AP Biology class blog for discussing current research in Biology

Author: tedigrade

The Incredible Work of Percy Lavon Julian

This post will focus on the incredible life of Dr. Percy Lavon Julian (1899-1975), an African-American chemist whose groundbreaking work with steroids allowed them to be mass-produced cheaper and developed hundreds of treatments and new technologies. Julian was born the son of a railway clerk and the grandson of enslaved people in Montgomery, Alabama, As such, he faced extreme discrimination and challenges in all aspects of his life, especially in his education. Against all odds, he was accepted and graduated as the valedictorian of DePauw University in Greencastle, Indiana. From there, he was awarded an Austin Fellowship to Harvard University where he furthered his education in chemistry. However, due to his race, he was not allowed to pursue a doctorate at Harvard, so he traveled to the University of Vienna in Austria in order to complete his doctorate and continue his research.

It was at the University of Vienna where Julian really dove into the chemistry of plants as well as synthesis, a passion that would lead to many groundbreaking discoveries. After being granted his Ph.D. from the University of Vienna, Julian returned to DePauw University as a research fellow where he made his first of many significant breakthroughs using synthesis. He and a fellow Viennese colleague synthesized physostigmine, a compound from Calabar beans that is vital in treating glaucoma. Since chemical synthesis (the process of turning one substance into another through a series of planned chemical reactions) was the most popular topic in chemistry, Julian was hurtled to the top of the science world. In fact, in 1999, the American Chemical Society denoted their work as a “National Historic Chemical Landmark.” Despite this revolutionary breakthrough that helped many people, DePauw University refused to make Julian a permanent faculty member due to his race. Julian quickly became frustrated with the world of academics and instead became the director of research at the Glidden Company.

It was at the Glidden Company where Julian made his most significant discoveries through soybeans. While researching how to synthesize Progesterone, a female sex hormone that is important in preventing miscarriages in pregnancies, Julian discovered that water had leaked into a vat of purified soybean oil and had produced a white mass. Julian quickly identified this white mass as stigmasterol, a compound that is extremely important for synthesizing progesterone, and realized he had discovered a way to cheaply mass-produce progesterone. This dramatically reduced the price of this important hormone and made it much more accessible to people all over the world. This was not the only amazing work that Julian did with soybeans, among his other achievements, he discovered a way to cheaply produce synthetic cortisone, a “miracle” drug that had significant effects on rheumatoid arthritis. Before Julian’s research, this drug was extremely expensive and therefore inaccessible to some people. Julian’s synthetic cortisone alleviated the pain and suffering of people all over the world. Julian did not only discover ways to synthesize steroids while at Glidden. For example, a protein he extracted from soybeans was used to produce a fire-retardant foam that saved thousands of lives in World War II.

In 1954, Julian left Glidden in order to start his own company called Julian Laboratories which cheaply produced steroids to sell to pharmaceutical companies. Julian was found to be as capable an entrepreneur as a scientist, making millions from selling his company. Despite Julian being named “Chicagoan of the year” and his incredible achievements, he faced significant discrimination both in his professional and personal life, having his home firebombed and being repeatedly held back from the best resources. Despite all of this, Julian left a tremendous legacy of groundbreaking work that allowed for the cheap production of medicine and a legacy as the man who broke the color barrier into American industrial science. At the time of his death, Julian had more than 100 patents to his name, 18 honorary degrees, and more than a dozen science and civic awards.

CRAZY NEW COVID-19 Mutation Makes Virus Weaker Against Antibodies

As revealed in a fascinating article that details a study conducted by the University of North Carolina at Chapel Hill, a mutated form of the virus has been discovered to be much more susceptible to antibodies produced by antibody drugs. This means that it is more easily disabled by antibodies produced by drugs such as the new vaccine. However, this may not all be good news as this new strain, called D614G, is also much more transmissible. D614G originated in Europe and has quickly become the most prevalent form of the virus. According to professor of epidemiology at UNC Ralph Baric, “The virus outcompetes and outgrows the ancestral strain by about 10-fold and replicates extremely efficiently in primary nasal epithelial cells, which are a potentially important site for person-to-person transmission.” These nasal epithelial cells act as a physical barrier against any pathogens attempting to enter the body and play a significant part in the control of the innate and acquired immune response. As we learned in biology, one method of innate immune response that our bodies have is mucous that traps pathogens. The nasal epithelial cells contain cilia that act to push the mucous and the pathogen contained inside out of the body. This means that if this new virus reproduces exceptionally well within the nasal epithelial cells, then it is extremely transmissible through any expulsion of mucous by either sneezing or coughing. It is also far more capable of bypassing the barrier of the mucous and entering the body. These epithelial cells also help the innate immune system by producing various cytokines. If a virus manages to make it past the barrier defenses, the epithelial cells will secrete cytokines. These cytokines will attract a type of cell called a neutrophil that digests pathogens. This means that these nasal epithelial cells are vital to the innate immune response and having a virus strain reproduce so effectively inside of them is extremely worrying.

