NM Disease Flashcards
Myosin ATPase pH 9.8
Type 1 fibers (slow twitch) light staining
Type 2 fibers (fast twitch) dark staining
Myosin ATPase incubation at pH 4.3
Type 1 fibers dark staining
Type 2A and 2B fibers light staining
Type 2C fibers dark staining
NADH dehydrogenase
Stains mitochondria and sarcoplasmic reticulum
Gomori modifies trichromatic
Stain for nucleuoproteins and lipoproteins; nuclei and aggregates of mitochondria and SR stain brilliant red. Stain of choice for demonstrating nemaline rods and ragged red fibers. Excellent stain for evaluation of nerve fiber morphology
Periodic acid Schiff
External basal lamina, glycogen and myelin. Good for detection of glycogen storage disorders
Oil red O
Stains triglyceride fats; good for staining intramyofiber lipid stores and detection of lipid storage disorders
Protein A-peroxidase
Detection of Ig at NMJs, ANA, anti-atrial antibodies
Drug-induced myopathies
D-penicillamine, cimetidine, TMS, tapazole in cats
Endocrine myopathies
Characterized by generalized atrophy of type 2 muscle fibers. A shift to type 1 fiber predominance, nemaline rods, and PAS positive deposits may be observed in hypothyroidism. Lobulated fibers may be found in chronic Cushings
Cytochrome c oxidase deficiency
Ragged red fibers, excessive lipid droplets
OES
Pyruvate dehydrogenase phosphate 1 deficiency
Ragged red fibers and excessive lipid droplets
Clumber, Sussex spaniels
Disorders of lipid metabolism
Oil red O lipid deposits in muscle
Acquired fatty acid oxidation defect in pasture fed horses
Primary or secondary carnitine deficiency
Unclassified in wire-haired pointing griffons
Disorders of glycogen metabolism
PAS positive deposits in muscle biopsy Myophosphorylase deficiency - Charolais cattle Phosphofructokinase deficiency- springer spaniels, cocker spaniels Polyglucan storage (ladies) - mini wire haired dachshunds Polysaccharide storage - quarter horse, warmblood, draft breeds
Dystrophin deficiency
X-linked but affected females reported
Golden retriever, Rottweiler, GSHP, Irish terrier, Samoyed, miniature schnauzer, Brittany spaniels, rat terrier, PWC, Labrador retrievers, Japanese spitz, CKCS
Hypertrophic MD in some DSH
Laminin a2 deficiency
Major component of basal lamina that surrounds each muscle fiber
One of the extra cellular ligand for the dystrophin-associated glycoprotein complex that links the extra cellular matrix and contributes to the stability of the muscle basement membrane
Sarcoglycan deficiency
Part of the dystrophin glycoprotein complex which stabilizes myofiber membranes during contraction
Chihuahua, cocker spaniel, Boston terrier- epsilon subunit of sarcoglycans, Doberman
Collagen VI deficiency
Multiple limb deformities in Labrador retriever at 5mo; weakness at 6wo in Landseer dogs
Dx via muscle bx
Myotonia congenital
Chow chow, miniature schnauzer, staffordshire terrier, Australian cattle dog, domestic cats
MS/ACD/cats - mutations in skeletal muscle voltage-dependent chloride channel (CLCN1)
Centronuclear myopathy in Labrador retrievers
PTPLA mutation
Genetic test available
X-linked myotubular myopathy
Mutations in myotubularin gene (MRM1) in Labrador retrievers and Rottweiler
Identified in Manchester terriers but mutation unknown
Muscle bx still required for characterization in early onset myopathy in breeds w/o genetic test