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Biomedical subjects

J W Erdman

Publications and source records attributed to J W Erdman.

At least 73 records · Page 4Linked to original sources
PubMed1992

Beta-carotene uptake and tissue distribution in ferrets (Mustela putorius furo).

Ferrets accumulate beta-carotene in liver and adipose tissue after chronic feeding. This study was designed to further evaluate the time course of uptake and depletion of beta-carotene in ferret serum and tissues. Male ferrets (n = 15; 1000-1200 g) were given a single dose of beta-carotene (10 mg/kg body wt) with a meal. Animals were killed at various time points over an 11-d period. Blood and tissue samples were extracted and analyzed for beta-carotene by HPLC. Peak serum beta-carotene levels (0.68 +/- 0.18 mumol/L) were observed 8 h after the test meal. beta-Carotene was essentially cleared from the blood by 76 h. Peak beta-carotene concentrations (nmol/g) were observed between 8 and 16 h after ingestion for liver (1.20 +/- 0.04), lung (0.042 +/- 0.012), kidney (0.090 +/- 0.015) and spleen (0.076 +/- 0.012). Ferret liver also seemed to contain a variety of other polar and nonpolar carotenoids. Ferrets were shown to absorb beta-carotene from a meal and have a consistent serum response pattern. Absorbed beta-carotene is differentially distributed in a variety of tissues. The ferret seems to be a useful model for the study of beta-carotene absorption and metabolism.

Administration, Oral↗
PubMed1992

Bone composition and histology of young growing rats fed diets of varied calcium bioavailability: spinach, nonfat dry milk, or calcium carbonate added to casein.

Bone composition and histology were evaluated in young growing rats fed nutritionally complete but calcium-restricted (0.15%) diets in which calcium was derived from spinach, nonfat dry milk (NFDM), or CaCO3 added to casein. Groups of male weanling rats were pair-fed for 28 d. A 0.5% calcium casein-based diet group fed ad libitum was included to provide a comparison of normal bone structure and composition. Bone growth and bone ash were depressed in spinach-fed rats. Total bone tibia calcium in 0.5% calcium casein-based, 0.15% calcium casein-based, NFDM and spinach diet groups were 64.0, 29.2, 30.7 and 13.8 mg, respectively. All other measured bone mineral levels were also lower, except for potassium. Femur hydroxyproline concentrations were 1.2, 1.6, 1.6 and 2.1% in 0.5% calcium casein-based, 0.15% calcium caseinbased, NFDM and spinach diet groups, respectively. Bone histomorphometry indicated gross underdevelopment and compromised mineralization of trabecular bone of spinach-fed rats. For the first time, it has been demonstrated with histologic techniques that calcium from the low bioavailable source, spinach, compromises both the quantity and quality of bone. In contrast, when calcium is fed to growing animals at levels below the National Research Council requirement but from a highly bioavailable source (i.e., NFDM and CaCO3), there is only a reduction in bone quantity.

Animals↗
PubMed1992

Reduction of phytic acid in soybean products improves zinc bioavailability in rats.

The inhibitory effect of phytic acid in soybean products on zinc bioavailability was evaluated in two experiments in rats. In Experiment 1, soybean flours containing different natural phytic acid levels produced by sand culture techniques that limited phosphorus during growth of the soybean plants were formulated into diets. The rats fed a higher phytic acid level diet had lower food intake, depressed weight gain, and lower tibia zinc gain (P < 0.05). A negative, linear relationship between tibia zinc gain and dietary phytic acid level was found. In Experiment 2, two commercially produced soybean isolates containing either normal phytic acid level or a reduced level were formulated into diets. Slope ratio analysis revealed that relative zinc bioavailability from phytic acid-containing soybean isolate-based diets was significantly reduced (P < 0.05) compared with control diets. Reduced phytic acid soybean isolate-containing diets resulted in a significant increase of zinc bioavailability compared with normal phytic acid diets (P < 0.01). These results coupled with other reports indicate that phytic acid is the primary inhibitory factor in soybean products that results in reduced zinc bioavailability and that phytate reduction in soybean protein increases zinc bioavailability.

