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A Self-Destructive Mosquito Bite January 18, 2008

Posted by Mrs Weird Scientist in Animals, Diseases, Human Body, Insects, Think About It.
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Mosquito 2

A mosquito’s bite usually has a characteristic sting, but the pain subsides and at worst, most of us experience a bit of swelling, itching and redness for a few days. For some people, however, a mosquito’s bite can bring with it some lasting discomfort – namely when the mosquito is carrying a disease such as malaria, yellow fever or West Nile virus – among others. The good news is that researchers from the University of Arizona in Tucson may soon have a way to make the mosquito’s bite deadly to itself!

Figuring It Out

Mosquito Researchers recently discovered something very peculiar. When a mosquito species known as Aedes aegypti gorges on human blood, it excretes a substance called nitrogen immediately afterwards. The nitrogen is toxic to the mosquitoes and must be released following its meal. What happens if the mosquito doesn’t excrete the nitrogen? Bam! Self-destruction! If the mosquitoes don’t excrete the nitrogen, they will not lay eggs and will most likely become ill and die.

Taking Advantage Of Nature

By taking into account this complicated metabolic pathway of the mosquito, researchers are now looking for a molecule that won’t harm humans but will basically muck up the metabolic pathways of mosquitoes, which means they’ll retain their nitrogen and effectively self-destruct. Once the researchers have figured out the mechanics of the molecule, they can then develop an insecticide and spray it in the areas where mosquitoes like to play – around the water, for example.

According to the lead researcher Roger Miesfeld:

Our goal is to turn the female mosquito’s blood meal into the last meal she ever eats. The whole community would essentially become one big mosquito trap. It would be a group effort that in the long run could have a huge impact. This would be one more weapon in our arsenal against diseases that kill millions of people a year.

Another potential application would be an oral insecticide. So, if you lived in an area where a disease such as malaria is prevalent, you could take a pill that would cause the mosquito to ingest the insecticide along with your blood. This wouldn’t prevent you from actually getting the disease but it would kill the mosquito after it bites, which means the spread of disease could be slowed.

I find it easy to forget just how potentially dangerous a mosquito’s bite can be, mostly because I am either living in North America or the United Kingdom, where the risk of disease from mosquitoes is fairly small. Yet, for many people, diseases passed through mosquitoes are a frightening reality. Hopefully, this new research can help to reduce the mosquito population and prevent both the initial sting and the spread of diseases.

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Antibacterial Protection Right Under Your Feet November 8, 2007

Posted by Mrs Weird Scientist in Diseases, Environment, Human Body, Tough Stuff.
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Clay – it’s that dirty looking, messy and just plain ol’ gunky stuff we find on the ground. But researchers have just recently found out that it also has some neat antibacterial properties too! A unique type of French clay has been found to terminate all sorts of bacteria, even antibiotic resistant ones that have become a very real and frightening challenge to combat. On top of that, the clay has been found to beat an icky pathogen – Mycobacterium ulcerans – that can cause skin ulcers in several parts of the world, leading to amputations.

Investigating Clay

This particular clay isn’t something new. In fact, it has been around for centuries where it was thought to have medicinal value, being used for skin cleansing and treating the bacteria that cause the icky ulcers I just mentioned. It was when geochemist Lynda Williams of Arizona State University learned of the clay’s power against Mycobacterium ulcerans that she gathered up a crew of curious researchers who were all eager to study the properties of the clay.

Clay The researchers dubbed the clay CsAg02. What a complex name! I sometimes give a little sigh and wonder why they can’t give the clay a less technical name – like Super Germ Buster Magnifique (that last bit was my ode to the French nature of the clay!). They learned that it’s a strong alkaline and has a pH of 9.4 to 10. Its cool greenish color is from a chemical form of iron. Still, lots of other clays have these same properties, so it’s clearly some other aspect of the clay that’s responsible for its potent antibacterial properties. Hmmmmmm.


