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Biomedical subjects

H Oyanagi

Publications and source records attributed to H Oyanagi.

At least 19 recordsLinked to original sources
PubMed1992

[Therapeutic inventions of perioperative metabolic care in diabetic patients].

Perioperative metabolism was evaluated in diabetic patients and animal models. Experimental model of diabetes mellitus (DM) model was obtained by streptozotocine injection. Each 14C-labeled substrates and combination of carbohydrates mixture was administered intravenously in a dose of 1 g/kg before and after laparotomy and cumulative curves of expired 14CO2 was calculated. Biochemical analysis in the liver, blood and urine were performed following infusion of two different solutions, GFX (glucose, fructose, xylitol) solution, 4:2:1 ratio by weight vs. glucose solution, with 12% amino acids solution. In a clinical study, incidence of DM in digestive surgery was examined in 3481 cases. Retrospective evaluation of GFX solution was performed in cases after total gastrectomy. Incidence of DM was 14% and it has been increased recently, Glucose metabolism in DM rats was disturbed after surgery. Amino acids (alanine and valine) and lipid metabolism was slightly suppressed after surgery in DM rats. The best combination of carbohydrate mixture was determined as GFX solution in animal and clinical experiments. GFX solution improved not only glucose metabolism but also lipid and amino acid metabolism in DM rats. Decreased insulin requirement and increased total caloric intake were observed in DM and borderline DM cases treated by GFX solution.

Amino Acids↗
PubMed1992

[The direct hemodynamic effects of dopamine on hepatic blood flow in the dog--use of direct hemoperfusion (DHP) under hepatic venous isolation (HVI)].

We studied the direct effects of dopamine on hepatic blood flow using DHP under HVI. Dopamine was given to mongrel dogs through either the right antecubital vein (group I: n = 3), the hepatic artery-HA (group II: n = 7) or the portal vein-PV (group III: n = 6). In groups II and III, DHP under HVI was performed to eliminate the cardiovascular influence caused by the extraregional distribution of dopamine. In group I, HA/AO decreased from 2 +/- 10 to 29 +/- 9% with infusions of dopamine from 1 to 10 micrograms/kg/min. The peak increase in PV/AO was only 14 +/- 11%. In groups II and III, plasma concentrations of dopamine in the hepatic venous blood were reduced to as low as 2.7 +/- 1.6% after DHP, and AO flow remained unaltered. Dopamine infusions in doses from 0.25 to 10 micrograms/kg/min through HA and PV resulted in dose dependent reductions of HA/AO from 4 +/- 14 and 10 +/- 9% to 42 +/- 12 and 51 +/- 11%, respectively. In contrast, PV/AO remained unchanged. Although alpha 1 antagonist reversed these hemodynamic effects, no remarkable change was observed with DA1-antagonist. In conclusion, dopamine seems to act at the site of either sinusoidal or post-sinusoidal level probably as an alpha-agonist. In addition to dopamine's effect on PV flow, our study indicates that increased attention should be given to its activity in reducing HA flow.

Animals↗
PubMed1991

Structural and electronic characterization of heme moiety in oxygenated hemoproteins by using XANES spectroscopy.

Iron K-edge X-ray absorption near edge structure (XANES) spectra were measured for oxy-forms of cytochrome P-450cam (P-450cam), horseradish peroxidase (HRP) and myoglobin (Mb) by using Synchrotoron Radiation of Photon Factory (Tsukuba). A pronounced 1s-4p transition and some fine structures were well-resolved in the spectra obtained. Comparing the spectra, the features at the fine structures termed P, C and D, were similar among the three hemoproteins, suggesting a similar site-symmetry around the heme iron and the same Fe-O-O bond angle (about 115 degrees). On the other hand, absorption features at the edge region (7115-7135 eV) were slightly but significantly different from one another; the absorption intensity at 7115-7125 eV region increased in the order of Mb, HRP and P-450cam, while that at 7125-7135 eV decreased in the same order. A similar absorption feature was also obtained with their deoxy (ferrous high spin) forms. We assumed that the absorption at the lower energy region (7115-7125 eV) reflects the pi-character in the Fe-ligand bond, whereas that at the higher energy region (7125-7135 eV) does the sigma-character, on the basis of the previous and comprehensive studies of the XANES spectroscopy of the adsorbed molecules on the metal surface (McGovern et al. (1989) Handbook on Synchrotoron Radiation, Vol. 2, pp. 467-539). According to our assumption, our XANES results indicated that the pi-character of the Fe-ligand bond increases in the order of Mb, HRP and P-450cam, and that the pi-electron of the thiolate S- in P-450cam is donated to the Fe-O-O moiety, most probably to the antibonding pi* orbital of O2. Such an interpretation is consistent with the experimental findings or data accumulated so far by other methods, such as the resonance Raman spectroscopy.

