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Biomedical subjects

F Endo

Publications and source records attributed to F Endo.

At least 181 records · Page 10Linked to original sources
PubMed1983

Ornithine carbamoyltransferase (OCT) in the jejunal mucosa, as a reference of the liver OCT.

Ornithine carbamoyltransferase (OCT) was purified from normal human liver by a modification of the method of Kalousec. The protein is homogeneous by electrophoresis in sodium dodecyl sulfate containing gels and in non-dissociating gels. The specific activity is 186 mumol X min-1 X mg-1 protein. The purification factor was approximately 365, and the net recovery 3.2%. Antibodies were prepared in rabbits directed against the purified protein. These antibodies reacted specifically with purified OCT, with a crude extract of human liver and with the partially purified enzyme of the human small intestine. Apparent Km's of OCT in the jejunal mucosa were similar to those of the liver. Physical parameters, including heat stability and pH profile, were also similar to those of liver. These results suggest that OCT in the jejunal mucosa might be of the same genetic origin as that of the liver. In addition, the fact that OCT activities were similar in jejunal samples taken from different areas indicates that jejunal mucosa obtained by per oral biopsy may be useful in detecting OCT deficiency as an alternate to liver tissue.

Chromatography, DEAE-Cellulose↗
PubMed1983

Kinetic analysis of argininosuccinate synthetase in a variant form of citrullinaemia.

Argininosuccinate (ASA) synthetase in the liver from a patient with a variant form of citrullinaemia was analysed. Serum citrulline level was approximately 40 times higher than the control level, and the ASA synthetase activity was approximately 10% that of the control. Other urea cycle enzymes were within normal ranges. The specific activity (enzyme activity/enzyme protein, measured by immunochemical method), pH optimum, Michaelis constants, and thermal denaturation in the presence or absence of ASA were similar to those in enzymes obtained from the normal and the patient's liver cells. No in vitro effect of the patient's liver homogenate on ASA synthetase in normal liver was observed. Serum citrulline levels of the patient's parents and young brother were at the maximal level of control at fasting and definitely elevated 4 h after citrulline loading (100 mg/kg).

Adult↗
PubMed1983

Chemotactic receptor of cord blood granulocytes to the synthesized chemotactic peptide N-formyl-methionyl-leucyl-phenylalanine.

Chemotactic mobility of cord blood granulocytes (CBG) was studied under varying concentrations of synthesized chemotactic peptide, N-formyl-methionyl-leucyl-phenylalanine (f . Met-Leu-Phe). The maximal chemotactic mobility was found at a concentration of 2 X 10(-7)M in CBG and 1 X 10(-7)M in adult blood granulocytes (ABG) (n = 8). The maximal distance of granulocyte mobility of CBG was significantly shorter than that of ABG (P less than 0.01). The number of chemotactic receptors and the affinity constant were assayed by the competitive inhibition method, using f . Met-Leu-[3H]Phe, and the data were subjected to Scatchard analysis. The number of chemotactic receptors of ABG was 2.5-fold of CBG, as shown by 21,800 +/- 7800 per cell in ABG (n = 3) and 9000 in CBG (n = 1). This figure was confirmed by the one point assay method by increasing the sample numbers of cord blood. It was found that bound chemotactic peptide (X 10(-14) moles/10(7) cells) was 7.9 +/- 0.7 in ABG (n = 4) and 3.4 +/- 0.7 in CBG (n = 5). Affinity constants were similar in CBG and ABG.

Chemotaxis, Leukocyte↗
PubMed1983

Four-hydroxyphenylpyruvic acid oxidase deficiency with normal fumarylacetoacetase: a new variant form of hereditary hypertyrosinemia.

Enzymatic studies on the liver of an infant are described-a case of hypertyrosinemia without hepatic dysfunction. His parents were siblings and the mother had hypertyrosinemia. Excessive amounts of 4-hydroxyphenylpyruvic acid (pHPP), 4-hydroxyphenylacetic acid (pHPL), and 4-hydroxyphenylacetic acid (pHPA) were found to be excreted in the patient's urine as well as in the urine of the mother and the inhibitor of porphobilinogen synthetase was not found. Soluble tyrosine aminotransferase (s-TAT), separated from that of the mitochondrial form (m-TAT) by DE 52 column chromatography, was normal in the patient's liver, both quantitatively and qualitatively. The activities of fumarylacetoacetase in the patient's liver and in the peripheral leucocytes from the parents were normal. The activity of pHPP oxidase in the patient's liver was approximately 5% of the control and the enzyme had a high Km value for pHPP (controls: 0.06 +/- 0.01 mM, patient: 0.23 +/- 0.03 mM). From these results, the patient was thought to be different from previously described types of tyrosinemia and perhaps representative of a new variant form. This is the first report concerning 4-hydroxyphenylpyruvic acid oxidase deficiency alone. Mild metal retardation and mild hypertyrosinemia may be offered as typical clinical features of the disease.

4-Hydroxyphenylpyruvate Dioxygenase↗
PubMed1982

Skin histidase activity and urine formiminoglutamic acid (FIGLU) in patients with histidinemia found by screening newborn infants.

