Because this protein is also present in oligodendrocytes, demyelination can appear in the CNS.Schwann cells create the myelin sheath, by wrapping its plasma membrane around the axon.Neurons, Schwann cells, and fibroblasts work together to create a functional nerve. Schwann cells and neurons exchange molecular signals by gap junctions that regulate survival and differentiation.Demyelinating Schwann cells causes abnormal axon structure and function. They may cause axon degeneration, or they may simply cause axons to malfunction.The myelin sheath allows nerve cells to conduct signals faster. When the myelin sheath is damaged, nerve signals are slower, and this can be measured by a common neurological test, electromyography. When the axon is damaged, though, this results in a reduced compound muscle action potential.GARS1-Related Axonal Neuropathy
CMT2 types are typically referred to as axonal neuropathies due to the axonal degeneration observed. CMT2 types are a result of damage to the nerve axons rather than damage to the myelin sheath (as is the case with CMT1). Damaged axons cause slowed transmission of signals to the muscles and brain, causing symptoms including muscle atrophy, weakness, decreased sensitivity, and foot deformity. Symptoms of CMT2 types typically appear between the ages of 5 and 25. CMT2D is one of 31 Charcot-Marie-Tooth type 2 forms 1 and is only diagnosed if sensory deficits (such as loss of sensation due to the degradation of sensory axons) are observed along with motor deficits; otherwise, distal hereditary motor neuropathy type V is diagnosed. It is unknown why sensory involvement is so varied between GARS1 neuropathy patients.
Mafenide (INN; usually as mafenide acetate, trade name Sulfamylon) is a sulfonamide-type medication used as an antibiotic. It was approved by the FDA in 1948. Uses
Mafenide is used to treat severe burns. It is used topically as an adjunctive therapy for second- and third-degree burns. It is bacteriostatic against many gram-positive and gram-negative organisms, including Pseudomonas aeruginosa. Some sources state that mafenide is more appropriate for non-facial burns, while chloramphenicol/prednisolone or bacitracin are more appropriate for facial burns. Mechanism of action
Mafenide works by reducing the bacterial population present in the avascular tissues of burns and permits spontaneous healing of deep partial-thickness burns. Adverse reactions
Adverse reactions can include superinfection, pain or burning upon application, rash, pruritus, tachypnea, or hyperventilation. Mafenide is metabolized to a carbonic anhydrase inhibitor, which could potentially result in metabolic acidosis. Drug interactions
There are no significant interactions. Contraindications
Mafenide is contraindicated in those with sulfonamide hypersensitivity or renal impairment. Dosage
For use as adjunctive therapy for second- and third-degree burns to prevent infection, adults and children should apply topically to a thickness of approximately 1.6 mm to cleaned and debrided wound once or twice per day with a sterile gloved hand. The burned area should be covered with cream at all times. References
External links
Mafenide information on RxList