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Biomedical subjects

A Yoshida

Publications and source records attributed to A Yoshida.

At least 1,045 records · Page 58Linked to original sources
PubMed1984

Serologic and biochemical studies of a previously unclassified blood type B variant.

The designation B4 is proposed for a weak variant of type B blood found in a Salvadorian woman and her two daughters. The red cells were weakly agglutinated by anti-B and anti-A,B; the serum contained anti-B; and the saliva contained H but not B substance. Biochemical studies of the serum showed that the enzyme specified by the variant B gene had low activity and low affinity for both sugar donor and acceptor.

ABO Blood-Group System↗
PubMed1984

Effect of transition metal ions on lipid peroxidation of rabbit renal cortical mitochondria.

Effect of transition metal ions on lipid peroxidation in rabbit renal cortical mitochondria was studied. The lipid peroxidation of mitochondria was promoted by the metal ions tested in the following order of intensity; Fe2+, Hg2+ and Cu2+. Sodium selenite inhibited Fe2+ or Hg2+-induced lipid peroxidation, but it had no influence on the lipid peroxidation stimulated by Cu2+. This result suggests that the mechanism of the stimulatory effect on lipid peroxidation of Cu2+ may be different from that of Fe2+ or Hg2+ in mitochondria.

Animals↗
PubMed1984

[Nuclear DNA content of thyroid adenocarcinoma].

In order to estimate biological behavior of thyroid adenocarcinoma, the nuclear DNA contents of various thyroid tumors were determined by flow cytometry and microfluorometry. Flow cytometry was performed on 21 patients with benign tumor and 20 with adenocarcinoma. Majority of their modal values in the DNA histograms were diploid or near diploid. There was no obvious difference in ploidy level between benign tumors and adenocarcinomas. However, the mean ratio of cells at a proliferative phase was significantly higher in adenocarcinomas than in benign tumors. Microfluorometry was performed on the surgical specimens taken from 6 patients with anaplastic carcinoma and 25 patients with adenocarcinoma. As to the adenocarcinoma, besides primary lesions, foci of tracheal invasion, lymph nodes with metastatic and recurrent tumors were studied. Most of the DNA histograms of the foci of tracheal invasion showed a wide distribution which was suggestive of dedifferentiation toward anaplastic carcinoma, but other lesions of adenocarcinomas showed no obvious difference from the primary lesions. In patients with recurrent adenocarcinoma, the shorter the interval between the operation and recurrence, the higher the incidence of cells with high ploidy range. From these findings, it was concluded that the nuclear DNA content was estimated as an objective index for the degree of malignancy of thyroid adenocarcinoma.

Adenocarcinoma↗
PubMed1984

Pupillary light reflex in amblyopia.

The pupillary light reflex of 15 strabismic and anisometropic amblyopes, and eight subjects who had recovered from functional amblyopia was studied by using an infrared electropupillogram. Ten of the fifteen amblyopes had significantly longer latencies of contraction when the amblyopic eyes were stimulated than when the normal eyes were stimulated. However, there was no relationship between the delay in pupillary light reflexes and reduced visual acuity of amblyopic eyes. The amplitudes and maximum velocities of the contraction were not altered significantly in amblyopic and normal eyes. All of the subjects who had recovered showed no significant difference of the latencies of the pupillary responses to stimulation between normal and amblyopic eyes. These findings indicate that a retinal mechanism in amblyopic eyes may be responsible for the abnormally long pupillary light reflex latency.

Adolescent↗
PubMed1984

Vitreous fluorophotometric evaluation of diabetics.

Vitreous fluorophotometry measurements taken from diabetic patients with different degrees of retinopathy and from normal volunteers were used to evaluate the integrity of the blood-ocular barrier. The contributions of lens and retinal fluorescence to the measured vitreous fluorescence were investigated. Lens autofluorescence was significantly higher for diabetics than for age-matched normals, and in age-matched diabetics the lens autofluorescence increased significantly with the progression of diabetic retinopathy. Natural ocular fluorescence was corrected for by subtracting baseline values from all vitreous measurements. Analysis of the baseline-corrected vitreous fluorescence values showed that both degree of retinopathy and age significantly affected the measured fluorescence. In age-matched groups, vitreous fluorescence values were greater in diabetics than in normals, and these values increased with the progression of retinopathy. Our results suggest that clinical vitreous fluorophotometry may be useful in evaluating the activity and predicting the progression of diabetic retinopathy.

Adult↗
PubMed1983

[Side effects of antithyroid drugs].

In order to investigate the incidence of side effects of antithyroid drugs and to study if there were any factors related to the onset of the side effects, clinical and laboratory findings were examined in 71 untreated Graves' patients. The overall incidence was 28.2% among 71 cases who were initially administered methimazole or propylthiouracil. The incidences were 23.2% (13 of 56 cases) for methimazole and 46.7% (7 of 15 cases) for propylthiouracil, respectively, which were significantly higher than those previously reported. Seventeen of 20 cases with side effects under the drug of first choice were administered the another antithyroid drug. Four of 17 (23.5%) cases successively had side effects. The side effects were observed within 1.5 months of administration of less than 150 tablets in total in most of the cases. The serum concentration of Ig-E and peripheral eosinophils(/mm3) at the onset of the side effects were significantly higher than those before treatment. These results suggest that allergic mechanism rather than accumulating may concern the onset of side effects. Since in cases without the side effects the peripheral eosinophils at 3 to 4 weeks after administration were significantly higher than those before treatment and 19 of 51 (38.0%) cases without side effects had a high concentration of Ig-E of more than 500 u/ml, it is suggested that allergic mechanism may be triggered in most of Graves' patients who were administered methimazole or propylthiouracil. Thus, immunological disturbances in Graves' disease seems to be the cause of the side effects of antithyroid drugs, although there was no correlation between antithyroid autoantibodies and development of the side effects.

