Sickle cell anemia is a very well-known blood disorder that affects around 20 million people worldwide, making it a relatively rare disease, however, why does it occur? This is a very interesting topic that covers the big picture of the inheritance of genetic diseases and why it occurs! In this blog, we will be examining the mechanisms by which sickle cell disease occurs and examining why they lead to the pain people with this disease experience.

“Sickle cell disease”, or SCD is an umbrella term for inherited blood disorders concerning the protein hemoglobin. (cdc.gov) Sickle cell anemia is the most severe form of this disease (HbSS or SCA), containing an abnormal form of hemoglobin, labeled as hemoglobin “S”. This mutation is carried by both parents, increasing the severity of the parent disease and bringing forth the notorious “sickle” shape and rigidity to the red blood cells that are at the root of most complications affiliated with the disease. Some of these complications people with SCA face include episodes of chronic pain, delayed growth, vision problems, and a weakened immune system due to the constant blockage of blood flow in the vessels from the mutated cells.  

Sickle cell anemia falls under the category of autosomal recessive diseases, meaning both parents are carriers (also known as heterozygous and noted with an “Ss” genotype) for a specific disease and give their offspring a twenty-five percent chance of obtaining its recessive gene. The genetic nature of this disease is what causes the abnormality to begin with. If an offspring contained this recessive gene, it would be found on chromosome 11 p15.5, which includes hereditary diseases caused by abnormal or insufficient production of hemoglobin. This aligns with the abnormal property that SCA hemoglobin has, validating its location in that specific chromosome. 

The structure of the hemoglobin molecule includes two globin alpha chains and two globin beta chains, each containing around 150 amino acids for a total of about 600 in one molecule. During the process of protein synthesis, the base sequence of codon six, normally “GAG” in a non-mutated gene, would code for the hydrophilic glutamic acid as an amino acid. However, the hereditary mutation from the recessive “ss” gene means that there would forever be a substitution of the base thymine in place of adenine, coding “GTG”, or valine instead. This in turn causes a single point mutation and change in the sequence of the beta chains that directly correspond to the oxygen-carrying property of hemoglobin. 

Although the nitrogenous base substitution only affected two out of the six hundred amino acids, the change in functional groups from the polar glutamic acid to nonpolar valine caused not only structural, but functional changes in the hemoglobin protein. This change in the beta chains disrupts the sequence of amino acids and causes the hemoglobin molecule to misfold and assemble into long, rod-like fibers that cannot adequately hold the same amount of oxygen as a regular, disk-shaped red blood cell. As a result, the hemoglobin is not able to perform its job in transferring oxygen throughout the body to the same extent, as it tends to clog arteries and blood flow while moving from one area to another as opposed to flexibly and effortlessly doing so.  

In an attempt to compensate for the abnormality seen in the sickle cells, the frequency, demand, and amount of proteins focused on cell repairs increases. Examples include antibodies, which work to fight off the more recurring and severe illnesses due to damaged spleen, structural proteins focused on maintaining the cytoskeleton of the cell, and glycolytic enzymes focused on the production of ATP in an environment with minimal oxygen and constant cell death (anemia).

Using this new knowledge of abnormal hemoglobin, it can be determined that the majority of symptoms, for example, chronic pain, vision problems, delayed growth, and a weakened immune system, are due to the rod-like shape of the misfolded protein: blocking important arteries and impairing organs and oxygen storage.

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Sources:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3882043/

https://www.mayoclinic.org/diseases-conditions/sickle-cell-anemia/symptoms-causes/syc-20355876 

https://www.mayoclinic.org/autosomal-recessive-inheritance-pattern/img-20007457#:~:text=To%20have%20an%20autosomal%20recessive,dominant%20gene)%20for%20the%20condition. 

https://www.cdc.gov/ncbddd/sicklecell/facts.html 

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8006275/#:~:text=Red%20cells%20have%20an%20average,from%20the%20circulation%20every%20second.  

