Thirdhand Smoke Causes DNA Damage

Yepp, you read the title right. Researchers from the Lawrence Berkeley National Laboratory found that Thirdhand smoke, not just secondhand smoke, can break DNA strands and can cause oxidative damage to a cell's DNA, which can lead to genetic mutations (and as a result, cancer). Thirdhand smoke refers to the residue produced from smoking cigarettes. You know, the nasty smelly stuff that sticks to your clothes, carpet, counters, and well, just about everything! Exposure to these carcinogens can come from not only ingestion and inhalation, but skin contact as well. And even worse? Studies have found this residue isn't easily eradicated, and that with standard cleaning methods, it can take up to two months to completely get rid of the residue.

                               
If you're interested in the science of how smoke residue could damage DNA, one of the more popular residual ingredients, nicotine, is a carcinogen in that it reacts with nitrous acid to produce nitrosamines like N'-nitrosonornicotine (NNN) and 4-(N-methyl-N-nitrosamino)-4-(3-pyridyl)-1-butanal (NNA), which have mutagenic potential and can react with DNA.

People really argue the smoking bans in public places? Is it really okay to put a person's health at risk because of another's bad habit? There is a tremendous amount of evidence that demonstrates smoking can be harmful (in more ways than one, it seems), so why is it even an issue?

This research is just more evidence that smoking around others who choose to avoid the habit are, well, a little inconsiderate.


References: http://mutage.oxfordjournals.org/content/28/4/381

There's a Cure for Cancer...There's Just no Money in it!!

A funny thing I hear pretty often is that cures for cancer have already been discovered, but the pharmaceutical companies are keeping them to themselves because they wouldn't make any money off of them. A truly face-palm-worthy statement that only serves to highlight the ignorance of the people who mention it.

These people aren't only too ignorant to understand the mechanisms of cancer or fathom a way to treat it, but they also have the audacity to imply an actual cure would be easy and cheap? Funny stuff!

Take, for example, chronic myelogenous leukemia. We know that a translocation between chromosomes 9 and 22 (known as the Philadelphia chromosome) results in the condition of CML. So basically, curing this would require changing someone's DNA (and I'll go ahead and give you a hint that curing likely any cancer would require this, as well). Well guess what, last time I checked, we couldn't willfully change someone's DNA to whatever we desired. If we could, you can bet your bottom that these same pharmaceutical companies that are "hiding our cures" would be marketing it to give people any traits they wanted and would be making bank from it, too. Oh, but they're not, because they can't!

But let's go ahead and assume there is a cure for cancer (there's not) that the big pharmaceutical companies are keeping from us. So why is it that CEOs for these companies fall victim to cancer? Surely they could treat themselves if they knew how! Also, if they're hiding a cure so they can keep charging patients and making money from them, why is it that they can't develop a decent enough treatment to keep them alive long enough to keep charging them? But they can develop a cure? Really? The logic among some astounds me.

Note: I've emphasized the word "cure" several times because I don't think many people really understand the complete implications of the word. You can treat a disease to the point where it isn't harming the patient or causing any problems, but that doesn't mean it's been cured.

The Effect of Alcohol on Renal Collecting Tubule Permeability

Why do you feel like you need to pee so much when you drink alcohol? Well, part of the answer is that you're consuming more liquid than usual, so of course there's going to be more coming out of the other end. But there's more to it than that. I'll go ahead and give a short, simple answer, and then you can read in detail if you want.

In short: Alcohol inhibits the release of a hormone that usually keeps water in the body. So when alcohol is present, water basically just goes straight through you.

Let's start in the brain. The hypothalamus is a very important brain structure with a multitude of different functions in the human body. The function important in this discussion is its role in stimulating the pituitary gland, particularly the posterior pituitary in this case. In the posterior pituitary gland are two main hormones: vasopressin, aka anti-diuretic hormone (ADH), and oxytocin. Normally, the hypothalamus stimulates the pituitary to release vasopressin, which then plays a major role in the kidneys among other things. When you ingest alcohol, however, it interacts with the hypothalamus, resulting in an inhibition of the hormone and ultimately less ADH in the kidneys.

Here's a simple picture of the hypothalamic-pituitary system:



Now we'll move on to what usually happens in the kidney (well, just what's important anyway, there's a lot more to it than this and I don't feel like writing a book!). The kidney is composed of many structures called nephrons. There are about 1 million of these in each kidney! When plasma enters into the kidney, it is filtered in the glomerulus, which is basically just some specialized capillaries. The constituents of the filtered fluid are then either reabsorbed into the bloodstream, or pass through the nephron and into the bladder, where it is eventually excreted. Normally, most of the water that passes through the nephron is eventually reabsorbed. Some of this water is absorbed in the collecting tubule of the nephron, which you can see pictured below. When vasopressin is present, the hormone increases the permeability of these tubules, and thus water is readily absorbed back into the blood. In the absence of vasopressin, the tubules are less permeable, so water isn't as easily absorbed and instead goes into the ureters and then the bladder.



We'll put it all together now. Alcohol interacts with the hypothalamus, inhibiting the release of vasopressin (ADH) from the posterior pituitary gland. As a result, the collecting tubules in the kidney are less permeable to water, so the liquid will be more likely to pass through the nephron, into the bladder, making you have to pee more than usual. It's as simple as that!