Search for tag: "lifespan"

Interviewer: A social lifestyle with plenty of mental activity and exercise slows down cancer according to research in mice. We'll talk about that next on The Scope.

Announcer: Examining the latest research and telling you about the latest breakthroughs, The Science and Research Show is on The Scope.

Interviewer: I'm talking with Dr. Melinda Angus-Hill, an investigator at the Huntsman Cancer Institute at the University of Utah. Dr. Angus-Hill, I really love this story. Your research is showing how a change in lifestyle can really impact the trajectory of cancer.

Dr. Angus-Hill: We have a mouse model that is meant to replicate colon cancer in humans. We've developed genetic mutations that profoundly influence the numbers of colon tumors that these animals get and we found that with enriched lifestyle, which includes improved social interactions with lots of other mice, they have huts and crawl balls and lots of things that they can do, lots of activities, they have wheels that they can run on, and we found that these improved social interactions and these things that they can do increase their lifespan of both males and females significantly.

Interviewer: By how much?

Dr. Angus-Hill: So, these mice, normally, begin to get sick with colon tumors at around three to four months old and they'll live two to three months longer than that with the environmental enrichment.

Interviewer: Which is pretty significant for a mouse?

Dr. Angus-Hill: Yes, very significant.

Interviewer: Like you mentioned, they're subject to a lot of changes compared to regular lab mice. I mean, you said they're around a lot of other mice, they're getting exercise, they're, you know, maybe just faced with a more interesting environment than they would usually have. Do you know if . . . it is a combination of those things that are impacting the mice or can you parse it out into one of those changes?

Dr. Angus-Hill: Well, I think it is actually all the entire environment that does this. There have been a lot of studies that have looked at exercise and the effects on tumor genesis and, basically, they give a single mouse a wheel and mice can run on the wheel as much as they like, and will often just spend the whole day running. They can run up to six kilometers a day under those conditions and that can actually be stressful on mice, but it will still have an effect on whether the size of the tumors decrease and whether the animals actually feel better. But it seems that this environmental enrichment is more a well-rounded approach where the animals, they can run if they like to, but there are many other things that they can do and that seems to improve in a different way than just running on a wheel.

Interviewer: So a lot of your work here which is really the advantage of working in mice or a model organism is trying to understand, you know, biologically, what's going on here. How is this environmental enrichment changing the biology of these mice? I mean, first of all, what's happening with the cancer? Is it not starting in the first place? Is it just progressing slower than cancer normally would? What are you seeing at that level?

Dr. Angus-Hill: Sure. It seems that we don't have a decrease in the numbers of tumors that actually initiate, which suggest that the genetic mutations that occur, you can't really stop them from occurring with environmental enrichment. However, it seems that we can actually make the tumors better. So, if a tumor can be better . . .

Interviewer: Yeah.

Dr. Angus-Hill: But the idea is that with environmental enrichment, there is less inflammation which results in what we think is, actually, a cause of a healing phenotype that occurs when the mice are environmentally enriched. So, basically, the tumors become more benign and they are less offensive. So, in the context of cancer, these tumors would be less likely to invade and metastasize, and become a serious problem.

Interviewer: Right. And you were talking about how it seems to trigger a wound healing process, which seems a little counterintuitive to me. I mean, what does wound healing have to do with cancer?

Dr. Angus-Hill: We were actually able to show that the animals, the male animals in particular, had an improved wounding process that happened in their colons. Basically, their tumors healed themselves with this environmental enrichment.

Interviewer: Like wound healing in our skin or . . .

Dr. Angus Hill: It's actually been most well-characterized in the skin and it has to go through multiple steps in order to complete the healing process, and so it has to get worse before it can get better. So there are several steps, including recruitment of inflammatory cells, increased angiogenesis which is making more blood vessels, and then, basically, the wound can resolve by re-epithelializing the cells and then, ultimately, a scar will be formed, and all of this will result in decreased inflammation.

So we saw decreased inflammation with environmental enrichment. This suggested to us that the colons and the colon tumor, this barrier that is normally essential for maintaining the . . . keeping the bacteria out, but also maintaining the normal cell structures in the colon were actually being helped with environmental enrichment.

Interviewer: I mean, this is really a different way of thinking about things. I mean, are you excited about sort of the possibilities here or . . .

Dr. Angus-Hill: Yeah. I think it's kind of a new idea that really, it's not super appealing to pharmaceutical industries, but it's something that everybody can take to heart and know that it's possible that reducing stress can actually improve your gut, you know, even just inflammation in general, and I think more studies are definitely needed to determine whether this translates to people, but you know, what harm is there in reducing stress? There are none. There are no harms to reducing your stress.

Announcer: Interesting, informative, and all in the name of better health. This is The Scope Health Sciences Radio.

Dr. Miller: You've had a hip or knee replacement and need a revision, we're going to talk about that next on Scope Radio.

Announcer: Access to our experts with in-depth information about the biggest health issues facing you today. "The Specialists," with Dr. Tom Miller, is on The Scope.

Dr. Miller: Hi, I'm here today with Dr. Chris Pelt. He's an orthopedic surgeon here at the University of Utah in the Department of Orthopedics. Chris, talk a little bit about how long a hip or knee replacement lasts. Obviously, that's pretty variable. But when that begins to wear out, and I'm sure in a certain percent of people it does, what's the next step?

Dr. Pelt: Historically, a hip replacement would last 10-15 years. Newer technologies have been developed, which allows the hip replacements to be lasting closer to the 30-year time point, when we look at these on wear simulators, we haven't had the technology 30 years now, but when we look at the available information and literature it looks like it could last much longer than historically.

