Category Archives: Health Care

How do antibiotics kill bacteria?

How do antibiotics kill bacterial cells but not human cells? (pointy haired bosses (phb) at Scientific American broke the link so I removed it – see links in comments below that are not broken by phb behavior)

Most bacteria produce a cell wall that is composed partly of a macromolecule called peptidoglycan, itself made up of amino sugars and short peptides. Human cells do not make or need peptidoglycan. Penicillin, one of the first antibiotics to be used widely, prevents the final cross-linking step, or transpeptidation, in assembly of this macromolecule. The result is a very fragile cell wall that bursts, killing the bacterium.

Read more blog posts on antibiotics and on health care.

Reducing Risk of Diabetes Through Exercise

A Diabetic Battle of the Bulge by Diane Garcia

Diabetes appears to be written into some people’s genes, but with the right diet and exercise, the disease may never surface, according to a new study.
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In the lifestyle modification group, however, even individuals with two copies of the variant were no more likely to develop type 2 diabetes than participants without the variant, the team reports 20 July in the New England Journal of Medicine

Update – AAAS broke the link so I removed the link. I hope those responsible for web sites eventually take the time to learn what that responsibility entails: Web Pages Must Live Forever. I find these failures to follow the most basic web usability practices displayed most often in organizations where burocrates that don’t understand technology make decisions on how web sites should work instead of allowing those that have the necessary understanding of the technology do so.

Food Health Policy Blog

Rudd Sound Bites is a new blog (May 2006) on obesity research from the Rudd Center for Food Policy and Obesity.

This is a great example of pursuing a role to educate the public and create a public discussion of important issues. From what I see so far I think this will be a great way to do what they entend: “encourage global discussion of front burner news and the most critical issues regarding food policy and obesity.”

This is just the begining. They have not achieved much yet, that I can see. But they are on a path that will get them what they seek, I believe.

Good job.

Tour the Carnegie Mellon Robotics Lab

Robert Scoble videotaped his visit to the Carnegie Mellon Robotics Lab and posted the video to Microsoft’s channel 9 – which has quite a few interesting videos.

They have some of the coolest people I’ve ever met and the robotics might surprise you (two of the students were building soccer-playing robots on top of Segways, other students were building surgery tools, really great stuff).

More robotics webcasts from Channel 9.

Bacterial Evolution in Yogurt

Adapting to Life in Yogurt by Carl Zimmer:

The analysis, based on the microbe’s newly sequenced genome, suggests that the bacteria descend from microbes that originally fed on plants. Some of them fell accidentally into some herder’s milk, it seems, and happened to clot it and kept it from spoiling. Since then, people have been transferring yogurt to fresh milk time and again, and the effect has been like running a long-term experiment on the evolution of bacteria.

Carl Zimmer provide much more detail in this podcast: evolution of bacteria in yogurt. Continue reading →

The Art and Science of Imaging

Cancer Cell

The Art of Imaging from Invitrogen (via Molecular Probes’ protocols for pretty pictures). See interesting images and details on exactly how to scientists create such images.

image: -catenin in HeLa human cervical cancer cells was labeled using mouse anti–catenin and visualized with Alexa Fluor 488 goat anti-mouse IgG (green). Filamentous actin was visualized using red-fluorescent Alexa Fluor 635 phalloidin. Nuclear DNA was stained with blue-fluorescent DAPI. Larger photo and more details

The image gallery includes many more images.

Re-engineered Wheelchair

photo of new wheelchair

Wheelchairs given design makeover by Geoff Adams-Spink, BBC News

Five years later – a development phase that Mr Spindle describes as “extremely difficult” – Trekinetic chose the Mobility Roadshow to unveil a radical new design.

The K2 has three wheels – two large ones at the front that can take mountain bike tyres – and a smaller one at the back.

The company says it is ideally suited for off-road use but can be just as useful in towns and cities too.

Manufacturers of the wheelchair: Trekinetic. They seem to be getting a bit too much publicity, when I visited I received the following: “This account has exceeded it’s bandwidth quota and has been temporarily disabled.” I would imagine it will be available again shortly.

Cancer Scientists Find Worm Link

Cancer scientists find worm link by Matt McGrath:

Now scientists in California have found that when they removed this same protein from the tiny worm C. elegans, the worms lived up to 30% longer than normal.

The scientists deduced that a lack of this protein might mean that humans also live longer, but with an increased risk of getting cancer.

The researchers think the protein’s dual function raises another important question: does the presence of this protein ensure a short but cancer-free existence for some people?

Entirely New Antibiotic Developed

Potent antibiotic to target MRSA

A potent antibiotic which kills many bacteria, including MRSA, has been discovered. Scientists with Merck, isolated platensimycin from a sample of South African soil and have developed an antibiotic based on that discovery.

If the compound passes clinical trials it will become only the third entirely new antibiotic developed in the last four decades.

Details in the journal Nature reveal the antibiotic works in a completely different way to all others.

It acts to block enzymes involved in the synthesis of fatty acids, which bacteria need to construct cell membranes.

Methicillin-resistant Staphylococcus Aureus (MRSA) is a type of bacteria that is resistant to certain antibiotics, including: methicillin and other more common antibiotics such as oxacillin, penicillin and amoxicillin. Staph infections, including MRSA, occur most frequently among persons in hospitals and healthcare facilities who have weakened immune systems. More information on MRSA is available from the United States Center for Disease Control and Prevention.

Scientific Misinformation

Lactic Acid Is Not Muscles’ Foe, It’s Fuel by Gina Kolata:

But that, it turns out, is all wrong. Lactic acid is actually a fuel, not a caustic waste product. Muscles make it deliberately, producing it from glucose, and they burn it to obtain energy.
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“I had huge fights, I had terrible trouble getting my grants funded, I had my papers rejected,” Dr. Brooks recalled. But he soldiered on, conducting more elaborate studies with rats and, years later, moving on to humans. Every time, with every study, his results were consistent with his radical idea.

Eventually, other researchers confirmed the work. And gradually, the thinking among exercise physiologists began to change.