Animals↗
PubMed1992

Evaluation of the preruminant calf as a model for the study of human carotenoid metabolism.

This study evaluated the preruminant calf as an animal model for the study of human carotenoid metabolism. Fifteen newborn male Holstein calves were fed a carotenoid-free milk replacer diet to maintain them in the preruminant state. After a 7-d adjustment period, three calves were killed and 12 calves received a single oral dose (20 mg) of beta-carotene in the form of water-soluble beadlets. Blood samples were collected periodically and samples of various tissues were collected when the calves were killed. Three animals each were killed by exsanguination at 1, 3, 6 and 11 d post-dosing. Serum beta-carotene concentrations peaked between 12 and 30 h post-dosing and declined slowly afterwards. Serum data were fitted to a two-compartment model and yielded an elimination constant (k2) that was similar to reported human values. Adrenal tissue showed significant concentrations of beta-carotene by 24 h post-dosing, and levels were still elevated at 264 h. Liver, spleen and lung beta-carotene concentrations were significantly elevated by 24 h and rapidly declined thereafter. Adipose and kidney peak beta-carotene concentrations were observed at 72 and 144 h, respectively. Heart and muscle did not display significant changes in beta-carotene concentrations. The preruminant calf shows promise as an animal model for the study of absorption and metabolism of carotenoids by humans.

Adipose Tissue↗
PubMed1992

Effects of ethanol and carbon tetrachloride upon vitamin A status of rats.

The effects of ethanol and carbon tetrachloride (CCl4) upon tissue vitamin A, liver lipids, liver cytochrome P450 and hepatic morphology were investigated. It was anticipated that CCl4 treatment would have more severe effects upon vitamin A status because CCl4 provides greater hepatic injury than does ethanol. After a 2-week standardization feeding period, young male rats were divided into four groups. For 5 weeks one group of rats (n = 17) received ethanol in liquid diets (30% of calories) while another (n = 8) was exposed to CCl4 inhalation twice a week along with phenobarbital in the diet. All groups received the National Regulatory Commission recommended level for vitamin A. Comparison of ethanol and its pair-fed control group (n = 17) revealed: decreased hepatic vitamin A, no change in serum vitamin A, increased percentage of liver lipid, and cytochrome P450 with moderate fat accumulation in hepatocytes. Comparison of the CCl4-phenobarbital group with pair-fed controls (n = 8) showed: increased serum vitamin A, decreased hepatic vitamin A, increased cytochrome P450, marked hepatic fat accumulation, hepatic cell necrosis, and early cirrhosis. Thus, CCl4 (with phenobarbitol), which is a more potent hepatotoxin as evidenced by a more elevated cytochrome P450 and distorted liver morphology, not only reduced liver vitamin A, but also increased serum vitamin A. The extent of substrate and/or organ specificity remains to be elucidated.

Alcoholism↗
PubMed1991

Concentrations of selected carotenoids and vitamin A in human liver, kidney and lung tissue.

