An autopsy case of chronic progressive external ophthalmoplegia with renal insufficiency.

An autopsy of a 44-year-old Japanese woman with mitochondrial cytopathy confirmed the presence of chronic progressive external ophthalmoplegia (CPEO). Immunohistochemistry using antimitochondrial antibody was performed to observe the ultrastructure of the skeletal muscle and renal tissues. The patient was born of consanguineous parents, developed normally, and was of average intelligence. At 22 years of age, the patient noticed hearing loss, and subsequently, over time, developed a progressive generalized muscle weakness, which included limitation of eye movement and ptosis. At age 41, a muscle biopsy was performed using the modified Gomori trichrome method and demonstrated the presence of ragged red fibers. After the evaluation of her results in conjunction with her clinical course, she was diagnosed with CPEO. Renal insufficiency was discovered at age 30, and the patient died at the age of 44 of respiratory failure caused by respiratory muscle weakness and pneumonia. The autopsy revealed fiber size variation within the skeletal muscle, and an antimitochondrial antibody analysis demonstrated the accumulation of mitochondria between the bundles of myofibrils, as well as in subsarcolemmal locations. Ultrastructurally, abnormal mitochondria with disoriented cristae and paracrystalline inclusions were seen. Although no remarkable histological changes were noted in the kidneys, tubular epithelial cells exhibited accumulated abnormal mitochondria, similar to those seen in the skeletal muscle. Because mitochondrial diseases can affect other energy-dependent organs in addition to the skeletal muscle, immunohistochemical examinations employing an antimitochondrial antibody are useful for obtaining further ultrastructural observations that can assist in making a distinct diagnosis of this systemic disorder.

The relationship between carbohydrate intake and glucose tolerance in pregnant women.

OBJECTIVE: We verified whether a misdiagnosis of gestational diabetes mellitus can result in pregnant women when glucose tolerance has deteriorated after a low-carbohydrate meal, and tried to elucidate the mechanism behind the different outcome of the test. STUDY DESIGN: Twenty-seven pregnant women were given directions for their evening meal the day before each of two 75-g oral glucose tolerance tests (OGTT). The evening meal was either a low-carbohydrate meal (carbohydrate, 6.7%; Low), or a high-carbohydrate meal (carbohydrate, 85.7%; High). RESULTS: The OGTT showed that the glucose tolerance was significantly impaired after Low than after High, with a significant increase of fasting plasma non-esterified fatty acids (NEFA) level. Moreover, the insulinogenic index (I-I) after High significantly decreased than that after Low. CONCLUSIONS: The present data suggests that there is a risk of misdiagnosis of impaired glucose tolerance with only one intake of this extremely low-carbohydrate meal on the evening before testing. The decrease of insulin secretion and the activation of glucose-fatty acid cycle may be considered as the mechanism.