K Seiki

Dokkyo Medical University, Tochigi, Tochigi-ken, Japan

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Publications (7)36.86 Total impact

  • Article: Charge microheterogeneity of the beta-trace proteins (lipocalin-type prostaglandin D synthase) in the cerebrospinal fluid of patients with neurological disorders analyzed by capillary isoelectrofocusing.
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    ABSTRACT: Charge microheterogeneity of the beta-trace protein (beta-TP = lipocalin-type prostaglandin D synthase) in the cerebrospinal fluid (CSF) of patients with various neurological disorders was analyzed by capillary isoelectric focusing (CIEF). Under the conditions employed, beta-TP in the low-molecular-weight protein fraction of CSF was separated into at least four isoforms with different p/ values. An isoform with the pl value of 4.6-4.8 was usually the most abundant. The total beta-TP level in the CSF was determined by enzyme-linked immunosorbent assay (ELISA) to be elevated in patients recovering from organic damage to the CNS and those with pathological brain atrophy. Changes in the total beta-TP level in the CSF were occasionally accompanied by those in its charge microheterogeneity, as revealed by CIEF. Such quantitative and qualitative changes in beta-TP in human CSF indicated changes in its pathophysiological roles in association with various neurological disorders.
    Electrophoresis 11/2001; 22(16):3433-7. · 3.30 Impact Factor
  • Article: Urinary prostaglandin D synthase (beta-trace) excretion increases in the early stage of diabetes mellitus.
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    ABSTRACT: Circulating levels of lipocalin-type prostaglandin D synthase (L-PGDS)/beta-trace reportedly increase in renal failure as well as in cardiovascular injuries. We investigated the alterations of L-PGDS in urine and plasma in the early stage of type-2 diabetic patients. Thirty-six type-2 diabetic patients and 29 normal subjects were studied. Overnight spot urine and plasma samples were obtained in the morning. L-PGDS was measured by ELISA method using anti-L-PGDS antibody. Variables indicating renal function were determined. Plasma L-PGDS concentration was slightly higher in the patients with diabetes mellitus than in the control subjects, whereas the urinary L-PGDS excretion almost doubled in the diabetic patients as compared with that in the control subjects. Plasma L-PGDS was determined by plasma creatinine (Cr) concentration while urinary L-PGDS excretion was correlated solely with urinary protein excretion. There was no relationship between plasma L-PGDS concentration and urinary L-PGDS excretion. The averaged plasma concentration of L-PGDS in the diabetics with a normal Cr level in plasma, corresponding to that in the controls, was determined by the plasma Cr concentration. On the other hand, the urinary L-PGDS excretion was determined by the amount of proteinuria and greater in the diabetics with a normal Cr level in plasma than in the controls even when the patients exhibited urinary protein excretion equal to that in the control subjects. Urinary L-PGDS excretion increased in the early stage of kidney injury in patients with type-2 diabetes mellitus. The urinary excretion was correlated independently with urinary protein excretion even when there was no difference in urinary protein or albumin excretions, thereby suggesting that urinary L-PGDS excretion is possibly a more sensitive indicator of renal injuries than proteinuria. Urinary L-PGDS may thus predict the progression of renal injuries in diabetic patients.
    Nephron 05/2001; 87(4):321-7. · 13.26 Impact Factor
  • Article: Serum prostaglandin D synthase level after coronary angioplasty may predict occurrence of restenosis.
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    ABSTRACT: Lipocalin-type prostaglandin D synthase (L-PGDS), which is responsible for the biosynthesis of PGD2, has recently been found to be present in the atherosclerotic plaque of the human coronary artery and also to be secreted in human serum. We measured the serum L-PGDS level and compared it with the expressions of the platelet membrane surface glycoprotein and neutrophil adhesion molecule in patients undergoing PTCA. The L-PGDS level significantly decreased (P < 0.01) and the platelet surface expression of CD62P (P-selectin) significantly increased (P < 0.01) immediately after PTCA in the coronary sinus blood. Both changes were inversely correlated (R = -0.72, P < 0.001). Although the L-PGDS level in the coronary sinus blood remained equivalent to the baseline level in patients who experienced restenosis, the level increased over the baseline level (P < 0.01) at 48 h after PTCA in patients without restenosis. Neutrophil surface expression of CD11b (alpha subunit of Mac-1) significantly increased at 24 h (P < 0.01) to 48 h (P < 0.001) after PTCA in the coronary sinus blood in patients with restenosis but the change showed less significant in patients without restenosis. The changes in the L-PGDS level and the CD11b expression at 48 h after PTCA were inversely correlated (R = -0.55, P < 0.05). An increased serum L-PGDS level at 48 h after PTCA possibly predicts the avoidance of late restenosis. It is suggested that reduction in PGD2 synthesis triggers platelet activation and that a subsequent increase in the PGD2 synthesis suppresses inflammatory reaction at the intervention site indicated by neutrophil activation and inhibits development of restenosis. Pharmacological or biological intervention that increases endogenous PGD2 synthesis should be tested as a new strategy to prevent restenosis.
