Tonight, I want to venture a little out of my area of knowledge into a couple of other disciplines of pathology, namely, hæmatology and chemical pathology.
The subject matter though are two tests we use as indicators of acute phase inflammation. One is a very old test and the other is old but not that old, by which I mean it’s been used commonly in my life time. Read More
Tonight, I want to touch on a little bit of serology, specifically, the basic serology associated with infection from Hepatitis B virus. This is my ideal world view of HBV serology and shouldn’t be interpreted in conjunction with health insurance payment schedules or payments in general. This view is patient-centred and what I’d like to do if cost wasn’t an issue.
I think everyone should know their HBV status. We live in a world were HBV infection can be prevented in most people through immunisation. In fact, the HBV immunisation was the first vaccine to prevent a malignant disease, i.e., hepatic carcinoma or live cancer (yeah, I know I don’t like saying cancer but for ease of use in the podcast I said it). Read More
The human ear is a great spot for infections of all kinds. Before going straight to the bacteria and viruses, it’s important to understand a little simple anatomy.
The outer ear, is exposed to the environment and wherever you put your head. The middle ear is relatively protected but it has a direct connection with your oropharynx via the Eustachian tube. The inner ear though is the most protected area except that the nerve endings are bathed in the ultrafiltrate of serum. Whatever gets through the filtration system can get to the nerve endings. Read More
Tonight, I want to describe how we examine cerebrospinal fluid in the microbiology laboratory. I’m going to limit myself to a context of patients with acute meningitis.
Imagine you have a sudden onset of the worst headache ever and a high fever. It hurts to open your eyes in bright light and when you try to bend your head down to look at the ground it hurts. You feel like death warmed up. You may also have a funny blotchy rash forming on your skin. You have signs and symptoms suggestive of acute bacterial meningitis. You need urgent medical attention. In the old days, you’d be seen and a lumbar puncture would be performed as soon as possible. These days, you’ll be triaged urgently, assessed quickly, blood will be collected for culture, antimicrobials will be administered and then you’ll be sent to have a CT scan of your head to make sure you don’t have a space occupying lesion. If you do have a SOL whether it be a tumour or abscess you run the risk of coning. This coning is worse than the grand cone that pathologists in private practice in Australia complain about, this form of coning occurs when you have a space occupying lesion in your brain and when you insert a lumbar puncture needle the sudden pressure differential results in the hindbrain pushing the brainstem through the foramen magnum at the base of your skull which can then result in compromising your cardiorespiratory centres so you stop breathing. Coning, is never a good thing. Read More
I bet you’re wondering why am I wanting to mention something so outdated in a world of enzyme immunoassays, robotics and automation?
Well I got my start in pathology because of hæmagglutination inhibition or HAI. In 1982 when I was in grade twelve I did a biology project at a local medical testing laboratory. The pathologist in charge was very encouraging. The original project involved looking for antibodies to rubella virus after immunising mice with the rubella vaccine. The assay I used to measure the antibodies was an hæmagglutination inhibition assay. Part II of the study involved comparing HAI with an immunofluorescence assay and an enzyme immunoassay. Read More