Author Archives: hani ghaffari-marandi

Untapped Area of Research in Stress Hormones

       Everyone has experienced stress before, but where is it all coming from and how can our body deal with it? According to the American Psychological Association, the average stress levels rose from  4.9 to 5.1 out of 10 in 2015. It seems that stress is everywhere, but this can be both good and bad. Stress is a natural response that occurs when we experience a demand that seems threatening. It is a result of brain chemicals called hormones being released in our body in response to the demand. Low levels are healthy as they help us accomplish daily activities, but too much stress can have very negative effects on our physical and mental health. Therefore, managing stress and the hormones related to it can be very important for our overall health. However, research shows that we are missing important facts on how stress hormones are made.

       Jordan Hamden and a team of researchers from the University of British Columbia (UBC) are investigating how stress hormones are created in the body. Specifically, he looks at the regeneration of a stress hormone called corticosterone in tissues of rats, mice, and songbirds. The creation of corticosterone in these tissues is due to an inactive molecule called 11-dehydrocorticosterone (DHC). DHC regenerates corticosterone and thus, is another source of hormone production (hormones regenerate).

        Jordan’s research team found a way to measure DHC, something that has not been done before. This was accomplished by creating an immunoassay. This test uses other molecules that can tag DHC in the tissue and then make it visible to researchers. Jordan then measured how DHC levels change as mice develop. Results showed that the presence of DHC was most notable during a period of development called the Stress Hyporesponsive period (SHRP). SHRP occurs in both rodents and other species, such as humans, and is unique because it is when normal stress responses are not observed, including the release of stress hormones from the brain. It allows researchers to look at other important, but less obvious processes happening in the body such as hormone regeneration within tissues. As a result, Jordan found that this was when the conversion from DHC to corticosterone was most prominent.


Immunoassays show how some tests are colored differently to tell researchers that the protein in question is present. (Source: Flikr Commons)


Podcast about how this period is gaining fame in research, including Jordan’s.


         Jordan also looked at the stress response of songbirds and rodents, and if DHC levels were affected. He found that DHC increased when the animals were stressed. There are a few theories as to why this occurs but more research is needed before a conclusion can be made.

         Research shows that we do not see the entire picture when considering how the body creates hormones. This can greatly affect treatment plans for hormone-related problems. Additionally, it may allow us to target specific tissues for hormone regulation. Either way, more research is being done so that we can continue our current understanding of how hormones in the body are created.

Short video of how Jordan’s results can have future implications in medicine.


By: Katie Donohoe, Hani Ghaffari, Malavan Subramaniam, Qiuning Lyu

Genetic Genealogy: Using DNA for Police Investigations

Catching Culprits

The Golden State Killer terrorized California from 1974 to 1986. He killed at least 13 people and committed a series of rapes and burglaries during this twelve-year period, but was never caught. On April 24, 2018 however, Sacramento County Sheriff’s Department arrested Joseph James DeAngelo, who they believed was responsible for the crimes, before formally charging him. Genetic Genealogy was responsible for bringing him to justice and now crime solvers believe that more cold cases can be solved with this exciting method. While DNA profiling has been around since 1984, the genetic database was not large enough at the time to be as effective as it is today.  How it works is that genealogists upload DNA sequences from a crime scene to a large database consisting of genetic profiles from a mass of other individuals in order to find the relatives of an unknown suspect. Afterward, they narrow in on the possible perpetrator by constructing a family tree and pass on the information to law enforcement.

A Family Tree. Image from:                                  


But First… what are SNPs?

Single Nucleotide Polymorphism (or SNPs) are markers in our entire DNA set. They signify that a portion of individuals will have one building block, called a nucleotide, at a specific position in a nucleotide sequence, but other people will have a different nucleotide (four different types) at that same position.  The two forms of SNPs are known as alleles.

This segment of a DNA strand has one SNP that does not match. Image from Molecule World:


The Process

So how do genealogical DNA tests work? There are actually three major types of tests that can be conducted. Our focus is on the autosomal DNA test, which targets chromosomes 1-22 for analysis (the non-sexual somatic chromosomes). This testing method allows individuals to be matched within a database. An individual being tested may have a number of consecutive SNPs in common with a person already in a system’s database, in which case it can be inferred that they share a DNA segment within that section of their genomes. If this segment is longer than a threshold value set by a certain group, then the two subjects are treated as a match. Since half of the genetic information is inherited from each parent, the SNP of each individual decreases by approximately half each generation, but genealogical DNA tests generally account for about 700,000 SNPs. With this in mind, it is not expected that even somewhat distant family members will fail to match (as was the case in DeAngelo’s situation).

Video about how DeAngelo was caught. Video from CBC News: The National.


The Limitations

While this method is very effective, it does pose some limitations as well. DNA that is contaminated, degraded, or too small in amount can leave room for doubt when attempting to make a match. Also, due to privacy issues, many DNA-testing firms will not provide law enforcement any access to their database without consent from the user of the data or by a court order.

Genetic Genealogy is an effective way of solving cold and even active criminal cases. While some restrictions exist, the vast database now available can be a great resource for law enforcement.

– Hani Ghaffari