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Biomedical subjects

T T Ishikawa

Publications and source records attributed to T T Ishikawa.

12 recordsLinked to original sources
PubMed1977

Phytosterols and cholesterol in malignant and benign breast tumors.

Tissue phytosterol and cholesterol levels in 10 benign and 8 malignant breast tumors were quantitated to reexamine the hypothesis that malignant tumors had distinctive phytosterol content. Phytosterols were present in 9 of 10 benign and 7 of 8 malignant breast tumors. Mean (+/- S.E.) cholesterol, campesterol, stigmasterol, and beta-sitosterol in malignant and benign tumors (microgram/g wet weight) did not significantly differ (p greater than 0.1): (formula: see text) In the malignant tumors, tissue cholesterol correlated with campesterol (r = 0.97) and beta-sitosterol (r = 0.97) (p less than 0.01), but not stigmasterol (r = -0.06). In benign tumors, tissue cholesterol correlated with campesterol (r = 0.43), stigmasterol (r = 0.64), and beta-sitosterol (r = 0.94), with p less than 0.01 for the latter two. Phytosterols were present in four samples of normal breast tissue with mean (+/- S.E.) campesterol, stigmasterol, and beta-sitosterol (2 +/- 0.8, 15 +/- 9, 7 +/- 5 microgram/g wet weight) slightly but not significantly lower than in benign and malignant breast tumors, p greater than 0.1. The comparability of tissue phytosterols in benign and malignant breast tumors and in normal breast tissue appears to render unlikely and putative etiological relationship between phytosterols and breast carcinoma.

Adenofibroma↗
PubMed1976

A study of the heparin-manganese chloride method for determination of plasma alpha-lipoprotein cholesterol concentration.

To assess the limits of the heparin MnCl2 precipitation method for quantitation of alpha-lipoprotein cholesterol (C-HDL), effects of varying final McCl2 and heparin concentrations were studied, and the precipitation method was compared to preparative ultracentrifugation. In 65 parallel plasma aliquots, C-HDL (X+/-SE) determined by ultracentrifugation (54.3+/-1.8 mg/dl) correlated significantly (r=0.98, P less than 0.001) with the precipitation method (56.0+/-1.9 mg/dl). C-HDL by ultracentrifugal and precipitation methods were also similar in 16 subjects with triglycerides ranging from 150 to 312 mg/dl (41.4+/-2.6, 43.4+/-2.8, r=0.97, P less than .001). A constant amount of cholesterol in the supernatant was measured over a final McCl2 range of 0.046-0.23 M, and cholesterol values in the supernatant at final McCl2 concentrations of 0.046, 0.05, and 0.055 M did not differ from each other, P greater than 0.1. However, cholesterol levels in the supernatant at final MnCl2 concentration of 0.042 M differed from those at concentrations of 0.046, 0.05, and 0.055 M, P less than 0.05 and the amount of supernatant cholesterol increased as the final McCl2 concentration was reduced from 0.042 to 0.02 M. A constant amount of cholesterol in the supernatant was measured over a heparin concentration range of 92-734 USP units/ml. The final MnCl2 and heparin concentrations of 0.046 M and 184 USP units/ml, which are incorporated in widely used procedures, gave C-HDL values for the precipitation method which were in close agreement with the ultracentrifugal method. There is no evidence for a heparin-Mn++ precipitation of HDL and systematic underestimation of HDL by the precipitation method. However, the final MnCl2 concentration is very near the minimum required for accurate measurement of C-HDL. To preclude incomplete precipitation of low and very low density lipoproteins by insufficient manganese concentration, an increase of the manganese concentration should be considered.

Chemical Precipitation↗
PubMed1976

Direct quantitation of cholestanol in plasma by gas-liquid chromatography.

A gas-liquid chromatographic (GLC) method for quantitation of cholestanol in plasma was developed using SP-1000 without the need for argentation thin-layer chromatography and silylation. Cholestanol was resolved well before cholesterol and the phytosterols. This method was sensitive, specific for cholestanol, and reproducible.

Cholestanol↗
PubMed1976

Plasma and dietary phytosterols in children.

Plasma phytosterol (plant sterol) levels were studied in 26 infants on various commercial formulas, in 36 infants on breast or cow's milk formulas, in 101 normal and 22 hypercholesterolemic children on a free diet, and in 32 hypercholesterolemic children on a low-cholesterol diet. Commercial formulas, poor in animal fats and enriched with vegetable oils, and low-cholesterol, phytosterol-rich diets generally elevated total plasma phytosterol levels in infants and hypercholesterolemic children from normal mean levels of 2 mg/100 ml to about 9 mg/100 ml. The implications of long-term three- to five-fold elevations of the plasma phytosterols (campesterol, stigmasterol, beta-sitosterol) in infancy and childhood are unknown. Watchful prospective analysis of plasma phytosterol levels may be useful, particularly in regards to otherwise unanticipated long-term effects of cholesterol-poor, phytosterol rich diets.

