| Project/Area Number |
18590519
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Laboratory medicine
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| Research Institution | Asahikawa Medical College |
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Principal Investigator |
ITOH Yoshihisa Asahikawa Medical College, Dept of Medicine, Professor (20129026)
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| Co-Investigator(Kenkyū-buntansha) |
YAMADA Toshiyuki Jichi Medical University, Dept, of Medicine, Associated Professor (50211636)
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| Project Period (FY) |
2006 – 2007
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| Project Status |
Completed (Fiscal Year 2007)
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| Budget Amount *help |
¥2,730,000 (Direct Cost: ¥2,400,000、Indirect Cost: ¥330,000)
Fiscal Year 2007: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
Fiscal Year 2006: ¥1,300,000 (Direct Cost: ¥1,300,000)
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| Keywords | Urine / Stability / Protease / β2-microglobulin / α1-microglobulin / Pepsin / Protein 1 / Immunounreactive albumin / シスタチンC / 尿中安定性 / 非特異的吸着 / 疎水性 / 親水性 / 修飾アルブミン / α-1ミクログロブリン / 不安定性 |
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| Research Abstract |
Proteins and peptides in urine are structurally and immunochemically heterogeneous, which are caused by proteases under different pathophysiologic conditions. The measured value of given proteins can be overestimated or underestimated by the effect. Under the quality assurance system we have investigated mechanisms of modification or degradation. Thus sorting specific and sensitive urine markers for clinical use.
1. Urine protein degradation: Using beta2-microglobulin and IgG we re-evaluated the mechanism by western blots and analyses of cleavage sites on the primary structure. It has proved that not only cathepsin D, but pepsin and gastricin are involved in the digestion.
2. Heterogeneity and degradation of alpha-1-microglobulin in urine: The discrepancy of value has been noted between immunoassay systems. Supplying reference material it proved to be systemic error, being due to different assigned value. Use of a cofactor gave solutions. Reference material should be in a lyophilized form.
3. Urine cystatin C: a) There are at least six cleavage sites on the primary structure by acid proteases that explain for instability in acidified urine. B) Non-specific adsorption of the protein has little effects on underestimation of measured value. C) Serum reference value was set, that will be basis of that for urinary proteins.
4. Immunounreactive albumin: The existence in urine is not restricted to diabetic nephropathy, but common to renal tubular dysfunction.
5. Proteins in urinary sediments: Localization of various proteins were demonstrated immunohistochemically. Among others amyloid-beta protein was positive in granular casts. Further Pathophysiologic and biochemical studies are needed.
6. Protein 1 (P1): P1 in urine was found to be decreased in pneumoconiosis. Stability of P1 in urine assures clinical significance since the cleavage site is only one on the molecule.
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