https://www.cancer.gov/publications/dictionaries/cancer-terms/def/hemoglobin  

https://www.khanacademy.org/science/biology/macromolecules/proteins-and-amino-acids/a/orders-of-protein-structure 

https://www.ncbi.nlm.nih.gov/books/NBK22238/#:~:text=SCA%20is%20an%20autosomal%20recessive,5. 

https://www.genome.gov/Genetic-Disorders/Sickle-Cell-Disease 

https://www.nih.gov/news-events/nih-research-matters/fixing-sickle-cell-disease-gene 

https://www.mayoclinic.org/autosomal-recessive-inheritance-pattern/img-20007457#:~:text=To%20have%20an%20autosomal%20recessive,dominant%20gene)%20for%20the%20condition. 

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5381778/#:~:text=Mutations%20in%20the%20HBB%20gene%2C%20which%20is%20located%20on%20chromosome,cell%20anemia%20and%20%CE%B2%2Dthalassemia. 

https://pubmed.ncbi.nlm.nih.gov/25282490/#:~:text=Sickle%20cell%20disease%20is%20associated,is%20replaced%20by%20valine%2C%20hydrophobic. 

https://dnalc.cshl.edu/view/15968-What-causes-sickle-cell-.html#:~:text=The%20beta%20globin%20protein%20is,behavior%20of%20red%20blood%20cells. 

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3068560/ 

It’s finally the wonderful season of winter! I may be biased, but nothing is better than looking outside and seeing everything beautifully covered in white! In the past few years we have received less snow than on average, however, will that change this winter? 

One way we can determine a general trend of snowfall is through two opposing climate patterns, La Niña and El Niño. These are patterns under the umbrella of ENSO that affect ocean temperatures, wind patterns, rainfall, and surface pressure (climate.gov) across the globe and that break the normal condition of upwelling: where deep cold water rises to the surface, replacing water pushed away by the winds. An El Niño occurs when the easterly trade winds across the Pacific weaken, ocean temperatures in the Pacific rise, and rainfall decreases over Indonesia and increases across the Pacific. Relating to this, the rising air motion increases, and this specific increase in Indonesia leads to higher surface pressure and dryness. Considering this information, what is a La Niña and how is it different compared to an El Niño? 

La Niña is the opposite of El Niño: during this climate pattern, the surface winds across the Pacific are stronger, ocean temperatures in the Pacific are cooler and warmer near Indonesia, and rainfall increases over Indonesia and decreases over the Pacific. Additionally, there is more sinking air motion over the Pacific and more rising air motion, and lower surface pressure in Indonesia. We have been in La Niña for the past 3 years and are finally beginning to shift into the El Niño phase.

But how does this relate to predicted snowfall? 

First, it’s important to note that although certain climate patterns can raise or lower the odds for snow in certain regions, they never ensure their occurrence. This pattern generally brings cooler and wetter weather to the southern part of the United States, while the northern part experiences drier and warmer conditions. During an El Niño, a jet stream carries moisture and precipitation across the southern part of the United States. This generally increases the chances of snowfall over the southern part of the country, while also decreasing these chances in the northern part of the North American continent. The map below depicts the expected snowfall for January to March of 2024, where the blue regions represent wetter and snowier predicted areas and the tan regions represent drier regions. 

Overall, multiple factors other than climate conditions can affect predicted snowfall and these predictions may stray from reality, but since we are entering what will be a moderate-to-strong El Niño, we can most likely expect stronger El Niño-like patterns, meaning more snow for the southern United States, and less snow for the northern portion!

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Sources:

https://www.cnn.com/2023/11/03/weather/us-snowfall-maps-el-nino-winter-climate/index.html#:~:text=This%20pattern%20comes%20from%20the,more%20amplified%20its%20impact%20becomes. 

https://www.climate.gov/news-features/blogs/snow-pain-snow-gain-how-does-el-nino-affect-snowfall-over-north-america 

https://www.climate.gov/news-features/understanding-climate/el-ni%C3%B1o-and-la-ni%C3%B1a-frequently-asked-questions 

https://www.climatecentral.org/climate-matters/local-and-global-effects-of-el-nino-and-la-nina-2023 

https://www.nationalgeographic.com/environment/article/el-nino-la-nina#:~:text=While%20El%20Ni%C3%B1o%20raises%20the,how%20they%20influence%20our%20weather.

