Tuesday, August 15, 2017
Wednesday, July 19, 2017
Saturday, June 24, 2017
FENO in asthma: routine clinical testing
One of the additional tests for determining the present status of airways in asthmatics is the measurement of Fraction of Nitric Oxide in Expired air (FENO).
The levels of Nitric oxide are elevated in the presence of inflammation in the airways, that is eosinophilic in nature.
In children <12 years, normal FENO is usually less than 36 ppb. However, in case of allergic inflammation of airways, the levels rise to >50 ppb.
Note that FENO is not diagnostic, but a test for independent prediction of exacerbations in asthmatic patients and is now done routinely in clinical practice, as approved by US- FDA.
Thats all
- Jaskunwar Singh
Friday, May 5, 2017
Sunday, April 30, 2017
Chronic granulomatous disease mnemonic
Chronic granulomatous disease mnemonic
CGD - GRANULES!
G - chronic Granulomatous disease
R - Rhodamine (Dihydrorhodamine abnormal flow cytometry)
R - ROS, Respiratory burst decreased
A - Abscess / Granulomas
N - Nitroblue tetrazolium dye test
N - NADPH oxidase defective
Catalase positive organisms mnemonic: CATALASE!
Candida
Aspergillus
Tuberculosis
Listeria
Staphylococcus aureus
Serratia
pSeudomonas
E coli
That's all!
-IkaN
Tuesday, April 18, 2017
Friday, March 31, 2017
Difference between polysaccharide vaccines and conjugated vaccines
The new generation conjugate vaccines contain carrier proteins that are chemically attached to the polysaccharide antigens. Attaching relatively non-immunogenic polysaccharides to the highly immunogenic carrier proteins means that by activating a T-cell response, conjugate vaccines induce both high-affinity antibodies against the polysaccharide, and immune memory.
So in conclusion:
Polysaccharide vaccine - T cell independent B cell response
Conjugate vaccine - Carrier proteins - T cell dependent B cell response
Mnemonic:
CT (Like a CT scan?)
ConjugaTe has a T cell response
Monday, March 20, 2017
Monday, February 27, 2017
Fish oil for treatment of asthma
Asthma is a chronic, exaggerated and allergic inflammatory response in the respiratory airways to certain allergens that vary according to seasons.
Omega- 3 fatty acids in high- quality fish oils and other products reduce the inflammation by regulating B- cell function. IgE production is reduced, which otherwise acts to cause asthma symptoms and allergic reactions in patients with mild form of asthma.
The fatty acids are used up by the cells in the lining of respiratory passages to produce hormones that tend to "turn- off" certain factors responsible for attracting white blood cells to the site of inflammation such as leukotrienes, interleukins, and other cytokines.
However, these oils are less effective in severe forms of the disease and in the majority of patients taking corticosteroids.
According to a study, prenatal exposure to fish oils (mainly in third trimester) reduces the risk of wheeze and asthma in children.
Thats all
- Jaskunwar Singh
Friday, February 17, 2017
Why does cyanotic heart disease predispose to brain abscess?
Friday, February 10, 2017
Immunohistochemistry and cytogenetics for leukemias: Part 2
Sunday, January 29, 2017
Psoriatic arthritis mnemonic
P- Pencil-in-cup deformity
Pencil-in-cup deformity |
Wednesday, January 18, 2017
Basics of Immunoglobulin G
There are two unique facts about IgG
1)It's catabolism.
2)Suppression of homologus antibody synthesis by a feedback process.
Well we can say body has complete control over the catabolism and to make it simpler let's say body and IgG both acts opposite to each other !.(Just a saying :p,Infact we know IgG works for body).For example In some diseases like chronic malaria ,kala azar or myeloma IgG level rises and as we know body has complete control and it acts against it So, IgG synthesis its gonna catabolised it rapidly !
Conversely,In hypogammaglobulinemia IgG given for treatment is metabolised slowly.
IgG has another unique property of suppressing the antibody synthesis which looks like it or performs similar kind of functions or simply homologus antibody.
Now let's say IgG is quite insecure about its true but dominating love -"Body". It doesn't want any competition so it kicks away all the antibodies which looks like it or perform similar function like him
(Such a insecure antibody it is !)and this unique property is utilised in the Iso-immunisation of a women by administration of anti-Rh(D) IgG during delivery.
It's the only maternal immunoglobulin that is transported across placenta and provides "Natural passive immunity"in new born (Not present in infants )
IgG2=23% (By the way 23 is also half life of IgG)
IgG3=8%
IgG4=4%
Sunday, January 1, 2017
Multiple sclerosis mnemonic
Sunday, December 18, 2016
An AIDS patient with abnormal CT scan
Hey! Here's a case kinda thingy that I made up.
An HIV positive male presents with loss of recent memory and left sided paralysis. A CT scan is done. What are the differentials based on the CT findings given below?