To figure out just how the clay blasts away bacteria, Williams and her team treated the clay with potassium salt, which pulls out charged molecules. Without these charged molecules, the antibacterial power of the clay was blocked! So, this means that the bacteria are somehow affected by the charged molecules. Now, the next step for the research team will be to study what minerals keep these molecules active and rearing to fight against the bacteria.

Bacteria Beware

Researchers also wanted to check out what effect CsAg02 had on different microbes. How did they do that? Well, they took cultures of microbes and incubated them with CsAg02. You might have heard names of bacteria that are commonly implicated in cases of food poisoning – Salmonella typhimurium and Escherichia coli. We can give a big kudos to CsAg02 because it knocked them both out by stopping their growth! Researchers also incubated CsAg02 with strains of mycobacterium that can lead to skin infections. How well did it handle those? It stopped their growth as well!

So the clay kills bacteria – big deal, right? Actually, it is a really big deal! By figuring out just how the clay fights these powerful types of bacteria, we can learn new ways of killing some of the bacteria that plague humans. The clay could also provide antibacterial protection in air filters and sewage treatments. So, as sludgy and benign as clay may look, it still packs a powerful antimicrobial punch!

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Checking Out Kids’ Blood Pressure August 21, 2007

Posted by Mrs Weird Scientist in Diseases, Human Body, Nutrition and Health, Obesity, Think About It.
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When most of us think about high blood pressure – hypertension – we think of it as being a problem found in adults. Not so! Hypertension is also a problem for youth and it’s mostly related to the growing number of kids and teens who are obese.

Tell Me More

Blood Pressure Home Kit Your blood pressure is the pressure exerted by your blood against vessel walls as your heart pumps. When your heart contracts, it moves blood into vessels – increasing pressure – and when your heart relaxes, blood pressure lowers. Your blood pressure also fluctuates from minute to minute. It’s affected by lots of stuff such as exercise, rest, diet, and posture.

Undiagnosed Hypertension

A study performed by Dr. Matthew Hansen and other researchers at Case Western Reserve University in Cleveland looked at over 14,000 young people aged 3 to 18. The results, which were published in the Journal of the American Medical Association, showed a total of 507 cases of hypertension. One really worrying feature of the study was that 376 of those 507 cases were previously undiagnosed, even though patients had received at least three medical check-ups.

Dangers Of Hypertension

High Blood Pressure One of the scary things about high blood pressure is that it often goes undiagnosed, especially in youth. When blood pressure is high, the heart and arteries have a much heavier workload. All of this extra pumping by the heart as well as the strain on the arteries can be exhausting! Over time, the heart and arteries won’t work as well as they should, which can lead to organ damage – particularly the kidneys. There often aren’t any noticeable symptoms of hypertension, which can also make it tough to diagnose in the first place.

Better Diagnosis

Researchers suggested that changes needed to be made to electronic medical recording, so that doctors could identify the patients who were most at risk. This means doctors can perform regular check-ups and monitoring. If a patient is found to have hypertension, treatment can start right away to prevent problems down the road.

Good News

Is there really good news? Yep, there sure is! Despite the severe effects that can occur from untreated hypertension, those who do obtain early treatment can usually lead full and active lives. Also good news is that a healthy lifestyle can help to prevent future complications associated with hypertension. Lifestyle changes like adding in more fruits and vegetables, lowering salt intake and exercising regularly can really make a difference. In fact, these sorts of beneficial lifestyle choices can also work well in kids and teens who don’t have hypertension. By taking care of yourself, you can help to prevent ever getting hypertension. It’s not too early to start now!

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HIV Does More Than Mess With Your Immune System August 19, 2007

Posted by Mrs Weird Scientist in Diseases, Human Body, Stem Cells, Think About It.
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Laboratory 2You’ve probably already heard of the human immunodeficiency virus, also referred to as HIV. It’s a disease that is transmitted through bodily fluids such as blood, semen and vaginal fluid. HIV infects cells in your immune system and can lead to acquired immunodeficiency syndrome (AIDS). There is no cure and immune system failure occurs from secondary infections – things as seemingly minor as a common cold – because the body simply doesn’t have the tools to fight the infection.