Adolescent↗
PubMed1976

Phytosterols in aortic tissue in adults and infants.

Relationships between aortic tissue phytosterols and cholesterol in five adults, five infants, two neonates, and one 30 week abortus were studied. In the normal aortic tissue of the abortus and two neonates, tissue cholesterol levels were 0.67, 0.08, and 0.89 mg. per gram of wet weight, respectively; tissue phytosterol levels were as follows: compesterol (0.94, 0.62. 1.8), stigmasterol (0.18, 0.54, 0.80) and beta-sitosterol (0.78, 1.84, 2.80) mug per gram of wet weight. In 11 aortic tissue samples from five infants studied at 3, 4, 6, 6, and 36 months of age, all having been on phytosterol-rich formulas, mean aortic cholesterol was 0.66 mg. per gram, campesterol 3.57, stigmasterol 9.22, and beta-sitosterol 8.93 mug per gram. In the 11 aortic samples from five infants, mean (+/-S.E.) tissue stigmasterol (9.2+/-2.7) and beta-sitosterol ((8.9+/-1.3) were greater than mean levels (0.51+/-0.18 and 1.8+/-0.6) in the four aortic sections from the abortus and two neonates. Mean (+/-S.E.) cholesterol in the 11 aortic sections from five infants (0.66+/-0.11) was not significantly higher than cholesterol (0.55+/-0.24 mg. per gram) in the four aortic sections from the abortus and two neonates, but was considerably higher than the tissue cholesterol level of 0.08 mg. per gram in one of the two neonates. Mean (+/-S.E.) cholesterol in 11 normal aortic tissue sections from five adults (3.4+/-0.7 mg. per gram) was higher than in the five infants, whereas mean compesterol, stigmasterol, and beta sitosterol, respectively 14, 13, and 16 mug per gram, were somewhat higher but generally comparable to infant levels. In five aortic tissue samples from mature atheromatous plaques in two adults, cholesterol was 54 mg. per gram and mean campesterol, stigmasterol, and beta-sitosterol were, respectively, 112, 167, and 236 mug per gram. In 15 aortic tissue samples from five adults, cholesterol correlated closely with stigmasterol, r=0.865, beta-sitosterol, r=0.918, and with total phytosterols, r=0.938, p less than 0.01, but not with campesterol, r=0.448. In 11 aortic tissue samples from five infants, cholesterol did not correlate with campesterol, r=0.005, stigmasterol, r=0.006, beta-sitosterol, r=-0.099, or total phytosterols, r=-0.045. Prior to birth some phystosterols apparently cross the placenta. In the first several months of life, vegetable-oil formula-fed infants accrue plant sterols in their aortic tissues. Moderate amounts of phytosterols are present in mature atheromatous lesions in adults. The implications of these findings are unknown and their relationship to deposition of cholesterol in atheromatous and in normal aortic tissues remains to be elucidated.

Adult↗
PubMed1974

Analysis of alpha-lipoprotein cholesterol in 50 microl of plasma.

A micromethod for quantitation of alpha-lipoprotein cholesterol was devised for gas-liquid chromatography to minimize plasma sample size and facilitate lipid studies using capillary blood from children or small animals. alpha-Lipoprotein cholesterol was measured by gas-liquid chromatography in 20 micro l of the centrifuged supernate obtained after addition of 5 micro l of mixed heparin-manganese chloride solution 1:1 (v/v) to 50 micro l of plasma. Comparison of venous alpha-lipoprotein cholesterol measured by gas-liquid chromatography with venous alpha-lipoprotein cholesterol measured by conventional heparin-manganese precipitation and ferric chloride (colorimetric) cholesterol determination gave a correlation coefficient of 0.98 for 80 plasma samples. Capillary alpha-lipoprotein cholesterol and venous alpha-lipoprotein cholesterol were closely correlated in 31 patients (r = 0.97).

Adult↗
PubMed1974

Quantitative analysis of cholesterol in 5 to 20 microliter of plasma.

A gas-liquid chromatographic micromethod for quantitation of cholesterol in 20 micro l of plasma was developed using 5alpha-cholestane as an internal standard, saponification with tetramethylammonium hydroxide-isopropanol, and extraction with tetrachloroethylene-methyl butyrate. Cholesterol levels in plasma samples were calculated by comparing cholesterol-cholestane peak height ratios with those of preassayed reference plasma. Over a plasma cholesterol range of 44 to 468 mg/100 ml, the gas-liquid chromatographic micromethod and the automated ferric chloride colorimetric method gave nearly identical results (r = 0.99) in duplicate aliquots of 131 plasma samples.

Adult↗