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Biomedical subjects

Y Nonaka

Publications and source records attributed to Y Nonaka.

At least 109 records · Page 6Linked to original sources
PubMed1982

Arginyl residues of adrenodoxin reductase as the anion recognition site for 2'-phosphate group of NADP+1.

Adrenodoxin reductase from bovine adrenocortex was inactivated by arginine specific reagents, p-hydroxyphenylglyoxal, phenylglyoxal, 2,3-butanedione, and 1,2-cyclohexanedione. Inactivation of the enzyme caused by p-hydroxyphenylglyoxal obeyed pseudo-first-order kinetics and resulted in complete elimination of NADPH-ferricyanide reductase activity. The rate of inactivation increased with pH from 6.5 to 9.5. Ten out of 30-33 arginyl residues of the enzyme were modified, but residues essential to its enzymatic activity were less than 5. NADP+ strongly protected against inactivation by p-hydroxyphenylglyoxal, whereas NAD+ could afford only partial, weak protection. Furthermore, 2'-AMP and 2',5'-ADP afforded considerable protection but 5'-AMP did not. These data suggest that adrenodoxin reductase has essential arginyl residues which are crucial to the enzymatic activity as the recognition site for the negatively charged 2'-phosphate group of NADP+.

Animals↗
PubMed1981

Dilatation of the aortic valve portion in aortitis syndrome. Angiographic evaluation of 70 patients.

The dilatation of the aortic valve portion was evaluated by angiography in 70 patients with aortitis syndrome (Takayasu's arteritis). The diameter at aortic valve commissure was 20 +/- 2.8 min/M2 (NS, vs control) in 46 patients without aortic insufficiency (AI), 23 +/- 2.0 (p less than 0.02, vs without AI) in 11 patients with AI (I or II in grade), 27 +/- 2.0 (p less than 0.01, vs I or II in grade) in 13 patients with AI (III or IV in grade). The diameter was 20 +/- 2.0 in 13 normal control cases and 20 +/- 4.0 in 6 patients with rheumatic AI. The diameters at the levels of aortic valve annulus, sinus of Valsalva and ascending aorta increased also significantly in the patients with AI secondary to aortitis syndrome. The diameter at aortic valve commissure in 24 patients with AI was correlated (r = -0.48, p less than 0.05) to the diastolic blood pressure. Any diameter at the aortic valve portion was not different significantly by the complication of systolic hypertension (greater than or equal to 180 mmHg) in both groups of cases with and without AI. These results indicated that the dilatation of the aortic valve portion was observed in the patient with AI secondary to aortitis syndrome and might be the primary and common cause of AI in all grades, and that the dilatation might not be accelerated by the associated hypertension.

Adult↗
PubMed1981

Immune complexes in Takayasu's arteritis.

We examined sera and Fc receptor-bearing lymphocytes from peripheral blood of patients with Takayasu's arteritis for the purpose of investigating the presence of immune complexes (IC). IC in sera were assayed by solid-phase conglutinin-binding test. Seven of 29 patients exceeded the normal range of circulating IC. IC combined with Fc receptors were estimated by enumerating EA-RFC. EA-RFC of lymphocytes from patients with Takayasu's arteritis were 13.0% and those of normal controls were 29.1%. Low EA-RFC in the patient group increased significantly when lymphocytes were incubated with EA after rising lymphocytes with medium at 37 degrees C. On the contrary, EA-RFC from healthy subjects did not increase after rinsing cells. These findings indicate that IC combined with Fc receptors and hindered EA rosette formation and that rinsing cells with medium at 37 degrees C removed IC from Fc receptors. Comparable results were obtained by a membrane immunofluorescence method using FITC-conjugated anti-human immunoglobulin. In order to confirm that EA rosette formation was really blocked by IC, lymphocytes from a healthy donor were incubated with heat-aggregated human IgG. Incubating cells with IgG aggregates caused reduction of EA-RFC and these lymphocytes restored their ability to form rosettes with EA by rinsing cells with medium at 37 degrees C. In conclusion, we could confirm the presence of IC both in sera and on lymphocyte Fc receptors in some cases of Takayasu's arteritis.

Adult↗
PubMed1980

Immunologic derangement in myotonic dystrophy--abnormal contact sensitization to dinitrochlorobenzene.

