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Biomedical subjects

H Harada

Publications and source records attributed to H Harada.

At least 559 records · Page 31Linked to original sources

Formation of gamma-amino-beta-hydroxybutyric acid from 2-hydroxyputrescine in rat brain.

gamma-Amino-beta-[3H]hydroxybutyric acid ([3H]-GABOB) was formed in rat brain from 2-[3H]-hydroxyputrescine that had been chemically synthesized from 2-oxoputrescine and [3H]sodium borohydride. After the injection of 2-[3H]hydroxyputrescine into the lateral ventricle of a rat brain, the rat was killed and then the brain was removed. [3H]GABOB in the brain was identified by a combination of ion-exchange chromatography, high-voltage paper electrophoresis, and recrystallization of the radioactive compound with authentic GABOB.

Animals↗

A repeat sequence, GGGTTA, is shared by DNA of human herpesvirus 6 and Marek's disease virus.

Some regions of the genomes of human B-lymphotrophic virus (HBLV), also designated as human herpesvirus 6, and Marek's disease virus were found to hybridize to each other under moderate to stringent conditions, scoring from 10 to 30% base-pair mismatch. Nucleotide sequence analysis showed that a 6-base-pair repetitive sequence, GGGTTA (DR2), present in the IRS-IRL junction region of the Marek's disease virus genome, was also reiterated in the HBLV genome. The function(s) of such a sequence is unknown, but this is the first report of homology between HBLV and a nonhuman herpesvirus.

Animals↗

Attenuation of acute lung injury in septic guinea pigs by pentoxifylline.

Pentoxifylline (PTXF), a drug demonstrated to improve intermittent claudication, is a methylxanthine that increases intracellular cyclic AMP (cAMP) and, unlike theophylline, has few side effects. Because increased cAMP levels have been associated with a decrease in lung injury, we examined the effects of PTXF on acute lung injury in a septic guinea pig model. Five groups of guinea pigs were studied over a period of 8 h. (Group I: saline control injected intravenously with 2 ml of saline; Group II: septic control injected intravenously with 2 x 10(9) Escherichia coli; Group III: E. coli septicemia plus PTXF bolus 20 mg/kg injected 5 min before E. coli injection; Group IV: E. coli septicemia plus PTXF continuous infusion, begun with bolus [20 mg/kg] followed by continuous infusion [20 mg/kg/h] started 60 min before injection of E. coli; Group V: PTXF continuous infusion [20 mg/kg/h] control). Arterial blood gases, arterial blood pressure, and blood WBC counts were monitored serially for 8 h. Lung water (wet-to-dry ratio), the concentration ratio of 125I-labeled albumin in bronchoalveolar lavage (BAL) fluid to that in plasma (albumin index; AI), total cell count in BAL fluid, thiobarbituric-acid-reactive material (TBARM), and the lysosomal enzyme beta-glucuronidase (beta-G) were examined. Lung tissue was studied histologically to assess neutrophil accumulation. Our results showed that E. coli septicemia caused significant peripheral neutropenia and histopathologic evidence of neutrophil alveolitis associated with an increased ratio of TBARM and beta-G in BAL fluid as compared with those in plasma (TBARM BAL ratio and beta-G BAL ratio).(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗

Secretion of a novel cell-adhesive protein distinct from fibronectin by mouse L.P3 cells growing in protein- and lipid-free synthetic medium.

Several cell lines growing in protein- and lipid-free synthetic medium secreted cell-adhesive protein(s) into the medium. The conditioned medium (CM) of one of these cell lines, mouse L.P3, showed the highest cell attachment-promoting activity (CPA) among them. Cell-adhesive protein(s) in the CM of L.P3 cells (L.P3-CM) were separated into two types by sequential affinity column chromatography employing gelatin-Sepharose 4B and heparin-Sepharose 4B. One was a gelatin- and heparin-binding cell-adhesive protein (GCP), and was identified as a cellular form of mouse fibronectin. The other was a gelatin-non-binding and heparin-binding cell-adhesive protein (GNCP). The CPA of GNCP preparation was effective for the cell-attachment and spreading of both epithelial and fibroblastic cells. The CPA of GNCP preparation was not blocked by the antiserum and scarcely inhibited in the presence of the synthetic cell attachment-promoting peptide Gly-Arg-Gly-Asp-Ser-Pro, a competitive inhibitor of fibronectin. This suggests that the structure of the cell-attachment site of GNCP is different from that of fibronectin. The GNCP preparation showed little cross-reactivity with anti-mouse laminin antiserum in enzyme-linked immunosorbent assay (ELISA). These results demonstrate the possibility that GNCP in L.P3-CM is a novel cell-adhesive protein distinct from fibronectin or laminin. The secretion of the two types of cell-adhesive proteins by L.P3 cells is discussed.

Animals↗

Reduction of doxorubicin-induced cardiotoxicity in mice by taurine.

The effect of taurine on doxorubicin-induced cardiotoxicity was examined in mice. A single intraperitoneal injection of doxorubicin (15 mg/kg) produced a significant elevation of calcium and lipoperoxide content at 72 hr, as well as a significant depletion of creatine phosphokinase, glutamic oxaloacetic transaminase and lactate dehydrogenase activities at 48 hr and glutathione peroxidase activity at 24 hr in the myocardium. These results suggest that a substantial myocardial damage had occurred. All biochemical alterations except depletion of glutathione peroxidase, were markedly attenuated by the combined oral and intraperitoneal administration of taurine. Taurine significantly improved the survival rate of the mice treated with doxorubicin. These results demonstrate that taurine antagonized doxorubicin-induced cardiotoxicity.

Animals↗

Assay of glycosidase by lectin affinity high-performance liquid chromatography.

Human transferrin was incubated with sialidase and beta-galactosidase and then examined by lectin affinity high-performance liquid chromatography (HPLC). The elution patterns were changed according to the period of incubation and the amount of enzyme. This method of studying lectin affinity HPLC using human transferrin as a substrate makes possible the rapid and important detection of glycosidase activity.

Chromatography, High Pressure Liquid↗

Systematic fractionation of oligosaccharides of human immunoglobulin G by serial affinity chromatography on immobilized lectin columns.

Human immunoglobulin G is known to contain 16 different biantennary complex-type asparagine-linked sugar chains, each of which occurs in a nonsialylated, monosialylated, or disialylated form. These oligosaccharides can be separated into 14 fractions by sequential affinity chromatography with Aleuria aurantia lectin (AAL)-Sepharose, RCA120-WG003, and E4-phytohemagglutinin-agarose columns. Twelve of them were found to contain a single oligosaccharide, while the fraction which passed through all three columns was shown to contain two oligosaccharides, GlcNAc beta 1----2Man alpha 1----6(+/- GlcNAc beta 1----4) (GlcNAc beta 1----2Man alpha 1----3)Man beta 1----4GlcNAc beta 1----4GlcNAcOT. The fraction, which bound to the AAL-Sepharose column and passed through the remaining two lectin columns, also contained two oligosaccharides, GlcNAc beta 1----2Man alpha 1----6(+/- GlcNAc beta 1----4) (GlcNAc beta 1----2Man alpha 1----3)Man beta 1----4GlcNAc beta 1----4 (Fuc alpha 1----6)GlcNAcOT. These results indicated that serial affinity chromatography with the three lectin columns can be used effectively to detect changes in the sugar chains of IgG resulting from diseases such as rheumatoid arthritis.

Arthritis, Rheumatoid↗