Skin histidase activities and urine formiminoglutamic acid (FIGLU) levels were measured in 20 patients with histidinemia, identified by Guthrie's screening method, and their family members as well as control subjects. There was a significant positive correlation between skin histidase activities and the amounts of urine FIGLU. Although the difference of skin histidase activity and the amount of urinary FIGLU was significant between any two of the three groups (i.e. controls, parents and patients; p less than 0.005), these levels ranged widely and a considerable number of the cases overlapped among groups. When a discriminant function was computed to obtain the minimum probability of misclassification between the groups using the above two parameters, a better segregation was observed. However, even though the number of misclassifications decreased, the overlapping cases were still present, especially between the parent and patient groups. It is concluded that either skin histidase activity, urine FIGLU, or both, can be used as genetic markers of the disease to a large but still limited extent.

Amino Acid Metabolism, Inborn Errors↗
PubMed1982

Carnitine deficiency and hyperammonemia associated with valproic acid therapy.

Plasma carnitine and blood ammonia concentrations were measured in 25 severely handicapped patients, ages 3 to 21 years, and 27 age-matched control subjects. Fourteen of the handicapped patients were treated with anticonvulsant drugs including valproic acid; the remaining 11 patients were treated with drugs excluding valproic acid. Plasma carnitine concentrations were lower and blood ammonia values were higher in patients treated with valproic acid than in the untreated patients and control subjects. A significant inverse relationship was found between plasma carnitine concentrations and the dosage of valproic acid, and between plasma carnitine and blood ammonia values. After oral administration of D,L-carnitine (50 mg/kg/day) for four weeks, both carnitine deficiency and hyperammonemia were corrected.

Adolescent↗
PubMed1982

Sural nerve lesions in a case of hypertyrosinemia.

A sural nerve obtained three hours after death from a patient with hypertyrosinemia due to 4-hydroxyphenylpyruvic acid oxidase deficiency was examined. The diameter of the myelinated fibers, as seen on the histogram, was similar to those in an age matched control. However, the number of smaller fibers was greater. Electron-microscopically, the findings of de- and hypomyelination were noted, and occasional dense bodies and multimembranous bodies were seen in some axoplasms. Since his mother was also suffering from hypertyrosinemia, the serum tyrosine level during the fetal and newborn infant periods seemed to be constantly elevated, which may have caused the abnormalities of nerve fibers observed in the present case.

4-Hydroxyphenylpyruvate Dioxygenase↗
PubMed1982

Induction of immunological tolerance to single-stranded and double-stranded DNA.

Single-stranded (ss) and double-stranded (ds) DNA were conjugated with the copolymers of d-glutamic acid and d-lysin (d-GL). Administration of ss-DNA-d-GL conjugates to C3H/H3 and NZB/W F1 mice could render the mice tolerant to both direct and indirect anti-ss-DNA antibody-forming cell responses, irrespective of their immune status. Repeated administration of ss-DNA- or ds-DNA-d-GL conjugates decreased the levels of anti-ss-DNA and anti-ds-DNA antibody titres and reduced the occurrence of ss-DNA and ds-DNA antibody-forming cells even in old female NZB/W F1 mice that had already developed an autoimmune state with lupus nephritis. The unresponsiveness was DNA-specific, and the state of tolerance was stable in vitro at the cellular level after the removal of the tolerogen. This tolerance model would be useful in analysing the regulatory mechanisms in anti-ss-DNA nd anti-ds-DNA antibody production, and application of this kind of therapy in the treatment of systemic lupus erythematosus is suggested.

Aging↗
PubMed1982

Human erythrocyte prolidase and prolidase deficiency.

Biochemical studies on human prolidase (EC 3.4.13.9) and prolidase deficiency are described. The urine sample from a 32-year-old female with prolidase deficiency was examined. Diagnosis was based on clinical features and defects of prolidase in her erythrocytes. She excreted massive amounts of iminopeptides, where three major peptides were identified; aspartyl-proline, glutamyl-proline and glycyl-proline. The prolidase was purified approximately 10,000-fold from the normal human erythrocytes through an eight step procedure. The purified enzyme consisted of two identical subunits of which the molecular weight was calculated to be 55,000. The relative cleavage rates of the enzyme for glycyl-L-proline, L-alanyl-L-proline, L-leucyl-L-proline, L-prolyl-L-proline, and glycyl-hydroxy-L-proline were 100%, 53%, 27%, 31% and 2%, respectively. The relative substrate specificity of the enzyme offers a reasonable explantation for the presence of a higher level of urinary imidodipeptides in a patient with prolidase deficiency. An attempt at erythrocyte transfusion was performed, aimed at enzyme replacement therapy. After the transfusion (erythrocytes from 800 ml of whole blood), the prolidase activity of the peripheral erythrocyte was elevated to approximately 35% of the normal values and gradually decreased (half-life, 41 days). During this period urinary peptide-bound proline was monitored, but no significant change was observed.

Adult↗
PubMed1982

Relationship between complement-fixing (hemolytic) antibodies to single-stranded and double-stranded DNA and the prognosis in systemic lupus erythematosus.

Hemolytic (complement-fixing) antibodies to single-stranded (ss) or double-stranded (ds) DNA, measured by recently developed PHL assay, occurred closely correlated with renal activity in patients with systemic lupus (SLE). Approximately one third of the patients with renal disease had hemolytic antibodies to ss-DNA but never to ds-DNA. Hemolytic antibodies were scarcely detectable in patients with mild course. Serial studies also revealed that the estimation of the hemolytic antibodies to ds- and/or ss-DNA was particularly valuable in predicting the future course of the SLE. The emergence of hemolytic antibodies to DNA may be an ominous sign suggestive of grave prognosis in SLE.

Adolescent↗