Herbert K. Naito

Effect of alfalfa meal on shrinkage (regression) of atherosclerotic plaques during cholesterol feeding in monkeys

A semipurified diet containing 1.2 mg of cholesterol/Cal was fed to cynomolgus monkeys (Macaca fascicularis). At the end of 6 months, a group of 18 animals was killed for evaluation of atherosclerosis in the aorta and the coronary arteries. The remaining monkeys were assigned to three groups of 18 animals each and fed, during the following 18 months, semipurified diets containing 0.34 mg of cholesterol/Cal with or without alfalfa meal, or a diet consisting entirely of Monkey Chow. a decrease in cholesterolemia and plasma phospholipid levels, normalization in the distribution of plasma lipoproteins, and reduction in the extent of aortic and coronary atherosclerosis were observed in monkeys fed the semipurified diet containing alfalfa, although the intake of cholesterol remained as high as in the usual American diet. These changes, also observed in monkeys fed a chow diet almost devoid of cholesterol, suggest that alfalfa counteracts the atherogenic effect of dietary cholesterol.

The Association of Serum Lipids, Lipoproteins, and Apolipoproteins with Coronary Artery Disease Assessed by Coronary Arteriography

There is little doubt that serum lipids and lipoproteins are intimately involved in atherogenesis. Epidemiological, clinical, and animal experimental research have clearly demonstrated a positive association between serum total cholesterol (TC) concentrations and coronary artery disease (CAD). However, measurements of lipoprotein lipids and lipoprotein proteins (apoproteins) appear to enhance the assessment of CAD risk. For example, the measurements of low-density lipoprotein (LDL) as LDL-Cholesterol and high-density lipoprotein (HDL) as HDL-Cholesterol show a better statistical correlation with coronary atherosclerosis than either T C or triglycerides (TG) alone.’4 Furthermore, expression of the lipoprotein lipids as ratios (i.e., LDL-C/TC, HDL-C/TC, or LDLC/HDL-C) appears to increase the statistical relationship with the severity and extent of CAD even no re.^.^ Recent studies on serum total apoprotein and lipoprotein protein measurements are beginning to suggest that, they too, are sensitive markers for the assessment of CAD and even for peripheral vascular disease.” Finally, partitioning the major lipoprotein classes into LDL, and LDL,, or HDLz and HDL,, increases their sensitivity, specificity, and hence, their predictive To answer some of these questions, we did a double-blind study whereby we simultaneously examined the relationship of serum lipids (TC and TG), lipoprotein lipids (HDL-phospholipid, HDL-cholesterol, HDL-triglycerides), and lipoprotein proteins (HDL-apo A) with the severity of coronary atherosclerosis. Part of this data has already been published The HDL subfraction data and apolipoprotein data are new.

Measurement of total HDL, HDL2 and HDL3 by dextran sulfate—MgCl2 precipitation technique in human serum

We describe a simple and reliable method for determination of total HDL, HDL2, and HDL3 by a precipitation technique using dextran-sulfate (Mr 50,000)-Mg2+. A combined solution of dextran sulfate and Mg2+ at their respective final concentration of 0.9 g/l and 27 mmol/l was optimal for separating total HDL from the other lipoproteins. The present method compares favorably with a heparin-MnCl method (r = 0.998). The HDL was further resolved into HDL2 and HDL3 by addition of a combined solution of dextran sulfate and Mg2+ (1.5 m/l and 10 g/l) to the total HDL solution. Comparison of this precipitation method with the well-established ultracentrifugation method yielded the mean correlation coefficient of 0.941 and 0.869 for HDL2 and HDL3, respectively.

Unusual Serum Lipoprotein Abnormality Induced by the Vehicle of Miconazole

Miconazole, a phenethylimidazole,1 is effective in vitro against several pathogenic fungi,1 , 2 and has cured systemic mycoses in man.3 , 5 In contrast to amphotericin B, miconazole does not appear...

Treatment of established atherosclerosis during cholesterol feeding in monkeys

A semipurified diet containing 43% of the calories as fat and 1.2 mg of cholesterol/cal was fed to cynomolgus monkeys (Macaca fascicularis) for 6 months; the cholesterol content was reduced to 0.34 mg/cal for the next 18 months. During the latter period, the monkeys were assigned to 4 groups of 18 animals each and received the following dietary additions: A, none (controls); B, cholestyramine (5%, w/w); C, dextrothyroxine (0.003%); and D, Wy-14,643 (0.45%). Cholestyramine normalized plasma lipid levels and reduced the size of aortic and coronary atherosclerotic lesions in spite of the high-fat, high-cholesterol intake. Dextrothyroxine reduced cholesterolemia but did not modify the extent of arterial lesions. Wy-14,643 changed neither plasma cholesterol levels nor the extent of atherosclerosis.

Determination of urinary thiamine by high-pressure liquid chromatography utilizing the thiochrome fluorescent method

A sensitive, reproducible, and specific method for the determination of urinary thiamine has been established. Unique to the use of high-pressure liquid chromatography (HPLC) to separate the fluorescent thiamine derivative from interfering fluorescent compounds. Urine samples were passed through a Decalso catoin-exchange column, washed with 0.5 M KCl to remove some interfering compounds, and eluted with 3.4 M KCl. The eluted thiamine was converted to the fluorescent derivative, thiochrome, by reaction with alkaline potassium ferricyanide. The reaction mixture was extracted with isobutanol and subjected to HPLC monitored by a fluorescent detector. Within-day and day-to-day coefficients of variation proved to be 2.5% and 1.2% respectively. Recovery of added thiamine (range 0.04 to 2.0 microgram/ml) averaged 99.9 +/- 5.3%. The sensitivity of this method was 0.03 microgram/ml.

