-->

Saturday, November 26, 2011

Protect Your Unborn or Newborn Baby: Secondhand Smoking’s Association to Asthma


Do you know someone with asthma? Chances are that you do. In 2009, over 8% of the US population reported that they currently had asthma. Interestingly, asthma rates are the highest among children and teenagers (Akinbami et al., 2011). Allergic asthma in particular is the type of asthma that is most commonly found in children. Allergic asthma, also known as atopic asthma, affects the lower respiratory tracts. Inhalation of an allergen leads to the release of granules from sensitized cells called mast cells that are located in the mucus of a person’s nose or bronchi (which serve as passageways into his or her lungs). The release of these granules and other molecules favour inflammation. This causes abundant amounts of mucus to be secreted and the tightening of a person’s airways. Asthmatics routinely report feelings of constriction in their chest as well as wheezing. Given this information, you might ask the following question: what factors contribute to the development of allergic asthma? Exposure to cigarette smoke during fetal development and during a child’s infancy has been shown to be a risk factor for allergic asthma (DiFranza et al., 2004). Mice exposed to secondhand smoke (SS) early-on after birth also seem to develop respiratory infections (Phaybouth et al., 1006), and can be used as a model for this disease. The specific contributions of exposure to smoke that is either prenatal (before birth) or early postnatal (after birth) in the development of allergic asthma, however, is not well understood. Also, the specific way in which exposure to cigarette smoke leads to asthma is not understood in great detail. To shed some light on these topics, researchers decided to use a mouse model to study the development of allergic asthma (Singh et al. 2011).