Dr. Miller: So when they wear out, does the actual prosthetic device wear out or do they come loose? What actually happens? What's more common?

Dr. Pelt: There are three main wear mechanisms or failure mechanisms. One is that the bearing will wear out so the plastic liners can get worn and you can replace the plastic liners. More commonly, however, what we find is that the implants can get loose from the bones or the worst of all of the complications would be infections of the implants. And a lot of the referrals that we do see come from outside in the community hospitals, they refer to us for complications related to infections.

It's one of the more common failures in early time points when a joint replacement fails, but it can happen later in life as well, it can happen when bacteria get into our bloodstream and they find their way to the artificial joints. Metal and plastic do not have an immune system so when bacteria are in our bloodstream, whether it's from an infection in our mouth, dental work, an infection of a toe or any other type of infection in our body, a bacterial infection, it can find its way to our hip replacements. We want to be careful about that when patients are undergoing treatments for other medical issues.

Dr. Miller: Well, based on how patients present with either one of those three things, I guess you craft the repair or surgery to meet that problem. I would imagine a revision surgery is probably a delicate or complex surgery compared to an initial hip replacement or knee replacement.

Dr. Pelt: It's quite a bit more complex. It takes a little bit more expertise and skill because it can be very easy to have a revision surgery and have things go wrong.

Dr. Miller: How long, then, does that revise tip last? Does it last as long as the initial implant or are people looking at a little less lifespan on the hip or knee?

Dr. Pelt: It depends. It depends on what the problem is that we're treating and what implants we have to use to deal with that reconstruction. But, on average, they should last similar time frames to the initial index operation. Some of these will be, hopefully, the last surgery the patient needs to have in their lifetime.

Dr. Miller: Now, patients who present with the infected hips, I think you probably take the old device out and then either put in a new device or wait until the infection has been treated. But I imagine that treatment goes on for several weeks with antibiotics. Is that right?

Dr. Pelt: That's right, yeah. We've taken a lot of pride and created a significant team around the treatment of joint replacement infections here at the University of Utah. We have infection disease specialists, our internal medicine colleagues, ourselves as orthopedic surgeons, our nurses, physical therapists, physician assistants and a bunch of other people that help us take care of our patients. But yeah, the surgery is required initially to take the device out and get rid of all the bacteria out of the joint.

We place a temporary antibiotic-laden or antibiotic-containing spacer with some temporary parts that'll allow the hip or knee to still move the way it typically would and after about three months of treatment with antibiotic and a drug holiday, we often will be able to take the temporary device out and replace it with a permanent device again.

The typical revision joint replacement surgery we may not allow to bear weight on the limb that was just operated on right away. Often, after a primary hip or knee replacement, we have the patients up and walking, with full weight bearing, the day of the surgery. With revision surgery, depending on what it is we are doing, but with most revision surgery, that often is delayed. So we won't let them . . .

Dr. Miller: Both knees and hips?

Dr. Pelt: Both knees and hips. Typically for about six weeks. And the reason is as we mentioned when we are dealing with bone loss and having to accommodate or account for that with bigger and larger implants, sometimes, we need biology to be on our side.

Dr. Miller: It's almost like a fracture that needs treatment so you can put weight on it.

Dr. Pelt: It's almost like treating a fracture. Exactly. So we're waiting for bone in-growth to happen to the implants before we start putting too much weight and start making micro-motion or something that could compromise the stability or fixation. So typically, they're going to be at least six weeks behind where they might have been after their index or primary joint replacement surgery.

After which time, we start ramping up some more of their physical therapy, start getting walking on it, start getting them to strengthen their muscles with some weight and resistance modalities finally, where they probably have not been doing those in the first six weeks. And so they can just expect a little bit long time point until they get back to their maximum improvement point.

Dr. Miller: Initial replacements, they are out of the hospital pretty quickly these days. How long would they expect, on average, to be in the hospital after a revision?

Dr. Pelt: Our typical primary joint replacements will go home the next day, sometimes the latest two days after surgery. A revision surgery has an average length of stay of around three days. Some patients will go home around day two, others around day three, sometimes even day four, but about a day or two longer in the hospital. That's mostly because they're trying to account for the weight bearing restrictions, the mobility needs that they have to get used to after having the revision surgery. So our physical therapists are going to be working with them in the hospital, trying to get them to do the things that they'll need to be able to do when they get out of the hospital

Dr. Miller: Now, you have patients coming from cities distant to Salt Lake. So, interestingly, once they leave the hospital, how do you make sure that the therapy they are getting in their hometown is going to be adequate?

Dr. Pelt: So we have patients that fly in from northern Montana, Wyoming, Idaho, Nevada, Colorado, Arizona, New Mexico all to have their surgeries done here with us. And it is difficult. We do have, like I said earlier, we do have a big team, including some of our care coordinators and our nurse coordinators that help kind of reach out and make sure our patients are doing well after surgery. We call our patients pretty frequently.

We write pretty strict and standardized protocols and instructions to send home with our patients when they leave the hospital so the physical therapists are able to follow those directions pretty closely. And that way, we don't compromise anything that may be a difference in how they treat things in one place vs how we do here. We try to give them those instructions so it is very clear on what our expectations are when they leave the hospital. And then our team of care coordinators and nurses are going to be calling and ensuring that everything is going right as the weeks progress.

Dr. Miller: So their therapist, no matter where they would be, would be able to contact your care team to figure out if there we any things that they need to modify or revise in terms of the treatment?

Dr. Pelt: Absolutely.

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