muramidase and Metabolism--Inborn-Errors

An 18-year-old boy showed childhood onset of mental retardation, neurogenic muscle atrophy with hyperreflexia, Marfan-like features, multiple epiphyseal dysplasia, increased urinary excretion of dermatan sulfate, and decreased lysosomal enzyme activities in beta-galactosidase, beta-glucuronidase, and N-acetyl-beta-D-glucosaminidase. This case may be a new syndrome, the combination of neurogenic muscle atrophy with lysosomal enzyme deficiencies.

Topics: Adolescent; Diagnosis, Differential; Humans; Intellectual Disability; Leukocytes; Male; Metabolism, Inborn Errors; Mucopolysaccharidoses; Muramidase; Muscular Atrophy; Reflex, Abnormal; Syndrome

To correct a genetic defect, it would not be enough, say, to inject the missing enzyme, since the body's immune defenses would rapidly destroy it. A "Trojan horse" is needed to evade immune surveillance. The evolution of such an approach is described, as well as how it has been used to "cure" Tay-Sachs disease in culture, utilizing immunoglobulin-disguised liposomes to bring hexosaminidase A to deficient cells.

Topics: Animals; Cells, Cultured; Cytoplasm; Disease Models, Animal; Enzyme Therapy; Genetic Engineering; Hexosaminidases; Humans; Immunoglobulins; Leukocytes; Lipidoses; Liposomes; Lysosomes; Metabolism, Inborn Errors; Muramidase; Peroxidases; Phagocytes; Sharks

Costal and auricular cartilage obtained from mutant rabbits exhibiting lysozyme deficiency has been found to be identical to similar tissue from control animals in a variety of biochemical parameters. These data seriously question the putative role of lysozyme as a structural component of cartilage.

Topics: Age Factors; Animals; Body Water; Cartilage; Ear, External; Hexoses; Hydroxyproline; Metabolism, Inborn Errors; Muramidase; Organ Specificity; Rabbits; Ribs; Uronic Acids

A genetic disorder of rabbits consisting of a deficiency of the enzyme lysozyme is characterized. The condition appears to be inherited as an autosomal recessive trait. Most of the tissues of lysozyme-deficient rabbits including bone marrow, liver, lung. spleen and bone had levels of lysozyme which were 1% or less of the levels in the corresponding tissues of normal rabbits when measured with the lysoplate method. Levels of lysozyme in the kidney and serum were 6% of controls, but the thymus of the lysozyme-deficient rabbits had normal levels of the enzyme. All leukocytes of the lysozyme-deficient rabbits were negative for lysozyme when examined by a histobacterial technic. No morphologic lesions could be detected in any of the tissues of the lysozyme-deficient rabbits. Although several species of animals have been reported to be lysozyme deficient, this appears to be the first report of lysozyme deficiency occurring as a mutant condition. It is suggested that these mutant rabbits may be useful as a resource for experiments designed to delineate the biologic role of lysozyme.

Topics: Animals; Biological Assay; Bone and Bones; Bone Marrow; Kidney; Leukocytes; Liver; Lung; Male; Metabolism, Inborn Errors; Micrococcus; Muramidase; Mutation; Pedigree; Rabbits; Spleen

Topics: Adolescent; Adult; Agranulocytosis; Alkaline Phosphatase; Female; Humans; Leukocytes; Metabolism, Inborn Errors; Muramidase; Pedigree