Welcome to The Deep science and technology column where we cover topics from the deep sea to deep space and beyond.
Greetings everyone. Well, we had quite a bit of feedback on last week’s article on snakes. Many people think that the spread of the giant snakes into the southern US will be impossible because of the winter conditions. I certainly hope they’re right!
There were also a few comments about my story about Pete, the reticulated python. Someone pointed out that a three-foot long snake would hardly weigh 30 pounds and I suspect they’re right. I didn’t know Pete back then and I suspect five or ten pounds would be much more realistic.
I never personally weighed Pete either and have no clue if the 300-pound figure in the days when I knew her was actually accurate, but I can tell you from personal observation that the 33-foot length was certainly close to the truth. When she raised her head to my eye level, most of her was still on the ground!
We’ll leave the animals behind this week and concentrate on the planet’s most populous large animal and their woes. [For you sticklers out there, notice that I did NOT say ‘most populous life form’ (bacteria) or ‘most populous animal’ (insects)].
Certainly at the top of human woes is cancer. This dreadful disease, where the body’s own cells go rogue (sorry, Ms Palin) seems to be on the upswing. But there’s hope on the horizon from some unexpected sources.
NEW HOPE FROM JEWELERY?
We’ve known for a long time that heat is an excellent weapon against cancer cells. But it’s hard to cook tumors without cooking the surrounding tissue too.
Now, researchers from MIT are using tiny particles of gold to home in on tumors. Then the gold absorbs energy from near-infrared light and re-emits it as heat. This destroys tumors with minimal side effects. The particles called gold nanorods, can be used to diagnose as well as treat tumors.
Cancer affects about seven million people worldwide, and that number is projected to grow to 15 million by 2020. Most cancer patients are treated with chemotherapy and/or radiation, which are often effective but can have debilitating side effects because it’s difficult to target tumor tissue.
Gold nanoparticles can absorb different frequencies of light, depending on their shape. Rod-shaped particles absorb light at near-infrared frequencies. This light heats the tiny rods but passes harmlessly through human tissue.
In the study, tumors in mice that received an intravenous injection of nanorods plus near-infrared laser treatment disappeared within 15 days. The mice survived for three months (the end of the study) with no evidence of reoccurrence. Mice with tumors who received no treatment or only nanorods or only laser heating didn’t have that kind of survival rate.
Once the nanorods are injected, they disperse uniformly throughout the bloodstream. The research team developed a polymer coating for the particles that allowed them to survive in the bloodstream longer than any other gold nanoparticles (the half-life is greater than 17 hours).
In designing the particles, the researchers took advantage of the fact that blood vessels located near tumors have tiny pores just large enough for the nanorods to enter. Nanorods accumulate in the tumors, and within three days, the liver and spleen clear any that don’t reach the tumor.
During a single exposure to a near-infrared laser, the nanorods heat up to 70 degrees Celsius, hot enough to kill tumor cells. Additionally, heating them to a lower temperature weakens tumor cells enough to enhance the effectiveness of existing chemotherapy treatments, raising the possibility of using the nanorods as a supplement to those treatments.
The nanorods could also be used to kill tumor cells left behind after surgery. The nanorods can be more than 1,000 times more precise than a surgeon’s scalpel, so they could potentially remove residual cells the surgeon can’t get.
The nanorods’ homing abilities also make them a promising tool for diagnosing tumors. After the particles are injected, they can be imaged using a technique known as Raman scattering. Any tissue that lights up, other than the liver or spleen, could harbor an invasive tumor.
Another advantage of the nanorods is that by coating them with different types of light-scattering molecules, they can be designed to simultaneously gather multiple types of information – not only whether there is a tumor, but whether it is at risk of invading other tissues, whether it’s a primary or secondary tumor, or where it originated.
The researchers are looking into commercializing the technology. Before the gold nanorods can be used in humans, they must undergo clinical trials and be approved by the FDA, which will be a multi-year process.
MIT researchers developed these gold nanorods that absorb energy from near-infrared light and emit it as heat, destroying cancer cells. (Credit: Photo / Sangeeta Bhatia Laboratory; MIT)
Some how I’d never considered using gold as a cancer killer. Gold is one of the most inert things we know about and I don’t think I’d worry too much about being injected with gold nanorods if I was staring cancer in the face.
But gold isn’t the only new option. A old drug that I take every day and that many of you take as well, has been found to have some astounding new side effects.
NEW HOPE FROM OLD DRUGS
Researchers at the Harvard Medical School have found a drug that not only reduced tumors, but prolonged remission in mice longer than conventional chemotherapy. It apparently works by targeting cancer stem cells. What is this new miracle drug? Metformin, also known as glucophage.
There is a growing body of evidence in cells, mice and people that metformin may improve breast cancer outcomes in people. In the current study, the diabetes drug seemed to work independently of its ability to improve insulin sensitivity and lower blood sugar and insulin levels, all of which are also associated with better breast cancer outcomes.
The results fit within the cancer stem cell hypothesis, an intensely studied idea that a small subset of cancer cells has a special power to initiate tumors, fuel tumor growth, and promote recurrence of cancer. Cancer stem cells appear to resist conventional chemotherapies, which kill the bulk of the tumor. The cancer stem cell hypothesis says you can’t cure cancer unless you also get rid of the cancer stem cells.
The possible usefulness of metformin against cancer supports an emerging idea that, in the vast and complex alphabet soup of molecular interactions within cells, there are a few biological pathways that may be important in the development of many different diseases.
In mice, pretreatment with metformin prevented the otherwise dramatic ability of human breast cancer stem cells to form tumors. In other mice, where tumors were allowed to take hold for 10 days, the dual therapy also reduced tumor mass more quickly and prevented relapse. In the two months between the end of treatment and the end of the experiment, tumors regrew in the mice treated with chemotherapy alone, but not in mice that had both chemotherapy and metformin. But in an interesting side note, metformin was ineffective in treating tumors when used by itself.
The researchers have applied for a patent for a combined therapy of metformin and a lower dose of chemotherapy, which is being tested in animals. Hopefully, the results will be very good and be in soon.
is rampant here on Guam and one of the unfortunate side effects of diabetes is kidney disease. There’s also some good news in that department.
NEW HOPE FROM GETTING OFF THE COUCH
Getting off the couch could lead to a longer life for kidney disease patients, according to a study that appeared in the Clinical Journal of the American Society Nephrology (CJASN). The findings indicate that, as in the general population, exercise has significant health benefits for individuals with kidney disease.
Many patients with chronic kidney disease die prematurely, but not from effects directly related to kidney problems. Because physical activity has known health benefits, researchers at the University of Utah looked into the effects of exercise on people with chronic kidney disease.
The study included 15,368 adult participants (5.9% of whom had chronic kidney disease [CKD]) in the National Health and Nutrition Examination Survey III, a survey of the US population. After answering a questionnaire on the frequency and intensity of their leisure time physical activity, participants were divided into inactive, insufficiently active, and active groups. On average, participants were followed for seven to nine years.
The researchers found that 28% of individuals with CKD were inactive, compared with 13.5% of non-CKD individuals. Active and insufficiently active CKD patients were 56% and 42% less likely to die during the study than inactive CKD patients, respectively. Similar survival benefits associated with physical activity were seen in individuals without CKD.
"These data suggest that increased physical activity might have a survival benefit in the CKD population. This is particularly important as most patients with stage III CKD die before they develop end stage renal disease," the authors wrote.
So, it looks like getting off that couch is good for everybody and now that I’ve finished this article, I’m going to do just that. Why don’t you join me?