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Biomedical subjects

T Yamano

Publications and source records attributed to T Yamano.

At least 127 records · Page 7Linked to original sources
PubMed1991

[Enzyme immunoassay of urinary apolipoprotein H and its application for detecting incipient diabetic nephropathy].

In order to elucidate the clinical significance of urinary apolipoprotein H (Apo H), otherwise known as beta 2-glycoprotein I, we first developed a non-competitive enzyme immunoassay (EIA) to quantify urinary Apo H levels. The measurable range of this assay was about 2 ng/ml to 100 ng/ml. The intra- and inter-assay coefficients of variation were 2.0 to 4.7% and 8.3 to 17.0%, respectively. These results indicated that this assay had high sensitivity and good reproducibility, and that it was useful for clinical study. We then determined urinary Apo H levels in 24 normal subjects and 36 diabetics using this assay. The mean urinary Apo H index (urinary Apo H/cr ratio), in 20 patients without proteinuria, who were regarded as patients without nephropathy, was 569 +/- 560 (X10(-3) mg/g.cr) and significantly higher than in normal subjects (252 +/- 147, p less than 0.01). The mean urinary Apo H index in 16 patients with overt proteinuria was 1,507 +/- 3,701 and also higher than in normal subjects (p less than 0.01). These results taken collectively indicate that urinary Apo H level using the EIA may be a new sensitive marker for detecting minor change of glomerular basement membrane in diabetics.

Adult↗
PubMed1991

[Neural plasticity after neonatal hypoxic and ischemic insult in rats].

Rats with huge porencephaly occupying the left cerebral hemisphere were used for this study. Porencephaly was caused experimentally by the ligation of the left common carotid artery and subsequent hypoxic exposure at the age of 7 days. A large band of horseradish peroxidase (HRP) positive fibers was found crossing at the pyramidal decussation to reach the contra-lateral corticospinal tract and the deeper part of the funiculus, in the cervical cord. However, a small band of HRP positive fibers was noticed to reach the ipsilateral corticospinal tract without crossing at the pyramidal decussation. This result indicates that the developing pyramidal neurons in the right hemisphere carry the plasticity even after suffering from considerable hypoxia.

Animals↗
PubMed1990

Rate enhancement of the electron transfer of the adrenodoxin-adrenodoxin reductase system by inorganic and nucleotide phosphates.

Phosphate and pyrophosphate increased the rate of reduction of adrenodoxin by NADPH-adrenodoxin reductase and NADPH, pyrophosphate being one order more effective than the former. However, the cytochrome c reduction by the electron transport system was inhibited in the presence of inorganic (pyro)phosphate. On the other hand, ADP and ATP enhanced the rates of reduction of both adrenodoxin and cytochrome c through adrenodoxin by the electron transport system. GTP also enhanced the rate of reduction of cytochrome c by this system, whereas AMP showed no appreciable enhancement. These inorganic and nucleotide phosphates did not affect the rate of ferricyanide reduction by the reductase.

Adenosine Triphosphate↗
PubMed1990

Hepatotoxicity of geniposide in rats.

The hepatotoxic effects of geniposide were investigated in rats. Increases in serum alanine aminotransferase and aspartate aminotransferase activities as a result of oral administration of 320 mg geniposide/kg body weight were suppressed when geniposide was administered ip or when the rats were pretreated with chloramphenicol. The non-protein sulphydryl content of the liver 4 hr after oral administration of geniposide decrease in a dose-dependent manner. Genipin, the aglycone of geniposide, had a marked reactivity with sulphydryl groups of glutathione and cysteine in vitro. The hepatotoxic effects of ip administration of genipin at a dose of 80 mg/kg body weight were comparable with those of oral administration of geniposide at a dose of 320 mg/kg. Buthionine sulphoximine pretreatment enhanced the toxicity of geniposide, while cysteine pretreatment completely suppressed it. These results suggest that the conversion of geniposide to genipin is causally related to the hepatotoxicity of geniposide and that hepatic non-protein sulphydryls are important in modulating the toxicity.

Administration, Oral↗
PubMed1990

Electron microscopic study on the homozygote (Ml/Ml) of the macular mutant mouse.

The macular mouse is a mutant mouse with a defect in copper transport and an X-linked recessive inheritance. Its hemizygote (Ml/y) is considered to be an appropriate model fo Menkes kinky hair disease (MKHD). In this study, homozygote (Ml/Ml) were bred by coupling CuCl2-treated Ml/y with heterozygote (Ml/+). Both Ml/Ml and Ml/y die around day 15 of age. However, treatment with CuCl2 enables them to live until adulthood. The brains of Ml/Ml were chronologically examined by light and electron microscopy. In the non-treated Ml/Ml, abnormal mitochondria increased in number in the cerebral cortical neurons and in the cerebellar Purkinje cells from day 7 to 14 of age. In the treated Ml/Ml, the administration of CuCl2 improved the abnormality of the mitochondria in the cerebrum by day 20, but those in the Purkinje cells remained until day 60. Flattened cisterns and intracytoplasmic inclusions were also observed in the Purkinje cells of treated Ml/Ml. These ultrastructural changes were quite similar to those observed in the Ml/y. Our mutant mice (treated Ml/Ml), when they are coupled with treated Ml/y, can give birth to offspring, all of which will be genetically Ml/y or Ml/Ml. These fetal mice will be very helpful for studying the pathological and biochemical condition of prenatal MKHD.