Most people have probably already heard of Attention Deficit Hyperactivity Disorder or ADHD, but, how many people know what someone with ADHD experiences? This blog will be a little different from others I have done, where I will share some of my experiences as someone diagnosed with ADHD. 

Just as some basic background, the Mayo Clinic defines ADHD as “… a combination of persistent problems, such as difficulty sustaining attention, hyperactivity and impulsive behavior.” It is associated with low levels of neurotransmitters transmitting between the prefrontal cortex area and basal ganglia, in this case, the neurotransmitters dopamine and noradrenaline which are associated with regulating the reward system, mood, and attention. These low dopamine levels call for individuals with ADHD to seek out rewards to overcome this deficiency. There are various levels of severity to this neurodevelopmental condition, however, generally, symptoms start and can be recognized from ages 3 to 12 and can continue into adulthood. 3 types of ADHD presentation can affect the specific symptoms of this disorder. Those being predominantly inattentive, predominantly hyperactive-impulsive, or combined. 

Predominantly inattentive individuals find it more difficult to finish tasks, focus attention, or follow regular conversation. These individuals generally are more inattentive to the world around them. Predominantly hyperactive-impulsive individuals are constantly fidgeting, talk excessively, and are impulsive towards everything around them. Finally, combined is a combination of the two presentations, where symptoms are spread relatively equally indicating either presentation. Overall, having any form of ADHD is a hindrance to everyday tasks that make life more difficult than it should be.

As someone with inattentive type ADHD, I had shown signs of inattention ever since I was little which hinted to my ADHD early on. I have trouble focusing on one task for an extended time, I take longer to process information, I have trouble finishing tasks on time, staying on top of my workload, and sometimes zone out when others are talking to me, and more. I love learning, which is why I decided to go to college and pursue my interest in studying medicine, however, having ADHD constantly feels like a rope tugging me away from the goals I know I can achieve. The experience of ADHD is often misconstrued, and many people will deny its existence or claim it’s just “laziness”. This is far from the truth as ADHD has had a biological basis for decades before medication was even created for it.

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Sources:

https://www.cdc.gov/ncbddd/adhd/facts.html 

https://www.psychologytoday.com/us/blog/balanced/202302/why-is-the-prevalence-of-adhd-increasing 

https://www.mayoclinic.org/diseases-conditions/adhd/symptoms-causes/syc-20350889?utm_source=Google&utm_medium=abstract&utm_content=Attention-deficit-hyperactivity-disorder&utm_campaign=Knowledge-panel 

https://www.nimh.nih.gov/health/publications/adhd-what-you-need-to-know 

https://www.healthline.com/health/adhd/inattentive-type#behavioral-therapy 

https://www.webmd.com/add-adhd/childhood-adhd/features/hyperactivity-reality-or-excuse#:~:text=While%20there’s%20sometimes%20a%20grain,anything%2C%20ADHD%20is%20often%20underdiagnosed. 

https://www.news-medical.net/health/How-does-ADHD-Affect-the-Brain.aspx

In 1859 in his book, On the Origin of Species, Charles Darwin proposed the fundamental idea of descent with modification, or natural selection, that we still use today as the mode from which the origin of species has evolved. In this book, the only figure he provided for his readers was the figure you all see below. Despite the observed simplicity of this figure, it can be used to represent the whole of evolution from ancestral species, to modern species today. In this blog, I will be explaining this revolutionary figure by Darwin, who is regarded as the father of evolution, and why it was so important to our current knowledge of evolution. 

Darwin created this figure to represent the evolutionary history of life and the mechanisms by which species evolve, depicting the ancestral-descendant relationships of species and how variations have led to divergence, natural selection, and eventually speciation. On the y-axis, we can see time represented in Roman numerals, while on the x-axis, we observe the ancestral species that the modern-day species (at the top of the figure) have evolved from. Each different letter represents a different species, and the exponents associated with it depict the variation from that species and divergence over several generations. Some of these lineages have branches coming from species, representing the natural variation they have and how that variation can be either favored in an environment and increase the fitness of a species (ability to survive and reproduce) and continue through lineages, or be unfavored by the environmental conditions and decrease the fitness of a species, eventually eliminated that species. This process is called natural selection. 

