Healthline just launched a video campaign for Multiple Sclerosis (MS) called “You’ve Got This” where individuals living with MS can record a short video to give hope and inspiration those recently diagnosed with MS.
Healthline will be donating $10 for every submitted campaign to the National MS Society, so the more exposure the campaign gets the more the videos it’ll receive and the more Healthline can donate to MS research, support groups, treatment programs, and more.
The realm of genome editing has taken a significant step forward with the recent discovery, called CRISPR technology. CRISPR originates as an immune mechanism used by bacteria to fend off against virus infection. What is fascinating about CRISPR is that bacteria takes a chunk of DNA from virus and store it inside its genome. Then, when the virus infects the bacteria again, the bacteria is able to use the chunk of DNA that it stole as a surveillance tactics. Once it matches the virus DNA, it triggers a cascade of editing of the virus DNA to get rid of the infection.
What you see here is the bacteria genome at the bottom. The CRISPR locus (labeled as CRISPR array) is identified by the DNA repeats (black diamonds), with specific virus DNA (multicolor boxes) spaced between these repeats. Upstream of this CRISPR locus is the Cas locus, which consists of important enzymes and proteins that assemble and facilitate the excision.
CRISPR stands for clustered regularly interspaced short palindromic repeats). Inside the CRISPR locus, you will see DNA repeats intercalated with specific DNA sequences (in the diagram it says spacer). These DNA sequences are sequences that the bacteria acquired from previous round of infection. After transcription, these DNA repeats are transcribed into RNA that carries hairpin structures. These RNA are called crRNA. These crRNA can then be used to target unwanted pathogens to degradation. Upstream of this CRISPR locus, you will be able to find cas genes.
CRISPR locus generates hairpin RNA, crRNA. Cas locus generates Cas proteins.
Depending on what types of CRISPR, some or just one Cas genes are required for assembling and cutting the target DNA.
Since a lot of inventions are evolved around the type II CRISPR system/Cas9, I will focus on the type II CRISPR system that requires a large multifunctional protein to destroy invading DNA and a trans-activating crRNA (tracrRNA). After crRNA binds to the target DNA, tracrRNA binds to crRNA and recognized by Cas9 and then cleaved by RNase III
crRNA identifies target DNA. tracrRNA then binds to crRNA, which triggers the Cas9 protein to latch on. This triggers RNAIII in forming a double stranded break in the target DNA
From this knowledge, scientists have derived a new strategy in genome editing. They combined the fundamentals of crRNA and tracrRNA. So now, you can customize the stretch of crRNA and then add on the chunk of tracrRNA that Cas9 requires to activate the excision cascade (see below).
The crRNA can target the gene that you want to target. Though you still have to express Cas9, in order to facilitate the genome editing.
I recently read an article that talks about a possibility in which mandatory requirement for all to do the HIV test in Canada.
Overall, the mandatory requirement will be good in general. Most infections do not become AIDS right away upon infection. In fact, infected individuals can go on for months or even years before they begin to experience the symptoms. In other words, individuals can infect others during that ‘symptomless’ window.
So mandatory requirement is a good plan.
But implementing this might be difficult and costly. Tests for HIV are commonly fallen into two categories: ELISA and PCR. ELISA detects on antibody against HIV in your body, whereas PCR detects the integration of HIV in your genome.
ELISA is far less superior than PCR in detecting PCR, since antibody production takes at least 2 months. PCR detects the integration of HIV into your genome, which means the detection is more direct and better to detect early infection.
ELISA based tests tend to be free these days in community clinics, whereas in the US, you have to pay $100+ US for the PCR test. The cost is therefore polarized when it comes to what accuracy you want. Perhaps the implementation of the plan can allow individuals to pick between the two – and hope that the more sexual active individuals would be more inclined to take the PCR based tests.