on the link below and use the slider:

http://learn.genetics.utah.edu/content/begin/cells/scale

Very well done!

Dr. Dave

Posted via email from Dr. Dave Science

NASA Ares X-1 Success!

drdavescience — Wed, 28 Oct 2009 16:09:09 +0000

The test launch was a success! Way to go NASA!

Watch the test launch below:

NASA Test Launch of Ares

drdavescience — Wed, 28 Oct 2009 15:00:38 +0000

Check out NASA TV to see the test launch of the new Ares rocket. How exciting!

Mission Control is waiting on weather; I hope it cooperates!

Dr. Dave

Posted via email from Dr. Dave Science

Flu from the Flu Shot? Not! Part 1

drdavescience — Fri, 23 Oct 2009 03:08:44 +0000

A few weeks ago I received my annual flu shot. Although I had heard stories about people describing "flu-like" symptoms after vaccination, I had never experienced a problem over the past 10 years. This year was different.

Within hours of the injection my arm was sore; by the end of the day I felt achy, tired and I had a low grade fever. I would say that my symptoms were "flu-like," but if you think about it, many illness that are not the flu often start off with "flu-like" symptoms.

According to the scientific data contained in the vaccine's prescribing information, the symptoms I described are common (read the section on adverse events).

But is it the Flu?

According to the CDC, it takes an average of 2 days from exposure to the flu virus before showing signs of illness. Since the side effects occurred within a few hours of vaccination, it must be something else.

What is it? Stay tuned…

Dr. Dave

Posted via email from Dr. Dave Science

My Laptop is Alive!

drdavescience — Fri, 23 Oct 2009 00:20:27 +0000

Hello!

My laptop has been given a new lease on life thanks to the kind and knowledgeable folks atwww.powerbookmedic.com. Thank you!

I'm testing a few applications right now and thinking about everyday science concerns. Posts to come soon!

Dr. Dave

Posted via email from Dr. Dave Science

Computer Failure

drdavescience — Fri, 16 Oct 2009 16:43:17 +0000

My beloved laptop of the past 6 years suffered a catastrophic hard drive failure. Since the other components work great, I’m having the hard drive replaced. (It’s the less expensive options, and in this economy, it’s a wise choice.)

Once I get it up and running, I hope to post more frequently. In the meantime, I’ve been writing my ideas down in a notebook.

Thanks for your patience!

Dr. Dave

Malaria originated in chimps!

drdavescience — Wed, 05 Aug 2009 18:17:48 +0000

I came across this article about the origins of malaria in CNN. I have had malaria twice in my life, so stories about this disease always draw my attention.

It should come as no surprise that the chimpanzee is the origin of malaria in man; after all, chimps are our closest genetic relative in the animal kingdom. Before you go blaming the apes for malaria, keep in mind that the spread of disease is not a one-way street; it is very likely that man has also spread disease to apes.

What is malaria?

Malaria is disease that is caused by a parasite and is spread by mosquitoes. Malaria causes fevers, severe headaches, and chills, and if left untreated, it can lead to brain damage and even death.

A brief history of malaria

Mankind has been plagued by malaria for thousands of years. Long ago, silly theories on the origin of diseases were commonplace. People believed that malaria was caused by something foul in the air, which is where the disease got it’s name. (“Mal” means bad and “aria” means air.)

For many centuries, there was no treatment for malaria until the 1600s when an observant Jesuit priest living in ancient Peru noticed local tribesmen using ground bark from cinchona trees to treat the telltale fever and shivering associated with the disease. The bark was soon sent to Rome, where malaria was rampant, and the results were amazing.

In the early 1800s, scientists determine isolated quinine, the ingredient responsible for the anti-malarial effect of the cinchona bark. Many historians believe that quinine played an important role in the colonization of Africa and during World War II.

Where?

Mosquitoes tend to thrive in warm and humid environments, so it’s no surprise that the majority of people affected by the malaria live in countries with a tropical climate. Check out the malaria distribution map from the CDC website:

According to the CDC, 500 million people suffer from malaria and 1 to 3 million people die each year.

Today, very few cases of malaria are reported in the US, but this was not the case 50 years ago when it was the scourge of the south. In fact, malaria was such a significant health problem that it influenced the then newly-formed Centers for Disease Control (CDC) to select Atlanta as its headquarters.

My personal experience

I was 10 years old and traveling in India when I first caught malaria. Usually, travelers in high-risk regions take anti-malaria pills to prevent the disease, but I had to stop due to serious side-effects.

As my friends and family know, I am a mosquito magnet. Frankly, I am not surprised that I caught malaria.

As soon as I fell ill the local doctor immediately recognized the signs of malaria and was able to treat me right away. I was sick for about 1 week, with the worst symptoms lasting only two days. I was lucky because treatment was readily available. People in poor countries do not have rapid access to health care and tend to suffer for long periods of time.

Malaria: Take two

About one year later, I had malaria again; however, this time I was at home in the San Francisco Bay Area, which has a mild climate and very few mosquitoes. How did I catch malaria in the Bay Area? The answer is, I didn’t.

As it turns out, the parasite that causes malaria can live inside liver cells without causing any harm. For some unknown reason, the parasite exits the liver cell and becomes active to cause disease again. This is what happened to me.

My second experience with malaria was considerably worse because my primary care doctor had never seen a patient with the disease. For two weeks I suffered from raging headaches, high fevers and chills. I was rapidly losing weight and I even slipped in and out of consciousness a few times.

My parents were terrified. Eventually I was referred to an infectious disease specialist who recognized the signs of malaria and treated me right away. Given my extreme symptoms, the specialist told my parents that I was lucky to be alive.

Although I did not understand it at the time, I realize that my primary care doctor would never have thought of malaria given the rarity of the disease in America. I can’t blame him, but I hope that he learned from my illness.

Epilogue

My experiences with malaria changed my life. Because of the illness, I decided to major in immunology at U.C. Berkeley and worked in an infectious diseases laboratory for a few years.

Ultimately, the most lasting lesson of my bouts with malaria is that life is very precious. I had come close to losing it, but I was spared. Knowing firsthand what it is like to suffer from malaria, I can only hope that medical science can create a vaccine that can halt the disease in its tracks.

For more information about malaria, please click here for the CDC’s Malaria page.

If you would like to read more about the philanthropic efforts of the Bill and Melinda Gates Foundation to combat malaria worldwide, please click here.

-Dr. Dave