#diagnostics

Credit: Purdue University photo/Rebecca McElhoe

By Shardell Joseph 

Engineers have developed a handheld paper divide able to detect a strain of coronavirus quickly and accurately. The strain, MERS-CoV, can be detected by the device in very small quantities, and can be read directly from the device making it portable.

As one of the select few given permission by USA health officials to use diagnostics tests for COVID-19, the Purdue University biomedical engineers claimed that this device could be used to detect the COVID-29 strain – the limitations in doing so currently is the lack of funding. According to the team, the process to scale the technology for manufacturing would cost at least a couple of million US dollars.

‘Paper-based devices are already manufactured – pregnancy tests are paper-based,’ said Purdue University Biomedical Engineering Professor, Jacqueline Linnes.

‘Because this device has a more complex shape, a process hasn’t been developed to make it available on a commercial scale. However, many processes in electronics and paper manufacturing could be translated to scaling up this device.’

But so far, Linnes’ team has just been able to produce these devices on a lab scale, which calls for cutting out the paper components by hand.

‘The most difficult aspect of producing this device is definitely the assembly,’ said Purdue University Biomedical Engineering PhD Cadidate, K Byers.

This time-lapse video shows how a paper device developed by Purdue researchers tests a sample in 40 minutes. This sample is positive for MERS-CoV, as indicated by the formation of a second line on the paper strip. Credit: Purdue University video/K Byers

These challenges may easily be overcome with existing manufacturing techniques, the researchers said.

The device format would not need to change in order to detect other diseases. As the device scales up, however, it would also need to be more sensitive to detect a lower concentration of a virus for clinical relevance.

‘This paper device isn’t dependent on a particular virus or sequence. To detect COVID-19, we would just need an assay design specific to that sequence, which could come from a nasal or throat swap sample. Just like with MERS-CoV, a user could load the assay with liquid into the paper platform, fold the device and let it run,’ Linnes said.

When the device folds over, a liquid wash and chemical substances called reagents push the assay up a paper strip to make an easily visible detection line. This automatically completes a multistep process needed for detecting a virus. A user can check the strip within 40 minutes to see if the sample tested positive.

Read the full paper at: https://pubs.acs.org/doi/full/10.1021/acsomega.0c00115?_ga=2.52130409.1579527955.1583773474-378642389.1583773474

“Send Me a Copy of the Labs”

When I get lab results I always go over them with the owner. Generally if there isn’t anything concerning I’ll say everything looks good and there is nothing to worry about. If there are abnormalities we discuss what they mean and what the next steps are, if there are any. Most discussions take less than ten minutes and everyone moves on with their day.

More and more often I am asked by owners to send them a copy of their pet’s lab work. Some people just want a copy to keep in their pet’s file at home which is totally fine by me. Other times something worse happens. The lab results are shared with FB groups, forums, human physician friends or even worse… Googled. Then the emails and phone calls start.

There is so much more to diagnostics than just reading the numbers and seeing if they are red or black. What was the test run for? Was the patient fasted? How old is the patient? What species is the patient? What medications are being used? And on and on.

This lab work below is from one such case. I told the owner everything was within normal limits and we would proceed with the spay. I got a frantic phone call asking why I had not let them know their cat had leukemia and was in liver failure. Let’s look it over. Buckle up because this is a long one.

Before we even look at the results we need to look at the chart for information on this patient. In this case it is a four month old, intact female domestic short hair who was not fasted for this sample. This cat has no medical issues and is not taking medications

First of all we look at the CBC. The reticulocyte hemoglobin is the first red finding. What are reticulocytes? They are immature red blood cells. If there are abnormally high numbers of them it can mean the patient is anemic. Looking at the reticulocyte count we can see that it is within the normal range. So what does the reticulocyte hemoglobin mean? Hemoglobin is the protein that allows blood cells to carry oxygen. Indirectly reticulocyte hemoglobin measures the amount of iron available in the body when the cells were produced. The result is 14.9 pg and the normal range is 15.3-22.9 pg. This cat is completely normal on physical exam and has no symptoms of illness. The rest of the RBC parameters are normal and because this is such a minor decrease we don’t really care.

The next abnormality is a slightly increased white blood cell count. That in itself is pretty non-specific so we have to continue on. We see that the lymphocytes are elevated. This can be because of leukemia, infection, antigenic stimulation, stress response, and other things. It’s really common for kittens to have elevated lymphocyte counts. They are getting vaccinated, have epinephrine going through their systems like crazy at the vet, and are getting antigenic stimulation from the environment. I am not excited about this finding and would just move on.

If you read the little blurb under the CBC it says platelet clumping was noted and may affect the platelet count. This is also a normal finding in cats. This platelet count is normal so it doesn’t matter anyway.

Next we see there were smudge cells present. These are just broken pieces of WBC’s. This can be a sign of leukemia in people and sometimes animals but generally is because cells were broken during transport to the lab or during the blood smear. We know there are high numbers of lymphocytes so there are more cells around to create smudge cells. Not a big deal in this case.

Finally we see the ALP is elevated. This is a liver enzyme but is also found in bone, mammary tissue, and the intestines. It is usually elevated in puppies and kittens because their skeletons are growing so quickly. Not to mention we don’t usually become concerned unless a liver value is approaching 3 times its normal value.

As you can see interpreting lab work is much more complex than you might think. I do that entire process before making any phone calls or talking to owners. When you pay for lab work you aren’t just paying for the diagnostic itself you are paying for the expertise involved in collecting the sample correctly and in interpreting it.