Pregnant mice were exposed to smoke released from the burning end of a cigarette (SS) or filtered air (FA) for six hours per day and seven days a week. This level was the same level of secondhand smoke exposure that a pregnant mother would be exposed to if she spent three hours per day in a smoking bar. The pregnant mice were exposed to one of the conditions for the entire duration of their pregnancy (as well as for two weeks before mating) to cause prenatal fetal exposure. After birth the mice pups were exposed to either FA or SS for eight to ten weeks. (Thus, there were four combinations of postnatal/prenatal exposures in total: FA/FA, FA/SS, SS/FA, and SS/SS). Researchers discovered that prenatal, but not postnatal, exposure to secondhand smoke increased airways’ hyperreactivity (measured with a system that calculates airway resistance or tightness) in the mice after they were exposed to an allergen (which contains an antigen that can lead to allergic responses) called A. fumigatus. Therefore, secondhand smoke before birth seems to have made the lungs of the mice pups more constricted and hyperreactive.
The researchers also desired to observe the presence of Th2 cytokines (which are small proteins) in the lung. After all, allergic asthma is characterized by the presence of Th2 cells, which can be seen both in human (Holt et al., 2010) and mouse (Cates et al., 2007) models of the disease. What exactly are Th2 cells though? Th2 cells originate from Th cells. Th cells are found in your body and can be involved in mounting an immune response against a pathogen. Naïve Th cells become “activated” through a series of events including the recognition of specific complexes called pMHC complexes, which contain an antigen (that was originally part of a pathogen) that can be identified by a receptor on the Th cell. Other events such as costimulation between both the cell that is presenting the pMHC complexes and the naïve Th cell, and the release of cytokines, fully activate the Th cell; this cell is then referred to as a Th0 cell. Extracellular pathogens can cause an unknown cell type to secrete one specific kind of cytokine, called IL-4. IL-4 causes the activated Th0 cells to turn into Th2 cells. These Th2 cells, in turn, release specific cytokines which help to fight off said extracellular pathogens. IL-13 and IL-4 are two of these cytokines that seem to be critical to allergic asthma (Wills-Karp et al., 1998). A previous study by the authors, however, showed that Th2 responses and airway hyperreactivity seem to be regulated by different mechanisms (Singh et al., 2009). That is why the authors decided to investigate whether prenatal and early postnatal SS exposure could differentially affect the process by which Th0 cells become Th2 cells, which is known as Th2 polarization.
To study the effect of prenatal and early postnatal exposure on Th2 polarization, the authors looked at the production of IL-13 and IL-4 in the four aforementioned groups of mice after they were sensitized with the allergen A. fumigatus. The mice exposed to smoke postnatally had a relatively small but significant increase in the levels of the Th2 cytokines. The levels of IL-13 and IL-4 in the lungs, however, were much lower in the mice exposed to SS postnatally when compared to the levels seen in mice exposed to SS prenatally. (These levels were determined using a biochemical technique called an ELISA assay, which relies on antibodies and enzymes to produce a color change which can be quantified and indicate the levels of the cytokines in the samples derived from the mouse lungs.) Therefore, prenatal SS exposure led to a strong Th2 cytokine response in the lungs.
The researchers then wanted to know the specific mechanisms that contribute to the differentiation of Th0 cells into Th2 cells. GATA3 is a transcription factor (which is a protein that affects the expression of specific genes) involved in Th2 differentiation. GATA3 can also cause the expression of genes that are needed to make Th2 cytokines (Zhang et al, 1997). Proteins with the names of Lck, ERK, and STAT6 control the activity of GATA3 (Zhu et al., 2004) (Yamashita et al., 2004), (Kemp et al., 2010). Given these previous findings, the researchers wanted to observe the expression of GATA3 and its influencing proteins in the lungs. To do so, they used techniques called Western Blotting and/or quantitative PCR. Western blotting involves using a gel and electricity to separate different kinds of proteins, which can be transferred onto a membrane and detected using antibodies and reactions that produce color or luminescence. Quantitative PCR is a technique used to tell researchers what the expression level of something (such as DNA or RNA) is. Increased levels of activated (phosphorylated) GATA3 were seen in animals exposed to SS prenatally but not after birth. The same findings were seen with regards to phosporylated ERK 1 / 2, phosphorylated Lck, and STAT6. For these reasons, we now believe that prenatal, but not postnatal exposure to secondhand smoke activates Th2 differentiation through the GATA3 pathway.
The researchers were also interested in the way that SS exposure, either prenatally or postnatally, affected the formation of mucus in the lungs of mice. The mucus in your lungs can serve as an anatomical barrier to physically prevent inhaled pathogens from causing disease and is cleared out regularly. Mucus formation, however, can be impaired in diseases such as asthma. In control animals, exposure to the A. fumigatus allergen caused noticeable increases in the mucus content in the lungs. In all conditions involving secondhand smoke exposure, however, marked decreases of mucus levels in the airways were seen. These levels were quantified by staining tissue with a substance that colored mucus-producing cells pink and then counting these cells to calculate their density. Exposure to prenatal and/or postnatal smoke was shown to limit mucus production, which could hinder an animal’s defence mechanisms against inhaled pathogens.
Mucus in the lungs is made by goblet cells. Goblet cells can also manufacture and release into the mucus certain antibacterial molecules which can break down the cell walls of bacterial pathogens or take away nutrients needed for bacterial growth. SPDEF is a transcription factor which is involved in the development of goblet cells (Chen et al., 2009). Singh and his colleagues looked at the expression of SPDEF in airway epithelial cells in mice using immunohistochemistry. Immunohistochemistry uses antibodies to detect specific proteins in tissues and an antibody-antigen interaction can then be visualized through color-producing reactions. Sensitization with A. fumigatus in control mice strongly upregulated the expression of SPDEF. This would make sense because they would need more goblet cells to make more mucus in an attempt to fight off pathogens. However, the prenatally SS-exposed mice could not increase the expression of SPDEF in their airways. The SS/FA animals had levels of SPDEF that were actually lower than the levels seen in the non-sensitized control mice! Sensitized mice exposed to SS postnatally also had much lower levels of SPDEF than sensitized controls. These results seem to tell us that different expression levels of SPDEF may affect goblet cells and impair mucus production in mice exposed to secondhand smoke.
These researchers certainly shed some light on the mechanisms that are related to both prenatal and postnatal secondhand smoke and the development of allergic asthma. Prenatal SS causes a strong Th2 response in the lung (probably through a GATA3 pathway) and increases SS airway hyperreactivity (which was not seen with postnatal SS). Additionally, prenatal and/or early postnatal SS exposure leads to reduced mucus formation, probably through an impairment of the SPDEF transcription factor and its effect on goblet cells. This study, however, could be extended further. Given that hundreds of different chemicals are found in cigarette smoke, a relevant future direction for these researchers might be to assess which specific chemicals appear to primarily account for the deleterious effects of cigarette smoking as it relates to allergic asthma. It would also be interesting to see if any therapeutic measures could be taken to reverse some of the harmful effects caused by prenatal and/or postnatal secondhand smoking.
It is important to mention that the mechanisms which were seen at play in the aforementioned rodent model also probably play a role in human babies. Practically speaking, the researchers showed that although prenatal secondhand smoke appears to have the most harmful effects if it occurs prenatally as opposed to merely postnatally, damage by postnatal secondhand smoke is also serious. Conscientious parents must be careful not only to avoid smoking themselves, for the sake of their newborn or unborn children, but also to keep their children sheltered from secondhand smoke. If these measures are not taken, children may develop allergic asthma or a variety of other respiratory infections.
Primary Reference:
Singh, S. P., Gundavarapu, S., Pena-Philippides, J. C., Rir-Sima-Ah, J., Mishra, N. C., Wilder, J. A., . . . Sopori, M. L. 2011. Prenatal secondhand cigarette smoke promotes th2 polarization and impairs goblet cell differentiation and airway mucus formation. Journal of Immunology 187(9): 4542-4552.
Additional References:
Akinbami, L., Moorman, J., & Liu, X. 2011. Asthma prevalence, health care use, and mortality: United states, 2005-1009. National Health Statistics Reports. 32: 1-16.
Cates, E. C., R. Fattouh, J. R. Johnson, A. Llop-Guevara, and M. Jordana. 2007. Modeling responses to respiratory house dust mite exposure. Contrib. Microbiol. 14: 42–67.