Adolescent↗
PubMed1983

Isolation and characterization of aldehyde dehydrogenase isozymes from usual and atypical human livers.

Usual human livers contain two major aldehyde dehydrogenase isozymes, cytosolic ALDH1 component and mitochondrial ALDH2 component, while human livers with "atypical" phenotype have only ALDH1 isozyme and are missing ALDH2 isozyme. Approximately 50% of orientals are atypical in respect to ALDH isozymes. We previously demonstrated an existence of enzymatically inactive but immunologically cross-reactive material (CRM) in atypical oriental livers. ALDH1 and ALDH2 isozymes were purified to homogeneity from usual livers, and ALDH1 and CRM were purified from atypical oriental livers. Amino acid compositions of ALDH1 and ALDH2 were similar to, but not identical with, each other. Amino acid compositions of ALDH2 and CRM were identical within analytical errors. Subunit molecular size of ALDH1 estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis was 56,200 daltons, and that of ALDH2 was 52,600 daltons. The two isozymes did not contain a common subunit. Subunit molecular weight of CRM was identical with that of ALDH2. Double immunodiffusion precipitation revealed that ALDH1 and ALDH2 were immunologically analogous but not identical, and that CRM and ALDH2 were immunologically indistinguishable. These results support the genetic model that CRM is an abnormal defective protein resulting from a mutation of the ALDH2 locus.

Aldehyde Dehydrogenase↗
PubMed1983

Retinal blood flow alterations during progression of diabetic retinopathy.

Alterations in retinal blood flow during the progression of diabetic retinopathy were studied using the dye-dilution technique. Mean fluorescein circulation times were measured in retinal arteriovenous segments with a two-point fluorophotometer in 48 diabetic patients and 20 normal controls. Monochromatic fundus photographs were used to determine vessel diameters. Segmental blood flow (SBF) increased with the progression of background diabetic retinopathy. In patients with distinct capillary closure, SBF was significantly higher than normal values.

Adult↗
PubMed1983

Myocardial energy metabolism of congestive and hypertrophic cardiomyopathy in man.

A key enzyme of glycolysis (pyruvate kinase) and main enzymes of the electron transport system (NADH cytochrome c reductase, succinic cytochrome c reductase, and cytochrome c oxidase) were measured in left ventricular biopsy specimens from six hypertrophic (HCM) and six congestive (CCM) cardiomyopathy. Pyruvate kinase was 104.0 and 45.0 mU/mg protein in HCM and CCM, respectively. NADH cytochrome c reductase, succinic cytochrome c reductase, and cytochrome c oxidase were 146.0, 9.9, and 775.0 mU/mg protein in HCM and 87.4, 5.2, and 502.0 mU/mg protein in CCM, respectively. From these data, it is evident that glycolysis and enzyme activities of the electron transport system are increased in HCM and decreased in CCM. Cardiac function reflects the state of these energy metabolism pathways in the myocardium. The changing energy metabolism in the right ventricle of the emphysema hamster seems to support this concept.

Animals↗
PubMed1983

The ventilatory response to hypoxia in the anesthetized rat.

The hypoxic ventilatory response of the anesthetized rat was measured using a progressive hypoxia test whilst end-tidal Pco2 was maintained at a constant level. The ventilatory response to hypoxia was expressed by the equation, VE = Vo + A/(Pao2-C)(VE, total ventilation in l BTPS . min-1; Pao2, arterial Po2 in mm Hg). The hypoxic ventilatory drive, A, averaged 4.1 +/- 2.5 1 . min-1 . mm Hg (mean +/- SD), from which a value of 252 1 . min-1 . mm Hg was calculated on the basis of appropriate allometric relationships, for a 70 kg body mass. This value is higher than those reported for the anesthetized dog and for human subjects. When end-tidal Po2 was gradually decreased from hyperoxia to normoxia, a significant increased in VE due to an increase in breathing frequency was observed, suggesting that the ventilation of the rat is maintained by a considerable 'hypoxic drive' even in normoxia. Furthermore, hypoxic ventilatory depression occurred at a relatively higher Pao2 level (45-60 mm Hg) than in other species. Thus, in the rat, the ventilation vs. end-tidal Po2 curve is shifted to the right compared to other species. After section of the carotid sinus nerve, the hypoxic drive (A) was reduced to 11%, indicating that almost all the ventilatory drive of hypoxia was mediated by the carotid chemoreceptors.

Anesthesia, General↗
PubMed1983

Amino acid sequence of the active site of human pseudocholinesterase.

The usual E1u and atypical E1a human pseudocholinesterases (acylcholine acylhydrolase, EC 3.1.1.8) were purified to homogeneity. The active-site serine residue was conjugated with diisopropyl fluorophosphate and digested with trypsin. The tryptic peptide containing the active site was isolated by gel filtration followed by two-dimensional paper chromatography and electrophoresis. The amino acid sequence of the active site peptide obtained from the usual E1u enzyme was found to be Gly-Glu-Ser-Ala-Gly-Ala-Ser-Ala-Val-Ser-Leu. A remarkable structural homology exists between the human and the horse enzymes in their active sites. From the difference in electrophoretic mobility of the active-site peptides obtained from the usual and atypical enzymes, the probable structure of the atypical human enzyme was deduced as Gly-His-Ser-Ala-Gly-Ala-Ser-Ala-Val-Ser-Leu.

Amino Acid Sequence↗