Hiroshi Nishino

Lupus Erythematosus-like Syndrome with Selective Complete Deficiency of C1q

A 37-year-old Japanese man in previously good health was hospitalized because of swelling of the auricles had discoid erythema of the face. Clinical and laboratory findings satisfied the diagnostic criteria for systemic lupus erythematosus proposed by the American Rheumatism Association. However, serologic studies showed weakly positive antinuclear factor and absence of anti-DNA antibody and lupus erythematosus cells. A striking abnormality was the total absence of serum hemolytic complement activity (CH50). Further studies showed selective complete deficiency of C1q, a subunit of the first component of complement (C1). This is the first reported case of lupus erythematosus-like syndrome with selective complete deficiency of C1q.

Clinical, pathological, and genetic features of limb‐girdle muscular dystrophy type 2A with new calpain 3 gene mutations in seven patients from three Japanese families

We report on the clinical, pathological, and genetic features of 7 patients with limb‐girdle muscular dystrophy type 2A (LGMD2A) from three Japanese families. The mean age of onset was 9.7 ± 3.1 years (mean ± SD), and loss of ambulance occurred at 38.5 ± 2.1 years. Muscle atrophy was predominant in the pelvic and shoulder girdles, and proximal limb muscles. Muscle pathology revealed dystrophic changes. In two families, an identical G to C mutation at position 1080 the in calpain 3 gene was identified, and a frameshift mutation (1796insA) was found in the third family. The former mutation results in a W360R substitution in the proteolytic site of calpain 3, and the latter in a deletion of the Ca2+‐binding domain.

Experimental glycerol myopathy: a histological study.

SummaryHistopathological changes induced by the intramuscular injection of glycerol were studied in the muscle fibers of rabbits. Fifteen minutes after the injection of 1 ml of 50% (v/v) glycerol, hypercontraction of fibers, disruption of the plasma membrane, and invasion of lanthanum into the sarcoplasm were observed. Between 12 and 24 h after the injection, more extensive pathological changes were seen which included: variation in fiber size; degeneration and necrosis of muscle fibers; hypercontraction of fibers by light microscopy; disruption of the plasma membrane by electron microscopy; vacuolar changes; hypercontraction of myofibrils, and selective loss of Z-bands. Between 7 and 14 days after glycerol injection, extensive regenerative changes were seen. The degenerative changes were similar to those seen in muscle in Duchenne muscular dystrophy, suggesting that a similar mechanism may be involved in the two conditions, so that experimental glycerol myopathy could be a good model for pathophysiological studies on Duchenne muscular dystrophy.

In situ hybridization of myoglobin mRNA: results on the skeletal muscles of normal subjects and patients with neuromuscular diseases

The intracellular localization of myoglobin(Mb) mRNA in the skeletal muscles of normal subjects and patients with Duchenne muscular dystrophy(DMD) or amyotrophic lateral sclerosis(ALS) was examined by in situ hybridization using a biotin-labeled cDNA probe. In cross sections of normal muscles, Mb mRNA signals were demonstrated to be diffusely distributed as granular reaction products throughout the sarcoplasm, and in longitudinal sections the products were observed preferentially on the A-band. In DMD or ALS muscles, the distribution of granular mRNA signals showed some similarities with that in normal muscles, although degenerated fibers revealed a heterogenous distribution of the signals. In DMD muscles, the optical density(OD) of stained signal was higher in non-atrophic fibers and lower in atrophic fibers than in normal muscles. In ALS muscles, the OD was lower than in normal muscles. These results suggest that Mb mRNA is distributed preferentially on the A-band of the muscle fibers, and that in diseased muscle fibers Mb synthesis is affected by pathological changes.

Skeletal muscle pathology of mannosidosis in two siblings with spastic paraplegia

SummaryDeficiency of α-d-mannosidase was found in two siblings with muscle weakness and spastic paraplegia. A biopsy of the vastus lateralis muscle was studied by light and electron microscopy. Cryostat sections showed mild fiber size variation but no necrosis. Semithin Epon sections revealed many vacuoles in the muscle cells and fibroblasts. Electron microscopy showed that the vacuoles, presumably lysosomal, had a single limiting membrane and contained finely granular or granulo-reticular material, membranous structures, and electron-dense ovoids. The vacuoles were identical with those in lymphocytes and other cells of patients with mannosidosis. Disorganization of sarcomere alignment and widening of intermyofibrillar spaces were also observed. Deficiency of α-d-mannosidase is considered to cause slowly progressing degeneration of muscle fibers.

Isozyme pattern of leukocyte α-d-mannosidase in patients with mannosidosis

SummaryThe isozyme patterns of leukocyte α-d-mannosidase in two sisters with mannosidosis, their parents and a patient with trisomy 19 were studied. The isozyme pattern of liver mannosidase of a normal subject was also studied. In the patients with mannosidosis the neutral isozyme (isozyme C or fraction C) was present, but the acidic isozymes (isozyme A and B or fraction A and B) were not detectable. In their parents the activity of the acidic isozymes was one-third of the normal activity. These findings suggest that the patients are homozygous and their parents are heterozygous in terms of deficiency of acidic isozymes. In the patients with trisomy 19, the activity of α-d-mannosidase was 4.9 times the upper limit of the normal value, while the levels of other lysozomal enzymes were normal. This increase was mainly due to increases of the A and B isozymes of mannosidase. This finding suggests that the gene encoding acidic isozymes, but not that encoding the neutral isozyme, is located on chromosome 19. The isozyme pattern of α-d-mannosidase differed in different tissues of normal subjects, and the difference in severity of lesions in different organs of the patients with mannosidosis could be explained by differences in the isozyme patterns of the enzyme in these organs.