1. Multiple ring enhancing lesions
2. Single, periventricular ring enhancing lesion
3. Cerebral atrophy with secondary ventricular involvement
4. Multiple non enhancing white matter lesions
Answers given below
.
.
.
.
.
1. Multiple ring enhancing lesions - Toxoplasmosis. TMP SMX for prevention!
2. Single, periventricular ring enhancing lesion - CNS lymphoma. Usually, positive for EBV.
3. Cerebral atrophy with secondary ventricular involvement - AIDS dementia complex. Though paralysis would not be a feature. Only defects in short term memory and executive function is seen.
4. Multiple non enhancing white matter lesions - Demyelination of subcortical white matter suggestive of progressive multifocal leukoencephalopathy is caused by JC virus.
That's all!
-IkaN
Sunday, December 11, 2016
Pentavalent vaccines
Let's discuss something about the pentavalent vaccines and what advantage they have in the immunization of newborns..
Friday, December 9, 2016
Rheumatoid arthritis mnemonic
Here's an old mnemonic on some of the clinical features of Rheumatoid arthritis.
Well, the name itself tells it.. RHEUMATOID ;p
R- Respiratory distress (Interstitial lung disease, bronchiolitis, pleural effusion)
H- Haematological manifestations (anemias, thrombocytosis, neutropenia)
E- Extra- articular RA (ExRA)
U- Urinary tract infections (mainly drug- induced)
M- Median nerve compression/ Morning stiffness
A- Amyloidosis
T- Tenosynovitis and bursitis
O- Ocular manifestations (Keratoconjunctivitis sicca, scleritis, episcleritis)
I- Immunologic manifestations (Sjogren's, Felty's and Caplan's syndrome)
D- Deformities (boutonniere, swan- neck, button- hole)
Thats all :)
- Jaskunwar Singh
Monday, September 26, 2016
Study group discussion: Rh incompatibility and ABO incompatibility
Here is some food for thought.
Think about which of the following scenario is worse:
1- Mom is O- and baby is O+ first pregnancy
2- Mom is O- and baby is O+ second pregnancy
3- Mom is O+ and baby is O+ second pregnancy
4- Mom is O+ and baby is A+ second pregnancy
5- Mom is O- and baby is A+ second pregnancy
6- Mom is O+ and baby is O- first pregnancy
Answer is 2
Rh incompatibility in second pregnancy. In presence of ABO incompatibility, Rh incompatibility, has lesser effect.
Detailed explanation:
The most common group O has anti A IgM, anti B IgM and anti AB IgG.
Group A has anti B IgM.
Group B has anti A IgM.
Group AB has no antibodies.
So if I was dumb enough to transfuse GroupyA blood to a group B guy there would be hemolysis. But what would be the mechanism for this?
The patient with group B would have anti A IgM. IgM is a very potent complement activator. IgM is very trigger itchy, it first shoots the cell and then asks questions. So this hemolysis is very fast.
Now coming to the Rh question, imagine there was a mom with O- group and baby with O+ group.
In first pregnancy, the mom is not exposed to the Rh antigen until delivery, so the 1st baby is safe. But there would be a mixture of baby and mom's blood.
Now imagine a weird person (Rh+ cell) walking through an airport, he would taken by the TSA (macrophage) for an "interrogation". So the macrophages do this interrogation (phagocytosis) in the dark corners of spleen and pick up info (antigens) about these weirdos. This info is passed to T cells and they issue warrants to B cells (IgG) for identifications of these guys and they are killed on site (IgG mediated destruction)
You can see that this will, obviously, take time time. When she gets pregnant with Rh incompatibile kid again, the IgG have been synthesized and they cross placenta and attack the baby RBC's. Voila - Hydrops fetalis.
Now imagine a mom who is O- and has a baby with A+ group. This time, at delivery, there is mixing of blood again!
But the mom has anti A IgM which is so fast like a ninja, kills of the majority of the cells before they go for their interrogation with macrophages in spleen... So ABO incompatibility actually protects against the Rh sensitization.
What's the clinical significance of Rh incompatibility?
Whenever you take care of a pregnant lady, you will confirm her blood group and if you suspect Rh incompatibility you would give her "Rh IgG" (standard dose) at 28 weeks, even though the fetal blood is not exposed to mom's immune system, this is done just in case - there might be a fall, injury etc and baby's blood may get into mom's circulation.
Why do you give Rh IgG when you want prevent the disease which is itself caused by IgG?
Rh IgG are heat treated and they cannot cross the placental barrier unlike normal IgG.
And finally, you give another dose of Rh IgG after delivery. But this time, you actually estimate the amount of fetal blood which is mixed with mom's blood by doing "Kleihauer betke test" and you give an appropriate dose.
Explained by DJ AweSpear.
Related posts:
Rh incompatibility
Hydrops fetalis
Blood group doubts
Removal of antigens from RBC's
Barts hemoglobin mnemonic