Recent comments in /f/askscience

Yitram t1_j3ei7t8 wrote

Reply to comment by Sinemetu9 in How does DNA encode 3d space/information? by Rit2Strong

You're not wrong. Think of cells as a factory making a product. In cancer, not only is the product wrong but you can't shut off the factory. Also why cancer is so awful if you get it younger. To go back to the factory analogy, in a young person, the factory is shiny and new and efficient, so it makes the cancer really fast. Whereas in an older person, the factory already isn't in the greatest of shape, even before the cancer.

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uh-okay-I-guess t1_j3ehodi wrote

Reply to How does the renal HCO3- reabsorption increase blood pH? by HugoBossPT

It doesn't directly eliminate H^+ from the body. As you said, there is net zero transport of H^+. Instead, a base (bicarbonate) is reabsorbed into the body.

You should not believe that every bicarbonate ion actually reacts with an H^+ ion -- there is a complex buffered equilibrium. But each reabsorbed bicarbonate shifts that equilibrium slightly toward the alkaline side, because it has the capacity to accept an H^+.

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CrateDane t1_j3egc41 wrote

Reply to comment by artlabman in How does DNA encode 3d space/information? by Rit2Strong

It used to be we thought of just apoptosis and necrosis, with apoptosis being a clean and deliberate suicide, while necrosis was a messy and uncontrolled cell death.

While those are still very valid, it's turning out that there are a lot more ways for cells to die.

There's necroptosis which is controlled like apoptosis, but messy like necrosis. There's ferroptosis which is iron-reliant and happens in response to excessive oxidation. There's anoikis, which is very similar to apoptosis but initiated by lack of contact to extracellular matrix. There's NETosis, where a type of immune cell called neutrophils eject their DNA as a sticky net to capture pathogens. There's pyroptosis which is triggered by the inflammasome and strongly stimulates inflammation to combat mainly intracellular pathogens.

There are a few more I've left out, probably a few more I haven't heard of, and then all the ones we might not have discovered/characterized yet.

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bettinafairchild t1_j3eevy9 wrote

Reply to Leishmania is a parasite that targets immune cells. Why is it less dangerous than HIV? by robotisland

In addition to what others have said, keep in mind that from the time AIDS was first observed until about 1996, there was no treatment for AIDS and it was a death sentence. And during all that time, it’s not like people could say “soon we will have a treatment.” We simply didn’t know when I’d ever there would be a treatment. When if ever AIDS would stop being a death sentence. For those of us alive at that time, that’s a frightening feeling that is hard to let go of. It lingers even today. Adding to that was the stigma surrounding the disease which is a miasma surrounding feelings about it. But Leishmania has a cure. It never had all that emotion surrounding it .

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provocative_bear t1_j3edpp2 wrote

Reply to comment by artlabman in How does DNA encode 3d space/information? by Rit2Strong

Apoptosis is a "planned" cell death, where either the body commands the cell to kill itself because it's no longer useful or the cell is mortally wounded and dies a tidy death by suicide for the good of the body.

In contrast, cell necrosis is sudden, "messy" cell death that is not considered apoptosis. It can cause problems for surrounding cells as debris, signaling molecules, and even digestive enzymes get released uncontrolled from the dying cell.

Cancer cells are damaged (usually genetically) in a way that causes them to ignore the body's signals to commit apoptosis, but also to ignore signals to not divide and to stay where they are.

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mpinnegar t1_j3e99t2 wrote

Reply to comment by Sinemetu9 in How does DNA encode 3d space/information? by Rit2Strong

Cells have a variety of processes going on inside of them to do things like maintain homeostasis, replicate, fix DNA errors, produce power, etc. They even have machinery to self terminate when something goes wrong.

In a cancer cell one of the processes has broken down and the self termination process has ALSO broken down. Once that's happened you essentially have a rogue cellular factory inside of your body that can hijack the resources you need to survive and can replicate itself going from one cell to enough to kill you by any number of factors. The cancer could just physically put pressure on organs like the brain. It could produce a wild amount of signaling hormones therefore causing secondary non-cancerous cells to follow erroneous instructions. It could also take over resources that other parts of your body need to survive.

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