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Biomedical subjects

A Yoshida

Publications and source records attributed to A Yoshida.

At least 1,081 records · Page 60Linked to original sources
PubMed1983

Determination of genotypes of human aldehyde dehydrogenase ALDH2 locus.

Virtually all Caucasians have two major aldehyde dehydrogenase isozymes, ALDH1 and ALDH2, in their livers, while approximately 50% of Japanese and other Orientals are "atypical" in that they have only ALDH1 and are missing ALDH2. We previously demonstrated the existence of an enzymatically inactive but immunologically cross-reactive material (CRM) in atypical Japanese livers. Among 10 Japanese livers examined, five had ALDH1 but not ALDH2 isozyme. These are considered to be homozygous atypical at the ALDH2 locus. Four had both ALDH1 and ALDH2 components detected by starch gel electrophoresis, that is, they are apparently usual. However, biochemical and immunological studies revealed that three of these four livers contained CRM. These three livers should be heterozygous atypical in the ALDH2 locus, that is, genotype ALDH2(1)/ALDH2(2). A Japanese liver, as well as control Caucasian livers, had no CRM, and they must be homozygous usual ALDH2(1)/ALDH2(1). Although the number of liver specimens examined is limited, the frequencies of three genotypes determined in this study are compatible with the values calculated based on the genetic model that two common alleles ALDH2(1) and ALDH2(2) for the same locus are codominantly expressed in Orientals. The remaining liver had only ALDH2 isozyme and was missing ALDH1. This type was not previously found in Caucasians and Orientals. The two-dimensional crossed immunoelectrophoresis revealed the existence of a CRM corresponding to ALDH1 in this liver. The abnormality can be considered to be due to structural mutation at the ALDH1 locus producing a defective ALDH1 molecule, although other possibilities such as post-translational modifications are not ruled out.

Aldehyde Dehydrogenase↗
PubMed1983

Phosphoglycerate kinase abnormalities: functional, structural and genomic aspects.

Phosphoglycerate kinase (PGK) deficiency is associated with hemolytic anemia and mental disorders in man. Complete amino acid sequence of normal human PGK was determined and its three-dimensional structure could be deduced from that of horse and yeast enzymes. Specific amino acid substitutions of several PGK variants associated with clinical problems were elucidated, and their functional abnormalities were correlated to their structural abnormalities. Full-length cDNA clones for normal human PGK were isolated and it is possible to examine PGK variants at the genomic level.

Amino Acid Sequence↗
PubMed1982

Change of enzyme properties caused by cross-linking treatment of human erythrocytes.

Aragon et al [4] reported that rat erythrocytes can be cross-linked and permeabilized without significant inactivation or alterations of several enzymes in the glycolytic pathway. If this is the case, in situ kinetic analysis of the red cell enzymes in normal human red cells and abnormal red cells associated with hemolytic problems could be performed. However, we found that the treatment of human red cells with several bifunctional cross-linking reagents under various conditions always caused a certain extent of inactivation and a change in kinetic properties of glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, and lactate dehydrogenase. Thus, the cross-linking and permeabilization method, as it stands, is not satisfactory for in situ kinetic analysis of red cell enzymes.

Cell Membrane Permeability↗
PubMed1982

Abnormal blood group galactosyltransferase in blood type A1B-subjects whose sera contain anti-B agglutinin.

A blood type A1B female, whose plasma agglutinates B red blood cells from other subjects but not her own, was found. Her sister with blood type A1B (sister-1) exhibited the same peculiarity. The agglutination titer of red cells from these two subjects is lower than that of normal B. Her father is blood type B, and his plasma did not agglutinate B red cells from other subjects and his own. Her mother and another sister (sister-2) were usual blood type A1. Blood group galactosyltransferase (B-enzyme) activity of plasma from the propositus, sister-1, and their father was very low. Km for 2'-fucosyllactose of B-enzyme of these subjects was 1.3 mM, which was more than two times higher than that of the normal value. Km for UDP-Gal was similar, but the pH-activity profile differed for the two enzymes. Red cell membranes from her father contained about 70% ungalactosylated H-sites, whereas, virtually all H-sites are galactosylated in the usual B red cell membranes. The blood group ABH components are known to be heterogeneous. Because of the abnormal B-enzyme with low activity and low substrate affinity, some H components might not be galactosylated, particularly in A1B cases (i.e., the propositus and her sister-1), due to competition by A1 enzyme. The lack of certain B components is likely to be the cause of the existence of the anti-B agglutinin in their sera.

ABO Blood-Group System↗
PubMed1982

Choriocarcinomatous change with immunocytochemically HCG-positive cells in the gastric carcinoma of the males.

