Saturday, January 8, 2011

Room 425- Quarantine Zone

I seem to have infected the whole block. Everyone is sick haha. Best thing is, I'm almost fully recovered. Sadly the collateral damage includes Kimberley Simai Eddy! Poor thing..

Friday, January 7, 2011

Finally done.

That's it. Im finally done with Immunology. It's unbelievable to find out that there are so many things which we are expected to know but sadly I havent heard mentioned in class. Time to be more proactive Julian! Anyway, here are some sample test questions from the end of the Immunology chapter. If you can get any of them right, good job!:) I also include the answer explanation after the question and bear with me because I will be explaining in my own words (actually just for me to revise:P)


1. Haemophilus Influenza and Neisseria meningitidis both possess a polysaccharide outer capsule. Effective vaccination against these species results in the generation of antibodies that recognize the polysaccharide capsule. Which of the following explains best why the childhood vaccines for H. Influenza type B and N. meningitidis serogroup C are composed of a polysaccharide coat conjugated to a protein carrier.

(a) The protein carrier increases the half life of vaccine
(b) The protein carrier increases the production of IgE immunoglobulins which confer protection
(c) The protein carrier makes the vaccine less virulent and thus decreases the risk of a child developing disease form the immunization
(d) The protein carrier is added to recruit T lymphocyte help and increase antibody production.


Ans: D
Exp: Polysaccharides like many other bacterial antigens are thymus-independent antigens. This means they can cross link the IgM receptors present on the B cell stimulating them to produce IgM without the need for a T lymphocyte to act it. The protein carrier however allows the B cell to present the antigen as recognizable for the T cell thus eliciting a T lymphocyte response as well.


2. Women have about a 2.7 times greater lifetime risk of developing at least one autoimmune disease than men. Which of the following statements, if true, would support the higher rate of systemic lupus erythematosus in women than in men?

(a) Androgens such as testosterone have an inhibitory role in the process of clearing immune complexes.
(b) Both estrogen and androgens have the same potency in inhibiting the clearing of immune complexes.
(c) Estrogen has an inhibitory role in the process of antibody production of B cells
(d) Estrogen has an inhibitory role in the process of clearing immune complexes
(e) Estrogen has a stimulatory role in the process of clearing immune complexes.

Ans: D
Exp: Actually this question is rather straightforward and can be solved just by simple reasoning. Answers A-D all point to the opposite outcome. SLE is a type III hypersensitivity disease. Autoantibodies bind to self antigens and form immune complexes that activate complement, which we all know is a potent activator of neutrophils. Estrogen inhibits the clearing of these complexes hence the greater risk of developing autoimmune diseases.

3. A 23 year old woman comes to the physician for a routine checkup. She has generally been well over the past year although she notes that she has had a few falls recently. On physical examination, a spider angioma is found on her skin. Blood is drawn for laboratory evaluation. The results show that the woman has very low levels of IgA. Based on her presentation, this patient will most likely also present with which of the following symptoms?

(a) Cerebellar problems
(b) Granulomas
(c) Low levels of all other immunoglobulin isotypes
(d) Tetany

Ans: A
Exp: The lady suffers from a disease that is known as Ataxia-telangiectasia. It is due to a defect in DNA repair enzymes. Spider angiomas and ataxia are hallmarks for this disease. Thrombocytopenia can also be observed.

The answer cannot be B because granulomas are seen in another disease known as Chronic Granulomatous Disease. This disease is due to the defiency of NADPH oxidase which results in failure to produce oxygen radicals which we all know is crucial in myeloperoxidase-dependent intracellular killing

The answer also cannot be C because that refers to Bruton's aggamaglobulinemia. It is a X-linked disease and therefore only presents in males. Patient is a 23 year old woman;)

The answer cannot be D because tetany is one of the clinical manifestations of DiGeorge's syndrome. We should know that DiGeorge syndrome is due to the failure of the third and fourth pharyngeal pouches to develop which lead to the absence of the thymus and parathyroid glands. Hypocalcemia is a result and can present with tetany.

Goodnight guys:)

Wednesday, January 5, 2011

Kaplan



Kaplan is simply amazing. For those of you that dont know, they are a company that has prep courses for US board exams.

I managed to download both the video lectures as well as the lecture notes. I even went a step further and purchased some books from Amazon. Among them is Medessentials by Kaplan. Its basically a review of all the basic sciences and system by system review. It includes anatomy, embryology(something I realised I know jack about) , physiology, pathology, pharmacology, biochemistry and pretty much every subject we've learnt so far. I really recommend this book to anyone who wants to brush up their basic sciences during this long winter break.




So far I've managed to cover embryology on a few subjects, a smattering of physio and yeah Immunology. A subject I pretty much know nothing about due to my first sem teacher being Yuri-_- The lady lecturer goes through all the major mechanisms in detail. I was pleasantly surprised to see that all the diagrams used in the lecture and tables could all be found in my Kaplan book. Now thats a good $44 well spent.

If anyone wants any of the lectures or lecture notes, just come along to my room with an empty hard drive. Anything to help my fellow comrades, I'm more than willing:)

Now back to the Immunology lectures at 530am. God they are addictive:) Best feeling is when you find you can act solve the USMLE practice questions at the end of the lecture thanks to the material delivered.

Lets all study damn hard to shake the impression that all russian grads are flops and do well together!

Monday, January 3, 2011

Long Hiatus

It's been a long time since I've had time for myself. Somehow or rather, I feel writing in the wee hours of the morning therapeutic. In the last semester, I honestly can say my learning curve has taken a huge jump exponentially. It's amazing to be on the path of my destiny!

Worries of the future ahead still plague me from time to time. All I can do now, is study hard and study smart. Pray for the best because i truly believe that my future holds great things in store for me.

Jeremiah 29:11

For I know the plans I have for you," declares the LORD, "plans to prosper you and not to harm you, plans to give you hope and a future.

Amen, I hold true to your promise God. In the mean time, I'm gonna study my brains out!:)