Chen, G., T. R. Korfhagen, Y. Xu, J. Kitzmiller, S. E. Wert, Y. Maeda, A. Gregorieff, H. Clevers, and J. A. Whitsett. 2009. SPDEF is required for mouse pulmonary goblet cell differentiation and regulates a network of genes associated with mucus production. J. Clin. Invest. 119: 2914–2924.

DiFranza, J. R., C. A. Aligne, and M. Weitzman. 2004. Prenatal and postnatal environmental tobacco smoke exposure and children’s health. Pediatrics 113(4, Suppl.)1007–1015.

Holt, P. G., J. Rowe, M. Kusel, F. Parsons, E. M. Hollams, A. Bosco, K. McKenna, L. Subrata, N. de Klerk, M. Serralha, et al. 2010. Toward improved prediction of risk for atopy and asthma among preschoolers: a prospective cohort study. J. Allergy Clin. Immunol. 125: 653–659, 659, e1–e659, e7.

Kemp, K. L., S. D. Levin, P. J. Bryce, and P. L. Stein. 2010. Lck mediates Th2 differentiation through effects on T-bet and GATA-3. J. Immunol. 184: 4178–4184.
Phaybouth, V., S. Z. Wang, J. A. Hutt, J. D. McDonald, K. S. Harrod, and E. G. Barrett. 2006. Cigarette smoke suppresses Th1 cytokine production and increases RSV expression in a neonatal model. Am. J. Physiol. Lung Cell. Mol. Physiol. 290: L222–L231.
Singh, S. P., N. C. Mishra, J. Rir-Sima-Ah, M. Campen, V. Kurup, S. Razani-Boroujerdi, and M. L. Sopori. 2009. Maternal exposure to secondhand cigarette smoke primes the lung for induction of phosphodiesterase-4D5 isozyme and exacerbated Th2 responses: rolipram attenuates the airway hyperreactivity and muscarinic receptor expression but not lung inflammation and atopy. J. Immunol. 183: 2115–2121.

Wills-Karp, M., J. Luyimbazi, X. Xu, B. Schofield, T. Y. Neben, C. L. Karp, and D. D. Donaldson. 1998. Interleukin-13: central mediator of allergic asthma. Science 282: 2258–2261.

Yamashita, M., R. Shinnakasu, H. Asou, M. Kimura, A. Hasegawa, K. Hashimoto, N. Hatano, M. Ogata, and T. Nakayama. 2005. Ras-ERK MAPK cascade regulates GATA3 stability and Th2 differentiation through ubiquitinproteasome pathway. J. Biol. Chem. 280: 29409–29419.

Zhang, D. H., L. Cohn, P. Ray, K. Bottomly, and A. Ray. 1997. Transcription factor GATA-3 is differentially expressed in murine Th1 and Th2 cells and controls Th2-specific expression of the interleukin-5 gene. J. Biol. Chem. 272: 21597–21603.

Zhu, J., B. Min, J. Hu-Li, C. J. Watson, A. Grinberg, Q. Wang, N. Killeen, J. F. Urban, Jr., L. Guo, andW. E. Paul. 2004. Conditional deletion of Gata3 shows its essential function in T(H)1-T(H)2 responses. Nat. Immunol. 5: 1157–1165.


125 comments:

  1. A highly enlightening and well written piece. I know many people who smoke and it seems a shame that smoking be so prevalent despite research such as this that points to such negative effects of smoking, as well as in light of common sense. If not for ourselves, we certainly need to be aware of the effects of our bad habits upon future generations. Kudos on a well written article!

    ReplyDelete
  2. Cool article, Alana. Question: do they how second-hand smoking specifically affects mast cells? Just a thought. And another thought, I'll be sure to inform my future wife of these interesting findings.

    ReplyDelete
  3. I learned a lot from this article. Great job!

    ReplyDelete
  4. Nice article. It was very interesting.

    ReplyDelete
  5. Proud to say I quit in July. Still sucking on nicotine mints like I'm trying to get a part in a movie from them, but hey, progress. Smoking is hard on your body and offers so little in return! I'm glad that so many states have adopted clean air policies so public places stay smoke free. I sure wouldn't have wanted my mother to be in a smoke filled room day in day out while she was carrying me!

    ReplyDelete
  6. Great article and nicely written.

