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1.
The iron status of men, women and children consuming beef extended with soy protein was evaluated by measuring serum ferritin and clinical parameters of iron status during a six-month study. Fifty-two families (245 participants) were randomly assigned to consume, for 180 days, 1 of 7 beef products: all beef, beef extended with either soy isolate, soy concentrate or soy flour (20% reconstituted soy product, 80% beef), or beef extended with each of the three soy products fortified with 60 mg Fe and 25 mg Zn/100 g protein. The beef product was consumed by the subjects as their principal source of protein for 1 meal a day (children 1–18 yr) or 1–2 meals a day (11 per week; adult men and women). A control group consumed their usual self-selected diets. No evidence was found that consumption of beef extended with soy protein deleteriously affected the iron status of men, women or children. Consumption of beef extended with soy protein, at the levels used in this study, by military men and women and by school lunch participants would not appear to impose a risk in these population groups.  相似文献   

2.
We studied the potential of an animal model to predict nonheme iron absorption in humans and tested a feasible and easy technique of dosing59Fe to evaluate bioavailability of dietary nonheme iron. Plant diets containing about 20 ppm or 75 ppm iron were the nonheme iron sources with ferrous sulfate (75 ppm) as a reference. Radioiron was administered by (a) gavaging in water, 1 h after a meal; (b) mixing with the meal; and (c) making a slurry with the meal and gavaging. No significant differences were found (P0.05) in59Fe absorption among the three methods of administering radioiron. Absorption of59Fe was similar to apparent iron absorption for all diets tested, whether the animals consumed the same diet as that of the test meal or a different diet. A high correlation (r=0.88) obtained between the apparent iron absorption and59Fe iron absorption for different dosing techniques, indicates that extrinsic iron tag administered by any of these methods is valid to measure nonheme iron absorption. Apparent iron absorption values determined by rats fed 20 ppm or 75 ppm dietary iron from plant sources were similar to reported values for humans. It is concluded that the normal adult rat is an appropriate model to study iron bioavailability of human foods when iron status, maturity, iron intake relative to requirement, and method of measurement are similar to the human situation.  相似文献   

3.
The effect of long-term consumption, under practical conditions, of beef extended with soy protein on serum zinc levels of men, women and children was studied. Fifty-two families were randomly assigned to consume for 180 days 1 of 7 beef products: all beef, beef extended with either soy isolate, soy concentrate or soy flour (20% reconstituted soy product, 80% beef), or beef extended with each of the 3 soy products fortified with 60 mg Fe and 25 mg Zn/100g protein. The beef product was consumed by the subjects as their principal source of protein for 1 meal a day (children 1–8 yrs) or 1–2 meals a day (11 per week) for adult men and women. A control group consumed their usual self-selected diet. Diet records (4-day) of all foods and beverages consumed by the subjects were obtained pre-study and 63±7 and 126±7 days for calculation of nutrient intakes. No deleterious effects were found on the serum zinc levels when subjects consumed beef extended with soy protein for 180 days.Mention of a trademark or proprietary product does not constitute a guarantee or warranty of the product by the U.S. Department of Agriculture, and does not imply its approval to the exclusion of other products that may also be suitable.  相似文献   

4.
The effect of Spirulina on iron status was assessed based on hemoglobin, packed cell volume, serum iron, total iron binding capacity and ferritin levels of rats during pregnancy and lactation. Rats were fed 5 different kinds of diets (casein, Spirulina, wheat gluten, Spirulina + wheat gluten, Spirulina without additional vitamins and minerals) each providing 22 percent protein. Diets containing Spirulina alone or in combination with wheat gluten resulted in significantly higher iron storage and hemoglobin contents than casein and wheat gluten diets during the first half of pregnancy and lactation. Wheat gluten diet result in the smallest increase in hemoglobin levels and iron stores compared to other diets. The values of serum iron and iron binding capacity remained unchanged with different diets. Spirulina appears to be effective in improving the iron status of rats during pregnancy and lactation.  相似文献   

