Search PubMed⌕ Search

Biomedical subjects

K Sahashi

Publications and source records attributed to K Sahashi.

94 records · Page 6Linked to original sources

Immunohistochemical demonstration of beta-enolase in human skeletal muscle.

We have localized beta-enolase activity in human skeletal muscle fiber using the immunohistochemical method (two-step method). The first immunoreagent was rabbit anti-human beta-enolase serum raised in New Zealand white rabbit, and the second was peroxidase conjugated staphylococcal protein A. The immunohistochemical reaction for beta-enolase was noted higher in type 2 fiber, which demonstrates the low oxidative and high glycolytic enzyme activity, than in type 1 fiber.

Histocytochemistry↗

Ultrastructural localization of immune complexes (IgG and C3) at the end-plate in experimental autoimmune myasthenia gravis.

Rats immunized with purified torpedo acetylcholine receptor (AChR) plus adjuvants developed chronic experimental autoimmune myasthenia gravis (EAMG) after day 28. Forelimb muscles from EAMG rats 29 to 103 days after immunization and from control animals were used for the ultrastructural localization of IgG and C3. IgG was demonstrated with rabbit anti-rat IgG followed by treatment with peroxidase-labeled staphylococcal protein A; and C3 with peroxidase-labeled rabbit anti-rat C3, or with unlabeled rabbit anti-rat C3 followed by peroxidase-labeled protein A. In EAMG rats both IgG and C3 were localized on the terminal expansions of the junctional folds, where AChR is known to be located, and on detached, degenerated parts of the folds in the synaptic space. Background staining was negligible. The findings provide unambiguous evidence for a destructive autoimmune reaction involving the postsynaptic membrane in EAMG, implicate the complement system in this reaction and show that detachment of the tips of the junctional folds is one way by which immune complexes, and AChR, are eliminated from the postsynaptic membrane. The immuno-electron microscopic findings in chronic EAMG closely resemble those described in human myasthenia gravis.

Animals↗

[Clinico-pathological analysis of vesiculotubular myopathy of adult onset].

The patient was a 50-year-old house wife. There were complicated consanguineous marriages in the family tree. Since 30 years of age, she had suffered from progressive limb muscle weakness, but without myalgia and myasthenia. At present, she was wheelchair-bound. Physical examinations showed obesity, congenital livedo racemosa, epicanthus palpebrae and left renal defect. Neurologically, facial, anterior cervical, and iliopsoas muscles were well preserved, but others were severely involved. Laboratory examinations revealed mildly elevated myogenic serum enzymes, and myogenic changes on needle EMG. In her muscle biopsy from the left rectus femoris muscle, there were no inflammatory changes, but marked variations of the fiber size as well as adipose tissue replacement were recognized. Strickingly, basophilic masses located in the center of the sarcoplasm were present in about 10% of the fibers. Histochemically, the masses were present in both type 1 and 2 fibers, and exhibited almost similar stained patterns to the tubular aggregates, but were dystrophin-, GRP78- and clathrin-positive. Under electron microscopy, the masses consisted of aggregates of the vesiculotubular structure, measuring approximately from 60 nm to more than 6 microns in diameter, which were continuous with T system/sarcoplasmic reticulum and were clearly segregated from myofilaments. This is a chronic progressive muscular disorder of adult onset with the peculiar pathological finding of vesiculotubular structure.

Age of Onset↗