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Biomedical subjects

A Yoshikawa

Publications and source records attributed to A Yoshikawa.

At least 91 records · Page 5Linked to original sources
PubMed1989

Purification and some properties of the small subunit of cytochrome b558 from human neutrophils.

We have attempted to purify the heme moiety of cytochrome b558 from human neutrophils. Cytochrome b558 was solubilized from the crude membrane fraction which was pretreated with both 1 M potassium phosphate buffer and 1% octyl glucoside at low ionic strength. The solubilization of cytochrome b558 was carried out efficiently with 1.6% octyl glucoside in the presence of 100 mM phosphate buffer. Solubilized cytochrome b558 was purified by hydroxylapatite, DEAE-Sephacel, and Mono Q fast protein liquid chromatography. The specific content of purified cytochrome b558 was 37 nmol/mg of protein. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of purified cytochrome b558 revealed a single band of 20,000 Da. The large subunit of cytochrome b558, which has been reported by others, could not be found in purified cytochrome b558 even with silver staining. The amino acid composition of the heme-containing moiety of cytochrome b558 was abundant in hydrophobic amino acids. The circular dichroism spectra of both oxidized and reduced b558-type cytochromes exhibited bilobed bands with wavelengths of crossover points closely corresponding to those of the maxima in the optical absorbance spectra at the Soret region. Furthermore, there were some differences in the shoulders and peak widths of CD spectra between oxidized and reduced b558-type cytochromes. These results indicate that this method provides the purification of the small subunit of human cytochrome b558 which is the heme-carrying subunit of cytochrome b558, and suggest that cytochrome b558 has heme-heme interaction and some conformational changes in the alternation of the redox state.

Amino Acids↗
PubMed1989

Thrombin and plasmin generation in patients with liver disease.

Patients with liver disease frequently have multiple hemostatic abnormalities. Coagulation and fibrinolytic factors and inhibitors may decrease as the result of impaired synthesis and/or enhanced catabolism. In order to assess the actual degree of activation of coagulation and fibrinolytic systems in liver disease, plasma levels of thrombin-antithrombin III complex (TAT) and plasmin-alpha 2-antiplasmin complex (PAP) were measured together with cross-linked fibrin derivatives (XDP), tissue-type plasminogen activator (t-PA), and plasminogen activator inhibitor (PAI-1) in 31 patients with liver disease (five patients with acute hepatitis, seven with chronic hepatitis, nine with liver cirrhosis, and ten with hepatocellular carcinoma). Mean plasma levels of TAT (mean 4.2 +/- SD 4.0 micrograms/L), PAP (0.7 +/- 0.7 mg/L), and XDP (374 +/- 518 micrograms/L) were significantly elevated in patients with liver disease as compared with normal subjects (TAT of 1.7 +/- 0.3 micrograms/L, PAP of 0.2 +/- 0.1 mg/L, and XDP of 30 +/- 14 micrograms/L; P less than 0.005). Plasma concentrations of t-PA and PAI-1 antigens were also elevated. When plotted by the disease categories, the magnitude of elevations of these parameters was variable among subgroups. Patients with acute hepatitis had considerably higher TAT levels. The mean PAP values were relatively high in chronic hepatitis and hepatocellular carcinoma, in which an elevation of the t-PA/PAI-1 ratio was observed. Although clearance of TAT and PAP should be evaluated in the future, these findings suggest that excessive amounts of thrombin and plasmin are actually generated in patients with liver disease.

Antithrombin III↗
PubMed1989

Cloning and molecular characterization of the gene rimL which encodes an enzyme acetylating ribosomal protein L12 of Escherichia coli K12.

The rimL gene of Escherichia coli K12 encodes an enzyme catalyzing the acetylation of the N-terminal serine of ribosomal protein L12, thereby converting it into L7. Using a mutant strain defective in this acetylation reaction, we cloned the rimL gene into cosmid pHC79 and characterized it at the molecular level. From analysis by SDS-polyacrylamide gel electrophoresis of the proteins synthesized in maxi-cells containing derivatives of the rimL-harboring plasmid into which transposon gamma delta had been inserted at various sites, the product of this gene was identified as a protein with an apparent molecular weight of 20.3 kDa. The nucleotide sequence of the gene and the amino acid sequence deduced from the nucleotide sequence were compared with those of two other ribosomal protein acetylases encoded by the rimI and rimJ genes (Yoshikawa et al. 1987). A considerable degree of overall similarity was seen between rimL and rimJ, but the degree of similarity between rimL and rimI was very low. In addition, a short stretch of similar amino acid sequence was found in all three rim acetylases. The significance of these results with respect to other acetylating enzymes, in particular those involved in the acetylation of aminoglycoside antibiotics is discussed.

Acetylation↗
PubMed1988

Augmentation rhinoplasty.

Augmentation rhinoplasty using a silicone implant is the most popular operation in Japan, but is not without several complications such as exposure of the implant and its deviation. We obtained good results in preventing these complications by a fixation at the hollow which is made by chiseling the frontal bone and by fibrous tissue which grows through the small holes of the implant tail.

Cleft Lip↗
PubMed1988

Reverse-flow anterior tibial flap type III.

