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Biomedical subjects

I Higuchi

Publications and source records attributed to I Higuchi.

At least 163 records · Page 9Linked to original sources
PubMed1989

[A study of mitochondrial electron transfer chain in myotonic dystrophy].

Ragged-red fibers (RRFs) are mainly seen in mitochondrial myopathy and related to biochemical defects in electron transfer chain on some occasions. Recently, some papers reported the occurrence of RRFs in the biopsied muscle of myotonic dystrophy (MyD). To examine whether the mitochondrial function is disturbed in MyD, we have studied the biopsied muscles of 12 cases with MyD (10 males and 2 females averaging 38 years of age) morphologically and mainly biochemically. RRFs, ranging from 2--20% of the muscle fibers, were identified in 5 out of 12 cases. On electron microscopy, these fibers had aggregated abnormally enlarged mitochondria with dene bodies, concentrically whirled membranous cristae and paracrystalline inclusions. Clinically, 4 of 5 cases with RRFs had mild to moderate and only 2 of 7 without RRFs had ophthalmoplegia. Bicycle ergometer exercise test showed abnormal increase of lactate/pyruvate ratio in three cases with RRFs. Histochemically, cytochrome c oxidase (CCO) activity was absent selectively in all of the RRFs. Immunohistochemical staining showed the presence of CCO protein by using monoclonal antibody which was specific to CCO subunit IV. Biochemical study with crude muscle extract of 11 cases of MyD showed decreases in NADH dehydrogenase, NADH CoQ reductase, succinate CoQ reductase (SCR), CCO, carnitine actyl transferase activities in most of cases regardless RRFs. To avoid the influence possibly derived from the various stages of muscle degeneration in the biopsied specimens, we calculated the ratio of the enzyme activities compared with succinate dehydrogenase which was located in the electron transfer chain and did not show any statistical difference regardless of RRFs.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Reappearance of embryonic neutral alpha-glucosidase isoenzyme in acid maltase-deficient muscle of Japanese quail.

Two neutral alpha-glucosidase isoenzymes were isolated from the muscle of Japanese quails with late-onset acid maltase deficiency. One isoenzyme is predominantly expressed in embryonic muscle and the other in adult muscle. The time of switching from one to the other of these two neutral alpha-glucosidases was the same as in normal birds. The glycogen content in acid maltase-deficient muscle was not inversely proportional to the amount of embryonic neutral alpha-glucosidase. From the results, we conclude that (i) the transition of neutral alpha-glucosidase from the embryonic to the adult type is not influenced by the disease, and (ii) the embryonic neutral alpha-glucosidase seems not to be directly correlated with glycogen storage in skeletal muscle. In acid maltase-deficient muscle, the activity of the embryonic type began to increase again from 14 days after hatching, and attained a level corresponding to 18% of the total neutral alpha-glucosidase activity at 3 months (P less than 0.025). Its biochemical characteristics were the same as those of the normal embryonic neutral alpha-glucosidase. It should be clarified why the reappearance of the normal embryonic type occurs in acid maltase-deficient adult muscle and whether or not the reappearance of the embryonic neutral alpha-glucosidase represents regenerating muscle.

Animals↗
PubMed1988

Neuroleptic malignant syndrome: caffeine contracture of single muscle fibers and muscle pathology.

The neuroleptic malignant syndrome (NMS) is similar to anesthesia-induced malignant hyperthermia (MH) in three major clinical features: hyperthermia, muscular rigidity, and myoglobinuria. In eight cases of NMS, we studied caffeine contracture of single skinned muscle fibers. Sensitivity of the sarcoplasmic reticulum to caffeine was abnormally increased in six of the eight cases. Morphologic studies showed type 2B fiber atrophy in all six cases examined, and there were necrotic fibers in two cases. Since skeletal muscle is affected in NMS, these patients may be susceptible to MH.

Adolescent↗
PubMed1987

The effect of DDB on dystrophic hamsters: an in vivo and in vitro study.