5.
Sana B  Johnson E  Sheah K  Poh CL  Lim S 《Biointerphases》2010,5(3):FA48-FA52
Self-assembling protein cages have been exploited as templates for nanoparticle synthesis. The ferritin molecule, a protein cage present in most living systems, stores excess soluble ferrous iron in the form of an insoluble ferric complex within its cavity. Magnetic nanocores formed by loading excess iron within an engineered ferritin from Archaeoglobus fulgidus (AfFtn-AA) were studied as a potential magnetic resonance (MR) imaging contrast agent. The self-assembly characteristics of the AfFtn-AA were investigated using dynamic light scattering technique and size exclusion chromatography. Homogeneous size distribution of the assembled nanoparticles was observed using transmission electron microscopy. The magnetic properties of iron-loaded AfFtn-AA were studied using vibrating sample magnetometry. Images obtained from a 3.0 T whole-body MRI scanner showed significant brightening of T(1) images and signal loss of T(2) images with increased concentrations of iron-loaded AfFtn-AA. The analysis of the MR image intensities showed extremely high R(2) values (5300?mM(-1)?s(-1)) for the iron-loaded AfFtn-AA confirming its potential as a T(2) contrast agent.  相似文献   

6.
The objective of this study was to evaluate the effect of proanthocyanidins (PAs) on iron uptake from soybean seed ferritin (SSF) crude by rats with iron deficiency anemia (IDA) for the first time. Six groups of Sprague–Dawley (SD) rats (n = 10) were used, which contain (1) SSF crude group; (2) SSF crude + PAs group; (3) PAs group; (4) FeSO4 group; (5) iron deficiency control group; and (6) control group. The bioavailability of iron was examined by measuring hemoglobin (Hb) concentration value, red blood cell (RBC) numbers, and serum iron stores. After 8 weeks, Hb concentration was almost recovered to the normal level upon feeding SSF crude or FeSO4 to rats. In contrast, Hb concentration was recovered to less extent when SSF crude plus PAs was used instead of SSF crude alone (P < 0.05). A similar profile was observed with these three sample groups when serum iron and RBC were used as parameters. All rats in PAs group died at the 8th week. Taken together, all these results demonstrated that PAs inhibited iron uptake of rats from SSF, and are toxic for rats with IDA.  相似文献   

7.
A simple method for improving the nutritive quality of canola and high glucosinolate rapeseed meals for monogastric animals (chicks) was developed; the meals were mixed with NaHCO3 and NH4HCO3, then heated in a conventional oven. Chicks fed untreated canola or rapeseed meals gained less weight than those fed a soybean meal diet, whereas chicks fed the alkaline-heated meals had weight gains not significantly different than those fed the soybean diet. The antithyroid effect of the untreated rapeseed meal was reduced by alkaline treatment of the meals, as shown by improved T4 and free T4 levels in chicks fed the processed products. In chicks fed untreated or alkaline-treated canola or alkaline heated rapeseed meal, all thyroid hormone levels were similar to those of birds fed the soybean meal diet. However, heart tissue of chicks fed diets containing rapeseed or canola meals showed muscle fiber degeneration, although relative heart weights were the same in all groups. Liver tissue from most of the chicks in all dietary groups appeared normal or only slightly abnormal. The nutritive value of both rapeseed and canola meals was improved by this simple processing technique.  相似文献   

8.
水稻根表铁膜对磷的富集作用及其与水稻磷吸收的关系   总被引：13，自引：0，他引：13  
采用溶液培养方法,使铁毒耐性不同的两个基因型水稻根表分别形成有铁膜和无铁膜的根系,研究水稻根表铁膜对磷的富集作用及其与水稻磷吸收的关系。不同基因型水稻根表形成的铁膜厚度存在显著差异,对介质中磷的富集能力也有显著差异。根表形成的铁膜越厚,对介质中磷的富集作用也越大,即根表铁膜数量与铁膜对磷的富集量呈显著正相关。铁膜对磷的富集作用是一个化学过程,吸附可在0.5~1.0 h内达到饱和。根表铁膜明显促进水稻对磷的吸收,表明在淹水降低土壤磷有效性时,水稻根表铁膜富集的磷可作为磷库,保证水稻能正常吸收利用磷。  相似文献   