Two fundamental questions Darwin was able to answer by creating this diagram were, first, how are species so diverse, yet so well adapted to their respective environments, and why despite all of these differences, how do species still share similarities? Through natural selection, natural variants in a population will either be favored (be successful) and form new lineages/new species, diverging from the ancestral species and being adapted to its habitat (fit), or go extinct if the variants are not favored or well suited for the habitat (not fit). This explains the diversity of species, as adaptive evolution through natural selection leads to speciation and divergence from a common ancestor. Similarities between species can be explained through the lineages and common evolutionary ancestry. Darwin is able to brilliantly summarize and illustrate these fundamental concepts in a diagram that truly represents the evolutionary history of life!

Have you ever considered exercising consistently before? If you do and actively exercise, that’s great! You’ve probably noticed changes in your body over time and overall increased mental wellness and well-being. If you have or haven’t considered this yet, what is holding you back? In this post, I will be diving into the benefits of consistent exercise specifically in areas of physical and mental health. 

According to healthdirect.gov, a national healthcare service, even getting 30 minutes of exercise a day most days a week is enough time for your body to stay healthy. Yet, so many people today don’t even meet this number because they feel they might not have the time. However, the exercise you want to do doesn’t even have to include going to the gym. Some methods of staying active could be through bicycling, taking walks, and swimming. 

By consistently exercising, the body will gradually show signs of improvement in both physical and mental health. Some physical benefits of exercising include reduced risks for cardiovascular diseases, obesity, cancer, and more. Additionally, it helps with the management of weight and the building of stronger muscles within the body. This allows the individual to understand whether or not to bulk and take in a calorie surplus, or cut and take in a calorie deficit to lose weight and gain more muscle definition. Going to the gym and lifting weights has been shown to help increase or maintain muscle mass and strength, protecting bones, joints, and muscles as the body begins to age and deteriorate. 

Mentally, exercise can help individuals tremendously. Regularly exercising can boost memory, aid with mental health issues, and reduce overall stress (healthdirect.gov). Exercise releases endorphins, chemicals in your brain that make a person feel good and energize their spirits. When these hormones are released, they send a message from the brain to the rest of the body to relieve pain and stress, which can help calm anxiety, depression, and other disorders. Additionally, other hormones like dopamine, norepinephrine, and serotonin levels are elevated through physical activity, elevating our focus without the use of external substances. (helpguide.org)

It’s a more important time than ever to consider picking up exercising considering the number of individuals with low self-esteem, depression, and anxiety has shown an increase in recent years:

“Even before the pandemic, anxiety and depression were becoming more common among children and adolescents, increasing 27 percent and 24 percent respectively from 2016 to 2019. By 2020, 5.6 million kids (9.2%) had been diagnosed with anxiety problems and 2.4 million (4.0%) had been diagnosed with depression.” (Georgetown University Center for Children and Families) 

Since this issue is more relevant today, I would highly advise every one of you to consider those numbers and this alarming state of poor mental health our country is experiencing and wonder how you can take care of yourselves by taking the time to experience the benefits of exercise. 

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Sources:

https://www.helpguide.org/articles/healthy-living/the-mental-health-benefits-of-exercise.htm 

https://ccf.georgetown.edu/2022/03/24/research-update-childrens-anxiety-and-depression-on-the-rise/ 

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1470658/#:~:text=Exercise%20improves%20mental%20health%20by,self%2Desteem%20and%20cognitive%20function.&text=Exercise%20has%20also%20been%20found,self%2Desteem%20and%20social%20withdrawal. 

https://www.cdc.gov/physicalactivity/basics/pa-health/index.htm#:~:text=Being%20physically%20active%20can%20improve,ability%20to%20do%20everyday%20activities.