Histopathology of alkaptonuric ochronosis

Jaundice, or icterus, is the yellow discoloration of the skin, sclerae, and mucous membranes. It happens when plasma bilirubin levels rise above 2.5-3 mg/dL, leading to bilirubin deposition in tissue.Bilirubin is a byproduct of hemoglobin degradation. In macrophages, hemoglobin breaks down into globin and heme. Globin is converted into amino acids, while heme is turned into biliverdin by heme oxygenase, which is then reduced to unconjugated bilirubin by biliverdin reductase.Unconjugated...

Oxidation of aldehydes and ketones results in the formation of carboxylic acids. Aldehydes, bearing hydrogen next to the carbonyl group, are easily oxidized compared to ketones. This is because an aldehydic proton can easily be abstracted during oxidation.
Aldehydes readily undergo oxidation in strong oxidizing agents such as potassium permanganate and chromic acid. The oxidation can also be carried out using mild oxidizing agents such as silver oxide. In fact, aldehydes can be easily oxidized...

Lysosomes are the site for the degradation of macromolecules and biological polymers released during membrane trafficking events such as secretory, endocytic, autophagic, and phagocytic pathways. The membrane-enclosed area of the lysosome, called the lumen, contains hydrolytic enzymes active in an acidic environment. These acid hydrolases are functional at a pH between 4.5 and 5 and are involved in cellular processes such as cell signaling, energy metabolism, restoration of the plasma membrane,...

The microscopic anatomy of the liver is a complex and intricate system that comprises numerous structural units known as liver lobules, each of which is comparable in size to a sesame seed. These hexagonal structures consist of plates of liver cells or hepatocytes, which are characterized by their versatility and abundance of cellular apparatus like rough and smooth ER, Golgi apparatus, peroxisomes, and mitochondria.
Hepatocytes perform a variety of essential functions. They secrete...

Smooth endoplasmic reticulum or smooth ER is a sub-organelle with specialized functions in animal cells and plant cells. It is often associated with the tubule morphology of the endoplasmic reticulum.
The ER provides optimal conditions for synthesizing steroid hormones and lipids, such as phospholipids and triglycerides. Traditionally, lipid metabolism was considered to be a smooth ER function. However, there is no direct evidence to prove that rough ER is completely excluded from lipid...

The first thing a clinician sees is the skin, so the examination of the skin should be part of any thorough physical examination. Most skin disorders are relatively benign, but a few, including melanomas, can be fatal if untreated. A couple of the more noticeable disorders, albinism and vitiligo, affect the appearance of the skin and its accessory organs.
Albinism
Albinism is a genetic disorder that affects (completely or partially) the coloring of skin, hair, and eyes. The defect is primarily...