Recent comments in /f/askscience

oviforconnsmythe t1_j7onh5c wrote

Reply to Does having autoimmune disorder (atopic disease in my mind, but also otherwise) lead to an increased risk of immune cell cancer? by MoBuckeye

In theory, yes increased turnover/expansion of immune cells in inflammatory contexts can lead to increased frequency of oncogenic mutations that turn into hematological cancers. Each round of cell division has the possibility to introduce oncogenic mutations (mutations in genes that transform a normal cell into a cancerous one) as a result of DNA replication errors. But there are also many mechanisms to correct such errors or kill off cells with oncogenic mutations. So the chance of cancers arising solely from this mechanism are low and there are a number of other factors that play more substantial roles in cancer formation.

The conditions you listed are associated with chronic inflammation. Chronic inflammation has been widely established as a risk factor for many different cancers. While increased cell turnover (e.g. immune cells in inflammatory settings) can potentially enhance the risk of oncogenic mutations, the inflammatory microenvironment (i.e. both cellular composition and factors secreted by theses cells in inflamed tissue) itself is likely a much more substantial driver of cancer formation. For example, remodeling of the extracellular matrix (ie the scaffold that forms tissue structure) is an important feature of inflammation but is also critical for metastasis and/or formation of blood vessels (angiogenesis) that could feed a growing tumor. Immune cells in inflamed tissue can secrete MMPs (which break down and remodel the extracellular matrix) and angiogenic factors. While the immune system/inflammation is essential to kill cancerous cells in tumors, some subsets of immune cells present in the tumor microenvironment (TME) secrete factors that suppress the anti-cancer immune response. Chronic inflammation can enhance or induce these suppressor subsets. Here's a nice review on the mechanisms by which inflammation drives cancer formation.

For your question specifically, there is a JAMA paper that reports an association between atopic eczema and lymphoma risk. It's not a particularly strong association, but they did find that the lymphoma risk correlates with eczema severity. Given that the potency of the inflammatory response determines severity, this is in line with what I mentioned above. In theory, controlling inflammation (which is the principle behind most eczema therapies) should reduce the cancer risk. But broad immune suppression increases the risk of infection. Infection with Epstein-Barr Virus (EBV-one of the causative agents of mononucleosis) is a well-recognized risk factor of development of both Hodgkin's and Non-Hodgkin's lymphoma. EBV infects lymphocytes and encodes proteins that contribute to cancer cell transformation and augment the TME to make it more suppressive. Other viruses have also been associated with this before. EBV driven lymphomas are a potential complication in transplant patients (which receive potent immunosuppressant drugs to increase transplant success).

So overall, yes chronic inflammatory diseases like eczema or asthma can potentially promote cancer but not (solely) through the mechanism you describe. I hope I've been able to help your prospective study (which I think you should definitely write, its a really neat hypothesis)!

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steeltowndude t1_j7onfl2 wrote

Reply to comment by TPMJB in Why aren't anabolic steroids/HGH prescribed for patients recovering from wounds/grafts? Wouldn't the steroids speed up recovery time? by TPMJB

(Neither a doctor nor scientist) My first assumption would be that it would actually pose additional threat of re-injury. Tendon injuries, for example, are more common in AAS users, I would assume because the strength of the muscles progresses at a rate at which the tendons can't keep up (not sure if the exact reason why has been studied). AAS would allow one to regain muscle mass and strength quickly during recovery, but it's not doing much for the thing that you tore in the first place.

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GalaxyGirl777 t1_j7omb3g wrote

Reply to Do Little Earthquakes Prevent Big Earthquakes? by cpassmore79

You might like to look up ‘slow’ or ‘slow-slip’ earthquakes which occur over a much longer timescale than your typical short sharp earthquake but can release just as much energy. It doesn’t answer your question about pressure, but it is interesting to note that there are slo-mo events occurring in faults around the world.

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h3rbi74 t1_j7okpef wrote

Reply to Are nocturnal animals active for longer periods in the winter? by Toorelad

Your question isn’t as straightforward as it seems because many animals aren’t strictly “nocturnal”, different populations of them may tend to be active at different times for different reasons other than just night/day (such as local human activity, weather/temperature, availability of food during a particular time of year).

Here is a 2-year study of several different mammals in Japan based on camera traps, showing that some animals shift their activity patterns seasonally: Seasonal and Diel Activity Patterns of Eight Sympatric Mammals in Northern Japan Revealed by an Intensive Camera-Trap Survey

Interestingly, instead of being more active at night when winter nights are longer, some crepuscular (normally active at dawn and dusk) animals such as deer became more diurnal in winter— the authors hypothesize that it’s because winter nights are cold so it’s better to be active when the sun is up.

For wolves specifically, since you mentioned them, they are one of those species that is highly adaptable and not always strictly nocturnal or crepuscular. There is some good discussion of that in this article: Daily Patterns and Duration of Wolf Activity in the Białowieza Forest, Poland

> This causes dissimilarities in activity patterns of wolves from different study sites: wolves were nocturnal in Italy (Ciucci et al. 1997); nocturnal with a tendency to bimodal activity in Spain (Vilà et al. 1995); active throughout day and night in Ontario, Canada (Kolenosky and Johnston 1967); and most active from 2200 to 0600 h in summer and from 0700 to 1600 h in winter in Alaska (Fancy and Ballard 1995).

The sources are clickable in the linked article if you want to learn more!

These authors found their particular wolves remained basically crepuscular year round, and believe that weather and prey availability/behavior affect their activity patterns more than human activity nearby or other factors, but they specifically call out that in other parts of the world, different circumstances apply and you end up with different results.

Also from the same paper:

> If wolves adapted their behavior to avoid direct contact with humans, they might have become less active during the day. Indeed, wolves studied in mountainous agricultural regions of Spain and Italy with human densities of 20–30 inhabitants/km2 hardly moved during daylight (Ciucci et al. 1997; Vilà et al. 1995). In Alaska, where human density is low, wolves moved during 50% (Peterson et al. 1984) of the daylight. In forests of Minnesota, where human density in the wolf range was 1.5 inhabitants/km2 (Mladenoff et al. 1995), wolves moved during 28% of the daylight in winter (Mech 1992). In the Białowieża Forest, persecution does not seem to have caused wolves to reduce their activity and movement in daylight, perhaps because our study area is mostly covered by forest. In Italy and Spain, where <40% of the area in the wolves' home ranges was forested (Ciucci et al. 1997; Vilà et al. 1995), there may not have been enough cover for daylight movement. Human activity therefore does not seem to significantly influence temporal activity patterns of wolves in regions where they have the opportunity to avoid direct contact with humans.

So you can see there’s not just one simple answer to your question!

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Evening-Leek-7312 t1_j7oj740 wrote

Reply to What evidence is there for non-physical attributes being passed down from ancestors to their descendants through DNA? by PeanutSalsa

One of the basic ones that was covered in my ecology class was mating rituals, at some point the idea that you were a good mate got tied to some random action and therefore creatures who can do that ritual well are more likely to pass on their genetic material

Some examples of this are birds dancing and the pufferfish basically making artwork on the sea floor

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