Animals↗
PubMed1990

Reorganization of the corticospinal tract following neonatal unilateral cortical ablation in rats.

The corticospinal tract in the rat after neonatal ablation of the unilateral cerebral cortex was studied morphologically and histochemically using the retrograde and antegrade horseradish peroxidase (HRP) tracing methods. The normal corticospinal tract in the lumbar cord was composed of a number of small and some large axons. In the atrophic corticospinal tract related to the ablated cerebral cortex, the small axons were decreased in number two weeks after the operation. However, new myelinated small axons appeared around day 28 and their diameters increased gradually from after day 56 to day 84. The original large axon in the atrophic corticospinal tract was much more increased in size than that in the corticospinal tract of the non-operated-on control. When HRP was injected into the left cervical cord of the adult rat whose right cerebral cortex had been ablated during the neonatal period, a considerable number of HRP-labeled neurons was seen in the healthy left cerebral cortex. When the corticospinal tract was traced antegradely by injecting HRP into the healthy left cerebral cortex, an aberrant corticospinal tract reaching into the ipsilateral dorsal funiculus was observed. These results give a morphological basis for the well known fact that children who have had brain damage during the neonatal period and early infancy have the capacity for recovery of motor function.

Animals↗
PubMed1990

Clinical and EEG studies on complex partial seizure in children.

In 18 (40%) of 45 patients with CPS, paroxysmal discharges were hard to be found on their interictal EEG examinations. These patients were, however, not different from the other 27 patients with paroxysmal discharges on EEG as for the onset, prognosis for attack, complication of generalized tonic-clonic seizure and febrile convulsion, family history and adaptation to society.

Adolescent↗
PubMed1990

[Acute renal failure in a case of paroxysmal nocturnal hemoglobinuria--a review of literature in Japan].

A case of paroxysmal nocturnal hemoglobinuria (PNH) associated with acute renal failure (ARF) is described. A 57-year-old female, who had been diagnosed as having PNH in 1983 at Kochi Medical School, was admitted to our hospital in April 1989, because of ARF with dark urine after a common cold. Hemodialysis was performed 5 times for ARF, and after almost completely recovering from ARF, she was discharged. The renal biopsy showed the deposition of hemosiderin in the proximal tubular cells. We surveyed fourteen case reports of PNH associated with ARF in Japan including our case. Ten cases developed ARF after infection causing hemolytic attack. Twelve of 14 cases were treated by hemodialysis and 13 cases were reversible. The histopathology of their renal biopsies revealed the deposition of hemosiderin in the proximal tubular cells in six of seven cases and tubular necrosis in three cases. These data showed that hemolytic attack and dehydration related to infection facilitated the induction of ARF.

Acute Kidney Injury↗
PubMed1989

Rate enhancement of the electron transfer the adrenodoxin-adrenodoxin reductase system by dicarboxylic acids.

The rate of electron transport in the cytochrome P-450 system in adrenocortical mitochondria was studied with purified adrenodoxin reductase, adrenodoxin and cytochrome c. Oxaloacetate enhanced the rate at concentrations of less than 1 mM; malate, succinate and fumarate enhanced the rate to a lesser extent; and pyruvate and alpha-ketoglutarate had no appreciable effect. The rate enhancement was observed when the reagents were preincubated with adrenodoxin, but not with adrenodoxin reductase. Rate enhancement was also evident when the rate limiting step was at adrenodoxin in the electron transport system.

Adrenodoxin↗
PubMed1989

Plasma apolipoprotein H (beta 2-glycoprotein I) phenotype frequencies in a Japanese population.

We determined plasma apolipoprotein H (beta 2-glycoprotein I) levels in 300 healthy adult individuals and evaluated the frequencies of the BgN and BgD alleles in a Japanese population. These results were then compared with the previous reports. The plasma apo H levels in the subjects showed bimodal distribution: 274 subjects were in the range 15.6-33.2 mg/dl and were considered to be homozygous for BgN (phenotype NN), and 26 subjects were found in the range 9.6-14.8 mg/dl and were presumably heterozygous for BgN and BgD (phenotype ND). In this study, no sample below 5 mg/dl (phenotype DD) was found. Mean plasma apo H levels in NN and ND groups were 22.1 +/- 1.6 mg/dl and 12.5 +/- 1.6 mg/dl, respectively. The gene frequencies of BgN and BgD in a Japanese population were 0.957 and 0.043, respectively. These results were similar to gene frequencies of BgN and BgD in Caucasoids.

Gene Frequency↗
PubMed1989

Relationship between hepatic glutathione content and carbon tetrachloride-induced hepatotoxicity in vivo.