Concentrations of preformed vitamin A and five individual carotenoids (alpha-carotene, beta-carotene, cryptoxanthin, lutein and lycopene) were determined in liver, kidney and lung tissue from 20 autopsies of subjects ranging in age from 4 mo to 86 y. Total carotenoid concentrations in liver tissue were always greater than in kidney or lung tissue within the same patient. Total carotenoid concentration in adult subjects was 2.5-77.1 nmol/g tissue (mean 21.0 nmol/g tissue) in liver tissue (n = 14), 0.2-12.7 nmol/g tissue (mean 3.1 nmol/g tissue) in kidney tissue (n = 13) and 0.1-8.4 nmol/g tissue (mean 1.9 nmol/g tissue) in lung tissue (n = 13). Carotenoid content in tissue samples from two infants was low, ranging from 0 to 1.0 nmol/g tissue. beta-Carotene and lycopene were almost always the predominant carotenoids found in liver, kidney and lung tissue. beta-Carotene was positively correlated (P less than 0.05) with alpha-carotene, lycopene and total carotenoids in all of the tissues examined. In addition, beta-carotene and total carotenoids from liver tissue were positively correlated with the same carotenoids in both kidney and lung tissue within each patient. Total vitamin A (free plus esterified) concentration was 8.7-1102.2 nmol/g tissue in liver (n = 17), 3.5-343.9 nmol/g tissue in kidney (n = 14) and 0.7-404.6 nmol/g tissue in lung (n = 14). Vitamin A concentrations were significantly correlated with both beta-carotene and total provitamin A carotenoid concentrations in liver tissue, but not in kidney or lung tissue.

Adult↗
PubMed1990

The nutritional properties of extruded and non-extruded corn fiber isolate.

The feed efficiency and selected organ weights of rats fed diets containing 3 or 7% corn fiber, extruded corn fiber or silica were compared to rats fed a fiber-free diet. No significant differences were found in feed efficiency, spleen, lung or liver weights for any of the treatments relative to the fiber-free control diet.

Animal Feed↗
PubMed1990

The quality of microparticulated protein.

The purpose of this paper is to describe the effects of microparticulation upon the quality of microparticulated protein products and to confirm that microparticulation does not result in changes in protein structure or quality different from those that occur with cooking. Two products were tested: microparticulated egg white and skim milk proteins and microparticulated whey protein concentrate. Three approaches were used to monitor for changes in amino acid and protein value: amino acid analysis, protein efficiency ratio (PER) bioassay, and both one- and two-dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis. Evaluation of the results of these tests indicates that no significant differences were found when comparing the premix before and after microparticulation. Significant differences also did not occur when the premix was cooked using conventional methods. Collectively, the data provide strong evidence that the protein microparticulation process used to prepare microparticulated protein products (e.g., Simplesse) does not alter the quality or nutritional value of protein in the final products.

Egg Proteins↗
PubMed1990

Iron retention by rats from casein-legume test meals: effect of tannin level and previous diet.

The effect of tannin content on iron (Fe) bioavailability from several legumes was evaluated. Absorption of Fe from a casein (C), isolated soy protein (ISP), chickpea (CP) or red kidney bean (RKB) test meal was tested in marginally Fe-deficient rats [9.9 +/- 0.2 g Hb/100 mL (mean +/- SD)] using the extrinsic tag technique. Also, the effects of a casein habitual diet or of one of three casein-legume habitual diets fed before and after the test meal were investigated. Weanling male rats were fed the habitual diets containing 23 +/- 4 mg Fe/kg of diet (range 17-28) for 13 d. On d 14, after an overnight fast, rats were fed the test meal (1.5 g + 0.1 microCi 59Fe), and whole-body radioactivity was determined. The same habitual diet was refed for seven additional days, and whole-body radioactivity was determined again. Rats retained more iron from C (86%) than from ISP, CP or RKB test meals (73%, 75% and 67%, respectively) when the respective casein-legume habitual diets were fed before and after the test meals. With the casein habitual diet, there was no difference in retained iron from C, ISP, CP or RKB test meals (86%, 87%, 83% and 82%, respectively). Retention of iron from an RKB test meal was increased from 69.6 to 73% when about 90% of the extractable tannins were removed, but the difference was not statistically significant. Thus, feeding a casein-legume diet but not a casein diet prior to a test meal apparently predisposes the rat to lower iron absorption. However, in these studies, tannins per se did not significantly depress iron bioavailability.

Absorption↗
PubMed1990

Hydrated sodium calcium aluminosilicate: effects on zinc, manganese, vitamin A, and riboflavin utilization.