A new anterior tibial flap has been designed. It is nourished by a single septocutaneous branch of the anterior tibial artery and its veins, running vertically through the anterior crural septum and appearing in the deep fascia of the lower half of the lower leg. This differs from the two other types of anterior tibial flap which have been reported and are nourished by different septocutaneous branches. We call our flap the anterior tibial flap type III in order to avoid confusion. We have applied it clinically in two cases as a reverse-flow island flap, anastomosing one vena comitans to a superficial vein at the edge of the wound in order to avoid venous congestion. Both flaps survived well with no problems.

Aged↗
PubMed1987

Cloning and nucleotide sequencing of the genes rimI and rimJ which encode enzymes acetylating ribosomal proteins S18 and S5 of Escherichia coli K12.

The rimI gene of Escherichia coli K12, which encodes an enzyme catalysing acetylation of the N-terminal alanine of ribosomal protein S18, has been cloned into a mini-F plasmid pRE432 and characterized at the molecular level. Similarly, the rimJ gene, which encodes another acetylating enzyme that is specific for ribosomal protein S5, has been cloned and characterized. From the nucleotide sequence data for the two genes the RimI enzyme was deduced to contain 161 amino acid residues with a calculated molecular weight (Mr) of 18232 and the RimJ enzyme contains 194 amino acid residues with a calculated Mr of 22687. The proteins produced from the two genes in maxi-cells were identified by electrophoresis on acrylamide gels and their operon structure was analysed by insertional mutagenesis with transposon gamma delta (Tn1000) and by measuring the size of their transcripts. Their structural homology was analysed by DNA hybridization and by calculation with computer programs. There is only a low level of overall homology between the two genes except for a 3' terminal region in which a significant degree of homology was noticed.

Acetylation↗
PubMed1987

[A case of B cell malignant lymphoma with in the liver and brain metastasis in Hashimoto's disease].

We have reported a case of malignant lymphoma in associated with Hashimoto's disease arising in the right lobe of thyroid of a 57-year-old woman. The pre-operative aspirated biopsy was valuable for diagnosis Immuno-histochemical observations revealed the localization of anti B cell antibody in the cell surface of lymphoma cells and anti thyroglobulin antibody in intactly follicular epithelium within the lymphoma tissue. This lymphoma was diagnosed as diffuse, medium cell and B cell type. Radiation and chemotherapy were performed for multiple metastasis of liver and brain, but this case had died of DIC and diffuse hyaline membrane disease of lung.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1985

Treatment of HBeAg-positive chronic hepatitis with a streptococcal preparation (OK-432).

Forty-two patients with hepatitis Be antigen (HBeAg)-positive chronic hepatitis were treated by intramuscular injections with OK-432, an immunopotentiator possessing interferon-inducing activity. They were monitored with serial measurements of virological parameters to evaluate therapeutic effectiveness, and compared with a group of seventy-five untreated patients (natural course group). In the group receiving OK-432 therapy, twenty-seven patients (64.3% of the forty-two patients) became negative for HBeAg in an average observation period of 20.1 months. Of these, fourteen patients (33.3% of the forty-two patients) underwent seroconversion from HBeAg to anti-HBe antibody (anti-HBe). In the natural course group, twenty-three patients (30.7% of the seventy-five patients) lost HBeAg reactivity in a mean follow-up period of 32.3 months, and thirteen patients (17.3% of the seventy-five patients) became seroconverted. Thus, the drug group showed significantly higher percentages of patients with disappearance of HBeAg and seroconversion, notwithstanding the shorter duration of the follow-up. Young males and females, females generally, or patients with high serum GPT levels were more likely to respond to the therapy. The serum GPT level tended to stabilize more in patients receiving OK-432.

Adult↗
PubMed1985

A case of primary ovarian pregnancy.

This report describes a 40-year-old woman with primary ovarian pregnancy which was mistaken clinically and grossly for germ cell tumor of the ovary, since it was associated with a high level of serum alpha-fetoprotein (278 ng/ml) and with excretion of urinary hCG (1 000 IU/l). The ovarian mass measured 10 X 10 X 11 cm, and weighed 215 g. Total hysterectomy and bilateral salpingo-oophorectomy were performed. The bisected specimen revealed a centrally located macerated fetus with a crown - rump length of 3.5 cm.

Adult↗
PubMed1984

Studies by immune electron microscopy of hepatitis B surface antigen in PLC/PRF/5 cells.

Electron microscopic studies of the morphology of hepatitis B surface antigen (HBsAg) produced by PLC/PRF/5 cells in vitro were carried out. Aggregates of 20-nm spherical particles in 3-day culture supernatants were observed by immune electron microscopy (IEM). Aggregates of tubular structures were found with IEM in the extracts of the cells. Tubular structures 18 to 22 nm in diameter were seen by electron microscopy (EM) in the cisternae of the endoplasmic reticulum in 2-3% of the cells. The tubular structures in the cytoplasm and extracts of PLC/PRF/5 cells resembled those observed in the hepatocytes of human carriers of hepatitis B virus (HBV). Intracellular localization of HBsAg in PLC/PRF/5 cells by direct peroxidase-conjugated antibody staining was observed on the tubular structures and the cisternal wall, which contained these structures. Rotation technique analysis indicated that the tubular structures were composed of 11 or 12 subunits.

Carcinoma, Hepatocellular↗