Animals↗
PubMed1991

[Clinical studies on 3 pairs of monozygotic twin sisters affected by Graves' disease].

Clinical studies were undertaken of three pairs of monozygotic twin sisters affected by Graves' disease. The evidence that the twins were monozygotic was established by similarity in physical appearance, identical blood-group antigens and identical HLA types. All pairs were female, and the evidence of Graves' disease in both members of the pair was observed in 2 out of 3 pairs. In the remaining pair the disease started in the elder sister, but the younger sister still remained in euthyroidism in spite of the presence of diffuse goiter. The disease occurred in the second decade in all the patients, and the interval between the occurrence of the disease in twin sisters was 1 to 4 years. No common specific type of HLA was found among all three pairs, but DR4 was common in two pairs of twin sisters showing positive MCHA test. Serum TRAb was positive in 2 pairs of twin sisters but negative in the remaining one. However, it became positive in the elder sister of the latter pair during the antithyroid treatment. The effect of antithyroid drug treatment was found to be similar in each of the twin sisters, and the serum TRAb moved almost in parallel with serum FT4 level. These results indicate that a genetic factor may be of great importance in the aetiology of Graves' disease, and there was a strong preponderance for it to occur in women and the second decade was the peak age for its occurrence. The common specific type of HLA for all Graves' patients was not found in this study. A strong relationship was observed between Grave's disease and TRAb.

Adult↗
PubMed1991

Structural and functional modifications of the manganese cluster in Ca(2+)-depleted S1 and S2 states: electron paramagnetic resonance and X-ray absorption spectroscopy studies.

The effect of extraction of weakly bound Ca2+ by low-pH treatment on the O2-evolving apparatus was studied by use of low-temperature electron paramagnetic resonance (EPR) and X-ray absorption spectroscopy. In low-pH-treated PSII membranes, an S2 EPR multiline signal with modified line shape was induced by illumination at 0 degrees C, but its signal amplitude decreased upon lowering the excitation temperature with concomitant oxidation of cytochrome (cyt) b-559 in place of Mn. The half-inhibition temperature for formation of the modified multiline signal was found at -33 degrees C, which was much higher than that for formation of the normal S2 state in untreated control membranes. Signal IIf was normally induced down to -30 degrees C, but its dependence on excitation temperature was different from that for modified S2. This was interpreted as indicating that the low-temperature blockage of modified S2 formation is due to the incapability of electron abstraction from the Mn cluster. The Mn K-edge of X-ray absorption near-edge structure (XANES) spectrum shifted to lower energy by 0.8 eV after low-pH treatment, but the shift was reversed by addition of Ca2+. Upon illumination at 0 degrees C of treated membranes, the K-edge energy was up-shifted by 0.8 eV, but was not upon illumination at 210 K. These results were interpreted as indicating that extraction of weakly bound Ca2+ by low-pH treatment gives rise to structural and functional modulations of the Mn cluster.

Calcium↗
PubMed1991

A case of intestinal T-cell lymphoma with repeated episodes of perforation.

A case of intestinal cytotoxic/suppressor T-cell lymphoma with repeated episodes of perforation was seen in a 77-year-old Japanese male who was admitted complaining of severe abdominal pain accompanied by high grade fever. Surgery revealed diffuse peritonitis due to perforation in the sigmoid colon. After a loop sigmoid colostomy the patient recovered to some degree. Seven days later, however, another perforation occurred. Several aneurysmal swellings accompanied by perforation in the small intestine, forming a mass of 5 x 5 cm, were seen. Although the patient tolerated this operation, generalized emaciation proceeded and the patient died 10 days late. Histological examination at the second operation showed diffuse medium-sized lymphoma of the Lymphoma Study Group (LSG) classification infiltrating the entire depth of the intestinal wall. Destruction of muscle cells was prominent. An immunohistochemical study using fresh frozen material was positive for CD3, and CD8. This marked destruction of the muscle layer by lymphoma cells may be associated with repeated episodes of perforation.

Aged↗
PubMed1990

Mn K-edge XANES spectroscopy of a photosynthetic O2-evolving complex. High-quality pre-edge features and distinct fine structures in the S1- and S2-states.

