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Biomedical subjects

H Itakura

Publications and source records attributed to H Itakura.

At least 127 records · Page 7Linked to original sources
PubMed1992

Endocarditis caused by Candida parapsilosis.

The authors report a case of endocarditis caused by Candida parapsilosis. To the best of our knowledge, a case has not been described previously in Japan in the English literature. A battery of 8 peroxidase-labeled lectins was tested on sections of paraffin-embedded tissue to determine which lectin could be used in the microscopic diagnosis of C. parapsilosis. One lectin, from Archis hypoaea (PNA) was found to react with C. parapsilosis. On the other hand, C. albicans, Aspergillus, Mucor, and Cryptococcus did not react with A. hypoaea (PNA). On fluorescence microscopic study, C. parapsilosis was not fluorescent, but other fungi were fluorescent when exposed to ultraviolet illumination. Therefore, we propose new procedures for identification of C. parapsilosis in tissue sections using lectin histochemistry and fluorescence microscopy.

Candidiasis↗
PubMed1990

Human monocyte colony-stimulating factor enhances the clearance of lipoproteins containing apolipoprotein B-100 via both low density lipoprotein receptor-dependent and -independent pathways in rabbits.

To investigate the effects of recombinant human monocyte colony-stimulating factor (M-CSF) on plasma cholesterol metabolism, we injected M-CSF intravenously into New Zealand White rabbits (n = 13) at a dose of 100 micrograms/day for 7 days. After the treatment, the plasma cholesterol levels fell by 33.2% from 61.4 +/- 25.9 to 41.0 +/- 10.2 mg/dl (mean +/- S.D.). We also injected a large dose of M-CSF (500 micrograms/day) for 6 days into Watanabe Heritable Hyperlipidemic rabbits, which are deficient in low density lipoprotein (LDL) receptors. Again, there was a significant reduction in plasma cholesterol levels by 36.2% from 730.5 +/- 176.4 to 466.0 +/- 104.9 mg/dl (n = 4). In the kinetic studies in New Zealand White rabbits with very low density lipoprotein, LDL, and methylated LDL, the removal rates of those lipoproteins were increased 1.9-, 1.7-, and 2.0-fold, respectively, after the treatment. Immunoblot analysis of LDL receptors in the treated rabbits showed no significant changes in LDL receptor proteins in livers but a great increase in spleens and bone marrows compared with the controls. Messenger RNA was also estimated by Northern blotting in both groups, and the results were compatible with those from the immunoblot. The data suggest that M-CSF stimulates the clearance of lipoproteins containing apolipoprotein B-100 via both LDL receptor-dependent and -independent pathways in target cells of M-CSF and reduces plasma cholesterol.

Animals↗
PubMed1990

Isolation and characterization of a cDNA for rat liver cysteine dioxygenase.

Cysteine dioxygenase is a key enzyme of cysteine metabolism in mammals. The cDNA clones for rat liver cysteine dioxygenase were isolated by immunological screening and plaque hybridization from a rat liver cDNA library. The longest clone contained an insert of 1458 bp and encoded a polypeptide of 200 amino acids. The clone included the corresponding nucleotide sequence to amino acid sequences obtained from four lysyl endopeptidase-digested fragments of purified rat liver cysteine dioxygenase. The calculated molecular weight of rat liver cysteine dioxygenase was 23,025. Northern blot analysis revealed a single cysteine dioxygenase mRNA species of about 1.7 kb. A computer homology search indicated that this protein showed no homology with any known protein.

Amino Acid Sequence↗
PubMed1990

Human macrophage scavenger receptors: primary structure, expression, and localization in atherosclerotic lesions.

Two types of cDNAs for human macrophage scavenger receptors were cloned from a cDNA library derived from the phorbol ester-treated human monocytic cell line THP-1. The type I and type II human scavenger receptors encoded by these cDNAs are homologous (73% and 71% amino acid identity) to their previously characterized bovine counterparts and consist of six domains: cytoplasmic (I), membrane-spanning (II), spacer (III), alpha-helical coiled-coil (IV), collagen-like (V), and a type-specific C-terminal (VI). The receptor gene is located on human chromosome 8. The human receptors expressed in CHO-K1 cells mediated endocytosis of modified low density lipoproteins. Two mRNAs, 4.0 and 3.2 kilobases, have been detected in human liver, placenta, and brain. Immunohistochemical studies using an anti-peptide antibody which recognizes human scavenger receptors indicated the presence of the scavenger receptors in the macrophages of lipid-rich atherosclerotic lesions, suggesting the involvement of scavenger receptors in atherogenesis.

Amino Acid Sequence↗
PubMed1990

Role of two types of glucose transporters in enlarged adipocytes from aged obese rats.