Dyslipoproteinemia (a remnant lipoprotein disease) in uremic patients on hemodialysis.

Abstract Plasma lipoproteins of uremie patients on hemodialysis were studied by chemical, electrophoretic, ultracentrifugal and electron microscopic techniques. Low-density lipoproteins ( d 1.006–1.063) isolated from the plasma of five patients who were on hemodialysis therapy for 1 to 54 months showed two or three midband lipoproteins (bands between pre-β and (β-lipoproteins) when studied by polyacrylamide gel electrophoresis. Correspondingly, two or three peaks were observed in the analytical ultracentrifugal patterns of the isolated low-density lipoproteins of these patients. Low-density lipoproteins of a plasma which showed three midband lipoprotein components on polyacrylamide gel electrophoresis and three peaks by analytical ultracentrifugal analysis were isolated and each midband lipoprotein subfraction was characterized. As demonstrated with the isolated lipoprotein subfractions, low-density lipoproteins of the patient consisted of Sf 13, Sf 10, and Sf 7 + Sf 6 low-density lipoproteins. The lipoproteins with the higher Sf rate (Sf 13) contained more triglyceride and less cholesteryl ester and showed a larger lipoprotein particle size than the other low-density lipoprotein subfractions, which properties are characteristics of the intermediate-density, remnant lipoproteins. These findings indicate that the previously-reported “broad-midband lipoprotein pattern” on polyacrylamide gel electrophoresis which was detected in 58% of hemodialysis patients is a result of the accumulation of the remnant or intermediatedensity lipoproteins.

Familial hyperlipoproteinemia in beagles.

Abstract Canine serum lipoproteins (Lp) were studied by electrophoretic and immunologic techniques. Two of five normal beagles on a regular diet were spontaneously “hyperlipidemic”. Using the double-layer separating gel, polyacrylamide gel (PAG) block electrophoresis method, α 1 -, α 2 -, and β-Lps were consistently detected. While α 1 -Lp was the major serum Lp in normolipidemic dogs, α 2 - and β-Lps were elevated in the “hyperlipidemic” animals. The α 1 -Lp and α 2 -Lp exhibited A 1 and A 2 antigenic components and β-Lp had B and C components. We propose that in all probability α 1 - and α 2 -Lp have similar A 1 , A 2 components, but that β-Lp contains both B and C components. This suggests that α 1 - and α 2 -Lps, particularly in beagles with familial hyperlipoproteinemia are distinct Lp entities with similar lipid composition and with two common major antigenic components. The albumin fraction of PAG block electrophoretograms contained lipid materials other than free fatty acids. This albumin-lipid complex may be similar to that observed in guinea pig serum. On the basis of this study, the α 2 -Lp of dogs is a distinct and important Lp moiety which is elevated in the early stages of both familial and experimental canine hyperlipoproteinemia.

Stimulation of hepatic cholesterol 7α-hydroxylase activity by administration of an estrogen (17β-estradiol-3-benzoate) to female rats

Abstract Adult female rats were given daily subcutaneous injections of 17β-estradiol-3-benzoate, 25 μg/day for twenty days. Rats were then killed under four different experimental conditions; (1) Fasting, killed in the morning (FM), (2) Non-fasting, killed in the morning (NFM), (3) Fasting, killed at night (FN), and (4) Non-fasting, killed at night (NFN). Estradiol induced a three-fold increase in hepatic cholesterol 7α-hydroxylase activity in group FM and a significant increase in group NFN. Although increases in 7α-hydroxylase activity might be associated with lower serum cholesterol levels (by increasing the rate of conversion of cholesterol to bile acids), serum cholesterol concentrations were, in fact, elevated in all rats given estradiol.

Interaction of thyroxine, energy metabolism and swimming performance of rats.

Abstract Time required for exhaustive swimming by young-mature rats weighted with lead weights (4% of body weight) was found to decline over a ten week experimental period. While a positive relationship existed between thyroid status and swimming time, a concomitant decrease in swimming time occurred in each of the respective five groups of rats: control (C) rats with intact thyroids, athyroid (A-Tdx), hypothyroid (Hypo-Tdx), euthyroid (Eu-Tdx), and hyperthyroid (Hyper-Tdx) rats between day 70–140. The latter three groups were thyroidectomized (Tdx) and given daily replacement therapy of L-thyroxine (L-T 4 ) during the experimental period. Epididymal fat pads were found to be almost non-existent in the A-Tdx rats. Serum triglycerides of A-Tdx, Eu-Tdx, and Hypo-Tdx animals were significantly lower than in C. Daily food intakes were also lower in the A-Tdx and Hypo-Tdx groups than in C and Hyper-Tdx groups. Thyroxine insufficiency, the decreasing feed intake, and particularly the ability to carry the increasing absolute weight load during exercise are factors that may be important in explaining the observed decline in work capacity during the ten week experimental period.