11-cis-retinal combines with opsin protein to form rhodopsin. Light stimulates conversion of rhodopsin bound 11-cis-retinal to all-trans-retinol (all-trans-retinol is transported from photoreceptor cells to retinal pigment epithelium), which subsequently dissociates from opsin (bleaching), leading to membrane depolarization and initiation of action potential in photoreceptors in the neural retina. Once in…
Category: PGMEE, MRCS, USMLE, MBBS, MD/MS
Medical knowledge in bullet points with understandable language, simplified images and graspable mnemonics.
PGMEE, MRCS, USMLE, MBBS, MD/MS
Differential Diagnoses of Bone Tumors : Mnemonic Approach
Lytic and Sclerotic Bone Lesions Mnemonic for Solitary lytic lesions: FEGNOMASHIC Fibrous dysplasia Enchondroma Eosinophilic granuloma Giant cell tumor Nonossifying fibroma Osteoblastoma, Osteosarcoma (telangiectatic) Metastases Myeloma Aneursymal bone cyst Simple bone cyst Hyperparathyroidism (brown tumor) Infection Chondroblastoma Chondromyxoid fibroma Mnemonic for Multiple lytic lesions: FEMHI Fibrous dysplasia Eosinophilic granuloma/Enchondroma Metastasis/Mutiple…
PGMEE, MRCS, USMLE, MBBS, MD/MS
Errors and P-value
Statistical hypotheses Null hypothesis (H0): No difference or relation exists; e.g. Treatment A is not better than Treatment B Alternative or research hypothesis (H1): Some difference or relation exists, e.g. Treatment A is better than Treatment B Statistical errors Type I error (alpha): False positive (Falsely rejecting Null-hypothesis; i.e. null…
PGMEE, MRCS, USMLE, MBBS, MD/MS
Baye’s theorem derived PPV and NPV
Let’s unveil the mathematics behind the relation between: Prevalence (Pre-test probability) Predictive value (Post-test probability) Sensitivity Specificity SYMBOLS: Total screened population = nPrevalence = PSensitivity = SnSpecificity = SpTrue positive = TPTrue negative = TNFalse positive = FPFalse negative = FNWith disease = D+Without disease = D-Positive predictive value =…
PGMEE, MRCS, USMLE, MBBS, MD/MS
Screening tests in Series and Parallel
A. Parallel testing 2 screening tests are applied simultaneously: So, this test will have: B. Series testing After the 1st screening test is conducted, those who test positive are only tested with the 2nd screening test: So, this test will have: Formulae for combined specificity and sensitivity A. Parallel testing:…
PGMEE, MRCS, USMLE, MBBS, MD/MS
Sustainable Development Goal 3 – Points to Remember
Total SDG goals: 17 Time frame: 2016-2030 Goal 3: Good health and well beings for all ages Important targets of Goal 3 (Targeted by 2030) A. Maternal and Child health (MCH) Mnemonic: 12 letters in “NEONATE DEATH or NEWBORN DEATH“. 1. NMR reduction target: 122. U5MR reduction target: 12 X…
PGMEE, MRCS, USMLE, MBBS, MD/MS
Key Health Indicators of Nepal to Remember (NDHS, 2022)
These rates, ratios and proportions are often questioned in PGMEE, pediatrics, obstetrics and preventive and social medicine (PSM) or community medicine examinations. NDHS = National Demographic and Health Survey a. Neonatal mortality rate (NMR): 21 per 1000 live births (i.e. 3/4 of infant deaths) b. Infant mortality rate (IMR): 28…
PGMEE, MRCS, USMLE, MBBS, MD/MS
Oncogenic Translocations to remember
t(8;14): Burkitt’s lymphoma t(14;18): Follicular lymphoma t(11;14): Mantle cell lymphoma t(11,18): Marginal zone lymphoma (MALT lymphoma) t(9;22): CML (Philadelphia chromosome), Bad prognosis ALL t(8;21): AML M2 t(15;17): AML M3 (Promyelocytic AML) t(X;18): Synovial cell sarcoma t(11;22): Ewing’s sarcoma t(12;21): Pre-B ALL (good prognosis ALL) t(4;11) and t(1;19): Bad prognosis ALL