The mechanism of insulin-resistant glucose-transport activity in enlarged aged adipocytes was examined. Glucose-transport activity was assessed by measuring 3-O-methylglucose transport and the concentration of HepG2 erythrocyte/glucose transporter (GLUT1), and the muscle/adipose tissue transporter (GLUT4) was estimated by immunoblotting. Basal glucose-transport activity increased 6.3-fold/cell but remained constant per unit cellular surface area due to cell enlargement. Maximal insulin-stimulated transport activity remained constant per cell but decreased per unit cellular surface area. On a per protein basis, GLUT1 and GLUT4 from aged rats decreased to approximately 60 and 10% of those from young rats, respectively. However, when the protein content of each fraction and the recoveries of marker enzymes were used for estimating the amount of transporters in intact adipocytes, the amount of GLUT1 per cell remained relatively constant, whereas that of GLUT4 decreased. In basal cells from young rats, 31% of the total GLUT1 per cell was located in the plasma membrane, whereas in those from aged rats, 63% was located in the plasma membrane. Thus, in comparing basal adipocytes from aged rats with those from young rats, GLUT1 per cell in the plasma membrane increased 2.8-fold, but this increase was less than that of transport activity (6.3-fold). In basal cells from young rats, 8% of the total GLUT4 was located in the plasma membrane, and a 4.5-fold increase was observed with insulin treatment, but the amount of GLUT4 in each fraction from aged rats markedly decreased.(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗
PubMed1990

[Kaposi's sarcoma].

Kaposi's sarcoma (KS) (Kaposi, 1872) is classified into at least three forms: 1) the classic form; in elderly men of southern European, Jewish, and Italian origin, 2) the endemic form; among native populations in equatorial Africa and 3) the epidemic form; as a complication of AIDS. As one additional form could be posttransplantation KS in organ transplant recipients. Histologically, KS is composed of two characteristic features; a proliferation of angiomatous lesion and of spindle-shaped cells. The pathological entity of the disease is still controversial. As a cause of the disease, human cytomegalovirus (HCMV) has been the subject based on epidemiologic, serologic, geopathologic and histopathologic observations. About half of KS cases with AIDS has shown evidence of HCMV infection as cytomegalic viral inclusions of the cells. In contrast, about 30% of AIDS cases without KS showed histological HCMV infection. A connection between HCMV and KS was suggested by the detection of herpes-type virus particles in several KS tissue culture lines and in a tumor specimen. DNA and RNA homologous with HCMV sequences have been detected in tumor tissue of both endemic and epidemic KS by electrophoretic methods. HCMV sequences was detected in extracted DNA of 30% of classic KS, using Southern blot technique. In situ hybridization technique using specific DNA probes for HCMV has been developed to reveal endogenous nucleic acid sequences in fixed tissue sections. However, some reports showed that by the in situ technique only a small number of KS cells in the AIDS cases and no case of the classic KS were positive for HCMV within KS lesions. HCMV infections are ubiquitous. There is a very high seropositivity of HCMV in African inhabitants as well as in Africans with endemic KS. A strong association between HCMV and KS was not known. As for HIV itself in AIDS with KS, previous studies have showed the presence of chromosomal abnormalities of KS cells, but not revealed the presence of HIV DNA sequences in KS. Vascular tumors were produced by NIH/3T3 cells transfected with KS DNA of AIDS. An oncogene isolated by transfection of KS DNA encodes a growth factor; FGF. Isolation of rearranged human transforming gene following transfection of KS DNA was performed. DNA having transforming genetic elements which have been repetitively transmitted into phenotypically normal NIH/3T3 cells through cycles of transfection was isolated from tissues of KS with AIDS.(ABSTRACT TRUNCATED AT 400 WORDS)

Acquired Immunodeficiency Syndrome↗
PubMed1989

Co-localization of a glucose transporter and the insulin receptor in microsomes of insulin-treated rat adipocytes.

Microsomal vesicles prepared from rat adipocytes were immuno-adsorbed to formaldehyde-fixed Staphylococcus aureus cells (Pansorbin) coated with anti-human-erythrocyte-glucose-transporter IgG. More than 75% of the glucose transporter detected was precipitated. The glucose transporter was about 10-fold enriched by the adsorption procedure. On insulin treatment, the insulin receptor in plasma membranes was internalized and the receptor in the microsome fraction increased 5-fold. Thirty-five % of the insulin receptor in the microsome fraction was recovered with the glucose-transporter-containing vesicles. These observations indicate that on insulin treatment a considerable portion of the microsome vesicles containing the insulin receptor fuses or becomes tightly associated with ones containing the glucose transporter.

Adipose Tissue↗
PubMed1989

Single base substitution between human intestinal and hepatic apolipoprotein B mRNA detected by ribonuclease cleavage analysis.

The molecular mechanism of human intestinal apolipoprotein (apo) B-48 synthesis has been elucidated by a combination of sequencing of cloned complementary DNAs and RNase cleavage analysis of RNA heteroduplex. All intestinal cDNA clones contained a single C to T base substitution in the codon CAA encoding Gln2153 in apoB-100 cDNA, resulting in a translational stop. One of the our intestinal apoB cDNA clones was polyadenylated 106 bases downstream from the stop codon, possibly producing a 7-kb apoB message in the intestine. RNase cleavage analysis of the RNA heteroduplex between hepatic or intestinal RNA and apoB cDNA-directed anti-sense RNA showed that this single C to U substitution may occur in most of intestinal apoB mRNA. These results suggested that human apoB-48 is mostly produced by apoB mRNA with an in-frame stop codon in the intestine.

