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Lipid Storage Disorders: Background, Pathophysiology, Mode of Inheritance Share Feedback Background Lipid storage disorders are a family of diverse diseases related by their molecular pathology. In each disorder, a deficiency of a lysosomal hydrolase is inherited, which leads to lysosomal accumulation of the enzyme's specific sphingolipid substrate. [1, 2] Lipid substrates share a common structure, including a ceramide backbone (2-N-acyl-sphingosine), in which various sphingolipids are derived by substitution of hexoses, phosphorylcholine, or one or more sialic acid residues on terminal hydroxyl groups of the ceramide molecule. Pathways of glycosphingolipid metabolism in both nervous tissue and visceral organs are elucidated, and for each catabolic step, a genetically determined metabolic derangement is identified. [3] Examples of lipid storage disorders include GM1 gangliosidoses, [4] GM2 gangliosidoses, [4] Gaucher disease, sphingomyelinase deficiency or Niemann-Pick disease (NPD

This JAMA Insights explains how recent studies have clarified the role of lipids and lipoproteins in the development of atherosclerotic cardiovascular disease (ASCVD) and led to changes in clinical practice guidelines for the management of dyslipidemia.1 Lipids and Lipoproteins in the Development of ASCVD Cholesterol and triglycerides are the major lipids in humans and are transported in plasma by lipoproteins. A lipoprotein is composed of cholesterol, triglycerides, and a single apolipoprotein B100 molecule (apoB) when secreted into plasma by the liver, and is referred to as a very low-density lipoprotein (VLDL). The triglycerides are rapidly removed by the enzyme lipoprotein lipase and used for energy consumption and storage. As triglycerides are being progressively removed, the lipoprotein is referred to as a VLDL remnant particle. After most of the triglycerides have been removed, the lipoprotein becomes denser and is referred to as a low-density lipoprotein (LDL). However, it is i

Nasal and Septal Fractures: Practice Essentials, Epidemiology, Etiology Share Feedback Practice Essentials Nasal fractures are the most common types of facial fractures; however, they are often unrecognized and untreated at the time of injury. Its central position and anterior projection on the face predisposes the nose to traumatic injury. Studies have shown that most nasal fractures involve the septum, which can be an obstacle to successful reduction. Fractures can be classified as open or closed, depending on the integrity of the mucosa. Prompt identification and management of the injury in the early postinjury period is imperative to avoid the potential complications of nasal and septal fractures. Confirming that septal hematoma is not present is crucial to avoid further compressive damage to native tissue and dangerous infectious complications. Longer-term follow-up allows the surgeon to assess for both early and late sequelae of injuries to the nasal complex. Surgical interventio