Chemistry: molecular biology and microbiology – Measuring or testing process involving enzymes or... – Involving cholesterol
Reexamination Certificate
1999-10-14
2001-02-27
Leary, Louise N. (Department: 1623)
Chemistry: molecular biology and microbiology
Measuring or testing process involving enzymes or...
Involving cholesterol
C435S019000, C435S025000, C435S027000, C435S028000
Reexamination Certificate
active
06194164
ABSTRACT:
TECHNICAL FIELD
The present invention relates to a method for quantifying cholesterol in low density lipoprotein (LDL, The cholesterol in low density lipoprotein will be hereinafter also referred to as “LDL cholesterol”. In the present specification, the term “cholesterol” includes both ester type cholesterol and free cholesterol), which is important for the diagnosis of arterial sclerosis.
BACKGROUND ART
LDL plays a main role in transportation of cholesterol in blood and most of the cholesterol deposited on the blood vessel wall in pultaceous arterial sclerosis is originated from LDL. Increase in the amount of LDL in plasma is one of the major risk factors in pultaceous sclerosis such as ischemic heart disease, so that separate quantification of LDL cholesterol is clinically important.
Conventional methods for quantifying LDL cholesterol include a method comprising two steps, that is, a fractionation operation and an operation for quantifying the cholesterol, and a method in which the blood levels of total cholesterol, HDL cholesterol and triglyceride are determined and the amount of the LDL cholesterol is determined according to the Friedewald's equation.
Fractionation operation includes ultracentrifugation method, precipitation method, immunochemical method and the like. In the ultracentrifugation method, LDL is separated exploiting the difference in the specific gravity by an ultracentrifuge, and the amount of the cholesterol therein is measured. In the precipitation method, anti-HDL antibody, polyanion and a divalent cation are added to form an insoluble precipitate, and the LDL cholesterol in the supernatant after centrifugation is quantified (WPI Acc No.85-116848/20). In the immunochemical method, anti-HDL antibody, anti-VLDL antibody and anti-CM antibody are bound to latex particles, and the latex particles are removed by centrifugation or by passing through a filter after agglutination, followed by quantifying the LDL cholesterol (WPI Acc No. 84-301275/49). However, these conventional methods are problematic in simplicity or cost.
According to the Friedewald's equation, the amount of LDL cholesterol is calculated by subtracting the amount of the HDL cholesterol from the amount of the total cholesterol, and then further subtracting the ⅕ of the amount of the triglyceride. However, since this method does not take the influence by the diet and the individual difference, this method is problematic in accuracy.
Recently, a method for quantification of LDL cholesterol, which does not require fractionation operation, has been reported (WPI Acc No. 83-766269/38). However, in this method, the specificity to LDL is not sufficient.
DISCLOSURE OF THE INVENTION
The object of the present invention is to provide a method for quantifying LDL cholesterol, by which LDL cholesterol is separately quantified simply without requiring complicated centrifuge operation.
The present inventors discovered that the amount of cholesterol in LDL can be quantified by erasing the cholesterol other than the cholesterol in the low density lipoprotein in the first step, and by measuring the remaining cholesterol in the subsequent second step, thereby completing the present invention.
That is, the present invention provides a method for quantifying cholesterol in low density lipoprotein in a test sample which may contain low density lipoprotein, high density lipoprotein, very low density lipoprotein and/or chylomicron, which method comprises a first step of erasing cholesterol in high density lipoprotein, very low density lipoprotein and chylomicron in a test sample, and a second step of quantifying cholesterol remaining in said test sample.
By the present invention, a method for quantifying LDL cholesterol, by which LDL cholesterol is separately quantified simply without requiring complicated centrifuge operation, was provided.
REFERENCES:
patent: 5807696 (1998-09-01), Miyauchi et al.
patent: 0676642 A1 (1995-10-01), None
patent: 0764848 A1 (1996-03-01), None
patent: 7501945 (1995-03-01), None
patent: 730136 (1995-11-01), None
patent: 9299 (1997-01-01), None
patent: WO 9628734 (1996-09-01), None
patent: WO 974553A1 (1997-12-01), None
Miki, Yutaka; Seibutsu Shiryo Buneski, vol. 21(5), pp. 379-384 (Abstract Only), 1998.
Fujiwara Akira
Ito Yasuki
Matsui Hiroshi
Mizuno Kazushige
Ohara Shuichi
Birch & Stewart Kolasch & Birch, LLP
Denka Seiken Co., Ltd.
Leary Louise N.
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