    ReplyDelete
  7. Wow, great article. I never made the association of second-hand smoking to asthma but now that I think about it this seems to make some sense. The research results showing impairment of mucus production is yet another reason to encourage quitting, for yourself, and for others (even for those yet to be born).

    ReplyDelete
  8. Very interesting-I'm also wondering, as you mentioned, about the possibility of retroactive therapeutic measures that can be taken by those exposed to second hand smoke. Would be such a step forward.

    ReplyDelete
  9. I had a concern about the ethics of these experiments involving animals. How exactly were these mice killed so that their tissue could be harvested?

    ReplyDelete
  10. This article certainly makes sense, although I had never thought of the link between secondhand smoking and asthma. I wonder if any studies have looked at the association of smoking and other specific respiratory infections (not just asthma). In any case, I am glad that people are taking the time to scientifically investigate these matters!

    ReplyDelete
  11. Great article. It was clear and well written. I learned a lot from it!

    ReplyDelete
  12. WOW... I knew second-hand smoke was bad for unborn babies, but there's so much I didn't know already... Awesome article!!

    ReplyDelete
  13. PS: Quit smoking 7 months ago, yey! It's possible to live without smoking... and this type of info helps me know I took the right choice and that my children's future will be better this way.

    ReplyDelete
  14. One question that came to my mind after reading this was whether these findings have been replicated using other allergens or if perhaps the observed results may be specific to A. fumigatus. Nevertheless, good job explaining the experiments!

    ReplyDelete
  15. Great explanation of the study. These certainly are some interesting findings pertaining to smoking. I wonder if research of this nature will prompt the US congress to enact nationwide federal smoking bans instead of allowing smoking laws to be determined on a state and local basis.

    ReplyDelete
  16. It makes me sad to think about how many people still smoke despite all of the data that demonstrates that they are not only hurting themselves, but also those around them. At least in the past individuals were not fully aware of the damage that smoking could cause. On another note, thanks for making the contents of this paper more accessible to a general audience! We need more blogs like this to raise awareness.

    ReplyDelete
  17. Mind blowing article. so much i didnt know. please remember me when you become a millionaire Alana.

    ReplyDelete
  18. Thank you for describing this study in understandable layman's English! I wonder what other transcription factors could be involved?

    ReplyDelete
  19. Information like this makes me happy that I no longer smoke even though it was extremely difficult to give up this habit once I had started it. Unfortunately, smoking is still very prevalent in certain cultures where it is not associated with a harsh cultural stigma. I certainly did not feel ostracized for smoking in Paraguay. On a happier note, last December President Lugo (of Paraguay) vetoed a law that would allow people to smoke in closed environments. Perhaps progress is being made.

    ReplyDelete
  20. As a guy that doesn't have any kids yet (thankfully) I wanted to know if smoking can also contribute to the development of asthma in adults. The paper you discussed only seemed to be looking the effects of secondhand smoke on very young mice.

    ReplyDelete
  21. Do you know if any studies have obtained similar results with lower amounts of smoke exposure? The proposed doses seem a little high although not altogether unrealistic.

    ReplyDelete
  22. Great job, Alana! This is really relevant for pregnant women. Are there any other things besides secondhand smoking that they should avoid in order to minimize their kids' chances of getting asthma?

    ReplyDelete
  23. The link between asthma and postnatal exposure to secondhand smoke seems to be an obvious one, but I would not have expected it to have a stronger connection to prenatal exposure. Who would've known?

    ReplyDelete
  24. An excellent article here! Well researched and very informative. I am curious if the pre-natal exposure to asthma is dependent on when the fetus is exposed like with fetal alcohol syndrome. For instance, is it more harmful to be exposed to second hand smoke in your first trimester than in other time points during pregnancy? It will be interesting to hear how pharmaceutical companies will potentially try to combat this health risk once the entire molecular pathway is mapped out.

    ReplyDelete
  25. This comment has been removed by the author.

    ReplyDelete
  26. Great article Alana! I understand why cigarette smoke is focused upon in most research regarding secondhand smoke, but I am curious if other types of smoke (cigar smoke, marijuana, etc) have any unique consequences for those who are exposed.

    ReplyDelete
  27. Alana, what a fascinating topic! Thanks for sharing it with me. I am interested to know, like Carolyn, why they chose to use the equivalent of 3 hours in a smoking bar for their standard of secondhand smoke exposure? Has anyone else used different amounts and obtained similar results? I wonder if it's dose-dependent!? Overall, a really wonderful job explaining everything! As someone who hasn't been reading much Neuro lately since I'm abroad, I was able to follow this easily (and it jogged my memory about some things I'd learned too!)

    ReplyDelete
  28. As if we needed more things to tell us second hand smoke is bad. But, this is really well written, interesting about the mice and all.