High-resolution XANES (X-ray Absorption Near Edge Structure) spectroscopy for Mn in the S1 and S2 states of the spinach photosynthetic O2-evolving complex revealed distinct features in K-edge spectra, when a high signal-to-noise (S/N) ratio of ca. 80 with a low and constant background-to-signal (B/S) ratio of 0.15 to 0.18 was attained. Six features resolved in each S-state spectrum involve a pre-edge feature due to 1s----3d transitions, a main-edge feature possibly due to 1s----4s transitions and four fine structures superimposed on the principal absorption bands due to 1s----4p* transitions. The high-quality pre-edge features were analyzed according to a parametric ligand-field theory in comparison with those of some typical authentic Mn complexes. It was deduced that i) all of the four Mn ions in the S1-state are octahedrally coordinated and two of them constitute a di-mu-oxo bridged Mn(III, III) dimeric subunit; ii) the bridged Mn(III) ions are further bridged by a deprotonated water dimer, (HOHOH)-, and coordinated by imidazole-N and carboxylate-O- on the opposite side of the Mn atom from the di-mu-oxo bridge; iii) the other two Mn ions exist in the form of Mn(III) monomeric subunits; and iv) upon the S1----S2 transition, only the bridged Mn(III,III) is oxidized to Mn(III,IV). The distinct change in the principal absorption band shape upon the S1----S2 transition is briefly discussed to obtain the XANES evidence for a tetrameric Mn-cluster.

Cell Membrane↗
PubMed1990

Paracoccus aminophilus sp. nov. and Paracoccus aminovorans sp. nov., which utilize N,N-dimethylformamide.

Two methylamine- and N,N-dimethylformamide-utilizing Paracoccus spp. are described. These bacteria are gram-negative, nonsporeforming, nonmotile, coccoid or short rod-shaped organisms. Their DNA base composition is 62 to 68 mol% G + C. Their cellular fatty acids include large amounts of C18:1 acid. Their major hydroxy acids are 3-OH C10:0 and 3-OH C14:0 acids. The major ubiquinone is Q-10. These bacteria are distinguished from Paracoccus denitrificans and Paracoccus alcaliphilus by physiological characteristics and by DNA-DNA-homology. Paracoccus aminophilus sp. nov. and Paracoccus aminovorans sp. nov. are proposed. The type strain of P. aminophilus is DM-15 (= JCM 7686), and the type strain of P. aminovorans is DM-82 (= JCM 7685). Paracoccus halodenitrificans is distinguished from other Paracoccus species on the basis of cellular fatty acid composition, hydroxy fatty acid composition, and DNA-DNA homology. It may not be a valid member of the genus Paracoccus.

Base Composition↗
PubMed1989

Detection of anti-rotavirus IgG, IgM, and IgA antibodies in healthy subjects, rotavirus infections, and immunodeficiencies by immunoblotting.

Immune responses to individual simian rotavirus (SA 11) structural polypeptides were studied with emphasis on specific IgG, IgM, and IgA in paired sera from four children with rotavirus infections. Responses to simian rotavirus (SA 11) were also studied in 103 healthy children, 10 patients with primary immunodeficiency who received intravenous immunoglobulin, and 11 human immunodeficiency virus antibody-positive patients. All samples were immunoblotted for two major polypeptides--VP2 and VP6--of IgG. Immunoblotted IgA and IgM were elevated 2-4 weeks after the onset of the disease (stage II) in patients with rotavirus infection. Immunoblotted IgG remained almost the same at the onset of the disease and stage II. The scores for primary and secondary immunodeficiency patients were lower than for healthy children. The score obtained by totaling all polypeptides found in each individual was compared with the optical density (OD) value obtained by enzyme immunoassay.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Evidence against the importance in the disease process of antibodies to bovine thyroid-stimulating hormone found in some patients with Graves' disease.