Three experiments were conducted to evaluate effects of hydrated sodium calcium aluminosilicate (HSCAS, a phyllosilicate) on Zn, Mn, vitamin A, and riboflavin utilization in young broiler chicks. In Experiment 1, addition of either .5% or 1.0% HSCAS to practical corn-soybean meal diets had no effect (P greater than .05) on total tibia Mn content or total liver vitamin A concentration. Total tibia Zn decreased slightly, but linearly (P less than .05), as level of HSCAS increased. Graded increments of riboflavin (0, .6 and 1.2 mg per kg of diet) were added to a riboflavin-free purified amino acid diet to assess riboflavin utilization as affected by HSCAS in Experiments 2 (.5% HSCAS) and 3 (1.0% HSCAS). Linear growth responses to riboflavin were obtained in the absence and presence of HSCAS. Common intercept multiple-linear regression indicated that riboflavin utilization was not affected (P greater than .05) by .5% or 1.0% HSCAS. The results suggest that .5% or 1.0% dietary HSCAS does not impair Mn, vitamin A, or riboflavin utilization, but that Zn utilization is reduced slightly as a result of HSCAS ingestion.

Aluminum Silicates↗
PubMed1990

Use of the modified relative dose response (MRDR) assay in rats and its application to humans for the measurement of vitamin A status.

After an appropriate dose of 3,4-didehydroretinol (vitamin A2, DR) is given orally in corn oil to retinol (R)-depleted rats, the ratio of plasma DR/R values at 3.5 h is inversely related to the liver concentration of vitamin A (Tanumihardjo & Olson, 1988). In the present study, a similar procedure, termed the modified relative dose response (MRDR) assay, was employed with rats containing a much broader range of liver reserves; ie, less than 2 to 107 nmol of vitamin A per g wet weight of liver (less than 1 to 30 micrograms/g). The DR/R ratio for 15 of 16 rats with liver reserves less than 17 nmol/g (less than 5 micrograms/g) was greater than 0.15, whereas the ratio was less than 0.15 for 7 of 8 rats with liver reserves greater than 17 nmol/g. This distribution provides sensitivity, specificity and positive predictive values of 94, 88 and 94 per cent, respectively. The DR/R ratios reached a maximal plateau in two other groups of rats between 3.5 and 8 h. At all times up to 24 h, mean DR/R ratios for vitamin A-depleted rats (45 +/- 6 nmoles of vitamin A/g liver) were approximately twice those for vitamin A-sufficient rats (230 +/- 40 nmoles of vitamin A/g liver). In three well-nourished adults, presumably with liver reserves of greater than 300 nmol/g wet weight liver (greater than 80 micrograms retinol equivalents/g), and in two young (1- and 3-years old) well-nourished children, maximal DR/R ratios were less than 0.023. In these cases, peak DR/R ratios were observed, with one possible exception, between 8 and 12 h.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1989

High-performance liquid chromatography and capillary supercritical-fluid chromatography separation of vegetable carotenoids and carotenoid isomers.

Carotenoids from carrots and tomatoes were separated with high-performance liquid chromatography (HPLC) and capillary supercritical fluid chromatography (SFC). All trans alpha- and beta-carotene were separated from their respective cis-isomers with capillary SFC. Carotenoids extracted from tomatoes included xanthophyll, lycopene and beta-carotene, while alpha- and beta-carotene were extracted from carrots. The HPLC separations were accomplished isocratically with a 25-cm column containing 5-microns ODS and methanol-acetonitrile-chloroform (47:47:6) or acetonitrile-dichloromethane (80:20). beta-Carotene cis-isomers were separated with SFC with a SB-cyanopropyl-25-polymethylsiloxane column, while alpha-carotene isomers were separated with two SB-cyanopropyl-50-polymethylsiloxane columns. Carotenoids from carrots and tomatoes were separated with a SB-phenyl-50-polymethylsiloxane column. Carbon dioxide with 1% ethanol was the SFC mobile phase. The eluent was monitored at 461 nm for HPLC and either 453 or 461 nm for SFC.

