Medical Conditions Dictionary

An autoimmune disorder mainly affecting young adults and characterized by destruction of myelin in the central nervous system. Pathologic findings include multiple sharply demarcated areas of demyelination throughout the white matter of the central nervous system. Clinical manifestations include visual loss, extra-ocular movement disorders, paresthesias, loss of sensation, weakness, dysarthria, spasticity, ataxia, and bladder dysfunction. The usual pattern is one of recurrent attacks followed by partial recovery (see MULTIPLE SCLEROSIS, RELAPSING-RE;MITTING), but acute fulminating and chronic progressive forms (see MULTIPLE SCLEROSIS, CHRONIC PROGRESSIVE) also occur. (Adams et al., Principles of Neurology, 6th ed, p903)

A group of diseases marked by autosomal recessive inheritance and accumulation of sphingomyelin in cells of the RETICULOENDOTHELIAL SYSTEM. They are divided into 5 subtypes: A-E. Type A (classic infantile form) is caused by a deficiency of SPHINGOMYELIN PHOSPHODIESTERASE and presents at age 6-12 months with progressive hepatosplenomegaly and neurologic deterioration. Type B (non-neuronopathic form) presents in childhood with hepatosplenomegaly and pulmonary infiltrates. Type C (chronic neuronopathic form) is caused by defective intracellular cholesterol transport and is divided into severe infantile, late infantile, juvenile, and neonatal hepatitis forms. Type D (Nova Scotian Variant) is phenotypically similar to type C. Type E is an adult non-neuronopathic form. (From Menkes, Textbook of Child Neurology, 5th ed, pp101-4)

A group of diseases marked by autosomal recessive inheritance and accumulation of sphingomyelin in cells of the RETICULOENDOTHELIAL SYSTEM. They are divided into 5 subtypes: A-E. Type A (classic infantile form) is caused by a deficiency of SPHINGOMYELIN PHOSPHODIESTERASE and presents at age 6-12 months with progressive hepatosplenomegaly and neurologic deterioration. Type B (non-neuronopathic form) presents in childhood with hepatosplenomegaly and pulmonary infiltrates. Type C (chronic neuronopathic form) is caused by defective intracellular cholesterol transport and is divided into severe infantile, late infantile, juvenile, and neonatal hepatitis forms. Type D (Nova Scotian Variant) is phenotypically similar to type C. Type E is an adult non-neuronopathic form. (From Menkes, Textbook of Child Neurology, 5th ed, pp101-4)

Mild to fulminant necrotizing vaso-occlusive retinitis associated with a high incidence of retinal detachment and poor vision outcome.

Nonlymphocytic leukemia in which 20-30% of the bone marrow or peripheral blood cells are of megakaryocyte lineage. Myelofibrosis or increased bone marrow reticulin is common.

A myeloproliferative disorder characterized by neoplastic proliferation of erythroblastic and myeloblastic elements with atypical erythroblasts and myeloblasts in the peripheral blood.

Progressive, malignant disease of the myeloid tissue in which the granular, polymorphonuclear leukocytes and their precursors predominate.

Progressive, malignant disease of the myeloid tissue in which the granular, polymorphonuclear leukocytes and their precursors predominate.

Drugs that selectively bind to and activate beta-adrenergic receptors.

A subclass of beta-adrenergic receptors (RECEPTORS, ADRENERGIC, BETA). beta-2 Adrenergic receptors are more sensitive to epinephrine than to norepinephrine and have a high affinity for the agonist terbutaline. They are widespread, with clinically important roles in skeletal muscle, liver, and vascular, bronchial, gastrointestinal, and genitourinary smooth muscle.