Dumb Medical Questions

Q: What is the Function of Interferon Ɣ and Interleukin 2 in Leprosy?? Answer: 1. A few facts first : T helper cells are CD4 + cells and have three subtypes: Th1, Th2 and Th17 . We are only concerned with Th1 (fights intracellular bacteria,viruses) and Th2 (extracellular parasites and allergens) here. Th1 and Th2 are sworn enemies and oppose each other. Interferon Gamma (IFN  Ɣ) i s the most important cytokine secreted by the Th1 subtype. Functions:   a ) It activates the macrophages.   b ) It inhibits Th2 response and further amplifies Th1 response. Interleukin 2 (IL-2)  is secreted by the Th1 cell and has diverse functions:( this is what is known so far): a ) It activates T cells and helps in proliferation of specific T cell responses( specific to that infection/antigen, as in adaptive immunity. b ) It also downregulates immune responses non specifically via T Reg cells as in innate immunity.( won’t stress here)  2. Now ...

Q. What is the role of sentinel lymph node biopsy in breast cancer and when is it done? Is it done before axillary dissection or to avoid axillary dissection? What is a sentinel lymph node? A ‘sentinel’ is defined as a soldier or guard whose job is to stand and keep watch. This might lead somebody to incorrectly believe that a sentinel lymph node somehow guards against the spread of cancer, when it is merely an indicator of spread and a sort of conduit for the malignancy in question to metastasise lymphatically. The concept here is that the route of lymphatic metastasis passes through the sentinel lymph node – so, in theory, if we examine the sentinel lymph node and it does not show signs of metastasis, we can say with a reasonable amount of certainty that the lymph nodes beyond it are not involved, allowing us to not remove the larger group of lymph nodes in question. Figure 1: This is a helpful diagram to illustrate the position of a sentinel lymph node. For the ca...

Q:"Is it possible to do tendon jerks? I've watched videos yet I'm not able to do them on patients. What do I do?" A: The most common reason for poor demonstration of DTRs clinically is improper technique.  One of the most important step is to completely expose the muscle who’s reflex is being tested. For example, for a knee jerk – it is the contraction of the quadriceps muscle that should be looked for rather than the more optimistic jerking of the knee which will not be seen in most normal people or persons with diminished reflex, hence exposing the patients thigh is a key feature.  YouTube videos often show demonstrations of exaggerated reflexes in patients suffering  from UMN lesions and hence one should not expect to reproduce the same level of findings in a normal patient. Another common cause of failure with demonstration is that the patient is not relaxed or is concentrating on the procedure being performed. After a general explanation, mingle th...

The Icebreaker: What is Contraction alkalosis ?? The word 'contraction' in contraction alkalosis refers to fluid contraction or in other words, fluid loss . So when the body loses fluid (typically seen with diuretics) it tries to get all that fluid back. Q: How can the body do this ?   A: By increasing the serum sodium concentration. (increased sodium concentration --> increased osmolarity of serum --> increase in intravascular volume) Q: How does the body do it ? A:1) The decreased blood volume is sensed as decreased blood pressure felt by the kidneys at the glomerulus ie. decreased renal perfusion pressure. There are modified smooth muscle cells in the afferent arteriole that detect this change called JG cells . They secrete Renin in response to the low pressures.  2) By the diagram shown below Renin activates an axis that gives rise to Angiotensin II and aldosterone.   The Renin-Angiotensin-Aldosterone axis   3...

This is a latin phrase that translates to 'Do No Harm', and also describes the dominating feeling when a medical student feels when he/she/they has a doubt at the end of a class. By avoiding 'harm' by testing a professor's patience or in efforts to preserve one's own ego, a lot of questions are left inside, waiting to be answered, and google searches often disappoint. So we're a bunch of students from the Armed Forces Medical College, Pune, India preparing for our residency exams and we'd love to clear your doubts without judgment. (We'll try to make it as clear and concise as possible.) Give us your questions  here . Remember, there are no stupid questions, only stupid answers!