What is Polymerase Chain Reaction ? It is a process of artificial DNA replication (amplification of a selected part of DNA). As the name suggests: Polymerase: It requires DNA polymerase for extending the added primers to complete DNA replication. Chain Reaction: PCR is run in cycles. The number of molecules…
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Why to not defibrillate Asystole ?
What is asystole? Asystole is a state of no cardiac electrical activity. It is seen as a “flat-line” in ECG monitor. However, other possible causes of flat-line should be ruled out before calling it asystole. They are: Loose or disconnected ECG leads Loss of power to ECG monitor Once, asystole…
PGMEE, MRCS, USMLE, MBBS, MD/MS 
Leukocyte Adhesion Cascade and Defect : Simplified
Capture or Tethering Increased vascular permeability and vasodilation are mediated by inflammatory mediators like histamine released by inflammatory cells in response to PAMPs expressed by pathogens. Hemoconcentration (owing to increased vascular permeability) and decreased velocity of blood flow (owing to vasodilation) leads to peripheral pooling of the leukocytes (i.e. towards…
PGMEE, MRCS, USMLE, MBBS, MD/MS 
Amino Acids Mnemonics
What are amino acids ? Amino acids are molecules containing: An amine group A carboxylic acid group A side chain that varies between different amino acids Assign the names of these amino acids to 20 different alphabets The technique that you are going to use to remember all these are given…
PGMEE, MRCS, USMLE, MBBS, MD/MS 
VDJ (Somatic) Recombination Made Easy
Many students feel that, this is one of the most difficult to explain topic in Immunology. Here, we will try to explain the process and clinical relevance of V(D)J or Somatic recombination in simple and interactive way. Question your mind Humans only have about 25,000 genes. Since, an antibody made…
PGMEE, MRCS, USMLE, MBBS, MD/MS 
Cell Cycle Made Easy
Stages of Cell Cycle Interphase Mnemonic: Go Sally Go! Make Children 1. G1 phase 2. S phase 3. G2 phase 4. Mitosis 5. Cytokinesis 1. G1 (Gap 1) phase: Early and late phase divided by Restriction (R) point Functions: Preparation for DNA replication (synthesis of replication proteins cyclin D) Thymidine…
PGMEE, MRCS, USMLE, MBBS, MD/MS 
Apoptosis Made Easy
Definition of Apoptosis Apoptosis is: Origin of the word “apoptosis”: Caspases – Central Regulators of Apoptosis Caspases = Cysteine Aspartate Specific Proteases 2 types of caspases: Initiator caspases: Executioner caspases: 3 Pathways of Caspase Activation 1. Activation of Initiator of Extrinsic Pathway Receptor-ligand interaction mediated: Can mediate intrinsic (mitochondrial) pathway…
PGMEE, MRCS, USMLE, MBBS, MD/MS 
Cellular Adaptations
Hypertrophy, Hyperplasia, Atrophy and Metaplasia are the main four types of cellular adaptations. Adaptations are: Reversible changes In the number, size, phenotype, metabolic activity or functions of cells In response to the changes in the environment (stress). Hypertrophy Definition: Increase in cell size Occurs in: non-dividing (permanent) cells: cardiac and…