A broad spectrum of immunologic parameters was investigated in 13 cases of myotonic muscular dystrophy (MyD), including those for cellular immunity which has attracted little attention in the past. One was a 46-year-old woman having both MyD and a thymoma. This association between MyD and thymoma is probably coincidental without biologic significance. There was no evidence of malignancy in the remaining 12 patients. The delayed cutaneous hypersensitivity reaction to dinitrochlorobenzene was anergic in 3 patients and showed impaired positive reactivity in 3 patients, as compared with no failure of response in normal adults or children with Duchenne muscular dystrophy. A high proportion of patients with MyD displayed positive tuberculin reactions, as did controls. Our case of MyD with a thymoma showed marked lymphocytopenia in peripheral blood, but the number of lymphocytes in peripheral blood in the remaining 12 patients was normal. Uptake of tritiated thymidine by lymphocytes in the presence of phytohemagglutinin was normal. Serum gammaglobulin was reduced in 4 patients with MyD. The mean value of serum immunoglobulin level was decreased only in the class of IgG. A wider derangement of immunologic function may occur in MyD than was previously recognized.

Adult↗
PubMed1977

Analysis of the reactivity of microsomal cytochrome P-450 toward drugs and exogenous ligands.

Three forms of cytochrome P-450 in rat liver microsomes (Comai, K. and Gaylor, J.L. (1973) J. Biol. Chem. 284, 4947-4955) were characterized as two types of P-450 in the membrane-bound state. One was reactive not only toward cyanide but also aniline, aminopyrine, and hexobarbital, and the other was less reactive toward cyanide and rather unreactive toward the drugs. Cyanide titrations of microsomes in the presence and absence of the drugs were performed spectrophotometrically for analysis of the interactions. The affinity of cyanide for the less reactive P-450 was about twenty times less than that for the reactive P-450. About 40% of P-450 in the microsomal membrane was reactive and the rest was the less reactive form. The reactive P-450 involved two forms having different affinities for cyanide. The ratio of their amounts was 1:2. Triton WR-1339 interfered with cyanide binding to the reactive P-450 mainly. The relative amount of each form of P-450 as well as the dissociation constant of cyanide could be estimated by the present method, and the modes of interaction of the membrane-bound P-450 with the drugs and exogenous ligands were deduced.

Aminopyrine↗
PubMed1976

An autopsied case of Eisenmenger syndrome complicated by recurrent thromboembolic phenomena in postpartal period.

Dyspnea, back pain, edema, and cyanosis developed suddenly in a 23-year-old woman during the last trimester of her first pregnancy. Although she had been noticed to have the enlarged heart and exertional shortness of breath to a slight degree, she had been apparently in good condition without any significant heart murmurs. Clinically, recurrent episodes of disseminated intravascular coagulation, including pulmonary thrombosis, were thought to be superimposed to Eisenmenger syndrome associated with toxemia of pregnancy. Anticoagulant and fibrinolytic treatments were tried, but their effectiveness was limited by hemorrhagic diathesis. She died of respiratory and circulatory failure after delivery of a moribund baby. Autopsy revealed Eisenmenger complex (a defect in the membranous portion of the interventricular septum and pulmonary vascular disease) and many fresh hemmorrhages in both lungs with a lot of new and organized thrombi. Fresh thrombi were also seen in the heart, the pancreas and the kidneys. The high peripartal mortality in Eisenmenger syndrome could be attributed to pulmonary thrombosis, which may be related to DIC, as well as to peripartal changes in circulatory function.

Adult↗
PubMed1975

Immunological aspects of aortitis syndrome.

1. Anti-aortic antibodies were frequently detected from the sera of patients with aortitis syndrome. 2. Aortic antigens were demonstrated to exist mainly in the media. The antigenicity was inactivated by collagenase, trypsin and pepsin, but not by DNase-I. Analyses of aortic antigens were also made by ultracentrifugation and column chromatography. 3. Experimental arteritis could be produced in animals by isologous active immunization and heterologous passive immunization. 4. From these results, participation of antigen-antibody reaction in the development of the disease has been speculated. Possible role of streptococcal infection as one of the trigger mechanisms in antibody production has been suggested in combination with evidence indicating hypersensitivity of the patients to infections.

Antibodies, Bacterial↗