Gastric choriocarcinoma is a rare tumor and attracts interest because of its controversial pathogenesis. The present study reports a choriocarcinomatous change with immunocytochemically hCG-positive cells in the gastric carcinoma. The patients were males, one was 41 years old and the other 42 years old. The tumor of both cases consists of adenocarcinoma and choriocarcinoma. A sequential process of morphological transition of the adenocarcinoma to the choriocarcinoma can be traced. Indirect immunoperoxidase stain (PAP method) for human chorionic gonadotropin (hCG) demonstrates the localization of hCG in the syncytiotrophoblasts. Small number of cytotrophoblasts are weakly positive. None of the components of adenocarcinoma of both cases is positive for hCG. Human placental lactogen is not demonstrated in both cases. Stain for pregnancy specific beta-1 glycoprotein is weakly positive in the adenocarcinoma of one case but not in the choriocarcinoma. In one case, the concentration of hCG was 19.9 mIU/ml in the preoperative serum and decreased to 1.2 mIU/ml after gastrectomy. HCG production by gastric carcinoma was discussed with regard to possible pathogenesis of gastric choriocarcinoma.

Adenocarcinoma↗
PubMed1982

CO2-ventilatory response of the anesthetized rat by rebreathing technique.

The ventilatory response to CO2 in rats under sodium pentobarbital anesthesia has been measured using the rebreathing technique. The animal rebreathed through a tracheal cannula for a period of 4 min from an apparatus of 200-400 ml capacity, containing 5-6% CO2 in O2. Pco2 in the rebreathing apparatus (PappCO2), instantaneously Vt, f, and Ve were monitored before, during, and after rebreathing. During the rebreathing run, PappCO2 and Paco2 rose linearly from 35-40 to 65-70 mm Hg; there was no significant difference between PappCO2 and Paco2 at any time during rebreathing. Vt and Ve increases almost linearly with the rise of PappCO2, while f increased to a maximum within 2 min of rebreathing. In the rat, Vt regulation seemed to operate exclusively as a proportional control system in response to linearly increasing CO2 stimulus. The slopes of PappCO2, Vt or Ve response curves varied considerably during the time course of the experiment, depending upon the level of anesthesia, even though there was no large change in Ve in the control periods which were under hyperoxic conditions. However, a significant linear relationship was seen between f in the respective control period and the slope of PappCO2-Vt response at various levels of anesthesia. We concluded that the rebreathing technique can be applied in small experimental animals and that changes in the sensitivity of the respiratory control system to a CO2 stimulus by anesthesia can be easily monitored by repeating the rebreathing test.

Anesthesia, General↗
PubMed1982

Ocular manifestations of Kawasaki's disease (mucocutaneous lymph node syndrome).

In a prospective study of the ocular manifestations of Kawasaki's disease (mucocutaneous lymph node syndrome) in 18 children (11 boys and seven girls, ranging in age from 5 months to 9 years), we found bilateral injection of the bulbar conjunctiva in 16, bilateral iridocyclitis in 14, superficial punctate keratitis in four, vitreous opacities in two, papilledema in two, and subconjunctival hemorrhage in one. Conjunctival injection and iridocyclitis were always bilateral, and fellow eyes always had the same degree of inflammation. There were significant correlations between ocular inflammation and erythrocyte sedimentation rate (P less than .0001) and C-reactive protein level (P less than .0009). No serious ocular complications occurred.

Blood Sedimentation↗
PubMed1982

Effects of some xenobiotics on ascorbic acid metabolism in rats.

The administration of xenobiotics, PCB, DDT, or aminopyrine to rats causes a marked increase in urinary excretion of ascorbic acid and in various tissue levels of ascorbic acid. When rats were fed diet containing 200 ppm PCB or 500 ppm DDT (14 days), the incorporations from D-(U-14C) glucose into ascorbic acid in liver were significantly increased. The dietary addition of 200 ppm PCB, 500 ppm DDT, 2,000 ppm pentobarbital or 3,000 ppm chloretone caused a significant increase in the activity of hepatic UDPglucose dehydrogenase, but did not affect the activity of hepatic L-gulonolactone oxidase. Good correlation between the liver level of ascorbic acid and the activity of hepatic UDPglucose dehydrogenase was observed. Subsequently, in rats fed the basal diet (30% casein diet) or the diet containing 200 ppm PCB, the specific activities of ascorbic acid in urine and in various tissues were measured 6 hours, 12 hours and 24 hours after the oral administration of L-(l-14C)ascorbic acid. Dietary PCB accelerated the disappearances of radioactivities in ascorbic acid in urine and various tissues, that is, shortened the half lives of radioactivities in ascorbic acid. It is likely that the administration of xenobiotics, such as PCB or DDT, to rats increases the biosynthesis of ascorbic acid and accelerates concomitantly the turnover of ascorbic acid in body.