A two year old intact female Boston terrier came in to see me for inappetence, lethargy, and some yellow nasal discharge. Everything was completely normal on exam except for some crusting on the nostrils and a temperature of 103 F. That temperature is on the high end of normal and in a happy, bouncy dog that is doing well at home I wouldn’t be concerned. Since she was not feeling well I decided to run some lab work. While waiting for lab results the patient was given SC fluids and a Cerenia injection.

The WBC is elevated slightly but nothing exciting. Nucleated RBC’s are a little concerning. There is no indication of anemia on this lab work but there could have been previously and the body started pushing out NRBC’s to compensate. What is concerning are the “unclassified” cells.

Mildly elevated glucose is likely due to stress. Glucose levels can be elevated in cases of sepsis or other severe illnesses but the level would be higher. The level isn’t high enough for diabetes but if it was high, we would still need to look at the urine before making that determination. SDMA can mean there is renal disease. The rest of the renal values are normal so we would need to repeat labs every few months to monitor the kidneys. AST doesn’t mean much in this case.

Urine is concentrated meaning the kidneys are working normally and there is no glucose in it which rules out diabetes. The blood in the urine is most likely because it was collected via cystocentesis (inserting a needle into the bladder). The bilirubin is also likely not a concern and is there because the urine is so concentrated.

The blood film was looked at by a pathologist to try to identify the unclassified cells and a large number of lymphocytes were found. The cells could be reactive or cancerous.

Because of this lab work I advised the owner we should take radiographs

These radiographs are fairly normal except for a couple things.

Red circle- Heart

Black outlines-Stomach

Yellow circle-Urinary bladder

Blue arrows- Nipples

Orange arrow- Spleen

Pink Rectangles- Hemivertebrae

Green arrows- Sublumbar lymph nodes

The hemivertebrae are really common in brachycephalic breeds and also German Shepherds. They are a congenital abnormality and can cause problems but often are benign. Nipples can sometimes look like masses on x-ray so it’s important to do a good exam before so you’ll know to expect them. Sometimes if I can’t tell if something is a nipple or a mass I’ll put a little barium on the nipple which will make it bright white on the x-ray. What’s concerning here is the sublumbar lymph nodes. You really shouldn’t be able to see them. The enlarged lymph node and increased lymphocytes on the lab work are very concerning for lymphoma.

This patient was sent to internal medicine for an ultrasound. By the time the appointment came around a week later all of the peripheral lymph nodes were enlarged. A FNA was done on the nodes and the diagnosis of lyphoma was confirmed. She was sent to oncology and is now getting chemotherapy.

And it all started with a runny nose.

Guys, I wanted to let you know about a personal decision I recently made. I don’t really feel like discussing it, but I want to put my position out there. Please be respectful. This is a really long post, but please read the whole thing.

I’m taking the brakes off my car. This isn’t a rash decision, so please listen up.

A few weeks ago I saw a car accident - two people went through an intersection at the same time. Both slammed on their brakes at the same time and collided. Fortunately no one was seriously injured.

But then it occurred to me - if they had just gone through the intersection, they wouldn’t have collided. The brakes CAUSED the accident!

So, I decided to do my own research and what I found was *staggering*: Hundreds of people every year are seriously injured by unnecessary braking. One time, I was driving in the snow and I just lightly tapped my brakes and it caused my car to COMPLETELY LOSE CONTROL. My brakes could have very easily gotten me killed. Even more astoundingly is how often brake pads will warp and distort rotors, causing bumpy rides and squeaky wheels.

And you know what? I also found that decades ago brakes weren’t even used! People would control their vehicle’s speed with downshifting and engine braking. Maybe it’s just coincidence, but back when engine braking was used there were almost no automotive fatalities. There were NEVER brake caused car accidents.

After doing some more digging, I found a nefarious plot - Mechanics: The very people who we trust to work on and care for our cars - get PAID to install and change brakes! You might THINK they care about our safety, or our cars - but they’re just in it for the $49.99 brake pad installations.

So I talked to my Mechanic about taking the brakes off my car and I was disgusted by how poorly he treated me. He accused me of being ignorant, when I was the one that looked up how much rotational torque brakes can put on your rotors. He didn’t even know how much torque a rotor can take before being warped!!! He said “rotors are designed to be compressed, that it isn’t actually a problem” just completely dismissing me.

Then he had the NERVE to say that my personal choice had consequences, that I would affect everyone around me. Well I’ve had it with him, I’m looking for a new mechanic. The problem is that so many mechanics are bought and paid by the automotive industry that ALL of them are insistent about my car having brakes. Most of them won’t even look at my car for other reasons, saying that a brakeless car could cause damage to their shop and other cars. What a bunch of bullshit, they just don’t like those who believe in alternative braking techniques.

Now of course big government is getting involved, saying that I *MUST* have brakes. That this isn’t just about me, and that I could hurt people. What happened to personal freedom? What happened to liberty?

So all I’m saying is, do your research. Don’t just listen to the NTSB and big automotive. I made a personal decision for my family, we just said no to brakes. We’ll be using natural remedies like Gravity, and putting our feet on the ground to stop. After all, if that was good enough for me when I was on my bike as a kid, it’s good enough for my children in my car.

Please keep the comments respectful!

Legal Disclaimer: I am not a mechanic and should not be considered a valid source of information for automotive inquiries.

Spanish Translation provided with many thanks by Martin Romanuk:
https://www.facebook.com/mromanuk/posts/10153602421687782

Italian Translation provided by Loris:
http://locum.doppiopasso.it/io-sono-contro-i-freni/

German Translation provided by Sebastian Wallroth
http://real68er.com/2015/03/03/ich-bin-ein-anti-bremser/