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Previous studies have indicated that consumption of boiled coffee raises total and low density lipoprotein (LDL) cholesterol, whereas drip-filtered coffee does not. We have tested the effect on serum lipids of consumed coffee that was first boiled and then filtered through commercial paper coffee filters. Sixty-four healthy volunteers consumed six cups per day of this boiled and filtered coffee for 17 days. Then, they were randomly divided into three groups, which, for the next 79 days, received either unfiltered boiled coffee (lipid content, 1.0 g/l), boiled and filtered coffee (0.02 g lipid/l), or no coffee. Serum total cholesterol levels rose by 0.42 mmol/l (16 mg/dl; 95% confidence interval [CI], 0.14-0.71), LDL cholesterol levels by 0.41 mmol/l (16 mg/dl; 95% CI, 0.16-0.66), and apolipoprotein B levels by 8.6 mg/dl (95% CI, 3.8-13.4) in those who consumed boiled coffee relative to those who consumed boiled and filtered coffee. Responses of triglycerides, high density lipoprotein cholesterol, and apolipoprotein A-I did not differ significantly among these groups. No significant effects on serum lipid levels were found in the boiled and filtered coffee-consuming group compared with those who drank no coffee. In subjects who drank boiled coffee, serum campesterol level, an indicator of cholesterol absorption, remained constant. The serum lathosterol level, an indicator of cholesterol synthesis, increased by 11% (p less than 0.05), but the lathosterol to cholesterol ratio did not change. We propose that paper filters of the type used for drip-filtered coffee retain the lipid present in boiled coffee and in that way remove the hypercholesterolemic factor.(ABSTRACT TRUNCATED AT 250 WORDS)

We have described the protein, enzyme, and isoenzyme characteristics of three gross fractions of both normal and abnormal human sera, as obtained by application of high centrifugal force. In the absence of solution gradient, such fractions represent pure and undiluted elements of the serum; they are reproducible and sufficiently voluminous for extensive analytical study. Specific features of these fractions may be of interest in planning additional or peripheral investigations of serum. Fraction I appears to be a fair sample of native serum water; Fraction II appears to segregate the pre-β-globulin lipoprotein component observed in some sera; Fraction III is a concentrated solution of LDH, CPK, and SGOT enzymes, and γ-globulin-rich protein, which is hpoprotein-free. More than 95% of the LDH, CPK, and SGOT is located in Fractions II and III. Quantitative activity and qualitative nature of these enzymes appears to survive the stress of the ultracentrifuge technique relatively well.

Heparin precipitates of human and rat serum lipoproteins, dissolved, dialyzed, and analyzed by paper electrophoresis, were found to migrate as β-lipoproteins. The pre-β-lipoproteins disappeared. Using specific anti-human β- and α-lipoprotein sera it was shown that the heparin precipitate of human very low density lipoproteins (VLDL) contained β-lipoproteins, whereas the supernatant contained α-lipoproteins. This indicates that these components are dissociated by the heparin precipitation procedure. Following partial delipidation of the heparin precipitate, a procedure which exposes the antigenic site of the α-lipoprotein of the VLDL, it can be demonstrated that the α-lipoprotein component is completely removed by the heparin precipitation procedure. Partially delipidated rat VLDL showed four immuno-reactive components when reacted against rabbit anti-rat VLDL serum, but only one, corresponding to the β-lipoprotein, when reacted with rabbit antiserum to heparin precipitate.Chemical analysis of the lipid components of the heparin precipitate and supernatant of human and rat VLDL reveals that over 90% of the triglycerides are precipitated by the heparin and that the supernatant fraction contains lipoproteins having a phospholipid to protein ratio higher than any of the other lipoproteins.Upon reincubation of the dissolved and dialyzed human serum heparin precipitate and its supernatant a pre-β band reappeared on paper electrophoresis. The recombined pre-β-lipoprotein was isolated and found to react with anti-β-, but not with anti-α-lipoprotein serum. This is a characteristic of native pre-β-lipoproteins. Evidence has also been obtained that the high density lipoproteins combine only with the β-lipoproteins originally present in the VLDL.

Serum α1-antitrypsin, α1-acid glycoprotein, baptoglobin, ceruloplasmin and C-reactive protein are increased, albumin, transferrin, α1-and β-lipoprotein are decreased as an early response to tissue trauma and inflammatory disease. In infection these changes are followed by a rise of γ-globulins.

A method for lipoprotein electrophoresis on cellulose acetate is described. Features which distinguish this method are: (1) It affords complete resolution of chylomicrons, β-lipoproteins, pre-β-lipoproteins, and α-lipoproteins into distinct bands and allows the relative magnitude of each to be estimated by transmission microden-sitometry. (2) Lipoproteins can be eluted quantitatively from separated bands for analyses. (3) Intact chylomicrons can be recovered by ultrasonic treatment. (4) The procedure is rapid, reproducible, and does not require addition of albumin to the buffer.

1. (1) The solubility of purified low density lipoprotein in the presence of various concentrations of a clinical dextran preparation (mean mol. wt. 71400) has been investigated at physiological pH and ionic strength. 2. (2) Dextran concentrations above 7% (w/v) caused precipitation of low density lipoprotein from a solution containing 1.1% (w/v) of the protein. 3. (3) The results have been explained in terms of an activity increment of low density lipoprotein due to steric exclusion by dextran. 4. (4) The activity increment caused by 1% dextran has been calculated and is approximately 50%.