Carotenoids↗
PubMed1989

Soy products and the human diet.

This review focuses upon the nutritional significance of soy products in the human diet. The impact of the consumption of soy foods on a range of diet and health issues are discussed, including protein quality and growth promoting effects of soy protein, allergies in children, hypocholesterolemic effects of soy protein and soy fiber, effects of soy products upon glucose tolerance, and the bioavailability of zinc and iron from soy foods. Recent research reports involving humans and relevant animal studies are reviewed.

Animals↗
PubMed1988

Reversed phase HPLC analysis of alpha- and beta-carotene from selected raw and cooked vegetables.

Traditional AOAC colorimetric procedures for carotenoid analysis are known to lack specificity and accuracy. Newer HPLC methods provide the investigator with a more precise tool for carotenoid quantification in foods and tissues. In the present studies, reverse phase HPLC was utilized to evaluate the alpha- and beta-carotene content in raw and cooked leaves of lettuce, spinach and winged bean as well as in the carrot root. The vegetables were boiled or steamed and the true retention of alpha- and beta-carotene in the cooked products was determined. Boiling for 30 minutes resulted in a 53 and 40% loss of beta-carotene from lettuce and carrots, respectively. Full retention or even an increase in beta-carotene content in boiled winged bean leaves and spinach was noted. Steaming resulted in very good retention of alpha- and beta-carotene in all vegetables (83-139% retention). Thus, although cooking procedures (especially boiling) may result in oxidative loss of carotenoids in some vegetables, heat treatment increases the chemical extractability of alpha- and beta-carotene in others. The presence of carotenoproteins in some vegetables may affect the heat stability of extractability of alpha- and beta-carotene.

Carotenoids↗
PubMed1988

Ultrasonic propagation properties (@ 100 MHz) in excessively fatty rat liver.

The effects on the ultrasonic propagation properties of livers of the addition of 1% orotic acid to rat diets were examined. In rats, dietary orotic acid exerts several effects on lipid metabolism; its overall consequence is that excessively high hepatic fat concentrations are built up over a short period of time, thus making this an ideal model to study the ultrasonic propagation properties as a function of sequential development of fatty liver. Over a 16-day period on the orotic acid diet, the supplemented rat liver lipid concentrations increased from a normal range of 2%-4% to the lower 20's%; hepatic water concentration decreased from a normal value of approximately 70% to approximately 50%; total protein concentration decreased slightly from a normal range of 17%-20% to 11%-16%; and rat liver weight increased from approximately 11 g to around 20 g. Ultrasonic attenuation coefficient and speed were assessed in liver tissue with the scanning laser acoustic microscope at 100 MHz. As hepatic lipid increased, ultrasonic attenuation at 100 MHz increased temporally from a normal range of 12-14 dB/mm to a maximum of 54 dB/mm and ultrasonic speed decreased from a normal range of 1553-1584 m/s to a minimum of 1507 m/s. Multivariant linear regression was used in the analysis of covariance to fit the least-squares estimates to the linear regression model. Strong correlates of ultrasonic speed with both water concentration and fat concentration in the liver were observed.

Animals↗
PubMed1987

Legume carotenoids.

In recent years, the results of research studies have suggested a positive beneficial relationship between a vegetarian-based diet and low incidence of diseases, including coronary heart disease, cancer, obesity, dental caries, and osteoporosis. beta-Carotene has specifically been suggested as a nutrient with antitumorigenic properties. In this regard there is a need to evaluate the carotenoid content of foods. Legumes are one of the staple components of a vegetarian diet. This review specifically surveys the prevalence of carotenoids in food and forage legumes. In addition, the methods available for carotenoid analysis are discussed; factors affecting the determination of carotenoid content during maturation, germination, processing and storage are identified; research areas which have been inadequately explored are identified; and suggestions are made for future lines of investigation.

Carotenoids↗