    Thrombosis and Haemostasis 01/2001; 85(1):165-70. · 5.04 Impact Factor
  • Article: Comparative study of the asparagine-linked sugar chains of human lipocalin-type prostaglandin D synthase purified from urine and amniotic fluid, and recombinantly expressed in Chinese hamster ovary cells.
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    ABSTRACT: Lipocalin-type prostaglandin D synthase (L-PGDS) is a highly glycosylated member of the lipocalin gene family and is secreted into various human body fluids. We comparatively analyzed the structures of asparagine-linked sugar chains of human L-PGDS produced by recombinant Chinese hamster ovary cells and naturally occurring human urine and amniotic fluid. After the sugar chains were liberated by hydrazinolysis followed by N-acetylation, they were derivatized with 2-aminobenzamide. All of the sugar chains of three L-PGDSs occur as biantennary complex-type sugar chains. Most of the sugar chains of three samples were fucosylated on the inner most N-acetylglucosamine residue. Although the sugar chains of the recombinant L-PGDS do not contain any bisecting N-acetylglucosamine residues, 58% and 34% of the fucosylated-sugar chains of amniotic fluid and urine L-PGDSs, respectively, contain bisecting N-acetylglucosamine residues. The sialic acid residues occur solely as Siaalpha2-->3Gal groups of the recombinant L-PGDS; the sialic acid residues of other L-PGDS occur as both Siaalpha2-->3Gal and Siaalpha2-->6Gal groups. Variations in L-PGDS glycosylation may prove useful as markers to further elucidate the role of L-PGDS glycoforms in different tissues.
    Journal of Biochemistry 07/2000; 127(6):1001-11. · 2.37 Impact Factor
  • Article: Acute and transient increase of lipocalin-type prostaglandin D synthase (beta-trace) level in cerebrospinal fluid of patients with aneurysmal subarachnoid hemorrhage.
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    ABSTRACT: We measured the concentration of lipocalin-type prostaglandin D synthase (PGDS) in cerebrospinal fluid (CSF) and serum in patients 1, 3, 5, 7, 9, 11, 14 and 17 days after subarachnoid hemorrhage (SAH) due to ruptured cerebral aneurysms. The PGDS level in lumbar CSF increased about two-fold at day 3 (20.85 +/- 2.71 microg/ml, mean +/- SE) and at day 5 (25.24 +/- 3.76), as compared with the level at day 1 (11.25 +/- 1.07). The CSF level gradually decreased and returned to the day 1 level at day 17. The serum PGDS level was much lower than the CSF level (0.39 +/- 0.06 at day 1) and almost unchanged until day 17. The neuron-specific enolase level in CSF, as an index of brain damage, was maximum at day 1 (29.83 +/- 7.32 ng/ml) and decreased at day 3 and at day 5 (18.28 +/- 2.65 and 11.95 +/- 1.82, respectively). These results suggest that the transient and delayed increase in the PGDS level in CSF is due to its induction of PGDS in the arachnoid membrane after SAH.
    Neuroscience Letters 09/1999; 270(3):188-90. · 2.11 Impact Factor
  • Article: Secretion of lipocalin-type prostaglandin D synthase (beta-trace) from human heart to plasma during coronary circulation.
    Advances in experimental medicine and biology 02/1999; 469:49-54. · 1.09 Impact Factor
  • Article: Expression of lipocalin-type prostaglandin D synthase (beta-trace) in human heart and its accumulation in the coronary circulation of angina patients.
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    ABSTRACT: Lipocalin-type prostaglandin D synthase (L-PGDS) is localized in the central nervous system and male genital organs of various mammals and is secreted as beta-trace into the closed compartment of these tissues separated from the systemic circulation. In this study, we found that the mRNA for the human enzyme was expressed most intensely in the heart among various tissues examined. In human autopsy specimens, the enzyme was localized immunocytochemically in myocardial cells, atrial endocardial cells, and a synthetic phenotype of smooth muscle cells in the arteriosclerotic intima, and accumulated in the atherosclerotic plaque of coronary arteries with severe stenosis. In patients with stable angina (75-99% stenosis), the plasma level of L-PGDS was significantly (P < 0.05) higher in the great cardiac vein (0.694 +/- 0.054 microg/ml, n = 7) than in the coronary artery (0.545 +/- 0.034 microg/ml), as determined by a sandwich enzyme immunoassay. However, the veno-arterial difference in the plasma L-PGDS concentration was not observed in normal subjects without stenosis. After a percutaneous transluminal coronary angioplasty was performed to compress the stenotic atherosclerotic plaques, the L-PGDS concentration in the cardiac vein decreased significantly (P < 0.05) to 0.610 +/- 0.051 microg/ml at 20 min and reached the arterial level within 1 h. These findings suggest that L-PGDS is present in both endocardium and myocardium of normal subjects and the stenotic site of patients with stable angina and is secreted into the coronary circulation.
    Proceedings of the National Academy of Sciences 12/1997; 94(26):14689-94. · 9.68 Impact Factor

Institutions

  • 2001
    • Dokkyo Medical University
      • Department of Cardiology & Pneumology
      Tochigi, Tochigi-ken, Japan
    • Tokyo University and Graduate School of Social Welfare
      Tokyo, Tokyo-to, Japan
  • 1999
    • Nagoya City University
      • Department of Neurosurgery
      Nagoya-shi, Aichi-ken, Japan