HIV And Dementia

We’ve known for decades now that HIV damages a person’s immune system and we’ve even known that it can cause a certain type of dementia. A decline in a person’s cognitive functioning – beyond the normal decline that occurs with aging – is what constitutes dementia. Researchers knew that an HIV protein called gp120 was causing the loss of mature brain cells.

Gp120 Causes More Problems

A new study, however, is showing that gp120 causes even more damage. The work is being led by Stuart Lipton of the Burnham Institute for Medical Research in San Diego, California. Not only does it destroy mature brain cells, but it also slows down the division of neural progenitor cells. What are those? These are a type of adult stem cell. If you’re not familiar with adult stem cells or you’ve forgotten my recent stem cell primer, you can read about what stem cells are and where they come from. These neural progenitor cells are believed to be very important in learning and memory, so by slowing them down, gp120 can really wreck havoc with a person’s mental functioning. To check this out, researchers exposed the neural progenitor cells in rats to the gp120 protein. What happened? It’s not good. The result was that 15 percent of the neural progenitor cells stopped dividing.

Laboratory Finding Out About This Stuff Is Important

By finding out which parts of the body – such as the brain – the gp120 protein influences, scientists can then try to identify the enzymes that are affected. Under laboratory conditions, Lipton and his colleagues were able to stop the action of the enzymes, so the gp120 protein would not work! This means that the neural progenitor cells can hopefully get a kick-start to divide again. The study and results were published in Cell Stem Cell.

Prevent And Treat

With HIV and AIDS threatening the health and lives of enormous numbers of people around the world, preventing transmission of HIV is vital. Also important are studies such as this one, which helps us learn about how HIV can affect other systems in the human body, so we can find new treatments. It’s definitely not the cure that we all dream of finding, but it is an important step in fighting the disease.

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A Hazardous World July 29, 2007

Posted by Mrs Weird Scientist in Diseases, Easy As Pie, Environment, Human Body, Nutrition and Health.
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Unsanitary Drinking Water

At a recent news briefing, Jenny Pronczuk from the World Health Organization (WHO) explained how 4 million children die each year from environmental hazards. Sound scary? It gets worse. That’s 4 million children under the age of five. These environmental hazards include unsanitary drinking water, air pollution and exposure to chemicals. The region where most diseases from environmental hazards occur is Africa, followed by areas of south east Asia.

Hazardous Waste Site Sickness

These environmental hazards lead to all sorts of diseases and illnesses. Diarrhea and respiratory infections are common reactions to environmental hazards. Exposure to environmental hazards can also show up later, which means it’s not always an acute reaction. So, a child can be exposed to lead but the effects may not show up until the teen years, or even later. During the briefing, Pronczuk explained:

For example, if you look at lead exposure, the effect will be different if the child was exposed in utero (in the womb) because the lead of the mother goes into the bones of the child.

More Reading

It’s shocking to actually see the number in print: 4 million. The effects of environmental hazards on a child’s development and health are equally shocking. One organization that looks at children and their health is the International Pediatric Association (IPA). By aiming for education, prevention and treatment in areas such as environmental hazards, they are focused on children all around the world. The Children’s Environmental Health Network (CEHN), based in the United States, does a lot of research and education on environmental hazards and also looks at ways to safeguard kids’ health. Most of their work is focused in the United States. The Canadian Institute of Child Health (CICH) focuses on all areas of child health, which includes exposure to environmental hazards; their research is international.


Air Pollution The National Safety Council has some cool word scrambles and crosswords to challenge your knowledge of environmental hazards. Give them a try and see how much you know!

Air Quality

Lead Poisoning

Water Quality

Poison Prevention


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