The researchers believe that D614G is so effective at reproducing because it increases the virus’ ability to enter cells. The D614G mutation opens a flap on the tip of one of the spikes on the side of the virus which allows it to infect cells more effectively. However, this mutation also creates a weakness in the virus. When the flap is open, it becomes much easier for antibodies to bind to the spike proteins, preventing the virus from attacking additional cells.

Two researchers from the University of Wisconsin contributed to this study by experimenting with hamsters. To test the airborne aspect of this mutation, the hamsters were placed into different cages and groups so they could not touch and inoculated with either the original strain or D614G. By day two, in the group exposed to the mutation, six out of the eight hamsters were infected with D614G. In the group of hamsters exposed to the original virus, no additional hamsters were infected by day 2. This shows that this D614G is extremely effective at being transmitted airborne. However, the mutation had the same symptoms and effects as the original virus meaning it is not more severe. The researchers have also noted that these results may not be the same in human studies. I think that this study is equal parts of good and bad news. I am glad that the most prevalent form of the virus is much easier to deal with, but it is quite terrifying that it could mutate to be so much more contagious. How do you feel about this new development? Let me know in the comments. 

Shocking Connection Between Ancient Neanderthals and COVID-19

As stated in an article that details the shocking discoveries of an investigation led by Professors Svante Pääbo and Hugo Zeberg, genetic material from our neanderthal ancestors can be linked to the development of severe COVID-19. COVID-19, as I am sure you are all aware, is the disease ravaging the world and is caused by the newly

discovered coronavirus. While most people only have mild reactions to the disease and recover relatively easily, some people with underlying conditions may have a severe reaction to the disease and require hospitalization. However, this new study indicates that certain people may be genetically predisposed to a severe COVID-19 reaction, and it all links back to our 60,000-year-old Neanderthal ancestors.

The study that discovered this connection analyzed the genetic material of 3,000 patients who had both severe and mild COVID-19. The study identified a section of the chromosome that contained the genetic material responsible for the severe COVID-19. Chromosomes are tiny structures located in the nucleus of cells and these structures hold the genetic material that determines virtually everything about the cell. This genetic material is made up of nucleic acids that — when combined into a double-strand helix by covalent bonds between the phosphate, sugar, and base groups– create DNA. The order of the bases in the chain determines the amino acid sequence. We inherit our genetic material from our parents, and chromosomes are present in pairs, with one part of the pair inherited from each parent. This means that you hold genetic information from your earliest ancestors, which could potentially include Neanderthals. Neanderthals were archaic humanoids that were eventually assimilated into the homo sapien species.  However, cross-breeding was required to absorb the Neanderthals into our species, which means that most of the people alive today have a percentage of Neanderthal DNA. If a person holds one of the thirteen variants that are present in Neanderthal DNA, they are far more likely to have severe COVID-19.

Professors Pääbo and Zeberg proved this to be true by discovering that the Neanderthal variants distinctly matched the variants associated with severe COVID-19. However, they discovered that the genetic material only originated from Neanderthals located in southern Europe. Therefore, they concluded that when the Neanderthals of southern Europe merged with present-day people 60,000 years ago, they introduced the DNA region responsible for severe cases of COVID-19. Additionally, the people who possess these Neanderthal variants today are three times more likely to have severe COVID-19. The fact that I found the most interesting is how dramatically the presence of the variants vary in different parts of the world. For example, in South Asia, 50% of the population holds the variants, but in East Asia, almost nobody has them. I also think that it is rather tragic how genetic material that has not had any effect on the world for 60,000 years is just now becoming active. What do you think about this discovery? Why do you believe Neanderthal DNA is causing these extreme cases?


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