    ReplyDelete
  29. Very interesting article. Does post-natal exposure to secondhand cigarette smoke become progressively less risky with age or do the risks remain fairly constant at all post-natal stages?

    ReplyDelete
  30. I finally feel as if I can understand a scientific paper! Thank you for that. Also, you should consider blogging in Portuguese or Spanish so that other people can access this information. It is so difficult to find blogs like this one in other languages.

    ReplyDelete
  31. Great Article!
    It was nice to be able to read something on this topic and to actually understand what the author was talking about. I learned a lot.

    ReplyDelete
  32. Interesting article. It's definitely mind-boggling the percentage of people who suffer from respiratory problems. More smokers should read your article to know how much harm they may be causing themselves and others, especially children or even unborn babies.

    ReplyDelete
  33. This was a very informative read but as stated above by egn56 I am concerned with the treatment of the mice.

    ReplyDelete
  34. I was wondering, how exactly was the airway resistance measured in the mice? It sounds quite complicated and painful. Overall, a very informative and intriguing article!

    ReplyDelete
  35. Interesting article. What brand of of cigarettes did use? Also would there be a difference in the experiment if using different brands?

    ReplyDelete
  36. As mentioned in a comment or two above it would be interesting to see this study done with different types of smoke to see if the results differ.

    ReplyDelete
  37. I can actually relate to this article as I have family members that have smoked for years, maybe I will show them this.

    ReplyDelete
  38. most of these studies seemed to be focused on the lungs and cells within the lungs. Can asthma also affect more distant tissues in the body and stimulate immune responses in other locations?

    ReplyDelete
  39. Nice article. Seems like something new is being discovered about smoking everyday, most of it bad.

    ReplyDelete
  40. This is certainly a hidden danger, and speaks volumes to the necessity of sheltering both mothers-to-be and their children from this damaging poison. A very well-written and sound argument, a resounding, scientific call-to-arms to those out there who are either negligent or unaware. Having several friends with asthma, its important to understand at least one step that can be taken to alleviate some of the risk.

    ReplyDelete
  41. my parents always complain about my respiratory problems... now we know whose fault it is

    ReplyDelete
  42. This is a great article, Alana! Very informative. I think you did a great job bringing scientific research into the real world. While we all know smoking has bad health effects on the smokers, it's definitely interesting to see the effect on other people as well, especially for pregnant women. Well done!

    ReplyDelete
  43. Really informative article. My dad smokes a lot, and I've been trying to get him to quit for a while, maybe this will be the tipping point for him.

    ReplyDelete
  44. Great article! I'll show this to my dad who quit smoking years ago but has asthmatic symptoms.

    ReplyDelete
  45. I like this post. I can now add more information to my I-hate-cigarettes knowledge bank.

    ReplyDelete
  46. This is really interesting! You do a good job explaining the specifics of how the common problem of secondhand smoke can cause such a widespread disease. I'm curious as to what some other causes of asthma might be. I think secondhand smoke exposure probably explains a lot of asthma cases but I wonder what other factors might cause it. Overall great article!

    ReplyDelete
  47. Informative and well-written. Great article.

    ReplyDelete
  48. Makes perfect sense! Got some cousins with asthma and I know for sure that his parents smoked.

    One thing I am skeptical is the exposure time, it seems too much to me. Because I don't think a pregnant woman would spend 3 hours per day in a smoking bar. So it seems irrational to use the equivalent of this on the rats. (poor rats) :P

    But good job!

    ReplyDelete
  49. Really excellent job conveying the findings of the paper! You said the researchers exposed the mice to each condition for the same length of time seven days a week. Do you believe there would be any differences if the animals were exposed to the same level of smoke for the week but in a more variable fashion (i.e. 8 hrs. one day,4 hrs. the next, etc)?

    ReplyDelete
  50. So many questions! This is great. I'll try to answer them, but please be patient!

    Claire: I actually don't know if there would be any differences. I imagine, however, that some variability would be seen (either a stronger or weaker response) depending on how lengthy each exposure time was. That's an interesting question though because under normal conditions, a person would not necessarily be exposed to such normally spaced encounters with SS.

    Roberto and Carolyn: Yes, it seems a bit lengthy to me too but imagine if a pregnant woman's spouse was a smoker. Then the levels become a lot more plausible (and yes, many husbands still smoke even if their wives are pregnant).

    Allison: There are many different risk factors that are associated to childhood asthma. Genetics and gender (boys suffer from asthma more commonly than girls) are only two of these risk factors.

    Angela: They didn't use commercially available cigarettes but "research cigarettes" purchased from a Tobacco and Health Research Institute. It would be interesting to analyze how these cigarettes compare to normal cigarettes.

