Pathology videos & books

A 19-year-old college student presents with fatigue and sore throat. His peripheral smear shows atypical lymphocytes. His Monospot test is positive. What is the likely causative organism? Comment upon this. Try without options. We have discussed it so many times.

Correct Answer - C Malakoplakia [Ref. Robbins 7th/e p 1027-1028] • Malakoplakia is a variant of cystitis, it is related to chronic bacterial infection mostly by E.coli or occasionally by proteus species. • It is characterized by unusual appearing macrophages and giant phagosomes. • It points to defect in phagocytic or degradative function of macrophage. • It is apeculiar pattern of vesical inflammatory reaction characterized microscopically by soft, yellow, slightly raised mucosal plaques 3-4 cm in diameter. • Histologically it is characterized by infiltration with large foamy macrophages with occasional multinucleate giant cells and interspersed lymphocytes. • The macrophages have an abundant granular cytoplasm and the granularity is PAS positive. • In addition to these histological changes, malakoplokia is also characterized by Michaelis Guttman bodies. - Michalies Guttman bodies are Laminated mineralized concretions resulting from deposition of calcium in enlarged lysosomes. ⁃ They are typically present both within the macrophages and between cells

Based on the above keywords hint:* Raised, shiny scar Extends beyond original wound Progressive growth Type III collagen Ans is keloid

aksuggie@gmail.com H1 Histone protein binds to the linker DNA. Structure of chromatin: • Within the cell nucleus, the DNA is wrapped in 1.8 loops, around a core of histone proteins • This DNA which encircles the histone proteins consists of 147 base pairs. ◦ The core histone proteins consist of 2 sets each of the histone proteins H2A, H2B, H3 and H4, giving a total of 8 histone proteins known as the histone octamer. ◦ This DNA-histone complex is known as the nucleosome. • The nucleosomes are connected by DNA segments called linker DNA. Both together constitute the chromatin, giving the appearance of "beads on string, where the beads represent nucleosomes and the string represents the linker DNA. • The H1 histone protein binds to the linker DNA and helps stabilize the overall chromatin architecture. ◦ Notably, the histone proteins are positively charged, which facilitates the compaction of the negatively charged DNA.

SNPs are said to be bi-allelic. The two most common genetic variations or polymorphisms are ◦ Single-nucleotide polymorphisms (SNPs) ◦ Copy number variations (CNVs) A. SNPs ◦ These are variations in a single nucleotide that occurs at a specific position (locus) in the genome • They are always bi-allelic, that is, only two choices exist at a given locus in a populati (-CorA-). The image below shows a C/A SNP. The upper DNA molecule differs from the lower DNA molecule at a single base-pair location.

Ans. is 'd" i.e., High risk of malignacy o Malignancy is rare in harmartomatous polyps of Peutz-Jeghers syndrome. . Other three options are correct

45-year-old woman having salt and pepper appearance in skull with dentine defects and loss of lamina dura most likely suggests hyperparathyroidism Radiological features of hyperparathyroidism: ◦ Classical and pathognomonic feature of hyperparathyroidism is sub-periosteal cortical resorption of middle phalanges, seen especially in the second and third fingers. This feature can also be visualised in lateral end of clavicle and symphysis pubis ◦ Loss of lamina Dura (thin cortical bone of tooth socket surrounding teeth is seen as thin white line) ◦ Generalized osteopenia, thinning of cortices, and indistinct bony trabeculae ◦ Expansile lytic lesion, otherwise known as brown's tumor generally affecting maxilla/mandible ◦ Salt and pepper appearance of skull