9.
The bioavailability of riboflavin from fortified palm juice was assessed in young adult men, Riboflavin status was assessed from urinary riboflavin excretion and erythrocyte glutathione reductase activity coefficient (EGR-AC) while iron status was assessed from haemoglobin and serum ferritin concentrations. Although the consumption of unfortified palm juice made significant contribution to the meager riboflavin intake, it conferred no metabolic advantage. The consumption of fortified palm juice produced a marked reduction in EGR-AC values and a significant increase in urinary riboflavin excretion. Since iron release from storage sites may be flavin dependent, riboflavin deficiency may affect iron utilization. Fortification may prove effective in alleviating nutrient deficiencies, but the carrier vehicle must be acceptable to all age groups.  相似文献   

10.
Studies were carried out on thein vitro availability of iron from a standard cereal meal with and without the addition of bovine milk (BM), groundnut milk (GM) and soybean milk (SM). Further, availability of iron from these milks per se was also investigated. Estimation of the total iron content from BM, GM, and SM revealed that it was highest in case of SM followed by GM and BM. This trend was reversed for percent available iron which was highest for BM followed by GM and SM. Thein vitro availability of iron from the cereal meal was low (3.7%). Addition of BM and GM enhanced the availability of iron from the standard meal whereas SM had no particular enhancing quality. The practical implications of the findings for iron nutrition in humans are discussed.  相似文献   

11.
A totaI of 105 transgenic rice lines independently transformed with a pea ferritin gene (Fer)were previously obtained.After seven generations of selfing and β-glucuronidase(GUS)assisted selection,82 transgenic lines with stable agronomic traits were got.Among the 82 transgenic lines,two high-iron transgenic rice lines Fer34 and Fer65,with the iron contents in the milled rice being 4.82 and 3.46 times of that of the wild type Xiushui 11,respectively were identified.In the two transgenic lines,the exogenous Fer gene was highly expressed,and inherited as a single locus.The transgene had no negative effect on the agronomic traits of rice plant,other mineral nutritional components,appearance quailty and eating quailty of the milled rice,indicating that these two lines were elite high-iron breeding lines.Furthermore,the practical application and further studies facilitating utilization of the two elite breeding lines were discussed.  相似文献   

12.
The estimation of glycemic index(GI) of rice-based mixed meal either by using predicted GI(GI_(pred)) or adjusted GI(GI_(adj)) formula is unclear.This study aimed to determine the glycemic response of rice in rice alone or mixed meals and to identify the appropriate formula for estimating the GI of rice-based mixed meals.The glycemic responses produced by the rice alone(red rice,fragrant white rice or parboiled rice) and the rice-based mixed meals(fried red rice,fried fragrant white rice or fried parboiled rice) which provided 25 g available carbohydrate were assessed in 11 healthy individuals.To determine the measured GI(GImeasured) of rice alone and rice-based mixed meals,participants underwent three repeated tests of a reference food(Glucolin~?).Tests were performed in random order on nine separate visits after an overnight fasting for at least 8 h.Capillary glucose at baseline(0 min),15,30,45,60,90 and 120 min from starting the meals was assessed and used to determine the incremental area under the curve(iAUC_(120)).The agreement between GImeasured and the estimation formulae(GI_(pred) or GI_(adj)) were determined using Bland-Altman analysis.The iAUC_(120) after consuming rice alone was significantly higher than the rice-based mixed meals except for fried fragrant rice,which was comparable to the rice alone(P 0.05).The GI_(measured) values of rice were categorized as medium(61 for parboiled rice,67 for fragrant white rice,and 68 for red rice).GI_(pred)(r = 0.40,P 0.01) and GI_(adj)(r = 0.41,P 0.01) were significantly correlated with iAUC_(120).The agreement between GI_(measured) and GI_(adj) is apparent suggesting the usefulness of GI_(adj) in estimating meal GI of rice-based mixed meals.  相似文献   