    Dan and egn56: The mice were anesthetized before they were killed. Anesthesia is routinely used in research of this type. These studies have to be approved by review boards before they are undertaken so that excessive animal cruelty does not take place.

    Joao: Good suggestion. Maybe I can translate some of these in my spare time. My parents also constantly complain about the fact that they have never been able to read the papers that I write because they are typically in English, haha.

    ReplyDelete
  51. I honestly didn't know much about asthma before reading this blog, even though I had heard about it. Besides the use of inhalers, how do doctors treat this disease?

    ReplyDelete
  52. Very interesting article that conveyed the information very clearly-well done. It's so important to remember how the outside world affects the fetus while it is in utero!

    ReplyDelete
  53. I thought that asthma was just one single disease and I did not know that there could be different types. What other kinds of asthma exist other than allergic asthma?

    ReplyDelete
  54. Fascinating study Alana! It seems like it took so much time and effort. Just out of curiosity, how much would an experiment like this cost and who funds this kind of research?

    ReplyDelete
  55. This article presents a good scientifically based argument on why cigarettes should be illegal. Smoking not only causes harm to the person doing it but to others who have never picked up a cigarette ever. Thank you for writing this piece and I hope it goes Viral.

    ReplyDelete
  56. First of all,
    I can see the depths of your research and I give you high credits. Although there is one thing that I am not quite understanding.

    As you said in the first paragraph,
    "The specific contributions of exposure to smoke that is either prenatal (before birth) or early postnatal (after birth) in the development of allergic asthma, however, is not WELL UNDERSTOOD."

    And the 6th paragraph,
    "Mucus formation, however, CAN BE impaired in diseases such as asthma."

    I might say that this research is ongoing?
    As I assume,there is no concrete evidence of cigarette smokes causing asthma. Am I correct? (please correct me if I am wrong)

    So my question is, is your intention of writing this article to prevent people from smoking during the early pregnancy and post pregnancy, or just to state a scientific research?

    because if it is for prevention of smoking relating to your studies, I think it would be better if the correlation of cigarettes and asthma is fully proved.

    But if it is to state your scientific research, I think it is an excellent research.

    And Alana, If this research is fully proved,I think it could be a big contribution to prove that smoking does harm people.

    Thank you for giving me a chance to see what people do in other fields of studies.

    ReplyDelete
  57. This comment has been removed by the author.

    ReplyDelete
  58. Excellent Work!
    Your research will truly help people notice the harm that cigarettes can cause

    ReplyDelete
  59. I agree with Yeva. This adds great ammunition to my argument against smoking. Great job!

    ReplyDelete
  60. Fantastic work. Very interesting and clearly well-researched.

    ReplyDelete
  61. very good work, u manage to give complete information about the subject but still kept it simple

    ReplyDelete
  62. Nice work. Concise and well-argumented.

    ReplyDelete
  63. Do you know if the incidence of asthma varies depending on the geographical region? I want to know what the stats for Paraguay and Ecuador are...

    ReplyDelete
  64. Great work Alana! I can't help but wonder what the effects of prenatal secondhand smoke exposure are at different stages of gestation. I wonder what kind of effects would be seen if pregnant mice were only exposed to SS at early stages of pregnancy, mimicking perhaps a woman being exposed to SS during a time when she did not yet realize that she was pregnant. Frightening to think about certainly! I think it's great that you're doing your part to get this information out there. Once again, nice job.

    ReplyDelete
  65. Interesting article Alana! I wonder if a woman who smokes or lives with a smoker her entire life prior to pregnancy would have similar symptoms during pregnancy? Or if the results change with a second or third pregnancy.

    ReplyDelete
  66. I was diagnosed w childhood asthma but there is a very high correlation with it actually being sarcoidosis in many demographics. Some of the asthma type parameters coincide with autoimmune disorders which is an interesting spin as well.

    ReplyDelete
  67. That's the first time I've read something that explained how a substance can be directed against specifically cancerous material. I knew that it was done, or at least attempted, but actual mechanisms were mysterious. Thanks for that.

    On a larger scale, this seems rather important. I don't have the scientific background to do a rigorous evaluation, but my distinct impression is that this is a significant finding.

    ReplyDelete
  68. Great Work Alana!
    This article is very informative and accessible. I learned a lot from it about a topic that I feel like I should know more about coming from a family of ashmatics!

    ReplyDelete
  69. Great article! Learned a lot reading it.. Really good choice of an article. How long did it take the researchers to collect all this data though? It seems labour-intensive. Hope to read more articles of this kind! Impresive!

    ReplyDelete
  70. Wow, great description of the research. Out of personal curiosity, I was wondering how many different types of allergens can trigger allergic asthmatic responses in humans? Is it just one allergen or are there many?

    ReplyDelete
  71. Nice article Alana! Very educational and good to know for later on in life.