Apolipoproteins B↗
PubMed1989

[Intravesical BCG therapy in patients with recurrent superficial bladder tumors].

Intravesical instillation of BCG has recently become a treatment for superficial bladder tumor, and favorable results are reported. We have also obtained favorable results by performing intravesical BCG therapy to totally 32 cases of superficial recurrent bladder tumor and carcinoma in situ (CIS) one indicated for total cystectomy. The subjects were 29 cases of Ta and T1 and 4 cases of Tis, which are classified into 27 cases for treatment and 5 cases for prevention of recurrence after TUR. As the method for administration, 120 or 80 mg of BCG was dissolved in physiological saline and infused intravesically every week a total of 8 times. As a result of designating the patients who received the treatment more than 4 times as the subject, CR and PR were 19 cases (73%) and 5 cases (19%), or respectively, out of 26 assessable cases, and effective rate including PR was 93%. No recurrence has been observed so far in any of 5 cases treated for prevention of recurrence. Side effects which required treatment were observed in 13 cases (41%), but treatment could be continued by symptomatic therapy in most of the cases. Treatment was discontinued in 4 cases, 3 of which were hepatic disorders. It is considered that intravesical instillation of BCG is a therapeutic procedure which is good for trial in future in the light of the great efficacy obtained in the present study.

Administration, Intravesical↗
PubMed1988

Increased levels of messenger ribonucleic acid for apolipoprotein E in the spleen of probucol-treated rabbits.

To study the organ-specific effect of probucol, a potent cholesterol-lowering drug, on apolipoprotein(apo)E synthesis, rabbit apoE complementary deoxyribonucleic acid (cDNA) clones were isolated and apoE messenger ribonucleic acid (mRNA) levels were determined in various tissues isolated from probucol-treated rabbits. A 0.54 kb apoE cDNA was cloned from a rabbit liver cDNA library using a synthetic oligonucleotide probe. The amino acid sequence deduced from an apoE coding region indicated 78% homology for human apoE and 63% homology for rat apoE. RNA blot analysis showed that apoE mRNA was most abundant in the liver, then in the brain and spleen. The relative amounts of apoE mRNA were determined in tissues of rabbits fed a normal diet, or high-cholesterol (1%) diet with or without probucol (1%). ApoE mRNA levels increased 2- to 4-fold in the spleen and brain after cholesterol feeding for 4 weeks and were higher by 52 to 70% in the spleen of probucol-treated rabbits than in nontreated rabbits. This induction of apoE mRNA occurs within 7 days after the initiation of probucol treatment. However, apoE mRNA levels in the liver, a major apoE-synthesizing organ, were not enhanced after probucol treatment. These results indicate that probucol induces apoE mRNA expression specifically in the spleen and may affect apoE-mediated lipoprotein metabolism, the so-called reverse cholesterol transport.

Amino Acid Sequence↗
PubMed1988

A study of DNA polymorphism in the apolipoprotein B gene in a Japanese population.

A Japanese group comprising 53 hyperlipidemic and 54 normolipidemic subjects was genotyped for DNA restriction fragment length polymorphisms (RFLPs) at the apo B gene locus. The polymorphisms with XbaI and PvuII were present at allelic frequencies of 0.04 (X1 allele) and 0.96 (X2 allele), 0.94 (P1 allele) and 0.06 (P2 allele), respectively. Unlike the previous reported association of the X1 allele with hypercholesterolemia found in Caucasians there was no difference in the frequency of the X1 allele between normolipidemic and hypercholesterolemic Japanese. Among the Japanese, two RFLPs appear to be in linkage equilibrium and can be used in conjunction as a haplotype. There is no strong population association in our patient group between any allele of the RFLPs studied and hyperlipidemia.

Adult↗
PubMed1988

Deoxyribonucleic acid (DNA) polymorphism in the apolipoprotein AI gene: a study in a Japanese population.

A Japanese group comprising 54 hyperlipidemic and 73 normolipidemic subjects were genotyped for DNA restriction fragment length polymorphisms (RFLPs) at the apoAI-CIII gene locus. The polymorphisms with Sstl were present at allelic frequencies of 0.63 (S1 allele) and 0.37 (S2 allele). Unlike the previously reported associations of the S2 allele with hypertriglycedemia found in Caucasians there was no difference in the frequency of S2 allele between normolipidemic and hyperlipidemic Japanese subjects. No significant association of genotypes were observed with serum levels of lipids and apolipoproteins, except for the association of the S2 allele with the higher mean level of HDL-cholesterol. In addition, among 26 patients who had coronary artery disease (CAD), as documented by angiography, there was no significant difference in the distribution of polymorphic alleles between CAD patients and normolipidemic control subjects.

Alleles↗