13.
磷（P）对水稻生长的影响仅次于氮。P在土壤中含量丰富,但由于其难溶性及土壤的高吸附性,可被植物直接吸收利用的活性P含量很低。根表铁膜对土壤中的P有很强的吸附作用,在一定程度上是植物的营养库,铁膜中的P是植物吸收的重要P源。有关根表铁膜与水稻P吸收的关系已有很多报道,是促进还是抑制作用情况比较复杂。本文综述了水稻根表铁膜的形成原因、对P的吸附与解吸附能力以及对水稻吸收利用的影响,并对今后开展根表铁膜对水稻P吸收的调控机理研究提出几点建议,同时对根表铁膜调控水稻P吸收的应用前景进行了展望。  相似文献   

14.
The present study was carried out to investigate the availability of iron from spirulina, whole wheat, whole egg and standard ferrous sulphate in terms of haemoglobin formation, serum and tissue iron levels. Male albino Wistar rats were first depleted of iron by giving low-iron diet (9 ppm) and bleeding 1–2 ml blood at weekly intervals for a period of 21 days. The anaemic rats were repleted with iron sources at a level of 35 ppm for 21 days. Rats receiving whole egg gained significantly (p<0.01) higher weight than the rest of the three groups. The increase in haemoglobin was significantly higher with ferrous sulphate than with whole wheat (p<0.05), spirulina and whole egg (p<0.01). Feeding of ferrous sulphate, whole egg and spirulina produced significantly higher tissue iron levels than feeding of whole wheat. Thus, availability of iron from spirulina and whole egg were found to be comparable to that of the standard.  相似文献   

15.
The purpose of this study was to investigate iron status of premenopausalvegetarian women consuming tofu or tofu plus orange juice. Following athree day pre-period, 14 lacto-ovo vegetarians were randomly divided intotwo experimental periods of 30 days each. For the first 30 days, one halfof the subjects (n = 7) received 6 oz (173 grams) of tofu/day (T) while theother half of the subjects (n = 7) received 6 oz of tofu/day along with303 mg of vitamin C/d (TO). After 30 days, there was a crossover ofthe diets. Iron status was assessed by measuring serum ferritin andhemoglobin concentrations on the first day of the study and at the end ofeach experimental period. The Mann Whitney-U test was significant duringthe first (W = 17.5; Z = –2.095; p = 0.0361) and over the second (W = 40.0; Z = –2.611; p = 0.009) experimental periods which indicated thechange in hemoglobin levels for the T and TO groups were different. Meanranks showed a greater increase in hemoglobin levels for the TO group.There was no significant difference in the change in serum ferritin levelsbetween the T and TO groups over the first and second experimentalperiods. In conclusion, bioavailability of iron from tofu is enhancedby supplementation with ascorbic acid.  相似文献   

16.
We investigated whether a test drink enriched in pomegranate polyphenols, consumed with a high-fat meal, can reduce postprandial lipaemia and improve vascular function and blood pressure compared to placebo. Nineteen young, healthy men completed a randomized, controlled crossover trial. The active drink (containing a pomegranate extract) was consumed during a high-fat meal (ET-DUR) or 15 min before (ET-PRE), and the placebo drink (no pomegranate extract) was consumed during the high-fat meal (CONTROL). Postprandial lipaemia was assessed by venous plasma TAG 0–2 h, and capillary plasma TAG 0–4 h. Blood pressure and digital volume pulse, to measure reflection index (DVP-RI) and stiffness index (DVP-SI), were monitored at baseline, 2 and 4 h. There was no inhibition of postprandial lipaemia by the active drink compared to CONTROL. ET-PRE caused a greater increase in the venous plasma TAG at 2 h compared to CONTROL and ET-DUR (treatment effect P?=?0.001). The incremental area under the curve 0–4 h for capillary plasma TAG was not significantly different between treatments. Systolic blood pressure (SBP) increased in the ET-PRE and ET-DUR groups to a lesser extent than the CONTROL group (treatment effect P?=?0.041). There were no treatment effects for DVP-RI, DVP-SI or diastolic blood pressure. In conclusion, the consumption of a single drink containing ET-rich pomegranate extract did not decrease postprandial plasma TAG concentrations, but suppressed the postprandial increase in SBP following the high-fat meal.  相似文献   

