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Biomedical subjects

K Hayasaka

Publications and source records attributed to K Hayasaka.

At least 199 records · Page 11Linked to original sources
PubMed1987

Partial ornithine transcarbamylase deficiency in females: diagnosis by an immunohistochemical method.

Females heterozygous for the X-linked urea cycle disorder, ornithine transcarbamylase (OTC) deficiency have a significant risk of developing hyperammonaemia. Diagnosis of this genetic defect in a proband is the essential starting point for family studies. By an immunohistochemical analysis of the liver specimens fixed in 10% formalin, we confirmed heterozygous status for OTC deficiency in two female patients, a 15-year-old girl and a 2-year-old girl, who died of hyperammonaemia. Since most affected males lack cross reactive materials (CRM), an immunochemical analysis should be useful for the diagnosis of most heterozygous females.

Adolescent↗
PubMed1987

Non-ketotic hyperglycinaemia: clinical and biochemical aspects.

Non-ketotic hyperglycinaemia is an autosomal recessive disorder of glycine metabolism characterized by elevated concentrations of glycine in plasma, urine and cerebrospinal fluid. The fundamental defect was found to lie in the glycine cleavage system. It is of significance that the major pathway for the catabolism of glycine was elucidated through the studies of hyperglycinaemia. The present knowledge about non-ketotic hyperglycinaemia is described in clinical and biochemical aspects.

Amino Acid Metabolism, Inborn Errors↗
PubMed1987

Nystagmus and subnormal electroretinographic response in nonketotic hyperglycinemia.

We examined ophthalmologically two siblings with nonketotic hyperglycinemia who had negligible activities of glycine cleavage system in the liver. Both had jerky nystagmus. The elder brother had a normal electroretinographic response, while the younger brother's response was subnormal. There may be a close association of subnormal electroretinographic response and hyperglycinemia, because glycine can act as an inhibitory neurotransmitter in the retina.

Amino Acid Metabolism, Inborn Errors↗
PubMed1987

Nonketotic hyperglycinemia: analyses of glycine cleavage system in typical and atypical cases.

The molecular nature of the glycine cleavage system was investigated in eight patients with typical (neonatal) and two patients with atypical (late onset) nonketotic hyperglycinemia (NKH). The overall activity of the glycine cleavage system was found to be decreased in all of the liver and brain tissue studied, but it was undetectable or extremely low in typical NKH, whereas there was some residual activity in atypical NKH. Six patients with typical NKH had a specific defect in the P protein, and one a defect in the T protein; the activity of the T protein was defective in one patient with atypical NKH.

Amino Acid Oxidoreductases↗
PubMed1987

Partial and complete adenine phosphoribosyltransferase deficiency associated with 2,8-dihydroxyadenine urolithiasis: kinetic and immunochemical properties of APRT.

We have studied adenine phosphoribosyltransferase (APRT) in the hemolysates from the families of 2,8-dihydroxyadenine urolithiasis associated with partial deficiency of APRT (the Japanese type) and complete deficiency of APRT (the null type). The APRT in the control subjects was found to be heat-stable at the physiological concentration of phosphoribosylpyrophosphate (PRPP), which was close to the value of its Km for PRPP. The APRT in the Japanese type showed 10 times higher Km values for PRPP and needed a comparably increased level of PRPP for stability in vitro. No change in red cell PRPP was found in the Japanese type of APRT deficiency. The content of APRT enzyme protein was decreased in the hemolysates of the Japanese type, probably due to its lability at the level of PRPP present in the cells. The heterozygote of the null type also had labile enzyme molecules at the physiological PRPP concentration.

Adenine↗
PubMed1986

Difficulties in assessing the effect of strychnine on the outcome of non-ketotic hyperglycinaemia. Observations on sisters with a mild T-protein defect.

Sisters with a mild variant of non-ketotic hyperglycinaemia resulting from a defect in the T-protein of the glycine cleavage system had different clinical outcomes. The older sister was ascertained at 6 months of age because of mental retardation. She received only brief treatment with sodium benzoate from 11-15 months and at 15 years of age is profoundly retarded and has epilepsy. The younger sister was diagnosed 36 h after birth, was treated with strychnine, sodium benzoate and arginine from the neonatal period and at 27 months of age is only moderately retarded and free of seizures. The possible role of strychnine in the improved outcome is discussed.

Adolescent↗
PubMed1986

Non-ketotic hyperglycinaemia due to a deficiency of T-protein in the glycine cleavage system in liver and brain.

Non-ketotic hyperglycinaemia was diagnosed in a girl at 3 weeks of age because of the typical clinical presentation, the elevated glycine concentration in urine, plasma and especially in cerebrospinal fluid and the normal profile of organic acids in urine. An EEG showed the typical burst suppression pattern. Therapeutic approaches with either pyridoxine (50 mg d-1) alone or in combination with N5-formyltetrahydrofolate (3 X 3 mg d-1) or with strychnine (0.3 mg per kg body weight) did not result in improvement. In postmortem liver and brain of the patient the overall activity of the glycine cleavage system was deficient; examination of the activity of the individual components of the glycine cleavage system in the tissues revealed that the activity of the T-protein was undetectable, whereas that of the other components and of lipoamide dehydrogenase was normal.

Aminomethyltransferase↗
PubMed1986

Effects of valproate on biogenesis and function of liver mitochondria.

The mitochondrial protein content of liver increased, and mitochondria enlarged after prolonged administration of valproic acid (VPA: N-dipropylacetic acid) to rats. The mitochondria showed low specific activities of membrane-bound enzymes, decreased content of cytochrome aa3, and decreased respiration in states 3 and 4. In vitro studies of amino acid incorporation suggested a decrease in protein synthesis in liver mitochondria from VPA-treated rats. Prolonged administration of VPA seems to impair mitochondrial structure and function.

Amino Acids↗
PubMed1986

[Internal malignancies and skin lesions].

In the early stage of internal malignancies, it is important to detect the relation between the malignancy and accompanying skin lesions. Skin lesions are commonly classified according to their origin as follows; skin lesions induced by internal malignancies, skin lesions as a part of a syndrome, nonspecific lesions and complications of internal malignancies, but with an unknown relationship so-called Bowen's disease, and Paget's disease. These skin lesions consist of various kinds and are multiple. Commonly, the disease which is detected seems to be an immunological reaction to internal malignancy; malignant acathosis nigricans, and dermatomyositis are examples in point. A description of internal malignancies and skin lesions is presented, including those which are most commonly encountered together with a description of such cases experienced at the National Cancer Center Hospital.

Acanthosis Nigricans↗