User:Aidan Canil/sandbox

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 * Note: Please use your sandbox to submit assignment # 3 by pasting it below. When uploading your improvements to the article talk page please share your exact proposed edit (not the full assignment 3).


 * Talk Page Template: CARL Medical Editing Initiative/Fall 2019/Talk Page Template

=Noonan Syndrome=

Assignment 2
Aidan Canil

Atwal, P. Noonan Syndrome. Dynamed. August 2019. https://www.dynamed.com/topics/dmp~AN~T1555433374201. Last accessed 5 Nov 2019.

1) How you searched for a source (search strategy – where you went to find it).

Typed “Noonan Syndrome” into the Trip database and then filtered based on secondary evidence only and guidelines from within the last 5 years to comply with the MEDRS criteria.

2) What potential sources were identified and considered (give examples of 1 or 2).

Zenker M: Genetic and Pathogenetic Aspects of Noonan Syndrome and Related Disorders. Horm Res 2009;72(suppl 2):57-63. doi: 10.1159/000243782

3) Why the source was chosen (what made it better than other choices).

My source was chosen over the other options due to its more recent nature. The other options were from 10 years ago, and it is likely that in the intervening time, our knowledge about the disease has evolved and become more robust.

4) List at least three reasons why the source that was selected meets Wikipedia’s reliable medical sources (MEDRS) criteria.

The source contains current information that has been published in the last 5 years and is presented in a non-biased way. Many different sub-sources of information are synthesized to create the practice guidelines contained in my selected source. Clinical practice guidelines are also listed as one of the most credible sources of information based on the MEDRS criteria page.

5) How do you plan to use the source for improving the article?

I plan on expanding on the currently very limited prognosis section of the article, in order to give readers more detailed information what the expected outcomes are for individuals living with Noonan Syndrome.

Assignment 3
Proposed Changes


 * 1) I will be addressing the following sentence currently included in the prognosis section: "The mean final heights were 167 and 153 cm for men and women, respectively, which is about 2 standard deviations below normal." Additionally, I will be adding new information to the prognosis section and rearranging the sentence format to make the article flow better in that section. The new introduction to the prognosis section will be as follows:
 * 2) * Noonan syndrome does not seem to impair an individual’s overall quality of life . The majority of those with Noonan syndrome can expect to lead normal lives, however periodic follow up and lifelong monitoring of abnormalities found in any system, especially the cardiovascular system, is recommended . The final adult height of individuals with Noonan syndrome is about 161-167cm in males and 150-155cm in females, which approaches the lower limit of normal.

Rationale for proposed change


 * 1) Currently the article does not include any general overview of the prognosis for Noonan Syndrome. It is important for those who may have been diagnosed with the syndrome, or who have family with the syndrome to be able to look up and see in broad terms how their, or their loved ones lives will be affected. I added the additional sentences to allow for a quick outline of how seriously Noonan Syndrome will impact an individual's life.
 * 2) For the specific selected sentence currently in the article, it cites a primary research study which does not comply with wikipedia guidelines, so I selected a new secondary literature source. I also wanted to make the sentence flow more naturally within the framework of the soon to be overhauled prognosis section, and less like an isolated fact.
 * 3) Across the literature there was little to no controversy about the prognosis for Noonan Syndrome, as the medical outcomes are widely accepted and in agreement with one another. Based on this consensus I decided to move ahead with my proposed changes.

Critique of Source

The Dynamed source used to describe the quality of life and overall outcomes of those living with Noonan Syndrome, only draws it claims off of 2 small scale studies. One of the studies only had 10 participants which is such a small sample size, that it is difficult to be fully confident that the results reported are truly indicative of the overall population living with Noonan Syndrome. Additionally, quality of life is a more subject marker than a clear pathology such as pulmonary stenosis. That being said I still think it is important to include so that individuals without any medical knowledge can quickly gauge the relative impact of the disease on life, even if it may not be incredibly well defined. No conflicts of interest were declared and no other red flags for practice guidelines were present. Looking at the standards for a trustworthy guideline, the article was not written by a multidisciplinary panel, nor rated the level of evidence for each of the management recommendations or prognoses, which could be a source of bias. There is however, a revision system for new information should it arise, and the source was updated August 2019, which does increase its credibility as an up to date source of information. The articles cited within the source were also only in the English language, which could have led bias since foreign language studies would not have been included.