The antibody to TSH (TSH-Ab) found in some patients with Graves' disease may be either an antiidiotype (anti-id-Ab) to the TSH receptor antibody (TRAb) or the antigen (idiotype) for which the anti-id-Ab is in fact TRAb. Four groups have found antibodies to bovine TSH (bTSH-Ab) in Graves' disease patients in a TSH binding-inhibiting immunoglobulin (TBII) RRA that uses [125I]bTSH. In this assay serum samples containing bTSH-Ab give highly negative TBII values. The purpose of this study was to look for any clinical significance of potential idiotypic-antiidiotypic network regulation related to bTSH-Ab. Twenty-one (0.49%) of 4285 Graves' disease patients had TBII values less than the mean -4 SD of normal subjects. In all 21, bTSH-Ab was found by incubation of [125I]bTSH with the patient's serum, and significant inhibition of binding of bTSH-Ab to bTSH by human TSH was found in only 3 of these serum samples. We investigated next whether the binding site of the anti-TSH-Ab mimicked the TSH receptor-binding site. Binding of [125I]bTSH to bTSH-Ab-positive serum was not inhibited by bTSH-Ab-negative, thyroid-stimulating immunoglobulin-positive [(+)], and/or TBII(+) immunoglobulin G. In one patient with human TSH-Ab, TSH-Ab appeared and disappeared, and when TSH-Ab was negative, TBII was positive. Inhibition of [125I]bTSH binding to TSH-Ab by the same patient's serum when that patient was serum thyroid-stimulating immunoglobulin(+), TBII(+), and TSH-Ab-negative was sought but not found. Changes in serum TSH-Ab activity and disease activity were not correlated in this patient. In six untreated patients with Graves' hyperthyroidism with bTSH-Ab, the serum T3 and T4 concentrations and the time required to become euthyroid during antithyroid drug treatment were not significantly different from those in 52 such patients without bTSH-Ab. These data suggest that bTSH-Ab is not an anti-id-Ab to TRAb and that TSH-Ab does not directly modulate the activity of Graves' disease.

Animals↗
PubMed1987

High maintenance rate of sinus rhythm after cardioversion in post-thyrotoxic chronic atrial fibrillation.

We performed rhythm conversion on 33 euthyroid patients with post-thyrotoxic atrial fibrillation who do not revert spontaneously to sinus rhythm from atrial fibrillation. The duration of atrial fibrillation ranged from 9 to 59 months (mean 25 +/- 14). The protocol of rhythm conversion was to first attempt pharmacological conversion with disopyramide and then to perform electrical cardioversion on the non-converters. Of 33 patients, 25 were converted to sinus rhythm (6 by disopyramide and 19 by electrical cardioversion), resulting in 8 non-converters. However, it was later discovered that cardioversion had been applied to 4 of the 8 non-converters when these patients had had a recurrence of thyrotoxicosis. These 4 patients were subjected to a second electrical cardioversion after attaining the euthyroid state. Sinus rhythm was restored in all 4 patients, giving a cardioversion rate of 88%. The sinus rhythm was maintained in 25 of the total 29 converters (86%) at the time of follow-up (10-68 months, mean 35 +/- 19 months). Our studies suggest that cardioversion should be encouraged for thyrotoxic atrial fibrillation, even if the duration of atrial fibrillation is long-standing, since there is excellent maintenance of sinus rhythm and even delayed application of cardioversion may improve its success rate.

Adult↗
PubMed1986

Antithyroid drug therapy for Graves' disease during pregnancy. Optimal regimen for fetal thyroid status.

We compared fetal and maternal serum indexes of thyroid status at delivery in 70 patients with Graves' disease who required therapy with thionamides (such as propylthiouracil) during pregnancy. Forty-three mothers required thionamides until delivery (Group 1), whereas the drugs were discontinued during pregnancy after remission in 27 mothers (Group 2). Maternal free thyroxine levels were closely correlated with cord levels in both groups, being essentially identical in Group 2 but slightly lower in fetuses than in mothers in Group 1. Normal maternal free thyroxine levels did not preclude fetal hypothyroidism. The mothers and fetuses in Group 1 had a significantly higher incidence of antibodies that inhibit thyrotropin binding than did those of Group 2. However, a significant correlation between maternal levels of these antibodies and cord levels of free thyroxine or triiodothyronine was found only in Group 2, in which some maternal and cord thyroxine levels were in the thyrotoxic range at delivery, presumably because therapy was discontinued. These findings indicate that high free thyroxine levels and the presence of antibodies that inhibit binding of thyrotropin are useful indexes of the fetal need for antithyroid treatment, and that the thionamide dosage that maintains maternal free thyroxine levels in a mildly thyrotoxic range seems appropriate for maintaining euthyroid status in the fetus.

Antibodies↗
PubMed1986

Hypertrophic cardiomyopathy and thyroid diseases.

The incidence ratio of thyrotoxicosis among 14 patients with thyroid diseases associated with hypertrophic cardiomyopathy was compared with that in 7686 patients with thyroid diseases, to find the possible correlation between thyrotoxicosis and hypertrophic cardiomyopathy. Thyrotoxicosis did not predominate over other thyroid diseases in the 14 patients with hypertrophic cardiomyopathy. Thus, the occurrence of hypertrophic cardiomyopathy does not appear to be associated with thyrotoxicosis.

Adult↗