Dimethyl-4, 4'-dimethoxy-5, 6, 5'-6'-dimethylenedioxybiphenyl-2, 2'-dicarboxylate (DDB) is a synthetic analogue of Schizandrin C, an active compound isolated from a Chinese herb, Fructus schizandrae. We administered this compound to dystrophic hamsters in vivo for 31 days. This led to a 61% reduction of the calcium content, an 86% reduction of the area of calcium deposits, and a 52% reduction of the area of necrosis of cardiac muscle. However, skeletal muscle necrosis was not significantly improved. No clear change in plasma creatine kinase (CK) was observed. In an in vitro incubation study, the rate of CK release and tetanus tension of the extensor digitorum longus muscle of dystrophic hamsters were not substantially changed by the addition of DDB. This study suggests that DDB has some effect on cardiac necrosis, and that it might be useful for treatment of the cardiac involvement in patients with muscular dystrophy or other conditions with accompaning Ca accumulation.

Animals↗
PubMed1987

Acid maltase deficiency in the Japanese quail; early morphological event in skeletal muscle.

The skeletal muscle of Japanese quails with acid maltase deficiency (AMD) was studied morphologically at various developmental stages, from the 16th embryonal day up to 3 months after hatching. Membrane-bound glycogen particles began to appear in the affected skeletal muscle at the 16th embryonal day. In normal embryonic muscles, a certain amount of free glycogen particles was observed but they were not membrane-bound. Therefore, this is the earliest morphological event in the muscle of Japanese quails with AMD. In muscle at 3 weeks after hatching, the initial focal degeneration of myofibrils was recognizable but it was not associated with autophagic vacuoles. Quails with AMD developed muscle weakness and difficulty in lifting their wings at about 3 months after hatching: then numerous autophagic vacuoles were present. The formation of large autophagic vacuoles followed by fiber loss and fatty replacement seemed to contribute to the progressive muscle weakness. The study of Japanese quail with AMD will greatly facilitate the elucidation of the pathogenetic mechanism and is also a useful model for therapeutic trials in human AMD.

Animals↗
PubMed1986

High AMP deaminase activity in rimmed vacuoles of skeletal muscle.

Localized high AMP deaminase activity was found in the rimmed vacuoles of skeletal muscles in acid maltase deficiency, distal myopathy with rimmed vacuole formation, and experimental chloroquine myopathy on histochemical staining. Acid phosphatase activity was also increased in and around these vacuoles, but the vacuoles were negative for other histochemical stainings such as with NADH-tetrazolium reductase, ATPase and phosphorylase. These findings suggest that AMP deaminase is bound to membranous components in addition to myosin in skeletal muscle.

AMP Deaminase↗
PubMed1981

Breast cancer concurrent with hyperthyroidism: a case report.

A case of breast cancer concurrent with hyperthyroidism was reported and the relation between breast cancer and thyroid dysfunction was reviewed. It has been frequently suggested that the incidence of breast cancer is decreased in patients with hyperthyroidism and breast cancer coincidental with hyperthyroidism is rare.

Adult↗
PubMed1976

Interpretation of distribution coefficients of p-alkylpyridines by a modified regular solution theory.

The hypothetical hexadecane-octane distribution coefficients for the alkylpyridines were deduced from the corresponding oil-water distribution data. The values were analyzed by a modified regular solution theory. A good correlation was noted by including the Flory-Huggins entropy factor in the calculation and by considering the deviation from the geometric mean assumption.

Chemical Phenomena↗
PubMedDate not supplied

Trial of a cysteine proteinase inhibitor, EST, in experimental chloroquine myopathy in rats.

The administration of 50 mg/kg/day of chloroquine to rats for 8 weeks produced the chloroquine myopathy characterized by autophagic vacuole formation and increases in lysosomal enzymes, especially cathepsins B & L. Coadministration of 10 mg/kg/day of a potent cysteine proteinase inhibitor, EST, and chloroquine prevented the induction of the chloroquine myopathy. Rats already suffering from the chloroquine myopathy were treated with 10 mg/kg/day of EST together with chloroquine injections for 5 weeks and also recovered remarkably from the myopathy. Thus, EST may be beneficial for myopathies associated with autophagic vacuoles.

Animals↗
PubMedDate not supplied

Immunohistochemical localization of AMP deaminase in rimmed vacuoles in human skeletal muscle.

High AMP deaminase reactivity was detected in the rimmed vacuoles in skeletal muscles in adult onset acid maltase deficiency and distal myopathy with rimmed vacuole formation histochemically as well as immunohistochemically. Acid phosphatase activity was positive but myosin ATPase activity was negative in the vacuoles. AMP deaminase found in rimmed vacuoles does not seem to be associated with myosin but is possibly bound to lysosomes or other related organelles in accordance with the proliferation of autophagic vacuoles.

AMP Deaminase↗