    ReplyDelete
  72. What a wonderful, well written article. I'm forwarding this link to a pregnant friend of mine whose husband smokes; she's been trying to get him to quit for a while now, and this could be the leverage she needs. I love the photo that accompanies this article, and I especially like how convenient the links are for the terms I didn't understand (I'm not a medical person). Nicely written! Great job, Alana!

    ReplyDelete
  73. Very Well written. Sadly, this point cannot be stressed enough.

    ReplyDelete
  74. This article is very well written and interesting!!

    ReplyDelete
  75. Very interesting Alana! Well written. Good description. You made it easy for us non-medical people to understand the reason why pregnant women should not be around smoke. I especially think it is interesting that being around cigarette smoke can cause a person to have less mucus in lungs, which then makes it harder to fight off pathogens.

    ReplyDelete
  76. Nice article! unfortunately thats what happened to one of my friends

    ReplyDelete
  77. Nice job! Very informative and carefully explained

    ReplyDelete
  78. Are mice really that great of a model for humans? Wouldn't chimpanzees or apes be better research animals?

    ReplyDelete
  79. This has completely changed my outlook on smoking. I second Macauley's questions. I've always been ok with hanging out with people who smoke, but I wonder whether my actions right now will affect my children in the future, even if I make a conscious effort to avoid smokers during my pregnancy.

    This brings up a concern along a different vein. Nowadays, it seems so much effort is put into finding cures or vaccines to diseases like malaria or HIV; problems that are more high-profile and thereby more likely to bring the researcher acclaim. However, "little" issues like the one you have presented in this post are so much more prevalent in--and applicable to--our daily lives. My question is, then, what percentage of budding researchers opt to go into research like this that is more low-profile. I do realize there is a more pressing, global need for research into HIV or vaccine, but I would certainly hate to see the more (relatively) mundane problems be pushed aside as a consequence...

    ReplyDelete
  80. Intriguing article. This demonstrates why I choose to major in Economics.

    While I did know that second hand smoke had horrible effects, I did not know how much it could impact babies after they were born.

    Great work!

    ReplyDelete
  81. Wow. You really found a recent article! I'm glad that you can explain all of this technical information so clearly. You seem to have picked the right major. Also, to address the Clueless person abovee me, mice do have a lot of genetic similarity with humans and are easier and cheaper to maintain and breed than primates.

    ReplyDelete
  82. This article was very well written and really informative, I've been a smoker for the past 5 years but this is going to push me in right direction to start making efforts to quit.

    ReplyDelete
  83. Best article I've read in a long time.

    ReplyDelete
  84. Interesting stuff. I'm not sure there is enough evidence to extend the findings to humans and say that the chemicals in cigarettes would affect human fetuses the same way, but it's definitely a surprise that prenatal exposure is more damaging than postnatal, at least in contributing to the possibility of developing asthma

    ReplyDelete
  85. interesting! learned something...

    ReplyDelete
  86. Nice article, I can't imagine why people would still smoke close to pregnant women after this!

    ReplyDelete
  87. Very informative!

    ReplyDelete
  88. This is such a creative experiment! I would never have thought of studying asthma like this.

    ReplyDelete
  89. Did the authors of this paper think about doing further studies involving the effects of second hand smoke to prenatal or postnatal children with respect to lung cancer?

    ReplyDelete
  90. Very interesting topic! Interesting article

    ReplyDelete
  91. I'm glad that people out there are doing this kind of research. Somebody has to. Have you ever done these kinds of experiments before Alana?

    ReplyDelete
  92. Great article and interesting study. I hope people realize how detrimental smoking is to kids.

    ReplyDelete
  93. this is such an interesting article! great summary and very informative

    ReplyDelete
  94. Good job alana!

    ReplyDelete
  95. Thanks Alana for showing me this informative article; it brings up a whole host of pertinent, and disturbing questions! I wonder what a follow up study isolating the effects of the various chemicals in cigarettes as well as the effects of cigarette smoke exposure during different stages of gestation... yikes!

    ReplyDelete
  96. I've always wondered about that... Thats awesome.

    ReplyDelete
  97. Hey Alana. Very informative article. Question: does it matter what kind of mice are used in the experiment? If it was a different type of mouse would the results be the same?

    ReplyDelete
  98. This is such an important study. Does it clearly coorelate to the side effects you would see in humans? If so there should be more of an effort to inform expecting families. Poor rats!

    ReplyDelete
  99. How does PETA feel about this cruelty to animals?

    ReplyDelete
  100. absolutely absurd that smoking has anything but positive consequences on your health

    ReplyDelete
  101. I'm part of that 8% with asthma, and while I obviously wasn't around to know if my mom was around any smokers before my birth, I remember as I was growing up that if I was ever around someone who was smoking, I would start coughing and it would cause my asthma to flare up. Even now, as I've mostly grown out of it, being around smoke will agitate my lungs and cause coughing. It doesn't immediately cause wheezing, but there is still some agitation there.