17.
In vitro iron availability was determined from a standard cereal meal (C) with and without the addition of protein isolates from bovine milk (BP), groundnut milk (GP) and soybean milk (SP). A second set of studies were done to investigate the potentially available iron from fenugreek leaves per se and the effect of their addition on the available iron from the cereal meal. The potentially available iron from the meal increased from 4.91% to 6.73% on the addition of BP. The next best enhancer was GP (4.91% to 6.17%). Although the addition of SP increased the total iron content of the cereal meal significantly, the percent available iron decreased compared to the other milk proteins. The addition of fenugreek leaves (100 g/meal) to the meal increased the total iron content of the meal significantly (3.24 mg to 9.12 mg) (p<.001), however, the available iron was observed to decrease (4.91% vs 4.34%).  相似文献   

18.
Prostate cancer is a common cause of cancer death in men. In advanced stages of prostate cancer, androgen deprivation therapy (ADT) is initiated. Despite ADT, prostate cancers invariably progress to become androgen independent. A growing body of evidence implicates iron dysmetabolism in prostate cancer progression. A bioactive peptide-rich salmon protein hydrolysate (SPH) has previously been demonstrated to modulate iron homeostatic mechanisms. In the present study, the anticancer effect of SPH and bicalutamide co-treatment on LNCaP and PC3 prostate cancer cell proliferation was investigated. Our results found that SPH potentiates the anti-proliferative effect of bicalutamide in a dose-dependent manner for both cell lines. In the presence of 160 µg/mL SPH, co-treatment with 1.0 µM bicalutamide decreased LNCaP cells’ relative colony survival from 25% (1.0 µM bicalutamide monotreatment) to 2% after culturing for 12 days. For PC3 cells, the relative colony survival diminished from 52% (10.0 µM bicalutamide) to 32% at an SPH concentration of 160 µg/mL. Gene expression profiling, employing quantitative real-time PCR, revealed that the inhibitory effects were related to significant FTH1 up-regulation with a concomitant TFRC down-regulation. In conclusion, our results provide in vitro evidence that SPH potentiates the growth inhibitory effect of bicalutamide on prostate cancer cells by modulating iron homeostasis mechanisms.  相似文献   

19.
Thiocyanate levels were determined in serum and urine samples obtained from a human population sample of healthy non-smoking volunteers (aged between 14 and 30 years) of both sexes known to eat gari-based meals at least once a day. The samples were collected before and 3–4 hours after a gari- or rice-based meal. The values obtained before the test meals showed a wide variation, ranging between 39.20±1.95 to 160.95±8.06 µmol/l of serum, and 81.92±9.78 to 294.01±14.70 µmol/l of urine. For each volunteer, the serum and urine thiocyanate were affected by the test meals. Average increases of 18 and 20% were observed for serum and urine thiocyanate, respectively, following a gari-based meal. A rice-based meal produced, on the average, 10% decrease in both serum and urine thiocyanate. No significant effect of sex or age on the thiocyanate levels was observed. The gari samples used in the study, as well as random samples from the locality of study, had no detectable thiocyanate but contained between 0.013 and 0.015 mg cyanide per kg of gari. These findings indicate that conversion to thiocyanate is a significant pathway in the metabolism of HCN and contributes significantly to thiocyanate found in body fluids and tissues of man. In addition, support is provided for the possible involvement of the sulphurtransferases in the process of cyanide detoxication.  相似文献   

20.
The bioavailability of iron from habitually consumed diet by pre-adolescent children of low socio-economic group and the diet supplemented with additional 8 g of protein supplied by 34 g legumes (Green gram and Moth bean 1:1) or 195 ml of buffalo's milk to per day diet was studied in anaemic rats using haemoglobin regeneration method. The bioavailability of iron for haemoglobin regeneration relative to FeSO4 was 69.5 percent from milk supplemented diet as compared to 47.5 percent from the diet normally consumed by pre-adolescent children of low socio-economic group while legume supplementation to the diet showed no improvement.  相似文献   

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