Aminopyrine↗
PubMed1982

Effect of dietary level of sulfur-containing amino acids on liver drug-metabolizing enzymes, serum cholesterol and urinary ascorbic acid in rats fed PCB.

Effects of dietary level of sulfur-containing amino acids (S-AA) on liver drug-metabolizing enzymes, serum cholesterol and ascorbic acid metabolism in growing rats fed diets containing 300 ppm of polychlorinated biphenyls (PCB) were investigated. Maximum gain in body weight was observed with 0.5% S-AA diets with or without PCB addition. Metabolic parameters increased by PCB were liver weight, activities of hepatic aminopyrine N-demethylase and aniline hydroxylase, serum total cholesterol, serum high density lipoprotein cholesterol, serum corticosterone and urinary metabolites of the glucuronic acid pathway including ascorbic acid, glucuronic acid and glucaric acid. In the PCB-treated animals, maximum values of liver weight, aminopyrine demethylase activity, serum cholesterol, serum corticosterone, urinary ascorbic acid and glucaric acid were obtained with about 0.8% S-AA. For the maximum induction of these metabolic responses, 0.5% S-AA was not enough. Urinary glucuronic acid and the ratio of lower density lipoprotein cholesterol versus high density lipoprotein cholesterol were decreased with a supplement of S-AA to PCB-containing diets.

Amino Acids, Sulfur↗
PubMed1982

Biosynthesis of lactosylceramide and paragloboside by human lactose synthase A protein.

Lactosylceramide and paragloboside were synthesized from their precursor glycolipids and UDP-galactose by lactose synthase A protein [UDP-Gal : GlcNAc beta-4-galactosyltransferase, EC 2.4.1.22] purified to homogeneity from human plasma. The partially purified human liver enzyme and an extract from human lymphoblastoid cells also exhibited the above activities. Rabbit antibody against the purified human plasma lactose synthase A protein neutralized the glycolipid synthesis activity as well as the activity for lactose synthesis by the enzyme preparations from plasma, liver and lymphoblastoid cells. These results suggest that lactose synthase A protein existing in plasma, liver and lymphoblastoid cells can synthesize not only lactose but also lactosylceramide and paragloboside in vitro. The enzyme could play a role in the synthesis of these two glycolipids in vivo.

Animals↗
PubMed1982

Purification and chemical characterization of human acidic alpha-D-mannosidase.

The acidic alpha-D-mannosidase (EC 3.2.1.24) has been purified from human placentae. Milligram quantities of the enzyme were obtained from several placentae, using a step-wise purification procedure which includes Con A-Sepharose treatment, acetone precipitation, heat treatment, DEAE-cellulose column chromatography and preparative disc electrophoresis. A high degree of purity of the purified enzyme was demonstrated by acrylamide gel electrophoresis, isoelectric focusing, and sedimentation equilibrium centrifugation. Immunological homogeneity of the preparation was demonstrated by a single precipitin line between the antiserum and purified, or partially purified enzyme preparation. The amino acid and carbohydrate composition of the enzyme was determined. The enzyme was found to be a glycoprotein containing 13.5% carbohydrate. The molecular weight of the enzyme was estimated at 205,000 +/- 18,400.

Amino Acids↗
PubMed1982

Estimation of infarct size by myocardial emission computed tomography with thallium-201 and its relation to creatine kinase-MB release after myocardial infarction in man.

We evaluated emission computed tomography (ECT) for thallium-201 (201TI) myocardial imaging in estimating infarct size (IS). In 18 patients in whom IS was estimated enzymatically at the time of the acute episode, planar 201TI perfusion scintigraphy and ECT with a rotating gamma camera were performed 4 weeks after the first myocardial infarction. From the size of 201TI perfusion defects, the infarct area in planar images and the infarct volume in reconstructed ECT images were measured by computerized planimetry. When scintigraphic IS was compared with the accumulated creatine kinase-MB isoenzyme release (CK-MBr), infarct volume determined from ECT correlated closely with CK-MBr (r = 0.89), whereas infarct area measured from planar images correlated less satisfactorily with the enzymatic IS (for an average infarct area from three views, r = 0.69; for the largest infarct area, r = 0.73). Although conventional scintigraphic evaluation is useful for detecting and localizing infarction, quantification of ischemic injury with this two-dimensional technique has a significant inherent limitation. The ECT approach can provide a more accurate three-dimensional quantitative estimate of infarction, and can corroborate the enzymatic estimate of IS.

Adult↗