The relationship between carbon tetrachloride (CCl4)-induced hepatotoxicity and hepatic glutathione (GSH) content was investigated in fed and fasted rats. The elevation of serum glutamic-pyruvic transaminase (GTP) activity by CCl4 treatment was enhanced by fasting. Although the hepatic GSH content fo 12-hour-fasted rats was higher than that of fed rats determined at 6 p.m., the serum GPT activity of the former was higher than that of the latter. Starvation had no effect on the activities of hepatic glutathione peroxidase (GSH-Px) and glutathione reductase (GR). The results suggest that the potentiation of hepatic injury by CCl4 cannot be related to hepatic GSH content.

Alanine Transaminase↗
PubMed1989

Golgi study on the homozygote (Ml/Ml) of macular mutant mouse.

The macular mutant mouse shows X-linked recessive inheritance and its hemizygote (Ml/y) is considered to be an appropriate model of Menkes kinky hair disease (MKHD). In this study the homozygote (Ml/Ml) was bred by coupling CuCl2-treated Ml/y with Ml/+ and was clinically and neuropathologically examined. The Ml/Ml had white fur color and curly whiskers from day 3, showed ataxia and tonic seizure on day 8 and gradually lost weight after day 10. It died with severe emaciation around day 15. These clinical features were improved by CuCl2 injection. Quantitative analysis showed that the dendritic arborization of the pyramidal cell in the treated Ml/Ml was delayed on days 14, 20, 30, 45 and 90 in comparison with that of the age-matched +/y. In the cerebellum of the Ml/Ml on day 14, some of the Purkinje cells showed abnormal changes such as somal sprouts, spine-like structures on the surface of the soma and stem dendrites, thick stem dendrites, multiple focal swellings of the stem and distal dendrites, reduction in the size of dendritic trees and axonal focal swellings. These changes were gradually improved in the Ml/Ml with CuCl2 treatment after day 20, with the exception of the multiple focal swellings of the stem and distal dendrites. The dendritic focal swelling gradually decreased after day 45. These clinical and neuropathological features of the Ml/Ml are almost same as those of the Ml/y. In our mutant mouse, when the treated Ml/Ml is coupled with the treated Ml/y all offspring from the Ml/Ml are genetically Ml/y or Ml/Ml. Our study indicates that these fetal mice may be useful for studying the pathological and biochemical condition of prenatal MKHD.

Animals↗
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↗
PubMed1989

[Chronic myelomonocytic leukemia (CMMoL) with systemic lymph node swelling and paroxysmal nocturnal hemoglobinuria (PNH)-like complication].

A 37-year-old male was diagnosed as having chronic myelomonocytic leukemia (CMMoL) with chief complaint of systemic lymph node swelling. On admission, his peripheral blood revealed mild anemia and mild thrombocytopenia with giant platelets, and monocytosis (1480/microliters). NAP score was low. Serum lysozyme increased. The bone marrow showed normal cellularity consisting of 4% myeloblasts and 14.4% promyelocytes, and a few myeloid cells were positive for double staining by alpha-naphthyl butyrate and naphthol ASD chloroacetate esterase. Biopsied specimens of the cervical lymph node showed infiltration of monocytoid cells, which were positive for lysozyme staining, into interfollicular tissue. As for chromosome variation, 21 large satellite was observed in all dividing cells from his bone marrow and peripheral blood. Furthermore, hemolytic anemia with hemoglobinuria developed during his course. Sugar water test was positive, but Ham test negative. Coombs test and Donath-Landsteiner reaction were negative. Abnormal hemoglobin, spherocyte and fragmentation were not found. Hemolysis disappeared about two months later. However, blastic crisis appeared and he died. We showed a case of CMMoL with 21 large satellite and paroxysmal nocturnal hemoglobinuria (PNH)-like complication. Satellite have usually been reported as asymptomatic, and thus this chromosome variant and CMMoL may have been coincidentally observed.

Adult↗
PubMed1988

Electron microscopic study on brain of macular mutant mouse after copper therapy.

The hemizygote of the macular mutant mice, which is clinically and neuropathologically considered to be a model of Menkes kinky hair disease (MKHD), were injected intraperitoneally four times with 10, 20, 20 and 30 micrograms of cupric chloride on days 4, 6, 8 and 10 after birth, respectively. Their cerebral and cerebellar cortices were chronologically examined by electron microscopy. In the cerebral cortex, only a few abnormal mitochondria with electron-lucent matrix and short peripherally located cristae were scattered in the neurons on day 14, and these had almost entirely vanished after day 21. In the cerebellar cortex, abnormal mitochondria were frequently found on day 14 in the dendrites of the Purkinje cells, whereas they were only occasionally observed in their cytoplasm. Those in the dendrites had decreased in number on day 30, and only a few of them were seen in the cerebellum after day 45. These results show that the copper therapy reduced ultrastructural abnormalities in the hemizygote of this mutant mouse.

Animals↗