= Syntrophy = Syntrophy, synthrophy, cross-feeding, or cross feeding [Greek syn meaning together, trophe meaning nourishment] is the phenomenon that one species lives off the products of another species. In this association, the growth of one partner is improved, or depends on the nutrients, growth factors or substrate provided by the other partner. Jan Dolfing described syntrophy as "the critical interdependency between producer and consumer". This term for nutritional interdependence is often used in microbiology to describe this symbiotic relationship between bacterial species. Morris et al. have described the process as "obligately mutualistic metabolism".

Microbial Syntrophy
Syntrophy plays an important role in a large number of microbial processes.

The defining feature of ruminants, such as cows and goats, is a stomach called a rumen. The rumen contains billions of microbes, many of which are syntrophic. One excellent example of this syntrophy is interspecies hydrogen transfer. Some anaerobic fermenting microbes in the rumen (and other gastrointestinal tracts) are capable of degrading organic matter to short chain fatty acids, and hydrogen. The accumulating hydrogen inhibits the microbe's ability to continue degrading organic matter, but syntrophic hydrogen-consuming microbes allow continued growth by metabolizing the waste products. In addition, fermentative bacteria gain maximum energy yield when protons are used as electron acceptor with concurrent H2 production. Hydrogen-consuming organisms include methanogens, sulfate-reducers, acetogens, and others. Some fermentation products, such as fatty acids longer than two carbon atoms, alcohols longer than one carbon atom, and branched-chain and aromatic fatty acids, cannot directly be used in methanogenesis. In acetogenesis process, these products are oxidized to acetate and H2 by obligated proton reducing bacteria in syntrophic relationship with methanogenic archaea as low H2 partial pressure is essential for acetogenic reactions to be thermodynamically favorable (ΔG < 0). (Stams et al., 2005)

The number of bacterial cells that live on or in the human body, for example throughout the alimentary canal and on the skin, is in the region of 10 times the total number of human cells in it. These microbes are vital, for instance for the digestive and the immune system to function.

Another example is the many organisms that feed on faeces or dung. A cow diet consists mainly of grass, the cellulose of which is transformed into lipids by micro-organisms in the cow's large intestine. These micro-organisms cannot use the lipids because of lack of oxygen in the intestine, so the cow does not take up all lipids produced. When the processed grass leaves the intestine as dung and comes into open air, many organisms, such as the dung beetle, feed on it.

Yet another example is the community of micro-organisms in soil that live off leaf litter. Leaves typically last one year and are then replaced by new ones. These micro-organisms mineralize the discarded leaves and release nutrients that are taken up by the plant. Such relationships are called reciprocal syntrophy because the plant lives off the products of micro-organisms. Many symbiotic relationships are based on syntrophy.

Biodegradation of Pollutants
Syntrophic microbial food webs can play an integral role in the breakdown of organic pollutants such as oils, aromatic compounds, and amino acids.

Environmental contamination with oil is of high ecological importance, but can be mediated through syntrophic degradation. Alkanes are hydrocarbon chains that are the major chemical component of crude oils, and have been experimentally verified to be broken down by syntrophic microbial food webs. The hydrocarbons of the oil are broken down after activation by fumarate, a chemical compound that is regenerated by other microorganisms. Without regeneration, the microbes degrading the oil would eventually run out of fumarate and the process would cease. This breakdown is crucial in the processes of bioremediation and global carbon cycling.

Syntrophic microbial communities are key players in the breakdown of aromatic compounds, which are common pollutants. The degradation of aromatic benzoate to methane produces many intermediate compounds such as formate, acetate, CO2 and H2. The build up of these products makes benzoate degradation progressively less favourable. These intermediates can then be taken up and metabolized syntrophically by methanogens to make the whole process more thermodynamically favourable.

Studies have shown that bacterial degradation of amino acids can be significantly enhanced through the process of syntrophy. Microbes growing poorly on amino acid substrates alanine, aspartate, serine, leucine, valine, and glycine can have their rate of growth dramatically increased by syntrophic H2 scavengers. These scavengers, like Methanospirillum and Acetobacterium, metabolize the H2 waste produced during amino acid breakdown, preventing a toxic build-up. Another way to improve amino acid breakdown is through interspecies electron transfer mediated by formate. Species like Desulfovibrio employ this method.

Aidan Canil (talk) 02:16, 6 October 2017 (UTC)