    This was very well written, and I wish more smokers could read something like this to see the effects their habit has on the world around them.

    ReplyDelete
  102. Nice Alana. Do you think the results would be about the same if the baby mice in the experiment were exposed to different types of smoke as well? Like how about pot smoke?

    ReplyDelete
  103. @Anonymous PETA agent: Would you rather they use real babies instead of mice?

    ReplyDelete
  104. @Dani Henkle And it's sad how we know so many people that smoke, but as much as we encourage them to quit, it really is influenced by society. For some reason, paying to carry a burning twig in your mouth and inhaling the harmful smoke is cool and accepted because you can do it with friends, it can be a calming activity and habits can be hard to quit. I know I'm simplifying, but I feel bad for my friends with this bad habit. I wish I knew an easier way for them to quit, but reality is, a habit is a habit and they have to choose for themselves.
    And a ps. sucking face with an ashtray- not cool.

    ReplyDelete
  105. This was very informative and well written!

    ReplyDelete
  106. @shanebrentster I guess next time I get high I'll grab some mice and see what happens...

    ReplyDelete
  107. First of all I really wanted to read all of this article but its incredibly too dense. Next time don't just copy and paste your paper you wrote for a class and call it a blog.

    Secondly, why do people constantly vilify just smoking everyone has their release we just choose certain ones and attack them without mercy. Did you know if the mother is stressed it can also lead to asthma? Its 2011 leave smokers alone they know the risks they dont care and they are smoking to deal with the stress of the constant harassment of people like you

    ReplyDelete
  108. @David P So in other words, your wife will be the pregnant idiot at the bar for 3 hours a day? GL with your kids with asthma.

    ReplyDelete
  109. @David P And of course, being well read and having actually read through the whole article, even if you don't understand it all, that wouldn't be a good idea before posting on someone's well written blog?

    ReplyDelete
  110. I didn't say I smoked. Nor will I probably ever smoke, I have my own vices and I am sure they are unhealthy for me in some way. They also are harmful to other people in some other way. So why focus on smoking? Are people going to read this article and go IT COULD BE LINKED TO ASTHMA TOO!? Well now I must certainly stop!

    ReplyDelete
  111. They're modeling secondhand smoke from spending 3 hours/day in a smoking bar. I doubt few pregnant women spend this much time in a bar--are there plans to investigate lower doses of smoke exposure?

    ReplyDelete
  112. Yet do you realize that you are likely exposed to smokers and second hand smoke on a constant basis. Your kids, heaven forbid you have any, might likely be exposed to the toxins that can be linked to asthma themselves. Yours is a selfish but common perspective.

    ReplyDelete
  113. I used to have really bad asthma, now I don't. Do you know who else did that? Teddy Roosevelt. Besides which is worse smoking around a pregnant woman? Or losing all the money that she needs to take care of the kid gambling?

    ReplyDelete
  114. Teddy also beat polio, you're not on that level, I assure you. So now our pregnant mother in the scenario gambles? Do you really think you're being reasonable with this scenario, or in general? You think that "really bad asthma" just goes away?

    ReplyDelete
  115. I guess more on point is what is this article aiming to do? Is it trying to convince smokers to stop? Is it aiming to make people feel better about not smoking fulfilling some self righteous masturbatory want? Or did some girls professor tell them to post their papers online?

    ReplyDelete
  116. Great article on an important topic! This will definitely help raise awareness for the effects of secondhand smoking on babies.

    ReplyDelete
  117. alana... absolutely absurd that smoking has anything but positive consequences to your health

    ReplyDelete
  118. Very informative paper. Do you know why some people grow out of their asthma while others don't? it might a good follow up if that interests you.

    ReplyDelete
  119. As a person with asthma, I enjoyed learning a little more about what are the physiological effects of asthma and what they mean. good job

    ReplyDelete
  120. You said that boys suffer from asthma more commonly than girls. Why is this the case?

    ReplyDelete
  121. I'll try to answer some of these questions in my free time.

    Ciera - There are many kinds of asthma, such as exercise induced asthma. For a complete list you can follow this link: http://www.webmd.com/asthma/guide/types-asthma

    Alice - A wide variety of medication is used for the treatment of asthma. Many of them are used to relax a person's airways. If you're interested in this topic, follow this link for a discussion of specific medications: http://www.mayoclinic.com/health/asthma/DS00021/DSECTION=treatments-and-drugs

    I'll post more answers to the aforementioned questions in the near future :)

    ReplyDelete
  122. Cool study! I knew about the symptoms of asthma but not about the mechanisms that explained them.

    ReplyDelete